TWI704016B - Ink coating device and ink coating method - Google Patents

Abstract

The present invention provides an ink coating device capable of shortening the processing time during ink coating. The moving mechanism moves one of the coating object and the inkjet head relative to the other so that the drop point of the ink on the coating object moves on the surface of the coating object. The control device controls the inkjet head and the moving mechanism. While moving one of the coating object and the inkjet head relative to the other, the ink drops on the edge area along the edge of the area to be coated to form an edge portion composed of ink in the edge area. In addition, after the edge portion is formed, one of the coating object and the inkjet head is moved relative to the other at a moving speed faster than the moving speed when the edge portion is formed, and the ink is applied to the edge surrounded by the edge portion. Internal area.

Description

Ink coating device and ink coating method

The invention relates to an ink coating device and an ink coating method.

The ink coating technology using inkjet heads is attracting attention in the formation of the resist pattern used in the etching mask during the manufacture of the printed circuit board and the formation of the solder resist of the printed circuit board. In the following Patent Document 1, a method is disclosed in which the area to be formed into a thin film is divided into a solid area and an edge area, and the pixels in the solid area are thinned to extract ink drop points. Thereby, the distribution density of the drop points in the solid area is reduced, but by increasing the volume of the droplets, the film in the solid area can be set to a desired thickness. (Prior technical literature) (Patent Document)

Patent Document 1: International Publication No. 2013/11775

(Problems to be solved by the present invention)

In the method of thinning the pixels in the solid area and extracting the ink drop points, the number of pixels constituting the image data will not decrease. Therefore, if you focus on all nozzle holes instead of one nozzle hole of the inkjet head, controlling the discharge frequency of the inkjet head will not decrease. Therefore, it is difficult to increase the scanning speed.

The object of the present invention is to provide an ink coating device and an ink coating method that can shorten the processing time of ink coating. (Means to solve the problem)

According to an aspect of the present invention, an ink coating device is provided, which has: The inkjet head ejects ink toward the coating object supported on the worktable; A moving mechanism for moving one of the coating object and the inkjet head relative to the other, so that the ink drop point on the coating object moves on the surface of the coating object; and The control device controls the inkjet head and the moving mechanism, The aforementioned control device controls the aforementioned inkjet head and the aforementioned moving mechanism, While moving one of the coating object and the inkjet head relative to the other, the ink is dropped on the edge area along the edge of the area to be coated to form an edge composed of ink in the edge area unit, After the edge portion is formed, one of the coating object and the inkjet head is moved relative to the other at a moving speed faster than the moving speed when the edge portion is formed, and the ink is applied to the edge. The internal area enclosed by the Ministry.

According to another aspect of the present invention, an ink coating method is provided, In the edge area of the surface of the coating object along the edge of the area to be coated with the ink, the ink drop point is moved while the ink droplets are dropped to form an edge portion composed of ink, After the edge portion is formed, in the inner region surrounded by the edge portion, the drop point is moved at a moving speed faster than the movement speed of the drop point when the edge portion is formed. The ink is applied to the aforementioned inner area.

According to another aspect of the present invention, an ink coating device is provided, which has: The inkjet head transforms ink droplets and ejects them toward the coating object supported on the worktable; A moving mechanism for moving one of the coating object and the inkjet head relative to the other, so that the ink drop point on the coating object moves on the surface of the coating object; and The control device controls the inkjet head and the moving mechanism, The aforementioned control device controls the aforementioned inkjet head and the aforementioned moving mechanism, While moving one of the object to be coated and the inkjet head relative to the other, the ink is dropped on a plurality of drop points along the edge of the area where the ink is to be applied. The edge of the composition, After forming the edge portion, while moving one of the coating object and the inkjet head relative to the other, the ink is dropped on a plurality of drop points in the inner region surrounded by the edge portion to remove the ink Coated on the aforementioned internal area, A plurality of dripping points of the edge region are periodically arranged along a first direction parallel to the relative movement direction of the coating target and the inkjet head and a second direction orthogonal to the first direction, and With a pitch wider than the pitch of the dripping points of the edge region, a plurality of dripping points of the inner region as a whole are periodically arranged in the first direction and the second direction.

