JPH0828564A - Static pressure bearing and positioning stage using the bearing - Google Patents
Static pressure bearing and positioning stage using the bearingInfo
- Publication number
- JPH0828564A JPH0828564A JP18658094A JP18658094A JPH0828564A JP H0828564 A JPH0828564 A JP H0828564A JP 18658094 A JP18658094 A JP 18658094A JP 18658094 A JP18658094 A JP 18658094A JP H0828564 A JPH0828564 A JP H0828564A
- Authority
- JP
- Japan
- Prior art keywords
- bearing
- static pressure
- hydrostatic bearing
- holding plate
- portions
- 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.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C29/00—Bearings for parts moving only linearly
- F16C29/02—Sliding-contact bearings
- F16C29/025—Hydrostatic or aerostatic
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C32/00—Bearings not otherwise provided for
- F16C32/06—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings
- F16C32/0603—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion
- F16C32/0614—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings
- F16C32/0618—Bearings not otherwise provided for with moving member supported by a fluid cushion formed, at least to a large extent, otherwise than by movement of the shaft, e.g. hydrostatic air-cushion bearings supported by a gas cushion, e.g. an air cushion the gas being supplied under pressure, e.g. aerostatic bearings via porous material
-
- G—PHYSICS
- G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
- G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
- G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
- G03F7/70—Microphotolithographic exposure; Apparatus therefor
- G03F7/708—Construction of apparatus, e.g. environment aspects, hygiene aspects or materials
- G03F7/70858—Environment aspects, e.g. pressure of beam-path gas, temperature
- G03F7/709—Vibration, e.g. vibration detection, compensation, suppression or isolation
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Health & Medical Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Atmospheric Sciences (AREA)
- Toxicology (AREA)
- Environmental & Geological Engineering (AREA)
- Epidemiology (AREA)
- Public Health (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Chemical & Material Sciences (AREA)
- Dispersion Chemistry (AREA)
- Container, Conveyance, Adherence, Positioning, Of Wafer (AREA)
- Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
- Exposure And Positioning Against Photoresist Photosensitive Materials (AREA)
- Magnetic Bearings And Hydrostatic Bearings (AREA)
Abstract
Description
【0001】[0001]
【産業上の利用分野】本発明は、半導体製造装置、精密
工作機械あるいは精密測定機器などの位置決めステージ
等に用いられる静圧軸受およびこれを用いた位置決めス
テージに関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a static pressure bearing used in a positioning stage of semiconductor manufacturing equipment, precision machine tools, precision measuring instruments and the like, and a positioning stage using the same.
【0002】[0002]
【従来の技術】半導体製造装置、精密工作機械あるいは
精密測定機器などにおいては、基板または被加工物や被
測定物を保持する保持盤を露光光や加工工具あるいは測
定用の照明光に対して高精度かつ高速度で位置決めする
ことが要求される。そこで、上記保持盤とこれを支持ま
たは案内する支持台等を静圧軸受によって互いに非接触
に保ち、支持台の表面の凹凸による位置決め精度の低下
や、保持盤と支持台の間の摩擦による振動や熱の発生等
を防ぐのが望ましい。2. Description of the Related Art In semiconductor manufacturing equipment, precision machine tools, precision measuring equipment, etc., a substrate or a holding plate for holding a workpiece or an object to be measured is highly sensitive to exposure light, processing tools or illumination light for measurement. Positioning with high accuracy and high speed is required. Therefore, the holding plate and the support table that supports or guides the holding plate are kept in non-contact with each other by static pressure bearings, and the positioning accuracy is deteriorated due to the unevenness of the surface of the support table, and the vibration due to the friction between the holding plate and the support table It is desirable to prevent the generation of heat and heat.
【0003】従来の静圧軸受を用いた位置決めステージ
は、例えば、図5の(a)に立面図で示すように、一対
の案内部材101a,101bを有する支持台101
と、両案内部材101a,101bの間に配置された保
持盤102と、保持盤102を各案内部材101a,1
01bに沿って移動させる図示しない駆動装置からな
り、保持盤102の、各案内部材101a,101bに
対向する側縁には端面静圧軸受パッド102aが一対ず
つ合計4個設けられ、また、保持盤102の下面には、
図5の(b)に示すように、図示左右に一対ずつ合計4
個の底面静圧軸受パッド102bと、各底面静圧軸受パ
ッド102bの間に1個ずつ合計4個の永久磁石102
cが設けられている。A conventional positioning stage using a hydrostatic bearing has, for example, a support base 101 having a pair of guide members 101a and 101b as shown in an elevation view in FIG.
