Wafer transfer system based on R-θ configuration robot and assembly method thereof

Abstract

The present invention relates to the field of semiconductor manufacturing equipment, and in particular to a wafer transfer system based on an R-θ configuration robot and an assembly method thereof. It comprises a robot and a wafer chamber. The robot comprises a main shaft, the main shaft is connected to an arm mechanism, the arm mechanism comprises an arm of a serial structure, any one of the arms is directly or transmission-connected to the main shaft; the wafer chamber is provided for wafer placement and is arranged in a plurality around the robot, and the arms are driven by the main shaft to perform interpolation movements in and out of the wafer chamber; the arm mechanism is arranged in a plurality, and the plurality of arm mechanisms are rotatably connected to the execution end of the main shaft along the same vertical axis. By arranging two independent and simultaneously movable arm mechanisms on the same vertical axis of the main shaft, the system can perform the placement and take-and-place operations of two wafers in parallel. Compared with the traditional single-arm system, the time required to process the same number of wafers is greatly shortened, and the system throughput is significantly improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor manufacturing equipment, and in particular to a wafer transmission system based on an R-θ configuration robot and an assembly method thereof. Background Art

[0002] In semiconductor manufacturing, wafer transfer robots based on an R-θ configuration are widely used for efficient and precise wafer handling between processing equipment and storage compartments. Traditional systems of this type typically consist of a multi-jointed arm mechanism driven by a rotating spindle and multiple wafer storage compartments arranged around the robot. Driven by the spindle, the arm mechanism performs wafer placement operations through interpolated motion of its joints.

[0003] However, the existing single-arm mechanism design has the following problems:

[0004] 1. A single arm can only perform pick-and-place operations on one wafer chamber at a time. When multiple chambers need to be processed, they must be executed sequentially, limiting the overall throughput of the system.

[0005] 2. The arm's structural design often limits its service range. This is especially true when a set of parallel chambers are closely spaced, and the arm attempts to enter chambers on different sides. For example, when the left arm attempts to enter the right chamber, the arm joint or end effector is very likely to physically collide with the door or structure of the adjacent chamber, resulting in inability to enter some chambers. This requires the arm's range of motion to match the layout of the wafer chambers.

[0006] 3. When trying to increase the number of arms to improve efficiency, traditional designs are prone to interference in inter-arm motion, and will increase the complexity, weight and inertia of the system, placing higher demands on drive and control. Summary of the Invention

[0007] The purpose of the present invention is to provide a wafer transfer system based on an R-θ configuration robot and an assembly method thereof, so as to solve the problem of low handling efficiency of wafer manipulators in the prior art.

[0008] The technical solution of the present invention is: a wafer transfer system based on an R-θ configuration robot, comprising:

[0009] The robot comprises a main shaft, the main shaft being connected to an arm mechanism, the arm mechanism comprising arms in a serial structure, any one of the arms being directly or transmission-connected to the main shaft;

[0010] The wafer chamber is used for wafer placement and is provided with a plurality of robots around it. The arms are driven by the main shaft to perform interpolation movements in and out of the wafer chamber;

[0011] The arm mechanisms are provided in plurality, and the plurality of arm mechanisms are rotationally connected to the execution end of the main shaft along the same vertical axis.

[0012] Preferably, the arm comprises at least a first arm, a second arm and a third arm: one end of the first arm is rotatably connected to the main shaft; one end of the second arm is rotatably connected to the end of the first arm away from the main shaft; one end of the third arm is rotatably connected to the end of the second arm away from the first arm;

[0013] The first arms of the plurality of arm mechanisms are stacked, and one of the arm mechanisms has a heightening pad, so that the third arms of the plurality of arm mechanisms are at the same height.

[0014] Preferably, the second arm has a length dimension shorter than that of the first arm, and when the pair of first arms are in an open state, the pair of second arms have projections of non-overlapping motion paths on the same horizontal plane.

[0015] Preferably, it is set that: the central axis of the third arm is the first axis; the circle with the midpoint of the main axis as the center and the difference in length between the first arm and the second arm as the radius is the reference circle; the connecting end of the second arm and the third arm forms an interpolation line tangent to the reference circle during interpolation movement; and when the end of the third arm away from the second arm enters the wafer removal position corresponding to the wafer chamber, the interpolation line forms a deflection angle with the first axis;

[0016] The deflection angle enables any arm mechanism to perform interpolation actions on any wafer chamber.

