Coating needle, coating mechanism, coating device, and coating method
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2026-01-28
- Publication Date
- 2026-08-13
Smart Images
Figure JP2026002861_13082026_PF_FP_ABST
Abstract
Description
Coating needle, coating mechanism, coating device, and coating method
[0001] The present invention relates to a coating needle, a coating mechanism, a coating device, and a coating method.
[0002] In recent years, printed electronics technology for forming fine circuits such as RFID (Radio Frequency Identification) tags by a printing (coating) method has been rapidly developing. As methods for forming fine circuits and electrode patterns, printing methods, inkjet methods, etc. are common, but a method using a coating needle has also attracted attention in recent years because it enables fine coating using materials with a wide range of viscosities. A coating device using a coating needle is disclosed, for example, in Japanese Patent Application Laid-Open No. 2008-296149 (Patent Document 1).
[0003] Japanese Patent Application Laid-Open No. 2008-296149
[0004] The coating device disclosed in Japanese Patent Application Laid-Open No. 2008-296149 includes a coating needle. The coating needle has a flat surface at its tip. The coating needle is formed with a tapered portion whose cross-section gradually shrinks toward the tip.
[0005] Consider the case of applying a coating material using the coating needle of Japanese Patent Application Laid-Open No. 2008-296149. In this case, while the tip of the coating needle is moving away from the coating material in which it is immersed and descending toward the coating object, the coating material attached to the tip of the coating needle dries. The drying of the coating material occurs when the moisture in the coating material evaporates. When the coating material dries due to the evaporation of moisture, the solid components in the coating material solidify and deposit on the tip of the coating needle. This may affect the operation of the coating needle.
[0006] The present invention has been made in view of the above problems. An object of the present invention is to provide a coating needle, a coating mechanism, a coating device, and a coating method that can delay the evaporation of moisture in the coating material and apply a sufficient amount of the coating material to the coating object material.
[0007] The coating needle according to this disclosure is capable of approaching the surface of the material to be treated. The coating needle has a tip portion, which is one end in the direction of extension, that can follow the surface of the material to be treated. The tip portion is capable of approaching the surface of the material to be treated. The arithmetic mean height of the tip portion is 0.1 μm or less.
[0008] The coating mechanism according to this disclosure comprises a coating needle, a positioning mechanism, and a coating material container. The coating needle is capable of approaching the surface of the material to be processed. The positioning mechanism can control the relative position of the coating needle with respect to the material to be processed in the vertical direction. The coating material container can hold the coating material to be applied to the coating needle. A through hole is formed in the bottom of the coating material container through which at least a portion of the coating needle can pass. The coating needle has a tip surface at one end in the direction of extension that can follow the surface of the material to be processed. The tip surface is capable of approaching the surface of the material to be processed. The arithmetic mean height of the tip surface is 0.1 μm or less.
[0009] A coating apparatus according to this disclosure comprises the above-described coating mechanism and a holding base for holding the material to be processed.
[0010] The coating method according to this disclosure uses the coating mechanism described above. In this coating method, the material to be treated is placed directly below the coating material container. The coating material is applied to the surface of the material to be treated using the coating needle. In the process of applying the coating material, the positioning mechanism controls the application so that the coating material attached to the tip of the coating needle adheres to the surface of the material to be treated within 178 milliseconds from the time the coating needle begins to descend.
[0011] The coating needle of this disclosure has an arithmetic mean height Sa (arithmetic mean roughness according to ISO 25178) of 0.1 μm or less at the tip surface. This delays the evaporation of moisture in the coating material, allowing a sufficient amount of coating material to be applied to the target material.
[0012] The coating mechanism of this disclosure includes a coating needle, the arithmetic mean height Sa of the tip surface of the coating needle being 0.1 μm or less. This delays the evaporation of moisture in the coating material, allowing a sufficient amount of coating material to be applied to the material to be coated.
[0013] The coating apparatus of this disclosure includes the above-described coating mechanism. This delays the evaporation of moisture in the coating material, allowing a sufficient amount of coating material to be applied to the material to be coated.
[0014] The coating method of this disclosure uses the coating mechanism described above. This coating method causes the coating material attached to the tip of the coating needle to adhere to the surface of the material to be treated within 178 milliseconds from the time the coating needle begins to descend. This delays the evaporation of moisture in the coating material, allowing a sufficient amount of coating material to be applied to the material to be treated.
[0015] This is a schematic diagram of a coating apparatus according to this embodiment. This is a schematic diagram showing the coating mechanism provided in the coating apparatus shown in Figure 1. This is a schematic diagram showing the base body in the coating mechanism of Figure 2. This is a schematic diagram for explaining the cam member of the coating mechanism shown in Figures 2 and 3. This is a schematic perspective view of the coating needle holder provided in the coating mechanism of Figure 2. This is an exploded view of the coating needle holder of Figure 5. This is a front view showing the tip of the coating needle used in the coating apparatus of this embodiment. This is a bottom view of the coating needle shown in Figure 7. This is a schematic diagram for explaining the operation of the coating needle in the coating mechanism shown in Figure 2. This is a flowchart of a coating method using a coating apparatus equipped with the coating mechanism according to this embodiment. This is a flowchart showing the process (S20) of Figure 10 in detail. This is a photograph showing the state of the tip of the coating needle after a certain period of time has elapsed from the time the coating needle begins to descend in Example 1. This is a photograph showing the state of the tip of the coating needle after a certain period of time has elapsed from the time the coating needle begins to descend in Example 2. This photograph shows the change in the shape of the tip of the coating needle after a certain period of time has elapsed from the moment the coating needle begins to descend, when the arithmetic mean height of the tip surface of the coating needle is changed in Example 3.
