Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

----- Original Message -----
From: "aurangzebhaque" <aurangzebhaque@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, June 22, 2009 11:34 AM
Subject: [Homebrew_PCBs] Using Silk Screen Emulsion for PCB making


> Hi everyone,
>
> I wonder if it is possible to use the photo sensitive Emulsion used in the
> silk screen making process directly on the blank PCB copper surface. I
> realize that in the silk screen process there is the silk mesh in which
> the emulsion gets trapped and then hardens to form the "screen". The idea
> that I would like to test is whether:
>
> 1. Will the emulsion initially stick to the copper surface?
> 2. Will a screen be formed on the copper surface as it does in the case of
> the silk screening process?

Silk screening used to be used for applying resist. We had a silk screen PCB
making facility at English-Electric-Leo-Marconi Computers, Kidsgrove, when I
was a student there in the 1960s. When the resist was dry, the boards were
etched in the usual way. The silk screens had to be made photographically,
of course, and they had a limited life.

Leon

Leon