And a holding plate 102 arranged between the guide members 101a and 101b, and the holding plate 102 for the guide members 101a and 1b.
The holding plate 102 is provided with a total of four end face hydrostatic bearing pads 102a at the side edges of the holding plate 102 facing the guide members 101a and 101b. On the underside of 102,
As shown in (b) of FIG.
Four bottom surface hydrostatic bearing pads 102b and one permanent magnet 102 between each bottom surface hydrostatic bearing pad 102b.
c is provided.
【0004】端面静圧軸受パッド102aは、加圧気体
の静圧によって、保持盤102を案内する支持台101
の案内部材101a,101bに対して保持盤102を
非接触に保ち、底面静圧軸受パッド102bは、支持台
101の図示上面101cに対して保持盤102を非接
触に保つ。永久磁石102cは、磁気吸着力によって保
持盤102を支持台101の上面101cに吸引するこ
とで底面静圧軸受パッド102bに予圧を与え、その軸
受剛性を高めるものである。The end face static pressure bearing pad 102a is a support base 101 for guiding the holding plate 102 by the static pressure of pressurized gas.
The holding plate 102 is kept out of contact with the guide members 101a and 101b, and the bottom surface hydrostatic bearing pad 102b keeps the holding plate 102 out of contact with the upper surface 101c of the support base 101 in the figure. The permanent magnet 102c serves to apply a preload to the bottom surface hydrostatic bearing pad 102b by attracting the holding plate 102 to the upper surface 101c of the support base 101 by a magnetic attraction force, thereby increasing the bearing rigidity.
【0005】端面静圧軸受パッドおよび底面静圧軸受パ
ッドとしては、図6の(a)に示すように、案内部材ま
たは固定体111の表面111aに対向するパッド11
2の表面112aに1個あるいは複数の小孔113を設
けた自成絞り型や、同図の(b)に示すように、オリフ
ィス123を設けたオリフィス絞り型や、同じく(c)
に示すように、多孔質体133を設けた多孔質絞り型、
あるいは図示しない表面絞り型等の静圧軸受のなかから
所定の軸受特性を有するものが選定される。As the end face hydrostatic bearing pad and the bottom face hydrostatic bearing pad, as shown in FIG. 6A, the pad 11 facing the surface 111a of the guide member or the fixed body 111 is used.
No. 2 self-drawing type in which one or a plurality of small holes 113 are provided on the surface 112a, an orifice limiting type in which an orifice 123 is provided as shown in FIG.
, A porous drawing die provided with a porous body 133,
Alternatively, a hydrostatic bearing (not shown) having a predetermined bearing characteristic is selected from hydrostatic bearings.
【0006】[0006]
【発明が解決しようとする課題】しかしながら上記従来
の技術によれば、多孔質絞り型、自成絞り型、オリフィ
ス絞り型等の静圧軸受はそれぞれ特有の軸受特性を有
し、特に、露光装置等の位置決めステージにおいては、
基板の複数の露光領域を順次露光位置へ移動させるため
に位置決めステージを間欠的に駆動するとき、繰返し発
生する駆動力の反力によって振動を発生しやすいが、こ
のような振動に対する静圧軸受の特性が絞りの型式によ
って大きく異なることが判明した。すなわち、静圧軸受
の軸受間隙の寸法を周期的に変化させて、これに伴う軸
受間隙の気体の圧力変動を調べたときに、軸受間隙の寸
法の増減と同じ位相の振動成分で表わされる軸受剛性
(以下、「剛性」という。)kの周波数特性と、剛性か
ら90°の位相遅れの振動成分で表わされる減衰性Cω
の周波数特性については、図7に示すように、静圧軸受
の絞りの型式によって大きな差がある。However, according to the above-mentioned prior art, the static pressure bearings such as the porous diaphragm type, the self-made diaphragm type and the orifice diaphragm type each have their own unique bearing characteristics. For positioning stages such as
When the positioning stage is driven intermittently in order to sequentially move a plurality of exposure regions of the substrate to the exposure position, vibration is likely to occur due to the reaction force of the driving force that is repeatedly generated. It was found that the characteristics greatly differ depending on the type of diaphragm. That is, when the size of the bearing gap of the hydrostatic bearing is periodically changed and the pressure variation of the gas in the bearing gap due to this is investigated, the bearing expressed by the vibration component in the same phase as the increase or decrease in the size of the bearing gap. A frequency characteristic of rigidity (hereinafter referred to as "rigidity") k and a damping property Cω represented by a vibration component having a phase delay of 90 ° from the rigidity.
