KR20150086811A - Method for metal plating on synthetic resin product - Google Patents

Abstract

Disclosed in the present invention is a plating method for a synthetic resin product, which forms various patterns on the surface of a synthetic resin product that does not contain heavy metal and forms a plating layer with excellent adhesion. The plating method comprises: a laser activating step which irradiates a laser beam to a plating area on the surface of a synthetic resin product in order to form fine pores on the surface; a catalyst adsorption accelerating step which immerses the synthetic resin product in an acceleration solution so that an adsorption accelerating material can be attached to the surface of the synthetic resin product for accelerating the adsorption of a metal catalyst; a metal catalyst adsorbing step which immerses the synthetic resin product in a metal catalyst solution so that the metal catalyst can be adsorbed to the surface of the synthetic resin product; an etching step which immerses the synthetic resin product in an etching solution in order to remove the adsorption accelerating material from the surface of the synthetic resin product and to remove the metal catalyst from the surface of the synthetic resin product except for the plating area; and an electroless plating step which performs electroless plating of metal in the plating area using the metal catalyst as a seed.

Description

TECHNICAL FIELD The present invention relates to a method for plating a synthetic resin product,

The present invention relates to a method for plating a metal layer with an intended pattern on the surface of a synthetic resin product.

In order to lighten and miniaturize electronic devices such as smart phones and tablet PCs and to reduce costs, injection molded synthetic resin products are widely used. Synthetic resin products are lightweight, have few limitations on the product shape by injection molding, and have a disadvantage in that it is difficult to apply them to parts requiring electrical conductivity because they are inexpensive but non-conductive. Accordingly, several methods for forming a metal layer capable of conducting electricity by processing a surface of a synthetic resin product are known. By applying this method, a wireless communication antenna is formed in a housing of a mobile electronic device such as a smart phone or a tablet PC.

An example of a method of forming a metal layer on the surface of a conventional synthetic resin product includes etching the surface of a synthetic resin product using an organic solvent, adsorbing the catalyst metal, and electroless plating. Another example of a method of forming a metal layer on the surface of a conventional synthetic resin product includes a step of exposing a heavy metal component to a surface of a synthetic resin product mixed with a heavy metal by laser etching, And is disclosed in Korean Registered Patent No. 10-0374667, Korean Patent Publication No. 10-2001-0040872, and Korean Patent Laid-Open No. 10-2004-0021614.

However, the above-mentioned method using the organic solvent has a risk of fire at the work site by using an organic solvent having a low boiling point, and there is a possibility of harming the health of workers due to the toxic substances contained in organic solvents having high volatility and environmental hormones have. Further, since the organic solvent rapidly dissolves the synthetic resin product, it is difficult to control the degree to which the surface of the product is etched, and it is difficult to form a uniform plating layer. On the other hand, a method using a synthetic resin product in which heavy metals are mixed requires the use of a special synthetic resin containing heavy metals, which increases the production cost.

Korean Patent Publication No. 10-0374667 Korean Patent Publication No. 10-2001-0040872 Korean Patent Publication No. 10-2004-0021614

The present invention provides a synthetic resin product plating method capable of forming a plating layer having excellent adhesion, which can be formed in various patterns on the surface of a synthetic resin product containing no heavy metal.

Also, the present invention provides a plating method of a synthetic resin product which can reduce the environmental pollution problem and the risk of fire accident because volatile organic solvent is not used.

The present invention relates to a method of manufacturing a synthetic resin product, which comprises: a laser activation step of irradiating a laser to a plating area on the surface of a synthetic resin product to form micropores on the surface; A metal catalyst adsorption step of immersing the synthetic resin product in the promoting solution so that the synthetic resin product is immersed in the metal catalyst solution to adsorb the synthetic resin product on the surface of the synthetic resin product; An etching step of removing the adsorption promoting material from the surface of the synthetic resin product and removing the metal catalyst from the surface of the synthetic resin product other than the plating area; A method of plating a synthetic resin product having an electroless plating step of electrolessly plating a metal in a region Provided.

