JP2004124091A - Polyimide film, its manufacturing method and its use - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polyimide film which prevents warping or curling from occurring in the processing course into a TAB (Tape Automated Bonding) tape or a flexible printed wiring board. <P>SOLUTION: The polyimide film according to this invention, which comprises 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride, first fulfills all of that the mean coefficient of linear expansion at 100°C-200°C is ≥18 ppm/°C and ≤28 ppm/°C, that the modulus of elasticity is not less than 4.5 GPa, and that the coefficient of expansion caused by moisture absorption is not more than 13 ppm. The polyimide film which prevents warping or curling from occurring can be realized by fulfilling all of these three physical properties. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a polyimide film that has come to be frequently used as an insulating material with the weight reduction and miniaturization of various electronic devices, and a method for producing the polyimide film and a typical example of its use. In particular, the present invention relates to a polyimide film used as a base film processed into a flexible printed wiring board (TAB) or a tape automated bonding (TAB) tape, and an example of a method of manufacturing and using the polyimide film.

Conventionally, flexible printed wiring boards (abbreviated as FPC) have been used mainly by being folded into a narrow space inside a camera, taking advantage of its flexibility. However, in recent years, since FPCs are widely used in driving units of flexible disk drives (FDD), hard disk drives (HDD), copiers, printers, etc., it is possible to further improve the sliding and bending characteristics of FPCs. Is required.

FPC is based on a resin film, and this resin film is also called a base film. For the purpose of improving the slidability and flexibility, a polyimide film made of polyimide having high flexibility in chemical structure may be used as the base film.

Here, as the above-mentioned polyimide film, those having various physical properties have been developed. In particular, a polyimide film used as a base film in an FPC processing step by a tape automated bonding method (abbreviated as a TAB method). Is required to have the following three physical properties.

(1) Moderate thermal expansion property Generally, polyimide having high flexibility has a high thermal expansion property, that is, a linear expansion coefficient is large, so that FPC using a polyimide film as a base film has a drawback that warpage or curling easily occurs. ing. Conversely, when a resin film is formed by selecting a polyimide having a small coefficient of linear expansion and using this as a base film, since the flexibility of the film itself is lost, the base film becomes very fragile, and However, there is a disadvantage that the flexibility of the obtained FPC is reduced.

By the way, in recent years, the above-mentioned TAB method has attracted attention as a technology capable of responding to increase in the number of pins, miniaturization, and high-density mounting of semiconductor devices. In the TAB method, a hole (device hole) for mounting a semiconductor chip such as an LSI is provided in a long resin film, a very thin copper foil lead is formed thereon, and the LSI is inserted through the copper foil lead. Etc. and a printed wiring board. In such a TAB method, a film carrier tape (abbreviated as FC tape) having a three-layer structure of a protective layer, an adhesive layer, and an organic insulating film layer (base film layer) is generally used.

ＦＣ The above FC tape is processed into a TAB tape to be used in the TAB method. The processing step generally includes the following eight steps. That is, 1) a step of forming a sprocket hole for transporting the tape by punching an FC tape and a device hole for mounting a semiconductor chip, 2) removing a protective layer and laminating a copper foil, and then applying an adhesive. Curing step (copper foil laminating step), 3) forming a copper foil into a predetermined pattern (arranged pattern) by applying a resist, etching the copper foil and stripping the resist (arranged pattern forming step), 4 ) Plating step, 5) inner lead bonding step, 6) resin sealing step, 7) punching step, and 8) outer lead bonding step. Through such processing steps, an LSI or the like is mounted on the TAB tape. The laminate obtained after the step 2) is referred to as a flexible copper-clad laminate (abbreviated as FCCL).

In the above-described processing step, warping or curling of the FCCL or TAB tape may occur. Such warping or curling is one of the biggest causes of mounting failure when mounting an LSI or the like on the TAB tape. . That is, such warpage or curl causes various defects in a process requiring dimensional accuracy. Specifically, for example, in the 3) arrangement pattern forming step, a formation failure occurs when forming the copper foil in the arrangement pattern, and in the 5) inner lead bonding step or 6) the outer lead bonding step, And so on. Further, since the actual process is performed on a reel-to-reel basis, tension is applied in the longitudinal direction of the TAB tape. Therefore, the warp and the curl in the tape longitudinal direction can be corrected, but the warp and the curl in the tape width direction cannot be corrected.

Thus, it can be said that a polyimide film used for a TAB tape or an FPC preferably has an appropriate thermal expansion property, and its linear expansion coefficient is not so large as to cause warpage or curl. It must be within a range that is not small enough to lose its properties. Specifically, the range of such a linear expansion coefficient is desirably 18 ppm / ° C. or more and 28 ppm / ° C. or less.

(2) Small water absorption / hygroscopicity If the water absorption of the base film is high, internal stress is accumulated in the adhesive layer sandwiched between the base film and the copper foil after the above 2) copper foil laminating step. Problems arise. This internal stress is accumulated as follows. That is, 2) In the copper foil laminating step, the base film is dried immediately after the curing reaction of the adhesive is completed and the base film is dried immediately after being taken out of the curing heating furnace, so that the base film is fixed to the copper foil without distortion. ing. Here, when the copper foil is left in a laminated state, the base film expands and absorbs moisture with time. On the other hand, the copper foil does not undergo moisture expansion and expansion, and has high rigidity as compared with the film and hardly undergoes dimensional change due to expansion of the film. Therefore, internal stress is accumulated in the adhesive layer sandwiched between the base film and the copper foil.

Therefore, in this state, if a 3) arrangement pattern forming step is performed, drying and moisture absorption are repeated, so that when a wiring pattern is formed on the copper foil by etching, the stress in the portion where the copper foil is removed is released. Dimensional change occurs. Therefore, even if a photomask is used to form a wiring pattern, a pattern larger than this photomask dimension may be formed, or warpage or curling may occur. As a result, a connection failure with the semiconductor device occurs. Such a dimensional change causes a decrease in yield in the TAB processing step.

低 い Thus, low water absorption and low moisture absorption are required for the base film. Therefore, in processing into a TAB tape or FPC, a base film having a linear expansion coefficient within a proper range and a small hygroscopic expansion coefficient is required in order to prevent the above-mentioned inconvenience such as warpage and curling.

(3) Large elastic modulus Further, when the elastic modulus of the base film is small, that is, when the stiffness is weak, the base film may cause a dimensional change. This is because tension is applied in the longitudinal direction in the reel-to-reel manufacturing process. This dimensional change has an adverse effect on the processing step and causes warpage and curling. Therefore, for example, a polyimide film used for a TAB tape needs to have a large elastic modulus.

However, increasing the elastic modulus of the base film causes a problem that the coefficient of linear expansion decreases. This is because the elastic modulus and the coefficient of linear expansion greatly depend on the primary chemical structure (structure of repeating units) of the polyimide. That is, when a primary chemical structure of a polyimide that generally has a large elastic modulus is selected, the coefficient of linear expansion is reduced, and the flexibility of the polyimide film is lost, and the flexibility is reduced.

As described above, in the process of processing the FPC by the TAB method, three physical properties of (1) thermal expansion property, (2) water absorption / humidity property, and (3) elastic modulus are required to prevent warpage and curling. A harmonized polyimide film is required.

Here, Patent Document 1 discloses a polyimide film made of a polyimide obtained by using 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride as an acid component. In this polyimide film, It is reported to have "lower water absorption, lower moisture expansion coefficient, higher elastic modulus" and "low thermal expansion coefficient" (for example, see paragraph [0059] of the same document). The polyimide film reported in this publication uses pyromellitic dianhydride or 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride as an acid component, and p-phenylenediamine as a diamine component. It is formed using polyimide obtained by using 4,4′-oxydianiline and copolymerizing these acid component and diamine component.

