JP2001024241A - Manufacture of thermoelectric power generation element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To ensure an insulating property between adjacent elements even when a gap between a P-type element and an N-type element is very small by a method wherein an average gap between the N-type element and the P-type element which are adjacent to each other and in which longitudinal grooves are worked, the amount of surface irregularities in the N-type element in which the longitudinal groove is worked and the diameter of an insulating spacer which is mixed with an adhesive are set at specific requirements. SOLUTION: Longitudinal grooves are worked in a P-type element 16 and an N-type element 18 in such a way that the value of an amount A of surface irregularities and that of an amount B of surface irregularities are nearly identical. In addition, the diameter D of every insulating spacer 34 is set at three times the amount A of surface irregularities in a longitudinal-groove working face 12. One-third of the diameter D of every insulating spacer 34 is offset by the amount A of surface irregularities in the longitudinal-groove working face 14 of the P-type element 16, one - third of the diameter D of every insulating spacer 34 is offset by the amount B of surface irregularities in the longitudinal-groove working face 14 of the N-type element 18, one - third of the diameter D of every insulating spacer 34 is formed as a gap between the P-type element 16 and the N-type element 18, and the contact of the P-type element 16 with the N-type element 18 is prevented. In addition, a mean gap G is set at five times the amount A of surface irregularities.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a method for manufacturing a thermoelectric power generation element used for a power generation device utilizing the Seebeck effect, and in particular, to a thermoelectric power generation element formed of a small number of thermocouples.

[0002]

2. Description of the Related Art A conventional method for manufacturing a thermoelectric power generating element will be described in the order of steps. In the first step, a P-type thermoelectric element and an N-type thermoelectric element are cut out from respective materials. In the second step, a number of vertical grooves are formed at the same pitch in the P-type thermoelectric element and the N-type thermoelectric element. In the third step, the longitudinal grooves of the P-type element and the longitudinal grooves of the N-type element are fitted to each other, and the P-type element and the N-type element are adjacently juxtaposed such that the longitudinal groove processing surfaces face each other. In the fourth step, the gap between the P-type element and the N-type element is filled using the surface tension of the epoxy-based adhesive, heat-cured, and integrated. In the fifth step, a number of horizontal grooves orthogonal to the vertical grooves are processed. In the sixth step, the substantially horizontal grooves are filled with an epoxy-based adhesive and cured by heating. In the seventh step, unnecessary portions on the upper and lower sides are removed, and a large number of prism-shaped P-type elements and N-type elements are fixed in a sword-like shape with an epoxy-based adhesive. In an eighth step, adjacent P-type and N-type elements are connected, and all elements are connected in series. In the ninth step, extraction electrodes are provided at the start point and the end point of all the elements to complete the thermoelectric power generation element.

Further, in the fourth step, an example is shown in which an insulating spacer having an average particle size of 8 μm is added to an epoxy-based adhesive in an amount of 5% by weight in a gap between a P-type element and an N-type element.

[0004]

However, in a wristwatch, in particular, a wristwatch for women, which is preferred to be small in size, the thermoelectric power generation element is also required to be downsized. The short circuit occurs between adjacent elements.

In a conventional manufacturing method in which a P-type element and an N-type element are combined and then an epoxy-based adhesive is filled, there is a possibility that the P-type element and the N-type element may come into contact when they are combined. In such a case, there is a fear that even if an epoxy-based adhesive is filled, the elements cannot be reliably insulated from each other. Therefore, development of a method for manufacturing a high-density thermoelectric power generation element is desired.

An object of the present invention is to provide a method for manufacturing a high-density thermoelectric power generation element capable of securing insulation between adjacent elements even when a gap between a P-type element and an N-type element is very small.

