WO2009142192A1

WO2009142192A1 - Laminate, metal-foil-clad laminate, circuit board, and circuit board for led mounting

Info

Publication number: WO2009142192A1
Application number: PCT/JP2009/059169
Authority: WO
Inventors: 隆之鈴江; 明義野末
Original assignee: パナソニック電工株式会社
Priority date: 2008-05-19
Filing date: 2009-05-19
Publication date: 2009-11-26

Abstract

A laminate which comprises: a core material layer obtained by impregnating a nonwoven fibrous base with a thermosetting resin composition; and surface material layers respectively laminated to both surfaces of the core material layer. The thermosetting resin composition comprises 100 parts by volume of a thermosetting resin and 80-150 parts by volume of an inorganic filler. The inorganic filler comprises (A) gibbsite-form aluminum hydroxide particles having an average particle diameter (D₅₀) of 2-15 µm, (B) at least one inorganic ingredient selected from a group consisting of boehmite particles having an average particle diameter (D₅₀) of 2-15 µm and inorganic particles which have an average particle diameter (D₅₀) of 2-15 µm and which contain crystal water having a release initiation temperature of 400°C or higher or contain no crystal water, and (C) aluminum oxide particles having an average particle diameter (D₅₀) of 1.5 µm or smaller, the proportion of (A) the gibbsite-form aluminum hydroxide particles to (B) the at least one inorganic ingredient selected from a group consisting of the boehmite particles and the inorganic particles to (C) the aluminum oxide particles (ratio by volume) being 1:(0.1-1):(0.1-1).

Description

Laminated board, metal foil-clad laminated board, circuit board and circuit board for LED mounting

The present invention relates to a laminated board used in the field of circuit boards for various electronic devices, and particularly excellent in heat dissipation, and a metal foil-clad laminated board manufactured using the laminated board, a circuit board, and an LED The present invention relates to a circuit board for mounting.

As a typical laminate used for a printed circuit board for electronic equipment, a laminate called FR-4 obtained by laminating a prepreg in which a glass cloth is impregnated with a resin component such as an epoxy resin is used. Widely used. The name FR-4 is a classification according to a standard by NEMA (National Electrical Manufactures Association) in the United States. This FR-4 type laminate has the disadvantage of poor punchability and drillability. As a printed wiring board capable of solving such drawbacks, a layer in which a nonwoven fabric is impregnated with a resin component is used as a core material layer, and both surfaces of the core material layer are impregnated with a glass cloth as a surface layer, respectively. There is known a composite laminate called a CEM-3 type constituted by laminating layers.

For example, Patent Document 1 listed below discloses a resin-impregnated core obtained by impregnating a nonwoven fabric and / or paper with a resin varnish as a composite laminate having high interlaminar adhesive strength and excellent alkali resistance, heat resistance, and punchability. A composite laminate is proposed in which a resin-impregnated surface layer material obtained by impregnating a glass cloth with a resin varnish is adhered to both surfaces of a material, and a metal foil is further adhered. In this composite laminate, the resin varnish used for the core contains a filler that combines talc and aluminum hydroxide, and the blending ratio of talc and aluminum hydroxide is 0.15 to 0.65: It is described that aluminum hydroxide is boehmite type.

Further, for example, in Patent Document 2 below, as a composite laminate having excellent thermal stability and thermal stability, it is composed of a surface layer composed of a resin-impregnated glass woven fabric and an intermediate layer composed of a curable resin-impregnated glass nonwoven fabric. Laminated materials for printed circuit boards have been proposed. In this laminate, the intermediate layer has a molecular formula of Al ₂ O ₃ .nH ₂ O (wherein n is greater than 2.6 and in an amount of 200% to 275% by weight based on the resin in the intermediate layer) It contains aluminum hydroxide (having a value less than 2.9).

Furthermore, in recent years, with the progress of miniaturization of electronic devices, electronic components mounted on printed wiring boards have been mounted with high density, and the mounted electronic components are required to have heat dissipation. Multiple LEDs (Light Emitting Diodes) may be mounted. As a substrate used in such an application, a conventional laminated plate has a problem that heat dissipation is insufficient. In addition, as a mounting method, reflow solder is mainstream, and in particular, reflow solder using lead-free solder that requires high-temperature reflow processing is mainstream for the purpose of reducing the environmental load. In such a reflow soldering process using lead-free solder, high heat resistance is required to suppress the generation of blisters and the like. Furthermore, maintaining drill workability is also required. From the viewpoint of safety, flame retardancy that satisfies the V-0 level in UL-94 is also required.

Japanese Patent Laid-Open No. 62-173245 JP 2001-508002 A

The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a laminate having excellent thermal conductivity, heat resistance, drilling workability, and flame retardancy.

