CN111020585A

CN111020585A - Coarsening micro-etching solution of hydrogen sulfate peroxide system and application thereof

Info

Publication number: CN111020585A
Application number: CN201911384994.0A
Authority: CN
Inventors: 王亚君; 章晓冬; 童茂军
Original assignee: Suzhou Skychem Ltd
Current assignee: Suzhou Skychem Ltd
Priority date: 2019-12-28
Filing date: 2019-12-28
Publication date: 2020-04-17

Abstract

The invention relates to a coarsening micro-etching solution of a sulfuric acid-hydrogen peroxide system and application thereof. The coarsening micro-etching solution of the hydrogen sulfate peroxide system has low and stable micro-etching rate in the micro-etching process, high copper ion capacity, uniform roughness of the plate surface after micro-etching and no blackening, can enable a dry film to be more tightly combined with the copper surface, and greatly reduce the fraction defective of circuit manufacture. The preparation method is simple to operate, low in cost, free of environmental pollution and suitable for industrial production.

Description

Coarsening micro-etching solution of hydrogen sulfate peroxide system and application thereof

Technical Field

The invention belongs to the technical field of chemical microetching liquid, and particularly relates to coarsening microetching liquid of a hydrogen sulfate peroxide system and application thereof.

Background

In the manufacturing process flow of the printed circuit board, the transfer of the circuit pattern and the pretreatment thereof are important parts. The pretreatment is used for treating the surface of the copper foil, and the method comprises three methods of mechanical plate grinding, sand blasting and chemical microetching, and aims to ensure that the copper foil forms a rough surface and can be closely attached to a photosensitive corrosion-resistant film so as to ensure the qualification rate of circuit manufacturing. After mechanical grinding of the plate, there are conditions of directional scratches, etc. on the copper surface. The sand blasting has poor capability of removing the defects generated in the previous process and the thicker and denser oxide layer. The chemical microetching has small abrasion loss on the copper surface, can form rough and uniform grooves without plowing, and can provide better roughness for the next film pasting process.

CN105734571A discloses a metal surface micro-etching solution, which is composed of the following raw materials in percentage by mass: 15-25% of dilute sulfuric acid with the mass fraction of 50%, 10-15% of hydrogen peroxide, 2-5% of stabilizing agent, 0.5-1% of surfactant, 0.2% of antibacterial agent and the balance of water. The metal surface micro-etching solution enables the copper surface of the circuit board to achieve uniform roughness and cleanliness, increases the binding force of the copper surface with the pattern layer and the film, and has the characteristics of low toxicity, less pollution, convenient use, rapid treatment of metal surface oxides and improvement of metal surface cleanliness. The microetching liquid product has wide application, and is mainly used for the pretreatment of oxide removal on the surface of metal and the pretreatment of metal coloring. And can also be used in the metallurgical industries of electronic circuit board copper surface super-roughening, oxidation removing treatment, mechanical processing, metal deep processing, spraying and the like.

CN101033550B discloses a micro-etching solution and application thereof in pretreatment of silver deposition of a printed circuit board. It discloses that the silver precipitation microetching liquid comprises the following components in percentage by weight: 80-100g/L of sodium persulfate, 1.5-2.5% of sulfuric acid and 0.10-0.30mol/L of C2-C8 organic acid. The application of the silver deposition pretreatment is that the printed circuit board needing silver plating is subjected to conventional acid degreasing to remove copper surface oxide and grease thereof, then the circuit board is immersed into the microetching solution, the temperature of the microetching solution is controlled at 32-40 ℃, the circuit board is treated in the microetching solution for 1.5-2.5 minutes, and the microetched circuit board is immersed into the silver deposition plating solution for 1.5-2.5 minutes, so that a layer of uniform and bright silver is obtained and deposited on the copper surface. The micro-etching solution can adjust the instantaneous micro-etching rate, keep the copper surface smooth, improve the flatness of the silver coating, ensure the surface of the silver coating to be bright, improve the weldability and the anti-aging capability of the coating, and has simple process and low cost.

