KR20110071434A - Electrolytic copper foil improved in structure of surface treatment layer and method for producing the same, and copper clad laminate and printed circuit board having the same - Google Patents

Abstract

PURPOSE: An electrolytic copper foil with improved structure of surface treatment layer, a manufacturing method thereof, a copper clad laminate and a printed circuit board are provided to improve heat resistance due to an optimization of concentration of barrier element, and to prevent an etchant from penetrating on the edge area of pattern. CONSTITUTION: The electrolytic copper foil is composed of a copper film(100); and a surface processing layer(101). The surface processing layer has a plurality of copper nodules and is formed in the surface of the copper film. The rate of thickness of the surface processing layer takes 5-30% as to the one adding the copper film and the surface processing layer. The rate of the multi nodule among copper nodules is less than 10%. The surface processing layer includes a plurality of barrier elements more attached on the copper nodule. The electrodeposition amount of the barrier element is 0.02~1.00g per 1m^2. The gravimetric anomaly of the electrodeposited copper foil is below 2g /m^2.

Description

Electrolytic copper foil improved in structure of surface treatment layer and method for producing the same, and copper clad laminate and printed circuit board having the same }

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrolytic copper foil, and more particularly, to an electrolytic copper foil having excellent etching and peel strength characteristics, a method of manufacturing the same, and a copper clad laminate and a printed circuit board.

Electrolytic copper foil, which is a basic material used in the manufacture of printed circuit boards, is manufactured through the electroplating process, which manufactures copper foils, and the post-treatment process that performs nodule treatment, chemical treatment, heat treatment, and antirust treatment on copper foils. Are manufactured.

The copper foil prepared by the usual milling process is peeled from the cathode drum of the mill and is placed on the other side of the relatively low gloss surface (S side: Shiny side) and the gloss side (S side) and has a relatively high roughness. Matte side (M side) is included.

The copper foil is subjected to a surface treatment to form a copper nodule and a barrier in a post-treatment process, thereby giving physical and chemical properties suitable for a printed circuit board.

By the post-treatment process, a copper nodule layer is formed on the mat surface (M surface) of the copper foil, and a barrier layer, which is a plating layer such as nickel (Ni) and chromium (Cr), is formed on the copper nodule layer to provide heat resistance, hydrochloric acid resistance, and Oxidative properties and the like are imparted. On the barrier layer, a silane coupling agent is further coated to improve the adhesion with the resin film adhered to the copper foil.

Since the main physical and chemical properties of the electrolytic copper foil are determined by the structure of the surface treatment layer, when the post-treatment process is not performed properly, the adhesion reliability between the copper foil and the resin film is poor and the etching, peeling strength, flex resistance, and the like deteriorate. May occur.

In particular, recently, electrolytic copper foil is widely used as a material of flexible copper clad laminate (FCCL) for flexible printed circuit boards (FPC), which is applied to curved portions of portable electronic devices, to prevent cracks or disconnection of circuit patterns. Copper foil excellent in etching properties and peel strength properties should be provided.

The present invention has been made in view of the above, and the present invention provides an electrolytic copper foil, a method of manufacturing the same, and a copper clad laminate and a printed circuit board having improved etching and peel strength characteristics by optimizing the proportion of the surface treatment layer in the copper foil. There is a purpose.

Another object of the present invention is to provide an electrolytic copper foil having improved structure of a copper nodule or barrier forming a surface treatment layer, a method of manufacturing the same, and a copper clad laminate and a printed circuit board.

The object of the present invention is not limited to the above-described problem, and other technical problems not mentioned will be clearly understood by the embodiments of the present invention.

Electrolytic copper foil according to the present invention to achieve the above object is copper foil; And a surface treatment layer formed on the surface of the copper foil to include a plurality of copper nodules, wherein the ratio of the thickness of the surface treatment layer to the total thickness of the copper foil and the surface treatment layer is 5 to 30%. It features.

It is preferable that the ratio of the multi-nodules in the said copper nodules is less than 10%.

The surface treatment layer further includes a plurality of barrier elements electrodeposited on the copper nodule, the electrodeposition amount of the barrier element is preferably 0.02 ~ 1.00g per m 2.

It is preferable that the weight deviation of the said electrolytic copper foil is 2 g / m <2> or less.

It is preferable that the surface roughness Rz of the surface treatment layer located in the mat surface (M surface) side of the said copper foil is 0.5-3.5 micrometers.

It is preferable that the total thickness which combined the said copper foil and the surface treatment layer is 5-70 micrometers.

