X-Authentication-Warning: delorie.com: mail set sender to geda-user-bounces using -f X-Recipient: geda-user AT delorie DOT com X-Mailer: exmh version 2.8.0 04/21/2012 (debian 1:2.8.0~rc1-2) with nmh-1.5 X-Exmh-Isig-CompType: repl X-Exmh-Isig-Folder: inbox From: karl AT aspodata DOT se To: geda-user AT delorie DOT com Subject: Re: [geda-user] DIY PCBs In-reply-to: References: <20170617081144 DOT 16928 DOT qmail AT rahul DOT net> Comments: In-reply-to "John Griessen (john AT ecosensory DOT com) [via geda-user AT delorie DOT com]" message dated "Sat, 17 Jun 2017 16:38:47 -0500." Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Message-Id: <20170618153703.D607D801F77A@turkos.aspodata.se> Date: Sun, 18 Jun 2017 17:37:03 +0200 (CEST) X-Virus-Scanned: ClamAV using ClamSMTP Reply-To: geda-user AT delorie DOT com Errors-To: nobody AT delorie DOT com X-Mailing-List: geda-user AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk John Griessen: > On 06/17/2017 03:11 AM, John Conover wrote: ... > > http://www.johncon.com/john/PCB/ ... > I also use air regeneration of the CuCl2, which might even reduce the amount of HCl needed, > but that's not a very big cost anyway. It does skip the need for any H2O2 buying > except to get started quickly. Air bubbling of copper wire under HCl will get you > a charged up CuCl2 bath eventually. DJ Delorie gets credit for the CuCl2 chemistry > efficiency details. I usually use natriumperoxidisulfate for etching, would there be any advantage to use H2O2/HCl instead ? /// I found a comparision of etching baths re. danger in [1] which says that H2O2/HCl produces toxic gases. [2] says that natriumperoxidisulfate can produce finer structures than Fe(III)Cl. [3] proposes citric acid (sounds very slow). [4], p. 7 indicates that Fe(III)Cl is 6 times faster than H202/HCl, and peroxidifulfate is inbetween (3600 / 2500 / 600 nm/min). [5], uses Acetic Acid and Hydrogen Peroxide and is a little slower (200nm/min). [6] states that perdisulphate is cleaner and safer than Fe(III) and H202 variants. Has anyone tried electrolysis as in [7], [8] ? [9] uses CuCl which can be regenerated, but has more undercut according to [10]. Regards, /Karl Hammar [1] https://web.archive.org/web/20090907183632/http://www.tuf-ev.de/workshop/aetzen/EntsorgungAetzen.htm [2] https://de.wikipedia.org/wiki/Natriumpersulfat [3] http://transene.com/wp-content/uploads/Copper-Etch-Article.pdf [4] https://nanolab.berkeley.edu/labmanual/chap1/JMEMSEtchRates2(2003).pdf [5] http://engineering.tufts.edu/microfab/documents/SOP_CopperEtch2.pdf [6] http://sfprime.net/pcb-etching/ [7] http://nontoxicprint.com/electroetching.htm [8] https://en.wikipedia.org/wiki/Electrolysis [9] http://www.goldrecovery.us/goldrecovery/documents/CuCl.pdf [10] http/www.chemcut.net/wp-content/uploads/2015/03/Chemcut_Bulletin_8_Cupri_Chloride_Proces_-Parameters.pdf ----------------------------------------------------------------------- Aspö Data Lilla Aspö 148 S-742 94 Östhammar Sweden +46 173 140 57