Further, Patent Document 2 discloses “a block component of a polyimide comprising a rigid aromatic diamine compound and an aromatic tetracarboxylic acid compound, a flexible aromatic diamine compound and at least two kinds of aromatic tetracarboxylic acid compounds. And a random component of a copolymerized polyimide comprising: a copolymerized polyimide having a molecular bond, wherein 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride is used as an acid component. Is disclosed (see Example 11 of the document).
JP-A-9-328544 (release date: December 22, 1997) JP-A-9-235373 (Published date: September 9, 1997)

However, the polyimide film reported in Patent Literature 1 actually has (2) poor water-absorbing and moisture-absorbing properties even though (1) the thermal expansion property and (3) the elastic modulus are balanced. Has a problem. Specifically, the water absorption described in the examples of the above publication is in the range of 2.62 to 3.69%, and the coefficient of hygroscopic expansion is in the range of 16.8 to 29.8 ppm. It is getting bigger.

Patent Document 2 states that the obtained resin molded article has high elastic modulus, low thermal expansion, and low absorbency. Certainly, in Example 11 using 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, the elastic modulus was 4.3 GPa (440 kg / mm ² ) and the coefficient of linear expansion was 16.7 ppm / ° C. Although the water absorption is 2.4%, and although the physical properties of (1) to (3) are certainly improved, in order to use it for the production of the FPC by the above-mentioned TAB method, the following Comparative Example 8 is used. As shown, it is still not enough.

As described above, in the polyimide film obtained by using 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride as the acid component of the polyimide, the FPC (TAB tape or the like) by the TAB method has conventionally been used. It has been known that, when used, it is preferable to simultaneously realize various physical properties such as expansion by heat, water absorption / hygroscopicity, and elastic modulus. However, when evaluating the above physical properties, more specific parameters such as (1) a coefficient of linear expansion, (2) a coefficient of hygroscopic expansion, and (3) an elastic modulus are used, and these parameters are all set to values in a preferable range. Is not known, and it is very difficult to adjust all the numerical values of the parameters (1) to (3) so as to be within a preferable range.

The present invention has been made in view of the above problems, and has as its object to provide 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, particularly as a base film used for TAB tape or FPC. When a polyimide film obtained by using a product is used, (1) thermal expansion property, (2) water absorption / hygroscopicity, and (3) elastic modulus are sufficiently harmonized, and the occurrence of warpage and curling can be reduced. An object of the present invention is to provide a polyimide film that can be effectively avoided, a method for producing the same, and a typical example of its use.

In view of the above problems, the present inventor has conducted intensive studies. In particular, (2) using the coefficient of hygroscopic expansion to evaluate water absorption and hygroscopicity, (1) thermal expansion, (2) water absorption -It has been found that it is possible to obtain a polyimide film that can sufficiently balance the various physical properties such as hygroscopicity and (3) elastic modulus, and as a result, can more effectively avoid the occurrence of warpage and curling. Thus, the present invention has been completed. A polyimide film in which the physical properties of (1) to (3) are harmonized is used for a TAB tape as a typical example, but it can of course be suitably used for an FPC applied to various uses. It is.

That is, the polyimide film according to the present invention is a polyimide film obtained by using a polyamic acid synthesized mainly from an aromatic diamine and an aromatic tetracarboxylic dianhydride to solve the above problems, It has an average linear expansion coefficient at 100 to 200 ° C of 18 to 28 ppm, an elastic modulus of 4.5 GPa or more, a moisture absorption expansion coefficient of 13 ppm or less, and 3,3 ′, 4,4 ′ as an aromatic tetracarboxylic dianhydride. -Benzophenone tetracarboxylic dianhydride is used as an essential component.

In the polyimide film according to the present invention, when the wholly aromatic tetracarboxylic dianhydride component is 100 mol%, 3,3 ′, 4,4′-benzophenone tetracarboxylic dianhydride is 20 to 60 mol%. It is preferable to use it so that it may fall within the range.

Further, as the acid component used in the polyimide film according to the present invention, the following compounds are preferably used. That is, it is preferable to use an aromatic ester acid dianhydride as (I) the aromatic tetracarboxylic dianhydride component. Further, it is preferable to use the aromatic ester dianhydride in the range of 10 to 60 mol% when (II) the wholly aromatic tetracarboxylic dianhydride component is 100 mol%. Further, (III) p-phenylenebis (trimellitic acid monoester anhydride) is preferably used as the aromatic ester dianhydride.

ジ ア ミ ン As the diamine component used in the polyimide film according to the present invention, it is preferable to use at least one of a linear diamine and a flexible diamine. At this time, when the total aromatic diamine component is 100 mol%, it is preferable to use the linear diamine and the flexible diamine in the range of 20 to 80 mol% and in the range of 80 to 20 mol%, respectively. (II) As the linear diamine, p-phenylenediamine is preferably used. (III) Further, it is preferable to use 4,4'-oxydianiline as the flexible diamine.

に お い て In the polyimide film according to the present invention, it is preferable that the linear diamine and the flexible diamine are randomly distributed in the polyimide molecule.

The method for producing a polyimide film according to the present invention comprises at least a) a step of reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride in an organic solvent to obtain a polyamic acid solution; Casting the film-forming dope on the support, c) heating the film-forming dope on the support, and then peeling off the gel film from the support; and d) further heating the gel film to remain. And imidizing the amic acid, followed by drying, to produce the polyimide film.

に お い て In the method for producing a polyimide film according to the present invention, it is preferable to use at least a dehydrating agent and an imidization catalyst in combination.

As an example of the use of the polyimide film according to the present invention, a flexible printed wiring board having at least an FC tape in which an adhesive layer and a protective layer are provided on the polyimide film, a layer made of the polyimide film, and a metal conductive layer Can be mentioned.

As described above, the polyimide film according to the present invention has an average linear expansion coefficient at 100 to 200 ° C of 18 to 28 ppm, an elastic modulus of 4.5 GPa or more, a moisture absorption expansion coefficient of 13 ppm or less, and an aromatic tetracarboxylic acid dicarboxylic acid. As the anhydride, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride is used as an essential component.

Therefore, according to the above configuration, particularly when a polyimide film obtained by using 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride as an essential component is used as a base film used for a TAB tape or FPC. In addition, it is possible to provide a polyimide film which has both a linear expansion coefficient and an elastic modulus so as not to generate warpage or curl and also does not cause warpage or curl due to dimensional change due to moisture absorption.

An embodiment of the present invention will be described below. Note that the present invention is not limited to this. Hereinafter, the details of the present invention will be specifically described in the order of a polyimide film, a method for producing the same, its use (usefulness), and specific examples.
(1) Polyimide film according to the present invention <Physical properties of polyimide film>
The polyimide film according to the present invention is obtained by imidizing a polyamic acid synthesized mainly from an aromatic diamine and an aromatic tetracarboxylic dianhydride and using polyimide. Among them, the aromatic tetracarboxylic dianhydride contains at least 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, and the polyimide film thus obtained is It satisfies the following three conditions.
Condition (1): The average linear expansion coefficient at 100 ° C. to 200 ° C. is in the range of 18 to 28 ppm / ° C.
Condition (2): the elastic modulus is 4.5 GPa or more.
Condition (3): The coefficient of hygroscopic expansion is 13 ppm or less.

By satisfying the condition (1), the polyimide film prevents warpage and curling when used as an FPC or TAB tape. This makes it possible to provide a polyimide film having high flexibility and a linear expansion coefficient in a range where warpage or curling does not occur. In addition, a more preferable range of the average linear expansion coefficient at 100 ° C to 200 ° C of the polyimide film is in a range of 18 ppm to 25 ppm / ° C, and a further preferable range is in a range of 20 to 25 ppm / ° C.

