JPH04328161A - Fluororesin-containing polyamic acid composition, fluororesin-containing polyimide composition and film obtained from the same - Google Patents

Abstract

PURPOSE:To obtain a polyamic acid composition or a polyimide composition, capable of producing a polyimide film having a low dielectric constant by dispersing fluororesin powder in a specific fluorinated polyamic acid or fluorinated polyimide. CONSTITUTION:A composition is obtained by adding and homogeneously dispersing (B) fluororesin powder (e.g. tetrafluoroethylene resin) and, as necessary, a surfactant in (A) (A1) a polyamic acid solution, prepared by using a tetracarboxylic acid (derivative) and a diamine in which all monovalent elements such as alkyl groups or phenyl rings linked to carbon in the molecule are converted into fluorine or perfluoroalkyl groups as raw materials and consisting essentially of a polyamic acid having recurring units expressed by formula I [R1 is formulas II, III, etc., (Rf. is fluorine or perfluoroalkyl; X is O, CO, CO2, etc.); R2 is formulas TV, V, etc.] or (A2) a polyimide solution consisting essentially of a polyimide having recurring units expressed by formula VI. The resultant composition is hot cured to afford the polyimide film.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to a composition in which fluororesin powder is dispersed in a specific fluorinated polyamic acid or fluorinated polyimide, and a film obtained from the composition, and particularly relates to a film having a low dielectric constant. Regarding polyimide film.

0002

2. Description of the Related Art One of the most important performances currently required of communication components is high speed. Research into increasing the speed of semiconductor devices has been actively conducted, and many high-speed devices have been developed. Semiconductor elements are put into practical use only after being mounted on a wiring board, and even if the speed of the element itself is increased, if the signal propagation delay time on the wiring side is large, the overall speed cannot be increased. Generally, there is a relationship between the dielectric constant of the wiring board material and the signal propagation delay time as shown in the following equation (Equation 1).

[Equation 1] T=ε1/2 /C Here, T is the signal propagation delay time, ε is the dielectric constant, and C is the speed of light. Therefore, by lowering the dielectric constant of the wiring board material and wiring coating material, signal propagation delay time can be significantly shortened and high speeds can be achieved. For example, by using a polyimide wiring board instead of the ceramic wiring board that has been used up to now, wiring delay time can be significantly reduced. Furthermore, polytetrafluoroethylene has a low dielectric constant of 2.0, and by compounding it with various materials, materials with a low dielectric constant can be obtained. For example, a glass Teflon substrate has a low dielectric constant and relatively high heat resistance, so it is said to be a material used as a printed wiring board, but it has problems with machinability, dimensional stability, and adhesiveness. Further, JP-A-2-286743 discloses an aromatic polyimide solution composition in which fluororesin powder is uniformly dispersed in a polyimide solution in which the aromatic polyimide itself is dissolved in an organic polar solvent. It is said that by using this solution composition, a heat-resistant polyimide layer or polyimide film with a low dielectric constant can be formed on a printed wiring board.

0003

[Problems to be Solved by the Invention] However, the dielectric constant value of this material was still large at 2.6. It is necessary to further lower the dielectric constant. The present invention was made in view of the current situation, and its purpose is to provide a polyimide film with a low dielectric constant that can be applied to printed wiring boards, and a polyamic acid composition or polyimide composition necessary for producing the film. Our goal is to provide the following.

0004

[Means for Solving the Problems] To summarize the present invention, the first invention relates to a fluororesin-containing polyamic acid composition containing a specific polyamic acid and fluororesin powder as essential components. Then, the following general formula (Chemical formula 1):

[
Chemical Formula 1] [In the formula, R1 is the following formula (Chemical Formula 2):

Any group among the groups represented by [Chemical formula 2], R2 is represented by the following formula (
3):

[Chemical Formula 3] Wherein Rf is fluorine or a perfluoroalkyl group, and X is the following formula (Chemical Formula 4):

Contains a repeating unit represented by [Chemical formula 4] (wherein Rf' is a perfluoroalkylene group and n is a number from 1 to 10) It is characterized by having a polyamic acid component containing polyamic acid as a main component and fluororesin powder as essential components. The second invention of the present invention relates to a fluororesin-containing polyimide composition containing a specific polyimide and fluororesin powder as essential components, which has the following general formula (Chemical formula 5):

