Acid etching solution for aluminum-based circuit

Abstract

The invention discloses an aluminum-based circuit acidic etching solution, which relates to the technical field of etching, and comprises the following components by mass concentration: 30-60 g / L of composite inorganic acid, 10-20 g / L of a wetting agent, 5-15 g / L of a stabilizer, 5-15 g / L of an accelerator, 6-15 g / L of a brightener, 0.5-2.5 g / L of a composite anti-lateral corrosion agent, and 2-4 g / L of a complexing agent. According to the acid etching solution for the aluminum-based circuit, the lateral etching rate of a 50-75-micron thin circuit can be lower than 30%, the etching rate is stable, the etched appearance is bright and uniform, and the circuit does not have a burr phenomenon; the wetting agent is added, so that the etching uniformity can be improved, the burr phenomenon can be prevented, the adsorption rate of inorganic acid can be increased for the burr part which is difficult to treat, and the corrosion efficiency of the burr part can be improved; by adding the brightener, the phenomena of uneven partial etching and blackening of the surface after etching can be solved.

Description

Technical Field

[0001] The invention relates to the technical field of etching, in particular to an acidic etching solution for aluminum-based circuits. Background Art

[0002] Aluminum-based acid etching liquid is a liquid material used to etch the surface of aluminum and aluminum alloy metals. It is widely used in the surface treatment process of printed circuit boards, electronic components, instrument components and other materials.

[0003] Aluminum etching liquid destroys the oxide film on the surface of aluminum metal through its active ions. As corrosion continues, pitting is formed, and then high-pressure flushing by a high-pressure pump is used to achieve uniform corrosion, thereby achieving the purpose of etching. The application field of aluminum etching liquid is consistent with the application field of metal aluminum and its alloy thin film materials, and is mainly used in panel manufacturing scenarios in the field of liquid crystal displays.

[0004] As the market size of liquid crystal display panels continues to expand, the demand for aluminum etching liquid continues to increase, and the industry has a good development prospect. However, as an important type of wet electronic chemicals, aluminum etching liquid has high technical barriers. At present, there are relatively few R&D companies in the market, and the production capacity is still relatively low. In the future, it is necessary to continue to increase the intensity of technical research and development to promote the continuous improvement of market supply capacity.

[0005] During the production and application of aluminum etching solution, problems such as uneven etching depth and asymmetric etching may occur. These problems need to be solved by adjusting the solution concentration and correcting the operating procedures. In addition, the overall competition in the industry is relatively fierce, and companies need to continuously improve their technology and service levels to maintain their competitiveness.

[0006] Currently, no effective solution has been proposed for the problems in the related technologies. Summary of the invention

[0007] In view of the problems in the related art, the present invention proposes an aluminum-based circuit acid etching solution to overcome the above technical problems existing in the existing related art.

[0008] To this end, the specific technical solution adopted by the present invention is as follows:

[0009] An aluminum-based circuit acid etching solution comprises the following components in mass concentration:

[0010] Composite inorganic acid 30-60g / L, wetting agent 10-20g / L, stabilizer 5-15g / L, accelerator 5-15g / L, brightener 6-15g / L, composite anti-side corrosion agent 0.5-2.5g / L, complexing agent 2-4g / L.

[0011] Further, the composite inorganic acid is a combination of sulfuric acid and phosphoric acid;

[0012] Among them, the mass concentration of phosphoric acid is 10-20 g / L, and the mass concentration of sulfuric acid is 20-40 g / L.

[0013] Furthermore, the wetting agent is a pyridazine alkyl carboxylic acid compound, and the pyridazine alkyl carboxylic acid compound includes 6-methoxypyridazine-3-carboxylic acid.

[0014] Furthermore, the stabilizer is an aminonitropyridine compound, and the aminonitropyridine compound includes 4-amino-5-nitro-2-hydroxypyridine.

[0015] Furthermore, the composite anti-side corrosion agent is an aminohydroxypteridine compound, the aminohydroxypteridine compound is a composition of 2-amino-4-hydroxypteridine and 2,4-diamino-6-hydroxymethylpteridine, and the mass concentration ratio of 2-amino-4-hydroxypteridine and 2,4-diamino-6-hydroxymethylpteridine is 4:1.

