TW202406989A - Polyimide film, manufacturing method of the same, flexible metal foil laminate and electronic components including the same - Google Patents

Abstract

The present invention provides: a polyimide film having a surface hardness of 0.4 GPa to 0.6 GPa, as measured by a nanoindenter; and a method for producing same.

Description

Polyimide film, manufacturing method thereof, flexible metal foil laminate containing the same, and electronic components containing the same

The present invention relates to a polyimide film that is excellent in both dimensional stability and adhesion. More specifically, it relates to a polyimide film that has high surface hardness and minimizes the reduction in adhesion between normal temperature adhesion and heat-resistant adhesion. Amine film and method of making same.

Polyimide (polyimide: PI) is based on a rigid aromatic backbone and an amide ring with excellent chemical stability. It has the highest level of heat resistance, chemical resistance, electrical insulation, and chemical resistance among organic materials. , Weather-resistant polymer materials.

Polyimide films have attracted much attention as materials for various electronic devices requiring the aforementioned properties.

Microelectronic components using polyimide films can be, for example, flexible ultra-thin circuit substrates with high circuit integration, so as to cope with the weight reduction and miniaturization of electronic products. Polyimide films are particularly widely used as ultra-thin circuits. Insulating film for substrate.

The structure of the aforementioned ultra-thin circuit substrate is generally a circuit including metal foil formed on an insulating film. Broadly speaking, this ultra-thin circuit substrate is called a flexible metal foil clad laminate (Flexible Metal Foil Clad Laminate). , when a thin copper plate is used as the metal foil, in a narrow sense, it is also called Flexible Copper Clad Laminate (FCCL).

As a method of manufacturing a flexible metal foil-clad laminate, for example: (i) casting on a metal foil or casting in which polyamide acid, which is a polyimide precursor, is coated and then imidized. method; (ii) metallization method of directly setting a metal layer on a polyimide film by sputtering; and (iii) thermoplastic polyimide using heat and pressure to make the polyimide Lamination method of joining amine film to metal foil.

Especially the metallization method, for example, sputtering copper and other metals on a polyimide film with a thickness of 20 μm to 38 μm to sequentially deposit a tie layer and a seed layer to produce flexible metal coating. The foil laminate method has advantages in forming ultra-micro circuits with a circuit pattern pitch of 35 μm or less, and is being widely used to manufacture flexible coatings for COF (chip on film). Metal foil laminate.

Polyimide films used in flexible metal foil laminates based on metallization require high dimensional stability and adhesion to sputtered metal foils. However, polyimide films with high dimensional stability generally have a problem of low adhesion to sputtered metal foils.

Therefore, there is an urgent demand for a polyimide film that has both dimensional stability and excellent adhesion to sputtered metal foil.

In particular, it is necessary to minimize the reduction in adhesion to the sputtered metal foil caused by dimensional changes in the polyimide film during the sputtering process and subsequent processes.

The matters described in the background art above are intended to assist in understanding the background of the invention, and may include matters that are not prior art known to those of ordinary skill in the technical field.

[Prior technical literature] [Patent Document] Patent Document 1: Korean Patent Publication No. 10-2020-0120515.

[Technical Issue]

Therefore, the object of the present invention is to provide a polyimide film having both high dimensional stability and excellent adhesion.

In particular, the purpose is to provide a polyimide film that has excellent surface hardness and minimizes the reduction in adhesion to the sputtered metal foil during the sputtering process and subsequent processes.

However, the problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not mentioned can be clearly understood by those skilled in the art from the following description. [Technical solution]

In order to achieve the above object, one aspect of the present invention provides a polyimide film, wherein,

The surface hardness (hardness) measured with a nanoindenter is 0.4 GPa or more and 0.6 GPa or less.

Another aspect of the present invention provides a method for manufacturing a polyimide film, which includes: (a) step, polymerizing a dianhydride component and a diamine component in an organic solvent to produce polyamic acid, wherein the aforementioned dianhydride component includes diphenyltetracarboxylic dianhydride (BDPA) and pyromellitic dianhydride (PMDA) ), the aforementioned diamine component includes two selected from the group consisting of p-phenylenediamine (PPD), diaminodiphenyl ether (ODA) and 1,3-bis(aminophenoxy)benzene (TPE-R). more than one species; and (b) Step: imidizing the aforementioned polyamide acid.

Another aspect of the present invention provides a flexible metal foil laminate including the aforementioned polyimide film and conductive metal foil.

