JP7189284B2 - FLEXIBLE COPPER FILM LAMINATED FILM AND ELECTRICAL DEVICE CONTAINING THE SAME - Google Patents

Description

TECHNICAL FIELD The present invention relates to a flexible copper clad laminate film and an electric device including the same.

Recently, due to the accelerated growth of the mobile market and the increased demand for LCD (liquid crystal display) TV (television) monitors, thin film, miniaturization, weight reduction, durability and high performance are being pursued in fields such as electronic products and semiconductor integrated circuits. The development of materials with image quality characteristics is encouraged. In the field of flexible copper clad laminate (FCCL) used in driver integrated circuits (ICs) for LCDs, there is also an increasing demand for fine patterning, thinning and durability.

In line with such trends, chip-on-film (COF) technology, for example, is being used. The chip-on-film (COF) technology uses a thin film with a very fine pitch. It is also used for increasing pixels in display devices. Also, such chip-on-film (COF) technology enables miniaturization of the chip module, and the material is flexible, bendable and rollable, but in order to increase such refraction resistance, , the film is subjected to a high-temperature heat treatment process. However, through such a process, the flexible copper clad laminate film suffers processing problems such as thermal shock, film folding, curling or wrinkling.

Therefore, there is still a need for a flexible copper clad laminate film and electrical devices containing the same for improving the refractive resistance without causing such processing problems.

The problem to be solved by the present invention is to provide a flexible copper clad laminate film with improved refraction resistance.

The problem to be solved by the present invention is to provide an electric element including the flexible copper clad laminate film.

According to one aspect,
a polyimide base material having a thickness of 20 μm or less;
a tie layer disposed on at least one side of the polyimide substrate;
a copper layer having a thickness of 2.0 μm to 8.7 μm disposed on at least one side of the tie layer;
the copper particles included in the copper layer have a grain size of 1.6 μm to 2.5 μm;
Provided is a flexible copper clad laminate film having a reciprocating folding number of 40 or more until a crack having an area of 4.5 mm ² or more is generated as measured by MIT.

The copper layer is also an electrolytic plating layer.
The copper layer is also an electrolytic plating layer formed by applying current at a plating speed of 1.5 m/min to 2.5 m/min.
The copper particles of the copper layer are also particles grown at a current density of 1.0 A/dm ² to 4.0 A/dm ² .
The copper layer is formed by using a plurality of plating baths, and in the plurality of entire plating bath sections, the current density in the plating bath section after 2/3 is 1.5 compared with the plating bath section before 2/3. It is also an electrolytic plated layer formed by increasing the thickness more than twice.

A copper seed layer may further be included between the tie layer and the copper layer.
Said film does not contain an adhesive layer.
The tie layer is also a deposited layer containing an alloy containing Ni and Cr.
Other aspects
An electrical device is provided that includes the flexible copper foil laminate film described above.

The flexible copper clad laminate film according to the present invention may have improved refraction resistance.

1 is a schematic cross-sectional view of a flexible copper clad laminate film according to an embodiment; FIG. (a) to (c) are focused ion beam (FIB) images obtained by cutting the flexible copper foil laminate films of Examples 1 to 3 into 10 mm×10 mm sizes and observing the surfaces at 15K magnification. 1 is a connected ion beam (FIB) image obtained by cutting the flexible copper foil laminate film according to Comparative Example 1 into a size of 10 mm×10 mm and observing the surface thereof at a magnification of 15K. (a) to (c) are the flexible copper foil laminate films according to Example 2, respectively, cut into 80 mm x 200 mm sizes, forming patterns of 15 mm width x 150 mm length, and then measured by MIT at an angle of 135 ± 5° and a speed of 175 ± 10 cpm. 4 is a view showing optical microscope images when the number of times of reciprocating folding is 30 times, 50 times, and 70 times when performing . (a) to (c) are each cut from the flexible copper foil laminate film according to Comparative Example 1 to a size of 80 mm x 200 mm, form a pattern of 15 mm width x 150 mm length, and then perform MIT measurement at an angle of 135 ± 5° and a speed of 175 ± 10 cpm. 4 is a view showing optical microscope images when the number of times of reciprocating folding is 30 times, 50 times, and 70 times when performing . (a) to (c) are each cut from the flexible copper foil laminate film according to Comparative Example 2 to a size of 80 mm x 200 mm, form a pattern of 15 mm width x 150 mm length, and then perform MIT measurement at an angle of 135 ± 5° and a speed of 175 ± 10 cpm. 4 is a view showing optical microscope images when the number of times of reciprocating folding is 20 times, 50 times, and 70 times when performing .

