JP2843530B2 - Electronic component cooling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for cooling an electronic component such as an integrated circuit which is heated by operation, particularly a component which is mounted on a compact device by utilizing heat generated by the integrated circuit. is there.

[0002]

2. Description of the Related Art Recently, the integration density of ICs, especially CPUs, has been remarkably improved, and the processing speed has been increased. Therefore, notebook-type personal computers and word processors are compactly put on the market. If the temperature is increased to 125 ° C. without cooling such a semiconductor element, the circuit will be destroyed. Therefore, in a typical desktop type personal computer using a household power supply, fan motors are provided in various places to cool the semiconductor elements that have generated heat because there is enough power supply, and this is started from the time when the computer switch is turned on. It is known to operate and cool the integrated circuit so that it does not generate too much heat.
However, the cooling fan is not installed as an unnecessary part because the notebook type personal computer and word processor mentioned above are configured so that they can be used with a battery and because they are manufactured with the concept of wanting to compact as much as possible It is configured to cool by a natural air cooling system. Further, the present applicant has previously described a type in which the thermoelectric element 2 and the fan motor 5 are directly connected as shown in FIGS. 7 and 8, and when a predetermined temperature difference occurs between the thermoelectric elements 2, the fan motor 5 is rotated. Invented a cooling device (Jpn.
5-61862).

[0003]

In the above invention, the fan motor is rotated when cooling is required. The power source of the fan motor is a temperature difference between the surface of the semiconductor element and the temperature on the heating side of the thermoelectric element. This utilizes the electromotive force of the thermoelectric element. For this reason, the thermoelectric element does not generate an electromotive force unless the temperature difference becomes, for example, 10 ° C. or more. Therefore, the above-described conventional technology has a problem that the cooling operation tends to be delayed and the cooling effect is not sufficient. The present invention has been made in view of the drawbacks of the related art, and enables a semiconductor device incorporated in a compact personal computer such as a notebook type or a word processor to operate a fan motor without obtaining power supply from a power supply. It is to provide a cooling device. It is still another object of the present invention to provide a cooling device that can operate a fan motor for a longer period of time as compared with a direct connection type thermoelectric element.

[0004]

That is, a first aspect of the present invention is a thermoelectric element joined to the upper surface of an electronic component such as a semiconductor element, a fan motor forming a closed circuit with the element, and a fan of the closed circuit. Power storage means connected in parallel with the motor;
A temperature detector mounted on the semiconductor element, a semiconductor element based on a detection result of the temperature detecting means supplying a current to the fan motor when overheated to _one or more predetermined temperature T, the semiconductor device is a predetermined temperature T ₂ (T ₁ ≧ T ₂ ) An electronic device comprising control means for interrupting the flow of current to the fan motor when less than and a fan joined to the drive shaft of the fan motor, wherein the heating side of the thermoelectric element is brought into contact with the semiconductor element side. The present invention according to claim 2 is an electronic component cooling device in which a fan motor and a fan are mounted on the thermoelectric element at a predetermined interval from the thermoelectric element via a frame, and Achieve this objective.

[0005]

In the apparatus according to the present invention, when a word processor, a personal computer, or the like incorporating the semiconductor element is operated, the semiconductor element gradually generates heat by performing the arithmetic processing many times. The current generated by the temperature difference between the thermoelectric element and the cooling part of the device flows into the electric storage means and is charged. As a result, the electric storage means is charged with an electric charge sufficient to rotate the fan motor. And when the semiconductor device is heated to a predetermined temperature above T _1, the state has been detected temperature detection means, the detection result of the temperature detecting means is transmitted to the control means, the control means of the power supply to the fan motor Start. Then, the semiconductor element will be gradually cooled, drops to a predetermined temperature T ₂ which stable operation is promised. Then, the control unit detects the state via the temperature detection unit, cuts off the power supply to the fan motor, and charges the power storage unit. As a result, the power storage unit is charged with electric charge enough to drive the fan motor at all times.

Therefore, even if the processing by the electronic device is stopped or the switch of the personal computer or the like is turned off, the fan motor continues to operate when the semiconductor element is overheated to a predetermined temperature or more, and the semiconductor element is always abnormally heated. Never do.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the illustrated embodiments. In the figure, reference numeral 1 denotes a semiconductor element (electronic component) in which an IC or the like is incorporated, and a heating side of a thermoelectric element 2 utilizing the Seebeck effect is joined to the center of the surface of the semiconductor element 1 via a first radiator 3. A large number of radiating pins 3a of the first radiator 3 are connected around the thermoelectric element 2 at predetermined intervals so that the height of the pin 3a is substantially the same as that of the thermoelectric element 2. As shown in FIG. 5, the first radiator 3 has a flat section 8 which connects the central thermoelectric element 2 and an air passage section 9 which extends in the vertical and horizontal directions of the section 8. Are connected in a large number.
1 and 6, a second radiator 10 formed substantially in a cross shape is joined to the cooling-side surface of the thermoelectric element 2. The radiator 10 is formed by using a radiating pin 10a or the like. This is for cooling the cooling side of the thermoelectric element 2 more efficiently.

