JP2022172834A - Polyimide resin, polyimide composition, cured film of polyimide composition and manufacturing method thereof, insulator film, protective film and electronic component - Google Patents

Abstract

To provide a polyimide resin capable of producing a cured film having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus and a low linear thermal expansion coefficient, while having a lower speed in remelting properties of a coating film, and also to provide a polyimide composition including the polyimide resin, a cured film of the polyimide composition and a manufacturing method thereof, an insulator film and a protective film using the cured film of the polyimide composition, and an electronic component including these.SOLUTION: A polyimide resin is obtained by polymerizing: (1) 2,2'-bis(trifluoromethyl) benzidine; (2) 3,3',4,4'-benzophenonetetracarboxylic acid dianhydride; (3) pyromellitic acid anhydride; and (4) a compound below.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a polyimide resin, a polyimide composition, a cured film of the polyimide composition and a method for producing the same, an insulating film, a protective film, and an electronic component.

In recent years, electronic devices have rapidly become smaller, thinner, and lighter, and along with this, semiconductor devices have also become highly integrated and miniaturized. Wafer level packaging (WLP), 2.5-dimensional integrated circuits (2.5D IC) using an interposer, and die obtained by thinning the wafer are examples of semiconductor devices that respond to such miniaturization and high integration. is being developed, such as a three-dimensional integrated circuit (3D IC) in which these are stacked and connected by a through-silicon via (TSV).

BACKGROUND ART Conventionally, polyimide resins, which have excellent heat resistance, electrical insulation and mechanical properties, have been used as insulating materials for electronic parts, passivation films, surface protective films, interlayer insulating films, etc. for semiconductor devices. A polyimide resin is a resin obtained by a dehydration ring closure reaction of a polyamic acid obtained by a condensation reaction of a tetracarboxylic dianhydride and a diamine.
However, conventional polyimides have the drawbacks of high curing temperature and large shrinkage after curing. If the shrinkage after curing is large, the cured film of polyimide has a large residual stress, which causes bending of a semiconductor substrate such as a silicon wafer. For example, next generation chip configurations used for 3D integrated circuits will require silicon wafers as thin as 20 μm in state-of-the-art applications to meet the requirements for vertical integration. This thin wafer is extremely fragile and excessive residual stress in the packaging materials used can be very detrimental. Therefore, low cure temperatures and low post-cure shrinkage are key requirements for packaging materials required for new semiconductor packaging technologies such as advanced wafer level packaging.

Patent Document 1 describes an indane skeleton as a polyimide that satisfies the requirements for packaging materials required for new semiconductor packaging technology, such as low-temperature curing, low coefficient of linear thermal expansion, and solubility in solvents that are friendly to the environment and semiconductors. A polyimide is disclosed using a diamine having a

On the other hand, Patent Document 2 discloses a tetracarboxylic acid obtained by reacting trimellitic anhydride chloride with 2,2′,3,3′5,5′-hexamethyl-biphenyl-4,4′-diol. A polyimide obtained by reacting a dianhydride with 2,2′-bis(trifluoromethyl)benzidine and a cured film of a polyimide composition using the polyimide are disclosed.

Japanese Patent No. 6467433 Japanese Patent No. 6165153

The polyimide of Patent Document 1 is described as a polyimide that satisfies requirements such as low-temperature curability, low coefficient of linear thermal expansion, and solubility in solvents that are friendly to the environment and semiconductors. However, the polyimide of Patent Document 1 has a coefficient of linear thermal expansion of 46 ppm/° C. or 47 ppm/° C., which is still a large difference from that of the semiconductor substrate. there is
In addition to low-temperature curability, low linear thermal expansion coefficient, solvent solubility, etc., the packaging materials required for new semiconductor packaging technology must also have low dielectric properties (low dielectric constant, low dielectric loss tangent, etc.) to reduce power consumption. ), and a high elastic modulus is further required to ensure the strength of the rewiring layer.

The polyimide of Patent Document 2 has excellent transparency, high heat resistance and a low coefficient of linear thermal expansion, and solvent processability with a low hygroscopic solvent (excellent It is described that it exhibits excellent solubility and film-forming properties). However, the polyimide described in Patent Document 2 has a problem that the re-dissolving rate of the coating film (dry film) is slow, as shown in the comparative example described later. In the production process, there is a demand for a polyimide composition having a fast re-dissolving speed, in which the solid content of the once-dried polyimide composition is easily dissolved again in the washing solvent. In general, lowering the molecular weight of the polyimide increases the resolubility of the coating film, but in that case, the mechanical properties (elastic modulus) decrease, and the resolubility speed and elasticity of the coating film decrease. The rate has a trade-off relationship.

The present invention has been made in view of the above problems, and is capable of forming a cured film having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low coefficient of linear thermal expansion, while regenerating the coating film. A polyimide resin having a high solubility rate, a polyimide composition containing the polyimide resin, a cured film of the polyimide composition and a method for producing the same, and an insulating film and a protective film using the cured film of the polyimide composition, including these The purpose is to provide electronic components.

In the present invention, the structural unit represented by the following formula (1) is 40 mol% or more and less than 70 mol% of all structural units, and the structural unit represented by the following formula (2) is more than 10 mol% of all structural units. Provided is a polyimide resin containing 60 mol % or less.

In the polyimide resin according to the present invention, a cured film having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low coefficient of linear thermal expansion can be formed, while the re-dissolving speed of the coating film is fast. From the point of view of resin, the weight average molecular weight by polystyrene conversion of gel permeation chromatography may be 150,000 or more.

In the polyimide resin according to the present invention, a cured film having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low coefficient of linear thermal expansion can be formed, while the re-dissolving speed of the coating film is fast. From the viewpoint of forming a resin, it may further contain a structural unit represented by the following formula (3) in an amount of 20 mol % or less of all structural units.

The present invention also provides a polyimide composition containing the polyimide resin according to the present invention and an organic solvent.

Further, the present invention, as one of the preferred embodiments of the polyimide composition, further, from the point of being able to form a cured film with excellent adhesion, the polyimide resin according to the present invention, three in one molecule A polyimide composition containing an epoxy compound having the above epoxy group and having a glycidylamine moiety and an organic solvent (hereinafter, the polyimide composition containing the epoxy compound is referred to as "polyimide composition of Embodiment A" (sometimes).

The polyimide composition of Embodiment A according to the present invention may further contain a compound represented by the following general formula (A) from the viewpoint of improving adhesion.

（式（Ａ）中、Ｒ^ａは、グリシジル基、（メタ）アクリロイル基、酸無水物基、ヒドロキシ基、トリアジン基、及びアミノ基からなる群から選択される少なくとも１種を含む１価の基を表し、Ｒ^ｂ及びＲ^ｃはそれぞれ独立に、炭素数１～５のアルキル基であり、ｎは１～１０の整数であり、ｍは１～３の整数である。）

(In the formula (A), R ^a is a monovalent group containing at least one selected from the group consisting of a glycidyl group, a (meth)acryloyl group, an acid anhydride group, a hydroxy group, a triazine group, and an amino group. and R ^b and R ^c are each independently an alkyl group having 1 to 5 carbon atoms, n is an integer of 1 to 10, and m is an integer of 1 to 3.)

Further, the present invention includes a step of applying the polyimide composition according to the present invention on a substrate and drying to form a coating film;
Provided is a method for producing a cured film of a polyimide composition, comprising the step of forming a cured film by heating the coating film.

In the method for producing a cured film of a polyimide composition according to the present invention, the temperature for heating the coating film may be 150° C. or higher and 240° C. or lower.

The present invention also provides a cured film of a polyimide composition obtained by curing the polyimide composition according to the present invention.

The cured film of the polyimide composition may have a dielectric constant of 3.60 or less and a dielectric loss tangent of 0.020 or less when measured at 10 GHz using a split cylinder resonator.
The cured film of the polyimide composition may have a coefficient of linear thermal expansion of 30 ppm/°C or less at 100°C to 150°C.
Further, the cured film of the polyimide composition may have a tensile modulus of 4.5 GPa or more at 25°C.

Further, the present invention is a cured film of the polyimide composition of Embodiment A according to the present invention, and the adhesion to the silicon nitride substrate is not peeled off by a cross-cut test method in accordance with JIS K 5400-8.5. Provided is a cured film of a polyimide composition in which the number of grids is 80% or more of the whole.

The present invention provides an insulating film produced using the cured film of the polyimide composition according to the present invention.
The present invention also provides a protective film produced using the cured film of the polyimide composition according to the present invention.
The present invention also provides an electronic component including the insulating film according to the present invention or the protective film according to the present invention.

According to the present invention, a polyimide resin capable of forming a cured film having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low coefficient of linear thermal expansion, and having a high rate of re-dissolution of the coating film, It is possible to provide a polyimide composition containing a polyimide resin, a cured film of the polyimide composition and a method for producing the same, an insulating film and a protective film using the cured film of the polyimide composition, and an electronic component including these.
In addition, according to the present invention, it is possible to form a cured film having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, a low coefficient of linear thermal expansion, and excellent adhesion, while resolving the coating film. It is possible to provide a polyimide composition having a high speed, a cured film of the polyimide composition, a method for producing the same, an insulating film and a protective film using the cured film of the polyimide composition, and an electronic part including these.

FIG. 1 is a manufacturing process diagram of a semiconductor device having a multilayer wiring structure, which is an electronic component according to one embodiment of the present invention.

Hereinafter, the polyimide resin, the polyimide composition, the cured film of the polyimide composition, the production method thereof, the insulating film, the protective film, and the electronic component according to the present invention will be described in detail.
In addition, the terms such as "parallel", "perpendicular", "same" and the like, length and angle values, etc. that specify shapes and geometric conditions and their degrees used in this specification are strictly It shall be interpreted to include the extent to which similar functions can be expected without being bound by the meaning.
In addition, in the drawings attached to this specification, for convenience of illustration and ease of understanding, the scale and the ratio of vertical and horizontal dimensions may be changed and exaggerated from those of the real thing.
Moreover, in this specification, (meth)acryl represents each of acrylic and methacryl, and (meth)acryloyl represents each of acryloyl and methacryloyl.
Further, in this specification, the term "to" indicating a numerical range is used to include the numerical values before and after it as lower and upper limits.

I. Polyimide resin The polyimide resin, which is one embodiment of the present invention, has a structural unit represented by the following formula (1) in 40 mol% or more and less than 70 mol% of all structural units, and a structure represented by the following formula (2) It is a polyimide resin containing more than 10 mol % and 60 mol % or less of all structural units.

