Novel leveling agent, plating solution and application of novel leveling agent and plating solution in electroplating process

Abstract

The invention provides a novel leveling agent, a plating solution and an application of the novel leveling agent and the plating solution in an electroplating process. The novel leveling agent is a PEI compound with a molecular general formula R-CH2-CH2-(NH-CH2-CH2) n-1-NH-CH (R1-SH)-R2-SO3H, or a salt and a stereoisomer of the PEI compound, in the formula, n is an integer in the range of 25-1000; r in the formula comprises a group containing one or more of C, N, O, S and H atoms; r1 and R2 in the formula respectively and independently comprise alkyl, heteroalkyl, aryl, cycloalkyl or heterocyclic radical. The novel leveling agent provided by the invention is used for electroplating, can remarkably improve the uniformity of a plating layer and reduce bulges or recesses on the surface of the plating layer, is particularly suitable for remarkably improving the flatness of the plating layer under high current density, is high in electroplating speed, and greatly improves the reliability and the production efficiency of a packaged object.

Description

Technical Field

[0001] The present invention relates to the technical field of electroplating, and in particular to a novel leveling agent, a plating solution and applications thereof in electroplating processes. Background Art

[0002] As the electronics packaging industry places higher demands on the conductivity and mechanical properties of printed circuit boards, electroplating has become a key foundational technology for advanced packaging. However, current electroplating processes face several challenges, including uneven and uneven coating surfaces over large areas, resulting in uneven solder joint strength, which in turn affects package reliability. On the one hand, uneven coating can lead to differences in the bonding strength between the coating and the substrate, as well as between different parts of the coating itself. Furthermore, uneven coating can generate uneven internal stress during curing and use. When subjected to external forces, the coating is prone to peeling, flaking, and cracking, compromising the integrity of the package structure. Over time and in response to the changing operating environment, this can ultimately lead to package failure and compromise the stability of the entire package. On the other hand, uneven coating can lead to differences in resistance across different locations, potentially causing uneven current distribution and localized overheating, preventing the package from achieving good conductivity. Alternatively, it can create areas of excessive thickness or thinness in certain regions, compromising the insulation performance of the package, impacting the proper operation of electronic components within the package, and potentially causing safety issues such as leakage, or even component damage.

[0003] Especially at high current densities, the current distribution on the electrode surface is significantly affected by factors such as electrode shape, electrode spacing, and deposition rate, which can easily lead to uneven coating surfaces and the aforementioned phenomenon. Therefore, solving these problems during high current density electroplating processes is crucial to better address the current rapid development of electronic packaging technology. Summary of the Invention

[0004] Based on this, it is necessary to provide a leveling agent and plating solution that can achieve rapid electroplating under high current density conditions and produce a uniform and reliable coating, as well as their application in electroplating processes.

[0005] In the first aspect, the present invention provides a novel leveler having a molecular formula of R-CH2-CH2-(NH-CH2-CH2) n-1 -NH-CH(R 1 -SH)-R 2 -SO3H PEI compounds, or salts or stereoisomers thereof;

[0006] Wherein n is an integer in the range of 25-1000;

[0007] wherein R comprises a group containing one or more of C, N, O, S and H atoms;

[0008] Where R 1 、R 2 Each independently includes an alkyl group, a heteroalkyl group, an aryl group, a cycloalkyl group, or a heterocyclyl group.

[0009] In some embodiments, the molecular formula of the novel leveler further includes at least one of the following features (1) to (5):

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

[0011] (2) 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) R 1 including aryl, heterocyclic or cycloalkyl groups;

[0016] Optionally, the aryl, cycloalkyl or heterocyclic group each independently includes a monocyclic ring, a condensed ring, a spirocyclic ring or a bridged ring;

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

[0018] (4) 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) R 2 including aryl, heterocyclic or cycloalkyl groups;

[0023] Optionally, the aryl, cycloalkyl or heterocyclic group each independently includes a monocyclic ring, a condensed ring, a spirocyclic ring or a bridged ring;

[0024] Further optionally, the aryl group is a benzene ring or a naphthalene ring.

[0025] In some embodiments, the molecular formula of the novel leveler is 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] Wherein n is an integer in the range of 25-1000;

[0027] Wherein R includes a group containing one or more of C, N, O, S and H atoms.

[0028] In a second aspect, the present invention further provides a method for preparing the novel leveler, comprising the following steps: reacting a first compound A with a PEI compound to prepare the novel leveler;

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

[0030] Where R 1 、R 2 each independently comprises an alkyl group, a heteroalkyl group, an aryl group, a cycloalkyl group, or a heterocyclyl group;

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

[0032] Wherein n is an integer in the range of 25-1000;

[0033] Wherein R includes a group containing one or more of C, N, O, S and H atoms.

