Soldering surface mount components

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Daniel Kelly (AKA Jack)

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Jun 8, 2004, 4:31:28 PM6/8/04
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Hi,

I am planning a job where I need to manually solder surface mount ICs. Some
of these ICs have pins that are only 0.5mm apart! I'm worried that this
will be impossible to solder manually.

I've looked on the web - people tell me it is possible to solder SMDs but
I'm worried their talking about older SMDs with pin-to-pin distances of more
like 1mm.

I'm a relatively skilled soldering iron user.

Is it possible to manually solder ICs with pins only 0.5mm apart?

Thanks,
Jack


Charles Schuler

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Jun 8, 2004, 4:36:33 PM6/8/04
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"Daniel Kelly (AKA Jack)" <d.kell...@NOSPAM.ucl.ac.uk> wrote in message
news:ca57k1$1mja$1...@uns-a.ucl.ac.uk...

1/ Magnification
2/ Liquid flux and solder paste
3/ Hot air soldering device
4/ Practice and patience


Mariano

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Jun 8, 2004, 5:15:07 PM6/8/04
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"Charles Schuler" <charle...@comcast.net> wrote in message
news:PPWdnXrQkMH...@comcast.com...

> 1/ Magnification
> 2/ Liquid flux and solder paste

How do you apply the solder paste manually to the IC pins or pads ? I've
tried and the paste does not stick anywhere (before soldering). I even tried
with a syringe and ended up clogging the needle.

IMO this is the most critical part in SMD. It doesn't matter if your
placement is poor, since the solder will try to align the components with
the pads (when soldering). But you need to apply an even coat (and right
quantity) of paste to each pad. This is were I fail.

Ian Stirling

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Jun 8, 2004, 5:36:25 PM6/8/04
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In sci.electronics.design "Daniel Kelly \(AKA Jack\)" <d.kell...@nospam.ucl.ac.uk> wrote:
> Hi,
>
> I am planning a job where I need to manually solder surface mount ICs. Some
> of these ICs have pins that are only 0.5mm apart! I'm worried that this
> will be impossible to solder manually.

To add to this, is it possible to buy smaller diameter than normal solder?
I've found I can make my own, with a drawplate, but it is a tedious process.
I ahven't found anywhere that stocks under .5mm multicore.


Repzak

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Jun 8, 2004, 5:49:46 PM6/8/04
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> Is it possible to manually solder ICs with pins only 0.5mm apart?

Hey

Yearh.. i did it last week with a Tusb6250, on a home etched pcb...

u just used some quite thin solder and a lot of flux....

i thing my tip on the solder iron is 0,5 times 1mm ... but as long as there
is a lot of flux and you dosent use much solder i runs nice... and maybe use
"solder remover litze" with added flux to remove some of the solder there is
to much...


normally i just put litle solder on the solderiron tip and flux on the IC
legs, and then the flux will attrack the solder to the legs...


you could find some old computer stuff and remove some of the ic's with hot
air and use then as test, before using an expensive ic

Kasper


Mjolinor

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Jun 8, 2004, 5:50:37 PM6/8/04
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"Ian Stirling" <ro...@mauve.demon.co.uk> wrote in message
news:40c63159$0$551$ed26...@ptn-nntp-reader02.plus.net...
I just flatten it with pliers then cut it lengthways.


Mark (UK)

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Jun 8, 2004, 6:30:33 PM6/8/04
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Hi!

How I do it, is once the chip is removed, and you've got the bare pads,
I then use a regular iron set to a low temp, 275-300, to go over the
pads with fresh LMP solder and lots of flux, that tinns them up,the flux
helps stop them joining together, and leaves solder on each pad to help
solder the new IC legs to. Then use a hot air pencil to finally solder
the chip in place.

Yours, Mark.

John Larkin

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Jun 8, 2004, 6:35:27 PM6/8/04
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On Tue, 8 Jun 2004 17:15:07 -0400, "Mariano" <mfil...@uol.com.ar>
wrote:

>
>"Charles Schuler" <charle...@comcast.net> wrote in message
>news:PPWdnXrQkMH...@comcast.com...
>
>> 1/ Magnification
>> 2/ Liquid flux and solder paste
>
>How do you apply the solder paste manually to the IC pins or pads ? I've
>tried and the paste does not stick anywhere (before soldering). I even tried
>with a syringe and ended up clogging the needle.
>

Paste isn't necessary. Flux the pins (liquid, maybe diluted RMA rosin
flux) and apply a small glob of solder to the tip of the iron. Run the
tip down the pins, at the pin/pad junctions; solder will magically
wick off the tip onto the pins. There are special "hoof" tips with a
beveled flat that holds a nice little pool of solder to make this work
better.

Tack two corner pins first, then just run down the line. Works great.

John


Impmon

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Jun 8, 2004, 6:43:36 PM6/8/04
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On Tue, 8 Jun 2004 21:31:28 +0100, "Daniel Kelly \(AKA Jack\)"
<d.kell...@NOSPAM.ucl.ac.uk> wrote:

>Is it possible to manually solder ICs with pins only 0.5mm apart?

Yes it can be done, just use fine point, magnifying glass, and use
little solder.

It'd be easier to leave such tiny work to machines. Why do you need
to solder them manually?
--
To reply, replace digi.mon with tds.net

Chuck Olson

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Jun 8, 2004, 9:57:41 PM6/8/04
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"Daniel Kelly (AKA Jack)" <d.kell...@NOSPAM.ucl.ac.uk> wrote in message
news:ca57k1$1mja$1...@uns-a.ucl.ac.uk...
As mentioned, you need magnification. The first thing you should invest in
is a binocular microscope with variable power from 7 to 30 diameters and a
socket for a spotlight. If you can see it, you can do it. You should be
able to find a used one for about $200, (try Ebay) (and another $25 for the
spotlight) and it will last your whole life. You will be astounded at what
you can see with that microscope - - from examining today's almost invisible
electronic components to removing slivers and hangnails, and learning about
tiny creatures. Nobody should be without one.

The next thing you need is a soldering iron that allows your fingers to get
within about 1.25" of where the soldering is happening so that you have as
good control of the soldering tip as you have of the tip of a pencil when
you write. I find the Metcal stuff works very well, and older used systems
are available for under $100 on Ebay. Finally, you should be able to find
some 0.020" diameter solder (try Ebay or a big electronics flea market).

I made a surface-mount component clamp for my microscope consisting of a
strip of springy phosphor-bronze or beryllium-copper between two standoffs
about 3 inches apart and a piece of #12 wire soldered at the middle of the
strip to form a "T" so it pokes almost into the field of view of the
microscope, and finally a piece of #20 solid wire soldered at the end of the
#12 arm and bent down so the tip of the wire presses on the component you
want to solder right in the middle of the field of view. Just pull up on
the spring-supported #12 arm when you want to move the assembly or lift it
up onto another component.

Good luck,

Chuck


Daniel Kelly (AKA Jack)

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Jun 9, 2004, 6:52:21 AM6/9/04
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Hi,

> It'd be easier to leave such tiny work to machines. Why do you need
> to solder them manually?

I'm building a one-off design for a psychology PhD experiment. I do have
access to University College London's Electrical Engineering department but
I doubt they have robots for building surface mount systems.

Oh, and I have looked long and hard for 'normal' sized chips but they just
don't exist for the sort of application I need.

Thanks,
Jack

"Impmon" <imp...@digi.mon> wrote in message
news:u6gcc0594a15b7ii0...@4ax.com...

Daniel Kelly (AKA Jack)

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Jun 9, 2004, 6:52:41 AM6/9/04
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Excellent, thanks so much for all the help, everyone.

