Characteristics Of The Pbo-Bi2o3-B2o3-Zno-Sio2 Glass System Doped With Pb Metal Filler

We investigated the effect of Pb-metal filler added to a hybrid paste(PbO-Bi2O3-B2O3-ZnO glass frit and Pb-powder), for joining flip-chip sat lower temperatures than normal. The glass transition temperature was detected at 250 degrees C and the softening point occurred at 330 degrees C. As the temperature increased, the specific density decreased due to the volatility of the Pb-metal and boron component in the glass. When the glass was heat-treated at 350 degrees C for 5 min, XRD results revealed a crystalline Pb4Bi3B7O19 phase that had been initiated by the addition of Pb-filler in the hybrid paste. The addition of the Pb-metal filler caused are action between the Pb-metal and glass that accelerated the formation of the liquid phase. The liquid phase that formed, promoted bonding between the flip-chip substrate sat lower temperature.