Bernoulli chuck capable of adsorbing ultrathin wafer

Abstract

The invention belongs to the technical field of wafer manufacturing equipment manufacturing, and particularly relates to a Bernoulli sucker capable of adsorbing an ultrathin wafer, the Bernoulli sucker comprises a base plate, an upper cover and a gasket, the upper surface of the base plate is coaxially provided with a concave cavity, the base plate is provided with an air inlet device communicated with the concave cavity, the lower surface of the upper cover is coaxially provided with a bulge, the upper cover covers the concave cavity, the bulge is coaxial with the concave cavity, and the gasket is arranged in the concave cavity. A gap is preset between the circumferential face of the protrusion and the inner circumferential face of the concave cavity, an annular groove is coaxially formed in the upper surface of the upper cover, a chamfer is arranged at the opening of the annular groove, and the projection of the annular groove on the lower surface of the upper cover is located in the projection of the protrusion on the lower surface of the upper cover. At least four through holes are formed in the circumferential wall of the protrusion around the central axis of the upper cover in a circumferential array mode, the ends, facing the central axis of the upper cover, of the through holes are communicated with the annular groove, a plurality of gaskets are arranged on the outer circumference of the annular groove in an array mode, and the problem how to adopt a positive pressure device to be matched with the upper cover and the base plate to achieve adsorption of the ultrathin wafer is solved.

Description

Technical Field

[0001] This application belongs to the field of wafer manufacturing equipment technology, specifically a Bernoulli chuck that can adsorb ultra-thin wafers. Background Technology

[0002] In the wafer manufacturing process, very thin wafers need to be held in place, typically using chucks. Traditional chucks provide negative pressure to force the wafer to adhere tightly to the chuck's opening, which can damage the wafer when handling ultra-thin wafers. Summary of the Invention

[0003] The purpose of this application is to address the shortcomings of existing technologies by designing a Bernoulli suction cup that can adsorb ultra-thin wafers using Bernoulli's principle. By applying positive pressure, a fixed suction force is created on the top cover. At the same time, the wafer is in a floating state when adsorbing it, thus preventing the wafer from being broken. This solves the problem of how to adsorb ultra-thin wafers.

[0004] The above-mentioned technical objective of this application is achieved through the following technical solution: A Bernoulli suction cup capable of adsorbing ultrathin wafers includes a base, a top cover, and gaskets. The upper surface of the base has a coaxial cavity, and an air intake device communicating with the cavity is provided on the base. The lower surface of the top cover has a coaxial protrusion, which closes onto the cavity. The protrusion is coaxial with the cavity, and a predetermined gap exists between the circumferential surface of the protrusion and the inner circumferential surface of the cavity. The upper surface of the top cover has a coaxial annular groove, with a chamfer at the opening. The projection of the annular groove onto the lower surface of the top cover lies within the projection of the protrusion onto the lower surface of the top cover. At least four through holes are circumferentially arranged around the central axis of the top cover on the circumferential wall of the protrusion. One end of each through hole facing the central axis of the top cover communicates with the annular groove. A predetermined distance exists between the projection of the central axis of the through hole onto the upper surface of the top cover and the center of the top cover. Several gaskets are circumferentially arranged around the annular groove on the upper surface of the top cover, with a predetermined gap between any two adjacent gaskets.

[0005] Preferably, the height of the gasket is 0.2 mm and the diameter of the through hole is 1 mm.

[0006] Preferably, the air intake device includes an air intake channel, which is coaxially provided through the bottom wall of the concave cavity, and an auxiliary cavity is coaxially provided on the protrusion. The opening of the auxiliary cavity faces downward, and an airflow channel is provided on the side wall of the auxiliary cavity. One end of the airflow channel facing away from the auxiliary cavity extends to the circumferential surface of the protrusion.

[0007] Preferably, a first sealing ring mounting groove is provided coaxially outside the cavity on the upper surface of the chassis.

[0008] Preferably, a second sealing ring mounting groove is coaxially provided on the inner bottom wall of the cavity, the projection of the air intake channel on the inner bottom wall of the cavity is within the annulus formed by the second sealing ring mounting groove, and the projection of the auxiliary cavity on the inner bottom wall of the cavity is within the annulus formed by the second sealing ring mounting groove.

