KR102682573B1 - Multilayer polyimide film and manufacturing method of the same - Google Patents

Abstract

The present invention provides a multilayer polyimide film comprising a first skin layer and a second skin layer formed on one outer surface of a core layer and a surface opposite to the outer surface, respectively, and having an adhesive force with copper foil of 0.8 kgf/cm or more, and a method for manufacturing the same. provides.

Description

Multilayer polyimide film and manufacturing method thereof {MULTILAYER POLYIMIDE FILM AND MANUFACTURING METHOD OF THE SAME}

The present invention relates to a multilayer polyimide film that has excellent dimensional stability and excellent adhesive strength. More specifically, it relates to a multilayer polyimide film that has both high thermal dimensional stability and dimensional stability against moisture and excellent adhesive strength, and a method for manufacturing the same. .

Polyimide (PI) is a polymer material that has the highest level of heat resistance, chemical resistance, electrical insulation, chemical resistance, and weather resistance among organic materials, based on an imide ring with a rigid aromatic main chain and excellent chemical stability. am.

Polyimide film is attracting attention as a material for various electronic devices that require the above-mentioned properties.

Examples of micro-electronic components to which polyimide film is applied include thin, flexible circuit boards with high circuit integration to cope with the weight reduction and miniaturization of electronic products. Polyimide film is especially widely used as an insulating film for thin circuit boards. there is.

The thin circuit board generally has a structure in which a circuit including metal foil is formed on an insulating film. In a broad sense, such a thin circuit board is referred to as a flexible metal foil clad laminate and is made of a thin copper plate with metal foil. When used, it is sometimes referred to as Flexible Copper Clad Laminate (FCCL) in a narrower sense.

Methods for manufacturing flexible metal foil laminates include, for example, (i) casting or applying polyamic acid, a precursor of polyimide, onto metal foil and then imidizing it, (ii) sputtering. (iii) a metalizing method in which a metal layer is directly installed on a polyimide film; and (iii) a laminating method in which a polyimide film and a metal foil are bonded through heat and pressure through thermoplastic polyimide.

In particular, the metallization method produces a flexible metal foil laminate by, for example, sputtering a metal such as copper on a polyimide film with a thickness of 20 to 38 ㎛ and sequentially depositing a tie layer and a seed layer. This method has the advantage of forming ultrafine circuits with a circuit pattern pitch of 35 ㎛ or less, and is widely used to manufacture flexible metal foil laminates for COF (chip on film).

The polyimide film used in flexible metal foil laminates using the metallizing method must have high dimensional stability. Normally, dimensional stability is measured by thermal dimensional stability expressed by the thermal expansion coefficient, but dimensional stability against moisture, expressed by the hygroscopic expansion coefficient, is gradually becoming more important as well as thermal dimensional stability.

In other words, the demand for polyimide films that have excellent both thermal dimensional stability and dimensional stability against moisture is increasing, but when designing a polyimide film with a structure of high thermal dimensional stability with a low actual thermal expansion coefficient, dimensional stability against moisture The problem of this decline is emerging.

In addition, polyimide films with high dimensional limitations usually have the problem of reduced adhesion to sputtered metal plating.

Therefore, there is an urgent need for a polyimide film that not only has high thermal dimensional stability and high dimensional stability against moisture, but also has excellent adhesive strength.

The matters described in the above background technology are intended to aid understanding of the background of the invention, and may include matters that are not prior art already known to those skilled in the art in the field to which this technology belongs.

Republic of Korea Patent Publication No. 10-2012-0133807

Accordingly, the purpose of the present invention is to provide a polyimide multilayer film that simultaneously has high thermal dimensional stability and high dimensional stability against moisture and excellent adhesive strength.

However, the problem to be solved by the present invention is not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

One aspect of the present invention for achieving the above object includes a first skin layer and a second skin layer respectively formed on one outer surface of the core layer and on the opposite surface of the outer surface,

Adhesion with copper foil is 0.8 kgf/cm or more,

A multilayer polyimide film is provided.