The polyimide resin, which is one embodiment of the present invention, can form a cured film having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low linear thermal expansion coefficient, while the redissolution rate of the coating film is fast.
The structural unit of the formula (1) of the present invention is a tetracarboxylic acid residue having a specific structure containing a parabiphenylene group with a twisted dihedral angle via an ester bond in the main chain, and a trifluoromethyl group. It contains a diamine residue with a specific structure including a para-biphenylene group with twisted corners. Since the structural unit contains two parabiphenylene groups with twisted dihedral angles, the main chain structure is linear and rigid, so the polyimide resin having many structural units of the formula (1) has solvent solubility. Even with this, the rate of redissolution of the coating was slow.
In contrast, in the polyimide resin of the present invention, a specific amount of the structural unit of formula (1) and a specific amount of the structural unit of formula (2) are combined. Since the structural unit of formula (2) has a 3,3′,4,4′-benzophenonetetracarboxylic dianhydride residue, it can have a structure in which the main chain is largely bent. Therefore, when a specific amount of the structural unit of the formula (1) is combined with a specific amount of the structural unit of the formula (2), there is an effect of moderately weakening the intermolecular force in the polyimide resin, and a high elastic modulus can be achieved. Even the molecular weight is presumed to speed up the resolubility of the coating. In addition, since the bending direction of the 3,3',4,4'-benzophenonetetracarboxylic dianhydride residue is fixed by the carbonyl group, unlike the case where it is linked by a hexafluoropropane group, the polyimide resin It is presumed that it is difficult to reduce the mechanical properties of the material, and that it can be maintained or even improved.
In addition, the straight and rigid main chain structure containing a large number of parabiphenylene groups with twisted dihedral angles in the structural units contains an appropriate amount of bending component, so it has a low dielectric constant, a low dielectric loss tangent, and a high elastic modulus. , and a cured film with a low coefficient of linear thermal expansion.
Since the polyimide resin of the present invention has a high rate of re-dissolving of the coating film, the coating apparatus can be washed well during the manufacturing process, and the washing efficiency is improved, contributing to the improvement of the work efficiency. In addition, since it becomes possible to select a relatively safe cleaning solvent, it contributes to reducing the burden on workers.
Moreover, the polyimide resin of the present invention is a soluble polyimide resin and has a low curing temperature, and a curing temperature of 150° C. or more and 240° C. or less can be employed.

Hereinafter, the polyimide resin which is one embodiment of the present invention will be described in detail.
The tetracarboxylic acid residue refers to a residue obtained by removing four carboxyl groups from a tetracarboxylic acid, and has the same structure as a residue obtained by removing an acid dianhydride structure from a tetracarboxylic dianhydride, It may be a tetracarboxylic dianhydride residue.
A diamine residue refers to a residue obtained by removing two amino groups from a diamine.

In the polyimide resin which is one embodiment of the present invention, the structural unit represented by the formula (1) is a tetracarboxylic dianhydride represented by the following formula (1-1) and 2,2'-bis It can be obtained by reacting with (trifluoromethyl)benzidine.

In the polyimide resin which is one embodiment of the present invention, the structural unit represented by the formula (1) forms a cured film having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low coefficient of linear thermal expansion. Although it is possible, it is 40 mol % or more and less than 70 mol % of the total structural units in order to obtain a polyimide having a high re-dissolving rate of the coating film. The structural unit represented by the formula (1) may be 45 mol% or more, 50 mol% or more, or 55 mol% or more of the total structural units from the viewpoint of resolubility of the coating film. There may be. On the other hand, the structural unit represented by the above formula (1) may be 65 mol % or less, or 60 mol % or less, of the total structural units from the viewpoint of a low coefficient of linear thermal expansion.

Further, in the polyimide resin which is one embodiment of the present invention, the structural unit represented by the formula (2) is 3,3',4,4'-benzophenonetetracarboxylic dianhydride and 2,2'- It can be obtained by reacting with bis(trifluoromethyl)benzidine.
In the polyimide resin which is one embodiment of the present invention, the structural unit represented by the formula (2) forms a cured film having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low coefficient of linear thermal expansion. Although it is possible, it is more than 10 mol % and 60 mol % or less of all structural units from the viewpoint of obtaining a polyimide having a high re-dissolving speed of the coating film. The structural unit represented by the formula (2) may be 15 mol% or more, 20 mol% or more, or 30 mol% or more of the total structural units from the viewpoint of a low linear thermal expansion coefficient. may On the other hand, the structural unit represented by the formula (2) may be 55 mol% or less, or 50 mol% or less, of the total structural units from the viewpoint of resolubility of the coating film. It may be mol % or less.

In the polyimide resin which is one embodiment of the present invention, a cured film having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low coefficient of linear thermal expansion can be formed, while the resolubility of the coating film From the viewpoint of making a polyimide with a high speed, the total of the structural units represented by the formula (1) and the structural units represented by the formula (2) may be 75 mol% or more of all structural units. It may be mol % or more, and may be 85 mol % or more.

In the polyimide resin which is one embodiment of the present invention, the structural unit represented by the formula (1) and the structural unit represented by the formula (2) are included in the specific amount, and the effects of the present invention are impaired. Unless otherwise specified, other polyimide structural units different from the structural units represented by the formula (1) and the structural units represented by the formula (2) may be contained. The other polyimide structural unit is a polyimide that can form a cured film with a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low coefficient of linear thermal expansion, and has a fast re-dissolving speed of the coating film. In view of the above, it may be 25 mol % or less, 20 mol % or less, or 15 mol % or more of all structural units.

In order to form other polyimide structural units, combined with the tetracarboxylic dianhydride and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride represented by the formula (1-1), The tetracarboxylic dianhydride used as a copolymerization component includes at least one of a tetracarboxylic dianhydride having an aromatic ring and a tetracarboxylic dianhydride having an aliphatic ring.

Examples of the tetracarboxylic dianhydride having an aromatic ring include pyromellitic dianhydride, 2,2',3,3'-benzophenonetetracarboxylic dianhydride, 3,3',4,4' -biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, 2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, 2,2-bis (2,3-dicarboxyphenyl) propane dianhydride, bis (3,4-dicarboxyphenyl) ether dianhydride, bis ( 3,4-dicarboxyphenyl)sulfone dianhydride, 1,1-bis(2,3-dicarboxyphenyl)ethane dianhydride, bis(2,3-dicarboxyphenyl)methane dianhydride, bis(3 ,4-dicarboxyphenyl)methane dianhydride, 1,3-bis[(3,4-dicarboxy)benzoyl]benzene dianhydride, 1,4-bis[(3,4-dicarboxy)benzoyl]benzene dianhydride, 2,2-bis{4-[4-(1,2-dicarboxy)phenoxy]phenyl}propane dianhydride, 2,2-bis{4-[3-(1,2-dicarboxy ) phenoxy]phenyl}propane dianhydride, bis{4-[4-(1,2-dicarboxy)phenoxy]phenyl}ketone dianhydride, bis{4-[3-(1,2-dicarboxy)phenoxy ] phenyl} ketone dianhydride, 4,4′-bis[4-(1,2-dicarboxy)phenoxy]biphenyl dianhydride, 4,4′-bis[3-(1,2-dicarboxy)phenoxy ] biphenyl dianhydride, bis{4-[4-(1,2-dicarboxy)phenoxy]phenyl}ketone dianhydride, bis{4-[3-(1,2-dicarboxy)phenoxy]phenyl}ketone dianhydride, bis{4-[4-(1,2-dicarboxy)phenoxy]phenyl}sulfone dianhydride, bis{4-[3-(1,2-dicarboxy)phenoxy]phenyl}sulfone dianhydride bis{4-[4-(1,2-dicarboxy)phenoxy]phenyl}sulfide dianhydride, bis{4-[3-(1,2-dicarboxy)phenoxy]phenyl}sulfide dianhydride, 4,4′-(hexafluoroisopropylidene)diphthalic anhydride, 3,4′-(hexafluoroisopropylidene)diphthalic anhydride, 3,3′-(hexafluoroisopropylidene)diphthalic anhydride, 4, 4' -oxydiphthalic anhydride, 3,4'-oxydiphthalic anhydride, 2,3,6,7-naphthalenetetracarboxylic dianhydride, 1,4,5,8-naphthalenetetracarboxylic dianhydride, 1, 2,5,6-naphthalenetetracarboxylic dianhydride, 1,2,3,4-benzenetetracarboxylic dianhydride, 3,4,9,10-perylenetetracarboxylic dianhydride, 2,3 ,6,7-anthracenetetracarboxylic dianhydride, 1,2,7,8-phenanthrenetetracarboxylic dianhydride, and the like.
Examples of the tetracarboxylic dianhydride having an aliphatic ring include cyclohexanetetracarboxylic dianhydride, cyclopentanetetracarboxylic dianhydride, dicyclohexane-3,4,3′,4′-tetracarboxylic dianhydride, anhydride, cyclobutanetetracarboxylic dianhydride, bicyclo[2.2.2]oct-7-ene-2,3,5,6-tetracarboxylic dianhydride, 1,1′-bicyclohexane-3, 3',4,4'-tetracarboxylic dianhydride and the like.
These may be used alone or in combination of two or more.

As the tetracarboxylic dianhydride used as a copolymerization component to form other polyimide structural units, pyromellitic dianhydride, 3,3', 4,4'-biphenyltetracarboxylic dianhydride, 2,2',3,3'-biphenyltetracarboxylic dianhydride, 2,3,3',4'-biphenyltetracarboxylic dianhydride, and At least one kind of cyclobutanetetracarboxylic dianhydride is preferably used, and pyromellitic dianhydride is particularly preferably used from the viewpoint of improvement in elastic modulus and low coefficient of linear thermal expansion.

Further, in order to form other polyimide structural units, 2,2'-bis (trifluoromethyl) benzidine is used in combination, and the diamine used as a copolymerization component includes a diamine having an aromatic ring, and an aliphatic At least one diamine having a ring is included.
Diamines having an aromatic ring include, for example, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 2,5-diaminotoluene, 2,4-diaminoxylene, 2,4-diaminodurene, 4 , 4′-diaminodiphenylmethane, 4,4′-methylenebis(2-methylaniline), 4,4′-methylenebis(2-ethylaniline), 4,4′-methylenebis(2,6-dimethylaniline), 4, 4'-methylenebis(2,6-diethylaniline), 4,4'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 2,4'-diaminodiphenyl ether, 4,4'- Diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminobenzophenone, 3,3'-diaminobenzophenone, 4,4'-diaminobenzanilide, 4-aminophenyl-4'-aminobenzoate, benzidine , 3,3′-dihydroxybenzidine, 3,3′-dimethoxybenzidine, o-tolidine, m-tolidine, 1,4-bis(4-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene , 1,3-bis(3-aminophenoxy)benzene, 4,4′-bis(4-aminophenoxy)biphenyl, bis(4-(3-aminophenoxy)phenyl)sulfone, bis(4-(4-amino phenoxy)phenyl)sulfone, 2,2-bis(4-(4-aminophenoxy)phenyl)propane, 2,2-bis(4-(4-aminophenoxy)phenyl)hexafluoropropane, 2,2-bis( 4-aminophenyl)hexafluoropropane, p-terphenylenediamine and the like.
Diamines having an aliphatic ring include 4,4′-methylenebis(cyclohexylamine), isophoronediamine, trans-1,4-diaminocyclohexane, cis-1,4-diaminocyclohexane, 1,4-cyclohexanebis(methylamine ), 2,5-bis(aminomethyl)bicyclo[2.2.1]heptane, 2,6-bis(aminomethyl)bicyclo[2.2.1]heptane, 3,8-bis(aminomethyl)tricyclo [5.2.1.0] Decane, 1,3-diaminoadamantane, 2,2-bis(4-aminocyclohexyl)propane, 2,2-bis(4-aminocyclohexyl)hexafluoropropane and the like.
These may be used alone or in combination of two or more.

As the diamine used as a copolymerization component to form other polyimide structural units, p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 2,5- of diaminotoluene, 2,4-diaminoxylene, 2,4-diaminodurene, benzidine, 3,3′-dihydroxybenzidine, 3,3′-dimethoxybenzidine, o-tolidine, m-tolidine, and p-terphenylenediamine At least one may be used.

The polyimide resin of the present invention preferably further contains 20 mol % or less of structural units represented by the following formula (3), from the viewpoint of improving the elastic modulus and achieving a low coefficient of linear thermal expansion.
When a structural unit represented by the following formula (3) is included, the structural unit represented by the following formula (3) may be 3 mol% or more of the total structural units, and may be 5 mol% or more, It may be 17 mol % or less of all structural units.