[0007]

In order to achieve the above-mentioned object, a method of manufacturing a thermoelectric power generation element according to the first aspect of the present invention is the same as that of the first aspect except that a part of each element in the thickness direction is left. Forming a vertical grooved N-type element and a vertical grooved P-type element in which a plurality of vertical grooves are formed in parallel at a pitch; and interchanging the vertical grooved N-type element and the vertical grooved P-type element with each other. A step of fitting so that the surfaces on which the vertical grooves are formed are opposed to each other; and an adhesive in which an insulating spacer is mixed in a gap between the vertically grooved N-type element and the vertically grooved P-type element fitted to each other. Filling and fixing to form a PN integrated element, and a portion of the PN integrated element other than a portion where the vertical grooved N-type element and the vertical grooved P-type element are fitted to each other. Removing to form a fixed blade element In the manufacturing method, the average gap G between the vertically grooved N-type element and the vertically grooved P-type element adjacent to each other, the surface irregularity A of the vertically grooved N-type element, the insulating property mixed in the adhesive The diameter D of the spacer satisfies the following condition: G = 5 × A D = 3 × A.

According to a second aspect of the present invention, there is provided a method of manufacturing a thermoelectric power generating element, wherein a plurality of vertical grooves are formed in parallel at the same pitch except for a part in the thickness direction. A step of forming an element and a longitudinally grooved P-type element, and a step of filling an adhesive mixed with an insulating spacer in each longitudinal groove of the longitudinally grooved N-type element and the longitudinally grooved P-type element, The vertical grooved N-type element filled with the adhesive and the vertical grooved P-type element filled with the adhesive are fitted and fixed so that the surfaces on which the vertical grooves are formed face each other. Forming a PN integrated element, and removing a portion of the PN integrated element other than a portion where the longitudinally grooved N-type element and the longitudinally grooved P-type element are fitted to each other. Forming a shape element.

According to a third aspect of the present invention, there is provided a method of manufacturing a thermoelectric power generating element according to the second aspect, wherein the vertical grooved N-type element and the vertical grooved P-type adjacent to each other are adjacent to each other. Average gap G with element, vertical groove processing N
The surface element A of the mold element and the diameter D of the insulating spacer mixed into the adhesive satisfy the condition of G = 5 × A D = 3 × A.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS (First Embodiment) A method for manufacturing a thermoelectric power generation element according to the present embodiment includes a vertical grooved N-type element having a plurality of vertical grooves formed in parallel and a vertical grooved P-type element. After filling the vertical grooved N-type element and the vertical grooved P-type element with each other with the adhesive mixed with the insulating spacer in each of the vertical grooves of the element, the surfaces on which the vertical grooves are formed are opposed to each other. To form a PN integrated element. Further, an average gap G between the vertically grooved N-type element and the vertically grooved P-type element adjacent to each other, a surface irregularity A of the vertically grooved N-type element, and a diameter of an insulating spacer mixed in the adhesive D satisfies the conditions of G = 5 × A and D = 3 × A. Hereinafter, a method for manufacturing a thermoelectric power generation element according to the present embodiment will be described with reference to FIGS.
Description will be made in the order of steps.

The first step is a step of cutting out both a P-type thermoelectric element and an N-type thermoelectric element from respective materials. From each raw material of the P-type thermoelectric element and the N-type thermoelectric element, a rectangular parallelepiped P-type thermoelectric element blank and an N-type thermoelectric element blank are cut out.

In the second step, as shown in FIG. 1, a large number of vertical grooves 17, 19 are formed on both the P-type thermoelectric element blank and the N-type thermoelectric element blank at the same pitch. Thus, a longitudinally grooved N-type element 18 shown in FIG. 1A and a longitudinally grooved P-type element 16 shown in FIG. 1B are formed. The flute processing is performed by a wire saw or a micro grinder.

In the third step, as shown in FIG. 2, an insulating spacer 34 (not shown) is provided in each of the vertical grooves 17, 19 of the vertical grooved P-type element 16 and the vertical grooved N-type element 18. This is a step of pouring the mixed epoxy adhesive 36. FIG. 2A shows a vertical grooved N-type element 18, and FIG. 2B shows a vertical grooved P-type element 16.

