JP2019065072A - Adhesive sheet with metallic foil, and wiring board - Google Patents

Abstract

To provide an adhesive sheet with metallic foil capable of providing a printed wiring board which is low in a coefficient of thermal expansion, is excellent in coating property, adhesion, insulating property and heat resistance, and is excellent in insulation reliability, and to provide a wiring board using the adhesive sheet with the metallic foil.SOLUTION: An adhesive sheet with metallic foil has a metallic foil and an adhesive layer provided on the metallic foil. The adhesive layer is composed of (A) a thermosetting resin containing a solid epoxy resin having a naphthalene skeleton and a liquid epoxy resin having a naphthalene skeleton, (B) an amine curing agent, (C) a phenoxy resin having a weight average molecular weight of 30,000-150,000, and (D) an inorganic filler, and contains 50-200 pts.mass of (C) the phenoxy resin and 200-1,000 pts.mass of (D) the inorganic filler based on 100 pts.mass of (A) the thermosetting resin.SELECTED DRAWING: None

Description

  The present invention relates to an adhesive sheet with metal foil and a wiring board using the adhesive sheet with metal foil.

  With the reduction in size and weight of electronic devices, the density of substrates has been increased. Along with this, adoption of build-up substrates capable of higher density is also increasing. In order to further reduce the thickness of build-up substrates and to increase the efficiency of laser processing, in which insulating layers and conductive layers are repeatedly laminated, in place of conventional fiber substrates, investigation of substrates using films as substrates is also promoted. (E.g., Patent Document 1). However, the epoxy resin widely used for printed wiring boards has a large thermal expansion, and peeling and the like occur due to the thermal expansion difference with the insulating layer, which often causes a serious problem of lowering the reliability. Moreover, it also becomes a cause of board | substrate curvature in a buildup board | substrate. As a means for solving this, there has been proposed a method of using an inorganic insulating layer containing silica as a main component in accordance with the adhesive sheet with metal foil (for example, Patent Document 2). According to this method, low thermal expansion is developed to improve the reliability and the substrate warpage characteristics.

JP 2015-3982 A JP 2012-79972 A

  As semiconductor packages have become more sophisticated and miniaturized, multi-layering is further promoted, and at the same time, the thickness per layer is reduced, and higher mechanical properties and reliability are required. For example, in the case of an adhesive sheet as described in Patent Document 1, there are problems such as a decrease in film property and a decrease in adhesion to a metal foil when it is intended to be thin. In addition, for example, there is a problem that the reliability is reduced if the buildup substrate described in Patent Document 2 is to be thinned.

  The present invention has been made in view of the above circumstances, and is a metal that can provide a printed wiring board having a low coefficient of thermal expansion, excellent coating property, adhesion, insulation, and heat resistance, and excellent insulation reliability. An object of the present invention is to provide a foil-attached adhesive sheet and a wiring board using the metal foil-attached adhesive sheet.

The present inventors diligently studied on a metal foil-attached adhesive sheet having high reliability. As a result, the resin composition forming the adhesive layer of the adhesive sheet with metal foil is a thermosetting resin in which solid and liquid epoxy resins having a naphthalene skeleton are used in combination, an amine curing agent, weight average molecular weight 30,000 to 150 It has been found that the present invention is achieved by the fact that it is excellent in the balance of various properties such as fine wiring processability and insulation reliability by containing 1,000, 000 phenoxy resins and an inorganic filler.
The present invention has been completed based on such findings.

That is, the present invention provides the following [1] to [6].
[1] A thermosetting resin comprising: a metal foil; and an adhesive layer provided on the metal foil, wherein the adhesive layer includes (A) a solid epoxy resin having a naphthalene skeleton and a liquid epoxy resin having a naphthalene skeleton. (A) thermosetting resin, comprising a resin composition containing (B) an amine-based curing agent, (C) a phenoxy resin having a weight average molecular weight of 30,000 to 150,000, and (D) an inorganic filler An adhesive sheet with metal foil comprising 50 to 200 parts by mass of (C) phenoxy resin and 200 to 1000 parts by mass of (D) inorganic filler with respect to 100 parts by mass of resin.
[2] The metal foil-attached adhesive sheet according to the above [1], wherein the (D) inorganic filler contains silica and hydrotalcite.
[3] The adhesive sheet with metal foil as described in the above [1] or [2], wherein an insulating layer mainly composed of silica powder is interposed between the metal foil and the adhesive layer.
[4] A primer layer is further interposed between the metal foil and the insulating layer, and the total thickness of the adhesive layer, the insulating layer, and the primer layer is 15 μm or less. Adhesive sheet with metal foil as described in.
[5] The adhesive sheet with metal foil as set forth in [3] or [4], wherein the insulating layer is made of the amorphous silica powder.
[6] A wiring board using the adhesive sheet with metal foil according to any one of the above [1] to [5].

  According to the present invention, a metal foil-attached adhesive sheet capable of providing a printed wiring board having a low thermal expansion coefficient, excellent in coating property, adhesion, insulation and heat resistance and excellent in insulation reliability, the metal foil A wiring board using a laminated adhesive sheet can be provided.