[0016] Furthermore, the brightener is an aminoalkyl pteridine phosphate compound, and the aminoalkyl pteridine phosphate compound includes 2,4-diamino-6,7-diisopropyl pteridine phosphate.

[0017] Furthermore, the accelerator is an aminopyridine carboxylic acid compound, and the aminopyridine carboxylic acid compound includes 5-amino-2-methoxypyridine-4-carboxylic acid.

[0018] Furthermore, the complexing agent is triethanolamine.

[0019] Furthermore, the operating temperature of the etching solution during the etching process is 25-35°C.

[0020] Furthermore, the etching solution is sprayed during the etching process, and the spray pressure is 1.5-2.5 kg / cm 2 .

[0021] The beneficial effects of the present invention are:

[0022] 1. The aluminum-based circuit acid etching solution of the present invention can not only achieve a side etching rate of less than 30% for a 50-75 micron thin circuit, but also has a stable etching rate, a bright and uniform appearance after etching, and no burrs on the circuit; by adding a wetting agent, the uniformity of etching can be improved to prevent the occurrence of burrs, and for the parts where the burrs are difficult to handle, the adsorption rate of the inorganic acid can be accelerated to improve the corrosion efficiency of the parts.

[0023] 2. Adding brightener can solve the problem of uneven etching and black surface after etching. Some cleaning agents will be brought in a small amount during degreasing or the introduction of impurity ions. The roughness of the side of the aluminum layer during etching leads to adsorption on some side parts of the substrate, affecting the adsorption effect and causing blackening. Brightener can remove the adsorption effect of such impurities, thereby improving the etching brightness.

[0024] 3. By adding an anti-side corrosion agent, the solution can be prevented from penetrating under the organic film during the etching process, thereby causing serious side corrosion. The anti-side corrosion agent of the solution on the market is too strongly adsorbed, and a small amount will be adsorbed on the surface of the substrate during the etching process, resulting in black spots on the side, and its use is restricted. The anti-side corrosion agent of the present invention will be quickly cleared during use as the inorganic acid corrodes, and no black spots will remain.

[0025] 4. Adding stabilizers can prevent the instability caused by the impurity metal ions introduced by the previous process during the etching process. Accelerators can improve the corrosion efficiency and maintain the corrosion rate change range of no more than 20% for a long time within a month, ensuring that the corrosion efficiency is basically consistent. DETAILED DESCRIPTION

[0026] According to an embodiment of the present invention, an aluminum-based circuit acid etching solution is provided.

[0027] The aluminum-based circuit acid etching solution according to an embodiment of the present invention includes the following components in mass concentration:

[0028] Composite inorganic acid 30-60g / L, wetting agent 10-20g / L, stabilizer 5-15g / L, accelerator 5-15g / L, brightener 6-15g / L, composite anti-side corrosion agent 0.5-2.5g / L, complexing agent 2-4g / L.

[0029] In one embodiment, the composite inorganic acid is a combination of sulfuric acid and phosphoric acid, wherein the mass concentration of the phosphoric acid is 10-20 g / L, and the mass concentration of the sulfuric acid is 20-40 g / L.

[0030] In one embodiment, the wetting agent is a pyridazine alkyl carboxylic acid compound, and the pyridazine alkyl carboxylic acid compound includes 6-methoxypyridazine-3-carboxylic acid.

[0031] In one embodiment, the stabilizer is an aminonitropyridine compound, and the aminonitropyridine compound includes 4-amino-5-nitro-2-hydroxypyridine.

[0032] In one embodiment, the composite anti-side corrosion agent is an aminohydroxypteridine compound, the aminohydroxypteridine compound is a composition of 2-amino-4-hydroxypteridine and 2,4-diamino-6-hydroxymethylpteridine, and the mass concentration ratio of 2-amino-4-hydroxypteridine and 2,4-diamino-6-hydroxymethylpteridine is 4:1.

[0033] In one embodiment, the brightener is an aminoalkyl pteridine phosphate compound, and the aminoalkyl pteridine phosphate compound includes 2,4-diamino-6,7-diisopropyl pteridine phosphate.

[0034] In one embodiment, the accelerator is an aminopyridine carboxylic acid compound, and the aminopyridine carboxylic acid compound includes 5-amino-2-methoxypyridine-4-carboxylic acid.

[0035] In one embodiment, the complexing agent is triethanolamine.

