A buffer for photoresist supply lines

Abstract

This invention belongs to the field of semiconductor equipment technology, specifically a buffer for a photoresist supply pipeline. It includes a cylindrical body, an upper cover, and a lower cover. The upper cover has a waste discharge channel for connecting to an external waste discharge pipeline. The lower cover has an inlet and an outlet, with the inlet connected to an external inlet pipeline and the outlet connected to an external outlet pipeline. The lower cover has an anti-backflow protrusion, an inverted conical liquid passage space, and a liquid outflow hole. A baffle ball is installed in the inverted conical liquid passage space. This invention effectively prevents photoresist from flowing back into the inlet pipeline when excessive photoresist is added, automatically achieving unidirectional flow control of the photoresist and avoiding interference with liquid level detection. It also reliably discharges high-pressure gas or excess photoresist from the inner cavity of the cylindrical body, while maintaining stable gas pressure within the inner cavity, thereby ensuring stable operation of the photoresist pump.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor equipment technology, specifically a buffer for a photoresist supply pipeline. Background Technology

[0002] Currently, buffers are typically required in the photoresist supply lines of semiconductor equipment. These buffers work in conjunction with the photoresist bottles and pumps to supply photoresist to various process stations and act as a buffer during the photoresist supply process. Current buffers typically include a buffer cylinder and a level sensor mounted on the buffer cylinder.

[0003] The buffer cylinder of the prior art buffer 001, such as Figure 4 As shown, a waste outlet for connecting to the waste discharge pipe is typically located at the lower end, an inlet for connecting to the liquid inlet pipe is located in the middle of the upper end, and an outlet for connecting to the liquid outlet pipe is located on one side of the upper end. This structure is prone to overfilling with photoresist when supplying it to the buffer cylinder (at which point the liquid inlet pipe is open, the liquid outlet pipe remains closed, and the waste discharge pipe is open to expel gas from the buffer cylinder). This can cause the photoresist to flow back into the liquid inlet pipe, potentially affecting subsequent normal use. Summary of the Invention

[0004] To address the above problems, the present invention aims to provide a buffer for a photoresist supply pipeline.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A buffer for a photoresist supply pipeline includes a cylindrical body, an upper cover, and a lower cover. The upper and lower ends of the cylindrical body are open. The upper cover is used to close the upper opening of the cylindrical body, and the lower cover is used to close the lower opening of the cylindrical body.

[0007] The upper cover is provided with a waste discharge channel for connecting to an external waste discharge pipeline;

[0008] The lower cover has an inlet and an outlet. The inlet is connected to an external inlet pipe, and the outlet is connected to an external outlet pipe. An anti-backflow protrusion is provided on the inner side of the lower cover within the main body of the cylinder. An inverted conical liquid passage space is formed inside the anti-backflow protrusion. The inner diameter of the upper opening of the inverted conical liquid passage space is larger than the inner diameter of the lower opening. The lower opening of the inverted conical liquid passage space is connected to the inlet. The anti-backflow protrusion has several liquid outflow holes on its top surface. Each liquid outflow hole is located above the upper opening of the inverted conical liquid passage space and is connected to the inverted conical liquid passage space. A baffle ball is provided in the inverted conical liquid passage space. The diameter of the baffle ball is larger than the inner diameter of the lower end of the inverted conical liquid passage space and also larger than the diameter of each liquid outflow hole. The height of the liquid outlet is lower than the height of each liquid outflow hole.

[0009] The lower cover has a guide slope that gradually slopes downwards from away from the liquid outlet to near the liquid outlet on the inner side of the cylindrical body and at the outer periphery of the liquid outlet.

[0010] The inlet is connected to an external inlet pipe via a thread, and the outlet is connected to an external outlet pipe via a thread.

[0011] The upper cover is provided with a spring piston mounting hole, which has openings at both the upper and lower ends. The upper opening of the spring piston mounting hole is located on the top surface of the upper cover located on the outer side of the cylindrical body, and the lower opening of the spring piston mounting hole is located on the inner side of the upper cover located in the cylindrical body.

