A Warpage Investigation for a Large Panel-sized Interposer with Embedded Dies

The 2.xD packaging have been an attracting technology for high-performance computing such as generative AI. We have addressed combining organic interposer and embedded bridge die in large glass panel (320 x 320 mm and 515 x 510 mm) to balance the manufacturing costs and performance in 2.xD package. In general, warpage control has been a critical issue in the large panel size processes and we evaluated the warpage after molding process with different material combination such as changing glass and molding material type with different coefficient of thermal expansion (CTE) value. The warpage amount after a molding process mainly depended on the CTE mismatch between glass and molding material. After a molding and grinding process, an organic re-distribution layer (RDL) was fabricated on the embedded dies with the optimum warpage control including not only the material selection but also the control of Cu plating area and the mounted Si chip volume. The 2.xD chip embedded interposer with Cu wirings of L/S=10/10 to 5/5 μm, finally, were fabricated successfully on the embedded dies using semi-additive process (SAP).