JP2002124707A - Method for manufacturing thermoelectric conversion module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a thermoelectric conversion module wherein adhesive strength between an electrode and a thermoelectric element is large, manufacturing is easy and production efficiency is superior. SOLUTION: In a method for manufacturing the thermoelectric conversion module, a bismuth-antimony-tellurium-selenium based thermoelectric semiconductor 1 consisting of a p-type thermoelectric semiconductor 1a having a bismuth- antimony-tellurium system and an N-type thermoelectric semiconductor 1b having a bismuth-tellurium system is formed. After a metal film 2 is formed on the surface of the thermoelectric semiconductor 1, at least one pair of P-type and N-type thermoelectric elements 3 which have the metal films 2 on end portions obtained by dicing are thermally bonded by soldering on prescribed positions on an insulating substrate 5 on which electrodes 4 are formed, so as to be electrically connected in series. After the so-called plasma treatment in which a voltage is applied to ionized particles obtained by applying energy to gas, and ions are made to collide against the surface of the thermoelectric element, the metal film 2 is formed by sputtering or vapor deposition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a thermoelectric conversion module, and more particularly, to a method for manufacturing a thermoelectric semiconductor of an alumina type module or a fixed type module having at least one pair of P-type and N-type thermoelectric semiconductors. A metal film with appropriate adhesion, heat resistance, and corrosion resistance can be formed. Compared to the metal film forming process by plating, it does not require many chemicals and the manufacturing process is simple and efficient. In a method for manufacturing a thermoelectric conversion module.

[0002]

2. Description of the Related Art A conventional method for manufacturing a thermoelectric conversion module is to form a P-type or N-type bismuth-antimony-tellurium-selenium-based thermoelectric semiconductor by forming a metal film on the surface and then cutting the same to form an edge. More than one pair of P type and N with metal film
Type thermoelectric elements, so that they are electrically in series,
In a method of manufacturing a thermoelectric conversion module which is joined by soldering to a predetermined position on an insulating substrate on which electrodes are formed, Japanese Patent Application Laid-Open No. 4-249385 discloses a plating (wet) method.
Discloses a method including a step of forming a metal film.

However, in this method, an appropriate adhesion between the metal film and the thermoelectric element cannot be obtained, and many chemical treatments are required.

To solve these problems, Japanese Patent Application Laid-Open No.
JP 190070 discloses that the method includes a step of forming a metal film on a thermoelectric element by sputtering or vapor deposition (dry method). In this method of forming a metal film on a thermoelectric element by a dry method, the diffusion layer formed for obtaining adhesion between the thermoelectric element and the diffusion prevention layer is a post-process because a metal having a low melting point and poor heat resistance is used. At the time of soldering or plating, there is a problem that the adhesion strength between the thermoelectric element and the metal film is reduced, and the performance of the thermoelectric conversion module is reduced.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and is intended to manufacture a thermoelectric conversion module having a high adhesion strength between an electrode and a thermoelectric element, which is easy to manufacture, and has good production efficiency. In the way.

[0006]

According to a first aspect of the present invention, there is provided a method for manufacturing a thermoelectric conversion module, comprising: forming a metal film on a surface of a P-type and N-type bismuth-antimony-tellurium-selenium-based thermoelectric semiconductor; By dividing, a pair or more of P-type and N-type thermoelectric elements having a metal film at an end are obtained, and soldered to a predetermined position on an insulating substrate on which electrodes are formed so that these are electrically connected in series. A method of manufacturing a thermoelectric conversion module, wherein the method includes a step of forming a metal film by sputtering or vapor deposition after plasma treatment on the surface of the thermoelectric semiconductor. .

[0007] Therefore, it is possible to form a metal film having an appropriate adhesion force on the thermoelectric element, heat resistance and corrosion resistance. Further, compared with the step of forming a metal film by plating, a large number of chemicals are not required, and the process is simple. Further, it becomes possible to form each layer continuously at the time of forming a metal film composed of many layers, and the production efficiency is improved.

According to a second aspect of the present invention, there is provided a method for manufacturing a thermoelectric conversion module, wherein a pair of thermoelectric elements comprising P-type and N-type bismuth-antimony-tellurium-selenium-based thermoelectric semiconductors are fixed with an insulating material and then fixed. In the method of manufacturing a thermoelectric conversion module, a circuit that is electrically connected in series is formed on the end face of the thermoelectric element, and after performing thickening by soldering or electroplating, an insulating substrate is laminated on the circuit forming surface. And a step of subjecting the fixed thermoelectric element end face to plasma treatment and then forming a metal film by sputtering or vapor deposition.

Therefore, it is possible to form a metal film having an appropriate adhesive force on the thermoelectric element, heat resistance and corrosion resistance. Further, compared with the step of forming a metal film by plating, a large number of chemicals are not required, and the process is simple. Further, it becomes possible to form each layer continuously at the time of forming a metal film composed of many layers, and the production efficiency is improved. Further, after forming a circuit on the thermoelectric element end face by sputtering or vapor deposition, electroplating is performed, so that a solderless electrode can be formed, and the heat resistance of the thermoelectric conversion module is improved.

