Highly Miniaturized Integrated Sensor Nodes for Industry 4.0
Authors: Voges S. , Becker K.-F. , Schütze D. , Schröder B. , Fruehauf P. , Heimann M. , Nerreter S. , Blank R. , Gottwald S. , Hofmeister A. , Schmied M. , Kreitmair M. , Fust R. , Neifer W. , Braun T. , Thomas T. , Schneider-Ramelow M. , Lang K.-D. 
Published: December 2019

Paper Abstract
The PCB 4.0 research project offers the opportunity to take the flexibility, energy efficiency, and resource efficiency of production processes to a whole new level through intelligent control and networking. The development of electronics and sensors, which is among the strengths of small and medium-sized enterprises (SMEs) in Germany in particular, plays a key role here. The integration of sensors into workpieces and systems must be as compact as possible for flexible and efficient data acquisition. Miniaturized radio sensor nodes offer this possibility, but their production and integration currently still pose major technical challenges.
The objective of the research project PCB 4.0 is the creation of a technology platform for the design and manufacture of embedded miniaturized radio frequency (RF) sensor nodes and their integration into production processes. Four dedicated scenarios, that reflect different phases of the product life cycle, demonstrate the performance of the developed technologies - ranging from production to component use - detecting and processing the actual state in the production of industrial electronics in real time.
A maintenance-free Bluetooth Low Energy (BLE) sensor node was developed to report environmental data (e.g. temperature, acceleration) during lifecycle of an Industry 4.0 PCB. The embedded security chip from WIBU-Systems AG, called “CmASIC”, provides asymmetric, cryptographic algorithms and certificates to guarantee the highest level of authenticity during the PCB production process and over the entire product lifecycle.
In addition, a highly miniaturized sensor node (11×10×1.6 mm3) was developed using PCB embedding technology. The node includes an integrated PCB helix antenna, embedded accumulator and a sensor with media access. The embedding technology was transferred to mass production on 610×457 mm2 manufacturing panel size.
To optimize the design flow of sensor nodes, a PCB design tool was created using Altium® Designer interface. This tool's highly efficient interactive and automatic functionalities support all aspects of the PCB design process with embedded components. For device genuineness control, a centralized license management system was used, a tool for generating and deploying certificates to securely track device identities, supporting the industrial production chain. Sensor data and other status information (e.g. wear level, authenticity) are made available via two cloud solutions (Siemens MindSphere and a solution for small and medium-sized businesses by partner Sensorik Bayern GmbH (SBG)).
Demonstrators were developed to support scenarios for future industrial demands. During test runs, the sensor nodes howed the potential to monitor and control the process flow and system lifetime directly at the component level.
The paper describes the technological developments towards miniaturized sensor nodes as well as the integration of those miniaturized SiPs (System-in-Package) into a sensor network. Finally, the application of such sensor networks for smart manufacturing is demonstrated for selected use cases.