Copper alloy film etching liquid composition
By adding a specific proportion of components to the copper etching liquid, the problems of unstable etching rate, excessive particle clusters and filter clogging in the existing copper etching technology are solved, and a more stable etching rate and longer filter cleaning time are achieved.
Patent Information
- Application Number
- CN202411700140.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-26
- Publication Date
- 2025-04-04
AI Technical Summary
In the existing copper etching technology, there are problems such as unstable etching rate, incomplete copper etching, excessive etching of other metal materials, and the etching solution is prone to block the filter screen.
A copper alloy film etching liquid composition is provided, which comprises components such as ferric chloride, hydrochloric acid, chelating agent, surfactant, fluoride, polymerization inhibitor, corrosion inhibitor, pH adjuster, etc., and is prepared in a specific proportion to improve the stability and effect of the etching liquid.
The relatively stable etching rate of copper etching liquid is achieved, the number of particles with a diameter of ≥0.5mm is reduced, the probability of particle clusters is reduced, and the cleaning time of the filter is increased.
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Figure CN119753685A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of etching solutions, and in particular to a copper alloy film etching solution composition. Background Art
[0002] With the advancement of printed circuit board (PCB) technology, the line width requirements of copper foil are becoming more and more stringent. In the printed circuit board process, in order to improve the bonding strength between the copper surface and the dry film, solder mask, ABF film or ink, the copper surface is roughened to increase the specific surface area of copper. The mechanism of the existing roughening liquid to treat the copper layer is to form a uniform roughening morphology on the copper surface through the difference in micro-etching rate between different crystal directions and between crystals.
[0003] In the manufacturing process of flexible printed circuit boards (FPCs), copper etching liquid plays a vital role as a key technology and material. Copper etching liquid is used to remove unnecessary copper materials on the surface of FPCs to form precise circuit patterns and wires. Its etching quality and rate control directly affect the performance, reliability and production efficiency of FPCs.
[0004] The existing copper etching technology has problems such as unstable etching rate, incomplete copper etching, excessive etching of other metal materials, and easy clogging of the filter by the solution after etching. Summary of the invention
[0005] In order to solve the above-mentioned deficiencies in the art, the present application aims to provide a copper alloy film etching solution composition.
[0006] According to one aspect of the present application, a copper alloy film etching solution composition is provided, comprising the following components:
[0007] Ferric chloride: 21-30wt%;
[0008] Hydrochloric acid: 10-18wt%;
[0009] Chelating agent: 0-12wt%;
[0010] Surfactant: 0-0.5wt%;
[0011] Fluoride: 0-1wt%;
[0012] Inhibitor: 0-0.5wt%;
[0013] Corrosion inhibitor: 0-0.6wt%;
[0014] pH regulator: 0-3wt%;
[0015] Ultrapure water: balance.
[0016] According to another aspect of the present application, the copper alloy film etching solution composition comprises the following components:
[0017] Ferric chloride: 23-28wt%;
[0018] Hydrochloric acid: 12-16wt%;
[0019] Chelating agent: 7-12wt%;
[0020] Surfactant: 0.2-0.4wt%;
[0021] Fluoride: 0.03-0.05wt%;
[0022] Inhibitor: 0.1-0.2wt%;
[0023] Corrosion inhibitor: 0.3-0.5wt%;
[0024] pH regulator: 1-2wt%;
[0025] Ultrapure water: balance.
[0026] According to some embodiments of the present application, the chelating agent is selected from: ethylenediaminetetraacetic acid and / or hydroxyethylidene diphosphonic acid. Preferably, ethylenediaminetetraacetic acid
[0027] According to some embodiments of the present application, the surfactant is selected from: fatty alcohol polyoxyethylene ether and / or hexadecyl trimethyl ammonium chloride. Fatty alcohol polyoxyethylene ether is preferred.
[0028] According to some embodiments of the present application, the fluoride is selected from: ammonium bifluoride and perfluoropolyether carboxylic acid propylene oxide ammonium [CF (CF3) CF2O)] n A mixture of COONHCH2CHCH2O, n=5-10. .
