CO2-assisted thermal fusion bonding of heterogeneous materials by use of surface nano-pillars

Abstract

Microchip components may involve different polymeric materials for integrated functions, and the thermal bonding of heterogeneous materials is a challenge. This study is devoted to the bonding of polycarbonate (PC) and polymethacrylate (PMMA) materials. For conventional thermal bonding of PC and PMMA, the temperature must be above 150 C. CO2 is used as a plasticizer to lower the bonding temperature to 90 C. CO2 also serves as a pressurizing agent to provide uniform bonding pressure. To further improve the bonding strength, surface nano-pillar structures are fabricated on PC before binding it with PMMA. Because of the nano-pillar structures, the contact areas significantly increased, and the structural inter-lock further increased the strength after bonding thereby yielding a bonding strength of 1.20 MPa. © 2013 The Author(s).