Lead Based Solder Alternatives

[Ken Smith]

In the US, lead-based batteries must be recycled, and there is a fee
charged when you buy a new battery to pay for the recycling costs.

The actual recycling goes on elsewhere. The "boat loads" of dead
batteries are shipped overseas to be recycled.

 

[Rich Grise]

Not true. It said whatever it said about Pb, Hg, Cd, Cr+6, etc.

Cheers!
Rich
============================
Rich,

I don't understand your response. Unless you got a different copy of the
magazine than I did, my statement is true. My response was exactly what I
saw in the magazine and what I am looking at right now. It used exactly the
words I stated.

Thanks for those that provided useful references to review.

My point was only that it had mentioned cadmium, which would imply that
nickel-cadmium batteries, which have cadmium, would be covered.

Sorry.
Rich

 

[Rich Grise]

budgie wrote: [...]
The increased temperature for lead-free soldering is the one that
bothers me. For
decades, those semi makers have been telling us to keep exposure to heat to a
minimum.

The trend seems to be silver alloys with lower and lower melting points.
I think in a few years a silver, unobtainium, upsidaisium, alloy will be
found with a melting point that match Sn/Pb solder nicely.

Until then, there will be a reliability hit.

I wonder what a little gallium would do to the alloy.

Cheers!
Rich

 

[Ian Stirling]

budgie wrote: [...]
The increased temperature for lead-free soldering is the one that
bothers me. For
decades, those semi makers have been telling us to keep exposure to heat to a
minimum.

The trend seems to be silver alloys with lower and lower melting points.
I think in a few years a silver, unobtainium, upsidaisium, alloy will be
found with a melting point that match Sn/Pb solder nicely.

Until then, there will be a reliability hit.

I wonder what a little gallium would do to the alloy.

You can get metals that'll melt down to -40C or so, even if you exclude
mercury.

Indium/Gallium eutectic melts at around 40C.

 

[ChrisGibboGibson]

Here's the full document...

http://europa.eu.int/eur-lex/pri/en/oj/dat/2003/l_037/l_03720030213en00190
023.pdf

One of the problems with this new EU legislation is, as bloody usual, it was
incorrectly drafted, by idiots in the ivory towers or Brussels, in the first
place. (some of their previous attempts have taken them 4 drafts and 10 years
to get them right [they are *still* trying to get EMC regs correct after much
longer]).

The result, in this case, is that people are now arguing over the
interpretation of the document.

They can't say "0%". That would never work. You can find *some* of just about
any chemical in a potato. So they have to have a sensible limit.

Now the argument is "does that mean x% in the whole product?, x% in an IC? x%
on a PCB. Because the regs are unclear on this.

Different companies are interpreting it differently.

As usual with new EU regs it's a monumental **** up that will take them 10
years to rectify *after* they have made it law. As usual.

In the meantime, companies carry on trading, completely disregarding what they
tell us is now the law.

Eventually they might get it right. But so far they have failed.

Gibbo

 

[Ken Smith]

[...]
The increased temperature for lead-free soldering is the one that
bothers me. For
decades, those semi makers have been telling us to keep exposure to heat to a
minimum.

The trend seems to be silver alloys with lower and lower melting points.
I think in a few years a silver, unobtainium, upsidaisium, alloy will be
found with a melting point that match Sn/Pb solder nicely.

Until then, there will be a reliability hit.

I wonder what a little gallium would do to the alloy.

You can get metals that'll melt down to -40C or so, even if you exclude
mercury.

Indium/Gallium eutectic melts at around 40C.

I think it is more a matter of getting four requirements at the same time:

(1) It must melt at a reasonable temperature.

(2) If must wet copper well so it flows.

(3) It must not be brittle.

(4) Mere mortals have to be able to afford it.

I think they can do them one at a time and perhaps 2 at a time. Getting
all four requirements in the same alloy seems to be the issue. I figure
that there is enough money in it that if there is one it will be found.

 

[Mark Zenier]

Utterly hilarious. Although lead acid batteries rarely find themselves in
landfill - they get recycled. Consumer electronics ends up in landfill -
that's the reason for this.

