Coating apparatus and coating method

Abstract

To provide a coating applicator and a coating method capable of preventing a time required for applying non-Newtonian fluid from becoming long.SOLUTION: A coating applicator includes a coating needle 24 for applying a coating material whose viscosity changes due to shearing to an object, a drive part 90 for lifting the coating needle 24, and a control device for moving the coating needle so that the coating material is sheared at a shear rate according to the kind of the coating material, and to a target coating amount or a target coating diameter, by controlling the drive part 90.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a coating apparatus and a coating method, and more particularly to a coating apparatus and a coating method for applying a liquid material to a workpiece using a coating needle.

Background Art

[0002] In recent years, printed electronics technology for forming fine circuits such as RFID (Radio Frequency Identifier) tags by printing (coating) has been rapidly developing. As methods for forming fine circuit patterns or electrode patterns, an inkjet method, a dispenser method, etc. are common, but a method using a coating needle has attracted attention in that fine coating can be performed using materials with a wide range of viscosities.

[0003] Patent Document 1 describes a method for performing fine coating of a liquid material using a coating unit. Such a coating unit is intended to correct defects in fine patterns and can perform fine coating using coating materials with a wide range of viscosities. During the coating operation, one coating needle is projected from a through-hole formed in the bottom of a coating material container that holds the coating material. The coating needle performs coating by bringing the coating material adhering to its tip into contact with the workpiece.

[0004] Patent Document 2 describes a method for coating a non-Newtonian fluid using a coating needle method. Specifically, Patent Document 2 describes that when performing quantitative coating with respect to the viscosity change of an adhesive that is a non-Newtonian fluid, the depth of immersion of the coating pin is changed. Patent Document 2 describes that when increasing or decreasing the coating amount, the time the coating needle is immersed in the adhesive, the time the coating needle performs transfer coating on the adherend, or the diameter of the coating needle is changed. Further, Patent Document 2 describes measuring the initial viscosity and the viscosity change over time of the adhesive and reflecting them in the immersion depth, transfer time, and immersion time of the coating needle.

Prior Art Documents

Patent Documents

[0005] [Patent Document 1] Japanese Patent Publication No. 2007-268353 [Patent Document 2] Japanese Patent Application Publication No. 4-35857 [Overview of the project] [Problems that the invention aims to solve]

[0006] Patent Document 2 discloses a method for adjusting the amount of a non-Newtonian fluid applied using a coating needle, but this method includes a wiping step for the adjustment coating needle, which increases the working time. Furthermore, controlling the immersion time and transfer time may further increase the application time. This can lead to surface drying in the case of adhesives. In addition, changing the diameter of the coating needle requires setup changes.

[0007] Therefore, an object of the present invention is to provide a coating apparatus and a coating method that can reduce the time required to coat a non-Newtonian fluid. [Means for solving the problem]

[0008] The coating apparatus of the present invention comprises a coating needle for applying a coating material whose viscosity changes due to shearing to an object, a drive unit for raising and lowering the coating needle, and a control unit that controls the drive unit to move the coating needle so that the coating material is sheared at a shearing rate corresponding to the type of coating material and the target coating amount or target coating diameter.

[0009] Preferably, the device includes a container that holds the coating material and has a through hole in the bottom facing the object through which a coating needle protrudes. The control device controls the drive unit to move the coating needle so that the coating material is sheared at a shear rate as the coating needle passes through the through hole.

[0010] Preferably, the control device determines the vertical downward movement speed of the coating needle based on the type of coating material and the target coating amount or target coating diameter, and controls the speed at which the coating needle passes through the through hole to the determined movement speed.

[0011] Preferably, the control device determines the vertical downward movement speed of the coating needle based on the type of coating material, the target coating amount or target coating diameter, and the distance between the coating needle and the outer wall of the through-hole when the coating needle protrudes from the through-hole, and controls the speed at which the coating needle passes through the through-hole to the determined movement speed.

[0012] Preferably, the control device has a table that defines the type of coating material, the target coating amount or target coating diameter, and the travel speed for each interval, and determines the travel speed by referring to the table.

[0013] Preferably, the coating material is one of a pseudoplastic fluid, a dilatant fluid, or a Bingham fluid.

[0014] Preferably, the table is configured such that the distance between the coating needle and the outer wall of the through-hole is the same, and in the case of a pseudoplastic fluid, the movement speed decreases as the target coating amount increases.

[0015] Preferably, the table is configured such that the distance between the coating needle and the outer wall of the through-hole is the same, and when the type of coating material is a dilatant fluid, the movement speed increases as the target coating amount increases.