The electroless plating step includes: 2.5 to 3 g / L of copper (Cu), 8 to 9 g / L of sodium hydroxide, 3 to 3.8 g / L of formazan and 30 to 35 g / L of ethylenediaminetetraacetic acid (EDTA) A primary copper layer plating step of immersing the synthetic resin product in a copper plating solution at a temperature of 55 to 65 DEG C for 5 to 10 minutes to form a primary copper layer, And a secondary copper layer plating step of immersing the synthetic resin product in the same copper plating solution at a temperature of 40 to 50 DEG C to form a secondary copper layer.

The electroless plating step may further include a protective layer plating step of plating a protective layer made of a nickel (Ni) alloy or a tin (Sn) alloy harder than copper (Cu) on the secondary copper layer have.

The promoting solution is a solution obtained by mixing 5 to 50 g of tin chloride (SnCl ₂ ) and 10 to 50 ml of 36% hydrochloric acid (HCl) per liter of water, and the catalyst adsorption promotion step is performed at 10 to 30 ° C And immersing the synthetic resin product in the promoting solution for 2 to 8 minutes.

The metal catalyst solution is prepared by mixing 0.1 to 0.4 g of palladium chloride and 10 to 50 ml of 36% hydrochloric acid per liter of water or 0.1 to 1 g of palladium sulfate and 1 to 100 ml of 98% May be mixed.

The etching solution is a solution obtained by mixing 50 to 100 g of ammonium fluoride per liter of water, and the etching step may include immersing the synthetic resin product in the etching solution for 1 to 3 minutes at 10 to 30 ° C .

The synthetic resin product plating method of the present invention includes an ultrasonic washing step of immersing the synthetic resin product in water mixed with a detergent and shaking the synthetic resin product by ultrasonic waves between the laser activating step and the catalyst adsorption promoting step As shown in FIG.

The synthetic resin product plating method of the present invention is characterized in that the synthetic resin product is immersed in a degreasing solution formed by mixing water and sodium metasilicate for 5 to 10 minutes between the laser activation step and the catalyst adsorption promotion step, An alkaline degreasing step of degreasing and expanding the micropores, and a neutralizing step of neutralizing the degreasing solution remaining on the surface of the synthetic resin product by immersing the synthetic resin product in an acidic solution.

The synthetic resin product plating method of the present invention may further comprise a plating pretreatment step between the etching step and the electroless plating step in which the synthetic resin product is immersed in an aqueous solution of sulfuric acid to activate the metal catalyst of the plating area.

The catalyst adsorption promotion step and the metal catalyst adsorption step may be performed by immersing the synthetic resin product in the mixed catalyst solution in which the promoter solution and the metal catalyst solution are mixed at 10 to 30 ° C for 2 to 8 minutes, , And the mixed catalyst solution is prepared by mixing 5 to 50 g of tin chloride (SnCl ₂ ), 0.1 to 0.4 g of palladium chloride, and 10 to 50 ml of 36% hydrochloric acid per liter of water, 5 to 50 g of ferric tin (SnCl ₂ ), 0.1 to 1 g of palladium sulfate, and 1 to 100 ml of 98% sulfuric acid.

The promoting solution may be a solution containing cobalt (Co) as the adsorption promoting material.

According to the present invention, since a plating layer of various patterns can be formed on the surface of a pure synthetic resin product such as polycarbonate, weather resistance, chemical resistance, and cost can be reduced.

In addition, since volatile organic solvents are not used in the process of work, it is possible to reduce the environmental pollution problem and the risk of fire accident, and the convenience of operation and safety are improved.

1 is a flowchart illustrating a synthetic resin product plating method according to an embodiment of the present invention.
FIGS. 2 to 7 are enlarged cross-sectional views sequentially illustrating a synthetic resin product plating method according to an embodiment of the present invention.

