Coating die head and coating equipment with uniform material discharge

Abstract

The present invention discloses a coating die head and coating equipment with uniform material discharge, belonging to the field of coating equipment. In the coating die head, the end of the diversion channel divides into a plurality of diversion ports connected to the beginning of the diffusion channel, the diffusion channel is inclined downward, and a buffer column is arranged on the line connecting the beginning and the end of the buffer cavity. The widths of the diffusion channel, the buffer column and the buffer cavity are all equal to the coating width of the slit lip, and the supporting member includes a first supporting column arranged in the buffer column and a second supporting column arranged outside the buffer cavity. The coating die head makes greater use of the gravity effect to make the fluid spread over the internal space of the coating die head in the width direction, which is conducive to relaxing the flow rate requirements for the fluid entering the cavity; the second supporting column is used to support the coating die head body, and the first supporting column independently supports the buffer column and auxiliary supports the coating die head body, which is conducive to suppressing the deformation of the slit lip caused by its own weight; the multi-cavity uniformity design and the weight distribution design make the fluid more uniform before and during coating.

Description

Technical Field

[0001] The invention relates to a coating die head with uniform material discharge and coating equipment, belonging to the field of coating equipment. Background Art

[0002] Coating dies can be used for TFT photolithography, OLED (organic light-emitting diode) display manufacturing, and LCD color filter film manufacturing. The key design point of the coating die is to make the material discharge uniformly.

[0003] The existing coating die heads currently use a single-cavity uniformity design, with a hemispherical, semi-cylindrical or semi-tear-shaped cavity to achieve the purpose of buffering and improving uniformity. The flow rate of the fluid entering the cavity and the size of the coating outlet cross-sectional area need to be coordinated to achieve the desired uniformity effect. Therefore, there are great restrictions on the flow rate and speed of the fluid entering the cavity, the application range of a single machine is narrow, and the buffer structure still needs to be improved.

[0004] In addition, the internal structure of the current coating die is not evenly distributed, making it difficult to apply to large-size coatings. The uneven distribution of the internal structure leads to an imbalance in the weight ratio. When a large-size die is made according to the existing design, the die's own weight plus the weight of the fluid will cause the die to deform slightly. The coating slit is also very sensitive to this slight deformation. For example, an 80μm coating slit is partially narrowed to 50μm, which is almost invisible from the outside, but will seriously affect the uniformity of the coating. Summary of the invention

[0005] In order to overcome the shortcomings of the prior art, the present invention provides a coating die head and coating equipment with uniform material discharge, which has a multi-level buffer structure and optimizes the distribution of the internal structure, so that the material discharge is more uniform.

[0006] The technical solution adopted by the present invention to solve its technical problem is:

[0007] In the first aspect, the present application provides a coating die head with uniform discharge, including a supporting member and a feed port, a diversion channel, a diffusion channel, a buffer cavity, and a slit lip connected in sequence from top to bottom, wherein a plurality of diversion ports are separated from the end of the diversion channel to connect to the beginning of the diffusion channel, the diffusion channel is inclined downward, and a buffer column is arranged on the line connecting the beginning and the end of the buffer cavity; the widths of the diffusion channel, the buffer column and the buffer cavity are all equal to the coating width of the slit lip, and the supporting member includes a first support column arranged in the buffer column and a second support column arranged outside the buffer cavity.

[0008] The coating die head provided by the present application adopts a multi-cavity uniformity design. After the fluid enters the coating die head from one feed port, it is diverted to multiple diverter ports through the diverter channel. The fluid flows from multiple diverter ports to the diffusion channel, and gradually fills (fills in the width direction) the entire diffusion channel during the process of flowing obliquely downward to the buffer cavity, and then flows into the buffer cavity and pours on the buffer column, and then passes through the gap between the buffer column and the buffer cavity to reach the slit lip. The whole process makes greater use of gravity to make the fluid fill the internal space of the coating die head in the width direction, and the flow restriction of the fluid entering the cavity is reduced. After multiple buffering and deceleration, the fluid is more uniform before coating. The support member is used to connect the gantry or guide rail of the coating equipment, wherein the second support column is used to support the coating die head body, and the first support column independently supports the buffer column and assists in supporting the coating die head body, which not only avoids the weight of the buffer column dragging down the structurally weaker buffer cavity, but also reduces the pulling effect caused by the self-weight of the upper part of the coating die head to be transmitted to the buffer cavity, inhibits the deformation of the slit lip, and makes the fluid more uniform during coating.

