US20160186324A1

US20160186324A1 - Resin article and method of manufacturing resin article

Info

Publication number: US20160186324A1
Application number: US14/973,804
Authority: US
Inventors: Taisuke Iwashita
Original assignee: Canon Components Inc
Current assignee: Canon Components Inc
Priority date: 2014-12-25
Filing date: 2015-12-18
Publication date: 2016-06-30
Also published as: JP2016121388A; JP5830596B1

Abstract

There is provided with a method of manufacturing a resin article. A surface of a resin article is modified such that a plating layer can be deposited. In the modification, ultraviolet light is irradiated on the resin article, and shock is applied to the resin article after the ultraviolet light is irradiated.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention
The present invention relates to a resin article and a method of manufacturing a resin article.
2. Description of the Related Art
A resin article having a plating layer that has a plating layer formed on the resin article is useful as a circuit board or a conductive film or the like. Also, the uses of a resin article having a plating layer are not limited to these; for example, a resin article having a plating layer of zinc oxide or the like can be used as a functional film such as a UV-cutting material or a photocatalyst.
Japanese Patent Laid-Open No. 2008-094923 describes a method of manufacturing a printed circuit board using surface modification by ultraviolet light. Specifically, first, an ultraviolet light lamp is irradiated on an entire surface of a cyclo-olefin polymer material, to enable easier depositing of electroless plating. Then, a plating layer is formed by successively performing alkali treatment, conditioning treatment, pre-dipping treatment, catalyst providing treatment, activation treatment, electroless copper plating, heat treatment, and electroless copper plating, and the result is used as material of a printed circuit board. By using a photolithography step and an etching step to process the obtained plating layer so as to have a predetermined pattern, it is possible to provide a plating layer having a predetermined pattern on the cyclo-olefin polymer material.

SUMMARY OF THE INVENTION

According to an embodiment of the present invention, a method of manufacturing a resin article comprises: modifying a surface of a resin article such that a plating layer can be deposited, the modifying comprises: irradiating ultraviolet light on the resin article, and applying shock to the resin article after the ultraviolet light is irradiated.
According to another embodiment of the present invention, a resin article comprises: a resin article; and a plating layer, wherein the plating layer is manufactured according to a method comprising: irradiating ultraviolet light on the resin article; applying shock to the resin article after the ultraviolet light is irradiated; and performing electroless plating on the resin article to which the shock has been applied.
According to still another embodiment of the present invention, a resin article having a plating layer comprises: a resin article having a modified portion that was modified by irradiating ultraviolet light and applying a shock; and a plating layer that was formed on the modified portion.
Further features of the present invention will become apparent from the following description of exemplary embodiments (with reference to the attached drawings).

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A to 1D illustrate a method of manufacturing a resin article having a plating layer according to one embodiment.

FIG. 2 is a flowchart of a method of manufacturing a resin article having a plating layer according to one embodiment.

