JPH06172012A - Microwave heater - Google Patents
Microwave heaterInfo
- Publication number
- JPH06172012A JPH06172012A JP4349748A JP34974892A JPH06172012A JP H06172012 A JPH06172012 A JP H06172012A JP 4349748 A JP4349748 A JP 4349748A JP 34974892 A JP34974892 A JP 34974892A JP H06172012 A JPH06172012 A JP H06172012A
- Authority
- JP
- Japan
- Prior art keywords
- sintered
- microwave
- cavity resonator
- dielectric loss
- heating
- 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.)
- Granted
Links
- 238000010438 heat treatment Methods 0.000 claims abstract description 66
- 239000006096 absorbing agent Substances 0.000 claims abstract description 60
- 238000005245 sintering Methods 0.000 claims abstract description 19
- 239000012212 insulator Substances 0.000 claims description 24
- 239000000463 material Substances 0.000 abstract description 26
- 239000000919 ceramic Substances 0.000 abstract description 6
- 230000008878 coupling Effects 0.000 abstract description 4
- 238000010168 coupling process Methods 0.000 abstract description 4
- 238000005859 coupling reaction Methods 0.000 abstract description 4
- 229910052451 lead zirconate titanate Inorganic materials 0.000 description 17
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 16
- 229910010271 silicon carbide Inorganic materials 0.000 description 15
- 230000005684 electric field Effects 0.000 description 12
- 229910004298 SiO 2 Inorganic materials 0.000 description 9
- 230000000694 effects Effects 0.000 description 8
- 239000007789 gas Substances 0.000 description 7
- 239000000843 powder Substances 0.000 description 6
- 229910018072 Al 2 O 3 Inorganic materials 0.000 description 5
- 239000010453 quartz Substances 0.000 description 5
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 4
- 238000000921 elemental analysis Methods 0.000 description 3
- 238000000034 method Methods 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 229910002113 barium titanate Inorganic materials 0.000 description 2
- JRPBQTZRNDNNOP-UHFFFAOYSA-N barium titanate Chemical compound [Ba+2].[Ba+2].[O-][Ti]([O-])([O-])[O-] JRPBQTZRNDNNOP-UHFFFAOYSA-N 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 208000037584 hereditary sensory and autonomic neuropathy Diseases 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 230000005672 electromagnetic field Effects 0.000 description 1
- 238000004453 electron probe microanalysis Methods 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 239000011810 insulating material Substances 0.000 description 1
- 230000001678 irradiating effect Effects 0.000 description 1
- HFGPZNIAWCZYJU-UHFFFAOYSA-N lead zirconate titanate Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Ti+4].[Zr+4].[Pb+2] HFGPZNIAWCZYJU-UHFFFAOYSA-N 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 229910052575 non-oxide ceramic Inorganic materials 0.000 description 1
- 239000011225 non-oxide ceramic Substances 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 229910052574 oxide ceramic Inorganic materials 0.000 description 1
- 239000011224 oxide ceramic Substances 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000010287 polarization Effects 0.000 description 1
- 238000005498 polishing Methods 0.000 description 1
- 230000001737 promoting effect Effects 0.000 description 1
- 229910052594 sapphire Inorganic materials 0.000 description 1
- 239000010980 sapphire Substances 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
Landscapes
- Compositions Of Oxide Ceramics (AREA)
Abstract
(57)【要約】
【目的】 誘電損率の温度依存性が大きく熱伝導率が小
さな材料、例えば、ＰＺＴセラミックス等をマイクロ波
によって加熱むらなく加熱でき、均一に焼結することが
可能な装置を提供する。
【構成】 マイクロ波を発生させるマイクロ波発生手段
１と、被焼結体６を加熱・焼結するための空胴共振器２
と、前記マイクロ波発生手段から空胴共振器にマイクロ
波を伝送する導波管３と、該導波管から前記空胴共振器
にマイクロ波を導入し該空胴共振器内の共振を維持する
結合窓４と、被焼結体の少なくとも一部を覆うように配
置され、誘電損率が大きくて、マイクロ波を吸収し易
く、かつ前記被焼結体よりも誘電損率の温度依存性が小
さなマイクロ波吸収体７と、前記被焼結体とマイクロ波
吸収体の少なくとも一部を覆うように配置され、誘電損
率が小さくマイクロ波を透過し易い低損失体８とからな
る。
(57) [Abstract] [Purpose] A device capable of heating a material having a large temperature dependence of the dielectric loss factor and a small thermal conductivity, for example, PZT ceramics, by heating with microwaves without unevenness, and capable of uniformly sintering. I will provide a. [Structure] Microwave generating means 1 for generating a microwave, and cavity resonator 2 for heating and sintering a sintered body 6.
A waveguide 3 for transmitting microwaves from the microwave generation means to the cavity resonator, and microwaves introduced from the waveguide to the cavity resonator to maintain resonance in the cavity resonator. Which is arranged so as to cover at least a part of the body to be sintered and the coupling window 4 which has a large dielectric loss factor, easily absorbs microwaves, and the temperature dependence of the dielectric loss factor is higher than that of the body to be sintered. The microwave absorber 7 has a small size, and the low-loss body 8 is arranged so as to cover at least a part of the body to be sintered and the microwave absorber, and has a low dielectric loss factor and easily transmits microwaves.
Description
【０００１】[0001]
【産業上の利用分野】誘電損率（＝εr ・ｔａｎδ：ε
r は誘電率、ｔａｎδは誘電正接）の温度依存性が大き
く熱伝導率が小さな材料、例えば、チタン酸ジルコン酸
鉛（ＰＺＴ）セラミックス等をマイクロ波によって加熱
むらなく加熱でき、均一に焼結することが可能な装置に
関する。[Industrial application] Dielectric loss factor (= ε r · tan δ: ε
(r is a dielectric constant, tan δ is a dielectric loss tangent), and a material having a large temperature dependence and a small thermal conductivity, for example, lead zirconate titanate (PZT) ceramics can be heated by a microwave without uneven heating and uniformly sintered. It relates to a device capable.
【０００２】[0002]
【従来の技術】誘電損率の温度依存性が大きく熱伝導率
が小さな材料、例えば、ＰＺＴセラミックス等をマイク
ロ波によって加熱すると、被焼結体内に誘電損率の違い
によって、温度分布が著しく不均一になる現象、いわゆ
るランナウエイ現象が生じ、被焼結体に加熱むらが生じ
るため、均一な加熱または焼結するのが困難であった。
本発明者等は、上記問題点を解決する方法として、被焼
結体よりも誘電損率の温度依存性が小さく、かつ熱伝導
率が大きな性質を有するＳｉＣ等のマイクロ波吸収体を
介してＰＺＴ等の被焼結体にマイクロ波を照射すると被
焼結体の誘電損率の急激な変化を防ぐことができ、加熱
むらを防止できることを確かめた（特開平２−３２９８
０号）。この方法によって加熱むらを防止できるのは、
マイクロ波吸収体でマイクロ波のエネルギーの一部が吸
収されるため、被焼結体の誘電損率の急激な変化が緩和
され、かつマイクロ波吸収体と被焼結体との接触部から
被焼結体への熱伝導およびマイクロ波吸収体から被焼結
体への輻射熱により被焼結体に温度の不均一な部分がな
くなり、被焼結体を均一に加熱できるからである。2. Description of the Related Art When a material having a large temperature dependence of the dielectric loss factor and a small thermal conductivity, such as PZT ceramics, is heated by microwaves, the temperature distribution becomes remarkably unsatisfactory due to the difference in the dielectric loss factor in the sintered body. Since a phenomenon of becoming uniform, a so-called runaway phenomenon occurs and heating unevenness occurs in the sintered body, it is difficult to perform uniform heating or sintering.
