JP2003213019A - Prepreg and printed wiring board using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide prepregs having excellent dielectric characteristics, laser processability and flame retardancy and provide printed wiring boards. <P>SOLUTION: The prepregs are prepared by impregnating nonwoven fabrics made of organic fiber with a resin composition including cyanate resin and/or its prepolymer, epoxy resin, and inorganic fillers. The printed wiring boards is produced by laminating a metal foil clad on the prepreg and compressing the resultant laminate with heat. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a prepreg and a printed wiring board using the same.

[0002]

2. Description of the Related Art In the field of semiconductors, due to the progress of high-density mounting technology, a trend is progressing to shift semiconductor elements from conventional surface mounting to area mounting. New packages such as a ball grid array (BGA) and a chip scale package (CSP) have been introduced and are increasing in number to cope with such high-density mounting technology. Therefore, a rigid substrate for an interposer has been receiving more attention than before, and a demand for a highly heat resistant and low thermal expansion substrate is increasing.

Furthermore, in recent years, with the demand for higher functionality of electronic equipment, high-density integration and high-density mounting of electronic components have been advanced. Therefore, the printed wiring boards and the like used for them, which are compatible with high-density mounting, are smaller and higher in density than ever before. As a measure for increasing the density of such printed wiring boards, build-up multilayer wiring boards are often used. In order to reduce the size and the density of the build-up multilayer wiring board, it is necessary to connect the layers with fine vias. Therefore, the via of the build-up multilayer wiring board is
It is formed by laser processing. However, laser processing is difficult with a prepreg made of glass cloth,
A uniform and fine via could not be formed. At the same time, there is a demand for speeding up of information processing equipment, and CPU clock frequencies are increasing. Therefore, it is required to increase the signal propagation speed, and in order to realize this, a printed wiring board having a low dielectric constant and a low dielectric loss tangent is required.

Further, resin members used for semiconductors are often required to have flame retardancy. In the past, in the case of an epoxy resin, it has been common to use a halogen-based flame retardant such as brominated epoxy in order to impart flame retardancy. However, halogen-containing compounds are being avoided from use due to problems such as dioxin generation. Therefore, a halogen-free flame-retardant system has been required, and phosphorus-based flame retardants such as phosphoric acid ester and red phosphorus have been investigated. However, these phosphorus-based flame retardants are liable to be hydrolyzed and have poor reactivity with a resin, so that there is a problem that solder heat resistance is lowered.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a prepreg and a printed wiring board which have excellent dielectric properties, laser processability and flame retardancy.

[0006]

These objects are achieved by the present invention described in (1) to (10) below. (1) A prepreg characterized in that a nonwoven fabric composed of organic fibers is impregnated with a resin composition containing a cyanate resin and / or its prepolymer, an epoxy resin, and an inorganic filler (2). The glass transition point of the resin that constitutes the fiber is
The prepreg according to (1) above, which has a temperature of 200 ° C. or higher. (3) The prepreg according to the above (1) or (2), wherein the resin constituting the organic fiber contains a wholly aromatic polyamide resin as a main component. (4) The prepreg according to any one of (1) to (3) above, wherein the resin constituting the organic fiber contains a wholly aromatic polyester resin as a main component. (5) The prepreg according to any of (1) to (4) above, wherein the cyanate resin and / or its prepolymer is a novolac type cyanate resin and / or its prepolymer. (6) The prepreg according to any one of (1) to (5) above, wherein the content of the cyanate resin and / or its prepolymer is 5 to 60% by weight of the total resin composition. (7) The prepreg according to any of (1) to (6) above, wherein the epoxy resin is an aryl alkylene type epoxy resin. (8) The prepreg according to any one of (1) to (7), wherein the inorganic filler is spherical fused silica having an average particle size of 2 μm or less. (9) The content of the inorganic filler is 3 of the total resin composition.
The prepreg according to any one of (1) to (8) above, which is 0 to 80% by weight. (10) A printed wiring board obtained by laminating a metal foil on the prepreg according to any one of the above (1) to (9) and heat-pressing.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The prepreg of the present invention and the printed wiring board using the same will be described in detail below.
The prepreg of the present invention is characterized in that a nonwoven fabric composed of organic fibers is impregnated with a resin composition containing a cyanate resin and / or a prepolymer thereof, an epoxy resin, and an inorganic filler. . The printed wiring board of the present invention is obtained by laminating a metal foil on the prepreg and heat-pressing it.

