JPH1197597A - Cooling apparatus for semiconductor circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling apparatus for cooling semiconductor circuit which efficiently removes heat from electronic components such as transistors or the like, by passing cooling air through a porous honeycomb-structured material body. SOLUTION: A semiconductor circuit to be cooled consists of an electrically non-conductive ceramic substrate 1 on which electronic components including transistors 10 and circuit components 11 are mounted. The cooling apparatus has a porous honeycomb-structured material body 3 made of a ceramic material of high thermal conductivity, which is bonded onto the backside of the substrate 1 with a resin material 15 to which metallic powder of high thermal conductivity has been mixed. The honeycomb-structured material body 3 is covered by a casing 2 except at an inlet 6 and an outlet 7 for the cooling air. A fun 14, which is driven by a small motor 4, produces a cooling air flow that passes through the porous honeycomb-structured material body 3 from the inlet 6 to the outlet 7.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor circuit cooling apparatus for cooling electronic components including transistors and circuit elements mounted on a substrate through the substrate.

[0002]

2. Description of the Related Art Conventionally, in a semiconductor circuit, a large-sized thyristor or a power transistor is generally used in a high-output inverter for controlling a large current to produce a sine curve or the like. In such a semiconductor circuit, heat loss in the thyristor and the transistor is large, and the function of electronic components such as the thyristor and the transistor often deteriorates due to heat generation during operation. Therefore, various cooling devices for cooling the semiconductor circuit in order to prevent heat generation during operation in the semiconductor circuit are known. Inverters convert DC to AC or convert voltage and frequency to adjust the speed and the like. For example, the frequency can be converted to 10 to 600 cycles.
The number of rotations can be converted.

[0003]

However, when the frequency is switched by the operation of the inverter, heat is generated, and the heat deteriorates the characteristics of the semiconductor. Therefore, the semiconductor circuit is provided with a cooling device. Conventional cooling devices
It has a fin-type structure with a large fan and extremely low cooling efficiency for cooling semiconductor circuits, and has a large structure. In a small device such as a control device including a semiconductor circuit, a large-sized cooling fin made of aluminum cannot be used, and when the cooling fin is used, the control device cannot be configured in a small size. Therefore, at present, there is a demand for a cooling device having a good cooling performance and a compact structure.

Incidentally, among ceramics, silicon carbide (SiC) and aluminum nitride (AlN) are known to have high thermal conductivity. A porous honeycomb member can be manufactured using these ceramic materials.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to form a porous honeycomb member by forming ceramics having a high thermal conductivity, such as SiC or AlN, on the porous honeycomb member and passing cooling air through the porous honeycomb member. The cooling device itself is made compact by the porous honeycomb member, and electronic components such as a power transistor, a thyristor, and a printed circuit fixed to the porous honeycomb member are used. An object of the present invention is to provide a cooling device for a semiconductor circuit that can be air-cooled by cooling air passing through a porous honeycomb member and can prevent deterioration of various electronic components due to heat.

According to the present invention, in a semiconductor circuit having a substrate made of non-conductive ceramics on which electronic components including at least transistors are mounted, the semiconductor circuit is fixed to a back surface opposite to a mounting surface of the substrate on which the electronic components are mounted. A porous honeycomb member made of ceramics having a high thermal conductivity and having an air passage, attached to the substrate via the provided resin member, and the porous honeycomb member leaving an inlet and an outlet for air flowing through the porous honeycomb member. And a fan for forming an air flow for cooling from the inlet to the outlet in the porous honeycomb member, and a small motor for driving the fan. Related to the device.

The resin member used for attaching the porous honeycomb member to the substrate contains a material powder having a high thermal conductivity. The material powder is, for example, metal powder, AlN, or SiC powder. The thermal conductivity of the resin member is increased, and the resin member enters the pores of the honeycomb of the substrate and the porous honeycomb member and is strongly joined to both.

[0008] The porous honeycomb member is formed in a multi-stage structure, and its ends are alternately formed as closed ends. That is, in the porous honeycomb member, one end of the inlet portion and the outlet portion of the honeycomb structure is formed at the closed end and the other end is formed at the open end, and the inlet portion, the outlet portion, Are alternately formed with a closed end and an open end. Therefore, even if fine particles are contained in the air flowing into the porous carbon member, the surrounding environment is not polluted by the air collected by the porous carbon member and discharged from the fan.

