KR102272716B1 - Multilayer polyimide film having improved dimensional stability and adhesion, method for preparing the same - Google Patents

Abstract

The present invention comprises a core part comprising a structure derived from at least 4,4'-diamino-2,2'-dimethylbiphenyl compound, and a skin part comprising a structure derived from at least 3,5-diaminobenzoic acid compound, wherein the core part Provided are a multilayer polyimide film having a glass transition temperature (T _g ) of 360° C. or more, a skin portion having a glass transition temperature of 300° C. or more, and an adhesive strength of 1,000 gf/cm or more, and a method for manufacturing the same.

Description

Multilayer polyimide film with excellent dimensional stability and adhesion, and manufacturing method thereof {MULTILAYER POLYIMIDE FILM HAVING IMPROVED DIMENSIONAL STABILITY AND ADHESION, METHOD FOR PREPARING THE SAME}

The present invention relates to a multilayer polyimide film having excellent dimensional stability and adhesion, and a method for manufacturing the same. More specifically, it comprises a core part comprising a structure derived from at least 4,4'-diamino-2,2'-dimethylbiphenyl compound and a skin part comprising a structure derived from at least 3,5-diaminobenzoic acid compound, Provided are a multilayer polyimide film having a negative glass transition temperature (T _g ) of 360° C. or more, a skin portion having a glass transition temperature of 300° C. or more, and an adhesive strength of 1,000 gf/cm or more, and a method for manufacturing the same.

In addition, the multilayer polyimide film of the present invention may have a coefficient of thermal expansion (CTE) of 7.5 ppm or more and 11 ppm or less, and a molecular orientation ratio (MOR) difference of 0.005 or less.

In addition, the multilayer polyimide film of the present invention may have an elastic modulus of 6.8 GPa or more and 7.5 GPa or less, and a strength of 360 MPa or more and 440 MPa or less.

That is, the present invention is composed of a core layer having excellent dimensional stability in order to improve the balance of the full width of the multilayer polyimide film, and a skin layer containing 3,5-diaminobenzoic acid compound in order to secure adhesive strength. All of these provide excellent multilayer polyimide films.

Polyimide (PI) is a polymer material with thermal stability based on a rigid aromatic main chain. Based on the chemical stability of the imide ring, it has excellent mechanical strength, chemical resistance, weather resistance, and heat resistance.

In addition, due to its excellent electrical properties such as insulation properties and low dielectric constant, it is in the spotlight as a high-functional polymer material ranging from microelectronics to optical fields.

For example, in the field of microelectronics, due to the weight reduction and miniaturization of electronic products, thin circuit boards with a high degree of integration and flexibility are being actively developed. It is used as a protective film for thin circuit boards.

Such a thin circuit board generally has a structure in which a circuit including a metal foil is formed on a polyimide film, and such a thin circuit board is also referred to as a flexible metal clad laminate in a broad sense. It is sometimes referred to as Flexible Copper Clad Laminate (FCCL) in a narrow sense when using

As a method for manufacturing a flexible metal clad laminate, for example, (i) a casting method in which polyamic acid, which is a precursor of polyimide, is cast or coated on a metal foil and then imidized, (ii) by sputtering or plating A metallizing method in which a metal layer is provided directly on a polyimide film, and (iii) a lamination method in which a polyimide film and a metal foil are bonded by heat and pressure through a thermoplastic polyimide.

The double lamination method has an advantage in that the thickness range of the applicable metal foil is wider than that of the casting method, and the equipment cost is lower than that of the metallizing method. As an apparatus for laminating, a roll laminating apparatus or a double belt press apparatus for laminating continuously while feeding a roll-shaped material is used. Among the above, from a viewpoint of productivity, the hot roll lamination method using a hot roll lamination apparatus can be used more preferably.

However, in the case of a laminate, as described above, since a thermoplastic resin is used for adhesion between the polyimide film and the metal foil, in order to express the heat-sealability of the thermoplastic resin, the glass transition of the polyimide film is at 300°C or higher, in some cases. It is necessary to apply heat of 400°C or higher to the temperature (Tg) close to or higher than the polyimide film.

In general, it is known that the value of the storage modulus of a viscoelastic material such as a polyimide film is significantly reduced in a temperature range exceeding the glass transition temperature compared to the value of the storage modulus at room temperature.

That is, when lamination that requires a high temperature is performed, the storage modulus of the polyimide film at high temperature may be significantly lowered, and under the low storage modulus, the polyimide film becomes loose and the polyimide film does not exist in a flat form after lamination is finished. this is high In other words, in the case of a laminate, it can be said that the dimensional change of the polyimide film is relatively unstable.

Another thing to note is that the glass transition temperature of the polyimide film is significantly lower than the temperature during lamination. Specifically, in the above case, since the viscosity of the polyimide film is relatively high at the temperature at which lamination is performed, a relatively large dimensional change may be accompanied, and accordingly, there is a risk that the appearance quality of the polyimide film after lamination may be deteriorated. .

In addition, when the casting method is used, as a three-layer polyimide film for two-layer FPC, a method of manufacturing a three-layer polyimide film by coating and drying (imidizing) a polyamic acid solution on the surface of the polyimide film is mentioned. However, there are cases in which a process of manufacturing a polyimide film, a process of applying a polyamic acid solution on the surface of the polyimide film, and drying (imidization) are required, and there are a plurality of processes, leading to an increase in cost. There was (for example, refer patent document 1).

In addition, as a three-layer polyimide film for two-layer FPC, a method of producing a three-layer polyimide film by simultaneously casting a polyamic acid solution in multiple layers on a support, drying it, peeling it from the support, and subjecting it to heat treatment However, there were cases where the polyimide layer in direct contact with the support was partially affixed on the support, or a difference in peel strength occurred between the polyimide layer in contact with the support and the polyimide layer on the opposite side (e.g. For example, refer to Patent Documents 2 and 3).

Accordingly, there is a high need for a technology capable of significantly improving fairness by solving the above problems.

1. Japanese Patent Laid-Open No. 9-116254 (published on May 2, 1997) 2. Japanese Patent Application Laid-Open No. 7-214637 (published on August 15, 1995) 3. Japanese Patent Laid-Open No. 10-138318 (published on May 26, 1998)

An object according to one aspect of the present invention is to provide a multilayer polyimide film having excellent dimensional stability and adhesion and an effective manufacturing method thereof, specifically, determining the type of dianhydride monomer, the type of the diamine monomer, and their compounding ratio, In addition, due to the multi-layer composition of polyimide resins of different compositions, it has a desired glass transition temperature, has a high storage modulus at high temperatures, and has excellent adhesion while minimizing dimensional change by relieving thermal stress. To provide a multilayer polyimide.

Another object of the present invention is to provide a flexible copper clad laminate having a relatively small dimensional change including a multilayer polyimide film satisfying desired physical properties and thus having excellent appearance quality.

Accordingly, the present invention has a practical object to provide specific examples thereof.

