JPH07106479A - Heat pipe-type semiconductor radiator - Google Patents

Abstract

PURPOSE:To provide a heat pipe-type semiconductor radiator which is provided with the mounting structure of radiation fins of an excellent vibration-resistant property and whose reliability is excellent. CONSTITUTION:The radiator is provided with heat pipes 11 having heat- introducing parts and heat-discharging parts, with a thermal conductor 12 which is installed at the heat-introducing parts and which comes into contact with a semiconductor element and with radiation fins 15 which are installed at the heat-discharging parts for the heat pipes. That, the heat-discharging parts for the heat pipes are formed to be flat, the radiation fin is provided with a contact face coming into contact with the flat heat-discharging parts for the heat pipes, and the contact face for the radiation fin and the heat-discharging parts for the heat pipes are bonded by a soldering operation using a solder alloy material having a melting point at a temperature which is lower than a temperature at which the heat pipes are burst.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat pipe type semiconductor radiator, and more particularly to a semiconductor radiator mounted on an electric vehicle.

[0002]

2. Description of the Related Art A heat pipe type semiconductor radiator is a device for cooling a semiconductor device by utilizing the excellent heat transfer function of a heat pipe to release the heat generated by the semiconductor device to the outside.

A conventional heat pipe type semiconductor radiator is shown in FIG.
It is configured as shown in.

That is, the heat pipe 1 is formed of a round pipe having a circular cross section in the entire axial direction. The heat pipe 1 has a working fluid sealed therein, one end of which serves as a heat input portion and the other end of which serves as a heat radiating portion. A plurality of heat pipes 1 are arranged and provided. One heat conductor 2 of block type is provided in the heat input portion of each heat pipe 1.
Are provided in common, and the semiconductor element 3 is provided in contact with the heat conductor 2.

A plurality of heat dissipating fins 4 are commonly provided in the heat dissipating portion of each heat pipe 1. Conventionally, this radiation fin 4 is attached to the heat pipe 1 with the following configuration. The radiation fin 4 is made of a plate material, has a diameter slightly smaller than the diameter of the heat pipe 1, and has a plurality of burring holes 4a arranged side by side. Each heat pipe 1 is placed in the hole 4a of each radiating fin 4.
Are press-fitted, and as a result, each radiation fin 4 is fixed to each heat pipe 1.

In the heat pipe type semiconductor radiator, the heat generated in the semiconductor element 3 is transferred to the heat conductor 2 and further transferred from the heat conductor 2 to the heat input wall of the heat pipe 1. As a result, the working fluid enclosed in the heat pipe 1 and in the heat input portion is heated and evaporated.

The vapor obtained by this vaporization moves from the heat input portion of the heat pipe 1 to the heat radiating portion, releases heat in the heat radiating portion, condenses, and becomes the working fluid again. The latent heat released from the vapor is transferred to the wall of the heat dissipation portion of the heat pipe 1, further transferred to the heat dissipation fins 4 and released into the air. The working fluid is circulated from the heat radiating portion of the heat pipe 1 to the heat input portion.

[0008]

By the way, in recent years, the development of a pollution-free electric vehicle that uses electric power as a power source has become active in response to the demand for environmental protection. In this electric vehicle, an inverter-controlled electric motor is installed instead of the gasoline engine to drive the axles to rotate.

An electric vehicle is equipped with a drive control device for performing such driving. A power semiconductor element such as a power transistor is often used in this control device, and a lightweight and small heat pipe type semiconductor radiator is used to cool the semiconductor element.

The conventional heat pipe type semiconductor radiator has a structure in which the heat radiation fin 4 is attached to the heat pipe 1 by press-fitting the heat pipe 1 into the hole portion 4a of the plate-shaped heat radiation fin 4 as described above. However, when the heat pipe of this configuration is mounted on an electric vehicle, the following problems occur.

That is, the vibration generated in the vehicle body when the electric vehicle travels is also applied to the heat pipe type semiconductor radiator mounted in the vehicle body. When vibration is applied to the heat pipe type semiconductor radiator, the radiation fins vibrate.

Then, the mounting portion between the hole 4a of the heat radiation fin 4 and the heat pipe 1 press-fitted into the hole 4a is loosened, the mounting strength of the heat radiation fin 4 is lowered, and as a result, the function of the heat pipe is adversely affected. There is a problem that may affect.

