Spin coating protection liquid filtering device

Abstract

The utility model discloses a spin -coating protection liquid filter device, include: seriesly arranged first filter unit and second filter unit, and first filter unit and second filter unit are connected through fluid communication component, and the middle part of fluid communication component is equipped with the discharge channel, and its both ends are connected with first filter unit and second filter unit respectively, and the feed end of first filter unit is equipped with feed control part and feed channel, is equipped with exhaust component on first filter unit, and exhaust component includes exhaust channel and on-off control part, and the discharge end of second filter unit is connected with pressure regulating channel, and is equipped with flow regulating part on pressure regulating channel. The utility model has the beneficial effects that: this technical scheme realizes two -stage filtration through double filter unit series connection, and the impurity removal rate is greater than or equal to 99.5%, guarantees the cleanliness of protection liquid, and improves the optical lens coating surface quality.

Description

Technical Field

[0001] This utility model relates to the field of filtration technology, and in particular to a spin-coating protective liquid filtration device. Background Technology

[0002] In the manufacturing of precision devices such as optical lenses and semiconductor wafers, spin coating is a crucial step in forming a uniform protective layer. This process involves delivering a high-viscosity protective liquid (such as acrylate or epoxy resin-based protective adhesives) to the surface of a rotating workpiece, utilizing centrifugal force to form a coating of uniform thickness. This provides scratch protection, contamination isolation, or other process assistance functions for the device surface. The cleanliness, flowability, and delivery stability of the protective liquid directly determine the quality of the spin-coated layer. Therefore, the filtration device, as a core component of the protective liquid delivery system, has a significant impact on the final product yield.

[0003] Currently, most protective liquid filtration devices used in spin coating processes are single-stage filter jug ​​structures, mainly consisting of a filter jug, inlet pipe, outlet pipe, and simple valves. Their working principle is as follows: the protective liquid is driven by a peristaltic pump or pressure pump, enters a single filter jug ​​through the inlet pipe, removes impurities through the built-in filter element, and is then directly delivered to the spin coating nozzle through the outlet pipe. Some devices, to simplify their structure, even omit pressure regulation or venting functions, relying solely on the filter jug's own sealing to meet basic filtration requirements.

[0004] Single-stage filtration devices are simple in structure and low in cost, but in practical applications with high-viscosity protective fluids (viscosity typically 1000-5000 cP), the following key drawbacks have been exposed: Single-stage filter jugs, which filter through only one filter element, have limited effectiveness in retaining tiny particulate impurities (such as gel particles and dust with a diameter of 1-5 μm) in high-viscosity liquids. These residual impurities can cause pinholes, scratches, or uneven thickness in the coating during spin coating, especially in applications with extremely high surface precision requirements, such as optical lenses, where product yield can drop to below 80%.

[0005] During the transportation of high-viscosity protective fluid, the system pressure is prone to drastic fluctuations (ranging from 0.2 to 0.8 MPa) due to the pulsed propulsion of the peristaltic pump or changes in pipeline resistance. Existing equipment lacks an effective pressure regulation mechanism, and long-term high pressure can easily lead to fatigue rupture of the feed pipeline (especially at the hose joint), resulting not only in material waste but also potential contamination of equipment or workpieces due to leakage.

[0006] When the protective fluid is injected into the filter cartridge or the pipeline is changed, air bubbles are easily mixed in. Existing equipment usually relies on the passive vent at the top of the filter cartridge for natural venting, which takes 10-15 minutes and is difficult to completely remove tiny bubbles. If bubbles enter the nozzle with the protective fluid, they will form "bulges" or "voids" on the coating surface, requiring shutdown for cleaning and severely reducing production efficiency.

[0007] Replacing the filter cartridge or feed pipe requires shutting down the entire conveying system and disassembling the pipes, which can easily lead to leakage of protective fluid and secondary air contamination. After restarting, venting and adjustments are necessary again, with each maintenance downtime typically exceeding 30 minutes, significantly impacting the continuity of mass production.

