Wafer conveying system and method of multi-hand box station mechanical arm
The multi-hand box station robot arm addresses particle impurity and mechanical stress issues by transferring multiple wafers efficiently, enhancing throughput and yield through optimized fork movements and spacing adjustments.
Patent Information
- Application Number
- CN202411344773.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-25
- Publication Date
- 2025-01-03
AI Technical Summary
Existing wafer transfer systems using high-speed robot arms suffer from particle impurity overflow and reduced part lifespan, limiting throughput and wafer yield due to increased mechanical stress.
A multi-hand box station robot arm with N forks (N≥2) transfers wafers between a wafer box and a transfer unit, enabling simultaneous handling of multiple wafers, adjusting fork movements to match wafer and transfer unit spacing, and allowing for individual or batch transfers.
Enhances wafer transfer efficiency by reducing movement distance and mechanical stress, improving productivity by 25% while maintaining wafer quality and extending equipment lifespan.
Smart Images
Figure CN119252783A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of wafer processing, and in particular to a wafer conveying system and method of a multi-hand box station robot arm. Background Art
[0002] In order to obtain semiconductor products, such as chips, the wafers need to be processed accordingly in different processing units. In the processing of the coating and developing equipment, the wafers are mainly transferred between the wafer box, the transfer unit, the rotating unit, and the hot plate unit. At present, in order to improve production efficiency, the coating and developing equipment has been increasing the throughput per hour, usually by increasing the speed of the robot arm to improve the processing efficiency. The robot arm of the prior art is used to improve the wafer transfer efficiency by increasing the running speed of the robot arm. The mechanical structure of the robot arm generates negative pressure inside the robot arm to prevent the particles generated by the robot arm from overflowing the robot arm. During high-speed movement, the negative pressure system of the robot arm may have problems, causing more particulate impurities to overflow from the robot arm. The particulate impurities adhere to the wafer, which will cause quality problems of the wafer; and when the robot arm moves at high speed, the possibility of its own failure increases, which will also shorten the life of related parts. Therefore, the speed of the robot arm has an upper limit, and the output that can be increased is also upper limit. Summary of the invention
[0003] 1. Technical issues to be solved
[0004] In view of the shortcomings of the prior art, the present invention provides a wafer transfer system and method for a multi-hand box station robot arm, which solves the problem that the measures in the prior art improve the wafer transfer efficiency by increasing the movement speed of the robot arm, which easily leads to an increase in particle impurities overflowing from the robot arm, affecting the wafer production quality. At the same time, the robot arm runs at a high speed, the service life of parts is greatly shortened, and the overall wafer yield increase is limited.
[0005] (II) Technical solution
[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: a wafer transfer system of a multi-hand box station robot, comprising a wafer box station, a box station robot and a transfer unit, the box station robot transfers wafers between the wafer box and the transfer unit, the box station robot is provided with N forks (N≥2, and is an integer), and the box station robot can carry at most N wafers through the N forks.
[0007] Preferably, the wafer transfer system described in the above solution transfers the wafer between the wafer box and the transfer unit, specifically comprising the following steps:
[0008] Take out the wafer: The cassette station robot takes out at most N wafers from the wafer cassette;
[0009] Wafer storage to the transfer unit: The box station robot delivers up to N wafers to the transfer unit;
[0010] Obtain wafers processed by the transfer unit: The box station robot obtains at most N processed wafers on the transfer unit;
[0011] Return wafers: The cassette station robot puts up to N processed wafers back into the wafer cassette.
[0012] Preferably, the spacing between wafers stacked in pairs in the wafer box is the same as the spacing between the wafer placement units, and the N forks of the box station robot arm can smoothly transfer wafers between the transfer unit and the wafer box.
[0013] Preferably, in the step of storing the wafers in the transfer unit, the box station robot arm can independently place the single wafers one by one in the single vacant wafer placement unit in the transfer unit.
[0014] Preferably, when the box station robot arm transfers the wafer to the transfer unit, it drives the fork arm to move up and down to transfer the wafer to the idle wafer placement unit.