According to a third aspect of the present invention, there is provided a method for manufacturing a thermoelectric conversion module according to the first or second aspect, wherein the surface of the thermoelectric element is subjected to a roughening treatment with a chemical before the plasma treatment. It is.

Therefore, the adhesion strength of the metal film is improved by the anchor effect by removing, activating and roughening the organic substances attached to the surface of the thermoelectric element of the thermoelectric conversion module.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a thermoelectric conversion module, wherein sulfuric acid is used as a roughening treatment for a P-type thermoelectric element, and a roughening treatment for an N-type thermoelectric element is performed. Is characterized by using hydrochloric acid.

Accordingly, the adhesion strength of the metal film is improved by the anchor effect due to the roughening of the surface of the P-type and N-type thermoelectric elements.

According to a sixth aspect of the present invention, there is provided a method of manufacturing a thermoelectric conversion module according to the first or second aspect, wherein the plasma treatment is performed in an argon atmosphere.

[0015] Therefore, since argon has a large sputtering rate, a larger surface roughening treatment can be obtained.

According to a seventh aspect of the present invention, there is provided a method of manufacturing a thermoelectric conversion module according to the sixth aspect.
Plasma treatment of the surface of the type thermoelectric element in an argon atmosphere,
The treatment time is 2 to 10 minutes at a pressure of 1 to 15 Pa and an output of 30 to 1000 W, and the plasma treatment of the surface of the N-type thermoelectric element is performed in an argon atmosphere at a pressure of 1 to 15 Pa and an output of 30 to 10 Pa.
The processing time is 4 to 20 minutes at 00W.

Therefore, the activation and roughening of the surface of the P-type and N-type thermoelectric elements improve the adhesion strength of the metal film.

According to a ninth aspect of the present invention, there is provided a method of manufacturing a thermoelectric conversion module according to the first or second aspect, wherein a metal piece having the same composition as a film-forming material is placed on the periphery of the thermoelectric element to perform plasma processing. That is.

Therefore, a film having a thickness of 5 μm or less can be formed on the thermoelectric element surface simultaneously with the etching of the thermoelectric element surface.

According to a tenth aspect of the present invention, there is provided a method of manufacturing a thermoelectric conversion module, wherein a thin metal film is formed on a metal piece according to the ninth aspect by sputtering or vapor deposition. Therefore, a thin film formed by sputtering or vapor deposition has a large sputtering rate, and the degree of film formation on a thermoelectric element is improved.

[0021] The method for manufacturing a thermoelectric conversion module according to claim 11 of the present invention is characterized in that in claim 1 or claim 2,
A solder diffusion preventing layer is formed on the surface of the thermoelectric element, and a solder wettability improving layer or a plating base layer is formed on the solder diffusion preventing layer.

Accordingly, the number of film formations is reduced and the manufacturing is simplified by performing the adhesion between the thermoelectric element and the metal film and the prevention of diffusion.

According to a twelfth aspect of the present invention, there is provided a method for manufacturing a thermoelectric conversion module according to the eleventh aspect, wherein Pt, Ni or an alloy thereof is 0.5 to 5 as a solder diffusion preventing layer.
a thickness of 0.3 μm and a metal made of at least one of Sn, Bi, Au, Ag, Pb and Cu as a solder wettability improving layer on the solder diffusion preventing layer to a thickness of 0.3 to 2 μm. Alternatively, Cu is formed in a thickness of 0.2 to 2 μm as a plating underlayer on the solder diffusion preventing layer.

Therefore, the diffusion of solder, the diffusion of Cu, the wettability of the metal film and the solder are improved, and the adhesion to the plating film is improved.

[0025] According to a thirteenth aspect of the present invention, a method for manufacturing a thermoelectric conversion module according to the first or second aspect is provided.
An adhesion layer for improving the adhesion between the thermoelectric element and the metal film is formed on the surface of the thermoelectric element, a solder diffusion preventing layer is formed on the adhesion layer, and a solder wettability improving layer or plating is further formed on the solder diffusion preventing layer. It is characterized by forming a stratum.
Therefore, by performing adhesion and prevention of diffusion between the thermoelectric element and the metal film using a different material, a material suitable for adhesion can be used as the adhesion layer, thereby improving the adhesion.

According to a fourteenth aspect of the present invention, there is provided a method for manufacturing a thermoelectric conversion module according to the thirteenth aspect, wherein a metal made of at least one of Ti, Mo, and Cr is used as the adhesion layer to a thickness of 0.01 to 0.5 μm. And a Pt, Ni or alloy thereof of 0.5 to 5 as a solder diffusion preventing layer.
A metal made of at least one of Sn, Bi, Au, Ag, Pb and Cu is formed on the solder diffusion preventing layer as a solder wettability improving layer to a thickness of 0.2 to 2 μm. It is characterized by the following.

Therefore, the adhesion between the thermoelectric element and the metal film is improved, the diffusion of solder is prevented, the diffusion of Cu is prevented, the wettability between the metal film and the solder is improved, and the adhesion between the plating film and the plating film is improved.

According to a fifteenth aspect of the present invention, there is provided a method of manufacturing a thermoelectric conversion module according to the twelfth or fourteenth aspect, wherein each composition of the metal film is inclined.

