Challenge of vacuum molded flip chip packaging technology

To be the solution of higher throughput, uniform outline and level up reliability performance of mature capillary underfill packaging, molded underfill technology is studied by assembly houses, equipment vendors and material manufactures for years and is expected to be the major assembly method of flip chip package in the future. Vacuum molding flip chip packaging technology is one developed by lots of molding equipment vendors from various molded underfill theories, and the key issues are the uncompleted fill under the die and the flush at vacuum position(s). Finer filler (less than 10 μm particle size) compound is used for the small gap between chip and substrate & the clearance of flip chip bumps, but we still need to ensure that there is no air be trapped under the die during molding process. Vacuum parameter and position are also very important to avoid the uncompleted fill and material flush from air vent areas. Siliconware is now developing such technology as an alternative solution of capillary underfill flip chip packaging. The test vehicle and vacuum processing technology development by tuning the parameters and modifying the mold chase design will be simply introduced here, and the reliability test is going to confirm the package performance.