JP2006348225A - Composite, prepreg, metallic foil clad laminate and printed wiring substrate using the same, and method for manufacturing printed wiring substrate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite sufficiently excellent in adhesive reliability, sufficiently suppressed in the generation of a resin powder or fiber liable to fall off. <P>SOLUTION: The composite is obtained by impregnating a fibrous sheet with a curable resin composition and has a storage modulus at 20°C of a cured product of the curable resin composition of 100-2,000 MPa. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

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

  In recent years, electronic devices are further required to be smaller and lighter and to have higher functions. For this reason, semiconductors and printed wiring boards that are components of such electronic devices are also required to have higher density and higher functionality.

  For example, in semiconductors, the pitch and the number of pins have been increasingly increased for increasing the degree of integration and higher functionality, and the terminal pitch has been reduced to about 0.3 mm. If the pitch and the number of pins are further increased, it becomes difficult to mount components with the conventional mounting method using solder. Therefore, in the future, COB will be mounted directly on the substrate without using a package. Technology is considered important. Therefore, in recent years, development of COB technology has been studied in various fields.

  On the other hand, a glass-epoxy substrate is most commonly known as a printed wiring board that enables high-density mounting of mounted components. The glass-epoxy substrate is constituted by using a glass woven fabric impregnated with a heat-resistant epoxy resin as an insulating substrate material.

  A glass-epoxy multilayer substrate, which is one of the glass-epoxy substrates, is now widely used for consumer use. However, it cannot necessarily be said that the demand for further higher density as described above is sufficient for the following reasons.

  That is, since a through-hole is formed in a normal glass-epoxy multilayer substrate, when trying to form wiring at a higher density, the through-hole obstructs the wiring space on the substrate, thereby bypassing the wiring. As a result, the wiring length becomes long. In addition, since wiring space is small, automatic wiring by CAD becomes difficult. Furthermore, drilling in forming a smaller diameter through hole becomes difficult, and the cost ratio required for drilling becomes higher than now.

  Also, the electrode layer forming step by copper plating necessary for forming the through hole is not preferable in terms of environmental pollution of the earth. In addition, a component cannot be mounted on the through-hole forming portion. Such a problem is the same for a double-sided substrate configured by electrically connecting the upper surface and the lower surface of a single prepreg through a through hole regardless of the multilayer substrate.

  For such a problem, a printed wiring board having a complete inner via hole (IVH) configuration has been proposed. In the IVH structure, it is possible to connect only necessary layers, and there is no through hole in the uppermost layer of the substrate, and the mountability is excellent.

As a circuit board having this IVH structure, for example, a through hole is formed by laser processing on a sheet substrate material obtained by impregnating a sheet-like organic nonwoven fabric with a thermosetting resin, and this through hole is filled with a conductive paste. And the circuit board which formed the IVH structure by heating-pressing a sheet | seat board | substrate material is proposed (for example, refer patent document 1).
Japanese Patent Application No. 5-77840

  However, the printed wiring board having the IVH structure as described above has a sufficient reliability because a dent may be generated on the board during the manufacture or the wiring may be disconnected. There was no one. In particular, when the thickness of each layer is reduced in order to increase the density, the above-described defects tend to occur frequently.

  Therefore, as a result of examining the cause of the defect in detail, the present inventors, as described above, when the sheet substrate material in which the fiber sheet is impregnated with the resin is used as the insulating substrate, the resin powder or fibers that fall off from the insulating substrate Has been found to be a major cause of the above defects. Further, it has been found that a large amount of resin powder or fiber that falls off is generated particularly when an insulating substrate having a via hole is formed.

  Here, even if the material for the insulating substrate is selected only considering the suppression of the dropping of resin powder or fiber, if the insulating substrate used for the printed circuit board does not have sufficient adhesive reliability, As a result, a 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, a metal foil-clad laminate, a printed wiring board, and a manufacturing method thereof using such a composite.

  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 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 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.