In the fourth step, as shown in FIG. 3, the vertical groove 17 of the vertical grooved P-type element 16 and the vertical groove 19 of the vertical grooved N-type element 18 are fitted to each other. Vertical groove processing P
The excess epoxy adhesive 36 is pushed out and fitted so that the mold element 16 and the longitudinal grooved N-type element 18 are juxtaposed and juxtaposed. The overflowing epoxy-based adhesive 36 is wiped off and cured by heating. Thus, a PN integrated element 32 in which the longitudinally grooved P-type element 16 and the longitudinally grooved N-type element 18 are integrated is formed.

FIG. 4 shows a partially enlarged view of the longitudinal section of FIG. The insulating spacer 34 and the epoxy adhesive 36
Through the vertical grooved P-type element 16 and the vertical grooved N-type element 1
8 are fitted to form a PN integrated element 32.

FIG. 5 is a partially enlarged view of FIG. FIG. 5A shows the amount of surface irregularities A and B on the vertical grooved surfaces 12 and 14.
This shows a state in which the insulating spacer 34 prevents contact between the longitudinally grooved P-type element 16 and the longitudinally grooved N-type element 18. FIG. 5 (b) shows the vertical groove processing P-type element 16 and the vertical groove processing N
This shows a state where a smooth combination is possible without the mold element 18 and the insulating spacer 34 being engaged with each other.

As shown in FIG. 5, in this embodiment,
The surface irregularities A and B of the vertical grooved surfaces 12 and 14 of the vertical grooved P-type element 16 and the vertical grooved N-type element 18, the diameter D of the insulating spacer 34, and the adjacent P-type elements The relationship between the average gap G between the N-type element 16 and the N-type element 18 is set as follows.

In this embodiment, the surface unevenness amount A and
Vertical groove processing is performed on the P-type element 16 and the N-type element 18 so that the value of the surface unevenness amount B becomes substantially the same. In addition, the diameter D of the insulating spacer 34 is set to be three times the surface unevenness amount A of the vertical groove processing surface 12. In this case, as shown in FIG. 5A, one-third of the diameter D of the insulating spacer 34 is offset by the surface irregularity A of the vertical grooved surface 12 in the P-type element 16, and the insulating spacer 34 One-third of the diameter D is offset by the surface irregularity B of the vertical grooved surface 14 in the N-type element 18, and the remaining one-third of the diameter D of the insulating spacer 34.
Are formed as gaps between the P-type element 16 and the N-type element 18 to prevent contact between the P-type element 16 and the N-type element 18.

Further, as shown in FIG. 5B, the average gap G is set to be five times the surface irregularity amount A. Three-fifths of the average gap G are offset by the diameter D of the insulating spacer 34, and one-fifth of the average gap G is offset by the surface irregularities A or B of the P-type element or the N-type element. Is the average gap G
Is left, so that the vertical grooved P-type element 16, the vertical grooved N-type element 18, and the insulating spacer 34 do not mesh with each other, and a smooth combination is possible.

The fifth step is, as shown in FIG. 6, a step of forming a large number of horizontal grooves 34 orthogonal to the vertical grooves by using a wire saw or a micro grinder for the PN integrated element 32. Thereby, the lateral groove processing element 42 is completed.

The sixth step is, as shown in FIG. 7, a step of filling a lateral groove epoxy-based adhesive 44 into a large number of lateral grooves 46 of the lateral groove processing element 42 and heating and curing the same. Thereby, the lateral groove filling element 52 is completed. It is preferable that the epoxy adhesive 44 for a lateral groove contains a large amount of insulating beads having a diameter slightly smaller than that of the lateral groove 46 to reduce the amount of curing shrinkage of the epoxy adhesive 44 for a lateral groove.

As shown in FIG. 8, the seventh step is a step of removing unnecessary portions 54 and unnecessary portions 56 above and below the lateral groove filling element 52 by grinding, and comprises a large number of prismatic P-type elements 57.
Then, the N-type element 58 is fixed in the shape of a sword with an epoxy-based adhesive. Thereby, the epoxy fixed sword mountain-shaped element 6
2 is completed.

