Re: What can I do to keep this board from warping?

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#727

From: Archimedes' Lever
Date: Sat, 26 Sep 2009 00:35

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On Fri, 25 Sep 2009 16:02:55 -0700 (PDT), mickgeyver
<eyezkubed@yahoo.com> 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.

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From: Archimedes' Lever <OneBigLever@InfiniteSeries.Org>
Newsgroups: sci.electronics.design,sci.electronics.repair,aus.electronics
Subject: Re: What can I do to keep this board from warping?
Organization: Archimedes'Palimpsest
Reply-To: My Assistant:  Zhang Heng
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Date: Fri, 25 Sep 2009 17:35:22 -0700

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