JP2004221375A - Method of manufacturing thermoelectric semiconductor, thermoelectric converter, and thermoelectric conversion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a thermoelectric semiconductor used for manufacturing a highly efficient thermoelectric converter or a thermoelectric conversion device which is capable of restraining elements from becoming irregular in thermoelectric conversion properties, and to provide a method of manufacturing the thermoelectric converter and the thermoelectric conversion device. <P>SOLUTION: At least, n-type thermoelectric semiconductor element material is compacted into an n-type thermoelectric semiconductor element material 1A. A low oriented region 1b located inside the compact surfaces is removed from the thermoelectric semiconductor element material 1A as thick as prescribed along the compact surface. The modified thermoelectric semiconductor element material 1A is bonded to a p-type thermoelectric semiconductor element material 12A which is manufactured in the same method as above to obtain a joined body, and the joined body is divided into paired elements 5. The large number of the paired elements 5 are tabularly bonded together. Electrodes 7 and 8 and supports 19 and 24 are fixed on the board composed of the paired elements 5 to form a thermoelectric converter 11, such as a Peltier element or the like. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method for manufacturing a thermoelectric semiconductor used for a thermoelectric conversion device using a thermoelectric conversion device such as a Peltier device, a method for manufacturing a thermoelectric conversion device, and a method for manufacturing a thermoelectric conversion device using the same.
[0002]
[Prior art]
Conventionally, a Peltier cooling element using the Peltier effect is known as a type of heat pump using a thermoelectric (conversion) semiconductor. When a DC voltage is applied, one side of the element generates heat and the other side generates heat. Has a feature of absorbing heat, and by utilizing this principle, applications to a constant temperature plate for a semiconductor process, a heat storage, a CPU (Central Processing Unit) cooler, and the like are expanding. In this Peltier cooling element, the smaller the temperature difference between the heat generation side and the heat absorption side, the higher the cooling effect.
[0003]
Separately, a Seebeck power generation element using the Seebeck effect is also known.By applying heat to one side of the element and creating a temperature difference between the upper and lower parts of the element, it is possible to generate power with low efficiency. This principle is used in power generation wristwatches and small storage batteries. In this Seebeck power generation element, the generated electromotive force (thermal electromotive force) increases as the temperature difference between the upper and lower parts of the element increases.
[0004]
Here, the Peltier effect, the Seebeck effect, and the like are collectively referred to as a thermoelectric conversion effect, and a Peltier cooling element and a Seebeck power generation element using these effects are referred to as a thermoelectric conversion element.
[0005]
The Peltier cooling element and the Seebeck power generation element have exactly the same structure, although the operation methods are different.
[0006]
19, the structure of a conventional general thermoelectric conversion element (for example, a Peltier cooling element) will be described.
[0007]
In the thermoelectric conversion device 80 provided with the thermoelectric conversion element 57, Sb is provided between the upper support 74 and the lower support 75 of a ceramic substrate made of alumina, aluminum nitride or the like on which the plate-like metallic lower electrode 53 is formed.₂Te₃-Bi₂Te₃A p-type thermoelectric semiconductor element 52 (hereinafter, sometimes referred to as a p-type element or simply an element) made of an alloy or the like, and Bi₂Te₃-Bi₂Se₃An n-type thermoelectric semiconductor element (hereinafter, may be simply referred to as an n-type element or simply an element) 51 made of an alloy or the like is alternately arranged, and each thermoelectric semiconductor element is soldered to the metallic lower electrode 53. It has a structure.
[0008]
A heating element 58 such as a semiconductor heating component is fixed on one ceramic substrate 74 (upper support) in contact with the other, and the lower electrode 53 of the other ceramic substrate 74 (lower support) is connected to a thermoelectric element. A lead wire 55 for applying a DC voltage to the conversion element 57 is connected.
[0009]
Then, on one substrate surface side, heat is absorbed by conducting electricity from the n-type thermoelectric semiconductor element 51 to the p-type thermoelectric semiconductor element 52, and on the other substrate surface side, the heat is absorbed from the p-type thermoelectric semiconductor element 52 to the n-type thermoelectric semiconductor element 51. The heat is generated by energizing to.
[0010]
Here, as the thermoelectric conversion material as the material of the n-type thermoelectric semiconductor element 51 and the p-type thermoelectric semiconductor element 52, generally, a material having a high figure of merit Z represented by the following equation is used.
[0011]
Z = α²・ Σ / κ
(However, α is an electromotive force obtained when a temperature difference of 1 K (Kelvin temperature) occurs in the thermoelectric semiconductor material and is called a Seebeck coefficient, and σ represents the electric conductivity of the thermoelectric semiconductor material. , Κ represent the thermal conductivity of the thermoelectric semiconductor material.)
[0012]
Therefore, in order to increase the value of the figure of merit Z, α representing electric performance²-It is necessary not only to increase the value of σ but also to decrease the value of the thermal conductivity κ.
[0013]
However, in general, in a thermoelectric semiconductor material, as the value of σ increases, the value of α tends to decrease.
[0014]
At present, the thermoelectric semiconductor material generally used as a Peltier cooling element is Bi.₂Te₃System material, whose figure of merit Z is 3.0 × 10^-3K^-1It is about.
[0015]
On the other hand, as shown in FIG. 20, a thermoelectric conversion element 57 having a skeleton structure excluding a ceramic substrate 74 has been proposed in order to increase the heat absorption efficiency of the thermoelectric conversion element 57 with respect to a heating element.
[0016]
This skeleton structure is such that an n-type thermoelectric semiconductor element 51 and a p-type thermoelectric semiconductor element 52 are connected by a lower metal electrode 53 and an upper metal electrode 54 (this connection is the same in the apparatus shown in FIG. 19). ), Each element is connected in series in a meandering manner by two rows of upper electrodes 54 having the same shape and the same direction and three rows of lower electrodes 53 whose directions are changed at the folded positions.
[0017]
In the thermoelectric conversion device as described above, the n-type element and the p-type elements 51 and 52 are connected in series via the electrode 53 and the electrode 54, but the larger the number of elements, the larger the heat absorption as a Peltier element. Therefore, the electromotive force generated as a Seebeck power generation element increases. Therefore, the cross-sectional area of the element is determined so as to increase the number of elements per unit area. The size of the current thin element is about 0.5 mm × 0.5 mm × 1.0 mm.
[0018]
Next, in order to manufacture the above-described thermoelectric conversion device (module), as shown in FIG. 21, for example, a wiring pattern (metal lower electrode) 53 is formed on a lower support 74 made of a ceramic substrate, and The n-type thermoelectric semiconductor element 51 and the p-type thermoelectric semiconductor element 52 are arranged on the substrate 74 manually or by using a robot 81 (robot arm), and soldered while holding each element from above and below, as shown in FIG. Is assembled as shown in FIG. In this case, the n-type thermoelectric semiconductor elements 51 and the p-type thermoelectric semiconductor elements 52 are alternately arranged, and are connected in series by the lower electrode 53.
[0019]
By the way, since the n-type thermoelectric semiconductor elements 51 and the p-type thermoelectric semiconductor elements 52 of the same shape and the same color must be alternately arranged, it is necessary to arrange each element at an incorrect position or to handle a miniaturized element. As a result, quality problems such as cracking or chipping of the element occur, and the assembly operation involves a great deal of trouble and difficulty.
[0020]
When the robot 81 is used for arranging the elements 51 and 52 as described above, the distance between the elements depends on the size of the arm of the robot 81, which is not suitable for the high-density mounting process. Conversely, if the distance between the n-type and p-type elements 51 and 52 is small, when soldered to the electrodes, there is a possibility that a solder bridge will occur between the electrodes that should not be connected and short-circuit between the elements. is there.
[0021]
In order to solve these problems, the n-type and p-type thermoelectric semiconductor blocks are bonded on each substrate, and the respective blocks are diced, so that the substrate on which the n-type thermoelectric semiconductor elements 51 are arranged and the p-type thermoelectric There is a method in which a substrate on which the semiconductor elements 52 are arranged is prepared, and these two substrates are combined on the element side.
