Micro-droplet ejecting unit and micro-droplet ejecting apparatus

Abstract

The invention discloses a micro-droplet jetting unit and a corresponding micro-droplet jetting device. A pressure cavity, a liquid inlet channel and a liquid outlet channel are formed in a pressure cavity substrate layer of the micro-droplet spraying unit, a liquid inlet and a liquid outlet are formed in the packaging protection layer, and the liquid inlet channel located at the liquid inlet end and the liquid outlet channel located at the liquid outlet end are connected with the side face of the pressure cavity in an open shape. Wherein the liquid inlet channel, the liquid outlet channel and the pressure cavity, the liquid inlet and the liquid inlet channel, and the liquid outlet and the liquid outlet channel respectively extend and are connected with one another in the direction with a certain angle, so that the printing ink liquid has multiple turns in the flowing direction in the circulating flowing process. According to the invention, the problem of crosstalk caused by conduction of pressure waves through liquid flowing can be reduced, meanwhile, the flowing resistance of the ink liquid is greatly reduced, the flowing of the ink liquid with high viscosity or high solid content (high granularity) is particularly facilitated, and the spraying frequency can be improved, so that the working efficiency of a device is improved.

Description

Technical Field

[0001] The invention relates to the technical field of inkjet printing equipment, and in particular to a micro-droplet ejection unit and a micro-droplet ejection device. Background Art

[0002] With the development of diversified functional materials for inkjet printing, piezoelectric inkjet print heads have become the mainstream technology for scientific research and industrial inkjet printing due to the wide range of liquid types that can be sprayed. The working principle of the piezoelectric nozzle is to selectively apply a driving voltage signal to the piezoelectric element of the nozzle according to the preset printing image. Due to the inverse piezoelectric effect of the piezoelectric material, the piezoelectric element bends and deforms after being stimulated by the electrical signal, squeezing the liquid in the pressure chamber of the nozzle, thereby causing the liquid near the nozzle to be ejected from the nozzle to form the required droplets. With the application of MEMS piezoelectric film in circulating hydraulic electric nozzles, the characteristics of batch manufacturing of MEMS processing technology have reduced the manufacturing cost of circulating hydraulic electric nozzles, thereby further promoting the application of piezoelectric nozzles in functional material printing.

[0003] Chinese patent application (application number: CN201680045218.6, hereinafter referred to as "prior art 1") discloses an inkjet print head. Figure 1 and Figure 2 The inkjet print head mold includes a plurality of droplet units arranged in an array thereon, and the droplet unit includes a nozzle layer, a fluid chamber substrate, a vibration plate and an actuator arranged in sequence. The droplet unit includes a fluid chamber and a fluid inlet port connected to the fluid of the fluid chamber via a fluid supply channel, and also includes a fluid outlet port connected to the fluid of the fluid chamber via a fluid return channel. The nozzle layer is provided with a nozzle connected to the fluid chamber. When the actuator receives a driving waveform signal and generates stress to cause the vibration plate to deform, the vibration plate squeezes the liquid in the fluid chamber, and at this time, the liquid near the nozzle is subjected to an instantaneous thrust and rushes out of the nozzle to form a droplet.

[0004] It will be understood by those skilled in the art that when the vibration plate of a certain droplet unit squeezes the liquid in the fluid chamber to spray droplets, the pressure wave provided by the vibration plate will be transmitted to the circulating liquid pool through the liquid flow, which will adversely affect the liquid supply stability of the circulating liquid pool, and further interfere with the spraying work of other droplet units. In response to the above problems, the existing common solution is: narrow channels with smaller cross-sectional areas are respectively provided at both ends of the fluid chamber, and the liquid flow direction in the narrow channels is the same as the liquid flow direction in the fluid chamber, and the conduction of the pressure wave through the liquid flow is eliminated through the narrow channels. For example, in the scheme of prior art 1, the liquid flow directions of the fluid inlet port and the fluid supply channel are the same, the fluid supply channel and the fluid chamber are provided with a narrow fluid channel, the liquid flow directions of the fluid outlet port and the fluid return channel are the same, and the fluid return channel and the fluid chamber are provided with another narrow fluid channel. Refer to prior art 1. Figure 1 and Figure 2 , relative to the fluid chamber, the height and width of the fluid channel therein are smaller, that is, it is formed into a narrow and long channel with a small cross-sectional area.

