JPH05132554A - Polyimide precursor, cured polyimide produced therefrom, and production thereof - Google Patents

Abstract

PURPOSE:To prepare a polyimide precursor which gives a cured polyimide having a high heat resistance, a low dielectric constant, a high glass transition point, etc., by copolymerizing a tetracarboxylic acid dianhydride with a specific diamine component in a specific solvent and adjusting the viscosity of the resulting varnish by heating. CONSTITUTION:A tetracarboxylic acid dianhydride of formula I (where R<1> is a group of formula II or III) is copolymerized with a diamine component consisting of 30-80% diamine of formula IV and 70-20% diamine of formula V (wherein R<2> is a group of formula VI, VII, or VIII; and R<3> is a divalent group having at least two arom. rings) in a polar aprotic solvent, and heated to adjust the viscosity of the resulting varnish, thus giving the objective polyimide precursor which comprises repeating units of formulas IX and X (wherein R<1>, R<2>, and R<3> are each as defined above), has a reduced viscosity (in N- methyl-2-pyrrolidone in a concn. of 0.1g/100ml at 25 deg.C) of 0.5dl/g of higher, and gives a cured polyimide having flexibility, high heat resistance and glass transition point, and low dielectric constant and thermal expansion coefficient.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a polyimide precursor and a polyimide cured product having excellent low dielectric constant, low thermal expansion coefficient and heat resistance, and a method for producing these.

[Conventional technology]

 Heretofore, polyimide has been known as a resin having excellent heat resistance. Polyimide is generally obtained by a method in which a diamine component and a tetracarboxylic dianhydride component are polymerized in an organic solvent to produce a polyamic acid, which is dehydrated and ring-closed.

Examples of these include, for example, (a) general formula (1) or general formula (2) A novel polyimide containing a structural unit represented by the formula (wherein R'represents a divalent hydrocarbon group) and a polyamic acid or polyamic acid ester which is a precursor thereof are known (Japanese Patent Laid-Open Publication No. Sho. 62-26 5327, JP-A-63-10629).

Also (b) general formula (3) Polyimides in which a repeating unit is represented by the formula (wherein R is a tetravalent aliphatic group or aromatic group and n is 1 or 2) are known (JP-A-57-114258, JP-A-57-114258). 57-188883, JP-A-60-250031, JP-A-60-212426).

Also (c) general formula (4) (Wherein, Y is _{-C (CH 3) 3 -,} - C (CF 3)
₃ -, -SO ₂ - it is. A polyimide having a repeating unit represented by () is known (JP-A-62-231935, JP-A-62-231936, JP-A-62-231937).

 (D) 2,2-bis (3,4-dicarboxyphenyl) propanoic acid dianhydride and 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanoic acid as polyimides having excellent low dielectric constant. A polyimide obtained from dihydrogenate and aromatic diamine such as 4,4′-bis (4-aminophenoxy) biphenyl and 4,4′-bis (4-amino-2-trifluoromethylphenoxy) biphenyl It is known (Japanese Patent Laid-Open No. 2-60934).

 In addition, (e) 2,2-bis (4-aminophenyl) hexafluoropropane and 2,2-bis (3-aminophenyl) hexafluoropropane with pyromellitic dianhydride and acid dianhydride having a diaryl nucleus Obtained from the mixed acid dianhydride (JP-A-2-67320), 2,2-bis (3,4-dicarboxyphenyl) hexafluoropropanoic acid dianhydride and 2,2-bis (4- A polyimide obtained from aminophenyl) hexafluoropropane and 2,2-bis (3-aminophenyl) hexafluoropropane (JP-A-2-86624) is known.

 However, the polyimides of (a), (b), (c), (d), and (e) above have high heat resistance, low dielectric constant, low coefficient of thermal expansion, and high mechanical properties (especially flexibility). , Various characteristics such as high glass transition temperature are not taken into consideration at the same time, and the polyimides of (d) and (e) above have a trifluoromethyl group, so they are alkaline solutions such as electroless plating solutions. Resistant to.

[Problems to be Solved by the Invention]

 The above (a), (b), (c), (d), (e) polyimides have high heat resistance, low dielectric constant, low coefficient of thermal expansion, high mechanical properties (especially flexibility), high Various characteristics such as glass transition temperature are not taken into consideration at the same time.