[0009] Furthermore, the diffusion channel includes vertical flow sections and horizontal flow sections that are alternately connected, and the angle between the horizontal flow section and the horizontal plane is -30° to 0°.

[0010] The alternating vertical flow sections and horizontal flow sections make the diffusion channel form multiple steps. The step height causes the fluid to first accelerate down under the action of gravity, and then suddenly decelerate when it hits the bottom. The fluid that cannot continue to fall vertically diffuses to the left and right sides and the front (the adjacent horizontal flow section), which helps the fluid to fill the diffusion channel in the width direction faster.

[0011] Furthermore, a buffer groove is provided on the vertical flow section, and the radial cross-section of the buffer groove is circular, elliptical or inverted water drop-shaped.

[0012] The buffer groove can increase the velocity difference caused by the step drop on the fluid, and make the fluid that cannot continue to fall vertically spread more to the left and right sides, so that the uniformity of the fluid flowing here is rapidly improved.

[0013] Furthermore, there are two diffusion channels, and two groups of diversion ports are divided at the end of the diversion channel, one group of diversion ports corresponds to the starting end of one diffusion channel, the diversion channel itself and the buffer cavity itself use the first plane as the symmetry plane, the two diffusion channels use the first plane as the symmetry plane, the first plane is the vertical plane where the slit lip is located, and the ends of the two diffusion channels are connected to the buffer cavity.

[0014] After the fluid is distributed to the left and right diffusion channels, it reunites in the buffer chamber. For a single diffusion channel, halving the flow rate can slow down the flow velocity and improve the buffering effect of the fluid in the diffusion channel. In addition, the symmetrical design is more conducive to reducing the imbalance of weight ratio caused by uneven structural distribution and reducing the abnormal vibration problem of the gantry caused by inconsistent weight ratio.

[0015] Further, the ends of the two diffusion channels converge at a second gap, the second gap is connected to the beginning of the buffer cavity, the second gap is parallel to the slit lip, and the second gap is located on the first plane;

[0016] Alternatively, the ends of the two diffusion channels are independently connected to the buffer cavity to form two diffusion outlets, the two diffusion outlets are parallel to the slit lip, and the distance between the two diffusion outlets is less than two-thirds of the maximum inner diameter of the buffer cavity.

[0017] Furthermore, the radial cross-section of the buffer cavity is circular, elliptical or inverted teardrop-shaped, the buffer column is a cylinder with a curved surface, the geometric center of gravity of the buffer column is located on the first plane and is lower than the geometric center of gravity of the buffer cavity, and the minimum distance between the buffer column and the buffer cavity is greater than 0.5 times the width of the slit lip and less than 2 times the width of the slit lip, which is conducive to the fluid passing through the buffer column to flow smoothly out of the slit lip.

[0018] Furthermore, the second support column includes a central support column and two side support columns, the central support column is located within the enclosed range of the diversion channel, the two diffusion channels, and the buffer cavity, and the side support columns are located outside the enclosed range of the diversion channel, the two diffusion channels, and the buffer cavity, the central support column itself takes the first plane as the symmetry plane, and the two side support columns take the first plane as the symmetry plane.

[0019] Channels with more branches are conducive to uniform weight distribution of the coating die, but more branches weaken the cohesive force of the coating die. At this time, the main structure of the coating die is supported in two parts. Side support columns are used to stabilize the two sides of the coating die, and a central support column is used to support the part enclosed by the diversion channel, two diffusion channels, and the buffer chamber. This can reduce the deformation of the diffusion channel caused by the deadweight of the components and ensure that the volume of the two diffusion channels is consistent.

