Surface waxing device and method for polishing large-size silicon wafer

Abstract

A surface waxing device for large-size silicon wafer polishing comprises a storage tank used for storing wax liquid, a conveying pump used for conveying the wax liquid outwards is arranged on the storage tank, the output end of the conveying pump is communicated with a heating pipe, the heating pipe extends downwards and is connected with a connector, a confluence cavity is formed in the connector, and the confluence cavity is communicated with the storage tank. The upper end of the confluence cavity is communicated with the heating pipe, the lower end of the confluence cavity is communicated with an output pipe used for conveying wax liquid, the side portion of the confluence cavity is communicated with a gas source through a gas supply pipe, the gas source conveys gas into the confluence cavity through the gas supply pipe, and the gas can cut off the wax liquid in the confluence cavity so that a plurality of wax liquid sections and a plurality of gas sections can be formed in the output pipe. And the plurality of wax liquid sections and the plurality of gas sections are distributed in a staggered manner. When the surface of the silicon wafer is waxed, the amount of the wax liquid conveyed each time is fixed, the wax liquid exists in the output pipe in the form of the wax liquid section, and after the wax liquid of one wax liquid section is discharged, the wax liquid temporarily stored in the output pipe can be prevented from dripping without reversely sucking the wax liquid.

Description

Technical Field

[0001] The present invention relates to the technical field of silicon wafer production, and more specifically, to a surface waxing device and method for polishing large-sized silicon wafers. Background Art

[0002] Silicon wafers are one of the most important raw materials for semiconductor products. During the production process of silicon wafers, the surface needs to be polished to fully eliminate surface defects and thus ensure the quality of subsequent deep-processed products. During the polishing process of silicon wafers, many processes are required. Between different processes, the silicon wafers are usually pasted on a carrier plate made of ceramic material, and then the carrier plate and the silicon wafers are transferred synchronously. In the prior art, the silicon wafers are mainly pasted on the carrier plate using a wax material, which facilitates the removal of the silicon wafers from the carrier plate after polishing. When pasting the silicon wafers on the carrier plate, it is first necessary to uniformly coat the surface of the silicon wafers with wax liquid. The commonly used method is to use the cooperation of a delivery pump and a delivery pipe to deliver the wax liquid. When the wax liquid flows out from the end of the delivery pipe, it can drip down onto the silicon wafers, and then the silicon wafers are rotated to make the wax liquid evenly distributed on the surface of the silicon wafers. However, after the wax liquid drips, there will be a certain amount of wax liquid remaining at the end of the delivery pipe. This part of the wax liquid is very likely to continue to drip under the action of gravity. If the silicon wafers have been transferred away at this time, this part of the wax liquid is very likely to contaminate the equipment and cause waste of the wax liquid. To avoid this problem, in the prior art, after squeezing out a part of the wax liquid from the delivery pipe, the delivery pump will perform a reverse suction action to suck the wax liquid at the end of the delivery pipe backward to prevent this part of the wax liquid from continuing to drip. However, this method still has certain deficiencies. The main problem is that it is difficult to control the output volume of the wax liquid when supplying the wax liquid again after the suction action. For large-sized silicon wafers such as eight-inch and twelve-inch wafers, when the output volume of the wax liquid is not well controlled, it is easy to cause insufficient or excessive wax liquid on the surface of the silicon wafers, resulting in the silicon wafers not being well pasted on the carrier plate. Summary of the Invention

[0003] To solve the deficiencies in the prior art, the present invention provides a surface waxing device and method for polishing large-sized silicon wafers. When waxing the surface of the silicon wafers, the amount of wax liquid delivered each time is fixed and exists in the form of a wax liquid segment in the output pipe. After a wax liquid segment is discharged, it is not necessary to perform a reverse suction of the wax liquid to avoid the dripping of the wax liquid temporarily stored in the output pipe, which can avoid waste of the wax liquid and contamination of the equipment.

