JP2006269629A - Heat pipe type cooler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat pipe type cooler for securing desired cooling performance when the width of a use environment condition such as ambient temperature is wide. <P>SOLUTION: A heat pipe type cooler 1 is configured by attaching a plurality of heat pipes 3a and 3b in which cooling media are sealed on a heat receiving block 2. The plurality of heat pipes 3a and 3b are configured of two types of heat pipes 3a and 3b in which cooling media with different operation regions such as demineralized water and an antifreeze solution are sealed. Those two types of heat pipes 3a and 3b may be alternately arranged side by side, or the plurality of sets of the two types of heat pipes 3a and 3b which are adhered to each other may be prepared, and arranged at intervals between each set. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a heat pipe type cooler that cools devices such as semiconductor elements.

  In recent years, in power converters, an increase in heat generation loss has become a problem as the capacity and speed of semiconductor elements increase. For this reason, it is an important issue to improve the cooling efficiency of the cooler for power semiconductor elements and to avoid the enlargement of the apparatus in response to the increase in heat loss. Diodes, thyristors, GTOs, IGBTs, and the like are used as power semiconductor elements in the power converter, and heat pipe coolers are used as the coolers.

A heat pipe type cooler includes a rectangular parallelepiped heat receiving block and a plurality of heat pipes attached to the heat receiving block, each having a heat receiving portion and a heat radiating portion, and a plurality of heat radiating fins attached to the heat radiating portion. I have. As described in Patent Document 1, for example, pure water is generally used as a refrigerant (heat transfer medium) enclosed in the heat pipe. The reason why pure water is used as a refrigerant is that heat transfer characteristics and heat capacity are suitable for cooling semiconductor elements, so it is possible to reduce the size of the heat pipe cooler and to prevent environmental pollution. It is because it does not occur.
Japanese Patent Laid-Open No. 2003-148883 JP-A-5-248778

  By the way, in a heat pipe type cooler using a heat pipe filled with pure water as a refrigerant, it may be used below freezing point when the range of environmental conditions such as ambient temperature is wide, and it may be used below 0 ° C. Then, pure water as a refrigerant freezes. When pure water freezes, the function as a refrigerant is lost, so the heat pipe type cooler has a cooling effect obtained only by the time constant of the heat receiving block, and the cooling performance is greatly reduced. For this reason, depending on the amount of heat generated by the semiconductor element, the allowable joining temperature of the heat pipe type cooler deviates, and in the worst case, there is a risk of damage.

  On the other hand, it is conceivable to use a heat pipe enclosing an antifreeze such as ammonia, but if a heat pipe type cooler is configured using a heat pipe enclosing such a refrigerant, the cooling performance in a state where it is not frozen However, the cooling performance is inferior to that of a heat pipe type cooler configured only with a heat pipe containing pure water.

  Patent Document 2 discloses a composite heat pipe using two types of refrigerants as a technique for expanding the use environment temperature range in consideration of such refrigerant freezing. However, what is disclosed here is only an example in which two heat pipes are arranged in parallel, and there is no disclosure on how to arrange three or more heat pipes.

  The present invention has been made to solve the above-described problem, and the refrigerant operates functionally even when there are a wide range of environmental conditions such as ambient temperature using three or more heat pipes. It is an object of the present invention to provide a heat pipe type cooler that can ensure desired cooling performance.

  In order to solve the above-mentioned problems, the present invention provides a heat pipe type cooler in which three or more heat pipes each enclosing a refrigerant are attached to a heat receiving block. It is constituted by two kinds of enclosed heat pipes, and these two kinds of heat pipes are alternately arranged in the juxtaposition direction.

  In another aspect, the present invention provides a heat pipe type cooler in which four or more heat pipes each enclosing a refrigerant are attached to a heat receiving block, and the heat pipe is enclosed with a refrigerant having a different operating region. It is characterized by comprising two sets of heat pipes, a plurality of sets in which these two types of heat pipes are brought into close contact with each other, and arranged with an interval between each set.

  In still another aspect, the present invention relates to a heat pipe type cooler in which four or more heat pipes each enclosing a refrigerant are attached to a heat receiving block, and the heat pipe is encapsulated with a refrigerant having a different operation region. It is configured by a plurality of types of heat pipes, and a plurality of types of heat pipes having different refrigerants are separated for different types of refrigerants, and heat radiation fins separated for each type are provided.

  According to the heat pipe type cooler of the present invention, the operating temperature range of the entire heat pipe cooler is wide, and even if the ambient temperature fluctuates greatly, the refrigerant operates functionally in response to the temperature change, Cooling performance can be ensured.

  Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1A and 1B are a front view and a side view, respectively, showing a first embodiment of the heat pipe type cooler of the present invention. In FIG. 1, a heat pipe cooler 1 includes a rectangular parallelepiped heat receiving block 2 and eight heat pipes 3 a and 3 b attached to the heat receiving block 2. The heat pipes 3a and 3b are configured by encapsulating a refrigerant as a heat transfer medium inside a metal tube formed of a material having good thermal conductivity such as aluminum or copper, and the heat generated by the semiconductor element, It is absorbed by the heat receiving section through the heat receiving block 2, evaporates the internal refrigerant, transfers it to the heat radiating section, and releases it to the outside through the heat radiating section. A large number of heat radiation fins 4 made of a material having good thermal conductivity are attached to the heat radiation portions of the heat pipes 3a and 3b in directions orthogonal to the heat pipes 3a and 3b, respectively.

  Here, in the present embodiment, out of a total of eight heat pipes 3a and 3b arranged in two rows, two heat pipes 3a each located at both end corners in the juxtaposition direction, Pure water (operating region 30 ° C. to 200 ° C.) is enclosed as a refrigerant in the interior, and on the other hand, a total of four heat pipes 3b located in the middle portion in the juxtaposition direction are filled with antifreeze liquid. The ammonia (operating region −60 ° C. to 100 ° C.) is enclosed as a refrigerant.