[0020] Furthermore, the height of the slit lip is greater than one-third of the maximum inner diameter of the buffer cavity and less than five times the maximum inner diameter of the buffer cavity, which is beneficial for the slit lip to be stable and not easily deformed in actual use, and reduces the impact of fluid fluctuations in the buffer cavity on discharging, making the discharging smoother.

[0021] Furthermore, a buffer ball is provided at the beginning of the diversion channel, which plays a first buffering role during feeding and helps the diversion channel to evenly distribute the fluid to each branch of the diversion channel.

[0022] In a second aspect, the present application provides a coating device, comprising the coating die head with uniform material discharge as described in the first aspect.

[0023] The beneficial effects of the present invention are: the coating die of the present invention adopts a multi-cavity uniformity design, which makes greater use of the effect of gravity to spread the fluid over the internal space of the coating die in the width direction, which is beneficial to relaxing the flow requirements for the fluid entering the cavity; the second support column is used to support the coating die body, and the first support column independently supports the buffer column and assists in supporting the coating die body, which is beneficial to suppressing the deformation of the slit lip caused by its own weight; the multi-cavity uniformity design and weight distribution design make the fluid more uniform before and during coating.

[0024] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures particularly pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is one of the internal structure schematic diagrams of a coating die head provided in an embodiment of the present application.

[0026] Figure 2 It is a three-dimensional schematic diagram of a coating die head provided in an embodiment of the present application.

[0027] Figure 3 A coating die head according to the embodiment of the present application Figure 2 Cross-sectional view after cutting through the mid-horizontal plane B.

[0028] Figure 4 This is a diagram of the internal structure of a coating die head provided in an embodiment of the present application.

[0029] Figure 5 yes Figure 4 Enlarged view of point A in the middle.

[0030] Figure 6 This is the second schematic diagram of the internal structure of a coating die head provided in an embodiment of the present application.

[0031] Figure 7 This is the third schematic diagram of the internal structure of a coating die head provided in an embodiment of the present application.

[0032] Figure numerals: 1. feed port; 2. diversion channel; 201. first double diversion channel; 202. second double diversion channel; 203. third double diversion channel; 204. fourth double diversion channel; 211. first corner channel; 212. second corner channel; 213. third corner channel; 28. diversion port; 29. ​​buffer ball; 3. diffusion channel; 31. vertical flow section; 311. buffer groove; 32. horizontal flow section; 37. diffusion outlet; 38. second gap; 39. first gap; 4. buffer cavity; 41. buffer column; 5. slit lip; 61. first support column; 62. central support column; 63. side support column. DETAILED DESCRIPTION

[0033] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0034] The disclosure below provides many different embodiments or examples to implement different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described below. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed.

[0035] In order to accurately and evenly coat the fluid, the shape of the coating die is mostly designed to be wide and large at the top (close to the feed port) and pointed and narrow at the bottom (close to the slit lip). In addition, a hemispherical, semi-cylindrical or semi-tear-shaped cavity is set inside the lower part, making the coating slit the weakest structural part of the entire coating die. The pulling caused by the weight of the coating die can easily cause the local gap width of the coating slit to change.

[0036] Reference Figures 1 to 4 ( Figure 1 Represents an instance structure. Figures 2 to 4 Represents an example structure), the present application provides a coating die head with uniform discharge, including a supporting member and a feed port 1, a diversion channel 2, a diffusion channel 3, a buffer cavity 4, and a slit lip 5 connected in sequence from top to bottom, a plurality of diversion ports 28 are separated from the end of the diversion channel 2 to connect to the beginning of the diffusion channel 3, the diffusion channel 3 is inclined downward, and a buffer column 41 is arranged on the line connecting the beginning and the end of the buffer cavity 4; the widths of the diffusion channel 3, the buffer column 41 and the buffer cavity 4 are all equal to the coating width of the slit lip 5, and the supporting member includes a first support column 61 arranged in the buffer column 41 and a second support column arranged outside the buffer cavity 4.