[0012] The upper cover is also provided with an atmospheric communication channel A and an atmospheric communication channel B. The atmospheric communication channel A has two openings. One of the openings of the atmospheric communication channel A is located on the inner side of the upper cover within the main body of the cylinder. The other opening of the atmospheric communication channel A is connected to the spring piston mounting channel. The atmospheric communication channel B has two openings. One of the openings of the atmospheric communication channel B is directly connected to the atmosphere. The other opening of the atmospheric communication channel B is connected to the spring piston mounting channel.

[0013] One opening of the waste discharge channel is used to connect to an external waste discharge pipeline, and the other opening of the waste discharge channel is connected to the spring piston mounting channel.

[0014] The spring piston mounting hole is equipped with a spring piston assembly. In the initial state, the spring piston assembly connects the inner cavity of the cylinder body, atmospheric communication channel A, and atmospheric communication channel B, and blocks the other opening of the waste discharge channel so that the waste discharge channel is not connected to the inner cavity of the cylinder body. When the pressure in the inner cavity of the cylinder body increases abnormally, the spring piston assembly connects the other opening of the waste discharge channel to the inner cavity of the cylinder body, and disconnects atmospheric communication channels A and B.

[0015] The spring piston assembly includes a mounting cover, a spring, and a piston component. The mounting cover is installed at the upper opening of the spring piston mounting channel, and the piston component is filled in the spring piston mounting channel. The bottom portion of the mounting cover located in the spring piston mounting channel is connected to the top end of the piston component by the spring.

[0016] An annular connecting groove is formed on the outer circumferential surface of the piston component; in the initial state, the annular connecting groove is directly connected to the atmospheric connecting channel A and the atmospheric connecting channel B respectively; when the pressure in the inner cavity of the cylinder body increases abnormally, the annular connecting groove is offset from the atmospheric connecting channel A and the atmospheric connecting channel B, and the other opening of the atmospheric connecting channel A and the other opening of the atmospheric connecting channel B are blocked by the outer circumferential surface of the piston component respectively.

[0017] The mounting cover is threaded onto the upper opening of the spring piston mounting hole.

[0018] One of the openings of the waste discharge channel is located on the top surface of the upper cover on the outside of the main body of the cylinder, and is connected to a waste discharge pipe joint by a thread. The waste discharge pipe joint is connected to an external waste discharge pipeline.

[0019] A liquid level detection tube communicating with the inner cavity of the main body of the cylinder is provided on the outer side of the main body of the cylinder, and a liquid level detection sensor is installed on the liquid level detection tube.

[0020] The axial centerline of the liquid level detection tube is parallel to the axial centerline of the main body of the cylinder.

[0021] The main body of the cylinder is integrally formed with the main body of the cylinder.

[0022] The advantages and positive effects of this invention are as follows:

[0023] 1. This invention can effectively prevent photoresist from flowing back into the liquid inlet pipe when excessive photoresist is filled, and automatically realize unidirectional flow control of photoresist to avoid interference with liquid level detection.

[0024] 2. The present invention can also reliably discharge high-pressure gas or excess photoresist from the inner cavity of the main body of the cylinder when excessive photoresist is filled, while maintaining stable gas pressure in the inner cavity of the main body of the cylinder, thereby ensuring stable operation of the photoresist pump. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the external structure of the present invention;

[0026] Figure 2 This is a schematic cross-sectional view of the present invention in its initial state;

[0027] Figure 3 This is a schematic cross-sectional view of the present invention when the pressure inside the main body of the cylinder increases abnormally.

[0028] Figure 4 This is a schematic diagram of the setup structure of a buffer in the prior art.

[0029] In the diagram: 1 represents the main body of the cylinder, and 101 represents the liquid level detection tube;

[0030] 2 is the top cover, 201 is the waste discharge channel, 202 is the spring piston mounting channel, 203 is the atmospheric communication channel A, and 204 is the atmospheric communication channel B.

