KR102645171B1 - Flexible copper clad laminate film, method of manufacturing the same, and electronic device including the same - Google Patents

Abstract

A flexible copper foil laminated film, a manufacturing method thereof, and an electrical device comprising the same are disclosed. The flexible copper foil laminated film is polyimide having a thickness of 50 ㎛ or less. write; A tie layer located on at least one side of the polyimide substrate; and a copper layer located on the tie layer, wherein the copper layer includes a copper plating layer having a thickness of 1.0 ㎛ to 10.0 ㎛ on its surface, wherein the copper plating layer has a thickness of 4.4 A/dm ² to 5.2 A/dm. It may contain copper particles grown at a current density of ² and have a tensile strain of 14% to 21%.

Description

Flexible copper clad laminate film, method of manufacturing the same, and electrical device including the same {Flexible copper clad laminate film, method of manufacturing the same, and electronic device including the same}

It relates to a flexible copper foil laminated film, a manufacturing method thereof, and an electrical device containing the same.

Recently, as the growth of the mobile market has accelerated and demand for LCD TV monitors has increased, the development of materials with thinning, miniaturization, weight reduction, durability, and high-definition characteristics has been promoted in fields such as electronic products and semiconductor integrated circuits. Fine patterning, thinning, and durability are increasingly required in the field of flexible copper clad laminated film (FCCL) used in driver integrated circuits (ICs) for LCDs.

In line with this trend, for example, Chip-on-Film (COF) technology is being used. The Chip-on-Film (COF) technology uses a thin film with a very fine pitch, and is a liquid crystal display device for realizing high-definition images using materials such as mobile phones and semiconductor displays. It can be used to drive to increase the number of fires. In addition, this Chip-on-Film (COF) technology enables miniaturization of chip modules and the material is flexible, so it can be folded or rolled. To increase bending resistance, the film is subjected to a high-temperature heat treatment process. It is being carried out. However, through these processes, processing problems such as thermal shock, film folding, curling, or wrinkles may occur in the flexible copper laminated film.

Therefore, there is still a need for a flexible copper clad laminated film to improve bending resistance without performing a heat treatment process, a manufacturing method thereof, and an electric device including the same.

On one side, a flexible copper foil laminated film with improved bending resistance by improving tensile strain and lowering tensile strength is provided.

Another aspect provides a method of manufacturing the flexible copper foil laminated film.

In another aspect, an electric device including the flexible copper foil laminated film is provided.

According to one aspect,

Polyimide with a thickness of 50 ㎛ or less write;

A tie layer located on at least one side of the polyimide substrate; and

It includes a copper layer located on the tie layer,

The copper layer includes a copper plating layer having a thickness of 1.0 ㎛ to 10.0 ㎛ on its surface,

The copper plating layer includes copper particles grown at a current density of 4.4 A/dm ² to 5.2 A/dm ² ,

A flexible copper foil laminated film having a tensile strain of 14% to 21% is provided.

The copper plating layer is formed by using a plurality of plating baths and increasing the current density in the plating bath section after 1/3 of the plurality of total plating tank sections by 2 to 3 times compared to the plating tank section before 1/3. It may be a plating layer.

The copper plating layer may be an electroplating layer formed by applying a current at a rate of 2.2 m/min to 2.5 m/min.

Tensile strength may be 28 MPa to 32.5 MPa.

When measuring MIT at an angle of 135° and a speed of 175 rpm, the number of reciprocating folds until disconnection occurs may be more than 130 times.

According to different aspects,

Polyimide with a thickness of 50 ㎛ or less Preparing a substrate;

Forming a tie layer on at least one side of the polyimide substrate;

forming a copper layer on the tie layer; and

The copper layer includes forming a copper electroplating layer on the surface of the copper layer to produce a flexible copper foil laminated film,

The copper electroplating layer is formed by applying a current at a speed of 2.2 m/min to 2.5 m/min and a current density of 4.4 A/dm ² to 5.2 A/dm ² ,

A method of manufacturing a flexible copper foil laminated film having a tensile strain of 14% to 21% is provided.

The copper electroplating layer may be formed by performing plating at a temperature of 30°C to 34°C.

According to another aspect,

An electric device including the above-described flexible copper foil laminated film is provided.

According to one aspect, the flexible copper foil laminated film can improve bending resistance by improving tensile strain and lowering tensile strength without performing a high temperature heat treatment process.

