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Cleaning circuit boards of solder flux residue
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Joe Gwinn
Jul 25, 2015, 11:14:20 AM7/25/15
to
This is a follow-on to the "Reverse polarity, Scotty" thread of
September 2013, where the issue was how to clean a circuit board of
soldering flux residue well enough for a 50 Gigaohm node to work.
I recently read a book on soldering ("Solders and Soldering", Howard H
Manko, 3rd edition, McGraw-Hill 1992), which has extensive treatment of
removal of flux residue.
In the Reverse-Polarity thread, use of Kester 44 cored solder was
discussed, so the flux in question is based on rosin.
For rosin residue, the book's recommendation (page 315) is first
cleaning with a terpene solvent (to dissolve rosin and other organic
residue) followed by a hot-water wash. This is called the
"Semi-Aqueous Cleaning Process".
On small scale, dunking in terpentine from the paint store, shaking
off, and passage through a domestic dishwasher using for instance
AlcoJet detergent, followed by a wax-dip conformal coat, would do the
job.
Joe Gwinn
September 2013, where the issue was how to clean a circuit board of
soldering flux residue well enough for a 50 Gigaohm node to work.
I recently read a book on soldering ("Solders and Soldering", Howard H
Manko, 3rd edition, McGraw-Hill 1992), which has extensive treatment of
removal of flux residue.
In the Reverse-Polarity thread, use of Kester 44 cored solder was
discussed, so the flux in question is based on rosin.
For rosin residue, the book's recommendation (page 315) is first
cleaning with a terpene solvent (to dissolve rosin and other organic
residue) followed by a hot-water wash. This is called the
"Semi-Aqueous Cleaning Process".
On small scale, dunking in terpentine from the paint store, shaking
off, and passage through a domestic dishwasher using for instance
AlcoJet detergent, followed by a wax-dip conformal coat, would do the
job.
Joe Gwinn
DecadentLinuxUserNumeroUno
Jul 25, 2015, 11:40:48 AM7/25/15
to
On Sat, 25 Jul 2015 11:14:16 -0400, Joe Gwinn <joeg...@comcast.net>
Gave us:
>This is a follow-on to the "Reverse polarity, Scotty" thread of
>September 2013, where the issue was how to clean a circuit board of
>soldering flux residue well enough for a 50 Gigaohm node to work.
Use a brominated solvent..
"Ensolv" works very well, and they'll send you a quart sample, but the
actual product in qty ain't cheap. So be prepared to fork out some cash
to get a really clean assembly.
http://www.envirotechint.com/industrial-solvents/npb-solvents/
Gave us:
>This is a follow-on to the "Reverse polarity, Scotty" thread of
>September 2013, where the issue was how to clean a circuit board of
>soldering flux residue well enough for a 50 Gigaohm node to work.
"Ensolv" works very well, and they'll send you a quart sample, but the
actual product in qty ain't cheap. So be prepared to fork out some cash
to get a really clean assembly.
http://www.envirotechint.com/industrial-solvents/npb-solvents/
DecadentLinuxUserNumeroUno
Jul 25, 2015, 11:44:42 AM7/25/15
to
On Sat, 25 Jul 2015 11:40:06 -0400, DecadentLinuxUserNumeroUno
<DL...@DecadentLinuxUser.org> Gave us:
Also, you need to vacuum the assembly for a half hour, and preferably
at around 60° C to evacuate any water in the PCB as they are
hygroscopic.
Also, the area where you want the leakage minimized should be a
section of PCB which is FREE of any mask layer. i.e. BARE BOARD.
Note too that without encapsulation, the assembly will slowly take on
water again.
<DL...@DecadentLinuxUser.org> Gave us:
at around 60° C to evacuate any water in the PCB as they are
hygroscopic.
Also, the area where you want the leakage minimized should be a
section of PCB which is FREE of any mask layer. i.e. BARE BOARD.
Note too that without encapsulation, the assembly will slowly take on
water again.
John Larkin
Jul 25, 2015, 12:33:36 PM7/25/15
to
On Sat, 25 Jul 2015 11:14:16 -0400, Joe Gwinn <joeg...@comcast.net>
wrote:
>This is a follow-on to the "Reverse polarity, Scotty" thread of
>September 2013, where the issue was how to clean a circuit board of
>soldering flux residue well enough for a 50 Gigaohm node to work.
>
>I recently read a book on soldering ("Solders and Soldering", Howard H
>Manko, 3rd edition, McGraw-Hill 1992), which has extensive treatment of
>removal of flux residue.
>
>In the Reverse-Polarity thread, use of Kester 44 cored solder was
>discussed, so the flux in question is based on rosin.
>
>For rosin residue, the book's recommendation (page 315) is first
>cleaning with a terpene solvent (to dissolve rosin and other organic
>residue) followed by a hot-water wash. This is called the
>"Semi-Aqueous Cleaning Process".
turning nice insulating rosin flux into hygroscopic conductive crud.
Water is the enemy of insulation.
"Terpene" is apparently a broad category of chemicals.
https://en.wikipedia.org/wiki/Terpene
>
>On small scale, dunking in terpentine from the paint store, shaking
>off, and passage through a domestic dishwasher using for instance
>AlcoJet detergent, followed by a wax-dip conformal coat, would do the
>job.
You don't need to clean rosin flux except for cosmetics. If you do
clean them, use an organic solvent. I like acetone for small DIY
boards, as long as it doesn't damage parts and as long as you don't
inhale or absorb much of it. We have fancy expensive solvents that we
use in our non-water board cleaner. We do water wash processing, too,
but that creates leakage if not managed very carefully.
Polyurethane varnish is a good conformal coat. Bake first.
--
John Larkin Highland Technology, Inc
lunatic fringe electronics
jlarkin att highlandtechnology dott com
http://www.highlandtechnology.com
Kevin McMurtrie
Jul 25, 2015, 6:30:06 PM7/25/15
to
In article <250720151114160271%joeg...@comcast.net>,
CFCs were excellent. I've heard that toluene condensation cleaners were
the absolute best, except for the part where you die young of cancer.
I've had bad experiences with turpentine gumming in the PCB. Automotive
brake cleaner (benzene, acetone, isopropanol) works very well but with
some risk to the health of components and yourself. Overall, real rosin
flux remover is the way to go. Follow up with de-ionized water, gently
bake in a vacuum, and then it's CLEAN.
I don't need 50G Ohm circuits but I need them clean and dry before I
soak them in conformal coating to help weatherproof them. A little damp
flux under the coating will eventually electroplate itself a short
circuit.
--
I will not see posts from astraweb, theremailer, dizum, or google
because they host Usenet flooders.
the absolute best, except for the part where you die young of cancer.
I've had bad experiences with turpentine gumming in the PCB. Automotive
brake cleaner (benzene, acetone, isopropanol) works very well but with
some risk to the health of components and yourself. Overall, real rosin
flux remover is the way to go. Follow up with de-ionized water, gently
bake in a vacuum, and then it's CLEAN.
I don't need 50G Ohm circuits but I need them clean and dry before I
soak them in conformal coating to help weatherproof them. A little damp
flux under the coating will eventually electroplate itself a short
circuit.
--
I will not see posts from astraweb, theremailer, dizum, or google
because they host Usenet flooders.
Jeff Liebermann
Jul 25, 2015, 6:47:05 PM7/25/15
to
flux. Left in place, it will eventually corrode the joint, although
it may take longer than the useful life of the product.
In my chequered past, I used to design marine radios which needed to
survive in rather nasty environmental conditions. Although we made it
a rule to design only using low impedance circuits to minimize the
effects of board leakage. Unfortunately, I inherited a high impedance
design, and as predicted, board leakage became an issue.
Using both a hot water and organic solvent rinse is common, but not
for the stated reason. The organic solvent removes the bulk of the
residue, but the water rinse removes the usual white salt produced
during the PCB manufacturing processes and soldering process. Here's
a bit of a clue on how some of the white residue works:
<http://www.kester.com/kester-content/uploads/2013/06/White_Residue.pdf>
Notice that some of the residues are NOT water soluble.
For marine radios, the order an sequence was literally boil the raw
PCB's water. If the silk screen or solder mask flakes off, then the
PCB manufacturer left a layer of grease on the board before silk
screening. They can be stripped and easily rescreen and solder
masked. The boards are then baked dry.
The boards are then soldered. During the 1970's, it was all tin-lead
solder, ecologically disgusting fluxes, and ozone depleting cleaners.
Those "good olde daze" are gone forever.
After soldering, the boards were washed in various organic solvent
cleaners to remove the flux. They were then air dried, and stuffed
into a commercial dish washer repurposed as a PCB washer. Other than
pumping the lime out of the bottom of the water heater, it worked
nicely. They were then baked dry in an IR oven. There were parallel
traces on the PCB suitable for running a resistivity test.
As soon as possible, the PCB's were then coated with whatever
conformal coating was favored this week. We used wax, urethane,
acrylic, and epoxy which was applied as a dip, spray, or brush. Except
for when someone forgot to mask off connectors and critical parts, the
conformal coating worked well.
That basic idea behind this ordeal process was to tread the organic
and ionic contaminants separately, evaporate off any solvent residue,
and seal the board before condensation had a chance to land on the
PCB.
Turpentine is a bad idea. It's what is removed from the tree sap to
make gum rosin. The turpentine is hygroscopic (absorbs moisture) and
will make a great humidity meter out of your circuit. At best, it
will soften the rosin allowing you to smear it all over the PCB,
producing a sticky mess.
Drivel: Speaking of PCB leakage, I've been playing with a first
generation night vision contraption.
<http://802.11junk.com/jeffl/pics/AN-SAR-4B%20night%20vision/index.html>
The 19KV power supply is mostly a clear plastic block with a few very
large value resistors inside. Every time I play with this section,
and touch the plastic, I produce a leakage path through the skin oil
residue, which requires a 99% reagent grade alcohol rinse to
decontaminate. Lately, I've been using Latex rubber gloves, which
seems to have cured my bad habit of touching the plastic lbock.
--
Jeff Liebermann je...@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Joe Gwinn
Jul 25, 2015, 7:55:50 PM7/25/15
to
In article <1od7rapa8jh41n17i...@4ax.com>, John Larkin
or components.
> >On small scale, dunking in terpentine from the paint store, shaking
> >off, and passage through a domestic dishwasher using for instance
> >AlcoJet detergent, followed by a wax-dip conformal coat, would do the
> >job.
>
> That's a recipe for humidity-erratic leakage.
Only if you forget the second part - wash with hot water and AlcoJet
(which sponifies the terpine goo).
The hot water is also essential to get the ionic contamination off the
board.
> You don't need to clean rosin flux except for cosmetics. If you do
> clean them, use an organic solvent. I like acetone for small DIY
> boards, as long as it doesn't damage parts and as long as you don't
> inhale or absorb much of it. We have fancy expensive solvents that we
> use in our non-water board cleaner. We do water wash processing, too,
> but that creates leakage if not managed very carefully.
In my world, we always clean the boards and then conformal coat. Rosin
undermines the conformal coat.
> Polyurethane varnish is a good conformal coat. Bake first.
Ordinarily, yes, but not at 50 Gohms.
Joe Gwinn
<jla...@highlandtechnology.com> wrote:
> On Sat, 25 Jul 2015 11:14:16 -0400, Joe Gwinn <joeg...@comcast.net>
> wrote:
>
> >This is a follow-on to the "Reverse polarity, Scotty" thread of
> >September 2013, where the issue was how to clean a circuit board of
> >soldering flux residue well enough for a 50 Gigaohm node to work.
> >
> >I recently read a book on soldering ("Solders and Soldering", Howard H
> >Manko, 3rd edition, McGraw-Hill 1992), which has extensive treatment of
> >removal of flux residue.
