Copper electroplating leveling agent, preparation method, electroplating liquid and application

Abstract

The invention relates to the technical field of electroplating, in particular to a copper electroplating leveling agent, a preparation method, electroplating liquid and application. The raw materials comprise cyclic amine, five-membered heteroaromatic hydrocarbon and an epoxy compound; the molar ratio of the cyclic amine to the five-membered heteroaromatic hydrocarbon to the epoxy compound is 1: (0.8-1.2): (0.1-10). The copper electroplating leveling agent disclosed by the invention can be added into an electroplating solution system to play an excellent hole filling effect, and when a blind hole is electroplated, the surface copper thickness is less than 15 microns; and the method can meet the processing and fine development requirements of electronic devices.

Description

Technical Field

[0001] The invention relates to the technical field of electroplating, and in particular to an electroplating copper leveler and a preparation method, an electroplating solution and applications. Background Art

[0002] With the development of electronic information technology, electronic products and equipment tend to be thinner, smaller and more integrated. As a carrier of electronic components, circuit board design and manufacturing are also developing rapidly in the direction of high-density interconnection and small-hole technology, thus HDI (high-density interconnection) boards and IC (integrated circuit) boards came into being. In order to meet the requirements of high density and high integration, blind hole electroplating filling technology has gradually become one of the important research topics in the industry. Blind hole filling can not only achieve the welding of blind holes in pads, but also adopt the method of stacking holes up and down to replace the through holes between some or all layers, which is responsible for electrical transmission while improving the heat dissipation of products. The blind hole filling process requires that after the hole filling electroplating, the blind hole needs to be completely filled with the copper layer, the depression value (Dimple value) is as small as possible, and there are no defects such as core, void or crack in the hole; reduce the loss of transmission signals, thereby ensuring the reliability and stability of electronic products.

[0003] In order to ensure the electrical performance between multilayer boards, a sulfate copper plating system is generally used. The process is simple, the composition of the plating solution is simple, the components are cheap, and the formed plating solution is stable and easy to control. The copper plating effect is affected by additives such as accelerators, wetting agents and levelers. Among them, the leveler is a crucial raw material in the copper plating additive system. It can be adsorbed in areas with high cathode current density and compete with copper ions, making it difficult for copper ions to deposit at high potentials but not affecting copper deposition in low current areas, thereby avoiding the void phenomenon caused by premature sealing during the hole filling process. However, the blind hole filling copper plating levelers currently available on the market have low electroplating efficiency for blind holes on the one hand; on the other hand, the process or raw material preparation is complicated and has poor practicality; on the other hand, the surface copper obtained by electroplating is relatively thick, which increases the difficulty of subsequent etching and is not conducive to the production of fine lines.

[0004] Chinese patent CN117966225B discloses a QFP crude copper electroplating solution, preparation method and electroplating method. The electroplating solution is configured by copper salt, conductive salt, brightener, first stabilizer, quaternary ammonium salt, additives, etc., to solve the technical problems of weak surface bonding and cracking defects of semiconductor integrated circuit products, which leads to unstable signal transmission and excessive power loss of semiconductor chip products. Chinese patent CN117107310A discloses a hole filling leveling agent and its preparation method, electroplating copper solution, and electroplating copper method. A tertiary amine polymer or its quaternized copolymer is formed by polymerizing nitrogen-containing heterocyclic compounds and polyol glycidyl ether substances to effectively reduce the deposition of copper ions. However, none of these prior arts solves the above technical problems at the same time. Summary of the invention

[0005] In view of this, the present invention discloses an electroplating copper leveler and a preparation method thereof and an application thereof in blind hole filling electroplating to solve the problems existing in the above-mentioned background technology. The electroplating copper leveler has a strong burst capacity and can fill the blind hole in a relatively short hole filling time, so that the electroplating solution has excellent hole filling performance, and at the same time greatly reduces the copper thickness of the blind hole filling surface, which can effectively reduce the difficulty of circuit etching and process production cost.

[0006] The first aspect of the present invention provides a copper electroplating leveler, the raw materials of which include: cyclic amine, five-membered heteroaromatic hydrocarbon, and epoxy compound.

[0007] Preferably, the five-membered heteroaromatic compound has a structure shown in Formula 1:

[0008]

[0009] In Formula 1, X and Y are independently selected from C, N, S or O atoms; and X and Y are not C atoms at the same time.

