Hi Gaby As Russ states IPC 7525 is a good reference for stencil aperture design. Revision A of this document is being released at APEX this month. It has been updated to deal with Lead-free among other things. I have attached a design help tool for Aperture Design and Stencil Selection (Area Ratio Calculator). This tool can also be seen at the Innovative Technology Center at APEX in LA. Regards, -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Gabriela Bogdan Sent: Thursday, February 15, 2007 8:19 AM To: [log in to unmask] Subject: [TN] stencil apertures Dear all, Could you tell me if there is a standard for stencil apertures CORNER RADIUS? I look for indications or requirements coming from people with hands on experience regarding differences between the manufacturability of stencils with all methods (etching, laser, electroforming) as well as best solder paste release quality. I am also interested in aperture optimization for lead free pastes. Gaby --------------------------------------------------- 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 -----------------------------------------------------