"numeric" wrote in
news

"Leon" wrote in message
.
..
I don't have any problems making PCBs at home for 0.5 mm lead spacing
QFPs, or soldering them. by hand (drag soldering).

Leon

Thanks for the reply. I have though about using a laser printer to
print a negative image on clear Mylar. Then expose a photo sensitive
PCB to the negative image. The laser printer does print very sharp
lines as visible using a 10X loop. The quality should be good enough
for fine pitch. The etching process however may end up in disaster
with fine pitch lines. How do you make the PCB?


That's what I do. Then I transfer the layout to fotoboard2 by exposing
to my sunray for 5 minutes, and etch with sodium persulfate. Perfect
results. And soldering 0603 by hand is really no problem.

Sam

On Jul 1, 3:02 am, Leon wrote:
On 1 Jul, 00:30, K7ITM wrote: On Jun 30, 10:12 am, "numeric" wrote:

. Thanks to Leon for

posting a reference to another film material to try. I've had the
best luck using an Epson inkjet printer: my HP printer doesn't do as
well,

The ordinary JetStar film is suitable for dye-based ink like that used
in Epson printers. Premium Jetstar is intended for use with pigment-
based inks used with HP printers. They are available from Mega
Electronics and Farnell.

Leon

These seem to be UK suppliers. So far, my Google searching hasn't
turned up a source in the US for the JetStar films, though I am
intrigued by the product lines that Valley Litho carry. There's been
something of a revolution in how printing is done: professional laser
printers are used for short runs, offset plates are made in various
ways much more directly from computer-generated copy, and laser and
inkjet printers are used to make positive and negative
transparencies. Valley carries several items that claim to produce
dense, clean copy for exposing plates or screen film, and that should
be fine for PCB work too. I'll probably call them to get
recommendations, since a hundred sheets of transparency film is a bit
pricey to buy to just try out.

Cheers,
Tom

On 1 Jul, 17:52, K7ITM wrote:
On Jul 1, 3:02 am, Leon wrote:

On 1 Jul, 00:30, K7ITM wrote: On Jun 30, 10:12 am, "numeric" wrote:

. *Thanks to Leon for

posting a reference to another film material to try. *I've had the
best luck using an Epson inkjet printer: *my HP printer doesn't do as
well,

The ordinary JetStar film is suitable for dye-based ink like that used
in Epson printers. Premium Jetstar is intended for use with pigment-
based inks used with HP printers. They are available from Mega
Electronics and Farnell.

Leon

These seem to be UK suppliers. *So far, my Google searching hasn't
turned up a source in the US for the JetStar films, though I am
intrigued by the product lines that Valley Litho carry. *There's been
something of a revolution in how printing is done: *professional laser
printers are used for short runs, offset plates are made in various
ways much more directly from computer-generated copy, and laser and
inkjet printers are used to make positive and negative
transparencies. *Valley carries several items that claim to produce
dense, clean copy for exposing plates or screen film, and that should
be fine for PCB work too. *I'll probably call them to get
recommendations, since a hundred sheets of transparency film is a bit
pricey to buy to just try out.

Cheers,
Tom

Silkjet film seems to be similar and is available in the US. They even
make two types for dye and pigment inks, like Mega do. It might be the
same stuff, renamed for a different market.

Leon

On Jul 1, 10:43 am, Leon wrote:
On 1 Jul, 17:52, K7ITM wrote:



On Jul 1, 3:02 am, Leon wrote:

On 1 Jul, 00:30, K7ITM wrote: On Jun 30, 10:12 am, "numeric" wrote:

. Thanks to Leon for

posting a reference to another film material to try. I've had the
best luck using an Epson inkjet printer: my HP printer doesn't do as
well,

The ordinary JetStar film is suitable for dye-based ink like that used
in Epson printers. Premium Jetstar is intended for use with pigment-
based inks used with HP printers. They are available from Mega
Electronics and Farnell.

Leon

These seem to be UK suppliers. So far, my Google searching hasn't
turned up a source in the US for the JetStar films, though I am
intrigued by the product lines that Valley Litho carry. There's been
something of a revolution in how printing is done: professional laser
printers are used for short runs, offset plates are made in various
ways much more directly from computer-generated copy, and laser and
inkjet printers are used to make positive and negative
transparencies. Valley carries several items that claim to produce
dense, clean copy for exposing plates or screen film, and that should
be fine for PCB work too. I'll probably call them to get
recommendations, since a hundred sheets of transparency film is a bit
pricey to buy to just try out.

Cheers,
Tom

Silkjet film seems to be similar and is available in the US. They even
make two types for dye and pigment inks, like Mega do. It might be the
same stuff, renamed for a different market.

Leon

Thanks, Leon! I really appreciate your inputs that have gotten me
pointed in some new directions. Maybe all this will get some other
folk experimenting and reporting back their results. First: Silkjet
is a brand of Kimoto, so if you search for Kimoto you may find more
suppliers and info. (They also make high quality laser printer
film.) Second: if you do searches like "screen printing inkjet film"
you'll find a bunch of stuff. My belief is that a film that's really
suitable for exposing screen printing emulsions is very likely going
to be suitable for transparencies for PC printing. Also, I found one
place at least that offers a ten-sheet sample pack of Silkjet
(recommended for Epson printers) for $10; I just ordered one--they
seem to not have a minimum order, even. (shop.poconoscreen.com) And
with the right supplies, you may be able to do as well (or better?)
with a laser printer; see for example the Valley Litho web site -- and
a search on "screen printing laser film" turns up lots of stuff too.
The key seems to be finding out where inkjet and laser printed
transparencies are being used commercially, and screen printing is
clearly one of those areas.

Cheers,
Tom