JP3482094B2 - Thermal stress relaxation pad for thermoelectric conversion element and thermoelectric conversion element - Google Patents
Thermal stress relaxation pad for thermoelectric conversion element and thermoelectric conversion elementInfo
- Publication number
- JP3482094B2 JP3482094B2 JP02942497A JP2942497A JP3482094B2 JP 3482094 B2 JP3482094 B2 JP 3482094B2 JP 02942497 A JP02942497 A JP 02942497A JP 2942497 A JP2942497 A JP 2942497A JP 3482094 B2 JP3482094 B2 JP 3482094B2
- Authority
- JP
- Japan
- Prior art keywords
- stress relaxation
- thermal stress
- conversion element
- thermoelectric conversion
- thermoelectric
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 230000008646 thermal stress Effects 0.000 title claims description 89
- 238000006243 chemical reaction Methods 0.000 title claims description 36
- 239000000463 material Substances 0.000 claims description 103
- 239000004020 conductor Substances 0.000 claims description 35
- 239000011810 insulating material Substances 0.000 claims description 25
- 229910052751 metal Inorganic materials 0.000 claims description 24
- 239000002184 metal Substances 0.000 claims description 24
- 239000000203 mixture Substances 0.000 claims description 23
- 238000005304 joining Methods 0.000 claims description 9
- 238000010292 electrical insulation Methods 0.000 claims description 3
- 239000010949 copper Substances 0.000 description 29
- 239000000919 ceramic Substances 0.000 description 22
- 238000001816 cooling Methods 0.000 description 21
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 20
- 229910052802 copper Inorganic materials 0.000 description 20
- 238000010438 heat treatment Methods 0.000 description 20
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 15
- 238000004519 manufacturing process Methods 0.000 description 10
- 238000000034 method Methods 0.000 description 10
- 239000004065 semiconductor Substances 0.000 description 10
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 description 9
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 229910002804 graphite Inorganic materials 0.000 description 6
- 239000010439 graphite Substances 0.000 description 6
- 238000004663 powder metallurgy Methods 0.000 description 6
- 229910052714 tellurium Inorganic materials 0.000 description 6
- 229910052581 Si3N4 Inorganic materials 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- HQVNEWCFYHHQES-UHFFFAOYSA-N silicon nitride Chemical compound N12[Si]34N5[Si]62N3[Si]51N64 HQVNEWCFYHHQES-UHFFFAOYSA-N 0.000 description 5
- 238000005245 sintering Methods 0.000 description 5
- 229910000577 Silicon-germanium Inorganic materials 0.000 description 4
- 230000008859 change Effects 0.000 description 4
- 239000012530 fluid Substances 0.000 description 4
- ORQBXQOJMQIAOY-UHFFFAOYSA-N nobelium Chemical compound [No] ORQBXQOJMQIAOY-UHFFFAOYSA-N 0.000 description 4
- 229910052763 palladium Inorganic materials 0.000 description 4
- 230000008569 process Effects 0.000 description 4
- 238000009792 diffusion process Methods 0.000 description 3
- 230000004907 flux Effects 0.000 description 3
- 239000008188 pellet Substances 0.000 description 3
- 238000010248 power generation Methods 0.000 description 3
- 230000035882 stress Effects 0.000 description 3
- 229910002665 PbTe Inorganic materials 0.000 description 2
- LEVVHYCKPQWKOP-UHFFFAOYSA-N [Si].[Ge] Chemical compound [Si].[Ge] LEVVHYCKPQWKOP-UHFFFAOYSA-N 0.000 description 2
- 238000006073 displacement reaction Methods 0.000 description 2
- 239000012772 electrical insulation material Substances 0.000 description 2
- 230000008642 heat stress Effects 0.000 description 2
- 229910001055 inconels 600 Inorganic materials 0.000 description 2
- 239000008204 material by function Substances 0.000 description 2
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 2
- 229910010271 silicon carbide Inorganic materials 0.000 description 2
- OCGWQDWYSQAFTO-UHFFFAOYSA-N tellanylidenelead Chemical compound [Pb]=[Te] OCGWQDWYSQAFTO-UHFFFAOYSA-N 0.000 description 2
- 230000008719 thickening Effects 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 1
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- 229910005329 FeSi 2 Inorganic materials 0.000 description 1
- -1 NiO Chemical class 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 238000013459 approach Methods 0.000 description 1
- 239000010962 carbon steel Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000000748 compression moulding Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 229910001026 inconel Inorganic materials 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- 229910021332 silicide Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- PORWMNRCUJJQNO-UHFFFAOYSA-N tellurium atom Chemical compound [Te] PORWMNRCUJJQNO-UHFFFAOYSA-N 0.000 description 1
- 239000010409 thin film Substances 0.000 description 1
- 239000002918 waste heat Substances 0.000 description 1
Landscapes
- Cooling Or The Like Of Semiconductors Or Solid State Devices (AREA)
- Laminated Bodies (AREA)
- Ceramic Products (AREA)
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、熱電変換素子用熱
応力緩和パッド及び熱電変換素子に関する。より詳しく
は、本発明は、高い出力密度の熱電変換素子を大量に用
いる大規模なエネルギ変換システムに適した熱電変換素
子用の熱応力緩和パッド及び熱電変換素子に関するもの
である。TECHNICAL FIELD The present invention relates to a thermal stress relaxation pad for a thermoelectric conversion element and a thermoelectric conversion element. More particularly, the present invention relates to a thermal stress relaxation pad for a thermoelectric conversion element and a thermoelectric conversion element suitable for a large-scale energy conversion system that uses a large amount of high power density thermoelectric conversion elements.
【０００２】[0002]
【従来の技術】従来、熱電変換素子用の熱応力緩和パッ
ドとして、熱伝導率が大きく弾性定数の小さな材料から
成る熱応力緩和材兼熱導伝体と電気絶縁材とを接合せず
に両者の組成割合を徐々に変化させた傾斜機能材料を含
むものが提案されている（特開平８−１８６２９５
号）。そして、この種の熱応力緩和パッドとして、例え
ば熱電素子に接する側が金属（熱応力緩和材兼熱導伝
体）、反対側の加熱ダクト又は冷却ダクトに接する側が
セラミック（電気絶縁材）となるように傾斜機能材料を
配置することが知られている。2. Description of the Related Art Conventionally, as a thermal stress relaxation pad for a thermoelectric conversion element, a thermal stress relaxation material / heat conductor made of a material having a large thermal conductivity and a small elastic constant and an electric insulating material are not bonded to each other. It has been proposed to include a functionally gradient material in which the composition ratio is gradually changed (Japanese Patent Laid-Open No. 8-186295).
issue). Then, as this type of thermal stress relaxation pad, for example, the side in contact with the thermoelectric element is metal (thermal stress relaxation material and heat conductor), and the side in contact with the opposite heating duct or cooling duct is ceramic (electrical insulation material). It is known to place a functionally graded material in the.
