Electronics Forum | Sat Nov 25 21:26:55 EST 2006 | callckq
Dear all, I have an issue here where we found BGA crack. Understand from friend, we need to study any possiblity of our own jig or fixture cause this problem via strain gauge measurement..My question: Is there any standard @ specification establish
Electronics Forum | Wed Nov 29 01:12:12 EST 2006 | callckq
Dear Davef, Thanks for your input...The crack happen at the pad/solder ball interface..Pls review the new thread that I post just now with title called "BGA BALL CRACK AT PAD/SOLDER BALL INTERFACE" Thanks!
Electronics Forum | Mon Nov 27 08:05:50 EST 2006 | davef
There is no standard for a strain gage measurement of allowable deflection of a board or a fixture. It's possible that your fixture is causing the BGA cracking that you see. What protion of the BGA is cracking? If it is the solder connection, sear
Electronics Forum | Thu May 15 09:55:16 EDT 2014 | julianf
Tmo, Thanks for your reply. It gives good advise about how to perform tests. The type of strain gauges that I want to design are inside the PCB at various layers and I want to read the data during the press step. Do you know if these prefabricated
Electronics Forum | Wed May 14 13:31:22 EDT 2014 | taiji
You should look in to this document: IPC/JEDEC-9704A Printed Circuit Assembly Strain Gage Test Guideline Regards
Electronics Forum | Thu May 15 17:34:17 EDT 2014 | taiji
I always made tests with gauges on top or bottom surface of the PCB, before, during and after the process that we wanted to check. But I never tried to do it on internal layers of PCB. Don't know if that is possible. Regards
Electronics Forum | Fri May 16 05:17:13 EDT 2014 | julianf
Interesting. How did you connect the gauges in the press? Our press only has connections for thermocouples. But in essence, it's only a wire and an electical output. If you placed these prefabricated gauges on top and on the bottom surface, weren't
Electronics Forum | Mon May 26 03:27:00 EDT 2014 | julianf
Thanks for your reply Sarason. I'm aware now that my goals seem very ambitious and infeasible. Let me formulate my problem in an different way that might be more realistic. Is it possible to measure a DIFFERENCE in strain between top and middle la
Electronics Forum | Wed May 14 10:20:37 EDT 2014 | julianf
Hello all! For my mechanical engineering study I want to etch a strain gauge in the Wheatstone bridge configuration in a copper layer of an PCB. The goal is to measure the strain occurring in an PCB even during the press process! We can measure with
Electronics Forum | Sat May 17 10:38:49 EDT 2014 | sarason
I hate to say this but in all probability this wont work. I have built real strain gages and they depend on the change(Co-effiecent) of resistence with strain(or Stretch). since you are connecting you elements up with copper wire it will frm part of
