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Subject: Re: Printing PCB boards

From: "johnman9146" <johnman@...>
Date: 2002-04-03

That kind of misses the point. I am looking to see if anyone knows
of a suitable etch resist ink, and/or a suitable soldermask ink.

If I do decide to go your way and do the transparancy method with UV
sensitive photoresist, I have a few questions.

How do I know when I have the proper exposure?

Can you over-expose?

How dark black does the transparancy need to be for this method to be
effective?

I have access to some pretty sophisticated hardware if I do decide to
try this method. Items such as a photoplotter, a vacuum backed UV
table (for exposing printing plates) and more, but it is a hassle to
go there for all the neat toys.

I don't think there would be any issues with the image size not being
exactly 100% as it is a professional photoplotter designed to make
printing plates for magazine reproduction.

Potentially, I may just have to experiment with different inks if
nobody has any suggestions.

Does anyone print legends on thier prototype boards?

Does anyone use anything to add a soldermask?

Does anyone even use any type of conformal coating?



> Im my opinion you're much better off using photoresist coated
boards.
>
> Print your layouts using the right transparent medium for your
printer
> (laser or inkjet) and use that to expose the board under UV. I made
a
> suitable lightbox with tubes sold as spare parts for the ready-made
> unit sold by Maplin. I also use ready-prepared developer and etcher
> from them and get a great result every time.
>
> Cheers
>
> Derryck