WO2012101991A1

WO2012101991A1 - Pre-preg, laminate board, printed wiring board, and semiconductor device

Info

Publication number: WO2012101991A1
Application number: PCT/JP2012/000316
Authority: WO
Inventors: 大東　範行
Original assignee: 住友ベークライト株式会社
Priority date: 2011-01-24
Filing date: 2012-01-19
Publication date: 2012-08-02
Also published as: JP5234195B2; CN103347938A; CN103347938B; TW201251534A; JP2012167256A; TWI539869B; KR101355777B1; MY155995A; KR20130102654A

Abstract

This pre-preg (40) is formed by impregnating a woven fiber constituted of strands with a resin composition. In this pre-preg, silica particles are present in the strands. This makes it possible to obtain a pre-preg having a superior ability for woven fiber to be impregnated with the resin composition. It is further possible to use this pre-preg and/or a metal-clad laminate board produced using this pre-preg to produce a printed wiring board and a semiconductor device.

Description

Prepreg, laminated board, printed wiring board, and semiconductor device

The present invention relates to a prepreg, a laminated board, a printed wiring board, and a semiconductor device.

2. Description of the Related Art In recent years, with the demand for higher functionality of electronic devices and the like, electronic components have been integrated at a high density and further at a high density mounting. For this reason, printed wiring boards for high-density mounting used for these are required to have finer circuit wiring and reduced through holes and via holes.
The through hole and the via hole are formed using a drill or a laser such as a carbon dioxide laser, but a laser is used particularly for drilling a small diameter. In laser drilling, the larger the unevenness of the wall surface of the insulating layer that forms the hole, the more easily the hole diameter and shape vary, and the processing accuracy decreases.
The insulating layer of the printed wiring board can be formed by heating and pressing one or a plurality of prepregs stacked together. In general, a prepreg is produced by impregnating a base material such as glass cloth with a varnish obtained by containing a resin composition containing a thermosetting resin as a main component in a solvent, and then heating and drying the varnish. Among the insulating layer wall surfaces in which holes are formed by laser processing, there is a difference in meltability by laser between the base material portion and the resin composition portion. For this reason, when the density of the base material is small and the eyes are rough, the hole diameter and shape tend to vary. On the other hand, by using a high-density base material with closed eyes, it is possible to improve the drilling workability of the insulating layer by laser (Patent Documents 1 and 2).

Further, in order to cope with the higher density of component mounting on the printed wiring board, it is required to reduce the warp due to thermal expansion of the printed wiring board and ensure connection reliability. A semiconductor device (semiconductor package) has a semiconductor element mounted on a printed wiring board, and the semiconductor element has a coefficient of thermal expansion of 3 to 6 ppm / ° C., and the coefficient of thermal expansion of a general printed wiring board for a semiconductor package. Smaller than. Therefore, when a thermal shock is applied to the semiconductor package, the semiconductor package may be warped due to a difference in thermal expansion coefficient between the semiconductor element and the printed wiring board for the semiconductor package. In this case, a connection failure may occur between the semiconductor element and the printed wiring board for a semiconductor package or between the semiconductor package and the printed wiring board to be mounted.
By using an insulating material having a low coefficient of thermal expansion for the insulating layer, warpage due to thermal expansion of the printed wiring board can be reduced. In order to reduce the linear expansion of a prepreg serving as an insulating material, a resin composition that is highly filled with an inorganic filler is used as a resin composition used in the manufacture of the prepreg (Patent Document 3).

JP 2001-38836 A Japanese Patent Laid-Open No. 2000-22302 JP 2009-138075 A

However, when a prepreg is produced using a high-density base material, the impregnation property of the resin composition to the base material is inferior. Especially in a resin composition containing a large amount of filler, the filler is between the fibers of the base material. Since it cannot enter, impregnation of the resin composition becomes difficult. Further, for example, when the content of the filler is reduced in order to improve the impregnation property, it may be difficult to maintain other characteristics of the prepreg.

The present invention has been made to solve the above-mentioned problems, and the object of the present invention is to improve the impregnation property of the thermosetting resin composition to the fiber woven fabric while maintaining various properties of the prepreg. Prepreg. Another object of the present invention is to provide a metal-clad laminate using the prepreg, a printed wiring board and a semiconductor device obtained using the metal-clad laminate.

According to the present invention, there is provided a prepreg obtained by impregnating a fiber woven fabric composed of strands with a resin composition, wherein silica particles are present in the strands.

ADVANTAGE OF THE INVENTION According to this invention, the prepreg excellent in the impregnation property of the thermosetting resin composition with respect to a fiber woven fabric can be provided, maintaining the various characteristics which a prepreg has.
Moreover, according to this invention, a printed wiring board and a semiconductor device can be manufactured using the said prepreg and / or the metal-clad laminated board manufactured using the said prepreg.

The above-described object and other objects, features, and advantages will be further clarified by a preferred embodiment described below and the following drawings attached thereto.

It is the schematic which shows an example of the manufacturing method of the metal-clad laminated board of this invention. It is the schematic which shows another example of the manufacturing method of the metal-clad laminated board of this invention. 2 is a photograph of a cross-sectional view of a prepreg obtained in Example 1. FIG. 6 is a photograph of a cross-sectional view of a prepreg obtained in Comparative Example 4. 4 is a photograph of the surface of the metal-clad laminate obtained in Example 1 that has been entirely etched. It is the photograph of the surface which etched the copper foil of the metal clad laminated board obtained by the comparative example 6 whole surface. It is a SEM photograph of the enlarged view of the void observed in FIG. It is a SEM photograph of the enlarged view of the cross section of the void observed in FIG. 2 is an SEM photograph of a cross-sectional view showing a part of a strand constituting the prepreg fiber woven fabric obtained in Example 1. FIG. 2 is an SEM photograph of a cross-sectional view showing a part of a strand constituting the prepreg fiber woven fabric obtained in Example 1. FIG. 2 is an SEM photograph of a cross-sectional view showing a part of a strand constituting the prepreg fiber woven fabric obtained in Example 1. FIG. 2 is an SEM photograph of a cross-sectional view showing a part of a strand constituting the prepreg fiber woven fabric obtained in Example 1. FIG.

Hereinafter, the prepreg, metal-clad laminate, printed wiring board, and semiconductor device of the present invention will be described in detail.

1. Prepreg The prepreg of the present invention is a prepreg formed by impregnating a fiber woven fabric composed of strands with a resin composition. Silica particles are present in the strands constituting the fiber woven fabric. The strand is a bundle of fibers constituting the fiber woven fabric. A fiber woven fabric is formed by weaving the strands so as to have a woven structure described later.
The present inventor has found that when the prepreg is formed so that the silica particles are present in the strand, the impregnation property of the resin composition into the fiber woven fabric can be improved while maintaining various properties of the prepreg. . Here, the various characteristics include, for example, insulation reliability of a printed wiring board to be described later, laser workability of a prepreg, or low thermal expansion of a prepreg.
When the impregnation property of the resin composition into the fiber woven fabric is good, generation of voids in the resulting prepreg can be suppressed. Thereby, in the printed wiring board using the prepreg as an insulating layer, the insulation reliability can be improved.
Further, even when a high-density fiber woven fabric is used, high impregnation properties can be obtained. For this reason, the prepreg excellent in laser workability can be formed using a high-density fiber woven fabric.
Furthermore, by improving the impregnation property of the resin composition into the fiber woven fabric, it becomes possible to highly fill the filler into the fiber woven fabric. For this reason, low thermal expansion of the prepreg can be achieved. Thereby, it can suppress that curvature generate | occur | produces in the printed wiring board which used the said prepreg for the insulating layer. Therefore, connection reliability in the semiconductor device can be improved.

The resin composition constituting the prepreg is a thermosetting resin composition (hereinafter sometimes simply referred to as “resin composition”) including at least a thermosetting resin and a filler.
The resin composition constituting the prepreg preferably contains, for example, silica particles having an average particle size of 5 to 100 nm in a proportion of 1 to 20% by mass of the filler. The inventor of the present invention has an average particle diameter of 5 to 1% by mass in the filler even in the case of a prepreg obtained by impregnating a high-density fiber woven fabric with a resin composition containing a large amount of filler. It has been found that the impregnation property of the resin composition is improved by incorporating silica particles of ˜100 nm. This is because the silica particles having an average particle diameter of 5 to 100 nm enter between the fibers of the fiber woven fabric, that is, spread between the fibers by spreading into the strands. This is thought to be because it becomes possible to get into. Thus, by using nano-sized silica particles having an average particle size of 5 to 100 nm as a filler, a prepreg having silica particles in the strand can be obtained.
Further, due to the difference between the surface potential of silica particles having an average particle diameter of 5 to 100 nm and the surface potential of other fillers, the silica particles having an average particle diameter of 5 to 100 nm and the filler are attracted by interaction. Therefore, silica particles having an average particle diameter of 5 to 100 nm are present around the filler, and the silica particles having an average particle diameter of 5 to 100 nm have a spacer action. In this way, silica particles having an average particle size of 5 to 100 nm are present around the filler and act as a spacer, thereby reducing the attractive force of the filler due to van der Waals force and preventing aggregation. To do. This makes the filler more highly dispersed and prevents fluidity from being lowered.
The silica particles having an average particle diameter of 5 to 100 nm are preferably used as a slurry previously dispersed in an organic solvent. Thereby, the dispersibility of a filler can be improved and the fall of the fluidity | liquidity which arises when using another filler can be suppressed. The reason is considered as follows. First, nano-sized particles such as nano-sized silica tend to aggregate and often form secondary aggregates when blended into the resin composition. Such secondary agglomeration can be prevented, thereby preventing the fluidity from being lowered. In addition, the filler used in the present invention is preferably subjected to surface treatment in advance in order to prevent aggregation and improve dispersibility.
In the present invention, the high-density fiber woven fabric refers to a fiber that has been treated not only to increase the number of yarns to be driven, but also to uniformly and highly open each fiber and reduce the thickness by flattening. Means woven fabric. The high-density fiber woven fabric has, for example, a bulk density of 1.05 g / cm ³ or more. Thereby, since the resin composition can be further impregnated between the fibers one by one, the filler can be further highly filled. Furthermore, since the amount of resin on the fiber woven fabric can be secured sufficiently, the moldability is maintained when copper foil is laminated on a prepreg to make a copper-clad laminate or when the surface of a copper-clad laminate is smoothed. can do.

Thus, since the prepreg of this invention has the favorable impregnation property of the resin composition with respect to a fiber woven fabric, there is little generation | occurrence | production of a void. Further, since a large amount of filler is contained in the resin composition, it has low thermal expansion and the printed wiring board obtained using the prepreg of the present invention has little warpage. In addition, in this invention, the thermal expansibility of a prepreg means the thermal expansibility in the state which hardened the prepreg.
In addition, the prepreg of the present invention has excellent heat resistance and high rigidity due to high filling of the filler. Furthermore, the bulk density of the fiber woven fabric constituting the prepreg of the present invention is preferably 1.05 to 1.30 g / cm ³ . By using a high-density fiber woven fabric with a bulk density of 1.05 to 1.30 g / cm ³ , when used as an insulating layer of a printed wiring board, the accuracy of the hole diameter and shape is improved by laser processing. And the hole which suppressed the protrusion of the fiber can be formed.
In general, a prepreg obtained by using a resin composition containing a large amount of a filler deteriorates the impregnation property of the resin composition with respect to the base material, so that the base material has a uniform thickness. When the printed wiring board is produced using the prepreg as an insulating layer, the insulating layer is inferior in surface smoothness and adhesion to the conductor layer, and the fine wiring process is difficult. There is a point. This tends to get worse when the prepreg is made thinner. On the other hand, since the prepreg of the present invention has a good impregnation property of the resin composition with respect to the fiber woven fabric, the fiber woven fabric can hold the resin composition with a uniform thickness, The adhesiveness is good, and it is also possible to cope with thinning. Moreover, the prepreg of the present invention has high heat resistance and high rigidity by using a resin composition containing a large amount of a filler.