[0031] 3 is the bottom cover, 301 is the liquid inlet, 302 is the liquid outlet, 303 is the anti-backflow protrusion, 304 is the inverted cone-shaped liquid passage space, and 305 is the liquid outflow hole;

[0032] 4 is the ball stop, 5 is the mounting cover, 6 is the spring, 7 is the piston, 701 is the annular connecting groove, 8 is the waste discharge pipe connector, and 9 is the liquid level detection sensor.

[0033] 001 is the buffer of the prior art, 002 is the liquid inlet pipe, 003 is the liquid outlet pipe, and 004 is the waste discharge pipe. Detailed Implementation

[0034] The following is in conjunction with the appendix Figure 1-3 The present invention will be described in further detail below.

[0035] A buffer for a photoresist supply line, such as Figure 1-3 As shown, this embodiment includes a cylindrical body 1, an upper cover 2, and a lower cover 3. Both the upper and lower ends of the cylindrical body 1 are open. The upper cover 2 is used to close the upper opening of the cylindrical body 1, and the lower cover 3 is used to close the lower opening of the cylindrical body 1. In this embodiment, the connection between the upper cover 2 and the lower cover 3 and the cylindrical body 1 adopts existing technology, such as a threaded connection.

[0036] The upper cover 2 is provided with a waste discharge channel 201 for connecting to the external waste discharge pipe 004, which is used to discharge excess photoresist when too much photoresist is filled into the inner cavity of the main body 1.

[0037] The lower cover 3 is provided with an inlet 301 and an outlet 302. The inlet 301 is connected to an external inlet pipe 002, and the outlet 302 is connected to an external outlet pipe 003. An anti-backflow protrusion 303 protrudes from the inner side of the lower cover 3 within the main body 1. An inverted conical liquid passage space 304 is formed inside the anti-backflow protrusion 303. The inner diameter of the upper opening of the inverted conical liquid passage space 304 is larger than the inner diameter of the lower opening. The lower opening of the inverted conical liquid passage space 304 is connected to the inlet... The outlet 301 is directly connected, and several liquid outflow holes 305 are provided on the top surface of the anti-backflow protrusion 303. Each liquid outflow hole 305 is located above the upper opening of the inverted conical liquid passage space 304 and is connected to the inverted conical liquid passage space 304. A baffle ball 4 is provided in the inverted conical liquid passage space 304. The diameter of the baffle ball 4 is larger than the inner diameter of the lower opening of the inverted conical liquid passage space 304 and also larger than the diameter of each liquid outflow hole 305. The height of the outlet 302 is lower than the height of each liquid outflow hole 305.

[0038] During normal use, the photoresist is drawn from the dispensing pump via the outlet pipe 003. The photoresist in the bottle first enters the inner cavity of the main body 1 through the inlet pipe 002, and then flows out through the outlet pipe 003, thus providing a buffer during photoresist supply. Normally, the photoresist enters through the lower opening of the inverted conical liquid passage space 304 via the inlet pipe 002, pushing up the baffle ball 4. Then, the photoresist flows upward through the upper opening of the inverted conical liquid passage space 304 and the various liquid outlet holes 305 into the inner cavity of the main body 1. However, if excessive photoresist is added, the weight of the photoresist itself and the downward pressure generated by the obstructed upward flow will press the baffle ball 4 tightly, blocking the lower opening of the inverted conical liquid passage space 304, effectively preventing the photoresist from flowing back into the inlet pipe 002. The anti-backflow protrusion 303 effectively prevents the photoresist located on the underside of the top surface of the anti-backflow protrusion 303 from flowing back into the inverted conical liquid passage space 304. During normal use, each liquid outflow hole 305 allows the photoresist to flow fully out of the inverted conical liquid passage space 304. Furthermore, because the diameter of the baffle ball 4 is larger than the diameter of each liquid outflow hole 305, the baffle ball 4 will not be pushed out of the inverted conical liquid passage space 304 by the photoresist during normal use.

