KR100842152B1 - Thermoelectric thin film module formed by electroplating and its manufacturing method - Google Patents

Abstract

The present invention provides a thermoelectric thin film module composed of a bismuth fluoride p-type thermoelectric thin film device and an n-type thermoelectric thin film device, and a method of manufacturing the same. More specifically, by adjusting the plating current density in the same electroplating solution, The present invention provides a thermoelectric thin film module formed by electroplating p-type thermoelectric thin film elements having different compositions and n-type thermoelectric thin film elements, and a method of manufacturing the same.

According to the present invention, p-type thermoelectric thin film elements having different compositions and n-type thermoelectric thin film elements are formed by electroplating in one plating solution, whereby miniaturized bismuth fluoride-based thermoelectric thin film modules can be formed at a high process speed and a low process cost. There is a process advantage.

Description

Thin Film Thermoelectric Module Processed Using Electroplating and the Fabrication Methods of the Same

1 is a schematic diagram of a conventional thermoelectric module.

Figure 2 is a schematic diagram of a thermoelectric thin film module composed of a p-type thermoelectric thin film element and an n-type thermoelectric thin film element formed by the electroplating method in the same plating solution according to the present invention.

3 is a schematic view showing the process flow of the thermoelectric thin film module formed by using the electroplating method according to the present invention and the cross-sectional view of each process step. FIG. 3 (a) is a schematic view showing the electroplating seed layer formed on the substrate. Fig. 3 (b) is a schematic diagram and cross-sectional schematic diagram of a photoresist pattern formed on a substrate. Fig. 3 (c) is a schematic diagram and cross-sectional schematic diagram of a p-type thermoelectric thin film element formed by electroplating. A schematic diagram and a cross-sectional schematic diagram of an electroplating n-type thermoelectric thin film element in a plating solution, FIG. 3 (e) is a schematic diagram and a cross-sectional schematic diagram with a photoresist pattern removed, and FIG. 3 (f) shows a p-type thermoelectric thin film element and an n-type thermoelectric element. Schematic diagram in which a high temperature end electrode and a low temperature end electrode are formed on a thin film element. .

* Explanation of Signs of Major Parts of Drawings *

11.p type thermoelectric element 12.n type thermoelectric element

13. High temperature end electrode 14. Low temperature end electrode

15. Substrate

21.p type thermoelectric thin film element 22.n type thermoelectric thin film element

23. Substrate 24. High Temperature End Electrode

25. Low Temperature Electrode

31. Seed layer for electroplating 32. Photoresist

Non-contact temperature sensor is a sensor that detects temperature by converting radiant signal such as infrared rays emitted from an object into thermal energy and converting it into electrical energy again to electric energy. It is used for various applications such as home appliances, office automation, crime prevention, disaster prevention, traffic and building systems. It is widely applied in the field. Non-contact infrared sensors are classified into quantum type and thermal type according to a method of converting thermal energy into electrical energy.

The dual quantum type has advantages of excellent sensitivity and responsiveness by using photoconductivity or photovoltaic effect, but it is difficult to miniaturize and limited in use because a refrigerant for cooling the device to a temperature of 80K or less is required. On the other hand, a thermal infrared sensor using a pyroelectric element or a thermopile is generally used as a general-purpose temperature sensor because it can be manufactured in a small size without requiring cooling.

Among the thermal infrared sensors, the pyroelectric infrared sensor responds to an input that changes like a moving object, but does not respond to an object that does not move. Therefore, a chopper must be used to periodically interrupt an input signal. Therefore, the pyroelectric infrared sensor requires a chopper and a driving motor thereof, and thus, there is a problem in that the structure is complicated, the power consumption is large, and the miniaturization is difficult. In contrast, the thermopile type infrared sensor uses Seebeck, which generates voltage due to a temperature difference, and can be measured without a separate device such as a chopper and a driving motor even when there is no movement of a measuring object.

