JP2016188164A - Oxide sintered compact, and production method therefor - Google Patents

Oxide sintered compact, and production method therefor Download PDF

Info

Publication number
JP2016188164A
JP2016188164A JP2015069912A JP2015069912A JP2016188164A JP 2016188164 A JP2016188164 A JP 2016188164A JP 2015069912 A JP2015069912 A JP 2015069912A JP 2015069912 A JP2015069912 A JP 2015069912A JP 2016188164 A JP2016188164 A JP 2016188164A
Authority
JP
Japan
Prior art keywords
sintered body
atmosphere
temperature
oxide sintered
niobium oxide
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
Application number
JP2015069912A
Other languages
Japanese (ja)
Other versions
JP6492877B2 (en
Inventor
原 浩之
Hiroyuki Hara
浩之 原
謙一 伊藤
Kenichi Ito
謙一 伊藤
原 慎一
Shinichi Hara
慎一 原
健治 尾身
Kenji Onomi
健治 尾身
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Tosoh Corp
Original Assignee
Tosoh Corp
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Tosoh Corp filed Critical Tosoh Corp
Priority to JP2015069912A priority Critical patent/JP6492877B2/en
Publication of JP2016188164A publication Critical patent/JP2016188164A/en
Application granted granted Critical
Publication of JP6492877B2 publication Critical patent/JP6492877B2/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Abstract

PROBLEM TO BE SOLVED: To provide an oxide sintered compact which consists of niobium oxide, has high density, can allow DC to be discharged therefrom and is obtained inexpensively, and to provide a production method of the oxide sintered compact, in which the oxide sintered compact can be obtained easily by using an inexpensive facility without adopting an HP method or an HIP method.SOLUTION: The oxide sintered compact is characterized in that the density thereof is 95% or higher, the bulk resistance thereof is 1,000 Ω-cm or lower, the area of whose target surface is 500 cmor larger and the niobium (IV) oxide belonging to a NbOphase does not exist when measured by an X-ray diffraction method.SELECTED DRAWING: None

Description

本発明は、高屈折率膜などの薄膜形成用スパッタリングターゲットに使用される酸化物焼結体、及びその製造方法に関する。   The present invention relates to an oxide sintered body used for a sputtering target for forming a thin film such as a high refractive index film, and a method for producing the same.

近年、携帯型ディスプレイや建材ガラスにおいて屈折率調整用として高屈折率膜が採用されつつある。しかし、高屈折率材料は酸素欠損のない化学量論組成において電気的に絶縁(10Ω・cm以上)であり、例えば高屈折率材料である酸化ニオブターゲットは、常圧焼結法ではDC放電が可能なターゲットの導電性が得られないため、高温、加圧、非酸化雰囲気条件下で焼結体を還元し、焼結体の導電性を高めるため、ホットプレス(HP)法で製造しなければならなかった(例えば、特許文献1、2参照)。しかしながら、HP法を用いた場合、大型のターゲットの製造においては巨大なプレス機構が必要となり、現実的なプロセスではなく、ターゲットは小型で平板型などの単純形状に限定され、大面積や円筒型などの複雑形状を得ることができなかった。 In recent years, high refractive index films are being used for refractive index adjustment in portable displays and building glass. However, a high refractive index material is electrically insulated (10 4 Ω · cm or more) in a stoichiometric composition without oxygen deficiency. For example, a niobium oxide target, which is a high refractive index material, is a DC in a normal pressure sintering method. Manufactured by hot press (HP) method to reduce the sintered body under high temperature, pressure and non-oxidizing atmosphere conditions and increase the conductivity of the sintered body because the conductivity of the target that can be discharged is not obtained. (For example, refer to Patent Documents 1 and 2). However, when the HP method is used, a large press mechanism is required for manufacturing a large target, and this is not a realistic process. The target is small and limited to a simple shape such as a flat plate type. A complicated shape such as could not be obtained.

このため、特許文献3では、大気雰囲気中で焼成して得られた焼結体を熱間静水圧プレス(HIP)処理することで、焼結体の表面抵抗を下げ、HP法を使用しないため、大面積や複雑形状の焼結体が製造できる提案がなされている。しかし、HIP法は、高圧高温で処理するため高圧容器を含む高価で大掛りな装置が必要であり、多大なコストがかかり経済的ではないだけでなく、非酸化雰囲気の圧力を高め、酸素原子とニオブ原子の結合を弱めて還元するため、必要以上に酸化ニオブ焼結体が還元される問題があった。   For this reason, in patent document 3, the surface resistance of a sintered compact is lowered by carrying out hot isostatic pressing (HIP) processing to the sintered compact obtained by baking in air | atmosphere, and HP method is not used. A proposal has been made that a sintered body having a large area or a complicated shape can be produced. However, the HIP method requires high-priced and large-scale equipment including a high-pressure vessel for processing at high pressure and high temperature, which is not only costly and economical, but also increases the pressure of the non-oxidizing atmosphere, Therefore, there is a problem that the niobium oxide sintered body is reduced more than necessary.

特開2005−256175号公報JP 2005-256175 A 特開2004−059965号公報JP 2004-059965 A 特開2002−338354号公報JP 2002-338354 A

本発明の目的は、酸化ニオブからなる高密度でDC放電可能な酸化物焼結体を安価に提供することであり、HP法やHIP法によらず安価な設備で容易に得ることができる製造方法を提供することである。   An object of the present invention is to provide an oxide sintered body made of niobium oxide capable of high density and DC discharge at low cost, and can be easily obtained with inexpensive equipment regardless of the HP method or the HIP method. Is to provide a method.

本発明者らは、化学量論組成において電気的に絶縁である酸化ニオブ(V)からなる焼結体の導電性と製造プロセスについて鋭意検討を行った結果、常圧焼結法の手法を用いて高密度で導電性のある焼結体を得られることを見出し、本発明を完成するに至った。   As a result of intensive studies on the conductivity and manufacturing process of a sintered body made of niobium oxide (V) that is electrically insulating in the stoichiometric composition, the present inventors have used the atmospheric pressure sintering method. Thus, the inventors have found that a sintered body having high density and conductivity can be obtained, and the present invention has been completed.

