Electronics Forum | Mon Apr 02 09:42:35 EDT 2001 | davef
Check "Chapter 5: Punching Grade Of Copper Laminates" by RJ Konsowitz in "Printed Circuits Materials Handbook" edited by MW Jawitz
Electronics Forum | Wed Jun 04 10:51:28 EDT 2014 | clydestrum
Well, we cannot make the cuts any deeper as then we would incur a significant amount of "bowing" at SMT placement/reflow. -Has anyone ever heard of changes in material/laminate makeup that causes this? A sort-of stronger, or more flexible tensile st
Electronics Forum | Fri Jan 05 20:12:22 EST 2007 | engr
I am using PWB material Rogers 6002 High Frequency Laminate. The PWBs are assembled. They were washed and will require a bake out. Some people say, no bake out is required for the material. I am getting different reads in test if the CCAs are not
Electronics Forum | Mon Apr 28 19:50:09 EDT 2008 | boardhouse
My guess is that either the board house did not cool the boards down properly coming out of the lamination oven. Typically after they come out of the heat chambers they go into a cool down chamber for x amount of time, if they cool to fast or are pu
Electronics Forum | Tue Sep 18 07:52:29 EDT 2007 | davef
Does the change from supplier to supplier as a result of: * Board definition? * Differences in processing at fabs? 3 Specification Fir Tree General Technical Specification 3a Design/Layout: * IPC-2221 * IPC-2222 3b PCB Fab: * IPC-6011 * IPC-6012 * I
Electronics Forum | Mon Dec 09 09:31:35 EST 2002 | MA/NY DDave
Hi Just one idea, many exist. If your electrical designers can tolerate it, sometimes a cross hatched design is used under areas where electrical performance is important. It reduces coupling and impedance effects compared to a full layer. Elimina
Electronics Forum | Fri Feb 28 09:08:03 EST 2003 | davef
Without drilling through the numbers, they're probably correct. Recognize that standard warp / twist specs [IPC-A-610 1.5% for PTH only and 0.75% for SMT] are not going to make it on tech boards. You need to define specific requirements. This warp
Electronics Forum | Tue Jan 10 22:10:58 EST 2006 | davef
Muse We don't believe that the IPC TM-650 Test Methods Manual, 2.4.1E, Adhesion, Tape Testing--5/04 [ http://www.ipc.org/4.0_Knowledge/4.1_Standards/test/2.4.1E.pdf ] that you refer to is a "black pad" test. We think it's a method for testing the a
Electronics Forum | Wed Jun 03 09:04:19 EDT 1998 | Steve Gregory
Hi Anthony! Earl's right, things can get rather involved when you start discussing ALL the things that affect whether or not a board is going to warp. The way I look at the issue is try to separate the warp issue into two catagories; 1. The board bei
Electronics Forum | Sat Aug 03 07:29:20 EDT 2002 | davef
IPC-PE-740 "Troubleshooting for Printed Board Manufacture and Assembly" has words to the effect of � 1.5---BAKING Laminate materials are baked several times during the manufacture of a printed wiring board. There are four major reasons for
