Electronics Forum | Tue Aug 03 18:11:21 EDT 2004 | davef
Improper washing of water soluable flux residues can be a major contributor to flux residues remaining on the board surface. ;-O That you appear to be only complaining about the pathetic state of the ability of your washer to clean under BGA, it may
Electronics Forum | Tue Jul 28 16:37:24 EDT 1998 | Terry Burnette
| I think that in general it's best to deposit paste in order to increase the part standoff. This helps improve the fatigue-life of the joints by providing more strain relief. But I know from experience that it's tough to deposit paste during the r
Electronics Forum | Mon Dec 22 13:54:25 EST 2014 | proceng1
My customer made a process change to overcome a design flaw. The PCB assembly mounts in a plastic housing. The PCB mounts to the front housing via plastic stand-offs. They had to change a connector on the back side of the assembly due to long term
Electronics Forum | Fri Oct 01 14:16:15 EDT 1999 | Rick
I know there are a ton of variables that affect the overall height of a BGA after soldering to a PWB but... I'd like to know if anyone has done an analysis of (or if it's documented) as to what the pre and post reflow height dimension as measured fr
Electronics Forum | Thu Apr 05 22:27:06 EDT 2001 | davef
As a band-aid, consider running your chip wave when soldering these boards [Similar to Cals "dance with me babe" suggestion.] If the problem is as broad based as you say and the radial components have a tight fit, consider increasing the holes by a
Electronics Forum | Fri May 09 14:40:38 EDT 2014 | hegemon
I might start with the equivalent 4 or 5 mil stencil and 1:1 on the apertures. If voids are too prevalent, then I would tin the pads of the device, remove the solder, and then solder as above. You may have another hurdle, in that the resulting stan
Electronics Forum | Thu Feb 20 17:18:24 EST 2003 | davef
Give us infortmation, please. What is [are]: * Height board to board side of the interposer on the low side of uBGA * Height board to board side of the interposer on the high side of uBGA * Alloy of solder balls, no paste was used correct? * Type of
Electronics Forum | Sat Aug 25 23:01:45 EDT 2012 | ssridhar
Hello jdumont, I think the spheres are leaning as there is not enough meat under the spheres. In ceramic BGA devices there is a solder fillet which is generally a solder paste which is used to give the device some height before balling it. This heig
Electronics Forum | Tue Mar 15 13:24:44 EST 2005 | pjc
There is equipment available to clean NC residues off low standoff devices, well below 0.8mm (0.031"), from Speedline Technologies- Electrovert and Accel. See this paper under Accel: "High Reliability Underfill Performance through Proper Flip-Chip D
Electronics Forum | Fri Jun 03 14:31:33 EDT 2005 | Peter
I am working on an application requiring removing BGAs from a board coated with parylene. These BGAs have low standoff with less than 0.015" after SMT soldering. Can some comment on a reliable and consistent process to perform such rework? given tha
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