Plasma mask and plasma treatment method

Abstract

To provide a plasma processing mask that enables at least one of reformation and removal of a surface for a processing object (for example, a surface coating layer of the processing object) without damaging the processing object and in a short time.SOLUTION: A plasma processing mask includes an opening corresponding to a plasma processing region of a processing object, and a flow path through which cooling gas flows. An outlet of the flow path is in communication with the opening.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to plasma processing for performing at least one of modification and removal on a surface coat layer of an object to be processed.

Background Art

[0002] A display device used for operating a navigation device, an audio device, a television receiver, etc. is mounted on a vehicle.

[0003] Conventionally, in a display device mounted on a vehicle, an encoder component for volume adjustment etc. was arranged on a bezel (see, for example, Patent Document 1). In a display device having a bezel, as shown in the partial cross-sectional view of FIG. 1, an encoder component 101 is connected by solder 104 to a circuit board 103 arranged facing the bezel 102.

[0004] However, in a display device mounted on a vehicle, in recent years, a display panel which is an electrostatic touch panel is mounted, and a configuration without a bezel is mainstream. In a display device without a bezel, for example, as shown in the partial cross-sectional view of FIG. 2, an encoder component 201 is fixed by an adhesive 203 to the surface of a display panel 202 including an electrostatic touch panel 202B. An FPC (Flexible Printed Circuits) used to establish an electrical connection between the encoder component 201 and other components, for example, is connected to the encoder component 201.

[0005] The display panel 202 includes a liquid crystal layer 202A, an anti-reflection resin layer 202C, glass 202D, and a surface coat layer 202E in addition to the electrostatic touch panel 202B. Chemical strengthening treatment is applied to the surface of the glass 202D. As an example of the surface coat layer 202E, for example, a structure in which an AG (Anti-Glare) layer, an AR (Anti-Reflective) layer, and an AFP (Anti-Finger Print) layer are laminated in this order from the side closer to the glass 202D can be mentioned.

Prior Art Documents

[0006] [Patent Document 1] Japanese Patent Publication No. 2019-202553 [Overview of the project] [Problems that the invention aims to solve]

[0007] The surface of display panels, including electrostatic touch panels, is coated with a surface coating layer to prevent fingerprints from adhering. This surface coating layer is composed of components that do not adhere to adhesives. Therefore, the surface coating layer must be removed in areas where adhesives are to be applied.

[0008] One possible method for removing the surface coating layer is to partially mask the surface of the display panel when forming the surface coating layer. However, adopting this method would significantly increase costs.

[0009] Therefore, from the perspective of cost reduction, it is desirable to adopt a method of modifying the surface coating layer of the area to be bonded with adhesive using plasma treatment before bonding.

[0010] In plasma processing, heat is generated when plasma is irradiated onto the object being processed. Therefore, if plasma is irradiated onto the object for a long period of time, there is a risk that the object may be damaged.

[0011] For example, common materials like ABS resin can be surface-modified with short-duration plasma irradiation. However, when surface modification requires high energy, such as for surface coating layers, prolonged plasma irradiation is necessary, making it impossible to avoid high temperatures on the material being treated. Therefore, to prevent damage to the material, it becomes necessary to perform plasma irradiation in multiple stages, allowing time for the material's temperature to cool down, which leads to a decrease in productivity.

[0012] In view of the above problems, the present invention aims to provide a plasma treatment mask and a plasma treatment method using the plasma treatment mask that enable at least one of modification and removal of the surface of an object to be treated (for example, the surface coating layer of the object to be treated) without damaging the object and in a short time. [Means for solving the problem]

[0013] An exemplary plasma processing mask of the present invention comprises an opening corresponding to the plasma processing area of ​​the object to be processed, and a flow path for flowing a cooling gas. The outlet of the flow path is in communication with the opening. [Effects of the Invention]

[0014] According to an exemplary version of the present invention, it is possible to modify and remove at least one of the following from the surface of an object to be processed (e.g., the surface coating layer of the object to be processed) in a short time without damaging the object. [Brief explanation of the drawing]

