A copper suspension removing solution for IC carrier plate, a preparation method thereof and a copper suspension removing method

Abstract

The application discloses IC carrier plate copper suspension removing liquid and a preparation method and a removing method thereof, and relates to the technical field of IC carrier plate manufacturing. The IC carrier plate copper suspension removing liquid comprises the following raw material components in mass concentration: bite corrosion agent 4.0-6.0%, surfactant 0.2-0.6%, selective copper suspension dissolving agent 0.5-1.0%, selective copper surface corrosion inhibitor 0.5-1.0%, and complexing agent 0.2-1.0%. The IC carrier plate copper suspension removing liquid selectively dissolves the suspended copper and selectively corrodes the copper surface, improves the bite corrosion rate ratio of the two, and realizes the effect of completely removing the suspended copper.

Description

Technical Field

[0001] This invention relates to the field of IC substrate manufacturing technology, and in particular to an IC substrate copper removal solution, its preparation method, and the copper removal method. Background Technology

[0002] Against the backdrop of the rapid development of the current electronics and information industry, IC substrates, as key basic components that carry electronic components and realize circuit connections, have gradually expanded their application scope from traditional consumer electronics to high-tech fields such as 5G communication, artificial intelligence, and autonomous driving. These high-end applications place extremely stringent requirements on the precision, reliability, and stability of IC substrates—especially in processes such as high-density interconnects, micro-apertures, and ultra-thin substrates, any processing deviation can directly cause the failure of the entire electronic device.

[0003] In IC substrate manufacturing, suspended copper is a common and challenging problem. Suspended copper refers to residual copper that remains in a "suspended" state due to uneven etching solution distribution, inaccurate parameter control, or insufficient substrate surface pretreatment during the etching process. This results in some copper foil not being completely removed, or its adhesion to the substrate decreasing. This suspended copper not only occupies effective wiring area on the substrate, interfering with signal transmission and causing delays and crosstalk, but more seriously, it is prone to detachment during subsequent soldering, packaging, and even end-use, leading to fatal failures such as short circuits and component damage, significantly impacting the yield and lifespan of the IC substrate.

[0004] Currently, the industry mainly relies on two methods to remove suspended copper: traditional etching solutions and physical polishing. Traditional etching solutions can remove excess copper foil to some extent, but they have poor selectivity and can easily cause over-etching of normal circuits, affecting the precision of fine lines and even damaging the circuit structure. In addition, some etching solutions contain highly corrosive components or heavy metal ions, making waste liquid treatment difficult and failing to meet green manufacturing requirements. Physical polishing methods have drawbacks such as low efficiency and difficulty in precision control, and can easily cause mechanical damage to the substrate surface. Therefore, they have limited applicability in the processing of ultra-thin, high-precision IC substrates.

[0005] Some existing patents describe methods for removing suspended copper using etching solutions. Patent CN117070948B describes a solution and method for removing suspended copper from circuit boards. Its main components are: hydrogen peroxide stabilizer 5-20 g / L, suspended copper etching accelerator 105-155 g / L, surface copper etching inhibitor 0.1 g-20 g / L, sulfuric acid 5 g-100 g / L, and hydrogen peroxide 10-50 g / L. This solution improves system stability; while etching the copper layer, it adsorbs around the suspended copper, removing it and resulting in a smooth etched hole with a diameter consistent with the drilled hole diameter. Patent CN117956692B discloses an alkaline copper removal solution for circuit boards and its preparation and removal methods. Its main components are: ammonium chloride 3-20 g / L, ammonium bicarbonate 0.2-2 g / L, industrial ammonia 5-15 g / L, wetting agent 0.2-2 g / L, copper surface protectant 5-20 g / L, copper removal accelerator 0.2-2 g / L, and catalyst 0.5-3 g / L. The mass ratio of copper surface protectant to copper removal accelerator is 1:(0.02-0.3). This copper removal solution can quickly remove large copper splashes from the edges of blind vias. The functional groups in the solution adsorb around the suspended copper, removing only the suspended copper without corroding the copper surface. Furthermore, using an alkaline solution instead of an acidic solution significantly improves the quality and yield, and the operation is simple and convenient.