Jack


"Chuck Olson" <chucko...@REMOVETHIScomcast.net> wrote in message
news:p8uxc.5829$0y.3064@attbi_s03...

Tim Auton

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Jun 9, 2004, 11:03:02 AM6/9/04
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"Daniel Kelly \(AKA Jack\)" <d.kell...@NOSPAM.ucl.ac.uk> wrote:
>
>> It'd be easier to leave such tiny work to machines. Why do you need
>> to solder them manually?
>
>I'm building a one-off design for a psychology PhD experiment. I do have
>access to University College London's Electrical Engineering department but
>I doubt they have robots for building surface mount systems.

They will have technicians, lecturers and students who should know
what to do though. Ask nicely and someone might give you a
demonstration and show you the tools they have available.


Tim
--
Love is a travelator.

Product developer

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Jun 9, 2004, 11:06:37 AM6/9/04
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"Daniel Kelly \(AKA Jack\)" <d.kell...@NOSPAM.ucl.ac.uk> wrote in message news:<ca57k1$1mja$1...@uns-a.ucl.ac.uk>...


Antex low watt iron with fine tip. Use a flux pen to paint flux onto
pads. Using tweezers hold the I.C. in place and tack the corner pins.
Apply just enough solder to iron tip to wet it and flick off excess.
Apply the tip very briefly to the pin end and pad and the solder will
wick into and between the pin and pad. When removing a chip without
heat simply take a sharp Xacto blade and carefully apply pressure to
the blade onto the pins as near to the chip body as possible. This
will sever the pins from the chip body making them easier for removal
without lifting a pad. Be careful to not exceed the pin / chip body
with the knife or you will risk opening a trace. I have been doing
this for years and have lost a trace or pad in over twenty years.

Daniel Kelly (AKA Jack)

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Jun 9, 2004, 11:52:14 AM6/9/04
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Yes, good plan.

Jack


"Tim Auton" <tim.auton@uton.[groupSexWithoutTheY]> wrote in message
news:8c9ec0pugtdofn6mc...@4ax.com...

Gordon Youd

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Jun 9, 2004, 12:59:55 PM6/9/04
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I have a VHS video demonstrating METCAL Soldering Systems.

They make SMT rework by hand look so simple, like John Larkin said "tack the
ends and run down the line".

Try CPC Ltd for a copy of the video, it's free.

If you cannot get a copy I can copy mine for you.

The site for Metcal is www.metcal.com, I could not find the video there
but electronic wholesalers have it.

Regards, Gordon.

Remove the Z from my address to reply.

----------------------------------------------------------------------------
-----------
"Daniel Kelly (AKA Jack)" <d.kell...@NOSPAM.ucl.ac.uk> wrote in message
news:ca57k1$1mja$1...@uns-a.ucl.ac.uk...

Rene Tschaggelar

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Jun 9, 2004, 4:43:25 PM6/9/04
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Mariano wrote:

> "Charles Schuler" <charle...@comcast.net> wrote in message
> news:PPWdnXrQkMH...@comcast.com...
>
>
>>1/ Magnification
>>2/ Liquid flux and solder paste
>
>
> How do you apply the solder paste manually to the IC pins or pads ? I've
> tried and the paste does not stick anywhere (before soldering). I even tried
> with a syringe and ended up clogging the needle.

I have Flux inside a syringe with a 1mm needle. Before application i
heat the syringe and the flux with the heatgun to 80 degC or so.

The solder past also comes in a syringe that needs to be heated before
use. I prefer the 1mm tin wire though. Tin paste is a mess.

Rene
--
Ing.Buero R.Tschaggelar - http://www.ibrtses.com
& commercial newsgroups - http://www.talkto.net

Rene Tschaggelar

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Jun 9, 2004, 4:51:14 PM6/9/04
to

Yes. Sure.

For magnification I recommend strong reading glasses. I use 4 dioptries.
That let me have it as close as 15cm from my eyes.

Then I use fluxpaste from a syringe, heated with the heatgun to make it
more liquid.

And medium tip iron plus 1 mm or 0.8mm tim wire.

First come the fixng phase where two diagonal corner pins are soldered
down. It doesn't matter whether the adjacent pins are soldered too.

Don't even try to solder a single pins. A few of them at one is ok. The
flux separates the tin on the pins.
Oh, yes, having a soldermask helps.

Mariano

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Jun 9, 2004, 6:39:37 PM6/9/04
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Can anybody point me to any flux and paste product in the US ? I checked
Newark products and they are quite expensive. And since I have no experience
with flux/paste, I don't want to screw up buying something useless.

Thanks.
Mariano


"Rene Tschaggelar" <no...@none.net> wrote in message
news:40c776b4$0$21346$5402...@news.sunrise.ch...

Paul Guy

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Jun 9, 2004, 8:12:35 PM6/9/04
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The pads MUST NOT have any applied solder on them. If they do,
remove it all with solderwick. (the bumps from the solder will not
allow the chip to lie flat.)
Align the IC, solder one corner pin to hold it down. Solder the
opposite corner down. Don't worry if the solder joins several pins.
Make absolutely sure it's aligned properly, and all the pins are
resting on the pads. Now apply enough solder that all the pins are
covered, even if they are all shorted together.
Here's the neat part: Take some "solderwick" (the braided stuff you
use for removing solder) and remove all the solder! It doesn't really
take it all off, it leaves the required amount underneath the "feet"
of the pins. If you look in a microscope, you'll find that you have
almost perfectly soldered pins. There will be trouble if the pins
didn't all touch the pads prior to soldering. Chips intended for
surface mount must have good co-planarity, so be very gentle handling
them. If you bend the leads for than a few thousands of an inch, you
can expect trouble.
If you have a good touch with an iron, and are using good liquid
flux (RMA type, you must remove the residual flux afterward using a
solvent like isopropyl alcohol), you can zoom thin solder along the
pins, and it will not short them out. I believe it's absolutely
necessary to use the proper liquid flux in order to pull this off, and
it does need a bit of practice. You'll need the solderwick to remove
shorted pins. I figure if you're using solderwick anyhow, then do the
first method and not lose any sleep over it.
I have successfully soldered QFP80's this way, the most difficult
part is the alignment to the pads.
This is not a fast way to solder, but it doesn't need any fancy
equipment.
To show how crude you can get, instead of using our hot air reflow
stations (several thousand $ each), I demonstrated soldering a QFP80
using an old crappy soldering GUN, along with the solderwick removal.
The final results were just as good, under close inspection with a
microscope, and they easily met the IPC/EIA J-STD-001C soldering
standards. (Don't do this with a good chip! The soldering guns can
damage chips because of electrostatic discharge (ESD) from the
capacitive coupling to the power line.)

-Paul
..............................................................
Paul
Somewhere in the Nova Scotia fog
ANTISPAM - Please remove the m's in my email address

John Popelish

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Jun 9, 2004, 8:34:05 PM6/9/04
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Mariano wrote:
>
> Can anybody point me to any flux and paste product in the US ? I checked
> Newark products and they are quite expensive. And since I have no experience
> with flux/paste, I don't want to screw up buying something useless.
>
Go to Newark In One and search the key words [flux pen]. They sell
several different fluxes in a felt tip pen dispensers.

