Process Recipes and Performance of Printable Formable inks for In-Mold Electronics Applications

In-mold electronics (IME) is a new manufacturing process that combines printed electronics with film insert molding to make electronics-integrated plastic components. Printing, thermoforming, and injection molding are all part of the IME process. The printed circuit deforms during the thermoforming process, resulting in a change in the electrical resistance of the circuit; hence, the thermoforming process is one of the critical processes that affect the performance of the IME product. IME has been used in automobile components, consumer electronics, household appliances, and other applications. A customized user interface is required for various automotive, industrial electronics, and consumer technology applications to manage or monitor the system. There is growing interest in developing flexible and stretchable electronics with functionality and performance under strain when bent, stretched, and deformed. With the growing demand and benefits of the technique, there is a tremendous amount of research being conducted in the IME in terms of the effect of deformation on conductors [1], design optimization of In-mold [2], and software developed for 2D to 3D structural design [3]. There is still a lack of standard design strategies to prevent the over-deformation of printed circuits. This work examines process-recipes and process-performance interactions for thermoforming the plastic film in conjunction with printed circuits. The mold was created with the human interface in mind for automotive applications. The influence of trace profile has been studied under various elongation and thermal load conditions. Electrical and mechanical performance has been quantified under Long-term storage, LTSL, and HTSL. Using optical analysis, the failure was identified from visual data.