Another aspect of the present invention includes the multilayer polyimide film and an electrically conductive metal foil,

Provided is a flexible metal foil laminate.

Another aspect of the present invention includes the flexible metal foil laminate,

Provides electronic components.

The present invention provides a polyimide film in which the composition ratio and reaction ratio of the dianhydride and diamine components are adjusted, thereby providing a polyimide film that is excellent in both thermal dimensional stability and dimensional stability against moisture as well as adhesive strength.

This polyimide film can be applied to various fields that require a polyimide film with excellent dimensional stability and adhesive strength, for example, to flexible metal foil laminates manufactured by metallizing methods or electronic components containing such flexible metal foil laminates.

Terms or words used in this specification and claims should not be construed as limited to their common or dictionary meanings, and the inventor may appropriately define the concept of terms in order to explain his or her invention in the best way. It must be interpreted with meaning and concept consistent with the technical idea of the present invention based on the principle that it is.

Therefore, the configuration of the embodiments described in this specification is only one of the most preferred embodiments of the present invention and does not represent the entire technical idea of the present invention, so various equivalents and modifications that can replace them at the time of filing the present application It should be understood that examples may exist.

In this specification, singular expressions include plural expressions, unless the context clearly dictates otherwise. In this specification, terms such as “comprise,” “comprise,” or “have” are intended to designate the presence of implemented features, numbers, steps, components, or a combination thereof, and are intended to indicate the presence of one or more other features or It should be understood that this does not exclude in advance the possibility of the presence or addition of numbers, steps, components, or combinations thereof.

As used herein, “dianhydride acid” is intended to include precursors or derivatives thereof, which may not technically be dianhydride acids, but which will nonetheless react with diamines to form polyamic acids, which in turn will form polyamic acids. It can be converted to mead.

As used herein, “diamine” is intended to include precursors or derivatives thereof, which may not technically be diamines, but which will nonetheless react with dianhydride to form polyamic acids, which in turn will form polyamic acids. Can be converted to mead

When amounts, concentrations, or other values or parameters are given herein as ranges, preferred ranges, or enumerations of upper preferred values and lower preferred values, any pair of upper range limits or It is to be understood that the preferred values and any lower range limits or all ranges formed from the preferred values are specifically disclosed.

When a range of numerical values is stated herein, unless otherwise stated, the range is intended to include the endpoints and all integers and fractions within the range. The scope of the invention is not intended to be limited to the specific values recited when defining the scope.

The multilayer polyimide film according to one embodiment of the present invention includes a first skin layer and a second skin layer formed on one outer surface of the core layer and a surface opposite to the outer surface, respectively, and has an adhesive force with copper foil of 0.8 kgf/ It can be more than cm.

That is, the multilayer polyimide film may be a multilayer polyimide film with a three-layer structure in which a first skin layer and a second skin layer are formed around a core layer and on one outer surface of the core layer and an opposite surface of the outer surface, respectively. .

Meanwhile, the components and composition ratios of the first skin layer and the second skin layer may be the same or different.

Additionally, the thickness of the first skin layer and the second skin layer may be the same or different.

The copper foil may be formed on one or more sides of the multilayer polyimide film of the present application through a sputter-electroplating method.

In one embodiment, the thermal expansion coefficient of the multilayer polyimide film in the traverse direction (TD) is 2.0 ppm/℃ or more and 6.0 ppm/℃ or less, and the hygroscopic expansion coefficient in the traverse direction (TD) is It may be 3.0 ppm/RH% or more, and may be 6.0 ppm/RH% or less.

For example, the thermal expansion coefficient in the traverse direction (TD) may be 2.5 ppm/°C or more and 6.0 ppm/°C or less.

In addition, the moisture absorption expansion coefficient in the traverse direction (TD) may be, for example, 4.5 ppm/RH% or more and 6.0 ppm/RH% or less.

In one embodiment, the core layer of the multilayer polyimide film includes a dianhydride component including biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA), and paraphenylene diamine. It can be obtained by imidizing a polyamic acid solution containing a diamine component including (PPD) and m-tolidine.