According to another aspect of the present invention, an ink coating method is provided, In the edge area of the surface of the coating object along the edge of the area to be coated with the ink, the ink drop point is moved while the ink droplets are dropped to form an edge portion composed of ink, After the edge portion is formed, while moving the ink drop point in the inner region surrounded by the edge portion, droplets of ink are dropped to apply the ink to the inner region, A plurality of dripping points in the edge area are periodically arranged along the first direction and the second direction orthogonal to each other, and along the first direction and the second direction at a pitch wider than the pitch of the dripping points in the edge area A plurality of dripping points of the aforementioned inner region as a whole are periodically arranged in two directions. (Effect of Invention)

In order to apply ink to the edge area and the inner area in a separate process, the ink can be applied under conditions suitable for each area. For example, the ink can be applied to the edge area with a relatively high resolution, and the ink can be applied to the inner area with a relatively fast scanning speed.

1A to 3, the ink coating device based on the embodiment will be described. Fig. 1A is a schematic diagram of an ink coating device based on an embodiment. The stand 10 supports a table 15 via an XY stage 11 and a θ stage 12. The coating object 50 is supported on the support surface of the table 15. The coating object 50 is, for example, a substrate such as a printed circuit board. For example, the table 15 includes a vacuum chuck mechanism, and the coating target object 50 is vacuum sucked and fixed to the support surface. The supporting surface is, for example, parallel to the horizontal plane and faces upwards of the plumb bob.

The XY stage 11 moves the table 15 relative to the support 10 in two directions parallel to the supporting surface and orthogonal to each other. The θ stage 12 changes the posture of the rotation direction of the table 15 centered on the rotation axis perpendicular to the supporting surface.

Above the table 15, an inkjet head 16 is supported by a frame 17. A plurality of nozzle holes are provided on the surface of the inkjet head 16 facing the table 15. The circulation system 18 and the inkjet head 16 constitute an ink circulation path 19 and circulate the ink in the circulation path 19.

The inkjet head 16 converts ink droplets and discharges them toward the application target 50 supported by the table 15. The control device 40 stores image data defining the planar shape of the film pattern to be formed. The image data is, for example, data in a raster scan format in which a plurality of pixels are arranged in the row direction and the column direction. The control device 40 controls the XY stage 11 and the inkjet head 16 according to the image data, thereby forming a film pattern composed of ink on the upper surface of the coating object 50. In addition, the control device 40 controls the circulation system 18 and the θ stage 12.

FIG. 1B is a plan view of the workbench 15 of the ink coating device based on the embodiment. The coating object 50 is supported on the support surface of the table 15. The inkjet head 16 is supported above the coating object 50. A plurality of nozzle holes 20 are provided on each downwardly facing surface of the inkjet head 16. The inkjet head 16 converts ink droplets and ejects the ink droplets from the nozzle hole 20 toward the application target 50 supported by the table 15.

In addition, curing light sources 21 for curing ink are installed on both sides of the inkjet head 16 (upper and lower sides in FIG. 1B). For example, the ink is an ultraviolet curing type, and the curing light source 21 is an LED that emits ultraviolet light.

The x-direction and the y-direction are defined as the two directions parallel to and orthogonal to the support surface of the table 15 and the normal direction of the support surface is the z-direction. The plurality of nozzle holes 20 are arranged at equal intervals along the x direction. The control device 40 (FIG. 1A) moves the table 15 in the y direction (scanning direction), and discharges ink from the nozzle hole 20 at a timing based on the image data. Thereby, the ink can be dropped on a predetermined position (drop point) on the surface of the application target 50 supported by the table 15.

The time interval between the scanning speed of the table 15 and the ink discharge from the nozzle hole 20 is determined by the pixel pitch in the y direction of the image data. The minimum value of the ink ejection interval (ink ejection interval) is determined as the rated value of the inkjet head 16. The scanning speed of the table 15 is set by the rated value of the pixel pitch in the y direction and the ink discharge interval of the inkjet head 16.

The pixel pitch in the x direction depends on the pitch in the x direction of the nozzle hole 20. When the desired pixel pitch is narrower than the pitch of the nozzle hole 20, the inkjet head 16 is shifted in the x-direction by the pixel pitch to perform multiple scans. Thereby, regarding the x direction, ink can be applied at the pixel pitch set in the image data.

In FIG. 1A, the moving mechanism constituted by the XY stage 11 moves the coating target 50 relative to the inkjet head 16 to thereby move the drop point on the surface of the coating target 50. Contrary to this, the moving mechanism can also move the inkjet head 16 relative to the coating target 50, thereby moving the drop point. That is, it is sufficient to move one of the coating target 50 and the inkjet head 16 relative to the other so that the drop point moves on the surface of the coating target 50. The relative movement direction of the application target 50 and the inkjet head 16 corresponds to the scanning direction (y direction).

