WO2002077714A1

WO2002077714A1 - Self-flame-retardant resist material and insulating material

Info

Publication number: WO2002077714A1
Application number: PCT/JP2002/002633
Authority: WO
Inventors: Hiroshi Tsushima
Original assignee: Nippon Paint Co., Ltd.
Priority date: 2001-03-26
Filing date: 2002-03-20
Publication date: 2002-10-03
Also published as: TW556463B; TW200308192A; TW573449B

Abstract

A resist material and an insulating material each characterized by comprising a photosensitive resin composition which comprises: (A) a polysilane which is soluble in organic solvents and has a weight-average molecular weight of 10,000 or higher; (B) a photo-radical generator and an oxidizing agent; (C) a silicone compound of a structure represented by the following general formula (1) (wherein R?1, R2, R3, R4, R5, and R6¿ may be the same or different and each represents a group selected from the group consisting of C¿1-10? aliphatic hydrocarbon groups optionally substituted by a halogen or glycidyl, optionally halogenated C6-12 aromatic hydrocarbon groups, and C1-8 alkoxys, provided that the molecule contains at least two C1-8 alkoxys; and m and n each is an integer satisfying the relationship m+n=1); and (D) an organic solvent.

Description

Description Self-flame retardant resist materials and insulating materials

The present invention relates to a self-flammable resist material and an insulating material that can be used for forming a solder resist film on a printed wiring board, and a method for forming a printed wiring board or an insulating film using the same. Background art

As a method of applying solder to a predetermined portion of a wiring portion of a printed wiring board, a method of forming a solder resist pattern on a printed wiring board is generally adopted. Solder resist is used to apply solder only to places where the pattern is not formed, prevent solder from sticking to the place where the pattern is formed, and protect the circuit where the pattern is formed. belongs to.

Halogen-based flame retardants are used in solder resists as a measure to make electrical components flame-retardant. Since this flame retardant contains halogen, it is highly likely to be a causative substance of dioxin. In addition, since the conventional solder resist contains epoxy resin as a main component, it contains bisphenol A, a causative substance of environmental hormones, and may be subject to use restrictions in the future. Also, the use of heat-resistant resin such as polyimide as solder resist is being studied. However, in the case of solder resist, crosstalk between conductors poses a problem, and a material having a low dielectric constant is required. In this respect, polyimide is not a satisfactory material. R On the other hand, in the field of semiconductors, conventional aluminum wiring has shifted to copper wiring, and the interlayer insulating film used there has also shifted from conventional silica films produced by CVD to materials with lower dielectric constants. Have been doing. However, a low dielectric constant interlayer insulating film that can be patterned by a simple process has not been found so far. Disclosure of the invention

An object of the present invention is to provide a resist material and an insulating material having a low dielectric constant and self-flammability.

The self-flame retardant resist material of the present invention comprises: (A) a polysilane having a weight average molecular weight of 10,000 or more soluble in an organic solvent; (B) a photoradical generator and an oxidizing agent; A silicone compound having a structure represented by the formula:

(In the formula, R ¹ R ² , R ³ , R ⁴ , R ⁵ and R ^{6 each} have a carbon number of from 1 to 10 and may be substituted with a halogen or daricidyl group, an aliphatic hydrocarbon group, A group selected from the group consisting of an aromatic hydrocarbon group which may be substituted with a halogen having 6 to 12 carbon atoms and an alkoxy group having 1 to 8 carbon atoms, which may be the same or different from each other However, at least two of the above alkoxy groups are contained in one molecule, and m and n are integers and satisfy m + n≥l.)

(D) It is characterized by comprising a photosensitive resin composition containing an organic solvent. The insulating material of the present invention is characterized by comprising the above-mentioned photosensitive resin composition, like the self-flame-retardant resist material of the present invention.

When the photosensitive resin composition is irradiated with light such as ultraviolet rays, the Si—Si bond present in the polysilane is broken, and Si—OH (silanol group) is generated. Since the silanol group is weakly acidic, it can be dissolved in an alkaline aqueous solution or the like, so that the exposed portion can be removed and developed. Therefore, it can be used as a resist material.

