JP2006152260A - Composite, prepreg, metal foil-clad laminated plate and multilayer printed wiring board obtained using the same, and manufacturing method of multilayer printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite which is sufficiently excellent in adhesion reliability and is sufficiently suppressed in generation of resin powders or fibers liable to fall off. <P>SOLUTION: The composite 100 is obtained by impregnating a fiber sheet 101 with a curable resin composition 102, where the storage elastic modulus at 20°C of a cured product of the curable resin composition is 100-2,000 MPa. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a composite, a prepreg using the composite, a metal foil-clad laminate, a multilayer printed wiring board, and a method for producing a multilayer printed wiring board.

  In recent years, as electronic devices have become smaller, thinner, lighter, and more functional, multilayer printed wiring boards that enable high-density mounting of electronic components are widely used. The multilayer printed wiring board has an advantage that the substrate surface area can be reduced because the wiring pattern is formed in a plurality of layers. Recently, multilayer printed wiring boards having an inner via hole (IVH) structure have been developed aiming at higher density mounting (see, for example, Patent Document 1).

  In a multilayer printed wiring board having an IVH structure, via holes (through holes) are provided in the insulating substrate of each layer, and the wiring pattern of each layer is electrically connected by filling the via hole with a conductor. Can do. Unlike the through holes, the via holes need not have all the holes in each layer on a straight line, so that the degree of freedom of wiring is improved. As a result, the multilayer printed wiring board having the IVH structure can be further reduced in size.

JP-A-6-268345

  However, a conventional multilayer printed wiring board having an IVH structure may not have sufficient reliability because dents may be generated on the wiring board during the production or the wiring may be disconnected. There was a thing. In particular, when the thickness of each layer is reduced in order to increase the density, the above-described defects tend to occur frequently.

  Thus, as a result of examining the cause of the defect in detail, the present inventors have found that the resin powder or fiber that falls off from the resin-impregnated sheet used as the insulating substrate is a major cause of the defect. Further, it has been found that a large amount of resin powder or fiber that drops off is generated particularly when an insulating substrate having a via hole is formed.

  In addition, even if you select the material that only considers the resin powder or fiber dropout as the material of the insulating substrate, if you do not have sufficient adhesion reliability required for the insulating substrate used in the multilayer printed wiring board, As a result, a multilayer printed wiring board having sufficient reliability cannot be obtained.

  An object of the present invention is to solve the above-mentioned problems, and to provide a composite that is sufficiently excellent in adhesion reliability and sufficiently suppressed from generating resin powder or fibers that may drop off. . Another object of the present invention is to provide a prepreg and a metal foil-clad laminate using such a composite. Furthermore, another object of the present invention is to provide a multilayer printed wiring board capable of increasing the density of component mounting and having sufficiently excellent reliability, and a method for manufacturing such a multilayer printed wiring board.

  In order to achieve the above object, the composite of the present invention is a composite comprising a fiber sheet impregnated with a curable resin composition, and the cured product of the curable resin composition has a storage elastic modulus at 20 ° C. 100 to 2000 MPa.

  In the present invention, the “storage elastic modulus at 20 ° C. of the cured product of the curable resin composition” means a value obtained by the following procedure. First, a varnish containing a curable resin composition is applied to an electrolytic copper foil (made by Furukawa Electric Co., Ltd., trade name “F2-WS-12”) having a thickness of 12 μm so that the coating thickness is about 50 to 100 μm. And heated at 180 ° C. for 60 minutes. Next, the cured resin obtained by removing the copper foil by etching is cut out to about 30 mm × 5 mm, and this is used as a sample for measuring storage elastic modulus. About this measurement sample, a dynamic viscoelasticity curve is obtained by measuring using a dynamic viscoelasticity measuring device “Reogel-E-4000” (manufactured by UBM) under conditions of a measurement length of 20 mm and a measurement frequency of 10 Hz. And let the elastic modulus in 20 degreeC of the obtained dynamic viscoelastic curve be "the storage elastic modulus in 20 degreeC of the hardened | cured material of a curable resin composition."

  In the composite of the present invention, the fiber sheet is impregnated with a curable resin composition in which the storage modulus of the cured product falls within the above range, thereby sufficiently suppressing the occurrence of resin powder or fibers that may fall off. In addition, the adhesive reliability is sufficiently excellent. Therefore, by using the composite of the present invention as a material for an insulating substrate, a multilayer printed wiring board having excellent reliability can be manufactured.

  When the storage elastic modulus at 20 ° C. of the cured product of the curable resin composition is less than 100 MPa, handleability and dimensional stability are deteriorated, and sufficient adhesion reliability cannot be obtained. If it exceeds, the cured resin becomes brittle, and thus generation of resin powder or fibers that may fall off cannot be sufficiently suppressed.

  In the composite of the present invention, the ratio Va / Vb of the volume Va of the curable resin composition to the volume Vb of the fiber sheet is preferably 0.3 to 0.9.

  When the above Va / Vb is less than 0.3, the resin component is insufficient when integrated with the conductor layer, and when integrated at high speed, bubbles or blurring may occur, or the surface of the integrated conductor layer The unevenness of the fiber sheet is reflected on the surface and the surface smoothness tends to decrease. Thereby, it tends to be difficult to obtain sufficient adhesion reliability. On the other hand, when Va / Vb exceeds 0.9, there is a tendency that the dimensional stability such as distortion occurs in the base material in a heat resistance test such as leaving at high temperature.

  Furthermore, in the composite of the present invention, the curable resin composition preferably contains a viscoelastic resin. Such a composite is more reliably suppressed from generating resin powder or fibers that may fall off, and has sufficiently excellent adhesion reliability.

  Further, in the composite of the present invention, the curable resin composition contains an acrylic polymer having a weight average molecular weight of 30000 or more, and the acrylic polymer contains 2 to 20% by mass of glycidyl acrylate as a polymerization component, The epoxy value is preferably 2 to 36.

In the present invention, the weight average molecular weight of the acrylic polymer means a value measured by gel permeation chromatography (GPC) under the following conditions and converted using a standard polystyrene calibration curve.
(GPC conditions)
Detector: HLC-8120GPC [manufactured by Tosoh Corporation]
Column: GMH _XL equivalent product (3) (manufactured by TOSOH, trade name “TSKgel G5000H”)
Column size: 7.5mmφ × 300mm
Eluent: THF
Sample concentration: 5 mg / 1 mL
Injection volume: 50 μL
Pressure: 50 kgf / cm ²
Flow rate: 1.0 mL / min

In the present invention, the epoxy value of an acrylic polymer containing glycidyl acrylate as a polymerization component means a value determined by the following procedure.
1) Weigh accurately 2.5 g of sample (acrylic polymer) in a 100 ml Erlenmeyer flask with a stopper.
2) Add about 20 ml of methyl ethyl ketone (MEK) and stir and dissolve the sample for about 5 minutes.
3) Add 10 ml of N / 10HCl dioxane solution with a whole pipette, stopper and shake lightly to confirm that it is clear and uniform, and leave it for 10 minutes.
4) Add about 4 ml of ethanol, add 5 drops of phenolphthalein indicator, and titrate with 1/10 KOH ethanol solution. The end point is the time when it is colored light pink.
5) Separately, titrate a blank containing no sample in the same manner (blank test).
6) The epoxy value is calculated by the following formula.
Epoxy value (eq / 100 g) = (f × (BT)) / (W × c)
In the above formula, f represents the factor of 1/10 KOH ethanol solution, B represents the titration (ml) of the blank test, T represents the titration (ml) of the sample, and W represents the mass (g) of the sample. C represents the concentration (mass%) of the sample.
The above N / 10HCl dioxane solution was prepared by taking 1 ml of concentrated hydrochloric acid with a measuring pipette and 100 ml of dioxane with a graduated cylinder into a 200 ml Erlenmeyer flask with a stopper, shaking well, and mixing well. Use the same thing.

