Mark Try this as a starter if you don't have the part manufacturer recommendations http://www.amkor.com/products/notes_papers/appnotes_LGA_0902.pdf Also this Intersil Tec Brief has good design guidelines http://www.intersil.com/data/tb/TB389.pdf Mickey -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of kwood716 Sent: Tuesday, August 26, 2008 9:18 PM To: [log in to unmask] Subject: Re: [TN] LGA footprint Mark, Do you have a part number for this device? I'd be happy to take a look at it for you. Regards Ken _____________________________________ Kenneth J. Wood President Saturn PCB Design, Inc. * <mailto:[log in to unmask]> [log in to unmask] 2737 Bishop Lane ( (407) 340-2668 Deltona, Fl 32725 fax: (386) 789-2765 www.saturnpcb.com PCB_Design_new -----Original Message----- From: TechNet [mailto:[log in to unmask]] On Behalf Of Mark Larson Sent: Tuesday, August 26, 2008 10:06 AM To: [log in to unmask] Subject: [TN] LGA footprint Hi, been lurking for a few months after not having posted for a couple years. I am wondering if anyone can give a rule of thumb for designing land patterns for an LGA, specifically for a 5mm square x 1.2mm high with rectangular metalization pads ( MEMSic MMC302xM to be exact) Shouldn't this be treated like any BGA, the pad size on the pcb the same size as the metalization on the bottom of the part? LGA do not have "solder balls" like a BGA, so the rule of thumb making the pad 80% of ball size does not apply, and besides this part has .65mm x .35mm rectangular contact, not round. thanks in advance Mark --------------------------------------------------- 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 ----------------------------------------------------- CONFIDENTIALITY This e-mail message and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. 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