Electronics Forum | Tue Feb 19 22:57:38 EST 2008 | davef
Duno. What's the diameter of: * Finished connector lead * Finished through hole We reckon: Lead size plus ~0.25mm [0.010"] is normal.
Electronics Forum | Tue Feb 19 23:00:29 EST 2008 | amarpreet41
Connector pin - 10.83 mils Hole dia - 27 - 33 mils. We are trying to find the optimam level for hole dia.
Electronics Forum | Wed Feb 20 09:05:38 EST 2008 | tonyamenson
We had a similar problem with lead-free through-hole components. We baked those baords to remove the residual moisture and everything went to 100% pass - defect was gone. Couldnt hurt to try a sample run while you decide if the PCB holes need to be
Electronics Forum | Wed Feb 20 09:29:19 EST 2008 | mun4o
ni, I had similar problem too.I bake PCB in SW mashine - about 8h ,T=90 C.Problem is in the base material of PCB - there are moisture in the material.After my complaint to PCB factory , they change material and the problem disappear.
Electronics Forum | Mon Jan 21 18:58:21 EST 2008 | davef
We have read papers espousing using xray, but have never seen such a thing. It seems the contrast provided in the xray images is insufficient for analysis of the underfill.
Electronics Forum | Tue Jan 22 07:50:20 EST 2008 | rayjr1491
Thanks Dave, I spoke with a Loctite application person yesterday and the mentioned SAM as well. best regards, Ray
Electronics Forum | Tue Jan 22 09:48:09 EST 2008 | davef
Here's an article on flux / underfill compatibility http://ap.pennnet.com/articles/print_toc.cfm?p=36&v=16&i=6
Electronics Forum | Wed May 07 09:21:46 EDT 2003 | davef
Here's some papers: * �Voiding Of Lead-Free Soldering At Microvia�; Dr. Hyoryoon Jo, B. Nieman, and Dr. N.C. Lee Indium Corporation of America; SMTA International; 09/22/2002 * �Solder Joint Formation With Sn-Ag-Cu And Sn-Pb Solder Balls And Pastes�;
Electronics Forum | Sat Mar 27 08:15:02 EST 2004 | davef
Via in pad is a designer's dream and an assembler's nightmare. Search the fine SMTnet Archives for previous discussions to get started. VIP, via-in-pad, or whatever tend to promote voiding within the via and certainly partially starved solder conne
Electronics Forum | Wed Mar 14 13:16:54 EDT 2007 | Shane
I have a customer that designed a fine pitch BGA into a board, and has put small vias in the middle of each pad on the PCB. Anyone have any ideas on how I can prevent the solder from the BGA from flowing through the vias and causing voids or no cont
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