[0017] Preferably, the distance between the film-taking position and the main axis is set to R1; the distance between the two rotating ends of the first arm connected to the main axis and the second arm is L1; the distance between the two rotating ends of the second arm connected to the first arm and the third arm is L2; ​​the distance between the rotating connection end of the third arm connected to the second arm and the film-taking center is L3; the deflection angle is Phi; Phi = arcsin((L1-L2) / (R1-L3)).

[0018] Preferably, the main shaft is provided with a first drive shaft and a second drive shaft corresponding to any arm mechanism, and the first drive shaft and the second drive shaft have the same axis along the vertical direction; the first drive shaft can drive the first arm to rotate around the axis of the first drive shaft, and the second drive shaft is connected to the second arm and the third arm in sequence through a transmission mechanism.

[0019] Preferably, the transmission mechanism includes a first pulley, which is coaxially fixed with the second drive shaft and connected to the second pulley through a synchronous belt, the second pulley is arranged at the end of the first arm away from the main shaft, and has a third pulley coaxial with the second pulley and arranged at the end of the second arm connected to the first arm, the third pulley is connected to the fourth pulley through a synchronous belt, and the fourth pulley is arranged at the rotating connection end of the second arm and the third arm and fixed to the third arm.

[0020] Preferably, the third arm is formed with a bend at one end close to the second arm, so that the third arm is constructed into a third main arm and a third auxiliary arm, and the third main arm and the third auxiliary arm have a fixed relative position;

[0021] The first axis serves as the central axis of the third main arm, and the central axis of the third auxiliary arm coincides with the interpolation line in the film-taking position.

[0022] Preferably, the third auxiliary arm has at least one side wall parallel to its central axis, and the side wall is constructed as an assembly positioning surface;

[0023] A positioning fixture is provided, wherein the positioning fixture has a positioning end surface capable of abutting against an assembly positioning surface. When a pair of assembly positioning surfaces abut against the positioning end surface, a pair of the third main arms (131) form an included angle of 2phi.

[0024] An assembly method for a wafer transfer system based on an R-θ configuration robot comprises the following steps:

[0025] Step 1: align the central axes of the pair of first arms, and keep the non-connected ends of the pair of first arms and the main shaft away from each other;

[0026] Step 2: align the central axes of the pair of second arms, and bring the non-connected ends of the pair of second arms and the first arm closer to each other;

[0027] Step 3: Place the positioning fixture and adjust the third arm so that the assembly positioning surfaces of the pair of third auxiliary arms abut against the positioning end surfaces on both sides of the positioning fixture, thereby forming an angle of 2phi between the pair of third main arms.

[0028] Compared with the prior art, the advantages of the present invention are:

[0029] (1) By setting up two independent and simultaneously movable arm mechanisms on the same vertical axis of the spindle, the system can perform two wafer pick-and-place operations in parallel. Compared with traditional single-arm systems, the time required to process the same number of wafers is greatly shortened, and the system throughput is significantly improved.

[0030] (2) The design of the second arm being shorter than the first arm, combined with the open state of the first arm, ensures that the two second arms can perform 360-degree non-interference rotation on the same horizontal plane, and their motion path projections do not overlap.

[0031] (3) By defining a reference circle (radius |L1-L2|) and setting the interpolation line formed by the connection between the second and third arms and the first axis (the central axis of the third arm) to form a specific deflection angle Phi (Phi = arcsin((L1-L2) / (R1-L3))) when the end of the third arm reaches the wafer pickup position, this design fundamentally solves the collision problem when the arm enters the wafer chamber at different positions. The existence of the deflection angle ensures that the arm mechanism can enter any position safely and without collision, including interpolation actions on wafer chambers located on "non-same sides" where collisions are prone to occur in traditional designs, eliminating service blind spots.