Figure 1 is a cross-sectional schematic diagram of a flexible copper foil laminated film according to one embodiment.
Figure 2 is a schematic diagram showing the height (h) of the swollen copper plating layer and the radius (r) of the circle of the swollen copper plating layer measured for evaluation of tensile strain and tensile strength in Evaluation Example 1.
Figure 3 shows an example The flexible copper foil laminated film manufactured in step 3 was cut into 80 mm It shows the horizontal (width) and vertical (length) measurements of the optical microscope image and the crack area when it is red.

Hereinafter, a flexible copper clad laminated film, a manufacturing method thereof, and an electric device including the same will be described in detail with reference to examples and drawings of the present invention. These examples are merely presented as examples to explain the present invention in more detail, and it will be apparent to those skilled in the art that the scope of the present invention is not limited by these examples. .

Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as commonly understood by a person skilled in the art to which the present invention pertains. In case of conflict, the present specification, including definitions, will control.

Although methods and materials similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods and materials are described herein.

In this specification, the term "include" means that other components may be further included rather than excluding other components, unless specifically stated to the contrary.

As used herein, the term “and/or” is meant to include any and all combinations of one or more items associated with each other. As used herein, the term “or” means “and/or.” In this specification, the expression “at least one type” or “one or more” in front of components does not mean that the entire list of components can be supplemented and that individual components of the above description can be supplemented.

When a component is referred to herein as being disposed “on” another component, the component may be placed directly on the other component or there may be intervening components between the components. there is. On the other hand, when a component is referred to as being disposed “directly on” another component, intervening components may not be present.

The flexible copper foil laminated film according to one embodiment is polyimide having a thickness of 50 ㎛ or less. write; A tie layer located on at least one side of the polyimide substrate; and a copper layer located on the tie layer, wherein the copper layer includes a copper plating layer having a thickness of 1.0 ㎛ to 10.0 ㎛ on its surface, wherein the copper plating layer has a thickness of 4.4 A/dm ² to 5.2 A/dm. It may contain copper particles grown at a current density of ² and have a tensile strain of 14% to 21%. The copper layer includes a copper seed layer and a copper plating layer.

Figure 1 is a cross-sectional schematic diagram of a flexible copper foil laminated film 10 according to an embodiment.

Referring to Figure 1, the flexible copper foil laminated film 10 according to one embodiment includes a polyimide substrate (1); A tie layer (2) disposed on at least one side of the polyimide substrate (1); A copper seed layer (3) located on the tie layer (2), and a copper plating layer (4) located on the copper seed layer are disposed.

The thickness of the polyimide substrate 1 may be 50 μm or less. The flexible copper clad laminated film 10 according to one embodiment may include an ultra-thin polyimide film in which the thickness of the polyimide substrate 1 may be 40 ㎛ or less, 30 ㎛ or less, 20 ㎛ or less, or 12.5 ㎛ or less. there is. The bending resistance can also be improved in the flexible copper foil laminated film 10 containing such a thin polyimide film.

The tie layer 2 may be a deposited layer containing an alloy containing Ni and Cr. The weight ratio of Ni to Cr in the tie layer 2 may, for example, be 70 to 30, or 75 to 25, or 80 to 20, or 85 to 15, or 90 to 10, or 95 to 5. It could be 96 to 4. The thickness of the deposited layer may be about 40 Å to 500 Å, or about 42 Å to 480 Å, or about 44 Å to 460 Å, or about 45 Å to 450 Å.

The thickness of the copper seed layer 3 can for example be between 0.1 μm and 3.0 μm or between 0.1 μm and 2.6 μm or between 0.1 μm and 2.4 μm or between 0.1 μm and 2.2 μm or between 0.1 μm and 2.0 μm. It may be 0.1 μm to 1.0 μm.

The thickness of the copper plating layer 4 may be 1.0 ㎛ to 10.0 ㎛. For example, the thickness of the copper plating layer 4 may be 1.0 μm to 8.0 μm, or 1.0 μm to 7.0 μm, or 1.0 μm to 6.0 μm, or 1.0 μm to 5.0 μm, or 1.0 μm to 4.0 μm. It may be 1.0 μm to 3.0 μm. The flexible copper foil laminated film 10 according to one embodiment can secure improved bending resistance even when the copper plating layer 4 has a thickness within the above range.