--
John Popelish

John Larkin

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Jun 9, 2004, 8:40:06 PM6/9/04
to
On Wed, 09 Jun 2004 21:12:35 -0300, Paul Guy
<mpaul...@meastlinkm.ca> wrote:

>On Tue, 8 Jun 2004 21:31:28 +0100, "Daniel Kelly \(AKA Jack\)"
><d.kell...@NOSPAM.ucl.ac.uk> wrote:
>
>>Hi,
>>
>>I am planning a job where I need to manually solder surface mount ICs. Some
>>of these ICs have pins that are only 0.5mm apart! I'm worried that this
>>will be impossible to solder manually.
>>
>>I've looked on the web - people tell me it is possible to solder SMDs but
>>I'm worried their talking about older SMDs with pin-to-pin distances of more
>>like 1mm.
>>
>>I'm a relatively skilled soldering iron user.
>>
>>Is it possible to manually solder ICs with pins only 0.5mm apart?
>>
>>Thanks,
>>Jack
>>
> The pads MUST NOT have any applied solder on them. If they do,
>remove it all with solderwick. (the bumps from the solder will not
>allow the chip to lie flat.)

We sent out some BGA chips (560 or so balls) to be soldered. The guy
who did it for us applied no solder, just used the solder coating that
came on the board. He said you have to apply the flux with a bare
finger, nothing else will do. He did xray every joint, and all the
boards worked fine.

John


Andre

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Jun 10, 2004, 4:36:12 AM6/10/04
to
John Larkin <jjla...@highSNIPlandTHIStechPLEASEnology.com> wrote in message news:<98bfc09udp1ivrkjs...@4ax.com>...

Thats pretty neat :) I have some dead cameras here with fried BGA
controller chips.

BGA chips are a total pain to solder- you need a proper infra-red
reflow unit and X-ray scanner which your average hobbyist (except
maybe Sam G and/or Chip Shultz) won't have access to.

:)

-A


-A

>
> John

Daniel Kelly (AKA Jack)

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Jun 10, 2004, 6:46:03 AM6/10/04
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Dear Gordon,

Many many thanks for your reply.

I've had a search for the video and can't find it anywhere.

Do you know for sure where I could get hold of it in the UK?

If not, I would be most indepted if I could get a copy from you. Could you
e-mail me a DivX or something?

Many many thanks,
Jack

"Gordon Youd" <gor...@Zgyoud.demon.co.uk> wrote in message
news:ca7fq2$1on$1$8300...@news.demon.co.uk...

Daniel Kelly (AKA Jack)

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Jun 10, 2004, 6:56:38 AM6/10/04
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Dear Gordon,

Actually, don't worry - I've just phoned up Eagle, METCAL's UK supplier, and
they're sending a CD-ROM to me in the post right now! How cool is that?!?
Thanks so much!

Jack

"Daniel Kelly (AKA Jack)" <d.kell...@NOSPAM.ucl.ac.uk> wrote in message

news:ca9e2a$305q$1...@uns-a.ucl.ac.uk...

Cyclonus

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Jun 10, 2004, 5:22:27 PM6/10/04
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On Thu, 10 Jun 2004 11:56:38 +0100, "Daniel Kelly \(AKA Jack\)"
<d.kell...@NOSPAM.ucl.ac.uk> wrote:

>Dear Gordon,
>
>Actually, don't worry - I've just phoned up Eagle, METCAL's UK supplier, and
>they're sending a CD-ROM to me in the post right now! How cool is that?!?
>Thanks so much!
>
>Jack
>

Wow, thats really great, I suppose you wouldnt know whom I could
contact in Canada to get a copy of that CD??

Maurice

Gordon Youd

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Jun 10, 2004, 6:06:41 PM6/10/04
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Maurice, Try their site www.metcal.com

CANADA

EMX
(Manufacturers Rep)
227 Idema Road

Marhkam, ON, L3R 1B1, CANADA

Phone: 905-475-8000
Fax: 905-475-2300
Email: sa...@emx.ca

--------------------------------------------------------------------------

EMX
(Manufacturers Rep)
5950 Frued #23

Montreal, PQ, H4S 1T1, CANADA

Phone: 514-484-6565
Fax: 514-482-2221
Email: sa...@emx.ca

--------------------------------------------------------------------------

Adtool
(Distributor)
10 Ronald Drive

Montreal, Quebec, H4X 1M8, CANADA

Phone: 514-482-2548
Fax:
Email:

--------------------------------------------------------------------------

Adtool
(Distributor)
141 6200 MacKay Ave.

Burnaby, B. C., V5H 4M9, CANADA

Phone: 604-618-2924
Fax:
Email:

--------------------------------------------------------------------------


Regards, Gordon.
----------------------------------------------------------------

"Cyclonus" <xycycl...@NOSPAMhotmail.com> wrote in message
news:s6khc0d3rolbebe4j...@4ax.com...

Michael Schwingen

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Jun 11, 2004, 10:10:52 AM6/11/04
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In article <40c77888$0$21346$5402...@news.sunrise.ch>,

Rene Tschaggelar <no...@none.net> wrote:
>
>Then I use fluxpaste from a syringe, heated with the heatgun to make it
>more liquid.

Metcal has a nice Fluxpen ("FP-1") with a brush-like tip and
squeeze-dispenser that works very well when filled with liquid flux - I use
no-clean flux, which is non-sticky, but it should also work with rosin flux.

cu
Michael

Cyclonus

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Jun 11, 2004, 10:29:16 AM6/11/04
to
On Thu, 10 Jun 2004 23:06:41 +0100, "Gordon Youd"
<gor...@Zgyoud.demon.co.uk> wrote:
Thanks!, I sent a request off the the local Canadian office.

Maurice

Hans Summers

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Jun 14, 2004, 8:42:06 AM6/14/04
to

You people are all talking about flux, solder flows, PCB's, but you've got
it all wrong!

You should take a look at my page
http://www.hanssummers.com/electronics/equipment/spectrumanalyser2/index.htm
. About 2/3 the way down you'll see a closeup photo on the left hand side,
showing a 24-pin TSSOP packaged ADC chip. The pin spacing is 0.65mm (Ok, so
not quite your 0.5mm). You can click the picture for a larger version.

I did this with:

NO magnifying glass
NO special lighting
NO hot air etc
NO special soldering iron, just my old 18W Antex CS
NO special bit, just my Antex 1mm bit type 1106
NO special solder or flux, just ordinary 22swg 60/40 multicore fluxed solder
NO pre-etched PCB, just a piece of PCB stock I cut some pads in with a cheap
plastic craft knife
NO fancy rigs to hold the work, just loose on the bench, with the IC glued
to the board

And it worked first time.

I've soldered other SMD IC's too, but this one was the most extreme. You'll
also find less tiny spacing'ed SMD IC's soldered on these pages of my site:

http://www.hanssummers.com/radio/polyphase/index.htm
http://www.hanssummers.com/radio/ozon/index.htm
http://www.hanssummers.com/computers/newz80/intro.htm
http://www.hanssummers.com/electronics/equipment/riskometer/index.htm

Anything's possible ;-)

Hans
http://www.HansSummers.com


Chuck Olson

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Jun 14, 2004, 12:41:47 PM6/14/04
to

"Hans Summers" <hans.s...@tudor.com> wrote in message
news:2j5kp9F...@uni-berlin.de...
You must be very near-sighted.


Spehro Pefhany

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Jun 14, 2004, 1:12:00 PM6/14/04
to
On Mon, 14 Jun 2004 16:41:47 GMT, the renowned "Chuck Olson"
<chucko...@REMOVETHIScomcast.net> wrote:

>
>"Hans Summers" <hans.s...@tudor.com> wrote in message
>news:2j5kp9F...@uni-berlin.de...
>>
>> You people are all talking about flux, solder flows, PCB's, but you've got
>> it all wrong!
>>
>> You should take a look at my page
>>
>http://www.hanssummers.com/electronics/equipment/spectrumanalyser2/index.htm


That old Heathkit signal generator is a hoot. Tubes (err, "valves"),
right?


