RE: [TN] Okay, all you real smart guys.........John, With this assembly, I don't have a "profile", fully loaded, PCB to play with. My thought is this (theory only): Let's say I have a board that has only 20 BGAs, nothing else on it, and they are all the same size, package, etc. If I run a bare board and get a peak temp of 240 and time over liquidus of 45 sec. then I run a board with half of the BGAs, 10 of them, and I get a peak temp of 230 and a time over of 40 sec., I could then surmise that with a totally populated board, all 20 BGAs on it, would yield a peak temp of 220 with a time over of 35 sec. This wouldn't be totally accurate...there are other factors, but I would get in the ballpark (since baseball crept in this). If I lost 10 degrees peak and 5 sec. over liquidus per 10 components, I could follow this theory to determine the results with all 20 components. (?) Jason Gregory Manufacturing Engineer Innova Electronics (281)653-5593 (281)653-5594 fax (281)212-0844 cell [log in to unmask] -----Original Message----- From: John Burke [mailto:[log in to unmask]] Sent: Thursday, September 29, 2005 4:33 PM To: 'TechNet E-Mail Forum'; 'Jason Gregory' Subject: RE: [TN] Okay, all you real smart guys......... OK, I just got back from vacation and am not yet "with it", but my question is why on earth would you want to know? It is obviously not for shipping since you do not want the board weight. It can't be for RoHS since that is calculated at the homogenous material level. Do you have yet another regulatory requirement that we are all about to be subjected to?? Do tell, John ------------------------------------ Avanex John Burke Senior Manager RoHS Compliance [log in to unmask] 40919 Encyclopedia Circle Fremont CA 94538 tel: 510 897 4250 fax: 510 979 0189 mobile: 510 676 6312 ------------------------------------ -----Original Message----- From: TechNet [mailto:[log in to unmask]]On Behalf Of Jason Gregory Sent: Thursday, September 29, 2005 12:42 PM To: [log in to unmask] Subject: [TN] Okay, all you real smart guys......... Can someone point me in the right direction on determining mass of components of a PCB, knowing: the weight of a bare PCB the weight of a populated PCB number of terminations etc. Who knows the formula? TIA Jason Gregory Manufacturing Engineer Innova Electronics (281)653-5593 (281)653-5594 fax (281)212-0844 cell [log in to unmask] --------------------------------------------------- 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 -----------------------------------------------------