The copper plating layer 4 may include copper particles grown at a current density of 4.4 A/dm ² to 5.2 A/dm ² . The copper plating layer 4 may include copper particles grown by applying two or more types of current densities within this high current density range. The copper plating layer 4 uses a plurality of plating baths and increases the current density in the plating bath section after 1/3 of the plurality of total plating tank sections by 2 to 3 times compared to the plating tank section before 1/3. It may be a formed electroplating layer. Within this high current density range, the thickness is increased by applying a relatively low current density in the plating tank section before 1/3 of the total plating tank sections, and in the plating tank section after 1/3, the current density is 2 to 3 times that of the low current density. By applying a twice as high current density, the grain size can be reduced to 1.5 ㎛ or less, for example, 0.8 ㎛ to 1.2 ㎛ . As a result, not only can the tensile strain of the flexible copper clad laminated film 10 including the copper plating layer 4 be improved and the tensile strength lowered, but also the occurrence of cracks can be significantly reduced when evaluating bending resistance. As a result, the high level of bending resistance required for chip-on-film (COF) technology for thinning and fine patterning on the upper part of the copper plating layer 4 can be secured without performing a heat treatment process. You can.

The copper plating layer 4 may be an electroplating layer formed by applying a current at a rate of 2.2 m/min to 2.5 m/min.

The flexible copper foil laminated film 10 according to one embodiment may have a tensile strain of 14% to 21%.

The flexible copper foil laminated film 10 according to one embodiment may have a tensile strength of 28 MPa to 32.5 MPa.

The flexible copper foil laminated film 10 according to one embodiment may be folded 130 times or more until disconnection occurs when measuring MIT under an angle of 135° and a speed of 175 rpm. For example, the flexible copper clad laminated film 10 according to one embodiment may have a reciprocating folding count of 135 or more, 150 or more, or 180 times until disconnection occurs when measured by MIT at an angle of 135° and a speed of 175 rpm. It can be more than 210 times, it can be more than 240 times, it can be more than 270 times, it can be more than 300 times, it can be more than 330 times, or it can be more than 360 times. The flexible copper foil laminated film 10 according to one embodiment can have significantly improved bending resistance without requiring additional processes such as heat treatment.

The flexible copper foil laminated film 10 according to one embodiment may not include an adhesive layer. The flexible copper foil laminated film 10 can secure a film with improved bending resistance without including an adhesive layer and without processing problems such as folding, curling, or wrinkles of the film.

A protective film (not shown) may be additionally included on the opposite side of the polyimide substrate (1) where the tie layer (2) is located. The protective film may be composed of an acrylic adhesive layer and a polyethylene terephthalate (PET) film. The thickness of the acrylic adhesive layer may be, for example, about 1 to 20 ㎛. For example, the polyethylene terephthalate (PET) film may be about 10 to 100 ㎛.

The acrylic adhesive layer may be a resin layer copolymerized with an acrylic monomer. Examples of the acrylic monomer include acrylic acid alkyl ester monomers such as ethyl acrylate, butylacrylate, amyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, cyclohexyl acrylate, and benzyl acrylate; Methacrylic acid alkyl ester monomers such as butyl methacrylate, 2-ethylhexyl methacrylate, cyclohexyl methacrylate, benzylhexyl methacrylate, cyclohexyl methacrylate, and benzyl methacrylate; monomers containing carboxylic acid groups such as methyl acrylate, methyl methacrylate, vinyl acetate, styrene, acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride, and itaconic acid; Monomers containing hydroxy groups such as 2-hydroxyethyl (meth)acrylate, 4-hydroxybutylacrylate, and 2-hydroxypropyl (meth)acrylate; It may be an amide monomer such as N-methylol acrylamide, acrylamide, methacrylamide, glycidylamide, etc. The acrylic resin can be used alone or in combination with the monomers.

