JP2002112516A - Brushless motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize mounting of a drive circuit on a printed wiring board 1 with a small area, by mounting a bare chip of a semiconductor component and sealing it with resin, and do away with a plastic package for the semicon ductor component. SOLUTION: The bare chip component 2 as a semiconductor component is used, and the bare chip component 2 and distributing wires 3 are sealed with a protective resin 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a brushless motor, and more particularly to a brushless motor used as a drive source for a blower fan of a room air conditioner or a water heater.

[0002]

2. Description of the Related Art Conventionally, a brushless motor is disclosed, for example, in Japanese Patent Application Laid-Open No. 6-90552.
Hereinafter, a specific description will be given with reference to the drawings. 9 is a sectional view showing a conventional brushless motor, FIG. 10 is a perspective view showing a stator core shown in FIG. 9, FIG. 11 is a perspective view showing a printed wiring board shown in FIG. 9, and FIG. It is a perspective view which shows a child. The stator 11 includes the insulator 11
8 and the winding 119 is wound. The main printed circuit board 125 made of an aluminum base is provided with an insertion hole 108 for positioning the rivet 128 for fixing the bracket 116 and a molding die.

[0003] On one surface of the main printed circuit board 125, a chip component 110 which is a surface mounting component such as a resistor which is a driving circuit component and a bare chip component 102 such as a power transistor and a driving IC are surface-mounted. And is covered with a protective resin 111. Winding 119 and main printed circuit board 1
25, the main printed circuit board 12
5, a plurality of connection substrates 126 of a glass substrate provided with through holes 126a are radially soldered.

The connection printed circuit board 126 has a through hole 126a at one end thereof, and is used for connection with the winding 119. Printed circuit board for connection 1
A land for connection to the main printed circuit board 125 is formed on the back surface of the other end 126b different from the end provided with the through hole 126a. The land and the through hole 126a are electrically connected by a copper foil 126c. On the main printed circuit board 125, a connector 107 for connection to a power supply line is mounted.

A position detecting element 109 serving as a position sensor of the rotor 114 is mounted on the innermost side of the main printed circuit board 125 in correspondence with the position detecting magnet 114a of the rotor 114. A magnet 127 is mounted on the rotor 114. The stator 112 is formed by integrally molding a main printed circuit board 125 on which a drive circuit component, a connection printed circuit board 126 and a connector 107 are surface-mounted together with a stator core 117 with a thermosetting synthetic resin.
The stator 112 includes a mold layer 112a,
Exposed portion 112 generated by fixing the printed circuit board with a mold
b.

In this conventional brushless motor, a bare chip component 2 as a power component, a printed circuit board 126 for connection, and a connector 107 are surface-mounted on one surface of a main printed circuit board 125, and heat is integrally formed together with a stator core 117. The mold layer 112a on the other surface of the main printed circuit board 125 molded with a curable synthetic resin is made thin. For this reason, the heat generated by the power components is
5, the heat can be dissipated through the thin mold layer 112a, so that the heat dissipating property can be improved and the brushless motor can be made thinner and smaller. In addition, the thin mold layer 112a
The exposed portion 11 from which the other surface of the main printed circuit board 25 is exposed
2b is formed. For this reason, since the main printed circuit board 125 is partially exposed to the outside air, the heat dissipation can be further enhanced.

Another conventional brushless motor is disclosed in, for example, JP-A-2000-14112. FIG. 13 is an exploded perspective view showing another conventional brushless motor, and FIG. 14 is a sectional view showing the brushless motor shown in FIG. 13 and 14, the same reference numerals as those in FIGS. 9 to 12 indicate the same or corresponding parts.
A stator winding 119 is directly wound around a stator core 117 having a plurality of slots via an insulator 118. The terminal of the winding of the stator winding 119 is the terminal pin 1
20 and soldered.

