JP2015228390A - Method for manufacturing substrate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for manufacturing a substrate superior in low thermal expandability, by which the settling of a filler can be suppressed.SOLUTION: A method for manufacturing a substrate comprises the steps of: forming, on one or each of opposing faces of glass cloth 1, a resin composition layer 2 made of a thermosetting resin composition including 70-92 mass% of filler thereby preparing a prepreg 3; and vacuum-compression molding the prepreg or a laminate of more than one prepreg thus prepared. The proportion (V1:V2) of a total volume (V1) of the glass cloth and the filler in the resin composition layer to a volume (V2) of a resin in the resin composition is 75:25 to 90:10. The resin composition layer has a softening point of 40-120°C, a thickness of 20-200 μm and a melt viscosity of 200 Pa s or less.

Description

  The present invention relates to a method for manufacturing a substrate.

In recent years, with the reduction in size, weight and functionality of electrical and electronic devices, multilayer printed wiring boards used in such devices are increasingly required to be thinner and higher in density.
A substrate used for a multilayer printed wiring board is impregnated with a varnish obtained by diluting a thermosetting resin composition with a solvent or the like in a base material such as glass cloth, and then is made into a B stage by drying and heating. The prepreg obtained in this way can be produced by press molding at high temperature and pressure.

Since the substrate obtained by the above method contains a resin component having a high coefficient of thermal expansion, when a printed wiring board and a silicon chip are flip-chip mounted, stress is generated due to the difference in coefficient of thermal expansion between these and the connection. The problem of insufficient reliability arises.
In order to reduce the thermal expansion coefficient of printed wiring boards, ceramic substrates and metal substrates with low thermal expansion coefficient have been proposed. However, because of problems in workability and cost, glass cloth and thermosetting resin composition are used. It is desired to provide a performance close to that of ceramic by highly filling an inorganic filler in a general-purpose prepreg.
In addition, the high filling of the inorganic filler is effective not only for low thermal expansion, but also for preventing warpage of the substrate, suppressing water absorption, and improving the rigidity and thermal conductivity of the substrate. Is an important technology.

The filler can be filled in the prepreg by dispersing the filler in the thermosetting resin composition impregnated in the glass cloth.
For example, Patent Document 1 discloses a resin-impregnated sheet having a thickness of 200 to 500 μm in which a nonwoven fabric is impregnated with a resin composition containing 70 to 95% by mass of a filler to form a B stage, and the resin content is 90% by mass. The resin-impregnated sheet is disclosed in which the nonwoven fabric is formed of fibers having a diameter of 10 μm or less and a length of 13 mm or more.

JP 2011-111508 A

When the filler is highly filled, sedimentation of the filler and an increase in the viscosity of the varnish occur, and the base material may not be uniformly impregnated with the thermosetting resin composition. Although patent document 1 is aiming at high filling of a filler by using a specific nonwoven fabric, said problem has not yet been solved.
In addition, as a method for highly filling the filler, a method for adjusting the particle size distribution of the spherical silica, a method for improving the affinity between the silica and the resin component by modifying the surface of the silica with a coupling agent, etc. Although studies have been made, a sufficient thermal expansion coefficient reduction effect has not been obtained.
An object of this invention is to provide the manufacturing method of the board | substrate which suppresses sedimentation of a filler and is excellent in low thermal expansibility.

  As a result of intensive studies to achieve the above object, the inventors of the present invention have formed a prepreg obtained by forming a resin composition layer containing a specific amount of filler on the surface of a glass cloth, and then subjecting the substrate to vacuum pressure molding It has been found that the above manufacturing method can solve the above problems, and the present invention has been completed.

That is, the present invention provides the following method for manufacturing a substrate.
[1] A resin composition layer composed of a thermosetting resin composition containing 70 to 92% by mass of filler is formed on one or both surfaces of a glass cloth to form a prepreg, and the prepreg is singly or laminated. A method of manufacturing a substrate, which is vacuum-pressure molded.
[2] The ratio (V1: V2) of the total volume (V1) of the glass cloth and the filler in the resin composition layer to the volume (V2) of the resin in the resin composition is 75:25 The method for producing a substrate according to the above [1], which is 90:10.
[3] The substrate according to [1] or [2] above, wherein the resin composition layer has a softening point of 50 to 120 ° C., a thickness of 20 to 200 μm, and a melt viscosity during vacuum forming of 200 Pa · s or less. Production method.
[4] The method for producing a substrate according to any one of [1] to [3], wherein the glass cloth is a plain weave glass cloth, the filament diameter is 5 to 13 μm, and the thickness is 15 to 110 μm.
[5] The thermosetting resin composition is one or more selected from (A) a biphenyl type epoxy resin, (B) a bisphenol type liquid epoxy resin, and (C) a solid epoxy resin having a softening point of 120 ° C. or lower. D) The manufacturing method of the board | substrate in any one of said [1]-[4] containing the hardening | curing agent for epoxy resins, (E) hardening accelerator, and (F) inorganic filler.
[6] The resin composition layer is formed by stacking and integrating a resin sheet made of a thermosetting resin composition containing 70 to 92% by mass of the filler on one side or both sides of the glass cloth. [1] The method for producing a substrate according to any one of [5].

  ADVANTAGE OF THE INVENTION According to this invention, the sedimentation of a filler can be suppressed and the manufacturing method of the board | substrate excellent in low thermal expansion property can be provided.

It is a schematic diagram which shows the procedure which laminates a thermosetting resin composition on glass cloth. It is a schematic diagram which shows the cross section of the prepreg used for the manufacturing method of (a) this invention, and the laminated board obtained by vacuum-press-molding (b) prepreg. It is a schematic diagram which shows the cross section of the laminated board obtained by vacuum-pressure-molding (a) prepreg (3 sheets) used for the manufacturing method of this invention, and (b) prepreg (3 sheets).

Hereinafter, the present invention will be described in detail.
In the production method of the present invention, a resin composition layer comprising a thermosetting resin composition containing 70 to 92% by mass of a filler is formed on one or both surfaces of a glass cloth to form a prepreg, and the prepreg is used alone or This is a method for manufacturing a substrate, in which a plurality of sheets are stacked and vacuum-pressure formed.

The reason why the production method of the present invention can provide a substrate that suppresses the sedimentation of the filler and is excellent in low thermal expansion is considered as follows.
In the manufacturing method of this invention, the resin composition layer which consists of a thermosetting resin composition containing 70-92 mass% of fillers is formed in the single side | surface or both surfaces of a glass cloth, and it is set as a prepreg. The resin in the resin composition layer does not impregnate the glass cloth.
Next, the substrate is obtained by vacuum-pressing the prepreg alone or by stacking a plurality of prepregs. By pressing the prepreg at high temperature and high pressure under vacuum, the resin in the thermosetting resin composition bleeds from between the fillers and penetrates into the glass cloth. By this operation, the resin existing between the fillers is sucked into the glass cloth, so that it is considered that the filler is filled to such an extent that the fillers come into contact with each other. According to this method, by adjusting the thickness of the glass cloth and the thickness of the resin composition layer, it is considered that the filler can be highly filled to the extent that the glass cloth, the filler, and the fillers are almost in contact with each other.

[Thermosetting resin composition]
The thermosetting resin composition used in the production method of the present invention contains 70 to 92% by mass of filler.

<Thermosetting resin composition>
It does not specifically limit as a thermosetting resin contained in a thermosetting resin composition, A well-known thermosetting resin generally used for prepregs, such as an epoxy resin, a phenol resin, a cyanate resin, can be used. Among these, an epoxy resin is preferable from the viewpoints of insulation, heat resistance, versatility, and high filler filling.

(Epoxy resin)
Although it does not specifically limit as an epoxy resin, The glycidyl ether type epoxy resin which has two or more epoxy groups in 1 molecule is used suitably, for example, biphenyl type epoxy resin; dicyclopentadiene type epoxy resin; phenol novolak type Epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, bisphenol F novolac type epoxy resins, bisphenol S novolac type epoxy resins and other novolac type epoxy resins; bisphenol F type liquid epoxy resins, bisphenol A type liquid epoxy resins, etc. And bisphenol type liquid epoxy resin.
Among these, one or more selected from (A) biphenyl type epoxy resin, (B) bisphenol type liquid epoxy resin, and (C) solid epoxy resin having a softening point of 120 ° C. or lower is more preferable, and (A) biphenyl type. Epoxy resins are more preferred, and biphenyl type epoxy resins having a softening point of 120 ° C. or lower are even more preferred.
In addition, the epoxy resin preferably has a low viscosity to such an extent that it can be liquefied by heating to disperse the filler from the viewpoint of increasing the filler content. From the same viewpoint, the melting point of the epoxy resin liquefied by heating is preferably 40 to 120 ° C, more preferably 50 to 120 ° C, and still more preferably 65 to 120 ° C.
In addition, an epoxy resin can be used individually or in combination of 2 or more types.