[0029] According to some embodiments of the present application, the mass ratio of ammonium bifluoride to ammonium perfluoropolyether carboxylate propylene oxide is 1:(2-10); optionally, the mass ratio is 1:2.
[0030] According to some embodiments of the present application, the polymerization inhibitor is selected from one or more of: N-nitrosodiphenylamine, o-methyl-p-benzoquinone, and 5-nitroso-8-hydroxyquinoline. Preferably, 5-nitroso-8-hydroxyquinoline:N-nitrosodiphenylamine is added in a ratio of 1:1.
[0031] According to some embodiments of the present application, the corrosion inhibitor is selected from: benzotriazole and / or 5-methyltetrazole, preferably 5-methyltetrazole.
[0032] According to some embodiments of the present application, the pH adjuster is selected from: one or more of 2,6-di-tert-butyl-p-methylphenol, acrylamide, triethanolamine, 2-amino-2-methyl-1-propanol and n-butylphenylpropionamide. Preferably, 2,6-di-tert-butyl-p-methylphenol and triethanolamine are added in a ratio of 1:2.
[0033] According to some embodiments of the present application, the pH adjuster is a 1:1 mixture of a pH adjuster and a wetting agent;
[0034] Optionally, the wetting agent is selected from TEGO surten 202E, 232E or W111.
[0035] Compared with the prior art, this application has at least the following beneficial effects:
[0036] The present application provides a copper alloy film etching liquid composition. Compared with previous etching liquids, the etching liquid has a more stable etching rate during use (the etching rate remains basically constant during 80% of the time during use), the number of particles with a diameter ≥ 0.5 mm is reduced by about 80%, the probability of particle clusters occurring is reduced by more than 2 / 3, and the cleaning time of the filter is increased from once every 8 hours to once every 24 hours.
[0037] The fluoride is added after being mixed with ammonium bifluoride and ammonium perfluoropolyether carboxylate propylene oxide, which can better disperse the ammonium bifluoride in the solution and improve the surface roughness of the ammonium bifluoride etching. BRIEF DESCRIPTION OF THE DRAWINGS
[0038] Figure 1 This is an electron microscope photograph of the cross section of the copper foil before etching according to an exemplary embodiment of the present application.
[0039] Figure 2 This is an electron microscope photograph of the cross section of the copper foil after etching according to an exemplary embodiment of the present application.
[0040] Figure 3 , Figure 4 This is the surface morphology of the copper foil before etching according to an exemplary embodiment of the present application.
[0041] Figure 5-Figure 8 This is the surface morphology of the copper foil after etching according to an exemplary embodiment of the present application.
[0042] Fig. 9 This is a schematic diagram of the component ratio of Example 1 of the present application. DETAILED DESCRIPTION
[0043] The technical solution of the present application will be clearly and completely described below in conjunction with the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.
[0044] It is particularly important to point out that similar substitutions and modifications made to the present application are obvious to those skilled in the art, and they are all deemed to be included in the present application. Relevant personnel can obviously modify or appropriately change and combine the methods and applications described herein without departing from the content, spirit and scope of the present application to implement and apply the technology of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments.
[0045] If no specific conditions are specified in this application, the preparation shall be carried out under conventional conditions or the conditions recommended by the manufacturer. The raw materials or excipients used, as well as the reagents or instruments used, for which the manufacturers are not specified, are all conventional products that can be obtained commercially.
[0046] The application is described in detail below.
[0047] In the copper alloy film etching solution composition of the present application, the combination of ferric chloride and hydrochloric acid can complete the copper film etching, and the chelating agent is added mainly to control the deposition rate of copper ions; the inhibitor improves the clusters in the solution after etching and reduces the probability of the solution clogging the filter; the corrosion inhibitor is to better meet the etching speed requirements; the surfactant is to improve the surface wettability of the etching surface and improve the etching direction; the fluoride is to remove metals that are difficult to remove such as molybdenum, niobium, titanium, etc.
