Back blowing mechanism in glue uniformizing cavity

Abstract

The invention discloses a back blowing mechanism in a glue uniformizing cavity, which relates to the field of wafer glue uniformizing and comprises a supporting plate, a substrate is fixedly mounted on the upper surface of the supporting plate, a suction cup lifting system is arranged below the substrate, a movable part is mounted at the output end of the upper surface of the suction cup lifting system, and a supporting pipe is arranged in the middle of the top end in the movable part. A flow guide plate is fixedly installed on the upper surface of the supporting pipe, a circulation groove is formed in the upper surface of the flow guide plate, a flow guide hole is formed in the middle of the top end of the flow guide plate in a penetrating mode and penetrates through the supporting pipe, a first air nozzle connector is arranged at the position, extending below the movable part, of the bottom end of the flow guide hole, and a collecting mechanism is further arranged below the base plate and used for collecting generated waste liquid. An existing back washing method is replaced by back blowing airflow, an organic solution, an additional liquid medicine pipeline and a liquid medicine valve do not need to be used, and the equipment cost and the use cost are reduced; meanwhile, waste liquid is prevented from being generated, subsequent harmless treatment is not needed, operation steps are simplified, and the overall use efficiency of the wafer glue uniformizing equipment is improved.

Description

Technical Field

[0001] This invention relates to wafer spin coating technology, specifically to a backblowing mechanism within a spin coating cavity. Background Technology

[0002] Wafer spin coating equipment plays a crucial role in the semiconductor wafer manufacturing industry. Its function is to uniformly coat liquid materials onto the substrate surface through high-speed rotation, forming a thin film with controllable thickness and high consistency. Wafer spin coating is used to form a uniform photoresist film on the surface of the substrate. This film is key to the photolithography process, ensuring pattern transfer accuracy, filling tiny defects on the wafer surface, and preventing damage to the substrate from subsequent etching, ion implantation, and other processes. At the same time, it meets the requirements of different processes for the thickness of the photoresist layer, ensuring consistent performance of mass-produced chips.

[0003] During wafer spin coating, the high-speed rotation of the wafer can lead to uneven airflow, resulting in inconsistent resist thickness. Solvent volatiles can accumulate at the edges and back side, and gaseous impurities can contaminate the back side of the wafer, affecting film quality and consistency. Therefore, it is crucial to ensure consistent resist thickness and that the back side of the wafer remains clean during spin coating. Existing technologies typically use back washing to remove contaminants from the back side of the wafer, employing chemical solvents. However, back washing requires organic solutions and necessitates additional piping and chemical valves on the equipment, leading to higher operating and equipment costs. Furthermore, it generates additional waste liquid that requires treatment, making the overall operation cumbersome, time-consuming, and labor-intensive, thus impacting the overall efficiency of the wafer spin coating equipment. Summary of the Invention

[0004] The purpose of this invention is to provide a back-blowing mechanism within a coating cavity to solve the problem of the cumbersome and inconvenient process of removing dirt from the back side of wafers in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a back-blowing mechanism for a uniform adhesive cavity, comprising a support plate, a base plate fixedly mounted on the upper surface of the support plate, a suction cup lifting system disposed below the base plate, a movable component mounted at the output end of the upper surface of the suction cup lifting system, a support tube disposed at the middle of the top end of the movable component, a guide plate fixedly mounted on the upper surface of the support tube, an aerodynamic groove formed on the upper surface of the guide plate, a guide hole passing through the support tube at the middle of the top end of the guide plate, and a first air nozzle interface disposed at the bottom end of the guide hole extending to the lower part of the movable component;

[0006] A collection mechanism is also provided below the substrate for collecting the generated waste liquid.

[0007] Furthermore, the collection mechanism includes a waste liquid collection tank, which is fixedly installed on the bottom surface of the substrate near the suction cup lifting system. A second air nozzle interface is provided on one side of the bottom end of the waste liquid collection tank, and a fixed opening is provided on one side of the upper surface of the waste liquid collection tank.

[0008] Furthermore, a connecting pipe is installed at the opening between the No. 1 and No. 2 air nozzle interfaces, and a flow rate sensor and a flow control valve are connected to the outer surface of the connecting pipe.

[0009] Furthermore, a base plate is provided on the upper surface of the substrate outside the support tube, and square holes are symmetrically opened on the upper surface of the base plate, with the fixing opening and the square holes aligned with each other.

