KR0156989B1 - High strength electrolytic copper foil - Google Patents

Abstract

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to high strength electrolytic copper foil, and more particularly, to obtaining a high strength electrolytic copper foil by a manufacturing method in which the strength of an electrolytic copper foil for a printed circuit board has a high tensile strength of about 2.5 times at room temperature or high temperature.

The chemical component is composed of copper sulfate concentration including 200g / l to 400g / l and sulfuric acid concentration including 50g / l to 150g / l, and the DC power source for reducing copper includes high frequency components and short duration It consists of a pulse current consisting of a peak current and a base current interrupted, and a current in which a direct current power is combined with the pulse current, and only a pulse current continuously applying a single pulse. By using it, a high-strength electrolytic copper foil can be obtained, and an electrolytic copper foil of ultra-thin film having a thickness of 9 µm can be obtained from a conventional cathode drum.

In order to manufacture such an ultra-thin film, aluminum foil or another electrolytic copper foil is used as a carrier and does not have to be delivered on the carrier, and the loss of the carrier and the new electrolytic facility are not required.

By combining the surface current with pulse current and direct current, electrolytic copper foil with the desired surface roughness can be obtained. The DC current density is 40 to 100 amp / dm ² , and the average surface roughness is slightly lower than the pulse current alone. Mechanical strength is also low.

In this way, the thickness of the electric double layer between the cathode and the electrolyte becomes thinner and the tensile strength is increased by 2.5 times or more, so that it has a high elongation of 25% or more even at a high temperature.

In addition, it is possible to produce an ultra-thin electrolytic copper foil of 9 ㎛ in the conventional cathode drum. On the other hand, aluminum foil or another electrolytic copper foil is not used as a carrier for the manufacture of ultra-thin films, which is a revolutionary invention with the advantages of loss of carrier and no need for new electrolytic facilities.

Description

High strength electrolytic copper foil manufacturing method

Figure 1 (a) is a schematic diagram of the electrolytic method applying a pulse current according to an embodiment of the present invention.

(b), (c) is a schematic diagram of an electrolytic method combining a pulse current and a direct current according to an embodiment of the present invention.

2 is a diagram showing the execution time of each current of the pulse current according to the embodiment of the present invention.

* Explanation of symbols for main parts of the drawings

A: anode voltage generator C: cathode drum

D: DC current supply P: Pulse current supply

ip: peak current ib: base current

tp: time of peak current tb: time of base current

The present invention relates to a high-strength electrolytic copper foil, and more particularly, to a high-strength electrolytic copper foil for producing ultra-thin electrolytic copper foil from a cathode drum by combining a pulse current and a direct current during electrolytic copper foil.

Generally, printed circuits are widely used as precision control circuits of various electric and electronic communication devices such as radios, televisions, computers, telephone exchanges, and wireless transceivers. Recently, the high quality of printed circuit boards is required, and the circuits of the boards have been miniaturized, highly integrated, and miniaturized, thereby increasing the demand for multilayer boards.

Conventional electrolytic copper foil is composed of a cathode drum prepared by reducing copper to a desired thickness and a direct current power source used to reduce the copper ions.

In this configuration, when the copper is reduced by a DC power source, the copper crystals are arranged in the electric field direction of the electrolytic copper foil, and in the case of the electrolytic copper foil, copper was reduced to 18, 35, and 70 μm in thickness to prepare an electrolytic copper foil having a desired thickness.

As such, the conventional electrolytic copper foil cannot be used in a multilayer printed circuit board requiring a more precise high density and high insulation because of its thick thickness. In addition, the roughness of the expression is so high that the surface roughness is significantly high, and the cracks are easily generated in the thermal shock received during the multi-layer molding, and the cracking of the circuit is anticipated. The electrolysis above the carrier requires loss of carrier and new electrolytic equipment.

In addition, the conventional DC power supply cannot increase the strength of the electrolytic copper foil or decrease the surface roughness by increasing the current density required for copper reduction.

