Plasma treatment apparatus, plasma treatment method

Abstract

To provide a plasma treatment apparatus that gives high adhesion force between a resin member and a metal layer of a member surface, and strongly connects them, and a plasma treatment method.SOLUTION: A plasma treatment apparatus 1 has a holding table 4 that holds a substrate body 22 to be irradiated with plasma, a holding side circuit 13 that applies a holding side voltage to the held substrate body 22, a gas introduction section 15 that introduces gas into a vacuum chamber 2, an FPG 3 that converts the gas into plasma, a plasma side circuit 14 constituted such that a plasma side voltage is applied to the FPG 3, and the holding side circuit 13 is set so that the time for applying the holding side voltage to the substrate body 22 and the time for applying the plasma side voltage to the FPG 3 by the plasma side circuit 14 are separate. The plasma side circuit 14 is equipped with an application time adjustment section to ensure that the time for the plasma side circuit 14 to apply the plasma side voltage is shorter than the time for the holding side voltage to be applied to the holding side circuit 13.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an apparatus and method for manufacturing a resin product having a metal layer formed on the surface of the resin. [Background technology]

[0002] Low-dielectric resins have begun to be used in various circuit boards, such as circuit boards with low transmission loss that are compatible with millimeter waves or microwaves. Examples of low-dielectric resins include liquid crystal polymers (LCPs) and fluororesins such as polytetrafluoroethylene (PTFE). However, resin materials such as LCP and PTFE have problems in that they do not adhere well to each other and to copper, which is used as a wiring material. For this reason, techniques are known that chemically roughen the surface of the circuit board substrate or form irregularities on the surface of the copper foil that is to be adhered to the substrate, thereby improving the physical adhesion between the resin substrate and the copper.

[0003] However, when the surface of a resin substrate is chemically roughened and a metal such as copper is formed on the surface of the substrate, the roughness of the substrate surface increases the transmission loss of the circuit board. On the other hand, when copper is attached to the surface of the substrate using an adhesive, the adhesive layer itself becomes a cause of the transmission loss of the circuit board. When copper is formed on the surface of the substrate by plating, the adhesion between the substrate and the copper is not sufficient. Another possible method is to irradiate the PTFE substrate with atmospheric plasma to activate the surface, replace the fluorine in the PTFE substrate with hydroxyl groups derived from moisture in the air, and adhere copper to the surface of the PTFE substrate to obtain a laminate of the PTFE substrate and copper.

[0004] However, even if the PTFE substrate is irradiated with atmospheric plasma, the contact angle of the PTFE substrate with water is at most about 50°. When copper is adhered to the surface of the PTFE substrate, the degree of adhesion between the PTFE substrate and copper is about 0.2 to 0.4 N / mm. Therefore, in the process of forming a copper circuit pattern on the PTFE substrate, the copper may peel off from the PTFE substrate. In addition, if heat is applied to the PTFE substrate in the process of forming the circuit pattern, the degree of adhesion between the PTFE substrate and copper will further decrease. Furthermore, since the surface of the PTFE substrate is modified for about 24 hours, it is necessary to quickly adhere the copper to the surface of the PTFE substrate, which has been a constraint on the production of circuit boards.

[0005] A conventional technique is known in which the surface of a substrate is cleaned with a high-energy beam in a vacuum and then ionized water vapor is irradiated onto the surface of the substrate to adsorb hydroxyl groups onto the surface of the substrate (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 9-3220 Summary of the Invention [Problem to be solved by the invention]

[0007] However, because the energy of ionized water vapor is strong, the once adsorbed hydroxyl groups are again detached from the surface of the substrate when the surface of the substrate is irradiated with other water vapor ions. Therefore, in the invention described in Patent Document 1, the contact angle between the surface of the substrate and water is about 40°. And, in the invention described in Patent Document 1, there is a problem that it is difficult to firmly attach a metal to the surface of a resin member.

[0008] The present application has been made in consideration of the above circumstances, and has as its objective the provision of a plasma processing apparatus and a plasma processing method that can impart high hydrophilicity to the hydrophobic surface of a resin for a long period of time, provide high adhesion between a resin component and a metal layer on the component surface, and firmly bond them together. [Means for solving the problem]

[0009] In order to solve such a problem, the invention described in claim 1 is a plasma processing apparatus that irradiates a surface of a resin present in a chamber with plasma to improve the wettability of the surface of the resin, the plasma processing apparatus having a holding section that holds the resin to be irradiated with the plasma, and a holding side circuit that applies a holding side voltage as a DC voltage to the held resin, a gas introduction section that introduces gas into the chamber, and a plasma irradiation device that converts the gas into plasma. The plasma side circuit is configured to apply a plasma side voltage as a DC voltage to the plasma irradiation device, and the holding side circuit is set so that the time for which the holding side voltage is applied and the time for which the plasma side circuit applies the plasma side voltage to the plasma irradiation device are separate, and the plasma side circuit is characterized in that it has an application time adjustment section for setting the time for which the plasma side circuit applies the plasma side voltage to be shorter than the time for which the holding side voltage is applied to the holding side circuit.

[0010] The invention described in claim 2 is characterized in that, in addition to the configuration described in claim 1, the plasma side circuit is set so that the time for applying the holding side voltage and the time for applying the plasma side voltage are separate for the process of imparting hydroxyl groups to a resin in a state in which at least a portion of the atoms constituting the resin have been released by irradiating the resin with plasma through the plasma side circuit.

[0011] The invention described in claim 3 is characterized in that, in addition to the configuration described in claim 1 or 2, the application time adjustment unit of the plasma side circuit is a switch for on / off control of the application of the plasma side voltage to the plasma irradiation device.

[0012] The invention described in claim 4 is characterized in that, in addition to the configuration described in any one of claims 1 to 3, the holding side circuit applies the holding side voltage independently of the plasma side circuit in the process of introducing the gas into the chamber, converting the gas into plasma, and irradiating the surface of the resin.

[0013] The invention described in claim 5 is characterized in that, in addition to the configuration described in any one of claims 1 to 4, the plasma side circuit applies a positive voltage as the plasma side voltage to the plasma irradiation device, and the holding side circuit applies a positive voltage as the holding side voltage to the resin.

[0014] The invention described in claim 6 is characterized in that, in addition to the configuration described in any one of claims 1 to 5, the holding side circuit applies the holding side voltage to at least a part of the holding portion depending on the position where the resin is present.

