Preparation method of thermoelectric refrigerating unit and thermoelectric refrigerating unit

Abstract

The invention relates to the technical field of semiconductor coolers, and discloses a preparation method of a thermoelectric refrigerating unit and the thermoelectric refrigerating unit. According to the method, blocking metal is arranged on the surfaces of semiconductor particles to block copper elements in a flow guide body and tin elements in soldering paste from migrating to the surfaces of the semiconductor particles; the damage effect on semiconductor particles when copper is used as a flow guide body is avoided, and the service life of the thermoelectric refrigerating unit is remarkably prolonged; the stress groove is formed in the flow guide body of the thermoelectric refrigerating unit, on one hand, the problem that after scaling powder volatilizes, semiconductor particles and the flow guide copper sheet are in contact extrusion and have no place to be discharged is solved, air holes are avoided, and on the other hand, the semiconductor particles and the flow guide copper sheet can not be in direct contact completely. The thermal stress generated in the working process of the semiconductor particles is reduced, the contact area of the thermoelectric refrigerating unit semiconductor particles and the flow guide copper sheet is reduced, the heat transfer resistance is increased, and the risk of thermal short circuit can be reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor refrigerators, and in particular to a preparation method of a thermoelectric refrigerator and the thermoelectric refrigerator. Background Art

[0002] Thermoelectric cooler (TEC) is an important functional component in PCR detection instruments. Generally, the temperature change rate of PCR is 3-4°C / S. In order to improve the efficiency of PCR detection, the prior art discloses a rapid PCR detection. The temperature change rate required for rapid PCR detection is 7-8°C / S. Since the temperature change frequency of rapid PCR increases, it poses greater challenges to the thermal deformation resistance and welding effect of the thermoelectric cooler.

[0003] The thermoelectric cooler is composed of a semiconductor and a conductive body welded on the semiconductor. The material of the semiconductor particles is Bi2Te3. The conductive body is usually made of aluminum. The solder paste used for welding is usually made of tin. For example, the publication number CN114623623A discloses a TEC semiconductor cooling sheet packaged with a metal panel. Since fast PCR has higher requirements for the thermal deformation resistance of the thermoelectric cooler, people in this field have proposed to use copper with larger current carrying capacity and better thermal deformation resistance as the conductive body. However, since copper is a companion element of bismuth and has a very high affinity with bismuth, during the operation of TEC, copper will pass through the TEC. The tin in the solder paste acts as a bridge to migrate to the semiconductor. At the same time, tin and tellurium are also relatively friendly. The migration of these elements destroys the thermoelectric properties of the semiconductor. In addition, the reliability of the thermoelectric cooler during operation is directly related to the cross-sectional area of ​​the semiconductor particles. During the welding process, the flux volatilization in the solder paste is not well eliminated, and the flux remaining between the semiconductor particles and the guide copper sheet will form pores, R=ρL / S. The effective contact area between the semiconductor particles and the guide copper sheet is reduced, which will inevitably lead to an increase in the thermal resistance of a single semiconductor. Under rapid temperature change conditions, a single semiconductor particle will burn out and fail, thereby affecting the service life of the TEC.

[0004] The current conventional solution is to depressurize the TEC during heating, and to extract the volatilized flux in the welding material by vacuuming, thereby ensuring that there are no pores on the contact surface between the semiconductor particles and the guide plate. However, due to the lack of pressurization, it is necessary to increase the amount of solder paste to ensure that the particles and the guide plate are fully soldered (no cold solder joints), which also provides better conditions for the diffusion of the Cu element and increases the risk of TEC failure. Summary of the invention

[0005] In order to overcome the problem in the prior art that the performance of thermoelectric materials of thermoelectric refrigerators is degraded due to element diffusion, the present invention provides a method for preparing a thermoelectric refrigerator. The method arranges a barrier metal on the surface of semiconductor particles to block the migration of copper elements in the conductive body and tin elements in the solder paste to the surface of the semiconductor particles, thereby avoiding the destructive effect of copper on the semiconductor particles when used as the conductive body, and significantly improving the working life of the thermoelectric refrigerator.

[0006] The specific technical scheme of the present invention is: A method for preparing a thermoelectric cooler is characterized in that it includes the following steps: attaching a barrier metal to the surface of a semiconductor particle and then attaching an electroplating layer to form a pre-processed semiconductor, and thermally compounding a conductive body provided with solder paste with the pre-processed semiconductor to form a thermoelectric cooler.

