JP6590309B2 - Plastic substrate with conductive layer and manufacturing method thereof - Google Patents

Description

  The present invention relates to a plastic substrate with a conductive layer and a method for manufacturing the same. In particular, the present invention relates to a plastic substrate using polyethylene naphthalate resin (PEN), polyimide resin (PI), or cycloolefin polymer resin (COP).

  Even today, the manufacturing of printed circuit boards in industrialized countries is faced with a tough fight due to international price competition. Therefore, a cheaper method for manufacturing a wiring board has been studied without always degrading the quality.

  Among them, the applicants related to the present invention have proposed a method of forming a conductor layer by an electroless method by irradiating ultraviolet rays (UV) onto the surface of a substrate constituting an insulating layer of a wiring board. For example, as disclosed in Patent Document 1, a surface modification method using a cycloolefin polymer material having excellent dielectric properties and forming a metal film with good adhesion, and a cycloolefin polymer with a metal film In order to provide a material, “cycloolefin polymer material is irradiated with ultraviolet rays in an aerobic atmosphere, and C—H group constituting the cycloolefin polymer material is changed to —OH group and / or —C═O group. In addition, the surface of the surface thus modified is subjected to electroplating with the electroless plating having a slow deposition rate as a base, thereby providing good adhesion at a predetermined thickness. A cycloolefin polymer material with a metal coating can be obtained. "

  In addition, Patent Document 2 aims to provide a metal-clad laminate with improved adhesion between a liquid crystal polymer film and a conductor layer, and “a liquid crystal polymer film with a metal layer on the surface of a liquid crystal polymer film substrate”. A liquid crystal, wherein the metal layer is an electroless metal plating layer formed by an electroless method on the surface of a liquid crystal polymer film substrate having a surface roughness (Rzjis) of 1.0 μm or less. A polymer film metal-clad laminate is adopted.In particular, the liquid crystal polymer film substrate preferably uses a surface modified by UV irradiation before the formation of the electroless metal plating layer. is doing.

  Furthermore, in Patent Document 3, the production of a resin material with a metal pattern that can satisfy the dimensional accuracy required for a resin material and can form a fine metal pattern with good adhesion on the resin material. For the purpose of providing a method and a resin material with a metal pattern, “a step of forming a metal pattern on the surface of a substrate for pattern formation by an electroless plating method, and a liquid resin composition on the substrate Forming a resin composition film using, solidifying or curing the resin layer to obtain a resin layer in close contact with the metal pattern, and separating the resin layer and the substrate to obtain a resin material with a metal pattern The manufacturing method of the resin material with a metal pattern characterized by including the above-mentioned ", and also in this case, as the surface modification treatment before applying the catalyst, ultraviolet rays are used so that the patterning can be performed with high accuracy. It discloses adopting irradiation treatment.

JP 2008-94923 A Japanese Patent Laid-Open No. 2008-212488 Japanese Patent Laying-Open No. 2015-59244

  However, it has been pointed out that even if the plating layer formed by the electroless plating disclosed in the above-mentioned prior art documents has excellent film thickness uniformity, the adhesion to the plastic substrate may vary. . In recent years, a plastic substrate with a gold layer in which a gold layer is formed on the surface of the plastic substrate is required, and its use in various fields such as electronic component materials and medical devices is considered.

  Therefore, an object of the present invention is to provide a plastic substrate with a gold layer in which a gold layer having excellent film thickness uniformity and adhesion is formed on the surface of the plastic substrate, and a method for manufacturing the same.

  Accordingly, the inventors have intensively studied to arrive at the solution of the above problems by the means described below.

Plastic substrate with gold layer: The plastic substrate with gold layer according to the present application is a plastic substrate with a gold layer having a gold layer on the surface of the plastic substrate, and the gold layer is a water-soluble gold salt-containing solution. It is characterized by comprising a gold nanoparticle layer obtained by using gold nanoparticles obtained by reduction precipitation using a solution plasma reaction, and an electroless gold plating layer.

  In the plastic base material with a gold layer according to the present application, the gold nanoparticles constituting the gold nanoparticle layer preferably have an average particle diameter of 1 nm to 50 nm.

  It is preferable that the plastic base material used in the plastic base material with a gold layer according to the present application includes any resin component of polyethylene naphthalate resin, polyimide resin, and cycloolefin polymer resin.

Manufacturing method of plastic substrate with gold layer according to the present application: The manufacturing method of the plastic substrate with gold layer according to the present application includes the following steps a to c.

