Large-size epitaxial silicon wafer taking mechanism

Abstract

A large-size epitaxial silicon wafer taking mechanism comprises a supporting arm and a suction cup connected to the end of the supporting arm through a connecting piece, a first channel connected with negative pressure equipment is arranged in the supporting arm, a second channel is arranged in the suction cup, the bottom side of the second channel penetrates through the bottom of the suction cup to adsorb an epitaxial silicon wafer, and the top side of the second channel is connected with the first channel through a connecting piece. The connecting piece comprises a ball socket fixed to the supporting arm and a ball head fixed to the suction cup and matched with the ball socket, an inner cavity of the ball socket is connected with the first channel, the ball head is provided with a first channel in a penetrating mode, the lower end of the first channel is connected with the second channel, and elastic pieces distributed downwards are fixedly arranged in the ball socket and located on the periphery of the third channel. The elastic piece can deform and clamp and fix the ball head after the first channel sucks the negative pressure. The method is used for further reducing point-point contact damage between the suction cup and the silicon wafer to be detected.

Description

Technical Field

[0001] The present invention relates to the field of epitaxial silicon wafer processing and production equipment, and specifically to a wafer picking mechanism for large-size epitaxial silicon wafers. Background Art

[0002] In the production and manufacturing of epitaxial silicon wafers, a wafer picking mechanism is required to transfer them between equipment such as preparation, cleaning, and detection. Existing wafer picking mechanisms usually include a support arm and a suction cup rigidly connected to the support arm. A channel is provided inside the suction cup. The top of this channel is connected to the channel in the support arm and ultimately to a negative pressure device. The bottom of this channel penetrates the bottom of the suction cup and is used to suck the silicon wafer. It is found during the trial that if the bottom of the suction cup fails to remain horizontal or the silicon wafer to be picked itself fails to be horizontal, when the support arm fits the suction cup towards the silicon wafer to be picked, there will be point-to-point contact between the bottom of the suction cup and the upper surface of the silicon wafer. Further, due to the rigid connection between the suction cup and the support arm, the pressure at the contact part is too large, resulting in impact or heavy pressure damage.

[0003] To solve the above technical problems, CN204966472U discloses a wafer picker for epitaxial production, in which the suction cup is movably connected to the support arm. During implementation, adaptive attitude adjustment is performed through the movable connection between the suction cup and the support arm to reduce the point-to-point contact damage between the lower edge of the suction cup and the silicon wafer to be picked.

[0004] However, in this technical solution, although the suction cup and the support arm are movably connected, the negative pressure channel between the suction cup and the support arm still needs to be sealed by two O-rings. However, even though the O-rings are flexible, when the lower edge of the suction cup and the silicon wafer are not parallel and there is point-to-point contact, the suction cup still transmits a large pressure to the silicon wafer through the support arm, still resulting in a certain degree of point-to-point contact damage. Summary of the Invention

[0005] The present invention aims to provide a wafer picking mechanism for large-size epitaxial silicon wafers to further reduce the point-to-point contact damage between the suction cup and the silicon wafer to be measured.

[0006] To solve the above technical problems, the specific solution adopted by the present invention is as follows: A wafer picking mechanism for large-size epitaxial silicon wafers includes a support arm and a suction cup connected to the end of the support arm through a connecting member. A first channel connected to a negative pressure device is provided in the support arm. A second channel is provided in the suction cup. The bottom side of the second channel penetrates the bottom of the suction cup to adsorb the epitaxial silicon wafer, and the top side is connected to the first channel through a connecting member. The connecting member includes a ball socket fixed on the support arm and a ball head fixed on the suction cup and cooperating with the ball socket. The inner cavity of the ball socket is connected to the first channel. The ball head is provided with a first channel with a lower end connected to the second channel. An elastic member distributed downward is fixedly provided on the outer periphery of the third channel in the ball socket. The elastic member can deform and clamp the ball head after the first channel sucks negative pressure.

[0007] Preferably, the ball head and the ball socket are in clearance fit.