[0039] Specifically, in this embodiment, the lower cover 3 has a guide slope that gradually slopes downward from away from the liquid outlet 302 to near the liquid outlet 302 on the inner side of the cylindrical body 1, which facilitates the photoresist to flow out fully from the liquid outlet 302.

[0040] Specifically, in this embodiment, the liquid inlet 301 is connected to the external liquid inlet pipe 002 by a thread, and the liquid outlet 302 is connected to the external liquid outlet pipe 003 by a thread, making disassembly and assembly convenient.

[0041] Specifically, in this embodiment, the upper cover 2 is provided with a spring piston mounting channel 202. The spring piston mounting channel 202 has openings at both the upper and lower ends. The upper opening of the spring piston mounting channel 202 is located on the top surface of the upper cover 2 located on the outside of the cylindrical body 1, and the lower opening of the spring piston mounting channel 202 is located on the inner side surface of the upper cover 2 located in the cylindrical body 1.

[0042] The upper cover 2 is also provided with an atmospheric communication channel A 203 and an atmospheric communication channel B 204. The atmospheric communication channel A 203 has two openings. One of the openings of the atmospheric communication channel A 203 is located on the inner side of the upper cover 2 within the main body 1 of the cylinder. The other opening of the atmospheric communication channel A 203 is connected to the spring piston mounting channel 202. The atmospheric communication channel B 204 has two openings. One of the openings of the atmospheric communication channel B 204 is directly connected to the atmosphere. The other opening of the atmospheric communication channel B 204 is connected to the spring piston mounting channel 202.

[0043] One opening of the waste discharge channel 201 is used to connect to the external waste discharge pipeline 004, and the other opening of the waste discharge channel 201 is connected to the spring piston mounting channel 202.

[0044] A spring piston assembly is installed in the spring piston mounting channel 202. The spring piston assembly includes a mounting cover 5, a spring 6, and a piston 7. The mounting cover 5 is installed at the upper opening of the spring piston mounting channel 202. The piston 7 is filled into the spring piston mounting channel 202. The bottom part of the mounting cover 5 in the spring piston mounting channel 202 is connected to the top part of the piston 7 by the spring 6. An annular connecting groove 701 is formed on the outer circumferential surface of the piston 7. In this embodiment, the mounting cover 5 is threaded onto the upper opening of the spring piston mounting channel 202, which is convenient for disassembly and assembly and has good airtightness.

[0045] In its initial state, the annular connecting groove 701 is directly connected to both atmospheric connecting channels A 203 and B 204, allowing gas in the inner cavity of the main body 1 to escape through atmospheric connecting channel B 204, thus ensuring reliable input of photoresist; at this time, spring 6 is not compressed. During normal use, atmospheric connecting channels A 203 and B 204 remain connected. When excessive photoresist is filled into the inner cavity of the main body 1, causing an abnormal increase in pressure within the cavity, the piston 7 rises under the pressure of the gas or liquid within the cavity, compressing the spring 6. The annular connecting groove 701 is misaligned with atmospheric connecting channels A 203 and B 204. The other openings of atmospheric connecting channels A 203 and B 204 are blocked by the outer circumferential surface of the piston 7, thus connecting the other opening of the exhaust channel 201 to the inner cavity of the main body 1. This allows the high-pressure gas or excess photoresist to be discharged through the exhaust pipe 004. At this time, atmospheric connecting channels A 203 and B 204 are not connected. After the high-pressure gas or excess photoresist in the inner cavity of the main body 1 is discharged through the exhaust pipe 004, the piston 7 falls back under the elastic force of the spring 6, returning to its initial position. Therefore, the spring piston assembly can automatically switch the air passage according to the positive and negative pressure changes inside the cylinder body 1, simplifying the buffer control logic.

