Electronics Forum | Thu Jul 20 10:03:30 EDT 2000 | Bob Willis
All the points raised so far are correct. Only use QFPs if rearly pushed as the yield on your process will suffer. I have wave soldered parts down to 0.020" in nitrogen with OK results but the pads and drainage pads need to be worked on. Another r
Electronics Forum | Tue Jun 27 10:51:42 EDT 2000 | Ioan
Hi Bill, there are a couple of things you should check. Most likely you have too much paste which is squashed at the insertion of the cap. - the paste height, around 7 mils should do. Too much paste will cause shorts under the cap at insertion which
Electronics Forum | Fri Jun 23 09:36:58 EDT 2000 | C.K.
Chrys: Funny that you mention that, but here at my company, our oven is blamed on almost everything: skewing, tombstoning, solder shorts, etc.... In fact, we often have to tell the supervisors, "It's not the oven because we don't turn the skewing
Electronics Forum | Fri May 26 01:50:54 EDT 2000 | Craig
We have no experience in printing glue only in dispencing for short runs. We are finding that our gluing volumes are going up and want to look at screen printing as an option. We are placing 0805 and 1206 chips, melfs, sots and ics. What are the adva
Electronics Forum | Thu Apr 13 18:41:20 EDT 2000 | Michael Parker
I too have followed all of the useful suggestions provided herein. I still found some tombstoning which was specific to a manufacturers lot. I changed the reel to another brand and the problem went away. I suspect contamination or oxidation on the co
Electronics Forum | Thu Mar 02 13:17:00 EST 2000 | Russ
Jack, a couple of questions first, 1. What pitch are these leads? 2. What are the lead footprint dimensions? 3. Orientation of component? I personally have never had much luck soldering QFPs in the wave unless they are 50 mil pitch or greater, we o
Electronics Forum | Fri Feb 25 11:13:32 EST 2000 | Russ
This probably won't help much but I find it at least a little interesting. During some experimentation recently I accidently loaded a board into the wave upside down and it had a PLCC 68 package along with other types of components that had only bee
Electronics Forum | Thu Feb 22 09:56:21 EST 2001 | blnorman
An adhesive, is an adhesive, is an adhesive. Yes most will thin when exposed to elevated temperature, but that's only for a short time. As cross-linking starts, viscosity increases. Having made countless numbers of adhesively bonded samples in the
Electronics Forum | Wed Mar 28 14:38:07 EST 2001 | CAL
Phil- A Technology you may want to give serious consideration is the Original Solutions UV-OS-1. No gold PCB's, 100% accurate,and a Money back guarantee - IMPRESSIVE! We did the studies on the Original Solutions Boards and were amazed with the techno
Electronics Forum | Thu Mar 29 08:23:02 EST 2001 | CAL
Some AOI manufacturers require you to put in a GOLD PCB. Gold PCB is a perfectly manufactured board - Correct placements, correct polarity, no solder short, a "GOOD" PCB. With the vision limitations of some AOI equipment components that have variatio
