JP2757893B2 - Flat semiconductor device - Google Patents

Description

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

(Prior Art) Conventionally, for heat radiation of a large-capacity flat semiconductor element, as shown in FIG. 7, a method using a heat pipe 3 having a fin 2 pressed from both sides of a semiconductor element 1 as a heat receiving portion, As shown in FIG. 8, the closed vessel 4 and the condenser 5 are connected to the steam pipe 6 and the return pipe 7.
There is a boiling cooling method in which the refrigerant 8 and the fins 2 are pressed from both sides into the closed container 4 to accommodate the flat semiconductor element 1 in the closed container 4, but the boiling cooling method is excellent in terms of cooling efficiency.
Many were adopted.

This boiling cooling method is described in, for example, a microfilm disclosed in Japanese Utility Model Application No. 53-149271 (Japanese Utility Model Application Publication No. Sho 55-65864). In FIG. 4 of the microfilm,
The configuration diagram of the boiling cooling tank of the flat type element is shown,
A flat element 15 and cooling fins 18 attached to both sides thereof are housed in a tank 31, and a refrigerant 16 is sealed therein. tank
Reference numeral 31 is connected to the condensing section 12 by a vapor pipe 13 and a liquid pipe 14. With such a configuration, the heat generated by the flat element 15 is transmitted to the cooling fins 18, cooled by exchanging heat with the refrigerant 16 inside the tank 31, and the refrigerant 16 that has received heat boils and rises up the steam pipe 13. Then, the heat is dissipated and condensed to the atmosphere in the condensing section 12 and returned to the tank 31 through the liquid pipe 14 again.

(Problems to be Solved by the Invention) However, the above-mentioned boiling cooling system has the following problems.

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

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

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

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

(5) Due to the above problems, even if the cooler is enlarged, 100% of the capacity of the large-capacity semiconductor element cannot be used.

Therefore, the present invention has been made in order to solve the above-described problems, and a refrigerant is directly sealed in the inside of a flat semiconductor element, and a constituent member of an envelope, which is one part of the flat semiconductor element, is provided. It is an object of the present invention to provide a flat semiconductor device which can increase the cooling efficiency by using the same function as a cooling fin and can make full use of the capacity of a large-capacity semiconductor device.

[Constitution of the Invention] (Means for Solving the Problems) In order to achieve the above-mentioned object, the present invention provides an envelope accommodating semiconductor pellets, and a pipe provided in the envelope and communicating with the outside. And sealed inside the envelope,
And a refrigerant that changes the phase of condensation.

(Operation) According to the above-described configuration, the semiconductor pellet generates heat when energized through the constituent members of the envelope, and this heat is transmitted to the constituent members of the envelope and sealed inside the envelope. Bring the refrigerant to a boil. The generated vapor is sent to a separately provided heat exchanger via a pipe communicating with the outside to be liquefied, and the liquefied refrigerant is returned to the envelope via a pipe communicating with the outside. The semiconductor pellet is directly cooled by this series of operations.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a front view of a flat type semiconductor device showing one embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG.

The semiconductor pellet 10 has a metal material (for example, W,
It is covered with a buffer plate 11 made of Mo, Cu) and has an insulating block 12 at an end. The buffer plate 11 enhances refrigerant resistance, and the insulating block 12 enhances insulation between the anode and the cathode. And the semiconductor pellet 10 thus configured is a copper block 14, 1 constituting the envelope 13.
4 is pressed from both sides.

The envelope 13 has a pair of copper blocks 14, 14, which are disc-shaped and press the semiconductor pellet 10 from both sides, and an insulating portion 15, which is formed in a ring shape of ceramic and has an inner diameter larger than the outer shape of the semiconductor pellet 10, It is formed of a thin stainless steel material, and is air-tightly joined to each side surface of the insulating portion 15 at a bent portion provided on the outer periphery, and air-tightly joined to the copper block 14 at an opening provided at the center, and close to the outer periphery. An annular groove 16a is provided at the position,
It is composed of a pair of buffer units 16 and 16 arranged opposite to each other, forms a space inside, and encloses a low-boiling-point refrigerant (for example, Fluorinert (trade name of Sumitomo 3M)) 17.

On the other hand, the insulating section 15 has a steam pipe 18 for guiding steam to a heat exchanger (not shown) which is a condenser when the refrigerant 17 boils to a position on the upper side in use, and a heat exchanger 18 for heat exchange at an opposite position. The return pipe 19 of the refrigerant 17 liquefied by the vessel is connected.

With the above configuration, the coolant 17 can be directly enclosed in the semiconductor element, the inside of the copper block 14 acts as a cooling fin, the outside is used for conduction and pressure welding, and the buffer section 16 has an annular groove 16a. Therefore, even when the copper block 14 is pressed, excessive stress is not generated.

