Equipment for coating large-area circular film

Abstract

The invention discloses equipment for coating a large-area circular film, and belongs to the technical field of coating equipment. The equipment for coating the large-area circular thin film comprises a truss, a distance adjusting mechanism, a rotating table and a feeding device, and further comprises a coating head which is arranged above the rotating table and is arranged in the radial direction of a wafer substrate, the coating head is provided with a coating slit and a plurality of feeding ports, the feeding ports are arranged in the length direction of the coating slit, and the feeding ports are arranged in the length direction of the coating slit; the plurality of feeding holes are communicated with different positions of the coating slit; and the flow speed regulator is used for sequentially increasing or reducing the feeding speed of each feeding hole from the feeding hole at the near end of the coating head to the feeding hole at the far end of the coating head according to a preset flow speed gradient in the process of increasing or reducing the distance between the far end of the coating head and the upper surface of the wafer substrate. According to the equipment for coating the large-area circular thin film, in the coating process of the wafer substrate, it can be guaranteed that the thickness of the film formed on the wafer substrate is stable and uniform, and the coating quality of the wafer substrate is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of coating equipment, in particular to equipment for coating large-area circular films. Background Art

[0002] Across numerous industrial production processes, large-area circular films are widely used in critical processes such as capacitor manufacturing, optical component production, and electronic packaging. For example, the performance of thin-film capacitors depends directly on the quality of the circular film coating used. High-quality coatings can significantly reduce the capacitor's equivalent series resistance (ESR), improving its charge and discharge efficiency and stability, thereby meeting the stringent demands for high-performance capacitors in emerging industries such as new energy vehicles and photovoltaic inverters.

[0003] Currently, spin coating is commonly used when coating disc-shaped wafer substrates. The specific process is as follows: a rotating table drives the wafer substrate to rotate, while a coating head above the wafer substrate coats its upper surface. The coating liquid sprayed from the coating slit of the coating head has a certain speed gradient from the inner side of the wafer substrate to the outer side of the wafer. To ensure the thickness of the coating layer is uniform, the height between one end of the coating head and the upper surface of the wafer substrate is adjusted during the coating process using a spacing adjustment mechanism to ensure that the coating head and the upper surface of the wafer substrate remain level.

[0004] However, in the process of adjusting the coating head of the existing coating equipment, the flow rate gradient adjustment of the coating slit of the coating head has a certain lag, which easily leads to the spraying speed of the coating slit being difficult to adapt to the gradually changing amount of coating liquid from the axis to the edge of the coating film on the wafer substrate after adjustment, making the coating liquid unevenly distributed on the surface of the circular film, making it difficult to guarantee the quality of the coating and difficult to ensure the formation of a uniform film layer on the wafer substrate. Summary of the Invention

[0005] The purpose of the present invention is to overcome the problems in the prior art and provide a device for coating large-area circular thin films. During the coating process of the wafer substrate, the coating liquid can be evenly distributed on the wafer substrate, so that the film thickness formed on the wafer substrate is stable and uniform, thereby improving the coating quality of the wafer substrate.

[0006] The present invention provides an apparatus for coating a large-area circular film, comprising a truss, a spacing adjustment mechanism, a rotating table, and a feeding device, and further comprising: A coating head is provided above the rotating table and arranged along the radial direction of the wafer substrate, the proximal end of the coating head is located above the axis of the wafer substrate and is connected to the truss, the distal end of the coating head is close to the outer edge of the wafer substrate and is connected to the spacing adjustment mechanism, the coating head is provided with a coating slit and a plurality of feed ports, the coating slit is arranged along the length direction of the coating head, the plurality of feed ports are arranged along the length direction of the coating slit, and the plurality of feed ports are connected to different positions of the coating slit; A flow rate regulator is connected to multiple feed ports, and the flow rate regulator is connected to the feeding device. The flow rate regulator is used to increase or decrease the feed rate of each feed port in sequence from the feed port at the proximal end of the coating head to the feed port at the distal end of the coating head according to a predetermined flow rate gradient during the process of increasing or decreasing the distance between the distal end of the coating head and the upper surface of the wafer substrate. The absolute value of the gradient difference of the predetermined flow rate gradient is proportional to the amplitude of the increase or decrease of the distance.

