CN103525154B - A kind of ionic metal coating for the pre-treatment of plastic substrate chemical plating copper and technique - Google Patents

Abstract

An ionic metal paint and process for the pretreatment of chemical copper plating on plastic substrates. The present invention relates to a paint used for surface treatment of plastic substrates and a method for surface treatment thereof. The present invention aims to solve the problem of using paint to coat The technical problems of electroless copper plating difficulty, low binding force between copper layer and paint layer and poor uniformity of paint layer are the methods for making the surface of plastic workpiece have catalytic activity. The coating is obtained by mixing biological binder solution, metal salt, metal complexing agent, wetting agent and deionized water, and adjusting the pH of the solution to 6-9 with a pH regulator. Pre-treatment process: After chemical degreasing treatment on the surface of the plastic substrate, the ionic metal coating is applied to the surface of the plastic substrate, and then dried at low temperature to obtain a coating with a dry film thickness of 0.1 to 1 micron, and the chemical plating of the plastic substrate is completed. The pretreatment of copper, the method starts plating quickly, and the coating is uniform, and can be used in the field of chemical plating.

Description

A kind of ionic metal coating and process for the pretreatment of electroless copper plating on plastic substrate

technical field

The invention relates to a coating used for surface treatment of plastic substrates and a surface treatment method thereof, in particular to a coating used for pretreatment of chemical copper plating on the surface of plastic substrates and a process for using the same to perform pretreatment of electroless copper plating.

Background technique

Plastic has many advantages such as high impact strength, corrosion resistance, good processing formability, and light weight. After metallization, plastic can have many advantages such as electrical conductivity, thermal conductivity, magnetic conductivity, decoration, and weldability. At present, plastic metallization mainly includes copper plating, nickel plating, silver plating, gold plating, palladium plating and so on. The application of plastic copper plating involves many fields such as engineering plastics, printed boards, and electronic plating. Plastic copper plating mainly includes physical and chemical methods. Physical methods such as ion sputtering and other equipment are expensive, have problems with bonding, and have size requirements for processing workpieces. The chemical method is not affected by these, and the chemical method mainly includes direct plastic plating and electroless plating. Electroless plating, also called electroless plating, is a self-catalyzed chemical reaction process that does not require an external power supply. It is a process that uses a reducing agent in the plating solution to reduce metal ions. The substrate of electroless plating needs to be catalytically active, that is, the surface of the workpiece must have metal-inducing substances that can oxidize and reduce agents. Therefore, the key to realizing electroless copper plating on plastic workpieces is to make the surface of plastic workpieces have catalytic activity in the pretreatment. Wherein the method of adopting the paint coating method to make the surface of the plastic workpiece have catalytic activity is to coat the paint on the surface of the plastic workpiece after treatment, so that the surface of the workpiece has catalytic activity. Mix it with polyurethane resin to make a coating activation solution, coat it on the surface of the plastic workpiece, bake it at a temperature of 150-200°C, and then electroless copper plating. However, the problem with this method is that the surface of the coating is hydrophobic after drying, and the electroless copper plating solution is an aqueous solution. Due to the existence of interfacial tension, it will inevitably affect the initiation of electroless copper plating; Introduction, because the resin adhesive has a different thermal expansion coefficient from the substrate, it will reduce the bonding force between the copper layer and the paint layer, and it is not suitable for materials such as printed boards or optical materials that require strict thermal expansion coefficients or stability. Law. The Chinese patent application number 201110314195.3 proposes to coat the surface of the organic non-conductive substrate with a conductive paint, then bake and cure, then take mechanical polishing to destroy the hydrophobicity to expose the active points, and then electroless copper plating. In this method, the method of exposing active points by mechanical polishing is difficult to control the uniformity of polishing, especially for irregular workpieces.

Contents of the invention

The present invention aims to solve the technical problems of difficulty in starting electroless copper plating, low bonding force between the copper layer and the coating layer and poor uniformity of the coating layer in the existing method of using a paint coating method to make the surface of a plastic workpiece have catalytic activity. The invention provides an ionic metal coating and a process for the pretreatment of electroless copper plating on a plastic substrate.

A kind of ionic metal coating used for the pretreatment of electroless copper plating on plastic substrates of the present invention consists of 5-20 parts of biological binder solution, 0.01-5 parts of metal salt, and 1-10 parts of metal complex Mixture, 0.1-1 part of wetting agent and 65-90 parts of deionized water are mixed, and then the pH of the solution is adjusted to 6-9 with a pH regulator;

Wherein the bio-binder solution is composed of 0.5-15 parts by weight of bio-binder monomer, 0.1-5 parts of oxidizing agent, 0.5-5 parts of pH buffering agent, and 0.1-1 part of silane Made of coupling agent and 75-95 parts of deionized water;

Wherein the biological binder monomer is dopamine hydrochloride, norepinephrine, 5-hydroxydopamine, droxidopa, α-methyldopamine, dexdopa, levodopa, α-methyldopa and nitrate One or a combination of several dopamines;

The above-mentioned preparation method of the ionic metal coating used for the pretreatment of electroless copper plating on plastic substrates is carried out in the following steps:

1. Weigh 5 to 20 parts of biological binder solution, 0.01 to 5 parts of metal salt, 1 to 10 parts of metal complexing agent, 0.1 to 1 part of wetting agent and 65 to 90 parts by weight. parts of deionized water;

2. Pour 2/3 of deionized water into the container, add metal complexing agent and stir until dissolved;

3. In the state of stirring, add the metal salt into the container, and after it dissolves, add the bio-binder solution;

4. In the state of stirring, add the wetting agent into the container, after stirring evenly, pour the remaining deionized water into the container, and then stir evenly;

5. In the state of stirring, add a pH regulator to adjust the pH to 6-9, and continue stirring for 12 hours to obtain an ionic metal coating for pretreatment of electroless copper plating on a plastic substrate.