  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 addition, the value calculated | required by the HLC measuring method is employ | adopted for an epoxy value.

  When the weight average molecular weight of the acrylic polymer is less than 30000, the flexibility tends to decrease. 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, it is possible to obtain an insulating substrate that has sufficient mechanical strength and can easily increase the density of the printed wiring board.

  In the composite of the present invention, the total thickness of the composite is preferably 200 μm or less. When the total thickness of the composite is 200 μm or less, it is easier to increase the density when used as an insulating substrate constituting the printed wiring board.

  Furthermore, in the composite of the present invention, the composite preferably has a through hole. According to such a composite, the step of forming the through-hole can be omitted by providing the through-hole in advance at a predetermined position. By using such a composite, a printed wiring board having an IVH structure excellent in reliability can be obtained. It can be manufactured with good 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 printed wiring board which has IVH structure using the prepreg of this invention, the 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 by providing the through-hole in a predetermined position in advance, and by using such a prepreg, a printed wiring board having an excellent IVH structure can be more easily obtained. Can be manufactured.

  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 printed wiring board which has IVH structure using the metal foil tension laminated board of this invention, the 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 printed wiring board which has IVH structure using the metal foil tension laminated board of this invention, the printed wiring board excellent in reliability can be obtained with a sufficient yield.

The 1st printed wiring board of this invention forms the composite resin composition layer which consists of a composite_body | complex of any one of Claims 1-6 on both surfaces of the organic nonwoven fabric material of density 0.8g / cm < ³ > or more. Through-holes are formed in the thickness direction of the sheet substrate formed, and the through-holes are filled with a conductive resin composition, and at least a part of the through-holes on both sides of the sheet substrate is electrically connected to the conductive resin composition. A wiring pattern connected to is formed.

Moreover, the 2nd printed wiring board of this invention is a composite resin composition layer which consists of a composite_body | complex of any one of Claims 1-6 on both surfaces of the organic nonwoven fabric material of density 0.8g / cm < ³ > or more. 2 or more sheet substrates formed by forming two or more electrode layers, through holes are formed in the thickness direction of the sheet substrate, the through holes are filled with a conductive resin composition, It has a multilayer wiring structure in which electrode layers are electrically connected.

  In the configuration of the conventional printed wiring board described above, the adhesion between the board material and the copper foil is poor, and when mounting a component on the printed wiring board by soldering, the mounting strength cannot be kept high. There is a problem.

  In addition, an impregnating resin (thermosetting resin) of the substrate material flows between the conductive resin paste and the copper foil, which becomes a barrier and causes a connection failure, or further due to thermal shock such as during solder reflow due to this barrier. There is a problem that breakage occurs at the interface between the conductive paste and the copper foil, resulting in poor conduction.

  Further, it is generally considered that a substrate material using a nonwoven fabric as a reinforcing material has a large substrate warp. This is because the non-woven fabric, which is a reinforcing material, is obtained by paper-cutting short cut fibers like paper, making it difficult to control the fiber orientation (fiber orientation) and tend to result in partially uneven fiber orientation. Because. As a result, the physical properties of the base material, that is, the anisotropy such as the thermal expansion coefficient and the elastic modulus, is generated by the fiber orientation. .

In response to these problems, according to the first and second printed wiring boards of the present invention, the above-described composite resin composition layer comprising the composite of the present invention is made of an organic nonwoven fabric material having a density of 0.8 g / cm ³ or more. By using the sheet substrate formed on both sides, the wiring pattern is not affected by the organic nonwoven fabric material in the substrate, and is firmly adhered to the composite resin composition layer, and the wiring pattern and the conductive resin composition are Are stably connected electrically and mechanically, and a highly reliable printed wiring board can be realized. In addition, by using densely compressed substrate material made of organic nonwoven fabric as a reinforcing material, the anisotropy of elastic modulus within the nonwoven fabric surface is eliminated, and a substrate with less substrate warpage and twisting can be realized. it can.

