Double Side SiP of Structure Strength Analysis for 5G and Wearable Application

The wearable devices demand small form factor and drive more function such as heartbeat detection, electrocardiogram detection functions, and sensors. Wearable device has become a small medical data center. Therefore, the design trend of wearable products requires smaller module size, multi-IC and component integration, low power consumption and better heat dissipation performance. The module size of the original Single Side SiP (System in Package) products cannot meet the next generation product, and Double Side SiP structure is expected to provide solutions for more diverse applications of wearable products in the future. The Double Side SiP structure can provide higher integration and performance. Package can be reduced to about 40~60% lighter and thinner to improve power supply efficiency and to reduce noise emission. This paper will demonstrate Double Side SiP of PKG structure with strip grinding process to check PKG die strength as a function of thickness. By using simulation and experiment, the ELK stress performance with 3-point test methodology is studied to select the suitable Double Side SiP structure for end product of board level manufacturing process. From electrical integration point of view, the shorter signal transmission path is required to get good electrical performance (SI: Signal Integrity & PI: Power Integrity) than a side by side flip chip base structure. The Double Side SiP module can provide an advanced solution to address the module size, cost, performance, and time-to-market requirement for 5G and wearable products in near future.The performance verification will be confirmed by simulation and measurement. The reliability testing verification includes the TCT, HTSL and u-HAST (Temperature Cycle Test, High Temperature Storage Test, un-bias HAST) results of the Double Side SiP structure. Finally, this paper summarizes Double Side SiP structure and feasibility data for future 5G and wearable devices application.