Homebrew PCBs

Hi all.

I mostly used Epson photopaper to make my quick-and-dirty
toner-transfer PCBs, but was tempted by a local electronics magazine
announcing an 'ideal' paper. Though the paper they sold was pretty
expensive, I'm quite sure the paper was just a good quality
illustration sheet. Anyway, I bought a couple of the 'originals',
and printed a board. Strangely there were some defects, so I used
another part of the sheet to re-print the board - same defects.
Worried, I re-printed on normal paper, and did _not_ have the defects.

The actual defects are difficult to describe. Here are a couple of
pics:

http://jcoppens.com/misc/laser1.jpg
http://jcoppens.com/misc/laser2.jpg

Left side is the magical paper, right is normal paper. As can be seen,
the left paper is better quality print (traces are 0.3mm), but some
strange 'explosions' occured. These seem to appear independent from
the place on the sheet, and _always_ on the better paper, never on the
normal one.

Any suggestions or ideas for identifying the cause?
John

> Any suggestions or ideas for identifying the cause?
> John
Just an idea: could You pass the paper into the printer without printing 
anything but simply ro preheat it?
I'm thinking about humidity...

Best Regards
Armando

"Ken Carlson" <kencarlson@...> writes:
> actually it may be to dry

Easy enough to test this one - rehumidify the paper.  Put it an
enclosed container with a bowl of water for a few minutes.

>Any suggestions or ideas for identifying the cause?
I used to work on copiers and we would see these kinds of defects all the 
time with
various papers. The copier manufactures would call it blow off. I am not 
sure of the
exact cause but I suspect a charge buildup on the paper and as it discharges 
against
"something" fusing rollers guides whatever it blows the toner around.

Some things we used to do to minimize it was change the charge voltages 
(which I dont
think you can do on a printer)and toner density you might be able to turn on 
a toner saver
or something to make it less dense.

Most of the time its just a paper incompatability with the printer that cant 
be compensaited
for.

I dont think that its to much moisture in the paper actually it may be to 
dry if you get to much
moisture you will get large patchy voided areas.

Good luck
Ken