CN110029348A discloses a microetching solution for treating copper surface, comprising the following components: 1,2, 4-triazole, 2-isopropylimidazole, 3, 5-dimethylpyrazole, 6-nitrobenzimidazole, triethylene glycol, 1, 2-propylene glycol, heptylamine, sulfuric acid, polypropylene glycol, sodium alginate and water. By the mode, the microetching liquid for treating the copper surface is easy to dilute and apply, convenient to treat, uniform in surface microetching effect, multiple in use modes and capable of being applied to printed circuit board manufacturing engineering.

Among the types of microetching solution, the microetching solution of a hydrogen sulfate peroxide system is superior, and has the advantages of stable microetching rate, large copper capacity, simple post-treatment, no pollution and the like.

Disclosure of Invention

In view of the defects of the prior art, the invention aims to provide a roughening micro-etching solution of a hydrogen sulfate peroxide system and application thereof. The micro-etching solution can control the micro-etching rate, and the roughness of the copper surface is uniform, so that the dry film and the copper surface are tightly combined, and the reject ratio of circuit manufacturing can be greatly reduced.

In order to achieve the purpose, the invention adopts the following technical scheme:

in one aspect, the invention provides a roughening micro-etching solution of a sulfuric acid and hydrogen peroxide system, wherein the roughening micro-etching solution comprises sulfuric acid, hydrogen peroxide, a corrosion inhibitor, halide ions, a complexing agent and water.

The corrosion inhibitor is added into the roughening micro-etching solution, so that an organic protective film is formed on the surface of copper and the copper to delay the corrosion of the copper, but the protective film cannot perfectly cover the whole copper surface, a plurality of points on the copper surface cannot be protected by the organic film, at the moment, the high-concentration sulfuric acid-hydrogen peroxide accelerates the corrosion of the copper, the copper surface protected by the organic film is not corroded or is corroded slowly, the copper surface unprotected by the organic film is corroded quickly, and the copper forms roughness. The halogen ions are added because the halogen ions can inhibit the decomposition of hydrogen peroxide to a certain extent, further effectively reduce the concentration of peroxide radicals, maintain the concentration of the hydrogen peroxide in the microetching solution and stabilize the microetching rate in the microetching process, and can complex cuprous ions on the surface of copper, improve the roughness of the surface of the microetching board, enable a dry film to be more tightly combined with the copper surface and greatly reduce the defect rate of circuit manufacturing. The complexing agent is added to complex copper ions, so that the self-decomposition of hydrogen peroxide can be further reduced, the stable microetching rate is achieved, and the roughness of the plate surface after the microetching is uniform.

Preferably, the coarsening micro-etching solution comprises 20-100g/L of sulfuric acid, 10-70g/L of hydrogen peroxide, 0.01-10g/L of corrosion inhibitor, 0.05-10ppm of halide ions, 10-50g/L of complexing agent and water.

When the five components of the sulfuric acid, the hydrogen peroxide, the corrosion inhibitor, the halide ions and the complexing agent are matched according to the concentration range, the micro-etching effect is more obvious, particularly, the micro-etching rate is more stable, the roughness of the copper surface is uniform and does not blacken after the micro-etching, the dry film can be more tightly combined with the copper surface, and the reject ratio of circuit manufacturing is more reduced.

The concentration of the sulfuric acid can be 20g/L, 30g/L, 40g/L, 50g/L, 60g/L, 70g/L, 80g/L, 90g/L, 100g/L, or the like.

The concentration of hydrogen peroxide can be 10g/L, 15g/L, 20g/L, 25g/L, 30g/L, 35g/L, 40g/L, 50g/L, 55g/L, 60g/L, 70g/L, or the like.

The concentration of the corrosion inhibitor can be 0.01g/L, 0.05g/L, 0.1g/L, 0.2g/L, 0.5g/L, 0.8g/L, 1g/L, 2g/L, 4g/L, 5g/L, 6g/L, 8g/L or 10g/L, etc.

