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

----- Original Message -----
From: "javaguy11111" <javaguy11111@...>
To: <Homebrew_PCBs@yahoogroups.com>
Sent: Monday, June 16, 2008 5:22 AM
Subject: [Homebrew_PCBs] Re: photomask shortcuts


>> >
>> > "Leon" <leon355@...> writes:
>> >
>> >> > ∗ 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.
>> >
>> > Whatever samples javaguy is selling - http://www.pcbhobbyist.com/
>> >
>> >> Should be used at room temperature.
>>
>> He recommends sodium carbonate, which isn't generally used. I use
> about 12
>> g/litre sodium hydroxide. Sodium metasilicate is popular, and has
> much more
>> latitude than NaOH. NaOH has unlimited shelf life and can be reused.
> A more
>> concentrated solution can be used for stripping resist.
>
>
> Actually the datasheet for the resist recommends that you do not use
> NaOH for developing. Instead Sodium or Potassium Carbonate is
> recommended.

It must be a different resist than is used on precoated boards. Is it
negative?

Leon