[0048] Based on the above effects, the present application provides a copper alloy film etching solution composition by mixing ferric chloride, hydrochloric acid, a chelating agent, a surfactant, a fluoride, an inhibitor, a corrosion inhibitor, a pH adjuster, etc. in a certain proportion.
[0049] In the example of the present application, when preparing the etching solution, the chelating agent, the polymerization inhibitor, and the corrosion inhibitor are first mixed and stirred for use; the ferric chloride and the hydrochloric acid are mixed and stirred; then the mixed additives are added to the mixed solution of ferric chloride and hydrochloric acid, and the surfactant and fluoride are added after stirring evenly, and the mixed solution is obtained after stirring evenly. The pH adjuster is added last, and half is added first, stirred, and then the other half is added, and stirring is continued to obtain the final solution. The pH needs to be measured and adjusted during the preparation of the etching solution.
[0050] In the copper alloy film etching solution composition of the present application, hydrochloric acid can be prepared by the following method:
[0051] Using industrial grade 37% hydrochloric acid as raw material, the preparation method comprises the following steps in sequence:
[0052] Arsenic removal: 37% industrial-grade hydrochloric acid raw material is passed into a distillation tower, and 31% high-purity hydrogen peroxide and stannous chloride are added to the distillation tower to remove arsenic by distillation;
[0053] Particle control: Use filter element to remove particles from hydrochloric acid solution after arsenic removal;
[0054] Pressure distillation: impurities are removed by pressure distillation. The pressure levels of multi-stage distillation are 0.15MPa, 0.13Mpa, and 0.11Mpa from high to low.
[0055] Tin removal: The hydrochloric acid solution used for preliminary particle removal enters a resin exchange tank containing a chelating resin, and the tin is removed by the chelating resin;
[0056] Vacuum distillation: The hydrochloric acid solution after tin removal treatment is transferred to the vacuum distillation tower to further purify the solution. The vacuum degree of multi-stage distillation increases from 0.09Mpa, 0.08Mpa, and 0.06Mpa.
[0057] Particle control: The hydrochloric acid solution treated by vacuum distillation is filtered through a multi-stage filter element to obtain the final product.
[0058] The amount of stannous chloride added can be calculated based on the chemical equation of the reaction, and the general amount is 1.05 times the standard amount. The content of hydrogen peroxide is generally 20 times the impurity content.
[0059] The resins for tin removal are Rohm and Haas IRC748, Rohm and Haas amberlite 4000CL, Zhengguang GZA351, and Lanxiao SA500U.
[0060] In the copper alloy film etching solution composition of the present application, ferric chloride can be prepared by the following method:
[0061] Preparation of ferrous chloride: react high-purity iron powder with high-purity 37% hydrochloric acid to obtain ferrous chloride;
[0062] Preparation of ferric chloride: high-purity chlorine gas is introduced into the obtained ferrous chloride solution to convert the ferrous chloride into ferric chloride;
[0063] Recrystallization: The obtained ferric chloride is made into a supersaturated solution at about 80°C, then cooled to about 20°C, and ferric chloride is obtained through a filtration system. This process can be performed multiple times according to actual conditions.
[0064] The high-purity chlorine gas is a mixture of 80% chlorine and 20% nitrogen.
[0065] The technical solution of the present application is further described below in conjunction with specific embodiments.
[0066] Example 1
[0067] The copper alloy film etching solution composition of the present application comprises the following components:
[0068]
[0069] According to the components in the above table, first mix the chelating agent, polymerization inhibitor, and corrosion inhibitor, stir for 30 minutes to obtain component 1; mix ferric chloride and hydrochloric acid, stir for 30 minutes to obtain component 2; mix component 1 and component 2, stir for 30 minutes, add surfactant and fluoride, and continue stirring for 30 minutes to obtain a mixed solution. Add half of the pH adjuster to the mixed solution and stir for 10 minutes, then add the remaining pH adjuster and stir for 10 minutes to obtain the final solution.
