Electronics Forum | Tue Oct 27 09:57:37 EST 1998 | Dave
I completely agree with what Dave said previously about the trimming process. I spent the first 6 months at my current job removing this process from our assembly floor. We had several problems with the process including: 1) "flags" from the leads
Electronics Forum | Mon Aug 12 12:05:35 EDT 2002 | russ
I use Paste for high temp balls and/or co-planarity/warpage issues. normally I only use paste flux for ball attachment. One down side to paste application is registration and volume anomalies with those little micro-stencils (for me anyway). Your
Electronics Forum | Wed Mar 02 05:14:07 EST 2005 | ABHI
Guys, Solder paste height worries all of us as we encounter the non wets after reflow. More so in fine pitch QFP's. The non wets are not always caused by solder paste height. Many other contributors. Even the pad geometry on te board can contribute t
Electronics Forum | Sat Nov 11 11:27:51 EST 2006 | Tom
Hi, "glass wicking failure" we don't know what this is, but we suspect that the reflow process could very well be the root cause for some of our pcba with micro vias failure. Micro vias pcb we know to well (we don't like them at all). There are No p
Electronics Forum | Fri Apr 13 10:13:30 EDT 2007 | Bob R.
We had a crisis with one BGA causing huge yield losses due to this defect. Nothing we could do with the profile got rid of it. Changing paste didn't get rid of it. It was the BGA warping in reflow, caused the corners to lift up when the solder was
Electronics Forum | Mon Jun 14 13:47:54 EDT 1999 | Chrys Shea
| We are a medium sized PCB assy. house manufacturing about 2000 motherboards a day. There is a major problem we are facing at the wave soldering stage, i.e. warpage of the PCB. As soon as the PCB touches the wave it warps severely from the centre
Electronics Forum | Wed Jun 16 07:34:17 EDT 1999 | Glynn Technologies and Manufacturing
| | We are a medium sized PCB assy. house manufacturing about 2000 motherboards a day. There is a major problem we are facing at the wave soldering stage, i.e. warpage of the PCB. As soon as the PCB touches the wave it warps severely from the centr
Electronics Forum | Wed Mar 18 09:03:57 EST 1998 | Earl Moon
| Problem occurs because the glass transition temp for FR4 is lower than reflow temperature. Our company wrote an article which was printed in SMT magazine some years ago | that deals with this exact subject. Best way to deal with this is to use a ce
Electronics Forum | Thu Feb 25 22:01:52 EST 1999 | Chris G.
| Read an earlier thread about using glass slugs to determine placement CPk. Can it actually be done this way? What's the procedure? Be interesting to know 'cause if it's feasible, I'd probably get myself a kit. None of us here are stat's experts
Electronics Forum | Wed Sep 19 09:34:08 EDT 2001 | jschake
Both FormFlex and Grid-lok tooling systems are marketed as compliant tooling systems. Both are able to conform to the variations of the topography on the bottomside of a substrate to provide full support during printing of 2nd side assembly. The ba