Yet another aspect of the present invention provides an electronic component including the aforementioned flexible metal foil-clad laminate. [Effects of the invention]

The present invention provides a polyimide film in which the ratio, reaction ratio, etc. of the dianhydride and diamine components are adjusted, thereby providing a polyimide film with excellent dimensional stability and adhesion.

This polyimide film can be applied to various fields requiring polyimide films with excellent dimensional stability and adhesion. For example, it can be applied to flexible metal foil laminates manufactured according to the metallization method or including This flexible metal foil laminate is used for electronic components.

The terms or words used in this specification and the scope of the patent application shall not be limited to the common meaning or dictionary meaning, but shall be based on the concept that "the inventor can appropriately define the terms in order to describe his own invention in the best way." principles shall only be interpreted as meanings and concepts consistent with the technical ideas of the present invention.

Therefore, the configuration of the embodiments described in this specification is only one of the best embodiments of the present invention, and does not all represent the technical ideas of the present invention. Therefore, it should be understood that there will be various equivalents that can replace it at the time of this application. and modifications.

In this specification, singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as "including", "having" or "having" are intended to specify the presence of features, numbers, steps, components or combinations thereof, and should be understood as not excluding one or more other features in advance. or the existence or additional possibility of numbers, steps, components, or combinations thereof.

In this specification, "dianhydride" is meant to include its precursors or derivatives, which may not technically be dianhydrides, but nevertheless react with diamines to form polyamides that can Convert to polyimide again.

In this specification, "diamine" is meant to include its precursors or derivatives, which may not technically be diamines, but nevertheless react with dianhydrides to form polyamides, which may Convert to polyimide again.

In this specification, when an amount, concentration or other value or parameter is given by enumerating a range, a preferred range, or a preferred upper limit and a preferred lower limit, whether or not the range is otherwise disclosed, it should be understood that the specific disclosure is All ranges formed by any pair of the upper limit of any range or better value and the lower limit of any range or better value.

Where reference is made in this specification to a range of values, unless otherwise stated, the range is meant to include its endpoints and all integers and fractions within the range. It is intended that the scope of the invention is not limited to the specific values mentioned in defining the range.

In this specification, "to" and "~" in "a to b" and "a~b" indicating numerical ranges are defined as ≥a and ≤b.

The surface hardness (hardness) measured by a nanoindenter of the polyimide film according to an embodiment of the present invention can be between 0.4 GPa and 0.6 GPa.

For example, the aforementioned surface hardness may be 0.45 GPa or more, 0.5 GPa or more, or 0.55 GPa or more.

If it exceeds the aforementioned surface hardness range, it will be difficult to deposit the metal foil, and the normal temperature adhesion of the aforementioned polyimide film will be weakened. If it is lower than the aforementioned surface hardness range, the thermal stability and heat-resistant adhesion of the aforementioned polyimide film will decrease. low.

In an implementation example, the normal temperature adhesion between the polyimide film and the metal foil can be between 0.6 kgf/cm and 0.9 kgf/cm, and the heat-resistant adhesion between the polyimide film and the metal foil can be between 0.3 and 0.5 kgf/cm. /cm below.

The aforementioned normal temperature adhesion can be measured at normal temperature (15~25°C) after depositing metal foil (for example, copper foil) on the aforementioned polyimide film through a sputtering process. of adhesion.

In addition, the aforementioned heat-resistant adhesion can be obtained by depositing metal foil (for example, copper foil) on the aforementioned polyimide film through a sputtering process, and then leaving it at high temperature (100~200°C) for a long time (100~300 hours). The adhesion of the aforementioned polyimide film to the metal foil was measured.

As an example, the normal temperature adhesion force may be 0.6 kgf/cm or more and 0.83 kgf/cm or less, and the heat-resistant adhesion force may be 0.45 kgf/cm or more and 0.50 kgf/cm or less.

If it exceeds or falls below the aforementioned normal temperature and/or heat-resistant adhesion range, problems may occur in the production process of products to which the aforementioned polyimide film is applied.

In an implementation example, the adhesion reduction rate expressed by the following mathematical formula 1 may be less than 50%, and the thermal expansion coefficient may be greater than 1 ppm/℃ and less than or equal to 15 ppm/℃.