【０００３】即ち、図２に示す熱電変換素子１０１は、
Ｐ型とＮ型の熱電素子１０２の高温熱源側と低温熱源側
との両側から熱応力緩和パッド１０８，１０９で挟んで
構成されている。各熱応力緩和パッド１０８，１０９
は、熱応力緩和材兼熱導伝体（例えば銅）と電気絶縁材
（例えばアルミナ）とからなる傾斜機能材料１０３，１
０４と、熱電素子１０２の拡散防止層としてのグラファ
イト１０７より構成されている。各傾斜機能材料１０
３，１０４は、金属とセラミックとの組成割合を厚さ方
向に徐々に変化させ、熱電素子１０２側を金属（Ｃｕ）
層１０３ａ，１０４ａに、加熱ダクト１０５又は冷却ダ
クト１０６側をセラミック層１０３ｂ，１０４ｂとし、
各金属層１０３ａ，１０４ａと各セラミック層１０３
ｂ，１０４ｂとの間を金属とセラミックの組成割合を徐
々に変化させる層１０３ｃ，１０４ｃとしている。各傾
斜機能材料１０３，１０４は、粉末冶金法により製造さ
れる。That is, the thermoelectric conversion element 101 shown in FIG.
The P-type and N-type thermoelectric elements 102 are sandwiched by thermal stress relaxation pads 108 and 109 from both the high temperature heat source side and the low temperature heat source side. Each thermal stress relaxation pad 108, 109
Is a functionally graded material 103, 1 composed of a thermal stress relaxation material / heat conductor (for example, copper) and an electric insulating material (for example, alumina).
04 and graphite 107 as a diffusion prevention layer of the thermoelectric element 102. Each functionally graded material 10
3, 104, the composition ratio of metal and ceramic is gradually changed in the thickness direction, and the thermoelectric element 102 side is metal (Cu).
In the layers 103a and 104a, the heating duct 105 or the cooling duct 106 side is ceramic layers 103b and 104b,
Each metal layer 103a, 104a and each ceramic layer 103
Layers 103c and 104c for gradually changing the composition ratio of metal and ceramic are formed between the layers b and 104b. Each functionally gradient material 103, 104 is manufactured by a powder metallurgy method.
【０００４】なお、加熱ダクト１０５は例えばインコネ
ル６００により、冷却ダクト１０６は例えば銅により形
成されている。また、各熱電素子１０２と各Ｃｕ層１０
３ａ，１０４ａとの間には、熱電素子成分の拡散を防止
するグラファイト層１０７，１０７を介在させている。The heating duct 105 is made of, for example, Inconel 600, and the cooling duct 106 is made of, for example, copper. In addition, each thermoelectric element 102 and each Cu layer 10
Graphite layers 107, 107 for preventing diffusion of thermoelectric element components are interposed between the layers 3a, 104a.
【０００５】[0005]
【発明が解決しようとする課題】しかしながら、この熱
応力緩和パッドでは、熱源側接触面がセラミック層１０
３ｂ，１０４ｂで形成されているので、加熱ダクト１０
５又は冷却ダクト１０６に対する接合が困難となる問題
を有している。つまり、加熱ダクト１０５及び冷却ダク
ト１０６は金属製であり、これら各ダクト１０５，１０
６との接合面はセラミック製であるため、各傾斜機能材
料１０３，１０４と各ダクト１０５，１０６を接合する
際、材料の組み合わせによっては接合が困難な場合があ
った。However, in this thermal stress relaxation pad, the contact surface on the heat source side has the ceramic layer 10.
Since it is formed of 3b and 104b, the heating duct 10
5 or the cooling duct 106 is difficult to join. That is, the heating duct 105 and the cooling duct 106 are made of metal, and these ducts 105, 10
Since the joint surface with 6 is made of ceramic, when joining each functionally gradient material 103, 104 and each duct 105, 106, the joining may be difficult depending on the combination of materials.
【０００６】また、従来の熱応力緩和パッドの傾斜機能
材料１０３，１０４では、熱電素子１０２に接する面部
分が金属層１０３ａ，１０４ａとなっており、反対側の
加熱ダクト１０５又は冷却ダクト１０６に接する面部分
がセラミック層１０３ｂ，１０４ｂとなっているため、
粉末冶金法によって製造する際、焼結温度から室温にま
で冷却する過程で金属とセラミックの熱膨張差に起因す
る反りや亀裂を生じる欠点があった。このため、傾斜機
能材料の設計及び製作に特別の配慮が必要となってい
た。In the functionally graded materials 103 and 104 of the conventional thermal stress relaxation pad, the surface portions in contact with the thermoelectric element 102 are metal layers 103a and 104a, which are in contact with the heating duct 105 or the cooling duct 106 on the opposite side. Since the surface portions are the ceramic layers 103b and 104b,
When manufacturing by the powder metallurgy method, there is a defect that warpage and cracks are generated due to a difference in thermal expansion between metal and ceramic in the process of cooling from the sintering temperature to room temperature. Therefore, special consideration has been required in designing and manufacturing the functionally graded material.
【０００７】本発明は、加熱ダクトや冷却ダクト等の被
接合部材との接合を容易にし、且つ製造が容易で健全性
に優れた熱電変換素子用熱応力緩和パッドを提供すると
共に、当該熱応力緩和パッドを備える熱電変換素子を提
供することを目的とする。The present invention provides a thermal stress relaxation pad for a thermoelectric conversion element which facilitates joining with a member to be joined such as a heating duct and a cooling duct, is easy to manufacture, and is excellent in soundness. An object is to provide a thermoelectric conversion element including a relaxation pad.
【０００８】[0008]
【発明が解決するための手段】かかる目的を達成するた
め、請求項１記載の発明は、熱伝導率が大きく弾性定数
の小さな材料から成る熱応力緩和材兼熱導伝体と電気絶
縁材とを接合せずに両者の組成割合を徐々に変化させた
傾斜機能材料を含む熱電変換素子用熱応力緩和パッドに
おいて、傾斜機能材料が、内部に電気絶縁層を形成する
と共に、その電気絶縁層から熱源側接触面及び熱電素子
側接触面の両面に向かう厚み方向で組成割合を電気絶縁
材について減少させる一方、熱応力緩和材兼熱導伝体に
ついて増加させ、両接触面ではほぼ熱応力緩和材兼熱導
伝体が占めるように構成されている。In order to achieve the above object, the invention according to claim 1 provides a thermal stress relaxation material / heat conductor and an electric insulating material which are made of a material having a large thermal conductivity and a small elastic constant. In a thermal stress relaxation pad for a thermoelectric conversion element containing a functionally graded material in which the composition ratios of both are gradually changed without bonding, the functionally graded material forms an electrical insulating layer inside and from the electrical insulating layer. The composition ratio is reduced for the electrical insulating material in the thickness direction toward both the heat source side contact surface and the thermoelectric element side contact surface, while it is increased for the thermal stress relaxation material and heat conductor, and the thermal stress relaxation material is almost equal for both contact surfaces. It is configured to occupy a heat conductor.