In order to achieve the above object, the present invention provides 4,4'-diamino-2,2'-dimethylbiphenyl (4,4'-Diamino-2,2'-dimethylbiphenyl; m-Tolidine), paraphenylene Diamine-derived structure and pyromellitic dianhydride containing at least one selected from the group consisting of diamine (p-phenylenediamine; p-PDA) and 4,4'-oxydianiline (ODA) (pyromellitic dianhydride; PMDA) and 3,3′,4,4′-biphenyltetracarboxylic dianhydride (3,3′,4,4′-Biphenyltetracarboxylic dianhydride; BPDA) at least one selected from the group consisting of It exists in contact with at least one outer surface of the core part and the core part including a dianhydride-derived structure, including 3,5-diaminobenzoic acid (3,5-diaminobenzoic acid; 3.5-DABA), paraphenylenediamine Diamine-derived structures including (p-phenylenediamine; p-PDA) and 4,4'-oxydianiline (ODA) and pyromellitic dianhydride (PMDA), 3, 3′,4,4′-biphenyltetracarboxylic dianhydride (3,3′,4,4′-Biphenyltetracarboxylic dianhydride; BPDA) and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride Ride (3,3',4,4'-Benzophenonetetracarboxylic dianhydride; BTDA) including a skin portion comprising a dianhydride-derived structure comprising at least one selected from the group consisting of, the glass transition temperature of the core portion (T _g ) Provided is a multilayer polyimide film having a temperature of 360° C. or more, a glass transition temperature of a skin portion of 300° C. or more, and an adhesive strength of 1,000 gf/cm or more.

The thickness of the core part and the skin part may be present in a ratio of 6:4 to 9:1, and more preferably, the glass transition temperature of the skin part is preferably 300°C to 380°C, and the adhesive strength may be 1,000 gf/cm or more. In addition, the skin portion may provide a multilayer polyimide film present on both surfaces of the core portion by contacting at least one outer surface of the core portion and the opposite surface of the outer surface, respectively.

Another embodiment of the present invention is a diamine comprising at least one selected from the group consisting of 4,4'-diamino-2,2'-dimethylbiphenyl, paraphenylenediamine and 4,4'-oxydianiline A preparation prepared by polymerizing a dianhydride monomer comprising at least one selected from the group consisting of a monomer and pyromellitic dianhydride and 3,3′,4,4′-biphenyltetracarboxylicdianhydride in a solvent. 1 obtaining a polyamic acid; preparing a first polyimide prepared by imidizing the first polyamic acid; Diamine monomers including 3,5-diaminobenzoic acid, paraphenylenediamine and 4,4'-oxydianiline and pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylicdian To obtain a second polyamic acid prepared by polymerizing a dianhydride monomer comprising at least one selected from the group consisting of hydride and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride in a solvent step; preparing a second polyimide prepared by imidizing a second polyamic acid; A method of manufacturing a multilayer polyimide film comprising the; co-extrusion by providing a second discharging unit discharging a second polyimide so as to contact the first polyimide on at least one side of the first discharging unit discharging the first polyimide provides

In addition, another embodiment of the present invention includes at least one selected from the group consisting of 4,4'-diamino-2,2'-dimethylbiphenyl, paraphenylenediamine and 4,4'-oxydianiline Prepared by polymerizing a dianhydride monomer comprising at least one selected from the group consisting of a diamine monomer and pyromellitic dianhydride and 3,3′,4,4′-biphenyltetracarboxylic dianhydride in a solvent. obtaining a first polyamic acid; Diamine monomers including 3,5-diaminobenzoic acid, paraphenylenediamine and 4,4'-oxydianiline and pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylicdian To obtain a second polyamic acid prepared by polymerizing a dianhydride monomer comprising at least one selected from the group consisting of hydride and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride in a solvent step; Co-extrusion with a second discharging unit discharging a second polyamic acid so as to contact the first polyamic acid on at least one side of the first discharging unit discharging the first polyamic acid; It provides a method of manufacturing a multilayer polyimide film comprising; imidizing the co-extruded polyamic acid. Preferably, the step of co-extrusion and the step of imidizing the co-extruded polyamic acid may be performed simultaneously.

The multilayer polyimide film has an adhesive strength of 1,000 gf/cm or more, a glass transition temperature (T _g ) of the core part prepared from the first polyamic acid is 360° C. or more, and the glass transition temperature (T g ) of the skin part prepared from the second polyamic acid _g ) is characterized in that 300 ℃ or more.

The first discharge unit is located on the opposite side of the surface in contact with the second discharge unit, and a third discharge unit for discharging the second polyimide or the second polyamic acid so as to be in contact with the other surface of the first polyimide or the first polyamic acid is further may include

Each of the first polyamic acid and the second polyamic acid may further include any one selected from the group consisting of an imidization catalyst, a dehydrating agent, a curing agent, a filler, and an additive in which one or more thereof is mixed.

Another embodiment of the present invention provides a flexible metal foil laminate including a multilayer polyimide film and an electrically conductive metal foil.

Another embodiment of the present invention provides an electronic component including a flexible metal clad laminate.

As described above, the present invention is due to the combination of specific dianhydride monomers, diamine monomers, and specific mixing ratios thereof, and by laminating polyimide films of different compositions, while having excellent adhesion, desired glass It is possible to provide a multilayer polyimide film having a transition temperature, a high storage modulus at high temperature, and in addition, a multilayer polyimide film excellent in dimensional stability and an effective manufacturing method thereof by relieving thermal stress to improve the shrinkage ratio deviation in each width direction.

The present invention can also provide a flexible copper clad laminate having excellent appearance quality, including the multilayer polyimide film as described above.

Hereinafter, through specific examples of the invention, the operation and effect of the invention will be described in more detail. However, these embodiments are merely presented as an example of the invention, and the scope of the invention is not defined thereby.

Hereinafter, embodiments of the present invention will be described in more detail in the order of "multilayer polyimide film", "method for manufacturing multilayer polyimide film" and "flexible metal clad laminate" according to the present invention.

Prior to this, the terms or words used in the present specification and claims should not be construed as being limited to their ordinary or dictionary meanings, and the inventor should properly understand the concept of the term in order to best describe his invention. Based on the principle that it can be defined, it should be interpreted as meaning and concept consistent with the technical idea of the present invention.

Accordingly, since the configuration of the embodiments described in the present specification is only one of the most preferred embodiments of the present invention and does not represent all the technical spirit of the present invention, various equivalents and modifications that can be substituted for them at the time of the present application It should be understood that examples may exist.

In this specification, the singular expression includes the plural expression unless the context clearly dictates otherwise. In the present specification, terms such as "comprise", "comprising" or "have" are intended to designate the presence of an embodied feature, number, step, element, or a combination thereof, but one or more other features or It should be understood that it does not preclude the possibility of the presence or addition of numbers, steps, elements, or combinations thereof.

