WO2022082933A1

WO2022082933A1 - Production method for ultrathin high-strength electronic copper foil

Info

Publication number: WO2022082933A1
Application number: PCT/CN2020/132527
Authority: WO
Inventors: 金荣涛; 江泱; 范远朋
Original assignee: 九江德福科技股份有限公司
Priority date: 2020-10-19
Filing date: 2020-11-28
Publication date: 2022-04-28
Also published as: CN112226790A; CN112226790B

Abstract

A production method for an ultrathin high-strength electronic copper foil, comprising the following steps: preparing an electrolyte, adding a mixed additive, manufacturing an isolation layer by using a copper foil having the thickness of 18 to 35 microns as a cathode carrier, electrodepositing an ultrathin copper foil layer having the thickness of 2.5 to 5 microns to form a carrier copper foil, carrying out chemical micro-coarsening treatment on a rough surface of the carrier copper foil, and carrying out organic film coating to form the ultrathin high-strength electronic copper foil. In the production method, the specific surface area can be increased by means of micro-coarsening; by coating the organic layer, the anti-stripping strength can be improved, and the foil can be effectively prevented from being oxidized; the isolation layer is produced on the carrier, so that the binding force between the ultrathin copper foil and the carrier is reduced, and the ultrathin copper foil and the carrier can be easily separated by a mechanical force. The production method is simple in process steps and capable of realizing continuous production, and is an efficient carrier high-strength ultrathin copper foil production process.

Description

A kind of production method of ultra-thin high-strength electronic copper foil

technical field

The invention relates to the technical field of copper foil production methods, in particular to a production method of ultra-thin high-strength electronic copper foil.

Background technique

Electrolytic copper foil is an important raw material for the electronic information industry. With the development of technology, electronic products tend to be multi-functional, light and thin. Therefore, the copper foil substrate that forms the printed circuit is also required to be thinner and the roughness is smaller, which is convenient for the processing of fine lines; especially 5G products, ultra-thin and low-roughness copper foil is required to support.

The traditional electrolytic copper foil manufacturing uses a cathode roller as the cathode. In the copper sulfate aqueous solution, the surface of the cathode roller is electroplated to form a copper layer that is directly peeled off to form a wool foil. Oxidation treatment. This process has several disadvantages: 1) The thickness of the copper foil cannot be made very thin; 2) The ultra-thin copper foil is easily wrinkled during subsequent processing by downstream customers (printed circuit board factories), which affects the quality and yield. 3) The roughness of the electrochemically roughened copper foil increases, which significantly increases the impact on high-frequency and high-speed signal transmission; 4) The strength of the copper foil is low and cannot meet the needs. As the line width of the PCB and IC carrier board is getting smaller and smaller, the copper foil is getting thinner and thinner, and the heat generation of the components increases. Cracks appear in the copper foil lines of the board, greatly increasing the risk of breakage.

For the problems in the related technologies, no effective solutions have been proposed so far.

SUMMARY OF THE INVENTION

In view of the above-mentioned technical problems in the related art, the purpose of the present invention is to provide a method for producing an ultra-thin high-strength electronic copper foil, which overcomes the deficiencies in the prior art.

For realizing the above-mentioned technical purpose, the technical scheme of the present invention is realized like this:

A production method of ultra-thin high-strength electronic copper foil, comprising the following steps:

S1, prepare electrolyte with copper pyrophosphate, potassium pyrophosphate and ammonium citrate;

S2. Add mixed additives and pass through multi-stage filtration;

S3, use the copper foil with a thickness of 18-35 microns as a cathode carrier, and use any known method to make a separation layer on the cathode carrier;

S4, adding the cathode carrier with the isolation layer to the solution of step S2, and electrodepositing an ultra-thin copper foil layer with a thickness of 2.5-5 microns at a current density of ^150-500A /dm to form a carrier copper foil;

S5, use a roughening solution composed of sulfuric acid, hydrogen peroxide, trisodium phosphate and a wetting agent to chemically micro-roughen the rough surface of the carrier copper foil;

S6. After the rough surface of the carrier copper foil is chemically micro-roughened, it is coated with an organic film to form an ultra-thin and high-strength electronic copper foil.