  When the weight average molecular weight of the acrylic polymer is less than 30,000, the flexibility tends to be lowered and the coating tends to be brittle. Further, if the glycidyl acrylate contained as a polymerization component in the acrylic polymer is less than 2% by mass, the glass transition temperature Tg of the cured product tends to be lowered and the heat resistance tends to be insufficient, whereas 20% by mass. If it exceeds 1, the storage elastic modulus of the cured product tends to increase and the generation of resin powder or fibers cannot be sufficiently suppressed. Further, when the epoxy value of the acrylic polymer is less than 2, the glass transition temperature Tg of the cured product tends to be lowered and the heat resistance tends to be insufficient, whereas when it exceeds 36, the storage elasticity of the cured product is decreased. The rate tends to increase and the generation of resin powder or fibers cannot be sufficiently suppressed.

  Furthermore, in the composite of the present invention, the fiber sheet is preferably a glass cloth having a thickness of 10 to 200 μm. According to such a composite, an insulating substrate having sufficient mechanical strength, improved dimensional stability, and easier to increase the density of the multilayer printed wiring board can be obtained.

  In the composite of the present invention, the total thickness of the composite is preferably 100 μm or less. When the total thickness of the composite is 100 μm or less, when used as an insulating substrate constituting a multilayer printed wiring board, it becomes easier to increase the density.

  Furthermore, in the composite of the present invention, the composite preferably has a through hole. According to such a composite, a step of forming a through hole can be omitted by providing the through hole in a predetermined position in advance, and a multilayer printed wiring board having an IVH structure excellent in reliability by using such a composite Can be manufactured with high yield.

  The prepreg of the present invention is characterized in that, in the composite of the present invention, the curable resin composition is semi-cured.

  By using the curable resin composition described above, the prepreg of the present invention is sufficiently suppressed in the generation of resin powder or fibers that may fall off and has sufficiently excellent adhesion reliability. Yes. Therefore, when manufacturing the multilayer printed wiring board which has IVH structure using the prepreg of this invention, the multilayer printed wiring board excellent in reliability can be obtained.

  Furthermore, the prepreg of the present invention preferably has a through hole. According to such a prepreg, the step of forming the through-hole can be omitted because the through-hole is previously provided at a predetermined position. By using such a prepreg, a multilayer printed wiring board having an IVH structure excellent in reliability can be obtained. It can be manufactured easily.

  Further, the first metal foil-clad laminate of the present invention is a composite of the present invention having a through hole, in which the through hole is filled with a conductor and a metal foil is disposed on at least one surface of the composite, It is obtained by heating and pressing.

  By using the composite of the present invention, such a metal foil-clad laminate is sufficiently suppressed from falling off the resin powder or fibers from the metal foil-clad laminate and has sufficiently excellent adhesion reliability. is doing. Therefore, when manufacturing the multilayer printed wiring board which has IVH structure using the metal foil tension laminated board of this invention, the multilayer printed wiring board excellent in reliability can be obtained with a sufficient yield.

  Further, the second metal foil-clad laminate of the present invention is a prepreg of the present invention having a through-hole, in which a through-hole is filled with a conductor and a metal foil is disposed on at least one surface of the prepreg. It is obtained by pressing.

  Such a metal foil-clad laminate has a sufficiently excellent adhesion reliability while sufficiently preventing the resin powder or fibers from falling off the metal foil-clad laminate by using the prepreg of the present invention. ing. Therefore, when manufacturing the multilayer printed wiring board which has IVH structure using the metal foil tension laminated board of this invention, the multilayer printed wiring board excellent in reliability can be obtained with a sufficient yield.

  Further, the multilayer printed wiring board of the present invention has a through-hole, and an insulating substrate laminate composed of a plurality of insulating substrates in which a conductor is embedded in the through-hole, between each of the plurality of insulating substrates, and A multilayer printed wiring board having a wiring pattern disposed on at least one of the outer surfaces of the insulating substrate laminate and connected by a conductor, the constituent material of the outermost insulating substrate having the wiring pattern disposed on at least both surfaces Is a heat-resistant organic sheet, and all or part of the insulating substrate other than the outermost layer is any one of the composites of the present invention having through holes.

  In the multilayer printed wiring board of the present invention, the composite of the present invention is used which is excellent in the above-mentioned adhesion reliability and sufficiently suppressed from falling off resin powder and fibers on all or part of the insulating substrate other than the outermost layer, Furthermore, by using a heat-resistant organic sheet as a constituent material of the outermost insulating substrate, the heat resistance and mechanical strength of the entire multilayer printed wiring board are sufficiently improved, and the density and reliability of component mounting are increased. It is excellent in nature. Furthermore, by using a heat-resistant organic sheet as a constituent material of the outermost insulating substrate, the surface of the outermost insulating substrate is smoothed and a wiring pattern is formed, so that the wiring pattern pitch is made finer. Thus, the reliability and life characteristics of the entire substrate can be improved.

  Moreover, it is preferable that the adhesive layer for improving the adhesiveness with a wiring pattern and / or another insulating substrate is provided in the surface of the said heat resistant organic sheet of a multilayer printed wiring board.

  In such a multilayer printed wiring board, since the adhesive layer is provided on the outermost insulating substrate, the adhesion between the outermost insulating substrate and the wiring pattern and / or other insulating substrate is improved. High-density mounting of components on a printed wiring board can be more reliably performed.

  Furthermore, in the multilayer printed wiring board of the present invention, the surface before the adhesive layer of the heat-resistant organic sheet is provided on the surface is subjected to corona discharge treatment in order to improve the adhesion between the heat-resistant organic sheet and the adhesive layer. It is preferable that the unevenness is formed by at least one of plasma treatment, flame treatment, ultraviolet treatment, electron beam / radiation treatment, sandblast treatment, and chemical treatment.

  In such a multilayer printed wiring board, since the unevenness | corrugation is formed in the surface before providing the adhesive material layer of a heat resistant organic sheet, the adhesiveness of a heat resistant organic sheet and an adhesive material layer improves.

  In the multilayer printed wiring board of the present invention, the heat-resistant organic sheet may be a wholly aromatic polyamide resin, a polyimide resin, a wholly aromatic polyester resin, a polycarbonate resin, a polysulfone resin, a tetrafluoropolyethylene resin, or a hexafluoropolypropylene resin. , A polyether ether ketone resin, a polyphenylene ether resin, an acrylic resin, an epoxy resin, or a phenol resin.

Furthermore, the heat-resistant organic sheet preferably contains 5% by volume to 45% by volume of an inorganic filler made of one kind or a mixture of two or more kinds of Al ₂ O ₃ , TiO ₂ , MgO, and SiO ₂ .

