Electronics Forum | Mon Apr 12 22:22:01 EDT 2004 | davef
Large voids are common in via in pad [seach the fine SMTnet Archives for earlier laments], especially in blind via. Observations on your via out gassing theory: * If the copper plating on your via is GT 1 thou, there will be no outgassing from the
Electronics Forum | Sat Nov 04 21:30:15 EST 2006 | Ola
Well, I can't tell you what the "glass wicking failure on PCB" are but for a standard FR4-pcb the Tg temp. or the so called glass temp. is 176 celcius degr. This means that the pcb is in between a firm and a buoyant condition. This is really a bit of
Electronics Forum | Tue Nov 07 08:01:10 EST 2006 | davef
We/ve never heard of "glass wicking failure" in regards to board fab. Boat fab, yes. Look here: http://www.boatdesign.net/forums/showthread.php?t=13321 Barrel cracking appears after thermal stress during soldering, because epoxy expands in the "z"
Electronics Forum | Thu Apr 10 12:19:19 EDT 2008 | realchunks
Frazz, Why did this get instituted in the first place? Perhaps instead of making a knee jerk reaction, your company could keep the "dangerous" areas safe with safety glasses. Like around wave or moving machinery and such. You know, put some thoug
Electronics Forum | Fri Jun 04 01:13:31 EDT 2010 | boardhouse
Hi fotis, Big difference between Cem3 & FR4 is that FR4 the glass is woven and Cem3 is sheet glass non-woven. for Multi layer product, i would not consider Cem3 due to increase chance of de-lam due to lack of weave for strength. Cem1 and Cem3 are
Electronics Forum | Tue Nov 14 03:00:14 EST 2000 | sarry
I have one suggestion why don't you align all parts and take a close look at it if you can find any misaligned component after that. IF SO, that's machine's repeatibility problem.(or mechenical problem-dirty nozzle, wrong pick up and placement height
Electronics Forum | Fri Sep 22 07:35:37 EDT 2000 | Henrik Eklund
Hello everyone out there, I have been working in the SMT process for a couple o years now, and now I'm partly responsible for the turret head component mounting process. We are about to buy new equipment and I want to do a capability study of this m
Electronics Forum | Mon Dec 06 14:56:49 EST 1999 | Russ
The best way that I have found to calculate CPk for placement machines is to buy the kit that is usually provided by the manufacturer of machine. It usually consists of a glass plate and glass components that are scaled. You simply program the mach
Electronics Forum | Tue Aug 25 16:28:11 EDT 1998 | Al Knudson
Hello, Our PWB supplier has requested that a change in the laminate material to reduce the incidence of pad lifting. The standard laminate materials (Polyclad PCL-FR-226 with a glass transition temperature of 135 C) have greater z-axis thermal expan
Electronics Forum | Thu Jun 18 21:19:17 EDT 1998 | Dave F
| I am currently using some pick & place equipment and would like to measure their cpk using a glass plate and glass "components" with vernier scales. I have seen these kits but am trying to track a supplier down in UK/Europe. | Any help is much appr