[0016] The embodiment will be described below with reference to the drawings. (Overall configuration of the coating apparatus) Figure 1 is a schematic diagram of a coating apparatus according to this embodiment. For the sake of explanation, the X, Y, and Z directions are introduced. As shown in Figure 1, the coating apparatus 100 mainly 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 unit. The control unit includes a monitor 9, a control computer 10, and an operation panel 8.
[0017] Inside the processing chamber, a Y-axis table 2 is installed on the bottom of the chamber. This Y-axis table 2 is movable in the Y-axis direction. Specifically, a guide part is installed on the underside of the Y-axis table 2. This guide part is slidably connected to a guide rail installed on the bottom of the processing chamber. A ball screw is also connected to the underside of the Y-axis table 2. By operating this ball screw with a drive member such as a motor, the Y-axis table 2 can move along the guide rail (in the Y-axis direction). The upper surface of the Y-axis table 2 is a mounting surface on which the substrate 5, the material to be processed, is mounted.
[0018] An X-axis table 1 is installed 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 installed on the X-axis table 1 so as to be movable in the X-axis direction. The movable body is 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 described above is movable in the Y-axis direction relative to the X-axis table 1.
[0019] 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 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.
[0020] The 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 the 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.
[0021] (Configuration of the coating mechanism) Figure 2 is a schematic diagram showing the coating mechanism provided in the coating apparatus shown in Figure 1. Figure 3 is a schematic diagram showing the base body in the coating mechanism of Figure 2. As shown in Figures 2 and 3, the coating mechanism 4 mainly includes a servo motor 41, a cam 43, a bearing 44 held in contact with the cam surface of the cam 43, a cam connecting plate 45, a movable part 46, a movable base 35 (base body) that holds the coating needle holder 20, and a coating material container 21. The coating needle holder 20 is detachable from the movable base 35.
[0022] In the coating mechanism 4, the servo motor 41 is installed so that its central 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 rotatable about the central axis of the servo motor 41. The cam 43 includes a central part connected to the rotation axis of the servo motor 41 and a flange portion connected to one end of the central part.
[0023] Figure 4 is a schematic diagram illustrating the cam member of the coating mechanism shown in Figures 2 and 3. As shown in Figure 4(A), the upper surface of the flange (the surface on the servo motor 41 side) is a cam surface 61. This cam surface 61 is formed in an annular shape along the outer circumference of the center and is also formed in a slope shape so that the distance from the bottom surface of the flange varies. Specifically, as shown in Figure 4(B), the cam surface 61 includes an upper flat region 62 which is the furthest from the bottom surface of the flange (thickest), a lower flat region 63 which is spaced apart from the upper flat region 62, and a slope that smoothly connects the upper flat region 62 and the lower flat region 63. The lower flat region 63 is the region which is the closest from the bottom surface (thinnest). Here, Figure 4(B) is a side view of the flange, including the cam surface 61 which is arranged in an annular shape surrounding the center.
[0024] A bearing 44 is positioned so as to be in contact with the cam surface of the cam 43. A cam connecting plate 45 is connected to this bearing 44. On the cam connecting plate 45, one end connected to the bearing 44 and the other end opposite to it are fixed to a movable part 46. A movable base 35 is connected to this movable part 46. A coating needle holder 20 is installed on this movable base 35. 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 its lower surface (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.
[0025] The coating material container 21 is capable of holding the coating material 70. The coating material 70 is a liquid material that is applied to the tip of the coating needle 24 in particular. The coating material 70 may be a highly viscous liquid material. The tip of the coating needle 24 is immersed in the coating material 70 contained in the coating material container 21. As a result, the coating material 70 adheres to the tip of the coating needle 24. The coating material 70 attached to the tip of the coating needle 24 is supplied to the surface of the material to be treated. As a result, the desired coating material is applied to the desired location.
[0026] A fixing pin is fixed to the movable part 46. The other fixing pin is fixed to the frame that holds the servo motor 41. A spring is installed to connect these fixing pins. Due to this spring, the movable part 46 is subjected to a force directed toward the coating material container 21. Furthermore, the force of this spring maintains the bearing 44 in a state of being pressed against the cam surface of the cam 43.
[0027] Furthermore, the movable part 46 and the movable base 35 are connected to a linear guide installed on a frame that holds the servo motor 41, and are movable along the Z-axis direction.
[0028] In the coating mechanism 4 described above, the servo motor 41 is driven to rotate its rotation axis, thereby rotating the cam 43. As a result, the position of the bearing 44 in contact with the cam surface of the cam 43 in the Z-axis direction changes in accordance with the rotation of the servo motor 41's rotation axis. Then, in accordance with this change in the Z-axis position of the bearing 44, the movable part 46 and the movable base 35 move in the Z-axis direction, thereby changing the position of the coating needle 24 in the Z-axis direction.
[0029] The coating mechanism 4 includes a positioning mechanism 410. The positioning mechanism 410 can control the relative position of the coating needle 24 with respect to the substrate 5 in the vertical direction (Z direction). In other words, the positioning mechanism 410 controls the position of the coating needle 24 in the Z direction. This control prevents problems such as the coating needle 24 colliding with the substrate 5.
