JP2000058930A - Thermoelement, and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obviate the necessity of providing a metallic member for heat radiation or heat absorption used in combination with a thermoelement individually with heat well conductive electric insulating films, in a both-side skeleton structure or one-side skeleton structure of thermoelement. SOLUTION: A thermoelement is composed of a p-type thermoelectric semiconductor element 2P and an n-type thermoelectric semiconductor element 2N, an upper electrode 4 joined with the topside of the p-type thermoelectric semiconductor element 2P and the n-type thermoelectric semiconductor element 2N, a lower electrode 3 joined with the bottom of the p-type thermoelectric semiconductor element 2N and the n-type thermoelectric semiconductor element 2N, an upper heat well conductive electric insulating film 6 joined with the upper electrode 4, and a lower heat well conductive electric insulating film 6 joined with the lower electrode 3. When using this thermoelement, a metallic member for heat radiation or heat absorption is attached through the heat well conductive electric insulating films 5 and 6. Accordingly, there is no necessity to form heat well conductive electric insulating films individually in the metallic member for heat radiation or heat absorption.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoelectric element using a thermoelectric semiconductor element such as a Peltier element and a method of manufacturing the same, and more particularly, to a thermoelectric element having a skeleton structure and a method of manufacturing the same.

[0002]

2. Description of the Related Art Thermoelectric elements using thermoelectric semiconductor elements made of bismuth / tellurium compounds, iron / silicide compounds or cobalt / antimony compounds are used in cooling / heating devices and the like. These thermoelectric elements are useful as cooling / heating sources that do not use liquids or gases, take up little space, have no rotational wear, and do not require maintenance.

FIG. 10 shows the configuration of a conventionally known thermoelectric module. (A) of this figure is a front view,
(B) is a perspective view. As shown in this figure, in the thermoelectric module, n-type thermoelectric semiconductor elements and p-type thermoelectric semiconductor elements are alternately arranged, and the upper and lower surfaces of the n-type thermoelectric semiconductor element and the p-type thermoelectric semiconductor element are joined to metal electrodes. Have been. The n-type thermoelectric semiconductor element and the p-type thermoelectric semiconductor element are alternately joined to the metal electrodes on the upper surface and the lower surface, and finally all the thermoelectric semiconductor elements are electrically connected in series. The joining between the upper and lower metal electrodes and the thermoelectric semiconductor element is performed by soldering. Each of the upper and lower metal electrodes is joined on a metallized ceramic substrate and fixed as a whole.

When a DC power supply is connected to the electrodes of the thermoelectric module and a current flows from the n-type element to the p-type element,
Due to the Peltier effect, heat is absorbed at the upper part of the π type and heat is released at the lower part. At this time, when the direction of the current is reversed, the directions of heat absorption and heat radiation change. Utilizing this phenomenon, thermoelectric elements are used in cooling / heating devices. Thermoelectric modules have a wide range of uses, from cooling LSIs, computer CPUs, lasers, etc. to insulated refrigerators.

When such a thermoelectric element is used as a cooling device, it is necessary to efficiently release heat on the heat radiation side. Conventionally, as a method of releasing heat on the heat radiation side of the thermoelectric element, a heat radiation fin is attached to the heat radiation side of the thermoelectric element, and an air cooling system in which a fan sends air toward the heat radiation fin, or a method of thermoelectric element. There has been a water cooling system or the like in which a water cooling jacket is attached to the heat radiation side and cooling water is passed through the water cooling jacket.

However, all of these cooling systems are indirectly cooling the thermoelectric semiconductor element via the substrate on the heat radiation side, and thus do not efficiently discharge the heat on the heat radiation side. Further, since the thermoelectric element shown in FIG. 10 has a rigid structure in which the upper and lower parts are fixed by a ceramic substrate, a large thermal stress is applied to the thermoelectric semiconductor element during operation, and the life of the thermoelectric semiconductor element is shortened. Was.

Accordingly, the applicant of the present application has previously filed Japanese Patent Application No. Hei 8-3
No. 54136 proposes a thermoelectric element having a structure in which upper and lower metal electrodes are exposed without being fixed to a substrate (double-sided skeleton structure).