[0046] Specifically, in this embodiment, one of the openings of the waste discharge channel 201 is located on the top surface of the upper cover 2, which is located outside the main body 1, and is connected to a waste discharge pipe connector 8 by a thread. The waste discharge pipe connector 8 is connected to an external waste discharge pipe 004 for easy connection. In this embodiment, the waste discharge pipe connector 8 is a commercially available product.

[0047] Specifically, in this embodiment, a liquid level detection tube 101 communicating with the inner cavity of the main body 1 is provided on the outer side of the main body 1. The axial center line of the liquid level detection tube 101 is parallel to the axial center line of the main body 1. The main body 1 and the main body 1 are integrally formed, making manufacturing easy. A liquid level detection sensor 9 is installed on the liquid level detection tube 101, which is convenient to install. In this embodiment, two liquid level detection sensors 9 are provided, both of which are commercially available products. The installation structure of the liquid level detection sensors 9 is also existing technology. The liquid level detection sensors 9 are connected to an external controller. One of them is used to detect whether the liquid level in the liquid level detection tube 101, i.e., the main body 1, is too low, and the other is used to detect whether the liquid level in the liquid level detection tube 101, i.e., the main body 1, is too high.

[0048] Working principle:

[0049] By providing a lower cover 3 with an anti-backflow boss 303, an inverted conical liquid passage space 304, a liquid outflow hole 305, and a baffle ball 4, the backflow of photoresist can be effectively prevented from the liquid inlet pipe 002 when excessive photoresist is filled, and the unidirectional flow control of the photoresist can be automatically realized to avoid interference with the liquid level detection.

[0050] In the initial state, the spring piston assembly connects the inner cavity of the main body 1, the atmospheric communication channel A 203, and the atmospheric communication channel B 204, while blocking the other opening of the waste discharge channel 201, thus preventing the waste discharge channel 201 from connecting with the inner cavity of the main body 1. During normal use, the atmospheric communication channels A 203 and B 204 remain connected. When the pressure in the inner cavity of the main body 1 increases abnormally, the spring piston assembly connects the other opening of the waste discharge channel 201 with the inner cavity of the main body 1, and prevents the atmospheric communication channels A 203 and B 204 from connecting. This reliably discharges high-pressure gas or excess photoresist from the inner cavity of the main body 1 in the event of excessive photoresist filling, while maintaining stable gas pressure in the inner cavity of the main body 1, thereby ensuring stable operation of the photoresist pump.