[0008] In view of the problems of low filtration efficiency, unstable pressure, bubble interference and complicated maintenance of existing single-stage filtration devices in the treatment of high viscosity protective liquids, there is an urgent need in the field for an integrated device that integrates high-efficiency filtration, dynamic pressure regulation, rapid venting and convenient maintenance functions. Utility Model Content

[0009] The main technical problem solved by this utility model is to provide a spin-coating protective liquid filtration device, thereby solving one or more of the above-mentioned prior art problems.

[0010] To solve the above-mentioned technical problems, the present invention adopts a technical solution as follows: a spin-coating protective liquid filtration device, the innovation of which is: comprising: A first filter unit and a second filter unit are connected in series, and the first filter unit and the second filter unit are connected by a fluid communication component. The fluid communication component has a discharge channel in the middle, and its two ends are respectively connected to the first filter unit and the second filter unit. The first filter unit is provided with a feed control component and a feed channel at its feed end, and the first filter unit is provided with an exhaust assembly, which includes an exhaust channel and an on / off control component. The discharge end of the second filtration unit is connected to a pressure regulating channel, and the pressure regulating channel is equipped with a flow regulating component.

[0011] In some embodiments, the fluid communication component is a tee connector, the upper and lower ends of which are connected to the first filter unit and the second filter unit respectively, and the middle part forms the discharge channel.

[0012] In some implementations, the feed control component is a ball valve, and the feed channel is a feed pipe.

[0013] In some embodiments, the exhaust passage is an exhaust pipe, and the on / off control component is a switch.

[0014] In some embodiments, the pressure regulating channel is a pressure reducing pipe, and the flow regulating component is a throttle valve.

[0015] In some implementations, the tee connector is mechanically sealed to both the first filter unit and the second filter unit.

[0016] In some implementations, the throttle valve is an adjustable flow type.

[0017] In some implementations, the switch is made of Teflon.

[0018] In some embodiments, both the exhaust channel and the pressure regulating channel flow back to the protective liquid raw material tank. The beneficial effects of this utility model are: this technical solution achieves two-stage filtration by connecting two filter units in series, with an impurity removal rate of ≥99.5%, ensuring the cleanliness of the protective liquid and improving the surface quality of the optical lens coating. Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort, wherein: Figure 1 This is a schematic diagram of the structure of a spin-coating protective liquid filtration device according to the present invention. Detailed Implementation

[0020] The technical solutions in the embodiments of this utility model will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0021] like Figure 1 As shown, the specific implementation of the present invention includes a spin-coating protective liquid filtration device as follows: The spin-coating protective liquid filtration device disclosed in this utility model mainly includes a first filtration unit 4, a second filtration unit 5, a fluid communication component 2, a feed control component 7, an exhaust component, a pressure regulating channel 13, and a flow regulating component 14; the components are connected by pipelines to form a complete integrated filtration-exhaust-pressure reduction system, the specific structure of which is as follows: First filter unit 4 and second filter unit 5 Both the first filter unit 4 and the second filter unit 5 adopt a cylindrical filter jug ​​structure and have built-in high-precision filter elements (such as sintered filter elements with a pore size of 5μm). The two are connected in series through the fluid communication component 2. The volume of the first filter unit 4 is 1.5L and the volume of the second filter unit 5 is 1L. The materials of the first filter unit 4 and the second filter unit 5 are 316L stainless steel, which has strong corrosion resistance and is suitable for high viscosity protective liquids (such as acrylic protective liquids with a viscosity of 1000-5000cP).

[0022] The protective liquid first enters the first filtration unit 4 for primary filtration to remove large particulate impurities (diameter > 5μm), and then enters the second filtration unit 5 for secondary filtration to remove small particulate impurities (diameter > 1μm), thus achieving two-stage progressive filtration.

[0023] The dual-filter unit series design improves filtration accuracy by 40% compared to the traditional single-filter unit structure, effectively preventing impurities from clogging the nozzle or affecting the uniformity of the optical lens coating, and significantly improving product yield.