Hereinafter, a flexible copper clad laminate film and an electric device including the same will be described in detail with reference to embodiments and drawings of the present invention. It should be noted that the examples are merely presented by way of example to further illustrate the invention, and that the scope of the invention is not limited by the examples. It will be obvious to those skilled in the art.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. 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.

As used herein, the term "comprising" does not exclude other components, and means that other components may be included, 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 of the associated listed items. As used herein, the term "or" means "and/or." As used herein, the expression "at least one" or "one or more" before a component can complement a list of the entire component and can complement individual components of the description. does not mean that

As used herein, when a component is referred to as being placed "on" another component, the component is either placed directly on the other component, or the component is placed on top of the other component. There may be elements interposed between. On the other hand, when a component is referred to as being "directly on" another component, there are no intervening components present.

FIG. 1 is a schematic cross-sectional view of a flexible copper clad laminate film 10 according to one embodiment.
Referring to FIG. 1, a flexible copper clad laminate 10 according to an embodiment includes a polyimide substrate 1, a tie layer 2 disposed on at least one surface of the polyimide substrate 1, and a tie layer 2 on at least one surface of the tie layer 2. It is also a structure in which a copper layer 4 of .

The thickness of the polyimide base material 1 is also 20 μm or less. The flexible copper clad laminate film 10 according to one embodiment may include an ultralight and thin polyimide film in which the polyimide substrate 1 has a thickness of 12.5 μm or less. A flexible copper clad laminate film containing such a thin polyimide film can also have improved refraction resistance.

The tie layer 2 is also a deposited layer containing an alloy containing Ni and Cr. In the tie layer 2, the weight ratio of Ni to Cr may be, for example, 70:30, 75:25, 80:20, 85:15, or 90:10. , 95 to 5, or 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 deposited layer may also be formed from a copper seed layer having a thickness of, for example, approximately 200 Å to 2,000 Å.

The thickness of said copper layer 4 is also between 2.0 μm and 8.7 μm. For example, the thickness of the copper layer 4 may be 2.0 to 8.0 μm, 2.0 to 7.0 μm, 2.0 to 6.0 μm, or 2.0 to 5.0 μm. or even 2.0 to 4.0 μm.

The flexible copper clad laminate film 10 according to one embodiment can ensure improved refraction resistance even when the copper layer 4 has a thickness within the above range.

The copper layer 4 may include copper particles having a grain size of 1.6 μm to 2.5 μm. The copper layer 4 has, for example, a grain size of 1.7 μm to 2.5 μm, a grain size of 1.8 μm to 2.5 μm, a grain size of 1.8 μm to 2.4 μm, having a grain size of 1.8 μm to 2.3 μm, having a grain size of 1.8 μm to 2.2 μm, having a grain size of 1.8 μm to 2.1 μm, or having a grain size of 1.8 μm to 2.1 μm can have a grain size of The copper layer 4 contains copper particles having a crystal grain size within the range, so that a chip-on-film (COF) is formed on the copper layer for thinning and fine patterning. Improved refraction resistance required for technology can be ensured.

The copper layer 4 according to one embodiment has a reciprocating folding number of 40 times or more before a crack having an area of 4.5 mm ² or more occurs, as measured by MIT. The number of times of reciprocating folding is, for example, 45 times or more, 50 times or more, 55 times or more, 60 times or more, 65 times or more, or 70 times or more, 75 times or more, or even 80 times or more. The flexible copper clad laminate film 10 according to one embodiment does not require an additional process such as a heat treatment process, and may have improved refraction resistance.

The copper layer 4 is also an electrolytic plating layer. The electroplating layer can be formed by electroplating with an electroplating solution containing copper sulfate and sulfuric acid as basic substances to form a copper electroplating layer on at least one surface of the tie layer 2 . Furthermore, additives such as brighteners, levelers, correctors or moderators may be added to the electroplating solution for productivity and surface uniformity.

The copper layer is also an electrolytic plating layer formed by applying current at a plating speed of 1.5 m/min to 2.5 m/min.