Meanwhile, at least one of the first skin layer and the second skin layer is biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, oxydiphthalic anhydride (ODPA), and benzophenone tetracarboxylic dianhydride. A dianhydride component containing two or more selected from the group consisting of dianhydride (BTDA), and any one selected from the group consisting of oxydianiline (ODA) and 1,3-bisaminophenoxybenzene (TPE-R) It can be obtained by subjecting a polyamic acid solution containing the above diamine component to an imidization reaction.

For example, at least one of the first skin layer and the second skin layer uses biphenyltetracarboxylic dianhydride and pyromellitic dianhydride as dianhydride components, or biphenyltetracarboxylic dianhydride. Use licdianhydride, pyromellitic dianhydride, and oxydiphthalic dianhydride together, or use biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, and benzophenone tetracarboxylic dianhydride together. You can use it.

Additionally, for example, at least one of the first skin layer and the second skin layer may use only oxydianiline as a diamine component, or may use oxydianiline and 1,3-bisaminophenoxybenzene together.

In one embodiment, the core layer has a content of the biphenyltetracarboxylic dianhydride of 40 mol% or more and 60 mol% or less, based on 100 mol% of the total content of the dianhydride component, and the pyromelli The content of ticdianhydride is 40 mol% or more and 60 mol% or less, and the content of paraphenylene diamine is 50 mol% or more and 70 mol% or less, based on 100 mol% of the total content of the diamine component, and The content of m-tolidine may be 30 mol% or more and 50 mol% or less.

In one embodiment, at least one of the first skin layer and the second skin layer has a content of the biphenyltetracarboxylic dianhydride of 15% based on 100 mol% of the total content of the dianhydride component. mol% or more and 85 mol% or less, the content of the pyromellitic dianhydride is 15 mol% or more and 60 mol% or less, the content of the oxydiphthalic anhydride is 35 mol% or less, and the benzophenonetetracarboxyl The content of ricdianhydride is 35 mol% or less, the content of oxydianiline is 20 mol% or more and 100 mol% or less based on the total content of 100 mol% of the diamine component, and 1,3-bisamino The content of phenoxybenzene may be 80 mol% or less.

Paraphenylene diamine of the present invention is a rigid monomer, and as the content of paraphenylene diamine increases, the polyimide synthesized has a more linear structure, contributing to the improvement of the mechanical properties of the polyimide.

also. m-tolidine has a particularly hydrophobic methyl group, contributing to the low moisture absorption properties associated with the dimensional stability of polyimide films against moisture.

The polyimide chain derived from biphenyltetracarboxylic dianhydride of the present invention has a structure named charge transfer complex (CTC), that is, an electron donor and an electron acceptor. They have regular straight structures located close to each other, and intermolecular interactions are strengthened.

Since this structure has the effect of preventing hydrogen bonding with moisture, it can maximize the effect of lowering the hygroscopicity of the polyimide film, which affects dimensional stability against moisture by lowering the moisture absorption rate.

In addition, pyromellitic dianhydride is a dianhydride component with a relatively rigid structure and is preferable because it can provide appropriate elasticity to the polyimide film.

In order for a polyimide film to have excellent dimensional stability, the content ratio of dianhydride is important. For example, as the content ratio of biphenyltetracarboxylic dianhydride decreases, it becomes difficult to expect a low moisture absorption rate due to the CTC structure, and dimensional stability against moisture also decreases.

In addition, biphenyltetracarboxylic dianhydride contains two benzene rings corresponding to the aromatic moiety, while pyromellitic dianhydride contains one benzene ring corresponding to the aromatic moiety.

The increase in the content of pyromellitic dianhydride in the dianhydride component can be understood as an increase in the imide group within the molecule based on the same molecular weight, which means that the imide group derived from the pyromellitic dianhydride is added to the polyimide polymer chain. It can be understood that the ratio of the group increases relative to the imide group derived from biphenyltetracarboxylic dianhydride.

In other words, the increase in pyromellitic dianhydride content can be seen as a relative increase in imide groups in the entire polyimide film, which makes it difficult to expect high dimensional stability against moisture due to low moisture absorption.