In an eighth step, as shown in FIG. 9, adjacent P-type elements 57 and N-type elements 58 on the front and back sides of the epoxy-fixed sword-shaped element 62 are alternately connected on the front and back sides, and all the elements are connected in series. This is the step of connecting to a book. As a specific method, a metal mask having a predetermined pattern formed on the surface of the epoxy-fixed sword mountain-shaped element 62 is set at a predetermined position, and then a conductive metal such as nickel, chromium, or copper is deposited.
4, 75, 76, 77, 78 are formed. This allows
The front and back connection element 72 is completed.

The ninth step is, as shown in FIG. 10, a step of providing extraction electrode portions 74 and 76 at the start point and the end point of all the front and back connection elements 72. Thus, a thermoelectric power generation element completed body 82 is obtained.

Next, the second to fourth steps of the method for manufacturing a thermoelectric timepiece according to the present embodiment will be described using specific numerical values. Other steps are common to each embodiment.

(Example 1) In the second step of forming grooves in the rectangular parallelepiped P-type thermoelectric element blank and the N-type thermoelectric element blank cut out in the first step, ordinary abrasive grains are used and a wire saw is used. , At a normal cutting speed. Thereby, the value of the surface unevenness amount A of the vertical groove processed surface shown in FIG.
About.

In the third step, since the unevenness amount A of the processed surface of the vertical groove is about 3 μm, the epoxy adhesive 36 containing 5% by weight of the insulating spacer 34 having a diameter D of φ9 μm is used.
Is poured into the vertical grooves 17 and 19 shown in FIG.

In the fourth step, as shown in FIG. 4, the vertical groove 17 of the vertical grooved P-type element 16 and the vertical groove 19 of the vertical grooved N-type element 18 are combined with each other. 3 μm out of the diameter φ of 9 μm of the insulating spacer 34 mixed with the system adhesive 36 is the vertical grooved P-type element 16.
Is offset by the surface irregularity amount A of the processed surface. Further vertical groove processing N
3 μm is offset by the surface irregularities A of the processing surface of the mold element 18. However, since 3 μm remains, the adjacent vertical groove processing P
There is no contact between the mold element 16 and the vertical grooved N-type element 18s.

Next, the reason why the average gap G is five times the surface irregularity A will be described using numerical values. The value of the average gap G between adjacent elements is 15 μm, which is five times the surface irregularity amount A = 3 μm. Three-fifths of the average gap G between adjacent elements is 15 μm,
It is offset by φ9 μm of the insulating spacer 34 and is reduced to one fifth.
Are offset by a surface irregularity of 3 μm. However, since 3 μm, which is one fifth of the average gap between adjacent elements, remains, the vertical grooved P-type element 16, the vertical grooved N-type element 18, and the insulating spacer 34 do not engage with each other, and a smooth combination is achieved. It is possible.

(Embodiment 2) In Embodiment 2, in the second step, finer than usual abrasive grains are used, and a wire saw is used for processing at a lower cutting speed than usual. Thereby, the value of the surface unevenness amount A of the vertical groove processing surface becomes about 2 μm.

In the third step, the unevenness amount A of the processed surface is 2 μm.
m, the epoxy adhesive 36 containing 4% by weight of the insulating spacer 34 having a diameter of 6 μm is poured.

The fourth step is the same as that of the first embodiment, and the vertical grooved P-type element 16 and the vertical grooved N-type element 18 do not come into contact with each other. In Example 2, the average gap between adjacent elements is set to 10 μm since the amount of unevenness on the processed surface is about 2 μm.

(Embodiment 3) In a third embodiment, in the second step, a grindstone in which fine diamond abrasive grains are embedded is used.
Process with a micro grinder. Thereby, the value of the surface unevenness amount A of the vertical groove processing surface becomes about 1 μm.

In the third step, since the value of the unevenness amount A of the processed surface is about 1 μm, the epoxy adhesive 36 containing 3% by weight of the insulating spacer 34 of φ3 μm is poured.

