Plasma processing apparatus and plasma processing 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 in which a metal layer is formed on the surface of the resin. [Background technology]

[0002] Low-dielectric resins are beginning to be used in various circuit boards, such as those with low transmission loss and 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 with poor adhesion between themselves and with copper, which is used as wiring material. For this reason, techniques are known to improve the physical adhesion between the resin substrate and copper, such as chemically roughening the surface of the circuit board substrate or forming irregularities on the surface of the copper foil that is attached to the substrate.

[0003] However, if 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, if copper is attached to the surface of the substrate using an adhesive, the adhesive layer itself becomes a cause of transmission loss in the circuit board. If copper is formed on the surface of the substrate by plating, sufficient adhesion between the substrate and the copper cannot be obtained. 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 then adhere the copper to the surface of the PTFE substrate to obtain a laminate of PTFE substrate and copper.

[0004] However, even when irradiated with atmospheric plasma, the contact angle of the PTFE substrate with water is at most about 50°. Furthermore, when copper is adhered to the surface of the PTFE substrate, the adhesion between the PTFE substrate and the copper is about 0.2 to 0.4 N / mm. Therefore, there is a risk that the copper may peel off from the PTFE substrate during the process of forming a copper circuit pattern on the PTFE substrate. Furthermore, if heat is applied to the PTFE substrate during the circuit pattern formation process, the adhesion between the PTFE substrate and the 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, once adsorbed hydroxyl groups are released from the surface of the substrate when other water vapor ions are irradiated onto the surface of the substrate. As a result, in the invention described in Patent Document 1, the contact angle between the surface of the substrate and water is approximately 40°. Furthermore, the invention described in Patent Document 1 has the problem that it is difficult to firmly adhere metal to the surface of a resin member.

[0008] The present application has been made in view of the above circumstances, and aims to provide 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 member and a metal layer on the surface of the member, and firmly bond them together. [Means for solving the problem]

[0009] In order to solve this problem, the invention described in claim 1 is ,blood A plasma processing apparatus for irradiating a surface of a resin present in a chamber with plasma to improve the wettability of the surface of the resin, the apparatus comprising: a holding section for holding the resin to be irradiated with the plasma; a holding-side circuit for applying a holding-side voltage to the held resin; a gas inlet section for introducing a gas into the chamber; and a plasma irradiation device for converting the gas into plasma, the plasma-side circuit being configured to apply a plasma-side voltage as a DC voltage to the plasma irradiation device. the plasma treatment device is configured to perform a first step of irradiating the resin with plasma from a plasma side circuit to remove at least a portion of atoms constituting the resin, and a second step of imparting hydroxyl groups to the resin from which at least a portion of the atoms have been removed in the first step; 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, and the plasma-side circuit is During the period from when the first step is performed and at least a part of the atoms constituting the resin is removed to when the second step is performed and a hydroxyl group is added to the resin, The device is characterized by having 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.

[0010] The invention described in claim 2 is ,blood A plasma processing apparatus for irradiating a surface of a resin present in a chamber with plasma to improve the wettability of the surface of the resin, the apparatus comprising: a holding section for holding the resin to be irradiated with the plasma; a holding-side circuit for applying a holding-side voltage to the held resin; a gas inlet section for introducing a gas into the chamber; and a plasma irradiation device for converting the gas into plasma, the plasma-side circuit being configured to apply a plasma-side voltage as a DC voltage to the plasma irradiation device. The plasma processing apparatus is configured to perform at least a first step of irradiating the resin with plasma by a plasma-side circuit to remove at least a portion of atoms constituting the resin, and a second step of imparting hydroxyl groups to the resin from which at least a portion of the atoms have been removed in the first step, wherein the plasma-side circuit and the holding-side circuit comprise a first voltage application unit that turns on the plasma-side circuit to apply the plasma-side voltage to the plasma irradiation device and turns off the holding-side circuit in the first step, a second voltage application unit that turns off the plasma-side circuit and turns on the holding-side circuit to apply the holding-side voltage to the holding unit during the period from the end of the first step to the start of the second step, and a third voltage application unit that turns on the plasma-side circuit to apply the plasma-side voltage to the plasma irradiation device and turns on the holding-side circuit to apply the holding-side voltage to the holding unit in the second step. The present invention is characterized by the following features.

[0011] Claim 3 The invention described in claim 1 or 2 In addition to the configuration described above, the plasma side circuit and the holding side circuit. is the above The first step was carried out The resin Nihi Adding hydroxyl groups The second process Do Therefore, the time for applying the holding-side voltage and the time for applying the plasma-side voltage are set to be different from each other.