One aspect of the present invention is that a core layer obtained by impregnating a non-woven fiber base material with a thermosetting resin composition and a surface layer laminated on both surfaces of the core layer are laminated and integrated. The thermosetting resin composition contains 80 to 150 parts by volume of an inorganic filler with respect to 100 parts by volume of the thermosetting resin, and the inorganic filler contains (A) 2 gibbsite type aluminum hydroxide particles having an average particle size of ~ 15 [mu] m to _{(D 50), (B)} boehmite particles having an average particle size of 2 ~ 15μm _{(D 50),} and 2 to an average particle size of 15 [mu] m _{(D 50)} At least one inorganic component selected from the group consisting of inorganic particles that contain crystallization water having a freezing start temperature of 400 ° C. or higher and that do not contain crystallization water, and (C) an average particle of 1.5 μm or less Aluminum oxide having a diameter (D ₅₀ ) A combination of at least one inorganic component (B) selected from the group consisting of the gibbsite-type aluminum hydroxide particles (A), the boehmite particles, and the inorganic particles, and the aluminum oxide particles (C). The present invention relates to a laminate having a ratio (volume ratio) of 1: 0.1 to 1: 0.1 to 1.

Another aspect of the present invention relates to a metal foil-clad laminate in which a metal foil is stretched on at least one surface of the laminate, and a circuit board obtained by forming a circuit in the metal foil-clad laminate, Further, the present invention relates to an LED mounting circuit board comprising the circuit board.

The objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

FIG. 1 is a schematic cross-sectional view of a composite laminate according to an embodiment of the present invention. FIG. 2 is a schematic configuration diagram of the LED backlight unit.

The laminate according to the present invention comprises a core material layer obtained by impregnating a non-woven fiber base material with a thermosetting resin composition, and a surface material layer laminated on both surfaces of the core material layer. It is obtained by integrating.

[Thermosetting resin composition]
A preferred embodiment according to the present invention will be described first for a thermosetting resin composition.

According to the study by the present inventors, when aluminum hydroxide having excellent thermal conductivity is added in order to impart heat dissipation to the laminate, the heat dissipation of the laminate is improved. In addition, flame retardancy is also improved. However, when aluminum hydroxide is added too much, the heat resistance of the laminate is greatly lowered, and a problem that blisters and the like are likely to occur during solder reflow occurs. In addition, when aluminum oxide with excellent heat dissipation is blended in place of aluminum hydroxide, the wear of the drill blade during drilling is significant, and there is a problem that the drill blade must be replaced frequently, and flame retardancy There was a problem of declining. Further, when the amount of aluminum oxide is reduced in order to suppress wear of the drill blade, there is a problem that sufficient thermal conductivity cannot be obtained. Thus, it has been difficult to obtain a laminate that satisfies all of high thermal conductivity, high heat resistance, drilling workability, and high flame retardancy.

The thermosetting resin composition according to this embodiment contains 80 to 150 parts by volume of an inorganic filler with respect to 100 parts by volume of the thermosetting resin, and the inorganic filler contains (A) 2-15 μm average particles. Gibbsite-type aluminum hydroxide particles having a diameter (D ₅₀ ), (B) boehmite particles having an average particle diameter (D ₅₀ ) of 2 to 15 μm, and an average particle diameter (D ₅₀ ) of 2 to 15 μm At least one inorganic component selected from the group consisting of inorganic particles containing crystal water having a temperature of 400 ° C. or higher or not containing crystal water, and (C) an average particle diameter (D ₅₀ ) of 1.5 μm or less. At least one inorganic component (B) selected from the group consisting of the gibbsite-type aluminum hydroxide particles (A), the boehmite particles, and the inorganic particles. ) And the aluminum oxide particles (C) in a mixing ratio (volume ratio) of 1: 0.1 to 1: 0.1 to 1.

Specific examples of thermosetting resins include liquid thermosetting resins such as epoxy resins; radical polymerization thermosetting resins such as unsaturated polyester resins and vinyl ester resins; Moreover, a hardening | curing agent and a curing catalyst are mix | blended with a thermosetting resin as needed. Moreover, when using radical polymerization type thermosetting resin, you may mix | blend radical polymerizable monomers, such as styrene and a diallyl phthalate, etc. suitably as needed. In any case, in order to improve viscosity adjustment and productivity, a solvent may be blended as necessary.

The inorganic filler according to the present embodiment includes a group consisting of gibbsite-type aluminum hydroxide particles (A), boehmite particles, and inorganic particles that contain crystal water having a liberation start temperature of 400 ° C. or higher or no crystal water. At least one inorganic component (B) selected from the following and aluminum oxide particles (C).

The gibbsite-type aluminum hydroxide particles (A) are aluminum compounds represented by Al (OH) ₃ or Al ₂ O ₃ .3H ₂ O, and the laminate is thermally conductive, flame retardant, and drillable. Is a component that imparts a good balance.

The average particle diameter (D ₅₀ ) of the gibbsite type aluminum hydroxide particles (A) is 2 to 15 μm, preferably 3 to 10 μm. When the average particle diameter (D ₅₀ ) of the gibbsite type aluminum hydroxide particles (A) exceeds 15 μm, the drilling processability decreases, and when it is less than 2 μm, the thermal conductivity decreases and the productivity decreases. To do. The gibbsite-type aluminum hydroxide particles (A) include a first gibbsite-type aluminum hydroxide having an average particle diameter (D ₅₀ ) of 2 to 10 μm and a second gibbsite-type aluminum hydroxide particle (D ₅₀ ) of 10 to 15 μm. It is preferable to use a blend with Gibbsite type aluminum hydroxide from the viewpoint that heat dissipation is further improved by more densely filling the filler.

