JP2000034466A - Plasma-resistant sealing material - Google Patents
Plasma-resistant sealing materialInfo
- Publication number
- JP2000034466A JP2000034466A JP10202021A JP20202198A JP2000034466A JP 2000034466 A JP2000034466 A JP 2000034466A JP 10202021 A JP10202021 A JP 10202021A JP 20202198 A JP20202198 A JP 20202198A JP 2000034466 A JP2000034466 A JP 2000034466A
- Authority
- JP
- Japan
- Prior art keywords
- silica
- barium sulfate
- sealing material
- plasma
- fluororubber
- 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
Landscapes
- Sealing Material Composition (AREA)
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、配管・装置等の広
範囲な分野で使用される静的および動的シールを担当す
るゴム系シール材のうち、特に半導体デバイス等を製造
する場合に使用するプラズマを発生させる機器に用いる
フッ素ゴム系シール材の改良に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is used for manufacturing a semiconductor device and the like among rubber-based sealing materials for static and dynamic sealing used in a wide range of fields such as piping and equipment. The present invention relates to an improvement in a fluororubber-based sealing material used for a device that generates plasma.
【０００２】[0002]
【従来の技術】ゴムＯリングのように、合成ゴムを主材
料とし、これに加硫剤・可塑剤・カーボンブラック等の
ゴム薬品を配合し、金型によって加圧加熱成型したゴム
系シール材は、柔らかく、接合面（フランジ表面等）と
のなじみが良くシール性が優れているために、各種産業
の装置・機器に幅広く使用されている。このうち、半導
体産業においては、エッチング等の工程における薬液ラ
インのシール材などに、耐熱性・耐薬品性に優れ、パー
ティクルと呼ばれる微粒子やガスの発生の少ないフッ素
ゴム系シール材が使われている。2. Description of the Related Art A rubber-based sealing material made of a synthetic rubber as a main material, such as a rubber O-ring, and compounded with a rubber agent such as a vulcanizing agent, a plasticizer, and carbon black, and pressed and heated with a mold. Is widely used in various industrial devices and equipment because it is soft, has good compatibility with the joining surface (flange surface and the like), and has excellent sealing properties. Among them, in the semiconductor industry, fluorine rubber-based sealing materials that are excellent in heat resistance and chemical resistance and generate little particles or gas called particles are used as sealing materials for chemical liquid lines in processes such as etching. .
【０００３】このフッ素ゴムはフッ素によって炭素鎖が
結合され不飽和結合を含まぬため、化学的に極めて安定
であり、加工性は良好とはいえないが、アミンや過酸化
物による架橋が可能で、ゴム中で最も耐熱性、耐油性、
耐候性、耐オゾン性に優れている。そして、このフッ素
ゴムの中には、六フッ化プロピレンとフッ化ビニリデン
の共重合体であるバイトン、ダイエルで代表される主鎖
の一部に炭素−水素結合が存在するＦＫＭと分類される
タイプと、主鎖が完全にフッ素化されているＦＦＫＭと
分類されるパーフロロエラストマーとがあり、特にパー
フロロエラストマーは従来のフッ素ゴム（ＦＫＭ）を上
回る耐熱性、耐薬品性を有しているため、半導体デバイ
スの製造においてエッチング工程等で使われる場合が多
かった。[0003] This fluororubber is extremely stable chemically and does not have good processability because the carbon chain is bonded by fluorine and does not contain an unsaturated bond, but it can be crosslinked with amines or peroxides. The most heat and oil resistant in rubber,
Excellent weather resistance and ozone resistance. Among these fluororubbers, there are Viton, which is a copolymer of propylene hexafluoride and vinylidene fluoride, and a type classified as FKM in which a carbon-hydrogen bond exists in a part of the main chain represented by Daiel. And perfluoroelastomers classified as FFKM whose main chain is completely fluorinated. In particular, perfluoroelastomers have higher heat resistance and chemical resistance than conventional fluororubber (FKM). In many cases, it is used in an etching process or the like in the manufacture of semiconductor devices.
