Electronics Forum | Wed Feb 03 18:32:07 EST 1999 | Earl Moon
| I'd like to find some technical papers on the reliability of reworked BGAs. If you know of any, please let me know. | | I have a concern about this because our current rework process does not apply solder paste to the pads prior to placing the pa
Electronics Forum | Thu Feb 04 15:44:04 EST 1999 | Michael Allen
Actually, solder paste adds about 12% to the joint volume for PBGAs, or about 31% for MicroBGAs -- assuming standard (recommended) pad sizes and stencil thicknesses, and paste with 90% metal content (50% metal by volume). | | I'd like to find some t
Electronics Forum | Mon Oct 15 10:51:49 EDT 2001 | davef
On over printing, the general issues are: * Paste deposits being so large that when reflowing, collapse onto many, rather than a single solder mass. * Paste expanding during heating and being close to other solder deposits and bridging [as you say].
Electronics Forum | Mon Oct 14 17:59:45 EDT 2002 | russ
When I used the micro-stencils, We purchased the holder from the stencil manufacturer. As far as design we used 5mil stencils for uBGAs,6-7 mil for larger 63/37 balls, and 8 mil for CBGAs. Aperture openings used were slightly smaller than what we wo
Electronics Forum | Wed Nov 01 07:32:33 EST 2006 | davef
What you have run up against is the unfortunate consequence of the transition period from Sn-Pb to Pb-free. In the past 2-3 years there have been several studies highlighting the differences in reliability between mixed metal systems, Sn/Pb, and SAC
Electronics Forum | Fri May 07 17:02:01 EDT 1999 | Earl Moon
| On 1.27mm (0.050 inches) Standard Ball Grid Array's. | The ball size diameter starts at approximately 0.025 inches. | | If the ball size decreases to 0.012 inches (due to the solder flowing down a via) is the solder connection reliable? | | This
Electronics Forum | Thu May 13 18:36:55 EDT 1999 | Andrew Wulff
| | On 1.27mm (0.050 inches) Standard Ball Grid Array's. | | The ball size diameter starts at approximately 0.025 inches. | | | | If the ball size decreases to 0.012 inches (due to the solder flowing down a via) is the solder connection reliable? |
Electronics Forum | Thu Feb 04 18:45:56 EST 1999 | Earl Moon
| Actually, solder paste adds about 12% to the joint volume for PBGAs, or about 31% for MicroBGAs -- assuming standard (recommended) pad sizes and stencil thicknesses, and paste with 90% metal content (50% metal by volume). Michael, In the "real wo
