Fraunhofer Institute for Electronic Microsystems and Solid State Technologies EMFTElectrical connections in mechatronics and drive technology, as well as in mechatronic systems, are subject to increasing demands in terms of performance, service life and installation space. As part of the PCB Direct Contact research project (T-1753), Fraunhofer EMFT investigated PCB direct contacting systems for demanding application conditions. PCB direct contacting, in which the printed circuit board itself serves as an active contact partner, represents an economically interesting and space-saving alternative to conventional connectors. The aim was to systematically evaluate the technical performance, reliability and economic suitability of available systems under realistic environmental and stress scenarios. The project results provide industry with a sound basis for selecting suitable contacting systems for highly reliable applications.
Efficient PCB contacting for mechatronics and drive technology
Project PCB Direct Contact (T-1753)
Project & objective of printed circuit board contacting
The increasing demands on reliability, miniaturisation and service life of electrical connections mean that classic connectors are increasingly reaching their limits, particularly in mechatronics and drive technology. PCB direct contacts, in which the printed circuit board itself serves as an active contact partner, represent an alternative connection technology for this purpose.
In the research project Direct Contact PCB (T-1753), commercially available PCB direct contact systems were systematically examined and evaluated. The focus was on technical performance, reliability under realistic operating conditions, and economic suitability for industrial applications with high requirements for current carrying capacity and environmental resistance.
The aim of the project was to
- identify and classify available PCB direct contact systems on the market,
- evaluate their reliability under practical mechanical, thermal and climatic stresses,
- present technical and economic parameters in a comparable manner, and
- provide users with a sound basis for decision-making when selecting suitable contact systems.
Market analysis and contact systems examined
As part of a technology-neutral market analysis, commercially available PCB direct contacting systems for robust wire-to-board and board-to-board applications were identified and categorised. Representative systems covering different contacting principles were selected from this analysis, including direct splice and crimp connections, edge contacting, and indirect and radial contacting systems.
PCB direct contacting systems:
- Category 1: Contacting via splice/ crimp connection between cable and printed circuit board (direct), e.g. Autosplice
- Category 2: Plug contact between contact surfaces on the printed circuit board and connector (edge contact) (direct), e.g. Stocko
- Category 3: Connection via additional components in the printed circuit board (indirect), e.g. Molex
- Category 4: Radial contacting via metallised hole in the printed circuit board (direct), e.g. Harting
Test setup, evaluation & user benefits
The tests were carried out on specially developed test circuit boards with defined layer structures, copper thicknesses and glass transition temperatures to ensure a high degree of comparability of the results. The test programme included electrical measurements (contact resistance, current carrying capacity), mechanical stress tests (vibration, shock), thermal and climatic tests, and analytical analyses to identify wear mechanisms and causes of failure.
A multidimensional methodology combining technical performance indicators with economic criteria was developed to evaluate the contacting systems. The results were incorporated into an application-oriented utility analysis, which enables objective rankings and maps different application scenarios through adjustable weightings.
Based on the project results, a practical user guide for PCB contacting was also created to help developers and decision-makers select suitable PCB direct contacting systems, secure design decisions at an early stage, and reduce development and validation costs.
The PCB Direct Contact project (T-1753) was carried out by Fraunhofer EMFT as part of the FVA Mechatronics working group and was successfully completed in May 2025. The research was funded by the Forschungsvereinigung Antriebstechnik e. V. (FVA) (German Research Association for Drive Technology).