Evaluation of different additive manufacturing technologies for MIDs in the context of smart sensor systems for retrofit applications

Industry 4.0 describes a concept where machines and systems are smart and interconnected. Production processes can be monitored, optimized and the failure of individual components can be predicted. While it may be possible for big companies to plan a new, smart and interconnected production facility on the "greenfield", this is hardly realistic for small and medium-sized enterprises. Due to the long deployment duration of production facilities, alternative approaches must be identified to upgrade the existing machines and systems with sensor technology, software and IT connectivity. This process is called retrofitting. Nevertheless, no universal solution exists on the market that meets the requirements for all use-cases. Moreover, small and medium sized enterprises in general do not have the abilities and the knowhow to develop and manufacture these complex and tailored solutions in small lot sizes, which is an essential requirement for retrofitting. Standard shaped sensors cannot be used due to the individual installation situation in the machines. 3D Mechatronic Integrated Devices (MID), a generic term for distinctive spatial integration technologies breaks through the known limitations of printed circuit boards and enables the development of new highly innovative products. The most common form to produce MIDs are injection molding based. While this production technology is state of the art for high quantities, it is too expensive, time-consuming and complex for smaller batch sizes. Additive manufacturing technologies (AM) provide an attractive approach to this problem. AM allows a faster reaction to product changes, is more cost efficient in small quantities and allows a higher degree of freedom in product design. The combination of MIDs and AM not only fulfils the requirements regarding costs and flexibility but also enables the creation of new, highly individual and electrically functionalized products in general. In the context of this paper, three additive technologies are evaluated with respect to their applicability against the background of different retrofitting applications. A focus lies on the creation of 3D shaped circuit carriers. Based on different use cases in the context of retrofitting applications the benefits as well as the restrictions are pointed out and their utilization is evaluated.