Hi Technetters, Recently, I have attached GaAs die on a CVD diamond substrate using 80/20 Au/Sn eutectic preform. After the die bonding at 280 C, we found cracks (mostly 90 degrees and 45 degrees cracks) on the surface of the GaAs during the inspection. We suspect that it is due to TCE mismatch or thermal shock. We are thinking about using different die attach material that requires lower temperature process. Anyone has advise, suggestion, or any experience similar to this? Thanks. Jong S. Kadesch Sr. Engineer NASA-GSFC/Orbital Sciences Corp. 562/Component Technologies and Radiation Branch Greenbelt, MD 20771 tel:(301)286-2785 fax:(301)286-1695 ############################################################## TechNet Mail List 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 web site (http://www.ipc.org/html/forum.htm) for additional information. If you need assistance - contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ##############################################################