[Mathematical formula 1] Adhesion reduction rate (%) = [(room-temperature adhesion to metal foil - heat-resistant adhesion to metal foil)/room-temperature adhesion to metal foil]*100

The adhesion reduction rate may be, for example, 45% or less, 40% or less, 35% or less, 30% or less, 25% or less, or 20% or less.

On the other hand, the thermal expansion coefficient may be, for example, 4.5 ppm/°C or more and 10 ppm/°C or less.

If the coefficient of thermal expansion exceeds the range of the thermal expansion coefficient, the heat resistance stability of the deposited metal foil and polyimide film will be reduced. If it is lower than the range of the coefficient of thermal expansion, the adhesion of the polyimide film and the metal foil at room temperature will be reduced.

In an implementation example, the polyimide film of the present application can be obtained by subjecting a polyimide solution containing a dianhydride component and a diamine component to an imidization reaction, wherein the dianhydride component includes biphenyltetracarboxylic acid. Dianhydride (3,3',4,4'-Biphenyltetracarboxylic dianhydride, BPDA) and pyromellitic dianhydride (PMDA), the aforementioned diamine components include p-phenylenediamine (PPD), diamine group Two or more types of the group consisting of diphenyl ether (ODA) and 1,3-bis(aminophenoxy)benzene (TPE-R).

However, the dianhydride component of the polyimide film of the present application may not include benzophenone tetracarboxylic dianhydride (BTDA) and oxybisphthalic anhydride (BTDA). 4,4'-Oxydiphthalic anhydride, ODPA).

In addition, the diamine component of the polyimide film of the present application may not include m-tolidine (MTD).

For example, the diamine component of the polyimide film can be a combination of p-phenylenediamine and diaminodiphenyl ether, or p-phenylenediamine and 1,3-bis(aminophenoxy)benzene (TPE- R) combination.

The polyimide chain derived from diphenyltetracarboxylic dianhydride has a structure named charge transfer complex (CTC), that is, electron donor (electron donnor) and electron acceptor (electron acceptor) Regular linear structures arranged close to each other strengthen intermolecular interactions.

In addition, pyromellitic dianhydride is a dianhydride component with a relatively rigid structure and can impart appropriate elasticity to the polyimide film, so it is preferred.

On the other hand, diphenyltetracarboxylic dianhydride contains two benzene rings corresponding to the aromatic moiety, and conversely, pyromellitic dianhydride contains one benzene ring corresponding to the aromatic moiety.

In the dianhydride component, the increase in the content of pyromellitic dianhydride, based on the same molecular weight, can be understood as an increase in the amide imine groups in the molecule, which can be understood as the increase in the polyimide polymer chain. The ratio of the acyl imine groups derived from the pyromellitic dianhydride is relatively higher than that of the amide imine groups derived from biphenyltetracarboxylic dianhydride.

In an implementation example, based on the total content of the dianhydride component of 100 mol%, the content of the aforementioned biphenyltetracarboxylic acid dianhydride can be more than 40 mol% and less than 99 mol%, and the aforementioned pyromellitic acid dianhydride can be The content of the anhydride may be 1 mol% or more and 60 mol% or less. Based on the total content of the diamine component of 100 mol%, the content of the p-phenylenediamine may be 40 mol% or more and 95 mol%. % or less, the content of the aforementioned diaminodiphenyl ether may be 30 mol% or less, and the content of the aforementioned 1,3-bis(aminophenoxy)benzene may be 60 mol% or less.

For example, based on the total content of the dianhydride component of 100 mol%, the content of the diphenyltetracarboxylic acid dianhydride may be between 50 mol% and 97 mol%, and the content of the pyromellitic acid dianhydride may be It is more than 3 mol% and less than 50 mol%.

In addition, based on 100 mol% of the total content of the aforementioned diamine components, the content of the aforementioned p-phenylenediamine may be 55 mol% or more and 87 mol% or less, and the content of the aforementioned diaminodiphenyl ether may be 13 mol%. mol% or less, and the content of the aforementioned 1,3-bis(aminophenoxy)benzene may be 45 mol% or less.

Among the aforementioned dianhydride components and diamine components, if the content of short structural monomers such as the aforementioned p-phenylenediamine and the aforementioned pyromellitic dianhydride increases, the surface hardness of the aforementioned polyimide film will increase and the thermal expansion coefficient will decrease. tendency.

On the other hand, if the content of soft-structured monomers such as the diaminodiphenyl ether and the diphenyltetracarboxylic dianhydride in the dianhydride component and the diamine component increases, the polyimide film may deteriorate. The surface hardness tends to decrease and the thermal expansion coefficient increases.