Additionally, examples of additional acrylic monomers include lauryl acrylate, ethoxydiethylene glycol acrylate, methoxytriethylene glycol acrylate, phenoxyethyl acrylate, tetrahydrofuryl acrylate, isobornyl acrylate, and 2-hydroxyethyl. monofunctional acrylate monomers such as acrylate, 2-hydroxypropylacrylate, 2-hydroxy-3-phenoxyacrylate, etc.; Neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol hexaacrylate, trimethylolpropane acrylic acid benzoate Acrylic acid derivative monomers such as multifunctional acrylates, etc.; 2-ethylhexyl methacrylate, n-stearyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxybutyl methacrylate, etc. functional methacrylate monomer; Methacrylic acid derivative monomers such as multifunctional methacrylates such as 1,6-hexanediol dimethacrylate, trimethylolpropane trimethacrylate, and glycerin dimethacrylate; It may be a monomer such as urethane acrylate such as glycerin dimethacrylate hexamethylene diisocyanate and pentaerythritol triacrylate hexamethylene diisocyanate. The acrylic resin can be used alone or in combination with the monomers or oligomers.

Polymerization initiators used with the acrylic resin include azo-based polymerization initiators. The azo-based polymerization initiator can be used without limitation as long as it is an azo-based polymerization initiator used in normal radical polymerization.

Examples of the azo-based polymerization initiator include 2,2'-azobis(isobutyronitrile) (AIBN), 2,2'-azobis(2-methylbutyronitrile) (AMBN), and 2'-azobis( 2,4-dimethylvaleronitrile) (ADMVN), 1,1'-azobis(1-cyclohexanecarbonitrile) (ACHN), dimethyl 2,2'-azobisisobutyrate (MAIB), 4,4' -Azobis(4-cyanovaleric acid) (ACVA), 1,1'-azobis-(1-acetoxy-1-phenylethane), 2,2'-azobis(2-methylbutylamide), 2,2'-azobis(4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis(2-methylamidinopropane) dihydrochloride, 2,2'-azobis[2 -(2-imidazolin-2-yl)propane], 2,2'-azobis[2-methyl-N-(2-hydroxyethyl)propionamide], 2,2'-azobis(2, 4,4-trimethylpentane), 2-cyano-2-propylazoformamide, 2,2'-azobis(N-butyl-2-methylpropionamide), 2,2'-azobis(N-cyclo hexyl-2-methylpropionamide), etc. The azo-based polymerization initiator can be appropriately selected depending on reaction conditions.

In addition to the acrylic adhesive layer, one or more plasticizers selected from the group consisting of phthalate-based, phosphate-based, trimethylate-based, polyester-based, epoxide-based, glycol ester-based, and paraffin-based plasticizers may be included.

The total thickness of the flexible copper foil laminated film 10 may be 60 ㎛ or less. The total thickness of the flexible copper foil laminated film 10 is, for example, 0.1 ㎛ to 60 ㎛, 0.1 ㎛ to 50 ㎛, 0.1 ㎛ to 40 ㎛, 0.1 ㎛ to 30 ㎛, 0.1 ㎛ to 20 ㎛, or 0.1 ㎛ to 20 ㎛. It may be 15 μm.

A method of manufacturing a flexible copper foil laminated film according to another embodiment includes polyimide having a thickness of 50 ㎛ or less. Preparing a substrate; Forming a tie layer on at least one side of the polyimide substrate; forming a copper layer on the tie layer; And forming a copper electroplating layer on the surface of the copper layer to produce a flexible copper foil laminated film, wherein the copper electroplating layer operates at a speed of 2.2 m/min to 2.5 m/min and 4.4 A/dm ² to 4.4 A/dm. It is formed by applying a current at a current density of 5.2 A/dm ² , and the tensile strain may be 14% to 21%. The flexible copper foil laminated film can improve bending resistance by improving tensile strain and lowering tensile strength without performing a high-temperature heat treatment process.

First, polyimide with a thickness of 50 ㎛ or less Prepare the documentation. The polyimide substrate can be subjected to surface treatment such as RF plasma treatment.

Next, a tie layer is formed on at least one side of the polyimide substrate. The tie layer may be an alloy containing Ni and Cr. The weight ratio of Ni to Cr in the tie layer may be, for example, 70 to 30, or 75 to 25, or 80 to 20, or 85 to 15, or 90 to 10, or 95 to 5. It could be 96 to 4. In the step of forming the tie layer, a deposition layer may be formed using a sputtering method. These sputtering methods may include physical vapor deposition (PVD), chemical vapor deposition (CVD), low pressure chemical vapor deposition (LPCVD), or vacuum deposition. The thickness of the tie layer may be about 40 Å to 500 Å, or about 42 Å to 480 Å, or about 44 Å to 460 Å, or about 45 Å to 450 Å.

