JP2003268305A - Coating varnish for insulating film and insulating film - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an insulating film excelling in all aspects of thermal, electrical, physical and mechanical characteristics for use in semiconductor field, particularly having thermal resistance and very low dielectric constant. <P>SOLUTION: This coating varnish comprises (1) one or more kinds of a polybenzoxazol precursor having repeating units expressed by general formula (F) and/or general formula (A), wherein n is an integer of 0 to 1,000 and m is an integer of 10 to 1,000, (2) an organic compound having 200 to 400°C thermal decomposition temperature and (3) an organic solvent capable of simultaneously dissolving or dispersing both of component (1) and component (2). This insulating film is produced by preparing the coating varnish and making it into a film. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a coating varnish for an insulating film and an insulating film. More specifically, thermal properties, electrical properties, mechanical properties, physical properties, in particular,
An insulating film coating varnish suitable for applications such as an interlayer insulating film for a semiconductor, a protective film, an interlayer insulating film of a multilayer circuit, a cover coat of a flexible copper clad board, a solder resist film, a liquid crystal alignment film, and the coating varnish. It relates to an insulating film.

[0002]

2. Description of the Related Art Conventionally, an oxide film produced by a chemical vapor deposition method or the like has been used as an insulating film, especially as an interlayer insulating film for semiconductors. However, an inorganic insulating film such as an oxide film has a high dielectric constant, and the application of an organic material as an insulating film is being studied for higher speed and higher performance. As an organic material for semiconductor use, a polyimide resin having excellent heat resistance, electrical characteristics, mechanical characteristics and the like is used. In recent years, as semiconductors have become more sophisticated and have higher performance, there has been a demand for significantly improved heat resistance, electrical characteristics, hygroscopicity, coefficient of thermal expansion, etc., and higher performance resins have become necessary. ing.

Under these circumstances, it has been attempted to apply a polybenzoxazole resin, which exhibits superior performance in water absorption and electric characteristics as compared with a polyimide resin, to an insulating material for semiconductors. The polybenzoxazole resin has excellent thermal properties, electrical properties, mechanical properties, and physical properties. For example, a polybenzoxazole resin composed of 4,4′-diamino-3,3′-dihydroxybiphenyl and terephthalic acid, There are polybenzoxazole resins made from 2,2'-bis (3-amino-4-hydroxyphenyl) hexafluoropropane and terephthalic acid. However, the demand for further lowering of the dielectric constant in recent years is strict,
Since it has become difficult to satisfy the required dielectric constant in a high-density film such as an organic resin, a method of reducing the dielectric constant by making a hole in the organic film is used. , Not only the relative dielectric constant, but also the mechanical and electrical characteristics,
In order to obtain an insulating film with fine pores while satisfying the water absorption resistance and heat resistance, the selection of the combination of resin and heat decomposable component is very limited, and the solubility and storage stability of the resin, etc. There is also a problem with the processability of the film, and the actual situation is that none of them satisfy all the properties.

[0004]

DISCLOSURE OF THE INVENTION The present invention provides a coating varnish for an insulating film, which is excellent in all of thermal properties, electrical properties, physical properties and mechanical properties and has good film processability.
In particular, in semiconductor applications, it is an object to provide an insulating film having a very low dielectric constant and high heat resistance.

[0005]

DISCLOSURE OF THE INVENTION The inventors of the present invention have made extensive studies in view of the above-mentioned conventional problems, and as a result, have found that a polybenzoxazole precursor having a specific structure has a thermal decomposition temperature of 200.degree. A film of polybenzoxazole prepared using a varnish prepared by adding an organic compound at 400 ° C.
The inventors have found that the objectives of the present invention can be satisfied, and have proceeded with further studies to complete the present invention.

That is, the present invention provides (1) a polybenzoxazole precursor having a repeating unit represented by the general formula (A) or the general formula (A) and the general formula (F), and (2) a thermal decomposition temperature , An organic compound having a temperature of 200 ° C. to 400 ° C., and (3) an organic solvent capable of simultaneously dissolving or dispersing the above component (1) and component (2), a coating for an insulating film. It is a varnish.

