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Archimedes' Lever Archimedes' Lever is offline
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Default What can I do to keep this board from warping?

On Fri, 25 Sep 2009 16:02:55 -0700 (PDT), mickgeyver
wrote:

I'm trying to make a 10x scope probe that is capable of dealing with
slightly higher voltage levels of about +/- 20v yet at a high
impedance ~20Meg. This link "http://picasaweb.google.com/
UncleAltheKiddiesPal/Probe?feat=directlink" has some photo's showing
the probe and board warpage. The board was made from double sided
0.020-inch stock etched with a PCB milling machine (perhaps part of
the problem). It is (obviously) hand assembled. I would appreciate
any tips or techniques that I could use to keep this board from
turning into a potato chip during assembly.

Thank you.

al



Use 0.032" media. Bake under a flat press upon receipt of the bare
boards.

Hand assemble... no wave solder, no IR oven.

Those are the only techniques that yield 100% positive results.

Any automated process will certainly have a poorer prime pass yield.

That is, unless the PCB maker was real good at stress relief during the
making of the boards.