Further, when the thin film formed from the photosensitive resin composition is heated, the alkoxy group in the silicone compound contained in the thin film is decomposed to generate a silanol group, and the silanol group reacts with the polysilane to crosslink polycyan. Can be cured. Therefore, a thin film having heat resistance can be obtained.

Further, since the main component of the photosensitive resin composition is polysilane, it has self-flame retardancy and a low dielectric constant. Therefore, a resist material and an insulating material having a low dielectric constant and having self-flammability can be obtained. A method for manufacturing a printed wiring board according to the present invention is a method for manufacturing a printed wiring board having a solder resist film formed on a surface thereof. The resist material of the present invention is applied on the printed wiring board to form a solder resist film. The method includes a step of forming, a step of selectively exposing and developing the solder resist film to expose a wiring portion to which the solder is attached, and a step of heating and curing the developed solder resist film.

The method for forming an insulating film of the present invention is characterized in that the insulating material of the present invention is applied on a substrate, dried, and then heated and cured.

The photosensitive resin composition used as a resist material and an insulating material in the present invention will be described in detail below. <Photosensitive resin composition>

The photosensitive resin composition used as the resist material and the insulating material in the present invention is a polysilane having a weight average molecular weight of 100,000 or more soluble in an organic solvent, a photoradical generator, an oxidizing agent, a silicone compound, and an organic solvent. Is included. Hereinafter, these will be described.

(Polysilane)

Examples of the polysilane used in the present invention include a network type and a linear type. Considering the mechanical strength of the photosensitive material, a network-like polysilane is preferable. Network-like and chain-like are distinguished by the bonding state of Si atoms contained in polysilane. The network-like polysilane is a polysilane containing Si atoms in which the number (the number of bonds) bonded to adjacent Si atoms is 3 or 4. On the other hand, in a linear polysilane, the number of Si atoms bonded to adjacent Si atoms is two. Since the valence of Si atom is usually 4, the Si atom present in polysilane having a bond number of 3 or less is considered to be a hydrocarbon group, an alkoxy group or a hydrogen atom in addition to the Si atom. Are combined. As such a hydrocarbon group, an aliphatic hydrocarbon group having 1 to 10 carbon atoms and optionally substituted with halogen, and an aromatic hydrocarbon group having 6 to 14 carbon atoms are preferable.

Specific examples of the aliphatic hydrocarbon group include a linear group such as a methyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, a trifluoropropyl group and a nonafluorohexyl group; Examples include alicyclic groups such as a hexyl group and a methylcyclyl hexyl group.

Specific examples of the aromatic hydrocarbon group include a phenyl group, a p-tolyl group, a biphenyl group and an anthracyl group. Examples of the alkoxy group include those having 1 to 8 carbon atoms. Specific examples include a methoxy group, an ethoxy group, a phenoxy group, and an octyloxy group. Among these, a methyl group and a phenyl group are particularly preferable in view of ease of synthesis.

In the case of a network-like polysilane, the number of Si atoms having 3 or 4 bonds with adjacent Si atoms should be 2 to 50% of the total number of Si atoms in the network-like polysilane. Is preferred. This value can be determined by measuring the nuclear magnetic resonance spectrum of silicon.

The polysilane in the present specification includes a mixture of a network-like polysilane and an i: chain-like polysilane. In this case, the content of the above s i atoms is calculated by the average of the network-like polysilane and the linear polysilane.

The polysilane used in the present invention is polycondensed by heating a halogenated silane compound to 80 ° C or higher in an organic solvent such as n-decane or toluene in the presence of an alkali metal such as sodium. It can be produced by a reaction.

The network-like polysilane is composed of, for example, an organotrihalosilane compound, a tetrahalosilane compound, and a diorganodihalosilane compound. ⁰ / halosilane mixture is less than ₀ can be obtained by polycondensation by heating. Here, the organotrihalosilane compound is a Si atom source having 3 bonds with adjacent Si atoms, and the tetrahalosilane compound is 4 bonds with adjacent Si atoms. It becomes a Si atom source. The structure of the network can be confirmed by measuring the ultraviolet absorption spectrum or the nuclear magnetic resonance spectrum of silicon.