  According to the heat pipe type cooler 1 configured as described above, when the ambient temperature is a temperature that does not reach below the freezing point, the heat pipe 3a with pure water and the heat pipe 3a with pure water with better cooling efficiency are used. Both the anti-freeze-containing heat pipe 3b with inferior cooling capacity operate to perform cooling. Further, when the ambient temperature becomes below freezing point and the temperature at which pure water freezes, only the heat pipe 3b containing antifreeze liquid is operated to perform cooling. Accordingly, the operating region of the heat pipe cooler 1 is expanded, and the cooling function is not completely lost even when the pure water reaches an ambient temperature where it freezes.

  FIG. 2 is a top view showing a second embodiment of the heat pipe type cooler of the present invention. This embodiment is different from the first embodiment in that two heat pipes 3a containing pure water and two heat pipes containing antifreeze liquid are alternately arranged in the juxtaposition direction. According to the present embodiment, the cooling capacity of the eight heat pipes 3a, 3b with respect to the heat receiving block is leveled, and the heat receiving block can be cooled widely and uniformly.

  FIG. 3 is a top view showing a third embodiment of the heat pipe type cooler of the present invention. This embodiment is different from the first embodiment in that the heat pipe 3a containing pure water and the heat pipe 3b containing antifreeze liquid are arranged in close contact with each other. According to the present embodiment, even when the pure water of the heat pipe 3a containing pure water reaches an ambient temperature at which the pure water freezes, the heat of the heat pipe 3b containing the antifreeze liquid that is operating is conducted to the heat pipe 3a containing pure water and the inside. Therefore, it is possible to avoid the freezing of pure water and to ensure the cooling function of the heat pipe 3b containing pure water.

  FIG. 4 is a front view and a side view showing a fourth embodiment of the heat pipe type cooler of the present invention. The difference between this embodiment and the first embodiment is that the heat pipe 3a containing pure water and the heat pipe 3b containing antifreeze liquid are arranged in two groups in the juxtaposition direction, and the heat pipes 3a and 3b of each group are arranged. The heat dissipating fins 4a and 4b that are separated from each other are individually attached.

  According to the present embodiment, it is possible to attach the heat radiation fins 4a and 4b optimized for the heat pipes 3a and 3b having different cooling characteristics, and the heat pipe cooler can be downsized.

  FIG. 5 is a front view and a side view showing a fifth embodiment of the heat pipe type cooler of the present invention. This embodiment is different from the fourth embodiment in that the heat pipe 3a containing pure water and the heat pipe 3b containing antifreeze liquid are arranged in two rows, and the heat pipes 3a and 3b in each row are radiating fins, respectively. 4a and 4b are installed separately. In the present embodiment, similarly to the fourth embodiment, it is possible to attach the radiation fins 4a and 4b optimized for the heat pipes 3a and 3b having different cooling characteristics, and the heat pipe cooler can be reduced in size. Can be achieved.

  In each of the above embodiments, the case where eight heat pipes are used has been described. However, the case where two or more heat pipes are used can be similarly implemented. In addition, although ammonia has been described as an example of the antifreeze liquid, other antifreeze liquids such as ethylene glycol and alcohol can also be used. Furthermore, not only when using antifreeze liquid alone as a refrigerant, it is also possible to use an aqueous solution mixed in pure water. Moreover, although the case where the number of heat pipes containing pure water and the number of heat pipes containing antifreeze was configured in the same number has been described, it can be configured with different numbers depending on the use environment conditions. Furthermore, the refrigerant having different operation areas in the plurality of heat pipes is not limited to the combination of pure water and antifreeze liquid, and two or more kinds of refrigerants having different operation areas other than pure water can be used in combination.

(A) And (b) is the front view and side view which respectively show 1st Embodiment in the heat pipe type cooler of this invention. It is a top view which shows 2nd Embodiment in the heat pipe type cooler of this invention. It is a top view which shows 3rd Embodiment in the heat pipe type cooler of this invention. (A) And (b) is the front view and side view which respectively show 4th Embodiment in the heat pipe type cooler of this invention. (A) And (b) is the front view and side view which respectively show 5th Embodiment in the heat pipe type cooler of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Heat pipe type cooler 2 ... Heat receiving block 3a, 3b ... Heat pipe 4a, 4b ... Radiation fin

Claims (4)

  In a heat pipe type cooler in which three or more heat pipes each enclosing a refrigerant are attached to a heat receiving block, the heat pipe is constituted by two types of heat pipes enclosing refrigerants having different operating regions, A heat pipe type cooler in which two types of heat pipes are alternately arranged in the juxtaposition direction.   In a heat pipe type cooler in which four or more heat pipes each enclosing a refrigerant are attached to a heat receiving block, the heat pipe is constituted by two types of heat pipes enclosing refrigerants having different operating regions, A heat pipe type cooler characterized in that a plurality of sets in which two types of heat pipes are brought into close contact with each other are formed and arranged with an interval between each set.   The heat pipe type cooler according to claim 1 or 2, wherein the heat pipe is constituted by a combination of two kinds of heat pipes in which a pure water refrigerant is enclosed and a heat pipe in which an antifreeze-containing refrigerant is enclosed. .   In a heat pipe type cooler in which four or more heat pipes each enclosing a refrigerant are attached to a heat receiving block, the heat pipe is constituted by a plurality of types of heat pipes enclosing refrigerants having different operation regions, A heat pipe type cooler comprising a plurality of different types of heat pipes separated into different types of refrigerants and provided with heat radiation fins separated for each type.

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