[0022]
Further, the n-type and p-type thermoelectric semiconductor blocks are each subjected to a fine groove processing at a fine pitch to form an n-type grooved block and a p-type grooved block, and these grooved processing portions are vertically aligned. A method has also been proposed for fabricating a thermoelectric conversion element by bonding the components together with an adhesive layer and integrating them.
[0023]
However, in these methods, it is necessary to form a groove in the semiconductor block or to cut off the connecting portion after the groove forming process, so that the material loss is considerably large.
[0024]
On the other hand, a method of manufacturing the thermoelectric conversion device 80 as shown in FIGS.
[0025]
First, as shown in FIG. 22 (a), n-type and p-type thermoelectric semiconductor element materials 51A and 52A having a thickness corresponding to the elements 51 and 52 are bonded with a polymer material (not shown) to form a block 82. I do.
[0026]
Thereafter, as shown in FIG. 23 (b), the block 82 is cut along the cutting line 83, and as shown in FIG. 23 (c), the rod-shaped n-type and p-type thermoelectric semiconductor element materials 51A and 52A are formed. A divided block 84 made of a joined body is formed.
[0027]
Next, as shown in FIG. 24D, the horizontally divided block 84 is cut along a cutting line 85, and as shown in FIG. 24E, the n-type and p-type thermoelectric semiconductor elements 51 and A rod-shaped element joined body 86 in which 52 are alternately arranged is prepared, and a plurality of rod-shaped element joined bodies 86 are stuck in a pattern in which the conductive elements 51 and 52 are alternately arranged as shown in FIG. Together, a flat element bonded body 87 is formed.
[0028]
Next, as shown in FIG. 25 (g), an electrode material is vapor-deposited on the upper and lower surfaces of the plate-like element assembly 87 and then patterned to form a pattern similar to that shown in FIG. Then, as shown in FIG. 25 (h), an upper support 75 and a lower support (protective plate) 74 are bonded to the upper and lower surfaces of the element assembly 87 via respective electrodes according to the application, as shown in FIG. Then, the lead wires 55 are connected to complete the thermoelectric conversion device 80.
[0029]
Here, as a material of thermoelectric conversion semiconductors currently generally commercially available, for example, Sb₂Te₃-Bi₂Te₃A p-type thermoelectric semiconductor element material composed of an alloy or the like, and Bi₂Te₃-Bi₂Se₃An n-type thermoelectric semiconductor element material made of an alloy or the like is used.
[0030]
As a method for producing these materials, for example, a method of producing an ingot by a unidirectional solidification treatment such as the Bridgman method, and cutting the produced ingot into an element as it is, or a method of unidirectional solidification such as the Bridgman method A method of producing a high-strength thermoelectric semiconductor element material by producing an ingot by a solidification process, pulverizing the ingot into a powder, solidifying the powder into a powder compact, and sintering the powder. Is generally known.
[0031]
For example, the material is produced by a sintering method such as an electric current sintering method generally called a hot press method, a PAS (Plasma Activated Sintering) method or an SPS (Spark Spark Sintering) method.
[0032]
Here, as shown in FIG. 26, an example of a processing method used for a hot press method, a current sintering method, or the like will be described.
[0033]
First, as shown in FIG. 26A, an ingot made of a thermoelectric semiconductor material is crushed into a cylindrical through hole 92 provided at the center of a cylindrical die 93, and then formed into a cylindrical shape. The punch 90 </ b> A and the punch 90 </ b> B are inserted into the hole 92 from above and below the hole 92, respectively, such that the sintered material (powder molded body) 91 is sandwiched in the hole 92 from above and below.
[0034]
Thereafter, as shown in FIG. 26 (b), the material to be sintered 91 is sandwiched from above and below by pressurization by the punches 90A and 90B.
[0035]
Then, as shown in FIG. 27A, by sintering the thin plate-shaped material to be sintered 91 while compressing or applying an electric current from above and below, the crystal axis direction indicating the orientation becomes the compression direction, and the compression processing is performed. A portion having high thermoelectric properties is generated in the a-axis direction perpendicular to the plane, and as a result, a low orientation region 71b is formed at the center of the sintered material 91, and a high orientation region 71a is formed at both sides (near the compression surface). Occurs in the plane direction.
[0036]
As a hot press method, for example, a bismuth tail element material is melted, and the melted element material is cooled to form an alloy, which is then turned into a powder. To produce a thin-plate-shaped thermoelectric semiconductor element material, and stack a plurality of the thin-plate-shaped thermoelectric semiconductor element materials, and then hot-press the thin-plate surfaces of the plurality of thermoelectric semiconductor element materials again from the vertical direction. (See, for example, Patent Document 1).
[0037]
Further, as a PAS method, a powdery thermoelectric semiconductor element material is filled in a compression and sintering device inside a chamber, the powder is compressed, and a pulse current is applied to the powder, so that a powder current is applied. There is a method of forming a molded thermoelectric semiconductor element material by releasing an adsorbed gas adsorbed on a material and sintering the powders (for example, see Patent Document 2).
[0038]
Next, as shown in FIG. 27 (b) to FIG. 28, a description will be given of the principle of occurrence of a physical mechanism generated in the material to be sintered 91 during the compression or electric current sintering step.
[0039]
First, FIGS. 27B and 27C are schematic diagrams of powder particles 94 constituting the material to be sintered 91, and FIG. 27B shows a state of the particles 94 before sintering. ing.
[0040]
Then, as schematically shown in FIG. 27C, when the particles 94 are compressed or electrically sintered, the particles 94 are crushed in the a-axis direction. Due to the bonding, the material becomes flatter than the material to be sintered 91 before sintering, and the crystal axis direction is more likely to be in the compression direction, and in the a-axis direction near the compression surface, a highly oriented region 71a having good thermoelectric properties is generated. .
[0041]
That is, as shown in the molecular structure diagram of FIG. 28, in the case of the structure of the material to be sintered 91 which is a Bi-Te-based material used for the n-type element 51 and the p-type element 52, Pb-Te, Si-Ge Unlike materials such as these, they have a hexagonal structure, and therefore have high thermoelectric characteristics in the direction of the a-axis. Thus, it can be understood that when Bi-Te is sintered, the direction in which the thermoelectric characteristics are good (the a-axis direction) tends to be uniform in the direction perpendicular to the pressing direction near the pressing surface.
[0042]
[Patent Document 1]
JP-A-2002-185052 (Item 3, right column, Item 5, FIG. 1)
[Patent Document 2]
Japanese Patent No. 3245793 (item 3 right column to item 4 left column, item 7 FIG. 1)
[0043]
[Problems to be solved by the invention]
Next, as shown in FIG. 29 (a), when compression and sintering are performed from above and below, a low orientation region 71 b is generated inside the upper surface 96 and the lower surface 97 (compressed surface), Although a highly oriented region 71a is formed in the plane direction near the compression surface, the thickness of the thin plate-shaped sintered or pressed body 95 is set to, for example, 1.0 mm.
[0044]
Then, in FIG. 29 (b), the sintered or pressed body 95 is measured using an X-ray diffraction spectrum, and the spectrum intensity (arbitrary value) obtained at each position in the plate thickness (unit: mm) direction Is shown.
[0045]
This spectrum shows that the peak intensity is high at the position where the angle (2θ) is about 43 degrees to about 44 degrees, and that the intensity at the other positions is low, the degree of orientation of the a-axis is high, and that the state is good. In other words, it indicates a low orientation state.
[0046]
According to this result, when the position in the plate thickness direction is 0 mm (lower surface) to 0.2 mm and /0.8 mm to 1.0 mm (upper surface) from the lower surface, the region where the angle (2θ) is about 43 degrees to 44 degrees Since the peak intensity is high and the intensity is low at other positions, it can be seen that these positions in the thickness direction, that is, at least 0.2 mm or less from the compressed surface are high orientation regions.
[0047]
On the other hand, in the region where the position in the plate thickness direction is 0.4 mm to 0.6 mm from the compressed surface, the peak intensity is low when the angle (2θ) is about 43 degrees to about 44 degrees, and the intensity is low at other positions. Since it is large, it is a low orientation region.