The prepreg will be described below. The prepreg of the present invention uses a cyanate resin and / or its prepolymer. As a result, when the prepreg of the present invention is used as a printed wiring board, high heat resistance and low thermal expansion can be achieved. The cyanate resin and / or its prepolymer can be obtained, for example, by reacting a cyanogen halide compound with phenols and, if necessary, prepolymerizing by a method such as heating.
Specific examples thereof include novolac type cyanate resin, bisphenol A type cyanate resin, bisphenol E type cyanate resin, and bisphenol type cyanate resin such as tetramethylbisphenol F type cyanate resin. Among these, novolac type cyanate resin is preferable. Thereby, the heat resistance can be improved by increasing the crosslink density and the flame retardancy of the resin composition and the like can be improved.
It is considered that the novolac type cyanate resin has a high proportion of benzene rings due to its structure and is easily carbonized.

As the novolac type cyanate resin, for example, the one represented by the formula (I) can be used.

[Chemical 1] The n of the novolac type cyanate resin represented by the formula (I) is not particularly limited, but is preferably 1 to 10 and particularly preferably 1 to 7. If the amount is less than this, the novolac type cyanate resin is likely to be crystallized, and the solubility in a general-purpose solvent is relatively lowered, so that handling may be difficult. On the other hand, if it is more than the above range, the crosslink density becomes too high, which may cause a phenomenon such as deterioration of water resistance and brittleness of a cured product.

The weight average molecular weight of the cyanate resin and / or its prepolymer is not particularly limited, but a weight average molecular weight of 500 to 4500 is preferable, and 600 is particularly preferable.
~ 3000 is preferred. If it is smaller than this, tackiness may occur when the prepreg is manufactured, and when the prepregs come into contact with each other, they may adhere to each other or the resin may be transferred. Also, if it is larger than this, the reaction becomes too fast, and if a copper-clad laminate is used, molding defects may occur,
The interlayer peel strength may decrease.

The content of the cyanate resin and / or the prepolymer thereof is not particularly limited, but is preferably 5 to 60% by weight, and particularly preferably 10 to 50% by weight based on the entire resin composition. If the content of the cyanate resin and / or its prepolymer is less than the lower limit value, the heat resistance and the effect of low thermal expansion may decrease, and if the content exceeds the upper limit value, the crosslinking density increases and the free volume increases, resulting in moisture resistance. There is a case where the sex is deteriorated.

An epoxy resin is used in the prepreg of the present invention. Examples of the epoxy resin include a phenol novolac type epoxy resin, a bisphenol type epoxy resin, a naphthalene type epoxy resin, and an aryl alkylene type epoxy resin. Of these, aryl alkylene type epoxy resins are preferable. Thereby, the heat resistance of the moisture-absorbing solder can be improved.

The aryl alkylene type epoxy resin means an epoxy resin having one or more aryl alkylene groups in a repeating unit. Examples thereof include xylylene type epoxy resin and biphenyl dimethylene type epoxy resin. Among these, biphenyl dimethylene type epoxy resin is preferable. The biphenyl dimethylene type epoxy resin can be represented by, for example, the formula (II).

[Chemical 2] The n of the biphenyl dimethylene type epoxy resin represented by the formula (II) is not particularly limited, but is preferably 1 to 10 and particularly preferably 2 to 5. If the amount is less than the above range, the biphenyl dimethylene type epoxy resin is likely to be crystallized, and the solubility in a general-purpose solvent is relatively lowered, which may make the handling difficult. On the other hand, if the amount is larger than the above range, the fluidity of the resin is lowered, which may cause defective molding or the like.

Further, the above-mentioned cyanate resin and / or its prepolymer (particularly novolac type cyanate resin)
When a laminate is prepared using a combination of a phenol resin and an aryl alkylene type epoxy resin (particularly a biphenyl dimethylene type epoxy resin), excellent dimensional stability can be obtained.

