A wafer transmission method using an end effector

Abstract

The present invention discloses a wafer transmission method using an end effector, wherein the end effector includes a fork, the fork includes a fixed surface; a fixed claw, the fixed claw includes a first bearing portion protruding from a partial edge of the fixed surface to the inner cantilever; and a push claw, the push claw can move back and forth and includes a second bearing portion protruding to the inner cantilever close to the fixed surface. The wafer transmission method using the end effector includes: the end effector moves to the top of the wafer; the end effector moves downward until the first bearing portion and the second bearing portion are at least partially lower than the lower surface of the wafer; the end effector moves a first preset distance, at least a portion of the first bearing portion extends under the wafer; the push claw moves a second preset distance, at least a portion of the second bearing portion extends under the wafer; the end effector moves upward until the wafer is supported by the first bearing surface of the first bearing portion and the second bearing surface of the second bearing portion. The present invention can make the wafer less likely to deform during transmission.

Description

Technical Field

[0001] The present invention relates to the technical field of wafer handling equipment, and in particular to a wafer transmission method using an end effector. Background Art

[0002] Wafer transmission requires lossless handling. In related technologies, when a robot is handling wafers, an adsorption actuator or a clamping actuator is usually installed at the end of the robot. The adsorption actuator adsorbs the wafer on the upper surface of the fork of the adsorption actuator by vacuum adsorption, but this vacuum adsorption method will cause deformation and slight wear on the surface of the wafer. The clamping actuator usually lifts the wafer from bottom to top and fixes the wafer by clamping the circumference of the wafer. However, when a slightly warped wafer is clamped and the robot moves quickly, the clamping actuator may not clamp firmly and cause the wafer to fly out. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art to at least a certain extent. An embodiment of the present invention provides a wafer transmission method using an end effector, which can prevent the wafer from being easily deformed during the transmission process. At the same time, one end effector can move the wafer between the wafer box and the placement table.

[0004] In one embodiment, an end actuator includes: a fork, which includes a horizontal fixed surface; a fixed claw, which includes a first bearing portion that protrudes from a partial edge of the fixed surface to the inner cantilever, and the first bearing portion includes a first bearing surface; and a push claw, which can move reciprocatingly and includes a second bearing portion that protrudes to the inner cantilever close to the fixed surface, and the second bearing portion includes a second bearing surface, and the first bearing surface and the second bearing surface are both inclined surfaces, and the first bearing surface and the second bearing surface are inclined upward from a side close to each other to a side away from each other. The wafer transmission method using the end effector includes: a lifting step, which includes: S1, the end effector moves to the top of the wafer, at which time the projections of the first bearing part and the second bearing part on the horizontal plane do not overlap; S2, the end effector moves downward until the first bearing part and the second bearing part are at least partially lower than the lower surface of the wafer; S3, the end effector moves a first preset distance, at which time at least part of the first bearing part extends under the wafer, and the first preset distance is the sum of the standard distance and the offset value; S4, the push claw moves a second preset distance, at which time at least part of the second bearing part extends under the wafer, and the wafer is located between the bottom surface of the first bearing part and the second bearing part and the fixed surface; S5, the end effector moves upward until the wafer is supported by the first bearing surface and the second bearing surface.

[0005] Preferably, the fixing claw further comprises a first stop surface, and the first stop surface extends upward along a side of the first bearing surface away from the pushing claw.

[0006] More preferably, the pushing claw further includes a second stop surface, and the second stop surface extends upward along a side of the second bearing surface away from the fixing claw. In S4, a gap is allowed between the peripheral surface of the wafer and the second stop surface.

[0007] More preferably, the height position of the lower edge of the second bearing surface is lower than the height position of the lower edge of the first bearing surface.

[0008] More preferably, in S2, the end effector is moved downward until the first bearing part and the second bearing part are partially lower than the lower surface of the wafer, and the angle a1 between the first bearing surface and the horizontal plane is ≤30°, and the angle a2 between the second bearing surface and the horizontal plane is ≤30°.

[0009] In one embodiment, in S2, the end effector moves downward, and the first carrying surface and the second carrying surface are both lower than the lower surface of the wafer.

[0010] In one embodiment, two fixed claws are provided, and the two fixed claws are symmetrically arranged relative to a midline passing through the center of the push claw. The maximum angle between the line connecting the fixed claw and the center of the wafer and the midline is not greater than 57°, and the minimum angle between the line connecting the fixed claw and the center of the wafer and the midline is not less than 30°.

