DE8915913U1 - Arrangement for cooling power semiconductors via heat pipes - Google Patents

Description

Licentia Patent Management GmbH
Theodor-Stern-Kai 1
D-6000 Frankfurt 70

PTL-B/Rü-zg

B91/26

Arrangement for cooling power semiconductors via heat pipes

The invention relates to an arrangement for cooling power semiconductors, in which the heat is dissipated by an insulated, water-cooled heat pipe.

Such an arrangement is known, for example, from European patent application 0 233 103. In this arrangement, the heat pipe consists of a metallic evaporator at the heat source, to which a tube made of heat-conducting aluminum ceramic is attached via an elastic connecting piece, with this condensation side being surrounded by cooling water.

Compared to conventional air cooling with free or forced convection using finned heat sinks, other types of cooling such as water cooling, evaporative cooling or heat pipe cooling are more effective cooling systems that can also handle greater power losses. However, the disadvantage of many arrangements is the need for insulation between the heat source and heat sink, which in turn reduces the cooling efficiency. The previously mentioned combination of heat pipe cooling with water cooling partially eliminates this disadvantage, but without achieving the cooling performance of normal heat pipes.

The object of the invention is to further improve the heat transfer of insulated heat pipes on the condensation side and thus the cooling efficiency and to make them usable for use on vehicles. This object is achieved according to the characterizing features of claim 1. Advantageous embodiments can be found in the subclaims.

, ₅ A heat pipe that is well suited for this purpose is, for example, the

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DE 37 09 006 C1 became known.

The figures in the drawing outline the invention.

Fig. 1 shows a heat pipe with an outer metal pipe part 1, e.g. made of Al or Cu, which is attached to the heat source, e.g. a semiconductor. Another metal pipe part 2 is provided for the heat sink. Up to now, an air cooler consisting of many plates has been attached there. In between there is a tubular insulating body, designated 3, as an insulating section laid in the heat pipe. The insulating body 3 - it is only shown schematically as being this long - is fitted onto the metal pipe parts 1 and 2 and connected in a vacuum-tight manner (e.g. glued, soldered or welded) at the internally metallized connection points 4 and 5. The heat transfer medium, an insulating liquid, e.g. Frigen, is designated 6 and 7 represents a filling pipe that has been squeezed off and welded after the heat pipe has been filled. The insulated heat pipe is clearly provided with a uniform ribbed profile or a capillary structure on the inside, whereby the thermodynamic heat transport is not hindered and the return transport of the capacitor is promoted. In this case, a metallic heat sink with holes 9 for a cooling water flow is connected in a good heat-conducting manner to the metallic pipe part 2 for the heat sink. The heat pipe can be operated horizontally - as shown - but also vertically or at an angle. The pipe part 1 can have a receiving surface for the semiconductors to be cooled, e.g. as shown in Fig. 2.

Fig. 2 shows another design in which the metallic tube part 1 of the heat pipe is embedded in a metallic base body 10, which rests on a heat source indicated by dashed lines at 11 (e.g. a disk semiconductor). 3 again represents the ceramic insulator for the

This is referred to as electrical longitudinal insulation. This is followed by the metal pipe section 2 of the condensation area, around which the cooling water flows directly via a form-fitting component 12. The heat transfer is particularly good here. The component 12 is sealed at the points opposite to the pipe section 2.

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The water cooling system can also simply consist of several metal pipe windings that tightly enclose the pipe structure of the heat sink. The surface contact should be as large as possible. Several, even different water cooling systems with different heat pipes can be connected to the same water circuit and they can be at the potential of the vehicle mass, i.e. they can be connected directly to a cooling circuit of the vehicle. The mounting position of such heat pipes can be selected taking into account the condensate return. The arrangement described is designed in particular for highly stressed semiconductors. Semiconductors that are subject to less stress are cooled, as is known, via insulating disks that are located between the semiconductor and the water cooling boxes. The latter can be in the same water cooling circuit as the heat pipes. The invention offers the possibility of shortening the heat pipes. The length only depends on the required condensation surface. The advantages of the arrangement according to the invention can be summarized as follows:

1. smaller overall thermal resistance

2. No need for deionization of the cooling water, as the condensation part is potential-free compared to the actual heat pipe

3. Recooling of the secondary heat carrier (water) at any location

4. easy manufacture of water cooling elements.

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Claims (6)

Licentia Patent-Verwaltungs-GmbH Theodor-Stern-Kai 1 D-6000 Frankfurt 70 PTL-B/Rü-zg B 91/26 Protection claims 1. Arrangement for cooling power semiconductors, in which heat is dissipated through an insulated, water-cooled heat pipe, characterized in that that a multi-part, longitudinally electrically insulating heat pipe with metallic tube structures (1, 2) located at the end of the heat source and heat sink, which are electrically insulated from one another by a tubular insulating body (3), is used, and that a water cooling system dissipates the heat directly from the metallic tube structure (2) of the heat sink. 2. Arrangement according to claim 1, characterized, that service water is used and the water cooling system is connected to the vehicle ground. 3. Arrangement according to claim 1 or 2, characterized, that the water cooling system consists of several metallic pipe windings, which tightly enclose the pipe structure (2) of the heat sink with as large an area as possible and through which the cooling water flows. 4. Arrangement according to claim 1 or 2, characterized, that the water cooling system consists of a metallic component (8) which is positively placed on the pipe structure (2) of the heat sink and which is provided with holes (9) for the passage of cooling water. - 5 - B91/26 1 5. Arrangement according to claims 1 or 2, 4, characterized in that the attached component (12) is designed in such a way that the cooling water flows directly around the pipe structure (2) of the heat sink. 6. Arrangement according to one of the preceding claims, characterized in that multiple water cooling systems for multiple heat pipes can be connected to the same IO water circuit.