Best regards,
Spehro Pefhany
--
"it's the network..." "The Journey is the reward"
sp...@interlog.com Info for manufacturers: http://www.trexon.com
Embedded software/hardware/analog Info for designers: http://www.speff.com

Mariano

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Jun 14, 2004, 1:46:10 PM6/14/04
to

So how did you do it then? you forgot to tell us how

- solder tip size?
- solder type?
- ...


"Hans Summers" <hans.s...@tudor.com> wrote in message
news:2j5kp9F...@uni-berlin.de...
>

Hans Summers

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Jun 15, 2004, 5:27:07 AM6/15/04
to

"Mariano" <mfilippaR...@uol.com.ar> wrote in message
news:Crlzc.90$gs....@news.itd.umich.edu...

>
> So how did you do it then? you forgot to tell us how

No, I did tell you (at least, I did tell you those things)... here's my
original relevant sections pasted in again:
>
> - solder tip size?

> > NO special soldering iron, just my old 18W Antex CS
> > NO special bit, just my Antex 1mm bit type 1106

> - solder type?

> > NO special solder or flux, just ordinary 22swg 60/40 multicore fluxed
solder

As for process:

This TSSOP had 24 pins (unfortunately the catalogue had claimed in was DIL,
but in reality it was SMD. Pity I didn't read the datasheet carefully enough
and match up the part numbers).

So anyway, I carved two columns of small pads on the surface of the unetched
PCB using a knife (one of those ubiquitous dirt cheap orange "craft"
knives). 2 columns of 6 on each side of the chip, makes 24. I couldn't do 12
per side because they would have been too narrow for me to cut with that
knife. I left a space in between the pairs of columns either side, for the
IC.

The IC was glued in position. Now alternate pins on the TSSOP are bent
upwards. So considering the left hand side, pins 1, 3, 5, 7, 9, 11 continue
resting on the newly carved first column of 5 pads. Pins 2, 4, 6, 8, 10, 12
are bent upwards away from the board. Then I took ordinary multi-core wire,
and took single copper strands from it. These pins 2, 4, 6 etc were
connected to the outer column of 6 pads using these thin copper strands.
Bending alternate pins of the IC in opposite directions makes it possible to
solder to the pins even with this 1mm iron bit.

Have another look at the picture,
http://www.hanssummers.com/electronics/equipment/spectrumanalyser2/index.htm
and you will be able to see some of the things I'm talking about (the
columns of carved pads etc).

Hans
http://www.HansSummers.com


Hans Summers

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Jun 15, 2004, 5:27:49 AM6/15/04
to
> >
> You must be very near-sighted.
>
No, not at all. You should probably be worried about my sanity though ;-)

Hans
http://www.HansSummers.com


Hans Summers

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Jun 15, 2004, 5:30:59 AM6/15/04
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"Spehro Pefhany" <spef...@interlogDOTyou.knowwhat> wrote in message
news:idnrc0prkf0k6co7b...@4ax.com...

> On Mon, 14 Jun 2004 16:41:47 GMT, the renowned "Chuck Olson"
> <chucko...@REMOVETHIScomcast.net> wrote:
>
> >
> >"Hans Summers" <hans.s...@tudor.com> wrote in message
> >news:2j5kp9F...@uni-berlin.de...
> >>
> >> You people are all talking about flux, solder flows, PCB's, but you've
got
> >> it all wrong!
> >>
> >> You should take a look at my page
> >>
>
>http://www.hanssummers.com/electronics/equipment/spectrumanalyser2/index.ht
m
>
>
> That old Heathkit signal generator is a hoot. Tubes (err, "valves"),
> right?

Right, valves ;-) I forget the valve types. If I recall it contains only
two valves, but I might be remembering wrongly. You can find a large picture
of it here:
http://www.hanssummers.com/electronics/equipment/signalgenerator/sig.htm . I
did open it and take some photos of the insides, but I got the focus all
wrong and didn't bother to re-open it again. I've even got a copy of most of
the manual, sent to me by an Irish radio amateur who has the same generator.

Hans
http://www.HansSummers.com


Steven McGahey

unread,
Nov 30, 2004, 2:34:00 PM11/30/04
to
Hi all,

I've read this thread with a lot of interest, as I have a small bit of
surface-mount work to do, but no experience working with these tiny
components.

I would have thought that when working with these components, you would have
to use a different approach, and try to keep the component cool (as it'll
fry otherwise), but this thread seems to suggest otherwise.

Can someone straighten me out on this subject, as I have a feeling that
Nokia will want me to purchase a new phone circuit-board (~£70) if I ask
them to repair it, when it's only a minor soldering job that is required.

Thanks in advance,
- Steve

Roger Johansson

unread,
Nov 30, 2004, 3:05:49 PM11/30/04
to
"Steven McGahey" <steven.doesntn...@virgin.theISP.net (remove
the obvious bits)> wrote:

> I've read this thread with a lot of interest, as I have a small bit of
> surface-mount work to do, but no experience working with these tiny
> components.
>
> I would have thought that when working with these components, you would
> have to use a different approach, and try to keep the component cool
> (as it'll fry otherwise), but this thread seems to suggest otherwise.

Modern components are very seldom destroyed by heat.
Components are made to withstand soldering heat for 10 seconds, or so.

If you fail to make a good soldering joint in 5 seconds, wait for a few
minutes before you make a new try, to let the component cool down.

--
Roger J.

John Larkin

unread,
Nov 30, 2004, 3:21:48 PM11/30/04
to
On Tue, 30 Nov 2004 19:34:00 GMT, "Steven McGahey"

<steven.doesntn...@virgin.theISP.net (remove the obvious
bits)> wrote:

>Hi all,
>
>I've read this thread with a lot of interest, as I have a small bit of
>surface-mount work to do, but no experience working with these tiny
>components.
>
>I would have thought that when working with these components, you would have
>to use a different approach, and try to keep the component cool (as it'll
>fry otherwise), but this thread seems to suggest otherwise.
>
>Can someone straighten me out on this subject, as I have a feeling that
>Nokia will want me to purchase a new phone circuit-board (~£70) if I ask
>them to repair it, when it's only a minor soldering job that is required.
>
>Thanks in advance,
>- Steve
>


Surface-mount parts are designed to be soldered in a reflow oven,
where the entire loaded board gets heated above solder-melt
temperature for a minute or so. Most parts don't mind. I just solder
them by hand, and it pretty much always works.

I have seen some surfmount LEDs turn to putty when hand soldered. The
transparent plastics seem to be fragile.

John

Larry Brasfield

unread,
Dec 1, 2004, 12:41:40 AM12/1/04
to
"John Larkin" <jjla...@highSNIPlandTHIStechPLEASEnology.com>
wrote in message news:a7lpq05v0jvt6vqbg...@4ax.com...

> Surface-mount parts are designed to be soldered in a reflow oven,
> where the entire loaded board gets heated above solder-melt
> temperature for a minute or so. Most parts don't mind. I just solder
> them by hand, and it pretty much always works.

Hand soldering can be very hard on SMD ceramic capacitors.
The high temperature gradiant created by applying heat suddenly
at one end can fracture the ceramic. This can lead to excess noise
or a tendency to break down at a lower than rated voltage as
moisure gets into the crack(s). The insidious aspect of this kind
of damage is that it can show up in the field, quite some time
after the parts perform alright in initial testing.