[0011] In one embodiment, the push claw further includes a connecting portion located above the second bearing portion, the connecting portion is a conical structure around the vertical rotation axis, and the side surface of the connecting portion is an arc surface recessed toward the inner side of the connecting portion.

[0012] In one embodiment, the wafer transfer method of the end effector further includes a placement step, and the placement step includes:

[0013] S6, the end effector moves to the top of the placement table;

[0014] S7, the end effector descends until the wafer is supported by the placement table;

[0015] S8, the pushing claw moves in a direction away from the fixed claw, and the second supporting part is pulled away from below the wafer;

[0016] S9, moving the end effector to withdraw the first supporting part from below the wafer until the projections of the first supporting part and the wafer on the horizontal plane do not overlap, and at this time, the projections of the second supporting part and the wafer on the horizontal plane do not overlap;

[0017] S10, the end effector moves upward and away from the placement table. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A bottom view of an embodiment of the present invention;

[0019] Figure 2 A front view of an embodiment of the present invention;

[0020] Figure 3 for Figure 2 Enlarged view of point A in the middle;

[0021] Figure 4 for Figure 2 Enlarged view of point B in the middle;

[0022] Figure 5 It is a schematic diagram of the three-dimensional structure of a fixing claw in one embodiment of the present invention;

[0023] Figure 6 A top view of a fixing claw in one embodiment of the present invention;

[0024] Figure 7 for Figure 6 Sectional view along line DD;

[0025] Figure 8 A front view of a push claw in one embodiment of the present invention;

[0026] Fig. 9 for Figure 8 The enlarged view of point C in the figure;

[0027] Fig.10 A top view of a push claw in an extended state according to an embodiment of the present invention;

[0028] Fig.11 FIG. 1 is a top view of a push claw in a retracted state according to an embodiment of the present invention.

[0029] In the figure:

[0030] 1. Slice fork;

[0031] 1a, fixed surface; 11, root; 111, clearance gap; 12, finger part;

[0032] 2. Fixed claw; 2a. First fixed claw; 2b. Second fixed claw;

[0033] 21, fixing portion; 211, first stop surface; 212, fixing hole; 22, first bearing portion; 221, first bearing surface;

[0034] 3. Push claw;

[0035] 311, second stop surface; 32, second bearing portion; 321, second bearing surface; 33, connecting portion;

[0036] 4. Middle line;

[0037] 5. Connecting frame;

[0038] 6. Wafer. DETAILED DESCRIPTION

[0039] The preferred embodiments of the present invention are described in detail below in conjunction with 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 making a clearer and more definite definition of the protection scope of the present invention.

[0040] In each of the drawings, left and right and front and back indicate two horizontal directions that are orthogonal to each other, and up and down indicate vertical directions.

[0041] An end effector according to an embodiment of the present invention is used for taking and placing a wafer 6 in a horizontal state, wherein the wafer 6 includes an upper surface, a lower surface and a side surface (circumferential surface). Figure 1 As shown, the end effector includes a fork 1, a fixed claw 2 and a push claw 3.

[0042] See also Figure 2 and Figure 3 As shown, the lower surface of the blade fork 1 is a fixing surface 1a, the fixing surface 1a is maintained in a horizontal posture, and the fixing claw 2 is fixed on the fixing surface 1a.

[0043] See also Figure 2 , Figure 3 and Figure 7 As shown, the fixing claw 2 includes a first bearing portion 22 that protrudes from a portion of the edge of the fixing surface 1a to the inner side of the cantilever. Figure 5 As shown, the fixing claw 2 includes a fixing portion 21 and a first bearing portion 22 located below the fixing portion 21. The fixing portion 21 is connected to the edge of the fixing surface 1a of the fork 1. The first bearing portion 22 protrudes from the edge of the fixing surface 1a to the inner side of the fixing surface 1a. The upper surface of the first bearing portion 22 is a first bearing surface 221.

[0044] like Figure 2 , Figure 4 , Figure 8 and Fig. 9 As shown, the push claw 3 includes a second bearing portion 32 cantilevered and protruding toward the inner side of the fixing surface 1a. The second bearing portion 32 is arranged below the fixing surface 1a at intervals and protrudes toward the fixing surface 1a. The upper surface of the second bearing portion 32 is a second bearing surface 321.