Further, in step S2, the mixed additive contains agent A, agent B, agent C and chloride ion, and agent A contains at least thiazolidinethione, aliphatic amine ethoxysulfonate, sodium mercaptoimidazole propanesulfonate And a kind of in azozine dye, described B agent is to contain polydithiodipropane sulfonate sodium, alcohol thio propane sulfonate sodium, dimethylformamido sulfonate sodium, thiimidyl dithiosulfonate A kind of propane sulfonic acid, and the C agent is a kind of polyethylene glycol and sodium dodecyl benzene sulfonate.

Further, the concentrations of the copper pyrophosphate, potassium pyrophosphate and ammonium citrate are respectively 80-120 g/L, 300-400 g/L and 15-35 g/L.

Further, the concentrations of agent A, agent B and agent C are respectively 3-50 mg/L, 3-80 mg/L and 1-20 mg/L.

Further, the concentrations of sulfuric acid, hydrogen peroxide, trisodium phosphate and wetting agent in the crude solution are respectively 25-55g/L, 30-60g/L, 50-80g/L and 5-25mg/L.

Further, the temperature of the roughening solution is 35°C, and the chemical micro-roughening treatment time is 38-55 seconds.

Further, the organic film adopts a sprayed aqueous solution of 3-glycidyloxypropyltrimethoxysilane.

Further, the thickness of the isolation layer is 0.05-0.1 microns.

Another aspect of the present invention also provides an ultra-thin and high-strength electronic copper foil, which is prepared by the above-mentioned production method, and includes a carrier, the carrier is provided with an isolation layer, and the isolation layer is provided with an ultra-thin copper foil, The ultra-thin copper foil is provided with a roughened layer and an organic layer; its tensile strength is greater than 60-80Kg/mm ² , its elongation is greater than 3.0%, and its peel strength is greater than or equal to 0.7N/mm.

Beneficial effects of the present invention: The present invention adopts 18-35 micron copper foil as the cathode carrier, and carries out electrochemical deposition on the surface of the carrier in the mixed solution of copper pyrophosphate, potassium pyrophosphate and additives to form ultra-thin copper with a thickness of 2.5-5 microns The foil layer, after micro-roughening, can increase the specific surface area; by coating the organic layer, the anti-peel strength can be improved and the oxidation of the foil can be effectively prevented; by preparing an isolation layer on the carrier, the ultra-thin copper foil and the carrier The binding force is reduced, and the two are easily separated by mechanical force; the process steps are simple, continuous production is possible, and it is an efficient carrier high-strength ultra-thin copper foil production process.

Description of drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings required in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some of the present invention. In the embodiments, for those of ordinary skill in the art, other drawings can also be obtained according to these drawings without any creative effort.

1 is a structural diagram of an ultra-thin and high-strength electronic copper foil prepared by a method for producing an ultra-thin and high-strength electronic copper foil according to an embodiment of the present invention.

In the figure: 1, carrier; 2, isolation layer; 3, ultra-thin copper foil; 4, roughened layer and organic layer.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art fall within the protection scope of the present invention.

One aspect of the present invention provides a method for producing an ultra-thin high-strength electronic copper foil, comprising the following steps:

S2. Add mixed additives and pass through multi-stage filtration;

S3. Use a copper foil with a thickness of 18-35 microns as a cathode carrier, and use any known method to make an isolation layer on the cathode carrier to facilitate the separation of the ultra-thin high-tensile copper foil from the carrier after lamination;

S4, adding the cathode carrier with the isolation layer to the solution of step S2, and electrodepositing an ultra-thin copper foil layer with a thickness of 2.5-5 microns to form a carrier copper foil;

S6. After the rough surface of the carrier copper foil is chemically micro-roughened, it is coated with an organic film to form an ultra-thin and high-strength electronic copper foil, which meets the PCB requirements.