First, the fiber woven fabric used in the present invention will be described.
The fiber woven fabric used in the present invention is not particularly limited. For example, a fiber woven fabric made of synthetic fiber such as glass fiber, aramid, polyester, aromatic polyester, fluororesin, metal fiber, carbon fiber, mineral fiber, etc. Is mentioned. Among them, a glass fiber woven fabric made of glass fibers is preferable because of its low thermal expansion, high rigidity, and excellent dimensional stability.

The glass fiber is not particularly limited, but contains at least SiO ₂ in a proportion of 50% by mass to 100% by mass, Al ₂ O ₃ in a proportion of 0% by mass to 30% by mass, and CaO in a proportion of 0% by mass to 30% by mass. In particular, it is preferable to use at least one glass selected from the group consisting of T glass (sometimes referred to as “S glass”), D glass, E glass, NE glass, and quartz glass. Among these, T glass (S glass), quartz glass, and D glass are more preferable, and T glass (S glass) and quartz glass are more preferable from the viewpoint of excellent low thermal expansion and high strength.
In the present invention, T glass (S glass) means SiO ₂ 62 mass% to 65 mass%, Al ₂ O ₃ 20 mass% to 25 mass%, and CaO 0 mass% to 0.01 mass%. MgO is contained in an amount of 10% by mass to 15% by mass, B ₂ O ₃ is contained in an amount of 0% by mass to 0.01% by mass, and Na ₂ O and K ₂ O are combined in a proportion of 0% by mass to 1% by mass. D glass is SiO ₂ 72 mass% to 76 mass%, Al ₂ O ₃ 0 mass% to 5 mass%, CaO 0 mass% to 1 mass%, MgO 0 mass% to 1 mass. _mass%, the B 2 _{O 3} 20 wt% to 25 wt%, a glass having a composition in a proportion of 3% to 5% by weight combined Na ₂ O and _{K 2} O, and the E-glass, SiO ₂ 52 wt% to 56 wt%, the _Al 2 _{O 3} 12 wt% to 16 wt%, the CaO 1 % To 25 wt%, the MgO 0% to 6 _wt%, B a 2 _{O 3} 5 wt% to 10 wt%, in a proportion of from 0 to 0.8 weight% combined Na ₂ O and _{K 2} O NE glass is composed of 52 mass% to 56 mass% of SiO ₂ , 10 mass% to 15 mass% of Al ₂ O ₃ , 0 mass% to 10 mass% of CaO, and 0 mass% of MgO. % By mass to 5% by mass, 15% by mass to 20% by mass of B ₂ O ₃ , 0% by mass to 1% by mass of Na ₂ O and K ₂ O, 0.05% by mass to 5% by mass of TiO ₂ The quartz glass is a glass having a composition containing SiO ₂ at a ratio of 99.0% by mass to 100% by mass.

The glass fiber is not particularly limited, but the Young's modulus when formed into a plate is 50 to 100 GPa, the tensile strength when formed into a plate is 25 GPa or more, and the tensile strength in the longitudinal direction when formed into a fiber woven fabric is 30 N / It is preferably 25 mm or more, more preferably, the Young's modulus when plate-shaped is 80 to 100 GPa, the tensile strength when plate-shaped is 35 GPa or more, and the tensile strength in the longitudinal direction when fiber woven fabric is formed. It is 45 N / 25 mm or more. Thereby, the prepreg excellent in dimensional stability is obtained. The Young's modulus is a value measured by a commonly used known three-point bending tester in accordance with JIS R1602, and the tensile strength is in accordance with JIS R3420 and commonly used. It is a value measured by a constant speed extension type tensile tester, and the tensile strength in the longitudinal direction conforms to JIS R3420, and is measured by a constant speed extension type tensile tester similar to the above using glass fiber as a woven fabric. Value.
In the measurement of the Young's modulus and the measurement of the tensile strength, “plate shape” means a state in which a glass composition having the same composition as the glass fiber is formed into a glass plate having a thickness of 0.5 to 1.0 mm. . In the measurement of the tensile strength in the longitudinal direction, the “longitudinal direction” means the warp (warp) direction.

The glass fiber is not particularly limited, but the thermal expansion coefficient in the warp direction measured according to JIS R3102 is preferably 10 ppm / ° C. or less, and particularly preferably 3 ppm / ° C. or less. Thereby, the curvature by the thermal expansion of a printed wiring board can be made small.

The thickness of the fiber woven fabric is not particularly limited, but is preferably 10 to 200 μm, more preferably 10 to 140 μm, and still more preferably 20 to 90 μm. Thereby, the impregnation property of the resin composition with respect to the fiber woven fabric becomes good, and it becomes possible to cope with the thinning.

The bulk density of the fiber woven fabric is preferably 1.05 to 1.30 g / cm ³ , and more preferably 1.10 to 1.25 g / cm ³ . When the bulk density is less than the lower limit, the laser processability of the insulating layer is inferior, and when the upper limit is exceeded, the impregnation property of the resin composition with respect to the fiber woven fabric is deteriorated. The bulk density of the fiber woven fabric is adjusted by adjusting the number of warps and wefts to be driven and the thickness of the fiber that has been subjected to the opening and flattening treatment.

The fiber woven fabric is not particularly limited, but the air permeability is preferably 1 to 80 cc / cm ² / sec, and particularly preferably 3 to 50 cc / cm ² / sec. When the air permeability is less than the lower limit, the impregnation property of the resin composition with respect to the fiber woven fabric is deteriorated, and when the air permeability exceeds the upper limit, the laser processability of the insulating layer is inferior.

The fiber fabric is not particularly limited, it is preferable that a basis weight of 10 ~ 160g / ^{m 2,} and particularly preferably 15 ~ 130g / ^{m 2.} When the basis weight is less than the lower limit value, the low thermal expansion property of the prepreg is inferior, and when the upper limit value is exceeded, the impregnation property of the resin composition to the fiber woven fabric is deteriorated, or the laser processability of the insulating layer is inferior. .

Further, the fiber used for the fiber woven fabric is not particularly limited, but the aspect ratio is preferably 1: 2 to 1:50, particularly preferably 1: 5 to 1:30. When the flatness of the fiber used in the fiber woven fabric is within the above range, the impregnation and wettability of the resin composition to the fiber woven fabric is further improved, so that the insulation reliability between the through holes is improved, and the insulation The laser processability of the layer can be improved. In the present invention, the flatness is a value represented by the thickness of the yarn: the width of the yarn.

The weaving structure of the fiber woven fabric is not particularly limited, and examples thereof include plain weaving, nanako weaving, satin weaving, twill weaving, and the like. Among them, laser workability, strength, interlayer insulation reliability of via holes, etc. From the viewpoint of excellent properties, a plain weave structure is preferable.

Next, the thermosetting resin composition used in the present invention will be described.
The thermosetting resin composition used in the present invention includes at least a thermosetting resin and a filler. The filler is contained in a proportion of 50 to 85% by mass of the solid content of the thermosetting resin composition. The thermosetting resin composition contains silica particles having an average particle size of 5 to 100 nm in a proportion of 1 to 20% by mass of the filler. Furthermore, the thermosetting resin composition may further contain a curing agent, a coupling agent, and the like, if necessary.

(Filler)
The filler contains silica particles having an average particle diameter of 5 to 100 nm in a proportion of 1 to 20% by mass of the whole filler.
The silica particles are not particularly limited. For example, combustion methods such as VMC (Vaporized Metal Combustion) method, PVS (Physical Vapor Synthesis) method, methods such as melting method, fusing method, precipitation method, gel method, etc. Can be used. Among these, the VMC method is particularly preferable. The VMC method is a method in which silica powder is formed by putting silicon powder into a chemical flame formed in an oxygen-containing gas, burning it, and then cooling it. In the VMC method, the particle diameter of the silica fine particles to be obtained can be adjusted by adjusting the particle diameter of the silicon powder to be input, the input amount, the flame temperature and the like. In addition, as the silica particles, commercially available products such as NSS-5N (manufactured by Tokuyama Co., Ltd.), Sicastar 43-00-501 (manufactured by Micromod) can also be used.

The silica particles having an average particle size of 5 to 100 nm are particularly preferably an average particle size of 10 to 75 nm from the viewpoint of impregnation. If the average particle diameter of the silica particles is less than 5 nm, it is considered that the space between the fibers of the fiber woven fabric cannot be expanded, and if it is greater than 100 nm, it may not be possible to enter between the fibers.

The average particle diameter of the silica particles can be measured by, for example, a laser diffraction scattering method and a dynamic light scattering method. In the case of silica particles having an average particle size of 5 to 100 nm, the particles are dispersed by ultrasonic waves in water, and the particle size distribution of the particles on a volume basis is measured by a dynamic light scattering particle size distribution analyzer (manufactured by HORIBA, LB-550). Measure and use the median diameter (D50) as the average particle diameter.

The silica particles are not particularly limited, but are preferably hydrophobic. Thereby, aggregation of a silica particle can be suppressed and a silica particle can be favorably disperse | distributed in the resin composition of this invention. In addition, since the affinity between the thermosetting resin and the silica particles is improved and the surface adhesion between the thermosetting resin and the silica particles is improved, an insulating layer having excellent mechanical strength can be obtained.

Examples of a method for making silica particles hydrophobic include a method in which silica particles are surface-treated with functional group-containing silanes and / or alkylsilazanes in advance. Known functional group-containing silanes can be used, and examples include epoxy silane, amino silane, vinyl silane, acrylic silane, mercapto silane, isocyanate silane, sulfide silane, and ureido silane. Examples of the alkylsilazanes include hexamethyldisilazane (HMDS), 1,3-divinyl-1,1,3,3-tetramethyldisilazane, octamethyltrisilazane, hexamethylcyclotrisilazane, and the like. . In addition, by performing the surface treatment on the silica particles, the effect of preventing the filler from agglomerating and improving the dispersibility is also exhibited.

The amount of functional group-containing silanes and / or alkylsilazanes to be surface-treated in advance on the silica particles is not particularly limited, but is 0.01 parts by weight or more and 5 parts by weight or less with respect to 100 parts by weight of the silica particles. It is preferable. More preferably, it is 0.1 to 3 parts by weight. If the content of the functional group-containing silanes and / or alkylsilazanes exceeds the upper limit, the insulating layer may crack when the printed wiring board is produced. If the content is less than the lower limit, the resin component and silica The bond strength with the particles may be reduced.

The method for surface-treating the silica particles with functional group-containing silanes and / or alkylsilazanes in advance is not particularly limited, but a wet method or a dry method is preferable. The wet method is particularly preferable. When the wet method is compared with the dry method, the surface of the silica particles can be uniformly processed.
The surface treatment is preferably performed on 50% or more of the specific surface area.

The silica particles having an average particle diameter of 5 to 100 nm are contained in a proportion of 1 to 20% by mass of the whole filler. When the content is less than the lower limit, the effect of improving the impregnation property is insufficient, and when the content exceeds the upper limit, the impregnation property may be deteriorated or the prepreg may be inferior. The content of silica particles having an average particle size of 5 to 100 nm is more preferably 3 to 15% by mass of the whole filler.

