KR20070015166A - Split assembly robotic arm - Google Patents

Abstract

A robotic arm assembly (101) is provided which comprises a hub (103), a first arm segment (105) which is attached to the hub, and a second arm segment (107) which is attached to the first arm segment such that said second arm segment can rotate at least partially about its longitudinal axis. ® KIPO & WIPO 2007

Description

Robot arm {SPLIT ASSEMBLY ROBOTIC ARM}

The present invention relates to a robot arm, and more particularly, to a joint assembly for a robot arm of the type used in the wafer processing equipment.

Semiconductor processing systems use a cluster tool that combines multiple processing chambers into one to perform a series of processing steps without removing the substrate in a highly controlled processing environment. These processing chambers include an exhaust chamber, a substrate pretreatment chamber, a cooling chamber, a transfer chamber, a chemical vacuum deposition chamber, a physical vacuum deposition chamber, and an etching chamber. Integrating these chambers into cluster tools, and the operating environment and variables in which the chambers are operated, are chosen to form a specific structure using a particular process.

Once a cluster tool is set up with processing chambers and ancillary equipment to perform a certain process, a large number of substrates are processed, one by one, through a series of processing chambers or processing steps. This method and sequence is programmed into a microprocessor controller that controls and monitors the processing of each substrate through the cluster tool. Once the entire wafer cassette has been successfully processed in the cluster tool, the cassette is transferred to another cluster tool, or to another device such as a mechanochemical polishing machine.

One example of the fabrication system described above is shown in FIGS. 1 and 2 as the cluster tool introduced in US Pat. No. 6,222,337 to Kroeker. The magnetically coupled robot introduced here has a robotic arm with a frog-legged structure suitable for providing both radial-rotational movements of the robot blade in a fixed plane. With proper combination of radial and rotational motion, the substrate can be picked up from one place within the cluster tool and transported to another. For example, a robotic arm can be used to move a substrate from one processing chamber to an adjacent processing chamber.

1 is a schematic diagram of Kroeker's integrated cluster tool 10. The substrate is inserted into or removed from the cluster tool 10 through a cassette loadlock 12. A robot 14 with a blade 17 is positioned inside the cluster tool 10 to transfer the substrate between the process chambers. Such a treatment chamber includes a load lock 12, an exhaust chamber 20, a clean chamber 24, a PVD TiN treatment chamber 22, a cooling chamber 26, and the like. The robot blade 17 is in the retracted position and can rotate freely inside the processing chamber 18 at this position.

The second robot 28 in the transfer chamber 30 is for transferring substrates between various processing chambers, such as the cooling chamber 26, the clean chamber 24, the CVD Al processing chamber (not shown) and the PVD AlCu processing chamber (not shown). . The processing chambers shown in FIG. 1 are designed to form an integrated processing system capable of performing both CVD and PVD processing in one cluster tool. The microprocessor controller 29 for controlling the processing sequence, the state inside the cluster tool, and the operation of the robots 14 and 28 is provided.

Figure 2 is a schematic diagram of the magnetic coupling robot of Figure 1 showing a stretched state. The robot 14 includes a first strut 81 securely connected to the first magnet clamp 80, and a second strut 82 securely connected to the second magnet clamp 80 ′. The third strut 83 is connected to the strut 81 via the pivot 84 and to the wafer blade 86 via the pivot 85. Fourth strut 87 is connected to strut 82 via pivot 88 and to wafer blade 86 via pivot 89. The structure of these struts 81-83, 87 and pivots 84, 85, 88, and 89 makes the shape of the "frog leg" in which the wafer blades 86 are connected to the magnetic clamps 80, 80 '.

When the magnetic clamps 80 and 80 'rotate in the same direction at the same angular velocity, the robot also rotates in the same direction and at the same speed about the x axis. When the magnetic clamps 80 and 80 'rotate opposite to each other at the same angular velocity, the robot 14 does not rotate and instead moves radially to the position 81'-89' indicated by the broken line by the wafer blade 86. Perform linear motion

The wafer 35 is placed on the wafer blade 86, and the wafer blade extends through the transfer slot 810 of the wall 811 of the processing chamber 32, and the wafer is inserted into or removed from the processing chamber 32. In the mode in which the magnetic clamps 80 and 80 'rotate in the same direction at the same speed, the robot rotates from one of the adjacent processing chambers 12, 20, 22, 24 and 26 to the other processing chamber to exchange wafers. In a mode in which both magnet clamps 80 and 80 'are reversely rotated at the same speed, the wafer blade is stretched into one processing chamber and then contracted. Proper combination of clamp rotations allows the robot to rotate properly around the x-axis while stretching the wafer blades.

In order to keep the wafer blade 86 radially extending from the axis of rotation x, it is necessary to use the locking mechanism between the pivots 85 and 89 to keep the rotation of each pivot the same and vice versa. The locking mechanism can take various designs. One example of a locking mechanism is to place gear pairs 92 and 93 that engage each other between pivots 85 and 89. The gears are loosely engaged to minimize particle generation by these gears. In order to eliminate the studs between the two gears due to loose engagement, connect a weak spring 94 between the point 95 of one gear to the point 96 of the other gear, until the gears are lightly contacted. Let the spring pull the gear (see Fig. 4).

Robots of the kind described in Kroeker's US Pat. No. 6,222,337 have many advantages, but also many disadvantages. In particular, this type of robot has excessive wear on the wrist joints (85 ', 89') and elbow joints (84 ', 88'). This can result in high maintenance costs and many downtimes during the manufacturing process. Therefore, there is a need for a robot having a reduced maintenance cost and less wear on the joints.