[0006] Existing etching solutions for removing suspended copper are effective for general PCB board materials with wide / spacing designs. However, with the continuous development of IC substrates and the decreasing size of PCB holes, a ratio of suspended copper etching rate to surface copper etching rate greater than 6.0 is required for complete removal, which is difficult to achieve with current technologies. Furthermore, existing technologies have low tolerance for copper ion concentration; the etching rate decreases significantly as copper ion concentration increases. Therefore, developing a copper removal solution with high selectivity, high copper capacity, and excellent environmental performance is of great practical significance for solving the suspended copper problem in current IC substrate production, improving overall product quality, and meeting the stringent requirements of high-end electronics. It also aligns with the industry's trend towards green and precision manufacturing. Summary of the Invention

[0007] To address the shortcomings of existing technologies, this invention provides an IC substrate copper removal solution, its preparation method, and its application method. This solution is used in the copper removal process of IC substrates. The copper removal solution contains effective components such as an etching agent, surfactant, selective copper dissolving agent, selective surface copper etching inhibitor, and complexing agent. By selectively dissolving the suspended copper and selectively etching the surface copper, the etching rate ratio between the two is increased, achieving the effect of completely removing the suspended copper.

[0008] The etching agent in this component is the main substance for etching copper, achieving the basic etching function. This type of etching agent was chosen because its reaction is controllable, its byproducts are easy to handle, and it is more selective than the sulfuric acid / hydrogen peroxide system. The surfactant mainly serves to reduce surface tension and promote penetration. The selective copper suspension solvent preferentially and rapidly attacks and removes suspended copper, while having an extremely low dissolution rate on normal surface copper that is tightly bonded to the substrate. The selective surface copper etching inhibitor forms a dense and stable adsorption film on the surface copper, blocking the contact between the solvent and the surface copper without affecting the dissolution of suspended copper. The complexing agent is used to efficiently complex the Cu generated in the reaction. 2+ This maintains the stability of the solution's lifespan and etching rate under high copper ion concentrations.

[0009] Specifically, an IC substrate copper desuspension solution is provided, comprising the following raw material components by mass concentration:

[0010] Etching agent 4.0-6.0%,

[0011] Surfactant 0.2-0.6%,

[0012] Selective copper suspension solvent 0.5-1.0%,

[0013] Selective copper corrosion inhibitor 0.5-1.0%,

[0014] Complexing agent 0.2-1.0%;

[0015] The etching agent is selected from one or a mixture of more than one of hydrogen peroxide urea (CAS No.: 124-43-6), benzoic acid peroxide (CAS No.: 94-36-0), and diethylpropylbenzene peroxide (CAS No.: 80-43-3);

[0016] The surfactant is selected from one or a mixture of more of the following: 3-chloro-2-methylphenyl methyl sulfide (CAS No.: 82961-52-2), 2-chloroethyl ethyl sulfide (CAS No.: 693-07-2), and bis(4-chloro-2-nitrophenyl) disulfide (CAS No.: 2050-66-0);

[0017] The selective copper suspension solvent is selected from one or a mixture of more of the following: 2-aminobenzophenone oxime (CAS No.: 51674-05-6), 4-amino-1,2,5-oxadiazole-3-chloroformaldehyde oxime (CAS No.: 147085-13-0), and 4-aminobenzamide oxime (CAS No.: 277319-62-7);

[0018] The selective copper corrosion inhibitor is selected from one or a mixture of more of the following: 5,6-diphenyl-3-hydroxy-1,2,4-triazine (CAS No.: 4512-00-9), 2,4,6-tris(4-butoxy-2-hydroxyphenyl)-1,3,5-triazine (CAS No.: 3135-19-1), and 2,4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine (CAS No.: 2125-23-7).

[0019] The complexing agent is selected from one or a mixture of more of (2S,3R)-3-amino-2-hydroxy-4-phenylbutyric acid (CAS No.: 59554-14-2), N-(2-mercapto-1-oxopropyl)glycine (CAS No.: 1953-02-2), and 2-mercaptoisobutyric acid (CAS No.: 4695-31-2).