【０００９】したがって、熱応力緩和パッドを粉末冶金
法によって製造する際、焼結温度から室温にまで冷却す
る過程で熱応力緩和材兼熱伝導体たる金属と電気絶縁材
たるセラミックの熱膨張差に起因する応力や変位を受け
ても、それが電気絶縁材たるセラミックの両側で発生す
るので、その影響が相殺されて反りや亀裂を招くことが
なくなる。特に、請求項３に記載の発明のように、傾斜
機能材料が、電気絶縁層と熱源側接触面との間の組成割
合と電気絶縁層と熱電素子側接触面との間の組成割合と
が同じで電気絶縁層を中心にして対称配置されている場
合には、熱膨張差による影響を完全に相殺することによ
って反りや亀裂などを防ぐことができる。また、傾斜機
能材料の接触面、特に熱源側接触面がほぼ熱応力緩和材
兼熱導伝体で占めるように構成されているため、熱源側
部材例えばダクト等との接合が容易となる。特に、傾斜
機能材料の熱源側及び熱電素子側の両接触面を金属とし
た請求項２記載の発明によれば、ダクトとの接合がより
容易となる。しかも、傾斜機能材料が従来よりも厚くな
る傾向にあるが、厚くなる原因の大部分が熱伝導率の極
めて高い熱応力緩和材兼熱導伝体たる金属が占めること
に起因していることから、従来の熱応力緩和パッドと同
等の熱流束が得られる。Therefore, when the thermal stress relaxation pad is manufactured by the powder metallurgy method, a difference in thermal expansion between the metal serving as the thermal stress relaxation material and the heat conductor and the ceramic serving as the electric insulating material is caused in the process of cooling from the sintering temperature to room temperature. Even if the resulting stress or displacement is generated on both sides of the ceramic, which is an electrical insulating material, the influences thereof are canceled out and warpage and cracks are not caused. In particular, as in the invention according to claim 3, in the functionally gradient material, the composition ratio between the electric insulating layer and the heat source side contact surface and the composition ratio between the electric insulating layer and the thermoelectric element side contact surface are In the case where they are the same and symmetrically arranged around the electric insulating layer, warping and cracks can be prevented by completely canceling out the influence of the difference in thermal expansion. Further, since the contact surface of the functionally gradient material, particularly the contact surface on the heat source side is almost occupied by the thermal stress relaxation material and the heat conductor, joining with the heat source side member such as a duct is facilitated. In particular, according to the invention of claim 2 in which both the heat source side and the thermoelectric element side contact surfaces of the functionally gradient material are made of metal, the joining with the duct becomes easier. Moreover, the functionally graded material tends to be thicker than before, but most of the reason for the thickening is due to the fact that the metal, which is a heat stress relaxation material and heat conductor with extremely high thermal conductivity, occupies it. A heat flux equivalent to that of the conventional thermal stress relaxation pad can be obtained.
【００１０】また、請求項４記載の発明は、請求項１か
ら３のいずれかに記載の熱電変換素子用熱応力緩和パッ
ドを熱電素子と高温側熱源及び低温側熱源との間にそれ
ぞれ設置することによって熱電変換素子を構成するよう
にしている。したがって、高温側熱源及び低温側熱源に
それぞれ接合されている熱応力緩和パッドは熱を伝える
媒体となって熱電素子の両側に温度差を発生させ、熱電
素子に発電させる。同時に、熱応力緩和パッドは傾斜機
能材料を備えており、当該傾斜機能材料に生じる熱応力
は特定部分に集中せずに分散する。Further, the invention according to claim 4 is to install the thermal stress relaxation pad for thermoelectric conversion element according to any one of claims 1 to 3 between the thermoelectric element and the high temperature side heat source and the low temperature side heat source, respectively. By doing so, the thermoelectric conversion element is configured. Therefore, the thermal stress relaxation pads respectively joined to the high temperature side heat source and the low temperature side heat source serve as a medium for transmitting heat to generate a temperature difference between both sides of the thermoelectric element and cause the thermoelectric element to generate electricity. At the same time, the thermal stress relaxation pad includes the functionally graded material, and the thermal stress generated in the functionally graded material is dispersed without being concentrated in a specific portion.
【００１１】[0011]
【発明の実施の形態】以下、本発明の構成を図面に示す
最良の形態に基づいて詳細に説明する。BEST MODE FOR CARRYING OUT THE INVENTION The structure of the present invention will be described below in detail based on the best mode shown in the drawings.
【００１２】図１に、本発明に係る対称型傾斜機能材料
を用いた熱応力緩和パッドを採用した熱電変換素子の実
施形態の一例を示す。そして、この熱電変換素子１の主
要構成は、例えばビスマス−テルル（ＢｉＴｅ）半導体
素子を熱電素子２とし、その両側に熱応力緩和パッド
３，４を配置したものである。FIG. 1 shows an example of an embodiment of a thermoelectric conversion element adopting a thermal stress relaxation pad using a symmetrical functionally graded material according to the present invention. The main configuration of the thermoelectric conversion element 1 is, for example, a bismuth-tellurium (BiTe) semiconductor element as a thermoelectric element 2 and thermal stress relaxation pads 3 and 4 arranged on both sides thereof.
【００１３】なお、熱電素子２としては、ビスマス−テ
ルル半導体素子の他に、シリコン−ゲルマニウム（Ｓｉ
Ｇｅ）半導体素子、鉛−テルル（ＰｂＴｅ）半導体素子
等の使用が可能である。これらの半導体素子のうち何れ
を選択するかは、使用温度領域等に応じて決定される
（表１）。いずれの素子も、正孔の濃度が高いＰ型半導
体と電子の濃度が高いＮ型半導体より成り、両者の組み
合わせにより起電力を発生する。実際には、複数対のＰ
型半導体とＮ型半導体を電気的に直列に接続することに
より出力を増大させる。As the thermoelectric element 2, in addition to the bismuth-tellurium semiconductor element, silicon-germanium (Si
A Ge) semiconductor element, a lead-tellurium (PbTe) semiconductor element, or the like can be used. Which of these semiconductor elements is selected is determined according to the operating temperature range and the like (Table 1). Each element is composed of a P-type semiconductor having a high hole concentration and an N-type semiconductor having a high electron concentration, and an electromotive force is generated by a combination of both. In fact, there are multiple pairs of P
The output is increased by electrically connecting the type semiconductor and the N-type semiconductor in series.
【００１４】[0014]
【表１】
高温側熱応力緩和パッド３及び低温側熱応力緩和パッド
４は、傾斜機能材料５，６と熱電素子２の拡散防止層と
してのグラファイト層７，８より構成されている。各傾
斜機能材料５，６は、電気絶縁材と熱応力緩和材兼熱導
伝体を接合せずに両者の組成割合を徐々に変化させた熱
伝導性のものである。電気絶縁材は、例えばアルミナ
（Ａｌ2 Ｏ3 ）等のセラミックであり、熱応力緩和材兼
熱導伝体は、熱伝導率が大きく弾性定数の小さな材料例
えば銅（Ｃｕ）等の金属である。[Table 1] The high temperature side thermal stress relaxation pad 3 and the low temperature side thermal stress relaxation pad 4 are composed of functionally graded materials 5 and 6 and graphite layers 7 and 8 as diffusion preventing layers of the thermoelectric element 2. Each of the functionally graded materials 5 and 6 is a heat conductive material in which the electrical insulating material and the thermal stress relaxation material / heat conductor are not joined and the composition ratio of both is gradually changed. The electric insulating material is a ceramic such as alumina (Al 2 O 3 ), and the thermal stress relaxation material / heat conductor is a material having a large thermal conductivity and a small elastic constant, for example, a metal such as copper (Cu). .
