The overall aim of the project was to strengthen the medical semiconductor value chain by developing new tools, methods, and processes for volume production.
The three-year project included partners comprising of leading companies from the fields of electronics packaging, optics, and photonics, together with equipment manufacturers and medical technology experts. With a total budget of EUR 34 million, it was funded by ECSEL JU (Electronics Components and Systems for European Leadership Joint Undertaking) as part of the Horizon 2020 EU funding programme.
Würth Elektronik Circuit Board Technology was involved in three use cases:
The first was a hybrid panel-level packaging process that was developed for use in a thermal imaging camera. Printed circuit boards formed the basis for the assembly and connection technology of the system-in-package (SiP). The main areas of development were printed circuit board technology, wire bonding and encapsulation of large optical chips.
A second use case was a catheter equipped with accelerometers to measure contractions of the heart. Würth Elektronik Circuit Board Technology was involved in the design of the circuit boards and production of the substrates. To this end, it developed ultra-flexible and rigid-flexible stack-ups which were designed with the project partner OSYPKA AG, and the printed circuit boards were manufactured based on skin-friendly substrates.
Würth Elektronik Circuit Board Technology also participated in the development of an intelligent patch (smart patch) for cardiac monitoring.
This consisted of two systems – a mini-patch (three electrodes, short-term monitoring) and a maxi-patch (six electrodes, longer, steady-state monitoring). Würth Elektronik focused on designing the layout of the stretchable substrates and manufacturing them.
This project has resulted in a completely new approach to integration, based on a stretchable printed circuit board made of thermoplastic polyurethane (TPU).
It was possible to make this using standard PCB production techniques, which deployed many of the advantages of conventional PCB technology, such as assembly of components using pick-and-place machines. This advantage was exploited by integrating the electrical functions into a dual system-in-package (SiP) design that could be mounted directly on the flexible/stretchable PCB.
Printing the electrodes directly on the flexible printed circuit board and integrating all the electronics into a textile substrate represent crucial advances in the development of medical patches for monitoring bodily functions.
The high degree of miniaturisation and tight integration resulted in a very unobtrusive form factor, while the stretchable PCB provided a very pliable, biocompatible substrate.
In addition to Würth Elektronik Circuit Board Technology, other partners, including Fraunhofer IZM, Fraunhofer ENAS, Interuniversitair Micro-Electronica Centrum (IMEC) and Precordior OY played an important part in the implementation of this use case.
“Through the work on the APPLAUSE project, we have taken significant steps forward in the development of complete medical systems and, in particular, close-to-body applications. This is down to the synergies and excellent collaboration between the partners within the consortium. Discussions are currently being held with some of the project partners on finalising the development after the project has been completed with the clear aim of moving on to industrial production,” concluded Dr. Alina Schreivogel, Head of the Research Center at Würth Elektronik Circuit Board Technology.
