JP2001064388A - Polyimide, polyimide solution and method for forming polyimide film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a novel polyimide having highly flattening properties and other properties such as high heat resistance and high transparency, a polyimide solution containing the polyimide or its precursor and a solvent component, and to provide a method for forming a polyimide film having excellent flatness by using the polyimide solution. SOLUTION: The polyimide has a repeating unit represented by the formula (where (n) of a repeating unit is an integer of 3 to 1,000; (p) is 0 or 1; X is O, SO2, CO, C(CF3)2 or Si(R)2-O-Si(R)2; Y is SO2, S, C(CH3)2 or C(CF3)2; and R is an alkyl group). Further, the polyimide solution contains the polyimide or its precursor and a solvent component. In addition, the method for forming a polyimide film comprises coating the polyimide solution containing the polyimide having the repeating unit represented by the formula or its precursor and the solvent component on a wiring or an element pattern having a difference in level and curing the coated film to effect flattening of the formed polyimide film to a great extent independently of the element pattern.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polyimide which is used for surface protection and insulating film in a semiconductor device or a liquid crystal display device and has not only high heat resistance and high transparency but also excellent flatness and the like. And a polyimide solution containing the polyimide or a precursor thereof, and a method for forming a polyimide film using the solution.

[0002]

2. Description of the Related Art At the time of producing a multilayer wiring structure in a semiconductor device, S is formed on a substrate on which a circuit-shaped pattern wiring layer is formed by a method such as vacuum deposition or chemical vapor deposition.
A method of forming an interlayer insulating film made of iO2, SiN, or the like has been generally used. However, in such a case, when the insulating layer and the conductor layer are laminated, the step of the conductor layer becomes steeper as the number of layers increases, and the wiring layer at the step portion becomes extremely thin, which may cause a disconnection or a short circuit. There was a problem that it was easy.

In order to improve these, polyimides having high heat resistance have been proposed, and some of them have been used in semiconductor devices. However, general polyimides often have insufficient planarization properties, and it is necessary to increase the concentration of the polyamic acid solution, which is a precursor solution of the polyimide, in order to improve the planarization properties. Methods for ester oligomerization have been reported. However, due to the complexity of the structure of the semiconductor element, it has been impossible to uniformly flatten all the patterns from a fine groove pattern to a pattern having a very large and wide groove.

Also, in the liquid crystal display element, since the TFT element is formed on a glass substrate, the step structure of the element causes problems such as a decrease in contrast ratio due to generation of a domain around the TFT and occurrence of luminance unevenness due to a gap defect. In some cases. It is considered that it is necessary to flatten the step structure of the TFT element in order to increase the screen size and the definition of the liquid crystal display element in the future.

It has been reported that as a coating agent for such a liquid crystal display element, a polyimide comprising an aliphatic or alicyclic tetracarboxylic acid and a diamine compound or a dihydrazide compound can obtain high flatness.
However, when these are heated at 200 ° C. or more, the transparency may be greatly reduced, and it can be said that these are often insufficient in a field requiring transparency to visible light such as a liquid crystal display device.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances. That is, an object of the present invention is to provide a novel polyimide having properties such as high heat resistance and high transparency while having a high flattening property, a polyimide-based solution comprising the polyimide or a precursor thereof and a solvent, and the polyimide-based solution. An object of the present invention is to provide a method for forming a polyimide film having excellent flatness using a solution.

[0007]

Means for Solving the Problems According to the present invention, as a result of diligent studies to solve the above-mentioned problems, a polyimide comprising a specific biphenyl-based tetracarboxylic dianhydride and a specific diamine achieves the above object. Find out what you can do,
The present invention has been completed. That is, the present invention provides a compound represented by the general formula [I]:

[0008]

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Wherein the repeating unit n is from 3 to 1000
Wherein p is 0 or 1, X is -O-, -SO₂
-, -CO-, -C (CF₃)₂-, -Si (R)₂−
O-Si (R)₂-, Y is -SO₂-, -S-, -C
(CH₃)₂-, -C (CF₃) ₂-, R is an alkyl group
Represents )