【００１５】各傾斜機能材料５，６は、内部に電気絶縁
層５ａ，６ａを形成し、この電気絶縁層５ａ，６ａから
外側の熱源側接触面及び熱電素子側接触面の両面に向か
う厚み方向で電気絶縁材と熱応力緩和材兼熱導伝体との
組成割合、即ちセラミックと銅との組成割合を、アルミ
ナについて減少させる一方、銅について増加させるよう
に変化させている。例えば、本実施形態の場合、各傾斜
機能材料５，６は厚み方向の中程にアルミナ１００％の
電気絶縁層（以下アルミナ層と呼ぶ）５ａ，６ａが、両
外側の熱源と接する面部分には銅１００％の熱応力緩和
材兼熱導伝体の層（以下Ｃｕ層と呼ぶ）５ｂ，５ｂ、６
ｂ，６ｂが、またそれらの間にはアルミナと銅の組成割
合が連続して又は段階的に徐々に変化する層５ｃ，６ｃ
が形成されている。Each of the functionally gradient materials 5 and 6 has an electric insulating layer 5a and 6a formed therein, and a thickness direction from the electric insulating layer 5a and 6a to both of the outer heat source side contact surface and the thermoelectric element side contact surface. The composition ratio of the electrical insulating material and the thermal stress relaxation material / heat conductor, that is, the composition ratio of ceramic and copper is changed so as to decrease with respect to alumina and increase with respect to copper. For example, in the case of the present embodiment, in each of the functionally graded materials 5 and 6, in the middle of the thickness direction, the electric insulating layers 5a and 6a of 100% alumina (hereinafter referred to as alumina layers) are formed on the surface portions in contact with the heat sources on both outer sides. Is a layer of thermal stress relaxation material / heat conductor made of 100% copper (hereinafter referred to as Cu layer) 5b, 5b, 6
b, 6b, and layers 5c, 6c between which the composition ratio of alumina and copper gradually changes continuously or stepwise.
Are formed.
【００１６】各グラファイト層７，８は各傾斜機能材料
５，６と熱電素子２との間に配置され、熱電素子２の成
分の拡散を防止する。また、各グラファイト層７，８に
接する各傾斜機能材料５，６のＣｕ層５ｂ，６ｂは、各
熱電素子２を電気的に直列に接続する電極としても機能
する。The graphite layers 7 and 8 are arranged between the functionally graded materials 5 and 6 and the thermoelectric element 2 to prevent the components of the thermoelectric element 2 from diffusing. Further, the Cu layers 5b and 6b of the functionally graded materials 5 and 6 in contact with the graphite layers 7 and 8 also function as electrodes for electrically connecting the thermoelectric elements 2 in series.
【００１７】高温側熱応力緩和パッド３は加熱ダクト９
に、低温側熱応力緩和パッド４は冷却ダクト１０にそれ
ぞれ接合されている。加熱ダクト９は例えばインコネル
６００により、冷却ダクト１０は例えば銅によりそれぞ
れ形成されている。加熱ダクト９内には高温の流体が、
冷却ダクト１０内には低温の流体が流れており、各熱応
力緩和パッド３，４が熱を伝える媒体となって各熱電素
子２の両側に温度差を生じさせる。The high temperature side thermal stress relaxation pad 3 is a heating duct 9
Further, the low temperature side thermal stress relaxation pads 4 are respectively joined to the cooling ducts 10. The heating duct 9 is made of, for example, Inconel 600, and the cooling duct 10 is made of, for example, copper. In the heating duct 9, high temperature fluid,
A low-temperature fluid is flowing in the cooling duct 10, and the thermal stress relaxation pads 3 and 4 serve as a medium for transmitting heat to cause a temperature difference between both sides of each thermoelectric element 2.
【００１８】なお、表２に熱応力緩和材兼熱導伝体とし
て適する材料の物性値を示す。Table 2 shows the physical property values of materials suitable as a thermal stress relaxation material and a heat conductor.
【００１９】[0019]
【表２】
表２からも明らかなように、熱伝導率λに対する弾性定
数Ｅの比率（Ｅ／λ）は、銅が非常に小さい。したがっ
て、熱伝導性の熱応力緩和材兼熱導伝体として銅を使用
すると、高い熱伝導性能を維持しながら熱応力を緩和す
ることができる。しかしながら、使用温度の高いＳｉＧ
ｅ素子等を熱電素子２として使用する場合には、高温側
の熱応力緩和パッド３の使用温度が銅の融点に接近する
ため、低温側の熱応力緩和パッド４についてのみ銅を使
用し、高温側の熱応力緩和パッド３については銅に次い
で性能の優れたパラジウムを使用することが好ましい。
ただし、熱応力緩和材兼熱導伝体として使用する材料
は、必ずしも銅やパラジウムに限るものではないことは
勿論である。この場合、熱伝導率が大きく弾性定数の小
さいもの、即ち熱伝導率に対する弾性定数の比率がより
小さいものがより好ましい。また、この性質を満たすも
のであれば金属に必ずしも限定されない。[Table 2] As is clear from Table 2, copper has a very small ratio (E / λ) of the elastic constant E to the thermal conductivity λ. Therefore, when copper is used as the heat conductive thermal stress relaxation material and heat conductor, the thermal stress can be relaxed while maintaining high thermal conductivity. However, SiG has a high operating temperature
When an e element or the like is used as the thermoelectric element 2, since the operating temperature of the high temperature side thermal stress relaxation pad 3 approaches the melting point of copper, copper is used only for the low temperature side thermal stress relaxation pad 4, For the thermal stress relaxation pad 3 on the side, it is preferable to use palladium, which has excellent performance next to copper.
However, it goes without saying that the material used as the thermal stress relaxation material and the heat conductor is not necessarily limited to copper or palladium. In this case, a material having a large thermal conductivity and a small elastic constant, that is, a material having a smaller ratio of the elastic constant to the thermal conductivity is more preferable. Further, the material is not necessarily limited to metal as long as it satisfies this property.
【００２０】また、電気絶縁材としては、アルミナの他
に窒化珪素や炭化珪素等のセラミックを適用することが
できる。炭化珪素等の各種のセラミックは、熱伝導性が
良く、熱による変形が少なくしかも電気絶縁性に優れて
いるため好ましい材料といえる。ただし、電気絶縁材と
して使用する材料は、必ずしもアルミナや窒化珪素等の
セラミックに限るものではないことは勿論である。As the electric insulating material, ceramics such as silicon nitride and silicon carbide can be used in addition to alumina. Various ceramics such as silicon carbide are preferable materials because they have good thermal conductivity, little deformation by heat, and excellent electrical insulation. However, it goes without saying that the material used as the electrical insulating material is not necessarily limited to ceramics such as alumina and silicon nitride.
【００２１】次に、表３に熱電変換素子１の各材料の室
温における線膨張率を示す。Next, Table 3 shows the linear expansion coefficient of each material of the thermoelectric conversion element 1 at room temperature.