[0015] Preferably, the box station robot transfers the wafer between the wafer box and the transfer unit through the following steps:
[0016] Take out the wafer: the cassette station robot takes out N wafers from the wafer cassette;
[0017] Wafers are stored in the transfer unit: The box station robot arm transfers one of the N wafers to an idle wafer placement unit on the transfer unit through N forks;
[0018] The box station robot drives the fork to move: the box station robot drives N-1 forks loaded with wafers to move to the idle wafer placement units in sequence, and the N-1 forks transfer the loaded wafers to the idle wafer placement units respectively;
[0019] Obtaining wafers processed by the transfer unit: The box station robot drives N forks to obtain N processed wafers on the wafer placement unit in the transfer unit one by one. During this period, the box station robot drives the forks to move up and down to obtain the processed wafers in the wafer placement unit at different positions;
[0020] Putting back the wafers: The cassette station robot puts N processed wafers back into the wafer cassette one by one.
[0021] Preferably, the box station robot transfers N wafers between the wafer box and the transfer unit through the following steps:
[0022] Take out the wafer: the cassette station robot takes out N wafers from the wafer cassette, where N is an even number;
[0023] Wafers are stored in the transfer unit: The box station robot arm uses N forks to synchronously deliver 2 of the N wafers to the idle wafer placement unit on the transfer unit;
[0024] The box station robot drives the fork to move: the box station robot drives N-2 forks loaded with wafers to move to two idle wafer placement units in sequence, and the N-2 forks transfer the two loaded wafers to the wafer placement units synchronously;
[0025] Obtaining wafers processed by the transfer unit: The box station robot drives N forks to obtain N processed wafers on the wafer placement unit in the transfer unit in pairs. During this period, the box station robot drives the forks to move up and down to obtain the processed wafers in the wafer placement unit at different positions;
[0026] Putting back the wafers: The robotic arm of the box station puts N processed wafers back into the wafer box in pairs through the fork.
[0027] (III) Beneficial effects
[0028] The present invention has the following beneficial effects:
[0029] The wafer transfer system and method of the multi-hand box station robot arm can transport wafers individually and can carry wafers of different heights; at the same time, it can carry multiple wafers at a time or a single wafer at a time; the entire box station robot arm system can replace multiple wafers one by one. By reducing the moving distance of the box station robot arm, the same handling volume as the prior art is achieved, thereby improving the overall efficiency of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS
[0030] Figure 1 It is a schematic diagram of the overall structure of the present invention;
[0031] Figure 2 It is a schematic diagram of the layout structure of the wafer box, the box station robot and the transfer unit of the present invention;
[0032] Figure 3 It is a schematic diagram of the wafer transfer process in the prior art;
[0033] Figure 4 This is a schematic diagram of a wafer transfer process according to a first embodiment of the present invention;
[0034] Figure 5 This is a schematic diagram of the wafer transfer process of the second embodiment of the present invention:
[0035] Figure 6 It is a schematic diagram of the wafer transfer process of the present invention.
[0036] In the figure: 1. Wafer box; 2. Box station robot; 3. Transfer unit; 4. Process robot; 5. Rotation unit; 6. Hot plate unit; 7. Wafer placement unit. DETAILED DESCRIPTION
[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0038] See also Figure 1 The present invention provides a technical solution: a wafer transfer system of a multi-hand box station robot arm, comprising a wafer box station, a box station robot arm and a transfer unit, the box station robot arm transfers wafers between the wafer box and the transfer unit, the box station robot arm is provided with N forks (N≥2, and is an integer), and the box station robot arm can carry at most N wafers through the N forks.
[0039] Embodiment 1:
[0040] A wafer transfer method for a multi-hand box station robot arm, wherein the wafer is transferred between the wafer box and the transfer unit by the wafer transfer system of the above scheme, specifically comprising the following steps:
[0041] Take out the wafer: The cassette station robot takes out at most N wafers from the wafer cassette;
[0042] Wafer storage to the transfer unit: The box station robot delivers up to N wafers to the transfer unit;
[0043] Obtain wafers processed by the transfer unit: The box station robot obtains at most N processed wafers on the transfer unit;
[0044] Return wafers: The cassette station robot puts up to N processed wafers back into the wafer cassette. Figure 4 As shown, in this solution, the box station robot arm transfers N wafers in one movement between the wafer box and the transfer unit, thereby improving the wafer handling efficiency by multiple times.
