Physical and Thermal Characteristics of the Advanced Package with Glass Core Substrate

In recent years, substrate size is increasing as the progress of heterogeneous integration, and it is known that the reduction of chip warpage is one of the most important demands for advanced packages. However, it becomes difficult that existing organic packages satisfy the demand. To solve the problem for our future applications, we have developed glass core substrates focusing on the excellent properties of glass. Our glass substrate package showed small chip warpage change in temperature and moisture absorption dependence compared to low-CTE organic substrate package. Developed glass substrate package also satisfied enough reliabilities for our general uses. In addition, we evaluated thermal cycle endurance of glass core substrate, and confirmed the occurrence of glass failure mode known as “SeWaRe”. We also showed the influence of build-up thickness on “SeWaRe”, which indicated that the reduction of stress from build-up layer is the key factor to expand reliability margin of glass core substrates.