[Chemical formula 5] [In the formula, R1 and R2 have the same meanings as R1 and R2 in the general formula (Chemical formula 1)] A polyimide component mainly composed of polyimide containing a repeating unit represented by the formula, and a fluororesin powder. is characterized in that it is an essential component. A third invention of the present invention relates to a polyimide film, wherein the film is formed by heat curing the fluororesin-containing polyamic acid composition of the first invention or the fluororesin-containing polyimide composition of the second invention. It is characterized by being obtained by

[0005] As a result of our research into polyimides with low dielectric constants, the present inventors have developed a specific polyimide that has not been previously known. This polyimide is a completely new polyimide in which all monovalent elements bonded to carbon such as alkyl groups and phenyl rings are replaced with fluorine or perfluoroalkyl groups, and all carbon-fluorine bonds result in a low dielectric constant. was achieved, and the compatibility with the fluororesin was also improved.

[0006] In the tetracarboxylic acid or its derivative used in producing the perfluorinated polyimide of the present invention, all monovalent elements bonded to carbon atoms such as alkyl groups and phenyl rings in the molecule are replaced with fluorine or perfluorinated Any alkyl group may be used. Examples of tetracarboxylic acids and their derivatives such as acid anhydrides, acid chlorides, and esters include the following. Here, an example of a tetracarboxylic acid is 1
, 4-difluoropyromellitic acid, 1-trifluoromethyl-4-fluoropyromellitic acid, 1,4-di(trifluoromethyl)pyromellitic acid, 1,4-di(pentafluoroethyl)pyromellitic acid, hexa Fluoro-3
, 3',4,4'-biphenyltetracarboxylic acid, hexafluoro-3,3',4,4'-benzophenonetetracarboxylic acid, 2,2-bis(3,4-dicarboxytrifluorophenyl)hexafluoro Propane, 1,3
-bis(3,4-dicarboxytrifluorophenyl)
Examples include hexafluoropropane, 1,4-bis(3,4-dicarboxytrifluorophenoxy)tetrafluorobenzene, and hexafluoro-3,3' (or 4,4')-oxybisphthalic acid. Among them, 1,4-di(trifluoromethyl)pyromellitic dianhydride, 1,4-di(trifluoromethyl)pyromellitic dianhydride, which is a fluorine-containing dianhydride with a fluoroalkyl group introduced into the benzene ring of pyromellitic dianhydride, and 1,4-di( A method for producing pyromellitic dianhydride (pentafluoroethyl) is described in Japanese Patent Application No. 165056/1983.

Examples of diamines that can be used in the present invention include any diamine in which all monovalent elements bonded to carbon such as alkyl groups and phenyl rings are fluorine or perfluoroalkyl groups. It can be anything, 3
, 4,5,6-tetrafluoro-1,2-phenylenediamine, 2,4,5,6-tetrafluoro-1,3-phenylenediamine, 2,3,5,6-tetrafluoro-
1,4-phenylenediamine, 4,4'-diaminooctafluorobiphenyl, bis(2,3,5,6-tetrafluoro-4-aminophenyl)ether, bis(2,
Examples include 3,5,6-tetrafluoro-4-aminophenyl)sulfone, hexafluoro-2,2'-bis(trifluoromethyl)-4,4'-diaminobiphenyl, and the like.

[0008] The method for producing perfluorinated polyamic acid may be the same as the production conditions for ordinary polyamic acid, and generally N-methyl-2-pyrrolidone, N,N-dimethylacetamide, N, The reaction is carried out in a polar organic solvent such as N-dimethylformamide. In the present invention, not only the diamine and the tetracarboxylic acid component are used as a single compound, but also a plurality of diamine and tetracarboxylic acid components may be used as a mixture. In that case, the total number of moles of multiple or single diamines and the total number of moles of multiple or single tetracarboxylic acid components are made to be equal or approximately equal. In addition, when producing perfluorinated polyamic acid, by using acid components and diamine components that are not fully fluorinated, polyamic acid that is not partially fluorinated is produced, but if the proportion is not large, there is a particular problem. There isn't. In this way, a perfluorinated polyamic acid solution is obtained. When changing the solvent, the produced polyamic acid solution is dropped into a poor solvent, and the precipitated polyamic acid solid is dissolved in a preferred solvent. In addition, normal polyimide is insoluble in solvents, but many perfluorinated polyimides are soluble in solvents, so polyimide can be made from polyamic acid chemically or thermally and then dissolved in a solvent to obtain a polyimide solution. Can be done. The concentration of the polyamic acid solution or polyimide solution is determined by the thickness of the film obtained by heating and curing, but is preferably 5 to 40.
It is about wt%.