As shown in FIG. 7, there is a large difference in the frequency characteristics of the above, depending on the model of the throttle of the hydrostatic bearing.
【0007】多孔質絞り型の静圧軸受の剛性kは、図7
の(a)の破線による曲線Aで示すように、周波数fが
所定の周波数を越えると低下するが、自成絞り型やオリ
フィス絞り型の静圧軸受の剛性kはそれぞれ同図のそれ
ぞれ実線と一点鎖線による曲線B,Cで示すようにほぼ
一定の値を維持する。また、多孔質絞り型の静圧軸受の
減衰性Cωは、図7の(b)に破線による曲線Aで示す
ように、周波数fとともに一旦減少したのち、周波数f
がある値を越えると、正に転じて増加する傾向を有する
が、自成絞り型やオリフィス絞り型の静圧軸受の減衰性
Cωは、図7の(b)にそれぞれ実線と一点鎖線による
曲線B,Cで示すように、ほぼゼロの値を保つ。The rigidity k of the porous throttle type hydrostatic bearing is shown in FIG.
As indicated by a broken line A in (a) of FIG. 3, the frequency f decreases when the frequency f exceeds a predetermined frequency. However, the rigidity k of the self-throttle type or orifice throttle type static pressure bearing is the same as the solid line in FIG. A substantially constant value is maintained as indicated by the curves B and C indicated by the alternate long and short dash line. Further, as shown by a broken line curve A in FIG. 7B, the damping property Cω of the porous throttle type hydrostatic bearing decreases once with the frequency f and then decreases with the frequency f.
When it exceeds a certain value, it tends to increase to a positive value, but the damping property Cω of the self-throttle type or orifice throttle type static pressure bearing is shown by the solid line and the dashed line in FIG. As shown by B and C, the value is kept almost zero.
【0008】なお、自成絞り型およびオリフィス絞り型
の静圧軸受の剛性kおよび減衰性Cωは、多孔質絞り型
の静圧軸受を所定量だけ目づまりさせた状態の剛性およ
び減衰性とほぼ同様の周波数特性を有することが知られ
ている。The rigidity k and damping property Cω of the self-throttle type and orifice restricting type static pressure bearings are almost the same as those of the porous restricting type static pressure bearings clogged by a predetermined amount. It is known to have similar frequency characteristics.
【0009】このように、自成絞り型やオリフィス絞り
型の静圧軸受は全体的に剛性が高く振動の周波数によっ
て変化しないという利点を有するが、減衰性Cωがほぼ
ゼロであるため、位置決めステージの振動がしずまるま
でに長時間を要し、このために、位置決めを高速化する
ことができない。As described above, the self-throttle type or the orifice type static pressure bearing has an advantage that it has high rigidity as a whole and does not change depending on the frequency of vibration, but since the damping property Cω is almost zero, the positioning stage. It takes a long time for the vibrations of the components to stop, which makes it impossible to speed up the positioning.
【0010】また、多孔質絞り型の静圧軸受は、位置決
めステージの固有振動数に等しい周波数で減衰性Cωが
正に転じていれば、発生した振動は短時間でしずまる
が、所定の気孔率や透過率の多孔質体を用いる場合、剛
性の方は周波数が高くなると大幅に低下するために固有
振動数が低下して振幅が大きくなり、その結果、高精度
の位置決めが困難になる。Further, in the porous throttle type hydrostatic bearing, if the damping property Cω is positively turned at a frequency equal to the natural frequency of the positioning stage, the generated vibration will be stopped in a short time, but the porosity will be a predetermined value. In the case of using a porous body having a permeability or permeability, rigidity is significantly reduced as the frequency is increased, so that the natural frequency is reduced and the amplitude is increased. As a result, highly accurate positioning becomes difficult.
