Polyimide film for flexible metal clad laminate, and manufacturing method therefor

Abstract

The present invention relates to a polyimide film for a flexible metal clad laminate and a manufacturing method therefor and, more specifically, to a polyimide film comprising a polyimide layer and a diamine coating layer formed on one surface or both surfaces of the polyimide layer, and a manufacturing method therefor.

Description

Polyimide film for flexible metal-clad laminate and method for manufacturing the same

[0001] The present invention relates to a polyimide film for a flexible metal-clad laminate and a method for manufacturing the same, and more particularly, to a polyimide film including a polyimide layer and a diamine coating layer formed on one or both sides of the polyimide layer and a method for manufacturing the same.

[0002] Polyimide (PI) is a polymer material based on a rigid aromatic backbone and an imide ring with excellent chemical stability. It boasts exceptional heat resistance, chemical resistance, electrical insulation, chemical resistance, and weather resistance among organic materials. Therefore, polyimide is attracting attention as an insulating material for microelectronic components that require these properties.

[0003] Examples of microelectronic components include thin circuit boards with high circuit integration and flexibility to enable lightweight and miniaturized electronic products, and the polyimide is widely used as an insulating film for thin circuit boards.

[0004] The above thin circuit board generally has a structure in which a circuit including a metal foil is formed on an insulating film. Such a thin circuit board is referred to as a flexible metal foil clad laminate in a broad sense, and when a thin copper plate is used as the metal foil, it is also referred to as a flexible copper clad laminate (FCCL) in a narrower sense.

[0005] Examples of methods for manufacturing such flexible metal foil laminates include (i) a casting method in which polyamic acid, a precursor of polyimide, is cast or applied onto a metal foil and then imidized, (ii) a metallizing method in which a metal layer is directly installed on a polyimide film by sputtering, and (iii) a lamination method in which a polyimide film and a metal foil are bonded using heat and pressure through an adhesive film.

[0006] The double lamination method offers advantages over the casting method in that it can be applied to a wider range of metal foil thicknesses and has lower equipment costs than the metallizing method. Lamination equipment typically employed includes roll lamination equipment, which continuously laminates materials by feeding them in rolls, and double-belt press equipment. Among the above, the thermal roll lamination method utilizing a thermal roll lamination device is more preferable from a productivity standpoint.

[0007] Recently, the pitch between microcircuits and the respective line widths have been further reduced, which has led to a decrease in the bonding area between the polyimide film and the metal layer, and thus a stronger bonding force is required between the polyimide film and the metal layer.

[0008] Conventionally, the adhesion between a polyimide film and a metal plate has been improved by using a coupling agent capable of chemically and / or physically bonding the surface of the polyimide film and the surface of the metal layer. In this case, chemical bonding can generally mean an interaction in which a portion of the coupling agent hydrogen bonds with a portion of the polymer chain of the polyimide film, and another portion hydrogen bonds with oxygen, etc. present on the surface of the metal layer.

[0009] On the other hand, the adhesion was also improved by applying metal particles into the polyimide film to improve the surface energy of the metal layer deposited by sputtering, such as copper.

[0010] Meanwhile, a polyimide film can be manufactured from a polyamic acid solution, which is its precursor. Specifically, a polyimide film can be manufactured by applying a polyamic acid solution in the form of a thin film on a support, and then converting an amic acid group in the polyamic acid into an imide group through a ring closure and dehydration reaction using heat and / or a chemical catalyst through an 'imidization' process.

[0011] Here, the coupling agent and metal powder can be physically and / or chemically bound to a portion of the polyimide polymer chain during the imidization process. For this reason, the coupling agent and metal powder are used as a liquid mixed into a polyamic acid solution.

[0012] However, the coupling agent mixed into the polyamic acid solution as described above is dispersed throughout the solution, and thus can remain dispersed until the imidization of the polyamic acid solution is completed. Therefore, in the polyimide film manufactured, most of the coupling agent exists on the inner side of the film where it has difficulty interacting with the metal layer, and on the film surface or adjacent areas where it can interact with the metal layer, it exists in relatively small amounts or may not exist at all in some cases.

[0013] In addition, in the case of a conventional polyimide film including a coupling agent and metal powder, there is a problem that a significant portion of the coupling agent and / or metal powder capable of interacting with the surface of the metal layer may be lacking, and as a result, it is difficult to develop adhesive strength with the metal layer at a desired level.