It is a schematic sectional drawing of the adhesive sheet with metal foil which shows an example of embodiment of this invention. It is a schematic sectional drawing of the adhesive sheet with metal foil which shows an example of embodiment of this invention. It is a schematic sectional drawing of the adhesive sheet with metal foil which shows an example of embodiment of this invention.

Hereinafter, the present invention will be described in detail.
[Adhesive sheet with metal foil]
The adhesive sheet with metal foil of the present invention comprises a metal foil and an adhesive layer provided on the metal foil, and the adhesive layer comprises (A) a solid epoxy resin having a naphthalene skeleton and a liquid having a naphthalene skeleton. Thermosetting resin containing epoxy resin (hereinafter, also referred to simply as thermosetting resin), (B) amine curing agent, (C) phenoxy resin having a weight average molecular weight of 30,000 to 150,000 (hereinafter, simply phenoxy resin It consists of a resin composition containing a resin and (D) inorganic filler, and 50 to 200 parts by mass of (C) phenoxy resin with respect to 100 parts by mass of the (A) thermosetting resin, (D) inorganic It is characterized by containing 200-1000 mass parts of fillers.

  1 to 3 are schematic cross-sectional views showing an embodiment of a metal foil-attached adhesive sheet of the present invention. An adhesive sheet 10 with metal foil in FIG. 1 includes a metal foil 1 and an adhesive layer 2 provided on the metal foil. Further, in the adhesive sheet with metal foil of the present invention, as shown in FIG. 2, the insulating layer 13 may be provided between the metal foil 11 and the adhesive layer 12, as shown in FIG. 3, A primer layer 24 may be provided between the metal foil 21 and the insulating layer 23.

(Adhesive layer)
The adhesive layer in the metal foil-attached adhesive sheet of the present invention comprises (A) a thermosetting resin containing a solid epoxy resin having a naphthalene skeleton and a liquid epoxy resin having a naphthalene skeleton, (B) an amine curing agent, (C 2.) A layer comprising a resin composition containing a phenoxy resin having a weight average molecular weight of 30,000 to 150,000 and (D) an inorganic filler.

[(A) Thermosetting resin containing solid epoxy resin having naphthalene skeleton and liquid epoxy resin having naphthalene skeleton]
The thermosetting resin of component (A) contains a solid epoxy resin having a naphthalene skeleton and a liquid epoxy resin having a naphthalene skeleton. Thereby, a film having a low thermal expansion coefficient and high heat resistance can be formed.

The solid epoxy resin having a naphthalene skeleton is not particularly limited as long as it has a naphthalene skeleton and two or more epoxy groups in one molecule and is solid at normal temperature (25 ° C.) Can.
The softening point of the solid epoxy resin having a naphthalene skeleton is preferably 50 to 100 ° C., more preferably 70 to 90 ° C. Further, the epoxy equivalent of the solid epoxy resin having a naphthalene skeleton is preferably 100 to 1000, more preferably 200 to 500.

  Examples of solid epoxy resins having a naphthalene skeleton include naphthalene type tetrafunctional epoxy resins ("HP 4700" and "HP 4710" manufactured by DIC Corporation), naphthalene type epoxy resins ("HP 6000" manufactured by DIC Corporation), etc. Be One of these may be used, or two or more may be used in combination.

  The liquid epoxy resin having a naphthalene skeleton is not particularly limited as long as it has a naphthalene skeleton and two or more epoxy groups in one molecule and is liquid at normal temperature (25 ° C.) it can. The epoxy equivalent of the liquid epoxy resin having a naphthalene skeleton is preferably 50 to 500, more preferably 100 to 300.

  Examples of liquid epoxy resins having a naphthalene skeleton include naphthalene type bifunctional epoxy resins ("HP4032" and "HP4032D" manufactured by DIC Corporation), etc. One of these may be used, or two or more of them may be used. May be used in combination.

The component (A) thermosetting resin may contain an epoxy resin other than the solid epoxy resin having a naphthalene skeleton and the liquid epoxy resin having a naphthalene skeleton within the range not impairing the effects of the present invention. As such an epoxy resin, a naphthol type epoxy resin, a naphthalene arakir type epoxy resin, a naphthalene frame modified polyfunctional epoxy resin etc. are mentioned, for example. Moreover, as a naphthol type epoxy resin, "SN-475" etc. made from Nippon Steel Chemical Co., Ltd. can be obtained as a commercial item.
When a solid epoxy resin having a naphthalene skeleton and an epoxy resin other than a liquid epoxy resin having a naphthalene skeleton are used in combination, the amount thereof is 30 parts by mass or less based on 100 parts by mass of the thermosetting resin of component (A). It is preferable to do it, it is more preferable to set it as 20 mass parts or less, and it is more preferable to set it as 10 mass parts or less.