A polyimide having a repeating unit represented by the formula: The present invention also relates to a polyimide solution containing a polyimide having a repeating unit represented by the above general formula [I] or a precursor thereof, and a solvent component. Further, the present invention applies a polyimide having a repeating unit represented by the general formula [I] or a polyimide-based solution containing a precursor thereof and a solvent component onto a wiring or an element pattern having a step, and further cures. The present invention relates to a method for forming a polyimide film, characterized in that a polyimide film formed by the method is highly planarized regardless of an element pattern.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.
The acid dianhydride component used for the polyimide represented by the general formula [I] of the present invention is 3,3'4,4'-biphenyltetracarboxylic acid, 3,3'4,4'-biphenylethertetracarboxylic acid 3,3′4,4′-biphenylsulfonetetracarboxylic acid, 3,3′4,4′-benzophenonetetracarboxylic acid, 2,2-bis (3,4-dicarboxyphenyl) propane, 1,1, 1,3,3,3-hexafluoro-2,2-bis (3,4dicarboxyphenyl) propane, bis (3,4dialboxyphenyl)
These are tetracarboxylic acids having a biphenyl structure such as tetramethyldisiloxa, dianhydrides thereof, and halogenated carboxylic acid diacids, and these can be used alone or in combination of two or more.

As the diamine compound, bis (4-
(3-aminophenoxy) phenyl) sulfone, bis (4- (4-aminophenoxy) phenyl) sulfone,
Bis (4- (3-aminophenoxy) phenyl) sulfide, bis (4- (4-aminophenoxy) phenyl)
Sulfide, 2,2-bis (4- (3-aminophenoxy) phenyl) propane, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 1,1,1,
3,3,3-hexafluoro-2,2-bis (4- (3
-Aminophenoxy) phenyl) propane, 1,1,
1,3,3,3-hexafluoro-2,2-bis (4-
Tetracyclic diamines such as (4-aminophenoxy) phenyl) propane.

In order to achieve the effects of the present invention, it is particularly desirable that the polyimide containing the above-mentioned combination be contained in an amount of at least 70 mol%, more preferably at least 80 mol%, in order to remarkably exhibit the effects of the invention.

As the remaining tetracarboxylic dianhydride component, there may be no problem in using a tetracarboxylic dianhydride and a derivative thereof which are usually used for the synthesis of polyimide.

Specific examples thereof include cyclobutanetetracarboxylic acid, 1,2,3,4-cyclopentanetetracarboxylic acid, 2,3,4,5-tetrahydrofurantetracarboxylic acid, 1,2,4,5-cyclohexane Alicyclic tetracarboxylic acids such as tetracarboxylic acid, 3,4-dicarboxy-1-cyclohexylsuccinic acid, 3,4-dicarboxy-1,2,3,4-tetrahydro-1-naphthalenesuccinic acid and the like; Dianhydrides and dicarboxylic acid diacid halides thereof.

Further, pyromellitic acid, 2, 3, 6, 7
-Naphthalenetetracarboxylic acid, 1,2,5,6-naphthalenetetracarboxylic acid, 1,4,5,8-naphthalenetetracarboxylic acid, 2,3,6,7-anthracenetetracarboxylic acid, 1,2,5 Tetracarboxylic acids, such as 2,6-anthracenetetracarboxylic acid, 2,3,4,5, -pyridinetetracarboxylic acid, 2,6-bis (3,4-dicarboxyphenyl) pyridine, and their dianhydrides And these dicarboxylic diacid halides,
Examples thereof include aliphatic tetracarboxylic acids such as 1,2,3,4-butanetetracarboxylic acid, and dianhydrides thereof, and dicarboxylic acid diacid halides thereof.

[0017] One or more of these tetracarboxylic acids and derivatives thereof may be used in combination. The remaining diamine component is a primary diamine usually used for the synthesis of polyimide, and is not particularly limited.