[0020] Preferably, the IC substrate copper desuspension solution is composed of the following raw material components by mass concentration:

[0021] Etching agent 4.0-6.0%,

[0022] Surfactant 0.2-0.6%,

[0023] Selective copper suspension solvent 0.5-1.0%,

[0024] Selective copper corrosion inhibitor 0.5-1.0%,

[0025] Complexing agent 0.2-1.0%;

[0026] The remainder is water.

[0027] Preferably, the water can be tap water or deionized water.

[0028] In some specific embodiments, the IC substrate copper desuspension solution is composed of the following raw material components by mass concentration:

[0029] Etching agent 5.0%,

[0030] Surfactant 0.4%,

[0031] Selective copper suspension solvent 0.8%,

[0032] Selective copper corrosion inhibitor 0.8%,

[0033] Complexing agent 0.6%;

[0034] The remainder is water.

[0035] The present invention also provides a method for preparing the above-mentioned IC substrate copper removal solution. Specifically, according to the mass concentration of each component, the etching agent, surfactant, selective copper suspension dissolving agent, selective surface copper corrosion inhibitor, complexing agent and the balance water are weighed and mixed evenly at room temperature to obtain the IC substrate copper removal solution.

[0036] The present invention also provides a method for removing suspended copper, specifically, the above-mentioned copper removal solution for IC substrate is prepared as an aqueous solution with a mass concentration of 8.0-15.0%, and sprayed onto the etched IC substrate.

[0037] Preferably, the spray pressure is 1.5 ± 0.2 kg / cm². 2 Spraying time: 30±6 seconds.

[0038] Preferably, the copper removal method specifically involves preparing the copper removal solution for the IC substrate into an aqueous solution with a mass concentration of 10.0%, and spraying it onto the etched IC substrate.

[0039] In some specific embodiments, the above-mentioned copper removal method can be carried out in the copper removal section of the copper removal process. Specifically, the etched IC substrate enters the copper removal section, and the copper removal tank uses an aqueous solution prepared with the above-mentioned IC substrate copper removal solution. The process parameters of the copper removal section are: spray method, tank temperature 35±1℃, copper removal section length 1.0m; linear velocity 2.0±0.1m / min, pressure 1.5±0.2kg / cm 2 .

[0040] Furthermore, the copper removal process further includes a high-pressure water washing section, a water washing section, and a drying section after the copper removal stage; the high-pressure water washing section uses a spray method with a spray pressure of 1.5±0.5 kg / cm². 2 The washing section uses an immersion method; the drying temperature of the drying section is 70±5℃.

[0041] Preferably, the spraying time of the high-pressure water washing section is 30±6S; the soaking time of the water washing section is 30±5S.

[0042] The IC substrate copper removal solution of the present invention improves the etching rate ratio of the two by selectively dissolving the suspended copper and selectively inhibiting the etching of the surface copper, thereby achieving the effect of completely removing the suspended copper. Attached Figure Description

[0043] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 Metallographic microscope image of the copper suspension test board after treatment with the copper suspension solution of IC carrier in Example 1;

[0045] Figure 2 This is a cross-sectional view of the copper suspension test board after it has been treated with the copper suspension removal solution of the IC carrier board in Example 1.

[0046] Figure 3 Metallographic microscope image of the copper suspension test plate after treatment with the copper suspension removal solution of Comparative Example 16.

[0047] Figure 4 This is a slice of the copper suspension test board after it has been treated with the copper suspension removal solution of Comparative Example 16. Detailed Implementation

[0048] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0049] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0050] In the following examples and comparative examples, all contents refer to mass content.

[0051] Example 1:

[0052] Weigh out the following components in sequence: etching agent, surfactant, selective copper suspension dissolving agent, selective surface copper corrosion inhibitor, complexing agent, and the remaining water, and add them to the reaction vessel. Stir and mix at room temperature for 30 minutes to obtain the copper suspension removal solution. Store the solution in a sealed container for later use.

