Electronics Forum | Wed Nov 07 21:36:17 EST 2012 | davef
Multiple process and rework thermal cycles are brutal on boards and components. Improving reliability of products through reducing thermal stress ends-up being a major driver to the interest in lower MP LF solders. Binary LF solders require the addit
Electronics Forum | Thu May 01 15:11:37 EDT 2008 | dphilbrick
CK So as I see it batch B represents a leaded process with leaded components and D is a leaded process with lead free components. Batch Components Paste B SnPb Sn62 D Lead-free Sn62 If so it is BETTER to run a lead free BGA with Sn
Electronics Forum | Thu Feb 14 09:07:43 EST 2002 | PeteC
Looking at low cost reliable Mother-Daughter board interfaces. Looking at having the Mom w/ a routed out slot, like 1.7mm wide with solder lands on the bottom side then plugging in Daughter thru Mom's slot w/ the Daughter having board edge contacts t
Electronics Forum | Mon Aug 09 07:42:52 EDT 2004 | C Lampron
Michael, We have a DRS-24 and are very happy with it. Look at the wobble in the nose cone that holds the nozzles and make sure it does not move. This will degrade your placement acuracy. The machine is very process oriented meaning that you can not
Electronics Forum | Fri Sep 17 13:24:27 EDT 2004 | Bob R.
I also agree with Russ - we use step stencils when we have to but generally try to avoid them because the print isn't as consistent as with a single thickness stencil. Many of our products are for harsh environments so we do a lot of thermal cycle a
Electronics Forum | Wed Jan 12 13:27:42 EST 2005 | carobin
The two options I see are (not including underfill): 1) Have complete conformal coating coverage of all balls with no webbing in between balls because of CTE mismatches. If all the balls are not coated we see failure in humidity testing. or 2) Sea
Electronics Forum | Thu Jul 28 09:23:48 EDT 2005 | fctassembly
300 million boards to date). I also have some reliability data for joints made with these 2 alloys wave soldered and then repaired with both. All of these results look good. The issue we see is mixing SN63 with any of the lead free alloys. Sn63 wave
Electronics Forum | Tue Jul 05 13:54:35 EDT 2005 | Sandeep
We are facing lot of problems with tombstoning in 0201 components. Ironically tomstoning in these components is not occuring while reflow but it is happening when we subject them to thermal cycling test. We have been investigating the cause and thoug
Electronics Forum | Tue Jan 31 17:14:51 EST 2006 | Chris
I would not go by any general rules at all. Test the product! Thermal cycle it and shock and vib test it. Got burned on a part that had 0.010" dia bumps. Manufacturer stated undefill was not necessary on their part due to bump size. I wanted to u
Electronics Forum | Thu Mar 02 09:23:05 EST 2006 | Bob R.
I never understood the statement "process indicator". The 7095 committee used that wording but didn't explain it. Other than really unusual cases such as champagne voiding, BGA voids are not a reliability issue. A half dozen studies have come to t
