JPH07254672A - Cooling unit for semiconductor device - Google Patents

Abstract

PURPOSE:To cool a semiconductor device forcibly and effectively without consuming power by disposing a fan, comprising members deformable depending on the temperature variation, such that the members respond to the heating of semiconductor device. CONSTITUTION:Upon operation of an IC 1 mounted on the surface of a printed wiring board 5, the IC 1 is heated and the temperature thereof rises. The heat 7 is emitted from a package 2 and transmitted through an adhesive layer 14 to the base 12 thence transmitted to a large number of fins (temperature sensitive deformable members) 13 of a fan 10 and dissipated effectively therefrom. When the atmosphere having raised temperature surrounds the group of fins 13 and the temperature thereof reaches a preset level, the fins 13 are deformed into a previously stored shape. Since energy is consumed at the time of deformation, the temperature of the fins 13 lowers. Furthermore, the fins 13 are deformed to swing a fan thus producing a wind 8. Consequently, the atmosphere around the group of fins 13 is exchanged and the fins 13 are cooled.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor device cooling device, and more particularly to a technique for forcibly cooling the semiconductor device by air.
For example, the present invention relates to a semiconductor integrated circuit device (hereinafter referred to as a surface mount type IC) provided with a surface mount type package, which is effectively used for air cooling.

[0002]

2. Description of the Related Art In recent years, as the degree of integration of semiconductor integrated circuit devices has increased, there have been cases in which the cooling effect becomes insufficient with only natural air cooling. Especially surface mount type IC
Is surface-mounted on the printed wiring board, and natural air cooling alone tends to have an insufficient cooling effect.

Therefore, Japanese Utility Model Laid-Open No. 64-18747 proposes a package for an integrated circuit in which an axial blower type micro fan is mounted on the upper surface of a semiconductor device.

Japanese Utility Model Publication No. 60-12320 discloses a cooling system in which a fan is mounted on the upper surface of a base having an outer shape equivalent to that of a DIP IC (an integrated circuit device having a dual in-line package). Fans are proposed. By mounting this cooling fan together with the integrated circuit device in a region of the printed wiring board where heat generation density is high, the cooling fan locally and forcibly cools the region where heat generation density is high.

Further, Japanese Utility Model Laid-Open No. 62-23469 discloses a fan using a bimorph in which a thin plate-shaped common electrode is sandwiched between a pair of piezoelectric elements, and the common electrode is sandwiched between a pair of piezoelectric elements. A bimorph fan has been proposed which is composed of a sandwiched portion to be worn and a fan-shaped portion which is connected to the free end side of the sandwiched portion and has a width wider than that of the sandwiched portion. According to this bimorph fan, since the free end side of the common electrode in the bimorph is the fan part, the fan part can be activated by the voltage applied to the bimorph to send the wind to the object to be cooled. It can be manufactured inexpensively with a simple structure.

[0006]

However, in the above-described conventional semiconductor device cooling techniques, there is a problem in that power is consumed for cooling.

An object of the present invention is to provide a cooling device for a semiconductor device, which can cool the semiconductor device extremely forcibly and effectively without consuming electric power.

The above and other objects and novel features of the present invention will be apparent from the description of this specification and the accompanying drawings.

[0009]

The typical ones of the inventions disclosed in the present application will be outlined below. That is, a temperature-sensitive deformable member that uses a temperature-sensitive deformable material whose shape changes with temperature changes is attached to a semiconductor device so as to be sensitive to heat generated by the semiconductor device, and the deformation of the temperature-sensitive deformable member causes ventilation. The air blower is attached to the semiconductor device.

[0010]

In the above-mentioned means, when the temperature-sensitive deformable member is deformed in response to the heat generation of the semiconductor device, it is ventilated by the ventilator, and the ventilation cools the semiconductor device forcibly and extremely effectively. Moreover, since the heat generation itself of the semiconductor device is consumed for the deformation of the temperature-sensitive deformable member, the semiconductor device is also cooled by the deformation itself of the temperature-sensitive deformable member. Then, the temperature of the semiconductor device is relatively lowered by this cooling, so that the temperature-sensitive deformable member is deformed in the opposite direction and is ventilated by the fan. That is, according to the above-mentioned means, the heat is generated from the semiconductor device, and the wind is generated, so that the power is not consumed for cooling.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a surface mount type I which is an embodiment of the present invention.
The cooling device for C is shown, (a) is a front view, (b) is a front view which shows an operating state. FIG. 2 is a perspective view thereof.

