A fork and a robotic arm

Abstract

This invention discloses a fork and a robotic arm. The fork includes a connecting portion and a first finger, a second finger, and a third finger extending from the connecting portion. The first, second, and third fingers are located on the same side of the connecting portion, with the second finger positioned between the first and third fingers. Each of the first, second, and third fingers has an adsorption portion, where the line connecting the three adsorption portions forms a triangle for fixing wafers of different sizes. The projection of the smallest wafer onto the fork covers the three adsorption portions. The end of the second finger away from the connecting portion can abut against a teach pendant for teaching. The fork can perform teaching using the added second finger and simultaneously position the wafer using the adsorption method of the three adsorption portions, enabling the fixing of wafers of different sizes.

Description

Technical Field

[0001] This invention relates to the field of wafer processing equipment technology, and more particularly to a fork and a robotic arm. Background Technology

[0002] The robotic arm includes a fork used to carry and hold the wafer. Before the wafer is aligned by the alignment device, the position of the fork for picking up and placing the wafer needs to be taught to ensure that the wafer placed on the alignment device is aligned with the central axis of the alignment device's stage. Currently, there are various wafer sizes available, such as 8-inch and 12-inch; however, each fork can only hold one size wafer, resulting in low versatility. Summary of the Invention

[0003] To overcome the above-mentioned shortcomings, the present invention aims to provide a fork and a robotic arm that can use an added second finger to cooperate with a teach pendant for teaching without the need for additional teaching equipment. At the same time, it uses at least three adsorption parts to position the wafer, which can be used to fix wafers of different sizes and has high versatility.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a fork, the fork including a connecting portion and a first finger, a second finger, and a third finger extending from the connecting portion, the first finger, the second finger, and the third finger being located on the same side of the connecting portion; each of the first finger, the second finger, and the third finger is provided with an adsorption portion, wherein the line connecting the three adsorption portions forms a triangle for fixing wafers of different sizes, the projection of the smallest wafer on the fork covering the three adsorption portions, and the end of the second finger away from the connecting portion can abut against a teach pendant for teaching; the fork extends into a loading lock chamber to pick up and place the wafer, the loading lock chamber being provided with two support pillars spaced apart along a second direction, the two support pillars being located between the first finger and the third finger, and the second finger being located between the two sets of support pillars.

[0005] Furthermore, the adsorption section includes an air extraction hole and a first protrusion. The first protrusion is a closed-loop structure that forms an adsorption cavity, and the wafer is adsorbed onto the first protrusion.

[0006] Furthermore, the first boss is in contact with the wafer line.

[0007] Furthermore, the adsorption section also includes a second protrusion located within the adsorption cavity, which contacts the wafer when the wafer is adsorbed.

[0008] Furthermore, when the adsorption portion includes the second protrusion, the second protrusion is in contact with the wafer line.

[0009] Furthermore, with reference to the connecting portion, among the first finger, the second finger, and the third finger, the second finger is the shortest relative to the connecting portion.

[0010] Furthermore, the first finger, the second finger, and the third finger are arranged sequentially along the second direction, and each adsorption portion includes a center line parallel to the second direction. The center of the wafer is located between the center line of the adsorption portion of the second finger and the center line of the adsorption portion of the first finger, and between the center line of the adsorption portion of the second finger and the center line of the adsorption portion of the third finger.

[0011] Furthermore, the number of air extraction holes in the adsorption section is equal.

[0012] Furthermore, the first finger, the second finger, and the third finger each include a finger body, and each finger body is provided with the adsorption part, which is also the same thickness as the connecting part.

[0013] Furthermore, the fork also includes a detection component and an adjustment component. The detection component is used to detect the orientation of the wafer, and the adjustment component includes a suction cup and a fine-tuning part. The fine-tuning part adjusts the height position of the suction cup according to the detection result of the detection component so that the suction cup can abut against the lower surface of the warped portion of the wafer.

[0014] Furthermore, at least a portion of the adsorption section is provided with the detection component and the adjustment component, the adjustment component is located within the adsorption cavity, and the detection component is disposed on the first protrusion.

[0015] Furthermore, at least one of the tip of the second finger and the teaching block is provided with a sensing part, which is used for mutual sensing between the tip of the second finger and the teaching block.

[0016] The present invention also discloses a robotic arm, including the aforementioned fork. Attached Figure Description

[0017] Figure 1 This is a three-dimensional structural diagram of the fork in an embodiment of the present invention; Figure 2 This is a top view of the fork during teaching in an embodiment of the present invention; Figure 3 for Figure 2 Enlarged view at point B in the middle; Figure 4 for Figure 2 A sectional view along line AA. Figure 5 This is a schematic diagram of the first protrusion in contact with the wafer line in an embodiment of the invention; Figure 6 This is a schematic diagram of the wafer-bearing state in an embodiment of the present invention; Figure 7 This is a schematic diagram of the wafer pick-and-place mechanism in the loading lock chamber in an embodiment of the present invention; Figure 8 This is a schematic diagram illustrating the teaching of the fork in the loading lock chamber in an embodiment of the present invention.