  Since the heat-resistant organic sheet of such a multilayer printed wiring board contains 5% to 45% by volume of the inorganic filler, the heat resistance, mechanical strength, and dimensional stability of the heat-resistant organic sheet are improved.

  The first method for producing a multilayer printed wiring board according to the present invention includes forming a predetermined through hole in an insulating substrate comprising the composite of the present invention as described above, and filling the through hole with a conductor. A process of preparing a printed wiring board for an inner layer by laminating a metal foil on the surface of the insulating substrate and forming a wiring pattern using the metal foil, and a predetermined penetration through the insulating substrate made of a heat-resistant organic sheet Forming a hole, filling the through hole with a conductor, attaching a metal foil to the surface of the insulating substrate, and forming a wiring pattern using the metal foil; and preparing a printed wiring board for the outermost layer; The outermost layer printed wiring board is arranged such that the outermost layer printed wiring board is arranged in the outermost layer and the inner layer printed wiring board is arranged in all or part of the layers other than the outermost layer. Laminating the board and the printed wiring board for the inner layer Forming a printing wiring board laminate, a printed wiring board laminate by heating and pressing to adhere, characterized by comprising a step of electrically connecting the wiring pattern using a conductive material.

  Further, the second method for producing the multilayer printed wiring board of the present invention is to form a predetermined through hole in the insulating substrate comprising the composite of the present invention as described above, and fill the through hole with a conductor. A process of preparing a printed wiring board for an inner layer by laminating a metal foil on the surface of the insulating substrate and forming a wiring pattern using the metal foil, and a predetermined penetration through the insulating substrate made of a heat-resistant organic sheet Forming a hole and filling the through hole with a conductor to prepare an outermost layer printed wiring board; and so that the outermost layer printed wiring board is disposed on the outermost layer and other than the outermost layer Laminating the outermost layer printed wiring board and the inner layer printed wiring board to form the printed wiring board laminate so that the inner layer printed wiring board is disposed in all or a part of the layer; A predetermined wiring pattern is placed outside the outermost layer of the printed wiring board laminate. A mold release support plate is placed, heated and pressurized, and the wiring pattern of the release support plate is transferred to the heat-resistant organic sheet, and the printed wiring board laminate is bonded to the conductor. And a step of electrically connecting the wiring patterns and then peeling off the releasable support plate.

  In these multilayer printed wiring board manufacturing methods, the composite of the present invention, which is excellent in the above-mentioned adhesion reliability and sufficiently suppressed from falling off resin powder and fibers, is used for all or part of the insulating substrate other than the outermost layer. Furthermore, by using a heat-resistant organic sheet as the constituent material of the outermost insulating substrate, the heat resistance and mechanical strength of the entire multilayer printed wiring board can be sufficiently improved, and the density of component mounting is increased. In addition, it is possible to have excellent reliability. Further, since the occurrence of disconnection or the like can be sufficiently suppressed, the yield is excellent. Furthermore, since the surface of the outermost insulating substrate is smoothed and the wiring pattern is formed, the wiring pattern pitch can be reduced, and the reliability and life characteristics of the entire substrate can be improved.

  Moreover, the method for producing a multilayer printed wiring board of the present invention includes a step of providing an adhesive layer on the surface of the heat-resistant organic sheet for improving the adhesion to the wiring pattern and / or other insulating substrate. It is preferable.

  In such a method for manufacturing a multilayer printed wiring board, since the adhesive layer is provided on the outermost insulating substrate, the adhesion between the outermost insulating substrate and the wiring pattern and / or other insulating substrate can be improved. it can.

  Furthermore, in the manufacturing method of the multilayer printed wiring board of the present invention, in order to improve the adhesion between the heat-resistant organic sheet and the adhesive layer on the surface before the adhesive layer of the heat-resistant organic sheet is provided, It is preferable to include a step of forming irregularities by at least one of corona discharge treatment, plasma treatment, flame treatment, ultraviolet treatment, electron beam / radiation treatment, sandblast treatment, and chemical treatment.

  In such a method for producing a multilayer printed wiring board, since the unevenness is formed on the surface before the adhesive layer of the heat resistant organic sheet is provided, the adhesion between the heat resistant organic sheet and the adhesive layer can be improved. .

In the method for manufacturing a multilayer printed wiring board of the present invention, the heat-resistant organic _sheet, Al ₂ O _3, TiO 2, MgO, inorganic filler consisting of one or more kinds of mixture of SiO ₂ It is preferable to contain 5 volume%-45 volume%.

  In such a method for producing a multilayer printed wiring board, a heat-resistant organic sheet containing 5% to 45% by volume of an inorganic filler is used, so that the heat resistance, mechanical strength and dimensional stability of the heat-resistant organic sheet are improved. Can be made.

  ADVANTAGE OF THE INVENTION According to this invention, the composite_body | complex which is excellent in adhesion reliability and generation | occurrence | production of the resin powder or fiber which may drop | omit is fully suppressed can be provided. Moreover, according to this invention, the prepreg using this composite_body | complex and a sheet | seat with metal foil can be provided. Furthermore, according to the present invention, it is possible to provide a multilayer printed wiring board that can increase the density of component mounting and has sufficiently excellent reliability, and a method for manufacturing such a multilayer printed wiring board.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  First, an embodiment of the composite of the present invention will be described. FIG. 1 is a schematic cross-sectional view showing one embodiment of the composite of the present invention. A composite 100 in FIG. 1 is formed by impregnating a fiber sheet 101 with a curable resin composition 102. The composite 100 includes a through hole 103.

  Examples of the fiber sheet 101 include heat resistant synthetic fibers such as paper, glass cloth such as glass fiber woven fabric and glass fiber nonwoven fabric, and aramid nonwoven fabric. Among these, a glass fiber woven fabric and a glass fiber nonwoven fabric are preferable, and a glass fiber woven fabric is particularly preferable. Examples of the glass material include E glass, S glass, and D glass. Moreover, about the weaving method of the fiber when using a woven fabric as a fiber sheet, a plain weave, satin weave, twill weave, etc. are mentioned, for example.

  About the thickness of a fiber sheet, if the fiber sheet has sufficient intensity | strength, the thinner one is preferable. Specifically, for example, the thickness is preferably 10 to 200 μm, and more preferably 10 to 80 μm. The fiber sheet is preferably one having a smaller linear expansion coefficient.

  The curable resin composition 102 only needs to have a storage elastic modulus at 20 ° C. of 100 to 2000 MPa of the cured product, and includes, for example, a curable resin and a curing agent that cures the curable resin. Things. As the resin component of the curable resin, it is preferable to use a viscoelastic resin, and examples thereof include epoxy resins, rubber-modified epoxy resins, SBR, NBR, CTBN, acrylic resins, polyamides, polyamideimides, and silicone-modified polyamideimides. . Examples of the curing agent include dicyandiamide, phenol resin, imidazole, amine compound, acid anhydride and the like.

  The curable resin composition 102 can be used as a varnish containing a predetermined solvent for the purpose of impregnating the fiber sheet. Solvents used include aromatic hydrocarbon solvents such as benzene, toluene, xylene and trimethylbenzene; ether solvents such as tetrahydrofuran; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; glycol ethers such as methyl cellosolve and diethylene glycol. System solvents; ester solvents such as methyl cellosolve acetate; dialkyl glycol solvents such as ethylene glycol dimethyl ether; amide solvents such as N-methylpyrrolidone, N, N′-dimethylformamide, N, N′-dimethylacetamide; methanol, Alcohol solvents such as butanol and isopropanol; ether alcohol solvents such as 2-methoxyethanol and 2-butoxyethanol can be used, and one or more of these can be used. It can be used.