In the present invention, polyamide acid can be produced by, for example, the following methods: (1) Method: add the entire amount of the diamine component into the solvent, and then add the dianhydride component to make it substantially equimolar with the diamine component and polymerize; (2) Method: add the entire amount of the dianhydride component into the solvent, and then add the diamine component to make it substantially equimolar with the dianhydride component and polymerize; (3) Method: After adding a part of the diamine component to the solvent, mix a part of the dianhydride component at a ratio of about 95 to 105 mol% relative to the reaction component, then add the remaining diamine component, and then add The remaining dianhydride component is such that the diamine component and the dianhydride component are substantially equimolar and polymerized; (4) Method: After adding the dianhydride component to the solvent, mix a part of the diamine compound at a ratio of 95 to 105 mol% relative to the reaction components, then add the other dianhydride component, and then add the remaining diamine component. The diamine component and the dianhydride component are made to be substantially equimolar and polymerized; (5) A method of reacting a part of a diamine component and a part of a dianhydride component in a solvent so that one of them is in excess to form a first composition, and reacting a part of a diamine component and a part of a dianhydride component in another solvent to form a first composition. After making an excess of one of them to form the second composition, the first and second compositions are mixed to complete the polymerization. At this time, in this method, when forming the first composition, if the diamine component is excessive, then 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 they react with all the diamines used. The component and the dianhydride component become substantially equimolar and polymerize.

However, the polymerization method is not limited to the above examples, and any known method can of course be used for the production of the polyamide.

In a specific example, the manufacturing method of the polyimide film of the present invention may include: (a) step, polymerizing a dianhydride component and a diamine component in an organic solvent to produce polyamic acid, wherein the aforementioned dianhydride component includes diphenyltetracarboxylic dianhydride and pyromellitic acid dianhydride, and the aforementioned diamine component Including two or more selected from the group consisting of p-phenylenediamine (PPD), diaminodiphenyl ether (ODA) and 1,3-bis(aminophenoxy)benzene (TPE-R); and (b) Step: imidizing the aforementioned polyamide acid.

In an implementation example, based on the total content of the dianhydride component of 100 mol%, the content of the aforementioned biphenyltetracarboxylic acid dianhydride can be more than 40 mol% and less than 99 mol%, and the aforementioned pyromellitic acid dianhydride can be The content of the anhydride may be 1 mol% or more and 60 mol% or less. Based on the total content of the diamine component of 100 mol%, the content of the p-phenylenediamine may be 40 mol% or more and 95 mol%. % or less, the content of the aforementioned diaminodiphenyl ether may be 30 mol% or less, and the content of the aforementioned 1,3-bis(aminophenoxy)benzene may be 60 mol% or less.

On the other hand, the surface hardness (hardness) of the polyimide film measured with a nanoindenter can be 0.4 GPa or more and 0.6 GPa or less, and the normal temperature adhesion to the metal foil can be 0.6 kgf/cm Above and below 0.9 kgf/cm, the heat-resistant adhesion to metal foil can be above 0.3 kgf/cm and below 0.5 kgf/cm.

In the present invention, the polymerization method of polyamic acid as described above can be defined as a random polymerization method. The polyimide film of the present invention made of polyamic acid is produced by the process as described above. , due to the effect of the present invention that improves mechanical properties, heat resistance and chemical resistance, it can be better applied.

On the other hand, the solvent used for synthesizing polyamic acid is not particularly limited and any solvent can be used as long as it dissolves polyamic acid. However, amide solvents are preferred.

Specifically, the aforementioned solvent may be an organic polar solvent. Specifically, it may be an aprotic polar solvent. For example, it may be selected from the group consisting of N,N-dimethylformamide (DMF), N,N- Dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), p-chlorophenol, o-chlorophenol, γ-butyrolactone (GBL), diglyme (Diglyme) One or more types, but are not limited thereto, and may be used alone or in combination of two or more types as needed.

In one example, N,N-dimethylformamide and N,N-dimethylacetamide are particularly preferred as the aforementioned solvents.

In addition, in the polyamide manufacturing process, fillers other than nanosilica can also be added to improve various properties of the film such as sliding properties, thermal conductivity, corona resistance, and ring hardness. The added filler material is not particularly limited, and preferred examples include titanium oxide, aluminum oxide, silicon nitride, boron nitride, calcium hydrogen phosphate, calcium phosphate, mica, etc.

