Improvement of backside emission analysis sample prep process for BGA

Current method of BGA sample preparation repackaging process for backside emission analysis is by applying direct bonding from the exposed gold wire on the bottom of the package to the lead frame of the secondary open top package. The exposed gold wire on the package bottom is achieved through the back grinding process. The very small diameter of the exposed gold wire on the backside of the BGA which is about 1.0 mil in diameter has imposed difficulty during the manual re-bonding process. The re-bonding process requires a skillful person as it requires high precision bonding. A single wire bonding itself may require several attempts in order to form a good bond/ joint on the exposed gold wire. With this scenario we will also be facing more challenges in the future as we are moving towards qualifying thinner wire for production.