  In the present embodiment, it is preferable to use a combination of a curable acrylic polymer and a curing agent that cures the acrylic polymer as the curable resin composition. In this case, it is preferable to use the curing agent in a proportion of 60 to 350 parts by mass with respect to 100 parts by mass of the acrylic polymer. When the curing agent is less than 60 parts by mass with respect to 100 parts by mass of the acrylic resin, the storage elastic modulus of the cured product tends to be less than 300 MPa, the handleability is lowered, and the Tg of the cured product is lowered, resulting in a high temperature. There is a tendency that problems such as dimensional shrinkage due to deterioration during standing and a decrease in solder heat resistance are likely to occur. On the other hand, when the ratio of the curing agent exceeds 350 parts by mass, the storage elastic modulus of the cured product tends to exceed 2000 MPa. In this case, the cured product becomes brittle, and thus the resin powder or fibers tend to fall off.

  The acrylic polymer preferably has a weight average molecular weight (Mw) of 30000 or more. Further, the acrylic polymer has 2 to 20% by mass of glycidyl acrylate as a polymerization component in the polymer. The epoxy value is preferably 2 to 36.

  Examples of the method for producing the composite 100 include a method in which a fiber sheet is impregnated with a curable resin composition and dried, and then a through hole is formed at a predetermined position. Examples of the method of impregnating the fiber sheet with the curable resin composition include, for example, a method of immersing the fiber sheet in a resin composition solution such as a wet method and a dry method, and a method of applying the curable resin composition to the fiber sheet. Etc.

  The amount of the curable resin composition impregnated into the fiber sheet may be adjusted so that the ratio Va / Vb of the volume Va of the curable resin composition to the volume Vb of the fiber sheet is 0.3 to 0.9. preferable. Here, the volume ratio can be obtained from the weight of the fiber sheet and the curable resin composition contained in the composite and the specific gravity of each.

  Next, a preferred embodiment of the prepreg of the present invention will be described.

  FIG. 2 is a schematic cross-sectional view showing an embodiment of the prepreg of the present invention. A prepreg 200 shown in FIG. 2 includes a fiber sheet 201 and a semi-cured resin composition layer 202 obtained by semi-curing a curable resin composition impregnated in the fiber sheet 201. Further, the prepreg 200 includes a through hole 203.

  The prepreg 200 can be obtained by semi-curing the curable resin composition 102 in the composite 100 described above. In this case, the fiber sheet 201 is the same as the fiber sheet 101, and the semi-cured resin composition layer 202 is obtained by semi-curing the curable resin composition 102. As another method, the prepreg 200 is prepared by impregnating the above curable resin composition into the above fiber sheet and drying, and then semi-curing the curable resin composition to obtain a semi-cured resin composition. It can also be obtained by forming the through hole 203 at a predetermined position after forming the physical layer 202.

  Examples of the method for semi-curing the curable resin composition include methods such as heating, ultraviolet irradiation, and electron beam irradiation. Examples of the conditions for semi-curing by heating include conditions of 100 to 200 ° C. and 1 to 30 minutes.

  In the prepreg of this embodiment, it is preferable that the curing rate of the curable resin composition be in the range of 10 to 70%. When the curing rate of the curable resin composition is less than 10%, when integrated with the conductor, the unevenness of the fiber sheet is reflected on the surface of the integrated conductor layer, and the surface smoothness tends to decrease, Further, it tends to be difficult to control the thickness of the insulating substrate. On the other hand, when the curing rate of the curable resin composition exceeds 70%, the resin component is insufficient when integrated with the conductor layer, and when integrated at a high speed, bubbles and blurring tend to occur. Adhesive strength tends to be insufficient.

  Next, an embodiment of the metal foil-clad laminate of the present invention will be described.

  FIG. 3 is a schematic cross-sectional view showing an embodiment of the metal foil-clad laminate of the present invention. A metal foil-clad laminate 300 shown in FIG. 3 includes an insulating substrate 301 having a through hole 303, a conductor 304 filled in the through hole 303, and a conductor layer 302 stacked on the insulating substrate 301. Has been.

  Examples of the conductor layer 302 include metal foil such as copper foil, aluminum foil, and nickel foil. In the metal foil-clad laminate of this embodiment, the conductor layer 302 is preferably a copper foil, and the thickness is preferably 1 to 70 μm. Moreover, electrolytic copper foil, rolled copper foil, etc. can be used for copper foil. In the metal foil-clad laminate of this embodiment, the conductor layer 302 may be a film having conductivity, and other than the above metal foil, for example, a metal, an organic substance, and a composite thereof may be used. Good.

  Examples of the conductor 304 include a heat-pressed one of a conductive paste containing a metal such as gold, silver, nickel, copper, platinum, palladium, ruthenium oxide, a metal oxide, an organometallic compound, or the like.

  The insulating substrate 301 having the through hole 303 is formed using the composite 100 or the prepreg 200 described above.

  For example, when the metal foil-clad laminate 300 is obtained using the prepreg 200, first, the conductive paste is filled into the through holes 203 of the prepreg 200. Next, a metal foil as a conductor layer is arranged on the surface of the prepreg 200, and the metal foil and the prepreg can be integrated to manufacture the metal foil-clad laminate 300. Further, even if the composite 100 is used instead of the prepreg 200, the metal foil-clad laminate 300 can be similarly manufactured.

Examples of the method for integrating the metal foil with the prepreg or the composite include metallization, press lamination method, and hot roll continuous lamination method. In the present embodiment, it is preferable to use the press lamination method from the viewpoint of efficiently forming the conductor layer. Examples of the heating and pressing conditions for integrating the metal foil and the prepreg or the composite by the press lamination method include a temperature of 120 to 230 ° C., a pressure of 10 to 60 kg / cm ² , and a heating time of 30 to 120 minutes. A range condition is mentioned.

  Next, an embodiment of the multilayer printed wiring board of the present invention will be described.

  FIG. 4 is a schematic cross-sectional view showing an embodiment of the multilayer printed wiring board of the present invention. A multilayer printed wiring board 400 shown in FIG. 4 includes, as outermost layers, an insulating substrate 420a in which a through hole 421a is filled with a conductor 422a, an insulating substrate 420b in which a through hole 421b is filled with a conductor 422b, and The inner layer is composed of an insulating substrate 410 in which a through hole 411 is filled with a conductor 412. The insulating substrate 420a has a wiring pattern 423a on the side surface opposite to the inner layer, and the insulating substrate 420b has a wiring pattern 423b on the side surface opposite to the inner layer. Furthermore, the multilayer printed wiring board 400 includes a wiring pattern 413a between the insulating substrate 420a and the insulating substrate 410, and includes a wiring pattern 413b between the insulating substrate 420b and the insulating substrate 410.

  The insulating substrate 410 is an insulating substrate formed by heating the composite 100 or the prepreg 200 described above.