The particle size of the filler material is not particularly limited and can be determined according to the characteristics of the membrane to be modified and the type of filler material added. Generally speaking, the average particle diameter is 0.05 μm to 100 μm, preferably 0.1 μm to 75 μm, more preferably 0.1 μm to 50 μm, especially preferably 0.1 μm to 25 μm.

If the particle size is less than this range, it is difficult to exhibit the modification effect, and if it exceeds this range, the surface properties may be greatly damaged or the mechanical properties may be greatly reduced.

In addition, the amount of filler added is not particularly limited and can be determined based on the characteristics of the membrane to be modified or the particle size of the filler. Generally speaking, 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 relative to 100 parts by weight of polyimide.

If the amount of filler added is less than this range, it will be difficult to exhibit the modification effect of the filler. If it exceeds this range, there is a possibility that the mechanical properties of the film will be greatly damaged. The method of adding the filler is not particularly limited, and any known method can be used.

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

In addition, it can also be produced by a composite imidization method in which a thermal imidization method and a chemical imidization method are used together.

The aforementioned thermal imidization method is a method in which a heat source such as hot air or an infrared dryer is used to induce an imidization reaction without using a chemical catalyst.

The aforementioned thermal imidization method can heat-treat the aforementioned gel film at a variable temperature ranging from 100 to 600°C, so that the amide groups present in the gel film can be imidized. Specifically, the gel film can be heat-treated at a temperature ranging from 200 to 600°C. At 500°C, in more detail, heat treatment may be performed at 300 to 500°C to achieve amide imidization of the amide groups present in the gel film.

However, during the formation of the gel film, a portion of the amide acid (about 0.1 mol% to 10 mol%) will be imidized. For this purpose, a variable temperature ranging from 50°C to 200°C can be used. The polyamide composition is dried below, which may also be included in the category of the aforementioned thermal imidization method.

As for the chemical imidization method, the polyimide membrane can be produced by using a dehydrating agent and an imidization agent according to methods known in the industry. Among them, the so-called "dehydrating agent" refers to a substance that promotes the ring-closing reaction by dehydrating polyamide. Non-limiting examples of this include aliphatic acid anhydrides, aromatic acid anhydrides, N, N' -Dialkylcarbodiimides, halogenated lower aliphatic, halogenated lower fatty acid anhydrides, arylphosphine dihalides and thionyl halides, etc. Among them, from the perspective of availability and cost, aliphatic acid anhydrides are preferred. Non-limiting examples thereof include acetic anhydride (or anhydrous acetic acid, AA), propionic anhydride, lactic anhydride, etc., which can be used alone. Or use two or more in combination.

In addition, the term "imidating agent" means a substance that has the effect of promoting the ring-closing reaction of polyamide acid. For example, it can be an imine such as an aliphatic tertiary amine, an aromatic tertiary amine, and a heterocyclic tertiary amine. class ingredients. Among these, heterocyclic tertiary amines are preferred from the viewpoint of reactivity as a catalyst. Non-limiting examples of heterocyclic tertiary amines include quinoline, isoquinoline, β-methylpyridine (BP), pyridine, etc., which may be used alone or in a mixture of two or more.

The amount of the dehydrating agent added is preferably within the range of 0.5 to 5 moles, and particularly preferably within the range of 1.0 moles to 4 moles based on 1 mole of the amide group in the polyamic acid. In addition, the amount of the imidizing agent added is preferably within the range of 0.05 mol to 2 mol relative to 1 mol of the amide group in the polyamic acid, and is particularly preferably 0.2 mol to 1 mol. within ear range.

If the dehydrating agent and imidization agent exceed the above ranges, chemical imidization will be insufficient, cracks will be formed in the polyimide film produced, and the mechanical strength of the film will also decrease. In addition, if these addition amounts exceed the aforementioned range, imidization will proceed too quickly, and in this case, it will be difficult to cast into a film form or the produced polyimide film will exhibit brittle characteristics. Not recommended.

As an example of the composite imidization method, a dehydrating agent and an imidization agent can be added to the polyamic acid solution, and then heated at 80 to 200°C, preferably 100 to 180°C, to partially cure. After drying, it is heated at 200 to 400°C for 5 to 400 seconds to produce a polyimide film.

The present invention provides a flexible metal foil-clad laminate including the above-mentioned polyimide film and conductive metal foil.

