JP3739738B2 - Articulated arm transfer device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high reliability transfer unit. <P>SOLUTION: A joint-arm transfer unit 10, that adopts a rhomboid linkage structure formed by two pairs of front arms (12, 13, 14, 15) are disposed separated from each other, which are jointed so as to be rotatable at elbow portions and wrist portions. Each wrist portion supports holding means (25, 25'), and the elbow portions are moved by a pair of upper arms (17, 18) along a semi-circular path that is in mirror reflection symmetry. When each of the upper arms (17, 18) rotates about its adjacent shoulder joint portion, the upper arms (17, 18) go under either one of the front arms (12, 13, 14, 15) and overlap with each other. In this unit, one holding means (25, 25') always moves quickly in between extended position and stop position, and the other holding means (25, 25') moves slowly in a minute distance in between the stop position and retracted position. <P>COPYRIGHT: (C)2003,JPO

Description

【００２８】

【００２９】
上記より、本発明の複合アームは、プロセスモジュールの不作動時間を最小化し、それによってシステムの処理能力を向上させるという利点を有することが判る。
【００３０】
本発明はまた、第１エンドイフェクタを伸長させて基板をプロセスモジュールに受け渡すとき、第２エンドイフェクタ上の基板の中心は、駆動軸の位置を越えてその開放されたプロセスモジュールに接近することがない、という点に利点がある。これによって、第２基板はガスあるいは粒子によって汚染されたり、又は開いているプロセスモジュールの近傍において加熱あるいは冷却によって影響されることがない。図７は、本発明のこの特徴を詳細に示される。
【００３１】
図８は、同じアームが一旦停止位置にある状態を示している。この設計では、エンドイフェクタは、アームが一旦停止位置にあるとき、回転中心に非常に接近する。
【００３２】
エンドイフェクタの動きに対して速度及び／又は加速度の曲線を制御するのに、電子的あるいは機械的な制御手段（２００）（図７及び図８参照）を利用することができる。図９に示すように、制御手段（２００）の、動作パターンを与える代表的な制御システム（２００Ａ）は、ＩＢＭのＰＣコンピュータと、そのコンピュータにシリアルの通信線を介して接続され、ハーモニックドライブ（ＲＨー１１ ６００１ーＥ１００Ａ）のようなギアモータ／エンコーダパッケージを制御するブルックス・オートメーション社の制御ＰＣボード＃１１９５１によって構成される。
【００３３】
以上、実施例とともに本発明の原理を述べたが、実施例における特定の表現は包括的な例示であって、以下に述べる請求の範囲に述べられた本発明の範囲を限定するものではない。
【図面の簡単な説明】
【図１Ａ】 左側に伸長された位置にある、本発明による関節アーム組立体の平面図。
【図１Ｂ】 一旦停止位置にある、本発明による関節アーム組立体の平面図、
【図１Ｃ】 右側に伸長された位置にある、本発明による関節アーム組立体の平面図。
【図２】 本発明の実施例に用いられる従来装置の等角投影図。
【図２Ａ】 図２に示す装置の側面図。
【図２Ｂ】 バンド・ドラム組立体の側面図。
【図２Ｃ】 図２Ｂの線２Ｃ−２Ｃに沿った断面図。
【図２Ｄ】 図２Ｂの線２Ｄ−２Ｄに沿った断面図。
【図３】 本発明による関節アーム組立体の側面図。
【図４】 図３の関節アーム組立体の部分平面図。
【図５】 本発明による関節アーム組立体を用いた処理順序を示す概略図。
【図６】 従来装置を用いた処理順序を示す概略図。
【図７】 １つのウエハが処理室にあって、他のウエハが引戻し位置にある状態を示す図。
【図８】 図７のアームが停止位置にある状態を示す図。
【図９】 典型的な運動制御（motion control）サーボのブロック図である。[0001]
BACKGROUND OF THE INVENTION
Background art
1. Field of Invention
The present invention relates generally to a material transfer apparatus. The material to be transferred is not particularly limited. For example, a semiconductor wafer such as silicon or gallium arsenide, a semiconductor packaging substrate such as a high density interconnect substrate, a mask or a reticle. Image forming plates used in semiconductor manufacturing processes such as, and large area display panels such as active matrix LCD substrates.
