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Subject: Re: Dry film- negative resist... First attempt failure

From: "fan_nastelroy" <fan_nastelroy@...>
Date: 2008-10-22

--- In Homebrew_PCBs@yahoogroups.com, Adam Seychell <a_seychell@...>
wrote:
>
> javaguy11111 wrote:
>
> >
> > If you are trying to dilute down NaOH(Drano) then it could be trickier
> > since NaOH is what is used to strip the resist after etching.
>
> It would almost be impossible to develop with NaOH because even tiny
> amount will shoot pH too high.
>
> All negative dry film I've come across have specified a developer of
> 9~10 g/L sodium carbonate, at 24~27 deg.C. For paint brush style manual
> developing, I find 30 to 35 deg.C better temperature.
>
Adam is right, if you dilute in NaOH so your photoresist will pull
away so fast, i develop my dry film photoresist with sodium carbonat
with warm water too