The metal foil used is not particularly limited, but for example, when the multilayer film of the present invention is used for electronic equipment or electrical equipment, it may include copper or copper alloys, stainless steel or alloys thereof, nickel or nickel alloys (also Metal foil including alloy 42), aluminum or aluminum alloys.

In ordinary flexible metal foil-clad laminates, copper foils called rolled copper foil and electrolytic copper foil are often used, and they can also be preferably used in the present invention. In addition, the surface of these metal foils can also be covered with an anti-rust layer, heat resistance or adhesive layer.

In the present invention, the thickness of the metal foil is not particularly limited as long as it is a thickness that can fully function according to its use.

The flexible metal foil-clad laminate of the present invention may include a metal foil laminated on one side of the polyimide film or an adhesive layer containing thermoplastic polyimide added to one side of the polyimide film. The metal foil is laminated while being attached to the adhesive layer.

The present invention also provides an electronic component including the aforementioned flexible metal foil-clad laminate as an electrical signal transmission circuit.

The functions and effects of the invention are described in more detail below through specific embodiments of the invention. However, such embodiments are only provided as examples of the invention, and the scope of rights of the invention is not limited thereby.

Production Example 1: Production of polyimide film.

Inject nitrogen into a 500 ml reactor equipped with a stirrer and nitrogen injection/discharge pipe, then add DMF. After setting the reactor temperature to 30°C, select p-phenylenediamine (PPD) and m-toluidine as the diamine component. (m-tolidine, MTD), 1,3-bis(aminophenoxy)benzene (TPE-R) and diaminodiphenyl ether (ODA) are put in together. As the dianhydride component, diphenyl tetrahydrofuran is selected. Add a portion of formic dianhydride (BPDA), pyromellitic dianhydride (PMDA) and oxydiphthalic anhydride (ODPA) and confirm that they are completely dissolved.

Then, in a nitrogen atmosphere, the reactor temperature was raised to 40° C., and stirring was continued for 120 minutes, thereby producing a polyamide solution.

To the polyamide acid solution produced in this way, 3 moles of acetic anhydride and 1 mole of isoquinoline were added based on 1 mole of amide group to obtain a precursor composition for a polyimide film. .

The precursor composition for the polyimide film was cast on a SUS plate using a doctor blade, and dried at 110° C. for 4 minutes to produce a gel film.

After the gel film was separated from the SUS plate, the gel film was heat-treated at 380° C. for 8 minutes to produce a polyimide film having a thickness of 35 μm.

The thickness of the produced polyimide film was measured using an Anritsu Electric Film Thickness Tester.

<Examples 1 to 3 and Comparative Examples 1 to 4>

Production was carried out according to the previously described production examples, and the contents of the diamine monomer and dianhydride monomer were adjusted as shown in Table 1 below.

[Table 1] Dianhydride (mol%) Diamine (mol%) PMDA BPDA ODPA ODA TPE-R MTD PPD Example 1 25 75 - - 45 - 55 Example 2 3 97 - - 45 - 55 Example 3 50 50 - 13 - - 87 Comparative example 1 50 50 - - - 40 60 Comparative example 2 50 50 - 100 - - - Comparative example 3 25 75 - 55 45 - - Comparative example 4 25 50 25 55 45 - -

Production Example 2: Production of flexible metal foil laminate.

A copper thin film layer with a thickness of about 80 to 300 nm was deposited by sputtering on the polyimide films of Examples 1 to 3 and Comparative Examples 1 to 4 produced in Production Example 1 as a copper seed crystal for electroplating electrodes ( seed) layer, and form a copper conductive layer with a thickness of approximately 8 to 9 μm through electroplating.

(1) Thermal expansion coefficient measurement

The coefficient of thermal expansion (CTE) was measured using a TA company thermomechanical analyzer Q400. The polyimide films of Examples 1 to 3 and Comparative Examples 1 to 4 produced in Production Example 1 were cut into a width of 4 mm and a length of 20 mm. Finally, a tension of 0.05N was applied under a nitrogen atmosphere, and the temperature was raised from 30°C to 400°C at a rate of 10°C/min and then cooled again at a rate of 10°C/min. The slope in the range from 50°C to 200°C was measured at the same time ( Dimensional change rate caused by temperature change between 50℃ and 200℃ (ppm/℃)).