[0048]
Therefore, it can be seen that in the sintered or pressed body 95, the degree of orientation tends to decrease as approaching the inside from the outer surface.
[0049]
Where Bi₂Te₃Since the sintered or press-formed body 95, which is a thermoelectric semiconductor element material, which is a system material, has anisotropy (orientation) as described above, the hot press method, the PAS method, or the SPS method described above. When the element material is manufactured by a sintering method such as the electric current sintering method generally called the sintering method, it is once pulverized after being manufactured as an ingot, compared with the case of manufacturing by the unidirectional solidification method such as the Bridgman method or zone melting method However, even if this powder is compression-sintered, the degree of orientation of the crystal in the element material is lowered inside, so that a low orientation region is easily generated. Therefore, the figure of merit Z of the produced thermoelectric semiconductor element material is apparent. Will decrease.
[0050]
FIG. 30 shows the degree of orientation (arbitrary value) in the thickness direction of the sintered or pressed body 95. Here, a region in which the degree of orientation is 0.8 or more in relative ratio is defined as a high orientation region 71a.
[0051]
According to this, near the lower surface where the distance z (mm) in the plate thickness direction is 0 mm (lower surface) to 0.4 mm, the degree of orientation is 0.8 to 1.0 and the high orientation region 71a with respect to the a-axis is In addition, also near the upper surface where the distance z (mm) in the thickness direction is 0.6 mm to 1.0 mm (upper surface), the degree of orientation is 0.8 to 1.0 and the height of the a-axis is high. This is the orientation region 71a. However, when the distance z (mm) in the plate thickness direction is 0.4 mm to 0.6 mm, the degree of orientation is 0.5 to 0.8, and the low orientation region 71b about the a-axis (the oblique line in the drawing) Part shown in the figure).
[0052]
However, when producing an ingot by the above-mentioned unidirectional solidification method, when the ingot is processed and the element material is cut out, since the crystallinity is high and the a-axis direction is aligned, the ingot has cleavage in a certain direction. Since it is brittle, it is difficult to cut out a thin plate and the like, and the degree of freedom of the cutout shape is reduced because an ingot that has already been formed is processed.
[0053]
For this reason, if the above-mentioned compression or electric current sintering method is used, there is no need to cut out the ingot, and the degree of freedom in processing into the element is increased. However, as described above, compression sintering of the powder cannot avoid the disadvantage that the degree of orientation inside the obtained molded body is reduced.
[0054]
The present invention has been made in view of the above situation, and an object of the present invention is to produce a thermoelectric semiconductor, a thermoelectric conversion element, or a device with high workability with a high degree of orientation and little variation in performance. It is to provide a manufacturing method.
[0055]
[Means for Solving the Problems]
That is, the present invention provides a step of producing a compression-processed body having a predetermined shape through at least a step of compression-processing a thermoelectric semiconductor material to form a compression-processed body; Removing a predetermined thickness along the compression-processed surface.
[0056]
The present invention also provides a step of obtaining the above-mentioned thermoelectric semiconductor; and joining the first and second thermoelectric semiconductors obtained as the thermoelectric semiconductors having different conductivity types via an insulating material to form a thermoelectric semiconductor joined body. A step of dividing the thermoelectric semiconductor joined body to form an element joined body; joining a plurality of the element joined bodies to form a first electrode and a second electrode on both surfaces thereof, respectively. The present invention relates to a method for manufacturing a thermoelectric conversion element or device.
[0057]
The present invention also provides a step of at least compressing the thermoelectric semiconductor material to form a compacted body; and interposing the first and second compacted bodies having different conductivity types obtained as the compacted body via an insulating material. Joining to form a thermoelectric semiconductor joined body; cutting the thermoelectric semiconductor joined body in a direction intersecting the compression-processed surface to form an element joined body; and forming a first electrode on the first support. Fixing the element joined body through a thermoelectric semiconductor element; removing a predetermined thickness from the thermoelectric semiconductor of the element joined body along the compressed working surface by a predetermined thickness along the compressed working surface; And a method of manufacturing a thermoelectric conversion element or device, comprising the steps of:
[0058]
Here, in the present invention, the compression-processed body includes not only a processed body formed by compressing at least a thermoelectric semiconductor material but also a processed body obtained by cutting and dividing the compressed processed body. Further, the thermoelectric semiconductor and the thermoelectric conversion element refer to a material for manufacturing the thermoelectric conversion device, and an element as a part or a part of the thermoelectric conversion device. In addition to the case where the electrodes are formed on the element side as well as the case where the electrodes are on the support side, the thermoelectric conversion element is used, and even when there is no support (skeleton), the thermoelectric conversion device may be used.
[0059]
According to the present invention, in the compression-processed body of the thermoelectric semiconductor material, a step of removing a region inside the compression-processed surface by a predetermined thickness along the compression-processed surface is included. By removing a low orientation region having insufficient compressibility, the highly oriented thermoelectric semiconductor having good compression processability and thermoelectric conversion characteristics can be obtained. Therefore, a thermoelectric conversion element or device can be manufactured with good workability by dividing, joining, or the like the thermoelectric semiconductor having a high degree of orientation and a small variation in performance.
[0060]
BEST MODE FOR CARRYING OUT THE INVENTION
In the present invention, in order to obtain the thermoelectric semiconductor composed of the highly oriented region, it is preferable that after the thermoelectric semiconductor is subjected to compression processing, the internal low orientation region is removed in parallel with the compression-processed surface.
[0061]
Further, in order for the compact to have high thermoelectric conversion characteristics, it is preferable that the high orientation region of the compact has a degree of orientation of 0.8 or more in relative ratio.
[0062]
In this case, it is preferable that the thickness of the thermoelectric semiconductor composed of the highly oriented region is 0.4 mm to 2 mm or less.
[0063]
Further, the compression-processed body may be cut in a direction crossing the compression-processed surface, and the cut piece may be subjected to the removing step.
[0064]
In addition, it is preferable that a thermoelectric semiconductor ingot is produced by a solidification method, the ingot is powdered, and the powder is subjected to compression sintering to obtain the compact.
[0065]
In addition, in order to improve the strength of the thermoelectric conversion element or the device, a support may be formed on at least one surface of the first and second electrodes.
[0066]
Further, it is preferable that the thermoelectric semiconductor element row is divided in a direction intersecting the element row and separated into individual thermoelectric semiconductor elements.
[0067]
In this case, in order to improve the strength as the thermoelectric conversion element or the device, it is preferable to bond a second support to the thermoelectric semiconductor element via a second electrode.
[0068]
Further, after the first electrode and the second electrode are respectively formed on the element assembly, the support may be fixed on these electrodes.
[0069]
After the first electrode or the second electrode is formed on the element assembly, the element assembly may be fixed on the support.
[0070]
Further, an insulating material may be filled between the thermoelectric semiconductor elements, and the second electrode may be formed on the exposed thermoelectric semiconductor element. As described above, when the dividing or cutting position is filled with the insulating material, the space between the element joints is reinforced, which is advantageous in terms of strength and also has a heat insulating effect.
[0071]
Further, two thermoelectric semiconductor elements of different conductivity types or of the same conductivity type may be arranged to face each other via a dividing groove.
[0072]
In addition, the element assembly is arranged in a plurality of rows, and the first thermoelectric semiconductor element in one row and the second thermoelectric semiconductor in the other row are arranged on the side of the second electrode at the ends of the element assembly rows adjacent to each other. The element may be connected across a row of the first or second thermoelectric semiconductor elements.
[0073]
Further, when a reaction preventing layer is provided between the first electrode or the second electrode and the thermoelectric semiconductor element, it is possible to prevent the electrode material and the thermoelectric semiconductor element material from reacting and being deteriorated by heat generated during the formation of the electrode. . For example, when an electrode layer is deposited on a thermoelectric element by sputtering, vapor deposition, or the like, a reaction preventing layer of gold, nickel, molybdenum, tungsten, or the like is used in order to prevent copper or aluminum gold serving as the electrode layer from reacting with the thermoelectric element material. It is desirable to provide.
