JP2001326484A - Printed board with heat radiation pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat radiating means for a motor which is applicable to a heat-nonconductive material such as plastic fixing the motor even if a heat sink is characterized in that materials which control a driving voltage for suppressing the heat radiation of the motor and fixing the motor are metal having a high heat emissivity. SOLUTION: A flexible printed board 10 is composed of a heat radiation pattern part 11 and a wiring pattern part 12 for driving the motor; and the heat radiation pattern part 11 is copper foil used to wire an ordinary flexible printed board and wide enough to cover the heat radiation part width of the motor and the wiring pattern part 12 for motor driving is patterned to an ordinary width. One flexible printed board 10 having the wiring pattern part, 12 has a land 12a in pattern enabling the matching soldering between the electrodes of the motor and lead wires and the other has a land 12b in pattern enabling the matching pattern between the circuit board driving the motor and the lead wires.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printed circuit board used for wiring a motor, and more particularly to a printed circuit board capable of easily releasing heat from a motor without increasing the number of heat radiating plates for the motor.

[0002]

2. Description of the Related Art There are motors such as a brushless DC motor, a molded motor, and a stepping motor. The brushless DC motor is entirely molded by premixing, and uses an IC element that generates a large amount of heat, such as a power IC, a power transistor, and a motor drive IC. These IC elements have a small surface area and locally increase in temperature. Due to this temperature rise, the performance of this element may be degraded or destroyed. Therefore, a large output UP cannot be performed, which restricts the motor output characteristics, and it is difficult to design a high-output motor with a built-in IC circuit. Was. In addition, by controlling the number of revolutions of the brushless DC motor, current flows to motor control circuit elements including IC elements such as a motor drive IC, and these elements generate heat. For that purpose, make a hole in the IC element mounting part of the PC board,
In addition, by changing the shape of the heat sink to a substantially U-shape so that the heat sink can be sandwiched from both the front and rear surfaces of the IC element, the effect of dissipating heat generated from the IC element is enhanced. .

In a molded motor, a resin mold portion is formed around a stator core formed by winding windings, and a bearing for supporting a rotating shaft of a rotor is provided on at least one side of the stator. And an end bracket having a flange portion connected to the end portion and having a ventilation hole. In this case, external air is sucked from the ventilation hole,
Since the heat trapped inside the motor is released to the outside but not sufficiently, the temperature of the bearing rises greatly, affecting the service life and causing a problem of reducing reliability. Therefore, a temperature rise is prevented by providing a plurality of ventilation passages from the inner peripheral surface of the resin mold portion to the outside of the flange portion.

[0004] The heat discharged from the ventilation passage increases the internal temperature of the device in which the motor is incorporated by controlling the drive voltage of the motor body and using a metal having a high heat dissipation property for fixing the motor. Is preventing.

[0005]

For example, in a motor for driving an autofocus photographing lens having a motor in precision equipment such as an interchangeable lens for a camera, heat generated by the motor is not generated when the motor is driven for a long time. Even if a metal heat sink with high heat dissipation is used to control the drive voltage and fix the motor to hold down the motor, the space for the motor is limited, so the heat generation of the motor itself and the mirror Temperature rise inside the cylinder was inevitable. As for the material for fixing the motor, the volume of the heat radiating plate is increased, and even if a material with high heat radiating properties is used, a large amount of metal is used. As a result, the weight of the interchangeable lens increases, resulting in an increase in size and cost. There was also a problem that goes up.

When the material for fixing the motor inside the lens barrel is non-thermally conductive such as plastic, the heat radiation portion of the motor cannot be brought into direct contact with a heat dissipating metal portion or the like.

[0007]

According to the present invention, attention is paid to the fact that a printed circuit board for controlling the motor is used for the device in which the motor is incorporated, and the printed circuit board is used for heat radiation. That is, a wiring pattern portion for driving the motor and a heat radiation pattern portion for dissipating heat of the motor are provided on a printed circuit board used for wiring of the motor, and the heat radiation pattern portion is attached so as to contact the heat radiation portion of the motor body. The heat generated by the motor is suppressed by radiating heat by fixing a part of the tip to a metal part of a device in which the motor is incorporated.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described with reference to the drawings.

FIG. 1 is a longitudinal sectional view of a motor body according to an embodiment of the present invention, FIG. 2 is a plan view showing an outer diameter and a pattern of a printed circuit board, and FIG. 3 is a perspective view showing a state where the printed circuit board is mounted on a motor. It is. .