[0030] The positioning mechanism 410 consists of a servo motor 41, a cam 43, a bearing 44, a cam connecting plate 45, a movable part 46, a movable base 35, and a linear guide mounted on a frame that holds the servo motor 41. The linear guide is not explicitly shown in Figures 2 and 3. The linear guide may be considered as being included in the movable part 46.
[0031] (Configuration of the coating needle holder) Figure 5 is a schematic perspective view of the coating needle holder provided in the coating mechanism of Figure 2. Figure 6 is an exploded view of the coating needle holder of Figure 5. When the coating needle holder 20 is not disassembled (the holder cover is closed), it has the configuration shown in Figure 5. As shown in Figure 6, the coating needle holder 20 mainly includes a holder base 22, a coating needle fixing plate 25 to which the coating needle 24 is fixed, and a holder cover 23. A recess is formed inside the holder base 22 for housing the coating needle fixing plate 25 to which the coating needle 24 is adhesively fixed. A linear guide 26 is also fixed inside this recess. The linear guide 26 is positioned to define the direction of movement of the coating needle fixing plate 25. The coating needle fixing plate 25 is held in contact with the linear guide 26.
[0032] Furthermore, a spring 27, acting as an elastic member, is connected to the other end of the coating needle fixing plate 25 opposite to the end where the coating needle 24 is fixed. This spring 27 is positioned sandwiched between the other end of the coating needle fixing plate 25 and the spring receiver 28 in the holder cover 23. By positioning this spring 27 in a somewhat compressed state, the coating needle fixing plate 25 can be pressed toward the coating needle 24. This prevents the position of the coating needle 24 from shifting (varying vertically relative to the holder base) when the coating needle 24 is moved up and down. In addition, this spring 27 absorbs stress by elastically deforming when excessive stress is applied to the coating needle 24 when it comes into contact with the surface of the substrate 5, which is the material to be processed.
[0033] Furthermore, since the stress applied to the coating needle 24 when it contacts the surface of the substrate 5 is influenced by the force from the spring 27, it is preferable that the force applied by the spring 27 to the coating needle fixing plate 25 be adjusted to the minimum value necessary to hold the coating needle 24 in the position on the substrate side.
[0034] The holder cover 23 has an elongated hole 29 through which a screw used to fix the holder cover 23 to the holder base 22 passes. When the holder cover 23 is installed on the holder base 22, the elongated hole 29 is formed to have a major axis in the direction along which the linear guide 26 extends (i.e., the direction in which the coating needle 24 moves). As a result, the position of the holder cover 23 relative to the holder base 22 can be changed in the direction of the major axis of the elongated hole, and then the holder cover 23 can be fixed to the holder base 22. Therefore, by changing the position of the holder cover 23 relative to the holder base 22, the distance between the spring receiver 28 and the end of the coating needle fixing plate 25 (the size of the area where the spring 27 is placed) can be changed. Therefore, when assembling the coating needle holder 20, for example, the holder cover 23 may be fixed to the holder base 22 while measuring the force applied to the tip of the coating needle 24 by the spring 27.
[0035] As shown in Figure 3, in the coating mechanism 4, the coating needle holder 20 shown in Figure 5 is detachably attached to the movable base 35. Specifically, although not shown, the coating needle holder 20 in Figure 5 has multiple magnets arranged on the surface that faces the movable base 35 (the surface of the holder base 22). There are, for example, two magnets. The movable base 35 in Figure 3 is also provided with two magnets 33. The magnets of the coating needle holder 20 (not shown) and the magnets 33 of the movable base 35 shown in Figure 3 attract each other. This allows the coating needle holder 20 to be installed on the movable base 35.
[0036] Furthermore, by adjusting the positions of magnets 32 and 33, the position of the coating needle holder 20 can be precisely positioned when it is attracted to the movable base 35 by the magnetic force acting between magnets 32 and 33. For example, the reference surface 30 of the coating needle holder 20 (see Figure 5) can be pressed against the reference surface 34 on the movable base 35, while the reference surface 31 of the coating needle holder 20 (see Figure 5) can be pressed against the reference surface 36 on the movable base 35.
[0037] (Configuration of the coating needle) As described above, the coating needle 24 of this embodiment is provided in the coating mechanism 4. As shown in Figure 5, the coating needle 24 of this embodiment has a base end portion 24A and a tip end portion 24B. As shown in Figure 5, the base end portion 24A is positioned above the tip end portion 24B in the Z direction. The base end portion 24A is attached to the coating needle fixing plate 25.
[0038] The coating needle 24 can approach the surface of the substrate 5. That is, by moving downward in the Z direction, the coating needle 24 can approach the surface of the material to be processed, such as the substrate 5, which is located below the coating needle 24. As a result of approaching the substrate 5, the tip portion 24B of the coating needle 24 may come into contact with the surface of the substrate 5.
[0039] Figure 7 is a front view showing the tip of the coating needle used in the coating apparatus of this embodiment. Figure 8 is a bottom view of the coating needle shown in Figure 7. In other words, Figure 8 shows Figure 7 as viewed from the direction indicated by arrow VIII. As shown in Figure 7, the tip portion 24B has a constant width portion 24Ba and a tip portion 24Bb. The constant width portion 24Ba is positioned above the tip portion 24Bb in the Z direction. That is, the constant width portion 24Ba is connected to the base portion 24A. In the constant width portion 24Ba, the dimensions of the coating needle 24 in the X and Y directions are constant. In the constant width portion 24Ba, the outer edge of the coating needle 24 extends along (almost parallel to) the Z direction. Therefore, in the constant width portion 24Ba, the cross-sectional area along the XY plane does not change and remains almost constant.
