JP2000034018A - Electrostatic levitation carrying device - Google Patents
Electrostatic levitation carrying deviceInfo
- Publication number
- JP2000034018A JP2000034018A JP20376298A JP20376298A JP2000034018A JP 2000034018 A JP2000034018 A JP 2000034018A JP 20376298 A JP20376298 A JP 20376298A JP 20376298 A JP20376298 A JP 20376298A JP 2000034018 A JP2000034018 A JP 2000034018A
- Authority
- JP
- Japan
- Prior art keywords
- electrostatic
- electrostatic levitation
- electrode plate
- electrode
- levitation
- 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
- Non-Mechanical Conveyors (AREA)
- Container, Conveyance, Adherence, Positioning, Of Wafer (AREA)
- Manipulator (AREA)
Abstract
Description
【０００１】[0001]
【発明が属する技術分野】本発明は、被搬送物を静電吸
引力により非接触で浮上させて搬送する静電浮上搬送装
置に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic levitation transport device for transporting an object by floating it in a non-contact manner by electrostatic attraction.
【０００２】[0002]
【従来の技術】従来、半導体製造工程などのクリーン度
の高い作業環境において、シリコンウェハやガラス基板
などの板状の被搬送物を非接触で搬送するのに用いられ
る静電浮上搬送装置は、図９のようになっている。 図
において、Sは靜電浮上搬送装置、２は絶縁基板ででき
た円形状の電極プレート、２ａ、２ｂは電極プレート２
上の分離帯、１a、１b、１c、１ｄは分離帯２ａ、２ｂ
を挟んで均等に分割された扇状の靜電浮上用電極で、各
々の電極に正電圧と負電圧とが交互に印加される。４は
靜電浮上用電極１a〜１dと対向するように配置された被
搬送物、３a、３b、３c、３dは靜電浮上用電極１a〜１d
と被搬送物４とのギャップを、半導体レーザを用いて光
量測定方式あるいは三角測量方式で検出する変位セン
サ、８は被搬送物４が目標位置に浮上できるように靜電
浮上用電極１a〜１dへ印加する電圧を制御する制御器で
ある。このような靜電浮上搬送装置Ｓは、変位センサ３
a〜３dにより得られた靜電浮上用電極１a〜１dと被搬送
物４間のギャップ検出値を制御器８にフィードバック信
号として送り、制御器８で各変位センサ３a〜３dからの
入力信号と予め設定された目標値を比較し、その偏差を
演算処理して被搬送物４が目標位置に安定浮上できるの
に必要な電圧Ｖa、Ｖb、Ｖc、Ｖdを作りだす。これによ
り靜電浮上用電極と被搬送物との間の静電吸引力を制御
し、被搬送物を非接触で浮上搬送させる。2. Description of the Related Art Conventionally, in a highly clean working environment such as a semiconductor manufacturing process, an electrostatic levitation transfer device used to transfer a plate-shaped transferred object such as a silicon wafer or a glass substrate in a non-contact manner is known. It is as shown in FIG. In the figure, S is an electrostatic levitation transfer device, 2 is a circular electrode plate made of an insulating substrate, 2a and 2b are electrode plates 2
Upper separators 1a, 1b, 1c and 1d are separators 2a and 2b
And positive and negative voltages are alternately applied to each electrode. Reference numeral 4 denotes a conveyed object arranged so as to face the electrostatic levitation electrodes 1a to 1d, and 3a, 3b, 3c and 3d denote electrostatic levitation electrodes 1a to 1d.
A displacement sensor for detecting the gap between the object 4 and the object 4 by a light quantity measuring method or a triangulation method using a semiconductor laser. The displacement sensor 8 is connected to the electrostatic levitation electrodes 1a to 1d so that the object 4 can float to a target position. This is a controller for controlling the applied voltage. Such an electrostatic levitation transfer device S includes a displacement sensor 3
The gap detection value between the electrostatic levitation electrodes 1a to 1d and the object 4 obtained by a to 3d is sent to the controller 8 as a feedback signal, and the controller 8 preliminarily inputs the input signals from the displacement sensors 3a to 3d. The set target values are compared with each other, and the deviation is calculated to generate voltages Va, Vb, Vc, and Vd necessary for the transferred object 4 to stably float at the target position. This controls the electrostatic attraction force between the electrostatic levitation electrode and the transferred object, and causes the transferred object to levitate and transfer without contact.