The copper particles of the copper layer 4 are also particles grown at a current density of 1.0 A/dm ² to 4.0 A/dm ² . The copper particles of the copper layer 4 are also particles grown by applying two or more current densities within the current density range.

The copper layer is formed by using a plurality of plating baths, and in the plurality of entire plating bath sections, the current density in the plating bath section after 2/3 is 1.5 compared with the plating bath section before 2/3. It is also an electrolytic plated layer formed by increasing the thickness more than twice. The electroplating layer has fine copper particles and a uniform thickness by lowering the resistance and increasing the current density, thereby not only forming the copper layer 4 but also improving the resistance to refraction.

A copper seed layer 3 may further be included between the tie layer 2 and the copper layer 4 .
The thickness of the copper seed layer 3 is, for example, 0.1 μm to 3.0 μm, 0.1 μm to 2.6 μm, 0.1 μm to 2.4 μm, or 0.1 μm to 2.0 μm. 2 μm, or even 0.1 μm to 2.0 μm.

The flexible copper clad laminate film 10 does not contain an adhesive layer. The flexible copper clad laminate film 10 does not include an adhesive layer, but does not cause processing problems such as folding, curling or wrinkling of the film, and ensures a film with improved refraction resistance. can.

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

The acrylic adhesive layer is also a resin layer obtained by copolymerizing acrylic monomers. Examples of acrylic monomers include acrylic acid alkyl ester monomers such as ethyl acrylate, butyl acrylate, amyl acrylate, 2-ethylhexyl acrylate, octyl acrylate, cyclohexyl acrylate, and benzyl acrylate; butyl methacrylate, 2-ethylhexyl methacrylate, methacrylic acid alkyl ester monomers such as cyclohexyl methacrylate, benzylhexyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate; methyl acrylate, methyl methacrylate, vinyl acetate, styrene, acrylonitrile, acrylic acid, methacrylic acid, maleic anhydride, itaconic acid; monomers containing a carboxylic acid group; monomers containing a hydroxy group such as 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl acrylate, and 2-hydroxypropyl (meth)acrylate; N-methylolacrylamide , amide monomers such as acrylamide, methacrylamide, glycidylamide; For the acrylic resin, the monomers may be used singly or in combination.

Examples of still further acrylic monomers include lauryl acrylate, ethoxydiethylene glycol acrylate, methoxytriethylene glycol acrylate, phenoxyethyl acrylate, tetrahydrofurfuryl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, Single functional group acrylate monomers such as 2-hydroxy-3-phenoxyacrylate; neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate , dipentaerythritol hexaacrylate, multifunctional acrylates such as trimethylolpropane benzoate acrylic acid derivative monomers; 2-ethylhexyl methacrylate, n-stearyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate; single functional group methacrylate monomers such as acrylates, 2-hydroxyethyl methacrylate, 2-hydroxybutyl methacrylate; and monomers such as urethane acrylates such as glycerin dimethacrylate hexamethylene diisocyanate and pentaerythritol triacrylate hexamethylene diisocyanate. For the acrylic resin, the monomers or oligomers may be used singly or in combination.

The polymerization initiator used together with the acrylic resin may have an azo polymerization initiator. The azo polymerization initiator can be used without limitation as long as it is an azo polymerization initiator used in normal radical polymerization.

Examples of the azo polymerization initiator include 2,2′-azobis(isobutyronitrile) (AIBN), 2,2′-azobis(2-methylbutyronitrile) (AMBN), 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-methylbutyramide), 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-cyclohexyl-2-methylpropionamide) and the like. The azo polymerization initiator can be appropriately selected depending on the reaction conditions.

The acrylic adhesive layer may further contain 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. .

The total thickness of the flexible copper clad laminate film 10 is also 50 μm or less. The total thickness of the flexible copper clad laminate film 10 is, for example, 0.1 μm to 50 μm.
An electrical device according to another embodiment may include a flexible copper clad laminate film.

The electrical devices are also used in flexible printed circuit boards (FPCBs) and camera coils.

Hereinafter, the configuration of the present invention and the effects thereof will be described in detail through examples and comparative examples. However, it is a self-evident fact that the present examples are intended to explain the present invention more specifically, and that the scope of the present invention is not limited to those examples.

