Archive of the former Yahoo!Groups mailing list: Homebrew PCBs

----- Original Message -----
From: "DJ Delorie" <dj@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, June 16, 2008 3:50 AM
Subject: [Homebrew_PCBs] photomask shortcuts


>
> I've tweaked my UV box to even out the intensity (somewhat, not 100%
> perfect but good enough). I'm ready to actually use it now :-) I've
> got some questions about steps in the photo process that would be nice
> to skip or otherwise cheat on:
>
> ∗ Developer/stripper chemistry - is more concentrated ok? Not optimal
> from a cost point of view, but I'm thinking of time-between-discards
> and shelf life.

What are you using? It's quite critical for NaOH.


>
> ∗ Developer/stripper temperature - I can use warm water to mix it, but
> heating it up for use might be tricky. Will it work at room
> temperature,

Should be used at room temperature.

>
> ∗ Laminating - hotter OK? My laminator doesn't have a heat setting,
> and the hot air gun is too unpredictable, so do I err on the side of
> "hotter" or is "just right" important?
>
> ∗ baking - 212F for 5 min after developing. How important is this?
> How critical? Hot air gun OK?

What do you need to laminate and bake?

>
> ∗ bubbling/agitating developer/stripper - how much of an effect is
> this? With the containers I have I could "swish" the boards around,
> but that's about it.

Just rock the container. It should take under 30s for development. I use IPA
and a piece of kitchen towel for removing the resist.

Leon