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

[0035] Optionally, the molecular formula of the first compound A is HO-(R 1-SH) in which -SH and -HO are independently substituted on different C in the alkyl group;

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

[0037] In a third aspect, the present invention further provides a plating solution, comprising a metal salt and a leveling agent, wherein the leveling agent comprises 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 the metal salt added to the plating solution is 180 g / L-300 g / L;

[0041] (2) The amount of the 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 of copper sulfate, 10g / L-200g / L of sulfuric acid, 30mg / L-80mg / L of chloride ions, 0.001g / L-0.5g / L of sulfur-containing compounds, 0.01g / L-6g / L of polyethylene glycol, 0.001g / L-0.5g / L of quaternary ammonium salt and 0.001g / L-0.8g / L of 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 compound includes one or more of 3-(benzothiazole-2-mercapto)-propane sulfonate, isothiourea propanesulfonic acid inner salt, propane sulfonic acid pyridinium salt, N-propanebenzenesulfonate, bis(3-sulfopropyl sodium) disulfide, polydisulfide propane sulfonate, 3-mercaptopropane sulfonate, N,N-dimethyl-dithiocarboxamide propane sulfonate, 3-sulfo-isothiourea propyl sulfonate, alkyl polyalkoxy propyl sulfonate, straight polyepoxy 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 of copper sulfate, 10g / L-50g / L of sulfuric acid, 40mg / L-60mg / L of chloride ions, 0.08g / L-0.3g / L of sulfur-containing compounds, 0.08g / L-1.8g / L of polyethylene glycol, 0.03g / L-0.15g / L of quaternary ammonium salt and 0.08g / L-0.8g / L of leveling agent.

[0049] In a fourth aspect, the present invention further provides an electroplating process, wherein the electroplating is performed using the plating solution provided in the third aspect;

[0050] providing a substrate having a surface to be electroplated;

[0051] contacting the substrate with the plating solution;

[0052] applying an electric current between the substrate and the anode for electroplating;

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

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

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

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

[0057] The novel leveler of the present invention is a PEI-type compound with a specific molecular formula, or its salt or stereoisomer. Different adsorption sites can be selected according to the strength of convection and the current density. Nitrogen-containing groups are preferentially adsorbed on the surface of the coating at locations with strong convection and high current density, and the deposition rate is suppressed. Sulfur-containing groups are preferentially adsorbed on the surface of the coating at locations with weak convection and low current density, and the deposition rate is enhanced. Selective adsorption on the surface of the coating is achieved to adjust the deposition rate in different areas to meet the requirements for coating flatness. It also has good electroplating performance at high current density, can quickly electroplate and obtain a uniform, flat coating. The present invention develops compounds with specific structures to overcome the defects 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, which is a significant improvement over traditional technologies. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 The surface conditions of the copper pillars after electroplating using the plating solutions of Examples 1-6 of the present invention are shown.

[0059] Figure 2 The surface conditions of the copper pillars after electroplating using the plating solutions of Comparative Examples 1-6 of the present invention are shown.

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

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

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

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

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

[0065] Figure 8 This is the NMR spectrum of the new leveler A1 of the present invention.

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

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

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

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

[0070] Figure 13 This is the NMR spectrum of the new leveling agent A6 of the present invention. DETAILED DESCRIPTION

[0071] To facilitate understanding of the present invention, the following provides a more comprehensive description of the technical solutions of the present invention by referring to preferred embodiments 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 provide a more thorough and comprehensive understanding of the disclosure of the present invention.

[0072] It should be noted that the experimental methods in the following examples of the present invention, where specific conditions are not specified, are generally carried out under conventional conditions or conditions recommended by the manufacturers. The various commonly used chemical reagents used in the examples are all commercially available products.

[0073] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one skilled in the art to which this invention pertains. The terms used in this specification of the present invention are for the purpose of describing specific embodiments only and are not intended to limit the present 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 specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0075] The term "heterocyclyl" refers to a cycloalkyl group in which at least one carbon atom is replaced by a non-carbon atom, which may be an N atom, an O atom, an S atom, or the like, and may be a saturated ring or a partially unsaturated ring. Phrases containing this term, for example, "C4-C9 heterocyclyl" refer to a heterocyclyl group containing 4-9 carbon atoms, each occurrence of which may be independently C4 heteroalkyl, C5 heteroalkyl, C6 heteroalkyl, C7 heteroalkyl, C8 heteroalkyl, or C9 heteroalkyl. Suitable examples include, but are not limited to, dihydropyridyl, tetrahydropyridyl (piperidyl), tetrahydrothienyl, sulfur-oxidized tetrahydrothienyl, tetrahydrofuranyl, tetrahydroquinolinyl, tetrahydroisoquinolinyl, and dihydroindole.

[0076] The term "cycloalkyl" refers to a non-aromatic hydrocarbon containing ring carbon atoms, which can be a monocyclic alkyl, a spirocyclic alkyl, or a bridged cycloalkyl. Phrases containing this term, for example, "C3-C9 cycloalkyl" refers to a cycloalkyl containing 3-9 carbon atoms, each occurrence of which can be independently C3 cycloalkyl, C4 cycloalkyl, C5 cycloalkyl, or C6 cycloalkyl. Suitable examples include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, and cycloheptyl. In addition, "cycloalkyl" can also contain one or more double bonds. Representative examples of cycloalkyl 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 a hydrogen atom. It can be a monocyclic aromatic group, a condensed aromatic group, or a polycyclic aromatic group. For polycyclic aromatic groups, at least one of the rings is an aromatic ring system. For example, "C5~C 20 "Aryl" refers to an aromatic group containing 5 to 20 carbon atoms, each occurrence of which can be independently C5 aromatic, C6 aromatic, C 10 Aryl, C 14 Aryl, C 18 Aryl or C20 Aryl. Suitable examples include, but are not limited to, benzene, biphenyl, naphthalene, anthracene, phenanthrene, perylene, triphenylene, and their derivatives. It is understood that multiple aryl groups may 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, triarylamine, and diaryl ether systems, which are also included in the definition of aryl.