DESCRIPTION OF THE EMBODIMENTS

Alkali treatment is performed using a strong alkaline solution such as a sodium hydroxide aqueous solution or the like having a concentration of approximately 50 g/L. This sort of strong alkaline solution is not easy to handle, and therefore has problems in that operation is complicated and requires careful attention, and also has problems in that a strong alkaline solution has a high environmental burden and disposal costs. Also, it is not easy to apply a plating method using alkali treatment to a resin article having low resistance to strong alkali. On the other hand, according to investigations by the inventors of the present application, it was found that when alkali treatment is omitted, the plating layer may not be uniformly deposited, and there is a reduction in adhesiveness of the deposited plating layer to the resin article.
According to an embodiment of the present invention, a plating layer can be formed on a resin article by a simple method.
Below is a description of embodiments in which the present invention is applicable, with reference to drawings. However, the scope of the present invention is not limited by the below embodiments.
According to a modification method according to the present embodiment, the surface of a resin article is modified such that electroless plating will be deposited. By using this modification method, it is possible to manufacture a resin article whose surface has been modified such that a plating layer will be deposited. The modification method according to the present embodiment includes an irradiation step and a shock applying step. Also, a method of manufacturing a resin article having a plating layer according to the present embodiment includes a modification step of modifying the surface of a resin article using the modification method according to the present embodiment, and a plating step. Below, these steps will be described in detail with reference to FIGS. 1A to 1D and FIG. 2.
(Irradiation Step)
In an irradiation step (S210), ultraviolet light is irradiated on the surface of a resin article. For example, when ultraviolet light 180 is irradiated on a resin article 110 shown in FIG. 1A, a modified portion 120 is formed at a location where the ultraviolet light was irradiated, as shown in FIG. 1B.
Ultraviolet light may be irradiated on the entire surface of the resin article 110, or may be irradiated on only a portion of the surface of the resin article 110. For example, in a case where a plating layer 130 is intended to be formed in a portion of the surface of the resin article 110, ultraviolet light can be irradiated on the portion where the plating layer 130 is intended to be formed. Specifically, by arranging a mask that has a UV-transmissive portion corresponding to the shape of a portion where ultraviolet light will be irradiated among the surface of the resin article 110, and irradiating ultraviolet light via this mask, it is possible to selectively modify a desired portion. Thus, such that an electroless plating layer will be selectively deposited in a portion where the plating layer 130 is intended to be formed, the modified portion 120 is formed in a portion of the surface of the resin article 110 where the plating layer 130 is intended to be formed.
Irradiation of ultraviolet light is performed under conditions in which modification of the surface of the resin article 110 will proceed. For example, in one embodiment, ultraviolet light is irradiated on the resin article 110 in an atmosphere containing at least one of oxygen and ozone. Also, in one embodiment, such that generation of active oxygen is promoted, ultraviolet light having a wavelength of 243 nm or less is irradiated. In one embodiment, such that generation of active oxygen is further promoted, ultraviolet light having a primary wavelength of 243 nm or less is irradiated. In the present specification, primary wavelength refers to a wavelength having the highest intensity in a region of 243 nm or less. Specifically, in the case of a low pressure mercury lamp the primary wavelength is 185 nm.
When ultraviolet light is irradiated, oxygen in the atmosphere is decomposed, generating ozone. Further, active oxygen is generated in the course of ozone decomposing. Also, at the surface of the resin article 110, bonds in the molecules that constitute the resin article 110 are broken. At this time, molecules that constitute the resin article 110 react with active oxygen, and the surface of the resin article 110 oxidizes, that is, at the surface of the resin article 110 bonds such as C—O bonds, C═O bonds, and C(═O)—O bonds (carboxyl group skeletal structure portion) are formed. Such a hydrophilic group increases the chemical adhesiveness of the resin article 110 and the plating layer 130. Also, since a portion made brittle by oxidation of the surface of the resin article 110 will come off in a later step such as a shock applying step (S220) for example, a fine rough face is formed in a portion where ultraviolet light has been irradiated. Because of this rough face, physical adhesiveness of the plating layer 130 to the resin article 110 increases due to an anchoring effect. Further, a portion that has been modified can selectively adsorb catalyst ions when performing electroless plating.
Energy of photons of a specific wavelength is expressed by the following formulas.
E=Nhc/λ(KJ·mol⁻¹)
N=6.022×10²³mol⁻¹ (Avogadro's constant)
h=6.626×10⁻³⁷KJ·s (Plank's constant)
c=2.988×10⁸m·s⁻¹ (speed of light)
λ=light wavelength (nm)
Here, the bond energy of oxygen molecules is 490.4 KJ·mol⁻¹. From the photon energy formula, this bond energy is about 243 nm when converted to light wavelength. This indicates that oxygen molecules in the atmosphere will absorb ultraviolet light with a wavelength of 243 nm or less and decompose. Thus, ozone O₃is generated. Further, active oxygen is generated in the course of ozone decomposing. At this time, when there is ultraviolet light with a wavelength of 310 nm or less, ozone is efficiently decomposed, and active oxygen is generated. Further, ultraviolet light with a wavelength of 254 nm decomposes ozone most efficiently.
O₂+hν (243 nm or less)→O(3P)+O(3P)
O₂+O (3P)→O₃(ozone)
O₃+hν (310 nm or less)→O₂+O(1D) (active oxygen)
O(3P): ground state oxygen atom
O(1D): excited oxygen atom (active oxygen)
Such ultraviolet light can be irradiated using an ultraviolet light lamp or an ultraviolet light LED or the like that continuously radiates ultraviolet light. Examples of an ultraviolet light lamp include a low pressure mercury lamp, an excimer lamp, and the like. A low pressure mercury lamp can irradiate ultraviolet light having a wavelength of 185 nm and 254 nm. Also, for reference, an example of an excimer lamp that can be used in air is given below. Ordinarily an Xe₂excimer lamp is used as an excimer lamp.
Xe₂excimer lamp: wavelength 172 nm
KrBr excimer lamp: wavelength 206 nm
KrCl excimer lamp: wavelength 222 nm