【０００３】[0003]
【発明が解決しようとする課題】ところが、従来技術で
は、以下に示すような問題があった。 （１）特に、被搬送物がガラス基板の場合、光量測定方
式の変位センサは、レーザ光がガラスを透過してしまい
ガラス表面からの反射光の光量が少ないため靜電浮上搬
送装置に使用することができなかった。また、三角測量
方式の変位センサは、レーザ光のガラス裏面から反射の
影響や、床などのガラスの下方にある物体からの反射の
影響により該装置に使用することができなかった。 （２）静電浮上搬送装置が用いられるクリーンルーム
は、高真空に保たれている場合が多いが、高真空中では
変位センサに用いられる半導体レーザの放熱が困難であ
るため、安定にレーザの発振ができなかった。 （３）変位センサを電極プレートの各々の靜電浮上用電
極の上方に設置する構成から取り付けスペースの確保が
必要なため、省スペース化に不向きという問題があっ
た。そこで、本発明は、被搬送物の材質または光学特性
に影響することなく被搬送物を安定に浮上することがで
きると共に、高真空中で発熱のない、小形に構成し得る
静電浮上搬送装置を提供することを目的とする。However, the prior art has the following problems. (1) In particular, when the object to be transferred is a glass substrate, the displacement sensor of the light amount measurement method should be used for the electrostatic levitation transfer device because the laser light passes through the glass and the amount of reflected light from the glass surface is small. Could not. In addition, the displacement sensor of the triangulation method cannot be used in the device due to the influence of the reflection of the laser light from the back surface of the glass or the influence of the reflection from an object below the glass such as the floor. (2) In a clean room in which an electrostatic levitation transfer device is used, a high vacuum is often maintained. However, in a high vacuum, it is difficult to radiate a semiconductor laser used for a displacement sensor, so that laser oscillation is stable. Could not. (3) Since a displacement sensor is required to be installed above each electrostatic levitation electrode of the electrode plate, it is necessary to secure a mounting space, which is not suitable for space saving. Therefore, the present invention provides an electrostatic levitation transfer device that can stably float a transferred object without affecting the material or optical characteristics of the transferred object and that can be configured in a small size without generating heat in a high vacuum. The purpose is to provide.
【０００４】[0004]
【課題を解決するための手段】上記問題を解決するた
め、請求項１の本発明は、絶縁基板からなる電極プレー
トと、前記電極プレート上に複数に分割配置されると共
に、正電圧または負電圧の少なくとも何れかが印加され
る靜電浮上用電極と、前記靜電浮上用電極と対向する被
搬送物と、前記被搬送物が目標位置に浮上できるように
前記靜電浮上用電極へ印加する電圧を制御する制御器
と、を備え、 前記靜電浮上用電極への電圧の印加により
前記被搬送物を静電吸引力により吸引して非接触で保持
して前記被搬送物を予定された位置に搬送させる静電浮
上搬送装置において、前記複数に分割された静電浮上用
電極は、前記電極プレートと空隙を介して対向配置さ
れ、前記電極プレートは、前記靜電浮上用電極との間を
接続するように設けた可撓性を有する梁部と、前記梁部
に設けられると共に、前記梁部が前記靜電浮上用電極の
静電吸引力で可動する際に生じる前記梁部の歪み量を検
出する歪み検出素子とよりなる力センサが設けられ、前
記力センサの検出信号に応じて前記制御器にフィードバ
ックするようにしたものである。請求項２の本発明は、
請求項１記載の静電浮上搬送装置において、前記電極プ
レートに、前記電極プレートの加速度を検出する加速度
センサが設けられ、前記加速度センサにより得た加速度
検出値に比例した前記被搬送物の慣性力を検出するよう
にしたものである。請求項３の本発明は、請求項１記載
の静電浮上搬送装置において、前記電極プレートに、前
記電極プレートが浮上した際に基準面となる床からの変
位を検出する変位センサが設けられ、前記変位センサの
変位検出値から演算により加速度を求めるようにしたも
のである。請求項４の本発明は、請求項１記載の静電浮
上搬送装置において、前記電極プレートは、ロボットの
マニピュレータに取付けられ、前記ロボットに内蔵され
たモータのエンコーダの回転速度から前記電極プレート
の加速度を検出するようにしたものである。上記手段に
より、力センサの信号をフィードバック信号として浮上
電極への印加電圧を制御し、静電浮上力をコントロール
することにより被搬送物を非接触に浮上させることがで
きる。そのため、光学式の変位センサが不要となり、高
真空のクリーンルーム内で使用できるし、被搬送物がガ
ラスの場合も浮上搬送することができる。In order to solve the above-mentioned problems, the present invention according to claim 1 has an electrode plate made of an insulating substrate and a plurality of positive electrodes or negative electrodes arranged on the electrode plate. Controlling an electrostatic levitation electrode to which at least one of the following is applied, a transferred object facing the electrostatic levitation electrode, and a voltage applied to the electrostatic levitation electrode so that the transferred object can float at a target position. And applying a voltage to the electrostatic levitation electrode to attract the object by electrostatic attraction, hold the object in a non-contact manner, and convey the object to a predetermined position. In the electrostatic levitation transport device, the plurality of divided electrodes for electrostatic levitation are arranged to face each other with a gap between the electrode plate and the electrode plate, and the electrode plate connects between the electrodes for electrostatic levitation. Can be provided A beam portion having flexibility, and a strain detecting element provided on the beam portion and detecting a strain amount of the beam portion generated when the beam portion is moved by electrostatic attraction of the electrostatic levitation electrode. A force sensor is provided, and feedback is provided to the controller in accordance with a detection signal of the force sensor. The invention of claim 2 is
2. The electrostatic levitation transfer device according to claim 1, wherein the electrode plate is provided with an acceleration sensor for detecting an acceleration of the electrode plate, and an inertial force of the transferred object is proportional to a detected acceleration value obtained by the acceleration sensor. Is detected. According to a third aspect of the present invention, in the electrostatic levitation transfer device according to the first aspect, the electrode plate is provided with a displacement sensor for detecting a displacement from a floor serving as a reference surface when the electrode plate floats, The acceleration is obtained by calculation from the displacement detection value of the displacement sensor. According to a fourth aspect of the present invention, in the electrostatic levitation transfer device according to the first aspect, the electrode plate is attached to a manipulator of a robot, and the acceleration of the electrode plate is determined based on a rotation speed of an encoder of a motor built in the robot. Is detected. With the above-described means, the transferred object can be levitated in a non-contact manner by controlling the voltage applied to the levitating electrode using the signal of the force sensor as a feedback signal and controlling the electrostatic levitating force. Therefore, an optical displacement sensor is not required, and the optical displacement sensor can be used in a high vacuum clean room, and can be levitated and conveyed even when the object to be conveyed is glass.
