Thermal-mechanical Reliability and Package Optimization of a dToF Photon Imaging sensor

As 3D vision sensing technology continues to evolve, direct Time of Flight (dToF) photon imaging sensors are playing an increasingly important role. For the two mainstream sensor packaging forms in the market, this paper compares and analyzes the cavity type package and double-mold package in terms of thermal stress, warpage, and tilt, and explores the important influencing factors that affect their packaging reliability in order to optimize the packaging structure of dToF photon imaging sensors.The results show that after temperature cycling, the cavity type package has better reliability than the double-mold package, with maximum stresses of 113.08 and 334.03 MPa on the substrate and chip, respectively; maximum warpage of 8.93 and 37.1 μm on the cap, respectively; and tilt variation in the range of -3.24139 ~ 0.5863° and -2.8216 ~ 0.9383°. In the cavity type package, the area adjacent to the filter and the cap is the most vulnerable place, and in the double-mold package, the area where the lens meets the chip is the most prone to failure; the trend of stress variation and the warpage result are inversely related; the tilt variation range of the two package structures is similar, and the chip and chip mount adhesive have a great influence on the tilt of both packagest.