In a specific embodiment of the present invention, the mixed additive in step S2 includes agent A, agent B, agent C and chloride ion, and agent A is at least thiazolidinethione, aliphatic amine ethoxysulfonate , a kind of in mercaptoimidazole propane sulfonate sodium and azozine dye, described B agent is to contain polydithiodipropane sulfonate sodium, alcohol thio propane sulfonate sodium, dimethylformamido sulfonate sodium, A kind of thiimidyl dithiopropane sulfonic acid, and the C agent is a kind of polyethylene glycol and sodium dodecyl benzene sulfonate.

In a specific embodiment of the present invention, the concentrations of the copper pyrophosphate, potassium pyrophosphate and ammonium citrate are 80-120 g/L, 300-400 g/L and 15-35 g/L, respectively.

In a specific embodiment of the present invention, the concentrations of agent A, agent B and agent C are 3-50 mg/L, 3-80 mg/L and 1-20 mg/L, respectively.

In a specific embodiment of the present invention, the concentrations of sulfuric acid, hydrogen peroxide, trisodium phosphate and wetting agent in the roughening solution are respectively 25-55g/L, 30-60g/L, 50-80g/L and 5- 25mg/L.

In a specific embodiment of the present invention, the temperature of the roughening solution is 35° C., and the chemical micro-roughening treatment time is 38-55 seconds.

In a specific embodiment of the present invention, the organic film adopts a sprayed aqueous solution of 3-glycidyloxypropyltrimethoxysilane.

In a specific embodiment of the present invention, the thickness of the isolation layer is 0.05-0.1 μm.

Another aspect of the present invention also provides an ultra-thin and high-strength electronic copper foil, which is prepared by the above-mentioned production method. It is assumed that an ultra-thin copper foil 3 is arranged on the isolation layer 2 , and a roughened layer and an organic layer 4 are arranged on the ultra-thin copper foil 3 .

In order to facilitate the understanding of the above-mentioned technical solutions of the present invention, the above-mentioned technical solutions of the present invention will be described in detail below through specific usage modes.

Example 1

Chemically pure copper pyrophosphate, potassium pyrophosphate and ammonium citrate are prepared with pure water according to the concentration of 100g/L, 350g/L and 25g/L, respectively, add agent A tetrahydrothiazolthione 5mg/l, agent B 3-mercapto -Sodium 1-propanesulfonate 8mg/l and C agent polyethylene glycol 10mg/l, after 5 micron, 1 micron and 0.5 micron multi-stage filtration, at a temperature of 55 ℃, in a smooth surface of copper foil with a thickness of 18 microns. A zinc layer with a thickness of 0.01-0.05 microns is deposited as an isolation layer, a titanium anode is used, and a current density of 300 A/dm ² is used to electrodeposit an ultra-thin copper foil layer with a thickness of 5 microns on the isolation layer.

An ultra-thin copper foil with a thickness of 5 microns is attached to a cathode carrier with a thickness of 18 microns to form a carrier copper foil.

The carrier copper foil is chemically micro-roughened in a roughening solution prepared with pure water to increase the specific surface area of the ultra-thin and ultra-strong electronic copper foil. The roughening solution is composed of sulfuric acid, hydrogen peroxide, trisodium phosphate and a wetting agent. 25g/L, 30g/L, 50g/L and 5mg/L. The temperature of the roughening solution was 35°C, and the treatment time was 55 seconds.

After micro-roughening, anti-peel strength enhancement and anti-oxidation treatment are carried out, and a 0.5% concentration of 3-glycidyloxypropyltrimethoxysilane aqueous solution is sprayed on the surface of the ultra-thin high-tensile carrier copper foil to form an organic film.