[0014] Claim 4 The invention described in is a plasma processing method comprising: a chamber for accommodating a resin to be irradiated with plasma; a holding circuit for applying a holding voltage to the held resin; a gas inlet for introducing gas into the chamber; and a plasma irradiation device for converting the gas into plasma, the plasma side circuit being configured to apply a plasma voltage as a DC voltage to the plasma irradiation device; the method irradiating plasma onto a surface of a resin present in the chamber, thereby improving the wettability of the surface of the resin, The plasma treatment method is configured to carry out a first step of irradiating the resin with plasma from a plasma side circuit to remove at least a portion of atoms constituting the resin, and a second step of imparting hydroxyl groups to the resin from which at least a portion of the atoms have been removed in the first step, 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, and the plasma-side circuit Prepared for , The application time adjusting unit, which is provided to adjust the time for which the plasma-side circuit applies the plasma-side voltage, adjusts the time until the resin in the first step, from which at least a part of the atoms constituting the resin has been released, is given a hydroxyl group in the second step. The time during which the plasma-side circuit applies the plasma-side voltage is set to be shorter than the time during which the holding-side voltage is applied to the holding-side circuit. will be It is characterized by:

[0015] Claim 5The invention described in is a plasma processing method for irradiating a surface of a resin present in a chamber with plasma to improve the wettability of the surface of the resin, and the plasma processing apparatus for performing the plasma processing method has a holding part for holding the resin to be irradiated with the plasma, and is equipped with a holding side circuit for applying a holding side voltage as a DC voltage to the held resin, a gas introduction part for introducing a gas into the chamber, and a plasma irradiation device for converting the gas into plasma, and a plasma side circuit configured to apply a plasma side voltage as a DC voltage to the plasma irradiation device, The plasma processing apparatus is configured to perform at least a first step of irradiating the resin with plasma by a plasma-side circuit to remove at least a portion of atoms constituting the resin, and a second step of imparting hydroxyl groups to the resin from which at least a portion of the atoms have been removed in the first step, wherein the plasma-side circuit and the holding-side circuit are configured to perform a first voltage application step in which the plasma-side circuit is turned on to apply the plasma-side voltage to the plasma irradiation device and the holding-side circuit is turned off in the first step; a second voltage application step in which, from the end of the first step to the start of the second step, the plasma-side circuit is turned off and the holding-side circuit is turned on to apply the holding-side voltage to the holding unit; and a third voltage application step in which the plasma-side circuit is turned on to apply the plasma-side voltage to the plasma irradiation device and the holding-side circuit is turned on to apply the holding-side voltage to the holding unit in the second step. The method is characterized by carrying out the following. [Effects of the Invention]

[0016] Claim 1 ,2,4,5 According to the invention described in (1), the holding circuit applies a DC voltage to the resin to be irradiated with plasma, and the time for applying the DC voltage to the resin is set separately from the time for applying the plasma voltage to the plasma irradiation device, which converts gas introduced by the gas inlet into plasma. This allows for the timing at which the plasma irradiation device generates ions and radicals and irradiates the resin held in the holding device with the ions and radicals, as well as the potential state around the holding device and the resin held in the holding device, to be freely adjusted, thereby freely adjusting the timing and state at which the ions and radicals act on the resin while it is contained in the chamber. This allows for the radicals to be applied to the resin surface in an optimal state, providing high adhesion between the resin member and the metal layer on the member surface and firmly bonding them.

[0017] Claim 1 ,4 According to the invention described in the above, the application time adjusting unit of the plasma side circuit is During the period from the first step to the second step, when at least some of the atoms constituting the resin have been removed, to the resin in a state in which hydroxyl groups have been added,By setting the time during which the plasma-side circuit applies the plasma-side voltage to the holding section to be shorter than the time during which the holding-side circuit applies the holding-side voltage to the holding section, even before the plasma irradiation process using the plasma irradiation device, a potential difference can be generated between the area around the resin held in the holding section and the area in the chamber other than the area around the resin, making it possible to easily control the distribution of ions and radicals in the chamber to create an environment conducive to plasma generation in the plasma irradiation device. Furthermore, even after the plasma irradiation process, radicals generated by discharge due to the application of the holding-side voltage are present in the holding section, allowing for the reliable addition of hydroxyl groups. This allows various radicals to be added to the resin surface in an optimal state, providing high adhesion between the resin component and the metal layer on the component surface and firmly bonding them.