[0008] Preferably, the elastic member is arranged at a position close to the top of the ball socket.

[0009] Preferably, the elastic member is in the shape of a sheet and there are multiple elastic members, and all the elastic members are evenly spaced along the circumferential direction of the inner wall of the ball socket.

[0010] Preferably, the elastic member is a continuous ring.

[0011] Preferably, the cross section of the elastic member is V-shaped. One side of the elastic member is a fixed side and is fixed to the inner wall of the ball socket, and the other side is a deformable side and is used to deform after the negative pressure is pumped in the first channel to clamp and fix the ball head.

[0012] Preferably, the length of the deformable side is greater than the gap between the outer edge of the ball head and the inner edge of the ball socket.

[0013] Preferably, the elastic member is made of silica gel.

[0014] In the present invention, the suction cup and the support arm are matched through the ball socket and ball head structure. After the suction cup and the epitaxial wafer to be picked are not parallel and the support arm drives the suction cup to move towards the wafer to be picked until point-to-point contact is achieved, the suction cup can automatically adjust the angle and buckle on the wafer to be picked to reach a surface-to-surface contact state. Then, after the negative pressure device is turned on, the elastic member can be automatically deformed by the negative pressure to clamp and fix the suction cup. On the one hand, this can avoid negative pressure leakage, and on the other hand, it can avoid the wafer from shaking during the transfer process, thereby avoiding scratches caused by friction.

[0015] During the above process, the elastic member only clamps and fixes the suction cup after the negative pressure is pumped. During the process of automatically adjusting the position of the suction cup before the negative pressure is pumped, it does not contact the ball head and the suction cup, so it will not generate resistance to the automatic adjustment process of the angle of the suction cup, and further will not apply too much pressure to the wafer to be measured during the point-to-point contact stage between the suction cup and the wafer to be picked, thereby greatly reducing the risk of point-to-point contact damage between the suction cup and the wafer to be measured. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic cross-sectional structure diagram of the present invention;

[0017] Figure 2 is Figure 1 a partially enlarged schematic structural diagram of the ball socket part in

[0018] Reference numerals in the figure: 1, the first channel; 2, the support arm; 3, the elastic member; 301, the fixed side; 302, the deformable side; 4, the ball socket; 5, the ball head; 6, the third channel; 7, the second channel; 8, the suction cup. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0019] AsFigure 1 and Figure 2 As shown in Figure 2 , a wafer picking mechanism for large-sized epitaxial wafers in the present invention is the same as a conventional wafer picking mechanism in that both include a support arm 2 and a suction cup 8 provided at the bottom right end of the support arm 2. The support arm 2 is usually connected to a robotic arm to move the suction cup 8 to various processing devices for epitaxial wafers. The support arm 2 is also connected to a negative pressure device and transmits negative pressure to the suction cup 8 to pick up the epitaxial wafer through the suction cup 8. Similar to the patented technology mentioned in the background art, the suction cup 8 in the present invention is movably linked to the support arm 2, realizing an adaptive adjustment of the angle of the suction cup 8. However, different from this patented technology, the resistance during the angle adjustment process of the suction cup 8 in the present invention is smaller, which can further reduce the risk of damage to the wafer to be picked. Specifically:

[0020] The suction cup 8 in the present invention is connected to the support arm 2 through a cooperating ball socket 4 and ball head 5 as a connecting member. A first channel 1 is provided in the support arm 2, the left end of which is connected to the negative pressure device and the right end is connected to the inner cavity of the ball head 5. A plurality of second channels 7 are provided in the suction cup 8, and the second channels 7 are evenly spaced along the circumferential direction of the suction cup 8. The lower end of any one of the second channels 7 penetrates through the bottom of the suction cup 8, and the upper ends converge and are connected to a third channel 6 provided in the ball head 5.