Step a: The surface of the plastic substrate on which the gold layer is to be formed is treated with an alkali solution, or an alkali solution treatment and an ultraviolet irradiation treatment are combined to obtain a surface-modified plastic substrate.
Step b: Modified surface of the surface-modified plastic substrate, and a gold nanoparticle-containing slurry containing gold nanoparticles obtained by reduction precipitation using a solution plasma reaction in a water-soluble gold salt-containing solution, Are contacted, gold nanoparticles are adhered to the modified surface of the surface-modified plastic substrate to form a gold nanoparticle layer, and a plastic substrate with a gold nanoparticle layer is obtained.
Step c: An electroless gold plating layer is provided on the gold nanoparticle layer of the plastic substrate with a gold nanoparticle layer to obtain a plastic substrate with a gold layer.

  It is preferable to use what added the alcohol component in the range of 8 vol%-15 vol% as the said water-soluble gold salt containing solution used with the manufacturing method of the plastic base material with a gold layer which concerns on this application.

The gold nanoparticle-containing slurry used in the method for producing a plastic substrate with a gold layer according to the present application uses an aqueous solution containing a water-soluble gold salt at a concentration of 0.03 mM to 0.1 mM as a solvent. An intermediate plasma is generated, and gold ions having an average particle diameter of 1 nm to 50 nm are generated by reducing dissolved gold ions, and the gold nanoparticles are prepared so as to contain 0.01 vol% to 2 vol%. It is characterized by using.

  The plastic substrate with a gold layer according to the present application is obtained without using a palladium chloride catalyst that has been used in the conventional electroless gold plating method, and the gold layer is a "gold nanoparticle layer", It consists of “electroless gold plating layer”. At this time, the adhesion between the electroless gold plating layer and the plastic substrate is very high. As a result, even if a copper layer is formed on the surface of the electroless gold plating layer and a circuit is further formed, a product having good adhesion to the plastic substrate can be obtained.

  In addition, the method for producing a plastic substrate with a gold layer according to the present application uses a solution plasma reaction in a solution containing a water-soluble gold salt in advance on the surface of a plastic substrate subjected to chemical fine roughening by alkali treatment or the like. In order to attach gold nanoparticles obtained by reduction deposition and then apply autocatalytic electroless gold plating, the gold nanoparticles contribute as a fine anchor of the gold layer, and the gold layer on the plastic substrate High adhesion can be achieved.

It is an image figure of an in-liquid plasma generator.

  Hereinafter, the “form of the plastic substrate with a gold layer” and the “production form of the plastic substrate with a gold layer” according to the present application will be described.

A. Form of plastic substrate with gold layer The plastic substrate with a gold layer according to the present application comprises a gold layer on the surface of the plastic substrate. The gold layer includes a gold nanoparticle layer obtained by using gold nanoparticles obtained by reduction deposition using a solution plasma reaction in a water-soluble gold salt-containing solution, an electroless gold plating layer, It is characterized by comprising.

Plastic base material: The plastic base material referred to in the present application refers to a material containing any resin component of polyethylene naphthalate resin, polyimide resin, and cycloolefin polymer resin. These resins are chemically and thermally stable, and are expected to be used as electronic component materials and biocompatible materials, and have been said to be difficult to obtain adhesion to the plating layer. is there. In this case, the “plastic substrate” is not limited in thickness, size, shape, etc., and is not limited to a planar shape like a simple film, but may be a three-dimensional shape.

Gold nanoparticle layer: The gold nanoparticle layer referred to in the present application preferably has an average particle diameter of 1 nm to 50 nm. Although described in the form of a manufacturing method described below, the surface of the plastic substrate is used after being finely roughened by etching, plasma treatment, ultraviolet irradiation treatment, alkali treatment, or the like. It is preferable that the gold nanoparticles enter and be fixedly attached to the concave portions of the fine irregularities formed by this fine roughening. Therefore, if the average particle diameter exceeds 50 nm, it becomes difficult for gold nanoparticles to enter the concave portions of the fine irregularities on the surface of the plastic substrate, and thus it is not possible to improve the adhesion between the gold layer and the plastic substrate. On the other hand, although the lower limit of the average particle diameter is 1 nm here, it is not intended to exclude the range of less than 1 nm. Since direct observation by high-magnification observation such as a transmission electron microscope becomes difficult, only a temporary lower limit is shown. The average particle size in this application is “W. Haiss, NTK Thanh, J. Aveard, and D. G. Fernig (2007) Determination of size and concentration of nanoparticulate UV. Anal. Chem, 79, 4215-4221 "was calculated using an empirical formula disclosed in" Anal.

