Homebrew PCBs

I receive messages from this board in daily digest form. My etching
interest involves my small scale model railroad products business, not
PCB development and production. Everything I do (or hope to do) in
etching requires a double-sided approach.

So, usually, I quickly scan the digest messages rather than read them
in detail. But, I'm aware that you, Stefan, and others are working
hard to discover a way to economically and efficiently develop a
"home" (meaning small) etching operation.

I've got one that is virtually complete. It involves:

1) Power spray etching unit -- home built from plans found on Randy
Gordon-Gilmore's home page. Randy, a (mechanical?) engineer, has
worked through three iterations of etching machinery, and his home
pages contain great info. No doubt a number of members here know all
about Randy's etching developments.

2) Suitcase-sized UV vacuum exposure unit from (name escapes me at the
moment).

3) FeCl-based chemical etching.

4) Photo-resist (roll) from Think-n-Tinker.

5) Trace printing -- Have explored professional 2400 dpi output on
transparencies (excellent, excellent quality), but in my neck of the
woods there aren't many sources for this since direct-to-press
printing is so common. Have used other, acceptable printing methods, too.

My main problems to date with the system I have put together:

1) Adequate support for brass sheet, which needs to be suspended in
the middle of the tank and rotated while the power spray heads are
doing their thing.

2) Laminating photo resist to brass sheeting bubble free (the brass
sheets are cleaned immaculately; I'm well aware of the critical need
for this).

If I can find solutions for these problems, I'll use this system for
prototyping work mainly; production work will be done at a commercial
site, I think.

Sorry. Let me get to the point of this post.

If there's interest here from members, I would like to post to the
Files section a step-by-step description of how I built this system
and what devices and materials the system is composed of. This might
do two things:

1) Give some of you a pretty complete picture of what a home etching
system looks like, generally, and how to go about constructing and
operating such a system; and, in return,

2) People here on the list might make suggestions about how I can
improve the system I have and correct the problems I have with my
system as it now exists. I would make corrections and report back on
how well they work.

Please let me know if there's enough interest here for me to pursue
this from my end; it'll require quite a bit of time, and I'd rather
not get such a project underway without sufficient interest from
persons here on the list.

Thanks much,

-Brian

Brian Chapman
Cedar Rapids, Iowa


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