(4) By satisfying the condition (2), the polyimide film can prevent dimensional changes in the reel-to-reel manufacturing process, and thus, warpage and curling of the FPC or TAB tape can be prevented. The more preferable range of the elastic modulus of the polyimide film is in a range of 4.5 GPa to 8.0 GPa, and the more preferable range is in a range of 5.0 GPa to 7.5 GPa.

Furthermore, when the polyimide film satisfies the condition (3), a dimensional change due to internal stress between the polyimide film and the copper foil due to moisture expansion is prevented. In addition, the more preferable range of the moisture absorption expansion coefficient of the said polyimide film is 12 ppm or less, and the still more preferable range is 11 ppm or less.

By satisfying the above three conditions, the polyimide film according to the present invention has both a thermal expansion property and an elastic modulus that do not generate warpage or curl, and can reduce water absorption and moisture absorption. It is possible to provide a polyimide film that does not cause warpage or curl due to dimensional change.

<Monomer component used for synthesis of polyimide>
The polyimide film according to the present invention mainly uses a polyimide obtained by imidizing a polyamic acid synthesized from an aromatic diamine and an aromatic tetracarboxylic dianhydride. That is, the polyimide used in the present invention can be obtained by polymerizing (synthesizing) the precursor polyamic acid and then imidizing the same.

Here, the “polyamic acid mainly synthesized from an aromatic diamine and an aromatic tetracarboxylic dianhydride” refers to a content ratio of an aromatic tetracarboxylic dianhydride in an acid component which is a raw material of the polyamic acid. Is the largest, and among the diamine components, the content ratio of the aromatic diamine is the largest.

In other words, in the present invention, the polymerization of the polyamic acid as the precursor includes an aromatic tetracarboxylic dianhydride as an acid component and an aromatic diamine as a diamine component, and these components are most frequently used. As long as it is used, other acid components and diamine components may be used.

Hereinafter, the acid component and the diamine component, which are the raw materials (monomer components) of the polyamic acid, will be specifically described.

<Acid component (acid dianhydride component)>
In the polyimide film according to the present invention, at least 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride is used as an acid component among the raw materials of polyamic acid which is a precursor of polyimide. This 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride is included in the category of the aromatic tetracarboxylic dianhydride.

When polyamic acid is polymerized, the specific amount (used amount) when the above 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride is used as an acid component is not particularly limited, When the total aromatic tetracarboxylic dianhydride component is 100 mol%, it is preferably used within a range of 20 to 60 mol%, more preferably within a range of 25 to 60 mol%, and more preferably 25 to 60 mol%. More preferably, it is 55 mol%. In other words, the upper limit of the amount of 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride used is preferably 60 mol% or less, more preferably 55 mol% or less. Further, the lower limit is preferably at least 20 mol%, more preferably at least 25 mol%.

When the amount of 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride is within this range, it is possible to suitably balance the coefficient of linear expansion and the elastic modulus, and the upper limit of this range. By the following, the coefficient of hygroscopic expansion can be reduced.

The aromatic tetracarboxylic dianhydride used in the present invention includes, in addition to the above 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride, an aromatic ester dianhydride Is preferably used. The term “aromatic ester dianhydride” used herein refers to an aromatic tetracarboxylic dianhydride containing an ester in the structure.

The aromatic ester dianhydride is not particularly limited, but specific examples include p-phenylene bis (trimellitic acid monoester anhydride) and ethylene bis (trimellitic acid monoester anhydride). Products), bisphenol A bis (trimellitic acid monoester acid anhydride) and the like.

The amount of the aromatic ester dianhydride to be used is not particularly limited, but is in the range of 10 to 60 mol% when the total aromatic tetracarboxylic dianhydride component is 100 mol%. Is more preferably in the range of 20 to 55 mol%, and still more preferably in the range of 25 to 50 mol%. In other words, the upper limit of the amount of the aromatic ester dianhydride used is preferably 60 mol% or less, more preferably 55 mol% or less, and more preferably 50 mol% or less. The lower limit is preferably at least 10 mol%, more preferably at least 20 mol%, further preferably at least 25 mol%.

(4) When the amount of the aromatic ester dianhydride used does not fall below this range, the effect of improving the elastic modulus and the coefficient of hygroscopic expansion is great, and when it does not exceed this range, a flexible film can be obtained.

In the present invention, among the above-mentioned aromatic ester dianhydrides, p-phenylene bis (trimellitic acid monoester anhydride) can be particularly preferably used. As a result, a polyimide suitable for improving mechanical strength, coefficient of hygroscopic expansion and thermal behavior can be obtained.

The amount of p-phenylenebis (trimellitic acid monoester anhydride) used is not particularly limited either, but is 10 to 60 mol% when the total aromatic tetracarboxylic dianhydride component is 100 mol%. It is preferably in the range, more preferably in the range of 20 to 55 mol%, and still more preferably in the range of 25 to 50 mol%. In other words, the upper limit of the amount of p-phenylenebis (trimellitic acid monoester anhydride) used is preferably 60 mol% or less, more preferably 55 mol% or less, and more preferably 50 mol% or less. The lower limit is preferably at least 10 mol%, more preferably at least 20 mol%, further preferably at least 25 mol%.

Further, the aromatic tetracarboxylic dianhydride used in the present invention includes the 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride or the 3,3 ′, 4,4 ′ -In addition to benzophenone tetracarboxylic dianhydride and the above-mentioned aromatic ester dianhydride, another aromatic tetracarboxylic dianhydride may be used. The term "another aromatic tetracarboxylic dianhydride" used herein refers to an aromatic that does not correspond to the above 3,3 ', 4,4'-benzophenonetetracarboxylic dianhydride or the aromatic ester dianhydride. It refers to tetracarboxylic dianhydride.

The other aromatic tetracarboxylic dianhydrides are not particularly limited, but specific examples include pyromellitic dianhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride. 3,3 ', 4,4'-biphenyltetracarboxylic dianhydride, 1,2,5,6-naphthalenetetracarboxylic dianhydride, 2,2', 3,3'-biphenyltetracarboxylic acid Dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, bis (3,4-dicarboxyphenyl) propane Dianhydride, 1,1-bis (2,3-dicarboxyphenyl) ethane dianhydride, 1,1-bis (3,4-dicarboxyphenyl) ethane dianhydride, bis (2,3-dicarboxy) Phenyl) methane Anhydride, bis (3,4-dicarboxyphenyl) ethane dianhydride, oxydiphthalic dianhydride, bis (3,4-dicarboxyphenyl) sulfone dianhydride, ethylenebis (trimellitic acid monoester anhydride) ), Bisphenol A bis (trimellitic acid monoester anhydride) and the like. These may be used alone or in combination of two or more.

の う ち Among the other aromatic tetracarboxylic dianhydrides, pyromellitic dianhydride and 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride are more preferably used.

The amount of the other aromatic tetracarboxylic dianhydride used is not particularly limited, but may be 50 mol% or less when the total aromatic tetracarboxylic dianhydride component is 100 mol%. Preferably, it is 45 mol% or less, more preferably, 40 mol% or less. In other words, the upper limit of the amount of the other aromatic tetracarboxylic dianhydride to be used is preferably 50 mol% or less, more preferably 45 mol% or less, and more preferably 40 mol% or less. The lower limit is not particularly limited, and may be 0 mol% or more.

When the amount of the other aromatic tetracarboxylic dianhydride used is within the above range, 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride and / or aromatic ester dianhydride are used. Can improve the effect of modifying the polyimide film.

