Electronics Forum | Thu Jul 29 12:33:38 EDT 1999 | Wolfgang Busko
| Currently, we are baking any PCB before process on SMT, the 'reason' is to dry any possible humidity that could be inner the PCB, it does not matter if the PCB is multilayer or not. We bake PCB's at 107C for 4 hrs and the board must be process into
Electronics Forum | Wed May 07 21:20:53 EDT 2008 | davef
Causes of Delamination ["Quality Assessment of Printed Circuit Boards" Lund, Preben; Bishop Graphics 1985 0137450354] The reason for delamination is epoxy starvation in the glass cloth layers or an incomplete curing of the base material. It has been
Electronics Forum | Thu Sep 20 07:18:42 EDT 2018 | proceng1
Has anyone else been experiencing this lately? We have had a rash of boards that come in properly vacuum sealed. We store them in the hot room until we are ready to build, and we get bubbles under the solder mask. We've had 4 different jobs, all di
Electronics Forum | Thu May 15 15:02:03 EDT 2008 | ccross
We have seen this problem before. We have ALWAYS found it to be a board vendor issue. Also, we tend to see it more during the summer months. Our solution has been to bake our PCBs @ 50 deg C for 1 hr prior to use. We use immersion white tin board fin
Electronics Forum | Fri May 23 23:47:46 EDT 2008 | dint46
Wayne; Several things. 1.check the vendors and see what black oxide they are using are they the same ? It might be that. 2.You should bake your pcbs before the thermal stress is applied. To remove moisture. At your shop. The proce
Electronics Forum | Wed May 07 17:52:36 EDT 2008 | wayne123
I have these boards that are a four layer FR4 material, we had been running them for quite awhile with no trouble, and then they started delaminating, I checked my Reflow oven profile and I was barely hitting the temps required for our paste, we then
Electronics Forum | Fri May 31 10:35:46 EDT 2002 | dason_c
I think that the IPC spec only apply to the MSD. I had a paper from Lucent and forwarded by Francois Monette, please aware that the first 2 hours, the moisture doesn't bake out from the assembly/component and result show that it is increase the weigh
Electronics Forum | Mon May 27 12:24:21 EDT 2002 | arcandspark
Carol, I beleive there is an IPC spec for Moisture control. We see all kinds of problems with boards coming from the vendors. We use to bake all bare fabs upon recieving them. This helped alot but waste time. We now rely on the board vendors to bake
Electronics Forum | Wed May 08 11:07:54 EDT 2002 | Carol Stirling
We have a concern with moisture absorbtion/humidity effects on PWBs specifically used for automated SMT (including BGA). I'm sure there is a IPC spec on this and would appreciate the number - I've searched the IPC web-site -no results. Could you t
Electronics Forum | Mon May 27 18:25:03 EDT 2002 | Carol Stirling
Thanks for the information Reworkman, We are leaning to the theory of better safe than sorry. I think I'd supply the bags and dessicant just to eliminate manufacturing issues. What temps & times do you ask your boardhouse to bake to? Ours said some
