KR20090046385A - Electroless plateing method and electroless plate using thereof - Google Patents

Abstract

The present invention relates to an electroless plating method and a plated body using the same, and more particularly, to an electroless plating method using catalyst particles and a plated body using the same.

In the present invention, the catalyst particles are sprayed onto the surface of the member to be plated, fixed to the surface, and electroless plated, thereby eliminating the conventional etching process and wet pretreatment process.

Dry spraying

Description

ELECTROLESS PLATEING METHOD AND ELECTROLESS PLATE USING THEREOF}

The present invention relates to an electroless plating method and a plated body using the same, and more particularly, to an electroless plating method using catalyst particles and a plated body using the same.

Electroless plating, also called chemical plating or self-catalyst plating, is a method of depositing metal on the surface of a workpiece by reducing the metal ions in an aqueous metal salt solution catalytically by means of a reducing agent without receiving electrical energy from the outside. It is widely used for the surface plating of parts made of materials such as plastic that cannot or cannot be supplied with electricity.

As a catalyst for electroless plating, an aqueous solution of a colloidal solution of tin and palladium or a palladium compound such as palladium chloride is used. Since such a catalyst uses an inorganic palladium compound, when it is going to dissolve in the organic solvent which is excellent in the wettability property than water, and which can melt | dissolve other organic compounds, such as resin, it is low in solubility, This settling had a problem that a uniform solution could not be obtained. In addition, although palladium acetate having a lower fatty acid is soluble in methanol depending on the concentration, there is a problem that palladium immediately precipitates. Accordingly, various pretreatment methods for electroless plating have been developed.

Korean Patent Application Publication No. 10-2006-0114024 filed by Nikko Kinzoku Co., Ltd. discloses an electroless plating pretreatment agent comprising a noble metal soap of fatty acids having 5 to 25 carbon atoms and a silane coupling agent having a functional group having a metal trapping ability. It is starting. In addition, Korean Patent Publication No. 10-2007-0088611 discloses a method of performing electroless plating after pretreatment with an organic solvent containing a silane coupling agent and an epoxy resin in a polyimide film in order to increase plating strength.

On the other hand, in electroless plating, metal ions are selectively deposited only on the surface of a component made of a material such as plastic, so that a catalyst for reducing activation energy is attached to the surface of the component so that the plating effect can be obtained. The plastic surface is generally used to increase the roughness through etching so that the catalyst can be easily attached and present.

As the etching method, an acid etching method in which a plastic is immersed in a strong oxide acid such as chromic acid-sulfuric acid or phosphoric acid is commonly used. This acid etching method has the advantage of simple process and excellent surface roughness improvement effect by etching, but it has problems such as generation of human harmful substances that strongly irritate the skin and mucous membrane of worker and continuous increase of environmental treatment cost. . The dry plasma surface treatment method has been proposed as an alternative process for solving the problem of the acid etching method, but there are problems such as difficulty in continuous process and expensive equipment.

In addition, Japanese Patent Application Laid-Open No. Hei-1-092377 discloses a method of pretreating the resin material with ozone gas and then electroless plating the treated resin material. According to this publication, the unsaturated bonds of the resin material are broken down by ozone to change into small molecules, whereby molecules having different chemical constituents coexist on the surface of the resin material, resulting in a decrease in flatness and a rough surface. . Thus, the coating on which the electroless plating is formed is taut to the roughened surface to prevent the coating from peeling easily therefrom.

In addition, Japanese Patent Application Laid-open No. Hei 8-092752 discloses a polyolefin that is roughened with a resin material by etching, the roughened polyolefin is brought into contact with ozone water, and then roughened with a solution containing a cationic surface active agent. A method of treating is disclosed.

In the above-described method, the adhesion of the plating coating is increased by the so-called anchor effect by roughening the surface of the resin material. However, according to this method, the surface flatness of the resin material is reduced. Thus, in order to provide metallic luster while maintaining a good appearance to the resin material, the plating coating must be thick, which leads to an increase in man hour.

