An arrayed fluid ejection head addressable jetting device

Abstract

The application discloses an arrayed electrofluidic nozzle addressable ejection device, comprising an arrayed electrofluidic nozzle and a high-voltage power supply circuit, wherein the arrayed electrofluidic nozzle comprises an ink cartridge, a nozzle plate, a nozzle and a cross-shaped electrode; the ink cartridge is arranged on the top of the nozzle plate, and the ink cartridge is provided with an ink inlet and an ink outlet; the nozzle is provided with a plurality of nozzles and is uniformly arranged on the nozzle plate and communicated with the ink cartridge; the bottom of the nozzle plate is provided with the cross-shaped electrode around the position corresponding to each nozzle; and the high-voltage power supply circuit is electrically connected with each cross-shaped electrode; the cross-shaped electrode is composed of two x electrodes located on the x axis and two y electrodes located on the y axis; the x electrode is a driving electrode, which provides driving force for electrofluidic ejection; and the y electrode is a control electrode, which controls the nozzle tip electric field by adjusting the y electrode voltage, thereby realizing addressable ejection. The application has the advantages of simple structure, convenient maintenance and stable performance.

Description

Technical Field

[0001] This invention relates to the field of inkjet printing device technology, and more specifically to an addressable jetting device with arrayed electrohydrodynamic printheads. Background Technology

[0002] In printed electronics, inkjet printing technology is widely used in the manufacturing of micro and nano electronic devices due to its advantages such as convenient printing and low cost. However, with the continuous innovation of technology, the shortcomings of traditional inkjet printing technology in terms of printing accuracy and printing stability have become increasingly apparent. It is difficult to meet the requirements of large-area high-reliability manufacturing of precision electronic components. Therefore, electrohydrodynamic inkjet printing technology has emerged. Compared with traditional inkjet printing technology, electrohydrodynamic inkjet printing technology has the following advantages: (1) The droplet size is smaller than the nozzle size, reaching 50 μm, thereby achieving high-resolution printing. (2) The liquid selectivity is high. Compared with the traditional 1-20 cP, electrohydrodynamic inkjet printing can adapt to liquids of 1-10000 cP. It is precisely because of these advantages that electrohydrodynamic inkjet printing technology has been successfully applied to many fields such as photoelectric detectors, flexible electronic devices, micro electric thrusters, and functional protein microarrays.

[0003] To achieve diverse printing capabilities for array printheads, addressable control of the jet is necessary. Currently, most arrayed fluid printheads achieve addressable control through external electrode rings. However, due to electric field asymmetry, the jet tends to tilt onto the external electrode ring, leading to jetting malfunctions. Furthermore, since the diameter of the electrode ring is larger than the nozzle diameter, it causes significant inconvenience for the integration of printing equipment and the assembly and maintenance of the printhead.

[0004] Patent CN201410289239.5 proposes a method for achieving independently controllable printing with a printhead, but it requires an external extraction electrode in front of the nozzle. Ink is prone to deflection onto the extraction electrode, damaging the printhead, and the structure is complex and difficult to manufacture. Patent CN201510299992.7 proposes a miniature electrospray chip device and its fabrication method, but its spray chip cannot independently control the printing state of each nozzle. Patent CN202111078207.7 proposes an independently controllable electrofluid printhead, but it has significant limitations regarding the conductivity of the solution. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide an addressable jetting device with an arrayed electrohydrodynamic nozzle.

[0006] The technical solution of the present invention is as follows:

[0007] An addressable ejection device with an arrayed electro-hydraulic nozzle includes an arrayed electro-hydraulic nozzle and a high-voltage power supply circuit. The arrayed electro-hydraulic nozzle includes an ink cartridge, an orifice plate, nozzles, and cross-shaped electrodes. The ink cartridge is disposed on the top of the orifice plate and has an ink inlet and an ink outlet. Several nozzles are evenly arranged on the orifice plate and communicate with the ink cartridge. The bottom of the orifice plate is surrounded by cross-shaped electrodes corresponding to the positions of each nozzle. The high-voltage power supply circuit is electrically connected to each cross-shaped electrode.

[0008] The high-voltage power supply circuit is used to generate two different voltage levels, U1 and U2, to generate the corresponding voltage level for each nozzle to spray or not spray, thereby realizing the spray control of each nozzle.

[0009] The cross-shaped electrode is made of conductive material and is used to apply different voltages to generate an electric field.

[0010] The cross-shaped electrode consists of two x-electrodes located on the x-axis and two y-electrodes located on the y-axis. The x-electrodes are driving electrodes that provide driving force for electrofluid injection, and the y-electrodes are regulating electrodes that control the electric field at the nozzle tip by adjusting the voltage of the y-electrodes, thereby achieving addressable injection.

