JP2001311044A - Coating varnish for insulating film and insulating film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat-resistant insulating film which is excellent in all of thermal characteristics, electric characteristics, physical characteristics and mechanical characteristics in the field of semiconductors and especially has an extremely low dielectric constant. SOLUTION: This coating varnish characterized by comprising (1) one or more kinds of polybenzoxazole precursors each having repeating units represented by general formula (A) [(n) is an integer of 0 to 1,000; R1 to R4 are each H or a monovalent organic group; X is a group selected from groups represented by formula (B); Y is a group selected from groups represented by formula (C); Z1 and Z2 are each a group selected from groups represented by formula (D); as to formulae (B), (C) and (D), refer to the specification], (2) an organic compound having a thermal decomposition temperature of 200 to 400 deg.C, and (3) an organic solvent capable of simultaneously dissolving or dispersing the components (1) and (2), and the insulating film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interlayer insulating film for semiconductors, a protective film, an interlayer insulating film for a multilayer circuit, a cover coat for a flexible copper clad board, which is excellent in thermal, electrical, mechanical and physical properties. The present invention relates to a polybenzoxazole resin for an insulating film, which is suitable for applications such as a solder resist film and a liquid crystal alignment film.

[0002]

2. Description of the Related Art Conventionally, as an interlayer insulating film for semiconductors,
An oxide film produced by a chemical vapor method or the like is used. However, an inorganic insulating film such as an oxide film has a high dielectric constant, and the use of an organic material as the insulating film is being studied in order to achieve high speed and high performance. As an organic material for a semiconductor, a polyimide resin excellent in heat resistance, electric characteristics, mechanical characteristics, and the like is used. In recent years, as semiconductors have become more sophisticated and more sophisticated, there has been a demand for remarkable improvements in heat resistance, electrical properties, hygroscopicity, thermal expansion coefficient, and the like. ing.

[0003] Under such circumstances, attempts have been made to apply a polybenzoxazole resin, which exhibits better performance in terms of water absorption and electrical properties than a polyimide resin, as an insulating material for semiconductors. Polybenzoxazole resin is excellent in thermal properties, electrical properties, mechanical properties, physical properties, for example, polybenzoxazole resin composed of 4,4′-diamino-3,3′-dihydroxybiphenyl and terephthalic acid, There is a polybenzoxazole resin from 2,2'-bis (3-amino-4-hydroxyphenyl) hexafluoropropane and terephthalic acid. However, the demand for lowering the dielectric constant in recent years is severe,
With a high-density film such as an organic resin, it has become difficult to satisfy a required dielectric constant. Therefore, a method of significantly reducing the dielectric constant as an insulating film by making holes in an inorganic film such as an oxide film has been performed.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat-resistant insulating film having excellent thermal, electrical, physical and mechanical properties, and particularly having a very low dielectric constant, for semiconductor applications. Aim.

[0005]

Means for Solving the Problems The present inventors have conducted intensive 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 ° C. or less. A polybenzoxazole film prepared using a varnish, prepared by adding an organic compound at 400 ° C.,
The present inventors have found that the object of the present invention can be satisfied, and have further studied to complete the present invention.

That is, the present invention provides (1) one or more polybenzoxazole precursors having a repeating unit represented by the general formula (A), and (2) a thermal decomposition temperature of 2 or more.
And (3) an organic solvent capable of simultaneously dissolving or dispersing the above (1) and (2), and further comprising:
A combination of a polybenzoxazole precursor having a repeating unit represented by the general formula (F),
It is a coating varnish capable of producing an insulating film.

[0007]

Embedded image In the formula (A), n represents an integer of 0 to 1000. R _{1 to} R ₄
Is H or a monovalent organic group, X is a group selected from the formula (B), Y is a formula (C), and Z ₁ and Z ₂ are groups selected from the structures represented by the formula (D).

[0008]

Embedded image

[0009]

Embedded image In the formula, X ₁ represents a group selected from the structure represented by the formula (E). In these structures, a hydrogen atom on the benzene ring is a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-
Butyl group, isobutyl group, t-butyl group, fluorine atom,
It may be substituted with at least one group selected from the group consisting of a trifluoromethyl group and a trifluoroethyl group.