[0036] In one embodiment, the operating temperature of the etching solution during the etching process is 25-35°C.

[0037] In one embodiment, the etching solution is sprayed during the etching process, and the spray pressure is 1.5-2.5 kg / cm 2 .

[0038] The evaluation indicators include: 1. Excellent stability index means that the etching rate is maintained for 30 days and above and the drop rate does not exceed 20%; good stability index means that the etching rate is maintained for 21-29 days and the drop rate does not exceed 20%; poor stability index means that the etching rate is maintained for 15-20 days and the drop rate does not exceed 20%; poor stability index means that the etching rate does not drop by more than 20% for 14 days and below. 2. The side etching effect is excellent when the side etching rate of 50 micron circuit does not exceed 30%; the side etching effect is good when the side etching rate of 50 micron circuit is 31-40%; the side etching effect is poor when the side etching rate of 50 micron circuit is 41-50%; the side etching effect is poor when the side etching rate of 50 micron circuit is 51% and above. 3. Excellent surface index means no pinholes and bright without nodules; excellent surface index means that individual pinholes can be seen and the brightness can see individual nodules; poor surface index means that the copper nodules of pinholes are significantly increased but bright; poor surface index means that the copper nodules of pinholes are pinholes and there are many and dark copper nodules. 4. An etching rate of 5 μm / min and above is excellent; an etching rate of 4-4.9 μm / min and above is good; an etching rate of 3-3.9 μm / min and above is poor; an etching rate of 2.9 μm / min and below is poor.

[0039] The following is a combination of specific embodiments and comparative examples, using the above evaluation indicators to conduct experimental analysis.

[0040] Example 1

[0041] Phosphoric acid 10g / L, sulfuric acid 40g / L, 6-methoxypyridazine-3-carboxylic acid 10g / L, 4-amino-5-nitro-2-hydroxypyridine 5g / L, 5-amino-2-methoxypyridine-4-carboxylic acid 5g / L, 2,4-diamino-6,7-diisopropylpteridine phosphate 15g / L, 2-amino-4-hydroxypteridine 2g / L, 2,4-diamino-6-hydroxymethylpteridine 0.5g / L, triethanolamine 2g / L;

[0042] The balance is pure water; the temperature is 30℃, and the spray pressure is 2kg / cm2. 2 , time 10 minutes.

[0043] The experimental results of Example 1 are: excellent stability index, excellent side etching effect, excellent surface index, and excellent etching rate.

[0044] Example 2

[0045] Phosphoric acid 20g / L, sulfuric acid 20g / L, 6-methoxypyridazine-3-carboxylic acid 10g / L, 4-amino-5-nitro-2-hydroxypyridine 15g / L, 5-amino-2-methoxypyridine-4-carboxylic acid 15g / L, 2,4-diamino-6,7-diisopropylpteridine phosphate 6g / L, 2-amino-4-hydroxypteridine 0.4g / L, 2,4-diamino-6-hydroxymethylpteridine 0.1g / L, triethanolamine 4g / L;

[0046] The balance is pure water; the temperature is 30℃, and the spray pressure is 2kg / cm2. 2 , time 10 minutes.

[0047] The experimental results of Example 2 are: excellent stability index, excellent side etching effect, excellent surface index, and excellent etching rate.

[0048] Example 3

[0049] Phosphoric acid 15g / L, sulfuric acid 30g / L, 6-methoxypyridazine-3-carboxylic acid 15g / L, 4-amino-5-nitro-2-hydroxypyridine 10g / L, 5-amino-2-methoxypyridine-4-carboxylic acid 10g / L, 2,4-diamino-6,7-diisopropylpteridine phosphate 11g / L, 2-amino-4-hydroxypteridine 1.2g / L, 2,4-diamino-6-hydroxymethylpteridine 0.3g / L, triethanolamine 3g / L;

[0050] The balance is pure water; the temperature is 30℃, and the spray pressure is 2kg / cm2. 2 , time 10 minutes.

[0051] The experimental results of Example 3 are: excellent stability index, excellent side etching effect, excellent surface index, and excellent etching rate.