On the other hand, in another embodiment, irradiation of ultraviolet light on the resin article 110 can be performed in another gas atmosphere, for example, such as an amine compound gas atmosphere like ammonia or an amide compound gas atmosphere. By performing irradiation in an amine compound gas atmosphere or an amide compound gas atmosphere, it is possible to oxidize the surface of the resin article 110, that is, possible to generate bonds including nitrogen atoms at the surface of the resin article 110. That is, the surface of the resin article 110 is modified so as to include nitrogen atoms, so adhesiveness with the plating layer improves, so it is possible to perform selective plating in an irradiated portion. In a case where modification is performed by ultraviolet light in an altered pressure or under compound gas after isolating the item to be processed from an atmosphere at normal pressure it is possible to suitably select a wavelength appropriate for the reaction. On the other hand, irradiating ultraviolet light having a wavelength of 243 nm or less in air including oxygen is advantageous because modification can be performed with low cost.
When irradiating ultraviolet light on the resin article 110, ultraviolet light irradiation conditions are controlled such that the irradiation amount becomes a desired value. The irradiation amount of ultraviolet light is selected such that the plating layer 130 will be deposited in the modified portion 120 in a plating step (S230) described later. Specifically, the irradiation amount of ultraviolet light can be controlled by changing the irradiation time, or by changing the output, lamp quantity, irradiation distance, or the like of the ultraviolet light lamp.
In one embodiment, from the viewpoint of adequately causing plating to be deposited in a shorter time period, the irradiation amount of ultraviolet light in the irradiation step is set to at least 400 mJ/cm²and not more than 1,600 mJ/cm²at the primary wavelength. For example, in one embodiment in which the irradiation intensity of ultraviolet light at the primary wavelength is 1.35 mW/cm², the irradiation time of ultraviolet light is set to at least 5 minutes and not more than 20 minutes. Also, the irradiation intensity of ultraviolet light, in order to promote modification of the resin article 110, in one embodiment is set to at least 0.1 mW/cm², and in another embodiment is set to at least 0.3 mW/cm², and in still another embodiment is set to at least 1.0 mW/cm². On the other hand, the irradiation intensity of ultraviolet light, in order to prevent the surface of the resin article 110 from being greatly roughened, in one embodiment is set to not more than 30 mW/cm², and in another embodiment is set to not more than 5.0 mW/cm², and in still another embodiment is set to not more than 3.0 mW/cm². Below, unless specifically stated otherwise, the irradiation amount and irradiation intensity of ultraviolet light refer to values on the surface of the resin article 110 at the primary wavelength.
Also, in still another embodiment, after performing irradiation of ultraviolet light using a first method (first irradiation) in a portion of the surface of the resin article 110, ultraviolet light is irradiated using a second method (second irradiation) in a region that includes a portion of the surface of the resin article 110. For example, it is possible to irradiate intense ultraviolet light in the first method, and possible to irradiate weaker ultraviolet light than in the first method in the second method.
For example, in one embodiment, after irradiating (first irradiation) an ultraviolet light laser beam in a portion of the surface of the resin article 110, ultraviolet light is irradiated (second irradiation) from an ultraviolet light lamp or an ultraviolet light LED in a region that includes a portion of the surface of the resin article 110. As a specific example, first, an ultraviolet light laser beam is irradiated in a portion of the surface of the resin article 110 where the plating layer 130 is intended to be formed. Next, ultraviolet light is irradiated from an ultraviolet light lamp or an ultraviolet light LED in a region that includes the portion of the surface of the resin article 110 where the plating layer 130 is intended to be formed. The ultraviolet light from an ultraviolet light lamp or an ultraviolet light LED may be irradiated in a larger region that encompasses the portion where the plating layer 130 is intended to be caused to be deposited, and for example may be irradiated on the entire resin article 110. On the other hand, the ultraviolet light from an ultraviolet light lamp or an ultraviolet light LED may be selectively irradiated in the portion of the surface of the resin article 110 where the plating layer 130 is intended to be formed. With this sort of method as well, it is possible to form the modified portion 120 in a portion where an ultraviolet light laser beam has been irradiated, which is a portion of the surface of the resin article 110, such that the plating layer 130 will be selectively deposited in the portion of the surface where an ultraviolet light laser beam has been irradiated.
This method is advantageous for being able to precisely control the shape of the plating layer 130 to be obtained, in order to selectively perform irradiation using a laser beam having a high degree of rectilinearity. Also, the temperature of the resin article 110 increases less easily when using a laser than when using a lamp. Therefore, it is possible to suppress a shift in the position of ultraviolet light irradiation due to differences in the thermal expansion coefficient between the photomask and the resin article 110.
On the other hand, there are cases where plating is not deposited in a portion where ultraviolet light was irradiated by merely irradiating ultraviolet light having a high energy density, such as with an ultraviolet light laser beam, on the surface of the resin article 110. The surface of the resin article 110 is modified by irradiating an ultraviolet light laser beam, but the modified layer is eliminated due to the ablation effect in an ultraviolet light laser beam. Therefore, it is possible that only a certain amount of modification is obtained, and an amount of modification sufficient for plating to be deposited cannot be obtained. Ablation is a phenomenon where the surface of material is removed by evaporation. By using ultraviolet light from an ultraviolet light lamp or an ultraviolet light LED, which can easily introduce oxygen atoms to the resin article 110, it is possible to more strongly modify a portion where the plating layer 130 is intended to be formed, such that the plating layer 130 will be deposited on the resin article 110.
In one embodiment, the wavelength of the ultraviolet light laser beam is not more than 243 nm, such that generation of active oxygen is promoted. Likewise, in one embodiment, the wavelength of ultraviolet light from an ultraviolet light lamp or an ultraviolet light LED also is not more than 243 nm, such that generation of active oxygen is promoted.
In this case, the irradiation amount of ultraviolet light is adjusted such that the plating layer 130 will be deposited in a portion that has been modified using both the ultraviolet light laser and the ultraviolet light lamp or the ultraviolet light LED in a plating step (S230) described later. On the other hand, the irradiation amount of ultraviolet light is adjusted such that the plating layer 130 will not be deposited in a portion where only the ultraviolet light lamp was irradiated. In a portion where the laser beam is being intensely irradiated, modification is already progressing, so modification such that the plating layer 130 will be deposited is performed with weak modifying treatment, for example treatment in which ultraviolet light is irradiated for a short time from an ultraviolet light lamp or an ultraviolet light LED or the like. On the other hand, in a portion where the laser beam has not been irradiated, modification does not progress much with only weak modifying treatment performed additionally, and so the plating layer 130 will not be deposited. Accordingly, even in a case where modifying treatment is performed uniformly on the entire resin article 110, in the plating step (S230) described later, it is possible to selectively cause the plating layer 130 to be deposited in the modified portion 120 where the laser beam has been irradiated.