Conversely, when the content ratio of pyromellitic dianhydride is reduced, the component with a relatively rigid structure is reduced, and the elasticity of the polyimide film may be lowered below a desired level.

For this reason, when the content of the biphenyltetracarboxylic dianhydride exceeds the above range or the content of pyromellitic dianhydride is below the above range, the dimensional stability of the polyimide film may be reduced.

Conversely, even if the content of the biphenyltetracarboxylic dianhydride is below the above range or the content of the pyromellitic dianhydride is above the above range, the dimensional stability of the polyimide film may be adversely affected. .

In the present invention, the production of polyamic acid is, for example,

(1) A method of polymerizing the entire amount of the diamine component in a solvent, and then adding the dianhydride component in substantially equimolar amounts to the diamine component;

(2) A method of polymerizing the entire amount of the dianhydride component in a solvent, and then adding the diamine component in substantially equimolar amounts to the dianhydride component;

(3) After adding some of the diamine components into the solvent, mixing some of the dianhydride components in a ratio of about 95 to 105 mol% with respect to the reaction components, adding the remaining diamine components, and then adding the remaining dianhydride components continuously. A method of polymerizing by adding components such that the diamine component and the dianhydride component are substantially equimolar;

(4) After adding the dianhydride component into the solvent, mixing some components of the diamine compound in a ratio of 95 to 105 mol% with respect to the reaction components, adding another dianhydride component, and then adding the remaining diamine component, A method of polymerizing the diamine component and the dianhydride component in substantially equimolar amounts;

(5) reacting some diamine components and some dianhydride components in a solvent so that either one is in excess to form a first composition, and reacting some diamine components with some dianhydride components in another solvent so that either one is in excess. After forming the second composition, the first and second compositions are mixed and polymerization is completed. In this case, if the diamine component is excessive when forming the first composition, the dianhydride component is added in excess in the second composition. When the dianhydride component is excessive in the first composition, the diamine component is excessive in the second composition, and the first and second compositions are mixed so that the total diamine component and dianhydride component used in these reactions are substantially A method of polymerizing them in an equimolar manner may be included.

In the present invention, the polymerization method of the polyamic acid as described above can be defined as a random polymerization method, and the polyimide film manufactured from the polyamic acid of the present invention manufactured through the above process has dimensional stability and chemical resistance. Height can be preferably applied in terms of maximizing the effect of the present invention.

However, since the above polymerization method produces a relatively short length of the repeating unit in the polymer chain described above, there may be limitations in demonstrating each of the excellent properties of the polyimide chain derived from the dianhydride component. Therefore, the polymerization method of polyamic acid that can be particularly preferably used in the present invention may be a block polymerization method.

On the other hand, the solvent for synthesizing polyamic acid is not particularly limited, and any solvent can be used as long as it dissolves polyamic acid, but it is preferable that it is an amide-based solvent.

Specifically, the organic solvent may be an organic polar solvent, and in particular, may be an aprotic polar solvent, for example, N,N-dimethylformamide (DMF), N,N - It may be one or more selected from the group consisting of dimethylacetamide, N-methyl-pyrrolidone (NMP), gamma butyrolactone (GBL), and Diglyme, but is not limited thereto, and may be used alone as needed. Or, two or more types can be used in combination.

In one example, N,N-dimethylformamide and N,N-dimethylacetamide may be particularly preferably used as the organic solvent.

Additionally, in the polyamic acid manufacturing process, fillers may be added to improve various properties of the film such as sliding properties, thermal conductivity, corona resistance, and loop hardness. The added filler is not particularly limited, but preferred examples include silica, titanium oxide, alumina, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, and mica.

The particle size of the filler is not particularly limited and may be determined depending on the film properties to be modified and the type of filler to be added. Generally, the average particle diameter is 0.05 to 100 μm, preferably 0.1 to 75 μm, more preferably 0.1 to 50 μm, and particularly preferably 0.1 to 25 μm.

If the particle size is below this range, it becomes difficult to achieve a reforming effect, and if the particle size is above this range, the surface properties may be greatly damaged or the mechanical properties may be greatly reduced.

