Electronics Forum | Fri May 15 18:13:35 EDT 1998 | Earl Moon
| | | Does the temp. profiles used to reflow double sided pcb's through a IR oven | | on FR4 board material have to be re-established if it is changed to | | polyimide? Boards will be baked out prior to assembly. | | any response would be most appr
Electronics Forum | Tue Jun 22 00:09:14 EDT 2010 | leadthree
You should do some testing what temp you really get. Solder will melt 260~300ºC. Back to the initial question, CEM-3 is a bit harder to buy and has not many varieties. Go for FR4, you can go for a higher Tg then the common 130ºC. There is also 140,
Electronics Forum | Mon Feb 15 15:33:47 EST 1999 | Earl Moon
| Any info on the pros and cons of FR4 or Polyamide ref the use of soldering PGAs would be helpful. ie. temp co-efficient diffs, baking, wave soldering, Convection reflow etc | I'm sure you know all the basic differences as Tg, X, Y, and Z expansi
Electronics Forum | Thu Jan 20 16:06:38 EST 2000 | Mike Naddra
Regarding glass transition , does anyone have expierance glass wiht transition temperature specification , such as what are the detrimental effects of exceeding the Tg , how long over the glass transition temperature ,if any , is acceptable. Tg of di
Electronics Forum | Tue Nov 14 04:52:57 EST 2006 | Loco
To make it even more compicated, you have CTE before Tg and after Tg, altough the after Tg is way more important, because the expantion ratio will be much bigger, a pcb supplier will usually give the before Tg value. To come back to the delamination
Electronics Forum | Thu Aug 20 10:54:25 EDT 2009 | newpic
What is the minimum Tg for FR4 board to consider as Lead Free board? My issue is, I do not know what is the web for the V-Score for a FR4 Tg 180. I use to use a FR4 Tg 140 and there is no problem with it, but since we convert to Lead Free and the
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 | Fri Nov 10 17:47:50 EST 2000 | Dave F
I can�t imagine a high trace count, high via count ceramic board matching-up on price with a FR4 board. http://www.coorstek.com/coorstek/coorstek.asp?menu=literature&reference=literature.asp But that�s not really the issue, is it? The issue is the r
Electronics Forum | Tue Aug 23 16:57:29 EDT 2005 | HOSS
50% of seeing it in a single pass. The only time we do this is if we have a board off the line that has delaminated. We'll run a sample of boards through bare to confirm that we have a bad batch. Even if we see no failures on the bare boards, we'l
