RESIN ARTICLE WITH PLATING FILM AND METHOD FOR MANUFACTURING RESIN ARTICLE
There is provided with a method for manufacturing a resin article provided with a plating film. A resin article is irradiated with ultraviolet rays. A catalyst is applied to the resin article, while applying shock to the resin article that has been irradiated with the ultraviolet rays. An electroless plating is performed on the resin article.
Field of the Invention
The present invention relates to a resin article with a plating film and a method for manufacturing the resin article.
Description of the Related Art
A resin article with a plating film having a plating film provided on the resin article is useful as a circuit board, a conductive film, or the like. Also, the usage of a resin article with a plating film is not limited to these, and for example, a resin article with a plating film provided with a plating film 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 for manufacturing a printed circuit board with surface modification by ultraviolet rays. Specifically, first, irradiating an entire surface of a cycloolefin polymer material with an ultraviolet ray lamp facilitates deposition of electroless plating. Then, a plating film is formed by sequentially performing alkali treatment, conditioning treatment, pre-dipping treatment, catalyst applying treatment, activation treatment, electroless copper plating, heating treatment, and copper electrolytic plating, and the formed plating film is used as a material for a printed circuit board. The obtained plating film is processed in a photolithography step and an etching step so as to have a predetermined pattern, and thereby the plating film having the predetermined pattern can be provided on a cycloolefin polymer material.
SUMMARY OF THE INVENTIONAccording to an embodiment of the present invention, a method for manufacturing a resin article provided with a plating film comprises: irradiating the resin article with ultraviolet rays; applying a catalyst to the resin article while applying shock to the resin article that has been irradiated with the ultraviolet rays; and performing electroless plating on the resin article.
According to another embodiment of the present invention, a resin article with a plating film manufactured according to the method comprises: irradiating the resin article with ultraviolet rays; applying a catalyst to the resin article while applying shock to the resin article that has been irradiated with the ultraviolet rays; and performing electroless plating on the resin article.
According to still another embodiment of the present invention, a method for manufacturing a resin article comprises: irradiating the resin article with ultraviolet rays; and applying, after the irradiating, the catalyst to a surface of the resin article such that a plating film is deposited, while applying bubbles and/or pressure waves against the resin article.
Further features of the present invention will become apparent from the following description of exemplary embodiments with reference to the attached drawings.
The alkali treatment is performed using a strong alkali solution such as an aqueous solution of sodium hydroxide having a concentration of about 50 g/L. There are issues in that complicated and careful operations are required due to difficulty in handling of such an alkali solution, and in that the alkali solution has a high environmental load and its disposal cost is high. Also, it has not been easy to apply a plating method in which alkali treatment is used for a resin article that has low resistance to alkali. Also, the conditioning treatment is performed using a conditioner liquid containing a binder for the resin article and a catalyst, such as an ion polymer. However, performing the conditioning treatment is also a factor that complicates the plating step and increases costs.
Incidentally, according to studies by the inventor of this invention, it was found that if the alkali treatment and the conditioning treatment are omitted, a plating film is not uniformly deposited, and that the adhesion of the deposited plating film to the resin article decreases.
According to one embodiment of the present invention, it is possible to provide a new treatment method that facilitates deposition of a plating film on the resin article.
Hereinafter, embodiments to which the present invention can be applied will be described with reference to the drawings. However, the scope of the present invention is not limited to the following embodiments.
According to a manufacturing method according to this embodiment, electroless plating is deposited on a surface of a resin article. The manufacturing method according to this embodiment includes an irradiating step, an applying step, and a plating step. Hereinafter, these steps will be described in detail with reference to
Irradiating Step
In an irradiating step (step S210), the surface of the resin article is irradiated with ultraviolet rays. For example, when a resin article 110 shown in
The entire surface of the resin article 110 may be irradiated with ultraviolet rays, or a portion of the surface of the resin article 110 may be irradiated with ultraviolet rays. For example, if a plating film 130 is to be formed on a portion of the surface of the resin article 110, the portion on which the plating film 130 is to be formed can be irradiated with ultraviolet rays. Specifically, a mask having an ultraviolet ray transmitting portion corresponding to the shape of the portion of the surface of the resin article 110 that is to be irradiated with ultraviolet rays is disposed on the resin article, and the portion is irradiated with ultraviolet rays via this mask, thereby enabling a desirable portion to be selectively modified. In this manner, the modification portion 120 is formed on the portion of the surface of the resin article 110 on which the plating film 130 is to be formed, such that an electroless plating film is selectively deposited on the portion on which the plating film 130 is to be formed.