> >
> >In the Reverse-Polarity thread, use of Kester 44 cored solder was
> >discussed, so the flux in question is based on rosin.
> >
> >For rosin residue, the book's recommendation (page 315) is first
> >cleaning with a terpene solvent (to dissolve rosin and other organic
> >residue) followed by a hot-water wash. This is called the
> >"Semi-Aqueous Cleaning Process".
>
> Bad idea. If the terpene makes the flux water soluble, you'll be
> turning nice insulating rosin flux into hygroscopic conductive crud.
> Water is the enemy of insulation.
>
> "Terpene" is apparently a broad category of chemicals.
>
> https://en.wikipedia.org/wiki/Terpene
Yes. The point is that it dissolves rosin without dissolving the board
> On Sat, 25 Jul 2015 11:14:16 -0400, Joe Gwinn <joeg...@comcast.net>
> wrote:
>
> >This is a follow-on to the "Reverse polarity, Scotty" thread of
> >September 2013, where the issue was how to clean a circuit board of
> >soldering flux residue well enough for a 50 Gigaohm node to work.
> >
> >I recently read a book on soldering ("Solders and Soldering", Howard H
> >Manko, 3rd edition, McGraw-Hill 1992), which has extensive treatment of
> >removal of flux residue.
> >
> >In the Reverse-Polarity thread, use of Kester 44 cored solder was
> >discussed, so the flux in question is based on rosin.
> >
> >For rosin residue, the book's recommendation (page 315) is first
> >cleaning with a terpene solvent (to dissolve rosin and other organic
> >residue) followed by a hot-water wash. This is called the
> >"Semi-Aqueous Cleaning Process".
>
> Bad idea. If the terpene makes the flux water soluble, you'll be
> turning nice insulating rosin flux into hygroscopic conductive crud.
> Water is the enemy of insulation.
>
> "Terpene" is apparently a broad category of chemicals.
>
> https://en.wikipedia.org/wiki/Terpene
or components.
> >On small scale, dunking in terpentine from the paint store, shaking
> >off, and passage through a domestic dishwasher using for instance
> >AlcoJet detergent, followed by a wax-dip conformal coat, would do the
> >job.
>
> That's a recipe for humidity-erratic leakage.
(which sponifies the terpine goo).
The hot water is also essential to get the ionic contamination off the
board.
> You don't need to clean rosin flux except for cosmetics. If you do
> clean them, use an organic solvent. I like acetone for small DIY
> boards, as long as it doesn't damage parts and as long as you don't
> inhale or absorb much of it. We have fancy expensive solvents that we
> use in our non-water board cleaner. We do water wash processing, too,
> but that creates leakage if not managed very carefully.
undermines the conformal coat.
> Polyurethane varnish is a good conformal coat. Bake first.
Joe Gwinn
Joe Gwinn
Jul 25, 2015, 7:56:55 PM7/25/15
to
In article <mcmurtrie-0BD39...@news.sonic.net>, Kevin
You also need the second step, to wash in hot water with AlcoJet
detergent.
> I don't need 50G Ohm circuits but I need them clean and dry before I
> soak them in conformal coating to help weatherproof them. A little damp
> flux under the coating will eventually electroplate itself a short
> circuit.
Yep.
Joe Gwinn
detergent.
> I don't need 50G Ohm circuits but I need them clean and dry before I
> soak them in conformal coating to help weatherproof them. A little damp
> flux under the coating will eventually electroplate itself a short
> circuit.
Joe Gwinn
Joe Gwinn
Jul 25, 2015, 8:01:42 PM7/25/15
to
In article <ii28rat484lve46m8...@4ax.com>, Jeff
up.
> In my chequered past, I used to design marine radios which needed to
> survive in rather nasty environmental conditions. Although we made it
> a rule to design only using low impedance circuits to minimize the
> effects of board leakage. Unfortunately, I inherited a high impedance
> design, and as predicted, board leakage became an issue.
>
> Using both a hot water and organic solvent rinse is common, but not
> for the stated reason. The organic solvent removes the bulk of the
> residue, but the water rinse removes the usual white salt produced
> during the PCB manufacturing processes and soldering process. Here's
> a bit of a clue on how some of the white residue works:
> <http://www.kester.com/kester-content/uploads/2013/06/White_Residue.pdf>
> Notice that some of the residues are NOT water soluble.
Yes, this is another semi-aqueous cleaning method.
> For marine radios, the order an sequence was literally boil the raw
> PCB's water. If the silk screen or solder mask flakes off, then the
> PCB manufacturer left a layer of grease on the board before silk
> screening. They can be stripped and easily rescreen and solder
> masked. The boards are then baked dry.
>
> The boards are then soldered. During the 1970's, it was all tin-lead
> solder, ecologically disgusting fluxes, and ozone depleting cleaners.
> Those "good olde daze" are gone forever.
>
> After soldering, the boards were washed in various organic solvent
> cleaners to remove the flux. They were then air dried, and stuffed
> into a commercial dish washer repurposed as a PCB washer. Other than
> pumping the lime out of the bottom of the water heater, it worked
> nicely. They were then baked dry in an IR oven. There were parallel
> traces on the PCB suitable for running a resistivity test.
>
> As soon as possible, the PCB's were then coated with whatever
> conformal coating was favored this week. We used wax, urethane,
> acrylic, and epoxy which was applied as a dip, spray, or brush. Except
> for when someone forgot to mask off connectors and critical parts, the
> conformal coating worked well.
>
> That basic idea behind this ordeal process was to tread the organic
> and ionic contaminants separately, evaporate off any solvent residue,
> and seal the board before condensation had a chance to land on the
> PCB.
This is precisely the process detailed in the book.
> Turpentine is a bad idea. It's what is removed from the tree sap to
> make gum rosin. The turpentine is hygroscopic (absorbs moisture) and
> will make a great humidity meter out of your circuit. At best, it
> will soften the rosin allowing you to smear it all over the PCB,
> producing a sticky mess.
The book did call terpenes out as the solvent to use. The hot water
and detergent wash removed the residue.
> Drivel: Speaking of PCB leakage, I've been playing with a first
> generation night vision contraption.
> <http://802.11junk.com/jeffl/pics/AN-SAR-4B%20night%20vision/index.html>
> The 19KV power supply is mostly a clear plastic block with a few very
> large value resistors inside. Every time I play with this section,
> and touch the plastic, I produce a leakage path through the skin oil
> residue, which requires a 99% reagent grade alcohol rinse to
> decontaminate. Lately, I've been using Latex rubber gloves, which
> seems to have cured my bad habit of touching the plastic bock.
Maybe a smaller leak resistor would break you of the habit - ZAP!
Joe Gwinn
Liebermann <je...@cruzio.com> wrote:
> On Sat, 25 Jul 2015 11:14:16 -0400, Joe Gwinn <joeg...@comcast.net>
> wrote:
>
> >This is a follow-on to the "Reverse polarity, Scotty" thread of
> >September 2013, where the issue was how to clean a circuit board of
> >soldering flux residue well enough for a 50 Gigaohm node to work.
> >
> >I recently read a book on soldering ("Solders and Soldering", Howard H
> >Manko, 3rd edition, McGraw-Hill 1992), which has extensive treatment of
> >removal of flux residue.
> >
> >In the Reverse-Polarity thread, use of Kester 44 cored solder was
> >discussed, so the flux in question is based on rosin.
> >
> >For rosin residue, the book's recommendation (page 315) is first
> >cleaning with a terpene solvent (to dissolve rosin and other organic
> >residue) followed by a hot-water wash. This is called the
> >"Semi-Aqueous Cleaning Process".
> >
> >On small scale, dunking in terpentine from the paint store, shaking
> >off, and passage through a domestic dishwasher using for instance
> >AlcoJet detergent, followed by a wax-dip conformal coat, would do the
> >job.
> >
> >Joe Gwinn
>
> I beg to differ somewhat. Kester 44 rosin flux is an organic acid
> flux. Left in place, it will eventually corrode the joint, although
> it may take longer than the useful life of the product.
Yes, ordinarily, but the issue was surface leakage messing the circuit
> On Sat, 25 Jul 2015 11:14:16 -0400, Joe Gwinn <joeg...@comcast.net>
> wrote:
>
> >This is a follow-on to the "Reverse polarity, Scotty" thread of
> >September 2013, where the issue was how to clean a circuit board of
> >soldering flux residue well enough for a 50 Gigaohm node to work.
> >
> >I recently read a book on soldering ("Solders and Soldering", Howard H
> >Manko, 3rd edition, McGraw-Hill 1992), which has extensive treatment of
> >removal of flux residue.
> >
> >In the Reverse-Polarity thread, use of Kester 44 cored solder was
> >discussed, so the flux in question is based on rosin.
> >
> >For rosin residue, the book's recommendation (page 315) is first
> >cleaning with a terpene solvent (to dissolve rosin and other organic
> >residue) followed by a hot-water wash. This is called the
> >"Semi-Aqueous Cleaning Process".
> >
> >On small scale, dunking in terpentine from the paint store, shaking
> >off, and passage through a domestic dishwasher using for instance
> >AlcoJet detergent, followed by a wax-dip conformal coat, would do the
> >job.
> >
> >Joe Gwinn
>
> I beg to differ somewhat. Kester 44 rosin flux is an organic acid
> flux. Left in place, it will eventually corrode the joint, although
> it may take longer than the useful life of the product.
up.
> In my chequered past, I used to design marine radios which needed to
> survive in rather nasty environmental conditions. Although we made it
> a rule to design only using low impedance circuits to minimize the
> effects of board leakage. Unfortunately, I inherited a high impedance
> design, and as predicted, board leakage became an issue.
>
> Using both a hot water and organic solvent rinse is common, but not
> for the stated reason. The organic solvent removes the bulk of the
> residue, but the water rinse removes the usual white salt produced
> during the PCB manufacturing processes and soldering process. Here's
> a bit of a clue on how some of the white residue works:
> <http://www.kester.com/kester-content/uploads/2013/06/White_Residue.pdf>
> Notice that some of the residues are NOT water soluble.
> For marine radios, the order an sequence was literally boil the raw
> PCB's water. If the silk screen or solder mask flakes off, then the
> PCB manufacturer left a layer of grease on the board before silk
> screening. They can be stripped and easily rescreen and solder
> masked. The boards are then baked dry.
>
> The boards are then soldered. During the 1970's, it was all tin-lead
> solder, ecologically disgusting fluxes, and ozone depleting cleaners.
> Those "good olde daze" are gone forever.
>
> After soldering, the boards were washed in various organic solvent
> cleaners to remove the flux. They were then air dried, and stuffed
> into a commercial dish washer repurposed as a PCB washer. Other than
> pumping the lime out of the bottom of the water heater, it worked
> nicely. They were then baked dry in an IR oven. There were parallel
> traces on the PCB suitable for running a resistivity test.
>
> As soon as possible, the PCB's were then coated with whatever
> conformal coating was favored this week. We used wax, urethane,
> acrylic, and epoxy which was applied as a dip, spray, or brush. Except
> for when someone forgot to mask off connectors and critical parts, the
> conformal coating worked well.
>
> That basic idea behind this ordeal process was to tread the organic
> and ionic contaminants separately, evaporate off any solvent residue,
> and seal the board before condensation had a chance to land on the
> PCB.
> Turpentine is a bad idea. It's what is removed from the tree sap to
> make gum rosin. The turpentine is hygroscopic (absorbs moisture) and
> will make a great humidity meter out of your circuit. At best, it
> will soften the rosin allowing you to smear it all over the PCB,
> producing a sticky mess.
and detergent wash removed the residue.
> Drivel: Speaking of PCB leakage, I've been playing with a first
> generation night vision contraption.
