Electronics Forum | Fri Oct 15 11:05:50 EDT 1999 | Mark Phinney
Earliar we had problems with board warpage, Much of our problem was due to imbalances in the copper on oppisite layers in brief on a 8 layer board the copper on layer 1 should = the copper on layer 8, 2=7, 3=6, 4 = 5. We added copper to some layers t
Electronics Forum | Fri Dec 17 10:42:58 EST 2010 | hegemon
I believe there is a lot pertinent information in the thread that Dave forwarded... But (IMHO)I think you can look at two things first. First, is your wave solder process friendly to this large PCB, is there enough pre-heat in the board before it h
Electronics Forum | Mon Dec 31 08:59:36 EST 2001 | Don Adams
The second pass in the wave is pretty extreme and will probably aggravate the conditions which caused warpage in the first place. Areas to look for problems, The lay up of the boards at fabrication or the materials used can lead to warpage. Work wi
Electronics Forum | Fri Jul 13 04:58:01 EDT 2007 | pavel_murtishev
Good afternoon, Heating/Cooling rates contribute to warpage most of all. Try to tweak you profile so that heating/cooling rate would be minimized. Try to switch cooling blowers off maintaining required peak/TAL. Check copper balance for this PWB, by
Electronics Forum | Tue Apr 29 11:18:16 EDT 2008 | julienvittu
basically your problems come from the copper balance top and bottom side we are using substrate down to 0.18mm (semiconductor industry/ Bga package / SIp business) you have to respect 5% difference maximum between Top and bottom side otherwise you
Electronics Forum | Sat Jan 30 16:42:32 EST 2016 | davef
Many board fabs help their customer understand the importance of copper balance. Copper balance * http://www.multi-circuit-boards.eu/en/pcb-design-aid/copper-balance.html * http://electronics.stackexchange.com/questions/85633/what-is-copper-thiev
Electronics Forum | Tue Jun 20 06:47:53 EDT 2006 | Julien VITTU (STMicro)
hung copper balance is really critical in your case. in the same configuration we have specified less than 5% copper variation between top and bottom layer if you keep this rule, assembly will be ok, otherwise you will get a terrible warpage after
Electronics Forum | Fri Jul 13 17:01:50 EDT 2007 | sean10
Thanks for your inputs. The board construction seams to be balanced and boards comes back to flat after top side process. we'll be performing experiement variing the profile parameters. if that does not do it, any printing suggestings? Would more sq
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 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
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