Electronics Forum | Tue Feb 29 21:53:46 EST 2000 | Kelvin Chow
Dear Robert, On PBGA assembly, BGA sphere shrinkage number depends to the following factors, a. BGA Sphere size (before reflow) b. Solder mask opening diameter As far as I know, no formular has been established yet. Most of my friends just collect
Electronics Forum | Wed Aug 30 00:16:15 EDT 2000 | Craig
We are reflowing ceramic resonators and are finding their tops falling/popping off when handling the pcbs during final assy. The epoxy seems to be coming off the components base and adherring to the lid. The components are "RFM resonators", case type
Electronics Forum | Thu Apr 20 21:45:10 EDT 2000 | Dave F
Wister: Oooo, I understand now what you mean by "an open." Sorry, I was (am) a bit dense. Your hypothesis is reasonable. On the other hand, have you looked at the traditional causes of tomb stoning also? For a defect to be a "tomb stone," it doe
Electronics Forum | Tue Feb 29 21:53:46 EST 2000 | Kelvin Chow
Dear Robert, On PBGA assembly, BGA sphere shrinkage number depends to the following factors, a. BGA Sphere size (before reflow) b. Solder mask opening diameter As far as I know, no formular has been established yet. Most of my friends just collect
Electronics Forum | Thu Jun 28 22:42:13 EDT 2001 | davef
I�m with Stefan � no booze, drugs, or chewing tobacco in the shop!!! [I�d like to ban facial make-up, but am still limping from the last time I tried.] Stefan, how are you going to get the P&P manufacturers to agree on a common nozzle design, when
Electronics Forum | Thu Nov 04 10:07:32 EST 1999 | Wolfgang Busko
Sometimes when using a new pot of paste you get one which isn�t good at all without any noticable appearance at first sight. You might try a new one. Despite the fact that you run the same profile as usual a defect of the oven of any kind unnoticed c
Electronics Forum | Wed Sep 29 07:28:04 EDT 1999 | Wolfgang Busko
3�C/min) or maximum temperature (~240-250�C)." For the correct handling of moisture sensitive devices and prebaking advices see IPC-SM-786A or newer publikations. I encountered the following: A tray of sample BGAs was send to me proper packed and se
Electronics Forum | Mon Jun 21 15:27:00 EDT 1999 | Tony
| I dug through my big box of office crap and found the disk with my technical papers. I posted the one on process control in the SMTNet library. It covers a lot of ground on what causes defects in the wave (too much or too little of something), an
Electronics Forum | Fri May 21 15:50:41 EDT 1999 | John Thorup
We are running a number of boards with 8-10 25 mil PQFPs on board. Our process is mature with at least 3 years experiance and statistically few opens on the QFPs. Our beloved purchasing department has chased the almighty $ and changed FAB vendors
Electronics Forum | Wed May 05 20:22:33 EDT 1999 | ADRIANO FERNANDES
I would like to know if someone aleady have problems with Ceramic Capacitors SMD in In-Circuit Test (see below)and how did you solve this problems ? PROBLEMS 1 - Only one kind of capacitor (2n2F), of all capacitors on board, sometimes are open, and