> <http://802.11junk.com/jeffl/pics/AN-SAR-4B%20night%20vision/index.html>
> The 19KV power supply is mostly a clear plastic block with a few very
> large value resistors inside. Every time I play with this section,
> and touch the plastic, I produce a leakage path through the skin oil
> residue, which requires a 99% reagent grade alcohol rinse to
> decontaminate. Lately, I've been using Latex rubber gloves, which
Maybe a smaller leak resistor would break you of the habit - ZAP!
Joe Gwinn
John Larkin
Jul 25, 2015, 8:20:08 PM7/25/15
to
On Sat, 25 Jul 2015 19:55:41 -0400, Joe Gwinn <joeg...@comcast.net>
This little board was deliberately maxi-glopped with RMA flux:
https://dl.dropboxusercontent.com/u/53724080/Gear/Keithley/Leak_Gloppy_Flux.JPG
https://dl.dropboxusercontent.com/u/53724080/Gear/Keithley/Leak_Test.JPG
and pins the meter on the 1e14 ohm range.
We have recently had some problems on some analog acquisition boards,
water soluble flux and water (saponifier and then multiple rinses in
hi-Z water) wash. Conductive stuff likes to hide under CSP/QFN
packages.
https://dl.dropboxusercontent.com/u/53724080/Gear/Keithley/Leak_Gloppy_Flux.JPG
https://dl.dropboxusercontent.com/u/53724080/Gear/Keithley/Leak_Test.JPG
and pins the meter on the 1e14 ohm range.
We have recently had some problems on some analog acquisition boards,
water soluble flux and water (saponifier and then multiple rinses in
hi-Z water) wash. Conductive stuff likes to hide under CSP/QFN
packages.
Phil Hobbs
Jul 25, 2015, 8:53:02 PM7/25/15
to
>We have recently had some problems on some analog acquisition boards,
>water soluble flux and water (saponifier and then multiple rinses in
>hi-Z water) wash. Conductive stuff likes to hide under CSP/QFN
>packages.
Cheers
Phil Hobbs
Jeff Liebermann
Jul 25, 2015, 8:56:25 PM7/25/15
to
On Sat, 25 Jul 2015 20:01:37 -0400, Joe Gwinn <joeg...@comcast.net>
wrote:
>> Turpentine is a bad idea. It's what is removed from the tree sap to
>> make gum rosin. The turpentine is hygroscopic (absorbs moisture) and
>> will make a great humidity meter out of your circuit. At best, it
>> will soften the rosin allowing you to smear it all over the PCB,
>> producing a sticky mess.
>The book did call terpenes out as the solvent to use. The hot water
>and detergent wash removed the residue.
I beg to differ. It's easy enough to test. Take a blank PCB or sheet
of window glass (I prefer the glass). Smear on some paste flux. Bake
in place with a hot air gun. At not time from this point on do you
scrape or clean off the surface of the PCB or glass plate. Everything
has to be done by chemical action.
Immerse the board or glass plate into terpentine. Soak or rinse in
some manner that would resemble what you normally do to a PCB. Allow
to dry. Then, wash with hot water, and allow to dry. When done, do a
resistivity test and a visual microscope test. My guess(tm) is that
you'll have a thin and sticky coating of dissolved rosin flux.
Ah, better idea... Mix some phosphor dye tracer into the flux. Use a
UV flashlight to see if there is any residue. The automotive oil type
of tracer (not the water or gasoline types) should work.
<http://www.amazon.com/gp/product/B002M4G24U>
or, just toss in some yellow phosophor powder into the flux.
<http://www.ebay.com/itm/181797528638>
UV flashlight (also handy for finding where the cat has marked its
territory and where the mice have been hanging out):
<http://www.ebay.com/itm/381341603320>
Note: Laundry detergent is full of phosphors, but the soap and
detergent action might ruin the test.
>> <http://802.11junk.com/jeffl/pics/AN-SAR-4B%20night%20vision/index.html>
>Maybe a smaller leak resistor would break you of the habit - ZAP!
Been there, done that, and trust me, it really hurts. The last time I
got fried by that power supply (about a year ago), I was shaking for
several hours. I couldn't type or play piano for about a day.
I never make the same mistake twice. Five or six times is more my
style.
More drivel and welcome to "Learn by Destroying". Somewhere in my "to
be fixed, tossed, recycled, or sold" pile is a genuine "Megger". Mine
is the really ancient variety with a hand cranked generator. Something
like this but with some added goodies and a rotting leather case:
<http://www.richardsradios.co.uk/megger.html>
<https://capturedsunlight.wordpress.com/2011/10/14/evershed-vignoles-500volt-megger/>
The device is suitable for measuring insulation leakage and doing the
inquisition routine on non-paying clients. The important lesson that
it taught me is that dirt is conductive. 1000 volts will follow the
path of least resistance, which is usually the dirt, and not the
insulated test leads. I have successfully electrocuted myself (and
for amusement, one former friend), with this device. Perhaps some day
I'll clean it, but meanwhile, I wear thick rubber insulated gloves.
wrote:
>> Turpentine is a bad idea. It's what is removed from the tree sap to
>> make gum rosin. The turpentine is hygroscopic (absorbs moisture) and
>> will make a great humidity meter out of your circuit. At best, it
>> will soften the rosin allowing you to smear it all over the PCB,
>> producing a sticky mess.
>The book did call terpenes out as the solvent to use. The hot water
>and detergent wash removed the residue.
of window glass (I prefer the glass). Smear on some paste flux. Bake
in place with a hot air gun. At not time from this point on do you
scrape or clean off the surface of the PCB or glass plate. Everything
has to be done by chemical action.
Immerse the board or glass plate into terpentine. Soak or rinse in
some manner that would resemble what you normally do to a PCB. Allow
to dry. Then, wash with hot water, and allow to dry. When done, do a
resistivity test and a visual microscope test. My guess(tm) is that
you'll have a thin and sticky coating of dissolved rosin flux.
Ah, better idea... Mix some phosphor dye tracer into the flux. Use a
UV flashlight to see if there is any residue. The automotive oil type
of tracer (not the water or gasoline types) should work.
<http://www.amazon.com/gp/product/B002M4G24U>
or, just toss in some yellow phosophor powder into the flux.
<http://www.ebay.com/itm/181797528638>
UV flashlight (also handy for finding where the cat has marked its
territory and where the mice have been hanging out):
<http://www.ebay.com/itm/381341603320>
Note: Laundry detergent is full of phosphors, but the soap and
detergent action might ruin the test.
>> <http://802.11junk.com/jeffl/pics/AN-SAR-4B%20night%20vision/index.html>
>Maybe a smaller leak resistor would break you of the habit - ZAP!
got fried by that power supply (about a year ago), I was shaking for
several hours. I couldn't type or play piano for about a day.
I never make the same mistake twice. Five or six times is more my
style.
More drivel and welcome to "Learn by Destroying". Somewhere in my "to
be fixed, tossed, recycled, or sold" pile is a genuine "Megger". Mine
is the really ancient variety with a hand cranked generator. Something
like this but with some added goodies and a rotting leather case:
<http://www.richardsradios.co.uk/megger.html>
<https://capturedsunlight.wordpress.com/2011/10/14/evershed-vignoles-500volt-megger/>
The device is suitable for measuring insulation leakage and doing the
inquisition routine on non-paying clients. The important lesson that
it taught me is that dirt is conductive. 1000 volts will follow the
path of least resistance, which is usually the dirt, and not the
insulated test leads. I have successfully electrocuted myself (and
for amusement, one former friend), with this device. Perhaps some day
I'll clean it, but meanwhile, I wear thick rubber insulated gloves.
Joe Gwinn
Jul 25, 2015, 9:11:42 PM7/25/15
to
In article <c0a8radgunnd7ovhq...@4ax.com>, Jeff
Well, I pulled this from a standard tome, in its third edition, so I
bet it does work. Not that we cannot sabotage it.
> >> <http://802.11junk.com/jeffl/pics/AN-SAR-4B%20night%20vision/index.html>
>
> >Maybe a smaller leak resistor would break you of the habit - ZAP!
>
> Been there, done that, and trust me, it really hurts. The last time I
> got fried by that power supply (about a year ago), I was shaking for
> several hours. I couldn't type or play piano for about a day.
>
> I never make the same mistake twice. Five or six times is more my
> style.
>
> More drivel and welcome to "Learn by Destroying". Somewhere in my "to
> be fixed, tossed, recycled, or sold" pile is a genuine "Megger". Mine
> is the really ancient variety with a hand cranked generator. Something
> like this but with some added goodies and a rotting leather case:
> <http://www.richardsradios.co.uk/megger.html>
>
> <https://capturedsunlight.wordpress.com/2011/10/14/evershed-vignoles-500volt-m
> egger/>
> The device is suitable for measuring insulation leakage and doing the
> inquisition routine on non-paying clients. The important lesson that
> it taught me is that dirt is conductive. 1000 volts will follow the
> path of least resistance, which is usually the dirt, and not the
> insulated test leads. I have successfully electrocuted myself (and
> for amusement, one former friend), with this device. Perhaps some day
> I'll clean it, but meanwhile, I wear thick rubber insulated gloves.
Former friend ... Hmm ... I don't think I should ask.
Joe Gwinn
bet it does work. Not that we cannot sabotage it.
> >> <http://802.11junk.com/jeffl/pics/AN-SAR-4B%20night%20vision/index.html>
>
> >Maybe a smaller leak resistor would break you of the habit - ZAP!
>
> Been there, done that, and trust me, it really hurts. The last time I
> got fried by that power supply (about a year ago), I was shaking for
> several hours. I couldn't type or play piano for about a day.
>
> I never make the same mistake twice. Five or six times is more my
> style.
>
> More drivel and welcome to "Learn by Destroying". Somewhere in my "to
> be fixed, tossed, recycled, or sold" pile is a genuine "Megger". Mine
> is the really ancient variety with a hand cranked generator. Something
> like this but with some added goodies and a rotting leather case:
> <http://www.richardsradios.co.uk/megger.html>
>
> <https://capturedsunlight.wordpress.com/2011/10/14/evershed-vignoles-500volt-m
> egger/>
> The device is suitable for measuring insulation leakage and doing the
> inquisition routine on non-paying clients. The important lesson that
> it taught me is that dirt is conductive. 1000 volts will follow the
> path of least resistance, which is usually the dirt, and not the
> insulated test leads. I have successfully electrocuted myself (and
> for amusement, one former friend), with this device. Perhaps some day
> I'll clean it, but meanwhile, I wear thick rubber insulated gloves.
Joe Gwinn
Jeff Liebermann
Jul 25, 2015, 9:12:22 PM7/25/15
to
On Sat, 25 Jul 2015 19:56:47 -0400, Joe Gwinn <joeg...@comcast.net>
wrote:
>You also need the second step, to wash in hot water with AlcoJet
>detergent.
We just used dishwasher detergent (in a dishwasher full of PC boards,
of course).
<http://www.2spi.com/catalog/supp/Alcojet-powder-detergent.php>
From the MSDS sheet:
Sodium Carbonate 15-40%
(soda ash or washing soda)
Sodium Metasilicate 5-10%
(strong base that reacts with fatty acids to form a soap)
Tetrasodium Pyrophosphate 3-7%
(removes calcium and magnesium scum)
Sodium Phosphate 14-40%
(probably similar to TSP or tri-sodium phosphate to remove grease)
Looks very much like dishwashing detergent powder, which is mostly
sodium carbonate and sodium silicate. I guess the two phosphates
might be an added bonus if your water is full of lime or your flux
uses a water soluable grease.
wrote:
>You also need the second step, to wash in hot water with AlcoJet
>detergent.
of course).