[0018] Claim 2 ,5 According to the invention described in The plasma processing apparatus is configured to perform at least a first step in which the resin is irradiated with plasma by the plasma-side circuit to remove at least some of the atoms constituting the resin, and a second step in which hydroxyl groups are added to the resin from which at least some of the atoms have been removed in the first step. The plasma-side circuit and the holding-side circuit are configured to turn on the plasma-side circuit to apply a plasma-side voltage to the plasma irradiation device and turn off the holding-side circuit in the first step. Then, from the end of the first step until the start of the second step, the plasma-side circuit is turned off and the holding-side circuit is turned on to apply a holding-side voltage to the holding unit. Then, in the second step, the plasma-side circuit is turned on to apply a plasma-side voltage to the plasma irradiation device and the holding-side circuit is turned on to apply a holding-side voltage to the holding unit. Even before the plasma irradiation step by the plasma irradiation device, a potential difference is generated between the periphery of the resin held in the holding unit and the area in the chamber other than the periphery of the resin, thereby easily controlling the distribution of ions and radicals in the chamber to create an environment conducive to plasma generation in the plasma irradiation device. Furthermore, even after the plasma irradiation process, radicals generated by the discharge generated by applying the holding voltage remain on the holding part, allowing the addition of hydroxyl groups to be steadily carried out. This allows various radicals to be added to the resin surface in an optimal state, providing high adhesion between the resin component and the metal layer on the component surface and firmly bonding them together.

[0019] Claim 3 According to the invention described in (1), in the process of imparting hydroxyl groups to a resin in a state in which at least some of the atoms constituting the resin have been released by irradiating the resin with plasma from a 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 a resin member and a metal layer on the surface of the member, thereby firmly bonding them together. [Brief explanation of the drawings]

[0023] [Figure 1] 1A and 1B are diagrams showing a schematic side view and a schematic top view of a substrate manufacturing system in which a plasma processing apparatus according to this embodiment is used; [Figure 2] FIG. 2 is a diagram schematically illustrating the plasma processing apparatus. [Figure 3] 3 is a flowchart of processing steps in the substrate manufacturing system. [Figure 4] 4 is a diagram showing a schematic diagram of the state during plasma generation in the second step in the plasma processing apparatus of FIG. [Figure 5] 10 is a diagram showing a state after plasma generation in the second step in the plasma processing apparatus shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0024] This embodiment is shown in Figures 1 to 5.

[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 substrate manufacturing system 100 is a manufacturing system comprising 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. Substrate 21 manufactured in substrate manufacturing system 100 has a metal layer such as metal film 23 formed on the front and back surfaces of resin substrate body 22, which is the 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-like piece of resin. A metal layer, such as a metal film 23, is formed on the surface of this substrate body 22 during the manufacturing process in the substrate manufacturing system 100 to form a substrate 21. The substrate manufacturing system 100 includes vacuum pre-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 (also described later), and gate valves 24, 24, 25, 26, 27, and 28. The first processing chamber 103 includes a pair of vacuum chambers 2. The vacuum chamber 2 on one side (the left side of FIG. 1) constitutes a processing chamber for processing the front side of the substrate body 22, and the vacuum chamber 2 on the other side (the right side of FIG. 1) constitutes a processing chamber for processing the back side of the substrate body 22. In this embodiment, the processing performed on the front and back sides of the substrate body 22 and the processing steps for those processing steps 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 in the vertical direction. Fig. 1 shows a state in which heaters 29 for the CVD method are provided symmetrically in the vertical direction 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 pre-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 pre-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 or a metal foil of the same thickness as the plating is pressed onto it offline (not shown), to form a metal layer such as the metal film 23 required for the circuit board.

[0030] [Configuration of plasma processing device] 2 is a diagram showing a schematic diagram of the plasma processing apparatus of this embodiment, which shows a first step S1 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 some of the atoms constituting the resin, and then adds hydroxyl groups to the resin, thereby improving the wettability of the resin surface. The improved wettability makes it possible to strengthen the bond when bonding a metal layer such as metal film 23 to the surface of the resin.

[0032] 2, for the sake of simplicity, 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, for the sake of simplicity, unless a particular distinction is required, only the vacuum chamber 2 on one side shown in FIG. 2 will be described, 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. 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. The plasma processing apparatus 1 also includes a gas inlet 15 and an exhaust unit 17 having an exhaust pump 16.