Example 2

In this example, sodium mercaptoimidazole propanesulfonate, sodium alcoholthiopropanesulfonate and sodium dodecylbenzenesulfonate are used as additives to electrodeposit an ultra-thin copper foil with a thickness of 4 microns.

Prepare chemically pure copper pyrophosphate, potassium pyrophosphate and ammonium citrate with pure water according to the concentration of 100g/L, 350g/L and 25g/L, and add agent A 8mg/l sodium mercaptoimidazole propanesulfonate and agent B alcohol sulfur respectively. 10mg/l of sodium propane sulfonate and 15mg/l of sodium dodecylbenzene sulfonate as agent C, after 5 micron, 1 micron and 0.5 micron multi-stage filtration, at the temperature of 55 ℃, in 18 micron copper foil smooth surface A zinc layer with a thickness of 0.01-0.05 microns was deposited as an isolation layer, and an ultra-thin copper foil layer with a thickness of 4 microns was electrodeposited on the isolation layer with a titanium anode and a current density of 280 A/dm ² .

An ultra-thin copper foil with a thickness of 4 microns is attached to a cathode carrier with a thickness of 18 microns to form a carrier copper foil.

The carrier copper foil is chemically roughened in a roughening solution prepared with pure water to increase the specific surface area of the ultra-thin and super-strong copper foil. The roughening solution is composed of sulfuric acid, hydrogen peroxide, trisodium phosphate and a wetting agent, and its concentration is 25/L. , 30g/L, 50g/L and 5mg/L, the temperature of the roughening solution is 35°C, and the treatment time is 50 seconds.

Example 3

Prepare chemically pure copper pyrophosphate, potassium pyrophosphate and ammonium citrate with pure water according to the concentration of 100g/L, 350g/L and 25g/L respectively, add agent A tetrahydrothiazolthione 5mg/l, agent B 3- Sodium mercapto-1-propane sulfonate 8mg/l and C agent polyethylene glycol 10mg/l, after 5 micron, 1 micron and 0.5 micron multi-stage filtration, at the temperature of 55 ℃, on 18 micron copper foil smooth electrodeposition A zinc layer with a thickness of 0.01-0.05 microns is used as the isolation layer, and an ultra-thin copper foil layer with a thickness of 2.5 microns is electrodeposited on the isolation layer with a titanium anode and a current density of 280A/dm ² .

An ultra-thin copper foil with a thickness of 2.5 microns is attached to a cathode carrier with a thickness of 18 microns to form a carrier copper foil.

The carrier copper foil is chemically roughened in a roughening solution prepared with pure water to increase the specific surface area of the ultra-thin and super-strong copper foil. The roughening solution is composed of sulfuric acid, hydrogen peroxide, trisodium phosphate and a wetting agent, and its concentration is 25g/L. , 30g/L, 50g/L and 5mg/L, the temperature of the roughening solution was 35°C, and the treatment time was 45 seconds.

Example 4

Prepare chemically pure copper pyrophosphate, potassium pyrophosphate and ammonium citrate with pure water according to the concentration of 100g/L, 350g/L and 25g/L respectively, add 8mg/l sodium mercaptoimidazole propanesulfonate, alcohol thiopropanesulfonic acid Sodium 10mg/l and sodium dodecylbenzene sulfonate 15mg/l as additives, after 5 micron, 1 micron and 0.5 micron multi-stage filtration, at a temperature of 55 ℃, a layer thickness of 18 micron copper foil smooth electrodeposition A zinc layer with a thickness of 0.01-0.05 microns was used as the isolation layer, and an ultra-thin copper foil layer with a thickness of 2.5 microns was electrodeposited on the isolation layer with a titanium anode and a current density of 220 A/dm ² .

