Rigo Garcia: First, you are assuming that the water in the board has the same characteristics as liquid water. It does not. The water is chemically bonded, and needs more than 100 C to be driven off. Second, 125 C is gentle, compared to the temperatures the board will see during soldering.
Rudy Sedlak
RD Chemical Company
--- On Thu, 11/17/11, Garcia, Rigo (GSFC-300.0)[MANTECH SRS TECHNOLOGIES] <[log in to unmask]> wrote:
From: Garcia, Rigo (GSFC-300.0)[MANTECH SRS TECHNOLOGIES] <[log in to unmask]>
Subject: [TN] Recommended Bakeout Temperature for Boards and Assemblies
To: [log in to unmask]
Date: Thursday, November 17, 2011, 8:28 AM
Good day TechNetters!
I have been reading all sorts of materials regarding bakeout of boards and the consequences. Among some of the documents I've read is IPC-1601 - "Printed Board Handling and Storage Guidelines".
One of the main questions I still have is, if moisture contributes to delamination by the internal forces generated internally on the PCB when heating up the board at high temperatures due to the evaporation of the water, why would anybody recommend temperatures above 100 °C which is the boiling temp for water? For instance, baking at 125 °C would create the same effects we are trying to avoid, wouldn't it?
Does anybody know any good reading material to learn about this?
Thanks for the help!
Rigo Garcia
Sr. Quality Assurance Engineer
Workmanship Standards, Code 300
NASA, Goddard Space Flight Center
Greenbelt, MD 20771
Phone. (301) 286-6129
Fax. (301) 286-6576
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