What are the known etchants useful for boards made with electroplated tin etch resists ? We have been using alkaline sulfate based etchant which works very well, even with a 1 um bright tin plating thickness. Ammonium persulfate etchant was shown to attack tin. Also are there any advantages of stripping the tin when no solder mask will be used ? --------------------------------------------------------------------------------- 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 ---------------------------------------------------------------------------------