Therefore, the adhesion between the film forming layers is improved.

[0030] In the method for manufacturing a thermoelectric conversion module according to claim 16 of the present invention, the surface of the solder wettability improving layer is treated to prevent rust in claim 12 or 14.

Therefore, the solder wettability is improved, and the thickness of the solder wet layer can be made 0.05 to 0.3 μm.

[0032]

FIG. 1 shows a method for manufacturing a thermoelectric conversion module of, for example, an alumina type module according to the invention of claim 1 of the present invention, and FIG. 2 shows the method of manufacturing according to claim 2 of the present invention. For example, a method of manufacturing a thermoelectric conversion module of a fixed type module. These two types of thermoelectric conversion modules will be described below with reference to FIGS.

In FIG. 1, bismuth-antimony-tellurium-based and N-type thermoelectric semiconductors 1b are used as P-type thermoelectric semiconductors 1a.
After forming a metal film 2 on the surface of a bismuth-antimony-tellurium-selenium-based thermoelectric semiconductor 1 made of a bismuth-tellurium system, by cutting (dicing), a pair of P or more having the metal film 2 at an end portion is formed. Method of Manufacturing Thermoelectric Conversion Module by Obtaining Thermoelectric Elements 3 of N-Type and N-Type, and Heating and Joining to a Predetermined Position on Insulating Substrate 5 on Which Electrode 4 is Formed so as to Be Electrically Seriesed Includes a step of applying a voltage to particles ionized by applying energy to a gas to cause ions to collide with the surface of the thermoelectric semiconductor 1, that is, a step of forming a metal film 2 by sputtering or vapor deposition after so-called plasma processing. A method for manufacturing a thermoelectric conversion module, characterized in that:

This will be described in the process. When a voltage is applied to the ionized particles by applying energy to the gas to the surface of the bismuth-antimony-tellurium-selenium-based thermoelectric semiconductor 1, ions are applied to the surface of the thermoelectric semiconductor 1. After performing a so-called plasma process for causing collision, a metal film 2 is formed on the surface after the plasma process by sputtering or vapor deposition. Then, the formed thermoelectric semiconductor 1 is cut (diced) to obtain a pair or more of P-type and N-type thermoelectric elements 3 having a metal film 2 at an end portion, and these are electrically connected in series. The electrode is mounted at a predetermined position on the insulating substrate 5 on which the electrode 4 is formed, and then the thermoelectric element 3 and the electrode 4 are heated and joined by soldering to manufacture a thermoelectric conversion module.

As described above, by performing the plasma processing, it is possible to form the metal film 2 having an appropriate adhesive force on the thermoelectric element 3 and having excellent heat resistance and corrosion resistance. Also, unlike the conventional plating method, a large number of chemicals are not required, so that the process is simplified. Further, it becomes possible to continuously form a metal film composed of many layers, and the production efficiency is improved.

In FIG. 2, bismuth-antimony-tellurium-based and N-type thermoelectric semiconductors 1b are used as P-type thermoelectric semiconductors 1a.
A pair of at least one rod-shaped thermoelectric element 3 made of a bismuth-antimony-tellurium-selenium-based thermoelectric semiconductor 1 made of bismuth-tellurium is fixed and integrated with an insulating material such as resin, and the end face of the fixed thermoelectric element 3 A thermoelectric conversion module is formed by forming a circuit 6 that is electrically connected in series, performing soldering or electroplating, and then laminating an insulating substrate 5 on a surface on which the circuit is to be formed and heating and joining the same. The method for producing a thermoelectric conversion module includes a step of forming the metal film 2 by sputtering or vapor deposition after subjecting the end face of the fixed thermoelectric element 3 to plasma treatment as in FIG. 1 in the production method. .

This will be described in the process. A pair of extruded rod-shaped thermoelectric elements 3 composed of a bismuth-antimony-tellurium-selenium-based thermoelectric semiconductor 1 are fixed with an insulating material such as resin and integrated into a plate. After that, a so-called plasma treatment, in which ions are made to collide with the surface of the thermoelectric semiconductor 1 by applying a voltage to the ionized particles by applying energy to the gas on the surface of the thermoelectric element 3 fixed in a plate shape, Then, a metal film 2 is formed on the surface after the plasma treatment by sputtering or vapor deposition. After that, a circuit 6 that is electrically connected in series is formed, and after thickening is performed by soldering or electroplating, an insulating substrate 5 having an electrode 4 is laminated on a circuit forming surface to form a thermoelectric element 3 and an electrode. And 4 are heated and joined by soldering to manufacture a thermoelectric conversion module.

As described above, by performing the plasma treatment, it is possible to form the metal film 2 having an appropriate adhesive force on the thermoelectric element 3 and having excellent heat resistance and corrosion resistance. Also, unlike the conventional plating method, a large number of chemicals are not required, so that the process is simplified. Further, it becomes possible to continuously form a metal film composed of many layers, and the production efficiency is improved. Furthermore, after a circuit is formed at the end of the thermoelectric element 3 by sputtering or vapor deposition, electroplating is performed, so that a solderless electrode can be formed.

