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How to test & measure capacitors/resistors shear force strength

Ortiz

#5817

How to test & measure capacitors/resistors shear force strength | 30 March, 2001

Hi, I need support on the method or applicable standard to measure the shear force strength on chip capacitors and resistors. I know the soldered joints strength is related to land desing, solder volume, pcb and component solderability, component size, etc. I know is time consuming but some of our customers have specific requierements on this issue, and as you know the customer is always right. We have made our own tests and method to determine the strength per component size, but we need some kind of industry standard to support it. Our measurement is done by placing and securing the board with the component to be tested, then with a pull/push force gage and an attachment we apply a pull force parallel to the board and to the side of the component until the component is pulled from the board. I search the Web and found EIA 186 standard applicable but I'm not sure.

Please if you can help me on this issue, Thanks much Ortiz

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#5821

How to test & measure capacitors/resistors shear force strength | 30 March, 2001

There is no test.

Beyond the issues that you mentioned that affect shear, an article published in a recent [1/01] "Journal Of Surface Mount Technology" documents that shear is also dependent on the rate of shear. You may be able to contact the authors of the article for their input on your dilemma.

What is it about your customer's end-use that makes a shear test a measure of product performance? What do they use this product for, chain saw fighting? Listen, there are times when that "customer is always right" platitude is just plain wrong. Your's is one. In those cases, you have an obligation to help your customer how misguided they are.

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Ortiz

#5823

How to test & measure capacitors/resistors shear force strength | 30 March, 2001

Maybe there's no test and I don't know where or why my customer came with that requirement (I think because in one of the board shipments he got a board were a smd resistor broke, but I think that happened because miss handling), but anyway I need some spec to support me to disregard the pull or shear force test.

Searching the Web I found 3 sites were this issue is mentioned: (Specification: Page 3) http://www.panasonic.com/industrial_oem/electronic_components/pdf/001_ec002_ecj_dne.pdf (Shear Strength of Soldered Joints) http://www.zipperling.de/News/independent_test_report.htm (End Termination Adherence: Page 3) http://www.avxcorp.com/docs/Catalogs/cgen.pdf

Thank you for reply to my question, I'm going to check the published article you mentioned. Any other information would be appreciated.

Thanks

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#5825

How to test & measure capacitors/resistors shear force strength | 31 March, 2001

Sure, researchers measure shear as an element of their material characterization process, but that does not make it an acceptance test. [Truly, this conversation is not uncommon on SMTnet. So, it would not surprise me if an enterprising something or other marketed such a machine and wrap it up with some official specish verbage.]

I understand that you are uncertain about your customer's motivation for this requirement, but isn't it reasonable to determine the basis for them so that you can develop a realistic process to meet those needs?

For instance, if inadequate packaging is the basic for this shear testing requirement, would not routine ANSI packaging specifications be more a more appropriate way of meeting the customer requirement that "no resistor or capacitor be recived broken"?

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