【０００５】[0005]
【発明の実施の形態】以下、本発明の実施例を図に基づ
いて説明する。図１は、本発明の第１の実施例を示す静
電浮上搬送装置であって、（ａ）は静電浮上搬送装置の
概略構成図、（ｂ）は電極プレートと静電浮上用電極の
配置を示す平面図、（ｃ）は電極プレートと静電浮上用
電極の配置を示す測断面図である。図において、従来と
同じ構成要素については同じ符号を付してその説明を省
略し、異なる点のみ説明する。本発明が従来と異なる構
成は以下のとおりである。すなわち、図１（ａ）におい
て電極プレート２と靜電浮上用電極１a、１b、１c、１d
との間に力センサ５ａ、５ｂ、５ｃ、５ｄを設け、各靜
電浮上用電極に加わる静電吸引力を検出するようにした
ものであり、制御器８は、力センサ５ａ〜５ｄからの検
出信号に応じて各静電浮上用電極１a〜１dに電圧を印加
するようになっている。また、力センサ５の構造を図１
（ｂ）にて説明する。電極プレート２の内部に円形状の
凹部が形成され、５１ａ、５１ｂ、５１、５１ｄは電極
プレート２の凹部の周縁部において靜電浮上用電極１a
〜１dとの間に設けた可撓性を有する材料から成る梁
部、５２ａ、５２ｂ、５２ｃ、５２ｄは各梁部５１ａ〜
５２ｄの表面にそれぞれ設けられ、静電浮上用電極１ａ
〜１ｄが静電吸引力で可動した際に生じる梁部５１ａ〜
５１ｄの歪み量を検出する歪みゲージであり。基本的に
力センサは梁部と歪みゲージから構成される。次に、動
作について説明する。静電浮上用電極１a〜１dにおい
て、制御器８から電圧が印加されると、静電浮上用電極
１a〜１dと被搬送物４の間に静電吸引力が働き、静電浮
上用電極１a〜１ｄが可動する。次に、この静電浮上用
電極１a〜１ｄの可動に基づいて梁部５１ａ〜５１ｄに
歪みが生じ、この歪み量が、梁部５１ａ〜５１ｄに設け
た歪みずゲージ５２ａ〜５２ｄで検出される。歪みゲー
ジ５２ａ〜５２ｄの出力は制御器８に送られ、結果とし
て力センサ５ａ〜５ｄからの静電吸引力として表される
検出信号に応じて各静電浮上用電極１a〜１dごとに分散
した電圧が印加される。一方、被搬送物４は静電浮上用
電極１a〜１dとの間に電圧が印加されて静電吸引力が働
くと、静電吸引力をＦｓ、被搬送物の質量をｍ、重力加
速度をｇとすれば、被搬送物４にはＦs−ｍｇの力が上
向きに働く。さらに静電吸引力を大きくしＦs＞ｍｇに
なると、被搬送物４は（Ｆs−ｍｇ）／ｍの加速度で上
昇する。上昇後、Ｆs＝ｍｇを保つように制御器８にフ
ィードバックがかけられ非接触に浮上ができる。したが
って、電極プレートと静電浮上用電極との間に、静電浮
上用電極へ印加される静電吸引力に対応した歪み量を検
出する力センサを設け、静電吸引力を直接検出するよう
にしたので、被搬送物がガラス基板の場合において、光
学式の変位センサによりガラス基板の材質または光学特
性に影響されるような変位検出を行うことが不要とな
り、被搬送物を安定に浮上することができる。また、力
センサを用いることで放熱の影響がなく高真空のクリー
ンルーム内で使用できると共に、該装置における省スペ
ース化も可能となる。DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIGS. 1A and 1B show an electrostatic levitation transport device according to a first embodiment of the present invention, wherein FIG. 1A is a schematic configuration diagram of the electrostatic levitation transport device, and FIG. FIG. 2C is a plan view showing the arrangement, and FIG. 2C is a sectional view showing the arrangement of the electrode plate and the electrodes for electrostatic levitation. In the drawings, the same components as those in the related art are denoted by the same reference numerals, and description thereof will be omitted. Only different points will be described. The configuration in which the present invention is different from the conventional one is as follows. That is, in FIG. 1A, the electrode plate 2 and the electrodes for electrostatic levitation 1a, 1b, 1c, 1d
And force sensors 5a, 5b, 5c, and 5d are provided between them to detect an electrostatic attraction force applied to each electrostatic levitation electrode. The controller 8 detects the force from the force sensors 5a to 5d. A voltage is applied to each of the electrostatic levitation electrodes 1a to 1d according to a signal. The structure of the force sensor 5 is shown in FIG.
This will be described in (b). A circular concave portion is formed inside the electrode plate 2, and 51 a, 51 b, 51, and 51 d are formed at the periphery of the concave portion of the electrode plate 2 by an electrostatic levitation electrode 1 a.