[0045] Attached Fig.10 A top view of the push claw 3 in the extended state is shown. Fig.11 The top view of the retracted state of the push claw 3 is shown. The push claw 3 can be driven by a cylinder and a motor, and the push claw 3 can move toward and away from the fixed claw 2.

[0046] The end effector can be connected to the robot arm. When the wafer 6 needs to be picked up, it can be achieved by the following steps:

[0047] S1 . The end effector moves to the position directly above the wafer 6 . At this time, the projections of the first supporting portion 22 and the second supporting portion 32 on the horizontal plane do not overlap with the projections of the wafer 6 .

[0048] In this step, it should be noted that directly above the wafer 6 means that when the end effector is above the wafer 6 , the projections of the end effector and the wafer 6 on the horizontal plane at least partially overlap.

[0049] In this step, the push claw 3 is located in the retracted position on the left side, which ensures that the fixed claw 2 passes the wafer 6 and is located on the right side of the wafer 6. At the same time, the push claw 3 is also on the left side of the wafer 6. In other words, the projections of the first supporting part 22 and the second supporting part 32 and the wafer 6 on the horizontal plane do not overlap.

[0050] S2 , the end effector moves downward until the first carrying portion 22 and the second carrying portion 32 are at least partially below the lower surface of the wafer 6 .

[0051] Since the projections of the first carrying portion 22 and the second carrying portion 32 on the horizontal plane do not overlap with the wafer 6 , when the end effector moves downward, the first carrying portion 22 and the second carrying portion 32 do not interfere with the wafer 6 .

[0052] The first bearing surface 221 of the first bearing part 22 and the second bearing surface 321 of the second bearing part can be different types of surfaces, for example, they can be planes or inclined surfaces. When the first bearing surface 221 and the second bearing surface 321 are planes, the first bearing part 22 and the second bearing part 32 are completely located below the wafer 6. At this time, in order to prevent the fixed surface 1a from contacting and colliding with the wafer 6 when the end effector moves downward, the spacing between the first bearing surface 221 and the second bearing surface 321 and the fixed surface 1a is greater than the thickness of the wafer 6. When the first bearing surface 221 and the second bearing surface 321 are inclined surfaces, the first bearing part 22 and the second bearing part 32 can be completely located below the wafer 6, or can be partially located below the wafer 6.

[0053] S3, the end effector moves a first preset distance, at which point at least a portion of the first bearing portion 22 extends under the wafer 6. The end effector moves leftward by a first preset distance, at which point the fixed claw 2 moves leftward along with the end effector, and at least a portion of the first bearing portion 22 of the fixed claw 2 extends under the wafer 6, that is, the edge of the wafer 6 partially overlaps with the projection of the first bearing surface 221 on the horizontal plane.

[0054] S4, the push claw moves a second preset distance, at this time at least part of the second bearing part 32 extends under the wafer 6, and the wafer 6 is located between the bottom surface of the first bearing part 22 and the second bearing part 32 and the fixing surface 1a. At this time, the wafer 6 is confined in the cavity formed by the fork, the fixing claw 2 and the push claw 3. The position of the push claw 3 after moving the second preset distance can be seen in Fig.10The top view of the push claw 3 in the extended state is shown.

[0055] S5 , the end effector moves upward until the wafer 6 is supported by the first carrying surface 221 of the first carrying portion 22 and the second carrying surface 321 of the second carrying portion 32 . Figure 2 The figure shows a state where the wafer 6 is supported by the first carrying surface 221 of the first carrying portion 22 and the second carrying surface 321 of the second carrying portion 32 . At this time, the wafer 6 is confined in the cavity formed by the fork, the fixing claw 2 and the pushing claw 3 .

[0056] In this way, the wafer 6 can be carried out.

[0057] The adsorption type actuator of the related technology will generate an adsorption force on the wafer 6, which causes the wafer 6 to deform. At the same time, when the adsorption type actuator grabs and places the warped wafer 6, it is easy for the adsorption type actuator to have a loose adsorption due to the flatness problem of the warped wafer 6. The existing clamping type actuator needs to fix the wafer 6 by clamping the circumference of the wafer 6. Since the projection of the warped wafer 6 on the horizontal plane is roughly elliptical, when a slightly warped wafer 6 is clamped, the clamping may fail or be loose, and it is also easy for the wafer 6 to undergo elastic deformation. During the movement of the robot, the warped wafer 6 may easily slip and fly out of the robot, making it impossible to effectively pick up and place the warped wafer 6.