【０００４】[0004]
【発明が解決しようとする課題】ところが、最近このエ
ッチング工程は、半導体デバイスの集積度を上げるため
に、薬液中で溶解するウエットエッチング方式から、微
細加工の精度が良く加工形状を制御しやすい、気相中で
プラズマによりエッチングするドライエッチング方式に
変更され、この方式が主流となりつつある。これに対応
して、パーフロロエラストマーを主成分とするシール材
も、補強剤として用いているカーボンブラックをホワイ
トカーボン等の白色充填材に変更して、耐プラズマ性の
向上を図っているが、まだ十分ではない。特に、フロロ
カーボン系のエッチングガスに対する耐プラズマ性が不
十分である。However, recently, in order to increase the degree of integration of semiconductor devices, this etching process has been changed from a wet etching method in which a chemical is dissolved in a chemical solution, so that the precision of fine processing can be improved and the processing shape can be easily controlled. It has been changed to a dry etching method in which etching is performed by plasma in a gas phase, and this method is becoming mainstream. Correspondingly, the sealing material mainly composed of perfluoroelastomer has also been changed to carbon filler used as a reinforcing agent with a white filler such as white carbon to improve the plasma resistance. Not enough yet. In particular, the plasma resistance against fluorocarbon-based etching gas is insufficient.
【０００５】そのため、このフッ素ゴム系シール材がプ
ラズマにより劣化し、表面のゴムが粉末化してパーティ
クルとなったり、動的シール材として用いているような
部分ではゴムにねじれやひねりなどの応力が加わるた
め、クラックが入り破断することがあり、不良率の増大
やシール材の交換のために装置を頻繁に停止させるので
稼働率の低下につながり、半導体デバイスの製造上重大
な問題となっていた。本発明の目的は上記課題を解決す
るために、耐プラズマ性及びシール性に優れたフッ素ゴ
ム系シ一ル材を提供することにある。[0005] Therefore, the fluororubber-based sealing material is deteriorated by plasma, and the rubber on the surface is powdered to form particles. In a portion used as a dynamic sealing material, the rubber is subject to stress such as twisting or twisting. In addition, cracks may occur and break, increasing the defective rate and frequently stopping the apparatus for replacing the sealing material, leading to a reduction in the operating rate, which has become a serious problem in the manufacture of semiconductor devices. . An object of the present invention is to provide a fluororubber-based seal material having excellent plasma resistance and sealing properties in order to solve the above-mentioned problems.
【０００６】[0006]
【発明を解決しようとする手段】上記目的を達成するた
め、本発明者らは、エッチング等の装置に用いるシール
材の耐プラズマ性を上げるために検討を行った結果、フ
ッ素ゴム、特にパーフロロエラストマー、シリカ、硫酸
バリウムを所定量で配合したゴム成形品が高い耐プラズ
マ性を示し、またシール性などの一般特性も良好である
ことを見い出し、本発明を完成するに至った。In order to achieve the above object, the present inventors have studied to improve the plasma resistance of a sealing material used in an apparatus such as an etching apparatus. It has been found that a rubber molded product containing a predetermined amount of an elastomer, silica, and barium sulfate exhibits high plasma resistance and also has good general properties such as sealing properties, and has completed the present invention.
【０００７】即ち、本願の請求項１に係る発明は、フッ
素ゴム１００重量部に対して、シリカ１０〜２０重量部
及び硫酸バリウム２５〜３５重量部を含んでなる耐プラ
ズマ性シール材である。また、請求項２に係る発明は、
上記フッ素ゴム系シール材において、ゴムの種類がパー
フロロエラストマーである耐プラズマ性シール材であ
る。That is, the invention according to claim 1 of the present application is a plasma-resistant sealing material comprising 10 to 20 parts by weight of silica and 25 to 35 parts by weight of barium sulfate based on 100 parts by weight of a fluororubber. The invention according to claim 2 is
In the above fluororubber-based sealing material, the type of rubber is a plasma-resistant sealing material in which a perfluoroelastomer is used.
