1. If nothing dissolves the haze- alcohol, flux thinner, acetonitrile, water- then it is time to trot out the hair drier to see if that does the trick. Run a scrap board through the wave, make sure it has the white haze, then turn the hair drier on and aim it at a spot on the PWB surface. If what you are seeing is underdeveloped solder mask, the white stuff is the fumed silica used as a thickening agent in the LPI mask. [If the mask is not completely cured/cross-linked, then the flux and its solvents will dissolve away the mask, exposing the whitish thickener or skeleton of the mask. Heat up the material and the white residue will sink into the body of the mask and disappear. Check the UV lamp output to ensure you are or your PWB supplier is completely curing the mask.] 2. Another possible (if naught else works out from TechNet) is OA material cross linking to give large insoluble polymers. This was described by one of IBMs leading scientists at an InterNEPCON conference in the UK. I still have the paper in my copies of all NEPCON proceedings back to 1977. If this turns out to be the case, alternative OA flux formulations may need to be tried. Bill Kenyon Global Centre Consulting 3336 Birmingham Drive Fort Collins, CO 80526 Tel: 970.207.9586 Cell: 302.377.4272 --------------------------------------------------- Technet Mail List provided as a service by IPC using LISTSERV 1.8e 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 847-509-9700 ext.5315 -----------------------------------------------------