[0015] The invention described in claim 7 is a plasma processing method comprising a chamber in which a resin to be irradiated with plasma is accommodated, a holding part for holding the resin to be irradiated with the plasma, a holding circuit for applying a holding side voltage as a DC voltage to the held resin, a gas inlet part for introducing gas into the chamber, and a plasma irradiation device for plasmatizing the gas, and a plasma side circuit configured to apply a plasma side voltage as a DC voltage to the plasma irradiation device, and irradiating the surface of the resin present in the chamber with plasma to improve the wettability of the surface of the resin, wherein the holding side circuit is set so that the time for which the holding side voltage is applied to the resin to impart hydroxyl groups and the time for which the plasma side circuit applies the plasma side voltage to the plasma irradiation device are separate, and the plasma side circuit is provided with an application time adjustment part for setting the time for which the plasma side circuit applies the plasma side voltage to be shorter than the time for which the holding side voltage is applied to the holding side circuit. Effect of the Invention

[0016] According to the inventions described in claims 1 and 7, the time for applying the holding side voltage to the resin held in the holding part of the holding side circuit that applies the holding side voltage as a DC voltage to the resin to be irradiated with plasma in order to impart hydroxyl groups to the resin is set separately from the time for applying the plasma side voltage to the plasma irradiation device of the plasma side circuit that is configured to apply the plasma side voltage as a DC voltage to the plasma irradiation device that turns the gas introduced by the gas introduction part into plasma, so that the timing at which the plasma irradiation device generates ions and radicals to irradiate the resin held in the holding part with the ions and radicals and the state of the potential around the holding part and the resin held in the holding part can be freely adjusted, and the timing and state at which the ions and radicals act on the resin while the resin is contained in the chamber can be freely adjusted. This allows the radicals to be imparted to the surface of the resin in a suitable state, providing high adhesion between the resin member and the metal layer on the member surface, and firmly bonding them.

[0017] According to the inventions described in claims 1 and 7, the application time adjustment unit of the plasma side circuit is set so that the time during which the plasma side circuit applies the plasma side voltage is shorter than the time during which the holding side circuit applies the holding side voltage to the holding unit. Therefore, even before the plasma irradiation process by the plasma irradiation device, a potential difference is generated between the periphery of the resin held in the holding unit and the part other than the periphery of the resin in the chamber, and the distribution state of ions and radicals in the chamber can be easily controlled so that the environment is favorable for plasma generation by the plasma irradiation device. Even after the plasma irradiation process, radicals due to discharge generated by applying the holding side voltage exist in the holding unit, and the addition of hydroxyl groups can be steadily performed. As a result, various radicals can be added to the surface of the resin in a suitable state, and a high adhesion force is given between the resin member and the metal layer on the surface of the member, and they can be firmly bonded.

[0018] According to the invention described in claim 2, in the process of imparting hydroxyl groups to a resin in a state in which at least a portion of the atoms constituting the resin have been removed by irradiating the resin with plasma from the plasma side circuit, the timing and state in which ions or radicals act on the resin can be freely adjusted. This allows radicals to be imparted to the surface of the resin in an appropriate state, providing high adhesion between the resin member and the metal layer on the surface of the member, and enabling them to be firmly bonded together.

[0019] According to the invention described in claim 3, the application time and application timing of the voltage can be appropriately adjusted by a switch for controlling the application of the plasma side voltage on and off, making it possible to appropriately treat the resin surface with simple operations.

[0020] According to the invention described in claim 4, the holding side voltage is applied independently of the plasma side voltage in the process of introducing water vapor gas into the chamber, turning the gas into plasma, and irradiating it onto the surface of the resin. Therefore, when the plasma irradiation device irradiates the plasma onto the surface of the resin, the holding side voltage is used to adjust the potential state of the resin, and the approach and separation state of ions and radicals to and from the surface of the resin can be controlled, thereby appropriately controlling the action of ions and radicals on the surface of the resin for each process.

[0021] According to the invention described in claim 5, the plasma generated by applying a positive voltage as a plasma side voltage to the plasma irradiation device can irradiate the surface of the resin with positive ions, and the surface of the resin can be detached by collision of the ions. In addition, by applying a positive voltage as a holding side voltage to the resin, the potential difference between the plasma irradiation device and the resin can be reduced and the potential difference between the plasma irradiation device and the part other than the resin can be relatively increased, so that the positive ions are attracted to the part other than the resin, and the collision of the ions with the surface of the resin can be prevented from continuing. This makes it possible to appropriately control the processing and surface modification of the resin surface by plasma.

[0022] According to the invention described in claim 6, by applying a holding side voltage to at least a part of the holding section depending on the position where the resin is present, the potential difference between the plasma irradiation device and the resin at the position where the resin is present can be reduced, making it possible to impart radicals to the surface of the resin under more optimal conditions. [Brief description of the drawings]

[0023] [Figure 1] 1A and 1B are diagrams showing a schematic view of a substrate manufacturing system in which a plasma processing apparatus according to this embodiment is used, in which (a) is a schematic view seen from a side, and (b) is a schematic view seen from above. [Diagram 2] FIG. 2 is a diagram showing a schematic diagram of the plasma processing apparatus. [Diagram 3] 4 is a flowchart of processing steps in the above substrate manufacturing system. [Figure 4]4 is a diagram showing a schematic diagram of a state during plasma generation in a second process in the plasma processing apparatus of FIG. [Diagram 5] 4 is a diagram showing a schematic state after plasma generation in a second process in the plasma processing apparatus shown in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] This embodiment is shown in FIG.

[0025] [Configuration of circuit board manufacturing system] FIG. 1 is a diagram showing a substrate manufacturing system in which a plasma processing apparatus according to this embodiment is used, where (a) is a schematic diagram seen from the side, and (b) is a schematic diagram seen from above.

[0026] This board manufacturing system 100 is a manufacturing system consisting of a plurality of devices for performing a plurality of manufacturing processes for manufacturing a circuit board with low transmission loss that is compatible with, for example, millimeter waves or microwaves. Board 21 manufactured in board manufacturing system 100 has a metal layer such as metal film 23 formed on the front and back surfaces of resin board body 22, which is a member to be processed.