The carrier copper foil is chemically roughened in a roughening solution prepared with pure water to increase the specific surface area of the ultra-thin and super-strong copper foil. The roughening solution is composed of sulfuric acid, hydrogen peroxide, trisodium phosphate and a wetting agent, and its concentration is 25/L. , 30g/L, 50g/L and 5mg/L, the temperature of the roughening solution was 35°C, and the treatment time was 45 seconds.

Example 5

The concentrations of copper pyrophosphate, potassium pyrophosphate and ammonium citrate in the electrodeposition solution are respectively 120g/L, 380g/L and 35g/L, and 5mg/l of thiazolidinethione, sodium 3-mercapto-1-propane sulfonate are added. 8mg/l and polyethylene glycol 10mg/l additives, after 5 micron, 1 micron and 0.5 micron multi-stage filtration, at a temperature of 55 ℃, a layer of thickness of 0.01-0.05 micron was deposited on 18 micron copper foil smooth surface. The zinc layer was used as an isolation layer, and a titanium anode was used with a current density of 250 A/dm ² , and a copper foil layer with a thickness of 2.5 microns was electrodeposited on the isolation layer.

The carrier copper foil is chemically roughened in the roughening solution prepared with pure water. The roughening solution is sulfuric acid, hydrogen peroxide, trisodium phosphate and the concentration of the wetting agent are 25/L, 30g/L, 50g/L and 5mg/L respectively. L, the temperature of the roughening solution was 35°C, and the treatment time was 45 seconds.

Example 6

The concentrations of copper pyrophosphate, potassium pyrophosphate, and ammonium citrate in the electrodeposition solution were 120g/L, 380g/L, and 35g/L, respectively, and 5mg/L of thiazolidinethione and sodium 3-mercapto-1-propanesulfonate were added. 8mg/l and polyethylene glycol 10mg/l additives, after 5 micron, 1 micron and 0.5 micron multi-stage filtration, at a temperature of 55 ℃, a layer of thickness of 0.01-0.05 micron was electrodeposited on 18 micron copper foil. The zinc layer was used as an isolation layer, and a titanium anode was used with a current density of 250 A/dm ² , and a copper foil layer with a thickness of 2.5 microns was electrodeposited on the isolation layer.

The carrier copper foil is chemically roughened in the roughening solution prepared with pure water. The roughening solution is sulfuric acid, hydrogen peroxide, trisodium phosphate and the concentration of wetting agent are 35/L, 40g/L, 60g/L and 10mg/L respectively. L, the temperature of the roughening solution was 35°C, and the treatment time was 38 seconds.

The properties of the above specific examples 1-6 ultra-thin and high-strength electronic copper foils are shown in Table 1. The tensile strength is greater than 60-80Kg/mm ² , the elongation is greater than 3.0%, and the peel strength is greater than or equal to 0.7N/mm .

Table 1 Ultra-thin high-strength electronic copper foil

The peel strength of the ultra-thin high-strength electronic copper foil is related to the insulating substrate, and the above examples are the FR-4 test results. For the same F-4 substrate, the peel strength data will be slightly different due to the different resin formulations of various PCB manufacturers.

The ultra-thin and high-strength electronic copper foil provided by the present invention is provided to PCB or CCL users in rolls, and can be directly cut into the required size and laminated according to normal copper foil and insulating material. After pressing, the ultra-thin high-strength copper foil and the insulating substrate are firmly bonded together, and the zinc layer between the ultra-thin high-strength copper foil and the carrier is heated and diffused during pressing, so that the The bonding force is reduced, and the ultra-thin high-strength copper foil and the carrier are easily separated by mechanical force.