[0037] After the fluid enters the coating die head from the feed port 1, it is diverted to multiple diverter ports 28 through the diverter channel 2, and then gradually spreads and flattens the entire diffusion channel 3 while flowing obliquely downward in the diffusion channel 3, and then flows into the buffer chamber 4 and pours on the buffer column 41, and finally passes through the gap between the buffer column 41 and the buffer chamber 4 to reach the slit lip 5. The buffer column 41 is set on the necessary branch road from the beginning to the end of the buffer chamber 4. The fluid must first pour on the buffer column 41 and then flow downward along the surface of the buffer column 41 to prevent the fluid from falling directly from the beginning of the buffer column 41 and impacting the fluid to be coated, reduce the fluctuation of the fluid at the bottom of the buffer chamber 4, and make the flow of the fluid smoother during coating. The whole process makes greater use of gravity to make the fluid spread over the internal space of the coating die head (such as the diffusion channel 3, the surface of the buffer column 41, and the lower part of the buffer chamber 4) in the width direction (i.e. the width direction of the coating), which is conducive to reducing the dependence on the flow rate of the injected fluid. After multiple buffering and deceleration, the fluid is more uniform before coating.

[0038] The supporting member is used to connect the gantry or guide rail of the coating equipment, wherein the second supporting column is used to support the coating die body, and the first supporting column 61 independently supports the buffer column 41 and auxiliary supports the coating die body, which can not only avoid the weight of the buffer column 41 from dragging down the structurally weaker buffer cavity 4, but also reduce the pulling effect caused by the self-weight of the upper part of the coating die from being transmitted to the buffer cavity 4, inhibit the deformation of the slit lip 5, and make the fluid more uniform during coating.

[0039] Figure 1 In the embodiment of the single-sided buffer structure, the radial cross-section of the buffer cavity 4 is semicircular, semi-elliptical or semi-inverted water drop, and the buffer column 41 is a semi-cylindrical body, a semi-water drop column, etc. The buffer column 41 can be made into an integral structure with the lip on one side, such as Figure 1 shown.

[0040] In a preferred embodiment, reference Figures 2 to 7 ( Figure 4 The supporting structure is omitted in the figure), and the coating die head has a double-sided buffer structure.

[0041] There are two diffusion channels 3, and two groups of diversion ports 28 are separated at the end of the diversion channel 2. One group of diversion ports 28 is connected to the beginning of one diffusion channel 3. The diversion channel 2 itself and the buffer cavity 4 itself are symmetrical with the first plane. The two diffusion channels 3 are symmetrical with the first plane. The first plane is the vertical plane where the slit lip 5 is located (such as Figure 2 The ends of the two diffusion channels 3 are connected to the buffer chamber 4.

[0042] After the fluid is distributed to the left and right diffusion channels 3, it reunites in the buffer chamber 4. For a single diffusion channel 3, halving the flow rate can slow down the flow rate and improve the buffering effect of the fluid in the diffusion channel 3. In addition, the symmetrical design is more conducive to reducing the abnormal vibration problem of the gantry caused by inconsistent weight ratio.

[0043] Reference Figure 1 , Figure 3 , Figure 6 and Figure 7 A buffer ball 29 may be provided at the beginning of the diversion channel 2, so that the fluid flowing from the feed port 1 to the diversion channel 2, the diffusion channel 3, and the buffer cavity 4 can all receive buffering treatment. In the embodiment where the coating die head is symmetrical about the first plane, the buffer ball 29 also has the function of assisting in evenly distributing the fluid to both sides of the first plane.

[0044] The coating die head can also have a second plane as a symmetry plane, and the second plane is a vertical plane passing through the axis of the feed port 1 and perpendicular to the first plane (such as Figure 2 The entire coating die head is symmetrical about two mutually orthogonal planes, and the weight distribution of the internal structure of the coating die head is more balanced, which is conducive to improving the stability of the coating in motion.

