CN104911568A - Selective chemical plating method - Google Patents

Abstract

The invention discloses a method for selective chemical plating, which belongs to the technical field of chemical plating. The preparation method comprises: (a) pretreatment of substrate materials; (b) selective printing of a transition layer on the surface of the substrate and drying; (c) sensitive Chemicalization and activation of the substrate printed with a transition layer; (d) electroless plating to obtain plated parts. The selective electroless plating method provided by the invention has simple technological process, low cost, good selectivity and ensures the precision of the electroless plating pattern.

Description

A method of selective electroless plating

technical field

The invention belongs to the field of chemical plating, and in particular relates to a selective chemical plating method.

Background technique

The electroless plating method is a self-catalytic process that does not need to provide current. It deposits metal on the surface of the substrate through oxidation-reduction. The prepared coating has good electrical and thermal conductivity, and its cost is low. The equipment can also be applied to materials with complex shapes.

At present, with the development of electronic technology and network technology, high-precision selective electroless plating technology is required in some fields such as selective shielding and microelectronic devices. Therefore, the development of a selective electroless plating method suitable for various substrates, simple in process and environmentally friendly has received extensive attention. For example, patent 200810141987.3 discloses a plastic composition and its surface selective metallization process. This method uses a laser to etch the plastic surface, then soaks it in a salt solution containing metal ions, and finally performs metal electroless plating. Patent 200810142571.3 discloses a selective electroless plating method for plastic substrates. In this method, nano-metal paste is first coated on the substrate, followed by laser etching, and finally chemical coating. Both of these two methods use laser etching to prepare patterns, which not only have high cost and difficult operation, but also have relatively high requirements on the substrate, and both have obvious technical differences from the patent of the present invention. Another example is patent 201080027204.4 which discloses a selective deposition method of metal on a plastic substrate, but this patent has obvious technical differences from the patent of the present invention. The method involves sulfonating a plastic article, activating the sulfonated plastic article to receive plating thereon. This method is only suitable for plastic substrates, and involves sulfonation reactions, which is not environmentally friendly. Another example is patent 201410125969.1 which discloses a method for selective silver plating on highly filled stone paper. This method includes pattern printing and chemical silver plating on the surface of high-fill stone paper, which is only applicable to stone paper substrates and chemical silver plating, and has essential differences from the present invention.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings of the existing selective chemical plating method, and provide a selective chemical plating method suitable for various substrates, simple in process and environmentally friendly.

In order to solve the above technical problems, the technical solution adopted is:

A method for selective electroless plating, in which a transition layer of a certain pattern is printed on the surface of a base material, wherein the part printed with the transition layer can absorb a catalyst and perform electroless plating, and the method comprises the following steps:

(1) Pre-treatment of the base material: soak the base material in 1% NaOH solution at 50-60°C for 1-5 minutes to remove oil, then clean the base material with deionized water, and finally put it in the oven Dry at 50-80°C for 1-10 minutes for later use;

(2) Print a transition layer with a certain pattern on the surface of the substrate, with a thickness of 1-500 microns, and dry it at 80°C for 10 minutes;

(3) sensitizing the substrate obtained in step (2) by immersing it in a sensitizing solution with a pH of 1 to 3, and sensitizing at 30-80° C. for 1 to 90 minutes;

(4) immerse the substrate obtained in step (3) into an activation solution with a pH of 1-4 for activation, and activate at 30-80°C for 1-60 minutes;

(5) Wash the substrate obtained in step (4) in ionized water, dry at 60° C. for 10 minutes after electroless plating, and obtain a plated part.

Among them, the base materials are ceramics, polyethylene, polypropylene, polyethylene terephthalate, polyvinyl alcohol, plastics, polystyrene, polymethyl methacrylate, polycarbonate and polyethylene naphthalate. At least one of alcohol esters, etc.; the transition layer is a polymer latex containing active groups such as carboxyl, amino, isocyanate and methylol, containing acrylic acid, methacrylic acid, maleic acid, methyl methacrylate, methyl acrylate At least one of ester, butyl acrylate, polyacrylate copolymer emulsion of acrylonitrile and/or styrene, carboxy-modified styrene-butadiene latex, polycarbonate resin, epoxy resin, phenolic resin, water-based polyurethane, etc.; sensitive The activating solution is stannous chloride; the activating solution contains a metal colloid catalyst, and wherein the metal colloid catalyst is at least one of palladium, platinum, silver and gold.