[0005] Although the above solution can greatly reduce the problem of crosstalk caused by pressure waves transmitted through liquid flow, such a solution will bring the following problems: the narrow channels connected at both ends of the fluid chamber will cause the flow resistance of high-viscosity or high-solid content (high-particle size) ink liquid to increase, resulting in a decrease in the liquid supply flow rate of the nozzle, affecting the injection frequency and reducing work efficiency. Summary of the invention

[0006] In view of this, the present invention provides a micro-droplet ejection unit and a micro-droplet ejection device to solve the problem of how to reduce the crosstalk caused by the pressure wave transmitted through the liquid flow while avoiding increasing the flow resistance of the ink liquid, so as to achieve the ejection of high viscosity or high solid content (high particle size) liquid.

[0007] In order to solve the above problems, one aspect of the present invention is to provide a micro-droplet ejection unit, comprising a nozzle layer, a pressure chamber base layer, a deformable partition, a piezoelectric actuator and a packaging protection layer arranged in sequence, the pressure chamber base layer is provided with a pressure chamber, a first liquid inlet channel and a first liquid outlet channel, the pressure chamber extends along a first direction, the first liquid inlet channel extends along a second direction, the first liquid outlet channel extends along a third direction, the first end of the first liquid inlet channel is openly connected to the side of the first end of the pressure chamber, the first end of the first liquid outlet channel is openly connected to the side of the second end of the pressure chamber, and the nozzle layer is provided with a nozzle connected to the pressure chamber;

[0008] A liquid inlet and a liquid outlet are provided in the encapsulation protection layer, the liquid inlet extends along a fourth direction and is connected to the second end of the first liquid inlet channel, and the liquid outlet extends along a fifth direction and is connected to the second end of the first liquid outlet channel;

[0009] Among them, with the XYZ three-dimensional coordinate system as a reference, the first direction, the second direction and the third direction are located in the XY plane, the second direction and the first direction have an angle α1, the third direction and the first direction have an angle β1, the fourth direction and the Z axis have an angle θ1 of 0° to 30°, and the fifth direction and the Z axis have an angle θ2 of 0° to 30°.

[0010] Preferably, the angle α1 is 60° to 120°, and the angle β1 is 60° to 120°.

[0011] Preferably, the angle α1 is 85° to 95°, the angle β1 is 85° to 95°, the angle θ1 is 0° to 5°, and the angle θ2 is 0° to 5°.

[0012] Preferably, the angle α1 and the angle β1 have the same angle value, and the angle θ1 and the angle θ2 have the same angle value.

[0013] Preferably, the side surface where the first end of the first liquid inlet channel communicates with the pressure chamber and the side surface where the first end of the first liquid outlet channel communicates with the pressure chamber are two opposite side surfaces.

[0014] Preferably, the pressure chamber has a width D perpendicular to the first direction, the first liquid inlet channel has a length L1 along the second direction, the first liquid outlet channel has a length L2 along the third direction, the length L1 is 0.5 to 2 times the width D, and the length L2 is 0.5 to 2 times the width D.

[0015] Preferably, the length L1 and the length L2 have the same length value.

[0016] Preferably, a second liquid inlet channel and a second liquid outlet channel are also provided in the base layer of the pressure chamber, the second liquid inlet channel extends along a sixth direction, the second liquid outlet channel extends along a seventh direction, the sixth direction and the seventh direction are located in the XY plane, an angle α2 is formed between the sixth direction and the second direction, and an angle β2 is formed between the seventh direction and the third direction; a first end of the second liquid inlet channel is connected to a second end of the first liquid inlet channel, the liquid inlet port is connected to a second end of the second liquid inlet channel, a first end of the second liquid outlet channel is connected to a second end of the first liquid outlet channel, and the liquid outlet port is connected to a second end of the second liquid outlet channel.