[0014]

[0015] For this reason, there is a need for a polyimide film with improved adhesion by improving the interaction between the polyimide film and the surface of metal particles or metal layers.

[0016] The present invention is intended to solve the problems of the above-mentioned prior art, and a technical task is to provide a polyimide film including a polyimide layer and a diamine coating layer formed on one or both sides of the polyimide layer, and a method for manufacturing the same.

[0017] In order to achieve the above technical task, according to one aspect of the present invention, a polyimide film is provided, which comprises a polyimide layer derived from a polyamic acid solution; and a diamine coating layer formed on one or both sides of the polyimide layer, which includes a diamine compound, wherein the polyimide film has an adhesive strength with a bonding sheet of 1,400 gf / cm or more.

[0018] According to another aspect of the present invention, a method for producing a polyimide film is provided, comprising: a step of producing a polyimide layer by applying a polyamic acid solution on a substrate and heat-treating the same; and a step of forming a diamine coating layer by applying a diamine compound solution in which a diamine compound is dissolved in an organic solvent on one or both sides of the polyimide layer and heat-treating the same, wherein the diamine compound concentration of the diamine compound solution is 0.01 to 10 wt%.

[0019] According to another aspect of the present invention, an electronic component comprising the polyimide film of the present invention is provided.

[0020] The polyimide film according to the present invention comprises a polyimide layer and a diamine coating layer formed on one or both sides of the polyimide layer, thereby exhibiting higher room temperature and heat-resistant adhesive strength to a bonding sheet and a metal layer compared to conventional films.

[0021] Hereinafter, embodiments and examples of the present invention will be described in detail so that those skilled in the art can easily implement the invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments and examples described herein. Throughout this specification, when a part is said to "include" a certain component, unless specifically stated otherwise, this does not exclude other components, but rather means that other components may be included.

[0022] In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise.

[0023] When interpreting a component, it is interpreted as including the error range even if there is no separate explicit description.

[0024] In this specification, “a to b” indicating a numerical range is defined as ≥a and ≤b.

[0025] A polyimide film according to one aspect of the present invention comprises: a polyimide layer derived from a polyamic acid solution; and a diamine coating layer formed on one or both sides of the polyimide layer, the diamine coating layer including a diamine compound, wherein the polyimide film has an adhesive strength with a bonding sheet of 1,400 gf / cm or more.

[0026]

[0027] The polyimide layer included in the polyimide film of the present invention can be manufactured by imidizing a polyamic acid solution containing a polyamic acid formed by a reaction of a dianhydride monomer and a diamine monomer, and can include the dianhydride monomer and the diamine monomer as polymerization units. The polyamic acid can have a weight average molecular weight of 100,000 to 500,000. The weight average molecular weight of the polyamic acid can be, for example, 150,000 to 500,000, for another example, 100,000 to 400,000, for another example, 250,000 to 400,000, but is not limited thereto.