Irradiation of the ultraviolet rays is performed under conditions in which modification of the surface of the resin article 110 proceeds. For example, in one embodiment, the resin article 110 is irradiated with ultraviolet rays in an atmosphere including at least one of oxygen and ozone. Also, in one embodiment, ultraviolet rays having a wavelength of 243 nm or less are emitted such that generation of active oxygen is promoted. In one embodiment, ultraviolet rays having a dominant wavelength of 243 nm or less are emitted such that generation of active oxygen is further promoted. In this specification, the dominant wavelength indicates a wavelength at which the intensity of the ultraviolet rays is highest in a region having a wavelength of 250 nm or less. Specifically, in the case of a low pressure mercury vapor lamp, the dominant wavelength is 185 nm.
When ultraviolet rays are emitted, oxygen in the atmosphere is decomposed into ozone. Moreover, active oxygen is generated in the process in which ozone undergoes decomposition. Bonds in molecules that constitute the resin article 110 also are cleaved on the surface of the resin article 110. At this time, the molecules that constitute the resin article 110 react with the active oxygen, and the surface of the resin article 110 is oxidized, that is, a C—O bonds, a C═O bonds, a C(═O)—O bonds (carboxyl group skeletal structure portion), and the like are formed on the surface of the resin article 110. Such a hydrophilic group increases chemical absorption between the resin article 110 and the plating film 130. Also, a minute rough surface is formed on the portion that has been irradiated with ultraviolet rays, due to a portion that has been embrittled by oxidation of the surface of the resin article 110 separating therefrom in the subsequent step such as an applying step (step S220), for example. Physical absorption between the resin article 110 and the plating film 130 increases due to an anchoring effect of this rough surface. Furthermore, catalyst ions can be selectively absorbed by the modified portion when electroless plating is performed.
The energy of photons having a specific wavelength is expressed with the following equations.
E=Nhc/λ (KJ·mol−1)
N=6.022×1023 mol−1 (Avogadro's number)
h=6.626×10−37 KJ·s (Planck constant)
c=2.988×108 m·s−1 (light velocity)
λ=wavelength of light (nm)
Here, the binding energy of an oxygen molecule is 490.4 KJ·mol−1. When this binding energy is converted to the wavelength of light with the equations of the energy of photons, the wavelength of light is approximately 243 nm. This indicates that the oxygen molecules in the atmosphere absorb ultraviolet rays having a wavelength of 243 nm or less and are decomposed. Accordingly, ozone O3 is generated. Moreover, in the process of decomposition of ozone, active oxygen is generated. At this time, if ultraviolet rays having a wavelength of 310 nm or less are present, the ozone is efficiently decomposed, and active oxygen is generated. Furthermore, ultraviolet rays having a wavelength of 254 nm most efficiently decompose ozone.
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): oxygen atom in ground state
O(1D): excited oxygen atom (active oxygen)
Such ultraviolet rays can be emitted using an ultraviolet ray lamp, an ultraviolet ray LED, or the like for emitting ultraviolet rays continuously. Examples of the ultraviolet ray lamp include a low pressure mercury vapor lamp and an excimer lamp. The low pressure mercury vapor lamp can emit ultraviolet rays having wavelengths of 185 nm and 254 nm. Also, as a reference, examples of the excimer lamp that can be used in an air atmosphere are listed below. In general, a Xe2 excimer lamp is used as the excimer lamp.
Xe2 excimer lamp: wavelength 172 nm
KrBr excimer lamp: wavelength 206 nm
KrCl excimer lamp: wavelength 222 nm
On the other hand, in another embodiment, the resin article 110 can be irradiated with ultraviolet rays in an atmosphere of another gas, such as an atmosphere of a gaseous amine compound such as ammonia, or an atmosphere of a gaseous amide compound. Irradiation in the atmosphere of the gaseous amine compound or the atmosphere of the gaseous amide compound makes it possible to oxidize the surface of the resin article 110, that is, to generate bonds including nitrogen atoms on the surface of the resin article 110. That is, since the surface of the resin article 110 is modified to include the nitrogen atoms, and absorption with a plating layer is improved, an irradiated portion can be selectively plated. If a processing object is separated from an air atmosphere having the normal pressure, and is modified by ultraviolet rays by changing the pressure and enclosing compound gas, a wavelength that is suitable for a reaction can be selected as appropriate. On the other hand, emission of ultraviolet rays having a wavelength of 243 nm or less in an air atmosphere including oxygen is advantageous in that modification can be performed at low cost.
When the resin article 110 is irradiated with the ultraviolet rays, the conditions for irradiation of the ultraviolet rays are controlled such that the irradiation dose is a desirable value. The irradiation dose of the ultraviolet rays is selected such that the plating film 130 is deposited on the modification portion 120 in a plating step (step S230), which will be described later. Specifically, the irradiation dose of ultraviolet rays can also be controlled by changing the irradiation time, the output of the ultraviolet ray lamp, the number of ultraviolet ray lamps, the irradiation distance, or the like.