すなわち、本発明は
(1)焼結体密度が95%以上であり、バルク抵抗が1000Ω・cm以下であり、ターゲット面の面積が500cm以上であり、X線回折でNbO相に帰属される酸化ニオブ(IV)が存在しないことを特徴とする酸化ニオブ焼結体。
(2)形状が円筒形であることを特徴とする(1)に記載の酸化ニオブ焼結体。
(3)形状が平板形であり、ターゲット面の面積が1000cm以上であることを特徴とする(1)に記載の酸化ニオブ焼結体。
(4)常圧焼結法で酸化ニオブ焼結体を製造する方法であって、昇温時の雰囲気を酸化性雰囲気とし、降温時の雰囲気を非酸化性雰囲気に切り替えることを特徴とする酸化ニオブ焼結体の製造方法。
(5)非酸化性雰囲気に切り替える温度が900℃〜1450℃であることを特徴とする(4)に記載の酸化ニオブ焼結体の製造方法。
に関するものである。
That is, the present invention has (1) a sintered body density of 95% or more, a bulk resistance of 1000 Ω · cm or less, a target surface area of 500 cm 2 or more, and belonging to the NbO 2 phase by X-ray diffraction. Niobium oxide sintered body characterized by the absence of niobium oxide (IV).
(2) The niobium oxide sintered body according to (1), which has a cylindrical shape.
(3) The niobium oxide sintered body according to (1), wherein the shape is a flat plate and the area of the target surface is 1000 cm 2 or more.
(4) A method for producing a niobium oxide sintered body by a normal pressure sintering method, characterized in that the atmosphere at the time of temperature rise is an oxidizing atmosphere and the atmosphere at the time of temperature drop is switched to a non-oxidizing atmosphere. A method for producing a niobium sintered body.
(5) The method for producing a niobium oxide sintered body according to (4), wherein the temperature switched to the non-oxidizing atmosphere is 900 ° C. to 1450 ° C.
It is about.

以下、本発明を詳細に説明する。   Hereinafter, the present invention will be described in detail.

本発明は、酸化ニオブからなる焼結体であって、焼結体密度が95%以上であり、バルク抵抗値が1000Ω・cm以下であり、ターゲット面の面積が500cm以上であり、X線回折でNbO相に帰属される酸化ニオブ(IV)が存在しないことを特徴とする酸化物焼結体である。 The present invention is a sintered body made of niobium oxide, having a sintered body density of 95% or more, a bulk resistance value of 1000 Ω · cm or less, an area of a target surface of 500 cm 2 or more, and an X-ray The oxide sintered body is characterized by the absence of niobium (IV) oxide attributed to the NbO 2 phase by diffraction.

本発明の焼結体密度は、相対密度で95%以上であることを特徴とする。焼結体密度が低いと、スパッタリングターゲットとして用いた場合にアーキング発生の頻度が高くなるため、好ましくは98%以上、より好ましくは99%以上である。   The sintered body density of the present invention is characterized by being a relative density of 95% or more. If the sintered compact density is low, the frequency of arcing increases when used as a sputtering target, so it is preferably 98% or more, more preferably 99% or more.

また、本発明の酸化物焼結体は、スパッタリングターゲットとして使用する場合、安定的にDC放電を行うため、バルク抵抗が1000Ω・cm以下であることが必要であり、250Ω・cm以下であることがより好ましい。   In addition, when the oxide sintered body of the present invention is used as a sputtering target, it needs to have a bulk resistance of 1000 Ω · cm or less and 250 Ω · cm or less in order to stably perform DC discharge. Is more preferable.

本発明の酸化物焼結体中の酸素欠損量は、焼結体の抵抗と相関が高く、バルク抵抗が低いことは、焼結体中の酸素欠損が多く存在することを意味する。酸素欠損が多いターゲットでは、スパッタリング時にスパッタガスとして酸素を多く導入する必要があるため、酸素の導入によって成膜レートが急激に低下するという問題が生じる。このため、バルク抵抗値の下限としては0.05Ω・cmが好ましく、より好ましくは0.5Ωcmで、さらに好ましくは1Ω・cmである。   The amount of oxygen vacancies in the oxide sintered body of the present invention has a high correlation with the resistance of the sintered body, and the low bulk resistance means that there are many oxygen vacancies in the sintered body. In a target having many oxygen vacancies, it is necessary to introduce a large amount of oxygen as a sputtering gas at the time of sputtering, which causes a problem that the film formation rate is rapidly reduced by the introduction of oxygen. For this reason, the lower limit of the bulk resistance value is preferably 0.05 Ω · cm, more preferably 0.5 Ωcm, and even more preferably 1 Ω · cm.

また、本発明の酸化物焼結体は、HP法を使用しないために、そのターゲット面の面積が500cm以上とすることが可能である。ここで言うターゲット面の面積とは、スパッタリングされる側の焼結体表面の面積を言う。なお、複数の焼結体から構成される多分割ターゲットの場合、それぞれの焼結体の中でスパッタリングされる側の焼結体表面の面積が最大のものを多分割ターゲットにおけるターゲット面の面積とする。焼結対の形状は特に制限はなく、平板形状、円筒形状のいずれであっても問題ない。平板形状の焼結体であれば、ターゲット面の面積が1000cm以上のものも製造可能であり、2000cm以上のものも製造可能である。 Further, since the oxide sintered body of the present invention does not use the HP method, the area of the target surface can be 500 cm 2 or more. The area of the target surface here refers to the area of the surface of the sintered body on the side to be sputtered. In the case of a multi-divided target composed of a plurality of sintered bodies, the area of the surface of the sintered body on the side to be sputtered in each sintered body is the largest and the area of the target surface in the multi-divided target To do. There is no restriction | limiting in particular in the shape of a sintering pair, There is no problem even if it is either flat plate shape or cylindrical shape. In the case of a flat plate-shaped sintered body, those having a target surface area of 1000 cm 2 or more can be produced, and those having a surface of 2000 cm 2 or more can be produced.