[0058] The end effector in this embodiment will not clamp the wafer 6 during the carrying step. The wafer 6 is only supported on the first supporting surface 221 and the second supporting surface 321 by gravity. The wafer 6 does not need to be adsorbed or supported during the carrying process. Therefore, the wafer 6 is not easily deformed, and the warped wafer 6 can be taken and placed.

[0059] The existing adsorption-type actuator and clamping-type actuator are used to take the wafer 6 from the bottom of the wafer 6. The forks of the adsorption-type actuator and the clamping-type actuator are located below the wafer 6. After the robot takes out the wafer 6 from the wafer box, the wafer 6 cannot be placed directly on the placement table due to the obstruction of the fork. The placement table can be a placement table at the process machine, or it can be other platforms where the wafer needs to be placed. Therefore, when placing the wafer 6 from the wafer box on the placement table on the process machine, two robots are required to carry the wafer 6. One robot uses a clamping-type actuator or an adsorption-type actuator to lift the wafer 6 from the wafer box and move it from the wafer box at the EFEM to the process machine. The process machine also needs another robot to use an adsorption-type actuator to suck the upper surface of the wafer 6 before placing the wafer 6 on the placement table of the process machine. During this process, the adsorption-type actuator of the other robot of the process machine will cause the surface of the wafer 6 to deform. The wafer bonding process has high requirements on the wafer surface. The wafers obtained by the two manipulator transmission method have large deformation on the wafer surface, making it difficult to bond during the wafer bonding process.

[0060] In the end effector of the present embodiment, the fork 1 is located above the first carrying surface 221 and the second carrying surface 321. The end effector picks up the wafer 6 from above using the first carrying surface 221 and the second carrying surface 321. The fork 1 is located above the wafer 6. The fork 1 above the wafer 6 will not interfere with the placement table of the process machine. Therefore, a single robot with the end effector of the present application can place the wafer 6 in the wafer box directly on the placement table at the process table, which not only saves another robot, but also makes the wafer 6 less likely to deform during transportation, thereby avoiding the situation where the bonding failure of the wafer 6 during the wafer bonding process due to large deformation of the surface of the wafer 6.

[0061] In one embodiment, see the attached Figure 7 and attached Fig. 9 As shown, the first bearing surface 221 and the second bearing surface 321 are both inclined surfaces, and the first bearing surface 221 and the second bearing surface 321 are inclined in opposite directions, and the first bearing surface 221 and the second bearing surface 321 are inclined upward from the side close to each other to the side away from each other. The first bearing surface 221 is inclined downward toward the side of the push claw 3, and the second bearing surface 321 is inclined downward toward the side of the fixed claw 2. At this time, the first bearing surface 221 and the second bearing surface 321 only abut against the edge of the lower surface of the wafer 6, and are not in surface contact with the wafer 6, but in line contact, which reduces the contact area between the end effector and the wafer 6, and effectively reduces the contamination of the wafer 6.

[0062] In one embodiment, see the attached Figure 7 As shown, the angle between the first bearing surface 221 and the horizontal plane is a1, a1≤81°, see the attached Fig. 9 As shown, the included angle between the second bearing surface 321 and the horizontal plane is a2, a2≤81°.

[0063] Preferably, the fixing claw 2 further includes a first stop surface 211 , and the first stop surface 211 extends upward along a side of the first bearing surface 221 away from the pushing claw 3 , and the first preset distance is the sum of the standard distance and the offset value.

[0064] It should be understood that the standard distance refers to the distance that the first supporting portion 22 extends under the wafer 6 when the end effector moves toward the side opening of the wafer 6 box when the wafer 6 is placed in a standard manner in the wafer 6 box.

[0065] The offset value refers to the distance that the end effector moves further toward the side opening of the wafer 6 box based on the standard moving distance. The offset value is greater than or equal to the maximum deviation distance value of the wafer 6. The deviation distance value refers to the distance between the actual placement position of the wafer 6 and the standard position of the wafer 6 placed in the wafer 6 box in a standard manner.

[0066] Although the placement position of wafer 6 in the wafer box is most likely to be near the standard position, there is a small probability that wafer 6 will deviate from the standard position to a large extent. For example, when wafer 6 is located closer to the side opening of the wafer box, after the end effector moves a standard distance toward the side opening of the wafer box, the first supporting portion 22 may not extend under the wafer 6. At this time, the end effector cannot correctly support the wafer 6.