In the stator 112, the terminal pin 120, the stator core 117, and the stator winding 119 are integrally formed and solidified by resin molding. A rotor 114 having a permanent magnet 127 is provided in the center of the stator 112, and the bracket 116 holds the bearing 121 of the rotor 114. The printed circuit board 101 has a position detecting element 109 for detecting the position of the rotor 114, and the lead wire 123
It is connected to the printed circuit board 101. Bush 129
Has a groove for accommodating the lead wire 123 and is fixed to the outer peripheral notch of the stator 112.

In the above configuration, the printed circuit board 101
The insertion hole 108 is inserted into the terminal pin 120 of the stator 112, soldered to the terminal pin 120 again, and the connection between the windings is made on the printed circuit board 101 and fixed. The lead wire 123 is pinched by a bush 129, and the bush 129 is pinched by the stator 112 and the bracket 116. As described above, the brushless motor is completed.

[0010]

The drive circuit mounted on a brushless motor is accompanied by demands for downsizing, thinning, and high output of the motor accompanying the downsizing of the device, and cost reduction of the device. The demand for lowering the cost of the motor is very strong, and the conventional configuration as described above has been configured using a circuit board that is an expensive base material such as aluminum or a plurality of circuit boards such as aluminum or glass epoxy. Therefore, there has been a problem that the material cost and the processing cost are significantly increased.

Conventionally, when a driving element is mounted on a bare chip, a metal base substrate made of an aluminum base material having good heat radiation properties has to be used, which has been expensive. When a control IC or a driving element sealed in a plastic package is mounted on a circuit board, the control IC or the driving element has a large area, and there is a problem that the shape of the motor becomes large. In particular, an IC in which a control IC and a driving power element are packaged in one package,
Further, each of the plus-packaged control ICs, power semiconductor elements, and the like has a problem that the circuit board becomes large.

Conventionally, a position detecting element on a circuit board is arranged on an arc centered on a rotor axis. However, the arrangement of signal output leads of this element is largely taken into consideration with respect to the arrangement of elements. In addition, there are problems that not only the circuit board becomes unnecessarily large, but also the motor becomes larger and the cost of the motor increases.

Conventionally, when a printed circuit board is fixed with a resin molding die during resin molding of a stator and a circuit, exposed portions of the circuit are generated at this portion, and quality is reduced, such as a decrease in insulation due to the entry of humidity. There were problems such as problems arising.
In addition, expensive materials have been used for heat radiation of the driving elements mounted on the printed wiring board.

Conventionally, the position detecting element is usually sealed in a plastic package and mounted on a printed circuit board by an electronic component mounter, so that the position of the element in the package is displaced and the package is mounted. The position shift occurred at the time, and the position shift was larger than the target position. Also,
During resin molding, the circuit is moved by the injection pressure of the resin, and it is difficult to fix the circuit at a predetermined position. For this reason, the position detection signal is output at a shifted timing, and there are problems such as generation of motor vibration and noise due to torque ripple due to uneven motor current, and generation of noise from a motor mounted device. Was. Then, an object of the present invention is to provide a brushless motor for solving the above-mentioned problems.

[0015]

According to a first aspect of the present invention, there is provided a stator core having a plurality of slots, an insulating layer for insulating the stator core, and directly wound around the stator core via the insulating layer. A stator winding, a rotor having a permanent magnet housed in the center of the stator, a printed wiring board connected to the stator winding and mounted with electronic components for driving, and a printed wiring board. In a brushless motor provided with connected lead wires, a semiconductor component of the driving electronic components is bare-chip mounted and resin-sealed on the printed wiring board using a base material as a resin.

The semiconductor component includes a power semiconductor for supplying current to the stator winding, an IC for a pre-driver for driving the power semiconductor, an IC for waveform generation, and a position detecting element for detecting a magnetic pole position of the rotor. Is mentioned.

Further, in the brushless motor, the printed wiring board is a double-sided board provided with a circuit pattern having an area sufficiently larger than the area of the semiconductor component on the back surface on the mounting side of the mounted semiconductor component.

