I have received a question that I need to answer
from a customer who is making a long term buy of solder reflowed tin lead finish
boards. Plated tin lead seems to read in the .0006 inch range before hot
oil reflow on the boards in question.
One of the customers concerns is the possibility of
growth of the tin lead intermetallics that might in their mind result in an
unsolderable condition later. Projected storage is at least 5 years at
room temperature. Final assembly when done
will probably be RMA flux and wave solder in most cases. Any help
would be appreciated. Boards are individually bagged with a desiccant
package and humidity indicator strips and heat sealed.
I am looking for technical papers, other
literature, etc.
Werner: I printed out and kept all your
TechNet e mails, and in your September 3, 1997 Assembly: Dewetting; you mention
a temperature/time dependency, are there charts or other reference
materials?
Thanks to all:
Ted Edwards
Process Engineering manager
Dynaco Corp.
Tempe, AZ.