[0017] In order to solve the above problems, another aspect of the present invention is to provide a micro-droplet ejecting device, which includes the micro-droplet ejecting unit as described above.

[0018] Furthermore, the micro-droplet ejection device comprises a plurality of the micro-droplet ejection units arranged in an array of M rows × N columns, where M is an integer greater than 1, and N is an integer greater than 1; wherein a first direction in which the length of the pressure chamber in the micro-droplet ejection unit extends is obliquely intersected with a row direction of the array arrangement.

[0019] The micro-droplet injection unit and the micro-droplet injection device provided by the embodiments of the present invention have a liquid inlet channel located at the liquid inlet end that is openly connected to the side of the pressure chamber, and a liquid outlet channel located at the liquid outlet end that is also openly connected to the side of the pressure chamber, and there are no narrow and long channels on the fluid channels at the liquid inlet end and the liquid outlet end of the pressure chamber, thereby greatly reducing the flow resistance of the ink liquid, which is particularly beneficial to the flow of ink liquid with high viscosity or high solid content (high particle size), and can increase the injection frequency and thus improve the working efficiency of the device; on the other hand, by improving the extension direction of the fluid channels of various parts of the liquid inlet end and the liquid outlet end, the ink liquid has multiple flow direction turns during the circulation process, absorbing the pressure waves that flow with the liquid when the droplets are injected, and avoiding the pressure waves from being transmitted to the circulating liquid pool and causing crosstalk to other micro-droplet injection units. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a top view of a micro-droplet ejection unit in an embodiment of the present invention;

[0021] Figure 2 is along Figure 1 The cross-section of the middle dashed line AA;

[0022] Figure 3 is along Figure 1 The cross-section of the middle dashed line BB;

[0023] Figure 4 is a top view of a micro-droplet ejection unit in another embodiment of the present invention;

[0024] Figure 5 Schematic diagram of the structure of the micro-droplet ejection device in the embodiment of the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical scheme and advantages of the present invention clearer, the specific embodiments of the present invention are described in detail below in conjunction with the accompanying drawings. Examples of these preferred embodiments are illustrated in the accompanying drawings. The embodiments of the present invention shown in the accompanying drawings and described according to the accompanying drawings are merely exemplary, and the present invention is not limited to these embodiments.

[0026] It should also be noted that, in order to avoid obscuring the present invention due to unnecessary details, only structures and / or processing steps closely related to the solutions according to the present invention are shown in the accompanying drawings, while other details that are not closely related to the present invention are omitted.

[0027] The embodiment of the present invention first provides a micro-droplet ejection unit, referring to Figures 1 to 3 The micro-droplet ejection unit 100 includes a nozzle layer 1, a pressure chamber base layer 2, a deformable diaphragm 3, a piezoelectric actuator 4 and a packaging protection layer 5 which are arranged in sequence.

[0028] The pressure chamber base layer 2 is provided with a pressure chamber 21, a first liquid inlet channel 22 and a first liquid outlet channel 23. The nozzle layer 1 is located relatively below the pressure chamber base layer 2, and a nozzle 11 connected to the pressure chamber 21 is provided in the nozzle layer 1. The deformable diaphragm 3 is located relatively above the pressure chamber base layer 2, and the deformable diaphragm 3, the nozzle layer 1 and the pressure chamber base layer 2 jointly surround and seal the various cavities provided in the pressure chamber base layer 2, such as the pressure chamber 21, the first liquid inlet channel 22 and the first liquid outlet channel 23. The piezoelectric actuator 4 is arranged on the deformable diaphragm 3 and is located above the pressure chamber 21. The packaging protective layer 5 is covered on the piezoelectric actuator 4, and a liquid inlet 51 and a liquid outlet 52 are provided in the packaging protective layer 5.