[0074]
In addition, in order to enhance the heat conduction efficiency, it is preferable that a support body having a high heat conductor such as graphite integrated therein is arranged at least on the side of the second electrode of the element assembly.
[0075]
In addition, a heating element may be disposed on the second electrode side, and the first electrode side may be a heat radiation side.
[0076]
Further, as the thermoelectric semiconductor element material, Sb is known as a typical example of a Peltier element material.₂Te₃-Bi₂Te₃Alloy, Bi₂Te₃-Bi₂Se₃Alloy, Si-Ge alloy, CoSb₃Alloy, FeSi₂Alloy, YbAl₃Based alloy, NaCo₂O₄And an organic thermoelectric conversion material composed of an alloy such as a Pb-Te alloy or an oxide thermoelectric conversion material and a conductive polymer, but are not limited thereto (the same applies hereinafter).
[0077]
In addition, nickel plating, gold plating, solder bumps, or the like may be applied to the electrodes in order to suppress at least the power loss to the thermoelectric semiconductor elements connected in series.
[0078]
Further, an electrode may be provided on the thermoelectric semiconductor element and the support may be bonded. Alternatively, the electrode may be formed on a support such as ceramics by plating or paste printing, or may be formed by metallization or DBC (Direct Bonding-). (Copper) or the like, which may be bonded to the thermoelectric semiconductor element (also in this case, it is desirable to provide the reaction preventing layer on the electrode).
[0079]
The support is preferably made of a ceramic, for example, a good heat conductive material such as alumina, zirconia, silicon nitride, aluminum nitride, and silicon carbide.
[0080]
Alternatively, when a support made of a polymer or a polymer in which a high thermal conductor such as graphite is integrated is arranged on at least the second electrode side of the thermoelectric element, the device can be stabilized. It is desirable in terms of holding and uniform thermoelectric conversion effect, and it is particularly preferable to provide the high thermal conductive sheet over almost the entire surface of the polymer film.
[0081]
In this case, as the material of the polymer, at least one selected from the group consisting of polyimide, polyethylene terephthalate, polyethylene naphthalate and polyether sulfone, or a thermally conductive silicone rubber filled with a highly thermally conductive filler is used. It is preferable to use the thermoelectric conversion device in order to give flexibility. In addition, the fact that a graphite sheet, an aluminum foil or a copper foil is adhered as the high thermal conductor facilitates the dispersion of heat in the plane, so that the heat distribution in the plane is uniform and the thermoelectric conversion efficiency is increased. Is desirable.
[0082]
Then, a thermoelectric conversion device in which a heating element is arranged on one surface side and the other surface side is a heat radiation side, particularly a device using a Peltier element or a Seebeck power generation element can be configured.
[0083]
Next, a preferred embodiment of the present invention will be specifically described with reference to the drawings.
[0084]
First embodiment
In the present embodiment, as shown in FIG. 1 (a), an ingot obtained by a unidirectional solidification method is pulverized, and a thin n-type thermoelectric semiconductor element material 1A obtained by molding the powder is vertically removed. By compressing and sintering, a portion having a high thermoelectric property is generated in the a-axis direction in which the crystal axis direction is the compression direction and perpendicular to the crystal axis direction. A region 1b is formed, and a highly oriented region 1a is formed in the plane direction near the compression surface.
[0085]
Such compression sintering itself is the same as that already described in FIG. 29 and the like. That is, as a method for producing the n-type thermoelectric semiconductor element material 1A, for example, a raw material having a purity of 5N (99.999%) or more, such as bismuth, tellurium, or selenium, is prepared at a predetermined ratio and melted. The obtained ingot is pulverized and the powder is primarily formed to obtain, for example, a plate-shaped n-type thermoelectric semiconductor element material having a length and a width of 10 mm and a thickness of 2 mm.
[0086]
Then, this is subjected to compression sintering by a hot press method, a PAS method, or an SPS method, so that a high orientation region 1a in which the a-axis is aligned in parallel with the in-plane direction and a low orientation region 1b in which the a axis is not so aligned are formed. A thin n-type thermoelectric semiconductor element material 1A having a length and width of 10 mm and a thickness of 1.2 mm can be obtained. Here, the arrow shown in the figure indicates the a-axis direction of the crystal.
[0087]
Next, as shown in FIG. 1 (b), the compressed n-type thermoelectric semiconductor element material 1A has a width (1.0 mm) which is the same as the height of the n-type thermoelectric semiconductor element manufactured in a later step. By using a dicing blade 15 to cut in a direction crossing the a-axis direction, for example, a prismatic n-type thermoelectric semiconductor element material 1A having a length of 10 mm, a thickness of 1.2 mm, and a width of 1 mm is obtained.
[0088]
Here, it is preferable that the thickness of the element material 1A composed of the high orientation region is 0.4 mm to 2 mm or less.
[0089]
Next, as shown in FIG. 1 (c), the prism-shaped n-type thermoelectric semiconductor element material 1A is tilted 90 degrees in the horizontal direction, and the prism-shaped n-type thermoelectric semiconductor element material is 10 mm long, 1.0 mm thick and 1.2 mm wide. As the n-type thermoelectric semiconductor element material 1A, a high orientation region 1a in which the a-axis is aligned in the vertical direction and a low orientation region 1b in which the a-axis is not so aligned are exposed on the upper surface.
[0090]
Next, as shown in FIG. 2D, the dicing blade 15 cuts and removes only the low-orientation region 1b existing in the center of the n-type thermoelectric semiconductor element material 1A.
[0091]
At this time, for example, when the blade thickness of the dicing blade 15 is set to 180 μm, the width of the actual cut portion is set to 200 μm because the cut portion is slightly increased due to the movement of the blade of the dicing blade 15 during cutting. Become larger.
[0092]
As a result, as shown in FIG. 2 (e), two square rod-shaped element materials 1A each having a length of 10 mm, a width of 0.5 mm, and a height of 1 mm consisting of only the high orientation region 1a having high thermoelectric conversion performance are obtained. Can be.
[0093]
Next, a raw material having a purity of 5N (99.999%) or more such as bismuth, tellurium, or antimony and a dopant are prepared at a predetermined ratio, and the same processes as those in FIGS. 1A to 2E are performed. Thus, a square rod-shaped p-type thermoelectric semiconductor element material 12A having a length of 10 mm, a width of 0.5 mm, and a height of 1 mm is manufactured.
[0094]
Next, as shown in FIG. 2 (f), the side surface of the square rod-shaped n-type thermoelectric semiconductor element material 1A having a length of 10 mm, a width of 0.5 mm, and a height of 1 mm, and a square rod-shaped p-type having the same size and shape. The thermoelectric semiconductor element material 12A is bonded to the side surface of the thermoelectric semiconductor element material 12A via the insulating material 3 having a width of 0.01 mm (10 μm) so that the a-axis direction is the vertical direction.
[0095]
Next, as shown in FIG. 2 (g), the bonded product is cut by a dicing blade 15 into a piece having a width of 0.5 mm to obtain individual pieces. Thus, as shown in FIG. 3 (h), the element pair 5 composed of the n-type thermoelectric semiconductor element 1 and the p-type thermoelectric semiconductor element 12 having a length of 1.01 mm, a width of 0.5 mm and a height of 1 mm. Get.
[0096]
Next, as shown in FIG. 3 (i), a plurality of element pairs 5 are combined in a plate shape and bonded with an adhesive (not shown), and thermoelectric semiconductor elements 1 and 12 of each conductivity type are alternately arranged. The plate-like element joined body 6 having the pattern in the state is formed.
[0097]
In the flat plate element assembly 6, 36 element pairs 5 (72 elements, 12 in the length direction and 6 in the width direction) are combined, and the length is 6.06 mm, the width is 3.0 mm, and the height is 1. This is a flat element bonded body 6 (thermoelectric conversion element block) having a dimension of 0 mm (however, the thickness of the adhesive is ignored).