Utilize the above-mentioned ionic metal paint for plastic substrate electroless copper plating pretreatment to carry out the technology of plastic substrate electroless copper plating pretreatment, specifically carry out as follows:

1. Chemical degreasing treatment on the surface of the plastic substrate;

The plastic matrix used is general-purpose engineering plastic or printed circuit board substrate, and the engineering plastic is acrylonitrile-butadiene-styrene plastic (ABS) plastic, polyimide (PI) plastic, polyethylene terephthalate Ester (PET); printed circuit board base material is epoxy resin glass fiber board (FR-4), polyimide film (PI), polyethylene terephthalate (PET) film;

The chemical degreasing treatment is specifically to immerse the surface of the plastic substrate in a chemical degreasing solution at 60-80°C for 3-5 minutes; the chemical degreasing solution is 30-60g/L sodium hydroxide, 15-30g/L carbonic acid A solution obtained by adding one or more of sodium and 20-35g/L trisodium phosphate into water;

2. Apply the ionic metal coating used for the pretreatment of plastic substrate electroless copper plating on the surface of the plastic substrate treated in step 1, and then dry it at a temperature of 25-65°C for 0.5-5min, and then apply it on the surface of the plastic substrate A coating with a dry film thickness of 0.1 to 1 micron is obtained, and the pretreatment of electroless copper plating on the plastic substrate is completed.

Advantage of the present invention is embodied in the following points:

1. Strong versatility, good combination with various plastic substrates. The coatings described in this process employ bio-adhesives containing catechol structures derived from biological mussel mussel mucus that can adhere to almost any plastic substrate. Compared with the traditional ionic metal activation treatment, the force between the plating layer and the substrate treated by this process is a chemical bond rather than an anchoring effect, so the obtained electroless copper plating layer has a high bonding force.

2. The process is simple.

1) Compared with the coating process of catalytic coating, the coating dry film thickness is at the nanometer level, no high-temperature sintering is required, and only low-temperature short-term drying is required;

2) Compared with the process of coating catalytic coating, the surface is still hydrophilic after drying, so there is no need for post-treatment (such as polishing) to expose catalytic active points, there is no interfacial tension problem with the electroless copper plating solution, and the coating layer is uniform. It is easy to start plating and is also suitable for plastic substrates with irregular shapes.

3) Compared with the traditional activation solution process, there is no chemical roughening step, which avoids the use of roughening solution that is harmful to the environment, and is environmentally friendly;

4) No chemical reduction step. Compared with the traditional ionic metal activation method, the step of reducing with a reducing agent to obtain electroless plating catalytic particles is omitted, but the reducing agent in the electroless copper plating solution is directly used to generate catalytic metal particles, and then the electroless plating process is continuously catalyzed to achieve copper plating.

3. Good stability.

Compared with the catalytic solution used in the traditional plastic adsorption method and coating coating method, metal ions exist in the ionic state in the coating, and the metal can bond with the catechol structure and nitrogen atom in the bioadhesive, so the described The ionic metal coating is very stable.

In a word, the ionic metal coating used for pretreatment of plastic substrate electroless copper plating of the present invention has wide versatility to plastic substrate, has good binding force with plastic substrate, and good stability; Hydrophilicity is strong, and metal exists in ionic state, No need for high-temperature sintering, only need low-temperature short-term drying to have good catalytic performance and the surface after coating is completely hydrophilic, there is no interfacial tension problem; it is not limited by the shape of the substrate. The plastic substrate only needs steps such as degreasing, coating, and low-temperature short-time drying to carry out electroless plating, which can save the traditional chemical roughening, the whole treatment process is simple, and is environmentally friendly; the self-reducing agent of the electroless plating solution is directly used For reduction, there is no need to increase the reduction step like the previous ionic metal activation solution. By means of the method, an electroless copper-plated metal coating with good binding force and good appearance can be obtained on the surface of the plastic base body through a simple, cheap and environment-friendly process.

Description of drawings

Fig. 1 is the 400 times optical microscope photo of the copper layer on the surface of embodiment 1PI plastic test piece;

Fig. 2 is the 400 times optical microscope photo of the copper layer on the surface of the epoxy resin fiberglass board FR-4 of embodiment 2;

Fig. 3 is the 400 times optical microscope photo of the copper layer on the ABS plastic plate surface of embodiment 3;

Fig. 4 is the 400 times optical microscope photograph of the copper layer on the surface of the PET plastic plate of embodiment 4.