[0029] The liquid inlet 51 is connected to the pressure chamber 21 through the first liquid inlet channel 22, and the liquid outlet 52 is connected to the pressure chamber 21 through the first liquid outlet channel 23. The liquid inlet 51 is also connected to an external circulating liquid pool through an external positive pressure pump, and the liquid outlet 52 is also connected to an external circulating liquid pool through an external negative pressure pump. The ink liquid in the circulating liquid pool enters from the liquid inlet 51 under the push of the external positive pressure pump, passes through the first liquid inlet channel 22 and enters the pressure chamber 21; the ink liquid in the pressure chamber 21 passes through the first liquid outlet channel 23 and returns to the external circulating liquid pool via the liquid outlet 52 under the push of the external negative pressure pump, forming a continuous liquid circulation flow.

[0030] When the micro-droplet ejection unit 100 is performing ejection operation, the piezoelectric brake 4 receives the driving waveform signal to generate stress to cause the deformable diaphragm 3 to deform. The deformable diaphragm 3 squeezes the ink liquid in the pressure chamber 21, and the ink liquid near the nozzle 11 is subjected to instantaneous thrust to rush out of the nozzle to form ejected droplets.

[0031] The nozzle layer 1 can be made of silicon or glass or metal such as Ni, stainless steel or other non-deformable and corrosion-resistant materials, and the thickness is preferably 10 μm to 100 μm. The nozzle 11 penetrating the nozzle layer 1 is preferably a circular opening, and the opening diameter of the nozzle 11 is preferably 10 μm to 100 μm. The nozzle shape can be obtained by photolithography combined with etching or electroplating processing technology, or by laser drilling and other processing technologies.

[0032] As a preferred solution, in this embodiment, the nozzle 11 is arranged at a position corresponding to the exact center of the pressure chamber 21 .

[0033] The pressure chamber base layer 2 can be made of silicon or glass or metal such as Ni, stainless steel, etc., which are not easily deformed and corrosion-resistant materials, and the thickness is preferably 10 μm to 100 μm. Each cavity in the pressure chamber base layer 2, such as the pressure chamber 21, the first liquid inlet channel 22, and the first liquid outlet channel 23, can be prepared by photolithography combined with etching or electroplating processing technology.

[0034] The deformable partition 3 may be made of a deformable thin film material, and the specific material may be metal, alloy, dielectric material, semiconductor material or polyimide, etc.

[0035] The piezoelectric brake 4 includes a lower electrode 41, a piezoelectric element 42 and an upper electrode 43 which are sequentially arranged on the deformable diaphragm 3. Specifically, a lower metal film, such as Ti / Pt, Ti / Ir, etc., can be deposited on the deformable diaphragm 3, and a piezoelectric film, such as a PZT film, can be further deposited on the lower metal film, and then an upper metal film, such as Pt, Ir, etc., can be further deposited, and a piezoelectric actuator 4 including a structure of a lower electrode 41, a piezoelectric element 42 and an upper electrode 43 can be formed by photolithography and etching. Further, a passivation layer film, such as SiO2, SiN or a combination of the two, is deposited to form a passivation layer 44 to separate the lower electrode 41 and the upper electrode 43 to avoid short circuits during subsequent processing. The passivation layer 44 is photolithographically and etched to open openings for the lower electrode 41 and the upper electrode 43 to be electrically connected to the outside world, and a lower electrode lead 45 and an upper electrode lead 46 electrically connected to the outside world are formed at the openings by thin film deposition and etching.

[0036] Further, as a preferred solution, the piezoelectric element 42 is in a rectangular structure and is disposed along the length direction of the pressure chamber 21 .

[0037] The packaging protection layer 5 is mainly used to separate the piezoelectric actuator 4 from liquids such as ink, and protect the piezoelectric actuator 4 from external pollution or damage by external forces, etc. The packaging protection layer 5 is formed into a desired structure by etching a suitable material such as silicon or glass.

