KR100954596B1 - Plating method for plastic material surface using conductible media by barrel - Google Patents

Abstract

PURPOSE: A method for partly plating electric barrel on the surface of plastic using a conductive member is provided to improve conductive efficiency of a plated part of a base member using the conductive member and to prevent the discoloration. CONSTITUTION: A method for partly plating electric barrel on the surface of plastic using a conductive member comprises the following steps: a step(S1) eliminating foreign materials from the surface of a base member; a step(S2) plating electroless copper on a printed pattern; a step(S3) performing electric barrel copper planting for 20~30 minutes; a step(S4) performing electric barrel nickel planting for 10~15 minutes; and a steps(S5) performing electrolysis treatment.

Description

Plating method for plastic material surface using conductible media by barrel}

The present invention relates to a plating method of forming a metal plating layer only on a specific portion printed on an insulator such as plastic.

In general, resin materials (plastics) are widely used for lightening and miniaturizing various electric and electronic devices. For example, intena, a built-in antenna of a mobile phone, is formed of a PC (polycarbonate) material having good impact resistance and weather resistance. It has a structure that forms a pattern (loop) for wireless transmission and reception on one surface of the body.

Conventionally, the method of thermally fusion of a metal piece molded into a predetermined pattern to a resin body has been common, but there are many defects such as the metal piece and the resin body being partially separated by the nonuniform adhesion of the pattern, and radio transmission or electromagnetic shielding, etc. There was a drawback that the important properties of the membrane could not be maintained for a long time. For this reason, electroless plating with less change in physical properties is preferred in the method of forming the conductive pattern on the insulator. Electroless plating is a method in which a metal is reduced and precipitated on an article by a reducing agent in a solution containing metal ions, and is distinguished from immersion plating due to an ionization tendency.

In general, the electroless plating process is performed in the order of pretreatment-> chemical copper plating-> catalyst treatment-> electroless nickel plating-> immersion post treatment. The pretreatment process includes treatment of degreasing, etching, neutralization, catalyst, activation and the like. Degreasing treatment removes contaminants such as organic matter, oxides, fingerprints, and dust from the surface of the product to be plated. The etching treatment improves the adhesion between the plating layer and the resin surface. Neutralization treatment is to improve plating coating power and to remove oxide film. Catalytic treatment is to deposit the catalytic metal (Pb) necessary for the start of the chemical plating reaction on the surface of the material. The activation treatment activates the catalyst layer attached to the surface of the material to assist in chemical plating.

Chemical copper plating is to form a copper plating layer which is reduced and precipitated from the plating liquid at a target portion to be plated in the plating liquid. In general, the thickness of the chemical copper plating layer is more than 5㎛ the time required takes 120 minutes to 180 minutes.

In addition, in electroless nickel plating, the thickness of the plating layer is set to 3 µm or more. At this time, the plating time is about 30 to 40 minutes.

The problem with this conventional method is that all the plating process takes a lot of time because the electroless plating is performed. Therefore, there is a problem of poor productivity. In addition, in the case of electroless plating, there is a problem that the life of the plating solution is shortened and the life is shortened. In addition, there is a problem in that the cost increases because the plating solution must be replaced frequently.

An object of the present invention is to solve the problems described above to change the conventional electroless plating method to the electrolytic plating method, by barrel plating using a conductive member to significantly shorten the plating time and to enable mass production The present invention provides a method of partially electric barrel plating a plastic surface by using an improved current carrying member.

In order to achieve the above object, the method of partially electric barrel plating the plastic surface by using the current-carrying member according to the present invention, which selectively plate the metal on the surface of the base member of the plastic material difficult to directly plate the metal As a method,

A pretreatment step of pretreating the surface of the base member;

A strike plating step of performing chemical copper plating on the pattern printed on the base member after the pretreatment step for 5 to 10 minutes;

An electric barrel copper plating step of performing an electric barrel copper plating for 20 to 30 minutes after the strike plating step;

An electric barrel nickel plating step of performing an electric barrel nickel plating for 10 to 15 minutes after the electric barrel copper plating step; And

And an electrolytic post-treatment step of performing an electrolytic post-treatment after the electric barrel nickel plating step.

