John: We routinely use 27X27, 37.5X37.5 and 41x41 BGA's. We use solder paste, no glue, in the process without problems, and the BGA's are machine placed. When profiling, we had to drill a small hole in the center of the BGA pattern on the board and attached a thermocouple by coming in from the backside of the board. The balls count from 352 up to 600+ in this manner. By the way, all BGA's have, by definition, balls (BGA=Ball Grid Array). > Bill Davis, Ph.D. > Diamond Multimedia Systems > Senior Scientist > Tel. 408.325.7868 > Cell. 408.888.5650 > e-mail: [log in to unmask] > > -----Original Message----- From: John Chandler [mailto:[log in to unmask]] Sent: Wednesday, January 13, 1999 6:50 AM To: [log in to unmask] Subject: [TN] BGA and profiling We are getting into doing BGA's. Just a 27 by 27 overall dimension component, with pitch of 1.27 with 20 rows & columns, with balls. Not a complex part by any means. Our IC placement machine picks up, recognizes and places great. Been told that since the part is spec'ed out to be with balls, that it is either a hand place deal with a special machine or use glue dots on the masking of the PCB, to hold the component in place during reflow. No solder paste using a screen printer required. My questions are does anyone use solder paste and a screen to place BGA's with or without balls? Where should the thermocouples be placed to get the proper reflow profile? Thanks in advanced. John Chandler ITRON 2818 N. Sullivan Road P.O. Box 15288 Spokane, WA 99215 [log in to unmask] Voice (509) 891-3343 Fax (509) 891-3355 ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################ ################################################################ TechNet E-Mail Forum provided as a free service by IPC using LISTSERV 1.8c ################################################################ To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TechNet <your full name> To unsubscribe: SIGNOFF TechNet ################################################################ Please visit IPC's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################