[0028] The polyamic acid solution used in the polyimide film of the present invention includes a polyamic acid formed by the reaction of a dianhydride monomer and a diamine monomer. As the dianhydride monomer and the diamine monomer, various monomers commonly used in the field of polyimide film production can be used. For example, the dianhydride monomer can be an aromatic dianhydride monomer, and the diamine monomer can be an aromatic diamine monomer. Examples of dianhydride monomers include pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, oxydiphthalic dianhydride, diphenylsulfone-3,4,3',4'-tetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)sulfide dianhydride, 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride, 2,3,3',4'-benzophenonetetracarboxylic dianhydride, 3,3',4,4'-benzophenonetetracarboxylic dianhydride, bis(3,4-dicarboxyphenyl)methane dianhydride, 2,2-bis(3,4-dicarboxyphenyl)propane dianhydride, p-phenylenebis(trimellitic acid monoester anhydride), p-biphenylenebis(trimellitic acid monoester anhydride), m-terphenyl-3,4,3',4'-tetracarboxylic acid dianhydride, p-terphenyl-3,4,3',4'-tetracarboxylic acid dianhydride, 1,3-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)benzene dianhydride, 1,4-bis(3,4-dicarboxyphenoxy)biphenyl dianhydride, 2,2-bis[(3,4-dicarboxy phenoxy)phenyl]propane dianhydride, 2,3,6,7-naphthalenetetracarboxylic acid dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 4,4'-(2,2-hexafluoroisopropylidene)diphthalic dianhydride, or a combination thereof may be used, but is not limited thereto. As the diamine monomer, a diamine monomer containing one benzene ring (e.g., 1,4-diaminobenzene, 1,3-diaminobenzene, 2,4-diaminotoluene, 2,6-diaminotoluene, 3,5-diaminobenzoic acid, etc.)Diamine monomers containing two benzene rings (e.g., diaminodiphenyl ethers such as 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminodiphenylmethane, 3,3'-dicarboxy-4,4'-diaminodiphenylmethane, 3,3',5,5'-tetramethyl-4,4'-diaminodiphenylmethane, bis(4-aminophenyl)sulfide, 4,4'-diaminobenzanilide, 3,3'-dimethylbenzidine, 2,2'-Dimethylbenzidine, 3,3'-Dimethoxybenzidine, 2,2'-Dimethoxybenzidine, 3,3'-Diaminodiphenyl ether, 3,4'-Diaminodiphenyl ether, 4,4'-Diaminodiphenyl ether, 3,3'-Diaminodiphenyl sulfide, 3,4'-Diaminodiphenyl sulfide, 4,4'-Diaminodiphenyl sulfide, 3,3'-Diaminodiphenyl sulfone, 3,4'-Diaminodiphenyl sulfone, 4,4'-Diaminodiphenyl sulfone, 3,3'-Diaminobenzophenone, 4,4'-Diaminobenzophenone, 3,3'-Diamino-4,4'-dichlorobenzophenone, 3,3'-Diamino-4,4'-dimethoxybenzophenone, 3,3'-Diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 2,2-bis(3-aminophenyl)propane, 2,2-bis(4-aminophenyl)propane, 2,2-bis(3-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane, 3,3'-diaminodiphenylsulfoxide, 3,4'-diaminodiphenylsulfoxide, 4,4'-diaminodiphenylsulfoxide, etc.), diamine monomers containing three benzene rings (e.g., 1,3-bis(3-aminophenyl)benzene, 1,3-bis(4-aminophenyl)benzene, 1,4-bis(3-aminophenyl)benzene, 1,4-bis(4-aminophenyl)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(3-aminophenoxy)benzene, 1,3-bis(3-aminophenoxy)-4-trifluoromethylbenzene, 3,3'-diamino-4-(4-phenyl)phenoxybenzophenone, 3,3'-diamino-4,4'-di(4-phenylphenoxy)benzophenone, 1,3-bis(3-aminophenylsulfide)benzene, 1,3-bis(4-aminophenylsulfide)benzene, 1,4-bis(4-aminophenylsulfide)benzene, 1,3-bis(3-aminophenylsulfone)benzene, 1,3-bis(4-aminophenylsulfone)benzene, 1,4-bis(4-aminophenylsulfone)benzene, 1,3-bis[2-(4-aminophenyl)isopropyl]benzene, 1,4-bis[2-(3-aminophenyl)isopropyl]benzene, 1,4-bis[2-(4-aminophenyl)isopropyl]benzene, etc.), diamine monomers containing four benzene rings (e.g., 3,3'-Bis(3-aminophenoxy)biphenyl, 3,3'-bis(4-aminophenoxy)biphenyl, 4,4'-bis(3-aminophenoxy)biphenyl, 4,4'-bis(4-aminophenoxy)biphenyl, bis[3-(3-aminophenoxy)phenyl]ether, bis[3-(4-aminophenoxy)phenyl]ether, bis[4-(3-aminophenoxy)phenyl]ether, bis[4-(4-aminophenoxy)phenyl]ether, bis[3-(3-aminophenoxy)phenyl]ketone, bis[3-(4-aminophenoxy)phenyl]ketone, bis[4-(3-aminophenoxy)phenyl]ketone, bis[4-(4-aminophenoxy)phenyl]ketone, bis[3-(3-aminophenoxy)phenyl]sulfide, Bis[3-(4-aminophenoxy)phenyl]sulfide, bis[4-(3-aminophenoxy)phenyl]sulfide, bis[4-(4-aminophenoxy)phenyl]sulfide, bis[3-(3-aminophenoxy)phenyl]sulfone, bis[3-(4-aminophenoxy)phenyl]sulfone, bis[4-(3-aminophenoxy)phenyl]sulfone, bis[3-(3-aminophenoxy)phenyl]methane, bis[3-(4-aminophenoxy)phenyl]methane, bis[4-(3-aminophenoxy)phenyl]methane, bis[4-(4-aminophenoxy)phenyl]methane, 2,2-bis[3-(3-aminophenoxy)phenyl]propane, 2,2-bis[3-(4-aminophenoxy)phenyl]propane, 2,2-bis[4-(3-aminophenoxy)phenyl]propane, 2,2-bis[4-(4-aminophenoxy)phenyl]propane, 2,2-bis[3-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane,2,2-bis[3-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(3-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, 2,2-bis[4-(4-aminophenoxy)phenyl]-1,1,1,3,3,3-hexafluoropropane, etc.), or a combination thereof, but is not limited thereto.