Additionally, the amount of filler added is not particularly limited and may be determined based on the film properties to be modified, the particle size of the filler, etc. Generally, the amount of filler added is 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.

If the amount of filler added is less than this range, it is difficult to achieve a reforming effect due to the filler, and if it is more than this range, the mechanical properties of the film may be significantly damaged. The method of adding the filler is not particularly limited, and any known method may be used.

In the production method of the present invention, the polyimide film can be produced by thermal imidization and chemical imidization.

In addition, it may be manufactured by a complex imidization method in which thermal imidization and chemical imidization are combined.

The thermal imidization method is a method of inducing an imidization reaction using a heat source such as hot air or an infrared dryer, excluding chemical catalysts.

The thermal imidization method can imidize the amic acid group present in the gel film by heat treating the gel film at a variable temperature in the range of 100 to 600 ℃, specifically 200 to 500 ℃, more specifically, The amic acid group present in the gel film can be imidized by heat treatment at 300 to 500°C.

However, even in the process of forming a gel film, some of the amic acid (about 0.1 mol% to 10 mol%) may be imidized, and for this purpose, the polyamic acid composition is dried at a variable temperature in the range of 50 ℃ to 200 ℃. It can also be included in the scope of the thermal imidization method.

In the case of chemical imidization, a polyimide film can be produced using a dehydrating agent and an imidizing agent according to methods known in the art.

As an example of a complex imidization method, a dehydrating agent and an imidizing agent are added to a polyamic acid solution, then heated at 80 to 200°C, preferably 100 to 180°C, partially cured and dried, and then heated to 5 to 400°C at 200 to 400°C. A polyimide film can be produced by heating for a few seconds.

Meanwhile, the multilayer polyimide film of the present invention described so far can be manufactured using one or more of coextrusion or coating methods.

The co-extrusion method is a method of filling a storage tank with a polyamic acid solution or a polyimide resin prepared by imidizing it, extruding multiple layers on a casting belt using a co-extrusion die, and then curing to produce a polyimide film with a multi-layer structure. As a result, productivity is high and different types of polyimide resins are mixed between the interfaces to ensure high interfacial adhesion reliability.

For example, the method for manufacturing a multilayer polyimide film of the present invention includes a first charging process in which a first solution, which is a first polyamic acid solution or a first polyimide resin prepared by imidizing a first polyamic acid solution, is charged into a first storage tank. Step, a second charging step of filling the second reservoir with a second polyamic acid solution or a second solution of a second polyimide resin prepared by imidizing the second polyamic acid solution, a first flow path connected to the first reservoir, 2 A co-extrusion step of co-extruding the first solution and the second solution through a co-extrusion die in which a second flow path and a third flow path respectively connected to the reservoir are formed inside, and curing the co-extruded first solution and the second solution. It proceeds including a curing step.

The first polyamic acid solution is for forming a core layer, and contains a dianhydride component including biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA), and paraphenylene diamine (PPD). ) and m-tolidine (m-tolidine) is preferably produced by polymerizing the diamine component.

The second polyamic acid solution is for forming the first skin layer and the second skin layer, and contains biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, oxydiphthalic anhydride (ODPA), and benzophenone. A dianhydride component containing two or more selected from the group consisting of tetracarboxylic dianhydride (BTDA), and a group consisting of oxydianiline (ODA) and 1,3-bisaminophenoxybenzene (TPE-R). It is preferably produced by polymerizing a diamine component containing one or more selected substances.

On the other hand, when using the first polyamic acid solution as the first solution and the second polyamic acid solution as the second solution, the first solution and the second solution co-extruded before the curing step are imidized. It is preferable that the process further includes an imidization step.

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

There is no particular limitation on the metal foil to be used, but when using the flexible metal foil laminate of the present invention for electronic or electrical equipment, for example, copper or copper alloy, stainless steel or its alloy, nickel or nickel alloy (42 alloy) Also included), may be a metal foil containing aluminum or aluminum alloy.

