JP2001098160A - Resin composition for insulating material and insulating material using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a resin composition for an insulating material and an insulating material having an excellent heat characteristic and electrical characteristic in a semiconductor use. SOLUTION: The present invention provides the resin composition for the insulating material comprising a component (A) having a hollow structure in which the free volume is 0.001-1,000 nm3 such as a fullerene or a carbon nanotube and a heat resistant resin or its precursor (B) as an essential component, and the insulating material using the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an insulating material, and more particularly, to a resin composition for an insulating material having excellent characteristics for use in electric / electronic devices and semiconductor devices, and an insulating material using the same. It is about.

[0002]

2. Description of the Related Art Among the characteristics required for materials for electric / electronic devices and semiconductor devices, electric characteristics and heat resistance are the most important characteristics. In particular, in recent years, with miniaturization of circuits and speeding up of signals, an insulating material having a low dielectric constant has been required. An insulating material using a heat-resistant resin is expected as a material for achieving both of these characteristics. For example,
Conventionally, inorganic insulating materials such as silicon dioxide have high heat resistance, but have a high dielectric constant and the required characteristics are now sophisticated. A heat-resistant resin typified by a polyimide resin has excellent electrical characteristics and heat resistance, and can achieve both of the two characteristics, and is actually used for a coverlay of a printed circuit, a passivation film of a semiconductor device, and the like.

[0003] However, with recent advances in the functions and performance of semiconductor devices, remarkable improvements in electrical characteristics and heat resistance have been required, so that even higher performance resins have been required. ing. In particular, a low dielectric constant material having a dielectric constant of less than 2.5 is expected, and a conventional insulating material does not reach required characteristics. In contrast, heretofore, for example, to a resin composition comprising polyimide and a solvent, a heat-decomposable resin other than polyimide is added, and a heating step is performed to decompose the heat-decomposable resin to form voids. Thus, attempts have been made to reduce the dielectric constant of the insulating material. However, when the heat-resistant resin such as polyimide and the heat-decomposable resin are compatible with each other, the glass transition point is lowered, so that when the heat-decomposable resin is decomposed, the voids are crushed and the effect of reducing the dielectric constant is reduced. Less is. In addition, even if a heat-resistant resin such as polyimide and a thermally decomposable resin are successfully formed into a phase-separated structure without being compatible with each other, a large amount of labor is required for a heating method or the like when decomposing the thermally decomposed resin. Was something.

[0004]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a resin composition for an insulating material which exhibits an extremely low dielectric constant and good insulating properties, and also has excellent heat resistance and an insulating material using the same. Aim.

[0005]

Means for Solving the Problems The present inventors have made intensive studies in view of the above-mentioned conventional problems, and as a result, have completed the present invention by the following means.

That is, the present invention provides: A resin composition for an insulating material comprising a component (A) having a hollow structure having a free volume of 0.001 to 1000 nm ³ and a heat-resistant resin or its precursor (B) as essential components;

[0007] 2. The resin composition for an insulating material according to claim 1, wherein the component (A) having a hollow structure having a free volume of 0.001 to 1000 nm ³ is fullerene,

[0008] 3. 2. The resin composition for an insulating material according to claim 1, wherein the component (A) having a hollow structure having a free volume of 0.001 to 1000 nm ³ is a carbon nanotube.

4. First to third heat-resistant resins or their precursors (B) are polyimide resins or polyimide precursors.
The resin composition for an insulating material according to any one of the above items,

[0010] 5. Item 4. The resin composition for an insulating material according to any one of Items 1 to 3, wherein the heat-resistant resin or its precursor (B) is a polybenzoxazole resin or a polybenzoxazole precursor.

6. An insulating material obtained by using the resin composition for an insulating material according to any one of Items 1 to 5.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The resin composition for insulating material of the present invention comprises:
It comprises, as essential components, a component (A) having a hollow structure having a free volume of 0.001 to 1000 nm ³ and a heat-resistant resin or its precursor (B). Solvents can be used as components other than the component (A) and the heat-resistant resin or its precursor (B).

The resin composition for an insulating material of the present invention can be applied to a substrate or the like and heated and formed into a film, or impregnated in a glass cloth or the like and heated to form an insulating material. The components (A) to free volume having a hollow structure is 0.001~1000nm ^3, the heat resistant resin or its precursor (B), and
The composition can be obtained by mixing or chemically bonding. Since the dielectric constant inside the void of the component (A) is air, it is considered to be 1. Therefore, by adding the component (A) to a heat-resistant resin or its precursor (B) larger than 1 to obtain a dielectric constant. The hollow structure is maintained even after the insulating material is formed, and an insulating material having a low dielectric constant can be obtained.