[0011] Furthermore, the high-voltage power supply circuit is composed of a host computer, a digital main controller, a high-voltage power supply, and a multi-channel high-voltage switch connected in sequence;

[0012] The host computer is a human-computer interaction interface used to convert the pattern to be printed into printing data and send it to the digital main controller. It also controls the output of the high-voltage power supply and the multiple high-voltage switches through software.

[0013] The digital master controller is a microcontroller in the form of a single-chip microcomputer or PLD / FPGA, used for receiving, processing, buffering, outputting and timing logic control of printing data. After receiving the required printing data, the digital master controller converts it into the logic control signals required for the operation of the high-voltage power supply and multiple voltage switches, and then outputs it serially or in parallel to the high-voltage power supply and multiple high-voltage switches according to the given timing.

[0014] The high-voltage power supply is a high-voltage signal generating device used to convert the input low-voltage signal into a high-voltage signal, and connects it to the solution and the cross-shaped electrode through a lead wire to generate an electric field and drive the solution to be sprayed.

[0015] The multi-channel high-voltage switch is a high-voltage-resistant switch in the form of multiple relays or MOSFETs, used to receive printing data from the digital master control and control the electrode voltage state of each nozzle, thereby controlling the opening and closing of the nozzle.

[0016] Furthermore, the nozzle plate is made of insulating material.

[0017] Furthermore, the perforated plate is obtained by processing through holes on an insulating flat plate or a flat plate with insulating material interlayer using laser ablation, photolithography, and sandblasting processes.

[0018] Furthermore, the nozzle plate has a length of 10mm, a width of 10mm, and a thickness of 0.5mm.

[0019] Furthermore, the nozzle is inserted into a through hole in the nozzle plate and bonded using UV-curable adhesive.

[0020] Furthermore, the nozzle uses a 34G stainless steel needle with an inner diameter of 60μm and an outer diameter of 230μm.

[0021] Furthermore, the surface of the nozzle is coated with a Teflon hydrophobic layer.

[0022] Furthermore, the cross-shaped electrode is disposed on the bottom of the nozzle plate by vapor deposition and bonding.

[0023] Furthermore, the surface of the cross-shaped electrode is covered with an insulating layer.

[0024] Compared to existing technologies, the advantages of this invention are as follows: This invention provides an addressable jetting device for an arrayed electrohydrodynamic nozzle. By arranging cross-shaped electrodes at the bottom of the nozzle plate corresponding to the positions of each nozzle, and applying different voltages to the x and y electrodes, the electric field at the tip of the corresponding nozzle is changed, controlling the opening or closing of the nozzle. This ultimately achieves addressable control of the jetting from the arrayed electrohydrodynamic nozzle. Because the cross-shaped electrodes are located at the root of the nozzle, the jet will not tilt onto the electrodes. This invention has the advantages of simple structure, easy maintenance, and stable performance. Attached Figure Description

[0025] To more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This invention provides a schematic diagram of the structure of an addressable jetting device with an arrayed electro-hydraulic nozzle.

[0027] Figure 2 This is a schematic diagram showing the distribution of the cross-shaped electrodes described in this invention;

[0028] Figure 3 This is a control principle diagram of the cross-shaped electrode described in this invention. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0030] To illustrate the technical solution described in this invention, specific embodiments are described below. Example

[0031] Please see Figure 1 This embodiment provides an addressable ejection device with an arrayed current thermal printhead, including an arrayed current thermal printhead and a high-voltage power supply circuit 2. The arrayed current thermal printhead includes an ink cartridge 11, an orifice plate 12, nozzles 13 and cross-shaped electrodes 14. The ink cartridge 11 is disposed on the top of the orifice plate 12. The ink cartridge 11 is provided with an ink inlet 111 and an ink outlet 112. Several nozzles 13 are provided and evenly disposed on the orifice plate 12 and communicate with the ink cartridge 11. The bottom of the orifice plate 12 is surrounded by cross-shaped electrodes 14 corresponding to the positions of each nozzle 13. The high-voltage power supply circuit is electrically connected to each cross-shaped electrode 14.

[0032] The nozzle plate 12 is a perforated flat plate made of insulating materials such as glass or polymers. It can be obtained by machining through holes in an insulating flat plate or a plate with insulating material interlayers using laser ablation, photolithography, or sandblasting processes. The insulating material used in the nozzle plate 12 helps to prevent current transmission between different nozzles, reduces electric field crosstalk, and improves addressable control. The nozzle plate 12 has a length of 10mm, a width of 10mm, and a thickness of 0.5mm.

[0033] The nozzle 13 is made of stainless steel with a 34G needle tip, an inner diameter of 60 μm, and an outer diameter of 230 μm. The nozzle 13 is inserted into the through hole of the spray plate 12 and bonded using UV-curable adhesive.

[0034] Preferably, the surface of the nozzle 13 is coated with a Teflon hydrophobic layer to prevent ink diffusion.