[0010] In formula 1, R 1 , R 2 Independently selected from any one of a hydrogen atom, a linear or branched C1-C10 alkyl group, a linear, branched or cyclic C1-C10 heterocycloalkyl group, an aromatic hydrocarbon group, and a heteroaromatic hydrocarbon group.

[0011] Preferably, R 1 , R 2 It can be used as a constituent unit of cycloalkanes.

[0012] More preferably, the cyclic alkane may be a heterocyclic alkane.

[0013] More preferably, the cyclic alkane may be any one of a linear cyclic alkane or a branched cyclic alkane. 1 , R 2 It can form straight-chain or branched cyclic alkanes and heterocyclic alkanes together with other atoms.

[0014] Preferably, the five-membered heteroaromatic compound is selected from at least one of pyrrole, thiazole, oxazole and imidazole compounds.

[0015] Preferably, the epoxy compound is at least one of monofunctional glycidyl ether (Formula 2), difunctional glycidyl ether (Formula 2, Formula 3, Formula 4, Formula 5 or Formula 6), and polyfunctional glycidyl ether.

[0016]

[0017] Examples of the compound of Formula 2 include benzyl monoglycidyl ether, butyl glycidyl ether, octyl glycidyl ether, dodecyl glycidyl ether, and allyl glycidyl ether.

[0018] Examples of the compound of Formula 3 include diethylene glycol diglycidyl ether and the like.

[0019] Examples of the compound of Formula 4 include ethylene glycol diglycidyl ether, polyethylene glycol glycidyl ether, polypropylene glycol glycidyl ether, 1,4-butanediol glycidyl ether, 1,6-hexanediol diglycidyl ether, and the like.

[0020] As an example of Formula 5, 1,4-cyclohexanedimethanol diglycidyl ether can be cited.

[0021] As an example of Formula 6, neopentyl glycol diglycidyl ether can be cited.

[0022] Examples of the polyfunctional glycidyl ether include glycerol triglycidyl ether and the like.

[0023] The raw materials of the copper electroplating leveler also include a solvent, and the solvent is a commonly used solvent in the art that can achieve the purpose of dissolution, such as water.

[0024] Preferably, the cyclic amine compound may be at least one of a four-membered cyclic amine, a five-membered cyclic amine, and a six-membered cyclic amine.

[0025] More preferably, the cyclic amine includes at least one of tetrahydropyrrole, piperidine and piperazine; and most preferably tetrahydropyrrole.

[0026] Preferably, the molar ratio of the cyclic amine, the five-membered heteroaromatic hydrocarbon, and the epoxy compound is 1:(0.8-1.2):(0.1-10).

[0027] Preferably, the molar ratio of the cyclic amine, the five-membered heteroaromatic hydrocarbon, and the epoxy compound is 1:(0.9-1.1):(0.15-5).

[0028] The electroplating copper leveler of the present invention can be added to the electroplating solution system as a leveler. When the blind hole is electroplated, it can cooperate with the brightener and the inhibitor to obtain a bright, flat copper deposit layer with excellent physical properties. When applied to blind hole electroplating, the electroplating time can be shortened, the production capacity can be increased, and the hole filling performance is excellent. The copper thickness after electroplating is less than 15 μm, which can significantly reduce the amount of copper used, thereby saving costs, and further can adapt to the development requirements of the MSAP (modified semi-additive process) process and packaging carrier.

[0029] The second aspect of the present invention provides a method for preparing the above-mentioned electroplating copper leveler, the preparation steps comprising: mixing a cyclic amine, a five-membered heteroaromatic hydrocarbon, and an epoxy compound in a solvent, and reacting at 50-100° C. for 2-12 hours to obtain the electroplating copper leveler. The preparation method of the electroplating copper leveler of the present invention is simple, easy to operate, and is conducive to industrial mass production.

[0030] Preferably, the reaction conditions of the electroplating copper leveler are 55-70° C. for 4-8 hours.

[0031] The weight average molecular weight of the electroplating copper leveler is 200 to 20,000, preferably 500 to 5,000.

[0032] Preferably, the pH value of the electroplating copper leveler is 1.0-3.0.