[0078] The term "alkyl" refers to a saturated hydrocarbon containing primary (normal) carbon atoms, secondary carbon atoms, tertiary carbon atoms, quaternary carbon atoms, or combinations thereof. Phrases containing this term, for example, "C1-C9 alkyl" refers to an alkyl group containing 1 to 9 carbon atoms, each occurrence of which 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), and the like.

[0079] The term "heteroalkyl" refers to an alkyl group in which at least one carbon atom is replaced by a non-carbon atom, such as an N atom, an O atom, an S atom, or the like. For example, if the carbon atom connected to the parent core structure in the alkyl group 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 not connected to the parent core structure in the alkyl group 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 alkylthiol group (e.g., -CH2CH2-SH). Phrases containing this term, for example, heteroalkyl containing 1 to 9 carbon atoms, can, at each occurrence, independently be C2 heteroalkyl, C3 heteroalkyl, C4 heteroalkyl, C5 heteroalkyl, C7 heteroalkyl, C8 heteroalkyl, or C9 heteroalkyl.

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

[0081] Electroplating is actually a metal electrodeposition process, which uses the principle of electrolysis to obtain a metal deposit layer on a solid surface. It is a process that uses electrolysis to attach a layer of metal film to the surface of the 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 cathode current density range of the metal, improve the appearance of the coating, and increase the anti-oxidation stability of the solution.

[0083] Electroplating additives refer to a variety of chemical substances added to the plating bath during the electroplating process to improve the quality of the coating. Based on their function in the plating bath, they can be categorized as complexing agents, brighteners and auxiliary brighteners, leveling agents, pinhole removers, dispersants, wetting agents, and smoke suppressants.

[0084] Electroplating additives are an essential component of the plating solution and play an irreplaceable role in the electroplating process. Additives can effectively improve the current distribution during the electroplating process, enhance the throwing power of the plating solution, and influence the transport and electrocrystallization of metal ions from the solution bulk to the reaction interface, thereby changing the electrochemical deposition rate in microscopic concave and convex areas of the plate surface.

[0085] A leveler is a substance added to the electroplating solution to improve the flatness of the coating, making the obtained coating smoother than the substrate surface.

[0086] The "PEI" involved in the present invention includes polyalkylimine compounds, but is not limited to substances named such as polyetherimide, polyethyleneimine, polyetherimide, and polyethyleneimine.

[0087] The "PEI compounds" involved in the present invention include a class of derivative compounds having a polyalkylimine skeleton, and are not limited to skeletons containing names such as polyetherimide, polyethyleneimine, polyetherimide, and polyethyleneimine.

[0088] Conventional electroplating processes produce uneven coatings, resulting in reduced coating flatness. Furthermore, conventional electroplating solutions require a specific, low current density and are prone to failure beyond this current density, impacting the plating process and coating performance, ultimately affecting the performance of the packaged object. Furthermore, conventional electroplating speeds are slow, impacting production efficiency. Therefore, the present invention addresses these shortcomings of conventional electroplating processes and develops a plating solution additive.

[0089] In the first aspect, the present invention provides a novel leveler having a molecular formula of R-CH2-CH2-(NH-CH2-CH2) n-1 -NH-CH(R 1 -SH)-R2 -SO3H PEI compounds, or salts or stereoisomers thereof;

[0090] Wherein n is an integer in the range of 25-1000;

[0091] wherein R comprises a group containing one or more of C, N, O, S and H atoms;

[0092] Where R 1 、R 2 Each independently includes an alkyl group, a heteroalkyl group, an aryl group, a cycloalkyl group, or a heterocyclyl group.

[0093] The novel leveler of the present invention has R-CH2-CH2-(NH-CH2-CH2) n-1 -NH-CH(R 1 -SH)-R 2 The molecular formula of -SO3H enables the selection of different adsorption sites based on the strength of convection and current density. Nitrogen-containing groups preferentially adsorb on the coating surface at locations with strong convection and high current density, suppressing the deposition rate. In locations with weak convection and low current density, sulfur-containing groups preferentially adsorb on the coating surface, enhancing the deposition rate. Through the selective adsorption of this type of material structure on the coating surface, the deposition rate in different areas is adjusted to meet the requirements for coating flatness. This significantly increases the current density during the electroplating process, achieving a uniform and reliable coating even at high current density. This also greatly improves the electroplating speed and reduces the cost of the electroplating process.

[0094] In some embodiments, the chemical formula of the novel leveler is:

[0095]

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

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

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

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

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

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

[0102] Optionally, the aryl, cycloalkyl or heterocyclic group each independently includes a monocyclic ring, a condensed ring, a spirocyclic ring or a bridged ring;

[0103] Further optionally, the aryl group is a benzene ring or a naphthalene ring.

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

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

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

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

[0108] In some embodiments, R in the molecular formula of the novel leveler 2 These include aryl, heterocyclic or cycloalkyl groups.

[0109] In some embodiments, the aryl, cycloalkyl, or heterocyclyl 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 molecular formula of the novel leveler is 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] Wherein n is an integer in the range of 25-1000;

[0113] Wherein R includes a group containing one or more of C, N, O, S and H atoms.