[0015] [Figure 1] Partial cross-sectional view of a display device with a bezel [Figure 2] Partial cross-sectional view of a display device without a bezel [Figure 3] Top view of a plasma processing mask according to the first embodiment. [Figure 4] Cross-sectional view of a plasma processing mask according to the first embodiment. [Figure 5] A flowchart illustrating the plasma processing method using a plasma processing mask according to the first embodiment. [Figure 6] This figure shows the plasma processing mask according to the first embodiment installed on the object to be processed. [Figure 7] This diagram shows the state in which plasma is being irradiated from the plasma head onto the plasma processing area of ​​the object to be processed. [Figure 8] Diagram showing the direction of movement of the plasma head. [Figure 9]Figure showing the state where the object to be processed is air-cooled [Figure 10A] Figure showing the temperature characteristics of the object to be processed when there is air cooling and the temperature characteristics of the object to be processed when there is no air cooling [Figure 10B] Figure showing the temperature characteristics of the object to be processed when there is air cooling and the temperature characteristics of the object to be processed when there is no air cooling [Figure 11] Figure showing the relationship between the cooling time, the flow rate of the cooling gas, and the temperature of the object to be processed after air cooling [Figure 12] Top view of the plasma processing mask according to the second embodiment [Figure 13] Cross-sectional view of the plasma processing mask according to the second embodiment

Mode for Carrying Out the Invention

[0016] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings.

[0017] <First Embodiment> FIG. 3 is a top view of the plasma processing mask according to the first embodiment. FIG. 4 is a cross-sectional view of the plasma processing mask according to the first embodiment when cut along the AA cut surface shown in FIG. 3.

[0018] The plasma processing mask 1 of the present embodiment includes a first heat conductive member 2, a second heat conductive member 3, and a liner 4.

[0019] The materials of the first heat conductive member 2 and the second heat conductive member 3 are metals with high thermal conductivity such as aluminum, aluminum alloy, copper, and copper alloy. Thereby, heat can be efficiently released from the object to be processed.

[0020] The material of the liner 4 is a rubber-based resin material such as urethane or silicone that has appropriate flexibility. This prevents damage to the object to be processed by contact with the plasma processing mask 1, and improves adhesion to the object to be processed, preventing plasma leakage. It is desirable that the rubber-based resin material used as the liner 4 contains a heat-conducting filler such as alumina. When a heat-conducting filler is mixed in, heat from the object to be processed can be efficiently conducted to the second heat-conducting member 3 via the liner 4.

[0021] The plasma processing mask 1 has a structure in which a first heat conductive member 2, a second heat conductive member 3, and a liner 4 are stacked in the vertical direction. Furthermore, the plasma processing mask 1 is provided with an opening 5 corresponding to the plasma processing area of ​​the object to be processed.

[0022] Since the opening 5 is assumed to be a cylindrical member to be processed, it has a C-shape when viewed from above. However, the shape of the opening 5 is not limited to a C-shape; it can be made into an appropriate shape according to the shape of the object to be processed.

[0023] Furthermore, by stacking the first heat conductive member 2 and the second heat conductive member 3 in the vertical direction, two flow channels 6 and 7 are formed in the plasma processing mask 1 by grooves provided in the first heat conductive member 2 and the second heat conductive member 3, respectively. In other words, the plasma processing mask 1 is equipped with flow channels 6 and 7. Flow channels 6 and 7 are channels for flowing a cooling gas. For example, air can be used as the cooling gas. However, the cooling gas may be a gas other than air.

[0024] Unlike this embodiment, it is possible to have only one flow path, but by providing multiple flow paths as in this embodiment, it becomes possible to cool the entire object while suppressing the temperature distribution, even when the plasma processing area of ​​the object to be processed is extensive. Note that when providing multiple flow paths, the number of flow paths is not limited to two; it may be three or more.

[0025] The outlet 61 of channel 6 and the outlet 71 of channel 7 are connected to the opening 5. By introducing cooling gas into the inlet 62 of channel 6 and the inlet 72 of channel 7, the cooling gas is blown out into the opening 5. This cooling gas suppresses the temperature rise of the object being treated. Therefore, by using the plasma treatment mask 1, it is possible to modify and remove at least one of the surface coating layer of the object being treated in a short time without damaging the object.

[0026] In the plasma processing mask 1, a stepped portion 63 is provided in the flow path 6, and a stepped portion 73 is provided in the flow path 7. The stepped portion 63 makes it easy to position the outlet 61 at a desired position in the vertical direction, and the stepped portion 73 makes it easy to position the outlet 71 at a desired position in the vertical direction.

[0027] In the plasma processing mask 1, the vertical positions of the outlets 61 and 71 are positioned near the object to be processed. This allows for efficient cooling of the object to be processed by blowing cooling gas onto it.