[0033] The reaction temperature needs to be monitored when preparing the leveling agent in the present invention. When the reaction is too fast, the reaction temperature rises quickly, and the heat is difficult to be transferred out of the system in time, which easily leads to side reactions and even gelation. Therefore, the dripping speed and reaction temperature need to be strictly controlled.

[0034] In some embodiments, the progress of the reaction can be monitored by TLC (spot plate), infrared, or ultraviolet means.

[0035] Preferably, a syringe pump is used to add materials during the preparation process, so that the adding speed can be controlled more accurately.

[0036] The third aspect of the present invention provides an electroplating solution, the raw materials of which include: 20-150 g / L sulfuric acid, 100-260 g / L copper sulfate pentahydrate, 30-100 ppm chloride ions, 0.5-20 ppm accelerator, 50-7000 ppm inhibitor and 1-400 ppm leveler (i.e., the copper electroplating leveler obtained by reacting the above-mentioned cyclic amine, five-membered heteroaromatic hydrocarbon and glycidyl ether).

[0037] Further preferably, the raw materials include: 40-120 g / L sulfuric acid, 120-240 g / L copper sulfate pentahydrate, 40-80 ppm chloride ions, 1-10 ppm accelerator, 60-6000 ppm inhibitor and 10-100 ppm of the above-mentioned electroplating copper leveler (i.e., the product obtained by the reaction of the above-mentioned cyclic amine, five-membered heteroaromatic hydrocarbon and epoxy compound).

[0038] The accelerator is a commonly used accelerator in the art, such as sodium polydisulfide propane sulfonate (SPS).

[0039] The inhibitor is a commonly used inhibitor in the art, such as polyethylene glycol (PEG 8000, etc.).

[0040] Preferably, when the plate is electroplated using the electroplating solution, the plate is pre-treated.

[0041] The pre-treatment can be carried out by using a common pre-treatment process in the art, such as pickling, degreasing, micro-etching, etc. After the pre-treatment process, the electroplating process is entered, and the electroplating effect is better.

[0042] The third aspect of the present invention provides the application of the above-mentioned electroplating solution, which can be used for processing electronic components such as PCB (circuit board) and IC (integrated circuit).

[0043] The fourth aspect of the present invention provides a method for using the above-mentioned electroplating solution, wherein the electroplating conditions of the electroplating solution are: a current density of 0.5-5.0A / dm 2 , the electroplating temperature is 5-50℃, and the electroplating time is 15-80min.

[0044] Preferably, the electroplating conditions of the electroplating solution are: the current density is 1.0-3.0A / dm 2 , the electroplating temperature is 10-40℃, and the electroplating time is 30-60min.

[0045] Beneficial effects:

[0046] The present invention provides a copper electroplating leveling agent and a preparation method and application thereof, which have the following advantages:

[0047] (1) The copper electroplating leveler of the present invention can be added to the electroplating solution system to exert an excellent hole-filling effect. When the blind hole is electroplated, the surface copper thickness is less than 15 μm; it can meet the development needs of refined processing of electronic devices.

[0048] (2) The present invention preferably uses a five-membered heteroaromatic hydrocarbon with a specific structure, which can react with a cyclic amine and an epoxy compound to generate a leveling agent with high electroplating activity. The leveling agent is more easily adsorbed on the surface of the workpiece where the current density is high, that is, where the negative polarity is strong, and competes with copper ions, making it difficult for copper atoms to settle at high current locations, but it does not affect the copper plating in low current areas, so that the originally uneven surface of the workpiece becomes flatter.

[0049] (3) After the leveling agent of the present invention is applied to the electroplating solution, it not only reduces the surface copper thickness, but also can control the plating depression within 5 μm, and there are no plating voids, cracks and other poor quality in the filled blind holes, which can take into account both low cost and high quality of the manufactured parts.

[0050] (4) The raw materials of the copper electroplating leveler of the present invention are easily available, the preparation method is simple, and the operation is convenient. Moreover, the product does not need further purification and can be directly applied to electroplating experiments, which is conducive to industrial mass production.