[0067] In step S3, the first preset distance is set to the sum of the standard distance and the offset value, which can ensure that the first supporting portion 22 extends into the lower surface of the wafer 6. Even if the wafer 6 deviates toward the side opening of the wafer box, the end effector can still hold the wafer 6.

[0068] When the actual placement position of wafer 6 is at the standard position or at the opening away from the side of the wafer box, in step S3, when the end effector moves at a first preset distance, the first supporting portion 22 will completely extend under the wafer 6, and the first stop surface 211 pushes the circumference of the wafer 6 to move the wafer 6 toward the side opening of the wafer box. At this time, there is no gap between the first stop surface 211 and the circumference of the wafer 6. In the process of taking the wafer 6 out of the wafer box, the wafer 6 will not move relative to the fixing claw 2.

[0069] More preferably, the push claw 3 further includes a second stop surface 311, which extends upward along the side of the second bearing surface 321 away from the fixed claw 2. In S4, a gap is allowed between the circumference of the wafer 6 and the second stop surface 311. In this way, it is possible to prevent the second stop surface 311 from directly clamping the circumference of the wafer 6 and causing the wafer 6 to deform. When the wafer 6 is moved quickly, the wafer 6 is located in the cavity formed by the fork, the fixed claw 2 and the push claw 3. When the wafer 6 slides along the tiny gap, the wafer 6 will not fall out of the cavity and fall due to the stop of the second stop surface 311.

[0070] When the end effector moves by the first preset distance which is the sum of the standard distance and the offset value, the wafer 6 tends to deviate to the side of the fixed claw 2. In other words, when the step S4 is executed and the push claw 3 moves by the second preset distance, the position of the wafer 6 is closer to the fixed claw 2. At this time, the edge of the lower surface of the wafer 6 will abut against the first bearing surface 221, and the second bearing surface 321 of the second bearing portion 32 does not contact the edge of the lower surface of the wafer 6. When the step S5 is executed and the end effector is moved upward, the edge of the lower surface of the wafer 6 abuts against the second bearing surface 321. At this time, the first position where the wafer 6 contacts the first bearing surface 221 is higher than the second position where the wafer 6 contacts the second bearing surface 321. The wafer 6 deflects on the end effector, and the distance between the lower edge of the second bearing surface 321 and the second position is smaller than the distance between the lower edge of the first bearing surface 221 and the first position.

[0071] In the process of executing step S2 and moving the end effector downward, in order to avoid the upper surface of the wafer 6 from contacting and colliding with the fixed surface 1a of the fork 1, a gap is allowed between the upper surface of the wafer 6 and the fixed surface 1a of the fork 1. In the space formed by the fork 1, the fixed claw 2 and the push claw 3, the wafer 6 has more sliding space in the inclined direction than in the horizontal direction. When the end effector moves quickly and the gap between the lower edge of the second bearing surface 321 and the second position is smaller than the gap between the lower edge of the first bearing surface 221 and the first position, the wafer 6 slides and easily falls from the push claw 3 position and breaks.

[0072] To this end, more preferably, the height position of the lower edge of the second bearing surface 321 is lower than the height position of the lower edge of the first bearing surface 221. In this way, after the end effector moves by the first preset distance that is the sum of the standard distance and the offset value, the distance between the lower edge of the second bearing surface 321 and the second position will not be too short, thereby preventing the wafer 6 from sliding and falling from the position of the push claw 3 and breaking during the process of the end effector picking up the wafer 6 and moving.

[0073] When executing step S2, there is a movement error in the downward process of the end effector. In order to ensure that the fixing surface 1a of the fork 1 does not contact and collide with the upper surface of the wafer 6, a certain margin of distance is usually left between the upper surface of the wafer 6 and the fixing surface 1a. When the distance between the upper surface of the wafer 6 and the fixing surface 1a is too large, the size of the end effector in the up and down directions will increase, and the end effector will find it difficult to enter the narrow interlayer space of the wafer box, making it difficult to lift and remove the wafer 6 in the wafer box.

[0074] To this end, more preferably, in S2, the end effector is moved downward until the first bearing portion 22 and the second bearing portion 32 are partially below the lower surface of the wafer 6, and the angle a1 between the first bearing surface 221 and the horizontal plane is ≤30°, and the angle a2 between the second bearing surface 321 and the horizontal plane is ≤30°.