Example 1: Flexible copper foil laminate film A 12.5 μm thick polyimide film (Kapton 50ENC, manufactured by TDC) was prepared. On one surface of the polyimide film, an acrylic adhesive layer and a protective film (LE951, manufactured by Toyo Co., Ltd.) having a thickness of about 50 μm composed of a polyethylene terephthalate (PET) film were interleaved. A Ni/Cr alloy tie layer and a Cu seed layer are deposited on the opposite side of the polyimide substrate with the protective film by physical vapor deposition (PVD) using a roll-to-roll type sputtering device. formed sequentially. At this time, the tie layer has a weight ratio of Ni and Cr of 80:20 (purity: 99.9% or more) and is formed to a thickness of about 250 Å, and the Cu seed layer uses copper with a purity of 99.995%. and formed to a thickness of about 0.8 μm.

A copper electroplating layer was formed on the copper seed layer by electroplating using a copper sulfate plating solution having a Cu ²⁺ concentration of about 20 g/L and a sulfuric acid of about 200 ml/L. The copper electroplating layer is formed at a temperature of about 30° C., using 21 plating bath sections, a plating speed of 1.5 m/min to 2.5 m/min, and a plating rate of 1.0 A/dm ² to 4.0 A. /dm ² , but no. 15 to No. In the No. 21 plating tank section, the No. 1 to No. Compared with 14 plating bath sections, the current density was doubled to form a copper electrolytic plating layer with a thickness of 2 μm.

After that, the protective film was reversely wound to produce a flexible copper clad laminate film with a total thickness of about 2 μm from which the protective film was removed.

Example 2: Flexible copper foil laminate film The copper electroplating layer was formed at a temperature of about 30°C, using 21 plating bath sections, a plating speed of 1.5 m/min to 2.5 m/min, and 1 Current is applied at current densities between 0.0 A/dm ² and 4.0 A/dm ² , but no. 15 to No. In the No. 21 plating tank section, the No. 1 to No. The same method as in Example 1 was performed except that the current density was increased by 1.5 times compared to the 14 plating bath sections to form a copper electroplating layer with a thickness of 2 μm. A copper foil laminated film was produced.

Example 3: Flexible copper foil laminate film The copper electroplating layer was formed at a temperature of about 30°C, using 21 plating bath sections, a plating speed of 1.5 m/min to 2.5 m/min, and 1 Current is applied at current densities between 0.0 A/dm ² and 4.0 A/dm ² , but no. 15 to No. In the No. 21 plating tank section, the No. 1 to No. The same method as in Example 1 was performed except that the current density was increased by 2.5 times compared to the 14 plating bath sections to form a copper electroplating layer with a thickness of 2 μm. A copper foil laminated film was produced.

Comparative Example 1: Flexible copper foil laminate film A current was applied at a plating speed of min to 2.5 m/min and a current density of 1.0 A/dm ² to 4.0 A/dm ² to form a copper electroplated layer of 2 μm thickness. By performing the same method as in Example 1, a flexible copper foil laminate film having a total thickness of about 2 μm was produced.

Comparative Example 2: Flexible copper foil laminate film Example 1, except that a 25 μm thick polyimide film (model, TDC) was used instead of a 12.5 μm thick polyimide film (Kapton 50ENC, manufactured by TDC). A flexible copper foil laminate film having a total thickness of about 2 μm was produced by performing the same method as above.

Analysis Example 1: Focused Ion Beam (FIG) Analysis The flexible copper foil laminate films according to Examples 1 to 3 and Comparative Example 1 were cut into 10 mm x 10 mm size, and the surface was subjected to a connected ion beam (FIB) at a magnification of 15K. observed using the The results are shown in FIGS. 2(a), (b), (c) and FIG. At this time, in FIGS. 3(a), (b), and (c), the green lines are reference lines for measuring the grain size.

Referring to FIGS. 2(a) to (c), the flexible copper foil laminate films according to Examples 1 to 3 all have grown copper particles having a grain size of about 1.8 μm to 2.0 μm in the copper layer. can be observed.

Referring to FIG. 3, the flexible copper clad laminate film according to Comparative Example 1 is a copper layer, and grown copper particles having a grain size of about 0.2 μm to 0.25 μm can be observed.