[0051] (5) The copper electroplating leveler and electroplating solution of the present invention have a wide range of applications and can be used in the processing of various electronic components such as PCB (circuit board) and IC (integrated circuit), significantly improving the blind hole filling effect and ensuring the reliability and stability of electronic products. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] Figure 1 This is a diagram showing the hole filling effect of the leveling agent 1 applied to the electroplating solution;

[0053] Figure 2 This is a diagram showing the hole filling effect of Example 2 applied to the electroplating solution;

[0054] Figure 3 This is a diagram showing the hole filling effect of Example 3 applied to the electroplating solution. DETAILED DESCRIPTION

[0055] Note: The raw materials involved in the present invention can be purchased through conventional commercial channels, such as Shanghai MacLean Biochemical Technology Co., Ltd., Shanghai BiDe Pharmaceutical Technology Co., Ltd., etc.

[0056] Note: Unless otherwise specified, the solvent of the solution referred to in the present invention is water.

[0057] Example 1.

[0058] The invention discloses an electroplating copper leveler, wherein the raw materials are composed of cyclic amine (tetrahydropyrrole), five-membered heteroaromatic hydrocarbon (thiazole), epoxy compound (1,4-butanediol glycidyl ether) and deionized water.

[0059] The preparation method of the electroplated copper leveler includes: adding 1.67g of thiazole, 1.5g of tetrahydropyrrole, and 25mL of deionized water into a 100mL three-necked round-bottom flask; controlling the temperature of the water bath to 80°C, adding 10g of 1,4-butanediol glycidyl ether through an injection pump, and controlling the addition to be completed within 10min, and controlling the temperature not to exceed 85°C during the addition process (achieved by adjusting the addition speed). After the addition is completed, the temperature is raised to 90°C and reacted for 6 hours, and then cooled to room temperature (25°C). Add 50% sulfuric acid aqueous solution to adjust the pH of the electroplated copper leveler to 3, add deionized water to make the volume 50g, and obtain leveler 1.

[0060] Example 2.

[0061] The invention discloses an electroplating copper leveler, wherein the raw materials are composed of cyclic amine (tetrahydropyrrole), five-membered heteroaromatic hydrocarbon (4-thiazole), epoxy compound (1,4-butanediol glycidyl ether) and deionized water.

[0062] The preparation method of the electroplated copper leveler includes: adding 2.02g of 4-methylthiazole, 1.5g of tetrahydropyrrole, and 25mL of deionized water into a 100mL three-necked round-bottom flask; controlling the temperature of the water bath to 80°C, adding 10g of 1,4-butanediol glycidyl ether through an injection pump, and controlling the addition to be completed within 10min, and controlling the temperature not to exceed 85°C during the addition process (achieved by adjusting the addition speed). After the addition is completed, the temperature is raised to 90°C and reacted for 6 hours, and then cooled to room temperature (25°C). Add 50% sulfuric acid aqueous solution to adjust the pH of the electroplated copper leveler to 3, add deionized water to make the volume 50g, and obtain leveler 2.

[0063] Example 3.

[0064] The invention discloses an electroplating copper leveler, wherein the raw materials are composed of cyclic amine (tetrahydropyrrole), five-membered heteroaromatic hydrocarbon (4-phenylthiazole), epoxy compound (1,4-butanediol glycidyl ether) and deionized water.

[0065] The preparation method of the electroplated copper leveler includes: adding 3.55g of 4-phenylthiazole, 1.5g of tetrahydropyrrole, and 25mL of deionized water into a 100mL three-necked round-bottom flask; controlling the temperature of the water bath to 80°C, adding 10g of 1,4-butanediol glycidyl ether through an injection pump, and controlling the addition to be completed within 10min, and controlling the temperature not to exceed 85°C during the addition process (achieved by adjusting the addition speed). After the addition is completed, the temperature is raised to 90°C and reacted for 6 hours, and then cooled to room temperature (25°C). Add 50% sulfuric acid aqueous solution to adjust the pH of the electroplated copper leveler to 3, add deionized water to make the volume 50g, and obtain leveler 3.

[0066] Application examples:

[0067] The leveling agent 1, leveling agent 2 and leveling agent 3 are respectively configured into electroplating solution 1, electroplating solution 2 and electroplating solution 3 according to the following schemes.

[0068] The formula and configuration method of the plating solution are as follows:

[0069] (1) Prepare the basic solution: The basic solution is composed of 240 g / L copper sulfate pentahydrate, 40 g / L sulfuric acid, 60 ppm chloride ions (chloride ions are derived from hydrochloric acid), and the solvent is water;

[0070] (2) Take 1.5 L of the basic solution, add 2 ppm of the accelerator sodium polydisulfide dipropane sulfonate, 400 ppm of the inhibitor PEG 8000, and then add 30 ppm of the leveler, stir evenly, and obtain an electroplating solution.