The content of the epoxy resin is not particularly limited, but is preferably 1 to 55% by weight, and particularly preferably 2 to 40% by weight based on the entire resin composition. If the amount of the resin is less than the lower limit, the reactivity of the cyanate resin may decrease, or the moisture resistance of the obtained product may decrease, and if the amount of the resin exceeds the upper limit, the heat resistance may decrease. The weight average molecular weight of the epoxy resin is not particularly limited, but a weight average molecular weight of 500 to 20,000 is preferable, and particularly 800 to
15000 is preferable. If the weight average molecular weight is less than the above range, problems such as tackiness may occur in the prepreg, and if it is more than this range, impregnation into the base material during preparation of the prepreg is reduced, and a uniform product cannot be obtained. Problems may occur.

An inorganic filler is used in the prepreg of the present invention. As a result, low thermal expansion and improvement of flame retardancy can be achieved. Further, the elastic modulus can be improved by combining the above-mentioned cyanate resin and / or its prepolymer (particularly novolac type cyanate resin) with an inorganic filler. Examples of the inorganic filler include talc, alumina, glass, silica, mica and the like. Among these, silica is preferable, and fused silica is preferable because it has excellent low expansion properties. There are crushed and spherical shapes, but spherical silica is used to reduce the melt viscosity of the resin composition in order to ensure the impregnation into the glass substrate.
The usage method according to the purpose is adopted.

The average particle size of the inorganic filler is not particularly limited, but is preferably 0.01 to 5 μm, particularly 0.2 to
2 μm is preferable. If the particle size of the inorganic filler is less than the lower limit value, the viscosity of the varnish increases, which may affect workability during prepreg production. If the amount exceeds the upper limit, phenomena such as sedimentation of the inorganic filler may occur in the varnish. Further, spherical fused silica having an average particle diameter of 5 μm or less is preferable, and spherical fused silica having an average particle diameter of 0.01 to 2 μm is particularly preferable. Thereby, the filling property of the inorganic filler can be improved. The content of the inorganic filler is preferably 30 to 80% by weight of the entire resin composition,
Particularly, 40 to 70% by weight is preferable. When the inorganic filler is within the above range, low thermal expansion and low water absorption can be achieved.

The prepreg of the present invention is not particularly limited, but it is preferable to further use a phenol resin as a resin component. As a result, the reactivity of the cyanate resin and / or its prepolymer can be improved, which improves the moldability of the laminate. Examples of the phenol resin include novolac type phenol resin, resol type phenol resin, and aryl alkylene type phenol resin. Among these, the aryl alkylene type phenol resin is preferable. As a result, the heat resistance of the moisture-absorbing solder can be further improved.

Examples of the aryl alkylene type phenol resin include xylylene type phenol resin and biphenyl dimethylene type phenol resin. Biphenyl dimethylene type phenol resin is represented by the formula (II
I) can be shown.

[Chemical 3] N of the biphenyl dimethylene type phenol resin represented by the formula (III) is not particularly limited, but is preferably 1 to 12, and particularly preferably 2 to 8. If it is less than this range, the heat resistance may decrease. On the other hand, if the amount is larger than the above range, the compatibility with other resins is deteriorated and the workability may be deteriorated, which is not preferable.

The combination of the above-mentioned cyanate resin and / or its prepolymer (particularly novolac type cyanate resin) and the arylalkylene type phenol resin can control the crosslink density and improve the adhesion between the metal and the resin. .

The content of the phenolic resin is not particularly limited, but is preferably 1 to 55% by weight, and particularly preferably 5 to 40% by weight based on the entire resin composition. If the phenol resin is less than the lower limit value, the heat resistance may decrease, and if it exceeds the upper limit value, the low thermal expansion property may be impaired. The weight average molecular weight of the phenol resin is not particularly limited, but a weight average molecular weight of 400 to 18,000 is preferable, and 500 to 15,000 is particularly preferable. If the weight average molecular weight is less than the above range, problems such as tackiness may occur in the prepreg, and if it is more than this range, impregnation into the base material during preparation of the prepreg is reduced, and a uniform product cannot be obtained. Problems may occur.

In the prepreg of the present invention, a part of the above cyanate resin and / or its prepolymer, epoxy resin and phenol resin is another thermosetting resin such as vinyl ester resin and melamine resin, phenoxy resin, polyimide resin and polyamide. You may use together with thermoplastic resins, such as an imide resin, a polyphenylene oxide resin, and a polyether sulfone resin.