[0098]
Next, as shown in FIG. 4 (j), gold is deposited as an electrode material on the upper and lower surfaces of the planar element assembly 6 to connect the n-type thermoelectric semiconductor element 1 and the p-type thermoelectric semiconductor element 12. Then, the upper electrode 7 and the lower electrode 8 are formed in the same pattern as shown in FIG.
[0099]
Thereafter, as shown in FIG. 4 (k), an upper support 24 and a lower support (protective plate) 19, which are ceramic substrates for element protection, are adhered to the outer surfaces of the upper electrode 7 and the lower electrode 8 according to the application. Then, the lead wire 10 is connected to the lower electrode 8 to complete the thermoelectric conversion device 11.
[0100]
As shown in FIGS. 5A and 5B, the degree of orientation in the sintered or press-formed body 28 corresponding to the thermoelectric semiconductor element material 1A and the distance z ( mm). Here, a region having a degree of orientation of 0.8 or more is referred to as a high orientation region 1a, and a region having a degree of orientation of less than 0.8 is referred to as a low orientation region 1b. This is because, if the degree of orientation is less than 0.8, the heat transfer characteristics are low and the material of the element is unsuitable.
[0101]
As shown in FIG. 5A, in a region where the distance z (mm) in the plate thickness direction is 0 mm (lower surface) to 0.4 mm, the degree of orientation is 0.8 to 1.0 and the a-axis is highly oriented. Area 1a. Also, the region where the distance z (mm) in the plate thickness direction is 0.6 mm to 1.0 mm (upper surface) is the region 1a in which the degree of orientation is 0.8 to 1.0 and the a-axis is highly oriented. Is shown. In the region where the distance z (mm) in the plate thickness direction is 0.4 mm to 0.6 mm (the portion shown by oblique lines in the drawing), the orientation degree is 0.5 to 0.8 and the low orientation region 1b It is shown that.
[0102]
Therefore, as shown in FIG. 5B, the low orientation region 1b is cut and removed with a dicing blade or the like as described in FIG. The type thermoelectric semiconductor element material 1A (or p-type thermoelectric semiconductor element material 12A) can be obtained.
[0103]
In the step of forming the upper electrode 7 or the lower electrode 8, for example, a 100 μm-thick copper electrode 7 or 8 having a thickness of 100 μm is formed on the support 19 or 24 made of aluminum nitride by, for example, a DBC (Direct Bonding Copper) method. May be etched to form an electrode pattern, on which gold plating may be further performed to prevent corrosion and diffusion or reaction of copper atoms into the thermoelectric semiconductor elements 1 and 12.
[0104]
The method for forming the electrode layers 7 and 8 made of copper and the reaction prevention layer made of gold is not limited to the DBC method, but may be provided by metallization such as plating. In the step of connecting the electrodes 7 and 8 to the elements 1 and 12, a solder connection method by reflow, a bonding method by a conductive adhesive, a thermal diffusion bonding method of a metalized electrode surface, an ultrasonic bonding method, and the like are performed. You may.
[0105]
The upper and lower supports 19 and 24 are made of a material that is easily deformed by thermal expansion or the like due to heating accompanying the operation of the thermoelectric conversion device 11. In order to suppress this deformation, the upper and lower supports 19 and 24 are required. If a copper layer and a gold-plated layer having a thickness of 100 μm are similarly provided on the outer side surface of the upper and lower electrodes 7 and 8 and also on the side opposite to the upper and lower supports 19 and 24, thermal expansion can be achieved. The deformation at the time can be easily suppressed.
[0106]
Also, by providing a copper layer or a gold plating layer that can be used as an electrode on the outer surface of each of the supports 19 and 24, these layers may be used as external terminals of the heating element. By using it as an electrode, it becomes possible to directly solder the thermoelectric conversion element and the cooling section.
[0107]
The ceramic plates that can be used as the supports 19 and 24 are preferably made of not only aluminum nitride but also materials having good heat conductivity such as zirconia, silicon nitride, alumina, and silicon carbide.
[0108]
Here, for example, the material is aluminum nitride, a ceramic substrate having a size of 5 mm in width, 5 mm in length, and 0.3 mm in height. By using these upper support 24 and lower support 19, By adding the element assembly 6, the upper and lower electrodes 7 and 8, and the like, a thermoelectric converter 11 having a width of 5 mm, a length of 5 mm, and a height of 2.0 mm can be manufactured.
[0109]
The ceramic substrate or the semiconductor substrate serving as the supports 19 and 24 may be thinner or thicker. The dimensions and logarithms of the elements 1 and 12 and the dimensions of each electrode in the thermoelectric conversion element 11 may be arbitrarily set. It can be changed. There is no problem even if the arrangement patterns of the n-type element material 1 and the p-type element material 12 of these thermoelectric conversion elements 11 are reversed.
[0110]
According to the present embodiment, in the n-type thermoelectric semiconductor element material 1A (or p-type thermoelectric semiconductor element material 12A) subjected to compression sintering, the low orientation degree region 1b inside the compression processing surface is formed along the compression processing surface. Since it is possible to obtain the thermoelectric semiconductor element material 1A or 12A having good thermoelectric conversion characteristics consisting of only the high-orientation degree region because it is cut and removed by a predetermined thickness, these thermoelectric semiconductor element materials having good thermoelectric conversion characteristics can be obtained. By using, the thermoelectric conversion device 11 with high orientation, high thermoelectric conversion performance and uniform high efficiency can be manufactured.
[0111]
In addition, since a plurality of element pairs 5 are bonded to form the plate-like element joined body 6, the shape of the plate-like element joined body 6 is maintained, handling becomes easy, and the thermoelectric conversion device is compared with that shown in FIG. Is easy to assemble.
[0112]
Second embodiment
In the present embodiment, as shown in FIGS. 6A to 7C, the element pairs 5 which are independent from each other are fixed on the lower electrode 8 formed on the lower support 19. It is the same as the first embodiment except that it is arranged at intervals.
[0113]
First, as shown in FIG. 6A, after the element pair 5 is manufactured through the steps of FIGS. 1A to 3H described above, the lower part formed in a predetermined pattern on the lower support 19 is formed. The element pairs 5 are arranged on the electrode 8 at fixed intervals and fixed.
[0114]
As a result, as shown in FIG. 6B, the plurality of element pairs 5 are arranged and fixed at intervals of, for example, 0.4 mm by the separation grooves 21 and 22, so that they are connected to each other by the lower electrode 8 on the lower support 19. can do.
[0115]
Next, as shown in FIG. 7C, the upper support 24 on which the upper electrode (not shown) is formed is fixed on the element pair 5 on the lower support 19 by being overlapped therewith, and connected to the upper electrode. The thermoelectric conversion device 11 incorporating the thermoelectric conversion element 2 is manufactured. Here, the upper electrode and the lower electrode 8 can be formed by plating or the like, and the connection of the upper electrode and the lower electrode 8 to the elements 1 and 12 is performed by soldering by reflow, a conductive adhesive, a metalized electrode, or the like. It may be performed by thermal diffusion bonding, ultrasonic bonding or the like of the surfaces.
[0116]
FIG. 8 shows the electrode patterns of the upper and lower electrodes 7 and 8. The upper electrode 7 is overlapped on the lower electrode 8 corresponding to each of the elements 1 and 12, and the upper electrode 7 and the lower electrode 8 are 2, for example, when used as a Peltier element, current flows from the n-type thermoelectric semiconductor element 1 to the p-type thermoelectric semiconductor element 12 on the side of the upper support 24 (heating element side) and absorbs heat, On the side of the lower support 19 (radiation side), the heat flows from the p-type thermoelectric semiconductor element 12 to the n-type thermoelectric semiconductor element 1 to generate heat (this is the same in the first embodiment).
[0117]
According to the present embodiment, the lower electrode 8 is provided directly on the upper surface or lower surface of the planar element assembly 6 in order to join the planar electrode assembly 6 after the lower electrode 8 is provided on the lower support 19 in advance. There is an advantage that it is not necessary to take measures to prevent the reaction between the electrode material and the semiconductor material at the time of forming the electrode as compared with the case of providing the electrode.