[0024] Fluid connectivity component 2 The fluid communication component 2 is a T-type tee connector made of 304 stainless steel. Its upper and lower ends are connected to the inlet and outlet ports of the first filter unit 4 and the second filter unit 5 respectively through mechanical seals (such as O-rings + clamps). The middle interface is connected to the discharge pipe.

[0025] The working principle of the fluid communication component 2 is as follows: the protective liquid, after two-stage filtration, enters the central discharge pipe through the upper and lower channels of the tee connector and is directly delivered to the spin coating nozzle without the need for additional transfer components. The mechanical seal connection can withstand a working pressure of 0.6MPa to prevent leakage; the tee connector integrates connection and diversion functions, simplifies pipeline design, reduces pipeline connection points by 30%, and lowers the risk of leakage.

[0026] Feed control component 7 (i.e., ball valve) A one-piece ball valve is installed at the inlet of the first filter unit 4. The valve body is made of stainless steel, and the valve core is made of polytetrafluoroethylene (PTFE). It connects to a DN15 feed pipe. The feed channel 8 is opened and closed by rotating the ball valve handle (0°-90°). When closed, the feed is cut off, facilitating replacement of the feed pipe or maintenance of the filter cartridge. The ball valve has a response time of less than 1 second, making it easy to operate and reducing maintenance downtime by 50% compared to traditional shut-off valves. The PTFE valve core is wear-resistant and can withstand ≥100,000 opening and closing cycles, extending its service life.

[0027] Exhaust system (exhaust pipe and switch) The exhaust assembly includes an exhaust channel 10 and an on / off control component 11. The shoulder of the first filter unit 4 is provided with an exhaust hole with a diameter of 6mm, which is connected to the exhaust channel 10 (50cm in length and 4mm in inner diameter) through a stainless steel pipe. A Teflon rotary switch, i.e., the on / off control component 11, is installed at the end of the pipe.

[0028] Working principle: When the protective liquid enters the first filter unit 4, the on / off control component 11 is opened, and the air (bubbles) in the first filter unit 4 is discharged from the exhaust channel 10 by the liquid flow until no more bubbles flow out of the liquid, then the on / off control component 11 is closed.

[0029] Teflon switches are resistant to chemical corrosion and compatible with organic solvents in protective solutions. Manual adjustment of the switch opening can control the venting rate, preventing liquid splashing. The venting efficiency is 60% higher than that of traditional top venting designs, effectively reducing the impact of air bubbles on pinhole defects in spin-coated coatings.

[0030] Pressure regulating channel 13 (pressure reducing pipeline) and flow regulating component 14 (throttle valve) The outlet of the second filter unit 5 is connected to a pressure reducing pipe, and an adjustable flow throttle valve is connected in series on the pipe.

[0031] Working principle: By rotating the throttle valve knob to change the valve core opening, the return flow rate of the pressure reducing pipeline (0-2L / min) is adjusted, thereby controlling the system pressure (the working pressure is stabilized at 0.2-0.4MPa).

[0032] The throttle valve dynamically adjusts the pressure in real time, which can avoid the sudden increase in pipeline pressure caused by the flow fluctuation of the peristaltic pump (pressure fluctuation range ≤ ±0.05MPa) and prevent the feed pipeline from breaking; the pressure reducing pipeline returns the excess protective fluid to the raw material tank, realizing liquid recycling and reducing raw material loss by 15%.

[0033] Reflux design The ends of the exhaust pipe and the pressure reducing pipe are connected to the protective liquid raw material tank (20L volume) via quick-connect fittings, forming a closed loop.

[0034] Working principle: A small amount of protective liquid carried out during the exhaust process flows back to the raw material tank through the exhaust pipe, and the return liquid in the pressure reducing pipe directly participates in the secondary filtration to avoid waste.

[0035] The entire system produces no waste liquid, meeting the requirements of green production; the circulation design keeps the protective liquid in a flowing state during the filtration process, preventing high-viscosity liquids from settling and separating.

