PACKAGE FOR FIELD DETECTOR

摘要

PROBLEM TO BE SOLVED: To provide a field detector in which the output does not depend on the air gap between an exciter and the detector. SOLUTION: A field sensor assembly 32 comprises a magnet 48, a semiconductor sensor 46 and a metal lead frame 44 enclosed in a plastic package 50 in order to form a semiconductor integrated circuit. The metal lead frame 44 comprises die fixing pads to be secured with a sensor, and an assembly having one or more protrusion for securing the magnet closely to the sensor 46. The sensor 46 is contiguous to a ferromagnetic body 38 and detects variation of field generated therefrom. Since only the thin film layer of the plastic package 50 covers the sensor, the distance between the sensor 46 and the ferromagnetic body 38 is decreased but an air gap sufficient for allowing passage of the ferromagnetic body 38 is kept between the plastic package and the ferromagnetic body.