[0118]
In addition, in the present embodiment, the same operation and effect as those described in the first embodiment can be obtained.
[0119]
Third embodiment
In the present embodiment, as shown in FIGS. 9 to 16, a plurality of thermoelectric semiconductor element materials that have been compressed in the same manner as described above are attached to each other, and then cut to form a divided block. An element pair is formed on the lower electrode by fixing on the lower electrode material layer on the lower support, cutting the low orientation region in the divided block and part of the lower electrode material layer in this fixed state.
[0120]
In the present embodiment, as shown in FIG. 9A, through a manufacturing process similar to that shown in FIG. 1A, for example, a width of 4.5 mm, a length of 4.5 mm, and a height of 0 mm A thin plate-shaped n-type thermoelectric semiconductor element material 1A having a size of .95 mm and a p-type thermoelectric semiconductor element material 12A having the same size and shape as this are produced.
[0121]
Next, as shown in FIGS. 9 (b) and 10 (c), a plurality of these members are bonded together via an insulating material 3 having a thickness of, for example, 10 μm to form a bonded body block 14. Here, the a-axis direction is the vertical direction.
[0122]
Next, as shown in FIG. 10 (b), the bonded body block 14 is cut in the thickness direction of the thin plate with a dicing blade 15 or the like, and as shown in FIG. 11 (e), a divided block 29 having a predetermined width, for example, 1 mm width. Is prepared. Further, as shown in FIG. 11F, the divided block 29 is turned sideways so that the a-axis direction is present on the upper surface.
[0123]
Next, as shown in FIG. 12 (g), in order to fix the divided block 29, a lower support 19 made of, for example, silicon nitride having a width of 5 mm, a length of 5 mm, and a thickness of 0.3 mm is manufactured.
[0124]
On the lower support 19, for example, a lower electrode material layer 18 composed of a protective film (reaction preventing film) 16 made of gold and having a thickness of 1 μm and an electrode layer 17 made of copper and having a thickness of 100 μm is formed. It is formed by a DBC method or the like.
[0125]
Next, as shown in FIG. 12H, the divided block 29 is bonded and fixed on the lower electrode material layer 18 using solder or the like. Each of the element materials 1A and 12A has a high orientation region 1a and a low orientation region 1b, respectively.
[0126]
At this time, the direction in which the performance of the thermoelectric material is high (the a-axis direction) is automatically arranged in a direction orthogonal to the surface of the lower support 19.
[0127]
Next, as shown in FIG. 13 (i), the low-orientation region 1 b located at the center of the n-type and p-type thermoelectric semiconductor element materials 1 A and 12 A, together with a part of the electrode material layer 18, is It is cut and removed by a dicing blade 15 in parallel with the long side direction. In this cutting step, since each of the element materials 1A and 12A is firmly joined by the insulating material 3, the cutting can be performed well without causing the blade dicing of the dicing blade 15 and the chipping of the element material.
[0128]
Thereby, as shown in FIG. 13 (j), each element material 1A and 12A can be divided into a predetermined width together with the electrode material layer 18.
[0129]
By this cutting division step, each element joined body 20 in which the pair of the n-type element material 1A and the p-type element material 12A are integrated via the insulating material 3 is produced. Separation grooves 21 between the respective joined bodies 20 have an interval corresponding to the blade thickness of the dicing blade 15.
[0130]
As described above, when cutting the divided block 29 fixed on the lower support 19, the lower electrode 8 on the lower support 19 is cut and separated at the same time as performing this step. In order to reliably prevent a short circuit due to contact between the electrodes 8, it is unavoidable to cut a part of the lower support 19, which is a ceramic substrate, if possible. If possible, it is preferable not to cut the lower support 19 partially even in view of strength.
[0131]
Next, as shown in FIG. 14K, the joined body 20 is cut by a dicing blade 15 in parallel with the short side direction. Also in this cutting step, since each of the element materials 1A and 12A is firmly joined by the insulating material 3, the cutting step can be performed well.
[0132]
That is, the joined body 20 is cut in a direction orthogonal to the first dicing direction, so as to be isolated as the element pairs 5 and the electrode material layer 18 is also separated. The width of the cut portion may be, for example, 0.15 mm, the size of the isolated element pair 5 may be 0.4 mm in width, 0.4 mm in length, and 1.0 mm in height, or the number of element pairs 5 may be 32 pairs. (32 p-type elements 12 and 32 n-type elements 1) may be used.
[0133]
Thereby, as shown in FIG. 14 (l), the joined body 20 is separated by the separation grooves 21 and 22 into a pair with each of the n-type thermoelectric semiconductor element 1 and the p-type thermoelectric semiconductor element 12 having a predetermined dimension. In order to be divided together with the lower electrode material layer 18 provided below the element, these elements 1 and 12 are joined and integrated by the insulating material 3 and connected to each other by the lower electrode 8. Aggregates can be made.
[0134]
Next, as shown in FIG. 15 (m), for example, the upper electrode 7 having a predetermined pattern is formed on the lower surface of the upper support 24 made of silicon nitride having a width of 5 mm, a length of 5 mm and a height of 0.3 mm by a DBC method or the like. Formed. The electrode pattern 7 may be formed by, for example, dry etching, screen printing, plating, or the like (however, in the drawings, the upper electrode 7 is shown through the upper support 24 for easy understanding: And similar).
[0135]
Next, as shown in FIG. 15 (n), a lead wire 10 for wiring is connected to the lower electrode 8 to which the plurality of element pairs 5 are connected.
[0136]
Next, as shown in FIG. 15 (o), the upper support 24 on which the upper electrode pattern 7 is formed is connected to the plurality of element pairs 5 on the lower support 19, and the thermoelectric conversion element 2 incorporating the thermoelectric conversion element 2 is provided. The device 11 is manufactured. Here, as a method of connecting the electrodes, a solder connection method by reflow, a conductive adhesive, a thermal diffusion bonding of a metalized electrode surface, an ultrasonic bonding, or the like may be used.
[0137]
FIGS. 16A and 16B show the patterns of the upper and lower electrodes 7 and 8. In the state shown in the drawing, the upper electrode 7 is superimposed on the lower electrode 8 corresponding to each element, and each element is 1 and 12, the current flows from the n-type thermoelectric semiconductor element 1 to the p-type thermoelectric semiconductor element 12 on the side of the upper support 24 (the heating element side) on the side of the upper support 24 (heat generating element side), thereby absorbing heat, and On the side of the body 19 (radiation side), the heat flows from the p-type thermoelectric semiconductor element 12 to the n-type thermoelectric semiconductor element 1 to generate heat.
[0138]
In the formation pattern of the upper electrode 7, the element 1 of one row and the element 12 of the other row are connected to the end of the row of the element assembly adjacent to each other by the former or the latter. It is desirable to provide an upper electrode connection pattern 7a that connects the elements 1 and 12 between the columns in order to connect the elements 1 and 12 between each row.
[0139]
As described above, according to the present embodiment, it is characteristic that the plurality of n-type thermoelectric semiconductor elements 1 to 1 and the plurality of p-type thermoelectric semiconductor elements 12 to 12 are divided.
[0140]
In order to fabricate such a structure, a joint block 14 (see FIG. 10 (c)) composed of the relatively thick thermoelectric semiconductor element materials 1A and 12A is processed in advance and divided into thermoelectric semiconductor elements. After forming a divided block 29 of a joined body composed of the semiconductor element materials 1A and 12A and fixing the divided block 29 on the lower support 19 provided with the lower electrode material layer 18, the divided block 29 and the lower electrode material layer 18 are fixed. Is cut at a predetermined width and divided to form a pair of thermoelectric semiconductor elements 1 and 12 having a predetermined width easily and efficiently.
[0141]
Accordingly, as in the conventional example shown in FIG. 21, the elements processed into chips are arranged one by one by a robot or manually and individually assembled and joined, or a joined body of thin thermoelectric element materials is cut. As compared with the case where the thermoelectric semiconductor element materials 1 and 12 are thinned, the workability of assembling using the miniaturized elements is remarkably improved, and the production efficiency is greatly improved. Since it suffices to perform positioning and joining, different types of element materials are not erroneously arranged, and positioning can be reliably performed simply and inexpensively.