さらに、本発明の酸化物焼結体の結晶相は、XRDで酸化ニオブ(IV)相が存在しないことを特徴とする。酸化ニオブ(V)(密度4.542g/cm)と酸化ニオブ(IV)(密度5.916g/cm)は密度差が大きく、酸化ニオブ(IV)が生成されると体積変化で焼結体中に内部応力やマイクロクラックが内在し、特に大型の焼結体では割れ易く、歩留りよく焼結体を製造することができない。また、このような焼結体を用いて、スパッタリングで高パワーを投入した場合、放電中に割れが発生し易く、成膜工程の生産性を低下させる原因となるため、好ましくない。 Furthermore, the crystalline phase of the oxide sintered body of the present invention is characterized by the absence of a niobium (IV) oxide phase by XRD. Niobium oxide (V) (density 4.542 g / cm 3 ) and niobium oxide (IV) (density 5.916 g / cm 3 ) have a large density difference. Internal stresses and microcracks are inherent in the body, and particularly large sintered bodies are easily cracked, making it impossible to produce sintered bodies with good yield. In addition, when such a sintered body is used and high power is applied by sputtering, it is not preferable because cracks are likely to occur during discharge and cause the productivity of the film forming process to be reduced.

なお、ターゲットへの投入負荷は、投入電力を平板型ターゲットではエロージョン面積で、円筒型ターゲットではプラズマが発生する面積で割った電力密度(W/cm)で規格化される。通常、平板型ターゲットの生産における一般的な電力密度は1〜5W/cm程度であるが、本発明においては10W/cm以上の高パワー条件においても割れのない、高品質なターゲット材となる酸化物焼結体が得られる。 Note that the input load to the target is normalized by the power density (W / cm 2 ) obtained by dividing the input power by the erosion area for a flat plate target and by the area where plasma is generated for a cylindrical target. Usually, common power density in the production of plate type target is about 1~5W / cm 2, no cracks even 10 W / cm 2 or more high power conditions in the present invention, a high quality target material An oxide sintered body is obtained.

本発明の酸化ニオブ焼結体の製造方法は、酸化ニオブ(V)粉末を成形した後、得られた成形体を酸化性雰囲気で常圧焼結し、焼結体の冷却を非酸化性雰囲気とすることを特徴とする。酸化ニオブ(V)を常圧焼結する場合、非酸化性雰囲気では焼結体が低密度となるため、少なくとも昇温時(室温から焼成温度まで)は酸化性雰囲気とする。一方、降温時(焼成温度から室温まで)は焼結体のバルク抵抗に影響するため、焼結体の冷却は非酸化性雰囲気で行う。酸化ニオブ(V)は通常室温付近において電気的に絶縁の化学量論組成が安定相であるが、高温下では化学量論組成に対して酸素欠損を有する導電相が安定相であると考えられ、冷却にともない雰囲気から酸素が供給され、低温で安定の化学量論組成になると考えられる。すなわち、降温時の雰囲気を酸化性雰囲気から非酸化性雰囲気に切り替えることで、高温安定の導電相が酸化するのを防止し、容易に導電性焼結体を得ることが可能となる。   In the method for producing a niobium oxide sintered body according to the present invention, after the niobium oxide (V) powder is molded, the obtained molded body is subjected to normal pressure sintering in an oxidizing atmosphere, and the sintered body is cooled in a non-oxidizing atmosphere. It is characterized by. When niobium oxide (V) is sintered at normal pressure, the sintered body has a low density in a non-oxidizing atmosphere, and therefore, an oxidizing atmosphere is used at least when the temperature is raised (from room temperature to the firing temperature). On the other hand, since the bulk resistance of the sintered body is affected when the temperature is lowered (from the firing temperature to room temperature), the sintered body is cooled in a non-oxidizing atmosphere. Niobium (V) oxide is usually a stable phase with an electrically insulating stoichiometric composition near room temperature, but a conductive phase having oxygen deficiency with respect to the stoichiometric composition is considered to be a stable phase at high temperatures. It is considered that oxygen is supplied from the atmosphere as it is cooled, resulting in a stable stoichiometric composition at low temperatures. That is, by switching the temperature-falling atmosphere from the oxidizing atmosphere to the non-oxidizing atmosphere, it is possible to prevent the high-temperature stable conductive phase from being oxidized and to easily obtain a conductive sintered body.

本発明の焼成に用いる酸化性雰囲気とは、3%以上の酸素濃度を有する雰囲気であり、コストの面から大気雰囲気が好ましい。また、冷却時に用いる非酸化性雰囲気とは、0.1%以下の酸素濃度を有する雰囲気であって、水素などの還元作用を有する還元雰囲気は含まない。これらの雰囲気は、大気や酸素、及び窒素やアルゴンなどのガスを適宜フローすることで調整することが出来る。   The oxidizing atmosphere used in the firing of the present invention is an atmosphere having an oxygen concentration of 3% or more, and an air atmosphere is preferable from the viewpoint of cost. Further, the non-oxidizing atmosphere used at the time of cooling is an atmosphere having an oxygen concentration of 0.1% or less, and does not include a reducing atmosphere having a reducing action such as hydrogen. These atmospheres can be adjusted by appropriately flowing air, oxygen, or a gas such as nitrogen or argon.

さらに、非酸化性雰囲気に切り替える温度で焼結体のバルク抵抗を調整することが可能である。これは、高温下での酸素欠損量がその温度によって異なり、温度が高いほど酸素欠損量が多いためであると考えられ、処理温度(雰囲気の切替温度)が高いほど焼結体のバルク抵抗は低い値を示す。雰囲気の切り替えを行う場合、確実に行うため切替温度で保持してガス置換を行うことが好ましく、保持する時間は、焼成炉の大きさ、雰囲気を調整するガス流量によって適宜最適な時間を設定する。具体的には、酸素濃度計を用いて焼成の加熱前にガスの置換に必要な時間を確認する等により、保持時間を設定する。   Furthermore, it is possible to adjust the bulk resistance of the sintered body at a temperature that switches to a non-oxidizing atmosphere. This is thought to be because the amount of oxygen vacancies at high temperatures varies depending on the temperature, and the higher the temperature, the more oxygen vacancies. The higher the processing temperature (atmosphere switching temperature), the bulk resistance of the sintered body Indicates a low value. When switching the atmosphere, it is preferable to perform gas replacement while maintaining the switching temperature in order to ensure the switching. The holding time is appropriately set according to the size of the firing furnace and the gas flow rate for adjusting the atmosphere. . Specifically, the holding time is set by, for example, confirming the time required for gas replacement before heating for firing using an oxygen concentration meter.

