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Date: | Wed, 20 Mar 1996 16:22 -0500 (EST) |
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A few years ago at my last job...
We had some "quick and dirty" fixtures for some .028 flex assemblies
made at a local board shop. We gave them a penciled sketch and they
worked some magic with their Excellon. They used.093 unclad FR-4
material. They routed the board shape ~.030 deep, and routed thru
where the thru hole parts needed to contact the wave. We allowed
~.050 gap between the edge of the pads to be soldered and the edge of
the openings.
They also made some FR-4 "clamps" with slots for stainless steel #4-40
fasteners. The assemblers dropped the board in, slid the clamps over,
and installed the thru-hole parts while standing right there at the
wave solder machine.
The assemblers ran them 150-200 passes over the wave, and they still
looked new when the project was complete. (We learned later that the
assemblers were weighting the boards in the center to keep the wave
from pushing the board up and allowing the solder in.)
Joe.
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