[0035] 2 schematically shows the directions in which the ions 7 and radicals 6 fly inside the vacuum chamber 2. This is also true for FIG. 4, which will be described later. As will be 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 aluminum alloy or stainless steel. The vacuum chamber 2 is strong enough 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 inside. The processing space of the vacuum chamber 2 is designed to create a vacuum by forcibly exhausting the gas inside to the outside by the exhaust pump 16. The vacuum chamber 2 is also connected to a ground 10. This ground 10 sets the reference potential for the holding-side circuit 13 and the plasma-side circuit 14.

[0037] The FPG 3 is disposed at the upper part of 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. For example, the FPG 3 described in International Publication No. 2014 / 175702 can be used.

[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 rotate about a rotation axis (not shown) so as 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, which will be 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 the second step S2 described later.

[0041] The second FPG 3b may be configured to have a rotation axis (not shown) to change the direction of plasma irradiation in the transport direction of the substrate body 22, or the first FPG 3a may be configured not to have a rotation axis (not shown) 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 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 to a portion of the holding table 4 that depends on the position of the substrate body 22. For example, in the second step S2, the holding-side voltage may be applied to the side of the holding table 4 near the second FPG 3b (the right side in FIG. 1). 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, the holding table 4 may be configured to have a first conductive range (not shown) near the first FPG 3a and a second conductive range (not shown) near the second FPG 3b, and to have a switch (not shown) that selectively switches the current from the holding-side power supply 8 between the first conductive range (not shown) and the second conductive range (not shown). However, any other configuration may be used to switch or change the position or range of the holding table 4 to which the holding-side voltage is applied.

[0045] The position and range of application of the holding side voltage to the holding table 4 in the first step S1 and the second step S2 may be any, and the holding side voltage may be configured to 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 top 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 emitted from the FPG 3 would also be irradiated onto the metal 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 if the effect of 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 positive electrode of the holding-side power supply 8 is connected to the holding table 4, and the negative electrode of the holding-side power supply 8 is 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 its positive electrode connected to the holder 4 side and its 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 to the plasma-side circuit 14 than the holding-side power supply 8.

[0049] The holding-side switch 11 and the plasma-side switch 12 are switches that switch the current flowing through 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 energized conductor 18 and the non-energized conductor 19. The energized conductor 18 is electrically connected to the holding-side power supply 8, and when the holding-side switch 11 is connected, the holding-side circuit 13 is turned ON, applying the voltage of the holding-side power supply 8 to the holding base 4. The non-energized conductor 19 is electrically connected to the holding base 4 without passing through the holding-side power supply 8, and when the holding-side switch 11 is connected, the holding-side circuit 13 is turned OFF, 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 configured to adjust the flow rate of current through the circuit from 0 to maximum in a stepwise or stepless manner. The holding-side switch 11 and the plasma-side switch 12 may be configured to be switched on and off by a control device (not shown) such as a microcomputer, or may be configured to be switched on and 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 section 17 is a metal pipe, and an exhaust pump 16 is provided midway through the pipe. When the exhaust pump 16 is activated, the exhaust section 17 discharges various gases, particles, dust, etc. present inside 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, but examples include fluororesins such as PTFE, PFA, and PCTFE, polyimide, and LCP. Specifically, in the case of fluororesins, the resin used as the material for the substrate body 22 contains fluorine and carbon, and the atoms that desorb from the hydrophobic surface of the resin are mainly fluorine and carbon. By breaking molecular bonds and adding hydroxyl groups to the activated surface, the hydrophobic surface of the fluororesin can be significantly hydrophilized. Furthermore, this phenomenon occurs only on the resin surface; the underlying fluorine-containing resin base material has high insulation properties, small dielectric constant and dielectric loss tangent, and low signal transmission loss, making it an excellent electrical substrate.

[0055] Furthermore, the resin used as the material for the substrate body 22 may contain, in addition to the above-mentioned materials, wholly aromatic polyester, and the atom that leaves 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. A mixed gas of nitrogen and argon is also acceptable. This is because nitrogen or argon ions tend to dissociate atoms constituting the resin from the surface of the resin used as the material for the substrate body 22.

[0057] [Processing process] 3 is a flowchart of the processing steps in substrate manufacturing system 100 of this embodiment. The substrate manufacturing steps of this embodiment will be described below 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 some of the atoms of the resin that makes up the substrate to be detached.