The present invention has been made based on the above-mentioned circumstances, and the strength of the mounting portion between the heat radiation fin and the heat pipe is great and the vibration resistance is excellent, so that the vibration generated in the vehicle body when the electric vehicle is mounted is suppressed. An object of the present invention is to provide a heat pipe type semiconductor radiator that can exhibit excellent reliability.

[0014]

In order to achieve the above object, a heat pipe type semiconductor radiator according to the present invention comprises a heat pipe having a heat input portion and a heat radiation portion, and a semiconductor provided in the heat input portion of the heat pipe. A heat conductor in contact with the heat pipe, and heat radiation fins provided in the heat radiation part of the heat pipe, wherein the heat radiation part of the heat pipe has a flat cross section, and the heat radiation fin has a flat shape. A temperature lower than the temperature at which the contact surface of the heat dissipation fin and the flat surface of the heat dissipation part of the heat pipe have an abutment surface that abuts the flat surface of the heat dissipation part, and the heat pipe bursts due to internal vapor pressure. It is characterized by being joined by soldering using a solder alloy material having a melting point of.

[0015]

The heat radiating portion of the heat pipe is flattened in cross section, the abutting surface is formed on the radiating fin, and the abutting surface of the radiating fin is brought into contact with the flat surface of the radiating portion of the heat pipe. The radiating fins can be joined by soldering.

Further, by using the solder alloy material having a melting point lower than the temperature at which the heat pipe bursts, it is possible to solder the heat pipe and the radiation fin without impairing the function of the heat pipe.

Then, the flat surface of the heat dissipation portion of the heat pipe and the contact surface of the heat dissipation fin are soldered to firmly bond both surfaces. As a result, the radiating fins are firmly attached to the heat pipe, and the radiating fins do not come loose with respect to the heat pipe due to external vibration, and exhibit excellent vibration resistance. Therefore, it becomes possible to mount the heat pipe type semiconductor radiator on the body of the electric vehicle.

[0018]

EXAMPLES Examples of the present invention will be described.

A first embodiment of the heat pipe type semiconductor radiator of the present invention will be described with reference to FIGS. 1 to 4.

Reference numeral 11 in the figure denotes a heat pipe, which is made of a metal having a high thermal conductivity such as copper and has both ends closed, and has a working fluid such as water enclosed therein. There is.

One half of the heat pipe 11 is a circular part 11a having a circular cross section, and the remaining part is a flat part 11b having a flat cross section.
A pair of elongated flat surfaces 11c extending in the axial direction of the heat pipe 11 are formed on the flat portion 11b so as to face each other.
The circular portion 11a of the heat pipe 11 is used as a heat input portion, and the flat portion 11b is used as a heat radiation portion.

A plurality of heat pipes 11 are prepared, and each of the heat pipes 11 is vertically erected so that the circular portion 11a is on the lower side and the flat portion 11b is on the upper side, and arranged in parallel with each other.

A heat conductor 12 is a rectangular parallelepiped made of a metal such as aluminum. A plurality of pipe mounting holes 13 extending in the vertical direction are formed in the heat conductor 12 side by side at intervals in the longitudinal direction. A circular portion 11a, which is a lower portion of each heat pipe 11, is inserted and fixed in each pipe mounting hole 13.

A semiconductor element 14 such as a power transistor is attached in contact with the side surface of the heat conductor 12.

In the figure, numeral 15 is a heat radiation fin, which is a heat pipe 1.
The flat portions (heat radiating portions) 11b, which are the upper portions of the No. 1, are arranged on opposite sides of the opposing flat surfaces 1b. The radiating fin 15 has a corrugated shape, and is formed by folding back a plate material made of metal so that a plurality of horizontal fin portions 15a such as a copper alloy are continuous.

That is, the fin portion 15a having a rectangular plate shape
One side in the width direction is folded back at a right angle to form a flat folded back portion, and this folded back portion is folded back at a right angle and is overlapped with the fin portion 15a.
And the other side portion in the width direction of the fin portion 15a of this step is folded back at a right angle to form a flat folded portion.
As described above, the fin portions 15a having a plurality of stages are continuously formed.