In one embodiment, from the viewpoint of allowing plating to be sufficiently deposited in a shorter time period, the irradiation dose of ultraviolet rays in the irradiating step is not less than 400 mJ/cm2 and not more than 1600 mJ/cm2 at the dominant wavelength. For example, in one embodiment in which the irradiation intensity of the ultraviolet rays in the dominant wavelength is 1.35 mW/cm2, the irradiation time of the ultraviolet rays is not less than 15 minutes and not more than 20 minutes. Also, in order to promote the modification of the resin article 110, the irradiation intensity of the ultraviolet rays is not less than 0.1 mW/cm2 in one embodiment, not less than 0.3 mW/cm2 in another embodiment, and not less than 1.0 mW/cm2 in still another embodiment. On the other hand, in order to prevent the surface of the resin article 110 from becoming rough, the irradiation intensity of the ultraviolet rays is not more than 30 mW/cm2 in one embodiment, not more than 5.0 mW/cm2 in another embodiment, and not more than 3.0 mW/cm2 in still another embodiment. Hereinafter, unless otherwise stated, the irradiation dose and intensity of the ultraviolet rays indicate values on the surface of the resin article 110 in the resin article.
Also, in still another embodiment, after a portion of the surface of the resin article 110 is irradiated with ultraviolet rays using a first method (first irradiation), a region including the portion of the surface of the resin article 110 is irradiated with ultraviolet rays using a second method (second irradiation). For example, strong ultraviolet rays can be emitted in the first method, and ultraviolet rays weaker than in the first method can be emitted in the second method.
For example, in one embodiment, after a portion of the surface of the resin article 110 is irradiated with ultraviolet ray laser (first irradiation), a region including the portion of the surface of the resin article 110 is irradiated with ultraviolet rays from an ultraviolet ray lamp or an ultraviolet ray LED (second irradiation). As a specific example, first, a portion of the surface of the resin article 110 on which the plating film 130 is to be formed is irradiated with the ultraviolet ray laser. Next, a region including the portion of the surface of the resin article 110 on which the plating film 130 is to be formed is irradiated with ultraviolet rays from the ultraviolet ray lamp or the ultraviolet ray LED. A region wider than the region that includes the portion on which the plating film 130 is to be deposited may be irradiated with ultraviolet rays from the ultraviolet ray lamp or the ultraviolet ray LED, or the entire resin article 110 may be irradiated with ultraviolet rays, for example. On the other hand, the portion of the surface of the resin article 110 on which the plating film 130 is to be formed may be selectively irradiated with ultraviolet rays from the ultraviolet ray lamp or the ultraviolet ray LED. Even with such a method, the modification portion 120 can be formed on the portion that has been irradiated with the ultraviolet ray laser, the portion being a portion of the surface of the resin article 110, such that the plating film 130 is selectively deposited on the portion of the surface that has been irradiated the ultraviolet ray laser.
This method allows selective irradiation using the laser whose beam has high straightness, and is thus advantageous in precisely controlling the shape of the plating film 130 that is obtained. Also, in the case where the laser is used, it takes a shorter time to modify the surface of the resin article 110, compared to the case where a lamp is used, and thus the degree of temperature rise of the resin article 110 is low, and the degree of expansion of the resin article 110 is also suppressed. Thus, it is possible to suppress a shift in the irradiation position of the ultraviolet rays, the shift being caused by a difference in thermal expansion coefficient between the photomask and the resin article 110 that may possibly occur in the case where ultraviolet rays from a lamp are emitted via the photomask. Also, though a nanometer-order minute rough surface, laser irradiation makes it possible to form the modification portion 120 having a larger surface roughness than in the case where only an ultraviolet ray lamp or the like is used. This makes it possible to improve a bonding strength between the modification portion 120 and the plating film 130.
On the other hand, in some cases, only irradiating the surface of the resin article 110 with ultraviolet rays having a large energy density such as an ultraviolet ray laser does not cause deposition of plating on the portion that has been irradiated with ultraviolet rays. Although the surface of the resin article 110 is modified by being irradiated with the ultraviolet ray laser, the ultraviolet ray laser has an abrasion effect, and thus the modified layer is removed. Thus, there is a possibility that a given modification amount or more will not be obtained, and that modification will not be sufficiently performed to an extent such that plating is deposited. Abrasion refers to a phenomenon where the surface of a material is removed due to evaporation. Usage of ultraviolet rays emitted from an ultraviolet ray lamp or an ultraviolet ray LED for easily introducing oxygen atoms into the resin article 110 makes it possible to strongly modify the portion on which the plating film 130 is to be formed such that the plating film 130 is deposited on the resin article 110.
In one embodiment, the wavelength of the ultraviolet ray laser is not more than 243 nm such that the generation of active oxygen is promoted. Similarly, in one embodiment, the wavelength of ultraviolet rays emitted from the ultraviolet ray lamp or the ultraviolet ray LED is also not more than 243 nm such that the generation of active oxygen is promoted.
