Electronics Forum | Tue Aug 26 07:44:06 EDT 2008 | davef
Industry-wide, there is no current requirement for baking of bare boards. It adds no value. * IPC-HDBK-001 has guidelines olden times. * IPC-TM-650 has several test methods to determine moisture resistance to both liquid immersion and absorption from
Electronics Forum | Fri Oct 04 11:34:42 EDT 2002 | Bob Willis
Some additional comments from a paper may be of interest. Baking Printed Circuit Boards - Why and How Baking printed boards prior to conventional and surface mount assembly should not be necessary. Often boards are baked for historical reasons; in
Electronics Forum | Wed Oct 02 20:59:23 EDT 2002 | davef
We�ve been stewing on this and it just dawned on us the part that�s missing. Blow-holing is caused by BOTH of the following: * Moisture absorption by the resin that holds the board together. [Steve is addressing this with his various baking schemes
Electronics Forum | Tue Oct 15 10:12:44 EDT 2002 | davef
1) Do people always bake, sometimes or never? Does this depend on whether MS sensitive components are near the rework site? If a BGA is to be removed and reballed, baking is a no-brainer. Sometimes, based on the proximity of the MS components. >2)
Electronics Forum | Wed Jul 28 20:28:26 EDT 1999 | Carlos Palacios
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 n
Electronics Forum | Fri Aug 10 07:33:32 EDT 2007 | davef
Tran Since we all agree that J-001 has no baking requirement, why are you baking the boards? What is the purpose of this bake process?
Electronics Forum | Thu Aug 09 09:05:09 EDT 2007 | davef
There are no requirements acceptance criteria for baking of board assemblies. What are your customer requirements? The common reasons people choose to bake PCB are to prevent: * Delamination of multilayer boards * Measles, particularly on double si
Electronics Forum | Thu Aug 09 19:13:37 EDT 2007 | htran
DaveF, Our customer requirement is to comply with IPC-STD-001 but the J std doesn't specify the bake out temperature for populated boards and the moisture absortion rate. Right now we are baking the populated PWAs after aqueous wash at 80C at 18-48
Electronics Forum | Wed Aug 08 17:26:40 EDT 2007 | htran
Hello All, I have been searching for the board assemblies bake out requirements acceptance criteria but unsuccessful. Does anyone knows if there are general guidelines for the percentage of the moisture absorption in the PWBs and PWAs? Thanks, Tran
Electronics Forum | Fri Aug 10 16:22:35 EDT 2007 | htran
Davef, The J Standard-001-DS(Ref. 4.9.3)does required board assembly bake out and the purpose of the bake out is to demoisturize the PWB and to prevent board delamination during reflow like you have mentioned earlier. Thanks for your inputs. I hav