Fig. 2A is a plan view showing the area 51 to be coated with ink. An area 51 to be coated with ink is defined on the surface of the coating object 50. In FIG. 2A, the area 51 to be coated with ink is shaded. In this embodiment, the area 51 to be coated with ink is divided into an edge area 52 along the edge and an inner area 53 surrounded by the edge area 52. After the ink is applied to the edge area 52, the ink is applied to Internal area 53. The ink application conditions of the edge area 52 are different from the ink application conditions of the inner area 53.

FIG. 2B is a diagram showing the arrangement of the pixels 30 in the edge area 52 when the area 51 to be coated with ink is rectangular. In the example shown in FIG. 2B, the width of the edge region 52 is equivalent to the size of one pixel 30. Each center point of the pixel 30 corresponds to the ink drop point CE. The dropping points CE are periodically arranged at equal intervals in the x direction and the y direction. The pitch in the x direction of the drop point CE of the edge region 52 is represented by PEx, and the pitch in the y direction is represented by PEy. The pitch PEx is equal to the pitch PEy. In addition, a plurality of pixels 30 may be arranged along the width direction of the edge region 52 to enlarge the width of the edge region 52.

FIG. 2C is a diagram showing the arrangement of the pixels 31 in the inner area 53 when the area 51 to be coated with ink is rectangular. The pixels 31 of the inner area 53 are larger than the pixels 30 of the edge area 52. As an example, the size of one pixel 31 in the inner region 53 is equivalent to the size of four pixels 30 in the edge region 52. Each center point of the pixel 31 corresponds to the ink drop point CI. The dripping points CI are periodically arranged at equal intervals in the x direction and the y direction. The pitch in the x direction of the drop point CI of the inner region 53 is represented by PIx, and the pitch in the y direction is represented by PIy. The pitch PIx is equal to the pitch PIy. In addition, the pitch PIx and the pitch PIy are wider than the pitch PEx and the pitch PEy.

Next, referring to FIGS. 3 to 4C, the ink coating method based on the embodiment will be described. Fig. 3 is a flow chart of the ink coating method based on the embodiment. First, the application target object 50 is supported by the table 15 (step S1). Then, the control device 40 controls the XY stage 11 (FIG. 1A) to move the coating target 50 in the y direction, and at the same time controls the inkjet head 16 so that the ink drops on the drop point CE of the edge area 52 (FIG. 2A) (FIG. 2B) (Step S2). At this time, the application object 50 is irradiated with curing light from the curing light source 21 in advance. Therefore, the ink dropped on the coating object 50 hardens immediately after dropping.

FIG. 4A is a cross-sectional view of the coated object 50 forming the edge portion 55 after the ink dropped on the edge area 52 is cured, and the edge portion 55 is cut in the width direction. An edge portion 55 is formed in the edge region 52 of the coating object 50. The inner area 53 is not coated with ink.

After the edge portion 55 is formed, the control device 40 controls the XY stage 11 (FIG. 1A) to move the coating object 50 in the y direction, and at the same time controls the inkjet head 16 to drop ink on the inner area 53 (FIG. 2A). Drop point CI (FIG. 2C) (step S3). At this time, the coating target 50 is moved in the y direction at a speed faster than the movement speed (scanning speed) of the coating target 50 when the edge portion 55 is formed. The pitch PIy (FIG. 2C) of the drop point CI of the inner region 53 in the y direction is wider than the pitch PEy (FIG. 2B) of the drop point CE of the edge region 52. Therefore, even if the scanning speed is increased, the ink Drop at the drop point CI. When the ink is applied to the inner region 53, the curing light source 21 is not irradiated with the curing light.

FIG. 4B is a cross-sectional view of the coating object 50 after ink is applied to the inner region 53. Since the curing light is not irradiated, the ink dropped on the inner region 53 spreads in the in-plane direction, and the plurality of ink droplets are integrated with each other. As a result, the surface of the ink applied to the inner region 53 becomes flat, and a film 56 of liquid ink is formed. At this time, the edge portion 55 functions to block the outflow of liquid ink.

After the ink is applied to the inner region 53 while moving the coated object 50, the curing light is irradiated from the curing light source 21 (FIG. 1B) to the liquid ink film 56, thereby curing the ink in the inner region 53 ( Step S4).

