Leveling agent capable of being used for hole filling and copper plating process of micro blind hole with high thickness-diameter ratio and electroplating solution

Abstract

The invention relates to the technical field of electroplating (IPC classification number: C25D), in particular to a leveling agent for a hole filling and copper plating process of a micro blind hole with a high thickness-diameter ratio, an electroplating solution and a copper plating process. The leveling agent is a polymerization product of linear amine and polyol glycidyl ether; preferably, the straight-chain amine is compounded by primary diamine and unsaturated straight-chain monoamine. Primary diamine, propargylamine and polyol glycidyl ether are polymerized to obtain the leveling agent with a specific molecular structure, and the obtained leveling agent is especially suitable for filling micro blind holes; in the blind hole filling process, electroplating is uniform, and the surface of a carrier plate material is bright and free of cracks, cavities and other defects when thin-surface copper is plated. When the leveling agent is added into an electroplating solution system and hole filling electroplating is carried out on blind holes with the thickness-diameter ratio of 0.2-1.7, the recession degree of the blind holes is smaller than 5 micrometers, the filling rate is larger than 95%, the surface of a carrier plate is bright, pinholes and hard spots do not exist, and the leveling agent can adapt to different carrier plate materials and process requirements and is wide in application prospect.

Description

Technical Field

[0001] The present invention relates to the field of electroplating technology (IPC classification number: C25D), and in particular to a leveling agent and electroplating solution and a copper plating process which can be used for a high aspect ratio micro blind hole filling copper plating process. Background Art

[0002] With the continuous development of electronic products, blind hole filling products and processes have also developed rapidly, and the high aspect ratio blind hole filling technology of substrates has received more and more attention. However, in the process of filling micro blind holes with high aspect ratios, some problems often occur, such as core wrapping and uneven surface copper thickness. These problems seriously affect the filling effect and the quality of electroplating leveling. The current hole filling and leveling agents often cannot meet the special requirements of high aspect ratio blind holes, and cannot fully fill and level the microholes, resulting in incomplete hole filling and poor filling effect of small hole diameters. There are also some other problems with the current hole filling technology, such as the difficulty of processing the hole filling agent, slow filling speed, and poor filling effect. In addition, the cost of the hole filling and leveling agent is high, which is not conducive to large-scale application.

[0003] Under such background, how to improve the filling speed, filling effect and leveling effect of the hole filling and leveling agent and reduce the production cost is an urgent problem to be solved in the current electroplating field. Chinese patent CN117107310A discloses a hole filling and leveling agent, in which nitrogen-containing heterocyclic compounds and polyol glycidyl ethers are polymerized to obtain the leveling agent. CN117587472A discloses an electroplating solution for through-blind hole co-plating and its application and a method for through-blind hole co-plating of HDI board, and the leveling agent is selected as a nitrogen-containing organic substance such as dipropylamine acetate. However, these prior arts still cannot obtain a good hole filling effect when used for filling micro blind holes.

[0004] Based on this, there is an urgent need to develop an electroplating leveler for filling micro blind vias with high aspect ratios, which can effectively improve the filling effect and uniformity of surface copper thickness at low cost and solve the problems existing in the current filling process. Summary of the invention

[0005] In order to overcome the problems of existing blind hole filling, especially the defect that the hole filling leveling agent cannot meet the special requirements of high aspect ratio blind holes, the key of the present invention is to effectively improve the hole filling effect of high aperture ratio blind holes through special molecular structure design. Through the reasonable and specific design of the molecular structure of the leveling agent, the hole filling ability and filling depth of the leveling agent can be improved, thereby reducing or eliminating the problems of core sheath and surface copper thickness in high aperture ratio blind holes, and effectively improving the hole filling performance of high aspect ratio micro blind holes. Furthermore, adding other additive components to the electroplating solution can improve the stability of the leveling agent, thereby ensuring the stability and reliability of electroplating hole filling. Through the technical solution of the present invention, the development and application of high aperture ratio blind hole filling electroplating leveling agents can be realized, which meets the technical requirements of electronic products for high aspect ratio blind hole filling technology of carriers, and improves the filling effect of carriers and device quality.

[0006] In view of the problems existing in the prior art, the first aspect of the present invention provides a leveler that can be used in a high aspect ratio micro blind hole filling copper plating process, wherein the leveler is a polymerization product of a linear amine and a polyol glycidyl ether.

