Homebrew PCBs

I'm gonna make a prediction.
If you're setting up a continuous run process, there may be a lot
of options.
For those of us who want to make a board once a month, there are a
number of issues.
Given the smallness of the print head holes and the etch resistness
of the ink, I expect there won't be a printable resist with the
shelf life that we low volume users need.

I predict that a workable low volume solution will require a two-part
resist.  You slather part one on the board.  Then you print the
pattern with part two.  I expect one might find a low viscocity
printable fluid that reacts with the other part on the board.

It's very much like photo printing except.
You're just using printed patterns rather than light.
IN fact, i wonder if you couldn't just start experimenting with photosensitive
boards and print the pattern in developer.  That shows you how much I (don't) know about photography.

I've toyed with the possibility of printing an electroless plating
solution that resists the etch.

IIRC, early TEK boards were copper plated with more copper then nickel then plated with gold.  The gold resisted the etch.  But maybe I don't
know what I'm talking about.
mike

--- In Homebrew_PCBs@yahoogroups.com, "iulian_dbc" <iulian_dbc@y...> wrote:
> 
> Hello,
> 
> i noticed the struggle for good quality PCB's and i was wondering if
> there would be an opportunity to design some sort of print technology
> to print our tracks directly onto the PCB board. No UV, no PNP, no
> marker. I think i found a way to do this wit available parts and
> technology, the only thing i really need to know is if there are
> people interested in buying or building such a device.
> 
> Basically the "machine" will do the following things
> 
>   1. Print of some protective laquer onto the PCB board to delimit
> areas to be protected at etching stage.
>   2. Print the solder mask onto the board
>   3. Print component legend onto the board
>   4. optional the machine will have an interchangeable head to allow
> drilling of holes into the board.
> 
> 
> thank you for all your answers.
> 
> iulian