The linear polysilane is subjected to the same reaction as that of the above-mentioned network-type polysilane except that a plurality or a single diorganodichlorosilane is used. Can be manufactured more.

The halogen atoms contained in each of the organotrihalosilane compound, the tetrahalosilane compound, and the diorganodihalosilane compound used as the raw material for the polysilane are preferably chlorine atoms. Examples of the substituent other than the halogen atom contained in the organotrihalosilane compound and the diorganodihalosilane compound include the above-mentioned hydrocarbon group, alkoxy group and hydrogen atom.

These network-like and straight-chain polysilanes are not particularly limited as long as they are soluble in an organic solvent and have a weight-average molecular weight of 1000 or more. In consideration of use as a photosensitive material, it is preferable that the polysilane used in the present invention is soluble in an evaporable organic solvent. Examples of such organic solvents include hydrocarbons having 5 to 12 carbon atoms, halogenated hydrocarbons, and ethers.

Examples of hydrocarbons include pentane, hexane, heptane, cyclohexane, n-decane, n-dodecane, benzene, toluene, xylene, methoxybenzene, and the like. Examples of halogenated hydrocarbons include carbon tetrachloride, chloroform, 1,2-dichloroethane, dichloromethane, and cyclobenzene. Examples of ethers include dimethyl ether, dibutynoleatenole, and tetrahide-furan.

The polysilane used in the present invention has a weight average molecular weight of 100,000 or more. If the weight average molecular weight is less than 1000, the film properties such as chemical resistance and heat resistance may be insufficient. The preferred weight average molecular weight is from 1,000 to 500,000, and more preferably from 1500 to 300,000.

(Photo radical generator and oxidizer) The photo-radical generator used in the present invention is not particularly limited as long as it is a compound that generates halogen radicals by light, and 2,4,6-tris (trihalomethyl) -11,3,5-triazine and its 2- Compound substituted at the 2- or 4-position, phthalimid trihalomethanesulfonate and a compound having a substituent on its benzene ring, naphthalimid trihalomethanesulfonate and a compound having a substituent on the benzene ring And the like. The substituents of these compounds are an aliphatic or aromatic hydrocarbon group which may have a substituent. The oxidizing agent used in the present invention is not particularly limited as long as it is a compound serving as an oxygen supply source, and examples thereof include peroxides, amine oxides, and phosphine oxides.

As the combination of the photoradical generator and the oxidizing agent, a combination of a tricyclic triazine compound as the photoradical generating agent and a peroxide as the oxidizing agent is particularly preferable.

The photo-radical generator is added for the purpose of efficiently breaking the Si-Si bond by halogen radicals when the polysilane is decomposed by light irradiation. The oxidizing agent is added so that oxygen is easily introduced into the Si bond after the cleavage.

A coumarin-based, cyanine-based, or merocyanine-based soluble dye may be added in order to increase the generation of halogen radicals by the photoexcitation of the dye. Further, by adding a soluble dye, the sensitivity of polysilane to light can be improved.

(Silicone compound)

As the silicone compound used in the present invention, a silicone compound having a structure represented by the following general formula is preferably used.

(Wherein, RR ² , RR ⁴ , 1 ^ ⁵ and 1 ^ ⁶ represent an aliphatic hydrocarbon group having 1 to 10 carbon atoms, which may be substituted with a halogen or glycidyl group, and 6 to 1 carbon atoms. 2 is a group selected from the group consisting of an aromatic hydrocarbon group optionally substituted by o, and an alkoxy group having 1 to 8 carbon atoms, and may be the same or different from each other; One molecule contains at least two of the above alkoxy groups, where m and n are integers and satisfy m + n≥l.)

Specific examples of the aliphatic hydrocarbon group which is a substituent of R ^{1 to} R 6 include a methynole group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, a trifluoropropyl group, and a glycidyloxy group. Examples thereof include linear ones such as a propyl group, and alicyclic ones such as a cyclohexyl group and a methylcyclohexyl group. Further, specific examples of the aromatic hydrocarbon group include a phenyl group, a p-tolyl group, a biphenyl group and the like. Specific examples of the alkoxy group include a methoxy group, an ethoxy group, a phenoxy group, an octyloxy group, a ter-butoxy group, and the like.