[0028] The second heat conduction member 3 includes a heat sink 8. That is, the plasma processing mask 1 includes a heat sink 8. The heat sink 8 releases the heat generated by the object being processed into the atmosphere. The heat sink 8 further suppresses the temperature rise of the object being processed.

[0029] In the plasma processing mask 1, a portion of the opening 5 is located between the outlet 61 and the heat sink 8, and another portion of the opening 5 is located between the outlet 71 and the heat sink 8. This arrangement allows the cooling gas to contribute not only to the cooling of the object being processed but also to the cooling of the heat sink 8. Therefore, efficient use of the cooling gas becomes possible.

[0030] Next, we will describe a plasma treatment method using the plasma treatment mask 1. Figure 5 is a flowchart illustrating the plasma treatment method using the plasma treatment mask 1.

[0031] First, the operator places the plasma processing mask 1 on the object to be processed 9 (step S1). Once the plasma processing mask 1 is placed on the object to be processed 9, the plasma processing mask 1 and the object to be processed 9 will be in the state shown in Figure 6. The object to be processed 9 is, for example, a display panel including a surface coating layer 9E. An example of a display panel including a surface coating layer 9E is a display panel in which a liquid crystal layer 9A, an electrostatic touch panel 9B, an anti-reflective resin layer 9C, glass 9D, and a surface coating layer 9E are laminated in that order. The surface of the glass 9D is chemically strengthened. An example of a surface coating layer 9E is a structure in which an AG layer, an AR layer, and an AFP layer are laminated in the order of AG layer, AR layer, and AFP layer from the side closest to the glass 9D.

[0032] In step S2 following step S1, plasma P2 is irradiated from the plasma head P1 onto the plasma processing area of ​​the object to be processed 9, as shown in Figure 7. The plasma head P1 is provided in the plasma irradiation device. As with the plasma processing mask 1, by shaping the liner 4 so that its side surface is further away from the plasma processing area of ​​the object to be processed 9 than the side surfaces of the first heat conductive member 2 and the second heat conductive member 3, the degree of agreement between the side surfaces of the first heat conductive member 2 and the second heat conductive member 3 and the outer edge of the plasma processing area of ​​the object to be processed 9 can be increased. On the other hand, unlike the plasma processing mask 1, if the side surfaces of the first heat conductive member 2 and the second heat conductive member 3 and the side surface of the liner 4 are flush, the plasma will weaken near the side surfaces of the first heat conductive member 2 and the second heat conductive member 3, and the surface of the object to be processed 9 will not be modified or removed by the plasma.

[0033] Since the plasma outlet of the plasma head P1 is smaller than the plasma processing area c, the plasma head P1 is moved in the direction D1 along the arc of the opening 5, as shown in Figure 8.

[0034] In step S3, following step S2, the plasma irradiation device determines whether the number of plasma irradiations has reached a set value. If the number of plasma irradiations reaches the set value, the series of plasma processing is terminated.

[0035] On the other hand, if the number of plasma irradiations has not reached the set value, the process proceeds to step S4, where, as shown in Figure 9, the cooling gas introduced from inlet 62 moves along the flow direction D2 and is blown out from outlet 61, and the cooling gas introduced from inlet 72 moves along the flow direction D3 and is blown out from outlet 71. As a result, the object to be processed 9 is air-cooled by the cooling gas.

[0036] Cooling gas is introduced into inlets 62 and 72 at a set flow rate. Once the set cooling time has elapsed, the air cooling in step S4 is terminated, and the process returns to step S2.

[0037] For example, if the object to be processed 9 is a display panel with the configuration shown in Figure 2, plasma processing that ensures the desired adhesion can be achieved by setting the movement speed of the plasma head P1 to 50 mm / second and the number of plasma irradiations to 4.

[0038] Figures 10A and 10B show the temperature characteristics T1 of the object 9 to be processed with air cooling and T2 of the object 9 to be processed without air cooling. Figure 10A shows an example where, if a series of plasma treatments are performed for the same processing time, the temperature of the object 9 to be processed exceeds the acceptable range when there is no air cooling. Figure 10B shows an example where, in order to prevent the temperature of the object 9 to be processed from exceeding the acceptable range, the series of plasma treatments takes too long when there is no air cooling. In the example shown in Figure 10B, the time required for the series of plasma treatments can be shortened when air cooling is present compared to when there is no air cooling.

[0039] The optimal number of plasma irradiations varies depending on the type of object 9 being treated. Therefore, in a plasma treatment method using a plasma treatment mask 1, it is desirable to change the number of plasma irradiations according to the object 9 being treated.

