Meng, Y.; Gao, R.; Wang, X.; Huang, S.; Wei, K.; Wang, D.; Mu, F.; Liu, X. Direct Bonding Method for Completely Cured Polyimide by Surface Activation and Wetting. Materials2022, 15, 2529.
Meng, Y.; Gao, R.; Wang, X.; Huang, S.; Wei, K.; Wang, D.; Mu, F.; Liu, X. Direct Bonding Method for Completely Cured Polyimide by Surface Activation and Wetting. Materials 2022, 15, 2529.
Meng, Y.; Gao, R.; Wang, X.; Huang, S.; Wei, K.; Wang, D.; Mu, F.; Liu, X. Direct Bonding Method for Completely Cured Polyimide by Surface Activation and Wetting. Materials2022, 15, 2529.
Meng, Y.; Gao, R.; Wang, X.; Huang, S.; Wei, K.; Wang, D.; Mu, F.; Liu, X. Direct Bonding Method for Completely Cured Polyimide by Surface Activation and Wetting. Materials 2022, 15, 2529.
Abstract
Polymer adhesives have emerged as a promising dielectric passivation layer in hybrid bonding for 3D integration while 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 generated hydrophilic groups on the polyimide surface, and the wetting process further introduced more -OH groups and water molecular on the activated polyimide surface. The synergistic process of plasma activation and wetting facilitate bridging polyimide interfaces to achieve bonding, providing an alternative path for adhesive bonding in 3D integration.
Keywords
polyimide bonding; plasma activation; hydrophilic; hybrid bonding; 3D integration
Subject
Engineering, Electrical and Electronic Engineering
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