[0018] In the picture: 1. Fork; 11. Connecting part; 111. Second marking groove; 12. First finger; 121. First marking groove; 13. Second finger; 131. End; 14. Third finger; 1a. Finger body; 15. Adsorption part; 151. First boss; 1511. Left side; 1512. Right side; 1513. Contact part; 1514. Flat surface; 152. Air extraction hole; 153. Adsorption cavity; 154. Second boss; 16. Detection component; 17. Adjustment component; 171. Suction cup; 172. Fine adjustment part; 2. Demonstration block; 3. Wafers; 4. Loading lock chamber; 41. Support assembly. Detailed Implementation

[0019] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0020] The present invention provides a fork 1 for supporting and fixing a wafer 3.

[0021] See appendix Figure 1 and attached Figure 2 As shown, the fork 1 includes a connecting portion 11 and a first finger 12, a second finger 13, and a third finger 14 extending from the connecting portion 11. The first finger 12, the second finger 13, and the third finger 14 are located on the same side of the connecting portion 11. Exemplarily, the first finger 12, the second finger 13, and the third finger 14 extend from one side of the connecting portion 11 along a first direction, and they are parallel. However, the first finger 12, the second finger 13, and the third finger 14 may not be parallel. In this case, non-parallelism means that only two of them are not parallel; for example, the first finger and the second finger are parallel, but they are not parallel to the third finger, or all of them are not parallel. In short, in the case of non-parallelism, as long as the angles of the first finger 12, the second finger 13, and the third finger 14 do not affect the handling of the wafer, it is acceptable. The second finger 13 is located between the first finger 12 and the third finger 14. In one embodiment, the first finger 12 and the third finger 14 are located on both sides of the second finger 13 in a second direction, and the first direction and the second direction are perpendicular in the horizontal plane.

[0022] Each of the first finger 12, the second finger 13, and the third finger 14 is provided with an adsorption part 15, wherein the lines connecting the three adsorption parts 15 form a triangle to fix wafers 3 of different sizes. The projection of the smallest wafer 3 onto the wafer fork 1 covers the three adsorption parts 15. The phrase "three adsorption parts 15" refers to three out of the total number of adsorption parts 15 on the first finger 12, the second finger 13, and the third finger 14; that is, the lines connecting three adsorption parts form a triangle. Of course, if there are four adsorption parts, the lines connecting these four adsorption parts will be quadrilaterals, but the lines connecting three of them can form a triangle. This is because, in some cases, a finger may have more than one adsorption part 15.

[0023] Based on the structure of the fork described above, the fork has the following beneficial effects: 1) The lines connecting the three adsorption sections 15 form a triangle, and these three points define a plane to stably support the wafer 3. This helps to suppress tilting, shaking, or rotation of the wafer 3 during transport. Combined with the vacuum adsorption of the wafer 3 by the adsorption sections 15, the stability of the wafer 3 held in place by the fork 1 is improved when the fork 1 moves. The vacuum adsorption of the wafer 3 by the adsorption sections 15 can handle wafers 3 of different sizes (e.g., ...). Figure 6 (The thick dashed line indicates one type of wafer, and the thin dashed line indicates another type of wafer) are both fixed. The projection of the smallest wafer 3 onto the fork 1, covering the three adsorption portions 15, means that wafers larger than the smallest size can also be fixed by the fork. This ensures that the fork 1 can fix wafers 3 of different sizes. Moreover, because the lines connecting the three adsorption portions 15 form a triangle, wafers of each size can be stably fixed.

[0024] 2) The end 131 of the second finger 13 away from the connecting part 11 can abut against the teaching block 2 (e.g., the side wall of the teaching block 2) for teaching. The teaching block 2 is placed on the alignment device. When the end 131 of the second finger 13 away from the connecting part 11 abuts against the side wall of the teaching block 2, the fork 1 reaches the teaching position. When the fork 1 picks up or puts down the wafer 3 in this teaching position, the center of the wafer 3 coincides with the center of the rotating platform of the alignment device in the wafer thickness direction. When the fork 1 moves to this teaching position, the robotic arm can drive the fork 1 to move downward to place the wafer 3 on the rotating platform for rotational alignment of the wafer 3 or to remove the wafer 3 from the rotating platform. Directly using the end 131 of the second finger 13 as the teaching reference eliminates the need for additional teaching tools, simplifying the teaching process of the fork 1.

[0025] For example, the sidewall of the teaching block 2 is annular, and the vertical end face of the second finger 13 away from the connecting part 11 can abut against the sidewall of the teaching block 2. In this case, the vertical end face of the second finger 13 away from the connecting part 11 is an arc surface, and the arc surface matches the curvature of the annular sidewall of the teaching block 2. Of course, the sidewall of the teaching block 2 can also be other structures, such as a planar or stepped structure. In this case, the end 131 of the second finger 13 away from the connecting part 11 can be designed to fit the sidewall of the teaching block 2.