(Curing agent)
The curing agent contained in the thermosetting resin composition can be appropriately selected according to the type of the thermosetting resin.
When an epoxy resin is used as the thermosetting resin, a known (D) epoxy resin curing agent such as an amine curing agent, a phenol curing agent, or a phosphorus curing agent can be used as the curing agent. From the viewpoint of reactivity with the resin, cured product characteristics, and high filler filling, phenolic curing agents are preferred.
The phenol-based curing agent is not particularly limited as long as it has two or more phenolic hydroxyl groups in the molecule; novolak-type phenol resins such as phenol novolak resin and cresol novolak resin; phenol aralkyl resin, biphenyl aralkyl resin and the like Aralkyl-type phenol resins; polyfunctional aromatic phenol resins, and modified resins thereof. Among these, an aralkyl type phenol resin is preferable and a phenol aralkyl resin is more preferable from the viewpoint of reactivity with an epoxy resin, cured product characteristics, and high filler filling.
The softening point of the phenol resin is preferably 40 to 120 ° C, more preferably 50 to 120 ° C, and still more preferably 65 to 120 ° C, from the viewpoint of highly filling the filler.
In addition, a hardening | curing agent can be used individually or in combination of 2 or more types.

  The ratio of the hydroxyl equivalent of the phenolic curing agent to the epoxy equivalent of the epoxy resin (hydroxyl equivalent / epoxy equivalent) is preferably 0.5 to 1.5, and preferably 0.7 to 1.5 from the viewpoint of reactivity and cured product characteristics. 1.3 is more preferable, and 0.8 to 1.2 is still more preferable.

  The total content of the thermosetting resin and the curing agent in the thermosetting resin composition is preferably 6 to 25% by mass from the viewpoint of achieving both low thermal expansion and reliability of the obtained printed wiring board. 8-20 mass% is more preferable, and 10-16 mass% is still more preferable.

((E) Curing accelerator)
From the viewpoint of adjusting the curing rate, the thermosetting resin composition preferably contains (E) a curing accelerator. A hardening accelerator can be suitably selected according to the kind of resin.
When using an epoxy resin as a thermosetting resin, a known curing accelerator such as an imidazole curing accelerator, an organic phosphorus curing accelerator, an amine curing accelerator, a thiol curing accelerator, and the like can be used. From the viewpoints of reactivity and cured product characteristics, imidazole-based curing accelerators are preferred. Examples of the imidazole curing accelerator include imidazole, 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, and the like. (E) A hardening accelerator can be used individually or in combination of 2 or more types.
(E) The usage-amount of a hardening accelerator should just be determined suitably according to the kind of hardening accelerator and thermosetting resin. In the case of using an epoxy resin as the thermosetting resin and a phenolic curing agent as the curing agent, from the viewpoint of reactivity and cured product characteristics, the amount of the epoxy resin and the phenolic curing agent is 0.1 parts by mass with respect to 100 parts by mass. 1-5.0 mass parts is preferable, 0.5-3.0 mass parts is more preferable, and 1.0-2.0 mass parts is still more preferable.

((F) filler)
As the filler (F), known inorganic fillers such as silica, alumina, zirconia and boron nitride, and known flame retardants such as aluminum hydroxide and magnesium hydroxide can be used depending on the application. Among these, silica is preferable from the viewpoint of versatility and filling properties. (F) The shape of the filler may be spherical, scaly, or indefinite, and spherical is preferred from the viewpoint of filling properties. The aspect ratio of the spherical silica is preferably 1.0 to 1.2, more preferably 1.0 to 1.1, and still more preferably 1.0 to 1.05.
The average particle diameter of the spherical filler is preferably 0.5 to 15 μm, more preferably 1 to 10 μm, and further preferably 3 to 7 μm, from the viewpoint of filling properties. Moreover, it is preferable that a spherical filler is used, adjusting a particle size distribution suitably from the same viewpoint. (F) A filler can be used individually or in combination of 2 or more types.
The content of the filler (F) in the thermosetting resin composition is 70 to 92% by mass and 76 to 90% by mass from the viewpoint of achieving both low thermal expansion and reliability of the obtained printed wiring board. Preferably, 82-88 mass% is more preferable.

