Potting Circuit Boards

[Simon Ford]

Hi,

Does anyone know anything about potting circuit boards? I want
encapsulate a small board in plastic to form a specific molded shape.
Just wondering what is possible and how to get some experiments done?

Cheers!
Simon

[Rich C]

Hi Simon,

Normally you buy a small, rectangular ABS black plastic potting box
and pour black potting epoxy into it with the PCB inside. Fill it to
just under the brim. I heard somewhere about using a vacuum chamber to
get the bubbles out. Maplin only sell a few sizes of these boxes,
Farnell have more. Think about how you want the wires to come out,
heat dissipation, and keep it small (weight, amount of epoxy used,
gets hot while curing). I bought a R/C speed controller that was in a
tiny box with the power transistor heatsink on the outside.

Wikipedia links to a good webpage about potting and how to pot surface
mount so it doesn't break:
http://www.pottingsolutions.com/my%20site/Technology/potting_hints.htm#Potting%20PC%20boards

To mould resin you need a release agent (vaseline?) on your mould, or
a break-away mould (wax or plaster of paris). I moulded a paper weight
at school and it seemed to hold detail well. Suck it and see?

Cheers,
Rich