(A), (b), and (c) are excellent in high heat resistance, low thermal expansion coefficient, and high glass transition temperature, but have high dielectric constant and are not flexible. It is a phase in the polymer It has high heat resistance, high glass transition temperature, and low thermal expansion coefficient, but high dielectric constant because it contains the structural units. Further, since (d) and (e) contain -CF ₃ (trifluoromethyl group) and have an -O- bond, they have a low dielectric constant and excellent flexibility, but have low heat resistance and glass transition temperature. It is considered to have low resistance to alkaline liquor because of its low thermal expansion coefficient, high thermal expansion coefficient, and further due to —C (CF ₃ ) ₂ — bond, it is easily hydrolyzed by C—F bond to alkaline liquor.

 The inventors of the present invention have achieved various properties that cannot be achieved by these conventional techniques, namely, high heat resistance, low dielectric constant, low thermal expansion coefficient, high mechanical properties (especially flexibility), high glass transition temperature, The present invention has been achieved as a result of intensive studies aimed at finding a polyimide having various properties such as high alkali resistance.

[Means for Solving the Problems]

The present invention has the general formula, When the tetracarboxylic dianhydride component represented by is the total diamine component as 100, the diamine component and the aminosiloxane compound are Is a divalent group containing at least two aromatic rings. ) A diamine component represented by 3) and 3) if necessary, a general formula (In the formulas, R ⁴ and R ⁷ are hydrocarbon groups having 1 to 9 carbon atoms, R ⁵ is a hydrocarbon group having 1 to 3 carbon atoms, and R ⁶ is 1 to 1 carbon atoms containing an ether group as necessary. 5 a alkyl group or one or more groups Barre selected from trialkylsilyl ^group, R 8, ^{R 9} represents an alkyl group having 1 to 3 carbon atoms, an aryl group having 1 to 9 carbon atoms, n represents 0, 1 or 2, 1 is a positive integer.) The monoaminosiloxane compound or diaminosiloxane component represented by the formula (1) and the proportion of the monoaminosiloxane compound or siloxanediamine component used is 0.5 to 10 of the total amount of the diamine component. % In the aprotic polar solvent and further heated to adjust the viscosity of the varnish. A divalent group containing two or more aromatic rings, a polymer end which is R ^{3 as the case} requires, a polymer main chain is represented by the general formula, A hydrocarbon group containing a silicon atom represented by R ⁴ , wherein R ⁴ is a hydrocarbon group having 1 to 9 carbon atoms, R ⁵ is a hydrocarbon group having 1 to 3 carbon atoms, and R ⁶ is an ether group if necessary. And at least one group selected from the group consisting of alkyl groups having 1 to 5 carbon atoms and trialkylsilyl groups. n is 0, 1 or 2, and l is a positive integer. ), And the reduced viscosity of the polyimide precursor is at least 0.5 dl / g (solvent N-metal-2-pyrrolidone, concentration 0.1 g / 100 ml, temperature 25 ° C.) or more. A polyimide cured film obtained by heat-curing a polyimide precursor at a temperature of 100 ° C or higher has high heat resistance, low dielectric constant, low thermal expansion coefficient, high mechanical properties (especially flexibility), high glass transition temperature, It has been found to combine various characteristics such as.

 Hereinafter, the present invention will be described in detail.

 Examples of the tetracarboxylic acid dianhydride used in the present invention include paraterphenyl-3,3 ", 4,4" -tetracarboxylic acid dianhydride and meta-terphenyl-3,3 ", 4,4" -tetracarboxylic acid. An acid dianhydride can be used.

The diamine component used in the present invention is 4,4 "-diamino-paraterphenyl, 4,4" -diamino-para-quaterphenyl, 9,10-diaminoanthracene, and at least two or more aromatic compounds. Examples of other diamine components containing a ring include, for example, (Wherein X is -O -, - S -, - C (CH 3) 2 -, - CH 2 -, -C (CF 3) 2 -, - C (C 6 H 5) 2 -, - C ( C ₆ H ₅ ) (CH ₃ )-, —CO—), and at least one of these monomers can be used.