The structural unit represented by the formula (3) can be obtained by reacting pyromellitic dianhydride with 2,2-bis(trifluoromethyl)-4,4-diaminobiphenyl.

In the polyimide resin of the present invention, the total of the structural units represented by the formula (1), the structural units represented by the formula (2), and the structural units represented by the formula (3) is , may be 90 mol % or more, 95 mol % or more, 98 mol % or more, or 100 mol % of the total structural units of the polyimide resin.

Moreover, the polyimide resin which is one embodiment of the present invention may partially have a structure different from the polyimide constitutional unit as long as the effects of the present invention are not impaired.
In the polyimide resin of the present invention, the total of the polyimide structural units may be 90 mol% or more, may be 95 mol% or more, may be 98 mol% or more, and may be 100 It can be mole %.
Structures different from the polyimide structural units include, for example, structural units in which the tetracarboxylic acid component is not completely imidized and has a polyamic acid structure in part, and tricarboxylic acid residues such as trimellitic anhydride. Examples include polyamideimide structural units and polyamide structural units.

For the polyimide resin of the present invention, the ratio of the raw material composition can be confirmed, for example, by the following method, and the content ratio (mol%) of each residue can be obtained.
First, a sodium hydroxide solution is prepared by mixing 2.0 g of sodium hydroxide, 25 mL of water, and 25 mL of methanol, and 200 mg of polyimide resin is dissolved in 10 mL of the sodium hydroxide solution. Depolymerization of the polyimide resin is accelerated by heating the solution at 250° C. for 1 hour in a pressure vessel. The resulting solution is extracted with chloroform and water to separate the decomposition product (raw material monomer). The ratio of the raw material composition is measured by gas chromatography (HP6890/HP5973 manufactured by Agilent Technologies) (the column is "InertCap 5MS/Sil (30m × 250 µm × 0.25 µm, manufactured by GL Sciences)", the measurement conditions are 50 C. for 5 minutes, then heated at 10.degree. C./min to 320.degree.
The content ratio (mol%) of each residue in the polyimide resin can also be obtained from the charging ratio of raw materials at the time of resin production. Also, the structure of the polyimide resin can be determined using NMR, various mass spectrometry, elemental analysis, XPS/ESCA, TOF-SIMS, and the like.

Although not particularly limited as a method for producing a polyimide resin which is one embodiment of the present invention, for example, the tetracarboxylic dianhydride represented by the formula (1-1) and 3,3',4,4'- Two or more tetracarboxylic dianhydrides including benzophenonetetracarboxylic dianhydride and optionally a tetracarboxylic dianhydride having an aromatic ring or an aliphatic ring, and 2,2′-bis( A step of obtaining a polyimide precursor (polyamic acid) by reacting one or more diamines including a diamine having an aromatic ring or an aliphatic ring with a trifluoromethyl)benzidine and, if necessary, It can be produced through a step of imidating the obtained polyimide precursor (polyamic acid).

The tetracarboxylic dianhydride represented by the general formula (1-1) includes 2,2′,3,3′5,5′-hexamethyl-biphenyl-4,4′-diol and trimellitic acids. can be obtained by a known esterification reaction using Examples of the trimellitic acids include trimellitic anhydride and trimellitic anhydride halide. Japanese Patent No. 6165153 can be appropriately referred to for the method for synthesizing the tetracarboxylic dianhydride represented by the general formula (1-1).
As the tetracarboxylic dianhydride having an aromatic ring or an aliphatic ring and the diamine having an aromatic ring or an aliphatic ring, which are used as necessary, the tetracarboxylic dianhydride described above and the A diamine may be appropriately selected and used. A method for producing a tetracarboxylic dianhydride having an aromatic ring or an aliphatic ring and a diamine having an aromatic ring or an aliphatic ring, which are used as necessary, is not particularly limited, and known production A method can be appropriately adopted, and a commercially available product may be used as appropriate.

The polyimide precursor is obtained by reacting the tetracarboxylic dianhydride and the diamine in a solvent. The solvent used for synthesizing the polyimide precursor is not particularly limited as long as it can dissolve the above-mentioned tetracarboxylic dianhydride and diamine, and for example, an aprotic polar solvent can be used. In the present invention, organic solvents containing nitrogen atoms such as N-methyl-2-pyrrolidone, N,N-dimethylformamide and N,N-dimethylacetamide; γ-butyrolactone and the like are preferably used. In addition, an organic solvent is a solvent containing a carbon atom.

As the polymerization reaction procedure, a known method can be appropriately selected and used.
For example, in a low-humidity environment by nitrogen substitution, first, diamine is dissolved in a polymerization solvent in a reaction vessel, and an acid dianhydride substantially equimolar to the diamine is gradually added to the solution, and a mechanical stirrer or the like is used. , a temperature in the range of 0 to 100° C., preferably 20 to 60° C., for 0.5 to 150 hours, preferably 1 to 48 hours. At this time, the monomer concentration is usually in the range of 5 to 50 mass %, preferably in the range of 10 to 40 mass %.

The polyimide precursor solution is prepared by combining at least two tetracarboxylic dianhydrides, and at least two dianhydrides are added at once to a polymerization solvent in which diamine is dissolved to synthesize polyamic acid. Alternatively, at least two kinds of acid dianhydrides may be added step by step in an appropriate molar ratio to the reaction solution to control the sequence in which each raw material is incorporated into the polymer chain to some extent.
For example, by adding a tetracarboxylic dianhydride represented by the general formula (1-1) to a reaction solution in which a diamine is dissolved and reacting, the tetracarboxylic acid represented by the general formula (1-1) An amic acid is synthesized by reacting a dianhydride and a diamine, and 3,3′,4,4′-benzophenonetetracarboxylic dianhydride and, if necessary, a tetracarboxylic acid having an aromatic ring or an aliphatic ring are added thereto. A carboxylic acid dianhydride may be added, and if necessary, a diamine may be further added to polymerize the polyamic acid. When polymerized by this method, the tetracarboxylic dianhydride represented by the general formula (1-1) is introduced into the polyamic acid in a linked form via one diamine.
Polymerizing polyamic acid by such a method involves specifying to some extent the positional relationship of tetracarboxylic acid residues of a specific structure containing a parabiphenylene group with a twisted dihedral angle via an ester bond in the main chain, and It is preferable because the weight average molecular weight by gel permeation chromatography in terms of polystyrene is easily 150,000 or more, and a cured film excellent in elastic modulus and low coefficient of linear thermal expansion is easily obtained.

When the number of moles of diamine in the polyimide precursor solution (polyamic acid solution) is a and the number of moles of tetracarboxylic dianhydride is b, b/a may be 0.9 or more and 1.1 or less. , 0.95 or more and 1.05 or less. In terms of the re-solubility of the coating film and the polystyrene equivalent weight average molecular weight of gel permeation chromatography, it may be 0.98 or more and 1.01 or less, and may be 0.99 or more and less than 1.00. The molecular weight (degree of polymerization) of the polyamic acid to be obtained can be appropriately adjusted by adjusting the amount within such a range, and the terminal functional groups can be adjusted.

In order to prepare a polyimide having a weight average molecular weight of 150,000 or more by gel permeation chromatography in terms of polystyrene, in the preparation of the polyimide precursor, an acid dianhydride is added stepwise to a reaction solution in which diamine is dissolved. It is preferable to carry out the reaction while adding and measuring by gel permeation chromatography to reach the desired molecular weight range.

The polyimide precursor (polyamic acid) may have a weight-average molecular weight of 150,000 or more, 180,000 or more, or 200,000 or more from the viewpoint of excellent mechanical properties of polyimide. good. On the other hand, from the viewpoint of resolubility of the coating film, the polyimide precursor (polyamic acid) may have a weight average molecular weight of 1,000,000 or less, 500,000 or less, and 400, 000 or less.
The weight average molecular weight of polyimide precursors can be measured by gel permeation chromatography (GPC).

As the polyimide precursor (polyamic acid) used for imidization, the polyimide precursor solution obtained by the synthesis reaction may be used as it is, or the solvent of the polyimide precursor solution may be dried and dissolved in another solvent. You can use it as

Methods for imidizing the polyimide precursor include thermal imidization in which a dehydration ring-closing reaction is performed by heating, and chemical imidization in which a dehydration ring-closing reaction is performed using a chemical imidization agent (dehydration ring-closing agent). Among them, it is preferable to use chemical imidization from the viewpoint of avoiding a change in molecular weight due to depolymerization of polyamic acid due to heating.
When chemical imidization is performed, known compounds such as amines such as pyridine and β-picolinic acid, carbodiimides such as dicyclohexylcarbodiimide, and acid anhydrides such as acetic anhydride may be used as chemical imidizing agents. The acid anhydride is not limited to acetic anhydride, and includes propionic anhydride, n-butyric anhydride, benzoic anhydride, trifluoroacetic anhydride and the like, but is not particularly limited. At that time, tertiary amines such as pyridine and β-picolinic acid may be used together. However, if these amines remain in the cured film, they may adversely affect the properties of the cured film. Each of the modifier components may be removed to 100 ppm or less of the total polyimide weight.

The organic solvent used in the reaction liquid for chemical imidization of the polyimide precursor is not particularly limited as long as it can dissolve the polyimide precursor. For example, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphoramide, 1,3-dimethyl-2-imidazolidinone, etc. containing a nitrogen atom Organic solvent; γ-butyrolactone and the like can be used.

Polyimide may have a carboxy group terminal or an amino group terminal at its molecular chain terminal, and the terminal may be blocked with a terminal blocking agent. As the terminal blocking agent, a known terminal blocking agent can be appropriately selected and used, and examples thereof include monoamines, monocarboxylic acids, acid anhydrides, monoacid chloride compounds, and monoactive ester compounds. .
If an acid anhydride is used for chemical imidization during polyimide preparation, the acid anhydride can react with the terminal amino group. The polyimide of one embodiment of the present invention may have an amide bond at the end, which is obtained by chemically imidizing an amino group-terminated polyimide precursor and reacting an acid anhydride with the amino group terminal at the same time. may have an acetamide group.
The polyimide of one embodiment of the present invention may have amide groups at 10% or more of the ends of its molecular chains, and 40 % or more may have amide groups, and 70% or more of the terminals may have amide groups.

As a method of reprecipitating the reaction solution that has been reacted to form the polyimide, a method of dropping the reaction solution into a large amount of poor solvent while stirring is generally used. From the point of easily reducing impurities, as a method of reprecipitating the reaction solution, after diluting the reaction solution reacted to polyimide to an appropriate concentration as necessary, a poor solvent for polyimide is gradually added to the reaction solution. In addition, a method of depositing polyimide is preferred.
When the poor solvent is dropped to precipitate polyimide, the solid content concentration of the reaction solution (polyimide solution) is 0.1% by mass or more and 30% by mass from the viewpoint of yield and efficient removal of impurities. % or less, more preferably 1% by mass or more and 10% by mass or less.
In order to make the solid content concentration of the polyimide solution suitable for deposition of polyimide, it may be diluted with a good solvent for polyimide as appropriate.
As a guideline, the good solvent for polyimide can be appropriately selected from among solvents in which the solubility of polyimide is 20 g/100 g or more at 25°C.
As a guideline, the poor solvent for polyimide can be appropriately selected from solvents in which the solubility of polyimide is less than 20 g/100 g at 25°C.

