Electronics Forum | Wed Oct 18 16:41:35 EDT 2000 | Dave F
It's unrealistic to think that two materials with the following disperant properties would have the same reflow profile. From http://www.norplex.com/Carrier.htm Physical Properties / NEMA FR-4 / NEMA CEM-1 Glass transition temperature �C / 130 / 10
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 | Fri Oct 05 09:15:23 EDT 2001 | Ben Bierlein
It is a PCB material that has a woven glass / epoxy internal core and glass veil surface. It is in between the paper materials (FR1,FR2 and CEM1) and FR-4 as far as strength and cost. It is available in HiCTI material for high power applications.
Electronics Forum | Mon Feb 16 11:30:10 EST 2015 | clydestrum
Could anyone point me in the direction of finding out how much strength an SMT pad has in relation to being pulled away from the substrate/laminate? We are in process of trying to build a 6mil thick board and want to know if a chip can be placed onto
Electronics Forum | Fri Jan 21 14:51:08 EST 2000 | Dave F
Mike: I�d hate to see you making design decisions, based solely on the discussion here, but that this would be an impetus to consult IPC-D-279, "Design Guidelines ... " and take a course on designing reliable boards. Werner Engelmaier (Engelmaier
Electronics Forum | Tue Nov 19 02:59:24 EST 2002 | yngwie
Hi Experts out there, pls help me with the following matters. How important is the bare PCB baking ? What is the temperature for baking @ what RH ? What would be the impact for the ENTEK finished board should the baking is really necessary ? For t
Electronics Forum | Wed Nov 20 16:53:18 EST 2002 | davef
Q1: How important is the bare PCB baking ? A1: Baking boards is a non-value added activity. Q2: What is the temperature for baking @ what RH ? A2: Search the fine SMTnet Arcives for bake recipes. Q3: What would be the impact for the ENTEK finishe
Electronics Forum | Thu Dec 30 21:22:12 EST 1999 | Jim
Mike, Thanks for the reply. It's not really a matter of slope. It is the long term thermomechanical fatigue that the solder joint undergoes as a result of repeated severe temperature swings, while the product is in use. Non-leaded parts are suscep
Electronics Forum | Wed Apr 21 12:03:59 EDT 1999 | Michael N.
I'm having problems with trying to get a good solder joint using a Ceramic PCB. We are using AMTECH hi-temp solder (ws-486 96.5/3.5ag). My profile looks great and I used the recommended profile from Amtech with a few adjustments. My max temp is about
Electronics Forum | Fri Sep 09 07:55:08 EDT 2005 | davef
This pattern indicates flex cracking due to excessive bending of the board or fixture after soldering. Ceramic is strong in compression, but weak in tension. When bending causes damaged parts, look at: * Board flexes, ceramic is strong in compressio