4C is a cross-sectional view of the coating object 50 after the ink applied to the inner region 53 is cured. A film 57 having a flat surface is formed in the inner region 53.

Next, referring to FIGS. 2C and 5, the excellent effects of this embodiment will be described. FIG. 5 is a diagram showing the distribution of drop points CI when ink is applied to the inner region 53 (FIG. 2A) by a method based on a comparative example. The pitch of the pixels 31 in the y direction of the inner region 53 is equal to the pitch PEy of the pixels 30 in the edge region 52 in the y direction (FIG. 2B ). In the comparative example, the center point of one pixel 31 extracted from the four pixels 31 is referred to as the drop point CI.

The distribution density of the dropping point CI is the same in the case of the example (FIG. 2C) and the case of the comparative example (FIG. 5 ). However, in the case of the comparative example shown in FIG. 5, the minimum value of the pitch in the y direction of the dropping point CI is the same as the pitch PEy in the y direction of the dropping point CE of the edge region 52. Therefore, it is difficult to make the scanning speed when ink is applied to the inner region 53 faster than when the ink is applied to the edge region 52.

For example, in the example shown in FIG. 5, if one row is focused on, the pitch of the drop points CI in the scanning direction becomes twice the pitch PEy. However, as a whole of the inner region 53, the pitch in the scanning direction of the dropping points CI is equal to the pitch PEy. On the other hand, in this embodiment, the pitch PIy (FIG. 2C) in the y direction of the dripping point CI of the inner region 53 as a whole is wider than the pitch PEy of the dripping point CE of the edge region 52 in the y direction, for example, 2. Times. Here, "as a whole" means not only one column of the dropping point CI, but all the columns as objects.

Therefore, the scanning speed when the ink is applied to the inner area 53 can be made faster than the scanning speed when the ink is applied to the edge area 52. By increasing the scanning speed when the ink is applied to the inner region 53, the time required to apply the ink can be shortened.

Furthermore, in this embodiment, as shown in FIGS. 4B and 4C, the surface of the ink film formed in the inner region can be flattened. Therefore, the design of the film can be improved. When the film is used as an etching mask, the thickness of the film is uniform, and therefore, the reliability can be improved from the viewpoint of etching resistance compared to a film with unevenness formed on the surface.

Next, referring to Figs. 6A to 6E, other embodiments will be described. Hereinafter, a description of the structure common to the embodiment shown in FIGS. 1A to 4C will be omitted.

FIG. 6A is a diagram showing the arrangement of a plurality of pixels 30 in a part of the edge region 52. A plurality of pixels 30 are arranged in parallel, and each center of the pixel 30 corresponds to the drop point CE. FIG. 6B is a diagram showing the planar shape of the ink applied to the edge area 52. FIG. The ink dropped on the application target 50 spreads in a substantially circular shape, and the ink dropped on two adjacent dropping points CE is continuous with each other to form an edge portion 55.

FIG. 6C is a diagram showing the arrangement of a plurality of pixels 31 in a part of the internal region 53. The plurality of pixels 31 are two-dimensionally distributed along the x direction and the y direction. The pixel 31 is larger than the pixel 30 of the edge area 52 (FIG. 6A). Therefore, the pitch of the drop points CI of the inner area 53 is wider than the pitch of the drop points CE of the edge area 52.

FIG. 6D is a plan view showing the diffusion of the liquid applied to the inner region 53. The ink dropped on the application target 50 spreads in a substantially circular shape. The area where the ink diffuses is called the diffusion area 58. Depending on the distance between the drop points CI and the volume of the ink droplets, the ink diffusion area 58 may not completely cover the entire area of the inner area 53, which may cause coating omissions.

6E is a plan view showing the diffusion area of the ink when the ink is applied by the method of the present embodiment that can prevent the occurrence of coating omissions. In this embodiment, the volume of the ink droplet that falls on the drop point CI of the inner area 53 is greater than the volume of the ink droplet that falls on the drop point CE (FIG. 6A) of the edge area 52. The volume of the droplet is set so that the diffusion area 58 of the ink will completely cover the entire area of the inner area 53.

Next, the excellent effects of this embodiment will be described. In the present embodiment, by making the volume of the ink droplet at the drop point CI of the inner area 53 larger than the volume of the ink droplet at the drop point CE of the edge area 52, it is possible to suppress The internal area 53 causes an oversight of ink application. As a method of increasing the volume of the ink droplet that falls on the CI of the dripping point, the volume of a droplet can be increased, or it can be increased by increasing the number of droplets that fall on the CI of a dripping point. The total volume of large droplets.