[0053] The etching agent content is 5.0%, specifically: hydrogen peroxide urea;

[0054] The surfactant content is 0.4%, specifically: 3-chloro-2-methylphenyl methyl sulfide;

[0055] The selective copper suspension solvent content is 0.8%, specifically 2-aminobenzophenone oxime;

[0056] The selective copper corrosion inhibitor content is 0.8%, specifically 5,6-diphenyl-3-hydroxy-1,2,4-triazine;

[0057] The complexing agent content is 0.6%, specifically (2S,3R)-3-amino-2-hydroxy-4-phenylbutyric acid;

[0058] The remainder is water.

[0059] Example 2:

[0060] Weigh out the following components in sequence: etching agent, surfactant, selective copper suspension dissolving agent, selective surface copper corrosion inhibitor, complexing agent, and the remaining water, and add them to the reaction vessel. Stir and mix at room temperature for 30 minutes to obtain the copper suspension removal solution. Store the solution in a sealed container for later use.

[0061] The etching agent content is 5.0%, specifically: benzoic acid peroxide;

[0062] The surfactant content is 0.4%, specifically: 2-chloroethyl ethyl sulfide;

[0063] The selective copper suspension solvent content is 0.8%, specifically 4-amino-1,2,5-oxadiazole-3-chloroformaldehyde oxime;

[0064] The selective copper corrosion inhibitor content is 0.8%, specifically 2,4,6-tris(4-butoxy-2-hydroxyphenyl)-1,3,5-triazine;

[0065] The complexing agent content is 0.6%, specifically N-(2-mercapto-1-oxopropyl)glycine;

[0066] The remainder is water.

[0067] Example 3:

[0068] Weigh out the following components in sequence: etching agent, surfactant, selective copper suspension dissolving agent, selective surface copper corrosion inhibitor, complexing agent, and the remaining water, and add them to the reaction vessel. Stir and mix at room temperature for 30 minutes to obtain the copper suspension removal solution. Store the solution in a sealed container for later use.

[0069] The etching agent content is 5.0%, specifically: diethylpropylbenzene peroxide;

[0070] The surfactant content is 0.4%, specifically: bis(4-chloro-2-nitrophenyl) disulfide;

[0071] The selective copper suspension solvent content is 0.8%, specifically 4-aminobenzamide oxime;

[0072] The selective copper corrosion inhibitor content is 0.8%, specifically 2,4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine;

[0073] The complexing agent content is 0.6%, specifically 2-mercaptoisobutyric acid;

[0074] The remainder is water.

[0075] Example 4:

[0076] Weigh out the following components in sequence: etching agent, surfactant, selective copper suspension dissolving agent, selective surface copper corrosion inhibitor, complexing agent, and the remaining water, and add them to the reaction vessel. Stir and mix at room temperature for 30 minutes to obtain the copper suspension removal solution. Store the solution in a sealed container for later use.

[0077] The etching agent content is 4.0%, specifically: hydrogen peroxide urea;

[0078] The surfactant content is 0.2%, specifically: 3-chloro-2-methylphenyl methyl sulfide;

[0079] The selective copper suspension solvent content is 0.5%, specifically 2-aminobenzophenone oxime;

[0080] The selective copper corrosion inhibitor content is 0.5%, specifically 5,6-diphenyl-3-hydroxy-1,2,4-triazine;

[0081] The complexing agent content is 0.2%, specifically (2S,3R)-3-amino-2-hydroxy-4-phenylbutyric acid;

[0082] The remainder is water.

[0083] Example 5:

[0084] Weigh out the following components in sequence: etching agent, surfactant, selective copper suspension dissolving agent, selective surface copper corrosion inhibitor, complexing agent, and the remaining water, and add them to the reaction vessel. Stir and mix at room temperature for 30 minutes to obtain the copper suspension removal solution. Store the solution in a sealed container for later use.