[0007] Preferably, the flow rate regulator is provided with a through-hole and a plurality of cavities, each feed port is connected to a cavity, each cavity is connected to a regulating valve, each regulating valve is connected to the through-hole, and the through-hole is connected to the feeding device. When the distance between the proximal end of the coating head and the upper surface of the wafer substrate increases, under the action of the multiple regulating valves, the feed speed of each feed port is increased sequentially from the feed port at the proximal end of the coating head to the feed port at the distal end of the coating head according to a predetermined flow rate gradient.

[0008] Preferably, the regulating valve includes a valve stem and a valve core, the flow rate regulator is provided with a vertical sliding hole, the valve stem is slidably connected to the sliding hole, the bottom end of the sliding hole is provided with a valve cavity, one end of the valve cavity is connected to the flow hole, and the other end of the valve cavity is connected to the cavity body, the valve core is provided in the valve cavity, and the bottom end of the valve stem is connected to the valve core. When the valve stem is slid in the vertical direction, the valve core can be driven to move, thereby changing the flow area of the valve cavity to change the feeding speed of the cavity.

[0009] Preferably, a spring is provided outside the valve stem, and the spring is used to apply a vertical upward elastic force to the valve stem. Under the action of the spring elastic force, the top end of the valve stem abuts against the truss. When the coating head moves upward relative to the valve stem, the valve core moves downward relative to the valve cavity, the flow area of the valve cavity increases, and the feeding speed of the cavity increases.

[0010] Preferably, the spacing adjustment mechanism includes a pull rod and a driving mechanism, the bottom end of the pull rod is rotatably connected to the distal end of the coating head, and a stop block is provided at the bottom end of the pull rod. The stop block is used to apply vertical force to the distal end of the coating head. The lifting mechanism is connected to the proximal end of the coating head through a truss, and the truss is provided with a vertical threaded hole. The top end of the pull rod is provided with an external thread, and the top end of the pull rod is connected to the threaded hole through the external thread. The driving mechanism is connected to the top end of the pull rod, and the controller is electrically connected to the driving mechanism. The driving mechanism is used to drive the pull rod to rotate.

[0011] Preferably, the driving mechanism includes a sleeve and a power unit, the sleeve is vertically arranged and rotatably connected to the truss, a gear is provided on the outside of the sleeve, the sleeve is gear-connected with the power unit through the gear, the controller is electrically connected to the power unit, the top end of the pull rod is slidably connected to the sleeve hole of the sleeve, a vertical limiting groove is provided in the sleeve hole, a limiting slider is slidably connected in the limiting groove, the limiting slider is connected to the top end of the pull rod, the limiting groove and the limiting slider are used to prevent the pull rod from rotating relative to the sleeve.

[0012] Preferably, the width of the coating head gradually increases from the axis of the wafer substrate to the outer edge of the wafer substrate.

[0013] Preferably, a lifting mechanism is connected to the truss, and the lifting mechanism is used to adjust the distance between the truss and the wafer substrate.

[0014] Preferably, the proximal end of the coating head is detachably connected to the truss.

[0015] Preferably, the lower end of the coating head is provided with a wear-resistant coating.

[0016] Compared with the prior art, the beneficial effects of the present invention are: a device for coating a large-area circular thin film of the present invention controls the action of the spacing adjustment mechanism to keep the coating head and the wafer substrate level, controls the flow rate regulator to increase the feed rate of each feed port in sequence from the feed port at the proximal end of the coating head to the feed port at the distal end of the coating head according to a predetermined flow rate gradient, so that the coating slit of the coating head increases gradually with a certain gradient from the axis of the upper surface of the wafer substrate to the outer edge of the upper surface of the wafer substrate, and conversely, the adjustment process of the flow rate regulator is opposite, so that the jet rate of the coating liquid discharged from the coating head gradually decreases with a certain gradient, thereby adapting to the thickness gradient of the incremental coating layer from the axis of the wafer substrate to the outer edge of the wafer substrate, and can ensure the uniformity of the distribution of the coating liquid on the wafer substrate, so that the film thickness formed on the wafer substrate is stable and uniform, thereby improving the coating quality of the wafer substrate.

