Nanostructured Alumina Coatings forRoomTemperature Processability ofAuBonding Wires

Wirebonding isthemostcommontechnology toconnect baredies onhybrids. Forsuchapplications, e.g. automotive applications orsensor modules, highly reliable Au/Auinterconnections arepreferred. Butthe standard ball /wedgebondprocess forAu-wires requires temperatures over120°C,whichisaserious disadvantage whenconnecting temperature sensitive devices. Oneofthemostpromising solution to overcome this problem isalumina coated Aubonding wires. Inthepresent workwehavestudied the characterisation andoptimisation ofcoated goldwires forultrasonic wedgelwedge bonding, including the optimisation ofwirebondprocess parameters, reliability testing andmaterial characterisation ofthe metallurgical state ofthewirebonds.