JP2628733B2 - Electric insulation type heat pipe cooler - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improved electrically insulated heat pipe cooler used for cooling semiconductor devices and electronic devices.

[Prior art and its problems] A heat pipe type cooler is used for cooling a heat generating portion of a semiconductor element or an electronic device. In this heat pipe type cooler, a block (heat sink) for collecting or dispersing heat is provided with a hole, and a heat pipe is inserted. This portion is used as an evaporator, a fin is provided in a condenser, and a radiator is provided. The heat of the section is radiated by the radiating section. And for the heat flux conversion of the evaporation part and the condensation part of the heat pipe,
The length ratio of the heat transfer tube is changed, and the diameters of the evaporator and the condenser are changed. In addition, in recent years, the processing technology of thyristors and the like has been improved, and the capacity of semiconductor elements has been increased. In environments where safety is important, such as in the case of railway vehicles, it is desirable to electrically isolate places where there is a possibility of contact,
The one provided with an electric insulating part between the evaporating part and the condensing part is used. For example, as shown in FIG. 2, one or two or more tubular holes are provided in a block (3) having good heat conductivity such as copper, and these holes are used as an evaporating section (1). A fin (2) is provided to form a condenser tube (5), and the evaporator and the condenser are connected by an insulator (7) such as alumina or ceramic with an intermediate (6) or (6 '). Insulating CFC
A working fluid (4) such as R113 is sealed to form an insulated heat pipe cooler. In the above-described conventional example, the block (3) itself is used as the evaporator (1) of the heat pipe. However, it goes without saying that an independent heat pipe may be inserted into a hole provided in the block.

[Problems to be solved by the invention]

If it is necessary to increase the amount of heat radiation, many holes are provided in the block to form an evaporator, or many heat pipes are inserted into those holes. However, the diameter of the electrical insulator is larger than that of the heat pipe in order to secure the required creepage distance for the withstand voltage and to withstand the internal pressure. Therefore, there is a problem that the amount of heat radiation is limited. In addition, in order to increase the amount of heat radiation, it is necessary to increase the number of heat pipes, that is, to increase the size of the block, which causes a problem that the manufacturing cost of the cooler increases.

The present invention has been made in view of the above points, and its purpose is to obtain high heat dissipation performance,
Another object of the present invention is to provide an electrically insulated heat pipe cooler whose production cost is lower than that of the conventional heat pipe cooler.

[Means and actions for solving the problem]

According to the present invention, in order to achieve the above-mentioned object, the evaporating unit and the condensing unit include a plurality of heat pipes connected via an electrical insulator, and the evaporating unit includes a tubular member provided in a heat-conductive block. Hole, or a tube inserted into the hole, the condenser is a tube provided with fins in an electrically insulated heat pipe cooler, wherein a plurality of evaporators and condensers form an integral electric insulator. An electrically insulated heat pipe cooler characterized in that the heat pipe cooler is connected to the heat pipe cooler.

In the above structure, it is considered that the electric insulator has sufficient strength against the internal pressure of the heat pipe, and that the semiconductor element or the electronic device, which is the object to be cooled, mounted on the heat conductive block has a potential. Then, it is necessary to satisfy two conditions of having a creepage distance necessary for withstand voltage.

Conventionally, as shown in FIG. 2, an electric insulator (7) is provided for each heat pipe, and its surface is corrugated to secure a creepage distance. Therefore, a certain interval is required between the heat pipes, and the arrangement density of the heat pipes is limited.

On the other hand, according to the present invention, since a plurality of evaporating sections and a plurality of condensing sections are respectively connected to the integral electric insulator and a plurality of heat pipes are formed, the creepage distance may be secured by the integral electric insulator. The distance between the heat pipes is determined only by the workability of the electric insulator and the strength against internal pressure, so that the arrangement density of the heat pipes and the heat radiation performance can be improved as compared with the prior art.

〔Example〕

The present invention will be described below based on embodiments shown in the drawings.

FIG. 1 is a sectional view of one embodiment according to the present invention,
Three holes having an inner diameter of 14 mmφ and a depth of 90 mm were formed in a copper block (3) having a width of 85 mm, a height of 100 mm and a thickness of 25 mm at a pitch of 22 mm, and this was used as an evaporation section (1). On the other hand, inner diameter 14mmφ, thickness 0.9m
A large number of fins (2) were provided on three copper tubes having a length of 250 mm and a length of 250 mm to form a condenser tube (5). Between the condenser tube (5) and the copper block (3), a hole made of alumina having an inner diameter of 14 mm was formed at a pitch of 22 mm.
An electrical insulator (8) having three mm is brazed with silver brazing through intermediates (6) and (6 ') made of a sealing material of Fe-Ni alloy, and Freon R113 is supplied from a nozzle (9). Was injected and sealed to obtain an electrically insulated heat pipe cooler. Two coolers are used as a pair, and the heat dissipation between copper blocks is about 1k.
A heat dissipation experiment was conducted with one thyristor w. Similarly, when a cooler was manufactured using a conventional type of electrical insulator, the hole pitch could not be reduced by 30 mm or more. In this way, the size can be reduced as compared with the case where the electric insulator is interposed in each conventional heat pipe,
Although the same performance was obtained, the manufacturing cost could be reduced by nearly 20%. Further, with respect to a cooler having the same dimensions using four heat pipes, the installation density of the heat pipes can be increased, so that the performance can be improved by 10% or more.

In the present embodiment, the cross sections of the evaporating section and the condensing section are circular with the same inner diameter, but they may have different shapes with different sizes.

〔The invention's effect〕

As described above, according to the present invention, since the plurality of evaporating sections and the condensing sections are connected via the integral electric insulator, the heat radiation performance can be improved and the manufacturing cost can be reduced. Has excellent effects.

[Brief description of the drawings]

FIG. 1 is a sectional view of an electrically insulated heat pipe cooler according to one embodiment of the present invention, and FIG. 2 is a sectional view of a conventional electrically insulated heat pipe cooler. 1 ... Evaporation section, 2 ... Fin, 3 ... Block, 4 ...
Hydraulic fluid, 5: Condenser tube, 6, 6 '... Intermediate, 7, 8 ...
Insulator, 9 ... Nozzle.

Claims (1)

(57) [Claims] 1. An evaporating section and a condensing section each comprising a plurality of heat pipes connected via an electrical insulator, wherein the evaporating section has a tubular hole provided in a heat conductive block, or
A plurality of evaporating units and a condensing unit connected via an integral electric insulator in an electric insulation type heat pipe cooler, wherein the condensing unit is a tube provided with fins. An electrically insulated heat pipe cooler.