【0011】このように、静圧軸受は絞りの型式によっ
てそれぞれの軸受特性に一長一短があり、特に動特性に
ついては高剛性と高減衰性の双方を満足するものを設
計、製造するのは極めて困難である。As described above, the hydrostatic bearing has its merits and demerits in each bearing characteristic depending on the type of the throttle, and it is extremely difficult to design and manufacture a hydrodynamic bearing which satisfies both high rigidity and high damping characteristics. Is.
【0012】本発明は上記従来の技術の有する未解決の
課題に鑑みてなされたものであり、極めてすぐれた耐振
性を有する静圧軸受およびこれを用いた位置決めステー
ジを提供することを目的とするものである。The present invention has been made in view of the above-mentioned unsolved problems of the prior art, and an object of the present invention is to provide a hydrostatic bearing having excellent vibration resistance and a positioning stage using the hydrostatic bearing. It is a thing.
【0013】[0013]
【課題を解決するための手段】上記目的を達成するため
に、本発明の静圧軸受は、一対の対向面の間に気体を噴
出する多孔質体を有し、該多孔質体が分断手段によって
複数の部位に分断され、該複数の部位のうちの少なくと
も1つにその気孔を目づまりさせる目づまり処理を施さ
れていることを特徴とする。In order to achieve the above object, the hydrostatic bearing of the present invention has a porous body for ejecting gas between a pair of opposed surfaces, and the porous body has a dividing means. Is divided into a plurality of parts, and at least one of the plurality of parts is subjected to a clogging treatment for clogging the pores.
【0014】目づまり処理が表面に塗膜を設けることに
よることが望ましい。It is desirable that the clogging treatment be performed by providing a coating film on the surface.
【0015】[0015]
【作用】目詰り処理を施された部分は、減衰性はほぼゼ
ロであるが周波数によって剛性が変化することのない自
成絞り型やオリフィス絞り型と同様の周波数特性を有す
る。従って、静圧軸受全体の周波数特性は、振動の減衰
性を有する多孔質絞り型と剛性が不変である自成絞り型
またはオリフィス絞り型を組み合わせたものとなる。そ
こで、目づまり処理を施す部分と多孔質絞り型のままで
ある部分との比率や目づまり処理による透過率の低下量
を適切に選定すれば、位置決めステージ等の固有振動数
が高く、かつ、高い減衰性を有する静圧軸受を実現でき
る。このような静圧軸受を用いれば、位置決めステージ
等に大きな振動が発生するおそれがないうえに振動が発
生しても短時間でしずまるため、高速度で高精度の位置
決めが容易である。The part subjected to the clogging has a frequency characteristic similar to that of the self-throttle type or the orifice type in which the damping property is almost zero but the rigidity does not change depending on the frequency. Therefore, the frequency characteristic of the entire hydrostatic bearing is a combination of the porous throttle type having the vibration damping property and the self-throttle type or the orifice type which has the same rigidity. Therefore, if the ratio of the portion to be clogged and the portion that remains porous diaphragm type and the amount of decrease in transmittance due to the clogging are appropriately selected, the natural frequency of the positioning stage and the like is high, and It is possible to realize a hydrostatic bearing having high damping properties. When such a hydrostatic bearing is used, there is no possibility of generating large vibrations on the positioning stage and the like, and even if vibrations occur, the vibrations occur for a short period of time, which facilitates high-speed and high-precision positioning.
【0016】[0016]
【実施例】本発明の実施例を図面に基づいて説明する。Embodiments of the present invention will be described with reference to the drawings.
