Load drive device

Patent metadata

Field	Value
Publication number	US-10604173-B2
Application number	US-201816171880-A
Country	US
Kind code	B2
Filing date	Oct 26, 2018
Priority date	Oct 27, 2017
Publication date	Mar 31, 2020
Grant date	Mar 31, 2020

Abstract

A board of a controller of a load drive device includes: wiring layers provided on front and rear surfaces and inside thereof and ground layers provided inside thereof. Each wiring layer is divided into: a first region in which a drive circuit is provided; and a second region in which a control circuit is provided. A first ground layer including a first ground pattern for a circuit which is electrically connected to a wiring pattern of each wiring layer is divided into: a third region which overlaps with the first region in a thickness direction, and in which the first ground pattern for a power system electrically connected to the drive circuit is provided, and a fourth region which overlaps with the second region in the thickness direction, and in which the first ground pattern for a control system electrically connected to the control circuit is provided.

First claim

The invention claimed is:

1. A load drive device comprising:
an electric motor that drives a load;
a controller that comprises a board provided with electronic components mounted thereon and configured to drive and control the electric motor;
a housing in which the electric motor is incorporated;
a frame that is connected to the housing and serves as a heat sink; and
a cover that is attached to the frame so as to cover the board,
wherein the board is fixed to the frame so as to be electrically connected to a motor terminal configured to supply a current to the electric motor and perpendicular to an axial direction of a rotation axis of the electric motor,
wherein the board is one multilayer printed board comprising: wiring layers comprising wiring patterns and provided on a front surface and a rear surface of the multilayer printed board, respectively; at least one wiring layer comprising a wiring pattern and provided inside the multilayer printed board; and at least two ground layers comprising ground patterns, respectively, and provided inside the multilayer printed board, and the board comprises an interlayer connection wire that electrically connects the patterns of the different layers,
wherein the wiring pattern of each of the wiring layers configures a part of an electric circuit of the controller,
wherein the electronic components included in the electric circuit are mounted on the front surface and the rear surface of the board, respectively,
wherein the at least two ground layers comprise: a first ground layer comprising a first ground pattern for a circuit which is electrically connected to the wiring pattern of each of the wiring layers; and a second ground layer comprising a second ground pattern for electromagnetic wave noise resistance which is electrically connected to the frame,
wherein the electric circuit of the controller comprises: a drive circuit that drives the electric motor; and a control circuit that controls the electric motor,
wherein each of the wiring layers is divided into:
a first region in which the drive circuit is provided, and
a second region in which the control circuit is provided, and

wherein the first ground layer is divided into:
a third region which overlaps with the first region in a thickness direction of the board, and in which the first ground pattern for a power system electrically connected to the drive circuit is provided, and
a fourth region which overlaps with the second region in the thickness direction of the board, and in which the first ground pattern for a control system electrically connected to the control circuit is provided.

2. The load drive device according to claim 1 ,
wherein a rotation sensor configured to detect a rotation state of the electric motor is mounted on the rear surface of the board, and
wherein in the board, the first region and the third region are disposed on one side which does not include the rotation sensor with respect to a mounting position of the rotation sensor, and the second region and the fourth region are disposed on the other side which includes the rotation sensor with respect to the mounting position of the rotation sensor.

3. The load drive device according to claim 1 ,
wherein the motor terminal penetrates a portion of the frame overlapping with the electric motor in the axial direction, the motor terminal is electrically connected to a portion of the board overlapping with the electric motor in the axial direction, and the motor terminal is electrically insulated from the frame,
wherein the motor terminal comprises a connector mounted on a portion of the board which does not overlap with the electric motor in the axial direction,
wherein the connector comprises: a first fitting portion to which a first harness configured to supply the current from an external power source is fitted in an axial direction of the electric motor; and a second fitting portion to which a second harness configured to perform signal communication with an external device is fitted in the axial direction of the electric motor, and
wherein the first fitting portion and the second fitting portion are exposed to an electric motor side from the frame.

4. The load drive device according to claim 3 ,
wherein the third region and the fourth region of the first ground layer merge with each other in the vicinity of the connector.

5. The load drive device according to claim 3 ,
wherein a plurality of semiconductor switching elements configured to switch the current to be supplied to the electric motor are mounted on a portion of the first region overlapping with the electric motor in the axial direction, and
wherein an electrolytic capacitor electrically connected to the plurality of semiconductor switching elements is mounted in the vicinity of one of the semiconductor switching elements which is located at a position farthest away from the connector and which is connected to an upstream side of the current to be supplied from the external power source.

6. The load drive device according to claim 1 ,
wherein a heat-generating electronic component is mounted on a portion of the front surface of the board which overlaps with the electric motor in the axial direction,
wherein a heat transfer portion that transfers heat generated by the heat-generating electronic component to the rear surface of the board is disposed immediately below the heat-generating electronic component in the board, and
wherein an insulating heat radiation material is disposed between a portion of the rear surface of the board which overlaps with the electric motor in the axial direction and a portion of the frame.

7. The load drive device according to claim 1 ,
wherein the board has a plurality of through-holes and a conductive portion electrically connected to the second ground pattern of the second ground layer around the through-holes,
wherein the frame has a plurality of screw holes disposed coaxially with the through-holes, respectively,
wherein the load drive device further comprises a plurality of screws made of a conductor, and
wherein the screws are inserted into the respective through-holes from the front surface of the board and are screwed into the respective screw holes such that the board is fixed to the frame, and the screws come into contact with the conductive portion and electrically connect the second ground pattern and the frame.

Assignees

• Okamura Akio
• Togawa Shinichi
• Omron Automotive Electronics

Inventors

• Okamura Akio
• Togawa Shinichi

Classifications

• H05K2201/10151

  Sensor · CPC title

• H05K2201/09663

  Divided layout, i.e. conductors divided in two or more parts · CPC title

• H05K5/0069

  having connector relating features for connecting the connector pins with the PCB or for mounting the connector body with the housing · CPC title

• H05K1/0215

  Grounding of printed circuits by connection to external grounding means · CPC title

• B62D5/0406 Primary

  including housing for electronic control unit · CPC title