TechNetters, a question has come up in our plant about cleaning copper surfaces before HASL. (Solder used is the standard tin-lead.) We've been putting panels through a light acid clean and etch, then through a Quicksilver flux applicator with two rollers that appear to be saturated with Enthone 757 SG flux. Someone has asked if that acid clean and etch are really necessary, since what is flux supposed to do? Any comments on the need for the acid clean and etch would be most welcome. Many thanks - Louis Louis Hart Compunetics Monroeville, PA USA [log in to unmask]<mailto:[log in to unmask]> 412-858-1272 --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 15.0 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 or (re-start) delivery of Technet send e-mail to [log in to unmask]: SET Technet NOMAIL or (MAIL) To receive ONE mailing per day of all the posts: send e-mail to [log in to unmask]: SET Technet Digest Search the archives of previous posts at: http://listserv.ipc.org/archives Please visit IPC web site http://www.ipc.org/contentpage.asp?Pageid=4.3.16 for additional information, or contact Keach Sasamori at [log in to unmask] or 847-615-7100 ext.2815 -----------------------------------------------------