Hereinafter, a synthetic resin product plating method according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings. The terminology used herein is a term used to properly express the preferred embodiment of the present invention, which may vary depending on the intention of the user or operator or the custom in the field to which the present invention belongs. Therefore, the definitions of these terms should be based on the contents throughout this specification.

FIG. 1 is a flowchart illustrating a method of plating a synthetic resin product according to an embodiment of the present invention, and FIGS. 2 to 7 are enlarged cross-sectional views sequentially illustrating a synthetic resin product plating method according to an embodiment of the present invention.

Referring to FIG. 1, the synthetic resin product plating method according to an embodiment of the present invention sequentially includes a laser activation step S10, an ultrasonic cleaning step S20, an alkali degreasing step S30, a neutralization step S40, Step S50, a metal catalyst adsorption step S60, an etching step S70, a plating pretreatment step S80, a primary copper layer plating step S90, and a secondary copper layer plating step S100. An antenna of a metal material formed on the surface of a synthetic resin product by applying the synthetic resin product plating method is called a so-called LMA (laser manufacturing antenna).

The synthetic resin product may be manufactured by injection molding a pure polycarbonate resin not containing a heavy metal component. For example, a case of a mobile device such as a smart phone, a tablet PC, Or a housing.

Referring to FIGS. 1 and 2 together, the laser activation step S10 irradiates a laser only on the plating area PA of the synthetic resin product 1, and a large amount of micropores 2), that is, a step of forming a fine crack. The laser may be, for example, a diode laser, an ultraviolet laser, an excimer laser, or the like, preferably a diode laser having a wavelength of 800 to 1100 nm.

The ultrasonic washing step S20 is a step of washing the synthetic resin product 1 by immersing the synthetic resin product 1 in water mixed with a cleaning agent and shaking it with ultrasonic waves. Foreign matters such as dust are stuck in the micro pores 2 formed through the laser activation step S10 and it is difficult to remove foreign matter from the plating area PA through a typical washing process. It is possible to cleanly remove foreign matter from the micropores 2 of the plating area PA through ultrasonic cleaning (S20).

1 and 3, the alkaline degreasing step S30 is a step of immersing the synthetic resin product 1 in the degreasing solution formed by mixing water and sodium metasilicate into the synthetic resin product 1 through the ultrasonic cleaning step S20, Degassing the surface, and expanding the micropores 2.

Specifically, the degreasing solution is an alkaline solution formed by mixing 40 to 90 g of sodium metasilicate per 1 L of water, and the synthetic resin product (1) is immersed in the degreasing solution at a temperature of 60 to 70 캜. The alkaline degreasing step (S30) removes the remnants of the carbon (C) remaining in the micropores (2) and forms the expanded pores (2a).

The neutralization step (S40) is a step of immersing the acidic solution in the alkaline degreasing step (S30) and neutralizing the remaining degreasing solution on the surface of the synthetic resin product (1). The acidic solution may be an aqueous hydrochloric acid solution obtained by mixing 15 to 20 vol% of 36% hydrochloric acid and 80 to 85 vol% of water. The synthetic resin solution (1) is dipped in the hydrochloric acid aqueous solution at 10 to 30 ° C for 3 to 7 minutes Can be neutralized. Alternatively, the acidic solution may be an aqueous solution of sulfuric acid mixed with 98% hydrochloric acid 5 to 10 vol% and water 90 to 95 vol%, and the synthetic resin product (1) may be added to the sulfuric acid aqueous solution at a temperature of 40 to 60 ° C in an amount of 1 to 3 Min. ≪ / RTI >

1 and 4, the catalyst adsorption promotion step S50 is a step of promoting the adsorption of the synthetic resin product 1 to the promoting solution so that the adsorption promoting substance 5 for promoting the adsorption of the metal catalyst is attached to the surface of the synthetic resin product 1, .

