On Sun, 28 Jul 2002, Tal Dayan wrote:

>Isn't it easier to deposit light that to deposit ink jet.
>
>When you think about it, all you want is certain portions of the
>board to be exposed to light. One can think about a reverse scanner
>that scan the board with a single laser point and render the
>image on the photosensitive surface. This is actually how
>laser printer works.

You are describing a photoplotter.

Look it up on the web. The problem consists in its having to be UV to
expose the photoresist. The required UV optics are unbelievably expensive.

He is trying to print acid resistant plastic based ink directly onto the
PCB. This requires a special print head (non-thermal for sure). There are
industrial printers like that, they print onto packages and cans up to a
few cm away from the head, and at amazing speed. They also cost amazing
sums of money. Maybe one of those could be adapted to work with an etch
resistant ink. The price point however, and getting to write your software
for something that has a speed measured in meters/second of print matter
... afaik you can't slow these down because the ink feed and the ink
proper are designed for ultra fast operation. If you slow it down the ink
dries in the print head or on the nozzle(s) and the ejection mechanism
does not work right anymore (the ones I had to do with used piezo
ejection and electrostatic deflection).

Peter

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