Specific examples thereof include p-phenylenediamine, m-phenylenediamine, 2,5-diaminotoluene, 2,6-diaminotoluene, 4,4-diaminobiphenyl and 3,3'-dimethyl-4. 4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-
Diaminobiphenyl, diaminodiphenylmethane, diaminodiphenylether, 2,2'-diaminodiphenylpropane, bis (3,5-diethyl-4-aminophenyl) methane, diaminodiphenylsulfone, diaminobenzophenone, diaminonaphthalene, 1,4-bis (4
-Aminophenoxy) benzene, 1,4-bis (4-aminophenyl) benzene, 9,10-bis (4-aminophenyl) anthracene, 1,3-bis (4-aminophenoxy) benzene, 4,4'- Bis (4-aminophenoxy) diphenyl sulfone, 2,2-bis [4- (4
-Aminophenoxy) phenyl] propane, 2,2'-
Trifluoromethyl-4,4'-diaminobiphenyl,
Aromatic diamines such as 4,4'-bis (4-diaminophenoxy) octafluorobiphenyl, alicyclic diamines such as bis (4-aminocyclohexyl) methane, bis (4-amino-3-methylcyclohexyl) methane and tetra Aliphatic diamines such as methylene diamine and hexamethylene diamine, and further,

[0019]

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(Wherein, n represents an integer of 1 to 10). Further, one or more of these diamines can be used in combination.

The method for obtaining the polyimide of the present invention can be specifically obtained by reacting and polymerizing the tetracarboxylic dianhydride and its derivative with the diamine. At this time, the ratio of the number of moles of tetracarboxylic dianhydride to the total number of moles of diamine and general diamine is preferably 0.8 to 1.2. As in the ordinary polycondensation reaction, the degree of polymerization of the produced polymer increases as the molar ratio approaches 1.
In this case, if the degree of polymerization is too small, the strength of the polyimide film becomes insufficient. On the other hand, if the degree of polymerization is too large, the workability during the formation of the polyimide film may deteriorate, or the fluidity for obtaining high flatness may not be obtained. Therefore, the degree of polymerization of the product in this reaction is 20,000 or less in terms of the number average molecular weight of the polyimide or its precursor. The preferred degree of polymerization is 1000 to 1000 in terms of number average molecular weight.
20,000 range, particularly preferably 5000-1500
It is in the range of 0.

An anhydride such as maleic anhydride, cyclohexanedicarboxylic anhydride, norbornene dicarboxylic anhydride or the like as an amine-terminated sealant, and a monoamine such as aniline as an acid dianhydride-end sealant may be used as a polyimide precursor. At the time of polymerization of the polymer or after completion of the polymerization, it may be added and reacted depending on the terminal concentration.

The method of reacting and polymerizing the tetracarboxylic dianhydride with the diamine is not particularly limited, but may be N-
Dissolve the diamine in a polar solvent such as methylpyrrolidone and add the tetracarboxylic dianhydride in the solution,
By reacting, a polyimide precursor (polyamic acid) is synthesized. The reaction temperature at that time is preferably from -20 ° C to 1
Any temperature between 50C, preferably between -5C and 100C can be selected.

Further, as a polymerization method of the polyamic acid, an ordinary solution method is suitable. Specific examples of the solvent used in the solution polymerization method include N, N-dimethylformamide, N, N
N-dimethylacetamide, N-methyl-2-pyrrolidone, N-methylcaprolactam, dimethylsulfoxide, tetramethylurea, pyridine, dimethylsulfone,
Hexamethylphosphoramide, butyl lactone and the like can be mentioned. These may be used alone or as a mixture. Further, even if the solvent does not dissolve the polyimide precursor, the solvent may be used in addition to the above solvent within a range where a uniform solution can be obtained.

The polyimide precursor solution of the present invention may be used as it is, or may be used as an organic solvent-soluble polyimide adjusted to an arbitrary imidation ratio. The method for obtaining the organic solvent-soluble polyimide is not particularly limited,
In general, the polyimide precursor can be obtained by dehydration and ring-closing imidization. The polyimide precursor obtained by reacting the tetracarboxylic dianhydride with the diamine can be directly imidized in the solution to obtain a solvent-soluble polyimide solution.

When a polyimide precursor is converted into polyimide in a solution, a method of dehydrating and cyclizing by heating is usually employed. The ring closure temperature due to this heat dehydration is 10
0 ° C to 350 ° C, preferably 100 ° C to 250 °
Any temperature of C can be selected. The imidation ratio can be controlled to an arbitrary value by selecting the temperature or time during the dehydration ring closure.