[0035] The cross-shaped electrode 14 is made of conductive material and is used to apply different voltages to generate an electric field. It is deposited on the bottom of the nozzle plate 12 via vapor deposition and bonding. The surface of the cross-shaped electrode 14 is covered with an insulating layer. Figure 2 As shown, it consists of two x electrodes 141 located on the x-axis and two y electrodes 142 located on the y-axis; the x electrodes 141 are driving electrodes that provide driving force for electrofluid injection; the y electrodes 142 are control electrodes that control the electric field at the tip of the nozzle 13 by adjusting the voltage of the y electrodes 142, thereby achieving addressable injection.

[0036] The high-voltage power supply circuit 2 generates two different voltage levels, U1 and U2, to produce corresponding voltage levels for spraying or not spraying at each nozzle 13, thereby achieving spray control of each nozzle 13. Combined with... Figure 3 As shown, the high-voltage power supply circuit 2 consists of a host computer, a digital main controller, a high-voltage power supply, and a multi-channel high-voltage switch connected in sequence. The host computer is a human-machine interface used to convert the desired printing pattern into printing data and send it to the digital main controller. It also controls the output of the high-voltage power supply and the multi-channel high-voltage switch via software. The digital main controller is a microcontroller in the form of a single-chip microcomputer or PLD / FPGA, used for receiving, processing, buffering, outputting, and timing logic control of the printing data. After receiving the required printing data, the digital main controller converts it into the logic control signals required for the operation of the high-voltage power supply and the multi-channel voltage switch. According to the given timing, it is output serially or in parallel to the high-voltage power supply and the multiple high-voltage switch; the high-voltage power supply is a high-voltage signal generating device, used to convert the input low-voltage signal into a high-voltage signal, and connected to the solution and cross-shaped electrode through leads to generate an electric field to drive the solution to spray. Its parameters can be manually adjusted or controlled by the low-voltage signal generated by the digital master control; the multiple high-voltage switch is a high-voltage-resistant switch in the form of multiple relays or MOSFETs, used to receive the printing data from the digital master control and control the electrode voltage state of each nozzle 13, thereby controlling the opening and closing of the nozzle 13.

[0037] When not spraying, a voltage U1 is applied to electrode x 141 and electrode y 142. The surface tension at the solution interface is F. y The electric field force F on the solution at the tip of nozzle 13 E1 At this time, F y >F E1 Nozzle 13 does not spray. When nozzle 13 is turned on, the voltage of y electrode 142 is increased to U2 (U2>U1). The electric field at the tip of nozzle 13 corresponding to this set of cross-shaped electrodes 14 is enhanced, and the electric force on the solution at the tip of nozzle 13 increases to F. E2 At this time, F y <F E2 The nozzle 13 sprays.

[0038] During normal spraying, the surface tension coefficient of the solution is y0, for a diameter of d N The surface tension at the solution interface of nozzle 13 is F. y =4y0 / d N At this time, the same working voltage U1 is applied to the x electrode 141 and y electrode 142 in each set of cross-shaped electrodes 14, and the electric field force on the solution at the tip of the nozzle 13 is... Where E1 is the electric field strength between nozzle 13 and the printing substrate. At this time, Fy > FE1, and all nozzles 13 do not spray. Increasing the voltage of y electrode 142 to U2 (U2 > U1), while keeping the voltage of x electrode 141 unchanged, the electric field at the tip of the corresponding nozzle 13 is enhanced, and the electric field strength increases to E2. The electric force on the solution at the tip of nozzle 13 also increases to F. E2 F y0 <F E2 Nozzle 13 is turned on to spray the solution.

[0039] A PC was selected as the host computer, and a microcontroller was selected as the digital controller. Before using the arrayed electrochemical printhead, the mounting holes on the ink cartridge 11 were aligned with the threaded holes on the experimental platform. The arrayed electrochemical printhead was then fixed to the experimental platform with bolts, and the printhead clamp was adjusted to keep the nozzles 13 parallel to the printing substrate, ensuring that each nozzle 13 was subjected to the same magnitude of electric field force. Then, an ethanol solution was pumped into the ink cartridge 11 through the ink inlet 111 using a flow pump, and air bubbles were expelled from the ink cartridge 11 through the ink outlet 112. When the ink cartridge 11 was filled with ethanol solution, and the printing height was controlled at 1 mm and the ambient temperature at 20℃, the opening voltage of the nozzles 13 was approximately 900V.