The filler used in the present invention is not particularly limited in addition to the silica particles having an average particle diameter of 5 to 100 nm. For example, silicates such as talc, fired clay, unfired clay, mica, glass, and titanium oxide , Alumina, oxides such as silica particles with an average particle size greater than 100 nm, carbonates such as calcium carbonate, magnesium carbonate, hydrotalcite, aluminum hydroxide, boehmite (AlO (OH), usually called “pseudo” boehmite) boehmite _{_{_{(i.e., Al 2 O 3 · xH 2}}} O, where, x = 1 to 2)), magnesium hydroxide, metal hydroxides such as calcium hydroxide, barium sulfate, calcium sulfate, sulfates such as calcium sulfite Or sulfite, zinc borate, barium metaborate, aluminum borate, calcium borate, sodium borate Borates like can contain aluminum nitride, boron nitride, silicon nitride, nitrides such as carbon nitride, strontium titanate, an inorganic filler such as titanates such as barium titanate. One of these inorganic fillers can be used alone, or two or more of them can be used in combination. Among these, magnesium hydroxide, aluminum hydroxide, boehmite, spherical silica particles having an average particle diameter larger than 100 nm, talc, calcined talc, and alumina are preferable, and boehmite and average particle diameter are particularly low in terms of low thermal expansion and impregnation. Spherical silica particles larger than 100 nm and spherical alumina are preferred.

The inorganic filler other than silica particles having an average particle diameter of 5 to 100 nm (hereinafter sometimes referred to as “other inorganic fillers”) is not particularly limited, but the inorganic filler has a monodisperse average particle diameter. A material can also be used, and an inorganic filler having a polydispersed average particle diameter can also be used. Furthermore, one type or two or more types of inorganic fillers having an average particle size of monodisperse and / or polydisperse can be used in combination. In the present invention, the average particle size is monodispersed means that the standard deviation of the particle size is 10% or less, and the polydispersed means that the standard deviation of the particle size is 10% or more. means.
The average particle diameter of the other inorganic filler is not particularly limited, but is preferably 0.1 μm to 5.0 μm, and particularly preferably 0.1 μm to 3.0 μm. If the particle size of the other inorganic filler is less than the lower limit, the viscosity of the resin composition becomes high, which may affect the workability during prepreg production. When the upper limit is exceeded, phenomena such as sedimentation of the inorganic filler may occur in the resin composition. The average particle diameter can be measured using a laser diffraction / scattering particle size distribution measuring apparatus (a general instrument such as Shimadzu SALD-7000).

Furthermore, in the case of performing processing of small-diameter holes, narrow pitch processing of holes, and fine wire processing, it is preferable that the other inorganic fillers are coarsely cut. Among them, it is preferable to have a coarse grain cut of 45 μm or more, more preferably a coarse grain cut of 20 μm or more, and particularly preferably a coarse grain cut of 10 μm or more. Incidentally, “coarse grain cut” means that coarse grains having a size equal to or larger than the grain size are excluded.

Moreover, it is preferable that the filler used for this invention contains organic fillers, such as a rubber particle other than the said inorganic filler. Preferable examples of the rubber particles that can be used in the present invention include core-shell type rubber particles, cross-linked acrylonitrile butadiene rubber particles, cross-linked styrene butadiene rubber particles, acrylic rubber particles, and silicone particles.
The core-shell type rubber particles are rubber particles having a core layer and a shell layer. For example, a two-layer structure in which an outer shell layer is formed of a glassy polymer and an inner core layer is formed of a rubbery polymer, or Examples include a three-layer structure in which the outer shell layer is made of a glassy polymer, the intermediate layer is made of a rubbery polymer, and the core layer is made of a glassy polymer. The glassy polymer layer is made of, for example, a polymer of methyl methacrylate, and the rubbery polymer layer is made of, for example, a butyl acrylate polymer (butyl rubber). Specific examples of the core-shell type rubber particles include Staphyloid AC3832, AC3816N (trade name, manufactured by Ganz Kasei Co., Ltd.), and Metabrene KW-4426 (trade name, manufactured by Mitsubishi Rayon Co., Ltd.). Specific examples of the crosslinked acrylonitrile butadiene rubber (NBR) particles include XER-91 (average particle size 0.5 μm, manufactured by JSR Corporation).
Specific examples of the crosslinked styrene butadiene rubber (SBR) particles include XSK-500 (average particle size: 0.5 μm, manufactured by JSR Corporation). Specific examples of the acrylic rubber particles include methabrene W300A (average particle size 0.1 μm), W450A (average particle size 0.2 μm) (manufactured by Mitsubishi Rayon Co., Ltd.), and the like.
The silicone particles are not particularly limited as long as they are rubber elastic fine particles formed of organopolysiloxane. For example, fine particles made of silicone rubber (organopolysiloxane crosslinked elastomer) itself, and a core portion made of two-dimensionally crosslinked silicone. And core-shell structured particles coated with silicone mainly composed of a three-dimensional crosslinking type. Examples of the silicone particles include KMP-605, KMP-600, KMP-597, KMP-594 (manufactured by Shin-Etsu Chemical Co., Ltd.), Trefil E-500, Trefil E-600 (manufactured by Toray Dow Corning Co., Ltd.), etc. Commercial products can be used.

Of the fillers used in the present invention, fillers other than silica particles having an average particle diameter of 5 to 100 nm are preferably preliminarily surface-treated in order to prevent aggregation and improve dispersibility. As the surface treatment agent, a known silane coupling agent can be used, and examples thereof include epoxy silane, amino silane, vinyl silane, acrylic silane, and mercapto silane. The surface treatment is preferably 50% or more of the specific surface area.

The content of the filler in the resin composition used in the present invention is preferably 50 to 85% by mass, particularly 65 to 75% by mass, based on the solid content of the entire resin composition. If the filler content exceeds the upper limit, the fluidity of the resin composition is extremely poor, and the workability during prepreg production is poor. If it is less than the lower limit, the coefficient of thermal expansion is high and the strength of the insulating layer may not be sufficient.

(Thermosetting resin)
The thermosetting resin is not particularly limited, and epoxy resin, cyanate resin, bismaleimide resin, phenol resin, benzoxazine resin, vinyl benzyl ether resin, benzocyclobutene resin, etc. are used. Other thermosetting resins are used in appropriate combination.

The epoxy resin is not particularly limited but is preferably substantially free of halogen atoms. Here, “substantially free of halogen atoms” means that the halogen derived from the halogen-based component used in the epoxy resin synthesis process remains in the epoxy resin even after the halogen removal step. Means to allow. Usually, it is preferable that the epoxy resin does not contain a halogen atom exceeding 30 ppm.

Examples of the epoxy resin substantially free of halogen atoms include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, bisphenol Z type epoxy resin (4,4'- Cyclohexyldiene bisphenol type epoxy resin), bisphenol P type epoxy resin (4,4 '-(1,4) -phenylenediisopropylidene) bisphenol type epoxy resin), bisphenol M type epoxy resin (4,4'-(1 , 3-phenylenediisopropylidene) bisphenol type epoxy resin), phenol novolac type epoxy resin, cresol novolac type epoxy resin and other novolak type epoxy resin, biphenyl type epoxy resin, xylylene type Poxy resin, phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, biphenyl dimethylene type epoxy resin, trisphenol methane novolak type epoxy resin, glycidyl ethers of 1,1,2,2- (tetraphenol) ethane, trifunctional , Or tetrafunctional glycidylamines, arylalkylene type epoxy resins such as tetramethylbiphenyl type epoxy resin, naphthalene skeleton modified epoxy resin, methoxynaphthalene modified cresol novolak type epoxy resin, methoxynaphthalenediethylene type epoxy resin, naphthylene ether type Naphthalene type epoxy resin such as epoxy resin, anthracene type epoxy resin, phenoxy type epoxy resin, dicyclopentadiene type epoxy resin, norbornene type epoxy resin, Adamantane type epoxy resin, fluorene type epoxy resins, flame-retarded epoxy resin or the like halogenated epoxy resins.
One of these epoxy resins can be used alone, or two or more types of epoxy resins having different weight average molecular weights can be used in combination. One or more types of epoxy resins and epoxy A resin prepolymer can also be used in combination.
Among these epoxy resins, at least one selected from the group consisting of biphenyl dimethylene type epoxy resins, novolac type epoxy resins, naphthalene-modified cresol novolac epoxy resins, and anthracene type epoxy resins is preferable. By using these epoxy resins, the moisture-absorbing solder heat resistance and flame retardancy of the resulting laminate and printed wiring board can be improved.
Moreover, among these epoxy resins, by using a naphthylene ether type epoxy resin, it is possible to improve the heat resistance, the low thermal expansion property, and the low thermal contraction property of the obtained laminated board and printed wiring board.
The naphthylene ether type epoxy resin can be represented by, for example, the following general formula (1).

(Wherein R1 represents a hydrogen atom or a methyl group, R2 each independently represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an aralkyl group, a naphthalene group, or a glycidyl ether group-containing naphthalene group; And m are each an integer of 0 to 2, and either o or m is 1 or more.)

The content of the epoxy resin is not particularly limited, but is preferably 5 to 60% by weight based on the solid content of the entire resin composition. If the content is less than the lower limit, the curability of the resin composition may be reduced, or the moisture resistance of a prepreg or printed wiring board obtained using the resin composition may be reduced. Moreover, when the said upper limit is exceeded, the linear thermal expansion coefficient of a prepreg or a printed wiring board may become large, or heat resistance may fall. The content of the epoxy resin is particularly preferably 10 to 50% by weight based on the solid content of the entire resin composition.

The weight average molecular weight of the epoxy resin is not particularly limited, but is preferably 1.0 × 10 ² to 2.0 × 10 ⁴ . When the weight average molecular weight is less than the lower limit, tackiness may occur on the surface of the prepreg, and when the upper limit is exceeded, the solder heat resistance of the prepreg may decrease. By setting the weight average molecular weight within the above range, it is possible to achieve an excellent balance of these characteristics.
In the present invention, the weight average molecular weight of the epoxy resin can be measured, for example, by gel permeation chromatography (GPC) and specified as a weight molecular weight in terms of polystyrene.

The resin composition is not particularly limited. By including a cyanate resin, the flame retardancy is improved, the thermal expansion coefficient is reduced, and the electrical properties (low dielectric constant, low dielectric loss tangent) of the prepreg are improved. Can be made.
The cyanate resin is not particularly limited, and can be obtained, for example, by reacting a halogenated cyanide compound with phenols or naphthols, and prepolymerizing by a method such as heating as necessary. Moreover, the commercial item prepared in this way can also be used.

Although it does not specifically limit as a kind of said cyanate resin, For example, bisphenol-type cyanate resin, such as novolak-type cyanate resin, bisphenol A-type cyanate resin, bisphenol E-type cyanate resin, tetramethylbisphenol F-type cyanate resin, etc. can be mentioned. .

The cyanate resin preferably has two or more cyanate groups (—O—CN) in the molecule. For example, 2,2′-bis (4-cyanatophenyl) isopropylidene, 1,1′-bis (4-cyanatophenyl) ethane, bis (4-cyanato-3,5-dimethylphenyl) methane, 3-bis (4-cyanatophenyl-1- (1-methylethylidene)) benzene, dicyclopentadiene type cyanate ester, phenol novolac type cyanate ester, bis (4-cyanatophenyl) thioether, bis (4-cyanato) Phenyl) ether, 1,1,1-tris (4-cyanatophenyl) ethane, tris (4-cyanatophenyl) phosphite, bis (4-cyanatophenyl) sulfone, 2,2-bis (4-si Anatophenyl) propane, 1,3-, 1,4-, 1,6-, 1,8-, 2,6- or 2,7-dicyanatonaphthalene, 1, , 6-tricyanatonaphthalene, 4,4-dicyanatobiphenyl, phenol novolak-type, cresol novolak-type polyhydric phenols, cyanate resins obtained by the reaction of cyanogen halides, naphthol aralkyl-type polyvalent naphthols And cyanate resin obtained by reaction with cyanogen halide.
Among these, phenol novolac-type cyanate resin is excellent in flame retardancy and low thermal expansion, and 2,2′-bis (4-cyanatophenyl) isopropylidene and dicyclopentadiene-type cyanate ester control the crosslinking density. Excellent in moisture resistance and reliability. In particular, a phenol novolac type cyanate resin is preferred from the viewpoint of low thermal expansion. Furthermore, other cyanate resins may be used alone or in combination of two or more, and are not particularly limited.

