SLIM (TM), High Density Wafer Level Fan-Out Package Development with Submicron RDL

A novel HD-FO package platform was introduced with a hybrid RDL structure. An HD-FO package with hybrid RDL could enables higher routing density and multi die construction in a planner configuration. The 1-µm and submicron RDL wafers were fabricated at a foundry and then the essential parts of the inorganic RDL were integrated with Amkor's internal organic RDL process making a hybrid structure. Also, the vertical interconnection on a hybrid RDL made 3-dimentional package construction. Key processes including via reveal, top die attach, and vertical package stacking were successfully demonstrated. Technical challenges in HDFO package development was discussed as well as the reliability performance results both in the package and at the board level.