Homebrew PCBs

--- In Homebrew_PCBs@yahoogroups.com, "#@!%! Herzog" <hwanghetw@y...> 
wrote:
> The real problem is that the toner is unlikely to resist the 
etching 
> solution.  

This is incorrect.   Half of this list if filled with people who use 
laser toner as a resist on a weekly basis.  It is THE simple way to 
get started.

Toner is basiscally plastic and totally resists the etching solution.

> Inkjet ink probably will not resist corrosives either.

This is dependant on the ink.   


> The best way to do this is to print a transparent real size image 
on 
> a clear material in the laser printer. 
> 
> Then, use a photo-silkscreen to transfer a printalble image (the 
part 
> exposed to light solidifies, the unexposed washes away). 
> 
> (Later, you can remove the whole image with bleach, re-apply photo-
> sensitive emulsion and create another photo-silk screen with the 
same 
> screen again and again.)
> 
> Then print with any acid/ferric chloride resistant media (your 
choice 
> depends on cost and cost of removing after etching - good old 
shelac 
> dissolves easily in alcohol or you can buy more expensive rosin 
> formulas from an art supply used for etching copper plate for art 
> prints).
> 
> Also, the toner is a thermoplastic powder that is melted onto the 
> paper after printing.  How do you expect to remove it from the 
copper 
> after the etch?
> 
> Sorry if you alread kwow all this - it is tradional technology.

This method is traditional, but overly complicated for those of us 
who want simple.

the direct laser techonolgy is still a far off hope.

Direct ink-jet is just waiting to be done.   There really is no 
technical reason why it cannot be done.   Look at your motor fan 
belt.  it is printed with an inkjet onto the rubber and it is 
probablly a few years old and still readable.

The problem we are running into is that the current low cost ink jet 
printers are desigend for a specific pigment size and viscosity ink.

The permanent inks like in your resist pen are not widely available 
and latex or enamel or other type inks/paints are not made with micro-
fine particles.

Currently there is a whole industry that prints on everything from 
cardboard boxes to tools with a very permanent ink-jet.

Also, there is a thermal wax transfer printer that may be a 
candidate, but is not available in mass as yet.

One option that is possible, but not often discussed is 
photosensitive boards and direct laser exposure.   This would skip 
the toner, but require photo sensitive boards.   Since a laser 
printer already has both the accuracy and speed, this too is just a 
technology ready to be cracked.

Dave