[0075] During the execution of step S2, the end effector is moved downward until the first bearing part 22 and the second bearing part 32 are partially lower than the lower surface of the wafer 6. At this time, the lower surface of the wafer 6 can be located within the middle section of the inclined surface of the first bearing part 22 and the second bearing part 32, and a gap is left between the upper surface of the wafer 6 and the fixing surface 1a to avoid contact between the upper surface of the wafer 6 and the fixing surface 1a. Then, step S3 is executed. Since the angle a1 between the first bearing surface 221 and the horizontal plane is a gentle angle, the wafer 6 can slide smoothly along the first bearing surface 221 and further extend under the wafer 6. Then, step S4 is executed. The wafer 6 can slide smoothly along the second bearing surface 321 and further extend under the wafer 6. In this process, the wafer 6 can be translated upward using the reserved gap, thereby achieving the support of the edge of the lower surface of the wafer 6 by the first bearing surface 221 and the second bearing surface 321.

[0076] When executing step S2, since there is no need to reserve an additional error dimension for the end effector to move downward in the distance between the upper surface of the wafer 6 and the fixed surface 1a, the end effector of this embodiment has a smaller size in the up and down directions, and the end effector can extend into the narrow interlayer space in the wafer box to take and place the wafer 6.

[0077] In one embodiment, in S2, the end effector moves downward, and the first bearing surface 221 and the second bearing surface 321 are both lower than the lower surface of the wafer 6. In this way, when performing steps S3 and S4, the first bearing surface 221 and the second bearing surface 321 do not contact the wafer 6, which can prevent the first bearing surface 221 or the second bearing surface 321 from being broken due to the large force when the first bearing surface 221 or the second bearing surface 321 is rough or has a large slope.

[0078] In this embodiment, there is no limitation on the types of the first bearing surface 221 and the second bearing surface 321 . For example, the first bearing surface 221 and the second bearing surface 321 may be horizontal surfaces or inclined surfaces.

[0079] In one embodiment, the first supporting surface 221 is an arc surface matching the edge of the wafer 6 .

[0080] Specifically, the first bearing surface 221 extends along a partial edge of the wafer 6 opposite to the push claw 3, and the first bearing surface 221 has a first end and a second end in a radial direction perpendicular to the wafer 6, and the first end and the second end of the first bearing surface 221 are respectively located on both sides of the line connecting the push claw 3 and the center of the wafer 6.

[0081] At this time, when the first carrying surface 221 carries the wafer 6 , the contact range between the wafer 6 and the first carrying surface 221 is larger, which can provide more stable support for the wafer 6 .

[0082] In one embodiment, two fixing claws 2 are provided, and the two fixing claws 2 are symmetrically arranged relative to a center line 4 passing through the center of the push claw 3. The maximum angle a4 between the line connecting the fixing claw 2 and the center of the wafer 6 and the center line 4 is not greater than 57°, and the minimum angle a3 between the line connecting the fixing claw 2 and the center of the wafer 6 and the center line 4 is not less than 30°.

[0083] It should be noted that the center line 4 is a straight line passing through the center of a circle defined by the push claw 3 and the fixed claw 2 .

[0084] The maximum angle between the line connecting the fixed claw 2 and the center of the wafer 6 and the center line 4 is set to be no greater than 57°, which can avoid interference between the fixed claw 2 and the spacing protrusions supporting the wafer 6 in the wafer 6 box. The minimum angle between the line connecting the fixed claw 2 and the center of the wafer 6 and the center line 4 is set to be no less than 30°, which can avoid the fixed claw 2 protruding out of the wafer 6 away from the opening side of the wafer 6 box, thereby avoiding interference between the end effector and the inner wall opposite to the opening of the wafer 6 box when taking and placing the wafer 6.

[0085] In one embodiment, the push claw 3 further includes a connecting portion 33 located above the second bearing portion 32 . The connecting portion 33 is a conical structure around a vertical rotation axis. The side surface of the connecting portion 33 is an arc surface recessed toward the inside of the connecting portion 33 .

[0086] The concave arc surface can prevent dust from falling, and can prevent the push claw 3 from dropping dust on the wafer 6 during movement and causing pollution to the wafer 6. At the same time, the inward concave surface can reduce the weight of the push claw 3, reduce the inertia of the push claw 3 and the deflection deformation of the cantilever of the driving member.