In addition, in the method of roughening the surface of the resin material by etching, dangerous substances such as chromic acid, sulfuric acid, and the like must be used, resulting in problems such as liquid waste treatment resulting. This method also cannot solve the problem of decreasing the surface flatness of the resin material.

Korean Patent Application No. 2005-47121 filed by Kim Jin-soo discloses a method of making a treatment liquid water-soluble over the entire process of the electroless plating process. Pretreatment according to the present invention comprises a washing step of washing the polycarbonate and the coating material containing polycarbonate; A nitric acid treatment step of removing nitric acid from the surface of the washed object to remove additives from the surface; A pretreatment solution treatment step of inflating the surface by treating the nitric acid with a pretreatment solution to which a surfactant is added; A first etching step after the pretreatment solution is immersed in an etching solution to which chromic anhydride, sulfuric acid, an antifoaming agent, and a deposition agent are added; A second etching step of etching the etching solution twice while stirring at a constant speed; A neutralization step of neutralizing the mixture with a mixed solution of neutralizing solution, hydrochloric acid and water after the etching; A polarization step of imparting polarity by treating the polarization solution with a mixed solution of hydrochloric acid and water after the neutralization treatment; An active treatment step of treating the solution with hydrochloric acid and sulfuric acid after the polarization; A chemical copper plating step of electrolytic copper plating after the activation treatment; A nickel plating step of electroless nickel plating after the chemical copper plating; It consists of a drying step of drying the nickel-plated workpiece.

Korean Patent Application No. 2001-89839, filed by Daishin Chemical Company, Limited, et al., Discloses an electroless plating method in which a film containing a conductive metal oxide is formed on a surface of a non-conductive material, and then subjected to a catalyst applying process. have.

In order to solve the above problems, Japanese Patent Laid-Open Nos. 10-088361 and 8-253869 disclose a method of irradiating a resin material with ultraviolet light and electroless plating the obtained resin material. By ultraviolet irradiation, the surface of the resin material is activated, and the active groups on the activated resin material chemically bond with the active metal particles as the plating material, thereby forming a plating coating having excellent adhesion. However, the method of irradiating ultraviolet rays requires a large amount of energy in order to activate the surface of the resin material, so that the resin material is deteriorated by the hot rays from the light source.

In Korean Patent No. 697051, issued to Toyota Shisha Co., Ltd., a resin material is brought into contact with a solution containing ozone, and irradiated with ultraviolet rays, thereby activating by ozone water treatment and activation by ultraviolet treatment. The plating coating method which has the outstanding adhesive strength by the process is disclosed. Further, 555928 discloses a method of treating in an ozone-containing solution and then contacting at least one of the anionic and nonionic surfactants with a solution containing an alkali component.

In addition, in Korean Patent 781813, the surface of the plastic resin is etched in nickel plating on the engineering plastic resin to increase the surface roughness, and after immersion in the palladium salt and the hydrochloric acid solution containing Pd as a catalyst metal as a catalyst for nickel plating. And a method of forming a catalyst layer after immersion and immersing in a chemical nickel plating solution to form a conductive film.

Korean Patent No. 589253 discloses a method of forming a plating layer on a ceramic substrate. In the method of forming a metal wiring on a ceramic substrate, an activated palladium (Pd) nucleus is formed on the sintered ceramic substrate after degreasing and etching, copper is plated, and nickel or gold is sequentially electroless plated.

Conventional inventions generally suffer from the problem that palladium salts are expensive and difficult to selectively plate on complex structures by being wet. Selective plating is possible on some photolithography planes, but there is still a problem that it is difficult to apply to three-dimensional solid structures. Therefore, in the case of semiconductor parts, electroless plating is not performed on moldings to shield electromagnetic waves, and external electromagnetic waves are blocked by covering a conductive metal case. However, the manufacturing cost increases because the conductive metal case must be manufactured separately, and the case is covered separately. In addition, the metal case is vulnerable to moisture, which causes rust when stored or used for a long period of time. Moreover, the problem of being unfriendly to the environment continues due to the etching of the member to be plated and the use of the pretreatment solution.

