JP2019057462A - Plasma processing apparatus - Google Patents

Abstract

To provide a plasma processing apparatus of which an irradiation range of a plasma is small.SOLUTION: A plasma processing apparatus irradiating a plasma to a region R1 requiring an irradiation of the plasma from an object 200, comprises: a plasma irradiation pipe 5 irradiating the plasma; and an inactive gas irradiation pipe 6 irradiating an inactive gas. By blocking the movement of the plasma irradiated to a direction inclined to a plasma irradiation direction from the plasma irradiated from the plasma irradiation pipe 5 by setting the direction toward the region R1 from the plasma irradiation pipe 5 as the plasma irradiation direction with the inactive gas irradiated from the inactive gas irradiation pipe 6, a movement direction of the plasma is closed to the direction toward the region R1.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a plasma processing apparatus.

  An in-vehicle sensor such as a pressure sensor is fixed to a base material made of PBT (polybutylene terephthalate), PPS (polyphenylene sulfide), or the like via an adhesive made of epoxy, silicone, or the like. Thus, when fixing a vehicle-mounted sensor, before apply | coating an adhesive agent to a base material, plasma is irradiated to a base material and the surface of a base material is improved. Thereby, the adhesive force of a base material and an adhesive agent can be improved.

  However, since heat is generated when the plasma is irradiated, there is a possibility that the bleed is generated by the heat and the adhesion is reduced. Therefore, in order to suppress the generation of bleed due to heat, it is preferable to selectively irradiate only the necessary region with plasma. In order to irradiate only a necessary region with plasma, it is necessary to reduce the plasma irradiation range.

  In this regard, for example, Patent Document 1 proposes a plasma processing apparatus in which the gas flow path inside the discharge tube is narrowed in order to reduce the plasma irradiation range.

JP-A-9-232293

  However, even if the gas flow path inside the discharge tube is narrowed, the plasma spreads isotropically from the nozzle and is irradiated, so the irradiation range becomes wider in proportion to the distance between the nozzle and the irradiation target.

  In view of the above points, an object of the present invention is to provide a plasma processing apparatus having a small plasma irradiation range.

  In order to achieve the above object, according to the first aspect of the present invention, there is provided a plasma processing apparatus for irradiating a region (R1) of the object (200) where plasma irradiation is required, wherein the plasma is irradiated with plasma. Plasma provided with an irradiation tube (5) and inert gas irradiation tubes (6, 9) for irradiating an inert gas, with the direction from the plasma irradiation tube toward the region being the plasma irradiation direction, Of these, the movement of the plasma irradiated in the direction inclined with respect to the plasma irradiation direction is blocked by the inert gas irradiated from the inert gas irradiation tube, thereby bringing the plasma movement direction closer to the region. .

  Thus, the plasma irradiation range can be reduced by blocking the movement of the plasma with an inert gas that does not react with the plasma and suppressing the isotropic spread of the plasma.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows an example of a corresponding relationship with the specific means as described in embodiment mentioned later.

It is a figure which shows the structure of the plasma processing apparatus concerning 1st Embodiment. It is an expanded sectional view of a plasma irradiation tube and an inert gas irradiation tube shown in FIG. FIG. 3 is a sectional view taken along line III-III in FIG. 2. It is a figure which shows operation | movement of the plasma processing apparatus concerning 1st Embodiment. It is a figure which shows operation | movement of the conventional plasma processing apparatus. It is sectional drawing of the plasma processing apparatus concerning 2nd Embodiment, Comprising: It is a figure corresponded in FIG. 3 of 1st Embodiment. It is sectional drawing of the plasma processing apparatus concerning 3rd Embodiment, Comprising: It is a figure corresponded in FIG. 2 of 1st Embodiment. It is sectional drawing of the plasma processing apparatus concerning 4th Embodiment, Comprising: It is a figure corresponded in FIG. 2 of 1st Embodiment. It is sectional drawing of the plasma processing apparatus concerning 5th Embodiment, Comprising: It is a figure corresponded in FIG. 2 of 1st Embodiment. It is sectional drawing of the modification of 5th Embodiment, Comprising: It is a figure corresponded in FIG. 2 of 1st Embodiment. It is sectional drawing of the plasma processing apparatus concerning other embodiment, Comprising: It is a figure corresponded in FIG. 2 of 1st Embodiment. It is sectional drawing of the plasma processing apparatus concerning other embodiment, Comprising: It is a figure corresponded in FIG. 2 of 1st Embodiment. It is sectional drawing of the plasma processing apparatus concerning other embodiment, Comprising: It is a figure corresponded in FIG. 2 of 1st Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other will be described with the same reference numerals.

