Copper electroplating additive for flexible circuit board and preparation method of copper electroplating additive
By preparing an electroplating copper additive with a general formula (I) structure, the shortcomings of the electroplating copper material of flexible circuit boards between high deep plating ability and good ductility are solved, and the deep plating ability of 150-200% and the elongation of more than 30% is achieved, which improves the reliability and stability of the flexible circuit board.
Patent Information
- Application Number
- CN202411558103.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-04
- Publication Date
- 2025-04-18
AI Technical Summary
The existing flexible circuit board electroplating copper materials are difficult to meet the requirements of high deep plating capabilities and good ductility, especially in terms of deep plating capabilities of 150-200% and elongation of more than 30%.
An electroplating copper additive of general formula (I) is provided. The preparation method includes adding anhydrous ethanol and imidazoline to a three-necked flask, gradually adding glycidyl ether after controlling the temperature, then adding sulfonolide and halogenate, adjusting the pH value and carrying out reaction, and finally obtaining an electroplating copper additive with high deep plating ability and good ductility.
The electroplating copper additive can significantly improve the deep plating capacity and ductility of the flexible circuit board, meet the requirements of 150-200% deep plating capacity and more than 30% elongation, improve the reliability and stability of the flexible circuit board. At the same time, the production method is simple and suitable for large-scale production.
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Figure CN119843327A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the field of copper electroplating of flexible circuit boards (FPC soft boards), and in particular relates to a copper electroplating additive for flexible circuit boards and a preparation method thereof. Background Art
[0002] Flexible circuit board, referred to as FPC soft board, is a special process board. FPC soft board requires good ductility of electroplated copper because FPC soft board needs to have high flexibility and bendability. During the production process, a layer of copper needs to be electroplated on the flexible substrate to form a conductive circuit. In order for the FPC soft board to adapt to various bending and deformation, the electroplated copper layer needs to have good ductility so that it will not crack or fall off during the bending process. When making FPC soft boards, it is necessary to select appropriate electroplating processes and materials, and control the thickness and ductility of the electroplated copper layer to ensure the reliability and stability of the flexible circuit board. At present, with the refinement of electronic products, the deep plating ability and ductility requirements of FPC soft board copper plating have become higher, and the deep plating ability needs to reach 150-200%, and the ductility needs to reach an elongation of more than 30%. At this stage, the electroplated copper of the soft board through hole is difficult to meet such requirements.
[0003] Therefore, the FPC soft board copper plating field needs to develop an electroplating copper additive that has both high deep plating ability and good ductility. Summary of the invention
[0004] The object of the present invention is to provide a copper electroplating additive having both high throwing power and good ductility.
[0005] The first aspect of the present invention provides a copper electroplating additive for a flexible circuit board, wherein the additive has the following general formula (I): ; In the general formula (I), R1 and R2 are methyl, ethyl, propyl, sodium propanesulfonate, sodium butanesulfonate, 2-propyl, 2-butyl, pentyl, 2-pentyl, 3-pentyl, hexyl, 2-hexyl, 3-hexyl, heptyl, 2-heptyl, 3-heptyl, 4-heptyl, octyl, 2-octyl, 3-octyl, 4-octyl, nonyl, 2-nonyl, 3-nonyl, 4-nonyl, 5-nonyl, decyl, 2-decyl, 3-decyl, 4-decyl, 5-decyl, benzyl, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, sodium 2-propylenesulfonate, sodium 2-methylpropanesulfonate, 3,5-dimethylbenzyl, 2-methoxybenzyl, 3-methoxybenzyl, 4- any one of methoxybenzyl, 2-nitrobenzyl, 3-nitrobenzyl, 4-nitrobenzyl, 2-trifluoromethylbenzyl, 2-chlorobenzyl, 3-chlorobenzyl, 4-chlorobenzyl, 2-bromobenzyl, 3-bromobenzyl, 4-bromobenzyl, 2-fluorobenzyl, 3-fluorobenzyl, 4-fluorobenzyl, 3-trifluoromethylbenzyl, 4-trifluoromethylbenzyl, phenethyl, phenylpropyl, allyl, allyl, 3-fluoro-5-trifluoromethylbenzyl, 3-fluoro-4-nitrobenzyl, 2-chloro-4,5-difluorobenzyl bromide, 2-ethylbenzyl, 3-ethylbenzyl, 4-ethylbenzyl, 2,6-difluoro-4-methoxybenzyl and 2,6-difluoro-4-methoxy; wherein n is 2-4.
