RU131238U1 - COOLING MULTI-LAYER STRUCTURE - Google Patents

Abstract

1. A cooling device made of a multilayer structure consisting of a lower metal layer applied to a cooled surface and an upper metal layer separated by at least one layer of a semiconductor material based on samarium sulfide SmS, and a circuit with a load resistor connecting the upper and lower metal layers. 2. The device according to claim 1, characterized in that samarium sulfide doped with Ln atoms of the lanthanide family SmLnS is used as the semiconductor material, wherein x=0÷0.17, y=0÷0.15 and x+y<0.17. 3. The device according to claim 2, characterized in that the value of at least one of the concentrations "x" and "y" monotonically increases in the direction from the lower metal layer to the upper metal layer. The device according to claim 2, characterized in that it includes two or more successively located layers of the semiconductor material SmLnS, wherein the value of at least one of the concentrations "x" and "y" increases from layer to layer in the direction from the lower metal layer to the upper metal layer, while within each of the mentioned layers both the concentration "x" and the concentration "y" are approximately constant. 5. The device according to claims 2-4, characterized in that gadolinium Gd or cerium Ce is used as Ln atoms, wherein the concentrations of the atoms satisfy the ratios y≤0.15, x≤0.2.

Description

The utility model relates to thermoelectric devices for cooling micro and optoelectronic objects.

The operation of electronic devices (for example, transistors, integrated circuits, laser diodes, etc.) is accompanied by heat generation. As the temperature of the device increases, its characteristics tend to deteriorate (for example, an increase in noise level, decrease in gain, decrease in useful power, etc., depending on the type of device), and with a further increase in temperature, the device may fail. This problem is especially relevant for high-speed devices for transmitting and processing information.

To stabilize or reduce the temperature of a working electronic device, air or water cooling can be used. Their disadvantages are large sizes, as well as additional energy consumption.

For cooling microobjects, thermoelectric devices based on the Peltier effect are usually used (see, US Pat. Nos. 3006979, 3409475, 4859250). They are made of a pair or several pairs of electrodes made of materials with different Peltier coefficients. When electric current is passed through such compounds due to the Peltier effect, heat is absorbed in the region of one of the contacts (group of contacts) of dissimilar materials, and heat is released in the region of the other contact (group of contacts). A variant of the device for cooling based on the Peltier effect are multistage elements (US patent No. 5040381, 4833889, 5385022). Another option described in the patent of the Russian Federation No. 2310950 is a Peltier-based thermoelectric device in which the heat absorbed in the area of thermoregulation is released on the switching platforms located at a considerable distance from the thermoregulated area.

The main disadvantage of devices based on the use of the Peltier effect is the need to pass an electric current through them, which will lead to additional electricity consumption, which can be comparable to or even exceed the energy consumption of a cooled micro (opto) electronics device.

As a prototype of the proposed device, the device described in the patent of the Russian Federation No. J2851 was selected based on the effect of cooling a sample of semiconductor samarium sulfide (SmS) detected by the author when generating voltage due to the thermovoltaic effect that occurs when the sample is heated.

The prototype device is a layered structure consisting of a layer of semiconductor material SmS (samarium sulfide) and a layer of solid solution Sm _1-x Yy _x S (Yy denotes one of the following elements: La, Ce, Gd, Pr, Nd, Dy, Ho (Er) with contact pads electrically connected to the external surfaces of the layered structure and connected to them by current outputs, closed to each other through the electrical resistance of the load. When the structure is heated, the temperature of the contact pad on the SmS layer increases faster than the temperature of the contact pad on the Sm _1-x Yy _x S layer, which makes it possible to use the contact pad on the Sm _1-x Yy _x S layer for heat control of the object. An excess of thermal energy is released on the load electrical resistance, which can be brought to the necessary distance from the heat-regulated region due to the lengthening of the current outputs. The prototype device allows you to implement a stable and continuous process of cooling a micro-object without using sources of electricity for the functioning of the cooling device.

The disadvantages of the prototype device is the low value of the heat output, which is limited by the maximum values of current and voltage (their products), which can be generated by the SmS / Sm _1-x Yy _x S structure when heated. As a result, the prototype device is able to provide cooling of objects by a few grams cash desk by only 30-40 ° C.

Another disadvantage of the prototype device is the difficulty of ensuring good thermal contact between the prototype device and the surface of the cooled electronic device. This is due to the fact that the contacted surface of the cooled electronic device (for example, the substrate surface of the electronic microcircuit), as a rule, is not perfectly flat, which makes it difficult to snugly fit the prototype device to it.

The proposed utility model solves the problem of creating a device that operates without the use of electric power sources, capable of efficiently cooling micro and optoelectronic objects.