In general flexible metal foil laminates, copper foils such as rolled copper foil and electrolytic copper foil are widely used, and can also be preferably used in the present invention. Additionally, a rust-prevention layer, a heat-resistant layer, or an adhesive layer may be applied to the surface of these metal foils.

In the present invention, the thickness of the metal foil is not particularly limited, and may be sufficient to provide sufficient function depending on the intended use.

The flexible metal foil laminate according to the present invention may have a structure in which metal foil is laminated on at least one side of the multilayer polyimide film.

Hereinafter, the operation and effects of the invention will be described in more detail through specific manufacturing examples and examples of the invention. However, these manufacturing examples and examples are merely presented as examples of the invention, and the scope of the invention is not limited thereby.

Manufacturing example: Preparation of multilayer polyimide film

Biphenyl tetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), oxydiphthalic dianhydride (ODPA), benzophenone tetracarboxylic dianhydride (BTDA), paraphenylene diamine ( Select dianhydride and diamine components among PPD), m-tolidine (MTD), 1,3-bisaminophenoxybenzene (TPE-R), and oxydianiline (ODA) and polymerize them to form a core layer. A first polyamic acid solution to be used in production was prepared.

Biphenyl tetracarboxylic dianhydride, pyromellitic dianhydride, oxydiphthalic dianhydride, benzophenone tetracarboxylic dianhydride, paraphenylene diamine, m-tolidine, 1,3-bisaminophenok Dianhydride and diamine components were selected from cybenzene and oxydianiline and subjected to polymerization reaction to prepare a second polyamic acid solution to be used in manufacturing the first and second skin layers.

A multi-layer polyimide film in which a first skin layer and a second skin layer are formed around the core layer by co-extruding the previously prepared first polyamic acid solution and the second polyamic acid solution through a co-extrusion method, imidizing the solution, and then curing it. was manufactured.

However, here, the core layer was manufactured by co-extruding the first polyamic acid solution, and the first skin layer and the second skin layer were manufactured by co-extruding the second polyamic acid solution.

When producing the polyamic acid, the solvent is generally an amide-based solvent, such as an aprotic polar solvent (Aprotic solvent), such as N,N'-dimethylformamide, N,N'-dimethylacetamide, and N-methyl-pyrroli. You can use money, or a combination of these.

The dianhydride and diamine components can be added in the form of powder, lump, and solution. It is preferable to add them in the form of powder at the beginning of the reaction to proceed with the reaction, and then add them in the form of a solution to control the polymerization viscosity. .

The obtained polyamic acid solution can be mixed with an imidization catalyst and a dehydrating agent and applied to a support.

Examples of catalysts used include tertiary amines (eg, isoquinoline, β-picoline, pyridine, etc.), and examples of dehydrating agents include, but are not limited to, anhydrous acid.

Examples and Comparative Examples

As shown in Table 1 below (components and composition ratio of the core layer) and Table 2 below (components and composition ratio of the skin layer), the dianhydride component of the core layer and skin layer in Examples 1 to 6 and Comparative Examples 1 to 9 And the content of the diamine component was adjusted to prepare a multilayer polyimide film according to the production example.

The composition and component ratio of the first skin layer and the second skin layer of Examples 1 to 6 and Comparative Example 9 were the same, and the thickness was also manufactured to be the same.

However, Comparative Examples 1 to 8 corresponded to single-layer polyimide films and only the core layer was manufactured.

Core layer Dianhydride (mol%) Diamine (mol%) PMDA BPDA BTDA ODPA O.D.A. TPE-R MTD PPD Example 1 50 50 - - - - 40 60 Example 2 50 50 - - - - 40 60 Example 3 50 50 - - - - 40 60 Example 4 50 50 - - - - 40 60 Example 5 50 50 - - - - 40 60 Example 6 50 50 - - - - 40 60 Comparative Example 1 50 50 - - - - 40 60 Comparative example 2 50 50 - - 100 - - - Comparative Example 3 25 50 - 25 55 45 - - Comparative example 4 25 50 25 - 55 45 - - Comparative Example 5 25 75 - - 55 45 - - Comparative Example 6 50 25 25 - 55 45 - - Comparative example 7 50 25 - 25 30 70 - - Comparative example 8 50 50 - - 13 - - 87 Comparative Example 9 50 50 - - 13 - - 87

