Electronics Forum | Wed Mar 12 13:41:23 EDT 2008 | swag
We have a lead free assembly with a 128-Pin PQFP with 20 mil pitch leads. We have tried stencil aperture reductions, step-down stencils, different thickness stencils, various printer setting changes, placement pressure changes, nozzle changes, moved
Electronics Forum | Mon Apr 28 19:50:09 EDT 2008 | boardhouse
My guess is that either the board house did not cool the boards down properly coming out of the lamination oven. Typically after they come out of the heat chambers they go into a cool down chamber for x amount of time, if they cool to fast or are pu
Electronics Forum | Wed May 21 13:38:22 EDT 2008 | pjc
Solderpaste types have a big effect on print performance. Go to this link to see if the solderpaste you are using has been tested, see "Rheometric Pump Paste Tests" under MPM: http://www.speedlinetech.com/news_publications/application-notes.aspx?OnI
Electronics Forum | Wed Jun 04 00:28:27 EDT 2008 | chrispy1963
There are a couple of things that you can do. First thing to do is take a flashlight and shine it in the card edge connector of slot 2 and see if a passive component or any other part worked its way into that slot. This will cause multiple leads in
Electronics Forum | Fri Jul 25 11:29:50 EDT 2008 | wavemasterlarry
Listen, my people told me that i was being recalled to The Forum. Iam a busy man trying to erect my own company these days My fenture in China was an I opener and I feel I need to start working for myself there fore I haven't been on The Forum enou
Electronics Forum | Thu Aug 28 16:03:08 EDT 2008 | wavemasterlarry
I guess you're adding the gas to keep the fingers clean - sounds likeyou got your threads mixed up on the Forum. Any way I would suggest not doing this. Gas is pretty flammable. I have pix of one our Hollis cleaning machines going up in flames cau
Electronics Forum | Tue Sep 09 11:53:36 EDT 2008 | davef
We consider "IR-reflow soldering profile" to be the supplier's recommended reflow thermal profile that a component temination 'sees' for proper soldering, regardless of the method used to reach that temperature. When you say, "We have a lot of defec
Electronics Forum | Fri Sep 19 21:31:15 EDT 2008 | trynders
Thanks for the response guys! The parts are being sent to a local lab as we speak. I'll let you know the results when I get them. I am not sure the purpose of the copper band, but the black around the band is just shadowing from how I took the pi
Electronics Forum | Mon Sep 22 15:32:20 EDT 2008 | davef
We see this fairly often. It doesn't affect solderability. Our analysis makes us think this coloration is copper. The reason copper appears on the surface may be that heat cycles increase the thinness and porosity of the immersion silver [IAg] coatin
Electronics Forum | Sat Sep 27 10:40:24 EDT 2008 | hussman
Hello all, Just had a problem where the solder paste does not want to stick to the pad, thru the stencil. We have run this board for years with no problem, and this new lot of boards is giving us problems. I know it's a board problem because they
