60/40 vs. 63/37 Solder
Joe
where one is better than the other?
I understand the eutectic nature of 63/37, and I wonder if/when 60/40
might ever be better to use.
--- Joe
John Doe
> Why are there these two very similar solders? Is there any
> situation where one is better than the other?
Dunno, but... If you do detail work, try water-soluble flux
solder. You just wipe off the residue for a sparkling clean
circuit.
Good luck and have fun.
Smitty Two
John Doe <jd...@usenetlove.invalid> wrote:
60/40 was the standard for many years, until it was learned that 63/37
was more accurately eutectic. 60/40 was kept around as a legacy product
since millions of customers worldwide had written the spec into their
procedural documentation. But distributors (in my part of the world
anyway) stopped stocking much of a 60/40 selection about 20 years ago.
As for water soluble flux, it has at least one significant drawback; it
is corrosive at room temperature (unlike RMA for example which is only
"active" when heated.) Therefore, any flux residue left on the board (or
whatever you're soldering) will lead to corrosion. Without full
immersion in a sonic tank, it can be difficult or impossible to wash it
all away.
PeterD
The advantage is when you need a lower melting temperature. However,
the difference is slight. 63/37 also does not have as much of a
plastic state when melting.
William Sommerwerck
63/37 has been "known" to be eutectic for at least 50 years. (I read about
it in "Popular Electronics" as a wee babe.)
The only reason 60/40 was ever manufactured in the first place is that tin
is more expensive than lead, so 63/37 solder costs more. Unless you're
Really Cheap, 63/37 is always preferable. It has slightly greater mechanical
strength, too, though this is rarely a consideration.
J Gordon Holt, who founded "The Stereophile", had his own theories about
soldering. Back in the days when people assembled vacuum-tube equipment from
kits, he recommended simply poking component leads through the lugs, and
soldering them without crimping them. His reasoning was that, if the
component ever needed replacement, you wouldn't have to fiddle with
uncrimping it. (If you've ever unsoldered old equipment, you know what a
tsuris this can be.) The "catch", of course, is that both the lug and the
lead have to be very clean, and you're more likely to get a cold or
incomplete connection. This is a situation where you would /definitely/ want
to use 63/37.
While I'm on the subject... I once asked the late Bob Tucker, * who wrote
the user manuals for Dynaco, why the soldering instructions were, at one
point, obviously in the "wrong" sequence. He explained that Dynaco's
"policy" was that, once a lug had three wires in it, it was to be soldered.
There was otherwise too-great a chance of it being overlooked and remaining
unsoldered, only to cause problems down the line.
* Bob, who passed on in the late '80s, was one of the nicest, most-gracious
people you could ever hope to meet. He was, perhaps surprisingly, also one
of the handsomest men I've ever seen -- by comparison, most actors and
fashion models are plain -- but he didn't seem aware of it.
Boris Mohar
Water soluble flux is conductive. You should wash it off not just wipe it.
--
Boris
John Larkin
And one that makes a great humidity sensor.
John
Smitty Two
"William Sommerwerck" <grizzle...@comcast.net> wrote:
> The only reason 60/40 was ever manufactured in the first place is that tin
> is more expensive than lead, so 63/37 solder costs more.
Cite, please? (and I don't mean a link to commodity prices)
Robbie Hatley
"Joe" wrote:
> I wonder if ... 60/40 might ever be better to use.
No.
For hand soldering, I recommend Sn63Pb37 wire solder with an activated
rosin flux core. Use thin solder, about 23AWG; it melts the faster, for less
chance of cold joints. For surface mount, use even thinner, about 28AWG.
Avoid organic or water-soluable flux unless you're going to wash the board
thoroughly after soldering.
Rosin flux can be removed with 99pct isopropyl alcohol ($1 a bottle at your
corner drug store). But frankly, I recommend NOT removing the rosin flux
scum. Leave it on; it's inert, airproof, waterproof, sweatproof, so it protects
the joint.
--
Been soldering stuff since 1973,
Robbie Hatley
lonewolf [[at]] well [[dot]] com
William Sommerwerck
>> that tin is more expensive than lead, so 63/37 solder costs more.
> Cite, please? (and I don't mean a link to commodity prices)
I can only cite "common sense". 63/37 has always been more-expensive than
60/40.
George Herold
<jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
Yeah, My prototype of a board with several high meg resistors (up to 1
gig.) was put together by myself with old Kester "44" (rosin flux.)
Worked great. Production did a few with their favorite water based
flux... No good! Now I have to convince them to go back to the old
standard. The new ROHS fluxes seem to be even worse. I measured a
few meg ohms between pads that had been 'cleaned'.... NOT.
George H.
GregS
>On Jul 15, 11:42=A0am, John Larkin
><jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
>> On 15 Jul 2010 08:04:55 GMT, John Doe <j...@usenetlove.invalid> wrote:
>>
>> >none given.now (Joe) wrote:
>>
>> >> situation where one is better than the other? =A0
>>
>> >Dunno, but... If you do detail work, try water-soluble flux
>> >solder. You just wipe off the residue for a sparkling clean
>> >circuit.
>>
>> And one that makes a great humidity sensor.
>>
>> John
>
>
>Yeah, My prototype of a board with several high meg resistors (up to 1
>gig.) was put together by myself with old Kester "44" (rosin flux.)
>Worked great. Production did a few with their favorite water based
>flux... No good! Now I have to convince them to go back to the old
>standard. The new ROHS fluxes seem to be even worse. I measured a
>few meg ohms between pads that had been 'cleaned'.... NOT.
>
I had a lot of problems with high Z circuitry. Got under the pads.
Some boards I had to clean/dry 10 times. In the interim, some of the cleaner
I used got into some caps and started their own circuit mess.
greg
David Eather
PeterD mentioned the significant parameter in his post. because it is a
eutectic mixture 63/37 does not have "much of a plastic state" this
means it is more sensitive to movement in the joint while the solder is
cooling - if the connections are unstable it forms more dry joints. This
was important with point to point wiring but is now less important with
PCBs.
You can normally use either solder for any job but the "old timers"
experience would suggest 60/40 is the better choice for wiring front
panels, flying leads and the like and 63/37 would be better for heat
sensitive components.
(for the obnoxious who will claim there is no difference - please note
that those doing the jobs *did* find a difference and thought it
significant enough to bother about)
Dave Platt
My understanding is that 60/40 has somewhat better wetting properties
than 63/37, at least with some contact materials. Some people prefer
it for that reason.