  The insulating substrates 420a and 420b are heat-resistant organic sheets, for example, wholly aromatic polyamide resin, polyimide resin, wholly aromatic polyester resin, polycarbonate resin, polysulfone resin, tetrafluoropolyethylene resin, hexafluoropolypropylene. Examples include resins, polyether ether ketone resins, polyphenylene ether resins, acrylic resins, epoxy resins, and phenol resins. Examples of the commercially available wholly aromatic polyamide resin sheet include “Aramika” (manufactured by Asahi Kasei Co., Ltd.).

  Examples of the conductors 412, 422a, and 422b include those formed from a conductive paste containing a metal such as gold, silver, nickel, copper, platinum, palladium, ruthenium oxide, a metal oxide, an organometallic compound, or the like.

  Next, the first to third embodiments of the method for producing a multilayer printed wiring board according to the present invention will be described in detail by way of examples. In addition, the weight average molecular weight and epoxy value of the acrylic polymer used in Examples and Comparative Examples were determined according to the following methods.

(Weight average molecular weight of acrylic polymer)
The weight average molecular weight of the acrylic polymer was determined by gel permeation chromatography (GPC) under the following conditions and converted using a standard polystyrene calibration curve.
(GPC conditions)
Detector: HLC-8120GPC [manufactured by Tosoh Corporation]
Column: GMH _XL equivalent product (3) (manufactured by TOSOH, trade name “TSKgel G5000H”)
Column size: 7.5mmφ × 300mm
Eluent: THF
Sample concentration: 5 mg / 1 mL
Injection volume: 50 μL
Pressure: 50 kgf / cm ²
Flow rate: 1.0 mL / min

(Epoxy value of acrylic polymer)
The epoxy value was determined according to the following procedure.
1) Weigh accurately 2.5 g of sample (acrylic polymer) in a 100 ml Erlenmeyer flask with a stopper.
2) Add about 20 ml of methyl ethyl ketone (MEK) and stir and dissolve the sample for about 5 minutes.
3) Add 10 ml of N / 10 HCl dioxane solution with a whole pipette, stopper and shake gently. Confirm that it is transparent and uniform, and let stand for 10 minutes.
4) Add about 4 ml of ethanol, add 5 drops of phenolphthalein indicator, and titrate with 1/10 KOH ethanol solution. The end point is the time when it is colored light pink.
5) Titrate the blank prepared separately in the same way (blank test).
6) The epoxy value is calculated by the following formula.
Epoxy value (eq / 100 g) = (f × (BT)) / (W × c)
In the above formula, f represents the factor of 1/10 KOH ethanol solution, B represents the titration (ml) of the blank test, T represents the titration (ml) of the sample, and W represents the mass (g) of the sample. C represents the concentration (mass%) of the sample.
The above N / 10HCl dioxane solution was prepared by taking 1 ml of concentrated hydrochloric acid with a measuring pipette and 100 ml of dioxane with a graduated cylinder into a 200 ml Erlenmeyer flask with a stopper, shaking well, and mixing well. Used.

  Moreover, the storage elastic modulus in 20 degreeC of the hardened | cured material of the curable resin composition used by the Example and the comparative example was calculated | required in the following procedures. First, a varnish containing a curable resin composition is applied to an electrolytic copper foil (made by Furukawa Electric Co., Ltd., trade name “F2-WS-12”) having a thickness of 12 μm so that the coating thickness is about 50 to 100 μm. And heated at 180 ° C. for 60 minutes. Next, the cured resin obtained by removing the copper foil by etching was cut out to about 30 mm × 5 mm, and this was used as a sample for measuring storage elastic modulus. About this measurement sample, the dynamic viscoelasticity curve was obtained by measuring on the conditions of measurement length 20mm and measurement frequency 10Hz using the dynamic viscoelasticity measuring apparatus "Reogel-E-4000" (made by UBM). And the elastic modulus of 20 degreeC of the obtained dynamic viscoelastic curve was made into the said storage elastic modulus.

Example 1
5, 6 and 7 are schematic cross-sectional views for explaining the first embodiment of the method for producing a multilayer printed wiring board of the present invention.

(Production of composite and prepreg)
The following curable resin composition in which the storage elastic modulus at 20 ° C. of the cured product becomes 700 MPa by heat treatment at 180 ° C. for 60 minutes is dissolved in the organic solvent methyl ethyl ketone, the viscosity is adjusted to 700 cP, and the varnish (resin solid content 30 mass) %) Was adjusted.
Acrylic resin composition “HTR-860P3” (Nagase ChemteX Corporation, weight average molecular weight: about 850,000), epoxy value: 3): 100 parts by mass epoxy resin “Epicoat-828” (Japan Epoxy Resin Co., Ltd.) : 60 parts by mass novolak-type phenolic resin "Novolac phenol VP 6371" (Hitachi Chemical Industry Co., Ltd .: 40 parts by mass curing agent "imidazole 2PZ-CN" (Shikoku Kasei Co., Ltd.): 0.4 parts by mass

  Next, using an impregnation coating machine, the varnish obtained as described above was applied to a glass cloth “Glass Cloth # 1037” (Nittobo Co., Ltd.) having a thickness of 0.04 mm. The composite was obtained by impregnation so that the volume was 0.6.

  Subsequently, the composite was dried with hot air at 150 ° C. for 5 minutes to prepare a prepreg having a curing rate of 30% of the curable resin composition.

(Manufacture of multilayer printed wiring boards)
<Preparation of printed wiring board for inner layer>
A prepreg 210 having a release film 430 (16 μm thick) made of polyethylene terephthalate or the like on both surfaces of the prepreg obtained above was prepared. Next, as shown in FIG. 5A, a through hole 411 having a hole diameter of 200 μm was formed at a predetermined position of the prepreg 210 by a laser processing machine. By using the laser processing machine in this way, the through-hole 411 having a fine diameter can be easily formed at high speed.

  Then, as shown in FIG.5 (b), after filling the through-hole 411 with the electrically conductive paste 3, the release film 430 was peeled and removed. The conductive paste 3 is a solventless epoxy resin as a binder resin mixed with 90% by mass of copper powder having an average particle size of 2 μm as a conductive material, and this mixture is mixed into a three-roll kneader. Were mixed uniformly. In the present invention, metal powder can be used instead of the conductive paste.

  Moreover, as a method of filling the conductive paste 3 into the through holes 411, a printing method in which printing is applied from above the release film 430 by a squeegee method or a roll transfer method can be cited. In this case, the releasable film 430 functions as a printing mask and can prevent the surface of the prepreg 210 from being contaminated by the conductive paste 3. In the present embodiment, the conductive paste 3 was filled in the through holes 411 by printing and applying by the squeegee method.

Then, as shown in FIG.5 (c), the 35-micrometer-thick copper foil 4 was each arrange | positioned on both surfaces of the prepreg 210, and it heated, applying the pressure of 60 kg / cm < ² > in a vacuum. The temperature history was raised from room temperature to 200 ° C. in 30 minutes, held at 200 ° C. for 60 minutes, and then lowered from 200 ° C. to room temperature in 30 minutes. By this heating and pressing, the prepreg 210 is cured to become the insulating substrate 410, the conductive paste 3 is converted into the conductor 412, and the copper foils 4 on both sides are bonded to the insulating substrate 410. Thereby, the copper foils 4 on both sides are electrically connected via the conductor 412 in the through hole 411.

  Subsequently, as shown in FIG. 5 (d), the copper foil 4 is patterned by a photolithographic method to form a wiring pattern 413a and a wiring pattern 413b, and the printed wiring board for inner layer 450 having wiring patterns on both sides is formed. Got.