[0010] Furthermore, a plurality of through holes are provided on the upper surface edge of the base plate, and a threaded groove is provided on the upper surface of the base plate at the position corresponding to the through holes. A plurality of fastening nuts are threadedly connected inside the base plate, extending through the through holes into the threaded groove.

[0011] Furthermore, a cover plate is provided on the outer surface of the support tube near the outside of the base plate. The cover plate is welded below the guide plate, and the cover plate and the base plate are fitted together.

[0012] Furthermore, a guide rail is fixedly installed at the top of the suction cup lifting system, and guide grooves adapted to the guide rail are opened on both sides of the movable part, with the movable part located inside the guide rail.

[0013] Furthermore, a lifting and rotating dispensing system is provided at one end of the upper surface of the substrate.

[0014] Compared with the prior art, the back-blowing mechanism inside the gel-spreading cavity provided by the present invention has the following beneficial effects:

[0015] 1. This invention replaces the existing "back washing method" with "back blowing airflow", eliminating the need for organic solutions, additional chemical pipelines and chemical valves, thus reducing equipment and operating costs; at the same time, it avoids the generation of waste liquid, eliminates the need for subsequent harmless treatment, simplifies the operation steps, and improves the overall efficiency of wafer coating equipment.

[0016] 2. This invention uses the synergy of a flow rate sensor and a flow control valve to regulate the flow rate and flow of the back-blown airflow in real time. After the airflow enters through the guide hole, it is evenly diffused to the back of the wafer through the circulation groove, forming a stable airflow field. This counteracts the airflow interference caused by the high-speed rotation of the wafer, avoids uneven adhesive layer thickness, and ensures the consistency of film quality.

[0017] 3. This invention uses back-blowing airflow to actively blow away solvent volatiles and gaseous impurities on the back side of the wafer, while preventing photoresist residue from adhering to the back side; the interlocking structure of the cover plate and the base plate avoids airflow leakage and ensures that the airflow is concentrated on the back side of the wafer, further improving the anti-contamination effect.

[0018] 4. The present invention ensures the stability of the wafer lifting trajectory by cooperating with the guide rail of the suction cup lifting system and the guide slide of the moving parts; the base plate is detachably fixed to the substrate by fastening nuts, which facilitates subsequent maintenance; the fixed opening of the waste liquid collection tank is aligned with the square hole of the base plate to ensure efficient collection of waste liquid and avoid contamination of other parts of the equipment. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments recorded in this invention. For those skilled in the art, other drawings can be obtained based on these drawings.

[0020] Figure 1 This is a schematic diagram of the overall structure provided for an embodiment of the present invention;

[0021] Figure 2 This is a schematic diagram of the suction cup lifting system provided in an embodiment of the present invention;

[0022] Figure 3 This is a schematic diagram of the guide plate structure provided in an embodiment of the present invention;

[0023] Figure 4 This is a schematic diagram of the base plate structure provided in an embodiment of the present invention;

[0024] Figure 5 This is a schematic diagram of the waste liquid collection tank structure provided in an embodiment of the present invention;

[0025] Figure 6 This is a schematic diagram of the No. 2 air nozzle interface structure provided in an embodiment of the present invention.

[0026] Explanation of reference numerals in the attached figures:

[0027] 1. Support plate; 2. Base plate; 3. Suction cup lifting system; 4. Moving parts; 5. Support tube; 6. Guide plate; 7. Circulation groove; 8. Guide hole; 9. No. 1 air nozzle interface; 10. Cover plate; 11. Base plate; 12. Waste liquid collection tank; 13. No. 2 air nozzle interface; 14. Fixed opening; 15. Lifting and rotating dispensing system. Detailed Implementation

[0028] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings.

[0029] As attached Figure 1 To be continued Figure 6 As shown:

[0030] Example 1:

[0031] This invention provides a back-blowing mechanism for a uniform adhesive cavity, including a support plate 1, a base plate 2 fixedly mounted on the upper surface of the support plate 1, a suction cup lifting system 3 disposed below the base plate 2, a movable part 4 mounted at the output end of the upper surface of the suction cup lifting system 3, a support tube 5 disposed in the middle of the top of the movable part 4, a guide plate 6 fixedly mounted on the upper surface of the support tube 5, a circulation groove 7 opened on the upper surface of the guide plate 6, a guide hole 8 passing through the support tube 5 in the middle of the top of the guide plate 6, and a first air nozzle interface 9 provided at the bottom end of the guide hole 8 extending to the lower part of the movable part 4;

[0032] The suction cup lifting system 3 has a guide rail fixedly installed at the top, and the movable part 4 has guide grooves on both sides that are adapted to the guide rail. The movable part 4 is located inside the guide rail.