[0045] In this embodiment, the spacing between the wafers in the wafer box is the same as the spacing between the wafer placement units, and the N forks of the box station robot can smoothly transfer the wafers between the transfer unit and the wafer box. Figure 5As shown, the height spacing of wafers in the wafer box is usually 10mm, and the spacing of the transfer unit is usually different from this. Taking the box station robot arm with two forks as an example, if the above solution is still used, the forks of the box station robot arm will match the height of the wafers in the wafer box (or the spacing of the wafer placement units in the transfer unit), but will not match the spacing of the wafer placement units in the transfer unit (or the height of the wafers in the wafer box), resulting in the inability to hand over wafers to the transfer unit (wafer box), which limits the scope of application of this solution. Therefore, it is necessary to control the spacing of the wafer placement units in the transfer unit, the spacing between the wafers in the wafer box and the forks to match the spacing between the upper and lower forks.
[0046] In this embodiment, the box station robot transfers N wafers between the wafer box and the transfer unit through the following steps:
[0047] Take out the wafer: the cassette station robot takes out N wafers from the wafer cassette, where N is an even number;
[0048] Wafers are stored in the transfer unit: The box station robot arm uses N forks to synchronously deliver 2 of the N wafers to the idle wafer placement unit on the transfer unit;
[0049] The box station robot drives the fork to move: the box station robot drives N-2 forks loaded with wafers to move to two idle wafer placement units in sequence, and the N-2 forks transfer the two loaded wafers to the wafer placement units synchronously;
[0050] Obtaining wafers processed by the transfer unit: The box station robot drives N forks to obtain N processed wafers on the wafer placement unit in the transfer unit in pairs. During this period, the box station robot drives the forks to move up and down to obtain the processed wafers in the wafer placement unit at different positions;
[0051] Putting back the wafers: The robotic arm of the box station puts N processed wafers back into the wafer box in pairs through the fork.
[0052] Embodiment 2:
[0053] In the step of storing wafers in the transfer unit, the box station robot can independently place single wafers one by one in the vacant single wafer placement units in the transfer unit. The height spacing of the wafers in the wafer box is usually 10mm, and the spacing of the transfer unit is usually different. The aforementioned table shows the original wafer box or the wafer placement spacing in the transfer unit, which is costly and not conducive to laying on the original production line, so the process needs to be adjusted. The wafer is transferred to the wafer placement unit on the transfer unit by independently controlling the fork arm, and then the box station robot is controlled to move in the direction of the upper and lower wafer placement units, and then the wafers on other forks are placed one by one in other vacant wafer placement units.
[0054] In this embodiment, when the box station robot transfers the wafer to the transfer unit, it drives the fork arm to move up and down to transfer the wafer to the idle wafer placement unit.
[0055] In this embodiment, the box station robot transfers the wafer between the wafer box and the transfer unit through the following steps:
[0056] Take out the wafer: the cassette station robot takes out N wafers from the wafer cassette;
[0057] Wafers are stored in the transfer unit: The box station robot arm transfers one of the N wafers to an idle wafer placement unit on the transfer unit through N forks;
[0058] The box station robot drives the fork to move: the box station robot drives N-1 forks loaded with wafers to move to the idle wafer placement units in sequence, and the N-1 forks transfer the loaded wafers to the idle wafer placement units respectively;
[0059] Obtaining wafers processed by the transfer unit: The box station robot drives N forks to obtain N processed wafers on the wafer placement unit in the transfer unit one by one. During this period, the box station robot drives the forks to move up and down to obtain the processed wafers in the wafer placement unit at different positions;
[0060] Putting back wafers: The robotic arm of the cassette station puts N processed wafers back into the wafer cassette one by one. For the specific execution process, refer to Figure 5 shown.
[0061] In the existing scheme, the wafers in the wafer box (FOUP) are arranged up and down in the wafer box, the transfer unit (TRS) is a stacked wafer placement unit, and the box station robot arm (CRA) can transfer the wafers between the wafer box and the transfer unit. Figure 3 As shown, the process is as follows (hereinafter, the movement of the transfer unit to the transfer unit refers to: the movement between the stacked wafer placement units on the transfer unit):
[0062] 1. The cassette station robot takes out a wafer (set as wafer A1) from the wafer cassette;
[0063] 2. The cassette station robot moves from the wafer cassette to the transfer unit and delivers wafer A1 to the transfer unit;
[0064] 3. The box station robot moves from the transfer unit to the transfer unit and obtains the wafer on the transfer unit (set as wafer B1);
[0065] 4. The cassette station robot moves from the transfer unit to the wafer cassette and delivers wafer B1 into the wafer cassette;
[0066] 5. The cassette station robot moves from wafer cassette to wafer cassette and takes out a wafer (set as wafer A2);
[0067] 6. The box station robot moves from the wafer box to the transfer unit and delivers wafer A2 to the transfer unit;
[0068] 7. The box station robot moves from the transfer unit to the transfer unit and obtains the wafer on the transfer unit (set as wafer B2)
[0069] 8. The box station robot moves from the transfer unit to the wafer box and delivers wafer B2 into the wafer box.