[0010]

Embedded image

[0011]

Embedded image

[0012]

Embedded image In the formula (F), m represents an integer of 10 to 1,000. R ₅ and R ₆ are H or a monovalent organic group, and X is a group represented by the formula (B):
Represents a group selected from the structure represented by the formula (C).

Still further, the present invention provides a polybenzoxazole insulating film, which is produced from the coating varnish.

[0014]

DETAILED DESCRIPTION OF THE INVENTION The polybenzoxazole precursor of the present invention comprises a bisaminophenol compound having the structure of the formula (B), a dicarboxylic acid having a structure of the formula (C), and a structure of the formula (D). Can be obtained from the acetylene-containing carboxylic acid having the formula (I) by a conventional acid chloride method, an activated ester method, or a condensation reaction in the presence of a dehydrating condensing agent such as polyphosphoric acid or dicyclohexylcarbodiimide.

The bisaminophenol compound having the structure of the formula (B) used in the present invention includes 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'-dihydroxydiphenylsulfone, 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-trifluoromethyl) propane, 2,2 ' -Bis (3-amino-4-hydroxy-5-
Trifluoromethyl) propane, 2,2′-bis (4-amino-3-hydroxy-5-trifluoromethyl) 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, but are not limited thereto. It is also possible to use two or more bisaminophenol compounds in combination.

Examples of dicarboxylic acids having the structure of the formula (C) include isophthalic acid, terephthalic acid, 4,4'-biphenylenedicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, , 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 include, but are not limited to, 3,5,6-tetrafluoroterephthalic acid, 5-trifluoromethylisophthalic acid, and the like. It is also possible to use two or more dicarboxylic acid compounds in combination.

Examples of acetylene-containing carboxylic acids having the structure of formula (D) include 2-ethynylbenzoic acid, 3-ethynylbenzoic acid, 4-ethynylbenzoic acid, 1,3-diethynylbenzoic acid, 2,4- Diethynylbenzoic acid, 1,3,
5-triethynylbenzoic acid, 2-ethynyl-1-naphthoic acid, 3-ethynyl-1-naphthoic acid, 4-ethynyl-
1-naphthoic acid, 5-ethynyl-1-naphthoic acid, 6-
Ethynyl-1-naphthoic acid, 7-ethynyl-1-naphthoic acid, 8-ethynyl-1-naphthoic acid, 2-ethynyl-
2-naphthoic acid, 3-ethynyl-2-naphthoic acid, 4-
Ethynyl-2-naphthoic acid, 5-ethynyl-2-naphthoic acid, 6-ethynyl-2-naphthoic acid, 7-ethynyl-
2-naphthoic acid, 8-ethynyl-2-naphthoic acid, 3,
5-diethynyl-1-naphthoic acid, 3,6-diethynyl-1-naphthoic acid, 3,7-diethynyl-1-naphthoic acid, 3,8-diethynyl-1-naphthoic acid, 4,5-diethynyl-1- Naphthoic acid, 4,6-diethynyl-1-naphthoic acid, 4,7-diethynyl-1-naphthoic acid, 4,8
-Diethynyl-1-naphthoic acid, 3,5-diethynyl-
2-naphthoic acid, 3,6-diethynyl-2-naphthoic acid, 3,7-diethynyl-2-naphthoic acid, 3,8-diethynyl-2-naphthoic acid, 4,5-diethynyl-2-naphthoic acid, 4 , 6-Diethynyl-2-naphthoic acid, 4,7
-Diethynyl-2-naphthoic acid, 4,8-diethynyl-
2-naphthoic acid, 3,5,6-triethynyl-1-naphthoic acid, 3,5,7-triethynyl-1-naphthoic acid,
5,8-triethynyl-1-naphthoic acid, 3,6,7-triethynyl-1-naphthoic acid, 4,5,7-triethynyl-2-naphthoic acid, 4,5,8-triethynyl-2-naphthoic acid, 4,6,8-triethynyl-2-naphthoic acid, 2
-Cyclopentyl carboxylic acid, 3-cyclopentyl carboxylic acid, 2-cyclohexyl carboxylic acid, 3-cyclohexyl carboxylic acid, 4-cyclohexyl carboxylic acid,
Examples include 2,4-cyclohexyldicarboxylic acid, 3,5-cyclohexyldicarboxylic acid, and the like, but are not limited thereto. It is also possible to use two or more acetylene-containing carboxylic acids in combination.