Electroless gold plating layer: The electroless gold plating layer referred to in the present application is formed of an autocatalytic electroless gold plating solution using the above-described gold nanoparticle layer instead of a catalyst. The electroless gold plating layer at this time is not particularly limited in thickness, impurities contained therein, and the like. However, considering the economy, the thickness is preferably in the range of 0.1 μm to 2.0 μm. If the thickness of the electroless gold plating layer is less than 0.1 μm, the surface of the plastic substrate may not be uniformly coated, which is not preferable because the film thickness tends to be poor. On the other hand, when the thickness of the electroless gold plating layer exceeds 2.0 μm, the color tone of the electroless gold plating layer tends to vary, and the cost increases.

  The plastic substrate with a gold layer according to the present application described above is used as a biocompatible material as it is or for producing an electronic component material by providing a copper plating layer on the surface of an electroless gold plating layer. It becomes the basic material.

Production form of plastic substrate with gold layer: The method for producing a plastic substrate with gold layer comprises the following steps a to c. Hereinafter, each step will be described.

Step a: In this step, the surface of the plastic substrate on which the gold layer is formed is treated with an alkali solution, or a surface-modified plastic substrate is obtained by combining the alkali solution treatment and the ultraviolet irradiation treatment.

  The “alkaline solution treatment” used herein is treatment using an alkaline solution having an alkali component concentration of 8 wt% or more such as sodium hydroxide and potassium hydroxide and a liquid temperature of 45 ° C. to 55 ° C. This is because if the alkali component concentration of the alkaline solution at this time is less than 8 wt%, it is difficult to modify the surface of the plastic substrate and form fine irregularities even after long-time treatment.

In addition, before and after the alkaline solution treatment similar to that described above, it is also preferable that the surface of the plastic substrate is subjected to ultraviolet irradiation treatment to perform surface modification treatment to form fine irregularities. This is because by performing ultraviolet irradiation, the contact angle with water on the surface of the plastic substrate is small, and the wettability is improved. For the surface modification by the ultraviolet irradiation treatment in the present application, a UV exposure apparatus (KOL1-300 manufactured by Koto Electric Co., Ltd.) is used. Looking at the irradiation amount in the wavelength region of 154 nm of this apparatus, when the irradiation amount is about 300 mJ / cm ² , the contact angle of water is in the range of 50 ° to 60 °, and the wettability is improved when the irradiation amount is around 900 mJ / cm ^2. The effect seems to saturate. This is because the roughness of the surface of the plastic substrate increases as the irradiation amount of ultraviolet rays increases as seen from the surface of the plastic substrate before irradiation with ultraviolet rays (irradiation amount is 0 mJ / cm ² : Rz = 4.7 nm). It can be understood from the fact that the amount is 300 mJ / cm ² : Rz = 4.7 nm). In addition, the surface roughness of the plastic substrate at this time was measured with an atomic force microscope (Hitachi High-Tech Science Co., Ltd., SPI-3800N).

Step b: In this step, gold nano-particles containing gold nanoparticles obtained by reduction precipitation using a solution plasma reaction in a water-soluble gold salt-containing solution and a modified surface of the surface-modified plastic base material The particle-containing slurry is brought into contact, and gold nanoparticles are adhered to the modified surface of the surface-modified plastic substrate to form a gold nanoparticle layer, thereby obtaining a plastic substrate with a gold nanoparticle layer.

  The gold nanoparticle-containing slurry is prepared as follows. A submerged plasma generator 1 as shown in FIG. 1 was used. This submerged plasma generator 1 includes a pulse power source 3 and a rectifier 2. When a voltage is applied from the rectifier 2 to a tungsten electrode 4 disposed in a solution tank 5 containing a water-soluble gold salt-containing solution 6, The surroundings are heated to a boiling state, bubbles are generated, dielectric breakdown occurs in the bubbles, and plasma is generated in the bubbles to form continuous plasma. In addition, in the in-liquid plasma generator 1, the solution tank 5 is accommodated in the water-cooled tank 8, and includes a magnetic stirrer device 7 and a stirrer 9.

  The water-soluble gold salt-containing solution to be placed in the solution tank of the in-liquid plasma generator contains sodium gold sulfite, sodium gold cyanide, potassium gold cyanide, sodium chloroaurate, potassium chloroaurate, etc. Although it is an aqueous solution, all the water-soluble gold salts which can be used as a gold supply source can be used. The water-soluble gold salt concentration is preferably 0.03 mM to 0.1 mM. When the water-soluble gold salt concentration is less than 0.03 mM, the reduction precipitation rate of the gold nanoparticles is slow, and the gold nanoparticle content contained in the gold nanoparticle-containing slurry is also lowered, which is undesirable in the present application. On the other hand, when the concentration of the water-soluble gold salt is too high, the gold nanoparticle content contained in the gold nanoparticle-containing slurry becomes excessive. There is a tendency that the penetration of particles becomes difficult, which is not preferable.