As a method for solving the above-mentioned problems, the inventors of the present invention have used a microwave absorber such as SiC having a property that the temperature dependence of the dielectric loss factor is smaller than that of the sintered body and the thermal conductivity is larger than that of the sintered body. It has been confirmed that when a sintered body such as PZT is irradiated with microwaves, it is possible to prevent a rapid change in the dielectric loss factor of the sintered body and prevent uneven heating (Japanese Patent Application Laid-Open No. 2-3298).
No. 0). This method can prevent uneven heating,
Since a part of microwave energy is absorbed by the microwave absorber, abrupt changes in the dielectric loss factor of the body to be sintered are mitigated and the microwave absorber and the body to be sintered are contacted with each other. This is because the heat transfer to the sintered body and the radiant heat from the microwave absorber to the sintered body eliminates the nonuniform temperature portion of the sintered body, and the sintered body can be heated uniformly.
【０００３】しかし、１１００℃以上の高温になると、
加熱むらが生じることがあった。特に、周波数として
２．４５ＧＨｚという比較的小さな周波数を用いた場合
に加熱むらが大きくなった。また、１１００℃以上の高
温において、マイクロ波吸収体と被焼結体の材質によっ
ては、マイクロ波吸収体と被焼結体が反応して、それら
の境界面に誘電損率の大きな化合物層が形成され、被焼
結体内に急激な温度分布が生じ、被焼結体に加熱むらが
生じたり、あるいはマイクロ波吸収体と被焼結体が反応
して被焼結体内にマイクロ波吸収体の元素の一部が拡散
し、被焼結体が不均一な組織となり、特性が劣化すると
いう問題があった。However, when the temperature becomes higher than 1100 ° C.,
Heating unevenness may occur. In particular, heating unevenness increased when a relatively small frequency of 2.45 GHz was used. Further, at a high temperature of 1100 ° C. or higher, depending on the materials of the microwave absorber and the body to be sintered, the microwave absorber and the body to be sintered react with each other, and a compound layer having a large dielectric loss factor is formed on the boundary surface between them. Formed, a rapid temperature distribution occurs in the body to be sintered, heating unevenness occurs in the body to be sintered, or the microwave absorber and the body to be reacted react with each other. There is a problem that part of the element diffuses, the sintered body has a non-uniform structure, and the characteristics deteriorate.
【０００４】[0004]
【発明が解決しょうとする課題】本発明の目的は、誘電
損率の温度依存性が大きく、熱伝導率が小さなセラミッ
クスを１１００℃以上の高温において確実に加熱むらを
なくし、均一に焼結する装置を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to reliably sinter ceramics having a large temperature dependence of the dielectric loss factor and a small thermal conductivity at a high temperature of 1100 ° C. or more to uniformly sinter them. To provide a device.
【０００５】[0005]
（第１発明の構成）本第１発明のマイクロ波加熱装置
（請求項１記載の発明）は、マイクロ波を発生させるマ
イクロ波発生手段と、被焼結体を加熱・焼結するための
空胴共振器と、前記マイクロ波発生手段から空胴共振器
にマイクロ波を伝送する導波管と、該導波管から前記空
胴共振器にマイクロ波を導入し該空胴共振器内の共振を
維持する結合器とからなり、該空胴共振器内に配置した
被焼結体にマイクロ波を照射して被焼結体を焼結するた
めのマイクロ波加熱装置であって、被焼結体の少なくと
も一部を覆うように配置され、誘電損率が大きくて、マ
イクロ波を吸収し易く、かつ前記被焼結体よりも誘電損
率の温度依存性が小さなマイクロ波吸収体と、前記被焼
結体とマイクロ波吸収体の一部を覆って配置され、誘電
損率が小さくマイクロ波を透過し易い低損失体と、を有
することを特徴とする。(Structure of First Invention) A microwave heating apparatus of the first invention (an invention according to claim 1) is a microwave generating means for generating a microwave, and a space for heating / sintering an object to be sintered. A cavity resonator, a waveguide for transmitting microwaves from the microwave generation means to the cavity resonator, and a resonance in the cavity resonator for introducing microwaves from the waveguide into the cavity resonator. A microwave heating device for irradiating a sintered body disposed in the cavity resonator with microwaves to sinter the sintered body, A microwave absorber that is arranged to cover at least a part of the body, has a large dielectric loss factor, is easy to absorb microwaves, and has a temperature dependence of the dielectric loss factor that is smaller than that of the sintered body; Microphone with a small dielectric loss factor that is placed so as to cover the sintered body and part of the microwave absorber. It characterized by having a a likely low loss material through the waves.
【０００６】（第２発明の構成）本第２発明のマイクロ
波加熱装置（請求項２記載の発明）は、前記第１発明の
マイクロ波加熱装置において、被焼結体とマイクロ波吸
収体との間に、被焼結体およびマイクロ波吸収体と反応
し難い絶縁体を配置したことを特徴とする。(Structure of Second Invention) The microwave heating apparatus of the second invention (the invention according to claim 2) is the same as the microwave heating apparatus of the first invention, except that a sintered body and a microwave absorber are provided. An insulating material which is difficult to react with the material to be sintered and the microwave absorber is arranged between the two.