The cyanate resin may be used alone. Two or more cyanate resins having different weight average molecular weights may be used in combination, or the cyanate resin and its prepolymer may be used in combination.
The prepolymer is usually obtained by, for example, trimerizing the cyanate resin by a heat reaction or the like, and is preferably used for adjusting the moldability and fluidity of the resin composition.
The prepolymer is not particularly limited. For example, when a prepolymer having a trimerization ratio of 20 to 50% by weight is used, good moldability and fluidity can be exhibited.

The content of the cyanate resin is not particularly limited, but is preferably 5 to 60% by weight, more preferably 10 to 50% by weight, based on the solid content of the entire resin composition. When the content of the cyanate resin is within the above range, the heat resistance and flame retardancy of the prepreg can be more effectively improved. When the content of the cyanate resin is less than the lower limit, the thermal expansion of the prepreg may be increased and the heat resistance may be decreased. When the upper limit is exceeded, the strength of the prepreg may be decreased.

The weight average molecular weight of the cyanate resin is not particularly limited, but is preferably 5.0 × 10 ² to 4.5 × 10 ³ , particularly preferably 6.0 × 10 ² to 3.0 × 10 ³ . If the weight average molecular weight is less than the lower limit, tackiness may occur on the surface of the prepreg or the mechanical strength may be reduced. Moreover, when a weight average molecular weight exceeds the said upper limit, the hardening reaction of a resin composition will become quick and adhesiveness with a conductor layer may deteriorate.
In the present invention, the weight average molecular weight of the cyanate resin can be measured, for example, by gel permeation chromatography (GPC) and specified as a weight molecular weight in terms of polystyrene.

Although the said resin composition is not specifically limited, Heat resistance can be improved by including a bismaleimide resin.
The bismaleimide resin is not particularly limited, but N, N ′-(4,4′-diphenylmethane) bismaleimide, bis (3-ethyl-5-methyl-4-maleimidophenyl) methane, 2,2-bis And bismaleimide resins such as [4- (4-maleimidophenoxy) phenyl] propane. The bismaleimide resin may be used in combination with one or more other bismaleimide resins, and is not particularly limited. The bismaleimide resin may be used alone. Moreover, the bismaleimide resin from which a weight average molecular weight differs can be used together, or the said bismaleimide resin and its prepolymer can also be used together.

The content of the bismaleimide resin is not particularly limited, but is preferably 1 to 35% by weight, particularly preferably 5 to 20% by weight, based on the solid content of the entire resin composition.

(Curing agent, curing accelerator)
The resin composition used in the present invention may be used in combination with a curing agent. The curing agent is not particularly limited. For example, when an epoxy resin is used as the thermosetting resin, a phenolic curing agent generally used as a curing agent for the epoxy resin, an aliphatic amine, an aromatic amine, dicyandiamide, Dicarboxylic acid dihydrazide compounds, acid anhydrides, and the like can be used.

Moreover, a curing accelerator can be added to the resin composition used in the present invention as necessary. The curing accelerator is not particularly limited, and examples thereof include organic metal salts, tertiary amines, imidazoles, organic acids, onium salt compounds, and the like. As a hardening accelerator, 1 type can also be used independently including the derivative in these, and 2 or more types can also be used together including these derivatives.

(Coupling agent)
The resin composition may further contain a coupling agent. The coupling agent is blended to improve the wettability of the interface between the thermosetting resin and the filler. Thereby, the resin and the filler can be uniformly fixed to the fiber woven fabric, and the heat resistance of the prepreg, particularly the solder heat resistance after moisture absorption can be improved.
Although the said coupling agent is not specifically limited, For example, an epoxy silane coupling agent, a cationic silane coupling agent, an aminosilane coupling agent, a titanate coupling agent, a silicone oil type coupling agent etc. are mentioned. Thereby, wettability with the interface of a filler can be made high, and, thereby, the heat resistance of a prepreg can be improved more.

The amount of the coupling agent to be added is not particularly limited, but is preferably 0.05 to 3 parts by weight, particularly preferably 0.1 to 2 parts by weight with respect to 100 parts by weight of the filler. If the content is less than the lower limit, the filler cannot be sufficiently covered, and the effect of improving heat resistance may be reduced. Moreover, when content exceeds the said upper limit, reaction will be affected and bending strength etc. may fall.

(Other)
In addition, the resin composition may include an antifoaming agent, a leveling agent, an ultraviolet absorber, a foaming agent, an antioxidant, a flame retardant, a phosphorus-based, phosphazene or other flame retardant aid, an ion scavenger, etc. Additives other than the above components may be added.

The prepreg of the present invention is obtained by holding a varnish containing the above-mentioned thermosetting resin composition in a solvent on a fiber woven fabric and then removing the solvent. The method for preparing the varnish is not particularly limited. For example, a slurry in which a thermosetting resin and a filler are dispersed in a solvent is prepared, the other resin composition components are added to the slurry, and the solvent is further added. The method of dissolving and mixing is preferable. As a result, the dispersibility of the filler can be improved, and the silica particles having an average particle size of 5 to 100 nm contained in the filler can be easily introduced into the fiber woven fabric, and the resin composition can be impregnated into the fiber woven fabric. Can be improved.
In the present invention, the term “containing a thermosetting resin composition in a solvent” means that a soluble resin or the like contained in the thermosetting resin composition is dissolved in a solvent, and an insoluble filler or the like is dispersed in the solvent. Means that.

The solvent is not particularly limited, but a solvent that exhibits good solubility in the resin composition is preferable. For example, acetone, methyl ethyl ketone (MEK), cyclohexanone (ANON), methyl isobutyl ketone (MIBK), cyclopenta Non, dimethylformamide, dimethylacetamide, N-methylpyrrolidone and the like. In addition, you may use a poor solvent in the range which does not exert a bad influence.

The solid content of the resin composition contained in the varnish (a component obtained by removing the solvent from the varnish) is not particularly limited, but is preferably 30 to 80% by weight, particularly preferably 40 to 70% by weight. Thereby, the impregnation property to the fiber woven fabric of the resin composition is improved. Moreover, the surface smoothness at the time of coating, thickness variation, etc. can be suppressed.

The method of impregnating the fiber woven fabric with the varnish includes, for example, a method of immersing the fiber woven fabric in the varnish, a method of applying with various coaters, a method of spraying with a spray, and applying and drying the varnish on a substrate to produce a resin sheet And the method of arrange | positioning the said resin sheet so that a resin layer may contact | connect a fiber woven fabric, and crimping | bonding it is mentioned. Among these, the method of immersing the fiber woven fabric in the varnish is preferable. Thereby, the impregnation property of the thermosetting resin composition with respect to the fiber woven fabric can be improved. In addition, when a fiber woven fabric is immersed in a varnish, a normal impregnation coating equipment can be used. Further, a semi-cured prepreg can be obtained by drying the solvent of the varnish at, for example, 90 to 180 ° C. for 1 to 10 minutes.

The prepreg includes a fiber woven fabric layer made of a fiber woven fabric and a resin layer made of a resin composition formed on both surfaces of the fiber woven fabric layer. The thickness of the fiber woven fabric layer is not particularly limited, but is preferably 10 to 200 μm, more preferably 10 to 140 μm, and still more preferably 20 to 90 μm. The thickness of the resin layer (thickness on one side only) is not particularly limited, but is preferably 0.5 to 20 μm, particularly preferably 2 to 10 μm. When the thickness of the fiber woven fabric layer and the thickness of the resin layer are within the above ranges, the adhesion to the conductor layer and the surface smoothness are further improved.

The total thickness of the prepreg is not particularly limited, but is preferably 30 to 220 μm, and particularly preferably 40 to 165 μm. Thereby, the handleability of a prepreg is favorable and it can respond also to thickness reduction.

In the prepreg, in the strands constituting the fiber woven fabric, there are no voids having a length of 50 μm or more in the extending direction of the fibers constituting the strands. Thereby, the insulation reliability of the printed wiring board which used the prepreg for the insulating layer can be improved. Furthermore, it is preferable that the strands constituting the fiber woven fabric do not have voids having a length of 20 μm or more, particularly 10 μm or more in the direction in which the fibers constituting the strands are stretched.
In the prepreg, the number density of voids having a diameter of 50 μm or more in the strand constituting the fiber woven fabric is 50 cm ⁻¹ or less. Even in this case, the insulation reliability of the printed wiring board using the prepreg as the insulating layer can be improved. Further, the number density of voids having a diameter of 50 μm or more in the strands constituting the fiber woven fabric is preferably 20 cm ⁻¹ or less, particularly preferably 10 cm ⁻¹ or less.
The length and number density of the voids in the above-described strand are realized by appropriately adjusting the average particle diameter of silica particles present in the strand, the bulk density of the fiber woven fabric, and the like.

2. Laminated plate Next, the laminated plate will be described.
The laminate of the present invention is obtained by curing the prepreg according to the present invention. Moreover, it is preferable that the laminated board of this invention has a conductor layer installed in the at least one outer surface of the said prepreg based on this invention.
One prepreg may be used, or a laminate in which two or more prepregs are stacked may be used. In the case of a laminated board (hereinafter sometimes referred to as “metal-clad laminated board”) in which a conductor layer is installed, a metal foil is laminated on the above-mentioned prepreg and obtained by heating and pressing. When using a single prepreg, the metal foil is stacked on both upper and lower surfaces or one side, and when using a laminate in which two or more prepregs are stacked, the metal foil is stacked on the outermost upper and lower surfaces or one side of the laminate. . Next, a metal-clad laminate can be obtained by heat-pressing a laminate of a prepreg and a metal foil.

Examples of the metal foil include copper, copper alloy, aluminum, aluminum alloy, silver, silver alloy, gold, gold alloy, zinc, zinc alloy, nickel, nickel alloy, tin, tin alloy, Metal foils, such as iron and an iron-type alloy, are mentioned. Moreover, you may form conductor layers, such as the above coppers and copper-type alloys, by plating.

In the production of the metal-clad laminate, the heating temperature is not particularly limited, but is preferably 120 to 220 ° C, particularly preferably 150 to 200 ° C. The pressure to be applied is not particularly limited, but is preferably 0.5 to 5 MPa, and particularly preferably 1 to 3 MPa. If necessary, post-curing may be performed at a temperature of 150 to 300 ° C. in a high-temperature bath or the like.

Moreover, as another method for producing the metal-clad laminate of the present invention, a method for producing a metal-clad laminate using the metal foil with a resin layer shown in FIG. First, a metal foil 10 with a resin layer in which a uniform resin layer 12 is coated on a metal foil 11 with a coater is prepared. Next, the metal foils 10 and 10 with the resin layer are arranged on both sides of the fiber woven fabric 20 with the resin layer 12 inside (FIG. 1 (a)), heated in a vacuum at 60 to 130 ° C., pressure 0. The laminate is impregnated at 1 to 5 MPa. Thereby, the prepreg 41 with a metal foil is obtained (FIG. 1B). Next, the metal-clad laminate 51 can be obtained by directly heating and pressing the prepreg 41 with metal foil (FIG. 1C).