  Here, in the first and second printed wiring boards of the present invention, the organic nonwoven fabric material is preferably a heat-resistant synthetic fiber from the viewpoint of improving heat resistance. The heat-resistant synthetic fiber is preferably a wholly aromatic polyamide, whereby particularly excellent heat resistance can be obtained.

  In the printed wiring board of the present invention, the conductive resin composition preferably contains fine metal particles made of at least one metal selected from gold, silver, palladium, copper, nickel, tin and lead. . Thereby, the contact resistance of a conductive resin composition and a wiring pattern becomes small, and the electronic conductivity between both can be secured at a high level. Furthermore, it is preferable that the content of the metal fine particles is 80 to 92.5% by mass based on the total amount of the conductive resin composition. Thereby, the contact resistance of a conductive resin composition and a wiring pattern becomes smaller, and the electronic conductivity between both can be secured at a higher level.

The 1st manufacturing method of the printed wiring board of this invention consists of the composite of the said invention on both surfaces of the organic nonwoven fabric material of density 0.8g / cm < ³ > or more, and curable resin composition is an uncured state. A step of preparing a sheet substrate in which a composite resin composition layer is formed; a step of attaching a cover film to both surfaces of the sheet substrate to obtain a sheet substrate material; and a through hole in the thickness direction of the sheet substrate material Forming and filling the through-hole with a conductive resin paste, removing the cover film to obtain an intermediate substrate body, and heating and pressing in a state where metal foils are arranged on both surfaces of the intermediate substrate body, A step of bonding the metal foil to the composite resin composition layer by curing the curable resin composition in the composite resin composition layer, and a step of patterning the metal foil into a predetermined pattern. It is characterized by.

  According to this manufacturing method, the above-described highly reliable printed wiring board of the present invention can be efficiently manufactured.

Moreover, the 2nd manufacturing method of the printed wiring board of this invention consists of the composite_body | complex of the said this invention on both surfaces of the organic nonwoven fabric material of density 0.8g / cm < ³ > or more, and curable resin composition is a non-hardened state A step of preparing a sheet substrate formed with a composite resin composition layer, a step of obtaining a sheet substrate material by attaching cover films on both sides of the sheet substrate, and a penetration in the thickness direction of the sheet substrate material Forming a hole and filling the through-hole with a conductive resin paste; then, removing the cover film to obtain an intermediate substrate body; and preparing two intermediate substrate bodies. After sandwiching a circuit board having at least two wiring patterns in between, a metal foil is disposed on the outside of the circuit board, and the whole is heated and pressed to form a curable resin composition in the composite resin composition layer. Harden And a step of patterning the metal foil into a predetermined pattern.

  According to this manufacturing method, the second printed wiring board having the above-described highly reliable multilayer wiring structure of the present invention can be efficiently manufactured.

Furthermore, the 3rd manufacturing method of the printed wiring board of this invention consists of a composite of the said invention on both surfaces of the organic nonwoven fabric material of density 0.8g / cm < ³ > or more, and curable resin composition is a non-hardened state A step of preparing a sheet substrate formed with a composite resin composition layer, a step of obtaining a sheet substrate material by attaching cover films on both sides of the sheet substrate, and a penetration in the thickness direction of the sheet substrate material Forming a hole, filling the through hole with a conductive resin paste, and then removing the cover film to obtain an intermediate substrate body, and between the two or more double-sided printed wiring boards, the intermediate substrate body And integrally bonding the plurality of double-sided printed wiring boards via the intermediate substrate body by curing the curable resin composition in the composite resin composition layer by heating and pressurizing the whole. And It is characterized by having.

  According to this manufacturing method, the second printed wiring board having the above-described highly reliable multilayer wiring structure of the present invention can be efficiently manufactured.

  In addition, in the said 1st-3rd manufacturing method, that a curable resin composition is an "uncured state" includes a semi-hardened state (B stage state). Moreover, the curing start temperature of the curable resin composition can be appropriately changed depending on the type or content of the catalyst (curing agent, reaction accelerator) for the multi-functional low molecular compound or the initial condensation reaction intermediate.