1d, the beam portions 52a, 52b, 52c, and 52d made of a flexible material are provided at each of the beam portions 51a to 51d.
52d, each of which is provided on the surface of
Beam portions 51a generated when 1d is moved by electrostatic attraction
It is a strain gauge for detecting a strain amount of 51d. Basically, the force sensor is composed of a beam and a strain gauge. Next, the operation will be described. When a voltage is applied from the controller 8 to the electrostatic levitation electrodes 1a to 1d, an electrostatic suction force acts between the electrostatic levitation electrodes 1a to 1d and the transferred object 4, and the electrostatic levitation electrodes 1a 1d is movable. Next, the beams 51a to 51d are distorted based on the movement of the electrostatic levitation electrodes 1a to 1d, and the amount of distortion is detected by the gauges 52a to 52d without distortion provided on the beams 51a to 51d. . The outputs of the strain gauges 52a to 52d are sent to the controller 8, and are dispersed for each of the electrostatic levitation electrodes 1a to 1d according to a detection signal expressed as an electrostatic attraction force from the force sensors 5a to 5d as a result. A voltage is applied. On the other hand, when a voltage is applied between the transported object 4 and the electrostatic levitation electrodes 1a to 1d and an electrostatic attraction force is applied, the electrostatic attraction force is Fs, the mass of the transported object is m, and the gravitational acceleration is if g, force F s -mg the conveyed object 4 acts upward. Further becomes greatly F s> mg electrostatic attraction force, the carried object 4 increases at an acceleration of (F s -mg) / m. After rising, F s = mg can rise to the non-contact feedback is applied to the controller 8 so as to keep the. Therefore, a force sensor is provided between the electrode plate and the electrode for electrostatic levitation to detect a distortion amount corresponding to the electrostatic attractive force applied to the electrode for electrostatic levitation, and the electrostatic attractive force is directly detected. Therefore, when the object to be transported is a glass substrate, it is not necessary to perform the displacement detection that is affected by the material or the optical characteristics of the glass substrate by the optical displacement sensor, and the object to be transported stably floats. be able to. In addition, by using the force sensor, it can be used in a high-vacuum clean room without being affected by heat radiation, and the device can be saved in space.
【０００６】次に、この図１に示した静電浮上搬送装置
によるウェハおよびガラス基板の搬送例を説明する。ま
ず、図１に示す力センサ５ａ、５ｂ、５ｃ、５ｄを用い
て、静電浮上搬送装置によりウェハを搬送する際。初期
の静電浮上用電極１a、１b、１c、１dとウェハのギャッ
プを０．４ｍｍとした。次に、静電浮上用電極１ａ、１
ｃへ＋６００Ｖ、１ｂ、１ｄへ−６００Ｖ印加すると、
ウェハは上昇をはじめた。この、上昇の始まりは、各力
センサ５ａ、５ｂ、５ｃ、５ｄから得られた静電浮上力
の和と、ウェハの自重が釣り合った時点である。その
後、各力センサ５ａ、５ｂ、５ｃ、５ｄから得られた静
電浮上力の和を制御器内の演算器で積分し上昇距離を求
めた。上昇距離が、初期ギャップの半分である０．２ｍ
ｍとなった時点で、各静電浮上用電極に働く静電浮上力
が、ウェハの自重の１／４となるように、各静電浮上用
電極に取り付けた力センサを用いてフィードバック制御
を行った。その結果、ウェハは、床面および浮上用電極
から離れた状態で、浮上することができた。つぎに、高
真空中において、図１に示す構成の静電浮上搬送装置を
配置し、浮上試験を行った。その結果、上述の場合と同
様に浮上することができた。光学式の変位センサを使っ
た従来の静電浮上搬送装置では、真空層内で１時間程度
使用すると光センサが発熱しギャップの計測ができなく
なったが、本静電浮上搬送装置では、４８時間の連続搬
送試験においても何ら問題なく使用することができた。
よって、本発明は高真空における非接触搬送に非常に有
効である。次に、静電浮上搬送装置を使用して石英ガラ
スの浮上試験を行った。この場合にもウェハと同様に浮
上させることができた。光学式の変位センサを使用した
従来の静電浮上搬送装置では、ガラスの浮上はほとんど
できず、希に浮上できたとしても光量の変化によってガ
ラスを落下させてしまうことがあった。本発明の静電浮
上搬送装置で、室内の照明をオン・オフしながら浮上−
移動−設置という一連の搬送動作を図９示すロボットを
使い１０００回おこなったが、１度もガラスを落下させ
ることがなかった。 よって、本発明は、光学式の変位
センサでギャップが検知できないガラスなどの透明基板
の非接触搬送に有効である。さらに、この装置の電極プ
レートを手で持ち運んだが、ウェハは非接触に浮上した
ままであり、本発明の装置により、静電浮上搬送装置が
実現可能であることがわかった。なお、図２に示すよう
に静電浮上用電極の上部において、静電浮上用電極１ａ
〜１ｄと同様に扇状に４分割された絶縁材料からなる支
持部材６を形成し、支持部材６と電極プレート２とを梁
部５１ａ〜５１ｄで接続するようにしても良い。あるい
は、支持部材８は、４分割された扇形状のものに代え
て、図３に示すような一体化した１枚の円板状のものと
しても構わない。また、力センサの変形例として、図４
に示すように電極プレート２の形状を平板状とし、電極
プレート２の下方に対向配置した静電浮上用電極１a〜
１dと電極プレート２との間において各々の面に垂直方
向に弾性材料から成る支柱７を設けるようにしても良
い。あるいは電極プレート２と静電浮上用電極１ａ〜１
dとの間に支持部材６を設け、支柱７により支持部材６
を固定しても構わない。ここで、支柱７は、静電浮上用
電極１a〜１dのうち一つずつ設けても良く、あるいは複
数設けても構わない。この時、各電極に１つ設ける場合
は、電極の重心に配置するのが好ましい。また、静電浮
上用電極による被搬送物の浮上の安定性を向上させる手
段として、力センサの出力から求められる上昇時の加速
度（Ｆs−ｍｇ）／ｍの積分値から、上昇した距離ｄを
求め、この上昇距離ｄが所定の距離ｄ0に一致した時点
で、Ｆs＝ｍｇとなるように制御器によりフィードバッ
クをかけるようにしてもよい。その際、好ましくは所定
