Novel leveler, plating solution and use thereof in electroplating processes

Abstract

The application provides a novel leveling agent, a plating solution and application of the leveling agent in an electroplating process. The novel leveling agent is a PEI compound with a general molecular formula R-CH2-CH2-(NH-CH2-CH2) n‑1 -NH-CH(R 1 -SH)-R 2 -SO3H, or a salt or stereoisomer thereof; wherein n is an integer in a range from 25 to 1000; wherein R includes a group containing one or more of C, N, O, S and H atoms; and wherein R 1 , R 2 each independently includes an alkyl group, a heteroalkyl group, an aryl group, a cycloalkyl group or a heterocyclyl group. The novel leveling agent provided by the application can significantly improve uniformity of a plated layer, reduce protrusions or depressions on a surface of the plated layer, is especially suitable for significantly improving flatness of the plated layer under high current density, and has fast electroplating speed, thereby greatly improving reliability and production efficiency of a packaged object.

Description

Technical Field

[0001] This invention relates to the field of electroplating technology, specifically to a novel type of leveling agent, plating solution, and its application in electroplating processes. Background Technology

[0002] As the electronic packaging industry places higher demands on the conductivity and mechanical properties of printed circuit boards, electroplating has become one of the key foundational technologies for advanced packaging. However, the electroplating process currently faces several challenges, including uneven and non-uniform plating surfaces over large areas, and inconsistent solder joint strength, which in turn affects packaging reliability. On one hand, non-uniform plating leads to differences in the bonding strength between the plating layer and the substrate, as well as between different parts of the plating itself. Furthermore, non-uniform plating can generate uneven internal stress during curing and use. Under external forces, the plating layer is prone to peeling, flaking, and cracking, compromising the integrity of the packaging structure. Over time and with the influence of the usage environment, this can ultimately lead to packaging failure, thus affecting the stability of the entire package. On the other hand, non-uniform plating can cause differences in resistance in different areas. This may result in uneven current distribution, causing localized overheating and hindering the packaging structure's conductivity. It may also create excessively thick or thin areas in certain regions, compromising the insulation performance of the package, affecting the normal operation of electronic components within the package, and potentially leading to safety issues such as leakage current, or even component damage.

[0003] Especially at high current densities, the current distribution on the electrode surface is more significantly affected by factors such as electrode shape, electrode spacing, and deposition rate, making it easier to cause uneven coating and thus the aforementioned phenomena. Therefore, solving the problem of uneven coating in high-current-density electroplating processes is crucial for addressing the rapidly evolving electronic packaging technology. Summary of the Invention

[0004] Therefore, it is necessary to provide a leveling agent and plating solution that can achieve rapid electroplating under high current density conditions and produce uniform and reliable plating, as well as its application in the electroplating process.

[0005] In a first aspect, the present invention provides a novel leveling agent having the general molecular formula R-CH2-CH2-(NH-CH2-CH2). n-1 -NH-CH(R 1 -SH)-R 2 PEI compounds with -SO3H, or their salts and stereoisomers;

[0006] In the formula, n is an integer in the range of 25-1000;

[0007] In the formula, R includes one or more groups containing C, N, O, S and H atoms;

[0008] In the formula R 1 R 2 Each can independently include alkyl, heteroalkyl, aryl, cycloalkyl, or heterocyclic groups.

[0009] In some embodiments, the molecular formula of the novel leveling agent further includes at least one of the features shown in (1) to (5) below:

[0010] (1) The R includes amino, hydroxyl, carboxyl, aldehyde, ester, amide, mercapto, cyano, acid anhydride, sulfonyl, sulfonic acid or hydrogen;

[0011] (2) The R 1 Including alkyl or heteroalkyl groups;

[0012] Optionally, the heteroalkyl group contains one or more of N, O, and S atoms;

[0013] Optionally, the alkyl group includes C 2- C 10 alkyl;

[0014] Optionally, the heteroalkyl group includes C 2- C 10 Heteroalkyl;

[0015] (3) The R 1 Including aryl, heterocyclic, or cycloalkyl groups;

[0016] Optionally, the aryl, cycloalkyl, or heterocyclic groups each independently comprise a monocyclic, fused, spirocyclic, or bridged ring.

[0017] Further optionally, the aryl group is a benzene ring or a naphthalene ring;

[0018] (4) The R 2 Including alkyl or heteroalkyl groups;

[0019] Optionally, the heteroalkyl group contains one or more of N, O, and S atoms;

[0020] Optionally, the alkyl group includes C 2- C 10 alkyl;

[0021] Optionally, the heteroalkyl group includes C 2- C 10 Heteroalkyl;

[0022] (5) The R 2 Including aryl, heterocyclic, or cycloalkyl groups;

[0023] Optionally, the aryl, cycloalkyl, or heterocyclic groups each independently comprise a monocyclic, fused, spirocyclic, or bridged ring.

[0024] Alternatively, the aryl group may be a benzene ring or a naphthalene ring.

[0025] In some embodiments, the novel leveling agent has the general molecular formula R-CH2-CH2-(NH-CH2-CH2). n-1 -NH-CH(CH2-SH)-CH2-SO3H, R-CH2-CH2-(NH-CH2-CH2) n-1 -NH-CH2-CH(SH)-CH2-CH2-SO3H, R-CH2-CH2-(NH-CH2-CH2) n-1 -NH-CH(CH3)-CH(SH)-CH2-CH2-SO3H or R-CH2-CH2-(NH-CH2-CH2) n-1 -NH-CH2-CH2-CH(SH)-CH2-CH2-CH2-SO3H;

[0026] In the formula, n is an integer in the range of 25-1000;

[0027] In the formula, R includes one or more groups containing C, N, O, S and H atoms.

[0028] Secondly, the present invention also provides a method for preparing the novel leveling agent, comprising the following steps: reacting a first compound A with a PEI compound to prepare the novel leveling agent;

[0029] The general molecular formula of the first compound A is HO-CH(R) 1 -SH)-R 2 -SO3;

[0030] In the formula R 1 R 2 Each can independently include alkyl, heteroalkyl, aryl, cycloalkyl, or heterocyclic groups;

[0031] The general molecular formula of the PEI compound is R-(CH2CH2NH). n -H;

[0032] In the formula, n is an integer in the range of 25-1000;

[0033] In the formula, R includes one or more groups containing C, N, O, S and H atoms.

[0034] In some embodiments, R in the molecular formula of the first compound A 1 Including C 2- C 10 alkyl;

[0035] Optionally, in the general molecular formula of the first compound A, HO-(R 1In the alkyl group (-SH), -SH and -HO are each independently substituted at different C atoms;

[0036] Optionally, the number of carbon atoms separating the hydroxyl group and the mercapto group is ≥2.

[0037] Thirdly, the present invention also provides a plating solution, the composition of which includes a metal salt and a leveling agent, wherein the leveling agent includes the novel leveling agent provided in the first aspect, or a novel leveling agent prepared by the preparation method of the novel leveling agent provided in the second aspect.

[0038] Optionally, the metal salt comprises a copper salt.

[0039] In some embodiments, the plating solution further satisfies at least one of the following (1) to (3):

[0040] (1) The amount of metal salt added to the plating solution is 180g / L-300g / L;

[0041] (2) The amount of leveling agent added to the plating solution is 0.001 g / L-0.8 g / L;

[0042] (3) The composition of the plating solution includes 180g / L-300g / L copper sulfate, 10g / L-200g / L sulfuric acid, 30mg / L-80mg / L chloride ions, 0.001g / L-0.5g / L sulfur-containing compounds, 0.01g / L-6g / L polyethylene glycol, 0.001g / L-0.5g / L quaternary ammonium salt and 0.001g / L-0.8g / L leveling agent.