For example, an organic solvent, which is a good solvent for polyimide, is added to the reaction solution reacted to form polyimide, and the reaction solution is diluted by stirring until uniform, followed by t-butanol, methanol, ethanol, isopropyl alcohol, 2- An alcohol-based organic solvent such as butanol, cyclohexanol, or t-amyl alcohol is gradually added to precipitate polyimide to obtain a white slurry, which is filtered to obtain polyimide. The alcohol-based organic solvent may be a secondary or tertiary alcohol from the viewpoint of excellent stability of the polyimide.

The polyimide obtained by reprecipitation as described above is preferably washed repeatedly with an organic solvent in order to remove the residual solvent.
For example, the polyimide obtained by reprecipitation is washed in an organic solvent for washing, followed by filtration, which is repeated, and dried at 100° C. to 120° C. using a vacuum dryer to obtain polyimide.
The organic solvent for washing has high compatibility with the residual solvent contained in the polyimide obtained by reprecipitation, is a poor solvent for the polyimide, and can be dried at 100° C. to 120° C. using a vacuum dryer. Organic solvents with boiling points below the drying temperature of the vacuum dryer are selected so that they can all volatilize.
For example, when the residual solvent is N,N-dimethylacetamide, N-methyl-2-pyrrolidone, etc., which are used in preparing the polyimide precursor, isopropyl alcohol, methanol, etc. are suitably used as organic solvents for washing. As the cleaning organic solvent, one or two or more can be used.

Polyimide resin of the present invention thus obtained, the weight average molecular weight by polystyrene conversion of gel permeation chromatography, as a lower limit is preferably 150,000 or more, more preferably 180,000 or more, still more preferably It is 200,000 or more, and the upper limit is preferably 1,000,000 or less, more preferably 500,000 or less, and still more preferably 400,000 or less.
When the weight-average molecular weight of the polyimide resin is at least the lower limit, it is preferable because the elastic modulus is improved and a cured film with a reduced coefficient of linear thermal expansion is easily obtained. On the other hand, when it is not more than the above upper limit, it is preferable from the viewpoint that increase in viscosity is suppressed during synthesis, composition preparation, and coating film formation, and it becomes easy to form a coating film or a cured film.
The weight average molecular weight of the polyimide resin can be measured by gel permeation chromatography (GPC). Specifically, the polyimide resin is made into an N-methylpyrrolidone (NMP) solution with a concentration of 0.5% by mass, the solution is filtered through a syringe filter (pore size: 0.45 μm), and the developing solvent is 10 mmol%. Using a LiBr-NMP solution, using a Tosoh GPC device (HLC-8120, column used: SHODEX GPC LF-804), sample injection amount 50 μL, solvent flow rate 0.4 mL / min, 37 ° C. Perform measurement. . The weight average molecular weight is determined based on a polystyrene standard sample having the same concentration as the sample.

In addition, a single cured film of the polyimide resin of the present invention has the same linear thermal expansion coefficient, dielectric constant, dielectric loss tangent, and tensile elastic modulus as described in the cured film of the polyimide composition described later. is preferred.

Further, the polyimide resin of the present invention is a polyimide resin having a high rate of resolubility of the coating film. The polyimide resin of the present invention is, for example, a 10% by mass solution (polyimide composition) of a polyimide resin in which polyimide is dissolved in cyclopentanone or N,N-dimethylacetamide, a width of 20 mm, a length of 50 mm and a thickness of 0.5 mm. After inserting the glass piece of 25 mm with the long side vertical, it is pulled out, and the polyimide composition attached to the glass surface is air-dried at 25 ° C. for 15 hours in a local exhaust device to create a coating film (air-dried film). Cut out a 20 mm × 20 mm test piece from the coating film, put it in a glass vial containing 20 mL of cyclopentanone, stir at 100 rpm with a magnetic stirrer, and measure the time until the coating film completely dissolves. The time can be 30 minutes or less, or even 15 minutes or less.

The polyimide resin of the present invention is a polyimide resin that can form a cured film having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low linear thermal expansion coefficient, and has a fast re-dissolving speed of the coating film. be.
Therefore, the polyimide resin of the present invention can be used, for example, in semiconductor electronic components or semiconductor devices, specifically as a passivation film for semiconductors, a surface protection film for semiconductor elements, an interlayer insulation film, and an interlayer insulation film for multilayer wiring for high-density mounting. , the insulating film of an organic electroluminescence device, and the like.
In addition to the above applications, the polyimide resin of the present invention can be used, for example, as a member for an image display device such as a liquid crystal display device or an organic EL display device, a member for a touch panel, a flexible printed circuit board, a surface protective film or a substrate. It can also be applied to solar cell panel members such as materials, optical waveguide members, other semiconductor-related members, and the like.

II. Polyimide Composition The polyimide composition of the present invention contains the polyimide resin of the present invention and an organic solvent.
The polyimide composition of the present invention may further contain other components as long as the effects of the present invention are not impaired.

The polyimide resin contained in the polyimide composition of the present invention may be the same as the above-described polyimide resin of the present invention, so the description thereof is omitted here.
The organic solvent contained in the polyimide composition can dissolve the polyimide resin of the present invention described above, does not react with each component in the composition, and is not particularly limited as long as it is an organic solvent capable of dissolving or dispersing them. Instead, for example, an aprotic polar solvent or the like can be used.

Examples of organic solvents include ester solvents such as γ-butyrolactone, γ-valerolactone, δ-valerolactone, γ-caprolactone, ε-caprolactone, α-methyl-γ-butyrolactone, butyl acetate, ethyl acetate, and isobutyl acetate. , Ethylene carbonate, carbonate solvents such as propylene carbonate, diethylene glycol dimethyl ether, triethylene glycol, glycol solvents such as triethylene glycol dimethyl ether, phenol, m-cresol, p-cresol, o-cresol, 3-chlorophenol, 4- Phenolic solvents such as chlorophenol, ketone solvents such as cyclopentanone, cyclohexanone, acetone, methyl ethyl ketone, diisobutyl ketone, and methyl isobutyl ketone, ethers such as tetrahydrofuran, 1,4-dioxane, dimethoxyethane, diethoxyethane, and dibutyl ether system solvents and other general-purpose solvents such as acetophenone, 1,3-dimethyl-2-imidazolidinone, sulfolane, dimethyl sulfoxide, propylene glycol methyl acetate, ethyl cellosolve, butyl cellosolve, 2-methyl cellosolve acetate, ethyl cellosolve acetate, butyl cellosolve acetate, chloroform, butanol, ethanol, xylene,
Toluene, chlorobenzene, turpentine, mineral spirits, petroleum naphtha-based solvents, etc., may be mentioned, and two or more of these may be used in combination.
Among the organic solvents contained in the polyimide composition of the present invention, N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethylsulfoxide, hexamethylphosphoramide, 1,3 - organic solvents containing nitrogen atoms such as dimethyl-2-imidazolidinone; γ-butyrolactone, cyclopentanone, tetrahydrofuran and the like are preferably used.

In the polyimide composition of the present invention, the content of the organic solvent is not particularly limited, and may be set as appropriate depending on the purpose of use and processing conditions, for example, within a range that provides the viscosity described later. The content of the organic solvent is usually in the range of preferably 70% by mass to 95% by mass, more preferably 75% by mass to 90% by mass, based on the total amount of the polyimide composition containing the organic solvent.

The present invention also provides, as one preferred embodiment of a polyimide composition, the polyimide resin of the present invention, an epoxy compound having three or more epoxy groups in one molecule and having a glycidylamine moiety, and an organic and a solvent.
The polyimide composition of the embodiment A contains, in addition to the polyimide resin of the present invention, an epoxy compound having three or more epoxy groups in one molecule and having a glycidylamine moiety, thereby forming an inorganic compound or A cured film of the polyimide composition having improved adhesion to metal can be formed. An epoxy compound having three or more epoxy groups in one molecule and having a glycidylamine site has an amine site, so that it is compatible with the polyimide resin of the present invention, or to the organic solvent used in the present invention. Also excellent in solubility, reactivity during heating and stability during non-heating (storage stability as a polyimide composition), and the terminal amino group, carboxy group, and acetamide group of the polyimide resin etc. and the epoxy group can react. By bonding the epoxy compound to the end of the polyimide resin, the epoxy group of the epoxy compound is ring-opened and many hydroxyl groups are generated, and the characteristics of the polyimide resin of the present invention, that is, low dielectric loss tangent, high elastic modulus, and It is presumed that a cured film of a polyimide composition having improved adhesion to inorganic compounds and metals can be formed while taking advantage of its low coefficient of linear thermal expansion.
In addition, the polyimide composition of Embodiment A can further improve mechanical properties such as tensile elastic modulus as compared with the polyimide resin alone, because the epoxy compound is bonded to the terminal of the polyimide resin.

Epoxy compounds having three or more epoxy groups in one molecule and having a glycidylamine moiety include, for example, saturated or unsaturated aliphatic compounds, alicyclic compounds, aromatic compounds, heterocyclic compounds, or Combinations thereof having a glycidyl amine moiety and further having a glycidyl ether moiety derived from compounds having two or more amino groups, or one or more amino groups and one or more hydroxyl groups. and epoxy compounds that may be used.

Specifically, for example, an epoxy compound having a glycidylamine moiety derived from xylylenediamine such as meta-xylylenediamine and para-xylylenediamine, and a glycidylamine moiety derived from 1,3-bis(aminomethyl)cyclohexane. epoxy compound having a glycidylamine moiety derived from diaminodiphenylmethane, epoxy compound having a glycidylamine moiety derived from para-aminophenol and a glycidyl ether moiety, glycidylamine derived from 4-amino-3-methylphenol and an epoxy compound having a site and a glycidyl ether site.

More specifically, for example, N,N,N',N'-tetraglycidylmetaxylylenediamine, N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane, N,N,N ',N'-tetraglycidyl-4,4-(4-aminophenyl)-p-diisopropylbenzene, 1,1,2,2-(tetraglycidyloxyphenyl)ethane, 1,1,2,2- Tetrabis(hydroxyphenyl)ethane tetraglycidyl ether, tetraglycidyl-1,3-bisaminomethylcyclohexane, N-[2-methyl-4-(oxiranylmethoxy)phenyl]-N-(oxiranylmethyl)oxiranemethane Amine etc. are mentioned.
Among them, an epoxy compound containing a skeleton structure represented by the following chemical formula (I) in the molecule is more preferable.

As the epoxy compound having three or more epoxy groups in one molecule and having a glycidylamine moiety used in the present invention, glycidylamine derived from metaxylylenediamine is preferred from the viewpoint of compatibility and solubility. moieties, epoxy compounds having glycidylamine moieties derived from diaminodiphenylmethane, and epoxy compounds having glycidylamine moieties and glycidyl ether moieties derived from 4-amino-3-methylphenol. An epoxy compound having a glycidylamine moiety derived from metaxylylenediamine, and an epoxy having a glycidylamine moiety and a glycidyl ether moiety derived from 4-amino-3-methylphenol It is more preferable to contain one or more selected from the group consisting of compounds.

The epoxy compound used in the present invention can be produced by a conventionally known production method and obtained by reacting various alcohols, phenols and amines with epihalohydrin. For example, an epoxy compound having a glycidylamine moiety derived from metaxylylenediamine can be obtained by adding epichlorohydrin to metaxylylenediamine.