In the present invention, an acid dianhydride other than the aromatic tetracarboxylic dianhydride (another acid dianhydride) is used as the acid component according to the physical properties required for the obtained polyimide film. May be. The amount of the other acid dianhydride used is not particularly limited.

<Diamine component>
In the polyimide film according to the present invention, at least an aromatic diamine is used as a diamine component in a raw material of polyamic acid which is a precursor of polyimide.

Specific examples of the aromatic diamine include p-phenylenediamine and its nucleus-substituted compound, benzidine and its nucleus-substituted compound, 4,4′-oxydianiline, 1,3-bis (4-aminophenoxy) ) Benzene, 1,3-bis (3-aminophenoxy) benzene, 4,4′-bis (3-aminophenoxy) biphenyl, 4,4′-bis (4-aminophenoxy) biphenyl, bis (4- (4 -Aminophenoxy) phenyl) sulfone, bis (4- (3-aminophenoxy) phenyl) sulfone, 4,4′-diaminodiphenylpropane, 4,4′-diaminodiphenylmethane, 4,4′-diaminodiphenylsulfide, 3, 3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3'-oxydi Niline, 3,4'-oxydianiline, 2,4'-oxydianiline, 4,4'-diaminodiphenyldiethylsilane, 4,4'-diaminodiphenylsilane, 4,4'-diaminodiphenylethylphosphine oxide, 4,4'-diaminodiphenyl N-methylamine, 4,4'-diaminodiphenyl @ N-phenylamine, 1,3-diaminobenzene, 1,2-diaminobenzene, and the like can be mentioned, but particularly limited ones are included. is not.

In the present invention, the aromatic diamine component preferably contains at least one of a linear diamine and a flexible diamine.

Here, the term “linear diamine” means that the main chain does not include a bending group such as an ether group, a methylene group, a propargyl group, a hexafluoropropargyl group, a carbonyl group, a sulfone group, and a sulfide group. A diamine compound having a structure in which the nitrogen atom of each amino group and the carbon atom to which they are bonded are aligned.

具体 Specific examples of the linear diamine include p-phenylenediamine and its nucleus-substituted compound, benzidine and its nucleus-substituted compound, but are not particularly limited thereto. The linear diamine may be used alone or in combination of two or more. Among these, it is more preferable to use p-phenylenediamine. This makes it possible to obtain a polyimide film that is excellent in terms of processability, handleability, and characteristics.

Further, the "flexible diamine" refers to a diamine containing a bending group such as an ether group, a methylene group, a propargyl group, a hexafluoropropargyl group, a carbonyl group, a sulfone group, and a sulfide group in a main chain, or a bending group. Does not include a diamine compound having a structure in which a nitrogen atom of two amino groups and a carbon atom bonded thereto are not aligned.

Specific examples of the flexible diamine include 4,4′-oxydianiline, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) benzene, and 4,4′-oxydianiline. '-Bis (3-aminophenoxy) biphenyl, 4,4'-bis (4-aminophenoxy) biphenyl, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (3-aminophenoxy) phenyl ) Sulfone, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylsulfide, 3,3'-diaminodiphenylsulfone, 4,4'-diaminodiphenylsulfone, 3,3 '-Oxydianiline, 3,4'-oxydianiline, 2,4'-oxydianiline, 4,4'-diaminodiif Nyldiethylsilane, 4,4′-diaminodiphenylsilane, 4,4′-diaminodiphenylethylphosphine oxide, 4,4′-diaminodiphenyl N-methylamine, 4,4′-diaminodiphenyl @ N-phenylamine, Examples thereof include 3-diaminobenzene and 1,2-diaminobenzene, but are not particularly limited. Only one kind of the flexible diamine may be used, or two or more kinds thereof may be used in appropriate combination. Among these, it is preferable to use 4,4'-oxydianiline. Thereby, a polyimide film excellent in harmony of various physical properties can be obtained.

The amount of the linear diamine and the flexible diamine among the aromatic diamines is not particularly limited, but when the total aromatic diamine component is 100 mol%, the linear diamine is in the range of 20 to 80 mol%. Is preferably used in the range of 30 to 70 mol%, more preferably in the range of 35 to 65 mol%.

Similarly, when the total aromatic diamine component is 100 mol%, the flexible diamine is preferably used in a range of 20 to 80 mol%, more preferably in a range of 30 to 70 mol%, More preferably, it is used in the range of 35 to 65 mol%.

In other words, the upper limit of the amount of each of the linear diamine and the flexible diamine is preferably 80 mol% or less, more preferably 70 mol% or less, and more preferably 65 mol% or less. In addition, the lower limit is preferably 20 mol% or more, more preferably 30 mol% or more, and further preferably 35 mol% or more. When the amounts of the linear diamine and the flexible diamine are compared, when the total aromatic diamine component is 100 mol%, the diamine is used in the range of 20 to 80 mol% and the range of 80 to 20 mol%, respectively. It is preferably used in the range of 30 to 70 mol% and more preferably in the range of 70 to 30 mol%, and still more preferably used in the range of 35 to 65 mol% and 65 to 35 mol%. .

When the usage amount of the linear diamine and the usage amount of the flexible diamine are within the above ranges, harmony between the elastic modulus and the coefficient of linear expansion is maintained, and the warpage characteristics of the flexible copper-clad laminate or the TAB tape can be improved. It will be easier.

分布 The distribution of the linear diamine and the flexible diamine in the polyimide molecule (polyamic acid molecule) is not particularly limited, but is preferably randomly distributed. This makes it easy to achieve both a high elastic modulus and a large coefficient of linear expansion.

In the present invention, a diamine other than an aromatic diamine (other diamine) may be used as the diamine component according to the physical properties required for the obtained polyimide film. The use amount of the other diamines is not particularly limited.

(2) Method for Producing Polyimide Film According to the Present Invention A method for producing a polyimide film according to the present invention will be described below.

重合 The method of polymerizing (synthesizing) the above polyamic acid is not particularly limited, and a conventionally known method can be used. An acid solution and a diamine component are dissolved in an organic solvent so as to be substantially equimolar (substantially equimolar amount) in the organic solvent and reacted, and a polyamic acid solution of a polyamic acid, which is a precursor of polyimide, is dissolved in the organic solvent. (Hereinafter, referred to as a polyamic acid solution).

The conditions for the reaction are not particularly limited, but the reaction temperature is preferably in the range of −20 ° C. to 90 ° C., and the reaction time is preferably in the range of about 30 minutes to 24 hours. Further, the atmosphere during the reaction is more preferably an inert atmosphere such as argon or nitrogen.

重合 In the polymerization of the polyamic acid, a plurality of types of polymerization methods can be used due to the difference in the method of reacting the acid component and the diamine component. Specifically, for example, the following polymerization methods 1) to 5) can be suitably used.

{Circle around (1)} A method in which an aromatic diamine is dissolved in an organic solvent, and the aromatic diamine is reacted with substantially equimolar aromatic tetracarboxylic dianhydride to carry out polymerization.

2) An aromatic tetracarboxylic dianhydride is reacted with an excessively small amount of an aromatic diamine compound in an organic solvent to obtain a prepolymer having acid anhydride groups at both terminals. Subsequently, a method of polymerizing using an aromatic diamine compound so that the aromatic tetracarboxylic dianhydride and the aromatic diamine compound are substantially equimolar in all steps.

(3) An aromatic tetracarboxylic dianhydride is reacted with an excess molar amount of an aromatic diamine compound in an organic solvent to obtain a prepolymer having amino groups at both ends. Subsequently, after the aromatic diamine compound is additionally added, an aromatic tetracarboxylic dianhydride and an aromatic diamine compound are used in substantially all equimolar amounts in all the steps using the aromatic tetracarboxylic dianhydride. How to polymerize.