[0016] Preferably, the table is configured such that the distance between the coating needle and the outer wall of the through-hole is the same, and when the type of coating material is a Bingham fluid, the movement speed decreases as the target coating amount increases when the target coating amount is less than or equal to a predetermined value, and remains constant regardless of the target coating amount when the target coating amount exceeds a predetermined value.

[0017] Preferably, the table is configured such that, when the type of coating material and the target coating amount are the same, the greater the distance between the coating needle and the outer wall of the through-hole, the smaller the moving speed.

[0018] Preferably, the coating material is a cell-containing solution.

[0019] Preferably, the table is determined such that when the distance between the coating needle and the outer wall of the through hole is the same, the moving speed becomes smaller as the target coating amount becomes larger.

[0020] The present invention relates to a coating method of a coating apparatus including a coating needle for coating a coating material whose viscosity changes by shearing on an object, and a container that holds the coating material and has a through hole that projects the coating needle at the bottom facing the object. The method includes determining a downward moving speed of the coating needle in the vertical direction based on the type of the coating material, the target coating amount or the target coating diameter, and the distance between the coating needle and the outer wall of the through hole when the coating needle projects through the through hole, and controlling the speed to the determined moving speed when the coating needle passes through the through hole.

Effect of the Invention

[0021] According to the present invention, it is possible to prevent the time required to coat a non-Newtonian fluid from becoming long.

Brief Description of the Drawings

[0022] [Figure 1] It is a schematic diagram of the coating apparatus of the embodiment. [Figure 2] It is a schematic diagram showing the coating mechanism 4 of the coating apparatus shown in FIG. 1. [Figure 3] It is a schematic diagram for explaining the cam member of the coating mechanism 4 shown in FIG. 2. [Figure 4] It is a schematic diagram for explaining the operation of the coating needle 24 in the coating mechanism 4 shown in FIG. 2. [Figure 5] It is a graph for explaining the operation of the coating needle 24 in the coating mechanism 4 shown in FIG. 2. [Figure 6] It is a diagram showing an outline of the relationship between the shear force and the shear viscosity for each type of fluid. [Figure 7]This figure shows the measurement results of shear viscosity as a function of shear rate when the coating material is an aqueous solution of a polymer. [Figure 8] This figure shows the measurement results of the thickness of the droplet attached to the tip of the coating needle 24 as a function of the movement speed of the coating needle 24, when the coating material is an aqueous solution of a polymer. [Figure 9] (a) is a diagram showing the coated material 70 when the movement speed of the coating needle 24 is high, when the coated material is an aqueous solution of a polymer. (b) is a diagram showing the coated material 70 when the movement speed of the coating needle 24 is about medium, when the coated material is an aqueous solution of a polymer. (c) is a diagram showing the coated material 70 when the movement speed of the coating needle 24 is low, when the coated material is an aqueous solution of a polymer. [Figure 10] This figure shows an example of a speed table in the first embodiment. [Figure 11] This is a flowchart illustrating the procedure for controlling the drive of the coating needle 24 in the first embodiment. [Figure 12] This diagram shows the state of the coating needle 24 when it protrudes from the through hole 72. [Figure 13] This figure shows an example of a speed table according to the second embodiment. [Figure 14] This is a flowchart illustrating the procedure for controlling the drive of the coating needle 24 in the second embodiment. [Figure 15] This figure shows an example of a speed table for Modification Example 1. [Figure 16] This figure shows an example of a speed table for variation 2. [Figure 17] This figure shows the measurement results of the coating diameter against the coating speed when the coating material is a cell-containing solution made by adding cells to a hyaluronic acid solution. [Modes for carrying out the invention]

[0023] Embodiments of the present invention will be described below with reference to the drawings. In the following drawings, identical or corresponding parts are given the same reference numerals, and their descriptions will not be repeated.

[0024] [First Embodiment] (Overall configuration of the coating apparatus) Figure 1 is a schematic diagram of a coating apparatus according to an embodiment. Referring to Figure 1, the coating apparatus comprises a processing chamber, a Y-axis table 2, an X-axis table 1, a Z-axis table 3, a coating mechanism 4, an observation optical system 6, a CCD camera 7 connected to the observation optical system 6, and a control device 80. The control device 80 includes a monitor 9, a control computer 10, and an operation panel 8.

[0025] Inside the processing chamber, a Y-axis table 2 is installed on the bottom of the chamber. The Y-axis table 2 is configured to be movable in the Y-axis direction. Specifically, a guide part is installed on the underside of the Y-axis table 2. The guide part is slidably connected to a guide rail installed on the bottom of the processing chamber. A ball screw is connected to the underside of the Y-axis table 2. By operating the ball screw with a drive member such as a motor, the Y-axis table 2 is configured to be movable along the guide rail (in the Y-axis direction). The upper surface of the Y-axis table 2 forms a mounting surface on which the substrate 5, which is the material to be processed, is mounted.