Among the epoxy compounds having three or more epoxy groups in one molecule and having a glycidylamine moiety used in the present invention, from the viewpoint of compatibility and solubility, N represented by the following chemical formula (Ia) , N,N′,N′-tetraglycidylmetaxylylenediamine, N,N,N′,N′-tetraglycidyl-4,4′-diaminodiphenylmethane represented by the following chemical formula (Ib), and the following chemical formula ( Ic) may be one or more selected from the group consisting of N-[2-methyl-4-(oxiranylmethoxy)phenyl]-N-(oxiranylmethyl)oxiranemethanamine, N,N,N',N'-tetraglycidylmetaxylylenediamine represented by the following chemical formula (Ia) and N-[2-methyl-4-(oxiranylmethoxy) represented by the following chemical formula (Ic) Phenyl]-N-(oxiranylmethyl)oxiranemethanamine, which may be one or more selected from the group consisting of N,N,N',N'-tetraglycidyl represented by the following chemical formula (Ia) It may be meta-xylylenediamine.
As the epoxy compound used in the present invention, commercially available products may be appropriately selected and used. (above, manufactured by Sumitomo Chemical) and the like can be used.

As the epoxy compound having three or more epoxy groups in one molecule and having a glycidylamine moiety, one type may be used alone, or two or more types may be used in combination.
The content of the epoxy compound having three or more epoxy groups in one molecule and having a glycidylamine moiety may be appropriately selected depending on the balance between desired adhesion and desired physical properties, and is not particularly limited. For 100 parts by mass of the polyimide resin of the present invention, it may be, for example, 5 to 35 parts by mass, preferably 10 to 20 parts by mass.

The polyimide composition of Embodiment A may further contain a silane coupling agent from the viewpoint of improving adhesion. As the silane coupling agent, a known silane coupling agent can be appropriately selected and used.
The silane coupling agent used in the polyimide composition of Embodiment A may be a compound represented by the following general formula (A) from the viewpoint of further improving adhesion.

（式（Ａ）中、Ｒ^ａは、グリシジル基、（メタ）アクリロイル基、酸無水物基、ヒドロキシ基、トリアジン基、及びアミノ基からなる群から選択される少なくとも１種を含む１価の基を表し、Ｒ^ｂ及びＲ^ｃはそれぞれ独立に、炭素数１～５のアルキル基であり、ｎは１～１０の整数であり、ｍは１～３の整数である。）

(In the formula (A), R ^a is a monovalent group containing at least one selected from the group consisting of a glycidyl group, a (meth)acryloyl group, an acid anhydride group, a hydroxy group, a triazine group, and an amino group. and R ^b and R ^c are each independently an alkyl group having 1 to 5 carbon atoms, n is an integer of 1 to 10, and m is an integer of 1 to 3.)

R ^b and R ^c may each independently be an alkyl group having 1 to 3 carbon atoms, and may be a methyl group or an ethyl group.
n may be 1-5.

Examples of compounds represented by the following general formula (A) include hydroxymethyltrimethoxysilane, hydroxymethyltriethoxysilane, 2-hydroxyethyltrimethoxysilane, 2-hydroxyethyltriethoxysilane, and 3-hydroxypropyltrimethoxysilane. Silane, 3-hydroxypropyltriethoxysilane, 4-hydroxybutyltrimethoxysilane, 4-hydroxybutyltriethoxysilane, glycidoxymethyltrimethoxysilane, glycidoxymethyltriethoxysilane, 2-glycidoxyethyltrimethoxysilane Silane, 2-glycidoxyethyltriethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 4-glycidoxybutyltrimethoxysilane, 4-glycidoxybutyltriethoxysilane Silane, bis(2-hydroxymethyl)-3-aminopropyltriethoxysilane, bis(2-hydroxymethyl)-3-aminopropyltrimethoxysilane, bis(2-glycidoxymethyl)-3-aminopropyltriethoxysilane Silane, bis(2-hydroxymethyl)-3-aminopropyltrimethoxysilane, ureidomethyltrimethoxysilane, ureidomethyltriethoxysilane, 2-ureidoethyltrimethoxysilane, 2-ureidoethyltriethoxysilane, 3-ureidopropyl Trimethoxysilane, 3-ureidopropyltriethoxysilane, 4-ureidobutyltrimethoxysilane, 4-ureidobutyltriethoxysilane, 3-trimethoxysilylpropylsuccinic anhydride, 3-(meth)acryloyloxypropyltrimethoxysilane , 3-(meth)acryloyloxypropyltriethoxysilane, 3-(meth)acryloyloxypropylmethyldimethoxysilane, and compounds represented by the following formula (a-1). The compound represented by the following formula (a-1) can be prepared with reference to JP-A-62-100462.

（式（ａ－１）中、Ｒ^ｄは、－ＣＨ_２ＣＨ_２－Ｓ－、又は、－ＣＨ_２ＣＨ_２－ＮＨ－を表し、Ｒ^ｂ及びＲ^ｃはそれぞれ独立に、炭素数１～５のアルキル基であり、ｎは１～１０の整数であり、ｍは１～３の整数である。）

(In formula (a-1), R ^d represents —CH ₂ CH ₂ —S— or —CH ₂ CH ₂ —NH—, and R ^b and R ^c each independently have 1 to 5 carbon atoms. is an alkyl group, n is an integer of 1 to 10, and m is an integer of 1 to 3.)

As the silane coupling agent used in the polyimide composition of Embodiment A, in the compound represented by the general formula (A), ^Ra is selected from the group consisting of a glycidyl group, a triazine group, and an amino group. may represent a monovalent group containing at least one of the above formula It may be a compound represented by (a-1).

As said silane coupling agent, you may use individually by 1 type, and may use 2 or more types together.
The content of the silane coupling agent may be appropriately selected depending on the balance of desired adhesion and desired physical properties, and is not particularly limited. It may be from 0.5 to 5 parts by mass, preferably from 0.5 to 5 parts by mass.

In addition to the above components, the polyimide composition of the present invention including Embodiment A further contains a photosensitive compound, a cross-linking agent, an antioxidant, a surfactant, a leveling agent, inorganic or organic fine particles, an antirust agent, and the like. may contain.

The polyimide composition can be prepared by dissolving the above-mentioned polyimide resin of the present invention in an organic solvent and, if necessary, dissolving or dispersing other components.
The content of the polyimide resin in the polyimide composition is not particularly limited, and may be appropriately selected according to the application.
The polyimide composition used for the cured film of the polyimide composition of the present invention described later may have a polyimide resin content of 5% by mass or more, or 10% by mass or more, relative to the total amount of the polyimide composition. It may be 30% by mass or less, and may be 25% by mass or less.

The viscosity of the polyimide composition is not particularly limited as long as it is appropriately selected according to the application.
The polyimide composition used in the method for producing a cured film of the polyimide composition of the present invention, which will be described later, has a viscosity at 25 ° C. measured by a rotational viscometer of preferably 1000 mPa s or more, more preferably 3000 mPa s or more, It is preferably 50,000 mPa·s or less, more preferably 30,000 mPa·s or less.
Here, the viscosity of the polyimide composition is determined by the method described in JIS K7117-1 using a single cylindrical rotational viscometer (for example, TVB-10 type viscometer manufactured by Toki Sangyo Co., Ltd.) at 25 ° C. can be measured.

III. Cured Film of Polyimide Composition The present invention provides a cured film of a polyimide composition obtained by curing the polyimide composition of the present invention.
The cured film of the polyimide composition according to the present invention contains the polyimide resin contained in the polyimide composition of the present invention, the solid content of other components, and their reaction products.

The cured film of the polyimide composition of the present invention may have a dielectric constant of 3.60 or less at a frequency of 10 GHz in accordance with JIS R1641 from the viewpoint of reducing electrical signal loss when used as a semiconductor packaging material. , may be 3.30 or less, may be 3.20 or less, or may be 3.00 or less. In addition, the cured film of the polyimide composition of the present invention has a dielectric loss tangent at a frequency of 10 GHz conforming to JIS R1641 from the viewpoint of reducing electrical signal loss when used as a semiconductor packaging material, etc. is 0.020 or less. may be less than or equal to 0.015, and may be less than or equal to 0.012.
The dielectric constant and dielectric loss tangent of the cured film of the polyimide composition are measured according to JIS R1641 by the split cylinder method using a split cylinder resonator device (CR-710, manufactured by Kanto Electronics Applied Development Co., Ltd.). can be measured as 10 GHz.
In addition, the test piece used for measurement was dried in an oven at 110 ° C. for 30 minutes as a pre-measurement treatment, and then placed in an environmental tester (SH-662, manufactured by Espec Co., Ltd.) at 23 ° C. and a humidity of 50%. Conditioning is performed for 24 hours, and dielectric constant and dielectric loss tangent measurements are performed immediately after removing the test piece from the environmental tester.

The cured film of the polyimide composition of the present invention has a coefficient of linear thermal expansion of 30 ppm or less, 27 ppm or less, and 25 ppm from the viewpoint of dimensional stability when used for semiconductor packaging materials and the like. or less, and may be 20 ppm or less. Here, the linear thermal expansion coefficient in the present invention is measured by a thermomechanical analyzer (for example, a thermomechanical analyzer (TMA-60) manufactured by Shimadzu Corporation) with a load of 9 g and a heating rate of 10 ° C./min to 30 ° C. It can be calculated from the TMA curve when the temperature is raised to 400°C. The coefficient of linear thermal expansion is obtained as an average value between 100 and 150°C.

The cured film of the polyimide composition of the present invention may have a tensile modulus at 25° C. of 4.5 GPa or more, or 5.0 GPa or more. Thus, a high tensile modulus at 25° C. (room temperature) is advantageous in terms of physical stability of the package when used in new semiconductor packages of the type in which a plurality of semiconductor packages are vertically integrated. be. On the other hand, the tensile modulus of elasticity may be 10.0 GPa or less from the viewpoint of brittle fracture.
The tensile test conforms to JIS K7127, using a tensile tester (for example, manufactured by Shimadzu Corporation: Autograph AG-X 1N, load cell: SBL-1KN), a test piece of width 10 mm × length 150 mm of the polyimide composition. It can be cut out from the cured film and stretched at 25° C. at a stretching rate of 50 mm/min and a distance between grippers of 100 mm. The tensile modulus can be determined from the initial slope of the stress-strain curve. The thickness of the cured film of the polyimide composition when performing the tensile test may be 35 μm to 55 μm.

The cured film of the polyimide composition of the present invention, especially the cured film of the polyimide composition of Embodiment A, has adhesion to a silicon nitride substrate, does not peel off in a cross-cut test method in accordance with JIS K 5400-8.5. The number of grids may be 80% or more of the whole, 90% or more, or 100%.
The cured film of the polyimide composition of the present invention, especially the cured film of the polyimide composition of Embodiment A, has adhesion to a copper substrate, which is a grid that does not peel off by a grid test method in accordance with JIS K 5400-8.5. The number of eyes may be 80% or more of the whole, 90% or more, or 100%.

The thickness of the cured film of the polyimide composition of the present invention may be appropriately selected depending on the application, and is not particularly limited. or more. On the other hand, it may be 100 μm or less, 70 μm or less, or 50 μm or less.

Moreover, the cured film of the polyimide composition of the present invention may be subjected to surface treatment such as saponification treatment, glow discharge treatment, corona discharge treatment, ultraviolet treatment, and flame treatment.

[Method for producing cured film of polyimide composition]
The method for producing the cured film of the polyimide composition of the present invention is not particularly limited as long as it is a method capable of producing the cured film of the polyimide composition of the present invention.
As a method for producing a cured film of the polyimide composition of the present invention,
A step of applying the polyimide composition onto a substrate and drying to form a coating film;
Examples include a method for producing a cured film of a polyimide composition, which includes the step of forming a cured film by heating the coating film.