[0043] In some embodiments, the plating solution further satisfies at least one of the following (1) to (4):

[0044] (1) The copper sulfate includes anhydrous copper sulfate and / or copper sulfate hydrate;

[0045] Optionally, the copper sulfate hydrate includes one or more of CuSO4·H2O, CuSO4·3H2O, and CuSO4·5H2O;

[0046] (2) The sulfur-containing compounds include one or more of the following: 3-(benzothiazol-2-mercapto)-propane sulfonate, isothiourea propane sulfonate inner salt, propane sulfonate pyridinium salt, N-propane benzene sulfonate, bis(3-sulfopropyl sodium) disulfide, polydisulfide dipropane sulfonate, 3-mercaptopropane sulfonate, N,N-dimethyl-dithioformamide propane sulfonate, 3-thio-isothiourea onium propyl sulfonate, alkyl polyalkoxypropyl sulfonate, linear epoxy naphthol propyl sulfonate, thiourea, 1,3-dimethylthiourea, trimethylthiourea, diethylthiourea and allylthiourea;

[0047] (3) The molecular weight of the polyethylene glycol is 400-40000;

[0048] (4) The composition of the plating solution includes 250g / L-300g / L copper sulfate, 10g / L-50g / L sulfuric acid, 40mg / L-60mg / L chloride ions, 0.08g / L-0.3g / L sulfur-containing compounds, 0.08g / L-1.8g / L polyethylene glycol, 0.03g / L-0.15g / L quaternary ammonium salt and 0.08g / L-0.8g / L leveling agent.

[0049] Fourthly, the present invention also provides an electroplating process, wherein the electroplating is performed using the plating solution provided in the third aspect;

[0050] Provide a substrate with the surface to be electroplated;

[0051] The substrate is brought into contact with the plating solution;

[0052] Electroplating is performed by applying an electric current between the substrate and the anode;

[0053] Optionally, the current density is 0.2 A / dm³. 2 -40A / dm 2 ;

[0054] Optionally, the temperature of the plating solution is 10℃~50℃.

[0055] Fifthly, the present invention also provides a coating, which is obtained by electroplating on the surface of a substrate using the plating solution provided in the third aspect; or by electroplating using the electroplating process provided in the fourth aspect.

[0056] Compared with traditional technologies, the beneficial effects of the technical solution of the present invention include:

[0057] The novel leveling agent of this invention is a PEI-type compound with a specific molecular formula, or its salt or stereoisomer. It can selectively adsorb different sites based on the strength of convection and the magnitude of current density. At sites with strong convection and high current density, nitrogen-containing groups preferentially adsorb onto the coating surface, inhibiting the deposition rate; at sites with weak convection and low current density, sulfur-containing groups preferentially adsorb onto the coating surface, enhancing the deposition rate. This selective adsorption on the coating surface allows for adjustment of the deposition rate in different regions, achieving the required coating smoothness. Furthermore, it exhibits good electroplating performance at high current densities, enabling rapid electroplating and obtaining a uniform and smooth coating. This invention develops a compound with a specific structure, overcoming the shortcomings of traditional technologies, such as the inability to adjust the deposition rate through selective adsorption, poor coating uniformity, and obvious protrusions or depressions on the coating surface. This represents a significant improvement over traditional technologies. Attached Figure Description

[0058] Figure 1 The surface of the copper pillar after electroplating using the plating solutions of Examples 1-6 of this invention.

[0059] Figure 2 The images show the surface condition of the copper pillars after electroplating using the plating solutions of Comparative Examples 1-6 of this invention.

[0060] Figure 3 This is the NMR spectrum of the first compound A, 4-hydroxy-3-mercaptobutyric acid, of the present invention.

[0061] Figure 4 This is the NMR spectrum of the first compound A, 4-hydroxy-3-mercaptopentylsulfonic acid, of the present invention.

[0062] Figure 5 This is the NMR spectrum of the first compound A, 6-hydroxy-4-mercaptohexanesulfonic acid, of the present invention.

[0063] Figure 6 The NMR spectrum of the first compound A, 4-(1-hydroxy-2-mercaptoethyl)benzenesulfonic acid, is shown below.

[0064] Figure 7 The NMR spectrum of the first compound of this invention, A, 6-(1-hydroxy-2-mercaptoethyl)naphthalene-2-sulfonic acid.

[0065] Figure 8 This is the NMR spectrum of the novel leveling agent A1 of this invention.

[0066] Figure 9 This is the NMR spectrum of the novel leveling agent A2 of this invention.

[0067] Figure 10 This is the NMR spectrum of the novel leveling agent A3 of this invention.

[0068] Figure 11 This is the NMR spectrum of the novel leveling agent A4 of this invention.

[0069] Figure 12 This is the NMR spectrum of the novel leveling agent A5 of this invention.

[0070] Figure 13 This is the NMR spectrum of the novel leveling agent A6 of this invention. Detailed Implementation

[0071] To facilitate understanding of the present invention, preferred embodiments are provided below to provide a more comprehensive description of the technical solutions of the present invention. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to enable a thorough and complete understanding of the disclosure of the present invention.

[0072] It should be noted that the experimental methods in the following embodiments of the present invention, unless otherwise specified, are generally performed under conventional conditions or as recommended by the manufacturer. All commonly used chemical reagents used in the embodiments are commercially available products.

[0073] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0074] Unless otherwise stated or in case of contradiction, the terms or phrases used herein shall have the following meanings:

[0075] The term "heterocyclic group" refers to a cycloalkyl group in which at least one carbon atom is replaced by a non-carbon atom, which can be an N atom, O atom, S atom, etc., and can be a saturated ring or a partially unsaturated ring. Phrases containing this term, such as "C4-C9 heterocyclic group," refer to heterocyclic groups containing 4-9 carbon atoms, and each occurrence can independently be a C4 heteroalkyl, C5 heteroalkyl, C6 heteroalkyl, C7 heteroalkyl, C8 heteroalkyl, or C9 heteroalkyl. Suitable examples include, but are not limited to: dihydropyridyl, tetrahydropyridyl (piperidinyl), tetrahydrothiophenyl, sulfur-oxidized tetrahydrothiophenyl, tetrahydrofuranyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, and dihydroindolyl.

[0076] The term "cycloalkyl" refers to a non-aromatic hydrocarbon containing a ring of carbon atoms, which can be monocycloalkyl, spirocycloalkyl, or bridged cycloalkyl. Phrases containing this term, such as "C3-C9 cycloalkyl," refer to cycloalkyl groups containing 3-9 carbon atoms, and each occurrence can independently be C3, C4, C5, or C6 cycloalkyl. Suitable examples include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. Additionally, "cycloalkyl" may contain one or more double bonds; representative examples of cycloalkyl groups containing double bonds include cyclopentenyl, cyclohexenyl, cyclohexadienyl, and cyclobutadienyl.

[0077] The term "aryl" refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing one hydrogen atom. It can be a monocyclic aryl, a fused-ring aryl, or a polycyclic aryl; for polycyclic compounds, at least one must be an aromatic ring system. For example, "C5~C..." 20 "Aryl" refers to an aryl group containing 5 to 20 carbon atoms. Each time it appears, it can independently be C5 aryl, C6 aryl, C7 aryl, C8 aryl, C9 ... 10 Aryl, C 14 Aryl, C 18 Aryl or C20 Aryl group. Suitable examples include, but are not limited to: benzene, biphenyl, naphthalene, anthracene, phenanthrene, dinaphthalene, triphenylene and their derivatives. Understandably, multiple aryl groups may also be interrupted by short non-aromatic units (e.g., <10% non-H atoms, such as C, N or O atoms), specifically acenaphthene, fluorene, or 9,9-diarylfluorene, triarylamines, and diaryl ether systems should also be included in the definition of aryl.

[0078] The term "alkyl" refers to a saturated hydrocarbon containing a primary (normal) carbon atom, or a secondary carbon atom, or a tertiary carbon atom, or a quaternary carbon atom, or a combination thereof. Phrases containing this term, such as "C1-C9 alkyl," refer to alkyl groups containing 1 to 9 carbon atoms, and each occurrence can independently be C1 alkyl, C2 alkyl, C3 alkyl, C4 alkyl, C5 alkyl, C6 alkyl, C7 alkyl, C8 alkyl, or C9 alkyl. Suitable examples include, but are not limited to: methyl (Me, -CH3), ethyl (Et, -CH2CH3), 1-propyl (n-Pr, n-propyl, -CH2CH2CH3), 2-propyl (i-Pr, i-propyl, -CH(CH3)2), 1-butyl (n-Bu, n-butyl, -CH2CH2CH2CH3), etc.