(Silane coupling agent)
The thermosetting resin composition preferably contains a silane coupling agent from the viewpoint of improving the dispersibility of the filler.
Silane coupling includes aminosilane coupling agents such as γ-aminopropyltrimethoxysilane, epoxy silane coupling agents such as γ-glycidoxypropyltrimethoxysilane, and mercaptosilane coupling agents such as γ-mercaptopropyltrimethoxysilane. From the viewpoint of improving the dispersibility of the filler, an epoxy silane coupling agent is preferable. A silane coupling agent can be used individually or in combination of 2 or more types.
From the viewpoint of improving the dispersibility of the filler, the amount of the silane coupling agent is preferably 0.01 to 5 parts by mass, more preferably 0.1 to 3 parts by mass with respect to 100 parts by mass of the filler. 3 to 1 part by mass is more preferable.

  In the thermosetting resin composition in the present invention, in addition to the above components, flame retardants such as metal hydroxide and zinc borate, antifoaming agents, leveling agents, etc., as long as the effects of the present invention are not impaired. These commonly used additives can be blended as needed.

Among the above embodiments, the thermosetting resin composition is one or more selected from (A) a biphenyl type epoxy resin, (B) a bisphenol type liquid epoxy resin, and (C) a solid epoxy resin having a softening point of 120 ° C. or lower. , (D) a curing agent for epoxy resin, (E) a curing accelerator, and (F) an inorganic filler are preferably contained.
The total amount of the components (A) to (F) in the thermosetting resin composition is preferably 80 to 100% by mass, more preferably 90 to 100% by mass, and 95 to 100 from the viewpoint of increasing the filler filling. More preferred is mass%.

(Method for producing thermosetting resin composition)
The thermosetting resin composition is obtained by mixing the above-described components. As the mixing device, a known mixer such as a roll or a mixer can be used. Although the temperature at the time of mixing can be suitably determined according to the kind etc. of resin etc., it is more than the melting temperature of a thermosetting resin. Usually, 80-160 degreeC is preferable and 100-140 degreeC is more preferable.

[Prepreg]
Next, a resin composition layer made of the thermosetting resin composition is formed on one side or both sides of the glass cloth to prepare a prepreg.

<Glass cloth>
The glass cloth is not particularly limited, but a plain weave glass cloth that is widely used for printed wiring board applications is preferable. Glass cloth is made by weaving twisted yarns, which are a combination of many fine filaments, as warp yarns and weft yarns.
The filament diameter of the glass cloth is preferably 5 to 13 μm, more preferably 5 to 10 μm, and still more preferably 5 to 8 μm, from the viewpoint of increasing the permeability of the resin. In the present invention, the filament diameter means an average filament diameter, and is an arithmetic average value of values obtained by taking out 50 arbitrary filaments in a glass cloth and measuring an arbitrary position with an optical microscope or an electron microscope. .
The thickness of the glass cloth is preferably 15 to 110 μm, more preferably 25 to 80 μm, and still more preferably 35 to 50 μm from the same viewpoint.
The material of the glass cloth can be appropriately selected according to the application. From the viewpoint of cost reduction, E glass is preferable, and from the viewpoint of low thermal expansion, the thermal expansion of the glass itself such as S glass and T glass. A thing with a small coefficient is preferable.