  Further, the water-soluble gold salt-containing solution preferably contains an alcohol component in the range of 8 vol% to 15 vol%. It is because it becomes easy to control the particle size of the obtained gold nanoparticles to 10 nm or less by containing the alcohol component. When the alcohol component contained in the gold nanoparticle-containing slurry is less than 8 vol%, it is difficult to reduce the particle size of the gold nanoparticle. On the other hand, even if the alcohol component contained in the gold nanoparticle-containing slurry exceeds 15 vol%, the effect of refining the particle size of the gold nanoparticle is saturated, which is not preferable because it is merely a waste of resources.

  In the water-soluble gold salt-containing solution described above, plasma in the liquid is generated, and dissolved gold ions are reduced to generate gold nanoparticles having an average particle diameter of 1 nm to 50 nm. A gold nanoparticle-containing slurry can be obtained by adding 0.01 vol% to 2 vol%. Note that the conditions for generating the plasma in liquid at this time are not particularly limited as long as the plasma generation state can be maintained in the liquid. For example, the frequency of the power source is 20 kHz, the pulse width is 0.8 μm, 1.2 μm, and the secondary voltage is 1.5 to 2.0 kV.

  The gold nanoparticle layer is obtained by bringing the gold nanoparticle-containing slurry described above into contact with the modified surface of the surface-modified plastic substrate, and attaching the gold nanoparticles to the modified surface of the surface-modified plastic substrate. To obtain a plastic substrate with a gold nanoparticle layer. The contact between the gold nanoparticle-containing slurry and the modified surface of the surface-modified plastic substrate is performed by immersing the surface-modified plastic substrate in the gold nanoparticle-containing slurry. It is only necessary that the gold nanoparticles can be attached to the modified surface of the surface-modified plastic substrate, such as a method of spraying the gold nanoparticle-containing slurry.

Step c: In this step, an electroless gold plating layer is provided on the gold nanoparticle layer of the plastic substrate with a gold nanoparticle layer to obtain a plastic substrate with a gold layer. At this time, any known electrocatalytic electroless gold plating bath can be used. Hereinafter, examples and comparative examples will be described.

  In Example 1, a polyethylene naphthalate resin film was used as a plastic substrate, and a gold layer was formed on the surface by the process shown in Table 1 to obtain a polyethylene naphthalate resin substrate with a gold layer. The evaluation of a plurality of polyethylene naphthalate resin films with a gold layer obtained by changing the conditions in this process is summarized in Table 3 below.

For “electroless gold plating” in Table 1, an autocatalytic electroless gold plating bath having the composition shown in Table 2 below was employed.

  And when the gold nanoparticle containing slurry used for catalyst provision of Example 1 obtains a gold nanoparticle diameter 5nm, sodium chloroaurate aqueous solution (0.05mM), ethanol as a water-soluble gold salt containing solution (10 vol%) was used. And when obtaining a thing with a gold nanoparticle diameter of 75 nm and 90 nm, the sodium chloroaurate aqueous solution (0.05 mM) was used. Gold nanoparticles were formed by reducing gold ions using plasma in liquid. MPP-HV04 manufactured by Kurita Seisakusho is used for the pulse power supply, and the power supply conditions are a frequency of 20 kHz, a pulse width of 0.8 μm or 1.2 μm, a secondary voltage of 1.5 kV to 2.0 kV, and peak absorption at UV / Vis. Gold nanoparticle-containing slurries with zones different from 522 nm, 540 nm, and 560 nm were prepared. The synthetic particle size estimated from the peak absorption band and the empirical formula of Haiss was 50 nm to 150 nm, respectively.

  This Example 2 is different only in that the polyethylene naphthalate resin film, which is a plastic substrate used in Example 1, is changed to a polyimide resin film. The evaluation of the polyimide resin films with a plurality of gold layers obtained here is summarized in Table 3 below.

  Example 2 differs from Example 2 only in that the polyethylene naphthalate resin film, which is a plastic substrate used in Example 1, is changed to a cycloolefin polymer resin film. The evaluation of the obtained cycloolefin polymer resin films with a gold layer is summarized in Table 3 below.