Other diamines may be used to adjust high heat resistance, low dielectric constant, low thermal expansion coefficient, high glass transition temperature, high mechanical strength, and flexibility. For example, Also, the general formula (In the formula, R ⁴ is a hydrocarbon group having 1 to 9 carbon atoms, R ⁵ is a hydrocarbon group having 1 to 3 carbon atoms, and R ⁶ is an alkyl group having 1 to 5 carbon atoms and optionally an ether group. Or a monoalkylsilane compound represented by the formula (1) or a combination of two or more groups selected from trialkylsilyl groups, wherein n is 0, 1 or 2, eg, 3-aminopropyltrimethylsilane, -Aminopropyldimethylmethoxysilane, 3-aminopropylmethyldimethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyldimethylethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltriethoxysilane, 3 -Aminopropyldimethylpropoxysilane, 3-aminopropylmethyldipropoxysilane, 3-aminopropoxy 3-Aminopropyldialkylalkoxysilane, 3-aminopropylalkyldialkoxysilane, 3-aminopropyldialkylalkoxysilane, 3-aminopropyldimethylbutoxysilane, 3-aminopropylmethyldibutoxysilane, 3-aminopropyltributoxysilane, etc. Aminopropyltrialkoxysilane, 3- (4-aminophenoxy) propyldialkylalkoxysilane, 3- (4-aminophenoxy) propylalkyldialkoxysilane, 3- (4-aminophenoxy) propyltrialkoxysilane, 3- (3-Aminophenoxy) propyldialkylalkoxysilane, 3- (3-aminophenoxy) propylalkyldialkoxysilane, 3- (3-aminophenoxy) propyltrialkoxysilane, 4 4-Aminobutyldialkylalkoxysilane, such as aminobutyldimethyldimethylsilane, 4-aminobutylmethyldiethoxysilane, and 4-aminobutyltriethoxysilane, 4-aminobutylalkyldialkoxysilane, 4-aminobutyltrialkoxysilane, 3-aminopropyl Tris (trimethylsilyloxy) silane, meta-aminophenyldimethylmethoxysilane, meta-aminophenylmethyldimethoxysilane, meta-aminophenyltrimethoxysilane, meta-aminophenyldimethylethoxysilane, meta-aminophenylmethyldiethoxysilane, meta-aminophenyltrietheo Xysilane, meta-aminophenyldimethylpropoxysilane, meta-aminophenylmethyldipropoxysilane, meta-amino Meta-aminophenyldialkoxysilanes such as phenyltripropoxysilane, meta-aminophenyldialkyldialkoxysilanes, meta-aminophenyltrialkoxysilanes, para-aminophenyldimethylmethoxysilanes, para-aminophenylmethyldimethoxysilanes, para-aminophenyltrioxysilanes. Para-aminophenyl such as methoxysilane, para-aminophenyldimethylethoxysilane, para-aminophenylmethyldiethoxysilane, para-aminophenyltriethoxysilane, para-aminophenyldimethylpropoxysilane, para-aminophenylmethyldipropoxysilane, para-aminophenyltripropoxysilane, etc. Dialkylalkoxysilane, para-aminophenylalkyldialkoxysilane , Para-aminophenyl trialkoxysilane, meta-aminobenzyl dimethylethoxysilane, meta-aminobenzyl methyldiethoxysilane, meta-aminobenzyl triethoxysilane, meta-aminobenzyl dimethylpropoxysilane, meta-aminobenzyl methyldipropoxysilane, meta-aminobenzyl Meta-aminobenzyldialkylalkoxysilane, meta-aminobenzylalkyldialkoxysilane, meta-aminobenzyltrialkoxysilane such as tripropoxysilane, meta-aminobenzyldimethylpropoxysilane, meta-aminobenzylmethyldipropoxysilane, meta-aminobenzyltripropoxysilane, etc. , Para-amino benzyl dimethyl propoxysilane, para-amino benzyl methyl dip Para-aminobenzyldialkylalkoxysilanes such as poxysilane, para-aminobenzyltripropoxysilane, para-aminobenzylalkyldialkoxysilane, para-aminobenzyltrialkoxysilane, para-aminophenethyl dimethylmethoxysilane, para-aminophenethylmethyldimethoxysilane, para-amino. Paranetaminophenethyldialkylalkoxysilanes such as phenethyltrimethoxysilane, para-aminophenethylalkyldialkoxysilanes, para-aminophenethyltrialkoxysilanes, or hydrogenated products of the above-mentioned meta- or para-form benzyl or henethyl compounds. Can be mentioned.