[0085] The etching agent content is 6.0%, specifically: hydrogen peroxide urea;

[0086] The surfactant content is 0.6%, specifically: 3-chloro-2-methylphenyl methyl sulfide;

[0087] The selective copper suspension solvent content is 1.0%, specifically 2-aminobenzophenone oxime;

[0088] The selective copper corrosion inhibitor content is 1.0%, specifically 5,6-diphenyl-3-hydroxy-1,2,4-triazine;

[0089] The complexing agent content is 1.0%, specifically (2S,3R)-3-amino-2-hydroxy-4-phenylbutyric acid;

[0090] The remainder is water.

[0091] Comparative Example 1

[0092] The only difference between Comparative Example 1 and Example 1 is that the components do not contain an etching agent.

[0093] Comparative Example 2

[0094] The only difference between Comparative Example 2 and Example 1 is that the components do not contain surfactants.

[0095] Comparative Example 3

[0096] The only difference between Comparative Example 3 and Example 1 is that the components do not contain a selective copper suspension solvent.

[0097] Comparative Example 4

[0098] The only difference between Comparative Example 4 and Example 1 is that the composition does not contain a selective copper surface corrosion inhibitor.

[0099] Comparative Example 5

[0100] The only difference between Comparative Example 5 and Example 1 is that the components do not contain a complexing agent.

[0101] Comparative Example 6

[0102] The only difference between Comparative Example 6 and Example 1 is that the concentration of the etching agent in the component is 10.0%.

[0103] Comparative Example 7

[0104] The only difference between Comparative Example 7 and Example 1 is that the surfactant concentration in the component is 1.2%.

[0105] Comparative Example 8

[0106] The only difference between Comparative Example 8 and Example 1 is that the concentration of selective copper suspension solvent in the component is 2.0%.

[0107] Comparative Example 9

[0108] The only difference between Comparative Example 9 and Example 1 is that the concentration of selective copper corrosion inhibitor in the component is 2.0%.

[0109] Comparative Example 10

[0110] The only difference between Comparative Example 10 and Example 1 is that the concentration of the complexing agent in the component is 2.0%.

[0111] Comparative Example 11

[0112] The only difference between Comparative Example 11 and Example 1 is that the etching agent component, hydrogen peroxide urea, is replaced with an equal mass of sodium persulfate (CAS No.: 7775-27-1).

[0113] Comparative Example 12

[0114] The only difference between Comparative Example 12 and Example 1 is that the surfactant component 3-chloro-2-methylphenyl methyl sulfide was replaced with an equal mass of methylphenyl sulfide (CAS No.: 100-68-5).

[0115] Comparative Example 13

[0116] The only difference between Comparative Example 13 and Example 1 is that the selective copper suspension solvent component, 2-aminobenzophenone oxime, is replaced with an equal mass of (E)-benzophenone oxime (CAS No.: 101-91-7).

[0117] Comparative Example 14

[0118] The only difference between Comparative Example 14 and Example 1 is that the selective copper corrosion inhibitor component, 5,6-diphenyl-3-hydroxy-1,2,4-triazine, is replaced with an equal mass of 1,3,5-triazine (CAS No.: 290-87-9).

[0119] Comparative Example 15

[0120] The only difference between Comparative Example 15 and Example 1 is that the complexing agent component is: disodium ethylenediaminetetraacetate (CAS No.: 139-33-3) by mass of (2S,3R)-3-amino-2-hydroxy-4-phenylbutyric acid.

[0121] Comparative Example 16

[0122] Comparative Example 16 is a copper desuspension solution disclosed in the prior art (Chinese Patent Application CN117956692B). Specifically, its components include: 10 g / L ammonium chloride; 1.0 g / L ammonium bicarbonate; 10 g / L industrial ammonia; 1.0 g / L sodium polyacrylate; 10 g / L dicyclohexylamine nitrite; 0.8 g / L tetraethyl titanate; 1.2 g / L trioctylmethylammonium chloride; and the balance being deionized water.

