Please use this identifier to cite or link to this item:

Hydrophobic self assembly molecular layer for reliable cu-epoxy interface

Authors Wong, C.K.Y. HKUST affiliated (currently or previously)
Yuen, M.M.F. View this author's profile
Issue Date 2009
Source Proceedings - Electronic Components and Technology Conference , 2009, p. 1816-1823
Summary This paper discusses the use of a hydrophobic thiol based compound as adhesion promoter for copper (Cu)-epoxy interface. The motivation of this study is the long term reliability of the interface. In order to solve the moisture related reliability problem at the interface, thiol based molecules having hydrophobic characteristic (SAM N) is introduced at the interface. The rationale is to reduce the moisture uptake and hinder the diffusion into the interface. The thiol compound adsorbs onto a Cu substrate to form a self assembly molecular layer (SAM) through solution deposition. The SAM structure was designed to form covalent bonds with epoxy system while hydrophobicity was realized with long alkyl chains. The hydrophobicity of the surface treatment and wettability to epoxy adhesive was characterized using contact angle measurements with DI water and liquid epoxy. The wetting properties were shown independent of the treatment time. The results demonstrate selective wetting properties of the treatment. Water does not wet the treated surfaces (>110o) but the surfaces achieve good wetting with epoxy (<10o). Interfacial adhesion of the specimens prepared from modified substrates was bonded to epoxy and evaluated through a TDCB fracture test. In the reliability test, the GIC of the interface drops slightly from 45.7±5.5Jm-2 with freshly prepared specimens to 40.0±11.1Jm-2 with the moisture preconditioned ones. This indicates that with the SAM N treatment, the interfacial integrity is retained in long term service. The paper also discusses the hydrophobic behavior of the SAM N surface which enables long time storage of the pre-treated substrate under ambient environment. The paper introduces a new thiol based coupling agent which provides reliable Cu-epoxy interfaces. © 2009 IEEE.
ISSN 0569-5503
ISBN 978-1-4244-4475-5
Rights © 2009 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.
Language English
Format Conference paper
Access View full-text via DOI
View full-text via Scopus
View full-text via Web of Science
Files in this item:
File Description Size Format
05074265.pdf 1532416 B Adobe PDF