[0026] Compared to the two-finger structure of the fork 1 in related technologies, the fork 1 in this embodiment is a three-finger structure, with an additional second finger 13 located in the middle. The adsorption portions 15 on the first finger 12, the second finger 13, and the third finger 14 form a three-point adsorption structure, providing stable support for the wafer 3. This effectively suppresses tilting, shaking, or rotation of the wafer 3 during handling and can be used to adsorb wafers 3 of different sizes. Since the fork 1 can support and fix the wafer 3, no additional teaching device is needed. The end 131 of the second finger 13 away from the connecting portion 11 serves as a movable detection point, and the side wall of the teaching block 2 serves as a fixed physical reference. Once the two are against each other, the teaching of the fork 1 is completed. The fork 1 has a simple structure, requiring only the addition of a second finger 13. While fixing the wafer 3, the teaching can be directly completed using the fork 1's own structure.

[0027] In one embodiment, the tip 131 of the second finger 13 and the teaching block 2 (e.g., the side wall of the teaching block 2) can sense each other through a sensing element. The sensing element can be located on the tip of the second finger 13, on the teaching block 2, or on both the tip of the second finger 13 and the teaching block 2. In this case, in addition to mechanical contact for teaching, the tip 131 of the second finger 13 and the teaching block 2 can also be positioned using the sensing element, ensuring that the tip 131 of the second finger 13 is in contact with the side wall of the teaching block 2, and that a technician can intuitively know that the tip 131 has made contact with the teaching block 2. One implementation of mutual sensing is as follows: a sensor (e.g., a proximity switch) is provided on the tip 131 of the second finger 13 or the teaching block 2. When the tip 131 of the second finger 13 and the teaching block 2 are in contact, the sensor emits a signal (e.g., an indicator light illuminates). Exemplarily, in some other embodiments, mutual sensing can be achieved using a Hall element fixed to the tip 131 of the second finger 13 or the teaching block 2.

[0028] In one embodiment, the lines connecting the three adsorption parts 15 form an isosceles triangle. The adsorption part 15 of the second finger 13 is on the axis of symmetry of this isosceles triangle. The center of the triangle and the center of the wafer 3 coincide in the thickness direction of the wafer. At this time, the line of action of the gravity of the wafer 3 passes perpendicularly through the center of the triangle, and no additional torque is generated, thus avoiding the wafer 3 from undergoing slight rotation or tilting during transportation.

[0029] See appendix Figure 3 As shown, the adsorption section 15 includes an air extraction hole 152 and a first protrusion 151. The first protrusion 151 has a closed-loop structure, forming an adsorption cavity 153. The shape of the adsorption cavity 153 is not limited to that shown. Figures 1 to 3 The racetrack-shaped design shown is intended to create a sealed space around the wafer after it is adsorbed, thus holding the wafer in place. For example, the shape of the adsorption cavity 153 can be circular, elliptical, square, etc. The vent 152 connects to the interior of the adsorption cavity 153. Based on this function, the vent 152 is not limited to the shape shown. Figure 1 and Figure 2 As shown, located at the bottom of the adsorption chamber 153, the adsorption chamber 153 can be evacuated through the evacuation port 152. The evacuation port 152 is connected to an external vacuum generator through a gas channel inside the fork 1. The vacuum generator can evacuate air at the evacuation port 152 to create a negative pressure in the adsorption chamber 153. When the first protrusion 151 supports the wafer 3, the wafer 3 covers the opening of the adsorption chamber 153. At this time, the evacuation port 152 evacuates air, and the adsorption chamber 153 is in a negative pressure environment to adsorb the wafer 3. The wafer 3 rests against the first protrusion 151 and will not move.

[0030] The adsorption cavity 153 increases the adsorption area for the wafer 3. Compared to the direct adsorption of the wafer 3 via the suction port 152, the larger adsorption area provides a more stable fixation for the wafer 3. Compared to the porous suction cup 171 or the open suction groove, the leakage path of the adsorption cavity 153 is limited to the contact surface between the first protrusion 151 and the wafer 3. Even if the vacuum generator fluctuates briefly, the adsorption cavity 153 can maintain a certain residual negative pressure, preventing the wafer 3 from falling off instantly. Simultaneously, using the first protrusion 151 to support the wafer 3, in some embodiments (e.g., the width of the first protrusion 151 is narrow), helps reduce the contact area between the adsorption part 15 and the wafer 3, avoiding friction scratches or particle marks on the back of the wafer 3 caused by the large-area suction cup 171. Furthermore, by supporting the wafer 3 with the first protrusion 151, the lines connecting the three adsorption parts form a triangle, which better supports the wafer 3. Combined with the vacuum adsorption, these three methods provide better support for the wafer 3, ensuring its stability.