As another method of converting the polyimide precursor into polyimide, the ring can be chemically closed using a known dehydration ring closing catalyst. The imidation ratio can be controlled to an arbitrary value by selecting the temperature or time during the dehydration ring closure. The solvent to be dissolved is not particularly limited as long as it dissolves the obtained polyimide,
Examples are m-cresol, 2-pyrrolidone, N-
Examples include methylpyrrolidone, N-ethylpyrrolidone, N-vinylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, and γ-butyrolactone.

The obtained polyimide solution may be used as it is, or it may be used by precipitating and isolating in a poor solvent such as methanol or ethanol, and then dissolving the polyimide powder as a powder or re-dissolving the polyimide powder in an appropriate solvent. Can be done.

The solvent to be redissolved is not particularly limited as long as it can dissolve the obtained polyimide, and examples thereof include 2-pyrrolidone, N-methylpyrrolidone, and N-methylpyrrolidone.
Ethylpyrrolidone, N-vinylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide,
γ-butyrolactone and the like.

The above-mentioned polyimide precursor and solvent-soluble polyimide can be used as they are, but they may be used as a mixture with one or more kinds of polyimide precursors or solvent-soluble polyimide. The mixing ratio can be arbitrarily selected.

The solvent used in the polyimide-based solution of the present invention is not particularly limited as long as it can dissolve the polyimide or the polyimide precursor, and examples thereof include 2-pyrrolidone, N-methylpyrrolidone, and N-ethylpyrrolidone. , N-vinylpyrrolidone, N, N-dimethylacetamide, N, N-dimethylformamide, γ-butyrolactone, and the like.

Further, even a solvent which does not dissolve the polymer by itself can be used in addition to the above-mentioned solvents as long as the solubility is not impaired.

Examples thereof include ethyl cellosolve, butyl cellosolve, ethyl carbitol, butyl carbitol, ethyl carbitol acetate, ethylene glycol and the like.

For the purpose of further improving the adhesion between the polyimide film and the substrate, it is of course preferable to add an additive such as a coupling agent to the obtained polyimide solution. The polyimide film can be formed on the substrate by applying this solution to the substrate and evaporating the solvent. In this case, a temperature of 80 to 250 ° C. is usually sufficient.

[0035]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited thereto.
The physical properties of the obtained polyimide were evaluated using the following apparatus and method. 1) Molecular Weight Measurement The molecular weight in terms of polyethylene glycol was measured using an SSC-7200 GPC system manufactured by Senshu Kagaku. 2) Step thickness measurement Taristep (product name) manufactured by Rank Taylor Hobson
Was used. The step flattening property (%) is calculated from the values of A and B in FIG.

[0036]

It was determined from the formula: (1-B / A) × 100 (%). 3) Ultraviolet-visible spectrum UV-3100PC manufactured by Shimadzu Corporation was used. 4) Thermal decomposition temperature The thermal decomposition temperature was measured at a heating rate of 10 ° C./min using a thermogravimetric analyzer manufactured by Mac Science. Example 1

[0037]

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17.30 g (0.04 mol) of (4- (3-aminophenoxy) phenyl) sulfone and 87.27 g of N-methyl-2-pyrrolidone were charged into a flask equipped with a stirrer and a nitrogen inlet tube. Dissolved. To this solution, 11.79 g (0.038 mol) of 3,3'4,4'-biphenylethertetracarboxylic dianhydride was added at room temperature while paying attention to the rise in the solution temperature, and the mixture was stirred for 6 hours. (Polyamic acid) solution was obtained. To this solution, N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP) was added and diluted, and acetic anhydride and pyridine were added.
For 90 minutes. This solution was put into a 5-fold amount of methanol, followed by filtration and drying to obtain a white polyimide powder. The number average molecular weight of the obtained polyimide was 9,100, and the weight average molecular weight was 16,600.

This polyimide powder was dissolved in NMP to obtain a polyimide solution having a solid concentration of 25.0% by weight. This polyimide solution is divided into a line width / space width (L / S) =
On a step pattern of 1 to 50 μm (step thickness 1 μm),
Spin-coating was performed at a film thickness of 1.5 μm, and heat treatment was performed at 80 ° C. for 5 minutes and then at 300 ° C. for 1 hour to form a polyimide film. Measurement of the step flattening property of L / S = 10 μm of this coating film showed that the coating had a very high flattening property of 95%.

