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PCB Test Board-stress test

#30147

PCB Test Board-stress test | 20 August, 2004

We conduct temperature stress test (-40 to +100C)on our products which sits on our expensive test board. This stress test on our product shorten the life span of the test board due to the extreme temperature change. I have tried epoxy coating on the test board but it didn't help. Is there any coating or method out there that can protect the test board when they undergo stress test? Please advise

Thomas

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#30150

PCB Test Board-stress test | 21 August, 2004

First, we know of no conformal coating that will help your situation.

Second, as you say, companies recognize that stress testing of shippable products is NOT good practice, because it strips life from the product. So, your product is more expensive [has higher cost of production] and doesn't last as long.

Stress testing serves good purpose in product development and process qualification, but after those are complete, most companies use accelerated aging or no life testing of shippable products.

Third, in line with this, the "-40*C" portion of your stress screening is very brutal. How well does represent product use?

Finally, consider: * Reviewing your product screening in line with IPC-SM-785 - Guidelines For Accelerated Reliability Testing Of SM Solder Attachments. * Screening can be selected to address the specific reliability concerns [eg, solder connection strength, component construction quality, etc] that you have with your product, rather than using a broad-based meat axe approach.

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#30159

PCB Test Board-stress test | 22 August, 2004

Hi Dave,

Thanks for the input. Will certainly take your advice.

Thomas

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