Electronics Forum | Sun Aug 16 19:46:48 EDT 2009 | abeasia
Hi Dave F. Thanks for the suggestion, will give it a try. With Appreciation, ABE.Asia
Electronics Forum | Tue Aug 18 16:32:25 EDT 2009 | ldavis
Sergey, Try increasing the cool down time if that is a recipe option. We have witnessed the same effect on components that have rather slow cool down rates and were able to eliminate the problem by extending the cooling time.
Electronics Forum | Tue Aug 18 17:40:52 EDT 2009 | jlawson
Is the mechanics ok with the raising and lowering into the vapour ie no small movements that could be moving the part ? Most Vapour Machines have a lower and raise mechanisim so movemnt of parts can happen if not smooth, especially when coming out o
Electronics Forum | Thu Aug 20 19:07:29 EDT 2009 | smt_guy
reduce the stencil aperture to prevent tombstoning in vapor phase process. from my experience a 6 mil thick must be at least between 20 to 30 % aperture reduction for 0805's and below. cheers!
Electronics Forum | Tue Sep 22 14:18:27 EDT 2009 | davef
They could be correct about the silver if it weren't such a small portion of the connection. Study "electrochemical series of metals" to understand how metals react with each other.
Electronics Forum | Thu Oct 15 18:31:32 EDT 2009 | swag
You should take a look at these guys, also: www.ace-protech.com We have one of their machines and its been great.
Electronics Forum | Tue Nov 10 07:35:04 EST 2009 | scottp
Step 1 is to find out what kind of opens you're getting through a cross-section or die & pry. Are they head in pillow, brittle fracture at the intermetallic, bulk solder cracks, ball separation from interposer? Without some basic failure analysis a
Electronics Forum | Thu Dec 24 01:06:11 EST 2009 | isd_jwendell
You can weld (spot) to chrome. Maybe you could weld a nickel tab to the chrome part?
Electronics Forum | Mon Dec 28 14:51:06 EST 2009 | spitkis2
That's not going to work in this case. The substrate has very small pads designed for a micro BGA die. Thanks for the suggestion though.
Electronics Forum | Tue Jan 12 02:43:20 EST 2010 | graceytiu07
To cbart, The units are from our testing center. Actually I also suspected that it is a board issue. But i dont think its possible for 2 suppliers of board to have same problem. I am also checking the possibility of problem on QFP. Thanks for the s
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