の距離ｄ0を初期状態での被搬送物と電極間ギャップの
半分にするとよい。これにより、被搬送物を安定に浮上
することができる。また、さらに図５に示すように、浮
上前の初期状態で被搬送物を可動支持物１１により支持
し、力センサから求められる浮上用電極に働く静電吸引
力が、被搬送物の自重と等しく（Ｆｓ＝ｍｇ）なったら
制御器８の指令によりフィードバックをかけ、被搬送物
を支持していた可動支持物１１を降下させるようにして
も良い。この場合、初期状態での被搬送物と電極間ギャ
ップを維持して、被搬送物を非接触に浮上することがで
きる。また、力センサの一部を構成する歪み検出素子と
して歪みゲージを設けたが、圧電素子を設けても構わな
い。Next, an example of the transfer of a wafer and a glass substrate by the electrostatic levitation transfer device shown in FIG. 1 will be described. First, when a wafer is transferred by the electrostatic levitation transfer device using the force sensors 5a, 5b, 5c, and 5d shown in FIG. The initial gap between the electrostatic levitation electrodes 1a, 1b, 1c, and 1d and the wafer was 0.4 mm. Next, the electrodes for electrostatic levitation 1a, 1
When + 600V is applied to c, -600V is applied to 1b and 1d,
The wafer began to rise. The start of the rise is when the sum of the electrostatic levitation forces obtained from the force sensors 5a, 5b, 5c, and 5d and the weight of the wafer are balanced. Thereafter, the sum of the electrostatic levitation forces obtained from each of the force sensors 5a, 5b, 5c, and 5d was integrated by an arithmetic unit in the controller to obtain a rising distance. 0.2m ascending distance is half of the initial gap
m, the feedback control is performed using a force sensor attached to each electrostatic levitation electrode so that the electrostatic levitation force acting on each electrostatic levitation electrode becomes 1/4 of the weight of the wafer. went. As a result, the wafer could be lifted away from the floor surface and the floating electrode. Next, in a high vacuum, an electrostatic levitation transfer device having the configuration shown in FIG. 1 was placed, and a levitation test was performed. As a result, it was possible to levitate as in the case described above. In the conventional electrostatic levitation transfer device using an optical displacement sensor, the optical sensor generates heat and cannot measure the gap when it is used for about one hour in a vacuum layer. It was able to be used without any problem in the continuous transfer test.
Therefore, the present invention is very effective for non-contact conveyance in a high vacuum. Next, a levitation test of quartz glass was performed using an electrostatic levitation transfer device. In this case as well, the wafer could be floated similarly to the wafer. In a conventional electrostatic levitation transfer device using an optical displacement sensor, the glass can hardly be floated, and even if it can be floated rarely, the glass may fall due to a change in the amount of light. With the electrostatic levitation transfer device of the present invention, levitation while turning on / off indoor lighting
A series of transfer operations of moving and setting were performed 1000 times using the robot shown in FIG. 9, but the glass was never dropped. Therefore, the present invention is effective for non-contact transfer of a transparent substrate such as glass whose gap cannot be detected by an optical displacement sensor. Furthermore, although the electrode plate of this apparatus was carried by hand, the wafer still floated in a non-contact manner, and it was found that the apparatus of the present invention can realize an electrostatic levitation transfer apparatus. In addition, as shown in FIG. 2, an electrode 1a for electrostatic levitation is provided above the electrode for electrostatic levitation.
1d, a support member 6 made of an insulating material divided into four in a fan shape may be formed, and the support member 6 and the electrode plate 2 may be connected by beams 51a to 51d. Alternatively, the support member 8 may be an integrated disk-shaped member as shown in FIG. 3 instead of the four-part fan-shaped member. As a modification of the force sensor, FIG.
As shown in FIG. 3, the electrode plate 2 has a flat plate shape, and the electrostatic levitation electrodes 1a to
A column 7 made of an elastic material may be provided between 1d and the electrode plate 2 in a direction perpendicular to each surface. Alternatively, the electrode plate 2 and the electrodes for electrostatic levitation 1a to 1
The supporting member 6 is provided between the supporting member 6 and the supporting member 6.