[0045] To achieve this symmetry between two vertical planes, please refer to Figure 3 and Figure 4 , the flow channel 2 includes multiple two-divided flow channels, the flow outlet 28 is connected to the end of the last two-divided flow channel, and the beginning of the diffusion channel 3 is the first slit 39 parallel to the slit lip 5. The fluid passes through the two-divided flow channels of one-divided-two, two-divided-four, four-divided-eight, and eight-divided-sixteen, and enters the two groups of flow outlets 28 synchronously in a diverted manner. The queue of the same group of flow outlets 28 is parallel to the slit lip 5, and the two groups of flow outlets 28 flow to the first slits 39 at the beginning of the two diffusion channels 3 at the same time, which not only completes the flow diversion buffer, but also makes the weight distribution inside the coating die head balanced.

[0046] More preferably, the two-branch flow channel is parallel to the slit lip 5, and a corner flow channel perpendicular to the two-branch flow channel is connected between the front and rear (in the order of fluid flow, the first position reached is the front), and the flow directions of the front and rear corner flow channels are opposite (referring to the opposite directions in three-dimensional space, and in fact the fluid does not flow back).

[0047] Specifically, after the fluid enters the coating die head from the feed port 1, it is poured onto the buffer ball 29 and is divided to the midpoint of the first double-branch channel 201 on both sides. The two ends of the first double-branch channel 201 are respectively connected to a first double corner channel 211 to make the fluid turn 90 degrees. The end of the first double corner channel 211 is connected to the midpoint of the second double-branch channel 202. The two ends of the second double-branch channel 202 are respectively connected to a second double corner channel 212 to make the fluid turn 90 degrees. The direction of the first corner channel 211 is opposite, the end of the second corner channel 212 is connected to the midpoint of the third double-branch channel 203, and the two ends of the third double-branch channel 203 are each connected to a third corner channel 213 to make the fluid turn 90°. After the turn, the direction is opposite to the second corner channel 212, and the end of the third corner channel 213 is connected to the midpoint of the fourth double-branch channel 204. The two ends of the fourth double-branch channel 204 are each connected to a branch port 28.

[0048] The inner diameter of the second double-branch channel is smaller than that of the first double-branch channel, and the flow rate of the second double-branch channel is 40% to 60% of that of the first double-branch channel, and the specifications of the same double-branch channel are the same; the inner diameter of the second corner channel is smaller than that of the first corner channel, and the flow rate of the second corner channel is 40% to 60% of that of the first corner channel, and the specifications of the same corner channel are the same. This structure can divide as many branch ports 28 as possible in a limited space, and densely distribute branches in the coating die head, so that the coating die head can be in a state of balanced internal weight distribution regardless of whether there is fluid flowing in.

[0049] Specifically, the angle between the corner flow channel and the horizontal plane can be -90°~0°.

[0050] After two diffusion channels 3 are provided, there are two ways of connecting the diffusion channels 3 and the buffer chamber 4 .

[0051] The first one, refer to Figure 6 The ends of the two diffusion channels 3 converge at the second slit 38, the second slit 38 connects to the beginning of the buffer cavity 4, the second slit 38 is parallel to the slit lip 5, and the second slit 38 is located on the first plane. Figure 5 The cross section above the starting end of the buffer cavity 4 is Y-shaped, which brings together the symmetrical diffusion channels 3 and then flows into the buffer cavity 4.

[0052] The second one, refer to Figure 7 The ends of the two diffusion channels 3 are independently connected to the buffer chamber 4 to form two diffusion outlets 37 . The two diffusion outlets 37 are parallel to the slit lip 5 , and the distance between the two diffusion outlets 37 is less than two-thirds of the maximum inner diameter of the buffer chamber 4 .