According to another aspect of the present invention, a copper foil and a surface treatment layer formed on the surface of the copper foil to include a plurality of copper nodules, the surface treatment layer for the total thickness of the copper foil and the surface treatment layer combined Electrolytic copper foil having a thickness ratio of 5 to 30%; And a polyimide (PI) film attached to the surface treatment layer located on the mat surface (M surface) of the copper foil.

According to another aspect of the invention, the copper foil and the surface treatment layer formed on the surface of the copper foil to include a plurality of copper nodules; and the surface for the total thickness of the combined copper foil and the surface treatment layer Electrolytic copper foil whose ratio of the thickness of the treated layer is 5 to 30%; And a copper-clad laminate comprising a polyimide (PI) film attached to a surface treatment layer positioned on a mat surface (M surface) of the copper foil.

According to still another aspect of the present invention, there is provided a manufacturing process of manufacturing a copper foil by an electroplating method, and a surface treatment process of forming a surface treatment layer including a copper nodule on a mat surface (M surface) of the copper foil. A method for producing an electrolytic copper foil is provided, wherein the surface treatment layer is formed such that the ratio of the thickness of the surface treatment layer to the total thickness of the copper foil and the surface treatment layer is 5 to 30%.

The electrolytic copper foil according to the present invention has the advantage that the peel strength property is improved by the ratio of the optimized surface treatment layer, so that the adhesive strength with the resin is excellent, the bending resistance is excellent, and the residual after the etching for the circuit pattern formation does not occur.

In addition, by optimizing the concentration of the barrier element, the heat resistance is excellent, and the phenomenon that the etching liquid penetrates into the edge portion of the pattern during the etching operation can be prevented.

Therefore, when the electrolytic copper foil according to the present invention is applied to FPC, FCCL, or Chip On Film (COF), it is possible to effectively prevent the occurrence of cracks or disconnection of the flexible circuit pattern.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, terms or words used in the specification and claims should not be construed as having a conventional or dictionary meaning, and the inventors should properly explain the concept of terms in order to best explain their own invention. Based on the principle that can be defined, it should be interpreted as meaning and concept corresponding to the technical idea of the present invention. Therefore, the embodiments described in the specification and the drawings shown in the drawings are only the most preferred embodiment of the present invention and do not represent all of the technical idea of the present invention, various modifications that can be replaced at the time of the present application It should be understood that there may be equivalents and variations.

First, in FIG. 1, the structure of the foil manufacturing apparatus for manufacture of the copper raw foil used as the base of an electrolytic copper foil is shown.

Referring to FIG. 1, the milling device includes a container C to which the electrolyte solution 10 is continuously supplied, a negative electrode drum 20 rotatably installed in the container C, and a drum 20 in the container C. Referring to FIG. An anode 30 is installed spaced apart from the.

During the manufacturing process of manufacturing the copper foil 100, the rotating drum 20 rotates in the direction of the arrow, and the drum 20 and the anode 30 are supplied with electric power, and the electrode flows through the electrolytic solution 10 for electrodeposition. The process goes on. The copper foil 100 electrodeposited on the drum 2 surface is taken up by the guide roll 50.

The electrolyte solution 10 is composed of copper sulfate as a main component, and includes various additives such as gelatin, HEC, sulfide compounds, nitrides, and the like.

DC power is supplied between the drum 20 and the anode 30 at a current density of 10 to 80 ASD, and thus copper is electrodeposited on the drum 20 to produce a copper foil 100.

The copper foil 100 thus prepared is peeled off the surface of the drum 20 to have a relatively low gloss surface (S-side: Shiny Side) and a mat having a relatively high roughness on the other side of the gloss-side (S-side). It includes the side (M side: Matte Side).

After the production of the copper foil 100 is completed, a surface treatment step of forming a copper nodule on the mat surface (M surface) of the copper foil and electrodepositing a barrier element for imparting chemical resistance, heat resistance, and rust resistance is performed. .

In the surface treatment step, the copper foil is passed through a copper plating bath to form a copper nodule on the mat surface (M surface) of the copper foil, followed by electrodeposition on the copper nodule. At this time, by adjusting factors such as the thickness ratio of the surface treatment layer, the structure of the copper nodule, and the electrodeposition amount of the barrier element as described below, an electrolytic copper foil having excellent etching properties and peel strength characteristics and the like can be produced.

FIG. 2 is a SEM (scanning electron microscope) photograph observing the cross-sectional configuration of an electrolytic copper foil having a surface treatment layer 101 formed on a mat surface (M surface) of a copper foil 100 by a surface treatment process.

Referring to FIG. 2, in the electrolytic copper foil, the thickness ratio of the surface treatment layer 101 is configured to satisfy 5 to 30%. The thickness ratio of the surface treatment layer 101 is defined as a percentage of the thickness of the surface treatment layer 101 in the total thickness of the sum of the thickness of the copper foil 100 and the thickness of the surface treatment layer 101.