[Chemical 7] In the formula, the sum of m and n is 2 to 1000, and
It is an integer that satisfies the following formula. 0.05 ≦ (m / (m + n)) ≦ 1 Further, R _{1 to} R ₄ represent a hydrogen atom or a monovalent organic group, X is a tetravalent group represented by the formula (B), Y ₁ Is the formula (C)
The divalent group represented by and Y ₂ each represent a group selected from the divalent groups represented by the formula (D).

[Chemical 8] In formula (F), l is an integer of 1 to 1000 and R _{5 to} R ₆
Represents H or a monovalent organic group, X represents a tetravalent group represented by the formula (B), and Y ₂ represents a divalent group represented by the formula (D). The selected group is shown.

[Chemical 9]

[Chemical 10]

[Chemical 11]

[Chemical 12] In the formulas (B) and (D), X ₁ represents a group selected from the divalent groups represented by the formula (E), and in the structures of the formulas (B) to (E), on the benzene ring. The hydrogen atom is at least 1 selected from a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a fluorine atom, a trifluoromethyl group, and a phenyl group.
It may be substituted with individual groups.

Furthermore, the present invention is an insulating film, characterized by being made from the above-mentioned coating varnish.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The polybenzoxazole precursor represented by the general formula (A) used in the present invention has the above formula (B).
A bisaminophenol compound having a tetravalent group represented by, a cyano structure-containing carboxylic acid having a divalent group represented by formula (C), and a divalent group represented by formula (D). The polybenzoxazole precursor represented by the general formula (F) is a bisaminophenol compound having a tetravalent group represented by the formula (B) and a dicarboxylic acid represented by the formula (D). It can be obtained from a dicarboxylic acid having a valent group by a conventional acid chloride method, an activated ester method, a condensation reaction in the presence of a dehydration condensation agent such as polyphosphoric acid or dicyclohexylcarbodiimide, and the like.

In the polybenzoxazole precursor used in the present invention, the bisaminophenol compound having a tetravalent group represented by the formula (B) is 2,4-diaminoresorcinol, 4,6-diaminoresorcinol, 2 ,
2'-bis (3-amino-4-hydroxyphenyl) hexafluoropropane, 2,2'-bis (4-amino-3)
-Hydroxyphenyl) hexafluoropropane, 2,
2'-bis (3-amino-4-hydroxyphenyl) propane, 2,2'-bis (4-amino-3-hydroxyphenyl) propane, 3,3'-diamino-4,4'-dihydroxydiphenylsulfone, 4,4'-diamino-3,
3'-dihydroxydiphenyl sulfone, 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4'-diamino-3,3'-dihydroxybiphenyl, 9,9-bis- (4-((4- Amino-3-hydroxy) -phenoxy) -phenyl) -fluorene, 9,9-bis- (4
-((3-amino-4-hydroxy) -phenoxy)-
Phenyl) -fluorene, 3,3'-diamino-4,4'-
Dihydroxydiphenyl ether, 4,4'-diamino-
3,3'-dihydroxydiphenyl ether, 2,2'-bis (3-amino-4-hydroxy-2-trifluoromethyl) propane, 2,2'-bis (4-amino-3-hydroxy-2-trifluoro) Methyl) propane, 2,2'-
Bis (3-amino-4-hydroxy-6-trifluoromethyl) propane, 2,2'-bis (4-amino-3-hydroxy-6-trifluoromethyl) propane, 2,2 '
-Bis (3-amino-4-hydroxy-2-trifluoromethyl) hexafluoropropane, 2,2'-bis (4
-Amino-3-hydroxy-2-trifluoromethyl)
Hexafluoropropane, 2,2'-bis (3-amino-
4-hydroxy-5-trifluoromethyl) hexafluoropropane, 2,2'-bis (4-amino-3-hydroxy-5-trifluoromethyl) hexafluoropropane, 2,2'-bis (3-amino- 4-hydroxy-6-
Trifluoromethyl) hexafluoropropane, 2,2 '
-Bis (4-amino-3-hydroxy-6-trifluoromethyl) hexafluoropropane, 3,3'-diamino-4,4'-dihydroxy-2,2'-trifluoromethylbiphenyl, 4,4'- Diamino-3,3'-dihydroxy-2,2'-trifluoromethylbiphenyl, 3,3'-diamino-4,4'-dihydroxy-5,5'-trifluoromethylbiphenyl, 4,4'-diamino- 3,3'-dihydroxy-5,5'-trifluoromethylbiphenyl, 3,
3'-diamino-4,4'-dihydroxy-6,6'-trifluoromethylbiphenyl, 4,4'-diamino-3,3 '
-Dihydroxy-6,6'-trifluoromethylbiphenyl and the like can be mentioned, but the invention is not limited thereto. It is also possible to use two or more bisaminophenol compounds in combination.