[0036] The working principle of this technical solution is as follows: the protective liquid enters the first filter unit 4 through the feed pipe and ball valve, and after passing through two stages of filter jugs, it is transported to the spin coating nozzle through the discharge pipe in the middle of the three-way connector; during the filtration process, the air bubbles in the first filter unit 4 are discharged through the exhaust switch, and the return flow of the pressure reducing pipe is adjusted through the throttle valve to stabilize the system pressure; excess liquid is returned to the raw material tank for recycling through the exhaust pipe and pressure reducing pipe.

[0037] The advantages of this technical solution are: High-efficiency filtration: Dual filtration units connected in series achieve two-stage filtration, with an impurity removal rate of ≥99.5%, ensuring the cleanliness of the protective liquid and improving the surface quality of the optical lens coating (defect rate reduced to below 0.3%).

[0038] Stable pressure: The throttle valve dynamically regulates the pressure to avoid excessive pipeline pressure (maximum working pressure controlled within 0.6MPa), extending pipeline service life by more than 3 times.

[0039] Easy to operate: The ball valve can be quickly switched on and off, and the Teflon exhaust switch can be precisely adjusted, reducing equipment maintenance time to 5 minutes per operation and improving production continuity.

[0040] Compact structure: It integrates filtration, exhaust and pressure reduction functions, and the equipment occupies only 0.1㎡, making it suitable for small workshop layouts.

[0041] Cost savings: The recirculation design reduces raw material waste, saving approximately 20,000 yuan in protective fluid costs annually; the replacement cycle for vulnerable parts (such as filter elements and sealing rings) is extended to 3 months, reducing maintenance costs.

[0042] This device is particularly suitable for spin coating protective layers on optical lenses, and can meet the precision filtration requirements of high-viscosity protective liquids (1000-5000 cP), significantly improving the stability of the spin coating process and product yield.

[0043] The above description is merely an embodiment of this utility model and does not limit the patent scope of this utility model. Any equivalent structural or procedural transformations made based on the content of this utility model specification, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this utility model.

Claims

1. A spin-coating protective liquid filtration device, characterized in that: include: A first filter unit (4) and a second filter unit (5) are connected in series, and the first filter unit (4) and the second filter unit (5) are connected by a fluid communication component (2); The fluid communication component (2) is provided with a discharge channel (3) in the middle, and its two ends are respectively connected to the first filter unit (4) and the second filter unit (5); The first filter unit (4) is provided with a feed control component (7) and a feed channel (8) at the feed end. The first filter unit (4) is provided with an exhaust assembly, which includes an exhaust channel (10) and an on / off control component (11). The discharge end of the second filter unit (5) is connected to a pressure regulating channel (13), and the pressure regulating channel (13) is provided with a flow regulating component (14).

2. The spin-coating protective liquid filtration device according to claim 1, characterized in that: The fluid communication component (2) is a three-way connector. The upper and lower ends of the three-way connector are respectively connected to the first filter unit (4) and the second filter unit (5), and the middle part forms the discharge channel (3).

3. The spin-coating protective liquid filtration device according to claim 1, characterized in that: The feed control component (7) is a ball valve, and the feed channel (8) is a feed pipe.

4. The spin-coating protective liquid filtration device according to claim 1, characterized in that: The exhaust passage (10) is an exhaust pipe, and the on / off control component (11) is a switch.

5. The spin-coating protective liquid filtration device according to claim 1, characterized in that: The pressure regulating channel (13) is a pressure reducing pipe, and the flow regulating component (14) is a throttle valve.

6. The spin-coating protective liquid filtration device according to claim 2, characterized in that: The three-way connector is mechanically sealed to both the first filter unit (4) and the second filter unit (5).

7. The spin-coating protective liquid filtration device according to claim 5, characterized in that: The throttle valve is an adjustable flow type.

8. The spin-coating protective liquid filtration device according to claim 4, characterized in that: The switch is made of Teflon.

9. A spin-coating protective liquid filtration device according to claim 4 or 5, characterized in that: Both the exhaust channel (10) and the pressure regulating channel (13) flow back to the protective liquid raw material tank.

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