In the embodiment of the present invention, the promoting solution is a solution obtained by mixing 5 to 50 g of tin chloride (SnCl ₂ ) and 10 to 50 ml of 36% hydrochloric acid (HCl) per liter of water, Is tin (Sn). The synthetic resin product 1 is immersed in the promoting solution at a temperature of 10 to 30 캜 for 2 to 8 minutes so that the adsorption promoting substance 5 is adhered to the entire surface of the synthetic resin product 1. In another embodiment of the present invention, the promoting solution may be a solution containing cobalt (Co) as an adsorption promoting material.

1 and 5 together, the metal catalyst adsorption step S60 is a step of immersing the synthetic resin product 1 in the metal catalyst solution after the catalytic adsorption promotion step S50 to immerse the metal catalyst 6 in the synthetic resin product 1, On the surface of the substrate. In an embodiment of the present invention, the metal catalyst solution is prepared by mixing 0.1 to 0.4 g of palladium chloride and 10 to 50 ml of 36% hydrochloric acid per liter of water, 0.1 to 1 g of palladium sulfate, and 98 And 1 to 100 ml of sulfuric acid.

Here, the metal catalyst 6 is palladium (Pd). If the synthetic resin product 1 is immersed in the metal catalyst solution at a temperature of 10 to 30 ° C for 2 to 8 minutes, the metal catalyst 6 forms a metal compound together with the adsorption promoting substance 5 to form a surface of the synthetic resin product 1 Is adsorbed throughout.

Tin (Sn) has an affinity for palladium (Pd) and attracts palladium (Pd). When tin (Sn) penetrates the surface of the synthetic resin product (1), palladium (Pd) drawn by tin (Sn) easily penetrates the surface of the synthetic resin product (1) and is fixed. However, tin (Sn) and palladium (Pd) penetrate deeper than the periphery of the pores 2a and are stably fixed in the pores 2a.

On the other hand, the catalytic adsorption promotion step (S50) and the metal catalyst adsorption step (S60) may be carried out simultaneously without being separately performed sequentially. (S50) and a metal catalyst adsorption step (S60) by immersing the synthetic resin product (1) at 10 to 30 ° C for 2 to 8 minutes in the mixed catalyst solution in which the promoting solution and the metal catalyst solution are mixed, . The mixed catalyst solution is prepared by mixing 5 to 50 g of tin chloride (SnCl ₂ ), 0.1 to 0.4 g of palladium chloride, and 10 to 50 ml of 36% hydrochloric acid per liter of water, 5 to 50 g of ferric tin (SnCl ₂ ), 0.1 to 1 g of palladium sulfate, and 1 to 100 ml of 98% sulfuric acid.

Referring to FIGS. 1 and 6 together, the etching step S70 is a step of immersing the synthetic resin product 1 in the etching solution through the metal catalyst adsorption step S60.

Specifically, the etching solution is a solution obtained by mixing 50 to 100 g of ammonium fluoride per liter of water. The etching solution is immersed in the etching solution at a temperature of 10 to 30 DEG C for 1 to 3 minutes to perform an etching step (S70) .

Tin (Sn) as the adsorption promoting material 5 is removed from the surface of the synthetic resin product 1 and the area other than the plating area PA on the surface of the synthetic resin product 1, that is, the micro pores 2a The metal catalyst 6, that is, palladium (Pd) is removed in the region where there is no catalyst (not shown). As a result, only the metal catalyst 6 adsorbed on the micro pores 2a of the plating area PA is left through the etching step S70, and the metal material in the peripheral area is removed.

The pre-plating step S80 is a step of activating the metal catalyst 6 in the plating area PA by immersing the synthetic resin product 1 subjected to the etching step S70 into the aqueous sulfuric acid solution. Specifically, the sulfuric acid aqueous solution is a solution obtained by mixing 10 to 15 vol% of 98% sulfuric acid and 85 to 90 vol% of water. The synthetic resin product (1) is immersed in the sulfuric acid aqueous solution at a temperature of 40 to 60 ° C for 1 to 3 minutes . Thereby, the metal catalyst 6 of the plating area PA is activated so as to act as a seed of the plating step, and a part of the metal material remaining in the area other than the plating area PA is cleanly removed.