[0142]
In addition, since the element joined body 20 has sufficient strength and a sufficient thickness, cracking and chipping at the time of cutting can be eliminated, and cutting can be performed easily and reliably, enabling high-density element mounting. It becomes.
[0143]
In addition, if the plate thickness of the original p-type and n-type thermoelectric semiconductor element materials 1A and 12A is reduced, and the blade thickness of the dicing blade 15 is correspondingly reduced, the small-sized thermoelectric conversion element processed more finely. Can be created.
[0144]
In addition, in the present embodiment, the same operation and effect as those described in the first embodiment can be obtained.
[0145]
Fourth embodiment
As shown in FIGS. 17 (a) to 18 (d), this embodiment employs a physically or electrically independent element pair on the lower support 19, as in FIG. 15 (n). 5 and a lower electrode 8 disposed therebelow are prepared. Subsequently, a resin is filled between the element pair 5 and an upper electrode is placed on the element pair 5 exposed on the resin when the filling is performed. Provide.
[0146]
First, as shown in FIG. 17A, the plurality of isolated element pairs 5 and the lower electrode 8 below the isolated element pairs 5 are formed by performing the processes of FIGS. 9A to 14L described above. One that is placed and fixed on the support 19 is manufactured.
[0147]
Next, as shown in FIG. 17B, after connecting the lead wires 10 to the lower electrodes 8 of the predetermined element pairs 5, respectively, a resin 25 such as an epoxy resin is filled in the separation grooves 21 and 22 between the element pairs 5. Fill and embed between each element pair 5. In this case, the end surfaces of the elements 1 and 12 are exposed on the upper surface of the resin 25.
[0148]
Next, as shown in FIG. 18C, the material of the upper electrode 7, for example, copper (Cu) is applied on the resin 25 and the end faces of the elements 1 and 12 by a sputtering method or a vapor deposition method. Thereafter, by patterning, the upper electrode 7 and the upper electrode pattern 7a connected to each of the elements 1 and 12 are formed in the same pattern as the upper electrode pattern shown in FIG. 16B, thereby completing the thermoelectric conversion device 11. I do.
[0149]
In the present embodiment, as shown in FIG. 18C, the separation grooves 21 and 22 between the element pairs 5 are filled with the resin 25, and the entire element pairs 5 are solidified with the resin 25. The strength as the conversion element is improved, and the heat insulation between the element pair 5 can be secured.
[0150]
Further, since the upper electrode 7 and the like can be formed on the end face of each element pair 5 exposed on the resin 25, the resin 25 can function as a substrate and a protection plate for forming the upper electrode 7 and the like. This makes it possible to eliminate the need for the upper support, and in that case, it is possible to reduce the total thickness of the thermoelectric converter 11 to make it thinner.
[0151]
Further, since the upper electrode 7 can be provided on the upper support 24, a heating element (not shown) can be directly disposed and fixed on the upper electrode 7, so that the heat absorption efficiency can be improved. Further, since a part of the lower electrode 8 protrudes from the lower part of the element pair 5 to the side surface of the lower support 19, it is easy to connect the lead wire 10 to this part.
[0152]
Further, as shown in FIG. 18D, when a heating element (not shown) is fixed on the thermoelectric conversion element 11, for example, a thermoelectric element is insulated to insulate the thermoelectric conversion element 11 from the heating element. A ceramic plate such as alumina may be provided on the upper part of the conversion element 11 or a polymer sheet 26 such as polyethylene terephthalate or polyimide may be integrally formed.
[0153]
Here, the polymer sheet 26 is a flexible material but has a low thermal conductivity, so that the heat distribution may be uneven in the plane of the thermoelectric conversion element 11 when the thermoelectric conversion element 11 is operated.
[0154]
In order to prevent this, in order to dissipate heat uniformly in the plane of the thermoelectric conversion element 11, for example, a high heat conductive sheet 27 such as a graphite sheet having good heat conductivity, a copper foil and an aluminum foil is replaced with a polymer sheet. Preferably, the upper support 24 is formed by a structure sandwiched between the polymer sheets 26 over substantially the entire surface of the upper support 24.
[0155]
In addition, in the present embodiment, the same operation and effect as those described in the first embodiment can be obtained.
[0156]
The embodiments of the present invention described above can be further modified based on the technical idea of the present invention.
[0157]
For example, the cutting amount can be minimized by changing the compression processing conditions according to the size of the element material or the like.
[0158]
Further, in the above-described example, the n-type thermoelectric semiconductor and the p-type thermoelectric semiconductor are bonded, but in the bonding step, the order of arrangement of these thermoelectric semiconductors may be reversed from that described above. . Further, the pattern of the electrodes formed on the heat-side support or the heat-absorbing side support may be variously changed, and the size, the number of pairs, and the forming method of the thermoelectric semiconductor elements may also be various.
[0159]
In addition, each component of the thermoelectric conversion device, for example, the thermoelectric semiconductor element, as well as the adhesive and the material and shape of the electrode material for bonding the elements, the method of forming the electrode on the thermoelectric element or the support, the thermoelectric semiconductor element The cutting means and cutting method of the material may be changed.
[0160]
Further, in the above-described example in which the polymer sheet having the high thermal conductive sheet is provided on the surface side of the thermoelectric conversion device, only the polymer sheet may be provided, or the polymer sheet may not be provided.
[0161]
The thermoelectric converter is, for example, in the state shown in FIG. 4 (k). However, even in the state shown in FIG. 4 (j), that is, without the support, the thermoelectric converter having the skeleton structure shown in FIG. It can be provided as a conversion device.
[0162]
In the above-described example, the Peltier element suitable for a heat pump or the like has been described. However, it is needless to say that the present invention can be applied to a Seebeck element as a power generation element.
[0163]
【The invention's effect】
As described above, according to the present invention, in the compression-processed body of the thermoelectric semiconductor material, to have a step of removing a region inside the compression-processed surface by a predetermined thickness along the compression-processed surface, A low-orientation region having insufficient compressibility in the compression-processed body is removed, and a highly-oriented thermoelectric semiconductor having good compressibility and thermoelectric conversion characteristics can be obtained. Therefore, a thermoelectric conversion element or device can be manufactured with good workability by dividing, joining, or the like the thermoelectric semiconductor having a high degree of orientation and a small variation in performance.
[Brief description of the drawings]
FIG. 1 is a perspective view showing one step of a method for manufacturing a thermoelectric conversion device according to a first embodiment of the present invention.
FIG. 2 is a perspective view showing another process of the same.
FIG. 3 is a perspective view showing another process of the same.
FIG. 4 is a perspective view showing another process and a perspective view showing a completed thermoelectric converter.
FIG. 5 is a graph (A) showing a correlation characteristic between the degree of orientation of the sintered or press-formed body before cutting and the distance in the sheet thickness direction, and the degree of orientation of the sintered or pressed body after cutting and the sheet. It is a graph (B) which shows the correlation characteristic with distance in the thickness direction.
FIG. 6 is a perspective view showing one step of a method for manufacturing a thermoelectric conversion device according to a second embodiment of the present invention.
FIG. 7 is a perspective view of the completed thermoelectric converter.
FIG. 8 is a plan view showing the same electrode pattern.
FIG. 9 is a perspective view showing one step of a method for manufacturing a thermoelectric conversion device according to a third embodiment of the present invention.
FIG. 10 is a perspective view showing another process of the same.
FIG. 11 is a perspective view showing another process of the same.
FIG. 12 is a perspective view showing another process of the same.
FIG. 13 is a perspective view showing another process of the same.
FIG. 14 is a perspective view showing another process of the same.
FIG. 15 is a perspective view showing another process and a perspective view of a completed thermoelectric converter.
FIG. 16 is a plan view showing the same electrode pattern.
FIG. 17 is a perspective view showing one step of a method for manufacturing a thermoelectric conversion device according to a fourth embodiment of the present invention.
FIG. 18 is a perspective view of the completed thermoelectric converter and a partially enlarged sectional view thereof.