FIG. 11 is a front view of the thermoelectric element. This thermoelectric element is a p-type thermoelectric semiconductor element 2
It has a structure in which P and the n-type thermoelectric semiconductor element 2N are fixed in a state where they penetrate. The partition plate 1 has, for example, a thickness of 0.3 to
It is made of an electrically insulating plate of about 0.6 mm, for example, a glass epoxy plate. The p-type and n-type thermoelectric semiconductor elements 2P and 2N are made of a semiconductor single crystal such as bismuth tellurium having a length of about 1.5 to 2 mm, for example. The partition plate 1 is fixed in a penetrating state so that a length of about 0.5 to 0.8 mm protrudes below the partition plate 1.

A plate-like upper electrode 4 is provided on the upper side of the p-type thermoelectric semiconductor element 2P and the n-type thermoelectric semiconductor element 2N, and a lower electrode 3 having a substantially T-shaped side surface is provided on the lower side. It is joined by.

When the thermoelectric element is used, the thermoelectric cooling device is configured such that the portion below the partition plate 1 comes into direct contact with the coolant or the like. This thermoelectric cooling device is also proposed in the aforementioned Japanese Patent Application No. 8-354136.

According to this thermoelectric element, since the upper and lower metal electrodes are not fixed to the rigid substrate, the thermal stress applied to the thermoelectric semiconductor element is reduced. As a result, a longer life of the thermoelectric semiconductor element is realized. Further, according to this thermoelectric cooling device, since the thermoelectric semiconductor element and the metal electrode on the heat radiation side are directly cooled, the heat on the heat radiation side can be efficiently released.

[0012]

In the above-described thermoelectric element having a skeleton structure on both sides, since the upper and lower metal electrodes are exposed, a heat-radiating or heat-absorbing metal member (such as a heat sink) used in combination with the thermoelectric element is used. It was necessary to provide a thermally conductive electrically insulating thin film. And since there are various shapes of these metal members,
It was troublesome to separately provide the thermally conductive electric insulating thin film there.

When manufacturing a thermoelectric element having a double-sided skeleton structure, it is necessary to arrange a number of metal electrodes in a predetermined pattern, align the thermoelectric semiconductor element with the pattern, and perform soldering. Met.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and in a thermoelectric element having a double-sided skeleton structure or a single-sided skeleton structure, a heat-radiating or heat-absorbing metal member used in combination with the thermoelectric element is preferably used. An object of the present invention is to make it unnecessary to separately provide a conductive electrically insulating thin film.

Further, the present invention eliminates the need for arranging a large number of metal electrodes in a predetermined pattern when manufacturing a thermoelectric element having a double-sided skeleton structure or a single-sided skeleton structure,
The objective is to simplify the manufacturing process and reduce the manufacturing cost.

[0016]

A thermoelectric element according to the present invention comprises a p-type thermoelectric semiconductor element and an n-type thermoelectric semiconductor element;
A first metal electrode joined to first surfaces of the p-type thermoelectric semiconductor element and the n-type thermoelectric semiconductor element; and a first metal electrode joined to second surfaces of the p-type thermoelectric semiconductor element and the n-type thermoelectric semiconductor element A second metal electrode, and a thermally conductive electrically insulating thin film joined to at least one of the first metal electrode and the second metal electrode.

In the thermoelectric element according to the present invention, the p-type thermoelectric semiconductor element and the n-type thermoelectric semiconductor element may have a structure in which the p-type thermoelectric semiconductor element penetrates the electrically insulating partition plate and is fixed to the partition plate. Good or not.

Further, in the thermoelectric element according to the present invention,
The thermally conductive electrically insulating thin film may be integrally formed as a single film, or these metal electrodes may correspond to individual first metal electrodes or individual second metal electrodes. They may be configured separately so as to have the same number.

The method for manufacturing a thermoelectric element according to the present invention comprises:
Forming the first metal electrode pattern and the second metal electrode pattern by etching the metal plate and the second metal plate, and forming the first metal electrode pattern and the second metal electrode pattern by p. Type thermoelectric semiconductor element and n
And a bonding step of bonding to the first surface and the second surface of the thermoelectric semiconductor element.

