Evaluation of Mechanical Stress on Electronic Assemblies during Thermoforming and Injection Molding for Conformable Electronics

Schirmer J, Reichenberger M, Wimmer A, Reichel H, Neermann S, Franke J (2021)

Publication Type: Conference contribution

Publication year: 2021

Publisher: Institute of Electrical and Electronics Engineers Inc.

Conference Proceedings Title: 2021 14th International Congress: Molded Interconnect Devices, MID 2021 - Proceedings

ISBN: 9781728175096

DOI: 10.1109/MID50463.2021.9361624

Abstract

The integration of SMT components is necessary to produce more complex assemblies within the framework of conformable electronics. During High-Pressure-Forming (HPF) and subsequent overmolding electronic components must withstand high amounts of stress. In this study 0402- as well as 0603-sized chip resistors were mounted on different common polymer substrates using conductive adhesive paste followed by electrical and mechanical evaluation. Prior to HPF electronic components were positioned in areas of different local deformation. After HPF the specimen were characterized by shear force testing and electrical resistance measurements. In a similar manner, electronic components were tested to assess the mechanical behavior during injection molding. To examine different melt induced stress scenarios, electronic components were arranged parallel as well as perpendicular to the flow direction of the melt at different positions. Additionally, three different injection speeds were evaluated to assess the influence on the electrical conductivity and functionality of the assemblies. It was found that meandering of conductors is necessary for higher deformations. El. components (without additional nonconductive adhesives) can be placed in areas of up to 15% deformation, smaller package sizes seem to be advantageous for HPF. Regarding overmoulding, it was found that larger components (larger bonding area) is beneficial. Also, placement near the injection point, as well as low injection speeds should be avoided. Overall, el. components should be protected (using globtops / underfills etc.) to withstand consecutive HPF and overmoulding.

Authors with CRIS profile

Simone Neermann Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik Jörg Franke Lehrstuhl für Fertigungsautomatisierung und Produktionssystematik

Involved external institutions

Hochschule für Angewandte Wissenschaften Hof DE Germany (DE) Technische Hochschule Nürnberg "Georg Simon Ohm" DE Germany (DE)

How to cite

APA:

Schirmer, J., Reichenberger, M., Wimmer, A., Reichel, H., Neermann, S., & Franke, J. (2021). Evaluation of Mechanical Stress on Electronic Assemblies during Thermoforming and Injection Molding for Conformable Electronics. In 2021 14th International Congress: Molded Interconnect Devices, MID 2021 - Proceedings. Institute of Electrical and Electronics Engineers Inc..

MLA:

Schirmer, Julian, et al. "Evaluation of Mechanical Stress on Electronic Assemblies during Thermoforming and Injection Molding for Conformable Electronics." Proceedings of the 14th International Congress Molded Interconnect Devices, MID 2021 Institute of Electrical and Electronics Engineers Inc., 2021.

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