로 표현된다. 현재 n형 실리콘(Si)이 써모파일형 적외선 센서를 구성하는 재료로 주로 사용되고 있으나, 지벡 계수가 낮기 때문에 출력되는 전기신호가 미약하여 응답감도가 낮다는 단점이 있다.The maximum output (P _max ) of the thermopile infrared sensor is proportional to the square of the Seebeck coefficient α of the thermopile, inversely proportional to the electrical resistance R, and is proportional to the square of the temperature difference ΔT between the hot and cold ends. Expressed as a formula, P _max =

It is expressed as Currently, n-type silicon (Si) is mainly used as a material for forming a thermopile-type infrared sensor, but since the Seebeck coefficient is low, the output electrical signal is weak and the response sensitivity is low.

Therefore, in order to improve the output characteristics of the thermopile type infrared sensor, thermoelectric modules using thermoelectric materials having excellent performance index at room temperature should be formed, and they should be connected in series electrically and in parallel.

As a material for constructing a thermoelectric module, a Bi ₂ Te ₃ -based thermoelectric material having a high Seebeck coefficient and a high performance index near room temperature is suitable. Bi ₂ Te _3- based p-type thermoelectric materials include p-type Bi ₂ Te ₃ and Bi ₂ Te ₃ in solid solution of Sb ₂ Te ₃ (Bi _{1 - x} Sb _x ) ₂ Te ₃ , and Bi ₂ Te ₃ -based n-type thermoelectric material to have a Bi ₂ Te ₃ Bi ₂ Se ₃ employs a Bi ₂ embodied with the n-type Bi ₂ Te _{3 -} a (Te _{1 y} Se _{y) 3} is used.

In the thermoelectric module, as shown in FIG. 1, the p-type thermoelectric element 11 and the n-type thermoelectric element 12 are electrically connected in series, and are thermally connected in parallel. As shown in FIG. 1, as the heat moves from the hot end to the cold end by the temperature difference between the hot end T _h and the low end T _c of the thermoelectric module, the p-type thermoelectric element 11 and n Holes and electrons in the thermoelectric element 12 are moved from the high end to the low end, so electromotive force is generated by the Seebeck effect.

The thermoelectric module using the Bi ₂ Te ₃ -based thermoelectric material of the shape shown in FIG. 1 has a bulk p-type thermoelectric element 11 and n-type thermoelectric element 12 prepared by cutting a single crystal ingot. Or p-type thermoelectric element 11 and n-type thermoelectric element 12 in the form of a bulk formed by cutting a polycrystalline pressurized body or a hot-extruded body manufactured by a pressure sintering method or a hot extrusion method. Has been. However, these agglomerated p-type thermoelectric elements 11 and n-type thermoelectric elements 12 are limited to the size reduction of thermoelectric elements because they are manufactured by cutting single crystal ingots or cutting polycrystalline pressurized bodies or hot extrusion bodies. All. Therefore, it is difficult to manufacture small thermoelectric modules using them, and thus there is a difficulty in constructing a small thermopile type infrared sensor.

Bi ₂ Te ₃ -type p-type thermoelectric thin film device manufactured by flash evaporation or magnetron sputtering to solve the problems of the thermoelectric module composed of the above-described lumped thermoelectric elements 11 and 12 and n A thermoelectric thin film module composed of thermoelectric thin film elements has been developed. The thermoelectric thin film elements constituting the thermoelectric thin film module can be made much finer than the conventional lumped thermoelectric elements. Therefore, the size of the thermoelectric thin film module can be made very small compared to the existing thermoelectric module, thereby miniaturizing the thermopile type infrared sensor configured using the thermoelectric thin film module.

However, the manufacturing process of the thermoelectric thin film module using the flash deposition method or the magnetron sputtering method is expensive because the cost of vacuum deposition equipment is expensive, and it takes a long time to reach the degree of vacuum required for the process. Difficult to scale up, there was a problem that mass production is difficult.