63/37 makes a sharp transition between liquid state and solid state at
a single, well-defined temperature. 60/40 goes through a transition
between these two states over a significant range of temperature - in
between the fully-solid and fully-liquid states it can have a somewhat
mushy texture. Some people feel that 60/40 brings with it a somewhat
higher risk of creating a "cold" solder joint (inadequate fusion with
the contact surfaces) if the joint is moved or stress while the solder
is dropping through its mushy-state temperature region.
--
Dave Platt <dpl...@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
William Sommerwerck
> of a plastic state". This means it is more [sic] sensitive to
> movement in the joint while the solder is cooling -- if the
> connections are unstable it forms more [sic] dry joints.
I don't what you meant to say, but what you did say is backwards. Eutectic
solder is less likely to produce a dry or crystallized joint.
Jim Yanik
news:i1nqh7$7qt$1...@news.eternal-september.org:
I agree;
the eutectic joint solidifies faster and thus less likely to move while the
solder is still "plastic".
--
Jim Yanik
jyanik
at
localnet
dot com
Smitty Two
"William Sommerwerck" <grizzle...@comcast.net> wrote:
Then you can't substantiate your contention that 60/40 was THE worldwide
standard for tens of years just because it was a few pennies cheaper per
pound? That is the statement of yours with which I take issue.
William Sommerwerck
>>>> that tin is more expensive than lead, so 63/37 solder costs more.
>>> Cite, please? (and I don't mean a link to commodity prices)
>> I can only cite "common sense". 63/37 has always been
>> more-expensive than 60/40.
> Then you can't substantiate your contention that 60/40 was THE
> worldwide standard for tens of years just because it was a few pennies
> cheaper per pound? That is the statement of yours with which I take issue.
I have no objection to your objection.
However, 60/40 was never, ever, "a few pennies per pound" cheaper than
63/37. For the last 30 years, the price of eutectic solder has been
sufficiently higher to make one think twice before buying it. The last time
I purchased solder, I decided that a one-pound roll of Kester 44 would last
the rest of my life, and I splurged. (At this point in my life, my
prediction is coming true. I rarely solder any more. If I drop dead, someone
digging through the junk will find a pleasant surprise. Assuming they know
what 63/37 is.)
I just checked Parts Express, and a 1# roll of Kester 44 60/40 is $22.23.
63/37 is $26.85. That's a $4.62 difference, almost 21% more -- hardly
"pennies per pound". When I bought the same product some years back, my
memory is that the price was around $7.50 for the 60/40, $9 for the 63/37.
Even that wasn't "pennies per pound".
I looked at the MCM site for Ersin products. Get this... MCM describes its
house brand of 60/40 solder as "provid[ing] the lowest possible melting
point".
Businesses almost always try to cut every corner they can. If you think your
solderers -- or soldering machines -- are doing a good job, you might prefer
to buy the less-expensive 60/40.
When I worked at Bendix Field Engineering, I often walked through the
section where a bunch of women (never men) soldered assemblies, following
NASA standards. I never thought to ask whether they used 60/40 or 63/37.
Dave Plowman (News)
Robbie Hatley <see.m...@for.my.contact.info> wrote:
> Rosin flux can be removed with 99pct isopropyl alcohol ($1 a bottle at
> your corner drug store). But frankly, I recommend NOT removing the
> rosin flux scum. Leave it on; it's inert, airproof, waterproof,
> sweatproof, so it protects the joint.
Strange to see this in print, as everyone seems to spend ages removing
flux. I don't and have never had a problem.
--
*The only difference between a rut and a grave is the depth.
Dave Plowman da...@davenoise.co.uk London SW
To e-mail, change noise into sound.
William Sommerwerck
> ($1 a bottle at your corner drug store).
You won't find 99% for $1. (91%, maybe.)
GregS
If you can get 95% ethanol, I thinks its best. By the time
you use 98 or 99% it absorbs water anyway on the board,
and you still have a water residue. You can also drink it.
greg
Jim Yanik
maybe the price difference is due to "new and improved" rather than any
other reason.
BTW,63/37 has the lowest melt point of all the tin/lead alloys. 361 deg F
Jim Yanik
>> Rosin flux can be removed with 99% isopropyl alcohol
>> ($1 a bottle at your corner drug store).
>
> You won't find 99% for $1. (91%, maybe.)
>
>
>
91% is what CVS sells,I don't recall the price,though.
William Sommerwerck
> rather than any other reason.
No, eutectic solder has always been more expensive, and the reason has
always been that tin is more-expensive than lead.
> 63/37 has the lowest melt point of all tin/lead alloys, 361 F
Exactly. That was my point, and MCM's error. I remember the little phase
diagram in the Popular Electronics article.
William Sommerwerck
Drug stores periodically have sales. You should be able to get a pint bottle
of 91% for less than a dollar. No point in the 75% stuff.
George Herold
>
> - Show quoted text -
What kind of flux were you using? I want to try some tests, just
laying down solder and flux gobs on 0805 SMD pads and measure the
resistance. Then cleaning and remeasuring. (I've got a bunch of
other 'fires' that I'm putting out so this may be a few days.)
George H.
David
"Jim Yanik" <jya...@abuse.gov> wrote in message
news:Xns9DB76443FE679...@216.168.3.44...
The Meijer store here in Illinois has 99% isopropyl. It is
normally about $1.25 for a 16 oz. bottle but occasionally
they run sales of 2 for 1 at that same price. I stocked up
with about a dozen bottles the last time they ran that sale.
I avoid the lower % stuff because it is not always diluted
with just water but sometimes oils and skin lotions. These
are to be avoided for electronics work.
David
William Sommerwerck
> with just water but sometimes oils and skin lotions.
> These are to be avoided for electronics work.
This is usually labelled "rubbing alcohol".
Jeff Liebermann
<see.m...@for.my.contact.info> wrote:
>Rosin flux can be removed with 99pct isopropyl alcohol ($1 a bottle at your
>corner drug store).
I prefer the hardware store stuff in the metal cans:
<http://www.acehardware.com/product/index.jsp?productId=3958489>
More expensive but always 99% (ignoring what moisture it absorbs from
the air).
>But frankly, I recommend NOT removing the rosin flux
>scum. Leave it on; it's inert, airproof, waterproof, sweatproof, so it protects
>the joint.