The irradiation intensity of the irradiated ultraviolet light laser beam, in order to prevent the surface of the resin article 110 from being greatly roughened, in one embodiment is set to not more than 1.0×10¹⁵W/cm². Also, in order to promote modification of the surface of the resin article 110, the irradiation intensity of the irradiated ultraviolet light laser beam, in one embodiment is set to at least 1.0×10⁵W/cm². Also, the irradiation intensity of the ultraviolet light laser beam per pulse, in one embodiment is set to at least 10 mJ/cm², and in one embodiment is set to not more than 10,000 mJ/cm². For the same reason, the irradiation intensity of ultraviolet light from the ultraviolet light lamp or the ultraviolet light LED, in one embodiment is set to at least 0.1 mW/cm², and in another embodiment is set to at least 0.3 mW/cm², and in still another embodiment is set to at least 1.0 mW/cm². On the other hand, the irradiation intensity of ultraviolet light from the ultraviolet light lamp or the ultraviolet light LED, in one embodiment is set to not more than 30 mW/cm², and in another embodiment is set to not more than 5.0 mW/cm², and in still another embodiment is set to not more than 3.0 mW/cm².
The plating deposit conditions are variable depending on the type of plating solution, the type of the resin article 110, the degree of contamination of the surface of the resin article 110, the concentration, temperature, pH, and age-related degradation of the plating solution, fluctuation in output of the ultraviolet light lamp, focus shift of the ultraviolet light laser, and the like. Accordingly, the irradiation amount of ultraviolet light can be determined such that plating is selectively deposited only in a portion where the plating layer 130 is intended to be formed.
In another embodiment, after irradiating (first irradiation) ultraviolet light from an excimer lamp in a portion of the surface of the resin article 110, ultraviolet light is irradiated (second irradiation) from an ultraviolet light lamp or an ultraviolet light LED in a region that includes a portion of the surface of the resin article 110. For example, after irradiating ultraviolet light for a short time from the excimer lamp via a photomask, it is possible to irradiate ultraviolet light from an ultraviolet light lamp or an ultraviolet light LED, not via a photomask, in a region that includes the portion where ultraviolet light was irradiated from the excimer lamp. Thus, it is possible to modify the surface of the resin article 110 such that the plating layer 130 will be deposited in the portion where ultraviolet light was irradiated from the excimer lamp. The excimer lamp has properties such that the surface of the resin article 110 can be modified in a short time, but a chemical adsorption group is difficult to generate in some of the surface. Accordingly, according to this sort of embodiment, it is possible to suppress a shift in the position of ultraviolet light irradiation due to differences in the thermal expansion coefficient between the photomask and the resin article 110. For example, in one embodiment, an Xe₂excimer lamp having a wavelength of 172 nm is used as the above-described excimer lamp, and a low pressure mercury lamp having wavelengths of 185 nm and 254 nm is used as the above-described ultraviolet light lamp.
The resin article 110 used in the present embodiment is not particularly limited, as long as the resin article 110 has a surface formed with resin material that can be modified by ultraviolet light. Examples of the resin material include a cyclo-olefin polymer or a polyolefin such as polystyrene, a polyester such as polyethylene terephthalate, a polyvinyl such as polyvinyl chloride, a polycarbonate, a polyimide, or the like. In a case of using a resin material having a low alkali resistance such as a polycarbonate or polyimide, when performing alkali treatment using a strong alkali, it is possible that the material will be damaged. Also, in a case of using a resin material having a low alkali resistance, when performing alkali treatment using a strong alkali, it is possible that a portion where ultraviolet light has not been irradiated will also be damaged, and so the plating layer 130 will easily be deposited there. On the other hand, as described later, in the present embodiment it is not necessary to use a strong alkali, and in fact it is not necessary to use alkali treatment itself, so this embodiment is also applicable to a resin material having a low alkali resistance, and the plating layer 130 can be selectively caused to be deposited in a desired portion.
The shape of the resin article 110 also is not particularly limited. For example, the resin article 110 may have a film-like shape or may have a plate-like shape. Further, the thickness of the resin article 110 also is not particularly limited. Also, it is not necessary to configure the resin article 110 with only resin. That is, in one embodiment, the resin article 110 is a composite material article having a coated structure obtained by coating the surface of another material article with resin material. As a specific example of a composite material article, there is a composite material article in which the surface of a metal material article has been coated with a resin material.
In one embodiment, the resin article 110 has a smooth surface. Due to the resin article 110 having a smoother surface, a more uniform plating layer 130 is formed by plating. By using such a smooth plating layer 130 as conductive wiring, it is possible to reduce high frequency signal loss. According to a method of modifying the surface of the resin article 110 using ultraviolet light as in the present embodiment, nanometer-order fine roughness is formed in the surface of the resin article 110. In one embodiment, surface roughness of the modified portion 120 immediately before performing electroless plating is 10 nm or less. Also, in a resin article 100 having a plating layer according to the present embodiment, surface roughness of the resin article 110 surface at the interface of the resin article 110 and the plating layer 130 is 10 nm or less. Roughness formed in this way is expected to be remarkably small compared to micrometer-order roughness that, for example, is obtained by irradiating a high-intensity visible laser beam on the surface of a resin article, or is formed by treatment with chromic acid or the like, and so a high degree of surface smoothness is expected. In the present specification, surface roughness refers to arithmetic mean roughness Ra defined by JIS B0601: 2001.
(Shock Applying Step)