The types of R ′ to ⁶ and the values of m and n are not particularly important, and are not particularly limited as long as they are compatible with polysilane and an organic solvent. In consideration of the compatibility, the polysilane used preferably has the same hydrocarbon group as the polysilane used. For example, when a phenylmethyl-based polysilane is used, it is preferable to use the same phenylmethyl-based or diphenyl-based silicone compound.

In the silicone compound used in the present invention, R ^{1 in} one molecule Of to R ^6, two at least, but is an alkoxy group having 1-8 carbon atoms. Therefore, since one molecule has two or more alkoxy groups, it functions as a crosslinking agent for polysilane. As such, the alkoxy group is 15-35 weight ^0/0 . Examples include methylphenylmethoxysilicone and phenylmethoxysilicone.

The weight average molecular weight of the silicone compound used in the present invention is preferably 1000 or less, more preferably 300 or less. If the weight average molecular weight is too high, the compatibility with the polysilane will be reduced, resulting in a non-uniform film or reduced sensitivity.

(Organic solvent)

The organic solvent contained in the photosensitive resin composition of the present invention is not particularly limited as long as it can dissolve polysilane, and specific examples include the organic solvents exemplified in the description of polysilane. Is received.

(Blending ratio in photosensitive resin composition)

The mixing ratio of the photosensitive resin composition used in the present invention is as follows: 100 to 100 parts by weight of polysilane, 1 to 30 parts by weight of a photo radical generator, oxidizing agent:! To 30 parts by weight, silicone compound 5 to Preferably it is 100 parts by weight. Further, when the above-mentioned soluble dye is added, the amount is preferably 1 to 20 parts by weight based on 100 parts by weight of the polysilane. The organic solvent is preferably used so that the concentration with respect to the whole is 20 to 60% by weight.

The silicone compound functions as a crosslinking agent for the polysilane, increases the solubility of the polysilane in an organic solvent, and also functions as a compatibilizer between the polysilane, the photoradical generator, and the oxidizing agent. Therefore, by using a silicon compound, the amount of the photo radical generator and the oxidizing agent can be increased. Can be included.

(Coating method of photosensitive resin composition)

The method for applying the photosensitive resin composition is not particularly limited, and can be performed by a method known to those skilled in the art. It can be applied by a spin coater method, a screen printing method, a method using an applicator, or the like. The application method is appropriately selected depending on the intended use.

When used as a resist material for a printed wiring board, it is generally preferable to apply the method by screen printing or a method using an applicator. The thickness of the resist film is generally applied to a dry film thickness in the range of 10 to 50 μm.

When the insulating material of the present invention is used as an interlayer insulating film in the semiconductor field, it is generally applied by a spin coater method or the like. The film thickness is often in the range of about 0.1 to 5 μm.

FIG. 1 is a schematic cross-sectional view showing one example of a manufacturing process of a printed wiring board of the present invention.

As shown in FIG. 1A, a wiring section 2 formed by patterning a copper layer is provided on a substrate 1. A solder resist film 3 is formed by applying a resist material made of a photosensitive resin composition on the wiring portion 2.

Next, as shown in FIG. 1 (b), a mask 4 patterned so as to irradiate the wiring portion 2 to be exposed with light is placed on the solder resist film 3 and irradiated with ultraviolet rays 5. Expose.

The ultraviolet light to be irradiated has a wavelength of 250 to 40 O nm, which is the σ-σ * absorption region of polysilane. This irradiation is performed at a rate of 0.01 to IJ cm ² , preferably 0.1 to 0.5 J / cm ² per μm of the thickness of the solder resist film 3.

0 Of light. If the irradiation light quantity is less than 0.01 J / cm ² , the developability will be reduced, and if it exceeds 1 J / cm ² , the pattern reproducibility will be reduced. High- and ultra-high-pressure mercury lamps, xenon lamps, metal halide lamps, etc. are used as UV light sources, and He-Cd lasers, Ar lasers, YAG lasers, excimer lasers, etc. are used for laser scanning. it can.