In this case, the irradiation dose of ultraviolet rays is adjusted such that the plating film 130 is deposited on the portion that has been modified by both the ultraviolet ray laser and the ultraviolet ray lamp or the ultraviolet ray LED in the plating step (step S230), which will be described later. On the other hand, the irradiation dose of ultraviolet rays is adjusted such that the plating film 130 is not deposited on the portion that is irradiated with only the ultraviolet ray lamp. Since the portion irradiated with the laser has already modified, this portion is modified such that the plating film 130 is deposited by weak modification treatment with irradiation of the ultraviolet rays emitted from the ultraviolet ray lamp, the ultraviolet ray LED, or the like for a short time period, for example. On the other hand, a portion that has not been irradiated with the laser is unlikely to be modified with weak modification treatment that is additionally performed, and thus the plating film 130 is not deposited. Therefore, even if modification treatment is performed evenly on the entire resin article 110, the plating film 130 can be selectively deposited on the modification portion 120 that is irradiated with the laser, in the plating step (step S230), which will be described later.
In order to prevent the surface of the resin article 110 from becoming rough, the irradiation intensity of the ultraviolet ray laser for irradiation is not more than 1.0×1015 W/cm2 in one embodiment. Also, in order to promote modification of the surface of the resin article 110, the irradiation intensity of the ultraviolet ray laser for irradiation is not less than 1.0×105 W/cm2 in one embodiment. Also, the irradiation intensity of the ultraviolet ray laser per pulse is not less than 10 mJ/cm2 in one embodiment, and not less than 10000 mJ/cm2 in one embodiment. For a similar purpose, the irradiation intensity of the ultraviolet rays from the ultraviolet ray lamp or the ultraviolet ray LED is not less than 0.1 mW/cm2 in one embodiment, not less than 0.3 mW/cm2 in another embodiment, and not less than 1.0 mW/cm2 in still another embodiment. On the other hand, the irradiation intensity is not more than 30 mW/cm2 in one embodiment, not more than 5.0 mW/cm2 in another embodiment, and not more than 3.0 mW/cm2 in still another embodiment.
The conditions under which the plating is deposited may change depending on the type of plating liquid, the type of resin article 110, the degree of contamination of the surface of the resin article 110, and the concentration, temperature, pH, and time-dependent degradation of the plating liquid, fluctuation in the output of the ultraviolet ray lamp, shifting in focus of the ultraviolet ray laser, and the like. Therefore, it is sufficient that the irradiation dose of ultraviolet rays is determined such that plating is selectively deposited on only the portion on which the plating film 130 is to be formed.
In another embodiment, after a portion of the surface of the resin article 110 is irradiated with the ultraviolet rays from an excimer lamp (first irradiation), a region including the portion of the surface of the resin article 110 is irradiated with ultraviolet rays from the ultraviolet ray lamp or the ultraviolet ray LED (second irradiation). For example, after the portion is irradiated with ultraviolet rays emitted from the excimer lamp via the photomask for a short time, a region including the portion that has been irradiated with ultraviolet rays emitted from the excimer lamp can be irradiated with ultraviolet rays emitted from the ultraviolet ray lamp or the ultraviolet ray LED without the photomask. In this manner, the surface of the resin article 110 can be modified such that the plating film 130 is deposited on the portion that has been irradiated with ultraviolet rays from the excimer lamp. The excimer lamp can modify the surface of the resin article 110 in a short time period, but has the property of inhibiting generation of some chemically-absorptive groups. Therefore, according to such an embodiment, a shift in the irradiation position of the ultraviolet rays can be suppressed, the shift being caused by a difference in thermal expansion coefficient between the photomask and the resin article 110. For example, in one embodiment, an Xe2 excimer lamp having a wavelength of 172 nm is used as the above-described excimer lamp, and a low pressure mercury vapor lamp having wavelengths of 185 nm and 254 nm is used as the above-described ultraviolet ray lamp.
There is no particular limitation on the resin article 110 used in the present embodiment as long as the surface is made of a resin material that is modifiable by ultraviolet rays. Examples of the resin material include polyolefin such as cycloolefin polymer or polystyrene, polyester such as polyethylene terephthalate, polyvinyl such as polyvinyl chloride, polycarbonate, and polyimide. If a resin material having a low alkali resistance, such as polycarbonate or polyimide, is used, performing alkali treatment may damage the material. Also, if a resin material having a low alkali resistance is used and alkali treatment is performed, there is a possibility that a portion that has not been irradiated with ultraviolet rays will also be damaged, and the plating film 130 will be deposited easily. On the other hand, because alkali treatment needs not to be performed in the present embodiment as described later, the present embodiment can also be applied to a resin material having a low alkali resistance, and the plating film 130 can be selectively deposited on a desirable portion.