[0026] An X-axis table 1 is placed on a Y-axis table 2. The X-axis table 1 is positioned on a structure that straddles the Y-axis table 2 in the X-axis direction. A movable body to which a Z-axis table 3 is connected is mounted on the X-axis table 1 so as to be movable in the X-axis direction. The movable body is configured to be movable in the X-axis direction, for example, using a ball screw. The X-axis table 1 is fixed to the bottom surface of the processing chamber via the above structure. Therefore, the Y-axis table 2 is configured to be movable in the Y-axis direction relative to the X-axis table 1.

[0027] A Z-axis table 3 is installed on the mobile body connected to the X-axis table 1, as described above. An observation optical system 6 and a coating mechanism 4 are connected to the Z-axis table 3. The observation optical system 6 is for observing the coating position on the substrate 5 to be coated. The CCD camera 7 converts the observed image into an electrical signal. The Z-axis table 3 holds these observation optical system 6 and coating mechanism 4 so that they can move in the Z-axis direction.

[0028] A control computer 10 and operation panel 8 for controlling the Y-axis table 2, X-axis table 1, Z-axis table 3, observation optical system 6, and coating mechanism 4, as well as a monitor 9 attached to the control computer, are installed outside the processing room. The monitor 9 displays image data converted by the CCD camera 7 mentioned above, and output data from the control computer 10. The operation panel 8 is used to input commands to the control computer 10. The control computer 10 is equipped with a CPU (Central Processing Unit) and memory. The CPU can perform various controls by executing programs stored in memory.

[0029] (Configuration of coating mechanism 4) The coating mechanism 4 described above will be explained in more detail with reference to Figures 2 and 3. The coating mechanism 4 fixed to the Z-axis table 3 shown in Figure 1 comprises a servo motor 41, a cam 43, a bearing 44, a cam connecting plate 45, a movable part 46, a coating needle holder 20, a coating needle 24 held in the coating needle holder 20, a coating material container 21, and a drive unit 90. The drive unit 90 comprises the servo motor 41, the cam 43, the bearing 44, the cam connecting plate 45, and the movable part 46.

[0030] The servo motor 41 is installed so that its rotation axis extends in the direction along the Z-axis direction shown in Figure 1. A cam 43 is connected to the rotation axis of the servo motor 41. The cam 43 is configured to rotate about the rotation axis of the servo motor 41.

[0031] The cam 43 includes a central part connected to the rotation axis of the servo motor 41 and a flange part connected to one end of the central part. As shown in Figure 3(A), the upper surface of the flange part (the surface on the servo motor 41 side) is the cam surface 61. The cam surface 61 is formed in an annular shape along the outer circumference of the central part and is also formed in a slope shape so that the distance from the bottom surface of the flange part varies. Specifically, as shown in Figure 3(B), the cam surface 61 includes an upper flat region 62 where the distance from the bottom surface of the flange part is greatest, a lower flat region 63 which is spaced apart from the upper flat region 62 and where the distance from the bottom surface of the flange part is smallest, and a slope part connecting the upper flat region 62 and the lower flat region 63. Here, Figure 3(B) is a side view of the flange part including the cam surface 61 which is arranged in an annular shape surrounding the central part.

[0032] A bearing 44 is positioned so as to be in contact with the cam surface 61 of the cam 43. As shown in Figure 2(A), the bearing 44 is positioned in a specific direction (to the right of the servo motor 41) when viewed from the cam 43, and maintains contact with the cam surface 61 when the cam 43 rotates due to the rotation of the servo motor 41's rotation axis. A cam connecting plate 45 is connected to this bearing 44. One end of the cam connecting plate 45 connected to the bearing 44 and the other end opposite to it are fixed to a movable part 46. A coating needle holder fixing part 47 and a coating needle holder housing part 48 are connected to the movable part 46. The coating needle holder 20 is housed in this coating needle holder housing part 48.

[0033] The coating needle holder 20 includes a coating needle 24. The coating needle 24 is positioned to protrude from the coating needle holder 20 on the lower surface of the coating needle holder 20 (the lower side opposite to the side where the servo motor 41 is located). A coating material container 21 is positioned below the coating needle holder 20. The coating needle 24 is held in an inserted state within the coating material container 21.