Furthermore, another method for producing the metal-clad laminate of the present invention includes a method for producing a metal-clad laminate using the polymer film sheet with a resin layer shown in FIG. First, a polymer film sheet 30 with a resin layer in which a uniform resin layer 32 is coated on a polymer film sheet 31 with a coater is prepared. Next,

polymer film sheets

30 and 30 with a resin layer are arranged on both sides of the fiber woven fabric 20 with the resin layer 32 inside (FIG. 2A), heated in a vacuum at 60 to 130 ° C., and pressurized 0 Impregnation with laminate at 1-5 MPa. Thereby, the prepreg 42 with a polymer film sheet can be obtained (FIG.2 (b)). Next, after peeling the polymer film sheet 31 on at least one side of the prepreg 42 with the polymer film sheet (both sides are peeled in FIG. 2C), the metal foil 11 is arranged on the surface from which the polymer film sheet 31 is peeled ( FIG. 2 (d)), heating and pressing. Thereby, the metal-clad laminated board 52 can be obtained (FIG.2 (e)). Furthermore, when peeling a double-sided polymer film sheet, two or more sheets can be laminated | stacked like the above-mentioned prepreg. When two or more prepregs are laminated, a metal-clad laminate can be obtained by placing a metal foil or a polymer film sheet on the upper and lower surfaces or one side of the outermost side of the laminated prepreg and then heat-pressing it. The metal-clad laminate obtained by such a manufacturing method has high thickness accuracy, uniform thickness, and excellent surface smoothness. In addition, since a metal-clad laminate having a small molding strain can be obtained, a printed wiring board and a semiconductor device manufactured using the metal-clad laminate obtained by the manufacturing method have small warpage and small warpage variation. Furthermore, a printed wiring board and a semiconductor device can be manufactured with high yield.

The conditions for the heat and pressure molding are not particularly limited, but are preferably 120 to 250 ° C, and more preferably 150 to 220 ° C. The pressure to be pressurized is not particularly limited, but is preferably 0.1 to 5 MPa, and particularly preferably 0.5 to 3 MPa. Further, if necessary, post-curing may be performed at a temperature of 150 to 300 ° C. in a high-temperature bath or the like.

The metal-clad laminate shown in FIGS. 1 and 2 is not particularly limited. For example, the metal-clad laminate is produced using an apparatus for producing a metal foil with a resin layer and an apparatus for producing a metal-clad laminate.
In the apparatus for producing the metal foil with a resin layer, the metal foil can be supplied by, for example, using a long sheet product in the form of a roll, and thereby continuously unwinding. A predetermined amount of the resin varnish is continuously supplied onto the metal foil by the resin supply device. Here, as the resin varnish, a coating solution in which the resin composition of the present invention is dissolved and dispersed in a solvent is used. The coating amount of the resin varnish can be controlled by the clearance between the comma roll and the backup roll of the comma roll. The metal foil coated with a predetermined amount of the resin varnish is transferred inside the horizontal conveyance type hot air drying device, and substantially removes and removes the organic solvent contained in the resin varnish. It can be set as the metal foil with a resin layer which advanced the hardening reaction to the middle. The metal foil with the resin layer can be wound up as it is, but with a laminate roll, a protective film is superimposed on the side on which the resin layer is formed, and the metal foil with the resin layer on which the protective film is laminated is wound up, A metal foil with an insulating resin layer is obtained. When the manufacturing method shown in FIGS. 1 and 2 is used, since the control of the uniform resin amount and the in-plane thickness accuracy are superior to the conventional manufacturing method impregnated with varnish, the variation in warping of the semiconductor device on which the semiconductor element is mounted is reduced. Small and yield is improved.

Moreover, when a metal-clad laminate is obtained by such a manufacturing method, it is necessary to consider the impregnation property of the resin composition into the fiber woven fabric. The use of silica particles with an average particle size of 5 to 100 nm as the filler improves the impregnation of the fiber base material in particular, so that the flow of the resin composition in the metal-clad laminate is suppressed during hot pressing. Since uneven movement of the molten resin is suppressed, streaky unevenness on the surface of the metal-clad laminate can be prevented and the thickness can be made uniform.

3. Next, the printed wiring board of the present invention will be described.
The printed wiring board of the present invention uses the above prepreg and / or the above laminated board as an inner layer circuit board.
Or the printed wiring board of this invention uses said prepreg for the insulating layer on an inner-layer circuit.
In the case of the printed wiring board using the prepreg of the present invention or the laminated board of the present invention for the inner layer circuit board, the layer formed by curing the prepreg in the inner layer circuit board is an insulating layer.

In the present invention, the printed wiring board is a conductor circuit layer formed by providing a conductive layer such as a metal foil on an insulating layer. A single-sided printed wiring board (single-layer board), a double-sided printed wiring board (double-layer board) ) And multilayer printed wiring boards (multilayer boards). A multilayer printed wiring board is a printed wiring board that is laminated in three or more layers by a plated through hole method, a build-up method, or the like, and can be obtained by heating and press-molding an insulating layer on an inner circuit board. . As said inner-layer circuit board, what uses the laminated board of this invention and / or the prepreg of this invention can be used, for example. As an inner layer circuit board using the laminated board of the present invention, for example, a conductive circuit having a predetermined pattern is formed on the laminated board of the present invention having no metal foil by a semi-additive method, and the conductive circuit portion is blackened. The conductor circuit of a predetermined pattern is formed on the metal foil of the metal-clad laminate of the present invention, and the conductor circuit portion is blackened.
In addition, as an inner layer circuit board using the prepreg of the present invention, electric / electronic parts such as capacitors, resistors, and chips are mounted on an insulating support made of a cured resin, and the prepreg of the present invention is mounted thereon. It is also possible to use a conductive circuit having a predetermined pattern formed by a semi-additive method or the like on a component-embedded substrate obtained by laminating and curing by heating and pressing and blackening the conductive circuit portion.
Furthermore, in the present invention, the prepreg of the present invention is further laminated on the inner layer circuit board using the laminate of the present invention and / or the prepreg of the present invention, or a conductor circuit of a conventionally known inner layer circuit board. And what was heat-pressed-hardened can also be used as an inner-layer circuit board. As the insulating layer on the inner layer circuit, the prepreg of the present invention can be used. In addition, when using the prepreg of this invention as an insulating layer on the said inner layer circuit, the said inner layer circuit board does not need to consist of the prepreg or laminated board of this invention.

Hereinafter, as a representative example of the printed wiring board of the present invention, a multilayer printed wiring board in which the metal-clad laminate of the present invention is used as an inner circuit board and the prepreg of the present invention is used as an insulating layer will be described.
The inner layer circuit board is produced by forming a conductor circuit of a predetermined pattern on one side or both sides of the metal-clad laminate and blackening the conductor circuit portion. The formation method of the said conductor circuit is not specifically limited, It can carry out by well-known methods, such as a subtractive method, an additive method, and a semi-additive method. Further, through holes can be formed in the inner layer circuit board by drilling, laser processing or the like, and electrical connection on both sides can be established by plating or the like. Since the inner layer circuit board is made of the metal-clad laminate of the present invention, it is possible to form through holes with excellent accuracy in hole diameter, shape, etc., particularly by laser processing. As the laser, an excimer laser, a UV laser, a carbon dioxide gas laser, or the like can be used.

Next, the prepreg is superposed on the inner layer circuit board, heat-pressed, and further heat-cured to form an insulating layer. Specifically, the prepreg and the inner layer circuit board are overlapped and vacuum heated and pressed using a vacuum pressurizing laminator device or the like, and then the insulating layer is heated and cured with a hot air dryer or the like. Here, the conditions for heat and pressure molding are not particularly limited, but for example, it can be carried out at a temperature of 60 to 160 ° C. and a pressure of 0.2 to 3 MPa. Further, the conditions for heat curing are not particularly limited, but for example, it can be carried out at a temperature of 140 to 240 ° C. for a time of 30 to 120 minutes.

Next, the laminated insulating layer is irradiated with laser to form an opening (via hole). The said laser can use the thing similar to the laser used for through-hole formation. Since the insulating layer is made of the prepreg of the present invention, it is possible to form an aperture having excellent precision such as hole diameter and shape by laser processing.

The resin residue (smear) after laser irradiation is preferably removed by an oxidizing agent such as permanganate or dichromate, that is, desmear treatment. If the desmear treatment is insufficient and the desmear property is not sufficiently secured, even if metal plating is applied to the aperture, the electrical conductivity between the upper and lower conductor circuit layers is sufficient due to smear. May not be secured. Also, since the surface of the smooth insulating layer can be roughened at the same time by performing desmear treatment, when the conductor layer is formed on the surface of the insulating layer by metal plating, the adhesion between the surface of the insulating layer and the conductor layer Excellent in properties. Note that a conductor layer may be formed on the surface of the insulating layer before the opening is formed by laser irradiation.

Next, a metal plating process is performed on the opening portion and the insulating layer surface to form a conductor layer. A conductor circuit is further formed on the surface of the insulating layer by the above-described known method. In addition, continuity with an upper conductor circuit layer and a lower conductor circuit layer can be aimed at by performing a metal plating process to an opening part and forming a conductor layer.

Further, an insulating layer may be further laminated and a conductor circuit may be formed in the same manner as described above. However, in a multilayer printed wiring board, a solder resist film is formed on the outermost layer after the conductor circuit is formed. The method for forming the solder resist film is not particularly limited. For example, a method of forming a dry film type solder resist by laminating (laminating), exposing and developing, or printing a liquid resist by exposing and developing. This is done by the forming method. When the obtained multilayer printed wiring board is used in a semiconductor device, a connection electrode portion is provided for mounting a semiconductor element. The connection electrode portion can be appropriately coated with a metal film such as gold plating, nickel plating, or solder plating.

4). Semiconductor Device Next, the semiconductor device of the present invention will be described.
A semiconductor element having solder bumps is mounted on the printed wiring board obtained above, and connection to the printed wiring board is attempted through the solder bumps. Then, a sealing resin is filled between the printed wiring board and the semiconductor element to form a semiconductor device. The solder bump is preferably made of an alloy made of tin, lead, silver, copper, bismuth or the like.

The method for connecting the semiconductor element and the printed wiring board is to use a flip chip bonder or the like to align the connection electrode portion on the printed wiring board with the solder bumps of the semiconductor element, and then the IR reflow apparatus, the hot plate In addition, the solder bumps are heated to the melting point or higher by using other heating devices, and the printed wiring board and the solder bumps are connected by fusion bonding. In order to improve connection reliability, a metal layer having a relatively low melting point, such as solder paste, may be formed in advance on the connection electrode portion on the printed wiring board. Prior to this joining step, the connection reliability can be improved by applying a flux to the surface layer of the connection electrode portion on the solder bump and / or printed wiring board.

Hereinafter, the present invention will be described in detail based on examples and comparative examples, but the present invention is not limited thereto.

