Electronics Forum | Thu May 31 19:45:47 EDT 2007 | diesel_1t
We place a QFP 256 leads 20 mil pitch, had a lot of troubles with shifted components and solderability issues. solderability is not a problem anymore; we solved with a ramp-to-spike profile with .9�C/s 'til 183� then spike to about 118�C, TAL ~60s. W
Electronics Forum | Fri Jun 01 17:31:17 EDT 2007 | gsala
Thanks Patrick, also IPC-HDBK-001 explains even better then IPC-J-STD-004, but unfortunately not yet infos about flux for L-F soldering.That's why I am trying to get some infos more from experienced people. Some L-F (SAC or SACX) cored wires vendor
Electronics Forum | Fri Jun 08 08:26:14 EDT 2007 | davef
Testing for solder mask cure: Search the fine SMTnet Archives, for instance: http://www.smtnet.com/forums/Index.cfm?CFApp=1&Message_ID=15726 Residue after wave: Water in your wave soldering flux may cause your NC flux residue to go white. Indium W
Electronics Forum | Wed Jun 13 12:19:25 EDT 2007 | allwave
Brian, We had similar problem in our inline wash machine time ago. We checked everythin on equipment (filters, DI water purity, sprayers angle, etc). To make the long story short, we found out that the problem was caused by a new solder paste. This s
Electronics Forum | Thu Jul 05 10:11:19 EDT 2007 | ck_the_flip
The variables to study: * Dwell Time * Contact Length * Conveyor Speed * Parallelism * Top-side Substrate Temperature Before wave * Solder Pot temperature All of these variables are inter-related (ie changing one variable will affect another)
Electronics Forum | Thu Jul 12 16:14:20 EDT 2007 | realchunks
Hi Scott, Hard to tell what kind of problem you really have. I guess you need to describe your process first. What kind of process are you using. Wave solder, reflow solder, etc.. What kind of flux are you using to solder with? Vaccum? What ar
Electronics Forum | Thu Jul 12 16:57:46 EDT 2007 | jmelson
Canyou see this contamination? Is it solder beads, flux or something else? If flux, then more cleaning should help, either more time, more cycles through the cleaner, etc. If it is solder beads that are not melted to the rest of the solder, then s
Electronics Forum | Fri Jul 13 17:00:34 EDT 2007 | jmelson
Oh, sure, on fine-pitch parts you need a microscope or at least a good magnifier. But, OK, you have some kind of contamination. Solder is one thing, but where are these stainless, aluminum and copper particles coming from? Stainless makes me think
Electronics Forum | Fri Jul 13 10:57:04 EDT 2007 | dboudreau
Dear all, we are using the lead-free SN100C solder alloy for wave soldering. We are experiencing wetting problems each time we have to solder a thick board or a board with a large ground plane.I think that maybe we are not using the right flux. I w
Electronics Forum | Wed Jul 25 10:57:08 EDT 2007 | cecil
Our board layout folks are currently designing a PWB using a 132 QFN. The component is .5mm pitch with .35mm square pads. The component manufacturer recommends the following footprint: .4mm square land .3mm square solder resist 1.why do they spec
