Electronics Forum | Tue Aug 28 08:28:30 EDT 2012 | rgduval
We agree with all of the previous comments, and would add the following: Warpage is generally caused by excess moisture in the raw boards. Have you tried baking the boards prior to assembly? We had this issue on a simple 4-layer board, and found t
Electronics Forum | Sun Dec 08 22:20:39 EST 2002 | grantp
Hi, We have been manufacturing a PCB, however it's been quite tricky to profile, as the edges of the PCB are reflowing before the center of the PCB. I have looked at the design, and there is a small power plane for 2.5 Volt in the center of the PCB
Electronics Forum | Wed Dec 19 21:21:02 EST 2012 | davef
MosheSh: When it comes to ground planes, most designers are out over their skis. They don't understand what's going on or how it affects their design. So, they get massively conservative about the number of plane layers, whether they can be hatched o
Electronics Forum | Fri Feb 19 09:29:38 EST 1999 | Justin Medernach
| What to look for that causes tombstoning and the corective action. | The three biggest causes that I can think of are placement machine component picking inaccuracy, placing inaccuracy, and design design design. If your placement platform is pic
Electronics Forum | Thu Aug 10 13:12:10 EDT 2000 | Bob Willis
You may care to review the following from my Circuits Assembly page on line. "HOW FLAT IS FLAT AND DO WE NEED FLAT CIRCUIT BOARD, YES WE DO ? As production problems go there is one that keeps reoccurring time and time again. The blame is usually di
Electronics Forum | Fri Jul 13 08:54:18 EDT 2007 | rgduval
Has your board house reviewed the PCB layer stack? Make sure that the layers are balanced in copper weight, etc? Have you tried pre-baking the boards? We just had an issue with some boards warping that have never warped before for us. It happened
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 | Wed Nov 13 04:12:20 EST 2013 | hqew2013
Do you design or define PCB layouts? If so circuit board, what rules and checks do you have in place to make sure your results are... optimal? Over the years, I've created a PCB design checklist to keep me out of trouble. I share these nuggets with m
Electronics Forum | Wed Aug 19 08:00:55 EDT 1998 | Earl Moon
| Hi there, | I'm actually facing a lot of trouble with PCB's presenting up to 3mm of bow /twist at reception i.e. before assembly. The PCB size is 220 by 230mm. The boards are to be assembeled SMD double sides with 05.mm pitch on both sides. In orde
Electronics Forum | Mon Apr 14 13:24:32 EDT 2008 | mmjm_1099
We had an order using a 2up PCB (same manufacturer) with same components and same board layout without any problems. Perfect run. The next order ran on the same day with same paste using same parts, same layout, same profile, but different 2up PCB h
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