[0070] Example 2
[0071] The copper alloy film etching solution composition of the present application comprises the following components (preparation method is the same as in Example 1):
[0072]
[0073] Example 3
[0074] The copper alloy film etching solution composition of the present application comprises the following components (preparation method is the same as in Example 1):
[0075]
[0076]
[0077] Example 4
[0078] The copper alloy film etching solution composition of the present application comprises the following components (preparation method is the same as in Example 1):
[0079]
[0080] Example 5
[0081] The copper alloy film etching solution composition of the present application comprises the following components (preparation method is the same as in Example 1):
[0082]
[0083] Example 6
[0084] The copper alloy film etching solution composition of the present application comprises the following components (preparation method is the same as in Example 1):
[0085]
[0086]
[0087] Example 7
[0088] The copper alloy film etching solution composition of the present application comprises the following components (preparation method is the same as in Example 1):
[0089]
[0090] Example 8
[0091] The copper alloy film etching solution composition of the present application comprises the following components (preparation method is the same as in Example 1):
[0092]
[0093]
[0094] Example 9
[0095] The copper alloy film etching solution composition of the present application comprises the following components (preparation method is the same as in Example 1):
[0096]
[0097]
[0098] Comparative Example 1
[0099] A copper alloy film etching solution composition comprises the following components:
[0100] Element content Ferric chloride 28wt% hydrochloric acid 12wt%
[0101] Comparative Example 2
[0102] A copper alloy film etching solution composition comprises the following components:
[0103]
[0104] Comparative Example 3
[0105] A copper alloy film etching solution composition comprises the following components:
[0106]
[0107]
[0108] Comparative Example 4
[0109] A copper alloy film etching solution composition comprises the following components:
[0110]
[0111] Comparative Example 5 A copper alloy film etching solution composition, the components and contents are the same as those in Example 1, and the preparation method is as follows:
[0112] Ferric chloride and hydrochloric acid were mixed and stirred for 30 minutes to obtain a mixed solution. A chelating agent, an inhibitor, a corrosion inhibitor, a surfactant, a fluoride and a pH adjuster were added to the mixed solution and the mixture was stirred for 60 minutes to obtain a final solution.
[0113] Comparative Example 6
[0114] A copper alloy film etching solution composition, the preparation method is the same as that of Example 1, and the components and contents thereof are different from those of Example 1 in that the fluoride is hydrofluoric acid.
[0115] Experimental example
[0116] The etching solutions of the above embodiments and comparative examples were subjected to performance tests.
[0117] Test method:
[0118] Copper film surface precipitation: mainly observed by electron microscope to observe the percentage of surface particles occupying the copper film per unit area.
[0119] Filter clogging degree: The volume of solution passing through the filter per unit time indicates the degree of filter clogging.
[0120] Copper film etching rate: Observe the cross section of the copper film through an electron microscope, and the change in the cross section divided by time is the copper film etching rate.
[0121] Surface roughness of copper film: The difference between the highest point and the lowest point on the surface of the copper film per unit area is divided by the length, and then the obtained value is squared.
[0122] Copper loading: Add copper powder to a fixed mass solution until the copper powder just begins to become insoluble. Calculate the percentage of copper ions in the solution based on the mass of copper powder added.
[0123] Other metal residues: Use a scanning electron microscope to observe the interface between the copper film and other metals to confirm the metal residues.
[0124] according to Figure 1 and Figure 2 The value of can be calculated as etching rate = (copper film thickness before etching - copper film thickness after etching) / etching time.
[0125] according to Figure 1 and Figure 2 , we can calculate the roughness = [(highest point - lowest point) / unit length] 2 .
[0126] Figure 3 , Figure 4 This is the surface morphology of the copper foil before etching according to an exemplary embodiment of the present application. Figure 5-Figure 8 The surface morphology of the copper foil after etching in the exemplary embodiment of the present application is shown in FIG. Figure 5-8 visible, Figure 5 and Figure 6 It is the surface morphology of the copper foil after etching (no surface residue); Figure 7 and Figure 8 The surface morphology of the copper foil after etching (surface residue)
[0127] The test results are shown in Table 1 below.