[0021] The outer diameter of the ball head 5 in the present invention is slightly smaller than the inner diameter of the ball socket 4. In the natural state, due to the gravity of the ball head 5 and the suction cup 8, the ball head 5 and the ball socket 4 are in the state as shown in Figure 1 , and at this time, a certain gap space is formed between the upper parts of the ball socket 4 and the ball head 5. An elastic member 3 with a V-shaped cross-section that is flipped by 90° is provided in this gap space. The elastic member 3 is a continuous ring made of silicone material. Its upper part forms a fixed side 301 and is fixedly connected to the inner surface of the ball socket 4 by screws or adhesives; its lower part covers the outer periphery of the upper part of the ball head 5. When the negative pressure device is not started, there is a certain gap between the bottom of the elastic member 3 and the ball head 5, and the two do not directly contact, so that the additional resistance will not be increased due to their contact when the suction cup 8 rotates adaptively. When the negative pressure device is started, since the length of the deformed side 302 is greater than the gap between the ball head 5 and the ball socket 4 at the corresponding position, the deformed side 302 cannot cross over the ball head 5 and tightly contact the upper part of the ball head 5 during the upward deformation due to negative pressure attraction, thereby isolating the first channel 1, the second channel 7, and the third channel 6 from the outside and maintaining the sealing of the negative pressure system.

[0022] It should be noted that in other embodiments of the present invention, the elastic member 3 can also be set to be non-continuous, for example, the structure formed by the circumferential interval missing of the elastic member 3 in the above embodiment. Through the above structure, even if there is a certain negative pressure leakage, it does not affect the picking of the wafer to be measured.​​

Claims

1. A large-size epitaxial silicon wafer taking mechanism, comprising a support arm (2) and a suction cup (8) connected to the end of the support arm (2) through a connecting piece, wherein a first channel (1) connected to a negative pressure device is provided in the support arm (2), a second channel (7) is provided in the suction cup (8), the bottom side of the second channel (7) is penetrated by the bottom of the suction cup (8) to absorb the epitaxial silicon wafer, and the top side is connected to the first channel (1) through a connecting piece, characterized in that: The connecting member comprises a ball socket (4) fixed on a support arm (2) and a ball head (5) fixed on a suction cup (8) and cooperating with the ball socket (4); the inner cavity of the ball socket (4) is connected to a first channel (1); the ball head (5) penetrates the first channel (1) whose lower end is connected to a second channel (7); an elastic member (3) distributed downward is fixedly provided on the outer periphery of a third channel (6) in the ball socket (4); the elastic member (3) can deform and clamp the fixed ball head (5) after negative pressure is sucked into the first channel (1).

2. A large-size epitaxial silicon wafer taking mechanism as claimed in claim 1, characterized in that: The ball head (5) and the ball socket (4) are clearance-matched.

3. A large-size epitaxial silicon wafer taking mechanism as claimed in claim 2, characterized in that: The elastic member (3) is arranged in the ball socket (4) at a position close to the top of the ball socket (4).

4. A large-size epitaxial silicon wafer taking mechanism as claimed in claim 1, characterized in that: The elastic member (3) is in the shape of a sheet and is in a plurality of pieces. All the elastic members (3) are evenly spaced and distributed along the circumference of the inner wall of the ball socket (4).

5. A large-size epitaxial silicon wafer taking mechanism as claimed in claim 1, characterized in that: The elastic member (3) is in the shape of a continuous ring.

6. A large-size epitaxial silicon wafer taking mechanism as claimed in claim 5, characterized in that: The cross section of the elastic member (3) is V-shaped, one side of the elastic member (3) is a fixed side (301) fixed to the inner wall of the ball socket (4), and the other side is a deformable side (302) and is used to deform after negative pressure is sucked into the first channel (1) to clamp and fix the ball head (5).

7. A large-size epitaxial silicon wafer taking mechanism as claimed in claim 6, characterized in that: The length of the deformed side (302) is greater than the gap between the outer edge of the ball head (5) and the inner edge of the ball socket (4).

8. A large-size epitaxial silicon wafer taking mechanism as claimed in claim 1, characterized in that: The elastic member (3) is made of silicone.

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