[0032] (4) All arm rotations are driven directly by a drive shaft or a synchronous pulley mechanism, with the power ultimately coming from the first and second coaxial drive shafts on the main shaft. This design avoids installing independent and bulky motors at each joint, significantly reducing the overall weight and moment of inertia of the arm mechanism. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0034] Figure 1 This is a structural diagram of the wafer transfer system based on the R-θ configuration robot according to the present invention;

[0035] Figure 2 This is a structural diagram of the arm mechanism of the present invention;

[0036] Figure 3 Schematic diagram of one of the wafer retrieval methods of the wafer transfer system based on the R-θ configuration robot of the present invention;

[0037] Figure 4 This is a schematic diagram of the wafer transfer system based on the R-θ configuration robot according to the present invention completing wafer retrieval;

[0038] Figure 5 Schematic diagram of other wafer retrieval methods of the wafer transfer system based on the R-θ configuration robot according to the present invention;

[0039] Figure 6 This is a structural diagram of the transmission mechanism of the present invention;

[0040] Figure 7 for Figure 1 Enlarged view of point B in the middle;

[0041] Figure 8It is a structural diagram of some embodiments of the present invention;

[0042] Figure 9 for Figure 8 Enlarged view of point A in the middle;

[0043] Figure 10 This is a structural diagram of the third arm in some embodiments of the present invention;

[0044] Figure 11 This is a schematic diagram of the interference between the arm and the hatch in the prior art of the present invention;

[0045] Among them: 1. Arm mechanism, 11. First arm, 12. Second arm, 13. Third arm, 131. Third main arm, 132. Third auxiliary arm, 133. Assembly positioning surface, 2. Wafer chamber, 3. Raising pad, 4. First axis, 5. Reference circle, 6. Interpolation line, 7. Transmission mechanism, 71. First pulley, 72. Second pulley, 73. Third pulley, 74. Fourth pulley, 8. Positioning fixture, 100. Wafer. DETAILED DESCRIPTION

[0046] The terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Therefore, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, unless otherwise specified, "plurality" means two or more, unless otherwise specified.

[0047] In this application, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature may include the first feature being directly above or obliquely above the second feature, or may simply mean that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature may include the first feature being directly below or obliquely below the second feature, or may simply mean that the first feature is lower in level than the second feature.

[0048] The present invention is further described in detail below with reference to specific embodiments:

[0049] like Figure 1 As shown, the wafer 100 transmission system based on the R-θ configuration robot includes a robot for taking and placing the wafer 100 and a wafer chamber 2 for storing the wafer 100.

[0050] Among them, the robot includes a main shaft, which is arranged in a vertical direction. The top of the main shaft serves as the execution end and is connected to an arm mechanism 1. The arm mechanism 1 includes multiple arms in a series structure, and any one of the multiple arms is directly or transmission-connected to the main shaft. The wafer 100 chambers are arranged around the robot in multiple groups, wherein the spacing between at least one group of wafer 100 chambers is different from the spacing between other groups of wafer 100 chambers. Driven by the main shaft, the arm performs interpolation movements in and out of the wafer chamber 2 to pick up and place the wafer 100.

[0051] In order to improve the efficiency of wafer 100 placement, two arm mechanisms 1 are provided in the present application, and the two arm mechanisms 1 are rotatably connected to the execution end of the main shaft along the same vertical axis, so that each arm mechanism 1 can perform interpolation actions of wafer 100 placement at the same time.

[0052] Specific, combined Figure 2 As shown, the arm comprises at least a first arm 11, a second arm 12, and a third arm 13. One end of the first arm 11 is rotatably connected to the main shaft; one end of the second arm 12 is rotatably connected to the end of the first arm 11 away from the main shaft; and one end of the third arm 13 is rotatably connected to the end of the second arm 12 away from the first arm 11.

[0053] The first arms 11 in the two arm mechanisms 1 are stacked, so in this embodiment, a heightening pad 3 is provided at one end of the second arm 12 connected to the first arm 11. The heightening pad 3 enables the two third arms 13 for taking and placing wafers 100 to be at the same height.

[0054] Furthermore, in this embodiment, the second arm 12 has a length dimension shorter than that of the first arm 11. This configuration allows any second arm 12 to rotate 360 ​​degrees around its rotational connection end with the first arm 11 when the pair of first arms 11 are in an open state, that is, when the distance between the ends of the pair of first arms 11 away from the main axis is the largest. The pair of second arms 12 have projections of motion paths that do not overlap on the same horizontal plane, that is, the motion of one second arm 12 does not interfere with the motion of another second arm 12. Figure 3-Figure 5 As shown, the two arm mechanisms 1 can simultaneously perform interpolation movements on two adjacent and parallel wafer chambers 2.