<Preparation of outermost intermediate connector>
On the other hand, an outermost layer intermediate connector constituting the outermost layer of the multilayer printed wiring board was produced. In the same manner as the prepreg 210 shown in FIG. 5A, an insulating substrate provided with a release film 7 (16 μm thickness) made of polyethylene terephthalate or the like on both surfaces of the heat-resistant organic sheet 420 was prepared. Next, as shown in FIG. 6A, a through hole 421 having a hole diameter of 200 μm was formed at a predetermined position of the heat-resistant organic sheet 420 in the same manner as the prepreg 210 in FIG. . In Example 1, a sheet of wholly aromatic polyamide resin (product name “Aramika”, thickness: 30 μm, manufactured by Asahi Kasei) was used as the heat-resistant organic sheet 420. Further, the adhesive strength of the inner layer printed wiring board 450 to be laminated later on the copper foil wiring pattern wiring patterns 413a and 413b, the inner layer printed wiring board 450 and the like is enhanced on both surfaces of the heat-resistant organic sheet 420. For this purpose, an adhesive made of a rubber-modified epoxy resin having a thickness of 10 μm was used. In addition, instead of the heat-resistant organic sheet 420 to which an adhesive is applied, an adhesive that can sufficiently adhere to a copper foil with the inner layer printed wiring board 450 and the wiring patterns 413a and 413b, for example, a printed wiring board In the case of using a heat-sealable polyimide sheet or the like that can obtain a high adhesive force only by heating and pressing with respect to the copper foil for use, it is possible to omit application of the adhesive.

  And as shown in FIG.6 (b), it filled with the electrically conductive paste 3 which has moderate viscosity and fluidity | liquidity to the through-hole 421 similarly to the prepreg 210 demonstrated using FIG.5 (b). Thereafter, the releasable film 430 was peeled and removed to obtain an outermost intermediate connection body 460.

  Similarly, another outermost layer intermediate connector 460 was prepared. For convenience of the following description, the two outermost layer intermediate connectors 460 described above are referred to as an outermost layer intermediate connector 460a and an outermost layer intermediate connector 460b.

<Production of multilayer printed wiring board>
Next, as shown in FIG. 7A, outermost layer intermediate connectors 460a and 460b are arranged on both sides of the inner layer printed wiring board 450 of FIG. 5D, and the outermost layer intermediate connector 460a. A metal foil made of copper foil 4a and 4b having a thickness of 35 μm is arranged on the outside of 460b, and the temperature is raised from room temperature to 200 ° C. in 30 minutes while applying a pressure of 60 kg / cm ² in a vacuum. After holding for 60 minutes, the temperature was lowered to room temperature in 30 minutes. In this way, the inner layer printed wiring board 450 is bonded to the outermost layer intermediate connector 460a and the outermost layer intermediate connector 460b, and further, the outermost layer intermediate connector 460a, the copper foil 4a, and the outermost layer The intermediate connection body 460b and the copper foil 4b were bonded.

  Thereafter, as shown in FIG. 7B, the copper foils 4a and 4b of FIG. 7A are patterned by the photolithographic method to form the wiring patterns 8a and 8b, and the outer layer wiring patterns 8a and 8b. And the multilayer printed wiring board 401 of Example 1 provided with the wiring pattern of 4 layers of inner layer wiring patterns 413a and 413b was obtained.

  Next, 2nd Embodiment of the manufacturing method of the multilayer printed wiring board of this invention is described.

(Example 2)
8, 9 and 10 are schematic cross-sectional views for explaining a second embodiment of the method for producing a multilayer printed wiring board of the present invention.

<Preparation of intermediate connection for inner layer>
First, as shown to Fig.8 (a), the prepreg 210 which provided the release film 430 which consists of a polyethylene terephthalate etc. on both surfaces of the prepreg obtained by carrying out similarly to Example 1 was prepared. Next, as shown in FIG. 8A, a through hole 411 having a hole diameter of 200 μm was formed at a predetermined position of the prepreg 210 by a laser processing machine.

  Subsequently, as shown in FIG. 8B, the through-hole 411 was filled with the conductive paste 3, and then the release film 430 was peeled off to obtain an inner layer intermediate connector 470.

<Preparation of printed wiring board for outermost layer>
On the other hand, an outermost printed wiring board constituting the outermost layer of the multilayer printed wiring board was produced. In the same manner as in Example 1, an insulating substrate provided with a release film 7 (16 μm thick) made of polyethylene terephthalate or the like on both surfaces of a heat-resistant organic sheet 420 was prepared. Next, in the same manner as in Example 1, as shown in FIG. 9A, a through hole 421 having a hole diameter of 200 μm was formed at a predetermined position of the heat-resistant organic sheet 420 by a laser processing machine.

  And as shown in FIG.9 (b), after filling the through-hole 421 with the electrically conductive paste 3 which has moderate viscosity and fluidity | liquidity, the release film 430 is peeled and removed, and the intermediate connection for outermost layers A body 460 was obtained.

Subsequently, as shown in FIG. 9C, metal foils made of copper foil 14 having a thickness of 35 μm are arranged on both surfaces of the outermost intermediate connector 460, respectively, and a pressure of 60 kg / cm ² is applied in a vacuum. While being added, the temperature is raised from room temperature to 200 ° C. in 30 minutes, held at 200 ° C. for 60 minutes, and then lowered to room temperature in 30 minutes, whereby the heat-resistant organic sheet 420 and the conductive paste of the intermediate connection body 460 for the outermost layer 3 is compressed and cured, the copper foils 14 on both sides are bonded to the heat-resistant organic sheet 420, and the copper foils 14 on both sides are electrically connected via the conductors 422 in the through holes 421. A circuit board was obtained.

  Subsequently, as shown in FIG. 9 (d), the copper foil 14 was patterned by a photolithographic method to form a wiring pattern 424 a and a wiring pattern 425 a, thereby obtaining an outermost layer printed wiring board 480.

  Similarly, another printed wiring board 480 for the outermost layer was prepared separately. For convenience of the following description, the two outermost printed wiring boards 480 described above are referred to as an outermost printed wiring board 480a and an outermost printed wiring board 480b.

<Production of multilayer printed wiring board>
Next, as shown in FIG. 10 (b), an inner layer intermediate connector 470 is disposed between two outermost printed wiring boards 480a and 480b each having a different wiring pattern, and the inner layer intermediate connector 470 is disposed. The inner layer intermediate connector 470 and the conductive paste 3 in a prepreg state were compressed and cured by heating and pressing from the outside of the printed wiring boards 480a and 480b. Then, the multilayer printed wiring board 402 of Example 2 having the four-layer wiring patterns of the outer layer wiring patterns 424a and 424b and the inner layer wiring patterns 425a and 425b as shown in FIG. 10B was obtained.

  Next, a third embodiment of the method for producing a multilayer printed wiring board according to the present invention will be described.

(Example 3)
FIG. 11 is a schematic cross-sectional view for explaining a third embodiment of the method for producing a multilayer printed wiring board according to the present invention.

  The third embodiment of the method for producing a multilayer printed wiring board according to the present invention is the same as the method for producing a multilayer printed wiring board shown in Example 1 in that the formation of the outer layer wiring pattern is changed from the photolithographic method to the transfer method. This is different from the first embodiment. Therefore, the production of the printed wiring board for the inner layer (FIGS. 5A to 5D) and the production of the intermediate connector for the outermost layer (FIGS. 6A and 6B) were performed in the same manner as in Example 1. .