The average particle diameter (D ₅₀ ) in this embodiment is obtained by calculating the cumulative curve with the total volume of the powder group obtained by measurement with a laser diffraction particle size distribution measuring device as 100%, and the cumulative curve is 50%. Means the particle diameter of the point.

The inorganic component (B) is at least one selected from the group consisting of boehmite particles and inorganic particles that contain crystallization water having a freezing start temperature of 400 ° C. or higher or that do not have crystallization water.

The boehmite particle is an aluminum compound represented by (AlOOH) or (Al ₂ O ₃ .H ₂ O), and imparts thermal conductivity and flame retardancy without reducing the heat resistance of the laminate. It is.

The average particle size (D ₅₀ ) of the boehmite particles is 2 to 15 μm, preferably 3 to 10 μm. When the average particle diameter (D ₅₀ ) of the boehmite particles exceeds 15 μm, drill workability decreases, and when it is less than 2 μm, thermal conductivity decreases and productivity decreases.

Further, inorganic particles containing crystallization water having a liberation start temperature of 400 ° C. or higher or having no crystallization water are components that impart thermal conductivity and flame retardancy without lowering the heat resistance of the circuit board. .

Specific examples of the inorganic particles include inorganic oxides such as aluminum oxide (no crystal water), magnesium oxide (no crystal water), crystalline silica (no crystal water); boron nitride (no crystal water), aluminum nitride (crystals) Inorganic nitride such as silicon nitride (no crystal water); inorganic carbide such as silicon carbide (no crystal water); and talc (freezing start temperature 950 ° C.), calcined kaolin (no crystal water), clay (free Natural minerals such as a starting temperature of 500 to 1000 ° C.). These may be used alone or in combination of two or more. Among these, crystalline silica, talc, clay and the like are particularly preferable from the viewpoint of excellent thermal conductivity.

In addition, the freezing start temperature of crystal water can be measured using heating weight loss analysis (TGA) or suggestion scanning calorimetry (DSC).

The average particle diameter (D ₅₀ ) of the inorganic particles is 2 to 15 μm, preferably 3 to 10 μm. When the average particle diameter (D ₅₀ ) of the inorganic particles exceeds 15 μm, drill workability may be reduced.

Aluminum oxide particles (C) are components that impart high thermal conductivity to the resulting laminate. The average particle diameter (D ₅₀ ) of the aluminum oxide particles (C) is 1.5 μm or less, preferably 0.4 to 0.8 μm. When the average particle diameter of the aluminum oxide particles exceeds 1.5 μm, it becomes difficult to fill the laminated plate with a sufficient blending amount, and drill workability is also lowered. Moreover, when the average particle diameter of aluminum oxide is too small, there exists a possibility that the heat conductivity of a laminated board may become inadequate.

The mixing ratio (volume ratio) of the gibbsite type aluminum hydroxide particles (A), the inorganic component (B), and the aluminum oxide particles (C) is 1: 0.1 to 1: 0.1 to 1. Yes, preferably 1: 0.1 to 0.5: 0.1 to 0.5. When the blending amount of the inorganic component (B) exceeds 1 with respect to the blending amount 1 of the gibbsite type aluminum hydroxide particles (A), the drilling workability and heat dissipation of the resulting laminated plate are reduced. When it is less than 1, the heat resistance is lowered. Further, when the blending amount of the aluminum oxide particles (C) exceeds 1 with respect to the blending amount 1 of the gibbsite-type aluminum hydroxide particles (A), the drill workability is deteriorated. Reduces the thermal conductivity.

The blending ratio of the inorganic filler to 100 parts by volume of the thermosetting resin is 80 to 150 parts by volume, preferably 90 to 140 parts by volume, and more preferably 100 to 130 parts by volume. When the blending ratio of the inorganic filler is less than 80 parts by volume, the thermal conductivity of the resulting laminate is low, and when it exceeds 150 parts by volume, the drillability is lowered and the productivity of the laminate is increased. (Resin impregnation property, moldability) also decreases. In particular, when the blending ratio of the gibbsite type aluminum hydroxide particles (A) is too large, specifically when it exceeds 100 parts by volume, the heat resistance tends to decrease due to the generation of a large amount of crystal water. There is.

In addition, when the inorganic component (B) is a mixture of boehmite particles and inorganic particles containing crystal water having a liberation start temperature of 400 ° C. or higher or having no crystal water, compounding of inorganic particles The ratio is preferably 50% by volume or less, more preferably 30% by volume or less, and particularly preferably 20% by volume or less in the total amount of the inorganic filler.

The thermosetting resin composition includes an inorganic filler containing the above-described gibbsite type aluminum hydroxide particles (A), an inorganic component (B), and aluminum oxide particles (C) in a liquid thermosetting resin. It mix | blends and it prepares by the well-known preparation method of disperse | distributing each inorganic particle using a disper, a ball mill, a roll, etc. In addition, you may mix | blend the organic solvent for adjusting a viscosity, and various additives as needed.

