Sodium persulfate is a rather slow etchant, but it produces a very clean surface. We used to use it as the basis for a chemical clean line prior to laminating photo resist.
I assume you put in 5 ot 10% sulfuric acid in the etch. No acid, no etch.
----- Original Message -----
From: P.O.
To: Homebrew_PCBs@yahoogroups.com
Sent: Monday, November 01, 2004 7:27 AM
Subject: [Homebrew_PCBs] Slow etching, Sodium Persulfate?
Does anyone use sodium persulfate as etchant?
I'm makeing my first pcb using toner transfer from kodak-paper. But the
etchant doesn't work very well.
I use about 0,8 dl etchant for 4 dl of water@ca 50° in a plastic bowl
that and moved stirred it pretty much the first hour... The pcb is
about 4x3 cm big.
Now it has been in the etchant all night and only about 1/8 of the
board has etched.
Maybe the kodak-paper left something on the surface? I did iron it
about 60 seconds on both sides. To long?
/P.O.
Be sure to visit the group home and check for new Bookmarks and files:
http://groups.yahoo.com/group/Homebrew_PCBs
Yahoo! Groups Sponsor
ADVERTISEMENT
------------------------------------------------------------------------------
Yahoo! Groups Links
a.. To visit your group on the web, go to:
http://groups.yahoo.com/group/Homebrew_PCBs/
b.. To unsubscribe from this group, send an email to:
Homebrew_PCBs-unsubscribe@yahoogroups.com
c.. Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.
[Non-text portions of this message have been removed]