[0017] Through the joint action of multiple cavities and multiple regulating valves, the jet velocity of the coating liquid discharged from the coating slit of the coating head gradually increases or decreases from the axis side of the wafer substrate to the outer edge of the wafer substrate, thereby preventing the coating liquid at the axis center of the wafer substrate and the coating liquid at the outer edge of the wafer substrate from being unevenly distributed, further ensuring the uniformity of the film thickness after coating. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the main structure of the present invention; Figure 2 It is a schematic diagram of the top view of the structure of the present invention; Figure 3Schematic diagram of the internal structure of the present invention; Figure 4 Schematic diagram of the AA surface structure of the present invention; Figure 5 A schematic structural diagram of the spacing adjustment mechanism of the present invention; Figure 6 Schematic diagram of the structure of the regulating valve of the present invention; Figure 7 Schematic diagram of the coating head adjustment of the present invention.

[0019] Description of reference numerals: 1. Wafer substrate, 101. Rotating table, 102. Coating head, 103. Lifting mechanism, 104. Coating slit, 105. Spacing adjustment mechanism, 201. Pull rod, 202. Driving mechanism, 203. Stopper, 204. Truss, 301. Sleeve, 302. Power unit, 303. Gear, 304. Limiting slide, 305. Limiting slider, 401. Feed inlet, 402. Flow rate regulator, 403. Flow hole, 404. Cavity, 405. Control valve, 501. Valve stem, 502. Valve core, 503. Valve cavity, 6. Spring, 7. Clamping mechanism. DETAILED DESCRIPTION

[0020] The following is combined with Figure 1-Figure 7 , the specific embodiments of the present invention are described in detail, but it should be understood that the scope of protection of the present invention is not limited by the specific embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0021] like Figure 1-Figure 7As shown, the present invention provides an apparatus for coating a large-area circular film, comprising a truss 204, a lifting mechanism 103, a macrometer, a spacing adjustment mechanism 105, a rotating table 101 and a feeding device, wherein the rotating table 101 is used to drive the wafer substrate 1 to rotate, and further comprises: a coating head 102 and a flow rate regulator 402, the coating head 102 being arranged above the rotating table 101 and radially along the wafer substrate 1, the proximal end of the coating head 102 being located above the axis of the wafer substrate 1 and connected to the truss 204, the distal end of the coating head 102 being close to the outer edge of the wafer substrate 1 and connected to the spacing adjustment mechanism 105, the coating head 102 being provided with a coating slit 104 and a plurality of feed ports 401, the coating slit 104 It is arranged along the length direction of the coating head 102, and the multiple feed ports 401 are arranged along the length direction of the coating slit 104, and the multiple feed ports 401 are connected to different positions of the coating slit 104; the flow rate regulator 402 is connected to the multiple feed ports 401, and the flow rate regulator 402 is connected to the feeding device. The flow rate regulator 402 is used to increase or decrease the feed speed of each feed port 401 from the feed port 401 at the proximal end of the coating head 102 to the feed port 401 at the distal end of the coating head 102 according to a predetermined flow rate gradient during the process of increasing or decreasing the distance between the distal end of the coating head 102 and the upper surface of the wafer substrate 1. The absolute value of the gradient difference of the predetermined flow rate gradient is proportional to the amplitude of the increase or decrease of the distance.