Summary of the Invention

According to the present invention, there is provided a hub, a first robot arm section connected to the hub, and a second robot arm section connected to the first robot arm section (via a pin or other suitable means) so as to rotate about the longitudinal axis. The robot arm provided is provided. The robot arm preferably has a frog leg shape, is connected to a hub, a third robot arm section pivotally connected to the second robot arm section, an end effector (to which the third robot arm section is connected), and a hub. And a fifth robot arm section connected to the fourth robot arm section so as to be rotatable about the fourth robot arm section. The robot arm further includes a sixth robot arm section pivotally connected to the fifth robot arm section, which is connected to the end effector. Preferably, the fifth and sixth robot arm sections are respectively connected to both sides of the end effector through the wrist joint.

According to the present invention, a herb; Lower arm connected to the hub; An upper arm pivotally connected to the lower arm; And an end effector connected to the upper arm, and a robot arm including first and second sections in which the lower arm is rotatably connected to each other. Here, the first robot arm section is rotatably connected to the second robot arm section through the pin.

In addition, according to the present invention, a herb; A first robot arm section connected to the hub; And a robot arm section having a second robot arm section connected to the first robot arm section to move relative to the first robot arm section in a manner to relieve stress of the robot arm.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

1 is a plan view of a cluster tool with a robotic wafer processing system;

2 is a plan view showing a stretched state of the robot arm of the robot shown in FIG.

3 is a plan view of the robot arm wrist joint shown in FIG.

4 is a plan view showing a stretch state of a conventional robot arm;

5 is a schematic cross-sectional view of the robot arm according to the present invention.

The above conditions are solved by the apparatus and method described below. In particular, in the conventional robot arm of the type described in Figs. 1-4, the hub assembly is displaced from its parts and the lower arm is rolled on the rotating hub shaft. For example, in the conventional robot arm, three concentric rings are included in the hub to which the robot arm is connected. The upper and lower rings have bearings in them and are connected to the robot arm, and the middle ring contains one or more rare earth magnets to drive the magnetic coupling. In use, these rings perform the above-described roll movement with their centers displaced.

In the frog-leg configuration shown in FIGS. 1-4, this roll movement is transmitted along the beam of the forearm, with the forearm not parallel to the latter half of the frog's leg. In this state, the wrists, elbows and hub assemblies are stressed, causing abnormal movements in the z direction (vertical to the plane in which the robot arms stretch and contract) and wear quickly when the robot arms move. The apparatus and method of the present invention provide a means of compensating for this roll movement, thereby eliminating premature wear and ensuring proper movement of the robot arm.

5 shows an example of the lower part of the robot arm constructed in accordance with the present invention. For the sake of explanation, the detailed configuration of the robot arm is omitted. The robot arm 101 includes a hub 103, a first robot arm 105 attached to a rotating ring in the hub, and a second robot arm section 107 connected to the first robot arm section via a pin 109. Equipped.

These first and second sections 105 and 107 are quickly coupled to each other through bolts 111 coupled to screw holes (not shown) formed in the second section 107. Since the bolt hole formed in the first section is sufficiently larger than the bolt, the first section can be slightly rotated around the axis of the pin 109 when the bolt is fully released to roll the robot arm. Preferably, this rotation is in the ± 2 ° range, which is small but sufficient to reduce the stress that will develop on the wrist-elbow joint. Therefore, when the lower arm is composed of two parts as shown in Figure 5, it is possible to rotate to maintain the balance of the entire robot arm while compensating for the center shift rolling.

Although described in FIG. 5 is a specific means of compensating roll motion and added stress, this object can be achieved by various other means as will be appreciated by those skilled in the art. The first and second sections of FIG. 5 may also be connected via a bearing, in which case these sections may rotate to be limited to each other. These various means are also within the scope of the present invention.

Claims (13)

Herb; A first robot arm section connected to the hub; And And a second robot arm section connected to the first robot arm section so as to rotate about a longitudinal axis. The robotic arm of claim 1, further comprising a third robotic arm section pivotally connected to the second robotic arm section. 3. The robotic arm of claim 2, further comprising an end effector, wherein said third robotic arm section is connected to said end effector. The method of claim 3, A fourth robot arm section connected to the hub; And And a fifth robot arm section connected to the fourth robot arm section so as to be rotatable about a vertical axis. The robotic arm of claim 4, further comprising a sixth robot arm section pivotally connected to the fifth robot arm section, wherein the sixth robot arm section is connected to the end effector. The robotic arm of claim 5, wherein the fifth and sixth robot arm sections are respectively connected to both ends of the end effector. The robotic arm of claim 1, wherein the third robotic arm section is connected to an end effector through a wrist joint. The robotic arm of claim 1, wherein the second robot arm section is rotatably connected to the first robot arm section through a pin. The robotic arm of claim 1, wherein the robotic arm is designed in the shape of a frog leg. The method of claim 1, A fourth robot arm section connected to the hub; And And a fifth robot arm section connected to the fourth robot arm section so as to rotate about the longitudinal axis. Herb; A lower arm connected to the hub; An upper arm pivotally connected to the lower arm; And And an end effector connected to the upper arm. Robot arm, characterized in that the lower arm comprises a first, second intervals rotatably connected to each other. The robotic arm of claim 11, wherein the first robot arm section is rotatably connected to the second robot arm section through a pin. Herb; A first robot arm section connected to the hub; And And a second robot arm section connected to the first robot arm section so as to move with respect to the first robot arm section in a manner to reduce the stress of the robot arm.

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