【0017】図1は、一実施例による位置決めステージ
を示すもので、(a)はその立面図、(b)は保持盤の
みを示す底面図である。本実施例の位置決めステージ
は、一対の案内部材1a,1bを有する支持台1と、両
案内部材1a,1bの間に配置された移動台である保持
盤2と、保持盤2を各案内部材1a,1bに沿って移動
させる図示しない駆動手段からなり、保持盤2の各案内
部材1a,1bに対向する側縁には端面静圧軸受パッド
2aが一対ずつ合計4個設けられ、また、保持盤2の下
面には、図示左右の側縁に隣接して一対ずつ合計4個の
静圧軸受である底面静圧軸受パッド2bと、各底面静圧
軸受パッド2bの間に1個ずつ合計4個の永久磁石2c
が設けられている。1A and 1B show a positioning stage according to an embodiment, FIG. 1A is an elevation view thereof, and FIG. 1B is a bottom view showing only a holding plate. The positioning stage of the present embodiment includes a support base 1 having a pair of guide members 1a and 1b, a holding plate 2 which is a moving table arranged between the guide members 1a and 1b, and a holding plate 2 for guiding each of the guide members. The holding plate 2 is provided with a total of four end face hydrostatic bearing pads 2a at the side edges facing the respective guide members 1a, 1b. On the lower surface of the panel 2, a pair of bottom surface hydrostatic bearing pads 2b, which are a total of four hydrostatic bearings adjacent to the left and right side edges in the figure, and a total of four hydrostatic bearing pads between the bottom surface hydrostatic bearing pads 2b are provided. One permanent magnet 2c
Is provided.
【0018】各端面静圧軸受パッド2aはオリフィス絞
り型の静圧軸受パッドであり、各底面静圧軸受パッド2
bは多孔質絞り型の静圧軸受パッドである。Each end surface static pressure bearing pad 2a is an orifice throttle type static pressure bearing pad, and each bottom surface static pressure bearing pad 2
Reference numeral b is a porous throttle type hydrostatic bearing pad.
【0019】端面静圧軸受パッド2aは、保持盤2を案
内する支持台1の案内部材1a,1bに対して保持盤2
を非接触に保ち、また、底面静圧軸受パッド2bは、保
持盤2を支持する支持台1の図示上面1cに対して保持
盤2を非接触に保つ。永久磁石2cは磁気吸着力によっ
て保持盤2を支持台1の上面1cに吸引することで、底
面静圧軸受パッド2bに予圧を与え、その剛性を高める
働きをする。保持盤2はこのように支持台1上に非接触
で支持され、前述の駆動手段の駆動によって案内部材1
a,1bに沿って移動され、保持盤2に保持された基板
や被加工物あるいは被測定物を所定の位置へ位置決めす
る。The end face hydrostatic bearing pad 2a is held by the holding plate 2 with respect to the guide members 1a and 1b of the support base 1 for guiding the holding plate 2.
And the bottom surface hydrostatic bearing pad 2b keeps the holding plate 2 in non-contact with the illustrated upper surface 1c of the support base 1 that supports the holding plate 2. The permanent magnet 2c attracts the holding plate 2 to the upper surface 1c of the support base 1 by a magnetic attraction force, thereby preloading the bottom surface static pressure bearing pad 2b and increasing its rigidity. The holding plate 2 is thus supported on the support base 1 in a non-contact manner, and the guide member 1 is driven by the driving means described above.
The substrate, the work piece, or the measurement object, which is moved along a and 1b and held by the holding plate 2, is positioned at a predetermined position.
【0020】各底面静圧軸受パッド2bは、図2に示す
ように、保持盤2の底面と一体である軸受ハウジング2
1と、これに支持された多孔質体22と、軸受ハウジン
グ21の内部に形成された図示しない給気室に気体を供
給する給気管23を有し、給気管23は外部のコンプレ
ッサ等の加圧気体供給源に接続される。As shown in FIG. 2, each bottom surface hydrostatic bearing pad 2b is a bearing housing 2 which is integral with the bottom surface of the holding plate 2.
1, a porous body 22 supported by the same, and an air supply pipe 23 for supplying gas to an air supply chamber (not shown) formed inside the bearing housing 21. The air supply pipe 23 is an external compressor or the like. Connected to a pressurized gas source.
