TWI410529B - Electrolyte and copper foil fabrication method utilizing the same - Google Patents

Abstract

An electrolyte is provided. The electrolyte includes sulfuric acid, copper sulfate, a sulfur-containing compound, a polyether compound and a quinone compound having formula (I): wherein A is oxygen, sulfur or nitrogen bonded with a hydrogen, B is nitrogen or carbon bonded with a hydrogen, and R1-R9, independently, are hydrogen, C1-6 alkyl, amine or alkyl-substituted amine. The invention also provides a copper foil fabrication method utilizing the electrolyte.

Description

Electrolyte and method for producing copper foil using the same

The present invention relates to an electrolyte, and more particularly to an electrolyte containing a quinone compound and a method of producing a copper foil using the electrolyte.

The copper foil is a basic raw material for the electronics industry, and the copper foil raw foil produced by the electrolytic method is subjected to subsequent subsequent treatment, and can be applied to, for example, a lithium battery cathode current collector plate and an integrated circuit (IC). Board, printed circuit board (PCB) or plasma display (PDP) electromagnetic shielding. With the evolution of the functions of electronic products, the industry's demand for the performance of copper foil products is also increasing. For example, copper foil is the constituent material of the conductive lines on the printed circuit board, and is the main path for signal transmission between components. In the trend of high frequency, portability and thinning, high-performance electrolytic copper foil with fine line, low surface roughness, high strength, high ductility and thinner is required to meet the needs of practical applications. .

At present, the copper foil related industry's classification of copper foil roughness is based on the Rz value (ten point average roughness value, ISO 1994). Roughness Rz value above 5μm is STD (standard) grade, roughness Rz value is between 3~5μm is VLP (very low profile) grade, and roughness Rz value less than 3μm is classified as ULP (ultra) Low profile), in which the ULP grade copper foil is the most suitable for the thinning trend of electronic products, it has become the consistent pursuit of the copper foil industry.

In order to reduce the roughness of the surface of electrolytic copper foil, the current method in the industry The additive is added to the acidic copper sulfate solution, and the surface roughness of the copper foil is reduced by adjusting the type and concentration of the additive. For example, the purpose of reducing the surface roughness of the copper foil by suppressing the generation of the columnar crystal structure of the copper foil is to reduce the chloride ion concentration in the plating solution to less than 1 ppm or less, for example, to reduce the chloride ion concentration in the plating solution to less than 1 ppm. . However, it is not easy to maintain the chloride ion concentration below 1 ppm due to the limitation of chloride ions which are easily stored in the raw materials and process environment of the copper plating solution, resulting in poor process stability. In addition, reducing the concentration of chloride ions in the plating solution will also increase the copper plating voltage by reducing the associated depolarization effect, resulting in an increase in energy consumption. Therefore, most of the current electrolytic copper foil manufacturers still use a high chlorine process (ie, a chloride ion concentration of 30 ppm or more).

Further, in order to suppress the phenomenon of discharge at the tip end of the electrode surface, there is also a method of reducing the surface roughness of the copper foil by adding a specific adsorption type additive to slow the plating rate of the convex portion of the electrode surface. For example, carboxymethylcellulose disclosed in Japanese Laid-Open Patent Publication No. Hei 10-036991, the sulphur urethane disclosed in Japanese Patent Application Laid-Open No. Hei 10-036991, and No. 5,215,654, and the mixed gelatin, thiourea and polysaccharides disclosed in JP-A 08-058791 are genus This type. Although such a method can reduce the roughness, the effect of the reduction is limited. For a copper foil having a thickness of 10 μm, the roughness Rz value can be reduced only to about 3 μm, and the copper foil is easily caused to be embrittled.

In addition, it has been found that the higher the gloss of the surface of the copper foil, the corresponding surface roughness is reduced. Therefore, the gloss copper plating technique of, for example, US Pat. No. 3,328,237, US Pat. No. 4,336,114 and Japanese Patent Application No. 09-143785, is also an effective reduction of copper foil. Method of surface roughness. Although this countermeasure scheme has good suppression The effect of roughness, but the conventional gloss copper plating technology needs to be low temperature and low current density to obtain copper foil with lower roughness, compared with the high temperature and high current density operating conditions commonly used by electrolytic copper foil manufacturers. The violations are not able to meet the needs of the industry and still need further improvement.