To sum up, with the help of the above technical solutions of the present invention, 18-35 micron copper foil is used as the cathode carrier, and electrochemical deposition is carried out on the surface of the carrier in the mixed solution of copper pyrophosphate, potassium pyrophosphate and additives to form a thickness of 2.5- The ultra-thin copper foil layer of 5 microns can increase the specific surface area after micro-roughening; the peeling resistance can be improved by coating the organic layer and the oxidation of the foil can be effectively prevented; by preparing the isolation layer on the carrier, the ultra-thin copper foil can be The bonding force between the foil and the carrier is reduced, and the two are easily separated by mechanical force; the process is simple in steps, can be continuously produced, and is an efficient production process of high-strength ultra-thin copper foil for the carrier.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the present invention. within the scope of protection.

Claims

A method for producing ultra-thin high-strength electronic copper foil, comprising the following steps:

S1, prepare electrolyte with copper pyrophosphate, potassium pyrophosphate and ammonium citrate;

S2. Add mixed additives and pass through multi-stage filtration;

S3. Use a copper foil with a thickness of 18-35 microns as a cathode carrier, and use any known method to make an isolation layer on the cathode carrier;

S4, adding the cathode carrier with the isolation layer to the solution of step S2, and electrodepositing an ultra-thin copper foil layer with a thickness of 2.5-5 microns at a current density of 150-500A /dm to form a carrier copper foil;

S5, use a roughening solution composed of sulfuric acid, hydrogen peroxide, trisodium phosphate and a wetting agent to chemically micro-roughen the rough surface of the carrier copper foil;

S6. After the rough surface of the carrier copper foil is chemically micro-roughened, it is coated with an organic film to form an ultra-thin and high-strength electronic copper foil.
The method for producing an ultra-thin high-strength electronic copper foil according to claim 1, wherein the mixed additive in step S2 comprises A agent, B agent, C agent and chloride ions, and the A agent is at least Contains one of thiazolidinethione, aliphatic amine ethoxy sulfonate, sodium mercaptoimidazole propanesulfonate and azozine dye, and the B agent contains sodium polydithiodipropane sulfonate, alcohol thiopropane A kind of in sodium sulfonate, sodium dimethylformamide base sulfonate and thiimidyl dithiopropane sulfonic acid, and described C agent is a kind of in polyethylene glycol and sodium dodecyl benzene sulfonate. kind.
The method for producing an ultra-thin high-strength electronic copper foil according to claim 1, wherein the concentrations of the copper pyrophosphate, potassium pyrophosphate and ammonium citrate are respectively 80-120g/L, 300-400g /L and 15-35g/L.
The method for producing an ultra-thin high-strength electronic copper foil according to claim 2, wherein the concentrations of the A agent, the B agent and the C agent are respectively 3-50mg/L, 3-80mg/L and 1-20mg/L.
The method for producing an ultra-thin high-strength electronic copper foil according to claim 1, wherein the concentrations of sulfuric acid, hydrogen peroxide, trisodium phosphate and wetting agent in the roughening solution are respectively 25-55g/L, 30-60g/L, 50-80g/L and 5-25mg/L.
The method for producing an ultra-thin and high-strength electronic copper foil according to claim 1, wherein the temperature of the roughening solution is 35°C, and the chemical micro-roughening treatment time is 38-55 seconds.
The method for producing an ultra-thin high-strength electronic copper foil according to claim 1, wherein the organic film is a sprayed aqueous solution of 3-glycidyloxypropyltrimethoxysilane.
The method for producing an ultra-thin high-strength electronic copper foil according to claim 1, wherein the isolation layer has a thickness of 0.05-0.1 microns.
An ultra-thin high-strength electronic copper foil, characterized in that it is prepared by the production method according to any one of claims 1-8, comprising a carrier (1), and an isolation layer (1) is provided on the carrier (1). 2), an ultra-thin copper foil (3) is arranged on the set isolation layer (2), and a roughened layer and an organic layer (4) are arranged on the ultra-thin copper foil (3); the ultra-thin high-strength electronic The tensile strength of the copper foil is greater than 60-80Kg/mm 2 , the elongation is greater than 3.0%, and the peel strength is greater than or equal to 0.7N/mm.