[0002]
[Prior art]
2. Conventional technology
In the manufacture of semiconductor devices, when a fragile silicon wafer or the like is transferred between a plurality of work stations, that is, work positions, a specific problem occurs in handling the wafer. Silicon wafers are very fragile and have a highly polished surface. The wafer is slippery when it is moved suddenly. Such sliding causes the silicon wafers to wear or damages their edges in the event of a collision.
Many conventional techniques shown below have been disclosed as silicon wafer transfer devices.
U.S. Pat. No. 3,823,836 discloses an apparatus comprising a supply transfer platform having a plurality of shelves for holding silicon wafers and a drawer device having a vacuum chuck. The vacuum chuck is attached to an elevator that moves the chuck up and down. The silicon wafer is transferred from the supply transfer table to a desired work station by a horizontal transfer arm connected to the vacuum chuck.
U.S. Pat. No. 3,730,595 discloses a wafer transfer handling apparatus having an indexable transfer table for loading and unloading wafers into and from a work station. The wafer is moved in and out of the wafer transfer table on the air slide by a wafer discharge receiving arm having a plurality of directional air jets. The wafer release receiving arm controls the movement of the wafer between the transfer platform and the air slide, thereby transferring the wafer to and from the work station.
U.S. Pat. Nos. 4,062,463, 3,874,525 and 4,208,159 disclose wafer transfer devices that utilize pneumatic elements or gripping devices for wafer handling.
U.S. Pat. Nos. 4,666,366 and 4,909,701 are articulated arms that stretch or contract in a "skin-like" motion to transfer objects such as wafers between multiple locations. A wafer transfer handling apparatus having an assembly is disclosed. Two articulated arms, when one arm is driven by a motor, these two articulated arms expand and contract in a “similar to heel” or “similar to heel leg kick” motion Are operatively connected. The loading / unloading table is connected to the arm, and the object to be transferred is mounted on the mounting table.
[0003]
[Problems to be solved by the invention]
However, since the articulated arm assembly of the transfer device described above has only a single mounting table, there is a limit in terms of processing capability. From such a situation, there is a need for a transfer device with a simple structure and high reliability that does not damage the object to be transferred and can improve the processing capacity as compared with a conventional device.
[0004]
[Means for Solving the Problems]
Summary of invention
The present invention is a simple structure and reliable for transferring articles such as silicon wafers, camera lenses, crystal oscillators, etc., between a plurality of positions arranged on various surfaces extending in the axial direction and the radial direction. It is characterized by providing a high device. The apparatus of the present invention includes one support, two sets of front arms that are articulated with a pair of upper arms (or drive arms), and a mounting table (or end effector) that is connected to each set of front arms. And an end effector, or other suitable holding device, and a motor that drives one of the upper arms. A pair of upper arms and two pairs of front arms, when one upper arm is driven by a motor, the front arm expands and contracts with an action "similar to a heel" or "similar to kicking a heel leg" So that they are operatively connected. If the end effector in the extended position is empty with no articles and the end effector in the retracted position has articles, the end effector on the non-empty side will not be subjected to large acceleration and speed (otherwise The substrate, which is the article, moves relative to the end effector), and the empty end effector is pulled back with a large acceleration and speed. Thereby, the time interval from the delivery of the first substrate to the delivery of the next substrate can be shortened.
The articulated arm assembly is preferably coupled to the base via a rotary motor so that the entire articulated arm assembly can rotate in a radial plane. As with conventional devices with a single mounting table, the articulated arm assembly is rotated when each end effector is not in the extended position. However, unlike the prior art, in the device of the present invention, if one end effector is fully retracted, the other end effector is always in the fully extended position. Thus, in the present invention, the support rotates when both end effectors are in an intermediate “pause” position. The point of providing such a “pause” position is one important feature of the present invention.