The tin (Sn) is dissolved in the etching solution or the aqueous sulfuric acid solution, and is cleanly removed from the surface of the synthetic resin product 1 through the etching step S70 and the plating pretreatment step S80. However, the palladium (Pd) adsorbed on the pores 2a penetrates deeply into the surface of the synthetic resin product 1 and is not removed in spite of the etching step S70 and the plating pretreatment step S80. The palladium Pd adsorbed on the periphery of the pores 2a is not strongly adsorbed on the surface of the synthetic resin product 1 and is removed from the surface of the synthetic resin product 1 through the etching step S70 and the pretreatment step S80.

1 and 7, the primary copper layer plating step S90 and the secondary copper layer plating step S100 are performed by using the metal catalyst 6 of the plating area PA as a seed, In the step of electroless plating.

The primary copper layer plating step (S90) is a step of dipping the synthetic resin product (1) through the plating pretreatment step (S80) into the copper plating solution. Specifically, the copper plating solution contains copper (Cu) 2.5 to 3 g / L, sodium hydroxide 8 to 9 g / L, formazan 3 to 3.8 g / L, ethylenediamine tetraacetic acid (EDTA) 30 to 35 g / And is performed by immersing the synthetic resin product (1) in the copper plating solution at a temperature of 55 to 65 캜 for 5 to 10 minutes. In the course of performing the primary copper layer plating step (S90), the primary copper layer 10 grows at a rapid rate of about 2 占 퐉 per 5 minutes in the plating area PA.

Since the primary copper layer 10 has a high thickness growth rate but it is difficult to uniformly control the thickness thereof, the secondary copper layer plating step (S100) has a slower thickness growth rate, but a more stable and homogeneous secondary copper layer (12).

Specifically, the secondary copper layer plating step (S100) is performed at a temperature lower than the temperature of the primary copper layer plating step (S90), for example, at a temperature of 40 to 50 DEG C, in the primary copper layer plating step (S90) The copper plating solution (copper plating solution) is immersed in the copper plating solution (step S90). In the course of performing the secondary copper layer plating step S100, the secondary copper layer 12 grows at a slow rate of about 2 to 3 占 퐉 per hour on the primary copper layer 10. The execution time of the secondary copper layer plating step (S100) depends on the design thickness of the copper layers (10, 12).

The present invention may further include a protective layer plating step (S110).

The protective layer plating step S110 may be performed by using a nickel (Ni) alloy or tin (Cu) harder than copper (Cu) on the secondary copper layer 12 to prevent damage to the copper layers 10 and 12 having relatively low hardness Sn) alloy is formed by plating. For example, when the protective layer 14 is formed of nickel-boron mixed with 30 g / L of nickel sulfate, 3 g / L of dimethylamine borane (DMAB) as a reducing agent, 25 g / L of sodium citrate as a complexing agent, The nickel-boron alloy layer can be formed by plating using a plating solution.

The synthetic resin product 1 may be immersed in the nickel-boron plating solution at a temperature of 50 to 65 占 폚 to form a nickel-boron alloy protective layer 14 having a thickness of 1 to 4 占 퐉.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

1: Synthetic resin product 2, 2a: Porosity
5: tin (Sn) 6: palladium (Pd)
10, 12: copper layer 14: protective layer

Claims (11)

