Temperature coefficients of material properties for electrodeposited MEMS

Author

Chu, L.L. ; Long Que ; Gianchandani, Y.B.

Author_Institution

Dept. of Electr. & Comput. Eng., Wisconsin Univ., Madison, WI, USA

fYear

2001

fDate

25-25 Jan. 2001

Firstpage

68

Lastpage

71

Abstract

This paper presents the use of micromachined differential capacitive strain sensors to investigate mechanical properties of electroplated Ni deposited under two different conditions on Si and glass substrates. The thermal expansion coefficient (/spl alpha/), Young´s modulus, and residual strain were studied as a function of temperature. The measured a was 8-16 ppm/K over 23-150/spl deg/C; the residual strain changed from neutral to -880 microstrain over 23-100/spl deg/C in one case and +68.5 microstrain to -420 microstrain over 23-130/spl deg/C in another case; and the Young´s modulus ranged from 115-135 GPa at room temperature. The sensitivity of the device to structural non-idealities was evaluated by numerical modeling.

Keywords

Young´s modulus; capacitive sensors; electroplated coatings; micromechanical devices; microsensors; nickel; strain sensors; thermal expansion; 23 to 150 C; Ni; Si substrate; Young modulus; electrodeposited MEMS material; electroplated Ni; glass substrate; mechanical properties; micromachined differential capacitive strain sensor; microstrain; numerical model; residual strain; temperature coefficient; thermal expansion coefficient; Capacitive sensors; Glass; Material properties; Mechanical factors; Mechanical sensors; Strain measurement; Temperature distribution; Temperature measurement; Temperature sensors; Thermal expansion;

fLanguage

English

Publisher

ieee

Conference_Titel

Micro Electro Mechanical Systems, 2001. MEMS 2001. The 14th IEEE International Conference on

Conference_Location

Interlaken, Switzerland

ISSN

1084-6999

Print_ISBN

0-7803-5998-4

Type

conf

DOI

10.1109/MEMSYS.2001.906480

Filename

906480