Hi Phil, I see no one answered on your question re: thermal stitching. Yes, is is common in the industry, although some EMS providers don't like the idea of vias under an SMT SJ. Many new voltage regulator packages have metal contacts on bottom of package that solders to board, and some vendors suggest vias to improve heat flow. Roger -----Original Message----- From: TechNet [mailto:[log in to unmask] <mailto:[log in to unmask]> ] On Behalf Of Phil Nutting Sent: Thursday, May 11, 2006 10:18 AM To: [log in to unmask] Subject: [TN] Use of Fiducials & thermal stitching My disclaimer... I'm a neophyte at SMT and need some education. Fiducials; At what point do I need fiducials on my boards? Is there a specific pitch or device size that will require fiducials? Is there a "Cliff's Notes" for this? Thermal Stitching; We have an SMT power transistor that has about 16 thermal stitch holes located directly under the device. The adjacent pad area is taken up by heat sink. Is this "industry standard"? Short of reading all the IPC standards... zzzzzzzz... oh sorry, I dozed off there, is there a good source for coming up to speed on SMT and board layout good standards? Thanks in advance, Phil Nutting --------------------------------------------------- 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 -----------------------------------------------------