Multilayer Polyimide Film

The multilayer polyimide film according to the present invention comprises:

4,4′-diamino-2,2′-dimethylbiphenyl (4,4′-Diamino-2,2′-dimethylbiphenyl; m-Tolidine), paraphenylenediamine (p-phenylenediamine; p-PDA) and A diamine-derived structure comprising at least one selected from the group consisting of 4,4'-oxydianiline (ODA) and pyromellitic dianhydride (PMDA) and 3,3' , 4,4'-biphenyltetracarboxylic dianhydride (3,3',4,4'-Biphenyltetracarboxylic dianhydride; BPDA) core comprising a dianhydride-derived structure comprising at least one selected from the group consisting of part; and

It exists in contact with at least one outer surface of the core part, 3,5-diaminobenzoic acid (3.5-DABA), paraphenylenediamine (p-phenylenediamine; p-PDA) and 4,4' -Diamine-derived structure including oxydianiline (4,4'-oxydianiline; ODA) and pyromellitic dianhydride (PMDA), 3,3',4,4'-biphenyltetracarboxylicdian Hydride (3,3′,4,4′-Biphenyltetracarboxylic dianhydride; BPDA) and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (3,3′,4,4′-Benzophenonetetracarboxylic dianhydride) ; BTDA) including a skin portion including a dianhydride-derived structure comprising at least one selected from the group consisting of.

The skin part is present on at least one outer surface of the core part and may exist in the form of a two-layer film, more preferably in a form in contact with one outer surface of the core part and the rear surface of the outer surface, that is, at least of the core part. It may exist in the form of a 3-layer film which exists in contact with the skin part on both outer surfaces.

The thickness of the core part and the skin part may be present in a ratio of 6:4 to 9:1. When the thickness of the core part is less than 6 parts or exceeds 9 parts, dimensional stability may be deteriorated, and when the thickness of the skin part is less than 1 part or exceeds 4 parts, the adhesive strength characteristics may be reduced.

As an embodiment of the present invention for the multilayer polyimide film, each dianhydride monomer, diamine monomer, and mixing ratio thereof constituting the core part and the skin part will be described in detail through the following non-limiting examples.

<Diamine Monomer>

The diamine monomer that can be used in the present invention is 4,4′-diamino-2,2′-dimethylbiphenyl (4,4′-Diamino-2,2′-dimethylbiphenyl; m-Tolidine), 3,5-dia Minobenzoic acid (3,5-diaminobenzoic acid; 3.5-DABA), 4,4'-oxydianiline (4,4'-oxydianiline; ODA), 3,4'-oxydianiline (3,4'-oxydianiline) , 4,4-diaminobiphenyl-3,3-tetracarboxylic acid (4,4-diaminobiphenyl-3,3-tetracarboxylic acid; DATA), paraphenylenediamine (p-phenylenediamine; p-PDA), m -Phenylenediamine (m-PDA), p-methylenediamine (p-methylenediamine; p-MDA), metamethylenediamine (m-methylenediamine; m-MDA), and can be selected from the group of mixtures of one or more thereof have.

In a preferred embodiment of the present invention, the diamine monomer constituting the core part is selected from the group consisting of 4,4'-diamino-2,2'-dimethylbiphenyl, paraphenylenediamine and 4,4'-oxydianiline. It may include more than one species. When all of these three diamine compound-derived structures are included, the glass transition temperature (T _g ) characteristic of the polyimide film is expressed at 360° C. or higher, which is preferable for manufacturing a core part having high dimensional stability.

More preferably, the diamine monomer constituting the core part of the present invention may be paraphenylenediamine and 4,4'-oxydianiline.

When the diamine monomer of the core part consists of only paraphenylenediamine and 4,4'-oxydianiline, the content of paraphenylenediamine is 60 mol% or more based on 100 mol% of the total diamine monomer content of the core part 80 mol% or less, and the content of 4,4'-oxydianiline may be 20 mol% or more and 40 mol% or less.

In another preferred embodiment of the present invention, the diamine monomer constituting the skin part may include 3,5-diaminobenzoic acid, paraphenylenediamine and 4,4′-oxydianiline. In order to improve the adhesion of the polyimide, it is advantageous to include a monomer including a hydrophilic functional group, such as 3,5-diaminobenzoic acid. In addition, when all three diamine compound-derived structures are included as described above, the glass transition temperature of the skin part can be formed at 300 ° C. or higher, preferably 300 ° C. to 380 ° C. while the adhesive strength is excellent at 1,000 gf / cm or more. In the process, it is possible to improve the shrinkage rate deviation by location due to the glass transition temperature.

In addition, the content of 3,5-diaminobenzoic acid is 3 mol% or more and 15 mol% or less, and the content of para-phenylenediamine is 60 mol% or more, based on 100 mol% of the total content of the diamine monomer in the skin part of the present invention 80 mol% or less, and the content of 4,4'-oxydianiline may be 15 mol% or more and 35 mol% or less.

<Dianhydride Monomer>

The dianhydride monomer that can be used in the present invention is 3,3′,4,4′-biphenyltetracarboxylic dianhydride (3,3′,4,4′-Biphenyltetracarboxylic dianhydride; BPDA), pyromellitic dianhydride (pyromellitic dianhydride; PMDA), 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (3,3′,4,4′-Benzophenonetetracarboxylic dianhydride; BTDA), oxydiphthalic anhydride It may be selected from the group of oxydiphthalic anhydride (ODPA) and mixtures of one or more thereof.

In a preferred embodiment of the present invention, the dianhydride monomer constituting the core part is at least one selected from the group consisting of pyromellitic dianhydride and 3,3′,4,4′-biphenyltetracarboxylicdianhydride. may include

When the dianhydride monomer of the core part consists of pyromellitic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride, the total content of the dianhydride monomer of the core part is 100 mol% Based on the pyromellitic dianhydride content is 40 mol% or more and 60 mol% or less, and the content of 3,3',4,4'-biphenyltetracarboxylic dianhydride is 40 mol% or more and 60 mol% or more mol% or less.

In another preferred embodiment of the present invention, the dianhydride monomer constituting the skin part is pyromellitic dianhydride, 3,3′,4,4′-biphenyltetracarboxylic dianhydride and 3,3′,4, It may include one or more selected from the group consisting of 4'-benzophenone tetracarboxylic dianhydride.

More preferably, the dianhydride monomer constituting the skin part of the present invention is 3,3′,4,4′-biphenyltetracarboxylic dianhydride and 3,3′,4,4′-benzophenonetetracarboxylic It may be a dianhydride.

When the dianhydride monomer of the skin part consists only of 3,3',4,4'-biphenyltetracarboxylic dianhydride and 3,3',4,4'-benzophenonetetracarboxylic dianhydride, the Based on 100 mol% of the total content of the dianhydride monomer in the skin part, the content of 3,3',4,4'-biphenyltetracarboxylic dianhydride is 90 mol% or more and 99 mol% or less, and 3, The content of 3',4,4'-benzophenonetetracarboxylic dianhydride may be 1 mol% or more and 10 mol% or less.