[0079] The term "heteroalkyl" refers to an alkyl group in which at least one carbon atom is replaced by a non-carbon atom, which can be an N atom, O atom, S atom, etc. For example, if the carbon atom in the alkyl group that is attached to the parent nucleus is replaced by a non-carbon atom, the resulting heteroalkyl group is an alkoxy group (e.g., -OCH3, etc.), an amine (e.g., -NHCH3, -N(CH3)2, etc.), or a thioalkyl group (e.g., -SCH3). If the carbon atom in the alkyl group that is not attached to the parent nucleus is replaced by a non-carbon atom, the resulting heteroalkyl group is an alkyl ether (e.g., -CH2CH2-O-CH3, etc.), an alkylamine (e.g., -CH2NHCH3, -CH2N(CH3)2, etc.), or a thioalkyl ether (e.g., -CH2-S-CH3). If the terminal carbon atom of the alkyl group is replaced by a non-carbon atom, the resulting heteroalkyl group is a hydroxyalkyl group (e.g., -CH2CH2-OH), an aminoalkyl group (e.g., -CH2NH2), or an alkyl mercapto group (e.g., -CH2CH2-SH). Phrases containing the term, such as heteroalkyl containing 1 to 9 carbon atoms, can be independently C2 heteroalkyl, C3 heteroalkyl, C4 heteroalkyl, C5 heteroalkyl, C7 heteroalkyl, C8 heteroalkyl, or C9 heteroalkyl each time they appear.

[0080] Electroplating is closely related to electrochemistry, organic chemistry, interface chemistry, crystallography, and kinetics, and is a comprehensive applied technology.

[0081] Electroplating is actually a metal electrodeposition process, which uses the principle of electrolysis to obtain a metal deposition layer on a solid surface. It is a process that uses electrolysis to attach a metal film to the surface of a substrate, providing a protective layer for the surface of parts or materials or changing the surface properties of the base material, thereby preventing metal oxidation, improving wear resistance, conductivity, reflectivity, corrosion resistance, and enhancing aesthetics.

[0082] Electroplating solution refers to a liquid that can expand the range of cathode current density of metals, improve the appearance of the coating, and increase the stability of the solution against oxidation.

[0083] Electroplating additives refer to a collective term for various chemical substances added to the plating solution during the electroplating process to improve the quality of the plating layer. Based on their function in the electroplating solution, they can be classified into complexing agents, brighteners and auxiliary brighteners, leveling agents, pinhole removers, dispersants, wetting agents, and smoke suppressants, etc.

[0084] Electroplating additives are an important component of electroplating solutions, playing an irreplaceable role in the electroplating process. Additives can effectively improve the current distribution during electroplating, enhance the uniformity of the plating solution, and influence the transport and electrocrystallization process of metal ions from the bulk solution to the reaction interface, thereby altering the electrochemical deposition rate at microscopic depressions and protrusions on the plate surface.

[0085] A leveling agent is a substance added to an electroplating solution to improve the smoothness of the coating, making the resulting coating smoother than the substrate surface.

[0086] The "PEI" mentioned in this invention includes polyalkylimide compounds, but is not limited to substances named polyetherimide, polyethyleneimide, polyetherimide, polyethyleneimide, etc.

[0087] The “PEI-type compounds” involved in this invention include a class of derivative compounds having a polyalkylimide backbone, but are not limited to backbones named with polyetherimide, polyethyleneimine, polyetherimide, polyethyleneimine, etc.

[0088] Traditional electroplating processes result in uneven surface morphology, leading to decreased coating smoothness. Furthermore, traditional electroplating solutions require specific, low current densities for operation; exceeding these densities can cause failure, impacting the electroplating process and coating performance, ultimately affecting the performance of the packaged object. Additionally, traditional electroplating is slow, reducing production efficiency. Therefore, this invention addresses the shortcomings of traditional electroplating processes by developing a plating solution additive.

[0089] In a first aspect, the present invention provides a novel leveling agent having the general molecular formula R-CH2-CH2-(NH-CH2-CH2). n-1 -NH-CH(R 1 -SH)-R2 PEI compounds with -SO3H, or their salts and stereoisomers;

[0090] In the formula, n is an integer in the range of 25-1000;

[0091] In the formula, R includes one or more groups containing C, N, O, S and H atoms;

[0092] In the formula R 1 R 2 Each can independently include alkyl, heteroalkyl, aryl, cycloalkyl, or heterocyclic groups.

[0093] The novel leveling agent of this invention has the following composition: R-CH2-CH2-(NH-CH2-CH2). n-1 -NH-CH(R 1 -SH)-R 2 The general molecular formula of -SO3H allows for the selection of different adsorption sites based on the strength of convection and the magnitude of current density. At sites with strong convection and high current density, nitrogen-containing groups preferentially adsorb onto the coating surface, suppressing the deposition rate; conversely, at sites with weak convection and low current density, sulfur-containing groups preferentially adsorb onto the coating surface, enhancing the deposition rate. By selectively adsorbing this type of material onto the coating surface, the deposition rate in different regions can be adjusted to achieve the required coating smoothness. Simultaneously, it significantly increases the current density during the electroplating process, achieving a uniform and reliable coating even at high current densities. This also greatly improves the electroplating speed and reduces the cost of the electroplating process.

[0094] In some embodiments, the chemical structural formula of the novel leveling agent is:

[0095]

[0096] In some embodiments, the R in the molecular formula of the novel leveling agent includes amino, hydroxyl, carboxyl, aldehyde, ester, amide, mercapto, cyano, acid anhydride, sulfonyl, sulfonic acid, or hydrogen.

[0097] In some embodiments, R in the molecular formula of the novel leveling agent 1 Including alkyl or heteroalkyl groups.

[0098] In some embodiments, the heteroalkyl group contains one or more of N, O, and S atoms.

[0099] In some embodiments, the alkyl group includes C 2- C 10 alkyl.

[0100] In some embodiments, the heteroalkyl group includes C 2- C 10 Heteroalkyl groups.

[0101] In some embodiments, R in the molecular formula of the novel leveling agent 1 Including R 1 Including aryl, heterocyclic, or cycloalkyl groups;

[0102] Optionally, the aryl, cycloalkyl, or heterocyclic groups each independently comprise a monocyclic, fused, spirocyclic, or bridged ring.

[0103] Alternatively, the aryl group may be a benzene ring or a naphthalene ring.

[0104] In some embodiments, R in the molecular formula of the novel leveling agent 2 Including alkyl or heteroalkyl groups.

[0105] In some embodiments, the heteroalkyl group contains one or more of N, O, and S atoms.

[0106] In some embodiments, the alkyl group includes C 2- C 10 alkyl.

[0107] In some embodiments, the heteroalkyl group includes C 2- C 10 Heteroalkyl groups.

[0108] In some embodiments, R in the molecular formula of the novel leveling agent 2 Including aryl, heterocyclic, or cycloalkyl groups.

[0109] In some embodiments, the aryl, cycloalkyl, or heterocyclic groups each independently comprise a monocyclic, fused, spirocyclic, or bridged ring.

[0110] In some embodiments, the aryl group is a benzene ring or a naphthalene ring.

[0111] In some embodiments, the novel leveling agent has the general molecular formula R-CH2-CH2-(NH-CH2-CH2). n-1 -NH-CH(CH2-SH)-CH2-SO3H, R-CH2-CH2-(NH-CH2-CH2) n-1 -NH-CH2-CH(SH)-CH2-CH2-SO3H, R-CH2-CH2-(NH-CH2-CH2) n-1 -NH-CH(CH3)-CH(SH)-CH2-CH2-SO3H or R-CH2-CH2-(NH-CH2-CH2) n-1 -NH-CH2-CH2-CH(SH)-CH2-CH2-CH2-SO3H;

[0112] In the formula, n is an integer in the range of 25-1000;

[0113] In the formula, R includes one or more groups containing C, N, O, S and H atoms.

[0114] The novel leveling agent provided by this invention can significantly improve the surface properties of the coating, increase the electroplating rate, and enhance the reliability of the packaged object.

[0115] In a second aspect, the present invention also provides a method for preparing the novel leveling agent provided in the first aspect, comprising the following steps: reacting a first compound A with a PEI compound to prepare the novel leveling agent;

[0116] The general molecular formula of the first compound A is HO-CH(R) 1 -SH)-R 2 -SO3;

[0117] In the formula R 1 R 2 Each can independently include alkyl, heteroalkyl, aryl, cycloalkyl, or heterocyclic groups;

[0118] The general molecular formula of the PEI compound is R-(CH2CH2NH). n -H;

[0119] In the formula, n is an integer in the range of 25-1000;

[0120] In the formula, R includes one or more groups containing C, N, O, S and H atoms.