  Moreover, in the said 1st-3rd manufacturing method, it is preferable that the thickness of the composite resin composition layer of an unhardened state is the range of 50-300 micrometers in total of both surfaces. This reliably prevents the organic nonwoven fabric material in the base material from intervening at the boundary with the metal foil during heating and pressurization, and has excellent adhesion with the metal foil, high production efficiency, and the above-described reliability. A high printed wiring board can be manufactured. Moreover, the thickness of the substrate can be arbitrarily controlled.

Moreover, in the said 1st-3rd manufacturing method, it is preferable that the heating temperature at the time of heating-pressing is the range of 120-260 degreeC. Thereby, hardening of curable resin composition can be completed effectively. Furthermore, it is preferable that the applied pressure at the time of heating and pressurizing is in the range of 10 to 80 kg / cm ² . As a result, the adhesive force between the metal foil and the composite resin composition layer and between the metal foil and the conductive resin composition can be reliably increased, and the above-described highly reliable printed wiring can be manufactured efficiently. A board can be manufactured. Moreover, the air hole in a sheet-like base material can fully be reduced, and a board | substrate characteristic can be improved.

  Moreover, in the said 1st-3rd manufacturing method, it is preferable that the said conductive resin paste contains the curable resin composition substantially the same as the curable resin composition in the said composite_body | complex.

  Furthermore, in the said 1st-3rd manufacturing method, it is preferable that the said organic nonwoven fabric material is a heat resistant synthetic fiber from a viewpoint of improving heat resistance. The heat-resistant synthetic fiber is preferably a wholly aromatic polyamide, whereby particularly excellent heat resistance can be obtained.

  In the first to third manufacturing methods, the conductive resin paste contains fine metal particles made of at least one metal selected from gold, silver, palladium, copper, nickel, tin, and lead. Is preferred. Thereby, the contact resistance between the conductive resin paste and the metal foil is reduced, and the electronic conductivity between them can be ensured at a high level. Furthermore, the content of the metal fine particles is preferably 80 to 92.5% by mass based on the total amount of the conductive resin paste. Thereby, the contact resistance between the conductive resin paste and the metal foil becomes smaller, and the electronic conductivity between them can be secured at a higher level.

  In the first to third manufacturing methods, the through hole is preferably processed by at least one method selected from drilling, carbon dioxide laser, YAG laser, and excimer laser. Thereby, high-density formation corresponding to the refinement | miniaturization and narrow pitch of a through-hole can be performed efficiently.

  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. In addition, according to the present invention, the wiring pattern is firmly adhered to the composite resin composition layer, the wiring pattern and the conductive resin composition are electrically and mechanically stably connected, and there is little substrate warpage and twisting. A highly reliable printed wiring board can be provided. Furthermore, according to this invention, the manufacturing method of the printed wiring board which can manufacture the printed wiring board of the said invention efficiently can be provided.

  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 curable resin composition 102 into a fiber sheet 101. 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 20 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.

  Moreover, the curable resin composition 102 can contain a predetermined solvent. Solvents 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. 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, butanol , Alcohol solvents such as isopropanol; ether alcohol solvents such as 2-methoxyethanol and 2-butoxyethanol can be used, and one or more of these can be used. It is possible.

  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.

  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 50%. When the curing rate of the curable resin composition is less than 10%, when integrated with the metal foil, the unevenness of the fiber sheet is reflected on the surface of the integrated metal foil, and the surface smoothness tends to be reduced. The control of the thickness of the insulating substrate tends to be difficult. On the other hand, if the curing rate of the curable resin composition exceeds 50%, the resin component is insufficient when it is integrated with the metal foil, and if it is integrated at a high speed, bubbles and blurring are likely to occur, and adhesion with the metal foil. Power 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 a press lamination method from the viewpoint of efficiently forming the conductor layer 302. 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 260 ° C., a pressure of 10 to 80 kg / cm ² , and a heating time of 30 to 120 minutes. A range condition is mentioned.

