JP2012028388A - Method for manufacturing thermoelectric conversion module - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a thermoelectric conversion module composed of multiple thermoelectric transducers by forming multiple thermoelectric conversion material chips collectively on a substrate by electrolytic deposition.SOLUTION: Electrodes are arranged on an insulated substrate 10 and an insulation mask 14 made of resin which is soluble in an organic solvent are disposed between the electrodes. A mold plate 18 having conductive film all over the surface on one side thereof and through holes 20 at positions where chips are going to be formed is put in position, and the electrodes are electrolytically deposited as cathode electrodes in an electrolyte solution via the conductive film, thereby filling the through holes with a thermoelectric conversion material 32 to form chips, with the mold plate having the conducive film and the insulation mask removed. These steps are carried out in order for P-type and N-type thermoelectric conversion materials to produce a P-type half body which has electrodes and P-type chips arranged on an insulated substrate and an N-type half body which has electrodes and N-type chips arranged on another insulated substrate. The P-type half body and the N-type half body are combined to produce a thermoelectric conversion module composed of a combination of multiple thermoelectric transducers.

Description

  The present invention relates to a method for manufacturing a thermoelectric conversion module by forming a large number of chips of a thermoelectric conversion material on a substrate at once.

  The thermoelectric conversion material is an energy material that performs direct conversion between thermal energy and electric energy based on two basic thermoelectric effects, the Seebeck effect and the Peltier effect.

  Thermoelectric power generation devices using thermoelectric conversion materials have a simple structure, robustness, high durability, no moving parts, easy microfabrication, no maintenance, and reliability compared to conventional power generation technology There are many advantages such as high life, long life, no noise, no pollution and low temperature waste heat can be used.

  Compared to conventional compression cooling technology, thermoelectric cooling devices using thermoelectric conversion materials do not require chlorofluorocarbon, do not cause contamination, are easily downsized, have no moving parts, and do not generate noise. is there.

  Therefore, especially in recent years, energy and environmental issues have become more serious, such as aviation / space, national defense construction, geological and meteorological observation, medical hygiene, microelectronics, etc. Is expected to be put to practical use for a wide range of applications.

  Conventionally, P-type and N-type bulk thermoelectric conversion materials are manufactured by powder sintering and melting and solidification, and this is diced by machining to form several mm square P-type chips and N-type chips. A P-type chip and an N-type chip are arranged in a predetermined pattern on the top, and the chips on each substrate are joined so as to be sandwiched between both substrates, thereby forming a large number of thermoelectric conversion elements between the two substrates.

  In this specification, a small piece (for example, several mm square) of a thermoelectric conversion material itself is formed by joining a “chip” (thermoelectric conversion material chip) and a pair of P-type and N-type chips via electrodes. An “element” (thermoelectric conversion element) and an element group in which a large number of elements are combined are called a “module” (thermoelectric conversion module). In general, since the power generation amount of each element is small, a large number of elements are combined and put into practical use as an element group, that is, a module.

  Here, if an element pattern can be obtained directly by forming a large number of chips on a substrate by electrolytic deposition, the manufacturing cost of the element or module can be greatly reduced, which is very desirable.

  However, since the electrodes are discretely arranged on the substrate, it is not practical to collectively form each chip on each electrode by electrolytic deposition.

  That is, (1) In order to collectively form a large number of chips by electrolytic deposition, it is necessary to electrically connect discretely arranged electrodes on the substrate. (2) The conductive material for this electrical connection There was a problem that electrolytic deposition also occurred in the exposed portion, and (3) the conductive material for electrical connection had to be removed after use.

  Patent Document 1 discloses a method for producing a thermoelectric conversion material by electrolytic deposition. However, control of the crystal orientation of the thermoelectric conversion material formed by electrolytic deposition and a method of creating a multilayer film have been proposed, but a module can be manufactured by forming a large number of chips and elements in a batch from the thermoelectric conversion material. There is no disclosure about.