[0121] The general molecular formula of the PEI compound is R-(CH2CH2NH). n -H; as a non-limiting example, the general molecular formula of the PEI compound includes R-CH2-CH2-(NH-CH2-CH2). n-1 -NH2.

[0122] In some embodiments, R in the molecular formula of the first compound A 1 Including C 2- C 10 alkyl.

[0123] In some embodiments, the molecular formula of the first compound A is HO-(R 1 The thiol group (-SH) and hydroxyl group (-OH) in the alkyl group are each independently substituted at different C atoms in the alkyl group.

[0124] In some embodiments, the number of carbon atoms separating the hydroxyl group and the thiol group is ≥2.

[0125] As a non-limiting example, the first compound A includes 2-hydroxy-3-mercaptopropanesulfonic acid, 4-hydroxy-3-mercaptobutanesulfonic acid, 4-hydroxy-3-mercaptopentylsulfonic acid, 6-hydroxy-4-mercaptohexanesulfonic acid, 4-(1-hydroxy-2-mercaptoethyl)benzenesulfonic acid, or 6-(1-hydroxy-2-mercaptoethyl)naphthalene-2-sulfonic acid.

[0126] In some embodiments, the method for preparing the novel leveling agent includes: reacting the first compound A with a PEI compound, a coupling agent, and an accelerator to prepare the novel leveling agent.

[0127] In some embodiments, the molar ratio of the first compound A to the PEI compound is 1:(0.5-2). As a non-limiting example, it includes, but is not limited to, 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.5, 1:1.8, 1:2 or any range formed by both of the foregoing and any value within that range.

[0128] In some embodiments, the molar ratio of the first compound A to the PEI compound, the coupling agent, and the promoter is 1:(0.5-2):(0.8-1.5):(0.8-1.5). As a non-limiting example, this includes, but is not limited to, 1:0.5:0.8:0.8, 1:0.5:1:1, 1:0.5:1:1.5, 1:0.5:1.5:1.5, 1:2:0.8:0.8, 1:2:1.5:1, 1:2:1.5:1.5, or any range formed by both of the foregoing and any value within that range.

[0129] In some embodiments, the first compound A is reacted with a PEI compound, a coupling agent, and an accelerator to prepare a novel leveling agent.

[0130] In some embodiments, the first compound A and the PEI compound are dissolved in a solvent, and a coupling agent and an accelerator are added to react and prepare a novel leveling agent.

[0131] In some embodiments, the solvent includes one or more of tetrahydrofuran, N,N-dimethylformamide, benzene, dioxane, and dichloromethane.

[0132] In some embodiments, the coupling agent includes one or more of azobisisopropyl dicarboxylic acid (DIAD), diethyl azodicarboxylate (DEAD), di(p-chlorobenzyl) azodicarboxylate (DCAD), and di-4-nitrobenzyl azodicarboxylate (DNAD).

[0133] In some embodiments, the promoter includes one or more of organophosphorus compounds, azaphosphorus compounds, other phosphorus derivatives, and other heterocyclic compounds.

[0134] In some embodiments, the promoter includes one or more of triphenylphosphine (PPh3), tributylphosphine (P(n-Bu)3), 4-aminopyridine (4-Aminopyridine), and triphenylphosphine iodide.

[0135] Thirdly, the present invention also provides a plating solution comprising a metal salt and a leveling agent; the leveling agent comprises the novel leveling agent provided in the first aspect, or a novel leveling agent prepared by the preparation method provided in the second aspect.

[0136] The novel leveling agent has the following properties: R-CH2-CH2-(NH-CH2-CH2). n-1 -NH-CH(R 1 -SH)-R 2 The general molecular formula of -SO3H;

[0137] In the formula, n is an integer in the range of 10-200;

[0138] In the formula, R includes one or more groups containing C, N, O, S and H atoms;

[0139] In the formula R 1 R 2 Each can independently include alkyl, heteroalkyl, aryl, cycloalkyl, or heterocyclic groups.

[0140] In some embodiments, the metal salt includes a copper salt.

[0141] In some embodiments, the amount of metal salt added to the plating solution is 180 g / L to 300 g / L. As a non-limiting example, it includes, but is not limited to, 180 g / L, 200 g / L, 220 g / L, 250 g / L, 280 g / L, 300 g / L, or any range formed by any two of the foregoing and any value within the range.

[0142] In some embodiments, the amount of leveling agent added to the plating solution is 0.001 g / L to 0.8 g / L. As a non-limiting example, it includes, but is not limited to, 0.001 g / L, 0.005 g / L, 0.01 g / L, 0.05 g / L, 0.1 g / L, 0.2 g / L, 0.3 g / L, 0.4 g / L, 0.5 g / L, 0.6 g / L, 0.7 g / L, 0.8 g / L, or any range formed by either of the foregoing and any value within that range.

[0143] In some embodiments, the plating solution comprises 180g / L-300g / L copper sulfate, 10g / L-200g / L sulfuric acid, 30mg / L-80mg / L chloride ions, 0.001g / L-0.5g / L sulfur-containing compounds, 0.01g / L-6g / L polyethylene glycol, 0.001g / L-0.5g / L quaternary ammonium salt, and 0.001g / L-0.8g / L leveling agent.

[0144] In some embodiments, the copper sulfate includes anhydrous copper sulfate and / or copper sulfate hydrate. Furthermore, the present invention uses a plating solution containing copper sulfate hydrate to better achieve the technical effects of the present invention.

[0145] In some embodiments, the copper sulfate hydrate includes one or more of CuSO4·H2O, CuSO4·3H2O, and CuSO4·5H2O; furthermore, the use of a plating solution containing CuSO4·5H2O can better achieve the technical effects of the present invention.

[0146] In some embodiments, the sulfur-containing compound includes one or more of 3-(benzothiazole-2-mercapto)-propane sulfonate, isothiourea propane sulfonate inner salt, propane sulfonate pyridinium salt, N-propane benzene sulfonate, bis(3-sulfopropyl sodium) disulfide, polydisulfide dipropane sulfonate, 3-mercaptopropane sulfonate, N,N-dimethyl-dithioformamide propane sulfonate, 3-thio-isothiourea onium propyl sulfonate, alkyl polyalkoxypropyl sulfonate, linear epoxy naphthol propyl sulfonate, thiourea, 1,3-dimethylthiourea, trimethylthiourea, diethylthiourea, and allylthiourea; furthermore, the use of 3-(benzothiazole-2-mercapto)-propane sulfonate and / or isothiourea propane sulfonate inner salt can better achieve the technical effects of the present invention.

[0147] In some embodiments, the molecular weight of the polyethylene glycol is 400-40000, including but not limited to 400, 800, 1000, 2000, 4000, 6000, 8000, 10000, 20000, 30000, 40000 or any of the foregoing ranges and any value within that range; furthermore, the present invention selects polyethylene glycol with a molecular weight of 6000-10000 to better achieve the technical effects of the present invention.

[0148] In some embodiments, the quaternary ammonium salt includes monoquaternary ammonium salts and / or polyquaternary ammonium salts.

[0149] In some embodiments, the quaternary ammonium salt may also be a modified quaternary ammonium salt.

[0150] As a non-limiting example, the modified quaternary ammonium salt includes, but is not limited to, polyethyleneimine quaternary ammonium salt, HACC, TPyP-Et, BZC and / or PQ, wherein the polyethyleneimine quaternary ammonium salt is selected from one or more of polyethyleneimine chloride, polyethyleneimine bromide, polyethyleneimine methyl sulfate and polyethyleneimine methoxylate.

[0151] In some embodiments, the plating solution comprises 250g / L-300g / L copper sulfate, 10g / L-50g / L sulfuric acid, 40mg / L-60mg / L chloride ions, 0.08g / L-0.3g / L sulfur-containing compounds, 0.08g / L-1.8g / L polyethylene glycol, 0.03g / L-0.15g / L quaternary ammonium salt, and 0.08g / L-0.8g / L leveling agent.

[0152] The plating solution prepared by this invention has selective adsorption on the surface of the coating to adjust the deposition rate in different areas, thereby achieving the coating smoothness requirement and improving the reliability of the packaged object.

[0153] Fourthly, the present invention also provides an electroplating process, wherein the electroplating is performed using the plating solution provided in the third aspect;

[0154] Provide a substrate with the surface to be electroplated;

[0155] The substrate is brought into contact with the plating solution;

[0156] Electroplating is performed by applying an electric current between the substrate and the anode.