  Further, before continuously laminating the metal foil and the prepreg or the composite, the same photosensitive resin composition as that contained in the prepreg or the composite is applied to the surface of the metal foil, and the resin composition It is preferable to form a layer. Thereby, it can further reduce that the unevenness | corrugation of the surface of the fiber sheet contained in a prepreg or a composite_body | complex is reflected in the surface of a conductor layer.

  Next, preferred embodiments of the printed wiring board and the manufacturing method thereof according to the present invention will be described.

4A to 4F are a series of process diagrams showing a first embodiment of a method for manufacturing a printed wiring board according to the present invention. First, as shown in FIG. 4 (a), an uncured composite resin composition layer 2 made of the prepreg of the present invention described above is laminated on both surfaces of an organic nonwoven fabric 1 having a density of 0.8 g / cm ³ or more. A sheet substrate 3 is prepared.

Here, as the organic nonwoven fabric 1, for example, aromatic polyamide (aramid) fiber (specifically, for example, Kevlar fiber manufactured by DuPont, fineness: 1.5 denier, length: 6.7 mm, basis weight: 72 g) / M ² , density: 0.5 g / cm ³ ), etc., and one that has been calendered at a high temperature so as to obtain a density of 0.8 g / cm ³ or higher by using an ultra-high pressure calender device is used. be able to. Moreover, it is preferable that the thickness of the organic nonwoven fabric 1 is 50-150 micrometers. In addition, as the organic nonwoven fabric 1, you may use heat resistant synthetic fibers other than the said aromatic polyamide fiber.

In addition, as the organic nonwoven fabric 1, it is necessary to use a thing of 0.8 g / cm ³ or more. For example, at a density of 0.5 to 0.7 g / cm ³ , the elastic modulus is about 50 kg / mm ^2. As a result, only a substrate having a large warp and twist can be obtained. Further, 100 Kg ^/ mm 2 at ^{0.75g / cm 3, 0.8g / cm} 3 or more at 200 Kg / mm ² in elastic modulus is obtained by at 0.8 g / cm ³ or more, warpage, without kinks A good substrate can be obtained.

  Next, as shown in FIG. 4B, the cover film 4 such as a polyethylene terephthalate film is placed on the surface of the composite resin composition layer 2 from the curing start temperature of the curable resin composition in the composite resin composition layer 2. Is laminated by heating and pressing at a low temperature to obtain a sheet substrate material 5.

  Next, as shown in FIG. 4C, a hole diameter of 50 to 200 μm is applied to a predetermined portion of the sheet substrate material 5 by, for example, a laser processing method using a carbon dioxide gas laser, an excimer laser, a YAG laser, or a drill processing method. The through hole 6 is formed, and the through hole 6 is filled with the conductive resin paste 7.

  Here, the conductive resin paste 7 can be obtained by kneading the conductive material and the curable resin composition with three rolls or the like. As the conductive material, metal fine particles made of at least one metal selected from gold, silver, palladium, copper, nickel, tin and lead are preferable. The average particle diameter of the metal fine particles is preferably 1 to 5 μm. Moreover, as a curable resin composition, the thing similar to the curable resin composition used for the composite_body | complex of this invention mentioned above is used.

  The content of the conductive substance in the conductive resin paste 7 is preferably 80 to 92.5% by mass based on the total amount of the conductive resin paste 7.

  As a method of filling the through hole 6 with the conductive resin paste 7, a sheet substrate material having the through hole 6 is placed on a table of a printing machine (not shown), and the conductive resin paste 7 is directly applied to the cover film 4. The method of printing from the top is mentioned. As a printing method, for example, roll transfer printing can be used. At this time, the cover film 6 on the upper surface plays a role of a printing mask and a role of preventing contamination of the surface of the composite resin composition layer 2.