The free volume used in the present invention is 0.001 to 1000 nm ³
Examples of the component (A) having a hollow structure are: fullerene C60, fullerene C70, fullerene C7
6, fullerene C78, fullerene C82, single-walled carbon nanotube, multi-walled carbon nanotube, calixarene, α-cyclodextrin, β-cyclodextrin, γ-cyclodextrin, δ-cyclodextrin, crown ether, etc., but are not limited thereto. Not something. Of these, fullerenes and carbon nanotubes are preferred. Further, only one of these may be used, or two or more thereof may be used in combination.

Examples of the heat-resistant resin or its precursor (B) used in the present invention include polyimide, polyamic acid,
Polyamic acid ester, polyisoimide, polyamideimide, polyamide, bismaleimide, polybenzoxazole, polyhydroxyamide, polybenzothiazole, etc., but not limited thereto. Among them, a polyimide resin, a polyimide precursor such as polyamic acid, polyamic acid ester and polyisoimide, a polybenzoxazole resin, and a polybenzoxazole precursor such as polyhydroxyamide are preferable because of high heat resistance. Also, these may be used alone,
They may be mixed or copolymerized.

When a solvent is used as a component of the resin composition for insulating material of the present invention, preferable examples thereof include N, N-dimethylacetamide, N-methyl-2-pyrrolidone, tetrahydrofuran, propylene glycol monomethyl ether. Propylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, γ-butyrolactone, 1,1,2,2-tetrachloroethane, and the like, but are not limited thereto.
Further, two or more of these may be used simultaneously. further,
A surfactant may be added to improve coatability and impregnation.

The resin composition for an insulating material of the present invention is obtained by blending each component so that the porosity of the insulating material is 1 to 70% by volume, and uniformly mixing or chemically bonding them. Can be The mixing ratio is such that the weight ratio A / B of the component (A) and the component (B) is 5/95 to 90/10, and more preferably 10/90 to 70/30.

Examples of the method for producing an insulating material of the present invention include:
The resin composition for an insulating material of the present invention is dissolved in the above-mentioned solvent to form a varnish, and then applied to an appropriate support, for example, a glass, metal, silicone wafer, or ceramic substrate. Specific coating methods include spin coating using a spinner, spray coating using a spray coater, dipping,
Printing, roll coating and the like. Thus, by forming a coating film and drying by heating, an insulating material having a low dielectric constant can be formed.

[0019]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which by no means limit the present invention.

Example 1 (1) Synthesis of polyimide resin In a separable flask equipped with a stirrer, a nitrogen inlet tube, and a raw material inlet, 2,2′-bis (4- (4,4′-aminophenoxy) was used. ) Phenyl) hexafluoropropane 5.1
8 g (0.01 mol) and 9.60 g of 2,2'-bis (trifluoromethyl) -4,4'-diaminobiphenyl
(0.03 mol) is dissolved in 200 g of dried N-methyl-2-pyrrolidone (hereinafter abbreviated as NMP). The solution was cooled to 10 ° C. under dry nitrogen, and 2.94 g (0.01 mol) of biphenyltetracarboxylic dianhydride and 13.32 g of hexafluoroisopropylidene-2,2′-bis (phthalic anhydride) ( 0.03 mol) was added. Five hours after the addition, the temperature was returned to room temperature, and the mixture was stirred at room temperature for 2 hours to obtain a solution of polyamic acid as a polyimide precursor. After 50 g of pyridine was added to this polyamic acid solution, 5.1 g (0.05 mol) of acetic anhydride was added dropwise, and an imidization reaction was carried out for 7 hours while maintaining the temperature of the system at 70 ° C. This solution was dropped into 20 times the volume of water to collect a precipitate, which was then vacuum-dried at 60 ° C. for 72 hours to obtain a solid polyimide resin as a heat-resistant resin. The molecular weight of the polyimide resin is 26,000 number average molecular weight, 54 weight average molecular weight.
000.

