MANUFACTURING METHOD OF PRESSURE SENSOR

摘要

PROBLEM TO BE SOLVED: To reduce the effects of temperature characteristics of offset voltage in a bridge circuit in an absolute pressure sensor. SOLUTION: The offset voltage (gauge offset initial value;VoffINIT) of a bridge circuit in a plurality of pressure sensors on a silicon wafer is measured in room temperature and high temperature to obtain the difference value (gauge offset difference value). Then, correlation of the gauge offset difference value to the gauge offset initial value is determined and a correlation linear line approximating the distribution is obtained. The values of A and B where both of the gradient and the Y-intercept of the correlation line become 0 are obtained from the correlation. An aim value of the output voltage of the bridge circuit is calculated based on the gouge offset initial value VoffINIT of the bridge circuit and the constants A and B. Then the parallel resisters R72 and R82 are trimmed so as to be the calculated aim value. The series resistors R7 and R8 are trimmed so that the offset voltage of the bridge circuit becomes 0. COPYRIGHT: (C)2006,JPO&NCIPI