There is no particular limitation on the shape of the resin article 110. For example, the resin article 110 may be film-like or plate-like. Furthermore, there is no particular limitation on the thickness of the resin article 110. Also, the resin article 110 needs not to be made of only a resin. That is, in one embodiment, the resin article 110 is a composite material having a covering structure obtained by the surface of another material being covered with a resin material. A specific example of the composite material is a composite material obtained by a surface of a metal material being covered with a resin material.
The resin article 110 has a smooth surface in one embodiment. A more uniform plating film 130 is formed by plating due to a smoother surface of the resin article 110. Usage of such a smooth plating film 130 as a lead wire makes it possible to suppress loss in a high frequency signal. According to a method for modifying the surface of the resin article 110 with ultraviolet rays as in the present embodiment, nanometer-order minute unevenness is formed on the surface of the resin article 110. In one embodiment, the surface roughness of the modification portion 120 immediately before electroless plating is performed is not more than 10 nm. Also, in the resin article with plating film 100 according to one embodiment, the surface roughness of the surface of the resin article 110 on the interface between the resin article 110 and the plating film 130 is not more than 10 nm. Unevenness that is formed in this manner is expected to be much smaller than micrometer-order unevenness that is obtained by irradiating the surface of the resin article with a visible laser having a higher intensity or that is formed by treatment with chromic acid or the like, for example, and is expected to have high surface smoothness. In this specification, the surface roughness indicates an arithmetic average roughness Ra defined by JIS B 0601:2001.
Applying Step
As shown in
In order to facilitate deposition of the plating film, in some cases, alkali treatment and conditioning treatment are performed as pretreatment for electroless plating. However, as in the present embodiment, according to the method for applying the catalyst to the modification portion 120 while the shock 190 is applied, the plating film 130 is easily deposited on the modification portion 120, and thus it is not necessary to perform alkali treatment or conditioning treatment. Of course, in order to further facilitate deposition of the plating film 130, alkali treatment or conditioning treatment may be further performed before the applying step.
There is no particular limitation on the type of catalyst that is applied to the resin article 110. In one embodiment, the catalyst is applied to the resin article 110 by applying catalyst ions to the surface of the resin article 110 and reducing the catalyst ions. In this case, it is not necessary to continuously apply shock in the series of steps including application and reduction of catalyst ions, and shock can be applied in some of the series of steps. For example, when the catalyst ions are applied, shock can be applied to the resin article 110. On the other hand, instead of using the catalyst ions, a colloidal catalyst or the like can also be applied to the surface of the resin article 110.
Examples of the catalyst ions include a palladium complex such as an HCl-acidic palladium complex. Also, another example of the catalyst ion is a palladium complex in which at least a portion of its structure has positive charge. A solution containing palladium complex ions having positive charge in the solution is used in one embodiment such that adherence to the modification portion 120 is improved. An example of the palladium complex of which at least a portion has positive charge is a complex in which amine-based ligands are coordinately bonded. Also, another example of the palladium complex of which at least the portion has positive charge is a basic amino acid complex of palladium.
A specific example of the palladium complex in which at least a portion of its structure has positive charge is a palladium (II) basic amino acid complex included in an activator liquid (JCU Corporation, product name: ELFSEED ES-300). Another example is a basic amino acid complex of palladium described in WO 2007/066460.
In one embodiment in which conditioning treatment is not performed, in order to facilitate deposition of the plating film 130, a palladium complex that partially has positive charge is used as the catalyst. The palladium complex that partially has positive charge easily attaches to the modification portion 120 even in the case where the conditioning treatment is not performed. Also, a binder that is contained in a conditioner liquid is likely to remain on a portion that is not irradiated with ultraviolet rays, and thus if the conditioning treatment is performed, a plating film is deposited on an unintended portion in some cases. Thus, omission of the conditioning treatment makes it easy to selectively deposit the plating film 130.
There is no particular limitation on the type of shock applied to the resin article 110 as long as the plating film 130 is deposited easily. In one embodiment, physical shock is applied as the shock. An example of the physical shock is mechanical shock. Examples of the mechanical shock include applying pressure waves against the resin article 110 and bringing a shock applying object into contact with the resin article 110. Examples of the shock applying object include bubbles and a shock applying member. Hereinafter, these types of shock will be described in detail.
Direct shock is applied to the modification portion 120 in one embodiment. However, if the plating film 130 is easily deposited on the modification portion 120, direct shock may be applied to a portion other than the modification portion 120 so as to also apply shock to the modification portion 120 via the resin article 110.