Therefore, there is a continuing demand for new methods that can solve the problems of etching and wet transfer methods.

It is an object of the present invention to provide a novel electroless plating method without an etching process.

Another object of the present invention is to provide a plated plated by an electroless plating method without an etching process.

Yet another object of the present invention is to provide a dry pretreatment method for electroless plating.

Another object of the present invention is to provide a dry pretreatment apparatus for electroless plating.

Still another object of the present invention is to provide a new electroless plating method and electric and electronic components using the same.

In order to achieve the above object, the electroless plating method of the present invention is characterized by plating the catalyst particles fixed to the plated member.

In the present invention, the catalyst particle means a particle in a solid state that can deposit a metal component and plate a metal on the surface of the member to be plated in an electroless plating process, and form a plated film on the surface of the member to be plated. There is no special limitation as long as it can.

In the practice of the present invention, the catalyst particles are silicon (Si) nickel (Ni), palladium (Pd), gold (Au), silver (Ag), platinum (Pt), graphite, copper particles, alloy particles thereof, And particles of these compounds, for example, particles such as halides, hydroxides, sulfates, carbonate compounds and the like can be used.

In one embodiment of the present invention, the silicon particles can be used as a catalyst component, including the use of silicon particles modified to N type or P type or the like. The silicon particles may be used alone, or may be used by mixing with particles such as alumina (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), silicon carbide (SiC), and the like.

The catalyst particles preferably have an average diameter of about 1-100 μm so as to be sprayed and fixed in the form of particles on the surface of the member to be plated. The catalyst particles can be purchased commercially or used by grinding the raw material into the mill. The grinder may be a conventional grinder, ball mill, etc., there is no particular limitation.

In the present invention, the catalyst particles can be fixed by injecting the catalyst particles to the plated member, preferably, in order to prevent the plated film from being peeled off from the plated member, by spraying at least a portion of the particles to be inserted into the surface It is preferable to be fixed.

In the practice of the present invention, the fixation of the catalyst particles may be performed by spraying the catalyst particles having an average diameter of about 1-100 μm to the plated member at a pressure of 0.1-3.0, preferably 0.6-0.8 kg _f / cm 2. By spraying together. According to a preferred embodiment of the invention, the catalyst is injected and fixed in a dry spray method in which fine catalyst particles are mixed and injected into the air injected at a constant pressure.

According to the metal plating method of this invention, a to-be-plated member is not restrict | limited to the property and state. Insulation plates, such as inorganic materials, such as glass and ceramics, plastic materials, such as polyester, polyamide, polyimide, and fluororesin, its film, sheet | seat, fiber, and epoxy resin reinforced with the glass cloth base material as needed. It can be applied to an insulator such as an insulating material or a plated member having low conductivity such as a semiconductor such as a Si wafer, and the plated member can be suitably applied to a transparent glass plate, a Si wafer, and other semiconductor substrates. Further, the plated member may be applied to the powder, for example, glass beads, molybdenum disulfide powder, magnesium oxide powder, graphite powder, SiC powder, zirconium oxide powder, alumina powder, silicon oxide powder, mica flake, glass fiber, silicon nitride And Teflon (registered trademark) powder. In a preferred embodiment of the present invention, the to-be-plated member may have a lower hardness than the catalyst particles so that the injected catalyst particles may be partially inserted and fixed.

In the present invention, the electroless plating method is not particularly limited as long as the metal ions can be self-catalyzed by the force of the reducing agent to precipitate the metal on the surface of the workpiece. In the present invention, the type of the film formed by the electroless plating is a conductive coating film, preferably nickel, copper, silver, gold or alloy plating thereof.