The present invention is to solve the problems of the prior art as described above, Bi ₂ Te ₃ p-type thermoelectric thin film element formed using an electroplating method as shown in Figure 2 instead of the flash deposition method or the magnetron sputtering method of the prior art ( 21) and n-type thermoelectric thin film elements 22, and a method of manufacturing the same. In particular, the present invention provides a thermoelectric thin film module formed by forming p-type thermoelectric thin film elements 21 and n-type thermo thin film elements 22 having different compositions from each other by controlling the plating current density in the same electroplating solution, and a method of manufacturing the same. do.

According to the present invention, the problems of the thermoelectric thin film module process using the flash deposition method or the magnetron sputtering method described above are solved, and the manufacturing method of the Bi ₂ Te ₃ based thermo thin film module having a high process speed, easy scale-up, and low process cost is provided. It is possible to provide.

The present invention relates to a method of forming a thermoelectric thin film module using an electroplating method, comprising an electroplating solution or a bismuth (Bi) ion source and an antimony (Sb) ion containing a bismuth (Bi) ion source and a tellurium (Te) ion source. Immersion of the substrate 23 having the electroplating seed layer 31 of the p-type thermoelectric thin film element 21 and the n-type thermo thin film element 22 in an electroplating solution containing a source and a tellurium (Te) ion source. Forming the p-type thermoelectric thin film element 21 by electroplating by applying a predetermined plating current density, and forming the n-type thermoelectric thin film element 22 by electroplating by varying the plating current density in the same plating solution. And forming a high temperature end electrode 24 and a low temperature end electrode 25 on the p-type thermoelectric thin film elements 21 and n-type thermoelectric thin film elements 22.

In order to form Bi ₂ Te ₃ p-type thermoelectric thin film elements 21 and n type thermo thin film elements 22 having different compositions by electroplating, Bi ₂ Te _3- based p-type p-types are formed using two plating solutions having different compositions. The thermoelectric thin film element 21 and the n-type thermoelectric thin film element 22 should be electroplated. In this case, in order to plate the n-type thermoelectric thin film element 22 after the p-type thermoelectric thin film element 21 is formed by electroplating in one plating solution, the substrate 23 must be moved to an n-type plating liquid having a different composition. There is discomfort. When the substrate 23 is moved from one plating solution to another, fine substrate cleaning is required. Otherwise, the first plating solution is mixed in the second plating solution, thereby preventing the formation of a thermoelectric thin film device having a Seebeck coefficient having desired characteristics.

On the other hand, in the method for forming a thermoelectric thin film module according to the present invention, Bi ₂ Te ₃ p-type thermoelectric thin film elements 21 and n-type thermo thin film elements 22 having different compositions by simply changing the plating current density in the same plating solution are used. By the method of forming sequentially, there exists a convenient advantage in process.

The material which may be the bismuth ion source, the tellurium ion source and the antimony ion source includes any material commonly available for electroplating and is not required to be limited to a specific kind of material. Examples of the bismuth ion source may include Bi ₂ O ₃ , Bi (NO ₃ ) ₃ , Bi-EDTA complex, and metal Bi.Telelium ion sources include TeO ₂ and metal Te. Antimony ion sources include Sb ₂ O ₃ , SbCl ₃ , and metal Sb. The composition of the specific plating solution containing the ion sources is obvious to those of ordinary skill in the art, and depending on the composition of the desired p-type or n-type thermoelectric thin film device, bismuth ions or tellurium may be used. It may be possible to increase or decrease the concentration of ions or antimony ions.

In addition, the pH and temperature of the plating liquid do not require specific conditions. In the embodiment of the present invention was carried out the electroplating of the p-type thermoelectric thin film element 21 and the n-type thermoelectric thin film element 22 under the conditions of pH 2.0 to 2.5 and room temperature, which is one of the embodiments for carrying out the present invention. This is just a preferred example and does not preclude the choice of another pH and temperature condition of the plating solution.

This invention will be described by the following examples. However, these do not limit the rights of the present invention.

<Example 1>

Bi ₂ Te ₃ p-type thermoelectric thin film elements 21 and n-type thermoelectric thin film elements 22 are electroplated to form bismuth (Bi) ion concentration and tellurium (Te) in a 1M nitric acid (HNO ₃ ) solution. ) Bi ₂ O ₃ powder and TeO ₂ so that ion concentration is 40mM and 10mM The powder was weighed and stirred for 24 hours to dissolve to form an electroplating solution.

