Daan, Stack two defect marking arrows under each corner (should equal 0.020" standoff). Remove them after reflow. Thanks Ryan Grant Advanced Technology Engineer MCMS (208) 898-1145 [log in to unmask] > -----Original Message----- > From: d. terstegge [SMTP:[log in to unmask]] > Sent: Tuesday, October 10, 2000 8:25 AM > To: [log in to unmask] > Subject: Re: [TN] Heavy BGA's, now it's fine-pitch ! > > Hi Jim, > > Thanks for the suggestion. Any idea on how thick such a spacer should be, > and how to apply it ? Like I mentioned, trial and error is no option for > this project. > > Kind regards, > > Daan Terstegge > SMT Centre > Signaal Communications > Unclassified mail > Personal Website: http://www.smtinfo.net > > >>> "Marsico, James" <[log in to unmask]> 10/10 2:08 pm >>> > How about using a temporary spacer under each corner? > > Jim M. > > > -----Original Message----- > From: d. terstegge [SMTP:[log in to unmask]] > Sent: Tuesday, October 10, 2000 9:59 AM > To: [log in to unmask] > Subject: [TN] Heavy BGA's, now it's fine-pitch ! > > Hi Technet, > > I need your advice on this one: > Some time ago there was a discussion about soldering problems with > partnumberTMS320C6201GJC200 of Texas Instruments. It's a 1.27 mm pich BGA > with a heavy heat-slug on top. The weight of the heat-slug makes the > solderballs collapse a little too much, resulting in solder bridges. > Now I've got to assemble some boards with similar parts, but with > a > much smaller ballpitch of only 0.8 mm. > No problem for the ordinary type BGA's, but with the heatsink I'm > starting to feel uncomfortable. For the record: it's TI's part > numberTMX320C6203GLS. > I've got to build two boards, and all I've got is two components. > No > trial and error possible...... > If anyone of you have experience or thoughts about this, please > let > me know. > > Kind regards, > > Daan Terstegge > SMT Centre > Signaal Communications > Unclassified mail > Personal Website: http://www.smtinfo.net > > > > > -------------------------------------------------------------------------- > -- > ----- > TechNet Mail List provided as a free service by IPC using LISTSERV > 1.8d > To unsubscribe, send a message to [log in to unmask] with following > text in > the BODY (NOT the subject field): SIGNOFF TECHNET > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for > additional > information, or contact Keach Sasamori at [log in to unmask] or > 847-509-9700 ext.5315 > > -------------------------------------------------------------------------- > -- > ----- > > -------------------------------------------------------------------------- > ------- > TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF TECHNET > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for > additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 > ext.5315 > -------------------------------------------------------------------------- > ------- > > -------------------------------------------------------------------------- > ------- > TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF TECHNET > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for > additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 > ext.5315 > -------------------------------------------------------------------------- > ------- --------------------------------------------------------------------------------- TechNet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF TECHNET Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------