Ultrathin film forming method and ink-jet printing device

Abstract

The present application relates to an ultrathin film forming method and an ink-jet printing device. The method comprises the steps of: acquiring the area of a printing region of a substrate on which printing needs to be performed, and the thickness of a film needing to be printed, so as to obtain the total volume of a required functional ink; presetting the volume of an individual ink droplet as an individual-droplet volume, and on the basis of the total volume of the functional ink, obtaining a required total number of printing passes; presetting the number of X-direction printing passes and the number of Y-direction printing passes; presetting an X-direction printing spacing and a Y-direction printing spacing; acquiring the diffusion radius of the individual ink droplet with the individual-droplet volume on the substrate, and correcting the X-direction printing spacing and the Y-direction printing spacing on the basis of the diffusion radius; performing droplet landing position pattern planning on the basis of parameters of the number of X-direction printing passes, the number of Y-direction printing passes, the X-direction printing spacing and the Y-direction printing spacing; and on the basis of the droplet landing position pattern planning, using a print head module to perform printing on the substrate. In the present application, the film thickness of a formed thin film is more uniform, the use of the functional ink is saved, the forming thickness of the thin film is reduced, and process requirements of an ultrathin display panel are met.

Description

Ultra-thin film forming method and inkjet printing equipment

Technical field

[0001] The present application relates to the technical field of display screen processing, and in particular to an ultra-thin film forming method and inkjet printing equipment. [Background Technology]

[0002] Inkjet printing technology is increasingly being used in industrial production, for the production of large-area pressure sensors, radio frequency identification (RFID) tags, flexible solar cells, and flexible OLEDs. The basic structure of an OLED consists of an anode, a hole injection layer, a hole transport layer, an organic light-emitting layer, an electron transport layer, an electron injection layer, and a cathode. The organic light-emitting layer is sandwiched between electrodes. Most organic substances in the OLED light-emitting layer are very sensitive to atmospheric pollutants, O2, and water vapor. Thin film encapsulation (TFE) can encapsulate OLEDs on flexible substrates, making them bendable and rollable, bringing breakthroughs to flexible display technology. The films used in thin film encapsulation processes can be divided into inorganic films, organic films, and inorganic / organic composite films. Organic / inorganic composite thin film encapsulation is considered the most promising encapsulation technology due to its excellent performance.

[0003] The processing technologies for the organic film layer of the composite thin film include evaporation, vacuum chemical vapor deposition, thermal chemical vapor deposition polymerization (TCVDPF), and inkjet printing. Compared with other technologies, inkjet printing has the advantages of low cost, reduced material waste, and fast processing speed.

[0004] In related technologies, when using inkjet printing technology to print thin films, the substrate is first scanned and printed, and then the grayscale pattern of the film is used to determine whether there are missing parts of the film. Then, the printing is re-planned based on the missing parts, and the number of droplets in different areas of the substrate is adjusted to compensate for subsequent thin film printing and realize thin film encapsulation printing.

[0005] However, when printing thin films in related technologies, compensation printing is performed based on the missing parts of the film, which can easily cause uneven film thickness and increase the amount of functional liquid used for film printing, resulting in waste of functional liquid and increasing the thickness of the formed film, making it difficult to meet the process requirements of ultra-thin display panels.

[0006] [Summary of the invention]

[0007] The embodiments of the present application provide an ultra-thin film forming method to solve the technical problems in the related art such as uneven film thickness, waste of functional liquid, and thick film thickness that cannot meet the process requirements of ultra-thin display panels.

[0008] In a first aspect, a method for forming an ultra-thin film is provided, comprising the following steps:

[0009] Obtaining the area of ​​the printing area of ​​the substrate to be printed, the required printing film thickness, and the required total volume of the functional liquid;

[0010] The volume of a single droplet is preset as the single droplet volume, and the total number of required prints is obtained according to the total amount of functional liquid;

[0011] Preset the X-direction printing times and Y-direction printing times according to the total printing times and the shape of the printing area;

[0012] Preset the X-direction printing spacing and Y-direction printing spacing based on the X-direction printing times, Y-direction printing times and printing area;

[0013] Obtaining the diffusion radius of a single droplet of a single droplet volume on the substrate, and correcting the X-direction printing spacing and the Y-direction printing spacing according to the diffusion radius so that adjacent single droplets on the substrate touch each other after diffusion;

[0014] Plan the dot pattern based on the parameters of X-direction printing times, Y-direction printing times, X-direction printing spacing, and Y-direction printing spacing;

[0015] According to the landing pattern planning, the nozzle module is used to print on the substrate.

[0016] In some embodiments, after correcting the X-direction printing spacing and the Y-direction printing spacing according to the diffusion radius, the method further includes correcting the X-direction printing spacing and the Y-direction printing spacing a second time:

[0017] Get the radius of the deviation area of ​​the droplet landing point;

[0018] The X-direction printing pitch and the Y-direction printing pitch are both within a range from a difference between twice the diffusion radius and twice the radius of the deviation area to twice the twice the diffusion radius.