[0053] The radial cross-section of the buffer cavity 4 is circular, elliptical or inverted teardrop-shaped, and the buffer column 41 is a column with an arc surface, such as a cylinder, an elliptical column, etc. The geometric center of gravity of the buffer column 41 is located on the first plane and is lower than the geometric center of gravity of the buffer cavity 4, that is, the buffer column 41 is located at a lower position in the buffer cavity 4, and the minimum distance between the buffer column 41 and the buffer cavity 4 is greater than 0.5 times the width of the slit lip 5 and less than 2 times the width of the slit lip 5, which is conducive to smooth discharge of the fluid. Preferably, the minimum distance between the buffer column 41 and the buffer cavity 4 is less than the width of the slit lip 5.

[0054] Specifically, the slit width is less than 100 um and greater than 2 um.

[0055] In some embodiments, Figure 6 As shown, the diffusion channel 3 may include a wavy channel, and it should be noted that there should be no upward segments along the entire wavy line.

[0056] In other embodiments, reference Figure 1 and Figure 7 The diffusion channel 3 includes vertical flow sections 31 and horizontal flow sections 32 which are alternately connected, and the angle between the horizontal flow section 32 and the horizontal plane is -30° to 0°.

[0057] The alternating vertical flow sections 31 and horizontal flow sections 32 make the diffusion channel 3 form multiple steps. The step height makes the fluid first accelerate down under the action of gravity, and then suddenly decelerate when it hits the bottom (the next horizontal flow section). The fluid that cannot continue to fall vertically diffuses to the left and right sides and the front, which is conducive to the fluid spreading across the diffusion channel 3 in the width direction faster.

[0058] Preferably, refer to Figure 7 The vertical flow section 31 is provided with a buffer groove 311, and the radial cross-section of the buffer groove 311 is in the shape of an inverted water drop. The shape is similar to the buffer cavity, but the working principle is slightly different. The buffer cavity 4 is equipped with a buffer column 41 to play a buffering role, and the buffer groove 311 can increase the speed difference caused by the step drop to the fluid, so that the fluid that cannot continue to fall vertically spreads more to the left and right sides, and less directly spreads forward.

[0059] The fluid can flow from the diffusion channel 3 into the buffer chamber 4 from above or from the side, with an angle of -90° to 0°. Figure 6 The embodiment shown is -90°, Figure 1 The embodiment shown is 0°, Figure 7 The embodiment shown is 44°.

[0060] In the embodiment where the coating die is symmetrical about the first plane or the coating die is symmetrical about two vertical planes, more branch channels are beneficial to uniform weight distribution of the coating die, but more branches cause the cohesive force of the coating die to be weakened.

[0061] Correspondingly, the second support column includes a central support column 62 and two side support columns 63. The central support column 62 is located within the enclosed range of the diversion channel 2, the two diffusion channels 3, and the buffer cavity 4, and the side support column 63 is located outside the enclosed range of the diversion channel 2, the two diffusion channels 3, and the buffer cavity 4. The central support column 62 itself takes the first plane as the symmetry plane, and the two side support columns 63 take the first plane as the symmetry plane.

[0062] At this time, the main structure of the coating die is supported in two parts. The side support columns 63 are used to stabilize the two sides of the coating die, and the central support column 62 is used to support the part enclosed by the diversion channel 2, the two diffusion channels 3, and the buffer chamber 4. In addition, the auxiliary support effect of the first support column 61 on the main body of the coating die can reduce the deformation of the diffusion channel 3 caused by the self-weight of the components, ensuring that the volume of the two diffusion channels 3 is consistent.

[0063] In some embodiments, an electric heating device may be provided in the buffer column 41 to heat the fluid.

[0064] The embodiment of the present application also provides a coating device, including the above-mentioned coating die head with uniform material discharge, for example, including a guide rail or a gantry for docking a support member, and the support member can be a through-type or embedded type.

[0065] The present invention proposes a coating die head and coating equipment with a buffer structure, which are mainly used to solve the problems of uneven weight ratio and uneven coating of the coating die head and enhance the stability of the coating head during the coating process. A diffusion channel 3 is added inside the coating head, and the diversion channel 2 and the buffer chamber 4 are improved to ensure that the fluid reaches the outlet slit evenly and improve the coating uniformity.