[0040] The tip portion 24Bb is one end of the coating needle 24 in the Z direction, which is the direction in which the coating needle 24 extends, i.e., the lower end. The tip portion 24Bb can approach or contact a surface such as the substrate 5. The dimensions of the coating needle 24 in the X and Y directions are not constant at the tip portion 24Bb. At the tip portion 24Bb, the cross-sectional area along the XY plane changes. Specifically, at the tip portion 24Bb, the dimensions of the coating needle 24 in the X and Y directions gradually decrease from the upper side (the side with the constant width portion 24Ba) in the Z direction towards the lower side. Therefore, at the tip portion 24Bb, the cross-sectional area along the XY plane gradually decreases from the upper side to the lower side in the Z direction.
[0041] The tip portion 24Bb has a tip surface 24Bc. The tip surface 24Bc is located at the lowest point in the Z direction of the tip portion 24Bb. In other words, the tip surface 24Bc is located at the lowest point in the Z direction of the entire coating needle 24. The tip surface 24Bc is a surface that extends along the XY plane that intersects (for example, perpendicular to) the coating needle 24 when the coating needle 24 extends along the Z direction. For this reason, the tip surface 24Bc can be positioned along the surface (main surface) of the material to be processed, such as the substrate 5. As a result, the coating needle 24 has a tip surface 24Bc formed at its tip. The coating needle 24 has a tip portion 24Bb, which is a tapered portion whose cross-section gradually expands along the axial direction (Z direction) from the tip surface 24Bc, formed on the tip side portion 24B.
[0042] The tip surface 24Bc of the coating needle 24 in Figures 7 and 8 is generally a flat surface. Specifically, the arithmetic mean height Sa of the tip surface 24Bc is 0.1 μm or less. Here, the arithmetic mean height Sa represents the value over the entire tip surface 24Bc. However, if the tip surface 24Bc has a circular planar shape, the arithmetic mean height Sa is 0.1 μm or less in an area range of at least 80% of its total area, including the center. It is more preferable that the arithmetic mean height Sa is 0.07 μm or less, and even more preferable that it is 0.0689 μm or less. Furthermore, it is particularly preferable that the arithmetic mean height Sa is 0.03 μm or less. The arithmetic mean height Sa is measured by a white light interferometer. The arithmetic mean height Sa may also be measured by an optical microscope.
[0043] (Coating Operation) Next, the coating operation by the coating mechanism 4 will be described. FIG. 9 is a schematic diagram for explaining the operation of the coating needle in the coating mechanism shown in FIG. 2. When the bearing 44 is in contact with the upper end flat region 62 on the cam surface 61 of the cam 43 shown in FIG. 4, the coating needle 24 is arranged at its upper end position (the position closest to the servo motor 41) as shown in (A) of FIG. 9. At this time, the tip portion 24Bb (including the tip surface 24Bc) 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 25A that projects the coating needle 24 at the bottom facing the substrate 5, which is the object.
[0044] Next, consider the case where the servo motor 41 rotates the rotating shaft, the cam 43 rotates, and the bearing 44 comes to a position where the lower end flat region 63 of the cam surface 61 contacts the bearing 44. In this case, as shown in (B) of FIG. 9, particularly the tip portion 24Bb, which is a part of the coating needle 24, penetrates the through hole 25A 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 part of the coating material 70 adheres to the surface of the coating needle 24 protruding from the bottom surface of the coating material container 21. By moving the Z-axis table 3 (see FIG. 1) to the substrate 5 side with the coating mechanism 4, the tip of the coating needle 24 contacts the surface of the substrate 5, and the coating material 70 can be applied to the surface of the substrate 5. Note that the servo motor 41 may be driven after the movement of the Z-axis table 3 is performed first, or the operations of the Z-axis table 3 and the servo motor 41 may be performed substantially simultaneously.
[0045] In the coating mechanism 4, the rotational motion of the servo motor 41 can be converted into the motion (vertical motion) of the coating needle 24 in the Z-axis direction. With such a configuration, the coating needle 24 can be moved quickly and accurately in the Z-axis direction.
[0046] (Coating Method) FIG. 10 is a flowchart showing a coating method using a coating apparatus including a coating mechanism according to the present embodiment. As shown in FIG. 10, the material to be processed is placed directly below the coating material container (S10). Specifically, as shown in FIGS. 1 and 9, the substrate 5 as the material to be processed is placed at a distance in the Z direction directly below the coating material container 21 included in the coating mechanism 4 of the coating apparatus 100. The means for placing the substrate 5 or the like directly below the coating material container 21 in step (S10) is not questioned.
[0047] As shown in FIG. 10, next, the coating material 70 is applied to the surface of the material to be processed using the coating needle (S20). Specifically, in the initial state shown in FIG. 9(A), the tip 24Bb (including the tip surface 24Bc) of the coating needle 24 is immersed in the coating material 70. As a result, the coating material 70 adheres to the surface of the tip 24Bb (including the tip surface 24Bc). Then, as shown in FIG. 9(B), the coating needle 24 descends with respect to the initial state shown in FIG. 9(A). The tip 24Bb including the tip surface 24Bc of the descended coating needle 24 contacts the surface of the substrate 5 directly below it. As a result, the coating material 70 adhering to the tip 24Bb (including the tip surface 24Bc) adheres to the surface of the substrate 5 directly below it. Thereby, the coating material 70 is applied to the surface of the substrate 5. However, the tip surface 24Bc may be applied to the surface of the substrate 5 without contacting the surface of the substrate 5 by approaching the surface of the substrate 5 so that the coating material 70 adhering to the tip 24Bb is applied onto the surface of the substrate 5.