I have some rolls of solder around the shop that are not well labeled
or identified. Rather than risk leaving corrosive flux on a board, I
prefer to clean most everything.
--
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
GregS
I like 63/37 because some stuff I do I like it as low a temp as possible.
Deja vu. I worked for BFEC at NASA site, and went to NASA ssoldering school.
I would guess 60/40 would be the norm.
greg
Jeff Liebermann
wrote:
>
>>Why are there these two very similar solders? Is there any situation
>>where one is better than the other?
>>
>>I understand the eutectic nature of 63/37, and I wonder if/when 60/40
>>might ever be better to use.
>
>My understanding is that 60/40 has somewhat better wetting properties
>than 63/37, at least with some contact materials. Some people prefer
>it for that reason.
>
>63/37 makes a sharp transition between liquid state and solid state at
>a single, well-defined temperature. 60/40 goes through a transition
>between these two states over a significant range of temperature - in
>between the fully-solid and fully-liquid states it can have a somewhat
>mushy texture. Some people feel that 60/40 brings with it a somewhat
>higher risk of creating a "cold" solder joint (inadequate fusion with
>the contact surfaces) if the joint is moved or stress while the solder
>is dropping through its mushy-state temperature region.
True. 60/40 goes through a semi-molten, plastic-like state, while
63/37 goes instantly from liquid to solid. The joint is not
mechanically solid in this plastic state. It's not an issue with tiny
components, that cool down rather rapidly. However, large components,
that retain more heat, can product "cold" solder joints if moved while
in the is plastic state.
In some cases, this plastic state is desireable. For example,
pre-RoHS plumbers solder was 50/50 for both low cost and the ability
to remain workable over a wider range of temperatures.
<http://www.chemguide.co.uk/physical/phaseeqia/snpb.html>
<http://en.wikipedia.org/wiki/Solder>
This got my attention:
Some alloys, namely of lead and to some degree tin, contain small
but significant amounts of radioisotope impurities. The
radioisotopes undergoing alpha decay are a concern due to their
tendency to cause soft errors. Polonium-210 is especially
problematic; lead-210 beta decays to bismuth-210 which then beta
decays to polonium-210, an intense emitter of alpha particles.
Uranium-238 and thorium-232 are other significant contaminants of
lead containing alloys.
Oh swell.... something else to worry about.
William Sommerwerck
> as possible.
Allmost all my soldering is repairs; cold joints seem more likely when
you're fixing something.
> Deja vu. I worked for BFEC at NASA site, and went to NASA
> soldering school. I would guess 60/40 would be the norm.
Probably. I never had to solder, so I never went to school.
Which site? When? I worked from 1974 through 1978.
GregS
>On Jul 15, 3:40=A0pm, zekfr...@zekfrivolous.com (GregS) wrote:
>> In article <7a307a68-f754-413e-8113-4b9d0ce7a...@c10g2000yqi.googlegroups=
>..com>, George Herold <ggher...@gmail.com> wrote:
>>
>>
>>
>>
>>
>> >On Jul 15, 11:42=3DA0am, John Larkin
>> ><jjlar...@highNOTlandTHIStechnologyPART.com> wrote:
>> >> On 15 Jul 2010 08:04:55 GMT, John Doe <j...@usenetlove.invalid> wrote:
>>
>> >> >none given.now (Joe) wrote:
>>
>> >> >> situation where one is better than the other? =3DA0
>>
>> >> >Dunno, but... If you do detail work, try water-soluble flux
>> >> >solder. You just wipe off the residue for a sparkling clean
>> >> >circuit.
>>
>> >> And one that makes a great humidity sensor.
>>
>> >> John
>>
>> >Yeah, My prototype of a board with several high meg resistors (up to 1
>> >gig.) was put together by myself with old Kester "44" (rosin flux.)
>> >flux... No good! =A0Now I have to convince them to go back to the old
>> >standard. =A0 The new ROHS fluxes seem to be even worse. =A0I measured a
>> >few meg ohms between pads that had been 'cleaned'.... NOT.
>>
>> I had a lot of problems with high Z circuitry. Got under the pads.
>ner
>> I used got into some caps and started their own circuit mess.
>>
>> greg- Hide quoted text -
>>
>> - Show quoted text -
>
>What kind of flux were you using? I want to try some tests, just
>laying down solder and flux gobs on 0805 SMD pads and measure the
>resistance. Then cleaning and remeasuring. (I've got a bunch of
>other 'fires' that I'm putting out so this may be a few days.)
>
The boards were commercially made with water based flux.
I had to fix them. They actually laid out the boards, which was a mistake.
greg
GregS
William Sommerwerck
> http://zekfrivolous.com/goldstone
Did you ever change the klystron frequency from the control panel (there
were six buttons along the bottom), rather than going out to the
transmitter? If so, you used one of the improvements I installed.
Robbie Hatley
"GregS" recommends for flux removal:
> If you can get 95% ethanol, I thinks its best. By the time
> you use 98 or 99% it absorbs water anyway on the board,
> and you still have a water residue. You can also drink it.
And then you accidentally plug the 120VAC into the 5VDC output of
a voltage regulator, which promptly explodes and emits flames and
smoke, and you just have time to say "oh wow, man, pretty fireworks"
before the lights go out and the boss comes storming in saying "What the
hell is going on in here? Why is that circuit board flaming like that?
Someone grab the fire extinguisher!" Yep, ethanol works wonders,
but it's probably not best for job security. I think I'll stick with the
isopropanol.
GregS
I never ran that, but do recall them tuning them up. Something
rings a bell though about mods. As the 80's rolled through everything
was remote controled off site.
I do remember the time I pushed a button on one of the antenna motors,
and everything went black for miles.
I also remember the time one would go outside and point at the falling Skylab,
and the other person would try to move the antenna and lock on to it.
What with the 1 degree beamwidth was impossible. We were using Norads
predicts and they were too far off to be able to use. Somebody finally locked
onto the spacecraft and finally got good predicts.
I also remember the time we tracked the moon with a wrench.
For a while.
Big 85 ft.antenna made in Pittsburgh, as was much of the stuff made in the USA
back then.
greg
Michael A. Terrell
Jeff Liebermann wrote:
>
> On Thu, 15 Jul 2010 10:31:05 -0700, "Robbie Hatley"
> <see.m...@for.my.contact.info> wrote:
>
> >Rosin flux can be removed with 99pct isopropyl alcohol ($1 a bottle at your
> >corner drug store).