[0059] 1 is opened, and movable part 31 holding the end of substrate body 22 is attached to track part 32a in vacuum preparatory chamber 101. Gate valve 24 is closed, and the pressure inside vacuum preparatory chamber 101 is reduced. When the pressure inside vacuum preparatory chamber 101 becomes 10 Pa or less, 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 (upper surface side in FIG. 1a) of the substrate body 22 to remove at least some of the atoms of the resin that constitutes 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 that constitutes the substrate body 22.

[0062] Specifically, while the pressure inside the vacuum chamber 2 is reduced using the exhaust pump 16, processing gases of nitrogen and argon 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, which is equal to or greater than 0.1 Pa and equal to or less than 0.4 Pa.

[0063] 2, when the plasma-side switch 12 is turned on and the plasma-side circuit 14 is energized, a 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 below, so it is not energized and no plasma is generated in this step.

[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 direction of travel 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 maintains a dark discharge state, and the direction of travel of the ions 7 and radicals 6 can be controlled. Therefore, the pressure inside the vacuum chamber 2 is adjusted, for example, to between 0.1 Pa and 0.4 Pa. It should be noted that the pressure inside the vacuum chamber 2 is preferably about 0.3 Pa.

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

[0066] As shown in FIG. 2, the generated ions 7 and radicals 6 collide with the substrate body 22, and atoms of the resin that constitutes the substrate body 22 are detached from the surface of the substrate body 22, mainly due to the impact of the collisions of the ions 7. Most of the detached atoms are exhausted from the vacuum chamber 2 through the exhaust unit 17 by the exhaust of the exhaust pump 16. Some of the detached atoms float within the vacuum chamber 2, or after floating, adhere to the inner wall of the vacuum chamber 2 or components within the vacuum chamber 2. However, in this embodiment, the pressure within the vacuum chamber 2 is lower than the general glow discharge conditions, so there are almost no impurities (such as particles) floating within the chamber 2. This prevents impurities from adhering to the surface of the substrate body 2 and contaminating it.

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

[0068] [Powered on state after the first process is completed] Between the end of the first step S1 and 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, thereby energizing 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 to the holding-side circuit 13 a voltage 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 holder 4 and the substrate body 22 on the holder 4, which constitute the holding-side circuit 13. Meanwhile, the wall surface of the vacuum chamber 2, which constitutes the holding-side circuit 13, is at a lower potential than the holder 4 and the substrate body 22. The first FPG 3a is on the positive side, and the opposing holder 4 is also on the positive side, and since the voltages of both are close, plasma generation in the first FPG 3a is unlikely to occur. By applying a holding-side voltage from the holding-side power supply 8 between the end of the first step S1 and the start of the second step S2, which will be described later, it is possible to create an environment that facilitates plasma generation in the first FPG 3a.

[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, thereby simplifying the processing steps and miniaturizing the apparatus. However, the vacuum chamber 2 for performing the first step S1 and the vacuum chamber (not shown) for performing the second step S2 may be provided separately. Providing the vacuum chamber 2 for performing the first step S1 and the vacuum chamber (not shown) for performing the second step S2 separately has the effect of easily preventing a situation in which the desorbed components, which have been desorbed from the surface of the substrate body 22 in the first step S1, adhere to the surface of the substrate body 22 in the second step S2, even if they 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 the vacuum chamber 2, thereby preventing floating matter 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 inside the vacuum chamber 2. When the supply of nitrogen and / or argon used in the first step S1 and present inside the vacuum chamber 2 is stopped, it is immediately discharged outside the vacuum chamber 2 by the exhaust pump 16. Then, while introducing water vapor as the processing gas into the vacuum chamber 2 from the gas inlet 15, the exhaust pump 16 is controlled to adjust the pressure inside the vacuum chamber 2 in the second step S2 so that the pressure inside the vacuum chamber 2 is 30% to 50% of the pressure in the first step S1. This is because performing the processing in the second step S2, described below, at a pressure of 30% to 50% of the pressure in the first step S1 allows radicals 6 (hydroxyl radicals) in the plasma of the processing gas to optimally attach to the surface.

[0075] After the process gas is introduced into the vacuum chamber 2, as shown in FIG. 4, the holding-side switch 11 is switched from its non-conductive side conductor 19 to its conductive side conductor 18 to turn on the holding-side circuit 13, thereby applying the voltage of the holding-side power supply 8 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 process 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, thereby energizing the FPG 3 from the plasma-side power supply 9. As shown in FIG. 1, the application of the plasma-side voltage to the second FPG 3b activates the second FPG 3b, generating plasma of the process gas filling the vacuum chamber 2.

