Seminar Highlights Technical Challenges for Humidity Robustness and Insulation Performance in Automotive Electronics

Recap of the iNEMI / ZESTRON seminar held February 1, 2024, in Ingolstadt, Germany. 

Follow-up webinar is scheduled March 27, 2024

The Seminar on Humidity Robustness and Insulation Coordination for e-Mobility, organized by iNEM and ZESTRON Europe, and supported by the ECPE, provided an excellent summary of the technical challenges in the areas of humidity robustness and insulation performance to a full house of attendees. The presentations and discussions highlighted the cohesive requirements in understanding the challenges of high-voltage electronics in automotive electronics, from materials characterization and selection to understanding application requirements and environmental stressors. A key takeaway from the seminar was that e-mobility has new challenges and there are key gaps in the present standards and test methods.

Hendrick Meinhardt of BMW opened with a presentation on the technical cleanliness requirements for automotive. Defective technical cleanliness (TecSa) in battery electric vehicles can lead to poor performance and safety risks. He gave an overview of specification for technical cleanliness testing and discussed the TESCa assessments used by BMW.  A summary of the TESCA standards commonly used was given and the outlook on the status for updating them to support e-mobility was also discussed.

The basics and mechanisms of insulation were discussed by Viven Grau of Bosch's Advanced Technologies and Micro Systems. The types of insulation materials, their advantages and disadvantages and breakdown mechanisms were presented. The influences on the dielectric strength such as thermal effects, electrical stress, ambient condition and mechanical stresses were also highlighted.

The humidity robustness of insulation materials under high voltage was discussed by Sven Clausner of the University of Bremen. The High Voltage-High Humidity High Temperature Reverse Bias (HV-H³TRB) test is used to investigate humidity-driven issues in packaged devices and electronic assemblies. He discussed some of the challenging environments for electronics and the relevant tests that are presently being used at both chip and board level.

Stefan Schroeder and Johannes Tekath of Peters talked about the need for conformal coating, particularly in the challenging and harsh environments of automotive electronics. They discussed in particular the challenges of high-voltage applications, the different test methods and structures used, as well as the common failure modes experienced. 

The perspective of the component supplier on the challenges of high voltage and harsh environment was presented by Ove Hach of Vishay. Selection of such components depends on understanding  the performance potential through the resistor figure of merits and an understanding of the requirements of the application space.

Andreas Koch from Indium gave a presentation focused on the reliability expectations for automotive electronics assemblies.  In particular, he highlighted the potential benefits of no-clean fluxes and discussed the test methodologies presently being used plus the need to standardize test methods for automotive applications of the future.

Helmut Sweigert of ZESTRON closed the seminar discussing high-voltage failure mechanisms and highlighting the gap in standards (e.g., IEC 60664). He presented an analytical approach to close the gap and called for more characterization of materials for high-voltage applications. 

A follow-up webinar on March 27 will focus on the gaps and challenges identified at the seminar and discuss potential collaborative iNEMI projects to address them. Get additional details.