In the method of manufacturing the thermoelectric conversion module shown in FIGS. 1 and 2 described above, the surface of the thermoelectric element 3 is cleaned by ultrasonic cleaning or the like before performing the plasma treatment as shown in FIG.
The surface of the thermoelectric element 3 is roughened by contacting a chemical such as hydrochloric acid or sulfuric acid. By roughening the surface of the thermoelectric element 3 in this manner, the anchor effect is increased, and the adhesion strength of the metal film 2 is improved. At this time, sulfuric acid is used as a roughening treatment for the P-type thermoelectric element, and hydrochloric acid is used as a roughening treatment for the N-type thermoelectric element. The cleaning step of the P-type and N-type thermoelectric elements by ultrasonic cleaning or the like may be performed if necessary, and is not an essential component.

(Embodiment) A P-type thermoelectric element was subjected to ultrasonic cleaning in ethanol, and then the concentration was 20 ml / L as a chemical solution.
The solution was immersed in sulfuric acid at a liquid temperature of 18 to 23 ° C. for 5 minutes. As a result, the adhesion of the metal film was improved by the anchor effect due to the roughening of the surface of the P-type thermoelectric element. Then, hydrochloric acid is used as a surface roughening treatment of the N-type thermoelectric element. After ultrasonic cleaning of the N-type thermoelectric element in ethanol, sulfuric acid having a concentration of 60 ml / L was used as a chemical solution, and the solution temperature was 18 to
It was immersed at 23 ° C. for 5 minutes. As a result, the adhesion of the metal film was improved by the anchor effect due to the roughening of the surface of the N-type thermoelectric element.

Hereinafter, the above-described plasma processing method will be described. It is best to perform the plasma treatment in an argon atmosphere. Because, when comparing the sputtering rates of argon ions and helium ions, argon ions are 1.3,
Helium ions: 0.13, and argon ions have a greater atomic weight than helium ions, and the number of atoms that evaporate per ion (sputter rate) when colliding with the solid surface is large, resulting in a larger roughness. The surface effect can be obtained. In addition, since the surface can be roughened in a short time, production efficiency is increased. At this time, if the plasma treatment of the surface of the P-type thermoelectric element 1a is performed in an argon atmosphere at a pressure of 1 to 15 Pa and an output of 30 to 1000 W, the base material strength becomes 10 M
At least 2 minutes to 10 minutes as shown in FIG. 12 to have an adhesion strength comparable to that of Pa, activation and roughening of the surface of the P-type thermoelectric element 3 are completed, and the adhesion strength of the metal film 2 is improved. . The surface of the N-type thermoelectric element 1b is plasma-treated in an argon atmosphere at a pressure of 1 to 15 Pa and an output of 30 to 10 Pa.
When performed at 00 W, the activation and roughening of the surface of the N-type thermoelectric element 3 are completed by performing the processing time of 4 to 20 minutes at a minimum, as can be seen from FIG. 13, in order to have an adhesion strength similar to the base material strength of 10 MPa. Thus, the adhesion strength of the metal film 2 is improved.

FIG. 4 is a diagram showing a sputtering model.
Argon gas is released from the gas inlet 8 into the vacuum vessel 7, discharge plasma is discharged to the substrate 9 for attaching the metal film 2, and then the metal film 2 is formed by sputtering or vapor deposition. I have. At this time, the thermoelectric element 3
A metal piece 10 having the same composition as that of the film-forming material is installed on the periphery of. Substrate 9 for attaching metal film 2
In the enlarged cross-sectional view, the thermoelectric element 3 is attached to the lower stainless steel jig 12 on the upper stainless steel jig 11.
And platinum under the lower stainless steel jig 12,
A metal piece 10 such as nickel is provided with a radius of 0.degree.
Arranged and fixed within 2 m. Therefore, argon ions collide with the thermoelectric element 3, and a film of 5 μm or less can be formed on the surface of the thermoelectric element 3 simultaneously with the etching of the thermoelectric element 3.

FIG. 5 shows a modified embodiment of FIG. 4, in which the thermoelectric element 3 is held between a lower stainless steel jig 12 and a lower stainless steel jig 12 by an upper stainless steel jig 11. 12 is obtained by subjecting platinum, nickel, or the like to plasma treatment using a metal piece 10 in which a thin film is formed by sputtering or vapor deposition. Therefore, the sputtering rate of the thin film formed by sputtering or vapor deposition is increased, and the deposition rate on the thermoelectric element 3 is improved.

Further, in the alumina type module shown in FIG. 1, a solder diffusion preventing layer 13 is formed on the surface of the thermoelectric element 3 as shown in FIGS. 6 (a), 6 (b) and 6 (c). In this embodiment, a solder wettability improving layer 14 or a plating base layer 15 is formed on the diffusion preventing layer 13. Looking at this in an enlarged view (c), a solder 17 is formed on the lower surface of the electrode 4, a solder wettability improving layer 14 is formed on the lower surface of the solder 17, and a solder diffusion preventing layer is formed under the solder wettability improving layer 14. 13 are formed and joined to the upper surface of the thermoelectric element 3. At this time, a plating base layer 15 may be formed instead of the solder wettability improving layer 14.