In the region irradiated with ultraviolet light, the Si—Si bond is broken by the ultraviolet light irradiation, and Si—OH (silanol group) is generated. Accordingly, a latent image having a silanol group according to the pattern of the mask 4 is formed on the solder resist film 3 irradiated with the ultraviolet rays. Since the silanol group is weakly acidic, it can be dissolved in an alkaline aqueous solution. Therefore, as shown in FIG. 1 (c), after irradiation with ultraviolet rays, the exposed portions can be removed and developed using an alkaline aqueous solution. As the alkaline aqueous solution, an amine type such as tetramethylammonium hydroxide (TMAH) or an inorganic base such as sodium hydroxide can be used, and a 2.4% aqueous solution of TMAH is particularly preferable. Used. To these aqueous solutions, an alcohol-based solvent may be added for the purpose of swelling the exposed portions of the solder resist film 3.

As shown in FIG. 1 (c), by removing and developing a predetermined portion of the solder resist film 3, the wiring portion 2 to which the solder is attached can be exposed.

When the photosensitive resin composition is used as a material for forming an interlayer insulating film in the semiconductor field, etc., as described above, the photosensitive resin composition is formed by a method well known to those skilled in the art such as a spin coater method. Is applied. If the interlayer insulating film requires patterning, it is necessary to selectively irradiate ultraviolet rays and develop it in the same manner as the resist material on the printed wiring board. More patterning is possible. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a schematic cross-sectional view for explaining a manufacturing process of a printed wiring board according to the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described specifically with reference to examples. However, the present invention is not limited to the following examples, and can be appropriately modified and implemented within the scope of the present invention. is there.

(Preparation of polysilane)

A 1000 ml flask equipped with a stirrer was charged with 400 ml of toluene and 13.3 g of sodium. The contents of the flask were heated to 111 ° C in a yellow room where ultraviolet rays were blocked, and sodium was finely dispersed in toluene by high-speed stirring. To this, 42.1 g of phenylmethyldichlorosilane and 4.lg of tetrachlorosilane were added, and the mixture was stirred for 3 hours to carry out polymerization. Thereafter, excess sodium was quenched by adding ethanol to the resulting reaction mixture. After washing with water, the separated organic layer was poured into ethanol to precipitate polysilane. The obtained crude polysilane was reprecipitated from ethanol three times to obtain a network-like polymethylphenylsilane having a weight-average molecular weight of 11,600.

100 parts by weight of the network-like polysilane obtained in Preparation Example 1, TSR-165 as a silicone compound (methylphenylmethyl with a molecular weight of 930) Toxicone corn resin, methoxy group content: 15% by weight, 10 parts by weight, TAZ-110 (2,4-bis (trichloromethylmethyl) as a photo-radical generator 1) 6- (p-Methoxypheninolebinin) -1,3,5-triazine, manufactured by Midori Kagaku Co., Ltd.) 10 parts by weight, and ΒΤΤΒ (3, 3 ', 4, 4') as an oxidizing agent —15 parts by weight of tetra (t-butylperoxycarbonyl) benzophenone (manufactured by NOF CORPORATION) was dissolved in 125 parts by weight of toluene to obtain a photosensitive resin composition (resist material). This photosensitive resin composition was applied to a thickness of 20 μm on an epoxy-glass printed wiring board having copper wiring using an applicator, and dried in an oven at 120 ° C. for 10 minutes.

The exposed portion of the copper wiring of the printed wiring board was exposed to a mask with a light exposure of 2000 mJ / cm ² using an exposure machine for printed wiring boards (Own HMW661). Subsequently, development was performed at 23 ° C. for 5 minutes using a 2.4% TMAH solution containing 20% isopropanol. After completion of the image development, the film was washed with water and dried by air blow, and then heated at 170 ° C. for 30 minutes to cure the resist film.

The resolution of the obtained resist pattern was 20 μmLZS. When a UL flame retardancy test was performed on the obtained printed wiring board, it was found to be flame retardant corresponding to V-0.