(2) Preparation of Resin Composition for Insulating Material and Production of Insulating Material 10.0 g of the polyimide resin synthesized above was
After dissolving in 50.0 g of butyrolactone / 1,1,2,2-tetrachloroethane (70/30, vol / vol), 2.0 g of high-purity fullerene C60 (99.98%, manufactured by Term) is added. The mixture was stirred to obtain a resin composition for an insulating material. This resin composition for an insulating material was spin-coated on a silicon wafer on which a 200-nm-thick tantalum film was formed, and then heated and cured in an oven in a nitrogen atmosphere. At the time of heat curing, the substrate was kept at 120 ° C. for 4 minutes, 150 ° C. for 30 minutes, and then kept at 400 ° C. for 60 minutes. Thus, a 0.8 μm thick insulating film was obtained. An aluminum electrode having an area of 0.1 cm ² is formed on the insulating film by vapor deposition, and the capacitance between the electrode and tantalum on the substrate is determined by LCR.
It was measured with a meter. The dielectric constant of the insulating material calculated from the film thickness, the electrode area, and the capacitance was 2.4. The density of the insulating material was determined to be 1.10. The density in the case where fullerene C60 was not added and there were no voids was 1.41, and the porosity was calculated to be 22.0% from this. Further, when the cross section of the insulating material film was observed with a TEM, it was found that voids having a diameter of 0.7 nm were uniformly dispersed.

Example 2 (1) Synthesis of Polyimide Precursor In the synthesis of the polyimide resin of Example 1, 2,2′-bis (4- (4,4′-
5.18 g (0.01 mol) of aminophenoxy) phenyl) hexafluoropropane and 2,2′-bis (trifluoromethyl) -4,4′-diaminobiphenyl
60 g (0.03 mol) and 4,01′-diaminodiphenyl ether (8.01 g, 0.04 mol) and biphenyltetracarboxylic dianhydride 2.94 g (0.01
mol) and hexafluoroisopropylidene-2,2 '
13.32 g of bis (phthalic anhydride) (0.03 mol
l) and 8.72 g (0.04 g) of pyromellitic dianhydride
mol), a solution of polyamic acid as a polyimide precursor was obtained in the same manner as in Example 1. This solution was dropped into 20 times the volume of water to collect a precipitate.
Vacuum drying was performed for 2 hours to obtain a solid of polyamic acid which is a precursor of polyimide which is a heat-resistant resin. The number average molecular weight of the obtained polyamic acid was 27,000, and the weight average molecular weight was 55,000.

(2) Preparation of Resin Composition for Insulating Material and Production of Insulating Material 10.0 g of the polyamic acid synthesized as described above was mixed with γ-butyrolactone / 1,1,2,2-tetrachloroethane (7
0/30, vol / vol), and then dissolved in 50.0 g of high-purity fullerene C60 (99.98%, manufactured by Term).
2.0 g was added and stirred to obtain a resin composition for an insulating material. This resin composition for an insulating material was spin-coated on a silicon wafer on which a 200-nm-thick tantalum film was formed, and then heated and cured in an oven in a nitrogen atmosphere. In the case of heat curing, after holding at 120 ° C. for 4 minutes and 150 ° C. for 30 minutes,
It was kept at 400 ° C. for 60 minutes. Thus, a coating of an insulating material having a thickness of 0.7 μm was obtained. Thereafter, the dielectric constant of this heat-resistant resin was measured in the same manner as in Example 1.
It was 4. Moreover, the density of the insulating material was determined to be 1.13 using a density gradient tube. The density in the case where fullerene C60 was not added and there were no voids was 1.43, and thus the porosity was calculated to be 21.0%. Further, when the cross section of the insulating material film was observed with a TEM, it was found that voids having a diameter of 0.7 nm were uniformly dispersed.