(2) Surface hardness measurement

After the polyimide films of Examples 1 to 3 and Comparative Examples 1 to 4 produced in Production Example 1 were cut into a width of 100 mm and a length of 100 mm, the surface hardness was measured using the KLA-Tenco iNano nanoindentation instrument. An indenter can measure surface hardness by measuring the force exerted on the probe as it is pressed into the sample.

(3) Adhesion measurement at room temperature

A wet etching process was applied to the flexible metal plate laminate manufactured according to Production Example 2 using the polyimide films of Examples 1 to 3 and Comparative Examples 1 to 4, and etched into a rod shape with a width of 2 mm, and then used The Universal Testing Machine measured adhesion at room temperature through a 90° peel test and stretching at a speed of 20mm/min.

The aforementioned wet etching process is carried out in the following order, that is, a rod-shaped coating film with a width of 2 mm is attached to the aforementioned flexible metal foil laminate, and an etching liquid (ferric chloride [ferric chloride III]) is sprayed to etch the metal , thereby forming a rod-shaped pattern, and then removing the coating film.

(4) Heat-resistant adhesion measurement

A wet etching process was applied to the flexible metal plate laminate produced according to Production Example 2 using the polyimide films of Examples 1 to 3 and Comparative Examples 1 to 4. After etching into a rod shape with a width of 2 mm, the flexible metal plate laminate was etched at 150 Heat treatment at ℃ for 168 hours.

The aforementioned wet etching process is performed in the same manner as the aforementioned normal temperature adhesion measurement.

Then, a universal testing machine was used to perform a 90° peel test and the heat-resistant adhesion was measured by stretching at a speed of 20 mm/min.

The thermal expansion coefficient (CTE), surface hardness, normal temperature adhesion and heat-resistant adhesion of the polyimide films of Examples 1 to 3 and Comparative Examples 1 to 4 produced in Production Example 1 measured by the above measurement method are shown below. Table 2.

In addition, the reduction in adhesion calculated according to the above-mentioned Mathematical Expression 1 is shown in Table 2 below.

[Table 2] CTE (ppm/℃) Surface hardness (GPa) Adhesion at room temperature (kgf/cm) Heat-resistant adhesion (kgf/cm) Adhesion reduction (%) Example 1 10.0 0.48 0.60 0.50 17 Example 2 8.6 0.51 0.83 0.45 46 Example 3 4.5 0.55 0.73 0.45 33 Comparative example 1 1.0 0.69 0.57 0.53 36 Comparative example 2 33.5 0.33 0.92 0.28 70 Comparative example 3 34.5 0.39 1.01 0.24 76 Comparative example 4 37.1 0.38 0.93 0.27 71

The measurement results show that the polyimide films of Examples 1 to 3 exhibit a thermal expansion coefficient of greater than 1 ppm/℃ and less than or equal to 15 ppm/℃, a surface hardness of more than 0.4 Gpa and less than 0.6 Gpa, and a surface hardness of more than 0.6 kgf/cm. Room temperature adhesion below 0.9 kgf/cm, heat-resistant adhesion above 0.3 kgf/cm and below 0.5 kgf/cm, and adhesion reduction characteristics below 50%.

In comparison, the polyimide films of Comparative Examples 1 to 4 cannot satisfy any one or more of the thermal expansion coefficient, surface hardness, adhesion at room temperature, heat-resistant adhesion and adhesion reduction characteristics of the polyimide film applied for in this case. Characteristic range of imine membranes.

Therefore, it was confirmed that the multilayer polyimide films of Examples 1 to 3 produced within the appropriate range of this case were excellent in thermal dimensional stability, dimensional stability against moisture, and adhesion to copper foil, but exceeded that of this case. Even within the appropriate range, it is difficult to fully satisfy the thermal dimensional stability, dimensional stability against moisture, and adhesion to copper foil of the multilayer polyimide film in this case.

That is, it was confirmed that a multilayer polyimide film that has excellent dimensional stability and adhesion to copper foil and satisfies all the various conditions applicable to application fields is a polyimide produced within the appropriate range of this case. membrane.

The embodiments of the polyimide film and the manufacturing method of the polyimide film of the present invention are only preferred embodiments that enable those of ordinary skill in the technical field to which the present invention belongs to easily implement the present invention, and are not limited to the foregoing embodiments. Therefore, the patentable scope of the present invention is not limited thereby. Therefore, the true technical protection scope of the present invention should be determined based on the technical ideas of the accompanying patent application scope. In addition, it is self-evident to practitioners that various substitutions, deformations and changes can be made without departing from the scope of the technical idea of the present invention. Parts that can be easily changed by practitioners are also included in the patent scope of the present invention. , which is self-evident.

without

without

without.