  The upper limit value of the content of the solid epoxy resin having a naphthalene skeleton and the liquid epoxy resin having a naphthalene skeleton contained in the resin composition is 100% by mass of nonvolatile components in the resin composition from the viewpoint of improving the mechanical properties. In the case, 40 mass% or less is preferable, 30 mass% or less is more preferable, and 20 mass% or less is more preferable. On the other hand, the lower limit value of the content of the solid epoxy resin having a naphthalene skeleton and the liquid epoxy resin having a naphthalene skeleton is 100% by mass of nonvolatile components in the resin composition from the viewpoint of heat resistance improvement and adhesion improvement with metal foil. When it is%, 1 mass% or more is preferable, 3 mass% or more is more preferable, and 5 mass% or more is still more preferable.

  The mixing ratio (solid: liquid) of the solid epoxy resin having a naphthalene skeleton and the liquid epoxy resin having a naphthalene skeleton is preferably in the range of 1: 0.1 to 1: 0.8 by mass ratio, 1: 0.2 The range of about 1: 0.7 is more preferable. If the proportion of the liquid epoxy resin having a naphthalene skeleton is too large beyond this range, the adhesiveness of the resin composition becomes high, and when used in the form of an adhesive sheet, the degassing property at the time of vacuum lamination decreases and voids It tends to occur easily. In addition, the peelability of the protective film or the support film tends to decrease during vacuum lamination, and the heat resistance after curing tends to decrease. Moreover, in the hardened | cured material of a resin composition, it exists in the tendency for it to be hard to obtain sufficient breaking strength. On the other hand, if the proportion of the solid epoxy resin having a naphthalene skeleton is too large beyond this range, sufficient flexibility can not be obtained when used in the form of an adhesive sheet, and the handleability is reduced, and laminating There is a tendency that it is difficult to obtain sufficient liquidity at the time of

  In the resin composition, when the nonvolatile component in the resin composition is 100% by mass, the content of the component (A) thermosetting resin is preferably 10 to 50% by mass, more preferably 25 to 45% by mass, More preferably, it is 20-42 mass%. When the content of the component (A) thermosetting resin is within the above range, the curability of the resin composition can be enhanced.

[(B) amine curing agent]
In the present invention, the amine curing agent of component (B) is used as a curing agent of the thermosetting resin of component (A). Examples of the amine-based curing agent of component (B) include dicyandiamide, aliphatic amine compounds, and aromatic amine compounds. Among them, dicyandiamide and an aromatic amine compound are preferable, and as the aromatic amine compound, an aromatic amine compound having at least two primary amino groups in one molecule is preferably used. Examples of the aromatic amine compound having at least two primary amino groups in one molecule include p-phenylenediamine, m-phenylenediamine, o-phenylenediamine, 3-methyl-1,4-diaminobenzene, 5-dimethyl-1,4-diaminobenzene, 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyl-diphenylmethane, 4,4'-diamino-3,3'-diethyl-diphenylmethane 4,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl sulfone, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl ketone, benzidine, 3,3'-dimethyl-4,4'- Diaminobiphenyl, 2,2'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dihydroxybenzidine, , 2-bis (3-amino-4-hydroxyphenyl) propane, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanediamine, 2,2-bis (4-aminophenyl) propane, 2, 2-bis (4- (4-aminophenoxy) phenyl) propane, trimethylene bis (4-aminobenzoate), 1,3-bis (3-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) ) Benzene, 1,4-bis (4-aminophenoxy) benzene, 4,4′-bis (4-aminophenoxy) biphenyl, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (3 And -aminophenoxy) phenyl) sulfone, 9,9-bis (4-aminophenyl) fluorene and the like. You may use these individually or in mixture of 2 or more types.

  Among these, for example, 4,4′-diaminodiphenylmethane, 3,3′-dimethyl-4,4′-diaminobiphenyl, 4,4 ′ from the viewpoint of high reactivity during reaction and higher heat resistance. -Diamino-3,3'-dimethyl-diphenylmethane, 4,4'-diamino-3,3'-diethyl-diphenylmethane, 4,4'-bis (4-aminophenoxy) biphenyl, 2,2-bis (4-) (4-Aminophenoxy) phenyl) propane and trimethylene bis (4-aminobenzoate) are preferable. Furthermore, from the viewpoint of low cost and solubility in solvents, 4,4'-diaminodiphenylmethane, 3,3'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-3,3 ' -Diethyl-diphenylmethane, 2,2-bis (4- (4-aminophenoxy) phenyl) propane and trimethylene bis (4-aminobenzoate) are more preferable. Furthermore, from the viewpoint of low thermal expansion and dielectric properties, 4,4'-diamino-3,3'-diethyl-diphenylmethane, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, trimethylene bis ( Particularly preferred is 4-aminobenzoate). Further, p-phenylenediamine, m-phenylenediamine, 3-methyl-1,4-diaminobenzene, and 2,5-dimethyl-1,4-diaminobenzene which can be made to have a high elastic modulus are also preferably used.

  The content of the amine-based curing agent of component (B) is preferably 10 to 30 parts by mass, more preferably 12 to 28 parts by mass, still more preferably 100 parts by mass of the thermosetting resin of component (A). It is 15-25 mass parts.