【００２２】[0022]
【表３】
表３からも明らかなように、熱応力緩和材兼熱導伝体
（金属）と電気絶縁材（セラミック）は線膨張率が２倍
以上異なる。線膨張率は温度により変化するが、金属と
セラミックとの線膨張率が２倍以上異なることは変わら
ない。したがって、両者を直接接合することは難しく、
仮に接合できたとしても熱電変換素子を使用した発電シ
ステムの起動・停止による熱サイクルにより亀裂を生じ
易い。[Table 3] As is apparent from Table 3, the linear expansion coefficient of the thermal stress relaxation material / heat conductor (metal) is different from that of the electrical insulation material (ceramic) by a factor of two or more. Although the coefficient of linear expansion changes depending on the temperature, the fact that the coefficients of linear expansion of metal and ceramic differ by more than two times does not change. Therefore, it is difficult to directly bond the two,
Even if they could be joined, cracks are likely to occur due to the heat cycle due to the start / stop of the power generation system using the thermoelectric conversion element.
【００２３】一方、銅やパラジウム（熱応力緩和材兼熱
導伝体）、アルミナや窒化珪素（電気絶縁材）は、いず
れも粉末の状態で入手することができる。したがって、
粉末冶金法により傾斜機能材料５，６を製造することが
できる。熱応力緩和材兼熱導伝体と電気絶縁材の組成割
合を徐々に変化させた傾斜機能材料５，６は、両材料の
接合界面を存在させないために、熱応力の緩和が容易で
あり熱応力緩和パッドとしての機能を長期間に亘って維
持できる。On the other hand, copper, palladium (thermal stress relaxation material and heat conductor), alumina, and silicon nitride (electrical insulating material) are all available in powder form. Therefore,
The functionally gradient materials 5 and 6 can be manufactured by the powder metallurgy method. The functionally graded materials 5 and 6 in which the composition ratios of the thermal stress relaxation material / heat conductor and the electric insulating material are gradually changed do not have a joint interface between the two materials, so that the thermal stress can be easily relaxed. The function as a stress relaxation pad can be maintained for a long period of time.
【００２４】なお、銅又はパラジウムとアルミナ又は窒
化珪素とからなる傾斜機能材料５，６の粉末冶金法によ
る製造方法は以下の通りである。即ち、先ず、２本のノ
ズルから粉末を噴射する装置を使用し、一方のノズルか
ら銅又はパラジウムの粉末を型内に噴射させ、他方のノ
ズルからアルミナ又は窒化珪素の粉末を型内に噴射させ
る。この場合、両ノズルの噴射比率を制御することによ
り各粉末の充填割合を厚さ方向内側から両外側に向けて
それぞれ徐々に変化させた層状ないし板状のペレット
（粉末の塊）を造る。ペレットの圧縮成形後、当該ペレ
ットを炉で加熱して焼結することにより傾斜機能材料
５，６を得る。The method for producing the functionally graded materials 5 and 6 made of copper or palladium and alumina or silicon nitride by the powder metallurgy method is as follows. That is, first, using a device for injecting powder from two nozzles, one nozzle injects copper or palladium powder into the mold, and the other nozzle injects alumina or silicon nitride powder into the mold. . In this case, layer-like or plate-like pellets (powder agglomerates) in which the filling ratio of each powder is gradually changed from the inside in the thickness direction to both outsides by controlling the injection ratio of both nozzles are produced. After compression molding of the pellets, the functionally gradient materials 5 and 6 are obtained by heating and sintering the pellets in a furnace.
【００２５】このようにして製造される傾斜機能材料
５，６では、線膨張率が大きく異なる熱応力緩和材兼熱
導伝体と絶縁性材料との組成割合を徐々に変化させてい
るので、各熱応力緩和パッド３，４としてしようした場
合には内部に発生する熱応力を特定箇所に集中させるこ
となく分散させることができる。In the functionally graded materials 5 and 6 manufactured in this way, the composition ratios of the thermal stress relaxation material / heat conductor and the insulating material, which differ greatly in linear expansion coefficient, are gradually changed. When the thermal stress relaxation pads 3 and 4 are used, the thermal stress generated inside can be dispersed without being concentrated at a specific location.
【００２６】また、傾斜機能材料５，６の電気絶縁材と
熱応力緩和材兼熱導伝体との組成割合を厚み方向の内側
から両外側に向けてそれぞれ変化させているので、傾斜
機能材料５，６の厚さ方向全体からみて当該組成割合の
変化の方向を途中で逆に、即ち電気絶縁材と熱応力緩和
材兼熱導伝体の比が増加する傾向にあるか減少する傾向
にあるかを途中で変えることができる。つまり、傾斜機
能材料５，６がセラミック層（電気絶縁材であるアルミ
ナ層５ａ，６ａ）の両側に金属層（熱応力緩和材兼熱導
伝体であるＣｕ層５ｂ，６ｂ）を配置する構造となり、
製造時の焼結温度から室温までの冷却過程において、金
属とセラミックの熱膨張差に起因した反りや亀裂の発生
防止を図ることができる。このため、傾斜機能材料５，
６の製造が容易になってコスト低減が可能になると共
に、健全性も改善されて品質的に安定したものを得るこ
とができる。Further, since the composition ratios of the electric insulating material of the functionally graded materials 5 and 6 and the thermal stress relaxation material / heat conductor are changed from the inner side to the outer side in the thickness direction, respectively, the functionally graded material is obtained. When viewed from the entire thickness direction of 5 and 6, the direction of the change of the composition ratio is reversed on the way, that is, the ratio of the electrical insulating material to the thermal stress relaxation material / heat conductor tends to increase or decrease. You can change what you have. That is, a structure in which the functionally graded materials 5 and 6 dispose the metal layers (the Cu layers 5b and 6b which are the thermal stress relaxation materials and the heat conductors) on both sides of the ceramic layers (the alumina layers 5a and 6a which are the electric insulating materials). Next to
In the cooling process from the sintering temperature to the room temperature during manufacturing, it is possible to prevent warpage and cracks due to the difference in thermal expansion between metal and ceramic. Therefore, the functionally gradient material 5,
6 can be easily manufactured and cost can be reduced, and the soundness can be improved and a stable product can be obtained.
【００２７】さらに、各傾斜機能材料５，６の両外側を
金属層としているので、即ち各傾斜機能材料５，６の両
外側の材料を加熱ダクト９又は冷却ダクト１０の材料と
同一のもの又は線膨張率が近いものにすることができる
ため、高温側熱応力緩和パッド３と加熱ダクト９、低温
側熱応力緩和パッド４と冷却ダクト１０の接合が容易に
なると共に、これらの接合強度を増大させることができ
る。特に、各傾斜機能材料５，６の両外側にＣｕ層５
ｂ，６ｂを配置した場合には、冷却ダクト１０について
は同一の材料を使用することなるので、また、加熱ダク
ト９については線膨張率が近い材料を使用することにな
るので、これらの接合をより一層容易に且つ強くするこ
とができる。Furthermore, since the outer sides of the respective gradient functional materials 5 and 6 are made of metal layers, that is, the materials on both outer sides of the respective functional gradient materials 5 and 6 are the same as those of the heating duct 9 or the cooling duct 10. Since the coefficients of linear expansion can be made close to each other, the high temperature side thermal stress relaxation pad 3 and the heating duct 9 and the low temperature side thermal stress relaxation pad 4 and the cooling duct 10 can be easily bonded and the bonding strength of these can be increased. Can be made. In particular, the Cu layer 5 is formed on both outer sides of each of the functionally gradient materials 5,
When b and 6b are arranged, the same material is used for the cooling duct 10 and a material having a linear expansion coefficient close to that of the heating duct 9 is used. It can be made easier and stronger.