[0029] In particular, as the dianhydride monomer, at least one selected from the group consisting of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4-biphenyltetracarboxylic dianhydride, oxydiphthalic anhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride, and 3,3',4,4'-benzophenonetetracarboxylic dianhydride may be used, and as the diamine monomer, at least one selected from the group consisting of 4,4'-oxydianiline, 3,4'-oxydianiline, p-phenylenediamine, m-phenylenediamine, 4,4'-methylenedianiline, 3,3'-methylenedianiline, and 4,4'-diamino-2,2'-dimethylbiphenyl may be used.

[0030] The solvents included in the polyamic acid solution of the present invention may include, but are not limited to, sulfoxide-based solvents such as dimethyl sulfoxide and diethyl sulfoxide; formamide-based solvents such as N,N-dimethylformamide and N,N-diethylformamide; acetamide-based solvents such as N,N-dimethylacetamide and N,N-diethylacetamide; pyrrolidone-based solvents such as N-methyl-2-pyrrolidone and N-vinyl-2-pyrrolidone; phenol-based solvents such as phenol, o-, m-, or p-cresol, xylenol, halogenated phenols, and catechol; aprotic polar solvents such as hexamethylphosphoramide and γ-butyrolactone; and quinoline, which may be used alone or in combination of two or more.

[0031] The polyamic acid solution used in the production of the polyamide layer may contain an imidization catalyst, and may additionally contain, without particular limitation, other catalysts necessary for the production of the polyimide film, such as a dehydrating agent.

[0032] The above imidization catalyst promotes a ring closure reaction for polyamic acid, and examples of catalysts that can be used include aliphatic tertiary amines, aromatic tertiary amines, and heterocyclic tertiary amines. Among these, heterocyclic tertiary amines can be used from the viewpoint of reactivity as a catalyst.

[0033] Examples of heterocyclic tertiary amines include quinoline, isoquinoline, β-picoline, and pyridine, and these can be used alone or in combination of two or more.

[0034] Additionally, the polyimide layer of the present invention may be surface-modified on one or both sides by corona or plasma treatment. Such surface modification can activate the -OH groups within the surface of the polyimide layer, thereby increasing adhesive strength.

[0035] Corona treatment is 150 to 400 W / m 2 / can be performed under the conditions of , and a higher processing volume can be applied when the composition of the film does not have sufficient surface activity.

[0036]

[0037] The polyimide film of the present invention may include a diamine coating layer containing a diamine compound formed on one or both sides of the polyimide layer.

[0038] The diamine compound included in the above diamine coating layer may be at least one selected from the group consisting of 4,4'-oxydianiline (ODA), 3,4'-oxydianiline (ODA), p-phenylenediamine, m-phenylenediamine, 4,4'-methylenedianiline, 3,3'-methylenedianiline, and 4,4'-diamino-2,2'-dimethylbiphenyl.

[0039] The above polyimide film may have an adhesive strength with the bonding sheet of 1,400 gf / cm or more, 1,420 gf / cm or more, 1,450 gf / cm or more, 1,500 gf / cm or more, 1,550 gf / cm or more, or 1,590 gf / cm or more, 1,800 gf / cm or less, 1,750 gf / cm or less, 1,700 gf / cm or less, 1,650 gf / cm or less, or 1,600 gf / cm or less, for example, 1,400 to 1,800 gf / cm, 1,420 to 1,700 gf / cm or less, or 1,450 gf / cm to 1,600 gf / cm.

[0040] The above bonding sheet may include, but is not limited to, an epoxy-based or fluorine-based compound.