[0034] A fixing pin 52 is installed on the movable part 46. The other fixing pin 51 is installed on the frame that holds the servo motor 41. A spring 50 is installed so as to connect these fixing pins 51 and 52. Due to the spring 50, the movable part 46 is subjected to a tensile force toward the coating material container 21. This tensile force from the spring 50 acts on the bearing 44 via the movable part 46 and the cam connecting plate 45. Due to the tensile force of the spring 50, the bearing 44 is maintained in a state of being pressed against the cam surface 61 of the cam 43.

[0035] The movable part 46, the coating needle holder fixing part 47, and the coating needle holder storage part 48 are connected to a linear guide 49 installed on the frame. The linear guide 49 is positioned to extend in the Z-axis direction. Therefore, the movable part 46, the coating needle holder fixing part 47, and the coating needle holder storage part 48 are configured to be movable along the Z-axis direction.

[0036] (Operation of the coating mechanism) Next, the operation of the coating mechanism 4 described above will be explained. In the coating mechanism 4 described above, the cam 43 is rotated by driving the servo motor 41, which rotates the rotation axis of the servo motor 41. As a result, the height of the cam surface 61 of the cam 43 changes in the Z-axis direction, so the position of the bearing 44 in the Z-axis direction, which is in contact with the cam surface 61 on the right side of the cam 43 in Figure 2(A), also changes in the Z-axis direction according to the rotation of the drive axis of the servo motor 41. In accordance with the change in the position of the bearing 44 in the Z-axis direction, the movable part 46, the coating needle holder fixing part 47, and the coating needle holder housing part 48 move in the Z-axis direction. As a result, the coating needle holder 20 held in the coating needle holder housing part 48 also moves in the Z-axis direction, so the position of the coating needle 24 installed in the coating needle holder 20 in the Z-axis direction can be changed.

[0037] Specifically, referring to Figures 3 and 4, when the bearing 44 is in contact with the upper flat region 62 of the cam surface 61 of the cam 43, the coating needle 24 will be positioned at its upper end (the position closest to the servo motor 41), as shown in Figure 4(A). At this time, the tip of the coating needle 24 is immersed in the coating material 70 held in the coating material container 21. The coating material container 21 has a through hole 72 at its bottom facing the substrate 5, through which the coating needle 24 protrudes.

[0038] Next, as the servo motor 41 rotates the rotation shaft, the cam 43 rotates, and when the bearing 44 reaches a position where the lower end flat region 63 of the cam surface 61 contacts the bearing 44, as shown in Figure 4(B), the coating needle 24 passes through the through hole 72 formed in the bottom of the coating material container 21 and protrudes downward from the bottom surface of the coating material container 21. At this time, a portion of the coating material 70 adheres to the surface of the coating needle 24 that protrudes from the bottom surface of the coating material container 21. As the Z-axis table 3 (see Figure 1) moves the coating mechanism 4 toward the substrate 5, the tip of the coating needle 24 comes into contact with the surface of the substrate 5, and the coating material 70 can be applied to the surface of the substrate 5. Note that the Z-axis table 3 may be moved first and then the servo motor 41 may be driven, or the operation of the Z-axis table 3 and the servo motor 41 may be performed almost simultaneously.

[0039] In the coating mechanism 4, the rotational motion of the servo motor 41 can be converted into motion (up and down) of the coating needle 24 in the Z-axis direction. With this configuration, the coating needle 24 can be moved quickly and accurately in the Z-axis direction.

[0040] In order to further improve the accuracy of the coating process of the coating material 70 by the coating needle 24, the operating speed of the coating needle 24 is controlled as follows.

[0041] Specifically, as shown in Figure 5, the movement speed of the coating needle 24 is changed according to the position of the coating needle 24. Here, the horizontal axis in Figure 5 represents the tip position of the coating needle 24, and the vertical axis represents the movement speed of the coating needle.

[0042] As shown in Figure 4(A), when the coating needle 24 is at its upper end position (position P1 in Figure 5), driving the servo motor 41 causes the cam 43 to rotate, and the bearing 44 comes into contact with an area of ​​the cam surface 61 other than the upper end flat area 62. As a result, the coating needle 24 moves toward the substrate 5. Then, the movement speed of the coating needle 24 is increased until it reaches position P2 on the horizontal axis in Figure 5. Specifically, the movement speed of the coating needle 24 can be increased by increasing the rotation speed of the servo motor 41.

[0043] Then, after reaching a predetermined movement speed V2 (after reaching position P2), the coating needle 24 is moved while maintaining the predetermined movement speed V2. This can be achieved by keeping the rotation speed of the servo motor 41 constant. When it reaches position P3 in Figure 5, the movement speed of the coating needle 24 is reduced. Specifically, the rotation speed of the servo motor 41 is gradually reduced. As a result, the movement speed of the coating needle 24 is sufficiently reduced until it reaches a predetermined position P4 before the bearing 44 reaches the lower end flat region 63 (see Figure 3).