[0004] To achieve the above object, the specific solution adopted by the present invention is as follows: A surface waxing device for polishing large-sized silicon wafers, comprising a storage tank for storing wax liquid, a transfer pump for delivering the wax liquid outward is arranged on the storage tank, and the output end of the transfer pump is communicated with a heating pipe. The heating pipe extends downward and is connected with an adapter. A confluence chamber is formed inside the adapter. The upper end of the confluence chamber is communicated with the heating pipe, and the lower end of the confluence chamber is communicated with an output pipe for delivering the wax liquid. The side part of the confluence chamber is communicated with a gas source through a gas supply pipe. The gas source delivers gas into the confluence chamber through the gas supply pipe. The gas can cut off the wax liquid in the confluence chamber to form multiple wax liquid segments and multiple gas segments in the output pipe, and the multiple wax liquid segments and multiple gas segments are distributed alternately.

[0005] As a further optimization of the above surface waxing device for polishing large-sized silicon wafers: The device includes a base, and a plurality of support columns are vertically and fixedly arranged on the base. The upper ends of all the support columns are fixedly connected together with a top plate. The storage tank is fixedly arranged on the top plate. An outlet is formed at the bottom of the storage tank, and the outlet is communicated with the transfer pump, and the transfer pump extends downward.

[0006] As a further optimization of the above surface waxing device for polishing large-sized silicon wafers: At least one of the support columns is fixedly connected with a connecting rod, and a guide wheel is rotatably connected to the connecting rod. The output pipe can bypass the guide wheel.

[0007] As a further optimization of the above surface waxing device for polishing large-sized silicon wafers: A box body is penetrated through the base, and the box body is located below the end of the output pipe. The top of the base is open to form a dripping opening for the wax liquid to pass through, and the bottom of the base is open to form an access passage for the silicon wafer to enter and exit the box body.

[0008] As a further optimization of the above surface waxing device for polishing large-sized silicon wafers: A conical box communicated with the dripping opening is fixedly connected to the top of the box body. The small end of the conical box is upward and open for the wax liquid to drip into the dripping opening. After the silicon wafer enters the box body, it can move into the interior of the conical box.

[0009] As a further optimization of the above surface waxing device for polishing large-sized silicon wafers: At least two positioning rods are fixedly connected to the small end of the conical box, and all the positioning rods are fixedly connected together with a positioning sleeve. The end of the output pipe passes through the positioning sleeve.

[0010] As a further optimization of the above surface waxing device for polishing large-sized silicon wafers: A receiving ring is fixedly arranged on the inner wall of the lower part of the box body, a receiving groove is formed on the receiving ring, and a recovery pipe is communicated with the lowest part of the receiving groove.

[0011] As a further optimization of the above surface waxing device for polishing large-sized silicon wafers: A guiding ring is fixedly arranged in the confluence chamber. The upper part of the guiding ring forms a guiding hole for gathering wax liquid, the inner hole of the guiding ring forms a through hole communicating with the guiding hole, and the lower part of the guiding ring is provided with a windward inclined surface. The gas input into the confluence chamber through the air supply pipe by the air source can impact on the windward inclined surface to cut off the wax liquid.

[0012] A surface waxing method for polishing large-sized silicon wafers, based on the above surface waxing device for polishing large-sized silicon wafers, the method includes the following steps:

[0013] Use the transfer pump to transfer the wax liquid in the storage tank to the confluence chamber;

[0014] Use the air source to periodically transport gas into the confluence chamber through the air supply pipe. The gas can cut off the wax liquid in the confluence chamber and can enter the output pipe, so that a plurality of wax liquid segments and a plurality of gas segments are formed in the output pipe in an alternating distribution.

[0015] As a further optimization of the above surface waxing method for polishing large-sized silicon wafers: The following steps are also included:

[0016] Move the silicon wafer below the end of the output pipe so that the wax liquid of one wax liquid segment drips down onto the silicon wafer.

