Electronics Forum | Tue Oct 19 19:25:40 EDT 1999 | Jeff Sanchez
Carol, I think the guys are right about you stand off problem but I want to address the wrinkleing of your masking. Although I think the temps you are subjecting the board to are very high and more than likely creating problems of their own. I th
Electronics Forum | Wed Dec 18 10:10:07 EST 2002 | davef
No, sorry not on "Dave's Bookshelf". My basis is a study done at IBM. I reference it here: http://www.smtnet.com//forums/index.cfm?fuseaction=view_thread&CFApp=1&Thread_ID=4941&#Message19050 Responding differently, you're correct. If you have a
Electronics Forum | Sun Jun 30 20:00:56 EDT 2002 | redmary
the SOIC encounter solder crack after reliability test, the common process is: SMT---manual soldering---IPT(in process test)---potting---T/C(thermal cycling,only add current and voltage)---B/T and F/T (burn in and functional test). the condition is 2
Electronics Forum | Mon Jul 01 15:37:56 EDT 2002 | pjc
Possible cause can be design related- if the solder land is too small. Check w/ IPC SM-782 Solder Land Design Guide Another is board finish. I have seen problems like this with Gold finished PWBs- which creates a more brittle solder joint.Another pos
Electronics Forum | Mon Jul 01 20:42:54 EDT 2002 | davef
Comments [questions] are: * It�s strange that an uggie ol� SOIC, 50 pitch, BIG honkin� solder pad, kinda thang is failing. Sumpin aint kosher, yano? * Where is the failure occurring [ie, lead to pad, pad to board, etc]? Talk about the breadth and di
Electronics Forum | Mon May 10 11:24:33 EDT 2004 | Charly
Encounter solder ball crack after reflow, found the solder ball is out of shape after reflow, cross section view found that the solder mask opening is not good ( when we do comparason with diff. supplier substrate.) Does the solder mask shape will af
Electronics Forum | Mon May 10 16:37:01 EDT 2004 | davef
First some definitions, the two main types for solder masking near BGA pads are: 1 Pad, Non-Solder Mask Defined. In circuit board design, pads with spacing that does not allow solder (usually bumps) on the pads to contact the adjacent solder mask. [
Electronics Forum | Fri Feb 22 08:26:51 EST 2002 | davef
You are correct. The gold dissolves in the solder. The gold is meant to protect the nickel from oxidizing, so that you can solder to the nickel. Obviously that didn�t work as planned. Your background information is very sparse. Two things come
Electronics Forum | Mon Aug 09 04:15:33 EDT 1999 | Jacqueline Coia
I am having cleaning problems when processing PCB's which have TAIYO solder mask on them. After processing, hand soldering and cleaning, a sticky residue is remains, resulting in a cosmetically poor finish with tide marks etc. Other soldermasks do no
Electronics Forum | Fri Jan 29 16:17:13 EST 2021 | donnie15
The impact is low on larger pitches and pad sizes. as things get to the .4mm pitch the pad differences start affect your ball size and yields. The trace size going into the pads and the solder mask relief can cause some odd shaped pads with signif