[0052] Comparative Example 1

[0053] Phosphoric acid 15g / L, sulfuric acid 30g / L, 4-amino-5-nitro-2-hydroxypyridine 10g / L, 5-amino-2-methoxypyridine-4-carboxylic acid 10g / L, 2,4-diamino-6,7-diisopropylpteridine phosphate 11g / L, 2-amino-4-hydroxypteridine 1.2g / L, 2,4-diamino-6-hydroxymethylpteridine 0.3g / L, triethanolamine 3g / L;

[0054] The balance is pure water; the temperature is 30℃, and the spray pressure is 2kg / cm2. 2 , time 10 minutes.

[0055] The experimental results of comparative example 1 lacking a wetting agent compared with example 3 are as follows: excellent stability index, excellent side etching effect, good surface index, and excellent etching rate.

[0056] Comparative Example 2

[0057] Phosphoric acid 15g / L, sulfuric acid 30g / L, 6-methoxypyridazine-3-carboxylic acid 15g / L, 5-amino-2-methoxypyridine-4-carboxylic acid 10g / L, 2,4-diamino-6,7-diisopropylpteridine phosphate 11g / L, 2-amino-4-hydroxypteridine 1.2g / L, 2,4-diamino-6-hydroxymethylpteridine 0.3g / L, triethanolamine 3g / L;

[0058] The balance is pure water; the temperature is 30℃, and the spray pressure is 2kg / cm2. 2 , time 10 minutes.

[0059] Compared with Example 3, the experimental results of Comparative Example 2 lacking a stabilizer are as follows: poor stability index, good side etching effect, good surface index, and excellent etching rate.

[0060] Comparative Example 3

[0061] Phosphoric acid 15g / L, sulfuric acid 30g / L, 6-methoxypyridazine-3-carboxylic acid 15g / L, 4-amino-5-nitro-2-hydroxypyridine 10g / L, 2,4-diamino-6,7-diisopropylpteridine phosphate 11g / L, 2-amino-4-hydroxypteridine 1.2g / L, 2,4-diamino-6-hydroxymethylpteridine 0.3g / L, triethanolamine 3g / L;

[0062] The balance is pure water; the temperature is 30℃, and the spray pressure is 2kg / cm2. 2 , time 10 minutes.

[0063] Compared with Example 3, the experimental results of Comparative Example 3 lacking an accelerator are as follows: excellent stability index, good side etching effect, good surface index, and poor etching rate.

[0064] Comparative Example 4

[0065] Phosphoric acid 15g / L, sulfuric acid 30g / L, 6-methoxypyridazine-3-carboxylic acid 15g / L, 4-amino-5-nitro-2-hydroxypyridine 10g / L, 5-amino-2-methoxypyridine-4-carboxylic acid 10g / L, 2-amino-4-hydroxypteridine 1.2g / L, 2,4-diamino-6-hydroxymethylpteridine 0.3g / L, triethanolamine 3g / L;

[0066] The balance is pure water; the temperature is 30℃, and the spray pressure is 2kg / cm2. 2 , time 10 minutes.

[0067] Compared with Example 3, the experimental results of Comparative Example 4 lacking brightener are as follows: excellent stability index, good side etching effect, good surface index, and excellent etching rate.

[0068] Comparative Example 5

[0069] Phosphoric acid 15g / L, sulfuric acid 30g / L, 6-methoxypyridazine-3-carboxylic acid 15g / L, 4-amino-5-nitro-2-hydroxypyridine 10g / L, 5-amino-2-methoxypyridine-4-carboxylic acid 10g / L, 2,4-diamino-6,7-diisopropylpteridine phosphate 11g / L, triethanolamine 3g / L;

[0070] The balance is pure water; the temperature is 30℃, and the spray pressure is 2kg / cm2. 2 , time 10 minutes.

[0071] Compared with Example 3, the comparative example 5 lacks the composite anti-side etching agent and the experimental results are: excellent stability index, poor side etching effect, good surface index and excellent etching rate.

[0072] Comparative Example 6

[0073] Phosphoric acid 15g / L, sulfuric acid 30g / L, 6-methoxypyridazine-3-carboxylic acid 15g / L, 4-amino-5-nitro-2-hydroxypyridine 10g / L, 5-amino-2-methoxypyridine-4-carboxylic acid 10g / L, 2,4-diamino-6,7-diisopropylpteridine phosphate 11g / L, 2-amino-4-hydroxypteridine 1.2g / L, 2,4-diamino-6-hydroxymethylpteridine 0.3g / L;

[0074] The balance is pure water; the temperature is 30℃, and the spray pressure is 2kg / cm2. 2 , time 10 minutes.