[0031] Based on the structure of the adsorption cavity 153, reasonably controlling the volume of the adsorption cavity 153 is also beneficial to reduce the contact between the first protrusion 151 and the wafer 3, which helps to reduce the imprints and wear on the wafer 3.

[0032] In one embodiment, see Appendix Figure 4 The first protrusion 151 is in contact with three sides of the wafer, and at this time, the upper surface of the first protrusion 151 is a plane 1514. For example, the cross-section of the first protrusion 151 along the thickness direction is rectangular, trapezoidal, etc.

[0033] In one embodiment, see Appendix Figure 5 The first protrusion 151 makes line contact with wafer 3. How can we achieve unlimited line contact, for example? Figure 5 In the middle, the first protrusion 151 includes a left side 1511 and a right side 1512. The left side 1511 and the right side 1512 intersect to form a contact portion 1513, which contacts the wafer 3 line. Of course, the left side 1511 and the right side 1512 can intersect in a line or in an arc (only the arc is small enough to form a line contact). For example, the cross section of the first protrusion 151 along the wafer thickness direction is triangular, arc-shaped, etc.

[0034] By having the first protrusion 151 make contact with the wafer 3, it is beneficial to reduce the contact area between the first protrusion 151 and the wafer 3, thereby reducing the marks and wear on the wafer 3.

[0035] In one embodiment, the adsorption part 15 further includes a second protrusion 154 located within the adsorption cavity 153. When the wafer 3 is adsorbed, the second protrusion 154 contacts the wafer 3. The upper surface of the second protrusion 154 is flush with that of the first protrusion 151, and the second protrusion 154 can also be used to support the wafer 3. The addition of the second protrusion 154 increases the contact area between the adsorption part 15 and the wafer 3, providing more stable support for the wafer 3. When the adsorption cavity 153 adsorbs the wafer 3, the adsorption force may be too large, causing deformation of the part of the wafer 3 aligned with the adsorption cavity 153, resulting in a depression towards the inside of the adsorption cavity 153. At this time, the second protrusion 154 located within the adsorption cavity 153 can support the wafer 3, limit the downward depression of the wafer 3, reduce the deformation of the wafer 3 caused by the adsorption force of the adsorption cavity 153, and enhance the bending resistance.

[0036] The shape and number of the second protrusion 154 are not limited. In some embodiments, a gap is left between the second protrusion 154 and the first protrusion 151 to facilitate airflow and vacuuming of the adsorption cavity 153. The aforementioned gap ensures that the second protrusion 154 does not divide the adsorption cavity 153 into two non-conductive cavities, thus ensuring that the suction force is the same throughout the entire adsorption cavity 153.

[0037] In one embodiment, the projection of the second protrusion 154 onto the projection plane parallel to the wafer 3 is elongated. The adsorption cavity 153 is symmetrically arranged with the second protrusion 154 as the centerline, and the second protrusion 154 is centrally located within the adsorption cavity 153. The centrally located second protrusion 154 acts as a central support. The adsorption force generated by the negative pressure of the adsorption cavity 153 is equal to the left and right or the top and bottom of the centerline of the second protrusion 154. After the wafer 3 comes into contact with the second protrusion 154, it will not twist around the axis of the second protrusion 154 due to the greater adsorption force on one side and the less adsorption force on the other side.

[0038] The second protrusion 154 is in line contact or surface contact with the wafer 3. The cross-section of the second protrusion 154 and the first protrusion 151 along the wafer thickness direction may be the same or different, and can be rectangular, trapezoidal, triangular, arc-shaped, etc. Through line contact, the smaller the contact area between the second protrusion 154 and the wafer 3, the fewer imprints and wear will be on the wafer 3.

[0039] See appendix Figure 1 With reference to the connecting portion 11, among the first finger 12, the second finger 13, and the third finger 14, the second finger 13 is the shortest relative to the connecting portion 11. The second finger 13 serves a teaching function; therefore, when the second finger 13 is away from the end 131 of the connecting portion 11 and abuts against the teaching block 2, the first finger 12 and the third finger 14 need to extend to the other side of the teaching block 2 to ensure that the center of the wafer 3 and the center of the teaching block 2 coincide in the wafer thickness direction.

[0040] The first finger 12 and the third finger 14 are of equal length, or they can be of unequal length. For example, the first finger 12 and the third finger 14 are of equal length and are symmetrically arranged on both sides of the second finger 13 in the second direction. In this case, when the wafer fork 1 extends into the wafer cassette 3 to retrieve the wafer, it avoids the situation where the longer finger might touch the side wall of the wafer cassette 3 first due to the unequal length of the two fingers. The equal-length design of the first finger 12 and the third finger 14 makes it easier to enter the wafer cassette 3 to retrieve and place the wafer 3 without colliding with the side wall of the wafer cassette 3. In the above arrangement, since the second finger 13 is the shortest, see [reference needed]. Figure 2 Teaching is performed using the end face of the second finger 13 and the side wall of the teaching block 2. The first finger 12 and the third finger 14 are relatively long, which ensures that the triangle formed by the adsorption part on the first finger 12, the adsorption part on the third finger 14, and the adsorption part on the second finger 13 can cover the teaching block 2. At this time, the center of the wafer 3 picked up by the fork can coincide with the center of the teaching block 2 in the wafer thickness direction.