[0123] Performance testing

[0124] The copper removal process in the following performance testing includes the following steps: S1 Feeding; S2 Copper removal; S3 High-pressure water washing; S4 Water washing; S5 Drying;

[0125] The S1 feeding section is for placing the test board that needs to be desuspended copper. The process parameters of the feeding section are: feeding section length 1.0m, temperature 25±1℃, and linear speed 3.0±0.2m / min.

[0126] The S2 desuspension copper section is used to desuspension copper from the test board that has passed through the S1 feeding section. The desuspension copper section uses the desuspension copper solution prepared in the example / comparative example, with a chemical addition ratio of 10% and the remainder being tap water. The process parameters for the desuspension copper section are: spray method, tank temperature 35±1℃, section length 1.0m, linear velocity 2.0±0.1m / min, and spray pressure 1.5±0.2kg / cm². 2 ;

[0127] The S3 high-pressure water washing section is used to wash the test board that has passed through the S2 copper removal section with tap water. The process parameters for the high-pressure water washing section are as follows: this section uses a spray method, the water washing tank temperature is 25±5℃, the length of the water washing section is 2.0m, the linear velocity is 4.0±0.2m / min, and the spray pressure is 1.5±0.5kg / cm. 2 ;

[0128] The S4 water washing section is used to wash the test plate that has passed through the S3 high-pressure water washing section with tap water. The process parameters of the water washing section are as follows: the section is immersed, the temperature is 25±5℃, the length of the water washing section is 1.0m, and the linear velocity is 2.0±0.2m / min.

[0129] The S5 drying section dries the test plates after the S4 washing section. The drying process parameters are: temperature 70±5℃, drying section length 4.0 m, and linear speed 2.0±0.3 m / min.

[0130] The performance of copper removal solutions is mainly studied from two aspects: the ratio of the etching rate of suspended copper to that of surface copper and the resistance to copper ion concentration.

[0131] 1) The etching method is used to test the etching rate, including the etching rate of suspended copper and the etching rate of surface copper.

[0132] Test method for copper etching rate: Take a piece of ordinary copper-clad laminate with a length and width of 4cm*5cm and a copper thickness of 5μm as the test board, and weigh it before the test using an electronic balance; process the ordinary copper-clad laminate according to the above-mentioned copper removal process, and record the etching time (min) of the copper removal section; weigh the ordinary copper-clad laminate after the test; the copper etching rate is weight difference * 28 / etching time, in μm / min.

[0133] The etching rate method for suspended copper is the same as above, except that the test board is replaced with a suspended copper-specific test board of the same size and copper thickness.

[0134] The test results require that the ratio of the suspended copper etching rate to the surface copper etching rate be greater than 6.0.

[0135] 2) Copper ion concentration resistance test method: Take the copper desuspension solution of IC substrate in Example 1, and adjust the copper ion concentration by adding different amounts of copper sulfate. Test the etching rate of the test board at different copper ion concentrations.

[0136] The requirement is that when the copper ion concentration reaches 80 g / L, the etching rates of suspended copper, surface copper, and the ratio of the etching rates of suspended copper to surface copper remain essentially unchanged.

[0137] The performance test results of Examples 1-5 and Comparative Examples 1-16 are shown in Table 1 below:

[0138] Table 1. Test results of erosion rate performance of Examples 1-5 and Comparative Examples 1-16

[0139]

[0140] The observation results of the copper suspension test board after treatment with the copper suspension removal solution of the IC carrier in Example 1 are as follows: Figure 1 As shown; the cross-sectional observation results of the copper suspension test board after treatment with the copper suspension solution of the IC carrier in Example 1 are as follows. Figure 2 As shown; the observation results of the copper suspension test board after treatment with the copper suspension removal solution of Comparative Example 16 are as follows. Figure 3 As shown; the observation results of the slices of the copper suspension test board after treatment with the copper desuspension solution of Comparative Example 16 are as follows. Figure 4 As shown.

[0141] The etching rate test results of the IC substrate copper desuspension solution in Example 1 at different copper contents are shown in Table 2 below:

[0142] Table 2. Test results of etching rate under different copper contents in Example 1

[0143]

[0144] As can be seen from the experimental data of Examples 1-5 in Table 1, the IC substrate copper removal solution of the present invention has excellent copper removal performance, wherein the copper removal rate is >5.2345μm / min, the surface copper removal rate is >0.8028μm / min, and the copper removal rate / surface copper rate is >6.45, which meets the technical process requirements for copper removal from IC substrates.