In a shock applying step (S220), as shown in FIG. 1C, a shock 190 is applied to the resin article 110 that has been irradiated with ultraviolet light. By applying a shock to the resin article 110, the plating layer 130 becomes more easily deposited in the modified portion 120. It is conceivable that a reason for this is that a fine rough face is formed by loss of the surface of the modified portion 120 made brittle by irradiation of ultraviolet light. It is presumed that because of this fine rough face, physical adhesiveness of the modified portion 120 and the plating layer 130 increases due to an anchoring effect. In one embodiment, a shock is applied directly to the modified portion 120. However, as long as the plating layer 130 becomes easily deposited in the modified portion 120, a shock may be applied directly to a portion other than the modified portion 120 such that a shock is also applied to the modified portion 120 via the resin article 110.
The type of shock applied to the resin article 110 is not particularly limited as long as the plating layer 130 becomes easily deposited. In one embodiment, a physical shock is applied as the shock. An example of a physical shock is a mechanical shock. Examples of a mechanical shock include applying a pressure wave to the resin article 110 or placing a shock applying body in contact with the resin article 110. Examples of a shock applying body include an air bubble or a shock applying member. Below, these shocks will be described in detail.
In one embodiment, a pressure wave treatment that applies a pressure wave to the resin article 110 is performed. An example of a pressure wave is a sound wave. In one embodiment, an ultrasonic wave treatment that irradiates an ultrasonic wave on the resin article 110 is performed such that the plating layer 130 will be more easily deposited. The pressure wave can be irradiated on the resin article 110 in an arbitrary medium. For example, it is possible to irradiate an ultrasonic wave on the resin article 110 in water or an aqueous solution using an ultrasonic wave irradiation device.
The irradiation time of the pressure wave is not particularly limited as long as the plating layer 130 becomes easily deposited. In one embodiment the irradiation time of the pressure wave is set to at least 2 minutes, such that the plating layer 130 becomes easily deposited. Also, such that adhesiveness of the plating layer 130 and the resin article 110 improves, in one embodiment the irradiation time of the pressure wave is set to at least 5 minutes, and in still another embodiment the irradiation time of the pressure wave is set to at least 10 minutes. The irradiation time does not particularly have an upper limit, and for example may be set to 60 minutes or less.
In one embodiment, air bubble treatment that places an air bubble in contact with the resin article 110 is performed. The type of air bubble is not particularly limited, but in one embodiment a microbubble treatment using microbubbles is used in order to perform uniform treatment. Microbubbles have properties of producing a shock wave when the bubbles are broken, so by using microbubble treatment it is expected that a large shock will be applied. Microbubbles refers to air bubbles having a diameter of approximately at least 1 μm and not more than 1,000 μm. In order to perform uniform treatment, the diameter of microbubbles in one embodiment is not more than 300 μm, and in still another embodiment is not more than 100 μm. On the other hand, in order to increase the shock and improve treatment efficiency, the diameter of microbubbles in one embodiment is at least 3 μm, and in still another embodiment is at least 10 μm.
Air bubbles can be generated using an ordinary air bubble generating apparatus. For example, microbubbles can be generated using an ordinary microbubble generating apparatus. Air bubble treatment can be performed in a liquid, by using an air bubble generating apparatus whose position has been adjusted such that air bubbles are applied to the resin article 110 that has been immersed in the liquid. The type of liquid is not particularly limited, and for example can be water or an aqueous solution. The type of air bubbles is not particularly limited, and for example air, oxygen, or nitrogen bubbles can be used. Also, with the expectation of further modifying a portion where ultraviolet light has been irradiated, it is also possible to use ozone bubbles.
The air bubble treatment time is not particularly limited as long as the plating layer 130 becomes easily deposited. In one embodiment the air bubble treatment time is set to at least 0.5 minutes, such that the plating layer 130 becomes easily deposited. Also, such that adhesiveness of the plating layer 130 and the resin article 110 improves, in one embodiment the air bubble treatment time is set to at least 1 minute, and in still another embodiment the air bubble treatment time is set to at least 2 minutes. The air bubble treatment time does not particularly have an upper limit, and for example may be set to 60 minutes or less.
Nanobubbles, which are even finer bubbles than microbubbles, may also be used, and nanobubbles refers to air bubbles having a diameter of approximately at least 1 nm and not more than 1,000 nm. The diameter of nanobubbles in one embodiment is not more than 300 nm, and in still another embodiment is not more than 100 nm.
In one embodiment, a shock applying member is placed in contact with the resin article 110. By contact of the shock applying member, a shock is applied to the portion where ultraviolet light has been irradiated. For example, by rubbing the modified portion 120 of the resin article 110 using the shock applying member, a friction force can be applied to the portion of the resin article 110 where ultraviolet light was irradiated. Also, by projecting the shock applying member to the modified portion 120 of the resin article 110, it is possible to apply a compressive force to the portion of the resin article 110 where ultraviolet light was irradiated. Further, by affixing then removing the shock applying member from the modified portion 120 of the resin article 110, it is possible to apply a tensile force to the portion of the resin article 110 where ultraviolet light was irradiated. Examples of a specific embodiment include brush treatment in which the modified portion 120 is rubbed with a brush, tape treatment in which tape is applied then peeled away from the modified portion 120, and the like.
The shock applying treatment can be performed in an arbitrary medium such as pure water, and in one embodiment, the shock applying treatment can be performed in a medium that promotes deposition of the plating layer 130. For example, pressure wave treatment or air bubble treatment can be performed in a treatment solution that promotes deposition of the plating layer 130. By using this sort of treatment solution, deposition of the plating layer 130 is further promoted, so it is possible to shorten the time of shock applying treatment. Also, it is possible to improve adhesiveness of the plating layer 130 and the resin article 110. A method of performing shock applying treatment in a treatment solution in this way is particularly advantageous for a resin article 110 in which it is difficult to form roughness by shock applying treatment because a polyimide or the like has high mechanical strength.
For example, by performing shock applying treatment in an alkaline treatment solution, in which it is possible to perform shock applying treatment in the alkaline treatment solution, particularly pressure wave treatment or air bubble treatment, deposition of the plating layer 130 is promoted. The composition of the alkaline treatment solution is not particularly limited, but in one embodiment, an easily handled alkaline treatment solution having a pH of less than 13 is used, and in still another embodiment an alkaline treatment solution having a pH of less than 12.5 is used. Thus, in the shock applying treatment, it is not necessary to use a strong alkaline such as a sodium hydroxide aqueous solution having a concentration of approximately 50 g/L.