In the electric barrel copper plating step and the electric barrel nickel plating step, the electric barrel plating is performed by mixing a plurality of conductive current-carrying members in a mixture of the plating solution and the base member.

The component of the energizing member is preferably iron (Fe).

The shape of the energizing member is preferably spherical or cylindrical.

In the electric barrel copper plating step and the electric barrel nickel plating step, it is preferable to arrange the mesh member of the mesh shape on the inner circumferential surface of the barrel so that the conducting member flowing in the barrel is not lost.

In the electric barrel copper plating step and the electric barrel nickel plating step, the mixing ratio of the base member and the energizing member is preferably mixed in a ratio of 1: 3 by the area ratio of each member.

In the electro-barrel copper plating step and the electro-barrel nickel plating step, the sum of the volume of the base member and the energization member charged in the barrel is preferably 60% to 70% of the barrel volume.

In the method of partially electric barrel plating on a plastic surface using the energizing member according to the present invention, in the method of forming a metal plating layer on a non-conductor, the conventional electroless plating method is changed to an electrolytic plating method, The use of an energizing member on the plate significantly shortens the plating time, thereby improving productivity and reducing the production cost.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a process diagram of a method of partially electric barrel plating on a plastic surface by using an energizing member according to the present invention. Figure 2 is a view showing the shape of the energizing member used in the electric barrel copper plating step and the electric barrel nickel plating step shown in FIG. 3 is a view showing a mesh member form used in the electro-barrel copper plating step and the electro-barrel nickel plating step shown in FIG. 4 is a photograph showing a comparison between the adhesion test results of the plated layer electroplated using the method shown in FIG. 1 and the plated layer electroplated using the conventional method.

1 to 4, a method of partially electric barrel plating on a plastic surface by using an energizing member according to a preferred embodiment of the present invention (hereinafter referred to as "plating method") is a plastic that is difficult to directly plate the metal A metal is selectively plated on the surface of a base member of a raw material.

The plating method includes a pretreatment step (S1), a strike plating step (S2), an electric barrel copper plating step (S3), an electric barrel nickel plating step (S4), and an electrolytic post-treatment step (S5). .

The pretreatment step (S1) is to clean the surface of the portion to be plated by performing a treatment such as removing foreign matter from the surface of the base member, which is electrically insulated, such as polycarbonate (PC). In particular, the surface of the base member is printed with a selective plating ink in a specific pattern on a specific portion to be plated. In this case, when the metal is selectively plated only on a specific portion of the base member, it is used to form an internal antenna called an antenna that directly forms the antenna of the cellular phone on the case. The selective plating ink may employ well-known inks, and thus detailed description thereof will be omitted. As the selective plating ink, for example, an ink such as that disclosed in Korean Patent Laid-Open Publication No. 2008-0042317 may be used.

The strike plating step S2 is performed after the pretreatment step S1. In the strike plating step (S2), the chemical copper plating is performed on the printed pattern on the base member for 5 to 10 minutes. The strike plating step S2 is performed in a state where the base member is immersed in a plating solution. In the strike plating step (S2), copper ions are reduced and precipitated in the catalyst layer, thereby copper plating. Since the process of giving only the metal conduction property to the printed portion of the base member, it is performed only for a short time. In the conventional process, since the plating layer should be formed at 5 μm or more, it took 120 minutes to 180 minutes, but in the strike plating step (S2) according to the present invention, in order to prevent the deposited copper film from being dissolved in the electric barrel plating process described later. Only plate the thickness of at least 0.2 to 0.3㎛. Therefore, the required time of the strike plating step (S2) is enough 5 minutes to 10 minutes. If it is shorter than this time, there is a problem that the thickness of the plating layer is too thin. If it is kept longer than this time, there is a problem that the adhesion between the chemical copper plating layer and the electroplating layer described later is inferior. The components of the plating solution used in the strike plating step (S2) roughly include 3 to 5 g / L copper sulfate, 20 to 30 g / L lotel salt, 5 to 10 g / L formalin, and 5 to 8 g / L caustic soda. It is preferable that the temperature of the bill is maintained at 20 to 30 ° C. In addition, the hydrogen ion concentration (pH) of the plating liquid is preferably maintained at 12 to 12.5. When the concentration of the plating liquid is higher than the above range and the temperature is higher than the above temperature range, the plating speed is increased, but the plating surface becomes rough and the appearance is uneven. Under the opposite conditions, a dense deposition film is obtained, but the plating rate is lowered and insufficient plating is performed.