[0044] Then, the coating needle 24 is moved at a predetermined low speed V1 from position P4 in Figure 5 until it reaches the lower end position (position P5) shown in Figure 4(B). In this case as well, the rotation speed of the servo motor 41 is maintained at a predetermined speed. By performing this control, the movement speed of the coating needle 24 is sufficiently small when the coating needle 24 contacts the substrate 5, so that the impact when the coating needle 24 contacts the substrate 5 can be reduced, and the positional accuracy when the coating needle 24 applies the coating material 70 to the surface of the substrate 5 can be prevented from degrading due to this impact.

[0045] Liquids that can be used as coating materials can be broadly classified into Newtonian fluids and non-Newtonian fluids. Non-Newtonian fluids are classified into pseudoplastic fluids, Bingham fluids, and dilatant fluids. Newtonian fluids include water and silicone oil. Pseudoplastic fluids include ketchup, polymeric liquids, and paints. Bingham fluids include toothpaste and butter. Dilatant fluids include cornstarch dissolved in water and sandy beaches.

[0046] Figure 6 shows a schematic diagram illustrating the relationship between shear force and shear viscosity for different types of fluids. The horizontal axis represents the shear force applied to the fluid, and the vertical axis represents the shear viscosity of the fluid. Note that even among fluids of the same type, the specific magnitude of the shear density can differ. Figure 6 shows the shear viscosity of representative fluids for each type of fluid.

[0047] As shown in Figure 6, the shear viscosity of a Newtonian fluid does not change even when the shear force changes. In a pseudoplastic fluid, the shear viscosity decreases as the shear force increases. A Bingham fluid does not exhibit fluidity until the shear force exceeds a certain value. In a dilatant fluid, the shear viscosity increases as the shear force increases.

[0048] The inventors of this application investigated the change in shear viscosity due to a change in shear rate using an aqueous solution of a polymer, which is a typical example of a pseudoplastic fluid.

[0049] The measurement conditions were set as follows: The polymer was dissolved in water to prepare solutions with concentrations of 0, 0.5, 1, 1.2, 1.5, and 2 (w / v%). The temperature was maintained at 25 degrees Celsius, and the change in shear viscosity was measured in response to the change in shear rate of each prepared solution. The measurement was repeated three times, and the average value of the measured values ​​was calculated.

[0050] Figure 7 shows the measurement results of shear viscosity as a function of shear rate when the coating material is an aqueous solution of a polymer. As shown in Figure 7, when the coating material is an aqueous solution of a polymer, the shear viscosity decreases as the shear rate increases. Also, the shear viscosity of the solution increases as the concentration of the polymer solution increases.

[0051] Furthermore, the inventor of this application conducted the following coating tests.

[0052] The measurement conditions were set as follows: A polymer was dissolved in water to prepare solutions with concentrations of 0, 0.5, 1, 1.2, and 1.5 (w / v%). Each of the prepared solutions was placed in a coating material container, and the movement speed of the coating needle 24 was varied to make the needle protrude. The thickness of the droplet attached to the tip of the coating needle 24 was measured. The amount of adhesion can be indirectly represented by the thickness. The measurement was repeated three times, and the average value of the measured values ​​was calculated.

[0053] Figure 8 shows the measurement results of the thickness of the droplet attached to the tip of the coating needle 24 as a function of the movement speed of the coating needle 24 when the coating material is an aqueous solution of a polymer. The movement speed of the coating needle 24 corresponds to the movement speed V2 in Figure 5, and is the vertical downward speed of the coating needle 24 when the tip portion of the coating needle 24 protrudes from the through hole 72.

[0054] As shown in Figure 8, when the coating material is an aqueous solution of a polymer, the amount of liquid droplets adhering to the tip of the coating needle 24 decreases as the movement speed of the coating needle 24 increases.

[0055] Since the movement speed of the coating needle 24 and the shear rate of the coating material are considered to be proportional, the results in Figures 7 and 8 suggest that, when the coating material is an aqueous solution of a polymer, as the movement speed and shear rate of the coating material increase, the shear viscosity of the coating material decreases. This decrease in shear viscosity leads to an increase in the speed at which the coating material is pulled upward from the tip of the coating needle 24, and consequently, a decrease in the amount of coating material applied.

[0056] Figure 9(a) shows the amount of coating material 70 when the movement speed of the coating needle 24 is high, when the coating material is an aqueous solution of a polymer. Figure 9(b) shows the amount of coating material 70 when the movement speed of the coating needle 24 is at an intermediate level, when the coating material is an aqueous solution of a polymer. Figure 9(c) shows the amount of coating material 70 when the movement speed of the coating needle 24 is low, when the coating material is an aqueous solution of a polymer. As shown in these figures, when the coating material is an aqueous solution of a polymer, it can be seen that the amount of coating material applied decreases as the movement speed of the coating needle 24 increases.