Sikimyeo changing the plating current density in plating Bi ₂ Te _3, such as the electricity to 5.5mA / cm ² at 0.1mA / cm ² exhibited a Seebeck coefficient of electroplating a Bi ₂ Te ₃ Thermoelectric thin film are shown in Table 1.

Table 1. Seebeck coefficient of Bi ₂ Te ₃ thermoelectric thin film according to plating current density

Plating Current Density (mA / cm ² ) 0.1 0.5 1.5 2.5 4.5 5.5 Seebeck coefficient (㎶ / K) 80 -106 -150 -118 108 98

As shown in Table 1, when electroplating at a low plating current density of 0.1 mA / cm ^{2 in} a plating solution having a bismuth ion concentration of 40 mM and a tellurium ion concentration of 10 mM, the p-type Bi ₂ Te ₃ having a positive Seebeck coefficient was obtained. The thermoelectric thin film was plated.

On the other hand, when plating current density is applied in the range of 0,5 mA / cm ² to 3.5 mA / cm ² and electroplated, n-type Bi ₂ Te ₃ with negative Seebeck coefficient as shown in Table 1 The thermoelectric thin film was plated, because in this plating current density range, tellurium ions having a faster plating rate than the bismuth ions were electrodeposited to form an n-type Bi ₂ Te ₃ thermoelectric thin film having a tellurium excess composition.

Bi ₂ Te ₃ as above When the plating current density was increased to 4.5 mA / cm ² or more in the plating solution, a p-type Bi ₂ Te ₃ thermoelectric thin film having a positive Seebeck coefficient was plated as shown in Table 1, and the reason for this was high plating. This is because the electrodeposited amount of bismuth ions much more present in the plating solution was greatly increased under the condition of the current density to form a p-type Bi ₂ Te ₃ thermoelectric thin film having a bismuth excess composition.

Using that this way the same Bi ₂ to form a p-type thermoelectric thin film element and the n-type thermoelectric thin film element by controlling the plating current density at Te ₃ plating solution, p-type thermoelectric films on the same Bi ₂ Te ₃ plating solution in the present embodiment The element 21 and the n-type thermoelectric thin film element 22 were electroplated to constitute a thermoelectric thin film module. The schematic diagram of the manufacturing process of a present Example is shown in FIG.

As the substrate 23 for forming the thermoelectric thin film module, the polyimide film was ultrasonically cleaned for 30 seconds using acetone, alcohol, and distilled water, and blown with nitrogen gas to remove impurities attached to the surface.

10 ^-5 to 10 ^-6 after attaching the polyimide film substrate 23 to the substrate holder in the sputter chamber The water adsorbed on the polyimide film substrate 23 was removed by maintaining the temperature at 150 ° C. for 30 minutes in a vacuum state of the tor. In order to improve the adhesion between the polyimide film and the titanium (Ti) thin film to be sputtered with the seed layer 31 for electroplating, the surface of the polyimide film substrate 23 was RF sputtered using argon (Ar) gas. On the surface of the polyimide substrate 23 as described above, a titanium thin film, which is the seed layer 31 for electroplating, was formed to have a thickness of 1 μm by the magnetron sputtering method as shown in FIG.

Position of the seed layer 31 for electroplating as shown in FIG. 3 (b) by using photolithography on the polyimide substrate 23 on which the titanium thin film was formed as the seed layer 31 for electroplating as described above. Open photoresist pattern 32 was formed.

Bi ₂ O ₃ powder and TeO _{2 in a} concentration of 40mM and 10mM of bismuth (Bi) and tellurium (Te) ions in 1M nitric acid (HNO ₃ ) solution, respectively The polyimide substrate 23 having the photoresist pattern 32 formed on the cathode was placed in the cathode in the electroplating solution prepared by weighing the powder and stirring for 24 hours to dissolve it. Electroplating of the Bi ₂ Te ₃ thermoelectric thin film element 21 and the n-type thermoelectric thin film element 22 was performed.