Examples of the organic compound having a thermal decomposition temperature of 200 ° C. to 400 ° C. include polyoxymethylene, polyoxyethylene, polyoxyisopropylene, polyoxymethylene-oxyethylene copolymer, and polyoxymethylene-oxypropylene. Copolymers, polyoxyalkylenes such as polyoxyethylene-oxypropylene copolymers,
Examples include polymethyl methacrylate and poly α-methylstyrene. If necessary, one having a functional group such as a hydroxyl group, an amino group, a nitro group, a carboxy group, a cyano group, or a methacryl group introduced at one or both ends can be used. Further, it can be used as a copolymer by reacting with a carboxy group, an amino group, a hydroxyl group at the terminal of the polybenzoxazole resin, or a hydroxyl group in the main chain structure. Further, these can be used in combination of two or more kinds.

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. differs depending on the structure of the solute to be used. Methyl-2-pyrrolidone, γ-butyrolactone, N, N-dimethylacetamide, dimethylsulfoxide, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, 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, etc.
They can be used alone or in combination of two or more.

In the method for producing a polybenzoxazole precursor according to the present invention, for example, in the acid chloride method, the acid chloride to be used is firstly reacted with a dicarboxylic acid in the presence of a catalyst such as N, N-dimethylformamide. An amount of thionyl chloride is reacted at room temperature to 75 ° C., excess thionyl chloride is distilled off by heating and reduced pressure, and the residue can be obtained by recrystallization with a solvent such as hexane. The thus prepared ethynylbenzoic acid chloride is usually combined with a bisaminophenol compound together with N-methyl-2-
Dissolved in a polar solvent such as pyrrolidone or N, N-dimethylacetamide, and in the presence of an acid acceptor such as pyridine, 2,2′-
By reacting bis (trifluoromethyl) -4,4'-biphenylenedicarboxylic acid chloride at room temperature to -30 ° C, a polybenzoxazole precursor can be obtained.

The polybenzoxazole resin of the present invention comprises
Crosslinking is caused by a cyclization condensation reaction by heating, and an organic compound having a thermal decomposition temperature of 200 ° C. to 400 ° C.
At this time, it is thermally decomposed and volatilized to form micropores in the polybenzoxazole resin film. Therefore, by using the coating varnish according to the present invention, a porous insulating film can be obtained.

A surfactant, a coupling agent represented by a silane group, a radical initiator for generating oxygen radicals or sulfur radicals by heating, and the like are added to the varnish as necessary. It can be used as an insulating film, 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 like.

The polybenzoxazole resin according to the present invention is characterized in that when at least one of R ₁ and R ₂ in the structure of the precursor represented by the general formula (A) is H,
By using together with a naphthoquinonediazide compound as a photosensitive agent, as a positive photosensitive resin composition,
When at least one of R ₁ and R ₂ is a group having a photocrosslinkable group such as a methacryloyl group, it can be used as a negative photosensitive resin composition by using a photoinitiator.

When using the polybenzoxazole precursor of the present invention, the varnish is applied to a suitable support, for example, a silicone wafer or a ceramic substrate. Examples of the coating method include spin coating using a spinner, spray coating using a spray coater, dipping, printing, and roll coating. Then, it is preferable to dry and heat-treat to convert to a cross-linked polybenzoxazole resin. Further, by selecting a dicarboxylic acid component, it can be used as a polybenzoxazole resin soluble in a solvent.

[0025]

EXAMPLES The present invention will be described below in detail with reference to examples, but the present invention is not limited thereto. Using the films prepared in Examples and Comparative Examples, the dielectric constant, heat resistance, and water absorption were measured for evaluating the characteristics. The measurement conditions for each characteristic were as follows, and the measurement results are summarized in Table 1.

Dielectric constant: Measurement frequency 1 MHz Heat resistance: Temperature was measured under a nitrogen gas flow at a temperature increase rate of 10 ° C./min at a weight loss of 5%. Water absorption: The water absorption after immersion at 23 ± 2 ° C. for 24 hours was measured.