In the polybenzoxazole precursor used in the present invention, examples of the cyano structure-containing carboxylic acid having a divalent group represented by the formula (C) include 3-cyanophthalic acid, 4-cyanophthalic acid and 2-cyanophthalic acid. Cyanoisophthalic acid,
4-cyanoisophthalic acid, 5-cyanoisophthalic acid, 2
-Cyanoterephthalic acid, 3-cyanoterephthalic acid, 2-
Cyano 1,5-naphthalenedicarboxylic acid, 3-cyano-
1,5-naphthalenedicarboxylic acid, 4-cyano-1,5-
Naphthalenedicarboxylic acid, 1-cyano-2,6-naphthalenedicarboxylic acid, 3-cyano-2,6-naphthalenedicarboxylic acid, 4-cyano-2,6-naphthalenedicarboxylic acid, 2-cyano-1,6-naphthalenedicarboxylic acid acid,
3-Cyano-1,6-naphthalenedicarboxylic acid, 4-cyano-1,6-naphthalenedicarboxylic acid, 5-cyano-
1,6-naphthalenedicarboxylic acid, 7-cyano-1,6-
Naphthalenedicarboxylic acid, 8-cyano-1,6-naphthalenedicarboxylic acid, 3,3'-dicyano-2,2'-biphenyldicarboxylic acid, 4,4'-dicyano-2,2'-biphenyldicarboxylic acid, 5, 5'-dicyano-2,2'-biphenyldicarboxylic acid, 6,6'-dicyano-2,2'-biphenyldicarboxylic acid, 2,2'-dicyano-3,3'-biphenyldicarboxylic acid, 4,4 '-Dicyano-3,3'-biphenyldicarboxylic acid, 5,5'-dicyano-3,3'-biphenyldicarboxylic acid, 6,6'-dicyano-3,3'-biphenyldicarboxylic acid, 2,2'-dicyano -4,4'-biphenyldicarboxylic acid, 3,3'-dicyano-4,4'-biphenyldicarboxylic acid, 2,2-bis (2-carboxy-3)
-Cyanophenyl) propane, 2,2-bis (2-carboxy-4-cyanophenyl) propane, 2,2-bis (2-carboxy-5-cyanophenyl) propane,
2,2-bis (2-carboxy-6-cyanophenyl)
Propane, 2,2-bis (3-carboxy-2-cyanophenyl) propane, 2,2-bis (3-carboxy-
4-cyanophenyl) propane, 2,2-bis (3-carboxy-5-cyanophenyl) propane, 2,2-bis (3-carboxy-6-cyanophenyl) propane,
2,2-bis (4-carboxy-2-cyanophenyl)
Propane, 2,2-bis (4-carboxy-3-cyanophenyl) propane, 2,2-bis (2-carboxy-
4-Cyanophenyl) hexafluoropropane, 2,2
-Bis (3-carboxy-5-cyanophenyl) hexafluoropropane, 2,2-bis (4-carboxy-2)
-Cyanophenyl) hexafluoropropane, 2,2-
Examples include bis (4-carboxy-2-cyanophenyl) hexafluoropropane, 4-cyano-1,3-dicarboxycyclopropane, 5-cyano-2,2-dicarboxycyclopropane, but are not limited thereto. Not something. It is also possible to use two or more cyano structure-containing carboxylic acid compounds in combination.