(First embodiment)
A first embodiment will be described. The plasma processing apparatus of this embodiment is used when, for example, a vehicle-mounted pressure sensor is fixed to a case made of PBT, PPS, or the like with an adhesive made of epoxy, silicone, or the like.

  As shown in FIG. 1, the plasma processing apparatus 100 includes a torch 1, a power source 2, a gas supply unit 3, and a gas supply unit 4. An electrode (not shown) is disposed inside the torch 1, and an arc is generated when a voltage is applied from the power source 2 to the torch 1. Further, gas is supplied to the torch 1 from the gas supply unit 3. The arc generated by applying the voltage is emitted from the plasma irradiation tube 5 disposed at the tip of the torch 1 as a plasma jet by the gas supplied from the gas supply unit 3. In order to cool the plasma gas, cooling water flows through the torch 1 through a line or the like (not shown).

  The torch 1 is also supplied with a gas from a gas supply unit 4 different from the gas supply unit 3, and the gas supplied from the gas supply unit 4 is disposed at the tip of the torch 1. The inert gas irradiation tube 6 is injected. The inert gas irradiation tube 6 is for controlling the irradiation range of the plasma emitted from the plasma irradiation tube 5.

  The inert gas irradiation tube 6 is located in the vicinity of the plasma irradiation tube 5 so that the portion of the inert gas irradiation tube 6 where the inert gas is emitted is adjacent to the portion of the plasma irradiation tube 5 where the plasma is emitted. Has been placed.

  As shown in FIGS. 2 and 3, in this embodiment, the plasma irradiation tube 5 has a cylindrical shape, and a plasma flow path 7 is formed inside the plasma irradiation tube 5. Further, the inert gas irradiation tube 6 has a cylindrical shape with a radius larger than that of the plasma irradiation tube 5, and the plasma irradiation tube 5 is arranged so that the axes of the plasma irradiation tube 5 and the inert gas irradiation tube 6 coincide with each other. Arranged inside the inert gas irradiation tube 6.

  Further, in the present embodiment, the plasma irradiation tube 5 and the inert gas irradiation tube 6 are aligned at the positions of the tips from which the gas is injected. The axial direction of the plasma irradiation tube 5 is parallel to the plasma irradiation direction described later.

  In the inert gas irradiation tube 6, an inert gas flow path 8 is formed in a portion sandwiched between the outer wall surface of the plasma irradiation tube 5 and the inner wall surface of the inert gas irradiation tube 6, and a gas supply unit The gas supplied from 4 flows through the inert gas flow path 8.

  As the plasma gas, for example, nitrogen, oxygen, air, argon, hydrogen, helium, or the like can be used. As the inert gas, for example, a gas that does not easily react with the plasma gas can be selected from nitrogen, oxygen, air, argon, hydrogen, helium, and the like.

  The operation of the plasma processing apparatus 100 will be described with reference to FIG. First, a workpiece 200 that is an object to be irradiated with plasma is prepared, and a plasma irradiation tube 5 and an inert gas irradiation tube 6 are arranged above a region R1 that is a region where plasma irradiation is necessary. Here, a direction from the plasma irradiation tube 5 toward the region R1 is a plasma irradiation direction.

  In the present embodiment, the movement of the plasma irradiated in the direction inclined with respect to the plasma irradiation direction out of the plasma irradiated from the plasma irradiation tube 5 is blocked by the inert gas irradiated from the inert gas irradiation tube 6. Thus, the moving direction of the plasma is brought closer to the direction toward the region R1.

  Specifically, after irradiation of the inert gas from the inert gas irradiation tube 6 to the workpiece 200 is started, the workpiece 200 is irradiated with plasma gas from the plasma irradiation tube 5. As a result, the isotropic movement of the plasma gas is blocked by the flow of the inert gas that has started irradiation, and the spot diameter of the plasma gas is reduced. Thereby, it is possible to suppress the region R2 of the workpiece 200 that is irradiated with plasma from spreading out of the region R1, and to irradiate the plasma only on a necessary portion.