[0040] Furthermore, as shown in Figure 11, the peak temperature of the object to be processed 9 changes depending on the supply time (cooling time) and the flow rate of the cooling gas. Therefore, in the plasma processing method using the plasma processing mask 1, it is desirable to change the supply time (cooling time) and the flow rate of the cooling gas according to the required processing time. Note that the required processing time changes depending on, for example, the production situation.

[0041] <Second Embodiment> Figure 12 is a top view of the plasma processing mask according to the second embodiment. Figure 13 is a cross-sectional view of the plasma processing mask according to the second embodiment when cut along the AA cross-section shown in Figure 12.

[0042] In the plasma processing mask 10 of this embodiment, the same reference numerals are used for parts identical to those in the plasma processing mask 1 of the first embodiment, and detailed descriptions are omitted.

[0043] The plasma processing mask 10 of this embodiment differs from the plasma processing mask 1 of the first embodiment in the shape of the flow channels 6 and 7 and the orientation of the fins of the heat sink 8.

[0044] In the plasma processing mask 10, a stepped portion 63 is provided in the flow path 6, and a stepped portion 73 is provided in the flow path 7. The stepped portion 63 makes it easy to position the outlet 61 at a desired position in the vertical direction, and the stepped portion 73 makes it easy to position the outlet 71 at a desired position in the vertical direction.

[0045] In the plasma processing mask 10, the vertical positions of the outlets 61 and 71 are positioned opposite the grooves formed between the fins of the heat sink 8. This improves the heat dissipation capacity of the heat sink 8 by blowing cooling gas onto it.

[0046] Furthermore, in the plasma processing mask 10, multiple fins of the heat sink 8 extend along the direction of outflow of cooling gas from outlets 61 and 71. This makes it easier for the cooling gas to enter grooves formed between the fins of the heat sink 8, thereby further improving the heat dissipation capacity of the heat sink 8.

[0047] The plasma treatment method using the plasma treatment mask 10 is the same as the plasma treatment method using the plasma treatment mask 1, so the explanation will be omitted.

[0048] <Notes> The various technical features disclosed in the embodiments for carrying out the invention as described herein can be modified in various ways without departing from the spirit of the technical creation. Furthermore, the multiple embodiments and modifications disclosed in the embodiments for carrying out the invention as described herein may be combined to the extent possible. [Explanation of symbols]

[0049] 1. 10 Plasma treatment masks 2. First heat conductive member 3. Second heat conductive member 4 Liners 5 Openings 6, 7 channels 61, 71 Outlet 62, 72 Inlet 63, 73 Stepped section 8 Heatsink 9. Objects to be processed 9A liquid crystal layer 9B Capacitive Touch Panel 9C Anti-reflection resin layer 9D Glass 9E Surface Coat Layer P1 Plasma Head P2 Plasma

Claims

1. An opening corresponding to the plasma processing area of ​​the object to be processed, It is equipped with a flow path for circulating cooling gas, The object to be processed is a display panel including a surface coating layer. The outlet of the flow path is a plasma processing mask that communicates with the opening.

2. An opening corresponding to the plasma processing area of ​​the object to be processed, It is equipped with a flow path for circulating cooling gas, A stepped portion is provided in the aforementioned flow path. The outlet of the flow path is a plasma processing mask that communicates with the opening.

3. An opening corresponding to the plasma processing area of ​​the object to be processed, A passage for flowing cooling gas, Equipped with a heatsink, The outlet of the flow path is a plasma processing mask that communicates with the opening.

4. The plasma processing mask according to claim 3, wherein at least a portion of the opening is located between the outlet and the heat sink.

5. The heat sink is equipped with multiple fins, The plasma processing mask according to claim 4, wherein the plurality of fins extend along the direction of outflow of the cooling gas from the outlet.

6. A plasma processing mask according to any one of claims 1 to 5, comprising a plurality of the aforementioned flow channels.

7. A step of installing the plasma processing mask according to any one of claims 1 to 6 on the object to be processed, The process of irradiating the plasma processing area with plasma, A plasma treatment method comprising the following features.

8. The plasma treatment method according to claim 7, wherein the number of plasma irradiations is changed according to the object to be treated.

9. Depending on the required processing time, the supply time and flow rate of the cooling gas supplied to the flow path are determined. A plasma treatment method according to claim 7 or claim 8, wherein the quantity is changed.

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