[0027] As shown in FIG. 1, in the substrate manufacturing system 100, the member to be processed is a substrate body 22 made of a sheet-shaped resin. A metal layer such as a metal film 23 is formed on the surface of this substrate body 22 in the manufacturing process in the substrate manufacturing system 100 to form a substrate 21. The substrate manufacturing system 100 includes vacuum spare chambers 101 and 102, a first processing chamber 103 for performing a first step S1 and a second step S2 (both of which will be described later), a second processing chamber 104 for performing a third step S3 (described later), and gate valves 24, 24, 25, 26, 27, and 28. The first processing chamber 103 includes a pair of vacuum chambers 2 and 2. The vacuum chamber 2 on one side (left side of FIG. 1) constitutes a processing chamber for performing processing on the front side of the substrate body 22, and the vacuum chamber 2 on the other side (right side of FIG. 1) constitutes a processing chamber for performing processing on the back side of the substrate body 22. In this embodiment, the processing performed on the front side and back side of the substrate body 22 and the process for performing the processing are the same. Therefore, the vacuum chamber 2 on one side and the vacuum chamber 2 on the other side have the same configuration and are provided symmetrically in the up-down direction.

[0028] In the second processing chamber 104, the front surface processing chamber 105 on one side (left side in FIG. 1) and the back surface processing chamber 106 on the other side (right side in FIG. 1) are for performing the same processing on the front surface side and the back surface side of the substrate body 22, and are provided with the same configuration symmetrically on the top and bottom. Fig. 1 shows a state in which heaters 29 for the CVD method are provided symmetrically on the top and bottom in each of the front surface processing chamber 105 and the back surface processing chamber 106. In place of the heater 29, a sputtering device (not shown) used for the PVD method (sputtering method) or the like may be provided.

[0029] As shown in Fig. 1, the vacuum reserve chamber 101 is provided with a movable part 31 that holds the substrate body 22 at its end, and a track part 32a that carries the movable part 31. Similarly, the first processing chamber 103, the second processing chamber 104, and the vacuum reserve chamber 102 are provided with track parts 32b, 32c, 32d, 32e, and 32f that carry the movable part 31 that holds the substrate body 22. The method of carrying the substrate body 22 by the movable part 31 and the track parts 32a, 32b, 32c, 32d, 32e, and 32f shown in Fig. 1 is, for example, a linear guide method or a rack-and-pinion method. In the fourth step S4 (described later), the substrate body 22 is removed from the substrate manufacturing system 100, and the surface of the substrate body 22 is plated with metal offline (not shown) or a metal foil having a thickness equivalent to the plating is laminated to form a metal layer such as a metal film 23 required for the circuit substrate.

[0030] [Configuration of plasma processing device] Fig. 2 is a schematic diagram of the plasma processing apparatus according to this embodiment, showing a first step S1, which will be described later.

[0031] The plasma processing apparatus 1 shown in Fig. 2 constitutes the first processing chamber 103 shown in Fig. 1. This plasma processing apparatus 1 irradiates the surface of the resin with plasma to remove at least a portion of the atoms constituting the resin, and then imparts hydroxyl groups to the resin, thereby improving the wettability of the surface of the resin. The improved wettability makes it possible to strengthen the bonding state when bonding a metal layer such as the metal film 23 to the surface of the resin.

[0032] For simplicity of explanation, only the configuration of the vacuum chamber 2 on one side (the left side in FIG. 1) of the first processing chamber 103 shown in FIG. 1 will be described in the following description, except when a particular distinction is required, and the description of the vacuum chamber 2 on the other side (the right side in FIG. 1) for processing the back side of the substrate body 22 will be omitted.

[0033] The plasma processing apparatus 1 of this embodiment shown in FIG. 2 includes a vacuum chamber 2, a fine plasma gun (hereinafter referred to as "FPG") 3, a holding stand 4 as a "holding unit", a cover 5, a holding side power supply 8, a plasma side power supply 9, a holding side switch 11, and a plasma side switch 12.

[0034] The holding-side power supply 8, the holding table 4, and the vacuum chamber 2 form a holding-side circuit 13. In addition, the plasma-side power supply 9, the plasma-side switch 12, the FPG 3, and the vacuum chamber 2 form a plasma-side circuit 14. In addition, the plasma processing apparatus 1 is equipped with a gas introduction section 15 and an exhaust section 17 having an exhaust pump 16.

[0035] 2 shows a schematic diagram of the scattering directions of the ions 7 and the radicals 6 inside the vacuum chamber 2. The same applies to FIG. 4 described later. As described later, the radicals 6 in this embodiment are hydroxyl radicals. However, the radicals 6 may be any radicals other than hydroxyl radicals.

[0036] The vacuum chamber 2 is made of a highly rigid metal such as an aluminum alloy or stainless steel. The vacuum chamber 2 has a strength sufficient to withstand a pressure difference between the inside and outside caused by evacuation by an exhaust pump 16, and has a box-shaped processing space formed therein. The processing space of the vacuum chamber 2 is designed to be in a vacuum state when the gas inside is forcibly exhausted to the outside by the exhaust pump 16. The vacuum chamber 2 is also connected to a ground 10. This ground 10 sets a reference potential for the holding side circuit 13 and the plasma side circuit 14.

[0037] The FPG 3 is disposed at an upper portion within the vacuum chamber 2. The FPG 3 converts the process gas introduced into the vacuum chamber 2 from the gas introduction part 15 into plasma. As the FPG 3, for example, one described in International Publication No. 2014 / 175702 can be adopted.

[0038] As shown in FIG. 1, the FPG 3 includes a first FPG 3a and a second FPG 3b.

[0039] The first FPG 3a is configured to be able to rotate about a rotation axis (not shown) to change the plasma irradiation direction along the transport direction (left-right direction in FIG. 1) of the substrate body 22. The first FPG 3a is used in a first step S1 described later.

[0040] The second FPG 3b does not have a rotation axis and irradiates plasma in only one direction. The second FPG 3b is used in a second step S2 described later.

[0041] In addition, the second FPG 3b may be configured to have a rotation axis (not shown) and change the plasma irradiation direction to the transport direction of the substrate body 22, or the first FPG 3a may be configured not to have a rotation axis (not shown) and to irradiate plasma in only one direction.

[0042] The holder 4 is placed below the FPG 3 so as to face the FPG 3. The holder 4 is made of metal or an electrode, and holds the substrate main body 22.

[0043] The holding table 4 in this embodiment receives a holding-side voltage (described later) from a holding-side power supply 8 in a second step S2 described later.