[0057] Therefore, the inventors of the present invention were able to conceive that the target amount of coating material 70 can be applied by changing the movement speed of the coating needle 24 according to the type of coating material 70 and the target amount of coating material.

[0058] To achieve the above, the control computer 10 controls the drive unit 90 to move the coating needle 24 so that the coating material 70 is sheared at a shear rate corresponding to the type of coating material and the target coating amount. In other words, the control computer 10 controls the drive unit 90 to move the coating needle 24 so that when the coating needle 24 passes through the through hole 72, the coating material is sheared at a shear rate corresponding to the type of coating material and the target coating amount.

[0059] More specifically, the control computer 10 stores a speed table.

[0060] Figure 10 shows an example of a speed table in the first embodiment. As shown in Figure 10, the speed table determines the travel speed vk corresponding to the type of coating material ai and the target coating amount bj.

[0061] The speed table is set such that, when the type of coating material is a pseudoplastic fluid, the movement speed decreases as the target coating amount increases. When the type of coating material is a dilarant fluid, the speed table is set so that the movement speed increases as the target coating amount increases. When the type of coating material is a Bingham fluid, the speed table is set so that when the target coating amount is below a predetermined value, the movement speed decreases as the target coating amount increases, and when the target coating amount exceeds a predetermined value, the movement speed remains constant regardless of the target coating amount.

[0062] The control computer 10 determines the vertical downward movement speed of the coating needle 24 by referring to the speed table in Figure 10.

[0063] Figure 11 is a flowchart illustrating the procedure for controlling the drive of the coating needle 24 in the first embodiment.

[0064] Referring to Figure 11, in step S101, the control computer 10 acquires information on the coating material and the target coating amount. This information may be acquired through user input or automatically by the control computer 10 via communication.

[0065] In step S102, the control computer 10 refers to the speed table shown in Figure 10 to determine the vertical downward movement speed of the coating needle 24 corresponding to the coating material and the target coating amount.

[0066] In step S103, the control computer 10 controls the movement of the coating needle 24 so that the speed at which the coating needle 24 passes through the through hole 72 is the determined moving speed, thereby performing the coating of the coating material 70 onto the substrate 5.

[0067] As described above, conventionally, in the fine coating of non-Newtonian fluids, there was a problem that it took a long time to adjust the coating amount. However, in this embodiment, by controlling the vertical downward movement speed of the coating needle according to the target coating amount and the type of coating material, it becomes possible to adjust the coating amount in substantially the same amount of time as general coating work.

[0068] [Second Embodiment] Figure 12 shows the state of the coating needle 24 when it protrudes from the through hole 72.

[0069] When the tip of the coating needle 24 protrudes from the through hole 72, a gap exists between the coating needle 24 and the outer wall of the through hole 72. As shown in Figure 12, if the tip has a shape that becomes thinner towards the end, the gap spacing d will differ depending on the location of the tip. Figure 12 shows the gap d1 at one location of the tip.

[0070] As the distance between the coating needle 24 and the outer wall of the through-hole 72 increases, the shear force decreases, and therefore the shear viscosity decreases. Consequently, as the distance increases, the shear viscosity of the coating material decreases, and as the shear viscosity of the coating material decreases, the speed at which the coating material is pulled upward from the tip of the coating needle 24 increases, and it is expected that the amount of coating material will decrease.

[0071] In this embodiment, the control computer 10 controls the drive unit 90 to move the coating needle 24 so that the coating material 70 is sheared at a shear rate corresponding to the type of coating material, the target coating amount, and the distance between the coating needle 24 and the outer wall of the through hole 72. Here, the distance between the coating needle 24 and the outer wall of the through hole 72 can be the minimum, maximum, or average value of the distance at each point of the tip. In other words, the control computer 10 controls the drive unit 90 to move the coating needle 24 so that when the coating needle 24 passes through the through hole 72, the coating material is sheared at a shear rate corresponding to the type of coating material, the target coating amount, and the distance between the coating needle 24 and the outer wall of the through hole 72.

[0072] Figure 13 shows an example of a speed table according to a second embodiment. As shown in Figure 13, the speed table defines the type of coating material ai, the target coating amount bj, and the travel speed vk corresponding to the distance cl between the coating needle and the outer wall of the through hole.

[0073] The speed table is set such that, when the type of coating material and the target coating amount are the same, the travel speed decreases as the distance between the coating needle and the outer wall of the through-hole increases.