[0087] In one embodiment, the end effector further includes a connecting frame 5 and a driving member connected to the connecting frame 5 . The connecting frame 5 is rotatably connected to the pushing claw 3 , and the driving member can drive the pushing claw 3 to move back and forth.

[0088] When executing step S4, the push claw 3 pushes the wafer 6 to move toward the fixed claw 2. The push claw 3 and the two fixed claws 2 can position the wafer 6. When the wafer 6 is slightly tilted relative to the end effector, the push claw 3 is rotatably connected to the connecting frame 5. The rotatable push claw 3 can push the wafer 6 to the position where the push claw 3 and the two fixed claws 2 position the wafer 6 with a relatively small friction force, thereby preventing the driving component from being subjected to a force perpendicular to the moving direction of the driving component due to large friction, thereby ensuring the movement accuracy of the driving component.

[0089] The driving member may be a cylinder rod or a telescopic rod driven by a motor. This embodiment does not limit the type of the driving member.

[0090] When the driving member moves the push claw 3 via the connecting frame 5 , in order to avoid interference between the connecting frame 5 and the sheet fork 1 , in one embodiment, a clearance notch 111 opening toward the push claw 3 is provided at one end of the sheet fork 1 close to the push claw 3 .

[0091] After taking out the wafer 6 from the inner tray of the wafer 6 box, when the wafer 6 needs to be placed on the placement table, the following steps can be performed:

[0092] S6. The end effector moves to the position directly above the placement table.

[0093] In this step, it should be noted that directly above the placement table means that when the end effector is above the placement table, the projection of the wafer 6 on the end effector and the placement table on the horizontal plane at least partially overlap.

[0094] S7 . The end effector descends until the wafer 6 is supported by the placement table.

[0095] At this time, the wafer 6 is carried by the placement table, away from the first carrying surface 221 and the second carrying surface 321 , and does not contact the wafer fork 1 .

[0096] S8 , the pushing claw 3 moves in a direction away from the fixing claw 2 , and the second carrying portion 32 is withdrawn from below the wafer 6 .

[0097] At this time, the push claw 3 is located at the retracted position, and the projections of the push claw 3 and the wafer 6 on the horizontal plane do not overlap.

[0098] S9, moving the end effector to withdraw the first carrying part 22 from below the wafer 6 until the projections of the first carrying part 22 and the wafer 6 on the horizontal plane do not overlap, and at this time, the projections of the second carrying part 32 and the wafer 6 on the horizontal plane do not overlap.

[0099] S10, the end effector moves upward and away from the placement table.

[0100] Steps S1 to S10 complete the placement and removal of a wafer 6 , and steps S1 to S10 are repeated to achieve the transfer of all wafers 6 between the wafer box and the placement table.

[0101] It can be seen from the above-mentioned transport method that one robot can be used to transport the wafer 6 in the wafer box to the placement table of the process table, which not only saves another robot, but also makes the wafer 6 less likely to deform during the transmission process, thereby avoiding the situation where the bonding failure of the wafer 6 during the wafer 6 bonding process is caused by large deformation of the surface of the wafer 6.

[0102] Considering the warping of the wafer 6, the thickness error of the wafer 6 and the reserved gap to avoid the upper surface of the wafer 6 from colliding with the fixing surface 1a, in one embodiment, the dimension d2 of the first stop surface 211 in the vertical direction is greater than 0.9 mm. The dimension d1 between the upper surface of the wafer 6 and the fixing surface 1a is greater than 0.15 mm.

[0103] To prevent the fixing claw 2 from interfering with the bottom of the wafer box side opening when the end effector moves and to facilitate the picking up of the wafer 6, in one embodiment, the distance d3 of the first bearing portion 22 protruding from the fixing portion 21 satisfies 0.5mm≤d3≤4mm. Preferably, d3=1mm.

[0104] In one embodiment, the slice fork 1 includes a root 11 and two finger portions 12 extending along the root 11 toward the fixed claw 2, and the two finger portions 12 are arranged at intervals in a direction perpendicular to the movement of the push claw 3. The two finger portions 12 have the same length, so that the slice fork 1 is a U-shaped structure as a whole. The end of the finger portion 12 away from the push claw 3 is a limiting portion, and the fixed claw 2 is connected to the limiting portion. Figure 6 As shown, a fixing hole 212 is formed on the fixing portion 21 of the fixing claw 2 , and the fixing claw 2 is fixed to the limiting portion of the blade fork 1 by a fixing member passing through the fixing hole 212 .