[0044] In a first step S1 and a second step S2, the holding table 4 receives a holding-side voltage (described later) from the holding-side power supply 8 at least in a portion depending on the position where the substrate body 22 is present. For example, in the second step S2, the holding table 4 may be configured so that the holding-side voltage is applied to the side of the holding table 4 near the second FPG 3b (the right side in FIG. 1). In order to apply the holding-side voltage in this manner, the holding table 4 may be configured to apply the holding-side voltage only to a portion of the holding table 4, for example, to form a first conductive range (not shown) near the first FPG 3a and a second conductive range (not shown) near the second FPG 3b on the holding table 4, and to be provided with a changeover switch (not shown) for selectively switching the current from the holding-side power supply 8 between the first conductive range (not shown) and the second conductive range (not shown). However, the position or range of the holding table 4 to which the holding-side voltage is applied may be changed or switched by any other configuration.

[0045] In addition, the position and range at which the holding side voltage is applied to the holding table 4 in the first step S1 and the second step S2 may be any one, and the holding side voltage may be applied to the entire area of ​​the holding table 4 in both the first step S1 and the second step S2.

[0046] The cover 5 covers the upper surface of the holder 4. The cover 5 is made of the same material as the substrate body 22. It is configured so that plasma from the FPG 3 is uniformly irradiated onto the substrate body 22. Without the cover 5, the plasma from the FPG 3 would also be irradiated onto the metallic holder 4, processing the metal portion, and the particles removed would adhere to and contaminate the substrate body 22. The cover 5 is necessary to prevent this contamination. Note that when the effect of the particles is small, omitting the cover 5 does not affect the present invention.

[0047] The holding-side power supply 8 is a DC power supply. The holding-side power supply 8 has a positive electrode connected to the holding table 4 and a negative electrode connected to the vacuum chamber 2, and applies a holding-side voltage, which is a DC voltage, to the holding-side circuit 13.

[0048] The plasma-side power supply 9 is a DC power supply. The plasma-side power supply 9 has a positive electrode connected to the holding table 4 side and a negative electrode connected to the vacuum chamber 2 side, and applies a plasma-side voltage, which is a DC voltage, to the plasma-side circuit 14. In order to emit plasma from the FPG 3, it is desirable that the plasma-side power supply 9 has a larger output than the holding-side power supply 8 and can apply a higher voltage than the holding-side power supply 8 to the plasma-side circuit 14.

[0049] The holding-side switch 11 and the plasma-side switch 12 are switches that switch the energized state of the circuits between ON and OFF. The holding-side switch 11 switches the current flowing through the holding-side circuit 13 between ON and OFF, and the plasma-side switch 12 switches the current flowing through the plasma-side circuit 14 between ON and OFF.

[0050] The holding side switch 11 is selectively connected to the conducting side conductor 18 and the non-conducting side conductor 19. The conducting side conductor 18 is electrically connected to the holding side power supply 8, and the holding side circuit 13 is turned ON when the holding side switch 11 is connected, and the voltage of the holding side power supply 8 is applied to the holding base 4. The non-conducting side conductor 19 is electrically connected to the holding base 4 without passing through the holding side power supply 8, and the holding side circuit 13 is turned OFF when the holding side switch 11 is connected, and the potential of the holding base 4 becomes equal to the potential of the ground 10.

[0051] The holding side switch 11 and the plasma side switch 12 may be capable of adjusting the flow rate of the current flowing through the circuit from 0 to the maximum in a stepwise or stepless manner. The holding side switch 11 and the plasma side switch 12 may be capable of being switched ON / OFF by a control device such as a microcomputer (not shown), or may be capable of being switched ON / OFF manually by an operator.

[0052] The gas inlet 15 is a metal pipe that introduces into the vacuum chamber 2 gases used in a first step S1 and a second step S2, which will be described later.

[0053] The exhaust unit 17 is a metal pipe provided with an exhaust pump 16. When the exhaust pump 16 is operated, the exhaust unit 17 exhausts various gases, particles, dust, and the like present in the vacuum chamber 2 to the outside.

[0054] [Board body] In this embodiment, the resin constituting the substrate body 22 is not particularly limited as long as it has a hydrophobic surface, and examples thereof include fluororesins such as PTFE, PFA, and PCTFE, polyimide, and LCP. Specifically, in the case of fluororesins, the resin as the material of the substrate body 22 contains fluorine and carbon, and the atoms that are detached from the hydrophobic surface of the resin are mainly fluorine and carbon. By providing hydroxyl groups to the activated surface after the molecular bonds are broken, the hydrophobic surface of the fluororesin can be significantly hydrophilized. In addition, this phenomenon occurs only on the resin surface, and the base material of the resin containing fluorine underneath has high insulation, low relative dielectric constant and dielectric loss tangent, and low signal transmission loss, making it excellent as an electric substrate.

[0055] Furthermore, the resin used as the material of the substrate body 22 may contain wholly aromatic polyester in addition to the above-mentioned materials, and the atom released from the hydrophobic surface of the resin may be oxygen.

[0056] [plasma] In this embodiment, the plasma generated from the FPG 3 preferably contains at least one of nitrogen and argon. It may be a mixed gas of nitrogen and argon. This is because atoms constituting the resin used as the material of the substrate body 22 are easily desorbed from the surface of the resin by ions of nitrogen or argon.

[0057] [Processing process] 3 is a flowchart of processing steps in substrate manufacturing system 100 according to this embodiment. Below, the substrate manufacturing steps according to this embodiment will be described using this flowchart.

[0058] [First step] In the substrate manufacturing system 100, first, in the first step (step S1, hereinafter referred to as "first step S1"), ions are irradiated onto the surface of the substrate body 22, which is the member to be processed, to break the molecular bonds on the substrate surface and cause at least a portion of the resin atoms that make up the substrate to be detached.

[0059] 1 is opened, and the movable part 31 holding the end of the substrate body 22 is attached to the track part 32a in the vacuum reserve chamber 101. The gate valve 24 is closed, and the pressure in the vacuum reserve chamber 101 is reduced. When the pressure in the vacuum reserve chamber 101 becomes 10 Pa or less, the gate valve 25 is opened.

[0060] After opening the gate valve 25, the movable part 31 is moved into the vacuum chamber 2 of the first processing chamber 103, and the gate valve 25 is closed. At this time, the holding-side switch 11 and the plasma-side switch 12 are both OFF, and neither the holding-side circuit 13 nor the plasma-side circuit 14 is energized. As described above, when the holding-side switch 11 is OFF, the holding-side switch 11 is connected to the non-energized-side conductor 19, and the potential of the holding table 4 is equal to the potential of the ground 10.

