WO2023096440A1 - Multilayer polyimide film and method for manufacturing same - Google Patents

Abstract

The present invention provides a multilayer polyimide film and a manufacturing method therefor, wherein the multilayer polyimide film comprises a first skin layer and a second skin layer that are disposed on one outer surface and an opposite surface thereto in a core layer, respectively, and has an adhesive force to copper foil of 0.8 kgf/cm or greater.

Description

Polyimide film with multi-layer structure and manufacturing method thereof

The present invention relates to a multilayer polyimide film having excellent dimensional stability and excellent adhesive strength, and more particularly, to a multilayer polyimide film having both high thermal dimensional stability and high dimensional stability against moisture and excellent adhesive strength, and a manufacturing method thereof. .

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

Polyimide films are in the limelight as materials for various electronic devices requiring the above-described characteristics.

Examples of microelectronic parts to which polyimide films are applied include flexible thin circuit boards with high circuit integration to respond to the lightening and miniaturization of electronic products. Polyimide films are particularly widely used as insulating films 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, and this thin circuit board is referred to as a flexible metal foil clad laminate in a broad sense, and a thin copper plate is used as a metal foil. When used, it is also referred to as Flexible Copper Clad Laminate (FCCL) in a narrower sense.

As a method for producing a flexible metal foil 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) sputtering and (iii) a lamination method in which a polyimide film and a metal foil are bonded with heat and pressure through a thermoplastic polyimide.

In particular, the metallization method produces, for example, a flexible metal clad laminate by sputtering a metal such as copper on a polyimide film having a thickness of 20 to 38 μm, and sequentially depositing a tie layer and a seed layer. It is a method of doing, and has an advantage in forming an ultra-fine circuit having a circuit pattern pitch of 35 μm or less, and is widely used in manufacturing a flexible metal foil laminate for COF (chip on film).

A polyimide film used in a metallized flexible metal foil laminate should have high dimensional stability. Usually, dimensional stability is measured by thermal dimensional stability represented by a thermal expansion coefficient, but dimensional stability to moisture represented by a hygroscopic expansion coefficient is gradually increasing in importance as well as thermal dimensional stability.

That is, although there is an increasing demand for polyimide films having excellent thermal dimensional stability and dimensional stability against moisture, when designing a polyimide film having a structure with high thermal dimensional stability with a low coefficient of actual thermal expansion, dimensional stability against moisture The problem of this lowering is emerging.

In addition, a polyimide film having high dimension limitation has a problem in that adhesion to sputter metal plating is generally lowered.

Accordingly, there is an urgent need for a polyimide film having excellent adhesive strength as well as high thermal dimensional stability and high water dimensional stability.

Matters described in the background art above are intended to aid understanding of the background of the invention, and may include matters other than those of the prior art already known to those skilled in the art.

[Prior art literature]

[Patent Literature]

(Patent Document 1) Republic of Korea Patent Publication No. 10-2012-0133807

Accordingly, an object of the present invention is to provide a polyimide multilayer film having high thermal dimensional stability, high dimensional stability against moisture, and excellent adhesive strength at the same time.

However, the problem to be solved by the present invention is not limited to the above-mentioned problem, 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 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 the electrically conductive metal foil,

A flexible metal foil laminate is provided.

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

We provide electronic components.

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

Such a polyimide film can be applied to various fields requiring a polyimide film having excellent dimensional stability and adhesive strength, for example, a flexible metal foil laminate manufactured by a metallization method or an electronic component including such a flexible metal foil laminate.

The terms or words used in this specification and claims should not be construed as being limited to ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to explain their invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that there is.

Therefore, since 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 all of the technical spirit of the present invention, various equivalents and modifications that can replace them at the time of 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 "having" are intended to indicate that there is an embodied feature, number, step, component, or combination thereof, but one or more other features or It should be understood that the presence or addition of numbers, steps, components, or combinations thereof is not precluded.

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

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

When amounts, concentrations, or other values or parameters herein are given as ranges, preferred ranges, or recitations of upper preferred and lower preferred values, any pair of any upper range limits, whether or not the ranges are separately disclosed, or It should be understood as specifically disclosing the preferred values and any lower range limits or all ranges formed from preferred values.