<http://www.2spi.com/catalog/supp/Alcojet-powder-detergent.php>
From the MSDS sheet:
Sodium Carbonate 15-40%
(soda ash or washing soda)
Sodium Metasilicate 5-10%
(strong base that reacts with fatty acids to form a soap)
Tetrasodium Pyrophosphate 3-7%
(removes calcium and magnesium scum)
Sodium Phosphate 14-40%
(probably similar to TSP or tri-sodium phosphate to remove grease)
Looks very much like dishwashing detergent powder, which is mostly
sodium carbonate and sodium silicate. I guess the two phosphates
might be an added bonus if your water is full of lime or your flux
uses a water soluable grease.
Joe Gwinn
Jul 25, 2015, 9:16:09 PM7/25/15
to
In article <ri98radc423jpso9e...@4ax.com>, John Larkin
> .<https://dl.dropboxusercontent.com/u/53724080/Gear/Keithley/Leak_Gloppy_Flux.JP
> G>
>
>.<https://dl.dropboxusercontent.com/u/53724080/Gear/Keithley/Leak_Test.
JPG>
circuit boards is a common theme in the electrometer crowd.
> We have recently had some problems on some analog acquisition boards,
> water soluble flux and water (saponifier and then multiple rinses in
> hi-Z water) wash. Conductive stuff likes to hide under CSP/QFN
> packages.
Yeah. In the 2013 thread, this came up, and the advice was to ensure
that the mechanical design gave adequate space under the components to
allow free flow of the cleaning solutions, for precisely this reason.
Joe Gwinn
> G>
>
>.<https://dl.dropboxusercontent.com/u/53724080/Gear/Keithley/Leak_Test.
JPG>
>
> and pins the meter on the 1e14 ohm range.
Yeah, I remember that test. But leakage through residue and dirt on
> and pins the meter on the 1e14 ohm range.
circuit boards is a common theme in the electrometer crowd.
> We have recently had some problems on some analog acquisition boards,
> water soluble flux and water (saponifier and then multiple rinses in
> hi-Z water) wash. Conductive stuff likes to hide under CSP/QFN
> packages.
that the mechanical design gave adequate space under the components to
allow free flow of the cleaning solutions, for precisely this reason.
Joe Gwinn
rickman
Jul 25, 2015, 9:50:02 PM7/25/15
to
On 7/25/2015 9:12 PM, Jeff Liebermann wrote:
> On Sat, 25 Jul 2015 19:56:47 -0400, Joe Gwinn <joeg...@comcast.net>
> wrote:
>
>> You also need the second step, to wash in hot water with AlcoJet
>> detergent.
>
> We just used dishwasher detergent (in a dishwasher full of PC boards,
> of course).
> <http://www.2spi.com/catalog/supp/Alcojet-powder-detergent.php>
> From the MSDS sheet:
>
> Sodium Carbonate 15-40%
> (soda ash or washing soda)
>
> Sodium Metasilicate 5-10%
> (strong base that reacts with fatty acids to form a soap)
>
> Tetrasodium Pyrophosphate 3-7%
> (removes calcium and magnesium scum)
>
> Sodium Phosphate 14-40%
> (probably similar to TSP or tri-sodium phosphate to remove grease)
>
> Looks very much like dishwashing detergent powder, which is mostly
> sodium carbonate and sodium silicate. I guess the two phosphates
> might be an added bonus if your water is full of lime or your flux
> uses a water soluable grease.
One of the problems with commercial grade chemicals is purity. These
> On Sat, 25 Jul 2015 19:56:47 -0400, Joe Gwinn <joeg...@comcast.net>
> wrote:
>
>> You also need the second step, to wash in hot water with AlcoJet
>> detergent.
>
> We just used dishwasher detergent (in a dishwasher full of PC boards,
> of course).
> <http://www.2spi.com/catalog/supp/Alcojet-powder-detergent.php>
> From the MSDS sheet:
>
> Sodium Carbonate 15-40%
> (soda ash or washing soda)
>
> Sodium Metasilicate 5-10%
> (strong base that reacts with fatty acids to form a soap)
>
> Tetrasodium Pyrophosphate 3-7%
> (removes calcium and magnesium scum)
>
> Sodium Phosphate 14-40%
> (probably similar to TSP or tri-sodium phosphate to remove grease)
>
> Looks very much like dishwashing detergent powder, which is mostly
> sodium carbonate and sodium silicate. I guess the two phosphates
> might be an added bonus if your water is full of lime or your flux
> uses a water soluable grease.
are the listed ingredients but there are often contaminants that are not
listed. I don't know how important any of them are in this application.
In chemistry it was not at all unusual to refine your chemicals before
using them for research, but that greatly depended on the research and
the documentation detail available for the impurities. That was also
not trusted much and verified.
Any idea what contaminants would matter here? Sure seems like H2O is
the one of most concern. Heck, even the water used would have numerous
contaminants.
--
Rick
DecadentLinuxUserNumeroUno
Jul 25, 2015, 9:55:49 PM7/25/15
to
On Sat, 25 Jul 2015 21:16:04 -0400, Joe Gwinn <joeg...@comcast.net>
Gave us:
>Yeah, I remember that test. But leakage through residue and dirt on
>circuit boards is a common theme in the electrometer crowd.
mere "coffee breath" can cause a failure mode.
Gave us:
>Yeah, I remember that test. But leakage through residue and dirt on
>circuit boards is a common theme in the electrometer crowd.
Jeff Liebermann
Jul 25, 2015, 10:58:26 PM7/25/15
to
dishwasher detergent that caused problems in the past.
Sodium Dichloro-S-Triazinetrione dihydrate:
<https://en.wikipedia.org/wiki/Sodium_dichloroisocyanurate>
It's a chlorine based disinfectant and bug killer. That's quite
useful in a dishwasher full of rotting food residue, but not terribly
helpful when cleaning PCB's. The problem was that even in such low
concentrations (about 1%), it makes a dandy bleach and was fairly good
at removing the markings off components and the rubber inspection
stamps off the PCB's. It also seemed to cause the Chemask peelable
solder mask to prematurely fall off the PCB. I could find no
conductivity or residue issues, just some odd irritations. I found a
totally functional, but highly irritating method of neutralizing the
compound. I dumped a weak acid (acetic acid or white vinegar) into
the dishwasher mixer. That got rid of the disappearing markings and
having to fish out the Chemask from the bottom of the dishwasher, but
also filled the production area with toxic chlorine gas covered by the
smell of wet athletic socks. Production declared my solution
unacceptable and found a supplier that did not use chlorine compounds
in their soap mix.
> In chemistry it was not at all unusual to refine your chemicals before
>using them for research, but that greatly depended on the research and
>the documentation detail available for the impurities. That was also
>not trusted much and verified.
However, I have no experience with producing the original compounds
and don't know how much care is taken in removing or even identifying
contaminants.
>Any idea what contaminants would matter here? Sure seems like H2O is
>the one of most concern. Heck, even the water used would have numerous
>contaminants.
problem. Some of the junk found in the water is potentially a problem
especially since I considered Santa Clara CA tap water undrinkable and
unsuitable for decent coffee or tea.
We had a high flow water filter before the dishwasher that was good
for removing boulder size contaminants, but did nothing for dissolved
chemicals and pollutants. I also didn't have a proper lab for
analyzing what was in the water.
I did manage to create a big problem when I let the dish washer drain
the hot water heater, which pumped all the calcium carbonate from the
bottom of the tank into the dishwasher. The PCB's looked like they
were covered with white paint. I managed to recover most of the
boards with a smelly white vinegar rinse, to produce calcium acetate,
carbon dioxide, and more water. By itself, calcium acetate is fairly
harmless and somewhat soluble in water. So, I tried giving the boards
a rinse in an organic solvent. Big mistake. Mixing alcohol and
calcium acetate produces a white, slimy, sticky, and smelly gel, that
refused to be removed by anything less than explosives. Ok, lesson
learned.
Anyway, if you're trying to get down to megaohms per square sheet
resistivity, things like contaminants are important. However, if your
circuit can tolerate less, the contaminants are much less of a
problem. I've been fortunately and only had to deal with fair low
impedance designs that don't have such problems. However, if it is a
problem, you're probably better off etching a guard ring around op amp
inputs than trying to permanently clean the PCB soldering process.
Marginally related but interesting stuff:
Design femtoampere circuits with low leakage, part one
<http://www.edn.com/design/analog/4368681/2/Design-femtoampere-circuits-with-low-leakage-part-one>
INVESTIGATION OF FACTORS THAT INFLUENCE CREEP CORROSION ON PRINTED
CIRCUIT BOARDS
<http://thor.inemi.org/webdownload/Pres/SMTA_Pan_Pacific-2012/Creep_Corr_paper.pdf>
"The present work has shown that the presence of organic
acid flux residue is the single biggest contributor to
copper creep corrosion".
Joe Gwinn
Jul 25, 2015, 11:13:44 PM7/25/15
to
In article <57c8rad7694g5p4h8...@4ax.com>, Jeff
> <http://www.2spi.com/catalog/supp/Alcojet-powder-detergent.php>
> From the MSDS sheet:
>
> Sodium Carbonate 15-40%
> (soda ash or washing soda)
>
> Sodium Metasilicate 5-10%
> (strong base that reacts with fatty acids to form a soap)
>
> Tetrasodium Pyrophosphate 3-7%
> (removes calcium and magnesium scum)
>
> Sodium Phosphate 14-40%
> (probably similar to TSP or tri-sodium phosphate to remove grease)
>
> Looks very much like dishwashing detergent powder, which is mostly
> sodium carbonate and sodium silicate. I guess the two phosphates
> might be an added bonus if your water is full of lime or your flux
> uses a water soluable grease.
Sounds about right. It's pretty aggressive compared to most home
dishwashing detergents though, especially the recent phosphorus-free
ones.
Alconox has a number of formulations, so I'd call them and figure out
which is best for the purpose.
Joe Gwinn
Liebermann <je...@cruzio.com> wrote:
> On Sat, 25 Jul 2015 19:56:47 -0400, Joe Gwinn <joeg...@comcast.net>
> wrote:
>
> >You also need the second step, to wash in hot water with AlcoJet
> >detergent.
>
> We just used dishwasher detergent (in a dishwasher full of PC boards,
> of course).
Which specific detergent do you use?
> On Sat, 25 Jul 2015 19:56:47 -0400, Joe Gwinn <joeg...@comcast.net>
> wrote:
>
> >You also need the second step, to wash in hot water with AlcoJet
> >detergent.
>
> We just used dishwasher detergent (in a dishwasher full of PC boards,
> of course).
> <http://www.2spi.com/catalog/supp/Alcojet-powder-detergent.php>
> From the MSDS sheet:
>
> Sodium Carbonate 15-40%
> (soda ash or washing soda)
>
> Sodium Metasilicate 5-10%
> (strong base that reacts with fatty acids to form a soap)
>
> Tetrasodium Pyrophosphate 3-7%
> (removes calcium and magnesium scum)
>
> Sodium Phosphate 14-40%
> (probably similar to TSP or tri-sodium phosphate to remove grease)
>
> Looks very much like dishwashing detergent powder, which is mostly
> sodium carbonate and sodium silicate. I guess the two phosphates
> might be an added bonus if your water is full of lime or your flux
> uses a water soluable grease.
dishwashing detergents though, especially the recent phosphorus-free
ones.
Alconox has a number of formulations, so I'd call them and figure out
which is best for the purpose.
Joe Gwinn
Dave Platt
Jul 25, 2015, 11:47:30 PM7/25/15
to
>Looks very much like dishwashing detergent powder, which is mostly
>sodium carbonate and sodium silicate. I guess the two phosphates
>might be an added bonus if your water is full of lime or your flux
>uses a water soluable grease.
Bob Pease used to swear by Calgonite, which is much the same formula.
>sodium carbonate and sodium silicate. I guess the two phosphates
>might be an added bonus if your water is full of lime or your flux
>uses a water soluable grease.