[0041] See appendix Figure 6 The first, second, and third fingers are arranged sequentially along a second direction. Each adsorption portion 15 includes a center line parallel to the second direction. The center O of the wafer 3 is located between the center line L1 of the adsorption portion 15 of the second finger 13 and the center line of the adsorption portion 15 of the first finger 12, and between the center line L1 of the adsorption portion 15 of the second finger 13 and the center line of the adsorption portion 15 of the third finger 14. For example, since the first finger 12 and the third finger 14 are of equal length, the center lines of the adsorption portions 15 of the first finger 12 and the third finger 14 coincide, both being L2.

[0042] As described above, the center of the wafer is located within the triangle formed by the lines connecting the three adsorption sections 15, which helps prevent the wafer from tilting forward.

[0043] The number of air extraction holes 152 in each adsorption section 15 is equal, such as Figure 1 and Figure 2 As shown, each adsorption section 15 has only one evacuation port 152. In some embodiments, there may be two, three, etc., respectively. When there is only one evacuation port 152 in each adsorption section 15, each evacuation port 152 is connected to a vacuum generator, which ensures that each adsorption section 15 simultaneously adsorbs the wafer 3 under negative pressure and that the generated negative pressure is the same. The number of evacuation ports 152 can be set according to actual needs, such as one, two, or three. For example, one evacuation port 152 is provided, which facilitates processing and meets usage requirements.

[0044] Each adsorption section 15 has the same structure, but its size and arrangement can be designed according to actual needs. For example, see the attached diagram. Figure 1 In one embodiment, the width of the second finger 13 in the second direction is wider than the widths of the first finger 12 and the third finger 14 respectively. Therefore, the adsorption cavity 153 on the second finger 13 extends along the second direction, while the adsorption cavities 153 of the first finger 12 and the third finger 14 extend along the first length direction. In some embodiments, the structures of the air extraction holes 152 may also be different, as long as they have the same airflow rate.

[0045] As described above, since the number of air extraction holes in each adsorption section is the same, their air flow rates are the same, and the adsorption force of each adsorption section on the wafer is the same, which helps to ensure that the wafer is stably adsorbed onto the wafer fork.

[0046] The fork 1 is an integrated structure. The first finger 12, the second finger 13, and the third finger 14 each include a finger body 1a. Each finger body 1a is provided with an adsorption part 15. In one embodiment, see attached drawing. Figure 4 and combined Figure 1 The first protrusion 151 and the second protrusion 154 extend upward along the upper surface of the finger body 1a, ensuring that only the first protrusion 151 and the second protrusion 154 can contact the wafer 3. Of course, Figure 1 and Figure 2 The illustration shows that the number of adsorption parts 15 on each finger body is equal, one in each case; however, the number of adsorption parts may not be equal. Each finger body 1a has the same thickness as the connecting part 11.

[0047] As described above, with each finger body 1a and the connecting part 11 having the same thickness, and the adsorption part being disposed on the finger body, the total thickness of the fork is the sum of the thickness of the finger body 1a and the thickness of the adsorption part 15 protruding from the finger body 1a. Based on this structure, the sum of the thicknesses can be controlled to be small, making it easier for the fork to extend into the wafer slot in the wafer cassette 3, and preventing the wafer from being difficult to pick up or put down due to the large thickness of the fork 1.

[0048] Because wafer 3 may have problems such as warping or tilting, wafer 3 may not be able to abut well against the first protrusion 151. There will be a gap between wafer 3 and the first protrusion 151, which will cause the adsorption cavity 153 to be not well sealed. Therefore, the adsorption cavity 153 cannot be well evacuated, causing the adsorption part 15 to be unable to adsorb and fix wafer 3. At this time, when the fork 1 moves wafer 3, wafer 3 may slide on the fork 1 or even fall off.

[0049] In one embodiment, see Figure 3 and Figure 4 The fork 1 also includes a detection component 16 and an adjustment component 17. The detection component 16 is used to detect the orientation of the wafer 3. The adjustment component 17 includes a suction cup 171 and a fine-tuning part 172. The fine-tuning part 172 adjusts the height position of the suction cup 171 according to the detection result of the detection component 16, so that the suction cup 171 can abut against the lower surface of the warped portion of the wafer 3. The orientation includes warped and flat. When the detection result of the detection component 16 is that the wafer 3 is flat, the wafer 3 can be well fixed by the adsorption part 15; when the detection result of the detection component 16 is that the wafer 3 is warped, the fine-tuning part 172 raises the height position of the suction cup 171 to ensure that the suction cup 171 can adsorb the wafer 3.