[0009] The porous honeycomb member is formed of SiC or AlN ceramics having high thermal conductivity, and heat from the substrate is transmitted well. Therefore, the heat of the substrate quickly moves to the porous carbon member, where
It is quickly carried away by the airflow. Since the porous honeycomb member can be configured to have a large area even if the porous honeycomb member is thin, the amount of cooling air passed through the porous honeycomb member can be reduced, the motor for driving the fan can be reduced in size, and the cooling device itself can be configured. Can be simply and space-saving.

An air purifier is provided upstream of the porous honeycomb member, and the fan provided downstream of the porous honeycomb member is a suction fan. Therefore, since the air flowing through the porous carbon member is cleaned by the air purifier, the durability of the porous carbon member can be improved without contaminating the porous carbon member with fine particles or the like.

The small motor is operated so that the speed of the fan can be adjusted according to the operation state of the electronic component. Therefore, even if high heat is generated in accordance with the operation state of the electronic component such as a power transistor, the speed of the fan can be increased according to the temperature rise, and the cooling effect can be increased.

Further, the porous honeycomb member has an open pore formed in the porous structure of 50 to 200 μm.
m. Therefore, the air can flow smoothly without the porous carbon member becoming the resistance of the air flow, and the cooling effect can be improved.

In the porous honeycomb member, the thickness of a wall forming the porous structure is 0.5 to 1 mm. Therefore, heat from the substrate can be efficiently received by the porous structure, and the heat can be carried out to the outside by an air flow.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a semiconductor circuit cooling device according to the present invention will be described below with reference to the drawings. FIG.
FIG. 2 is a schematic sectional view showing an embodiment of the semiconductor circuit cooling device according to the present invention, FIG. 2 is a side view of FIG. 1, and FIG. 3 flows through a part of the porous carbon member in the semiconductor circuit cooling device of FIG. It is explanatory drawing which shows an airflow.

The cooling device for a semiconductor circuit according to the present invention comprises:
As shown in FIG. 1, a semiconductor circuit provided with a substrate 1 made of non-conductive ceramics to which a transistor 10 such as a power transistor, a thyristor 18 and an electronic component including a circuit element 11 such as an electronic component and a printed circuit are attached. A cooling device including a porous honeycomb member 3 is provided. The power transistor is designed for high power and large current, and is applied to a control device. However, the power transistor generates heat by frequent switching operation or the like. The cooling device for a semiconductor circuit mainly includes a resin member 1 fixed to a substrate 1 on which electronic components that generate heat by operation are attached.
5, a porous honeycomb member 3 attached to the substrate 1 via a resin member 15, a casing 2 covering the porous honeycomb member 3, a fan 14 for forming an air flow for cooling in the porous honeycomb member 3, and a fan. It is composed of a small motor 4 for driving the motor 14.

In this cooling device for a semiconductor circuit, electronic components are mounted on a mounting surface 16 on one side of the substrate 1, and a resin member 15 is tightly fixed to a back surface 17 opposite to the mounting surface 16. The resin member 15 functions as a kind of adhesive formed from a resin material mixed with a metal powder having a high thermal conductivity, AlN, and SiC powder. The porous honeycomb member 3 is made of ceramics having a high thermal conductivity, and includes a wall 8 having an open pore of a porous structure and an air passage 9 formed by the wall 8. The casing 2 is configured to cover the porous honeycomb member 3 except for an inlet 6 and an outlet 7 of the air flowing through the porous honeycomb member 3. The fan 14 is provided with the porous honeycomb member 3.
It is driven by a small motor 4 so as to form an air flow for cooling from an inlet 6 to an outlet 7 therein.

In this semiconductor circuit cooling device, the porous honeycomb member 3 is formed in a multi-stage structure.
The porous honeycomb member 3 is made of SiC, A having a large thermal conductivity.
It is formed from 1N ceramics. Further, in the porous honeycomb member 3, one end of the inlet and the outlet of the honeycomb structure is formed at the closed end 12, and the other end is formed at the open end 13. Further, in the adjacent inlet portion of the porous honeycomb member 3, closed end portions 12 and open end portions 13 are formed alternately. Therefore, the porous honeycomb member 3 is configured as a filter capable of collecting a kind of fine particles.

At the inlet 6 of the porous honeycomb member 3, an air purifier 5 is provided, and at the outlet 7 of the porous honeycomb member 3, a fan 14 composed of a suction fan is provided. The small motor 4 is operated so that the speed of the fan 4 can be adjusted according to the operation state of the electronic components.