[0114] The novel leveling agent provided by the present 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 further provides a method for preparing the novel leveler provided in the first aspect, comprising the following steps: reacting a first compound A with a PEI compound to prepare a novel leveler;

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

[0117] Where R 1 、R 2 each independently comprises an alkyl group, a heteroalkyl group, an aryl group, a cycloalkyl group, or a heterocyclyl group;

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

[0119] Wherein n is an integer in the range of 25-1000;

[0120] Wherein R includes a group containing one or more of C, N, O, S and H atoms.

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

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

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

[0124] In some embodiments, the number of carbon atoms between the hydroxyl group and the thiol group is greater than or equal to 2.

[0125] As non-limiting examples, the first compound A includes 2-hydroxy-3-mercaptopropanesulfonic acid, 4-hydroxy-3-mercaptobutanesulfonic acid, 4-hydroxy-3-mercaptopentanesulfonic 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 preparation method of the novel leveler includes: reacting the first compound A with a PEI compound, a coupling agent, and an accelerator to prepare the novel leveler.

[0127] In some embodiments, the molar ratio of the first compound A to the PEI compound is 1:(0.5-2), including but 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 any two of the foregoing, and any value within the range.

[0128] In some embodiments, the molar ratio of the first compound A to the PEI compound, the coupling agent, and the accelerator is 1:(0.5-2):(0.8-1.5):(0.8-1.5). Non-limiting examples include, but are 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 any two of the foregoing, and any value within that range.

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

[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 to prepare a novel leveler.

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

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

[0133] In some embodiments, the accelerator includes one or more of organic phosphines, aza-type compounds, other phosphine 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, and triphenylphosphine iodide.

[0135] In a third aspect, the present invention further 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 the novel leveling agent prepared by the preparation method provided in the second aspect;

[0136] The novel leveler has R-CH2-CH2-(NH-CH2-CH2) n-1 -NH-CH(R 1 -SH)-R 2 -SO3H molecular formula;

[0137] Wherein n is an integer in the range of 10-200;

[0138] wherein R comprises a group containing one or more of C, N, O, S and H atoms;

[0139] Where R 1 、R 2 Each independently includes an alkyl group, a heteroalkyl group, an aryl group, a cycloalkyl group, or a heterocyclyl group.

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

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

[0142] In some embodiments, the amount of the leveler added to the plating solution is 0.001 g / L-0.8 g / L, including, but 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 a range formed by any two of the foregoing, and any value within the range.

[0143] In some embodiments, 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 salts, and 0.001g / L-0.8g / L leveling agents.

[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; further, the present invention uses a plating solution containing CuSO4·5H2O to 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 propanesulfonic acid inner salt, propanesulfonic acid pyridinium salt, N-propanebenzenesulfonate, bis(3-sulfopropyl sodium) disulfide, polydisulfide propanesulfonate, 3-mercaptopropanesulfonate, N,N-dimethyl-dithiocarboxamide propanesulfonate, 3-sulfo-isothiourea propyl sulfonate, alkyl polyalkoxy propyl sulfonate, straight polyepoxy naphthol propyl sulfonate, thiourea, 1,3-dimethylthiourea, trimethylthiourea, diethylthiourea and allylthiourea; further, the present invention uses 3-(benzothiazole-2-mercapto)-propane sulfonate and / or isothiourea propanesulfonic acid inner salt to better achieve the technical effects of the present invention.

[0147] In some embodiments, the molecular weight of the polyethylene glycol is 400-40,000, including but not limited to 400, 800, 1,000, 2,000, 4,000, 6,000, 8,000, 10,000, 20,000, 30,000, 40,000 or a range formed by any two of the foregoing and any value within the range; further, the present invention uses polyethylene glycol with a molecular weight of 6,000-10,000 to better achieve the technical effects of the present invention.

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

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

[0150] As non-limiting examples, modified quaternary ammonium salts include, but are not limited to, polyethyleneimine quaternary ammonium salts selected from one or more of polyethyleneimine chloride, polyethyleneimine bromide, polyethyleneimine methylsulfate, and polyethyleneimine methoxylate, HACC, TPyP-Et, BZC, and / or PQ.

[0151] In some embodiments, 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 leveler.

[0152] The plating solution prepared by the present invention has the function of selective adsorption on the surface of the coating to adjust the deposition rate of different areas, thereby meeting the requirements of the coating flatness and improving the reliability of the packaged object.

[0153] In a fourth aspect, the present invention further provides an electroplating process, wherein the electroplating is performed using the plating solution provided in the third aspect;

[0154] providing a substrate having a surface to be electroplated;

[0155] contacting the substrate 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 0.2A / dm 2 -40A / dm 2 .

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

[0159] In a fifth aspect, the present invention further provides a coating, which is obtained by electroplating the above-mentioned plating solution on the surface of the substrate; or by electroplating using the electroplating process provided in the fourth aspect.

[0160] For experimental parameters not specified in the following specific examples, reference is made to the guidance given in this application document, and reference may also be made to experimental manuals in the art or other experimental methods known in the art, or to the experimental conditions recommended by the manufacturer.