[0050] In this embodiment, a detection component 16 and an adjustment component 17 are provided. The adjustment component 17 adjusts the height of the suction cup 171 according to the posture detection result of the detection component 16. Even if the wafer 3 is warped, the height of the suction cup 171 can be adjusted so that the suction cup 171 is always in contact with the wafer 3 and thus adsorbs the wafer 3, preventing the wafer 3 from falling off the fork 1.

[0051] Initially, the upper surface of the suction cup 171 is not higher than the upper surface of the first protrusion 151, so the wafer 3 will not be lifted off the first protrusion 151. When the wafer 3 is flat, the vacuum of the corresponding adsorption cavity 153 is drawn through the evacuation hole 152 to adsorb the wafer 3. When the detection component 16 detects that the wafer 3 at the corresponding position is warped, the suction cup 171 driven by the fine adjustment part 172 moves upward to adsorb the warped wafer 3, preventing the wafer 3 from falling off the fork 1 during movement because it is not adsorbed by the adsorption part 15.

[0052] The detection component 16 and the adjustment component 17 are each corresponding to one adsorption part 15. That is, in the exemplary case, when there are three adsorption parts 15, there are three detection components 16 and three adjustment components 17. Each adsorption part 15 is provided with a detection component 16 and an adjustment component 17. The adjustment component 17 is located inside the adsorption cavity 153, and the detection component 16 is located on the first protrusion 151.

[0053] Initially, the upper surface of the suction cup 171 is slightly lower than the upper surface of the first protrusion 151. At this time, when the wafer 3 is placed on the first protrusion 151, the wafer 3 will not come into contact with the suction cup 171, and a gap remains between the suction cup 171 and the wafer 3. Therefore, when the evacuation port 152 evacuates air, a vacuum can be drawn into the adsorption cavity 153 to fix the wafer 3. Of course, initially, the upper surface of the suction cup 171 can also be at the same height as the bearing surface of the bearing protrusion, in which case the suction cup 171 can adsorb the wafer 3.

[0054] In one embodiment, the detection component 16 is a pressure sensor disposed on the first boss 151. The pressure sensor can collect the pressure value at the first boss 151 and perform wafer 3 orientation detection based on the pressure value collected by the pressure sensor.

[0055] Ideally, wafer 3 should be flat, so the pressure on different first protrusions 151 supporting wafer 3 should be the same. However, if wafer 3 is warped, its lower surface may not abut against the first protrusion 151. In this case, the pressure on different first protrusions 151 will be different, and the pressure sensors on different first protrusions 151 will collect different pressure values. When the pressure value collected by one pressure sensor is less than the pressure values ​​collected by other pressure sensors, wafer 3 is warped at the corresponding position of that pressure sensor. At this time, the fine-tuning part 172 at that pressure sensor drives the suction cup 171 to move upward, so that the upper surface of the suction cup 171 protrudes upward from the first protrusion 151 to abut against the warped part of wafer 3.

[0056] In one embodiment, the detection component 16 can also be a distance sensor. When the wafer 3 is not warped, the distance detected by the distance sensor should be zero. When the wafer 3 is warped, the distance sensor can detect the distance between the upper surface of the first protrusion 151 and the lower surface of the wafer 3.

[0057] In one embodiment, only one detection component 16 is provided on a first boss 151, and the positions of the detection component 16 and the suction cup 171 are as close as possible, so that the wafer 3 pose detected by the detection component 16 is the wafer 3 position where the suction cup 171 is located.

[0058] In one embodiment, a plurality of detection components 16 may be provided on a first boss 151, and the detection components 16 may be evenly distributed on the first boss 151.

[0059] In one embodiment, the fine-tuning part 172 is a piezoelectric ceramic, see Appendix Figure 4The piezoelectric ceramic has a ring structure and is arranged around the vent 152. The suction cup 171 is fixed on the piezoelectric ceramic, and the suction cup 171 and the vent 152 are electrically connected. The detection component 16 is located on the first protrusion 151 closest to the vent 152. The closer the detection component 16 is to the vent 152, that is, the closer it is to the suction cup 171, the more accurately it can detect the orientation of the wafer 3 at the suction cup 171.

[0060] Piezoelectric ceramics are elastic; they elongate when pressure is applied and shorten when pressure is released. Although the deformation of piezoelectric ceramics is small, only a few micrometers, it can meet the handling requirements of warped wafers 3. Initially, the piezoelectric ceramics are not powered, so they do not extend, and the upper surface of the chuck 171 fixed to the piezoelectric ceramics is not higher than the upper surface of the first protrusion 151. When the detection component 16 detects warping of the wafer 3 at this adsorption part 15, it powers the piezoelectric ceramics, causing them to move the chuck 171 upwards. Different voltages can be applied to the piezoelectric ceramics according to the degree of warping of the wafer 3 at this location, thus moving the chuck 171 upwards by different distances.

[0061] A wire channel can be provided on the fork 1, and the wires supplying power to the piezoelectric ceramic can be arranged in the wire channel. Alternatively, the wire channel can be omitted, and the wires supplying power to the piezoelectric ceramic can be directly arranged in the gas channel.