[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, but 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, and the potential of the vacuum chamber 2 (forming the plasma-side circuit 14 and the holding-side circuit 13) relative to the second FPG 3b and the holding table 4 is formed in the negative direction. Furthermore, the potential difference between the second FPG 3b and the holding table 4 is decreasing, while the potential differences between the FPG 3b 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 processing gas in the vacuum chamber 2 by the second FPG 3b, most of the positive ions 7 in the plasma move toward the vacuum chamber 2 where the potential difference is large, as shown in Figure 5. On the other hand, the radicals 6 (hydroxyl radicals) with no polarity in the plasma are irradiated onto 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 of the vacuum chamber 2 and the substrate body 22 is hardly irradiated with 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 hydroxyl groups causes the hydroxyl groups to chemically bond stably with 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 onto which hydroxyl groups have been introduced in the second step S2 preferably has a contact angle with water of 10° or less, more preferably 6° or less, and an appropriate irradiation time is set accordingly. In this way, the surface of the substrate body 22 and the metal film 23 are firmly adhered to each other in the third step S3 and the fourth step S4 described below.

[0081] [Pressure and temperature in the first and second steps] It is preferable that both the first and second steps are performed with the vacuum chamber 2 under reduced pressure. After the first step, it is also preferable that the second step be performed while maintaining the reduced pressure. This is because hydroxyl groups can be introduced into the surface of the resin that constitutes the substrate body 22 while maintaining the activated state of the surface of the resin that constitutes the substrate body 30 in the first step. The hydrophilicity of the resin surface that has undergone 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% or more and 50% or less 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 travel, and in the second step, ions are hardly irradiated onto the surface of the substrate body 22, and hydroxyl radicals are more likely to irradiate onto the surface of the substrate body 22.

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

[0084] [Powered on state after the second process] In the second step S2, even after the plasma-side power supply 9 is turned OFF and the application of the second DC voltage to the second FPG 3b is stopped, 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, resulting in a positive potential on the holding table 4 side of the holding-side circuit 13 and a negative potential on the vacuum chamber 2 side. This causes positive ions in the vacuum chamber 2 to be attracted to the wall of the vacuum chamber 2, where the potential difference is greater. This prevents hydroxyl groups introduced onto the surface of the substrate body 22 by ion bombardment from being re-detached, even after the plasma-side power supply 9 is turned OFF. Furthermore, by applying a positive voltage from the holding-side power supply 8 to the holding table 4 and the substrate body 22, a slight glow discharge generated on the holding table 4 can also attach any remaining hydroxyl groups.

[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 holder 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 time can be long enough to prevent ions from causing detachment from the surface of the substrate body 22. For ease of understanding, the following description assumes that the first FPG 3a is used for the first process S1 and the right-hand FPG 3 is used for the second process S2. However, a second FPG 3b may also be used for the first process S1. In this case, it is desirable that the plasmas generated by the first FPG 3a and the second FPG 3b are parallel to each other to prevent interference. Furthermore, it is preferable to apply a positive voltage to the area of ​​the support pedestal 4 facing the second FPG 3b for the second process S2, rather than to the entire surface of the support pedestal 4 (i.e., it is desirable to form the aforementioned second conductive area (not shown) in an area substantially equal to the area facing the second FPG 3b). This configuration prevents changes in the process environment due to discharge from the support pedestal 4 in the area not facing the second FPG 3b. When the second FPG 3b is swung depending on the position of the substrate main body 22, the position of the corresponding holder 4 changes, so it is desirable to change the range to which the voltage is applied to the holder 4 (the second conductive range (not shown) described above) depending on the irradiation position of the second FPG 3b. Similarly, when the first FPG 3a is swung, it is desirable to change the range to which the voltage is applied to the holder 4 (the first conductive range (not shown) described above) depending on the irradiation position of the first FPG 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 processing chamber 104 where the third step is performed. After the substrate body 22 is accommodated in the second processing chamber 104, the holding side switch 11 is connected to the non-conductive 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 processing in a third step (step S3, hereinafter referred to as "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 auxiliary chamber 102, and the gate valve 27 is closed. After the pressure inside the vacuum auxiliary chamber 102 is returned to atmospheric pressure, the gate valve 38 is opened and the completed substrate 21 is removed.