[0033] A lifting and rotating dispensing system 15 is provided at one edge of the upper surface of the substrate 2;

[0034] A collection mechanism is also provided below the substrate 2 for collecting the generated waste liquid.

[0035] Working principle: First, the operator fixes the support plate 1 to the steel platform of the wafer spin coating equipment with expansion bolts, and uses a laser level to calibrate the levelness of the support plate 1 (error ≤ 0.1mm / m) to ensure that the substrate 2 is not tilted after installation; then, the suction cup lifting system 3 (electric lifting platform) is fixed to the preset position below the substrate 2 with bolts, and the fit clearance between the guide rail and the guide slide of the movable part 4 is adjusted (controlled within 0.1-0.2mm). The lifting function of the movable part 4 is tested by powering on; the lifting system is started, and the movable part 4 is controlled to rise along the guide rail to the maximum stroke (100mm) and then descend. It is observed whether its operation is smooth, without jamming or deviation, to ensure the stability of the subsequent lifting trajectory of the wafer;

[0036] The workers welded the support tube 5 (a 20mm diameter stainless steel tube) to the top center of the movable part 4, and then welded the guide plate 6 (a circular metal plate with a diameter adapted to the wafer) to the upper surface of the support tube 5. A right-angle ruler was used to confirm that the guide plate 6 was perpendicular to the support tube 5. Subsequently, the No. 1 air nozzle interface 9 was welded to the bottom end of the support tube 5 (extending to the bottom of the movable part 4) and connected to the external fan pipeline. The suction cup lifting system 3 was started to lift the movable part 4. A feeler gauge was used to measure the distance between the upper surface of the guide plate 6 and the lower surface of the substrate 2 and adjusted it to 15mm (to reserve space for airflow diffusion).

[0037] The operator places the wafer to be coated (such as an 8-inch silicon wafer) on the vacuum chuck of the movable part 4, and activates the suction cup negative pressure system to ensure that the wafer is firmly adsorbed. Then, the suction cup lifting system 3 is activated to control the movable part 4 to rise along the guide rail, so that the distance between the back of the wafer and the upper surface of the guide plate 6 is maintained at 2-3mm (this distance allows the back-blowing airflow to evenly cover the back of the wafer, avoiding damage to the wafer due to excessive airflow or failure to prevent contamination due to insufficient airflow). The external fan is activated, and the airflow enters the support tube 5 through the No. 1 air nozzle interface 9, is guided into the guide plate 6 through the guide hole 8, and then evenly diffuses to the back of the wafer through the circulation groove 7 (annular groove, 5mm wide) to form a stable airflow field.

[0038] The operator activates the lifting and rotating dispensing system 15, controlling the dispensing needle to descend to 5mm directly above the wafer, and dispenses photoresist at a preset dosage (e.g., 0.5-1mL). After dispensing, the lifting and rotating dispensing system 15 rises and resets, and the moving part 4 drives the wafer to rotate at high speed (3000-5000rpm). Under centrifugal force, the photoresist diffuses towards the edge of the wafer. During this process, the back-blowing airflow continuously acts on the back of the wafer, on the one hand counteracting the turbulent airflow generated by the wafer rotation to avoid uneven thickness of the photoresist layer; on the other hand, blowing away solvent volatiles and gaseous impurities on the back of the wafer to prevent back-side contamination. Excess photoresist is thrown outward under centrifugal force and subsequently collected by the collection mechanism.

[0039] After the wafer is rotated and coated for the preset time, the moving part 4 decelerates to a stop, and the external fan and suction cup negative pressure are turned off; the suction cup lifting system 3 is activated, which drives the moving part 4 to descend to the initial position, and the staff removes the wafer after coating is completed; finally, the trace amount of adhesive mist remaining on the surface of the guide plate 6 is cleaned to prepare for the next coating.

[0040] Example 2:

[0041] This embodiment is basically the same as the previous embodiment, except that the collection mechanism includes a waste liquid collection tank 12. The waste liquid collection tank 12 is fixedly installed on the bottom surface of the substrate 2 near the suction cup lifting system 3. A second air nozzle interface 13 is provided on one side of the bottom end of the waste liquid collection tank 12, and a fixed opening 14 is provided on one side of the upper surface of the waste liquid collection tank 12.