【０００７】[0007]
（第１発明の作用）本第１発明のマイクロ波加熱装置に
おいて、被焼結体およびマイクロ波吸収体の少なくとも
一部を低損失体で覆うことにより１１００℃以上の高温
において被焼結体の加熱むらを防止できる理由は以下の
通りであると推定される。すなわち、被焼結体とマイク
ロ波吸収体を低損失体で覆わない場合は、被焼結体の位
置で電界強度が最大となっている。しかし、被焼結体等
を低損失体で覆うことにより、低損失体内中心部である
被焼結体の位置における電界強度が低下し、ほぼ均一に
なるものと考えられる。そのため、被焼結体に電界が集
中するのを防止でき、被焼結体内部の電界強度がほぼ均
一となり温度分布の不均一が生じ難くなって加熱むらを
防止できるものと思われる。また、低損失体で覆うこと
により、被焼結体と空胴共振器内壁とに生じる放電を防
止することができ、安定した加熱を行うことができる。(Operation of the first invention) In the microwave heating apparatus of the first invention, by covering at least a part of the body to be sintered and the microwave absorber with a low loss body, the body to be sintered is heated at a high temperature of 1100 ° C or higher. The reason why uneven heating can be prevented is presumed to be as follows. That is, when the sintered body and the microwave absorber are not covered with the low-loss body, the electric field strength is maximum at the position of the sintered body. However, it is considered that by covering the sintered body or the like with a low-loss body, the electric field strength at the position of the sintered body, which is the central portion of the low-loss body, decreases and becomes substantially uniform. Therefore, it is considered that the electric field can be prevented from concentrating on the body to be sintered, the electric field strength inside the body to be sintered is substantially uniform, and the uneven temperature distribution is less likely to occur to prevent uneven heating. In addition, by covering with a low-loss body, it is possible to prevent discharge that occurs between the body to be sintered and the inner wall of the cavity resonator, and it is possible to perform stable heating.
【０００８】また、低損失体を用いない場合は、周波数
の低い方がマイクロ波の浸透深さが深いため、マイクロ
波吸収体である炭化珪素（ＳｉＣ）の前記した加熱むら
を防止する効果が小さく、例えば、６ＧＨｚよりも２．
４５ＧＨｚの方がＳｉＣを用いても高温で加熱むらが生
じやすい。しかし、被焼結体等を低損失体で覆う効果は
周波数に無関係であるため、低損失体による低損失体内
中心部の電界強度の均一化効果により、周波数が低い
２．４５ＧＨｚを用いても高温で加熱むらが生じない。Further, when the low loss body is not used, the lower the frequency, the deeper the penetration depth of the microwaves, and therefore the effect of preventing the above-mentioned heating unevenness of the silicon carbide (SiC) which is the microwave absorber is obtained. Smaller than, for example, 6 GHz, 2.
Even if SiC is used at 45 GHz, heating unevenness is likely to occur at high temperatures. However, since the effect of covering the sintered body with the low-loss body is independent of the frequency, even if the frequency is low at 2.45 GHz, the low-loss body makes the electric field strength uniform in the center of the low-loss body. No uneven heating occurs at high temperatures.
【０００９】（第２発明の作用）本第２発明のマイクロ
波加熱装置において、被焼結体とマイクロ波吸収体との
間に、被焼結体およびマイクロ波吸収体と反応し難い絶
縁体を設置すると、被焼結体の加熱むらを防止しつつ被
焼結体とマイクロ波吸収体との反応を防止できるが、そ
の理由は、以下の通りであると推定される。被焼結体と
マイクロ波吸収体との間に絶縁体を設置したので被焼結
体とマイクロ波吸収体とが非接触の状態になり被焼結体
とマイクロ波吸収体との反応を防止できる。また、絶縁
体として被焼結体およびマイクロ波吸収体と反応し難い
材料を用いるので、被焼結体およびマイクロ波吸収体と
絶縁体との反応も起こらない。さらに、絶縁体は、誘電
損率が小さいので絶縁体自体は加熱されず、絶縁体には
温度分布がほとんど生じない。そのため、絶縁体からの
被焼結体への熱影響はほとんどなく前記マイクロ波吸収
体および低損失体によって加熱むらを防止できる。(Operation of the Second Invention) In the microwave heating apparatus of the second invention, an insulator which is difficult to react with the sintered body and the microwave absorber is provided between the sintered body and the microwave absorber. By installing, the reaction between the sintered body and the microwave absorber can be prevented while preventing uneven heating of the sintered body, and the reason is presumed to be as follows. Since the insulator is installed between the sintered body and the microwave absorber, the sintered body and the microwave absorber are in non-contact with each other and the reaction between the sintered body and the microwave absorber is prevented. it can. Moreover, since a material that does not easily react with the sintered body and the microwave absorber is used as the insulator, the reaction between the sintered body and the microwave absorber does not occur. Furthermore, since the insulator has a small dielectric loss factor, the insulator itself is not heated, and the temperature distribution in the insulator hardly occurs. Therefore, there is almost no thermal influence from the insulator on the sintered body, and the microwave absorber and the low loss body can prevent uneven heating.
【００１０】[0010]
（第１発明の効果）本第１発明のマイクロ波加熱装置に
よれば、ＰＺＴのように誘電損率の温度依存性が大き
く、熱伝導率が低い材料でも１１００℃以上の高温にお
いて、しかも周波数として２．４５ＧＨｚといった比較
的低い周波数を用いた場合にも確実に加熱むらをなくす
ることができ、均一に焼結することができる。(Effect of the first invention) According to the microwave heating apparatus of the first invention, even a material having a large temperature dependence of the dielectric loss factor such as PZT and having a low thermal conductivity can be used at a high temperature of 1100 ° C or more and at a high frequency. Even when a relatively low frequency such as 2.45 GHz is used, heating unevenness can be reliably eliminated, and uniform sintering can be performed.
【００１１】（第２発明の効果）本第２発明のマイクロ
波加熱装置によれば、被焼結体の加熱むらを防止しつつ
被焼結体とマイクロ波吸収体との反応を防止できる(Effect of Second Invention) According to the microwave heating apparatus of the second invention, it is possible to prevent the reaction between the sintered body and the microwave absorber while preventing uneven heating of the sintered body.
【００１２】[0012]
（第１発明の具体例）本具体例のマイクロ波加熱装置に
おいて、マイクロ波を発生させるマイクロ波発生手段、
被焼結体を加熱・焼結するための空胴共振器、前記マイ
クロ波発生手段から空胴共振器にマイクロ波を伝送する
導波管および該導波管から前記空胴共振器にマイクロ波
を導入し該空胴共振器内の共振を維持する結合器は、通
常マイクロ波を発生させ、被焼結体を加熱・焼結するの
に用いられるマイクロ波加熱装置で使用されている構成
であれば、特に限定はない。代表的な装置の例を図１に
示す。この装置は、マイクロ波を発生させるマイクロ波
発生手段１、被焼結体を加熱・焼結するための空胴共振
器２、前記マイクロ波発生手段１から空胴共振器２にマ
イクロ波を伝送する導波管３および該導波管３から前記
空胴共振器２にマイクロ波を導入し該空胴共振器内の共
振を維持する結合器４と、該空胴共振器内に配置された
石英等からなる管状の低損失体８と、該容器内に配置さ
れた被焼結体６を支持する石英製の支持棒５と、該支持
棒５の下端に設けられ、該支持棒を回転するためのモー
タ１０からなる。前記被焼結体には、その上下面を覆う
ようにマイクロ波吸収体７が設けられる。前記容器８に
は酸素等のガスを導入するためのガス導入口１２とガス
を排出するためのガス排出口１３を有する。(Embodiment of the first invention) In the microwave heating apparatus of the present embodiment, microwave generation means for generating microwaves,
Cavity resonator for heating / sintering a body to be sintered, waveguide for transmitting microwaves from the microwave generating means to the cavity resonator, and microwave from the waveguide to the cavity resonator In order to maintain the resonance in the cavity resonator, the coupler is usually used to generate microwaves to heat and sinter the object to be sintered. If so, there is no particular limitation. An example of a typical device is shown in FIG. This apparatus includes a microwave generation means 1 for generating a microwave, a cavity resonator 2 for heating and sintering a body to be sintered, and a microwave transmitted from the microwave generation means 1 to the cavity resonator 2. And a coupler 4 for introducing microwaves from the waveguide 3 into the cavity resonator 2 to maintain resonance in the cavity resonator, and a coupler 4 disposed in the cavity resonator. A tubular low-loss body 8 made of quartz or the like, a support rod 5 made of quartz for supporting the sintered body 6 arranged in the container, and a support rod provided at the lower end of the support rod 5 for rotating the support rod. It comprises a motor 10 for The microwave absorber 7 is provided on the sintered body so as to cover the upper and lower surfaces thereof. The container 8 has a gas inlet 12 for introducing a gas such as oxygen and a gas outlet 13 for discharging the gas.