Further, on a quartz substrate under the same conditions,
When a 5 μm polyimide film was formed and the ultraviolet-visible spectrum was measured, the transmittance at a wavelength of 400 nm was 91%, indicating that the film had a high transmittance in the visible region.

Next, the polyimide film formed on the glass substrate under the same conditions was peeled from the substrate. The 5% weight loss onset temperature measured using this film was 500 ° C. or higher, indicating high heat resistance. Example 2

[0042]

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In a flask provided with a stirrer and a nitrogen introducing tube, 17.30 g (0.05 mol) of (4- (3-aminophenoxy) phenyl) sulfone and 85.44 g of NMP were added.
Was added and dissolved. 3,3'4,4 'at room temperature
-Biphenyltetracarboxylic dianhydride 11.18 g
(0.038 mol) while paying attention to the rise in solution temperature, and stirred for 6 hours to obtain a polyimide precursor (polyamic acid) solution. After NMP was added to this solution and diluted, acetic anhydride and pyridine were added and reacted at 50 ° C. for 90 minutes.
This solution was put into a 5-fold amount of methanol and then filtered and dried to obtain a white powder of polyimide. The number average molecular weight of the obtained polyimide was 10700, and the weight average molecular weight was 220.
00.

Further, the polyimide powder was dissolved in NMP to obtain a polyimide solution having a solid concentration of 20.0% by weight. This polyimide solution was spin-coated on a step pattern (step thickness 1 μm) of L / S = 1-50 μm,
A heat treatment was performed at 0 ° C. for 5 minutes and then at 300 ° C. for 1 hour to form a polyimide film. L / S of this coating film = 1
When the flatness of the step was measured at 0 μm, it was found that the flatness was as high as 97%.

Further, on a quartz substrate under the same conditions,
When a 5 μm polyimide film was formed and the ultraviolet-visible spectrum was measured, the transmittance was 82% at a wavelength of 400 nm, indicating that the film had high transmittance in the visible region.

Next, the polyimide film formed on the glass substrate under the same conditions was peeled from the substrate. The 5% weight loss onset temperature measured using this film was 500 ° C. or higher, indicating high heat resistance. Example 3

[0047]

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In a flask provided with a stirrer and a nitrogen inlet tube, 21.62 (0.05 mol) of (4- (3-aminophenoxy) phenyl) sulfone and NMP were charged and dissolved. At room temperature, 17.02 g of 3,3'4,4'-biphenylsulfonetetracarboxylic dianhydride (0.
048 mol) while paying attention to the rise in solution temperature.
After stirring for an hour, a polyimide precursor (polyamic acid) solution was obtained. After NMP was added to this solution and diluted, acetic anhydride and pyridine were added and reacted at 50 ° C. for 90 minutes. This solution was put into a 5-fold amount of methanol, and then filtered and dried to obtain a white powder of polyimide. The number average molecular weight of the obtained polyimide was 7,900, and the weight average molecular weight was 15,100.

Further, the polyimide powder was dissolved in NMP to obtain a polyimide solution having a solid content of 27.0% by weight. This polyimide solution was spin-coated on a step pattern (step thickness 1 μm) of L / S = 1-50 μm,
A heat treatment was performed at 0 ° C. for 5 minutes and then at 300 ° C. for 1 hour to form a polyimide film. L / S of this coating film = 1
When the flatness of the step was measured at 0 μm, it was found that the flatness was as high as 96%.

Further, on a quartz substrate under the same conditions,
When a 5 μm polyimide film was formed and the ultraviolet-visible spectrum was measured, the transmittance at a wavelength of 400 nm was 88%, indicating that the film had a high transmittance in the visible region.

Next, the polyimide film formed on the glass substrate under the same conditions was peeled from the substrate. The 5% weight loss onset temperature measured using this film is 490 ° C.,
It had high heat resistance. Example 4

[0052]

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17.30 g (0.04 mol) of (4- (3-aminophenoxy) phenyl) sulfone and N-methyl-2-pyrrolidone were charged and dissolved in a flask equipped with a stirrer and a nitrogen inlet tube. 1,1, at room temperature
1,3,3,3-hexafluoro-2,2-bis (3
16.88 g of 4-dicarboxyphenyl) propane
(0.038 mol) while paying attention to the rise in solution temperature, and stirred for 6 hours to obtain a polyimide precursor (polyamic acid) solution. N-methyl-2-pyrrolidone was added to this solution for dilution, and acetic anhydride and pyridine were added. After stirring at room temperature for 30 minutes, the mixture was heated to 50 ° C. and held at 50 ° C. for 90 minutes for imidization. After the imidization solution was allowed to cool to room temperature, it was poured into a 5-fold amount of methanol, and filtered and dried to obtain a white powder of polyimide. The number average molecular weight of the obtained polyimide was 12,800, and the weight average molecular weight was 26,000.