>
> I prefer the hardware store stuff in the metal cans:
> <http://www.acehardware.com/product/index.jsp?productId=3958489>
> More expensive but always 99% (ignoring what moisture it absorbs from
> the air).
>
> >But frankly, I recommend NOT removing the rosin flux
> >scum. Leave it on; it's inert, airproof, waterproof, sweatproof, so it protects
> >the joint.
>
> I have some rolls of solder around the shop that are not well labeled
> or identified. Rather than risk leaving corrosive flux on a board, I
> prefer to clean most everything.
I just tossed solder like that into my solder pot.
--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.
David Eather
When the joint moves while in the plastic stage it is still electrically
connected - when the joint moves with a eutectic mixture it cracks - the
joint is very weak when still close to the liquid stage. With the non
eutectic mixture the crystals of tin provide strength while the solid is
cooling.
I might not have explained it very well, but I assure you, with total
honesty, that the reason 60/40 was popular was the better reliability
for point to point soldering and the reason 63/37 is now taking its
place is that point to point has all but disappeared and the eutectic
mixture gives slightly lower thermal stress.
Either that, or you believe or antecedents were morons, who while they
knew about the eutectic mixture, were too stupid to use i,t or too
clumsy to mix it, or they thought a few dollars extra per ton of solder
was too much to pay for the good stuff.
Jeff Liebermann
<mike.t...@earthlink.net> wrote:
>Jeff Liebermann wrote:
>> I have some rolls of solder around the shop that are not well labeled
>> or identified. Rather than risk leaving corrosive flux on a board, I
>> prefer to clean most everything.
> I just tossed solder like that into my solder pot.
Right. Great idea. I did that once and regretted it. I tossed most
of a 1 lb roll of Ersin 362 (62/38) rosin core solder into the wire
lead tinning solder pot. The roll had gotten splattered with acid and
was leaking flux. The result was a large cloud of noxious smog, as
all the rosin simultaneously went up in smoke. You've seen the smoke
produced during soldering. Now multiply that by a few thousand times.
If it had set off the smoke alarm, I would have really been in
trouble. I don't know the correct way to recycle and remelt old
solder. Whatever it is, should probably be done outdoors.
--
# Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
# 831-336-2558
# http://802.11junk.com je...@cruzio.com
# http://www.LearnByDestroying.com AE6KS
William Sommerwerck
> -- the joint is very weak when still close to the liquid stage. With the
> non-eutectic mixture the crystals of tin provide strength while the
> solid is cooling.
I'm not an expert on the physics of materials, but this flies in the face of
what I think I understand.
How can a eutectic mixture ever be "close to" the liquid stage? To
paraphrase Yoda -- "It either is, or is not."
> I might not have explained it very well, but I assure you, with total
> honesty, that the reason 60/40 was popular was the better reliability
> for point to point soldering and the reason 63/37 is now taking its
> place is that point to point has all but disappeared and the eutectic
> mixture gives slightly lower thermal stress.
You might not consciously not be telling the truth, but that doesn't mean
what you say is correct.
> Either that, or you believe our antecedents were morons, who while
> they knew about the eutectic mixture, were too stupid to use it, or
> too clumsy to mix it, or they thought a few dollars extra per ton of
> solder was too much to pay for the good stuff.
The difference in price is not just "a few dollars extra per ton". A
significantly higher price is almost certainly the explanation.
When I was a kid and assembled kits, the instructions always warned that the
connection /had/ to be mechanically strong before it was soldered. (I
remember the Knight-Kit photographs very well.) This isn't true in
practice -- as I commented in a recent posting, J Gordon Holt fought against
it -- but it virtually guaranteed that the wires wouldn't move during the
soldering process. If the solderer heated the joint sufficiently, a cold
joint was essentially impossible, eutectic solder or not.
This didn't keep customers from making bad joints, or altogether missing
joints to be soldered. These, I believe, were the principal causes of
non-working kits. Eutectic solder would have helped only a little (ie,
there's a limit to how much you can prevent human error).
About a year ago I had to replace a high-current driver in an electronic
crossover. The device was a five-pin TO-style product. Removing the PC board
to unsolder it would have required removing all the input and output jacks.
(Yes!) So I had to clip the device's pins near the body, unsolder and pull
out the pin stubs, then suck out any remaining solder. I was grateful I had
eutectic solder, because it made it easy to re-fill the holes and suck them
clean, then solder in the new chip with virtual certainty the connection
would be good. (It was.)
Confession time... One basic rule of soldering is "Get the joint hot enough
to melt the solder. Do not melt the solder directly with the iron." I've
been ignoring that for nearly half a century, and have never had a bad
joint.
According to the Kester Website...
"Sn60 has a plastic range and puts down a slightly thicker coating of
solder. Sn60 is often preferred for lead tinning and other solder coating
applications. Sn63 is eutectic and as such has no plastic range. Generally
it flows better than Sn60 and is the preferred alloy for wave soldering and
surface mount applications."
This isn't a complete answer -- I assume the cheaper 60/40 makes sense when
coating, because no joint is involved. However, "flows better" seems to be a
desirable characteristic when soldering joints.
I'm willing to be proved wrong about anything. I'd like to see a document --
preferably from a solder manufacturer -- that explains why 60/40 is less
likely to produce a cracked joint than 63/37.
Jasen Betts
sounds like bullshit, alpha particles aren't energetic enough to get
even 1/10 of the way through the encapsulation on a RAM chip.
fraction of the
--- news://freenews.netfront.net/ - complaints: ne...@netfront.net ---
William Sommerwerck
>> This got my attention:
>> Some alloys, namely of lead and to some degree tin, contain small
>> but significant amounts of radioisotope impurities. The
>> radioisotopes undergoing alpha decay are a concern due to their
>> tendency to cause soft errors. Polonium-210 is especially
>> problematic; lead-210 beta decays to bismuth-210 which then beta
>> decays to polonium-210, an intense emitter of alpha particles.
>> Uranium-238 and thorium-232 are other significant contaminants of
>> lead containing alloys.
>> Oh swell.... something else to worry about.
> sounds like bullshit, alpha particles aren't energetic enough to get
> even 1/10 of the way through the encapsulation on a RAM chip.