[0009] Preferably, a first screw hole is provided through the lower surface of the chassis, and a second screw hole is provided on the lower surface of the upper cover to mate with the first screw hole. The second screw hole is a blind hole. After the bolt passes through the first screw hole, it is threadedly connected to the second screw hole. The projections of the first screw hole and the second screw hole on the lower surface of the cavity are located between the auxiliary cavity and the second sealing ring mounting groove. The projections of the first screw hole and the second screw hole on the lower surface of the cavity are located between the air intake channel and the second sealing ring mounting groove.

[0010] The beneficial effects of this application are: This application utilizes Bernoulli's principle to design a Bernoulli suction cup capable of adsorbing ultrathin wafers. By applying positive pressure, a fixed suction force is generated on the top cover. Simultaneously, the wafer is in a floating state when adsorbing it, thus preventing the wafer from being broken. This solves the problem of how to adsorb ultrathin wafers. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the structure of this application; Figure 2 This is a cross-sectional view of this application; Figure 3 This is an exploded view of this application; Figure 4 for Figure 3 A schematic diagram of the bottom structure; Figure 5 This is a schematic diagram illustrating the structure of the bolt used in this application; Figure 6 This is a schematic diagram illustrating the through-hole in this application; Figure 7 This is a diagram showing the path of the airflow blowing out of the through hole in this application; Figure 8 This is a line graph showing the data on the gasket height and through-hole diameter in this application; Figure 9 This application includes a table showing the gasket height and through-hole diameter. Figure 10 This is a schematic diagram of the present application with a wafer placed on it; Figure 11 for Figure 10 Enlarged view of point A in the middle.

[0012] The components are as follows: 1. Chassis; 2. Top cover; 3. Cavity; 4. Protrusion; 5. Annular groove; 6. Through hole; 7. Gasket; 8. Air intake channel; 9. Auxiliary cavity; 10. Airflow channel; 11. Chamfer; 12. First sealing ring mounting groove; 13. Second sealing ring mounting groove; 14. First screw hole; 15. Second screw hole; 16. Bolt; 17. Air intake connector; 18. Third sealing ring mounting groove; 19. Protective plate; 20. Wafer. Detailed Implementation

[0013] like Figure 1-11 As shown, a Bernoulli suction cup capable of adsorbing ultrathin wafers includes a base 1, a top cover 2, and a gasket 7. The upper surface of the base 1 has a coaxial cavity 3, and an air intake device communicating with the cavity 3 is provided on the base 1. The lower surface of the top cover 2 has a coaxial protrusion 4, which covers the cavity 3. The protrusion 4 is coaxial with the cavity 3, and a predetermined gap exists between the circumferential surface of the protrusion 4 and the inner circumferential surface of the cavity 3. The upper surface of the top cover 2 has a coaxial annular groove 5. The projection of the protrusion 4 on the lower surface of the upper cover 2 is located within the projection of the protrusion 4 on the lower surface of the upper cover 2. At least four through holes 6 are arranged in a circular array around the central axis of the upper cover 2 on the circumferential wall of the protrusion 4. One end of the through hole 6 facing the central axis of the upper cover 2 is connected to the annular groove 5. The projection of the central axis of the through hole 6 on the upper surface of the upper cover 2 is at a predetermined distance from the center of the upper cover 2. Several gaskets 7 are arranged in a circular array around the annular groove 5 on the upper surface of the upper cover 2. A predetermined gap is set between any two adjacent gaskets 7.

[0014] In this embodiment, after air is injected into the cavity 3 through the air intake device, the airflow enters the gap between the protrusion 4 and the cavity 3 and is ejected into the annular groove 5 through the through hole 6. Because of the gaskets 7, when the wafer 20 is supported by all the gaskets 7, the airflow from the through hole 6 is guided by the chamfer 11 and ejected from the gap between the gaskets 7 (e.g., Figure 7 As shown, the airflow paths a, b, and c are such that the wafer 20 placed on the pad 7 is subjected to negative pressure and adsorbed. The protrusion 4 is designed to compress the airflow within the cavity 3. The preset distance between the projection of the central axis of the through hole 6 onto the upper surface of the upper cover 2 and the center of the upper cover 2 is designed to ensure that the projection of the airflow path onto the wafer 20 after exiting the through hole has sufficient length, that is, to ensure that the airflow exiting from each through hole 6 can form a sufficient negative pressure area. This design, through positive pressure, creates a fixed suction force on the upper cover 2. At the same time, when adsorbing the wafer 20, the wafer 20 is in a floating state, thus preventing the wafer 20 from being broken by suction, and solving the problem of how to adsorb an ultra-thin wafer 20. As a preferred embodiment, the height of the gasket 7 is 0.2 mm, and the diameter of the through hole 6 is 1 mm. For example... Figure 8 and Figure 9 As shown, the height of the shim 7 is 0.2 mm, which is the distance between the upper surface of the shim 7 and the upper surface of the chassis 1. In this field, an accuracy within ±0.1 mm is acceptable. Clearly, based on experimental data, a shim height of 0.2 mm is significantly better than 0.6 mm, because the accuracy of various parameters is closer to 0 when the height is 0.2 mm than when it is 0.6 mm.