Claims

1. A buffer for a photoresist supply pipeline, characterized in that: It includes a cylindrical body (1), an upper cover (2), and a lower cover (3). The upper and lower ends of the cylindrical body (1) are open. The upper cover (2) is used to close the upper opening of the cylindrical body (1), and the lower cover (3) is used to close the lower opening of the cylindrical body (1). The upper cover (2) is provided with a waste discharge channel (201) for connecting to an external waste discharge pipeline. The lower cover (3) is provided with an inlet (301) and an outlet (302). The inlet (301) is connected to an external inlet pipe, and the outlet (302) is connected to an external outlet pipe. The inner side of the lower cover (3) located in the main body (1) of the cylinder is provided with an anti-backflow protrusion (303). The anti-backflow protrusion (303) is provided with an inverted cone-shaped liquid passage space (304) inside. The inner diameter of the upper opening of the inverted cone-shaped liquid passage space (304) is larger than the inner diameter of the lower opening of the inverted cone-shaped liquid passage space (304). The lower opening of the inverted cone-shaped liquid passage space (304) is connected to the inlet ( 301) Direct connection, the top surface of the anti-backflow protrusion (303) is provided with a plurality of liquid outflow holes (305), each of the liquid outflow holes (305) is located above the upper opening of the inverted conical liquid passage space (304) and is connected to the inverted conical liquid passage space (304). The inverted conical liquid passage space (304) is provided with a baffle ball (4), the diameter of the baffle ball (4) is larger than the inner diameter of the lower end of the inverted conical liquid passage space (304) and is also larger than the diameter of each of the liquid outflow holes (305). The height of the liquid outlet (302) is lower than the height of each of the liquid outflow holes (305); The upper cover (2) is provided with a spring piston mounting channel (202). The spring piston mounting channel (202) has openings at both the upper and lower ends. The upper opening of the spring piston mounting channel (202) is located on the top surface of the upper cover (2) located on the outside of the cylindrical body (1). The lower opening of the spring piston mounting channel (202) is located on the inner side of the upper cover (2) located in the cylindrical body (1). The upper cover (2) is also provided with an atmospheric communication channel A (203) and an atmospheric communication channel B (204). The atmospheric communication channel A (203) has two openings. One of the openings of the atmospheric communication channel A (203) is located on the inner side of the upper cover (2) located in the main body of the cylinder (1). The other opening of the atmospheric communication channel A (203) is connected to the spring piston mounting channel (202). The atmospheric communication channel B (204) has two openings. One of the openings of the atmospheric communication channel B (204) is directly connected to the atmosphere. The other opening of the atmospheric communication channel B (204) is connected to the spring piston mounting channel (202). One opening of the waste discharge channel (201) is used to connect to an external waste discharge pipeline, and the other opening of the waste discharge channel (201) is connected to the spring piston mounting channel (202). The spring piston mounting hole (202) is fitted with a spring piston assembly; The spring piston assembly includes a mounting cover (5), a spring (6), and a piston (7). The mounting cover (5) is installed at the upper opening of the spring piston mounting channel (202). The piston (7) is filled in the spring piston mounting channel (202). The bottom part of the mounting cover (5) in the spring piston mounting channel (202) is connected to the top part of the piston (7) by the spring (6). An annular connecting groove (701) is provided on the outer peripheral surface of the piston (7); the annular connecting groove (701) is directly connected to the atmospheric connecting channel A (203) and the atmospheric connecting channel B (204) in the initial state; when the pressure in the inner cavity of the cylinder body (1) increases abnormally, the annular connecting groove (701) is offset from the atmospheric connecting channel A (203) and the atmospheric connecting channel B (204), and the other opening of the atmospheric connecting channel A (203) and the other opening of the atmospheric connecting channel B (204) are blocked by the outer peripheral surface of the piston (7).

2. A buffer for a photoresist supply pipeline according to claim 1, characterized in that: The lower cover (3) has a guide slope that gradually slopes downward from away from the liquid outlet (302) to near the liquid outlet (302) on the inner side of the cylindrical body (1) and at the outer periphery of the liquid outlet (302).

3. A buffer for a photoresist supply pipeline according to claim 1, characterized in that: The inlet (301) is connected to an external inlet pipe via a thread, and the outlet (302) is connected to an external outlet pipe via a thread.

4. A buffer for a photoresist supply pipeline according to claim 1, characterized in that: The mounting cover (5) is threaded onto the upper opening of the spring piston mounting hole (202).

5. A buffer for a photoresist supply pipeline according to claim 1, characterized in that: One of the openings of the waste discharge channel (201) is located on the top surface of the upper cover (2) on the outside of the main body (1) and is connected to a waste discharge pipe joint (8) by a thread. The waste discharge pipe joint (8) is connected to an external waste discharge pipeline.

6. A buffer for a photoresist supply pipeline according to claim 1, characterized in that: The outer side of the main body (1) of the cylinder is provided with a liquid level detection tube (101) that communicates with the inner cavity of the main body (1), and a liquid level detection sensor (9) is installed on the liquid level detection tube (101).

7. A buffer for a photoresist supply pipeline according to claim 6, characterized in that: The axial centerline of the liquid level detection tube (101) is parallel to the axial centerline of the main body of the cylinder (1).

8. A buffer for a photoresist supply pipeline according to claim 6, characterized in that: The main body of the cylinder (1) is made in one piece.

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