以下、本発明の酸化物焼結体の製造方法について、工程毎に説明する。   Hereafter, the manufacturing method of the oxide sintered compact of this invention is demonstrated for every process.

(1)原料調整工程
原料粉末は酸化ニオブ(V)粉末を用いる。原料粉末の純度は99.9%以上が好ましく、より好ましくは99.99%以上である。不純物が含まれると、焼成工程における異常粒成長の原因となる。
(1) Raw material adjustment process Niobium oxide (V) powder is used as the raw material powder. The purity of the raw material powder is preferably 99.9% or more, more preferably 99.99% or more. If impurities are included, it causes abnormal grain growth in the firing process.

原料粉末は成形性の改善のため、圧密、粉砕や造粒処理することが好ましい。圧密、粉砕処理としては特に限定されるものではないが、ジルコニア、アルミナ、ナイロン樹脂等のボールやビーズを用いた乾式、湿式のメディア撹拌型ミルや機械撹拌式ミル等の方法が例示される。具体的には、ボールミル、ビーズミル、アトライタ、振動ミル、遊星ミル、ジェットミル、二軸遊星撹拌式混合機等が挙げられる。湿式法のボールミルやビーズミル、アトライタ、振動ミル、遊星ミル、ジェットミル等を用いる場合には、粉砕後のスラリーを乾燥する必要がある。この乾燥方法は特に限定されるものではないが、例えば、濾過乾燥、流動層乾燥、噴霧乾燥等が例示でき、乾燥と同時に造粒することもできる。   The raw material powder is preferably subjected to compaction, pulverization or granulation for improving the moldability. The consolidation and pulverization are not particularly limited, and examples thereof include dry and wet media stirring mills and mechanical stirring mills using balls and beads such as zirconia, alumina, and nylon resin. Specifically, a ball mill, a bead mill, an attritor, a vibration mill, a planetary mill, a jet mill, a biaxial planetary agitation mixer, and the like can be given. When a wet ball mill, bead mill, attritor, vibration mill, planetary mill, jet mill or the like is used, it is necessary to dry the pulverized slurry. Although this drying method is not specifically limited, For example, filtration drying, fluidized-bed drying, spray drying, etc. can be illustrated and it can granulate simultaneously with drying.

最終的に得られる酸化ニオブ(V)粉末としては、BET比表面積が4〜15m/gのものを使用することが好ましい。BET比表面積が4m/g未満であると焼結体密度が上がり難く、15m/gを超えると成形性が悪化し、凝集等により粉末の取り扱いも困難になる。なお、成形性を考慮して、ポリビニルアルコール、アクリル系ポリマー、メチルセルロース、ワックス類、オレイン酸等の成形助剤を原料粉末に添加しても良い。 The niobium oxide (V) powder finally obtained preferably has a BET specific surface area of 4 to 15 m 2 / g. When the BET specific surface area is less than 4 m 2 / g, the density of the sintered body is difficult to increase, and when it exceeds 15 m 2 / g, the formability is deteriorated and the handling of the powder becomes difficult due to aggregation or the like. In consideration of moldability, molding aids such as polyvinyl alcohol, acrylic polymer, methylcellulose, waxes, oleic acid and the like may be added to the raw material powder.

(2)成形工程
成形方法は、原料粉末を目的とした形状に成形できる成形方法を適宜選択することが可能であり、特に限定されるものではない。プレス成形法、鋳込み成形法、射出成形法等が例示できる。
(2) Molding process The molding method is not particularly limited, and a molding method capable of molding the raw material powder into a desired shape can be appropriately selected. Examples thereof include a press molding method, a casting molding method, and an injection molding method.

成形圧力は成形体にクラック等の発生がなく、取り扱いが可能な強度を有する成形体であれば特に限定されるものではないが、成形密度は可能な限り高めた方が好ましい。そのために冷間静水圧プレス(CIP)成形等の方法を用いることも可能である。CIP圧力は充分な圧密効果を得るため1ton/cm以上が好ましく、さらに好ましくは2ton/cm以上、とりわけ好ましくは2〜3ton/cmである。 The molding pressure is not particularly limited as long as it does not cause cracks in the molded body and has a strength that can be handled, but it is preferable to increase the molding density as much as possible. Therefore, it is also possible to use a method such as cold isostatic pressing (CIP) molding. CIP pressure is preferably for 1 ton / cm 2 or more to obtain a sufficient consolidation effect, more preferably 2 ton / cm 2 or more, especially preferably 2~3ton / cm 2.

(3)焼成工程
次に得られた成形体を少なくとも昇温時(室温から焼成温度まで)は酸化性雰囲気で常圧焼結し、焼結体の降温時の雰囲気を非酸化性雰囲気に切り替える。昇温時の酸化性雰囲気は、3%以上の酸素濃度を有する雰囲気であり、降温時に用いる非酸化性雰囲気とは、0.1%以下の酸素濃度を有する雰囲気であって、窒素やアルゴンなどのガスをフローすることで調整することが出来る。酸化性雰囲気から非酸化性雰囲気への切替温度は、目標とする焼結体のバルク抵抗に応じて設定することができるが、DC放電可能なスパッタリングターゲットを得るためには、900℃〜1450℃が好ましい。切替温度での保持時間は焼成炉の大きさや流量によって適宜設定されるが、0.5〜5時間程度で雰囲気の切替を完了するように設計した方が、生産性の面で好ましい。焼成設備としては、電気炉、ガス炉及びマイクロ波炉等が例示できる。焼成温度は1150〜1450℃とすることが好ましい。焼成温度が1150℃未満では高密度化が不十分となるおそれがあり、1450℃を超える温度では焼結体の異常粒成長などが顕著となり、焼結体密度が低下するおそれがある。
(3) Firing step Next, the molded body obtained is sintered at normal pressure in an oxidizing atmosphere at least when the temperature is raised (from room temperature to the firing temperature), and the atmosphere when the sintered body is lowered is switched to a non-oxidizing atmosphere. . The oxidizing atmosphere at the time of temperature increase is an atmosphere having an oxygen concentration of 3% or more, and the non-oxidizing atmosphere used at the time of temperature decrease is an atmosphere having an oxygen concentration of 0.1% or less, such as nitrogen or argon It can be adjusted by flowing the gas. The switching temperature from the oxidizing atmosphere to the non-oxidizing atmosphere can be set in accordance with the target bulk resistance of the sintered body, but in order to obtain a sputtering target capable of DC discharge, 900 ° C. to 1450 ° C. Is preferred. The holding time at the switching temperature is appropriately set according to the size and flow rate of the firing furnace, but it is preferable in terms of productivity to design the switching of the atmosphere in about 0.5 to 5 hours. Examples of the firing equipment include an electric furnace, a gas furnace, and a microwave furnace. The firing temperature is preferably 1150 to 1450 ° C. If the firing temperature is less than 1150 ° C., the densification may be insufficient, and if the firing temperature is higher than 1450 ° C., abnormal grain growth of the sintered body becomes remarkable, and the sintered body density may decrease.