[0041] The contact angle of the above polyimide film may be 110° or less, 100° or less, 98° or less, 85° or less, or 75° or less due to the inclusion of a diamine coating layer, and may be 35° or more, 45° or more, 50° or more, 55° or more, or 60° or more, for example, 45° to 98°, or 50° to 75°.

[0042] In addition, the polyimide film of the present invention may have an improvement rate of heat-resistant plating adhesion of 10% or more, 15% or more, 25% or more, or 30% or more, and may have an improvement rate of 60% or less, 55% or less, or 50% or less, compared to a conventional polyimide film on which a diamine coating layer is not formed.

[0043]

[0044] According to another aspect of the present invention, a method for producing a polyimide film is provided, comprising: a step of producing a polyimide layer by applying a polyamic acid solution on a substrate and heat-treating the polyimide layer; and a step of forming a diamine coating layer by applying a diamine compound solution in which a diamine compound is dissolved in an organic solvent on one or both sides of the polyimide layer and heat-treating the diamine compound solution, wherein the diamine compound concentration of the diamine compound solution is 0.01 to 10 wt%.

[0045] In the above polyimide layer manufacturing step, a polyamic acid solution can be manufactured by polymerizing one or more dianhydride monomers and one or more diamine monomers in a solvent, and a dehydrating agent, an imidization catalyst, etc. can be mixed into the polyamic acid solution. The description of the components included in the polyamic acid solution is as described above.

[0046] The process of imidizing the above polyamic acid solution can be performed using a known imidization method, such as a thermal imidization method, a chemical imidization method, or a composite imidization method using a combination of the thermal imidization method and the chemical imidization method.

[0047] In the polyimide layer manufacturing step, the polyamic acid solution of the present invention is applied in a film shape on a substrate, and a gel film is manufactured by heating and drying at a temperature of 30 to 200°C for 15 seconds to 30 minutes, and then the gel film from which the substrate has been removed is heat-treated at a temperature of 250 to 600°C for 15 seconds to 30 minutes. However, the present invention is not limited thereto.

[0048]

[0049] The manufacturing method of the present invention may further include, after the polyimide layer manufacturing step, a surface modification step of treating one or both sides of the polyimide layer with corona or plasma. Through this surface modification, the -OH groups within the surface of the polyimide layer can be activated, thereby increasing adhesive strength.

[0050] Corona treatment is 150 to 400 W / m 2 / can be performed under the conditions of , and a higher processing volume can be applied when the composition of the film does not have sufficient surface activity.

[0051]

[0052] In the above diamine coating layer forming step, a diamine compound solution in which a diamine compound is dissolved in an organic solvent may be applied to one or both sides of the surface-modified polyimide layer and heat-treated.

[0053] The concentration of the diamine compound in the above diamine compound solution may be 0.01 wt% or more, 0.02 wt% or more, 0.03 wt% or more, 0.05 wt% or more, or 0.08 wt% or more, and may be 10 wt% or less, 8 wt% or less, 5 wt% or less, 3 wt% or less, 1 wt% or less, 0.8 wt% or less, 0.6 wt% or less, 0.5 wt% or less, 0.3 wt% or less, or 0.2 wt% or less, for example, 0.01 to 10 wt%, 0.02 to 5 wt%, 0.05 to 1 wt%, or 0.08 to 0.3 wt%. When the concentration of the diamine compound is lower than the above range, the adhesive strength with the bonding sheet may be reduced, and when the concentration of the diamine compound is higher than the above range, the coatability (visual appearance of the coating) may be poor.

[0054] The diamine compound is as described above, and the solvent of the diamine compound solution may be selected from acetone, dimethylformamide, or a mixture thereof.

[0055] The diamine coating layer forming step can be performed at a temperature of 150 to 300°C, for example, 160 to 290°C, 170 to 250°C, or 180 to 220°C, for 1 minute to 10 minutes, for example, 1 minute to 8 minutes, 1 minute to 5 minutes, or 1 minute to 3 minutes.

[0056] In one specific example, the step of forming a diamine coating layer may be performed by coating a diamine compound solution on the surface of the modified polyimide layer using a bar coater, but the coating method is not limited thereto.

[0057]

[0058] According to another aspect of the present invention, an electronic component is provided comprising the polyimide film of the present invention. In one specific embodiment, the polyimide film may be included as an insulating film.