May be fixed. Here, the columns 7 may be provided one by one from the electrodes for electrostatic levitation 1a to 1d, or a plurality of columns may be provided. At this time, when one is provided for each electrode, it is preferable to arrange it at the center of gravity of the electrode. As a means to improve the stability of floating of the object to be conveyed by the electrostatic levitating electrode, from the integral value of the acceleration (F s -mg) / m at elevated obtained from the output of the force sensor, elevated distance d And the controller may provide feedback so that F s = mg when the rising distance d matches the predetermined distance d 0 . At this time, the predetermined distance d 0 is preferably set to half of the gap between the transferred object and the electrode in the initial state. Thereby, the transported object can be stably levitated. Further, as shown in FIG. 5, the transported object is supported by the movable support 11 in the initial state before the floating, and the electrostatic attraction force acting on the floating electrode obtained from the force sensor is determined by the own weight of the transported object. When it becomes equal (Fs = mg), feedback may be applied by a command from the controller 8 to lower the movable support 11 that has supported the transported object. In this case, the transported object can be levitated in a non-contact manner while maintaining the gap between the transported object and the electrodes in the initial state. Further, although the strain gauge is provided as a strain detecting element constituting a part of the force sensor, a piezoelectric element may be provided.
【０００７】本発明の第２の実施例を示す構成図を図６
に示す。すなわち、第１の実施例との基本的な違いは、
図に示される電極プレート２の上方に、電極プレート２
の加速度αを検出するための加速度センサ１２を取り付
けたものである。このような構成において、静電浮上用
電極１ａ〜１ｄを用いることにより、被搬送物４を静電
吸引により浮上させた後の搬送は、図示しないロボット
等のマニピュレータにより電極プレート２を垂直方向に
上昇させ、つぎに水平方向に移動させるようにしてい
る。電極プレート２が垂直方向に急速に上昇した場合
は、被搬送物４には重力と電極プレート２の加速度に比
例した慣性力が働き、その結果、浮上制御の外乱とな
る。一方、電極プレート２に取り付けた加速度センサ１
２により電極プレート２の加速度αを検出することでし
被搬送物４に加わる慣性力ｍαを求めることができる。
そのため、静電吸引力Ｆｓが被搬送物４に加わる重力ｍ
ｇと慣性ｍαと釣り合うように、すなわちＦｓ＝ｍｇ＋
ｍαとなるように、この加速度センサ１２の信号を制御
器８にフィードバックして制御をおこなうと、電極プレ
ート２が垂直方向に急速に上昇した場合にも安定に浮上
が行える。FIG. 6 is a block diagram showing a second embodiment of the present invention.
Shown in That is, the basic difference from the first embodiment is as follows.
The electrode plate 2 is placed above the electrode plate 2 shown in the figure.
Is attached with an acceleration sensor 12 for detecting the acceleration .alpha. In such a configuration, by using the electrostatic levitation electrodes 1a to 1d, the transport after the transported object 4 is levitated by electrostatic suction is performed by vertically moving the electrode plate 2 by a manipulator such as a robot (not shown). It is raised and then moved horizontally. When the electrode plate 2 rises rapidly in the vertical direction, an inertial force proportional to the gravity and the acceleration of the electrode plate 2 acts on the transferred object 4, and as a result, disturbance of the levitation control occurs. On the other hand, the acceleration sensor 1 attached to the electrode plate 2
By detecting the acceleration α of the electrode plate 2 by the method 2, the inertial force mα applied to the transferred object 4 can be obtained.
Therefore, the gravity m applied to the transferred object 4 by the electrostatic attraction force Fs
g and inertia mα, that is, Fs = mg +
When the signal from the acceleration sensor 12 is fed back to the controller 8 so as to be controlled to mα, control is performed, and stable floating can be performed even when the electrode plate 2 rises rapidly in the vertical direction.
【０００８】次に、本発明の第３の実施例を図８に示
す。すなわち、第１の実施例、第2の実施例との違い
は、電極プレート２の上方に、電極プレート２の床面１
４からの変位を計測する変位センサ１３を取り付けたも
のである。このような構成において、電極プレート２に
取り付けた変位センサ１３により、電極プレート２の変
位を検出し、その検出値を２回微分することで 電極プ
レート２の加速度αを求めるようにしたものであり、さ
らに被搬送物４に加わる慣性力ｍαを求めることができ
る。そのため、この変位センサ１３の信号を制御器１０
にフィードバックし静電吸引力Ｆｓが、被搬送物４に加
わる重力ｍｇと慣性ｍαと釣り合うように、Ｆｓ＝ｍｇ
＋ｍαとなるように制御をおこなうと、第１、第２の実
施例同様に被搬送物を安定に浮上するとができる、Next, a third embodiment of the present invention is shown in FIG. That is, the difference from the first embodiment and the second embodiment is that the floor surface 1 of the electrode plate 2 is located above the electrode plate 2.
4 is provided with a displacement sensor 13 for measuring a displacement from position 4. In such a configuration, the displacement sensor 13 attached to the electrode plate 2 detects the displacement of the electrode plate 2 and differentiates the detected value twice to obtain the acceleration α of the electrode plate 2. Further, the inertial force mα applied to the transferred object 4 can be obtained. Therefore, the signal of the displacement sensor 13 is transmitted to the controller 10
Fs = mg so that the electrostatic suction force Fs is balanced with the gravity mg applied to the transferred object 4 and the inertia mα.
When the control is performed so as to be + mα, the transported object can be stably levitated as in the first and second embodiments.