なお、水分やバインダーを含む成形体の場合、特に大型の成形体では水分やバインダー成分が揮発する際に、急激な体積膨張を伴うと成形体が割れることがある。このため、水分やバインダー成分が揮発している温度領域、例えば100〜400℃の温度域においては昇温速度を20〜100℃/時間とすることが好ましい。   In the case of a molded body containing moisture and a binder, when the moisture and binder components are volatilized particularly in a large-sized molded body, the molded body may be cracked when accompanied by rapid volume expansion. For this reason, it is preferable to make a temperature increase rate into 20-100 degreeC / hour in the temperature range in which the water | moisture content and the binder component are volatilizing, for example, the temperature range of 100-400 degreeC.

(4)ターゲット化工程
得られた焼結体は、平面研削盤、円筒研削盤、旋盤、切断機、マシニングセンター等の機械加工機を用いて、板状、円状、円筒状等の所望の形状に研削加工する。さらに、必要に応じて無酸素銅やチタン等からなるバッキングプレート、バッキングチューブにインジウム半田等を用いて接合(ボンディング)することにより、本発明の焼結体をターゲット材としたスパッタリングターゲットを得ることができる。
(4) Targeting process The obtained sintered body is formed into a desired shape such as a plate shape, a circular shape, or a cylindrical shape by using a machining machine such as a surface grinder, a cylindrical grinder, a lathe, a cutting machine, or a machining center. To grind. Furthermore, a sputtering target using the sintered body of the present invention as a target material is obtained by bonding (bonding) a backing plate made of oxygen-free copper, titanium, or the like to the backing tube or backing tube using indium solder or the like as necessary. Can do.

本発明によれば従来から知られた常圧焼結法を利用して焼結体を製造できるため、大型のターゲットを製造することが可能となる。平板型スパッタリングターゲットの場合、ターゲット面の面積1000cm以上の大型の焼結体を作製することができ、さらに複雑な形状である円筒型スパッタリングターゲットも作製することができる。 According to the present invention, since a sintered body can be manufactured using a conventionally known atmospheric pressure sintering method, a large target can be manufactured. In the case of a flat plate-type sputtering target, a large-sized sintered body having a target surface area of 1000 cm 2 or more can be produced, and a cylindrical sputtering target having a more complicated shape can also be produced.

本発明の酸化ニオブ焼結体は高密度でDC放電可能な導電性を有し、大型スパッタリングターゲットに利用することが可能である。   The niobium oxide sintered body of the present invention has a high density and can conduct DC discharge, and can be used for a large sputtering target.

以下、実施例により本発明を更に具体的に説明するが、本発明はこれに限定されるものではない。なお、本実施例における各測定は以下のように行った。
(1)焼結体の密度
焼結体の相対密度は、JIS R 1634に準拠して、アルキメデス法によりかさ密度を測定し、真密度で割って相対密度を求めた。焼結体の真密度は、4.542(g/cm)を用いた。
(2)X線回折試験
鏡面研磨した焼結体試料の2θ=20〜70°の範囲のX線回折パターンを測定した。
走査方法 :ステップスキャン法(FT法)
X線源 :CuKα
パワー :40kV、40mA
ステップ幅:0.01°
(3)抵抗率の測定
焼結体の任意の部分より切り出し、厚み方向に切断した断面の中心で測定した10サンプルの平均値を測定データとした。
試料サイズ:10mm×20mm×1mm
測定方法:4探針法
測定装置:ロレスタHP MCP−T410(三菱油化製)
(4)スパッタリング評価
得られた平板形状の焼結体を101.6mmΦ×6mmt(円筒形状の焼結体は外径148mm×内径136mm×長さ254.1mm)に加工した後、無酸素銅製のバッキングプレート(バッキングチューブ)にインジウムハンダによりボンディングしてスパッタリングターゲットとした。このターゲットを用いて投入パワーを変化させてスパッタリングを行い、DC放電の安定性およびアーキング計測の評価を行なった。
(スパッタリング条件)
ガス :アルゴン+酸素(3%)
圧力 :0.6Pa
電源 :DC
投入パワー:500W(6.2W/cm、14.0W/cm
900W(11.1W/cm
放電時間 :各120min
アーキング計測条件(しきい電圧):スパッタ電圧−50V。
EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto. In addition, each measurement in a present Example was performed as follows.
(1) Density of Sintered Body The relative density of the sintered body was determined by measuring the bulk density by the Archimedes method in accordance with JIS R 1634 and dividing by the true density. The true density of the sintered body was 4.542 (g / cm 3 ).
(2) X-ray diffraction test An X-ray diffraction pattern in the range of 2θ = 20 to 70 ° of the mirror-polished sintered sample was measured.
Scanning method: Step scan method (FT method)
X-ray source: CuKα
Power: 40kV, 40mA
Step width: 0.01 °
(3) Measurement of resistivity The average value of 10 samples measured at the center of the cross section cut out from an arbitrary portion of the sintered body and cut in the thickness direction was used as measurement data.
Sample size: 10 mm x 20 mm x 1 mm
Measuring method: 4-probe method Measuring device: Loresta HP MCP-T410 (Mitsubishi Yuka)
(4) Sputtering evaluation After processing the obtained flat plate-shaped sintered body to 101.6 mmΦ × 6 mmt (cylindrical sintered body is outer diameter 148 mm × inner diameter 136 mm × length 254.1 mm), it is made of oxygen-free copper. A sputtering target was bonded to a backing plate (backing tube) with indium solder. Sputtering was performed using this target while changing the input power, and DC discharge stability and arcing measurement were evaluated.
(Sputtering conditions)
Gas: Argon + oxygen (3%)
Pressure: 0.6Pa
Power supply: DC
Input power: 500 W (6.2 W / cm 2 , 14.0 W / cm 2 )
900W (11.1W / cm 2 )
Discharge time: 120 min each
Arcing measurement conditions (threshold voltage): Sputtering voltage -50V.