[0007] The present invention provides a method for preparing a thermoelectric cooler. The method arranges a barrier metal on the surface of the semiconductor to block the migration of the copper element in the conductive body and the tin element in the solder paste to the surface of the semiconductor particles, thereby avoiding the destructive effect of copper on the semiconductor particles when used as the conductive body, and significantly improving the working life of the thermoelectric cooler. Since the barrier metal has no weldability, it is necessary to nickel-plate and tin-plate the barrier metal so that the surface of the semiconductor particles has weldability. At the same time, the nickel-plating and tin-plating can reduce the amount of solder paste on the surface of the conductive body.

[0008] Preferably, the barrier metal has a thickness of 1 to 30 μm, and the barrier metal is one or more of aluminum, titanium and tungsten.

[0009] Preferably, the barrier metal is one or more of aluminum, titanium and tungsten.

[0010] The barrier metals in the present invention are preferably aluminum, titanium and tungsten. The barrier metals will produce barrier resistance, and the barrier resistances of aluminum, titanium and tungsten decrease in sequence. The barrier resistances of other metals are all greater than the above three metals and cannot be used as barrier metals.

[0011] Preferably, the semiconductor particles are Bi2Te3.

[0012] Preferably, the attachment method is sandblasting.

[0013] Preferably, the body conductor is copper.

[0014] Preferably, the solder paste is printed on the surface of the flow conductor.

[0015] A thermoelectric cooler comprises semiconductor particles and a fluid conductor welded on the welding surface of the semiconductor particles, a barrier metal layer is provided on the welding surface of the semiconductor particles, an electroplating layer is provided on the barrier metal layer, a solder paste layer is provided on the side of the fluid conductor welded to the welding surface of the semiconductor particles, and a substrate is provided on the other side of the fluid conductor. The thermoelectric cooler is manufactured using the above-mentioned method for preparing the thermoelectric cooler.

[0016] Preferably, a stress groove is provided on the body-conducting body, and the stress groove is located on a side of the body-conducting body where the solder paste layer is provided, and no solder paste layer is provided in the stress groove.

[0017] Preferably, the stress groove is a vertical groove.

[0018] The present invention also provides a thermoelectric refrigerator, which is made by the above-mentioned preparation method. A stress groove is provided on the body of the thermoelectric refrigerator. On the one hand, the stress groove solves the problem that the flux has nowhere to be discharged after volatilization due to the contact and squeezing of the semiconductor particles and the guide copper sheet, thereby avoiding the formation of pores. On the other hand, the stress groove can prevent the semiconductor particles and the guide copper sheet from being in complete direct contact, thereby reducing the thermal stress generated by the semiconductor particles during operation. In addition, the contact area between the semiconductor particles of the thermoelectric refrigerator and the guide copper sheet is reduced, the heat transfer thermal resistance is increased, and the risk of thermal short circuit can be reduced.

[0019] Compared with the prior art, this application has the following technical effects: (1) The present invention provides a method for preparing a thermoelectric cooler. The method arranges a barrier metal on the surface of the semiconductor to prevent the copper element in the conductive body and the tin element in the solder paste from migrating to the surface of the semiconductor particles, thereby avoiding the destructive effect of copper on the semiconductor particles when used as the conductive body, and significantly improving the working life of the thermoelectric cooler.

[0020] (2) The present invention also provides a thermoelectric cooler, in which a stress groove is provided on the body of the thermoelectric cooler. The stress groove solves the problem that the flux has nowhere to be discharged after volatilization due to the contact and squeezing of the semiconductor particles with the guide copper sheet, thereby avoiding the formation of pores. On the other hand, the stress groove can prevent the semiconductor particles from being in direct contact with the guide copper sheet, thereby reducing the thermal stress generated by the semiconductor particles during operation. In addition, the contact area between the semiconductor particles and the guide copper sheet of the thermoelectric cooler is reduced, the heat transfer resistance is increased, and the risk of thermal short circuit can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a cross-sectional view of the thermoelectric cooler of the present invention.

[0022] In the figure, semiconductor particles 1, barrier metal layer 101, electroplating layer 102, fluid conductor 2, solder paste layer 201, stress groove 202, glue 203 and substrate 3 are shown. DETAILED DESCRIPTION

[0023] The present invention will be further described below in conjunction with the embodiments.