The electro-barrel copper plating step (S3) is performed after the strike plating step (S2). In the electric barrel copper plating step (S3), the electric barrel copper plating is performed for 20 to 30 minutes. In the electric barrel copper plating step (S3), plating is performed by mixing a plating solution, a base member, and a plurality of energizing members 10 inside the rotating barrel. The conducting member 10 was introduced to improve the speed and plating quality of the plating by forming an electrical passage between the printing portion of the base member and the electrode. The component of the conductive member 10 is preferably iron (Fe). The conducting member 10 may be formed in a spherical or cylindrical shape as shown in FIG. When the conductive member 10 is spherical, the diameter is preferably about 4.8 mm and the circumference is about 15 mm. On the other hand, when the conductive member 10 has a cylindrical shape, it is preferable that the diameter of the cross section is about 1 mm and the length is about 15 mm. The mixing ratio of the conductive member 10 is preferably mixed in a ratio of 1: 3 by the ratio of the surface area of the base member and the conductive member 10. In addition, in the electro-barrel copper plating step (S3), the sum of the volume of the base member and the energization member charged in the barrel is preferably 60% to 70% of the barrel volume. The composition of the plating liquid used in the electro-barrel copper plating step (S3) includes 60 to 70 g / l copper cyanide, 50 to 70 g / l sodium cyanide, and 10 to 20 g / l lotose salt. It is preferable to maintain the temperature of a plating liquid at 50-60 degreeC, hydrogen ion concentration (pH) at 12-12.5, voltage 4-8V, and rotation speed of a barrel about 10-15 rpm.

The electro-barrel nickel plating step S4 is performed after the electro-barrel copper plating step S3. In the electric barrel nickel plating step (S4), the electric barrel nickel plating is performed for 10 to 15 minutes. In the electric barrel nickel plating step (S4), as in the electric barrel copper plating step (S3), the conductive member 10 is mixed with the plating solution to perform plating. The material, shape, size, and loading volume of the energizing member 10 will be referred to the description of the electric barrel copper plating step S3. The plating liquid used in the electric barrel nickel plating step (S4) is a sulfamic acid nickel plating bath. This plating liquid has a low stress and good adhesion compared to a general nickel plating liquid, so that cracks do not easily occur, and thus the electrical properties of the printing resin are good. The composition of this plating solution contains 350-450 g / l nickel ammonium sulfate, 5-10 g / l nickel chloride, and 30-45 g / l boric acid. It is preferable to maintain the temperature of this plating liquid at 50-60 degreeC, and hydrogen ion concentration (pH) at 3.5-4.5. The voltage applied to the plating liquid is preferably 4 to 8 V, and the rotation speed of the barrel is preferably 10 to 15 rpm.

In the electric barrel copper plating step (S3) and the electric barrel nickel plating step (S4), it is preferable to arrange the mesh member 20 of the net shape on the inner circumferential surface of the barrel so that the conducting member flowing in the barrel is not lost. Do. The shape of the mesh member 20 is shown in FIG. 3.

The electrolytic post-treatment step (S5) is performed after the electric barrel nickel plating step (S4). The electrolytic post-treatment step (S5) is more effective in preventing discoloration because the electrical effect is added compared to the conventional deposition type to fill the plated layer well and the coating power is excellent.

In this way, a metal plating layer of an antenna pattern was formed on the surface of the base member by using a mobile phone case made of polycarbonate (PC) as a base member. The plating method according to the present invention employs an electroplating method as compared to the conventional plating method, thereby providing an effect of significantly increasing productivity since the time required for plating is significantly shorter than that of the conventional method. In particular, the conducting member 10 significantly improves the conduction efficiency of the plated portion of the base member to further double the effect of the present invention. Numerically, the plating method according to the present invention had an effect of shortening the plating time by only about 20 to 25% compared to the conventional plating method.