In this embodiment, the semiconductor device cooling apparatus according to the present invention is configured to forcibly cool the surface-mounted IC 1 by air. The surface mount type IC 1 as an object to be cooled includes a surface mount type package 2 including a package body 3 and outer leads 4. The package body 3 is made of a resin having an epoxy resin as a main component and integrally molded into a substantially square flat plate shape by a transfer molding method. A semiconductor pellet (not shown) in which a semiconductor integrated circuit is formed, An inner lead (not shown) electrically connected to the pellet is resin-sealed. Many outer leads 4 are package main body 3
Are arranged on one side in the longitudinal direction in one row and arranged at equal pitch. Further, each outer lead is bent and formed in a gull wing shape.

The surface-mounted IC 1 is surface-mounted on the mounting surface of the printed wiring board 5. That is, a land (not shown) is provided on the mounting surface of the main body 6 of the printed wiring board 5.
Are arranged so as to correspond to the outer leads 4,
It is formed by a screen printing method or the like. And
With the outer lead 4 group in contact with this land group,
By performing the reflow soldering process, each outer lead 4 is electrically connected to each land, and the surface mount IC 1 is mechanically connected to the printed wiring board 5.

In the present embodiment, the surface-mounting IC cooling device 10 is provided with a fan-shaped fan 11 formed in a radiation fin structure, and is fixed to the surface-mounting package 2 of the surface-mounting IC 1. It is attached. That is, the air blower 11 includes a base 12 having a planar shape that is substantially the same as the planar shape of the surface-mounting type package 2. A large number of fins 13 are arranged on the upper surface of the base 12 in parallel with each other and are directed vertically upward. Is projected on. The lower surface of the base 12 is adhered to the upper surface of the surface mount type package 2 via an adhesive layer 14. The adhesive layer 14 is formed by using an adhesive having good thermal conductivity.

Each fin 13 of the fan 11 is formed in a rectangular thin plate shape by using a shape memory alloy as a temperature-sensitive deformable material whose shape changes according to a temperature change, and has a plate shape on the upper surface of the base 12. Are arranged side by side in parallel with each other, with the front and back surfaces thereof oriented horizontally. Therefore, the fin 13 substantially constitutes a temperature-sensitive deformable member. Fins made of shape memory alloy (hereinafter sometimes referred to as temperature-sensitive deformable member)
Deformation shape 13 is stored so as to be reversibly deformed alternately in a thickness direction (left-right direction) in an arc shape in cross section at a predetermined temperature (for example, 50 ° C.). That is, the temperature-sensitive deformable member 13 is responsive to a temperature change in which the ambient temperature of the surface-mounted package 2 and the temperature-sensitive deformable member 13 rises and falls below a predetermined temperature, and is alternately deformed left and right like a fan. The deformed shape is stored. Therefore, in the present embodiment, the ventilator 11 has the temperature-sensitive deformable member 13
It is composed of itself.

The operating temperature of the temperature-sensitive deformable member 13 is not limited to one temperature and may be an upper limit temperature (for example, 100 ° C.) and a lower limit temperature (for example, 50 ° C.). Alternatively, the temperature range may be set with an appropriate margin. In addition, the base 1 of the ventilator 11
2 may also be integrally formed with the temperature-sensitive deformable member 13 by a shape memory alloy. Further, as the temperature-sensitive deformable material, not only the shape memory alloy is used but also a bimetal formed by joining a plurality of thin plates made of materials having different thermal expansion coefficients may be used. Then, it is desirable to use a material having good thermal conductivity as the temperature-sensitive deformable member.

Next, the operation will be described. Printed wiring board 5
When the surface mount IC 1 mounted on the surface mount IC 1 is operated, the surface mount IC 1 generates heat and its temperature rises, and heat 7 is radiated from the surface mount package 2 and the base of the air blower 10 is also released. Heat is conducted to 12 via the adhesive layer 14. The heat 7 conducted to the base 12 is the fan 10
The heat is conducted to a large number of fins (temperature-sensitive deformable members) 13 in. Since the large number of fins 13 has an extremely large surface area, heat is effectively radiated from the large number of fins 13 to the surroundings. Therefore, surface mount type I
C1 is first cooled by the heat radiation effect of the large number of fins 13.

The ambient atmosphere heated by the heat radiation effect of the fins 13 stays in the fins 13 and the surface mount type I
When the heat generated by C1 exceeds the heat dissipation effect of the fin 13 group, the temperature of the fin 13 as the temperature-sensitive deformable member rises. When the temperature of the temperature-sensitive deformable member 13 reaches or exceeds a preset operating temperature, as shown in FIG. 1 (b),
The temperature-sensitive deformable member 13 changes into a shape stored in advance. Since energy is consumed with this change in shape, the temperature of the temperature-sensitive deformable member 13 drops. Further, since the temperature-sensitive deformable member 13 deforms like a fan,
As shown in FIG. 1B, wind 8 is generated.
This wind 8 exchanges the ambient atmosphere of the temperature-sensitive deformable member group 13 between old and new, and the cold and fresh air cools the temperature-sensitive deformable member 13. Since the heat radiation effect of the fins 13 is recovered by cooling the ambient atmosphere and cooling the temperature-sensitive deformable member that is the fins 13, the surface mount type package 2 is effectively cooled again.

