Inertial force sensor

Abstract

An inertial force sensor that can suppress fluctuation of detection sensitivity even if an external stress is applied to the inertial force sensor. Angular velocity sensor ( 1 ), that is, an inertial force sensor includes ceramic substrate ( 6 ), lower lid ( 4 ) adhering to ceramic substrate ( 6 ) with adhesives ( 11 a and 11 b ) (first adhesives), and sensor element ( 2 ) adhering to lower lid ( 4 ) with adhesives ( 10 a and 10 b ) (second adhesives). The elastic moduli of adhesives ( 11 a and 11 b ) are smaller than those of adhesives ( 10 a and 10 b ).

1 . An angular velocity sensor comprising:
 a substrate;   a circuit chip having first chip electrodes at a first side of the circuit chip and second chip electrodes at a second side of the circuit chip, the first side of the circuit chip being opposite to the second side of the circuit chip; and   a sensor element having
 first sensor electrodes at a first side of the sensor element, the first sensor electrodes being electrically connected to the first chip electrodes at the first side of the circuit chip, and 
 second sensor electrodes at a second side of the sensor element, the second sensor electrodes being electrically connected to the second chip electrodes at the second side of the circuit chip, 
   
       wherein
 the first side of the sensor element being opposite to the second side of the sensor element, 
 
       wherein
 the sensor element having a center beam part being parallel to the first side of the sensor element and the second side of the sensor element, the sensor element having at least four beam parts connected to the center beam part, 
 
       wherein
 the circuit chip has third chip electrodes, being electrically connected to first substrate electrodes on the substrate, at a third side of the circuit chip, and 
 
       wherein
 the third chip electrodes at the third side of the circuit chip are aligned perpendicular to the first side of the circuit chip and the second side of the circuit chip. 
 
     
     
         2 . The angular velocity sensor according to  claim 1 , wherein
 the circuit chip has fourth chip electrodes, being electrically connected to second substrate electrodes on the substrate, at a fourth side of the circuit chip, and   the fourth chip electrodes at the fourth side of the circuit chip are aligned perpendicular to the first side of the circuit chip and the second side of the circuit chip.   
     
     
         3 . The angular velocity sensor according to  claim 1 , wherein
 the first sensor electrodes at the first side of the sensor element are electrically connected to the first chip electrodes at the first side of the circuit chip via metal bumps, and   the second sensor electrodes at the second side of the sensor element are electrically connected to the second chip electrodes at the second side of the circuit chip via further metal bumps.   
     
     
         4 . The angular velocity sensor according to  claim 1 , wherein
 the circuit chip has a rectangular shape in which a longer side is longer by 10-20% than a shorter side.   
     
     
         5 . The angular velocity sensor according to  claim 1 , wherein
 the third chip electrodes at the third side of the circuit chip are disposed outside of a region located between the first chip electrodes at the first side of the circuit chip and the second chip electrodes at the second side of the circuit chip.   
     
     
         6 . The angular velocity sensor according to  claim 2 , wherein
 the fourth chip electrodes at the fourth side of the circuit chip are disposed outside of a region located between the first chip electrodes at the first side of the circuit chip and the second chip electrodes at the second side of the circuit chip.