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

[0162] The models and sources of some reagents and raw materials involved in the examples 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-mercaptopentanesulfonic 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-mercaptobutanesulfonic acid: 0.1 mol of 3,4-epoxy-1-butene is added as the starting material, 10 mL of pyridine and 50 mL-100 mL of dichloromethane are added, and 0.11 mol of chlorosulfonic acid is slowly added dropwise at -5°C to 5°C. The reaction is allowed to proceed for 2-3 hours to obtain 3,4-epoxy-1-butanesulfonic acid. 0.1 mol of 3,4-epoxy-1-butanesulfonic acid is added as the starting material, 0.1 mmol-0.2 mmol of p-toluenesulfonic acid or triethylamine is used as the catalyst, and 50 mL-100 mL of DMF is used as the solvent. 0.3 mol-0.5 mol of hydrogen sulfide gas is introduced at 30°C-50°C for 3-8 hours. After completion of the reaction, 4-hydroxy-3-mercaptobutanesulfonic acid is obtained, and its NMR data are as follows: 1 H 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: 0.1 mol of 1,3-pentadiene is added to 120-150 mL of dichloromethane at 0-5°C for 3-6 hours to produce 3,4-epoxy-1-pentene. Chlorosulfonic acid is added dropwise to 0.1 mol of 3,4-epoxy-1-pentene, using 0.12-0.15 mol of chlorosulfonic acid as the sulfonating agent and 50-100 mL of dichloromethane as the solvent at 0-10°C. After the addition is complete, the mixture is heated to room temperature and the reaction is continued for 2-4 hours. After the reaction is complete, the mixture is hydrolyzed with ice water and extracted to produce 3,4-epoxy-1-pentanesulfonic acid. 0.1 mol of 3,4-epoxy-1-pentanesulfonic acid is used as the raw material, 100 mL-150 mL of water is used as the solvent, 0.12 mol-0.15 mol of sodium hydrosulfide is added at 40-60°C, and the reaction is carried out for 3-6 hours. After the reaction is completed, the mixture is cooled and acidified with 2 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 H 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: 0.1 mol of 1,3,5-hexatriene as the starting material, 100 mL-150 mL of dichloromethane as the solvent, 0.12 mol-0.15 mol of concentrated sulfuric acid is added dropwise at 0-5°C. After the addition is complete, the temperature is raised to room temperature (20-25°C) and the reaction is allowed to proceed for 3-6 hours. After the reaction is complete, the mixture is poured into crushed ice to terminate the reaction, yielding 3,5-diene-hexanesulfonic acid. Alternatively, 0.1 mol of 3,5-diene-hexanesulfonic acid as the starting material, 5%-10% benzoyl peroxide (0.005 mol-0.01 mol) as the initiator, and 150 mL-200 mL of dichloromethane as the solvent, 0.12 mol-0.15 mol of hydrogen sulfide gas is introduced at 50-60°C for 8-12 hours, yielding 4-mercapto-5-ene-hexanesulfonic acid. Using 0.1 mol of 4-mercapto-5-ene-hexanesulfonic acid as the raw material, 0.12 mol-0.15 mol of sodium borohydride as the reducing agent, 0.2 mol-0.3 mol of sodium hydroxide to adjust the alkalinity, and 100 mL-150 mL of water as the solvent, the reaction was carried out at 0°C-5°C 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 H 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: 0.1 mol of p-styrenesulfonic acid is used as the starting material, 0.12 mol-0.15 mol of m-chloroperbenzoic acid is used as the oxidant, and 150 mL-200 mL of dichloromethane is used as the solvent. The reaction is carried out at 0-5°C for 2-4 hours. After the reaction, a saturated sodium sulfite solution is added to remove the remaining oxidant to obtain p-oxiranebenzenesulfonic acid. Alternatively, 0.1 mol of p-oxiranebenzenesulfonic acid is used as the starting material, 0.12 mol-0.15 mol of sodium hydrosulfide is used as the reactant, and 100 mL-150 mL of ethanol and 50 mL-100 mL of water are used as the mixed solvent. The reaction is carried out at 40-50°C for 4-6 hours. After the reaction, the pH is adjusted to 6-7 with dilute hydrochloric acid to obtain 4-(1-hydroxy-2-mercaptoethyl)benzenesulfonic acid. Its NMR data are as follows: 1 H NMR (OH: 5.17. SH: 1.4. SO3H: 8.5. CH (connected OH): 5.19. CH (phenyl ring): 7.63, 7.83.), see Appendix Figure 6 .

[0170] Preparation of 6-(1-hydroxy-2-mercaptoethyl)naphthalene-2-sulfonic acid: 0.1 mol of 6-vinylnaphthalene as the starting material and 0.12-0.15 mol of concentrated sulfuric acid as the sulfonating agent are reacted at 50-80°C for 2-4 hours. After completion of the reaction, the reaction solution is cooled, poured into ice water, diluted, and the pH is adjusted to neutral with sodium carbonate solution to obtain 6-vinylnaphthalene-2-sulfonic acid. Alternatively, 0.1 mol of 6-vinylnaphthalene-2-sulfonic acid as the starting material and 0.12-0.15 mol of m-chloroperbenzoic acid as the epoxidizing agent are used in 150-200 mL of dichloromethane as the solvent. The reaction is carried out at 0-5°C for 2-4 hours. After completion of the reaction, saturated sodium sulfite solution is added to remove the remaining oxidant to obtain 6-(oxiranyl)naphthalene-2-sulfonic acid. Using 0.1 mol of 6-(oxiranyl)naphthalene-2-sulfonic acid as the raw material, 0.12 mol-0.15 mol of sodium hydrosulfide as the reactant, and 100 mL-150 mL of water and 100 mL-150 mL of ethanol as the mixed solvent, the reaction was carried out at 30-50°C 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 H NMR (OH: 5.17. SH: 1.4. SO3H: 8.5. CH (connected OH): 5.19. CH (phenyl ring): 7.48, 7.71, 7.90, 8.09, 8.37, 8.73.), see Appendix Figure 7 .