  Next, as shown in FIG. 4 (d), after peeling the cover film 4 from the surface of the composite resin composition layer 2, a metal foil 8 is disposed outside the composite resin composition layer 2, and arrows A and B Heat and press in the direction of.

  Here, as the metal foil 8, for example, a copper foil or the like is used, and the thickness is preferably 12 to 35 μm.

The heating and pressurization is performed by applying a predetermined pressure at a temperature at which the curable resin composition in the composite resin composition layer 2 and the conductive resin paste 7 is cured (for example, 60 kgf / cm ^{2 in} vacuum). The temperature was raised from room temperature to 180 ° C. in 30 minutes and held at 180 ° C. for 60 minutes, and then lowered to room temperature in 30 minutes), whereby the aromatic polyamide (aramid) constituting the organic nonwoven fabric 1 The metal foil 8 can be firmly bonded to the composite resin composition layer 2 without being affected by the fibers.

  And by performing said heat pressurization, as shown in FIG.4 (e), the curable resin composition in the composite resin composition layer 2 is hardened, and the metal foil 8 is made into the composite resin composition layer 12. FIG. Adhere.

  Further, the curable resin composition in the conductive resin paste 7 is also cured to form the conductive resin paste 17, and at this time, the bond between the conductive substances in the conductive resin paste becomes strong.

  Moreover, the pores in the organic nonwoven fabric 1 can be sufficiently reduced to, for example, about 0 to 1% by volume (based on the total volume of the organic nonwoven fabric 1) by heating and pressurizing, and the shape of the pores can be reduced. it can. Further, the curable resin composition of the conductive resin paste 7 that has penetrated into the sheet substrate 3 is cured, whereby the interface between the conductive resin paste 7 and the sheet substrate 3 can be firmly bonded.

  Thereafter, as shown in FIG. 4 (f), the metal foil 8 is etched to form the circuit pattern 18, thereby obtaining the double-sided printed wiring board 10.

  According to the manufacturing method described above, the substrate has an IVH structure, the wiring pattern is firmly adhered to the composite resin composition layer, and the wiring pattern and the conductive resin paste are stably connected electrically and mechanically. A highly reliable double-sided printed wiring board with less warping and twisting can be obtained.

  Next, a second embodiment of the method for manufacturing a printed wiring board of the present invention will be described. FIGS. 5A to 5B are a series of process diagrams showing a second embodiment of the method for manufacturing a printed wiring board of the present invention. In the method for manufacturing a printed wiring board according to the second embodiment, a multilayer printed wiring board is produced using the double-sided printed wiring board shown in the first embodiment.

  First, while preparing the double-sided printed wiring board 10 shown in the said 1st Embodiment, the intermediate board body which peeled the cover film 4 of the state shown in FIG.4 (d) from the sheet | seat board | substrate 3 in the said 1st Embodiment. prepare. These can be manufactured according to the method shown in the first embodiment. And as shown to Fig.5 (a), the intermediate board body 20 is arrange | positioned on both surfaces of the double-sided printed wiring board 10, and the metal foil 8 is further arrange | positioned on the outer side. In this state, the whole is integrally joined by heating and pressing in the directions of arrows A and B.

  By this heating and pressurization, the uncured composite resin composition layer 2 in the intermediate substrate body 20 and the curable resin composition in the conductive resin paste 7 are cured, and the whole is bonded.

  Thereafter, the metal foil 8 is etched by a normal pattern forming method to form a circuit pattern 18. Thereby, a four-layer multilayer printed wiring board as shown in FIG. 5B can be obtained.

  According to the manufacturing method described above, the substrate has an IVH structure, the wiring pattern is firmly adhered to the composite resin composition layer, and the wiring pattern and the conductive resin paste are stably connected electrically and mechanically. A highly reliable multilayer printed wiring board with less warping and twisting can be obtained.