In the fixed type module shown in FIG. 2, as shown in FIGS. 7 (a), (b) and (c),
The solder diffusion preventing layer 13 is formed on the surface of the thermoelectric element 3, and the solder wettability improving layer 14 or the plating base layer 15 is formed on the solder diffusion preventing layer 13. This is an enlarged view (c)
As shown in FIG. 2, a solder 17 is formed on the lower surface of the electrode 4, a solder wettability improving layer 14 is formed on the lower surface of the solder 17, and a solder diffusion preventing layer 13 is formed under the solder wettability improving layer 14.
It is joined to the upper surface of the thermoelectric element 3. At this time, a plating base layer 15 may be formed instead of the solder wettability improving layer 14. The P-type thermoelectric semiconductor 1a and the N-type thermoelectric semiconductor 1b are fixed with an insulating material 16 such as a resin.

As described above, since the adhesion between the thermoelectric element 3 and the metal film 2 and the prevention of diffusion are performed by a single layer, the number of formed films is reduced and the manufacturing is simplified. At this time, Pt, Ni or an alloy thereof is formed to a thickness of 0.5 to 5 μm as the solder diffusion preventing layer 13, and Sn, Bi, Au, A metal made of at least one of Ag, Pb, and Cu is formed to a thickness of 0.3 to 2 μm, or Cu is formed to a thickness of 0.2 to 2 μm as a plating underlayer 15 on the solder diffusion preventing layer 13. By doing so, Pt and Ni react with the Sn-based solder to form an intermetallic compound, so that the adhesion between the metal film 2 and the solder 17 is obtained, and since the reaction speed is slow, the effect of preventing the diffusion of the solder 17 is obtained. Can be Further, Pt and Ni react with Cu, which is the plating underlayer 15, to form an intermetallic compound, so that the adhesion between the film-forming layers is obtained, and the reaction speed is low, so that the Cu diffusion preventing effect is obtained. And Sn, Bi, Au, A
By dissolving g, Pb, and Cu in the Sn-based solder or forming an Sn-based solder component and an intermetallic compound, the wettability between the metal film 2 and the solder 17 is improved. Further, since the oxide film of Cu can be easily removed by pickling, which is a pretreatment for plating, the adhesion to the plating film is improved.

In the alumina type module and the fixed type module shown in FIGS. 1 and 2, FIGS. 8 and 9 are provided below with an adhesion layer provided.

In FIG. 8, an adhesion layer 18 for improving the adhesion between the thermoelectric element 3 and the metal film 2 is formed on the surface of the thermoelectric element 3, and a solder diffusion preventing layer 13 is formed on the adhesion layer 18. On the solder diffusion preventing layer 13, a solder wettability improving layer 14 or a plating base layer 15 is formed.
The solder 17 is applied to the lower surface of the electrode 4 according to the enlarged view.
A solder diffusion preventing layer 13 is formed on the lower surface of the solder wettability improving layer 14,
An adhesion layer 18 is formed on the lower surface of the solder diffusion preventing layer 13, and the adhesion layer 18 is joined to the surface of the thermoelectric element 3.

In FIG. 9, an adhesion layer 18 for improving the adhesion between the thermoelectric element 3 and the metal film 2 is formed on the surface of the thermoelectric element 3, and a solder diffusion preventing layer 13 is formed on the adhesion layer 18. On the solder diffusion preventing layer 13, a solder wettability improving layer 14 or a plating base layer 15 is formed.
The solder 17 is applied to the lower surface of the electrode 4 according to the enlarged view.
A solder diffusion preventing layer 13 is formed on the lower surface of the solder wettability improving layer 14,
An adhesion layer 18 is formed on the lower surface of the solder diffusion preventing layer 13, and the adhesion layer 18 is joined to the surface of the thermoelectric element 3.
The P-type thermoelectric semiconductor 1a and the N-type thermoelectric semiconductor 1b are fixed with an insulating material 16 such as a resin.

Therefore, by using different materials for the adhesion layer 18 of the thermoelectric element 3, the metal film 2, and the solder diffusion preventing layer 13,
Since a material suitable for adhesion can be applied as the adhesion layer 18,
The adhesion is improved. At this time, Ti,
A metal consisting of at least one of Mo and Cr is added to a metal.
The solder diffusion preventing layer 13 is formed to a thickness of
Pt, Ni or an alloy thereof is 0.5 to 5 μm
Of Sn, Bi, Au, Ag, Pb, and Cu as the solder wettability improving layer 14 on the solder diffusion preventing layer 13.
0.2 to 2 μm of at least one kind of metal
It is formed in the thickness of.

The solder diffusion preventing layer 13 defines a solder or plating material diffusion preventing layer.

Therefore, Ti, Mo, and Cr are active metals, and the adhesion between the thermoelectric element 3 and the metal film 2 is improved.
Further, Pt and Ni react with the Sn-based solder 17 to obtain an adhesive force between the metal film 2 and the solder 17 for forming an intermetallic compound, and the reaction speed is slow, so that an effect of preventing diffusion of the solder is obtained. Can be Further, Pt and Ni react with Cu as the plating underlayer 15 to form an intermetallic compound, so that adhesion between the film-forming layers is obtained, and the reaction speed is low, so that an effect of preventing Cu diffusion is obtained. And Sn, Bi, Au, A
By dissolving g, Pb, and Cu in the Sn-based solder, or by forming an intermetallic compound with the Sn-based solder component, the wettability between the metal film 2 and the solder 17 is improved. Further, Cu can easily remove the oxide film on the surface by pickling, which is a pre-plating treatment, so that the adhesion to the plating film is improved.