At Siemens Ultrasound, we learned this the hard way, then had it
confirmed by at least one vendor's examination of abused parts.

...
> John

--
--Larry Brasfield
email: donotspam_la...@hotmail.com
Above views may belong only to me.


Clarence

unread,
Dec 1, 2004, 4:09:38 AM12/1/04
to

"Larry Brasfield" <donotspam_la...@hotmail.com> wrote in message
news:nQcrd.395$O54....@news.uswest.net...

> "John Larkin" <jjla...@highSNIPlandTHIStechPLEASEnology.com>
> wrote in message news:a7lpq05v0jvt6vqbg...@4ax.com...
> > Surface-mount parts are designed to be soldered in a reflow oven,
> > where the entire loaded board gets heated above solder-melt
> > temperature for a minute or so. Most parts don't mind. I just solder
> > them by hand, and it pretty much always works.
>
> Hand soldering can be very hard on SMD ceramic capacitors.
> The high temperature gradiant created by applying heat suddenly
> at one end can fracture the ceramic. This can lead to excess noise
> or a tendency to break down at a lower than rated voltage as
> moisure gets into the crack(s). The insidious aspect of this kind
> of damage is that it can show up in the field, quite some time
> after the parts perform alright in initial testing.
>
> At Siemens Ultrasound, we learned this the hard way, then had it
> confirmed by at least one vendor's examination of abused parts.
>
> --Larry Brasfield

Of course this may have actually happened, and Boy, you had some pretty lousy
assembly people. I've seen the pre-prod units used for test assembled and
soldered by hand and subjected to extensive testing. Never saw a solder
related failure of a component. We tested for very long periods on many
boards. Of course we also inspected the boards before applying power and
checking for damage. Rarely had to retouch a board after the first three.

Terry Given

unread,
Dec 1, 2004, 4:20:16 AM12/1/04
to
Larry Brasfield wrote:

This is a VERY good point. Reflow ovens have very well controlled
thermal profiles, slowly ramping temperature to a plateau, holding,
slowly ramping up to final tmep, holding etc. Mostly to avoid this
thermal shock related mechanical failure mechanism. High voltage
ceramics are especially prone to this - hand soldering them is a risky
process.

I once used 2 x 15nF 1000V smt X7R caps in series across an 80-800Vdc
supply for a smps application. During testing one smps failed
catastrophically (two others ran fine). Detailed examination of the
corpse showed a blast pattern radiating outward from one of the caps,
which had ruptured. The resulting mess sprayed directly across the legs
of one of the FETs, thereby toasting the unit. At the time it was
operating at a DC bus voltage of around 400V, so the cap was nowhere
near its rated voltage, more like 20%. One of the guys I worked with had
extensive experience in this area (hi-rel smps hybrids for
il/aerospace), and showed us what went wrong. We immediately replaced
the capacitors, carefully using a manual hot air station, to both
preheat and solder. The units operated continuously into a dead short at
800Vdc, no problems - there were other issues of course, it was a
pre-production protoype, but none of the explosive kind.

Cheers
Terry

John Larkin

unread,
Dec 1, 2004, 11:17:33 AM12/1/04
to
On Tue, 30 Nov 2004 21:41:40 -0800, "Larry Brasfield"
<donotspam_la...@hotmail.com> wrote:

>"John Larkin" <jjla...@highSNIPlandTHIStechPLEASEnology.com>
>wrote in message news:a7lpq05v0jvt6vqbg...@4ax.com...
>> Surface-mount parts are designed to be soldered in a reflow oven,
>> where the entire loaded board gets heated above solder-melt
>> temperature for a minute or so. Most parts don't mind. I just solder
>> them by hand, and it pretty much always works.
>
>Hand soldering can be very hard on SMD ceramic capacitors.
>The high temperature gradiant created by applying heat suddenly
>at one end can fracture the ceramic. This can lead to excess noise
>or a tendency to break down at a lower than rated voltage as
>moisure gets into the crack(s). The insidious aspect of this kind
>of damage is that it can show up in the field, quite some time
>after the parts perform alright in initial testing.
>
>At Siemens Ultrasound, we learned this the hard way, then had it
>confirmed by at least one vendor's examination of abused parts.
>

Maybe the parts are getting better, but I've never seen that happen,
and some of our boards have lots of parts on the bottom,
hand-soldered. I hand-solder all kinds of parts in the lab, and can't
recall ever damaging one, unless it wasn't on a PCB, like soldered
directly to a connector or on a copperclad breadboard, where it is
possible to apply some bending forces and rip off the end caps.

We have virtually zero returns from the field due to damaged passives.

John

Howard Long

unread,
Dec 1, 2004, 12:16:44 PM12/1/04
to
"Steven McGahey" <steven.doesntn...@virgin.theISP.net (remove
the obvious bits)> wrote in message
news:IW3rd.1515$ck3....@newsfe6-gui.ntli.net...

> Hi all,
>
> I've read this thread with a lot of interest, as I have a small bit of
> surface-mount work to do, but no experience working with these tiny
> components.
>
> I would have thought that when working with these components, you would
have > to use a different approach, and try to keep the component cool (as
it'll
> fry otherwise), but this thread seems to suggest otherwise.

FWIW, I use a standard temperature controlled iron with a small tip (I think
it cost about $50), with very thin solder, desolder braid.

I do everyting on a plain white tray with lips around the edge - there's
nothing worse than losing that last 3.3k resistor you had on the carpet...

I do have a small magnifying glass, but that's just to help me identify the
components that actually have markings - I don't use it for anything else.

For the chips with loads of pins at tiny spacing (including 0.5mm), I use a
really tiny piece of bluetak (a bit like plasticine or playdoh, but sticks
paper to walls) to fix the component into place, then I solder the
component. I don't worry too much about solder bridges over the leads for
now, but I am rather careful to use small amounts of solder, in case it
creeps under the chip.

Then I use the desolder braid to mop up the excess solder. After a visual
inspection, I do a continuity check of each of the leads to ensure there's
connection to the pcb as well as no shorts between adjacent leads of the
chip. A pain, and almost every time it shows nothing untoward.

Rework involving removal of chips takes a number of tricks, but primarily
remember that you're much more interested in maintaining the PCB in good
shape, at the expense of a trashed component.

Good luck. Howard.


Larry Brasfield

unread,
Dec 1, 2004, 12:55:52 PM12/1/04
to
"Clarence" <n...@No.com> wrote in message
news:mTfrd.36936$6q2....@newssvr14.news.prodigy.com...

> "Larry Brasfield" <donotspam_la...@hotmail.com> wrote in message
> news:nQcrd.395$O54....@news.uswest.net...
>> "John Larkin" <jjla...@highSNIPlandTHIStechPLEASEnology.com>
>> wrote in message news:a7lpq05v0jvt6vqbg...@4ax.com...
>> > Surface-mount parts are designed to be soldered in a reflow oven,
>> > where the entire loaded board gets heated above solder-melt
>> > temperature for a minute or so. Most parts don't mind. I just solder
>> > them by hand, and it pretty much always works.
>>
>> Hand soldering can be very hard on SMD ceramic capacitors.
>> The high temperature gradiant created by applying heat suddenly
>> at one end can fracture the ceramic. This can lead to excess noise
>> or a tendency to break down at a lower than rated voltage as
>> moisure gets into the crack(s). The insidious aspect of this kind
>> of damage is that it can show up in the field, quite some time
>> after the parts perform alright in initial testing.
>>
>> At Siemens Ultrasound, we learned this the hard way, then had it
>> confirmed by at least one vendor's examination of abused parts.
>>
>> --Larry Brasfield
>
> Of course this may have actually happened,

Yes, of course.

