Phil/Rudy: Just a quick addition on the Sulfuric/Hydrogen Peroxide etch chemistry. You have to be careful on the loading factor ie sq ft/gal due to the exothermic nature of the chemical reaction during etching. Most of these baths require some type of cooling or two tanks to alternate between. Also on the Sodium Persulfate concentration,it can be run down in the 30 grams/liter range and still produce acceptable etch rates for an electroless line. Of course you know how those chemical salesmen are, big on dragout chemistry :>) Regards Michael Barmuta Staff Engineer Fluke Corp. Everett WA 425-446-6076 -----Original Message----- From: <Rudy Sedlak> [mailto:[log in to unmask]] Sent: Tuesday, June 12, 2001 1:42 PM To: [log in to unmask] Subject: Re: [TN] Sulfuric peroxide preplate microetch In a message dated 6/12/01 8:57:10 AM Pacific Daylight Time, [log in to unmask] writes: Phil: Happy to help, do be careful, you have made a coupla errors that could have been dangerous if implimented.... << What it the standard formulations for sodiium peroxide or ammoniun peroxide microetch You mean, Phil, Sodium or Ammonium PerSULFATE, (There exists Sodium Peroxide, and you do not want to go near the stuff.....) Figure 8 oz/gal (60 grams/liter) Sodium Persulfate, which is preferred over the Ammonium salt, because the Sodium Salt does not chelate, thus waste treats easily. Add 1-2% Sulfuric Acid, you there. and the sulfuric/hydrogen peroxide The big problem with sulfuric/peroxide is that the peroxide is inherently very unstable, and you gotta buy a proprietary additive to keep it stable, otherwise, things can get a little unstable as you introduce Copper into the solution. Also is the temperature elevated or at ambient temperture. Temp usually runs ambient to slightly elevated (under 100 F) depending on spray or soak, immersion time, etc. >> Rudy Sedlak RD Chemical Company ---------------------------------------------------------------------------- ----- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------- ----- --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------