【０００８】[0008]
【作用】ここで、フッ素樹脂１００重量部に対してシリ
カ１０〜２０重量部及び硫酸バリウム２５〜３５重量部
含むゴム成形品が耐プラズマ性に優れる理由は、以下の
ように推察される。シリカはプラズマに対して遮蔽の効
果があるといわれており、シリカの量を増やしてゆくと
耐プラズマ性は改良される。しかし、シリカ量が多くな
りすぎるとゴム成形品のゴム弾性がなくなり、シール性
が著しく低下してしまう。また、シリカは超微粒子のた
め、ゴム中での分散があまり良くない。ところが、ここ
に硫酸バリウムを加えると、硫酸バリウムの真比重がシ
リカに比べて大きいため、ゴム中のシリカの分散を助け
る働きをし、シリカが比較的少ない量でもゴム中に均一
に分散され、耐プラズマ性に効果があるものと考えられ
る。The reason why the rubber molded article containing 10 to 20 parts by weight of silica and 25 to 35 parts by weight of barium sulfate with respect to 100 parts by weight of the fluororesin has excellent plasma resistance is presumed as follows. Silica is said to have a shielding effect on plasma, and the plasma resistance is improved as the amount of silica is increased. However, when the amount of silica is too large, the rubber elasticity of the rubber molded product is lost, and the sealing property is significantly reduced. Further, since silica is ultrafine particles, its dispersion in rubber is not very good. However, when barium sulfate is added here, since the true specific gravity of barium sulfate is larger than that of silica, the barium sulfate acts to assist the dispersion of silica in the rubber, and even a relatively small amount of silica is uniformly dispersed in the rubber, It is considered that this has an effect on plasma resistance.
【０００９】[0009]
【発明の実施の形態】以下、本発明を詳細に説明する。
フッ素ゴムとしては、主鎖に炭素−水素結合を含まず、
完全にフッ素化されているパーフロロエラストマーが耐
プラズマ性の点から最も好ましいが、条件の緩いところ
では、フッ化ビニリデンと六フッ化プロピレンとの共重
合体やフッ化ビニリデンと六フッ化プロピレン、四フッ
化エチレンとの共重合体、あるいは四フッ化エチレンと
プロピレンとの共重合体や四フッ化エチレンとプロピレ
ン、フッ化ビニリデンとの共重合体等の通常のフッ素ゴ
ムを用いることもできる。BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.
As a fluororubber, the main chain does not contain carbon-hydrogen bonds,
Perfluorinated elastomers that are completely fluorinated are most preferred from the viewpoint of plasma resistance, but where the conditions are mild, copolymers of vinylidene fluoride and propylene hexafluoride or vinylidene fluoride and propylene hexafluoride, Ordinary fluororubbers such as a copolymer of ethylene tetrafluoride, a copolymer of ethylene tetrafluoride and propylene, a copolymer of ethylene tetrafluoride and propylene, and a copolymer of vinylidene fluoride can also be used.
【００１０】シリカとしては、超微粒子で高純度の一般
のゴム工業においてホワイトカーボンと称される無水け
い酸、含水けい酸を使用し、その表面処理したものや造
粒したものを用いることもできる。As silica, silica or hydrated silica, which is called ultra-fine and high-purity white carbon in the general rubber industry, may be used, and surface-treated or granulated silica may be used. .
【００１１】硫酸バリウムとしては、通常の工業用途に
使う製品を使用することができるが、粒子径の細かい沈
降性硫酸バリウムを用いるのが最も望ましい。As barium sulfate, products used for ordinary industrial applications can be used, but it is most preferable to use sedimentable barium sulfate having a fine particle diameter.