First and second skin layers Dianhydride (mol%) Diamine (mol%) PMDA BPDA BTDA ODPA O.D.A. TPE-R Example 1 50 50 - - 100 - Example 2 25 50 - 25 55 45 Example 3 25 50 25 - 55 45 Example 4 25 75 - - 55 45 Example 5 50 25 25 - 55 45 Example 6 50 25 - 25 30 70 Comparative Example 1 - - - - - - Comparative example 2 - - - - - - Comparative Example 3 - - - - - - Comparative example 4 - - - - - - Comparative Example 5 - - - - - - Comparative Example 6 - - - - - - Comparative example 7 - - - - - - Comparative example 8 - - - - - - Comparative Example 9 50 50 - - 100 -

The coefficient of thermal expansion (CTE), coefficient of hydroscopic expansion (CHE), and adhesion in the width direction of the manufactured polyimide film were measured and shown in Table 3 below.

CTE
(ppm/℃) CHE
(ppm/%) adhesion
(kgf/cm) Example 1 4.4 5.4 0.83 Example 2 2.9 5.2 0.97 Example 3 3.2 4.9 0.85 Example 4 4.4 5.5 1.01 Example 5 5.8 5.9 0.86 Example 6 4.7 5.3 0.94 Comparative Example 1 2.0 4.4 0.58 Comparative Example 2 41 18 0.85 Comparative Example 3 19.1 11.8 0.98 Comparative Example 4 24.2 13.3 0.86 Comparative Example 5 25.7 14.1 1.08 Comparative Example 6 55.2 19.6 0.87 Comparative Example 7 43.1 17.8 0.96 Comparative Example 8 6.1 7.3 0.67 Comparative Example 9 8.4 9.2 0.82

(1) Measurement of thermal expansion coefficient

The coefficient of thermal expansion (CTE) was measured using TA's thermomechanical analyzer Q400 model. The manufactured multilayer polyimide film was cut to 4 mm in width and 20 mm in length, and a tension of 0.05 N was applied under a nitrogen atmosphere, and 10 The temperature was raised from 30°C to 400°C at a rate of ℃/min, and then cooled again at a rate of 10°C/min, and the slope from 50°C to 200°C was measured.

(2) Measurement of moisture absorption expansion coefficient

The coefficient of hygroscopic expansion (CHE) is determined by applying the minimum weight to prevent the manufactured multilayer polyimide film from loosening (approximately 1 g for a sample of 25 mm The dimensions were measured by absorbing moisture until the humidity was adjusted to 90%RH, and then the moisture absorption was saturated in the same manner, and then the dimensions were measured. The rate of dimensional change was measured from both results.

(3) Adhesion measurement

A copper thin film layer with a thickness of about 80-300 nm is deposited on the manufactured multilayer polyimide film as a copper seed layer for electroplating electrodes through sputtering, and a copper conductive layer with a thickness of about 8-9 μm is formed through electroplating. was formed to produce a flexible metal foil laminate for COF.

The flexible metal foil laminate was etched into a 2 mm wide rod using a wet layering method, and then a 90° peel test was performed using a Universal Testing Machine to measure adhesion by pulling at a speed of 20 mm/min.

As a result of the measurement, the multilayer polyimide films of Examples 1 to 6 had a thermal expansion coefficient in the width direction of 2.0 ppm/℃ or more and 6.0 ppm/℃ or less, and a moisture absorption expansion coefficient in the width direction of 3.0 ppm/RH% or more and 6.0. It showed characteristics of ppm/RH% or less and adhesion to copper foil of 0.8 kgf/cm or more.

In contrast, the polyimide films of Comparative Examples 1 to 8 and the multilayer polyimide film of Comparative Example 9, which had different components and/or composition ratios from those of the Examples and consisted of only one layer, had thermal expansion coefficient, hygroscopic expansion coefficient, and copper foil. The multilayer polyimide film of the present application did not satisfy the characteristics required for more than one characteristic of adhesion.

