Homebrew PCBs

On Sun, 12 May 2013 14:07:11 -0000, you wrote:

>Hi guys 
>I am using UV exposure method on clear acetate
>
>15 secs exposure caustic soda developer about a 60 secs

UV photo stuff exposes from the top down, you may not have exposed the
resist enough.

Did you do a test series of exposures, either through a variable
filter or by progressively uncovering the board?

>
>hydrochloric acid / peroxide etchant no bubbler just sloshing about but the problem is the protective layer is coming off after a few minuets of etching
>
>hydrochloric is 30%
>peroxide is 9%

Proportion is about 1 part HCL to 3 or 4 parts H2O2 (assuming drug
store strength peroxide)?

Harvey

>
>Any advice please
>Dave