[0019] In some embodiments, obtaining the radius of the deviation area of ​​the droplet landing point includes:

[0020] Obtain the Y-direction spacing between adjacent nozzles of the printhead module to obtain the theoretical landing position of droplets ejected by all nozzles when the printhead module prints along a straight line in the Y direction;

[0021] Make all nozzles of the print head module print in the Y direction to obtain the actual landing points of the droplets ejected by all nozzles when the print head module prints along a straight line in the Y direction;

[0022] The actual landing point of the droplets ejected by a nozzle corresponds to the theoretical landing point of the droplets ejected by the nozzle, and based on this, the offsets in the X direction and the Y direction between the actual landing points of the droplets ejected by the remaining nozzles and the theoretical landing points of the droplets ejected by the nozzle are determined;

[0023] The radius of the deviation area is calculated based on the maximum value of the offset in the X direction and the maximum value of the offset in the Y direction.

[0024] In some embodiments, obtaining the diffusion radius of a single droplet on the substrate of the single droplet volume includes:

[0025] Obtaining multiple substrates of varying cleanliness levels;

[0026] The nozzle module prints droplets of various volumes on substrates of varying cleanliness levels, and measures the diffusion radius of all droplets.

[0027] According to the diffusion radius of all droplets, a database of droplet diffusion radius is established;

[0028] The droplet spreading radius database is used to obtain the droplet spreading radius corresponding to the cleanliness level of the printed substrate and the volume of a single droplet.

[0029] In some embodiments, the nozzle module includes multiple rows of nozzles extending along the Y direction, and multiple nozzles in different rows are staggered in the Y direction; and printing on the substrate using the nozzle module according to the landing pattern planning includes:

[0030] Determining the positions of the deviation areas of all the droplet landing points on the substrate according to the positions of all the droplet landing points on the substrate and the radius of the deviation areas;

[0031] Obtain the relative position information of all nozzles of the printhead module and the deviation areas of all droplet landing points on the substrate;

[0032] Determine the nozzle corresponding to the deviation area of ​​all droplet landing points;

[0033] The nozzle module moves along the X direction above the substrate to scan and print on the substrate.

[0034] In some embodiments, determining the nozzles corresponding to the deviation areas of all droplet landing points includes:

[0035] Determine one by one whether the Y-axis position information of the plurality of nozzles is within the Y-axis position information range of the deviation area of ​​the droplet landing point; if so, the nozzle is the nozzle corresponding to the deviation area of ​​the droplet landing point;

[0036] If the deviation area of ​​a droplet landing point has multiple corresponding nozzles, the nozzle whose Y-axis position information is closest to the middle of the Y-axis position information range of the deviation area of ​​the droplet landing point is selected as the corresponding nozzle of the deviation area of ​​the droplet landing point.

[0037] In some embodiments, the preset volume of a single droplet is a single droplet volume, including:

[0038] The volume of a single droplet ranges from 1 to 30 picoliters.

[0039] In some embodiments, the step of printing on the substrate using the nozzle module according to the landing pattern planning further includes:

[0040] The substrate is cleaned so that the surface contact angle of the substrate is 5 to 10 degrees.

[0041] The beneficial effects of the technical solution provided by this application include:

[0042] The embodiment of the present application provides a method for forming an ultra-thin film. First, the total amount of functional liquid required is calculated based on the film thickness of the desired film and the area of ​​the printing area. Then, the volume of a single droplet is selected to calculate the total number of prints. This is used to plan the number of X-direction prints and the number of Y-direction prints. In combination with the area of ​​the printing area, the X-direction print spacing and the Y-direction print spacing are preset. Subsequently, the X-direction print spacing and the Y-direction print spacing are corrected based on the diffusion radius of the droplets, and all the landing points of the printing area can be planned. Through the planning of the landing pattern, the droplets can be reasonably distributed and printed to the printing area of ​​the substrate to cover the printing area and obtain a film of the desired thickness. Among them, the X-direction print spacing and the Y-direction print spacing are corrected based on the diffusion radius of the droplets to ensure that each droplet contacts and covers the printing area after diffusion, thereby ensuring the film quality. In addition, it also avoids excessive overlap of the droplet diffusion area, which increases the film thickness, and greatly reduces the thickness of the formed film. Therefore, the film thickness of the formed film is more uniform, the use of functional liquid is saved, the forming thickness of the film is thinned, and it meets the process requirements of ultra-thin display panels.

[0043] In a second aspect, an inkjet printing device is provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program implements the steps of the ultra-thin film forming method as described above when executed by the processor.

[0044] Another embodiment of the present application provides an inkjet printing device. Since the inkjet printing device implements the steps of the above-mentioned ultra-thin film forming method, the beneficial effects of the inkjet printing device are consistent with the beneficial effects of the above-mentioned ultra-thin film forming method, which will not be repeated here.

[0045] In a third aspect, an inkjet printing system is provided, the inkjet printing system comprising:

[0046] substrate;

[0047] A print head device, comprising: a plurality of print heads and an execution unit; wherein the execution unit receives a control instruction sent by a control device and controls the plurality of print heads to execute the control instruction;

[0048] A control device is used to send control instructions to the nozzle device through the ultra-thin film forming method as described above.