FIG. 10 shows that the composition of the metal film is inclined to improve the adhesion of each film formation layer. Solder 17 is applied to the lower surface of the electrode 4, and Pt and Ni react with the Sn-based solder 17 on the lower surface of the solder 17, and the adhesion between the metal film 2 and the solder 17 for forming an intermetallic compound is obtained. Further, Pt and Ni react with Cu, which is the plating underlayer 15, to form an intermetallic compound, so that adhesion between the film-forming layers is obtained, and Sn, Bi, Au, Ag, P
b and Cu are dissolved in Sn-based solder, or
By forming the intermetallic compound with the system solder component, the wettability between the metal film 2 and the solder 17 is improved. Furthermore, Cu
Since the oxide film on the surface can be easily removed by pickling, which is a pre-plating treatment, the adhesion to the plating film is improved.

FIG. 11 shows a process for rust-proofing the surface of the solder wettability improving layer 14. The metal film 2 is formed by sputtering after plasma treatment, and then a rosin-based flux is sprayed or melt-coated by spraying. Rust prevention treatment. By this rust prevention treatment, the solder wettability is improved, the thickness of the solder wet layer can be made 0.05 to 0.3 μm, and the adhesion to the plating film is further improved.

[0055]

As described above, the method for manufacturing a thermoelectric conversion module according to the first aspect of the present invention is based on the P-type and N-type bismuth
After a metal film is formed on the surface of the antimony-tellurium-selenium-based thermoelectric semiconductor, it is divided to obtain a pair or more of P-type and N-type thermoelectric elements having a metal film at an end, and these are electrically connected. In a method for manufacturing a thermoelectric conversion module, which is joined by soldering to a predetermined position on an insulating substrate on which electrodes are formed so as to be in series, a metal film is formed by sputtering or vapor deposition after plasma treatment on the thermoelectric semiconductor surface Since the method includes a step of forming a metal film, the metal film can be formed with an appropriate adhesive force on the thermoelectric element and with heat resistance and corrosion resistance. Also, compared to the process of forming a metal film by plating,
Many chemical solutions are not required, and the process is simple. further,
When forming a metal film composed of a large number of layers, each layer can be formed continuously, and the production efficiency is improved.

In the method for manufacturing a thermoelectric conversion module according to the second aspect of the present invention, a pair of thermoelectric elements composed of P-type and N-type bismuth-antimony-tellurium-selenium-based thermoelectric semiconductors are fixed with an insulating material and then fixed. In the method of manufacturing a thermoelectric conversion module, a circuit that is electrically connected in series is formed on the end face of the thermoelectric element, and after performing thickening by soldering or electroplating, an insulating substrate is laminated on the circuit forming surface. After the plasma treatment of the fixed thermoelectric element end face, the method includes a step of forming a metal film by sputtering or vapor deposition, so that the thermoelectric element has an appropriate adhesion, heat resistance, corrosion resistance of the metal film. Film formation becomes possible. Further, compared with the step of forming a metal film by plating, a large number of chemicals are not required, and the process is simple. Further, it becomes possible to form each layer continuously at the time of forming a metal film composed of many layers, and the production efficiency is improved. In addition, since a circuit is formed on the thermoelectric element end by sputtering or vapor deposition, electroplating is performed, so that a solderless electrode can be formed, and the heat resistance of the thermoelectric conversion module is improved.

According to a third aspect of the present invention, there is provided a method for manufacturing a thermoelectric conversion module, wherein the surface of the thermoelectric element is subjected to a surface roughening treatment with a chemical before plasma treatment, thereby removing organic substances attached to the thermoelectric element surface of the thermoelectric conversion module. The adhesion strength of the metal film is improved by the anchor effect due to activation and roughening.

According to a fourth aspect of the present invention, there is provided a method for manufacturing a thermoelectric conversion module, wherein sulfuric acid is used as a roughening treatment for a P-type thermoelectric element, and a roughening treatment for an N-type thermoelectric element is performed. By using hydrochloric acid, the adhesion strength of the metal film is improved by the anchor effect due to the surface roughening of the P-type and N-type thermoelectric elements.

In the method of manufacturing a thermoelectric conversion module according to the sixth aspect of the present invention, since the plasma treatment is performed in an argon atmosphere, a larger surface roughening treatment can be obtained because the sputtering rate is high.

In the method for manufacturing a thermoelectric conversion module according to the seventh and eighth aspects of the present invention, the plasma treatment of the surface of the P-type thermoelectric element is performed in an argon atmosphere at a pressure of 1 to 15 Pa, an output of 30 to 1000 W and a processing time of 2 hours. Performing plasma treatment on the surface of the N-type thermoelectric element in an argon atmosphere at a pressure of 1 to 15 Pa and an output of 30 to 1000 W for 4 to 10 minutes.
This is performed for 20 minutes, and the adhesion strength of the metal film is improved by activating and roughening the surface of the P-type and N-type thermoelectric elements.