(実施例1)
BET比表面積9.74m/gの酸化ニオブ(V)粉末を3ton/cmの圧力で冷間静水圧プレス(CIP)成形を行い、約390mm×770mm×12mmtの成形体を作製した。
Example 1
A niobium (V) oxide powder having a BET specific surface area of 9.74 m 2 / g was subjected to cold isostatic pressing (CIP) molding at a pressure of 3 ton / cm 2 to produce a molded body of about 390 mm × 770 mm × 12 mmt.

次にこの成形体をアルミナセッターの上に設置して、抵抗加熱式電気炉内に設置し、以下の条件で焼成を実施した。焼成は焼成温度にて保持完了後、焼成雰囲気を大気雰囲気から窒素雰囲気に変更するために窒素フローを実施し、炉内を窒素雰囲気にした。
(焼成条件)
昇温速度 :100℃/hr
昇温雰囲気 :大気雰囲気
焼成温度 :1400℃
焼成時間 :3hr
降温速度 :100℃/hr
雰囲気切替温度での保持時間:1hr
降温雰囲気 :窒素雰囲気
焼結体サイズ323mm×637mm×10mmt(2057cm)の割れのない焼結体が得られた。焼結体特性及びスパッタリング評価結果を表1に示す。
Next, this compact was placed on an alumina setter, placed in a resistance heating electric furnace, and fired under the following conditions. Firing was carried out after holding at the firing temperature, and then a nitrogen flow was performed to change the firing atmosphere from an air atmosphere to a nitrogen atmosphere, and the inside of the furnace was changed to a nitrogen atmosphere.
(Baking conditions)
Temperature increase rate: 100 ° C./hr
Temperature rising atmosphere: Air atmosphere Firing temperature: 1400 ° C
Firing time: 3 hr
Temperature drop rate: 100 ° C / hr
Holding time at atmosphere switching temperature: 1 hr
Temperature-decreasing atmosphere: A sintered body having no cracks with a nitrogen atmosphere sintered body size of 323 mm × 637 mm × 10 mmt (2057 cm 2 ) was obtained. The sintered body characteristics and sputtering evaluation results are shown in Table 1.

(実施例2〜5)
焼成条件の雰囲気切り替え温度を変更した以外は、実施例1と同様の方法で焼結体を作製した。焼結体の焼結体特性及びスパッタリング評価の結果を表1に示す。
(Examples 2 to 5)
A sintered body was produced in the same manner as in Example 1 except that the atmosphere switching temperature of the firing conditions was changed. The sintered body characteristics of the sintered body and the results of sputtering evaluation are shown in Table 1.

(実施例6)
成形体サイズを約250×600×12mmtとした以外は、実施例1と同様の方法で焼結体を作製した。焼結体の焼結体特性及びスパッタリング評価の結果を表1に示す。
(Example 6)
A sintered body was produced in the same manner as in Example 1 except that the compact size was about 250 × 600 × 12 mmt. The sintered body characteristics of the sintered body and the results of sputtering evaluation are shown in Table 1.

(実施例7)
成形体サイズを約400×1300×12mmtとした以外は、実施例1と同様の方法で焼結体を作製した。焼結体の焼結体特性及びスパッタリング評価の結果を表1に示す。
(Example 7)
A sintered body was produced in the same manner as in Example 1 except that the compact size was about 400 × 1300 × 12 mmt. The sintered body characteristics of the sintered body and the results of sputtering evaluation are shown in Table 1.

(実施例8)
酸化ニオブ(V)粉末のBET比表面積を4.23m/gとした以外は、実施例1と同様の方法で焼結体を作製した。焼結体の焼結体特性及びスパッタリング評価の結果を表1に示す。
(Example 8)
A sintered body was produced in the same manner as in Example 1 except that the niobium (V) oxide powder had a BET specific surface area of 4.23 m 2 / g. The sintered body characteristics of the sintered body and the results of sputtering evaluation are shown in Table 1.

(実施例9)
成形体サイズを外径180mm×内径157mm×長さ300mmの円筒形状に変更した以外は、実施例1と同様の方法で焼結体を作製した。焼結体の焼結体特性及びスパッタリング評価の結果を表1に示す。
Example 9
A sintered body was produced in the same manner as in Example 1 except that the size of the compact was changed to a cylindrical shape having an outer diameter of 180 mm, an inner diameter of 157 mm, and a length of 300 mm. The sintered body characteristics of the sintered body and the results of sputtering evaluation are shown in Table 1.

(実施例10)
成形体サイズを外径180mm×内径157mm×長さ300mmの円筒形状に変更した以外は、実施例4と同様の方法で焼結体を作製した。焼結体の焼結体特性及びスパッタリング評価の結果を表1に示す。
(Example 10)
A sintered body was produced in the same manner as in Example 4 except that the compact size was changed to a cylindrical shape having an outer diameter of 180 mm, an inner diameter of 157 mm, and a length of 300 mm. The sintered body characteristics of the sintered body and the results of sputtering evaluation are shown in Table 1.

(比較例1)
焼成温度にて保持完了後、焼成雰囲気を大気雰囲気から変更しなかった以外は、実施例1と同様の方法で焼結体を作製した。焼結体の焼結体特性及びスパッタリング評価の結果を表1に示す。
(Comparative Example 1)
After completion of holding at the firing temperature, a sintered body was produced in the same manner as in Example 1 except that the firing atmosphere was not changed from the air atmosphere. The sintered body characteristics of the sintered body and the results of sputtering evaluation are shown in Table 1.

(比較例2)
焼成条件の昇温雰囲気を窒素雰囲気とした以外は、実施例1と同様の方法で焼結体を作製した。焼結体の焼結体特性及びスパッタリング評価の結果を表1に示す。
(Comparative Example 2)
A sintered body was produced in the same manner as in Example 1 except that the temperature rising atmosphere of the firing conditions was a nitrogen atmosphere. The sintered body characteristics of the sintered body and the results of sputtering evaluation are shown in Table 1.

