Gloss mask - will increase the propensity for solderballs in assembly - may have issues with conformal coat wetting - may have issues is resolving covered fiducials due to high reflection - material tends to hide defects/conditions on the PCB surface - Gloss mask does offer a cleaner surface since the profile is lower Matte mask - prevents solderballs as surface tension is low - has good wetting/adhesion for confomal coating - has good resolution for fiducial recognition - low reflection - shows PCB surface conditions readily - is more difficult to clean, ionics are high - although I think looks better with no-clean We lean to a mask that is middle of the road in light absorption - ~ 45-55%. This seems to satisfy the spectrum of needs in fab and by our users. Jeffrey Bush Director, Quality Assurance and Technical Support VERMONT CIRCUITS INCORPORATED 76 Technology Drive - POB 1890 Brattleboro, Vermont 05302 Voice - 802.257.4571 ext 37 Fax - 802.257.0011 <http://www.vtcircuits.com/> -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Chris Ball Sent: Monday, January 23, 2006 1:03 PM To: [log in to unmask] Subject: [TN] LPI - matte vs. gloss or semi-gloss Hello All- For many years we have specified matte finish LPI soldermask. Have a supplier asking us to switch to gloss or semi-gloss to avoid 'solder smear' issues. Any input as to the pros and cons of each would be appreciated. I think I remember issues finding fiducials with glossy mask but I might just be making that up, and all the equipment has changed since then anyway..... Thanks in advance, -Chris --------------------------------------------------- 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 847-615-7100 ext.2815 ----------------------------------------------------- --------------------------------------------------- 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 847-615-7100 ext.2815 -----------------------------------------------------