【００１３】本装置で焼結することができる被焼結体と
は、通常のマイクロ波加熱によって焼結すると加熱むら
を生じ易い、すなわち誘電損率の温度依存性が大きく、
熱伝導率が小さい材料をいい、具体的には誘電損率の温
度依存性が常温から８００℃の範囲で１桁以上のセラミ
ックスおよび／または熱伝導率が０．１ｃａｌ／ｃｍ・
ｓｅｃ・℃以下のセラミックスをいう。このような材料
として、例えば、ＰＺＴ、チタン酸バリウム（ＢａＴｉ
Ｏ3 ）、ＰＬＺＴ等の強誘電体材料がある。The object to be sintered that can be sintered with this apparatus is likely to cause uneven heating when sintered by ordinary microwave heating, that is, the temperature dependence of the dielectric loss factor is large.
A material with low thermal conductivity, specifically ceramics whose temperature dependence of dielectric loss factor is one digit or more in the range of room temperature to 800 ° C and / or thermal conductivity of 0.1 cal / cm
It refers to ceramics of sec. Examples of such materials include PZT and barium titanate (BaTi).
There are ferroelectric materials such as O 3 ) and PLZT.
【００１４】次に、マイクロ波吸収体とは、誘電損率が
大きくてマイクロ波の吸収が良く、誘電損率の温度依存
性が被焼結体より小さい材料からなるものである。ま
ず、マイクロ波を充分に吸収するためには、被焼結体の
種類にもよるが、マイクロ波帯（０．３〜３０ＧＨｚ）
における室温での誘電損率が、０．１より大きいことが
望ましい。誘電損率を前記範囲にすると、被焼結体にラ
ンナウエイ現象が生じる前の約８００℃以下の低温域で
マイクロ波吸収体が主として加熱され、被焼結体の温度
分布がより均一となる。また、誘電損率の温度依存性が
被焼結体より小さいことが望ましく、もし温度依存性が
被焼結体より大きいと、マイクロ波吸収体にランナウエ
イ現象が生じ被焼結体の加熱むらを助長するおそれがあ
る。Next, the microwave absorber is made of a material having a large dielectric loss factor, good microwave absorption, and a temperature dependency of the dielectric loss factor smaller than that of the sintered body. First, in order to sufficiently absorb the microwave, depending on the type of the material to be sintered, the microwave band (0.3 to 30 GHz)
It is desirable that the dielectric loss factor at room temperature is higher than 0.1. When the dielectric loss factor is within the above range, the microwave absorber is mainly heated in a low temperature range of about 800 ° C. or lower before the runaway phenomenon occurs in the sintered body, and the temperature distribution of the sintered body becomes more uniform. Further, it is desirable that the temperature dependence of the dielectric loss factor is smaller than that of the body to be sintered. If the temperature dependence is larger than that of the body to be sintered, a runaway phenomenon occurs in the microwave absorber, which causes uneven heating of the body to be sintered. There is a risk of promoting it.
【００１５】また、マイクロ波吸収体は、熱伝導率が、
０．１ｃａｌ／ｃｍ・ｓｅｃ・℃以上であることが望ま
しい。熱伝導率がこれより小さいと、マイクロ波吸収体
に温度分布が生じ、発生した熱が被焼結体に伝導して被
焼結体の温度分布の不均一性を助長するおそれがある。
このような材料として、ＳｉＣ、ＺｎＯ、Ｃ（炭素）、
ＡｌＮ、Ｂ4 Ｃ等がある。The microwave absorber has a thermal conductivity of
It is preferably 0.1 cal / cm · sec · ° C. or higher. If the thermal conductivity is smaller than this, a temperature distribution is generated in the microwave absorber, and the generated heat may be conducted to the sintered body to promote non-uniformity of the temperature distribution of the sintered body.
As such materials, SiC, ZnO, C (carbon),
Examples include AlN and B 4 C.
【００１６】また、このマイクロ波吸収体は、被焼結体
の少なくとも一部を覆うように配置するが、被焼結体と
は接触していても、非接触な状態でもよい。結果とし
て、被焼結体の加熱むらが防止されるように配置されて
いればよい。該マイクロ波吸収体の形状に限定はない
が、通常は、板状で用い、その厚さは、０．５〜１０ｍ
ｍが望ましい。０，５ｍｍ未満だとマイクロ波の吸収効
果が小さくなる。逆に、１０ｍｍを越えるとマイクロ波
の大部分が該マイクロ波吸収体に吸収され、エネルギー
効率が悪くなるとともに、空胴共振器の電界が乱れて共
振がとれにくくなる。また、該マイクロ波吸収体は、被
焼結体の焼結後の大きさと同等かそれより大きいことが
望ましい。小さいとマイクロ波吸収体に覆われていない
部分に温度分布が生じ、被焼結体に加熱むらが生じるこ
とがあるため好ましくない。The microwave absorber is arranged so as to cover at least a part of the body to be sintered, but it may be in contact with or not in contact with the body to be sintered. As a result, it may be arranged so as to prevent uneven heating of the body to be sintered. Although the shape of the microwave absorber is not limited, it is usually used in a plate shape and has a thickness of 0.5 to 10 m.
m is desirable. If it is less than 0.5 mm, the microwave absorption effect is reduced. On the other hand, if it exceeds 10 mm, most of the microwave is absorbed by the microwave absorber, the energy efficiency is deteriorated, and the electric field of the cavity resonator is disturbed to make it difficult to achieve resonance. Further, it is desirable that the microwave absorber has a size equal to or larger than the size of the sintered body after sintering. If it is small, a temperature distribution is generated in a portion not covered with the microwave absorber, and uneven heating may occur in the sintered body, which is not preferable.
