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'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.

On 2010-07-16, Jeff Liebermann wrote:
On Thu, 15 Jul 2010 13:06:03 -0700, (Dave Platt)
wrote:



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.

sounds like bull****, 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: ---

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.

sounds like bull****, 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.

On Sat, 17 Jul 2010 06:28:08 -0700, "William Sommerwerck"
wrote:

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.

sounds like bull****, 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.

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.

In article ,
"William Sommerwerck" 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.

In article ,
David Eather 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.

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.


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.

In article ,
"William Sommerwerck" 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.

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.

That isn't what I meant. There's a 20% difference in the price between
Kester's 60/40 and 63/37 solders.

In article ,
"William Sommerwerck" 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.

That isn't what I meant. There's a 20% difference in the price between
Kester's 60/40 and 63/37 solders.

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%.

"Smitty Two" wrote in message
news
In article ,
"William Sommerwerck" 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.

That isn't what I meant. There's a 20% difference in the price between
Kester's 60/40 and 63/37 solders.

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?

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.

In article ,
William Sommerwerck 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/pr...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 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!

In article ,
Jasen Betts wrote:

sounds like bull****, 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/freea...number=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.

--
Dave Platt 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!

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 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.

On Jul 15, 10:31*am, "Robbie Hatley"
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
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

If the flux burns it becomes conductive and WILL mess up CMOS modestly
high impedance nodes. That's why i clean it off.

G²

Jeff Liebermann wrote:

On Fri, 16 Jul 2010 20:14:45 -0400, "Michael A. Terrell"
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.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.

In article ,
"William Sommerwerck" wrote:

"Smitty Two" wrote in message
news
In article ,
"William Sommerwerck" 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.

That isn't what I meant. There's a 20% difference in the price between
Kester's 60/40 and 63/37 solders.

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?

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.

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.

In article ,
"William Sommerwerck" 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.

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.

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.

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.

"William Sommerwerck" wrote in
:

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.

--
Jim Yanik
jyanik
at
localnet
dot com

In article ,
Jim Yanik wrote:

"William Sommerwerck" wrote in
:

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.

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.

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.

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.

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.

--
Geoffrey S. Mendelson, Jerusalem, Israel 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. :-)

William Sommerwerck wrote:
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.

sounds like bull****, 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.


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.

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

In article ,
"William Sommerwerck" 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.

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.

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.

In article ,
"Geoffrey S. Mendelson" 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.

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.

The difference existed at least 30 years ago, when I bought my first roll of
eutectic.

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.

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.

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.

On Sun, 18 Jul 2010 11:28:06 -0500, the renowned Jim Yanik
wrote:

"William Sommerwerck" wrote in
:

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.


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

"Spehro Pefhany" wrote in message
...
On Sun, 18 Jul 2010 11:28:06 -0500, the renowned Jim Yanik
wrote:

"William Sommerwerck" wrote in
:

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.


And then there is the shipping.





--- news://freenews.netfront.net/ - complaints: ---

In article ,
Spehro Pefhany 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.

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.

The fog is lifting...

On Sun, 18 Jul 2010 11:44:51 -0700, "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.

---
In the lead frame?

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).


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

On Sun, 18 Jul 2010 19:47:15 -0400, Phil Hobbs
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.

zzzzzzzzzz wrote:
On Sun, 18 Jul 2010 19:47:15 -0400, Phil Hobbs
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.

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

On Sun, 18 Jul 2010 20:32:22 -0400, Phil Hobbs
wrote:

wrote:
On Sun, 18 Jul 2010 19:47:15 -0400, Phil Hobbs
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.

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.

So you don't really know the composition of the solder in the pot, or how
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.


--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.