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How conduct solderability of Old date code parts - more than 5 year old parts

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#83920

Best practice to validate the old - more than 5 year old parts | 11 December, 2019

Dear Friends,

Need your valuable feedback on how to identify the component is ok or not for manufacturing.

Issue : We have parts which are more than 5 years old.And management want us to qualify this parts for production.

We presently use below method. 1. Dip and look IPC/JEDEC J–STD-002B Tin/Lead solder – solder pot temperature =245+/-10Deg 2. Dip and look IPC/JEDEC J-STD-002B Tin/Silver/Copper solder – solder pot temperature = 265+/-10 Deg

Usually we do for 3 to 4 components. Which will be ok in dip test.

But while running production in reflow soldering we face open solder , pin hole defects in such parts.

What is the best practice to validate the old date code parts.

please suggest.

Regards, Ameen

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#83942

Best practice to validate the old - more than 5 year old parts | 12 December, 2019

Hello! 1) You can try to use solderbility tester (https://www.gen3systems.com/solderability-testing-must). 2) You can try to find more agressive solder paste.

Some time ago we had the same problem. We gave some samples to our friends from another company and they sent us graphics of solderbility (force/ time). But our owner said - need to use, so i found more agressive (but no-clean) solder paste. It helped but not solved problem totally.

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#83943

Best practice to validate the old - more than 5 year old parts | 12 December, 2019

When I hear "pinholes" in solder connections, I think of two sources, depending on the situation, which can be either:

+ Entrapped air and process chemicals develop during reflow soldering to cause the pinholes in and around the intermetallic layer

+ In wave soldering, pinholes are usually the result of moisture outgassing through plating in hole walls that is too thin

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#83944

Best practice to validate the old - more than 5 year old parts | 12 December, 2019

You proved that the standard solderability test of components may be effective for assessing aged components.

Curious Minds

Can you get the authorization to use a more aggressive flux? Will that flux solve the problem? What's it going to cost to qualify that flux in your process? Given your rework rate are you better off scrapping these parts and buying new parts?

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#83952

Best practice to validate the old - more than 5 year old parts | 13 December, 2019

Dear Alex,

thanks for the machine link. And valuable feedback.

We cant change the solder paste. Its a for defense and aerospace projects.

Customer won't agree on it . We have major issue in ROL0 Flux classified solder paste.

cannot go for aggressive flux chemistry.

So need a good method to hold the old date code parts at starting stage itself.

Regards, Ameen

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#83953

Best practice to validate the old - more than 5 year old parts | 13 December, 2019

Dear Dave,

We cant change the solder paste. Its a for defense and aerospace projects.

Customer won't agree on it . We have major issue in ROL0 Flux classified solder paste.

cannot go for aggressive flux chemistry.

So need a good method to hold the old date code parts at starting stage itself.

Need a good method for SMT parts. Especially passive components

Regards, Ameen

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#83955

Best practice to validate the old - more than 5 year old parts | 13 December, 2019

I'm not conversant in the topic, but I know suppliers to the government are concerned as you are. I have attended sessions on the topic at technical conferences. The topic that you want to search for is long-term storage protocols for electronic components.

By receiving this information, you promise to return and help us learn more about the topic.

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SMTA-Norah

#83957

Best practice to validate the old - more than 5 year old parts | 13 December, 2019

are the parts dry? How have they been stored? Would baking them out be useful?

This message was posted via the Electronics Forum @ SMTASMTA

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#83959

Best practice to validate the old - more than 5 year old parts | 16 December, 2019

Sure dave,

Thanks

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#83960

Best practice to validate the old - more than 5 year old parts | 16 December, 2019

Hi Norah,

Thanks..

Components are stored in controlled environment of 20 to 25 deg c & 40 to 60 % humidity.

Baking wont be feasible for many parts. Mainly for passive parts in tape and reel. 0402, 0603 & 0805 packages.

Cold baking is not feasible , we have capacity constraints.

We have authority to do solderability test.

And based on the test result. We can approve or scrap the old parts.

So was looking for effective techniques used around the world for qualifying or use old parts.

Regards, Ameen

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SMTA-Norah

#83968

Best practice to validate the old - more than 5 year old parts | 16 December, 2019

Passives are at least fairly simple, generally either they solder or they don't, testing with paste stenciled on to glass slides is one variation and a hot solder dip is another. The glass slide is nice because it's closer to the end use scenario. However hot solder dipping the entire lot to improve solder-ability is a thing sometimes done as well.

60% relative humidity is higher than I like so you might have more variables to chase with the ICs. Things like trapped moisture venting into the joint that will only show up in situ. Best of luck.

This message was posted via the Electronics Forum @ SMTASMTA

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#83971

Best practice to validate the old - more than 5 year old parts | 16 December, 2019

Thank you for the valuable suggestions.

Regards, Ameen

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#83973

Best practice to validate the old - more than 5 year old parts | 17 December, 2019

We had a customer who used XRF to determine the thickness of the "tinned" layer of components - sort of what is briefly mentioned in Bob Klenke's SMTA paper -

http://www.circuitinsight.com/pdf/Solderability_Testing_Protocols_Component_Re-Tinning_Methods_21st_Century_smta.pdf

They did a wetting balance and XRF every 6 months on all parts.

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#83976

Best practice to validate the old - more than 5 year old parts | 18 December, 2019

Thanks Rob.

Regards, Ameen

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