[0007] In some preferred embodiments, the linear amine is a primary diamine and / or an unsaturated linear amine; preferably, the linear amine is a composite of a primary diamine and an unsaturated linear monoamine.

[0008] In some preferred embodiments, the molar ratio of the primary diamine, the unsaturated linear monoamine and the polyol glycidyl ether is 1:(0.4-1.2):(0.1-5).

[0009] In some preferred embodiments, the primary diamine is an alkyl primary diamine or a heteroatom-containing primary diamine.

[0010] In some preferred embodiments, the primary diamine has the structural formula shown in (1), (2) or (3):

[0011]

[0012] Wherein, n is 0-16; and n≠1.

[0013] Preferably, n is 0-14, and n≠1; n can be listed as 0, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13 or 14.

[0014] In some preferred embodiments, the primary diamine compound is selected from at least one of hydrazine hydrate, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, 1,4-pentanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, adipic acid diamine, N-methyl-2,2`-diaminodiethylamine, and 2-methyl-1,3-propylenediamine.

[0015] Preferably, the primary diamine compound may also be selected from o-phenylenediamine or p-phenylenediamine.

[0016] In some embodiments, other amine compounds may be used to replace the primary diamine according to usage requirements, such as N-ethyl-1,3-propylenediamine, N-propyl-1,3-propylenediamine, N-benzyl-1,3-propylenediamine, and N-acetyl-1,3-propylenediamine.

[0017] In some preferred embodiments, the unsaturated linear amine is propargylamine.

[0018] Preferably, the polyol glycidyl ether material is selected from at least one of trimethylolpropane triglycidyl ether, polypropylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, resorcinol diglycidyl ether, 1,2-cyclohexanediol diglycidyl ether, 1,4-cyclohexanedimethanol diglycidyl ether, dipropylene glycol diglycidyl ether, triethylene glycol diglycidyl ether, propoxyglycerol triglycidyl ether, and sorbitol glycidyl ether. Further preferably, the polyol glycidyl ether material is trimethylolpropane triglycidyl ether.

[0019] The present invention is prepared by polymerizing primary diamine, propargylamine and polyol glycidyl ether. The hole filling and leveling agent obtained by polymerizing specific monomers can be well used for micro blind hole electroplating, and is more conducive to its deposition inhibition at the convex part of the microscopic surface, so that the copper deposition rate at the concave part of the carrier is higher than the deposition rate at the convex part. The blind holes with different thickness-to-diameter ratios of the carrier can be well filled and leveled when the coating thickness is thin. There is no hollow in the blind hole, and the depression is less than 5 microns. Further, the present invention preferably has a molar ratio of primary diamine, unsaturated linear monoamine and polyol glycidyl ether of 1: (0.4-1.2): (0.1-5). By controlling the molar amount of the monomers, the leveling agent is given appropriate polarity and formula compatibility. The obtained leveling agent also has good dispersibility, and can effectively improve the conductivity, thermal performance and reliability of the carrier when applied to electroplating.

[0020] The second aspect of the present invention provides a method for preparing a leveling agent, comprising: subjecting a linear amine and a polyol glycidyl ether to a polymerization reaction under heating conditions to obtain the leveling agent; and controlling the heating temperature to be above 30°C.

[0021] Preferably, the reaction temperature is 5-95°C and the reaction time is 2-18h; more preferably, the reaction temperature is 30-45°C and the reaction time is 2-15h.

[0022] In some preferred embodiments, the polyol glycidyl ether is cooled to below 5°C before participating in the reaction (the initial reaction of the linear amine and the polyol glycidyl ether will release a large amount of heat. If not pretreated, the reaction temperature will be too high, affecting the performance of the synthetic leveler).

[0023] Preferably, the molecular weight of the leveling agent is 500-20000, preferably 800-5000.

[0024] The third aspect of the present invention provides an electroplating solution, the components of the electroplating solution include: 10-120 mg / L of chloride ions, 20-150 g / L of acidic electrolyte, 170-300 g / L of copper ion salt, 1-160 g / L of iron ion salt, 0.1-10 mg / L of brightener, 5-12000 mg / L of inhibitor, 5-6000 mg / L of the above-mentioned leveling agent, and the solvent of the electroplating solution is deionized water;

[0025] Preferably, the components of the electroplating solution include: 190-270 g / L of copper ion salt, 30-120 g / L of acidic electrolyte, 20-100 mg / L of chloride ion, 2-120 g / L of iron ion salt, 0.5-6 mg / L of brightener, 10-10000 mg / L of inhibitor, 10-5000 mg / L of leveling agent according to any one of claims 1-7, and the solvent is deionized water.

