Electronics Forum | Wed Oct 16 01:28:45 EDT 2002 | redmary
during the failure analysis, how to etch the tin,nickle,and copper?
Electronics Forum | Thu Oct 17 23:25:53 EDT 2002 | redmary
We generally etch the copper back slightly using a 50/50 mix of 3% Hydrogen Peroxide and laboratory grade Ammonium Hydroxide. Swab for about 5 seconds, then rinse. and etch the tin in the solder to further delineate the intermetallic layer that shou
Electronics Forum | Thu Nov 16 06:13:16 EST 2000 | Adam Seychell
I am currently building a home PCB etching tank based on the ammonia/ammonium sulfate chemistry. The etching system consists of a etching tank, and an electrolytic copper recovery tank. The result is a infinitely replenishable etching system without
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 | 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 | 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 | 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
Electronics Forum | Mon May 26 04:39:49 EDT 2014 | sarason
Damn near impossible. You need to see a real change in the difference between the 2 elements you are reading. So to give yourself any hope run 2 long traces one top one bottom up the length of the board. Then compare to 2 wriggly traces at one end (o
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