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

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

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

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

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

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

In one embodiment, the multilayer polyimide film has a thermal expansion coefficient of 2.0 ppm/°C or more and 6.0 ppm/°C or less in a transverse direction (TD), and a hygroscopic expansion coefficient in a transverse direction (TD) 3.0 ppm/RH% or more, and may be 6.0 ppm/RH% or less.

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

In addition, the moisture absorption expansion coefficient in the transverse 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. (PPD) and m- tolidine (m-tolidine) can be obtained by imidization reaction of a polyamic acid solution containing a diamine component.

On the other hand, at least one of the first skin layer and the second skin layer is biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, oxydiphthalic anhydride (ODPA) and benzophenone tetracarboxylic Any one selected from the group consisting of dianhydride (BTDA), dianhydride (BTDA), dianhydride (2 or more), and oxydianiline (ODA) and 1,3-bisaminophenoxybenzene (TPE-R) It can be obtained by imidization reaction of the polyamic acid solution containing the diamine component containing the above.

For example, at least one of the first skin layer and the second skin layer uses biphenyltetracarboxylic dianhydride and pyromellitic dianhydride together as a dianhydride component, or biphenyltetracarboxylic dianhydride. ricdianhydride, pyromellitic dianhydride and oxydiphthalic dianhydride together, or biphenyltetracarboxylic dianhydride, pyromellitic dianhydride and benzophenonetetracarboxylic dianhydride together can be used

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

In one embodiment, the core layer has a biphenyltetracarboxylic dianhydride content 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 thicdianhydride is 40 mol% or more and 60 mol% or less, and the paraphenylene diamine content is 50 mol% or more and 70 mol% or less based on 100 mol% of the total content of the diamine component, 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 biphenyltetracarboxylic dianhydride content 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 benzophenonetetracarboxylic 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 100 mol% of the total content of the diamine component, and 1,3-bisamino The content of phenoxybenzene may be 80 mol% or less.

Para-phenylene diamine of the present invention is a rigid monomer, and as the content of para-phenylene diamine increases, the synthesized polyimide has a more linear structure and contributes to improving the mechanical properties of the polyimide.

also. Since m-tolidine has a methyl group that is particularly hydrophobic, it contributes to the low moisture absorption property related to the dimensional stability of the polyimide film against water.

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

Since this structure has an effect of preventing hydrogen bonding with moisture, it is possible to maximize the effect of lowering the hygroscopicity of the polyimide film, which affects the dimensional stability to moisture by affecting the lowering of the moisture absorption rate.

In addition, pyromellitic dianhydride is a dianhydride component having a relatively rigid structure, and is preferable in that it can impart appropriate elasticity to the polyimide film.

In order for the 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 deteriorates.

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

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

That is, the increase in the pyromellitic dianhydride content can be seen as a relative increase in the imide group with respect to the entire polyimide film, and as a result, it is difficult to expect high dimensional stability against moisture due to a low moisture absorption.

Conversely, when the content ratio of pyromellitic dianhydride is decreased, the component having a relatively rigid structure is reduced, and thus the elasticity of the polyimide film may be lowered to a desired level or less.

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

Conversely, even when the content of the biphenyltetracarboxylic dianhydride is less than the above range or the content of the pyromellitic dianhydride exceeds the above range, the dimensional stability of the polyimide film may be adversely affected. .

Production of polyamic acid in the present invention, for example,

(1) A method in which the entire amount of the diamine component is placed in a solvent, and thereafter a dianhydride component is added so as to be substantially equimolar to the diamine component, followed by polymerization;

(2) a method in which the entire amount of the dianhydride component is placed in a solvent, and then a diamine component is added so as to be substantially equimolar to the dianhydride component, followed by polymerization;

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

(4) After putting the dianhydride component in the solvent, some components of the diamine compound are mixed in a ratio of 95 to 105 mol% with respect to the reaction components, then another dianhydride component is added, and then the remaining diamine components are added, a method of polymerizing the diamine component and the dianhydride component so that they are substantially equimolar;

(5) Some diamine components and some dianhydride components are reacted in an excess amount in a solvent to form a first composition, and some diamine components and some dianhydride components are reacted in an excess amount in another solvent to form a first composition. A method of mixing the first and second compositions after forming the second composition and completing the polymerization, wherein, if the diamine component is excessive when forming the first composition, the dianhydride component is added in excess in the second composition And, 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 entire diamine component and the dianhydride component used in these reactions are substantially reduced. The method of polymerizing by making it equimolar, etc. are mentioned.