【００１７】次に、低損失体は、誘電損率が極めて小さ
く、マイクロ波を吸収し易い材料からなるものをいう。
誘電損率は室温において、０．０１以下が望ましく、こ
れより大きいと、低損失体自体がマイクロ波を吸収して
加熱されるおそれがあり、また低損失体を空胴共振器内
に配置したときに空胴共振器内の電界が乱れて共振がと
れにくくなるとともに低損失体内の電界強度が不均一と
なって、被焼結体に加熱むらが生じることになる。また
低損失体の誘電損率の温度依存性は極めて小さなことが
望まれる。誘電損率の温度依存性が大きいと、被焼結体
が加熱されたときに、輻射熱で低損失体の温度が上昇
し、この加熱された状態でマイクロ波が照射されると、
低損失体自体に加熱低損失体自体に加熱むらが生じる恐
れがあるので好ましくない。Next, the low-loss body is made of a material having a very small dielectric loss factor and easily absorbing microwaves.
The dielectric loss factor is preferably 0.01 or less at room temperature, and if it is larger than this, the low-loss body itself may absorb microwaves and be heated, and the low-loss body is arranged in the cavity resonator. At times, the electric field in the cavity resonator is disturbed to make it difficult to obtain resonance, and the electric field strength in the low-loss body becomes nonuniform, resulting in uneven heating of the body to be sintered. Further, it is desirable that the temperature dependence of the dielectric loss factor of the low loss body is extremely small. When the temperature dependence of the dielectric loss factor is large, when the body to be sintered is heated, the temperature of the low loss body rises due to radiant heat, and when microwaves are radiated in this heated state,
Heating the low loss body itself may cause uneven heating, which is not preferable.
【００１８】このような低損失体の材料としては、Ｓｉ
Ｏ2 、サフアイアまたは純度９９％以上の高純度アルミ
ナ等がある。低損失体は、マイクロ波吸収体および被焼
結体と非接触で、それらの少なくとも一部を覆うように
配置する。覆いかたには特に限定はなく、低損失体で覆
われた内部の電界強度が均一となるように配置されてい
ればよい。形状については、特に限定はなく、例えば、
管状あるいは断面が四角形や楕円の中空体が望ましく、
通常は管を用い、その中心部に被焼結体を配置する。As a material for such a low-loss body, Si is used.
Examples include O 2 , sapphire, and high-purity alumina having a purity of 99% or more. The low-loss body is arranged so as to cover at least a part of the microwave absorber and the body to be sintered without contacting them. The covering method is not particularly limited as long as it is arranged so that the electric field strength inside the low loss body is uniform. The shape is not particularly limited, for example,
Tubular or hollow body with square or elliptical cross section is desirable,
Usually, a tube is used, and the body to be sintered is placed in the center thereof.
【００１９】（第２発明の具体例）本具体例のマイクロ
波加熱装置において、絶縁体とは室温での抵抗率が１０
14Ω・ｃｍ以上を有する、いわゆる絶縁体であること、
ならびに被焼結体およびマイクロ波吸収体と反応しにく
い材料でなければならない。また、誘電損率が室温で
０．０５以下であることが望ましい。誘電損率がこれよ
り大きいと絶縁体も加熱されて絶縁体内に温度分布が生
じて、熱伝導により被焼結体が不均一に加熱されること
になり被焼結体に加熱むらが生じるおそれがある。かか
る材料として被焼結体が酸化物系セラミックスの場合
は、Ａｌ2 Ｏ3 、ＭｇＯ、Ｙ2 Ｏ3 を、また、被焼結体
が非酸化物系セラミックスの場合はＢＮ等を用いること
が望ましい。また、形状は特に限定はないが、通常板状
で用いるのが望ましい。この絶縁体の厚さは５ｍｍ以下
が望ましい。５ｍｍより厚いと、マイクロ波吸収体と被
焼結体との間隔が開きすぎることになり、マイクロ波吸
収体の効果が小さくなるので好ましくない。また、該絶
縁体は、被焼結体とマイクロ波吸収体の間に接触して配
置する。(Specific Example of Second Invention) In the microwave heating apparatus of this specific example, the insulator has a resistivity of 10 at room temperature.
A so-called insulator having a resistance of 14 Ω · cm or more,
In addition, it must be a material that does not easily react with the material to be sintered and the microwave absorber. Further, it is desirable that the dielectric loss factor is 0.05 or less at room temperature. If the dielectric loss ratio is higher than this, the insulator will also be heated and a temperature distribution will occur in the insulator, resulting in uneven heating of the sintered body due to heat conduction, which may cause uneven heating of the sintered body. There is. As such a material, Al 2 O 3 , MgO, Y 2 O 3 may be used when the object to be sintered is an oxide ceramic, and BN or the like may be used when the object to be sintered is a non-oxide ceramic. desirable. The shape is not particularly limited, but it is usually desirable to use a plate shape. The thickness of this insulator is preferably 5 mm or less. If it is thicker than 5 mm, the gap between the microwave absorber and the body to be sintered is too wide, and the effect of the microwave absorber is reduced, which is not preferable. In addition, the insulator is placed in contact between the body to be sintered and the microwave absorber.
【００２０】（実施例１）被焼結体としてＰＺＴ圧粉
体、マイクロ波吸収体としてＳｉＣ板、低損失体として
ＳｉＯ2 管を用い、マイクロ波を照射してセラミック焼
結体を製造し、該焼結体の特性評価を行った。本実施例
において用いたマイクロ波加熱装置を模式的に図１に示
す。この装置は、マイクロ波を発生させるマイクロ波発
生手段１、被焼結体を加熱・焼結するための直方体形の
空胴共振器２、前記マイクロ波発生手段１から空胴共振
器２にマイクロ波を伝送する導波管３および該導波管３
から前記空胴共振器２にマイクロ波を導入し該空胴共振
器内の共振を維持する結合窓４イクロ波を導入し該空胴
共振器内の共振を維持する結合窓４と、該空胴共振器内
に配置された石英からなる管状の低損失体８と、該容器
内に配置された被焼結体６を支持する石英製の支持棒５
と、該支持棒５の下端に設けられ、該支持棒を回転する
ためのモータ１０からなる。前記被焼結体の上下面はマ
イクロ波吸収体であるＳｉＣで挟持されている。また、
前記低損失体８には酸素ガスを導入するためのガス導入
口とガスを排出するためのガス排出口が設置される(Example 1) A PZT green compact was used as a material to be sintered, a SiC plate was used as a microwave absorber, and a SiO 2 tube was used as a low-loss material. The characteristics of the sintered body were evaluated. The microwave heating apparatus used in this example is schematically shown in FIG. This apparatus comprises a microwave generating means 1 for generating a microwave, a rectangular parallelepiped cavity resonator 2 for heating and sintering a body to be sintered, and a microwave from the microwave generating means 1 to a cavity resonator 2. Waveguide 3 for transmitting waves and the waveguide 3
A coupling window 4 for introducing microwaves into the cavity resonator 2 to maintain resonance in the cavity resonator, and a coupling window 4 for introducing microwaves to maintain resonance in the cavity resonator; A tubular low-loss body 8 made of quartz, which is arranged in the body resonator, and a support rod 5 made of quartz, which supports the sintered body 6 arranged in the container.