[0061] In the first step S1, plasma from the first FPG 3a is irradiated onto the hydrophobic surface (the upper surface side in FIG. 1a) of the substrate body 22 to remove at least a portion of the atoms of the resin constituting the substrate body 22 from the surface of the substrate body 22. That is, in the first step S1, the hydrophobic surface of the substrate body 22 is activated by using plasma, particularly ions in the plasma, to activate the surface of the resin constituting the substrate body 22.

[0062] Specifically, while reducing the pressure inside the vacuum chamber 2 with the exhaust pump 16, nitrogen and argon process gases are introduced into the vacuum chamber 2 from the gas inlet 15, and the pressure inside the vacuum chamber 2 is adjusted to a predetermined pressure, for example, 0.3 Pa between 0.1 Pa and 0.4 Pa.

[0063] 2, when the plasma side switch 12 is turned on and the plasma side circuit 14 is energized, the second DC voltage is applied from the plasma side power supply 9 to the first FPG 3a, and plasma of the processing gas is generated in the first FPG 3a. The second FPG 3b is used in the second step S2 described later, and is not energized in this step, so no plasma is generated.

[0064] At this time, if the pressure inside the vacuum chamber 2 is too high (for example, if it exceeds 0.4 Pa), the processing gas enters a glow discharge state, and the traveling direction of the ions 7 and radicals 6 in the plasma cannot be controlled. In contrast, if the pressure inside the vacuum chamber 2 is within an appropriate range, the processing gas can be maintained in a dark discharge state, and the traveling direction of the ions 7 and radicals 6 can be controlled. Therefore, the pressure inside the vacuum chamber 2 is adjusted to, for example, 0.1 Pa or more and 0.4 Pa or less. It is preferable that the pressure inside the vacuum chamber 2 be approximately 0.3 Pa.

[0065] The first FPG 3a generates plasma of the processing gas filled in the vacuum chamber 2, and as shown in Fig. 2, the plasma becomes directional ions and radicals, which are irradiated onto the substrate body 22. At this time, the generated ions have positive polarity, and the radicals are non-polar.

[0066] Then, as shown in FIG. 2, the generated ions 7 and radicals 6 collide with the substrate body 22, and the atoms of the resin constituting the substrate body 22 are detached from the surface of the substrate body 22 mainly due to the impact of the collision of the ions 7. Most of the detached atoms are exhausted from the exhaust unit 17 to the outside of the vacuum chamber 2 by the exhaust of the exhaust pump 16. Some of the detached atoms float in the vacuum chamber 2, or after floating, adhere to the inner wall of the vacuum chamber 2 or to components in the vacuum chamber 2. However, in this embodiment, since the pressure in the vacuum chamber 2 is lower than the general glow discharge conditions, there are almost no impurities (particles, etc.) floating in the chamber 2. Therefore, it is possible to prevent the surface of the substrate body 22 from being contaminated by impurities adhering thereto.

[0067] [End of first process] When the first step S1 is to be ended, the plasma-side switch 12 is turned off to release the power supply to the plasma-side circuit 14. This ends the generation of plasma of the processing gas by the first FPG 3a.

[0068] [Power supply state after the first process is completed] During the period from the end of the first step S1 to the start of the second step S2 described later, the holding-side switch 11 is connected to the current-carrying conductor 18 and turned ON to energize the holding-side circuit 13. This causes a holding-side voltage from the holding-side power supply 8 to be applied to the holding table 4 and the substrate body 22 on the holding table 4. The holding-side voltage is applied to a first conductive range (not shown) near the first FPG 3a. At this time, it is desirable for the holding-side power supply 8 to apply a voltage to the holding-side circuit 13 that is at least 40% of the voltage of the plasma-side power supply 9, but is smaller than the voltage of the plasma-side power supply 9.

[0069] A positive voltage is applied as a holding-side voltage to the holding table 4 and the substrate body 22 on the holding table 4, which constitute the holding-side circuit 13. On the other hand, the wall surface of the vacuum chamber 2, which constitutes the holding-side circuit 13, is at a lower potential than the holding table 4 and the substrate body 22. The first FPG 3a is on the positive side, and the opposing holding table 4 is also on the positive side, and since the voltages of both are close, it becomes difficult for the first FPG 3a to generate plasma. By applying a holding-side voltage from the holding-side power supply 8 during the period from the end of the first step S1 to the start of the second step S2, which will be described later, it becomes possible to create an environment in which the first FPG 3a is likely to generate plasma.

[0070] [Second process] When a second step (step S2, hereinafter referred to as "second step S2") is performed in the vacuum chamber 2 after the first step S1, the following procedure is followed.

[0071] In this embodiment, the first step S1 and the second step S2 are performed in the same vacuum chamber 2 to simplify the processing steps and reduce the size of the apparatus. However, the vacuum chamber 2 in which the first step S1 is performed and the vacuum chamber (not shown) in which the second step S2 is performed may be provided separately. By providing the vacuum chamber 2 in which the first step S1 is performed and the vacuum chamber (not shown) in which the second step S2 is performed separately, it is possible to easily prevent a situation in which the desorbed components adhere to the surface of the substrate body 22 in the second step S2 even if the desorbed components desorbed from the surface of the substrate body 22 in the first step S1 are floating in the vacuum chamber 2.

[0072] In this embodiment, after the first step S1, the exhaust pump 16 is used to properly remove the desorbed components from within the vacuum chamber 2, thereby preventing floating matter originating from the first step S1 from affecting the second step S2.

[0073] After the first step S1 is completed, the substrate body 22 is maintained in a state where it is held on the holding table 4 in the vacuum chamber 2.

[0074] Next, the exhaust pump 16 continues to operate to maintain the reduced pressure state in the vacuum chamber 2. If the supply of nitrogen and / or argon used in the first step S1, which is present in the vacuum chamber 2, is stopped, the exhaust pump 16 immediately discharges it to the outside of the vacuum chamber 2. Then, while introducing water vapor, which is a processing gas, into the vacuum chamber 2 from the gas inlet 15, the exhaust pump 16 is controlled to adjust the pressure in the vacuum chamber 2 in the second step S2 so that the pressure in the vacuum chamber 2 is 30% to 50% of the pressure in the first step S1. This is because the radicals 6 (hydroxyl radicals) can be optimally attached to the surface in the plasma of the processing gas by performing the processing in the second step S2 described later at a pressure of 30% to 50% of the pressure in the first step S1.