In the method of manufacturing a thermoelectric element according to the present invention, the heat-resistant resin sheet and the first
At least one of the metal plate and the second metal plate may be bonded, and the heat-resistant resin sheet may be peeled off after the bonding step.

In the thermoelectric element according to the present invention, a thermoelectrically conductive thin insulating film is bonded to at least one of the first metal electrode pattern and the second metal electrode pattern. , A metal member for heat dissipation or heat absorption is attached through the thermally conductive electrically insulating thin film. Therefore, it is not necessary to separately form a thermally conductive and electrically insulating thin film on the metal member for heat dissipation or heat absorption.

In the method for manufacturing a thermoelectric element according to the present invention, a plurality of metal electrodes arranged in a predetermined pattern are completed by etching a metal plate. When the step of bonding and peeling the heat-resistant resin sheet is performed, the metal electrode pattern is fixed to the heat-resistant resin sheet during the electrode forming step and the joining step, so that these steps can be easily performed. Can be. Also, if a thermally conductive electric insulating thin film is formed on the surface of the metal plate, the metal electrode pattern is fixed to the heat-resistant resin sheet via the thermally conductive electric insulating thin film. More accurate positioning is possible.

[0023]

Embodiments of the present invention will be described below in detail with reference to the drawings.

FIG. 1 is a front view of a thermoelectric element according to the present invention. In this figure, the same parts as in FIG.
Are assigned the same reference numerals as those used in FIG.

As shown in this figure, the thermoelectric element according to the present invention has a structure in which the p-type thermoelectric semiconductor element 2P and the n-type thermoelectric semiconductor element 2N are fixed to the partition plate 1 in a state where they penetrate. The upper electrode 4 made of a copper plate is joined to the upper surface of the p-type thermoelectric semiconductor element 2P and the n-type thermoelectric semiconductor element 2N, and the lower electrode 3 made of a copper plate is joined to the lower surface by soldering. Although not shown, Ni (nickel) is formed on the surfaces of the upper electrode 4 and the lower electrode 3.
Plated. This Ni plating layer functions as a diffusion prevention layer for preventing copper molecules constituting the electrode from diffusing into the thermoelectric semiconductor element.

Furthermore, under surface and the upper surface of the upper electrode 4 of the lower electrode 3, respectively several tens to several hundreds μm thickness, preferably lower thermal good conductivity electrically insulating thin film 5 of about 15~100μm
And the upper thermal conductive electrical insulating thin film 6 is joined.
As a material for these thermally conductive electrically insulating thin films, for example, a material obtained by adding a thermally conductive filler to an epoxy resin, a fluorine resin coat, a silicon-based thermally conductive adhesive, or the like can be used.

When a metal heat sink is attached to the thermoelectric element configured as described above, unlike the thermoelectric element shown in FIG. 11, there is no need to provide electrical insulation between the electrode and the heat sink.

Next, a method of manufacturing the thermoelectric element shown in FIG. 1 will be described.

FIG. 2 shows a process for manufacturing a member to be the lower electrode 3 and the lower thermal conductive insulating layer 5. In this figure, parts corresponding to those in FIG. 1 are denoted by the same reference numerals as those used in FIG.

FIG. 3A shows a member in which a lower thermal conductive insulating thin film 5 is formed on the lower surface of a lower electrode material 3 made of a copper plate. (B) shows a lower adhesive layer 11 on the upper surface of a lower substrate 12 made of a heat-resistant resin sheet, for example, a sheet of polyimide or PET having a thickness of about 50 μm.
Is applied. Here, the lower adhesive layer 11
The adhesive used for the above is preferably an adhesive (foamable adhesive) having a property that the adhesive strength is greatly reduced when heated, but does not peel off in the etching and Ni plating steps described later. Alternatively, other adhesives may be used as long as the adhesive strength is adjusted so as to be easily peeled off in the final step after the electrode bonding. The lower base material 12 has a function of supporting the lower electrode 3 at the time of etching, which will be described later, a role of facilitating positioning during subsequent positioning, a role of facilitating handling, and the like. Further, the lower electrode 3 and the lower adhesive adhesive layer 11
By interposing the lower heat conductive insulating layer 5 between the lower electrode 3 and the lower electrode 3, the lower electrode 3 can be positioned more easily than when the lower electrode 3 is directly bonded to the lower adhesive adhesive layer 11. It can be performed precisely.