If I recall correctly: standard load of Calgonite, normal wash and
rinse, then rinse down by hand with deionized water, shake off excess
water, rack up the boards on edge to air-dry.
He wrote that this resulted in lower board leakage than the
organic-solvent board cleaning protocols.
Jeff Liebermann
Jul 25, 2015, 11:51:40 PM7/25/15
to
On Sat, 25 Jul 2015 23:13:41 -0400, Joe Gwinn <joeg...@comcast.net>
wrote:
>Which specific detergent do you use?
I don't recall exactly. This was during the 1970's so please forgive
my lack of total recall. As I vaguely recall, it was purchased in 55
gallon drums from some industrial supplier for use in restaurant and
cafeteria kitchens. Production later changed to a different product
in order to remove the chlorine compounds.
>> <http://www.2spi.com/catalog/supp/Alcojet-powder-detergent.php>
>> From the MSDS sheet:
>>
>> Sodium Carbonate 15-40%
>> (soda ash or washing soda)
>>
>> Sodium Metasilicate 5-10%
>> (strong base that reacts with fatty acids to form a soap)
>>
>> Tetrasodium Pyrophosphate 3-7%
>> (removes calcium and magnesium scum)
>>
>> Sodium Phosphate 14-40%
>> (probably similar to TSP or tri-sodium phosphate to remove grease)
>>
>> Looks very much like dishwashing detergent powder, which is mostly
>> sodium carbonate and sodium silicate. I guess the two phosphates
>> might be an added bonus if your water is full of lime or your flux
>> uses a water soluable grease.
>Sounds about right. It's pretty aggressive compared to most home
>dishwashing detergents though, especially the recent phosphorus-free
>ones.
The phosphate alternatives are typically zeolites, sodium carbonate,
nitrilo-triacetic acid, and citric acid. There are some other
formulations that are being tested or used.
Note that the formulation already has considerable sodium carbonate.
The citric acid is where the "lemon fresh" advertising mantra
originated. However, in the US, the phosphate restrictions apply
mostly to consumer products, because the substitutes don't work as
well as the real thing.
Here's a summary of the situation:
<http://www.icis.com/resources/news/2009/01/12/9182061/detergents-shift-to-greener-builders/>
>Alconox has a number of formulations, so I'd call them and figure out
>which is best for the purpose.
Make sure that it includes a surfactant to reduce surface tension. In
the dishwasher, it reduces water spots and hard water stains on the
dishes and PCB's. It can be added to the rinse while washing. I used
only a few drops of Kodak Photo Flo for the purpose:
<http://www.kodak.com/global/en/professional/products/chemistry/bwFilmProcessing/photoFloSolution.jhtml>
which is:
Propylene glycol 25-30%
(anti-freeze)
Octylphenoxypolyethoxyethanol 5-10%
(Triton X-100 non-ionic surfactant)
phone call from paying customer... gone.
wrote:
>Which specific detergent do you use?
my lack of total recall. As I vaguely recall, it was purchased in 55
gallon drums from some industrial supplier for use in restaurant and
cafeteria kitchens. Production later changed to a different product
in order to remove the chlorine compounds.
>> <http://www.2spi.com/catalog/supp/Alcojet-powder-detergent.php>
>> From the MSDS sheet:
>>
>> Sodium Carbonate 15-40%
>> (soda ash or washing soda)
>>
>> Sodium Metasilicate 5-10%
>> (strong base that reacts with fatty acids to form a soap)
>>
>> Tetrasodium Pyrophosphate 3-7%
>> (removes calcium and magnesium scum)
>>
>> Sodium Phosphate 14-40%
>> (probably similar to TSP or tri-sodium phosphate to remove grease)
>>
>> Looks very much like dishwashing detergent powder, which is mostly
>> sodium carbonate and sodium silicate. I guess the two phosphates
>> might be an added bonus if your water is full of lime or your flux
>> uses a water soluable grease.
>Sounds about right. It's pretty aggressive compared to most home
>dishwashing detergents though, especially the recent phosphorus-free
>ones.
nitrilo-triacetic acid, and citric acid. There are some other
formulations that are being tested or used.
Note that the formulation already has considerable sodium carbonate.
The citric acid is where the "lemon fresh" advertising mantra
originated. However, in the US, the phosphate restrictions apply
mostly to consumer products, because the substitutes don't work as
well as the real thing.
Here's a summary of the situation:
<http://www.icis.com/resources/news/2009/01/12/9182061/detergents-shift-to-greener-builders/>
>Alconox has a number of formulations, so I'd call them and figure out
>which is best for the purpose.
the dishwasher, it reduces water spots and hard water stains on the
dishes and PCB's. It can be added to the rinse while washing. I used
only a few drops of Kodak Photo Flo for the purpose:
<http://www.kodak.com/global/en/professional/products/chemistry/bwFilmProcessing/photoFloSolution.jhtml>
which is:
Propylene glycol 25-30%
(anti-freeze)
Octylphenoxypolyethoxyethanol 5-10%
(Triton X-100 non-ionic surfactant)
phone call from paying customer... gone.
Phil Allison
Jul 25, 2015, 11:53:26 PM7/25/15
to
Joe Gwinn wrote:
> This is a follow-on to the "Reverse polarity,
> Scotty" thread of September 2013, where the issue
> was how to clean a circuit board of soldering flux
> residue well enough for a 50 Gigaohm node to work.
>
** Looks like a fool's errand to me.
> This is a follow-on to the "Reverse polarity,
> Scotty" thread of September 2013, where the issue
> was how to clean a circuit board of soldering flux
> residue well enough for a 50 Gigaohm node to work.
>
FYI:
Inside a typical condenser microphone is a node where the mic element (effectively a capacitor of about 50pF) connects to the gate of a JFET or the grid of a small triode. To maintain response down to 20Hz and minimise noise, resistors of 1 to 2Gohms are employed to supply around 50-100V DC bias the element and about 1.5V DC to the gate or grid involved.
Any leakage current from one PCB trace to another would upset bias conditions and/or add noise, which needs to be kept sub 1uVrms at this point.
Normal PCB materials, cannot be relied on so the simple solution is to lift the node proud of the PCB and join the parts in mid air, then coat with quick drying lacquer to keep out moisture.
BTW:
A 1Gohm resistor has over 500uV of thermal noise in the audio band, which the 50pF capacitance of the element attenuates to under 1uV.
... Phil
John Larkin
Jul 26, 2015, 12:20:28 AM7/26/15
to
On Sat, 25 Jul 2015 20:51:51 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:
You can buy phosphate-loaded dishwash detergent online, and it works a
lot better than the greenie stuff. I've only found the powder, not the
tablets.
wrote:
lot better than the greenie stuff. I've only found the powder, not the
tablets.
Jeff Liebermann
Jul 26, 2015, 1:33:02 AM7/26/15
to
On Sat, 25 Jul 2015 20:45:00 -0700, dpl...@coop.radagast.org (Dave
Platt) wrote:
>In article <57c8rad7694g5p4h8...@4ax.com>,
>Jeff Liebermann <je...@cruzio.com> wrote:
>
>>Looks very much like dishwashing detergent powder, which is mostly
>>sodium carbonate and sodium silicate. I guess the two phosphates
>>might be an added bonus if your water is full of lime or your flux
>>uses a water soluable grease.
>Bob Pease used to swear by Calgonite, which is much the same formula.
>If I recall correctly: standard load of Calgonite, normal wash and
>rinse, then rinse down by hand with deionized water, shake off excess
>water, rack up the boards on edge to air-dry.
We used filtered tap water. Not as good as deionized or
Platt) wrote:
>In article <57c8rad7694g5p4h8...@4ax.com>,
>Jeff Liebermann <je...@cruzio.com> wrote:
>
>>Looks very much like dishwashing detergent powder, which is mostly
>>sodium carbonate and sodium silicate. I guess the two phosphates
>>might be an added bonus if your water is full of lime or your flux
>>uses a water soluable grease.
>Bob Pease used to swear by Calgonite, which is much the same formula.
>If I recall correctly: standard load of Calgonite, normal wash and
>rinse, then rinse down by hand with deionized water, shake off excess
>water, rack up the boards on edge to air-dry.
demineralized, but good enough for our requirements. We also hit the
rack of PCB's with filtered and dried compressed air to speed up
drying.
>He wrote that this resulted in lower board leakage than the
>organic-solvent board cleaning protocols.
<http://www.rbnainfo.com/MSDS/CA/Calgonite_CAN.pdf>
SODIUM TRIPOLYPHOSPHATE DENSE ANHYDROUS 12-15%
SODIUM SULFATE ANHYDROUS 40-45%
SODIUM CARBONATE DENSE 35-40%
SODIUM SILICATE 2.4R 42% 5-10%
SODIUM DICHLOROISOCYANURATE 0-1%
The difference is the STPP detergent, which is partially banned in 17
states in consumer products, and voluntarily by major manufacturers,
but not industrial products:
<http://www.npr.org/2010/12/15/132072122/it-s-not-your-fault-your-dishes-are-still-dirty>
<http://laundry.reviewed.com/news/procter-and-gamble-removes-phosphates-from-entire-laundry-detergent-line>
krw
Jul 26, 2015, 9:56:49 AM7/26/15
to
Phil Hobbs
Jul 26, 2015, 10:49:52 AM7/26/15
to
Chemically-amplified resist is very sensitive to amines, which prevent
it from developing. (My stuff was all 248-nm, not the modern stuff.)
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC
Optics, Electro-optics, Photonics, Analog Electronics
160 North State Road #203
Briarcliff Manor NY 10510
hobbs at electrooptical dot net
http://electrooptical.net
Jeff Liebermann
Jul 26, 2015, 11:16:56 AM7/26/15
to
On Sun, 26 Jul 2015 09:56:42 -0400, krw <k...@nowhere.com> wrote:
>Or you can add TSP to the greenie stuff to make it useful again.
Bad idea. TSP produces a precipitate when it reacts with the minerals
>Or you can add TSP to the greenie stuff to make it useful again.
in hard water. You want STPP (sodium tripolyphosphate). Check out
stores that sell soap making supplies:
<http://www.chemistrystore.com/Chemicals_S-Z-Sodium_Tripolyphosphate.html>
<http://www.ebay.com/itm/261447174683>
Note that this is a concentrate. Even the most phosphate loaded
laundry detergent contains no more than about 15% STPP, so don't dump
in too much.
Storage of STPP is also a bit of a problem:
"STPP has one weakness, and that is that over time, with
exposure to water, it will decompose into a mono-phosphate,
or "orthophosphate", called trisodiumphosphate, or TSP. TSP
is often used for cleaning hard surfaces where a precipitate
is not a problem, but due to its precipitate formation is
not favored for laundry use."
Get some now, before it's banned.
Joe Gwinn
Jul 26, 2015, 11:55:27 AM7/26/15
to
In article <gmq8rahien4uqbbtn...@4ax.com>, Jeff
In all the justification for elimination of phosphate from detergents
(laundry and dishwashing), a critical piece of information has been
omitted: Detergents account for no more than 0.5% of phosphate use.
The bulk is used in fertilizers - food just won't grow otherwise. It
is runoff from farms that causes eutrophication.
.<http://www.potashcorp.com/overview/nutrients/phosphate/overview/world-
phosphate-acid-uses>
Joe Gwinn
(laundry and dishwashing), a critical piece of information has been
omitted: Detergents account for no more than 0.5% of phosphate use.
The bulk is used in fertilizers - food just won't grow otherwise. It
is runoff from farms that causes eutrophication.
