Homebrew PCBs

Andrew,

I payed about $220 for 300 meters, that's roughly 984 foot. 300 meters 
will last you very very long. I acutally sold 250 meters of it and kept 
the remainder. That way I had my 50 meters for about $36.... No if you 
compare this to the very small piece I use for the formentioned stencil 
that's truly almost close to nothing right?

I'm also a user of a german (I live in Switzerland) PCB/Electronics 
forum, and there we usually organise collective orders then makes the 
costs much more reasonable for the individual. You will find that with 
professional bigger suppliers you have to order the rolls of it in pairs 
cause the professional laminators use one roll for top and one for the 
bottom layers of a PCB. They are packaged this way from the 
manufacturers, so it's obvious that a supplier usually is not willing to 
break a package in a part he eventually can't sell anymore therafter.

I use Ordyl Alpha 950 from an italian importer which also operates 
worldwide. Their US office is here:


      Lakeville Office:

*ITC Intercircuit N.A.*
21625 Grenada Avenue
Lakeville, Minnesota 55044
Phone: 952-469-2310
Fax: 952-469-2007

That's hence at least one US based source I can name for you, but there 
are definately others. Might be that the board shop near you since they 
are not supplying material to you at least is willing to let you know 
who their supplier is should you want to have an alternative. I'm not 
fluent enough in english to know for what to search the internet or 
yellow pages etc. in english.

BUT, why not make a poll here among the US based users of this group who 
would have interest in buying some reasonable amount of it from you (or 
someone else) who buys a pair of rolls? I'm sure either ITC or one of 
their sub supliers will be happy to sell it to you, and I'm also sure 
many users here may want to try it out. I'm happy to assist first time 
users here with questions etc.

The rolls have a limitted shelf live. However, that's mostly only 
important for industrial use. In other words, ask whatever supplier you 
find for end of live rolls. Usually you get them (if available) with a 
steep discount. The ONLY "problem" with these kind of rolls is that the 
material starts to stick together on the outer areas of say a 30 cm 
roll. That's because it slowly reacts with the oxygen in a fashion where 
the resist material starts to kind of glue a little. Only about 2 - 7mm 
are affected, the inner area (alas the huge part of it) will remain 
unafected for many years. You should store the material in a dark dry 
envireonement, and make sure no pressure is applied to it. If you roll 
it, make sure to construct some holder so as the material is "held" by 
the roll itself and not that the roll is laying on a shelf or else the 
material will react at the point of pressure. Let me clearly state that 
the photosensitivity of the material is NOT affected over time if it's 
stored dry, DARK and at reasonable temperatures.

For homebrew use, the above shelf time limitt is of absolutely no 
concern cause you likely will cut off individual pieces which you then 
hand laminate. I for example cut 16.5cm long parts of the roll, which I 
then cut down into two 10.5cm parts dumping the excess. This gives 2.5mm 
of overshot for a so called euro card, and as you can see there will 
always be a remainder (since the roll is 30cm wide). In other words, if 
the borders stick a little (only really just a little) that does not 
matter cause you cut this part away anyways. For industrial use this is 
of course catastropic and as such this is the reason why you should get 
a significant discount ordering THIS kind of rolls. Of course, you can 
also buy "official" material at it's full (se above for an aproximation) 
price.

I could order material here and ship it, but I doubt that this would be 
so very cost effective as oposed to one of you US based guys doing it. 
Should however nobody be found doing this for interested parties here 
(ok, let's wait for the result of a poll) I'm definately willing to help 
you guys out.

Markus

Andrew schrieb:
>
> Markus,
>
> Where do you get your dry film laminate.
>
> There is only one PCB shop in my city and
> they are not interested in supplying me
> any consumables.
>
> Think-n-Tink sell some
>
> http://www.thinktink.com/cgi-bin/cart.pl?db 
> <http://www.thinktink.com/cgi-bin/cart.pl?db>|photopolymers.dat|
> Photoresist
>
> But at $85USD for a 50 foot roll that is
> hardly in the "close to no cost" catergory
> you mentioned when talking about the
> stencils.
>
>