Next, the semiconductor device 1 has substantially the same shape as the semiconductor device 1 so that the thermoelectric device 2 and the first radiator 3 are located at a predetermined distance from each other via columns joined to the four corners of the semiconductor device 1. A DC type fan motor 5 that can be driven with very small electric power is suspended from the upper center of the frame 4 with its drive shaft 5a facing downward. The fan motor 5 is selected to operate sufficiently with electric power of, for example, about 1.5 V and about 0.1 A. The size of the thermoelectric element 2 is determined by the size of the semiconductor element 1 to be mounted. For a semiconductor element having a size of 40 mm × 40 mm or the like, a size of about 10 mm to 15 m × 10 mm to 15 mm is used. As a result, the temperature difference from the cooling side is 10 ° C.
In some cases, an output of about 1 to 5 watts can be obtained. A fan 6 is mounted on a drive shaft 5 a of the fan motor 5. In addition, a circular vent 7 is opened below the frame 4 as shown in FIG. 4, and the air flow generated by the operation of the fan motor 5 is connected to the second radiator 10 connected to the thermoelectric element 2. And it is comprised so that it may be blown toward the first radiator 3. Reference numeral 12 in the figure denotes a lead wire for connecting the thermoelectric element 2 and the fan motor 5 to form a closed circuit.

FIG. 2 is a block diagram showing the structure of an electric circuit according to an embodiment of the present invention, in which a thermoelectric element 2, a transistor 14, and a fan motor 5 are connected in a closed circuit. 16 is a collector side of the transistor 14 and the motor 5
And a storage means (capacitor) connected in parallel. 18
Is a temperature detecting means such as a thermistor mounted on the semiconductor element 1
Control means for turning on / off the fan motor 5 based on the detection result from the control unit 17. The control means 18 drives the fan motor 5 when the temperature of the semiconductor 1 exceeds a predetermined temperature T1 (for example, 70 ° C.). And the output side thereof is connected to the base of the transistor 14 so as to generate an energization signal for stopping the fan motor 5 when the temperature falls below a predetermined temperature T2 (for example, 50 ° C.). At this time, a current flows from the collector to the emitter, and the energization state is controlled so that no current flows from the collector to the emitter when the temperature is lower than the predetermined temperature T2. In addition, 20 is the power storage means 16
This is a diode for preventing electricity from flowing back into the thermoelectric element 2 from the back. In the present embodiment, the control temperatures are set as T1 and T2, but the present invention is not limited to this, and T1 and T2 may be configured to have the same temperature.

In the cooling device according to the present embodiment having the above-described configuration, the semiconductor device 1 is gradually heated by using the device having the semiconductor device 1 mounted thereon, and is gradually heated from a normal temperature state to 50 ° C. or more. Is done. Then, a temperature difference occurs between the heating side and the cooling side of the thermoelectric element 2 connected to the semiconductor element 1, and an electromotive force occurs in the thermoelectric element 2. But,
Initially, this electromotive force is not enough to rotate the fan motor, and the semiconductor element has not reached an abnormally overheated state. Therefore, the control means 18 does not recognize the energization of the fan motor 5, but flows a current toward the power storage means 16 by the electromotive force generated from the thermoelectric element 2 to charge the power storage means 16. As a result, electric charges sufficient to drive the fan motor 5 are stored in the electric storage means 16. Result of the fan motor 5 continues the operation using the or semiconductor element 1 does not rotate, the semiconductor device is rapidly temperature rises, becomes a predetermined temperature above T _1. Then, the temperature detecting means 17 detects the state, and the control means 18 applies a voltage to the base so as to permit the power supply from the power storage means 16. The electric current flows from the electric storage means 16 toward the motor 5, and the motor 5 rotates. As a result of the rotation of the fan motor 5, the temperature of the semiconductor element 1 is gradually cooled. During this time, the electric charge for charging continues to flow from the thermoelectric element 2 mounted on the semiconductor element 1 to the electric storage means 16, so that the electric charge of the electric storage means 16 does not suddenly decrease. And when the temperature of the semiconductor element 1 is cooled to below the predetermined temperature T _2, the control means 18 via the temperature detection means 17 detects this, the fan motor in order to stop the voltage addition to the base of the transistor 14 The rotation of 5 will stop. Even while the fan motor 5 is stopped, current continues to flow from the thermoelectric element 2 to the power storage means 16 and charging is performed. As described above, since the rotation of the fan motor 5 is turned ON / OFF due to the overheating state of the semiconductor element 1, the fan motor 5 continues to be driven intermittently.