The present invention in one aspect, according to the object of the present invention, the plated member; Catalyst particles fixed to the plated member; And it provides a plated body comprising a plated layer.

According to another aspect of the present invention, there is provided an electroless plating pretreatment method, wherein the catalyst particles are sprayed and fixed to a member to be plated.

In the present invention, the catalyst particles are silicon (Si) nickel (Ni), palladium (Pd), gold (Au), silver (Ag), platinum (Pt), graphite, copper particles, alloy particles thereof, and Particles of these compounds, for example, particles such as halides, hydroxides, sulfates, carbonate compounds and the like can be used. In one embodiment of the present invention, the silicon particles can be used as a catalyst component, it is also possible to use silicon particles modified to N type or P type or the like. The silicon particles may be used alone, or may be used by mixing with particles such as alumina (Al ₂ O ₃ ), silicon oxide (SiO ₂ ), silicon carbide (SiC), and the like.

The catalyst particles preferably have an average diameter of about 1-100 μm so as to be sprayed and fixed in the form of particles on the surface of the plated member, in order to prevent the plating film from being peeled off from the plated member, It is preferable that a part is fixed while being inserted into the surface.

In the present invention, the member to be plated may be made of a material such as a thermosetting resin or a thermoplastic resin, epoxy resin, wood, ceramic. In the practice of the invention, the plated member includes a plastic exterior material, a semiconductor element, a printed circuit board, an optical semiconductor, a remote control receiving element, an optical sensor, and the like.

In the present invention, the plating layer is nickel, copper, silver, gold or an alloy plating gold layer thereof, preferably a metal layer plated through electroless plating.

In another aspect, the present invention provides a use of the electroless plating pretreatment agent of the silicon particles. It is preferable that the said silicon particle has an average particle diameter of 1-100 micrometers.

Hereinafter, the present invention will be described in more detail with reference to Examples.

The effect of the present invention by the configuration and action as described above has the effect of electromagnetic shielding and light shielding by forming a metal plating layer on the surface of the semiconductor element molded with a plastic resin. In addition, after electroless plating, it is post-treated as nickel or black nickel, so that the surface strength is excellent, wear resistance and heat resistance are improved, and there is an oxidation preventing effect by external contact. The present invention is applicable to plastic resins, such as mobile phones, PDAs, notebooks, and is a useful invention to have a decorative effect of glossy or matte and electromagnetic shielding effect.

Example

Example 1.

A light receiving sensor and an operation IC are mounted on the lead frame, and a semiconductor device for remote control reception is formed as an EMC mold to form a semicircular light receiving window as shown in FIG. 1. The surface of the structure was enlarged 500 times to observe the surface, and the results are shown in FIG. 2.

After shielding the light receiving window with a simple shield, in order to plate the surface of the structure with nickel, first, a silicon (Si) particle having an average particle diameter of 2 µm was used as a catalyst particle at a pressure of 0.2 kg _f / cm2 on the surface of the structure. / C). The surface of the structure after spraying is shown in FIG. 3.

The structure pretreated by the catalyst particle spray was immersed in a nickel chloride plating solution. Nickel chloride plating solution is composed of pure water, sodium hypophosphite (NaH ₂ PO ₂ ), ammonium citrate ((NH ₄ ) ₂ HC ₆ H ₅ O ₇ ), ammonium chloride (NH ₄ Cl), nickel chloride (NiCl ₂ ) , PH was adjusted as aqueous ammonia (NH ₄ OH). The temperature of the solution during the immersion was 92 ℃ or more, the immersion time proceeded for about 10 minutes. After dipping, the film was stabilized by washing with water, drying and annealing. Annealing was performed at 175 degreeC for about 1 hour. A nickel plated layer of 1 µm or more was formed on the surface of the product. Products having plated layers and enlarged photographs of the surfaces thereof are shown in FIGS. 4 and 5, respectively.