  In the manufacturing method according to the second embodiment described above, a four-layer printed wiring board is manufactured. However, in the case of a higher multilayer, the double-sided printed wiring board 10 in FIG. By replacing the multilayer printed wiring board of (b) and further laminating, a multilayer printed wiring board having 6 or more layers can be obtained.

  Next, a third embodiment of the method for manufacturing a printed wiring board of the present invention will be described. 6A to 6B are a series of process diagrams showing a third embodiment of the method for manufacturing a printed wiring board of the present invention. In the method for manufacturing a printed wiring board according to the third embodiment, a multilayer printed wiring board is produced using the double-sided printed wiring board and the intermediate board body shown in the second embodiment.

  First, while preparing three double-sided printed wiring boards 10 shown in the first embodiment, an intermediate board in which the cover film 4 in the state shown in FIG. Prepare two bodies. These can be manufactured according to the method shown in the first embodiment. And as shown to Fig.6 (a), the double-sided printed wiring board 10 and the intermediate board body 20 are arrange | positioned alternately. In this state, the whole is integrally joined by heating and pressing in the directions of arrows A and B.

  By this heating and pressurization, the uncured composite resin composition layer 2 in the intermediate substrate body 20 and the curable resin composition in the conductive resin paste 7 are cured, and the whole is bonded. As a result, a six-layer multilayer printed wiring board as shown in FIG. 6B can be obtained.

  According to the manufacturing method described above, the substrate has an IVH structure, the wiring pattern is firmly adhered to the composite resin composition layer, and the wiring pattern and the conductive resin paste are stably connected electrically and mechanically. A highly reliable multilayer printed wiring board with less warping and twisting can be obtained.

  Moreover, according to the manufacturing method according to the third embodiment, a printed wiring board having a larger number of wiring layers can be manufactured at once by replacing the double-sided printed wiring board to be used with, for example, a four-layer printed wiring board. It becomes possible. Further, depending on the lamination conditions, it is possible to embed the outermost wiring pattern in the composite resin composition layer by heating and pressurization, thereby obtaining a multilayer printed wiring board having a smooth outermost surface. .

  The printed wiring board of the present invention is manufactured by the method for manufacturing a printed wiring board of the present invention described above. For example, as shown in FIG. 4 (f), FIG. 5 (b) or FIG. 6 (b). It has the structure.

Such a printed wiring board of the present invention has through-holes in the thickness direction of the sheet substrate in which the composite resin composition layer composed of the composite of the present invention is formed on both surfaces of an organic nonwoven fabric material having a density of 0.8 g / cm ³ or more. The conductive resin composition is filled in the through hole, and a wiring pattern is formed on both surfaces of the sheet substrate, at least a part of which is electrically connected to the conductive resin composition. As a result, the adhesion between the composite resin composition layer and the wiring pattern is improved, and the wiring pattern and the conductive resin composition (conductive paste) are well connected electrically and mechanically. It becomes. As a result, a highly reliable printed wiring board having excellent durability and electrical characteristics can be realized. In addition, by adopting a high-density organic nonwoven fabric, a printed wiring board with small board warpage and twist can be realized.

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. (A)-(f) is a series of process drawings which show 1st Embodiment of the manufacturing method of the printed wiring board of this invention. (A)-(b) is a series of process drawings which show 2nd Embodiment of the manufacturing method of the printed wiring board of this invention. (A)-(b) is a series of process drawings which shows 3rd Embodiment of the manufacturing method of the printed wiring board of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Composite, 101 ... Fiber sheet, 102 ... Curable resin composition, 103, 203, 303 ... Through-hole, 200 ... Pre-preg, 201 ... Fiber sheet, 202 ... Semi-cured resin composition layer, 300 ... Metal foil tension Laminated plate, 301 ... insulating substrate, 302 ... conductor layer, 304 ... conductive portion.