[Core material layer]
Next, a prepreg for forming a core material layer (hereinafter, also referred to as a core material layer prepreg) using the thermosetting resin composition will be described.

The core material layer prepreg is made of a non-woven fiber base material such as glass nonwoven fabric, glass paper, synthetic resin nonwoven fabric, paper, and the like, and the above-described gibbsite type aluminum hydroxide particles (A), inorganic component (B), and aluminum oxide particles. It is obtained by impregnating a varnish containing a thermosetting resin composition in which an inorganic filler containing (C) is dispersed.

The type of the nonwoven fiber base material is not particularly limited, and examples thereof include glass nonwoven fabric, glass paper, synthetic resin nonwoven fabric using synthetic resin fibers such as aramid fiber, polyester fiber, nylon fiber, and paper. Since such a nonwoven fiber base material is coarser than a woven fiber base material, the drillability of the composite laminate is improved.

The thickness of the nonwoven fiber base material is not particularly limited, and is, for example, about 10 to 300 μm.

Specific examples of the thermosetting resin varnish for forming the core layer prepreg include, for example, epoxy resins; radical polymerization type thermosetting resins such as unsaturated polyester resins and vinyl ester resins; A resin varnish containing When an epoxy resin is used as the thermosetting resin, a curing agent or a curing catalyst is blended as necessary. Moreover, when using radical polymerization type thermosetting resin, you may mix | blend radical polymerizable monomers, such as styrene and a diallyl phthalate, etc. suitably as needed. In any case, a solvent may be blended as necessary to adjust the viscosity.

The core material layer prepreg is obtained by impregnating and semi-curing the above-mentioned thermosetting resin composition on the non-woven fiber base as described above. Specifically, the non-woven fiber base material is impregnated with the thermosetting resin composition, and the thermosetting resin composition impregnated into the fiber base material is dried by heating, whereby the thermosetting resin is brought into a semi-cured state. A core layer prepreg is obtained.

[Surface layer]
Next, a prepreg for forming a surface material layer (hereinafter also referred to as a surface material layer prepreg) will be described.

The surface layer prepreg is impregnated with a resin varnish in a woven fiber base material such as glass cloth (woven cloth) or synthetic fiber cloth (woven cloth) using synthetic fibers such as aramid fiber, polyester fiber, nylon fiber, etc. Can be obtained. Thus, the dimensional stability and heat resistance of the resulting composite laminate can be improved by using a woven fiber substrate for the surface layer.

As the resin varnish for forming the surface material layer prepreg, the same radical polymerization type thermosetting resin as epoxy resin, unsaturated polyester resin, vinyl ester resin, etc., used for the production of the core material layer prepreg is used. A resin varnish serving as a resin component may be used. In addition, in the resin varnish for forming the surface material layer prepreg, similarly to the resin varnish for forming the core material layer prepreg, various reaction initiators, curing agents, and fillers are appropriately blended as necessary. May be. Moreover, you may mix | blend a filler suitably as needed in the range which does not impair the effect of this invention.

As the thermosetting resin composition contained in the resin varnish to be impregnated into the woven fiber base material, it is preferable to use the same thermosetting resin composition as that used for forming the core material layer prepreg. That is, the inorganic filler contains 80 to 150 parts by volume with respect to 100 parts by volume of the thermosetting resin, and the inorganic filler contains gibbsite type aluminum hydroxide particles (A ₅₀ ) having an average particle diameter (D ₅₀ ) of 2 to 15 μm. ), Boehmite particles having an average particle diameter (D ₅₀ ) of 2 to 15 μm, and water of crystallization having an average particle diameter (D ₅₀ ) of 2 to 15 μm and a freezing start temperature of 400 ° C. or higher, or Containing at least one inorganic component (B) selected from the group consisting of inorganic particles not containing crystal water, and aluminum oxide particles (C) having an average particle size (D ₅₀ ) of 1.5 μm or less, Thermosetting resin in which the compounding ratio (volume ratio) of type aluminum hydroxide particles (A), inorganic component (B), and aluminum oxide particles (C) is 1: 0.1 to 1: 0.1 to 1 Composition It is preferable to use it.

[Laminated board]
A composite laminate 10 according to an embodiment of the present invention will be described with reference to FIG.

The composite laminate 10 has a layer configuration in which a core material layer 1 and a surface material layer 2 laminated on both surfaces of the core material layer 1 are laminated and integrated. And the metal foil 3 is further laminated | stacked on the surface layer, and the metal foil tension laminated board is comprised.

The core material layer 1 is composed of a nonwoven fiber base material 1a and a thermosetting resin composition 1b containing an inorganic filler, and the surface material layer 2 is composed of a woven fiber base material 2a and a resin composition 2b. It is composed of

The core material layer 1 is formed by impregnating a non-woven fiber base material 1a such as a glass nonwoven fabric or glass paper with a thermosetting resin composition 1b. The thermosetting resin composition 1b includes a gibbsite-type aluminum hydroxide particle (A) having an average particle diameter (D ₅₀ ) of 2 to 15 μm and an average particle diameter (D ₅₀ ) of 2 to 15 μm. At least 1 selected from the group consisting of boehmite particles having an average particle diameter (D ₅₀ ) of 2 to 15 μm, inorganic water particles containing crystal water having a release initiation temperature of 400 ° C. or higher, or having no crystal water. An inorganic filler containing a seed inorganic component (B) and aluminum oxide particles (C) having an average particle diameter (D ₅₀ ) of 1.5 μm or less is blended.

