Electronics Forum | Mon Jun 29 13:51:29 EDT 1998 | Russ Miculich
| WHAT SHOULD THE RATIO BE OF STENCIL APERATURE TO PAD TO GET GOOD QUALITY RESULTS. BY THAT I MEAN, A MINIMM OF SOLDER BALLS, AND LITTLE TO NO BRIDGING, SHORTS, ETC.. | RIGHT NOW WE ARE USING A 1:1 RATIO, BUT ARE INVESTIGATING REDUCING THE APERATU
Electronics Forum | Mon Jun 29 13:50:48 EDT 1998 | Russ Miculich
| WHAT SHOULD THE RATIO BE OF STENCIL APERATURE TO PAD TO GET GOOD QUALITY RESULTS. BY THAT I MEAN, A MINIMM OF SOLDER BALLS, AND LITTLE TO NO BRIDGING, SHORTS, ETC.. | RIGHT NOW WE ARE USING A 1:1 RATIO, BUT ARE INVESTIGATING REDUCING THE APERATU
Electronics Forum | Fri Apr 03 08:22:36 EST 1998 | Scott Cook
| At this moment in time we are using water soluble solder paste on our PCBs these are cleaned using water only, agitated with ultrasonics. After drying a white/grey residue is left around solder joints. Reflow profile is fine and a reliable wash pro
Electronics Forum | Mon Mar 30 11:39:46 EDT 2009 | rgduval
Is this a sample board that you ran without components? If so, I'd get it back to your board house, and ask them to explain to you what's happening. We never did get to a satisfactory root cause on our issue (at least, satisfactory to me). It seem
Electronics Forum | Wed Jan 17 03:35:07 EST 2001 | Arul
We have few failures similar to the discussion in this thread, on a 50 Mil pitch, 30 Mil mill Ball PBGA. Would like to understand the mechanism of the BGA reflow process bit more. Appreciate your response to the following. 1.We sheared few solder ba
Electronics Forum | Wed Feb 03 22:47:48 EST 1999 | Chris G.
| Hi! | | Does anyone know any roadmaps for board plating materials. Especially I'm interested in finishes, which are plated onto copper. | | Teemu M�kiniemi | Teemu, For some time now, as I am sure you are aware, the PCB industry has been tryi
Electronics Forum | Thu Dec 24 01:38:36 EST 1998 | Chris Grendler
I need advice on a pad design which several other engineers whom I work with would like to try. I think it is an utterly crazy but I can't seem to convince them differently. My current 0402 chip pad sizes on alumina and FR4 substrates are .022"X.
Electronics Forum | Tue Apr 14 09:38:07 EDT 1998 | Earl Moon
| We are having some difficulty soldering a 240 pin Altera device. We use Alpha WS-609, a very generic profile for that solder paste, and a 6 mil stencil with laser cut apertures (1:1 ratio). This is a 20 mil pitch device (aperture size is 10 mils X
Electronics Forum | Thu Jan 08 15:03:40 EST 2004 | dwzeek
We have an ongoing problem with our QFP144 packages soldering. It has not received much attention until late due to some customer failures. Most of the failures would show up in ESS testing and be repaired. The failure rate is about 2 in 1000 parts f
Electronics Forum | Thu Sep 16 18:07:16 EDT 1999 | Earl Moon
| We have some SMT components with gold plated leads. They're actually LCC led packages. A good solder alloy to use would be Indium / Lead to reduce tin dissolution into the gold and avoid the resultant brittle intermetallic compound. However, a reco