【0021】各底面静圧軸受パッド2bの多孔質体22
は、十字型に交差する分断手段である溝22aによって
4個の互いに独立した部位である方形部位22b〜22
eに分割され、そのうちの2つの方形部位22c,22
dはラッカー等の塗膜によってその表面の気孔を目づま
りさせる目づまり処理を施されており、自成絞り型やオ
リフィス絞り型と同様に減衰性はゼロであるが周波数に
よって剛性が変化することのない高剛性の静圧軸受とし
て機能するように構成されている。The porous body 22 of each bottom surface hydrostatic bearing pad 2b
Are four rectangular portions 22b to 22 which are independent of each other by the groove 22a which is a dividing means intersecting in a cross shape.
e is divided into two, and two of the square parts 22c and 22
d is subjected to a clogging treatment to clog the pores on the surface with a coating film such as lacquer. As with the self-throttle type and the orifice type, the damping property is zero, but the rigidity changes with frequency. It is configured to function as a high-rigidity hydrostatic bearing that has no
【0022】多孔質体22に供給された気体は、各方形
部位22b〜22eから矢印Rで示すように支持台1の
上面1cに向かって噴出され、その一部分は溝22aに
沿って流動したうえで多孔質体22の外周縁から排出さ
れ、残りは直接多孔質体22の外周縁から排出される。
このように流動する気体の静圧によって、保持盤2は支
持台1に非接触で支持される。The gas supplied to the porous body 22 is jetted from each of the rectangular portions 22b to 22e toward the upper surface 1c of the support 1, as shown by the arrow R, and a part of the gas flows along the groove 22a. Is discharged from the outer peripheral edge of the porous body 22, and the rest is directly discharged from the outer peripheral edge of the porous body 22.
The holding plate 2 is supported by the support base 1 in a non-contact manner by the static pressure of the flowing gas.
【0023】前述のように、目づまり処理を施された方
形部位22c,22dは振動の減衰性はゼロであるが高
剛性の静圧軸受として機能し、残りの方形部位22b,
22eは多孔質絞り型で特定の周波数以上で減衰性を有
するため、各方形部位22b〜22eの面積の比率や目
づまり処理による透過率の低下量を適切に選定すること
で、所定の周波数の振動に対して減衰性を有し、しかも
高剛性である静圧軸受を実現できる。As described above, the square portions 22c and 22d which have been subjected to the clogging function as a static bearing having a high rigidity although the damping property of the vibration is zero, and the remaining square portions 22b and 22d.
22e is a porous diaphragm type and has an attenuating property above a specific frequency. Therefore, by appropriately selecting the ratio of the area of each of the rectangular portions 22b to 22e and the decrease amount of the transmittance due to the clogging process, It is possible to realize a hydrostatic bearing that has damping properties against vibrations and that has high rigidity.
【0024】図3は、各方形部位22b〜22eの表面
積が50×70mm2 、厚さ5mm、気体は空気であっ
てその供給圧力4kgf/cm2 、軸受間隙4〜6μ
m、塗膜による目づまり処理を施す前の気孔率η=20
%、目づまり処理を施した方形部位22c,22dの透
過率q=43scc/cm2 /minである場合に、目
づまりを施さない方形部位22b,22eのみを用いた
静圧軸受の剛性kと減衰性Cωのそれぞれの周波数特性
を破線による曲線A1 ,B1 で示し、目づまりを施した
方形部位22c,22dのみを用いた静圧軸受の剛性k
と減衰性Cωのそれぞれの周波数特性を一点鎖線による
曲線A2 ,B2 で示す。全部の方形部位22b〜22e
を用いた場合は、これらの剛性kおよび減衰性Cωがそ
れぞれ加算されて実線による曲線A3 ,B3 で示す周波
数特性を有し、保持盤2の振動系の固有振動数f1 が例
えば200Hzであれば、剛性kおよび減衰性Cωの双
方が充分である。従って、支持台1の上面1c上に非接
触で支持された保持盤2は、これを移動させる駆動力等
の外乱によって大きな振動を発生するおそれがないうえ
に、振動が発生しても短時間で消滅する。その結果、位
置決めの高速化、高精度化が容易である。In FIG. 3, the surface area of each of the square portions 22b to 22e is 50 × 70 mm 2 , the thickness is 5 mm, the gas is air, the supply pressure is 4 kgf / cm 2 , and the bearing gap is 4 to 6 μm.
m, porosity η = 20 before clogging with coating film
%, Rectangular portion 22c subjected to the clogging process, when the transmittance q = 43scc / cm 2 / min of 22 d, the square portion 22b is not subjected to Medzumari, the stiffness k of the hydrostatic bearing using the 22e only attenuation The respective frequency characteristics of the characteristic Cω are shown by broken line curves A 1 and B 1 , and the rigidity k of the hydrostatic bearing using only the clogged square portions 22c and 22d is shown.