In one embodiment, pressure wave treatment for applying pressure waves against the resin article 110 is performed. For example, applying pressure waves to the resin article 110 in a catalyst ion solution makes it possible to apply the catalyst to the surface of the resin article 110. An example of the pressure waves is a sound wave. In one embodiment, in order to facilitate deposition of the plating film 130, ultrasonic wave treatment for irradiating the resin article 110 with ultrasonic waves is performed. The resin article 110 in any medium can be irradiated with the pressure waves. For example, the resin article 110 in water or in an aqueous solution can be irradiated with the ultrasonic waves using an ultrasonic wave emission device.
There is no particular limitation on the irradiation time of the pressure waves as long as the plating film 130 is deposited easily. The irradiation time of the pressure waves is not less than 5 minutes in one embodiment such that the plating film 130 is deposited easily. Also, the irradiation time of the pressure waves is not less than 10 minutes in one embodiment such that the adherence between the plating film 130 and the resin article 110 is improved. There is no particular upper limit of the irradiation time, and the irradiation time may be not more than 60 minutes, not more than 30 minutes, or not more than 20 minutes, for example.
In one embodiment, bubble treatment for bringing bubbles into contact with the resin article 110 is performed. For example, bringing bubbles into contact with the resin article 110 in a catalyst ion solution makes it possible to apply the catalyst to the surface of the resin article 110. Although there is no particular limitation on the type of bubbles, microbubble treatment in which microbubbles are used is used to perform uniform treatment in one embodiment. Because the microbubbles have characteristics of generating shock waves when they collapse, it is expected that a large shock can be applied with the microbubble treatment. The microbubbles indicate bubbles having a diameter of about 1 μm or more and 1000 μm or less. In order to perform uniform treatment, the diameter of the microbubbles is not more than 300 μm in one embodiment, and not more than 100 μm in another embodiment. On the other hand, in order to improve the treatment efficiency with a large shock, the diameter of the microbubbles is not less than 3 μm in one embodiment, and not less than 10 μm in another embodiment.
Bubbles can be generated using a regular bubble generator. For example, the microbubbles can be generated using a regular microbubble generator. The bubble treatment can be performed in a liquid using a bubble generator whose position is adjusted such that bubbles hit the resin article 110 that is immersed in the liquid. There is no particular limitation on the type of liquid, and water or an aqueous solution may be used, for example. There is no particular limitation on the bubbles, and air, oxygen, or nitrogen can be used, for example. Also, bubbles of ozone can also be used, expecting that the portion that has been irradiated with ultraviolet rays is further modified.
Nanobubbles, which are bubbles smaller than the microbubbles, can also be used as the bubbles. Because the nanobubbles also have characteristics of generating shock waves when they collapse, it is expected that a large shock can be applied with the nanobubble treatment. The nanobubbles indicate bubbles having a diameter of about 1 nm or more and 1000 nm or less. The diameter is not more than 300 nm in one embodiment, and not more than 100 nm in another embodiment.
There is no particular limitation on the time for bubble treatment as long as the plating film 130 is deposited easily. The time for bubble treatment is not less than 0.5 minutes in one embodiment such that the plating film 130 is deposited easily. Also, the time for bubble treatment is not less than 1 minute in one embodiment, and not less than 2 minutes in another embodiment, such that the adherence between the plating film 130 and the resin article 110 is improved. There is no particular limitation on the time for bubble treatment, and the time may be not more than 60 minutes, for example.
In one embodiment, a shock applying member is brought into contact with the resin article 110. Shock is applied to the portion that has been irradiated with ultraviolet rays due to contact with the shock applying member. For example, a frictional force can be applied to the portion of the resin article 110 that has been irradiated with ultraviolet rays by the modification portion 120 of the resin article 110 being rubbed using the shock applying member. Also, a compressive force can be applied to the portion of the resin article 110 that has been irradiated with ultraviolet rays by projecting the shock applying member against the modification portion 120 of the resin article 110. A specific example of one embodiment is brushing for rubbing the modification portion 120 with a brush.
For example, the catalyst can be applied to the surface of the resin article 110 by rubbing the resin article 110 with a brush in a catalyst ion solution or rubbing the resin article 110 moistened with the catalyst ion solution with a brush.
As described above, applying the catalyst to the surface of the resin article 110 can be performed by bringing the catalyst ion solution into contact with the resin article 110 while applying the shock 190 to the resin article 110.
If the catalyst ions are applied to the surface of the resin article 110, applying the catalyst to the surface of the resin article 110 is completed by reducing the catalyst ions. There is no particular limitation on a method for reducing the catalyst ions, and a reducing agent such as hydrogen gas, dimethylamine borane, or sodium borohydride can be used. As a specific method, the catalyst ions can be reduced and deposited by immersing the resin article 110 in a solution containing a reducing agent. A specific example of the reducing agent is a cationic detergent such as an accelerator liquid (JCU Corporation, product name: ELFSEED ES-400). It is not essential to apply shock to the resin article 110 when the catalyst ions are reduced.
