JP2009172733A - Horizontally articulated robot - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To maintain highly accurate conveyance by minimizing an attitude change of an arm caused by a thermal influence when conveying a high temperature substrate, in a horizontally articulated robot. <P>SOLUTION: In this horizontally articulated robot, the arm is constituted of a transmission mechanism for transmitting a rotating operation from a driving part 1, an arm case 201 for storing the transmission mechanism and an arm cover 214 mounted on an upper surface of the arm case 201 to cover the transmission mechanism. The arm cover 214 is constituted of a plurality of arm covers divided in a direction in which the arm case 201 is extended, and the plurality of arm covers 214 form mutually-folded parts. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a configuration in which a substrate can be transported with high accuracy by minimizing a change in the posture of an arm due to radiant heat of a substrate in a horizontal articulated robot that transports a high-temperature substrate mounted on a hand.

In a semiconductor or liquid crystal manufacturing apparatus (hereinafter simply referred to as a manufacturing apparatus), a horizontal articulated transfer robot is generally used to transfer a substrate such as a semiconductor wafer or liquid crystal. A horizontal articulated robot is composed of a plurality of arms that are rotatably connected to each other in a horizontal plane, a drive unit that rotates these arms, and a hand that is connected to the most advanced arm and can mount a substrate. Then, by rotating the arm by the drive unit, the hand is swung and expanded and contracted, and the substrate on the hand is transported to a desired position.
FIG. 4 shows the configuration of a conventional horizontal articulated robot. (A) is a top view and (b) shows the side view. In FIG. 4, a drive unit 1 is a drive unit formed in a casing shape, and is a part that rotationally drives a plurality of arms. A rotary motor (not shown) is disposed inside the drive unit 1 and rotationally drives each arm. The first arm 100 is an arm whose base end is supported on the upper surface of the drive unit 1 so as to be rotatable in a horizontal plane. The base end of the second arm 200 is rotatably supported on the top surface of the first arm 100 in a horizontal plane. A third arm 300 is supported on the top end surface of the second arm 200 so as to be rotatable in a horizontal plane. A hand 400 on which the substrate 500 can be mounted is fixed to the third arm 300. The hand 400 is composed of two hands (a first hand 400a and a second hand 400b) having the same shape at positions 180 degrees symmetrical with respect to the rotation center of the third arm 300, and each of the two hands is a substrate. 500 can be installed.
4C and 4D are exploded views showing the configuration of the first arm 100 or the second arm 200. FIG. Here, description will be made assuming that the second arm 200 is shown. (C) is a top view and (d) is a side sectional view. As shown in the figure, the casing of the second arm 200 is formed in a casing shape (second arm case 201). A transmission mechanism for posture control of the third arm 300 is accommodated therein. A transmission mechanism using a belt and a pulley or a transmission mechanism is known. Here, a belt and pulley are used. A thin plate-like cover is provided on the upper surface of the second arm case 201 so as to cover the transmission mechanism in order to suppress scattering of dust generated from the transmission mechanism and to protect the transmission mechanism itself (second Arm cover 214). The second arm cover 214 is formed in a thin plate shape so as to cover the upper surface of the second arm case 201 without a gap, and only a portion for attaching the third arm 300 not shown in FIGS. It has been configured.
With the above configuration, when the horizontal articulated robot rotates the first arm 100 by a predetermined amount α ° by the driving unit 1, the second arm 200 also moves on the tip of the first arm 100 by the predetermined amount (α °). By rotating, the third arm 300 is rotated on the tip of the second arm 200 by a predetermined amount α °, and the third arm 300 is expanded and contracted in a radial direction from the rotation center of the first arm 100. be able to. In addition, the horizontal articulated robot rotates the first arm 100 and the second arm 200 in the same direction to maintain the relative posture of each arm, while maintaining the third arm 300 at the center of rotation of the first arm 100. And the substrate 500 can be swiveled. That is, the substrate 500 on the hand 400 is transported to a desired position by the expansion and contraction operation and the turning operation.

