Hi Carl We reduce our apertures 5-10% (ddepending on apertures size) and have recently rectified our solder balls problem with homeplate apertures for chips. IPC-7525 have some guidelines which may be useful. You might also want to look at changing solder paste characteristics. Regards Dennis -----Original Message----- From: Carlr Ray [mailto:[log in to unmask]] Sent: Friday, January 17, 2003 6:41 AM To: [log in to unmask] Subject: [TN] Stencil Aperture Mod How many of you guys still run product with 1:1 apertures? How many commonly use reduced or modified apertures? I have an issue where I can not convince some other Engineers that modifying the apertures to correct for solder balling is a good solution. The process is a no clean process and the profile meets the solder paste manufactures recommended parameters. The solder ball appear on next to the middle of the parts (like solder escapement) and some are trapped by the flux others or not. Do you guys know of any standards that address these issues? Carl Ray Sr. Manufacturing Engineer Huntsville, AL 35807 Phone: 256-882-4800 ext. 8845 Cell: 256-990-1990 --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ----------------------------------------------------- Scanned by PeNiCillin http://safe-t-net.pnc.com.au/ --------------------------------------------------- Technet Mail List provided as a free 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/html/forum.htm for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 -----------------------------------------------------