In addition, such a multilayer polyimide film,

(a) the glass transition temperature (T _g ) of the core part is 360 ℃ or more, the glass transition temperature of the skin part is 300 ℃ or more, preferably 300 ℃ to 380 ℃,

(b) the adhesion is at least 1,000 gf/cm, preferably at least 1,400 gf/cm,

(c) a CTE of 7.5 ppm or more and 11 ppm or less, and a MOR difference of 0.005 or less,

(d) The elastic modulus is 6.8 GPa or more and 7.5 GPa or less, and the strength is 360 MPa or more and 440 MPa or less.

In this regard, in the case of a multilayer polyimide film that satisfies all of the above conditions, it can be used as a substrate film for flexible metal clad laminate, an insulating film, a protective film, etc. Stable circuit implementation may be possible by minimizing the problem of dimensional change caused by this or the lifting problem caused by a decrease in adhesive strength.

The multilayer polyimide film satisfying all of these conditions is a novel polyimide film not known until now, and the above conditions will be described in detail below.

<Glass transition temperature>

In the present invention, the glass transition temperature can be obtained from the storage modulus and the loss modulus measured by a dynamic viscoelasticity measuring device (DMA), and in detail, the inflection point (top peak) of tan δ, which is a value obtained by dividing the calculated loss modulus by the storage modulus It can be calculated as the glass transition temperature. Since the glass transition temperature is related to the heat resistance of the polyimide film, it is preferable that the glass transition temperature be higher in order to improve dimensional stability at high temperature when applied to a copper clad laminate.

However, a flexible copper clad laminate (Flexible Copper Clad) is used by coating a thermoplastic polyimide (TPI) on a core polyimide film, or by using a conventional multi-layer polyimide film manufactured by laminating a TPI film and a core film respectively. Laminate: FCCL), due to the glass transition temperature (360° C. or higher) of the core polyimide, distortion and dimensional balance problems may occur due to variations in shrinkage by location and width direction during the film forming process. Due to this, deviations may occur in the mechanical properties of the multilayer polyimide film and the coefficient of thermal expansion (CTE) between the layers.

In addition, it is difficult to reconcile the highest level of glass transition temperature with physical properties such as dielectric constant, dielectric loss factor, or adhesive strength in multilayer polyimide films. This is because improving the glass transition temperature of the polyimide film is due to the chemical stability of the imide group. , since the imide group exhibits polarity, the moisture absorptivity may be increased, and the improvement of the moisture absorptivity is expected to be related to the weakening of the dielectric properties or adhesive properties.

However, when the glass transition temperature of the polyimide film is simply increased to solve this problem, there may be a problem that the adhesive strength is weakened. In addition, when a skin layer or an adhesive layer having adhesive properties is formed between the core layer of the multilayer polyimide film and the metal foil, the problem of different shrinkage rates due to the difference in coefficients of thermal expansion between the skin layer and the core layer should also be considered.

Accordingly, in order to overcome this problem, the present invention provides a polyimide film in which both the glass transition temperature and the adhesive strength are compatible at a desirable level. Specifically, the polyimide film according to the present invention controls the glass transition temperature of the polyimide resin constituting the core part and the skin part, respectively, and co-extrudes them to form TPI on the existing low glass transition temperature core polyimide film. Adhesion and dimensional stability may be improved compared to the case of a multilayer polyimide film prepared by coating or laminating.

Therefore, in the multilayer polyimide film according to a preferred embodiment of the present invention, the glass transition temperature (T _g ) of the core part may be 360° C. or more, and the glass transition temperature of the skin part may be 300° C. or more, and preferably, the glass transition temperature of the skin part is It may be 300 °C or higher to 380 °C or lower.

When the glass transition temperature of the resin constituting the multilayer polyimide film of the core part or the skin part is lower than the above range, when the multilayer polyimide film is manufactured through co-extrusion, the viscosity of the polyimide film is relatively high. Mold control can be difficult. In addition, when the FCCL is manufactured by the thermal lamination method, etc., the polyimide film becomes excessively loose, and after the film forming process is finished, a large dimensional change such as appearance defects such as swells or wrinkles is formed on the surface of the polyimide film may be accompanied. This is a cause of deterioration of the appearance quality, and it is not preferable because the effect of improving the dimensional stability according to the improvement of the shrinkage rate deviation may be halved. In addition, after the application of heat by such a thermal lamination method, that is, even at the time of completion of adhesion, the softening of the core layer or skin layer of the polyimide film is initiated due to the residual heat inherent in the polyimide film, causing the dimensional change to gradually increase. may be

On the other hand, when the glass transition temperature of the polyimide resin constituting the skin part is higher than the above range, since the temperature at which the adhesive layer is softened is too high, a decrease in adhesive strength may be caused due to an increase in the glass transition temperature when manufacturing FCCL, etc. It is not preferable because the stress is not sufficiently relieved and the difference in heat shrinkage can also cause a large dimensional deviation. That is, when it is out of the above range, the physical properties of the multilayer polyimide film may be deteriorated outside the range in which adhesive strength and dimensional stability are properly maintained.

<Adhesiveness>

The adhesive force may include both the interlayer adhesive force of the core part and the skin part of the multilayer polyimide film, the adhesive force between the same or different material layers in contact with the polyimide film, preferably the adhesive force with the electrically conductive metal foil.

As an embodiment of the present invention, a peel test method through Innoflex adhesion was used as a method for measuring adhesive strength. Place Innoflex (1mil, Epoxy type, manufactured by Innox) on a flexible metal clad laminate in which copper foil is laminated on both sides of the multilayer polyimide (PI) film or multilayer polyimide film of the present invention. After heating to a temperature of 10Kgf/cm ^{2 for} 30 minutes, thermocompression bonding was performed. After cutting the film to a width of 13 mm, a 180° peel test was performed.

The multilayer polyimide film prepared according to an embodiment of the present invention preferably has an adhesive strength of 700 gf/cm or more, preferably 1,000 gf/cm or more, and even more preferably 1,400 gf/cm or more.

Method for manufacturing multilayer polyimide film

In order to obtain the multilayer polyimide film of the present invention,

(1) preparing a polyamic acid solution obtained by adding a diamine monomer and a dianhydride monomer to an organic polar solvent, and adding a diamine monomer and a dianhydride monomer to an organic polar solvent, and imidizing it A co-extrusion manufacturing method in which the polyimide of each of the core part and the skin part is filled in a resin storage tank and discharged is preferred.

However, in some cases, (2) a co-extrusion manufacturing method in which the polyamic acid solution is filled and discharged into the polyamic acid solution storage tank of the core part and the skin part, respectively, or imidized at the same time as the discharge may be used, (3) the core It is also possible to use a coextrusion-flexible coating manufacturing method in which the negative polyamic acid is imidized and cast while simultaneously discharging the polyamic acid solution in the skin portion.

First, the multilayer polyimide film of the present invention is obtained from the first and second polyamic acid solutions, which are precursors of the first and second polyimides constituting the core part and the skin part, respectively.

