A piezoresistive sensor chip for measurement of stress in electronic packaging

This paper presents the first experimental results of calibration of the 22.5/spl deg/ "off-axis" rosette. This rosette requires the application of only uniaxial stress for measurement of the three individual piezoresistive coefficients of silicon: /spl pi//sub 11/, /spl pi//sub 12/ and /spl pi//sub 44/. Of even greater potential import. This rosette yields inherently temperature compensated values of the coefficients /spl pi//sub 44/ and /spl pi//sub D/=(/spl pi//sub 11/-/spl pi//sub 12/) P-type off-axis rosettes have been characterized as a function of temperature and values for the temperature dependencies of /spl pi//sub 44/ and /spl pi//sub D/ are reported. The coefficients /spl pi//sub 44/ in p-type silicon and /spl pi//sub D/ in n-type silicon are needed for an optimized stress sensor on (100) silicon.<
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