In-Mold Electronics (IME) is a manufacturing method that integrates printed decorations and electronic circuitry with thermoforming and injection molding processes. The method enables the production of ergonomic, lightweight and durable parts through cost-effective processes that require less assembly. Herein, the effect of circuit shape on line-width change by thermoforming was investigated through experiments and analysis based on the K-BKZ nonlinear viscoelastic model. Two circuit shapes, a horseshoe and a coil, were proposed and their line widths after thermoforming were measured and compared to that of a straight line shape. In the horseshoe-shaped circuit, the line width decreased as the radius increased due to the influence of vertical stretching caused by thermoforming. However, the effect of the angle on the line width was insignificant. In the coil-shaped circuit, the width of the line decreased as the pitch increased. However, as the amplitude increased, the line width also increased, but the effect was not significant. For the circuit shapes of the straight line, horseshoe and coil shapes, the rate of change in line width was 4.4, 0.4, and 0.2%, respectively. After conducting research, it was found that the coil-shaped circuit is more effective in minimizing line-width change caused by film thermoforming.

As a heating method for RHCM (Rapid Heating Cycle Molding) various heating technologies such as high frequency induction heating, IR heating, gas heating, and high temperature steamare applied, but these methods are not satisfying high productivity due to low energy efficiency. Research has been actively conducted on RHCM based on planar heating elements with high heating efficiency, such as carbon nanotubes, which are applied. To apply the CNT web film to the RHCM, a heating element must be applied inside the injection mold and power must be applied. As electricity is directly applied to the CNT web film to generate heat, all mold parts in contact with the CNT web film must be insulated, and high heat transfer is required for rapid heating performance. Thus, in this study, a multi-layer structure mold module for insulation and high heat transfer was designed to enable rapid heating by applying a CNT web film as a heat source. To this end, we intend to present a research direction for the commercialization of rapid heating molds, by identifying the main variables of rapid heating through heating experiments by the mold metal and insulator materials, and reflecting them in the mold design.