[0017] Beneficial effects: When using the present invention to wax the surface of a silicon wafer, first use the transfer pump to transfer the wax liquid in the storage tank to the confluence chamber. During the transfer process, the heating pipe can generate heat and heat the wax liquid to ensure that the wax liquid can flow smoothly; then, the wax liquid can enter the output pipe through the confluence chamber. At the same time, the air source periodically transports gas into the confluence chamber through the air supply pipe. The gas can cut off the wax liquid and can also enter the output pipe, thereby forming a plurality of wax liquid segments and a plurality of gas segments in the output pipe in an alternating distribution. Among them, the wax liquid segments are the wax liquid obtained from the storage tank, and the gas segments are the gas transported by the air source. After the silicon wafer is transferred below the end of the output pipe, through the cooperation of the transfer pump and the air source, all the wax liquid of one wax liquid segment can be discharged downward. After these wax liquids fall on the silicon wafer, the wax liquid can be evenly covered on the surface of the silicon wafer by rotating the silicon wafer. After all the wax liquid of one wax liquid segment is discharged, the gas segment seals the subsequent wax liquid segment in the output pipe, thereby avoiding the natural fall of the temporarily stored wax liquid in the output pipe under the action of gravity, which can not only avoid wasting wax liquid but also avoid polluting the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 is the overall structural schematic diagram of the device of the present invention; Figure 2 is the internal structural schematic diagram of the adapter; Figure 3 It is a schematic diagram of the distribution mode of the wax liquid section and the gas section in the output pipe; Figure 4 It is a schematic diagram of the structure of the box body.

[0019] Description of the drawings: 1 - base, 2 - support column, 3 - connecting rod, 4 - gas source, 5 - supply pipe, 6 - top plate, 7 - storage tank, 8 - transfer pump, 9 - heating pipe, 10 - adapter, 11 - guide wheel, 12 - output pipe, 13 - box body, 14 - conical box, 15 - receiving ring, 16 - receiving groove, 17 - inlet and outlet channel, 18 - silicon wafer, 19 - recovery pipe, 20 - positioning rod, 21 - positioning sleeve, 22 - confluence chamber, 23 - guide hole, 24 - through hole, 25 - windward inclined plane, 26 - gas section, 27 - wax liquid section. Detailed implementation manners

[0020] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0021] As Figures 1 to 4 shown, a surface waxing device for polishing large - size silicon wafers includes a storage tank 7 for storing wax liquid. A transfer pump 8 for outwardly transporting wax liquid is provided on the storage tank 7. The output end of the transfer pump 8 is communicated with a heating pipe 9. The heating pipe 9 extends downward and is connected with an adapter 10. A confluence chamber 22 is provided inside the adapter 10. The upper end of the confluence chamber 22 is communicated with the heating pipe 9. The lower end of the confluence chamber 22 is communicated with an output pipe 12 for transporting wax liquid. The side part of the confluence chamber 22 is communicated with a gas source 4 through a supply pipe 5. The gas source 4 transports gas into the confluence chamber 22 through the supply pipe 5. The gas can cut off the wax liquid in the confluence chamber 22 to form a plurality of wax liquid sections 27 and a plurality of gas sections 26 in the output pipe 12, and the plurality of wax liquid sections 27 and the plurality of gas sections 26 are alternately distributed.