Next, referring to FIGS. 7A to 8B, other embodiments are further described. Hereinafter, a description of the structure common to the embodiment shown in FIGS. 1A to 4 and 6E is omitted.

FIG. 7A is a diagram showing an example of the diffusion area 58 of the ink dropped on the drop point CI of the inner area 53. If the volume of the ink droplet dropped on the dropping point CI is increased, the diffusion area 58 will also become larger, and may extend beyond the edge portion 55 and spread to the outside.

FIG. 7B is a diagram showing an ink diffusion area 58 when the ink application device and ink application method according to this embodiment are used. In this embodiment, in order to prevent the diffusion area 58 of the ink dripping on the drop point CI of the inner area 53 from exceeding the edge portion 55 and spreading to the outside, compared with the structure of FIG. 7A, the outermost area of the inner area 53 The drop point CI is far away from the edge portion 55.

FIG. 8A is a diagram showing the distribution of pixels and drop points of the image data used in the embodiment shown in FIGS. 1A to 4 and 6E. The drop points CE of the edge region 52 are arranged at a pitch PE along the x direction and the y direction. The dropping points CI of the inner region 53 are arranged at a pitch PI along the x direction and the y direction. Gx represents the distance in the x direction between the drop point CI of the outermost periphery of the inner region 53 and the drop point CE of the edge region 52 adjacent to the drop point CI in the x direction. The pixel 31 located at the outermost periphery of the inner region 53 is in contact with the pixel 30 of the edge region 52, so the interval Gx is equal to the sum of 1/2 of the pitch PE and 1/2 of the pitch PI. The same applies to the y direction.

FIG. 8B is a diagram showing the distribution of pixels and drop points of the image data used in this embodiment. In this embodiment, the area occupied by the plurality of pixels 31 constituting the inner area 53 is reduced in the x direction and the y direction. Therefore, a gap 32 is formed between the pixel 31 located at the outermost periphery of the inner region 53 and the pixel 30 of the edge region 52. Therefore, the gap Gx is wider than the sum of 1/2 of the pitch PE and 1/2 of the pitch PI. The positions of the inner pixels 31 except for the outermost periphery are adjusted to be uniformly distributed in accordance with the displacement of the outermost pixels 31. The same applies to the y direction. The control device 40 controls the discharge timing of the ink and the nozzle hole 20 through which the ink is to be discharged based on the position of the adjusted pixel 31.

In this embodiment, by reducing the plurality of pixels 31 constituting the image data of the inner region 53 in the x direction and the y direction, the position of the drop point CI located at the outermost periphery of the inner region 53 is moved away from the edge region 52 The direction of displacement. As a result, as shown in FIG. 7B, it is possible to prevent the ink dropped on the inner region 53 from spreading to the outside of the edge portion 55.

In order to prevent the ink from spreading to the outside of the edge portion 55, it is preferable to set the interval Gx to be equal to or greater than the radius of a circular area where one droplet of ink dropped on the inner area 53 spreads. In addition, if the gap Gx is too large, an area where no ink is applied will be generated at the boundary between the edge area 52 and the inner area 53. The upper limit of the interval Gx is preferably set to such a degree that no uncoated ink area is generated.

Next, referring to FIGS. 9A and 9B, other embodiments are further described. Hereinafter, the description of the structure common to the embodiment shown in FIG. 8B is omitted.

FIG. 9A is a diagram showing the distribution of pixels of the image data used in this embodiment. In the embodiment shown in FIG. 8B, the area occupied by the plurality of pixels 31 constituting the inner area 53 is reduced in the two directions of the x direction and the y direction. In this embodiment, the area occupied by the plurality of pixels 31 constituting the inner area 53 is reduced in the x direction (direction orthogonal to the scanning direction), but not in the y direction (scanning direction). Therefore, the pixel 31 located at the outermost periphery of the inner region 53 is in contact with the pixel 30 of the edge region 52 adjacent to the pixel in the y direction.

FIG. 9B is a timing chart showing the timing when ink is discharged from the nozzle hole 20 (FIG. 1B ). Hereinafter, an example of scanning when the drop point moves in the positive direction of the y-axis in FIG. 9A and ink drops on 7 pixels 31 aligned in the y direction will be described. The pixels 31 at both ends of the seven pixels 31 are located at the outermost periphery of the inner region 53. Numbers 1 to 7 are added to the 7 pixels 31 in a row facing the positive direction of the y-axis. C(i) represents the center position of the i-th pixel 31, and CI(i) represents the drop point corresponding to the i-th pixel 31.