On the other hand, the surface material layer 2 is formed by impregnating a woven fiber base material 2a such as a glass cloth with a resin composition 2b.

And the surface material layer 2 is laminated | stacked on both surfaces of the core material layer 1, respectively, Furthermore, the metal foil 3 is laminated | stacked on the surface of the surface material layer 2, and metal foil is stretched by carrying out lamination molding of this laminated body. A composite laminate 10 is obtained. Each of the core material layer prepreg and the surface material layer prepreg may be a single layer or a plurality of layers, specifically 1 to 3 layers, and may be appropriately adjusted according to the purpose. The

Although it does not specifically limit as metal foil, Copper foil, aluminum foil, nickel foil, etc. can be used. The metal foil may be disposed on both surfaces or only on one surface. In addition, it may replace with metal foil and may arrange | position a release film on the surface which does not distribute metal foil, and heat-press-mold a laminated body.

A printed wiring board can be obtained by subjecting the composite laminate 10 thus formed to known wiring processing or through-hole processing using an additive method, a subtractive method, or the like.

At this time, in the composite laminate 10 of the present embodiment, the gibbsite type aluminum hydroxide particles (A) are blended in the resin composition constituting the core material layer 1, and the aluminum oxide particles having a small average particle size. Since a predetermined amount of (C) is blended, wear of the drill blade during drilling of the laminated plate can be suppressed. Therefore, the life of the drill can be extended. Moreover, even if a drilling process is applied to form a through hole, it is difficult to form irregularities on the inner surface of the hole to be formed, and the inner surface of the hole can be formed smoothly. For this reason, when through-holes are formed by plating the inner surface of the holes, high conduction reliability can be imparted to the through-holes. Moreover, the heat conductivity of a laminated board can be improved remarkably by mix | blending the aluminum oxide particle (C) excellent in heat conductivity. In addition, in order to mix | blend the aluminum oxide particle (C) of a small particle diameter, the drill workability of a laminated board is not reduced remarkably. Moreover, heat conductivity can be provided by mix | blending the said inorganic component (B), without reducing heat resistance and drill workability remarkably.

The composite laminated board excellent in thermal conductivity and drilling workability of this embodiment has high heat dissipation such as a printed wiring board of an LED backlight unit mounted on a liquid crystal display or a printed wiring board of LED lighting. It is preferably used for applications where properties are required.

Specifically, an LED backlight unit 20 mounted on a liquid crystal display as shown in the schematic top view of FIG. The LED backlight unit 20 in FIG. 2 is configured by arranging a large number of LED modules 23 each having a plurality of (three in FIG. 2) LEDs 22 mounted on a printed wiring board 21, and is disposed on the back of the liquid crystal panel. Therefore, it is used as a backlight for a liquid crystal display or the like. In the liquid crystal display of the type that has been widely used in the past, a cold cathode tube (CCFL) type backlight has been widely used as a backlight of the liquid crystal display, but in recent years, compared with a cold cathode tube type backlight. Since the color gamut can be widened, the image quality can be improved, the environmental load is small because mercury is not used, and the LED backlight unit as described above can be reduced in thickness. Is being actively developed.

LED modules generally consume more power than cold cathode tubes, and therefore generate a large amount of heat. By using the composite laminate of the present invention as the printed wiring board 21 that requires such high heat dissipation, the problem of heat dissipation is greatly improved. Therefore, the luminous efficiency of the LED can be improved.

The present invention will be described more specifically with reference to examples. In addition, this invention is not limited at all by the Example.

Example 1
<Manufacture of laminates>
Bisphenol A type epoxy to the resin and dicyandiamide (Dicy) thermosetting resin per 100 parts by volume of a thermosetting resin varnish containing a curing agent, gibbsite type aluminum hydroxide (manufactured by Sumitomo Chemical Co., Ltd., D ₅₀ : 5.4 μm) 35 parts by volume, Gibbsite type aluminum hydroxide (Sumitomo Chemical Co., Ltd., D ₅₀ : 12.6 μm) 35 parts by volume, boehmite (D ₅₀ : 5.5 μm) 15 parts by volume, and aluminum oxide ( 15 parts by volume of Sumitomo Chemical Co., Ltd., D ₅₀ : 0.76 μm) was blended and dispersed uniformly. The resin varnish blended with the filler was impregnated into a glass nonwoven fabric (glass nonwoven fabric manufactured by Vilene Co., Ltd.) having a basis weight of 60 g / m ² and a thickness of 400 μm to obtain a core layer prepreg.

On the other hand, a glass cloth (woven fabric) having a basis weight of 200 g / m ² and a thickness of 180 μm (7628 manufactured by Nittobo Co., Ltd.) was impregnated with a curing agent-containing epoxy resin varnish without adding a filler. A material layer prepreg was obtained.