Detailed ways

Specific embodiment one: a kind of ionic metal paint that is used for the pretreatment of electroless copper plating of plastic substrate according to the present embodiment consists of 5～20 parts of biological binder solution, 0.01～5 parts of metal salt, 1 It is obtained by mixing ~10 parts of metal complexing agent, 0.1~1 part of wetting agent and 65~90 parts of deionized water, and then adjusting the pH of the solution to 6~9 with a pH regulator; bioadhesive solution It is composed of 0.5-15 parts of biological binder monomer, 0.1-5 parts of oxidizing agent, 0.5-5 parts of pH buffer agent, 0.1-1 part of silane coupling agent and 75-95 parts of Made of deionized water; the biobinder monomers are dopamine hydrochloride, norepinephrine, 5-hydroxydopamine, droxidopa, α-methyldopamine, dexodopa, levodopa, α- One or a combination of methyldopa and nitrodopamine.

The bioadhesive monomers of this embodiment all have a catechol structure.

Specific embodiment two: the difference between this embodiment and specific embodiment one is that the oxidizing agent in the biological binder solution is one or more of sodium hypochlorite, potassium permanganate, oxygen, ammonium persulfate and sodium peroxide Combination; others are the same as in Embodiment 1.

When the oxidizing agent is a composition, each oxidizing agent is combined in any ratio.

Specific embodiment three: this embodiment is different from specific embodiment one or two in that the pH buffering agent in the bio-binder solution is borax, sodium acetate, tris hydrochloride or sodium dihydrogen phosphate; others are the same as specific embodiment one or two the same.

Embodiment 4: The difference between this embodiment and one of Embodiments 1 to 3 is that the silane coupling agent in the bio-binder solution is one of KH550, KH792, KH560 and KH602 or a combination of several of them; One of the specific embodiments 1 to 3 is the same.

When a silane coupling agent is a composition, each silane coupling agent is combined in arbitrary ratios.

The main function of silane coupling agent is to improve the bonding force with the matrix.

Embodiment 5: This embodiment differs from Embodiment 1 to Embodiment 4 in that the preparation method of the bio-binder solution is as follows:

a. Weigh 0.5 to 15 parts of bioadhesive monomer, 0.1 to 5 parts of oxidizing agent, 0.5 to 5 parts of pH buffer, 0.1 to 1 part of silane coupling agent and 75 to 95 parts by weight. parts of deionized water;

b. Pour 2/3 of deionized water into an airtight container, add pH buffer and stir until dissolved, then add bio-binder monomer, stir until all monomer is dissolved;

c. Under stirring, add the oxidizing agent into the airtight container, then raise the temperature from normal temperature to 45-50°C and keep the reaction for 20-24h;

d. Add the silane coupling agent into the airtight container, continue to react at 45-50°C for 20-24 hours;

e. Pour the remaining deionized water into an airtight container and stir evenly to obtain a bio-binder solution.

Others are the same as one of the specific embodiments 1 to 4.

Embodiment 6: The difference between this embodiment and one of Embodiments 1 to 5 is that the metal salt is palladium salt, silver salt, nickel salt or copper salt; others are the same as Embodiments 1 to 5.

Embodiment 7: This embodiment differs from Embodiment 6 in that the palladium salt is one or a combination of palladium chloride, palladium sulfate and palladium acetate; the others are the same as Embodiment 6.

In the present embodiment, when the palladium salt is a composition, various palladium salts are combined in any ratio.

Embodiment 8: This embodiment differs from Embodiment 6 in that the silver salt is one of silver nitrate, silver fluoride, and silver perchlorate or a combination of several of them; others are the same as Embodiment 6. same.

In the present embodiment, when the silver salt is a composition, various silver salts are combined in any ratio.

Specific embodiment nine: the difference between this embodiment and specific embodiment six is that the nickel salt is one or several of nickel chloride, nickel sulfamate, nickel sulfate, nickel acetate and basic nickel carbonate combination; others are the same as in Embodiment 6.

In the present embodiment, when the nickel salt is a composition, various nickel salts are combined in any ratio.

Embodiment 10: The difference between this embodiment and Embodiment 6 is that the copper salt is one of copper sulfate, copper nitrate and copper chloride or a combination of several of them; the others are the same as Embodiment 6.

In the present embodiment, when the copper salt is a composition, various copper salts are combined in any ratio.

Embodiment 11: This embodiment is different from Embodiment 1 to Embodiment 11 in that the metal complexing agent is ethanolamine, ethylenediamine, sodium edetate and N,N,N'N'-tetrakis(2 One of - hydroxypropyl) ethylenediamine or a combination of several of them; the others are the same as in the specific embodiment one to one ten.

In the present embodiment, when the metal complexing agent is a composition, each metal complexing agent is combined in any ratio.

Embodiment 12: This embodiment is different from Embodiment 1 to Embodiment 11 in that the wetting agent is one of sodium lauryl sulfate, sodium lauryl sulfate and sodium cetyl sulfate one or a combination of several of them; the others are the same as in one of the specific embodiments 1 to 11.

In the present embodiment, when the wetting agent is a composition, each wetting agent is combined in any ratio.