[0145] The difference between Comparative Examples 1-5 and Example 1 is that the copper removal solution of this invention lacks a single component of etching agent, surfactant, selective copper suspension dissolver, selective surface copper corrosion inhibitor, and complexing agent, respectively. Experimental data show that the etching agent is the main active substance for etching copper; when the etching agent is absent from the system, the etching rate of both suspended and surface copper is significantly reduced. The surfactant mainly reduces surface tension and promotes penetration, which helps improve the uniformity of etching and can also appropriately increase the etching rate. The selective copper suspension dissolver is used to increase the etching rate of suspended copper and the ratio of suspended copper rate to surface copper rate. The selective surface copper corrosion inhibitor is used to reduce the etching rate of surface copper and can also increase the ratio of suspended copper rate to surface copper rate. The complexing agent mainly complexes and shields metal ions; when the complexing agent is absent, the etching rate decreases.

[0146] The difference between Comparative Examples 6-10 and Example 1 lies in the concentration limits of the etching agent, surfactant, selective copper suspension dissolver, selective surface copper corrosion inhibitor, and complexing agent in the copper suspension solution, all of which are higher than the upper limits of the anti-diffusion solution of this invention. Experimental data show that, compared to Examples 1-5, a higher concentration of the etching agent will increase the etching rate of both suspended and surface copper; the ratio between the two needs to be controlled to be >6.0. Higher concentrations of surfactant, selective copper suspension dissolver, selective surface copper corrosion inhibitor, and complexing agent have a slight impact on the etching rate, but the etching rates of both suspended and surface copper are generally sufficient. From a cost perspective, excessively high concentrations will increase the cost of the solution; therefore, the concentrations of these four components in the copper suspension removal solution of this invention should not be too high, and the stable effect of the solution can be ensured within the concentration range of the examples.

[0147] The difference between Comparative Examples 11-15 and Example 1 is that the etching agent, surfactant, selective copper suspension dissolving agent, selective surface copper corrosion inhibitor, complexing agent, etc. are replaced with compounds of similar structure / similar function in equal mass. Experimental data show that the functional components of different types of branched groups also affect the copper suspension removal performance, making it difficult to meet the copper suspension removal requirements of the IC substrate of this invention.

[0148] A comparison of experimental data between the copper suspension removal solution of the prior art (Chinese patent application CN 117956692 B) in Comparative Example 16 and the copper suspension removal solution of the present invention shows that the copper suspension rate / surface copper rate ratio of the copper suspension solution of the present invention is better, and it can completely remove residual copper suspension.

[0149] As can be seen from the experimental data in Table 2, the copper removal solution of the present invention exhibits small fluctuations in the copper ion concentration at 0-80 g / L, including the copper ion etching rate, surface copper ion etching rate, and the ratio of copper ion etching rate to surface copper ion etching rate, indicating that the solution has a strong resistance to copper ions. When the copper ion concentration is 90-100 g / L, the copper ion etching rate and surface copper ion etching rate show slight changes, but the ratio of copper ion etching rate to surface copper ion etching rate is still >6.0, meeting the actual requirements.

[0150] In summary, the preparation method and usage method of the copper removal solution for IC substrates provided by this invention can be used in the copper removal process of IC substrates. The copper removal solution contains effective components such as etching agents, surfactants, selective copper dissolving agents, selective surface copper etching inhibitors, and complexing agents. By selectively dissolving the suspended copper and selectively etching the surface copper, the etching rate ratio between the two is improved, achieving the effect of completely removing the suspended copper. At the same time, the copper removal solution of this invention has extremely strong copper ion resistance, which can maintain the stability of the solution's lifespan and etching rate under high copper ion concentrations.