[0022] The working principle of the above embodiment is briefly described below: The lifting mechanism 103 of the device is connected to the truss 204. The lifting mechanism 103 is used to adjust the distance between the truss 204 and the upper surface of the wafer substrate 1. The macrometer is set on the truss 204. When the device is in use, the wafer substrate 1 is fixed on the rotating table 101, and then the coating liquid is supplied to the coating head 102 through the feeding device. At the same time, the rotating table 101 is controlled to rotate, and the rotating table 101 drives the wafer substrate 1 to rotate, thereby coating the upper surface of the wafer substrate 1. Figure 7As shown, during this process, the distance A between the proximal end of the coating head 102 and the upper surface of the wafer substrate 1 at the axis center, and the distance B between the distal end of the coating head 102 and the upper surface of the wafer substrate 1 at the outer edge are measured in real time by a macrometer. The controller controls the lifting mechanism 103 to adjust the height of the truss 204 based on the relationship between the distance A and the predetermined distance H, thereby adjusting the size of the distance A so that the distance A is equal to the predetermined distance H, and comparing the distance B with the predetermined distance H. When the distance B is smaller than the predetermined distance H, the distance adjustment mechanism 105 is controlled to operate, thereby increasing the distance B so that the distance B is equal to the predetermined distance H, so that the coating head 102 and the wafer substrate 1 are kept horizontal. During this process, the height difference between the height line of the original coating slit 104 before adjustment and the height line of the coating slit 104 after adjustment is a certain gradient from the axis center (central axis) of the wafer substrate 1 to the outer edge of the wafer substrate 1. The coating speed increases. At this time, the flow rate regulator 402 (which can be a plurality of sequentially adjustable electromagnetic flow rate regulating valves) is controlled to increase the feed speed of each feed port 401 in sequence from the feed port 401 at the proximal end of the coating head 102 to the feed port 401 at the distal end of the coating head 102 according to a predetermined flow rate gradient, so that the coating slit 104 of the coating head 102 is discharged from the axis of the upper surface of the wafer substrate 1 to the outer edge of the upper surface of the wafer substrate 1. The jet speed of the coating liquid is a certain gradient. Gradually increases, on the contrary, when reducing the spacing B to the predetermined spacing H, the adjustment process of the flow rate regulator 402 is opposite, so that the jet speed of the coating liquid discharged by the coating head 102 gradually decreases with a certain gradient, thereby adapting to the thickness gradient of the incremental coating layer from the axis of the wafer substrate 1 to the outer edge of the wafer substrate 1, and ensuring the uniformity of the distribution of the coating liquid on the wafer substrate 1, so that the film thickness formed on the wafer substrate 1 is stable and uniform, thereby improving the coating quality of the wafer substrate 1.

[0023] The device for coating large-area circular thin films of the present invention can, during the coating process of the wafer substrate 1, level the coating head 102 to adapt to the demand for the amount of coating liquid due to the thickness gradient of the incremental coating layer from the axis of the wafer substrate 1 to the outer edge of the wafer substrate 1, and can ensure the uniformity of the distribution of the coating liquid on the wafer substrate 1, so that the film thickness formed on the wafer substrate 1 is stable and uniform, thereby improving the coating quality of the wafer substrate 1.

[0024] On the basis of the above embodiment, in order to prevent the coating liquid at the axis of the wafer substrate 1 and the coating liquid at the outer edge of the wafer substrate 1 from being unevenly distributed, the uniformity of the thickness of the film after coating is further ensured.

[0025] like Figure 1 、 Figure 3 、 Figure 4 and Figure 6As shown, the flow rate regulator 402 is provided with a flow hole 403 and a plurality of cavities 404, each feed port 401 is connected to a cavity 404, each cavity 404 is connected to a regulating valve 405, each regulating valve 405 is connected to the flow hole 403, and the flow hole 403 is connected to the feeding device. When the distance between the proximal end of the coating head 102 and the upper surface of the wafer substrate 1 increases, under the action of the multiple regulating valves 405, the feed rate of each feed port 401 is increased in sequence from the feed port 401 at the proximal end of the coating head 102 to the feed port 401 at the distal end of the coating head 102 according to a predetermined flow rate gradient.

[0026] The feeding device feeds the coating liquid into the multiple cavities 404 through the flow hole 403. After each cavity 404 is filled with the coating liquid, the coating liquid is fed into the feed port 401 connected to the cavity 404. Since the multiple feed ports 401 are arranged along the length direction of the coating head 102 and under the action of the multiple regulating valves 405, when the distance between the distal end of the coating head 102 and the upper surface of the wafer substrate 1 increases, under the action of the multiple regulating valves 405, the feeding speed of each feed port 401 is increased in sequence from the feed port 401 at the proximal end of the coating head 102 to the feed port 401 at the distal end of the coating head 102 according to a predetermined flow rate gradient; and vice versa. Through the joint action of multiple cavities 404 and multiple regulating valves 405, the jet velocity of the coating liquid discharged from the coating slit 104 of the coating head 102 gradually increases or decreases from the axis side of the wafer substrate 1 to the outer edge of the wafer substrate 1, thereby preventing the coating liquid at the axis center of the wafer substrate 1 and the coating liquid at the outer edge of the wafer substrate 1 from being unevenly distributed, further ensuring the uniformity of the film thickness after coating.