Therefore, there is an urgent need in the industry to develop a process technology that can achieve ULP grade copper foil and can be applied to the operating conditions of today's electrolytic copper foil industry.

An embodiment of the present invention provides an electrolyte comprising: sulfuric acid; copper sulfate; a sulfur-containing compound; a polyether compound; and a terpenoid compound having the following chemical formula (I):

Wherein A is composed of oxygen, sulfur or N having a hydrogen atom ligand structure; B is composed of nitrogen or a carbon having a hydrogen atom ligand; and R1 to R9 are independently hydrogen and have a carbon number of 1 An alkyl group of ~6, an amine group or an amine group having an alkyl substituent. The present invention further provides a method of producing a copper foil using the electrolyte.

An embodiment of the present invention provides a method of manufacturing a copper foil, comprising: providing a cathode and an anode; providing an electrolyte solution; and applying a current to the cathode and the anode to perform a copper foil process.

The above described objects, features and advantages of the present invention will become more apparent and understood.

An embodiment of the present invention provides an electrolyte comprising sulfuric acid, copper sulfate, a sulfur-containing compound, a polyether compound, and an anthraquinone compound having the following chemical formula (I):

In the chemical formula (I), A is composed of oxygen, sulfur or N having a hydrogen atom ligand structure; B is composed of nitrogen or a carbon having a hydrogen atom ligand; and R1 to R9 are independently It is hydrogen, an alkyl group having 1 to 6 carbon atoms, an amine group or an amine group having an alkyl substituent. The present invention further provides a method of producing a copper foil using the electrolyte.

The above sulfur-containing compound may be sodium bis(sodium sulfopropyldisulfide, SPS). The polyether compound can be polyethylene glycol or polypropylene glycol. In the chemical formula (I), A is composed of oxygen, sulfur or N having a hydrogen atom ligand structure; B is composed of nitrogen or a carbon having a hydrogen atom ligand; and R1 to R9 are independently It is hydrogen, an alkyl group having 1 to 6 carbon atoms, an amine group or an amine group having an alkyl substituent. The above terpenoids can be

The electrolyte of the present invention further comprises the addition of chloride ions having a concentration of between 30 and 100 ppm.

One embodiment of the present invention provides a method of manufacturing a copper foil comprising the following steps. First, a cathode and an anode are provided. Next, an electrolyte solution as described above is provided. Thereafter, a current is applied to the cathode and the anode to perform a copper foil process.

The copper foil process has a current density of 50 to 70 Amp/dm ² and a temperature of 50 to 70 ° C.

Referring to Figure 1, an embodiment of the present invention, an apparatus and a step for manufacturing an electrolytic copper foil are illustrated. The apparatus for producing an electrolytic copper foil includes a cathode 20, an anode 10, and an electrolyte 30. The cathode 20 is a rotatable wheel cathode and may be made of titanium or stainless steel. The anode 10 is concentric with the cathode 20 and may be made of lead or a dimensionally stable anode. The electrolyte 30 is passed between the cathode 20 and the anode 10 and may include copper sulfate and additions such as sulfur compounds, polyether compounds, and terpenoids. Agent.

The steps of producing an electrolytic copper foil of the present invention are as follows. First, a current is passed between the anode 10 and the cathode 20 to deposit copper on the surface of the cathode 20 to form a copper foil green foil 100. Thereafter, the copper foil green foil 100 is continuously formed by the rotation of the cathode 20 and peeled off.