[0059] The electronic component may be a semiconductor device or a flexible circuit board. In addition, the flexible circuit board may include a polyimide film and a layer formed on one or both sides of the polyimide film, including a bonding sheet; a metal layer; or a combination thereof.

[0060] The above bonding sheet may include, but is not limited to, an epoxy and / or a fluorine-based compound.

[0061] The above metal layer may be formed by depositing copper by sputtering, but is not limited thereto.

[0062]

[0063] Hereinafter, the present invention will be described in more detail with examples. However, these examples are presented as preferred examples of the present invention and should not be construed as limiting the present invention in any way.

[0064]

[0065] [Example]

[0066]

[0067] 1. Manufacturing Example 1 (Manufacturing of surface-modified polyimide layer)

[0068] 164.0 g of dimethylformamide and 41.0 g of quinoline were added as solvents to the reactor and the temperature was adjusted to 20°C. 21.5 g of 4,4'-oxydianiline (ODA) as a diamine monomer was added, followed by 23.4 g of pyromellitic dianhydride (PMDA) as a dianhydride monomer to prepare a polyamic acid solution.

[0069] In addition, a polyamic acid solution was prepared by adding 0.45 mol, 2.34 mol, and 2.83 mol of a catalyst component including β-picoline (BP) as an imidizing agent, acetic anhydride (AA) as a dehydrating agent, and dimethylformamide (DMF) as a catalyst solvent, respectively, to 1 mol of the amic acid group in the polyamic acid.

[0070] The prepared polyamic acid solution was cast into a 500 μm film on a SUS plate (100SA, Sandvik) using a doctor blade and dried at a temperature range of 100°C to 200°C to produce a self-supporting gel film.

[0071] Next, the gel film was peeled off from the SUS plate, fixed to a pin frame, and transferred to a high-temperature tenter. The film was heated from 200°C to 700°C in the high-temperature tenter, cooled to 25°C, and then separated from the pin frame to obtain a polyimide layer, and 250 W / m of heat was applied to one side of the polyimide layer. 2 The surface modification process was performed by activating the -OH group on the surface through corona (air plasma) treatment under the conditions of / min.

[0072]

[0073] 2. Manufacturing Example 2 (Formation of diamine coating layer)

[0074] As shown in Table 1 below, a diamine compound solution was prepared by dissolving oxydianiline (ODA) as a diamine compound in acetone and DMF, which are organic solvents, and then the diamine compound solution was applied to one side of the surface-modified polyimide layer formed in Manufacturing Example 1, and heat-treated at 200°C for 2 minutes in a hot air oven to form a diamine coating layer. The coatability (appearance) was evaluated and shown in Table 1.

[0075] [Table 1]

[0076]

[0077] As can be seen in Table 1 above, when ethanol was used as an organic solvent, ODA was not dissolved, and when acetone and DMF were used as organic solvents, the coating properties were good when the ODA concentration was 0.1 wt%, but when the ODA concentration was 1 wt%, the appearance was poor.

[0078]

[0079] 3. Example 1 (Comparison of adhesive strength of polyimide films)

[0080] Surface-modified polyimide layer of Manufacturing Example 1 (Comparative Example 1-1),

[0081] A polyimide film (Comparative Example 1-2) in which a diamine coating layer was formed on a polyimide layer manufactured in the same manner as in Manufacturing Example 1 except for surface modification, using a 0.1 wt% diamine compound solution of acetone-ODA.

[0082] A polyimide film (Example 1) in which a diamine coating layer is formed on the surface-modified polyimide layer of Manufacturing Example 1 using a 0.1 wt% diamine compound solution of acetone-ODA.

[0083] A polyimide film (Example 2) in which a diamine coating layer was formed on a polyimide layer manufactured in the same manner as in Manufacturing Example 1 except for surface modification, using a 1 wt% diamine compound solution of acetone-ODA, and

[0084] The contact angle, adhesion to the bonding sheet (BS), and peeling surface of a polyimide film (Example 3) in which a diamine coating layer was formed on the surface-modified polyimide layer of Manufacturing Example 1 using a 1 wt% diamine compound solution of acetone-ODA were checked, and the results are shown in Table 2.

[0085]

[0086] For BS adhesion measurements, copper-bonding sheet (BS)-polyimide samples were stacked on both sides of the polyimide layer with or without surface modification, and then subjected to high-pressure compression at 150°C, followed by cutting into 1.5 cm wide samples. Adhesion was analyzed using a UTM device. Analysis was performed over a 50 mm section at a speed of 20 mm / min under 90° peeling conditions.