[0049] Another embodiment of the present application provides an inkjet printing system. Since the inkjet printing system is processed using the above-mentioned ultra-thin film forming method, the beneficial effects of the inkjet printing system are consistent with the beneficial effects of the above-mentioned ultra-thin film forming method, which will not be repeated here.

Brief Description of the Drawings

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0051] FIG1 is a flow chart of an ultra-thin film forming method provided in an embodiment of the present application;

[0052] FIG2 is a schematic diagram of a substrate printing area provided by an embodiment of the present application showing a state where droplets have spread and are not fused after printing;

[0053] FIG3 is a schematic diagram of the minimum spacing of the X-direction printing spacing or the Y-direction printing spacing provided in an embodiment of the present application;

[0054] FIG4 is a schematic diagram of the maximum spacing of the X-direction printing spacing or the Y-direction printing spacing provided by an embodiment of the present application;

[0055] FIG5 is a schematic diagram of a nozzle module provided in an embodiment of the present application;

[0056] FIG6 is a schematic diagram showing a comparison between the actual droplet landing position and the theoretical droplet landing position when the nozzle module according to an embodiment of the present application prints a straight line along the Y direction;

[0057] FIG7 is a schematic diagram of an inkjet printing device provided in another embodiment of the present application. [Specific implementation method]

[0058] To make the purpose, technical solutions, and advantages of the embodiments of this application more clear, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0059] The embodiments of the present application provide an ultra-thin film forming method and inkjet printing equipment. The ultra-thin film forming method plans the number of X-direction prints, the number of Y-direction prints, the X-direction print spacing, and the Y-direction print spacing based on the printing area area, the required printing film thickness, and the volume of a single droplet. The X-direction print spacing and the Y-direction print spacing are corrected using the diffusion radius of the droplets. By planning all the landing points, the droplets can be reasonably distributed and printed to the printing area of ​​the substrate to cover the printing area. Therefore, the film thickness of the formed film is more uniform, the use of functional liquid is saved, the forming thickness of the film is thinned, and it is adapted to the process requirements of ultra-thin display panels. The present application solves the technical problems in the related art of uneven film thickness, waste of functional liquid, and thick film thickness that are difficult to meet the process requirements of ultra-thin display panels.

[0060] 1 , a method for forming an ultra-thin film includes steps S100 - S700 .

[0061] S100: Obtain the area of ​​the printing region of the substrate to be printed and the required printing film thickness, and obtain the required total volume of the functional liquid.

[0062] S200 , presetting the volume of a single droplet as a single droplet volume, and obtaining the required total number of prints according to the total amount of the functional liquid.

[0063] S300 , presetting the X-direction printing times and the Y-direction printing times according to the total printing times and the shape of the printing area.

[0064] S400 , presetting an X-direction printing spacing and a Y-direction printing spacing according to the X-direction printing times, the Y-direction printing times, and the printing area.

[0065] S500 , obtaining a diffusion radius of a single droplet of a single droplet volume on a substrate, and correcting an X-direction printing pitch and a Y-direction printing pitch according to the diffusion radius so that adjacent single droplets on the substrate touch each other after diffusion.

[0066] S600: Correct the X-direction printing distance and the Y-direction printing distance for the second time.

[0067] S700 , planning a dot pattern according to parameters of the X-direction printing times, the Y-direction printing times, the X-direction printing spacing, and the Y-direction printing spacing.

[0068] S800: Print on the substrate using the nozzle module according to the landing pattern planning.

[0069] Referring to Figures 1 and 2, this arrangement ensures that the droplets are distributed and printed onto the substrate's print area, covering the print area and producing a film of the desired thickness. The X- and Y-direction print spacings are modified based on the droplet diffusion radius to ensure that each droplet contacts and covers the print area after diffusion, guaranteeing film quality. This also prevents excessive overlap of the droplet diffusion area, which would increase film thickness, significantly reducing the thickness of the resulting film. As a result, the resulting film has a more uniform thickness, saves on the use of functional liquid, and reduces the film's thickness, meeting the process requirements of ultra-thin display panels.

[0070] In step S100, the area of ​​the printing area of ​​the substrate to be printed and the required printing film thickness are obtained to obtain the required total volume of the functional liquid. Specifically:

[0071] The shape of the desired print location on the substrate is obtained, and the desired print location on the substrate is divided into multiple rectangular print areas. The areas of the multiple print areas are measured to obtain the area of ​​the total print area. This arrangement, by dividing the print location on the substrate into multiple print areas based on its shape, facilitates printing on each print area sequentially. Furthermore, by combining multiple print areas, adaptive printing can be achieved for different shapes of print locations on the substrate.

[0072] The required printing film thickness is obtained according to the process requirements. In this embodiment, a film thickness of 0.6 microns can be achieved.

[0073] Using formula 1, the total volume of the required functional fluid can be obtained.

[0074] Formula 1: H = V / S

[0075] Where H is the required printing film thickness, in um; V is the required total amount of functional liquid, in pl; S is the printing area, in um 2 .