[0075] After the processing gas is introduced into the vacuum chamber 2, as shown in FIG. 4, the holding side switch 11 is switched from a state connected to the non-energized side conductor 19 to a state connected to the energized side conductor 18 to turn on the holding side circuit 13, and the voltage of the holding side power supply 8 is applied to the holding table 4. The holding side voltage is applied to a second conductive range (not shown) near the second FPG 3b. Note that the processing gas may be introduced into the vacuum chamber 2 after or simultaneously with turning on the holding side circuit 13. Next, the plasma side circuit 14 is turned on to energize the FPG 3 from the plasma side power supply 9. As shown in FIG. 1, the second FPG 3b is activated by applying the plasma side voltage to the second FPG 3b, and plasma of the processing gas filled in the vacuum chamber 2 is generated.

[0076] At this time, the first DC voltage applied to the holding table 4 from the holding-side power supply 8 is preferably smaller than the second DC voltage applied to the second FPG 3b from the plasma-side power supply 9. Specifically, it is more preferable that the first DC voltage from the holding-side power supply 8 is 40% or more of the second DC voltage applied to the second FPG 3b from the plasma-side power supply 9 and smaller than the second DC voltage.

[0077] The holding-side power supply 8 applies a positive voltage to the holding table 4 and the substrate body 22, and the plasma-side power supply 9 applies a positive voltage to the second FPG 3b. The potentials of the second FPG 3b and the holding table 4 are each formed in the positive direction, while the potential of the vacuum chamber 2 (forming the plasma-side circuit 14 and the holding table 4) relative to the second FPG 3b and the holding table 4 is formed in the negative direction. Also, while the potential difference between the second FPG 3b and the holding table 4 is decreasing, the potential differences between the FPG 3 and the vacuum chamber 2 and between the holding table 4 and the vacuum chamber 2 are increasing.

[0078] In this state, when plasma is generated in the process gas in the vacuum chamber 2 by the second FPG 3b, most of the positive ions 7 in the plasma move in the direction of the vacuum chamber 2 where the potential difference is large, as shown in Fig. 5. On the other hand, radicals 6 (hydroxyl radicals) with no polarity in the plasma are irradiated to the substrate body 22.

[0079] By irradiating the substrate body 22 with radicals 6 (hydroxyl radicals), hydroxyl groups are introduced into the surface of the substrate body 22. Moreover, since the ions 7 move toward the wall surface of the vacuum chamber 2 and the substrate body 22 is hardly irradiated with the ions 7, the hydroxyl groups introduced into the surface of the substrate body 22 by the impact of the ions are prevented from being detached again. In this way, stable hydrophilicity is imparted to the surface of the substrate body 22. The introduction of the hydroxyl groups results in stable chemical bonding of the hydroxyl groups to the surface of the substrate body 22. The amount of bonding increases with the irradiation time until the reactive groups are gone. As the number of hydroxyl groups increases, the contact angle decreases.

[0080] The surface of the substrate body 22 on which hydroxyl groups have been introduced by the second step S2 has a contact angle with water of 10° or less, more preferably 6° or less, and an appropriate irradiation time is set. In this way, the surface of the substrate body 22 and the metal film 23 are firmly attached to each other in the third step S3 and the fourth step S4 described later.

[0081] [Pressure and temperature in the first and second steps] It is preferable that both the first step and the second step are performed in a state where the inside of the vacuum chamber 2 is depressurized. It is also preferable that after the first step, the second step is performed while maintaining the depressurized state. This is because hydroxyl groups can be introduced into the surface of the resin constituting the substrate body 22 while maintaining the activated state of the surface of the resin constituting the substrate body 30 in the first step. It is also preferable that the surface of the resin constituting the substrate body 22 is depressurized. The hydrophilicity of the surface of the resin that has been subjected to the second step is maintained for a long period of time, for example, for one month or more. Therefore, the substrate body 22 may be released to atmospheric pressure immediately after the second step.

[0082] It is preferable that the first step S1 is performed at a first pressure of 0.1 Pa or more and 0.4 Pa or less, and the second step S2 is performed at a second pressure of 30% to 50% of the first pressure. This is because in the first step S1, it is easy to control the way in which ions and radicals in the plasma move, and in the second step, the surface of the substrate body 22 is hardly irradiated with ions, and hydroxyl radicals are easily irradiated with the surface of the substrate body 22.

[0083] In addition, the second step S2 is preferably performed by setting the temperature of the substrate body 22 to 150° C. or more and 300° C. or less. This is because the chemical reaction between the hydroxyl groups and the surface of the resin constituting the substrate body 22 is promoted, and the hydroxyl groups are firmly introduced into the surface constituting the substrate body 22.

[0084] [Power supply state after the second process] In the second step S2, even after the plasma-side power supply 9 is turned OFF to stop the application of the second DC voltage to the second FPG 3b, it is desirable to keep the holding-side switch 11 connected to the current-carrying conductor 18 and the holding-side circuit 13 ON, as shown in FIG. 5. When the holding-side circuit 13 is turned ON, a positive voltage is applied from the holding-side power supply 8 to the holding table 4 and the substrate body 22, and the holding-side circuit 13 has a positive potential on the holding table 4 side and a negative potential on the vacuum chamber 2 side, so that the positive ions in the vacuum chamber 2 are attracted to the wall side of the vacuum chamber 2, which has a large potential difference. This prevents the hydroxyl groups introduced to the surface of the substrate body 22 by the impact of the ions from being detached again, even after the plasma-side power supply 9 is turned OFF. In addition, the application of a positive voltage from the holding-side power supply 8 to the holding table 4 and the substrate body 22 allows the remaining hydroxyl groups to be attached by a slight glow discharge generated in the holding table 4.