The shock applying treatment can also be performed in a treatment solution that contains a surfactant. The type of surfactant is not particularly limited. By performing shock applying treatment in a treatment solution that contains a surfactant, particularly pressure wave treatment or air bubble treatment, deposition of the plating layer 130 is promoted. In still another embodiment, shock applying treatment is performed in an alkaline treatment solution that contains a surfactant. An example of such an alkaline treatment solution that contains a surfactant is a conditioner solution used in electroless plating. When shock applying treatment is performed in a conditioner solution (when performing ultrasonic wave conditioner treatment), by omitting conditioner treatment in a plating step (S230) described later, it is possible to reduce the number of treatment steps.
(Plating Step)
In a plating step (S230), electroless plating is performed on the resin article 110 that has been modified. As a result, as shown in FIG. 1D, the plating layer 130 is formed in the modified portion 120 of the surface of the resin article 110 that was produced in the modifying step (S210) and the shock applying step (S220). Thus, a resin article 100 having a plating layer is manufactured. In the modifying step (S210) and the shock applying step (S220), selective modification has been performed such that the plating layer 130 is deposited in a desired modified portion 120. Accordingly, even in a case where, for example, the entire resin article 110 has been immersed in a plating solution, the plating layer 130 is selectively deposited in a desired modified portion 120. Also, a plating layer is not deposited in a portion adjacent to the desired portion. Accordingly, it is not necessary to perform patterning on the plating layer by a method such as photolithography and etching after forming the plating layer 130.
In one embodiment, the plating layer 130 is formed by an electroless plating method. The specific electroless plating method is not particularly limited. Examples of electroless plating methods that can be adopted include an electroless plating method employing a formalin electroless plating bath, and an electroless plating method in which hypophosphorous acid, which has a slow deposit speed but is easily managed, is used as a reducing agent. As more specific examples of the electroless plating method, there are electroless nickel plating, electroless copper plating, electroless copper-nickel plating, electroless zinc oxide plating, and the like. The plating layer 130 to be formed, in one embodiment, is a metal film, and may also be a ceramic film such as a zinc oxide plating layer. By modifying the resin article 110 as described above, adhesiveness of the modified portion 120 and the deposited plating layer 130 improves.
In one embodiment, the electroless plating can be performed by the below method.
1. (Conditioner Treatment) The resin article 110 is immersed in a solution containing a binder of the resin article 110 and catalyst ions. Examples of the binder include a cation polymer or the like.
2. (Activator Treatment) The resin article 110 is immersed in a solution including catalyst ions. Examples of catalyst ions include a palladium complex such as hydrochloric acid palladium complex, or the like.
3. (Accelerator Treatment) The resin article 110 is immersed in a solution containing a reducing agent, causing reduction and depositing of catalyst ions. Examples of the reducing agent include hydrogen gas, dimethylamine borane, sodium borohydride, and the like.
4. (Electroless Plating Treatment) The plating layer 130 is deposited on the deposited catalyst.
Electroless plating according to this sort of method can be performed using, for example, an electroless plating solution set, such as a Cu—Ni plating solution set “AISL” made by JCU Co.
In another embodiment, as catalyst ions, a palladium complex is used that easily adheres to the modified portion 120 and at least partially has a positive charge. In order to improve adhesiveness to the modified portion 120, in one embodiment, a solution is used that includes palladium complex ions having a positive charge in the solution. An example of a palladium complex that at least partially has a positive charge is a complex in which amine ligands are in coordination bonds. Also, another example of a palladium complex that at least partially has a positive charge is a palladium basic amino acid complex.
In this case, because a palladium complex that partially has a positive charge directly affixes to the modified portion of the resin article 110, by immersing the resin article 110 in a binder solution, it is not necessary to increase the affinity of the resin article 110 and catalyst ions. Also, because the binder is easily left in a portion where ultraviolet light has not been irradiated, sometimes a plating layer may be deposited in an unintended portion. Thus, as the catalyst ions, it is advantageous for ease of selectively depositing the plating layer 130 to use a palladium complex at least partially having a positive charge. That is, when using this sort of catalyst, unintended deposition of the plating layer 130 is reduced in a portion where the plating layer 130 is not intended to be provided.
In another embodiment, the plating layer 130 may also be formed by a high speed electroless plating method. According to a high speed electroless plating method, it is possible to form a thicker plating layer. In still another embodiment, on the plating layer 130 that has been formed by electroless plating, plating is caused to be deposited by additionally using an electroplating method. According to this method, it is possible to form a still thicker plating layer 130. The specific method of electroplating is not particularly limited.
There is no special limitation on the thickness of the plating layer 130 to be obtained. A plating layer 130 of an appropriate thickness is formed according to the application of the resin article 100 having a plating layer to be obtained.
The resin article 100 having a plating layer obtained in this way includes the resin article 110 having the modified portion 120 that was modified by irradiating ultraviolet light and applying a shock, and the plating layer 130 that was formed on the modified portion 120. The resin article 100 having a plating layer obtained in this way can be used in various applications such as a wiring board, a conductive film, UV-cutting material, or a photocatalyst.
As in the present embodiment, in an embodiment in which a shock applying step is used, it is not necessary to perform alkali treatment using a strong alkali, and in fact it is not necessary to perform alkali treatment at all. Therefore, it is possible to manufacture the resin article 100 having a plating layer with a simpler method. Also, the present embodiment, in which it is not necessary to perform alkali treatment using a strong alkali, is also applicable to the resin article 110 having low alkali resistance. In one embodiment, between the irradiation step (S210) and the plating step (S230), that is, after formation of the modified portion 120 by irradiating ultraviolet light and before formation the plating layer 130, alkali treatment using an alkali solution having a pH of 13 or greater is not performed.