JP 2001-7408 A

  An object of the present invention is to provide a method for collectively manufacturing a thermoelectric conversion module including a plurality of thermoelectric conversion elements by forming a large number of thermoelectric conversion material chips on a substrate by electrolytic deposition.

To achieve the above object, the present invention is a method of manufacturing a thermoelectric conversion module in which a large number of thermoelectric conversion elements composed of a pair of thermoelectric conversion material chips of P type and N type are combined,
(1) a step of arranging a large number of electrodes of equal thickness on an insulating substrate in a predetermined pattern;
(2) An insulating mask made of a resin that is easily dissolved in an organic solvent and having the same thickness as the electrode is disposed so as to fill the space between the electrodes, and the upper surface of the electrode and the upper surface of the insulating mask are the same. Flattening process,
(3) A step of providing a mold plate having a conductive film on one whole surface and having a chip-shaped through hole at a portion corresponding to a chip formation scheduled position on the electrode arranged on the insulating substrate;
(4) Align each through hole of the mold plate at each chip formation planned position of each electrode, and bring the conductive film on the one surface of the mold plate into close contact with the electrode on the insulating substrate, Fixing the mold plate,
(5) Electrodeposition of each electrode as a cathode electrode through the conductive film in an electrolytic solution, whereby the chip-shaped through-holes of the mold plate are formed on the multiple electrodes on the insulating substrate. A step of filling a hole with the thermoelectric conversion material to form a chip of the thermoelectric conversion material on each electrode;
(6) a step of removing the mold plate, and (7) a step of dissolving and removing the resin insulating mask with an organic solvent,
Are sequentially performed on the insulating substrate to form a half body of the thermoelectric conversion module in which the electrodes and the chips on the insulating substrate are arranged on the P-type and N-type thermoelectric conversion materials. A P-type half with an electrode and a P-type thermoelectric conversion material chip arranged thereon, and an N-type half with an electrode and an N-type thermoelectric conversion material chip arranged on another insulating substrate are prepared. And
A thermoelectric conversion in which a P-type thermoelectric conversion material chip and an N-type thermoelectric conversion material chip constitute a pair by combining the P-type half and the N-type half with their chip arrangement surfaces facing each other. Provided is a method for manufacturing a thermoelectric conversion module, characterized by manufacturing a thermoelectric conversion module in which a large number of elements are combined.

  According to the present invention, (4) each through hole of the mold plate is aligned with each chip formation planned position of each electrode, and the conductive film on the one surface of the mold plate is connected to the electrode on the insulating substrate. In the step (5), a voltage is applied to all electrodes on the insulating substrate through the conductive film, and a thermoelectric conversion material chip is formed by electrolytic deposition on each electrode. In the step (7), the insulating mask made of resin can be dissolved and removed with an organic solvent, and this step was obtained for each of the P-type and N-type thermoelectric conversion materials. By combining the P-type and N-type halves, a thermoelectric conversion module composed of a large number of thermoelectric conversion elements can be manufactured in a lump.

FIG. 1 shows a state in which electrodes are arranged on an insulating substrate according to a first embodiment of the method of the present invention. FIG. 2 shows a state in which an insulating mask is arranged so as to fill between the electrodes on the insulating substrate in the next step of FIG. 1 according to the first embodiment of the method of the present invention. FIG. 3 shows (1) a mold plate and (2) this for forming a chip by electrolytically depositing a thermoelectric conversion material on each electrode in the next step of FIG. 2 according to the first embodiment of the method of the present invention. The state which has arrange | positioned the mold board on the insulated substrate is shown. FIG. 4 shows the first embodiment of the method of the present invention, in the next step of FIG. 3, (1) is a state in which electrolytic deposition is performed on a substrate on which a mold plate is arranged, and (2) is a mold plate by electrolytic deposition. (3) is a cross-sectional view taken along line III-III in (2), and (4) is a nickel plating film on the exposed surface of the thermoelectric conversion material using another electrolytic solution. The state which formed is shown. FIG. 5 shows a first embodiment of the method of the present invention, in the next step of FIG. 4, after electrolytic deposition, (1) P-type half with the mold plate (with conductive film) and insulating mask removed, and (2) An N-type half is shown. FIG. 6 shows the thermoelectric conversion according to the first embodiment of the method of the present invention, in the next step of FIG. Shows the completed state of the module. FIG. 7 is a cross-sectional view showing a method for electrolytically depositing a chip according to the second embodiment of the method of the present invention. FIG. 8 is a sectional view showing a modification of the second embodiment of the method of the present invention.