> and Boy, you had some pretty lousy assembly people.

They were quite skilled and competent, generally. If you knew
the circumstances under which the hand soldering occured, you
might not be so willing to denigrate them. (But who knows?)

> I've seen the pre-prod units used for test assembled and
> soldered by hand and subjected to extensive testing. Never saw a solder
> related failure of a component.

To see the excess noise phenomenon, you would have to be
looking at a circuit handling low level signals which would be
affected by random parametric shifts. To see the drop in
voltage withstand, you would have to be using parts at an
appreciable fraction of their rated voltage, or subject them
to conditions under which moisture would enter the cracks.
So the fact that you never saw that is not much reassurance.

> We tested for very long periods on many boards.

But what were you testing for? Did the environment
promote moisture ingression into the cracks? Was there
thermal cycling? I must say, your failure to see that
phenomenon is weak evidence against its reality.

> Of course we also inspected the boards before applying power and
> checking for damage. Rarely had to retouch a board after the first three.

The damage I mentioned is nearly impossible to see without
a microscope. Typically, the micro-cracks do not extend
clear thru the part, and they tend to be closed, being held
together by the unbroken material. I doubt your inspection
would have caught that damage.

The facts I have related regarding the failure mechansim,
and the strong disrecommendation against hand soldering
ceramic SMD capacitors, came to me directly from a well
known and reputable supplier of such parts. You, or other
"we got away with something, so it must be fine" kind of
folks can disregard it and often not pay the price. Those
who desire reliability will more likely heed it.

Terry Given

unread,
Dec 1, 2004, 2:08:32 PM12/1/04
to

its the rate-of-change of temperature thats the real killer. Larger caps
are worse, as the resulting dimensional changes are bigger.


>
>
>>I've seen the pre-prod units used for test assembled and
>>soldered by hand and subjected to extensive testing. Never saw a solder
>>related failure of a component.
>
>
> To see the excess noise phenomenon, you would have to be
> looking at a circuit handling low level signals which would be
> affected by random parametric shifts. To see the drop in
> voltage withstand, you would have to be using parts at an
> appreciable fraction of their rated voltage, or subject them
> to conditions under which moisture would enter the cracks.
> So the fact that you never saw that is not much reassurance.
>
>
>>We tested for very long periods on many boards.
>
>
> But what were you testing for? Did the environment
> promote moisture ingression into the cracks? Was there
> thermal cycling? I must say, your failure to see that
> phenomenon is weak evidence against its reality.
>

ROTFLMAO!

>
>>Of course we also inspected the boards before applying power and
>>checking for damage. Rarely had to retouch a board after the first three.
>
>
> The damage I mentioned is nearly impossible to see without
> a microscope. Typically, the micro-cracks do not extend
> clear thru the part, and they tend to be closed, being held
> together by the unbroken material. I doubt your inspection
> would have caught that damage.

doesnt everyone have a binocular microscope? how quaint.

>
> The facts I have related regarding the failure mechansim,
> and the strong disrecommendation against hand soldering
> ceramic SMD capacitors, came to me directly from a well
> known and reputable supplier of such parts. You, or other
> "we got away with something, so it must be fine" kind of
> folks can disregard it and often not pay the price. Those
> who desire reliability will more likely heed it.

There are also mechanical resonance related with the larger ceramic smt
parts (Marcon have poublished several papers on this effect).

Recently I have hand-soldered about 2000 0603 caps (prototypes). Perhaps
2-3 caps failed immediately; as its a prorotype I dont care about
medium-long term reliability, but no way would I give it to a customer :)

Cheers
Terry

Clarence

unread,
Dec 1, 2004, 3:21:18 PM12/1/04
to

"Terry Given" <my_...@ieee.org> wrote in message
news:QEord.20625$9A.3...@news.xtra.co.nz...
> > the circumstances under which the hand soldering occurred, you

> > might not be so willing to denigrate them. (But who knows?)
>
> its the rate-of-change of temperature that's the real killer. Larger caps

> are worse, as the resulting dimensional changes are bigger.
> >
> >>I've seen the pre-prod units used for test assembled and
> >>soldered by hand and subjected to extensive testing. Never saw a solder
> >>related failure of a component.
> >
> > To see the excess noise phenomenon, you would have to be
> > looking at a circuit handling low level signals which would be
> > affected by random parametric shifts. To see the drop in
> > voltage withstand, you would have to be using parts at an
> > appreciable fraction of their rated voltage, or subject them
> > to conditions under which moisture would enter the cracks.
> > So the fact that you never saw that is not much reassurance.
> >
> >>We tested for very long periods on many boards.
> >
> > But what were you testing for? Did the environment
> > promote moisture ingression into the cracks? Was there
> > thermal cycling? I must say, your failure to see that
> > phenomenon is weak evidence against its reality.
> >
> ROTFLMAO!

Not much moisture in a near vacuum!

> >
> >>Of course we also inspected the boards before applying power and
> >>checking for damage. Rarely had to retouch a board after the first three.
> >
> > The damage I mentioned is nearly impossible to see without
> > a microscope. Typically, the micro-cracks do not extend
> > clear thru the part, and they tend to be closed, being held
> > together by the unbroken material. I doubt your inspection
> > would have caught that damage.
>

> doesn't everyone have a binocular microscope? how quaint.
>
> >
> > The facts I have related regarding the failure mechanism,


> > and the strong disrecommendation against hand soldering
> > ceramic SMD capacitors, came to me directly from a well
> > known and reputable supplier of such parts. You, or other
> > "we got away with something, so it must be fine" kind of
> > folks can disregard it and often not pay the price. Those
> > who desire reliability will more likely heed it.

I'll take the 'disrecommendation' with a box of salt!

> There are also mechanical resonance related with the larger ceramic SMT
> parts (Marcon have published several papers on this effect).


>
> Recently I have hand-soldered about 2000 0603 caps (prototypes). Perhaps

> 2-3 caps failed immediately; as its a prototype I don't care about


> medium-long term reliability, but no way would I give it to a customer :)
>
> Cheers
> Terry

I am delighted to hear you wouldn't give your work to a customer. Many
prototypes are unsuited for the customer to see anyway due to the rework and
handling in engineering test. I NEVER ship a 'prototype' to anyone. That is
what a "first Article" is for!

As for the work I cited! These were weather Satellite boards, RF, motor
control, CPU, and digital communications, plus low level analog video, with
analog to digital conversion. There will only be 18 final units built, and
testing (with temperature cycling from -40 to + 80 Degrees C four times a day
at 5 degrees C per minute) was eight times a day, total time of a complete test
was 2,000 hours. MTTF predicted is 18 years. Also they must survive 50,000
Kilorads exposure.

Yes, Inspection under a microscope, 20 and 50 diameters magnification. Before
and after tests. Yes All boards were also tested on a shake table, they must
survive launch.

The Customer is NASA, they are very particular, and will launch the first of
these in 2006.

Shooting one's mouth off when someone tries to help causes a loss of
credibility!
Since your really an amateur, live with your poor workmanship and cry about it!


Jim Adney

unread,
Dec 1, 2004, 10:06:46 PM12/1/04
to
On Tue, 30 Nov 2004 19:34:00 GMT "Steven McGahey"
<steven.doesntn...@virgin.theISP.net (remove the obvious
bits)> wrote:

>I would have thought that when working with these components, you would have
>to use a different approach, and try to keep the component cool (as it'll
>fry otherwise), but this thread seems to suggest otherwise.