Next, a copper seed layer is formed on the tie layer. The copper seed layer can also be deposited using the same sputtering method as the tie layer formation. The copper seed layer formed by this sputtering method can maintain the surface roughness of the polyimide substrate. The thickness of the copper seed layer can be, for example, 0.1 μm to 3.0 μm, or 0.1 μm to 2.6 μm, or 0.1 μm to 2.4 μm, or 0.1 μm to 2.2 μm, or 0.1 μm to 2.0 μm. or may be 0.1 ㎛ to 1.0 ㎛.

Next, a copper electroplating layer is formed on the copper seed layer to manufacture a flexible copper foil laminated film. For example, the copper electroplating layer can be formed on one side of the copper seed layer by electroplating with an electrolytic plating solution based on copper sulfate and sulfuric acid. Additionally, additives such as brighteners, levelers, correctors, or emollients may be added to the electrolytic plating solution for productivity and surface uniformity.

The copper electroplating layer has a speed of 2.2 m/min to 2.5 m/min and 4.4 A/dm.² to 5.2 A/dm² It can be formed by applying a current at a current density. The copper electroplating layer is formed by using a plurality of plating baths and increasing the current density in the plating bath section after 1/3 of the plurality of total plating tank sections by 2 to 3 times compared to the plating tank section before 1/3. It can be. For example, the number of plating tanks may be 15 to 21. Within this high current density range, the thickness is increased by applying a relatively low current density in the plating tank section before 1/3 of the total plating tank sections, and in the plating tank section after 1/3, the current density is 2 to 3 times that of the low current density. By applying a twice as high current density, the grain size can be reduced to 1.5 ㎛ or less, for example, 0.8 ㎛ to 1.2 ㎛. As a result, not only can the tensile strain of the flexible copper foil laminated film including the copper plating layer be improved and the tensile strength lowered, but also the occurrence of cracks when evaluating bending resistance can be significantly reduced. As a result, the high level of bending resistance required for chip-on-film (COF) technology for thinning and fine patterning on the top of the copper plating layer can be secured without performing a heat treatment process.

The copper electroplating layer may be formed by performing plating at a temperature of 30°C to 34°C. When plating is performed within this temperature range, the internal stress of the formed copper electroplating layer may be reduced.

Tensile strength may be 28 MPa to 32.5 MPa.

The flexible copper foil laminated film may be folded more than 130 times until disconnection occurs when measured by MIT at an angle of 135° and a speed of 175 rpm. For example, the number of reciprocating folds until disconnection occurs when measuring MIT at an angle of 135° and a speed of 175 rpm may be 135 or more, 150 or more, 180 or more, or 210 or more. or may be more than 240 times, may be more than 270 times, may be more than 300 times, may be more than 330 times, or may be more than 360 times. The flexible copper foil laminated film can have significantly improved bending resistance without requiring additional processes such as heat treatment.

An electrical device according to another embodiment may include the above-described flexible copper foil laminated film.

The electrical device can be used in flexible printed circuit boards (FPCB) and camera coils.

Hereinafter, the configuration of the present invention and its effects will be described in more detail through examples and comparative examples. However, it will be obvious that the present examples are for illustrating the present invention in more detail, and that the scope of the present invention is not limited to these examples.

[Example]

Example 1: Flexible copper foil laminated film

A 12.5 ㎛ thick polyimide film (Kapton 50ENC, manufactured by TDC) was prepared. A protective film (LE951, manufactured by Toyo) with a thickness of approximately 50 μm consisting of an acrylic adhesive layer and a polyethylene terephthalate (PET) film was laminated on one side of the polyimide film. A Ni-Cr alloy tie layer and a Cu seed layer were sequentially formed on the opposite side of the polyimide substrate on which the protective film was laminated by physical vapor deposition (PVD) using a roll-to-roll type sputtering device. At this time, the tie layer was formed to a thickness of about 250 Å with a weight ratio of Ni and Cr of 80:20 (purity: 99.9% or more), and the Cu seed layer was formed with a thickness of about 0.8 ㎛ using 99.995% purity copper. was formed.

