Plasma Sprayed Y₂O₃ Coating on C-FRP with Aim of Development of Future Mold Materials for Integrated Circuit Encapsulation

The aim of this study is to improve the releasability of carbon fiber reinforced plastic (C-FRP) molds by depositing a plasma-sprayed Y₂O₃ coating on working surfaces. Composite molds are considered for use in IC encapsulation. To promote adhesion, an interlayer, either copper or gradient yttria, is applied between the substrate and coating. The coatings deposited over gradient Y₂O₃ performed better than coatings applied over copper due to the large reduction in thermal mismatch achieved with a graded thermal expansion coefficient. Preliminary releasability results show that the yttria coatings have high adhesion strength and the potential to uniformly reduce release forces between C-FRP surfaces and epoxy resins.