The porous honeycomb member 3 has an open pore size of 50 to 2 on the wall 8 of the porous structure.
It is formed to be 00 μm. In the porous honeycomb member 3, the wall 8 forming the porous structure has a thickness of 0.5 to 1 mm.

Since the cooling device for a semiconductor circuit is configured as described above, the electronic components generate heat in accordance with the operation state of the electronic components such as transistors, but the heat is transmitted from the substrate 1 through the resin member 15. The power is transmitted to the porous honeycomb member 3. Then, when the small motor 4 is driven and the fan 14 rotates, external air is sucked from the inlet 6 through the porous honeycomb member 3, and the external air becomes cooling air and passes through the air purifier 5 to form the porous honeycomb. The porous honeycomb member 3 flows into the porous honeycomb member 3 from the open pores and the open end 13 of the closed end portion 12 of the member 3, takes out the heat transmitted to the porous honeycomb member 3, and flows out from the outlet 7 to remove the porous honeycomb member 3. Dissipate heat. Since the porous honeycomb member 3 itself has an extremely large air contact area, heat is radiated from the porous honeycomb member 3 actively, so that it is not necessary to increase the air volume of the air passing through the porous honeycomb member 3 so much. Therefore, the motor 4 itself can be formed in a small size, and the cooling device itself can be configured in a simple space-saving structure.

[0021]

The semiconductor circuit cooling device according to the present invention is constructed as described above, so that only a fan and a porous honeycomb member are mounted on a substrate on which electronic components including transistors and circuit elements are mounted. The device itself can be made compact, and the motor itself can be made small. Therefore, the cooling device for a semiconductor circuit can be applied to, for example, a control device for a generator incorporated in a cogeneration system or a control device for a hybrid vehicle using a motor.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an embodiment of a cooling device for a semiconductor circuit according to the present invention.

FIG. 2 is a side view of the semiconductor circuit cooling device of FIG. 1;

3 is an enlarged cross-sectional view of a portion indicated by reference numeral A of the cooling device for a semiconductor circuit of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Substrate 2 Casing 3 Porous honeycomb member 4 Small motor 5 Air cleaner 6 Inlet 7 Exit 8 Wall 9 Air passage 10 Transistor 11 Circuit element 12 Closed end 13 Open end 14 Fan 15 Resin member 16 Mounting surface 17 Back surface 18 Thyristor

Claims (10)

[Claims] 1. A semiconductor circuit comprising a substrate made of non-conductive ceramics on which an electronic component including at least a transistor is mounted, the semiconductor circuit being fixed to a back surface opposite to a mounting surface of the substrate on which the electronic component is mounted. A porous honeycomb member which is attached to the substrate via a resin member and has an air passage and is made of ceramic having a high thermal conductivity, and covers the porous honeycomb member except for an inlet and an outlet of air flowing through the porous honeycomb member. A cooling device for a semiconductor circuit, comprising: a casing; a fan for forming an air flow for cooling from the inlet to the outlet in the porous honeycomb member; and a small motor for driving the fan. 2. The cooling device for a semiconductor circuit according to claim 1, wherein said porous honeycomb member is formed in a multi-stage structure. 3. The semiconductor circuit cooling device according to claim 1, wherein a material powder having a high thermal conductivity is mixed in said resin member. 4. The semiconductor circuit cooling device according to claim 3, wherein the material powder mixed in the resin member is a metal powder, AlN or SiC powder. 5. The porous honeycomb member, wherein one end of an inlet and an outlet of the honeycomb structure is formed at a closed end and the other end is formed at an open end. 2. The cooling device for a semiconductor circuit according to claim 1, wherein ends adjacent to the outlet are alternately formed as a closed end and an open end. 6. The cooling device for a semiconductor circuit according to claim 1, wherein said porous honeycomb member is made of ceramics of SiC or AlN having high thermal conductivity. 7. An air purifier is provided upstream of the porous honeycomb member, and the fan provided downstream of the porous honeycomb member is a suction fan. Item 2. A cooling device for a semiconductor circuit according to item 1. 8. The semiconductor circuit cooling device according to claim 1, wherein the small motor is operated such that the speed of the fan can be adjusted according to an operation state of the electronic component. 9. The cooling device for a semiconductor circuit according to claim 1, wherein the porous honeycomb member has an open pore formed in the porous structure of 50 to 200 μm. 10. The semiconductor circuit according to claim 1, wherein the thickness of a wall forming the porous structure of the porous honeycomb member is 0.5 to 1 mm. Cooling system.