With all the debate about components being able to take reflow temperatures
of 235, or higher, don't forget about the good old circuit board itself.

The old standard test was "time to delamination" at 260.  Now, testing is
going on to see if boards can be made from "FR-4" (what a catch all of resin
combinations to suit a UL testing protocol) can last several minutes at 280,
288, or 300 degrees.  Presents a challenge for suppliers of resin, makers of
laminate, and suppliers of process chemistries such as copper oxide
replacements.

But, I think the process development is quietly going forward in board
fabrication to be ready for elevated lead free assembly temperatures.  At
least, several projects under Interconnection Technology Research Institute
(ITRI) in Austin Texas will help find out if there are gaps.

In today's depressed board market, many shops will be afraid to ask a premium
for higher temperature boards, just to keep the customer base they are
"surviving on" here in 2001.

Dennis Fritz
MacDermid, Inc.

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