Accordingly, an object of the present invention for solving the above problems is a combination of a direct current power supply for reducing copper, a pulse current which is a high-frequency component and a short duration current, and a direct current power supply with the pulse current. Therefore, since a high-strength electrolytic copper foil having a low surface roughness is produced, a high-strength electrolytic copper foil having higher strength and lower surface roughness is provided.

Hereinafter, the configuration of the present invention with reference to the accompanying drawings in detail as follows.

In the present invention, as shown in FIG. 1 (a) (b) (c), a cathode drum C for outputting a cathode voltage cathode to reduce copper ions on a surface thereof has a plurality or a plurality of anode voltages in a predetermined space at a lower end thereof. Arrange the generating plate (A) so as to output the anode anode voltage, connect the pulse current generator (P) for supplying pulse current to the cathode drum (C) and the anode voltage generating plate (P), and the other end. The input terminal is provided with an electrolytic copper foil 10 connected to a DC current supply D for supplying a DC current.

Referring to the effects of the present invention configured as described above in detail.

The present invention is to produce a high-strength electrolytic copper foil by reducing copper ions. Referring to (a), (b), (c) and FIG. 2 of FIG. Chemically fused copper ions are introduced into the inside, and the cathode drum (C) and the anode voltage generating plate (A) inside receive the current from the pulse current supply (P) or the direct current supply (D) to rotate the cathode drum. While reducing the copper ions while producing a high-strength electrolytic copper foil.

Herein, an example of a high strength electrolytic copper foil will be described.

Example 1 (FIG. 1a)

The copper sulfate concentration is 300 g / l, the sulfuric acid concentration is 100 g / l, the temperature of the electrolyte is 60 degrees, and only the pulse current output from the pulse current supply P is used as the power input. The current density and the current density was run time (tp) of the peak current for a 30 amp/dm ² of 200amp / dm ^2, and a base current (ib) of the peak current (ip) is 5 ms, and the execution time of the base current (tb ) Is 50 milliseconds. Here, the peak current density is 100 to 500amp / m ^2, the base current density is 10 to 50 amp/m ^2.

If the peak current density is 100amp / m ² under pulse current effect showed the same result as the direct-current-free, 500amp / m is more than ^divalent copper, and hydrogen is precipitated at the same time the copper is precipitated in powder form can not make copper foil.

In addition, when the base current density is less than 10 amp / m ^2, it is difficult to fix the copper precipitate formed at the peak current, and when it is 50 amp / m ² or more, the pulse effect is inferior, resulting in the same conditions as the direct current.

The peak current time is 5 to 10 milliseconds, and the pre-current time is 20 to 60 milliseconds.

If the peak current time is less than 5 milliseconds, the peak current effect does not appear. If the peak current time is 10 milliseconds or more, the powder phase precipitates and cannot be used as the copper foil.

If the current current time is less than 20 milliseconds, it is difficult to fix the fine copper precipitates. If the base current time is 60 milliseconds or more, the fine copper precipitates grow and the crystal grains due to the pulse current cannot be refined.

Example 2 (FIG. 1b)

As in Example 1, the copper sulfate concentration was 300 g / l, the sulfuric acid concentration was 100 g / l, the temperature of the electrolyte was 60 degrees, and the current density of the peak current ip output from the pulse current supply P was 200 amp. / dm ² and a current density has run time (tp) of the peak current for a 30 amp/dm ² of the base current (ib) is 5 ms, and the execution time (tb) of the base current is equal to 50 milliseconds, a pulse current Apply a current by combining the DC current of the DC current supply (D) and set the DC current density to 50 amp / dm ² .

[Comparative Example]

The copper sulfate concentration is 300 g / l, the sulfuric acid concentration is 100 g / l, and the temperature of the electrolyte is 60 degrees. The power source is DC power and the current density is 50 amp / dm ² .

As described above, the mechanical strength and the average surface roughness are remarkably different as the current required for reducing copper is changed.

Looking at the chart, the copper sulfate concentration and the sulfuric acid concentration are used in the same concentration, and the electrolyte temperature is also the same. These results are obtained by applying the same conditions and classifying the current in the density of each current. The pulse current required to reduce copper by applying current to the anode voltage generating plate (A) and the cathode drum (C) is 55 milliseconds per cycle.