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 prepared from the polyamic acid of the present invention manufactured by the above process has dimensional stability and chemical resistance. The height may be preferably applied in terms of maximizing the effect of the present invention.

However, since the polymerization method produces a relatively short length of the repeating unit in the polymer chain described above, there may be limitations in exhibiting the excellent properties of each polyimide chain derived from the dianhydride component. Therefore, the polymerization method of the 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 the polyamic acid is not particularly limited, and any solvent can be used as long as it dissolves the polyamic acid, but an amide-based solvent is preferable.

Specifically, the organic solvent may be an organic polar solvent, and in detail, 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 it can use in combination of 2 or more types.

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

In addition, in the polyamic acid manufacturing process, a filler may be added for the purpose of improving various properties of the film, such as sliding properties, thermal conductivity, corona resistance, and loop hardness. The filler added is not particularly limited, but preferable examples 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. Generally, the average particle size is 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 diameter is less than this range, the modification effect becomes difficult to appear, and when it exceeds this range, surface properties may be greatly damaged or mechanical properties may be greatly reduced.

Further, the addition amount of the filler is not particularly limited either, and may be determined according to the properties of the film to be modified, the particle size of the filler, and the like. Generally, the added amount of the filler 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 the polyimide.

If the added amount of the filler is less than this range, the modification effect by the filler is difficult to appear, and if it exceeds 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 may be prepared by thermal imidation or chemical imidation.

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

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

In the thermal imidation method, the amic acid group present in the gel film may be imidized by heat-treating the gel film at a variable temperature in the range of 100 to 600 ° C, specifically 200 to 500 ° C, more specifically, Amic acid groups present in the gel film may be imidized by heat treatment at 300 to 500 °C.

However, some of the amic acid (about 0.1 mol% to 10 mol%) may be imidized even in the process of forming the gel film. This may also be included in the scope of the thermal imidization method.

In the case of chemical imidation, a polyimide film may be prepared using a dehydrating agent and an imidizing agent according to a method known in the art.

As an example of the composite imidation method, a dehydrating agent and an imidizing agent 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 5 to 400 ° C at 200 to 400 ° C. A polyimide film can be manufactured by heating for a second.

Meanwhile, the multilayer polyimide film of the present invention described so far may be manufactured using at least one method of co-extrusion or coating.

In the co-extrusion method, after filling a reservoir with a polyamic acid solution or a polyimide resin prepared by imidizing the same, a multi-layer extrusion method is performed on a casting belt using a co-extrusion die, and then cured to produce a polyimide film having a multi-layer structure. As a result, productivity is high, and different types of polyimide resins are mixed between interfaces to ensure high interfacial adhesion reliability.

For example, in the method for manufacturing a multilayer polyimide film of the present invention, a first filling of a first polyamic acid solution or a first solution that is a first polyimide resin prepared by imidizing the first polyamic acid solution is filled in a first reservoir. A second filling step of filling a second reservoir with a second polyamic acid solution or a second solution that is 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 having second and third flow passages connected therein, respectively, and curing the co-extruded first and second solutions. It proceeds including a curing step to

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

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

On the other hand, when the first polyamic acid solution is used as the first solution and the second polyamic acid solution is used as the second solution, the first solution and the second solution co-extruded before the curing step are imidized. It is preferable to proceed by further including an imidization step.