Also, in one embodiment, the articulated arm assembly is preferably coupled to the base via a plurality of flexible bodies or levers that react to force to move the mounting table assembly in the axial direction. In another embodiment, the arm assembly is attached by means other than the flexible body so that the mounting table assembly can move in the axial direction over a wider range than that obtained by the flexible body. The assembly is adaptable to a variety of environments, for example, a vacuum chamber or other conditioned environment. Further, this assembly may be attached so that it can be moved in the vacuum chamber by sealing the assembly and its support with a vacuum seal.
[0005]
Detailed Description of the Invention
The apparatus of the present invention has a first shoulder pivot axis 50 and a second shoulder pivot axis 51. The center line of the device is equidistant from the first and second shoulder pivots. The first upper arm 18 is rotatably provided on the first shoulder pivot axis 50 and includes at least one first elbow pivot means spaced from the first shoulder pivot axis by the length of the upper arm. Have The second upper arm 17 is rotatably provided on the second shoulder pivot 51 and includes second elbow joint means including at least one second elbow pivot spaced from the second shoulder pivot by the length of the upper arm. Have The primary first front arm 12 has a primary first wrist pivot that is provided on the first elbow pivot and is spaced from the first elbow pivot by the length of the primary front arm. The primary second front arm 13 is provided on the second elbow pivot and has a primary second wrist pivot that is spaced from the second elbow pivot by the length of the primary front arm. The primary side holding means 25 is attached to the primary side wrist turning shaft. The primary side coupling mechanism provided between the primary side wrist pivots prevents the primary side holding means from rotating and restricts its movement to the movement along the center line. The sum of the length of the primary front arm plus the separation between one of the primary wrist pivots and the center line is the maximum separation between any elbow joint and the center line Is also big. The secondary side first front arm 14 is provided on the first elbow pivot axis, and has a secondary first wrist pivot axis that is separated from the first elbow pivot axis by the length of the secondary front arm. The secondary-side second front arm 15 has a secondary-side second wrist pivot that is provided on the second elbow pivot and is spaced from the second elbow pivot by the length of the secondary-front arm. The secondary side holding means 25 'is attached to both wrist pivots. The secondary side coupling mechanism provided between the secondary wrist turning shafts prevents the secondary side holding means from rotating and restricts its movement to movement along the center line. The sum of the length of the secondary forearm plus the separation between one of the secondary wrist pivots and the centerline is the maximum separation between any elbow joint and the centerline. Greater than distance. Further, means for driving the first upper arm to be rotatable in an angular range of more than 120 ° and not more than 180 ° is provided, and by this means, the primary side holding means is moved between the extended position on the primary side and the retracted position on the primary side. At the same time, the secondary side holding means is moved between the secondary side pull-back position and the secondary side extension position.
[0006]
The holding means is used to hold a semiconductor wafer or the like. This holding means moves along the center line. The speed of the holding means is a function of a component of the speed of the elbow swivel axis in a direction parallel to the center line. Therefore, if the angular velocity of the upper arm is constant, the velocity of the support body is maximized when the upper arms are expanded from each other.
[0007]
Here, the size obtained by adding the distance between one wrist pivot and the center line to the length of the front arm is “A”, and one shoulder pivot is added to the length of the upper arm. If the size of the distance between the center line and the center line is “B”, the following relationship is established. If A is less than B, the system will be inoperable before the upper arms expand each other. If A = B and the separation distance from the central axis of the shoulder pivot axis is equal to the separation distance from the central axis of the wrist pivot axis, the respective front arms are movable so as to overlap each other. If A = B and the separation distance from the centerline of the wrist pivot axis is greater than the separation distance from the centerline of the shoulder pivot axis, the wrist pivot may “overshoot” the shoulder pivot axis. If A = B (or A is greater than B) and the distance from the center axis of the wrist pivot is smaller than the distance from the center axis of the shoulder pivot, the wrist pivot is shoulder pivot There is no overlap with the axis.
The apparatus is symmetrical with respect to the center line.
