[K-4] Design, Process, and Technology for High-performance Chiplet II/3D Integration and Advanced Packaging II

[K-4-02] Failure Analyses and Yield Enhancement of Electroplated Cu Direct Bonding for Heterogeneous 3D and Micro-LED Integration

〇Yuki Susumago¹, Tadaaki Hoshi¹, Chang Liu¹, Atushi Shinoda², Hisashi Kino³, Tetsu Tanaka^1,3, Takafumi Fukushima^1,3 (1. Graduate School of Eng., Tohoku Univ. (Japan), 2. School of Eng., Tohoku Univ. (Japan), 3. Graduate School of Biomed. Eng., Tohoku Univ. (Japan))

Presentation style: Online

https://doi.org/10.7567/SSDM.2022.K-4-02

This paper describes the electroplated Cu direct bonding technology for stacking micro-LEDs on 3D-ICs. Conventional bonding methods using thermal compression bonding with solder or conductive pastes for micro-LEDs have serious problems in fine-pitch interconnection and thermomechanical stress. This paper works on the failure analyses and challenges the yield enhancement of room-temperature micro-LED integration. The metallization yield is greatly improved nearly 100% by optimizing the electroplated Cu direct bonding processes. Finally, 900 pcs. of blue micro-LEDs with a side length of 0.1 mm are interconnected and successfully operated.