[0062] In one embodiment, the suction cup 171 is a rubber suction cup, which makes elastic contact with the wafer 3. The elasticity of the rubber suction cup itself can compensate for the excessive error when the piezoelectric ceramic lifts the rubber suction cup. When the wafer 3 is against the rubber suction cup, the rubber suction cup will be slightly deformed under the gravity of the wafer 3. At this time, even if the piezoelectric ceramic causes the rubber suction cup to move up a slightly larger distance, the rubber suction cup will not cause the wafer 3 to move up because of the adsorption of the wafer 3 by other adsorption parts 15. Instead, the deformation of the suction cup 171 itself is used to compensate for this error.

[0063] When the warpage of wafer 3 is too large, even if the suction cup 171 is raised, it will not be able to hold wafer 3. Therefore, when the detection component 16 detects that the warpage of wafer 3 exceeds the threshold, it will issue an alarm.

[0064] For example, when the detection component 16 is a pressure sensor, the maximum and minimum values ​​of the pressure values ​​collected by the pressure sensor are found; Calculate the difference between the maximum and minimum values ​​to obtain the maximum difference; Determine whether the maximum difference is greater than a set threshold; If so, wafer 3 is determined to be abnormal and an abnormal alarm signal is issued; if not, the adjustment component 17 adjusts the height position of the suction cup 171 to adsorb wafer 3.

[0065] The adjustment component 17 adjusts the height of the suction cup 171 to adsorb the wafer 3. Specifically, it includes raising the height of the suction cup 171 by adjusting the fine-tuning part 172 corresponding to the pressure sensor whose pressure value is not the maximum value, so that the suction cup 171 and the warped part of the wafer 3 come into contact to adsorb the wafer 3.

[0066] In one embodiment, the fork 1 is further provided with a plurality of marking grooves for positioning wafers 3 of different sizes, and the marking grooves are concentrically arranged. See the appendix for an example. Figure 6 The fork 1 can support both 8-inch and 12-inch wafers 3. The marking groove includes a first marking groove 121 for positioning the 8-inch wafer and a second marking groove 111 for positioning the 12-inch wafer. The first marking groove 121 is provided on at least two of the first finger 12, the second finger 13, and the third finger 14, and the second marking groove 111 is provided on the connecting part 11.

[0067] The marking groove is formed downwards along the upper surface of the connecting part 11 and the finger body, without obstructing the placement of the wafer 3. When the edge of the wafer 3 and the corresponding marking groove coincide in the wafer thickness direction, it indicates that the wafer 3 on the fork 1 is in place.

[0068] See appendix Figure 7 and Figure 8 The fork 1 can also pick up and place the wafer 3 inside the loading lock chamber 4. The loading lock chamber 4 is equipped with a support assembly 41 for carrying the wafer 3, which includes support pillars spaced apart in a second direction. When the fork 1 places the wafer 3 on the support pillars, it needs to avoid them. Therefore, when the fork 1 enters the loading lock chamber 4, the first finger 12 and the third finger 14 are located outside the support pillars, that is, two support pillars (four support pillars in the figure) are located between the first finger 12 and the third finger 14, and the second finger 13 is located between the two support pillars. In some embodiments, see... Figure 7 There are a total of four support pillars. Two of the support pillars are located near the connecting part, between the first and third fingers, and the second finger is located between the two support pillars. The other two support pillars are farther away from the connecting part 11 than the ends of the first and third fingers.

[0069] To allow the fork 1 to avoid the support pillars, the distance D1 between the opposing surfaces of the first finger 12 and the third finger 14 in the second direction must be greater than the distance D2 between the opposing surfaces of the two support pillars in the second direction, and the width of the second finger 13 in the second direction must be less than the distance D3 between the opposing surfaces of the two support pillars in the second direction. The design of the distance and width of the fork 1's fingers ensures that the fork 1 can enter and exit the loading lock chamber 4 and place the wafer 3 on the support assembly 41.

[0070] The width of the support component 41 in the second direction is fixed. To make room for the support component 41, in some embodiments, the distance D1 between the opposite faces of the first finger 12 and the third finger 14 in the second direction is greater than 171 mm, which is larger than the width of the fork 1 in the related art, which is typically 137 mm. Because the distance between the first finger 12 and the third finger 14 in the second direction is larger, the area of ​​the triangle formed by the lines connecting the three adsorption parts 15 can be larger, thus providing more stable support and fixation for the large-sized wafer 3.

[0071] See appendix Figure 8 The loading lock chamber 4 can also hold a teaching block 2. Before the wafer is picked up or placed in the loading lock chamber 4, the fork can also be used for teaching through the tip of the second finger.

[0072] In one embodiment, a robotic arm is also described, including a robotic arm body and a fork 1 fixedly connected to the robotic arm body, wherein the robotic arm body can drive the fork 1 to move.