[0008]
Normally, the difference between the length of the front arm and the length of the upper arm is very small, but in this condition, the holding means is approximately twice the arm length between the fully extended position and the pause position. On the other hand, the distance between the stop position and the fully retracted position moves only slightly longer than the above difference.
[0009]
The capability of the device of the present invention is that due to the characteristics of the drive structure as shown below, a single drive mechanism can provide different speeds along the common centerline to the two end effectors. When the elements of the drive mechanism are simplified, each end effector is driven by a generally diamond shaped drive structure. In the rhombus structure, one vertex is selected as the pivot axis, and both sides adjacent to the vertex rotate around the pivot axis. Now, considering the movement of this rhombus structure, when the sides on both sides adjacent to the apex rotate, the angle of the apex becomes 180 °, the area of the rhombus disappears, and a pair of adjacent side portions are adjacent to each other Overlapping a pair of sides. Then, when further rotated, the two pairs of sides indicate one of the following two movements. That is, it rotates so as to open the rhombus or rotate with the two pairs of sides kept overlapping so as to hold the closed rhombus. In the former, the vertex opposite to the vertex that is the pivot axis moves away from the vertex that is the pivot axis at a high speed. The latter gives no moving speed to any of these vertices.
[0010]
The structure of the device of the present invention is to apply different motions to the two drive structures by utilizing the above-mentioned properties. That is, one drive structure is actuated to open the diamond, giving the end effector a large speed, while the other drive structure is actuated to hold the closed rhombus, neglecting to that end effector Give only as fast as you can.
[0011]
The structure of the device according to the invention comprises a drive mechanism having a pair of drive arms rotating in opposite directions connected at one end, and when the drive arms rotate around the ends, their free ends (with respect to the centerline) ) It moves along a semi-circular orbit of mirror symmetry (mirror image). Two pairs of front arms spaced apart from each other are coupled between the free ends of the drive arms, and each pair of front arms supports a holding means (such as an end effector) at the connection between the front arms. To do. The link structure formed by the two pairs of front arms is usually a rhomboid rather than a pure rhombus. Specifically, each pair of front arms forms a rhomboid drive structure with the drive arm. From the state where the driving arm is located at one moving end (in this state, the driving arms are substantially adjacent to each other, and one holding means protrudes from the connecting end of the driving arm) In this state, when the drive arms move in a straight line, the protruding holding means moves rapidly toward the stop position, and the area formed by the rhomboid link structure is the center. It expands from a narrow strip along the line to a square and then shrinks to a narrow strip perpendicular to the centerline. The area formed by the rhomboid structure by the drive arm and the front arm with the holding means pulled back shows a change in shape substantially similar to the link structure. On the other hand, the area formed by the front arm with the drive arm and the non-retractable holding means is small, so that the non-retractable holding means moves only slightly.
[0012]
When the drive arm exceeds the “pause” position, the moving end on the opposite side (in this state, the drive arms are substantially adjacent to each other, and the holding means on the other side protrudes from the connecting end of the drive arm. ), The holding means pulled once and then pulled back move little, and the area formed by the rhomboid link structure is expanded from a narrow band shape perpendicular to the center line to a square, Then, it is shrunk to a narrow band shape along the center line. The rhomboid area formed by the drive arm and the front arm with the newly extended holding means results in a change in shape substantially similar to the link structure. On the other hand, the area formed by the drive arm and the front arm with the holding means pulled back changes only slightly.
[0013]
Thus, the feature of the present invention is that the characteristics of the rhombus structure are applied to the rhomboid structure, and different speeds are given to the two end effectors by a single drive mechanism.
[0014]
That is, according to the present invention, the retracted arm can be accelerated and decelerated very rapidly and safely without giving a large acceleration or deceleration to the second end effector. Therefore, when the end effector in the extended position is emptied after the wafer is delivered, the end effector in the retracted position can be provided with an advantage in terms of operating capability when it remains occupied by the wafer. . In many applications, the wafer is held on the end effector only by surface friction, so the rapid acceleration or deceleration of the end effector holding the wafer may cause the wafer to shift on the end effector. Is not preferable.