The halide ion concentration may be 0.05ppm, 0.1ppm, 0.2ppm, 0.5ppm, 0.8ppm, 1ppm, 2ppm, 3ppm, 5ppm, 6ppm, 8ppm, 10ppm, or the like.

The concentration of the complexing agent can be 10g/L, 15g/L, 20g/L, 25g/L, 30g/L, 35g/L, 40g/L or 50g/L, etc.

Preferably, the coarsening micro-etching solution comprises 30-50g/L of sulfuric acid, 10-30g/L of hydrogen peroxide, 0.1-2g/L of corrosion inhibitor, 0.05-3ppm of halide ions, 20-40g/L of complexing agent and water. The technical effect is better when the combination is carried out in the concentration range.

Preferably, the complexing agent comprises any one or a combination of at least two of EDTA-2Na, thiourea complexing agent (such as C610 thiourea resin), sulfhydryl complexing agent (C620 sulfhydryl resin), sodium citrate, potassium citrate, sodium tartrate, sodium gluconate, potassium gluconate, alcohol amine complexing agent (such as monoethanolamine, diethanolamine, triethanolamine) or maleic anhydride-acrylic acid complexing agent (such as acrylic acid-maleic anhydride copolymer); the combination of at least two of the above-mentioned compounds, for example, the combination of EDTA-2Na and thiourea complexing agent, the combination of mercapto complexing agent and sodium citrate, the combination of sodium tartrate and sodium gluconate, and the like, may be selected in any combination manner, and thus, it is not repeated herein.

Preferably, the corrosion inhibitor comprises any one or a combination of at least two of diazole and derivatives thereof, triazole and derivatives thereof, tetrazole and derivatives thereof; the combination of at least two of the above compounds, such as the combination of diazole and triazole, the combination of triazole and tetrazole, the combination of diazole derivative and triazole derivative, etc., and any other combination modes are not repeated herein.

Preferably, the corrosion inhibitor comprises any one or a combination of at least two of benzotriazole, 2-mercaptobenzothiazole, methylbenzotriazole, 4-carboxyl benzotriazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole or 5-amino-1H-tetrazole; the combination of at least two of them is, for example, a combination of benzotriazole and 2-mercaptobenzothiazole, a combination of methylbenzotriazole and 4-carboxybenzotriazole, a combination of 5-methyl-1H-tetrazole and 5-phenyl-1H-tetrazole, etc., and any other combination modes are not repeated herein.

Preferably, the halide ions include any one or a combination of at least two of chloride ions, bromide ions, or iodide ions, for example, a combination of chloride ions and bromide ions, a combination of bromide ions and iodide ions, a combination of chloride ions and iodide ions, and the like, and any other combination manner is not repeated herein.

The chloride ion is derived from water-soluble chloride, the bromide ion is derived from water-soluble bromide, and the iodide ion is derived from water-soluble iodide.

Preferably, the halide is chloride.

Compared with bromide ion and iodide ion, the technical effect obtained by the chloride ion is better, because the peroxide has oxidizing property and reducing property, the reducing effect of the bromide ion and the iodide ion is relatively stronger, and the peroxide is easy to reduce.

The preparation method of the coarsening micro-etching solution of the hydrogen sulfate peroxide system comprises the following steps: mixing hydrogen peroxide, a corrosion inhibitor, halide ions, a complexing agent and water according to the formula amount, stirring, and finally adding sulfuric acid to obtain the coarsening micro-etching solution of the sulfuric acid hydrogen peroxide system.

The preparation method has the advantages of simple operation, low cost, no environmental pollution, and suitability for industrial production.

In another aspect, the present invention relates to the use of the above-mentioned hydrogen sulfate peroxide system roughening microetching solution for chemically microetching copper foil surfaces.

Preferably, the temperature at which the chemical microetching is performed on the surface of the copper foil is 20 to 40 ℃, for example, 20 ℃, 25 ℃, 28 ℃, 30 ℃, 32 ℃, 35 ℃, 38 ℃ or 40 ℃.