[0048] FIG. 11 is a flowchart showing step (S20) of FIG. 10 in detail. As shown in FIG. 11, in step (S20), control by the positioning mechanism is performed (S21). That is, the position of the coating needle 24 in the Z direction is adjusted by the positioning mechanism 410 shown in FIGS. 2 and 3. In particular, in step (S21), the position of the tip surface 24Bc of the coating needle 24 in the Z direction is adjusted. This is because the tip surface 24Bc needs to descend in order to contact the surface of the substrate 5.
[0049] As shown in Figure 11, the downward movement of the coating needle 24 in process (S21) brings the tip surface 24Bc of the coating needle 24 closer to the surface of the substrate 5 (S22). At this time, the positioning mechanism 410 controls the point in time when the coating needle 24 begins to descend, which is considered the starting point. From this starting point, the tip portion 24Bb (tip surface 24Bc) of the coating needle 24 approaches the surface of the substrate 5. Within a certain time from the starting point, the tip surface 24Bc may come into contact with the surface of the substrate 5. Note that the point in time when the coating needle 24 begins to descend, which serves as the starting point, is equal to the point in time when the servo motor 41 begins to rotate. In other words, the point in time when the coating needle 24 begins to descend, which serves as the starting point, is equal to the point in time when the cam 43 begins to rotate.
[0050] For example, under the control of the positioning mechanism 410, it is preferable that the coating material 70 attached to the tip portion 24Bb (including the tip surface 24Bc) adheres to the surface of the substrate 5 within 178 milliseconds from the time when the coating needle 24 begins to descend. The time when the coating needle 24 begins to descend is equal to the time when the servo motor 41 and cam 43 begin to rotate. Figure 9(A) shows the initial state and the state at the time when the coating needle 24 begins to descend. In particular, in the process of applying the coating material 70 (S20), under the control of the positioning mechanism 410, it is preferable that the coating material 70 attached to the tip portion 24Bb (including the tip surface 24Bc) adheres to the surface of the substrate 5 within 35.2 milliseconds from the time when the coating needle 24 begins to descend. Figure 9(B) shows the state at the time when the tip portion 24Bb (including the tip surface 24Bc) of the coating needle 24 to which the coating material 70 has been attached comes into contact with the surface of the substrate 5. Furthermore, the coating material 70 on the tip portion 24Bb may adhere to the surface of the substrate 5 when the tip surface 24Bc comes into contact with the surface of the substrate 5.
[0051] For coating materials 70, when the tip of the coating needle 24 is brought into contact with the surface of the material to be treated within 178 milliseconds or 35.2 milliseconds from the time the coating needle 24 begins to descend, a protein-containing solution is a possible example. However, in a coating method using the coating apparatus 100, even if the coating material 70 is distilled water, it is preferable to bring the tip 24Bb of the coating needle 24 into contact with the surface of the material to be treated within 178 milliseconds or 35.2 milliseconds from the time the coating needle 24 begins to descend, as described above. This will be explained later.
[0052] The elapsed time from the time the coating needle 24 begins to descend can be measured, for example, using an oscilloscope.
[0053] (Effects) The coating needle 24 according to this embodiment is able to approach the surface of the material to be processed (for example, the substrate 5). The coating needle 24 has a tip surface 24Bc at one end, which is the tip portion 24Bb in the direction of extension, that can follow the surface of the material to be processed. The tip surface 24Bc is able to approach the surface of the material to be processed. The arithmetic mean height Sa of the tip surface 24Bc is 0.1 μm or less. By setting the arithmetic mean height Sa of the tip surface 24Bc to 0.1 μm or less, the evaporation of moisture in the coating material 70 at the tip surface 24Bc is delayed, and the coating material 70 can be applied to the surface of the material to be processed with a large amount of coating material 70 adhering to it. By setting the arithmetic mean height Sa of the tip surface 24Bc to 0.1 μm or less, a state in which a large amount of moisture contained in the coating material 70 adheres to the tip surface 24Bc is maintained, and the amount of coating material 70 applied to the material to be processed can be increased. Therefore, it is possible to prevent the problem of solid components in the coating material 70 solidifying and precipitation on the coating needle 24 due to the drying of the coating material 70. This will be described in detail in a later example.
[0054] The coating mechanism 4 according to this embodiment comprises a coating needle 24, a positioning mechanism 410, and a coating material container 21. The coating needle 24 is capable of approaching the surface of the material to be processed (for example, a substrate 5). The positioning mechanism 410 can control the relative position of the coating needle 24 with respect to the material to be processed in the vertical direction. The coating material container 21 is capable of storing the coating material 70 to be attached to the coating needle 24. A through hole 25A is formed at the bottom of the coating material container 21 through which at least a part of the coating needle 24 (for example, the tip portion 24Bb) can pass. The coating needle 24 has a tip surface 24Bc at one end, the tip portion 24Bb, which is one end in the extending direction, that can follow the surface of the substrate 5, which is the material to be processed. The tip portion 24Bb is capable of approaching the surface of the material to be processed. The arithmetic mean height Sa of the tip surface 24Bc is 0.1 μm or less. By setting the arithmetic mean height Sa of the tip surface 24Bc to 0.1 μm or less, it is possible to prevent the defect of solid components in the coating material 70 solidifying and precipitation on the coating needle 24 due to the drying of the coating material 70, similar to the above.