Embodiment thirteen: This embodiment is different from Embodiment 1 to Embodiment 12 in that the pH regulator is ammonia water, hydrochloric acid or sulfuric acid; others are the same as Embodiment 1 to Embodiment 12.

Specific embodiment fourteen: the preparation method of the ionic metal coating that is used for plastic substrate electroless copper plating pretreatment described in specific embodiment one carries out according to the following steps:

1. Weigh 5 to 20 parts of biological binder solution, 0.01 to 5 parts of metal salt, 1 to 10 parts of metal complexing agent, 0.1 to 1 part of wetting agent and 65 to 90 parts by weight. parts of deionized water;

2. Pour 2/3 of deionized water into the container, add metal complexing agent and stir until dissolved;

3. In the state of stirring, add the metal salt into the container, and after it dissolves, add the bio-binder solution;

4. In the state of stirring, add the wetting agent into the container, after stirring evenly, pour the remaining deionized water into the container, and then stir evenly;

5. In the state of stirring, add a pH regulator to adjust the pH to 6-9, and continue stirring for 12 hours to obtain an ionic metal coating for pretreatment of electroless copper plating on a plastic substrate.

Embodiment 15: Utilize the ionic metal coating for plastic substrate electroless copper plating pretreatment described in embodiment one to carry out the process of plastic substrate electroless copper plating pretreatment, specifically carry out according to the following steps:

1. Chemical degreasing treatment on the surface of the plastic substrate;

2. Apply the ionic metal coating used for the pretreatment of plastic substrate electroless copper plating on the surface of the plastic substrate treated in step 1, and then dry it at a temperature of 25-65°C for 0.5-5min, and then apply it on the surface of the plastic substrate A coating with a dry film thickness of 0.1 to 1 micron is obtained, and the pretreatment of electroless copper plating on the plastic substrate is completed.

Embodiment 16: The difference between this embodiment and Embodiment 15 is that the plastic base is a common engineering plastic or a printed circuit board substrate. Others are the same as in the fifteenth embodiment.

Embodiment 17: This embodiment is different from Embodiment 15 or 16 in that the engineering plastics are acrylonitrile-butadiene-styrene plastic (ABS) plastic, polyimide (PI) plastic, poly Ethylene phthalate (PET); printed circuit board base material is epoxy resin glass fiber board (FR-4), polyimide film (PI), polyethylene terephthalate (PET) film. Others are the same as those in Embodiment 15 or 16.

Embodiment 18: The difference between this embodiment and Embodiment 15 or 16 is that the chemical degreasing treatment is specifically immersing the surface of the plastic substrate in a chemical degreasing solution at 60-80°C for 3-5 minutes; The oil removal solution is a solution obtained by adding one or more of 30-60g/L sodium hydroxide, 15-30g/L sodium carbonate and 20-35g/L trisodium phosphate into water. Others are the same as those in Embodiment 15 or 16.

Verify beneficial effect of the present invention with following example:

Example 1 The test process of this embodiment 1 is as follows:

One, prepare dopamine biological binder solution, its preparation method is as follows:

a, take by weight 5.5 parts of dopamine hydrochloride, 3 parts of ammonium persulfate, 1 part of tris hydrochloride, 0.5 parts of silane coupling agent KH550 and 90 parts of deionized water;

b. Pour 2/3 of deionized water into an airtight container, add tris hydrochloride and stir until dissolved, then add dopamine hydrochloride, and stir until dopamine hydrochloride is completely dissolved;

c. Under stirring, add ammonium persulfate into the airtight container, then raise the temperature from normal temperature to 50°C and keep the reaction for 24h;

d. Add the silane coupling agent KH550 into the airtight container, continue to react at 50°C for 24 hours;

e. Pour the remaining deionized water into an airtight container and stir evenly to obtain a dopamine bio-binder solution.

Two, utilize the dopamine bio-adhesive solution synthesized in step one to prepare the ionic metal coating for plastic substrate electroless copper plating pretreatment, and concrete preparation method is as follows:

f, take by weight 10 parts of dopamine bioadhesive solution, 0.05 parts of palladium chloride, 5 parts of sodium edetate, 0.1 part of sodium lauryl sulfate and 84 parts of Ionized water;

g. Pour 2/3 of the deionized water into the container, add metal complexing agent sodium edetate and stir until dissolved;

h, under stirring state, palladium chloride is added in the container, after dissolving, add dopamine bioadhesive agent solution;

i. In the stirring state, add sodium lauryl sulfate into the container, after stirring evenly, pour the remaining deionized water into the container, and then stir evenly;

j. In the stirring state, add ammonia water, adjust the pH to 8, and continue stirring for 12 hours to obtain a palladium ion metal coating for the pretreatment of electroless copper plating on the plastic substrate.