The prepreg of the present invention is not particularly limited, but it is preferable to use a coupling agent. The coupling agent improves the wettability of the interface between the resin and the inorganic filler, so that the resin and the filler are uniformly fixed to the substrate, and the heat resistance, especially the solder heat resistance after moisture absorption, is improved. Compound. As the coupling agent, any commonly used one can be used, and among them, one or more selected from epoxysilane coupling agents, titanate coupling agents, aminosilane coupling agents and silicone oil type coupling agents can be used. It is preferable to use a coupling agent in terms of high wettability with the interface of the inorganic filler and improvement in heat resistance. In the present invention, the coupling agent content is preferably 0.05% by weight or more and 3% by weight or less with respect to the inorganic filler. If it is less than this, the filler may not be sufficiently covered and sufficient heat resistance may not be obtained, and if it is more than this, the reaction is affected and the bending strength etc. decreases, so use within this range desirable.

In the prepreg of the present invention, a curing accelerator may be used if necessary. A well-known thing can be used as a hardening accelerator. For example, organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonatocobalt (II) and trisacetylacetonatocobalt (III), triethylamine, tributylamine, diazabicyclo [2,2]. 2,2] octane and other tertiary amines, 2-phenyl-4-methylimidazole, 2-ethyl-4-ethylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxy Examples include imidazoles, imidazoles such as 2-phenyl-4,5-dihydroxyimidazole, phenol compounds such as phenol, bisphenol A, and nonylpheno, organic acids such as acetic acid, benzoic acid, salicylic acid, and paratoluenesulfonic acid, or a mixture thereof. To be

In the prepreg of the present invention, if necessary,
Additives other than the above components can be added. A non-woven fabric composed of organic fibers described below is impregnated with a resin composition composed of each of these resins and each additive.

In the prepreg of the present invention, the above-mentioned resin composition is impregnated into a nonwoven fabric composed of organic fibers. Examples of the resin constituting the organic fiber include aromatic polyamide resin, polyamide resin, aromatic polyester resin, polyester resin, polyimide resin, fluororesin and the like. Among these, it is preferable to use, as a main component, at least one resin selected from aromatic polyester resins (particularly wholly aromatic polyester resins) and aromatic polyamide resins (particularly wholly aromatic polyamide resins). Thereby, when the prepreg is used as a printed wiring board, the laser processability can be improved. Further, an aromatic polyester resin (wholly aromatic polyester resin) is particularly preferable. Thereby, the electrical characteristics (dielectric characteristics) of the prepreg can be further improved.

The glass transition point of the resin constituting the organic fiber is not particularly limited, but is preferably 200 ° C. or higher,
Particularly, 250 to 400 ° C. is preferable. If the glass transition point is less than the lower limit value, flip-chip mountability may deteriorate.

Examples of the method of impregnating the base material with the resin composition include a method of immersing the base material in a resin varnish, a method of coating with a coater, and a method of spraying. Among these, the method of immersing the base material in the resin varnish is preferable. Thereby, the impregnation property of the resin composition on the substrate can be improved. In addition,
When dipping the base material in the resin varnish, ordinary impregnation coating equipment can be used.

The solvent used for the resin varnish preferably has good solubility in the resin composition, but a poor solvent may be used within a range that does not adversely affect the resin composition. Examples of the solvent exhibiting good solubility include acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclopentanone, cyclohexanone, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like. The solid content of the resin varnish is not particularly limited, but the solid content of the resin composition is preferably 30 to 80% by weight, and particularly preferably 40 to 70% by weight. This can improve the impregnation property of the resin varnish into the base material. The base material is impregnated with the resin composition at a predetermined temperature, for example 90
A prepreg can be obtained by drying at ~ 180 ° C.

Next, the printed wiring board will be described.
The printed wiring board of the present invention is obtained by laminating a metal foil on the above prepreg and heat-pressing it. This makes it possible to obtain a printed wiring board excellent in heat resistance, low expansion and flame retardancy. When using one prepreg, overlay metal foil on both upper and lower surfaces or on one side. Also, two or more prepregs can be laminated. Prepreg 2
When laminating one or more sheets, a metal foil or film is laminated on the outermost upper and lower surfaces or one side of the laminated prepreg. Next, a printed wiring board can be obtained by heat-press molding a prepreg and a metal foil that are stacked. The heating temperature is not particularly limited, but is 120
-220 degreeC is preferable and 150-200 degreeC is especially preferable. The pressure to be applied is not particularly limited, but is 1.5
-5 MPa is preferable, and 2-4 MPa is particularly preferable.
Further, if necessary, post-curing may be performed in a high temperature bath or the like at a temperature of 150 to 300 ° C.