Plating Step
In the plating step (step S230), electroless plating is performed on the resin article 110 to which the catalyst has been applied. As a result, as shown in
In one embodiment, the plating film 130 is formed with an electroless plating method. There is no particular limitation on a specific electroless plating method. Examples of the electroless plating method that can be adopted include an electroless plating method in which a formalin-based electroless plating bath is used, and an electroless plating method in which hypophosphorous acid, which has a slow deposition speed but can be easily handled, is used as the reducing agent. Specific examples of the electroless plating method include electroless nickel plating, electroless copper plating, electroless copper/nickel plating, zinc oxide electroless plating, or the like. The plating film 130 that is to be formed is a metal film in one embodiment, and may be a ceramic film such as a zinc oxide plating film. The adherence between the modification portion 120 and the deposited plating film 130 is improved by modifying the resin article 110 as described above.
The electroless plating can be performed using an electroless plating liquid set such as Cu—Ni plating liquid set “AISL” produced by JCU Corporation, for example.
In another embodiment, the plating film 130 may be formed with a high-speed electroless plating method. According to the high-speed electroless plating method, a thicker plating film can be formed. In still another embodiment, plating is deposited with an electrolytic plating method on the plating film 130 that has been formed with electroless plating. According to this method, a much thicker plating film 130 can be formed. There is no particular limitation on a specific electrolytic plating method.
There is no particular limitation on the thickness of the obtaining plating film 130. The plating film 130 having an appropriate thickness is formed in accordance with a usage of the resin article with plating film 100 that is to be obtained.
The resin article with plating film 100 that has been obtained in this manner includes the resin article 110 having the modification portion 120 that has been modified by irradiation of the ultraviolet rays and application of shock, and the plating film 130 that has been formed on the modification portion 120. The resin article with plating film 100 that has been obtained in this manner can be used as various applications such as a circuit board, a conductive film, a UV-cutting material, and a photocatalyst.
In the present embodiment in which a step of applying a catalyst while applying shock is used, alkali treatment in which alkali is used, and conditioning treatment in which a conditioner liquid containing a binder for a resin article and a catalyst is used are not required. Thus, the resin article with plating film 100 can be produced with a simpler method. Also, the present embodiment in which alkali treatment is not required can also be applied to the resin article 110 having a low alkali resistance. In one embodiment, alkali treatment in which an alkali liquid having a pH of 13 or more is used is not performed from the irradiating step (step S210) to the plating step (step S230), that is, from when the modification portion 120 is formed by irradiation of the ultraviolet rays to when the plating film 130 is formed. In another embodiment, alkali treatment is not performed from when the modification portion 120 is formed by irradiation of the ultraviolet rays to when the plating film 130 is formed.
EXAMPLES Example 1A cycloolefin polymer material (produced by Zeon Corporation, ZeonorFilm ZF-16, film thickness 100 μm, surface roughness Ra=0.47 nm), which is the resin material, was used as a substrate.
First, before the surface was modified, the substrate was subjected to ultrasonic wave cleaning with pure water at 50° C. for 3 minutes for the purpose of cleaning the substrate surface, and then the substrate was dried.
Next, a portion of the substrate was irradiated with ultraviolet rays that were emitted from an ultraviolet ray lamp via a quartz/chromium mask that was placed on the substrate in an air atmosphere. The details of the ultraviolet ray lamp (low pressure mercury vapor lamp) that was used in this example are described below. A surface roughness Ra of the substrate after being irradiated with ultraviolet rays was 0.26 nm.
Low pressure mercury vapor lamp: UV-300 (dominant wavelength 185 nm, 254 nm) produced by Samco Inc.:
Irradiation distance: 3.5 cm
Irradiation time: 15 minutes
Luminous intensity at an irradiation distance of 3.5 cm: 5.40 mW/cm2 (254 nm)
-
- 1.35 mW/cm2 (185 nm)
Next, catalyst applying treatment was performed on the substrate while ultrasonic wave treatment was performed on the substrate that had been irradiated with ultraviolet rays. Specifically, the catalyst applying treatment was performed for 10 minutes on the substrate in an activator liquid (JCU Corporation, product name ELFSEED ES-300) that had been heated to 50° C., using an ultrasonic wave cleaning device (produced by Sharp Corporation, UT-206H, frequency 37 kHz, output 100%). Thereafter, the substrate was cleaned in pure water.
Next, reduction treatment was performed on the substrate. Specifically, an accelerator liquid (JCU Corporation, product name ELFSEED ES-400) was heated to 50° C. and the substrate was immersed in the heated accelerator liquid for 2 minutes. Thereafter, the substrate was cleaned in pure water.
Next, electroless copper-nickel plating was performed on the substrate. Specifically, an electroless Cu—Ni plating liquid that is used in the plating liquid set “AISL” produced by JCU Corporation was heated to 60° C. and the substrate was immersed in the heated plating liquid for 5 minutes. Thereafter, the substrate was cleaned in pure water and dried. In this manner, the resin article with plating film was produced.