[0026] In some embodiments, the basic component range and process conditions of the electroplating solution are as shown in Table 1; the standard values ​​in Table 1 are the added values ​​in the TDS line opening operation instructions, which are the optimal parameters for the hole filling effect during electroplating.

[0027] Table 1

[0028] Components or process conditions scope Standard value Copper sulfate pentahydrate 190~270g / L 250g / L sulfuric acid 30~120g / L 35g / L Chloride ion 20~100mg / L 60ppm Ferrous sulfate heptahydrate 2~120g / L 6g / L Brightener 0.5~6mg / L 2.2ppm Inhibitors 10~10000mg / L 400ppm Leveling agent 10~5000mg / L 120ppm anode Insoluble Anode Iridium-Tantalum coated titanium anode Current density 1~35ASF 5~25ASF temperature 20～35℃ 22～27℃

[0029] The copper ion salt is not particularly limited in the present application, and those skilled in the art can make a conventional selection according to needs, for example, copper sulfate pentahydrate.

[0030] In some preferred embodiments, the iron ion salt is an acidic iron salt; further preferably, the iron ion salt is selected from ferric sulfate or ferric chloride.

[0031] In some preferred embodiments, the ferrous salt is an acidic ferrous salt; further preferably, the ferrous salt is selected from one or more of ferrous sulfate (e.g., ferrous sulfate heptahydrate, anhydrous ferrous sulfate), ferrous carbonate, ferrous chloride, ferrous phosphate, and ferrous oxalate; more preferably, the ferrous salt is ferrous sulfate.

[0032] The acidic electrolyte in the present application is not particularly limited, and those skilled in the art may make a conventional selection according to needs, for example, hydrochloric acid, sulfuric acid or a combination thereof.

[0033] The present application does not particularly limit the types of inhibitors, and those skilled in the art can make routine selections based on their needs.

[0034] In some preferred embodiments, the weight average molecular weight of the inhibitor is 400-20,000.

[0035] Preferably, the inhibitor is selected from one or more of PEG1500, PEG20000, 50HB-400, and PEG10000.

[0036] In some preferred embodiments, the brightener is sodium 3-mercaptopropane sulfonate and sodium polydipropane disulfide sulfonate; preferably, the mass concentration ratio of sodium 3-mercaptopropane sulfonate to sodium polydipropane disulfide sulfonate is 0.01-0.5:1; more preferably 0.02-0.2:1.

[0037] The fourth aspect of the present invention provides a micro blind hole copper plating process, the micro blind hole copper plating process comprising: placing the above-mentioned electroplating solution on a printed circuit board having a plurality of micro blind holes for copper plating; after the copper plating is completed, the depression of the micro blind hole plating layer is less than 5μm, and the filling rate is greater than 95%

[0038] In some preferred embodiments, the electroplating time in the copper plating process is 20-180 min; preferably, the electroplating time in the copper plating process is 30-120 min.

[0039] In some preferred embodiments, the electroplating temperature in the copper plating process is 20-30°C, preferably 22-27°C.

[0040] In some preferred embodiments, the current density of the DC power supply in the copper plating process is 1-35 ASF, and more preferably 5-25 ASF.

[0041] In some preferred embodiments, the micro blind hole copper plating process further includes: adding an adapted insoluble anode to the electroplating solution, adding ferrous salt to the electroplating solution (first mixing the raw materials except the iron ion salt), so that the ferrous ions are oxidized into trivalent ferrous ions on the surface of the insoluble anode; returning the plating solution containing trivalent ferrous ions to the pure copper blocks or pure copper particles in the copper dissolving tank, accelerating the electrolysis of metallic copper through the oxidation of trivalent ferrous ions, converting metallic copper into divalent cupric ions, and reducing the trivalent ferrous ions to divalent ferrous ions, and replenishing the copper ions consumed in the electroplating process through reciprocating cycles.

[0042] From the above conception, it can be seen that the design premise of the copper plating process of the present invention is to select an iron-containing acidic system for the electroplating solution, and on this basis, cooperate with the preferred leveling agent to cycle back and forth during the micro blind hole electroplating process, and replenish the copper ions consumed in the electroplating process while electroplating to fill the holes. While improving the quality of the coating, it can also greatly improve the production efficiency, which is conducive to large-scale mass production and cost reduction and efficiency improvement.