The upper timing chart of FIG. 9B shows the discharge time corresponding to the image data, and the lower timing chart shows the actual discharge time. The discharge time of the drop point CI(1) is made slower than the discharge time corresponding to the center position C(1) of the pixel 31. In addition, the discharge time of the dropping point CI(7) is made faster than the discharge time corresponding to the center position C(7) of the pixel 31. Regarding the discharge time of the inner dripping points CI(2) to CI(6) except for the dripping points CI(1) and CI(7) at both ends, it corresponds to the center position C(2) to C(6) The discharge time is staggered so that the time interval of the actual discharge time becomes constant.

In this way, by shifting the actual discharge time, the drop points CI(1) and CI(7) located at the outermost periphery of the inner region 53 can be moved away from the edge region 52. As a result, as in the embodiment shown in FIG. 8B, it is possible to prevent the ink dropped on the inner region 53 from spreading to the outside of the edge portion 55.

Next, referring to FIGS. 10A to 10D, other embodiments will be further described. Hereinafter, a description of the structure common to the embodiment shown in FIGS. 1A to 4C will be omitted.

FIG. 10A is a diagram showing the distribution of pixels 30 in the edge region 52 used in this embodiment. In the embodiment shown in FIG. 2B, the width of each side of the edge region 52 is the amount of one pixel 30. In this embodiment, a plurality of pixels 30, for example, three pixels 30, are arranged along the width direction of each side of the edge region 52. That is, a plurality of dripping points CE are arranged along the width direction of each side of the edge region 52. The three drop points CE arranged in the width direction are numbered from the outside to the inside. The inner area 53 is surrounded by the edge area 52.

Next, referring to FIGS. 10B to 10D, the order in which ink is dropped on the plurality of drop points CE arranged along the width direction of each side of the edge region 52 will be described.

10B is a cross-sectional view of the coating object 50 on the one-dot chain line 10B-10B of FIG. 10A, showing the state where the ink is dropped on the outermost drop point CE(1) of the edge region 52. The ink 61 dropped on the dropping point CE(1) spreads in the in-plane direction during the period before hardening, and reaches a position beyond the adjacent dropping point CE(2). Therefore, a convex portion of the ink centered on the position of the drop point CE(1) is formed. The adjacent drop point CE (2) is located at a position corresponding to the slope of the convex portion formed by the ink 61.

FIG. 10C shows a state when the ink 62 is dropped on the second drop point CE(2) from the outside of the edge region 52. The ink dropped on the dropping point CE(2) flows along the slope of the convex portion formed by the ink 61 just discharged toward the inner region 53 and reaches a position beyond the adjacent dropping point CE(3).

FIG. 10D shows a state when the ink 63 is dropped on the innermost drop point CE(3) of the edge area 52. The ink dropped on the dropping point CE(3) flows toward the inner area 53 along the slope of the ink 62 that has just been discharged and hardened. The edge portion 55 is formed by hardening the inks 61, 62, and 63 dropped on the drop points CE(1) to CE(3).

Next, the excellent effects of this embodiment will be described. In this embodiment, with respect to the width direction of each side of the edge region 52, the ink is sequentially dropped from the outer dropping point CE(1) to the inner dropping point CE(3). The subsequently dripped ink flows along the slope of the previously dripped and hardened ink toward the inner region 53 (FIG. 10A). Therefore, the slope of the inner region 53 side of the edge portion 55 (FIG. 10D) is more inclined than the outer slope. The degree is gentle. In other words, the inclination of the slope on the outer side of the edge portion 55 can be made steep.

In FIGS. 10B to 10D, the side parallel to the x direction (the side orthogonal to the scanning direction) will be described. Regarding the side parallel to the y direction (scanning direction), it is also preferable to sequentially drop the ink on a plurality of drop points CE arranged in the width direction from the outside to the inside. For example, when the ink is dropped on the drop point CE of the edge area 52 by multiple scans, the ink is dropped on the outermost drop point CE in the first scan, and the ink is sequentially ordered by subsequent scans. The drop point CE that drops on the inner side is better.

