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 18:59:24 EDT 2002 | Armynski
Carol, That time is also acceptable (2 Hrs @ 125 deg C) u can use this too... 6 Hrs @ 75 deg. C regards, Dreamy
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
Electronics Forum | Tue May 21 17:25:28 EDT 2002 | Carol Stirling
Hi Dave F, Thanks for the reply, the question was Customer driven. Could you clarify your recommendations for heat sealed moisture barrier bags please - does this include Nitrogen vac pack? Our production runs are small, so there is an investigat
Electronics Forum | Tue May 28 22:06:09 EDT 2002 | arcandspark
Two hours at 125 C will do nothing. IPC's new spec is 48 hours at 125C, the old spec I use to use for years was 24 hours at 125C. I do not have all the spec in front of me but if you reduce the temp to around 60C it can take up to 48 days. We use to
Electronics Forum | Tue May 28 22:06:18 EDT 2002 | arcandspark
Two hours at 125 C will do nothing. IPC's new spec is 48 hours at 125C, the old spec I use to use for years was 24 hours at 125C. I do not have all the spec in front of me but if you reduce the temp to around 60C it can take up to 48 days. We use to
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 | Thu May 09 17:28:33 EDT 2002 | davef
There is no IPC specification, nor should there be. * There are just too many peculiarities in the design and fabrication of PWB. * The issue is not defining how to store boards. The issue setting expectation for reliable products and allowing you th
Electronics Forum | Tue May 21 20:27:05 EDT 2002 | davef
No N2. We could not fix a benefit for N2 in our minds. Just fold the excess bag material over to expell most air and then seal the bag. [Have you assessed the benefit of N2?] F Monette can tell you stories about little versus more pressure. If he