.<http://www.potashcorp.com/overview/nutrients/phosphate/overview/world-
phosphate-acid-uses>
Joe Gwinn
John Larkin
Jul 26, 2015, 12:58:29 PM7/26/15
to
On Sun, 26 Jul 2015 10:49:52 -0400, Phil Hobbs
<ho...@electrooptical.net> wrote:
>On 7/25/2015 9:55 PM, DecadentLinuxUserNumeroUno wrote:
>> On Sat, 25 Jul 2015 21:16:04 -0400, Joe Gwinn <joeg...@comcast.net>
>> Gave us:
>>
>>> Yeah, I remember that test. But leakage through residue and dirt on
>>> circuit boards is a common theme in the electrometer crowd.
>>
>> mere "coffee breath" can cause a failure mode.
>>
>
>That's more of a problem in semiconductor lithography.
>Chemically-amplified resist is very sensitive to amines, which prevent
>it from developing. (My stuff was all 248-nm, not the modern stuff.)
>
Wafers tend to be transported in big sealed plastic casettes these
<ho...@electrooptical.net> wrote:
>On 7/25/2015 9:55 PM, DecadentLinuxUserNumeroUno wrote:
>> On Sat, 25 Jul 2015 21:16:04 -0400, Joe Gwinn <joeg...@comcast.net>
>> Gave us:
>>
>>> Yeah, I remember that test. But leakage through residue and dirt on
>>> circuit boards is a common theme in the electrometer crowd.
>>
>> mere "coffee breath" can cause a failure mode.
>>
>
>That's more of a problem in semiconductor lithography.
>Chemically-amplified resist is very sensitive to amines, which prevent
>it from developing. (My stuff was all 248-nm, not the modern stuff.)
>
days, and plugged into process machines. I don't see why anybody needs
clean rooms any more.
Phil Hobbs
Jul 26, 2015, 1:04:22 PM7/26/15
to
On 7/26/2015 12:58 PM, John Larkin wrote:
> On Sun, 26 Jul 2015 10:49:52 -0400, Phil Hobbs
> <ho...@electrooptical.net> wrote:
>
>> On 7/25/2015 9:55 PM, DecadentLinuxUserNumeroUno wrote:
>>> On Sat, 25 Jul 2015 21:16:04 -0400, Joe Gwinn <joeg...@comcast.net>
>>> Gave us:
>>>
>>>> Yeah, I remember that test. But leakage through residue and dirt on
>>>> circuit boards is a common theme in the electrometer crowd.
>>>
>>> mere "coffee breath" can cause a failure mode.
>>>
>>
>> That's more of a problem in semiconductor lithography.
>> Chemically-amplified resist is very sensitive to amines, which prevent
>> it from developing. (My stuff was all 248-nm, not the modern stuff.)
>>
>
> Wafers tend to be transported in big sealed plastic casettes these
> days, and plugged into process machines. I don't see why anybody needs
> clean rooms any more.
>
>
Belt and braces. You have to open the mini-environments at some stage,
> On Sun, 26 Jul 2015 10:49:52 -0400, Phil Hobbs
> <ho...@electrooptical.net> wrote:
>
>> On 7/25/2015 9:55 PM, DecadentLinuxUserNumeroUno wrote:
>>> On Sat, 25 Jul 2015 21:16:04 -0400, Joe Gwinn <joeg...@comcast.net>
>>> Gave us:
>>>
>>>> Yeah, I remember that test. But leakage through residue and dirt on
>>>> circuit boards is a common theme in the electrometer crowd.
>>>
>>> mere "coffee breath" can cause a failure mode.
>>>
>>
>> That's more of a problem in semiconductor lithography.
>> Chemically-amplified resist is very sensitive to amines, which prevent
>> it from developing. (My stuff was all 248-nm, not the modern stuff.)
>>
>
> Wafers tend to be transported in big sealed plastic casettes these
> days, and plugged into process machines. I don't see why anybody needs
> clean rooms any more.
>
>
and having them in a Class 1 clean room helps a lot.
Jeff Liebermann
Jul 26, 2015, 1:31:58 PM7/26/15
to
On Sun, 26 Jul 2015 11:55:22 -0400, Joe Gwinn <joeg...@comcast.net>
wrote:
>In all the justification for elimination of phosphate from detergents
>(laundry and dishwashing), a critical piece of information has been
>omitted: Detergents account for no more than 0.5% of phosphate use.
>The bulk is used in fertilizers - food just won't grow otherwise. It
>is runoff from farms that causes eutrophication.
><http://www.potashcorp.com/overview/nutrients/phosphate/overview/world-phosphate-acid-uses>
>Joe Gwinn
The above URL is only about phosphoric acid (and phosphate acid)
fertilizer and makes no mention of laundry detergents or other
phosphate bearing compounds (TSP, STPP, etc). Where did you find the
0.5% figure for detergent use?
I couldn't find anything more current or authoritative right now:
<http://www.colorado.edu/conflict/full_text_search/AllCRCDocs/94-54.htm>
The general feeling around the late 1960s was that the nation's
lakes and streams were getting more polluted each day, and phosphate
detergents were the primary reason. Half the phosphorus input to
Lakes Erie and Ontario came from municipal and industrial sources,
of which 50% to 70% came from detergents. Over half of the
phosphorus input to the Potomac estuary also came from detergents
in municipal and industrial effluents (Congressional Report HR
91-1004 April 14, 1970). It was generally agreed that detergents
accounted for about 50% of the wastewater phosphorus nationwide
(Hammond 1971). There was a growing public consensus that in
order to save lakes (like Lake Erie), phosphates must be banned
from detergents.
Your 0.5% figure might be true in farming areas, where phosphate
fertilizer laced runoff is more common, but in more densely populated
urban areas, the 50% figure cited above is more likely.
wrote:
>In all the justification for elimination of phosphate from detergents
>(laundry and dishwashing), a critical piece of information has been
>omitted: Detergents account for no more than 0.5% of phosphate use.
>The bulk is used in fertilizers - food just won't grow otherwise. It
>is runoff from farms that causes eutrophication.
>Joe Gwinn
The above URL is only about phosphoric acid (and phosphate acid)
fertilizer and makes no mention of laundry detergents or other
phosphate bearing compounds (TSP, STPP, etc). Where did you find the
0.5% figure for detergent use?
I couldn't find anything more current or authoritative right now:
<http://www.colorado.edu/conflict/full_text_search/AllCRCDocs/94-54.htm>
The general feeling around the late 1960s was that the nation's
lakes and streams were getting more polluted each day, and phosphate
detergents were the primary reason. Half the phosphorus input to
Lakes Erie and Ontario came from municipal and industrial sources,
of which 50% to 70% came from detergents. Over half of the
phosphorus input to the Potomac estuary also came from detergents
in municipal and industrial effluents (Congressional Report HR
91-1004 April 14, 1970). It was generally agreed that detergents
accounted for about 50% of the wastewater phosphorus nationwide
(Hammond 1971). There was a growing public consensus that in
order to save lakes (like Lake Erie), phosphates must be banned
from detergents.
Your 0.5% figure might be true in farming areas, where phosphate
fertilizer laced runoff is more common, but in more densely populated
urban areas, the 50% figure cited above is more likely.
rickman
Jul 26, 2015, 1:48:53 PM7/26/15
to
On 7/26/2015 12:58 PM, John Larkin wrote:
> On Sun, 26 Jul 2015 10:49:52 -0400, Phil Hobbs
> <ho...@electrooptical.net> wrote:
>
>> On 7/25/2015 9:55 PM, DecadentLinuxUserNumeroUno wrote:
>>> On Sat, 25 Jul 2015 21:16:04 -0400, Joe Gwinn <joeg...@comcast.net>
>>> Gave us:
>>>
>>>> Yeah, I remember that test. But leakage through residue and dirt on
>>>> circuit boards is a common theme in the electrometer crowd.
>>>
>>> mere "coffee breath" can cause a failure mode.
>>>
>>
>> That's more of a problem in semiconductor lithography.
>> Chemically-amplified resist is very sensitive to amines, which prevent
>> it from developing. (My stuff was all 248-nm, not the modern stuff.)
>>
>
> Wafers tend to be transported in big sealed plastic casettes these
> days, and plugged into process machines. I don't see why anybody needs
> clean rooms any more.
You claim that I pick on you unjustly. But it is your making comments
> <ho...@electrooptical.net> wrote:
>
>> On 7/25/2015 9:55 PM, DecadentLinuxUserNumeroUno wrote:
>>> On Sat, 25 Jul 2015 21:16:04 -0400, Joe Gwinn <joeg...@comcast.net>
>>> Gave us:
>>>
>>>> Yeah, I remember that test. But leakage through residue and dirt on
>>>> circuit boards is a common theme in the electrometer crowd.
>>>
>>> mere "coffee breath" can cause a failure mode.
>>>
>>
>> That's more of a problem in semiconductor lithography.
>> Chemically-amplified resist is very sensitive to amines, which prevent
>> it from developing. (My stuff was all 248-nm, not the modern stuff.)
>>
>
> Wafers tend to be transported in big sealed plastic casettes these
> days, and plugged into process machines. I don't see why anybody needs
> clean rooms any more.
like this that make you stick out like the proverbial nail. For an
otherwise intelligent person you say the dumbest things. Reminds me of
the Art Linkletter show.
--
Rick
rickman
Jul 26, 2015, 1:54:32 PM7/26/15
to
the high Z. This gives you a tiny glimpse into what it takes to purify
and process silicon for semiconductors.
--
Rick
rickman
Jul 26, 2015, 2:04:58 PM7/26/15
to
The rivers and lakes don't care where the pollution comes from. For
example the Potomac river drains 14,700 square miles of which perhaps
some 1000 to 2000 is urban.
I kayak the Potomac river and it is still not what many would call
"clean". I can't say what the phosphate pollution level is, but it
shows many signs of pollution nearly everywhere along the lower 100
miles including excrement floating along. The James river is not any
better. Once on a paddle my girl friend counted the condoms floating
by. On both of these rivers and many others in the area, it is not
recommended that you eat many of the fish.
--
Rick
krw
Jul 26, 2015, 3:18:16 PM7/26/15
to
On Sun, 26 Jul 2015 08:16:59 -0700, Jeff Liebermann <je...@cruzio.com>
wrote:
>On Sun, 26 Jul 2015 09:56:42 -0400, krw <k...@nowhere.com> wrote:
>
>>Or you can add TSP to the greenie stuff to make it useful again.
>
>Bad idea. TSP produces a precipitate when it reacts with the minerals
>in hard water. You want STPP (sodium tripolyphosphate). Check out
>stores that sell soap making supplies:
><http://www.chemistrystore.com/Chemicals_S-Z-Sodium_Tripolyphosphate.html>
><http://www.ebay.com/itm/261447174683>
>Note that this is a concentrate. Even the most phosphate loaded
>laundry detergent contains no more than about 15% STPP, so don't dump
>in too much.
>
>Storage of STPP is also a bit of a problem:
> "STPP has one weakness, and that is that over time, with
> exposure to water, it will decompose into a mono-phosphate,
> or "orthophosphate", called trisodiumphosphate, or TSP. TSP
> is often used for cleaning hard surfaces where a precipitate
> is not a problem, but due to its precipitate formation is
> not favored for laundry use."
It *is* favored for dishwasher use. Works great.
>Get some now, before it's banned.
It already is in weenie states.
wrote:
>On Sun, 26 Jul 2015 09:56:42 -0400, krw <k...@nowhere.com> wrote:
>
>>Or you can add TSP to the greenie stuff to make it useful again.
>
>Bad idea. TSP produces a precipitate when it reacts with the minerals
>in hard water. You want STPP (sodium tripolyphosphate). Check out
>stores that sell soap making supplies:
><http://www.chemistrystore.com/Chemicals_S-Z-Sodium_Tripolyphosphate.html>
><http://www.ebay.com/itm/261447174683>
>Note that this is a concentrate. Even the most phosphate loaded
>laundry detergent contains no more than about 15% STPP, so don't dump
>in too much.