[First Embodiment]
A first embodiment of the method of the present invention will be described with reference to FIGS.

  First, as shown in FIG. 1, a large number of electrodes 12 having the same thickness are arranged in a predetermined pattern on an insulating substrate 10. Although (1) and (2) are P-type substrates and (3) and (4) are N-type substrates, P and N may be reversed. (1) is a plan view, (2) is a sectional view taken along line II-II in (1), (3) is a plan view, and (4) is a sectional view taken along line IV-IV in (2). The same applies to FIG.

  Next, as shown in FIG. 2, an insulating mask 14 made of a resin that is easily dissolved in an organic solvent and having the same thickness as the electrode 12 is disposed so as to fill a space between the electrodes 12. The upper surface and the upper surface of the insulating mask 14 are flush with each other. The insulating mask 14 is made of a resin that is easily dissolved in an organic solvent, so that it can be easily removed in a subsequent process.

Next, as shown in FIG. 3 (1), the entire surface is formed by sputtering or the like, provided with a conductive film 16, and corresponds to a chip formation planned position on the electrode 12 arranged on the insulating substrate 10. the mold plate 18 having the through-hole 20 of the tip shape site is prepared, and the respective through holes 20 of the mold plate 18 aligning and in each chip formation planned position of each electrode 12 as shown in FIG. 3 (2) Then, the conductive film 16 on one surface of the mold plate 18 is brought into close contact with the electrode 12 on the insulating substrate 10, and the fixed mold plate 18 is fixed by the fixing jig 22. A power supply lead 24 for electrolytic deposition is connected to the conductive film 16. A fixed assembly is indicated at 19.

  Next, as shown in FIG. 4A, electrolytic deposition is performed in the electrolytic solution 26 with each electrode 12 as a cathode electrode through the conductive film 16. In the electrolytic solution 26, the fixed assembly 19 is disposed as a negative electrode, and a counter electrode 28 such as platinum is used as a positive electrode, and power is supplied from a DC power source 30.

As a result, as shown in FIG. 4 (2) plan view and (3) cross-sectional view (line III-III in (2)), the chip shape of the mold plate 18 is formed on the numerous electrodes 12 on the insulating substrate 10. Each through hole 20 is filled with a thermoelectric conversion material, and a chip 32 of the thermoelectric conversion material is formed on each electrode 12.
That is, as shown in the cross-sectional view of FIG. 4 (3), the conductive film 16 formed on the entire one surface of the mold plate 18 is in close contact with the electrode 12 at a portion other than the through-hole 20, and many The electrodes 12 are electrically connected to each other through the conductive film 16. Therefore, the current for electrolytic deposition is collectively supplied from the power supply leads 24 to the multiple electrodes 12 through the conductive film 16, and the chips 32 are collectively formed on the electrodes 12.

  Further, desirably, as shown in FIG. 4 (4), an electrolytic plating film 34 of Ni or the like is formed on the surface of the chip 32 in the through hole 20 of the mold plate 18 in another electrolytic solution. Thereby, when a P-type semiconductor and an N-type semiconductor are combined using a bonding material, the bondability between the chip and the electrode can be improved.