Examples of the fluororesin used in the present invention include tetrafluoroethylene resin, tetrafluoroethylene-ethylene copolymer resin, tetrafluoroethylene-hexafluoropropylene copolymer resin, and perfluoroalkoxy resin. , vinylidene fluoride resin, etc. In the composition of the present invention, the above-mentioned fluororesin is preferably blended in an amount of 1 to 100 parts by weight, particularly 2 to 50 parts by weight, per 100 parts by weight of the polyamic acid or polyimide.

Examples of solvents include amide solvents, cyclohexanone, lactones, phenol compounds, and mixed solvents thereof.

[0011] Surfactants may be used when preparing the compositions of the present invention. For example, N-ethyl-N-
Perfluorooctane sulfonamides such as 2-acetoxyethyl perfluorooctane sulfonamide, N-ethyl-N-2-hydroxyethyl perfluorooctane sulfonamide, trifluoromethanesulfonic acid ethyl ester, N-phenyltrifluoromethanesulfonamide, etc. Examples include trifluoromethane derivatives. The blending amount thereof is preferably 0.1 to 10 parts by weight per 100 parts by weight of polyamic acid or polyimide.

[0012] If necessary, various additives may be added to the composition of the present invention. For example, to improve adhesion, γ-methacryloxypropyltrimethoxysilane, γ-aminopropyltriethoxysilane,
γ-glycidoxypropyltrimethoxysilane, γ-(
An adhesion aid consisting of a silane compound such as 2-aminoethyl)aminopropylmethyldimethoxysilane can be blended.

The composition of the present invention can be prepared by adding fluororesin powder and, if necessary, a surfactant to a polyamic acid solution or polyimide solution and uniformly dispersing the mixture. In order to achieve uniform dispersion, mechanical dispersion using three rolls, a ball mill, a shaker, and dispersion using ultrasonic waves can be used.

[0014] In order to produce a film from the obtained composition, a conventional method for producing a polyimide film from a polyamic acid solution or a polyimide solution can be used. That is, it can be obtained by forming a thin film using a bar coater or a spin coater and curing it by heating.

[0015]

[Examples] The fluororesin-containing polyamic acid composition, the fluororesin-containing polyimide composition, and the film obtained from these of the present invention will be explained in detail below using Examples, but the present invention is limited to these Examples. It's not a thing.

Example 1 1,4-bis(3,4-dicarboxytrifluorophenoxy)tetrafluorobenzene dianhydride having the following structural formula (Chemical formula 6) was placed in an Erlenmeyer flask:

[Chemical formula 6] 11.64g (20.0mmol) and 2,4,5,6-
Tetrafluoro-1,3-phenylenediamine 3.60
2 g (20.0 mmol) and 86 g of N,N-dimethylacetamide (DMAc) were added. This solution was stirred at room temperature in a nitrogen atmosphere for 3 days to obtain a DMAc solution of polyamic acid. This solution was dropped into pure water, and the precipitated perfluorinated polyamic acid was separated and dried. A polyamic acid solution was prepared by dissolving 4 g of this solid perfluorinated polyamic acid in 12 g of cyclohexanone. After adding 0.4 g of tetrafluoroethylene resin (Daikin Corporation, Lublon) and 0.1 g of a surfactant (Sumitomo 3M, Florado 431) to this solution, the fluororesin was uniformly treated by ultrasonication. A fluororesin-containing polyamic acid solution was obtained. This composition was spin-coated onto an aluminum plate and heated to 160°C for 2 hours at 70°C under a nitrogen atmosphere.
Heat imidization was performed at 250°C for 1 hour and at 250°C for 1 hour to produce a polyimide-coated aluminum plate. Among these, the polyimide-coated aluminum plate was immersed in a 10% aqueous hydrochloric acid solution, and the aluminum plate was dissolved to obtain a fluororesin-containing polyimide film. When ten sheets of this polyimide film were prepared and their dielectric constants were measured, all of them were 2.5 or less at 1 kHz.