【０００９】次に、本発明の第４の実施例を図８に示
す。すなわち、第１〜第３の実施例との違いは、図８に
示す電極プレート２をマニピュレータ１５ａの先端部に
装着したロボット１５で説明すると、ロボット１５に内
蔵されたモータ１５ｂのエンコーダ１５ｃの回転速度信
号を演算することにより、電極プレート２の加速度を求
めるようにした点である。これにより第１〜第３の実施
例同様に、被搬送物を安定に浮上制御することができ
る。Next, a fourth embodiment of the present invention is shown in FIG. That is, the difference from the first to third embodiments is that the explanation will be made with the robot 15 in which the electrode plate 2 shown in FIG. 8 is mounted on the tip of the manipulator 15a. The point is that the acceleration of the electrode plate 2 is obtained by calculating the speed signal. As a result, similarly to the first to third embodiments, it is possible to stably control the floating of the transferred object.
【００１０】[0010]
【発明の効果】以上述べたように、本発明によれば、従
来必要であった光学式の変位センサを必要としないた
め、高真空中で静電浮上搬送装置を用いることができ
る。さらに、静電浮上用電極に加わる静電吸引力をフィ
ードバック信号として用いるため、被搬送物の材質、光
学特性によらず静電浮上搬送をおこなうことができる。
特に、従来の方法では、困難であったガラス基板の静電
浮上搬送を行うことができる。As described above, according to the present invention, since an optical displacement sensor, which is conventionally required, is not required, the electrostatic levitation transfer device can be used in a high vacuum. Furthermore, since the electrostatic attraction force applied to the electrostatic levitation electrode is used as a feedback signal, the electrostatic levitation transport can be performed regardless of the material and optical characteristics of the transported object.
In particular, it is possible to perform electrostatic levitation transfer of a glass substrate, which has been difficult with the conventional method.
【図１】本発明の第1の実施例を示す静電浮上搬送装置
であって、（ａ）は静電浮上搬送装置の概略構成図、
（ｂ）は電極プレートと静電浮上用電極の配置を示す平
面図、（ｃ）は電極プレートと静電浮上用電極の配置を
示す測断面図である。FIG. 1 is an electrostatic levitation transfer device according to a first embodiment of the present invention, in which (a) is a schematic configuration diagram of the electrostatic levitation transfer device,
(B) is a plan view showing the arrangement of the electrode plate and the electrode for electrostatic levitation, and (c) is a cross-sectional measurement diagram showing the arrangement of the electrode plate and the electrode for electrostatic levitation.
【図２】力センサと静電浮上用電極の間に支持基板を設
けた例を示す概略構成図である。FIG. 2 is a schematic configuration diagram showing an example in which a support substrate is provided between a force sensor and an electrode for electrostatic levitation.
【図３】力センサと静電浮上用電極の間に支持基板を設
けた例であり、支持基板を一体化した概略 構成図であ
る。FIG. 3 is an example in which a support substrate is provided between a force sensor and an electrode for electrostatic levitation, and is a schematic configuration diagram in which the support substrate is integrated.
【図４】力センサの変形例を示す概略構成図である。FIG. 4 is a schematic configuration diagram showing a modified example of the force sensor.
【図５】第１の実施例における可動支持部を設けた静電
浮上搬送装置の概略構成図である。FIG. 5 is a schematic configuration diagram of an electrostatic levitation transfer device provided with a movable support unit in the first embodiment.
【図６】本発明の第２の実施例を示す静電浮上搬送装置
の概略構成図である。FIG. 6 is a schematic configuration diagram of an electrostatic levitation transfer device according to a second embodiment of the present invention.
【図７】本発明の第３の実施例を示す静電浮上搬送装置
の概略構成図である。FIG. 7 is a schematic configuration diagram of an electrostatic levitation transfer device according to a third embodiment of the present invention.
【図８】本発明の第４の実施例を示す静電浮上搬送装置
の概略構成図である。FIG. 8 is a schematic configuration diagram of an electrostatic levitation transfer device according to a fourth embodiment of the present invention.
【図９】従来例を示す静電浮上搬送装置の概略構成図で
ある。FIG. 9 is a schematic configuration diagram of an electrostatic levitation transfer device showing a conventional example.