Referring to FIG. 1, a stator iron core 21 is provided with a winding 22 after its surface is insulated by pre-molding or the like.
A PC board 23 is provided on the stator core 21 and the PC
The plate 23 has a power IC for performing a switching action.
And a motor drive IC for performing a control action. Some of these two IC elements are packaged in one module. The PC plate 23 and the stator core 21 wound with the windings 22 are integrally molded with a premix 24 to form a stator 25.
A permanent magnet 27 is fixed to the outer periphery of the rotor 26 by bonding or the like. The stator 25, the rotor 26, the bracket 28 and the bearings 29a,
9b and the like constitute the motor body 20 of the brushless DC motor.

By controlling the number of revolutions of the motor body 20 of the brushless DC motor, a current flows through a motor control circuit element including an IC element 30 such as a motor drive IC, and these elements generate heat. Heat sink 31 as a measure against heat generation
Is mounted on the upper part of the IC element 30.

FIG. 2 is a plan view showing the outer diameter and pattern of the printed circuit board. Reference numeral 10 denotes a flexible printed circuit board to which the present invention is applied. Flexible printed circuit board 10
Is composed of a heat radiation pattern portion 11 and a motor driving wiring pattern portion 12 for driving a motor. The heat radiation pattern portion 11 is made of copper foil used for wiring of a normal flexible printed circuit board, and is configured to be wide so as to cover the width of the heat radiation portion of the motor. The wiring pattern portion 12 for driving the motor has a pattern with a normal width.

One side of the flexible printed circuit board 10 having the wiring pattern 12 has a land 12a of a pattern that can be soldered to the electrode of the motor and the lead wire. The other side is a land 12b of a pattern that can be soldered by aligning the lead with the circuit board that drives the motor.
have.

The patterns other than the joint soldering are insulated on the front and back surfaces of the flexible printed circuit board 10 so that they are safe even when they come into contact with the metal part of the motor or the metal part of the lens barrel.

The heat radiation pattern portion 11 is separate from the wiring pattern portion 12 for driving the motor,
Exists on top. The heat radiation pattern 11 is in contact with the motor body and the metal part of the lens barrel to increase the heat radiation efficiency, so that the heat radiation pattern 11 of a copper foil pattern is exposed on the back surface of the flexible printed circuit board 10.

FIG. 3 is a perspective view showing a state where a printed circuit board is attached to the motor. As shown in the figure, the metal part of the motor body 20 covers the exposed heat radiation pattern part 11 so as to make a circuit while making contact therewith, and the remaining heat radiation pattern part contacts the metal part of the lens barrel (not shown). Body 20
Dissipates heat from

Although the embodiment has been described using a flexible printed circuit board as a printed circuit board, the present invention can be applied to a hard printed circuit board as long as the heat radiating portion of the motor is formed of a flat surface.

[0018]

The heat radiation from the motor itself is provided by providing a heat radiation pattern separately from the motor driving pattern on a printed circuit board for controlling the motor of a device in which the motor is incorporated, so that the metal of the motor body and the lens barrel can be removed. The parts are connected to each other by a copper foil pattern to perform heat dissipation, so that the heat dissipation effect is promoted. Further, since a separate heat sink is not required, there is an effect of weight reduction. Further, if the present invention is applied, it is not necessary to process the motor body, so that heat can be radiated from all types of motors.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view of a motor to which the present invention is applied.

FIG. 2 is a plan view showing an outer diameter and a pattern of a printed circuit board.

FIG. 3 is a perspective view showing a state in which a printed circuit board is attached to a motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Flexible printed board 11 Heat dissipation pattern part 12 Wiring pattern part 12a, b Land 20 Motor main body 21 Stator iron core 22 Winding 23 PC board 24 Premix 25 Stator 26 Rotor 27 Permanent magnet 28 Bracket 29a, b Bearing 30 IC Element 31 heat sink

Claims (1)

[Claims] 1. A motor drive wiring pattern portion and a heat dissipation pattern portion for dissipating heat of the motor are provided on a printed circuit board used for wiring of the motor, and are attached so as to contact the heat dissipation portion of the motor body. A printed circuit board having a heat radiation pattern, wherein the heat radiation is performed by the heat radiation.