[0076] In step S200, the volume of a single droplet is preset as the single droplet volume, and the total number of required prints is obtained according to the total amount of functional liquid. Specifically:

[0077] The volume of a single droplet is preset based on process requirements and the print parameters of the printhead module. In this embodiment, the volume of a single droplet is 1 to 30 picoliters to meet the droplet diffusion requirements and the process requirements of ultra-thin printing. In this embodiment, a piezoelectric printhead or an electrofluidic printhead is used for printing to meet the printing requirements of a single droplet volume.

[0078] According to formula 2, the total number of prints can be obtained.

[0079] Formula 2: n = V / V0

[0080] Where n is the total number of prints, V is the total amount of functional fluid required, in pl; V0 is the volume of a single droplet, in pl.

[0081] In step S300, the X-direction printing times and the Y-direction printing times are preset according to the total printing times and the shape of the printing area. Specifically:

[0082] The printing area is in the shape of a rectangle, with its length direction being the X direction and its width direction being the Y direction. In this embodiment, the X direction and the Y direction are the X-axis direction and the Y-axis direction in the figure, respectively.

[0083] The X-direction print count and the Y-direction print count are preset based on the lengths of the print area in the X and Y directions. The product of the X-direction print count and the Y-direction print count is the total print count. Specifically, the X-direction print count and the Y-direction print count can be preset based on the ratio of the X-direction and Y-direction lengths of the print area.

[0084] In step S400, the X-direction printing spacing and the Y-direction printing spacing are preset according to the X-direction printing times, the Y-direction printing times and the printing area. Specifically:

[0085] The relationship between the X-direction printing spacing, the X-direction printing times, and the X-direction length of the printing area is determined according to Formula 3.

[0086] Formula 3: L X =l X *n X

[0087] Among them, L X The X-axis length of the printing area, in um, l X The X-axis printing spacing, in um, n X The number of times to print in X direction.

[0088] The relationship between the Y-direction printing pitch, the Y-direction printing times, and the Y-direction length of the printing area is determined according to Formula 4.

[0089] Formula 4: L Y =l Y *n Y

[0090] Among them, L Y Y-axis length of the printing area, in um, l Y Y-axis printing spacing, unit is um, n Y The number of times to print in X direction.

[0091] Combining Formula 3 and Formula 4, the product of the X-direction printing times and the Y-direction printing times is the total printing times, and the product of the X-direction length of the printing area and the Y-direction length of the printing area is the printing area, to obtain Formula 5:

[0092] Formula 5: lX *l Y =S / (n X *n Y )

[0093] In this way, the product of the X-direction printing spacing and the Y-direction printing spacing is known, and the X-direction printing spacing and the Y-direction printing spacing can be preliminarily preset.

[0094] In step S500, the diffusion radius of a single droplet of a single droplet volume on the substrate is obtained, and the X-direction printing spacing and the Y-direction printing spacing are corrected according to the diffusion radius so that adjacent single droplets on the substrate touch each other after diffusion. Specifically:

[0095] By obtaining the diffusion radius of a single droplet on the substrate, the X- and Y-direction print spacing can be corrected. When correcting the X- and Y-direction print spacing, the X-direction print spacing must be less than twice the diffusion radius of the single droplet on the substrate to ensure that adjacent droplets contact each other after diffusion. This ensures that missing parts of the formed film are less likely to occur after printing, ensuring print quality.

[0096] The process of obtaining the diffusion radius of a single droplet of a single droplet volume on the substrate includes steps S510 to S540 .

[0097] S510 , obtaining a plurality of substrates with different cleanliness levels.

[0098] S520 , enabling the nozzle module to print a plurality of droplets of different volumes on a plurality of substrates with different cleanliness levels, and measuring the diffusion radius of all the droplets.

[0099] S530: Establish a database of droplet diffusion radius according to the diffusion radius of all droplets.

[0100] S540 , using a database of droplet spreading radii, obtain a droplet spreading radius corresponding to the cleanliness level of the printed substrate and the volume of a single droplet.

[0101] In step S510, a plurality of substrates with different cleanliness levels are obtained. Specifically:

[0102] The substrates are cleaned to varying degrees using a substrate cleaning device to change the surface contact angle of the substrates, thereby obtaining substrates with various surface contact angles. In this embodiment, the surface contact angles of the multiple substrates are increased by 0.5 degrees, and the surface contact angles of the multiple substrates range from 3 to 20 degrees. The surface contact angle is the angle of a droplet after it lands on the substrate.

[0103] In step S520, the nozzle module prints a plurality of droplets of different volumes on a plurality of substrates of different cleanliness levels, and measures the diffusion radius of all the droplets. Specifically:

[0104] The printhead module parameters for each print were kept consistent with the actual print parameters. The printhead module was then used to print droplets of various volumes onto multiple substrates of varying cleanliness. In this example, droplets of varying volumes were printed multiple times onto each substrate, ranging from 1 to 50 picoliters. The droplet volumes were increased in 0.5 picoliter increments. After printing, the diffusion radius of all droplets was measured using a high-magnification camera.

[0105] In step S530, a database of droplet diffusion radius is established based on the diffusion radius of all droplets. Specifically:

[0106] The database of droplet spreading radius contains the corresponding droplet spreading radii when droplets of different volumes are printed on substrates of different cleanliness levels.