Next, referring to FIGS. 11A and 11B, other embodiments are further described. Hereinafter, a description of the structure common to the embodiment shown in FIGS. 1A to 4C will be omitted. In the embodiment shown in FIGS. 1A to 4C, in order to apply ink to the edge area 52 and the inner area 53 (FIG. 2A), a common inkjet head 16 (FIG. 1B) is used. In this embodiment, an inkjet head for applying ink to the edge area and an inkjet head for applying ink to the inner area are provided.

FIG. 11A is a bottom view of the inkjet head 16E for the edge area, and FIG. 11B is a bottom view of the inkjet head 16I for the inner area. The bottom surface of the edge area inkjet head 16E is provided with a plurality of nozzle holes 20E arranged in the x direction, and the bottom surface of the inner area inkjet head 16I is provided with a plurality of nozzle holes 20I arranged in the x direction. The pitch of the nozzle holes 20I in the x direction is wider than the pitch of the nozzle holes 20E in the x direction. In addition, the volume of ink droplets discharged by the inkjet head 16I for the inner area is larger than the volume of ink droplets discharged by the inkjet head 16E for the edge area.

Curing light sources 21E are respectively arranged on both sides of the edge area inkjet head 16E. The curing light source 21I is respectively arranged on both sides of the inkjet head 16I for the inner area. The curing light sources 21E and 21I irradiate the coating object 50 with curing light for curing the ink.

The distance WIy between the nozzle hole 20I of the inkjet head 16I for inner area and the curing light source 21I in the y direction is wider than the distance WEy between the nozzle hole 20E of the inkjet head 16E for edge area and the curing light source 21E in the y direction.

In the embodiment shown in FIG. 3, after scanning to apply ink to the inner region 53 in step S3, the ink in the inner region 53 is hardened in step S4. In the present embodiment, when the inkjet head 16I for the inner area is used to scan the ink to be applied to the inner area 53, the curing light is irradiated from the curing light source 21I to the application target 50.

Next, the excellent effects of this embodiment will be described. The interval WIy is wider than the interval WEy, and therefore the time from the ink dripping to the inner region 53 until hardening is longer than the time from ink dripping to the edge region 52 until hardening. Thereby, the ink dropped on the inner region 53 can be diffused, the upper surface of the ink film becomes substantially flat, and then the ink is cured. As a result, as in the embodiment shown in FIGS. 4A to 4C, the surface of the ink film 57 in the inner region 53 can be flattened. In this embodiment, there is no need to separately perform the treatment for hardening the ink, so the treatment time can be shortened.

The volume of the ink droplets discharged from the inkjet head 16I for the inner area is larger than the volume of ink droplets discharged from the inkjet head 16E for the edge area, so that the leakage of the inner area 53 (FIG. 2A) can be prevented.

The foregoing embodiments are examples, and it is of course possible to perform partial replacement or combination of the structures shown in different embodiments. Regarding the same effects based on the same structure of a plurality of embodiments, they are not mentioned in turn in each embodiment. In addition, the present invention is not limited to the above-mentioned embodiment. It should be clear to those skilled in the art that, for example, various changes, improvements, and combinations can be made.

10‧‧‧Support 11‧‧‧XY stage 12‧‧‧θ stage 15‧‧‧Working table 16‧‧‧Inkjet head 16E‧‧‧Inkjet head for edge area 16I‧‧‧Inkjet head for internal area 17‧‧‧Frame 18‧‧‧Circulation system 19‧‧‧Circulation path 20, 20E, 20I‧‧‧Nozzle hole 21, 21E, 21I‧‧‧Light source for curing 30‧‧‧Pixels in the edge area 31‧‧‧Pixels in the inner area 32‧‧‧Gap 40‧‧‧Control device 50‧‧‧Coating object 51‧‧‧The area to be coated with ink 52‧‧‧Edge area 53‧‧‧Internal area 55‧‧‧Edge 56‧‧‧The liquid ink film applied to the inner area 57‧‧‧Film of hardened ink 58‧‧‧Ink diffusion area 61, 62, 63‧‧‧Ink dripping on the edge area