On the other hand, when the temperature of the temperature-sensitive deformable member 13 drops and reaches the preset operating temperature or less,
As shown in (a), the temperature-sensitive deformable member 13 changes to the original shape stored in advance. Since the temperature-sensitive deformable member 13 deforms like a fan, wind 8 is generated as shown in FIG. This wind 8 exchanges the ambient atmosphere of the temperature-sensitive deformable member 13 group between old and new.

After that, when the ambient atmosphere heated by the heat radiation effect of the fins 13 stays in the fins 13 and the heat generated by the surface-mounted IC 1 exceeds the heat radiation effect of the fins 13, the temperature-sensitive deformable member. The temperature of the fin 13 rises again. When the temperature of the temperature-sensitive deformable member 13 reaches or exceeds a preset operating temperature, the temperature-sensitive deformable member 13 changes to a pre-stored shape as shown in FIG. Is generated again. After that, the cooling device 10 forcibly and effectively cools the surface-mounted IC 1 by repeating the above operation.

In this way, in this embodiment, the surface mount IC 1 is forcibly and effectively cooled by the semiconductor device cooling device 10, so that even if the degree of integration is extremely high, the surface mount IC 1 is excessively cooled. The expected performance expected in advance can be exhibited without causing a temperature rise.

According to the above-mentioned embodiment, the following effects can be obtained. (1) Since the temperature-sensitive deformable member 13 is deformed in response to a temperature increase due to heat generation of the surface-mounted IC 1 and a temperature decrease due to cooling of the cooling device 10, it is possible to ventilate the surface-mounted IC 1 and thus generate heat Not only can it be used effectively, but it is not necessary to consume power for cooling, and the IC 1 can be permanently cooled by forced air cooling.

(2) Since the ventilation is performed by the deformation of the temperature-sensitive deformable member 13, the structure of the ventilator can be simplified and the cooling device 1 can be used.
The height of the surface mount IC 1 including 0 can be made low.

(3) Since the group of temperature-sensitive deformable members 13 is constructed in the radiation fin structure, the surface-mounted IC 1 can effectively radiate heat naturally due to its shape and structure itself.

(4) The above (1), (2) and (3)
As a result, the surface-mounted IC 1 can be sufficiently cooled, so that even if the integration degree of the surface-mounted IC 1 is extremely high, the expected performance expected in advance can be achieved without causing an excessive temperature rise. Can be demonstrated.

FIG. 3 is a perspective view showing a surface mounting type IC cooling device according to a second embodiment of the present invention.

The second embodiment differs from the first embodiment in that
The temperature-sensitive deformable member 13A is configured so as to fan a fan in a horizontal plane parallel to the upper surface of the surface-mounted package 2. That is, the surface mount type IC cooling device 10A according to the second embodiment also includes the fan-shaped ventilator 11A configured in the radiation fin structure, and the surface mount type IC is provided.
1 is fixedly attached to the surface mount package 2. This ventilator 11A is a T-shaped steel-shaped base 12A having a length substantially equal to one end side of the surface mount type package 2.
Three temperature-sensitive deformable members 13A are arranged in parallel to each other on the vertical side of the base 12 and project in one direction in the horizontal direction. Then, the three temperature sensitive members 13
A is alternately deformed to the left and right to fan the fan. The bottom surface of the base 12A is adhered to the upper surface of the surface mount package 2 with an adhesive layer 14 interposed therebetween.

Also in the second embodiment, since the temperature-sensitive deformable members 13A are alternately deformed like a fan in accordance with heat generation and cooling of the surface-mounted IC 1, the same operational effects as those of the first embodiment are achieved. To be done.

4A and 4B show a surface mount type IC cooling device according to a third embodiment of the present invention. FIG. 4A is a front view and FIG. 4B is a plan view.

The third embodiment differs from the first embodiment in that
The point is that the ventilation device 11B having a shaft-flowing fan type structure that is rotationally driven by the temperature-sensitive deformable member 13B is provided. That is, the ventilation device 11B according to the third embodiment.
Includes a base 12B having a planar shape that is substantially the same as the planar shape of the surface mount package 2.
The lower surface thereof is adhered to the upper surface of the surface mount type package 2 via an adhesive layer 14. On the upper surface of the base 12B, a rotating shaft 15 is arranged at the center and is erected in a vertical direction, and a plurality of propeller-shaped blades 16 (four in the illustrated example) are provided on the upper end of the rotating shaft 15. They are arranged radially in a plane parallel to 12B and are fixed so as to rotate integrally. A ratchet gear 17 is arranged in the middle of the rotary shaft 15 in a plane parallel to the base 12B and fixed so as to rotate integrally.