[0015]
1A, 1B and 1C illustrate an articulated arm assembly 10 according to the present invention. The joint arm assembly 10 includes a pair of first front arms 12 and 13 and a pair of second front arms 14 and 15. Each forearm is articulated by a suitable means such as a pin connection 16 with one upper arm (shown below the front arms 12 and 13). These front arms are driven by upper arms 17 and 18 (see FIG. 1B).
[0016]
1A, 1B and 1C show three basic positions of the articulated arm assembly 10. FIG. 1A shows the assembly 10 in a position that is substantially fully extended to the left with respect to the base 19. FIG. 1B shows the assembly 10 once in a stop or “original” position relative to the base 19. 1C shows the assembly 10 in a position that is substantially fully extended to the right with respect to the base 19.
[0017]
As shown in FIG. 2, upper arms 17 and 18 generally include circular gears 20 and 21, respectively. The gears 20 and 21 may be formed integrally as a part of the upper arms 17 and 18, or may be formed individually and then fixed to the upper arm by an appropriate fixing method. The gear 20 is operably connected to the drive pinion 22. The gear 20 is driven by the drive pinion 22, and the gear 20 drives the gear 21. Instead of the drive gears 20 and 21 and the pinion 22, a suitable drive mechanism such as a friction surface or a band drum assembly may be used. 2B, 2C and 2D show a suitable band and drum assembly. In these figures, the drum 100 is connected to the drum 101 by two bands 102 and 103. Band 102 is secured to drum 101 by screws 104 (or other attachment means such as rivets or welds), and band 102 is secured to drum 100 by screws 105. The band 103 is fixed to the drum 100 with a screw 107. The band 103 is fixed to the drum 100 with a screw 107. The bands 102 and 103 are tensioned and may be made of metal. Each band has a generally S-shape, which is the opposite of the two bands. Thus, when the band 100 rotates clockwise, the screw 105 pulls the band 102, thereby pulling the screw 104 and rotating the drum 101 counterclockwise. When the band 100 rotates counterclockwise, the screw 107 pulls the band 103, whereby the screw 106 is pulled and the drum 101 rotates clockwise. Therefore, when one of the drums 100 and 101 rotates, the other drums rotate in the opposite direction.
[0018]
As shown in FIG. 4, the wrist joints of the front arms 12 and 13 include semicircular anti-rotation gears 23 and 24. A mounting table (or end effector or other suitable holder) for transporting articles is connected to the anti-rotation gears 23 and 24 by bearings 26 and 27. Instead of the anti-rotation gears 23 and 24, any suitable means for preventing rotation of the ends of the upper arms 12 and 13 such as friction surfaces or drum and band assemblies may be used. Similarly, the front arms 14 and 15 include an anti-rotation gear and a mounting table connected thereto.
[0019]
Clearly, when drive pinion 22 rotates clockwise, gear 20 and drive arm 17 rotate counterclockwise, and gear 21 and drive segment 18 rotate clockwise.
[0020]
As a result, the front arms 14 and 15 are pulled back in a “similar to heel” motion, and the mounting table 25 ′ is moved toward the drive gears 20 and 21. The anti-rotation gears 23 'and 24' prevent the mounting table 25 'from turning, thereby moving the object to be transferred linearly.
[0021]
When the mounting table 25 ′ is pulled back toward the drive gears 20 and 21, the front arms 12 and 13 move so that the angle “a” (see FIG. 4) between the upper arms 12 and 13 increases. To do. However, the mounting table 25 in a position fully extended to the left side and sufficiently beyond the drive gears 20 and 21 is accelerated very slowly from the stopped state until the maximum speed is reached at the once stopped position shown in FIG. 1B. (Control by motion control curve). Thereafter, the mounting table 25 'moves toward a position sufficiently beyond the drive gears 20 and 21, and the front arms 12 and 13 continue to extend.
