Research on Micro-LED Heterogeneous Integration and Reliability Based on Copper Pillar Bumps

作者：Luqiao Yin, Hao Fu, Zhu Yang, Haojie Zhou, Xinyi Wang, Xiaoxiao Ji, Xiuzhen Lu, Jianhua Zhang · 发表于：IEEE Electron Device Letters · 年份：2025 · DOI：10.1109/led.2025.3631919 · 被引用次数：2 · 研究领域：Electronic Packaging and Soldering Technologies、3D IC and TSV technologies、GaN-based semiconductor devices and materials

The interconnection structure based on copper pillar bumps is first used in Micro-LED in this letter. Relying on the high melting point of Cu, this structure can effectively reduce the risk of bump bridging in Micro-LED devices during bonding process, which can adapt to the increasingly small interconnection spacing of Micro-LED. A Ni barrier layer is added between Cu layer and Sn layer in order to enhance the long term reliability of Cu-Sn bumps. The performance and reliability of Cu-Sn bump and Cu-Ni-Sn bump bonded devices are investigated. The results confirm that copper pillar bumps are a viable and effective solution for micro-LED interconnect applications. In addition, Ni barrier layer significantly enhanced the long term reliability of Micro-LED device. Cu-Ni-Sn bump bonded device shows weak advantages in brightness, optical stability and shear strength, apart from the small increase in series resistance.