Title :
Thermocompression joining of copper to copper for TAB
Author_Institution :
Nat. Semicond. Corp., Santa Clara, CA, USA
Abstract :
A copper-to-copper joining process was developed which could consistently give bond pulls in excess of 50 grams. The key to the process was found to be the cleaning process and the control of the punch geometry. This process was put into production at several million parts a month. The key to the success of the process was found to be control of the inside edge of the punch. The inner edge had to be chamfered in a controlled manner. During the bonding process, the punch tends to wear out. Hence, the punches were changed every 100000 bonds.<>
Keywords :
copper; lead bonding; surface treatment; Cu-Cu; bond pulls; bonding process; cleaning process; punch geometry; thermocompression joining; Assembly; Bonding processes; Cleaning; Copper; Costs; Gold; Lead compounds; Oxidation; Plastics; Temperature;
Conference_Titel :
Electronic Manufacturing Technology Symposium, 1988, Design-to-Manufacturing Transfer Cycle. Fifth IEEE/CHMT International
Conference_Location :
Lake Buena Vista, FL, USA
DOI :
10.1109/EMTS.1988.16146