The fourth step is the same as that of the first embodiment, and the vertical grooved P-type element 16 and the vertical grooved N-type element 18 do not come into contact with each other. Further, in Example 3, the unevenness amount A of the processed surface
Is about 1 μm, the average gap between adjacent elements is 5 μm.
And

As described above, according to the method of manufacturing the thermoelectric power generating element of the present embodiment, the longitudinal grooved N-type element and the longitudinal grooved P-type element are formed under the predetermined production conditions set in this embodiment.
After filling an adhesive mixed with an insulating spacer in each of the vertical grooves of the die element, the vertical grooved N-type element and the vertical grooved P-type element are opposed to each other by the surfaces on which the vertical grooves are formed. Thus, even if the gap between the adjacent elements is very small, the insulation between the adjacent elements can be ensured, and a high-density thermoelectric power generation element can be obtained.

(Second Embodiment) A method of manufacturing a thermoelectric power generation element according to the present embodiment is a method of manufacturing a vertical grooved N-type element having a plurality of vertical grooves formed in parallel with a vertical grooved P-type element. An adhesive in which an insulating spacer is mixed in a gap between the vertically grooved N-type element and the vertically grooved P-type element which are fitted to each other so that the surfaces on which the vertical grooves are formed face each other. And fixed to form a PN integrated element,
The flute N-type element and the flute P which are adjacent to each other
Average gap G with the mold element, amount of surface irregularity A of the vertical grooved N-type element, diameter D of the insulating spacer mixed into the adhesive
Satisfy the conditions of G = 5 × A and D = 3 × A. Hereinafter, a method for manufacturing the thermoelectric power generation element according to the present embodiment will be described with reference to FIGS.

The first step and the second step in the second embodiment are the same as those in the first embodiment, and a description thereof will be omitted.

In the third step, as shown in FIG. 11, the vertical groove 27 of the vertical grooved P-type element 26 and the vertical groove 29 of the vertical grooved N-type element 28 are fitted to each other. Vertical groove processing P
The mold element 26 and the longitudinal grooved N-type element 28 are fitted so as to be adjacently juxtaposed.

In the fourth step, as shown in FIG.
The gap between the vertically grooved N-type element 28 and the vertically grooved P-type element 26 fitted to each other is filled with an epoxy adhesive 36 mixed with an insulating spacer 34 by utilizing its surface tension and fixed. Then, the PN integrated element 20 is formed. At this time, as shown in FIG. 12B, the average gap G between the vertically grooved N-type element 28 and the vertically grooved P-type element 26 adjacent to each other, the surface irregularity of the vertically grooved N-type element 28, Quantity A,
The surface unevenness amount B of the vertical grooved P-type element 26 and the diameter D of the insulating spacer 34 mixed in the adhesive are G = 5 ×
The processing conditions of each process are set so as to satisfy the conditions of A, D = 3 × A, B ≒ A.
Since it is the same as that of the first embodiment, the description is omitted here.

The fifth to ninth steps are the same as those in the first embodiment, and therefore will not be described.

As described above, according to the method for manufacturing a thermoelectric power generation element of the present embodiment, when the gap between adjacent elements is very small, even if it is the same as the conventional process,
Under the predetermined manufacturing conditions set in the present embodiment, the thermoelectric power generation element is manufactured, so that even when the gap between the adjacent elements is small, insulation can be secured and a high density thermoelectric power generation element is obtained. I was able to do it.

[0043]

As described above, according to the method for manufacturing a thermoelectric power generation element of the present invention, the manufacturing including the relationship among the surface unevenness of the vertical grooved surface of the element, the gap between adjacent elements, and the diameter of the insulating spacer. Since the conditions are set optimally,
High insulation can be ensured even when the gap between the P-type element and the N-type element is very small. Therefore, it is possible to realize a small and high-density thermoelectric generator. As a result, it is possible to provide a small wristwatch incorporating a thermoelectric power generation element.

