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Component Peel Strenght

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#44453

Component Peel Strenght | 10 October, 2006

Does anyone know of any tests or testing done on the peel strength of components to pads. I have alot of info on FAB level peel strength testing, but nothing on components themselves.

Is there any process(es) to test and insure new pastes and reflow profiles are doing their job.??

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#44458

Component Peel Strenght | 10 October, 2006

No but the owner of the last company I worked for used to think prying PLCCs off the board with a screwdriver (using an R0805 as a fulcrum and crushing it in the process) was a valid test.

"Feels pretty weak...our intermittent failure must be a process problem."

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Rob

#44464

Component Peel Strenght | 11 October, 2006

Yes, kind of - I had a look through my notes from a while back where we did a lot of work on bending strenght but the only original source I could find was reference to a paper drawn up in 1979 "Increase Terminal to Pad-Peel Strength with a Standardized Metalization System" However this was from way before the internet so I never did get my hands on it.

All of the solder companies have done work in this area in qualifying their pastes too, as have Cern & the Smart Group as part of their Lead Out campaign:

http://www.smartgroup.org/pdf/leadoutnewsletter.pdf#search=%22Component%20peel%20strength%20electronic%20solder%22

Hope that helps,

Rob.

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#44496

Component Peel Strenght | 12 October, 2006

This type of testing is only done to verify your reflow process. It is destructive testing and should not be performed on product reaching your customer. Solder is only used to provide the electrical connection from part to board. As a metal it is very weak. The added benefit from reflow is that it is strong enough to hold the component on the board. It's intent is not strength. Rob�s attachment is a study to determine the break point of various solder joints. This is destructive testing and any product used in the experiment are probably deemed scrap afterward.

As for your inquiring to a peel or push test; you should perform this test on the initial start up of the product. Run a design of experiments to push each process from it�s min to the max and then use visual inspection and IPC as your guide. You can further this experimentation by taking what you deem your worst and best looking solder joints and have them tested by an outside source such as Trace Labs (Sorry conspirators, I�m not affiliated. (Or am I? - Insert evil laugh -)). The outside lab results will confirm your visual evidence. From there you can continue to use IPC as your guide.

If you must comfort an old time gorilla and do destructive testing, you may want to think about using the results from your outside lab. Use their tensile strength as a guide. If you plan to sell the product you test, test a couple of units and send them in for tensile strength. Compare this to virgin product and see if your test is causing possible latent field failures. Also get your tools for poking and prying calibrated. Otherwise anyone with a fish scale can blow holes in your process.

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#44541

Component Peel Strenght | 16 October, 2006

Here's the paper that Rob referenced above: http://quanterion.com/RIAC/Library/Library.asp?ArgVal=45118-030

It could be that International Society for Hybrid Microelectronics [ISHM] is now International Microelectronics And Packaging Society [IMAPS] http://www.imaps.org/

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