【００２８】なお、熱電変換素子としてシリコン−ゲル
マニウム（ＳｉＧｅ）素子を採用した宇宙用の直接発電
システムでは、例えば加熱ダクト面温度は８４０℃、冷
却ダクト面温度は５３０℃程度である。また、地上で使
用する熱電変換システムでは、９００℃から室温付近ま
であらゆる温度の熱源を採用することができる。この場
合、これらの熱源で加熱した適当な作動流体を加熱ダク
ト９に流し、冷却ダクト１０には室温の水を流すことが
一般的である。In a space direct power generation system employing a silicon-germanium (SiGe) element as a thermoelectric conversion element, for example, the heating duct surface temperature is 840 ° C and the cooling duct surface temperature is about 530 ° C. Further, in the thermoelectric conversion system used on the ground, a heat source of any temperature from 900 ° C. to around room temperature can be adopted. In this case, it is general that a suitable working fluid heated by these heat sources is caused to flow in the heating duct 9 and water at room temperature is caused to flow in the cooling duct 10.
【００２９】また、本発明の熱応力緩和パッド３，４の
各傾斜機能材料５，６は、電気絶縁材の層５ａ，６ａを
挟んで熱源側と熱電素子側とにそれぞれ熱応力緩和材兼
熱導伝体と電気絶縁材とを接合させずにその組成割合を
漸次変化させる層５ｃ，６ｃと、熱応力緩和材兼熱導伝
体からのみ成る層５ｂ，６ｂを有しているので、図２に
示す従来の熱応力緩和パッドに比べて厚くなる傾向があ
る。しかしながら、各傾斜機能材料５，６は大部分が熱
伝導率の極めて高い銅より構成されており、当該傾斜機
能材料５，６の内部での温度落差は、従来の傾斜機能材
料に比べて僅かに大きい程度に抑えられ大差がない。実
験によれば、熱電素子２に与えられる温度落差は、本発
明に係る熱応力緩和パッド３，４の方が従来のものに比
べて僅かに（１〜２％）小さくなる程度である。したが
って、熱電素子２の出力も僅かに（２〜３％）小さくな
る程度である。即ち、本発明に係る熱応力緩和パッド
３，４は、従来の熱応力緩和パッドとほぼ同等の熱流束
を確保でき、ほぼ同等な発電が可能である。The functionally graded materials 5 and 6 of the thermal stress relaxation pads 3 and 4 of the present invention also serve as thermal stress relaxation materials on the heat source side and the thermoelectric element side with the electric insulating material layers 5a and 6a sandwiched therebetween. Since it has layers 5c and 6c for gradually changing the composition ratio without joining the heat conductor and the electric insulating material, and layers 5b and 6b composed only of the thermal stress relaxation material and the heat conductor, It tends to be thicker than the conventional thermal stress relaxation pad shown in FIG. However, most of the functionally graded materials 5 and 6 are made of copper having an extremely high thermal conductivity, and the temperature drop inside the functionally graded materials 5 and 6 is smaller than that of the conventional functionally graded materials. It is suppressed to a large degree and there is no big difference. According to the experiment, the temperature difference applied to the thermoelectric element 2 is slightly smaller (1-2%) in the thermal stress relaxation pads 3 and 4 according to the present invention than in the conventional one. Therefore, the output of the thermoelectric element 2 is slightly small (2 to 3%). That is, the thermal stress relaxation pads 3 and 4 according to the present invention can secure a heat flux almost equal to that of the conventional thermal stress relaxation pad, and can generate substantially the same power.
【００３０】なお、上述の形態は本発明の好適な形態の
一例ではあるがこれに限定されるものではなく、本発明
の要旨を逸脱しない範囲において種々変形実施可能であ
る。例えば、本発明の用途としては、宇宙用原子炉にお
ける直接発電システムの他に、自動車等のエンジンや工
場の炉等から排気される高温のガスに使用したり、工場
や一般の原子炉等から排出される各種の高温排熱水等に
適用することができる。The above-mentioned embodiment is an example of the preferred embodiment of the present invention, but the present invention is not limited to this, and various modifications can be made without departing from the gist of the present invention. For example, as an application of the present invention, in addition to a direct power generation system in a space reactor, it can be used for high-temperature gas exhausted from an engine of an automobile or a furnace of a factory, or from a factory or a general reactor. It can be applied to various high-temperature waste heat water discharged.
【００３１】また、熱電素子２としては、熱エネルギー
を電力に変換することが可能なものであれば他のもので
も良い。例えば、ＳｉＧｅの他に、ＦｅＳｉ2 、ＣｒＳ
ｉ2等の金属珪化物、ＮｉＯ等の金属酸化物、鉛−テル
ル（ＰｂＴｅ）やビスマス−テルル（ＢｉＴｅ）等のテ
ルル系の半導体等があり、使用温度領域等に応じて適宜
選択される。また、これらの物質をアモルファス状の薄
膜とすることも可能である。The thermoelectric element 2 may be any other element as long as it can convert heat energy into electric power. For example, in addition to SiGe, FeSi 2 , CrS
There are metal silicides such as i 2 and the like, metal oxides such as NiO, and tellurium-based semiconductors such as lead-tellurium (PbTe) and bismuth-tellurium (BiTe), which are appropriately selected according to the operating temperature range and the like. It is also possible to use these substances as an amorphous thin film.
【００３２】また、上述の熱電変換素子１用の熱応力緩
和パッド３，４の傾斜機能材料５，６は、内部にアルミ
ナ１００％の電気絶縁材層５ａ，６ａを形成し、両側の
熱源側接触面と熱電素子側接触面とを銅１００％の熱応
力緩和材兼熱伝導体層５ｂ，６ｂにしているが、必ずし
もこれに限られず、実質的に電気絶縁ができる範囲で熱
応力緩和材兼熱伝導体を含んだり、あるいは実質的にダ
クトとの接合が可能な範囲で電気絶縁材を含むことも可
能であることは勿論である。Further, the functionally graded materials 5 and 6 of the thermal stress relaxation pads 3 and 4 for the thermoelectric conversion element 1 described above have the electrical insulating material layers 5a and 6a of 100% alumina formed therein, and the heat source side on both sides. Although the contact surface and the contact surface on the thermoelectric element side are made of the thermal stress relaxation material / heat conductor layers 5b and 6b made of 100% copper, the present invention is not necessarily limited to this, and the thermal stress relaxation material is substantially within a range where electrical insulation can be achieved. Needless to say, it is possible to include a heat conductor as well as an electric insulating material in a range where it can be substantially joined to the duct.
【００３３】また、各傾斜機能材料５，６の各ダクト
９，１０側の面と各熱電素子２側の面とを必ずしもとも
に金属の層で構成する必要はなく、各ダクト９，１０側
の面は各ダクト９，１０との接合性が良好で熱伝導性に
優れた材料の層であれば良く、また各熱電素子２側の面
はグラファイト層７，８との接合性が良好で導電性に優
れた材料の層であれば良い。It is not always necessary that the surfaces of the gradient functional materials 5 and 6 on the side of the ducts 9 and 10 and the surface on the side of the thermoelectric elements 2 are both made of metal layers. The surface may be a layer of a material having good bonding properties with the ducts 9 and 10 and excellent thermal conductivity, and the surface on the side of each thermoelectric element 2 has good bonding properties with the graphite layers 7 and 8 and is electrically conductive. Any material layer having excellent properties may be used.