Claims (15)

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 the 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 claim 1 or 2.   The composite according to any one of claims 1 to 3, wherein the fiber sheet is a glass cloth having a thickness of 10 to 200 µm.   The composite_body | complex of any one of Claims 1-4 whose total thickness of a composite_body | complex is 200 micrometers or less.   The composite according to any one of claims 1 to 5, which has a through-hole.   The composite according to any one of claims 1 to 5, wherein the curable resin composition is semi-cured.   The prepreg of Claim 7 which has a through-hole.   The metal foil-clad laminate obtained by heating and pressurizing the composite according to claim 6, wherein the through-hole is filled with a conductor and a metal foil is disposed on at least one surface of the composite.   The prepreg according to claim 8, 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. It penetrates in the thickness direction of the sheet | seat board | substrate with which the composite resin composition layer which consists of a composite of any one of Claims 1-5 is formed in both surfaces of the organic nonwoven fabric material of density 0.8g / cm < ³ > or more. A hole is formed, the conductive resin composition is filled in the through hole, and a wiring pattern is formed on both surfaces of the sheet substrate, at least a part of which is electrically connected to the conductive resin composition. Printed wiring board. Two or more sheet substrates in which a composite resin composition layer comprising the composite according to any one of claims 1 to 5 is formed on both surfaces of an organic nonwoven fabric having a density of 0.8 g / cm ³ or more; A multilayer wiring structure comprising the above electrode layers, wherein through-holes are formed in the thickness direction of the sheet substrate, the through-holes are filled with a conductive resin composition, and the electrode layers are electrically connected. A printed wiring board. A composite resin composition comprising the composite according to any one of claims 1 to 5 on both sides of an organic nonwoven fabric having a density of 0.8 g / cm ³ or more, wherein the curable resin composition is in an uncured state. Preparing a sheet substrate on which a layer is formed;
A step of attaching a cover film to both sides of the sheet substrate to obtain a sheet substrate material;
Forming a through hole in the thickness direction of the sheet substrate material, filling the through hole with a conductive resin paste, and then removing the cover film to obtain an intermediate substrate body; and
A process of bonding the metal foil to the composite resin composition layer by heating and pressurizing the metal foil on both surfaces of the intermediate substrate body and curing the curable resin composition in the composite resin composition layer. When,
Patterning the metal foil into a predetermined pattern;
A method for manufacturing a printed wiring board, comprising: A composite resin composition comprising the composite according to any one of claims 1 to 5 on both sides of an organic nonwoven fabric having a density of 0.8 g / cm ³ or more, wherein the curable resin composition is in an uncured state. Preparing a sheet substrate on which a layer is formed;
A step of attaching a cover film to both sides of the sheet substrate to obtain a sheet substrate material;
Forming a through hole in the thickness direction of the sheet substrate material, filling the through hole with a conductive resin paste, and then removing the cover film to obtain an intermediate substrate body; and
Two intermediate substrate bodies are prepared, and a circuit board having at least two layers of wiring patterns is sandwiched between the two intermediate substrate bodies, and then the whole is heated in a state where metal foils are respectively arranged on the outside. A step of applying pressure to cure the curable resin composition in the composite resin composition layer;
Patterning the metal foil into a predetermined pattern;
A method for manufacturing a printed wiring board, comprising: A composite resin composition comprising the composite according to any one of claims 1 to 5 on both sides of an organic nonwoven fabric having a density of 0.8 g / cm ³ or more, wherein the curable resin composition is in an uncured state. Preparing a sheet substrate on which a layer is formed;
A step of attaching a cover film to both sides of the sheet substrate to obtain a sheet substrate material;
Forming a through hole in the thickness direction of the sheet substrate material, filling the through hole with a conductive resin paste, and then removing the cover film to obtain an intermediate substrate body; and
By placing the intermediate substrate body between each of two or more double-sided printed wiring boards and heating and pressurizing the whole to cure the curable resin composition in the composite resin composition layer, A step of integrally bonding a printed wiring board via the intermediate substrate body;
A method for manufacturing a printed wiring board, comprising:

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