The fiber woven fabrics used in the examples and comparative examples are woven fabrics obtained by weaving glass fibers stipulated in JIS R3413, and are the following glass fiber woven fabrics A to L.
A: Glass fiber yarn of T glass and E110 1/0 was used, and the number of warps and wefts to be driven per 25 mm was 44.5 and 42, the thickness was 130 μm after opening and flattening, and the basis weight was 155 g / m ^2.
B: Using E glass, DE150 1/0 glass fiber yarn, the number of warps and wefts to be driven per 25 mm is 46.5, 44, the thickness is 95 μm after opening and flattening, and the basis weight is 121 g / m ^2.
C: T glass, using a glass fiber yarn E 225 1/0, implantation number per warp and weft of 25mm is 65 present, 64, opening-flattened treated thickness 95 .mu.m, basis weight 121g / ^{m 2}
D: D glass, glass fiber yarn of E225 1/0, the number of warps and wefts to be driven per 25 mm is 65 or 64, the thickness is 95 μm after opening and flattening, and the basis weight is 121 g / m ²
E: Glass fiber yarn of T glass and D450 1/0 was used, and the number of warps and wefts to be driven per 25 mm was 59, 59, the thickness was 46 μm after opening and flattening, and the basis weight was 53 g / m ^2.
F: Using T glass, BC1500 1/0 glass fiber yarn, the number of warps and wefts to be driven per 25 mm is 90, 90, thickness 20 μm after opening and flattening, basis weight 24 g / m ²
G: T glass, C1200 1/0 glass fiber yarn is used, and the number of warps and wefts to be driven per 25 mm is 74, 77, the thickness is 25 μm after opening and flattening, and the basis weight is 31 g / m ^2.
H: T glass, glass fiber yarn of E110 1/0 was used, and the number of warps and wefts driven per 25 mm was 44.5, 42, the thickness was 115 μm after opening and flattening, and the basis weight was 155 g / m ^2.
I: Using T glass, E110 1/0 glass fiber yarn, the number of warps and wefts to be driven per 25 mm is 43 or 40, the thickness is 145 μm after opening and flattening, and the basis weight is 150 g / m ^2.
J: T glass, E225 1/0 glass fiber yarn, 59 and 54 warp yarns and weft yarns per 25 mm, thickness of 97 μm after opening and flattening, basis weight of 100 g / m ²
K: T glass, D450 1/0 glass fiber yarn, the number of warps and wefts to be driven per 25 mm was 60, 47, the thickness was 50 μm after opening and flattening, and the basis weight was 48 g / m ^2.
L: T glass, glass fiber yarn of C1200 1/0, the number of warps and wefts to be driven per 25 mm is 68 or 72, the thickness is 27 μm after opening and flattening, and the basis weight is 25 g / m ^2.

The varnishes used in the examples and comparative examples were produced by containing and mixing the resin composition in a solvent according to the following varnish production examples 1 to 7.
(Varnish production example 1)
6 parts by weight of an epoxy resin (HP-5000 manufactured by DIC), 12 parts by weight of a phenol novolac cyanate resin (PT30 manufactured by Lonza), 6 parts by weight of a phenol-based curing agent (MEH-7851-4L manufactured by Meiwa Kasei Co., Ltd.) 10 parts by weight of silica particles (NSS-5N manufactured by Tokuyama Corporation, average particle size 70 nm), 65 parts by weight of spherical silica (SO-31R manufactured by Admatechs, average particle diameter 1.0 μm), epoxy silane (Shin-Etsu Chemical Co., Ltd.) (Production KBM-403E) 1.0 part by weight was contained and mixed in methyl ethyl ketone and stirred using a high-speed stirrer to obtain a varnish whose epoxy resin composition was 70% by weight based on the solid content. In addition, when the whole filler contained in the resin composition contained / mixed in the varnish was 100% by mass, the silica particles contained in the filler were 13% by mass, and the spherical silica was 87% by mass.

(Varnish production example 2)
As epoxy resins, 9 parts by weight of biphenyl aralkyl type epoxy resin (NC-3000, manufactured by Nippon Kayaku Co., Ltd.), 17 parts by weight of bismaleimide resin (BMI-70, manufactured by Keiai Chemical Industry Co., Ltd.), 3 parts by weight of 4,4′-diaminodiphenylmethane 10 parts by weight of silica particles (NSS-5N manufactured by Tokuyama Corporation, average particle size 70 nm), 60 parts by weight of boehmite (BMB manufactured by Kawai Lime Co., Ltd., average particle size 0.5 μm), epoxy silane (KBM- manufactured by Shin-Etsu Chemical Co., Ltd.) 403E) 1.0 part by weight was contained and mixed in dimethylformamide. Subsequently, it stirred using the high-speed stirring apparatus and adjusted so that it might become 70 weight% of non volatile matters, and prepared the resin varnish. In addition, when the whole filler contained in the resin composition contained / mixed in the varnish was 100% by mass, the silica particles contained in the filler were 14% by mass and boehmite was 86% by mass.

(Varnish production example 3)
Biphenyl aralkyl type epoxy resin (Nippon Kayaku Co., Ltd. NC-3000FH) 20 parts by weight, Naphthalene type epoxy resin (DIC Co., Ltd. HP4032D) 5 parts by weight, Cyanate resin (Toto Kasei Co., Ltd. SN485 derivative, naphthol type ) 17 wt., Bismaleimide resin (BMI-70 manufactured by KAI Kasei Kogyo Co., Ltd.) 7.5 wt%, silica particles (NSS-5N manufactured by Tokuyama Co., Ltd., average particle size 70 nm), 7 parts by weight, spherical silica (manufactured by Admatechs) SO-31R, average particle size 1.0 μm) 35.5 parts by weight, silicone particles (Shin-Etsu Chemical Co., Ltd. KMP600, average particle size 5 μm) 7.5 parts by weight, zinc octylate 0.01 weight, epoxy silane 0.5 wt. (KBM-403E manufactured by Shin-Etsu Chemical Co., Ltd.) was contained and mixed in methyl ethyl ketone. Subsequently, it stirred using the high-speed stirring apparatus and adjusted so that it might become 70 weight% of non volatile matters, and prepared the resin varnish. When the entire filler contained in the resin composition contained / mixed in the varnish is 100% by mass, the silica particles contained in the filler are 14% by mass, the spherical silica is 71% by mass, and the silicone particles are 15% by mass. %Met.

(Varnish production example 4)
As the epoxy resin, 18.5 parts by weight of a biphenyl aralkyl type epoxy resin (NC-3000 manufactured by Nippon Kayaku Co., Ltd.), 34.9 parts by weight of a bismaleimide resin (BMI-70 manufactured by Keiai Kasei Kogyo Co., Ltd.), 4,4′-diamino 6.1 parts by weight of diphenylmethane, 5 parts by weight of silica particles (NSS-5N manufactured by Tokuyama Co., Ltd., average particle size 70 nm), 35 parts by weight of boehmite (BMB manufactured by Kawai Lime Co., Ltd., average particle size 0.5 μm), epoxy silane (Shin-Etsu) 0.5 parts by weight of KBM-403E manufactured by Kagaku Kogyo Co., Ltd. was contained and mixed in dimethylformamide. Subsequently, it stirred using the high-speed stirring apparatus and adjusted so that it might become 70 weight% of non volatile matters, and prepared the resin varnish. In addition, when the whole filler contained in the resin composition contained / mixed in the varnish was 100% by mass, the silica particles contained in the filler were 12.5% by mass and boehmite was 87.5% by mass. .

(Varnish production example 5)
As epoxy resins, biphenyl aralkyl type epoxy resin (NC-3000 manufactured by Nippon Kayaku Co., Ltd.) 2.80 parts by weight, bismaleimide resin (BMI-70 manufactured by KAI Kasei Kogyo Co., Ltd.) 5.27 parts by weight, 4,4′-diamino 0.93 parts by weight of diphenylmethane, 10 parts by weight of silica particles (NSS-5N manufactured by Tokuyama Corporation, average particle size 70 nm), 80 parts by weight of boehmite (BMB manufactured by Kawai Lime Co., Ltd., average particle size 0.5 μm), epoxy silane (Shin-Etsu) 1.0 part by weight of KBM-403E manufactured by Kagaku Kogyo Co., Ltd. was contained and mixed in dimethylformamide. Subsequently, it stirred using the high-speed stirring apparatus and adjusted so that it might become 70 weight% of non volatile matters, and prepared the resin varnish. In addition, when the whole filler contained in the resin composition contained / mixed in the varnish was 100% by mass, the silica particles contained in the filler were 11% by mass and boehmite was 89% by mass.

(Varnish production example 6)
6 parts by weight of an epoxy resin (HP-5000 manufactured by DIC), 12 parts by weight of a phenol novolac cyanate resin (PT30 manufactured by Lonza), 6 parts by weight of a phenol-based curing agent (MEH-7851-4L manufactured by Meiwa Kasei Co., Ltd.) 30 parts by weight of silica particles (NSS-5N manufactured by Tokuyama Corporation, average particle size 70 nm), 45 parts by weight of spherical silica (SO-31R manufactured by Admatechs, average particle diameter 1.0 μm), epoxy silane (Shin-Etsu Chemical Co., Ltd.) (Production KBM-403E) 1.0 part by weight was contained and mixed in methyl ethyl ketone and stirred using a high-speed stirrer to obtain a varnish whose epoxy resin composition was 70% by weight based on the solid content. In addition, when the whole filler contained in the resin composition contained / mixed in the varnish was 100 mass%, the silica particles contained in the filler were 40 mass%, and the spherical silica was 60 mass%.

(Varnish production example 7)
6 parts by weight of epoxy resin (NC-3000 manufactured by Nippon Kayaku Co., Ltd.), 12 parts by weight of phenol novolac cyanate resin (PT30 manufactured by Lonza), 6 parts by weight of phenolic curing agent (MEH-7851-4L manufactured by Meiwa Kasei Co., Ltd.) Part of spherical silica (SO-31R manufactured by Admatechs Co., Ltd., average particle size 1.0 μm) and 75 parts by weight of epoxy silane (KBM-403E manufactured by Shin-Etsu Chemical Co., Ltd.) are contained and mixed in methyl ethyl ketone. The mixture was stirred using a high-speed stirrer to obtain a varnish having an epoxy resin composition having a solid content of 70% by weight. In addition, when the whole filler contained in the resin composition contained / mixed in the varnish was 100% by mass, the silica particles contained in the filler were 0% by mass, and the spherical silica was 100% by mass.

Table 1 shows the compositions of the resin compositions used in Varnish Production Examples 1 to 7. In addition, the compounding quantity of each component is shown by a weight part.

Using the glass fiber woven fabric and the varnish, a prepreg, a metal-clad laminate, a printed wiring board (inner layer circuit board), a multilayer printed wiring board, and a semiconductor device were produced.

<Example 1>
(1) Preparation of prepreg The varnish obtained in Production Example 1 was cast coated on a 38 μm thick polyethylene terephthalate substrate (hereinafter referred to as “PET substrate”), and the solvent was evaporated and dried at a temperature of 140 ° C. for 10 minutes. The thickness of the resin layer was 30 μm. The base material with the resin layer is arranged on both surfaces of the glass woven fabric A so that the resin layer is in contact with the glass woven fabric, and a vacuum and pressure laminator (Meiki Seisakusho Co., Ltd.) under the conditions of a pressure of 0.5 MPa and a temperature of 140 ° C. for 1 minute. The resin composition was impregnated by heating and pressing with MLVP-500). As a result, a 150 μm-thick prepreg (resin layer (one side): 10 μm, fiber woven fabric layer: 130 μm) having a PET substrate on both sides was obtained.

(2) Production of metal-clad laminate A 2 μm copper foil with carrier (Micro thin MT18Ex-2, manufactured by Mitsui Mining & Smelting Co., Ltd.) was layered on both sides of the prepreg, and heated and pressed at a pressure of 3 MPa and a temperature of 220 ° C. for 2 hours. did. As a result, a metal-clad laminate having copper foil on both surfaces of a 150 μm thick insulating layer formed by curing the prepreg was obtained.

(3) Preparation of prepreg for multilayer printed wiring board insulating layer Glass woven fabric (thickness 16 μm, unit E glass woven fabric, E02Z, basis weight 17.5 g / m ² ) obtained in Production Example 1 And dried in a heating furnace at 180 ° C. for 2 minutes to obtain a prepreg (thickness: 40 μm) having a resin composition in the prepreg of about 78% by weight based on the solid content. The glass woven fabric had a bulk density of 1.09 g / cm ³ , an air permeability of 41 cc / cm ² / sec, and a flatness ratio (thickness: width) of 1:16. The glass woven fabric is made of glass fiber having a Young's modulus of 93 GPa when formed into a plate, a tensile strength of 48 GPa when formed into a plate, and a tensile strength of 90 N / 25 mm in the longitudinal direction when formed into a fiber woven fabric. It was.