A device for cooling objects of micro- and optoelectronics, made in the form of a multilayer coating deposited on the surface to be cooled, consisting of a lower metal layer, on top of which at least one layer of semiconductor material Sm _{1 + x} Ln _y S is applied, where x = 0 ÷ 0.17, y = 0 ÷ 0.15, with x + y <0.17, and the upper metal layer connected to the lower metal layer through a remote load resistance, and the value of at least one of the concentrations "x" and " y "monotonically increases in the direction from the lower m the metallic layer to a top metal layer. Here, Ln denotes atoms trivalent in monosulfides that belong to group III of the 6th period of the periodic table of elements with the exception of samarium Sm. These include, for example, gadolinium atoms Gd and cerium Ce.

A cooling device may include two or more layers of the semiconductor material Sm _{1 + x} Ln _y S arranged in such a way that at least one of the concentrations “x” and “y” increases from layer to layer in the direction from the lower metal layer to the upper metal layer, while within each of the mentioned layers both the concentration "x" and the concentration "y" are approximately constant.

The principle of operation of the device is based on the fact that when a multilayer coating is applied to the surface of the micro- and optoelectronics object that needs to be cooled, reliable thermal contact is ensured even if the surface to be cooled is non-planar. The applied first metal layer and subsequent layers of the multilayer structure repeat the roughness of the original surface, thereby ensuring a reliable fit of the multilayer structure to it.

The principle of the device’s operation is also based on the fact that in a semiconductor structure in which there is a concentration gradient of excess Samarium atoms Sm (concentration gradient “x”) and / or a concentration gradient of doping atoms belonging to the Ln families n Ln (concentration gradient “y”), under the action of heat generated by the object that needs to be cooled, due to the thermovoltaic effect, the generation of electrical voltage (thermo-EAS) occurs.

The device operates as follows. Between the lower metal layer of the device and the surface to be cooled, thermal contact is made. During the functioning of the cooled object (optoelectronic or microelectronic device), heat is released. Due to the generation of thermo-EAS in the electrical circuit formed by the upper and lower metal layers of the multilayer structure, closed through the load resistance, an electric current begins to flow. The flow of electric current in turn causes the heating of the load resistance, accompanied by dissipation of heat in a region of space remote from the cooled object.

Thus, the proposed device converts the heat released from the surface to be cooled into electrical power, which is then converted again into the heat released on the remotely located load resistance. As a result of heat removal from the object, it is cooled.

The author of this useful milling found that the thermovoltaic effect is enhanced if an inhomogeneous concentration of impurity atolls Ln belonging to the lanthanide family (elements is created in samarium sulfide SmS or in Sm _{1 + x} S (samarium sulfide containing excess samarium atolls) Group III of the 6th period of the periodic table), showing valency 3 in combination with sulfur. The discovered phenomenon is most likely due to the fact that the additional electron that is formed in the conduction band of samarium sulfide when an additional trivalent atom is introduced into it increases the conductivity of the semiconductor compound compared to the starting material. As a result, there is an increase in the maximum value of electric power that can be generated by the device and, as a result, an increase in the maximum value of thermal power that can be diverted from the cooled object.

The author of this utility model found that if the concentration "x" exceeds 0.17, there is a separation of the phase of metallic samarium. The author also found that if the concentration "y" exceeds 0.15, the thermovoltaic effect will be absent due to the transition of samarium ions to the trivalent state. In addition, if x + y exceeds 0.17, one or both of these unwanted effects will be observed.

The inventive utility model is illustrated by drawings, where:

figure 1 schematically shows a design variant of the inventive device containing one layer of semiconductor material Sm _{1 + x} Ln _y S gradient concentration;

figure 2 schematically shows another design option of the inventive device containing two layers of semiconductor material Sm _{1 + x} Ln _y S, differing in their chemical composition. The utility model may also contain more than two layers Sm _{1 + x} Ln _y S;

figure 3 shows a diagram of an experimental device used to demonstrate the effect of self-cooling.

The inventive device shown in FIG. 1 is deposited on the surface 1, which needs to be cooled, and includes a lower metal layer 2, one layer 3 of the semiconductor material Sm _{1 + x} Ln _y S with a monotonously increasing concentration of "x" 4 excess Sm 5 atoms and the concentration " y "6 doping atoms Ln 7, upper metal layer 8, electrical connections 9, remote load resistance 10.