[(C) Phenoxy resin having a weight average molecular weight of 30,000 to 150,000]
The phenoxy resin of component (C) is a polyhydroxy polyether synthesized from bisphenols and epichlorohydrin. As the phenoxy resin of the component (C), bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenol acetophenone skeleton, novolac skeleton, biphenyl skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane What has one or more types of frame | skeleton selected from frame | skeleton, terpene frame | skeleton, and trimethyl cyclohexane frame | skeleton is mentioned. These phenoxy resins may be used alone or in combination of two or more. The terminal of the phenoxy resin may be any functional group such as phenolic hydroxyl group and epoxy group.

  The weight average molecular weight of the phenoxy resin of component (C) is in the range of 30,000 to 150,000, preferably in the range of 30,000 to 100,000, more preferably in the range of 30,000 to 50,000. . If the weight average molecular weight is less than 30,000, the film formability is significantly reduced. If the weight average molecular weight is more than 150,000, the viscosity of the material is too high to affect the coatability.

  As a commercial item of the phenoxy resin of a component (C), Mitsubishi Chemical Co., Ltd. product 1256, 4250 (bisphenol A frame | skeleton containing phenoxy resin), Mitsubishi Chemical Co., Ltd. YX 8100 BH30 (bisphenol S frame | skeleton containing phenoxy resin), Mitsubishi YX6954BH30 (a bisphenol acetophenone skeleton-containing phenoxy resin) manufactured by Chemical Co., Ltd., FX280 and FX293 manufactured by Tohto Kasei Co., Ltd., and YL7553 and YL6794 and YL7213, YL7290 and YL7482 manufactured by Mitsubishi Chemical Corporation.

  The content of the phenoxy resin of the component (C) is 50 to 200 parts by mass, preferably 60 to 160 parts by mass, more preferably 70 to 120 parts by mass with respect to 100 parts by mass of the thermosetting resin of the component (A). It is a department. When the amount is less than 50 parts by mass, the coating property is reduced, and when the amount is more than 200 parts by mass, the heat resistance is reduced.

[(D) Inorganic filler]
The inorganic filler of the component (D) is not particularly limited as long as the effects of the present invention can be obtained, but for example, silica, alumina, hydrotalcite, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide , Calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum borate, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, etc. Be Among these, single use of silica such as amorphous silica, fused silica, crystalline silica, synthetic silica and the like and combination use of silica and hydrotalcite are preferable, and combination use of silica and hydrotalcite is more preferable. In addition, as a silica, a spherical thing is preferable.
The inorganic filler may be used alone or in combination of two or more.

1 micrometer or less is preferable, as for the average particle diameter of the inorganic filler of component (D), 0.8 micrometer or less is more preferable, and 0.7 micrometer or less is still more preferable. If the average particle size is 1 μm or less, it is possible to suppress the decrease in peel strength of the conductor layer formed by plating. When the average particle diameter of the inorganic filler is too small, when the resin composition is made into a resin varnish, the viscosity of the varnish tends to increase and the handleability tends to decrease, so the average particle diameter is 0.05 μm. It is preferable that it is more than.
The average particle size of the inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be prepared on a volume basis by a laser diffraction type particle size distribution measuring apparatus, and the median diameter can be measured as an average particle size. As a measurement sample, one in which an inorganic filler is dispersed in water by ultrasonic waves can be preferably used. As a laser diffraction type particle size distribution measuring apparatus, LA-500 etc. by Horiba, Ltd. can be used, for example.

  The inorganic filler of component (D) is an epoxysilane type coupling agent such as aminopropyl methoxysilane or aminopropyltriethoxysilane to improve moisture resistance, dispersibility, etc., mercatopropyltrimethoxysilane, mercatopropyl Mercaptosilane-based coupling agents such as triethoxysilane, organosilazane compounds such as methyltrimethoxysilane and octadecyltrimethoxysilane, butyl titanates dimers, titanates such as titanium octylene glycolate, and diisopropoxy titanium bis (triethanol aminate) It may be treated with one or more surface treatment agents such as a system coupling agent.

  The content of the inorganic filler of the component (D) is 200 to 1000 parts by mass, preferably 250 to 700 parts by mass, more preferably 300 to 500 with respect to 100 parts by mass of the thermosetting resin of the component (A). It is a mass part. If the amount is less than 200 parts by mass, the coefficient of thermal expansion tends to increase, and if the amount is more than 1000 parts by mass, the flexibility of the metal foil-attached adhesive sheet tends to decrease.

  Further, the content of the inorganic filler of the component (D) is preferably 40 to 100% by mass, more preferably 50 to 80% by mass, still more preferably 55 to 50% by mass with respect to 100% by mass of nonvolatile components in the resin composition. It is 70% by mass. If the content of the inorganic filler is too low, the coefficient of thermal expansion tends to increase, and if the content is too high, the flexibility of the metal foil-attached adhesive sheet tends to decrease.