[0107] In step S540, the database of droplet spreading radius is used to obtain the droplet spreading radius corresponding to the cleanliness level of the printed substrate and the volume of a single droplet. Specifically:

[0108] According to the cleanliness of the required printing substrate and the volume of a single droplet to be printed, the corresponding droplet spreading radius is obtained from the droplet spreading radius database, so as to quickly and easily obtain the droplet spreading radius.

[0109] With this arrangement, when using droplets of different single droplet volumes to print on substrates of different cleanliness levels, the diffusion radius of the droplet can be quickly determined, thereby speeding up the adjustment efficiency before printing.

[0110] 3 to 6 , step S600 , which is a secondary correction of the X-direction printing spacing and the Y-direction printing spacing, specifically includes steps S610 - S620 .

[0111] S610: Obtain the radius of the deviation area of ​​the droplet landing point.

[0112] S620 , ensuring that both the X-direction printing pitch and the Y-direction printing pitch are within a range from a difference between twice the diffusion radius and twice the radius of the deviation area to twice the twice the diffusion radius.

[0113] In this way, the radius of the deviation area of ​​the droplet landing point is added to correct the X-direction printing spacing and the Y-direction printing spacing to ensure that after the adjacent droplets spread, the adjacent droplet spreading areas are not prone to excessive overlap, which facilitates the formation of thinner films.

[0114] Wherein, step S610, obtaining the radius of the deviation area of ​​the droplet landing point, specifically includes steps S611-S614.

[0115] S611. Obtain the Y-direction spacing of all nozzles of the print head module to obtain the theoretical landing positions of the droplets ejected by all nozzles when the print head module prints along a straight line in the Y direction.

[0116] S612: Enable the multiple nozzles of the nozzle module to print in the Y direction to obtain actual landing positions of the droplets ejected by all the nozzles when the nozzle module prints along a straight line in the Y direction.

[0117] S613. The actual landing point of the droplets ejected by a nozzle corresponds to the theoretical landing point of the droplets ejected by the nozzle, and based on this, the actual landing point of the droplets ejected by the remaining nozzles is determined to have an offset in the X direction and an offset in the Y direction relative to the theoretical landing point of the droplets ejected by the nozzle.

[0118] S614 : Calculate the radius of the deviation area according to the maximum value of the offset in the X direction and the maximum value of the offset in the Y direction.

[0119] In step S611, the spacing between adjacent nozzles of the printhead module in the Y direction is obtained to obtain the theoretical landing position of the droplets ejected by all nozzles when the printhead module prints along a straight line in the Y direction. Specifically:

[0120] According to the parameters of the selected nozzle module, the spacing between adjacent nozzles in the Y direction can be determined. In this embodiment, the nozzle module includes multiple rows of nozzles extending along the Y direction, and multiple nozzles in different rows are staggered in the Y direction to improve the printing density.

[0121] Based on the Y-direction spacing between adjacent nozzles of the printhead module, we can know the theoretical landing points of the droplets ejected by all nozzles when the printhead module prints along a straight line in the Y direction. That is, all the nozzles of the printhead module are arranged along the Y direction.

[0122] In step S612, all nozzles of the print head module are made to print in the Y direction, so as to obtain the actual landing points of the droplets ejected by all nozzles when the print head module prints along a straight line in the Y direction. Specifically:

[0123] Use all nozzles of the print head module to print along a straight line in the Y direction. After printing a straight line, the actual landing point of the droplets sprayed by all nozzles can be known.

[0124] Referring to Figures 3 to 6, in step S613, the actual landing point of a droplet ejected from a nozzle is compared with the theoretical landing point of the droplet ejected from the nozzle, and this is used as a reference to determine the offset in the X direction and the Y direction between the actual landing point of the droplets ejected from the remaining nozzles and the theoretical landing point of the droplets ejected from the nozzle. Specifically:

[0125] A correspondence is established between the actual landing point of a droplet ejected from a nozzle and the theoretical landing point of the droplet ejected from the nozzle. In this embodiment, a nozzle at the outermost edge in the Y direction is selected. The theoretical landing point coordinates of a droplet ejected from a nozzle are (X0, Y0), and the actual landing point coordinates of the droplet ejected from the nozzle are (X1, Y1). The absolute value of the corresponding difference in the X direction, ΔX, is obtained by subtracting X1 from X0, and the corresponding difference in the Y direction, ΔY, is obtained by subtracting Y1 from Y0.

[0126] Based on the absolute value ΔX of the corresponding difference in the X direction and the corresponding difference ΔY in the Y direction, the offsets in the X direction and the Y direction between the actual landing positions of the droplets ejected by the remaining nozzles and the theoretical landing positions of the droplets ejected by the nozzles are calculated.

[0127] Specifically, the coordinates of the theoretical landing points of the droplets ejected from the remaining nozzles are (a 01 , b 01 )、(a 02 , b 02 )...(a 0n , b 0n ), correspondingly, the coordinates of the actual landing points of the droplets ejected by the other nozzles are (a 11 , b 11 )、(a 12 , b 12 )...(a 1n , b 1n ).