[0022]
For various reasons, the length of the front arms 12, 13, 14, and 15 (ie, the distance between the pivot axes plus the separation between the wrist pivot axis and the centerline) is determined by the upper arm 17. And 18 (that is, the distance between the pivot axes and the distance between the shoulder pivot axis and the center line). To achieve smooth movement, the front arm may be set slightly longer (eg, about 0.25 inches) than the upper arm. The length of this front arm depends on the dimensions of the transferred object. The larger the article, the longer the arm needs to be set.
[0023]
FIG. 2 is an exploded isometric view of a conventional device that can also be used in the present invention. The joint arm assembly 10 is disposed on a C-shaped support body 30 via shoulder joint portions 50 and 51. The electric motor 31 is attached to the support 30 and connected to the drive pinion 22. The drive pinion engages with the gear 20, and the gear 20 drives the gear 21, thereby expanding and contracting the joint arm assembly 10 as described above. The support 30 is connected to a shaft 32 that is pivotally supported by the second C-shaped support 33. The shaft 32 includes a rotation gear 34 connected to the electric motor 35 and rotates the joint arm assembly 10 as a whole. According to the present invention, once the arm is in the stop position, the mounting tables 25 and 25 'are mostly centered on the shaft 32 to minimize the centrifugal force on the substrate or substrates being transferred. Can do.
The support 33 is connected to the base 36 through C-shaped supports 37 and 38 and flexible bodies 41 to 44. A lifting mechanism 40 such as a solenoid is disposed on the base 36 and coupled to the lever 45. The lever 45 is disposed below the shaft 32. One end of the lever 45 acts as a first fulcrum 46 disposed on the base 36, and a second fulcrum (see FIG. 2A) is disposed at the bottom of the shaft 32. When the mechanism 40 is operated, the shaft 32 is displaced upward in the axial direction, and the flexible bodies 41 to 44 are bent. Obviously, when the shaft 32 is displaced in the axial direction, the articulated arm assembly 10 is also displaced in the overall axial direction.
[0024]
In accordance with the present invention, one or more of the motors 31 and 35 and the lifting mechanism 40 are controlled by electronic logic (not shown in FIG. 2) to precisely control the articulated arm assembly 10. .
[0025]
The front arms 12, 13, 14 and 15 are connected to the upper arms 17 and 18 by suitable means such that the joints do not adversely affect the movement. FIG. 3 shows an embodiment of a single axis elbow joint in which the front arms facing each other are coupled to the same axis. The front arm 15 includes a C-shaped portion 80 having a hole through which the elbow shaft 82 penetrates at the connecting end. Similarly, the front arm 13 includes a C-shaped portion 81 having a hole through which the elbow shaft 82 passes at the connecting end. The elbow shaft 82 is fixed to the upper arm 18 and cooperates with the upper arm 18 to form an elbow joint. The front arm 13 has a stepped portion 83, and the mounting table 25 is in the same horizontal plane as the mounting table 25 ′.
[0026]
5 and 6 show an example comparing the operation of the apparatus of the present invention with the operation of a conventional apparatus having only a pair of front arms. In these drawings, a module (unit) 1 indicates an area where a wafer is processed, and modules 2 and 3 indicate areas where a processed wafer and an unprocessed wafer are held, respectively. Tables 1 and 2 show the position of the joint arm assembly and the state of the process module corresponding to FIGS. 5 and 6, respectively.
[0027]

[0028]

[0029]
From the above, it can be seen that the composite arm of the present invention has the advantage of minimizing the down time of the process module and thereby improving the throughput of the system.
[0030]
The present invention also provides that when the first end effector is extended and the substrate is transferred to the process module, the center of the substrate on the second end effector approaches the opened process module beyond the position of the drive shaft. There is an advantage in that there is nothing to do. This prevents the second substrate from being contaminated by gas or particles or affected by heating or cooling in the vicinity of the open process module. FIG. 7 shows this feature of the invention in detail.
[0031]
FIG. 8 shows a state where the same arm is once in the stop position. In this design, the end effector is very close to the center of rotation once the arm is in the stop position.