[0040] When the arrayed electrochemical printhead is in use, a signal is output from a PC to a microcontroller. The microcontroller then sends the signal to a high-voltage power supply and a multiplexer to control the on / off state of the power supply and the multiplexer, thereby controlling the voltage state of each electrode. First, 800V is applied to the x-electrode 141 and y-electrode 142 in the cross-shaped electrode array. The electric field force on the liquid is less than the surface tension, so all nozzles 13 do not eject. Then, for the nozzle 13 to be activated, the voltage of its corresponding y-electrode 142 is changed to 1200V, while the voltage of the x-electrode 141 remains unchanged. This increases the electric field strength between the nozzle 13 and the printing substrate, making the electric field force on the liquid greater than the surface tension, and the nozzle 13 begins to eject. When the nozzle 13 needs to stop ejecting again, the voltage of the y-electrode 142 is changed back to 800V, while the others remain unchanged, and the nozzle 13 stops ejecting. By controlling the sequential ejection of different nozzles 13, patterned printing is completed.

[0041] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An arrayed fluid ejection head addressable jetting device, characterized by: The device includes an arrayed current fluid printhead and a high-voltage power supply circuit. The arrayed current fluid printhead includes an ink cartridge, an orifice plate, nozzles, and cross-shaped electrodes. The ink cartridge is located on top of the orifice plate and has an ink inlet and an ink outlet. Several nozzles are evenly arranged on the orifice plate and communicate with the ink cartridge. Cross-shaped electrodes are arranged around the bottom of the orifice plate corresponding to the positions of each nozzle. The high-voltage power supply circuit is electrically connected to each cross-shaped electrode. The high-voltage power supply circuit is used to generate two different voltage levels, U1 and U2, to generate the corresponding voltage level for each nozzle to spray or not spray, thereby realizing the spray control of each nozzle. The high-voltage power supply circuit consists of a host computer, a digital main controller, a high-voltage power supply, and a multi-channel high-voltage switch connected in sequence. The host computer is a human-computer interaction interface used to convert the pattern to be printed into printing data and send it to the digital main controller. It also controls the output of the high-voltage power supply and the multiple high-voltage switches through software. The digital master controller is a microcontroller in the form of a single-chip microcomputer or PLD / FPGA, used for receiving, processing, buffering, outputting and timing logic control of printing data. After receiving the required printing data, the digital master controller converts it into the logic control signals required for the operation of the high-voltage power supply and multiple voltage switches, and then outputs it serially or in parallel to the high-voltage power supply and multiple high-voltage switches according to the given timing. The high-voltage power supply is a high-voltage signal generating device used to convert the input low-voltage signal into a high-voltage signal, and connects it to the solution and the cross-shaped electrode through a lead wire to generate an electric field and drive the solution to be sprayed. The multi-channel high-voltage switch is a high-voltage-resistant switch in the form of multiple relays or MOSFETs, used to receive printing data from the digital master control and control the electrode voltage state of each nozzle, thereby controlling the opening and closing of the nozzle. The cross-shaped electrode is made of conductive material and is used to apply different voltages to generate an electric field. The cross-shaped electrode consists of two x-electrodes located on the x-axis and two y-electrodes located on the y-axis. The x-electrodes are driving electrodes that provide driving force for electrofluid injection, and the y-electrodes are regulating electrodes that control the electric field at the nozzle tip by adjusting the voltage of the y-electrodes, thereby achieving addressable injection. By changing the corresponding y-electrode voltage to 1200V while keeping the x-electrode voltage unchanged, the electric field strength between the nozzle and the printing substrate increases. The electric force on the liquid is greater than the surface tension on the liquid, and the nozzle begins to spray.

2. An arrayed fluid ejection head addressable jetting device according to claim 1, wherein: The nozzle plate is made of insulating material.

3. An arrayed fluid ejection head addressable jetting device according to claim 2, wherein: The perforated plate is obtained by processing through holes on an insulating flat plate or a flat plate with insulating material interlayer using laser ablation, photolithography, and sandblasting processes.

4. The arrayed electro-hydraulic nozzle addressable injection device according to claim 3, characterized in that: The nozzle plate has a length of 10mm, a width of 10mm, and a thickness of 0.5mm.

5. The arrayed electro-hydraulic nozzle addressable injection device according to claim 3, characterized in that: The nozzle is inserted into a through hole in the spray plate and bonded using UV-curable adhesive.

6. The arrayed electro-hydraulic nozzle addressable injection device according to claim 5, characterized in that: The nozzle uses a 34G stainless steel needle with an inner diameter of 60μm and an outer diameter of 230μm.

7. The addressable jetting device with arrayed electrohydrodynamic nozzles according to claim 6, characterized in that: The nozzle surface is coated with a Teflon hydrophobic layer.

8. The arrayed electro-hydraulic nozzle addressable injection device according to claim 1, characterized in that: The cross-shaped electrode is set at the bottom of the nozzle plate by vapor deposition and bonding.

9. An addressable jetting device with an arrayed electro-hydraulic nozzle according to claim 1 or 8, characterized in that: The surface of the cross-shaped electrode is covered with an insulating layer.

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