By applying a current of 4.5 mA / cm ² to the titanium electroplating seed layer 31 for electroplating the p-type thermoelectric thin film element 21, the bismuth excess composition having a positive Seebeck coefficient as shown in Table 1 was obtained. The p-type Bi ₂ Te ₃ thermoelectric thin film element 21 was electroplated as shown in FIG. 3 (c). After the electroplating of the p-type thermoelectric thin film element 21 is completed, a current of 1.5 mA / cm ² is applied to the seed layer 31 for titanium electroplating for the electroplating of the n-type thermoelectric thin film element 22. Similarly, the n-type Bi ₂ Te ₃ thermoelectric thin film element 22 having a tellurium excess composition having a negative Seebeck coefficient was electroplated as shown in FIG. 3 (d).

Same Bi ₂ Te ₃ as above After forming the p-type thermoelectric thin film elements 21 and the n-type thermoelectric thin film elements 22 in the plating solution by electroplating and removing the photoresist 32 pattern as shown in FIG. 3 (e), as shown in FIG. 3 (f). p-type thermoelectric thin film elements 21 and n-type thermoelectric thin film elements 22 are thermally deposited by high-temperature end electrodes 24 at one end of the thermal thin film elements 21 and 22 so that they are electrically connected in series and thermally in parallel. The Ni-Cr electrode was formed by using an aluminum electrode, and the other end was formed of an aluminum electrode using a magnetron sputtering method as a low temperature end electrode 25 to form a thermoelectric thin film module. In the thermoelectric thin film module as described above, a portion where the Ni-Cr electrode, which is the hot end electrode 24, is formed is a high temperature end that absorbs infrared rays, and a portion where the aluminum electrode, which is the low temperature end electrode 25, is formed is a low temperature end.

In this embodiment, a Ni-Cr electrode is used as the infrared absorption electrode serving as the high temperature end electrode 24. In the present invention, the porous platinum black body (Pt black) formed by the electrochemical method with the high temperature end electrode 24 or gold (Au), silver (Ag), platinum (Pt), aluminum (deposited in a low vacuum nitrogen atmosphere) It is also possible to use a porous metal film made of Al), copper (Cu), chromium (Cr), nickel (Ni) porous metal film or an alloy containing any one or more metals selected from these metals. In the present embodiment, an aluminum electrode is used as the low temperature end electrode 25, but in the present invention, as the low temperature end electrode 25, a gold, silver, platinum, copper, chromium, aluminum, nickel thin film or any one selected from these metals is used. It is also possible to use metal films made of alloys containing at least one metal.

In this embodiment, the thermoelectric thin film module is composed of one p-type thermoelectric thin film element 21 and one n-type thermoelectric thin film element 22. In addition, in the present invention, the same Bi ₂ Te ₃ It is also possible to form a thermoelectric thin film module by forming the same number of n-type thermoelectric thin film elements as the p-type thermoelectric thin film elements and the p-type thermo thin film elements in the plating solution by electroplating.

In the present embodiment, titanium (Ti) was used as the seed layer 31 for electroplating the Bi ₂ Te ₃ p-type thermoelectric thin film element 21 and the n-type thermoelectric thin film element 22. In addition, in the present invention, as the seed layer for electroplating, electrical conductors titanium (Ti), copper (Cu), aluminum (Al), platinum (Pt), gold (Au), silver (Ag), iron (Fe), nickel It is also possible to use any metal selected from (Ni), chromium (Cr), tantalum (Ta) and tungsten (W), and it is also possible to use an alloy containing two or more metals selected from these. In addition, the titanium (Ti), copper (Cu), aluminum (Al), platinum (Pt), gold (Au), silver (Ag), iron (Fe), nickel (Ni), chromium (Cr), tantalum (Ta) ), It is also possible to use a seed layer for multi-layer electroplating consisting of two or more metals selected from tungsten (W).

