Advanced Fan-Out Panel Level Package (FO-PLP) Development for High-end Mobile Application

As high- end mobile products require high-performance, junction temperature of die rises high and I/O count also increases. Therefore, thermal performance improvement and warpage control are becoming more important these days. The most effective way is to increase the die thickness for better thermal conductivity and warpage control. In this paper, we developed the advanced Fan-Out Panel Level Package (FO-PLP) structure with embedded die in the substrate frame. Therefore, the thickness of the die can be flexibly adjusted by selecting the substrate frame. By using this substrate frame, it could be easily fabricated with front RDL (F-RDL) and back-side RDL (B-RDL). It is advantageous for warpage control as the vertical structure can be implemented in a symmetrical structure. The conventional flip-chip package and FO-PLP of same form factor were fabricated to compare the thermal performance and high temperature warpage. In the same package height, die thickness of FO-PLP was increased as 2.6 times compared with conventional flip-chip package. Thermal resistance was measured in JEDEC standards and the high temperature warpage was measured by capturing Moire image. Results showed that the thermal resistance was improved by 24.3% and the high temperature warpage was excellent (FO-PLP x0.3, Flip-Chip package x1, relatively). Moreover, Board-Level Reliability (BLR) of the FO-PLP showed no failure up to TC 700 cycles under -40 similar to 125 degrees C. Through this evaluation, it was demonstrated that FO-PLP can contribute the performance enhancement of high-end mobile products. It is expected that the application range of FO-PLP will be expanded.