Three, carry out the special-purpose PI plastic substrate electroless copper plating pretreatment of flexible printed board with the palladium ion metal coating that is used for the plastic substrate electroless copper plating pretreatment that step 2 synthesizes, and its specific process steps are as follows:

k. Cut PI plastic for flexible printed boards into 2×2cm ² test pieces with a thickness of 0.1cm, put them in a chemical degreasing solution, and soak them for 4 minutes at a temperature of 65°C; take them out and wash them with distilled water. Blow dry; wherein the chemical degreasing solution is obtained after adding 40g/L sodium hydroxide and 25g/L sodium carbonate into water;

l. Immerse the PI plastic treated in step 1 in the palladium ion metal coating used for the pretreatment of electroless copper plating on the plastic substrate for 2 minutes, then take out the sample and dry it at 50°C for 2 minutes to obtain a dry film thickness of 0.5 Micron PI plastic test piece with ionic palladium coating layer; (can be determined by X-ray fluorescence spectrometry, palladium is selected as the internal standard element, and the thickness-palladium content standard curve is established)

Four, carry out electroless copper plating on the PI plastic test piece that step 3 prepares, specifically as follows:

m. The concentration of copper sulfate is 0.04mol/L, the concentration of potassium sodium tartrate is 0.2mol/L, the concentration of sodium hydroxide is 0.25mol/L, the concentration of 37% formaldehyde is 10mL/L, and 2-mercaptobenzene The concentration of thiazole is 0.2 mg/L. Copper sulfate, potassium sodium tartrate, sodium hydroxide, 37wt% formaldehyde and 2-mercaptobenzothiazole are added to deionized water, and stirred evenly to obtain an electroless copper plating solution;

n. Put the PI plastic test piece into the electroless copper plating solution at 40°C and apply plating for 1 hour to obtain a copper layer on the surface of the PI plastic test piece to complete the electroless copper plating.

In step 3, the dry film thickness is measured by X-ray fluorescence spectrometry, and palladium is selected as an internal standard element, and a thickness-palladium content standard curve is established, and then according to the palladium content of the dry film, the dry film thickness is calculated.

The deposition rate of electroless copper plating in step 4 is 2-3 μm/h.

Coating deposition speed is 1-3μm/h.

Example 2 The test process of this embodiment 2 is as follows:

One, prepare levodopa biological binder solution, its preparation method is as follows:

a, take by weight 5 parts of levodopa, 2 parts of sodium hypochlorite, 2 parts of borax, 1 part of silane coupling agent KH560 and 90 parts of deionized water;

b. Pour 2/3 of deionized water into an airtight container, add borax and stir until dissolved, then add levodopa, and stir until levodopa is completely dissolved;

c. Under stirring, add sodium hypochlorite into the airtight container, after the sodium hypochlorite dissolves, raise the temperature from normal temperature to 50°C and keep the reaction for 24h;

d. Add the silane coupling agent KH560 into the airtight container, continue to react at 50°C for 24 hours;

e. Pour the remaining deionized water into an airtight container and stir evenly to obtain a levodopa bio-binder solution.

Two, utilize the levodopa biological binder solution that step one synthesizes to prepare the ionic metal coating that is used for plastic substrate electroless copper plating pretreatment, and concrete preparation method is as follows:

f, take by weight 15 parts of levodopa biological binder solution, 0.1 part of silver nitrate, 5 parts of ethylenediamine, 1 part of sodium lauryl sulfate and 78 parts of deionized water ;

g. Pour 2/3 of the deionized water into the container, add the metal complexing agent ethylenediamine and stir until dissolved;

h, under stirring state, silver nitrate is added in the container, after to be dissolved, add levodopa biological binder solution;

i. In the stirring state, add sodium lauryl sulfate into the container, after stirring evenly, pour the remaining deionized water into the container, and then stir evenly;

j. In the stirring state, add sulfuric acid, adjust the pH to 6, and continue stirring for 12 hours to obtain a silver ion metal coating for the pretreatment of electroless copper plating on the plastic substrate.

Three, carry out rigid printed board base material epoxy resin fiberglass board FR-4 base body electroless copper plating pretreatment with the silver ion metal paint that is used for the plastic matrix electroless copper plating pretreatment that step 2 synthesizes, and its specific process steps are as follows:

k. Cut the rigid printed board substrate epoxy resin glass fiber board FR-4 into 2×2cm ² , 0.1cm thick test piece, put it into the chemical degreasing liquid, under the condition of temperature 60℃, Soak for 3 minutes; take it out, wash it with distilled water, and dry it; the chemical degreasing solution is obtained by adding 30g/L sodium hydroxide and 25g/L sodium carbonate to water;

l. Immerse the epoxy resin fiberglass board treated in step 1 in the silver ion metal coating used for the pretreatment of electroless copper plating on the plastic substrate for 2 minutes, then take out the sample, and dry it at 50°C for 2 minutes to obtain a dry Epoxy fiberglass board with ionic silver paint layer with a film thickness of 0.5 microns;

Four, carry out electroless copper plating on the epoxy resin fiberglass board prepared in step 3, specifically as follows:

m. The concentration of copper sulfate is 0.04mol/L, the concentration of potassium sodium tartrate is 0.2mol/L, the concentration of sodium hydroxide is 0.25mol/L, the concentration of 37% formaldehyde is 10mL/L, and 2-mercaptobenzene The concentration of thiazole is 0.2 mg/L. Copper sulfate, potassium sodium tartrate, sodium hydroxide, 37wt% formaldehyde and 2-mercaptobenzothiazole are added to deionized water, and stirred evenly to obtain an electroless copper plating solution;

n. Put the epoxy resin glass fiber board test piece into the electroless copper plating solution at 40°C, and apply plating for 1 hour to obtain a copper layer on the surface of the epoxy resin glass fiber board to complete the electroless copper plating.