[0055] The coating apparatus 100 according to this embodiment comprises the coating mechanism 4 described above and a holding base (Y-axis table 2) for holding the substrate 5 or the other material to be processed. The coating apparatus 100 with this configuration achieves the effects of the coating needle 24 and coating mechanism 4 described above.
[0056] The coating method according to this embodiment is a coating method using the coating mechanism 4 described above. The coating method according to this embodiment is a coating method using the coating needle 24 described above. In this coating method, the substrate 5 or the other material to be processed is placed directly below the coating material container 21. The coating material 70 is applied to the surface of the material to be processed using the coating needle 24. In the process of applying the coating material 70, the positioning mechanism 410 controls the application so that the coating material 70 attached to the tip 24Bb of the coating needle 24 adheres to the surface of the material to be processed within 178 milliseconds from the time the coating needle 24 begins to descend. By bringing the coating material 70 attached to the tip 24Bb into contact with the material to be processed within 178 milliseconds from the time the coating needle 24 begins to descend, the coating material 70 can be applied to the material to be processed while maintaining a state in which a large amount of moisture contained in the coating material 70 adheres to the tip surface 24Bc. Therefore, it is possible to prevent the problem of solid components in the coating material 70 solidifying due to drying and precipitation on the coating needle 24. This will be described in detail in a later embodiment. In the above coating process, it is preferable that the coating material 70 attached to the tip 24Bb of the coating needle 24 adheres to the surface of the material to be treated within 35.2 milliseconds from the time the coating needle 24 begins to descend, controlled by the positioning mechanism 410. This enhances the above-mentioned effects.
[0057] The coating material described above can be considered to be distilled water. As will be described later, if the coating is applied to the surface of the material to be treated within 178 milliseconds from the start of the descent of the coating needle 24, the tip surface 24Bc of the coating needle 24 will come into contact with the material to be treated while the distilled water has not evaporated. In other words, if the coating material 70 is applied within 178 milliseconds from the start of the descent of the coating needle 24, the coating material 70 in which the moisture has not evaporated can be applied to the material to be treated. This prevents defects caused by drying of the coating material 70.
[0058] It should be noted that the coating material 70 is actually a protein-containing solution. Unlike distilled water, the coating material 70 actually contains many substances other than water and may be more viscous than distilled water. However, even if the coating material 70 is more viscous than distilled water, the evaporation of the water it contains is still the problem. It is safe to assume that the water contained in the coating material 70 has the same components as distilled water. Therefore, the optimal conditions obtained from the verification results using distilled water, described below, can be directly applied as conditions to prevent the drying of the coating material 70 in actual use.
[0059] In this embodiment, the adhesion state of distilled water to the tip portion 24Bb of the coating needle 24 was confirmed using the coating apparatus 100 (including the coating mechanism 4) shown in Figure 1. The distilled water is stored in the liquid material container 21 and adheres to the coating needle 24 within the liquid material container 21. The tip portion 24Bb includes the tip surface 24Bc (see Figures 7 and 8; the same applies hereafter). The tip surface 24Bc of the coating needle 24 used, as shown in Figures 7 and 8, was circular with a diameter of 150 μm in plan view. The arithmetic mean height Sa of the tip surface 24Bc of the coating needle 24 used was 0.3845 μm. In other words, the tip surface 24Bc in this embodiment was a relatively rough surface. The coating needle 24, including its tip surface 24Bc, is immersed in the coating material 70 as shown in Figure 9(A), and then becomes exposed by penetrating the through hole 25A of the coating material container 21 as shown in Figure 9(B). In the state shown in Figure 9(A), the point at which the coating needle 24 began to descend was defined as t=0, and the state of the tip surface 24Bc of the needle was observed at t=178 milliseconds, t=687 milliseconds, and t=1222 milliseconds.
[0060] Figure 12 is a photograph showing the state of the tip of the coating needle after a certain period of time has elapsed from the moment the coating needle begins to descend in Example 1. The moment when the coating needle 24 begins to descend, that is, the moment when the servo motor 41 and cam 43 begin to rotate, is defined as t=0, and at t=10 milliseconds, the tip surface 24Bc of the coating needle 24 is exposed from the coating material container 21. Figure 12(A) shows the state at t=178 milliseconds, (B) shows the state at t=687 milliseconds, and (C) shows the state at t=1222 milliseconds.
[0061] As shown in Figure 12, the amount of distilled water adhering to the tip surface 24Bc of the coating needle 24 decreases over time. At the time when the coating needle 24 is exposed from the coating material container 21 (t = 10 milliseconds), it is thought that distilled water is adhering to the entire tip surface 24Bc. However, at t = 178 milliseconds in (A), the distilled water has evaporated compared to the time when the coating needle 24 was exposed from the coating material container 21, and distilled water is no longer adhering to a part of the tip portion 24Bb, including the tip surface 24Bc. However, at time (A), more distilled water is adhering to the tip portion 24Bb, including the tip surface 24Bc, compared to times (B) and (C).
[0062] In this embodiment, the same verification as in Example 1 was performed on a coating needle 24 whose arithmetic mean height Sa of the tip surface 24Bc differed from that of Example 1. Specifically, in this embodiment, a coating needle 24 with an arithmetic mean height Sa of the tip surface 24Bc of 0.0360 μm was used. In other words, the coating needle 24 of this embodiment has a smoother tip surface 24Bc compared to the coating needle 24 of Example 1. The diameter of the tip surface 24Bc in this embodiment was 150 μm, the same as that of Example 1.