【００１２】上記シリカ及び硫酸バリウムの配合量は、
フッ素ゴム１００重量部に対して、シリカが１０〜２０
重量部、好ましくは１３〜１７重量部であり、硫酸バリ
ウムが２５〜３５重量部、好ましくは３０〜３５重量部
である。シリカ量が１０重量部未満では、十分な耐プラ
ズマ性が得られない。一方、シリカ量が２０重量部を越
える場合には、シール材のゴム弾性がなくなり、シール
性が低下する。硫酸バリウム量が２５重量部未満では、
ゴム中でのシリカの分散性が向上されず、耐プラズマ性
を改善できない。一方、硫酸バリウム量が３５重量部を
越える場合には、シリカの体積比が低くなり、耐プラズ
マ性改善の効果が低下してしまい好ましくない。The mixing amounts of the above silica and barium sulfate are as follows:
Silica is 10 to 20 with respect to 100 parts by weight of fluoro rubber.
Parts by weight, preferably 13 to 17 parts by weight, and barium sulfate 25 to 35 parts by weight, preferably 30 to 35 parts by weight. If the amount of silica is less than 10 parts by weight, sufficient plasma resistance cannot be obtained. On the other hand, when the amount of silica exceeds 20 parts by weight, the rubber elasticity of the sealing material is lost, and the sealing property is reduced. If the amount of barium sulfate is less than 25 parts by weight,
The dispersibility of the silica in the rubber is not improved, and the plasma resistance cannot be improved. On the other hand, when the amount of barium sulfate exceeds 35 parts by weight, the volume ratio of silica becomes low, and the effect of improving the plasma resistance decreases, which is not preferable.
【００１３】本発明のシール材には、必要に応じて、一
般のゴム配合に用いる加硫剤、加硫促進剤、加硫助剤、
受酸剤等のゴム配合薬品および可塑剤、補強剤、充填材
等を適量配合してもよい。The sealing material of the present invention may contain, if necessary, a vulcanizing agent, a vulcanization accelerator, a vulcanization aid, and a vulcanization accelerator used in general rubber compounding.
An appropriate amount of a rubber compounding chemical such as an acid acceptor, a plasticizer, a reinforcing agent, a filler and the like may be mixed.
【００１４】本発明のシール材の成型方法は特に制限さ
れず、一般的な金型による圧縮成型以外に、押し出し成
形等公知のゴム成型方法を用いることができる。また、
シール材の形状も制限されず、例えばＯリング状とする
ことができる。一例を示すと、加硫剤入りフッ素ゴムと
シリカ、硫酸バリウム及びその他の配合材料をオープン
ロールで混練後、Ｏリング用金型に充填して１６０℃で
１０分間架橋成形を行った後にオーブン中で１８０℃で
４時間二次加硫を行うことで、Ｏリングが得られる。The method for molding the sealing material of the present invention is not particularly limited, and a known rubber molding method such as extrusion molding can be used other than compression molding using a general mold. Also,
The shape of the sealing material is not limited, and may be, for example, an O-ring shape. As an example, after vulcanizing agent-containing fluorine rubber, silica, barium sulfate and other compounding materials are kneaded with an open roll, the mixture is filled in an O-ring mold, crosslinked at 160 ° C. for 10 minutes, and then crosslinked in an oven. By performing secondary vulcanization at 180 ° C. for 4 hours, an O-ring is obtained.
【００１５】[0015]
【実施例】以下実施例により本発明を詳しく説明する
が、本発明はこの実施例に限定されるものではない。 〔実施例１〕表１に示す、加硫剤を含むパーフロロエラ
ストマー１００重量部、シリカ（日本アエロジル（株）
製＃２００）１５重量部、硫酸バリウム（堺化学工業
（株）製Ｂ−１）３０重量部をオープンロールで混練
し、コンパウンドを得た。このコンパウンドを金型に充
填し、１６０℃で１０分間架橋成型を行った後、オーブ
ン中で１８０℃で４時間二次加硫を行ないＯリング（Ｐ
２６）を作成した。 〔比較例１〕表１の比較例１に示す配合を用いて実施例
１と同等のＯリングを作成した。 〔比較例２〕表１の比較例２に示す配合を用いて実施例
１と同等のＯリングを作成した。The present invention will be described in detail with reference to the following examples, but the present invention is not limited to these examples. Example 1 100 parts by weight of a perfluoroelastomer containing a vulcanizing agent shown in Table 1 and silica (Nippon Aerosil Co., Ltd.)