Correct. The original writer was probably confused by the fact that the
materials ceramic ICs are made of can contain radioactive materials that can
cause errors.
k...@att.bizzzzzzzzzzzz
Happened in plastic too. Intel once helped the problem along by using Kr
instead of Ar, IIRC, in a hermaticity test.
Battleship steel has a lot of uses, too, since it was forged before the first
atmospheric tests.
Smitty Two
"William Sommerwerck" <grizzle...@comcast.net> wrote:
> >>>> The only reason 60/40 was ever manufactured in the first place is
> >>>> that tin is more expensive than lead, so 63/37 solder costs more.
>
> >>> Cite, please? (and I don't mean a link to commodity prices)
>
> >> I can only cite "common sense". 63/37 has always been
> >> more-expensive than 60/40.
>
> > Then you can't substantiate your contention that 60/40 was THE
> > worldwide standard for tens of years just because it was a few pennies
> > cheaper per pound? That is the statement of yours with which I take issue.
>
> I have no objection to your objection.
>
> However, 60/40 was never, ever, "a few pennies per pound" cheaper than
> 63/37. For the last 30 years, the price of eutectic solder has been
> sufficiently higher to make one think twice before buying it. The last time
> I purchased solder, I decided that a one-pound roll of Kester 44 would last
> the rest of my life, and I splurged. (At this point in my life, my
> prediction is coming true. I rarely solder any more. If I drop dead, someone
> digging through the junk will find a pleasant surprise. Assuming they know
> what 63/37 is.)
>
> I just checked Parts Express, and a 1# roll of Kester 44 60/40 is $22.23.
> 63/37 is $26.85. That's a $4.62 difference, almost 21% more -- hardly
> "pennies per pound". When I bought the same product some years back, my
> memory is that the price was around $7.50 for the 60/40, $9 for the 63/37.
> Even that wasn't "pennies per pound".
>
> Businesses almost always try to cut every corner they can. If you think your
> solderers -- or soldering machines -- are doing a good job, you might prefer
> to buy the less-expensive 60/40.
>
William, Parts Express sells to hobbyists. Their prices are meaningless
as a reference. I buy solder, as I have for 25 years, from industrial
suppliers. Since you didn't state either the diameter or the core, (and
diameter can make a huge difference in price) I looked up your
comparison rolls on Parts Express. I see you referred to Kester 44 with
a 66 core and at .031 diameter.
To compare apples to apples, I called my supplier yesterday for current
pricing: 63/37, $13.80/lb. 60/40, $13.30/lb. I also asked how many
people were buying 60/40, and she confirmed that well over 90% of
customers use 63/37.
1. You're paying nosebleed prices whichever formula you buy.
2. The cost difference is indeed pennies when purchased from real supply
houses
3. Regardless of the cost difference, 63/37 *is* the standard now, as it
has been for 20 years.
4. Based on #3 above, your assertion that companies will cut corners
anyway they can is false.
5. Therefore, my contention that the widespread switch was made due to
improved performance of 63/37 seems to be the only logical conclusion.
Now, you said that 63/37 eutectic nature was known 50 years ago. That
may or may not be true, but what is true is that the widespread
industrial changeover happened much more recently, about 20 years ago.
Smitty Two
David Eather <eat...@tpg.com.au> wrote:
>
> When the joint moves while in the plastic stage it is still electrically
> connected - when the joint moves with a eutectic mixture it cracks - the
> joint is very weak when still close to the liquid stage.
Here I'm going to agree with William and others that you're mistaken.
Eutectic means that the transition from liquid to solid occurs at the
same temperature as the transition from solid to liquid. By definition,
the joint *cannot* move with a eutectic mixture, except when the solder
is liquid. It's the plastic state of non-eutectic stuff that has the
potential to cause problems.
William Sommerwerck
> current pricing: 63/37, $13.80/lb. 60/40, $13.30/lb. I also asked
> how many people were buying 60/40, and she confirmed that
> well over 90% of customers use 63/37.
Fascinating. It raises the question of why there is such a huge difference
in the pricing of Kester's solders.
> Now, you said that 63/37 eutectic nature was known 50 years ago.
> That may or may not be true, but what is true is that the widespread
> industrial changeover happened much more recently, about 20 years
> ago.
Hey, I read it in Popular Electronics in the '60s. It was probably known
back in the '30s.
Smitty Two
"William Sommerwerck" <grizzle...@comcast.net> wrote:
> > To compare apples to apples, I called my supplier yesterday for
> > current pricing: 63/37, $13.80/lb. 60/40, $13.30/lb. I also asked
> > how many people were buying 60/40, and she confirmed that
> > well over 90% of customers use 63/37.
>
> Fascinating. It raises the question of why there is such a huge difference
> in the pricing of Kester's solders.
>
If you're referring to widely different prices from different suppliers,
it's the same with any product or service, of course. When the 99%
isopropyl topic come up, I plugged it into google's "shopping" tab.
Prices ranged from 2.79 to 14.50 for a pint of the stuff.
William Sommerwerck
>>> current pricing: 63/37, $13.80/lb. 60/40, $13.30/lb. I also asked
>>> how many people were buying 60/40, and she confirmed that
>>> well over 90% of customers use 63/37.
>> Fascinating. It raises the question of why there is such a huge
>> difference in the pricing of Kester's solders.
> If you're referring to widely different prices from different suppliers,
> it's the same with any product or service, of course. When the 99%
> isopropyl topic come up, I plugged it into google's "shopping" tab.
> Prices ranged from 2.79 to 14.50 for a pint of the stuff.
That isn't what I meant. There's a 20% difference in the price between
Kester's 60/40 and 63/37 solders.
Smitty Two
"William Sommerwerck" <grizzle...@comcast.net> wrote:
Oh, so you didn't read my post after all. To reiterate, 63/37 is 13.80,
60/40 is 13.30. That's uh, let's see, oh yeah, less than 4%.
William Sommerwerck
news:prestwhich-D3E21...@news.eternal-september.org...
<GASP!>
Yes, I DID read your post, and Yes, I did understand exactly what you said.
To wit... that there was almost no difference in the prices of the 60/40 and
63/37 solders from your supplier. That's why I raised the question about why
there WAS such a large difference between Kester's solders.
I think it was plain from what I wrote that I was wondering why there was
almost no difference in your supplier's prices for solders from (presumably)
the same manufacturer, while Kester solders had a 20% difference. (See
above.) Must /everything/ be explained in excruciating detail five times
over?