Comparative example

  This comparative example differs in the catalyst application process of Example 1. In Example 1, the adhesion of gold nanoparticles can be regarded as catalysis, but in the comparative example, a conventional palladium catalyst was used. Catalysis with palladium at this time was performed by performing a washing step of immersing in NNP Axela (Okuno Pharmaceutical Co., Ltd.), which is a commercially available palladium catalyst solution, for 1 minute, and then immersing in pure water for 1 minute. And the electroless gold plating similar to Example 1 was performed, and the evaluation of the several polyethylene naphthalate resin film with a gold layer obtained here is put together in the following Table 3, and is shown.

[Evaluation results]
Table 3 below shows the evaluation results of the examples and comparative examples. Hereinafter, a description will be given with reference to Table 3.

  Table 3 shows the following. Comparing the examples with the comparative examples, the appearance of the gold layer such as a polyethylene naphthalate resin film with a gold layer is more advantageous than the comparative example using a conventional palladium catalyst. However, in all of Comparative Samples 1 to 8, peeling due to the tape in the cross-cut test occurs. On the other hand, in all of the implementation samples, the tape peeling cannot be confirmed, and it can be seen that good adhesion to the plastic substrate can be secured.

  Furthermore, when the inside of an Example is seen, it turns out that the external appearance of gold layers, such as a polyethylene naphthalate resin film with a gold layer, becomes beautiful, so that the particle size of the gold nanoparticle used as a catalyst in each Example is small.

 The gold layer of the plastic substrate with a gold layer according to the present application has few impurity components and has very high adhesion between the electroless gold plating layer and the plastic substrate. Therefore, it can be used in various fields such as electronic component materials and medical equipment. In addition, the method for producing a plastic substrate with a gold layer according to the present application includes a “solution in a water-soluble gold salt-containing solution that contributes in advance to the surface of a plastic substrate that has been subjected to chemical fine roughening by alkali treatment or the like. Since gold nanoparticles obtained by reduction deposition using a plasma reaction are adhered, and then autocatalytic electroless gold plating is performed, a gold layer containing a small amount of different components can be obtained.

DESCRIPTION OF SYMBOLS 1 Submerged plasma generator 2 Rectifier 3 Pulse power supply 4 Tungsten electrode 5 Solution tank 6 Water-soluble gold salt containing solution
7 Magnetic stirrer 8 Water cooling tank 9 Stir bar

Claims (6)

A plastic substrate with a gold layer comprising a gold layer on the surface of the plastic substrate,
The gold layer comprises a gold nanoparticle layer obtained by using gold nanoparticles obtained by reduction deposition using a solution plasma reaction in a water-soluble gold salt-containing solution, and an electroless gold plating layer. A plastic base material with a gold layer. 2. The plastic substrate with a gold layer according to claim 1, wherein the gold nanoparticles constituting the gold nanoparticle layer have an average particle diameter of 1 nm to 50 nm. The plastic substrate with a gold layer according to claim 1 or 2, wherein the plastic substrate contains a resin component of any one of polyethylene naphthalate resin, polyimide resin, and cycloolefin polymer resin. A method for producing a plastic substrate with a gold layer comprising a gold layer on the surface of a plastic substrate, comprising the following steps a to c.
Step a: The surface of the plastic substrate on which the gold layer is to be formed is treated with an alkali solution, or an alkali solution treatment and an ultraviolet irradiation treatment are combined to obtain a surface-modified plastic substrate.
Step b: a modified surface of the surface-modified plastic substrate, and a gold nanoparticle-containing slurry containing gold nanoparticles obtained by reduction precipitation using a solution plasma reaction in a water-soluble gold salt-containing solution; Are contacted, gold nanoparticles are adhered to the modified surface of the surface-modified plastic substrate to form a gold nanoparticle layer, and a plastic substrate with a gold nanoparticle layer is obtained.
Step c: An electroless gold plating layer is provided on the gold nanoparticle layer of the plastic substrate with a gold nanoparticle layer to obtain a plastic substrate with a gold layer. The said water-soluble gold salt containing solution is a manufacturing method of the plastic base material with a gold layer of Claim 4 using what contains the alcohol component in the range of 8 vol%-15 vol%. As the gold nanoparticle-containing slurry, an aqueous solution containing a water-soluble gold salt at a concentration of 0.03 mM to 0.1 mM is used as a solvent, plasma is generated in the solvent in this solvent, and dissolved gold ions are reduced. The gold layered plastic according to claim 4 or 5, wherein gold nanoparticles having an average particle diameter of 1 nm to 50 nm are generated and prepared so that the gold nanoparticles are contained in an amount of 0.01 vol% to 2 vol%. A method for producing a substrate.

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