[0024] Embodiment 1: like Figure 1 As shown, a thermoelectric cooler comprises semiconductor particles 1 and a fluid conductor 2 welded on the welding surface of the semiconductor particles, the semiconductor particles are made of Bi2Te3, the fluid conductor is made of copper, a barrier metal layer 101 is provided on the semiconductor welding surface, an electroplating layer 102 is provided on the barrier metal layer, the thickness of the barrier metal layer is 6 to 10 μm, a solder paste layer 201 and a stress groove 202 are provided on the side of the fluid conductor for welding with the welding surface of the semiconductor particles, and no solder paste layer is provided in the stress groove; the fluid conductor is provided on a substrate, and the fluid conductor is connected to the substrate through glue 203.

[0025] A method for preparing the above-mentioned thermoelectric cooler comprises the following steps: The barrier metal (aluminum powder) is sprayed on the surface of the wafer cut from the semiconductor crystal rod, and then nickel-plated and tin-plated to make a pre-treated wafer, and the pre-treated wafer is cut into semiconductor particles of corresponding sizes; the flow conductor (copper sheet) is cleaned, and glue is brushed on the surface of the substrate (ceramic sheet) according to the arrangement position of the flow conductor, and then the cleaned flow conductor is pasted to the glue-coated substrate, and then a semi-finished product is made after high-temperature curing and surface anti-oxidation treatment, and the surface of the flow conductor of the semi-finished product is milled to produce stress grooves to obtain the upper substrate and lower substrate of the load conduction; a layer of solder paste is printed on the flow conductors of the upper substrate and the lower substrate respectively, and then the welding surface of the semiconductor particle is placed on the corresponding flow conductor of the lower substrate, and then the flow conductor of the upper substrate is covered on the other welding surface of the corresponding semiconductor particle and fixed on the heating base using TEC clamping, and then the semi-finished thermoelectric cooler is pressurized and sent into the heating equipment through a fixture for heating and welding, and the volatilized flux in the solder is extracted by vacuum during heating, and the thermoelectric cooler is cooled and cleaned after the welding is completed.

[0026] Embodiment 2: like Figure 1 As shown, a thermoelectric cooler comprises semiconductor particles 1 and a fluid conductor 2 welded on the welding surface of the semiconductor particles, the semiconductor particles are made of Bi2Te3, the fluid conductor is made of copper, a barrier metal layer 101 is provided on the semiconductor welding surface, an electroplating layer 102 is provided on the barrier metal layer, the thickness of the barrier metal layer is 3 μm, a solder paste layer 201 and a stress groove 202 are provided on the side of the fluid conductor for welding with the welding surface of the semiconductor particles, and no solder paste layer is provided in the stress groove; the fluid conductor is provided on a substrate, and the fluid conductor is connected to the substrate through glue 203.

[0027] A method for preparing the above-mentioned thermoelectric cooler comprises the following steps: The barrier metal (aluminum powder) is sprayed on the surface of the wafer cut from the semiconductor crystal rod, and then nickel-plated and tin-plated to make a pre-treated wafer, and the pre-treated wafer is cut into semiconductor particles of corresponding sizes; the flow conductor (copper sheet) is cleaned, and glue is brushed on the surface of the substrate (ceramic sheet) according to the arrangement position of the flow conductor, and then the cleaned flow conductor is pasted to the glue-coated substrate, and then a semi-finished product is made after high-temperature curing and surface anti-oxidation treatment, and the surface of the flow conductor of the semi-finished product is milled to produce stress grooves to obtain the upper substrate and lower substrate of the load conduction; a layer of solder paste is printed on the flow conductors of the upper substrate and the lower substrate respectively, and then the welding surface of the semiconductor particle is placed on the corresponding flow conductor of the lower substrate, and then the flow conductor of the upper substrate is covered on the other welding surface of the corresponding semiconductor particle and fixed on the heating base using TEC clamping, and then the semi-finished thermoelectric cooler is pressurized and sent into the heating equipment through a fixture for heating and welding, and the volatilized flux in the solder is extracted by vacuum during heating, and the thermoelectric cooler is cooled and cleaned after the welding is completed.