[Other ingredients]
The resin composition may optionally contain various resin additives other than the components described above, as long as the effects of the present invention are exhibited. Examples of resin additives include organic fillers such as silicon powder, nylon powder and fluorine powder; thickeners such as orben and benton; silicone based, fluorine based, polymeric based antifoaming agent or leveling agent; silane cup Ring agents; adhesion-imparting agents such as triazole compounds, thiazole compounds, triazine compounds, and porphyrin compounds; and phthalocyanine pigments such as phthalocyanine blue, phthalocyanine green, iodine green, disazo yellow, carbon black and the like. Also, imidazole compounds such as CuaZole 2MZ, 2E4MZ, C11Z, C11Z-CN, C11Z-CNS, C11Z-A, 2MZ-OK, 2MA-OK, 2PHZ (trade names of Shikoku Kasei Kogyo Co., Ltd.) and the like; Amine adduct compounds such as Fujicure (trade name), Fujicure (trade name, manufactured by T & K TOKA); 1, 8-Diazabicyclo (5, 4, 0) undecene-7 (hereinafter abbreviated as DBU) And tertiary amine compounds such as tetraphenyl borate salts; and amine-based curing accelerators such as, for example.

  The method for preparing the resin composition is not particularly limited, and examples thereof include a method in which a solvent and the like are added to the compounding components as necessary, and mixing is performed using a rotary mixer and the like.

  The adhesive sheet with metal foil of the present invention is prepared by a method known to those skilled in the art, for example, preparing a resin varnish in which a resin composition is dissolved in an organic solvent, applying the resin varnish on metal foil, and heating or The organic solvent can be dried by hot air blowing or the like to form an adhesive layer.

  Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone; ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate, acetates such as carbitol acetate; carbitol such as cellosolve and butyl carbitol And aromatic hydrocarbons such as toluene and xylene; and amide solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone. The organic solvent may be used alone or in combination of two or more.

  The drying conditions are not particularly limited, but the content of the organic solvent in the adhesive layer is preferably 10% by mass or less, more preferably 5% by mass or less. As drying conditions, suitable drying conditions can be appropriately set by simple experiments. Depending on the amount of organic solvent in the resin varnish, for example, a resin varnish containing 30 to 60% by mass of the organic solvent can be dried at 50 to 150 ° C. for about 3 to 10 minutes.

The thickness of the adhesive layer formed in the adhesive sheet with metal foil is preferably equal to or greater than the thickness of the conductor layer of the circuit board. Since the thickness of the conductor layer is usually in the range of 5 to 70 μm, the thickness of the adhesive layer is preferably in the range of 10 to 100 μm.
Also, the adhesive layer may be protected by a protective film described later. By protecting with a protective film, it is possible to prevent adhesion of dust and the like to the surface of the adhesive layer and scratches.

(Metal foil)
As a metal foil in this invention, copper foil, an aluminum foil, etc. are mentioned.
Although the thickness in particular of metal foil is not restrict | limited, The range of 1-40 micrometers is preferable, and the range of 10-30 micrometers is more preferable.

The adhesive sheet with metal foil of the present invention may have a support on the metal foil. The support is peeled after laminating an adhesive sheet with a metal foil on an inner layer circuit board or the like, or after forming an insulating layer by heat curing. If the support is peeled after the metal foil-attached adhesive sheet is heated and cured, adhesion of dust and the like in the curing step can be prevented, and the surface smoothness of the insulating layer after curing can be improved. In the case of peeling after curing, the support is preferably subjected to release treatment in advance.
Moreover, the adhesive sheet with metal foil may be equipped with a protective film on an adhesive layer. The adhesive layer formed on the protective film is preferably formed so that the area of the layer is smaller than the area of the protective film.
The metal foil-adhered adhesive sheet can be wound into a roll and stored and stored.

  In the adhesive sheet with metal foil of the present invention, an insulating layer mainly composed of silica powder may be interposed between the metal foil and the adhesive layer, and a primer layer is interposed between the metal foil and the insulating layer. It may be At this time, the total thickness of the primer layer, the insulating layer, and the adhesive layer on the metal foil is not particularly limited, but is preferably 15 μm or less.

  The amount of silica in the insulating layer containing silica powder as the main component is preferably in the range of 60 to 90% by mass, and preferably in the range of 70 to 90% by mass, with respect to 100% by mass of nonvolatile components in the material composition. Is more preferable. When the content of the silica powder is 60% by mass or more, the thermal expansion does not become too large, and when it is formed into a substrate, warpage can be suppressed, and when it is 90% by mass or less, dropping of the silica powder is suppressed It is possible to suppress the decrease in film formability.

  The insulating layer is preferably made of amorphous (non-crystalline) silica powder. When the silica powder is in an amorphous state, the anisotropy of the thermal expansion coefficient due to the crystal structure can be reduced. Therefore, when the adhesive sheet with metal foil of the present invention is used for a wiring substrate, when the wiring substrate is heated, the shrinkage of the insulating layer can be made more uniform in each direction when cooling after heating. It is possible to reduce the occurrence of cracks in the insulating layer.

  A primer layer is a layer which consists of a hardened | cured material of a resin composition, and is provided in order to improve the adhesiveness of metal foil and an insulating layer. The resin composition for forming the primer layer is not particularly limited. For example, a resin composition containing a solid epoxy resin having a naphthalene skeleton and a liquid epoxy resin having a naphthalene skeleton is preferable, and from the viewpoint of insulation and reliability, The resin composition which forms the adhesive bond layer of is more preferable.

