JPH0493054A - Flattened semiconductor device - Google Patents

Abstract

PURPOSE:To improve the cooling efficiency and miniaturize a cooler by providing a plurality of pipes communicating with the outside of an external enclosure in which a semiconductor pellet is contained, and sealing therein a refrigerant performing phase changes in boiling and condensation. CONSTITUTION:First, a pellet 10 is pressurized to a proper value owing to the deformation of a buffer part 16 of an external enclosure 13 once copper blocks 14, 14 undergo load in the arrow direction from the outside. Then, as power is supplied through the copper blocks 14, 14 the pellet 10 is heated, and produced heat is transmitted to the copper blocks 14, 14. Thereupon, a refrigerant 17 in contact with the surface outer periphery of the copper block 14 is boiled and evaporated. Evaporated vapor is sent from a vapor paper 18 of the external enclosure 13 to a heat exchanger, and is liquefied, and is thereafter returned from a return pipe 19. More specifically, the pellet 10 is directly cooled by the cooling system. Accordingly, thermal resistance is reduced compared with a prior art system where heat is once transmitted to the outside of the external enclosure, and further since a cooler is integrated, the entire can be miniaturized and made light-weight.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Field of Application) The present invention relates to a flat semiconductor device with improved cooling efficiency and miniaturization.

(Prior Art) Conventionally, heat dissipation from large-capacity flat semiconductor devices has been achieved by using a heat pipe 3 using fins 2 pressed against both sides of the semiconductor device 1 as heat receiving parts, as shown in FIG. As shown in Fig. 8, the airtight container 4 and the radiator 5 are connected by the steam pipe 6 and the return pipe 7, and the refrigerant 8 and the fins 2 are inserted into the airtight container 4 from both sides.
There is a boiling cooling method that accommodates the flat semiconductor element 1 which is pressure-welded.However, the boiling cooling method is superior in terms of cooling efficiency and has been widely used.

(Problems to be Solved by the Invention) However, the boiling cooling method described above has the following drawbacks.

(1) There is resistance to heat conduction inside a semiconductor element, and in the case of a large capacity, there is a large internal temperature gradient, and there is a cooling limit.

(2) Due to the above item (1), it is necessary to lower the temperature of the refrigerant, which increases the size of the radiator.

(3) The boiling heat transfer coefficient decreases due to the above item (2).

(4) Since the cooling section becomes large, high-pressure refrigerant cannot be used due to the structure of the pressure vessel.

(5) Due to the above drawbacks, even if the cooler is made larger,
It is not possible to use 100% of the capacity of a large-capacity semiconductor element.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a flat semiconductor device that eliminates the following two drawbacks, performs cooling efficiently, makes full use of the capabilities of a large capacity semiconductor device, and has a miniaturized cooler. be.

[Structure of the Invention] (Means for Solving the Problems) The present invention provides a flat semiconductor device in which a semiconductor pellet is housed in a sealed envelope and is pressure-contacted from the outside. A refrigerant that undergoes a phase change of boiling and condensation is sealed inside.

(Function) When the semiconductor pellet is energized through the components of the envelope, it generates heat, and this heat is transferred to the components of the envelope and boils the refrigerant sealed inside the envelope. let The generated steam is sent to a heat exchanger via a pipe communicating with the outside and is liquefied. This liquefied refrigerant is returned to the envelope via another pipe. This series of actions directly cools the semiconductor pellet. Therefore, the thermal resistance is lower than the conventional system that transfers heat to the outside of the envelope and then cools it.
Furthermore, although the cooler is integrated, the overall size and weight can be reduced.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. FIG. 1 is a front view showing one embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along the line AA in FIG.

As shown in FIGS. 1 and 2, the surface of the pellet 10 is covered with a buffer plate 11 made of a metal material (for example, W, Mo, Cu) to increase refrigerant resistance, and the end portion An insulating block 12 is provided to strengthen the insulation between the at and the cathode, and the copper blocks 14 and 14 forming the envelope 13 are pressed down from both sides.

The envelope 13 is formed into an annular shape with a pair of copper blocks 14 and 14 which are disk-shaped and press down the pellet 10 from both sides, an insulating part 15 whose inner diameter is larger than the outer diameter of the pellet 10, and a thin stainless steel block. The insulation part 15 is airtightly joined to each side surface of the insulating part 15 at a bent part provided on the outer periphery, and the copper block 14 is hermetically joined to the corner part provided in the center. A groove lea is provided,
A pair of buffer parts 1B, 1 arranged in a facing state
[f], forming a space inside, and containing a low boiling point refrigerant (
For example, 3M Co., Ltd.'s product name Fluorinert) 17 is enclosed.