[0043] The present application does not impose any particular restrictions on the manner in which the electroplating solution is placed on a printed circuit board having micro blind vias, the type of printed circuit board, and the specifications of the printed circuit board. Technical means that can achieve the process objectives in the art may be used.

[0044] In some preferred embodiments, the micro blind hole depth of the printed circuit board is 20-90 μm, the blind hole diameter is 20-150 μm, and the thickness-diameter ratio of the micro blind hole is between 0.2 and 1.8. After investigation, it was found that the electroplating solution of the present invention combined with a specific copper plating process can be applied to the above-mentioned specifications of blind holes, and the blind holes can be filled after electroplating, and the electroplating effect is excellent. The concavity of the blind holes after electroplating is less than 5 μm.

[0045] At present, the traditional copper plating process adopts phosphor copper anode copper plating, which will produce anode sludge; the insoluble anode adopts copper oxide powder copper filling process, which will introduce a large amount of impurities into the plating solution, and it is impossible to make the system absolutely pure. When copper plating, the board surface will inevitably have poor appearance, such as dents, burrs, pits, pinholes and other electroplating defects. Through the leveling agent, electroplating solution and matching copper plating process method of the present invention, it is possible to improve the hole filling performance of the electroplating leveling agent, and it is also possible to adjust the acid copper content of the electroplating solution and stabilize the electroplating performance to adapt to different substrate materials and new hole filling process requirements. In addition, the preparation method of the electroplating leveling agent provided by the present invention is simple and easy, suitable for industrial production, and has high economic benefits and application prospects.

[0046] Beneficial effects:

[0047] The present invention provides a leveling agent, an electroplating solution and a copper plating process that can be used for a high aspect ratio micro blind hole filling copper plating process, which has the following beneficial effects compared with the prior art:

[0048] (1) The present invention uses primary diamine, propargylamine and polyol glycidyl ether to polymerize to obtain a leveling agent with a specific molecular structure. The obtained leveling agent is particularly suitable for filling micro blind holes. It ensures that the electroplating is uniform during the blind hole filling process, and when a relatively thin copper is plated, the surface of the substrate material is bright without defects such as gaps and voids.

[0049] (2) The preferred molar ratio of the primary diamine, the unsaturated linear monoamine and the polyol glycidyl ether is 1:(0.4-1.2):(0.1-5) in the present invention, which gives the leveling agent suitable polarity and formulation compatibility, so that the obtained leveling agent can effectively improve the conductivity, thermal properties and reliability of the substrate when used in electroplating;

[0050] (3) The electroplating solution of the present invention can electroplate blind holes of different aperture sizes on UHDI substrates and various PCB substrates by using a specific leveling agent and preferred inhibitors, brighteners and other components together with a suitable electroplating copper process, thereby solving the technical problem that it is difficult to fill the blind holes of UHDI substrates and various PCB substrates when the coating thickness is thin, and can effectively solve the core and surface copper thickness problems in the process of filling micro blind holes with high aspect ratios, thereby improving the electrical performance and appearance quality of the product;

[0051] (4) The preparation method of the electroplating leveling agent provided by the present invention is simple and easy to implement, suitable for industrial production, and has high economic benefits and application prospects;

[0052] (5) The copper plating process of the present invention is based on the premise that the electroplating solution is an iron-containing acidic system. On this basis, it cooperates with the preferred leveling agent to cycle back and forth during the micro-blind hole electroplating process, and the copper ions consumed in the electroplating process are replenished while the electroplating holes are filled, which greatly improves the production efficiency and is conducive to large-scale mass production.

[0053] (6) The electroplating solution containing the leveling agent of the present invention can not only meet the requirements of various types and specifications of substrates, but is also particularly suitable for filling micro blind holes with a high aspect ratio. After electroplating, the blind holes can be filled. When the blind holes with an aspect ratio of 0.2 to 1.7 are electroplated, the dimple of the blind holes is less than 5 μm and the filling rate is greater than 95%. It can meet the increasingly stringent requirements for refinement.