Further, the polyimide powder was dissolved in N-methyl-2-pyrrolidone to obtain a polyimide solution. This polyimide solution was spin-coated on a step pattern (step thickness 1 μm) with L / S = 1 to 50 μm, and heat-treated at 80 ° C. for 5 minutes and then at 300 ° C. for 1 hour to form a polyimide film. L / S of this coating film = 10 μm
Was measured, and found to have an extremely high leveling property of 96%.

Further, on a quartz substrate under the same conditions,
When a 5 μm polyimide film was formed and the ultraviolet-visible spectrum was measured, the transmittance was 95% at a wavelength of 400 nm, indicating that the film had a high transmittance in the visible region.

Next, the polyimide film formed on the glass substrate under the same conditions was peeled from the substrate. The 5% weight loss onset temperature measured using this film was 500 ° C. or higher, indicating high heat resistance. Example 5

[0057]

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In a flask provided with a stirrer and a nitrogen inlet tube, 21.62 g (0.05 mol) of (4- (3-aminophenoxy) phenyl) sulfone and 1.64 g (0.01 mol) of norbornene dicarboxylic anhydride were added. ) And N-methyl-2-pyrrolidone were charged and dissolved. To this solution, 17.91 g (0.05 mol) of 3,3 ', 4,4'-biphenylsulfonetetracarboxylic dianhydride was added at room temperature while paying attention to the rise of the solution temperature, and the mixture was stirred for 6 hours. A polyimide precursor (polyamic acid) solution having a concentration of 25.0% by weight was obtained. The number average molecular weight of the obtained polyimide precursor was 12,500 and the weight average molecular weight was 23300.

This polyamic acid solution was prepared by adding L / S = 1 to
A polyimide film was formed by spin coating on a 50 μm step pattern (step thickness 1 μm) and heat treatment at 80 ° C. for 5 minutes and then at 300 ° C. for 1 hour. When the flatness of the step of L / S = 10 μm of this coating film was measured, it was 9
It was found to have a very high flattening property of 5%.

Further, on a quartz substrate under the same conditions,
When a 5 μm polyimide film was formed and the ultraviolet-visible spectrum was measured, the transmittance at a wavelength of 400 nm was 91%, indicating that the film had a high transmittance in the visible region.

Next, the polyimide film formed on the glass substrate under the same conditions was peeled from the substrate. The 5% weight loss onset temperature measured using this film is 490 ° C.,
It had high heat resistance. Comparative Example 1

[0062]

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In a flask provided with a stirrer and a nitrogen inlet tube, 17.30 g (0.04 mol) of (4- (3-aminophenoxy) phenyl) sulfone and 74.25 g of NMP were added.
Was added and dissolved. 1,2,3,4-
7.45 g of cyclobutanetetracarboxylic dianhydride
(0.038 mol) while paying attention to the rise in solution temperature, and stirred for 6 hours to obtain a polyimide precursor (polyamic acid) solution. After NMP was added to this solution and diluted, acetic anhydride and pyridine were added and reacted at 50 ° C. for 90 minutes.
This solution was put into a 5-fold amount of methanol, and then filtered and dried to obtain a white powder of polyimide. The number average molecular weight of the obtained polyimide was 10100, and the weight average molecular weight was 221.
00.