[0006] The second aspect of the present invention provides a method for preparing an electroplating copper additive for a flexible circuit board, wherein the preparation method of the general formula (I) is: a. Add anhydrous ethanol to a three-necked flask, then add 1 part of imidazoline to the flask, then control the temperature at 0-20°C, add 0.5-1 part of glycidyl ether to the flask in ten batches, add each batch at an interval of 5-30min, and react for 2-4h after addition; after the reaction is completed, raise the temperature to room temperature, and the glycidyl ether is one or more of ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butanediol diglycidyl ether, pentanediol diglycidyl ether, and hexanediol diglycidyl ether; b. Add 0.1-2 parts of sultone to the flask after the reaction in step a, stir and react for 5-10 hours, raise the temperature to 78 ° C after the reaction, add an inorganic base to adjust the pH to 12, wherein the sultone is one or more of propane sultone, butane sultone, 2-butane sultone, and propenyl-1,3-propane sultone, and the inorganic base is one or more of sodium hydroxide or potassium hydroxide; c. Add 0.1-2 parts of the halogenated compound to the flask, continue the reaction for 10-30 hours, add pure water and stir after the reaction is completed, and the halogenated compound has the following general formula (II): ; In the general formula (II), X is any one of chlorine, bromine and iodine; R3 is methyl, ethyl, propyl, 2-propyl, 2-butyl, pentyl, 2-pentyl, 3-pentyl, hexyl, 2-hexyl, 3-hexyl, heptyl, 2-heptyl, 3-heptyl, 4-heptyl, octyl, 2-octyl, 3-octyl, 4-octyl, nonyl, 2-nonyl, 3-nonyl, 4-nonyl, 5-nonyl, decyl, 2-decyl, 3-decyl, 4-decyl, 5-decyl, benzyl, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 3,5-dimethylbenzyl, 2-methoxybenzyl, 3-methoxybenzyl, 4-methoxybenzyl, 2 -nitrobenzyl, 3-nitrobenzyl, 4-nitrobenzyl, 2-trifluoromethylbenzyl, 2-chlorobenzyl, 3-chlorobenzyl, 4-chlorobenzyl, 2-bromobenzyl, 3-bromobenzyl, 4-bromobenzyl, 2-fluorobenzyl, 3-fluorobenzyl, 4-fluorobenzyl, 3-trifluoromethylbenzyl, 4-trifluoromethylbenzyl, phenethyl, phenylpropyl, allyl, allyl, 3-fluoro-5-trifluoromethylbenzyl, 3-fluoro-4-nitrobenzyl, 2-chloro-4,5-difluorobenzyl bromide, 2-ethylbenzyl, 3-ethylbenzyl, 4-ethylbenzyl, 2,6-difluoro-4-methoxybenzyl, 2,6-difluoro-4-methoxy.
[0007] As a preferred technical solution, the molar mass ratio of sultone to halide in step b and step c is 1:10-10:1.
[0008] As a preferred technical solution, the molar mass ratio of imidazoline to (halide and sultone) in step a and step b is 1:1-1:3.
[0009] As a preferred technical solution, the molar mass ratio of imidazoline to glycidyl ether in step a is 1:1-2:1.
[0010] As a preferred technical solution, the amount of anhydrous ethanol used in step a is 3-10 times the total mass of imidazoline, glycidyl ether, sultone, and halide, and the amount of pure water added is 3-20 times the total mass of imidazoline, glycidyl ether, sultone, and halide.
[0011] The third aspect of the present invention provides a copper plating solution, wherein the effective content of the above-prepared flexible circuit board electroplating copper additive in the copper plating solution is 1-100 ppm.