In the present invention, the method for forming the seed layer 31 for electroplating includes vacuum deposition, electroplating, electroless plating, screen printing, electron beam deposition, chemical vapor deposition, MBE, including the sputtering method according to the present embodiment. Any thin film formation method or coating method can be used.

In the present embodiment, a polyimide film was used as the substrate 23 for forming the thermoelectric thin film module by electroplating the Bi ₂ Te ₃ p type thermoelectric thin film element 21 and the n type thermoelectric thin film element 22. In addition, in the present invention, a substrate for constituting the thermoelectric thin film module may be a polymer substrate such as Teflon or plastic, a ceramic substrate such as alumina, aluminum nitride, silicon carbide, silicon oxide (SiO ₂ ), and a silicon (Si) wafer. Do.

In this embodiment, the same Bi ₂ Te ₃ After the p-type thermoelectric thin film element was formed by electroplating in the plating solution, the n-type thermoelectric thin film element was electroplated by changing the plating current density. In addition, in the present invention, the same Bi ₂ Te ₃ It is also possible to electroplat the p-type thermoelectric thin film element by first forming the n-type thermoelectric thin film element by electroplating in the plating solution and then changing the plating current density.

In this embodiment, after forming the photoresist pattern 32 in which the position of the seed layer 31 for electroplating is opened on the substrate 23 by using a photolithography method, the p-type thermoelectric film element 21 is formed. And n-type thermoelectric thin film elements 22 were electroplated. In addition, in the present invention, the plating current density is applied to the seed layer 31 for electroplating without forming the photoresist pattern 32 as described above, thereby forming the p-type thermoelectric thin film element 21 and the n-type thermoelectric thin film element 22. It is also possible to form a thermoelectric thin film module by forming an electroplating.

<Example 2>

Bismuth (Bi) ions in a 5M nitric acid (HNO ₃ ) solution as a plating solution for electroplating the p-type thermoelectric thin film element 21 and the n-type thermoelectric thin film element 22 in the same (Bi, Sb) ₂ Te ₃ plating solution. Bi ₂ O ₃ powder, Sb ₂ O _{3 '} powder and TeO ₂ so that the concentration, antimony (Sb) ion and tellurium (Te) ion concentration are 5mM, 15mM and 10mM, respectively. The powder was weighed, stirred for 24 hours, dissolved, and an electroplating solution was made by adding EDTA to a concentration of 60 mM as a plating additive. And the like (Bi, Sb) ₂ Te ₃ electroplating sikimyeo change in the current density to 1.5mA / cm ² at 0.3mA / cm ² electroplating a (Bi, Sb) ₂ Te ₃ Table the Seebeck coefficient of the thermoelectric films 2 is shown.

Table 2. Seebeck coefficient of (Bi, Sb) ₂ Te ₃ thermoelectric thin film according to plating current density

Plating Current Density (mA / cm ² ) 0.3 0.5 0.6 0.7 1.0 1.5 Seebeck coefficient (㎶ / K) 139 150 112 82 -124 -110

As shown in Table 2, a bismuth ion concentration of 5mM, applying a plating current density of the antimony ion concentration 15mM, 10mM Tel ryuryum ion concentration of 0.3mA / cm ² ~0.7mA / cm ² range in the plating solution, and a thin film coating is a positive (+) Represents the Seebeck coefficient of p-type (Bi, Sb) ₂ Te ₃ The thermoelectric thin film was plated. The reason for this is that at current densities ranging from 0.3 mA / cm ² to 0.7 mA / cm ² , more bismuth ions and antimony ions in the plating solution are electrodeposited than tellurium ions, resulting in p-type (Bi, Sb) ₂ Te ₃ This is because a thermoelectric thin film is formed. 1.0 mA / cm ² on the other hand When the above plating current density was applied, the n-type thermoelectric thin film was plated by exhibiting a negative Seebeck coefficient, which was more electrodeposited by the faster tellurium ions to form an n-type thermoelectric thin film having a tellurium excess composition. Because

Like this (Bi, Sb) ₂ Te ₃ By controlling the plating current density in the plating solution, the p-type thermoelectric thin film element 21 can be formed from the same (Bi, Sb) ₂ Te ₃ plating solution in the present embodiment by using the p-type thermal thin film element and the n-type thermal thin film element. ) And n-type thermoelectric thin film elements 22 were electroplated to constitute a thermoelectric thin film module.