[0128] Formula 6 can be used to calculate the offset in the X direction between the actual landing position of the droplets ejected by the remaining nozzles and the theoretical landing position of the droplets ejected by the nozzle.

[0129] Formula 6: D xn =||a 1n -a 0n ∣-ΔX∣

[0130] The X-axis offset D between the actual landing position of the droplets ejected by all other nozzles and the theoretical landing position of the droplets ejected by the nozzle can be obtained. x1 、D x2 、D x3 ...D xn .

[0131] Formula 7 can be used to calculate the Y-axis offset between the actual landing position of the droplets ejected by the remaining nozzles and the theoretical landing position of the droplets ejected by the nozzle.

[0132] Formula 6: D Yn =||b 1n -b 0n ∣-ΔY∣

[0133] The offset D in the Y direction between the actual landing position of the droplets ejected by all other nozzles and the theoretical landing position of the droplets ejected by the nozzle can be obtained. Y1 、D Y2 、D Y3 ...D Yn .

[0134] In step S614, the radius of the deviation area is calculated based on the maximum value of the offset in the X direction and the maximum value of the offset in the Y direction. Specifically:

[0135] According to formula 7, the maximum value D of the X-direction offset is used. XMAX and the maximum value of the Y-direction offset D YMAX Calculate the radius R0 of the deviation area.

[0136] Formula 7: R0 2 =D XMAX 2 *D YMAX 2

[0137] The radius of the deviation area can be calculated in microns.

[0138] In step S620, both the X-direction printing spacing and the Y-direction printing spacing are within the range of the difference between twice the diffusion radius and twice the radius of the deviation area to twice the twice the diffusion radius. Specifically:

[0139] l X The range is between 2(R-R0) and 2R, where R is the diffusion radius and R0 is the radius of the deviation area.

[0140] l Y The range is between 2(R-R0) and 2R, where R is the diffusion radius and R0 is the radius of the deviation area.

[0141] By setting it this way, the X-direction printing spacing and the Y-direction printing spacing meet the requirements, and the X-direction printing spacing and the Y-direction printing spacing can be further corrected to ensure that after the adjacent droplets spread, the adjacent droplet diffusion areas are not prone to excessive overlap, thereby facilitating the formation of thinner films.

[0142] In step S700, the dot pattern is planned based on the parameters of the number of X-direction printing times, the number of Y-direction printing times, the X-direction printing spacing, and the Y-direction printing spacing. Specifically:

[0143] According to the parameters of the X-direction printing number, the Y-direction printing number, the X-direction printing spacing and the Y-direction printing spacing, the positions of all the landing points in the printing area on the substrate can be determined, thereby realizing the landing point pattern planning.

[0144] Referring to Figure 5 , step S800 involves printing on a substrate using a nozzle module according to the planned dot pattern. The nozzle module used for this printing includes multiple rows of nozzles extending along the Y direction, with the nozzles in different rows staggered in the Y direction. Step S800 includes steps S810-S840.

[0145] S810 , determining the positions of the deviation areas of all the droplet landing points on the substrate according to the positions of all the droplet landing points on the substrate and the radius of the deviation areas.

[0146] S820: Obtain relative position information of all nozzles of the printhead module and deviation areas of all droplet landing points on the substrate.

[0147] S830: Determine the nozzles corresponding to the deviation areas of all droplet landing points.

[0148] S840 , moving the nozzle module above the substrate along the X direction to scan and print on the substrate.

[0149] This setting matches all droplet landing points with the nozzles of the nozzle module, ensuring that the nozzle most suitable for the droplet landing point is selected for spraying, further ensuring the accuracy of the droplet landing point.

[0150] In step S810, the positions of the deviation areas of all the droplet landing points on the substrate are determined based on the positions of all the droplet landing points on the substrate and the radius of the deviation areas. Specifically:

[0151] The deviation area of ​​the droplet landing point is distributed in a circular manner. Let the position coordinates of the droplet landing point be (P, Q), and the coordinate range of the deviation area of ​​the droplet landing point be (P±R0, Q±R0).

[0152] In step S820, relative position information of deviation areas of all nozzles of the print head module and all droplet landing points on the substrate is obtained.

[0153] By using a visual inspection camera to capture the position of the marking points in the printing area on the substrate, the relative position of the nozzle module and the printing area of ​​the substrate can be determined. In this way, the relative position information of the deviation areas of all nozzles of the nozzle module and all droplet landing points on the substrate can be determined.

[0154] In step S830, the nozzles corresponding to the deviation areas of all droplet landing points are determined. Specifically:

[0155] During printing, the print head module moves along the X direction. When the nozzle of the print head module moves to the planned landing point, the coordinate information of all nozzles is (A1, B1), (A2, B2), (A3, B3), ... (A n , B n ).

[0156] Determine one by one whether the Y-axis position information of multiple nozzles is within the Y-axis position information range of the deviation area of ​​the droplet landing point; if so, the nozzle is the corresponding nozzle of the deviation area of ​​the droplet landing point. n Whether it is within the range of Q±R0, and select the nozzle that meets the conditions as the required nozzle for the planned droplet landing point.