  The adhesive sheet with metal foil of the present invention has a low coefficient of thermal expansion and is excellent in coating property, adhesion, insulation and heat resistance, and hence a printed wiring board excellent in insulation reliability and a semiconductor in which warpage is suppressed. Package can be provided. Further, the adhesive sheet with metal foil is suitably used for electronic devices such as various audio visual devices, home appliances, communication devices, computer devices and their peripheral devices.

[Manufacturing method of multilayer printed wiring board etc. using adhesive sheet with metal foil]
Next, a method for producing a circuit board such as a multilayer printed wiring board of the present invention using the adhesive sheet with metal foil of the present invention will be described.
When the adhesive layer is protected by a protective film, these are peeled off, and then the adhesive layer is laminated on one side or both sides of the inner layer circuit board so as to be in direct contact with the inner layer circuit board. In the adhesive sheet with metal foil of the present invention, a method of laminating on the inner layer circuit board under reduced pressure by vacuum lamination is suitably used. The method of lamination may be batchwise or continuous in rolls. In addition, the adhesive sheet with metal foil and the inner layer circuit board may be heated (preheated) as necessary before laminating.

  The inner layer circuit board in the present invention mainly refers to a conductor layer (circuit) patterned on one side or both sides of a substrate such as glass epoxy, metal substrate, polyester substrate, polyimide substrate, BT resin substrate, thermosetting type polyphenylene ether substrate, etc. Say what was formed. In addition, when manufacturing a multilayer printed wiring board in which a conductor layer and an insulating layer are alternately formed to form a conductor layer (circuit) patterned on one side or both sides, an insulating layer and a conductor layer are further formed. Intermediate products to be produced are also included in the inner layer circuit board in the present invention. In the inner layer circuit board, it is preferable from the viewpoint of adhesion of the insulating layer to the inner layer circuit board that the surface of the conductor circuit layer is roughened in advance by blackening treatment or the like.

Moreover, it is also possible to perform the lamination | stacking process of heating and pressurizing under pressure reduction using a general vacuum hot press. For example, it can be carried out by pressing a heated metal plate such as a SUS plate from the support layer side.
As pressing conditions, the pressure reduction degree is preferably 1 × 10 ⁻² MPa or less, and more preferably 1 × 10 ⁻³ MPa or less. Although heating and pressurization can be performed in one step, it is preferable to divide the conditions into two or more steps in order to control the bleeding of the resin. For example, the first stage of the press, the temperature is 70 to 150 ° C., the range of pressure 1~15kgf / cm ^2, the second stage of the press, the temperature is 150 to 200 ° C., a pressure of 1~40kgf / cm ² It is preferable to carry out in the range. The time of each step is preferably 30 to 120 minutes. As a vacuum hot press marketed commercially, MNPC-V-750-5-200 (made by Meiki Seisakusho KK), VH1-1603 (made by Kitagawa Seiki Co., Ltd.) etc. are mentioned, for example.

  After laminating the adhesive sheet with metal foil on the inner layer circuit board as described above, the insulating layer can be formed on the inner layer circuit board by peeling off the support when peeling off the support and thermally curing the resin composition. The conditions for heat curing are selected in the range of 20 minutes to 180 minutes at 150 ° C. to 220 ° C., and more preferably 30 minutes to 120 minutes at 160 ° C. to 200 ° C. After forming the insulating layer, if the support is not peeled off before curing, it is peeled off here. Next, holes are formed in the insulating layer formed on the inner layer circuit board to form via holes and through holes. For example, drilling can be performed by a known method such as a drill, laser, plasma or the like and, if necessary, a combination of these methods, but laser drilling such as a carbon dioxide gas laser or a YAG laser is the most common. Method.

  Next, the surface of the insulating layer is roughened. The roughening treatment in the present invention is preferably performed by a wet roughening method using an oxidizing agent. Examples of the oxidizing agent include permanganate (potassium permanganate, sodium permanganate etc.), dichromate, ozone, hydrogen peroxide / sulfuric acid, nitric acid and the like. An alkaline permanganic acid solution (eg, potassium permanganate, sodium hydroxide aqueous solution of sodium permanganate), which is an oxidizing agent generally used for roughening an insulating layer in the manufacture of a multilayer printed wiring board preferably by a build-up method Preferably, the roughening is carried out using

  The roughness of the roughened surface obtained by roughening the surface of the insulating layer is preferably 0.05 to 0.5 μm in terms of an Ra value to form a fine wiring. The Ra value is a kind of numerical value representing surface roughness, and is called arithmetic average roughness, and specifically, from the surface which is an average line, the absolute value of the height changing in the measurement area Measured and arithmetically averaged. For example, using WYKO NT3300 manufactured by Becoin Instruments, it can be determined by a numerical value obtained with a measurement range of 121 μm × 92 μm with a VSI contact mode, 50 × lens.