(比較例3)
比較例1と同様の方法で作製した焼結体をアルミナセッターの上に設置して、熱間静水圧プレス(HIP)装置内に設置し、以下の条件でHIP処理を実施した。
(HIP処理条件)
昇温速度 :100℃/hr
昇温雰囲気:アルゴン雰囲気
圧力 :2000気圧
加熱温度 :1200℃
加熱時間 :3hr
降温速度 :100℃/hr
降温雰囲気:アルゴン雰囲気
焼結体サイズ323mm×637mm×10mmt(2057cm)の割れのない焼結体が得られた。焼結体の焼結体特性及びスパッタリング評価結果を表1に示す。
(Comparative Example 3)
A sintered body produced by the same method as in Comparative Example 1 was placed on an alumina setter, placed in a hot isostatic press (HIP) apparatus, and subjected to HIP treatment under the following conditions.
(HIP processing conditions)
Temperature increase rate: 100 ° C./hr
Temperature rising atmosphere: Argon atmosphere Pressure: 2000 atmospheres Heating temperature: 1200 ° C
Heating time: 3 hr
Temperature drop rate: 100 ° C / hr
Temperature-decreasing atmosphere: Argon atmosphere Sintered body A 323 mm × 637 mm × 10 mmt (2057 cm 2 ) non-cracked sintered body was obtained. Table 1 shows the sintered body characteristics and sputtering evaluation results of the sintered body.

(比較例4)
BET比表面積9.74m/gの酸化ニオブ(V)粉末をカーボン製のホットプレス用型(150mm×640mm)に充填し、以下の条件で焼成した。このときのホットプレス圧力は50kg/cmとした。
(焼成条件)
昇温速度 :100℃/hr
昇温雰囲気:真空
焼成温度 :1400℃
焼成時間 :3hr
降温速度 :100℃/hr
降温雰囲気:真空
型と同等のサイズの焼結体が得られたが、割れが生じていた。焼結体の焼結体特性を表1に示す。
(Comparative Example 4)
Niobium oxide (V) powder having a BET specific surface area of 9.74 m 2 / g was filled in a carbon hot press mold (150 mm × 640 mm) and fired under the following conditions. The hot press pressure at this time was 50 kg / cm 2 .
(Baking conditions)
Temperature increase rate: 100 ° C./hr
Temperature rising atmosphere: Vacuum Firing temperature: 1400 ° C
Firing time: 3 hr
Temperature drop rate: 100 ° C / hr
Temperature-decreasing atmosphere: A sintered body having the same size as that of the vacuum mold was obtained, but cracking occurred. Table 1 shows the sintered body characteristics of the sintered body.

Figure 2016188164
Figure 2016188164

Claims (5)

焼結体密度が95%以上であり、バルク抵抗が1000Ω・cm以下であり、ターゲット面の面積が500cm以上であり、X線回折でNbO相に帰属される酸化ニオブ(IV)が存在しないことを特徴とする酸化ニオブ焼結体。 The sintered body density is 95% or more, the bulk resistance is 1000 Ω · cm or less, the target surface area is 500 cm 2 or more, and there exists niobium (IV) oxide attributed to the NbO 2 phase by X-ray diffraction. A niobium oxide sintered body characterized by not. 形状が円筒形であることを特徴とする請求項1に記載の酸化ニオブ焼結体。 The niobium oxide sintered body according to claim 1, wherein the sintered body is cylindrical. 形状が平板形であり、ターゲット面の面積が1000cm以上であることを特徴とする請求項1に記載の酸化ニオブ焼結体。 The niobium oxide sintered body according to claim 1, wherein the niobium oxide sintered body has a flat plate shape and an area of a target surface of 1000 cm 2 or more. 常圧焼結法で酸化ニオブ焼結体を製造する方法であって、昇温時の雰囲気を酸化性雰囲気とし、降温時の雰囲気を非酸化性雰囲気に切り替えることを特徴とする酸化ニオブ焼結体の製造方法。 A method for producing a niobium oxide sintered body by a normal pressure sintering method, characterized in that the atmosphere at the time of temperature rise is an oxidizing atmosphere and the atmosphere at the time of temperature fall is switched to a non-oxidizing atmosphere. Body manufacturing method. 非酸化性雰囲気に切り替える温度が900℃〜1450℃であることを特徴とする請求項4に記載の酸化ニオブ焼結体の製造方法。 5. The method for producing a niobium oxide sintered body according to claim 4, wherein the temperature switched to the non-oxidizing atmosphere is 900 ° C. to 1450 ° C. 5.
JP2015069912A 2015-03-30 2015-03-30 Oxide sintered body and manufacturing method thereof Active JP6492877B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2015069912A JP6492877B2 (en) 2015-03-30 2015-03-30 Oxide sintered body and manufacturing method thereof

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2015069912A JP6492877B2 (en) 2015-03-30 2015-03-30 Oxide sintered body and manufacturing method thereof

Publications (2)

Publication Number Publication Date
JP2016188164A true JP2016188164A (en) 2016-11-04
JP6492877B2 JP6492877B2 (en) 2019-04-03

Family

ID=57240336

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2015069912A Active JP6492877B2 (en) 2015-03-30 2015-03-30 Oxide sintered body and manufacturing method thereof

Country Status (1)

Country Link
JP (1) JP6492877B2 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017142063A1 (en) * 2016-02-18 2017-08-24 東ソー株式会社 Oxide sintered body and production method for same