[0028] Embodiment 3: like Figure 1 As shown, a thermoelectric cooler comprises semiconductor particles 1 and a fluid conductor 2 welded on the welding surface of the semiconductor particles, the semiconductor particles are made of Bi2Te3, the fluid conductor is made of copper, a barrier metal layer 101 is provided on the semiconductor welding surface, an electroplating layer 102 is provided on the barrier metal layer, the thickness of the barrier metal layer is 30 μm, a solder paste layer 201 and a stress groove 202 are provided on the side of the fluid conductor for welding with the welding surface of the semiconductor particles, and no solder paste layer is provided in the stress groove; the fluid conductor is provided on a substrate, and the fluid conductor is connected to the substrate through glue 203.

[0029] A method for preparing the above-mentioned thermoelectric cooler comprises the following steps: The barrier metal (aluminum powder) is sprayed on the surface of the wafer cut from the semiconductor crystal rod, and then nickel-plated and tin-plated to make a pre-treated wafer, and the pre-treated wafer is cut into semiconductor particles of corresponding sizes; the flow conductor (copper sheet) is cleaned, and glue is brushed on the surface of the substrate (ceramic sheet) according to the arrangement position of the flow conductor, and then the cleaned flow conductor is pasted to the glue-coated substrate, and then a semi-finished product is made after high-temperature curing and surface anti-oxidation treatment, and the surface of the flow conductor of the semi-finished product is milled to produce stress grooves to obtain the upper substrate and lower substrate of the load conduction; a layer of solder paste is printed on the flow conductors of the upper substrate and the lower substrate respectively, and then the welding surface of the semiconductor particle is placed on the corresponding flow conductor of the lower substrate, and then the flow conductor of the upper substrate is covered on the other welding surface of the corresponding semiconductor particle and fixed on the heating base using TEC clamping, and then the semi-finished thermoelectric cooler is pressurized and sent into the heating equipment through a fixture for heating and welding, and the volatilized flux in the solder is extracted by vacuum during heating, and the thermoelectric cooler is cooled and cleaned after the welding is completed.

[0030] Embodiment 4: like Figure 1 As shown, a thermoelectric cooler comprises semiconductor particles 1 and a fluid conductor 2 welded on the welding surface of the semiconductor particles, the semiconductor particles are made of Bi2Te3, the fluid conductor is made of copper, a barrier metal layer 101 is provided on the semiconductor welding surface, an electroplating layer 102 is provided on the barrier metal layer, the thickness of the barrier metal layer is 6 to 10 μm, a solder paste layer 201 and a stress groove 202 are provided on the side of the fluid conductor for welding with the welding surface of the semiconductor particles, and no solder paste layer is provided in the stress groove; the fluid conductor is provided on a substrate, and the fluid conductor is connected to the substrate through glue 203.

[0031] A method for preparing the above-mentioned thermoelectric cooler comprises the following steps: The barrier metal (titanium powder) is sprayed on the surface of the disc cut from the semiconductor crystal rod, and then nickel-plated and tin-plated to make a pre-treated disc, and the pre-treated disc is cut into semiconductor particles of corresponding size; the flow conductor (copper sheet) is cleaned, and glue is brushed on the surface of the substrate (ceramic sheet) according to the arrangement position of the flow conductor, and then the cleaned flow conductor is pasted to the glue-coated substrate, and then a semi-finished product is made after high-temperature curing and surface anti-oxidation treatment, and the surface of the flow conductor of the semi-finished product is milled to produce stress grooves to obtain the upper substrate and lower substrate of the load conduction; a layer of solder paste is printed on the flow conductors of the upper substrate and the lower substrate respectively, and then the welding surface of the semiconductor particle is placed on the corresponding flow conductor of the lower substrate, and then the flow conductor of the upper substrate is covered on the other welding surface of the corresponding semiconductor particle and fixed on the heating base using TEC clamping, and then the semi-finished thermoelectric cooler is pressurized and sent into the heating equipment through a fixture for heating and welding, and the volatilized flux in the solder is extracted by vacuum during heating, and the thermoelectric cooler is cooled and cleaned after the welding is completed.