<Formation of resin composition layer>
Examples of the method for forming the resin composition layer on the glass cloth (hereinafter, also referred to as “laminate step (1)”) include the following methods.
First, the thermosetting resin composition is heated so as to have a viscosity that can be stretched thinly. Although heating temperature is based also on the kind of resin, it is 50-120 degreeC normally, and 60-120 degreeC is preferable from a viewpoint of improving the homogeneity of a thermosetting resin composition, and 70-120 degreeC is more preferable.
Next, the thermosetting resin composition heated and melted is put between the release film and the glass cloth, and these are passed through a roll having a certain clearance, so that the resin composition layer is uniformly formed on the surface of the glass cloth. Form. When the resin composition layer is formed on one side of the glass cloth by this process, when three layers of [release film / resin composition layer / glass cloth] and the resin composition layer are formed on both sides of the glass cloth, A prepreg with a release film composed of 5 layers of [release film / resin composition layer / glass cloth / resin composition layer / release film] can be obtained.
The roll is preferably a hot roll, and the roll temperature is usually from 50 to 120 ° C., although depending on the type of resin, from the viewpoint of productivity and uniform formation of the resin composition layer on the glass cloth surface. 60-120 degreeC is preferable and 70-120 degreeC is more preferable.
From the same viewpoint, the rotational speed of the roll is preferably 0.1 to 2.0 m / min, more preferably 0.5 to 1.5 m / min, and still more preferably 0.8 to 1.2 m / min.
It does not specifically limit as a release film, A well-known release film, such as PET (polyethylene terephthalate), PE (polyethylene), PP (polypropylene) film, can be used.

The resin composition layer may be formed by a method of stacking and integrating a glass cloth and a resin sheet made of a thermosetting resin composition (hereinafter also referred to as “lamination step (2)”). .
In the laminating step (2), similarly to the laminating step (1), the thermosetting resin composition is heated so as to have a viscosity that can be stretched thinly. The heating temperature is the same as in the laminating step (1), and the preferred embodiment is also the same.
Next, the thermosetting resin composition heated and melted is put between two release films, and these are passed through a roll having a certain clearance, so that [release film / resin composition layer / release] A resin sheet with a release film composed of three layers of film is prepared.
The release film on one side of the resin sheet with the release film obtained above is peeled off, and the resin sheet is stacked on one side or both sides of the glass cloth so that the resin sheet and the glass cloth come into contact with each other. The resin composition layer is uniformly formed on the surface of the glass cloth by press forming. When the resin composition layer is formed on one side of the glass cloth by this process, when three layers of [release film / resin composition layer / glass cloth] and the resin composition layer are formed on both sides of the glass cloth, A prepreg with a release film composed of 5 layers of [release film / resin composition layer / glass cloth / resin composition layer / release film] can be obtained.

In the present invention, the prepreg means that the glass cloth is coated with a resin and the resin is in a solid state with no tack at 25 ° C.
The softening point of the resin composition layer is preferably 40 to 120 ° C, more preferably 45 to 120 ° C, and still more preferably 48 to 120 ° C, from the viewpoint of increasing the filler filling.
Moreover, 20-200 micrometers is preferable from a viewpoint of the high filling of a filler, and, as for the thickness of a resin composition layer, 40-180 micrometers is more preferable, and 45-80 micrometers is still more preferable.
Further, from the same viewpoint, the melt viscosity of the resin composition layer is preferably 200 Pa · s or less, more preferably 100 Pa · s or less, and further preferably 50 Pa · s or less. In the present specification, the melt viscosity of the resin composition layer means the melt viscosity at 100 ° C.
The softening point and melt viscosity of the resin composition layer are values measured by the methods described in the examples.

  The mass ratio of the glass cloth and the thermosetting resin composition in the prepreg obtained above is preferably 15/85 to 50/50, and preferably 20/80 to 45/55, from the viewpoint of increasing the filler filling. More preferred is 25/75 to 40/60.

[Vacuum pressure molding]
Next, the board | substrate of this invention can be manufactured by carrying out the vacuum press molding of the prepreg obtained above individually or by laminating several sheets.
When the prepreg is used alone, as shown in FIG. 2, it is preferable to form the resin composition layers 2 having the same thickness on both surfaces of the glass cloth 1 so that the front and back of the prepreg are symmetric.
Further, when a plurality of prepregs are laminated, it is preferable to combine them so that the positions of the resin composition layer 2 and the glass cloth 1 are symmetrical as shown in FIG.
When using a prepreg in which the resin composition layer is formed only on one side of the glass cloth, it is preferable to combine so that the resin composition layer exists in the outermost layer and combine so that the resin composition layer exists between the glass cloths. .
Conductor such as copper foil is placed on both sides of the prepreg combined as described above, and sandwiched between mirror plates such as stainless steel and heated above the melting temperature of the resin, so that the glass cloth is impregnated with resin and at the same time above the curing temperature The substrate is integrated with the copper foil by thermosetting the resin.