FIG. 19 is a perspective view of a conventional thermoelectric converter.
FIG. 20 is a schematic view (perspective, front, side, top, and bottom) of another thermoelectric conversion element.
FIG. 21 is a main part front view showing the method of arranging the thermoelectric elements when assembling the thermoelectric conversion elements.
FIG. 22 is a perspective view showing one step of a method of manufacturing still another thermoelectric conversion device.
FIG. 23 is a perspective view showing another process of the same.
FIG. 24 is a perspective view showing another step of the same.
FIG. 25 is a perspective view showing another process and a perspective view of a completed thermoelectric converter.
FIG. 26 is a perspective view showing a hot press or electric current sintering step.
FIG. 27 is a perspective view showing one step of a method for manufacturing the thermoelectric conversion device, and a schematic diagram showing changes in the thermoelectric conversion material due to compression sintering.
FIG. 28 is a molecular structural diagram of the thermoelectric conversion material including van der Waals force coupling.
FIG. 29 is a perspective view of a sintered or press-formed body after compression sintering, and an X-ray diffraction spectrum in a plate thickness direction.
FIG. 30 is a graph showing a correlation characteristic between the degree of orientation of a sintered or pressed product and the distance in the plate thickness direction.
[Explanation of symbols]
1 ... n-type thermoelectric semiconductor element, 1A ... n-type thermoelectric semiconductor element material,
1a: high orientation region, 1b: low orientation region, 2: thermoelectric conversion element, 3: insulating material,
5: element pair, 6: plate-like element assembly, 7: upper electrode,
7a: Upper electrode connection pattern, 8: Lower electrode, 10: Lead wire,
11 thermoelectric conversion device, 12 p-type thermoelectric semiconductor element,
12A: p-type thermoelectric semiconductor element material; 14: bonded block;
15: dicing blade, 16: protective film, 17: electrode layer,
18 lower electrode material layer, 19 lower support, 20 element joined body,
21, 22: separation groove, 24: upper support, 25: resin, 26: polymer sheet,
27: High thermal conductive sheet, 28: Sintered or pressed body, 29: Divided block

Claims (26)

A step of forming a compression-processed body having a predetermined shape through at least a step of compressing the thermoelectric semiconductor material to form a compression-processed body; of the compression-processed body, an area inside the compression-processed surface is formed on the compression-processed surface; Removing a predetermined thickness along the same. 2. The thermoelectric semiconductor according to claim 1, wherein the compression-processed surface side is a high-orientation region, and the compression-processed body in which the inside is a low-orientation region removes the low-orientation region parallel to the compression-processed surface. Production method. The method for manufacturing a thermoelectric semiconductor according to claim 2, wherein the highly oriented region has a degree of orientation of 0.8 or more in relative ratio. 4. The method of manufacturing a thermoelectric semiconductor according to claim 2, wherein a thickness of the thermoelectric semiconductor including the highly oriented region is set to 0.4 mm to 2 mm or less. 5. The method for manufacturing a thermoelectric semiconductor according to claim 1, wherein the compression-processed body is cut in a direction intersecting with the compression-processed surface, and the cut piece is subjected to the removing step. The method for producing a thermoelectric semiconductor according to claim 1, wherein a thermoelectric semiconductor ingot is produced by a solidification method, the ingot is powdered, and the powder is compression-sintered to obtain the compact. A step of forming a compression-processed body having a predetermined shape through at least a step of compressing the thermoelectric semiconductor material to form a compression-processed body; Forming a thermoelectric semiconductor by removing the thermoelectric semiconductor by a predetermined thickness along the same; joining the first and second thermoelectric semiconductors obtained as the thermoelectric semiconductor and having different conductivity types via an insulating material to form a thermoelectric semiconductor joined body A step of dividing the thermoelectric semiconductor joined body to form an element joined body; a step of joining a plurality of the element joined bodies and forming a first electrode and a second electrode on both surfaces thereof, respectively. Manufacturing method of thermoelectric conversion element or device. The method for manufacturing a thermoelectric conversion element or device according to claim 7, wherein a support is formed on at least one surface of the first and second electrodes. The method for manufacturing a thermoelectric conversion element or a device according to claim 7, wherein a thermoelectric semiconductor ingot is produced by a solidification method, the ingot is powdered, and the powder is compression-sintered to obtain the compact. A step of compressing at least the thermoelectric semiconductor material to form a compacted body; and joining the first and second compacted bodies obtained as the compacted body having different conductivity types via an insulating material. Forming a bonded body; cutting the thermoelectric semiconductor bonded body in a direction intersecting with the compression-processed surface to form an element bonded body; and bonding the element on a first support via a first electrode. Fixing the body; of the thermoelectric semiconductor of the element assembly, removing a region inside the compression-processed surface by a predetermined thickness along the compression-processed surface and dividing the region into a pair of thermoelectric semiconductor element rows; A method of manufacturing a thermoelectric conversion element or device, the method also including a step of dividing the electrodes into respective rows. The method for manufacturing a thermoelectric conversion element or device according to claim 10, wherein the thermoelectric semiconductor element row is divided in a direction intersecting the element row and separated into individual thermoelectric semiconductor elements. The method for manufacturing a thermoelectric conversion element or device according to claim 11, wherein the second support is joined to the thermoelectric semiconductor element via the second electrode. The thermoelectric device according to claim 7, wherein the low-orientation region is removed in parallel with the compression-processed surface in the compression-processed body in which the compression-processed surface side is a high-orientation region and the inside is a low-orientation region. A method for manufacturing a conversion element or device. 14. The method for manufacturing a thermoelectric conversion element or device according to claim 13, wherein the highly oriented region has a degree of orientation of 0.8 or more in relative ratio. The method for manufacturing a thermoelectric conversion element or a device according to claim 13 or 14, wherein the thickness of the first and second thermoelectric semiconductors composed of the highly oriented region is set to 0.4 mm to 2 mm or less. The method for manufacturing a thermoelectric conversion element or device according to claim 7, wherein the compression-processed body is cut in a direction intersecting with the compression-processed surface, and the cut step is performed on the cut piece. The method for producing a thermoelectric conversion element or a device according to claim 10, wherein a thermoelectric semiconductor ingot is produced by a solidification method, the ingot is powdered, and the powder is compression-sintered to obtain the compact. The method for manufacturing a thermoelectric conversion element or a device according to claim 10, wherein after the first electrode and the second electrode are respectively formed on the element assembly, the support is fixed on these electrodes. The method for manufacturing a thermoelectric conversion element or a device according to claim 10, wherein the element assembly is fixed on the support after the first electrode or the second electrode is formed on the support. The method according to claim 12, wherein an insulating material is filled between the thermoelectric semiconductor elements, and the second electrode is formed on the exposed thermoelectric semiconductor elements. The method for manufacturing a thermoelectric conversion element or a device according to claim 10, wherein the two thermoelectric semiconductor elements having different conductivity types or the same conductivity type are arranged to face each other via a division groove. The element assemblies are arranged in a plurality of rows, and the first thermoelectric semiconductor elements in one row and the second thermoelectric semiconductor elements in the other row are arranged on the side of the second electrode at the ends of the element assembly rows adjacent to each other. The method for manufacturing a thermoelectric conversion element or a device according to claim 10, wherein the first and second thermoelectric semiconductor elements are connected over a row of the first or second thermoelectric semiconductor elements. The method for manufacturing a thermoelectric conversion element or device according to claim 7 or 10, wherein a reaction prevention layer is provided between the first electrode or the second electrode and the element assembly. The method for manufacturing a thermoelectric conversion element or device according to claim 7 or 10, wherein a support body having a high thermal conductor integrated therein is disposed at least on the side of the second electrode of the element assembly. The method for manufacturing a thermoelectric conversion element or device according to claim 7, wherein a heating element is disposed on the second electrode side, and the first electrode side is a heat radiation side. The method for manufacturing a thermoelectric conversion element or device according to claim 7 or 10, wherein the thermoelectric conversion element is configured as a Peltier element or a Seebeck power generation element.

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