By forming the horizontal fin portions 15a over a plurality of stages, a plurality of horizontal air passages are formed.

The contact surface 16 in which the folded-back portions located on either side of the fin portion 15a of each step contact the pair of flat surfaces 11c of the flat portion 11b of the heat pipe 11.
It is said that.

A pair of heat radiation fins 15 are provided on one side and the other side of the flat portion 11b which is the upper portion of each heat pipe 11.
The respective contact surfaces 16 are arranged so as to face the flat surface 11c of each flat portion 11b. Then, as shown in FIG. 4, the pair of flat surfaces 11c of the flat portion 11b of each heat pipe 11 and the contact surface 16 of each radiating fin 15 are joined by soldering.

The alloy material 17 used for this soldering is a solder alloy material having a melting point lower than the temperature at which the heat pipe 11 is heated and bursts. Specific examples thereof include Sn-Pb-based solder materials.

In the heat pipe type semiconductor cooler thus constructed, the heat generated in the semiconductor element 14 is transferred to the heat conductor 12 and further transferred to the wall of the circular part 11a which is the heat input part of the heat pipe 11. To be done. As a result, the hydraulic fluid in the circular portion 11a of the heat pipe 11 is heated, evaporated and vaporized. The vapor obtained by this vaporization rises from the circular portion 11a of the heat pipe 11 and moves to the flat portion 11b, which is a heat radiating portion, and the flat portion 11b releases heat and condenses into the working fluid again.

The heat released from the steam is the heat pipe 11
Is transmitted to the walls of the pair of flat surfaces 11c of the flat portion 11b, further transmitted to the fin portions 15a of the pair of heat radiation fins 15 and discharged into the air. Air flows between the fin portions 15a of each radiating fin 15 so that heat can be efficiently transferred from each fin portion 15a to the air. The hydraulic fluid moves from the heat radiation part of the heat pipe 1 to the heat input part.

As a result, the heat of the semiconductor element 14 is efficiently radiated into the air to cool the semiconductor element.

The heat radiating portion of the heat pipe 11 has a flat cross section to form a flat surface 11c, and the heat radiating fin 15 is brought into contact with the surface 16 thereof.
And the contact surface 16 of the heat radiation fin 15 is brought into contact with the flat surface 11c of the flat portion 11b which is the heat radiation portion of the heat pipe 11, so that the heat pipe 11 and the heat radiation fin 15 are formed.
It is possible to join and by soldering.

Further, by using a solder alloy material having a melting point lower than the temperature at which the heat pipe 11 bursts, it is possible to solder the heat pipe 11 and the radiation fin 15 without impairing the function of the heat pipe 11. It is possible.

The flat surface 11c of the heat radiating portion of the heat pipe 11 and the contact surface 1 of the radiating fin 15 with the flat surface 11c.
By soldering 6 and 6, both surfaces are firmly joined. As a result, the radiating fins 15 become
It is firmly attached to the radiating fin 15 by external vibration.
Exhibits excellent vibration resistance without causing slack in the heat pipe 11.

Therefore, the heat pipe type semiconductor radiator of the present embodiment can be mounted on an electric vehicle and used reliably without the radiation fins vibrating and loosening.

Since the heat radiating portion of the heat pipe 11 is a flat portion, the pressure loss of the air flowing between the fin portions 15 of the heat radiating fin 15 can be reduced.

The second embodiment will be described with reference to FIG.

This embodiment differs from the first embodiment in the structure of the heat dissipation section. 5, the same parts as those in FIG. 1 are designated by the same reference numerals.

In this embodiment, a radiation fin 21 in which a large number of horizontal air passage holes 22 are arranged in a grid pattern is used. The side surface of the heat radiation fin 21 is a contact surface 23 that contacts the flat surface 11c of the flat portion 11b of the heat pipe 11.

When the heat radiation fin 21 is manufactured, for example, the whole heat radiation fin 21 is divided into a plurality of sections, a single section is molded by extrusion molding, and the molded extrusion molded body is formed with a common length. It is rational to cut and form a plurality of sections, and then stack a plurality of formed blocks and join them to each other by means such as soldering or brazing.