In the polybenzoxazole precursor used in the present invention, examples of the dicarboxylic acid having a divalent group represented by the formula (D) include isophthalic acid, terephthalic acid, 4,4'-biphenyldicarboxylic acid, 4,4'-biphenylenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 4,4'-sulfonyldibenzoic acid, 4,4'-oxybisbenzoic acid, 2,2
-Bis (4-carboxyphenyl) propane, 2,2-
Bis (4-carboxyphenyl) hexafluoropropane, 2,2'-bis (trifluoromethyl) -4,4'-biphenylenedicarboxylic acid, 3-fluoroisophthalic acid,
2-fluoroisophthalic acid, 2-fluoroterephthalic acid, 2,4,5,6-tetrafluoroisophthalic acid, 2,
Examples thereof include, but are not limited to, 3,5,6-tetrafluoroterephthalic acid and 5-trifluoromethylisophthalic acid. It is also possible to use two or more dicarboxylic acid compounds in combination.

In the method for producing the polybenzoxazole precursor used in the present invention, for example, in the acid chloride method, the acid chloride used is first treated with a dicarboxylic acid in the presence of a catalyst such as N, N-dimethylformamide. It can be obtained by reacting an excess amount of thionyl chloride at room temperature to 75 ° C., distilling off excess thionyl chloride by heating and reducing pressure, and recrystallizing the residue with a solvent such as hexane. Further, a cyano structure-containing carboxylic acid is also similarly
It can be the acid chloride. The cyano structure-containing acid chloride produced in this manner is usually used together with a bisaminophenol compound, usually N-methyl-2-pyrrolidone, N,
To obtain a polybenzoxazole precursor by dissolving it in a polar solvent such as N-dimethylacetamide and reacting it with an acid chloride obtained from dicarboxylic at room temperature to −30 ° C. in the presence of an acid acceptor such as pyridine. Can be done. The cyano structure contained in the polybenzoxazole skeleton represented by the general formula (A) used in the present invention reacts with each other to be trimerized to form a triazine ring. This ring formation reaction has been published in studies by S.kim and colleagues (Am.
chem.Soc.Polym.Prepr., 28 (1), 47 (1987)). This ring formation reaction proceeds by heat treatment even in the absence of a catalyst,
The reaction rate is increased by adding a transition metal such as zinc chloride as a catalyst. Further, a phenol compound may be used as a cocatalyst.

The heat-decomposable temperature used in the present invention is 200 ° C.
Examples of the organic compound at ˜400 ° C. include polyoxymethylene, polyoxyethylene, polyoxyisopropylene, polyoxymethylene-oxyethylene copolymer, polyoxymethylene-oxypropylene copolymer, polyoxyethylene-oxypropylene. Preferable examples include polyoxyalkylenes such as copolymers, polymethylmethacrylate, polystyrene, and poly α-methylstyrene. If necessary, a functional group such as a hydroxyl group, an amino group, a nitro group, a carboxy group, a cyano group, a cyano group, an acetylene group, or a methacryl group may be introduced at one end or both ends of the organic compound. . It is also possible to react these with a carboxy group, an amino group, a hydroxyl group at the terminal of the polybenzoxazole precursor, or a hydroxyl group in the main chain structure to be used as a copolymer. It is also possible to use two or more of these in combination.

The organic solvent capable of simultaneously dissolving or dispersing the polybenzoxazole precursor and the organic compound having a thermal decomposition temperature of 200 ° C. to 400 ° C. used in the present invention varies depending on the structure of the solute used. , For example, N-methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylacetamide, dimethyl sulfoxide, diethylene glycol dimethyl ether,
Diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, tetrahydrofuran, acetone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, propylene glycol monomethyl ether acetate, methyl lactate, ethyl lactate, butyl lactate, methyl- 1,3-
Butylene glycol acetate, 1,3-butylene glycol-3-monomethyl ether, methyl pyruvate,
Ethyl pyruvate, methyl-3-methoxypropionate and the like can be used alone or in combination of two or more.

