A
highly sensitive silicon micro-machined sensor
package is provided for use in a micro-g environment that can also
resist high shock in excess of 5000 g. The sensor is provided to measure acceleration in cooperation with associated
electronics which are required to have electrical contact with sensor elements. The sensor is sealed in a high vacuum environment, and is arranged and designed to be free of
temperature induced stress to the sensor. The sensor die
package assembly comprises a
silicon micro-machined sensor die, a
ceramic package, two contact springs, a shorting clip, solder preform, a
metal lid and a
getter foil for ensuring a good vacuum for an extended period. The sensor die comprises a moving
mass with eight supporting flexures on both sides of the
proof mass. The
proof mass's movement is protected on both sides by a top and a bottom cap. Acceleration applied to the package and the die causes the
proof mass to move vertically in relation with the adjacent caps. The changes in distance between the proof
mass and the caps in turn generate a change in an electrical
signal which corresponds to the
capacitance changes between the gaps. The sensor die package arrangement provides that the sensor die be secured within an evacuated
ceramic case. Electrical connections made between external contacts of the case and contacts of the sensor die within the case are made through conductive springs, thereby minimizing materials in the interior of the case which would outgass in the vacuum environment.