[0074] The speed table is set such that, when the distance between the coating needle and the outer wall of the through-hole is the same and the type of coating material is a pseudoplastic fluid, the movement speed decreases as the target coating amount increases. The speed table is set such that, when the distance between the coating needle and the outer wall of the through-hole is the same and the type of coating material is a dilarant fluid, the movement speed increases as the target coating amount increases. The speed table is set such that, when the distance between the coating needle and the outer wall of the through-hole is the same and the type of coating material is a Bingham fluid, the movement speed decreases as the target coating amount increases when the target coating amount is less than or equal to a predetermined value, and remains constant regardless of the target coating amount when the target coating amount exceeds a predetermined value.

[0075] The control computer 10 determines the vertical downward movement speed of the coating needle 24 by referring to the speed table in Figure 13.

[0076] Figure 14 is a flowchart illustrating the procedure for controlling the drive of the coating needle 24 in the second embodiment.

[0077] Referring to Figure 14, in step S201, the control computer 10 acquires information on the coating material, the distance between the coating needle 24 and the outer wall of the through hole 72, and the target coating amount. This information may be acquired by user input or by the control computer 10 automatically through communication.

[0078] In step S202, the control computer 10 refers to the speed table shown in Figure 13 to determine the vertical downward movement speed of the coating needle 24 corresponding to the coating material and the target coating amount.

[0079] In step S203, the control computer 10 controls the movement of the coating needle 24 so that the speed at which the coating needle 24 passes through the through hole 72 is the determined moving speed, thereby performing the coating of the coating material 70 onto the substrate 5.

[0080] In this embodiment, by controlling the downward vertical movement speed of the coating needle according to the target coating amount, the distance between the coating needle and the outer wall of the through-hole, and the type of coating material, it becomes possible to adjust the coating amount in substantially the same amount of time as a typical coating operation.

[0081] (Modified versions of Embodiments 1 and 2) The present invention is not limited to the embodiments described above, and includes, for example, the following modifications. (1) Coating diameter The coating amount is expressed by the coating diameter, which represents the size of the coating film, and the thickness of the coating film. If the thickness of the coating film can be considered constant, the coating diameter and the coating amount are proportional, so the coating diameter may be used instead of the coating amount.

[0082] Figure 15 shows an example of a speed table for Modification 1. As shown in Figure 15, the speed table determines the type of coating material ai and the travel speed vk corresponding to the target coating diameter ej.

[0083] Figure 16 shows an example of a speed table for Modification 2. As shown in Figure 16, the speed table determines the type of coating material ai, the target coating diameter ej, and the travel speed vk corresponding to the distance cl between the coating needle and the outer wall of the through hole. (2) Conservation of movement speed The control device may retain a determined value for the travel speed in order to change the coating speed during operation.

[0084] [Third Embodiment] The coating apparatus of this embodiment uses a cell-containing solution (hereinafter referred to as the cell-containing solution) as the coating material. The cell-containing solution is a non-Newtonian fluid, similar to the Bingham fluid, pseudoplastic fluid, and dilatant fluid described in the first and second embodiments.

[0085] The inventors of this application investigated the change in the amount of material applied in response to a change in the application speed, using a cell-containing solution obtained by adding cells to a hyaluronic acid solution as the application material.

[0086] Figure 17 shows the measurement results of the coating diameter against the coating speed when the coating material is a cell-containing solution in which cells are contained in a hyaluronic acid solution.

[0087] As shown in Figure 17, when the coating material is a cell-containing solution containing cells in a hyaluronic acid solution, increasing the coating speed reduces the coating diameter, which is the amount of coating applied. Therefore, using the coating device of this embodiment, the number of cells coated can be changed by varying the coating speed, while keeping the cell concentration in the cell-containing solution constant.

[0088] The speed table in Figure 10 described in the first embodiment can include a cell-containing solution as the coating material. When the type of coating material is a cell-containing solution, the speed table in Figure 10 can be set so that the movement speed decreases as the target coating amount increases.

[0089] The speed table in Figure 13, described in the second embodiment, can include a cell-containing solution as the coating material. In the case where the distance between the coating needle and the outer wall of the through-hole is the same and the type of coating material is a cell-containing solution, the speed table in Figure 13 can be set so that the larger the target coating amount, the smaller the movement speed.