[Examples] [Example 1] Preparation of electrolytic copper foil of the invention (1)

First, an electrolyte is introduced between an anode and a cathode. The electrolyte contains copper at a concentration of 60 g/L, 60 g/L sulfuric acid, 36 ppm chloride ion, 400 ppm polyethylene glycol (PEG) (Mw: 4000), and 2 ppm sodium polydithiodipropane sulfonate (SPS). And 3ppm pyronin Y . Thereafter, the electrolytic solution temperature was adjusted to 50 ° C, the current density was 60 Amp/dm ² , and the electrolytic copper foil process was carried out at an electrolyte flow rate of 125 cm/sec to form a copper foil green foil having a thickness of about 10 μm.

[Example 2] Preparation of electrolytic copper foil of the invention (2)

First, an electrolyte is introduced between an anode and a cathode. This electrolyte contains copper at a concentration of 60 g/L, 60 g/L of sulfuric acid, 36 ppm of chloride ion, 400 ppm of polyethylene glycol (PEG) (Mw: 4000), and 3 ppm of sodium polydithiodipropane sulfonate (SPS). And 3ppm pyronin Y . Thereafter, the electrolytic solution temperature was adjusted to 50 ° C, the current density was 60 Amp/dm ² , and the electrolytic copper foil process was carried out at an electrolyte flow rate of 125 cm/sec to form a copper foil green foil having a thickness of about 10 μm.

[Example 3] Preparation of electrolytic copper foil of the invention (3)

First, an electrolyte is introduced between an anode and a cathode. This electrolyte contains copper at a concentration of 60 g/L, 60 g/L sulfuric acid, 36 ppm chloride ion, 400 ppm polyethylene glycol (PEG) (Mw: 4000), and 4 ppm sodium polydithiodipropane sulfonate (SPS). And 3ppm pyronin Y . Thereafter, the electrolytic solution temperature was adjusted to 50 ° C, the current density was 70 Amp/dm ² , and the electrolytic copper foil process was carried out at an electrolyte flow rate of 125 cm/sec to form a copper foil green foil having a thickness of about 10 μm.

[Embodiment 4] Preparation of electrolytic copper foil of the invention (4)

First, an electrolyte is introduced between an anode and a cathode. The electrolyte contains copper at a concentration of 60 g/L, 60 g/L sulfuric acid, 36 ppm chloride ion, 400 ppm polyethylene glycol (PEG) (Mw: 4000), and 2 ppm sodium polydithiodipropane sulfonate (SPS). And 10ppm of thionin . Thereafter, the electrolytic solution temperature was adjusted to 50 ° C, the current density was 50 Amp/dm ² , and the electrolytic copper foil process was carried out at an electrolyte flow rate of 125 cm/sec to form a copper foil green foil having a thickness of about 10 μm.

[Comparative Example 1] Conventional Electrolytic Copper Foil Preparation (1)

First, an electrolyte is introduced between an anode and a cathode. This electrolyte contains copper at a concentration of 60 g/L, 60 g/L sulfuric acid, 36 ppm chloride ion, 400 ppm polyethylene glycol (PEG) (Mw: 4000), and 2 ppm sodium polydithiodipropane sulfonate (SPS). And 3ppm of ethyl violet . Thereafter, the electrolytic solution temperature was adjusted to 50 ° C, the current density was 50 Amp/dm ² , and the electrolytic copper foil process was carried out at an electrolyte flow rate of 125 cm/sec to form a copper foil green foil having a thickness of about 10 μm.

[Comparative Example 2] Conventional Electrolytic Copper Foil Preparation (2)

First, an electrolyte is introduced between an anode and a cathode. The electrolyte contains copper at a concentration of 60 g/L, 60 g/L sulfuric acid, 36 ppm chloride ion, 400 ppm polyethylene glycol (PEG) (Mw: 4000), and 2 ppm sodium polydithiodipropane sulfonate (SPS). And 3ppm of methyl green . Thereafter, the electrolytic solution temperature was adjusted to 50 ° C, the current density was 50 Amp/dm ² , and the electrolytic copper foil process was carried out at an electrolyte flow rate of 125 cm/sec to form a copper foil green foil having a thickness of about 10 μm.