[0038] In the embodiment of the present invention, refer to Figures 1 to 3, the pressure chamber 21 extends along the first direction, the first liquid inlet channel 22 extends along the second direction, the first liquid outlet channel 23 extends along the third direction, the first end of the first liquid inlet channel 22 is in open communication with the side of the first end of the pressure chamber 21, and the first end of the first liquid outlet channel 23 is in open communication with the side of the second end of the pressure chamber 21. It should be noted that the first end of the first liquid inlet channel 22 is in open communication with the side of the pressure chamber 21, that is, the end surface of the first end of the first liquid inlet channel 22 is completely open, which can be understood as the size and shape of the connection interface being the same as the cross-section of the first liquid inlet channel 22. Similarly, the first end of the first liquid outlet channel 23 is in open communication with the side of the pressure chamber 21, which is also understood in the same way as above. Further, the liquid inlet 51 extends along the fourth direction and is connected to the second end of the first liquid inlet channel 22, and the liquid outlet 52 extends along the fifth direction and is connected to the second end of the first liquid outlet channel 23.

[0039] Among them, the first liquid inlet channel 22, the first liquid outlet channel 23 and the pressure chamber 21, the liquid inlet port 51 and the first liquid inlet channel 22, and the liquid outlet port 52 and the first liquid outlet channel 23 are extended and connected to each other in directions at a certain angle, so that the ink liquid has multiple flow direction turns during the circulation process.

[0040] Specifically, with the XYZ three-dimensional coordinate system as a reference, the first direction, the second direction and the third direction as described above are located in the XY plane. An angle α1 is provided between the second direction and the first direction, an angle β1 is provided between the third direction and the first direction, an angle θ1 between the fourth direction and the Z axis is 0° to 30°, and an angle θ2 between the fifth direction and the Z axis is 0° to 30°. Further, the angle α1 is preferably 60° to 120°. The angle β1 is preferably 60° to 120°.

[0041] As a preferred solution, the angle α1 and the angle β1 have the same angle value, and the angle θ1 and the angle θ2 have the same angle value.

[0042] The angle α1 is further preferably 85° to 95°, the angle β1 is further preferably 85° to 95°, the angle θ1 is further preferably 0° to 5°, and the angle θ2 is further preferably 0° to 5°. That is, the second direction is perpendicular to the first direction or nearly perpendicular to each other, the third direction is perpendicular to the first direction or nearly perpendicular to each other, and the fourth direction and the fifth direction are perpendicular to the XY plane or nearly perpendicular to the XY plane, respectively.

[0043] The most preferred solution is Figure 1 As shown, the second direction and the third direction are perpendicular to the first direction, and the fourth direction and the fifth direction are perpendicular to the XY plane, that is, in the XYZ three-dimensional coordinate system, the first direction is in the X-axis direction, the second direction and the third direction are in the Y-axis direction, and the fourth direction and the fifth direction are in the Z-axis direction. That is, the first liquid inlet channel 22 and the first liquid outlet channel 23 are connected to the pressure chamber 21 perpendicularly, the liquid inlet 51 and the first liquid inlet channel 22 are connected perpendicularly, and the liquid outlet 52 and the first liquid outlet channel 23 are connected perpendicularly, and the ink liquid has multiple 90° turns in the flow direction during the circulation process. It should be noted that Figures 1 to 3 In the symbol The symbol “⊙” indicates that the ink liquid flows in the direction of the arrow in the viewing plane, and the symbol “∘” indicates that the ink liquid flows inward in a direction perpendicular to the viewing plane. The ink liquid is shown flowing outward in a direction perpendicular to the viewing plane.

[0044] In the embodiment of the present invention, Figure 1 As shown, the side where the first end of the first liquid inlet channel 22 communicates with the pressure chamber 21 and the side where the first end of the first liquid outlet channel 23 communicates with the pressure chamber 21 are two opposite sides.

[0045] Further, see Figure 2 , the pressure chamber has a width D perpendicular to the first direction, the first liquid inlet channel has a length L1 along the second direction, and the first liquid outlet channel has a length L2 along the third direction (not shown in the drawings). The length L1 is preferably 0.5 to 2 times the width D, and the length L2 is preferably 0.5 to 2 times the width D. Further, the length L1 and the length L2 are preferably set to have the same length value.