When the obtained resin article with plating film was observed, the plating film was evenly deposited on portions that were irradiated with ultraviolet rays, and the plating film was not deposited on portions that were not irradiated with ultraviolet rays.
Example 2A resin article with a plating film was produced similarly to Example 1 except that the catalyst applying processing was performed for 20 minutes in Example 2. When the obtained resin article with the plating film was observed, the plating film was evenly deposited on portions that were irradiated with ultraviolet rays, and the plating film was not deposited on portions that were not irradiated with ultraviolet rays.
Comparative Examples 1 and 2Resin articles with plating films were produced similarly to Examples 1 and 2 except that ultrasonic wave treatment was not performed when the catalyst applying treatment was performed in Comparative Examples 1 and 2. When the obtained resin articles with plating films were observed, the plating film was deposited on the circumferential edge portions of regions that were irradiated with ultraviolet rays in all resin articles, but the plating film was not deposited on a central portion of the region that was irradiated with ultraviolet rays.
According to the results of the examples and the comparative examples, it was confirmed that performing the catalyst applying treatment while applying shock makes it possible to sufficiently deposit plating on portions that were irradiated with ultraviolet rays.
Regarding the resin articles with plating films that were produced in Examples 1 and 2, the adherence of the plating films to the substrates was evaluated. A tape testing method conforming to JIS H 8504:1996 was used to evaluate the adherence. When tape was attached to and peeled off from the resin articles with plating films that were produced in Examples 1 and 2, separation of the plating films was not observed. In this manner, it was confirmed that performing the catalysts applying treatment while performing the ultrasonic wave treatment makes it possible to sufficiently deposit plating on the portions that were irradiated with ultraviolet rays, and that the adherence of the plating film to the substrate is favorable.
From the above-described results, it was found that performing the catalyst applying treatment while applying shock allows the plating film to be uniformly deposited on the resin article even if alkali treatment and conditioning treatment are omitted, and the adherence of the plating film to the resin article is favorable. On the other hand, it was confirmed that in the case where shock is not applied, if alkali treatment and conditioning treatment are not performed, plating is not favorably deposited. It was confirmed that plating is easily deposited by applying a catalyst while applying shock.
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. 2015-239739, filed Dec. 8, 2015, which is hereby incorporated by reference herein in its entirety.
Claims
1. A method for manufacturing a resin article provided with a plating film, comprising:
- irradiating the resin article with ultraviolet rays;
- applying a catalyst to the resin article while applying shock to the resin article that has been irradiated with the ultraviolet rays; and
- performing electroless plating on the resin article.
2. The method for manufacturing a resin article according to claim 1, wherein
- the shock is bubbles and/or pressure waves.
3. The method for manufacturing a resin article according to claim 2, wherein
- the shock is microbubbles or ultrasonic waves.
4. The method for manufacturing a resin article according to claim 1, wherein
- the applying includes:
- applying shock to the resin article in a catalyst ion solution; and
- reducing catalyst ions applied to the resin article to an electroless plating catalyst.
5. The method for manufacturing a resin article according to claim 1, wherein
- in the irradiating, the resin article is irradiated with the ultraviolet rays in an atmosphere including oxygen and/or ozone.
6. The method for manufacturing a resin article according to claim 1, wherein
- a dominant wavelength of the ultraviolet rays is not more than 243 nm.
7. The method for manufacturing a resin article according to claim 1, wherein
- in the irradiating, a portion of a surface of the resin article is irradiated with ultraviolet rays, and plating is selectively deposited on the portion of the surface of the resin article.
8. The method for manufacturing a resin article according to claim 1, wherein
- the irradiating includes:
- irradiating a portion of a surface of the resin article with an ultraviolet ray laser; and
- irradiating a region including the portion of the surface of the resin article with ultraviolet rays from an ultraviolet ray lamp or an ultraviolet ray LED, and
- plating is selectively deposited on the portion of the surface of the resin article.
9. The method for manufacturing a resin article according to claim 4, wherein
- the catalyst ions are palladium complexes of which at least a portion has positive charge.
10. A resin article with a plating film manufactured according to the method comprising:
- irradiating the resin article with ultraviolet rays;
- applying a catalyst to the resin article while applying shock to the resin article that has been irradiated with the ultraviolet rays; and
- performing electroless plating on the resin article.
11. A method for manufacturing a resin article, comprising:
- irradiating the resin article with ultraviolet rays; and
- applying, after the irradiating, the catalyst to a surface of the resin article such that a plating film is deposited, while applying bubbles and/or pressure waves against the resin article.
Type: Application
Filed: Nov 16, 2016
Publication Date: Jun 8, 2017
Inventor: Taisuke IWASHITA (Kodama-gun)
Application Number: 15/353,200