[0055] In the prior art, the same arm mechanism 1 can only perform interpolation on one of a set of parallel wafer chambers 2. Figure 11 For example, when the arm mechanism 1 on the left side performs the interpolation action of taking and placing the wafer 100 in a group of wafer chambers 2 located above it, it can only enter the wafer chamber 2 on the same side (left side) as it. When the arm mechanism 1 tries to enter the wafer chamber 2 on its right side, its arm will collide with the door of the wafer chamber 2 on the right side.

[0056] To solve this problem, the following parameters are set in this application:

[0057] Combine Figure 1 、 Figure 2 and Figure 7 As shown, the central axis of the third arm 13 is the first axis 4;

[0058] A circle with the midpoint of the main axis as the center and the difference between the lengths of the first arm 11 and the second arm 12 as the radius is the reference circle 5;

[0059] The connecting end of the second arm 12 and the third arm 13 forms an interpolation line 6 tangent to the reference circle 5 during the interpolation movement; and when the end of the third arm 13 moves away from the second arm 12 and enters the wafer picking position corresponding to the wafer chamber 2, the interpolation line 6 forms a deflection angle with the first axis 4. The existence of this deflection angle will enable any arm mechanism 1 to perform interpolation actions on the wafer chamber 2 at any position.

[0060] Specifically, the distance between the film-taking position and the main axis is set to R1; the distance between the two rotating ends of the first arm 11 connected to the main axis and the second arm 12 is L1; the distance between the two rotating ends of the second arm 12 connected to the first arm 11 and the third arm 13 is L2; ​​the distance between the rotating connection end of the third arm 13 connected to the second arm 12 and the film-taking center is L3; the deflection angle is Phi; Phi = arcsin((L1-L2) / (R1-L3)).

[0061] In order to reduce the weight of the arm mechanism 1, the rotating connection ends of the first arm 11 and the second arm 12, as well as the rotating connection ends of the second arm 12 and the third arm 13, are all connected by transmission, and the power to drive them all comes from the main shaft. Specifically, the main shaft is provided with a first drive shaft and a second drive shaft corresponding to any arm mechanism 1, and the first drive shaft and the second drive shaft have the same axis in the vertical direction. The first drive shaft can drive the first arm 11 to rotate around the axis of the first drive shaft, and the second drive shaft is connected to the second arm 12 and the third arm 13 in sequence through the transmission mechanism 7.

[0062] Combine Figure 2 and Figure 6As shown, the transmission mechanism 7 includes a first pulley 71, which is coaxially fixed to the second drive shaft so that the second drive shaft can drive the first arm to operate. The first pulley 71 is connected to the second pulley 72 via a synchronous belt. The second pulley 72 is arranged at the end of the first arm 11 away from the main shaft, and has a third pulley 73 coaxial with the second pulley 72 and arranged at the end of the second arm 12 connected to the first arm 11. At the same time, the second pulley 72 is fixed to the second arm 12, thereby achieving the movement of the first arm 11 while driving the movement of the second arm 12. The third pulley 73 is coaxial with the second pulley 72 and fixed to the first arm 11. The third pulley 73 is connected to the fourth pulley 74 via a synchronous belt. The fourth pulley 74 is arranged at the rotation connection end between the second arm 12 and the third arm 13 and fixed to the third arm 13, thereby achieving the movement of the second arm 12 while driving the movement of the third arm 13.

[0063] Therefore, during the interpolation movement of the wafer chamber 2 by the robot, the movements of the first arm 11 , the second arm 12 , and the third arm 13 are all performed synchronously and are interrelated.

[0064] In this embodiment, if Figure 8-10 As shown, the third arm 13 is bent at one end close to the second arm 12, thereby being constructed into a third main arm 131 and a third auxiliary arm 132, and the third main arm 131 and the third auxiliary arm 132 have a fixed relative position. Among them, the first axis 4 serves as the central axis of the third main arm 131, and the central axis of the third auxiliary arm 132 coincides with the interpolation line 6 in the film-taking position. Furthermore, the third auxiliary arm 132 has at least one side wall parallel to its own central axis, and the side wall is constructed as an assembly positioning surface 133; when a pair of third arms 13 have the same orientation, the assembly positioning surfaces 133 on the third arms 13 are arranged relative to each other.