[0089] In the 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, such as copper, silver, or 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 has formed the metal film 23 on the surface of the substrate body 22. If the metal film is vapor-deposited in the third step S3, in the fourth step S4, the same metal is further plated or bonded by thermocompression bonding to form a metal layer such as the metal film 23 on the surface of the substrate body 22.

[0091] 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 due to the atmosphere. This allows for a high degree of adhesion.

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

[0093] [Action and effect] As described above, in this embodiment, the time during which the holding-side circuit 13, which applies a holding-side voltage as a DC voltage to the substrate body 22, which is the resin to be irradiated with plasma, applies the holding-side voltage to the resin held by the holding table 4, and the time during which the plasma-side circuit 14, which is configured to apply a plasma-side voltage as a DC voltage to the FPG 3, which plasma-enhances the gas introduced by the gas inlet 15, applies the plasma-side voltage to the FPG 3, are set to be separate. This makes it possible to freely adjust the timing at which the FPG 3 generates ions and radicals and irradiates 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, and to freely adjust 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. This allows radicals to be applied in a suitable state to the surface of the substrate body 22, 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, thereby firmly bonding them together.

[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 released 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 radicals to be provided to the surface of the substrate body 22 in an appropriate 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 firmly bonding them together.

[0095] In this embodiment, the ON / OFF control of the plasma-side switch 12, which serves as an application time adjuster for the plasma-side circuit 14, sets the time during which the plasma-side circuit 14 applies the plasma-side voltage to be shorter than the time during which the holding-side circuit 13 applies the holding-side voltage to the holding table 4. This generates a potential difference between the periphery of the substrate body 22 held on the holding table 4 and the area other than the periphery of the substrate body 22 in the vacuum chamber 2, even before and after the plasma irradiation process by the FPG 3, making it possible to easily control the distribution of ions and radicals in the vacuum chamber 2 over a long period of time. This allows various types of radicals to be applied 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 firmly bonding them together.

[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 surface of the substrate body 22 with plasma, the holding side voltage is used to adjust the potential state of the substrate body 22, controlling the state of approach and separation of ions and radicals from the surface of the substrate body 22, thereby enabling appropriate control of 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 FPG 3 as a plasma-side voltage to generate plasma, which irradiates the surface of the resin with positive ions, causing the surface of the resin to be desorbed by ion collisions. Furthermore, by applying a positive voltage to the resin as a retention-side voltage, the potential difference between the FPG 3 and the resin is reduced, and the potential difference between the FPG 3 and portions other than the substrate body 22 is relatively increased. This attracts positive ions to portions other than the substrate body 22, preventing continued ion collisions with the surface of the substrate body 22. This allows for appropriate control of plasma processing and surface modification of the substrate body 22.

[0099] In this embodiment, by applying a holding side voltage to at least a portion 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 favorable conditions.

[0100] It goes without saying that the above-described embodiment is merely an example of the present invention, and does not mean that the present invention is limited to only the above-described 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 plasma processing method of this embodiment are used, for example, in the manufacture of circuit boards used in mobile phones that communicate large volumes of information at high speed. Fluororesin has the second lowest dielectric constant after air, making fluororesin substrates particularly suitable as materials for high-frequency substrates. Compared to circuit boards made of other common materials, circuit boards made of fluororesin have low dielectric constants and dielectric loss tangents, and low dielectric loss, even when high-frequency currents are passed through them.

[0102] When the plasma processing apparatus and plasma processing method of this embodiment are applied to the manufacture of fluororesin substrates, the hydrophilicity of the manufactured substrate is improved, and adhesion to copper wiring is improved, providing a circuit substrate that can withstand use in high frequency bands. This technology applicable to use in high frequency bands can be applied not only to mobile phone bodies but also to substrates used in mobile phone base stations, substrates for communication in homes, factories, or for regional use, and substrates for millimeter-wave radar used in autonomous driving of automobiles or drones. The plasma processing apparatus and plasma processing method of this embodiment can also be used to manufacture substrates in a variety of 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 that irradiates a surface of a resin present in a chamber with plasma to improve the wettability of the surface of the resin, a holding circuit having a holding portion that holds the resin to be irradiated with the plasma, and applying a holding voltage to the held resin; a gas inlet for introducing a gas into the chamber; a plasma irradiation device for converting the gas into plasma, and a plasma-side circuit configured to apply a plasma-side voltage as a DC voltage to the plasma irradiation device; the plasma treatment device is configured to perform a first step of irradiating the resin with plasma from a plasma side circuit to remove at least a portion of atoms constituting the resin, and a second step of imparting hydroxyl groups to the resin from which at least a portion of the atoms have been removed in the first step; a time during which the holding-side circuit applies the holding-side voltage to the resin and a time during which the plasma-side circuit applies the plasma-side voltage to the plasma irradiation device are set to be separate from each other; The plasma side circuit is characterized in that it has an application time adjustment unit 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, during the period from when the resin in the first step has been subjected to at least some of the atoms constituting the resin being released to when hydroxyl groups are added in the second step.

