SU913481A1 - Cooling device - Google Patents

Description

The invention relates to semiconductor devices, in particular to devices for cooling high-power semiconductor elements, such as diodes, transistors, thyristors, etc.

It is known that powerful semiconductor elements emit during operation a significant amount of heat, which must be dissipated, given the relatively low permissible maximum temperature of the pn junction. The semiconductor elements are usually installed between two radiators / having fins, and are pressed to the flat upper surfaces of the radiators with an appropriate design. Heat is removed from both ends of the semiconductor element, it occurs through the walls of radiators and then dissipates in the atmosphere! 1].

Radiators for high-power semiconductor elements are usually performed.

2

from aluminum, which, however, is unsuitable for certain cases because of the insufficiently high thermal conductivity of aluminum.

Radiators can be made ⁹ of copper, as it possesses in

two times more thermal conductivity than aluminum, but copper radiators are more expensive and more complicated to make, since copper

’* Must be poured into appropriate forms, while aluminum radiators are manufactured by cooking through a press. Given the large number of semiconductor elements used, it becomes clear that copper radiators are too expensive for normal use.

The closest technical solution to the proposed device is for cooling, mainly, power semiconductor

elements containing at least

3

at least two parts, between which there is at least one semiconductor element, each of which is a body with two distribution ribs, on the periphery of which fan-shaped cooling edges are located [2].

The disadvantages of this device are significant thermal resistance and large size.

The purpose of the invention is to reduce the thermal resistance while reducing the overall dimensions.

The goal is achieved by the fact that in a device for cooling, mainly power semiconductor elements, containing at least two parts, between which at least one semiconductor element is installed, each of the parts being a body with two distribution fins, the periphery of which are fan-shaped cooling fins, the distribution fins are made wedge-shaped with a vertex angle αί equal to 14-20 °, and are located relative to each other at an angle (equal to 135 "145 °, and Yebra formed wedge with an apex angle γ, 0,25. equal to 4 °.

Figure 1 shows an embodiment of a part with ribs, a partial section, figure 2 shows a variant of a part with a heat pipe, a section, * in FIG. 3 a variant of a part of a device with two heat pipes, a section.

The device contains two parts 1 (one is shown), made of aluminum alloys. Part 1 is a body with two massive distribution main ribs 2 with an angle at the apex of ° C, having a value of 14-20 °, and which between them form an angle having a value of 135 "145 °.

Distribution ribs 2 are equipped on their periphery with fan-shaped cooling ribs 3 with a vertex angle γ equal to 0.25 “4. The part 1 produced by pressing is supplied with a copper pin 4 inserted through which heat released by the semiconductor element 5 is transferred to the part 1 and, moreover, this

913481 4

the part on the side opposite to the semiconductor element 5 is provided with a pair of reinforced i-shaped cooling fins 6. Clamping devices 7, which can consist of several leaf springs, and clamping devices 8, for example, bolts, are installed between the reinforced I-shaped cooling fins 6 of the part 1. In addition, the clamping device 7 and the clamping device 8 also have a clamping indicator 9. These devices clamp the semiconductor element 5 to the parts 1. Between the pin and 4 and the cooled semiconductor element 5 there is a gasket 10 made of insulating heat-conducting material boron. These materials have a high degree of density, good insulation resistance, good thermal conductivity and compressive strength. Item 1 is also equipped with at least one $ 2 fastener edge 11, which can be strengthened and serves as an electrical output.

In the case of a gasket 10, the electrical connection forms either a part of the semiconductor element 5 itself or it is located between the end side of this semiconductor element 5 and the gasket 10.

Due to the presence of gaskets or their absence, the proposed device ₃₅ allows for the implementation of various schemes for the incorporation of semiconductor elements, for example, single and multiphase bridge circuits, star connections and other circuits.

40 Figure 2 shows another exemplary embodiment of the device. Part 1 in this case is also a body containing two massive distribution ribs 2, equipped with

45 on its periphery fan-shaped cooling fins 3 · Also available in this variant are i-shaped cooling fins 6, between which a clamping device 8 is installed with a clamp indicator 9 and a clamping device 7, as well as reinforced fastening ribs 11. Along the longitudinal axis of the part 1 A heat pipe 12 is installed, in this case a rectangular cross section, with the copper pins 4 being an integral part of the evaporator.

Along the longitudinal axis of the part 1 can

5 913481 6

two heat pipes 12 may also be located, for example, in the form of a notch or hole (FIG. 3). A heat pipe is a device designed to transfer heat. She 5 is a closed vessel of a suitable shape, the inner walls of which are fully or partially have a capillary or osmotic structure. The inner space "0 of the vessel is filled with a suitable working medium under the required pressure, for example, distilled water, methyl alcohol, ammonia, etc. The working medium selects the heat released by the semiconductor elements during operation and changes its phase, for example, by evaporation. The resulting vapor flows under the action of a pressure difference of 20 between the evaporator and the heat pipe condenser to the condenser, where it condenses, and the energy stored in its heat of evaporation is released. Capillary or osmotic structure

sometimes also under the influence of gravitational forces / then the condensate <again to the evaporator, and this cycle is automatically repeated. zo

Due to the location of the heat pipe 12 along the longitudinal axis of the part 1 of the device. A significant improvement in the heat distribution in the longitudinal direction of the part ₃₅ 1, a uniform temperature distribution along the part 1 and thus an increase in the coefficient of action of the cooling fins 3 in the longitudinal and transverse directions of the part 1 is achieved.

Part 1 of the device can be made of aluminum or of alloys with a high aluminum content.

“Of these alloys, the most suitable

(. alloys of aluminum, suitable for processing; ⁴⁵ (pressing and also alloys

aluminum, which is made from (parts by casting. In addition, materials such as magnesium alloys, zinc ⁵⁰ die-casting alloys and casting alloys from magnesium can be used. The best material for trunnions 4 is copper and alloys with high copper content, for example bronze, brass. In other words, ⁵⁵ , the material from which pin 4 is made must have at least twice as high thermal conductivity as compared to the metal of part 1 of the device.

Pin 4 is installed in the parts by pressing in or soldering.

By arranging the cooling fins and a fan-shaped distribution angles vertex combination ribs and cooling ribs and the angle which they form a distribution ribs, the thermal resistance of the device, I ^th = 0,04-0,045 s / m, whereas in the known device I = 0.08-0.05 Рс / M, it has been experimentally proved that regardless of the size of the device, any deviation from the specified geometrical dimensions of the angles leads to a significant increase in thermal resistance. In addition to reducing the thermal resistance of the proposed device for cooling has a smaller size and weight.

In addition, the proposed device represents a significant saving of expensive copper while maintaining the very good thermal properties characteristic of copper. This is achieved due to a suitable combination of copper trunnions with distribution ribs fitted on their periphery with fan-shaped cooling fins, especially due to their geometry. ₎

A cooling device made of copper with the same thermal properties and the same cooling conditions has at least twice the weight, while the copper consumption for them increases by more than ten times.

Claims (1)

Claim A device for cooling, predominantly, power semiconductor elements, containing at least two parts, between which at least one semiconductor element is installed, each of which is a body with two distribution fins, on the periphery of which are fan-shaped cooling fins, which is due to the fact that, in order to reduce thermal resistance while reducing the overall dimensions, the distribution fins are wedge-shaped with an apex angle σί, equal to .14 -20 and are relative to each 7 913481 eight TO A FRIEND at an angle p equal to 135 “145", and the cooling fins are tapered with a vertex angle β '> equal to 0.25 ~ 4 °.