【００３４】また、必ずしも両外側のＣｕ層５ｂ，６ｂ
の中央にアルミナ層５ａ，６ａを形成する必要はなく、
いずれか一方のＣｕ層５ｂ，６ｂ側に偏らせた位置にア
ルミナ層５ａ，６ａを形成しても良い。即ち、両側の層
５ｃ，６ｃの厚さを同一にする必要はなく、互いに変え
ても良い。また、各層５ｃ，６ｃの前記組成割合の変化
の割合を、必ずしも熱電素子２側と加熱ダクト９又は冷
却ダクト１０側とで同一にする必要はなく、変化させて
も良いことは勿論である。Further, the Cu layers 5b and 6b on both outer sides are not always required.
It is not necessary to form the alumina layers 5a and 6a in the center of
The alumina layers 5a and 6a may be formed at the positions deviated to one of the Cu layers 5b and 6b. That is, the thicknesses of the layers 5c and 6c on both sides need not be the same, and may be different from each other. Further, the rate of change in the composition ratio of each of the layers 5c and 6c does not necessarily have to be the same on the thermoelectric element 2 side and the heating duct 9 or the cooling duct 10 side, and may of course be changed.
【００３５】また、高温側熱応力緩和パッド３を加熱ダ
クト９に接合した場合、即ち熱源として加熱ダクト９を
使用する場合について説明したが、熱源としては加熱ダ
クト９に限るものではなく、炉の外壁や内燃エンジンの
熱源等に高温側熱応力緩和パッドを接合しても良い。Further, the case where the high temperature side thermal stress relaxation pad 3 is joined to the heating duct 9, that is, the case where the heating duct 9 is used as the heat source has been described, but the heat source is not limited to the heating duct 9, and the furnace The high temperature side thermal stress relaxation pad may be joined to the outer wall or the heat source of the internal combustion engine.
【００３６】さらに、低温側熱応力緩和パッド４を冷却
ダクト１０に接合した場合、即ち冷却ダクト１０内の流
体に放熱する場合について説明したが、冷却ダクト１０
に代えて、放熱フィンを備えるプレート等の放熱手段に
低温側熱応力緩和パッド４を接合しても良い。Further, the case where the low temperature side thermal stress relaxation pad 4 is joined to the cooling duct 10, that is, the heat is radiated to the fluid in the cooling duct 10 has been described.
Instead of this, the low temperature side thermal stress relaxation pad 4 may be joined to a heat radiating means such as a plate having a heat radiating fin.
【００３７】[0037]
【発明の効果】以上説明したように、請求項１記載の熱
電変換素子用熱応力緩和パッドによれば、熱応力緩和パ
ッドを粉末冶金法によって製造する際、焼結温度から室
温にまで冷却する過程で熱応力緩和材兼熱伝導体たる金
属と電気絶縁材たるセラミックの熱膨張差に起因する応
力や変位を受けても、それが電気絶縁材たるセラミック
の両側で発生するので、その影響が相殺されて反りや亀
裂を招くことがなくなる。したがって、熱応力緩和パッ
ドとしての機能、即ち熱応力の緩和力及び耐久性を高度
に維持しつつ、製造時のそりや亀裂等の発生防止を図る
ができる。このため、製造が容易になって生産コストを
安くすることができると共に、構造健全性及び品質安定
性を向上させることができる。As described above, according to the thermal stress relaxation pad for a thermoelectric conversion element of claim 1, when the thermal stress relaxation pad is manufactured by the powder metallurgy method, it is cooled from the sintering temperature to room temperature. In the process, even if stress or displacement due to the difference in thermal expansion between the metal, which is the thermal stress relaxation material / heat conductor, and the ceramic, which is the electrical insulating material, is generated on both sides of the ceramic, which is the electrical insulating material, that effect is affected. It will not be offset and cause warpage or cracks. Therefore, it is possible to prevent warpage, cracks, and the like from occurring during manufacturing while maintaining a high function as a thermal stress relaxation pad, that is, thermal stress relaxation force and durability. For this reason, manufacturing can be facilitated, the production cost can be reduced, and the structural integrity and quality stability can be improved.
【００３８】また、傾斜機能材料の接触面、特に熱源側
接触面がほぼ熱応力緩和材兼熱導伝体で占めるように構
成されているため、熱源側部材例えばダクト等との接合
が可能となる。換言すると、傾斜機能材料の両外側の部
分が主として熱応力緩和材兼熱導伝体となるので、炭素
鋼、ステンレス鋼、インコネル、アルミニウム及び銅等
想定される殆どのダクト材料との接合が可能になる。こ
のため、被接合部材に対する制約を減少させることがで
きると共に、接合強度を増大することができる。Further, since the contact surface of the functionally graded material, especially the contact surface on the heat source side is almost occupied by the thermal stress relaxation material and the heat conductor, it is possible to join with the heat source side member such as a duct. Become. In other words, the parts on both outsides of the functionally graded material mainly serve as thermal stress relaxation materials and heat conductors, so that it is possible to join with almost all assumed duct materials such as carbon steel, stainless steel, Inconel, aluminum and copper. become. Therefore, it is possible to reduce the restrictions on the members to be joined and to increase the joining strength.
【００３９】しかも、傾斜機能材料が従来よりも厚くな
る傾向にあるが、厚くなる原因の大部分が熱伝導率の極
めて高い熱応力緩和材兼熱導伝体たる金属が占めること
に起因していることから、従来の熱応力緩和パッドと同
等の熱流束が得られる。Moreover, the functionally graded material tends to be thicker than before, but most of the reason for the thickening is due to the fact that the metal, which is a heat stress relaxation material and a heat conductor, having an extremely high thermal conductivity occupies it. Therefore, a heat flux equivalent to that of the conventional thermal stress relaxation pad can be obtained.
【００４０】また、特に、請求項２記載の発明によれ
ば、傾斜機能材料の熱源側及び熱電素子側の両接触面を
金属としているので、ダクトとの接合がより容易とな
る。Further, according to the second aspect of the invention, since the contact surfaces of the functionally gradient material on the heat source side and the thermoelectric element side are made of metal, joining with the duct becomes easier.
【００４１】また、請求項３に記載の発明のよれば、傾
斜機能材料が、電気絶縁層と熱源側接触面との間の組成
割合と電気絶縁層と熱電素子側接触面との間の組成割合
とが同じで電気絶縁層を中心にして対称配置されている
ので、熱膨張差による影響を完全に相殺することによっ
て反りや亀裂などを防ぐことができる。According to the third aspect of the present invention, the functionally gradient material has a composition ratio between the electric insulating layer and the heat source side contact surface and a composition between the electric insulating layer and the thermoelectric element side contact surface. Since the ratio is the same and symmetrically arranged around the electric insulating layer, it is possible to prevent warpage and cracks by completely offsetting the influence of the difference in thermal expansion.