[0015] In a preferred embodiment, the air intake device includes an air intake channel 8, which is coaxially disposed on the bottom wall of the concave cavity 3. An auxiliary cavity 9 is coaxially disposed on the protrusion 4, with its opening facing downwards. An airflow channel 10 is disposed on the side wall of the auxiliary cavity 9, with one end of the airflow channel 10 extending to the circumferential surface of the protrusion 4. With this configuration, the airflow entering through the air intake channel 8 enters the auxiliary cavity 9 from the bottom of the concave cavity 3, then passes through the airflow channel 10 and enters the gap formed between the inner side wall of the concave cavity 3 and the circumferential surface of the protrusion 4, finally passing through the through hole 6 to form... Figure 7 Airflows a, b, and c are introduced. This creates a negative pressure area on the upper surface of the cover 2. Because the angle between the direction of airflows a, b, and c as they flow out of the upper surface of the cover 2 and the upper surface of the cover 2 is very small, the wafer 20 placed on the gasket 7 is subjected to negative pressure, thereby attracting the wafer 20.

[0016] As a preferred embodiment, a first sealing ring mounting groove 12 is coaxially provided on the upper surface of the chassis 1 outside the cavity 3. The first sealing ring mounting groove 12 is provided so that when the upper cover 2 is installed on the chassis 1, the sealing ring can be installed in the first sealing ring mounting groove 12, thereby ensuring the airtightness of the cavity 3.

[0017] As a preferred embodiment, a second sealing ring mounting groove 13 is coaxially provided on the inner bottom wall of the cavity 3. The projection of the air intake channel 8 on the inner bottom wall of the cavity 3 lies within the annulus formed by the second sealing ring mounting groove 13, and the projection of the auxiliary cavity 9 on the inner bottom wall of the cavity 3 also lies within the annulus formed by the second sealing ring mounting groove 13. With this configuration, during assembly, by placing the sealing ring in the second sealing ring mounting groove 13, the cavity 3 and the air intake channel 8 are airtightly isolated. This allows the airflow entering from the air intake channel 8 to pass through the auxiliary cavity 9, then completely through the airflow channel 10, and finally enter the gap formed between the inner side wall of the cavity 3 and the circumferential surface of the protrusion 4, before being ejected from the through hole 6, thus forming airflows a, b, and c.

[0018] As a preferred method, such as Figure 5 As shown, a first screw hole 14 is provided through the lower surface of the chassis 1, and a second screw hole 15 is provided on the lower surface of the upper cover 2 to mate with the first screw hole 14. The second screw hole 15 is a blind hole. A bolt 16 passes through the first screw hole 14 and is threaded into the second screw hole 15. The projections of the first screw hole 14 and the second screw hole 15 on the lower surface of the cavity 3 are located between the auxiliary cavity 9 and the second sealing ring mounting groove 13. The projections of the first screw hole 14 and the second screw hole 15 on the lower surface of the cavity 3 are located between the air intake channel 8 and the second sealing ring mounting groove 13. After this arrangement, the base 1 and the upper cover 2 are locked together by the bolt 16. Furthermore, since the projections of the first screw hole 14 and the second screw hole 15 on the lower surface of the cavity 3 are located between the auxiliary cavity 9 and the second sealing ring mounting groove 13, the setting of the first screw hole 14 and the second screw hole 15 does not need to consider the sealing performance. That is to say, even if the first screw hole 14 and the second screw hole 15 are not sealed, it will not affect the sealing performance of the gap formed between the inner wall of the cavity 3 and the circumferential surface of the protrusion 4, and will not affect the magnitude of the air pressure ejected at the through hole 6, which is very ingenious.