And two core material layer prepregs were stacked, and a laminate was obtained by sequentially placing one surface material layer prepreg and a copper foil having a thickness of 0.018 mm on both outer surfaces thereof. The laminate was sandwiched between two metal plates and heat molded under the conditions of a temperature of 180 ° C. and a pressure of 30 kg / m ² to obtain a 1.0 mm thick copper foil-clad composite laminate.

The obtained copper foil-clad composite laminate was evaluated for thermal conductivity, 220 ° C oven heat resistance test, 260 ° C solder heat resistance test, pressure cooker test (PCT), drill wear rate, and flame resistance according to the following evaluation methods. did. The results are shown in Table 1 below. In Tables 1 and 2 below, the values shown in parentheses in each Example and each Comparative Example are the ratios of boehmite particles, inorganic particles or aluminum oxide particles to 1 part by volume of gibbsite type aluminum hydroxide particles. To express.

<Thermal conductivity>
The density of the obtained copper foil-clad composite laminate was measured by an underwater substitution method, the specific heat was measured by DSC (differential scanning calorimetry), and the thermal diffusivity was measured by a laser flash method.

And thermal conductivity was computed from the following formula | equation.
Thermal conductivity (W / m · K) = Density (kg / m ³ ) x Specific heat (kJ / kg · K) x Thermal diffusivity (m ² / S) x 1000

<220 ° C oven heat resistance test>
Using the obtained copper foil-clad composite laminate, when a test piece produced according to JIS C 6481 was treated for 1 hour in a thermostat with an air circulation device set at 220 ° C., the copper foil and the laminate were The case where no blistering or peeling occurred was judged as “excellent”, and the case where blistering or peeling occurred was judged as “poor”.

<260 ° C solder heat resistance test>
When the test piece produced according to JIS C 6481 was immersed in a 260 ° C. solder bath using the obtained copper foil-clad composite laminate, the copper foil and laminate were not blistered or peeled off. The maximum time was identified.

<Pressure cooker test (PCT)>
Using the obtained copper foil-clad composite laminate, a test piece prepared according to JIS C 6481 was treated in an autoclave at 121 ° C. and 2 atmospheres for 60 minutes. And when the processed laminated board was dipped in a solder bath at 260 ° C., the maximum time when no blistering or peeling occurred on the copper foil and the laminated board was specified.

<Drill wear rate>
Three layers of the obtained laminates were stacked, and the wear rate of the drill blade after drilling 3000 holes at 60000 rpm with a drill (drill diameter 0.5 mm, deflection angle 35 °) before drilling It was evaluated by the ratio (percentage) of (area) of the drill blade worn by drilling to the size (area) of the drill blade.

<Flame retardance>
The obtained copper foil-clad composite laminate is cut into a predetermined size, and UL
A combustion test was conducted according to the 94 combustion test method, and the determination was made.

(Examples 2 to 7 and Comparative Examples 1 to 14)
In the production of the core material layer prepreg, a laminate was obtained and evaluated in the same manner as in Example 1 except that the composition of the resin composition was changed as shown in Table 1 or Table 2. The results of Example 1 and Examples 2 to 7 are shown in Table 1, and the results of Comparative Examples 1 to 14 are shown in Table 2.

In Examples 4 and 6, talc (produced by Fuji Talc Kogyo Co., Ltd.) having an average particle size (D ₅₀ ) of 6.5 μm, and in Comparative Example 8, oxidation having an average particle size (D ₅₀ ) of 0.76 μm. Aluminum (Sumitomo Chemical Co., Ltd.) was used.

From the results shown in Tables 1 and 2, the copper foil-clad composite laminates of Examples 1 to 7 according to the present invention all have a high thermal conductivity of 0.97 W / m · K or more, and are heat resistant. Both drill wear resistance and flame retardancy were high. On the other hand, the copper foil-clad composite laminate of Comparative Example 8 using aluminum oxide having a general particle size is compared with the copper foil-clad composite laminate of Example 1 using aluminum oxide having a fine particle size, Drill wear resistance was very poor. Moreover, when Example 2 and Comparative Example 4 are compared, it can be seen that sufficient thermal conductivity cannot be obtained unless aluminum oxide is blended. In Comparative Example 10 and Comparative Example 11 in which no gibbsite type aluminum hydroxide was blended, the flame retardancy was at the V-1 level. Moreover, in the comparative example 12 whose total amount of an inorganic filler is 70 mass parts with respect to 100 mass parts of epoxy resins, thermal conductivity was remarkably low. Further, Comparative Examples 2, 3, 6, 7, and 14 containing no boehmite had low oven heat resistance and solder heat resistance.

(Examples 8 to 16 and Comparative Examples 15 to 27)
In the production of the core material layer prepreg, a laminate was obtained and evaluated in the same manner as in Example 1 except that the composition of the resin composition was changed as shown in Table 3 or Table 4. The results of Examples 8 to 16 are shown in Table 3, and the results of Comparative Examples 15 to 27 are shown in Table 4.

