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July 1999

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Subject:
From:
David D Hillman <[log in to unmask]>
Reply To:
TechNet E-Mail Forum.
Date:
Wed, 7 Jul 1999 08:10:35 -0500
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Hi Jim! Here are some responses to your questions:

1) Is there a minimum period of time after component manufacture that
> solderability testing is not necessary?  It seems strange that component
> manufacturers are required to meet functional and performance
requirements but
> not solderability.

** The simple answer is nothing last forever! But if a component
manufacturer fabricates a component with a quality surface finish it should
retain solderability for a very long time period. I have seen components
that are 20 years old that have retain good solderability. Good
solderability is a function of correct material selection and surface
finish process control. Your solderability requirements should be viewed in
terms of how long of shelf life do you need - if you are going to solder
the components a week after you get them then a 5 year shelf life
expectation is costly and extravagant


> 2) Is J-STD-002 Category 1 (no Steam Ageing Requirement) the industry
norm?

** The component manufacturer's I deal with meet the JSTD2A stream age
requirement


> 3) What is the least expensive way to meet solderability test
requirements?

** Don't test at all. The second least expensive way would be to use a SPC
sampling plan with reaction limits. Just remember - you get what you pay
for.

> 4) What are acceptable sampling criteria, especially for reeled
components?

** I would suggest using the JSTD-001 philosophy and/or IPC-PC-90
guidelines

> 5) Would it be reasonable to request J-STD-001B requirements 5.2, 5.4 be
> tailored to restrict the solderability requirements to apply to parts
> manufactured more than 2 years prior to use but excluding newer parts
> on the basis that we are consistently producing Class 2 product and
> that our date code policy requires use of components within two years of
> manufacture.

** Solderability is not just a Class 1 or 2 or 3 concern! Good
solderability is the basis for the formation of properly wetted solder
joints. Having good solderability should be a requirement for the overall
soldering process. Your suggested logistics of addressing solderability
could work if you and your component fabricators have a close working
relationship.

Good Luck.

Dave Hillman
ANSIJ-STD-002 CoChair
[log in to unmask]






Jim Wiggers <[log in to unmask]> on 07/03/99 10:36:41 PM

Please respond to "TechNet E-Mail Forum." <[log in to unmask]>; Please respond
      to Jim Wiggers <[log in to unmask]>

To:   [log in to unmask]
cc:
Subject:  [TN] "Solderability Testing" In Use




> In an effort to improve PWA reliability and meet the requirements of a
> particular customer, we adopted J-STD-001 Class 2 as our default assembly
> requirement.  This imposes J-STD-002 for solderability testing.
>
> We view the requirements as somewhat intensive and wonder what standard
> industry practice is.
>
> If you have military or aviation based experience I would really
appreciate
> hearing from you.
>
> My questions are:
> 1) Is there a minimum period of time after component manufacture that
> solderability testing is not necessary?  It seems strange that component
> manufacturers are required to meet functional and performance
requirements but
> not solderability.
> 2) Is J-STD-002 Category 1 (no Steam Ageing Requirement) the industry
norm?
> 3) What is the least expensive way to meet solderability test
requirements?
> 4) What are acceptable sampling criteria, especially for reeled
components?
> 5) Would it be reasonable to request J-STD-001B requirements 5.2, 5.4 be
> tailored to restrict the solderability requirements to apply to parts
> manufactured more than 2 years prior to use but excluding newer parts
> *     on the basis that we are consistently producing Class 2 product and
> *     that our date code policy requires use of components within two
years of
> manufacture.
>
> Note:  Most of our component purchases are for pre-bent and pre-tinned
> commercial components.
>
> Your comments and recommendations are most appreciated.
>
> Jim Wiggers

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