[0087]

[0088] - Bonding sheet (BS): An adhesive sheet made of epoxy material was used.

[0089] - Contact angle: Measures the contact angle between water and the film surface.

[0090] - Coating: Visually inspect to see if the coating is evenly applied.

[0091] - Peeling surface: The peeling surface of the sample for which the adhesive strength measurement was completed was subjected to EDS analysis in the SEM equipment, and the components of the peeling surface were identified through EDS analysis to identify the peeled layer.

[0092] [Table 2]

[0093]

[0094] It was confirmed that Comparative Example 1-1, which does not include a diamine coating layer, has very low BS adhesion and a very small contact angle compared to Comparative Example 1-2 and Examples 1 to 3, which include a diamine coating layer.

[0095] In Comparative Examples 1-2 and Example 1, where the concentration of ODA was 0.1 wt%, both showed good coating properties and easy adhesion of BS. However, in Example 1, where surface modification of the polyimide layer was performed, a low contact angle and high BS adhesion were observed, and accordingly, the peeled surface appeared as BS-copper foil, indicating that the adhesion between the polyimide layer and BS was high.

[0096] On the other hand, in Comparative Examples 1-2, where surface modification of the polyimide layer was not performed, a large contact angle and low BS adhesion were observed compared to Example 1, and the peeling surface also appeared as film-BS, indicating that the adhesion between the polyimide layer and BS was relatively low.

[0097] In Example 2, where the ODA concentration was 1 wt%, high BS adhesion was observed, but it was confirmed that the coating properties were somewhat poorer than in Example 1.

[0098] In Example 3, where the ODA concentration was 1 wt% and surface modification was performed, high BS adhesion was observed, but it was confirmed that the coating properties were somewhat poorer than in Example 1.

[0099]

[0100] 4. Example 2 (Evaluation of heat-resistant plating adhesion)

[0101] The polyimide films that were surface-modified and not diamine-coated in Comparative Example 1-1 were used as Comparative Examples 2-1 to 2-4, and the polyimide films that were surface-modified and diamine-coated in Example 1 were used as Examples 2-1 to 2-4, to evaluate the heat-resistant plating adhesion. The polyimide films of each Comparative Example and Example were manufactured in the same manner as Manufacturing Example 1, except that the diamine monomer and dianhydride monomer described in Table 3 below were used (surface modification and diamine coating were not performed in the Comparative Example).

[0102]

[0103] To prepare samples for evaluating heat-resistant plating adhesion, a sputtering device was used to sputter the surface of a polyimide film through nickel and copper electrodes. Copper plating to a thickness of 8 μm was performed on the sputtered sample using an electroplating method using a copper plating solution. After attaching the DFR film to the polyimide, a 2 mm wide exposed DFR film pattern was formed through exposure. The DFR film and copper layer in the unexposed area were removed through etching / development. The exposed DRF film was dissolved in an alkaline solution and then washed with water to prepare samples for evaluating the plating adhesion. The heat-resistant plating adhesion was measured according to the following method and is shown in Table 4.

[0104]

[0105] - Heat-Resistant Plating Adhesion: After heating in a hot-air oven at a high temperature (150°C) for 7 days, the adhesion between the copper layer of the plating sample and the polyimide was measured. Adhesion was analyzed using a UTM device. Analysis was performed over a 50 mm section at a speed of 20 mm / min under 90°C peel conditions.

[0106] The heat-resistant plating adhesion enhancement ratio was calculated as (Example PI - Comparative Example PI) / Comparative Example PI × 100.

[0107] [Table 3]

[0108]

[0109] PPD: p-Phenylenediamine

[0110] ODA: 4,4′-Oxydianiline

[0111] BPDA: 4,4'-Biphthalic dianhydride

[0112] PMDA: Pyromellitic dianhydride

[0113] m-TD: 4,4'-Diamino-2,2'-dimethylbiphenyl

[0114] [Table 4]

[0115]

[0116] In the case of the polyimide films of Examples 2-1 to 2-4 having surface modification and a diamine coating layer, it was confirmed that the heat-resistant plating adhesion was significantly superior to that of the comparative examples.