  In the conventional plasma processing apparatus, as shown in FIG. 5, the plasma irradiated from the plasma irradiation tube 5 spreads isotropically. For this reason, the region R3 to which the plasma is irradiated becomes larger in proportion to the distance between the plasma irradiation tube 5 and the workpiece 200, and there is a possibility that the region that is greatly spread outside the region R1 is irradiated with the plasma.

  On the other hand, in the present embodiment, as described above, anisotropy is imparted to the plasma moving direction, and the plasma irradiation range is reduced. Thereby, when irradiating plasma to the base material of a complicated shape, it becomes possible to irradiate plasma only to a necessary part and to suppress interference with other parts.

  Note that the flow rates of the plasma gas and the inert gas may be equal to each other, or one of them may be greater than the other. Similarly, the flow pressure and the flow path cross-sectional area may be the same for the plasma gas and the inert gas, or either one may be larger than the other.

  Further, the region R2 becomes wider as the distance between the plasma irradiation tube 5 and the workpiece 200 becomes longer, and the region R2 becomes narrower as this distance becomes shorter. Therefore, the width of the region R2 can be controlled by changing this distance. it can. Further, the region R2 can be narrowed by reducing the radius of the plasma irradiation tube 5.

(Second Embodiment)
A second embodiment will be described. In this embodiment, the configuration of the inert gas irradiation tube 6 is changed with respect to the first embodiment, and the other parts are the same as those in the first embodiment. Therefore, only the parts different from the first embodiment will be described. To do.

  As shown in FIG. 6, in this embodiment, a plurality of pipes 9 are arranged between the outer wall surface of the plasma irradiation tube 5 and the inner wall surface of the inert gas irradiation tube 6. The pipe 9 has a cylindrical shape, and is arranged at intervals in the circumferential direction of the plasma irradiation tube 5 so as to coincide with the plasma irradiation tube 5 and the inert gas irradiation tube 6 in the axial direction. The inside of the pipe 9 is an inert gas flow path 8.

  As described above, the plurality of pipes 9 are arranged at intervals inside the inert gas irradiation pipe 6 and the inside of the pipe 9 is used as the inert gas flow path 8, so that it is inactive compared to the first embodiment. The cross-sectional area of the gas flow path 8 is reduced. Thereby, even if the supply amount of the inert gas is the same, the flow velocity is increased, so that the flow of plasma gas can be suppressed with a small gas supply amount.

  The plasma processing apparatus 100 may not include the inert gas irradiation tube 6 but may include only the pipe 9 as the inert gas irradiation tube.

(Third embodiment)
A third embodiment will be described. In this embodiment, the configuration of the inert gas irradiation tube 6 is changed with respect to the first embodiment, and the other parts are the same as those in the first embodiment. Therefore, only the parts different from the first embodiment will be described. To do.

  In this embodiment, the flow direction of the inert gas inside the inert gas irradiation tube 6 is a direction inclined with respect to the axial direction of the plasma irradiation tube 5. Specifically, as shown in FIG. 7, a spiral slit 10 is formed on the inner wall of the inert gas irradiation tube 6, whereby the flow of the inert gas inside the inert gas irradiation tube 6 is reduced. It becomes spiral.

  In such a configuration, the isotropic spread of the plasma gas can be further suppressed, and the plasma irradiation range can be further reduced.

(Fourth embodiment)
A fourth embodiment will be described. In this embodiment, a cooling device is added to the first embodiment, and the other parts are the same as those in the first embodiment. Therefore, only the parts different from the first embodiment will be described.

  As shown in FIG. 8, in the present embodiment, a cooling device 11 is disposed outside the inert gas irradiation tube 6. The cooling device 11 is for cooling the inert gas inside the inert gas irradiation tube 6 to suppress the reaction between the inert gas and the plasma gas.

  As the inert gas, a gas that does not easily react with the plasma gas is selected, but by cooling the inert gas in this way, the inert gas becomes more difficult to react with the plasma gas. Thereby, the isotropic spread of the plasma gas can be further suppressed by using the inert gas, and the plasma irradiation range can be further reduced.

(Fifth embodiment)
A fifth embodiment will be described. In this embodiment, a magnetic field application device is added to the first embodiment, and the other parts are the same as those in the first embodiment. Therefore, only the parts different from the first embodiment will be described.