Further, the polyimide powder was dissolved in NMP to obtain a polyimide solution having a solid concentration of 25.0% by weight. This polyimide solution was spin-coated on a step pattern (step thickness 1 μm) of L / S = 1-50 μm,
A heat treatment was performed at 0 ° C. for 5 minutes and then at 300 ° C. for 1 hour to form a polyimide film. L / S of this coating film = 1
When the flatness of the step above 0 μm was measured, it was 46%, indicating that sufficient flatness was not obtained. Comparative Example 2

[0065]

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In a flask provided with a stirrer and a nitrogen inlet tube, 17.30 g (0.04 mol) of (4- (3-aminophenoxy) phenyl) sulfone and 75.21 g of NMP were added.
Was added and dissolved. 1,2,3,4-
7.77 g of butanetetracarboxylic dianhydride (0.03 g)
9 mol) was added while paying attention to the rise in solution temperature, followed by stirring for 6 hours to obtain a polyimide precursor (polyamic acid) solution. After NMP was added to this solution and diluted, acetic anhydride and pyridine were added and reacted at 50 ° C. for 90 minutes. This solution is
After pouring into twice the volume of methanol, the mixture was separated by filtration and dried to obtain a polyimide white powder. The number average molecular weight of the obtained polyimide was 6,400, and the weight average molecular weight was 11,300.

Further, the polyimide powder was dissolved in NMP to obtain a polyimide solution having a solid content of 30.0% by weight.

This polyimide solution was treated with L / S = 1-50
A polyimide film was formed by spin coating on a μm step pattern (step thickness 1 μm) and heat treatment at 80 ° C. for 5 minutes and then at 300 ° C. for 1 hour. L of this coating
When the step flattening property of / S = 10 μm was measured, it was 94%.
It was found that it had a very high flattening property.

However, a 1.5 μm thick polyimide film was formed on a quartz substrate under the same conditions, and the ultraviolet-visible spectrum was measured.
%, And the transmittance in the visible region was greatly reduced. Comparative Example 3

[0070]

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In a flask equipped with a stirrer and a nitrogen inlet tube, 12.97 g (0.03 mol) of (4- (3-aminophenoxy) phenyl) sulfone and 134.3 g of NMP were added.
Was added and dissolved. 3,3'4,4 'at room temperature
-Biphenylsulfonetetracarboxylic dianhydride 1
0.73 g (0.03 mol) was added while paying attention to the rise in solution temperature, and the mixture was stirred for 6 hours to obtain a polyimide precursor (polyamic acid) solution. The number average molecular weight of the obtained polyamic acid was 21,300, and the weight average molecular weight was 40,300.

This polyimide solution was treated with L / S = 1-50
A polyimide film was formed by spin coating on a μm step pattern (step thickness 1 μm) and heat treatment at 80 ° C. for 5 minutes and then at 300 ° C. for 1 hour. L of this coating
/ S = 10 μm was measured to be 34%
And sufficient flatness could not be obtained. Comparative Example 4

[0073]

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In a flask provided with a stirrer and a nitrogen inlet tube, 1,4-bis (4-aminophenoxy) benzene
1.69 g (0.04 mol) and N-methyl-2-pyrrolidone were charged and dissolved. At room temperature, add 3,3 ',
4,4'-biphenyltetracarboxylic dianhydride 9.4
2 g (0.032 mol) was added while paying attention to the rise in solution temperature, and the mixture was stirred for 1 hour. Then, 2.63 g (0.016 mol) of norbornene dicarboxylic anhydride was added, and the mixture was stirred for 6 hours.
A polyimide precursor (polyamic acid) solution having a solid content of 25.0% by weight was obtained. The number average molecular weight of the obtained polyamic acid was 4450, and the weight average molecular weight was 8120.

This polyamic acid solution was prepared using L / S = 1 to 1
A polyimide film was formed by spin coating on a 50 μm step pattern (step thickness 1 μm) and heat treatment at 80 ° C. for 5 minutes and then at 300 ° C. for 1 hour. The flatness of the coating film at L / S = 10 μm was measured.
At 3%, sufficient flatness could not be obtained. Comparative Example 5

[0076]

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A flask equipped with a stirrer and a nitrogen inlet tube was charged with 4,4'-diaminodiphenyl ether (10.01).
g (0.05 mol) and N-methyl-2-pyrrolidone were charged and dissolved. 3,3 ', 4,4'-
Biphenyltetracarboxylic dianhydride 11.77 g
(0.04 mol) while paying attention to the rise in the solution temperature, and stirred for 1 hour, and then norbornene dicarboxylic anhydride.
28 g (0.02 mol) was added and the mixture was stirred for 6 hours to obtain a polyimide precursor (polyamic acid) solution having a solid content of 25.0% by weight. The number average molecular weight of the obtained polyamic acid was 4,360, and the weight average molecular weight was 7,160.

