Electronics Forum | Tue Aug 25 03:24:11 EDT 2009 | fiona_j
Hello, I have been recently bringing a new RoHS wave soldering machine into production. Unfortunately, I am finding many of the boards are experiencing blow holes. It is always silver plated PCBs and I believe it is related to moisture ingress. I n
Electronics Forum | Tue Nov 28 22:34:55 EST 2006 | davef
Almost all boards are hydroscopic. In this, the epoxy holding the board together absorbs moisture. Almost all components are hydroscopic. In this, the epoxy encapsulating the component together absorbs moisture. So, as you heat the board / compon
Electronics Forum | Thu Aug 04 07:50:49 EDT 2011 | mosborne1
Thanks Dave - IF you look ath the Fancort RA-18HT. This is a high temp plastic that will handle 350 F. This is what we need, but in the 8 1/2 by 20 size. No one seems to make them now. We are a bare board manufacturer as well se wee bake boards at hi
Electronics Forum | Tue Oct 30 18:43:31 EST 2001 | mparker
My first thought is board warp. This is something you can't see when the board is in a reflow oven. I see it occasionally going through wave solder. You may need a pallet with hold down clamps for reflow. Try putting a bare board in a baking oven at
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 | 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 | Tue Sep 07 17:12:34 EDT 2004 | davef
No one knows what type of board you use. So, assuming you're talking a fairly standard FR4. Q1a. actually, what is max temperature and duration can a bare PCB reflow without any quality problem? A1a. We'd guess your board could take 250*C for may
Electronics Forum | Tue Jul 18 18:53:23 EDT 2006 | Mike F
Is it showing up after wave or reflow soldering, or after hand soldering? If the delamination or blister bridges between traces you have the potential for a short circuit between those traces. A delamination might be repairable, but in most cases i
Electronics Forum | Tue Mar 17 10:47:56 EDT 2020 | davef
IPC-1601 covers PWB bake-out, methods for determining optimum bake time and temperature, caveats for certain PWB plating finishes, etc. IPC-1601 is to bare boards as J-STD-033 is to components
