Denso Corporation

Yuichiro Murata

Yasutoshi Suzuki

Inao Toyoda

Hirofumi Uenoyama

Toshihisa Suzuki

Osamu Mochizuki

Kiyoshi Natsume

A motor control unit includes a sensing unit and a driver unit. The sensing unit includes a sensor magnet to rotate in synchronization with a rotation of a rotor included in a motor, and a first sensor element and a second sensor element to convert a signal caused by a rotation of the sensor magnet into a digital signal. The driver unit controls the motor based on output signals of the elements. The sensor magnet includes a first magnetization belt and a second magnetization belt where a plurality of magnetic poles is arranged in a peripheral direction of the rotor. The belts are concentrically disposed to cause arrangements of the magnetic poles to be shifted by a predetermined angle in a peripheral direction. The elements are arranged in a radial direction of the rotor.

Motor control unit

A magnetic sensor for detecting an object includes: a detection portion including one half bridge, which has two spin valve type electro-magnetic transformation devices disposed on a substrate; and a magnet near the detection portion having a magnetic field changeable in accordance with influence of the object. The spin valve type electro-magnetic transformation devices are arranged with respect to the magnet in such a manner that a direction of a magnetic field to be applied to one of the spin valve type electro-magnetic transformation devices is opposite to a direction of a magnetic field to be applied to the other one of the spin valve type electro-magnetic transformation devices.

Magnetic sensor having spin valve type electro-magnetic transformation device

Magnetoresistive devices are formed on the insulating surface of a substrate made of silicon. The devices are connected in series through an insulating film using a wiring layer formed on the surface of the substrate. An insulating film for passivation is formed to cover the devices and the wiring layer. A magnetic shield layer of Ni&#x2014;Fe alloy is formed on the passivation insulating film through an organic film for relieving thermal stress to cover one of the devices. After removal of the sensor chip containing the magnetoresistive devices and other components from the wafer, the chip is bonded to a lead frame through an Ag paste layer by heat treatment. Preferably, the magnetic shield layer is made of a Ni&#x2014;Fe alloy having a Ni content of 69% or less.

Method for manufacturing magnetic sensor

Magnetoresistive devices are formed on the insulating surface of a substrate made of silicon. The devices are connected in series through an insulating film using a wiring layer formed on the surface of the substrate. An insulating film for passivation is formed to cover the devices and the wiring layer. A magnetic shield layer of Ni&mdash;Fe alloy is formed on the passivation insulating film through an organic film for relieving thermal stress to cover one of the devices. After removal of the sensor chip containing the magnetoresistive devices and other components from the wafer, the chip is bonded to a lead frame through an Ag paste layer by heat treatment. Preferably, the magnetic shield layer is made of a Ni&mdash;Fe alloy having a Ni content of 69% or less.

Magnetic sensor and manufacturing method therefor

In a revolution detecting device, a tunneling magnetoresistance sensor having an element located in a region is provided. The tunneling magnetoresistance sensor comprises a substrate, a pinned layer composed of ferromagnetism material and located to one side of the substrate, a tunneling layer composed of insulating film and located to one side of the pinned layer and a free layer composed of ferromagnetism film and located to one side of the tunneling layer. The element is configured to detect a change of magnetoresistance of the element according to a magnetic field applied in the region in which the element is located. The change of the magnetoresistance of the element is based on a change of current flowing through the tunneling layer between the pinned layer and the free layer. In the revolution detecting device, a revolution member is disposed in a vicinity of the element in the Y axis from a viewpoint of the element. The revolution member has a surface portion opposite to the element. The surface portion is formed with S poles and N poles which are alternately arranged. In the revolution detecting device, a magnet is disposed in a vicinity of the element and generating the magnetic field and a direction of the magnetic field is substantially parallel to the Y axis at a center portion of the element. When the revolution member revolves, the S poles and N poles are configured to move substantially in parallel to the X axis on the Y axis determined by the element.

Growing community of inventors

Nagoya, Japan

Yuichiro Murata