Not landfills, incinerators.

Mark Zenier [email protected] Washington State resident

 

[Jeff]

What are people specifying in terms of bare boards? Sometimes we have
to order enough for over 12 months, so the deadline is fast
approaching.

Gold immersion is one recommendation (costs about 20% more IIRC). HASL (Hot
Air Solder Level) with lead free solder is a less common alternative (likely
have to have a HASL machine dedicated to lead free). Bare/coated copper does
not seem to be too common.

If you mean bare, unetched boards, then FR4 holds up well.

Best regards,
Spehro Pefhany

http://www.speff.com

 

[Paul Hovnanian P.E.]

Here are the solders that i know about:
1) Sn63, Pb37 MP is 183C (361F) with a max recommended use to 149C
(300F).
2) Sn95.8, Ag3.5, Cu0.7 MP is 217C (423F)
3) Sn96.5, Ag3.5 MP is 221C (430F)
4) Sn65, Sb5 MP is 232C (450F)
I have only personally worked with #1 and #4 and one needs a rather
hot iron to not get cold solder joints with #4.
That makes it a bitch, as that heat tends to make problems with the
ICs one is soldering...

What about various alloys of gold? Back in my days in the aerospace biz,
one vendor proposed using a gold alloy solder. Although it wasn't our
job to review this part of their design, we did toy with the idea of
asking them to ship us a couple of pounds of the proposed solder, 'for
certification purposes'. ;-)

 

[budgie]

On Sat, 06 Nov 2004 15:46:54 +0000, Ken Smith wrote:

[...]
The increased temperature for lead-free soldering is the one that
bothers me. For
decades, those semi makers have been telling us to keep exposure to heat to a
minimum.

The trend seems to be silver alloys with lower and lower melting points.
I think in a few years a silver, unobtainium, upsidaisium, alloy will be
found with a melting point that match Sn/Pb solder nicely.

Until then, there will be a reliability hit.

I wonder what a little gallium would do to the alloy.

You can get metals that'll melt down to -40C or so, even if you exclude
mercury.

Indium/Gallium eutectic melts at around 40C.

I think it is more a matter of getting four requirements at the same time:

(1) It must melt at a reasonable temperature.

(2) If must wet copper well so it flows.

(3) It must not be brittle.

(4) Mere mortals have to be able to afford it.

I think they can do them one at a time and perhaps 2 at a time. Getting
all four requirements in the same alloy seems to be the issue. I figure
that there is enough money in it that if there is one it will be found.

I think that's the thinking of the euro/japanese regulators - if you put a
timeline/deadline on it, money WILL be thrown at it and a solution will emerge.
My real fear is that hard deadlines usually result in 1-3 only.

 

[Robert Baer]

What about various alloys of gold? Back in my days in the aerospace biz,
one vendor proposed using a gold alloy solder. Although it wasn't our
job to review this part of their design, we did toy with the idea of
asking them to ship us a couple of pounds of the proposed solder, 'for
certification purposes'. ;-)

Do you have any info (element ratios and melting points)?

 

[Pooh Bear]

On Sat, 06 Nov 2004 15:46:54 +0000, Ken Smith wrote:

[...]
The increased temperature for lead-free soldering is the one that
bothers me. For
decades, those semi makers have been telling us to keep exposure to heat to a
minimum.

The trend seems to be silver alloys with lower and lower melting points.
I think in a few years a silver, unobtainium, upsidaisium, alloy will be
found with a melting point that match Sn/Pb solder nicely.

Until then, there will be a reliability hit.

I wonder what a little gallium would do to the alloy.

You can get metals that'll melt down to -40C or so, even if you exclude
mercury.

Indium/Gallium eutectic melts at around 40C.

I think it is more a matter of getting four requirements at the same time:

(1) It must melt at a reasonable temperature.

(2) If must wet copper well so it flows.

(3) It must not be brittle.

(4) Mere mortals have to be able to afford it.

I think they can do them one at a time and perhaps 2 at a time. Getting
all four requirements in the same alloy seems to be the issue. I figure
that there is enough money in it that if there is one it will be found.