[0070] In the prior art, the robot arm needs to perform 8 actions and move 7 times to complete the transportation of wafers A1, A2, B1, and B2.
[0071] The 8 actions are: taking out wafers from the wafer box, delivering wafers to the transfer unit, taking out wafers from the transfer unit, delivering wafers to the wafer box, taking out wafers from the wafer box, delivering wafers to the transfer unit, taking out wafers from the transfer unit, delivering wafers to the wafer box;
[0072] The 7 movements are: from the wafer box to the transfer unit, from the transfer unit to the transfer unit, from the transfer unit to the wafer box, from the wafer box to the wafer box, from the wafer box to the transfer unit, from the transfer unit to the transfer unit, and from the transfer unit to the wafer box.
[0073] However, the current productivity has increasingly higher requirements for the production capacity of the coating and developing machine. If the above-mentioned single-wafer method is used for transfer, the box station robot arm can only transfer one wafer at a time between the wafer box and the transfer unit, which limits the overall productivity of the equipment. The box station robot arm used in this solution is equipped with N forks (N≥2, and is an integer), and the N forks are as similar as possible. In this way, when obtaining wafers from the wafer and placing them in the transfer unit, N wafers can be transported at one time, which greatly improves the wafer transfer efficiency.
[0074] like Figure 4 As shown, this solution takes two forks as an example. The box station robot can take out two wafers (A1 and A2 in the prior art) from the wafer box at one time, and send the two wafers to the transfer unit through horizontal movement, vertical movement, and rotational movement. Then, through vertical movement, the two wafers on the transfer unit (B1 and B2 in the prior art) are obtained, and then through horizontal movement, vertical movement, and rotational movement, the wafers B1 and B2 are sent to the wafer box. In this solution, the box station robot transfers two wafers in one movement between the wafer box and the transfer unit, which doubles the wafer handling efficiency.
[0075] The height spacing of wafers in a wafer box is usually 10mm, and the spacing of transfer units is usually different from this. Taking the box station robot with two forks as an example, if the above solution is still used, the forks of the box station robot will match the height of the wafers in the wafer box (or the spacing of the transfer units), but will not match the spacing of the transfer units (or the height of the wafers in the wafer box), resulting in the inability to hand over wafers to the transfer unit (wafer box), which limits the scope of application of this solution.
[0076] like Figure 5 As shown, this solution can ensure improved production efficiency by adjusting the process flow (hereinafter, the first to fourth transfer units refer to wafer placement units at different levels in the transfer unit, and the essence is to transfer wafers in the same transfer unit):
[0077] 1. The cassette station robot takes out two wafers (wafer A1, A2) from the wafer cassette;
[0078] 2. The cassette station robot moves from the wafer cassette to the transfer unit and delivers wafer A1 to the first transfer unit;
[0079] 3. The box station robot moves from transfer unit to transfer unit and delivers A2 to the second transfer unit;
[0080] 4. The box station robot moves from transfer unit to transfer unit to obtain B1 in the third transfer unit;
[0081] 5. The box station robot moves from transfer unit to transfer unit to obtain B2 in the fourth transfer unit;
[0082] 6. The box station robot moves from the transfer unit to the wafer box and places wafers B1 and B2 into the wafer box.
[0083] In this solution, to complete the transportation of wafers A1, A2, B1, and B2, the robot arm needs to perform 6 actions, move 3 times, and add 2 small strokes.
