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BY-NC-ND 4.0 license Open Access Published by De Gruyter September 22, 2018

Silicone-based Chip-in-Foil System

  • Lena Bleck EMAIL logo , Andreas Heid and Rene von Metzen


Aiming at devices for bioelectronic medicine, this paper proposes a die embedding process for the fabrication of flexible smart implants. By combining thinned bare dies with a polymeric encapsulation, completely flexible implants can be designed. The dies are encapsulated using a flip-chip process and a backfilling with silicone rubber. A completely even surface without detectable edge between the chip and the surrounding polymer substrate is achieved by gluing the chips face-down onto a polyimide-covered substrate. The backside is coated with silicone rubber and a second carrier substrate is attached. Removing the first substrate subsequent to curing of the silicone leads to chips located under a continuous polyimide layer, enabling the use of microtechnology for further processing steps. A custom-made test chip is proposed that enables the evaluation of the mechanical and chemical stability of the system.

Published Online: 2018-09-22
Published in Print: 2018-09-01

© 2018 the author(s), published by Walter de Gruyter Berlin/Boston

This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

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