  Next, as shown in FIG. 5, the mold plate 18 (with the conductive film 16) and the insulating mask 14 are removed. The insulating mask 14 can be easily removed by dissolving a resin as a mask material with an organic solvent.

  The steps of FIGS. 1 to 5 are sequentially performed to form thermoelectric conversion module halves 36 and 38 in which the electrodes 12 and the chips 32 thereon are arranged on the insulating substrate 10. That is, the above process is performed on the P-type and N-type thermoelectric conversion materials, and the P-type half 36 in which the electrodes 12 and the P-type thermoelectric conversion material chips 32 are arranged on one insulating substrate 10 is separated from the P-type half 36. The N-type half body 38 in which the electrode 12 and the N-type thermoelectric conversion material chip 32 are arranged on the insulating substrate 10 is prepared.

  Next, as shown in FIG. 6, by combining the P-type half 36 and the N-type half 38 with their chip arrangement surfaces facing each other, the P-type thermoelectric conversion material chip, the N-type thermoelectric conversion material chip, Manufactures a thermoelectric conversion module 40 in which a large number of thermoelectric conversion elements configured in pairs are combined.

[Second Embodiment]
In the second embodiment, in addition to the configuration of the first embodiment, the portion other than the chip formation planned position on the electrode is covered with another insulating mask.

  When the adhesion between the conductive film 16 of the mold plate 18 and the electrode 12 cannot be obtained, the electrolyte enters the contact surface between the conductive film 16 and the electricity 12, and the thermoelectric conversion material is not located at the original chip formation planned position. There is a risk of precipitation. In order to prevent this, the part other than the chip formation planned position on the electrode is covered with another insulating mask.

The second embodiment will be described with reference to FIG.
After the step of FIG. 2, as shown in FIG. 7 (1), the portion other than the chip formation planned position 5 of the electrode 12 is further covered with a second insulating mask 42.

  Next, as shown in FIG. 7B, the mold plate 18 is fixed by aligning the through hole 20 with the chip formation planned position 5. In this state, the electrode 12 and the conductive film 16 are separated from each other by the thickness of the second insulating film 42 and are not electrically conductive.

  When the electrolytic deposition treatment is started, as shown in FIG. 7 (3), electrolytic deposition starts from the cross section of the conductive film 16, and the electrodeposition portion 32A grows and is connected to the electrode 12, and the conductive film 16 And the electrode 12 become conductive.

If the electrolytic deposition process is further continued, the electrodeposition portion continues to grow, and the chip 32 is formed in the through hole 20 as in the case of the first embodiment.
The subsequent processing is the same as in the first embodiment.

[Modification of Second Embodiment]
FIG. 8 shows a modification of FIG. 7, and as shown in FIG. 8A, a part 5 </ b> A other than the chip formation planned position 5 of the electrode 12 is not covered with the second insulating film 42. Is the case.

  In this case, when the through hole 20 is aligned with the chip formation planned position 5 and the mold plate 18 is fixed, as shown in FIG. 8 (2), a part 5A of the electrode 12 other than the chip formation planned position 5 is molded. The plate 18 and the conductive film 16 protrude from the end face of the second insulating film 42, and a space A remains between the conductive film 16 and the electrode 12.

  Even in such a state, when the electrolytic deposition treatment is started, as shown in FIG. 8 (3), electrolytic deposition starts from the cross section of the conductive film 16, and the electrodeposition portion 32 </ b> A grows. As a result, the conductive film 16 and the electrode 12 become conductive.

If the electrolytic deposition process is further continued, the electrodeposition portion continues to grow, and the chip 32 is formed in the through hole 20 as in the case of the first embodiment.
The subsequent processing is the same as in the first embodiment.

  Examples of the first embodiment of the present invention will be described.