# 4) A method of dissolving and / or dispersing an aromatic tetracarboxylic dianhydride in an organic solvent and then polymerizing the same using an aromatic diamine compound so as to be substantially equimolar.

# 5) A method in which a mixture of substantially equimolar aromatic tetracarboxylic dianhydride and aromatic diamine is reacted in an organic solvent to carry out polymerization.

The organic solvent used for preparing the polyamic acid solution, that is, the polymerization solvent used for the polymerization of the polyamic acid is not particularly limited as long as it is a solvent that dissolves the polyamic acid. Specific examples include amide solvents, that is, N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-2-pyrrolidone, etc. Among them, N, N-dimethylformamide , N, N-dimethylacetamide can be more preferably used. These organic solvents are usually used alone, but may be used in combination of two or more as necessary.

The composition of the polyamic acid solution is not particularly limited, but the polyamic acid is preferably dissolved in the organic solvent within a range of 5 to 35% by weight, and is preferably 10 to 30% by weight. Is more preferable. When the content is within such a range, it becomes possible to obtain an appropriate molecular weight and solution viscosity.

フ ィ ラ ー A filler may be added to the polyimide film for the purpose of improving various properties of the film such as slidability, thermal conductivity, conductivity, and corona resistance. The filler is not particularly limited, but preferred specific 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 may vary depending on the film characteristics to be modified and the type of filler to be added, and is not particularly limited, but generally has an average particle size of 0.05 to 100 μm. Is preferably in the range of 0.1 to 75 μm, more preferably in the range of 0.1 to 50 μm, and more preferably in the range of 0.1 to 25 μm. Is particularly preferred. If the particle size is within this range, the modifying effect is likely to appear in the polyimide film, and if it does not exceed this range, good surface properties and mechanical properties can be obtained in the polyimide film.

Also, the number of the added parts of the filler may vary depending on the film properties to be modified, the filler particle diameter, and the like, and is not particularly limited. In general, the amount of the filler is preferably in the range of 0.01 to 100 parts by weight, more preferably in the range of 0.01 to 90 parts by weight, based on 100 parts by weight of the polyimide. More preferably, it is in the range of 0.02 to 80 parts by weight. If the amount of the filler is not less than this range, the modifying effect by the filler is likely to be exhibited, and if it is not more than this range, good mechanical properties of the polyimide film can be maintained.

The method of adding the filler is not particularly limited, and specifically, for example, a method of adding the filler to the polymerization reaction solution before or during the polymerization, or a method of adding the filler using a three-roll after completion of the polymerization of the polyamic acid. And a method in which a dispersion containing a filler is prepared and mixed with a polyamic acid solution.

Above all, it is preferable to use a method in which a dispersion liquid containing a filler is prepared and mixed with a polyamic acid solution, particularly, a method in which the dispersion liquid is mixed immediately before film formation. Thereby, contamination of the production line by the filler can be minimized. When preparing a dispersion containing the filler, it is preferable to use the same solvent as the polymerization solvent for the polyamic acid. In order to disperse the filler well and to stabilize the dispersion state, a dispersant, a thickener and the like may be used within a range that does not affect the physical properties of the film.

In the present invention, the method for producing a polyimide film from the polyamic acid solution is not particularly limited, and a conventionally known method can be used. Examples of the imidation method include a thermal imidization method and a chemical imidization method, and it is more preferable to use the chemical imidization method. Thereby, a polyimide film excellent in thermal dimensional stability and mechanical strength can be obtained.

Next, a preferred example of the method for producing a polyimide film according to the present invention will be described, but the production method of the present invention is not limited thereto. The method for producing a polyimide film according to the present invention comprises a) a step of reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride in an organic solvent to obtain a polyamic acid solution; Casting the membrane dope on the support, c) heating the membrane dope on the support and then peeling off the gel film from the support, d) further heating the gel film to remove the remaining amide It is preferable to include at least four steps of imidizing and drying the acid.

に お い て In the above production method, a curing agent containing a dehydrating agent and preferably an imidization catalyst may be used in combination.

と り Taking a preferred embodiment of the present invention as an example, a process for producing a polyimide film by a chemical imidization method using a curing agent will be described.

In the chemical imidation method, a polyamic acid solution is mixed with a dehydrating agent represented by an acid anhydride such as acetic anhydride and an imidation catalyst represented by a tertiary amine such as isoquinoline, β-picoline and pyridine. This is a method of acting in any of the steps.

熱 The thermal imidation method may be used in combination with the chemical imidization method. Heating conditions can vary depending on the type of polyamic acid, film thickness, and the like.

a) reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride in an organic solvent to obtain a polyamic acid solution;
b) Casting a film-forming dope obtained by mixing a dehydrating agent and an imidization catalyst in a polyamic acid solution at a low temperature in a film shape on a support such as a glass plate, an aluminum foil, an endless stainless belt, or a stainless steel drum;
c) Partially cured and / or dried by activating the dehydrating agent and imidation catalyst by heating on a support in a temperature range of 80 ° C to 200 ° C, preferably 100 ° C to 180 ° C. It is peeled from the body to obtain a polyamic acid film (hereinafter, referred to as a gel film).

The gel film is in the middle stage of curing from polyamic acid to polyimide, has self-supporting properties, and has the formula 1
(AB) × 100 / B ··· Equation 1
In Formula 1, A and B represent the following.
A: Weight of gel film B: Volatile content calculated from weight after heating gel film at 450 ° C. for 20 minutes is in the range of 5 to 500%, preferably 5 to 100%, more preferably 10 to 80%. , Most preferably in the range of 30-60%.

フ ィ ル ム It is preferable to use a film in this range, and if it is removed, the mechanical strength may be reduced.

d) fixing the edge of the gel film to avoid shrinkage during curing, drying, removing water, residual solvent, residual additives and catalyst, and completely imidizing the remaining amic acid, The polyimide film of the invention is obtained.

At this time, it is preferable to finally heat at a temperature of 400 to 580 ° C. for 5 to 400 seconds. If the temperature is higher than this temperature and / or the time is longer, thermal deterioration of the film occurs and a problem occurs. Conversely, if the temperature is lower than this temperature and / or the time is short, the predetermined effect may not be exhibited.

Although the thickness of the obtained polyimide film is not particularly limited, in particular, when used as a base film of a TAB tape or FPC, the thickness of the film is preferably in the range of 10 to 125 μm, preferably 20 to 100 μm. Is more preferably in the range of 25 to 90 μm, and particularly preferably in the range of 40 to 80 μm.

As described above, the thus obtained polyimide film according to the present invention has an average linear expansion coefficient at 100 ° C. to 200 ° C. in the range of 18 to 28 ppm / ° C. and an elastic modulus of 4.5 GPa or more, This satisfies the condition that the coefficient of hygroscopic expansion is 13 ppm or less.

(3) Use of the present invention (usefulness of the present invention)
The polyimide film according to the present invention can be used for various applications depending on its physical properties, and can be particularly suitably used for FC (film carrier) tape used for FPC, TAB tape and the like. The FC tape according to the present invention refers to a tape having a three-layer structure in which an adhesive layer is provided on the polyimide film according to the present invention, and a protective layer is provided on the adhesive layer. Examples of the material of the adhesive layer include, but are not particularly limited to, epoxy resins, nylon-modified epoxy resins, acrylic resins, polyimide resins, phenol resins, phenol-modified epoxy resins, polyamideimide resins, and the like. It is not done. Examples of the material of the protective layer include PET and EVA, but are not particularly limited thereto.