The method for producing the coating varnish of the present invention is obtained by dissolving a polybenzoxazole precursor and an organic compound having a thermal decomposition temperature of 200 ° C. to 400 ° C. in an organic solvent or uniformly dispersing them. . Further, the proportion of the precursor (F) is 0 to 90 g, preferably 0 to 40 g, and more preferably 0 to 30 g with respect to 10 g of the precursor (A). The ratio of the organic compound to 0.01 g of the precursor (A) is preferably 0.01 to 20 g, more preferably 2 to 18 g, and further preferably 4 to 14 g. Regarding the solvent, the total amount of the precursor (A) and the precursor (F) is 10 g.
On the other hand, 5-200 g, preferably 10-150 g,
More desirably, the proportion is 15 to 100 g.

If necessary, various additives are added to the varnish such as a surfactant, a coupling agent typified by silane, a radical initiator which generates oxygen radicals or sulfur radicals by heating, and the like. It can be used as an insulating film, a protective film, an interlayer insulating film of a multi-layer circuit, a cover coat of a flexible copper clad board, a solder resist film, a liquid crystal alignment film and the like.

The polybenzoxazole resin precursor of the present invention can be heated to cause a condensation reaction and a crosslinking reaction to obtain a polybenzoxazole resin. The sum of m and n in the structure represented by the formula (A) is an integer of 2 to 1000 as described above, and preferably 5 to 100. Where 100
When it is 1 or more, for example, the viscosity of the varnish is high when dissolved in an organic solvent, and handling becomes very difficult, which is not practical. Further, m and n are integers within the range of the following formula, but 0.05 ≦ (m / (m + n)) ≦ 1 Preferably, the range of the following formula is preferable. 0.5 ≦ (m / (m + n)) ≦ 1 Here, when the condition of the following equation is satisfied, (m / (m + n)) <0.05 because the proportion of the crosslinking reaction is small, the effect of improving heat resistance is obtained. Becomes very small.

The polybenzoxazole precursor according to the present invention has at least one of R ₁ and R ₂ , R ₃ and R ₄ in the structure of the precursor represented by the general formula (A),
Further, when at least one of R ₅ and R ₆ of the precursor represented by the general formula (F) is H, by using together with a naphthoquinonediazide compound as a photosensitizer, a positive type photosensitive resin composition is obtained. As a product varnish, R ₁ and R ₂ , R ₃
When at least one of R ₄ and R ₄ , and at least one of R ₅ and R ₆ is a group having a photocrosslinkable group such as a methacryloyl group, a negative type photosensitive resin composition is prepared by using a photoinitiator. It can be used as a varnish.

In the method for producing an insulating film of the present invention, first, a coating varnish is applied to an appropriate support such as a silicone wafer or a ceramic substrate to form a coating film. As the coating method, spin coating using a spinner, spray coating using a spray coater, dipping, printing,
Roll coating etc. are mentioned. Then dry,
Although an insulating film can be formed by heat treatment, it is preferable that the polybenzoxazole precursor is converted into a crosslinked polybenzoxazole resin. Further, by selecting the dicarboxylic acid component, it is possible to form the film from the polybenzoxazole resin which is soluble in the solvent.

The polybenzoxazole precursor used in the present invention causes crosslinking by a cyclization reaction when heated, and an organic compound having a thermal decomposition temperature of 200 ° C. to 400 ° C. is heated at a temperature higher than this thermal decomposition temperature. By heating,
At this time, it is thermally decomposed and volatilized to form fine pores in the film of the polybenzoxazole resin. Therefore, a porous insulating film can be obtained by using the coating varnish according to the present invention.

[0021]

EXAMPLES The present invention will now be described in detail with reference to Examples, but the present invention is not limited to these.