[0012] Beneficial Effects The novel additive for FPC soft board electroplating copper provided by the present invention can enable the hole copper plating of the soft board to obtain good deep plating ability and good ductility, thereby improving the reliability and stability of the flexible circuit board. The production method thereof is simple and suitable for mass production.
[0013] The novel electroplating copper additive provided by the present invention has a small amount of addition, and its preparation raw materials are extensive, easy to obtain and prepare, and has a relatively low cost.
[0014] By using the novel additive in the copper electroplating of the FPC soft board provided by the present invention, a sufficiently thick coating can be obtained in a shorter time, production efficiency can be improved, and time, labor and material costs can be saved. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 This is a cross-section diagram of a plated hole with a deep plating capacity of 182%. Figure 2 This is a cross-section diagram of a plated hole with a deep plating capacity of 178%. Figure 3 This is a cross-section diagram of a plated hole with a deep plating capacity of 167%. Figure 4 This is a cross-section diagram of a plated hole with a deep plating capacity of 172%. Figure 5 This is a cross-section diagram of a plated hole with a deep plating capacity of 185%. Figure 6 This is a cross-section diagram of a plated hole with a deep plating capacity of 115%. Figure 7 This is a cross-section diagram of a plated hole with a deep plating capacity of 123%. DETAILED DESCRIPTION
[0015] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0016] Example 1 This embodiment provides a method for preparing a structural additive of general formula (I), comprising the following steps: ;
[0017] (1) Add 100 ml of anhydrous ethanol to a 500 ml three-necked flask, then add 7.2 g of imidazoline to the flask, then control the temperature at 0-20°C, add 10 g of ethylene glycol diglycidyl ether (m=1) to the flask in ten batches, with an interval of 5-30 min between each batch, and react for 3 hours after the addition is complete; after the reaction is completed, raise the temperature to room temperature; (2) Add 2.44 g of 1,3-propane sultone to the flask after the reaction in step (1), stir and react for 5 h. After the reaction is completed, raise the temperature to 78 ° C. and add 1.5 g of sodium hydroxide to adjust the pH to 12; (3) Add 10.08 g of benzyl chloride to the flask and continue the reaction for 24 hours. After the reaction is completed, add 150 ml of pure water and stir. The product can be used as an additive for copper plating on FPC flexible circuit boards without purification. It is named Additive A. The mass fraction of Additive A in water is 10.47% (w / w).
[0018] Example 2 This embodiment provides a method for preparing a structural additive of general formula (I), comprising the following steps: ;
[0019] (1) Add 100 ml of anhydrous ethanol to a 500 ml three-necked flask, then add 7.2 g of imidazoline to the flask, then control the temperature at 0-20°C, add 15.5 g of 1,6-diol diglycidyl ether (m=5) to the flask in ten batches, with an interval of 5-30 min between each batch, and react for 3 hours after the addition is completed; after the reaction is completed, raise the temperature to room temperature; (2) Add 3 g of 1,3-propane sultone to the flask after the reaction in step (1), stir and react for 5 h. After the reaction is completed, raise the temperature to 78 ° C. and add 1.8 g of sodium hydroxide to adjust the pH to 12; (3) Add 9 g of benzyl chloride to the flask and continue the reaction for 24 hours. After the reaction is completed, add 150 ml of pure water and stir. The product can be used as an additive for copper plating on FPC flexible circuit boards without purification. It is named Additive B. The mass concentration of Additive B in water is 12.1% (w / w).
[0020] Example 3 This embodiment provides a method for preparing a structural additive of general formula (I), comprising the following steps: ;
[0021] (1) Add 100 ml of anhydrous ethanol to a 500 ml three-necked flask, then add 7.2 g of imidazoline to the flask, then control the temperature at 0-20°C, add 13.5 g of 1,4-diol diglycidyl ether (m=3) to the flask in ten batches, with an interval of 5-30 min between each batch, and react for 3 hours after the addition is completed; after the reaction is completed, raise the temperature to room temperature; (2) Add 3 g of 1,3-propane sultone to the flask after the reaction in step (1), stir and react for 5 h. After the reaction is completed, raise the temperature to 78 ° C. and add 1.8 g of sodium hydroxide to adjust the pH to 12; (3) Add 9 g of benzyl chloride to the flask and continue the reaction for 24 h. After the reaction is completed, add 150 ml of pure water and stir. The product can be used as an additive for copper plating on FPC flexible boards without purification. It is named Additive C. The mass concentration of Additive C in water is 11.45% (w / w).