I was on the Vishay web site recently and came across a writeup they
have on hand soldering surface mount electrolytics. If you do any of
this I believe it's worth looking up. They are rather cautious and
suggest that if you spend more than 3 seconds on a junction that's too
long and you should start over with a new part.

Seems extreme to me, but they're the ones who are actually in a
position to know.

-
-----------------------------------------------
Jim Adney jad...@vwtype3.org
Madison, WI 53711 USA
-----------------------------------------------

Terry Given

unread,
Dec 2, 2004, 12:15:41 AM12/2/04
to
Hi Clarence,

Clarence wrote:

Hear Hear!

Reflow machines are best suited to soldering smt. If you have to do it
by hand, use hot air. A bloody great soldering is the worst way.

>
> As for the work I cited! These were weather Satellite boards, RF, motor
> control, CPU, and digital communications, plus low level analog video, with
> analog to digital conversion. There will only be 18 final units built, and
> testing (with temperature cycling from -40 to + 80 Degrees C four times a day
> at 5 degrees C per minute) was eight times a day, total time of a complete test
> was 2,000 hours. MTTF predicted is 18 years. Also they must survive 50,000
> Kilorads exposure.

ouch.

>
> Yes, Inspection under a microscope, 20 and 50 diameters magnification. Before
> and after tests. Yes All boards were also tested on a shake table, they must
> survive launch.
>
> The Customer is NASA, they are very particular, and will launch the first of
> these in 2006.
>
> Shooting one's mouth off when someone tries to help causes a loss of
> credibility!
> Since your really an amateur, live with your poor workmanship and cry about it!

What makes you think I'm an amateur? I just dont want to hire a tech
(labour laws become a real pain in the ass when you have staff).

Cheers
Terry

remove two items of clothing

unread,
Dec 2, 2004, 1:46:48 AM12/2/04
to
Roger, John, Howard and Jim,

Thanks for your response, guys - much appreciated.

I'll give this a go with the blutack (we had the same thing in Australia -
wonder what the UK equivalent is...) and desoldering braid.

I think I also need a smaller soldering iron tip - the last one was still
too big and bulky with a 1 or 2 mm point.

Cheers,
-Steve.

Clarence

unread,
Dec 2, 2004, 2:56:36 AM12/2/04
to

"Terry Given" <my_...@ieee.org> wrote in message
news:1yxrd.21491$9A.3...@news.xtra.co.nz...

> Hi Clarence,
> Clarence wrote:
> > "Terry Given" <my_...@ieee.org> wrote in message
> > news:QEord.20625$9A.3...@news.xtra.co.nz...
> >>Larry Brasfield wrote:
> >>>"Clarence" <n...@No.com> wrote in message
> >>> news:mTfrd.36936$6q2....@newssvr14.news.prodigy.com...

<snip>

> > I am delighted to hear you wouldn't give your work to a customer. Many
> > prototypes are unsuited for the customer to see anyway due to the rework
and
> > handling in engineering test. I NEVER ship a 'prototype' to anyone. That
is
> > what a "first Article" is for!
>
> Hear Hear!
>
> Reflow machines are best suited to soldering smt. If you have to do it
> by hand, use hot air. A bloody great soldering is the worst way.

Since that is what they were designed for, and that is what I use them for when
it is appropriate.

> > As for the work I cited! These were weather Satellite boards, RF, motor
> > control, CPU, and digital communications, plus low level analog video, with
> > analog to digital conversion. There will only be 18 final units built, and
> > testing (with temperature cycling from -40 to + 80 Degrees C four times a
day
> > at 5 degrees C per minute) was eight times a day, total time of a complete
test
> > was 2,000 hours. MTTF predicted is 18 years. Also they must survive 50

(Op's)


> > Kilorads exposure.
>
> ouch.
>
> > Yes, Inspection under a microscope, 20 and 50 diameters magnification.
Before
> > and after tests. Yes All boards were also tested on a shake table, they
must
> > survive launch.
> >
> > The Customer is NASA, they are very particular, and will launch the first
of
> > these in 2006.

By the way, all these boards MAY be hand soldered in the limited production.
There are components which can be reliably flow soldered, but these boards are
populated on both sides, and depending upon weight MAY not remain in place
going through the reflow process with an already soldered side down. Ordinary
FR4 will usually work this way, but the aluminum cored boards get too hot on
the bottom when the core conducts the heat through the board. (There is no
"convection cooling" in space. Only radiation and conduction.)

> > Shooting one's mouth off when someone tries to help causes a loss of
> > credibility!
> > Since your really an amateur, live with your poor workmanship and cry about
it!
>

> What makes you think I'm an amateur? I just don't want to hire a tech
> (labor laws become a real pain in the ass when you have staff).
> Cheers
> Terry

Your statements were a strong clue, then the lack of experience added fuel. I
would hope I was wrong! I only maintain five consultants (1099) on call, all
specialists! I do the initial design, and work along side of experienced
specialists for a quality result.

Sometimes I take my entire team into a customers facility, it helps to have
people with all those training certifications and credentials.

Thanks for the warning about Macon. I'll avoid them!


Paul Burke

unread,
Dec 2, 2004, 3:11:48 AM12/2/04
to
remove two items of clothing wrote:

> I'll give this a go with the blutack (we had the same thing in Australia -
> wonder what the UK equivalent is...)

Parkin

Howard Long

unread,
Dec 2, 2004, 5:36:45 AM12/2/04
to
> I'll give this a go with the blutack (we had the same thing in Australia -
> wonder what the UK equivalent is...) and desoldering braid.

It's the tiniest piece of blutak - too much and the chip's leads don't rest
in contact with the PCB solder pads. This allows you to position the chip
accurately by sight over the solder pads. The blutak then remains there ad
infinitum (or until you have to rework the chip!).

In the US blutak's like this
http://www.staples.com/Catalog/Browse/sku.asp?PageType=1&Sku=334690&bcFlag=True&bcSCatId=1&bcSCatName=Office+Supplies&bcCatId=28&bcCatName=Tape%2C+Glue+%26+Adhesives&bcClassId=10000&bcClassName=Glue+%26+Adhesive+Products

> I think I also need a smaller soldering iron tip - the last one was still
> too big and bulky with a 1 or 2 mm point.

Here's the iron I use
http://www.maplin.co.uk/Module.aspx?ModuleNo=10271&TabID=1&source=15&WorldID=9&doy=2m12

I use the same sized tip that was supplied with the iron - it's pointy but
not miniscule.

Cheers, Howard


Watson A.Name - "Watt Sun, the Dark Remover"

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Dec 2, 2004, 8:49:34 AM12/2/04
to

"Howard Long" <how...@howardlongxxx.com> wrote in message
news:comr7t$441$1...@sparta.btinternet.com...
[snip]

> > I think I also need a smaller soldering iron tip - the last one was
still
> > too big and bulky with a 1 or 2 mm point.
>
> Here's the iron I use
>
http://www.maplin.co.uk/Module.aspx?ModuleNo=10271&TabID=1&source=15&Wor
ldID=9&doy=2m12

I read the text in that ad three times, and I still couldn't find
anything that said what the wattage was. Why would they leave out
someething so important?

Clarence

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Dec 2, 2004, 6:06:21 PM12/2/04
to

"Terry Given" wrote

> Clarence wrote:
> > "Terry Given" <my_...@ieee.org> wrote in message
> > <snip>

> > Thanks for the warning about Macon. I'll avoid them!
>

> Actually its not Marcon per se, its just that the larger ceramic caps
> have mechanical resonance's that can be excited electrically. square-loop
> ferrite has the same problem - witness the warnings in the Ferroxcube
> databook.
>
> Cheers
> Terry

Like the 2.2mF to 100mF units I normally use?