This polyamic acid solution was prepared using L / S = 1 to 1
A polyimide film was formed by spin coating on a 50 μm step pattern (step thickness 1 μm) and heat treatment at 80 ° C. for 5 minutes and then at 300 ° C. for 1 hour. When the flatness of the step of L / S = 10 μm of this coating film was measured, it was 6
At 7%, sufficient flatness could not be obtained.

[0079]

The polyimide of the present invention comprising a specific biphenyl-based dianhydride and a specific tetracyclic diamine or a polyimide-based solution containing a precursor thereof and a solvent component is placed on a wiring or an element pattern having a step. The polyimide film formed by coating and curing is excellent in flattening of steps, not only fine groove patterns with a width of several μm, but also groove patterns with a width of 10 μm or more, and has high heat resistance and high transparency. It has such characteristics as:

[Brief description of the drawings]

FIG. 1 shows a method for measuring flatness.

[Explanation of symbols]

 1 substrate 2 step pattern 3 polyimide film

Continued on the front page F term (reference) 4J002 CM041 EC027 EC047 ED027 EL066 EP016 ET016 EU026 EU046 EV206 EV216 EW156 FD206 FD207 GQ05 4J038 DJ021 GA02 GA12 GA13 GA15 JA20 JA26 JA57 JA64 JA70 JB13 JB24 JB27 JB09 JC11 MA12 NA12 4J043 PA02 PC015 PC016 PC145 PC146 QB15 QB23 QB26 QB31 RA35 SA06 SB01 SB03 TA14 TA22 TA26 TB01 TB03 UA022 UA032 UA052 UA121 UA122 UA131 UA132 UA151 UA251 UA 302 UB UB UB UA UA UA UA UA UA UA UB402 VA022 VA031 VA041 VA062 ZA12 ZA46 ZA52 ZB03 ZB11 ZB50 5F058 AA06 AA10 AB07 AC02 AD04 AF04 AG01

Claims (6)

[Claims] 1. A compound of the general formula [I](Wherein, the repeating unit n is an integer of 3 to 1000,
Wherein p is 0 or 1, X is -O-, -SO₂-, -CO
-, -C (CF₃)₂-, -Si (R)₂-O-Si
(R)₂-, Y is -SO₂-, -S-, -C (CH₃)
₂-, -C (CF₃) ₂-And R represent an alkyl group. )
Having a repeating unit represented by the formula:
Imide. 2. The polyimide according to claim 1, wherein the polyimide having a repeating unit represented by the general formula [I] has a number average molecular weight of 20,000 or less. 3. A compound of the general formula [I](Wherein, the repeating unit n is an integer of 3 to 1000,
Wherein p is 0 or 1, X is -O-, -SO₂-, -CO
-, -C (CF₃)₂-, -Si (R)₂-O-Si
(R)₂-, Y is -SO₂-, -S-, -C (CH₃)
₂-, -C (CF₃) ₂-And R represent an alkyl group. )
Polyimide having a repeating unit represented by or before
Polyimide characterized by containing a precursor and a solvent component
Mid-based solution. 4. A polyimide having a repeating unit represented by the general formula [I] or a precursor thereof having a number average molecular weight of 20
4. The polyimide solution according to claim 3, which is not more than 000. 5. A compound of the general formula [I](Wherein, the repeating unit n is an integer of 3 to 1000,
Wherein p is 0 or 1, X is -O-, -SO₂-, -CO
-, -C (CF₃)₂-, -Si (R)₂-O-Si
(R)₂-, Y is -SO₂-, -S-, -C (CH₃)
₂-, -C (CF₃) ₂-And R represent an alkyl group. )
Polyimide having a repeating unit represented by or
A polyimide solution containing a precursor and a solvent component,
Apply on wiring or element pattern with steps, and
The polyimide film formed by curing into
Form of polyimide film characterized by high flatness regardless of
Method. 6. A polyimide having a repeating unit represented by the general formula [I] or a precursor thereof having a number average molecular weight of 20.
The method for forming a polyimide film according to claim 5, wherein the thickness is not more than 000.