[0022] Example 4 This embodiment provides a method for preparing a structural additive of general formula (I), comprising the following steps: ; (1) Add 100 ml of anhydrous ethanol to a 500 ml three-necked flask, then add 7.2 g of imidazoline to the flask, then control the temperature to 0-20°C, add 5 g of ethylene glycol diglycidyl ether (m=1) and 8 g of 1,4-butanediol diglycidyl ether (m=5) to the flask in ten batches, with an interval of 5-30 min between each batch, and react for 3 hours after the addition is completed; after the reaction is completed, raise the temperature to room temperature; (2) Add 2.44 g of 1,3-propane sultone to the flask after the reaction in step (1), stir and react for 5 h. After the reaction is completed, raise the temperature to 78 ° C. and add 1.5 g of sodium hydroxide to adjust the pH to 12; (3) Add 10.08 g of benzyl chloride to the flask and continue the reaction for 24 hours. After the reaction is completed, add 150 ml of pure water and stir. The product can be used as an additive for copper plating on FPC flexible circuit boards without purification. It is named Additive D. The mass concentration of Additive D in water is 11.49% (w / w).
[0023] Example 5 This embodiment provides a method for preparing a structural additive of general formula (I), comprising the following steps: ; (1) Add 100 ml of anhydrous ethanol to a 500 ml three-necked flask, then add 7.2 g of imidazoline to the flask, then control the temperature at 0-20°C, add 5 g of 1,4-diol diglycidyl ether (m=3) and 10 g of 1,6-hexanediol diglycidyl ether (m=5) to the flask in ten batches, with an interval of 5-30 min between each batch, and react for 3 hours after the addition is completed; after the reaction is completed, raise the temperature to room temperature; (2) Add 3 g of 1,3-propane sultone to the flask after the reaction in step (1), stir and react for 5 h. After the reaction is completed, raise the temperature to 78 ° C. and add 1.8 g of sodium hydroxide to adjust the pH to 12; (3) Add 9 g of benzyl chloride to the flask and continue the reaction for 24 h. After the reaction is completed, add 150 ml of pure water and stir. The product can be used as an additive for copper plating on FPC flexible boards without purification. It is named Additive E. The mass concentration of Additive E in water is 11.95% (w / w).
[0024] Comparative Example 1 This embodiment provides a method for preparing an F additive, comprising the following steps: (1) Add 100 ml of anhydrous ethanol to a 500 ml three-necked flask, then add 7.2 g of imidazoline to the flask, then control the temperature at 0-20°C, add 10 g of ethylene glycol diglycidyl ether (m=1) to the flask in ten batches, with an interval of 5-30 min between each batch, and react for 3 hours after the addition is complete; after the reaction is completed, raise the temperature to 78°C; (2) Add 15 g of benzyl chloride to the flask and continue the reaction for 24 hours. After the reaction is completed, add 150 ml of pure water and stir. The product can be used as an additive for copper plating on FPC flexible boards without purification. It is named Additive F. The mass concentration of Additive F in water is 10.9% (w / w).
[0025] Comparative Example 2 This embodiment provides a method for preparing a G additive, comprising the following steps: (1) Add 100 ml of anhydrous ethanol to a 500 ml three-necked flask, then add 7.2 g of imidazoline to the flask, then control the temperature at 0-20°C, add 5 g of 1,4-diol diglycidyl ether and 10 g of 1,6-hexanediol diglycidyl ether to the flask in ten batches, with an interval of 5-30 minutes between each batch, and react for 3 hours after the addition is completed; after the reaction is completed, raise the temperature to 50°C; (2) Add 6 g of 1,3-propane sultone into the flask and continue the reaction for 24 hours. After the reaction is completed, add 150 ml of pure water and stir. The product can be used as an additive for copper plating on FPC flexible boards without purification. It is named Additive G. The mass concentration of Additive G in water is 10.96% (w / w).