The substrate used in the step of forming the coating film is not particularly limited. Examples of substrates include glass substrates, semiconductor substrates such as Si substrates (silicon wafers), metal oxide insulator substrates such as _TiO2 substrates and _SiO2 substrates, silicon nitride substrates, copper substrates, copper alloy substrates, and polyimide substrates. Composite substrates in which resin films such as films are laminated, substrates in which circuit constituent materials are arranged on these substrates, and the like can be mentioned.

The coating means is not particularly limited as long as it can be coated with the desired film thickness. can be done.

After coating the polyimide composition on the substrate, it is dried to form a coating film. The drying temperature includes a temperature of less than 150°C, preferably 30°C or more and 140°C or less.

The drying time may be appropriately adjusted according to the film thickness of the coating film of the polyimide composition, the type of solvent, the drying temperature, etc., but is usually 5 minutes to 60 minutes, preferably 10 minutes to 40 minutes. good. When the upper limit is exceeded, it is not preferable from the viewpoint of the production efficiency of the cured film of the polyimide composition. On the other hand, if it is less than the lower limit, there is a risk that rapid drying of the solvent may affect the appearance of the resulting cured film of the polyimide composition.

The method for drying the solvent is not particularly limited as long as the solvent can be dried at the above temperature.
The atmosphere during drying of the solvent may be the air or an inert gas atmosphere.

A cured film is formed by heating the coating film.
The temperature for heating the coating film may be 150° C. or higher and 240° C. or lower, and 170° C. or higher and 235° C. or lower from the viewpoint of promoting the curing reaction and heat resistance of other semiconductor packaging materials such as sealing materials. and may be 200° C. or more and 230° C. or less.
As a heating means for forming the cured film, the same heating means as for the drying described above can be used.
The atmosphere during heating of the coating film may be the air or an inert gas atmosphere.

The heating time may be appropriately adjusted depending on the film thickness of the coating film, and is usually 10 minutes to 2 hours, preferably 30 minutes to 1 hour.

In the case where the polyimide composition contains a photosensitive component, pattern exposure is performed after the formation of the coating film, and a patterned coating film is formed by appropriately developing the coating film, and the patterned coating film is heated. , a patterned cured film may be formed.

Although the use of the cured film of the polyimide composition of the present invention is not particularly limited, it has a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low coefficient of linear thermal expansion, and can have higher adhesion. Therefore, for example, in semiconductor electronic components or semiconductor devices, specifically, semiconductor passivation films, surface protective films of semiconductor elements, interlayer insulating films, interlayer insulating films of multilayer wiring for high-density mounting, organic electroluminescent elements It can be suitably used for applications such as insulating films. In addition, the cured film of the polyimide composition of the present invention is used for image display device members such as liquid crystal display devices and organic EL display devices, touch panel members, flexible printed circuit boards, surface protective films and substrate materials for solar cell panels. It can also be applied to members, optical waveguide members, other semiconductor-related members, and the like.

IV. Insulating films, protective films, and electronic components

The present invention provides an insulating film formed using the cured film of the polyimide composition according to the present invention.
The present invention also provides a protective film formed using the cured film of the polyimide composition according to the present invention.
The present invention also provides an electronic component including the insulating film according to the present invention or the protective film according to the present invention.

The insulating film or protective film may be a film having both functions of an insulating film and a protective film. can.

Highly reliable electronic components such as semiconductor devices, multilayer wiring boards, and various electronic devices using one or more selected from the group consisting of the passivation film, buffer coat film, interlayer insulating film, surface protective film, etc. etc. can be produced.

An example of the manufacturing process of the semiconductor device, which is the electronic component of the present invention, will be described with reference to the drawings.
FIG. 1 is a manufacturing process diagram of a semiconductor device having a multilayer wiring structure, which is an electronic component according to one embodiment of the present invention.
As shown in FIG. 1A, a semiconductor substrate 1 such as a Si substrate having circuit elements is covered with a protective film 2 such as a silicon oxide film except for predetermined portions of the circuit elements. A first conductor layer 3 is formed. After that, an interlayer insulating film 4 is formed on the semiconductor substrate 1 .

Next, as shown in FIG. 1B, a photosensitive resin layer 5 is formed on the interlayer insulating film 4, and a window 6A is provided by a known photolithographic technique so that a predetermined portion of the interlayer insulating film 4 is exposed. be done.

As shown in FIG. 1C, the interlayer insulating film 4 with the window 6A exposed is selectively etched by a suitable known method to provide a window 6B.
Next, the photosensitive resin layer 5 is removed using an etching solution that corrodes the photosensitive resin layer 5 without corroding the first conductor layer 3 exposed from the window 6B.

As shown in FIG. 1(D), a second conductor layer 7 is formed and electrically connected to the first conductor layer 3 using a known photolithography technique.
In the case of forming a multilayer wiring structure having three or more layers, the above steps can be repeated to form each layer.

Next, as shown in FIG. 1E, the polyimide composition of the present invention is used to form a cured film of the polyimide composition, a window 6C is opened with a laser or the like, and a surface protection film 8 is formed. . Alternatively, when the polyimide composition of the present invention contains a photosensitive component and is a photosensitive composition, a coating film of the polyimide composition is formed, and the window 6C is opened by pattern exposure to form a cured film. The surface protection film 8 may be formed by The surface protection film 8 protects the second conductor layer 7 from external stress, α-rays, etc., and the resulting semiconductor device has excellent reliability.
In the above example, the interlayer insulating film may be formed using the polyimide composition of the present invention.

[Evaluation method]
Hereinafter, measurement or evaluation was performed at 25° C. unless otherwise specified. Moreover, room temperature is 25 degreeC.
A specimen of the film was cut from near the center of the film.

<Weight average molecular weight of polyimide>
The polyimide was made into an N-methylpyrrolidone (NMP) solution with a concentration of 0.5% by mass, the solution was filtered through a syringe filter (pore size: 0.45 μm), and a 10 mmol% LiBr-NMP solution was used as a developing solvent. Using a GPC device (manufactured by Tosoh, HLC-8120, detector: differential refractive index (RID) detector, column used: GPC LF-804 manufactured by SHODEX), sample injection amount 50 μL, solvent flow rate 0.4 mL / min, Measurement was performed under the conditions of a column temperature of 37°C and a detector temperature of 37°C. The weight-average molecular weight of the polyimide was measured using a polystyrene standard sample with the same concentration as the sample (weight-average molecular weight: 364,700, 204,000, 103,500, 44,360, 27,500, 13,030, 6,300, 3, 070) was converted to standard polystyrene. The elution time was compared with the calibration curve to obtain the weight average molecular weight.

<Confirmation of imidization rate of polyimide ( ¹ H NMR)>
About 10 mg of polyimide was dissolved in 0.75 mL of deuterated dimethyl sulfoxide to which 0.03 vol% of tetramethylsilane (TMS) was added, and ¹ H nuclei were integrated using a Fourier transform nuclear magnetic resonance spectrometer (AVANCE400, manufactured by Bruker). Measurement was performed under the condition of 256 times. TMS was used as a reference (0 ppm) for chemical shift, and a signal derived from carboxy proton (around 13 ppm) and a signal derived from amide proton (around 11 ppm) of polyamic acid were confirmed.

<Evaluation of resolubility of polyimide coating>
A piece of glass having a width of 20 mm, a length of 50 mm and a thickness of 0.5 mm was inserted into the prepared polyimide composition for 25 mm with the long side vertical, and then pulled out. C. for 15 hours to form a coating film (air-dried film). A 20 mm x 20 mm test piece is cut out from the coating film, and the test piece is placed in a glass vial containing 20 mL of cyclopentanone, stirred at 100 rpm with a magnetic stirrer, and the time until the coating film is completely dissolved. Measured.
(Evaluation criteria)
○: Dissolution time is 15 minutes or less △: Dissolution time is over 15 minutes and 30 minutes or less ×: Dissolution time is over 30 minutes

<Method for measuring film thickness of cured film>
The film thickness of a test piece of a cured film of a polyimide composition cut into a size of 100 mm × 100 mm is measured at a total of 5 points at the four corners and the center using a digital linear gauge (manufactured by Ozaki Seisakusho Co., Ltd., model PDN12 digital gauge). The average of the measured values was taken as the film thickness of the cured film of the polyimide composition.

<Thermal property evaluation: linear thermal expansion coefficient>
Using a test piece of a cured film of a polyimide composition cut into a size of 5 mm × 10 mm, a thermomechanical analyzer (TMA-60, manufactured by Shimadzu Corporation) was analyzed at a load of 9 g and a temperature of 30 ° C. to 400 ° C. at 10 ° C./min. A TMA curve was obtained when the temperature was raised to °C.
The coefficient of linear thermal expansion was obtained as an average value between 100 and 150°C.

<Evaluation of electrical properties: permittivity, dielectric loss tangent>
Using a test piece of a cured film of a polyimide composition cut into a size of 70 mm × 70 mm, a split cylinder resonator device (CR-710, manufactured by Kanto Electronics Applied Development Co., Ltd.) was manufactured by the split cylinder method in accordance with JIS R1641. , the dielectric constant and dielectric loss tangent were measured at a measurement frequency of 10 GHz.
Before measurement, the test piece used for measurement was dried in an oven at 110 ° C. for 30 minutes, and then conditioned in an environmental tester SH-662 (manufactured by Espec Co., Ltd.) at 23 ° C. and a humidity of 50% for 24 hours. After the measurement, it was taken out from the environmental tester and immediately measured.

<Mechanical property evaluation (tensile test): tensile modulus>
The tensile test conforms to JIS K7127, using a test piece of a cured film of a polyimide composition cut into a size of 10 mm in width × 150 mm in length, using a tensile tester (for example, manufactured by Shimadzu Corporation: Autograph AG-X 1N , load cell: SBL-1KN) at 25° C. with a drawing speed of 50 mm/min and a distance between grips of 100 mm.
Tensile modulus was determined from the initial slope of the stress-strain curve.

<Evaluation of Adhesion: Cross-cut Test>
It was carried out according to JIS K5400-8.5 cross-cut test. After the test was conducted, the number of squares (number of remaining squares) of the cured film remaining on the substrate without being peeled off was measured among all 100 squares.
As the silicon nitride substrate, a SiN 100 nm film-formed Si substrate manufactured by Assist Navi was used, and as the copper substrate, a Cu 100 nm/Ti 50 nm film-formed Si substrate manufactured by Assist Navi was used. The substrate was immersed in isopropyl alcohol, subjected to ultrasonic cleaning for 5 minutes, dried, and then used to produce a cured film of the polyimide composition.

(Example 1)
(1) Synthesis of Polyimide Resin A tetracarboxylic dianhydride (TMPBP-TME) represented by the following chemical formula (1-1) was synthesized with reference to Synthesis Example 1 of Japanese Patent No. 6165153.

