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Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Immersion Silver Reliability

Mike

#28151

Immersion Silver Reliability | 20 April, 2004

1. Which manufacturers have proven the immersion silver is reliable after solder joint assembly? 2. Who has published guidelines for storing and handling immersion silver boards? 3. Is the immersion silver finish wire bondable? epoxy bondable? or just solderable?

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Ken

#28154

Immersion Silver Reliability | 20 April, 2004

ImAg is the Surface finish of choice for Intel mother boards....Tin/lead and lead free processes. I think palladium and soft gold are the preferred for wire bondable apps.

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#28155

Immersion Silver Reliability | 20 April, 2004

Companies that license immersion silver technology to board fabricators are: * Alpha Level Silver * Mac Dermid Sterling [Mac Dermid's TM]

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Mark

#28755

Immersion Silver Reliability | 24 May, 2004

I just got a report from MacDermid on Solder Mask Interface Attack Issue (SMIA) with Sterling Silver Process. Corrosive chemicals in the ImAg process get trapped under the soldermask edge and eat at the copper trace. They are experimenting with different processes to reduce the Cu attack.

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Bimal Patel

#28765

Immersion Silver Reliability | 25 May, 2004

We are doing assemblies using Immersion Silver coating for RF assembly for a while now. We did not have problem using 63/37 SN/PB solder paste untill recently. We started seeing black marks on the finish and around the solder joint recently. We have been blamed for the chemical reactions even though we use only water soluable paste and clean with no chemicals. How can I get report from MacDermid or can Mark please email me report ot b.subcon@verizon.net ? I suspect some trapped chemicals during the fabrication process.

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Bimal Patel

#28766

Immersion Silver Reliability | 25 May, 2004

We are doing assemblies using Immersion Silver coating for RF assembly for a while now. We did not have problem using 63/37 SN/PB solder paste untill recently. We started seeing black marks on the finish and around the solder joint recently. We have been blamed for the chemical reactions even though we use only water soluable paste and clean with no chemicals. How can I get report from MacDermid or can Mark please email me report to b.subcon@verizon.net ? I suspect some trapped chemicals during the fabrication process.

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#28783

Immersion Silver Reliability / Peelable mask | 26 May, 2004

Mark, that would be a good report to have a look at can you post it on the site or mail it out to me? Also I've been having an issue with blue peelable solder mask on silver boards where it peels the silver off with it. I've only seen this since my vendor moved to the MacD process, has anyone else seen this? From what i can see it looks like the silver bond is weaker than the bond of the mask against it as I'm left with a nice clean copper finish on the PCB. Not good for RF work really.

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#28788

Immersion Silver Reliability / Peelable mask | 26 May, 2004

Some peelable solder masks attack immersion finishes. It appears components in the peelable soldermask, such as ammonia, are not very friendly to these particular surface finish. [We've wanted to investigate the effect of mask application thickness on this type of problem, but so little time, so many donuts to eat.]

Similarly, do not use latex peelable solder mask with a no-clean (low res) process without extensive testing. The problem is usually the cure reaction and what outgasses from the mask during the curing.

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Bryan Sherh

#28802

Immersion Silver Reliability / Peelable mask | 27 May, 2004

Hello All, I 'd like to have some stuffs about immersion Silver to study with.Can anybody provide some information or some articles about Immersion silver? Thanks a lot. Bryan

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Bryan Sherh

#28803

Immersion Silver Reliability / Peelable mask | 27 May, 2004

Hello All, I 'd like to have some stuffs about immersion Silver to study with.Can anybody provide some information or some articles about Immersion silver? Thanks a lot. Bryan Bryan.she@163.com

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#28805

Immersion Silver Reliability / Peelable mask | 27 May, 2004

Contact the licensers of imm silver process, mentioned earlier in this thread.

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#28835

Immersion Silver Reliability / Peelable mask | 30 May, 2004

Hmm, the type of thing you'd expect the PCB vendor to warn you about or test prior to changing their process!.. fun & games.

So are they good donuts?

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#28836

Immersion Silver Reliability / Peelable mask | 30 May, 2004

Sure, I'd expect your PCB fab has given you a information sheet on handling, storage, and whatnot, including recommended temporary solder masks. The cats & kitties in the stockroom are the first people to start your search. It's probably squirreled-away in some receiving file. Well, maybe not.

Dunkin Donuts chocolate cake donuts are the best. We used to be BIG fans of Krispy Kream, but their star has faded -- too sweet.

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#28839

Immersion Silver Reliability / Peelable mask | 31 May, 2004

You know you'd think that wouldn't you but the only tiem I knew the vendor had changed something was when the silver started to fall off the boards!... you can tell I wasn't chuffed

Now I have to say I do prefer Dunkin's to Krispy but I can't say I've seen a Dunkins down in NZ as of yet, I'll keep lookign tho.

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#29013

Immersion Silver Reliability | 8 June, 2004

I would like to see the report from MacDermid. We have samples of ag boards in which the underside of PCB pad has been plated between the PCB laminate and pad.

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#29014

Immersion Silver Reliability | 8 June, 2004

Try: Dennis Fritz; MacDermid; Waterbury, CT; 203-575-5740 ddfritz@aol.com

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