[0046] In the micro-droplet ejection unit described in the above embodiment, the liquid inlet channel located at the liquid inlet end is openly connected to the side of the pressure chamber, and the liquid outlet channel located at the liquid outlet end is also openly connected to the side of the pressure chamber, and there are no narrow and long channels on the fluid channels at the liquid inlet end and the liquid outlet end of the pressure chamber, thereby greatly reducing the flow resistance of the ink liquid, which is particularly beneficial to the flow of ink liquid with high viscosity or high solid content (high particle size), and can increase the ejection frequency and thus improve the working efficiency of the device; on the other hand, by improving the extension direction of the fluid channels of various parts of the liquid inlet end and the liquid outlet end, the ink liquid has multiple flow direction turns during the circulation process, absorbing the pressure waves that flow with the liquid when ejecting droplets, and avoiding the pressure waves from being transmitted to the circulating liquid pool and causing crosstalk to other micro-droplet ejection units.

[0047] In some other embodiments of the micro-droplet ejection unit 100, in order to further eliminate the conduction of the pressure wave with the flow of the liquid, refer to Figure 4 , a second liquid inlet channel 24 and a second liquid outlet channel 25 may also be provided in the pressure chamber base layer, the second liquid inlet channel 24 extends along the sixth direction, the second liquid outlet channel 25 extends along the seventh direction, the sixth direction and the seventh direction are located in the XY plane, the sixth direction and the second direction have an angle α2, and the seventh direction and the third direction have an angle β2; the first end of the second liquid inlet channel 24 is connected to the second end of the first liquid inlet channel 22, the liquid inlet 51 is connected to the second end of the second liquid inlet channel 24, the first end of the second liquid outlet channel 25 is connected to the second end of the first liquid outlet channel 23, and the liquid outlet 52 is connected to the second end of the second liquid outlet channel 25. That is, the second liquid inlet channel 24 is additionally provided between the liquid inlet 51 and the first liquid inlet channel 22, and the second liquid outlet channel 25 is additionally provided between the liquid outlet 52 and the first liquid outlet channel 23, thereby increasing the number of turning times of the flow direction of the ink liquid during the circulation process, and further eliminating the conduction of the pressure wave with the liquid flow.

[0048] Among them, the angle α2 can be set to 60°~120°, further preferably 85°~95°, and most preferably 90°, that is, the second liquid inlet channel 24 and the first liquid inlet channel 22 are connected to each other vertically; the angle β2 can be set to 60°~120°, further preferably 85°~95°, and most preferably 90°, that is, the second liquid outlet channel 25 and the first liquid outlet channel 23 are connected to each other vertically.

[0049] The second liquid inlet channel 24 has a length L3 along the sixth direction, and the second liquid outlet channel 25 has a length L4 along the seventh direction. The length L3 is preferably 0.5 to 2 times the length L1, and the length L4 is preferably 0.5 to 2 times the length L2.

[0050] Based on the micro-droplet ejection unit 100 provided in the above embodiment, the present invention further provides a micro-droplet ejection device, see Figure 5 The micro-droplet ejection device comprises a plurality of micro-droplet ejection units 100 arranged in an array of M rows × N columns, where M is an integer greater than 1 and N is an integer greater than 1. The first direction in which the length of the pressure chamber 21 in the micro-droplet ejection unit 100 extends is obliquely intersected with the row direction of the array arrangement. All micro-droplet ejection units 100 in the same row are inclined in the same direction, and the inclination directions of the micro-droplet ejection units 100 in different rows may be the same or different.

[0051] Specifically, Figure 5 , the micro-droplet ejection device of this embodiment includes 2 rows of the micro-droplet ejection units 100, each row includes a plurality of micro-droplet ejection units 100 arranged in parallel and tilted, and the array of micro-droplet ejection units 100 is tilted at a certain angle, which can increase the number of arrangements.

[0052] In the example of the row direction of the array arrangement from left to right in the figure, all the micro-droplet ejection units 100 in the first row are tilted to the right, and all the micro-droplet ejection units 100 in the second row are tilted to the left. The nozzles of the two adjacent rows of micro-droplet ejection units 100 are staggered to increase the nozzle resolution.

[0053] Furthermore, the lower electrode leads 45 of the two adjacent rows of micro-droplet ejection units 100 are placed adjacent to each other and connected to the common ground line 200, and the upper electrode leads 46 of each micro-droplet ejection unit 100 are independently provided with a driving electrode 300, which is connected to an external driving circuit through the driving electrode 300 to independently drive each ejection unit to work.

