Online proceedings - EDA Publishing Association

11-13 May, Aix-en-Provence, France
Standards for Hermeticity Test Methods
Suzanne Costello
MIcroSystems Engineering Centre, School of Engineering and Physical Sciences,
Heriot-Watt University, Edinburgh, EH14 4AS, Scotland, UK.
E: S.Costello@hw.ac.uk T: +44 (0) 131 451 3774
ABSTRACT:
Traditional hermeticity test methods and the standards used to ensure correct usage of these test methods have been
shown to have limitations when applied to low cavity volume MEMS packages. Typical MEMS cavity volumes are
well below the minimum volumes stated in the military standards leading to inaccuracies when the traditional
hermeticity tests are carried out on such packages. Ultra low vacuum packaging is required for many MEMS
applications, reducing the maximum acceptable leak rate of these packages below the measurable range of most test
methods given in the military standards. New packaging materials used in MEMS manufacturing have limited the use
of standard tests since new leak sources are apparent which the traditional test methods were not designed to measure
and so are not considered in the military standards.
SEMI MS8-0309 - GUIDE TO EVALUATING HERMETICITY OF MEMS PACKAGES was written to inform and
guide users on the best way to quantify leaks which may adversely affect the performance of MEMS devices. Two
further test standards are currently being written to provide further information and guidelines to quantifying
permeation leaks and outgassing. The first of these standards, “SEMI Standards: Fluid Permeation through MEMS
Packaging Materials”, will be discussed.
BIOGRAPHY:
Suzanne Costello graduated from Heriot-Watt University in Edinburgh in 2004 after receiving a masters degree in
physics. She is currently working towards an engineering doctorate in microsystems engineering. Her sponsoring
company is materials and failure analysis specialists, MCS Limited. Her research has been based on hermeticity
testing of MEMS and low cavity volume microelectronic packages. She has published several papers in this field
which have shown the theoretical limitations of the traditional hermeticity test methods when applied to today’s
packages and the advantages of in situ test structures for assessing leak rates of low volume packages. Suzanne has
also been involved in the task force working towards creating a new standard to assess fluid permeation through
MEMS packaging materials.
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