Louis: There are a number of good reasons to use an alkaline cleaner along with an acid cleaner, or microetch, to clean pre-HASL. Beside finger prints, if the developing of the soldermask was less than perfect, and residues are left behind, you need an alkaline cleaner to remove. Problem is many/most alkaliine cleaners will attack soldermask. We addressed this issue some time ago, and have developed a cleaner which removes the bad stuff, and does not touch the soldermask. Samples available on request. Rudy Sedlak RD Chemical Company --------------------------------- Never miss a thing. Make Yahoo your homepage. --------------------------------------------------- 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 -----------------------------------------------------