Electronics Forum | Wed Nov 06 19:03:33 EST 2002 | broncos
If you are certain that reflow process is good, I would suggest starting checking the following: 1. Check to see if leads / pads are contaminated or oxidized. However, this usually results poor solder quality throughout the board. 2. Check the amou
Electronics Forum | Tue Feb 03 06:52:45 EST 2004 | paul_bmc
About 2 years ago our company tried to go with a post reflow AOI inspection. This AOI was suppose to be able to inspect to a level class 3 product. **It is impossible** You cannot inspect for a heel fillet and inspecting for poor wetting is a very
Electronics Forum | Tue Jan 15 06:05:37 EST 2002 | Romain
Dear all We have since few weeks problems with BGA solder joint integrity on ENIG finish. Under relatively very flexible of the FR4, the joint breaks between ball and PWB. When we take off the BGA for analysis, some of the pads seem very flat, totaly
Electronics Forum | Tue Jan 15 12:20:16 EST 2002 | cfraser
This sounds like it could possibly be a case of Black Pad. We have had a few issuses with this in the past as well. Who the PWB vendor? I also recommend searching the archives and doing some solder samples with nonpopulated boards
Electronics Forum | Fri Feb 01 11:58:28 EST 2002 | Romain
the PCB vendor is Multek in germany he made some measures about P content in Ni layer. What is the normal level of Phosporous and what is the upper limit ? thanks Romain
Electronics Forum | Tue Jan 15 09:42:40 EST 2002 | davef
Here's two choices. 1 Before accepting a lot of boards from your supplier: * Print some paste on a board * Reflow the paste * Inspect the quality of the solder connection * Make a decision on accpting the board based on that observation. 2 Have yo
Electronics Forum | Fri Mar 19 10:06:22 EDT 2010 | karlo
Rework is typically done by heating the BGA to 170-180C to first scrape off the fillet. Then, heat to above reflow, and lift the BGA. Then, collapse the solder with heat and flux. Then, back down at 170-180C, scrape off the underfill from the boar
Electronics Forum | Wed Oct 02 15:08:37 EDT 2002 | Eric
See Fiske first line. I'd bet You are bending or catching the assembly in the ICT. How many probes at 8OZ each? do you use on that ICT? 800 probes = 400lbs. See "Flexure induced failure of BGA solder joints" by Compaq Houston TX
Electronics Forum | Thu Sep 12 10:45:29 EDT 2002 | pbarton
We have used a laser cut stencil 0.15mm (0.006") thick with 0.3mm (0.012") square apertures radiused in the corners 0.06mm (0.0025") to aid paste release. This approach with the (type 3) paste we use has proven successful on thousands of devices plac
Electronics Forum | Tue Jul 14 18:42:41 EDT 2009 | anndi
1smtdude, I interested in your explaination of > re-work an underfill part. You mention the > material can be heated to a plastic state to > become vicious... do you know usually what range > is the temperate? (guess it can depend on the > type
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