On the other hand, the insulating part 15 is provided with a heat exchanger (not shown) that transfers steam when the refrigerant 17 boils to an upper position in the use state.
A return pipe 19 for the refrigerant 17 liquefied in the heat exchanger is connected to the steam pipe 18 leading to the refrigerant 17 at the opposite position.

With the above configuration, the inner side of the copper block 14 acts as a cooling fin, and the outer side is used for conduction and pressure welding, and the buffer part 16 is configured so that when the copper block 14 is pressurized by the annular groove lea. Also, excessive stress will not be generated.

Next, the operation of the embodiment configured as above will be explained. First, the pellet 10 is inserted into the copper block 14.1 from the outside.
4 receives a load in the direction of the arrow in FIG. 2, the buffer portion 16 of the envelope 13 deforms and is pressed to an appropriate value. When electricity is then passed through the copper block 14.14, the pellet 10 generates heat, which is conducted to the copper block 14.14. Therefore, the refrigerant 17 in contact with the surface (outer periphery) of the copper block 14 boils and vaporizes. The vaporized steam is
The steam is sent from the steam pipe 18 of the envelope 13 to a heat exchanger (provided in the upper part, but not shown), and is returned from the return pipe 19 after being liquefied. That is, the pellets 10 are directly cooled by this cooling system.

Note that the present invention is not limited to the above-described embodiment (hereinafter referred to as the first embodiment), and can be implemented in various modifications. FIG. 3 is a cross-sectional view showing the main parts of another embodiment of the present invention (hereinafter referred to as the second embodiment), and FIG.
It is an A sectional view. This second embodiment consists of a copper block 14
Through holes 20 are provided along the vertical direction in the copper block 14, thereby increasing the surface area of the copper block 14 and making it possible to further improve the cooling capacity compared to the first embodiment. Further, FIG. 5 shows a further different embodiment (hereinafter referred to as the third embodiment) of the present invention.
FIG.

In this third embodiment, the outer periphery of the copper block 14 (however,
Folds 21 are provided in the copper block 14 (excluding the part where the buffer section 16 is bonded), thereby increasing the surface area of the copper block 14 and further improving the cooling capacity compared to the first embodiment, similar to the second embodiment. can do. FIG. 6 shows another embodiment (hereinafter referred to as the fourth embodiment) of the present invention.
FIG. In this fourth embodiment, two insulating parts 22 are used, and the inner periphery is directly connected to the copper block 14, with the outer and inner diameters being symbiotic than the insulating parts 15 of the above-mentioned embodiments.
An annular groove 23a is provided in the buffer part 23 at a position near the outer periphery, and a steam pipe 18 and a return pipe (not shown) are connected to the bent part of the outer periphery. The same effect can be obtained.

[Effects of the Invention] As explained above, according to the present invention, a flat semiconductor element having the following effects can be provided.

(1) Since the thermal resistance inside the semiconductor element is small, the cooling effect is large.

(2) There is no contact thermal resistance between the semiconductor element and the cooling fins as in the conventional case.

(3) Good responsiveness as the pellets are directly boiled and cooled;
Strong against peak loss.

(4) Since the cooler is integrated, the configuration is simple.

(5) The internal volume is small, the amount of refrigerant is small, and it does not become a pressure vessel. In addition, it is resistant to internal pressure because it is an external pressure welding type.

(6) Smaller size and lighter weight.

(7) Cooling capacity can be further improved by cooling the envelope from the outside.

[Brief explanation of drawings]

FIG. 1 is a front view showing one embodiment of the present invention, and FIG. 2 is a front view showing one embodiment of the present invention.
3 is a sectional view showing the main parts of another embodiment of the present invention, FIG. 4 is a sectional view taken along A-A of FIG. 3, and FIG. 5 is a further different embodiment of the present invention. FIG. 6 is a sectional view showing the main part of another embodiment of the present invention. FIG. 7 is a sectional view showing the main part of another embodiment of the present invention. FIG. FIG. 8 is an explanatory diagram showing a state in which a conventional flat semiconductor element is boiled and cooled by a cooling medium. 10... Semiconductor pellet, 13... Envelope, 1
4... Copper block, 16... Buffer section, 18... Steam pipe, 15... Insulating section, 17... Refrigerant, 19... Return pipe.

Claims (1)

[Claims] In a flat semiconductor device in which semiconductor pellets are housed in a sealed envelope and pressed against the outside, the envelope is provided with a plurality of pipes communicating with the outside, and a refrigerant that undergoes a phase change of boiling and condensation is sealed inside. A flat semiconductor device characterized by: