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 | Wed Feb 05 19:43:34 EST 2003 | iman
If by the Powers Ta Be (customer/designer), you can't change the PCB design, negotiate for the PCB fab house, to block the via holes with their (green?) solder mask some customers/designers want to have via holes to be present in the PCB pad, due to
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 | Wed Apr 21 14:29:58 EDT 1999 | joe devaney
| Does anyone have any experience with soldering 50mil pitch BGA's that have a via in the pad, the size is .012 The via will be masked off on the bottom side of the board. Need to know what precautions or problems if any I might encounter. The proces
Electronics Forum | Fri May 01 07:22:56 EDT 2009 | kareal
In my project of flip chip PGA production , I found serious delamination in interface of solder mask and first layer copper trace of substrate after UHAST 96hrs( 130C, 85%RH) reliability test. The delamination are always around one type solder bump,
Electronics Forum | Tue Dec 05 22:27:05 EST 2023 | padawanlinuxero
Hello, I am experiencing issues with one of my PCB suppliers. Specifically, I am having trouble with solder shorts occurring on a SOIC8 component, and always in the same pads. Upon inspection with a microscope, I discovered that three of the pads ar
Electronics Forum | Thu Jun 24 15:44:12 EDT 1999 | Earl Moon
| | Dear guys, | | | | I have some problem on assembling micro-BGA with solder paste (63/37). The micro-BGA we assmeble is 0.75mm pitch and with 45 pin (solder bump is 96.5/3.5Ag). The stencil is a laser-cut stencil with 5 mil thickness. We are no
Electronics Forum | Thu Jun 24 13:12:15 EDT 1999 | MD Cox
| Dear guys, | | I have some problem on assembling micro-BGA with solder paste (63/37). The micro-BGA we assmeble is 0.75mm pitch and with 45 pin (solder bump is 96.5/3.5Ag). The stencil is a laser-cut stencil with 5 mil thickness. We are now usin
Electronics Forum | Thu Jun 06 07:28:30 EDT 2002 | cyber_wolf
It has been my experience that the only thing(s) that will ever cause this is: 1. Operators with paste on their hands. 2. Paste on the screen printer tooling. 3. Paste on the bottom of the stencil. Even very very small amounts of paste on the gold fi
Electronics Forum | Sat May 09 23:05:17 EDT 2009 | kareal
Davef, It seems the tin resist residue on copper trace is root cause of whitish layer. but it could explian why I could not detect tin on fresh unit without UHAST. I have performed X-section and EDS analysis on many fresh units,but no any tin was
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