EXAMPLES

Example 1-1

A cyclo-olefin polymer material (made by Zeon Corp., ZeonorFilm ZF-16, thickness 100 μm, surface roughness Ra=0.47 nm), which is a resin material, was used as the substrate.
First, before performing surface modification, to clean the substrate surface, ultrasonic cleaning was performed on the substrate for 3 minutes in pure water at 50° C., and then the substrate was dried.
Next, in air, ultraviolet light from an ultraviolet light lamp was irradiated on a portion of the substrate, via a quartz chrome mask that was placed on the substrate. Details of the ultraviolet light lamp (low pressure mercury lamp) used in this example are given below. The surface roughness of the substrate after irradiating ultraviolet light was 0.26 nm.
Low pressure mercury lamp: UV-300 made by Samco Corp. (primary wavelengths 185 nm, 254 nm)
Irradiation distance: 3.5 cm
Irradiation time: 10 minutes
Illuminance at irradiation distance 3.5 cm:

- 5.40 mW/cm²(254 nm)
- 1.35 mW/cm²(185 nm)

Next, ultrasonic wave treatment was performed on the substrate after ultraviolet light irradiation. Specifically, the substrate was treated for 5 minutes in pure water at 50° C., using an ultrasonic wave cleaning device (made by Sharp Corp., UT-206H, frequency 37 kHz, output 100%).
Next, a binder treatment was performed on the substrate. Specifically, a conditioner solution used in a plating solution set “AISL” made by JCU Co. was heated to 50° C., and the substrate was immersed for 2 minutes. Afterward, the substrate was rinsed with pure water.
Next, a catalyst ion treatment was performed on the substrate. Specifically, an activator solution used in a plating solution set “AISL” made by JCU Co. was heated to 50° C., and the substrate was immersed for 2 minutes. Afterward, the substrate was rinsed with pure water.
Next, a reducing treatment was performed on the substrate. Specifically, an accelerator solution used in a plating solution set “AISL” made by JCU Co. was heated to 50° C., and the substrate was immersed for two minutes. Afterward, the substrate was rinsed with pure water.
Next, electroless copper-nickel plating was performed on the substrate. Specifically, an electroless Cu—Ni plating solution used in a Cu—Ni plating solution set “AISL” made by JCU Co. was heated to 60° C., and the substrate was immersed for 5 minutes. Afterward, the substrate was rinsed in pure water, and dried. Thus, a resin article having a plating layer was manufactured.
When the obtained resin article having a plating layer was observed, a plating layer was uniformly deposited in a location where ultraviolet light was irradiated, and a plating layer had not been deposited in a location where ultraviolet light was not irradiated.

Examples 1-2, 1-3

Except for performing the ultrasonic wave treatment for 8 minutes in Example 1-2 and performing the ultrasonic wave treatment for 10 minutes in Example 1-3, a resin article having a plating layer was manufactured in the same manner as in Example 1-1. When the obtained resin article having a plating layer was observed, a plating layer was uniformly deposited in a location where ultraviolet light was irradiated, and a plating layer had not been deposited in a location where ultraviolet light was not irradiated.

Comparative Example 1

Except for not performing the ultrasonic wave treatment, a resin article having a plating layer was manufactured in the same manner as in Example 1-1. When the obtained resin article having a plating layer was observed, a plating layer was deposited in a peripheral portion of a region where ultraviolet light was irradiated, but a plating layer had not been deposited in a central portion of the irradiated region.
In the resin article having a plating layer that was manufactured in Examples 1-1 to 1-3 and Comparison Example 1, adhesiveness of the plating layer to the substrate was evaluated. A tape testing method according to JIS H 8504: 1996 was used for evaluating adhesiveness. When tape was affixed to and peeled away from the resin article having a plating layer that was manufactured in Comparison Example 1, the plating layer was easily removed. When tape was affixed to and peeled away from the resin article having a plating layer that was manufactured in Examples 1-1 and 1-2, partial removal of the plating layer was observed. On the other hand, when tape was affixed to and peeled away from the resin article having a plating layer that was manufactured in Example 1-3, removal of the plating layer was not observed. Thus, it was confirmed that it is possible to cause plating to be sufficiently deposited in a location where ultraviolet light was irradiated by performing ultrasonic wave treatment, and adhesiveness of the plating layer to the substrate improves by increasing the ultrasonic wave treatment time.

Example 2-1

Except for performing microbubble treatment instead of the ultrasonic wave treatment, a resin article having a plating layer was manufactured in the same manner as in Example 1-1. In the microbubble treatment, the substrate was immersed in pure water at normal temperature such that microbubbles generated from a microbubble generation apparatus (made by Kansai Automation Devices Co., MBLL-11-102VS) were applied to the substrate. In this state, the substrate was treated for 1 minute with microbubbles.
When the obtained resin article having a plating layer was observed, a plating layer was uniformly deposited in a location where ultraviolet light was irradiated, and a plating layer had not been deposited in a location where ultraviolet light was not irradiated.

Examples 2-2, 2-3, 2-4

Except for performing the microbubble treatment for 2 minutes in Example 2-2, performing the microbubble treatment for 10 minutes in Example 2-3, and performing the microbubble treatment for 20 minutes in Example 2-4, a resin article having a plating layer was manufactured in the same manner as in Example 2-1. When the obtained resin article having a plating layer was observed, a plating layer was uniformly deposited in a location where ultraviolet light was irradiated, and a plating layer had not been deposited in a location where ultraviolet light was not irradiated.
In the resin article having a plating layer that was manufactured in Examples 2-1 to 2-4, adhesiveness of the plating layer to the substrate was evaluated using a tape testing method according to JIS H 8504: 1996. For all of the resin articles having a plating layer that were manufactured in Examples 2-1 to 2-4, even when tape was affixed and peeled away, no removal of the plating layer was observed. Thus, it was confirmed that it is possible to cause plating having high adhesive strength to be sufficiently deposited in a location where ultraviolet light was irradiated by performing microbubble treatment.

Example 3

Except for performing tape treatment instead of the ultrasonic wave treatment, a resin article having a plating layer was manufactured in the same manner as in Example 1-1. In the tape treatment, tape was affixed to a location of the substrate where ultraviolet light was irradiated, and afterward the affixed tape was peeled away.
When the obtained resin article having a plating layer was observed, a plating layer was uniformly deposited in a location where ultraviolet light was irradiated, and a plating layer had not been deposited in a location where ultraviolet light was not irradiated.

Example 4-1

Except for performing ultrasonic wave conditioner treatment instead of performing ultrasonic wave treatment and conditioner treatment, a resin article having a plating layer was manufactured in the same manner as in Example 1-1. In the ultrasonic wave conditioner treatment, using an ultrasonic wave cleaning device (made by Sharp Corp., UT-206H, frequency 37 kHz, output 100%), the substrate was treated for two minutes in a conditioner solution used in a plating solution set “AISL” made by JCU Co. that was heated to 50° C. Afterward, the substrate was rinsed with pure water.
When the obtained resin article having a plating layer was observed, a plating layer was uniformly deposited in a location where ultraviolet light was irradiated, and a plating layer had not been deposited in a location where ultraviolet light was not irradiated.