A copper electroplating layer was formed on the copper seed layer by electroplating using a copper sulfate plating solution with a Cu ²⁺ concentration of about 20 g/L and a sulfuric acid concentration of about 200 ml/L. The copper electroplating layer was formed by applying a current at a plating speed of 2.3 m/min and a current density of 4.4 A/dm ² using 21 plating bath sections at a temperature of about 34° C., using no. 7~No. 21 In the plating tank section, No. 1~No. 6 The current density was increased by 2.5 times compared to the plating bath section to form a 2 ㎛ thick copper electroplating layer. Then, the protective film was reverse wound to produce a flexible copper foil laminated film with a total thickness of about 15 ㎛ with the protective film removed.

Example 2: Flexible copper foil laminated film

The copper electroplating layer was prepared in the same manner as in Example 1, except that current was applied at a plating speed of 2.4 m/min and a current density of 4.8 A/dm ² using 21 plating bath sections at a temperature of about 34°C. A flexible copper foil laminated film was produced.

Example 3: Flexible copper foil laminated film

The copper electroplating layer was prepared in the same manner as in Example 1, except that current was applied at a plating speed of 2.5 m/min and a current density of 5.2 A/dm ² using 21 plating bath sections at a temperature of about 34°C. A flexible copper foil laminated film was produced.

Comparative Example 1: Flexible copper foil laminated film

The copper electroplating layer was formed by applying a current at a plating speed of 1.5 m/min and a current density of 3.5 A/dm ² using 21 plating bath sections at a temperature of about 30° C., using no. 15~No. 21 In the plating tank section, No. 1~No. 14 Except that the current density was doubled compared to the plating bath section to form a 2 ㎛ thick copper electroplating layer, the same method as in Example 1 was performed to produce a flexible copper foil laminated film with a total thickness of about 2 ㎛.

Comparative Example 2: Flexible copper foil laminated film

The copper electroplating layer was prepared in the same manner as Comparative Example 1, except that current was applied at a plating speed of 1.6 m/min and a current density of 3.5 A/dm ² using 21 plating bath sections at a temperature of about 30°C. A flexible copper foil laminated film was produced.

Comparative Example 3: Flexible copper foil laminated film

The copper electroplating layer was prepared in the same manner as Comparative Example 1, except that current was applied at a plating speed of 1.7 m/min and a current density of 3.5 A/dm ² using 21 plating bath sections at a temperature of about 30°C. A flexible copper foil laminated film was produced.

Evaluation Example 1: Physical property evaluation

The physical properties of each flexible copper foil laminated film prepared in Examples 1 to 3 and Comparative Examples 1 to 3 were evaluated as follows. The results are shown in Table 1 below.

(1) Tensile strain (%)

Samples were prepared by cutting each flexible copper foil laminated film into 20 mm Water is continuously injected between the copper plating layer 4 and the polyimide film 1 (not shown in FIG. 2 due to the thin thickness of the tie layer 2 and the copper seed layer 3), but the copper plating layer is destroyed and the water When injecting to the point where it can no longer be injected, use Atotech's Ductensionmat equipment. The height (h) of the swollen copper plating layer as shown in Figure 2 was measured and the tensile strain calculated according to Equation 1 below was obtained. At this time, in order to measure the height (h) of the swollen copper plating layer, additional plating was performed on the surface of the copper plating layer (4) to maintain the thickness of the copper plating layer (4) at about 12 ㎛.

<Equation 1>

Tensile strain (%) = [Height of swollen copper plating layer (h)/Thickness of plating layer] x 100

(2) Tensile strength (MPa)

For each flexible copper foil laminated film, the same measurement method as the method for measuring tensile strain (1) above and using Atotech's Ductensionmat equipment was performed to determine the difference between the copper plating layer (4) and the polyimide film (1) as shown in Figure 2. In (not shown in FIG. 2 because the thickness of the tie layer 2 and the copper seed layer 3 is thin), the pressure of the injected water (P _max ), the height of the swollen copper plating layer (h), and the thickness of the copper plating layer (d) , and the radius (r) of the circle of the swollen copper plating layer was measured. From this, the tensile strength was calculated and obtained according to Equation 2 below. At this time, in order to measure the height (h) of the swollen copper plating layer, additional plating was performed on the surface of the copper plating layer (4) to maintain the thickness of the copper plating layer (4) at about 12 ㎛.