(4) Manufacture of printed wiring board (inner layer circuit board) The carrier foil is peeled off from the metal-clad laminate, and an aperture φ1.4 mm, beam diameter using a carbon dioxide laser (ML605GTX3-5100U2 manufactured by Mitsubishi Electric Corporation) A through-through hole of φ100 μm was formed under the conditions of about 120 μm, energy 7-9 mJ, and number of shots 6. Next, the metal-clad laminate was immersed in a swelling liquid at 70 ° C. (Atotech Japan, Swelling Dip Securigant P) for 5 minutes, and further an aqueous potassium permanganate solution at 80 ° C. (concentrated by Atotech Japan). After immersion in compact CP) for 10 minutes, neutralization and roughening treatment were performed. Next, conduction between the upper and lower copper foils was achieved by electroless plating (manufactured by Uemura Kogyo Co., Ltd., Sulcup PEA process).
Next, a 25 μm-thick UV-sensitive dry film (manufactured by Asahi Kasei Co., Ltd., Sunfort UFG-255) was bonded to the surface of the electroless plating layer with a hot roll laminator. Next, the position of a glass mask (manufactured by Topic) on which a pattern having a minimum line width / line spacing of 20/20 μm was drawn was aligned. Next, the glass mask was used for exposure with an exposure apparatus (Ono Sokki EV-0800), followed by development with an aqueous sodium carbonate solution to form a resist mask. Next, electrolytic copper plating (Okuno Pharmaceutical 81-HL) was performed at 3 A / dm ² for 25 minutes using the electroless plating layer as a power feeding layer electrode. Thus, a copper wiring pattern having a thickness of about 20 μm was formed. Next, the resist mask was peeled off with a monoethanolamine solution (R-100, manufactured by Mitsubishi Gas Chemical Company) using a peeling machine. Then, unnecessary copper foil and electroless plating layer other than the pattern shape as the power feeding layer are removed by flash etching (pure aqueous solution of SAC-702M and SAC-701R35 manufactured by Ebara Densan Co., Ltd.), and L / S = 20 / A 20 μm pattern was formed.
Next, the conductor circuit was roughened (MEC Etch Bond CZ-8100, manufactured by MEC). The roughening treatment was performed by spray spraying under conditions of a liquid temperature of 35 ° C. and a spray pressure of 0.15 MP, and roughening the copper surface to a roughness of about 3 μm. Next, a surface treatment of the conductor circuit (MEC Etch Bond CL-8300, manufactured by MEC) was performed. In the surface treatment, the copper surface was subjected to rust prevention treatment by dipping under conditions of a liquid temperature of 25 ° C. and an immersion time of 20 seconds. In this way, a printed wiring board (inner layer circuit board) was produced.

(5) Manufacture of multilayer printed wiring board Next, the printed wiring board obtained above is used as an inner layer circuit board, and the multilayer printed wiring board insulating layer prepreg and a 2 μm copper foil with a carrier (Mitsui Metal Mining Co., Ltd.) Manufactured by Micro Thin MT18Ex-2), stacked using a stacking vacuum stacking apparatus, and cured by heating at a temperature of 200 ° C., a pressure of 3 MPa, and a time of 120 minutes to obtain a multilayer stack. Next, outer layer circuit formation is performed in the same manner as in the method for producing the printed wiring board (inner layer circuit board) (4), and finally a solder resist (manufactured by Taiyo Ink, PSR4000 / AUS308) is formed on the circuit surface. A printed wiring board was obtained.

The multilayer printed wiring board was subjected to the ENEPIG treatment on the connection electrode portion corresponding to the solder bump arrangement of the semiconductor element. ENEPIG treatment includes [1] cleaner treatment, [2] soft etching treatment, [3] pickling treatment, [4] pre-dip treatment, [5] palladium catalyst application, [6] electroless nickel plating treatment, [7] The electroless palladium plating treatment and [8] electroless gold plating treatment were performed.

(6) Manufacture of Semiconductor Device A semiconductor device is a semiconductor device (TEG chip, size 10 mm × 10 mm, thickness 0.1 mm) having solder bumps on a printed wiring board subjected to ENEPIG processing, by a flip chip bonder device. After mounting by thermocompression bonding, solder bumps were melt-bonded in an IR reflow furnace, and then liquid sealing resin (manufactured by Sumitomo Bakelite Co., Ltd., CRP-4152S) was filled and the liquid sealing resin was cured. . The liquid sealing resin was cured at a temperature of 150 ° C. for 120 minutes. In addition, the solder bump of the said semiconductor element used what was formed with the eutectic of Sn / Pb composition. Finally, it was separated into pieces of 14 mm × 14 mm with a router to obtain a semiconductor device.

<Examples 2 to 3 and Comparative Examples 1 to 6>
Using the woven fabric and the varnish obtained by the production example of varnish shown in Table 4, a prepreg as in Example 1, a metal-clad laminate having copper foil on both surfaces of an insulating layer having a thickness of 150 μm, and a printed wiring board (Inner layer circuit board), multilayer printed wiring board and semiconductor device were obtained.

<Examples 4 to 6 and Comparative Example 7>
Example 1 using the varnish obtained by the production example of the fiber woven fabric and the varnish shown in Table 5 except that the thickness of the resin layer of the substrate with the resin layer was set as shown in Table 5 at the time of preparing the prepreg. In the same manner as above, a prepreg, a metal-clad laminate having copper foil on both sides of an insulating layer having a thickness of 100 μm, a printed wiring board (inner circuit board), a multilayer printed wiring board, and a semiconductor device were obtained.
In addition, the through-hole formation of the printed wiring board was performed using a carbon dioxide laser (Mitsubishi Electric Corporation, ML605GTX3-5100U2) under the conditions of an aperture φ1.1 mm, a beam diameter of about 110 μm, energy 7 to 9 mJ, and shot number 6. A through-hole having a diameter of 100 μm was formed.

<Examples 7 and 8 and Comparative Example 8>
Example 7 and Comparative Example 8 are obtained by the production examples of the fiber woven fabric and varnish shown in Table 6 except that the thickness of the resin layer of the substrate with the resin layer is as shown in Table 6 at the time of preparing the prepreg. As in Example 1, a prepreg, a metal-clad laminate having copper foil on both sides of an insulating layer having a thickness of 60 μm, a printed wiring board (inner circuit board), a multilayer printed wiring board, and a semiconductor device were obtained. It was.
Example 8 uses the varnish obtained by the production example of the fiber woven fabric and the varnish shown in Table 6 except that the thickness of the resin layer of the substrate with the resin layer is as shown in Table 6 at the time of preparing the prepreg. As in Example 1, a prepreg (total thickness 30 μm), a metal-clad laminate having copper foil on both sides of a 60 μm thick insulating layer obtained by laminating and curing two 30 μm prepregs, an inner circuit board A multilayer printed wiring board and a semiconductor device were obtained.
In addition, the through-hole formation of the printed wiring board was performed using a carbon dioxide gas laser (ML605GTX3-5100U2 manufactured by Mitsubishi Electric Corporation) under the conditions of an aperture φ1.1 mm, a beam diameter of about 110 μm, energy 6 to 8 mJ, and shot number 6 A through-hole having a diameter of 100 μm was formed.

<Example 9 and Comparative Example 9>
Example 1 using the varnish obtained by the production example of the fiber woven fabric and varnish shown in Table 7 except that the thickness of the resin layer of the substrate with the resin layer was set as shown in Table 7 at the time of preparing the prepreg. In the same manner as above, a prepreg, a metal-clad laminate having copper foil on both sides of an insulating layer having a thickness of 40 μm, a printed wiring board (inner layer circuit board), a multilayer printed wiring board, and a semiconductor device were obtained.
In addition, the through-hole formation of the printed wiring board was performed using a carbon dioxide gas laser (ML605GTX3-5100U2 manufactured by Mitsubishi Electric Corporation) under the conditions of an aperture φ1.1 mm, a beam diameter of about 110 μm, energy 6 to 8 mJ, and shot number 6 A through-hole having a diameter of 100 μm was formed.

The following evaluation was performed on the prepregs, metal-clad laminates, printed wiring boards (inner circuit boards) and semiconductor devices obtained in the examples and comparative examples. The evaluation items are shown together with the contents. The obtained evaluation results are shown in Tables 4 to 7.
In addition, since the measurement result of the PKG warpage described later depends on the thickness of the insulating layer of the metal-clad laminate, the evaluation results of Examples and Comparative Examples in which the thickness of the insulating layer of the metal-clad laminate is 150 μm are shown in Table 4, Table 5 shows the evaluation results of Examples and Comparative Examples in which the thickness of the insulating layer of the metal-clad laminate is 100 μm, and Table 6 shows the evaluation results of Examples and Comparative Examples in which the thickness of the insulating layer of the metal-clad laminate is 60 μm. Table 7 shows the evaluation results of Examples and Comparative Examples in which the thickness of the insulating layer of the metal-clad laminate is 40 μm.
In Tables 4 to 7, the amount of filler (% by mass) in the resin composition indicates the amount of filler when the entire resin composition is 100% by mass. (Mass)% shows the ratio of each component when the whole filler is 100 mass%.

<Evaluation method>
(1) Impregnation of resin composition The prepregs obtained in the examples and comparative examples were cured for 1 hour at a temperature of 170 ° C., and then the cross section (about the range of the cross section 300 mm in the width direction) was SEM (scanning electron) And the presence or absence of voids inside the fiber was evaluated. Voids are observed as white granular points on the fiber cross section on the image.
Each code is as follows.
○: When the resin composition is fully impregnated and there is no void inside the fiber ×: When there is a void inside the fiber

(2) Formability After etching the copper foil of the metal-clad laminate obtained in the examples and comparative examples, a 500 mm × 500 mm range was observed with a SEM (scanning electron microscope), and an insulating layer (fiber woven) The presence or absence of voids on the surface of the resin layer on the surface of the fabric layer was evaluated. Voids are observed as white granular points on the image.
Each code is as follows.
○: No void ×: Void present

(3) Heat-absorbing solder heat resistance Using samples obtained by cutting the metal-clad laminates obtained in the examples and comparative examples into 50 mm × 50 mm squares, based on JIS C-6481, other than half of one side of the samples All copper foil is removed by etching, treated with a pressure checker tester (manufactured by Espec Corp.) at 121 ° C and 2 atm for 2 hours, and then immersed in a solder bath at 260 ° C for 30 seconds to check for abnormal appearance changes. It was observed visually.
Each code is as follows.
○: No abnormality ×: Swelling or peeling

(4) Linear thermal expansion coefficient (CTE) (ppm / K)
The coefficient of linear thermal expansion (CTE) was measured using a TMA (thermomechanical analysis) apparatus (TA Instruments, Q400) to produce a 4 mm × 20 mm test piece, and a temperature range of 30 to 300 ° C. and 10 ° C. The CTE at 50 to 100 ° C. in the second cycle was measured under the conditions of / min and a load of 5 g. In addition, the sample used what removed the copper foil of the metal-clad laminated board obtained by each Example and the comparative example by etching.

(5) Laser workability Using the printed wiring boards (inner circuit boards) obtained in the examples and comparative examples, the cross protrusion amount of through-through holes and the roundness of the hole diameter after carbonic acid laser processing were measured. The cross protrusion amount and roundness are measured using a color 3D laser microscope (manufactured by Keyence Corporation, device name VK-9710), and the cross protrusion amount is measured from directly above the hole on the laser incident side. The roundness is measured by observing from above the hole on the laser incident side, measuring the major axis and minor axis of the hole top diameter, and calculating the major axis ÷ minor axis. Went by. In addition, the sample used the printed wiring board (inner layer circuit board) obtained by the said Example and the comparative example, and observed the board | substrate just after the hole process of diameter 100micrometer on the carbon dioxide laser conditions shown in following Table 2. And it was set as the average value of ten through-holes.