The rotational force of the fan motor 5 is determined by the potential difference of the electric storage means 16, and the higher the temperature difference, the faster the rotational speed. When the temperature difference between the thermoelectric elements 2 becomes small, the electromotive force is insufficient to rotate the fan motor 5, so that the rotation stops in the direct connection type. However, in the device of this embodiment, since the surplus current is charged through the power storage means 16 as described above, even if the electromotive force of the thermoelectric element 2 drops, the potential difference of the power storage means 16 is sufficient. The fan motor 5 will continue to rotate.

The operation of the fan motor 5 causes the fan 6
Rotates to generate wind toward the semiconductor element 1 and the radiators 3 and 10, thereby releasing warm air from a ventilation window provided in the apparatus for ventilating the inside and outside, and inhaling cool air from outside. In this embodiment, a cross-shaped second radiator 10 is joined to the surface of the thermoelectric element in consideration of the fact that the wind does not directly blow from the fan 6 to the thermoelectric element 2 located below the fan motor 5. Therefore, the fan 6 is also cooled by the blowing action. Further, the fan 6 is also directly connected to the heat radiating pins 3a of the first radiator 3 joined to the surface of the semiconductor element 1.
Is blown, and as a result, the semiconductor element 1
The cooling is more efficiently performed by the pins 3a of the first radiator 3.

Further, since the radiator 3 is provided with the air passage section 9 as shown in FIG. 5, air flows through the passage formed by the section 9 and the pin 3a, and the The vicinity of the element 2 is also cooled.
The heating side and the cooling side of the thermoelectric element 2 are always connected to the second side radiator 10 on the cooling side and the radiator having the pin is not joined on the heating side. Since the cooling side is cooled from the heating side, a temperature difference occurs between the two, so that the fan motor 5 can be operated more efficiently and the semiconductor element 1 can be cooled. Specifically, the semiconductor device surface was heated to 70 ° C. under the same conditions for comparison with and without the cooling device of the present embodiment under the same conditions. Although it was not possible to lower the temperature, it was possible to lower the temperature to 50 ° C. or lower in the case where the cooling device was installed. Incidentally, the amount of air blown by the cooling fan 6 of this embodiment is about 0.25 m ³ / min. At the maximum.

In the present embodiment, the first radiator 3 is interposed when the thermoelectric element is mounted on the semiconductor element 1. However, the present invention is not limited to this, and the first radiator 3 is not interposed. Needless to say, it may be configured so as to be directly joined to the substrate. Also, the second radiator on the thermoelectric element
Although the configuration is such that the radiator 10 is joined, the present invention is not limited to this, and the radiator 10 may not be provided.

[0015]

As described above, the cooling device for a semiconductor device according to the present invention differs from the conventional system in which electric power is supplied from a power source to operate a blower fan, and a fan is directly mounted on a semiconductor device. The device is configured so that the electromotive force is charged in advance to the power storage means by the thermoelectric element mounted on the semiconductor element, and the ON / OFF of the drive of the fan is performed based on the temperature of the semiconductor element, so that efficient cooling is performed. Can be.

[Brief description of the drawings]

FIG. 1 is a side sectional view of an apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a circuit for driving a fan.

FIG. 3 shows a temperature difference of a thermoelectric element according to an embodiment of the present invention;
5 is a time chart illustrating a relationship between a power storage unit and a fan motor.

FIG. 4 is a plan view showing a state where a fan is mounted on a semiconductor element.

FIG. 5 is a sectional view taken along line AA of FIG. 1;

FIG. 6 is a sectional view taken along the line BB of FIG. 1;

FIG. 7 is a schematic diagram of a thermoelectric element direct connection type circuit.

FIG. 8 is a time chart showing the relationship between the temperature difference of the thermoelectric element, the electric storage means, and the fan motor in the thermoelectric element direct connection type circuit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Semiconductor element 2 Thermoelectric element 3 First radiator 4 Frame frame 5 Fan motor 6 Fan 7 Vent 8 Section 9 Air passage section 10 Second radiator 12 Lead wire 14 Transistor 16 Electric storage means 17 Temperature detection means 18 Control means 20 Diode

Claims (2)

(57) [Claims] 1. A thermoelectric element (2) joined to an upper surface of an electronic component such as a semiconductor element, and a fan motor (5) forming a closed circuit with the element (2).
A power storage means (16) connected in parallel with the closed-circuit fan motor (5); a temperature detection means (17) mounted on the semiconductor element; and a semiconductor based on a detection result of the temperature detection means (17). When the element overheats to a predetermined temperature (T1) or more, a current flows to the fan motor and the semiconductor element
2) a control means (18) for interrupting the flow of current to the fan motor when the temperature is less than (2); and a fan (16) joined to a drive shaft of the fan motor (5), for heating the thermoelectric element (2). An electronic component cooling device characterized in that the side is in contact with the semiconductor element side. 2. A fan motor (5) and a fan (6).
The electronic component cooling device according to claim 1, wherein the device is mounted on the thermoelectric element (2) at a predetermined distance from the thermoelectric element (2) via the frame (4).