By the way, in the recent manufacturing apparatus, a process of heating the substrate to several hundred degrees (500 to 600 ° C.) may be performed in the manufacturing process, and the horizontal articulated robot often carries such a high-temperature substrate. ing. In particular, since the step of raising the substrate temperature to several hundred degrees is often performed in a vacuum chamber in a reduced pressure state, the horizontal articulated robot is installed in the vacuum chamber and carries a high-temperature substrate. The hand 400 for directly mounting the board has a simple flat plate shape as compared with other parts, and can be formed of ceramics. The hand 400 itself has a problem in temperature even if a high-temperature board is directly mounted. In addition, since the thermal conductivity is relatively low, the heat of the substrate is not rapidly transferred to the first arm 100 and the second arm 200. On the other hand, the base material forming the casings (cases) of the first arm 100 and the second arm 200 is forced to have a complicated shape in order to accommodate a transmission mechanism and the like, and therefore aluminum is mainly used. It is easily deformed by heat.
When transporting a high-temperature substrate in such a situation, the first arm 100 and the second arm 200 are suddenly thermally deformed by radiant heat from the high-temperature substrate, causing a problem that the substrate cannot be transported properly. I came. That is, the horizontal articulated robot often frequently forms a stop posture as shown in FIG. 4A during the above-described expansion and contraction operation. That is, the high temperature substrate 500 mounted on the first hand 400 a forms a posture that is in a state of being very close to the upper surface of the second arm 200. In such a posture, the upper surface of the second arm 200 is particularly strongly subjected to the radiant heat of the high-temperature substrate. At this time, a rapid temperature change due to radiant heat occurs particularly in the second arm cover 214. As a result, the second arm cover 214 suddenly thermally expands, but the second arm case 201 has a temperature difference from the cover, so that the second arm cover 201 is thermally expanded as shown in FIG. The case 201 is deformed. That is, it becomes a phenomenon like a bimetal, and the second arm 200 is deformed. As a result, the substrate transfer accuracy deteriorates, and the thermal deformation of the second arm 200 causes the lower surface of the second arm case 201 and the cover of the first arm 100 to interfere, causing the horizontal articulated robot to become inoperable. There is.
In order to suppress deformation due to thermal expansion of the cover, it may be possible to use a material with a relatively small coefficient of thermal expansion, such as ceramics used in the hand, but ceramics are expensive and have the property of being easily broken (brittle). ing. In particular, when a brittle material such as ceramics is used for the arm cover that is frequently opened and closed during maintenance, there is a problem that the arm cover is easily broken.
The present invention has been made in view of such a problem, while maintaining an arm posture close to that when transporting a normal temperature substrate without deforming the arm as much as possible even when subjected to radiant heat of a high temperature substrate, An object of the present invention is to provide a horizontal articulated robot capable of realizing highly accurate substrate conveyance.

In order to solve the above problem, the present invention is configured as follows.
The invention according to claim 1 is provided at a hand on which a substrate can be mounted, a plurality of arms rotatably connected to each other in the horizontal direction, and supporting the hands at the distal ends, and base ends of the plurality of arms. A drive unit that rotates the plurality of arms, and the arm covers a transmission mechanism that transmits a rotation operation from the drive unit, an arm case that houses the transmission mechanism, and the transmission mechanism. A horizontal articulated robot configured by an arm cover mounted on an upper surface of the arm case, wherein the arm cover includes a plurality of arm covers divided in a plurality in a direction in which the arm case extends. This is a horizontal articulated robot.
According to a second aspect of the present invention, in the portions adjacent to each other in the plurality of arm covers, a horizontal gap is formed in a portion facing in the horizontal direction. It is an articulated robot.
According to a third aspect of the present invention, the gap spaced apart in the horizontal direction has a distance that prevents the plurality of arm covers from contacting each other even when the arm covers are heated and expanded by radiant heat of the substrate. The horizontal articulated robot according to claim 2, wherein the robot is a horizontal articulated robot.
The invention according to claim 4 is the horizontal articulated robot according to claim 2, wherein the portions adjacent to each other are formed so as to overlap each other when viewed from above.
The invention according to claim 5 is the horizontal articulated robot according to claim 4, wherein a gap that is vertically separated is formed in the overlapping portion in the vertically opposed portion. It is.
According to a sixth aspect of the present invention, the plurality of arms includes a first arm whose base end is rotatably connected to the drive unit, and a base end rotatably connected to the upper end of the first arm. A second arm and a third arm rotatably connected to the other end of the second arm to fix the hand, and only the arm cover of the second arm extends the second arm. The horizontal articulated robot according to claim 1, wherein the robot is divided into a plurality of parts in the existing direction.
According to a seventh aspect of the present invention, the hand is composed of a first hand and a second hand having the same shape, and the first hand and the second hand are opposed to each other by 180 ° at the rotation center of the third arm. The horizontal articulated robot according to claim 6, wherein the horizontal articulated robot is provided.
According to an eighth aspect of the present invention, there is provided a manufacturing apparatus comprising the horizontal articulated robot according to any one of the first to seventh aspects.