Example 1 2,2-bis (3-amino-
4-hydroxyphenyl) hexafluoropropane 7
3.2 g (0.2 mol) was dissolved in 200 g of dried dimethylacetamide, and 39.6 g of pyridine (0.5 mol) was dissolved.
After addition of 1), a solution of 32.5 g (0.16 mol) of isophthalic chloride dissolved in 70 g of γ-butyrolactone is added dropwise at -15 ° C over 30 minutes under dry nitrogen. Subsequently, a solution obtained by dissolving 13.2 g (0.08 mol) of 4-ethynylbenzoic acid chloride in 30 g of γ-butyrolactone was added dropwise over 15 minutes. After completion of the dropwise addition, the mixture was returned to room temperature and stirred at room temperature for 5 hours. Thereafter, the reaction solution was dropped into 7 liters of distilled water, and the precipitate was collected and dried to obtain a polybenzoxazole precursor. Number average molecular weight (Mn) of the obtained polybenzoxazole precursor
Was 5600 in terms of polystyrene using GPC manufactured by Tosoh Corporation.

85 g of this polybenzoxazole precursor
With polymethyl methacrylate (number average molecular weight: 500
00) together with 15 g, and dissolved in N-methyl-2-pyrrolidone, and filtered through a Teflon (registered trademark) filter having a pore size of 0.2 μm to obtain a varnish. This varnish was applied on a glass plate using a doctor knife with a gap of 300 μm. Thereafter, the film was dried in an oven at 70 ° C. for 1 hour and peeled off to obtain a 20 μm-thick polybenzoxazole precursor film. The film is fixed with a metal frame,
30 minutes, 250 ° C / 30 minutes, 350 ° C / 30 minutes
Heating was performed under a nitrogen atmosphere to obtain a polybenzoxazole resin film. Various characteristics were evaluated using this film.

Example 2 In Example 1, 15.1 g of 3,5-ethynylbenzoic acid chloride was used instead of 13.2 g (0.08 mol) of 4-ethynylbenzoic acid chloride.
(0.08 mol), except that a film was produced in the same manner as in Example 1. The number average molecular weight (Mn) of the obtained polybenzoxazole precursor was determined to be 5,500 in terms of polystyrene using GPC manufactured by Tosoh Corporation.

Example 3 In Example 1, 13.2-g (0.08 mol) of 4-ethynylbenzoic acid chloride was replaced with 17.6-ethynyl-2-naphthoic acid chloride.
2 g (0.08 mol), and 2,2-bis (3
-Amino-4-hydroxyphenyl) hexafluoropropane 73.2 g (0.2 mol) instead of 4,4'-
6.2 g of biphenyl dicarboxylic acid chloride (0.02 mol
l) Except for using, a film was produced in the same manner as in Example 1. The number average molecular weight (Mn) of the obtained polybenzoxazole precursor was determined to be 5,300 in terms of polystyrene using GPC manufactured by Tosoh Corporation.

Example 4 42.5 g of the polybenzoxazole precursor obtained in Example 1 and 2,2′-bis (3-
Amino-4-hydroxyphenyl) hexafluoropropane and isophthalic chloride, prepared in the same manner as in Example 1, 42.5 g of a polybenzoxazole precursor (number average molecular weight 20,000) and polymethyl methacrylate (number average (Molecular weight: 50,000) 15 g of resin
Was prepared in the same manner as in Example 1 using a varnish in which 200 g of N-methyl-2-pyrrolidone was dissolved.

Comparative Example 1 In Example 1, 32.5 g (0.16 mol) of isophthalic acid chloride and 4-
13.2 g (0.08 mol) of ethynylbenzoic acid chloride
Instead of 38.6 g of isophthalic chloride (0.1
9 mol) to prepare a polybenzoxazole precursor, and a film was prepared in the same manner as in Example 1. When the number average molecular weight (Mn) of the obtained polybenzoxazole precursor was determined in terms of polystyrene using GPC manufactured by Tosoh Corporation, it was 10,000.

Comparative Example 2 In Example 1, 32.5 g (0.16 mol) of isophthalic chloride and 4-
13.2 g (0.08 mol) of ethynylbenzoic acid chloride
Instead of 5.6 g (0.20 mol) of 4,4′-biphenyldicarboxylic acid chloride, a polybenzoxazole precursor was prepared, and a film was prepared in the same manner as in Example 1. The number average molecular weight (Mn) of the polybenzoxazole precursor obtained here was determined by using Tosoh Corporation GP
When calculated in terms of polystyrene using C, 1200
It was 0.