[0022] When waxing the surface of the silicon wafer 18 using the present invention, first, a wax pump 8 is used to transport the wax liquid in the storage tank 7 to the confluence chamber 22. During the transportation process, the heating pipe 9 can generate heat and heat the wax liquid to ensure the smooth flow of the wax liquid. Then, the wax liquid can enter the output pipe 12 through the confluence chamber 22. At the same time, the gas source 4 periodically transports gas into the confluence chamber 22 through the gas supply pipe 5. The gas can cut off the wax liquid and also enter the output pipe 12, thereby forming multiple staggered wax liquid segments 27 and multiple gas segments 26 in the output pipe 12. The wax liquid segment 27 is the wax liquid obtained from the storage tank 7, and the gas segment 26 is the gas transported by the gas source 4. After the silicon wafer 18 is transferred below the end of the output pipe 12, through the cooperation of the wax pump 8 and the gas source 4, all the wax liquid in a wax liquid segment 27 can be discharged downward. After these wax liquids fall on the silicon wafer 18, the silicon wafer 18 can be rotated to evenly cover the surface of the silicon wafer 18 with the wax liquid. After all the wax liquid in a wax liquid segment 27 is discharged, the gas segment 26 seals the subsequent wax liquid segment 27 in the output pipe 12, thereby preventing the wax liquid temporarily stored in the output pipe 12 from falling naturally under the action of gravity, which can not only avoid wasting wax liquid but also avoid polluting the equipment.

[0023] When waxing the surface of the silicon wafer 18 using the present invention, the amount of wax liquid transported each time is fixed and exists in the form of wax liquid segments 27 in the output pipe 12. After the wax liquid in a wax liquid segment 27 is discharged, it is not necessary to reverse suction the wax liquid to prevent the wax liquid temporarily stored in the output pipe 12 from dripping, which can avoid wasting wax liquid and polluting the equipment.

[0024] Furthermore, the device includes a base 1. A plurality of support columns 2 are vertically and fixedly arranged on the base 1. The upper ends of all the support columns 2 are fixedly connected to a top plate 6 together. The storage tank 7 is fixedly arranged on the top plate 6. An outlet is opened at the bottom of the storage tank 7, and the outlet is communicated with the wax pump 8, and the wax pump 8 extends downward. It should be noted that the structures and working principles of the storage tank 7, the output pump 8, and the heating pipe 9 are all mature prior arts in the field and will not be elaborated here.

[0025] To ensure the structural stability of the output pipe 12 and prevent the wax liquid from being cut off due to excessive local bending of the output pipe 12, at least one support column 2 is fixedly connected with a connecting rod 3. The connecting rod 3 is rotatably connected with a guide wheel 11. The output pipe 12 can bypass the guide wheel 11, thereby using the guide wheel 11 to control the direction of the output pipe 12 and prevent the output pipe 12 from being overly bent.

[0026] To facilitate the silicon wafer 18 to receive the wax liquid, a box body 13 is penetrated through the base 1. The box body 13 is located below the end of the output pipe 12. The top of the base 1 is open to form a dripping port for the wax liquid to pass through, and the bottom of the base 1 is open to form an access channel 17 for the silicon wafer 18 to enter and exit the box body 13. After the silicon wafer 18 enters the box body 13, the wax liquid in the wax liquid section 27 can drip downward under the action of the transfer pump 8 and the gas source 4, pass through the dripping port and then fall on the silicon wafer 18. Then, the silicon wafer 18 can be driven to rotate to make the wax liquid evenly distributed on the silicon wafer 18. During the process, a part of the wax liquid will be thrown off from the silicon wafer 18, and this part of the wax liquid can impact on the inner wall of the box body 13, thus avoiding splashing everywhere and polluting the equipment.

[0027] Further, a conical box 14 communicated with the dripping port is fixedly connected to the top of the box body 13. The small end of the conical box 14 is upward and open for the wax liquid to drip into the dripping port. After the silicon wafer 18 enters the box body 13, it can move into the interior of the conical box 14. By providing the conical box 14, it is possible to prevent some wax liquid from flying upward through the dripping port during the rotation of the silicon wafer 18, and further avoid polluting other surrounding equipment.