And a motor 10 provided at the lower end of the support rod 5 for rotating the support rod. The upper and lower surfaces of the body to be sintered are sandwiched by SiC which is a microwave absorber. Also,
The low-loss body 8 is provided with a gas inlet for introducing oxygen gas and a gas outlet for discharging gas.
【００２１】まず、被焼結体であるＰＺＴ粉末をＣＩＰ
処理し、径２０ｍｍ、厚さ３ｍｍのＰＺＴ圧粉体試料を
得た。マイクロ波吸収体には径２０ｍｍ、厚さ３ｍｍの
ＳｉＣ板を用いた。このＳｉＣの誘電損率は１．３、熱
伝導率は０．３ｃａｌ／ｃｍ・ｓｅｃ・℃である。ま
た、低損失体には内径２５ｍｍ、厚さ２ｍｍのＳｉＯ2
管を用いた。このＳｉＯ2 の誘電損率は０．００１以下
である。First, the PZT powder which is the object to be sintered is CIP
This was processed to obtain a PZT green compact sample having a diameter of 20 mm and a thickness of 3 mm. A SiC plate having a diameter of 20 mm and a thickness of 3 mm was used as the microwave absorber. This SiC has a dielectric loss factor of 1.3 and a thermal conductivity of 0.3 cal / cm · sec · ° C. In addition, the low-loss body is made of SiO 2 with an inner diameter of 25 mm and a thickness of 2 mm.
A tube was used. The dielectric loss factor of this SiO 2 is 0.001 or less.
【００２２】次に、前記ＰＺＴ試料をＳｉＣ板で挟み、
これを石英製の支持棒５で空胴共振器内の電界の最大部
位に配置した。さらに、空胴共振器壁面に設置した試料
挿入穴９から低損失体であるＳｉＯ2 管を挿入して試料
およびＳｉＣを覆った。空胴共振器には、単一の空胴共
振器を用い、共振周波数を２．４５ＧＨz 、空胴共振器
内の電磁界モードをＴＥ103 とし、焼結雰囲気は酸素気
流（２ｌ／ｍｉｎ）中とした。なお、被焼結体は、支持
棒を介して、電動機１０により回転させ、被焼結体内の
電界が一様になるようにした。Next, the PZT sample was sandwiched between SiC plates,
The support rod 5 made of quartz was placed at the maximum electric field site in the cavity resonator. Furthermore, a low-loss SiO 2 tube was inserted through the sample insertion hole 9 provided on the wall surface of the cavity resonator to cover the sample and SiC. A single cavity resonator is used as the cavity resonator, the resonance frequency is 2.45 GHz, the electromagnetic field mode in the cavity resonator is TE 103 , and the sintering atmosphere is an oxygen stream (2 l / min). And The body to be sintered was rotated by the electric motor 10 via the support rod so that the electric field in the body to be sintered was uniform.
【００２３】次に、被焼結体を加熱し、焼結を行った。
本装置により、加熱むらを生じることなく１２００℃以
上まで加熱することができ、１１５０℃、１ｍｉｎの焼
結条件で焼結体密度８．１ｇ／ｃｍ3 とほぼ真密度の焼
結体が得られた。また、破面観察の結果、均質な焼結体
であることがわかった。Next, the body to be sintered was heated and sintered.
With this device, it is possible to heat up to 1200 ° C. or higher without causing uneven heating, and a sintered body having a sintered body density of 8.1 g / cm 3 and a true density can be obtained under the sintering conditions of 1150 ° C. and 1 min. It was Further, as a result of observing the fracture surface, it was found that the sintered body was homogeneous.
【００２４】なお、比較のためにＳｉＯ2 管からなる低
損失体を用いない他は、本実施例１と同様の被焼結体、
マイクロ波吸収体およびマイクロ波加熱装置を用いて加
熱処理を行った。その結果、１１５０℃までのマイクロ
波加熱によって、試料中心部が溶融して不均一な組織と
なり真密度近くまで焼結することができなかった。これ
は、低損失体であるＳｉＯ2 管を用いていないため試料
に温度分布ができて加熱むらが生じ、ＰＺＴ試料の中心
が局部的に加熱されたためと推定される。For comparison, a sintered body similar to that of Example 1 except that a low loss body made of a SiO 2 tube was not used,
Heat treatment was performed using a microwave absorber and a microwave heating device. As a result, the microwave heating up to 1150 ° C. melted the central part of the sample to form a non-uniform structure, which made it impossible to sinter to near the true density. It is presumed that this is because the sample had a temperature distribution because of not using the SiO 2 tube which is a low loss body, and uneven heating occurred, and the center of the PZT sample was locally heated.
【００２５】また、低損失体を用いない場合、被焼結体
（ＰＺＴ試料）やマイクロ波吸収体（ＳｉＣ板）の一部
で放電が発生することがあり、一度放電が発生すると加
熱が不安定になって、それ以上焼結を続けることが困難
であった。しかし、被焼結体およびマイクロ波吸収体を
低損失体で覆うことにより、放電を確実に防ぐことがで
き、安定した焼結を行うことができた。If a low-loss body is not used, discharge may occur in a part of the sintered body (PZT sample) or microwave absorber (SiC plate), and once the discharge occurs, heating will be unsuccessful. It became stable and it was difficult to continue sintering any more. However, by covering the material to be sintered and the microwave absorber with a low-loss material, it was possible to reliably prevent electric discharge and perform stable sintering.
【００２６】（実施例２）被焼結体としてＰＺＴ圧粉
体、マイクロ波吸収体としてＳｉＣ板、低損失体として
ＳｉＯ2 管を、それぞれ実施例１と同じ寸法、材質のも
のを用い、被焼結体とマイクロ波吸収体の間に絶縁体を
配置して、実施例１と同じマイクロ波加熱装置、マイク
ロ波加熱条件で加熱し、焼結に及ぼす絶縁体の影響を調
べた。(Embodiment 2) A PZT green compact was used as a material to be sintered, a SiC plate was used as a microwave absorber, and a SiO 2 tube was used as a low-loss material. An insulator was placed between the sintered body and the microwave absorber, heated under the same microwave heating device and microwave heating conditions as in Example 1, and the effect of the insulator on the sintering was examined.