Figure 4 compares the test results of the adhesion strength of the plated layer formed using the ink according to the present invention and the plated layer formed using a conventional ink. The adhesion strength test of the plating layer used the cross-cutting test which is generally performed in the industrial field. The purpose of the adhesion test is to verify the adhesion between the surface-treated material and the base material on the mechanical parts to prevent the problem of peeling, peeling, etc. under the conditions of consumer use. Adhesion test method is to cut the surface of the part for adhesion test by using a knife blade to the depth of the surface treated 11 places at intervals of 1mm in width X length. The result is 100 grids of 1 mm × 1 mm. Remove any burrs or foreign matter from the resulting lattice. And the adhesive tape is adhere | attached so that a bubble may not generate | occur | produce on the grid | lattice formed. The glued tape is pulled out quickly at a 90 ° angle to the lattice plane. Repeat this process four to five times. As a result, when it falls below 20% per one grating (1mmX1mm), it determines with a pass.

The plating layer formed by the method according to the present invention was markedly shortened in comparison with the conventional method also in the time for forming the plating layer. In addition, referring to Figure 4 it can be seen that the adhesion strength of the plating layer formed using the ink according to the present invention is superior to the adhesion strength of the plating layer formed using a conventional method.

The present invention has been described above with reference to preferred embodiments, but the present invention is not limited to the above examples, and various forms of embodiments may be embodied without departing from the technical spirit of the present invention.

1 is a process diagram of a method of partially electric barrel plating on a plastic surface by using an energizing member according to the present invention.

Figure 2 is a view showing the shape of the energizing member used in the electric barrel copper plating step and the electric barrel nickel plating step shown in FIG.

3 is a view showing a mesh member form used in the electro-barrel copper plating step and the electro-barrel nickel plating step shown in FIG.

4 is a photograph showing a comparison between the adhesion test results of the plated layer electroplated using the method shown in FIG. 1 and the plated layer electroplated using the conventional method.

<Description of the symbols for the main parts of the drawings>

10 ... electric member 20 ... mesh member

S1 ... pretreatment step S2 ... strike plating step

S3 ... Electric Barrel Copper Plating Step S4 ... Electric Barrel Nickel Plating Step

S5 ... Electrolytic Post-Processing Steps

Claims (6)

As a method of selectively plating a metal on the surface of the base member of the plastic material which is difficult to directly plate the metal, A pretreatment step of removing foreign matter from the surface of the base member which is electrically insulated; A strike plating step of performing chemical copper plating on the printed pattern for 5 to 10 minutes by reducing and depositing copper ions in the state in which the base member is deposited in a plating solution after the pretreatment step; An electric barrel copper plating step of inserting a plating solution and the base member into the rotating barrel after the strike plating step and performing electric barrel copper plating for 20 to 30 minutes; An electric barrel nickel plating step of charging an electric barrel nickel plating for 10 to 15 minutes by charging a plating solution and the base member into the rotating barrel after the electric barrel copper plating step; And And an electrolytic post-treatment step of performing an electrolytic post-treatment after the electric barrel nickel plating step. In the electro-barrel copper plating step and the electro-barrel nickel plating step, electro-barrel plating is performed by mixing a plurality of conductive current-carrying members in a mixture of a plating solution and a base member. And the component of the conductive member is iron (Fe), wherein the barrel is partly subjected to electric barrel plating on the plastic surface. delete The method of claim 1, And a shape of the current carrying member is spherical or cylindrical, and partly electric barrel plating the plastic surface using the current carrying member. The method of claim 1, In the electric barrel copper plating step and the electric barrel nickel plating step, the mesh surface of the barrel is disposed on the inner circumferential surface of the barrel so that the conducting member flowing in the barrel is not lost. On how to partially electroplate. The method of claim 1, In the electric barrel copper plating step and the electric barrel nickel plating step, the mixing ratio of the base member and the conducting member is mixed on the surface of the plastic using the conducting member, characterized in that the ratio is 1: 3 in the area ratio of each member. Partly electric barrel plating method. The method of claim 1, In the electro-barrel copper plating step and the electro-barrel nickel plating step, the sum of the volume of the base member and the energizing member charged in the barrel is 60% to 70% of the barrel volume to the plastic surface using the energizing member. Partly electric barrel plating method.

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