[0065] During the assembly process, starting from the main axis, each arm is gradually adjusted according to the connection relationship of each arm. This application adopts the following steps for assembly:

[0066] Step 1: Figure 8 、 Figure 9 As shown, the central axes of the pair of first arms 11 are aligned, and the non-connected ends of the pair of first arms 11 and the main shaft are away from each other.

[0067] Step 2: Align the central axes of the pair of second arms 12, and bring the non-connected ends of the pair of second arms 12 and the first arm 11 closer to each other; at this point, the central axes of the pair of first arms 11 and the pair of second arms 12 are all in the same plane passing through the central axis of the main shaft.

[0068] Step 3: Adjust the pair of third arms 13 so that the assembly positioning surface 133 of the third auxiliary arm 132 is perpendicular to the central axis of the first arm 11 or the second arm 12, so that an angle of 2phi is formed between the pair of third main arms. At this time, the pair of assembly positioning surfaces 133 are parallel to each other. Figure 8 、 Figure 9 For example, in an actual application scenario, in order to avoid motion interference between a pair of third arms, there is a distance between the assembly positioning surfaces 133 on the pair of third arms 13. In this case, in order to ensure the parallelism of the pair of assembly positioning surfaces 133, as shown in FIG. Figure 9 As shown, the present application is provided with a positioning fixture 8. The positioning fixture 8 having two parallel positioning end faces is placed between a pair of third arms 13, and the two assembly positioning surfaces 133 are fitted with a pair of parallel positioning end faces on the positioning fixture 8, thereby completing the assembly of the arm mechanism 1.

[0069] In the process of assembling traditional arms, in order to achieve reference positioning, pin holes are generally opened at corresponding positions on different arms and pins are used to pass through the pin holes on different arms, so that the corresponding arms form a preset angle to achieve assembly positioning. However, the opening of pin holes can easily form stress concentration points on the arms. Under long-term high-frequency movement, the edges of the pin holes may crack or even break due to fatigue stress. At the same time, each arm adopts an independent pin positioning method, and the assembly compatibility between the two is poor. During the positioning of the pin and the pin hole, if the matching accuracy of the pin and the pin hole is high, the pin hole will be subjected to excessive insertion and extraction force of the pin, causing damage, especially the inner wall of the pin hole. If the matching accuracy of the pin and the pin hole is low, the damage to the arm itself is small, but the assembly accuracy is lower. Furthermore, based on the high-precision requirements of wafer manipulators in the semiconductor industry, this application forms an assembly positioning surface 133 by structurally deforming the third arm 13, which better meets the needs of actual application scenarios, not only abandoning the limitation of the range of motion, but also improving the assembly accuracy.

[0070] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the content of the present invention and implement it accordingly, and they are not intended to limit the scope of protection of the present invention. For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes that fall within the meaning and scope of the equivalent elements of the claims are included in the present invention.

Claims

1. A wafer (100) transport system based on an R-θ configuration robot, characterized in that: include: A robot comprises a main shaft, wherein the main shaft is connected to an arm mechanism (1), wherein the arm mechanism (1) comprises arms of a serial structure, and any one of the arms is directly or transmission-connected to the main shaft; A wafer chamber (2) for placing and picking up wafers (100) and a plurality of robots arranged around the chamber, wherein the arms are driven by a main shaft to perform interpolation movements in and out of the wafer chamber (2); The arm mechanisms (1) are provided in plurality, and the plurality of arm mechanisms (1) are rotatably connected to the execution end of the main shaft along the same vertical axis; The arm comprises at least a first arm (11), a second arm (12) and a third arm (13); the central axis of the third arm (13) is set as the first axis (4); a circle with a radius equal to the difference between the lengths of the first arm (11) and the second arm (12) and the midpoint of the main axis as the center is a reference circle (5); the connecting end of the second arm (12) and the third arm (13) forms an interpolation line (6) tangent to the reference circle (5) during interpolation motion; and when the end of the third arm (13) away from the second arm (12) enters the wafer picking position of the corresponding wafer chamber (2), the interpolation line (6) forms a deflection angle with the first axis (4); the deflection angle enables any arm mechanism (1) to perform interpolation motion on any wafer chamber (2); The distance between the film-taking position and the main axis is set to R1; the distance between the two rotating ends of the first arm (11) connected to the main axis and the second arm (12) is L1; the distance between the two rotating ends of the second arm (12) connected to the first arm (11) and the third arm (13) is L2; ​​the distance between the rotating connection end of the third arm (13) connected to the second arm (12) and its film-taking center is L3; the deflection angle is Phi; Phi = arcsin((L1-L2) / (R1-L3)).