[0028] To ensure that the wax liquid in the output pipe 12 can smoothly pass through the dripping port and fall on the silicon wafer 18, at least two positioning rods 20 are fixedly connected to the small end of the conical box 14. All the positioning rods 20 are fixedly connected to a positioning sleeve 21 together, and the end of the output pipe 12 passes through the positioning sleeve 21. Through the cooperation of the positioning rods 20 and the positioning sleeve 21, the position of the end of the output pipe 12 can be stabilized, ensuring that it is directly above the dripping port, and further ensuring that the wax liquid in the wax liquid section 27 can smoothly pass through the dripping port and fall on the silicon wafer 18 during the downward dripping process.

[0029] To facilitate the collection of the wax liquid thrown out during the rotation of the silicon wafer 18, a receiving ring 15 is fixedly arranged on the inner wall of the lower part of the box body 13. A receiving groove 16 is formed on the receiving ring 15, and the lowest part of the receiving groove 16 is communicated with a recovery pipe 19. When the wax liquid is thrown off from the silicon wafer 18, it can impact on the inner wall of the box body 13, then slide downward along the inner wall of the box body 13 into the receiving groove 16, finally converge at the lowest part of the receiving groove 16, and be recovered through the recovery pipe 19, thus realizing the recovery of the wax liquid. While avoiding polluting the equipment, this part of the wax liquid can also be reused.

[0030] In order to fully ensure that the gas transported from the gas source 4 to the confluence chamber 22 through the supply pipe 5 can cut off the wax liquid, a guide ring is fixedly arranged in the confluence chamber 22. The upper part of the guide ring forms a guide hole 23 for gathering the wax liquid, the inner hole of the guide ring forms a through hole 24 communicating with the guide hole 23, and the lower part of the guide ring is provided with a windward inclined surface 25. The gas input from the gas source 4 to the confluence chamber 22 through the supply pipe 5 can impact on the windward inclined surface 25 to cut off the wax liquid. When the wax liquid enters the confluence chamber 22 through the heating pipe 9, it first enters the guide hole 23. The guide hole 23 has a structure that is larger at the top and smaller at the bottom, so as to gather the wax liquid into the through hole 24. Then, after the wax liquid passes through the through hole 24, it reaches the side of the windward inclined surface 25. At this time, the gas blows towards the windward inclined surface 25. Under the action of the windward inclined surface 25, the gas can flow downward, so as to quickly occupy the lower space of the confluence chamber 22, and further cut off the wax liquid.

[0031] The present invention also provides a surface waxing method for polishing large-size silicon wafers, based on the above-mentioned surface waxing device for polishing large-size silicon wafers. The method includes S1 to S3.

[0032] S1. Use the transfer pump 8 to transport the wax liquid in the storage tank 7 to the confluence chamber 22.

[0033] S2. Use the gas source 4 to periodically transport gas to the confluence chamber 22 through the supply pipe 5. The gas can cut off the wax liquid in the confluence chamber 22 and can enter the output pipe 12, so that a plurality of wax liquid segments 27 and a plurality of gas segments 26 are formed in the output pipe 12 in an alternating distribution.

[0034] S3. Move the silicon wafer 18 to the lower part of the end of the output pipe 12, so that the wax liquid of a wax liquid segment 27 drips down onto the silicon wafer 18.

[0035] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art. The general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A surface wax coating device for polishing large-size silicon wafers, characterized in that: The invention comprises a storage tank (7) for storing wax liquid, wherein a delivery pump (8) for delivering the wax liquid to the outside is arranged on the storage tank (7), and the output end of the delivery pump (8) is connected to a heating pipe (9), the heating pipe (9) extends downward and is connected to a connector (10), a confluence chamber (22) is provided inside the connector (10), the upper end of the confluence chamber (22) is connected to the heating pipe (9), the lower end of the confluence chamber (22) is connected to an output pipe (12) for delivering the wax liquid, the side of the confluence chamber (22) is connected to an air source (4) through an air supply pipe (5), the air source (4) delivers gas to the confluence chamber (22) through the air supply pipe (5), and the gas can cut off the wax liquid in the confluence chamber (22) so that a plurality of wax liquid segments (27) and a plurality of gas segments (26) are formed in the output pipe (12), and the plurality of wax liquid segments (27) and the plurality of gas segments (26) are staggeredly distributed.