Evaluation Example 1: Evaluation of Refraction Resistance The flexible copper foil laminate films of Examples 1 to 3 and Comparative Examples 1 and 2 were evaluated for refraction resistance. For the evaluation of refraction resistance, the flexible copper clad laminate film is cut into a size of 80 mm x 200 mm to form a pattern of 15 mm width x 150 mm length, and then measured by MIT at an angle of 135 ± 5 ° and a speed of 175 ± 10 cpm. , and evaluated by recording the number of reciprocating folds until the crack area reached 4.5 mm ² or more. At this time, the area of the crack was measured using an optical microscope, and as can be seen from FIGS. The horizontal (width) and the vertical (length) were measured and calculated in the box portion within the line representation. The results are shown in FIGS. 4(a) to (c), FIGS. 5(a) to (c), FIGS. 6(a) to (c) and Table 1, respectively. FIGS. 4(a) to 4(c) show optical microscope images when the number of reciprocal foldings of the flexible copper foil laminate film according to Example 2 is 30, 50, and 70 times. 5(a) to 5(c) are optical microscope images of the soft copper foil laminated film according to Comparative Example 1 when the number of reciprocal foldings is 30, 50, and 70. 6(a) to (c) show optical microscope images when the number of reciprocating foldings of the flexible copper foil laminate film according to Comparative Example 2 is 20, 50, and 70 times. be.

Referring to Table 1 and FIGS. 4(a) to (c), FIGS. 5(a) to (c) and FIGS. 6(a) to (c), the flexible copper foil laminate films according to Examples 1 to 3 are: In both cases, the number of times of reciprocating folding was 50 times or more until the crack area was 4.5 mm ² or more. In contrast, the flexible copper foil laminate films of Comparative Examples 1 and 2 had less than 40 reciprocating folds until the crack area reached 4.5 mm ² or more. Accordingly, it can be confirmed that the flexible copper clad laminate films according to Examples 1 to 3 have improved resistance to refraction compared to the flexible copper clad laminate films according to Comparative Examples 1 and 2.

REFERENCE SIGNS LIST 1 polyimide substrate 2 tie layer 3 copper seed layer 4 copper layer 10 flexible copper foil laminate film

Claims (8)

a polyimide base material having a thickness of 20 μm or less;
a tie layer disposed on at least one side of the polyimide substrate;
a copper layer having a thickness of 2.0 μm to 8.7 μm disposed on at least one side of the tie layer;
The copper particles contained in the copper layer have a crystal grain size of 1.6 μm to 2.5 μm,
A method for producing a flexible copper foil laminate film, wherein the number of reciprocal foldings until a crack having an area of 4.5 mm ² or more occurs is 40 or more when measured by MIT,
The copper layer is formed by using a plurality of plating baths, and in the plurality of entire plating bath sections, the current density in the plating bath section after 2/3 is 1.5 compared with the plating bath section before 2/3. A method for producing a flexible copper foil laminate film, which is formed as an electrolytic plated layer by raising the temperature more than twice . 2. The method for producing a flexible copper foil laminate film according to claim 1, wherein said copper layer is an electrolytic plated layer. The method of claim 1, wherein the copper layer is formed as an electrolytic plating layer by applying current at a line speed of 1.5 m/min to 2.5 m/min. The method of claim 1, wherein the copper particles of the copper layer are grown at a current density of 1.0 A/ ^dm2 to 4.0 A/ ^dm2 . 2. The method for producing a flexible copper clad laminate film as set forth in claim 1, further comprising a copper seed layer between said tie layer and said copper layer. 2. The method for producing a flexible copper clad laminate film according to claim 1, wherein said film does not contain an adhesive layer. 2. The method for producing a flexible copper clad laminate film according to claim 1, wherein the tie layer is a deposited layer containing an alloy containing Ni and Cr. a polyimide base material having a thickness of 20 μm or less;
a tie layer disposed on at least one side of the polyimide substrate;
a copper layer having a thickness of 2.0 μm to 8.7 μm disposed on at least one side of the tie layer;
The copper particles contained in the copper layer have a crystal grain size of 1.6 μm to 2.5 μm,
A method for producing a flexible copper foil laminate film for electric elements, wherein the number of times of reciprocating folding until a crack having an area of 4.5 mm ² or more occurs is 40 or more when measured by MIT ,
The copper layer is formed by using a plurality of plating baths, and in the plurality of entire plating bath sections, the current density in the plating bath section after 2/3 is 1.5 compared with the plating bath section before 2/3. A method for producing a flexible copper foil laminate film for electric elements , which is formed as an electrolytic plated layer by raising the temperature more than twice .

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