Accordingly, the multilayer polyimide films of Examples 1 to 6 manufactured within the appropriate range of the present application were excellent in all thermal dimensional stability, dimensional stability against moisture, and adhesion to copper foil. However, if the multilayer polyimide films were outside the appropriate range of the present application, the multilayer polyimide films of the present application were excellent. It was confirmed that it was difficult to satisfy all of the thermal dimensional stability of the multilayer polyimide film, dimensional stability against moisture, and adhesion to copper foil.

In other words, it was confirmed that a multilayer polyimide film that has excellent dimensional stability and adhesion to copper foil and satisfies all of the various conditions applicable to application fields is a multilayer polyimide film manufactured within the appropriate scope of the present application.

The examples of the multilayer polyimide film and the manufacturing method of the multilayer polyimide film of the present invention are only preferred examples that enable those skilled in the art to easily practice the present invention, and the above-described implementation Since it is not limited to examples, the scope of rights of the present invention is not limited by this. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the attached patent claims. In addition, it will be clear to those skilled in the art that various substitutions, modifications and changes can be made without departing from the technical spirit of the present invention, and it is obvious that parts that can be easily changed by those skilled in the art are also included in the scope of rights of the present invention. .

Claims (9)

It includes a first skin layer and a second skin layer formed on one outer surface of the core layer and an opposite surface of the outer surface, respectively,
The adhesion with copper foil is more than 0.8 kgf/cm,
The thermal expansion coefficient in the traverse direction (TD) is 2.0 ppm/℃ or more and 6.0 ppm/℃ or less,
The moisture absorption expansion coefficient in the traverse direction (TD) is 3.0 ppm/RH% or more and 6.0 ppm/RH% or less,
Multilayer polyimide film. delete According to paragraph 1,
The core layer includes a dianhydride component including biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA),
Obtained by imidizing a polyamic acid solution containing a diamine component including paraphenylene diamine (PPD) and m-tolidine,
Multilayer polyimide film. According to paragraph 1,
At least one selected from the group consisting of the first skin layer and the second skin layer is biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, oxydiphthalic anhydride (ODPA), and benzophenone tetrahydride. A dianhydride component containing two or more selected from the group consisting of carboxylic dianhydride (BTDA),
Obtained by imidizing a polyamic acid solution containing a diamine component containing at least one selected from the group consisting of oxydianiline (ODA) and 1,3-bisaminophenoxybenzene (TPE-R),
Multilayer polyimide film. According to paragraph 3,
Based on the total content of the dianhydride component of 100 mol%, the content of the biphenyltetracarboxylic dianhydride is 40 mol% to 60 mol%, and the content of the pyromellitic dianhydride is 40 mol%. More than 60 mol% or less,
Based on the total content of the diamine component of 100 mol%, the paraphenylene diamine content is 50 mol% or more and 70 mol% or less, and the m-tolidine content is 30 mol% or more and 50 mol% or less,
Multilayer polyimide film. According to paragraph 4,
Based on the total content of the dianhydride component of 100 mol%, the content of the biphenyltetracarboxylic dianhydride is 15 mol% to 85 mol%, and the content of the pyromellitic dianhydride is 15 mol%. It is 60 mol% or less, the content of the oxydiphthalic anhydride is 35 mol% or less, and the content of the benzophenone tetracarboxylic dianhydride is 35 mol% or less,
Based on the total content of the diamine component of 100 mol%, the oxydianiline content is 20 mol% to 100 mol%, and the 1,3-bisaminophenoxybenzene content is 80 mol% or less,
Multilayer polyimide film. According to any one of claims 1 and 3 to 6,
The multilayer polyimide film is manufactured by one or more methods selected from the group consisting of coextrusion and coating.
Multilayer polyimide film. Comprising a multilayer polyimide film according to any one of claims 1 and 3 to 6 and an electrically conductive metal foil,
Flexible metal foil laminate. Comprising a flexible metal foil laminate according to claim 8,
Electronic parts.