Volume 93, Issue 8 p. 2274-2280

Microwave Sintering of Multilayer Integrated Passive Devices

Balasubramaniam Vaidhyanathan

Corresponding Author

Balasubramaniam Vaidhyanathan

Department of Materials, Loughborough University, Leicestershire LE11 3TU, U.K.

*Member, The American Ceramic Society.

Author to whom correspondence should be addressed. e-mail: [email protected]Search for more papers by this author
Ketharam Annapoorani

Ketharam Annapoorani

Department of Materials, Loughborough University, Leicestershire LE11 3TU, U.K.

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Jon Binner

Jon Binner

Department of Materials, Loughborough University, Leicestershire LE11 3TU, U.K.

*Member, The American Ceramic Society.

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Ramesh Raghavendra

Ramesh Raghavendra

Littelfuse Ireland Limited, Ecco Road, Dundalk, Republic of Ireland

Present address: South Eastern Applied Materials Research Center (SEAM), Waterford Institute of Technology, Waterford, Ireland.

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First published: 17 August 2010
Citations: 11

L. Levinson—contributing editor

Part of the results were presented at the 33rd ICACC meeting in January 2009, Daytona Beach, FL, USA, organized by the American Ceramics Society.

This work was financially supported by Littelfuse Ireland Limited.

§Varistor is a voltage-dependent resistor whose primary function is to sense and limit voltage surges and hence protect sensitive circuit components.

Abstract

Microwave sintering of multilayer capacitor/varistor-based integrated passive devices (IPDs) has been investigated for the first time. The sintered samples were characterized for density, microstructure, composition, and electrical performance. It was found that IPDs with varistor/capacitor formulations could be microwave sintered to fully dense device components within 3 h of total cycle time, which is <1/10th of the time required by conventional methods. Microwave sintering resulted in products with a finer grain structure and without delamination or significant interdiffusion between the ceramic/electrode and varistor/capacitor interfaces. The microwave method also completely eliminated the need for a separate binder burnt-out step. The electrical properties of the microwave-sintered samples were found to better or match those obtained by conventional, industrial processing. In general, the simplicity, rapidity, and superior product performance make the microwave technique an attractive sintering methodology for the processing of IPDs.