[0085] In the second step S2, the length of time for which the holding-side circuit 13 is kept ON after the plasma-side power supply 9 is turned OFF may be any length. Specifically, it is sufficient that the time for which the holding-side power supply 8 applies the holding-side voltage to the holding table 4 and the substrate body 22 is longer than the time for which the plasma-side power supply 9 applies the plasma-side voltage to the right-side FPG 3, and that the detachment of the surface of the substrate body 22 caused by ions can be prevented from progressing. In this description, for ease of understanding, the first FPG 3a is used for the first step S1, and the right FPG 3 is used for the second step S2. However, the second FPG 3b may be used for the first step S1. In this case, it is preferable that the plasmas generated from the first FPG 3a and the second FPG 3b are parallel to each other so as not to interfere with each other. In addition, in the holder 4 facing the second FPG 3b for the second step S2, it is better to apply a positive voltage to the area facing the second FPG 3b, rather than to the entire surface of the holder 4 (i.e., it is preferable to form the above-mentioned second conductive area (not shown) in a range approximately equal to the area facing the second FPG 3b). By configuring in this way, it is possible to prevent a change in the process environment due to discharge by the holder 4 in the part not facing the second FPG 3b. When the second FPGA 3b is swiveled depending on the position of the substrate body 22, the position of the corresponding holder 4 changes, so it is desirable to change the range applied to the holder 4 (the above-mentioned second conductive range (not shown)) depending on the irradiation position of the second FPGA 3b. Similarly, when the first FPGA 3a is swiveled, it is desirable to change the range applied to the holder 4 (the above-mentioned first conductive range (not shown)) depending on the irradiation position of the first FPGA 3a.

[0086] [Third step, fourth step] After the second step S2, the gate valve 26 is opened, and the substrate body 22 is accommodated in the second treatment chamber 104 where the third step is performed. After the substrate body 22 is accommodated in the second treatment chamber 104, the holding side switch 11 is connected to the non-current-carrying side conductor 19, and the holding side circuit 13 is turned OFF.

[0087] In the second processing chamber 104, the substrate body 22 is subjected to a processing in a third step (step S3, hereinafter referred to as "the third step S3").

[0088] In the third step S3, a metal film 23 is deposited on the surface of the substrate body 22 that has been subjected to the first step S1 and the second step S2. The deposition of the metal film 23 is performed by, for example, a CVD method (chemical vapor deposition method) or a PVD method (sputtering method). Examples of the metal film 23 include a copper film, a silver film, and a gold film. Fig. 1 shows a state in which a heater 29 for the CVD method is provided in the second processing chamber 104. After the third step S3 is completed, the gate valve 27 is opened, the movable part 31 is moved into the vacuum reserve chamber 102, and the gate valve 27 is closed. After the pressure inside the vacuum reserve chamber 102 is returned to atmospheric pressure, the gate valve 38 is opened and the completed substrate 21 is removed.

[0089] In a fourth step (step S4, hereinafter referred to as "fourth step S4"), the substrate is removed from the substrate manufacturing system 100, and metal plating and thermocompression bonding are performed offline on the surface of the substrate body 22. The metal used for plating and thermocompression bonding in the fourth step S4 is the same as the metal used in the third step S3, and examples of the metal used include copper, silver, and gold.

[0090] Furthermore, the fourth step S4 may be performed independently without performing the third step S3, but is preferably performed after the third step S3, in which the metal film 23 is formed on the surface of the substrate body 22. When the metal film is vapor-deposited in the third step S3, in the fourth step S4, the metal film 23 or other metal layer is formed on the surface of the substrate body 22 by further bonding using plating or thermocompression bonding of the same metal.

[0091] In addition, in the second processing chamber 104, after the third step S3, the fourth step S4 may be performed in a vacuum without removing the substrate from the substrate manufacturing system 100. In this case, a metal foil is formed on the metal film 23 formed on the substrate body 22 in the third step S3. Since the entire process is performed in a vacuum, the Cu film can be adhered to the metal foil without being affected by oxidation of the Cu film by the atmosphere. This allows a high degree of adhesion to be obtained.

[0092] [Modification of the substrate body and hydroxyl groups] In this embodiment, the resin constituting the substrate body 22 may be polytetrafluoroethylene, and the atom substituted with the hydroxyl group in the second step S2 may be fluorine. Also, the resin constituting the substrate body 22 may be a liquid crystal polymer including a wholly aromatic polyester.

[0093] [Effects] As described above, in this embodiment, the time for applying the holding-side voltage to the resin held by the holding table 4 by the holding-side circuit 13, which applies the holding-side voltage as a DC voltage to the substrate body 22, which is the resin to be irradiated with plasma, and the time for applying the plasma-side voltage to the FPG3 by the plasma-side circuit 14, which is configured to apply the plasma-side voltage as a DC voltage to the FPG3, which turns the gas introduced by the gas introduction section 15 into plasma, are set to be separate, so that the timing at which the FPG3 generates ions and radicals to irradiate the resin held by the holding table 4 with the ions and radicals, and the state of the potential around the holding table 4 and the substrate body 22 held by the holding table 4 can be freely adjusted, and the timing and state at which the ions and radicals act on the substrate body 22 while the substrate body 22 is accommodated in the vacuum chamber 2 can be freely adjusted. This allows radicals to be applied to the surface of the substrate body 22 in a suitable state, providing high adhesion between the substrate body 22 and a metal layer such as the metal film 23 on the surface of the substrate body 22, and allowing them to be firmly bonded to each other.

[0094] In this embodiment, in the process of providing hydroxyl groups to the substrate body 22 in a state in which at least some of the atoms constituting the substrate body 22 have been removed by irradiating the substrate body 22 with plasma from the plasma side circuit 14, it is possible to freely adjust the timing and state in which ions and radicals act on the substrate body 22. This allows the radicals to be provided to the surface of the substrate body 22 in a suitable state, providing high adhesion between the resin substrate body 22 and a metal layer such as the metal film 23 on the surface of the substrate body 22, and allowing them to be firmly bonded together.

[0095] In this embodiment, the time during which the plasma-side circuit 14 applies the plasma-side voltage is set shorter than the time during which the holding-side circuit 13 applies the holding-side voltage to the holding table 4 by ON / OFF control of the plasma-side switch 12 as the application time adjustment unit of the plasma-side circuit 14, so that even before and after the plasma irradiation process by the FPG 3, a potential difference is generated between the periphery of the substrate body 22 held by the holding table 4 and the portion other than the periphery of the substrate body 22 in the vacuum chamber 2, and the distribution state of ions and radicals in the vacuum chamber 2 can be easily controlled for a long time. This makes it possible to impart various kinds of radicals to the surface of the substrate body 22 in an appropriate state, providing high adhesion between the substrate body 22 and a metal layer such as the metal film 23 on the surface of the substrate body 22, and bonding them firmly.