[0054] (7) Through the leveling agent, electroplating solution and copper plating process provided by the present invention, high aperture ratio blind hole filling can be achieved, meeting the requirements of electronic products for high aspect ratio blind hole filling technology of carrier boards, and improving the filling effect of the carrier board and the product quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 : Schematic diagram of the cross section of a blind hole, where H1 is the distance from the bottom of the blind hole to the upper copper layer, H2 is the total thickness of the dielectric layer and the copper layer, and H3 is the thickness of the copper plating layer (excluding the bottom copper);

[0056] Figure 2 : A cross-sectional view of a blind hole with a thickness-to-diameter ratio of 0.5 after via-filling electroplating using the leveling agent and the electroplating solution of Example 1 of the present invention;

[0057] Figure 3: A cross-sectional view of a blind hole with a thickness-to-diameter ratio of 0.38 after via-filling electroplating using the leveling agent and plating solution of Example 1 of the present invention;

[0058] Figure 4 : A cross-sectional view of a blind hole with a thickness-to-diameter ratio of 0.31 after via-filling electroplating using the leveling agent and the electroplating solution of Example 1 of the present invention;

[0059] Figure 5 : A cross-sectional view of a blind hole with a thickness-to-diameter ratio of 0.25 after via-filling electroplating using the leveling agent and plating solution of Example 1 of the present invention;

[0060] Figure 6 : A cross-sectional view of a blind hole with a thickness-to-diameter ratio of 0.2 after via-filling electroplating using the leveling agent and the electroplating solution of Example 1 of the present invention;

[0061] Figure 7 : A cross-sectional view of a blind hole with a thickness-to-diameter ratio of 1.7 after via-filling electroplating using the leveling agent and plating solution of Example 1 of the present invention;

[0062] Figure 8 : A cross-sectional view of a blind hole with a thickness-to-diameter ratio of 1.3 after via-filling electroplating using the leveling agent and plating solution of Example 1 of the present invention;

[0063] Fig. 9 : A cross-sectional view of a blind hole with a thickness-to-diameter ratio of 1.1 after via-filling electroplating using the leveling agent and the electroplating solution of Example 1 of the present invention;

[0064] Fig.10 : A cross-sectional view of a blind hole with a thickness-to-diameter ratio of 0.85 after via-filling electroplating using the leveling agent and plating solution of Example 1 of the present invention;

[0065] Fig.11 : A cross-sectional view of a blind hole with a thickness-to-diameter ratio of 0.68 after via-filling electroplating using the leveling agent and plating solution of Example 1 of the present invention. DETAILED DESCRIPTION

[0066] Example

[0067] A plating solution that can be used for filling micro blind vias: the components of the electrolyte are specifically shown in Table 2 below, and the solvent of the plating solution is deionized water.

[0068] The leveling agent in Examples 1-5 is a polymerization product of primary diamine, propargylamine, and trimethylolpropane triglycidyl ether, as shown in Table 2. The primary diamine is selected from the corresponding monomers according to Examples 1-5 for reaction.

[0069] The preparation method of the leveling agent is specifically as follows: (1) 18 g (0.060 mol) of polyol glycidyl ether (trimethylolpropane triglycidyl ether) is added to a round-bottomed reaction flask at room temperature (25°C), and then 40 mL of deionized water is added to the round-bottomed reaction flask, and nitrogen is filled in for protection. Under a nitrogen environment at 35°C, 0.067 mol of primary diamine and 2.5 g (0.045 mol) of propargylamine are added dropwise at a constant temperature and pressure, and the addition time is 15 min; after the addition, the temperature is kept constant at 35°C for 8 hours, and the mixture changes from the initially formed white suspension to a brown-yellow liquid. Further stirring is performed at room temperature (25°C) for another 2 hours, and the amber reaction product is finally obtained. The reaction product is transferred to a volumetric flask, washed and diluted with a 0.5 wt% sulfuric acid aqueous solution. (Note: The dilution multiple is not limited, and further purification is not required; it can be added according to the required amount of leveling agent)

[0070] The specific selection of the primary diamine in each embodiment is shown in Table 2; for example, in Embodiment 1, the primary diamine is 1,2-propylene diamine, and the addition amount is 5 g; the same applies to other embodiments.

[0071] Furthermore, the polyol glycidyl ether must be cooled to below 5° C. before participating in the reaction.