【００２７】図２に示すように、ＣＩＰ処理したＰＺＴ
圧粉体試料の上下面に径２０ｍｍ、厚さ１ｍｍの絶縁体
であるＡｌ2 Ｏ3 板を配置し、さらに該両Ａｌ2 Ｏ3 板
上にマイクロ波吸収体であるＳｉＣ板を配置した。この
ように構成したＰＺＴ試料等からなる積層体全体を支持
棒先端の試料台上に載置し、これらを低損失体であるＳ
ｉＯ2 管で覆い、空胴共振器内の電界の最大部位に挿入
した。なお、絶縁体に用いたＡｌ2 Ｏ3 の誘電損率は
０．０１である。As shown in FIG. 2, CZ-processed PZT
An Al 2 O 3 plate which is an insulator having a diameter of 20 mm and a thickness of 1 mm is arranged on the upper and lower surfaces of the powder compact sample, and a SiC plate which is a microwave absorber is arranged on both of the Al 2 O 3 plates. The entire laminated body composed of the PZT sample or the like configured as described above is placed on the sample table at the tip of the support rod, and these are low-loss S.
It was covered with an iO 2 tube and inserted at the maximum site of the electric field in the cavity resonator. The dielectric loss factor of Al 2 O 3 used for the insulator is 0.01.
【００２８】次に、被焼結体を加熱し、焼結を行った。
本装置により、加熱むらを生じることなく１２００℃以
上まで加熱することができ、１１５０℃、５ｍｉｎの焼
結で密度８．１ｇ／ｃｍ3 とほぼ真密度の焼結体が得ら
れた。また、破面観察の結果、均質な焼結体であること
が明らかとなった。また、ＥＰＭＡ分析により焼結体の
厚さ方向の元素分析を行ったところ、絶縁体からの元素
の拡散はなく、均質な組成の焼結体であることがわかっ
た。また、この焼結体を径１５ｍｍ、厚さ０．５ｍｍに
研摩後、１２０℃のシリコンオイル中で３ｋｖ/minの分
極処理を行い、圧電特性を調べた。その結果、電気機械
結合係数Ｋｐが０．６５という高い値を示し、該焼結体
が優れた圧電特性を有することが明らかになった。Next, the body to be sintered was heated and sintered.
With this apparatus, it was possible to heat up to 1200 ° C. or higher without causing uneven heating, and a sintered body having a density of 8.1 g / cm 3 and a true density was obtained by sintering at 1150 ° C. for 5 minutes. In addition, as a result of observing the fracture surface, it became clear that it was a homogeneous sintered body. Further, elemental analysis in the thickness direction of the sintered body was performed by EPMA analysis, and it was found that the sintered body had a homogeneous composition without diffusion of elements from the insulator. Further, after polishing this sintered body to a diameter of 15 mm and a thickness of 0.5 mm, polarization treatment of 3 kv / min was performed in silicon oil at 120 ° C. to examine the piezoelectric characteristics. As a result, the electromechanical coupling coefficient Kp showed a high value of 0.65, which revealed that the sintered body had excellent piezoelectric characteristics.
【００２９】なお、比較のためにＡｌ2 Ｏ3 からなる絶
縁体を用いない他は、本実施例２と同様のＰＺＴ圧粉体
試料等およびマイクロ波加熱装置を用いて加熱処理を行
った。その結果、１１５０℃、５min の焼結で、実施例
１に比べ焼結時間が長いため被焼結体であるＰＺＴ試料
とマイクロ波吸収体であるＳｉＣとが反応し、試料表面
の中心部分が変質していた。また、試料表面の厚さ方向
の元素分析を行ったところ、吸収体からＳｉが拡散して
いることがわかった。この比較例の試料の圧電特性はＫ
ｐ＝０．３と著しく低かった。For comparison, heat treatment was performed using the same PZT powder compact sample and microwave heating device as in Example 2 except that the insulator made of Al 2 O 3 was not used. As a result, at 1150 ° C. for 5 minutes, the sintering time is longer than in Example 1, so that the PZT sample as the sintered body reacts with SiC as the microwave absorber, and the central portion of the sample surface is It was altered. In addition, elemental analysis in the thickness direction of the sample surface revealed that Si was diffused from the absorber. The piezoelectric characteristic of the sample of this comparative example is K
It was remarkably low at p = 0.3.
【００３０】（実施例３）被焼結体としてＰＬＺＴ圧粉
体、マイクロ波吸収体にＳｉＣ板、低損失体にＳｉＯ2
管、絶縁体にＭｇＯ板を用い、実施例２と同様の装置を
用いてマイクロ波加熱し、得られた焼結体の性能評価を
行った。以下、実施例２との相違点を中心に説明する。
被焼結体としてＰＬＺＴ粉末を用い、該ＰＬＺＴ粉末に
対しＣＩＰ処理を施して径１６ｍｍ、厚さ２ｍｍのＰＬ
ＺＴ圧粉体試料を用意した。また、絶縁体には径１５ｍ
ｍ、厚さ２ｍｍのＭｇＯの円板を用いた。さらに、マイ
クロ波吸収体としては径１５ｍｍ、厚さ４ｍｍのＳｉＣ
板を用い、全体をＳｉＯ2 管で覆った。焼結雰囲気は大
気中とし、被焼結体の加熱処理を行った結果、加熱むら
や放電が発生することなく１１５０℃以上に加熱するこ
とができ、１１５０℃、５ｍｉｎの焼結条件で密度７．
８ｇ／ｃｍ3 とほぼ真密度の焼結体が得られた。得られ
た焼結体について破面観察および元素分析を行った結
果、絶縁体からの元素の拡散もなく、また、均質な組織
の焼結体であることが明らかになった。(Embodiment 3) PLZT powder compact as a sintered body, SiC plate as a microwave absorber, and SiO 2 as a low loss body.
A MgO plate was used for the tube and the insulator, microwave heating was performed using the same apparatus as in Example 2, and the performance of the obtained sintered body was evaluated. Hereinafter, differences from the second embodiment will be mainly described.
PLZT powder was used as a material to be sintered, and the PLZT powder was subjected to CIP treatment to obtain PL having a diameter of 16 mm and a thickness of 2 mm.
A ZT green compact sample was prepared. Also, the insulator has a diameter of 15 m.
A disc of MgO having a thickness of m and a thickness of 2 mm was used. Furthermore, as a microwave absorber, SiC with a diameter of 15 mm and a thickness of 4 mm
A plate was used and the whole was covered with a SiO 2 tube. As a result of performing the heat treatment on the object to be sintered, the sintering atmosphere was in the air, and as a result, it could be heated to 1150 ° C. or higher without uneven heating or discharge, and the density of 7 at 1150 ° C. for 5 minutes. ．
A sintered body having a true density of 8 g / cm 3 was obtained. As a result of fracture surface observation and elemental analysis of the obtained sintered body, it was revealed that the sintered body had a homogeneous structure without diffusion of elements from the insulator.
【図１】実施例１に係るマイクロ波加熱装置の概略図で
ある。FIG. 1 is a schematic diagram of a microwave heating apparatus according to a first embodiment.