[0073] In one embodiment, a wafer 3 teaching method is also described, using the aforementioned wafer 3, specifically including: The fork 1 moves to the end 131 of the second finger 13 and abuts against the side wall of the teaching block 2, and the position of the fork 1 at this time is recorded as the standard position; The fork 1 picks up and places the wafer 3 on the alignment device at the standard position.

[0074] After the fork 1 picks up the wafer 3, the position of the wafer 3 is detected by the detection component 16. The fine-tuning unit 172 adjusts the height of the chuck 171 according to the detection result of the detection component 16, so that the chuck 171 can abut against the lower surface of the warped portion of the wafer 3. Specifically, this includes: Based on the data collected from each detection unit, it is determined whether wafer 3 is warped in the corresponding adsorption unit 15; If wafer 3 is warped, the warping of wafer 3 is determined to be within the allowable range based on the data collected by each detection component 16. If not, determine that wafer 3 is abnormal and issue an abnormal alarm signal; If so, the fine-tuning part 172 at the warped adsorption part 15 raises the height position of the chuck 171 to adsorb the warped part of the wafer 3.

[0075] For example, when the detection component 16 is a pressure sensor, if the pressure values ​​collected by the pressure sensors are not equal, the wafer 3 is warped, and the adsorption part 15 corresponding to the pressure sensor with the smaller pressure value is warped. The maximum and minimum pressure values ​​collected by the pressure sensors are found; the difference between the maximum and minimum values ​​is calculated to obtain the maximum difference; it is determined whether the maximum difference is greater than a set threshold; if so, it is not within the allowable range, and the wafer 3 is warped significantly, the fork 1 is unqualified, and even if the adjustment component 17 is used for adjustment, the wafer 3 cannot be adsorbed; if not, it is within the allowable range, and the wafer 3 can still be used. Therefore, the adjustment component 17 is used to lift the suction cup 171 to adsorb the wafer 3.

[0076] The above embodiments are only for illustrating the technical concept and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it. They should not be used to limit the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A fork, characterized in that: The fork includes a connecting portion and a first finger, a second finger, and a third finger extending from the connecting portion, wherein the first finger, the second finger, and the third finger are located on the same side of the connecting portion, and the second finger is located between the first finger and the third finger; The first finger, the second finger, and the third finger are all provided with adsorption parts, wherein the line connecting the three adsorption parts forms a triangle for fixing wafers of different sizes. The projection of the smallest wafer on the fork covers the three adsorption parts. The end of the second finger away from the connecting part can abut against the teaching block for teaching. The fork extends into the loading lock chamber to pick up and place the wafer. The loading lock chamber is provided with two support pillars spaced apart along the second direction. The two support pillars are located between the first finger and the third finger, and the second finger is located between the two support pillars.

2. The fork according to claim 1, characterized in that: The adsorption section includes an air extraction hole and a first protrusion. The first protrusion is a closed-loop structure that forms an adsorption cavity. The air extraction hole is connected to the interior of the adsorption cavity, and the wafer is adsorbed onto the first protrusion.

3. The fork according to claim 2, characterized in that: The first boss is in contact with the wafer line; Or / and, the adsorption section includes a second protrusion located within the adsorption cavity, which contacts the wafer when the wafer is adsorbed.

4. The fork according to claim 3, characterized in that: When the adsorption portion includes the second protrusion, the second protrusion is in contact with the wafer line.

5. The fork according to claim 1, characterized in that: With reference to the connecting portion, among the first finger, the second finger, and the third finger, the second finger is the shortest relative to the connecting portion.

6. The fork according to claim 5, characterized in that: The first finger, the second finger, and the third finger are arranged sequentially along a second direction. Each adsorption portion includes a center line parallel to the second direction. The center of the wafer is located between the center line of the adsorption portion of the second finger and the center line of the adsorption portion of the first finger, and between the center line of the adsorption portion of the second finger and the center line of the adsorption portion of the third finger.

7. The fork according to claim 2, characterized in that: The number of air extraction holes in the adsorption section is equal; And / or, the first finger, the second finger and the third finger each include a finger body, each finger body is provided with the adsorption part, and is also the same thickness as the connecting part.

8. The fork according to any one of claims 2-4 or 7, characterized in that: The fork includes a detection component and an adjustment component. The detection component is used to detect the orientation of the wafer. The adjustment component includes a suction cup and a fine-tuning part. The fine-tuning part adjusts the height position of the suction cup according to the detection result of the detection component so that the suction cup can abut against the lower surface of the warped portion of the wafer.

9. The fork according to claim 8, characterized in that: The detection component and the adjustment component are provided at least part of the adsorption section, the adjustment component is located in the adsorption cavity, and the detection component is disposed on the first protrusion.

10. The fork according to claim 1, characterized in that: At least one of the tip of the second finger and the teaching block is provided with a sensing part, which is used for mutual sensing between the tip of the second finger and the teaching block.

11. A robotic arm, characterized in that: Includes the fork as described in any one of claims 1-10.

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