The above-mentioned transition layer printing method is at least one of spray coating, roll coating, printing, screen printing, doctor blade coating, immersion plating, gravure printing and spin coating.

The electroless plating in the above step (5) includes at least one of electroless copper plating, electroless nickel plating and electroless silver plating.

In the present invention, only the selectively printed transition layer can be sensitized and activated to absorb the metal colloid catalyst, and chemical coating can be carried out in the chemical plating solution, so the precision of the chemical plating is very high.

The beneficial effects of the present invention are: 1, the preparation method adopted in the present invention can reduce the cost of selective electroless plating; 2, the preparation method adopted in the present invention can realize continuous production; 4. The preparation process is simple, easy to control, low energy consumption, and environmentally friendly.

Description of drawings

Fig. 1 is a schematic diagram of the three-layer structure of the present invention.

Fig. 2 is the schematic diagram of selective electroless copper plating on the polyethylene film surface of the present invention

In the drawings: 1. Base material; 2. Transition layer; 3. Electroless plating coating layer.

Detailed ways

The present invention is specifically described below by way of examples. It is necessary to point out that the following examples are only used to further illustrate the present invention, and cannot be interpreted as limiting the protection scope of the present invention. Those skilled in the art make some non-essential improvements and adjustments to the present invention according to the above-mentioned content of the present invention , are considered within the protection scope of the present invention.

Example 1

Soak the polyethylene naphthalate substrate in a 1% NaOH solution at 55°C for 2 minutes to remove oil, and degrease the polyethylene naphthalate substrate with deionized water Clean it up and dry it in an oven at 60°C for 2 minutes. Use the printing process to print a butyl acrylate film with a certain pattern on the surface of the substrate, with a thickness of 30 microns, and dry it at 80°C for 10 minutes; immerse the substrate printed with the butyl acrylate film in a stannous chloride solution with a pH of 2. Sensitization, sensitization at 30°C for 6 minutes; next, immerse the sensitized substrate in a silver chloride solution with a pH of 2.5 for activation, and activate at 50°C for 4 minutes; take it out, wash it with deionized water and dry it for later use.

Preparation of electroless nickel plating bath, the bath components are: NiSO ₄ 7H ₂ O (50 grams/liter), NaH ₂ PO ₂ H ₂ O (25 grams/liter), (NH ₄ ) ₂ SO ₄ ( 11 g/l), C ₆ H ₈ O ₇ (7 g/l). Immerse the activated substrate in an electroless nickel plating solution at 55°C for 5 minutes. After electroless nickel plating, wash with deionized water, and dry in an oven at 60° C. for 10 minutes to obtain an electroless nickel-plated part on the polycarbonate substrate, wherein only the part printed with the acrylic film is electrolessly plated with nickel.

Example 2:

Soak the polyethylene terephthalate substrate in a 1% NaOH solution at 50°C for 5 minutes to remove oil, and degrease the polyethylene terephthalate substrate with deionized water. The alcohol ester was cleaned and dried in an oven at 50°C for 10 minutes. A certain pattern of methyl methacrylate coating is printed on the surface of the substrate by flat screen printing process, with a thickness of 1 micron, and dried at 80°C for 10 minutes; the substrate printed with methyl methacrylate film is immersed in a pH of 3 Sensitize in a stannous chloride solution, sensitize for 1 minute at 30°C; then immerse the sensitized substrate in a palladium chloride solution with a pH of 4 for activation, and activate for 1 minute at 80°C; take it out with a deionized Rinse with water and dry for later use.

An electroless silver plating bath was prepared, and the bath components were: AgNO ₃ (29 g/liter), NH ₃ ·H ₂ O (4 g/liter), and HCHO (55 g/liter). Immerse the activated substrate in an electroless silver plating solution at 45° C. for 10 minutes. After electroless silver plating, wash with deionized water and dry in an oven at 60°C for 10 minutes to obtain selective electroless silver plating samples on polyethylene terephthalate substrates, in which only methyl methacrylate is printed. Portions of the coating are electrolessly plated with silver.

