ChipletT, A Cost-Effective, High Reliability, Embedded Die Fan-Out Package Based on Multilayer Flex Laminate with Enhanced Thermal Performance

Abstract

Fan-Out Wafer Level Packaging (FO-WLP) technology has been developed in recent years to overcome the limitations of Fan-in WLP (FI-WLP) packages and to add more functionality to WLP. Fan-Out packages expand the WLP market to higher pin count devices and add multiple die System in Package (SiP) capability. In this paper, a novel approach to low cost fan-out packaging based on polyimide flex circuits and wafer level Embedded Die Customization (EDC) is discussed. ChipletT refers to Fan-Out packaging. ChipsetT refers to System in Package developed with WABE (Wafer and Board Level Embedding) technology. WABE technology is based on co-lamination of multi layer polyimide flex wiring and conductive z-axis sintered metal interconnections. Using WABE technology, ultra thin fan-out packages (0.4mm) can be fabricated with lower processing costs, higher throughput and with 3D extendibility. Embedded Die Customization is performed at the wafer level and involves optimization of the die-to-embedding process by using optimized wafer level processing capabilities including polymer processing, copper plating and wafer thinning. Reliability of the ChipletT packages, both component level and board level is evaluated. ChipletT packages show high reliability in component level testing and board level testing (Thermal Cycling and Drop Testing). The thermal performance of ChipletT packages were also evaluated in this study. Thermal resistance parameters θja and θjc were simulated with and without thermal vias for both face up and face down configurations. ChipletT provides a new low cost fan out packaging option with proven component level and board level reliability performance.