[0072] Table 2

[0073]

[0074]

[0075] A micro blind via copper plating process, the specific steps comprising:

[0076] S1. Inorganic dragging tank: add 2 / 3 volume of deionized water in the test line plating tank; start the circulation, filtration and temperature control system; slowly add sulfuric acid, and control the temperature in the bath not to exceed 50°C; add copper sulfate pentahydrate; hang the iridium-tantalum coated titanium anode wrapped in a double-layer anode bag; add deionized water, adjust and analyze the concentration of sulfuric acid, copper sulfate pentahydrate, and chloride ions to the formula concentration, add ferrous sulfate, add 1 / 2-2 / 3 of the volume of pure copper particles to the copper dissolving tank, and then start inorganic dragging tank; install a carbon core in the filter barrel of the test line plating tank to filter the electroplating tank liquid to remove organic pollutants that may remain in the tank liquid; drag the electroplating tank liquid at a current density of 10ASF for 2 hours; after the dragging tank is completed, use Hullcell sheets to confirm the contaminants in the tank liquid; electrolyze the Hullcell sheet at a current of 2A for 10 minutes, and the Hullcell sheet must not be shiny after electroplating. If it is shiny, continue electrolysis and carbon core filtration;

[0077] S2. Adding plating solution and dragging cylinder: adding organic components to the plating solution in sequence; then carrying out organic dragging cylinder, specifically analyzing the plating solution after 4 hours of electroplating at 5ASF, and then continuously electroplating the dragging cylinder at 10ASF for at least 4AH / L; after the dragging cylinder is completed, electroplating can be carried out;

[0078] S3. Electroplating reaction to obtain the first plating solution: Set the electroplating conditions to work at 23-25℃; operating parameters: 20ASF×60min. The anode is a Machnetal iridium-tantalum coated titanium mesh anode with low light agent consumption. The cathode and cathode area ratio is 1:2; the stirring method is spray convection stirring and cathode moving stirring; the filtering method is Zhengye brand conventional 20-inch electroplating copper cylinder filter barrel with cotton core for continuous filtration.

[0079] Note: The electroplating process requires maintenance of the plating solution: the plating solution lost due to evaporation can be supplemented with deionized water; the content of copper sulfate pentahydrate, sulfuric acid content, chloride content and iron ion / ferrous ion content are regularly analyzed; the concentration of additives (leveling agent, brightener, inhibitor) is adjusted according to CVS analysis. The copper source is supplemented by adding pure copper blocks or pure copper particles, and the iron content is analyzed by analyzing the ferrous content and ferric iron content to adjust the plating solution.

[0080] S4. The first plating solution is returned to the copper dissolving tank containing solid copper, and a second plating solution is obtained through an oxidation-reduction reaction; the oxidation-reduction reaction is Cu 0 +2Fe 3+ →2Fe 2+ +Cu 2+ , the copper dissolving condition is 25℃.

[0081] S5. Then, the second plating solution is introduced into the electrolyte, and steps S3 and S4 are repeated in sequence; the copper ions consumed in the electroplating process are replenished through reciprocating circulation. In step S5, the circulating plating solution dissolves copper until the line is stopped.

[0082] Performance Testing

[0083] The electroplating test substrate is: 4-layer substrate blind hole board, the board size is 40.64*50.8cm 2 , thickness is 1mm, the dielectric layer thickness on one side of the blind hole board is 25um, and the dielectric layer thickness on the other side is 85um. The different dielectric thickness layers on both sides are laser-plated with blind holes with apertures of 50μm, 65μm, 80μm, 100μm, and 125μm. The blind hole thickness-to-diameter ratio is 0.2-1.7. The test board is chemically copper-plated before testing, and the copper backlight is ≥ level 9.5.

[0084] The blind hole filling effect of the above embodiment 1 is shown in Figure 2-11 ; And, embodiments 2 to 8 can achieve similar electroplating effects as embodiment 1.

[0085] Blind hole filling performance evaluation: Figure 1As shown, H1 is calculated as the distance from the bottom of the blind hole to the copper layer just above, H2 is the sum of the thickness of the total dielectric layer and the copper layer, and H3 is the thickness of the copper plating layer (excluding the bottom copper). Calculate according to the formula: filling rate = (H1 / H2) × 100%, concavity = H2-H1.

[0086] The test results of copper plating thickness, filling rate and concavity of blind holes with different aspect ratios on different test carriers in Example 1 are shown in Table 3; and Examples 2 to 5 can achieve copper plating effects similar to that of Example 1.