Next, the operation of the embodiment configured as described above will be described. First, the semiconductor pellet 10 is externally supplied with the copper block 1.
When the loads 4 and 14 receive the load in the direction of the arrow in FIG. 2, they are pressed and pressed to an appropriate value by deformation of the buffer section 16 of the envelope 13. Next, when electricity is supplied through the copper blocks 14, 14, the semiconductor pellet 10 generates heat, and this heat is transmitted to the copper blocks 14, 14. Then, the refrigerant 17 in contact with the surface (outer circumference) of the copper block 14 boils and evaporates. The vaporized vapor is supplied to the envelope 13
From the steam pipe 18 to a heat exchanger (provided at the top but not shown), liquefied, and returned from the return pipe 19. That is,
The semiconductor pellet 10 can be directly cooled by this cooling system.

As described above, in the present embodiment, the copper block 14 constituting a part of the semiconductor element is used as a cooling fin, and the semiconductor element itself is configured so that the refrigerant is directly sealed inside the semiconductor element. Temperature difference (heat resistance)
And the cooling efficiency can be greatly improved. Further, since the cooling fin is a part of the semiconductor element, the contact thermal resistance between the semiconductor element and the cooling fin can be eliminated, and the configuration can be simplified because the cooler is integrated. Since the resistance to heat conduction can be eliminated in this way, the internal refrigerant temperature can be set higher on the condenser (heat exchanger) side, so that the temperature difference from the outside air is large and the performance of the condenser is improved, resulting in a smaller and lighter body. Is possible. In addition, since the semiconductor pellet 10 is directly cooled by boiling, the response is good, and the temperature rise inside the semiconductor element can be reduced.
A large margin can be taken with respect to the allowable temperature, the peak cross can be strengthened and the reliability can be improved. Furthermore, since the internal volume of the semiconductor element is small and the amount of the refrigerant is small, the semiconductor element is not a pressure vessel. In addition, if the envelope 13 is cooled from the outside, the cooling efficiency can be further improved.

The present invention is not limited to the above-described embodiment (hereinafter, referred to as a first embodiment), and can be variously modified. FIG. 3 is a sectional view showing a main part of another embodiment (hereinafter, referred to as a second embodiment) of the present invention, and FIG.
It is A sectional drawing. In the second embodiment, a through-hole 20 is provided in the copper block 14 along the up-down direction, so that the surface area of the copper block 14 can be increased. Can be improved. FIG. 5 is a sectional view showing a main part of still another embodiment (hereinafter, referred to as a third embodiment) of the present invention. In the third embodiment, the folds 21 are provided on the outer periphery of the copper block 14 (except for the portion where the buffer section 16 is joined), so that the surface area of the copper block 14 can be increased. Like the second embodiment, the cooling capacity can be improved as compared with the first embodiment. FIG. 6 is a sectional view showing a main part of still another embodiment (hereinafter, referred to as a fourth embodiment) of the present invention. This fourth embodiment is:
The outer periphery and the inner diameter are smaller than the insulating portion 15 of each of the above embodiments using two insulating portions 22. The inner periphery is directly airtightly joined to the copper block 14, and the buffer portion 23 has an annular groove near the outer periphery. 23a is provided, and the steam pipe 18 and the return pipe (not shown) are connected to the bent portion on the outer periphery, so that the same effect as in the first embodiment can be obtained.

[Effects of the Invention] As described above, according to the present invention, a refrigerant is directly enclosed in a flat semiconductor device, and a cooling fin is used as a component of an envelope which is a component of the flat semiconductor device. By increasing the cooling efficiency by using the same function as
It is possible to provide a flat semiconductor device capable of fully utilizing the capability of a large-capacity semiconductor device.

[Brief description of the drawings]

FIG. 1 is a front view of a flat type semiconductor device showing one embodiment of the present invention, FIG. 2 is a sectional view taken along line AA of FIG. 1, and FIG. FIG. 4 is a sectional view showing a part.
FIG. 5 is a cross-sectional view taken along the line AA of FIG. 5, FIG. 5 is a cross-sectional view showing a main part of still another embodiment of the present invention, and FIG. FIG. 7 is a diagram showing a conventional cooling structure using a heat pipe, and FIG. 8 is a diagram showing a conventional cooling structure using a boiling cooling method. 10 ... semiconductor pellet, 13 ... envelope, 14 ... copper block, 15 ... insulating part, 16 ... buffer part, 17 ... refrigerant, 18 ... steam pipe, 19 ... return pipe.

Claims (1)

(57) [Claims] 1. An envelope accommodating semiconductor pellets, a pipe provided in the envelope and communicating with the outside, and a refrigerant sealed in the envelope and performing a phase change of boiling and condensation. A flat semiconductor device that is composed.