The siloxane diamine component used in the present invention has a general formula (In the formula, R ⁷ is selected from a divalent hydrocarbon group having 1 to 9 carbon atoms, R ⁸ and R ⁹ are selected from an alkyl group having 1 to 3 carbon atoms, and an aryl group having 1 to 9 carbon atoms. One or two or more groups, n is 0, 1 or 2, and l is a positive integer greater than or equal to 1.), for example, The above monoaminosiloxane compound or diaminesiloxane component is used in the range of use of the monoaminosiloxane component or diaminosiloxane component for the purpose of improving adhesiveness, when the total diamine component is 100, It is 0.5 to 10%, preferably 0.5 to 5% of the total amount of the diamine component. If the content of the monoaminosiloxane component is 0.5% or less, the effect of adhesiveness is small, and if it is 10% or more, the heat resistance and mechanical properties are adversely affected.

 The solvent used in producing the polyimide precursor and polyimide of the present invention is, for example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, dimethylsulfoxide, hexamethyl. Examples thereof include phosphoramide, tetramethylene sulfone, para-chlorophenol, para-bromophenol and the like, and at least one kind of them can be used.

 In carrying out the present invention, in the case of a polyimide precursor, first, the diamine component is dissolved in the aprotic polar solvent, and then terphenyl-3,3 ", 4,4" -tetracarboxylic dianhydride is added. In addition, stir for about 6 hours while maintaining the temperature at 0 to 30 ° C.

As a result, the reaction gradually progresses, the viscosity of the varnish increases, and the polyimide precursor is produced. Furthermore, the viscosity of the varnish is adjusted by stirring while maintaining the temperature at 50 to 80 ° C. However, when an aminosilane compound is further used as the diamine component, the viscosity of the varnish is adjusted by stirring for about 1 hour while maintaining the temperature at 0 to 30 ° C. and then at 50 to 80 ° C.

In addition, the polyimide cured product passing through the above polyimide precursor can be cured by heating at a temperature of 100 ° C. or higher to obtain the following general formulas (III) and (IV). Is a divalent group containing two aromatic rings and, if necessary, R ³ is a terminal of a polymer or a polymer of the general formula, respectively. A hydrocarbon group containing a silicon atom represented by, wherein R ⁴ and R ⁷ are hydrocarbon groups having 1 to 9 carbon atoms, a saturated alkyl group having 1 to 7 carbon atoms containing an ether bond, and R ⁵ is a carbon number. 1 to 3 hydrocarbon groups, R ⁶ is an alkyl group having 1 to 5 carbon atoms or a trialkylsilyl group optionally containing an ether bond, R ⁸ and R ⁹ are alkyl groups having 1 to 3 carbon atoms, carbon It is one or more groups selected from the aryl groups of the numbers 1 to 9.

n is 0, 1 or 2, and l is a positive integer of 1 or more. ) Consists of repeating units of the structure When the total amount of the diamine component and the aromatic diamine component represented by -R ^3-of (II) is 100, To 80 and the aromatic diamine component represented by —R ³ — is in the range of 70 to 20 and / or the aminosilane compound or siloxane diamine is used in an amount of 0.5 to 10% of the total amount of the diamine component. It is considered to be a cured product of polyimide in the range.

When the total amount of the aromatic diamine component represented by —R ³ — is 100, the composition ratio is represented by the formula (I). 80 to 30, preferably 80 to 50 from the viewpoint of process reliability when applied to a semiconductor device or the like, and other aromatic diamine component represented by -R ^3-of (II) is 20 ~ 70, and the point of process reliability when applied to semiconductor devices, etc. Then, the flexibility of the produced polyimide film is insufficient, and when it is 20 or less, the glass transition temperature Tg is low and the thermal expansion coefficient is high. Further, when the aromatic diamine component represented by -R ^3-of (II) is 50 or more, the glass transition temperature Tg is low and the coefficient of thermal expansion is high, and when it is 20 or less, the polyimide film produced has flexibility. Run short.

[Action]

 As described above, according to the present invention, by using para (or meta) -terphenyltracarboxylic dianhydride and a plurality of diamine components having different properties, a low dielectric constant, a low thermal expansion coefficient, and a high thermal expansion coefficient can be obtained. We were able to find polyimides and their precursors that have a high degree of heat resistance, high glass transition temperature, and high mechanical properties (flexibility). This is because the polyimide according to the present invention contains many linearly bonded aromatic rings and few imide rings that cause an increase in the dielectric constant. As a result, a low dielectric constant, low thermal expansion coefficient, It is considered that a polyimide with high heat resistance and high glass transition temperature was achieved at the same time. Further, by using an ether-type diamine as a part of the diamine component, the polyimide according to the present invention can also have high mechanical properties (flexibility).

〔Example〕

 Next, the present invention will be described with reference to Examples.Since the polyimide film according to the present invention is excellent in all of the evaluation characteristics, in order to compare its comprehensive evaluation with Comparative Examples, the evaluation criteria of characteristic values are as follows. Indicates.

Dielectric constant ε ≦ 2.7, Thermal decomposition temperature Td ≧ 520 ° C., Glass transition temperature Tg ≧ 380 ° C., Thermal expansion coefficient α ≦ 25 ppm / ° C., Tensile strength ≧ 15 kg / mm ² , Young's modulus ≦ 700 Kg / mm ² , Elongation ≧ 10%.

 In the examples and comparative examples described later, examples that meet these conditions were evaluated as good, and examples that did not meet the conditions were rated as bad.

Example 1 Bis [4- (4-aminophenoxy) phenyl] ether (BAPE√H ₂ N at room temperature under a nitrogen stream. 074 mol, 50% mol ratio in diamine component) and paradiaminoterphenyl (DATP≡N ₂ N 50% molar ratio in the diamine component) was added to 53.6 g (solid concentration 16%) of a 1: 1 mixed solvent of N, N-dimethylacetamide (DMAc) and N-methyl-2-pyrrolidone (NMP). It dissolved with stirring. Then paraterphenyl-3,3 ", 4,4" -tetracarboxylic dianhydride (TPDA) 5. 475 g (0.0148 mol) was dissolved in the above solution with stirring under a nitrogen stream. At this time, the temperature of the solution rose to around 30 ° C., and its viscosity became 150 poise. Further, this solution was heated at 60 to 70 ° C. for about 5 hours to adjust its viscosity to 50 poise to obtain a polyamic acid varnish.

 The polyamic acid varnish was spin-coated on a silicon wafer or a glass substrate, cured in a nitrogen stream at 200 ° C. for 30 minutes and then at 350 ° C. for 30 minutes and peeled off from the substrate. was gotten.

 Next, various properties of this film were evaluated by the following test methods. The results are shown in Table 1.

(1) Dielectric constant ε Within 24 hours after film formation, it was measured by LCHP meter, 4277A manufactured by YHP (Yokogawa Hulet Packard). Measurement conditions: humidity in the measurement room 60% or less, frequency 10 KHz, temperature 25 ° C., electrode is Al-Al or Cr-Al.

(2) Thermal decomposition temperature Td Using 50 mg of the above film, a high speed differential thermal analyzer TGD-5000 manufactured by ULVAC, Inc. was used to measure the temperature under a nitrogen stream at a temperature rising rate of 5 ° C./min. The temperature when the weight loss rate was 3% was defined as the thermal decomposition temperature Td.

(3) Glass transition temperature Tg The above film was used as a strip-shaped test piece of 5 mm x 25 mm, and its elongation rate was measured by a thermomechanical measuring device TM-30000 manufactured by ULVAC under a nitrogen stream. The temperature at which the elongation rate sharply increased was defined as the glass transition temperature Tg.

(4) Coefficient of thermal expansion α The above film was used as a strip test piece of 5 mm × 25 mm, and its elongation was measured under a nitrogen stream by a thermomechanical measuring device TM-30000 manufactured by ULVAC. I asked.

(5) Tensile Strength, Young's Modulus, and Elongation The film was used as a 5 mm × 45 mm strip-shaped test piece (film thickness: 8 μm), and the elongation and stress were determined using an Instron tensile tester.

Examples 2 to 9 Polyimide films were prepared in the same manner as in Example 1 using the components shown in Table 1, and various properties were evaluated in the same manner as in Example 1. The results are shown in Table 2. The polyimide film obtained had excellent flexibility and was a good film over all properties.

Comparative Examples 1 to 4 Polyimide films were prepared in the same manner as in Example 1 using the components shown in Table 2, and various properties were evaluated in the same manner as in Examples. The results are shown in Table 4. The obtained polyimide film was a good film with excellent flexibility, but its thermal expansion coefficient was large and its glass transition temperature was low, so there was a problem in terms of reliability when it was used for multilayer wiring structures, etc. It is believed that there is.

Comparative Example 5 A polyimide film was prepared in the same manner as in Example 1 using the components shown in Table 2, and various characteristics were evaluated in the same manner as in Example 1. The results are shown in Table 4. The obtained polyimide film was very poor in flexibility and could not be formed as a film. Therefore, it was not possible to measure various characteristic values such as thermal expansion coefficient, tensile strength and elongation.

Comparative Example 6 PIQ (registered trademark of Hitachi Chemical Co., Ltd.) is shown in Table 4 as another comparative example. Of the various characteristic values of PIQ, all the characteristic values other than tensile strength, Young's modulus, and elongation did not satisfy the evaluation criteria for the above characteristic values.

〔The invention's effect〕

 As described in the above Examples and Comparative Examples, the novel polyamic acid or polyimide according to the present invention has all the characteristics, especially low dielectric constant, low thermal expansion coefficient, in comparison with the conventionally known polyamic acid or polyimide. It is excellent in high heat resistance and expected to have high reliability, so it is useful in all industrial applications including multilayer wiring structures.

Table 1 Polymer composition Examples 1-9 Table 1 Polymer Configuration (continued) Examples 1-9 Table 2 Polymer composition Comparative Examples 1-5 Table 3 Various properties of polyimide film Examples 1 to 9 Table 3 Various properties of polyimide film Comparative Examples 1 to 6

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Tonobu Sato 2-1-1 Nishishinjuku, Shinjuku-ku, Tokyo Inside Hitachi Chemical Co., Ltd.

Claims (8)