[0071] Note: 2ppm of accelerator sodium polydisulfide dipropane sulfonate, 400ppm of inhibitor PEG 8000 and 30ppm of leveler refer to the final concentration after being added to the base solution; the amount to be added can be determined by calculation based on the concentration requirements.

[0072] How to use the plating solution:

[0073] In a 1.5L Haring tank filled with electroplating solution and a soluble anode (copper), a HDI (high density interconnect) double-sided four-layer blind hole board with a thickness of 1mm and a blind hole diameter of 120μm×85μm was placed for electroplating. The electroplating conditions were: DC 1.3ASD electroplating for 60min, and the electroplating temperature was 25℃.

[0074] The HDI double-sided four-layer blind hole board is pre-treated before electroplating, specifically pickling with 10% sulfuric acid for 2 minutes, degreasing with 10% aqueous solution of SCC-E-342D degreasing agent produced by our company for 2 minutes, and micro-etching with sulfuric acid / sodium persulfate aqueous solution for 2 minutes.

[0075] Performance Testing

[0076] The copper thickness of the plated board, the Dimple value of the filled hole, and the voids in the filled hole were observed and measured using a microscope. The test results are shown in Table 1 and Figure 1-3 From Table 1 and Figure 1-3 It can be seen that the leveling agent synthesized by the specific cyclic amine, five-membered heteroaromatic ring and epoxy compound of the present invention has excellent hole filling performance, can significantly reduce the surface copper thickness to less than 15μm, and can obtain a depression within 5μm. Using the electroplating solution formula of the present invention, there is no plating void, cracks and other poor quality in the filled blind hole.

[0077] Table 1

[0078]

Claims

1. A copper electroplating leveler, characterized in that: Raw materials include: cyclic amines, five-membered heteroaromatic hydrocarbons, and epoxy compounds; The molar ratio of the cyclic amine, the five-membered heteroaromatic hydrocarbon and the epoxy compound is 1:(0.8-1.2):(0.1-10).

2. The copper electroplating leveler according to claim 1, characterized in that: The five-membered heteroaromatic compound has a structure shown in Formula 1: In Formula 1, X and Y are independently selected from C, N, S or O atoms; and X and Y are not C atoms at the same time.

3. The copper electroplating leveler according to claim 2, characterized in that: In formula 1, R 1 , R 2 Independently selected from any one of a hydrogen atom, a linear or branched C1-C10 alkyl group, a linear, branched or cyclic C1-C10 heterocycloalkyl group, an aromatic hydrocarbon group, and a heteroaromatic hydrocarbon group.

4. The copper electroplating leveler according to claim 1, characterized in that: The five-membered heteroaromatic compound is selected from at least one of pyrrole, thiazole, oxazole and imidazole compounds.

5. The copper electroplating leveler according to claim 1, characterized in that: The epoxy compound is a combination of one or more of monofunctional glycidyl ether, difunctional glycidyl ether and polyfunctional glycidyl ether; Preferably, the epoxy compound contains a structure represented by Formula 2, Formula 3, Formula 4, Formula 5 or Formula 6.

6. A method for preparing the copper electroplating leveler according to claim 1, characterized in that: The preparation steps include: mixing cyclic amine, five-membered heteroaromatic hydrocarbon and epoxy compound in a solvent, and reacting at 50-100° C. for 2-12 hours to obtain the product.

7. The copper electroplating leveler according to claim 6, characterized in that: The electroplating copper leveler is adjusted to a pH of 1-3 before use.

8. An electroplating solution, characterized in that The raw materials include: 20-150 g / L sulfuric acid, 100-260 g / L copper sulfate pentahydrate, 30-100 ppm chloride ion, 0.5-200 ppm accelerator, 50-7000 ppm inhibitor and 1-400 ppm of the electroplating copper leveler according to any one of claims 1-5.

9. Use of the electroplating solution according to claim 8 in PCB and IC parts processing.

10. A method for using the electroplating solution according to claim 8, characterized in that: The electroplating conditions of the electroplating solution are: current density 0.5-5.0A / dm 2 , the electroplating temperature is 5-50℃, and the electroplating time is 15-80min.

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