When the thickness ratio of the surface treatment layer 101 is less than 5%, the peeling strength between the resin film and the electrolytic copper foil may not be sufficiently secured when the resin film such as polyimide (PI) or flame retardant (FR) -4 is adhered. If the thickness ratio of the layer 101 exceeds 30%, residual after etching for the formation of the circuit pattern occurs.

Preferably, the total thickness of the copper foil 100 and the surface treatment layer 101 is determined to be 5 to 70 μm.

Among the copper nodules included in the surface treatment layer 101, the ratio of the multinodules is preferably less than 10%. As shown in FIG. 3, the multi-nodule includes a support nodule formed on the copper foil 100 (see dashed line marking) and a micronodal attached to the distal end of the support nodule (see dashed line display). It is defined as a nodule having two or more. Referring to FIG. 4, the fine nodule 103 has to satisfy a condition in which the maximum width W2 is 0.5 μm or more and is relatively small in size compared to the maximum width W1 of the support module 102.

The ratio of multinodules In the case of 10% or more, after-etch residues for the formation of the circuit pattern are generated.

The surface treatment layer 101 includes a plurality of barrier elements electrodeposited on the copper nodule. Here, the barrier element is vanadium (V), chromium (Cr), molybdenum (Mo), silicon (Si), iron (Fe), nickel (Ni), cobalt (Co), zinc (Zn), carbon (C) , Monoliths, alloys or compounds of phosphorus (P) are employed.

It is preferable that the electrodeposition amount of a barrier element is 0.02-1.00g per 1m <2> of electrolytic copper foil. When the electrodeposition amount of the barrier element is less than 0.02 g per 1 m 2 of electrolytic copper foil, the heat resistance of the copper foil decreases, and when the amount of the barrier element exceeds 1.00 g per 1 m 2 of electrolytic copper foil, the etching solution penetrates into the edge portion of the pattern in an etching process for forming a circuit pattern. This happens.

In addition, the weight deviation of each point on the electrolytic copper foil is preferably 2 g / m 2 or less in order to further improve the etching resistance, peel strength, flex resistance, and the like, and the surface treatment layer (located on the mat surface (M surface) side of the copper foil 100) It is preferable that the surface roughness Rz of 101) is 0.5-3.5 micrometers.

According to another aspect of the present invention, a copper clad laminate having a structure in which a polyimide resin is attached to a surface treatment layer 101 of an electrolytic copper foil is provided. Polyimide resins have similar thermal expansion coefficients and excellent heat resistance to the stability of IC chip bonding and the like.

According to still another aspect of the present invention, there is provided a printed circuit board including the copper clad laminate and having a predetermined circuit pattern formed on the copper laminate by an etching process.

Table 1 below shows the results of comparing the peel strength (P / S) characteristics and the presence or absence of the characteristics of the electrolytic copper foil according to the embodiments of the present invention (comparative example).

In the examples and comparative examples of the present invention, an electrolytic copper foil having a thickness of 12 μm was prepared, and the peel strength property was measured by applying a 0.8 mm thick FR-4 resin film on the surface treatment layer 101 to JIS C 6481 test and measurement standard. According to the evaluation, the presence or absence of the residual property was evaluated according to the presence or absence of copper residue of 1 μm by observing at 2000 times any four points of the surface where the circuit was not formed after pattern formation using SEM.

Referring to Table 1, in Examples 1 to 4 of the present invention, the thickness (Ttm) ratio of the surface treatment layer 101 satisfies the range of 5 to 30%, and the ratio of the multinodule satisfies the range of less than 10%. As a result, the peeling strength between the FR-4 resin film and the electrolytic copper foil is sufficiently secured to be 1.08 kgf / cm or more, and it can be confirmed that no residual after etching occurs.

On the other hand, Comparative Example 1, although the ratio of the multi-nodule satisfies the range of less than 10% When the thickness (Ttm) ratio of the surface treatment layer 101 is less than 5%, no residual material is generated, but it can be confirmed that the peel strength between the FR-4 resin film and the electrolytic copper foil is not good as 0.92 kgf / cm.

Comparative Example 2 is a case where the ratio of the multinodule satisfies the range of less than 10% but the thickness (Ttm) ratio of the surface treatment layer 101 exceeds 30%, and the peel strength between the FR-4 resin film and the electrolytic copper foil is 1.43. excellent in kgf / cm, It can be seen that after etching, residuals are generated.

In addition, Comparative Example 3 is a case where the thickness (Ttm) ratio of the surface treatment layer 101 satisfies the range of 5 to 30%, but the ratio of the multinodule exceeds 10%, and peeling between the FR-4 resin film and the electrolytic copper foil. Although the strength is excellent at 1.35 kgf / cm, it can be seen that after etching, residual material is generated.