Further, the FPC or TAB film according to the present invention is not particularly limited as long as a metal conductive layer is formed on at least one surface of the polyimide film according to the present invention with / without an adhesive layer. Not something. In other words, in the FPC or TAB tape according to the present invention, any structure having at least a layer made of the polyimide film and a metal conductive layer may be used, and an adhesive between the polyimide film layer and the metal conductive layer may be used. It may have an agent layer. Further, a metal conductive layer may be laminated on only one side of a layer (base film) made of a polyimide film, or a metal conductive layer may be laminated on both sides.

Therefore, in the present invention, a laminate having a two-layer structure of a polyimide film / metal conductive layer, a laminate having a three-layer structure of a metal conductive layer / polyimide film / metal conductive layer, a polyimide film / adhesive layer / metal conductive layer A laminate having a three-layer structure composed of layers, a laminate having a five-layer structure composed of a metal conductive layer / adhesive layer / polyimide film / adhesive layer / metal conductive layer, and the like are included.

Examples of the material of the adhesive layer include, for example, an epoxy resin, a nylon-modified epoxy resin, an acrylic resin, a polyimide resin, a phenol resin, a phenol-modified epoxy resin, a polyamideimide resin, and the like. It is not limited. The metal used for the metal conductive layer includes, for example, copper, but is not particularly limited thereto.

When an FPC or TAB tape is prepared by laminating a copper foil via an adhesive using the polyimide film according to the present invention, the adhesive is completely cured and is subjected to an environment of 23 ° C. and a relative humidity of 60%. After the humidity control for 100 hours, the amount of warpage is as follows, with the warpage having the adhesive surface inside as plus and the warpage with the adhesive surface outside as minus. When copper is not etched, the amount of warpage is preferably 0.5 mm or less, more preferably 0 mm or less, and particularly preferably -0.5 mm or less. When the copper foil is completely removed by etching, the amount of warpage is preferably 3.0 mm or less, more preferably 2.5 mm or less, and particularly preferably 2.0 mm or less. When the amount of warpage with the copper foil and the state where the copper foil is completely removed by etching simultaneously satisfies these ranges, it is possible to eliminate the problem caused by the warpage in the processing and mounting steps.

Hereinafter, the present invention will be described more specifically based on Examples and Comparative Examples, but the present invention is not limited thereto. In addition, the measurement of the elastic modulus of the polyimide film obtained by the Example or the comparative example was performed according to ASTM @ D882. The coefficient of linear expansion and the coefficient of hygroscopic expansion of the obtained polyimide film were measured as follows.

(Measurement of linear expansion coefficient)
The measurement of the average linear expansion coefficient from 100 ° C. to 200 ° C. was performed using TMA120C manufactured by Seiko Instruments Inc. The sample size was 3 mm in width and 10 mm in length. After applying a load of 3 g, the temperature was once increased from 10 ° C. to 400 ° C. at 10 ° C./min, and then cooled to 10 ° C. The temperature was further increased at 10 ° C./min, and the average value was calculated from the thermal expansion coefficients at 100 ° C. and 200 ° C. at the time of the second temperature increase.

(Measurement of coefficient of hygroscopic expansion)
The film to be measured was left in an environmental tester at 50 ° C. and a relative humidity of 30% for 24 hours, and the film size (L1) was measured. Next, the film was allowed to stand in an environmental tester at 50 ° C. and a relative humidity of 80% for 24 hours, the film size (L2) was measured, and the coefficient of hygroscopic expansion was calculated by the following equation.

Hygroscopic expansion coefficient (ppm) = (L1-L2) {L1} (80-30) × 10 ⁶
Also, a TAB tape was prepared from the obtained polyimide film as follows, and the warpage was measured.

[Production of TAB tape]
50 parts by weight of a polyamide resin (Platabond M1276 manufactured by Nippon Rilsan Co., Ltd.), 30 parts by weight of a bisphenol A type epoxy resin (Epicoat 828 manufactured by Yuka Shell Epoxy), 10 parts by weight of a cresol novolac type epoxy resin, and toluene / isopropyl alcohol 1/1 mixed An adhesive solution was prepared by mixing 150 parts by weight of the solution with 45 parts by weight of a diaminodiphenyl sulfone / dicyandiamide 4/1 20% methyl cellosolve solution.

The above-mentioned adhesive was applied on a PET film having a thickness of 25 μm to a thickness of 11 μm after drying, and dried at 120 ° C. for 2 minutes. The obtained PET film with the B-stage adhesive was slit to a width of 26 mm.

The PET film with the B-stage adhesive was bonded to the center of a 35 mm-wide polyimide film, and pressed at 90 ° C. under a pressure of 1 kg / cm ² . A PET film was peeled off, and a copper foil (manufactured by Mitsui Kinzoku Co., Ltd., VLP 18 μm thickness) was adhered to the surface of the polyimide film from which the PET film was peeled off by a roll lamination method (an TAB tape without etching). The bonding temperature is 120 ° C. and the pressure is 2 kg / cm ² .

The copper-clad product is heated at 60 ° C. for 3 hours, at 80 ° C. for 3 hours, at 120 ° C. for 3 hours, at 140 ° C. for 3 hours, and at 160 ° C. for 4 hours, and then gradually cooled to cure the adhesive. went. The obtained tape was designated as "tape with copper".

(4) After the adhesive was cured, the copper foil was completely removed by etching. The obtained tape was designated as "copper full etching tape".

[Measurement of warpage]
The value of the amount of warpage was measured by cutting out the TAB tape prepared in the above procedure into a length of 40 mm and a width of 35 mm. The test piece was allowed to stand in a room at a relative humidity of 60% and a temperature of 23 ° C. for 72 hours, then allowed to stand on a flat surface, and the lifted heights of four corners were measured. The value of the amount of warpage was indicated by an average value of data at four points.

[Example 1]
21.98 g of 4,4′-oxydianiline (ODA) and 7.91 g of p-phenylenediamine (PDA) were dissolved in 407.5 g of N, N-dimethylformamide (DMF), and the solution was dissolved in 0. C. Here, 29.47 g of 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride (BTDA) was gradually added, and the mixture was stirred for 1 hour to completely dissolve BTDA. To this solution, 25.15 g of p-phenylenebis (trimellitic acid monoester anhydride) (TMHQ) was gradually added, and the mixture was stirred for 1 hour. Then, 7.98 g of pyromellitic dianhydride (PMDA) was further added. After stirring for 1 hour, a polyamic acid solution having a solution viscosity of 3000 poise at 23 ° C. and a solid concentration of 18.5 wt% was obtained. Table 1 shows mol% of the monomer components added at this time. In Table 1 and Table 3 described later, the monomer composition is described from the top to the bottom in the order in which the monomers were added.

硬化 To 100 g of this polyamic acid solution, a curing agent consisting of 11.4 g of acetic anhydride, 4.8 g of isoquinoline and 33.8 g of DMF was mixed and stirred. The resulting solution was defoamed by centrifugation, and then cast on an aluminum foil. The process from stirring to defoaming was performed while cooling to 0 ° C. The laminate of the obtained aluminum foil and the polyamic acid solution was heated at 90 ° C. for 600 seconds to obtain a self-supporting gel film. This gel film was peeled off from the aluminum foil and fixed to a frame. The gel film was heated at 120 ° C., 250 ° C., 350 ° C., and 450 ° C. for 180 seconds, respectively, and then heat-treated in a 400 ° C. far-infrared oven for another 180 seconds. Using the thus obtained polyimide film having a thickness of 50 μm, a TAB tape was prepared according to the above method.

(4) The modulus of elasticity, the average coefficient of linear expansion, the coefficient of hygroscopic expansion, and the amount of warpage of the TAB tape of the obtained polyimide film were measured for the “tape with copper” and “copper fully etched tape”. Table 2 shows the measurement results.