[0075] Compared with Example 3, Comparative Example 6 lacks a complexing agent, and the experimental results obtained are: poor stability index, good side etching effect, good surface index, and excellent etching rate.

[0076] In summary, by means of the above technical scheme of the present invention, the uniformity of etching can be improved by adding a wetting agent, and the occurrence of burr phenomenon can be prevented. For the difficult-to-handle parts at the burr, the adsorption rate of inorganic acid can be accelerated, and the corrosion efficiency of the parts can be improved. By adding a brightener, the phenomenon of uneven etching and blackening of the surface can be solved. Due to the introduction of some cleaning agents or impurity ions in a small amount during degreasing, the roughness of the side of the aluminum layer during etching is large, resulting in adsorption at some side parts of the substrate, affecting the adsorption effect, resulting in blackening, and the brightener can remove the adsorption effect of such impurities, thereby improving the etching brightness. By adding an anti-side corrosion agent, the liquid medicine can be prevented from infiltrating under the organic film during etching, and then serious side corrosion occurs. The anti-side corrosion agent of the liquid medicine on the market is too strong in adsorption, and will be adsorbed on the substrate surface in a small amount during etching, thereby causing black spot phenomenon on the side, and the use is limited. The anti-side corrosion agent of the present invention will be quickly cleared with the corrosion of inorganic acid during use, and no black spot phenomenon will remain. By adding stabilizers, the instability caused by the impurity metal ions introduced by the previous process can be prevented during the etching process. Accelerators can improve the corrosion efficiency and maintain the corrosion rate change range within 20% for a long time within a month, ensuring that the corrosion efficiency is basically consistent.

[0077] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An aluminum-based circuit acid etching solution, characterized in that: The following components are included in mass concentration: Composite inorganic acid 30-60g / L, wetting agent 10-20g / L, stabilizer 5-15g / L, accelerator 5-15g / L, brightener 6-15g / L, composite anti-side corrosion agent 0.5-2.5g / L, complexing agent 2-4g / L.

2. The aluminum-based circuit acid etching solution according to claim 1, characterized in that: The composite inorganic acid is a combination of sulfuric acid and phosphoric acid; Among them, the mass concentration of phosphoric acid is 10-20 g / L, and the mass concentration of sulfuric acid is 20-40 g / L.

3. An aluminum-based circuit acid etching solution according to claim 2, characterized in that: The wetting agent is a pyridazine alkyl carboxylic acid compound, and the pyridazine alkyl carboxylic acid compound includes 6-methoxypyridazine-3-carboxylic acid.

4. The aluminum-based circuit acid etching solution according to claim 1, characterized in that: The stabilizer is an aminonitropyridine compound, and the aminonitropyridine compound includes 4-amino-5-nitro-2-hydroxypyridine.

5. The aluminum-based circuit acid etching solution according to claim 1, characterized in that: The composite anti-side corrosion agent is an aminohydroxypteridine compound, which is a composition of 2-amino-4-hydroxypteridine and 2,4-diamino-6-hydroxymethylpteridine, and the mass concentration ratio of 2-amino-4-hydroxypteridine to 2,4-diamino-6-hydroxymethylpteridine is 4:

1.

6. The aluminum-based circuit acid etching solution according to claim 1, characterized in that: The brightener is an aminoalkyl pteridine phosphate compound, and the aminoalkyl pteridine phosphate compound includes 2,4-diamino-6,7-diisopropyl pteridine phosphate.

7. The aluminum-based circuit acid etching solution according to claim 1, characterized in that: The accelerator is an aminopyridine carboxylic acid compound, and the aminopyridine carboxylic acid compound includes 5-amino-2-methoxypyridine-4-carboxylic acid.

8. The aluminum-based circuit acid etching solution according to claim 1, characterized in that: The complexing agent is triethanolamine.

9. The aluminum-based circuit acid etching solution according to claim 1, characterized in that: The operating temperature of the etching solution during the etching process is 25-35°C.

10. The aluminum-based circuit acid etching solution according to claim 9, characterized in that: The etching solution is sprayed during the etching process, and the spray pressure is 1.5-2.5 kg / cm 2 .