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

The metal foil used is not particularly limited, but in the case of using the flexible metal foil laminate of the present invention for electronic devices or electrical devices, for example, copper or copper alloy, stainless steel or its alloy, nickel or nickel alloy (42 alloy Also included), it 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 often used, and they can be preferably used in the present invention as well. Moreover, a rust prevention layer, a heat resistance 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 any thickness capable of exhibiting sufficient functions depending on its 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 surface of the multilayer polyimide film.

Hereinafter, the action and effect 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 only presented as examples of the invention, and the scope of the invention is not limited thereby.

Production example: production of multi-layer polyimide film

Biphenyltetracarboxylic dianhydride (BPDA), pyromellitic dianhydride (PMDA), oxydiphthalic anhydride (ODPA), benzophenonetetracarboxylic dianhydride (BTDA), paraphenylene diamine ( PPD), m-tolidine (MTD), 1,3-bisaminophenoxybenzene (TPE-R), and oxydianiline (ODA), dianhydride acid and diamine components are selected and polymerized to form a core layer A first polyamic acid solution to be used for the preparation was prepared.

Biphenyltetracarboxylic dianhydride, pyromellitic dianhydride, oxydiphthalic anhydride, benzophenone tetracarboxylic dianhydride, paraphenylene diamine, m-tolidine, 1,3-bisaminophenone A second polyamic acid solution to be used in preparing the first and second skin layers was prepared by polymerization of dianhydride acid and diamine components selected from sibenzene and oxydianiline.

A multilayer polyimide film in which the first skin layer and the 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, and then curing the solution. was manufactured.

However, here, the core layer was prepared by coextruding the first polyamic acid solution, and the first skin layer and the second skin layer were prepared by coextruding the second polyamic acid solution.

When preparing the polyamic acid, the solvent is generally an amide-based solvent, such as an aprotic solvent, such as N,N'-dimethylformamide, N,N'-dimethylacetamide, N-methyl-pyrroly money, or a combination thereof.

The input form of the dianhydride acid and diamine component can be added in the form of powder, lump or solution, and it is preferable to introduce the reaction in the form of a powder to proceed with the reaction in the initial stage of the reaction, and then add in the form of a solution to adjust the polymerization viscosity thereafter. .

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

Examples of the catalyst used include tertiary amines (eg, isoquinoline, β-picoline, pyridine, etc.), and examples of the dehydrating agent include anhydrous acid, but are not limited thereto.

Examples and Comparative Examples

As shown in Table 1 (components and composition ratio of core layer) and Table 2 (components and composition ratio of skin layer), dianhydride components of the core layer and skin layer in Examples 1 to 6 and Comparative Examples 1 to 9 And by adjusting the content of the diamine component, a multi-layer polyimide film was prepared according to Preparation 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 prepared the same.

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

	core layer
	Dianhydride (mol %)				Diamine (mol %)
	PMDA	BPDA	BTDA	ODPA	ODA	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	ODA	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) in the width direction, and adhesive strength of the prepared polyimide film in the width direction were measured and are 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) Thermal expansion coefficient measurement

For the coefficient of thermal expansion (CTE), TA's thermomechanical analyzer Q400 model was used. After cutting the prepared multilayer polyimide film into a width of 4 mm and a length of 20 mm, 10 After the temperature was raised from 30 °C to 400 °C at a rate of °C/min, the slope was measured from 50 °C to 200 °C while cooling at a rate of 10 °C/min.

(2) Measurement of hygroscopic expansion coefficient

The hygroscopic expansion coefficient (CHE) was obtained by adjusting the humidity to 3% RH at 25°C and fully saturated under the minimum weight applied (about 1 g for a sample of 25 mm × 150 mm) so that the manufactured multilayer polyimide film would not loosen. After that, the humidity was adjusted to 90% RH and similarly saturated moisture was absorbed, and then the dimensions were measured, and the dimensional change rate was measured from both results.

(3) Measurement of adhesive strength

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

After etching the flexible metal foil laminate in the form of a rod with a width of 2 mm by a wet layering method, a 90 ° peel test was performed with a universal testing machine, and the adhesive force was measured 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 of 2.0 ppm/°C or more in the width direction and 6.0 ppm/°C or less, and a hygroscopic expansion coefficient in the width direction of 3.0 ppm/RH% or more and 6.0 ppm/°C or more. It is ppm/RH% or less, and the adhesive strength with copper foil is 0.8 kgf/cm or more.

