Electronics Forum | Thu Apr 27 04:21:15 EDT 2006 | slaine
you can either use an alloy that has a higher copper content to reduce dissolution or the better option is to have a Nickel plating barrier. both have there problems. Bu remember the dissolution of copper by tin carries on at a slower rate a ambiant
Electronics Forum | Sat Sep 08 08:55:24 EDT 2007 | davef
We expect to see a copper shadow along the edge of pads when soldering boards with organic solderability protection [OSP]. IPC-A-610 has defined this as acceptable for years. During early reflow stages, the flux in paste dissolves the OSP where ther
Electronics Forum | Wed Jun 26 08:53:32 EDT 2002 | davef
We have not done a DOE on board warping. Consider: * How close the board gets to its Tg during the reflow cycle * Amount of copper on each side and the balance between the two * Thickness of the board * Overall length x width * Time at temperature
Electronics Forum | Mon Oct 03 22:12:53 EDT 2005 | davef
When we see warp and twist, we usually jump the fabricator for: * MLB construction (not homogeneous or unbalanced - too resin rich or poor) * Supplier process capabilities (lamination cycles) * Material selection (usually cheap and dirty), etc. War
Electronics Forum | Thu Nov 17 20:51:16 EST 2005 | cangly
Morning Mike, We use Pb63/Sn37, Alpha Metal alloy. Solder pot is at 250 C. The profile of board after Preheat about 100 C, Lambda Wave about 220C (use both Lambda and Chip wave), DWell time 2.1s ~ 3s. Conveyor speed 1.5 in/min. We run by bare board a
Electronics Forum | Thu Sep 30 16:28:51 EDT 2010 | 18424
Hello All, looking for some help from you guru's. I have several Enig boards with solderability problems. Components ranging from 0402's to ssop's. Using AIM W/S leaded solder paste, profile is beautiful and has been for years running the same produc
Electronics Forum | Tue Dec 28 21:51:04 EST 2004 | KEN
When using a foam fluxer: 1. Bubble size is important. What stones are you using? Ever clean them? Too large a bubble will NOT help your situation. (I forget bubble size range....check with your fluxer mfgr.) 2. Thinner will help in capilary m
Electronics Forum | Tue Aug 08 20:43:41 EDT 2000 | Dave F
Tom: So is warp or is it twist? They�re different problems, possibly with different sources!!! And possibly different solutions!!! Consultants to talk to are: Earl Moon (pod@vcn.com), Werner Engelmeyer (engelmaier@aol.com), Les Hymes (les.hymes@w
Electronics Forum | Mon Dec 31 08:51:58 EST 2001 | davef
Warp depends on: * How close the board gets to its Tg during the solder cycle (the closer you get to the Tg the worse the warp gets) * Amount of copper on each side and the balance between the two * Thickness of the board * Overall length x width * T
Electronics Forum | Mon Jun 14 14:39:12 EDT 2004 | davef
HASL Thickness: * HADCO DFM manual specifies a nominal thickness of 50-1500uin with an option for 100-1000uin * Merix DFM manual specifies 30-200uin IPC-6012, Class 1, 2, 3 do not spec a HASL thickness at all but only require that full coverage is m