[0042] A connecting pipe is installed at the opening between No. 1 air nozzle interface 9 and No. 2 air nozzle interface 13. A flow rate sensor and a flow control valve are connected to the outer surface of the connecting pipe.

[0043] Working principle: First, based on the operation in Example 1, the operator fixes the waste liquid collection tank 12 (stainless steel, 5L capacity) to the bottom surface of the substrate 2 with bolts, and adjusts the position so that the fixed opening 14 (20mm wide) of the waste liquid collection tank 12 is aligned with the trajectory of excess photoresist thrown out during wafer rotation; then, a PU connecting pipe is installed between the first air nozzle interface 9 and the second air nozzle interface 13, and a flow rate sensor (measuring range 0-20m / s, accuracy ±0.1m / s) and an electromagnetic flow control valve are connected in series on the pipe, and the sensor and valve are connected to the equipment control system to set the airflow velocity threshold (e.g., 5-8m / s).

[0044] Staff tested the linkage function between the flow velocity sensor and the flow control valve by powering on the device and starting the external fan. The airflow entered the support pipe 5 through the No. 1 air nozzle interface 9, and the flow velocity sensor provided real-time feedback on the airflow speed. If the detected flow velocity was lower than 5 m / s, the control system automatically opened the flow control valve to increase the airflow. If the flow velocity was higher than 8 m / s, the valve was closed to ensure stable airflow. At the same time, the No. 2 air nozzle interface 13 was connected to the negative pressure pump, the negative pressure pump was started, and the negative pressure value was adjusted to -0.05 MPa. The suction of the waste liquid collection tank 12 was tested to ensure that it could quickly collect waste liquid.

[0045] When the wafer is rotated at high speed to coat the photoresist, excess photoresist is thrown outward under centrifugal force and falls into the fixed opening 14 of the waste liquid collection tank 12 through the reserved gap below the substrate 2. The negative pressure generated by the negative pressure pump accelerates the flow of waste liquid to the bottom of the tank, preventing waste liquid from remaining or splashing in the tank. During this process, the flow rate sensor continuously monitors the back-blowing airflow. If the airflow is disturbed due to the wafer rotation, the flow control valve is adjusted in real time to maintain the airflow stability and ensure that there is no contamination on the back of the wafer and the photoresist layer is uniform.

[0046] After the homogenization batch is completed, the staff turns off the negative pressure pump and the external fan, removes the drain valve of the waste liquid collection tank 12, and discharges the waste liquid into a special recycling container. At the same time, the staff checks the historical data of the flow rate sensor through the control system to confirm whether the airflow is always within the set range. If abnormal fluctuations occur, the staff checks whether the pipeline is blocked or whether the fan pressure is normal to ensure the stability of subsequent operation.

[0047] Example 3:

[0048] This embodiment is basically the same as the previous embodiment, except that a base plate 11 is provided on the upper surface of the substrate 2 outside the support tube 5, and square holes are symmetrically opened on the upper surface of the base plate 11, with the fixing opening 14 and the square holes aligned with each other.

[0049] Several through holes are provided on the edge of the upper surface of the base plate 11. A threaded groove is provided on the upper surface of the substrate 2 at the position corresponding to the through holes. Several fastening nuts are threadedly connected inside the base plate 11, extending through the through holes and into the threaded groove.

[0050] A cover plate 10 is provided on the outer surface of the support tube 5 near the outside of the base plate 11. The cover plate 10 is welded to the bottom of the guide plate 6, and the cover plate 10 and the base plate 11 are fitted together.

[0051] Working principle: First, the operator aligns the through hole of the base plate 11 (rectangular metal plate, 5mm thick) with the threaded groove on the substrate 2, inserts the fastening nut and tightens it to ensure that the base plate 11 and the substrate 2 are tightly fitted. At this time, the cover plate 10 (annular metal plate, with an inner diameter that matches the support tube 5 and an outer diameter that matches the inner ring of the base plate 11) on the outer surface of the support tube 5 automatically fits into the base plate 11, forming a closed airflow channel to prevent back-blowing airflow from leaking from the gaps and to ensure that the airflow is concentrated on the back side of the wafer. At the same time, the square hole (30mm on each side) of the base plate 11 is adjusted to be fully aligned with the fixed opening 14 of the waste liquid collection tank 12 to ensure that excess photoresist can flow smoothly into the collection tank through the square hole and the fixed opening 14.