First, as shown in FIG. 2 (c), the upper surface of the lower substrate 12 and the lower thermal conductive insulating layer 5 are adhered by the lower adhesive adhesive layer 11. Next, as shown in FIG. 2C, the lower electrode material 3 is etched to form a plurality of lower electrodes 3 at the same time. Next, the surface of the lower electrode 3 is plated with Ni. Through the above steps, a member to be the lower electrode 3 and the lower thermal conductive insulating layer 5 is completed.

After the electrode unit is formed, positioning holes 12A to 12D (details will be described later) are formed in the lower adhesive layer 11 and the lower substrate 12. By the same process, members that become the plurality of upper electrodes 4 and the upper thermal conductive insulating layer 6 can be manufactured.

FIG. 3 is a diagram showing members and jigs used for manufacturing a thermoelectric element. In this figure, parts corresponding to those in FIG. 2 are denoted by the same reference numerals as those used in FIG.

FIG. 3A shows the upper soldering jig 15. The upper soldering jig 15 is formed in a plate shape, and has positioning holes 15A to 15H on its lower surface into which positioning pins 16A to 16H to be described later are inserted. In addition, these positioning holes 15A to 15H may penetrate up and down the jig.

FIG. 3B shows a member to be the upper electrode 4 and the upper thermal conductive insulating layer 6. As described above, this member is manufactured in the same manner as the process shown in FIG. FIG. 3C shows a member in which the p-type thermoelectric semiconductor element 2P and the n-type thermoelectric semiconductor element 2N penetrate the partition plate 1 and are fixed. The method of manufacturing this member is described in detail in JP-A-8-228027,
It is not described here.

FIG. 3D shows a member to be the lower electrode 3 and the lower thermal conductive insulating layer 5. This member is manufactured by the process shown in FIG. Although description is omitted in FIG. 2, holes 12A to 12D into which positioning pins 16A to 16D are inserted are formed in the lower substrate 12 and the lower adhesive layer 11 shown in FIG. 2B. Have been. Similarly, holes 13 </ b> A to 13 </ b> A into which positioning pins 16 </ b> A to 16 </ b> D are inserted are formed in upper substrate 13 and upper adhesive layer 14.
D is open.

FIG. 3E shows the lower soldering jig 16. The lower soldering jig 16 is formed in a plate shape, and positioning pins 16A to 16H protrude from the upper surface.

Next, a process of manufacturing the thermoelectric element shown in FIG. 1 using the members and jigs shown in FIGS. 3A to 3E will be described. Here, before this step, the upper surface of the lower electrode 3 in the member shown in FIG.
The cream solder is printed on the lower surface of the upper electrode 4 in the member shown in FIG.

First, the positioning pins 16A to 16D on the lower soldering jig 16 shown in FIG.
Through the holes 12A to 12D of the member shown in FIG. FIG. 4 is a plan view in this state. In FIG. 4, the positioning pin 16A is used.
The diameters of the positioning holes 12A to 12D are shown large so that the relationship between the positioning holes 12A to 12D and the positioning holes 12A to 12D can be easily understood. The lower electrode 3 is omitted.

Next, the members shown in FIG.
Place on the member shown in (d). At this time, the partition plate 1
Since the vertical and horizontal sizes are equal to the vertical and horizontal sizes of the lower thermal conductive electrically insulating thin film 5, the portions near the four corners of the partition plate 1 contact the positioning pins 16A to 16H, and Is fixed.

Next, the member shown in FIG. 3B is placed on the member shown in FIG. At this time, positioning is performed so that the positioning pins 16A to 16D pass through the positioning holes 13A to 13D.