[0171] Preparation of new leveling agent:

[0172] New leveler A1: 1 mmol of 2-hydroxy-3-mercaptopropanesulfonic acid and 1.2 mmol of PEI were dissolved in THF solution, 1.2 mmol of DIAD and 1.2 mmol of PPh3 were added, and the reaction was carried out at room temperature for 2 h to obtain leveler A1.

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

[0174]

[0175] Its NMR data are: 1 H NMR (SH: 1.3. SO3H: 8.4. NH (-NHCH2CH2-): 1.5. CH2 (-NHCH2CH2-): 2.5-2.7). For details, see the attached Figure 8 .

[0176] New leveler A2: 1 mmol 4-hydroxy-3-mercaptobutanesulfonic acid and 1.2 mmol PEI were dissolved in THF solution, 1.2 mmol DIAD and 1.2 mmol PPh3 were added, and the reaction was carried out at room temperature for 2 h to obtain leveler A2.

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

[0178]

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

[0180] New leveler A3: 1 mmol 4-hydroxy-3-mercaptopentanesulfonic acid and 1.2 mmol PEI were dissolved in THF solution, 1.2 mmol DIAD and 1.2 mmol PPh3 were added, and the reaction was carried out at room temperature for 2 h to obtain leveler A3.

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

[0182]

[0183] Its NMR data are: 1 H NMR (SH: 1.3. SO3H: 8.5. NH (-NHCH2CH2-): 1.5. CH2 (-NHCH2CH2-): 2.5~2.7. CH3: 1.06.), see the attached Figure 10 .

[0184] New leveler A4: 1 mmol of 6-hydroxy-4-mercaptohexanesulfonic acid and 1.2 mmol of PEI were dissolved in THF solution, 1.2 mmol of DIAD and 1.2 mmol of PPh3 were added, and the reaction was carried out at room temperature for 3 hours to obtain leveler A4.

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

[0186]

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

[0188] New leveler A5: 1 mmol of 4-(1-hydroxy-2-mercaptoethyl)benzenesulfonic acid and 1.2 mmol of PEI were dissolved in THF solution, 1.3 mmol of DIAD and 1.3 mmol of PPh3 were added, and the reaction was carried out at room temperature for 3 h to obtain leveler A5.

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

[0190]

[0191] Its NMR data are: 1 H 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 the attached Figure 12 .

[0192] New leveler A6: 1 mmol of 6-(1-hydroxy-2-mercaptoethyl)naphthalene-2-sulfonic acid and 1.2 mmol of PEI were dissolved in THF solution, 1.4 mmol of DIAD and 1.4 mmol of PPh3 were added, and the reaction was carried out at room temperature for 4 h to obtain leveler A6.

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

[0194]

[0195] Its NMR data are: 1 H 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 formula and preparation method of the plating solution of this embodiment are as follows:

[0198] The formula of the plating solution is:

[0199] Copper sulfate pentahydrate 300g / L,

[0200] Sulfuric acid 10g / L,

[0201] Chloride ion (from hydrochloric acid) 40mg / L,

[0202] New leveling agent A1 0.1g / L,

[0203] 3-(Benzothiazole-2-mercapto)-propanesulfonate 0.15 g / L,

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

[0205] Quaternary ammonium salt 0.03g / L.

[0206] Quaternary ammonium salt (Model: HACC, reference Tetrahedron, 2025, 172: 134436.)

[0207] The preparation method of the plating solution is:

[0208] Prepare the raw materials according to the recipe, ensuring that their purity meets the requirements. Add approximately half the volume of deionized water to a clean plating tank. Slowly add the formulated amount of copper sulfate pentahydrate and stir until completely dissolved. Add an appropriate amount of sulfuric acid while stirring. Add chloride ions, then add leveler Al, 3-(benzothiazole-2-mercapto)-propane sulfonate, polyethylene glycol 8000, and a quaternary ammonium salt. Stir thoroughly. Fill the plating solution to 10 L with deionized water and stir thoroughly to prepare the plating solution. Filter the plating solution to remove any impurities. Analyze and test the plating solution to ensure that the content of each component is within the specified range, adjusting it as necessary.

[0209] The process parameters of the electroplating solution are: temperature 20±2°C, current density 8A / dm 2 , electroplating time 45min.

[0210] Example 2: Preparation of Plating Solution and Electroplating Process

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

[0212] The formula of the plating solution is:

[0213] Copper sulfate pentahydrate 250g / L,

[0214] Sulfuric acid 50g / L,

[0215] Chloride ion (from hydrochloric acid) 60mg / L,

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

[0217] 3-(Benzothiazole-2-mercapto)-propanesulfonate 0.3 g / L,

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

[0219] Quaternary ammonium salt 0.15g / L.

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

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

[0222] The process parameters of the electroplating solution are: temperature 40±2℃, current density 15A / dm 2 , electroplating time 25min.