FIG. 1A is a schematic view of the ink coating device based on the embodiment, and FIG. 1B is a plan view of the workbench of the ink coating device based on the embodiment. Figure 2A is a plan view of the area to be coated with ink, Figure 2B is a diagram showing the arrangement of pixels in the edge area when the area to be coated with ink is rectangular, and Figure 2C is a diagram showing the area to be coated with ink is rectangular The layout of the pixels in the inner area. Fig. 3 is a flow chart of the ink coating method based on the embodiment. Fig. 4A is a cross-sectional view of the coated object formed with the edge portion, cutting the edge portion in the width direction, Fig. 4B is a cross-sectional view of the coated object after ink is applied to the inner area, and Fig. 4C is the coated Cross-sectional view of the object to be coated after the ink in the inner area has cured. FIG. 5 is a diagram showing the distribution of dripping points when ink is applied to the inner region (FIG. 2A) by the method based on the comparative example. Fig. 6A is a diagram showing the arrangement of a plurality of pixels in the edge area, Fig. 6B is a diagram showing the plane shape of the ink applied to the edge area, Fig. 6C is a diagram showing the arrangement of a plurality of pixels in the inner area, and Fig. 6D is 6E is a plan view showing the diffusion area of the ink when the ink is applied by the method based on the embodiment capable of preventing the occurrence of coating omissions. FIG. 7A is a diagram showing an example of the diffusion area of the ink at the drop point of the inner region, and FIG. 7B is a diagram showing the diffusion area of the ink when the ink application device and ink application method based on the embodiment are used. 8A is a diagram showing the distribution of pixels and drop points of the image data used in the embodiment shown in FIGS. 1A to 4 and 6E, and FIG. 8B shows the pixels of the image data used in other embodiments And the distribution of the drop points. FIG. 9A is a diagram showing the distribution of pixels of the image data used in the embodiment, and FIG. 9B is a timing diagram showing the timing when ink is discharged from the nozzle hole. 10A is a diagram showing the distribution of pixels in the edge area used in the embodiment, and FIG. 10B is a cross-sectional view of the coating object on the one-dot chain line 10B-10B of FIG. 10A, and shows that the ink drops on the edge Fig. 10C shows a cross-sectional view of the state when the ink is dropped on the second dropping point from the outside of the edge area, and Fig. 10D shows the ink drop on the edge. A cross-sectional view of the state of the drip point at the innermost point of the area. FIG. 11A is a bottom view of the inkjet head for the edge area, and FIG. 11B is a bottom view of the inkjet head for the inner area.

Claims (6)

An ink coating device comprising: an inkjet head that ejects ink toward an object to be coated on a worktable; and a moving mechanism that moves one of the object to be coated and the inkjet head relative to the other to Moving the drop point of the ink on the coating object on the surface of the coating object; and a control device that controls the inkjet head and the moving mechanism, and the control device controls the inkjet head and the moving mechanism , While moving one of the coating object and the inkjet head relative to the other, the ink is dropped on the edge area along the edge of the area to be coated to form an ink composition in the edge area At the edge portion, after the edge portion is formed, one of the coating object and the inkjet head is moved relative to the other at a moving speed faster than the moving speed when the edge portion is formed, and the ink is applied to The inner area surrounded by the aforementioned edge. The ink application device described in claim 1, wherein the control device is along a first direction parallel to the relative movement direction of the coating object and the inkjet head, and is aligned with the first direction In the second direction, a plurality of dripping points in the edge area are periodically arranged, and the inner portion is periodically arranged in the first direction and the second direction at a pitch wider than the pitch of the dripping points in the edge area Plural drop points in the area. The ink application device according to the second item of the patent application, wherein the control device adjusts the first drop point of the outermost periphery of the inner region and the drop point of the edge region closest to the drop point. The directional interval is set to be wider than 1/2 of the sum of the pitch of the dripping points arranged in the first direction of the inner region and the pitch of the dripping points arranged in the first direction of the edge region. The ink application device described in claim 3, wherein the control device adjusts the position of the outermost pixel of the image data composed of a plurality of pixels that defines the shape of the inner region to move away from the edge The direction displacement of the area adjusts the positions of a plurality of inner pixels based on the displacement of the outermost pixels, and controls the discharge timing of the ink based on the adjusted pixel positions. The ink application device according to the third item of the scope of patent application, wherein the control device shifts the actual discharge time from the ink discharge time based on the image data defining the shape of the inner region, so as to follow the first The distance between the drop points at both ends of the drop points of the inner region arranged in the direction and the edge area is set to be wider than the distance between the drop points based on the image data and the edge area. An ink coating method, on the surface of the coated object, along the edge of the area to be coated with ink The edge area of the edge moves the ink drop point while dropping ink droplets to form an edge portion composed of ink. After the edge portion is formed, the inner area surrounded by the edge portion makes the drop point While moving at a moving speed faster than the moving speed of the drop point when the edge portion is formed, droplets of ink are dropped to apply the ink to the inner region.

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