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02302397A (en) * 1989-05-17 1990-12-14 Murata Mfg Co Ltd Production of oriented crystal film
JPH0885866A (en) * 1994-09-16 1996-04-02 Sumitomo Metal Mining Co Ltd Production of ito sintered compact
JP2002338354A (en) * 2001-05-18 2002-11-27 Kyocera Corp Niobium oxide sintered compact, its manufacturing method and sputtering target using the same
JP2004059965A (en) * 2002-07-25 2004-02-26 Toshiba Corp Sputtering target and method for manufacturing the same
JP2005133105A (en) * 2003-10-28 2005-05-26 Sumitomo Metal Mining Co Ltd Sputtering target for depositing film having high refractive index, and its production method
JP2005256175A (en) * 2005-04-27 2005-09-22 Asahi Glass Ceramics Co Ltd Target and method of producing high refractive index film by the target
JP2012127005A (en) * 2010-11-08 2012-07-05 Mitsui Mining & Smelting Co Ltd Split sputtering target and method for producing the same
CN102659405A (en) * 2012-04-06 2012-09-12 西北稀有金属材料研究院 Preparation method of high-density niobium oxide sputtering target material
US20130126800A1 (en) * 2011-11-17 2013-05-23 Monika Backhaus-Ricoult Niobium oxide-based thermoelectric composites
WO2014077198A1 (en) * 2012-11-13 2014-05-22 Jx日鉱日石金属株式会社 NbO2 SINTERED BODY, SPUTTERING TARGET COMPRISING SINTERED BODY AND METHOD OF PRODUCING NbO2 SINTERED BODY
WO2014132872A1 (en) * 2013-02-26 2014-09-04 三菱マテリアル株式会社 Niobium oxide sputtering target, production method therefor, and niobium oxide film

Patent Citations (12)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02302397A (en) * 1989-05-17 1990-12-14 Murata Mfg Co Ltd Production of oriented crystal film
JPH0885866A (en) * 1994-09-16 1996-04-02 Sumitomo Metal Mining Co Ltd Production of ito sintered compact
JP2002338354A (en) * 2001-05-18 2002-11-27 Kyocera Corp Niobium oxide sintered compact, its manufacturing method and sputtering target using the same
JP2004059965A (en) * 2002-07-25 2004-02-26 Toshiba Corp Sputtering target and method for manufacturing the same
JP2005133105A (en) * 2003-10-28 2005-05-26 Sumitomo Metal Mining Co Ltd Sputtering target for depositing film having high refractive index, and its production method
JP2005256175A (en) * 2005-04-27 2005-09-22 Asahi Glass Ceramics Co Ltd Target and method of producing high refractive index film by the target
JP2012127005A (en) * 2010-11-08 2012-07-05 Mitsui Mining & Smelting Co Ltd Split sputtering target and method for producing the same
US20130126800A1 (en) * 2011-11-17 2013-05-23 Monika Backhaus-Ricoult Niobium oxide-based thermoelectric composites
CN102659405A (en) * 2012-04-06 2012-09-12 西北稀有金属材料研究院 Preparation method of high-density niobium oxide sputtering target material
WO2014077198A1 (en) * 2012-11-13 2014-05-22 Jx日鉱日石金属株式会社 NbO2 SINTERED BODY, SPUTTERING TARGET COMPRISING SINTERED BODY AND METHOD OF PRODUCING NbO2 SINTERED BODY
WO2014132872A1 (en) * 2013-02-26 2014-09-04 三菱マテリアル株式会社 Niobium oxide sputtering target, production method therefor, and niobium oxide film
JP2014194072A (en) * 2013-02-26 2014-10-09 Mitsubishi Materials Corp Niobium oxide sputtering target, production method thereof and niobium oxide film

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2017142063A1 (en) * 2016-02-18 2017-08-24 東ソー株式会社 Oxide sintered body and production method for same

Also Published As

Publication number Publication date
JP6492877B2 (en) 2019-04-03

Similar Documents

Publication Publication Date Title
JP5205696B2 (en) Gallium oxide based sintered body and method for producing the same
JP6264846B2 (en) Oxide sintered body, sputtering target and manufacturing method thereof
JP5158355B2 (en) Sputtering target made of sintered oxide
JP5969786B2 (en) LiCoO2 sintered body, sputtering target, and manufacturing method thereof
JP5904056B2 (en) IGZO sintered body, manufacturing method thereof, and sputtering target
KR20180093140A (en) Ito sputtering target and method for manufacturing same, ito transparent electroconductive film, and method for manufacturing ito transparent electroconductive film
JP6492877B2 (en) Oxide sintered body and manufacturing method thereof
JP6582698B2 (en) Oxide sintered body and sputtering target
JP5998712B2 (en) IGZO sintered body, sputtering target, and oxide film
JP5218032B2 (en) Method for producing sintered body for transparent conductive film
JP2013129545A (en) Igzo sintered body, method of manufacturing the same, and sputtering target
KR102375637B1 (en) Oxide sintered compact and sputtering target
KR102404834B1 (en) Oxide sintered compact, method for producing same, and sputtering target
KR102649404B1 (en) Oxide sintered body, its manufacturing method and sputtering target
JP6705202B2 (en) Oxide sintered body and manufacturing method thereof
JP4835542B2 (en) Method for producing conductive ceramic sintered body
KR102620041B1 (en) Oxide sintered body, manufacturing method thereof, and sputtering target material
JP4835541B2 (en) Manufacturing method of sintered ceramics
JP5685810B2 (en) Raw material powder for sintered body for transparent conductive film
JP2010150611A (en) Sintered compact for transparent conductive film, sputtering target, and method for producing the sintered compact for transparent conductive film
JP2017014551A (en) Sputtering target
JP2022159633A (en) Igzo sintered body, manufacturing method thereof, and sputtering target
JP2006076853A (en) Method of manufacturing aluminum nitride substrate

Legal Events

Date Code Title Description
A621 Written request for application examination

Free format text: JAPANESE INTERMEDIATE CODE: A621

Effective date: 20180219

A977 Report on retrieval

Free format text: JAPANESE INTERMEDIATE CODE: A971007

Effective date: 20180905

A131 Notification of reasons for refusal

Free format text: JAPANESE INTERMEDIATE CODE: A131

Effective date: 20180918

A521 Request for written amendment filed

Free format text: JAPANESE INTERMEDIATE CODE: A523

Effective date: 20181114

TRDD Decision of grant or rejection written
A01 Written decision to grant a patent or to grant a registration (utility model)

Free format text: JAPANESE INTERMEDIATE CODE: A01

Effective date: 20190205

A61 First payment of annual fees (during grant procedure)

Free format text: JAPANESE INTERMEDIATE CODE: A61

Effective date: 20190218

R151 Written notification of patent or utility model registration

Ref document number: 6492877

Country of ref document: JP

Free format text: JAPANESE INTERMEDIATE CODE: R151