[0027] As a preferred solution, Figure 1 、 Figure 3 、 Figure 4 and Figure 6As shown, the regulating valve 405 includes a valve stem 501 and a valve core 502. The flow rate regulator 402 is provided with a vertical sliding hole. The valve stem 501 is slidably connected to the sliding hole. The bottom end of the sliding hole is provided with a valve cavity 503. One end of the valve cavity 503 is connected to the flow hole 403, and the other end of the valve cavity 503 is connected to the cavity 404. The valve core 502 is provided in the valve cavity 503, and the bottom end of the valve stem 501 is connected to the valve core 502. When the valve stem 501 is slid in the vertical direction, the valve core 502 can be driven to move, thereby changing the flow area of the valve cavity 503 to change the feed rate of the cavity 404. The feeding device feeds the coating liquid into the flow hole 403, and the coating liquid enters the valve cavity 503 through the flow hole 403, and then enters the cavity 404 connected to it after passing through the valve cavity 503, and then enters the feed port 401 of the coating head 102. By sliding the valve stem 501 in the vertical direction, the valve core 502 is driven to move relative to the valve cavity 503, thereby changing the flow area of the valve cavity 503, thereby changing the flow rate of the coating liquid entering the feed port 401, and then changing the discharge rate of the coating slit 104 of the coating head 102, so as to adapt to the gradually changing amount of coating liquid from the axis to the edge of the coating film on the wafer substrate 1 after adjustment.

[0028] As a preferred solution, Figure 3 and Figure 6 As shown, a spring 6 is provided outside the valve stem 501, and the spring 6 is used to apply a vertical upward elastic force to the valve stem 501. Under the action of the elastic force of the spring 6, the top of the valve stem 501 abuts against the truss 204. When the coating head 102 moves upward relative to the valve stem 501, the valve core 502 moves downward relative to the valve cavity 503, the flow area of the valve cavity 503 increases, and the feeding speed of the cavity 404 increases. When the spacing adjustment mechanism 105 lifts the coating head 102 near the outer edge of the wafer substrate 1, the spacing between the coating head 102 near the outer edge of the wafer substrate 1 and the upper surface of the wafer substrate 1 increases, so as to increase the thickness of the film coated on the wafer substrate 1. Since the top end of the valve stem 501 abuts against the truss 204, the coating head 102 moves upward relative to the valve stem 501, and the valve core 502 moves downward relative to the valve cavity 503, so that the flow area of the valve cavity 503 increases, thereby increasing the discharge speed of the coating head 102 near the outer edge of the wafer substrate 1, so as to prevent the coating head 102 from discharging insufficient material and causing coating interruption when the coating head 102 increases the film thickness coated at the outer edge of the wafer substrate 1, thereby further ensuring the uniformity of the thickness of the coated film.

[0029] As a preferred solution, Figures 1-6As shown, the spacing adjustment mechanism 105 includes a pull rod 201 and a driving mechanism 202. The bottom end of the pull rod 201 is rotatably connected to the distal end of the coating head 102. A stop block 203 is provided at the bottom end of the pull rod 201. The stop block 203 is used to apply a vertical force to the distal end of the coating head 102. The lifting mechanism 103 is connected to the proximal end of the coating head 102 through a truss 204. The truss 204 is provided with a vertical threaded hole. The top end of the pull rod 201 is provided with an external thread. The top end of the pull rod 201 is connected to the threaded hole through the external thread. The driving mechanism 202 is connected to the top end of the pull rod 201. The controller is electrically connected to the driving mechanism 202. The driving mechanism 202 is used to drive the pull rod 201 to rotate. When adjusting the distance B between the distal end of the coating head 102 and the upper surface of the wafer substrate 1, the controller controls the driving mechanism 202 to move, thereby driving the pull rod 201 to rotate, and the pull rod 201 rotates relative to the threaded hole. Under the action of the external thread on the pull rod 201, the pull rod 201 moves in the vertical direction, thereby driving the block 203 to move in the vertical direction. Since the block 203 can apply a vertical force to the distal end of the coating head 102, the distal end of the coating head 102 is driven to rise or fall, thereby adjusting the distance B, thereby adjusting the posture of the coating head 102 to ensure that the coating head 102 is always parallel to the upper surface of the wafer substrate 1. At the same time, the movement of the valve stems 501 of the multiple regulating valves 405 is more precise, and the flow rate of the regulating valve 405 is adjusted more accurately, thereby further ensuring the uniformity of the film thickness coated on the wafer substrate 1.