<Equation 2>

Tensile strength (MPa) = (hx P _max )/(2 xd) = {(r ² + h ² ) x P _max }/(4h xd)

(3) Flexing resistance - MIT

Each flexible copper foil laminated film was cut to a size of 80 mm Using MIT, the number of reciprocating foldings until the crack area became 6 mm ² or more was recorded. Among these, for Example 3, an optical microscope image when the number of reciprocating folds was 360 using MIT is shown in Figure 3. At this time, the area of the crack was calculated by measuring the width (width) and length (length) of the box portion, respectively, as shown in FIG. 3 using an optical microscope.

division Tensile strain (%) Tensile strength (MPa) Number of round trip folds (times) Example 1 14.1 28.7 135 Example 2 16.3 31.7 274 Example 3 20.4 32.4 360 Comparative Example 1 11 32.8 50 Comparative Example 2 11.3 35.2 50 Comparative Example 3 12.5 38.5 70

Referring to Table 1, the tensile strain of the flexible copper clad laminated film manufactured in Examples 1 to 3 was 14.1 % to 20.4 %, and was higher compared to the flexible copper clad laminated film manufactured in Comparative Examples 1 to 3. The tensile strength of the flexible copper clad laminated film manufactured in Examples 1 to 3 was 28.7 MPa to 32.4 MPa, and was lower than that of the flexible copper clad laminated film manufactured in Comparative Examples 1 to 3. The reciprocating folding number of the flexible copper clad laminated film manufactured in Examples 1 to 3 was significantly higher than the reciprocating folding number of the flexible copper clad laminated film manufactured in Comparative Examples 1 to 3, at more than 135 times. From this, it can be seen that the flexible copper foil laminated film manufactured in Examples 1 to 3 has significantly improved bending resistance compared to the flexible copper foil laminated film manufactured in Comparative Examples 1 to 3.

1: polyimide substrate (film), 2: tie layer, 3: copper seed layer,
4: Copper plating layer, 10: Flexible copper foil laminated film

Claims (11)

Polyimide with a thickness of 50 ㎛ or less write;
A tie layer located on at least one side of the polyimide substrate; and
It includes a copper layer located on the tie layer,
The copper layer includes a copper plating layer having a thickness of 1.0 ㎛ to 10.0 ㎛ on its surface,
The copper plating layer is an electroplating layer formed by applying a current at a rate of 2.2 m/min to 2.5 m/min,
The copper plating layer includes copper particles grown at a current density of 4.4 A/dm ² to 5.2 A/dm ² ,
The copper plating layer is electrolytically formed by using a plurality of plating baths and increasing the current density in the plating bath section after 1/3 of the plurality of total plating tank sections by 2 to 3 times compared to the plating tank section before 1/3. It is a plating layer,
A flexible copper foil laminated film having a tensile strain of 14% to 21%. delete delete According to paragraph 1,
A flexible copper foil laminated film having a tensile strength of 28 MPa to 32.5 MPa. According to paragraph 1,
A flexible copper foil laminated film with a number of reciprocating folds of more than 130 times until disconnection occurs when measured by MIT at an angle of 135° and a speed of 175 rpm. Polyimide with a thickness of 50 ㎛ or less Preparing a substrate;
Forming a tie layer on at least one side of the polyimide substrate;
forming a copper layer on the tie layer; and
The copper layer includes forming a copper electroplating layer on the surface of the copper layer to produce a flexible copper foil laminated film,
The copper electroplating layer is formed by applying a current at a speed of 2.2 m/min to 2.5 m/min and a current density of 4.4 A/dm ² to 5.2 A/dm ² ,
The copper electroplating layer is formed by using a plurality of plating baths and increasing the current density in the plating bath section after 1/3 of the plurality of total plating tank sections by 2 to 3 times compared to the plating tank section before 1/3. become,
A method of manufacturing a flexible copper foil laminated film having a tensile strain of 14% to 21%. delete According to clause 6,
A method of manufacturing a flexible copper foil laminated film, wherein the copper electroplating layer is formed by plating at a temperature of 30 ℃ to 34 ℃. According to clause 6,
A method of manufacturing a flexible copper foil laminated film having a tensile strength of 28 MPa to 32.5 MPa. According to clause 6,
A method of manufacturing a flexible copper foil laminated film in which the number of reciprocating folds until disconnection occurs when measured by MIT at an angle of 135° and a speed of 175 rpm is more than 130 times. An electrical device comprising the flexible copper foil laminated film according to any one of claims 1, 4, and 5.

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