Electronics Forum | Sat Jun 18 08:03:58 EDT 2005 | davef
kenscj: Responding to your points of interest: * On the smoothness of BGA solder balls causing solder ball misalign, void, solder short after reflow: We expect the solder balls to be smooth and have no sharp irregularities. We can't recall attribut
Electronics Forum | Thu Aug 25 10:17:48 EDT 2005 | davef
Send the pic to dave5252 at hotmail.com [you can't send pic through the SMTnet email thing] For more on via plugging, tenting, capping ... look here: http://www.merix.com/technology.php?section=processes&page=pdf/Via_Fill_Plug.pdf Something, a voi
Electronics Forum | Wed Sep 07 10:41:24 EDT 2005 | D.B. Cooper
We've seen the same thing - leads of QFPs not as strong as we'd like them to be. In the past 4 years no problem, this Spring they start failing. Touch a solder iron to it and it solders fine. After crunching some data, we found that both QFPs fail
Electronics Forum | Mon Sep 05 01:38:12 EDT 2005 | plcc
I hv a PCB (mtrl is RF35). After going thru' reflow, we found yellowish stain on the solder pad (solder mask). It looks like burn-marks. The reflow temp use is 245oC. We tried running bare pcb under 220oC, there's minimum stain found (acceptable),how
Electronics Forum | Thu Sep 15 03:07:15 EDT 2005 | LeeHoMa
hi All, I am new to this forum and got a technical problem as below. Please see if anybody can help to solve it: I am currently producing one PCB board with 2 side SMD parts and all AI component in 1 side. I try to have both side SMD part soldered(
Electronics Forum | Wed Jan 04 15:10:27 EST 2006 | grantp
Hi, That's the main problem. I quickly checked out the motorola document, and thanks for posting that, but the main reason for failure seems to be that the ball is not touching the solder pad. I wonder what kind of ball size tolerance they had on th
Electronics Forum | Tue Dec 13 14:55:12 EST 2005 | muse95
Your response is from the point of view of using a Bismuth solder with Pb plated leads. Samir's point of view is from Bismuth in the plating on the leads being used with a Pb solder. There is a very large difference in the amount of Bi that will en
Electronics Forum | Thu Jan 19 06:25:42 EST 2006 | bwet
There are several life studies (see for example http://www.solder.net/stencilquik/articles.asp) which point to higher reliability of reworked BGAs using solder paste vs flux. The theory on the mechanisms which allow this to happen are as follows: 1
Electronics Forum | Tue Feb 14 22:48:06 EST 2006 | Cal Kolokoy
That is a tough situation and a tough answer for us SMT forum participants. After all, most of us are in the business of placing and soldering components to circuit boards, and you know the saying; you can't make solder joints with an unsolderable su
Electronics Forum | Mon Mar 13 10:45:44 EST 2006 | muse95
The original issue was Co. does not need to go Pbfree, but some BGA's they use are only available Pbfree. They don't want to throw away Pb BGA stock, so some boards might have a combination of both Pb and Pbfree BGAs. The question basically was Shou