[0030] As a preferred solution, Figure 3 and Figure 5As shown, the driving mechanism 202 includes a sleeve 301 and a power unit 302, the sleeve 301 is vertically arranged and rotatably connected to the truss 204, a gear 303 is provided on the outside of the sleeve 301, the sleeve 301 is gear-connected with the power unit 302 through the gear 303, the controller is electrically connected to the power unit 302, the top end of the pull rod 201 is slidably connected to the sleeve hole of the sleeve 301, a vertical limiting groove 304 is provided in the sleeve hole, a limiting slider 305 is slidably connected in the limiting groove 304, and the limiting slider 305 is connected to the top end of the pull rod 201, the limiting groove 304 and the limiting slider 305 are used to prevent the pull rod 201 from rotating relative to the sleeve 301. When adjusting the distance B between the distal end of the coating head 102 and the upper surface of the wafer substrate 1, the controller controls the power device 302 to move, thereby driving the sleeve 301 to rotate through the gear 303. When the sleeve 301 rotates, the limit slide groove 304 and the limit slider 305 drive the pull rod 201 to rotate. Under the action of the external thread on the pull rod 201, the pull rod 201 can be driven to move in the vertical direction, and the pull rod 201 slides in the vertical direction relative to the sleeve hole in the sleeve 301. During this process, the sleeve 301 is always geared with the power device 302 through the gear 303, thereby ensuring that the power device 302 can always drive the pull rod 201 to rotate through the sleeve 301, thereby ensuring that the distance B between the distal end of the coating head 102 and the upper surface of the wafer substrate 1 can always be adjusted, thereby ensuring that the distance B is always equal to the predetermined distance H, further ensuring the uniformity of the thickness of the film coated on the wafer substrate 1.

[0031] As a preferred solution, Figure 3 and Figure 6 As shown, the width of the coating slit 104 gradually increases from the axis of the wafer substrate 1 to the outer edge of the wafer substrate 1. The coating slit 104 on the coating head 102 gradually increases from the axis of the wafer substrate 1 to the outer edge of the wafer substrate 1 to adapt to the linear change of the linear velocity of the wafer substrate 1 from near the axis to the outer edge of the wafer, thereby ensuring the consistency of the film thickness on the wafer substrate 1.

[0032] As a preferred solution, Figure 1-Figure 3 As shown, the truss 204 is connected to a lifting mechanism 103, which is used to adjust the distance between the truss 204 and the wafer substrate 1. By setting up the lifting mechanism 103, the distance between the truss 204 and the wafer substrate 1 is adjusted by using the lifting mechanism 103, thereby adjusting the distance between the proximal end of the coating head 102 and the axis position of the upper surface of the wafer substrate 1, thereby adjusting the thickness of the entire coating layer.

[0033] As a preferred solution, Figure 1 and Figure 3As shown, the proximal end of the coating head 102 is detachably connected to the truss 204. The proximal end of the coating head 102 and the truss 204 are detachably connected, which can facilitate the disassembly and installation of the coating head 102, thereby facilitating the maintenance of the entire device.

[0034] As a preferred solution, Figure 2 and Figure 3 As shown, the rotating table 101 is provided with a clamping mechanism 7, which is used to clamp the wafer substrate 1. When the clamping mechanism 7 clamps the wafer substrate 1, the axis of the wafer substrate 1 coincides with the rotation axis of the rotating table 101. By providing the clamping mechanism 7, the rotating table 101 clamps the wafer substrate 1 through the clamping mechanism 7. When the rotating table 101 drives the wafer substrate 1 to rotate through the clamping mechanism 7, the smooth rotation of the wafer substrate 1 can be ensured, thereby ensuring the stability of the entire coating process and the uniformity of the thickness of the coated film.

[0035] While the embodiments of the present invention have been shown and described, it will be apparent to those skilled in the art that various changes, modifications, substitutions, and alterations can be made to the embodiments without departing from the principles and spirit of the invention.