  As shown in FIG. 9, in this embodiment, a coil 12 is disposed as a magnetic field applying device that applies a magnetic field to plasma gas moving inside the plasma irradiation tube 5. The coil 12 is wound around the plasma irradiation tube 5, and a magnetic field in the axial direction of the plasma irradiation tube 5 is applied to the plasma gas inside the plasma irradiation tube 5 by passing a current from the power source (not shown) to the coil 12.

  By applying a magnetic field to the plasma gas in this way, the straightness of the plasma gas can be improved and the irradiation range of the plasma gas can be further reduced.

  As shown in FIG. 10, the magnetic field application device may be composed of a magnet 13 disposed outside the plasma irradiation tube 5.

(Other embodiments)
In addition, this invention is not limited to above-described embodiment, In the range described in the claim, it can change suitably.

  For example, in the first to fifth embodiments, the positions of the end portions of the plasma irradiation tube 5 and the inert gas irradiation tube 6 are aligned, but as shown in FIG. 11, the plasma irradiation tube 5 and the inert gas irradiation. The end of the plasma irradiation tube 5 may protrude beyond the end of the inert gas irradiation tube 6 in the axial direction of the tube 6. Further, the end of the inert gas irradiation tube 6 may protrude from the end of the plasma irradiation tube 5.

  Further, the inert gas irradiation tube 6 may be inclined with respect to the plasma irradiation tube 5. For example, as shown in FIG. 12, the inert gas irradiation tube 6 may have a truncated cone shape, and the inert gas may be irradiated from the outside in the radial direction of the plasma irradiation tube 5 toward the inside. Moreover, the slit 10 may be formed in the inside of the inert gas irradiation tube 6 having a truncated cone shape similarly to the third embodiment, and the flow of the inert gas may be spiral.

  The plasma processing apparatus 100 may include a flow rate control device that controls the flow rate of the inert gas inside the inert gas irradiation tube 6. For example, as shown in FIG. 13, an electromagnetic valve 14 is arranged as a flow control device inside the inert gas irradiation tube 6, and the plasma is generated by opening and closing the electromagnetic valve 14 to adjust the irradiation amount of the inert gas. The area of the irradiated region R2 can be controlled.

5 Plasma irradiation tube 6 Inert gas irradiation tube 9 Piping

Claims (10)

A plasma processing apparatus for irradiating a target region (200) with plasma to a region (R1) that needs to be irradiated with plasma,
A plasma irradiation tube (5) for irradiating plasma;
An inert gas irradiation tube (6, 9) for irradiating an inert gas;
The direction from the plasma irradiation tube toward the region is a plasma irradiation direction,
Of the plasma irradiated from the plasma irradiation tube, the movement of the plasma irradiated in a direction inclined with respect to the plasma irradiation direction is blocked by the inert gas irradiated from the inert gas irradiation tube, A plasma processing apparatus for bringing a moving direction of plasma close to a direction toward the region.   The plasma processing apparatus according to claim 1, wherein an axial direction of the plasma irradiation tube is parallel to the plasma irradiation direction.   The plasma processing apparatus according to claim 1, wherein a portion of the inert gas irradiation tube from which an inert gas is injected is disposed adjacent to a portion of the plasma irradiation tube from which plasma is emitted. The plasma irradiation tube and the inert gas irradiation tube are both cylindrical.
The plasma processing apparatus according to any one of claims 1 to 3, wherein the plasma irradiation tube is arranged inside the inert gas irradiation tube.   The plasma processing apparatus according to any one of claims 1 to 3, wherein a plurality of the inert gas irradiation tubes are arranged on an outer wall surface of the plasma irradiation tube.   The plasma processing according to any one of claims 1 to 5, wherein a direction of an inert gas flow inside the inert gas irradiation tube is a direction inclined with respect to an axial direction of the plasma irradiation tube. apparatus.   The plasma processing apparatus according to any one of claims 1 to 6, wherein a flow of the inert gas inside the inert gas irradiation tube is spiral.   The plasma processing apparatus according to claim 1, further comprising a cooling device (11) that cools the inert gas inside the inert gas irradiation tube.   The plasma processing apparatus according to any one of claims 1 to 8, further comprising a magnetic field applying device (12, 13) that applies a magnetic field in an axial direction of the plasma irradiation tube to plasma moving inside the plasma irradiation tube.   The plasma processing apparatus according to any one of claims 1 to 9, further comprising a flow rate control device (14) for controlling a flow rate of the inert gas inside the inert gas irradiation tube.

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