[0151] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present invention, and these modifications or substitutions should all be covered within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for removing suspended copper, performed in the copper removal section of a copper removal process, characterized in that, The copper removal solution for the IC substrate was prepared as an aqueous solution with a mass concentration of 8.0-15.0%, and sprayed onto the etched IC substrate. Specifically, the etched IC substrate entered the copper removal section, where the aqueous solution was used. The process parameters for the copper removal section were: spraying method, copper removal tank temperature 35±1℃, copper removal section length 1.0m, linear velocity 2.0±0.1m / min, and pressure 1.5±0.2kg / cm². 2 ; The IC carrier copper desuspension solution comprises the following raw material components by mass concentration: Etching agent 4.0-6.0%, Surfactant 0.2-0.6%, Selective copper suspension solvent 0.5-1.0%, Selective copper corrosion inhibitor 0.5-1.0%, Complexing agent 0.2-1.0%; The etching agent is selected from one or a mixture of more than one of hydrogen peroxide urea, benzoic acid peroxide, and diethylpropylbenzene peroxide; The surfactant is selected from one or a mixture of more than one of 3-chloro-2-methylphenyl methyl sulfide, 2-chloroethyl ethyl sulfide, and bis(4-chloro-2-nitrophenyl) disulfide; The selective copper suspension solvent is selected from one or a mixture of more of the following: 2-aminobenzophenone oxime, 4-amino-1,2,5-oxadiazole-3-chloroformaldehyde oxime, and 4-aminobenzamide oxime. The selective copper corrosion inhibitor is selected from one or a mixture of more than one of 5,6-diphenyl-3-hydroxy-1,2,4-triazine, 2,4,6-tris(4-butoxy-2-hydroxyphenyl)-1,3,5-triazine, and 2,4,6-tris(2,4-dihydroxyphenyl)-1,3,5-triazine. The complexing agent is selected from one or a mixture of more of (2S,3R)-3-amino-2-hydroxy-4-phenylbutyric acid, N-(2-mercapto-1-oxopropyl)glycine, and 2-mercaptoisobutyric acid.

2. The method for removing suspended copper according to claim 1, characterized in that, The IC carrier copper desuspension solution is composed of the following raw material components at the following mass concentrations: Etching agent 4.0-6.0%, Surfactant 0.2-0.6%, Selective copper suspension solvent 0.5-1.0%, Selective copper corrosion inhibitor 0.5-1.0%, Complexing agent 0.2-1.0%; The remainder is water.

3. The method for removing suspended copper according to claim 1, characterized in that, The IC carrier copper desuspension solution is composed of the following raw material components at the following mass concentrations: Etching agent 5.0%, Surfactant 0.4%, Selective copper suspension solvent 0.8%, Selective copper corrosion inhibitor 0.8%, Complexing agent 0.6%; The remainder is water.

4. The method for removing suspended copper as described in any one of claims 1-3, characterized in that, The preparation method of the copper desuspension solution for the IC carrier is as follows: According to the mass concentration of each component, weigh out the etching agent, surfactant, selective copper suspension dissolving agent, selective surface copper corrosion inhibitor, complexing agent and the balance water, and mix them evenly at room temperature to obtain the IC substrate copper suspension removal solution.

5. The method for removing suspended copper according to claim 1, characterized in that, The spray pressure is 1.5 ± 0.2 kg / cm². 2 Spraying time: 30±6 seconds.

6. The method for removing suspended copper according to claim 1, characterized in that, The copper suspension solution for the IC substrate was prepared as an aqueous solution with a mass concentration of 10.0%, and sprayed onto the etched IC substrate.

7. The method for removing suspended copper according to claim 1, characterized in that, Following the copper removal section, the system includes a high-pressure water washing section, a water washing section, and a drying section; the high-pressure water washing section uses a spray method with a spray pressure of 1.5 ± 0.5 kg / cm². 2 The washing section uses an immersion method; the drying temperature of the drying section is 70±5℃.

8. The method for removing suspended copper according to claim 7, characterized in that, The spraying time of the high-pressure water washing section is 30±6 seconds; the soaking time of the water washing section is 30±5 seconds.

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