[0034]

[Table 1]

As is clear from the results summarized in Table 1,
The polybenzoxazole resins of Examples prepared using the polybenzoxazole precursor of the present invention have low dielectric constants of 2.4 to 2.5, and furthermore have high heat resistance and low water absorption. Characteristics. On the contrary,
Although the comparative example is a polybenzoxazole resin, it does not have the repeating unit represented by the general formula (A) of the present invention.
No values below were obtained.

[0036]

The polybenzoxazole resin of the present invention can achieve excellent thermal, electrical, mechanical, and physical properties, and in particular, can form an insulating film having an extremely low dielectric constant. It can be suitably used for applications such as interlayer insulating films for semiconductors, protective films, interlayer insulating films for multilayer circuits, cover coats for flexible copper clad boards, solder resist films, and liquid crystal alignment films.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01L 21/312 H01L 21/312 AD 23/29 23/30 R 23/31 DF Term (Reference) 4J038 CC082 CG142 DF012 DJ001 JA27 JA57 JA61 JB14 JB27 JC11 KA06 LA03 MA06 MA09 NA11 NA14 NA21 PA18 PA19 PB09 PC08 4J043 PA02 PA04 PA19 PB05 QB15 QB23 QB34 RA52 SA06 SA43 SA54 SA71 SB01 SB02 TA11 TA12 TA47 TA72 UA 712 TA04 UA131 UA132 UA151 UA221 UA231 UA262 UB021 UB022 UB061 UB062 UB121 UB122 UB131 UB301 UB302 UB401 UB402 VA012 VA021 VA022 VA031 VA042 VA051 VA052 VA082 WA01 WA05 WA13 Z16 AA01 CA10 EC01 EC05 EC07 5F058 AA10 AC07 AC10 AF04 AF06 AG01 AH02 AH03 AH10

Claims (4)

[Claims] (1) one or more polybenzoxazole precursors having a repeating unit represented by the general formula (A), and (2) a thermal decomposition temperature of 200 ° C to 400 ° C.
(C) an organic compound, and (3) the above (1) and (2)
A varnish for coating capable of forming an insulating film, comprising an organic solvent capable of simultaneously dissolving or dispersing the same. Embedded image In the formula (A), n represents an integer of 0 to 1000. R _{1 to} R ₄
Is H or a monovalent organic group, X is a group selected from the formula (B), Y is a formula (C), and Z ₁ and Z ₂ are groups selected from the structures represented by the formula (D). Embedded image Embedded image In the formula, X ₁ represents a group selected from the structure represented by the formula (E). In these structures, a hydrogen atom on the benzene ring is a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-
Butyl group, isobutyl group, t-butyl group, fluorine atom,
It may be substituted with at least one group selected from the group consisting of a trifluoromethyl group and a trifluoroethyl group. Embedded image Embedded image (1) one or more polybenzoxazole precursors having a repeating unit represented by the general formula (A), and (2) having a repeating unit represented by the general formula (F). Polybenzoxazole precursor,
(3) An organic compound having a thermal decomposition temperature of 200 ° C. to 400 ° C. and (4) an organic solvent capable of simultaneously dissolving or dispersing the above (1) to (3). Varnish for coating, capable of producing insulating film. Embedded image In the formula (A), n represents an integer of 0 to 1000. R _{1 to} R ₄
Is H or a monovalent organic group, X is a group selected from the formula (B), Y is a formula (C), and Z ₁ and Z ₂ are groups selected from the structures represented by the formula (D). Embedded image Embedded image In the formula, X ₁ represents a group selected from the structure represented by the formula (E). In these structures, a hydrogen atom on the benzene ring is a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-
Butyl group, isobutyl group, t-butyl group, fluorine atom,
It may be substituted with at least one group selected from the group consisting of a trifluoromethyl group and a trifluoroethyl group. Embedded image Embedded image Embedded image In the formula (F), m represents an integer of 10 to 1,000. R ₅ and R ₆ are H or a monovalent organic group, and X is a group represented by the formula (B):
Represents a group selected from the structure represented by the formula (C). 3. The organic compound having a thermal decomposition temperature of 200 ° C. to 400 ° C. is at least one selected from the group consisting of polyoxyalkylene, polymethyl methacrylate, and poly α-methylstyrene. Item 3. The coating varnish according to Item 1 or 2. 4. A polybenzoxazole insulating film produced from the coating varnish according to claim 1. Description: