The Surface Modification Technologies Improving Adhesive Properties at the Interface between Fluoropolymers and Metals

Abstract

In recent years, the direct adhesion of fluoropolymer to other materials has received much attention, especially in micro-electronic field due to their outstanding dielectric properties, flexibility, chemical and thermal stability which are suitable for insulating substrate of print circuit board for providing ultrahighspeed internet. One of the biggest characteristics for fluoropolymers is low surface energy which make it quite difficult to adhere to other materials without any surface modification treatment. Until now, some unique and valuable methods improving adhesive properties of fluoropolymers have been investigated and developed for manufacturing lots of fluoropolymer-based products. In many cases, adhesives are essential to bond fluoropolymers and other materials, even though its surface has been hydrophilized. However, it is requested that the fluoropolymers are directly adhere to the other materials including metals, plastics, rubbers, and elastomers without any glues today, in order to adjust to higher functionalities and environmental regulations which are listed in SDGs. Herein, we review the surface modification technologies from the old wet process basing upon chemical reaction to the later dry process involving several types of plasma treatment, and finally introduce our recent work about plasma-induced surface modification of fluoropolymers and its direct adhesion to profile-free Cu foils.