Claims (11)

A polyimide film, the surface hardness of the polyimide film measured by a nanoindentation instrument is 0.4 GPa or more and 0.6 GPa or less. The polyimide film according to claim 1, wherein the adhesion between the polyimide film and the metal foil at room temperature is 0.6 kgf/cm or more and 0.9 kgf/cm or less. The heat-resistant adhesion is 0.3 kgf/cm or more and 0.5 kgf/cm or less. The polyimide film according to claim 1, wherein the adhesion reduction rate expressed by the following mathematical formula 1 is less than 50%, and the thermal expansion coefficient is greater than 1 ppm/℃ and less than or equal to 15 ppm/℃, [Mathematical formula 1] Adhesion reduction rate (%) = [(room-temperature adhesion to metal foil - heat-resistant adhesion to metal foil)/room-temperature adhesion to metal foil]*100. The polyimide film according to claim 1, wherein the polyimide film is obtained by subjecting a polyamide acid solution containing a dianhydride component and a diamine component to an imidization reaction, wherein the above-mentioned The dianhydride component includes diphenyltetracarboxylic dianhydride and pyromellitic dianhydride. The aforementioned diamine component includes p-phenylenediamine (PPD), diaminodiphenyl ether (ODA) and 1,3-bis(amine). Two or more types of the group consisting of phenoxy)benzene (TPE-R). The polyimide film according to claim 4, wherein the content of the biphenyltetracarboxylic dianhydride is 40 mol% or more and 99 mol% based on the total content of the dianhydride component of 100 mol%. Hereinafter, the content of the aforementioned pyromellitic dianhydride is 1 mol% or more and 60 mol% or less. Based on the total content of the diamine component of 100 mol%, the content of the aforementioned p-phenylenediamine is 40 mol%. % or more and 95 mol% or less, the content of the aforementioned diaminodiphenyl ether is less than 30 mol%, and the content of the aforementioned 1,3-bis(aminophenoxy)benzene is less than 60 mol%. A method for manufacturing a polyimide film, which includes the following steps: (a) step, polymerizing a dianhydride component and a diamine component in an organic solvent to produce polyamic acid, wherein the aforementioned dianhydride component includes diphenyltetracarboxylic dianhydride and pyromellitic acid dianhydride, and the aforementioned diamine component Including two or more selected from the group consisting of p-phenylenediamine (PPD), diaminodiphenyl ether (ODA) and 1,3-bis(aminophenoxy)benzene (TPE-R); and (b) Step: imidizing the aforementioned polyamide acid. The method for manufacturing a polyimide film according to claim 6, wherein the content of the biphenyltetracarboxylic dianhydride is 40 mol% or more and 99 mol% based on the total content of the dianhydride component of 100 mol%. Mol% or less, the content of the aforementioned pyromellitic dianhydride is more than 1 mol% and less than 60 mol%, based on the total content of the aforementioned diamine component of 100 mol%, the content of the aforementioned p-phenylenediamine is: More than 40 mol% and less than 95 mol%, the content of the aforementioned diaminodiphenyl ether is less than 30 mol%, and the content of the aforementioned 1,3-bis(aminophenoxy)benzene is less than 60 mol% . The manufacturing method of a polyimide film as described in claim 6, wherein the surface hardness measured by a nanoindentation instrument is 0.4 GPa or more and 0.6 GPa or less, and the normal temperature adhesion to the metal foil is 0.6 kgf/cm or more , 0.9 kgf/cm or less, and the heat-resistant adhesion to metal foil is 0.3 kgf/cm or more and 0.5 kgf/cm or less. The method for manufacturing a polyimide film according to claim 6, wherein the adhesion reduction rate expressed by the following mathematical formula 1 is 50% or less, and the thermal expansion coefficient is greater than 1 ppm/℃ and less than or equal to 15 ppm/℃, [Mathematical formula 1] Adhesion reduction rate (%) = [(room-temperature adhesion to metal foil - heat-resistant adhesion to metal foil)/room-temperature adhesion to metal foil]*100. A flexible metal foil laminate, which includes the polyimide film and conductive metal foil as described in any one of claims 1 to 5. An electronic component including the flexible metal foil laminate according to claim 10.