On the other hand, the temperature-sensitive deformable member 13B according to the third embodiment has a ratchet pawl structure, and one end of the temperature-sensitive deformable member (hereinafter, also referred to as ratchet pawl) 13B has the base 12B. It is fixed to a support block 18 protruding from one end. The free end of the ratchet pawl 13B is meshed with the ratchet gear 17, and the ratchet gear 17 is rotationally driven by the deformation caused by the temperature change. The ratchet pawl 13B is configured such that its free end portion is alternately deformed to the left and right in accordance with the temperature change.

In the third embodiment, the surface mount type IC1
The ratchet pawl 13B is alternately deformed to the left and right due to the temperature change caused by heat generation and cooling of the ratchet gear 17 and the ratchet gear 17 is rotationally driven. The rotation of the ratchet gear 17 rotates the coaxial blades 16 to generate the wind 8, so that the surface mount package 2 and its surrounding atmosphere are forcibly and effectively cooled.

Although the invention made by the present inventor has been specifically described based on the embodiments, the present invention is not limited to the embodiments and various modifications can be made without departing from the scope of the invention. Needless to say.

For example, the temperature-sensitive deformable material forming the temperature-sensitive deformable member is not limited to shape memory alloys and bimetals, but any temperature-sensitive deformable member that deforms in response to temperature changes such as shape memory resin. Can be used.

The means for rotationally driving the fan by the temperature-sensitive deformable member is not limited to the ratchet mechanism, and a mechanism for converting the deformation of the temperature-sensitive deformable member into a rotational movement such as a spring mechanism. The entire structure can be used.

In the above description, the case where the invention made by the present inventor is mainly applied to the cooling device for the surface mounting type IC which is the field of application which is the background of the invention has been described, but the invention is not limited thereto. The natural air cooling can be applied to general cooling devices for semiconductor devices, which cannot use liquid cooling because of insufficient cooling.

[0037]

The effects obtained by the typical ones of the inventions disclosed in the present application will be briefly described as follows.

A temperature-sensitive deformable member made of a temperature-sensitive deformable material whose shape is changed by temperature change is attached to the semiconductor device so as to be sensitive to heat generated by the semiconductor device, and the temperature-sensitive deformable member is deformed by the deformation. Since a ventilator for ventilation is attached to the semiconductor device, the heat generated in the semiconductor device is effectively used to generate wind, so that power is not consumed for cooling and energy saving can be promoted. Not only that, the semiconductor device can be permanently forcibly cooled.

[Brief description of drawings]

1A and 1B are a front view and a front view, respectively, showing a surface mount type IC cooling device according to an embodiment of the present invention.

FIG. 2 is a perspective view thereof.

FIG. 3 is a perspective view showing a surface mount type IC cooling device according to a second embodiment of the present invention.

4A and 4B show a surface mount type IC cooling device according to a third embodiment of the present invention, in which FIG. 4A is a front view and FIG. 4B is a plan view.

[Explanation of sign]

1 ... Surface mount type IC (semiconductor device), 2 ... Surface mount type package, 3 ... Package body, 4 ... Outer leads, 5
... Printed wiring board, 6 ... Printed wiring board body, 7 ...
Heat, 8 ... Wind, 10, 10A ... Surface-mount type IC cooling device (semiconductor device cooling device), 11, 11A ... Fan-shaped aerator configured in a radiation fin structure, 12, 12A ... Base, 13 , 13A ... Fins (temperature sensitive deformation member), 1
4 ... Adhesive layer, 10B ... Surface mount type IC cooling device (semiconductor device cooling device), 11B ... Ventilation device configured in axial flow fan type structure, 12B ... Base, 13B ... Ratchet claw (temperature sensitive deformation member) ), 15 ... Rotating shaft, 16 ... Propeller-shaped blades, 17 ... Ratchet gear, 18 ... Support block.

Claims (3)

[Claims] 1. A temperature-sensitive deformable member using a temperature-sensitive deformable material whose shape is changed by temperature change is attached to a semiconductor device so as to be sensitive to heat generation of the semiconductor device, and the temperature-sensitive deformable member is A cooling device for a semiconductor device, wherein a ventilator for ventilating by deformation is attached to the semiconductor device. 2. The cooling device for a semiconductor device according to claim 1, wherein the fan is constituted by the temperature-sensitive deformable member itself. 3. The cooling device for a semiconductor device according to claim 1, wherein the fan is configured to be driven to rotate by deformation of the temperature-sensitive deformable member.