In the method for manufacturing a thermoelectric conversion module according to the ninth aspect of the present invention, a metal piece having the same composition as the film-forming material is placed on the periphery of the thermoelectric element and plasma treatment is performed. A film having a thickness of 5 μm or less can be formed on the element surface.

In the method for manufacturing a thermoelectric conversion module according to the tenth aspect of the present invention, a thin film formed by sputtering or vapor deposition on a metal piece is used. Therefore, the thin film has a large sputtering rate and is formed on a thermoelectric element. The degree improves.

In the method for manufacturing a thermoelectric conversion module according to the eleventh aspect of the present invention, a solder diffusion preventing layer is formed on a thermoelectric element surface, and a solder wettability improving layer or a plating base layer is formed on the solder diffusion preventing layer. Therefore, by performing adhesion and preventing diffusion between the thermoelectric element and the metal film of the metal film, the number of formed films is reduced, and the manufacturing is simplified.

According to a method of manufacturing a thermoelectric conversion module according to a twelfth aspect of the present invention, Pt, Ni or an alloy thereof is formed to a thickness of 0.5 to 5 μm as a solder diffusion preventing layer, and is formed on the solder diffusion preventing layer. As a solder wettability improving layer, Sn, Bi,
A metal made of at least one of Au, Ag, Pb, and Cu is formed to a thickness of 0.3 to 2 μm, or Cu is formed to a plating underlayer of 0.2 to 2 μm on the solder diffusion preventing layer.
m to prevent solder diffusion, Cu
And the wettability between the metal film and the solder is improved, and the adhesion to the plating film is improved.

According to the method for manufacturing a thermoelectric conversion module according to the thirteenth aspect of the present invention, an adhesion layer for improving the adhesion between the thermoelectric element and the metal film is formed on the surface of the thermoelectric element, and a solder diffusion preventing layer is formed on the adhesion layer. Further, since a solder wettability improving layer or a plating base layer is formed on the solder diffusion preventing layer,
By performing adhesion and diffusion prevention between the thermoelectric element and the metal film using different materials, a material suitable for adhesion can be used as the adhesion layer, so that the adhesion is improved.

In the method for manufacturing a thermoelectric conversion module according to claim 14 of the present invention, as the adhesion layer, a metal made of at least one of Ti, Mo, and Cr is used in an amount of 0.01 to 0.5 μm.
, Pt, Ni or an alloy thereof is formed to a thickness of 0.5 to 5 μm as a solder diffusion preventing layer, and Sn, Bi, and Sn are formed on the solder diffusion preventing layer as a solder wettability improving layer.
Since at least one metal of Au, Ag, Pb, and Cu is formed to a thickness of 0.2 to 2 μm, the adhesion between the thermoelectric element and the metal film is improved, the effect of preventing solder diffusion,
The effect of preventing the diffusion of Cu, the wettability between the metal film and the solder, and the adhesion between the plating film and the metal film are improved.

In the method for manufacturing a thermoelectric conversion module according to the fifteenth aspect of the present invention, the adhesion between the film forming layers is improved by inclining each composition of the metal film.

In the method for manufacturing a thermoelectric conversion module according to the present invention, the surface of the solder wettability improving layer is subjected to rust prevention treatment, so that the solder wettability is improved and the thickness of the solder wettability layer is reduced to 0.05. To 0.3 μm.

[Brief description of the drawings]

FIG. 1 is a schematic view of a process showing one embodiment of a method for manufacturing a thermoelectric conversion module of the present invention.

FIG. 2 is a schematic view of a process showing a different embodiment of the method for manufacturing a thermoelectric conversion module of the present invention.

FIG. 3 is a cross-sectional view of a thermoelectric element showing a step before the plasma processing of the present invention.

FIG. 4 is a sectional view of a main part of an embodiment of the sputtering model of the present invention.

FIG. 5 is a sectional view of a main part of a different embodiment of the sputtering model of the present invention.

FIG. 6 shows a thermoelectric conversion module according to the present invention, wherein (a)
1 is a perspective view of an alumina type module, (b) is a longitudinal sectional view of a main part, and (c) is an enlarged sectional view of a square part A of (b).

FIG. 7 shows a thermoelectric conversion module according to the present invention, wherein (a)
Is a perspective view of a fixed type module, (b) is a vertical cross-sectional view of a main part, and (c) is an enlarged cross-sectional view of a square portion B of (b).

FIG. 8 is a vertical cross-sectional view of a main part of the thermoelectric conversion module of the alumina type module of the present invention, in which an adhesion layer is provided.

FIG. 9 is a vertical cross-sectional view of a main part of the thermoelectric conversion module of the fixed type module of the present invention, in which an adhesion layer is provided.

FIG. 10 is a vertical sectional view of a main part of a thermoelectric conversion module of an alumina type module according to the present invention.

FIG. 11 is a vertical cross-sectional view of a main part of the thermoelectric conversion module according to the present invention, showing a state where a rust prevention process is performed after a metal film is formed.

FIG. 12 is a graph showing plasma treatment time and adhesion strength of a P-type thermoelectric element of the present invention.

FIG. 13 is a graph showing plasma treatment time and adhesion strength of the N-type thermoelectric element of the present invention.