[0157] In some embodiments, the current density is 0.2 A / dm³. 2 -40A / dm 2 .

[0158] In some embodiments, the temperature of the plating solution is 10°C to 50°C.

[0159] Fifthly, the present invention also provides a coating, which is obtained by electroplating on the surface of a substrate using the aforementioned plating solution; or by electroplating using the electroplating process provided in the fourth aspect.

[0160] For experimental parameters not specified in the following specific embodiments, please refer to the guidelines given in this application document first, or refer to experimental manuals or other experimental methods known in the art, or refer to the experimental conditions recommended by the manufacturer.

[0161] The raw materials and reagents involved in the following specific embodiments can be obtained commercially or prepared by those skilled in the art using known methods.

[0162] The types and sources of some of the reagents and raw materials involved in the embodiments of the present invention are as follows:

[0163] PEI: Polyethyleneimine, CAS: 9002-98-6.

[0164] The first compound A includes 2-hydroxy-3-mercaptopropanesulfonic acid, 4-hydroxy-3-mercaptobutanesulfonic acid, 4-hydroxy-3-mercaptopentylsulfonic acid, 6-hydroxy-4-mercaptohexanesulfonic acid, 4-(1-hydroxy-2-mercaptoethyl)benzenesulfonic acid, or 6-(1-hydroxy-2-mercaptoethyl)naphthalene-2-sulfonic acid.

[0165] Preparation of the first compound A:

[0166] Preparation of 4-hydroxy-3-mercaptobutyric acid: Using 0.1 mol of 3,4-epoxy-1-butene as a starting material, 10 mL of pyridine and 50 mL-100 mL of dichloromethane were added. 0.11 mol of chlorosulfonic acid was slowly added dropwise at -5°C to 5°C, and the reaction was allowed to proceed for 2-3 hours to obtain 3,4-epoxy-1-butyric acid. Alternatively, using 0.1 mol of 3,4-epoxy-1-butyric acid as a starting material, with 0.1 mmol-0.2 mmol of p-toluenesulfonic acid or triethylamine as a catalyst, and 50 mL-100 mL of DMF as a solvent, 0.3 mol-0.5 mol of hydrogen sulfide gas was introduced at 30°C-50°C, and the reaction was allowed to proceed for 3-8 hours. After the reaction was complete, 4-hydroxy-3-mercaptobutyric acid was obtained, and its NMR data are as follows: 1 ¹H NMR (OH: 4.24, SH: 1.3, SO₃H: 8.5, CH: 2.46), see appendix. Figure 3 .

[0167] Preparation of 4-hydroxy-3-mercaptopentanesulfonic acid: Using 0.1 mol of 1,3-pentadiene as a starting material, and 120-150 mL of dichloromethane as a solvent, 0.12 mol-0.15 mol of m-chloroperoxybenzoic acid was added at 0-5°C, and the reaction was allowed to proceed for 3-6 hours. After the reaction was complete, 3,4-epoxy-1-pentene was obtained. Using 0.1 mol of 3,4-epoxy-1-pentene as a starting material, and 0.12-0.15 mol of chlorosulfonic acid as a sulfonating agent, and 50-100 mL of dichloromethane as a solvent, chlorosulfonic acid was added dropwise at 0-10°C. After the addition was complete, the temperature was raised to room temperature and the reaction was continued for 2-4 hours. After the reaction was complete, 3,4-epoxy-1-pentanesulfonic acid was obtained by ice-water hydrolysis and extraction. Using 0.1 mol of 3,4-epoxy-1-pentanesulfonic acid as a starting material and 100-150 mL of water as a solvent, 0.12-0.15 mol of sodium hydrosulfide was added at 40-60℃, and the reaction was allowed to proceed for 3-6 hours. After the reaction was completed, the mixture was cooled and acidified with 2-3 mol / L-3 mol / L dilute hydrochloric acid to a pH of 2-3 to obtain 4-hydroxy-3-mercaptopentanesulfonic acid. Its NMR data are as follows:1 ¹H NMR (OH: 4.77, SH: 1.3, SO₃H: 8.5, CH₃: 1.11), see appendix. Figure 4 .

[0168] Preparation of 6-hydroxy-4-mercaptohexanesulfonic acid: Using 0.1 mol of 1,3,5-hextriene as the starting material, and 100-150 mL of dichloromethane as the solvent, 0.12-0.15 mol of concentrated sulfuric acid was added dropwise at 0-5℃. After the addition was complete, the temperature was raised to room temperature (20-25℃), and the reaction was allowed to proceed for 3-6 hours. After the reaction was completed, the mixture was poured into crushed ice to terminate the reaction, yielding 3,5-diene-hexanesulfonic acid. Alternatively, using 0.1 mol of 3,5-diene-hexanesulfonic acid as the starting material, and 5%-10% benzoyl peroxide (0.005-0.01 mol) as the initiator, and 150-200 mL of dichloromethane as the solvent, 0.12-0.15 mol of hydrogen sulfide gas was introduced at 50-60℃, and the reaction was allowed to proceed for 8-12 hours, yielding 4-mercapto-5-diene-hexanesulfonic acid. Using 0.1 mol of 4-mercapto-5-en-hexanesulfonic acid as a starting material, 0.12 mol-0.15 mol of sodium borohydride as a reducing agent, 0.2 mol-0.3 mol of sodium hydroxide to adjust the alkalinity, and 100 mL-150 mL of water as a solvent, the reaction was carried out at 0℃-5℃ for 2-3 hours. After the reaction, the pH was adjusted to 6-7 with dilute hydrochloric acid to obtain 6-hydroxy-4-mercaptohexanesulfonic acid. Its NMR data are as follows: 1 ¹H NMR (OH: 6.28, SH: 1.3, SO₃H: 8.5, CH: 2.36), see appendix. Figure 5 .

[0169] Preparation of 4-(1-hydroxy-2-mercaptoethyl)benzenesulfonic acid: Using 0.1 mol of p-styrenesulfonic acid as a starting material, 0.12 mol-0.15 mol of m-chloroperoxybenzoic acid as an oxidant, and 150 mL-200 mL of dichloromethane as a solvent, the reaction was carried out at 0℃-5℃ for 2-4 hours. After the reaction, saturated sodium sulfite solution was added to remove the remaining oxidant, yielding p-epoxyethylbenzenesulfonic acid. Alternatively, using 0.1 mol of p-epoxyethylbenzenesulfonic acid as a starting material, 0.12 mol-0.15 mol of sodium hydrosulfide as a reactant, and 100 mL-150 mL of ethanol and 50 mL-100 mL of water as a mixed solvent, the reaction was carried out at 40-50℃ for 4-6 hours. After the reaction, the pH was adjusted to 6-7 with dilute hydrochloric acid to obtain 4-(1-hydroxy-2-mercaptoethyl)benzenesulfonic acid. Its NMR data are as follows: 1 ¹H NMR (OH: 5.17, SH: 1.4, SO₃H: 8.5, CH (linked OH): 5.19, CH (benzene ring): 7.63, 7.83), see appendix. Figure 6 .

[0170] Preparation of 6-(1-hydroxy-2-mercaptoethyl)naphthalene-2-sulfonic acid: Using 0.1 mol of 6-vinylnaphthalene as a starting material, and 0.12 mol-0.15 mol of concentrated sulfuric acid as a sulfonating agent, the reaction was carried out at 50℃-80℃ for 2-4 hours. After the reaction, the reaction solution was cooled and diluted in ice water, and the pH was adjusted to neutral with sodium carbonate solution to obtain 6-vinylnaphthalene-2-sulfonic acid. Alternatively, using 0.1 mol of 6-vinylnaphthalene-2-sulfonic acid as a starting material, and 0.12 mol-0.15 mol of m-chloroperoxybenzoic acid as an epoxidizing agent, and 150 mL-200 mL of dichloromethane as a solvent, the reaction was carried out at 0℃-5℃ for 2-4 hours. After the reaction, saturated sodium sulfite solution was added to remove the remaining oxidizing agent to obtain 6-(epoxyethyl)naphthalene-2-sulfonic acid. Using 0.1 mol of 6-(epoxyethyl)naphthalene-2-sulfonic acid as a starting material, and 0.12 mol-0.15 mol of sodium hydrosulfide as a reactant, and 100 mL-150 mL of water and 100 mL-150 mL of ethanol as a mixed solvent, the reaction was carried out at 30℃-50℃ for 3-8 hours. After the reaction, the pH was adjusted to 6-7 with dilute hydrochloric acid to obtain 6-(1-hydroxy-2-mercaptoethyl)naphthalene-2-sulfonic acid. Its NMR data are as follows: 1 ¹H NMR (OH: 5.17, SH: 1.4, SO₃H: 8.5, CH (linked OH): 5.19, CH (benzene ring): 7.48, 7.71, 7.90, 8.09, 8.37, 8.73), see appendix. Figure 7 .