[0157] If the deviation area of ​​a droplet landing point has multiple corresponding nozzles, the nozzle whose Y-axis position information is closest to the middle of the Y-axis position information range of the deviation area of ​​the droplet landing point is selected as the corresponding nozzle of the deviation area of ​​the droplet landing point. n The nozzle with the smallest difference from R0 is selected as the nozzle used for the planned droplet landing point.

[0158] This arrangement can reduce the impact of droplet landing point errors caused by nozzle position errors and improve the droplet landing accuracy.

[0159] 2 , finally, the print head module is used to print on the print area of ​​the substrate to form a film of the desired thickness.

[0160] The embodiment of the present application provides a method for forming an ultra-thin film. First, the total amount of functional liquid required is calculated based on the film thickness of the desired film and the area of ​​the printing area. Then, the volume of a single droplet is selected to calculate the total number of prints. This is used to plan the number of X-direction prints and the number of Y-direction prints. In combination with the area of ​​the printing area, the X-direction print spacing and the Y-direction print spacing are preset. Subsequently, the X-direction print spacing and the Y-direction print spacing are corrected based on the diffusion radius of the droplets, and all the landing points of the printing area can be planned. Through the planning of the landing pattern, the droplets can be reasonably distributed and printed to the printing area of ​​the substrate to cover the printing area and obtain a film of the desired thickness. Among them, the X-direction print spacing and the Y-direction print spacing are corrected based on the diffusion radius of the droplets to ensure that each droplet contacts and covers the printing area after diffusion, thereby ensuring the film quality. In addition, it also avoids excessive overlap of the droplet diffusion area, which increases the film thickness, and greatly reduces the thickness of the formed film. Therefore, the film thickness of the formed film is more uniform, the use of functional liquid is saved, the forming thickness of the film is thinned, and it meets the process requirements of ultra-thin display panels.

[0161] Another embodiment of the present application provides an inkjet printing device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the computer program, when executed by the processor, implements the steps of the ultra-thin film forming method described above.

[0162] Specifically, the inkjet printing control device may be a device such as an MCU (Microcontroller Unit), a PC (Personal Computer), a tablet computer, a portable computer, or a server.

[0163] As shown in Figure 7, the inkjet printing control device may include: a processor, such as a central processing unit (CPU), a communication bus, a user interface, a network interface, and a memory. Among them, the communication bus is used to realize the connection and communication between these components. The user interface may include a display screen (Display), an input unit such as a keyboard (Keyboard), and the optional user interface may also include a standard wired interface and a wireless interface. The network interface may optionally include a standard wired interface and a wireless interface (such as a wireless security (WIreless-FIdelity, WI-FI) interface). The memory may be a high-speed random access memory (Random Access Memory, RAM) memory, or a stable non-volatile memory (Non-Volatile Memory, NVM), such as a disk memory. The memory may also be a storage device independent of the aforementioned processor.

[0164] Those skilled in the art will appreciate that the device structure shown in FIG. 7 does not limit the inkjet printing control device and may include more or fewer components than shown, or a combination of certain components, or a different arrangement of components.

[0165] As shown in FIG. 7 , a memory as a computer storage medium may include an operating system, a network communication module, a user interface module, and an inkjet printing control application program.

[0166] In the device shown in Figure 7, the network interface is mainly used to connect to the background server and communicate data with the background server; the user interface is mainly used to connect to the client and communicate data with the client; and the processor can be used to call the inkjet printing control program stored in the memory to implement the operations in the ultra-thin film forming method provided in the above embodiment.

[0167] Another embodiment of the present application provides an inkjet printing system, the inkjet printing system comprising:

[0168] substrate;

[0169] A print head device, comprising: a plurality of print heads and an execution unit; wherein the execution unit receives a control instruction sent by a control device and controls the plurality of print heads to execute the control instruction;

[0170] A control device is used to send control instructions to the nozzle device through the ultra-thin film forming method as described above.

[0171] In addition, it is understandable that the inkjet printing system also includes a motion platform, a nozzle moving mechanism, a power supply and other devices to ensure the normal operation of the inkjet printing system.

[0172] In the description of this application, it should be understood that the positive direction of "X" in the drawings represents the front, and correspondingly, the reverse direction of "X" represents the rear; the positive direction of "Y" represents the right, and correspondingly, the reverse direction of "Y" represents the left. The directions or positional relationships indicated by the terms "X", "Y", etc. are based on the directions or positional relationships shown in the drawings of the specification. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operate in a specific direction. Therefore, they should not be understood as limiting this application. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments or examples.