2. A surface wax coating device for polishing large-size silicon wafers as claimed in claim 1, characterized in that: The device comprises a base (1), a plurality of support columns (2) are vertically fixedly arranged on the base (1), the upper ends of all the support columns (2) are commonly fixedly connected to a top plate (6), the storage tank (7) is fixedly arranged on the top plate (6), an outlet is opened at the bottom of the storage tank (7), the outlet is connected to the delivery pump (8), and the delivery pump (8) extends downward.

3. A surface wax coating device for polishing large-size silicon wafers as claimed in claim 2, characterized in that: At least one of the support columns (2) is fixedly connected to a connecting rod (3), the connecting rod (3) is rotatably connected to a guide wheel (11), and the output pipe (12) can bypass the guide wheel (11).

4. A surface wax coating device for polishing large-size silicon wafers as claimed in claim 2, characterized in that: A box body (13) is provided on the base (1), and the box body (13) is located below the end of the output tube (12). The top of the base (1) is open to form a dripping port for wax liquid to pass through, and the bottom of the base (1) is open to form an inlet and outlet channel (17) for silicon wafers (18) to enter and exit the box body (13).

5. A surface wax coating device for polishing large-size silicon wafers as claimed in claim 4, characterized in that: A conical box (14) connected to the dripping port is fixedly connected to the top of the box body (13); the small end of the conical box (14) is arranged upward and is open to allow the wax liquid to drip into the dripping port; and the silicon wafer (18) can move to the interior of the conical box (14) after entering the box body (13).

6. A surface wax coating device for polishing large-size silicon wafers as claimed in claim 5, characterized in that: At least two positioning rods (20) are fixedly connected to the small end of the conical box (14), all the positioning rods (20) are fixedly connected to a positioning sleeve (21), and the end of the output pipe (12) passes through the positioning sleeve (21).

7. The surface wax coating device for polishing large-size silicon wafers as claimed in claim 4, characterized in that: A receiving ring (15) is fixedly arranged on the inner wall of the lower part of the box body (13), a receiving groove (16) is opened on the receiving ring (15), and a recovery pipe (19) is connected to the lowest point of the receiving groove (16).

8. The surface wax coating device for polishing large-size silicon wafers as claimed in claim 1, characterized in that: A guide ring is fixedly arranged in the confluence chamber (22), a guide hole (23) for gathering wax liquid is formed on the upper part of the guide ring, a through hole (24) connected to the guide hole (23) is formed on the inner hole of the guide ring, and a windward inclined surface (25) is arranged on the lower part of the guide ring. The gas input into the confluence chamber (22) by the gas source (4) through the gas supply pipe (5) can impact on the windward inclined surface (25) to cut off the wax liquid.

9. A surface wax coating method for polishing large-size silicon wafers, characterized in that: Based on a surface wax coating device for polishing a large-size silicon wafer as described in any one of claims 1 to 8, the method comprises the following steps: Using the delivery pump (8) to deliver the wax liquid in the storage tank (7) to the confluence chamber (22); The gas source (4) is used to periodically deliver gas to the confluence chamber (22) through the gas supply pipe (5); the gas can cut off the wax liquid in the confluence chamber (22) and can enter the output pipe (12), so that a plurality of wax liquid sections (27) and a plurality of gas sections (26) that are staggered and distributed are formed in the output pipe (12).

10. A surface wax coating method for polishing a large-size silicon wafer as claimed in claim 9, characterized in that: The following steps are also included: The silicon wafer (18) is moved to below the end of the output pipe (12), so that the wax liquid of one of the wax liquid sections (27) drips downward onto the silicon wafer (18).

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