[Claims] 1. A general formula A divalent group containing at least one aromatic ring) and having a constitutional ratio of formula (I) -R ³ in (II) - aromatic diamine represented by adult The diamine component represented is 30 to 80, the aromatic diamine component represented by —R ³ — is in the range of 70 to 20, and the reduced viscosity thereof is at least 0.5 dl / g (solvent N-methyl-2-pyrrolidone, concentration 0). 1 g / 100 ml, temperature 25 ° C.) or higher). 2. The general formula A divalent group containing one or more aromatic rings, R ⁴ has the general formula when its part is at the end of the polymer or when it is the main chain of the polymer. A hydrocarbon group containing a silicon atom represented by R ⁵ and R ⁸ are hydrocarbon groups having 1 to 9 carbon atoms, a saturated alkyne group having 1 to 7 carbon atoms containing an ether bond, and R ⁶ is 1 carbon atom To 3 hydrocarbon groups, R ⁷ is at least one group selected from the group consisting of alkyne groups having 1 to 5 carbon atoms and trialkylsilyl groups containing an ether bond, and R ⁹ and R ¹⁰ are carbon atoms. An alkyne group having 1 to 3 carbon atoms, an aryl group having 1 to 9 carbon atoms, n is 0, 1 or 2, and l is a positive integer. ) Is a repeating unit The total amount of the diamine component represented by, the aromatic diamine component represented by —R ³ — of (II) and the aromatic diamine component represented by —R ⁴ — of (III) is 10 Min components 30 to 80, -R ³ - aromatic diamine component represented by the, 70 to 20, -R ⁴ - is in the range aromatic diamine component is 0.5 to 10 represented by, its reduced viscosity At least 0. A polyimide precursor which is 5 dl / g (solvent N-methyl-2-pyrrolidone, concentration 0.1 g / 100 ml, temperature 25 ° C.) or higher. 3. In the general formula (II) according to claim 1 or 2,
The aromatic diamine represented by R ³ − is The polyimide precursor according to claim 1 or 2, which is one or more divalent groups selected from the structural formulas represented by: 4. The general formula A divalent group containing at least one aromatic ring) and a repeating unit represented by the formula (I). -R ³ in (II) - aromatic diamine represented by adult The diamine component represented is 30 to 80, the aromatic diamine component represented by -R ^3- is in the range of 70 to 20, and the reduced viscosity thereof is at least 0. Polyimide curing characterized in that a polyimide precursor having a concentration of 5 dl / g (solvent N-methyl-2-pyrrolidone, concentration 0.1 g / 100 ml, temperature 25 ° C.) or higher is heated and cured at a temperature of 100 ° C. or higher. object. 5. The general formula A divalent group containing one or more aromatic rings, R ⁴ has the general formula when its part is at the end of the polymer or when it is the main chain of the polymer. A hydrocarbon group containing a silicon atom represented by R ⁵ and R ⁸ are hydrocarbon groups having 1 to 9 carbon atoms, a saturated alkyne group having 1 to 7 carbon atoms containing an ether bond, and R ⁶ is 1 carbon atom To R 3 are hydrocarbon groups, R ⁷ is one or more groups selected from alkyl groups having 1 to 5 carbon atoms containing an ether bond or triaryl groups, and R ⁹ and R ¹⁰ are carbon groups. An alkyl group having a prime number of 1 to 3, an aryl group having a carbon number of 1 to 9, n is 0, 1 or 2, and l is a positive integer. ) Consists of repeating units, Diamine component is I and -R of the formula (II) 3 ^- -R of aromatic diamine component and an expression that I Table (III) 4 ^- the whole aromatic diamine component represented by 1 The amine component is in the range of 30 to 80, the aromatic diamine component represented by —R ³ — is 70 to 20, the aromatic diamine component represented by —R ⁴ — is in the range of 0.5 to 10, and its reduced viscosity is Is at least 0. Polyimide curing characterized in that a polyimide precursor having a concentration of 5 dl / g (solvent N-methyl-2-pyrrolidone, concentration 0.1 g / 100 ml, temperature 25 ° C) or higher is heated and cured at a temperature of 100 ° C or higher. object. 6. In the general formula (II) according to claims 4 and 5,
The aromatic diamine represented by R ³ − is The cured polyimide composition according to claim 4 or 5, which is one or more divalent groups selected from the structural formulas represented by: 7. A method for producing a polyimide precursor obtained from a diamine component and a tetracarboxylic dianhydride, wherein It ) When the total amount of the tetracarboxylic dianhydride component represented by It is a divalent group containing the above aromatic ring. ) A diamine component represented by 3) and 3) if necessary, a general formula, (In the formula, R ⁴ and R ⁷ are hydrocarbon groups having 1 to 9 carbon atoms, saturated alkyl groups having 1 to 7 carbon atoms containing an ether bond, R ⁵ is a hydrocarbon group having 1 to 3 carbon atoms, and R ⁶ is If necessary, at least one group selected from an alkyl group having 1 to 5 carbon atoms or a trialkylsilyl group containing an ether bond, R ⁸ and R ⁹ are an alkyl group having 1 to 3 carbon atoms, and a carbon number. 1 to 9 aryl groups, n is 0, 1 or 2. l is a positive integer. The proportion of the aminosilane compound or roxanediamine used is 0.5 of the total amount of the diamine component. A polyimide precursor characterized by polymerizing a diamine component in the range of 10 to 10 in an aprotic polar solvent at a temperature of 0 to 30 ° C, and further heating at 50 to 80 ° C with stirring to adjust the varnish viscosity. Manufacturing method. 8. The aromatic diamine represented by —R ³ — of 2) according to claim 7, 8. The method for producing a polyimide precursor according to claim 7, wherein the polyimide precursor is one or more divalent groups selected from the structural formulas represented by: