Bob:

I have encountered the same problem that you have indicated. For a NASA
application I have used specification A-A-55485/6A mounting pads. I have
used A-55485/06-010D under CK06 parts and A-55485/06-048D under CK05 parts.
This spec is a replacement for the old Mil-M-38527/60 spec. The spacers are
made of diallyl phthalate and can be purchased from a number of sources as
listed in the spec.

The spacers remain permanently under the parts. The spacer holds the part
off the board while allowing a topside fillet to form while wavesoldering.
The need for this spacer has diminished as both the CK05 and CK06 parts can
be purchased with an integral standoff. However, the high rel parts M123A01
and M123A02 are not available with the standoff and therefore the spacer is
necessary.

Respond if you need more help.

Bill Kasprzak
Moog Inc.

> -----Original Message-----
> From: Bob Crain [SMTP:[log in to unmask]]
> Sent: Thursday, February 03, 2000 5:17 PM
> To:   [log in to unmask]
> Subject:      [TN] Temporary stand offs for wave solder
>
> We are converting some old hand solder aerospace PCA designs to wave
> solder. The transistors and CKR05 type capacitors need temporary stand
> offs.
>
> We cannot use standard dissolvable spacers because we use alcohol solvent
> cleaning and are not allowed to use water.
>
> Suggestions? One thing I would like to consider is a high temperature,
> non-silicone, non-sulfur rubber sheet in thicknesses of .030" and .050."
> Any ideas for the best material to use? Are there any removable clips that
> fit over the parts to hold them up?
>
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