[0054] It should be pointed out that the above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with the technology to understand the content of the present invention and implement it accordingly, and they cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A micro-droplet ejection unit, comprising a nozzle layer, a pressure chamber base layer, a deformable diaphragm, a piezoelectric actuator and a packaging protection layer arranged in sequence, characterized in that: The pressure chamber base layer is provided with a pressure chamber, a first liquid inlet channel and a first liquid outlet channel, the pressure chamber extends along a first direction, the first liquid inlet channel extends along a second direction, the first liquid outlet channel extends along a third direction, the first end of the first liquid inlet channel is openly connected to the side of the first end of the pressure chamber, the first end of the first liquid outlet channel is openly connected to the side of the second end of the pressure chamber, and the nozzle layer is provided with a nozzle connected to the pressure chamber; A liquid inlet and a liquid outlet are provided in the encapsulation protection layer, the liquid inlet extends along a fourth direction and is connected to the second end of the first liquid inlet channel, and the liquid outlet extends along a fifth direction and is connected to the second end of the first liquid outlet channel; Among them, with the XYZ three-dimensional coordinate system as a reference, the first direction, the second direction and the third direction are located in the XY plane, the second direction and the first direction have an angle α1, the third direction and the first direction have an angle β1, the fourth direction and the Z axis have an angle θ1 of 0° to 30°, and the fifth direction and the Z axis have an angle θ2 of 0° to 30°.

2. The micro-droplet ejection unit according to claim 1, characterized in that: The angle α1 is 60° to 120°, and the angle β1 is 60° to 120°.

3. The micro-droplet ejection unit according to claim 2, characterized in that: The angle α1 is 85° to 95°, the angle β1 is 85° to 95°, the angle θ1 is 0° to 5°, and the angle θ2 is 0° to 5°.

4. The micro-droplet ejection unit according to claim 1, characterized in that: The included angle α1 and the included angle β1 have the same angle value, and the included angle θ1 and the included angle θ2 have the same angle value.

5. The micro-droplet ejection unit according to claim 4, characterized in that: The side surface where the first end of the first liquid inlet channel communicates with the pressure chamber and the side surface where the first end of the first liquid outlet channel communicates with the pressure chamber are two opposite side surfaces.

6. The micro-droplet ejection unit according to claim 1, characterized in that: The pressure chamber has a width D perpendicular to the first direction, the first liquid inlet channel has a length L1 along the second direction, and the first liquid outlet channel has a length L2 along the third direction. The length L1 is 0.5 to 2 times the width D, and the length L2 is 0.5 to 2 times the width D.

7. The micro-droplet ejection unit according to claim 6, characterized in that: The length L1 and the length L2 have the same length value.

8. The micro-droplet ejection unit according to any one of claims 1 to 7, characterized in that: A second liquid inlet channel and a second liquid outlet channel are also provided in the base layer of the pressure chamber, the second liquid inlet channel extends along a sixth direction, and the second liquid outlet channel extends along a seventh direction, the sixth direction and the seventh direction are located in the XY plane, an angle α2 is formed between the sixth direction and the second direction, and an angle β2 is formed between the seventh direction and the third direction; a first end of the second liquid inlet channel is connected to a second end of the first liquid inlet channel, the liquid inlet port is connected to a second end of the second liquid inlet channel, a first end of the second liquid outlet channel is connected to a second end of the first liquid outlet channel, and the liquid outlet port is connected to a second end of the second liquid outlet channel.

9. A micro-droplet ejection device, characterized in that: It comprises the micro-droplet ejection unit as described in any one of claims 1 to 8.

10. The micro-droplet ejection device according to claim 9, characterized in that: The micro-droplet ejection device comprises a plurality of micro-droplet ejection units arranged in an array of M rows×N columns, where M is an integer greater than 1 and N is an integer greater than 1; Wherein, the first direction in which the length of the pressure chamber in the micro-droplet ejection unit extends is obliquely intersected with the row direction of the array arrangement.

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