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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
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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
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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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