[Explanation of symbols]

 1a P-type thermoelectric semiconductor 1b N-type thermoelectric semiconductor 2 Metal film 3 Thermoelectric element 4 Electrode 5 Insulating substrate 6 Circuit 7 Vacuum container 8 Gas inlet 9 Substrate 10 Metal piece 11 Jig 12 Jig 13 Solder diffusion prevention layer 14 Solder wettability Enhancement layer 15 Plating underlayer 16 Insulation material 17 Solder 18 Adhesion layer

Claims (16)

[Claims] 1. A metal film is formed on the surface of a P-type and N-type bismuth-antimony-tellurium-selenium-based thermoelectric semiconductor and then cut to form a pair of at least one P-type and N-type metal film at the ends. In a thermoelectric conversion module, wherein the thermoelectric elements are joined in a predetermined position on an insulating substrate on which electrodes are formed by soldering so that the thermoelectric elements are electrically connected in series. A process of forming a metal film by sputtering or vapor deposition after plasma treatment. 2. A thermoelectric element comprising a pair of P-type and N-type bismuth-antimony-tellurium-selenium-based thermoelectric semiconductors fixed with an insulating material, and then electrically connected in series to the fixed end faces of the thermoelectric elements. After forming a circuit, after performing thickening by soldering or electroplating, in the method of manufacturing a thermoelectric conversion module by laminating an insulating substrate on the circuit forming surface, after performing plasma processing on the thermoelectric element end face that is fixed, A method for manufacturing a thermoelectric conversion module, comprising a step of forming a metal film by sputtering or vapor deposition. 3. The method for manufacturing a thermoelectric conversion module according to claim 1, wherein the surface of the thermoelectric element is subjected to a surface roughening treatment with a chemical before the plasma treatment. 4. The roughening treatment of the P-type thermoelectric element,
The method for manufacturing a thermoelectric conversion module according to claim 3, wherein sulfuric acid is used. 5. The roughening treatment of the N-type thermoelectric element,
The method for producing a thermoelectric conversion module according to claim 3, wherein hydrochloric acid is used. 6. The method for manufacturing a thermoelectric conversion module according to claim 1, wherein the plasma processing is performed in an argon atmosphere. 7. The plasma treatment of the surface of the P-type thermoelectric element is performed in an argon atmosphere at a pressure of 1 to 15 Pa and an output of 30 to 1 Pa.
The method for producing a thermoelectric conversion module according to claim 6, wherein the treatment time is 2 to 10 minutes at 000W. 8. The plasma treatment of the surface of the N-type thermoelectric element is performed in an argon atmosphere at a pressure of 1 to 15 Pa and an output of 30 to 1 Pa.
The method for manufacturing a thermoelectric conversion module according to claim 6, wherein the treatment is performed at 000 W for 4 to 20 minutes. 9. The method for manufacturing a thermoelectric conversion module according to claim 1, wherein the plasma treatment is performed by placing a metal piece having the same composition as the film forming material on the periphery of the thermoelectric element. 10. The method for manufacturing a thermoelectric conversion module according to claim 9, wherein said metal piece is a metal piece having a thin film formed by sputtering or vapor deposition. 11. The solder diffusion preventing layer is formed on the surface of the thermoelectric element, and a solder wettability improving layer or a plating base layer is formed on the solder diffusion preventing layer. Method for manufacturing a thermoelectric conversion module. 12. The method according to claim 12, wherein the solder diffusion preventing layer is made of Pt, N
i or an alloy thereof is formed to a thickness of 0.5 to 5 μm,
Sn, B as a solder wettability improving layer on the solder diffusion preventing layer
A metal made of at least one of i, Au, Ag, Pb, and Cu is formed in a thickness of 0.3 to 2 μm, or Cu is used as a plating underlayer on a solder diffusion preventing layer in a thickness of 0.2 to 2 μm.
The method for manufacturing a thermoelectric conversion module according to claim 11, wherein the module is formed to have a thickness of 2 µm. 13. An adhesion layer for improving the adhesion between the thermoelectric element and the metal film is formed on the surface of the thermoelectric element, a solder diffusion preventing layer is formed on the adhesion layer, and a solder wetting is formed on the solder diffusion preventing layer. The method for manufacturing a thermoelectric conversion module according to claim 1, wherein a property improving layer or a plating base layer is formed. 14. A method according to claim 1, wherein the adhesion layer comprises a metal of at least one of Ti, Mo and Cr in an amount of 0.01 to 0.5.
of Pt, N as a solder diffusion preventing layer.
i or an alloy thereof is formed to a thickness of 0.5 to 5 μm,
Sn, B as a solder wettability improving layer on the solder diffusion preventing layer
14. The method for manufacturing a thermoelectric conversion module according to claim 13, wherein a metal made of at least one of i, Au, Ag, Pb, and Cu is formed to a thickness of 0.2 to 2 [mu] m. 15. The method for manufacturing a thermoelectric conversion module according to claim 12, wherein each composition of said metal film is inclined. 16. The method for manufacturing a thermoelectric conversion module according to claim 12, wherein the surface of the solder wettability improving layer is subjected to rust prevention treatment.