In step 3, the dry film thickness is measured by X-ray fluorescence spectrometry, and silver is selected as an internal standard element, and a thickness-silver content standard curve is established, and then the dry film thickness is calculated according to the silver content of the dry film.

The deposition rate of electroless copper plating in step 4 is 2-3 μm/h.

Example 3 The test process of this embodiment 3 is as follows:

One, prepare 5-hydroxydopamine biological binder solution, its preparation method is as follows:

a. Take by weight 5 parts of 5-hydroxydopamine, 3 parts of potassium permanganate, 2 parts of sodium acetate, 1 part of silane coupling agent KH792 and 84 parts of deionized water;

b. Pour 2/3 of the deionized water into an airtight container, add sodium acetate and stir until dissolved, then add 5-hydroxydopamine, and stir until the 5-hydroxydopamine is completely dissolved;

c. Under stirring, add potassium permanganate into the airtight container, after the potassium permanganate is dissolved, raise the temperature from normal temperature to 50°C and keep the reaction for 24h;

d. Add the silane coupling agent KH792 into the airtight container, continue to react at 50°C for 24 hours;

e. Pour the remaining deionized water into an airtight container and stir evenly to obtain a 5-hydroxydopamine bioadhesive solution.

Two, utilize the 5-hydroxydopamine biological binder solution that step one synthesizes to prepare the ionic metal coating that is used for plastic substrate electroless copper plating pretreatment, and concrete preparation method is as follows:

f, take by weight 15 parts of 5-hydroxydopamine bioadhesive solution, 0.1 part of nickel sulfate, 5 parts of sodium edetate, 1 part of sodium cetyl sulfonate and 78 parts parts of deionized water;

g. Pour 2/3 of the deionized water into the container, add metal complexing agent sodium edetate and stir until dissolved;

h. Under stirring, add nickel sulfate into the container, and after it dissolves, add 5-hydroxydopamine biobonding

agent solution;

i. In the stirring state, add sodium cetyl sulfonate into the container, after stirring evenly, pour the remaining deionized water into the container, and then stir evenly;

j. In the state of stirring, add ammonia water, adjust the pH to 7.5, and continue stirring for 12 hours to obtain a nickel ion metal coating for pretreatment of electroless copper plating on plastic substrates.

Three, carry out the ABS plastic substrate electroless copper plating pretreatment with the nickel ion metal coating that is used for the plastic substrate electroless copper plating pretreatment that step 2 is synthesized, and its concrete process steps are as follows:

k. Cut the ABS plastic into 2×2cm ² test pieces with a thickness of 0.125cm, put them into the chemical degreasing solution, and soak them for 3 minutes at a temperature of 65°C; take them out, wash them with distilled water, and dry them; Degreasing liquid is obtained after adding 30g/L sodium hydroxide and 25g/L sodium carbonate into water;

l. Immerse the ABS plastic plate treated in step 1 in the nickel ion metal coating used for the pretreatment of plastic substrate electroless copper plating for 2 minutes, then take out the sample and dry it at 50°C for 2 minutes to obtain a dry film thickness of 0.8 micron ABS plastic plate;

Four, carry out electroless copper plating on the ABS plastic plate prepared in step 3, specifically as follows:

m, by copper sulfate 0.04mol/L, glycine 0.2mol/L, sodium hydroxide 0.25mol/L, sodium hypophosphite 0.09mol/L, 2-mercaptobenzothiazole 0.2mg/L copper sulfate, glycine, hydroxide Sodium, sodium hypophosphite and 2-mercaptobenzothiazole are added to deionized water, and stirred evenly to obtain an electroless copper plating solution;

n. Put the ABS plastic plate test piece into the electroless copper plating solution at 75°C and apply plating for 1 hour to obtain a copper layer on the surface of the ABS plastic plate to complete the electroless copper plating.

In step 3, the dry film thickness is measured by X-ray fluorescence spectrometry, nickel is selected as an internal standard element, and a thickness-nickel content standard curve is established, and then the dry film thickness is calculated according to the nickel content of the dry film.

The deposition rate of electroless copper plating in step 4 is 3-8 μm/h.

Example 4 The test process of this embodiment 4 is as follows:

One, prepare droxidopa biological binder solution, its preparation method is as follows:

a, take by weight 10 parts of droxidopa, 3 parts of ammonium persulfate, 2 parts of sodium dihydrogen phosphate, 1 part of silane coupling agent KH602 and 84 parts of deionized water;

b. Pour 2/3 of deionized water into an airtight container, add sodium dihydrogen phosphate and stir until dissolved, then add droxidopa, stir until droxidopa is completely dissolved;

c. Under stirring, add ammonium persulfate into the airtight container, after the ammonium persulfate is dissolved, raise the temperature from normal temperature to 50°C and keep the reaction for 24h;

d. Add the silane coupling agent KH602 into the airtight container, continue to react at 50°C for 24 hours;

e. Pour the remaining deionized water into an airtight container and stir evenly to obtain the droxidopa bio-binder solution.