[0090] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The scope of the present invention is indicated by the claims rather than by the foregoing description, and all modifications within the meaning and scope equivalent to the claims are intended to be included. [Explanation of Symbols]

[0091] 1 X-axis table, 2 Y-axis table, 3 Z-axis table, 4 coating mechanism, 5 substrate, 6 observation optics, 7 CCD camera, 8 operation panel, 9 monitor, 10 control computer, 20 coating needle holder, 21 coating material container, 24 coating needle, 41 servo motor, 43 cam, 44 bearing, 45 cam connecting plate, 46 movable part, 47 coating needle holder fixing part, 48 coating needle holder storage part, 49 linear guide, 50 spring, 51, 52 fixing pins, 61 cam surface, 62 upper flat area, 63 lower flat area, 70 coating material, 72 through hole, 80 control device, 90 drive unit.

Claims

1. A coating needle for applying a coating material whose viscosity changes due to shear to an object, A drive unit for raising and lowering the coating needle, The container holds the coating material and has a through hole in the bottom facing the object through which the coating needle protrudes, The device comprises a control unit that determines the vertical downward movement speed of the coating needle as it passes through the through hole according to the type of coating material and the target coating diameter when the target coating amount or coating film thickness is constant, and controls the speed at which the coating needle passes through the through hole to the determined movement speed, The coating apparatus includes, as the type of coating material, pseudoplastic fluids, Bingham fluids, and dilatant fluids.

2. The coating apparatus according to claim 1, wherein the control device determines the vertical downward movement speed of the coating needle when it passes through the through hole, based on the type of coating material, the target coating diameter when the target coating amount or the thickness of the coating film is constant, and the distance between the coating needle and the outer wall of the through hole when the coating needle protrudes from the through hole, and controls the speed of the coating needle when it passes through the through hole to the determined movement speed.

3. The coating apparatus according to claim 2, wherein the control device has a table that defines the type of coating material, the target coating diameter when the target coating amount or the thickness of the coating film is constant, and the interval, and the control device determines the moving speed by referring to the table.

4. The coating apparatus according to claim 3, wherein the table is configured such that the distance between the coating needle and the outer wall of the through hole is the same, and when the type of coating material is the pseudoplastic fluid, the larger the target coating diameter is when the target coating amount or the thickness of the coating film is constant, the smaller the moving speed.

5. The coating apparatus according to claim 4, wherein the table is configured such that the distance between the coating needle and the outer wall of the through hole is the same, and when the type of coating material is the dilatant fluid, the movement speed increases as the target coating diameter is larger when the target coating amount or the thickness of the coating film is constant.

6. The coating apparatus according to claim 4, wherein the distance between the coating needle and the outer wall of the through hole is the same, and when the type of coating material is the Bingham fluid, the table is configured such that when the target coating diameter when the target coating amount or the thickness of the coating film is constant is less than or equal to a predetermined value, the larger the target coating diameter when the target coating amount or the thickness of the coating film is constant, the smaller the moving speed becomes, and when the target coating diameter when the target coating amount or the thickness of the coating film is constant exceeds the predetermined value, the moving speed becomes constant regardless of the target coating diameter when the target coating amount or the thickness of the coating film is constant.

7. The coating apparatus according to claim 4, wherein the table is configured such that the movement speed decreases as the distance between the coating needle and the outer wall of the through hole increases, when the type of coating material and the target coating diameter when the target coating amount or the thickness of the coating film is constant are the same.

8. The coating apparatus according to claim 4, wherein the type of coating material is a cell-containing solution obtained by containing cells in a hyaluronic acid solution.

9. The coating apparatus according to claim 8, wherein the table is configured such that, when the distance between the coating needle and the outer wall of the through hole is the same, the movement speed decreases as the target coating diameter increases when the target coating amount or the thickness of the coating film is constant.

10. A coating method comprising a coating apparatus having a coating needle for applying a coating material whose viscosity changes due to shear to an object, and a container for holding the coating material and having a through hole in the bottom facing the object through which the coating needle protrudes, A step of determining the vertical downward movement speed of the coating needle as it passes through the through hole, based on the type of coating material, the target coating diameter when the target coating amount or coating film thickness is constant, and the distance between the coating needle and the outer wall of the through hole when the coating needle protrudes from the through hole. The method includes the step of controlling the speed at which the coating needle passes through the through hole to the determined moving speed, The coating method wherein the type of coating material includes pseudoplastic fluids, Bingham fluids, and dilatant fluids.

11. The type of the coating material is a cell-containing solution obtained by adding cells to a hyaluronic acid solution. The coating method according to claim 10, wherein the step of determining the above involves determining the moving speed by referring to a table that defines the moving speed for the type of coating material, the target coating diameter when the target coating amount or the thickness of the coating film is constant, and the interval, and the table is set such that, when the interval between the coating needle and the outer wall of the through hole is the same, the larger the target coating diameter when the target coating amount or the thickness of the coating film is constant, the smaller the moving speed.

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