Each code is as follows.
◯: When the cross protrusion amount is within 10 μm and the roundness is 0.85 or more Δ: When the cross protrusion amount is 10 μm or more, or the roundness is less than 0.85 ×: Cross protrusion amount When the diameter is 10 μm or more and the roundness is less than 0.85

(6) Insulation reliability of through-holes Using the printed wiring boards (inner layer circuit boards) obtained in the examples and comparative examples, the insulation reliability between through-through holes was evaluated.
Evaluation was made by continuous measurement under conditions of an applied voltage of 10 V, a temperature of 130 ° C. and a humidity of 85%, using a 0.1 mm portion between through-hole walls of the printed wiring board. The measurement was performed using a highly accelerated life test apparatus (EHS-211 (M) manufactured by Espec Corp., AMI ion migration system), and the measurement was terminated when the insulation resistance value was less than 10 ⁸ Ω.
Each code is as follows.
A: More than 200 hours.
A: 100 hours or more and 200 or less.
(Triangle | delta): It was 50 hours or more and less than 100 hours.
X: It was less than 50 hours.

(7) PKG warpage The semiconductor device (14 mm × 14 mm) obtained in the examples and comparative examples is placed on the surface of the semiconductor element in the sample chamber of a temperature variable laser three-dimensional measuring machine (type LS220-MT100MT50, manufactured by Hitachi Technology & Service Co., Ltd.). The warp of the semiconductor device at room temperature (25 ° C.) and 260 ° C. was measured using the above measuring device. The warpage was measured by measuring the displacement in the height direction, and taking the largest value of the displacement difference as the amount of warpage. The measurement range was 13 mm × 13 mm size.
Each code is as shown in Table 3 below. In addition, since the measurement of the PKG warp depends on the thickness of the insulating layer of the metal-clad laminate, it was determined as shown in Table 3 according to the thickness of the insulating layer of the metal-clad laminate.

As a representative example of the observation result of the impregnating property of the resin composition (1), a photograph of a sectional view of the prepreg obtained in Example 1 is shown in FIG. 3, and a photograph of a sectional view of the prepreg obtained in Comparative Example 4 Is shown in FIG.
As can be seen from FIG. 4, in Comparative Example 4, voids were observed in the fiber woven fabric because the impregnation property of the resin composition was poor. On the other hand, as can be seen from FIG. 3, in Example 1, since the impregnation property of the resin composition was good, there was no void in the fiber woven fabric.
In Example 1, it is considered that the impregnation property of the resin composition was improved by the nano-sized silica particles entering the strand. On the other hand, it can be seen that Comparative Example 4 did not contain nano-sized silica particles, so that the impregnation of the resin composition could not be improved.

As a representative example of the formability observation result of (2) metal-clad laminate, FIG. 5 shows a photograph of the surface of the metal-clad laminate obtained in Example 1 which has been entirely etched, and obtained in Comparative Example 6. FIG. 6 shows a photograph of the entire surface of the copper foil of the metal-clad laminate obtained by etching, and FIG. 7 shows an SEM photograph of an enlarged view of voids (white granular points on the image) observed in FIG. The SEM photograph of the enlarged view of the cross section of the void observed in FIG. 7 is shown in FIG. As can be seen from FIGS. 6, 7, and 8, in Comparative Example 6, voids were observed on the surface where the entire surface of the metal-clad laminate was etched. On the other hand, as can be seen from FIG. 5, in Example 1, there was no void on the etched surface.

9 to 12 are SEM photographs of cross-sectional views showing a part of the strands constituting the prepreg fiber woven fabric obtained in Example 1. FIG. FIG. 9 shows a cross section parallel to the drawing direction of the strand. 10 to 12 show cross sections perpendicular to the strand drawing direction.
As shown in FIGS. 9 to 12, it can be seen that in the prepreg obtained in Example 1, silica particles are present in the strand.

In Examples 1 to 9 shown in Tables 4 to 7, good prepreg impregnation properties were obtained. Moreover, it turns out that the favorable result is obtained also about other various characteristics. This is considered due to the fact that the prepreg was prepared under the condition that the silica particles enter the strands constituting the fiber woven fabric.
Factors that control the entry of silica particles into the strand include, for example, the average particle size of silica particles, the content of silica particles in the filler, the content of filler in the resin composition, and whether the fiber woven fabric is Various things, such as a density, are mentioned.

As can be seen from Tables 4 to 7, in Examples 1 to 9, the resin composition contained in the varnish contains 50 to 85% by mass of the filler in the whole resin composition, and the average particle size of the filler Silica particles having a diameter of 5 to 100 nm were contained in an amount of 1 to 20% by mass, and the bulk density of the fiber woven fabric was 1.05 to 1.30 g / cm ³ . In this case, excellent evaluation results were obtained for all the above evaluation items. That is, the prepreg according to the present example was excellent in the impregnation property of the resin composition with respect to the fiber woven fabric, had low thermal expansibility, had excellent laser processability when used as an insulating layer of a printed wiring board, and was formed by a laser. It has been found that the hole can form a hole with good hole diameter and shape accuracy and with suppressed fiber protrusion. Furthermore, since the prepreg according to the present example is excellent in moisture-absorbing solder heat resistance, it has high heat resistance and excellent moldability, so it can be said that it has excellent surface smoothness and thus excellent adhesion to the conductor layer. . Further, since the PKG warpage in the semiconductor device of the present invention is small, it can be seen that the prepreg according to the present example has low thermal expansion and high rigidity.

Also in Comparative Examples 1 and 6, good prepreg impregnation properties were obtained.
However, in Comparative Example 1, good results were not obtained in CTE and package warpage. This seems to be because the silica particles are prevented from entering the strands because only the resin component of the resin composition enters the strands because the content of the filler is low. As a result, it is considered that the filler could not be highly filled, the CTE of the prepreg was increased, and the package warp occurred.
In Comparative Example 6, good results were not obtained. This is because a sufficient amount of the resin composition can be impregnated due to the low bulk density, so that the silica particles contained in the resin composition are also suppressed from entering the strand. Seem. Moreover, since the bulk density of the fiber woven fabric is small, it becomes a thick fiber base material, so that the thickness of the resin layer on the surface layer of the prepreg becomes thin. For this reason, it is considered that the PKG warp occurred although the moldability and moisture absorption solder heat resistance were poor and the CTE was good.

In Comparative Examples 4 and 7 to 9, good results were not obtained with respect to the impregnation property of the prepreg. In Comparative Examples 4 and 7 to 9, nano-sized silica particles are not contained in the resin composition constituting the prepreg. For this reason, it is considered that the silica particles could not enter the strands and the impregnation of the resin composition could not be improved. In addition, due to this, good results were not obtained in other characteristics such as CTE and package warpage.
In Comparative Example 7, since the bulk density of the fiber woven fabric is small, the laser processability is inferior, and since the impregnation property is poor, the insulation reliability of the through-hole is inferior. In addition, since a relatively thick fiber woven fabric was used, the thickness of the resin layer of the prepreg was reduced, the formability and moisture-absorbing solder heat resistance were inferior, and PKG warping occurred.
In Comparative Examples 8 and 9, since the thickness of the insulating layer of the metal-clad laminate is relatively thin, the moldability, hygroscopic solder heat resistance, and insulation reliability of the through-hole are excellent. However, since the bulk density of the fiber woven fabric is small, good results in laser processability were not obtained.

Also in Comparative Examples 2, 3, and 5, good results were not obtained with respect to the impregnation property of the prepreg. Also, good results were not obtained for other characteristics. In Comparative Example 2, since the filler content is too high, the fluidity of the silica particles in the resin composition cannot be obtained, and as a result, it is considered that the silica particles are prevented from entering the strands. In Comparative Example 3, since the content of the nano-sized silica particles is high, the nano-sized silica particles are aggregated. As a result, it seems that the silica particles are prevented from entering the strand. In Comparative Example 5, since the bulk density of the fiber woven fabric is large, it seems that the silica particles are prevented from entering the strand.
In Comparative Example 5, since the bulk density of the fiber woven fabric was too large, the impregnation property of the resin composition was poor, the moisture absorption solder heat resistance was poor, and the laser processability and the through-hole insulation reliability were also poor.
In Comparative Example 6, since the bulk density of the fiber woven fabric was small, the laser processability and the through-hole insulation reliability were poor. Furthermore, since the bulk density of the fiber woven fabric is small, it becomes a thick fiber base material, so that the thickness of the resin layer on the surface layer of the prepreg becomes thin. For this reason, it was inferior to a moldability and moisture absorption solder heat resistance, and PKG curvature occurred.

This application claims priority based on Japanese Patent Application No. 2011-012166 filed on January 24, 2011, the entire disclosure of which is incorporated herein.

Claims

A prepreg obtained by impregnating a fiber woven fabric composed of strands with a resin composition, and silica particles are present in the strands.
The prepreg according to claim 1,
A prepreg in which no void having a length of 50 μm or more exists in the strand in the direction in which the fibers constituting the strand extend.
The prepreg according to claim 1 or 2,
A prepreg in which the number density of voids having a diameter of 50 μm or more in the strand is 50 cm −1 or less.
The prepreg according to any one of claims 1 to 3,
A prepreg having a bulk density of the fiber woven fabric of 1.05 to 1.30 g / cm 3 .
The prepreg according to any one of claims 1 to 4,
A prepreg having an average particle diameter of 5 to 100 nm of the silica particles present in the strand.
The prepreg according to any one of claims 1 to 5,
The resin composition includes at least a thermosetting resin and a filler,
The filler is a prepreg that is contained in a proportion of 50 to 85% by mass with respect to the solid content of the resin composition.
The prepreg according to claim 6,
The filler is a prepreg containing the silica particles in a proportion of 1 to 20% by mass with respect to the filler.
The prepreg according to any one of claims 1 to 7,
A prepreg having an overall thickness of 30 to 220 μm.
The prepreg according to any one of claims 1 to 8,
The strand is a prepreg composed of glass fibers containing at least 50 to 100% by mass of SiO 2 , 0 to 30% by mass of Al 2 O 3 and 0 to 30% by mass of CaO.
The prepreg according to claim 9, wherein
The glass fiber is a prepreg made of at least one glass selected from the group consisting of T glass, S glass, D glass, E glass, NE glass, and quartz glass.
The prepreg according to claim 9 or 10,
The glass fiber is a prepreg having a Young's modulus of 50 to 100 GPa when formed into a plate, a tensile strength of 25 GPa or more when formed into a plate, and a tensile strength of 30 N / 25 mm or more when formed into a fiber woven fabric. .
The prepreg according to any one of claims 9 to 11,
A prepreg in which the fiber woven fabric has an air permeability of 1 to 80 cc / cm 2 / sec.
The prepreg according to any one of claims 1 to 12,
The silica particles are prepregs that are surface-treated with functional group-containing silanes or alkylsilazanes.
A laminate obtained by curing the prepreg according to any one of claims 1 to 13.
The laminate according to claim 14, wherein
A laminate in which a conductor layer is provided on at least one outer surface of the prepreg.
A printed wiring board using the prepreg according to any one of claims 1 to 13 or the laminated board according to claim 14 or 15 as an inner circuit board.
The printed wiring board according to claim 16, wherein
A printed wiring board, wherein the prepreg according to any one of claims 1 to 13 is provided as an insulating layer on the inner layer circuit board.
A semiconductor device in which a semiconductor element is mounted on the printed wiring board according to claim 16 or 17.