Dear Taechung, Patrick, et al.

Several people have posted questions about how one can get high resolution
film output for their MEMS masks. Many research groups, such as ours, use
commercial imagesetters for generating their masks. The imagesetters
produce high quality masks on film with a 5 micron raster line (or
"pixel"). We get a 8.5 x 11 inch film for about $15.00 in four hours.
Sometimes we use these films directly for contact printing of the masks;
other times we transfer to chrome plates (for multiple mask processes or if
we want to further reduce to get better resolution). This is an extremely
fast, cheap way to make good masks. The 5 micron dot size is sufficient for
many MEMS projects.

To access these high resolution "printers", go to your Yellow Pages and
look under "Desktop Publishing", then find the service bureaus who
advertise "Linotronic" (or "Lino") service, or "film output" for prepress.
These prepress bureaus service the printing industry by creating the film
necessary to create the metal plates used in offset lithography printing
(many printers also do this themselves, so you can also check under
"printing"). They typically use imagesetter machines by Scitek, Linotronic,
or other manufacturers. Most prepress service bureaus are small operations
and work primarily with individuals, such as graphic designers, so they are
very approachable--you should drop by and explain what you want to do, so
they can explain how to get your drawings to them.  In Los Angeles, where
you live, there are *many* prepress service bureaus.

The bureaus usually accept Postscript (or encapsulated Postscript) files or
files from popular layout or drawing packages such as Quark Xpress,
Pagemaker, Freehand, Illustrator, etc. on disk. You have to be careful when
outputting to Postscript, as fonts can be a problem (use only Postscript
fonts) and things like line width ("stroke") become an issue. It's worth
buying a good drawing package (I recommend Macromedia Freehand, typically
$100; I strongly discourage AutoCAD) then reading the manual for the
drawing package you intend to use. These drawing packages are very
sophisticated and give you a great deal of drawing power.

When working with the bureau, you will want to specify the output
resolution, the, emulsion side (up or down), and a few things like that.
The service bureau can give you the specifics. Most bureaus will imageset
at 2540 dpi (10 microns per raster line), but those with newer machines can
go to 5080 dpi (5 microns). When you ask the bureau about their resolution,
may may quote something like "166 lines per inch". That has to do with
greyscale resolution, not true DPI. In that case, ask specifically what the
DPI output is.

Incidently, these imagesetters are not "laser printers". The imagesetters
expose film directly with a laser raster, then develop the film. This gives
high resolution without distortions. A laser printer, on the other hand,
rasters a drum which then transfers toner to a paper (or transparency)
under heat and pressure. This leads to curling, warping, shrinkage, etc.
And the toner is not opaque to light. Thus, you can't use a laser printer
to make good masks!

As I mentioned, many MEMS researchers have been using imagesetters for
several years with good success. Good luck on your own success.

-Mark Bachman.


>   Dear researchers.
>   I am trying to find the high resolution printer (Scitek 3130)
>mentioned by Ashutosh Shastry from India.  I searched local print
>shops and the internet, but I cannot find it.
>   I will appreciate it if somebody can provide me the name of the
>company that manufactures this high resolution printer or a printshop
>in the U.S. that uses this printer.
>   Thanks.
>
>Taechung Yi and Patrick de Guzman
>Graduate Researcher, Micromanufacturing Lab.
>University of California, Los Angeles
>
>
>
>
>
>

--------------------------------------------
Mark Bachman, Ph.D.
[email protected] / 949-824-6421 (-3732 fax)
Research Physicist, Microsystems Engineering
University of California at Irvine