[0032] Embodiment 5: like Figure 1 As shown, a thermoelectric cooler comprises semiconductor particles 1 and a fluid conductor 2 welded on the welding surface of the semiconductor particles, the semiconductor particles are made of Bi2Te3, the fluid conductor is made of copper, a barrier metal layer 101 is provided on the semiconductor welding surface, an electroplating layer 102 is provided on the barrier metal layer, the thickness of the barrier metal layer is 6 to 10 μm, a solder paste layer 201 and a stress groove 202 are provided on the side of the fluid conductor for welding with the welding surface of the semiconductor particles, and no solder paste layer is provided in the stress groove; the fluid conductor is provided on a substrate, and the fluid conductor is connected to the substrate through glue 203.

[0033] A method for preparing the above-mentioned thermoelectric cooler comprises the following steps: The barrier metal (tungsten powder) is sprayed on the surface of the wafer cut from the semiconductor crystal rod, and then nickel-plated and tin-plated to make a pre-treated wafer, and the pre-treated wafer is cut into semiconductor particles of corresponding sizes; the flow conductor (copper sheet) is cleaned, and glue is brushed on the surface of the substrate (ceramic sheet) according to the arrangement position of the flow conductor, and then the cleaned flow conductor is pasted to the glue-coated substrate, and then a semi-finished product is made after high-temperature curing and surface anti-oxidation treatment, and the surface of the flow conductor of the semi-finished product is milled to produce stress grooves to obtain the upper substrate and lower substrate of the load conduction; a layer of solder paste is printed on the flow conductors of the upper substrate and the lower substrate respectively, and then the welding surface of the semiconductor particle is placed on the corresponding flow conductor of the lower substrate, and then the flow conductor of the upper substrate is covered on the other welding surface of the corresponding semiconductor particle and fixed on the heating base using TEC clamping, and then the semi-finished thermoelectric cooler is pressurized and sent into the heating equipment through a fixture for heating and welding, and the volatilized flux in the solder is extracted by vacuum during heating, and the thermoelectric cooler is cooled and cleaned after the welding is completed.

[0034] Comparative Example 1: Compared with the embodiment, no barrier metal is provided in comparative example 1, and other conditions are the same as those of the embodiment.

[0035] Comparative Example 2: Compared with the embodiment, no electroplating layer is provided in Comparative Example 2, and other conditions are the same as those of the embodiment.

[0036] Comparative Example 3: Compared with the embodiment, the flow guide in Comparative Example 3 uses aluminum, and the other conditions are the same as those in the embodiment.

[0037] Comparative Example 4: Compared with the embodiment, other metals are selected as the barrier metal in comparative example 4, and the other conditions are the same as those in the embodiment.

[0038] Comparative Example 5: Compared with the embodiment, no stress groove is provided in comparative example 5, and other conditions are the same as those of the embodiment.

[0039] Comparative Example 6: Compared with the embodiment, the thickness of the barrier metal in Comparative Example 6 is too large, which is 50 μm, and the other conditions are the same as those of the embodiment.

[0040] Comparative Example 7: Compared with the embodiment, the thickness of the barrier metal in comparative example 7 is too small, which is 0.5 μm, and the other conditions are the same as those in the embodiment.

[0041] Test example: The working life of the thermoelectric coolers prepared in the above-mentioned embodiments 1 to 5 and comparative examples 1 to 7 was tested. The working life of the thermoelectric cooler was measured by the number of heat exchanges of the thermoelectric cooler when the resistance change rate was 5%. Resistance change rate test method: There are a variety of test methods according to different needs. In this example, the accelerated life test is used. The test steps include: welding wires to the thermoelectric coolers made in the embodiments and comparative examples, and installing them into the accelerated life test platform. The test conditions are 1 cycle of 40 seconds / (20s cooling temperature drops to 40°C, 20s heating temperature rises to 90°C, pressure 28±2kg, and current can be adjusted according to actual needs). The test results are shown in Table 1; Table 1 Test results As shown in Table 1, the thermoelectric coolers prepared by the thermoelectric cooler preparation method in Examples 1 to 5 have a heat exchange frequency of 300,000 to 450,000 times when the resistance change rate reaches 5%, and the working life of the thermoelectric cooler is significantly increased.

[0042] No barrier metal is set in Comparative Example 1. The results show that the number of heat exchanges of the thermoelectric refrigerator in Comparative Example 1 when the resistance change rate reaches 5% is only 3000 times, which is significantly lower than the working life of the thermoelectric refrigerator prepared in Example 1. It can be seen from the results of Comparative Example 1 and Example 1 that the working life of the thermoelectric refrigerator prepared by the thermoelectric refrigerator preparation method provided by the present invention is 100 times the working life of the thermoelectric refrigerator without a barrier layer, and the service life is significantly improved.