The polyamic acid solution is prepared by dissolving a monomer compound formulated so that the aromatic or aliphatic diamine monomer and the aromatic or aliphatic dianhydride monomer in substantially equimolar amounts are dissolved in an organic solvent, and the resulting polyamic acid organic solvent solution is subjected to a controlled temperature condition with the dianhydride monomer. and stirring until the polymerization of the diamine monomer is completed.

Preferably, the first polyamic acid solution constituting the core part is one selected from the group consisting of 4,4'-diamino-2,2'-dimethylbiphenyl, paraphenylenediamine and 4,4'-oxydianiline. Diamine-derived monomers containing the above and dianhydride-derived monomers comprising at least one selected from the group consisting of pyromellitic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride It can be prepared by polymerization in a solvent.

In addition, the second polyamic acid solution constituting the skin part is a diamine-derived monomer including 3,5-diaminobenzoic acid, paraphenylenediamine and 4,4'-oxydianiline, pyromellitic dianhydride, 3,3 A dianhydride-derived monomer comprising at least one selected from the group consisting of ',4,4'-biphenyltetracarboxylic dianhydride and 3,3',4,4'-benzophenone tetracarboxylic dianhydride It may be preferable to prepare by polymerization in a solvent.

The polyamic acid solution is usually obtained at a concentration of 5 to 35% by weight, preferably 10 to 30% by weight of the solid content, and when the concentration is in this range, the polyamic acid solution obtains an appropriate molecular weight and solution viscosity.

The solvent for synthesizing the polyamic acid solution is not particularly limited, and any solvent may be used as long as it dissolves the polyamic acid. Specifically, the solvent may be an organic polar solvent, and specifically, aprotic polarity. It may be an aprotic polar solvent, preferably an amide-based solvent. For example, N,N'-dimethylformamide (DMF), N,N'-dimethylacetamide, N-methyl-pyrrolidone (NMP), gamma butyrolactone (GBL), Diglyme It may be one or more selected from the group consisting of, but is not limited thereto, and may be used alone or in combination of two or more as needed. In one example, the solvent may preferably be N,N-dimethylformamide and N,N-dimethylacetamide.

In the production step of the polyamic acid, all the monomers may be added at once, or each monomer may be sequentially added, depending on the type of the monomer and the desired physical properties of the polyimide film. In this case, partial polymerization between the monomers may occur.

In addition, in the polyamic acid solution manufacturing process, a filler may be added for the purpose of improving various properties of the film, such as sliding properties, thermal conductivity, conductivity, corona resistance, and loop hardness.

The filler to be added is not particularly limited, but preferred examples thereof include silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, mica, and the like.

The particle size of the filler is not particularly limited, and may be determined according to the film properties to be modified and the type of filler to be added.

In general, the average particle diameter may be 0.05 to 100 μm, preferably 0.1 to 75 μm, more preferably 0.1 to 50 μm, particularly preferably 0.1 to 25 μm.

When the particle size is less than this range, the modifying effect becomes difficult to appear, and when the particle size exceeds this range, the surface properties may be greatly impaired or the mechanical properties may be greatly reduced.

In addition, the addition amount of a filler is not specifically limited also, It can determine by the film characteristic to be modified|reformed, a filler particle size, etc.

In general, the amount of the filler added may be 0.01 to 100 parts by weight, preferably 0.01 to 90 parts by weight, and more preferably 0.02 to 80 parts by weight based on 100 parts by weight of polyimide.

When the filler addition amount is less than this range, the modifying effect by the filler is difficult to appear, and when it exceeds this range, the mechanical properties of the film may be greatly impaired.

The method of adding a filler is not specifically limited, Any well-known method can also be used.

The first and second polyamic acid solutions prepared as described above are imidized after co-extrusion in a solution state or at the same time as the co-extrusion process to prepare a multilayer polyimide, or imidized with the first and second polyimides, respectively. The multilayer polyimide can be manufactured by filling and co-extruding each resin in a resin storage tank to form a core part and a skin part.

For a method of producing polyimide by imidizing a polyamic acid solution, a conventionally known method can be used, and specifically, a thermal imidization method, a chemical imidization method, or a combination of a thermal imidization method and a chemical imidization method. A complex imidation method is mentioned.

The thermal imidization method is a method of imidizing a polyamic acid solution only by heating without using a catalyst such as a dehydrating agent, and the polyamic acid is gradually heated in a temperature range of 40°C to 400°C, preferably 40°C to 300°C. This is a method for obtaining a polyimide resin imidized with polyamic acid by heat treatment for 1 to 8 hours.

Chemical imidization is a method of accelerating imidization of a polyamic acid solution using a catalyst such as a dehydrating agent and/or an imidizing agent.

As an example of the chemical imidization method, a composition obtained by mixing additives such as a dehydrating agent, imidization catalyst, chemical conversion agent, and curing agent in a polyamic acid solution at a low temperature is mixed with a support such as a glass plate, aluminum foil, endless stainless belt, or stainless drum. Partial curing and / by activating the dehydrating agent and imidizing agent by applying to the (casting), heat treatment at a temperature range of 40 ° C to 300 ° C, preferably 80 ° C to 200 ° C, more preferably 100 ° C to 180 ° C or dried to form a gel, which is an intermediate having self-supporting properties. Thereafter, it is preferable to include a step of peeling the gel from the support and a step of further heating the gel to imidize and dry the remaining amic acid (hereinafter also referred to as a “calcination process”).

In the composite imidization method, a dehydrating agent and an imidization catalyst are added to a polyamic acid solution, and then heated at 80 to 200° C., preferably 100 to 180° C., partially cured and dried, and then heated at 200 to 400° C. for 5 to 400 seconds. By doing so, polyimide resin can be obtained.

Accordingly, the first polyamic acid and the second polyamic acid of the present invention are each composed of an imidization catalyst, a dehydrating agent, a curing agent, and an additive in which one or more thereof is mixed to facilitate thermal imidization, chemical imidization, or complex imidization method. It may further include any one selected from.

The dehydrating agent is, for example, an aliphatic acid anhydride, an aromatic acid anhydride, a N,N'-dialkylcarbodiimide, a halogenated lower aliphatic, a halogenated lower fatty acid anhydride, an arylphosphonic acid dihalide, and a thionyl halide, or two thereof. mixtures of more than one species. Among them, aliphatic acid anhydrides, such as acetic anhydride, propionic anhydride, and lactic anhydride, or a mixture of two or more thereof can be preferably used from the viewpoints of availability and cost.

It is preferable to exist in the range of 0.5-5 mol with respect to 1 mol of amic acid groups in a polyamic acid, and, as for the addition amount of a dehydrating agent, it is more preferable to exist in the range of 1.0-4 mol.

Moreover, as an imidation agent, an aliphatic tertiary amine, an aromatic tertiary amine, a heterocyclic tertiary amine, etc. are used, for example. Among them, those selected from heterocyclic tertiary amines are particularly preferably used from the viewpoint of reactivity as a catalyst. Specifically, quinoline, isoquinoline, β-picoline, pyridine and the like are preferably used.