[0171] Preparation of novel leveling agent:

[0172] Novel leveling agent A1: 1 mmol of 2-hydroxy-3-mercaptopropanesulfonic acid and 1.2 mmol of PEI were dissolved in THF solution, and 1.2 mmol of DIAD and 1.2 mmol of PPh3 were added. The mixture was reacted at room temperature for 2 h to obtain leveling agent A1.

[0173] The molecular structural formula of the leveling agent A1 is:

[0174]

[0175] Its NMR data are as follows: 1 ¹H NMR (SH: 1.3%, SO₃H: 8.4%, NH(-NHCH₂CH₂-): 1.5%, CH₂(-NHCH₂CH₂-): 2.5~2.7%), see appendix for details. Figure 8 .

[0176] Novel leveling agent A2: 1 mmol of 4-hydroxy-3-mercaptobutyric acid and 1.2 mmol of PEI were dissolved in THF solution, and 1.2 mmol of DIAD and 1.2 mmol of PPh3 were added. The mixture was reacted at room temperature for 2 h to obtain leveling agent A2.

[0177] The molecular structural formula of the leveling agent A2 is:

[0178]

[0179] Its NMR data are as follows: 1 ¹H NMR (SH: 1.3%, SO₃H: 8.5%, NH(-NHCH₂CH₂-): 1.5%, CH₂(-NHCH₂CH₂-): 2.5~2.7%), see appendix for details. Figure 9 .

[0180] Novel leveling agent A3: 1 mmol of 4-hydroxy-3-mercaptopentylsulfonic acid and 1.2 mmol of PEI were dissolved in THF solution, and 1.2 mmol of DIAD and 1.2 mmol of PPh3 were added. The mixture was reacted at room temperature for 2 h to obtain leveling agent A3.

[0181] The molecular structural formula of the leveling agent A3 is:

[0182]

[0183] Its NMR data are as follows: 1 H NMR (SH: 1.3%, SO3H: 8.5%, NH (-NHCH2CH2-): 1.5%, CH2 (-NHCH2CH2-): 2.5~2.7%, CH3: 1.06%), see appendix for details. Figure 10 .

[0184] Novel leveling agent A4: 1 mmol of 6-hydroxy-4-mercaptohexanesulfonic acid and 1.2 mmol of PEI were dissolved in THF solution, and 1.2 mmol of DIAD and 1.2 mmol of PPh3 were added. The mixture was reacted at room temperature for 3 h to obtain leveling agent A4.

[0185] The molecular structural formula of the leveling agent A4 is:

[0186]

[0187] Its NMR data are as follows: 1 ¹H NMR (SH: 1.5%, SO₃H: 8.5%, NH(-NHCH₂CH₂-): 1.5%, CH₂(-NHCH₂CH₂-): 2.5~2.6%, CH₃: 1.06%, CH: 2.36%), see appendix for details. Figure 11 .

[0188] Novel leveling agent A5: 1 mmol of 4-(1-hydroxy-2-mercaptoethyl)benzenesulfonic acid and 1.2 mmol of PEI were dissolved in THF solution, and 1.3 mmol of DIAD and 1.3 mmol of PPh3 were added. The mixture was reacted at room temperature for 3 h to obtain leveling agent A5.

[0189] The molecular structural formula of the leveling agent A5 is:

[0190]

[0191] Its NMR data are as follows: 1 ¹H NMR (SH: 1.4, SO₃H: 8.5, NH (-NHCH₂CH₂-): 1.5, CH₂ (-NHCH₂CH₂-): 2.5~2.6, CH (benzene ring): 7.63, 7.83, CH: 4.22). See appendix for details. Figure 12 .

[0192] Novel leveling agent A6: 1 mmol of 6-(1-hydroxy-2-mercaptoethyl)naphthalene-2-sulfonic acid and 1.2 mmol of PEI were dissolved in THF solution, and 1.4 mmol of DIAD and 1.4 mmol of PPh3 were added. The mixture was reacted at room temperature for 4 h to obtain leveling agent A6.

[0193] The molecular structural formula of the leveling agent A6 is:

[0194]

[0195] Its NMR data are as follows: 1 ¹H NMR (SH: 1.4, SO₃H: 8.5, NH (-NHCH₂CH₂-): 1.5, CH₂ (-NHCH₂CH₂-): 2.5~2.6, CH (naphthalene ring): 7.48, 7.62, 7.84, 8.05, 8.34, 8.72, CH: 4.22), see appendix for details. Figure 13 .

[0196] Example 1: Preparation of plating solution and electroplating process

[0197] The formulation and preparation method of the plating solution in this embodiment are as follows:

[0198] The formulation of the plating solution is as follows:

[0199] Copper sulfate pentahydrate 300g / L

[0200] Sulfuric acid 10g / L

[0201] Chloride ions (derived from hydrochloric acid) 40 mg / L

[0202] New leveling agent A1 0.1g / L

[0203] 3-(benzothiazole-2-mercapto)-propane sulfonate 0.15 g / L

[0204] Polyethylene glycol 8000 0.8 g / L, and

[0205] Quaternary ammonium salt 0.03 g / L.

[0206] Quaternary ammonium salts (model: HACC, see Tetrahedron, 2025, 172: 134436.)

[0207] The plating solution is prepared by:

[0208] Prepare raw materials according to the formula, ensuring the purity meets requirements. Add approximately half volume of deionized water to a clean plating tank, slowly add the prescribed amount of copper sulfate pentahydrate, stirring until completely dissolved. Then add an appropriate amount of sulfuric acid while stirring, add chloride ions, followed by leveling agent A1, 3-(benzothiazole-2-mercapto)-propane sulfonate, polyethylene glycol 8000, and quaternary ammonium salt. Stir thoroughly until homogeneous. Add deionized water to bring the plating solution to 10L, stirring until homogeneous to prepare the plating solution. Filter the plating solution to remove any possible impurities. Perform component analysis and adjustment of the plating solution to ensure the content of each component is within the specified range, making adjustments as necessary.

[0209] The electroplating process parameters for the plating solution are: temperature 20±2℃, current density 8A / dm³. 2 Electroplating time: 45 minutes.

[0210] Example 2: Preparation of plating solution and electroplating process

[0211] The formulation and preparation method of the plating solution in this embodiment are as follows:

[0212] The formulation of the plating solution is as follows:

[0213] Copper sulfate pentahydrate 250g / L

[0214] Sulfuric acid 50g / L

[0215] Chloride ions (derived from hydrochloric acid) 60 mg / L

[0216] New leveling agent A2 0.08g / L,

[0217] 3-(benzothiazole-2-mercapto)-propane sulfonate 0.3 g / L

[0218] Polyethylene glycol 6000 1.2 g / L, and

[0219] Quaternary ammonium salt 0.15 g / L.

[0220] Quaternary ammonium salt (model: TPyP-Et, see Tetrahedron, 2024, 159: 134011.)

[0221] The above-mentioned plating solution formulation was prepared using the preparation method of Example 1.

[0222] The electroplating process parameters for the plating solution are: temperature 40±2℃, current density 15A / dm³. 2 Electroplating time: 25 minutes.

[0223] Example 3: Preparation of plating solution and electroplating process

[0224] The formulation and preparation method of the plating solution in this embodiment are as follows:

[0225] The formulation of the plating solution is as follows:

[0226] Copper sulfate pentahydrate 250g / L

[0227] Sulfuric acid 50g / L

[0228] Chloride ions (derived from hydrochloric acid) 50 mg / L

[0229] New leveling agent A3 0.5g / L

[0230] Isothiourea propanesulfonic acid inner salt 0.08 g / L

[0231] Polyethylene glycol 10000 1.8 g / L, and

[0232] Quaternary ammonium salt 0.1 g / L.

[0233] Quaternary ammonium salt (model: BZC, see Benzyl-containing quaternary ammonium salt as anew leveler for microvia copper electroplating[J]. Electrochimica Acta, 2022,429: 141013.)