Two, the droxidopa biological binder solution synthesized by step one is used to prepare the ionic metal coating for plastic substrate electroless copper plating pretreatment, and the specific preparation method is as follows:

f. Weigh 16 parts of droxidopa bioadhesive solution, 1 part of copper sulfate, 3 parts of N,N,N'N'-tetrakis(2-hydroxypropyl)ethylenediamine by weight , 1 part of sodium cetyl sulfonate and 78 parts of deionized water;

g. Pour 2/3 of the deionized water into the container, add the metal complexing agent N,N,N'N'-tetrakis(2-hydroxypropyl)ethylenediamine and stir until dissolved;

h, under stirring state, copper sulfate is added in the container, and after dissolving, add droxidopa biological binder solution;

i. In the stirring state, add sodium cetyl sulfonate into the container, after stirring evenly, pour the remaining deionized water into the container, and then stir evenly;

j. Under stirring state, add sulfuric acid, adjust the pH to 7, and continue stirring for 12 hours to obtain a copper ion metal coating for pretreatment of plastic substrate electroless copper plating.

Three, carry out the PET plastic substrate electroless copper plating pretreatment with the copper ion metal coating that is used for the plastic substrate electroless copper plating pretreatment that step 2 synthesizes, and its concrete process steps are as follows:

k. Cut the PET plastic into 2×2cm ² test pieces with a thickness of 0.1cm, put them in a chemical degreasing solution, soak them for 3 minutes at a temperature of 60°C; take them out, wash them with distilled water, and dry them; Degreasing liquid is obtained after adding 30g/L sodium hydroxide and 25g/L sodium carbonate into water;

l. Immerse the PET plastic plate treated in step 1 in the copper ion metal coating used for the pretreatment of chemical copper plating on the plastic substrate for 2 minutes, then take out the sample, and dry it at 50°C for 2 minutes to obtain a dry film thickness of 0.8 micron PET plastic sheet;

Four, carry out electroless copper plating on the PET plastic plate that step 3 prepares, specifically as follows:

m. The concentration of copper sulfate is 0.04mol/L, the concentration of potassium sodium tartrate is 0.2mol/L, the concentration of sodium hydroxide is 0.25mol/L, the concentration of 37% formaldehyde is 10mL/L, and 2-mercaptobenzene The concentration of thiazole is 0.2 mg/L. Copper sulfate, potassium sodium tartrate, sodium hydroxide, 37wt% formaldehyde and 2-mercaptobenzothiazole are added to deionized water, and stirred evenly to obtain an electroless copper plating solution;

n. Put the PET plastic plate test piece into the electroless copper plating solution at 40°C, apply plating for 1 hour, and obtain a copper layer on the surface of the PET plastic plate, and complete the electroless copper plating.

In step 3, the dry film thickness is measured by X-ray fluorescence spectrometry, copper is selected as an internal standard element, and a thickness-copper content standard curve is established, and then the dry film thickness is calculated according to the copper content of the dry film.

The deposition rate of electroless copper plating in step 4 is 3-8 μm/h.

Coating deposition speed is 2-3μm/h.

The appearance, binding force and electrical conductivity of the electroless copper plating layers obtained in the above four embodiments were characterized. At the same time, the centrifugal test and catalytic performance observation test were carried out on the stability of the ionic metal coating.

The appearance is observed with a 400x optical microscope to observe the uniformity and surface defects. Fig. 1 is the 400 times optical microscope photo of the copper layer on the surface of the PI plastic test piece of embodiment 1; Fig. 2 is the 400 times optical microscope photo of the copper layer on the epoxy resin fiberglass board FR-4 surface of embodiment 2; Fig. 3 is The 400 times optical microscope photograph of the copper layer on the surface of the ABS plastic plate of embodiment 3; FIG. 4 is the 400 times optical microscope photograph of the copper layer on the surface of the PET plastic plate of embodiment 4. It can be seen from Figures 1 to 4 that all the copper layers obtained are uniform and defect-free.

Bonding force adopts thermal shock test. After 10 times of thermal shock test at 100°C (25min), 0°C (5min in ice water), observe whether the coating has blisters, cracks and shedding. Judging the bonding force of copper plating.

To measure the conductivity, use a multimeter to select two points on the same side of the test piece with a distance of 1 cm to measure the resistance value. The results are shown in Table 1.

For the stability of the ionic metal coating, use a centrifuge to centrifuge at a speed of 5000 rpm for 30 minutes, and then observe whether the coating is delaminated or sedimented.

The catalytic performance of the ionic metal coating is measured by the plating time of the electroless copper plating, which is timed by a stopwatch. The shorter the time, the stronger the catalytic performance.

The measurement results of Examples 1-4 are shown in Table 1.

It can be seen from the table that the ionic metal coating is used in the pretreatment of electroless copper plating, and the obtained effect is obvious. The appearance of the coating has good bonding strength and electrical conductivity, and the coating stability and catalytic performance are also good.