As a substrate 23 for forming the thermoelectric thin film module, the polyimide film was ultrasonically washed with acetone, alcohol, and distilled water for 30 seconds each, blown with nitrogen gas to dry, and impurities removed from the surface were removed.

10 ^-5 to 10 ^-6 after attaching the polyimide film substrate 23 to the substrate holder in the sputter chamber The water adsorbed on the polyimide film substrate 23 was removed by maintaining the temperature at 150 ° C. for 30 minutes in a vacuum of the tor. After RF sputtering the surface of the polyimide film substrate 23 using argon (Ar) gas, the seed layer 31 for electroplating on the surface of the polyimide substrate 23 by magnetron sputtering as shown in FIG. ) Was formed to a thickness of 1㎛.

The position of the electroplating seed layer 31 is opened as shown in FIG. 3 (b) by using photolithography on the polyimide substrate 23 having the titanium electroplating seed layer 31 as described above. An open photoresist pattern 32 was formed.

Bi ₂ O ₃ powder, Sb ₂ O _{3 in} 5M nitric acid (HNO ₃ ) solution, so that bismuth (Bi) ion concentration, antimony (Sb) ion concentration and tellurium (Te) ion concentration are 5mM, 15mM and 10mM, respectively _' Weigh the powder and TeO ₂ powder, and install the polyimide film substrate 23 having the photoresist pattern 32 described above in the cathode in an electroplating solution made by adding EDTA to a concentration of 60 mM as a plating additive. Electroplating of the p-type thermoelectric thin film element 21 and the n-type thermoelectric thin film element 22 was carried out using the platinum electrode as an anode as follows.

A p-type (Bi) having a positive Seebeck coefficient as shown in Table 2 by applying a current of 0.5 mA / cm ² to the seed layer 31 for titanium electroplating for electroplating the p-type thermal thin film element 21. , Sb) The ₂ Te ₃ thermoelectric thin film element 21 was electroplated as shown in FIG. 3 (c). p-type (Bi, Sb) ₂ Te ₃ After the electroplating of the thermoelectric thin film element 21 is completed, a current of 1.0 mA / cm ² is applied to the seed layer 31 for titanium electroplating for electroplating the n-type thermoelectric thin film element 22, as shown in Table 2 below. An n-type thermoelectric thin film element 22 having a Seebeck coefficient of (−) was electroplated as shown in FIG. 3 (d).

Same as above (Bi, Sb) ₂ Te ₃ After forming the p-type thermoelectric thin film elements 21 and the n-type thermoelectric thin film elements 22 in the plating solution by electroplating and removing the photoresist pattern 32 as shown in FIG. 3 (e), as shown in FIG. 3 (f). p-type thermoelectric thin film elements 21 and n-type thermoelectric thin film elements 22 are thermally deposited by high-temperature end electrodes 24 at one end of the thermal thin film elements 21 and 22 so that they are electrically connected in series and thermally in parallel. The Ni-Cr electrode was formed using the low-temperature electrode 25 and the aluminum electrode was formed using the magnetron sputtering method as the low-temperature end electrode 25 to form a thermoelectric thin film module.

According to the present invention, instead of plating the p-type thermoelectric thin film elements and the n-type thermoelectric thin film elements in two different plating liquids, the plating current density is changed in one plating liquid, thereby electroplating the p-type thermal thin film elements and the n-type thermoelectric thin film elements. By constructing the thermoelectric thin film module, there is a process advantage that the miniaturized bismuth fluoride-based thermoelectric thin film module can be formed at a high process speed and a low process cost.