Moreover, it is preferable to exist in the range of 0.05-3 mol with respect to 1 mol of amic acid groups in a polyamic acid, and, as for the addition amount of an imidation agent, it is especially preferable to exist in the range of 0.2-2 mol.

When the dehydrating agent and the imidizing agent are less than the above range, the chemical imidization is insufficient, and there may be cases where the dehydrating agent and the imidizing agent are less than the above range, resulting in a fracture during firing or a decrease in mechanical strength.

Moreover, when these amounts exceed the said range, since imidation advances rapidly and casting into a film form may become difficult, it is unpreferable.

In the co-extrusion method, a first polyimide-based resin solution or a precursor thereof, a first polyamic acid solution, and a second polyimide-based resin solution, or a second polyamic acid solution, a precursor thereof, are ejected onto a casting belt using a multi-layer co-extrusion device. This is a method of manufacturing a multilayer polyimide film by forming a multilayer extruded film by doing so, drying it by heating and curing it. In the co-extrusion method, a first polyimide-based resin solution or a precursor thereof, a first polyamic acid solution, and a second polyimide-based resin solution, or a second polyamic acid solution, a precursor thereof, are mixed using a multi-layer co-extrusion apparatus to a casting belt. A multilayer polyimide film can also be manufactured by forming a multilayer extruded film by discharging and imidizing it by heating and drying and curing at the same time. The co-extrusion method has high productivity, and different polyimides between interfaces are mixed to ensure high interfacial adhesion reliability.

The multilayer coextrusion apparatus for manufacturing a multilayer polyimide film of the present invention includes a first resin reservoir for storing a first polyimide or first polyamic acid solution, and a second resin for storing a second polyimide or second polyamic acid solution. It may include a storage tank, a central layer flow path connected to the first resin storage tank, an outer layer flow path connected to the second resin storage tank, a first discharge part connected to the central layer flow path, and a second discharge part connected to the outer layer flow path.

The second polyimide or second polyamic acid solution discharged from the outer layer flow path and the second discharge unit is disposed to contact the first polyimide or first polyamic acid solution discharged from at least one side of the first discharge unit connected to the central layer flow path. Therefore, the outer layer flow path and the second discharge unit are located close to at least one surface of the central layer flow path and the first discharge unit, and a two-layer coextrusion film may be finally formed.

In addition, the present invention more preferably a three-layer co-extrusion layer including a central layer flow path connected to the first discharge unit and an outer layer flow path connected to the second discharge unit and the third discharge unit, respectively, located on both sides of the central layer flow path ( It may be a die forming a 3-layer coextrusion film). The third discharge unit is located on the rear surface of the surface in which the first discharge unit is in contact with the second discharge unit, and the second polyimide or the second polyamic acid discharged from the second discharge unit is a first polyimide or The second polyimide or the second polyamic acid may be discharged so as to be in contact with another surface of the surface in contact with the first polyamic acid. That is, preferably, the second polyimide or the second polyamic acid forming the skin portion may be positioned on both outer surfaces of the first polyimide or the first polyamic acid forming the core portion.

In addition, according to an embodiment of the present invention, since a heating or curing device is provided together in the first to third discharge units, the discharge material is injected and imidization is performed at the same time to form a multi-layered co-extrusion product.

The multilayer co-extrusion apparatus of the present invention can control the discharge and co-extrusion flow rates of the polyimide resin or polyamic acid solution discharged from the first discharge unit, the second discharge unit and/or the third discharge unit, respectively. The thickness ratio between the polyimide layer of the core part and the polyimide layer of the skin part can be adjusted by adjusting the solvent content, the polymer solid content, etc. included in the resin and the solution.

The thickness of the core part and the skin part is preferably formed in a ratio of 6:4 to 9:1 in order to improve dimensional stability and adhesion of the multilayer polyimide film.

The multi-layer polyimide film produced through the multi-layer co-extrusion device, if necessary, introduces a temperature control device including a cooling device and a heating device for each of the first polyimide resin and the second polyimide resin solution, before and after input of the co-extrusion device Viscosity can be adjusted.

The multilayer extrudate film discharged through the multilayer co-extrusion device may be heated and dried to form a multilayer polyimide film, and may be further imidized as necessary to prepare a multilayer polyimide film.

In addition, the present invention may further comprise the step of expanding and casting the multi-layer extrudate flowing out from the co-extrusion device.

Flexible metal clad laminate

The present invention provides a flexible metal clad laminate comprising the above-described multilayer polyimide film and an electrically conductive metal foil.

The metal foil to be used is not particularly limited, but when the flexible metal clad laminate of the present invention is used for electronic devices or electrical devices, for example, copper or a copper alloy, stainless steel or an alloy thereof, nickel or a nickel alloy (alloy 42) also included), may be a metal foil comprising aluminum or an aluminum alloy.

In general flexible metal clad laminates, copper foils such as rolled copper foil and electrolytic copper foil are often used, and they can be preferably used in the present invention as well.

Flexible copper clad laminate (FCCL), which uses polyimide film as an insulating support, is a three-layer structure (Adhesive type) FCCL in which copper foil is laminated using an adhesive on a polyimide film, and a thermoplastic polyimide (Thermoplastic) instead of using an adhesive. It can be divided into FCCL having a two-layer structure (TPI adhesive type) in which copper foil is laminated by using a polyimide: TPI coating layer to impart adhesion.

Accordingly, the surface of these metal foils or polyimide films may be further coated with a rust preventive layer, a heat resistant layer, a coating layer, or an adhesive layer.

In the present invention, the thickness of the metal foil is not particularly limited, and may have a thickness capable of exhibiting a sufficient function depending on the use thereof.

In the flexible metal clad laminate according to the present invention, a metal foil is laminated on one side of the multilayer polyimide film, or an adhesive layer containing a thermoplastic polyimide is added to one side of the multilayer polyimide film, and the metal foil is attached to the adhesive layer It may have a laminated structure in the state.

The present invention also provides an electronic component including a flexible metal clad laminate as an electrical signal transmission circuit. The electrical signal transmission circuit may be an electronic component that transmits a signal at a high frequency of at least 2 GHz, specifically, a high frequency of at least 5 GHz, and more specifically, a high frequency of at least 10 GHz. The electronic component may be, for example, a communication circuit for a portable terminal, a communication circuit for a computer, or a communication circuit for aerospace, but is not limited thereto.

manufacturing example

Preparation Example 1: Preparation of the core part (first composition)

Put 198.23 kg of DMF into a 300 L reactor at 25 ℃ and nitrogen atmosphere, sequentially dissolve p-PPA and ODA at the desired composition ratio, react 16.87 kg of BPDA and 11.79 kg of PMDA, and then add 7.53 kg of 10% PMDA solution in divided portions While controlling the viscosity, a polyamic acid solution for a core having a viscosity of about 200,000 cP was obtained.