Examples of the metal forming the metal foil include copper or copper-based alloys, aluminum or aluminum-based alloys, iron or iron-based alloys.

Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto.

Example 1 Preparation of resin varnish Novolac type cyanate resin (Lonza Japan Co., Ltd., Primaset PT-60, weight average molecular weight about 26)
00) 20 wt% (hereinafter abbreviated as%), biphenyl dimethylene type epoxy resin (Nippon Kayaku Co., Ltd., NC-3)
000P, epoxy equivalent 275) 11%, biphenyl dimethylene type phenol resin (Meiwa Kasei Co., ME
H-7851-S, hydroxyl equivalent 203) 9%, and an epoxysilane type coupling agent (manufactured by Nippon Unicar Co., Ltd., A-187) 0.3 parts by weight (hereinafter abbreviated as "part") are dissolved in methyl ethyl ketone at room temperature. , Spherical fused silica SF
P-10X (manufactured by Denki Kagaku Kogyo Co., Ltd., average particle size of 0.
3 μm) 10% and spherical fused silica SO-32R (manufactured by Admatechs Co., Ltd., average particle size 1.5 μm) 50%
Was added and stirred for 10 minutes using a high speed stirrer to prepare a resin varnish.

Manufacture of prepreg The above resin varnish was mixed with an aromatic polyester non-woven fabric (thickness 4
0 μm, Mitsubishi Paper Mills, G7-280T)
It was dried in a heating oven at 0 ° C. for 2 minutes to obtain a prepreg having a varnish solid content (ratio of resin and silica in the prepreg) of about 70%.

Manufacture of Printed Wiring Board Twelve sheets of the above prepreg are stacked, 18 μm copper foil is stacked on both sides, and heat and pressure molding is performed at a pressure of 4 MPa and a temperature of 200 ° C. for 2 hours to form a double-sided printed wiring board of 0.6 mm. A substrate for use was obtained. Substrates for printed wiring boards of other thicknesses were obtained by laminating the prepregs in the number corresponding thereto.

Example 2 The procedure of Example 1 was repeated, except that the following organic nonwoven fabric was used. Aromatic polyamide non-woven fabric (thickness 40
μm, manufactured by Oji Paper Co., Ltd., APT-22).

(Example 3) The same procedure as in Example 1 was carried out except that the compounding amounts were as follows. Novolak type cyanate resin (Primaset PT-60) 5%, biphenyl dimethylene type epoxy resin (NC-3000P) 20%,
Biphenyl dimethylene type phenol resin (MEH-78
51-S) 15% and epoxysilane type coupling agent (A-187) 0.3 parts are dissolved in methyl ethyl ketone at room temperature to obtain spherical fused silica (SFP-10X) 10%.
And 50% spherical fused silica (SO-32R) were added.

(Example 4) The same procedure as in Example 1 was carried out except that the compounding amounts were changed as follows. 30% of novolac type cyanate resin (Primaset PT-30), novolac type cyanate resin (Primaset PT-60) 30
%, Biphenyl dimethylene type epoxy resin (NC-30
00P) 5%, biphenyl dimethylene type phenol resin (MEH-7851-S) 5%, and epoxysilane type coupling agent (A-187) 0.3 parts are dissolved in methyl ethyl ketone at room temperature to obtain spherical fused silica (SFP). -10
X) 5% and spherical fused silica (SO-32R) 25%.

Example 5 The procedure of Example 1 was repeated except that the biphenyldimethylene type epoxy resin was changed as follows. Instead of biphenyl dimethylene type epoxy resin,
Novolac type epoxy resin (manufactured by Dainippon Ink and Chemicals, Inc., Epicron N-775, epoxy equivalent 19
0) was used.

Example 6 The procedure of Example 1 was repeated except that the biphenyl dimethylene type phenol resin was changed as follows. Novolak resin (Sumitomo Bakelite Co., Ltd., P
R-51714 and hydroxyl equivalent 103) were used.