I think that's the thinking of the euro/japanese regulators - if you put a
timeline/deadline on it, money WILL be thrown at it and a solution will emerge.
My real fear is that hard deadlines usually result in 1-3 only.

Yes indeed !

A *hilarious* sub section of the RoHS directive suggests that measures required should
not have an adverse financial effect !

Very funny.

Never mind the reliability effect due to increased temp processes !


Graham

 

[Pooh Bear]

The actual recycling goes on elsewhere. The "boat loads" of dead
batteries are shipped overseas to be recycled.

You mean ' recycled '.

Or dumped in a Chinese / Pakistani back yard as I recently heard.


Graham

 

[Ken Smith]

You mean ' recycled '.

Or dumped in a Chinese / Pakistani back yard as I recently heard.

The lead is worth too much to leave behind. Her's what I understand they
do:

(1)
Knock the caps off the battery and tip it upside down so the acid
drains out and into the soil.

(2)
Make a big pile of the drained batteries and pour gasoline on them. Throw
a match at them and wait while the plastic burns way.

(3)
Scoop up the remains and put them in a big pot.

(4)
Cut down some of the rain forest to build a fire under the big pot to melt
the lead.

(5)
Lead being heavy sinks to the bottom of the pot when it melts. The other
just floats on the surface, so you can get some children to scrap the junk
away from the melt.

(6)
Pour the recycled lead into molds to make it ready for return shipment.

 

[Ken Smith]

What about various alloys of gold? Back in my days in the aerospace biz,
one vendor proposed using a gold alloy solder. Although it wasn't our
job to review this part of their design, we did toy with the idea of
asking them to ship us a couple of pounds of the proposed solder, 'for
certification purposes'. ;-)

It may really be worth looking at. The amount of material involved isn't
all that much per unit. The joints would be made with layers about 1
atom thick.

There is a technology where a laser makes a velcro like surface on metal.
We could have boards where the parts are just pressed into place.

 

[Pooh Bear]

[...]
In the US, lead-based batteries must be recycled, and there is a fee
charged when you buy a new battery to pay for the recycling costs.

The actual recycling goes on elsewhere. The "boat loads" of dead
batteries are shipped overseas to be recycled.

You mean ' recycled '.

Or dumped in a Chinese / Pakistani back yard as I recently heard.

The lead is worth too much to leave behind. Her's what I understand they
do:

(1)
Knock the caps off the battery and tip it upside down so the acid
drains out and into the soil.

(2)
Make a big pile of the drained batteries and pour gasoline on them. Throw
a match at them and wait while the plastic burns way.

(3)
Scoop up the remains and put them in a big pot.

(4)
Cut down some of the rain forest to build a fire under the big pot to melt
the lead.

(5)
Lead being heavy sinks to the bottom of the pot when it melts. The other
just floats on the surface, so you can get some children to scrap the junk
away from the melt.

(6)
Pour the recycled lead into molds to make it ready for return shipment.

I can kind of believe that.

The dumping I confused with the batteries was ' general electrical goods '.
The West washes its hands this way it seems.

Graham

 

[Pooh Bear]

Not landfills, incinerators.

Landfill over here mainly. So the lead can leach out into the soil. UK's not
keen on incinerators. Good way of getting the lead into the air though.


Graham ;-)

 

[Pooh Bear]

What are people specifying in terms of bare boards? Sometimes we have
to order enough for over 12 months, so the deadline is fast
approaching.

Asian board stuffers often don't bother with any finish. Just put an anti-oxidant
laquer on the bare copper.


Graham

 

[nospam]

Landfill over here mainly. So the lead can leach out into the soil. UK's not
keen on incinerators. Good way of getting the lead into the air though.

Yeah we all know how soluble lead is, we only used it to make water pipes
for hundreds of years.

 

[Spehro Pefhany]

Asian board stuffers often don't bother with any finish. Just put an anti-oxidant
laquer on the bare copper.

Yeah, I know, and it lasts fairly well if you keep the boards dry and
in plastic bags. Cardboard is bery bad for them.


Best regards,
Spehro Pefhany