[Example 2]
17.90 g of ODA and 9.67 g of PDA were dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. Here, 28.81 g of BTDA was gradually added and stirred for 1 hour to completely dissolve BTDA. 24.59 g of TMHQ was gradually added to this solution, and the mixture was stirred for 1 hour. Further, 11.52 g of BTDA was added, and the mixture was stirred for 1 hour. The polyamic acid solution had a solution viscosity of 2800 poise at 23 ° C. and a solid concentration of 18.5 wt%. Got. Table 1 shows mol% of the monomer components added at this time. Further, the fact that the mol% of BTDA is 50 or 20 in Table 1 indicates the amount of BPDA added first and the amount of BPDA added later.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 2 shows the properties of the polyimide film and the TAB tape.

[Example 3]
17.90 g of ODA and 9.67 g of PDA were dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. Here, 38.61 g of BTDA was gradually added and stirred for 1 hour to completely dissolve BTDA. 24.59 g of TMHQ was gradually added to this solution, and the mixture was stirred for 1 hour. Then, 1.73 g of BTDA was further added and stirred for 1 hour, and the polyamic acid solution having a solution viscosity of 310,000 poise at 23 ° C. and a solid concentration of 18.5 wt% was added. Got. Table 1 shows mol% of the monomer components added at this time. Further, the fact that the mol% of BTDA is 50 or 20 in Table 1 indicates the amount of BPDA added first and the amount of BPDA added later.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 2 shows the properties of the polyimide film and the TAB tape.

[Example 4]
19.86 g of ODA and 8.77 g of PDA were dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. Here, 29.04 g of BTDA was gradually added and stirred for 1 hour to completely dissolve BTDA. After slowly adding 28.92 g of TMHQ to this solution and stirring for 1 hour, further adding 5.90 g of PMDA and stirring for 1 hour, a polyamic acid solution having a solution viscosity of 2900 poise at 23 ° C. and a solid concentration of 18.5 wt%. Got. Table 1 shows mol% of the monomer components added at this time.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 2 shows the properties of the polyimide film and the TAB tape.

[Example 5]
18.66 g of ODA and 10.07 g of PDA were dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. Here, 30.02 g of BTDA was gradually added, and the mixture was stirred for 1 hour to completely dissolve BTDA. 25.62 g of TMHQ was gradually added to this solution, and the mixture was stirred for 1 hour. Then, 8.13 g of PMDA was further added and stirred for 1 hour, and the polyamic acid solution having a solution viscosity of 3200 poise at 23 ° C. and a solid concentration of 18.5 wt% was added. Got. Table 1 shows mol% of the monomer components added at this time.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 2 shows the properties of the polyimide film and the TAB tape.

[Example 6]
22.92 g of ODA and 8.25 g of PDA were dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. Here, 18.44 g of BTDA was gradually added and stirred for 1 hour to completely dissolve BTDA. To this solution, 26.23 g of TMHQ was gradually added, and the mixture was stirred for 1 hour. Then, 16.65 g of PMDA was further added, and the mixture was stirred for 1 hour. The polyamic acid solution having a solution viscosity of 3000 poise at 23 ° C. and a solid concentration of 18.5 wt% was added. Got. Table 1 shows mol% of the monomer components added at this time.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 2 shows the properties of the polyimide film and the TAB tape.

[Example 7]
25.13 g of ODA and 7.31 g of PDA were dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. To this, 12.44 g of BTDA was gradually added and stirred for 1 hour to completely dissolve BTDA. 26.55 g of TMHQ was gradually added to this solution, and the mixture was stirred for 1 hour. Further, 21.06 g of PMDA was added, and the mixture was stirred for 1 hour. The polyamic acid solution having a solution viscosity of 3000 poise at 23 ° C. and a solid concentration of 18.5 wt% was added. Got. Table 1 shows mol% of the monomer components added at this time.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 2 shows the properties of the polyimide film and the TAB tape.

Example 8
18.86 g of ODA and 10.19 g of PDA were dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. Here, 11.09 g of 3,3 ′, 4,4′-biphenyltetracarboxylic dianhydride (BPDA) was gradually added, and the mixture was stirred for 1 hour to completely dissolve BPDA. To this solution, 18.22 g of BTDA was gradually added, and the mixture was stirred for 1 hour. 25.91 g of TMHQ was added, followed by stirring for 1 hour. Further, 8.22 g of PMDA was added, the solution had a viscosity of 2700 poise at 23 ° C. and a solid concentration of 18.5 wt. % Polyamic acid solution was obtained. Table 1 shows mol% of the monomer components added at this time.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 2 shows the properties of the polyimide film and the TAB tape.

[Comparative Example 1]
21.48 g of ODA and 11.06 g of PDA were dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. To this, 31.56 g of BPDA was gradually added and stirred for 2 hours to completely dissolve BPDA. 14.04 g of PMDA was gradually added to this solution, and the mixture was stirred for 1 hour. Then, 13.83 g of BTDA was further added and stirred for 1 hour, and the polyamic acid solution having a solution viscosity of 2800 poise at 23 ° C. and a solid concentration of 18.5 wt% was added. Got. Table 3 shows mol% of the monomer components added at this time.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 4 shows the characteristics of the polyimide film and the TAB tape.

[Comparative Example 2]
19.20 g of ODA and 10.37 g of PDA were dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. To this, 28.21 g of BPDA was gradually added and stirred for 2 hours to completely dissolve BPDA. To this solution was gradually added 26.36 g of TMHQ and stirred for 1 hour. Then, 8.36 g of PMDA was further added and stirred for 1 hour. The polyamic acid solution having a solution viscosity of 2800 poise at 23 ° C. and a solid concentration of 18.5 wt% was added. Got. Table 3 shows mol% of the monomer components added at this time.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 4 shows the characteristics of the polyimide film and the TAB tape.

[Comparative Example 3]
19.92 g of ODA was dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. To this, 16.49 g of PMDA was gradually added and stirred for 1 hour to completely dissolve PMDA. After dissolving 10.76 g of PDA in this solution, 17.57 g of BPDA was gradually added and stirred for 2 hours to completely dissolve BPDA. Further, 26.45 g of TMHQ was gradually added and stirred for 1 hour. Further, 1.30 g of PMDA was added and stirred for 1 hour to obtain a polyamic acid solution having a solution viscosity of 3100 poise at 23 ° C. and a solid concentration of 18.5 wt%. Was. Table 3 shows mol% of the monomer components added at this time. Further, the fact that the mol% of PMDA is 50 or 20 in Table 3 indicates the amount of PMDA added first and the amount of BPDA added later.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 4 shows the characteristics of the polyimide film and the TAB tape.

[Comparative Example 4]
30.21 g of ODA and 5.15 g of PDA were dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. Here, 26.39 g of TMHQ was gradually added, and the mixture was stirred for 1 hour. Then, 30.75 g of PMDA was added, and the mixture was stirred for 1 hour. The polyamic acid solution had a solution viscosity of 2900 poise at 23 ° C. and a solid concentration of 18.5 wt%. Got. Table 3 shows mol% of the monomer components added at this time.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 4 shows the characteristics of the polyimide film and the TAB tape.

[Comparative Example 5]
44.27 g of ODA was dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. Here, 48.23 g of PMDA was gradually added, and the mixture was stirred for 2 hours to completely dissolve PMDA to obtain a polyamic acid solution having a solution viscosity of 2800 poise at 23 ° C. and a solid concentration of 18.5 wt%. Table 3 shows mol% of the monomer components added at this time.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 4 shows the characteristics of the polyimide film and the TAB tape.

[Comparative Example 6]
24.87 g of ODA and 13.43 g of PDA were dissolved in 407.5 g of DMF, and the solution was kept at 0 ° C. Here, 54.19 g of PMDA was gradually added, and the mixture was stirred for 2 hours to completely dissolve PMDA to obtain a polyamic acid solution having a solution viscosity of 2900 poise at 23 ° C. and a solid content concentration of 18.5 wt%. Table 3 shows mol% of the monomer components added at this time.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 4 shows the characteristics of the polyimide film and the TAB tape.