This happens over and over and over and over and over and over and over and
over, and not just to me. It's because people don't read carefully, then
think about what they've read. Believe me, I sometimes am about to respond
to a post, then discover I'm mis-understood it.
Dave Platt
William Sommerwerck <grizzle...@comcast.net> wrote:
>> Oh, so you didn't read my post after all. To reiterate, 63/37 is 13.80,
>> 60/40 is 13.30. That's uh, let's see, oh yeah, less than 4%.
>
><GASP!>
>
>Yes, I DID read your post, and Yes, I did understand exactly what you said.
>To wit... that there was almost no difference in the prices of the 60/40 and
>63/37 solders from your supplier. That's why I raised the question about why
>there WAS such a large difference between Kester's solders.
>
>I think it was plain from what I wrote that I was wondering why there was
>almost no difference in your supplier's prices for solders from (presumably)
>the same manufacturer, while Kester solders had a 20% difference. (See
>above.) Must /everything/ be explained in excruciating detail five times
>over?
I think you may have conflated two different issues here, when
comparing 60/40 and 63/37. One is the question of manufacture, one is
the question of distribution channel (hobby/retail vs. industrial).
I just did a lookup on Newark's website, comparing 23 AWG solders
manufactured by Kester. Take a look at the catalog page at
http://www.newark.com/jsp/content/printCatalog.jsp?display=single&cat=c127&page=2016
and the section on "44 series RA rosin core solder". They have both
63/37 and 60/40 alloy versions of many of the same sizes.
For the thinner-gauge varities, the prices for the two alloys seem to
be quite close... e.g. for 25-gauge, the 60/40 is $34.15 and the 63/37
is $34.72 (about 1%). 21-gauge is $24.54 and $25.17 (about 2%),
18-gauge is $22.80 and $24.77 respectively (about 9%).
The only really big disparity in favor of 60/40 is in the heavy
16-gauge size ($23.20 and $32.53 respectively). Perhaps this reflects
the fact that 16-gauge is used less commonly these days, or perhaps
Newark is just low in stock?
So... based on this evidence, it looks to me as if Kester does not
necessarily have a major price skew between the two alloys, at least
not in the gauges typically used for PC board assembly. This suggests
that the price disparity you cited, may have much more to do with the
pricing policies of the one retailer you mentioned (MCM) than they do
with the manufacturer's wholesale price. MCM might be pricing the
63/37 as a "premium" product, or perhaps they sell less of it and so
tend to amortize the per-SKU overhead costs over a smaller nmber of
units?
>This happens over and over and over and over and over and over and over and
>over, and not just to me. It's because people don't read carefully, then
>think about what they've read. Believe me, I sometimes am about to respond
>to a post, then discover I'm mis-understood it.
Yup. Happens to me too. As a language, English has enough room for
ambiguity and misunderstanding to make life interesting at times.
FYI, when one of the earlier posters said he'd checked solder prices
"from his supplier", I don't think he stated a brand at all... and yet
your reply seems to have assumed that he was *not* referring to
Kester. If you did assume that (and I'm only sorta assuming that you
assumed it :-) it might have misled you a bit.
--
Dave Platt <dpl...@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
Dave Platt
Jasen Betts <ja...@xnet.co.nz> wrote:
>sounds like bullshit, alpha particles aren't energetic enough to get
>even 1/10 of the way through the encapsulation on a RAM chip.
There were some problems with first-generation DRAM chips back in the
late 1970s, which were attributed to alpha-particle upsets due to
radio-isotopes in the encapsulating materials.
Cite: http://ieeexplore.ieee.org/xpl/freeabs_all.jsp?arnumber=1479948
Not having read the article I don't know how close to the silicon it
was necessary for the radioisotope in question to be, in order for the
resulting alpha particle to disrupt the chip's operation.
William Sommerwerck
> comparing 60/40 and 63/37. One is the question of manufacture, one is
> the question of distribution channel (hobby/retail vs. industrial).
I didn't conflate the issues, as the latter hadn't been raised when I first
brought up the point.
> So... based on this evidence, it looks to me as if Kester does not
> necessarily have a major price skew between the two alloys, at least
> not in the gauges typically used for PC board assembly.
It does in the case of the MCM catalog, at least for the gauge I looked at.
Other companies show similar huge disparities. It makes little sense, when
the ones you (and Smitty) cited are so close.
> FYI, when one of the earlier posters said he'd checked solder prices
> "from his supplier", I don't think he stated a brand at all... and yet
> your reply seems to have assumed that he was *not* referring to
> Kester. If you did assume that (and I'm only sorta assuming that you
> assumed it :-) it might have misled you a bit.
I wasn't mislead. Given the differenc in price, it was obvious it wasn't
Kester.
stra...@yahoo.com
wrote:
> "Joe" wrote:
> > I wonder if ... 60/40 might ever be better to use.
>
> No.
>
> For hand soldering, I recommend Sn63Pb37 wire solder with an activated
> rosin flux core. Use thin solder, about 23AWG; it melts the faster, for less
> chance of cold joints. For surface mount, use even thinner, about 28AWG.
>
> Avoid organic or water-soluable flux unless you're going to wash the board
> thoroughly after soldering.
>
> Rosin flux can be removed with 99pct isopropyl alcohol ($1 a bottle
at your
rosin flux
> scum. Leave it on; it's inert, airproof, waterproof, sweatproof,
so it protects
> the joint.
>
> Been soldering stuff since 1973,
> Robbie Hatley
> lonewolf [[at]] well [[dot]] com
If the flux burns it becomes conductive and WILL mess up CMOS modestly
high impedance nodes. That's why i clean it off.
G²
Michael A. Terrell
Jeff Liebermann wrote:
>
> On Fri, 16 Jul 2010 20:14:45 -0400, "Michael A. Terrell"
> <mike.t...@earthlink.net> wrote:
>
> >Jeff Liebermann wrote:
>
> >> I have some rolls of solder around the shop that are not well labeled
> >> or identified. Rather than risk leaving corrosive flux on a board, I
> >> prefer to clean most everything.
>
> > I just tossed solder like that into my solder pot.
>
> Right. Great idea. I did that once and regretted it. I tossed most
> of a 1 lb roll of Ersin 362 (62/38) rosin core solder into the wire
> lead tinning solder pot. The roll had gotten splattered with acid and
> was leaking flux. The result was a large cloud of noxious smog, as
> all the rosin simultaneously went up in smoke. You've seen the smoke
> produced during soldering. Now multiply that by a few thousand times.