In Example 14, the average particle diameter _(D 50) 6.5 [mu] m of crystalline silica, in Example 15, (manufactured by Nippon Light Metal Co.) average particle size _(D 50) of magnesium oxide 6.5 [mu] m, implementation In Example 16, aluminum nitride (manufactured by Furukawa Electronics Co., Ltd.) having an average particle diameter (D ₅₀ ) of 6.6 μm, and in Comparative Examples 20 and 22, aluminum oxide having an average particle diameter (D ₅₀ ) of 4 μm (Sumitomo Chemical Co., Ltd.) Made).

From the results shown in Table 3, the laminated plates of Examples 8 to 16 according to the present invention all had high thermal conductivity and excellent oven heat resistance and PCT heat resistance. Also, the drill wear rate was low, and the flame retardancy was V-0 level. On the other hand, from the results shown in Table 4, the heat resistance decreased when a large amount of gibbsite-type aluminum hydroxide was contained as in the laminates of Comparative Examples 16 and 17. Further, in the laminates of Comparative Examples 18 to 20 containing only talc and aluminum oxide, the flame retardancy was at the V-1 level. Moreover, it replaced with the aluminum oxide with an average particle diameter of 0.76 micrometer of Example 8, and the drill abrasion property was remarkably high in the comparative example 22 using the aluminum oxide with an average particle diameter of 4 micrometers. In addition, the wear of the drill was also extremely high in the laminate of Comparative Example 23 having a high talc compounding ratio of 1.4 to 1 part by volume of gibbsite type aluminum hydroxide. Further, the laminate of Comparative Example 24 containing no gibbsite-type aluminum hydroxide also had a high drill wear rate, and the flame retardancy was at the V-1 level. Further, in the laminate of Comparative Example 25 having a high compounding ratio of 0.76 μm of aluminum oxide with an average particle diameter of 0.76 μm per 1 part by volume of gibbsite-type aluminum hydroxide, the drill wear is remarkably high and flame retardancy is also achieved. Was also at the V-1 level.

As described above, according to one aspect of the present invention, the core layer obtained by impregnating the non-woven fiber base material with the thermosetting resin composition and the both surfaces of the core layer are laminated. A laminate in which a surface layer is laminated and integrated, wherein the thermosetting resin composition contains 80 to 150 parts by volume of an inorganic filler with respect to 100 parts by volume of the thermosetting resin, and the inorganic filling The material comprises (A) gibbsite type aluminum hydroxide particles having an average particle size (D ₅₀ ) of 2 to 15 μm, (B) boehmite particles having an average particle size (D ₅₀ ) of 2 to 15 μm, and 2 to 15 μm. At least one inorganic component selected from the group consisting of inorganic particles having an average particle size (D ₅₀ ), containing crystallization water having a liberation start temperature of 400 ° C. or higher, or containing no crystallization water, and (C) Average particle diameter of 1.5 μm or less (D ₅₀ ), At least one inorganic component (B) selected from the group consisting of the gibbsite type aluminum hydroxide particles (A), the boehmite particles, and the inorganic particles, and the aluminum oxide particles (C). ) With a mixing ratio (volume ratio) of 1: 0.1 to 1: 0.1 to 1.

According to the above configuration, a laminate having excellent thermal conductivity, heat resistance, drill workability, and flame retardancy can be obtained. In order to improve thermal conductivity, drilling workability will fall remarkably when a general aluminum oxide is mix | blended with a thermosetting resin composition. This is because aluminum oxide has a high hardness. In the present invention, by adding aluminum oxide having a very small particle diameter at a predetermined ratio, the heat resistance is remarkably improved without reducing drill workability.

Gibbsite-type aluminum hydroxide (Al (OH) ₃ or Al ₂ O ₃ .3H ₂ O), which is an aluminum compound, is a component that imparts heat conductivity, drill workability, and flame retardancy in a well-balanced manner. Gibbsite type aluminum hydroxide has a characteristic of releasing crystal water at about 200 to 230 ° C., and therefore has a particularly high effect of imparting flame retardancy. However, when there are too many compounding ratios, it becomes a cause of generating a blister etc. at the time of solder reflow.

Furthermore, boehmite (AlOOH), which is an aluminum-based compound, contributes to imparting thermal conductivity and heat resistance to the laminate. Boehmite is potentially superior in heat resistance to gibbsite type aluminum hydroxide because it has the potential to release crystal water at about 450-500 ° C. In addition, it exhibits flame retardancy at high temperatures.

In addition, inorganic particles containing crystallization water having a release start temperature of 400 ° C. or higher or not containing crystallization water similarly contribute to imparting thermal conductivity and heat resistance to the laminate. By blending such inorganic particles, it is possible to suppress the occurrence of blisters during reflow soldering of the circuit board. Moreover, the flame retardance at the time of high temperature can also be exhibited.

In the present invention, a predetermined average particle diameter (D ₅₀₎ of gibbsite type aluminum hydroxide having (A), having a predetermined average particle diameter (D _50), boehmite particles, and free starting temperature of 400 ° C. or higher An inorganic material containing at least one inorganic component (B) selected from the group consisting of inorganic particles containing or not containing water of crystallization and aluminum oxide (C) having a small particle size in the above-mentioned ratio. By using a filler, the thermosetting resin composition for obtaining the laminated board which has the outstanding heat conductivity, the outstanding heat resistance, the outstanding drill workability, and a flame retardance is obtained.