[0063] Figure 13 is a photograph showing the state of the tip of the coating needle after a certain period of time has elapsed from the moment the coating needle begins to descend in Example 2. In Figure 13, as in Figure 12, t=0 is defined as the moment when the coating needle 24 begins to descend, that is, the moment when the servo motor 41 and cam 43 begin to rotate, and (A) shows the state at t=178 milliseconds, (B) shows the state at t=687 milliseconds, and (C) shows the state at t=1222 milliseconds.
[0064] Comparing Figure 13(A) with Figure 12(A), Figure 13(A) shows a greater amount of distilled water adhering to the tip portion 24Bb, including the tip surface 24Bc, than Figure 12(A). Similarly, comparing Figure 13(B) with Figure 12(B), Figure 13(B) shows a greater amount of distilled water adhering to the tip portion 24Bb than Figure 12(B). Comparing Figure 13(C) with Figure 12(C), Figure 13(C) shows a greater amount of distilled water adhering to the tip portion 24Bb than Figure 12(C). Thus, by increasing the flatness of the tip surface 24Bc (lowering the value of the arithmetic mean height Sa), the amount of distilled water adhering to the tip portion 24Bb, including the tip surface 24Bc, can be increased.
[0065] The results in Figure 13 show that when the value of Sa is constant, it is particularly preferable that t be 178 milliseconds or less. However, there is a little more leeway in the acceptable range of t values than the above. In other words, if the value of t is 687 milliseconds or less, a sufficient amount of distilled water will adhere, and the contact angle of the distilled water with respect to the tip surface 24Bc will increase. Therefore, a sufficient amount of distilled water (coating material 70 containing water) can be applied to the substrate 5, etc.
[0066] In this embodiment, the change in the amount of distilled water adhering to the tip portion 24Bb was observed while changing the arithmetic mean height Sa of the tip surface 24Bc of the coating needle 24. Figure 14 is a photograph showing the change in the appearance of the tip portion of the coating needle after a certain period of time has elapsed from the time the coating needle begins to descend, when the arithmetic mean height of the tip surface of the coating needle is changed in Embodiment 3. In all photographs in Figure 14, the appearance is shown at t = 178 milliseconds, with t = 0 being the time when the coating needle 24 begins to descend, that is, the time when the servo motor 41 and cam 43 begin to rotate. In Figure 14 (A), the arithmetic mean height Sa of the tip surface 24Bc is 0.3845 μm. In Figure 14 (B), the arithmetic mean height Sa is 0.1891 μm. In Figure 14 (C), the arithmetic mean height Sa is 0.1227 μm. In Figure 14(D), the arithmetic mean height Sa is 0.0689 μm. In Figure 14(E), the arithmetic mean height Sa is 0.0360 μm. In Figure 14(F), the arithmetic mean height Sa is 0.0301 μm.
[0067] In Figure 14, the amount of distilled water adhering to the tip portion 24Bb was lowest at (A) and gradually increased towards (F). In other words, it was found that the amount of distilled water adhering increased as the value of the arithmetic mean height Sa of the tip surface 24Bc decreased.
[0068] In Figures 14(A) to (C), where the arithmetic mean height Sa of the tip surface 24Bc of the coating needle 24 exceeds 0.1 μm, the amount of distilled water adhering to the tip portion 24Bb is small even at t = 178 milliseconds. This indicates that evaporation of the distilled water has progressed before t = 178 milliseconds is reached. For this reason, as shown in Figures 14(D) to (F), it is preferable to use a coating needle 24 in which the arithmetic mean height Sa of the tip surface 24Bc is 0.1 μm or less.
[0069] The results in Figure 14 show that it is preferable for the Sa value to be 0.0689 μm or less (0.07 μm or less). However, there is a little more leeway in the acceptable range for the Sa value than the above. In other words, if the Sa value is 0.1 μm or less, a sufficient amount of distilled water will adhere, and the contact angle of the distilled water with respect to the tip surface 24Bc will increase. Therefore, a sufficient amount of distilled water (coating material 70 containing water) can be applied to the substrate 5, etc.
[0070] The coating needle 24 may be processed so that the arithmetic mean height Sa of the tip portion 24Bb other than the tip surface 24Bc is 0.1 μm or less. However, the base portion 24A of the coating needle 24, other than the tip portion 24B, does not need to be treated to reduce the arithmetic mean height Sa (so-called surface roughness) and make the surface flatter. This suppresses the upward movement of distilled water towards the base portion 24A and allows a sufficient amount of distilled water to adhere to the tip portion 24Bb. It is preferable that the arithmetic mean height Sa of the base portion 24A of the coating needle 24 is greater than that of the tip portion 24B. In other words, it is preferable that the base portion 24A has a rougher surface than the tip portion 24B.
[0071] The tip portion 24B preferably has a dimension in the Z direction over which it extends of 3 mm to 8 mm, and more preferably 3 mm to 4 mm. In the front view of Figure 7, the angle between the outer edge of the constant-width portion 24Ba and the outer edge of the tip portion 24Bb is preferably 150° or less, and more preferably 135° or less. This prevents liquid material such as distilled water from being pulled up from the tip portion 24Bb side to the constant-width portion 24Ba side. As a result, the upward movement of distilled water towards the base end portion 24A side is suppressed, and a sufficient amount of distilled water can adhere to the tip portion 24Bb.
[0072] The material of the coating needle 24 is preferably either stainless steel or ceramic, which are generally known. This ensures a sufficient amount of distilled water adheres within a time of 178 milliseconds or less, as described above.
