Over-molding of two-dimensional curved shape using polyimide copper cladding foil

Abstract

In many applications, including automotive, wearables, and health sectors, the over-molding of flexible electronics structures into plastics has been commonly used. A polyimide-copper (PI/Cu) electronic circuit embedded in a thermoplastic material using an injection molding process is the basis of this work. The electronic circuit is a PI substrate consisting of copper interconnections where lead-free solder and under-fill material are used to assemble the electronic components. In previous work, the integration of electronics using a mold with a two-dimensional (2D) flat shape and the optimization of materials, including the over-molding material and the type of PI/Cu foil used, were studied. In this study, a 2D curved mold with an arc length curvature of 205 mm is used to investigate its effect on the resistance of 0-ohm resistors. The circuit design and the component mounting place are considered to be the parameters in this study. Moreover, the data obtained before and after over-molding from the measurements of the assembled resistors showed the effect of the over-molding on the electronics in the curved mold.