# 200) and 30 parts by weight of barium sulfate (B-1 manufactured by Sakai Chemical Industry Co., Ltd.) were kneaded with an open roll to obtain a compound. This compound was filled in a mold, crosslinked and molded at 160 ° C. for 10 minutes, and then subjected to secondary vulcanization at 180 ° C. for 4 hours in an oven to form an O-ring (P
26) was prepared. Comparative Example 1 An O-ring equivalent to that of Example 1 was prepared using the composition shown in Comparative Example 1 of Table 1. Comparative Example 2 An O-ring equivalent to that of Example 1 was prepared using the composition shown in Comparative Example 2 in Table 1.
【００１６】[0016]
【表１】 [Table 1]
【００１７】この実施例１、比較例１，２のＯリングを
ブラズマ試験装置に入れ、ＣＦ4ガス流量３０SCCM、高
周波電力１００Ｗ、電源周波数１３．５６MHzの条件で
５時間プラズマ照射を行なう試験を３回繰り返した。プ
ラズマ試験後の試料の重量減少率および内圧１０kgf/cm
2Ｇのヘリウムガスを用いてのシール試験の結果を表２
に示す。The O-rings of Example 1 and Comparative Examples 1 and 2 were placed in a plasma test apparatus, and plasma irradiation was performed for 5 hours under the conditions of a CF 4 gas flow rate of 30 SCCM, a high frequency power of 100 W, and a power supply frequency of 13.56 MHz. Repeated times. Weight loss rate of sample after plasma test and internal pressure 10kgf / cm
Table 2 The results of the seal test using helium gas 2 G
Shown in
【００１８】[0018]
【表２】 [Table 2]
【００１９】表２より判るように、実施例は重量減少率
が少なく、シール性も良好である。As can be seen from Table 2, the examples have a small weight loss rate and good sealing properties.
【００２０】[0020]
【発明の効果】以上述べたように、本発明により得られ
たフッ素ゴム系シール材は、耐プラズマ性やシール性が
良好で、半導体デバイスの製造においてエッチング工程
等に使用する装置のシール材として長期にわたり安定的
に使用することができる。As described above, the fluororubber sealing material obtained according to the present invention has good plasma resistance and sealing properties, and is used as a sealing material for an apparatus used in an etching process in the manufacture of semiconductor devices. It can be used stably for a long time.
Claims (2)
カ１０〜２０重量部及び硫酸バリウム２５〜３５重量部
を含んでなることを特徴とする耐プラズマ性シール材。1. A plasma-resistant sealing material comprising 10 to 20 parts by weight of silica and 25 to 35 parts by weight of barium sulfate based on 100 parts by weight of fluororubber.