[0234] The above-mentioned plating solution formulation was prepared using the preparation method of Example 1.

[0235] The electroplating process parameters for the plating solution are: temperature 30±2℃, current density 25A / dm³. 2 Electroplating time: 45 minutes.

[0236] Example 4: Preparation of plating solution and electroplating process

[0237] The formulation and preparation method of the plating solution in this embodiment are as follows:

[0238] The formulation of the plating solution is as follows:

[0239] Copper sulfate pentahydrate 250g / L

[0240] Sulfuric acid 50g / L

[0241] Chloride ions (derived from hydrochloric acid) 50 mg / L

[0242] New leveling agent A4 0.8g / L

[0243] Isothiourea propanesulfonic acid inner salt 0.2 g / L

[0244] Polyethylene glycol 10000 1.8 g / L, and

[0245] Quaternary ammonium salt 0.1 g / L.

[0246] Quaternary ammonium salt (model: PQ, see Cu Pillar Electroplating Using a Synthetic Polyquaterntum Leveler and Its Coupling Effect on SAC305 / Cu Solder JointVoiding[J].Materials.Materials, 2024, 17(22): 5405.DOI:10.3390 / ma17225405)

[0247] The above-mentioned plating solution formulation was prepared using the preparation method of Example 1.

[0248] The electroplating process parameters for the plating solution are: temperature 30±2℃, current density 25A / dm³. 2 Electroplating time: 45 minutes.

[0249] Example 5: Preparation of plating solution and electroplating process

[0250] The formulation and preparation method of the plating solution in this embodiment are as follows:

[0251] The formulation of the plating solution is as follows:

[0252] Copper sulfate pentahydrate 250g / L

[0253] Sulfuric acid 50g / L

[0254] Chloride ions (derived from hydrochloric acid) 50 mg / L

[0255] New leveling agent A5 0.8g / L

[0256] Isothiourea propanesulfonic acid inner salt 0.2 g / L

[0257] Polyethylene glycol 10000 1.8 g / L, and

[0258] Quaternary ammonium salt 0.1 g / L.

[0259] Quaternary ammonium salt (model: BZC, see Benzyl-containing quaternary ammonium salt as anew leveler for microvia copper electroplating, Electrochimica Acta, 2022, 429: 141013.)

[0260] The above-mentioned plating solution formulation was prepared using the preparation method of Example 1.

[0261] The electroplating process parameters for the plating solution are: temperature 35±2℃, current density 40A / dm³. 2 Electroplating time: 45 minutes.

[0262] Example 6: Preparation of plating solution and electroplating process

[0263] The formulation and preparation method of the plating solution in this embodiment are as follows:

[0264] The formulation of the plating solution is as follows:

[0265] Copper sulfate pentahydrate 250g / L

[0266] Sulfuric acid 50g / L

[0267] Chloride ions (derived from hydrochloric acid) 50 mg / L

[0268] New leveling agent A6 0.5g / L

[0269] Isothiourea propanesulfonic acid inner salt 0.08 g / L

[0270] Polyethylene glycol 10000 1.8 g / L, and

[0271] Quaternary ammonium salt 0.1 g / L.

[0272] Quaternary ammonium salt (polyethyleneimine quaternary ammonium salt: Lutron PVI, BASF)

[0273] The above-mentioned plating solution formulation was prepared using the preparation method of Example 1.

[0274] The electroplating process parameters for the plating solution are: temperature 30±2℃, current density 25A / dm³. 2 Electroplating time: 45 minutes.

[0275] Example 7: Preparation of plating solution and electroplating process

[0276] The formulation and preparation method of the plating solution in this embodiment are as follows:

[0277] The formulation of the plating solution is as follows:

[0278] Copper sulfate pentahydrate 250g / L

[0279] Sulfuric acid 50g / L

[0280] Chloride ions (derived from hydrochloric acid) 60 mg / L

[0281] New leveling agent A2 1.5g / L

[0282] 3-(benzothiazole-2-mercapto)-propane sulfonate 0.3 g / L

[0283] Polyethylene glycol 6000 1.2 g / L, and

[0284] Polyethyleneimine quaternary ammonium salt 0.15 g / L.

[0285] Polyethyleneimine quaternary ammonium salt (model: TPyP-Et, see Tetrahedron, 2024, 159: 134011.)

[0286] The above-mentioned plating solution formulation was prepared using the preparation method of Example 1.

[0287] The electroplating process parameters for the plating solution are: temperature 40±2℃, current density 15A / dm³. 2 Electroplating time: 25 minutes.

[0288] Comparative Example 1: Preparation of Plating Solution and Electroplating Process

[0289] The difference between this comparative example and Example 1 is that the novel leveling agent A1 is not added, while the rest of the composition and preparation method are the same as in Example 1.

[0290] Comparative Example 2: Preparation of Plating Solution and Electroplating Process

[0291] The difference between this comparative example and Example 2 is that the novel leveling agent A2 is not added; the rest of the composition and preparation method are the same as in Example 2.

[0292] Comparative Example 3: Preparation of Plating Solution and Electroplating Process

[0293] The difference between this comparative example and Example 3 is that the novel leveling agent A3 is not added, while the rest of the composition and preparation method are the same as in Example 3.

[0294] Comparative Example 4: Preparation of Plating Solution and Electroplating Process

[0295] The difference between this comparative example and Example 4 is that the novel leveling agent A4 is not added, while the rest of the composition and preparation method are the same as in Example 4.

[0296] Comparative Example 5: Preparation of Plating Solution and Electroplating Process

[0297] The difference between this comparative example and Example 5 is that the novel leveling agent A5 is not added, while the rest of the composition and preparation method are the same as in Example 5.

[0298] Comparative Example 6: Preparation of Plating Solution and Electroplating Process

[0299] The difference between this comparative example and Example 6 is that the novel leveling agent A6 is not added, while the rest of the composition and preparation method are the same as in Example 6.

[0300] Comparative Example 7

[0301] The difference between this comparative example and Example 2 is that the novel leveling agent A2 in the plating solution is replaced by an equal amount of PEI (polyethyleneimine, CAS: 9002-98-6), while the remaining composition and preparation method are the same as in Example 2.

[0302] Comparative Example 8

[0303] The difference between this comparative example and Example 2 is that the novel leveling agent A2 in the plating solution is replaced with an equal amount of commercially available leveling agent polyvinylpyrrolidone (PVP), while the remaining composition and preparation method are the same as in Example 2.

[0304] Comparative Example 9

[0305] The difference between this comparative example and Example 2 is that the novel leveling agent A2 in the plating solution is replaced by an equal amount of leveling agent B1, while the rest of the composition and preparation method are the same as in Example 2.

[0306] The molecular formula of leveling agent B1 is R-CH2-CH2-(NH-CH2-CH2). n-1 -NH-CH2-CH(CH3)-CH2-CH2-SO3H, its structural formula is as follows:

[0307]

[0308] The preparation method of leveling agent B1 is as follows:

[0309] 1 mmol of 4-hydroxy-3-methylbutyric acid and 1.2 mmol of PEI were dissolved in THF solution, and 1.2 mmol of DIAD and 1.2 mmol of PPh3 were added. The mixture was reacted at room temperature for 2 h to obtain leveling agent B1.

[0310] 1¹H NMR (-NHCH₂CH₂-: 2.8-3.5; -CH₃: 0.93; hydrogen on tertiary carbon: 1.45; hydrogen on secondary carbon separated from sulfonic acid group by one carbon atom: 1.65; -SO₃H: 9.6).

[0311] Experimental Example 1: Determination of Electroplating Effect of Plating Solution

[0312] The plating solutions prepared in the examples and comparative examples, as well as the electroplating effects, were tested. The surface morphology of the plating layer was observed using a metallographic microscope, and the TIR value was calculated (see Yang Yanzhang, Chen Zhihua, Xiong Wei, et al. Research on high-speed electroplating of copper pillars for advanced packaging [J]. Printed Circuit Information, 2024, 32(S2): 231-8.). The test results are shown in the appendix. Figure 1 Appendix Figure 2 The results are shown in Table 1;

[0313] Table 1: Electroplating Effect

[0314]

[0315] As can be seen from the results in Table 1, the surface of the copper pillar obtained in the example is very smooth, without any protrusions or depressions (see Appendix). Figure 1 The arch ratio is almost zero, which is almost an ideal state.