  As mentioned above, according to this invention, while being able to suppress the influence by the rapid thermal expansion of the arm cover by the radiant heat from a high temperature board | substrate, it can suppress that the dust generation from the transmission mechanism inside an arm disperses outside an arm. . Therefore, it is possible to configure a horizontal articulated robot that can suppress a change in the posture of the arm as much as possible and can perform highly accurate and clean substrate transfer.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 3 is a side sectional view of the arm portion of the horizontal articulated robot of the present invention.
In FIG. 1, reference numeral 100 denotes a first arm 100 that is rotated by the drive unit 1. The first arm 100 includes a first arm case 101 formed in a case shape, a first belt 111, a first pulley 112, a second pulley 113, and a first arm cover 114 housed therein. Has been. The lower surface of the base end side of the first arm case 101 is connected to the first drive shaft 1a of the drive unit 1, and the first arm case 101 rotates by the rotation of the first drive shaft 1a. A first pulley 112 is connected to the second drive shaft 1b inside the base end side of the first arm case 101, and rotates by the rotation of the second drive shaft 1b. A second pulley 113 is provided inside the distal end side of the first arm case 101 so as to be rotatable with respect to the first arm case 101. A first belt 111 is wound between the second pulley 113 and the first pulley 112, and the rotational force of the second drive shaft 1b is transmitted. A first arm cover 114 is fixed to the first arm case 101 so as to cover the first pulley 112, the first belt 111, and the second pulley 113.
The second arm 200 includes a second arm case 201 formed in a case shape, a third pulley 212, a second belt 211, a fourth pulley 213 accommodated therein, and a second arm cover 214. Has been. The lower surface of the base end side of the second arm case 201 is connected to the second pulley 113, and the second arm case 201 rotates as the second pulley 113 rotates. A third pulley 212 is fixed to a fixed shaft erected from the first arm case 101 inside the base end side of the second arm case 201. A fourth pulley 213 is provided inside the distal end side of the second arm case 201 so as to be rotatable with respect to the second arm case 201. A second belt 211 is wound between the third pulley 212 and the fourth pulley 213. A second arm cover 214 is fixed to the second arm case 201 so as to cover the third pulley 212, the second belt 211, and the fourth pulley 213.
The third arm 300 is fixed to the upper part of the fourth pulley 213, and the hand 400 is fixed to the third arm 300. The hand 400 is composed of the first hand 400a and the second hand 400b as described in the prior art.
Note that one or more idlers may be installed inside the first arm case 101 and the second arm case 201 for adjusting the tension of the first belt 111 and the second belt 211.

Hereinafter, a structure that suppresses thermal deformation of the arm in particular will be described. FIG. 1 shows a top view of a horizontal articulated robot according to the present invention. As shown in FIG. 1, in the present invention, the second arm cover 214 of the second arm 200 described above is constituted by a plurality of divisions.
FIG. 2A is a view of only the second arm 200 as viewed from above. The cover fixing screw 215 is a screw that fixes each cover of the second arm cover 214 to the second arm case 201. As shown in the figure, in this embodiment, the second arm cover 214 is divided into a total of six covers as 214a to f. These covers are formed of aluminum similar to the first arm case 101 and the second arm case 201, and each cover is made of the same material. In particular, substantially half of the base end side in the extending direction of the second arm cover 214 is divided into a large number such as 214 a to 214 d in the extending direction of the second arm 200. The number of the divided parts is appropriately changed depending on the length of the second arm 200 in the extending direction. As described above, when the horizontal articulated robot extends the third arm 300 and the hand 400, the first hand is used. It is optimal to place it at a position very close to the hot substrate 500 on 400a in the height and horizontal directions. However, dividing the arm cover reduces the strength from the viewpoint of maintaining the strength of the arm. In the present embodiment, by providing the divided portion only at the position where the second arm case 201 is closest to the substrate 500, the strength of the arm is prevented from being lowered.
FIG. 2B shows the second arm cover 214 as viewed from the side. As shown in the figure, each of the divided second arm covers 214 has a portion that overlaps with the adjacent cover at the end in the direction in which the second arm 200 extends (the direction of the arrow in the figure). Has been. The overlapping portion is formed so that the inside of the second arm case 201 cannot be seen when the second arm cover 214 is viewed from above. That is, the step on the tip side of the second arm 200 of the second arm cover 214a is provided with a step that is lowered by one step from the top surface, and the side of the base end side of the second arm 200 of the second arm cover 214b is provided on this step. Are provided so that a part of them overlap. On the other hand, a part of the side on the distal end side of the second arm 200 of the second arm cover 214b is provided with a step that is lowered by one step from the upper surface, and the side on the proximal end side of the second arm 200 of the second arm cover 214c. Are provided so that a part of them overlap. Similarly, the second arm cover 214c and the second arm cover 214d and thereafter are formed with overlapping portions.
In the overlapping portion, a horizontal gap 216 is formed in a portion where the covers are opposed to each other in the horizontal direction. The horizontal gap 216 is a gap that does not come into contact with each other even when the covers expand at high temperatures. That is, a horizontal gap 216 is formed in which the covers do not come into contact with each other even when the maximum temperature at which the covers are heated by the heat of the substrate 500 conveyed by the robot.
As described above, when the cover of the second arm cover 214 that is particularly greatly affected by the radiation of the high-temperature substrate is divided into small portions and the horizontal gaps 216 are formed in the portions facing each other in the horizontal direction, the temperature becomes high due to radiant heat. Even if each cover expands and extends in the extending direction of the second arm 200, the horizontal gap 216 only becomes narrow, and the force of thermal deformation does not act on the second arm case 201 as in the prior art. Therefore, it is possible to minimize the change in the arm posture due to the deformation of the cover. As a result, highly accurate conveyance can be continued.
Further, by forming each cover so as to be folded over when viewed from above, dust generated from a transmission mechanism such as a pulley or a belt can be prevented from scattering outside the arm.