  Next, as shown in FIG. 11A, the outermost layer intermediate connector 460a obtained in the same manner as in Example 1 is formed on both surfaces of the printed wiring board for inner layer 450 obtained in the same manner as in Example 1. 460b. Furthermore, the release conductive support plates 28a and 28b in which the wiring patterns 18a and 18b are respectively formed in advance are disposed on the outer side of the outermost layer intermediate connectors 460a and 460b. Then, the conductive paste 3 is compressed and cured by heating and pressurizing them, and the wiring pattern is formed through the adhesive applied to the surfaces of the heat-resistant organic sheets 420a and 420b of the outermost intermediate connection bodies 460a and 460b, respectively. 18a and 18b were adhered to the outermost layer intermediate connectors 460a and 460b. After the compression and curing reaction is completed, the outer surfaces of the heat-resistant organic sheets 420a and 420b as shown in FIG. 11B are smoothed by peeling off the release conductive support plates 28a and 28b. The multilayer printed wiring board 403 of Example 3 provided with the wiring pattern of was obtained.

Example 4
In Example 1, instead of the curable resin composition having a storage elastic modulus of 700 MPa, the following curable resin composition having a storage elastic modulus at 20 ° C. of 300 MPa by heat treatment at 180 ° C. for 60 minutes is 300 MPa. The curable resin composition was dissolved in the organic solvent methyl ethyl ketone, the viscosity was adjusted to 500 cP, and the varnish (resin solid content 25% by mass) was adjusted to obtain an example. 4 multilayer printed wiring boards were obtained.
Acrylic resin composition “HTR-860P3” (Nagase ChemteX Corporation, weight average molecular weight: about 850,000, epoxy value: 3): 250 parts by mass epoxy resin “Epicoat-828” (Japan Epoxy Resin Co., Ltd.): 40 parts by mass novolak-type phenolic resin “Novolac phenol VP 6371” (Hitachi Chemical Industry Co., Ltd .: 40 parts by mass curing agent “imidazole 2PZ-CN” (Shikoku Kasei Co., Ltd.): 0.4 parts by mass

(Example 5)
In Example 1, in place of the curable resin composition having a storage elastic modulus of 700 MPa, the following curable resin composition having a storage elastic modulus at 20 ° C. of 1900 MPa after heat treatment at 180 ° C. for 60 minutes is 1900 MPa. The curable resin composition was dissolved in an organic solvent methyl ethyl ketone, the viscosity was adjusted to 1000 cP, and the varnish (resin solid content: 50% by mass) was adjusted. 5 multilayer printed wiring boards were obtained.
Acrylic resin composition “HTR-860P3” (Nagase ChemteX Corporation, weight average molecular weight: about 850,000, epoxy value: 3): 20 parts by mass epoxy resin “Epicoat-828” (Japan Epoxy Resin Co., Ltd.): 40 parts by mass novolak-type phenolic resin “Novolac phenol VP 6371” (Hitachi Chemical Industry Co., Ltd .: 40 parts by mass curing agent “imidazole 2PZ-CN” (Shikoku Kasei Co., Ltd.): 0.4 parts by mass

(Example 6)
In Example 1, in place of the curable resin composition having a storage elastic modulus of 700 MPa, the following curable resin composition having a storage elastic modulus at 20 ° C. of 150 MPa by heat treatment at 180 ° C. for 60 minutes is 150 MPa. A multilayer printed wiring board of Example 6 was obtained in the same manner as in Example 1 except that the curable resin composition was dissolved in the organic solvent methyl ethyl ketone.
Acrylic resin composition “HTR-860P3” (Nagase ChemteX Corporation, weight average molecular weight: about 850,000, epoxy value: 3): 350 parts by mass of epoxy resin “Epicoat-828” (Japan Epoxy Resin Co., Ltd.): 40 parts by mass novolak-type phenolic resin “Novolac phenol VP 6371” (Hitachi Chemical Industry Co., Ltd .: 40 parts by mass curing agent “imidazole 2PZ-CN” (Shikoku Kasei Co., Ltd.): 0.4 parts by mass

(Comparative Example 1)
In Example 1, instead of the curable resin composition having a storage elastic modulus of 700 MPa, the following curable resin composition in which the storage elastic modulus at 20 ° C. of the cured product is 3500 MPa by heat treatment at 180 ° C. for 60 minutes. The curable resin composition was dissolved in an organic solvent methyl ethyl ketone / propylene glycol monomethyl ether (mass ratio: 80/20), and the viscosity was adjusted to 300 cP to prepare a varnish (resin solid content 70 mass%). A multilayer printed wiring board of Comparative Example 1 was obtained in the same manner as Example 1 except that.
Brominated bisphenol A type epoxy resin (manufactured by Japan Epoxy Resin Co., Ltd., trade name “Epicoat 5046”, epoxy equivalent: 530): 100 parts by mass epoxy resin “Epicoat-828” (Japan Epoxy Resin Co., Ltd.): 40 mass Part dicyandiamide: 4 parts by mass curing agent “imidazole 2E4MZ” (Shikoku Kasei Co., Ltd.): 0.5 parts by mass

(Comparative Example 2)
In Example 1, instead of the curable resin composition having a storage elastic modulus of 700 MPa, the following curable resin composition having a storage elastic modulus at 20 ° C. of 2100 MPa by heat treatment at 180 ° C. for 60 minutes is 2100 MPa. The curable resin composition was dissolved in an organic solvent methyl ethyl ketone, the viscosity was adjusted to 400 cP, and the varnish (resin solid content: 30% by mass) was adjusted. 2 multilayer printed wiring boards were obtained.
Acrylic resin composition (weight average molecular weight: about 20000): 80 parts by mass epoxy resin “Epicoat-828” (Japan Epoxy Resin Co., Ltd.): 40 parts by mass novolac type phenolic resin “Novolac phenol VP 6371” (Hitachi Chemical Industry Co., Ltd.) ): 40 parts by mass Curing agent “Imidazole 2PZ-CN” (Shikoku Kasei Co., Ltd.): 0.4 parts by mass

(Comparative Example 3)
In Example 1, instead of the curable resin composition having a storage elastic modulus of 700 MPa, the following curable resin composition in which the storage elastic modulus at 20 ° C. of the cured product becomes 80 MPa by heat treatment at 180 ° C. for 60 minutes. A multilayer printed wiring board of Comparative Example 3 was obtained in the same manner as in Example 1 except that the curable resin composition was dissolved in the organic solvent methyl ethyl ketone.
Acrylic resin composition “HTR-860P3” (Nagase ChemteX Corporation, weight average molecular weight: about 850,000, epoxy value: 3): 500 parts by mass epoxy resin “Epicoat-828” (Japan Epoxy Resin Co., Ltd.): 40 parts by mass novolak-type phenolic resin “Novolac phenol VP 6371” (Hitachi Chemical Industry Co., Ltd .: 40 parts by mass curing agent “imidazole 2PZ-CN” (Shikoku Kasei Co., Ltd.): 0.4 parts by mass

  About the multilayer printed wiring board of Examples 1-6 and Comparative Examples 1-3 obtained above, 90 degree | times bending property and heat resistance were evaluated based on the following method. In addition, in each wiring board used for evaluation, the position and number of through holes and the wiring pattern were the same.

