In a steering angle sensor assembly for a vehicle, dependent gears are provided to mesh with an inner periphery of a rotary member rotated together with a steering wheel and to be rotated, and a circuit board that detects the rotation of the dependent gears and generates electric signals is also provided on the side of the dependent gears provided on the inner periphery of the rotary member. Suture packages are located in an interior space of the housing and biased towards a top of the device. In many implementations, physical layout of the IC does not include the step of routing.