ーであることを特徴とする請求項１記載の耐プラズマ性
シール材。2. The plasma-resistant sealing material according to claim 1, wherein said fluoro rubber is a perfluoroelastomer.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20202198A JP3632888B2 (en) | 1998-07-16 | 1998-07-16 | Plasma-resistant sealing material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20202198A JP3632888B2 (en) | 1998-07-16 | 1998-07-16 | Plasma-resistant sealing material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2000034466A true JP2000034466A (en) | 2000-02-02 |
| JP3632888B2 JP3632888B2 (en) | 2005-03-23 |
Family
ID=16450618
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20202198A Expired - Fee Related JP3632888B2 (en) | 1998-07-16 | 1998-07-16 | Plasma-resistant sealing material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3632888B2 (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1302500A2 (en) * | 2001-10-12 | 2003-04-16 | Nichias Corporation | Plasma-resistant fluorine-based elastomer sealing material |
| US7942425B2 (en) | 2002-10-25 | 2011-05-17 | Nok Corporation | Plasma resistant seal |
| JP2014114383A (en) * | 2012-12-10 | 2014-06-26 | Mitsubishi Cable Ind Ltd | Fluorine-containing elastomer composition and rubber member |
| CN115340648A (en) * | 2022-08-22 | 2022-11-15 | 上海森桓新材料科技有限公司 | Method for producing fluoropolymer containing fluorinated silica nanoparticles and method for producing fluororubber |
-
1998
- 1998-07-16 JP JP20202198A patent/JP3632888B2/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP1302500A2 (en) * | 2001-10-12 | 2003-04-16 | Nichias Corporation | Plasma-resistant fluorine-based elastomer sealing material |
| EP1302500A3 (en) * | 2001-10-12 | 2003-12-03 | Nichias Corporation | Plasma-resistant fluorine-based elastomer sealing material |
| US6787610B2 (en) | 2001-10-12 | 2004-09-07 | Nichias Corporation | Plasma-resistant fluorine-based elastomer sealing material |
| US7942425B2 (en) | 2002-10-25 | 2011-05-17 | Nok Corporation | Plasma resistant seal |
| JP2014114383A (en) * | 2012-12-10 | 2014-06-26 | Mitsubishi Cable Ind Ltd | Fluorine-containing elastomer composition and rubber member |
| CN115340648A (en) * | 2022-08-22 | 2022-11-15 | 上海森桓新材料科技有限公司 | Method for producing fluoropolymer containing fluorinated silica nanoparticles and method for producing fluororubber |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3632888B2 (en) | 2005-03-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP2858198B2 (en) | Semiconductor manufacturing equipment seal | |
| TWI406897B (en) | Fluorine-containing rubber composition capable of forming a crack-resistant sealing material and crack-resistant sealing material obtained from the composition | |
| JP6034689B2 (en) | Fluorine-containing elastomer composition and rubber member | |
| JP2006206874A (en) | Elastomer composition and molded form | |
| JP4254538B2 (en) | Elastomer molded product | |
| JP5228913B2 (en) | Fluorine-containing elastomer composition | |
| TWI381015B (en) | Fluororubber composition, fluororubber material using the composition and method for producing the fluororubber molding | |
| JP4534956B2 (en) | Fluorine-containing elastomer composition | |
| JP3632888B2 (en) | Plasma-resistant sealing material | |
| JP6018444B2 (en) | Fluorine-containing elastomer composition and rubber member | |
| JP3502616B2 (en) | Rubber composition and rubber molded product obtained by molding the same | |
| JP2001348462A (en) | Plasma resistant rubber composition and rubber material for plasma processing apparatus | |
| WO2000004083A1 (en) | Crosslinkable elastomer composition, sealing material produced from the composition, and filler for use therein | |
| JP4331368B2 (en) | Seal for semiconductor manufacturing equipment | |
| WO2000078871A1 (en) | Crosslinkable elastomer composition and molded article produced from the composition | |
| JP2003055577A (en) | Modified inorganic filler | |
| JP2002161264A (en) | Plasma-resistant seal | |
| JP2014114383A (en) | Fluorine-containing elastomer composition and rubber member | |
| JP3553415B2 (en) | Semiconductor manufacturing equipment seal | |
| JP7015418B2 (en) | Fluorine-containing elastomer composition and sealing material | |
| JP2002173543A (en) | Plasma-resistant molded product of fluorine-based elastomer | |
| JP2001164066A (en) | Plasma-resistant fluororubber composition | |
| WO2016104604A1 (en) | Fluorine-containing elastomer composition, molded article, seal material, and device | |
| JP6435454B2 (en) | Fluorine-containing elastomer composition, molded product thereof, and apparatus incorporating the molded product | |
| JP2015052032A (en) | Composition for o-ring and o-ring |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20041210 |
|
| 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: 20041215 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20041216 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| RD04 | Notification of resignation of power of attorney |
Free format text: JAPANESE INTERMEDIATE CODE: A7424 Effective date: 20060324 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20080107 Year of fee payment: 3 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20090107 Year of fee payment: 4 |
|
| LAPS | Cancellation because of no payment of annual fees |