  A 200 μm thick copper plate is soldered on the alumina substrate 10. This copper plate is patterned on the thermoelectric conversion element electrode 12 by etching. As a result, as shown in FIG. 1, P-type substrates (1) (2) and N-type substrates (3) (4) on which electrodes 12 are arranged for P-type chip formation and N-type chip formation are prepared. . Instead of the alumina substrate 10, ceramics such as magnesia, silicon nitride, and silicon carbide, and insulating materials such as resin materials can be used. As a material of the electrode 12, metal materials such as Al, Fe, Ag, Au, and stainless steel can be used instead of copper (Cu).

  Next, as shown in FIG. 2, an insulating mask 14 is disposed so as to fill a large number of electrodes 12, and the upper surface of the electrode 12 and the upper surface of the insulating mask 14 are flush with each other. The insulating mask 14 is made of a resin that can be easily dissolved and removed with an organic solvent.

  The insulating mask 14 can be made of polyimide, epoxy, acrylic, phenolic resin, etc., and has a method of applying an ink resist material by screen printing, a method of using a pre-patterned dry film, and photosensitivity. It can be formed by a method of curing an exposed portion with a photoresist and washing away an uncured portion.

  Next, as shown in FIG. 3A, a conductive film 16 is provided on one entire surface, and a chip-shaped portion is formed at a position corresponding to a chip formation planned position on the electrode 12 arranged on the insulating substrate 10. A mold plate 18 having a through hole 20 is prepared.

  Next, as shown in FIG. 3 (2), each through hole 20 of the mold plate 18 is aligned with each chip formation planned position of each electrode 12, and the conductive film 16 on one surface of the mold plate 18 is insulated. The mold plate 18 is fixed in close contact with the electrode 12 on the substrate 10 to obtain an assembly 19 for electrolytic deposition. The mold plate 18 has a chip shape / dimension (for example, 2 mm square) after forming a conductive film 16 as a power supply film for electrolytic deposition on one whole surface of a resin material or the like by a film forming method such as sputtering. The through hole 20 is formed and produced. The resin material or the like is preferably a highly peelable material such as PTFE, but is not limited thereto, and other resins and ceramics can also be used. Although a rectangular parallelepiped is illustrated as the shape of the chip (through hole), other shapes may be used.

  Next, electrolytic deposition is performed as shown in FIG. 4 (1), and chips 32 are formed in the through holes 20 as shown in FIGS. 4 (2) and (3). The electrodeposition assembly 19 is a negative electrode, and a noble metal such as platinum is a positive electrode. By energizing the conductive film 16 of the mold plate 18, the chip 32 is formed on the surface of the electrode 12 exposed in the through hole 20. The P-type chip 32 and the N-type chip 32 are formed on different substrates 10.

As an example, when producing a thermoelectric conversion module of a BiTe thermoelectric conversion material, a BiTe system is obtained by performing electrolytic deposition at a constant potential using a nitric acid solution in which Bi ₂ O ₃ and TeO ₂ are dissolved as the electrolytic solution 26. A chip 32 of thermoelectric conversion material can be formed. The composition ratio of Bi and Te can be adjusted by the electrodeposition potential to make a P-type chip and an N-type chip separately. P-type and N-type composition adjustments can also be made by dissolving metal ions as dopants in the electrodeposition bath. If the electrodeposition is performed by changing the combination of other metal salts and the electrolytic solution 26, the chips 32 of thermoelectric conversion materials having various compositions can be formed.

  If necessary, a protective film 34 such as a Ni electrolytic plating film may be formed on the top surface of the formed chip 32 as shown in FIG.

  Next, as shown in FIG. 5, the mold plate 18 (with the conductive mask 16) and the insulating mask 14 are removed. This is performed by pulling out the mold plate 18 (with the conductive mask 16) from the chip 32 on the substrate 10 and then dissolving and removing the resin insulating mask 14 with an organic solvent such as toluene or xylene. Thereby, (1) P-type half 36 and (2) N-type half 38 are obtained.