[0117]

[0118] As can be seen from the above, it was confirmed that the polyimide film according to the present invention can exhibit higher room temperature and heat-resistant adhesive strength to a bonding sheet and a metal layer than before, by including a polyimide layer whose surface is modified by corona or plasma treatment and a diamine coating layer formed on one or both sides of the polyimide layer.

[0119]

[0120] From the above description, those skilled in the art will understand that the present invention can be implemented in other specific forms without altering its technical spirit or essential characteristics. In this regard, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of the present invention should be interpreted as encompassing all changes or modifications derived from the meaning and scope of the following claims and their equivalent concepts, rather than the detailed description above.

Claims

1. A polyimide layer derived from a polyamic acid solution; and A polyimide film comprising a diamine coating layer containing a diamine compound formed on one or both sides of the polyimide layer, The above polyimide film has an adhesive strength with the bonding sheet of 1,400 gf / cm or more. Polyimide film.

2. In paragraph 1, The diamine compound included in the above diamine coating layer is at least one selected from the group consisting of 4,4'-oxydianiline, 3,4'-oxydianiline, p-phenylenediamine, m-phenylenediamine, 4,4'-methylenedianiline, 3,3'-methylenedianiline and 4,4'-diamino-2,2'-dimethylbiphenyl. Polyimide film.

3. In paragraph 1, The above polyimide layer is, A dianhydride monomer, at least one selected from the group consisting of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4-biphenyltetracarboxylic dianhydride, oxydiphthalic anhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride and 3,3',4,4'-benzophenonetetracarboxylic dianhydride; and A diamine monomer comprising at least one selected from the group consisting of 4,4'-oxydianiline, 3,4'-oxydianiline, p-phenylenediamine, m-phenylenediamine, 4,4'-methylenedianiline, 3,3'-methylenedianiline and 4,4'-diamino-2,2'-dimethylbiphenyl as a polymerization unit. Polyimide film.

4. In paragraph 1, The above polyimide layer is surface-modified on one or both sides by corona or plasma treatment. Polyimide film.

5. In paragraph 1, The above polyimide film has a heat-resistant plating adhesion enhancement ratio of 10% to 60%. Polyimide film.

6. In paragraph 1, A polyimide film having a contact angle of 35° or more.

7. A polyimide layer manufacturing step of applying a polyamic acid solution on a substrate and performing heat treatment; and It includes a step of forming a diamine coating layer by applying a diamine compound solution in which a diamine compound is dissolved in an organic solvent to one or both sides of a polyimide layer and performing heat treatment. The diamine compound concentration of the above diamine compound solution is 0.01 to 10 wt%. Method for manufacturing polyimide film.

8. In paragraph 7, The above polyamic acid solution, A dianhydride monomer, at least one selected from the group consisting of pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylic dianhydride, 2,3,3',4-biphenyltetracarboxylic dianhydride, oxydiphthalic anhydride, bis(3,4-dicarboxyphenyl)sulfone dianhydride and 3,3',4,4'-benzophenonetetracarboxylic dianhydride; and A diamine monomer comprising at least one selected from the group consisting of 4,4'-oxydianiline, 3,4'-oxydianiline, p-phenylenediamine, m-phenylenediamine, 4,4'-methylenedianiline, 3,3'-methylenedianiline and 4,4'-diamino-2,2'-dimethylbiphenyl; Method for manufacturing polyimide film.

9. In paragraph 7, After the polyimide layer manufacturing step, a surface modification step of treating one or both sides of the polyimide layer with corona or plasma is additionally included. Method for manufacturing polyimide film.

10. In paragraph 9, The above surface modification step is performed at 150 to 400 W / m 2 / performed under the conditions of Method for manufacturing polyimide film.

11. In paragraph 7, The solvent of the above diamine compound solution is selected from acetone, dimethylformamide or a mixture thereof. Method for manufacturing polyimide film.

12. In paragraph 7, The above diamine coating layer forming step is performed at a temperature of 150 to 300°C for 1 to 10 minutes. Method for manufacturing polyimide film.

13. An electronic component comprising a polyimide film according to any one of claims 1 to 6.

14. In paragraph 13, An electronic component, wherein the electronic component is a semiconductor device or a flexible circuit board.

15. In paragraph 14, The above flexible circuit board is, Polyimide film and A layer formed on one or both sides of the polyimide film, comprising a bonding sheet; a metal layer; or a combination thereof. Electronic components.

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