Example 3:

Soak the polyethylene film substrate in a 1% NaOH solution at 60°C for 1 minute to remove oil, then clean the polyethylene film after degreasing with deionized water, and place it in an oven at 80°C Let dry for 1 minute. Print a certain pattern of acrylic coating on the surface of the substrate by scrape coating, with a thickness of 500 microns, and dry it at 80°C for 10 minutes; immerse the substrate printed with the acrylic film in a stannous chloride solution with a pH of 1 for sensitization Sensitization, sensitization at 80°C for 90 minutes; next, immerse the sensitized substrate in a palladium chloride solution with a pH of 1 for activation, and activate at 80°C for 60 minutes; take it out, wash it with deionized water and dry it for later use.

Preparation of electroless copper plating bath, bath components are: _{NiSO 7H 2 O} (1 gram/liter), CuSO 5H ₂ O (24 grams/liter), NaH ₂ PO ₂ H ₂ O ₍ 55 grams /L), Na ₃ C ₆ H ₅ O ₇ ·2H ₂ O (1.5 g/L), H ₃ BO ₃ (70 g/L). The activated substrate is immersed in an electroless copper plating solution at 40° C. for 5 minutes. After the electroless copper plating, wash with deionized water, and dry at 60° C. for 10 minutes in an oven to obtain the electroless copper plating sample on the polyethylene film substrate, wherein only the polyethylene film surface area printed with an acrylic coating forms a copper film ( as shown in picture 2).

Claims (6)

1. a method for selective chemical plating, is characterized in that: described method comprises following steps:

(1) be under 50-60 DEG C of condition, soak 1-5 minute in 1%NaOH solution with oil removing by body material at massfraction, then after base material being cleaned up with deionized water, finally in an oven under 50-80 DEG C of condition dry 1-10 minute for subsequent use;

(2) matrix surface after cleaning prints the transition layer of certain pattern, and thickness is 1 ~ 500 micron, to be placed under the condition of 80 DEG C dry 10 minutes;

(3) step (2) gained matrix is immersed pH and carry out sensitization in the sensitizing solution of 1 ~ 3, sensitizing temperature is 30-80 DEG C, and sensitization time is 1 ~ 90 minute;

(4) step (3) gained matrix is immersed pH to activate in the activation solution of 1-4, activation temperature is 30-80 DEG C, and soak time is 1 ~ 60 minute;

(5) step (4) gained matrix is cleaned in deionized water, 60 DEG C of dryings 10 minutes after electroless plating, obtain plating piece.

2. the method for a kind of selective chemical plating according to claim 1, is characterized in that: the body material in described step (1) is at least one in pottery, polyethylene terephthalate, polyvinyl alcohol, nylon, polystyrene, polyethylene, polypropylene, polymethylmethacrylate, polycarbonate and PEN.

3. the method for a kind of selective chemical plating according to claim 1, it is characterized in that: the transition layer in described step (2) is containing the polymer emulsion of active group as carboxyl, amino, isocyanic ester and methylol, containing vinylformic acid, methacrylic acid, toxilic acid, methyl methacrylate, methyl acrylate, butyl acrylate, vinyl cyanide and/or cinnamic acrylate copolymer emulsion, carboxy-modified styrene-butadiene latex, polycarbonate resin, at least one in epoxy resin, resol, aqueous polyurethane.

4. the method for a kind of selective chemical plating according to claim 1, is characterized in that: the transition layer printing method in described step (2) is at least one in spraying, roller coating, printing, silk screen printing, blade coating, immersion plating, intaglio printing and spin coating.

5. the method for a kind of selective chemical plating according to claim 1, it is characterized in that: in described step (3), sensitizing solution is stannous chloride solution, activation solution comprises metallic colloid catalyzer, and wherein said metallic colloid catalyzer is at least one in palladium, platinum, silver and gold.

6. the method for a kind of selective chemical plating according to claim 1, is characterized in that: in described step (5), electroless plating comprises at least one in electroless copper, chemical nickel plating and chemical silvering.