Hi, Amol. The process control for solder paste printing is the paste print inspection, which I assume you track the results. If your CpK results are within the UCL and LCL limits without additional paste rework needed, you should not need to replace it, unless there is obvious damage to the webbing around the foil or some other compelling reason. There is always some risk involved with tooling replacement, including stencils. Better to leave the process alone if it is working. When you do decide to replace it, don't throw away the old one until you have validated the new stencil, again using paste print inspection results. -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Kane, Amol (349) Sent: Monday, April 13, 2009 12:09 PM To: [log in to unmask] Subject: [TN] Stencil Life Dear Technetters, Do anyone of you out there have a set value (time, # of prints etc.,) that is used to replace a stencil with a new one?. I know "it depends" on a large # of factors (stencil material, print speed, squeegee type, print pressure, aperture size etc.), but is there some method to the madness or is stencil replacement essentially a "as needed" item? Thanks, Amol WARNING: Export Control This document may contain technical data within the definition of the International Traffic in Arms Regulations (ITAR), and subject to the Export Control Laws of the U.S. Government. Transfer of such data by any means to a foreign person, whether in the United States or abroad, without proper export authorization or other approval from the U.S. Department of State is prohibited. CONFIDENTIALITY NOTICE: This e-mail, and any attachments, is for the sole use of the intended recipient(s) and may contain information that is confidential and protected from disclosure under the law. Any unauthorized review, use, disclosure, or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail, and delete/destroy all copies of the original message and attachments. Thank you. --------------------------------------------------- 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 ----------------------------------------------------- --------------------------------------------------- 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 -----------------------------------------------------