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Subject: Re: [Homebrew_PCBs] Re: today's problem...

From: DJ Delorie <dj@...>
Date: 2008-07-10

"Jon Elson" <elson@...> writes:
> The edges of your resist look VERY jagged. What is your master
> artwork?

2880 DPI inkjet on Silkjet film. I've posted here before about the
printer's paper feed not being as accurate as needed, giving
comb-shaped edges.

> If the edge of the master artwork is not very sharp and crisp, it
> can cause the edges of the pattern to be jagged or thin, which I
> believe I can see in your micrograph.

Hmmm... so you're thinking it's a bit of half-exposed mask that fell
off and stuck elsewhere or something like that?

> One thing I have been doing is to scrub the board/brass with either
> steel wool or fine (600 to 1500 grit) sandpaper, wash well and drip
> dry, before laminating. This greatly helps the resist adhere to the
> laminate.

I've tried both scrubbie and 2000 grit sandpaper with comparable
results.