[0032]
Electronic or mechanical to control velocity and / or acceleration curves for end effector movement Control means (200) (see FIGS. 7 and 8) Can be used. As shown in FIG. Of the control means (200) Typical giving motion pattern Control system (200A) Is an IBM PC computer connected to the computer via a serial communication line and controls a gear motor / encoder package such as a harmonic drive (RH-11 6001-E100A). 11951.
[0033]
Although the principle of the present invention has been described with the embodiments, specific expressions in the embodiments are comprehensive examples and do not limit the scope of the present invention described in the claims described below.
[Brief description of the drawings]
FIG. 1A is a plan view of an articulated arm assembly according to the present invention in a left extended position.
1B is a plan view of an articulated arm assembly according to the present invention once in a stopped position;
1C is a plan view of an articulated arm assembly according to the present invention in a position extended to the right. FIG.
FIG. 2 is an isometric view of a conventional apparatus used in an embodiment of the present invention.
2A is a side view of the apparatus shown in FIG.
FIG. 2B is a side view of the band and drum assembly.
2C is a cross-sectional view taken along line 2C-2C in FIG. 2B.
2D is a cross-sectional view taken along line 2D-2D of FIG. 2B.
FIG. 3 is a side view of an articulated arm assembly according to the present invention.
4 is a partial plan view of the joint arm assembly of FIG. 3. FIG.
FIG. 5 is a schematic diagram showing a processing sequence using the joint arm assembly according to the present invention.
FIG. 6 is a schematic diagram showing a processing order using a conventional apparatus.
FIG. 7 is a view showing a state where one wafer is in a processing chamber and another wafer is in a pull-back position.
FIG. 8 is a diagram showing a state where the arm of FIG. 7 is in a stop position.
FIG. 9 is a block diagram of a typical motion control servo.

Claims (4)

An apparatus for conveying an object (A, B),
Two upper arms (17, 18) rotatably connected to the support (19);
Two pairs of front arms, each pair of front arms being rotatably connected to the opposite outer ends of the two upper arms (12, 13, 14) 15)
First object holding means (25) connected to the first pair (12, 13) of the front arms;
Second object holding means (25 ′) connected to the second pair (14, 15) of the front arms;
Means (40) for raising the holding means (25, 25 ');
Means (200) capable of controlling movement of at least one of the object holding means (25, 25 ');
The controllable means (200) moves at least one of the object holding means (25, 25 ') at a first speed in a first direction between the first and last positions;
And when reversing from the last position, it is moved at a second speed in a second direction opposite to the first direction,
The second speed is different from the first speed;
Object transport device. Between the two upper arms (17, 18),
A mechanical coupling (20, 21) for rotating the two upper arms (17, 18) together in opposite directions;
The apparatus of claim 1. The means for raising (40) is connected to the support (19) for moving the support in a direction substantially parallel to the first axis of rotation of the first arm in the upper arm. Further comprising means of
The apparatus of claim 1. An apparatus (10) for transporting a semiconductor substrate comprising:
Two drive arms (17, 18) connected to the support (19);
Two pairs of driven arms, each pair of driven arms being rotatably connected to the opposite outer ends of the two driving arms (12, 13, 14, 15 )When,
First substrate holding means (25) connected to the first pair (12, 13) of said driven arms;
Second substrate holding means (25 ′) connected to the second pair (14, 15) of said driven arms;
The drive arms are rotatable to move toward and away from each other, thereby moving two pairs of driven arms,
The driven arm can thereby extend and retract the first and second substrate holding devices in relation to the rotational range of the two drive arms connected to the support,
And supplying each of the substrate holding devices with an extended position, a retracted position, and a fully retracted position;
Furthermore, it comprises means (200) for controlling the rotation of the drive arms (17, 18),
This causes at least one of the substrate holding means (25, 25 ′) to move at a first speed in a first direction between the extended position and the retracted position,
The at least one substrate holding means is moved at a second speed in a second direction opposite to the first direction between the extended position and the retracted position;
The second speed is different from the first speed;
Device for transporting semiconductor substrates.

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