In more detail, instead of a DC power source, a high frequency component is included and a short duration is performed, a pulse current consisting of an intermittent peak current (ip) and a base current (ib), or a combination of the DC power source and the DC power source. By controlling the surface roughness arbitrarily to produce a high-strength electrolytic copper foil having a high intensity and low roughness, it is possible to manufacture even the ultrathin (9 μm) in the conventional cathode drum (C) by receiving such a high strength.

Copper sulfate concentration is 200g / l to 400g / l is preferably 250g / l to 350g / l, sulfuric acid concentration is 50g / l to 150g / l, preferably 70g / l to 100g / l and the temperature of the electrolyte solution is 50 Degrees to 80 degrees. Current density of peak current is 100 to 500 amp / dm The current density of the ground current (ib) is 10 to 50 amp / dm to be. The execution time tp of the peak current is 5 to 10 milliseconds and the execution time tb of the base current is 20 to 60 milliseconds. Therefore, the minimum execution time is 25 milliseconds and the maximum execution time is 70 milliseconds.

The total processing time is proportional to the total current and the thickness of the copper foil. The high-strength electrolytic copper foil with an increase in tensile strength of about 2.5 times can be confirmed by producing an electrolytic copper foil using such a pulse current (P) and comparing it with an electrolytic copper foil manufactured with a conventional direct current. have. In addition, the elongation is about 25% at a high temperature of 180 ℃ room temperature has a high elongation is used as an inner layer printed circuit of a multi-layer substrate. It is possible to manufacture such a special copper foil high current density of pulse current, that is, peak current density of 100 to 500 amp / dm Since the nucleation is large, and the crystal grains become fine, the thickness of the electric double layer between the cathode and the electrolyte becomes thin.

As a result, the thinner electrical double layer reduces resistance and flows of current smoothly, creating the best conditions for printed circuit boards.

Since only a pulse current continuously applying a single pulse is used, a high-strength electrolytic copper foil can be obtained, and an electrolytic copper foil of ultra-thin film having a thickness of 9 µm can be obtained from a conventional cathode drum.

In order to manufacture such an ultra-thin film, aluminum foil or another electrolytic copper foil is used as a carrier and does not have to be delivered on the carrier, and the loss of the carrier and the new electrolytic facility are not required.

By combining the surface current with pulse current and DC current, the surface roughness can be adjusted to obtain an electrolytic copper foil with the desired surface roughness. The average surface roughness is slightly lower than the pulse current alone, and the mechanical strength is also low.

In this way, the thickness of the electric double layer between the cathode and the electrolyte becomes thinner and the tensile strength is increased by 2.5 times or more.

This is made possible by miniaturizing and homogenizing the crystal grains during the pulse current operation.

In addition, an ultra-thin electrolytic copper foil of 9 µm in a conventional cathode drum can be produced. On the other hand, aluminum foil or another electrolytic copper foil is not used as a carrier for the manufacture of ultra-thin films.

Claims (2)

Connects a cathode drum (C) for outputting a cathode voltage cathode to reduce copper ions on the surface, and a pulse current generator (P) for supplying a pulse current to the cathode drum (C) and the anode voltage generator (A) In the electrolytic copper foil 10 having a DC current supply D for supplying a DC current to an input terminal of the other end, a plurality of or a plurality of anode voltage generating plates A are spaced at a lower end of the cathode drum C. ) to place the positive voltage node is connected to the output and to output to the peak current density by 100 to 500amp / dm ² at the current pulse generator (P) and a low base output current density from 10 to 50 amp/dm ^2, the peak current (tp) is executed at 5 to 10 milliseconds, the base current (tb) is executed at 20 to 60 milliseconds, and the DC density output from the DC current supply (D) is 40 to 100 amp / dm ^2. Characterized by producing a copper foil Strength electrolytic copper foil production method. The method of claim 1, wherein the cathode drum (C) forms a copper foil of 9 µm by the pulse current output from the pulse current generator (P).