HIPS

The objective of the HIPS (High Performance Sensors) growth core is the development and joint marketing of novel, robust, highly integrated sensors based on a unique combination of silicon technology and ceramic multilayer technology (SiCer). The silicon is permanently bonded to the ceramic substrate at wafer level. By combining the advantages of both technology worlds, a new, unique technology platform is created for a variety of different sensors with a wide range of applications.

In the HIPS alliance, 12 regional companies, 7 research institutions and 5 associated partners from the Thuringian technology triangle of Jena/Hermsdorf-Erfurt-Ilmenau are working together. In this alliance, the partners are able for the first time to offer comprehensive solutions for high-performance sensors that are not yet available worldwide in SiCer form. The objective is to develop innovative materials, processes and components on this new technology platform, which can be used in a variety of ways and thus create the prerequisite for the broad development of new fields of application in sensor technology (Fig. 1).

Basic procedure for the production of a SiCer system (Fig. 2):

After pre-processing of both substrate layers (silicon and LTCC green films), they are aligned to each other and stacked. Subsequent lamination and sintering (900 °C) results in a quasi-monolithic composite substrate (SiCer). This can then be further processed using MEMS technologies. A subsequent processing with technologies of packaging and interconnection uses the capability/property of the LTCC as a ceramic circuit carrier to integrate parts of the sensor electronics (primary electronics) directly at the transducer (short, vertical wiring paths). At the same time, housing can be implemented if required.

This provides a material composite in which a variety of materials as well as micro- and nanostructures can be monolithically integrated into the LTCC or onto the silicon side of the substrate. The thermal adaptation of the system thus allows both the use of high-temperature processes in manufacturing and the use of the finished system under high-temperature conditions up to at least 600 °C. This results in the following advantages for SiCer sensors:

- High functional integration (multi-sensor properties) by linking silicon and LTCC technology - Robustness due to carrier function of LTCC ceramic and high bond strength between LTCC and silicon: up to 5000 N/cm² - Inertness due to gas-tight bonding interface (He-density <1.1-10-8 mbar-l/s) - Compatibility with thin film and MEMS processes (standard equipment) - Cost-effective due to wafer-level packaging - Miniaturization due to 3D design of sensors - Integratability of fluid channels - Temperature resistance due to inorganic materials and robust electrical and thermal vias (up to at least 600 °C) - Easy thermal management due to extreme thermal conductivity difference of the composite substrate: Silicon: 150 W/(m-K), LTCC: 5 W/(m-K).

Three closely linked collaborative projects are being worked on as part of the research activities at the TU Ilmenau:

VP1: Development of SiCer-based technologies for applications in high-performance sensor technology - SiCer-based technologies.

This subproject involves research, further development and evaluation of the SiCer platform with the aim of developing new materials and functional elements for high-performance sensor applications and raising the processes required for this to a level at which the implementation strategy of the industrial collaborative project partners can be fulfilled. Within the consortium, the TU Ilmenau has the highest level of experience in the SiCer composite technology and will drive the technology transfer to the partners.

VP2: Development and construction of SiCer-based, multifunctional sensor systems for the application area "liquid sensor technology".

The aim of this sub-project is to transfer and demonstrate the application of SiCer technology in the design and construction of liquid sensors. The different materials, fabrication technologies, structural and functional elements of the SiCer platform are to be investigated and applied for different topic areas (TS) with respect to their properties, application potentials and scalability for "high-performance liquid sensors". In this subproject, there are three main topics that will be addressed, each representing different application examples for multifunctional SiCer sensor systems in the field of liquid sensing:

- SiCer multi-λ sensor for water monitoring - SiCer moisture sensor for aggressive environments - SiCer impedance sensor for flow cytometry and biofilm monitoring.

VP3: SiCer-based transducers for gas sensing applications

The subproject includes the development, technological implementation and evaluation of SiCer-based sensing elements for gas sensing applications. Specifically, three prototypical applications for a structure in the SiCer composite substrate technology are to be implemented first separately from each other and then united in a sensor demonstrator. The challenge in the joint project lies in the strongly differing specifics of the individual prototype applications infrared sensor, pressure sensor and temperature sensor. In the technological implementation of the sensor element, different processes and process sequences have to be applied in each case, which could possibly influence each other or, in extreme cases, exclude each other (e.g. high-temperature processes that cause piezoelectric strain sensors to drift away by diffusion).

Subproject leader: Univ.-Prof. Dr.-Ing. Jens Müller
Scientific assistants: Dipl.-Ing Michael Fischer, M. Sc. Cathleen Kleinholz
Project duration: 09/2019 - 12/2022
Project executing organization: Forschungszentrum Jülich GmbH Funding: BMBF - Federal Ministry of Education and Research

Partner: Institute for Bioprocess and Analytical Measurement Technology e.V. (IBA) Heiligenstadt, CiS Forschungsinstitut für Mikrosensorik GmbH (CiS) Erfurt, IFU GmbH (Lichtenau), Ernst-Abbe-Hochschule Jena (EAH) Jena, Friedrich-Schiller-Universität Jena (FSU), Fraunhofer-Institut für Keramische Technolog. und Systeme (IKTS) Hermsdorf, LUST Hybrid-Technik GmbH (LHT) Hermsdorf, Micro-Hybrid Electronic GmbH (MHE) Hermsdorf, Micro-Sensor GmbH (MSE) Hermsdorf, Siegert Thinfilm Technology GmbH (STFT) Hermsdorf, VIA electronic GmbH (VIA) Hermsdorf, 5microns GmbH (5M) Ilmenau, Ilmsens GmbH (ILSN) Ilmenau, IL Metronic Sensortechnik GmbH (ILM) Ilmenau, Institut für Mikroelektronik- und Mechatronik-Systeme gGmbH (IMMS) Ilmenau, Kompass GmbH (KOM) Ilmenau, UST Umwelt Sensor Technik GmbH (UST) Geschwenda, LLT Applikation GmbH (LLT) Ilmenau

Associated partners: Osyso GmbH (Osyso) Jena, CMOS-IR GmbH (CIR) Erfurt, Landesentwicklungsgesellschaft Thüringen mbH (LEG) Erfurt, JenaBatteries GmbH Jena, X-FAB MEMS Foundry GmbH Erfurt