[0026] Test Example 1 The FPC soft board is used as a plating test piece and electroplated in electroplating copper plating solutions containing different additives to test different properties. The specific implementation steps include: 1. Preparation of electroplating copper solution Seven groups of additives (test numbers 1 to 7) are set, where: numbers 1 to 5 are A to E prepared in Examples 1 to 5 respectively; numbers 6 and 7 are F and G prepared in Comparative Examples 1 and 2. The seven groups of additives are mixed with copper sulfate pentahydrate, sulfuric acid, chloride ions, polyethylene glycol 10000, SPS (sodium polydisulfide dipropane sulfonate) and deionized water to prepare electroplating copper plating solution. The content of each component of the electroplating copper plating solution is: 75g / L copper sulfate pentahydrate, 220g / L sulfuric acid, 65ppm chloride ions, 600ppm polyethylene glycol 10000, 5ppm SPS, and the balance is deionized water.
[0027] 2. Electroplating conditions Electroplating test piece: The thickness of the electroplating board (PCB) is 0.075mm, the through hole diameter is 0.5mm, the board length is 20cm, and the width is 5.5cm. The electroplating parameters are 25ASF The test was carried out in a Haring trough for 50 minutes using a technique known in the art.
[0028] 3. After the test is completed, slice and measure the surface copper and hole copper plating thickness of each group of test boards. Use the following formula to calculate the deep plating ability.
[0029] ; 4. The elongation test is carried out according to 2.4.18 of IPC-TM-650. The test results are shown in Table 1 below.
[0030] Table 1 Deep plating ability of the test piece of the plating solution prepared in the examples and comparative examples
[0031] It can be seen from Table 1 that the electroplating solution prepared with the soft board copper plating additives prepared in Examples 1-5 can enable the soft board test piece to obtain good deep plating ability, and the ductility can reach more than 30%; while the electroplating solution prepared with additives F and G prepared in Comparative Examples 1-2 has a deep plating ability that does not meet the soft board plating requirements, and the ductility tests are only 24% and 22%, which does not achieve a high ductility effect of 30%.
[0032] The above is a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.
Claims
1. A copper electroplating additive for flexible circuit boards, characterized in that: The additive has the following general formula (I): ； In the general formula (I), R1 and R2 are methyl, ethyl, propyl, sodium propanesulfonate, sodium butanesulfonate, 2-propyl, 2-butyl, pentyl, 2-pentyl, 3-pentyl, hexyl, 2-hexyl, 3-hexyl, heptyl, 2-heptyl, 3-heptyl, 4-heptyl, octyl, 2-octyl, 3-octyl, 4-octyl, nonyl, 2-nonyl, 3-nonyl, 4-nonyl, 5-nonyl, decyl, 2-decyl, 3-decyl, 4-decyl, 5-decyl, benzyl, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, sodium 2-propylenesulfonate, sodium 2-methylpropanesulfonate, 3,5-dimethylbenzyl, 2-methoxybenzyl, 3-methoxybenzyl, 4- any one of methoxybenzyl, 2-nitrobenzyl, 3-nitrobenzyl, 4-nitrobenzyl, 2-trifluoromethylbenzyl, 2-chlorobenzyl, 3-chlorobenzyl, 4-chlorobenzyl, 2-bromobenzyl, 3-bromobenzyl, 4-bromobenzyl, 2-fluorobenzyl, 3-fluorobenzyl, 4-fluorobenzyl, 3-trifluoromethylbenzyl, 4-trifluoromethylbenzyl, phenethyl, phenylpropyl, allyl, allyl, 3-fluoro-5-trifluoromethylbenzyl, 3-fluoro-4-nitrobenzyl, 2-chloro-4,5-difluorobenzyl bromide, 2-ethylbenzyl, 3-ethylbenzyl, 4-ethylbenzyl, 2,6-difluoro-4-methoxybenzyl and 2,6-difluoro-4-methoxy; wherein n is 2-4.