Example 7 The same as Example 1 except that the spherical fused silica was changed as follows. FB-5S instead of spherical fused silica SFP-10X and SO-32R
DX (manufactured by Denki Kagaku Kogyo Co., Ltd.) was used.

Example 8 The procedure of Example 1 was repeated except that the compounding amounts were as follows. Novolac type cyanate resin (Primaset PT-60) 10%, biphenyl dimethylene type epoxy resin (NC-3000P) 6%,
Biphenyl dimethylene type phenol resin (MEH-78
51-S) 4% and epoxysilane type coupling agent (A-187) 0.3 parts are dissolved in methyl ethyl ketone at room temperature to obtain spherical fused silica (SFP-10X) 30% and spherical fused silica (SO-32R). 50% was added.

Example 9 The procedure of Example 1 was repeated, except that the compounding amounts were as follows. Novolac-type cyanate resin (Primaset PT-30) 15%, Novolac-type cyanate resin (Primaset PT-60) 25
%, Biphenyl dimethylene type epoxy resin (NC-30
00P) 17%, biphenyl dimethylene type phenol resin (MEH-7851-S) 13%, and epoxysilane type coupling agent (A-187) 0.3 parts are dissolved in methyl ethyl ketone at room temperature to obtain spherical fused silica (SFP). −
10X) 4% and spherical fused silica (SO-32R) 26
% Was added.

(Example 10) The procedure of Example 1 was repeated, except that the compounding amounts were as follows. Bisphenol A Cyanate Resin (Asahi Kasei Epoxy Co., Ltd., AroCy
B-30) 10%, biphenyl dimethylene type epoxy resin (NC-3000P) 6%, biphenyl dimethylene type phenol resin (MEH-7851-S) 4%, and epoxysilane type coupling agent (A-187) 0. .3
Parts are dissolved in methyl ethyl ketone at room temperature to obtain spherical fused silica (SFP-10X) 30% and spherical fused silica (S
O-32R) 50% was added.

(Comparative Example 1) The same procedure as in Example 1 was carried out except that the compounding amounts were as follows. Biphenyl dimethylene type epoxy resin (NC-3000P) 23%, biphenyl dimethylene type phenol resin (MEH-7851-S)
17%, curing aid 2-methylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd., 2MZ) 0.4 parts, and epoxysilane type coupling agent (A-187) 0.3 parts were dissolved in methyl ethyl ketone at room temperature to give a spherical shape. Fused silica (SFP-1
0X) 10% and spherical fused silica (SO-32R) 5
0% was added.

(Comparative Example 2) The same procedure as in Example 1 was carried out except that the compounding amounts were as follows. Novolac type cyanate resin (Primaset PT-60) 55%, Biphenyl dimethylene type phenol resin (MEH-7851-S)
5%, and epoxy silane type coupling agent (A-18
7) 0.3 part was dissolved in methyl ethyl ketone at room temperature, and 5% spherical fused silica (SFP-10X) and 35% spherical fused silica (SO-32R) were added.

(Comparative Example 3) The procedure of Example 1 was repeated, except that the compounding amounts were as follows. Novolac type cyanate resin (Primaset PT-60) 50%, biphenyl dimethylene type epoxy resin (NC-3000P) 28
%, Biphenyl dimethylene type phenol resin (MEH-
7851-S) 22% was added.

Comparative Example 4 The procedure of Example 1 was repeated except that glass fiber (50 μm in thickness, manufactured by Nitto Boseki Co., Ltd., WEA-1080) was used in place of the aromatic polyester nonwoven fabric.

The multilayer printed wiring boards obtained in Examples and Comparative Examples were evaluated as follows. Evaluation items,
It is shown together with the evaluation method. The results obtained are shown in Table 1. A double-sided multilayer printed wiring board having a glass transition temperature thickness of 0.6 mm was entirely etched, a test piece of 10 mm × 60 mm was cut out from the obtained laminated board, and a dynamic viscoelasticity measuring device DMA983 manufactured by TA Instruments was used. Heat up at 3 ° C / min,
The peak position of tan δ was taken as the glass transition temperature.

