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 | Mon Mar 03 13:22:20 EST 2003 | MA/NY DDave
Hi I see David F already gave a good answer. The basic advantage, if you can afford it, is a more stable PCB during the soldering process. Higher Tg enables this. Also some materials serve to match CTEs (coefficient of thermal expansion) a bit bett
Electronics Forum | Sat Dec 13 17:46:27 EST 2008 | ysutariya
If you're military then you're probably just needing standard 130Tg FR4 and tin-lead finish. I would check two things: 1. Bake temperature: Isola recommends 300F for 4 hours to drive moisture out. Lower baking temperatures do not require a linea
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 | 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 | Sat Mar 01 08:17:40 EST 2003 | davef
You're correct that the FR4 is probably the best choise. The majority of the problems in developing your reflow recipe is going to come from the CTE mismatches in the CCBGA , CBGA and PBGA that you put on the board. The other side says given the pr
Electronics Forum | Mon Oct 03 22:12:53 EDT 2005 | davef
When we see warp and twist, we usually jump the fabricator for: * MLB construction (not homogeneous or unbalanced - too resin rich or poor) * Supplier process capabilities (lamination cycles) * Material selection (usually cheap and dirty), etc. War
Electronics Forum | Thu Feb 02 09:16:57 EST 2006 | lyrtech
Hi, I have some questions about material used in PCB for RoHS compliancy. It seems to be fuzzy between may manufacturer. Here are my questions: 1) What is the recommended material for lead-free assembly? 2) What's the difference between FR4 High Tg
Electronics Forum | Mon Nov 20 10:40:35 EST 2006 | SWAG
Thanks Mark and Dave. It sounds like our board design and problem areas are similar to yours, Mark. We talked with our customer about the grid pattern but I'm not sure where we are at with that. In reference to the Tg/Td thread, the material is a
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,
