Homebrew PCBs

Toner transfer is more appropriate for prototypes. Why? There are
fewer steps with toner transfer - draw PCB art on computer, laser
print it, iron on to PCB, remove paper, etch PCB. 

Silk screen is best for mass production. There are more steps: obtain
silk screen and frame, photosensitize the silk with emulsion, draw PCB
art on computer, print to transparency film, use that to expose the
silkscreen, develop silkscreen, clean, then print PCB with silk screen
ink, dry ink, etch PCB, remove ink from etched PCB. Clean ink from
silk screen (if you want to use it again!) soon after last print made.

The resolution attainable with silk screen depends on the "mesh" of
the silk, that is (I think) the number of threads per inch of the
fabric.  I don't know the limits, but I think pretty good resolution
is possible. I made some PCBs with silk screen 25 years ago; the
technology was friendly, that is, with just simple instructions I was
able to make the PCB's without much trouble.

More equipment is required to do silk screen - silk screen and frames,
work area for printing, some way to get the screens to hinge up, and
some way to hold the pcb during printing, ink, squeegee, cleaning
solvents, developer for photosensitive emulsion, the emulsion itself,
chemical to clean screen if you are going to reuse it. All you need
for toner transfer is an iron and toner transfer paper, which may be
simple paper of various kinds.

There is at least one member on the list who used silk screen
commercially, so if you have questions, he has the answers.

Grant  

--- In Homebrew_PCBs@yahoogroups.com, Balan <balan3@y...> wrote:
> Hi
>  
> I am just learning the art of PCB making. Can Someone tell me is it
possible to transfer etch resist onto a board using Silk screen and if
possible what is the difference between toner transfer methord and the
silk screen.