[0084] The 6 actions are: taking out wafers from the wafer box, delivering wafers to the transfer unit, delivering wafers to the transfer unit, taking out wafers from the transfer unit, taking out wafers from the transfer unit, and delivering wafers to the wafer box;
[0085] The three movements are: moving from the wafer box to the transfer unit, moving from the transfer unit to the transfer unit, and moving from the transfer unit to the wafer box;
[0086] The two small strokes are: moving from the transfer unit to the transfer unit in step 2, and moving from the transfer unit to the transfer unit in step 4. It should be noted that the path of the small stroke is the movement of the robot arm between different transfer units through vertical movement, and the stroke of such movement is smaller than the stroke of the robot arm between the wafer box and the transfer unit.
[0087] Compared with the prior art which has 8 actions and 7 movements, this solution improves the wafer transmission efficiency by 25%.
[0088] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "includes an element defined by ... does not exclude the existence of other identical elements in the process, method, article or device including the element".
[0089] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.
Claims
1. A wafer transfer system for a multi-hand box station robot, characterized in that: It includes a wafer box station, a box station robot and a transfer unit. The box station robot transfers wafers between the wafer box and the transfer unit. The box station robot is provided with N forks (N≥2, and is an integer). The box station robot can carry at most N wafers through the N forks.
2. A wafer transfer method for a multi-hand box station robot, characterized in that: The wafer is transferred between the wafer box and the transfer unit by the wafer transfer system as claimed in claim 1, specifically comprising the following steps: Take out the wafer: The cassette station robot takes out at most N wafers from the wafer cassette; Wafer storage to the transfer unit: The box station robot delivers up to N wafers to the transfer unit; Obtain wafers processed by the transfer unit: The box station robot obtains at most N processed wafers on the transfer unit; Return wafers: The cassette station robot puts up to N processed wafers back into the wafer cassette.
3. The wafer transfer method of a multi-hand box station robot according to claim 2, characterized in that: The stacking distance between two wafers in the wafer box is the same as the distance between two wafer placement units, and the N forks of the box station robot arm can smoothly transfer wafers between the transfer unit and the wafer box.
4. The wafer transfer method of a multi-hand box station robot according to claim 2, characterized in that: In the step of storing the wafers in the transfer unit, the box station robot arm can independently place the single wafers one by one in the single vacant wafer placement unit in the transfer unit.
5. The wafer transfer method of a multi-hand box station robot according to claim 4, characterized in that: When the box station robot arm transfers the wafer to the transfer unit, it drives the fork arm to move up and down to transfer the wafer to the idle wafer placement unit.
6. The wafer transfer method of a multi-hand box station robot according to claim 4, characterized in that: The box station robot transfers the wafer between the wafer box and the transfer unit through the following steps: Take out the wafer: the cassette station robot takes out N wafers from the wafer cassette; Wafers are stored in the transfer unit: The box station robot arm transfers one of the N wafers to an idle wafer placement unit on the transfer unit through N forks; The box station robot drives the fork to move: the box station robot drives N-1 forks loaded with wafers to move to the idle wafer placement units in sequence, and the N-1 forks transfer the loaded wafers to the idle wafer placement units respectively; Obtaining wafers processed by the transfer unit: The box station robot drives N forks to obtain N processed wafers on the wafer placement unit in the transfer unit one by one. During this period, the box station robot drives the forks to move up and down to obtain the processed wafers in the wafer placement unit at different positions; Putting back the wafers: The cassette station robot puts N processed wafers back into the wafer cassette one by one.
7. The wafer transfer method of a multi-hand box station robot according to claim 3, characterized in that: The box station robot transfers N wafers between the wafer box and the transfer unit through the following steps: Take out the wafer: the cassette station robot takes out N wafers from the wafer cassette, where N is an even number; Wafers are stored in the transfer unit: The box station robot arm uses N forks to synchronously deliver 2 of the N wafers to the idle wafer placement unit on the transfer unit; The box station robot drives the fork to move: the box station robot drives N-2 forks loaded with wafers to move to two idle wafer placement units in sequence, and the N-2 forks transfer the two loaded wafers to the wafer placement units synchronously; Obtaining wafers processed by the transfer unit: The box station robot drives N forks to obtain N processed wafers on the wafer placement unit in the transfer unit in pairs. During this period, the box station robot drives the forks to move up and down to obtain the processed wafers in the wafer placement unit at different positions; Putting back the wafers: The robotic arm of the box station puts N processed wafers back into the wafer box in pairs through the fork.