A laser activation step of forming micropores on a surface by irradiating a laser on a plating area on the surface of a synthetic resin product;
A catalyst adsorption promoting step of immersing the synthetic resin product in a promoting solution so that an adsorption promoting substance for promoting adsorption of the metal catalyst is adhered to the surface of the synthetic resin product;
A metal catalyst adsorption step of immersing the synthetic resin product in a metal catalyst solution to adsorb the metal catalyst on the surface of the synthetic resin product;
An etching step of dipping the synthetic resin product in an etching solution to remove the adsorption promoting material from the surface of the synthetic resin product and removing the metal catalyst from the surface of the synthetic resin product other than the plating area; And
And an electroless plating step of electroless plating a metal on the plating area using the metal catalyst as a seed. The method according to claim 1,
The electroless plating step includes: 2.5 to 3 g / L of copper (Cu), 8 to 9 g / L of sodium hydroxide, 3 to 3.8 g / L of formazan and 30 to 35 g / L of ethylenediaminetetraacetic acid (EDTA) A primary copper layer plating step of immersing the synthetic resin product in a copper plating solution at a temperature of 55 to 65 DEG C for 5 to 10 minutes to form a primary copper layer; And
And a secondary copper layer plating step of immersing the synthetic resin product in a copper plating solution such as that used in the primary copper layer plating step at a temperature of 40 to 50 DEG C to form a secondary copper layer METHOD OF PLATING SYNTHETIC PRODUCT. 3. The method of claim 2,
The electroless plating step may further include a protective layer plating step of forming a protective layer made of a nickel (Ni) alloy or a tin (Sn) alloy harder than copper (Cu) on the secondary copper layer Wherein the synthetic resin product is plated. The method according to claim 1,
The promoting solution is a solution obtained by mixing 5-50 g of tin chloride (SnCl ₂ ) and 10-50 ml of 36% hydrochloric acid (HCl) per 1 L of water,
Wherein the catalyst adsorption promotion step comprises dipping the synthetic resin product in the promoting solution at 10 to 30 DEG C for 2 to 8 minutes. The method according to claim 1,
The metal catalyst solution is a solution prepared by mixing 0.1 to 0.4 g of palladium chloride and 10 to 50 ml of 36% hydrochloric acid or 0.1 to 1 g of palladium sulfate and 1 to 100 ml of 98% sulfuric acid per liter of water 0.1 to 1 g of palladium sulfate, and 1 to 100 ml of 98% sulfuric acid per liter of water or 1 L of water. The method according to claim 1,
The etching solution is a solution obtained by mixing 50 to 100 g of ammonium fluoride per liter of water,
Wherein the etching step comprises immersing the synthetic resin product in the etching solution for 1 to 3 minutes at 10 to 30 占 폚. The method according to claim 1,
Further comprising an ultrasonic cleaning step of immersing the synthetic resin product in water mixed with a detergent and ultrasonic waves to shake the synthetic resin product between the laser activation step and the catalyst adsorption acceleration step, Product plating method. The method according to claim 1,
The synthetic resin product is dipped in a degreasing solution formed by mixing water and sodium metasilicate between the laser activation step and the catalyst adsorption promotion step for 5 to 10 minutes to degrease the surface of the synthetic resin product, An alkaline degreasing step of expanding the alkaline solution; And
Further comprising a neutralization step of immersing the synthetic resin product in an acidic solution to neutralize the degreasing solution remaining on the surface of the synthetic resin product. The method according to claim 1,
Further comprising a plating pretreatment step between the etching step and the electroless plating step to immerse the synthetic resin product in an aqueous solution of sulfuric acid to activate the metal catalyst in the plating area. The method according to claim 1,
The catalyst adsorption promotion step and the metal catalyst adsorption step may be performed by immersing the synthetic resin product in the mixed catalyst solution in which the promoter solution and the metal catalyst solution are mixed at 10 to 30 ° C for 2 to 8 minutes, And,
The mixed catalyst solution is prepared by mixing 5 to 50 g of tin chloride (SnCl ₂ ), 0.1 to 0.4 g of palladium chloride, and 10 to 50 ml of 36% hydrochloric acid per liter of water, or a solution of tin chloride (SnCl ₂ ), 0.1 to 1 g of palladium sulfate, and 1 to 100 ml of 98% sulfuric acid. The method according to claim 1,
Wherein the promoting solution is a solution containing cobalt (Co) as the adsorption promoting material.

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