Claims

1. A device for coating a large-area circular film, comprising a truss, a spacing adjustment mechanism, a rotating table and a feeding device, characterized in that: Also includes: A coating head is provided above the rotating table and arranged along the radial direction of the wafer substrate, the proximal end of the coating head is located above the axis of the wafer substrate and is connected to the truss, the distal end of the coating head is close to the outer edge of the wafer substrate and is connected to the spacing adjustment mechanism, the coating head is provided with a coating slit and a plurality of feed ports, the coating slit is arranged along the length direction of the coating head, the plurality of feed ports are arranged along the length direction of the coating slit, and the plurality of feed ports are connected to different positions of the coating slit; A flow rate regulator is connected to multiple feed ports, and the flow rate regulator is connected to the feeding device. The flow rate regulator is used to increase or decrease the feed rate of each feed port in sequence from the feed port at the proximal end of the coating head to the feed port at the distal end of the coating head according to a predetermined flow rate gradient during the process of increasing or decreasing the distance between the distal end of the coating head and the upper surface of the wafer substrate. The absolute value of the gradient difference of the predetermined flow rate gradient is proportional to the amplitude of the increase or decrease of the distance.

2. The device for coating a large-area circular film according to claim 1, characterized in that: The flow rate regulator is provided with a through-hole and multiple cavities, each feed port is connected to a cavity, each cavity is connected to a regulating valve, each regulating valve is connected to the through-hole, and the through-hole is connected to the feeding device. When the distance between the proximal end of the coating head and the upper surface of the wafer substrate increases, under the action of the multiple regulating valves, the feed speed of each feed port is increased sequentially from the feed port at the proximal end of the coating head to the feed port at the distal end of the coating head according to a predetermined flow rate gradient.

3. The device for coating a large-area circular film according to claim 2, characterized in that: The regulating valve includes a valve stem and a valve core. The flow rate regulator is provided with a vertical sliding hole. The valve stem is slidably connected to the sliding hole. The bottom end of the sliding hole is provided with a valve cavity. One end of the valve cavity is connected to the flow hole, and the other end of the valve cavity is connected to the cavity body. The valve core is arranged in the valve cavity, and the bottom end of the valve stem is connected to the valve core. When the valve stem is slid in the vertical direction, the valve core can be driven to move, thereby changing the flow area of the valve cavity to change the feeding speed of the cavity.

4. The device for coating a large-area circular film according to claim 3, characterized in that: A spring is provided outside the valve stem, and the spring is used to apply a vertical upward elastic force to the valve stem. Under the action of the spring elastic force, the top end of the valve stem abuts against the truss. When the coating head moves upward relative to the valve stem, the valve core moves downward relative to the valve cavity, the flow area of the valve cavity increases, and the feeding speed of the cavity increases.

5. The device for coating a large-area circular film according to claim 1, characterized in that: The spacing adjustment mechanism includes a pull rod and a driving mechanism. The bottom end of the pull rod is rotatably connected to the distal end of the coating head. A block is provided at the bottom end of the pull rod. The block is used to apply vertical force to the distal end of the coating head. The lifting mechanism is connected to the proximal end of the coating head through a truss. The truss is provided with a vertical threaded hole. The top end of the pull rod is provided with an external thread. The top end of the pull rod is connected to the threaded hole through the external thread. The driving mechanism is connected to the top end of the pull rod. The controller is electrically connected to the driving mechanism. The driving mechanism is used to drive the pull rod to rotate.

6. The device for coating a large-area circular film according to claim 5, characterized in that: The driving mechanism includes a sleeve and a power device. The sleeve is vertically arranged and rotatably connected to the truss. A gear is provided on the outside of the sleeve. The sleeve is gear-connected to the power device through the gear. The controller is electrically connected to the power device. The top end of the pull rod is slidably connected to the sleeve hole of the sleeve. A vertical limiting groove is provided in the sleeve hole. A limiting slider is slidably connected in the limiting groove. The limiting slider is connected to the top end of the pull rod. The limiting groove and the limiting slider are used to prevent the pull rod from rotating relative to the sleeve.

7. The device for coating a large-area circular film according to claim 1, characterized in that: The coating slit width gradually increases from the axis of the wafer substrate to the outer edge of the wafer substrate.

8. The device for coating a large-area circular film according to claim 1, wherein: The truss is connected to a lifting mechanism, and the lifting mechanism is used to adjust the distance between the truss and the wafer substrate.

9. The device for coating a large-area circular film according to claim 1, characterized in that: The proximal end of the coating head is detachably connected to the truss.

10. The device for coating a large-area circular film according to claim 1, characterized in that: The lower end of the coating head is provided with a wear-resistant coating.

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