[0073] (Note) The various aspects of this disclosure are summarized below as an appendix.
[0074] (Note 1) A coating needle that can approach the surface of a material to be treated, wherein one end in the direction of extension, which is the tip portion that can approach the surface of the material to be treated, has a tip surface that can follow the surface, and the arithmetic mean height Sa of the tip surface is 0.1 μm or less.
[0075] (Note 2) A coating mechanism comprising: a coating needle that can approach the surface of a material to be processed; a positioning mechanism capable of controlling the relative position of the coating needle with respect to the material to be processed in the vertical direction; and a coating material container capable of storing a coating material to be attached to the coating needle, wherein a through hole is formed in the bottom of the coating material container through which at least a part of the coating needle can pass; the coating needle has a tip surface that can follow the surface at one end in the extending direction, which is a tip portion that can approach the surface of the material to be processed; and the arithmetic mean height Sa of the tip surface is 0.1 μm or less.
[0076] (Note 3) A coating apparatus comprising the coating mechanism described in Note 2 and a holding stand for holding the material to be processed.
[0077] (Note 4) A coating method using the coating mechanism described in Note 2, comprising the steps of: positioning the material to be processed directly below the coating material container; and applying the coating material to the surface of the material to be processed using the coating needle, wherein in the coating step, the coating material attached to the tip of the coating needle is applied to the surface of the material to be processed within 178 milliseconds from the time the coating needle begins to descend, by control of the positioning mechanism.
[0078] (Note 5) The coating method according to Note 4, wherein, in the coating step, the positioning mechanism controls the coating material attached to the tip of the coating needle to be applied to the surface of the material to be treated within 35.2 milliseconds from the time the coating needle begins to descend.
[0079] (Note 6) The coating method according to Note 4 or 5, wherein the coating material is distilled water.
[0080] (Note 7) The coating method according to Note 4 or 5, wherein the coating material is a protein-containing solution.
[0081] (Note 8) A coating method comprising the steps of: placing a material to be processed directly below a coating material container included in a coating mechanism; and applying the coating material to the surface of the material to be processed using the coating mechanism, wherein the coating mechanism comprises: a coating needle that can approach the surface of the material to be processed; a positioning mechanism that can control the relative position of the coating needle with respect to the material to be processed in the vertical direction; and a coating material container capable of storing the coating material to be attached to the coating needle, wherein a through hole is formed in the bottom of the coating material container through which at least a part of the coating needle can pass, and in the coating step, the coating material attached to the tip of the coating needle is attached to the surface of the material to be processed within 178 milliseconds from the time the coating needle begins to descend, under control by the positioning mechanism.
[0082] (Note 9) The coating method according to Note 8, wherein, in the coating step, the positioning mechanism controls the coating material attached to the tip of the coating needle to be applied to the surface of the material to be treated within 35.2 milliseconds from the time the coating needle begins to descend.
[0083] 1 X-axis table, 2 Y-axis table, 3 Z-axis table, 4 coating mechanism, 5 substrate, 6 observation optical system, 7 CCD camera, 8 operation panel, 9 monitor, 10 control computer, 20 coating needle holder, 21 coating material container, 22 holder base, 23 holder lid, 24 coating needle, 24A base end portion, 24B tip end portion, 24Ba constant width portion, 24Bb tip portion, 24Bc tip surface, 25 coating needle fixing plate, 25A through hole, 26 linear guide, 27 spring, 29 elongated hole, 30, 31, 34, 36 reference surface, 33 magnet, 35 movable base, 41 servo motor, 43 cam, 44 bearing, 45 cam connecting plate, 46 movable part, 61 cam surface, 62 upper end flat area, 63 lower end flat area, 70 Coating material, 100 coating device, 410 positioning mechanism.
Claims
1. A coating needle that can approach the surface of a material to be treated, wherein one end in the extending direction, which is the tip portion that can approach the surface of the material to be treated, has a tip surface that can conform to the surface, and the arithmetic mean height Sa of the tip surface is 0.1 μm or less.
2. A coating mechanism comprising: a coating needle that can approach the surface of a material to be processed; a positioning mechanism capable of controlling the relative position of the coating needle with respect to the material to be processed in the vertical direction; and a coating material container capable of storing a coating material to be attached to the coating needle, wherein a through hole is formed in the bottom of the coating material container through which at least a portion of the coating needle can pass; the coating needle has a tip surface that can follow the surface at one end in the extending direction, which is a tip portion that can approach the surface of the material to be processed; and the arithmetic mean height Sa of the tip surface is 0.1 μm or less.
3. A coating apparatus comprising the coating mechanism described in claim 2 and a holding stand for holding the material to be processed.
4. A coating method using the coating mechanism described in claim 2, comprising the steps of: positioning the material to be processed directly below the coating material container; and applying the coating material to the surface of the material to be processed using the coating needle, wherein in the coating step, the coating material attached to the tip of the coating needle is applied to the surface of the material to be processed within 178 milliseconds from the time the coating needle begins to descend, by control of the positioning mechanism.
5. The coating method according to claim 4, wherein, in the coating step, the positioning mechanism controls the coating material attached to the tip of the coating needle to be applied to the surface of the material to be treated within 35.2 milliseconds from the time the coating needle begins to descend.
6. The coating method according to claim 4 or 5, wherein the coating material is distilled water.
7. The coating method according to claim 4 or 5, wherein the coating material is a protein-containing solution.