[0087] Table 3

[0088]

[0089]

[0090] From Table 3 and Figure 2-11 It can be seen from the test results that the blind hole filling electroplating results of the electroplating solutions of Examples 1-5 are excellent, and the actual performance requirements can be met for blind holes with different aspect ratios on the carrier, especially the blind holes with high aspect ratios. When a thinner surface copper is plated, the surface of the carrier material is bright and there are no gaps or voids. It can be seen that the combination of the leveling agent, the electroplating solution and the copper plating process of the present invention can effectively improve the conductive properties, thermal properties and reliability of the carrier, and the product has no poor quality and has stable and reliable performance.

[0091] Note: All primary diamines, propargylamine and all polyol glycidyl ether substances exemplified in the technical scheme of the present invention can be arbitrarily combined in pairs to implement the method given in the embodiment for synthesis and testing, and the test results can achieve the effects given in the embodiment, that is, the primary diamines, propargylamine and polyol glycidyl ether substances exemplified in the present invention, as well as the preferred leveling agent are not limited to the limitations of the specific embodiments.

Claims

1. A leveling agent that can be used in a high aspect ratio micro blind hole filling copper plating process, characterized in that: The leveling agent is a polymerization product of a linear amine and a polyol glycidyl ether.

2. The leveling agent that can be used for high aspect ratio micro blind hole filling copper plating process according to claim 1, characterized in that: The linear amine is a primary diamine and / or an unsaturated linear amine; preferably, the linear amine is a composite of a primary diamine and an unsaturated linear monoamine.

3. The leveling agent for high aspect ratio micro blind via filling copper plating process according to claim 2, characterized in that: The molar ratio of the primary diamine, the unsaturated linear monoamine and the polyol glycidyl ether is 1:(0.4-1.2):(0.1-5).

4. The leveling agent for use in a high aspect ratio micro blind via filling copper plating process according to claim 1, characterized in that: The primary diamine is an alkyl primary diamine or a heteroatom-containing primary diamine.

5. The leveling agent for use in a high aspect ratio micro blind via filling copper plating process according to claim 4, characterized in that: The primary diamine has the structural formula shown in (1), (2) or (3): Wherein, n is 0-16; and n≠1.

6. The leveling agent for use in a high aspect ratio micro blind via filling copper plating process according to claim 4, characterized in that: The primary diamine is selected from at least one of hydrazine hydrate, ethylenediamine, 1,2-propylenediamine, 1,3-propylenediamine, 1,4-butylenediamine, 1,4-pentanediamine, 1,5-pentanediamine, 1,6-hexanediamine, 1,7-heptanediamine, diethylenetriamine, triethylenetetramine, tetraethylenepentamine, pentaethylenehexamine, adipic acid diamine, N-methyl-2,2'-diaminodiethylamine, and 2-methyl-1,3-propylenediamine.

7. The leveling agent for use in a high aspect ratio micro blind via filling copper plating process according to claim 6, characterized in that: The unsaturated straight-chain amine is propargylamine.

8. A method for preparing a leveling agent that can be used in a high aspect ratio micro blind via filling copper plating process according to claim 1, characterized in that: The preparation method of the leveling agent comprises: performing polymerization reaction on a linear amine and a polyol glycidyl ether under heating conditions to obtain the leveling agent; and the heating temperature is controlled at above 30°C.

9. An electroplating solution, characterized in that The components of the electroplating solution include: 170-300 g / L of copper ion salt, 20-150 g / L of acidic electrolyte, 10-120 mg / L of chloride ion, 1-160 g / L of iron ion salt, 0.1-10 mg / L of brightener, 5-12000 mg / L of inhibitor, 5-6000 mg / L of leveling agent according to any one of claims 1-7, and the solvent of the electroplating solution is deionized water; Preferably, the components of the electroplating solution include: 20-100 mg / L of chloride ions, 30-120 g / L of acidic electrolyte, 190-270 g / L of copper ion salt, 2-120 g / L of iron ion salt or ferrous salt, 0.5-6 mg / L of brightener, 10-10000 mg / L of inhibitor, 10-5000 mg / L of leveling agent according to any one of claims 1-7, and the solvent is deionized water.

10. A micro blind hole copper plating process, characterized in that: The micro blind hole copper plating process comprises: placing the electroplating solution of claim 9 on a printed circuit board having a plurality of micro blind holes for copper plating, wherein the temperature of the electroplating solution is 20-30° C.; After copper plating, the depression of the micro blind hole is less than 5μm and the filling rate is greater than 95%.

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