Examples 4-2, 4-3

Except for performing the ultrasonic wave conditioner treatment for 5 minutes in Example 4-2, and performing the ultrasonic wave conditioner treatment for 10 minutes in Example 4-3, a resin article having a plating layer was manufactured in the same manner as in Example 4-1. When the obtained resin article having a plating layer was observed, a plating layer was uniformly deposited in a location where ultraviolet light was irradiated, and a plating layer had not been deposited in a location where ultraviolet light was not irradiated.
In the resin article having a plating layer that was manufactured in Examples 4-1 to 4-3, adhesiveness of the plating layer to the substrate was evaluated using a tape testing method according to JIS H 8504: 1996. When tape was affixed to and peeled away from the resin article having a plating layer that was manufactured in Example 4-1, removal of the plating layer was observed. When tape was affixed to and peeled away from the resin article having a plating layer that was manufactured in Example 4-2, slight removal of the plating layer was observed. When tape was affixed to and peeled away from the resin article having a plating layer that was manufactured in Example 4-3, removal of the plating layer was not observed. Thus, it was confirmed that it is possible to cause plating to be sufficiently deposited in a location where ultraviolet light was irradiated by performing ultrasonic wave conditioner treatment, and adhesiveness of the plating layer to the substrate improves by increasing the ultrasonic wave conditioner treatment time. Further, by comparing Examples 1-1 and 4-2, it is understood that adhesiveness of the plating layer to the substrate improves more in a case where ultrasonic wave conditioner treatment is performed than in a case where ultrasonic wave treatment and conditioner treatment are performed separately.

Example 5-1

Except for using a polyimide material (NEOPULIM L-3430, made by Mitsubishi Gas Chemical Co.) instead of a cyclo-olefin polymer material as the substrate, a resin article having a plating layer was manufactured in the same manner as in Example 4-3.
When the obtained resin article having a plating layer was observed, a plating layer was uniformly deposited in a location where ultraviolet light was irradiated, and a plating layer had not been deposited in a location where ultraviolet light was not irradiated.
In the resin article having a plating layer that was manufactured in Example 5-1, adhesiveness of the plating layer to the substrate was evaluated using a tape testing method according to JIS H 8504: 1996. Even when tape was affixed to and peeled away from the resin article having a plating layer that was manufactured in Example 5-1, removal of the plating layer was not observed.

Example 5-2

Except for using a polyimide material (NEOPULIM L-3430, made by Mitsubishi Gas Chemical Co.) instead of a cyclo-olefin polymer material as the substrate, a resin article having a plating layer was manufactured in the same manner as in Example 1-3.
When the obtained resin article having a plating layer was observed, a tendency was seen for a plating layer to be deposited in a location where ultraviolet light was irradiated, but there was low adhesiveness between the substrate and the plating layer, and locations where the plating layer exfoliating away from the substrate were seen in some places.
By comparing Example 5-1 and Example 5-2, it is understood that adhesiveness of the plating layer to the substrate improves more in a case where ultrasonic wave conditioner treatment is used than in a case where ultrasonic wave treatment and conditioner treatment are performed separately. Also, it is understood that ultrasonic wave conditioner treatment is suitable for a case where plating is performed on a polyimide.
While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.
This application claims the benefit of Japanese Patent Application No. 2014-263304, filed Dec. 25, 2014, which is hereby incorporated by reference herein in its entirety.

Claims

What is claimed is:

1. A method of manufacturing a resin article, comprising:

modifying a surface of a resin article such that a plating layer can be deposited, the modifying comprises:

irradiating ultraviolet light on the resin article, and

applying shock to the resin article after the ultraviolet light is irradiated.

2. The method according to claim 1, wherein in applying the shock, a pressure wave is applied to the resin article.

3. The method according to claim 2, wherein the pressure wave is an ultrasonic wave.

4. The method according to claim 1, wherein in applying the shock, an air bubble is applied to the resin article.

5. The method according to claim 4, wherein the air bubble is a microbubble.

6. The method according to claim 2, wherein the shock is applied in an alkaline solution.

7. The method according to claim 2, wherein the shock is applied in a solution containing a surfactant.

8. The method according to claim 1, wherein in applying the shock, a shock applying member is put in contact with the resin article.

9. The method according to claim 1, wherein in the irradiating, the ultraviolet light is irradiated in an atmosphere that contains at least one of oxygen or ozone.

10. The method according to claim 1, wherein a primary wavelength of the ultraviolet light is 243 nm or less.

11. The method according to claim 1, wherein in the irradiating, ultraviolet light is irradiated on a portion of the surface of the resin article such that a plating layer can be selectively deposited in the portion of the surface of the resin article.

12. The method according to claim 1, wherein the irradiating includes irradiating an ultraviolet light laser beam on a portion of the surface of the resin article, and irradiating ultraviolet light from an ultraviolet light lamp or an ultraviolet light LED on a region that includes the portion of the surface of the resin article, such that a plating layer can be selectively deposited in the portion of the surface of the resin article.

13. The method according to claim 1, further comprising:

performing electroless plating on the resin article that has been modified.

14. A resin article comprising:

a resin article; and

a plating layer, wherein the plating layer is manufactured according to a method comprising:

irradiating ultraviolet light on the resin article;

applying shock to the resin article after the ultraviolet light is irradiated; and

performing electroless plating on the resin article to which the shock has been applied.

15. A resin article, comprising:

a resin article having a modified portion that was modified by irradiating ultraviolet light and applying a shock; and

a plating layer that was formed on the modified portion.