[0223] Example 3: Preparation of Plating Solution and Electroplating Process

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

[0225] The formula of the plating solution is:

[0226] Copper sulfate pentahydrate 250g / L,

[0227] Sulfuric acid 50g / L,

[0228] Chloride ion (from hydrochloric acid) 50mg / L,

[0229] New leveling agent A3 0.5g / L,

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

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

[0232] Quaternary ammonium salt 0.1g / L.

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

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

[0235] The process parameters of the electroplating solution are: temperature 30±2℃, current density 25A / dm 2 , electroplating time 45min.

[0236] Example 4: Preparation of Plating Solution and Electroplating Process

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

[0238] The formula of the plating solution is:

[0239] Copper sulfate pentahydrate 250g / L,

[0240] Sulfuric acid 50g / L,

[0241] Chloride ion (from hydrochloric acid) 50mg / L,

[0242] New leveling agent A4 0.8g / L,

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

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

[0245] Quaternary ammonium salt 0.1g / L.

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

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

[0248] The process parameters of the electroplating solution are: temperature 30±2℃, current density 25A / dm 2 , electroplating time 45min.

[0249] Example 5: Preparation of Plating Solution and Electroplating Process

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

[0251] The formula of the plating solution is:

[0252] Copper sulfate pentahydrate 250g / L,

[0253] Sulfuric acid 50g / L,

[0254] Chloride ion (from hydrochloric acid) 50mg / L,

[0255] New leveling agent A5 0.8g / L,

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

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

[0258] Quaternary ammonium salt 0.1g / L.

[0259] Quaternary ammonium salt (Model: BZC, reference Benzyl-containing quaternary ammonium salt as a new leveler for microvia copper electroplating, Electrochimica Acta, 2022, 429: 141013.)

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

[0261] The process parameters of the electroplating solution are: temperature 35±2℃, current density 40A / dm 2 , electroplating time 45min.

[0262] Example 6: Preparation of Plating Solution and Electroplating Process

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

[0264] The formula of the plating solution is:

[0265] Copper sulfate pentahydrate 250g / L,

[0266] Sulfuric acid 50g / L,

[0267] Chloride ion (from hydrochloric acid) 50mg / L,

[0268] New leveling agent A6 0.5g / L,

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

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

[0271] Quaternary ammonium salt 0.1g / L.

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

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

[0274] The process parameters of the electroplating solution are: temperature 30±2℃, current density 25A / dm 2 , electroplating time 45min.

[0275] Example 7: Preparation of Plating Solution and Electroplating Process

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

[0277] The formula of the plating solution is:

[0278] Copper sulfate pentahydrate 250g / L,

[0279] Sulfuric acid 50g / L,

[0280] Chloride ion (from hydrochloric acid) 60mg / L,

[0281] New leveling agent A2 1.5g / L,

[0282] 3-(Benzothiazole-2-mercapto)-propanesulfonate 0.3 g / L,

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

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

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

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

[0287] The process parameters of the electroplating solution are: temperature 40±2℃, current density 15A / dm 2 , electroplating time 25min.

[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, and the rest of the composition and preparation method are the same as those of 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, and the rest of the composition and preparation method are the same as those of 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, and the rest of the composition and preparation method are the same as those of 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, and the rest of the composition and preparation method are the same as those of 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, and the rest of the composition and preparation method are the same as those of 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, and the rest of the composition and preparation method are the same as those of Example 6.

[0300] Comparative Example 7

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

[0302] Comparative Example 8

[0303] The difference between this comparative example and Example 2 is that the new leveler A2 in the plating solution is replaced by an equal amount of a commercially available leveler polyvinylpyrrolidone (PVP), and the rest of the composition and preparation method are the same as those in Example 2.

[0304] Comparative Example 9

[0305] The difference between this comparative example and Example 2 is that the new leveler A2 in the plating solution is replaced by an equal amount of leveler B1, and the rest of the composition and preparation method are the same as those 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-methylbutanesulfonic acid and 1.2 mmol of PEI were dissolved in THF solution, 1.2 mmol of DIAD and 1.2 mmol of PPh3 were added, and the mixture was reacted at room temperature for 2 h to obtain leveler B1.

[0310] 1H 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] Test Example 1: Determination of electroplating effect of plating solution

[0312] The plating solutions prepared in the examples and comparative examples and the electroplating effects were tested. The surface morphology of the coating 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 copper pillars for advanced packaging [J]. Printed Circuit Information, 2024, 32(S2): 231-8.). The test results are shown in the attached Figure 1 , Attachment Figure 2 As shown in Table 1;

[0313] Table 1: Electroplating effects

[0314]

[0315] From the results in Table 1, it can be seen that the surface of the copper pillar obtained in the embodiment is very flat, without any protrusions or depressions (see Appendix Figure 1 ), the arch rate is almost zero, almost reaching the ideal state.

[0316] The copper pillars obtained in the comparative example have convex or concave surfaces (see Appendix Figure 2 ), the arch rate is also higher than the standard and cannot meet the performance requirements of the copper column.

[0317] Test Example 2: Plating Efficiency of Plating Solution

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

[0319] (1)

[0320] According to the above determination method and calculation method, the results are shown in Table 2;

[0321] Table 2: Plating efficiency ( )

[0322]

[0323] As can be seen from the results in Table 2, the new leveler provided by the present invention has excellent electroplating effect when used in electroplating, with an electroplating efficiency of ≥94%. The electroplating efficiency when no leveler is added or a commercially available leveler is ≤92%, which is relatively low and cannot achieve the technical effect of the present invention.