Next, a conductor layer is formed on the surface of the resin composition layer on which the concavo-convex anchors are formed by the roughening treatment, by a method combining electroless plating and electrolytic plating. Alternatively, a plating resist having a pattern reverse to that of the conductor layer may be formed, and the conductor layer may be formed only by electroless plating. The peel strength of the conductor layer can be further improved and stabilized by performing annealing treatment at 150 to 200 ° C. for 20 to 90 minutes after forming the conductor layer. The peel strength of the conductor layer is preferably 6 kgf / cm or more.
Further, as a method for patterning the conductor layer and forming a circuit, for example, a subtractive method, a semi-additive method or the like known to those skilled in the art can be used.

  EXAMPLES The present invention will next be described in detail by way of examples, which should not be construed as limiting the invention thereto. The materials used in the following examples and comparative examples are as shown in Table 1. Also, "parts" means "parts by mass" unless otherwise specified.

(Examples 1 to 7 and Comparative Examples 1 to 5)
(1) Preparation of resin varnish Each component of the kind and compounding quantity of Table 1 was mixed using the rotation mixer, and the resin varnish was prepared.

(2) Preparation of adhesive sheet with metal foil A coater is placed on one side of an electrolytic copper foil (JDLC, thickness 18 μm, manufactured by JX Metal Corp.) as a metal foil from the resin varnish obtained in the above (1) It applied so that thickness after drying (after semi-hardening) might be set to 15 micrometers. This was dried for 3 minutes in a drying apparatus at 120 ° C. to obtain an adhesive layer. Thus, a metal foil-attached adhesive sheet was produced.

(3) Preparation of two-layer adhesive sheet with metal foil After forming an insulating layer containing silica as a main component on one side of an electrolytic copper foil (JDLC, thickness 18 μm, manufactured by JX Metals Co., Ltd.) as metal foil, The resin varnish was applied using a coater so that the thickness after drying (after semi-curing) was 15 μm. This was dried for 3 minutes in a drying apparatus at 120 ° C. to obtain an adhesive layer. Thus, a two-layer adhesive sheet with metal foil (metal foil / insulating layer / adhesive layer) was produced.

(4) Preparation of 3-layer adhesive sheet with metal foil After drying the resin varnish on one side of an electrolytic copper foil (JDLC, thickness 18 μm, manufactured by JX Metals Co., Ltd.) as metal foil using a coater (after semi-curing) ) To a thickness of 1.5 μm to form a primer layer. Subsequently, the insulating layer which has a silica as a main component was formed on this primer layer, and the resin varnish used at the time of primer layer formation was coated on this insulating layer so that total thickness might be 15 micrometers. This was dried for 3 minutes in a drying apparatus at 120 ° C. to obtain an adhesive layer. Thus, a three-layer adhesive sheet with metal foil (metal foil / primer layer / insulating layer / adhesive layer) was produced.

(5) Production of single-sided copper-clad laminate Place the adhesive layer side of the adhesive sheet with metal foil obtained in (2) above on one side of the FR-4 substrate, and further attach the metal foil. The adhesive layer side of the adhesive sheet with metal foil obtained in the above (2) is disposed on the metal foil of the adhesive sheet, and the adhesive sheet 2 with metal foil is disposed on one side of the FR-4 substrate. The sheets were laminated, and heated and pressed for 1 hour under a pressing condition of 200 ° C. and 30 kgf / mm ² using a hot press to be cured. Thus, a single-sided copper-clad laminate was produced.

(6) Manufacture of double-sided copper-clad laminate
The adhesive layers of the two metal foil-attached adhesive sheets obtained in the above (2) are made to face each other and stacked, and heated at a temperature of 200 ° C. and 30 kgf / mm ² for 1 hour using a hot press. Press and cure. Thus, a double-sided copper-clad laminate in which the metal foil-attached adhesive sheets were bonded to each other was produced.

(7) Preparation of Printed Wiring Board The adhesive sheet of each layer thickness with metal foil obtained in the above (3) and (4) is laminated on both sides of the core substrate, and pressing conditions of 30 ° C. and 30 kgf / mm ² using a hot press. The mixture was heated and pressed for 1 hour to cure. Thereafter, the copper foil was etched away to expose the insulating layer. Next, through holes (through holes) were formed by a carbonic acid laser. Next, the through hole and the surface of the insulating layer were immersed in a swelling solution at 80 ° C. for 10 minutes, and further immersed in an aqueous solution of potassium permanganate at 80 ° C. for 5 minutes, and then neutralized and roughened. After degreasing, catalyzing and activating processes, the electroless copper plating film is formed to about 1 μm, plating resist is formed, and the electroless copper plating film is formed as a feeding layer to form pattern electroplating copper 12 μm, L / S = A microcircuit processing of 12/12 μm was performed. Next, after annealing treatment was performed at 200 ° C. for 60 minutes in a hot air drying apparatus, the feed layer was removed by flash etching.
Next, a solder resist was printed, exposed with a predetermined mask so that the semiconductor element mounting pad and the like were exposed, developed and cured, and the solder resist layer on the circuit was formed to have a thickness of 12 μm. .
Finally, on the circuit layer exposed from the solder resist layer, a plating layer consisting of 3 μm of electroless nickel plating layer and 0.1 μm of electroless gold plating layer was formed to obtain a printed wiring board.