As a result of testing the adhesion of the film, it showed strong resistance to adhesive tape or awl scratch. In addition, conductivity was confirmed in electrical conductivity. For the electromagnetic shielding experiment, it was applied to the Infrared Receiver Module to check the blocking of the reception noise and showed the same characteristics as the existing metal case.

Example 2.

The same procedure was followed as in Example 1 except that the pretreated structure was plated with black nickel. Black nickel plating was performed on the surface of the product, and the same result as shown in FIG. 6 was obtained.

Comparative Example 1

The same procedure as in Example 1 was conducted except that the alumina particles were used alone. There was no nickel plating on the surface of the product.

1 is a photograph of the EMC molding structure of the remote control receiving module having a light receiving window.

FIG. 2 is a microscope 500x magnification surface image of the surface of an EMC molding structure prior to catalyst particle injection.

3 is a photograph of the surface of the microscope 500 times the surface of the EMC molding structure after the catalyst particle injection.

Figure 4 is a photograph of the nickel-plated molding around the particles seated on the surface of the EMC molding except the light receiving window according to the embodiment of the present invention.

5 is a surface photograph of the surface of the EMC molding structure after nickel plating according to an embodiment of the present invention at a microscope ratio of 500 times.

FIG. 6 is a photograph of a molding in which black nickel is plated around particles deposited on a surface of an EMC molding except for a light receiving window according to another embodiment of the present invention.

Claims (21)

Electroless plating method characterized in that the plating by fixing the catalyst particles to the member to be plated. The electroless plating method according to claim 1, wherein at least a part of the catalyst particles are inserted into and fixed to the surface of the member to be plated. The electroless plating method according to claim 1 or 2, wherein the catalyst particles have an average particle diameter of 1 to 100 m. The electroless plating method according to claim 1 or 2, wherein the catalyst particles are fixed by spraying the catalyst particles onto the member to be plated. 5. The method of claim 4, wherein the catalyst particles are dry sprayed and fixed. The electroless plating method according to claim 1 or 2, wherein the catalyst particles are particles containing an electroless plating catalyst component. The electroless plating method according to claim 1 or 2, wherein the catalyst particles are particles comprising a mixture of silicon, nickel, palladium, gold, silver, platinum, graphite, and copper. The electroless plating method according to claim 1 or 2, wherein the catalyst particles are silicon particles. 6. The electroless plating method of claim 5, wherein the catalyst particles are injected at a pressure of 0.1-3.0 kg _f / cm 2. The electroless plating method according to claim 1, wherein the member to be plated is plastic, wood, or ceramic. Member to be plated; Catalyst particles fixed to the plated member; And an electroless plating layer. 12. The plated body according to claim 11, wherein at least a part of the catalyst particles are inserted into and fixed to the surface of the member to be plated. The plated product according to claim 11 or 12, wherein the catalyst particles have an average particle diameter of 1 to 100 µm. The plating member according to claim 11 or 12, wherein the catalyst particles are fixed by injecting the catalyst particles onto the member to be plated. The plating body according to claim 14, wherein the catalyst particles are fixed by dry spraying. The plated body according to claim 11 or 12, which is a particle containing the electroless plating catalyst component. The plating body according to claim 11 or 12, wherein the catalyst particles are particles including silicon, nickel, palladium, gold, silver, platinum, graphite, copper, and mixtures thereof. The plating body according to claim 17, wherein the catalyst particles are silicon particles. The plated body according to claim 11 or 12, wherein the plated member is an encapsulant or a substrate. The electroless plating pretreatment method characterized by spraying and fixing an electroless plating catalyst particle to a to-be-plated member. Electroless plating catalyst particles of 1-100 μm average particle size selected from the group consisting of silicon, nickel, palladium, gold, silver, platinum, graphite, copper and one or more mixtures thereof.

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