Example 3 (1) Synthesis of polybenzoxazole resin 25 g of 4,4'-hexafluoroisopropylidenediphenyl-1,1'-dicarboxylic acid, 45 m of thionyl chloride
l and 0.5 ml of dry dimethylformamide were placed in a reaction vessel and reacted at 60 ° C. for 2 hours. After completion of the reaction, excess thionyl chloride was distilled off by heating and reduced pressure. The residue was recrystallized from hexane to obtain 4,4'-hexafluoroisopropylidenediphenyl-1,1'dicarboxylic acid chloride. In a separable flask equipped with a stirrer, a nitrogen introducing tube, and a dropping funnel, 7.32 g (0.02 mol) of 2,2′-bis (3-amino-4-hydroxyphenyl) hexafluoropropane was added to 100 g of dried dimethylacetamide. 3.96 g of pyridine
(0.05 mol), and then -15 under dry nitrogen introduction.
At 50 ° C., 8.58 g of 4,4′-hexafluoroisopropylidenediphenyl-1,1′-dicarboxylic acid chloride synthesized above in 50 g of dimethylacetamide (0.5 g).
02mol) was added dropwise over 30 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 added dropwise to 1000 ml of water, and the precipitate was collected and dried under vacuum at 40 ° C. for 48 hours.
A solid substance of polyhydroxyamide, which is a polybenzoxazole precursor, was obtained. This polyhydroxyamide is NM
After 50 g of pyridine was added to the solution dissolved in 200 g of P, 3.1 g (0.03 mol) of acetic anhydride was added dropwise, and the oxazole-forming reaction was carried out for 7 hours while maintaining the temperature of the system at 70 ° C. This solution was dropped into a 20-fold amount of water to collect a precipitate, followed by vacuum drying at 60 ° C. for 72 hours to obtain a solid substance of a polybenzoxazole resin as a heat-resistant resin. The number average molecular weight of the obtained polybenzoxazole resin is 200
00, and the weight average molecular weight was 40,000.

(2) Preparation of resin composition for insulating material and production of insulating material Polybenzoxazole resin synthesized as described above
After dissolving 0 g in 50.0 g of γ-butyrolactone / 1,1,2,2-tetrachloroethane (70/30, vol / vol), single-wall carbon nanotubes (manufactured by MER)
2.0 g was added and stirred to obtain a resin composition for an insulating material. This resin composition for an insulating material was spin-coated on a silicon wafer on which a 200-nm-thick tantalum film was formed, and then heated and cured in an oven in a nitrogen atmosphere. At the time of heat curing, the substrate was kept at 120 ° C. for 4 minutes, 150 ° C. for 30 minutes, and then kept at 400 ° C. for 60 minutes. Thus, a 0.7 μm thick insulating film was obtained. Thereafter, the dielectric constant of this heat-resistant resin was measured in the same manner as in Example 1.
It was one. Further, the density of the insulating material was determined to be 1.11 by a density gradient tube. The density when no single-walled carbon nanotubes were added and there were no voids was 1.45.
Therefore, the porosity was calculated to be 23.4% from this. Further, when the cross section of the insulating material film was observed with a TEM, it was found that voids having a diameter of 0.2 nm and a length of 4 nm were uniformly dispersed.

Example 4 (1) Synthesis of polyhydroxyamide 2,2'-bis (trifluoromethyl) biphenyl-
4,4'-dicarboxylic acid 22g, thionyl chloride 45ml
And 0.5 ml of dry dimethylformamide was put into a reaction vessel and reacted at 60 ° C. for 2 hours. After completion of the reaction, excess thionyl chloride was distilled off by heating and reduced pressure. The residue,
Recrystallization from hexane gave 2,2'-bis (trifluoromethyl) biphenyl-4,4'-dicarboxylic acid chloride. In a separable flask equipped with a stirrer, nitrogen inlet tube, and dropping funnel, 2,2′-bis (3-amino-4
-Hydroxyphenyl) hexafluoropropane7.3
2 g (0.02 mol) was dissolved in 100 g of dried dimethylacetamide, and 3.96 g (0.05%) of pyridine was dissolved.
mol), 2,2 ′ synthesized above in 50 g of dimethylacetamide at −15 ° C. under dry nitrogen introduction.
-Bis (trifluoromethyl) biphenyl-4,4'-
A solution in which 8.30 g (0.02 mol) of dicarboxylic acid chloride was dissolved was added dropwise over 30 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 1000 ml of water, and the precipitate was collected.
Vacuum drying was performed at 48 ° C. for 48 hours to obtain a solid substance of polyhydroxyamide which is a polybenzoxazole precursor which is a heat-resistant resin. The number average molecular weight of the obtained polyhydroxyamide is 20,000, and the weight average molecular weight is 4
0000.

