Electronics Forum | Mon Mar 27 20:34:22 EST 2006 | ms
Thanks for the suggestion. The large ground pad appears as a single large pad on the component and PCB but we print a matrix of 28 small dots of paste to provide the solder for the joint. The inconsistent volume transfer can occur on any of the fo
Electronics Forum | Sat May 02 08:48:32 EDT 2009 | davef
You have a board defect. Any moisture and/or organic contaminants trapped by the solder resist during lamination may cause solder mask delamination, blistering and/or adhesion loss during subsequent soldering operations or during extended use.
Electronics Forum | Sat May 02 23:31:06 EDT 2009 | kareal
Thanks davef. The defect always occurred during UHAST reliability, but not find in reflow. The key is that there is tin diffuse to copper trace under solder mask. is it a "normal" board defect and what is the potential risk for device? thanks!
Electronics Forum | Fri May 08 04:39:32 EDT 2009 | kareal
Hi Davef, I want to explain that the tin diffusion in my project is not on solder bump/Pad region. It is on copper trace between bumps. so it is very wondering for me.
Electronics Forum | Fri May 08 09:44:23 EDT 2009 | davef
Board fabricators use solder as a resist to protect copper traces from process chemicals. Fabricators remove this resist in later processing. It's possible that board fabrication processing is the source of the tin that you see.
Electronics Forum | Tue Sep 22 23:53:01 EDT 2009 | rohitfast
Thnaks Davef..... Next time i will take for this. Actually i have tried but not found any exact answer for the same.
Electronics Forum | Tue Nov 03 18:35:28 EST 2009 | gregoryyork
was this hasl finish looks like it has been corroded from the inside of the hole wall looking at the shape of the break in plating
Electronics Forum | Thu Sep 02 05:08:12 EDT 2010 | arjan
We drilled a hole in the centre of the LGA and put the thermocouple inside, so we measure the exact temperature between PCB and device.
Electronics Forum | Wed May 05 15:31:14 EDT 2021 | edhare
0.5 to 1 micron is typically too thick and can result in gold embrittlement of the solder joint. Typical IG thickness is 0.18 microns. see https://www.semlab.com/papers/gold-embrittlement-of-solder-joints/ Ed Hare
Electronics Forum | Tue Jan 04 08:51:33 EST 2000 | g cronin
Comming into this new year I want to make sure I'm not overlooking anything in my process. I run a small contracting company, approx 20-25K PCB's per month. I am a firm beliver in finding people who know more than I do. So I am looking for anyone i
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