[0128] Table 1
[0129]
[0130]
[0131] According to the data in the above table, it can be seen that the copper alloy film etching solution composition of the present application has a better etching rate and better etching morphology, can reduce particle clusters, and reduce the probability of filter clogging.
[0132] The description of the above embodiments is only used to help understand the method and core idea of the present application. It should be noted that, for ordinary technicians in this technical field, several improvements and modifications can be made to the present application without departing from the principles of the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.
Claims
1. A copper alloy film etching solution composition, characterized in that The copper alloy film etching solution composition comprises the following components: Ferric chloride: 21-30wt%; Hydrochloric acid: 10-18wt%; Chelating agent: 0-12wt%; Surfactant: 0-0.5wt%; Fluoride: 0-1wt%; Inhibitor: 0-0.5wt%; Corrosion inhibitor: 0-0.6wt%; pH regulator: 0-3wt%; Ultrapure water: balance; Wherein, the fluoride is selected from: a mixture of ammonium bifluoride and perfluoropolyether carboxylic acid propylene oxide ammonium.
2. The copper alloy film etching solution composition according to claim 1, characterized in that The copper alloy film etching solution composition comprises the following components: Ferric chloride: 23-28wt%; Hydrochloric acid: 12-16wt%; Chelating agent: 7-12wt%; Surfactant: 0.2-0.4wt%; Fluoride: 0.03-0.05wt%; Inhibitor: 0.1-0.2wt%; Corrosion inhibitor: 0.3-0.5wt%; pH regulator: 1-2wt%; Ultrapure water: balance.
3. The copper alloy film etching solution composition according to claim 1 or 2, characterized in that The chelating agent is selected from: ethylenediaminetetraacetic acid and / or hydroxyethylidene diphosphonic acid.
4. The copper alloy film etching solution composition according to claim 1 or 2, characterized in that: The surfactant is selected from: fatty alcohol polyoxyethylene ether and / or hexadecyl trimethyl ammonium chloride.
5. The copper alloy film etching solution composition according to claim 1 or 2, characterized in that: The perfluoropolyether carboxylic acid propylene oxide ammonium is [CF(CF3)CF2O)] n COONHCH2CHCH2O, n = 5-10; Optionally, the mass ratio of the ammonium bifluoride to the perfluoropolyether carboxylic acid propylene oxide ammonium is 1:(2-10); Further optionally, the mass ratio is 1:
2.
6. The copper alloy film etching solution composition according to claim 1 or 2, characterized in that: The polymerization inhibitor is selected from one or more of N-nitrosodiphenylamine, o-methyl-p-benzoquinone, and 5-nitroso-8-hydroxyquinoline.
7. The copper alloy film etching solution composition according to claim 1 or 2, characterized in that: The corrosion inhibitor is selected from: benzotriazole and / or 5-methyltetrazolyl.
8. The copper alloy film etching solution composition according to claim 1 or 2, characterized in that: The pH regulator is selected from one or more of 2,6-di-tert-butyl-p-methylphenol, acrylamide, triethanolamine, 2-amino-2-methyl-1-propanol and n-butylphenylpropionamide.
9. The copper alloy film etching solution composition according to claim 1 or 2, characterized in that: The pH regulator is a 1:1 mixture of pH regulator and wetting agent; Optionally, the wetting agent is selected from TEGO surten 202E, 232E or W111.
10. A method for preparing the copper alloy film etching solution composition according to any one of claims 1 to 9, characterized in that: include: Mixing and stirring the chelating agent, the polymerization inhibitor, and the corrosion inhibitor to obtain a first additive component; Mixing ferric chloride and hydrochloric acid and stirring to obtain a ferric chloride / hydrochloric acid mixture; Adding the first additive component to the ferric chloride / hydrochloric acid mixture, stirring evenly, and then adding a surfactant and a fluoride, mixing to obtain a mixed solution; A pH regulator is added to the mixed solution in batches to obtain the copper alloy film etching solution composition.