Electronics Forum | Mon May 20 16:56:24 EDT 2002 | Gary
Excess slump of paste and mis-registration can cause solder balls along with moisture. Use same date code of pcb and run with no components, paste only. Also pre-bake boards with humidity sensor in oven. If high humidity, moisture and solvent residue
Electronics Forum | Mon May 13 20:40:07 EDT 2002 | davef
Fine pitch parts are not the issue. Platic parts that absorb moisture are the issue. Search the fine SMTnet Archives to get started. Try: * MSD * Moisture sentive device * Dessicant cabinets * Baking times * 033 * 020 * etc
Electronics Forum | Fri Sep 13 13:16:55 EDT 2002 | stepheno
Moisture will still seep in over 12 years. Moisture barier bags are not 100%. If you accept them, conditionally accept them, and don't pay for them untill you are happy with them.
Electronics Forum | Mon Dec 16 15:38:17 EST 2002 | Randy Villeneuve
No parts or boards are baked unless they are moisture sensitive and were left out too long and that is for reflow only. In your case there should be no reason to bake becouse the boards should be vacuum packed as they come in as well as any moisture
Electronics Forum | Tue Jun 24 07:16:08 EDT 2003 | sanjeevc
The moisture sensetive bags that carry your BGAs will have the specs in regards to your baking cycles.But definetly you have to bake the BGAs if its been stored at 60% humidity.Normally the shop floor area should not be at such higher humidity.You ca
Electronics Forum | Thu Sep 11 17:15:07 EDT 2003 | davef
We've seen two source of this: * Poor cure recipe [lookup 'microcanyon' in the fine SMTnet Archives] * Moisture absorbing glue formulations [lookup psi or aguayo in the fine SMTnet Archives]
Electronics Forum | Thu May 06 14:22:06 EDT 2004 | Rob
Okay... to follow-up on my scenario. Would it be cheaper to get a resealer with dessicants and humidity indicators or a baking oven, or both. Is there a moisture controlled storage cabinet (ideally 3'x6'x1' or in that vicinity)? Would be interested
Electronics Forum | Thu Aug 05 20:42:11 EDT 2004 | Andrew
If the moisture does not has path to escape,what will happen to the entrapped moisture ,will there be a problem in the asssembly process?
Electronics Forum | Thu Aug 05 21:20:40 EDT 2004 | davef
The entrapped moisture WILL escape. You just want to assure it is not through your PTH and via. Hopefully your board is constructed such that the alternate escape path for the moisture does not delaminate the board.
Electronics Forum | Mon Apr 18 20:44:30 EDT 2005 | davef
Charly: Why do you "need to bake the PCb due to moisture issue", if you're not going to use the board? Why bake the board, just to put it back in storage, absorb moisture, and require baking again?