Next, on the member shown in FIG.
The upper soldering jig 15 shown in FIG. At this time, the positioning pins 16A to 16H are aligned with the positioning holes 15A.
Position it so that it fits into １５15H.

By the above operation, the state shown in FIG. 5 is obtained. In this state, the p-type thermoelectric semiconductor element 2P is soldered by placing it in a solder reflow furnace or soldering it, or by incorporating a heater in the upper soldering jig 15 and the lower soldering jig 16 and heating the heater. And n
The upper electrode 3 and the lower electrode 4 are joined to the type thermoelectric semiconductor element 2N.

When the joining of the upper electrode 3 and the lower electrode 4 is completed, as shown in FIG. 6, the integrally joined members are connected to the upper soldering jig 15 and the lower soldering jig 16.
The thermoelectric element shown in FIG. 1 is completed by separating the upper substrate 13 and the lower substrate 12 from each other. At this time, the adhesive force between the upper adhesive layer 14 and the lower adhesive layer 11 decreases due to the heat at the time of soldering,
Since there is almost no adhesive force, it can be easily peeled off.

The present invention is not limited to the above-described embodiment, and for example, the following modifications (1) to (6) are possible.

(1) If the lower electrode material 3 on which the lower thermally conductive electrically insulating thin film 5 is not used is used instead of the member shown in FIG. Can be manufactured. Needless to say, in this case, it is necessary to form a thermally conductive electrically insulating thin film on a heat sink or the like when using the thermoelectric element. However, when manufacturing the thermoelectric element, the electrodes are formed one by one in a predetermined pattern as in the conventional case. Since there is no need to arrange, the manufacturing process is simplified.

(2) A thermoelectric element without a partition plate as shown in FIG. 7 may be used. When manufacturing this thermoelectric element, one p-type thermoelectric semiconductor element and one n-type thermoelectric semiconductor element are used.
A step of arranging one by one is required.

(3) In FIGS. 1 and 7, the lower thermal conductive electrical insulating thin film 5 and the upper thermal conductive electrical insulating thin film 6
Each of them is integrally formed and has a portion that is not in contact with the lower electrode 3 and the upper electrode 4. As shown in FIGS. 8 and 9, the lower heat conductive electrically insulating thin film 5 and the upper heat The good electrical insulating thin film 6 may be formed as a separate thin film corresponding to each of the lower electrode 3 and the upper electrode 4.

(4) P-type thermoelectric semiconductor element 2 in FIG.
P, n-type thermoelectric semiconductor element 2N, lower electrode 3, upper electrode 4, lower thermal conductive electrical insulating thin film 5, and upper thermal conductive electrical insulating thin film 6 (in particular, the electrode and the thermoelectric semiconductor element) (In the vicinity of the junction with the resin) may be coated with a silicone resin to impart water repellency, thereby improving the moisture resistance. The same applies to FIG. 1, FIG. 7, and FIG.

(5) The present invention can be applied to the manufacture of a thermoelectric element having a one-sided skeleton structure.

(6) The thermoelectric element may be manufactured without using the upper substrate 12 and the lower substrate 13.

[0052]

As described in detail above, according to the thermoelectric element according to the present invention, the thermoconductive element is joined to the upper and lower metal electrodes. In this case, it is not necessary to separately form a thermally conductive and electrically insulating thin film on the metal member for heat dissipation or heat absorption. For this reason, it becomes easy to use in combination with heat sinks of various shapes.

Further, according to the method of manufacturing a thermoelectric element according to the present invention, the step of arranging a large number of electrodes in a predetermined pattern is not required, so that the manufacturing process is simplified, and as a result, the cost is reduced.

[Brief description of the drawings]

FIG. 1 is a front view of a thermoelectric element according to the present invention.

FIG. 2 is a view illustrating a process of manufacturing a member to be a lower electrode and a lower thermal conductive insulating thin film of FIG. 1;

FIG. 3 is a diagram showing members and jigs used for manufacturing a thermoelectric element according to the present invention.

FIG. 4 is a diagram illustrating positioning in a method for manufacturing a thermoelectric element according to the present invention.

