MAGNETIC FIELD SENSOR AND METHOD FOR MANUFACTURING MAGNETIC FIELD SENSOR

摘要

PROBLEM TO BE SOLVED: To provide a packaging system for a magnetic field sensor that allows a magnetic field sensing element to be brought to a magnet as close as possible by avoiding an excessive increase of an effective air gap between a magnetic field sensing element relevant to an environment and an object to be sensed.SOLUTION: The present method includes a step of mounting a magnetic field sensor circuit die 10 on a first surface of a pad with die of a lead frame 12b. The pad with die has a first surface and a second opposite surface, and includes a cavity 16c having an inner cavity surface neighboring to the second surface. The method further includes a step of forming a molded capsule 16 including the magnetic field sensor circuit die. The cavity has a shape capable of holding a liquid, and includes a step of providing a liquid material 20 in the cavity adjacent to the second opposite surface and curing the liquid material. The liquid material is filled with ferromagnetic particles for the purpose of either forming or concentrating the magnetic field.