[0173] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0174] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0175] The foregoing description is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand and implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A method for forming an ultra-thin film, characterized in that, It includes the following steps: Obtain the area of the printing area of the substrate to be printed and the required printing film thickness, and obtain the total volume of the required functional liquid; Preset the volume of a single-drop liquid droplet as the single-drop volume, and obtain the total number of required prints according to the total amount of the functional liquid; Preset the number of prints in the X direction and the number of prints in the Y direction according to the total number of prints and the shape of the printing area; Preset the printing pitch in the X direction and the printing pitch in the Y direction according to the number of prints in the X direction, the number of prints in the Y direction, and the area of the printing area; Obtain the diffusion radius of a single-drop liquid droplet with a single-drop volume on the substrate, and correct the printing pitch in the X direction and the printing pitch in the Y direction according to the diffusion radius, so that adjacent single-drop liquid droplets on the substrate are in contact after diffusion; Perform a landing pattern planning according to the parameters of the number of prints in the X direction, the number of prints in the Y direction, the printing pitch in the X direction, and the printing pitch in the Y direction; Perform printing on the substrate by using a nozzle module according to the landing pattern planning; 2. The ultra-thin film forming method according to claim 1, characterized in that, After correcting the printing pitch in the X direction and the printing pitch in the Y direction according to the diffusion radius, it further includes a secondary correction of the printing pitch in the X direction and the printing pitch in the Y direction: Obtain the radius of the deviation area of the liquid droplet landing point; Make the printing pitch in the X direction and the printing pitch in the Y direction both within the range from the difference between twice the diffusion radius and twice the radius of the deviation area to twice the twice diffusion radius; 3. The ultra-thin film forming method according to claim 2, characterized in that, The obtaining of the radius of the deviation area of the liquid droplet landing point includes: Obtain the pitch in the Y direction between adjacent nozzles of the nozzle module to obtain the theoretical landing positions of the liquid droplets ejected by all nozzles when the nozzle module prints along a straight line in the Y direction; Make all nozzles of the nozzle module print in the Y direction to obtain the actual landing positions of the liquid droplets ejected by all nozzles when the nozzle module prints along a straight line in the Y direction; Correspond the actual landing position of the liquid droplet ejected by one nozzle with the theoretical landing position of the liquid droplet ejected by this nozzle, and judge the offset in the X direction and the offset in the Y direction between the actual landing position of the liquid droplets ejected by the remaining nozzles and the theoretical landing position of the liquid droplets ejected by the nozzles based on this; Calculate the radius of the deviation area according to the maximum value of the offset in the X direction and the maximum value of the offset in the Y direction; 4. The ultra-thin film forming method according to claim 1, wherein, The obtaining of the diffusion radius of a single-drop liquid droplet with a single-drop volume on the substrate includes: Obtain a plurality of substrates with different degrees of cleanliness; Make the nozzle module print liquid droplets with a variety of different volumes on a plurality of substrates with different degrees of cleanliness respectively, and measure the diffusion radii of all the liquid droplets; Establish a database of liquid droplet diffusion radii according to the diffusion radii of all the liquid droplets; Utilize the database of liquid droplet diffusion radii to obtain the liquid droplet diffusion radius corresponding to the cleanliness of the printed substrate and the volume of a single-drop liquid droplet; 5. The ultra-thin film forming method according to claim 2, characterized in that, The nozzle module includes multiple rows of nozzles extending in the Y direction, and multiple nozzles in different rows are staggered in the Y direction; The performing of printing on the substrate by using the nozzle module according to the landing pattern planning includes: Determine the positions of the deviation areas of all the liquid droplet landing points on the substrate according to the positions of all the liquid droplet landing points on the substrate and the radius of the deviation area; Obtain the relative position information between all the nozzles of the nozzle module and the deviation areas of all the liquid droplet landing points on the substrate; Determine the nozzles corresponding to the deviation areas of all the liquid droplet landing points; Make the nozzle module move in the X direction above the substrate to perform a scanning print on the substrate; 6. The ultra-thin film forming method according to claim 5, characterized in that The determining of the nozzles corresponding to the deviation areas of all the liquid droplet landing points includes: Judging one by one whether the Y-direction position information of multiple nozzles is within the range of the Y-direction position information of the deviation area of the liquid drop landing point; if so, the nozzle is the corresponding nozzle of the deviation area of the liquid drop landing point; If there are multiple corresponding nozzles for the deviation area of a liquid drop landing point, select the nozzle whose Y-direction position information is closest to the middle of the Y-direction position information range of the deviation area of the liquid drop landing point as the corresponding nozzle of the deviation area of the liquid drop landing point.

7. The ultra-thin film forming method according to claim 1, characterized in that The preset volume of a single-drop liquid drop is the single-drop volume, including: The volume of a single-drop liquid drop is 1 to 30 picoliters.

8. The ultra-thin film forming method according to claim 1, characterized in that In the printing on the substrate by using the nozzle head module according to the planned landing pattern, it further includes: Cleaning the substrate to make the contact angle of the surface of the substrate be 5 to 10 degrees.

9. An inkjet printing device, characterized in that, It includes a memory, a processor, and a computer program stored on the memory and executable on the processor. When the computer program is executed by the processor, it realizes the steps of the ultra-thin film forming method according to any one of claims 1 to 8.

10. An inkjet printing system, characterized in that, The inkjet printing system includes: A substrate; A nozzle head device, including: a plurality of printing nozzles, an execution unit; receiving a control instruction sent by a control device through the execution unit, and controlling the plurality of printing nozzles to execute the control instruction; A control device for sending a control instruction to the nozzle head device by using the ultra-thin film forming method according to claim 1.

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