[0043] In Comparative Example 2, no electroplating layer is provided. In actual operation, it is found that the conductive body and the semiconductor particles cannot be effectively welded, and thus the practical application cannot be performed.

[0044] In Comparative Example 3, aluminum is used as the fluid guide. The results show that the heat exchange times of the thermoelectric refrigerator of Comparative Example 3 when the resistance change rate reaches 5% are only 80,000 times, which is lower than the working life of the thermoelectric refrigerator prepared in the embodiment. After analysis, it is found that the initial resistance change rate of the thermoelectric refrigerator when aluminum is used as the fluid guide is higher than that of the copper fluid guide. Therefore, the working life of the thermoelectric refrigerator of the aluminum guide plate is lower than that of the thermoelectric refrigerator of the copper fluid guide of the present invention.

[0045] In Comparative Example 4, iron was selected as the barrier metal. The results showed that the heat exchange times of the thermoelectric refrigerator of Comparative Example 4 when the resistance change rate reached 5% were only 50,000 times, which was lower than the working life of the thermoelectric refrigerator made in the embodiment. After analysis, it was found that iron as a barrier metal would produce a potential barrier, which makes the initial resistance change rate of the thermoelectric refrigerator made of barrier metal higher than that of aluminum barrier metal. In addition, although the effects of titanium and tungsten are better than aluminum, the cost of aluminum is lower. Based on the premise of cost and effect, aluminum as a barrier metal is easier to apply to actual production and processing.

[0046] No stress groove is set in Comparative Example 5. The results show that the heat exchange times of the thermoelectric cooler in Comparative Example 5 when the resistance change rate reaches 5% are only 100,000 times, which is lower than the working life of the thermoelectric cooler prepared in the embodiment. The above results show that setting stress grooves on the conductor also has a certain effect on improving the working life of the thermoelectric cooler.

[0047] Comparative Examples 6 and 7 are technical solutions in which the barrier metal is too large or too small, respectively. The results show that if the thickness of the barrier metal is too large or too small, the working life of the thermoelectric cooler will be reduced.

[0048] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any way. Any simple modification, change and equivalent transformation made to the above embodiment based on the technical essence of the present invention still falls within the protection scope of the technical solution of the present invention.

Claims

1. A method for preparing a thermoelectric cooler, characterized in that: The following steps are involved: After the barrier metal is attached to the surface of the semiconductor particles, an electroplating layer is attached to form a pre-processed semiconductor, and the conductive body provided with solder paste is thermally compounded with the pre-processed semiconductor to form a thermoelectric cooler.

2. The preparation method according to claim 1, characterized in that: The thickness of the barrier metal is 1-30 μm, and the barrier metal is one or more of aluminum, titanium and tungsten.

3. The preparation method according to claim 1 or 2, characterized in that: The raw materials of the electroplating layer are one or both of nickel and tin.

4. The preparation method according to claim 1, characterized in that: The semiconductor particles are Bi2Te3.

5. The preparation method according to claim 1, characterized in that: The attachment method is sandblasting.

6. The preparation method according to claim 1, characterized in that: The conductor is copper.

7. The preparation method according to claim 1, characterized in that: The solder paste is printed on the surface of the body conductor.

8. A thermoelectric cooler, characterized in that: The invention comprises semiconductor particles (1) and a body conductor (2) welded on a welding surface of the semiconductor particles, a barrier metal layer (101) being provided on the welding surface of the semiconductor particles, an electroplating layer (102) being provided on the barrier metal layer, a solder paste layer (201) being provided on one side of the body conductor welded to the welding surface of the semiconductor particles, and a substrate (3) being provided on the other side of the body conductor, wherein the thermoelectric cooler is manufactured by the method for manufacturing a thermoelectric cooler according to any one of claims 1 to 7.

9. The thermoelectric cooler according to claim 8, characterized in that: A stress groove (202) is provided on the body guide, the stress groove is located on a side of the body guide provided with a solder paste layer, and no solder paste layer is provided in the stress groove.

10. The thermoelectric cooler according to claim 9, characterized in that: The stress groove is a vertical groove.

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