Example 2 The perfluorinated polyamic acid prepared in Example 1 was cast onto an aluminum plate, heated and cured under the same conditions as in Example 1, and then the aluminum plate was melted to obtain a perfluorinated polyimide film. . 2.0 g of this film was dissolved in 6 g of cyclohexanone to obtain a perfluorinated polyimide solution. To this solution, add 0.2
g and surfactant (manufactured by Sumitomo 3M, Florado 43)
1) 0.05 g was added and the added solution was subjected to ultrasonication to obtain a fluororesin-containing polyimide solution in which the fluororesin was uniformly dispersed. A fluororesin-containing polyimide film was obtained from this solution in the same manner as in Example 1. When ten sheets of this polyimide film were made and the dielectric constant was measured, it was found that 1
All were below 2.5 kHz.

Example 3 11.644 g (20.0 mmol) of 1,4-bis(3,4-dicarboxytrifluorophenoxy)tetrafluorobenzene dianhydride and the following structural formula (Chemical formula 7) were placed in an Erlenmeyer flask. Bis(2,3,5,6-tetrafluoro-4-aminophenyl)ether:

[Chemical formula 7] 6.883g (20.0mmol), and DMAc10
5 g was added, and a fluororesin-containing polyamic acid composition and a fluororesin-containing polyimide film were obtained in the same manner as in Example 1. When ten sheets of this polyimide film were prepared and their dielectric constants were measured, all of them were 2.5 or less at 1 kHz.

Example 4 11.644 g (20.0 mmol) of 1,4-bis(3,4-dicarboxytrifluorophenoxy)tetrafluorobenzene dianhydride and bis(2,3
, 6.883 g (20.0 mmol) of 5,6-tetrafluoro-4-aminophenyl)ether, and DMAc
After adding 105 g, a fluororesin-containing polyimide composition and a fluororesin-containing polyimide film were obtained in the same manner as in Example 2. When ten sheets of this polyimide film were made and the dielectric constant was measured, all of them were 2.5 at 1kHz.
It was below.

Comparative Example 1 The dielectric constant of the polyimide film disclosed in JP-A-2-286743 at 1 kHz is stated to be 2.6. The polyimide used here does not contain fluorine atoms.

[0021]

Effects of the Invention As explained above, the polyimide film of the present invention obtained from the fluororesin-containing polyamic acid or fluororesin-containing polyimide of the present invention has a lower dielectric constant than conventional ones, and is suitable for use in printed wiring boards, etc. If used for this purpose, signal wiring delay time can be shortened, contributing to higher speed electronic components.

Claims (3)

[Claims] [Claim 1] The following general formula (Formula 1): [Formula 1] [In the formula, R1 is any group represented by the following formula (Formula 2): [Formula 2], R2 is the following formula (
Chemical formula 3): Any of the groups represented by the following formula (Chemical formula 3), where Rf is fluorine or a perfluoroalkyl group, and X is the following formula (Chemical formula 4): [Chemical 4] (wherein, Rf' is a perfluoroalkylene group, and n is a number from 1 to 10). A fluororesin-containing polyamic acid composition characterized by having a polyamic acid component as a main component and a fluororesin powder as essential components. [Claim 2] A polyimide containing a repeating unit represented by the following general formula (Chemical formula 5): [Chemical formula 5] [In the formula, R1 and R2 have the same meanings as R1 and R2 in the general formula (Chemical formula 1)] 1. A fluororesin-containing polyimide composition comprising, as essential constituents, a polyimide component having as its main component and fluororesin powder. 3. A polyimide film, which is obtained by heating and curing the fluororesin-containing polyamic acid composition according to claim 1 or the fluororesin-containing polyimide composition according to claim 2. A film characterized by