Further, in the brushless motor, the semiconductor component is constituted by a discrete component.

In the brushless motor, the lead wire drawn out of the brushless motor from the printed wiring board on which a position detecting element for detecting a magnetic pole position of the rotor is mounted is centered on the axis of the rotor. It is connected to the printed wiring board within an acute angle between the position detecting elements on the arc.

Further, in the brushless motor, the driving circuit is integrally molded with the stator core with resin.

Further, in the brushless motor, a holder for fixing the printed wiring board on which the position detecting element is mounted is provided, and a projection provided on the holder comes into contact with a molding die during resin molding so that the position is fixed. Things.

In the brushless motor, the holder may be provided with a fixing portion for the lead wire of the position detecting element, and the holder fixing portion may be fixed to the molding die by contact with the molding die during resin molding. It is.

In the brushless motor, the position detecting element is arranged at a position where a maximum magnetic flux density is obtained in a direction perpendicular to the shaft.

[0024]

Embodiments of the present invention will be described below with reference to the drawings. Embodiment 1. FIG. 1 is a cross-sectional view of a circuit for driving a brushless motor according to Embodiment 1 of the present invention, in which electronic components are mounted.
FIG. 2 is a perspective view of the electronic component mounting shown in FIG. In FIG. 1, reference numeral 1a denotes a base made of insulated inexpensive resin, 1b denotes a conductive portion made of copper foil or the like selectively formed on the base 1a, and 1c denotes a conductive part formed by the base 1a or the like. It is a through hole. Reference numeral 1 denotes the substrate 1a and the conductive portion 1b
And a printed wiring board including a through hole 1c and the like. Reference numeral 2 denotes a bare chip component obtained from a semiconductor wafer that is not packaged with plastic or the like, and reference numeral 3 denotes a wire that connects the bare chip component 2 to the conductive portion 1b.

4 is a bare chip part 2 and a wire wiring 3
5 is a protective resin having electrical insulation and heat resistance for protecting the semiconductor chip 5, and electrically connects and fixes the bare chip component 2 and a general surface mount component 6 such as a resistor and a capacitor to the conductive portion 1 b. For soldering. Reference numeral 7 denotes a connector connected to input and output power and signals between the printed wiring board 1 and a circuit outside the brushless motor. Here, the base material 1a is desirably formed of a material that is generally widely used and has excellent workability, such as a glass epoxy or a composite material.

In FIG. 2, reference numeral 1 d denotes a land provided on the base 1 a of the printed wiring board 1, and reference numeral 8 denotes a connection to a structure other than electronic components mounted on the printed wiring board 1, or 8 denotes a land. This is an insertion hole for mounting and fixing. Reference numeral 9 denotes a position detecting element provided on the base 1a and for detecting a magnetic pole position of the rotor. The brushless motor is driven by a three-phase inverter circuit using, for example, a dedicated IC or a microcomputer for the waveform generation unit, six power transistors and diodes for the inverter unit, and the like. Of the power semiconductors that make up the inverter section,
Transistors include bipolar transistors and MOS-
FET, IGBT, etc. are used. Here, for example, a case is shown in which a configuration is made using a three-phase inverter circuit, but a drive system other than the three-phase inverter circuit may be used.

The mounting accuracy can also be improved by mounting the position detecting element 9 on a bare chip. This is because the position detecting element 9 is generally packaged with plastic or the like, and when this is mounted on the printed wiring board 1, the mounting displacement inside the packaging and the packaging time when components are mounted are reduced. This is because mounting displacement occurs. By such mounting, it is possible to reduce the position detection shift of the rotor 14 and reduce the distortion of the current supplied to the motor caused by the position shift. This is remarkable in a high-performance driving method such as a driving method in which a motor current flows in a sine wave shape.

It is preferable that the area of the conductive portion 1b for mounting the power semiconductor bare chip component 2 energized to the stator winding is increased because a sufficient heat radiation effect is obtained. However, the area for mounting other electronic components is reduced. Not preferred. Therefore, the heat dissipation conductive portion 1b having a sufficiently larger area than the area of the bare chip component 2 is provided on the side of the printed wiring board 1 opposite to the surface on which the bare chip component 2 is mounted, so that the heat dissipation of the bare chip component 2 is improved. It may be.

Conductive part 1 for soldering bare chip part 2
b and the conductive portion 1b for heat radiation may be connected by a plurality of through holes 1c, or each power semiconductor which is a large heat source of the inverter circuit or of each drive circuit may be dispersed. You may comprise so that it may arrange | position.
According to the former, the thermal resistance can be reduced, and according to the latter, heat concentration is less likely to occur, and the heat radiation effect can be further improved. Here, the case of the single-sided mounting is shown, but the electronic parts may be mounted on both sides of the printed wiring board 1. In this case, the processing cost increases, the circuit board becomes thicker, and the motor becomes thicker, which is inferior to the case of single-side mounting.

As described above, in this embodiment, the bare chip component 2 is used, and the bare chip component 2 and the wire wiring 3 are used.
The semiconductor device is bare-chip mounted and resin-sealed, thereby eliminating the plastic package of the semiconductor component and mounting the drive circuit on the printed wiring board 1 with a small area. Can be realized.

Further, in the present embodiment, since only the inexpensive resin substrate having the base material 1a insulated is used as the printed wiring board 1, the wiring between the wiring 3 on the printed wiring board 1 and the winding of the stator is formed. Can be easily connected with the solder 5. As a result, it is possible to realize a reduction in material cost, a reduction in processing cost, and a reduction in the size of a drive circuit, a motor on which the drive circuit is mounted, and a device on which the motor is mounted.

In particular, since the power semiconductor and the control IC that require a large mounting area in the drive circuit are mounted on a bare chip, they can be mounted on a limited and small area, and the material cost of the printed circuit board can be reduced and packaging can be achieved. Cost, and downsizing of the circuit, the motor, and the device on which the motor is mounted.

FIG. 3 is a sectional view of a brushless motor incorporating a circuit in which the electronic components shown in FIGS. 1 and 2 are mounted. FIG.
1 and 2 denote the same or corresponding parts, 12 denotes a resin-molded stator, 13 denotes a shaft serving as a rotating shaft, 14 is fixed to the shaft 13, and a permanent magnet is provided. It is a rotor having. Reference numeral 15 denotes a bearing, 16 denotes a bracket, and 17 denotes a stator core having a plurality of slots. Reference numeral 18 is an insulator, 19 is a winding, and 20 is a pin. Bearing # 15 is attached to stator iron core 17 by insulator 18
A terminal of the winding 19 is connected to the pin 20 by soldering.

After the pins 20 are inserted into the insertion holes 8 of the printed wiring board 1, they are fixed by soldering and are electrically connected. The rotor 14 is disposed at the center of the stator core 17, and the shaft 13 is fixed by the bearing 15 fixed to the stator 12 and the bracket 16. The position detecting element 9 mounted on the printed wiring board 1
It is arranged near the rotor 14 so that the magnetic pole position of the rotor 14 can be accurately detected.

FIG. 4 is a front view of mounting the printed wiring board shown in FIGS. 2 and 3 on a holder, and FIG. 5 is a sectional view of mounting the printed wiring board shown in FIG. In FIG. 4, the position detecting elements 9 are mounted and arranged on the printed wiring board 1 on a circular arc centered on a shaft 13 which is a general mounting method at an electrical phase angle of 120 degrees. The mechanical angle at this time depends on the number of poles of the motor, and the more the number of poles, the smaller the angle.
The output signal of the position detecting element 9 and the power supply are output to the outside of the motor from the lead wire 23 connected to the printed wiring board 1 by the solder 5. Printed wiring board 1 and lead wire 2
3 is fixed to the holder 22.

As shown in FIG. 5, the holder 22 fixes the printed wiring board 1 and sandwiches the lead wires 23 so that stress is not applied to the soldering portion against tensile force from the outside of the motor. have. Holder 2
2 is provided with a fixing portion for the lead wire 23, and the holder fixing portion comes into contact with a molding die during resin molding of the motor and is fixed in position. Thereby, the lead wire 23 output to the outside of the motor can be fixed so as not to apply a stress to the soldering portion against the pulling force from the outside, and the resin leakage from the mold at the time of resin molding can be prevented. Can be prevented.

Here, a connection point of the lead wire 23 with the printed wiring board 1 is provided within an angle (2θ) formed by the position detecting element 9 about the shaft 13. The output signal output from the position detecting element 9 for detecting the magnetic pole position of the rotor 14 to the outside of the motor and the power supply lead wire 23 are within an acute angle between the position detecting element 9 about the shaft of the rotor 14. A connection portion with the printed wiring board 1 is provided, and is structured to be drawn out of the motor. For this reason, the area of the printed wiring board 1 on which the position detecting element 9 is mounted can be extremely reduced, and lead routing inside the motor can be minimized. Therefore, it is possible to reduce the material cost of the printed wiring board 1 and the lead wires 23 and the processing cost of the lead wire routing.

Further, the holder 23 for fixing the printed wiring board 1 is provided with the projections 2 perpendicular to the surface of the printed wiring board 1.
4 and a molding die and a projection 2 during resin molding of the motor.
The position is fixed with respect to the direction of the shaft 13 so that 4 contacts. As described above, since the projections 24 are provided on the holder 23 and the projections 24 are fixed by the molding die during resin molding of the motor, the position detection element 9 can be mounted as intended even in resin molding. The position of the rotor 14 can be accurately detected. As a result, it is possible to prevent generation of motor vibration and noise due to torque ripple caused by unevenness of the motor current, and generation of noise from a motor mounted device.

FIG. 6 is a cross-sectional view of a brushless motor in which the printed wiring board on which the position detecting elements shown in FIGS. In FIG.
The same reference numerals as those in FIGS. 3 to 5 indicate the same or corresponding parts. Of the lead wires 23, the output signal of the position detecting element 9 and the power supply line are on the printed wiring board 1,
9 and output from the stator 12 to the outside.

The rotor 14 is disposed at the center of the stator core 17, and the shaft 13 is connected to the stator 12 and the bracket 1.
It is fixed by the bearing 15 fixed at 6. The position detecting element 9 mounted on the printed wiring board 1
4 is arranged near the rotor 14 so that the position of the magnetic pole can be accurately detected.

FIG. 7 is a layout diagram of a rotor and a position detecting element and a magnetic flux density curve. The rotor 14 has a shaft 13
The permanent magnet 14a is provided with a position detecting magnet 14b for detecting the magnetic pole position by the position detecting element 9 on the side surface of the permanent magnet 14a in the direction of the shaft 13.

The rotor 14 is made of a plastic magnet rotor in which a magnetic material such as ferrite is integrally molded with nylon, and a permanent magnet 14a and a position detecting magnet 14b are formed at the same time. The outer circumference of the permanent magnet 14a is longer than the outer circumference of the position detection magnet 14b. Here, the position detection element 9 detects the magnetic flux density, and the detection accuracy decreases as the distance from the permanent magnet of the rotor 14 in the direction of the shaft 13 decreases, and the detection becomes impossible. This direction is generally located at a distance that does not cause a problem from the dimensions of the components such as the rotor 14 and the stator 12 and the machining accuracy.

On the other hand, the arrangement perpendicular to the shaft 13 is as follows:
At a certain position as shown in the magnetic flux density curve of FIG. 7, there is a point Bp where the magnetic flux density becomes maximum, and the relationship becomes smaller in the order of stator inner diameter> position detecting element mounting position> position detecting magnet outer diameter. . Thus, the position detecting element 9 is
The rotor 14 has a positional relationship of: stator inner diameter> position detecting element mounting position> position detecting magnet outer diameter.

Thus, the position detecting element 9 can be arranged at a position where the maximum magnetic flux density is obtained in the direction perpendicular to the shaft 13, so that the position detecting accuracy can be improved. As a result, it is possible to reduce the distortion of the motor energizing current caused by the position detection deviation, reduce the vibration and noise of the motor and the equipment on which the motor is mounted, and require tight tolerances for mounting dimensions. It can be manufactured without.

FIG. 8 is a magnet orientation diagram of the rotor. The rotor 14 viewed from the shaft direction shown in FIG. 8 is made of a plastic magnet rotor in which a magnetic material such as ferrite is integrally formed of nylon, and a permanent magnet 14a and a position detecting magnet 14b are simultaneously formed, and a magnet portion is formed. The orientation is shown. The permanent magnet 14a and the position detecting magnet 14b are magnetized in polar orientation and have the orientation as shown.

In the above embodiment, the stator core 1
The drive circuit may be formed integrally with the drive circuit 7 by using a thermosetting resin. This makes it possible to sufficiently radiate heat from a heating element such as a power semiconductor via the resin.

[0047]

According to the present invention, by mounting a semiconductor component on a bare chip and sealing with a resin, the plastic package of the semiconductor component is eliminated, and the drive circuit is mounted on the printed wiring board with a small area. Can be realized. In addition, by using only an inexpensive resin substrate whose base material is insulated as a printed wiring board,
For example, the wiring on the printed wiring board and the space between the windings of the stator can be easily connected by soldering. As a result, it is possible to realize a reduction in material cost, a reduction in processing cost, and a reduction in the size of a drive circuit, a motor on which the drive circuit is mounted, and a device on which the motor is mounted.

Further, the printed wiring board is constituted by a double-sided board having a circuit pattern having an area sufficiently larger than the area of the semiconductor component on the back surface on the mounting side of the mounted semiconductor component. Thus, heat can be sufficiently released from the heating element.

Further, by forming the semiconductor component as a discrete component, heat concentration hardly occurs.
Heat can be sufficiently released.

Further, the lead wire drawn out of the brushless motor from the printed wiring board on which the position detecting element for detecting the magnetic pole position of the rotor is mounted is connected to the arc on the arc around the axis of the rotor. By being configured to be connected to the printed wiring board within an acute angle sandwiched between the position detecting elements, the area of the printed wiring board on which the position detecting elements are mounted can be greatly reduced, and the motor internal In this case, it is possible to minimize the lead wire routing, thereby reducing the material cost of the printed wiring board and the lead wire, and the processing cost of the lead wire routing.

Further, since the drive circuit and the stator core are integrally formed of resin, the heat radiation of a heating element such as a power semiconductor can be sufficiently obtained through the resin.

Further, a holder for fixing the printed wiring board on which the position detecting element is mounted is provided, and the projection provided on the holder is fixed by contacting a molding die during resin molding. By doing so, this projection is fixed by a molding die at the time of resin molding, so that the position detecting element can be mounted as intended also in resin molding. For this reason, it is possible to accurately detect the position of the rotor, and it is possible to prevent the occurrence of motor vibration and noise due to torque ripple caused by uneven motor current, and the occurrence of noise from a motor-mounted device.

Further, the holder is provided with a fixing portion for the lead wire of the position detecting element, and the resin fixing portion is configured so that the holder fixing portion comes into contact with the molding die to fix the position. Thereby, the lead wire output to the outside of the motor can be fixed so as not to apply a stress to the soldered portion against the pulling force from the outside, and the resin can be prevented from leaking from the mold during resin molding. be able to.

Further, by arranging the position detecting element at a position where the maximum magnetic flux density is obtained in the direction perpendicular to the shaft, the position detecting accuracy can be improved. In addition to reducing the distortion of the motor conduction current caused by the motor, the vibration and noise of the motor and the equipment on which it is mounted can be reduced, and the mounting dimensions can be manufactured without requiring tight tolerances. it can.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a circuit for driving a brushless motor according to a first embodiment of the present invention, in which electronic components are mounted.

