Process-Performance Interactions Under Exposure to Sustained High Temperature for Additively Manufactured Electronics and SMT Assembly With Low-Temperature Curable Adhesives

Abstract

Abstract Rapid progress in technology necessitates an in-depth understanding of the enduring reliability of flexible printed circuitry constructed using different connecting materials. The adaptability of flexible printed circuits and their potential applications in a wide range of electronic devices, from automotive systems to wearable electronics, has garnered substantial interest in recent years. Thermal aging is an important factor that might potentially compromise the structural integrity and performance of electronic assemblies used in real-world applications. The reliability of flexible printed circuit assembly, particularly the bonding materials employed, is critical to the effective integration of flexible printed circuits into various applications. To gain a better understanding of the adhesive’s reliability under thermal aging, this study intends to carefully examine the effects of thermal aging on flexible printed circuitry. The objective of this study is to fill a gap in the literature by thoroughly investigating how thermal aging affects flexible printed circuit assemblies that are fabricated with room-temperature curable adhesives and high-temperature curable adhesives. This paper investigates processes aimed at achieving interconnects suitable for room-temperature processes, along with the use of water-based inks in printed electronics. The research delves into the examination of electrical performance and reliability tests within functional electronic circuitry. A comparison is made between the performance of low-temperature processable interconnects, coupled with water-based inks, and high-temperature processable interconnects for both test designs: individual components test and functional circuit test. The study includes the realization of a differentiator circuit through aerosol jet printing, employing low-temperature interconnects for component attachment. The circuit’s response is then compared with the simulated output. Finally, both the fabricated circuits are subjected to a thermal aging test for 1000 hours at a temperature of +85°C.