Electronics Forum | Thu May 31 22:35:23 EDT 2012 | jacktan
I have encountered PCB delam issue with high density PCB. PCB has 42 layers , 5 mm thickness ,laminate material is NelcoN4000-13EP,Tg 210C and Td 350C. Have pre-bake at 125 c for 12 hrs before assy.My reflow temp is standard with 243 peak and TAL is
Electronics Forum | Mon Jun 04 08:53:44 EDT 2012 | mosborne1
Sounds like the boards were not properly manufactured since you have baked them prior to assembly. We just had a customer return from China becasue of this issue. We have made 10K without issue. Let me take a stab and ask if they were made in the USA
Electronics Forum | Fri Jun 29 07:45:05 EDT 2012 | tommyg_fla
It sounds like the flux is not holding up during the soldering operations. That would account for the webbing, etc. Also is the problem specific to a certain board type or lot code of boards? Do you think that your boards are outgassing during solder
Electronics Forum | Wed Sep 19 10:38:58 EDT 2012 | mark25y2001
It's both solderpaste or PCB pad problem... 1st it's possible that your PCB exposure problem or old stocks, remedy? try to bake your PWB. 2nd, it's possible that PWB coating (wax) are more ticked so that solder paste flux are cannot penetrate to clea
Electronics Forum | Mon Sep 17 14:45:57 EDT 2012 | kkay
We are experiencing voiding on one of our lead-free assemblies on every part. The voiding only occurs underneath the parts and not in the solder fillet (see pic). We have tried baking, curing, washing, multiple pastes and everything else we can think
Electronics Forum | Wed Jan 23 15:59:17 EST 2013 | emeto
I saw the equipment you want to purchase and .....are you sure? Don't you really want to give it to somebody to do it for you? If not buy just the printer. Print, place by hand, bake it in a cooking oven with a fan(it is very cheap). Print can be don
Electronics Forum | Mon Sep 09 17:01:21 EDT 2013 | proteus
I wish I knew the MSL. The factory data sheet from 1995 does not list the specification. The moisture problem makes perfect sense for what I'm seeing. When we replace these parts by hand (no reflow) the failure rate goes down to almost non-exist
Electronics Forum | Sat Nov 23 08:05:20 EST 2013 | emeto
Hi, I would check the thing in the following order. 1. Check paste - SPI is the best way. If you don't get the right deposit there is no wonder you have issues. 2. Check reflow profile - tweak it to the point of perfection for the board you have. 3
Electronics Forum | Thu Apr 17 07:51:19 EDT 2014 | emeto
Opens are on the device to the PCB - mainly on the edges, that makes me think I get some kind of warping,but even if I bake parts and boards doesn't help. We also tried different reflow profiles - same results. I hear that some people use dip fluxers
Electronics Forum | Thu Aug 21 16:00:31 EDT 2014 | davef
This links to a NPL presentation on moisture removal from PCB http://www.npl.co.uk/upload/pdf/20140318_effect_baking.pdf Consider: * Focusing on preventing moisture contamination of boards, rather than removing moisture * There will be no standard