In contrast, the polyimide films of Comparative Examples 1 to 8 and the multi-layer polyimide film of Comparative Example 9, which differ in component and/or composition ratio from those of the Examples, consisting of only one layer, have thermal expansion coefficient, hygroscopic expansion coefficient, and correlation with copper foil. In terms of adhesive strength, the multilayer polyimide film of the present application did not satisfy the required properties.

Therefore, the multilayer polyimide films of Examples 1 to 6 prepared within the appropriate range of the present application were excellent in thermal dimensional stability, dimensional stability against moisture, and adhesive strength with copper foil, but outside the appropriate range of the present application, It was confirmed that it was difficult to satisfy all of the thermal dimensional stability, moisture dimensional stability, and adhesive strength with the copper foil of the multilayer polyimide film.

That is, it was confirmed that a multilayer polyimide film that satisfies all of the various conditions that can be applied to the application field while having excellent dimensional stability and adhesion to the copper foil is a multilayer polyimide film manufactured within the appropriate scope of the present application.

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, Because it is not limited to examples, this does not limit the scope of the present invention. Therefore, the true technical protection scope of the present invention should be determined by the technical spirit of the appended claims. In addition, it will be clear to those skilled in the art that various substitutions, modifications and changes are possible within the scope of the technical spirit of the present invention, and it is obvious that parts easily changeable by those skilled in the art are also included in the scope of the present invention. .

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

Such a polyimide film can be applied to various fields requiring a polyimide film having excellent dimensional stability and adhesive strength, for example, a flexible metal foil laminate manufactured by a metallization method or an electronic component including such a flexible metal foil laminate.

Claims (9)

1. Including a first skin layer and a second skin layer respectively formed on one outer surface of the core layer and the opposite surface of the outer surface,

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

   Multi-layer polyimide film.
2. According to claim 1,

   The thermal expansion coefficient in the transverse direction (TD) is 2.0 ppm / ° C or more and 6.0 ppm / ° C or less,

   The transverse direction (TD) hygroscopic expansion coefficient is 3.0 ppm / RH% or more and 6.0 ppm / RH% or less,

   Multi-layer polyimide film.
3. According to claim 1,

   The core layer includes a dianhydride component including biphenyltetracarboxylic dianhydride (BPDA) and pyromellitic dianhydride (PMDA),

   Obtained by imidization reaction of a polyamic acid solution containing a diamine component including paraphenylene diamine (PPD) and m-tolidine,

   Multi-layer polyimide film.
4. According to claim 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 tetra A dianhydride component containing two or more selected from the group consisting of carboxylic dianhydride (BTDA);

   Obtained by imidation of 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),

   Multi-layer polyimide film.
5. According to claim 3,

   Based on 100 mol% of the total content of the dianhydride component, the content of the biphenyltetracarboxylic dianhydride is 40 mol% or more and 60 mol% or less, and the content of the pyromellitic dianhydride is 40 mol% more than 60 mol% or less,

   Based on 100 mol% of the total content of the diamine component, 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,

   Multi-layer polyimide film.
6. According to claim 4,

   Based on 100 mol% of the total content of the dianhydride component, the content of the biphenyltetracarboxylic dianhydride is 15 mol% or more and 85 mol% or less, and the content of the pyromellitic dianhydride is 15 mol% 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 100 mol% of the total content of the diamine component, the content of oxydianiline is 20 mol% or more and 100 mol% or less, and the content of 1,3-bisaminophenoxybenzene is 80 mol% or less,

   Multi-layer polyimide film.
7. According to any one of claims 1 to 6,

   The multilayer polyimide film is prepared by at least one selected from the group consisting of coextrusion and coating,

   Multi-layer polyimide film.
8. Comprising the multilayer polyimide film according to any one of claims 1 to 6 and an electrically conductive metal foil,

   Flexible metal foil laminate.
9. Including the flexible metal foil laminate according to claim 8,

   Electronic parts.