Vacuum pressure molding is generally used for laminated plate molding, and can be performed using a pressure heating press capable of vacuum molding.
The degree of vacuum during pressing is preferably 1 to 50 kPa, more preferably 3 to 20 kPa, and still more preferably 5 to 10 kPa, from the viewpoint of increasing the permeability of the resin to the glass cloth.
From the same viewpoint, the pressing temperature is preferably 150 to 210 ° C, more preferably 160 to 200 ° C, and still more preferably 170 to 190 ° C.
From the same viewpoint, the pressurizing condition at the time of pressing is preferably 1 to 6 MPa, more preferably 2 to 5 MPa, and further preferably 3 to 4 MPa.
Further, from the same viewpoint, the pressing time is preferably 30 to 150 minutes, more preferably 50 to 130 minutes, and still more preferably 70 to 110 minutes.

  The total volume (V1) of the glass cloth in the substrate obtained by the production method of the present invention and the filler in the resin composition layer (hereinafter also referred to as “volume of inorganic component (V1)”), and the resin composition The ratio (V1: V2) to the resin volume (V2) (hereinafter also referred to as “organic component volume (V2)”) is 70/30 from the viewpoint of achieving both low thermal expansion and reliability of the printed wiring board. -95/5 is preferable, 75 / 25-90 / 10 is more preferable, and 80 / 20-85 / 15 is still more preferable.

  The substrate obtained above is a substrate reinforced with glass cloth, and can be further reduced in thermal expansion or increased in thermal conductivity depending on the type of filler.

  As mentioned above, although embodiment was described, these embodiment was shown as an example and is not intending limiting the range of invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention.

Next, although an example and a comparative example explain the present invention, the present invention is not limited by these examples. The resin composition and the substrate were evaluated under the following measurement conditions.
(1) Presence / absence of sedimentation Presence / absence of sedimentation was confirmed visually after standing at 40 ° C. for 24 hours.
(2) Coefficient of thermal expansion Each coefficient of thermal expansion in the surface direction (XY) and the thickness direction (Z) of the substrates obtained in the examples and comparative examples was measured using a thermomechanical analyzer [manufactured by Seiko Instruments Inc., Product name: TMA / SS6000] and measured in the range of 25 to 280 ° C. under a nitrogen atmosphere under a temperature increase condition of a load of 5 mN and 10 ° C./min by a TMA method.
(3) Softening point The softening point of the resin composition layer is a value measured according to JIS K-7121.
(4) Melt viscosity The melt viscosity of the resin composition layer is a value measured with a rheometer [trade name: AEES-G2, manufactured by TA Instruments Japan Co., Ltd.].

Example 1
Step (1) Preparation of resin composition 5 parts by mass of biphenyl type epoxy resin [Mitsubishi Chemical Corporation, trade name: YX4000, epoxy equivalent: 193], phenol aralkyl resin [Mitsui Chemicals, trade name: XL325M ] 4 parts by mass, 2-heptadecylimidazole [manufactured by Tokyo Chemical Industry Co., Ltd.] 0.15 parts by mass, spherical silica [manufactured by Tatsumori Co., Ltd., trade name: EUF-46V, average particle size: 5 μm] 53 parts by mass Part, epoxy silane [manufactured by Shin-Etsu Chemical Co., Ltd., trade name: KBM-402] 0.4 parts by mass, kneaded at 120 ° C. using a hot roll, filler content 84.7% by mass. A resin composition was obtained.

Step (2) Preparation of prepreg Glass cloth [manufactured by Nittobo Co., Ltd., trade name: IPC spec: 1080 type] and release film [manufactured by Toray Industries, Inc., trade name: R75, thickness: 38 μm, material: PET Are placed between two metal rolls in the order of [release film / glass cloth / release film], and the glass cloth and release film are sent by rotating the metal roll.
Next, the metal roll was heated to 80 ° C., and as shown in FIG. 1, a thermosetting resin composition heated and melted at 80 ° C. between the glass cloth and the release film was supplied. The metal roll is rotated at 1 m / min, rolled to a certain thickness in a state where the thermosetting resin composition is sandwiched between the glass cloth and the release film, and then cooled to [release film / resin composition] A prepreg with a release film composed of 5 layers of physical layer / glass cloth / resin composition layer / release film] was produced.
The softening point of the resin composition layer was 50 ° C., and the melt viscosity at 100 ° C. was 50 Pa · s.
By releasing the release films on both sides, a prepreg having a mass ratio of 68.5% by mass of the resin composition and an apparent thickness of 90 μm, in which the resin composition layer was laminated on both sides of the glass cloth, was obtained.