[0324] The technical features of the above-mentioned embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above-mentioned 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 above-described embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the scope of protection of the patent for this invention shall be determined by the appended claims.

Claims

1. A new leveling agent, characterized in that: The novel leveler has a molecular formula of R-CH2-CH2-(NH-CH2-CH2) n-1 -NH-CH(R 1 -SH)-R 2 -SO3H PEI compounds, or salts or stereoisomers thereof; Wherein n is an integer in the range of 25-1000; wherein R comprises a group containing one or more of C, N, O, S and H atoms; Where R 1 、R 2 Each independently includes an alkyl group, a heteroalkyl group, an aryl group, a cycloalkyl group, or a heterocyclyl group.

2. The novel leveling agent according to claim 1, characterized in that: The molecular formula of the PEI compound or its salt or stereoisomer also includes at least one of the following features (1) to (5): (1) R includes amino, hydroxyl, carboxyl, aldehyde, ester, amide, thiol, cyano, anhydride, sulfonyl, sulfonic acid or hydrogen; (2) R 1 including alkyl or heteroalkyl groups; Optionally, the heteroalkyl group contains one or more of N, O and S atoms; Optionally, the alkyl group includes C 2- C 10 alkyl; Optionally, the heteroalkyl group includes C 2- C 10 heteroalkyl; (3) R 1 including aryl, heterocyclic or cycloalkyl groups; Optionally, the aryl, cycloalkyl or heterocyclic group each independently includes a monocyclic ring, a condensed ring, a spirocyclic ring or a bridged ring; Further optionally, the aryl group is a benzene ring or a naphthalene ring; (4) R 2 including alkyl or heteroalkyl groups; Optionally, the heteroalkyl group contains one or more of N, O and S atoms; Optionally, the alkyl group includes C 2- C 10 alkyl; Optionally, the heteroalkyl group includes C 2- C 10 heteroalkyl; (5) R 2 including aryl, heterocyclic or cycloalkyl groups; Optionally, the aryl, cycloalkyl or heterocyclic group each independently includes a monocyclic ring, a condensed ring, a spirocyclic ring or a bridged ring; Further optionally, the aryl group is a benzene ring or a naphthalene ring.

3. The novel leveling agent according to claim 1 or 2, characterized in that: The molecular formula of the PEI compound or its salt or stereoisomer is 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; Wherein n is an integer in the range of 25-1000; Wherein R includes a group containing one or more of C, N, O, S and H atoms.

4. A method for preparing a novel leveling agent, characterized in that: The following steps are involved: The first compound A reacts with the PEI compound to prepare a new leveling agent; The molecular formula of the first compound A is HO-CH(R 1 -SH)-R 2 -SO3; Where R 1 、R 2 each independently comprises an alkyl group, a heteroalkyl group, an aryl group, a cycloalkyl group, or a heterocyclyl group; The molecular formula of the PEI compound is R-(CH2CH2NH) n -H; Wherein n is an integer in the range of 25-1000; Wherein R includes a group containing one or more of C, N, O, S and H atoms.

5. The preparation method of the novel leveling agent according to claim 4, characterized in that In the molecular formula of the first compound A, R 1 Including C 2- C 10 alkyl; Optionally, the molecular formula of the first compound A is HO-(R 1 -SH) in which -SH and -HO are independently substituted on different C in the alkyl group; Optionally, the number of carbon atoms between the hydroxyl group and the thiol group is ≥2.

6. A plating solution, characterized in that The plating solution comprises a metal salt and a leveler, wherein the leveler comprises the novel leveler according to any one of claims 1 to 3, or the novel leveler prepared by the preparation method according to claim 4 or 5; Optionally, the metal salt comprises a copper salt.

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

8. The plating solution according to claim 7, wherein 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; Optionally, the copper sulfate hydrate includes one or more of CuSO4·H2O, CuSO4·3H2O and CuSO4·5H2O; (2) The sulfur-containing compound includes one or more of 3-(benzothiazole-2-mercapto)-propane sulfonate, isothiourea propanesulfonic acid inner salt, propane sulfonic acid pyridinium salt, N-propanebenzenesulfonate, bis(3-sulfopropyl sodium) disulfide, polydisulfide propane sulfonate, 3-mercaptopropane sulfonate, N,N-dimethyl-dithiocarboxamide propane sulfonate, 3-sulfo-isothiourea propyl sulfonate, alkyl polyalkoxy propyl sulfonate, straight polyepoxy 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 of copper sulfate, 10g / L-50g / L of sulfuric acid, 40mg / L-60mg / L of chloride ions, 0.08g / L-0.3g / L of sulfur-containing compounds, 0.08g / L-1.8g / L of polyethylene glycol, 0.03g / L-0.15g / L of quaternary ammonium salt and 0.08g / L-0.8g / L of leveling agent.

9. An electroplating process, characterized in that: Electroplating is performed using the plating solution according to any one of claims 6 to 8; providing a substrate having a surface to be electroplated; contacting the substrate with the plating solution; applying an electric current between the substrate and the anode for electroplating; Optionally, the current density is 0.2A / dm 2 -40A / dm 2 ; Optionally, the temperature of the plating solution is 10°C-50°C.

10. A coating, characterized in that: The coating is obtained by electroplating the plating solution according to any one of claims 6 to 8 on the surface of the substrate; or by electroplating the plating process according to claim 9.

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