A laminate obtained using such a thermosetting resin composition is preferably used for various substrates that require high heat dissipation, particularly for LED mounting substrates on which a plurality of LEDs that generate a large amount of heat are mounted. Can be. When a printed wiring board made of such a laminated board is surface-mounted with various electronic components, blisters are hardly generated on the metal foil even at a temperature of about 260 ° C., which is a lead-free reflow soldering temperature.

Further, the gibbsite type aluminum hydroxide particles (A) has a first gibbsite type aluminum hydroxide having an average particle size of 2 ~ 10μm _{(D 50),} the average particle size of 10 ~ 15 [mu] m to _{(D 50)} A blend with the second gibbsite type aluminum hydroxide is preferred. According to the said structure, the laminated board especially excellent in heat conductivity is obtained by being more closely filled with an inorganic filler.

Examples of the inorganic particles that are one of the inorganic components (B) include aluminum oxide, magnesium oxide, crystalline silica, aluminum hydroxide, boron nitride, aluminum nitride, silicon nitride, silicon carbide, talc, calcined kaolin, and clay. At least one kind of particles selected from the group consisting of

Further, a surface layer obtained by impregnating a woven fiber base material with a thermosetting resin composition in which the same components as the thermosetting resin composition described above are blended in the same composition ratio is the core material layer. A laminate obtained by laminating and integrating the both surfaces is preferable. According to the said structure, the laminated board which has the outstanding heat conductivity, the outstanding heat resistance, the outstanding drill workability, and a flame retardance is obtained.

A circuit board obtained from such a laminate is excellent in heat dissipation, flame retardancy, and particularly drillability. Therefore, it can be preferably used as a circuit board on which electronic components such as LEDs that require heat dissipation are mounted.

According to the present invention, a laminated board and a circuit board excellent in all of thermal conductivity, heat resistance, drill workability, and flame retardancy can be obtained.

Claims

A laminate in which a core layer obtained by impregnating a non-woven fiber base material with a thermosetting resin composition and a surface layer laminated on both surfaces of the core layer are laminated and integrated. There,
The thermosetting resin composition contains 80 to 150 parts by volume of an inorganic filler with respect to 100 parts by volume of the thermosetting resin,
The inorganic filler comprises (A) gibbsite type aluminum hydroxide particles having an average particle size (D 50 ) of 2 to 15 μm, (B) boehmite particles having an average particle size (D 50 ) of 2 to 15 μm, and 2 At least one inorganic component selected from the group consisting of inorganic particles having an average particle diameter (D 50 ) of ˜15 μm, containing crystal water having a freezing start temperature of 400 ° C. or higher, or containing no crystal water, and (C) containing aluminum oxide particles having an average particle diameter (D 50 ) of 1.5 μm or less,
A blending ratio (volume ratio) of at least one inorganic component (B) selected from the group consisting of the gibbsite-type aluminum hydroxide particles (A), the boehmite particles, and the inorganic particles and the aluminum oxide particles (C). 1. Laminate which is 1: 0.1-1: 0.1-1.
The gibbsite type aluminum hydroxide particles (A) has a first gibbsite type aluminum hydroxide having an average particle size of 2 ~ 10μm (D 50), second with an average particle diameter of 10 ~ 15μm (D 50) The laminate according to claim 1, which is a blend with a gibbsite type aluminum hydroxide.
Inorganic particles as one of the inorganic components (B) are made of aluminum oxide, magnesium oxide, crystalline silica, aluminum hydroxide, boron nitride, aluminum nitride, silicon nitride, silicon carbide, talc, calcined kaolin, and clay. The laminate according to claim 1 or 2, which is at least one kind of particles selected from the group.
The surface layer is formed by impregnating a woven fiber base material with a thermosetting resin composition,
The thermosetting resin composition contains 80 to 150 parts by volume of an inorganic filler with respect to 100 parts by volume of the thermosetting resin,
The inorganic filler comprises (A) gibbsite type aluminum hydroxide particles having an average particle size (D 50 ) of 2 to 15 μm, (B) boehmite particles having an average particle size (D 50 ) of 2 to 15 μm, and 2 At least one inorganic component selected from the group consisting of inorganic particles having an average particle diameter (D 50 ) of ˜15 μm, containing crystal water having a freezing start temperature of 400 ° C. or higher, or containing no crystal water, and (C) containing aluminum oxide particles having an average particle diameter (D 50 ) of 1.5 μm or less,
A blending ratio (volume ratio) of at least one inorganic component (B) selected from the group consisting of the gibbsite-type aluminum hydroxide particles (A), the boehmite particles, and the inorganic particles and the aluminum oxide particles (C). The laminate according to any one of claims 1 to 3, wherein the ratio is 1: 0.1 to 1: 0.1 to 1.
A metal foil-clad laminate in which a metal foil is stretched on at least one surface of the laminate according to any one of claims 1 to 4.
A circuit board obtained by forming a circuit on the metal foil-clad laminate according to claim 5.
An LED-mounted circuit board comprising the circuit board according to claim 6.