A double-sided multilayer printed wiring board having a dielectric constant and a dielectric loss tangent thickness of 1.0 mm was entirely etched to obtain a laminate of 97 mm × 25 mm and 53 mm.
mm × 25 mm and 37 mm × 25 mm test pieces were cut out and the relative permittivity and the dielectric loss tangent were measured by the triplate line resonance method.

According to the flame retardant UL-94 standard, a 1.0 mm thick test piece was measured by the vertical method.

Water absorption A double-sided multilayer printed wiring board having a thickness of 0.6 mm was entirely etched, and a test piece of 50 mm × 50 mm was cut out from the obtained laminated board and measured according to JIS6481.

Laser Machinability A double-sided multilayer printed wiring board having a thickness of 0.05 mm was completely etched, the obtained laminated board was processed with a UV YAG laser (manufactured by Mitsubishi Electric), and the upper part and the cross section were observed under a microscope.

Moisture absorption solder heat resistance 50 mm x 50 m from a double-sided copper clad laminate having a thickness of 0.6 mm
A test piece was prepared by cutting out to m and performing half-face etching according to JIS6481. After treating with a pressure cooker at 125 ° C., the copper foil surface was floated down in a soldering bath at 260 ° C., and the treatment time for generating blisters after 180 seconds was measured.

A double-sided copper-clad laminate having a coefficient of expansion of 1.2 mm in thickness is entirely etched,
A test piece of 4 mm × 4 mm was cut out from the obtained laminated plate, and the linear expansion coefficient in the longitudinal and lateral directions (X and Y directions) was measured at 5 ° C./min using TMA.

[0055]

[Table 1]

As is apparent from the table, Examples 1 to 10 are
It had a low dielectric constant and was excellent in laser processability and flame retardancy. Further, in Examples 1, 2, 5 to 8 and 10, the expansion coefficient was particularly low in the vertical direction. In addition, Examples 1 to 3 were particularly excellent in moisture absorption solder heat resistance.

[0057]

According to the present invention, it is possible to obtain a prepreg and a printed wiring board having excellent dielectric properties, laser processability and flame retardancy. Further, when a specific epoxy resin is used, a prepreg and a printed wiring board which are particularly excellent in moisture absorption solder heat resistance can be obtained. Moreover, when a specific inorganic filler is used, a prepreg and a printed wiring board having a particularly low expansion coefficient can be obtained.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C08L 79/00 C08L 79/00 Z H05K 1/03 610 H05K 1/03 610L 610R 610U (72) Inventor Arai Masataka 2-5-8 Higashi-Shinagawa, Shinagawa-ku, Tokyo F-term within Sumitomo Bakelite Co., Ltd. (reference) 4F072 AA01 AA02 AA07 AB05 AB06 AB29 AD23 AF01 AF06 AG03 AL13 4F100 AA20B AB01A AB33A AK32B AK53B AL05B BA02 CA23B DE04B01 DG01B23BDH04B01 JL01 4J002 CC29X CD00W CE00X DE146 DJ016 DJ046 DL006 FA086 FD016

Claims (10)

[Claims] 1. A prepreg obtained by impregnating a nonwoven fabric made of organic fibers with a resin composition containing a cyanate resin and / or a prepolymer thereof, an epoxy resin, and an inorganic filler. 2. The prepreg according to claim 1, wherein the resin constituting the organic fiber has a glass transition point of 200 ° C. or higher. 3. The prepreg according to claim 1, wherein the resin forming the organic fiber contains a wholly aromatic polyamide resin as a main component. 4. The resin that constitutes the organic fiber contains a wholly aromatic polyester resin as a main component.
Or the prepreg described in 2. 5. The prepreg according to claim 1, wherein the cyanate resin and / or its prepolymer is a novolac type cyanate resin and / or its prepolymer. 6. The prepreg according to claim 1, wherein the content of the cyanate resin and / or its prepolymer is 5 to 60% by weight based on the whole resin composition. 7. The prepreg according to claim 1, wherein the epoxy resin is an aryl alkylene type epoxy resin. 8. The prepreg according to claim 1, wherein the inorganic filler is spherical fused silica having an average particle size of 2 μm or less. 9. The prepreg according to claim 1, wherein the content of the inorganic filler is 30 to 80% by weight of the whole resin composition. 10. A printed wiring board obtained by laminating a metal foil on the prepreg according to claim 1 and heat-pressing it.