Toggle Main Menu Toggle Search

Open Access padlockePrints

Voiding in Parylene-C Encapsulation of Surface Mount LEDs for an Optogenetic Epilepsy Neuroprosthesis

Lookup NU author(s): Dr Enrique Escobedo-Cousin, Dr Johan Gausden, Professor Anthony O'Neill


Full text for this publication is not currently held within this repository. Alternative links are provided below where available.


© 2023 IMAPS-International Microelectronics and Packaging Society. All rights reserved. It is often assumed that Parylene-C encapsulation films are void-free & conformal by nature of their vapour deposition. We present a case study in an optrode device where voiding occurs; we argue the voids originate from the geometry of the substrate and from the use of surface mount components. The segment under study consists of a commercial LED bonded with Au/Au thermosonic bonding onto a custom silicon substrate. We demonstrate via micro-sectioning that there is polymer voiding behaviour (1) in sub-LED surfaces; and (2) within through-hole vias in the silicon substrate (channels designed to allow polymer vapour ingress during deposition). By making a comparison to the solutions found in the IC industry around tungsten vapour filling of blind vias, we present geometric solutions for failure mitigation.

Publication metadata

Author(s): Idil AS, Bailey R, Escobedo-Cousin E, Gausden J, O'Neill A, Donaldson N

Publication type: Conference Proceedings (inc. Abstract)

Publication status: Published

Conference Name: 24th European Microelectronics & Packaging Conference (EMPC23)

Year of Conference: 2023

Pages: 340-344

Online publication date: 07/03/2024

Acceptance date: 02/04/2018

Publisher: International Microelectronics and Packaging Society (IMAPS)


DOI: 10.4071/001c.94831

Series Title: IMAPSource Proceedings