2. 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, a holding circuit having a holding portion that holds the resin to be irradiated with the plasma, and applying a holding voltage to the held resin; a gas inlet for introducing a gas into the chamber; a plasma irradiation device for converting the gas into plasma, and a plasma-side circuit configured to apply a plasma-side voltage as a DC voltage to the plasma irradiation device; the plasma treatment device is configured to at least perform a first step of irradiating the resin with plasma from a plasma side circuit to remove at least a portion of atoms constituting the resin, and a second step of imparting hydroxyl groups to the resin from which at least a portion of the atoms have been removed in the first step; The plasma side circuit and the holding side circuit are In the first step, a first voltage application unit turns on the plasma-side circuit to apply the plasma-side voltage to the plasma irradiation device and turns off the holding-side circuit; a second voltage application unit that turns off the plasma-side circuit and turns on the holding-side circuit to apply the holding-side voltage to the holding unit during the period from the end of the first step to the start of the second step; a third voltage application unit that turns on the plasma-side circuit to apply the plasma-side voltage to the plasma irradiation device and turns on the holding-side circuit to apply the holding-side voltage to the holding unit in the second step; A plasma processing apparatus comprising:

3. 3. The plasma processing apparatus according to claim 1, wherein the plasma side circuit and the holding side circuit are configured so that the time for applying the holding side voltage and the time for applying the plasma side voltage are separate in order to perform the second process of adding hydroxyl groups to the resin that has undergone the first process.

4. a chamber containing a resin to be irradiated with plasma; a holding circuit having a holding portion that holds the resin to be irradiated with the plasma, and applying a holding voltage to the held resin; a gas inlet for introducing a gas into the chamber; a plasma irradiation device for converting the gas into plasma, and a plasma-side circuit configured to apply 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 plasma treatment method is configured to carry out a first step of irradiating the resin with plasma from a plasma side circuit to remove at least a portion of atoms constituting the resin, and a second step of imparting hydroxyl groups to the resin from which at least a portion of the atoms have been removed in the first step, a time during which the holding-side circuit applies the holding-side voltage to the resin and a time during which the plasma-side circuit applies the plasma-side voltage to the plasma irradiation device are set to be separate from each other; A plasma processing method characterized in that an application time adjustment unit provided in the plasma side circuit for adjusting the time for which the plasma side circuit applies the plasma side voltage is set so that the time for which the plasma side circuit applies the plasma side voltage is shorter than the time for which the holding side voltage is applied to the holding side circuit, during the period from when the resin in the first step has been subjected to the removal of at least a portion of the atoms constituting the resin to when hydroxyl groups are added in the second step.

5. 1. A plasma processing method for improving the wettability of a surface of a resin present in a chamber by irradiating the surface of the resin with plasma, comprising: The plasma processing apparatus for performing the plasma processing method includes: a holding circuit having a holding portion that holds the resin to be irradiated with the plasma, and applying a holding voltage to the held resin; a gas inlet for introducing a gas into the chamber; a plasma irradiation device for converting the gas into plasma, and a plasma-side circuit configured to apply a plasma-side voltage as a DC voltage to the plasma irradiation device; the plasma treatment device is configured to at least perform a first step of irradiating the resin with plasma from a plasma side circuit to remove at least a portion of atoms constituting the resin, and a second step of imparting hydroxyl groups to the resin from which at least a portion of the atoms have been removed in the first step; The plasma side circuit and the holding side circuit are a first voltage application step in which the plasma-side circuit is turned on to apply the plasma-side voltage to the plasma irradiation device and the holding-side circuit is turned off in the first step; a second voltage application step in which, during the period from the end of the first step to the start of the second step, the plasma-side circuit is turned off and the holding-side circuit is turned on to apply the holding-side voltage to the holding unit; a third voltage application step in which, in the second step, the plasma-side circuit is turned on to apply the plasma-side voltage to the plasma irradiation device and the holding-side circuit is turned on to apply the holding-side voltage to the holding unit; A plasma processing method comprising:

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