Preferably, the chemical microetching time for the surface of the copper foil is 30-120s, such as 30s, 40s, 50s, 60s, 70s, 80s, 90s, 100s, 110s or 120 s.

When the roughening microetching solution of the hydrogen sulfate peroxide system is used for carrying out chemical microetching on the surface of the copper foil, the microetching time and temperature need to be controlled well, and when the temperature is kept at 20-40 ℃ and the time is kept at 30-120s, the microetching effect is better.

In another aspect, the invention provides an application of the roughening microetching solution of the hydrogen sulfate peroxide system in a manufacturing process of a printed circuit board.

Compared with the prior art, the invention has the following beneficial effects:

the coarsening micro-etching solution of the hydrogen sulfate peroxide system has low and stable micro-etching rate in the micro-etching process, uniform roughness of the copper surface after micro-etching, no blackening, capability of enabling a dry film to be more tightly combined with the copper surface and greatly reducing the fraction defective of circuit manufacturing. The preparation method is simple to operate, low in cost, free of environmental pollution and suitable for industrial production.

Drawings

FIG. 1 is an SEM image of a copper surface after microetching using the roughening microetching solution prepared in example 1;

FIG. 2 is an SEM image of a copper surface after microetching using the roughening microetching solution prepared in example 2;

FIG. 3 is an SEM image of a copper surface after microetching using the roughening microetching solution prepared in example 3;

FIG. 4 is an SEM image of a copper surface after microetching using the roughening microetching solution prepared in example 4;

FIG. 5 is an SEM image of a copper surface after microetching using the roughening microetching solution prepared in example 5;

FIG. 6 is an SEM image of a copper surface after microetching using the roughening microetching solution prepared in example 6;

FIG. 7 is an SEM image of a copper surface after microetching using the roughening microetching solution prepared in example 7;

FIG. 8 is an SEM image of a copper surface after microetching using the roughening microetching solution prepared in example 8;

FIG. 9 is an SEM image of a copper surface after microetching using the roughening microetching solution prepared in example 9;

FIG. 10 is an SEM image of a copper surface after microetching using the roughening microetching solution prepared in comparative example 1;

fig. 11 is an SEM image of a copper surface after microetching using the roughening microetching solution prepared in comparative example 2.

Detailed Description

The technical solution of the present invention is further explained by the following embodiments. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

Example 1

The present embodiment provides a roughening microetching solution for a hydrogen sulfate peroxide system, wherein the formula of the roughening microetching solution is as follows:

the preparation method comprises the following steps: mixing hydrogen peroxide, a corrosion inhibitor, halide ions, a complexing agent and water according to the formula amount, stirring, and finally adding sulfuric acid to obtain the roughening micro-etching solution of the sulfuric acid hydrogen peroxide system.

Example 2

Example 3

Example 4

Example 5

Example 6

Example 7

Example 8

This example provides a hydrogen sulfate peroxide system roughening microetch solution formulated to replace only "sodium chloride" with "sodium bromide" as compared to example 2, all other things remaining the same.

The preparation process was identical to example 2.

Example 9

This example provides a hydrogen sulfate peroxide system roughening microetch solution whose formulation compared to example 2 only replaced "sodium chloride" with "sodium iodide", all else remaining the same.

The preparation process was identical to example 2.

Comparative example 1

This comparative example provides a hydrogen sulfate peroxide system roughening microetch, which is formulated to be substantially identical to that of example 2 except that the formulation does not contain halide ions.

The preparation process was identical to example 2.

Comparative example 2

The present comparative example provides a hydrogen sulfate peroxide system roughening microetch solution whose formulation differs from that of example 2 only in that it does not contain a complexing agent, all else remaining the same.

The preparation process was identical to example 2.