In addition, when a test was conducted by melting gold-tin-tin solder, which is a lead-free solder, in the developed part of the resist material, there was no problem with the pattern shape and film deterioration, and a solder that can be used with lead-free solder It was confirmed that it was a resist material.

100 parts by weight of the network-like polysilane obtained in Preparation Example 1, 100 parts by weight of TSR-1650, 10 parts by weight of TAZ_1110, and BTT B1 5 parts by weight was dissolved in 125 parts by weight of toluene to obtain a photosensitive resin composition. The photosensitive resin composition was applied on a silicon wafer substrate using a spin coater to a thickness of 2 μm, and dried in an oven at 120 ° C. for 10 minutes.

Next, this substrate was exposed and patterned at an exposure amount of 200 mJ / cm ² using an ArF stepper for semiconductor (manufactured by Nikon Corporation). Subsequently, development was performed at 23 ° C for 2 minutes using a 2.4% TMAH solution containing 20% isopropanol.

After the development was completed, the substrate was washed with water and dried by air blow, and the substrate was heated in an oven at 200 ° C. for 30 minutes to cure the insulating film. Observation of the pattern profile of the insulating film with an electron microscope revealed that the 0.5 μm LZS pattern was reproduced.

When the dielectric constant and the dielectric loss tangent of the insulating film fabricated as described above were measured, it was found that the dielectric constant was 2.80 and the dielectric loss tangent was 0.008 at 1 MHz, indicating that the insulating film had excellent electric characteristics. Therefore, it was found that the film has good performance as a semiconductor interlayer insulating film.

In this embodiment, an example in which the insulating material of the present invention is used for an interlayer insulating film is shown. However, the insulating material of the present invention is not limited to this, and the insulating film used for a multilayer printed circuit board and other uses. It can be used to form Industrial applicability

The resist material of the present invention has good self-flame retardancy without containing a halogen-based flame retardant. Also, since it contains polysilane as a main component, it has a low dielectric constant, and has good electrical properties as an insulating material.

Four

Claims

The scope of the claims

1. (A) a polysilane having a weight average molecular weight of 10,000 or more soluble in an organic solvent,

(B) a photoradical generator and an oxidizing agent,

(C) a silicone compound having a structure represented by the following general formula,

R ² R ⁴

R ¹ ~~ S i 0½ ~~ (-S io- _n ~ R ⁶

R ³ R ^R

(Wherein, R ¹ R ² , R ³ , R ⁴ , R ^5, and R ⁶ are an aliphatic hydrocarbon group which may be substituted with a halogen or daricidyl group having 1 to 10 carbon atoms, a carbon number of 6 A group selected from the group consisting of an aromatic hydrocarbon group which may be substituted with a halogen of 12 to 12 and an alkoxy group having 1 to 8 carbon atoms, which may be the same or different from each other; It contains at least two of the above alkoxy groups, wherein m and n are integers and satisfy m + n≥l.)

(D) A self-flammable resist material comprising a photosensitive resin composition containing an organic solvent.

2. A method of manufacturing a printed wiring board having a solder resist film formed on its surface,

Applying a resist material according to claim 1 onto a printed wiring board to form a solder resist film;

Selectively exposing and developing the solder resist film to expose a wiring portion to which solder is attached;

Five Heating the solder resist film after development to cure the solder resist film.

3. (A) polysilane having a weight average molecular weight of 10,000 or more soluble in an organic solvent,

(B) a photoradical generator and an oxidizing agent,

(Wherein, R ′, R ² , R ′ \ RR ⁵ and R ^{6 each} represent an aliphatic hydrocarbon group having 1 to 10 carbon atoms which may be substituted with a halogen or dalicidyl group; Selected from the group consisting of an aromatic hydrocarbon group optionally substituted with 12 halogens and an alkoxy group having 1 to 8 carbon atoms, which may be the same or different from each other; Contains at least two of the above alkoxy groups, m and n are integers, and satisfying m + n≥l.)

(D) An insulating material comprising a photosensitive resin composition containing an organic solvent.

4. A method for producing an insulating film, comprising applying the insulating material according to claim 3 onto a substrate, drying the substrate, and then heating and curing the substrate.