> If it had set off the smoke alarm, I would have really been in
> trouble. I don't know the correct way to recycle and remelt old
> solder. Whatever it is, should probably be done outdoors.
I would NEVER add a pound of solder to an existing solder pot at one
time. When I bought my 6" diameter solder pot I had enough used solder
to more than fill it. It came from the use of a smaller solder pot to
salvage ICs from scrap PC boards. Float the board, then tap the corner
of the solder pot. A bunch of solder balls hit the aluminum plate the
pot was on. I would use a large pair of channel lock pliers to pick up
the hot pot to pour out some solder into a small aluminum pan, then dump
all the loose solder into the pot.
Solder pots are required to have an exhaust fan, in industrial
settings in my area.
Smitty Two
"William Sommerwerck" <grizzle...@comcast.net> wrote:
AH-SO! At last we're communicating. Yep, usenet is tough that way
sometimes. Here's the missing piece: The solder I buy IS KESTER. The
EXACT same stuff that you buy. Only two differences: The disparity in
formulations is less, and the price is roughly half.
Smitty Two
"William Sommerwerck" <grizzle...@comcast.net> wrote:
> I wasn't mislead. Given the differenc in price, it was obvious it wasn't
> Kester.
But it was, grasshopper. You paid too much, because you bought it from a
hobby supplier.
William Sommerwerck
> sometimes. Here's the missing piece: The solder I buy IS KESTER. The
> EXACT same stuff that you buy. Only two differences: The disparity in
> formulations is less, and the price is roughly half.
Fascinating. Perhaps someone, somewhere will have an explanation.
William Sommerwerck
>> it wasn't Kester.
> But it was, grasshopper. You paid too much, because you
> bought it from a hobby supplier.
Actually, I bought the solder at least 20 years ago, and I believe it came
from an electronics-supply store, not a "hobby supplier". I also paid less
than $10.
Jim Yanik
different businesses mark up at different prices.
name brands often go at higher rates,and less popular items may get priced
lower to move them.
--
Jim Yanik
jyanik
at
localnet
dot com
Smitty Two
Jim Yanik <jya...@abuse.gov> wrote:
As a side note, the wholesale pricing of solder also seems to be heavily
volume driven. A small distributor to hobbyists might buy a couple of
hundred pounds at a time, while a large industrial distributor buys tens
of thousands. They get a huge discount for that, and can easily pass
that savings on to their customers.
William Sommerwerck
> a couple of hundred pounds at a time, while a large industrial
> distributor buys tens of thousands. They get a huge discount for
> that, and can easily pass that savings on to their customers.
But we still don't have an answer to the question of why there is such a
wide disparity in the /relative/ pricing of 60/40 and eutectic solders.
Geoffrey S. Mendelson
> But we still don't have an answer to the question of why there is such a
> wide disparity in the /relative/ pricing of 60/40 and eutectic solders.
Because 60/40 is just solder, while 63/37 solder is an allowed under special
circumstances lead-free replacement and needs certification?
I know it's not lead free, but it's the solder you use when you have to
use leaded solder under lead free regulations.
Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel g...@mendelson.com N3OWJ/4X1GM
To help restaurants, as part of the "stimulus package", everyone must order
dessert. As part of the socialized health plan, you are forbidden to eat it. :-)
Phil Hobbs
folks going round to churches with lead roofs, offering them a new lead
roof in exchange for their old--and now low-alpha--lead ones.
Same with steel from old battleships.
Cheers
Phil Hobbs
--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058
hobbs at electrooptical dot net
http://electrooptical.net
Smitty Two
"William Sommerwerck" <grizzle...@comcast.net> wrote:
At the risk of misunderstanding you yet again, and mis-responding,
here's my shot at that:
Smaller distributors play on the "new and improved" perception that
someone up-thread mentioned, so they mark up the 63/37 more.
Larger industrial distributors play it a little straighter, with more
equal markups. But my side note could actually play into this, too: If
my supplier sells 10 times as much 63/37 as he does 60/40, then he
obviously buys 10 times as much, so Kester gives him a better price
break.
Smitty Two
"Geoffrey S. Mendelson" <g...@mendelson.com> wrote:
> William Sommerwerck wrote:
>
> > But we still don't have an answer to the question of why there is such a
> > wide disparity in the /relative/ pricing of 60/40 and eutectic solders.
>
> Because 60/40 is just solder, while 63/37 solder is an allowed under special
> circumstances lead-free replacement and needs certification?
>
> I know it's not lead free, but it's the solder you use when you have to
> use leaded solder under lead free regulations.
>
> Geoff.
Must be cocktail hour where you are, Geoff. Either that or I'm still
hungover and don't know it.
William Sommerwerck
>> a wide disparity in the /relative/ pricing of 60/40 and eutectic solders.
> Because 60/40 is just solder, while 63/37 solder is an allowed under
> special circumstances lead-free replacement and needs certification?
> I know it's not lead free, but it's the solder you use when you have to
> use leaded solder under lead free regulations.
The difference existed at least 30 years ago, when I bought my first roll of
eutectic.
William Sommerwerck
>> fact that the materials ceramic ICs are made of can contain
>> radioactive materials that can cause errors.
> No, the alphas from lead are a real problem. Ten years ago, there were
> folks going round to churches with lead roofs, offering them a new lead
> roof in exchange for their old--and now low-alpha--lead ones.
But where is the lead /within/ ICs? (The wires are bonded, not soldered.)
Alpha particles have poor penetrating power.
William Sommerwerck
>> a wide disparity in the /relative/ pricing of 60/40 and eutectic solders.
> At the risk of misunderstanding you yet again, and mis-responding,
> here's my shot at that:
> Smaller distributors play on the "new and improved" perception that
> someone up-thread mentioned, so they mark up the 63/37 more.
No, you're not misunderstanding, and what you say is logical. But... This
disparity existed 30 years ago, when I first bought a roll of eutectic
solder. At that time, eutectic was less-common and less asked-for. That
/might/ explain the difference.
Spehro Pefhany
Solder prices for single pound lots are all over the map- they change
with voltatile metal prices and some distributors may have old stock.
http://www.lme.com/tin_graphs.asp
http://www.lme.com/lead_graphs.asp
There's been roughly a 4:1 price range in lead and 2.5:1 in tin over
the past three years. Currently tin costs about 10x as much as lead,
so you'd expect about a 10-11% price difference due to cost of the
metals. At current prices there's around $5.30 worth of metals in a
pound of solder, of which only 30 cents or so is lead. There's also
the plastic spool, the cardboard box and 10-15 grams of flux.
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
tm
"Spehro Pefhany" <spef...@interlogDOTyou.knowwhat> wrote in message
news:b7i646p44pljor929...@4ax.com...
> On Sun, 18 Jul 2010 11:28:06 -0500, the renowned Jim Yanik
> <jya...@abuse.gov> wrote:
>
>>"William Sommerwerck" <grizzle...@comcast.net> wrote in
>>news:i1upmh$14a$1...@news.eternal-september.org:
>>
>>>> AH-SO! At last we're communicating. Yep, usenet is tough that way
>>>> sometimes. Here's the missing piece: The solder I buy IS KESTER. The
>>>> EXACT same stuff that you buy. Only two differences: The disparity in
>>>> formulations is less, and the price is roughly half.
>>>
>>> Fascinating. Perhaps someone, somewhere will have an explanation.
>>>
>>>
>>>
>>
>>different businesses mark up at different prices.
>>name brands often go at higher rates,and less popular items may get priced
>>lower to move them.
>
> Solder prices for single pound lots are all over the map- they change
> with voltatile metal prices and some distributors may have old stock.
>
> http://www.lme.com/tin_graphs.asp
> http://www.lme.com/lead_graphs.asp
>
> There's been roughly a 4:1 price range in lead and 2.5:1 in tin over
> the past three years. Currently tin costs about 10x as much as lead,
> so you'd expect about a 10-11% price difference due to cost of the
> metals. At current prices there's around $5.30 worth of metals in a
> pound of solder, of which only 30 cents or so is lead. There's also
> the plastic spool, the cardboard box and 10-15 grams of flux.
>
>
--- news://freenews.netfront.net/ - complaints: ne...@netfront.net ---
Smitty Two
Spehro Pefhany <spef...@interlogDOTyou.knowwhat> wrote:
> At current prices there's around $5.30 worth of metals in a
> pound of solder,
No wonder I haven't seen those $4.95/lb. bar solder sales lately. I used
to wait for those and stock up a couple hundred pounds for the soldering
machine.
William Sommerwerck
> over the past three years. Currently tin costs about 10x as
> much as lead, so you'd expect about a 10-11% price difference
> due to cost of the metals. At current prices there's around $5.30
> worth of metals in a pound of solder, of which only 30 cents or
> so is lead. There's also the plastic spool, the cardboard box
> and 10-15 grams of flux.
The fog is lifting...
John Fields
---
In the lead frame? ;)
Phil Hobbs
Only a problem with flip-chip (C4) bonding. At one point I worked in
the packaging research group at IBM Yorktown lab (no, I'm not a
packaging guy--it's a long story).
k...@att.bizzzzzzzzzzzz
<pcdhSpamM...@electrooptical.net> wrote:
>William Sommerwerck wrote:
>>>> Correct. The original writer was probably confused by the
>>>> fact that the materials ceramic ICs are made of can contain
>>>> radioactive materials that can cause errors.
>>
>>> No, the alphas from lead are a real problem. Ten years ago, there were
>>> folks going round to churches with lead roofs, offering them a new lead
>>> roof in exchange for their old--and now low-alpha--lead ones.
>>
>> But where is the lead /within/ ICs? (The wires are bonded, not soldered.)
>> Alpha particles have poor penetrating power.
>>
>>
>
>Only a problem with flip-chip (C4) bonding. At one point I worked in
>the packaging research group at IBM Yorktown lab (no, I'm not a
>packaging guy--it's a long story).
The C4 balls were lead-indium, IIRC.
Phil Hobbs
Lead-tin eutectic in my era (1987-2008), followed by gold-tin currently,
IIRC.
k...@att.bizzzzzzzzzzzz
<pcdhSpamM...@electrooptical.net> wrote:
>k...@att.bizzzzzzzzzzzz wrote:
>> On Sun, 18 Jul 2010 19:47:15 -0400, Phil Hobbs
>> <pcdhSpamM...@electrooptical.net> wrote:
>>
>>> William Sommerwerck wrote:
>>>>>> Correct. The original writer was probably confused by the
>>>>>> fact that the materials ceramic ICs are made of can contain
>>>>>> radioactive materials that can cause errors.
>>>>> No, the alphas from lead are a real problem. Ten years ago, there were
>>>>> folks going round to churches with lead roofs, offering them a new lead
>>>>> roof in exchange for their old--and now low-alpha--lead ones.
>>>> But where is the lead /within/ ICs? (The wires are bonded, not soldered.)
>>>> Alpha particles have poor penetrating power.
>>>>
>>>>
>>> Only a problem with flip-chip (C4) bonding. At one point I worked in
>>> the packaging research group at IBM Yorktown lab (no, I'm not a
>>> packaging guy--it's a long story).
>>
>> The C4 balls were lead-indium, IIRC.
>
>
>Lead-tin eutectic in my era (1987-2008), followed by gold-tin currently,
>IIRC.
The last time I dealt with any of this was in the mid '70s. Before TCMs, even
(LEMs). I'm pretty sure they were lead-indium, but there may have been tin in
there too. There was also an issue of polonium contamination causing
uncorrectable L1 errors, but that's a completely different issue.
Michael A. Terrell
Fred Abse wrote:
>
> On Sun, 18 Jul 2010 01:47:09 -0400, Michael A. Terrell wrote:
>
> > I would NEVER add a pound of solder to an existing solder pot at one
> > time. When I bought my 6" diameter solder pot I had enough used solder to
> > more than fill it. It came from the use of a smaller solder pot to
> > salvage ICs from scrap PC boards. Float the board, then tap the corner of
> > the solder pot. A bunch of solder balls hit the aluminum plate the pot
> > was on. I would use a large pair of channel lock pliers to pick up the hot
> > pot to pour out some solder into a small aluminum pan, then dump all the
> > loose solder into the pot.
>
> much copper, gold, etc. contamination there is?
No need to, really. it was used to salvage parts and tin wire. Most
of the boards were soldered with 80/20 so i had to add some scrap lead
from time to time, to lower the melting point. The other metals didn't
hurt anything.