Hermetic chip-scale packaging using Au:Sn eutectic bonding for implantable devices
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Author(s)
Szostak, Katarzyna Maria
Keshavarz, Meysam
Constandinou, Timothy
Type
Journal Article
Abstract
Advancements in miniaturisation and new capabilities of implantable devices impose a need for the development of compact, hermetic, and CMOS-compatible micro packaging methods. Gold-tin-based eutectic bonding presents the potential for achieving low-footprint seals with low permeability to moisture at process temperatures below 350 compfnC. This work describes a method for the deposition of Au:Sn eutectic alloy frames by sequential electroplating from commercially available solutions. Frames were bonded on the chip-level in the process of eutectic bonding. Bond quality was characterised through shear force measurements, scanning electron microscopy, visual inspection, and immersion tests. Characterisation of seals geometry, solder thickness, and bonding process parameters was evaluated, along with toxicity assessment of bonding layers to the human fibroblast cells. With a successful bond yield of over 70% and no cytotoxic effect, Au:Sn eutectic bonding appears as a suitable method for the protection of integrated circuitry in implantable applications.
Date Issued
2021-07-26
Date Acceptance
2021-07-08
Citation
Journal of Micromechanics and Microengineering, 2021, 31, pp.1-13
ISSN
0960-1317
Publisher
IOP Publishing
Start Page
1
End Page
13
Journal / Book Title
Journal of Micromechanics and Microengineering
Volume
31
Copyright Statement
© 2021 The Author(s). Published by IOP Publishing Ltd. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 license. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
License URL
Sponsor
Engineering & Physical Science Research Council (EPSRC)
Identifier
https://iopscience.iop.org/article/10.1088/1361-6439/ac12a1
Grant Number
EP/M020975/1
Subjects
cond-mat.mtrl-sci
cond-mat.mtrl-sci
physics.med-ph
Nanoscience & Nanotechnology
09 Engineering
10 Technology
Publication Status
Published
Date Publish Online
2021-07-26