[0066] In the description of this specification, the description with reference to the terms "one embodiment", "certain embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0067] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. A coating die head with uniform discharge, characterized in that: The invention comprises a support member for connecting a gantry or a guide rail of a coating device, and a feed port (1), a flow diversion channel (2), a diffusion channel (3), a buffer cavity (4), and a slit lip (5) which are connected in sequence from top to bottom, wherein a plurality of flow diversion ports (28) are separated from the end of the flow diversion channel (2) and connected to the beginning of the diffusion channel (3), the diffusion channel (3) is inclined downward, and a buffer column (41) is arranged on the line connecting the beginning and the end of the buffer cavity (4); the widths of the diffusion channel (3), the buffer column (41), and the buffer cavity (4) are all equal to the coating width of the slit lip (5), and the support member comprises a first support column (61) arranged in the buffer column (41) and a second support column arranged outside the buffer cavity (4); There are two diffusion channels (3), two groups of diversion ports (28) are formed at the end of the diversion channel (2), one group of diversion ports (28) is connected to the start end of one diffusion channel (3), the diversion channel (2) and the buffer chamber (4) are symmetrical with the first plane, the two diffusion channels (3) are symmetrical with the first plane, the first plane is the vertical plane where the slit lip (5) is located, and the ends of the two diffusion channels (3) are connected with the buffer chamber (4); The ends of the two diffusion channels (3) converge at a second slit (38), the second slit (38) is connected to the beginning of the buffer cavity (4), the second slit (38) is parallel to the slit lip (5), and the second slit (38) is located on the first plane; Alternatively, the ends of the two diffusion channels (3) are independently connected to the buffer chamber (4) to form two diffusion outlets (37), the two diffusion outlets (37) are parallel to the slit lip (5), and the distance between the two diffusion outlets (37) is less than two thirds of the maximum inner diameter of the buffer chamber (4).

2. The coating die head with uniform discharge according to claim 1, characterized in that: The diffusion channel (3) comprises vertical flow sections (31) and horizontal flow sections (32) which are alternately connected, and the angle between the horizontal flow section (32) and the horizontal plane is between -30° and 0°.

3. The coating die head with uniform discharge according to claim 2, characterized in that: The vertical flow section (31) is provided with a buffer groove (311), and the radial cross-sectional shape of the buffer groove (311) is circular, elliptical or inverted water drop shape.

4. The coating die head with uniform discharge according to claim 1, characterized in that: The radial cross-section of the buffer cavity (4) is circular, elliptical or inverted teardrop-shaped, the buffer column (41) is a column with a curved surface, the geometric center of gravity of the buffer column (41) is located on the first plane and is lower than the geometric center of gravity of the buffer cavity (4), and the minimum distance between the buffer column (41) and the buffer cavity (4) is greater than 0.5 times the width of the slit lip (5) and less than 2 times the width of the slit lip (5).

5. The coating die head with uniform discharge according to claim 1, characterized in that: The second support column comprises a central support column (62) and two side support columns (63); the central support column (62) is located within the enclosed range of the diverter channel (2), the two diffusion channels (3) and the buffer chamber (4); the side support columns (63) are located outside the enclosed range of the diverter channel (2), the two diffusion channels (3) and the buffer chamber (4); the central support column (62) itself takes the first plane as a symmetry plane, and the two side support columns (63) take the first plane as a symmetry plane.

6. The coating die head with uniform discharge according to claim 1, characterized in that: The height of the slit lip (5) is greater than one third of the maximum inner diameter of the buffer cavity (4) and less than five times the maximum inner diameter of the buffer cavity (4).

7. The coating die head with uniform discharge according to claim 1, characterized in that: A buffer ball (29) is provided at the beginning of the diversion channel (2).

8. A coating device, characterized in that: A coating die head with uniform discharge comprising the coating die head according to any one of claims 1 to 7.

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