【図２】実施例２に係るマイクロ波加熱装置の一部分の
概略図である。FIG. 2 is a schematic view of a part of the microwave heating apparatus according to the second embodiment.
１ マイクロ波発生手段 ２ 空胴共振器 ３ 導波管 ４ 結合器 ６ 被焼結体 ７ マイクロ波吸収体 ８ 低損失体 １１ 絶縁体 DESCRIPTION OF SYMBOLS 1 Microwave generating means 2 Cavity resonator 3 Waveguide 4 Coupler 6 Sintered body 7 Microwave absorber 8 Low loss body 11 Insulator
Claims (2)
手段と、被焼結体を加熱・焼結するための空胴共振器
と、前記マイクロ波発生手段から空胴共振器にマイクロ
波を伝送する導波管と、該導波管から前記空胴共振器に
マイクロ波を導入し該空胴共振器内の共振を維持する結
合器と、前記空胴共振器内に配置された被焼結体支持手
段と、該被焼結体支持手段に支持された被焼結体の少な
くとも一部を覆うように配置され、誘電損率が大きくて
マイクロ波を吸収し易く、かつ被焼結体よりも誘電損率
の温度依存性が小さなマイクロ波吸収体と、前記被焼結
体とマイクロ波吸収体の少なくとも一部を覆うように配
置され、誘電損率が小さくマイクロ波を透過し易い低損
失体と、からなることを特徴とする被焼結体にマイクロ
波を照射して被焼結体を焼結するためのマイクロ波加熱
装置。1. A microwave generation means for generating a microwave, a cavity resonator for heating and sintering a body to be sintered, and a microwave transmitted from the microwave generation means to the cavity resonator. A waveguide, a coupler for introducing microwaves from the waveguide into the cavity resonator to maintain resonance in the cavity resonator, and a sintered body disposed in the cavity resonator. The support means is disposed so as to cover at least a part of the body to be sintered supported by the body to be sintered, has a large dielectric loss factor and easily absorbs microwaves, and is more than the body to be sintered. A microwave absorber having a small temperature dependence of the dielectric loss factor, and a low-loss body arranged so as to cover at least a part of the sintered body and the microwave absorber and having a small dielectric loss factor and easily transmitting microwaves. The object to be sintered is characterized by comprising: Microwave heating device for sintering.
あって、被焼結体とマイクロ波吸収体との間に、被焼結
体およびマイクロ波吸収体と反応し難い絶縁体を配置し
たことを特徴とするマイクロ波加熱装置。2. The microwave heating apparatus according to claim 1, wherein an insulator that is difficult to react with the sintered body and the microwave absorber is arranged between the sintered body and the microwave absorber. The microwave heating device characterized in that
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34974892A JP3233300B2 (en) | 1992-12-01 | 1992-12-01 | Microwave sintering method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34974892A JP3233300B2 (en) | 1992-12-01 | 1992-12-01 | Microwave sintering method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH06172012A true JPH06172012A (en) | 1994-06-21 |
| JP3233300B2 JP3233300B2 (en) | 2001-11-26 |
Family
ID=18405836
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34974892A Expired - Fee Related JP3233300B2 (en) | 1992-12-01 | 1992-12-01 | Microwave sintering method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3233300B2 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100390880B1 (en) * | 2000-12-30 | 2003-07-10 | 엘지마이크론 주식회사 | Cavity of heat treatment apparatus |
| US6891140B2 (en) | 2000-10-19 | 2005-05-10 | Gifu Prefecture | Sintering furnace, method of manufacturing sintered objects, and sintered objects |
| JP2010029666A (en) * | 2008-07-29 | 2010-02-12 | Ivoclar Vivadent Ag | Apparatus for heating of molding, in particular dental-ceramic moldings and the like |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5925937B2 (en) | 2015-04-24 | 2016-05-25 | 富士フイルム株式会社 | Radiation irradiation start determination device, operation method thereof, and radiation irradiation start determination system |
-
1992
- 1992-12-01 JP JP34974892A patent/JP3233300B2/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6891140B2 (en) | 2000-10-19 | 2005-05-10 | Gifu Prefecture | Sintering furnace, method of manufacturing sintered objects, and sintered objects |
| KR100390880B1 (en) * | 2000-12-30 | 2003-07-10 | 엘지마이크론 주식회사 | Cavity of heat treatment apparatus |
| JP2010029666A (en) * | 2008-07-29 | 2010-02-12 | Ivoclar Vivadent Ag | Apparatus for heating of molding, in particular dental-ceramic moldings and the like |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3233300B2 (en) | 2001-11-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| EP1333012B1 (en) | Burning furnace, burnt body producing method, and burnt body | |
| US6090733A (en) | Sintered silicon carbide and method for producing the same | |
| EP0500252B1 (en) | Method and apparatus for processing ceramics | |
| JP2928605B2 (en) | Ceramic sintering method | |
| JP2628104B2 (en) | Method for heat-treating ceramics decomposed and / or oxidized by heat treatment in oxygen-containing gas by microwave heating and susceptor used therefor | |
| KR101006634B1 (en) | Semiconductor or liquid crystal manufacturing device | |
| JPH06172012A (en) | Microwave heater | |
| JP3845777B2 (en) | Firing furnace and method for producing fired body | |
| EP1480259A1 (en) | Heating device for manufacturing semiconductor | |
| JP2001007189A (en) | Electrostatic chuck and its manufacture | |
| JP2533679B2 (en) | Plate-shaped ceramic heater and method for manufacturing the same | |
| Metaxas et al. | Microwave processing of ceramics | |
| JP4216037B2 (en) | Electromagnetic wave heating device, heating sheath used in electromagnetic wave heating device, and method for producing ceramics using them | |
| JP2000130951A (en) | Substrate firing furnace for plasma display panel and furnace member therefor | |
| JP2004168575A (en) | Ceramic sintering method | |
| Derling et al. | Microwave sintering of BaTiO3-based ceramics | |
| JPH06291049A (en) | Thin-film forming device | |
| JP2004205164A (en) | Non-oxide ceramic sintering kiln and method of manufacturing non-oxide ceramic sintered body | |
| JP4526734B2 (en) | Heater element, heating device and substrate heating device | |
| JP3419992B2 (en) | Ceramic members | |
| JP4450473B2 (en) | Cleaning container | |
| JPH10279366A (en) | Manufacturing method of high strength piezoelectric ceramics | |
| JPH06345540A (en) | Method for sintering ceramic | |
| JPH1045472A (en) | High frequency dielectric ceramics and method of manufacturing the same | |
| KR20200068778A (en) | High-capacity ceramic heater for electric vehicle and manufacturing method thereof |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| TRDD | Decision of grant or rejection written | ||
| R151 | Written notification of patent or utility model registration |
Ref document number: 3233300 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R151 |
|
| R250 | Receipt of annual fees |
Free format text: JAPANESE INTERMEDIATE CODE: R250 |
|
| LAPS | Cancellation because of no payment of annual fees |