The inventive device depicted in FIG. 2 is deposited on a surface 1, which must be cooled and includes a lower metal layer 2, two layers 3.1 and 3.2 of the semiconductor material Sm _{1 + x} Ln _y S, within each of which there is a concentration of “x” 4 excess Sm atoms 5 and the concentration “y” 6 of the doping atoms of Ln 7 are approximately constant and increase in the direction from layer 3.1 to layer 3.2, the upper metal layer 8, electrical connections 9, remote load resistance 10. The utility model may also contain more than two layers Sm _{1 + x} Ln _y S within a zhdogo concentration of which "x" 4 redundant atoms 5 and Sm concentration "y" 6 7 Ln dopant atoms are approximately constant and increasing in the direction from the layer adjacent to the cooled surface to the outermost layer of it.

Example 1

On a molybdenum plate 1 with dimensions 20 × 20 × 0.75 mm, which was a cooled surface and at the same time the lower contact, a sample was created (deposited in a high-frequency furnace) with layers 2 of Sm _1.02 Gd _0.07 S and 3 of SmS with dimensions 8 × 6 × 4 mm (Figure 3). The resistance of this structure was 3.2 ohms. A metal layer was formed on the outer surface, forming a contact pad 4.

In this experiment, cooling was carried out by closing the electrodes (the contact pad 4 and the cooled surface 1) using a load resistance 5, which is close to the structure resistance, R = 3 Ohms. The following equipment was used: for heating an electric drying cabinet round 2 В-151 ГУ 54-1-1411-76; temperature was measured with chromel-alumel thermocouples in accordance with GOST R 8.585-2001; the signals were output to a computer with an MD-M2 ADC.

The ambient temperature was measured with a thermocouple adjacent to layer 3. The temperature of the cooled surface was measured with a thermocouple adjacent to surface 1. With increasing ambient temperature, the temperature of the cooled surface increased more slowly than the ambient temperature. When the ambient temperature reached 98 ° C, the temperature of the cooling surface reached 56 ° C and was stably maintained throughout the experiment for 1 hour.

Thus, as a result of applying 2 layers of materials based on samarium sulfide onto a cooled surface, it was possible to lower the temperature of an object weighing 3 g by 42 ° C compared with an increased temperature of the medium. This temperature difference was maintained without the use of an external electrical source. Thus, the effect of self-cooling was achieved.

Example 2

A structure similar to that described in Example 1 was made. After that, the structure was heated to T = 1500 ° C in vacuo and held for 30 minutes. As a result of thermal diffusion, two layers with the compositions Sm _1.02 Gd _0.07 S and SmS were sintered into a single sample, and a gradient of samarium ions formed in the boundary region with a width of ~ 2 mm (an excess compared to the stoichiometric composition from 0 to 0.02) and an ion gradient gadolinium (excess compared to stoichiometric SmS from 0 to 0.07). The diffusion depth 7 (~ 1 mm) was calculated based on the known diffusion coefficients. The resistance of this structure was 1.5 ohms.

The experimental design and the instruments used were the same as in Example 1, however, the load resistance was 1 Ohm. With increasing ambient temperature, the temperature of the cooled surface increased more slowly than the ambient temperature. When the ambient temperature reached 99 ° C, the temperature of the cooled surface reached only 52 ° C and was stably and continuously maintained throughout the experiment for 1 hour.

Thus, as a result of the experiment, it was possible to lower the temperature of an object weighing 3 g by 47 ° C compared with the temperature of a heating medium and maintain this temperature difference without using an external electric source.

These examples show that the coatings described in this utility model prevent overheating of the surface on which they are applied. They can be applied to surfaces of any configuration with different radii of curvature.

Claims (5)

1. A cooling device made of a multilayer structure consisting of a lower one deposited on a cooled surface and an upper metal layer separated by at least one layer of semiconductor material based on samarium sulfide SmS, and a circuit with load resistance connecting the upper and lower metal layers. 2. The device according to claim 1, characterized in that samarium sulfide doped with Ln atoms of the lanthanide family Sm _{1 + x} Ln _y S is used as a semiconductor material, with x = 0 ÷ 0.17, y = 0 ÷ 0.15 and x + y <0.17. 3. The device according to claim 2, characterized in that the value of at least one of the concentrations "x" and "y" monotonically increases in the direction from the lower metal layer to the upper metal layer. 4. The device according to claim 2, characterized in that it includes two or more successive layers of semiconductor material Sm _{1 + x} Ln _y S, and the value of at least one of the concentrations "x" and "y" increases from layer to layer in the direction from the lower metal layer to the upper metal layer, while within each of said layers both the concentration “x” and the concentration “y” are approximately constant. 5. The device according to claims 2-4, characterized in that the gadolinium Gd or cerium Ce is used as Ln atoms, and the atomic concentrations satisfy the ratios y≤0.15, x≤0.2.

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