(2) Preparation of resin composition for insulating material and production of insulating material 10.0 g of polyhydroxyamide synthesized as described above
Was dissolved in 50.0 g of γ-butyrolactone / 1,1,2,2-tetrachloroethane (70/30, vol / vol), and then a single-walled carbon nanotube (manufactured by MER) 2.0
g was added and stirred to obtain a resin composition for an insulating material. Thickness 2
The resin composition for an insulating material was spin-coated on a silicon wafer on which a 00 nm tantalum film was formed, and then heat-cured in an oven in a nitrogen atmosphere. In the case of heat curing, 12
After holding at 0 ° C for 4 minutes and 150 ° C for 30 minutes, 400 ° C
For 60 minutes. Thus, the thickness of 0.7 μm
Was obtained. Thereafter, the dielectric constant of this heat-resistant resin insulating material was measured in the same manner as in Example 1, and it was 2.1. Moreover, the density of the heat-resistant resin insulating material was determined to be 1.15 using a density gradient tube. Since the density when no single-walled carbon nanotube was added and there were no voids was 1.42, the porosity was calculated to be 19.0% from this. Further, when the cross section of the insulating material film was observed with a TEM, it was found that voids having a diameter of 0.2 nm and a length of 4 nm were uniformly dispersed.

Comparative Example 1 Fullerene C60 (99.98) used in the preparation of the insulating resin composition of Example 1 was used.
%, Manufactured by Term Co.), except for the addition of 2.0 g, the preparation of a resin composition for an insulating material and the production of an insulating material were performed in the same manner as in Example 1. The dielectric constant of the obtained heat-resistant resin insulating material is 2.
9, and the density was 1.41. No void was observed in the cross section of the insulating film by TEM.

Comparative Example 2 Fullerene C60 (99.98) used in the preparation of the insulating resin composition of Example 2 was used.
%, Manufactured by Term Co.), except that no addition of 2.0 g, the preparation of the insulating resin composition and the production of the insulating material were carried out in the same manner as in Example 2. The obtained heat-resistant resin had a dielectric constant of 3.0 and a density of 1.43. No void was observed in the cross section of the insulating film by TEM.

Comparative Example 3 Single-Walled Carbon Nanotubes Used in Preparation of Resin Composition for Insulating Material of Example 3
Except not adding 0 g, adjustment of the resin composition for insulating materials and manufacture of insulating materials were performed in the same manner as in Example 3 in all cases. The resulting heat-resistant resin has a dielectric constant of 2.6 and a density of 1.45.
Met. No void was observed in the cross section of the insulating film by TEM.

Comparative Example 4 Single-Walled Carbon Nanotubes Used in Preparation of Resin Composition for Insulating Material of Example 4
Except not adding 0 g, adjustment of the resin composition for insulating materials and manufacture of insulating materials were performed in the same manner as in Example 4. The obtained heat-resistant resin has a dielectric constant of 2.6 and a density of 1.42.
Met. No void was observed in the cross section of the insulating film by TEM.

In Examples 1 to 4, the dielectric constant was 2.1.
A very low heat-resistant resin of ~ 2.4 was obtained.
In Comparative Examples 1 to 4, the dielectric constant could not be reduced because the component (A) having a hollow structure having a free volume of 0.001 to 1000 nm ³ was not contained.

[0033]

Industrial Applicability The resin composition for insulating material of the present invention and the insulating material using the same are excellent in electrical properties and heat resistance, and are used in various fields where these properties are required, for example,
It is useful as an interlayer insulating film for a semiconductor, an interlayer insulating film of a multilayer circuit, and the like.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01B 3/00 H01B 3/00 A 3/02 3/02 Z 3/30 3/30 DH // H01L 21/312 H01L 21/312 A H05K 3/28 H05K 3/28 CF term (reference) 4J002 AA001 CM021 CM041 DA016 FD206 GQ01 5E314 AA36 AA41 BB01 5F058 AA10 AB05 AB07 AC02 AD04 AF04 AG01 AH02 5G303 AA11 AB01 BA12 CA12 AA07 AB01 AB24 BA15 CA21 CA32 CC01 CD01

Claims (6)

[Claims] 1. A resin composition for an insulating material comprising a component (A) having a hollow structure having a free volume of 0.001 to 1000 nm ³ and a heat-resistant resin or its precursor (B) as essential components. 2. The resin composition for an insulating material according to claim 1, wherein the component (A) having a hollow structure having a free volume of 0.001 to 1000 nm ³ is fullerene. 3. The resin composition for an insulating material according to claim 1, wherein the component (A) having a hollow structure having a free volume of 0.001 to 1000 nm ³ is a carbon nanotube. 4. The heat-resistant resin or its precursor (B) is a polyimide resin or a polyimide precursor.
4. The resin composition for an insulating material according to any one of 3. 5. The resin composition for an insulating material according to claim 1, wherein the heat-resistant resin or its precursor (B) is a polybenzoxazole resin or a polybenzoxazole precursor. 6. An insulating material obtained by using the resin composition for an insulating material according to claim 1. Description: