Direct Bonding Method for Completely Cured Polyimide by Surface Activation and Wetting

Materials

Dahai Wang¹  Xinhua Wang¹  Sen Huang¹  Ying Meng¹  Xinyu Liu¹  Runhua Gao¹  Ke Wei¹  Fengwen Mu² 

[1] High-Frequency High-Voltage Device and Integrated Circuits R&D Center, Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China;SABers Co., Ltd., Tianjing 300450, China;

关键词: polyimide bonding;    plasma activation;    hydrophilic;    hybrid bonding;    3D integration;   

DOI  :  10.3390/ma15072529

来源: DOAJ

【 摘 要 】

Polymer adhesives have emerged as a promising dielectric passivation layer in hybrid bonding for 3D integration, but they raise misalignment problems during curing. In this work, the synergistic effect of oxygen plasma surface activation and wetting is utilized to achieve bonding between completed cured polyimides. The optimized process achieves a void-less bonding with a maximum shear strength of 35.3 MPa at a low temperature of 250 °C in merely 2 min, significantly shortening the bonding period and decreasing thermal stress. It is found that the plasma activation generates hydrophilic groups on the polyimide surface, and the wetting process further introduces more −OH groups and water molecules on the activated polyimide surface. The synergistic process of plasma activation and wetting facilitates the bridging of polyimide interfaces to achieve bonding, providing an alternative path for adhesive bonding in 3D integration.

【 授权许可】

Unknown