[0019] As a preferred embodiment, an air intake connector 17 is also included. The air intake connector 17 is a connecting pipe, one end of which is inserted into the air intake channel 8, allowing airflow to be delivered through the air intake channel 8 via the connecting pipe network. To ensure that the input airflow does not leak, a protective plate 19 is provided on the connecting pipe near the end close to the chassis 1. A third sealing ring mounting groove 18 is coaxially provided on the side of the protective plate 19 near the chassis 1. The projections of the air intake channel 8 and the auxiliary cavity 9 onto the lower surface of the chassis 1 are both located within the annulus formed by the projection of the third sealing ring mounting groove 18 onto the lower surface of the chassis 1, thus preventing airflow leakage from the connecting pipe. The protective plate is locked to the lower surface of the chassis 1 by screws outside the annulus of the third sealing ring mounting groove 18. Of course, the screws will not penetrate the chassis 1. In addition to providing a sealing effect for the third sealing ring mounting groove 18, the protective plate 19 also protects the connection between the connecting pipe and the air intake channel 8, preventing the connecting pipe from falling off the air intake channel 8.

Claims

1. A Bernoulli suction cup capable of adsorbing ultrathin wafers, characterized in that, Includes a chassis (1), a top cover (2), and a gasket (7). The upper surface of the chassis (1) has a coaxial cavity (3). An air intake device communicating with the cavity (3) is provided on the chassis (1). The lower surface of the top cover (2) has a coaxial protrusion (4). The top cover (2) covers the cavity (3). The protrusion (4) is coaxial with the cavity (3). A pre-set gap exists between the circumferential surface of the protrusion (4) and the inner circumferential surface of the cavity (3). The upper surface of the top cover (2) has a coaxial annular groove (5). The opening of the annular groove (5) has a chamfer (11). The annular groove (5) is located at... The projection of the lower surface of the cover (2) is located within the projection of the protrusion (4) on the lower surface of the cover (2). At least four through holes (6) are arranged in a circular array around the central axis of the cover (2) on the circumferential wall of the protrusion (4). One end of the through hole (6) facing the central axis of the cover (2) is connected to the annular groove (5). The projection of the central axis of the through hole (6) on the upper surface of the cover (2) is at a predetermined distance from the center of the cover (2). Several gaskets (7) are arranged in a circular array outside the annular groove (5) on the upper surface of the cover (2). A predetermined gap is between any two adjacent gaskets (7).

2. The Bernoulli chuck for adsorbing ultrathin wafers according to claim 1, characterized in that: The height of the gasket (7) is 0.2 mm, and the diameter of the through hole (6) is 1 mm.

3. The Bernoulli chuck for adsorbing ultrathin wafers according to claim 1, characterized in that: The air intake device includes an air intake channel (8), the air intake channel (8) is coaxially provided on the bottom wall of the cavity (3), the auxiliary cavity (9) is coaxially provided on the protrusion (4), the opening of the auxiliary cavity (9) is downward, the airflow channel (10) is provided on the side wall of the auxiliary cavity (9), and the end of the airflow channel (10) facing away from the auxiliary cavity (9) extends to the circumferential surface of the protrusion (4).

4. A Bernoulli chuck for adsorbing ultrathin wafers according to claim 3, characterized in that: The upper surface of the chassis (1) is provided with a first sealing ring mounting groove (12) coaxially outside the cavity (3).

5. A Bernoulli chuck for adsorbing ultrathin wafers according to claim 4, characterized in that: The inner bottom wall of the cavity (3) is coaxially provided with a second sealing ring mounting groove (13). The projection of the air intake channel (8) on the inner bottom wall of the cavity (3) is within the annulus formed by the second sealing ring mounting groove (13). The projection of the auxiliary cavity (9) on the inner bottom wall of the cavity (3) is within the annulus formed by the second sealing ring mounting groove (13).

6. A Bernoulli chuck for adsorbing ultrathin wafers according to claim 5, characterized in that: A first screw hole (14) is provided through the lower surface of the chassis (1), and a second screw hole (15) is provided on the lower surface of the upper cover (2) to cooperate with the first screw hole (14). The second screw hole (15) is a blind hole. After the bolt (16) passes through the first screw hole (14), it is threadedly connected to the second screw hole (15). The projections of the first screw hole (14) and the second screw hole (15) on the lower surface of the cavity (3) are located between the auxiliary cavity (9) and the second sealing ring mounting groove (13). The projections of the first screw hole (14) and the second screw hole (15) on the lower surface of the cavity (3) are located between the air intake channel (8) and the second sealing ring mounting groove (13).

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