Using the varnish obtained from the polymers synthesized in Examples and Comparative Examples and the insulating film produced from this varnish, the glass transition temperature, the thermal decomposition temperature, and the
Solubility and relative dielectric constant were measured. The measurement method of each characteristic is as follows, and the measurement results are summarized in Table 1. 1. Glass transition temperature Using DMS6100 manufactured by Seiko Instruments Inc., under nitrogen gas flow of 300 ml / min., Heating rate 3 ° C./mi
n, and the frequency was 1 Hz, and the peak top temperature of tan δ was taken as the glass transition temperature. 2. Thermal decomposition temperature Using TG / DTA220 manufactured by Seiko Instruments Inc., nitrogen gas flow rate of 200 ml / min.
It was measured under the condition of 0 ° C./min., And the temperature at which the weight loss reached 5% was defined as the thermal decomposition temperature. 3. 1 g of the soluble polybenzoxazole resin precursor and 3 g of N-methyl-2-pyrrolidone were precisely weighed in a glass sample container with a lid, and judged by the presence or absence of insoluble matter after stirring for 1 hour with a stir bar. 4. Based on the relative permittivity JIS-K6911, at a frequency of 100 KHz,
Hewlett Packard HP-4284A Pre
The capacitance of the insulating film was measured using a cision LCR meter, and the relative dielectric constant was calculated by the following calculation formula. Relative permittivity = (capacitance measurement value x insulating film thickness) / (vacuum permittivity x measurement area)

"Example 1" 2.2 under a nitrogen gas flow
-Bis (3-amino-4-hydroxyphenyl) hexafluoropropane 36.6 g (0.1 mol) was dissolved in 200 g of dried N-methyl-2-pyrrolidone, and pyridine 15.8 g (0.2 mol) was added. After that, -15 ℃
Cooled to 21.7 g of 5-cyanoisophthalic acid chloride
(0.095 mol) was added in small portions. After the addition was completed, the mixture was stirred at -15 ° C for 1 hour, then returned to room temperature and stirred at room temperature for 5 hours. Then, the reaction solution was dropped into 4 liters of distilled water in small droplets, and the precipitate was collected and dried to obtain a polybenzoxazole resin precursor. The number average molecular weight (Mn) of the obtained polybenzoxazole resin precursor was found to be 16500 when calculated in terms of polystyrene using GPC manufactured by Tosoh Corporation. 35 g of this polybenzoxazole precursor was dissolved in 200 g of N-methyl-2-pyrrolidone together with 15 g of polymethylmethacrylate (number average molecular weight: 50,000) and filtered through a Teflon (R) filter having a pore size of 0.2 μm to give a varnish. Obtained. Apply this varnish to the glass plate with a gap of 30
It was applied using a 0 μm doctor knife. After that, it is dried in an oven at 70 ° C for 1 hour, peeled off and the film thickness is 20μ.
A polybenzoxazole precursor film of m was obtained. Fix the film with a metal frame, 150 ℃ / 30 minutes, 250
C./30 minutes and 350.degree. C./30 minutes in this order were heated in a nitrogen atmosphere to obtain a polybenzoxazole resin insulating film. Various characteristics were evaluated using this insulating film.

"Example 2" In Example 1, 21.7 g (0.095 mol) of 5-cyanoisophthalic acid chloride
Instead of 5-cyanoterephthalic acid chloride 21.7
g (0.095 mol) was used, and 2,2-bis (3-amino-4-hydroxyphenyl) hexafluoropropane was replaced with 2,2-bis (4-amino-3) instead of 36.6 g (0.1 mol). -Hydroxyphenyl) hexafluoropropane except that 36.6 g (0.1 mol) was used.
A polybenzoxazole resin precursor was obtained in the same manner as in Example 1. The number average molecular weight (Mn) of this resin is
It was 16000 when calculated | required by polystyrene conversion using Tosoh Corp. GPC. Using this polybenzoxazole resin precursor, in the same manner as in Example 1,
An insulating film was obtained.