Table 1 shows the working conditions for preparing the electroplated copper foils of Examples 1 to 4 and Comparative Examples 1 and 2, including temperature, current density, electrolyte composition, and electrolyte flow rate. Table 2 shows the physical property test results of the copper foil raw foil samples prepared in Examples 1 to 4 and Comparative Examples 1 and 2, including tensile strength, elongation, and roughness values of the copper foil on the electrolyte side and the cathode side. .

Remarks (please refer to Figure 1): Roughness of copper foil on the electrolyte side Rz-MS value is the ten point average roughness value of the copper foil green foil on the electrolyte side 101; the roughness of the copper foil on the cathode side Rz- SS value is copper foil foil The ten point average roughness value of the cathode side 102; the roughness Ra-MS value of the copper foil on the electrolyte side is the average roughness value of the copper foil green foil on the electrolyte side 101; the roughness of the copper foil on the cathode side Ra- The SS value is the average roughness value of the copper foil green foil on the cathode side 102.

It can be seen from Table 1 and Table 2 that the electrolytic copper foil prepared by the invention under the working conditions of temperature above 50 ° C and current density above 50 Amp/dm ² has a roughness not only up to ULP grade (copper foil foil) The roughness Rz-MS value on the electrolyte side is even lower than 1 μm), and the roughness Rz-MS value of the copper foil green foil on the electrolyte side is lower than the roughness Rz-SS value corresponding to the cathode side. . In addition, the electrolytic copper foil prepared by the invention has good tensile strength and elongation at the same time, and can meet the quality specifications of the currently commercially available electrolytic copper foil for COF use.

The invention adds an antimony compound having the structure of the formula (I) as an additive to the electrolyte, and can be applied to the working conditions of the high temperature and high current density of the electroplated copper foil manufacturer without changing the process equipment. In addition, the electrolytic copper foil process of the present invention can be implemented in a high chlorine process (above 30 ppm), and overcomes the conventional problem of difficulty in controlling the concentration of low chloride ions.

While the present invention has been described in its preferred embodiments, the present invention is not intended to limit the invention, and the invention may be modified and retouched without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application attached.

10‧‧‧Anode

20‧‧‧ cathode

30‧‧‧ electrolyte

100‧‧‧copper foil foil

101‧‧‧ Copper foil foil on the surface of the electrolyte side

102‧‧‧The surface of the foil foil on the cathode side

1 is an embodiment of the present invention, an apparatus and a step for manufacturing an electrolytic copper foil.

10‧‧‧Anode

20‧‧‧ cathode

30‧‧‧ electrolyte

100‧‧‧copper foil foil

101‧‧‧ Copper foil foil on the surface of the electrolyte side

102‧‧‧The surface of the foil foil on the cathode side

Claims (9)

An electrolyte comprising: sulfuric acid; copper sulfate; a sulfur-containing compound; a polyether compound; and an anthraquinone compound having the following chemical formula (I): Wherein A is composed of oxygen, sulfur or N having a hydrogen atom ligand structure; B is composed of nitrogen or a carbon having a hydrogen atom ligand; and R1 to R9 are independently hydrogen and have a carbon number of 1 An alkyl group of ~6, an amine group or an amine group having an alkyl substituent. The electrolyte according to claim 1, wherein the sulfur-containing compound is sodium bis(sodium sulfopropyldisulfide, SPS). The electrolyte according to claim 1, wherein the polyether compound is polyethylene glycol or polypropylene glycol. The electrolyte of claim 1, wherein the hydrazine compound is , , , or . For example, the electrolyte described in claim 1 further includes chloride ions. The electrolyte of claim 5, wherein the concentration of the chloride ion is between 30 and 100 ppm. A method for producing a copper foil, comprising: providing a cathode and an anode; providing an electrolyte as described in claim 1; and applying a current to the cathode and the anode to perform a copper foil process. The method for producing a copper foil according to claim 7, wherein the copper foil process has a current density of 50 to 70 Amp/dm ² . The method for producing a copper foil according to claim 7, wherein the copper foil process has a temperature of 50 to 70 °C.