Ｓ：静電浮上搬送装置 １ａ，１ｂ、１ｃ、１ｄ：静電浮上用電極 ２：電極プレート ４：被搬送物 ５ａ、５ｂ，５ｃ、５ｄ力センサ ５1ａ、５1ｂ、５1ｃ、５1ｄ:梁部 ５2ａ、５2ｂ，５2ｃ，５2ｄ歪みゲージ（歪み検出素
子） 6:支持基板 7：支柱 8：制御器 １１：可動支持部 １２：加速度センサ １３：変位センサ １４：床 １５：ロボット １５ａ：マニピュレータ １５ｂ：モータ １５ｃ：エンコーダS: Electrostatic levitation transport device 1a, 1b, 1c, 1d: Electrostatic levitation electrode 2: Electrode plate 4: Loaded object 5a, 5b, 5c, 5d Force sensor 51a, 51b, 51c, 51d: Beam portion 52a, 52b, 52c, 52d Strain gauge (strain detecting element) 6: Support substrate 7: Support column 8: Controller 11: Movable support unit 12: Acceleration sensor 13: Displacement sensor 14: Floor 15: Robot 15a: Manipulator 15b: Motor 15c: Encoder
Claims (4)
極プレート上に複数に分割配置されると共に、正電圧ま
たは負電圧の少なくとも何れかが印加される靜電浮上用
電極と、前記靜電浮上用電極と対向する被搬送物と、前
記被搬送物が目標位置に浮上できるように前記靜電浮上
用電極へ印加する電圧を制御する制御器と、を備え、 前
記靜電浮上用電極への電圧の印加により前記被搬送物を
静電吸引力により吸引して非接触で保持して前記被搬送
物を予定された位置に搬送させる静電浮上搬送装置にお
いて、 前記複数に分割された静電浮上用電極は、前記
電極プレートと空隙を介して対向配置され、 前記電極プレートは、前記靜電浮上用電極との間を接続
するように設けた可撓性を有する梁部と、前記梁部に設
けられると共に、前記梁部が前記靜電浮上用電極の静電
吸引力で可動する際に生じる前記梁部の歪み量を検出す
る歪み検出素子とよりなる力センサが設けられ、 前記力センサの検出信号に応じて前記制御器にフィード
バックするようにしたことを特徴とする静電浮上搬送装
置。1. An electrode plate comprising an insulating substrate, an electrode for electrostatic levitation divided on the electrode plate and applied with at least one of a positive voltage and a negative voltage, and the electrode for electrostatic levitation And a controller that controls a voltage applied to the electrostatic levitation electrode so that the transferred object can levitate to a target position, by applying a voltage to the electrostatic levitation electrode. In the electrostatic levitation transport device that sucks the transported object by electrostatic attraction and holds the transported object in a non-contact manner and transports the transported object to a predetermined position, the electrostatic floating electrode divided into a plurality of The electrode plate is disposed opposite to the electrode plate via a gap, and the electrode plate is provided on the beam portion having flexibility provided to connect between the electrode for electrostatic levitation and the beam portion, The beam part A force sensor comprising a strain detecting element for detecting a strain amount of the beam portion generated when the electrode is moved by electrostatic attraction of the electrostatic levitation electrode is provided, and the controller is provided to the controller in accordance with a detection signal of the force sensor. An electrostatic levitation transfer device characterized in that feedback is provided.
加速度を検出する加速度センサが設けられ、前記加速度
センサにより得た加速度検出値に比例した前記被搬送物
の慣性力を検出するようにした請求項１記載の静電浮上
搬送装置。2. An apparatus according to claim 1, wherein said electrode plate is provided with an acceleration sensor for detecting an acceleration of said electrode plate, and detects an inertial force of said transferred object in proportion to a detected acceleration value obtained by said acceleration sensor. Item 2. The electrostatic levitation transfer device according to Item 1.
浮上した際に基準面となる床からの変位を検出する変位
センサが設けられ、前記変位センサの変位検出値から演
算により加速度を求めるようにした請求項１記載の静電
浮上搬送装置。A displacement sensor for detecting a displacement from a floor serving as a reference surface when the electrode plate floats, wherein an acceleration is obtained by calculation from a displacement detection value of the displacement sensor. The electrostatic levitation transfer device according to claim 1.
レータに取付けられ、前記ロボットに内蔵されたモータ
のエンコーダの回転速度から前記電極プレートの加速度
を検出するようにした請求項１記載の静電浮上搬送装
置。4. The electrostatic levitation transfer according to claim 1, wherein said electrode plate is attached to a manipulator of a robot, and detects acceleration of said electrode plate from a rotation speed of an encoder of a motor built in said robot. apparatus.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20376298A JP4143777B2 (en) | 1998-07-17 | 1998-07-17 | Electrostatic levitation transfer device and robot with electrostatic levitation transfer device |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP20376298A JP4143777B2 (en) | 1998-07-17 | 1998-07-17 | Electrostatic levitation transfer device and robot with electrostatic levitation transfer device |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| JP2000034018A true JP2000034018A (en) | 2000-02-02 |
| JP2000034018A5 JP2000034018A5 (en) | 2005-10-20 |
| JP4143777B2 JP4143777B2 (en) | 2008-09-03 |
Family
ID=16479416
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP20376298A Expired - Fee Related JP4143777B2 (en) | 1998-07-17 | 1998-07-17 | Electrostatic levitation transfer device and robot with electrostatic levitation transfer device |
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| Country | Link |
|---|---|
| JP (1) | JP4143777B2 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011041337A (en) * | 2009-08-06 | 2011-02-24 | Saitama Univ | Driver and driving method of equivalent capacity type actuator |
| JP2012238847A (en) * | 2011-05-12 | 2012-12-06 | Semiconductor Technologies & Instruments Pte Ltd | Configuration frame handler constituted to process configuration frames with plural sizes |
-
1998
- 1998-07-17 JP JP20376298A patent/JP4143777B2/en not_active Expired - Fee Related
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2011041337A (en) * | 2009-08-06 | 2011-02-24 | Saitama Univ | Driver and driving method of equivalent capacity type actuator |
| JP2012238847A (en) * | 2011-05-12 | 2012-12-06 | Semiconductor Technologies & Instruments Pte Ltd | Configuration frame handler constituted to process configuration frames with plural sizes |
Also Published As
| Publication number | Publication date |
|---|---|
| JP4143777B2 (en) | 2008-09-03 |
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