FIG. 2 is a perspective view of the electronic component mounting shown in FIG.

FIG. 3 is a cross-sectional view of a brushless motor including a circuit in which the electronic components shown in FIGS. 1 and 2 are mounted.

FIG. 4 is a front view of mounting the printed wiring board on which the printed wiring board on which the position detecting element is mounted is mounted on the holder;

FIG. 5 is a sectional view of the printed wiring board shown in FIG. 4;

FIG. 6 is a cross-sectional view of a brushless motor in which a printed wiring board on which the position detecting elements shown in FIGS.

FIG. 7 is a layout diagram of a rotor and a position detecting element and a magnetic flux density curve.

FIG. 8 is a magnet orientation diagram of a rotor.

FIG. 9 is a sectional view showing a conventional brushless motor.

FIG. 10 is a perspective view showing the stator core shown in FIG. 9;

FIG. 11 is a perspective view showing the printed wiring board shown in FIG. 9;

FIG. 12 is a perspective view showing the stator shown in FIG. 9;

FIG. 13 is an exploded perspective view showing another conventional brushless motor.

FIG. 14 is a sectional view showing the brushless motor shown in FIG.

[Explanation of symbols]

1 printed wiring board, 2 bare chip parts, 3 wire wiring, 4 protective resin, 5 solder, 6 surface mount components,
7 connector, 8 insertion hole, 9 position detecting element, 12
Stator, 13 shaft, 14 rotor, 14a permanent magnet, 14b position detecting magnet, 15 bearing, 16
Bracket, 17 stator core, 18 insulator, 19 winding, 20 pins, 22 holder, 23
Lead wire, 24 protrusions.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kazunori Sakanobe 2-3-2 Marunouchi, Chiyoda-ku, Tokyo Mitsui Electric Co., Ltd. (72) Kenji Kawagishi 2-2-2 Marunouchi, Chiyoda-ku, Tokyo No. 3 Mitsubishi Electric Corporation F-term (reference)

Claims (8)

[Claims] A stator core having a plurality of slots;
An insulating layer that insulates the stator core, a stator winding directly wound on the stator core via the insulating layer, a rotor having a permanent magnet housed in the center of the stator, A brushless motor including a printed wiring board connected to a slave winding and mounted with a driving electronic component, and a lead wire connected to the printed wiring board; A brushless motor characterized in that a semiconductor component among the driving electronic components is bare chip mounted and resin-sealed. 2. The brushless motor according to claim 1, wherein the printed wiring board is a double-sided board having a circuit pattern larger than an area of the semiconductor component on a back surface on a mounting side of the mounted semiconductor component. A brushless motor. 3. The brushless motor according to claim 1, wherein said semiconductor component is constituted by a discrete component. 4. The brushless motor according to claim 1, wherein the lead wire drawn out of the brushless motor from the printed wiring board on which a position detection element for detecting a magnetic pole position of the rotor is mounted is the same as that of the brushless motor. A brushless motor, wherein the brushless motor is connected to the printed wiring board within an acute angle between the position detection elements on an arc centered on the axis of a rotor. 5. The brushless motor according to claim 1, wherein a drive circuit and the stator core are integrally formed of resin. 6. The brushless motor according to claim 1, further comprising: a holder for fixing said printed wiring board on which said position detecting element is mounted, wherein a projection provided on said holder during resin molding has a molding metal. A brushless motor characterized by being fixed in position by contacting a mold. 7. The brushless motor according to claim 1, wherein a fixing portion of the lead wire of the position detecting element is provided on the holder, and the holder fixing portion is provided on the molding die during resin molding. A brushless motor characterized in that the position is fixed by contact. 8. The brushless motor according to claim 1, wherein the position detecting element is arranged at a position where a maximum magnetic flux density is obtained in a direction perpendicular to the shaft.