[Comparative Example 7]
26.19 g of ODA and 14.14 g of PDA were dissolved in 489 g of DMF, and the solution was kept at 0 ° C. Here, 42.14 g of BTDA was gradually added, and the mixture was stirred for 1 hour. Then, 28.53 g of PMDA was gradually added, and the mixture was stirred for 2 hours to completely dissolve PMDA. A polyamic acid solution having a concentration of 18.5% by weight was obtained. Table 3 shows mol% of the monomer components added at this time.

５０A 50 μm-thick polyimide film and TAB tape were obtained in the same manner as in Example 1 except that this polyamic acid solution was used. Table 4 shows the characteristics of the polyimide film and the TAB tape.

[Comparative Example 8]
Polyamic acid was obtained with a monomer composition similar to that of Example 11 using 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride as an acid component as disclosed in Patent Document 2 described above. The addition weight of each monomer was 5.93 g of PPD; 11.64 g of PMDA; 32.97 g of ODA; 17.68 g of BTDA; and 24.28 g of PMDA.

５０A polyimide film having a thickness of 50 μm was obtained in the same manner as in Example 1 except that this polyamic acid solution was used, and the coefficient of hygroscopic expansion was measured. As a result, it was 18 ppm, which was a very large value. For this reason, the technique disclosed in Patent Literature 2 cannot reduce the coefficient of hygroscopic expansion.

　表２に示すように、実施例１〜８で製造され、評価されたポリイミドフィルムは、１００℃から２００℃における平均線膨張係数が１８ｐｐｍ／℃以上、２８ｐｐｍ／℃以下であり、弾性率が４．５ＧＰａ以上、吸湿膨張係数が１３ｐｐｍ以下であり、本発明にかかるポリイミドフィルムとして、優れた物性を示した。また、「銅付きテープ」における反り量は、全ての実施例で−０．５ｍｍ以下であり、「フルエッチテープ」における反り量も、全ての実施例で２．０ｍｍ以下であり、加工及び実装工程における反り由来の不具合点を解消できることが示された。

As shown in Table 2, the polyimide films produced and evaluated in Examples 1 to 8 had an average linear expansion coefficient at 100 ° C. to 200 ° C. of 18 ppm / ° C. or more and 28 ppm / ° C. or less, and an elastic modulus of 4 0.5 GPa or more, the coefficient of hygroscopic expansion was 13 ppm or less, and the polyimide film according to the present invention exhibited excellent physical properties. Also, the amount of warpage in the “tape with copper” is −0.5 mm or less in all examples, and the amount of warpage in the “full-etch tape” is 2.0 mm or less in all examples. It was shown that the problem caused by the warpage in the process can be eliminated.

　これに対して、表４に示すように、比較例１〜７で製造され、評価されたポリイミドフィルムは、１００℃から２００℃における平均線膨張係数、弾性率、吸湿膨張係数のいずれかが上記（１）〜（３）の条件を満たさず、本発明にかかるポリイミドフィルムに比べて明らかに物性が劣っていた。また、「銅付きテープ」における反り量は、比較例１、４、７で５ｍｍ以上であり、「フルエッチテープ」における反り量は、比較例６で３ｍｍ以上であり、本発明にかかるポリイミドフィルムに比べて物性が劣っていた。

On the other hand, as shown in Table 4, the polyimide films produced and evaluated in Comparative Examples 1 to 7 had an average linear expansion coefficient at 100 ° C. to 200 ° C., an elastic modulus, and a coefficient of hygroscopic expansion of the above. The conditions (1) to (3) were not satisfied, and the physical properties were clearly inferior to those of the polyimide film according to the present invention. The warp amount in the “copper tape” is 5 mm or more in Comparative Examples 1, 4, and 7, and the warp amount in the “full-etch tape” is 3 mm or more in Comparative Example 6, and the polyimide film according to the present invention. Physical properties were inferior to those of.

As described above, the polyimide film according to the present invention is a polyimide film obtained by using a polyamic acid synthesized mainly from an aromatic diamine and an aromatic tetracarboxylic dianhydride, It contains 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride as an anhydride, and has an average coefficient of linear expansion from 100 ° C. to 200 ° C. of 18 ppm / ° C. or more and 28 ppm / ° C. or less, and an elastic modulus. Is 4.5 GPa or more and the coefficient of hygroscopic expansion is 13 ppm or less.

Therefore, it is possible to provide a polyimide film having both a linear expansion coefficient and an elastic modulus so as not to generate warpage or curl, and also not to generate warp or curl due to dimensional change due to moisture absorption. Therefore, it is possible to prevent the occurrence of warpage or curl which causes a mounting failure in a process of processing into an FPC or TAB tape used in various electronic devices.

Therefore, the present invention is suitably used not only in the chemical industry and the resin industry for producing a polyimide film, but also in the electronic component industry using FPC and TAB tape and the like, and further, in the electric / electronic equipment industry using electronic components. be able to.

Claims (14)

A polyimide film obtained using a polyamic acid mainly synthesized from an aromatic diamine and an aromatic tetracarboxylic dianhydride,
An average linear expansion coefficient at 100 to 200 ° C. of 18 to 28 ppm, an elastic modulus of 4.5 GPa or more, and a moisture absorption expansion coefficient of 13 ppm or less,
A polyimide film comprising 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride as an essential component as an aromatic tetracarboxylic dianhydride. Using 3,3 ′, 4,4′-benzophenonetetracarboxylic dianhydride as a total aromatic tetracarboxylic dianhydride component of 100 mol% so as to be within a range of 20 to 60 mol%. The polyimide film according to claim 1, wherein: (3) The polyimide film according to (1) or (2), wherein an aromatic ester dianhydride is used as the aromatic tetracarboxylic dianhydride component. The aromatic ester dianhydride is used in a range of 10 to 60 mol% when the total aromatic tetracarboxylic dianhydride component is 100 mol%. Polyimide film. (5) The polyimide film according to (3) or (4), wherein p-phenylenebis (trimellitic acid monoester anhydride) is used as the aromatic ester dianhydride. The polyimide film according to any one of claims 1 to 5, wherein at least one of a linear diamine and a flexible diamine is used as the aromatic diamine component. When the total aromatic diamine component is 100 mol%, the linear diamine and the flexible diamine are used in the range of 20 to 80 mol% and in the range of 80 to 20 mol%, respectively. 3. The polyimide film according to item 1. The polyimide film according to claim 6, wherein p-phenylenediamine is used as the linear diamine. The polyimide film according to any one of claims 6 to 8, wherein 4,4'-oxydianiline is used as the flexible diamine. The polyimide film according to any one of claims 6 to 9, wherein the linear diamine and the flexible diamine are randomly distributed in the polyimide molecule. at least,
a) a step of reacting an aromatic diamine and an aromatic tetracarboxylic dianhydride in an organic solvent to obtain a polyamic acid solution;
b) casting a film-forming dope containing the polyamic acid solution on a support,
c) a step of heating the film-forming dope on a support and then peeling off the gel film from the support;
d) further heating the gel film to imidize the remaining amic acid and drying it;
The method for producing a polyimide film according to any one of claims 1 to 10, comprising: 12. The method for producing a polyimide film according to claim 11, wherein at least a dehydrating agent and an imidization catalyst are used in combination. (11) An FC tape, comprising an adhesive layer and a protective layer provided on the polyimide film according to any one of (1) to (10). A flexible printed wiring board comprising at least a layer made of the polyimide film according to any one of claims 1 to 10 and a metal conductive layer.