Manufacturing of individualized sensors: Integration of conductive elements in additively manufactured PBT parts and qualification of functional sensors

Abstract

AbstractThe growing variety of product variants requires smaller and more complex parts with increasing functionality. Additively manufactured parts with integrated, freely arranged standard electrical components would allow application-specific design and high integration density. Such systems can be used as proximity sensors for industrial applications, acoustic sensors for hearing aids, or ultrasonic sensors for food inspection, as well as integrated analog-to-digital converters for standard sensors or wear detection sensors in tools. Preliminary studies have shown that a hybrid manufacturing process can be used to additively manufacture such geometrically individualized sensors. In the approach chosen here, standard electrical components are integrated into housings produced using the ARBURG Plastic Freeforming (APF) process. The housing material used is a PBT granulate, which is a standard material in the electronics industry. The integrated electrical components are electrically connected using a silver conductive paste and are generated using a jet dispensing valve. Based on the hybrid manufacturing process, it is possible to produce geometrically customizable industrial proximity sensors in one production step. In this publication, various connection options were investigated and design guidelines for the microdispensing of silver paste were derived. In addition, twelve functional sensors were manufactured and subjected to three industrial standard quality tests. Five out of six passed the temperature shock test, three out of four passed the humidity-heat test, and two out of two passed the vibration and shock test. Thus, the proof of concept was principally provided that the investigated connection options are suitable to produce individualized electronic sensors.