[0316] The copper pillars obtained in the comparison showed uneven surfaces with bumps or depressions (see appendix). Figure 2 The arch ratio is also higher than the standard, which does not meet the performance requirements of the copper column.

[0317] Experimental Example 2: Electroplating Efficiency of Plating Solution

[0318] The plating solutions prepared in the examples and comparative examples, as well as the electroplating efficiency, were tested. The electroplating efficiency ( The calculation method for ) is shown in formula (1):

[0319] (1)

[0320] The results obtained using the above measurement and calculation methods are shown in Table 2.

[0321] Table 2: Electroplating efficiency ( )

[0322]

[0323] As shown in Table 2, the novel leveling agent provided by this invention has excellent electroplating effect, with an electroplating efficiency of ≥94%. In contrast, the electroplating efficiency without adding the leveling agent or using commercially available leveling agents is ≤92%, which is relatively low and cannot achieve the technical effect of this invention.

[0324] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0325] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A leveling agent, characterized in that, The leveling agent has the general molecular formula R-CH2-CH2-(NH-CH2-CH2). n-1 -NH-CH(R 1 -SH)-R 2 PEI compounds with -SO3H, or their salts and stereoisomers; In the formula, n is an integer in the range of 25-1000; In the formula, R includes amino groups; In the formula R 1 R 2 Each can independently include alkyl, heteroalkyl, aryl, cycloalkyl, or heterocyclic groups; The preparation method of the PEI compound includes the following steps: reacting the first compound A with a PEI compound to prepare the compound; The general molecular formula of the first compound A is HO-CH(R) 1 -SH)-R 2 -SO3H.

2. The leveling agent according to claim 1, characterized in that, The general molecular formula of the PEI class compounds or their salts or stereoisomers further includes at least one of the features shown in (1) to (2) below: (1) The R 1 Including alkyl or heteroalkyl groups; The heteroalkyl group contains one or more of N, O, and S atoms; The alkyl group includes C 2- C 10 alkyl; The heteroalkyl group includes C 2- C 10 Heteroalkyl; (2) The R 1 Including aryl, heterocyclic, or cycloalkyl groups; The aryl, cycloalkyl, or heterocyclic groups each independently include monocyclic, fused, spirocyclic, or bridged rings.

3. The leveling agent according to claim 2, characterized in that, The R 1 It includes aryl groups, wherein the aryl group is a benzene ring or a naphthalene ring.

4. The leveling agent according to claim 1, characterized in that, The general molecular formula of the PEI class compounds or their salts or stereoisomers further includes at least one of the features shown in (1) to (2) below: (1) The R 2 Including alkyl or heteroalkyl groups; The heteroalkyl group contains one or more of N, O, and S atoms; The alkyl group includes C 2- C 10 alkyl; The heteroalkyl group includes C 2- C 10 Heteroalkyl; (2) The R 2 Including aryl, heterocyclic, or cycloalkyl groups; The aryl, cycloalkyl, or heterocyclic groups each independently include monocyclic, fused, spirocyclic, or bridged rings.

5. The leveling agent according to claim 4, characterized in that, The R 2 It includes aryl groups, wherein the aryl group is a benzene ring or a naphthalene ring.

6. The leveling agent according to any one of claims 1 to 5, characterized in that, The general molecular formula of the PEI-type compounds or their salts and stereoisomers is R-CH2-CH2-(NH-CH2-CH2). n-1 -NH-CH(CH2-SH)-CH2-SO3H; In the formula, n is an integer in the range of 25-1000; In the formula, R includes amino groups.

7. A leveling agent, characterized in that, The leveling agent has the general molecular formula R-CH2-CH2-(NH-CH2-CH2). n-1 -NH-CH2-CH(SH)-CH2-CH2-SO3H, R-CH2-CH2-(NH-CH2-CH2) n-1 -NH-CH(CH3)-CH(SH)-CH2-CH2-SO3H or R-CH2-CH2-(NH-CH2-CH2) n-1 PEI compounds of -NH-CH2-CH2-CH(SH)-CH2-CH2-CH2-SO3H, or their salts and stereoisomers; In the formula, n is an integer in the range of 25-1000; In the formula, R includes amino groups; The preparation method of the PEI compound includes the following steps: reacting the first compound A with a PEI compound to prepare the compound; The first compound A is selected from 4-hydroxy-3-mercaptobutyric acid, 4-hydroxy-3-mercaptopentylsulfonic acid, or 6-hydroxy-4-mercaptohexylsulfonic acid.

8. A method for preparing a leveling agent, characterized in that, Includes the following steps: The first compound A reacts with the PEI compound to prepare a leveling agent; The general molecular formula of the first compound A is HO-CH(R) 1 -SH)-R 2 -SO3H; In the formula R 1 R 2 Each can independently include alkyl, heteroalkyl, aryl, cycloalkyl, or heterocyclic groups; The general molecular formula of the PEI compound is R-(CH2CH2NH). n -H; In the formula, n is an integer in the range of 25-1000; In the formula, R includes amino groups.

9. The method for preparing the leveling agent according to claim 8, characterized in that... In the general molecular formula of the first compound A, R 1 Including C 2- C 10 alkyl; In the general formula of the first compound A, -SH and -OH are each independently substituted on different C atoms in the alkyl group; The number of carbon atoms separating the hydroxyl group and the thiol group is ≥2.

10. A plating solution, characterized in that, The plating solution comprises a metal salt and a leveling agent, wherein the leveling agent comprises the leveling agent according to any one of claims 1 to 6 or the leveling agent according to claim 7, or the leveling agent prepared by the preparation method according to claim 8 or 9. The metal salt includes copper salt.

11. The plating solution according to claim 10, characterized in that, The plating solution also satisfies at least one of the following (1) to (3): (1) The amount of metal salt added to the plating solution is 180g / L-300g / L; (2) The amount of leveling agent added to the plating solution is 0.001 g / L-0.8 g / L; (3) The composition of the plating solution includes 180g / L-300g / L copper sulfate, 10g / L-200g / L sulfuric acid, 30mg / L-80mg / L chloride ions, 0.001g / L-0.5g / L sulfur-containing compounds, 0.01g / L-6g / L polyethylene glycol, 0.001g / L-0.5g / L quaternary ammonium salt and 0.001g / L-0.8g / L leveling agent.

12. The plating solution according to claim 11, characterized in that, The plating solution also satisfies at least one of the following (1) to (4): (1) The copper sulfate includes anhydrous copper sulfate and / or copper sulfate hydrate; (2) The sulfur-containing compounds include one or more of the following: 3-(benzothiazol-2-mercapto)-propane sulfonate, isothiourea propane sulfonate inner salt, propane sulfonate pyridinium salt, N-propane benzene sulfonate, bis(3-sulfopropyl sodium) disulfide, polydisulfide dipropane sulfonate, 3-mercaptopropane sulfonate, N,N-dimethyl-dithioformamide propane sulfonate, 3-thio-isothiourea onium propyl sulfonate, alkyl polyalkoxypropyl sulfonate, linear epoxy naphthol propyl sulfonate, thiourea, 1,3-dimethylthiourea, trimethylthiourea, diethylthiourea and allylthiourea; (3) The molecular weight of the polyethylene glycol is 400-40000; (4) The composition of the plating solution includes 250g / L-300g / L copper sulfate, 10g / L-50g / L sulfuric acid, 40mg / L-60mg / L chloride ions, 0.08g / L-0.3g / L sulfur-containing compounds, 0.08g / L-1.8g / L polyethylene glycol, 0.03g / L-0.15g / L quaternary ammonium salt and 0.08g / L-0.8g / L leveling agent.

13. The plating solution according to claim 12, characterized in that, The copper sulfate hydrate includes one or more of CuSO4·H2O, CuSO4·3H2O, and CuSO4·5H2O.

14. An electroplating process, characterized in that, Electroplating is performed using the plating solution described in any one of claims 10 to 13; Provide a substrate with the surface to be electroplated; The substrate is brought into contact with the plating solution; Electroplating is performed by applying an electric current between the substrate and the anode; The current density is 0.2 A / dm³. 2 -40A / dm 2 ; The temperature of the plating solution is 10℃-50℃.

15. A coating, characterized in that, The coating is obtained by electroplating the substrate surface with the plating solution described in any one of claims 10 to 13; or by electroplating the substrate surface using the electroplating process described in claim 14.

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