2. A method for preparing the copper electroplating additive for flexible circuit boards according to claim 1, characterized in that: The preparation method of the structural formula (I) comprises at least the following steps: a. Add anhydrous ethanol to a three-necked flask, then add 1 part of imidazoline to the flask, then control the temperature at 0-20°C, add 0.5-1 part of glycidyl ether to the flask in ten batches, add each batch at an interval of 5-30min, and react for 2-4h after addition; after the reaction is completed, raise the temperature to room temperature, and the glycidyl ether is one or more of ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butanediol diglycidyl ether, pentanediol diglycidyl ether, and hexanediol diglycidyl ether; b. Add 0.1-2 parts of sultone to the flask after the reaction in step a, stir and react for 5-10 hours, raise the temperature to 78 ° C after the reaction, add an inorganic base to adjust the pH to 12, wherein the sultone is one or more of propane sultone, butane sultone, 2-butane sultone, and propenyl-1,3-propane sultone, and the inorganic base is one or more of sodium hydroxide or potassium hydroxide; c. Add 0.1-2 parts of the halogenated compound to the flask, continue the reaction for 10-30 hours, add pure water and stir after the reaction is completed, and the halogenated compound has the following general formula (II): ； In the general formula (II), X is any one of chlorine, bromine and iodine; R3 is methyl, ethyl, propyl, 2-propyl, 2-butyl, pentyl, 2-pentyl, 3-pentyl, hexyl, 2-hexyl, 3-hexyl, heptyl, 2-heptyl, 3-heptyl, 4-heptyl, octyl, 2-octyl, 3-octyl, 4-octyl, nonyl, 2-nonyl, 3-nonyl, 4-nonyl, 5-nonyl, decyl, 2-decyl, 3-decyl, 4-decyl, 5-decyl, benzyl, 2-methylbenzyl, 3-methylbenzyl, 4-methylbenzyl, 3,5-dimethylbenzyl, 2-methoxybenzyl, 3-methoxybenzyl, 4-methoxybenzyl, 2 -nitrobenzyl, 3-nitrobenzyl, 4-nitrobenzyl, 2-trifluoromethylbenzyl, 2-chlorobenzyl, 3-chlorobenzyl, 4-chlorobenzyl, 2-bromobenzyl, 3-bromobenzyl, 4-bromobenzyl, 2-fluorobenzyl, 3-fluorobenzyl, 4-fluorobenzyl, 3-trifluoromethylbenzyl, 4-trifluoromethylbenzyl, phenethyl, phenylpropyl, allyl, allyl, 3-fluoro-5-trifluoromethylbenzyl, 3-fluoro-4-nitrobenzyl, 2-chloro-4,5-difluorobenzyl bromide, 2-ethylbenzyl, 3-ethylbenzyl, 4-ethylbenzyl, 2,6-difluoro-4-methoxybenzyl, 2,6-difluoro-4-methoxy.
3. The method for preparing an additive for electroplating copper on flexible circuit boards according to claim 2, characterized in that: The molar mass ratio of sultone to halide in step b and step c is 1:10-10:
1.
4. The method for preparing an additive for electroplating copper on flexible circuit boards according to claim 2, characterized in that: The molar mass ratio of imidazoline to (halide and sultone) in step a and step b is 1:1-1:
3.
5. The method for preparing an additive for electroplating copper on flexible circuit boards according to claim 2, characterized in that: The molar mass ratio of imidazoline to glycidyl ether in step a is 1:1-2:
1.
6. The method for preparing an additive for electroplating copper on flexible circuit boards according to claim 2, characterized in that: The amount of anhydrous ethanol used in step a is 3-10 times the total mass of imidazoline, glycidyl ether, sultone and halide, and the amount of pure water added is 3-20 times the total mass of imidazoline, glycidyl ether, sultone and halide.
7. A copper plating solution, characterized in that The effective content of the flexible circuit board electroplating copper additive prepared according to any one of claims 2 to 6 in the copper plating solution is 1 to 100 ppm.