Dehydrated N,N-dimethylacetamide (DMAc) (300 g) and 2,2′-bis(trifluoromethyl)benzidine (TFMB) (20.79 g, 64.9 mmol) was added and stirred at room temperature to dissolve TFMB. To the above solution were added TMPBP-TME (25.45 g, 41.1 mmol), 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA) (4.14 g, 12.9 mmol), pyromellitic acid. Anhydride (PMDA) (2.24 g, 10.3 mmol) was added in several portions and then stirred at room temperature for 15 hours to obtain a polyimide precursor solution (solid content of about 15 mass %) was obtained.
A mixed solution of 25.50 g of acetic anhydride and 0.99 g of pyridine was slowly added dropwise to the obtained polyimide precursor solution at room temperature. rice field.
After diluting the resulting polyimide solution with DMAc to a solid concentration of about 5% by mass, the solution was slowly added dropwise to a large amount of isopropyl alcohol with stirring to precipitate polyimide. The resulting precipitate was filtered, the cake was washed with isopropyl alcohol, and dried at 110° C. for 8 hours using a vacuum dryer to obtain polyimide resin 1.
The obtained polyimide resin 1 was subjected to ¹ H NMR measurement, and it was confirmed that signals derived from carboxy protons and amide protons of polyamic acid disappeared, that is, complete imidization was confirmed.

(2) Preparation of polyimide composition A solvent (a mixed solvent having a weight ratio of DMAc and ethyl acetate (EA) of 1:1) was added to the obtained polyimide resin 1, and the polyimide was dissolved by stirring at room temperature, and the polyimide concentration was A homogeneous solution containing 10% by weight of was prepared. This solution was subjected to pressure filtration using a 400-mesh wire mesh to obtain a polyimide composition 1.

(3) Production of Cured Film of Polyimide Composition The resulting polyimide composition was spin-coated onto a glass substrate on which a polyimide film (UPILEX 125S, manufactured by Ube Industries, Ltd.) was adhered. The spin coating conditions were adjusted so that the film thickness of the finally obtained cured film of the polyimide composition was about 40 to 50 μm.
After the polyimide composition was spin-coated, the substrate was heated on a hot plate to dry the solvent (heated at 40° C. for 8 minutes, heated at 80° C. for 8 minutes, then heated at 130° C. for 8 minutes).
After drying, the substrate was placed in an oven, heat-treated at 230° C. for 1 hour in the air, cooled to room temperature, and then the cured film of the polyimide composition was peeled off from the substrate.
Table 1 shows the evaluation results of the cured film of the obtained polyimide composition.

(Example 2)
In the synthesis of the polyimide resin of Example 1, 20.63 g (64.4 mmol) of TFMB, 24.85 g (40.2 mmol) of TMPBP-TME, 6.16 g (19.1 mmol) of BTDA, and 0.97 g of PMDA (4.46 mmol), 26.31 g of acetic anhydride and 1.02 g of pyridine were used. The obtained polyimide resin 2 was subjected to ¹ H NMR measurement, and it was confirmed that signals derived from carboxy protons and amide protons of polyamic acid disappeared, that is, complete imidization was confirmed.
A cured film of a polyimide composition was produced in the same manner as in Example 1, except that polyimide resin 2 was used instead of polyimide resin 1. Table 1 shows the evaluation results of the cured film of the obtained polyimide composition.

(Example 3)
In the synthesis of the polyimide resin of Example 1, 22.00 g (68.7 mmol) of TFMB, 18.96 g (30.6 mmol) of TMPBP-TME, 10.96 g (34.0 mmol) of BTDA, and 0.74 g of PMDA (3.40 mmol), a polyimide resin was synthesized in the same manner as in Example 1, except that 28.06 g of acetic anhydride and 1.09 g of pyridine were used, and polyimide resin 3 was obtained. The obtained polyimide resin 3 was subjected to ¹ H NMR measurement, and it was confirmed that signals derived from carboxy protons and amide protons of polyamic acid disappeared, that is, complete imidization was confirmed.
A cured film of a polyimide composition was produced in the same manner as in Example 1, except that Polyimide Resin 3 was used instead of Polyimide Resin 1. Table 1 shows the evaluation results of the cured film of the obtained polyimide composition.

(Example 4)
In the synthesis of the polyimide resin of Example 1, 21.36 g (66.7 mmol) of TFMB, 22.87 g (37.0 mmol) of TMPBP-TME, 6.38 g (19.8 mmol) of BTDA, and 2.02 g of PMDA (9.24 mmol), and 27.24 g of acetic anhydride and 1.06 g of pyridine were used to synthesize a polyimide resin and obtain polyimide resin 4 in the same manner as in Example 1. The obtained polyimide resin 4 was subjected to ¹ H NMR measurement, and it was confirmed that signals derived from carboxy protons and amide protons of polyamic acid disappeared, that is, complete imidization was confirmed.
A cured film of a polyimide composition was produced in the same manner as in Example 1, except that polyimide resin 4 was used instead of polyimide resin 1. Table 1 shows the evaluation results of the cured film of the obtained polyimide composition.
In addition, for adhesion evaluation, the substrate was changed to a silicon nitride substrate, and a cured film of the polyimide composition was produced on the silicon nitride substrate in the same manner as in Example 1. The adhesion was evaluated without removing the cured film of the polyimide composition from the substrate. Table 2 shows adhesion evaluation.

(Comparative example 1)
In the synthesis of the polyimide resin of Example 1, TFMB was changed to 18.18 g (56.8 mmol), TMPBP-TME was changed to 34.76 g (56.2 mmol) as a tetracarboxylic dianhydride, and acetic anhydride was changed to 23.18 g. A polyimide resin was synthesized in the same manner as in Example 1, except that 0.90 g of pyridine was used, and a comparative polyimide resin 1 was obtained. The obtained comparative polyimide resin 1 was subjected to ¹ H NMR measurement, and it was confirmed that signals derived from carboxy protons and amide protons of polyamic acid had disappeared, that is, complete imidization was confirmed.
A cured film of a polyimide composition was produced in the same manner as in Example 1, except that Comparative Polyimide Resin 1 was used instead of Polyimide Resin 1. Table 1 shows the evaluation results of the cured film of the obtained polyimide composition.

(Comparative example 2)
In the synthesis of the polyimide resin of Example 1, 18.86 g (58.9 mmol) of TFMB, 32.46 g (52.5 mmol) of TMPBP-TME as tetracarboxylic dianhydride and 1.27 g (5.83 mmol) of PMDA ), and 24.05 g of acetic anhydride and 0.93 g of pyridine were used, and a polyimide resin was synthesized in the same manner as in Example 1 to obtain a comparative polyimide resin 2. ¹ H NMR measurement was performed on the obtained comparative polyimide resin 2, and it was confirmed that signals derived from carboxy protons and amide protons of polyamic acid disappeared, that is, complete imidization was confirmed.
A cured film of a polyimide composition was produced in the same manner as in Example 1, except that Comparative Polyimide Resin 2 was used instead of Polyimide Resin 1. Table 1 shows the evaluation results of the cured film of the obtained polyimide composition.

(Comparative Example 3)
In the synthesis of the polyimide resin of Example 1, 18.86 g (58.9 mmol) of TFMB, 31.15 g (50.4 mmol) of TMPBP-TME as tetracarboxylic dianhydride and 1.22 g (5.56 mmol) of PMDA ), and 24.05 g of acetic anhydride and 0.93 g of pyridine were used, and a polyimide resin was synthesized in the same manner as in Example 1 to obtain a comparative polyimide resin 3. The resulting comparative polyimide resin 3 was subjected to ¹ H NMR measurement, and it was confirmed that signals derived from carboxy protons and amide protons of polyamic acid disappeared, that is, complete imidization was confirmed.
A cured film of a polyimide composition was produced in the same manner as in Example 1, except that Comparative Polyimide Resin 3 was used instead of Polyimide Resin 1. Table 1 shows the evaluation results of the cured film of the obtained polyimide composition.

(Comparative Example 4)
In the synthesis of the polyimide resin of Example 1, 20.06 g (62.6 mmol) of TFMB, 31.43 g (50.7 mmol) of TMPBP-TME as tetracarboxylic dianhydride and 1.22 g (5.63 mmol) of PMDA ), and 25.58 g of acetic anhydride and 0.99 g of pyridine were used, and a polyimide resin was synthesized in the same manner as in Example 1 to obtain a comparative polyimide resin 4. The obtained comparative polyimide resin 4 was subjected to ¹ H NMR measurement, and it was confirmed that signals derived from carboxy protons and amide protons of polyamic acid disappeared, that is, complete imidization was confirmed.
A cured film of a polyimide composition was produced in the same manner as in Example 1, except that Comparative Polyimide Resin 4 was used instead of Polyimide Resin 1. Table 1 shows the evaluation results of the cured film of the obtained polyimide composition.

(Comparative Example 5)
In the synthesis of the polyimide resin of Example 1, 19.75 g (61.7 mmol) of TFMB, 23.79 g (38.4 mmol) of TMPBP-TME as a tetracarboxylic dianhydride, 4,4′-(hexafluoroisopropyl Changed to 8.14 g (18.3 mmol) of 6FDA and 0.93 g (4.27 mmol) of PMDA, 25.19 g of acetic anhydride, and 0.98 g of pyridine. A polyimide resin was synthesized in the same manner as in Example 1, except that the polyimide resin 5 was obtained. The obtained comparative polyimide resin 5 was subjected to ¹ H NMR measurement, and it was confirmed that the signals derived from the carboxy protons and amide protons of the polyamic acid disappeared, that is, complete imidization was confirmed.
A cured film of a polyimide composition was produced in the same manner as in Example 1, except that Comparative Polyimide Resin 5 was used instead of Polyimide Resin 1. Table 1 shows the evaluation results of the cured film of the obtained polyimide composition.

(Comparative Example 6)
In the synthesis of the polyimide resin of Example 1, 20.39 g (63.7 mmol) of TFMB, 17.54 g (28.4 mmol) of TMPBP-TME as tetracarboxylic dianhydride, and 14.00 g (31.5 mmol) of 6FDA. ) and PMDA was changed to 0.74 g (3.40 mmol), acetic anhydride was changed to 26.00 g, and pyridine was changed to 1.01 g. Synthesize a polyimide resin in the same manner as in Example 1, A comparative polyimide resin 6 was obtained. ¹ H NMR measurement was performed on the obtained comparative polyimide resin 6, and it was confirmed that the signals derived from the carboxy proton and amide proton of the polyamic acid disappeared, that is, the complete imidization was confirmed.
A cured film of a polyimide composition was produced in the same manner as in Example 1, except that Comparative Polyimide Resin 6 was used instead of Polyimide Resin 1. Table 1 shows the evaluation results of the cured film of the obtained polyimide composition.

(Comparative Example 7)
In the synthesis of the polyimide resin of Example 1, 19.42 g (60.6 mmol) of TFMB, 30.08 g (48.6 mmol) of TMPBP-TME as a tetracarboxylic dianhydride, and 1.93 g (6.00 mmol) of BTDA ) and PMDA was changed to 1.18 g (5.40 mmol), acetic anhydride was changed to 24.77 g, and pyridine was changed to 0.96 g. Synthesize a polyimide resin in the same manner as in Example 1, A comparative polyimide resin 7 was obtained. The obtained comparative polyimide resin 7 was subjected to ¹ H NMR measurement, and it was confirmed that signals derived from carboxy protons and amide protons of polyamic acid disappeared, that is, complete imidization was confirmed.
A cured film of a polyimide composition was produced in the same manner as in Example 1, except that Comparative Polyimide Resin 7 was used instead of Polyimide Resin 1. Table 1 shows the evaluation results of the cured film of the obtained polyimide composition.