The respective frequency characteristics of the attenuating property and the damping property Cω are shown by the curves A 2 and B 2 by the alternate long and short dash line. All square parts 22b to 22e
In the case of using, the rigidity k and the damping property Cω are added to have the frequency characteristics shown by the solid line curves A 3 and B 3 , and the natural frequency f 1 of the vibration system of the holding plate 2 is, for example, 200 Hz. Then, both the rigidity k and the damping property Cω are sufficient. Therefore, the holding plate 2 supported on the upper surface 1c of the support base 1 in a non-contact manner does not have a possibility of generating a large vibration due to a disturbance such as a driving force for moving the holding plate 2, and even if the vibration occurs, the holding plate 2 is short-lived. Disappears. As a result, it is easy to increase the speed and accuracy of positioning.
【0025】本実施例においては、多孔質体22が十字
型の溝22aによって4個の方形部位22b〜22eに
分断されているが、溝の形や分断される部位の形状は任
意に設定できる。例えば、図4に示すように、多孔質体
33の中央のひし形部位33bをこれを囲む溝33aに
よって周囲の部位33cから分断し、ひし形部位33b
のみに目づまり処理を施してもよい。In this embodiment, the porous body 22 is divided into four rectangular portions 22b to 22e by the cross-shaped groove 22a, but the shape of the groove and the shape of the divided portion can be set arbitrarily. . For example, as shown in FIG. 4, the rhombus portion 33b at the center of the porous body 33 is divided from the surrounding portion 33c by the groove 33a surrounding the rhombus portion 33b.
Only one of them may be subjected to clogging treatment.
【0026】なお、多孔質体の気孔率(あるいは多孔
率、通気率)ηは、その多孔質体の全面積に占める流体
が通る空間の容積の割合と定義し、百分率で表す。ま
た、流体の透過率q(あるいは、浸透率)とは、多孔質
体の流れに対する抵抗であり、単位時間内に所定の軸受
面積Sを透過する流体の流量Qを用いて、次式(1)で
定義される。The porosity (or porosity, air permeability) η of the porous body is defined as the percentage of the volume of the space through which the fluid occupies the entire area of the porous body, and is expressed as a percentage. Further, the fluid permeability q (or permeability) is the resistance to the flow of the porous body, and is calculated by the following equation (1) using the flow rate Q of the fluid that permeates a predetermined bearing area S within a unit time. ) Is defined by.
【0027】 q=(μ・t・Q)/(S・PS ) ・・・・・(1) ただし、μ:流体の粘度、t:多孔質体の厚さ、PS :
流体の給気圧とする。Q = (μ · t · Q) / (S · P S ) (1) where μ: viscosity of fluid, t: thickness of porous body, P S :
It is the supply pressure of the fluid.
【0028】[0028]
【発明の効果】本発明は上述のとおり構成されているの
で、次に記載するような効果を奏する。Since the present invention is configured as described above, it has the following effects.
【0029】極めてすぐれた耐振性を有する静圧軸受を
実現できる。このような静圧軸受を位置決めステージに
用いれば、位置決めの高速化や高精度化を大きく促進で
きる。A static pressure bearing having extremely excellent vibration resistance can be realized. If such a hydrostatic bearing is used for the positioning stage, it is possible to greatly accelerate the positioning speed and accuracy.
【図1】一実施例を示すもので、(a)はその立面図、
(b)は保持盤のみを示す底面図である。FIG. 1 shows an embodiment, in which (a) is an elevational view thereof,
(B) is a bottom view showing only the holding plate.
【図2】図1の底面静圧軸受パッドを拡大して示すもの
で、(a)は断面図、(b)は底面図である。2 is an enlarged view of the bottom surface hydrostatic bearing pad of FIG. 1, in which (a) is a sectional view and (b) is a bottom view.