(90 degree bendability)
Multilayer printed wiring boards each having a width of 10 mm and a length of 100 mm prepared in the same manner as in Examples 1 to 6 and Comparative Examples 1 to 3 were prepared as samples for evaluation, and an aluminum plate having a thickness of 5 mm was formed on these samples. Was placed at right angles to the length direction of the sample, and the sample was bent at 90 degrees. The state of the sample after bending at 90 degrees was visually observed to check for cracks and breaks. The cases where no cracks or breaks were observed are indicated by “OK” in Table 1, and the cases where cracks or breaks were observed are indicated by “NG” in Table 1.

(Heat-resistant)
Each multilayer printed wiring board produced in the same manner as in Examples 1 to 6 and Comparative Examples 1 to 3 was cut into 50 mm × 50 mm to obtain evaluation samples. These samples were floated on molten solder at 288 ° C., the samples were visually observed, and the heat resistance was evaluated based on the following evaluation criteria. The results are shown in Table 1.
“OK”: No abnormality such as blistering or peeling occurs for 5 minutes or more after floating on the solder.
“NG”: Abnormalities such as blistering and peeling occurred within 5 minutes after the solder floated.

As Table 1 shows, it turned out that the multilayer printed wiring board of Examples 1-6 has sufficient heat resistance while it has sufficient bendability. On the other hand, in the multilayer printed wiring boards of Comparative Examples 1 and 2 produced using a composite containing a curable resin composition having a storage elastic modulus exceeding 2000 MPa, in the heat resistance evaluation, the resin powder or fibers are caused to fall off. Abnormalities such as blistering and peeling occurred. Moreover, in the multilayer printed wiring board of Comparative Example 3 produced using a composite containing a curable resin composition having a storage modulus of less than 100 MPa, the dimensional stability is insufficient in the heat resistance evaluation. Abnormalities such as blistering and peeling that may be caused occurred.

FIG. 1 is a schematic cross-sectional view showing one embodiment of the composite of the present invention. FIG. 2 is a schematic cross-sectional view showing an embodiment of the prepreg of the present invention. FIG. 3 is a schematic cross-sectional view showing an embodiment of the metal foil-clad laminate of the present invention. FIG. 4 is a schematic cross-sectional view showing an embodiment of the multilayer printed wiring board of the present invention. It is a schematic cross section for demonstrating 1st Embodiment of the manufacturing method of the multilayer printed wiring board of this invention. It is a schematic cross section for demonstrating 1st Embodiment of the manufacturing method of the multilayer printed wiring board of this invention. It is a schematic cross section for demonstrating 1st Embodiment of the manufacturing method of the multilayer printed wiring board of this invention. It is a schematic cross section for demonstrating 2nd Embodiment of the manufacturing method of the multilayer printed wiring board of this invention. It is a schematic cross section for demonstrating 2nd Embodiment of the manufacturing method of the multilayer printed wiring board of this invention. It is a schematic cross section for demonstrating 2nd Embodiment of the manufacturing method of the multilayer printed wiring board of this invention. It is a schematic cross section for demonstrating 3rd Embodiment of the manufacturing method of the multilayer printed wiring board of this invention.

Explanation of symbols

  3 ... conductive paste, 4, 4a, 4b ... copper foil, 8a, 8b, 18a, 18b, 413a, 413b, 423a, 423b, 424a, 424b, 425a, 425b ... wiring pattern, 28a, 28b ... releasable conductive support Plate: 100: Composite, 101: Fiber sheet, 102: Curable resin composition, 103, 203, 303, 411, 421, 422a, 422b: Through hole, 200: Prepreg, 201: Fiber sheet, 202: Semi-cured Resin composition layer, 300 ... metal foil-clad laminate, 301 ... insulating substrate, 302 ... conductor layer, 304, 412, 422, 422a, 422b ... conductor, 400, 401, 402, 403 ... multilayer printed wiring board, 410, 420a, 420b ... insulating substrate, 420 ... heat-resistant organic sheet, 450 ... printed wiring board for inner layer, 460, 460a, 4 0b ... intermediate connector for the outermost layer 470 ... intermediate connector for the inner layer, 480,480A, 480b ... for the outermost layer printed wiring board.

Claims (13)

A composite comprising a fiber sheet impregnated with a curable resin composition,
The composite whose storage elastic modulus in 20 degreeC of the hardened | cured material of the said curable resin composition is 100-2000 Mpa.   The composite according to claim 1, wherein a ratio Va / Vb of a volume Va of the curable resin composition to a volume Vb of the fiber sheet is 0.3 to 0.9.   The composite_body | complex of Claim 1 or 2 in which the said curable resin composition contains a viscoelastic resin.   The curable resin composition contains an acrylic polymer having a weight average molecular weight of 30000 or more, and the acrylic polymer contains 2 to 20% by mass of glycidyl acrylate as a polymerization component and has an epoxy value of 2 to 36. The complex according to any one of claims 1 to 3.   The composite according to any one of claims 1 to 4, wherein the fiber sheet is a glass cloth having a thickness of 10 to 200 µm.   The composite according to any one of claims 1 to 5, wherein the total thickness of the composite is 100 µm or less.   The complex according to any one of claims 1 to 6, which has a through-hole.   The composite according to any one of claims 1 to 6, wherein the curable resin composition is semi-cured.   The prepreg of Claim 8 which has a through-hole.   8. The composite according to claim 7, wherein the metal foil-clad laminate is obtained by heating and pressurizing the through-hole filled with a conductor and a metal foil disposed on at least one surface of the composite.   The prepreg according to claim 9, wherein the metal foil-clad laminate is obtained by heating and pressing a through-hole filled with a conductor and a metal foil disposed on at least one surface of the prepreg. An insulating substrate laminate including a plurality of insulating substrates each having a through-hole and filled with a conductor in the through-hole, between each of the plurality of insulating substrates, and at least one of the outer surfaces of the insulating substrate laminate A multilayer printed wiring board provided with a wiring pattern connected by the conductor,
The constituent material of the insulating substrate of the outermost layer in which the wiring pattern is disposed on at least both surfaces is a heat resistant organic sheet,
A multilayer printed wiring board, wherein all or part of the insulating substrate other than the outermost layer is made of the composite according to claim 7. A predetermined through hole is formed in an insulating substrate comprising the composite according to any one of claims 1 to 6, a conductor is filled in the through hole, and a metal foil is formed on the surface of the insulating substrate. Laminating and preparing a printed wiring board for inner layer by forming a wiring pattern using the metal foil,
A predetermined through hole is formed in an insulating substrate made of a heat-resistant organic sheet as a constituent material, a conductor is filled in the through hole, a metal foil is laminated on the surface of the insulating substrate, and a wiring pattern is formed using the metal foil. Preparing a printed wiring board for the outermost layer by forming
The outermost layer printed wiring board is arranged so that the outermost layer printed wiring board is arranged in the outermost layer, and the inner layer printed wiring board is arranged in all or a part of the layers other than the outermost layer. Laminating a board and the printed wiring board for inner layer to form a printed wiring board laminate; and
Heating and pressurizing and bonding the printed wiring board laminate, and electrically connecting the wiring pattern using the conductor;
A method for producing a multilayer printed wiring board.

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