Evaluation test:

the roughening microetching solutions prepared in examples 1 to 9 and comparative examples 1 to 2 were used for microetching of copper foil, and the operation was substantially as follows: and (3) placing the copper-clad plate of which the thickness is 5cm multiplied by 5cm into a beaker by using a plastic clamp to uniformly and quickly shake, completely immersing the copper plate by the solution, taking out the copper plate after the solution is immersed for a specified time, cleaning the copper plate by using deionized water, and completely drying the copper plate.

AFM characterization was performed on the microetched copper foil, and roughness indices Ra and Rz (from the viewpoint of roughness, the larger the value, the better) were calculated, and the results are shown in Table 1 (wherein ISAD: specific surface area change/difference in area). SEM characterization was performed on each group of copper foils microetched at 30 ℃ for 60s, and the results are shown in fig. 1-11.

TABLE 1

From the data in table 1 and fig. 1-11, it can be seen that: the coarsening micro-etching solution of the hydrogen sulfate peroxide system related by the invention ensures that the surface roughness is high and uniform after micro-etching, wherein the mass ratio of each component of the micro-etching solution, whether the micro-etching solution contains halogen ions or complexing agents and the type of the halogen ions can all have important influence on the micro-etching effect.

The applicant states that the present invention is described by the above examples to describe the roughening microetching solution of hydrogen sulfate peroxide system and the application thereof, but the present invention is not limited to the above examples, i.e., it is not intended that the present invention is implemented by relying on the above examples. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

Claims

1. The roughening micro-etching solution of a sulfuric acid-hydrogen peroxide system is characterized by comprising sulfuric acid, hydrogen peroxide, a corrosion inhibitor, halide ions, a complexing agent and water.

2. The roughening microetching solution according to claim 1, wherein said roughening microetching solution comprises 20 to 100g/L sulfuric acid, 10 to 70g/L hydrogen peroxide, 0.01 to 10g/L corrosion inhibitor, 0.05 to 30ppm halide ion, 10 to 50g/L complexing agent, and water.

3. The roughening microetching solution according to the sulfuric acid-hydrogen peroxide system according to claim 1 or 2, wherein the roughening microetching solution comprises 30 to 50g/L of sulfuric acid, 10 to 30g/L of hydrogen peroxide, 0.1 to 2g/L of a corrosion inhibitor, 0.05 to 3ppm of a halide ion, 20 to 40g/L of a complexing agent, and water.

4. The roughening microetching solution according to any one of claims 1 to 3, wherein said complexing agent comprises any one or a combination of at least two of EDTA-2Na, thiourea complexing agents, mercapto complexing agents, sodium citrate, potassium citrate, sodium tartrate, sodium gluconate, potassium gluconate, alkanolamine complexing agents, and maleic anhydride-acrylic acid complexing agents.

5. The roughening microetch solution according to any one of claims 1 to 4, wherein said corrosion inhibitor comprises any one or a combination of at least two of diazole and its derivatives, triazole and its derivatives, tetrazole and its derivatives;

preferably, the corrosion inhibitor comprises any one or a combination of at least two of benzotriazole, 2-mercaptobenzothiazole, methylbenzotriazole, 4-carboxybenzotriazole, 5-methyl-1H-tetrazole, 5-phenyl-1H-tetrazole or 5-amino-1H-tetrazole.

6. The roughening microetch solution according to any one of claims 1 to 5, wherein said halide ions comprise any one or a combination of at least two of chloride, bromide, or iodide ions.

7. The roughening microetch solution according to any one of claims 1 to 6, wherein said halide ion is chloride.

8. Use of a roughening microetching solution of the hydrogen sulfate peroxide system according to any one of claims 1 to 7 for chemical microetching of copper foil surfaces.

9. The use of claim 8, wherein the chemical microetching of the copper foil surface is carried out at a temperature of 20 ℃ to 40 ℃;

preferably, the chemical microetching time for the surface of the copper foil is 30-120 s.

10. Use of a roughening microetching solution of a hydrogen sulfate peroxide system according to any one of claims 1 to 7 in a process for manufacturing a printed wiring board.