【図3】図2の装置の周波数特性を説明するもので、
(a)は剛性、(b)は減衰性の周波数特性をそれぞれ
示すグラフである。3 is a diagram for explaining the frequency characteristic of the device of FIG.
(A) is a graph showing rigidity, and (b) is a graph showing damping frequency characteristics.
【図4】底面静圧軸受パッドの一部変更例を示す底面図
である。FIG. 4 is a bottom view showing a partially modified example of the bottom surface hydrostatic bearing pad.
【図5】従来例を示すもので、(a)はその立面図、
(b)は保持盤のみを示す底面図である。FIG. 5 shows a conventional example, in which (a) is an elevation view thereof,
(B) is a bottom view showing only the holding plate.
【図6】静圧軸受パッドの絞りの型式を説明するもの
で、(a)は自成絞り型、(b)はオリフィス絞り型、
(c)は多孔質絞り型をそれぞれ示す図である。6A and 6B are explanatory views of a model of a diaphragm of a hydrostatic bearing pad. FIG. 6A is a self-made diaphragm type, and FIG. 6B is an orifice diaphragm type.
(C) is a figure which shows each porous diaphragm type | mold.
【図7】静圧軸受パッドの剛性と減衰性の周波数特性を
説明する図である。FIG. 7 is a diagram illustrating frequency characteristics of rigidity and damping of a hydrostatic bearing pad.
1 支持台 1a,1b 案内部材 2 保持盤 2a 端面静圧軸受パッド 2b 底面静圧軸受パッド 2c 永久磁石 22 多孔質体 22a 溝 DESCRIPTION OF SYMBOLS 1 Support 1a, 1b Guide member 2 Holding board 2a End surface static pressure bearing pad 2b Bottom static pressure bearing pad 2c Permanent magnet 22 Porous body 22a Groove
Claims (3)
質体を有し、該多孔質体が分断手段によって複数の部位
に分断され、該複数の部位のうちの少なくとも1つにそ
の気孔を目づまりさせる目づまり処理を施されているこ
とを特徴とする静圧軸受。1. A porous body for ejecting a gas is provided between a pair of opposing surfaces, the porous body is divided into a plurality of parts by a dividing means, and at least one of the plurality of parts is provided with the porous body. A hydrostatic bearing characterized by being subjected to a clogging treatment to clog pores.
によることを特徴とする請求項1記載の静圧軸受。2. The hydrostatic bearing according to claim 1, wherein the clogging treatment is performed by providing a coating film on the surface.
て支持台上に非接触で移動自在に支持された移動台と、
これを移動させる駆動手段を有する位置決めステージ。3. A movable table which is movably supported on the supporting table in a non-contact manner by the hydrostatic bearing according to claim 1.
A positioning stage having drive means for moving the same.
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18658094A JPH0828564A (en) | 1994-07-15 | 1994-07-15 | Static pressure bearing and positioning stage using the bearing |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP18658094A JPH0828564A (en) | 1994-07-15 | 1994-07-15 | Static pressure bearing and positioning stage using the bearing |
Publications (1)
Publication Number | Publication Date |
---|---|
JPH0828564A true JPH0828564A (en) | 1996-02-02 |
Family
ID=16191033
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
JP18658094A Pending JPH0828564A (en) | 1994-07-15 | 1994-07-15 | Static pressure bearing and positioning stage using the bearing |
Country Status (1)
Country | Link |
---|---|
JP (1) | JPH0828564A (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7319510B2 (en) | 2004-11-26 | 2008-01-15 | Canon Kabushiki Kaisha | Stage device, exposure apparatus using the unit, and device manufacturing method |
JP2019190591A (en) * | 2018-04-26 | 2019-10-31 | 学校法人東京理科大学 | Porous static pressure air bearing and its process of manufacture |
-
1994
- 1994-07-15 JP JP18658094A patent/JPH0828564A/en active Pending
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US7319510B2 (en) | 2004-11-26 | 2008-01-15 | Canon Kabushiki Kaisha | Stage device, exposure apparatus using the unit, and device manufacturing method |
JP2019190591A (en) * | 2018-04-26 | 2019-10-31 | 学校法人東京理科大学 | Porous static pressure air bearing and its process of manufacture |
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