[0105] Considering the travel of the driving member that pushes the claw and the convenience of holding the wafer 6, in one embodiment, the cantilever protrusion distance d4 of the second carrying portion 32 satisfies 0.5mm≤d4≤4mm. Preferably, d4=1mm.

[0106] The above implementation modes 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, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A wafer transfer method using an end effector, characterized in that: The end effector comprises: a slice fork, the slice fork comprising a horizontal fixing surface; A fixing claw, the fixing claw comprising a first bearing portion cantilevered inwardly from a portion of an edge of the fixing surface, the first bearing portion comprising a first bearing surface; and A push claw, the push claw can move back and forth, and includes a second bearing portion cantilevered protruding toward the inner side of the fixed surface, the second bearing portion includes a second bearing surface, the first bearing surface and the second bearing surface are both inclined surfaces, and the first bearing surface and the second bearing surface are inclined upward from a side close to each other to a side away from each other; the method includes a lifting step, and the lifting step includes: S1, the end effector moves to the position directly above the wafer, at which point the projections of the first supporting part and the second supporting part on the horizontal plane do not overlap with the wafer; S2, the end effector moves downward until the first bearing portion and the second bearing portion are at least partially lower than the lower surface of the wafer; S3, the end effector moves a first preset distance, at which time at least a portion of the first bearing portion extends under the wafer, the first preset distance being the sum of a standard distance and an offset value, the standard distance being the distance that the end effector moves toward the side opening of the wafer box so that the first bearing portion extends under the wafer when the wafer is placed in a standard manner in the wafer box, and the offset value being the distance that the end effector further moves toward the side opening of the wafer box on the basis of moving the standard distance; S4, the pushing claw moves a second preset distance, at which time at least a portion of the second carrying portion extends under the wafer, and the wafer is located between the bottom surfaces of the first carrying portion and the second carrying portion and the fixing surface; S5. The end effector moves upward until the wafer is supported by the first carrying surface and the second carrying surface.

2. The wafer transfer method using an end effector according to claim 1, characterized in that: The fixing claw further comprises a first stop surface, and the first stop surface extends upward along a side of the first bearing surface away from the pushing claw.

3. The wafer transfer method using an end effector according to claim 2, characterized in that: The pushing claw further includes a second stop surface, and the second stop surface extends upward along a side of the second bearing surface away from the fixing claw. In S4, a gap is allowed between the peripheral surface of the wafer and the second stop surface.

4. The wafer transfer method using an end effector according to claim 1, characterized in that: The height position of the lower edge of the second bearing surface is lower than the height position of the lower edge of the first bearing surface.

5. The wafer transfer method using an end effector according to claim 1, characterized in that: In S2, the end effector is moved downward until the first bearing portion and the second bearing portion are partially lower than the lower surface of the wafer, and an angle a1 between the first bearing surface and the horizontal plane is ≤30°, and an angle a2 between the second bearing surface and the horizontal plane is ≤30°.

6. The wafer transfer method using an end effector according to claim 1, characterized in that: In S2, the end effector moves downward, and the first carrying surface and the second carrying surface are both lower than the lower surface of the wafer.

7. The wafer transfer method using an end effector according to claim 1, characterized in that: There are two fixed claws, and the two fixed claws are symmetrically arranged relative to a midline passing through the center of the pushing claw. The maximum angle between the line connecting the fixed claw and the center of the wafer and the midline is not greater than 57°, and the minimum angle between the line connecting the fixed claw and the center of the wafer and the midline is not less than 30°.

8. The wafer transfer method using an end effector according to claim 1, characterized in that: The push claw further includes a connecting portion located above the second bearing portion, the connecting portion is a conical structure around a vertical rotation axis, and a side surface of the connecting portion is an arc surface recessed toward the inner side of the connecting portion.

9. The wafer transfer method using an end effector according to claim 1, characterized in that: The method further comprises a placing step, wherein the placing step comprises: S6, the end effector moves to the position directly above the placement table; S7, the end effector descends until the wafer is supported by the placement table; S8, the pushing claw moves in a direction away from the fixing claw, and the second carrying part is pulled away from below the wafer; S9, moving the end effector to withdraw the first supporting part from below the wafer until the projections of the first supporting part and the wafer on the horizontal plane do not overlap, and at this time, the projections of the second supporting part and the wafer on the horizontal plane do not overlap; S10, the end effector moves upward and away from the placement platform.

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