Preparation Example 2: Preparation of skin part (second composition)

Put 155.49 kg of DMF into a 300 L reactor at 25 ° C and nitrogen atmosphere, and sequentially dissolve 4.20 kg of ODA, 0.89 kg of DABA, and 6.17 kg of p-PDA, 23.19 kg of BPDA, and 9.25 kg of BTDA 10% solution divided After the viscosity was adjusted while being added to secure a viscosity of about 200,000 cP, 36 g of 0.5 μm spherical silica, 13 kg of isoquinoline and 67 kg of DMF were added to obtain a second polyamic acid solution of 12,000 cp.

Examples and Comparative Examples

The compositions and thicknesses (core part and skin part) of Examples and Comparative Examples corresponding to the multilayer polyimide film of the present invention are shown in Table 1 below.

<Example 1>

The first composition prepared in Preparation Example 1 was put into the first storage tank of the co-extrusion die, and the second composition prepared in Preparation Example 2 was added to the second storage tank.

Then, the second composition, the first composition, and the second composition were co-extruded on the endless belt in this order. At this time, when the first composition was extruded from the first storage tank, the mixture of isoquinoline, dimethylformamide and acetic anhydride was mixed from the catalyst storage tank.

A catalyst, a dehydrating agent, and a solvent mixture were mixed with the first polyamic acid.

Then, it was heat-treated at a temperature of about 150° C., which was heated again from 150° C. to 600° C. in a high-temperature tenter and cooled at 25° C. to obtain a 20 μm multilayer polyimide film having a skin part/core part/skin part structure. .

<Examples 2 to 4>

A multilayer polyimide film was prepared in the same manner as in Example 1, except that in Preparation Example 1, the composition of the first polyamic acid (particularly, the composition of the diamine monomer) or the core/skin thickness ratio was controlled.

<Comparative Example 1>

A precursor composition in which isoquinoline and acetic anhydride were mixed as catalysts to the first polyamic acid prepared in Preparation Example 1 was applied on a SUS plate. Thereafter, heat treatment was carried out in a temperature range of 100 °C to 200 °C, and after heating from 200 °C to 600 °C in a high-temperature tenter, the polyimide film was obtained by cooling at 25 °C.

<Comparative Example 2>

In Preparation Example 2, a precursor composition in which isoquinoline and acetic anhydride were mixed as a catalyst in the second polyamic acid was applied on a SUS plate. Thereafter, heat treatment was carried out in a temperature range of 100 °C to 200 °C, and after heating from 200 °C to 600 °C in a high-temperature tenter, the polyimide film was obtained by cooling at 25 °C.

Core part composition (mol%) Skin composition (mole%) Thickness (μm) dianhydride diamine dianhydride diamine core skin ^* Example 1 BPDA(50)
PMDA(50) ODA(30)
P-PDA(70) BPDA(97)
BTDA(3) ODA(25)
DABA(7)
P-PDA(68) 16 4 Example 2 BPDA(50)
PMDA(50) ODA(30)
P-PDA(70) BPDA(97)
BTDA(3) ODA(25)
DABA(7)
P-PDA(68) 15 5 Example 3 BPDA(50)
PMDA(50) ODA(35)
P-PDA(65) BPDA(97)
BTDA(3) ODA(25)
DABA(7)
P-PDA(68) 16 4 Example 4 BPDA(50)
PMDA(50) ODA(35)
P-PDA(65) BPDA(97)
BTDA(3) ODA(25)
DABA(7)
P-PDA(68) 15 5 Comparative Example 1 BPDA(50)
PMDA(50) ODA(30)
P-PDA(70) - - 20 - Comparative Example 2 BPDA(97)
BTDA(3) ODA(25)
DABA(7)
P-PDA(68) - - 20 -

*Skin thickness: the thickness of the entire skin

<Experimental Example: Evaluation of properties of polyimide film>

For property evaluation of the multilayer polyimide films prepared in Examples 1 to 4 and Comparative Examples 1 and 2, respectively, elastic modulus, strength, adhesive force, CTE, orientation analysis and adhesive force were measured using the following method, and the results are shown in the table below 2 is shown.

- CTE : With TA's Q400 TMA equipment, the diagonal B, which is orthogonal to the diagonal direction A on the side, was heated to 360 degrees at a heating rate of 10 degrees/min under 0.05N tension, cooled at a rate of 10 degrees/min, and then cooled to 10 at room temperature. The difference was calculated by measuring the coefficient of thermal expansion in the range of 100 to 200 degrees by increasing the temperature in degrees/minute.

- Orientation analysis : The MOR difference was calculated by measuring both sides and the center with the MOA-7015 equipment of OSI (Wang Prince Instrument).

- Modulus/Strength : It was measured using an Instron (Instron 3365SER) equipment according to ASTM D 882 measurement method.

- Adhesion : FCCL was manufactured by laminating at 180 degrees 30 MPa (pressure) for 60 minutes using Inox Bonding Sheet (BSH-MX-25MP) and Il vibration foil (ICS), and then measured at 200 mm/min with Instron 3365SER equipment. .

CTE
(ppm) Orientation analysis
(MOR difference) modulus of elasticity
(GPa) burglar
(MPa) adhesion
(gf/cm) Example 1 8 0.003 7.5 400 1400 Example 2 8.5 0.0035 7.1 380 1430 Example 3 8.8 0.004 7.1 390 1410 Example 4 9.2 0.0043 6.8 360 1450 Comparative Example 1 7 0.02 8 450 1000 Comparative Example 2 12 0.2 6.5 360 1450

From the results in Table 2, it was found that the Examples had excellent performance, particularly in orientation and adhesion. On the other hand, it can be seen that Comparative Examples 1 and 2 have poor at least one of these properties.

That is, all of Examples 1 to 4 of the present invention have an adhesive strength of 1,000 gf/cm or more (in particular, 1,400 gf/cm or more), a CTE of 7.5 ppm or more and 11 ppm or less, a MOR difference of 0.005 or less, an elastic modulus of 6.8 GPa or more and 7.5 GPa or less, and a strength of 360 The range of MPa or more and 440 MPa or less was satisfied.

On the other hand, Comparative Example 1 showed excellent CTE, elastic modulus and strength characteristics compared to Examples, but showed decreased measured values in MOR difference and adhesive strength characteristics, and Comparative Example 2 was excellent in adhesive strength characteristics compared to Examples, but CTE , the measured values of the MOR difference, CTE, and elastic modulus properties were decreased.

Although an embodiment of the present invention has been described above through the detailed description of the present invention, those of ordinary skill in the art to which the present invention pertains may make various applications and modifications within the scope of the present invention based on the above content. It will be possible.