"Example 3" In Example 1, 21.7 g (0.095 mol) of 5-cyanoisophthalic acid chloride
In the same manner as in Example 1, except that 31.3 g (0.095 mol) of 5,5′-dicyano-3,3′-biphenyldicarboxylic acid chloride was used instead of the polybenzoxazole resin precursor. Obtained. The number average molecular weight (Mn) of this resin was 12,900 when calculated in terms of polystyrene using GPC manufactured by Tosoh Corporation. Example 1 using this polybenzoxazole resin precursor
An insulating film was obtained in the same manner as in.

"Example 4" In Example 1, 21.7 g (0.095 mol) of 5-cyanoisophthalic acid chloride
Instead of 5-cyanoisophthalic acid chloride 16.5
An insulating film was produced in the same manner as in Example 1 except that g (0.050 mol) and isophthalic acid chloride 9.1 g (0.045 mol) were used. The number average molecular weight (Mn) of the obtained polybenzoxazole precursor is
It was 18300 when calculated in terms of polystyrene using GPC manufactured by Tosoh Corporation.

"Example 5" In Example 1, 21.7 g (0.095 mol) of 5-cyanoisophthalic acid chloride
Instead of 19.3 g of isophthalic acid chloride (0.
10 g of a polybenzoxazole precursor (number average molecular weight 22000) prepared using 095 mol) and polymethylmethacrylate (number average molecular weight: 500
00) resin 10 g and the polybenzoxazole precursor prepared in Example 1 (number average molecular weight 1650).
An insulating film was prepared in the same manner as in Example 1 except that 20 g of 0) was dissolved in 200 g of N-methyl-2-pyrrolidone.

"Example 6" In Example 1, 21.7 g (0.095 mol) of 5-cyanoisophthalic acid chloride
Instead of 19.3 g of isophthalic acid chloride (0.
095 mol), 8 g of a polybenzoxazole precursor (number average molecular weight 22000), and
Poly α-methylstyrene (number average molecular weight: 40,000)
12 g of resin and the polybenzoxazole precursor (number average molecular weight 16000) 1 prepared in Example 2
An insulating film was prepared in the same manner as in Example 1 except that 5 g of the varnish was dissolved in 200 g of N-methyl-2-pyrrolidone.

"Comparative Example 1" In Example 1, 2,2-
Instead of 36.6 g (0.1 mol) of bis (3-amino-4-hydroxyphenyl) hexafluoropropane,
4,4'-diamino-3,3'-dihydroxybiphenyl 2
1.6 g (0.1 mol), 19.3 g (0.095 mol) of terephthaloyl chloride instead of 21.7 g (0.095 mol) of 5-cyanoisophthalic acid chloride
A polybenzoxazole resin precursor was obtained in the same manner as in Example 1 except that l) was used. Using this polybenzoxazole resin precursor, an attempt was made to produce a varnish in the same manner as in Example 1, but there were many insolubles in the varnish, and a film could not be produced. Therefore, the sample was prepared by treating the powdery polybenzoxazole precursor resin under the same heating conditions as in Example 1, and the glass transition temperature was MDSC (temperature cycle mode differential operation calorimeter: manufactured by TA Instruments). 2910MDS
According to C), the heating rate is 2 ° C / min, the temperature amplitude is ± 2 ° C / min,
The measurement was attempted under the condition of 30 ml / min of nitrogen gas, but no displacement point was observed. The thermal decomposition temperature was measured as in the case of the film.

"Comparative Example 2" In Example 1, 21.7 g (0.095 mol) of 5-cyanoisophthalic acid chloride was added.
Instead of 19.3 g of isophthalic acid chloride (0.09
A polybenzoxazole resin precursor was obtained in the same manner as in Example 1 except that 5 mol) was used. The number average molecular weight (Mn) of this resin was measured by GPC manufactured by Tosoh Corporation.
When calculated in terms of polystyrene using
Met. A film was prepared in the same manner as in Example 1 using this polybenzoxazole precursor resin.