>
>Storage of STPP is also a bit of a problem:
> "STPP has one weakness, and that is that over time, with
> exposure to water, it will decompose into a mono-phosphate,
> or "orthophosphate", called trisodiumphosphate, or TSP. TSP
> is often used for cleaning hard surfaces where a precipitate
> is not a problem, but due to its precipitate formation is
> not favored for laundry use."
>Get some now, before it's banned.
Joe Gwinn
Jul 26, 2015, 4:39:47 PM7/26/15
to
In article <kn5ara5lt6s6v4qo8...@4ax.com>, Jeff
agriculture, specifically as fertilizers, so right away we know that
detergents cannot be the main story - everything else accounts for only
10%.
The 0.5% came from research I did circa 2010 when everybody's
dishwasher suddenly failed to get glasses clean. In my case, the
initial symptom was a swamp smell, followed by milky glassware. I
figured it out before any glassware was ruined. (I imaging that
straight battery acid would have rescued the glassware, but I never had
to go that far.)
One use for AlcoJet was to clean the innards of the dishwasher, to get
rid of the smell. Worked the first time.
> I couldn't find anything more current or authoritative right now:
> <http://www.colorado.edu/conflict/full_text_search/AllCRCDocs/94-54.htm>
> The general feeling around the late 1960s was that the nation's
> lakes and streams were getting more polluted each day, and phosphate
> detergents were the primary reason. Half the phosphorus input to
> Lakes Erie and Ontario came from municipal and industrial sources,
> of which 50% to 70% came from detergents. Over half of the
> phosphorus input to the Potomac estuary also came from detergents
> in municipal and industrial effluents (Congressional Report HR
> 91-1004 April 14, 1970). It was generally agreed that detergents
> accounted for about 50% of the wastewater phosphorus nationwide
> (Hammond 1971). There was a growing public consensus that in
> order to save lakes (like Lake Erie), phosphates must be banned
> from detergents.
>
> Your 0.5% figure might be true in farming areas, where phosphate
> fertilizer laced runoff is more common, but in more densely populated
> urban areas, the 50% figure cited above is more likely.
The key bit of hidden-in-plain-sight misdirection is the qualifier
"wastewater". Runoff from agriculture is not considered wastewater,
and neither are "municipal and industrial sources", so the above
statements can be absolutely true, and yet be deeply misleading. When
I went looking for the *entire* phosphorus budget, I found the 0.5%
estimate.
I'll dig the cites up again.
Joe Gwinn
Liebermann <je...@cruzio.com> wrote:
> On Sun, 26 Jul 2015 11:55:22 -0400, Joe Gwinn <joeg...@comcast.net>
> wrote:
>
> >In all the justification for elimination of phosphate from detergents
> >(laundry and dishwashing), a critical piece of information has been
> >omitted: Detergents account for no more than 0.5% of phosphate use.
> >The bulk is used in fertilizers - food just won't grow otherwise. It
> >is runoff from farms that causes eutrophication.
>
> >><http://www.potashcorp.com/overview/nutrients/phosphate/overview/world-phosp
> >hate-acid-uses>
> >Joe Gwinn
>
> The above URL is only about phosphoric acid (and phosphate acid)
> fertilizer and makes no mention of laundry detergents or other
> phosphate bearing compounds (TSP, STPP, etc). Where did you find the
> 0.5% figure for detergent use?
The above URL showed that ~90% of phosphorus produced is used in
> On Sun, 26 Jul 2015 11:55:22 -0400, Joe Gwinn <joeg...@comcast.net>
> wrote:
>
> >In all the justification for elimination of phosphate from detergents
> >(laundry and dishwashing), a critical piece of information has been
> >omitted: Detergents account for no more than 0.5% of phosphate use.
> >The bulk is used in fertilizers - food just won't grow otherwise. It
> >is runoff from farms that causes eutrophication.
>
> >><http://www.potashcorp.com/overview/nutrients/phosphate/overview/world-phosp
> >hate-acid-uses>
> >Joe Gwinn
>
> The above URL is only about phosphoric acid (and phosphate acid)
> fertilizer and makes no mention of laundry detergents or other
> phosphate bearing compounds (TSP, STPP, etc). Where did you find the
> 0.5% figure for detergent use?
agriculture, specifically as fertilizers, so right away we know that
detergents cannot be the main story - everything else accounts for only
10%.
The 0.5% came from research I did circa 2010 when everybody's
dishwasher suddenly failed to get glasses clean. In my case, the
initial symptom was a swamp smell, followed by milky glassware. I
figured it out before any glassware was ruined. (I imaging that
straight battery acid would have rescued the glassware, but I never had
to go that far.)
One use for AlcoJet was to clean the innards of the dishwasher, to get
rid of the smell. Worked the first time.
> I couldn't find anything more current or authoritative right now:
> <http://www.colorado.edu/conflict/full_text_search/AllCRCDocs/94-54.htm>
> The general feeling around the late 1960s was that the nation's
> lakes and streams were getting more polluted each day, and phosphate
> detergents were the primary reason. Half the phosphorus input to
> Lakes Erie and Ontario came from municipal and industrial sources,
> of which 50% to 70% came from detergents. Over half of the
> phosphorus input to the Potomac estuary also came from detergents
> in municipal and industrial effluents (Congressional Report HR
> 91-1004 April 14, 1970). It was generally agreed that detergents
> accounted for about 50% of the wastewater phosphorus nationwide
> (Hammond 1971). There was a growing public consensus that in
> order to save lakes (like Lake Erie), phosphates must be banned
> from detergents.
>
> Your 0.5% figure might be true in farming areas, where phosphate
> fertilizer laced runoff is more common, but in more densely populated
> urban areas, the 50% figure cited above is more likely.
"wastewater". Runoff from agriculture is not considered wastewater,
and neither are "municipal and industrial sources", so the above
statements can be absolutely true, and yet be deeply misleading. When
I went looking for the *entire* phosphorus budget, I found the 0.5%
estimate.
I'll dig the cites up again.
Joe Gwinn
rickman
Jul 26, 2015, 5:50:15 PM7/26/15
to
On 7/26/2015 4:39 PM, Joe Gwinn wrote:
> In article <kn5ara5lt6s6v4qo8...@4ax.com>, Jeff
> Liebermann <je...@cruzio.com> wrote:
>
>> On Sun, 26 Jul 2015 11:55:22 -0400, Joe Gwinn <joeg...@comcast.net>
>> wrote:
>>
>>> In all the justification for elimination of phosphate from detergents
>>> (laundry and dishwashing), a critical piece of information has been
>>> omitted: Detergents account for no more than 0.5% of phosphate use.
>>> The bulk is used in fertilizers - food just won't grow otherwise. It
>>> is runoff from farms that causes eutrophication.
>>
>>>> <http://www.potashcorp.com/overview/nutrients/phosphate/overview/world-phosp
>>> hate-acid-uses>
>>> Joe Gwinn
>>
>> The above URL is only about phosphoric acid (and phosphate acid)
>> fertilizer and makes no mention of laundry detergents or other
>> phosphate bearing compounds (TSP, STPP, etc). Where did you find the
>> 0.5% figure for detergent use?
>
> The above URL showed that ~90% of phosphorus produced is used in
> agriculture, specifically as fertilizers, so right away we know that
> detergents cannot be the main story - everything else accounts for only
> 10%.
I won't argue that your conclusion is wrong, but your logic is clearly
> In article <kn5ara5lt6s6v4qo8...@4ax.com>, Jeff
> Liebermann <je...@cruzio.com> wrote:
>
>> On Sun, 26 Jul 2015 11:55:22 -0400, Joe Gwinn <joeg...@comcast.net>
>> wrote:
>>
>>> In all the justification for elimination of phosphate from detergents
>>> (laundry and dishwashing), a critical piece of information has been
>>> omitted: Detergents account for no more than 0.5% of phosphate use.
>>> The bulk is used in fertilizers - food just won't grow otherwise. It
>>> is runoff from farms that causes eutrophication.
>>
>>>> <http://www.potashcorp.com/overview/nutrients/phosphate/overview/world-phosp
>>> hate-acid-uses>
>>> Joe Gwinn
>>
>> The above URL is only about phosphoric acid (and phosphate acid)
>> fertilizer and makes no mention of laundry detergents or other
>> phosphate bearing compounds (TSP, STPP, etc). Where did you find the
>> 0.5% figure for detergent use?
>
> The above URL showed that ~90% of phosphorus produced is used in
> agriculture, specifically as fertilizers, so right away we know that
> detergents cannot be the main story - everything else accounts for only
> 10%.
flawed. When you use phosphates for cleaning nearly 100% of it ends up
in our waters. Agricultural use has a portion which runs off into
streams. I don't know what percentage that is, but that number is
needed before you can say agricultural runoff is a bigger problem than
cleaners.
--
Rick
Jeff Liebermann
Jul 26, 2015, 5:58:08 PM7/26/15
to
On Sun, 26 Jul 2015 16:39:40 -0400, Joe Gwinn <joeg...@comcast.net>
wrote:
This might help, although there's little mention of phosphate
detergent use:
"Phosphorus in agriculture, Problems and solutions"
<http://www.greenpeace.to/greenpeace/wp-content/uploads/2012/06/tirado-and-allsopp-2012-phosphorus-in-agriculture-technical-report-02-2012.pdf>
A few quotes:
Agriculture is by far the main user of mined phosphorus globally,
accounting for between 80-90% of the total world demand (Childers
et al, 2011). However, only about 20% of the phosphorus used in
agriculture reaches the food we consumed, most of the rest is
lost in inefficient steps along the phosphorus cycle (Cordell et
al, 2011) (Figure 4). Globally, this lost phosphorus ends up in
water systems causing widespread pollution in lakes, rivers and
coastal areas, algal blooms, and dead zones in the oceans
(together with nitrogen).
Mined phosphate rock is principally used for agricultural
fertiliser (80%), the remainder being used for animal feed
additions (5%) and industrial applications (15%) including
detergents and metal treatment (Smit et al, 2009).
I can probably quibble over the numerical details, but the bulk of the
phosphorus (64-72% of global demand) that appears in the worlds water
systems seems to come from inefficient agricultural use. Looks like
you're right. It also appears that phosphorus resource depletion
might eventually become a problem.
wrote:
detergent use:
"Phosphorus in agriculture, Problems and solutions"
<http://www.greenpeace.to/greenpeace/wp-content/uploads/2012/06/tirado-and-allsopp-2012-phosphorus-in-agriculture-technical-report-02-2012.pdf>
A few quotes:
Agriculture is by far the main user of mined phosphorus globally,
accounting for between 80-90% of the total world demand (Childers
et al, 2011). However, only about 20% of the phosphorus used in
agriculture reaches the food we consumed, most of the rest is
lost in inefficient steps along the phosphorus cycle (Cordell et
al, 2011) (Figure 4). Globally, this lost phosphorus ends up in
water systems causing widespread pollution in lakes, rivers and
coastal areas, algal blooms, and dead zones in the oceans
(together with nitrogen).
Mined phosphate rock is principally used for agricultural
fertiliser (80%), the remainder being used for animal feed
additions (5%) and industrial applications (15%) including
detergents and metal treatment (Smit et al, 2009).
I can probably quibble over the numerical details, but the bulk of the
phosphorus (64-72% of global demand) that appears in the worlds water
systems seems to come from inefficient agricultural use. Looks like
you're right. It also appears that phosphorus resource depletion
might eventually become a problem.
Jeff Liebermann
Jul 26, 2015, 6:11:35 PM7/26/15
to
because of the precipitatates. STPP is, or rather was, a standard
ingredient in dishwasher detergent.
>>Get some now, before it's banned.
>
>It already is in weenie states.