Claims (17)

4,4′-diamino-2,2′-dimethylbiphenyl (4,4′-Diamino-2,2′-dimethylbiphenyl; m-Tolidine), paraphenylenediamine (p-phenylenediamine; p-PDA) and A diamine-derived structure comprising at least one selected from the group consisting of 4,4'-oxydianiline (ODA) and pyromellitic dianhydride (PMDA) and 3,3' A core comprising a dianhydride-derived structure comprising at least one selected from the group consisting of ,4,4′-biphenyltetracarboxylic dianhydride (3,3′,4,4′-Biphenyltetracarboxylic dianhydride; BPDA) part; and
Exists in contact with at least one outer surface of the core part, 3,5-diaminobenzoic acid (3.5-DABA), paraphenylenediamine (p-phenylenediamine; p-PDA) and 4,4 Diamine-derived structure including '-oxydianiline (4,4'-oxydianiline; ODA) and pyromellitic dianhydride (PMDA), 3,3',4,4'-biphenyltetracarboxylic Dianhydride (3,3′,4,4′-Biphenyltetracarboxylic dianhydride; BPDA) and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (3,3′,4,4′-Benzophenonetetracarboxylic A multilayer polyimide film comprising a; a skin portion comprising a dianhydride-derived structure comprising at least one selected from the group consisting of dianhydride; According to claim 1,
The core part has a diamine-derived structure including the paraphenylenediamine and the 4,4'-oxydianiline, the pyromellitic dianhydride and the 3,3',4,4'-biphenyltetracarboxylicdian and a dianhydride-derived structure comprising a hydride,
The skin part is the pyromellitic dianhydride, the 3,3′,4,4′-biphenyltetracarboxylic dianhydride and the 3,3′,4,4′-benzophenonetetracarboxylicdianhydride A multilayer polyimide film comprising a dianhydride-derived structure comprising a. 3. The method of claim 2,
The content of the pyromellitic dianhydride is 40 mol% or more and 60 mol% or less based on 100 mol% of the total content of the dianhydride monomer in the core part, and the 3,3',4,4'-biphenyltetra The content of carboxyl dianhydride is 40 mol% or more and 60 mol% or less,
The content of paraphenylenediamine is 60 mol% or more and 80 mol% or less based on 100 mol% of the total content of the diamine monomer in the core part, and the content of 4,4'-oxydianiline is 20 mol% or more and 40 mol% % or less,
Based on 100 mol% of the total content of the dianhydride monomer in the skin part, the content of the 3,3',4,4'-biphenyltetracarboxylic dianhydride is 90 mol% or more and 99 mol% or less, and the 3 , the content of 3',4,4'-benzophenone tetracarboxylic dianhydride is 1 mol% or more and 10 mol% or less,
The content of the 3,5-diaminobenzoic acid is 3 mol% or more and 15 mol% or less based on 100 mol% of the total content of the diamine monomer in the skin part, and the content of the paraphenylenediamine is 60 mol% or more and 80 mol% or less, and the content of the 4,4'-oxydianiline is 15 mol% or more and 35 mol% or less. According to claim 1,
The thickness of the core part and the skin part is a multilayer polyimide film present in a ratio of 6:4 to 9:1. According to claim 1,
The glass transition temperature (T _g ) of the core part is 360 ° C or more, the glass transition temperature of the skin part is 300 ° C or more, and the adhesive force of the multilayer polyimide film is 1,000 gf / cm or more. According to claim 1,
The multilayer polyimide film has a CTE of 7.5 ppm or more and 11 ppm or less, an MOR difference of 0.005 or less, an elastic modulus of 6.8 GPa or more and 7.5 GPa or less, and a strength of 360 MPa or more and 440 MPa or less. According to claim 1,
The skin portion is a multilayer polyimide film present on both surfaces of the core portion by contacting at least one outer surface of the core portion and an opposite surface of the outer surface, respectively. 4,4'-diamino-2,2'-dimethylbiphenyl, paraphenylenediamine, and diamine monomer containing at least one selected from the group consisting of 4,4'-oxydianiline and pyromellitic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride to obtain a first polyamic acid prepared by polymerizing a dianhydride monomer comprising at least one selected from the group consisting of dianhydride in a solvent;
preparing a first polyimide prepared by imidizing the first polyamic acid;
Diamine monomers including 3,5-diaminobenzoic acid, paraphenylenediamine and 4,4'-oxydianiline and pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylicdian To obtain a second polyamic acid prepared by polymerizing a dianhydride monomer comprising at least one selected from the group consisting of hydride and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride in a solvent step;
preparing a second polyimide prepared by imidizing the second polyamic acid;
A multilayer polyimide film comprising a; co-extrusion by providing a second discharging unit discharging the second polyimide so as to contact the first polyimide on at least one side of the first discharging unit discharging the first polyimide manufacturing method. 4,4'-diamino-2,2'-dimethylbiphenyl, paraphenylenediamine, and diamine monomer containing at least one selected from the group consisting of 4,4'-oxydianiline and pyromellitic dianhydride and 3,3',4,4'-biphenyltetracarboxylic dianhydride to obtain a first polyamic acid prepared by polymerizing a dianhydride monomer comprising at least one selected from the group consisting of dianhydride in a solvent;
Diamine monomers including 3,5-diaminobenzoic acid, paraphenylenediamine and 4,4'-oxydianiline and pyromellitic dianhydride, 3,3',4,4'-biphenyltetracarboxylicdian To obtain a second polyamic acid prepared by polymerizing a dianhydride monomer comprising at least one selected from the group consisting of hydride and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride in a solvent step;
co-extruding by providing a second discharging unit discharging the second polyamic acid so as to contact the first polyamic acid on at least one side of the first discharging unit discharging the first polyamic acid;
Method for producing a multilayer polyimide film comprising; imidizing the co-extruded polyamic acid. 10. The method according to claim 8 or 9,
The multilayer polyimide film has an adhesive strength of 1,000 gf / cm or more,
_{The glass transition temperature (T g} ) of the core part prepared from the first polyamic acid is 360 ° C. or higher, and the glass transition temperature (T _g ) of the skin part prepared from the second polyamic acid is 300 ° C. or higher Preparation of a multilayer polyimide film Way. 10. The method according to claim 8 or 9,
The multilayer polyimide film has a CTE of 7.5 ppm or more and 11 ppm or less, a MOR difference of 0.005 or less, an elastic modulus of 6.8 GPa or more and 7.5 GPa or less, and a strength of 360 MPa or more and 440 MPa or less. 9. The method of claim 8,
The first discharging part is located on a surface opposite to the surface in contact with the second discharging part, and the multilayer polyimide film further comprising a third discharging part discharging the second polyimide so as to be in contact with the other surface of the first polyimide. manufacturing method. 10. The method according to claim 8 or 9,
Each of the first polyamic acid and the second polyamic acid further comprises any one selected from the group consisting of an imidization catalyst, a dehydrating agent, a curing agent, a filler, and an additive in which one or more thereof is mixed. 10. The method of claim 9,
The co-extrusion step and the imidization step of the co-extruded polyamic acid is a method for producing a multilayer polyimide film that proceeds at the same time. A flexible metal clad laminate comprising the multilayer polyimide film of any one of claims 1 to 7 and an electrically conductive metal foil. An electronic component comprising the flexible metal clad laminate of claim 15 . 10. The method of claim 9,
The first discharge unit is located on the opposite side of the surface in contact with the second discharge unit, the multilayer polyimide film further comprising a third discharge unit discharging the second polyamic acid so as to be in contact with the other surface of the first polyamic acid manufacturing method.