2. The wafer (100) transport system based on the R-θ configuration robot according to claim 1, characterized in that: One end of the first arm (11) is rotatably connected to the main shaft; one end of the second arm (12) is rotatably connected to the end of the first arm (11) away from the main shaft; one end of the third arm (13) is rotatably connected to the end of the second arm (12) away from the first arm (11); The first arms (11) in the plurality of arm mechanisms (1) are stacked, and one of the arm mechanisms (1) has a heightening pad (3), so that the third arms (13) in the plurality of arm mechanisms (1) are at the same height.

3. The wafer (100) transmission system based on the R-θ configuration robot according to claim 2, characterized in that: The second arms (12) have a length dimension shorter than that of the first arms (11), and when the pair of the first arms (11) are in an open state, the pair of the second arms (12) have projections of motion paths that do not overlap on the same horizontal plane.

4. The wafer (100) transmission system based on the R-θ configuration robot according to claim 1, characterized in that: The main shaft is provided with a first drive shaft and a second drive shaft corresponding to any arm mechanism (1), and the first drive shaft and the second drive shaft have the same axis in the vertical direction; the first drive shaft can drive the first arm (11) to rotate around the axis of the first drive shaft, and the second drive shaft is connected to the second arm (12) and the third arm (13) in sequence through the transmission mechanism (7).

5. The wafer (100) transport system based on the R-θ configuration robot according to claim 4, characterized in that: The transmission mechanism (7) includes a first pulley (71), the first pulley (71) is fixed coaxially with the second drive shaft and connected to the second pulley (72) through a synchronous belt, the second pulley (72) is arranged at the end of the first arm (11) away from the main shaft, and has a third pulley (73) coaxial with the second pulley (72) and arranged at the end of the second arm (12) connected to the first arm (11); at the same time, the second pulley (72) is connected to the second arm (12); the third pulley (73) is coaxial with the second pulley (72) and connected to the first arm (11); the third pulley (73) is connected to the fourth pulley (74) through a synchronous belt, and the fourth pulley (74) is arranged at the rotation connection end between the second arm (12) and the third arm (13) and fixed to the third arm (13).

6. The wafer (100) transport system based on the R-θ configuration robot according to claim 5, characterized in that, The third arm (13) is formed with a bend at one end close to the second arm (12), so that the third arm (13) is constructed into a third main arm (131) and a third auxiliary arm (132), and the third main arm (131) and the third auxiliary arm (132) have a fixed relative position; The first axis (4) serves as the central axis of the third main arm (131), and the central axis of the third auxiliary arm (132) coincides with the interpolation line (6) in the film-taking position.

7. The wafer (100) transport system based on the R-θ configuration robot according to claim 6, characterized in that, The third auxiliary arm (132) has at least one side wall parallel to its own central axis, and the side wall is constructed as an assembly positioning surface (133); A positioning jig (8) is provided, wherein the positioning jig (8) has a positioning end surface capable of abutting against an assembly positioning surface, and when a pair of assembly positioning surfaces abut against the positioning end surface, a pair of the third main arms (131) form an included angle of 2phi.

8. An assembly method for a wafer (100) transmission system based on an R-θ configuration robot according to any one of claims 1 to 7, characterized in that: The steps include: Step 1: aligning the central axes of the pair of first arms (11), and moving the non-connected ends of the pair of first arms (11) away from each other; Step 2: aligning the central axes of the pair of second arms (12) and bringing the non-connected ends of the pair of second arms (12) and the first arm (11) closer to each other; Step 3: Place the positioning fixture (8) and adjust the third arm (13) so that the assembly positioning surfaces (133) of the pair of third auxiliary arms (132) abut against the positioning end surfaces on both sides of the positioning fixture (8), thereby forming an angle of 2phi between the pair of third main arms (131).

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