"Global Phosphate ban status Oct 2009"
<http://www.phosphatesfacts.org/pdfs/GlobalAutodishStatus.pdf>
Jeff Liebermann
Jul 26, 2015, 6:27:47 PM7/26/15
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On Sun, 26 Jul 2015 14:04:41 -0400, rickman <gnu...@gmail.com> wrote:
>The distinction between urban areas and agricultural areas is pointless.
> The rivers and lakes don't care where the pollution comes from. For
>example the Potomac river drains 14,700 square miles of which perhaps
>some 1000 to 2000 is urban.
Water consumption is not proportional to land area. I don't have any
>The distinction between urban areas and agricultural areas is pointless.
> The rivers and lakes don't care where the pollution comes from. For
>example the Potomac river drains 14,700 square miles of which perhaps
>some 1000 to 2000 is urban.
numbers, but I suspect urban areas with high populations have more
washing machines and dishwashers per square mile than rural
agricultural areas.
>I kayak the Potomac river and it is still not what many would call
>"clean". I can't say what the phosphate pollution level is, but it
>shows many signs of pollution nearly everywhere along the lower 100
>miles including excrement floating along. The James river is not any
>better. Once on a paddle my girl friend counted the condoms floating
>by. On both of these rivers and many others in the area, it is not
>recommended that you eat many of the fish.
The JRA director, Bill Street, emphasized that "agricultural"
runoff is now the "predominate source of pollution" in the river.
The 2013 "State of the James River" report:
<http://jrava.org/what-we-do/Publications/StateOfTheJames2013.pdf>
looks like there are plenty of problems that still need to be
addressed. Phosphorus pollution appears to be mostly under control at
75% of target value.
<http://www.phosphatesfacts.org/anti-lead.asp>
Looks like Washington DC used phosphates to sequester the lead left in
the water pipes in 2004. I couldn't find anything that indicated if
it worked.
krw
Jul 26, 2015, 6:44:09 PM7/26/15
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On Sun, 26 Jul 2015 15:11:38 -0700, Jeff Liebermann <je...@cruzio.com>
Sorry, but TSP works great in a dishwasher.
rickman
Jul 26, 2015, 9:00:59 PM7/26/15
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On 7/26/2015 6:27 PM, Jeff Liebermann wrote:
> On Sun, 26 Jul 2015 14:04:41 -0400, rickman <gnu...@gmail.com> wrote:
>
>> The distinction between urban areas and agricultural areas is pointless.
>> The rivers and lakes don't care where the pollution comes from. For
>> example the Potomac river drains 14,700 square miles of which perhaps
>> some 1000 to 2000 is urban.
>
> Water consumption is not proportional to land area. I don't have any
> numbers, but I suspect urban areas with high populations have more
> washing machines and dishwashers per square mile than rural
> agricultural areas.
Who gives a rat's rear about dishwashers? The point is that the land
> On Sun, 26 Jul 2015 14:04:41 -0400, rickman <gnu...@gmail.com> wrote:
>
>> The distinction between urban areas and agricultural areas is pointless.
>> The rivers and lakes don't care where the pollution comes from. For
>> example the Potomac river drains 14,700 square miles of which perhaps
>> some 1000 to 2000 is urban.
>
> Water consumption is not proportional to land area. I don't have any
> numbers, but I suspect urban areas with high populations have more
> washing machines and dishwashers per square mile than rural
> agricultural areas.
used for agriculture far outweighs the land in urban areas. But more
importantly, it all goes into the *same* river! The water flowing by DC
drains from the full 14,700 square miles, not just the area inside the
beltway.
>> I kayak the Potomac river and it is still not what many would call
>> "clean". I can't say what the phosphate pollution level is, but it
>> shows many signs of pollution nearly everywhere along the lower 100
>> miles including excrement floating along. The James river is not any
>> better. Once on a paddle my girl friend counted the condoms floating
>> by. On both of these rivers and many others in the area, it is not
>> recommended that you eat many of the fish.
>
> <http://www.phosphatesfacts.org/jamesriver.asp>
> The JRA director, Bill Street, emphasized that "agricultural"
> runoff is now the "predominate source of pollution" in the river.
> The 2013 "State of the James River" report:
> <http://jrava.org/what-we-do/Publications/StateOfTheJames2013.pdf>
> looks like there are plenty of problems that still need to be
> addressed. Phosphorus pollution appears to be mostly under control at
> 75% of target value.
results in the warnings about eating fish.
--
Rick
George Herold
Jul 27, 2015, 11:08:57 AM7/27/15
to
On Saturday, July 25, 2015 at 11:14:20 AM UTC-4, Joe Gwinn wrote:
> This is a follow-on to the "Reverse polarity, Scotty" thread of
> September 2013, where the issue was how to clean a circuit board of
> soldering flux residue well enough for a 50 Gigaohm node to work.
>
> This is a follow-on to the "Reverse polarity, Scotty" thread of
> September 2013, where the issue was how to clean a circuit board of
> soldering flux residue well enough for a 50 Gigaohm node to work.
>
> I recently read a book on soldering ("Solders and Soldering", Howard H
> Manko, 3rd edition, McGraw-Hill 1992), which has extensive treatment of
> removal of flux residue.
>
> In the Reverse-Polarity thread, use of Kester 44 cored solder was
> discussed, so the flux in question is based on rosin.
>
> For rosin residue, the book's recommendation (page 315) is first
> cleaning with a terpene solvent (to dissolve rosin and other organic
> residue) followed by a hot-water wash. This is called the
> "Semi-Aqueous Cleaning Process".
>
> On small scale, dunking in terpentine from the paint store, shaking
> off, and passage through a domestic dishwasher using for instance
> AlcoJet detergent, followed by a wax-dip conformal coat, would do the
> job.
>
> Joe Gwinn
Hi Joe, Can I ask what the maximum voltage is?
> Manko, 3rd edition, McGraw-Hill 1992), which has extensive treatment of
> removal of flux residue.
>
> In the Reverse-Polarity thread, use of Kester 44 cored solder was
> discussed, so the flux in question is based on rosin.
>
> For rosin residue, the book's recommendation (page 315) is first
> cleaning with a terpene solvent (to dissolve rosin and other organic
> residue) followed by a hot-water wash. This is called the
> "Semi-Aqueous Cleaning Process".
>
> On small scale, dunking in terpentine from the paint store, shaking
> off, and passage through a domestic dishwasher using for instance
> AlcoJet detergent, followed by a wax-dip conformal coat, would do the
> job.
>
> Joe Gwinn
I don't know much about high impedance circuits,
but from previous threads I get the idea that it's a non-linear
resistance. What works at 1- 10 Volts may fail at 100 - 1kV.
(1 G ohm is the biggest R I've used to date.)
George H.
John Larkin
Jul 27, 2015, 2:02:10 PM7/27/15
to
On Sun, 26 Jul 2015 13:04:23 -0400, Phil Hobbs
space, and the process machines are on the other side, in a separate
space. I'm not sure which side needs to be cleaner, but they are
certainly different.
Things like this, built into a wall.
http://tinyurl.com/np4k6yz
--
John Larkin Highland Technology, Inc
picosecond timing precision measurement
<ho...@electrooptical.net> wrote:
>On 7/26/2015 12:58 PM, John Larkin wrote:
>> On Sun, 26 Jul 2015 10:49:52 -0400, Phil Hobbs
>> <ho...@electrooptical.net> wrote:
>>
>>> On 7/25/2015 9:55 PM, DecadentLinuxUserNumeroUno wrote:
>>>> On Sat, 25 Jul 2015 21:16:04 -0400, Joe Gwinn <joeg...@comcast.net>
>>>> Gave us:
>>>>
>>>>> Yeah, I remember that test. But leakage through residue and dirt on
>>>>> circuit boards is a common theme in the electrometer crowd.
>>>>
>>>> mere "coffee breath" can cause a failure mode.
>>>>
>>>
>>> That's more of a problem in semiconductor lithography.
>>> Chemically-amplified resist is very sensitive to amines, which prevent
>>> it from developing. (My stuff was all 248-nm, not the modern stuff.)
>>>
>>
>> Wafers tend to be transported in big sealed plastic casettes these
>> days, and plugged into process machines. I don't see why anybody needs
>> clean rooms any more.
>>
>>
>Belt and braces. You have to open the mini-environments at some stage,
>and having them in a Class 1 clean room helps a lot.
>
I've seen a wall where the people carrying the casettes are in one
>On 7/26/2015 12:58 PM, John Larkin wrote:
>> On Sun, 26 Jul 2015 10:49:52 -0400, Phil Hobbs
>> <ho...@electrooptical.net> wrote:
>>
>>> On 7/25/2015 9:55 PM, DecadentLinuxUserNumeroUno wrote:
>>>> On Sat, 25 Jul 2015 21:16:04 -0400, Joe Gwinn <joeg...@comcast.net>
>>>> Gave us:
>>>>
>>>>> Yeah, I remember that test. But leakage through residue and dirt on
>>>>> circuit boards is a common theme in the electrometer crowd.
>>>>
>>>> mere "coffee breath" can cause a failure mode.
>>>>
>>>
>>> That's more of a problem in semiconductor lithography.
>>> Chemically-amplified resist is very sensitive to amines, which prevent
>>> it from developing. (My stuff was all 248-nm, not the modern stuff.)
>>>
>>
>> Wafers tend to be transported in big sealed plastic casettes these
>> days, and plugged into process machines. I don't see why anybody needs
>> clean rooms any more.
>>
>>
>Belt and braces. You have to open the mini-environments at some stage,
>and having them in a Class 1 clean room helps a lot.
>
space, and the process machines are on the other side, in a separate
space. I'm not sure which side needs to be cleaner, but they are
certainly different.
Things like this, built into a wall.
http://tinyurl.com/np4k6yz
--
John Larkin Highland Technology, Inc
Phil Hobbs
Jul 27, 2015, 2:10:38 PM7/27/15
to
is called the "tool core' or just 'core'.
Back in 1991-92, I spent a certain number of hours ripping apart wafer
steppers in IBM East Fishkill to retrofit a better alignment system.
They were Perkin-Elmer Censors, and we managed to improve the overlay to
the point that they could use G-line litho for another process
generation, IBM ATX-4 ECL, before switching over to I-line (365 nm). It
was applied to 35 tools, and saved the company over a hundred million
bucks in equipment. (My colleague and I got a nice pat on the head.)
Joe Gwinn
Jul 28, 2015, 9:35:35 AM7/28/15
to
In article <240d955e-99fa-4680...@googlegroups.com>,
They are talking maybe ten or twenty volts.
While 100 KV also needs clean, it needs far more.
Joe Gwinn
While 100 KV also needs clean, it needs far more.
Joe Gwinn
DecadentLinuxUserNumeroUno
Jul 28, 2015, 9:40:54 AM7/28/15
to
On Tue, 28 Jul 2015 09:35:28 -0400, Joe Gwinn <joeg...@comcast.net>
Gave us:
100kV (small k), not only needs to be very clean (and baked free of
water), but it needs to be immediately encapsulated after that.
And the actual HV area should have no solder mask. Bare board.
Gave us:
water), but it needs to be immediately encapsulated after that.
And the actual HV area should have no solder mask. Bare board.
sean....@gmail.com
Jul 28, 2015, 12:14:29 PM7/28/15
to
Solvent reflux cleaning.
Joe Gwinn
Jul 28, 2015, 10:22:18 PM7/28/15
to
In article <d2bac6aa-fa22-4eb6...@googlegroups.com>,
<sean....@gmail.com> wrote:
> Solvent reflux cleaning.
More commonly known as a vapor degreaser.
It will take the rosin off, but what about the ionic crud? Need hot
water for that.
Joe Gwinn
<sean....@gmail.com> wrote:
> Solvent reflux cleaning.
More commonly known as a vapor degreaser.
It will take the rosin off, but what about the ionic crud? Need hot
water for that.
Joe Gwinn
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