Step (3) Production of Substrate Sixteen prepregs produced in the above (2) are stacked, and in order to measure physical properties, a release film is arranged on both sides, and a stainless steel plate and a material sandwiched between cushion materials are vacuum degrees. A vacuum heating press was performed for 90 minutes under conditions of 5 kPa, a temperature of 180 ° C., and a pressure of 3.5 MPa to produce a substrate having a thickness of 1.1 mm. Table 1 shows the physical properties of the obtained substrate.

Example 2
A 0.07 mm substrate was produced in the same manner as in Example 1 except that the number of prepregs was changed from 16 to 1 in the step (3) of Example 1. Table 1 shows the physical properties of the obtained substrate.

Example 3
Except for changing the blending amount of the spherical silica from 53 parts by mass to 60 parts by mass and changing the filler content in the resin composition to 86.3% by mass in the step (1) of Example 1, Similarly, a substrate was produced. The softening point of the resin composition layer was 52 ° C., and the melt viscosity at 100 ° C. was 150 Pa · s. Table 1 shows the physical properties of the obtained substrate.

Example 4
In the step (2) of Example 1, the amount of the resin composition was adjusted so that the mass ratio of the glass cloth and the resin composition in the prepreg was 37:63 to obtain a prepreg having an apparent thickness of 80 μm. A substrate was prepared in the same manner as in Example 1 except that the number of prepregs was changed from 16 to 18 in the step (3). Table 1 shows the physical properties of the obtained substrate.

Comparative Example 1
A thermosetting resin composition obtained by the same procedure as in step (1) of Example 1 was diluted with methyl ethyl ketone to prepare a varnish having a solid content concentration of 70% by mass.
The glass cloth used in Example 1 was impregnated with this varnish and dried at 150 ° C. for 3 minutes to prepare a prepreg having a resin composition mass ratio of 75 mass% and an apparent thickness of 80 μm.
Eighteen prepregs obtained as described above were stacked and subjected to vacuum heating press under the same conditions as in step (3) of Example 1 to prepare a substrate. Table 1 shows the physical properties of the obtained substrate.

Comparative Example 2
A substrate was produced in the same manner as in Comparative Example 1 except that the composition of the resin composition in Comparative Example 1 was changed to the composition shown in Table 1. Table 1 shows the physical properties of the obtained substrate.

  From Table 1, it can be seen that the substrate obtained by the production method of the present invention has no sedimentation of filler and is excellent in low thermal expansion.

DESCRIPTION OF SYMBOLS 1 Glass cloth 2 Resin composition layer 3 Prepreg 4 Laminated board

Claims (6)

  A resin composition layer composed of a thermosetting resin composition containing 70 to 92% by mass of filler is formed on one or both surfaces of a glass cloth to form a prepreg, and the prepreg is singly or laminated in a vacuum. A method of manufacturing a substrate by pressure molding.   The ratio (V1: V2) of the total volume (V1) of the glass cloth and the filler in the resin composition layer to the volume (V2) of the resin in the resin composition is 75:25 to 90:10. The method for manufacturing a substrate according to claim 1, wherein   The manufacturing method of the board | substrate of Claim 1 or 2 whose softening point of the said resin composition layer is 40-120 degreeC, thickness is 20-200 micrometers, and melt viscosity is 200 Pa.s or less.   The method for manufacturing a substrate according to any one of claims 1 to 3, wherein the glass cloth is a plain weave glass cloth having a filament diameter of 5 to 13 µm and a thickness of 15 to 110 µm.   The thermosetting resin composition is at least one selected from (A) a biphenyl type epoxy resin, (B) a bisphenol type liquid epoxy resin, (C) a solid epoxy resin having a softening point of 120 ° C. or lower, and (D) an epoxy. The manufacturing method of the board | substrate of any one of Claims 1-4 containing the hardening | curing agent for resins, (E) hardening accelerator, and (F) inorganic filler.   The resin composition layer is formed by stacking and integrating a resin sheet made of a thermosetting resin composition containing 70 to 92% by mass of the filler on one or both surfaces of the glass cloth. 6. The method for producing a substrate according to any one of 5 above.