FIG. 5 is a view showing a state at the time of soldering in the method for manufacturing a thermoelectric element according to the present invention.

FIG. 6 is a view showing a step of peeling a substrate in the method for manufacturing a thermoelectric element according to the present invention.

FIG. 7 is a front view of the thermoelectric element without the partition plate of FIG. 1;

8 is a front view of a thermoelectric element in which the thermally conductive insulating thin film of FIG. 1 is separately provided for each electrode.

9 is a front view of a thermoelectric element in which the thermally conductive insulating thin film of FIG. 7 is separately provided for each electrode.

FIG. 10 is a diagram showing a configuration of a conventional general thermoelectric module.

FIG. 11 is a view showing a thermoelectric element of a skeleton type on both sides.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Partition plate 2P p-type thermoelectric semiconductor element 2N n-type thermoelectric semiconductor element 3 Lower electrode 4 Upper electrode 5 Lower thermal conductive electrical insulating thin film 6 Upper thermal conductive electrical insulating thin film 11 Lower adhesive adhesive 12 Lower side Base material 13 Upper base material 14 Upper adhesive bonding 15 Upper soldering jig 16 Lower soldering jig 16A to 16H Positioning pins

Claims (11)

[Claims] A p-type thermoelectric semiconductor element and an n-type thermoelectric semiconductor element; a first metal electrode joined to first surfaces of the p-type thermoelectric semiconductor element and the n-type thermoelectric semiconductor element; A second metal electrode bonded to a second surface of the thermoelectric semiconductor element and the n-type thermoelectric semiconductor element; and a good thermal conductivity bonded to at least one of the first metal electrode or the second metal electrode A thermoelectric element comprising an electrically insulating thin film. 2. A partition plate having electrical insulation properties, wherein the p-type thermoelectric semiconductor element and the n-type thermoelectric semiconductor element are fixed to the partition plate in a state of penetrating the partition plate. The thermoelectric element according to claim 1. 3. The method according to claim 1, wherein the first metal electrode or the second metal electrode has a plate shape.
6. The thermoelectric element according to claim 1. 4. Diffusion prevention for preventing molecules of the metal electrode from diffusing into the p-type thermoelectric semiconductor element and the n-type thermoelectric semiconductor element on the surfaces of the first metal electrode and the second metal electrode. The thermoelectric element according to any one of claims 1 to 3, wherein the layer is covered. 5. The thermally conductive electrically insulating thin film is a single integrally formed film.
The thermoelectric element according to any one of the above. 6. The thermally conductive electrically insulating thin film is composed of the same number of films as the number of metal electrodes separately formed corresponding to individual first metal electrodes or individual second metal electrodes. The thermoelectric element according to claim 1, wherein the thermoelectric element is provided. 7. An electrode forming step of etching a first metal plate and a second metal plate to form a first metal electrode pattern and a second metal electrode pattern; and forming the first metal electrode pattern and the second metal electrode pattern. A bonding step of bonding the second metal electrode pattern to the first surface and the second surface of the p-type thermoelectric semiconductor element and the n-type thermoelectric semiconductor element. 8. The method according to claim 1, further comprising, before the electrode forming step, a bonding step of bonding the heat-resistant resin sheet to at least one of the first metal plate and the second metal plate, and after the bonding step, The method for manufacturing a thermoelectric element according to claim 7, further comprising a peeling step of peeling the heat-resistant resin sheet. 9. The method according to claim 7, wherein at least one of the first metal plate and the second metal plate has a heat conductive and electrically insulating thin film formed on a surface thereof. Manufacturing method of thermoelectric element. 10. The p-type thermoelectric semiconductor element and the n-type thermoelectric semiconductor element
The method for manufacturing a thermoelectric element according to claim 7, wherein the thermoelectric semiconductor element is fixed to the partition plate while penetrating the partition plate having electrical insulation. 11. A method of coating a surface of the metal electrode with a diffusion preventing layer for preventing molecules of the metal electrode from diffusing into the p-type thermoelectric semiconductor element and the n-type thermoelectric semiconductor element. The method for manufacturing a thermoelectric element according to claim 7.