The radiating fins 21 are provided on one side and the other side of the flat portion 11b, which is the upper portion of each heat pipe 11.
The respective contact surface portions 16 are arranged so as to face the flat surface 11c of each flat portion 11b. Further, the flat surface 11b of each heat pipe 11 and the upper surface portion 11c on the other side thereof and the contact surface 23 of each heat radiation fin 21 are joined and fixed by soldering.

The third embodiment will be described with reference to FIG.

This embodiment differs from the first embodiment in the structure of the heat dissipation section. 6, the same parts as those in FIG. 1 are designated by the same reference numerals.

In this embodiment, the radiation fins 31 in which a large number of horizontal air passage holes 32 are arranged in a grid are used. The side surface of the heat radiation fin 31 is a contact surface 33 that contacts the flat surface 11c of the flat portion 11b of the heat pipe 11.

When the heat radiation fin 31 is manufactured, for example, the whole heat radiation fin 31 is divided into a plurality of sections, a single section is molded by extrusion molding, and the molded extrusion molded body is formed into a common length. A rational method is to cut and form a plurality of sections, and then stack the formed sections and join them by means such as soldering or brazing.

The radiating fins 31 are provided on one side and the other side of the flat portion 11b which is the upper portion of each heat pipe 11.
The respective contact surface portions 16 are arranged so as to face the flat surface 11c of each flat portion 11b. Further, the flat surface 11b of each heat pipe 11 and the upper surface portion 11c on the other side thereof and the contact surface 33 of each radiating fin 31 are joined and fixed by soldering.

Next, a specific example will be described.

A heat pipe semiconductor radiator according to the first embodiment shown in FIG. 1 was manufactured.

The heat pipe 11 was made of a copper alloy. The total length of the heat pipe 11 is 450 mm, and the diameter of the circular part is 1.
5.88mm, length 150mm, flat part thickness 10mm, width 2
The length is 0 mm and the length is 300 mm.

The heat conductor 12 is made of aluminum and has a length of 150 mm, a width of 110 mm, and a thickness of 25 mm. The semiconductor element 14 is a power transistor module.

The radiation fins 15 are formed by bending a plate material made of aluminum alloy and having a thickness of 0.5 mm. The fin portion 15a has a length of 180 mm, a width of 50 mm, and an interval of 5 mm is 60 mm.
Formed by folding.

The present invention is not limited to the above-described embodiment, but can be modified in various ways.

[0055]

As described above, according to the heat pipe type semiconductor radiator of the present invention, the strength of the mounting portion between the heat radiation fin and the heat pipe is large and the vibration resistance is excellent, and thus when the electric vehicle is mounted. It is possible to exhibit excellent reliability against vibration generated in the vehicle body.

[Brief description of drawings]

FIG. 1 is a perspective view showing a heat pipe type semiconductor radiator according to a first embodiment of the present invention.

FIG. 2 is a front view showing the heat pipe type semiconductor radiator of the embodiment.

FIG. 3 is a side view showing the heat pipe type semiconductor radiator of the embodiment.

FIG. 4 is a plan view showing the heat pipe type semiconductor radiator of the embodiment.

FIG. 5 is a perspective view showing a heat pipe type semiconductor radiator according to a second embodiment.

FIG. 6 is a perspective view showing a heat pipe type semiconductor radiator according to a third embodiment.

FIG. 7 is a diagram showing an example of a conventional heat pipe type semiconductor radiator.

[Explanation of Codes] 11 ... Heat Pipe, 12 ... Heat Conductor, 14
... Semiconductor element, 15 ... Radiation fin, 16 ...
Contact surface, 21 ... Radiating fin, 31 ... Radiating fin.

Claims (1)

[Claims] 1. A heat pipe having a heat input portion and a heat radiation portion, a heat conductor provided in the heat input portion of the heat pipe and in contact with a semiconductor, and a heat radiation fin provided in the heat radiation portion of the heat pipe. The heat radiating portion of the heat pipe is formed to have a flat cross section, and the heat radiating fin has a contact surface that abuts a flat surface of the heat radiating portion of the heat pipe.
The contact surface of the heat dissipation fin and the flat surface of the heat dissipation portion of the heat pipe are joined by soldering using a solder alloy material having a melting point lower than a temperature at which the heat pipe bursts. Characteristic heat pipe type semiconductor radiator.