[Brief description of the drawings]

FIG. 1 shows a P-type element and N according to a first embodiment of the present invention.
The figure which shows the vertical groove processing process of a type | mold element.

FIG. 2 shows a P-type element and N according to the first embodiment of the present invention.
The figure which shows the process of filling an epoxy adhesive in the vertical groove of a type | mold element.

FIG. 3 shows a P-type element and N according to the first embodiment of the present invention.
The figure which shows the process of fitting and integrating a mold element.

FIG. 4 is a partially enlarged longitudinal sectional view of FIG. 3 according to the first embodiment of the present invention.

FIG. 5 is a partially enlarged view of FIG. 4 according to the first embodiment of the present invention.

FIG. 6 is a view showing a lateral groove processing step of the thermoelectric power generation element according to the first embodiment of the present invention.

FIG. 7 is a view showing a step of filling an epoxy-based adhesive in a lateral groove of the thermoelectric generator according to the first embodiment of the present invention.

FIG. 8 is a view showing a step of removing unnecessary portions above and below the thermoelectric generator according to the first embodiment of the present invention.

FIG. 9 is a view showing a step of connecting all elements in series according to the first embodiment of the present invention.

FIG. 10 is a diagram showing a completed thermoelectric generator according to the first embodiment of the present invention.

FIG. 11 is a view showing a step of fitting a P-type element and an N-type element according to the second embodiment of the present invention.

FIG. 12 is a view showing a step of filling an epoxy-based adhesive into a gap between a fitted P-type element and an N-type element according to the second embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 12 vertical groove processing surface of P-type element 14 vertical groove processing surface of N-type element 16 vertical groove processing P-type element 17 vertical groove 18 vertical groove processing N-type element 19 vertical groove 32 PN integrated element 34 Insulating spacer 36 Epoxy adhesive 42 Horizontal groove processing element 44 Epoxy adhesive for horizontal groove 46 Horizontal groove 52 Horizontal groove filling element 62 Epoxy fixed sword-shaped element 72 Front / back connection element 82 Thermoelectric generator completed

Claims (3)

[Claims] A step of forming a vertical grooved N-type element and a vertical grooved P-type element in which a plurality of vertical grooves are formed in parallel at the same pitch except for a part of each in the thickness direction; A step of fitting the longitudinal grooved N-type element and the longitudinal grooved P-type element so that the surfaces on which the longitudinal grooves are formed are opposed to each other; Groove processing P
Forming a PN integrated element by filling and fixing an adhesive mixed with an insulating spacer into a gap between the PN element and the mold element;
Removing a portion of the integrated element other than the part where the flute N-type element and the flute P-type element are fitted to each other to form a fixed sword-shaped element. In the manufacturing method, the vertical grooved N-type element and the vertical grooved P which are adjacent to each other are formed.
Average gap G with the mold element, amount of surface irregularity A of the vertical grooved N-type element, diameter D of the insulating spacer mixed into the adhesive
Satisfies the following condition: G = 5 × A D = 3 × A. 2. A step of forming a longitudinally grooved N-type element and a longitudinally grooved P-type element in which a plurality of vertical grooves are formed in parallel at the same pitch while leaving a part in each thickness direction; Filling an adhesive containing an insulating spacer into each of the vertical grooves of the vertical grooved N-type element and the vertical grooved P-type element, and the vertical grooved N-type element filled with the adhesive; Forming a PN integrated element by fitting and fixing the vertical grooved P-type element filled with the adhesive so that the surfaces on which the vertical grooves are formed oppose each other; Removing a part of the element other than the part where the flute N-type element and the flute P-type element are fitted to each other to form a fixed sword-shaped element. A method for manufacturing a power generating element. 3. An average gap G between the longitudinally grooved N-type element and the longitudinally grooved P-type element adjacent to each other;
3. The thermoelectric generator according to claim 2, wherein the surface irregularity amount A of the mold element and the diameter D of the insulating spacer mixed into the adhesive satisfy the following condition: G = 5 × A D = 3 × A. Production method.