【００４２】また、請求項４記載の発明は、請求項１か
ら３のいずれかに記載の熱電変換素子用熱応力緩和パッ
ドを熱電素子と高温側熱源及び低温側熱源との間にそれ
ぞれ設置することによって熱電変換素子を構成するよう
にしているので、熱電変換素子の製造が容易になって製
生産コストを安くすることができると共に、品質安定性
及び耐久性を向上させることができ、さらに、熱電変換
素子の設置の容易化を図ることができる。According to a fourth aspect of the present invention, the thermal stress relaxation pad for a thermoelectric conversion element according to any one of the first to third aspects is provided between the thermoelectric element and the high temperature side heat source and the low temperature side heat source, respectively. Since the thermoelectric conversion element is configured by the above, it is possible to easily manufacture the thermoelectric conversion element and reduce the production cost, and it is possible to improve quality stability and durability, and further, It is possible to facilitate the installation of the thermoelectric conversion element.
【図１】本発明に係る熱応力緩和パッドを適用した熱電
変換素子の実施形態の一例を示す断面図である。FIG. 1 is a cross-sectional view showing an example of an embodiment of a thermoelectric conversion element to which a thermal stress relaxation pad according to the present invention is applied.
【図２】従来の熱電変換素子の断面図である。FIG. 2 is a cross-sectional view of a conventional thermoelectric conversion element.
１ 熱電変換素子 ２ 熱電素子 ３，４ 熱応力緩和パッド ５，６ 傾斜機能材料 1 Thermoelectric conversion element 2 thermoelectric elements 3,4 Thermal stress relaxation pad 5,6 Functionally graded material
───────────────────────────────────────────────────── フロントページの続き (72)発明者 エム． コプフ ドイツ国 スタットガルト デー− 70550，プファッフェンヴァルドゥリン グ 31， フォルシュンクス インステ ィテュート フュア ケルンテヒニーク ウント エネルギーヴァンドゥルング エー．ファオ. (58)調査した分野(Int.Cl.7，ＤＢ名) H01L 35/32 H01L 35/26 H01L 35/30 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor M. Kopf Germany Statgard Day 70550, Pfaffenwaldruing 31, Forschungs Institute Institute Cologne-Techinique und Energy Van Durung A. Phao. (58) Fields investigated (Int.Cl. 7 , DB name) H01L 35/32 H01L 35/26 H01L 35/30
Claims (4)
から成る熱応力緩和材兼熱導伝体と電気絶縁材とを接合
せずに両者の組成割合を徐々に変化させた傾斜機能材料
を含む熱電変換素子用熱応力緩和パッドにおいて、前記
傾斜機能材料は、内部に電気絶縁層を形成すると共に、
その電気絶縁層から熱源側接触面及び熱電素子側接触面
の両面に向かう厚み方向で前記組成割合を電気絶縁材に
ついて減少させる一方、熱応力緩和材兼熱導伝体につい
て増加させ、前記両接触面ではほぼ前記熱応力緩和材兼
熱導伝体が占めることを特徴とする熱電変換素子用熱応
力緩和パッド。1. A functionally graded material obtained by gradually changing the composition ratio of a thermal stress relaxation material / heat conductor made of a material having a large thermal conductivity and a small elastic constant and an electric insulating material without joining them. In the thermal stress relaxation pad for thermoelectric conversion element including, the functionally gradient material, while forming an electrical insulating layer inside,
The composition ratio is reduced for the electrical insulating material in the thickness direction from the electrical insulation layer toward both the heat source side contact surface and the thermoelectric element side contact surface, while the thermal stress relaxation material and the heat conductor are increased, and the both contact A thermal stress relaxation pad for a thermoelectric conversion element, characterized in that the surface is almost occupied by the thermal stress relaxation material and the heat conductor.
側の両接触面は金属であることを特徴とする請求項１記
載の熱電変換素子用熱応力緩和パッド。2. The thermal stress relaxation pad for a thermoelectric conversion element according to claim 1, wherein both contact surfaces of the functionally gradient material on the heat source side and the thermoelectric element side are made of metal.
源側接触面との間の前記組成割合と前記電気絶縁層と熱
電素子側接触面との間の前記組成割合とが同じで前記電
気絶縁層を中心にして対称配置されていることを特徴と
する請求項１または２記載の熱電変換素子用熱応力緩和
パッド。3. The functionally gradient material has the same composition ratio between the electrical insulating layer and the contact surface on the heat source side and the composition ratio between the electrical insulating layer and the contact surface on the thermoelectric element side. The thermal stress relaxation pad for a thermoelectric conversion element according to claim 1 or 2, wherein the thermal stress relaxation pad is symmetrically arranged around the insulating layer.
変換素子用熱応力緩和パッドを熱電素子と高温側熱源及
び低温側熱源との間にそれぞれ設置したことを特徴とす
る熱電変換素子。4. The thermoelectric conversion element according to claim 1, wherein the thermal stress relaxation pad for a thermoelectric conversion element is installed between the thermoelectric element and the high temperature side heat source and the low temperature side heat source, respectively. .
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02942497A JP3482094B2 (en) | 1997-02-13 | 1997-02-13 | Thermal stress relaxation pad for thermoelectric conversion element and thermoelectric conversion element |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP02942497A JP3482094B2 (en) | 1997-02-13 | 1997-02-13 | Thermal stress relaxation pad for thermoelectric conversion element and thermoelectric conversion element |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10229224A JPH10229224A (en) | 1998-08-25 |
| JP3482094B2 true JP3482094B2 (en) | 2003-12-22 |
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ID=12275761
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP02942497A Expired - Lifetime JP3482094B2 (en) | 1997-02-13 | 1997-02-13 | Thermal stress relaxation pad for thermoelectric conversion element and thermoelectric conversion element |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE112005001129T5 (en) | 2004-05-19 | 2008-08-07 | Hitachi Powdered Metals Co., Ltd., Matsudo | Thermoelectric conversion system and method for improving the efficiency of a thermoelectric conversion system |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2004265885A (en) * | 2003-01-09 | 2004-09-24 | Ihi Aerospace Co Ltd | Inclination structure material and functional element employing it |
| US20050002818A1 (en) * | 2003-07-04 | 2005-01-06 | Hitachi Powdered Metals Co., Ltd. | Production method for sintered metal-ceramic layered compact and production method for thermal stress relief pad |
| US20060005873A1 (en) * | 2004-07-06 | 2006-01-12 | Mitsuru Kambe | Thermoelectric conversion module |
| JP4728745B2 (en) * | 2005-08-29 | 2011-07-20 | 株式会社東芝 | Thermoelectric device and thermoelectric module |
| DE102010022668B4 (en) * | 2010-06-04 | 2012-02-02 | O-Flexx Technologies Gmbh | Thermoelectric element and module comprising a plurality of such elements |
-
1997
- 1997-02-13 JP JP02942497A patent/JP3482094B2/en not_active Expired - Lifetime
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE112005001129T5 (en) | 2004-05-19 | 2008-08-07 | Hitachi Powdered Metals Co., Ltd., Matsudo | Thermoelectric conversion system and method for improving the efficiency of a thermoelectric conversion system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH10229224A (en) | 1998-08-25 |
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