  The above-described overlapping portions may be formed as shown in (c) to (g) of FIG. In (c), the vertical gap 217 is also formed in the portion that overlaps in the vertical direction. (D), (e) shows a case where one of the adjacent covers is formed thicker than the other, there is no step on the other, and only one has a step that overlaps the other. In (f) and (g), in each of the cases (d) and (e), as shown in (c), a vertical gap 217 is also formed in a portion that overlaps in the vertically overlapping portion. Shows the case.

  As described above, in the present invention, the second arm cover 214 that is particularly affected by the radiant heat from the substrate is divided in the second arm 200, and the structure in which the inside of the arm is not directly visible from the upper surface of the arm is folded. By forming it, it is possible to suppress arm deformation and posture change due to thermal expansion, and to suppress dust scattering from the mechanism inside the arm to the outside. Also, the arm cover can be formed of a material having a large thermal expansion coefficient, such as aluminum (or aluminum alloy), and the arm can be formed at low cost.

  The form of the transmission mechanism, the number of arms, the application location of the divided portion, and the number of divisions are not limited to the above embodiment. For example, the transmission mechanism may be a gear or a link. Further, for example, regarding the number of arms, an arm similar to the second arm is further provided between the second arm and the third arm, and the present invention can be applied to the cover of the third arm. Good. Further, for example, the application portion of the divided portion can be applied to the first arm cover 114.

The top view which shows the horizontal articulated robot of this invention The figure which shows the 2nd arm of the horizontal articulated robot of this invention Side sectional view of the arm portion of the horizontal articulated robot of the present invention A diagram showing a conventional horizontal articulated robot Side view of arm showing deformation of arm by heat

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Drive part 1a 1st drive shaft 1b 2nd drive shaft

100 1st arm 101 1st arm case 111 1st belt 112 1st pulley 113 2nd pulley 114 1st arm cover

200 Second arm 201 Second arm case 211 Second belt 212 Third pulley 213 Fourth pulley 214 Second arm cover 215 Cover fixing screw 216 Horizontal gap 217 Vertical gap

300 3rd arm

400 hand 400a first hand 400b second hand

500 substrates

Claims (8)

A hand on which a substrate can be mounted, a plurality of arms that are rotatably connected to each other in the horizontal direction and that support the hands at their tips, and a drive that is provided at the base end of the plurality of arms and rotates the plurality of arms And comprising
The arm includes a transmission mechanism that transmits a rotation operation from the drive unit, an arm case that houses the transmission mechanism, and an arm cover that is mounted on the upper surface of the arm case so as to cover the transmission mechanism. In a horizontal articulated robot,
The horizontal articulated robot according to claim 1, wherein the arm cover includes a plurality of arm covers divided in a plurality in a direction in which the arm case extends.   2. The horizontal articulated robot according to claim 1, wherein in the portions adjacent to each other, a gap that is horizontally spaced is formed in a portion that is opposed in the horizontal direction.   The gap spaced apart in the horizontal direction has a distance such that the plurality of arm covers do not come into contact with each other even when the arm covers are heated and expanded by radiant heat of the substrate. Item 3. The articulated horizontal robot according to item 2.   3. The horizontal articulated robot according to claim 2, wherein the adjacent portions are formed so as to overlap each other when viewed from above.   5. The horizontal articulated robot according to claim 4, wherein a gap that is spaced apart in the vertical direction is further formed in a portion that is opposed in the vertical direction in the overlapping portion. The plurality of arms includes a first arm having a base end rotatably connected to the drive unit, a second arm having a base end rotatably connected to a top end of the first arm, and the second arm. A third arm that is rotatably connected to the other end of the head and fixes the hand.
The horizontal articulated robot according to claim 1, wherein only the arm cover of the second arm is divided into a plurality of parts in a direction in which the second arm extends.   The hand is composed of a first hand and a second hand having the same shape, and the first hand and the second hand are provided so as to face each other at 180 ° at the rotation center of the third arm. The horizontal articulated robot according to claim 6. A manufacturing apparatus comprising the horizontal articulated robot according to claim 1.

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