Never seen any warnings. They are not piezoelectric.


Ian

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Dec 3, 2004, 5:21:48 AM12/3/04
to

"Watson A.Name - "Watt Sun, the Dark Remover"" <NOS...@dslextreme.com> wrote
in message news:10qu79b...@corp.supernews.com...

>
> "Howard Long" <how...@howardlongxxx.com> wrote in message
> news:comr7t$441$1...@sparta.btinternet.com...
> [snip]
>
> > > I think I also need a smaller soldering iron tip - the last one was
> still
> > > too big and bulky with a 1 or 2 mm point.
> >
> > Here's the iron I use
> >
> http://www.maplin.co.uk/Module.aspx?ModuleNo=10271&TabID=1&source=15&Wor
> ldID=9&doy=2m12
>
> I read the text in that ad three times, and I still couldn't find
> anything that said what the wattage was. Why would they leave out
> someething so important?
>
Look in the FAQ tab - 48W.

Regards
Ian


Larry Brasfield

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Dec 3, 2004, 12:26:25 AM12/3/04
to
"Clarence" <n...@No.com> wrote in message news:JfQrd.27826$zx1....@newssvr13.news.prodigy.com...
> Electrical excitation to mechanical resonance is the DEFINITION of
> "piezoelectric."


No, that is not right at all. A material can be piezoelectric
even when configured such that no resonance can occur.
Mechanical resonance is an extensive property, applicable
to a specific object with particular boundaries. In contrast,
a material itself, (regardless of its shape), has piezoelectic
parameters defining an intensive property, applicable to
infinitessimal volumes.

Perhaps, if you are going to "correct" people and set out
to "educate" them, you should be careful that you are not
simply throwing out some vague notions that you have
inadvertantly collected.

Terry Given

unread,
Dec 2, 2004, 5:01:16 PM12/2/04
to
Clarence wrote:

Actually its not Marcon per se, its just that the larger ceramic caps
have mechanical resonances that can be excited electrically. square-loop

Clarence

unread,
Dec 2, 2004, 9:33:13 PM12/2/04
to

"Terry Given" <my_...@ieee.org> wrote in message
news:ZZOrd.21704$9A.3...@news.xtra.co.nz...

C4532X7R2A225M By TDK 2.2uF 100V (since your into SI (stupid interference))
Up to and including C4532Y5V1A107Z 100uF 10V
And NOJC107M004RWJ 100uF 4V Y5V

These are all 1812 SMT parts.
>
> you use 0.1 farad ceramic caps? those I'd like to see. What's the
> dielectric? (or perhaps you use "mF" to mean micro-Farads - quaint but
> confusing, given the preponderance of SI units nowadays). I did once see
> a 100uF 200V (IIRC) NPO cap (mil smps). very very expensive - US$300 IIRC.
>
> AFAICR the piezoelectric behavior was not the issue - just electrically
> exciting them at their mechanical resonant frequencies.

Terry Given

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Dec 2, 2004, 8:06:00 PM12/2/04
to
Clarence wrote:

you use 0.1 farad ceramic caps? those I'd like to see. Whats the

dielectric? (or perhaps you use "mF" to mean micro-Farads - quaint but
confusing, given the preponderance of SI units nowadays). I did once see
a 100uF 200V (IIRC) NPO cap (mil smps). very very expensive - US$300 IIRC.

AFAICR the piezoelectric behaviour was not the issue - just electrically

exciting them at their mechanical resonant frequencies.


Cheers
Terry

Terry Given

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Dec 2, 2004, 8:07:19 PM12/2/04
to
John Fields wrote:

> On Thu, 02 Dec 2004 23:06:21 GMT, "Clarence" <n...@No.com> wrote:
>
>
>
>>Like the 2.2mF to 100mF units I normally use?
>
>

> ---
> Pretty large value for ceramics, eh?
> ---


>
>
>>Never seen any warnings. They are not piezoelectric.
>
>

> ---
> It's not necessary for a capacitor to be piezoelectric to exhibit a
> mechanical resonance or to be microphonic. All that's required is for
> the dielectric to be mechanically deformable by the forces exerted by
> the electric field across it or for the dielectric to be deformed by
> external mechanical forces.
>

And if the mechanical resonant frequency is the same as the electrical
excitation, significant (wrt the cap) forces can build up over time.
2220 and bigger were noted in the Marcon paper.

Cheers
Terry

Clarence

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Dec 3, 2004, 2:31:53 AM12/3/04
to

"Larry Brasfield" <donotspam_la...@hotmail.com> wrote in message
news:2OSrd.386$et5....@news.uswest.net...

> "Clarence" <n...@No.com> wrote in message
news:JfQrd.27826$zx1....@newssvr13.news.prodigy.com...
> > Electrical excitation to mechanical resonance is the DEFINITION of
> > "piezoelectric."
>
> No, that is not right at all. A material can be piezoelectric
> even when configured such that no resonance can occur.
> Mechanical resonance is an extensive property, applicable
> to a specific object with particular boundaries. In contrast,
> a material itself, (regardless of its shape), has piezoelectric

> parameters defining an intensive property, applicable to
> infinitesimal volumes.

>
> Perhaps, if you are going to "correct" people and set out
> to "educate" them, you should be careful that you are not
> simply throwing out some vague notions that you have
> inadvertently collected.
> --
> --Larry Brasfield
> email: larry_b...@hotmail.com

> Above views may belong only to me.

I am not sure I understand what your trying to say. It appears to be
speculation.
I was about to reply, then I read your disavowal. I see you are aware that you
are only vaguely familiar with the phenomena. A piezoelectric material which
has not been shaped, or which has no electrodes attached to excite the
piezoelectric properties is not affected in a predictable manner. So if a
material with those piezoelectric is applied in a product it "MAY" behave in a
way which creates stress. However AFAIK piezoelectric quartz, barium titanate,
or other piezoelectric materials are NOT routinely used in the production of
capacitors. It takes relatively high voltages to get much movement in
piezoelectric materials. Lose molecules would not have any effect at all since
it is the matrix of crystal formation which exhibits the property.

I designed equipment to solder leads on crystals and we measured the flexure in
tens of micro inches. Placing material in a position where movement was
inhibited, as in a potting compound, reduced movement to fractions of a micro
inches. Resonance would vanish with inhibiting pressure applied.

Unlike a ferrite, or crystal quartz, alumna used for SMT components do not
exhibit piezoelectric properties.

If your aware of any other piezoelectric materials please list them. I can
think of many applications for a low cost piezoelectric operated mechanical
device.

BTW: The soldering process should Twine the piezoelectric material if it was
present. Heat destroys the piezoelectric properties in the same manner as
magnets are demagnetized.

John Fields

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Dec 2, 2004, 7:10:24 PM12/2/04
to
On Thu, 02 Dec 2004 23:06:21 GMT, "Clarence" <n...@No.com> wrote:


>Like the 2.2mF to 100mF units I normally use?

---


Pretty large value for ceramics, eh?
---

>Never seen any warnings. They are not piezoelectric.

---


It's not necessary for a capacitor to be piezoelectric to exhibit a
mechanical resonance or to be microphonic. All that's required is for
the dielectric to be mechanically deformable by the forces exerted by
the electric field across it or for the dielectric to be deformed by
external mechanical forces.

--
John Fields

Leif Erickson

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Dec 2, 2004, 11:51:49 PM12/2/04