Performance and Reliability Comparison of Thermoformed, Screen-Printed Structures on Polycarbonate and High-Impact Polystyrene Substrates Under Sustained High Temperatures for In-Mold Electronics

Abstract In-mold electronics (IME) offers a path toward reducing the carbon footprint in automotive platforms through weight reduction. This technology enables the integration of human–machine interfaces directly onto automotive surfaces using additive printing processes. Among these processes, screen printing is a promising method due to its suitability for large surface areas and high throughput efficiency. This paper sets out to evaluate and compare the electrical and mechanical performance of additively screen-printed, thermoformed circuits on polycarbonate (PC) and high-impact polystyrene (HIPS) substrates under prolonged high temperatures. The research aims to characterize the long-term reliability and stability of these circuits under significant thermal stress and to analyze their failure modes and mechanisms. The methodology involves screen printing two types of test structures—traces with pads and circuits—on both PC and HIPS substrates. In this paper, results are presented on surface-mount device (SMD) attachment of components on IME circuits. The interaction of high-temperature processing with circuit performance has been studied.