Homebrew PCBs

> derekhawkins wrote:
>
> I'm attempting to debunk the following two
> myths at the same time;
> 
> 1. A collimated light source is needed for
> .005" to .01" rules when photoetching.
> 
> 2. All vertical bubble etching system cause
> uneven etching.
>
> Board size is 6"X4" hung vertically as shown. 
> 
> http://www.pbase.com/eldata/6_6_rules

Nice etching.

I agree collimation is not needed and bubble
etching works well.  I currently use both an
uncollimated light source and a kinsten
bubble etcher.

My main problem I have with getting to 6/6 is
my phototool.

Printing on my personal laser I can do a 6/6
board FILLED with 6/6 like you have shown but
if I try doing a a board where 1/2 the board
is 6/6 and the other half has large areas of
copper I get problems.  During the develop
I either need to leave it too long for the
large copper areas to be pitted or I take it
out too soon and I get shorts in the 6/6 area.

I just use a little laserjet 4xxx myself.  It
just can't seem to do big black areas well.

The big laserprinter I borrow works well for
large black areas - but it is a half hour ride
to get to use.

How do your boards go with 6/6 AND wide tracks
mixed on a single board ?


I am going to build a think and tinker style
collimated box - but I don't think it is
going to make a noticeable improvement.