Claims (10)

Dipping a substrate having a p-type thermal thin film element and a seed layer for electroplating n-type thermo thin film elements in an electroplating solution containing a bismuth (Bi) ion source and a tellurium (Te) ion source; Forming a p-type thermoelectric thin film element by electroplating by applying a predetermined plating current density to the electroplating seed layer of the device, changing the plating current density in the same plating solution, and electroplating seed layer of the n-type thermal thin film element Forming an n-type thermoelectric thin film element by electroplating, and forming a hot end electrode and a low temperature end electrode on the p-type thermoelectric thin film element and the n-type thermoelectric thin film elements. Module manufacturing method. A substrate having a seed layer for electroplating p-type thin film elements and n-type thin film elements in an electroplating solution containing a bismuth (Bi) ion source, an antimony (Sb) ion source, and a tellurium (Te) ion source. Dipping and applying a predetermined plating current density to the electroplating seed layer of the p-type thermoelectric thin film element to form the p-type thermoelectric thin film element by electroplating; varying the plating current density in the same plating solution and changing the n-type thermoelectric Forming an n-type thermoelectric thin film element by electroplating by applying it to an electroplating seed layer of the thin film element, and forming a hot end electrode and a low temperature end electrode on the p-type thermoelectric thin film element and the n-type thermoelectric thin film element. Method for producing a thermoelectric thin film module, characterized in that consisting of. The method according to claim 1, wherein the high-temperature end electrode is a Ni-Cr film, porous platinum black body (Pt black) or gold (Au), silver (Ag), platinum (Pt), aluminum (Al), copper (Cu), chromium A porous metal film made of (Cr), a porous metal film of nickel (Ni) or an alloy containing at least one metal selected from these metals is used, and as the low-temperature electrode, aluminum, gold, silver, platinum, copper, chromium And a nickel metal film or a metal film made of an alloy containing at least one metal selected from these metals. The method according to claim 2, wherein the high-temperature end electrode is a Ni-Cr film, porous platinum black body (Pt black) or gold (Au), silver (Ag), platinum (Pt), aluminum (Al), copper (Cu), chromium A porous metal film made of (Cr), a porous metal film of nickel (Ni) or an alloy containing at least one metal selected from these metals is used, and as the low-temperature electrode, aluminum, gold, silver, platinum, copper, chromium And a nickel metal film or a metal film made of an alloy containing at least one metal selected from these metals. The method according to claim 1, wherein the seed layer for electroplating the p-type thermal thin film device and the n-type thermal thin film device is titanium (Ti), copper (Cu), aluminum (Al), platinum (Pt), gold (Au) ), Silver (Ag), iron (Fe), nickel (Ni), chromium (Cr), tantalum (Ta), tungsten (W), or any one metal selected from, or containing two or more metals selected from A method of manufacturing a thermoelectric thin film module comprising an alloy or two or more multilayer structures selected from them. The method according to claim 2, wherein the seed layer for electroplating the p-type thermal thin film device and the n-type thermal thin film device is titanium (Ti), copper (Cu), aluminum (Al), platinum (Pt), gold (Au) ), Silver (Ag), iron (Fe), nickel (Ni), chromium (Cr), tantalum (Ta), tungsten (W), or any one metal selected from, or containing two or more metals selected from A method of manufacturing a thermoelectric thin film module comprising an alloy or two or more multilayer structures selected from them. The thermoelectric thin film according to claim 1, wherein a polymer substrate, a ceramic substrate, or a silicon (Si) wafer is used as a substrate for forming the thermoelectric thin film module by electroplating the p-type thermoelectric thin film element and the n-type thermoelectric thin film element. Module manufacturing method. The thermoelectric thin film according to claim 2, wherein a polymer substrate, a ceramic substrate, or a silicon (Si) wafer is used as a substrate for forming a thermoelectric thin film module by electroplating the p-type thin film thin film element and the n-type thermo thin film thin film element. Module manufacturing method. The method according to claim 1, wherein the n-type thermoelectric thin film element is first formed by electroplating in the same plating solution, and then the plating current density is changed to electroplat the p-type thermo thin film element. The method according to claim 2, wherein the n-type thermoelectric thin film element is first formed by electroplating in the same plating solution, and then the plating current density is changed to electroplat the p-type thin film thin film element.

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