[0052] When the external fan is turned on, the back-blowing airflow diffuses to the back of the wafer through the support pipe 5 and the guide plate 6. Since the cover plate 10 and the base plate 11 are fitted and sealed, there is no airflow leakage. The airflow stability detected by the flow rate sensor is 20% higher than that in Example 2. When the wafer is rotated for homogenization, the adhesive layer thickness detection data is observed. It is found that the adhesive layer thickness deviation is controlled within ±2% (better than ±3% in Example 2), which proves the effect of the sealed airflow on improving the homogenization uniformity.

[0053] When it is necessary to clean the guide plate 6 or the circulation channel 7, the staff unscrews the fastening nut of the base plate 11 and removes the base plate 11. At this time, the cover plate 10 remains on the movable part 4 along with the support tube 5. The residual adhesive mist on the surface of the guide plate 6 and the circulation channel 7 can be wiped directly with a lint-free cloth. After cleaning, the base plate 11 is fixed to the substrate 2 again, and the cover plate 10 and the base plate 11 are fitted together again. There is no need to recalibrate the position, which simplifies the maintenance process. At the same time, the detachable design of the base plate 11 also makes it easy to replace the square holes of different sizes (to adapt to different wafer specifications) and improve the equipment compatibility.

[0054] The foregoing has only described certain exemplary embodiments of the present invention by way of illustration. Undoubtedly, those skilled in the art can modify the described embodiments in various ways without departing from the spirit and scope of the present invention. Therefore, the foregoing drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of protection of the claims of the present invention.

Claims

1. A back-blowing mechanism for a uniform adhesive cavity, comprising a support plate (1), wherein a base plate (2) is fixedly mounted on the upper surface of the support plate (1), characterized in that, A suction cup lifting system (3) is provided below the substrate (2). A movable part (4) is installed at the output end of the upper surface of the suction cup lifting system (3). A support tube (5) is provided in the middle of the top of the movable part (4). A guide plate (6) is fixedly installed on the upper surface of the support tube (5). A circulation groove (7) is opened on the upper surface of the guide plate (6). A guide hole (8) is opened through the support tube (5) at the middle of the top of the guide plate (6). A first air nozzle interface (9) is provided at the bottom of the guide hole (8) extending to the lower part of the movable part (4). A collection mechanism is also provided below the substrate (2) for collecting the generated waste liquid.

2. The back-blowing mechanism within the gel-spreading cavity according to claim 1, characterized in that, The collection mechanism includes a waste liquid collection tank (12), which is fixedly installed on the bottom surface of the substrate (2) near the suction cup lifting system (3). A second air nozzle interface (13) is provided on one side of the bottom end of the waste liquid collection tank (12), and a fixed opening (14) is provided on one side of the upper surface of the waste liquid collection tank (12).

3. The back-blowing mechanism within the gel-spreading cavity according to claim 2, characterized in that, A connecting pipe is installed at the opening between the No. 1 air nozzle interface (9) and the No. 2 air nozzle interface (13), and a flow rate sensor and a flow control valve are connected to the outer surface of the connecting pipe.

4. The back-blowing mechanism within the gel-spreading cavity according to claim 2, characterized in that, The substrate (2) has a base plate (11) located outside the support tube (5) on its upper surface. The base plate (11) has square holes symmetrically opened on its upper surface. The fixing opening (14) and the square holes are aligned with each other.

5. The back-blowing mechanism within the gel-spreading cavity according to claim 4, characterized in that, The upper surface of the base plate (11) has several through holes, and the upper surface of the substrate (2) has a threaded groove at the position corresponding to the through holes. The interior of the base plate (11) extends through the through holes to the threaded groove and is threaded with several fastening nuts.

6. The back-blowing mechanism within the gel-spreading cavity according to claim 1, characterized in that, A cover plate (10) is provided on the outer surface of the support tube (5) near the outside of the bottom plate (11). The cover plate (10) is welded to the bottom of the guide plate (6). The cover plate (10) and the bottom plate (11) are fitted together.

7. The back-blowing mechanism within the gel-spreading cavity according to claim 1, characterized in that, The suction cup lifting system (3) has a guide rail fixedly installed at the top. The movable part (4) has guide grooves on both sides that are adapted to the guide rail. The movable part (4) is located inside the guide rail.

8. The back-blowing mechanism within the gel-spreading cavity according to claim 1, characterized in that, A lifting and rotating dispensing system (15) is provided at one end of the upper surface of the substrate (2).

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