[0096] In this embodiment, the application time and timing of the voltage can be appropriately adjusted using the plasma side switch 12 for controlling the application of the plasma side voltage on and off, making it possible to appropriately process the surface of the substrate body 22 with simple operations.

[0097] In this embodiment, the holding side voltage is applied during the process of introducing gas into the vacuum chamber 2, turning the gas into plasma, and irradiating the surface of the substrate body 22. When the FPG3 irradiates the plasma onto the surface of the substrate body 22, the holding side voltage is used to adjust the potential state of the substrate body 22, thereby controlling the approach and separation state of ions and radicals to and from the surface of the substrate body 22, thereby appropriately controlling the action of ions and radicals on the surface of the substrate body 22 for each process.

[0098] In this embodiment, a positive voltage is applied to the FPG3 as a plasma-side voltage to generate plasma, which irradiates the surface of the resin with positive ions, and the surface of the resin can be detached by collision of the ions. Also, by applying a positive voltage to the resin as a holding-side voltage, the potential difference between the FPG3 and the resin is reduced, and the potential difference between the FPG3 and the portion other than the substrate body 22 is relatively increased, so that the positive ions are attracted to the portion other than the substrate body 22, and the collision of the ions with the surface of the substrate body 22 can be prevented from continuing. This makes it possible to appropriately control the processing and surface modification of the surface of the substrate body 22 by plasma.

[0099] In this embodiment, by applying a holding side voltage to at least a part of the holding table 4 depending on the position where the substrate body 22 is located, the potential difference between the FPG 3 and the substrate body 22 at the position where the substrate body 22 is located is reduced, making it possible to impart radicals to the surface of the substrate body 22 under more optimal conditions.

[0100] It goes without saying that the above-mentioned embodiment is merely an example of the present invention, and does not mean that the present invention is limited to only the above-mentioned embodiment. In other words, various modifications and applications of the present embodiment are possible as long as they are suitable for solving the problems of the present invention. [Industrial Applicability]

[0101] The plasma processing apparatus and the plasma processing method of the present embodiment are used, for example, in the manufacture of circuit boards for use in mobile phones that communicate large volumes of information at high speed. Since the relative dielectric constant of fluororesin is the second lowest after air, fluororesin boards are particularly suitable as materials for high-frequency boards. Compared to circuit boards made of other common materials, circuit boards made of fluororesin have a low relative dielectric constant and dielectric loss tangent, and have low dielectric loss, even when high-frequency current is passed through them.

[0102] When the plasma processing apparatus and the plasma processing method of the present embodiment are applied to the manufacture of a fluororesin substrate, the hydrophilicity of the manufactured substrate is improved, and the adhesion with the copper wiring is improved, and a circuit substrate that can withstand use in a high frequency band can be provided. This technology applicable to use in a high frequency band can be applied not only to the main body of a mobile phone, but also to substrates used in mobile phone base stations, substrates for communication in the home, in a factory, or for a specific region, or substrates for millimeter wave radars used in automatic driving of automobiles or drones. The plasma processing apparatus and the plasma processing method of the present embodiment can also be used to manufacture substrates in various fields other than those mentioned above. [Explanation of symbols]

[0103] 1. Plasma treatment device 2. Vacuum chamber (chamber) 3. FPG (Plasma irradiation device) 3a First FPG (plasma irradiation device) 3b Second FPG (plasma irradiation device) 4...Holding stand (holding part) 13... Holding side circuit 14 Plasma side circuit 15 Gas inlet 22.... Board body (resin)

Claims

1. A plasma processing apparatus for irradiating a surface of a resin present in a chamber with plasma to improve wettability of the surface of the resin, comprising: a holding circuit having a holding portion for holding the resin to be irradiated with the plasma, the holding circuit applying a holding voltage to the held resin; a gas inlet for introducing a gas into the chamber; A plasma irradiation device is provided for converting the gas into plasma, and a plasma side circuit is provided for applying a plasma side voltage as a DC voltage to the plasma irradiation device, The holding-side circuit is set so that a time for applying the holding-side voltage to the resin and a time for applying the plasma-side voltage to the plasma irradiation device by the plasma-side circuit are separate, The plasma processing apparatus is characterized in that the plasma side circuit is provided with an application time adjustment unit for setting the time during which the plasma side circuit applies the plasma side voltage to be shorter than the time during which the holding side voltage is applied to the holding side circuit.

2. 2. The plasma processing apparatus according to claim 1, wherein the plasma side circuit is set so that a time for applying the holding side voltage and a time for applying the plasma side voltage are separate for a process of imparting hydroxyl groups to the resin in a state in which at least a portion of the atoms constituting the resin have been released by irradiating the resin with plasma through the plasma side circuit.

3. 3. The plasma processing apparatus according to claim 1, wherein the application time adjustment unit of the plasma side circuit is a switch for controlling on / off application of the plasma side voltage to the plasma irradiation device.

4. 4. The plasma processing apparatus according to claim 1, wherein the holding side circuit applies the holding side voltage independently of the plasma side circuit during the process of introducing the gas into the chamber, converting the gas into plasma, and irradiating the gas onto the surface of the resin.

5. 5. The plasma processing apparatus according to claim 1, wherein the plasma side circuit applies a positive voltage of the plasma side voltage to the plasma irradiation device, and the holding side circuit applies a positive voltage of the holding side voltage to the resin.

6. 6. The plasma processing apparatus according to claim 1, wherein the holding circuit applies the holding voltage to at least a part of the holding portion depending on a position where the resin is present.

7. a chamber for accommodating a resin to be irradiated with plasma; a holding circuit having a holding portion for holding the resin to be irradiated with the plasma, the holding circuit applying a holding voltage to the held resin; a gas inlet for introducing a gas into the chamber; A plasma irradiation device is provided for converting the gas into plasma, and a plasma side circuit is provided for applying a plasma side voltage as a DC voltage to the plasma irradiation device, A plasma processing method for improving wettability of a surface of a resin present in the chamber by irradiating the surface of the resin with plasma, the method comprising: The holding-side circuit is set so that a time for applying the holding-side voltage to the resin and a time for applying the plasma-side voltage to the plasma irradiation device by the plasma-side circuit are separate, The plasma processing method is characterized in that the plasma side circuit is provided with an application time adjustment unit for setting the time during which the plasma side circuit applies the plasma side voltage to be shorter than the time during which the holding side voltage is applied to the holding side circuit.

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