Electronics Forum | Thu Oct 26 17:42:29 EDT 2000 | Philip A. Reyes
Hi Mr Paul! Thanks for answering my previous questions. Hope you can still accommodate my other queries. This is about the acceptable criteria of PBGA defects after reflow soldering. 1.What is the allowable (min and max. ball misregistration / misal
Electronics Forum | Sat Aug 04 12:03:25 EDT 2001 | johnw
The reason we're putting the epoxy in at the last process is two fold really. 1. as you suggest putting the componnd down prior to placement is going to cause issues around the placement of the device. But more importantly 2. the material speced by
Electronics Forum | Mon Feb 07 19:49:50 EST 2000 | Tony Di Mauro
Jose, I have seen this defect before. We called it re-reflow. We found the part was originally attached at SMT. Later on after seeing a heat cycle at the wave machine the leads would de-attach causing an open at In-Circuit Test. Resolution was t
Electronics Forum | Wed Jan 19 23:24:03 EST 2000 | armin
Hi, We have a couple of pcb's with PTH Crystal. We are looking for a spacer to be placed between the metallic body of the crystal and the via pad/land as they tend to short if wave soldered without a spacer. The spacer we are looking for is somethin
Electronics Forum | Fri Dec 10 12:40:44 EST 1999 | Brian W.
It sounds like the process is very labor intensive, and all the verification is done after the parts are soldered. Assuming you are hand placing the components: 1 - Contact Systems semi-automatic placement machine. It show polarity when placing, so
Electronics Forum | Fri Dec 10 06:06:54 EST 1999 | Wolfgang Busko
Hi Glen, looks like flux or solder mask problem. In your first mail you said that only some boards show these symptoms and others not. First I would check on the differences between those Boards, manufactorer, solder resist, contamination. If that d
Electronics Forum | Wed Oct 20 10:49:04 EDT 1999 | Brian
Hi! Stu's method is a half-truth. What it measures is the aggregate of all volatile material with a significant vapour pressure at the baking temperature, not just H2O. Short of very complex methods, it could be complemented by a comparitive measur
Electronics Forum | Tue Oct 19 10:53:14 EDT 1999 | Carol Zhang
Hi, I tried to use high temperature solder (540 - 570F)to connect four spacers on the board. The solder mask around the spacers wrinkled a lot.I can even see a few bulbs around it. I use hot plate and solder rings. After hot plate is heated to appr
Electronics Forum | Thu Sep 02 10:35:46 EDT 1999 | Gian.D
We are assembling double side pcs reflowing (smt) on top and by wave on bottom. After first step (smt) we dispense glue on the bottom side putting one or two glue dots under small components and we cure in oven before wave. After wave soldering we f
Electronics Forum | Tue Aug 24 09:13:17 EDT 1999 | Earl Moon
Again, I really appreciate the valuable input you all provided. Got my Air-Vac SRM4 machine Friday afternoon. Stored it safely in my cube over the week-end for safe keeping. Tried to find 220V single phase next to air with no luck yesterday. Electric
