Bev, You are back. Damn good to see from you again and gainfully employed whether self or otherwise. Not much data difference to 500 thermal and/or mechanical cycles to failure concerning solder paste or paste flux. We know the closer we get to columns instead of balls/pumpkins the better the long term reliabilty. CCGA's go on forever as IBM would put it and as evidenced by our testing at Celestica/Cray. Don't have good/much data concerning solder paste as "bigger" solder globs. Other factors come back to haunt. Voiding, or not, and where/how many, in what locations still out for comment but not of too much concern when surface solderability conditions right together with all other factors (the same drill as profiles, paste, solder termination area coating/plating, wetting, TCE, IMC, etc.) Had no reported field failures at HP with BGA's of all pitches, CSP's, uBGA's. Ho internal rejects for CCGA's at Celestica/Cray/SGI but no reliable field data concerning returns. Some data from HAST/HALT but must be considered as a function of stand still super computer stuff with little environmental change, thermal differences, or mechanical shock. Still, columns approximate wires and are very compliant absorbing most CTE mismatch unlike BGA's. And on it goes. Keep the cards, CD's, and letters coming. If exceeding 1600, I'll just pace myself over the next 1600 days, weeks, months, or years as required but no worries so far. Earl Moon Proof Of Design --------------------------------------------------------------------------------- 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 To temporarily halt delivery of Technet send the following message: SET Technet NOMAIL Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives 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 ---------------------------------------------------------------------------------