As described above, in the present invention, by improving the ratio of the thickness of the surface treatment layer formed on the electrolytic copper foil, the ratio of the multinodules, and the like, it is possible to provide improved etching properties and peel strength characteristics compared to the prior art.

Although the present invention has been described above by means of limited embodiments and drawings, the present invention is not limited thereto and will be described below by the person skilled in the art to which the present invention pertains. Of course, various modifications and variations are possible within the scope of the claims.

The following drawings, which are attached to this specification, illustrate preferred embodiments of the present invention, and together with the detailed description of the present invention serve to further understand the technical spirit of the present invention, the present invention includes matters described in such drawings. It should not be construed as limited to.

1 is a block diagram of a milling apparatus for producing a copper foil,

2 is a SEM photograph observing the cross-sectional configuration of the electrolytic copper foil according to a preferred embodiment of the present invention,

Figure 3 is a SEM photograph of the multi-nodules formed on the electrolytic copper foil according to a preferred embodiment of the present invention,

4 is a configuration diagram of a multinodule formed on an electrolytic copper foil according to a preferred embodiment of the present invention.

<Description of Major Reference Marks in Drawings>

100: copper foil 101: surface treatment layer

102: support module 103: fine module

Claims (14)

Copper foil; And A surface treatment layer formed on the surface of the copper foil so as to include a plurality of copper nodules; Electrolytic copper foil, characterized in that the ratio of the thickness of the surface treatment layer to the total thickness of the copper foil and the surface treatment layer combined. The method of claim 1, Electrolytic copper foil, characterized in that the proportion of the multi-nodule in the copper nodule is less than 10%. The method of claim 1, The surface treatment layer further includes a plurality of barrier elements electrodeposited on the copper nodule, Electrolytic copper foil, the electrodeposition amount of the barrier element is 0.02 ~ 1.00g per m 2. The method according to any one of claims 1 to 3, The electrolytic copper foil characterized by the weight deviation of copper foil being 2 g / m <2> or less. The method according to any one of claims 1 to 3, Electrolytic copper foil, characterized in that the surface roughness (Rz) of the surface treatment layer located on the mat surface (M surface) side of the copper foil foil is 0.5 ~ 3.5㎛. The method according to any one of claims 1 to 3, Electrolytic copper foil characterized in that the total thickness of the combined copper foil and the surface treatment layer is 5 ~ 70㎛. A copper foil and a surface treatment layer formed on the surface of the copper foil to include a plurality of copper nodules, wherein the ratio of the thickness of the surface treatment layer to the total thickness of the copper foil and the surface treatment layer combined is 5-30%. Phosphorus electrolytic copper foil; And And a polyimide (PI) film attached to the surface treatment layer located on the mat surface (M surface) of the copper foil. And a surface treatment layer formed on the surface of the copper foil so as to include a copper foil and a plurality of copper nodules, wherein the ratio of the thickness of the surface treatment layer to the total thickness of the copper foil and the surface treatment layer is 5 to 30. Electrolytic copper foil which is%; And And a copper-clad laminate comprising a polyimide (PI) film attached to a surface treatment layer positioned on a mat surface (M surface) of the copper foil. A manufacturing process for producing a copper foil by the electroplating method, It includes a surface treatment step of forming a surface treatment layer containing a copper nodule on the mat surface (M surface) of the copper foil, And forming the surface treatment layer such that the ratio of the thickness of the surface treatment layer to the total thickness of the copper foil and the surface treatment layer is 5 to 30%. The method according to claim 9, wherein in the surface treatment step, A method for producing an electrolytic copper foil, wherein the copper nodule is formed such that the proportion of the multinodules is less than 10%. The method according to claim 9, wherein in the surface treatment step, Electrodepositing a plurality of barrier elements on the copper nodules; Electrode copper foil manufacturing method characterized in that the electrodeposition amount of the barrier element is 0.02 ~ 1.00g per 1m2. The method according to claim 9, wherein in the surface treatment step, The said surface treatment layer is formed so that the weight deviation of copper foil may be 2 g / m <2> or less, The manufacturing method of the electrolytic copper foil characterized by the above-mentioned. The method according to claim 9, wherein in the surface treatment step, The surface treatment layer is formed so that the surface roughness (Rz) of the surface treatment layer located on the mat surface (M surface) side of the copper foil is 0.5 to 3.5 μm. The method according to claim 9, wherein in the surface treatment step, A method for producing an electrolytic copper foil, wherein the surface treatment layer is formed such that the total thickness of the copper foil and the surface treatment layer is 5 to 70 μm.

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