  Next, as shown in FIG. 6, the P-type half 36 and the N-type half 38 are bonded to each other with their chip arrangement surfaces facing each other, and the thermoelectric conversion module 40 is manufactured.

  For this purpose, first, a solder paste (not shown) is applied to the top surface of the chip 32 (on the Ni protective film 34 in this example) by screen printing. Next, using the alignment jig, the top surface of the P-type chip 32 of the P-type half 36 and the electrode of the N-type half 38 are aligned, and the top surface of the N-type chip 32 of the N-type half 38 And the electrode of the P-type half 36 are aligned and fixed. Next, the fixed assembly is heat-treated at a temperature higher than the melting temperature of the solder to bond each half chip 32 to the other half electrode 12. As a result, the thermoelectric conversion module 40 in which a large number of thermoelectric conversion elements configured by forming pairs of P-type thermoelectric conversion material chips and N-type thermoelectric conversion material chips is obtained.

  ADVANTAGE OF THE INVENTION According to this invention, the method of collectively manufacturing the thermoelectric conversion module which consists of many thermoelectric conversion elements by forming many thermoelectric conversion material chips | tips collectively on a board | substrate by electrolytic deposition is provided.

DESCRIPTION OF SYMBOLS 10 Insulation board | substrate 12 Electrode for thermoelectric conversion elements 14 Insulation mask 16 Conductive film 18 Mold board 20 Through-hole 22 Fixing jig 24 Feeding lead 26 Electrolytic solution 28 Counter electrode 30 DC power supply 32 Chip (chip of thermoelectric conversion material)
34 Electrolytic plating film (protective film)
36 P-type half 38 N-type half 40 Thermoelectric conversion module 42 Another (second) insulation mask

Claims (2)

A method of manufacturing a thermoelectric conversion module in which a large number of thermoelectric conversion elements composed of a pair of P-type and N-type thermoelectric conversion material chips are combined,
(1) a step of arranging a large number of electrodes of equal thickness on an insulating substrate in a predetermined pattern;
(2) An insulating mask made of a resin that is easily dissolved in an organic solvent and having the same thickness as the electrode is disposed so as to fill the space between the electrodes, and the upper surface of the electrode and the upper surface of the insulating mask are the same. Flattening process,
(3) A step of providing a mold plate having a conductive film on one whole surface and having a chip-shaped through hole at a portion corresponding to a chip formation scheduled position on the electrode arranged on the insulating substrate;
(4) Align each through hole of the mold plate at each chip formation planned position of each electrode, and bring the conductive film on the one surface of the mold plate into close contact with the electrode on the insulating substrate, Fixing the mold plate,
(5) Electrodeposition of each electrode as a cathode electrode through the conductive film in an electrolytic solution, whereby the chip-shaped through-holes of the mold plate are formed on the multiple electrodes on the insulating substrate. A step of filling a hole with the thermoelectric conversion material to form a chip of the thermoelectric conversion material on each electrode;
(6) a step of removing the mold plate, and (7) a step of dissolving and removing the resin insulating mask with an organic solvent,
Are sequentially performed on the insulating substrate to form a half body of the thermoelectric conversion module in which the electrodes and the chips on the insulating substrate are arranged on the P-type and N-type thermoelectric conversion materials. A P-type half with an electrode and a P-type thermoelectric conversion material chip arranged thereon, and an N-type half with an electrode and an N-type thermoelectric conversion material chip arranged on another insulating substrate are prepared. And
A thermoelectric conversion in which a P-type thermoelectric conversion material chip and an N-type thermoelectric conversion material chip constitute a pair by combining the P-type half and the N-type half with their chip arrangement surfaces facing each other. A method for producing a thermoelectric conversion module, comprising producing a thermoelectric conversion module in which a large number of elements are combined. In claim 1,
A method of manufacturing a thermoelectric conversion module, wherein after the step (2) and before the step (4), a portion other than the chip formation planned position on the electrode is covered with another insulating mask.

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