[Summary of Table 1]
All of the polyimide resins of Examples 1 to 4, which are the polyimide resins of the present invention, can form cured films having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low coefficient of linear thermal expansion. It was shown to be a polyimide resin with a fast film redissolution rate.
On the other hand, the polyimide resin of Comparative Example 1, which corresponds to the polyimide resin described in Patent Document 2, was a polyimide resin having a slow re-dissolving speed of the coating film.
The polyimide resin of Comparative Example 2, in which a part of the carboxylic acid dianhydride component of the polyimide resin of Comparative Example 1 is replaced with rigid PMDA, is, like Comparative Example 1, a polyimide resin having a slow rate of resolubility of the coating film. Met.
The polyimide resin of Comparative Example 3, in which the molecular weight of the polyimide resin of Comparative Example 2 was reduced to about 1/2, increased the resolubility rate of the coating film, but the mechanical properties of the cured film deteriorated. .
When the polyimide resin of Comparative Example 4, in which the molecular weight of the polyimide resin of Comparative Example 2 was reduced to about 1/5, formed a cured film, it became a very brittle film, indicating that a self-supporting film could not be formed.
The polyimide resin of Comparative Example 5, in which 6FDA was used in place of BTDA of Example 2, had greatly deteriorated mechanical properties of the cured film and had an inferior coefficient of linear thermal expansion.
The polyimide resin of Comparative Example 6, in which 6FDA was used instead of BTDA of Example 3, also deteriorated the mechanical properties of the cured film.
The polyimide resin of Comparative Example 7, which contained a large amount of TMPBP-TME, was a polyimide resin in which the re-dissolving rate of the coating film was still slow even though it contained the BTDA component.

(Example 5)
In Example 1, polyimide resin 4 was used instead of polyimide resin 1, and an epoxy compound having four epoxy groups in one molecule and a glycidylamine site (Maxieve M-100 (MXV-M100 ), N,N,N',N'-Tetraglycidyl-meta-xylylenediamine represented by the chemical formula (Ia), manufactured by Mitsubishi Gas Chemical) was added in an amount of 10 parts by mass with respect to 100 parts by mass of the polyimide resin. A polyimide composition was prepared in the same manner as in Example 1, and a cured film of the polyimide composition was produced.
Also, for adhesion evaluation, the substrates were changed to a silicon nitride substrate and a copper substrate, and a cured film of the polyimide composition was produced on each substrate in the same manner as in Example 1. Adhesion was evaluated without removing the cured film of the polyimide composition from each substrate.

(Example 6)
In Example 1, polyimide resin 4 was used instead of polyimide resin 1, and an epoxy compound having four epoxy groups in one molecule and a glycidylamine moiety (Sumiepoxy ELM-434 (ELM-434 ), N,N,N',N'-tetraglycidyl-4,4'-diaminodiphenylmethane represented by the chemical formula (Ib), manufactured by Sumitomo Chemical) was added in an amount of 10 parts by mass with respect to 100 parts by mass of the polyimide resin. Except for this, a polyimide composition was prepared in the same manner as in Example 1, and a cured film of the polyimide composition was produced.
Also, for adhesion evaluation, the substrates were changed to a silicon nitride substrate and a copper substrate, and a cured film of the polyimide composition was produced on each substrate in the same manner as in Example 1. Adhesion was evaluated without removing the cured film of the polyimide composition from each substrate.

(Example 7)
In Example 1, polyimide resin 4 was used in place of polyimide resin 1, and an epoxy compound (Sumiepoxy ELM-100 (ELM-100), N-[2-methyl-4-(oxiranylmethoxy)phenyl]-N-(oxiranylmethyl)oxiranemethanamine represented by the chemical formula (Ic), manufactured by Sumitomo Chemical) A polyimide composition was prepared and a cured film of the polyimide composition was produced in the same manner as in Example 1, except that 10 parts by mass was added to 100 parts by mass of the polyimide resin.
Also, for adhesion evaluation, the substrates were changed to a silicon nitride substrate and a copper substrate, and a cured film of the polyimide composition was produced on each substrate in the same manner as in Example 1. Adhesion was evaluated without removing the cured film of the polyimide composition from each substrate.
(Example 8)
In Example 1, polyimide resin 4 was used instead of polyimide resin 1, and an epoxy compound having four epoxy groups in one molecule and a glycidylamine site (Maxieve M-100 (MXV-M100 ), manufactured by Mitsubishi Gas Chemical Co., Ltd.) is 10 parts by mass per 100 parts by mass of the polyimide resin, and 3-glycidoxypropylmethyldimethoxysilane (KBM-402, manufactured by Shin-Etsu Chemical Co., Ltd.) is 1 per 100 parts by mass of the polyimide resin. A polyimide composition was prepared in the same manner as in Example 1, except that parts by mass were added, and a cured film of the polyimide composition was produced.
Also, for adhesion evaluation, the substrates were changed to a silicon nitride substrate and a copper substrate, and a cured film of the polyimide composition was produced on each substrate in the same manner as in Example 1. Adhesion was evaluated without removing the cured film of the polyimide composition from each substrate.

(Example 9)
In Example 1, polyimide resin 4 was used instead of polyimide resin 1, and an epoxy compound having four epoxy groups in one molecule and a glycidylamine site (Maxieve M-100 (MXV-M100 ), manufactured by Mitsubishi Gas Chemical) 10 parts by mass per 100 parts by mass of polyimide resin, and a silane coupling agent having the following structure (VD-5, manufactured by Shikoku Kasei) 1 part by mass per 100 parts by mass of polyimide resin A polyimide composition was prepared and a cured film of the polyimide composition was produced in the same manner as in Example 1, except for the addition.
Also, for adhesion evaluation, the substrates were changed to a silicon nitride substrate and a copper substrate, and a cured film of the polyimide composition was produced on each substrate in the same manner as in Example 1. Adhesion was evaluated without removing the cured film of the polyimide composition from each substrate.

(Example 10)
In Example 1, the solvent was changed from a 1:1 mixed solvent of DMAc and EA to cyclopentanone (CPN), polyimide resin 4 was used instead of polyimide resin 1, and 4 per molecule was added as an additive. 10 parts by mass of an epoxy compound having one epoxy group and a glycidylamine moiety (Maxieve M-100 (MXV-M100), manufactured by Mitsubishi Gas Chemical Co., Ltd.) per 100 parts by mass of the polyimide resin, and the silane coupling agent (VD-5, manufactured by Shikoku Kasei) except that 1 part by mass was added to 100 parts by mass of the polyimide resin, in the same manner as in Example 1 to prepare a polyimide composition and to produce a cured film of the polyimide composition. .
Also, for adhesion evaluation, the substrates were changed to a silicon nitride substrate and a copper substrate, and a cured film of the polyimide composition was produced on each substrate in the same manner as in Example 1. Adhesion was evaluated without removing the cured film of the polyimide composition from each substrate.

(Example 11)
In Example 10, instead of an epoxy compound having four epoxy groups in one molecule and a glycidylamine moiety (Maxieve M-100 (MXV-M100), manufactured by Mitsubishi Gas Chemical) as an additive, 1 A polyimide composition was prepared in the same manner as in Example 10, except that an epoxy compound having four epoxy groups in the molecule and a glycidylamine moiety (Sumiepoxy ELM-434 (ELM-434), manufactured by Sumitomo Chemical) was changed. A product was prepared to produce a cured film of the polyimide composition.
Also, for adhesion evaluation, the substrates were changed to a silicon nitride substrate and a copper substrate, and a cured film of the polyimide composition was produced on each substrate in the same manner as in Example 1. Adhesion was evaluated without removing the cured film of the polyimide composition from each substrate.

(Example 12)
In Example 10, instead of an epoxy compound having four epoxy groups in one molecule and a glycidylamine moiety (Maxieve M-100 (MXV-M100), manufactured by Mitsubishi Gas Chemical) as an additive, 1 The procedure was the same as in Example 10, except that an epoxy compound (Sumiepoxy ELM-100 (ELM-100) manufactured by Sumitomo Chemical Co., Ltd.) having three epoxy groups in the molecule and having a glycidylamine moiety and a glycidyl ether moiety was used. Then, a polyimide composition was prepared, and a cured film of the polyimide composition was produced.
Also, for adhesion evaluation, the substrates were changed to a silicon nitride substrate and a copper substrate, and a cured film of the polyimide composition was produced on each substrate in the same manner as in Example 1. Adhesion was evaluated without removing the cured film of the polyimide composition from each substrate.

[Summary of Table 2]
All of the polyimide compositions of Examples 4 to 12, which are the polyimide compositions of the present invention, can form cured films having a low dielectric constant, a low dielectric loss tangent, a high elastic modulus, and a low coefficient of linear thermal expansion. , was shown to be a polyimide resin with a fast re-dissolving rate of the coating film.
Further, in the polyimide composition of the present invention, having three or more epoxy groups in one molecule, and further containing an epoxy compound having a glycidylamine moiety, the polyimide compositions 5 to 12 of Embodiment A are inorganic It was shown that the adhesion to compounds (SiN) and metals (Cu) is improved.
In addition, like polyimide compositions 8 to 12, it was shown that when the polyimide composition of Embodiment A further contains a silane coupling agent, the adhesion to metal (Cu) is improved.

Claims (16)

40 mol% or more and less than 70 mol% of all structural units represented by the following formula (1), and more than 10 mol% and 60 mol% or less of all structural units represented by the following formula (2): including polyimide resin.

2. The polyimide resin according to claim 1, which has a weight average molecular weight of 150,000 or more as measured by gel permeation chromatography in terms of polystyrene. 3. The polyimide resin according to claim 1, further comprising a structural unit represented by the following formula (3) in an amount of 20 mol % or less of all structural units.

A polyimide composition comprising the polyimide resin according to any one of claims 1 to 3 and an organic solvent. 5. The polyimide composition according to claim 4, further comprising an epoxy compound having three or more epoxy groups in one molecule and having a glycidylamine moiety. The polyimide composition according to claim 5, further comprising a compound represented by the following general formula (A).

(In the formula (A), R ^a is a monovalent group containing at least one selected from the group consisting of a glycidyl group, a (meth)acryloyl group, an acid anhydride group, a hydroxy group, a triazine group, and an amino group. and R ^b and R ^c are each independently an alkyl group having 1 to 5 carbon atoms, n is an integer of 1 to 10, and m is an integer of 1 to 3.) A step of applying the polyimide composition according to any one of claims 4 to 6 on a substrate and drying to form a coating film;
A method for producing a cured film of a polyimide composition, comprising the step of forming a cured film by heating the coating film. The method for producing a cured film of a polyimide composition according to claim 7, wherein the coating film is heated at a temperature of 150°C or higher and 240°C or lower. A cured film of a polyimide composition obtained by curing the polyimide composition according to any one of claims 4 to 6. 10. The cured film of the polyimide composition according to claim 9, which has a dielectric constant of 3.60 or less and a dielectric loss tangent of 0.020 or less when measured at 10 GHz using a split cylinder resonator. The cured film of the polyimide composition according to claim 9 or 10, which has a linear thermal expansion coefficient of 30 ppm/°C or less at 100°C to 150°C. The cured film of the polyimide composition according to any one of claims 9 to 11, which has a tensile modulus of elasticity at 25°C of 4.5 GPa or more. A cured film of a polyimide composition obtained by curing the polyimide composition according to claim 5 or 6, wherein the adhesion to a silicon nitride substrate is a grid that does not peel off in a grid test method in accordance with JIS K 5400-8.5 A cured film of a polyimide composition having 80% or more of the total number of meshes. An insulating film produced using a cured film of the polyimide composition according to any one of claims 9 to 13. A protective film produced using a cured film of the polyimide composition according to any one of claims 9 to 13. An electronic component comprising the insulating film according to claim 14 or the protective film according to claim 15.

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