[0031]

[Table 1]

As is clear from the results summarized in Table 1,
Each of the polybenzoxazole resin insulating films of Examples produced using the varnish of the present invention has a dielectric constant of 2.4 to
It had a low value of 2.6, high heat resistance, high solubility, and good characteristics. On the other hand, the polybenzoxazole resin precursor of Comparative Example 1 has a low solubility in N-methyl-2-pyrrolidone and cannot be processed into a film,
Further, in Comparative Example 2, a film was prepared by dissolving in N-methyl-2-pyrrolidone, but the glass transition temperature was low and the heat resistance was insufficient. In the examples according to the present invention, solubility in N-methyl-2-pyrrolidone was exhibited, a film could be produced, and heat resistance was extremely excellent, and the object of the present invention was sufficiently satisfied.

[0033]

According to the present invention, excellent thermal characteristics, electrical characteristics, mechanical characteristics, and physical characteristics can be achieved, and in particular, an insulating film having an extremely low dielectric constant can be formed and film processing can be performed. The coating varnish for insulating film that has good properties can be provided. The insulating film obtained from this is an interlayer insulating film for semiconductors, a protective film, an interlayer insulating film of a multilayer circuit, a cover coat of a flexible copper clad board, a solder resist film, a liquid crystal. It can be suitably used for applications such as alignment films.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H01L 21/312 H01L 21/312 AF term (reference) 4J038 CC032 CC082 CG142 DF022 DJ001 KA06 MA07 MA09 MA10 MA14 NA21 4J043 PA04 PA08 PA09 PA19 PC166 QB15 QB23 QB24 QB33 RA05 RA06 RA52 SA06 SA47 SA71 SA72 SB01 SB02 SB04 TA12 TA26 TA32 TA57 TA71 TB02 UA042 UA052 UA121 UA122 UA131 UA132 UA141 UA142 UA151 UA152 UA161 UA261 UA262 UB012 UB022 UB061 UB062 UB121 UB122 UB131 UB301 UB302 XA13 YA06 ZA12 ZA43 ZA46 ZB03 ZB11 ZB47 ZB50 ZB60 5F058 AA10 AC10 AF04 AG01 AH02 AH03

Claims (3)

[Claims] 1. A general formula (A) or a general formula (A)
And a polybenzoxazole precursor having a repeating unit represented by the general formula (F), (2) having a thermal decomposition temperature of 2
A coating varnish for an insulating film, comprising an organic compound at 00 ° C. to 400 ° C., and (3) an organic solvent capable of simultaneously dissolving or dispersing the above component (1) and component (2). . [Chemical 1] In the formula, the sum of m and n is 2 to 1000, and
It is an integer that satisfies the following formula. 0.05 ≦ (m / (m +
n)) ≦ 1 Further, R _{1 to} R ₄ represent a hydrogen atom or a monovalent organic group, X is a tetravalent group represented by the formula (B), and Y ₁ is represented by the formula (C). And a divalent group Y ₂ each represent a group selected from the divalent groups represented by the formula (D). [Chemical 2] In formula (F), l is an integer of 1 to 1000 and R _{5 to} R ₆
Represents H or a monovalent organic group, X represents a tetravalent group represented by the formula (B), and Y ₂ represents a group selected from a divalent group represented by the formula (D). Show. [Chemical 3] [Chemical 4] [Chemical 5] [Chemical 6] In the formulas (B) and (D), X ₁ represents a group selected from the divalent groups represented by the formula (E), and in the structures of the formulas (B) to (E), on the benzene ring. The hydrogen atom is at least 1 selected from a methyl group, an ethyl group, a propyl group, an isopropyl group, a butyl group, an isobutyl group, a t-butyl group, a fluorine atom, a trifluoromethyl group, and a phenyl group.
It may be substituted with individual groups. 2. The organic compound having a thermal decomposition temperature of 200 ° C. to 400 ° C. is at least one selected from polyoxyalkylene, polymethylmethacrylate, polystyrene, and poly α-methylstyrene. The described coating varnish. 3. An insulating film produced from the coating varnish according to claim 1 or 2.