Claims (10)

1. the ionic metal coating for the pre-treatment of plastic substrate chemical plating copper, after it is characterized in that this coating is mixed by the deionized water of the biological binder solution of 5 ~ 20 parts, the metal-salt of 0.01 ~ 5 part, the metal chelating agent of 1 ~ 10 part, the wetting agent of 0.1 ~ 1 part and 65 ~ 90 parts by ratio of weight and the number of copies, then with obtaining behind pH adjusting agent regulator solution pH to 6 ~ 9; Wherein biological binder solution is made up of the deionized water of the biological binding agent monomer of 0.5 ~ 15 part, the oxygenant of 0.1 ~ 5 part, the pH buffer reagent of 0.5 ~ 5 part, the silane coupling agent of 0.1 ~ 1 part and 75 ~ 95 parts by ratio of weight and the number of copies; Wherein biological binding agent monomer is a kind of or wherein several combination in dopamine hydrochloride, noradrenalin, 5-hydroxydopamine, Droxidopa, alpha-methyldopa amine, dextrorotation DOPA, levodopa, alpha-methyldopa and nitro Dopamine HCL.

2. a kind of ionic metal coating for the pre-treatment of plastic substrate chemical plating copper according to claim 1, the oxygenant that it is characterized in that in biological binder solution is a kind of or wherein several combination in clorox, potassium permanganate, oxygen, ammonium persulphate and sodium peroxide.

3. a kind of ionic metal coating for the pre-treatment of plastic substrate chemical plating copper according to claim 1, the pH buffer reagent that it is characterized in that in biological binder solution is a kind of or wherein several combination in borax, sodium-acetate, tris hydrochloride or SODIUM PHOSPHATE, MONOBASIC.

4. a kind of ionic metal coating for the pre-treatment of plastic substrate chemical plating copper according to claim 1, the silane coupling agent that it is characterized in that in biological binder solution is a kind of or wherein several combination in KH550, KH792, KH560 and KH602.

5. a kind of ionic metal coating for the pre-treatment of plastic substrate chemical plating copper according to claim 1,2,3 or 4, is characterized in that the preparation method of biological binder solution is as follows:

A, take the deionized water of the biological binding agent monomer of 0.5 ~ 15 part, the oxygenant of 0.1 ~ 5 part, the pH buffer reagent of 0.5 ~ 5 part, the silane coupling agent of 0.1 ~ 1 part and 75 ~ 95 parts by ratio of weight and the number of copies;

B, the deionized water of 2/3 is poured in encloses container, add pH buffer reagent and be stirred to dissolving, and then add biological binding agent monomer, be stirred to monomer and all dissolve;

C, under agitation, oxygenant to be joined in encloses container, then temperature be warming up to 45 ~ 50 DEG C by normal temperature and keep reaction 20 ~ 24h;

D, silane coupling agent is joined in encloses container, continue at 45 ~ 50 DEG C and keep reaction 20 ~ 24h;

E, remaining deionized water is poured in encloses container, stir, obtain biological binder solution.

6. a kind of ionic metal coating for the pre-treatment of plastic substrate chemical plating copper according to claim 1, is characterized in that metal-salt is palladium salt, silver salt, nickel salt or mantoquita; Wherein palladium salt is a kind of or wherein several combination in Palladous chloride, palladous sulfate and palladium; Silver salt is a kind of or wherein several combination in Silver Nitrate, silver fluoride and silver perchlorate; Nickel salt is a kind of or wherein several combination in nickelous chloride, nickel sulfamic acid, single nickel salt, nickel acetate and basic nickel carbonate; Mantoquita is a kind of or wherein several combination in copper sulfate, cupric nitrate and cupric chloride.

7. a kind of ionic metal coating for the pre-treatment of plastic substrate chemical plating copper according to claim 1 or 6, it is characterized in that metal chelating agent is thanomin, quadrol, sodium ethylene diamine tetracetate and N, a kind of or wherein several combination in N, N'N'-tetra-(2-hydroxypropyl) quadrol.

8. a kind of ionic metal coating for the pre-treatment of plastic substrate chemical plating copper according to claim 1 or 6, is characterized in that wetting agent is a kind of or wherein several combination in sodium lauryl sulphate, sodium laurylsulfonate and sodium cetanesulfonate.

9. utilize the ionic metal coating for the pre-treatment of plastic substrate chemical plating copper described in claim 1 to carry out the technique of plastic substrate chemical plating copper pre-treatment, it is characterized in that this technique is carried out according to the following steps:

One, electrochemical deoiling process is carried out to surface of plastic matrix;

Two, the ionic metal coating being used for the pre-treatment of plastic substrate chemical plating copper is coated in the plastic basis material surface processed through step one, then be dry 0.5 ~ 5min under the condition of 25 ~ 65 DEG C in temperature, obtain on plastic basis material surface the coating that build is 0.1 ~ 1 micron, complete the pre-treatment of plastic substrate chemical plating copper.

10. utilization according to claim 9 is used for the technique that the ionic metal coating of plastic substrate chemical plating copper pre-treatment carries out the pre-treatment of plastic substrate chemical plating copper, it is characterized in that described plastic substrate is general engineering plastics or pcb substrate.