In addition, in said (1), the detail of each component of Table 1 used for preparation of the resin varnish is as follows.
<Thermosetting resin>
[(A) component]
· HP 6000: Naphthalene-type multifunctional solid epoxy resin, manufactured by DIC Corporation, trade name · HP 4700: Naphthalene-type 4-functional solid epoxy resin, manufactured by DIC Corporation, trade name · HP4032D: Naphthalene-type bifunctional liquid epoxy resin, DIC Co., Ltd. product name [epoxy resin other than component (A)]
・ EPICLON 830S: Bisphenol F type epoxy resin, manufactured by DIC Corporation, trade name

<Amine curing agent>
[(B) component]
-CUA-4: trimethylene bis (4-aminobenzoate), manufactured by Kumiai Chemical Industry Co., Ltd., trade name-DICY 7: dicyandiamide, manufactured by Mitsubishi Chemical Co., Ltd., trade name [B) curing agent other than component]
SN-475: Naphthol type curing agent, manufactured by Nippon Steel Chemical Co., Ltd., trade name

<Phenoxy resin having a weight average molecular weight of 30,000 to 150,000>
[(C) component]
-YX 6954 BH 30: weight average molecular weight 40, 000, manufactured by Mitsubishi Chemical Corporation, trade name-YX 8100 BH 30: weight average molecular weight 35,000, manufactured by Mitsubishi Chemical Corp., trade name [phenoxy resin other than component (C)]
· YL7734: weight average molecular weight 20,000, manufactured by Mitsubishi Chemical Corporation, trade name

<Inorganic filler>
[(D) component]
· SC2500 SPJ: spherical silica, manufactured by Admatex Co., Ltd., trade name, average particle diameter 0.5 μm
・ DHT-4C: Hydrotalcite, manufactured by Kyowa Chemical Industry Co., Ltd., trade name, average particle size 0.4 μm

<Other ingredients>
Hardening accelerator: 2E4MZ (2-ethyl-4-methylimidazole), manufactured by Shikoku Kasei Kogyo Co., Ltd., trade name, solvent: cyclohexanone

<Evaluation item>
(8) Coating film property The film thickness of the adhesive sheet with metal foil obtained in the above (2) was measured with a microphone meter. Five in-plane points were arbitrarily measured, and it was evaluated whether the average value was 15 μm ± 1.5 μm.

(9) Melt Viscosity The adhesive sheet with a metal foil obtained in the above (2) was scraped out of the resin material only, and the melt viscosity of a powdery state was measured. The measurement conditions were a temperature rise of 5 ° C. from room temperature (25 ° C.) to 200 ° C., and it was evaluated whether the minimum melt viscosity as measured was 1000 ± 500 mPa · s.

(10) Adhesiveness 30 μm of electroplated copper was formed on the copper foil side of the single-sided copper clad laminate obtained in the above (5), and annealing treatment was performed at 200 ° C. for 60 minutes with a hot air dryer. The test piece of 100 mm x 20 mm was produced based on JIS-C-6481, and the adhesiveness in 23 degreeC was measured. In addition, a measured value made 0.6 kN / m or more a pass.

(11) Insulating Property With respect to the single-sided copper-clad laminate obtained in the above (5), the insulation resistance during continuous wetting was evaluated under the conditions of a temperature of 130 ° C., a humidity of 85%, and an applied voltage of 15V. The resistance value of less than 1.0 × 8 EΩ was regarded as failure.

(12) Thermal Expansion Coefficient The metal foil of the double-sided copper-clad laminate obtained in (6) above was removed by etching to prepare a 4 mm × 20 mm test piece from the adhesive sheet layer. The thermal expansion of this test piece in the planar direction at 30 to 150 ° C. in the second cycle under the conditions of a temperature range of 30 to 300 ° C., 10 ° C./min, and a load of 5 g using a TMA apparatus (manufactured by TA Instruments) The coefficients were measured. The thermal expansion coefficient up to 100 ° C. was 25 ppm / ° C. or less.

(13) Heat Resistance The metal foil of the double-sided copper-clad laminate obtained in (6) above was removed by etching to prepare a 6 mm × 25 mm test piece from the gold adhesive sheet layer. The temperature of the test piece was raised at 5 ° C./minute (frequency: 1 Hz) using a DMA apparatus (manufactured by TA Instruments), and the peak position of tan δ was taken as the heat resistant temperature. The temperature passed at 170 ° C. or higher.

(14) Reliability
Using a test sample of the printed wiring board obtained in the above (7), after performing moisture absorption treatment under conditions of temperature 85 ° C., humidity 85%, 24 hours, reliability is evaluated with a solder tester at 300 ° C. did. Five samples were placed on a solder tester for 1 minute to count samples that did not swell.

  The above results are shown in Table 1. The metal foil and adhesive sheet of Examples 1 to 7 retained good properties. Moreover, the thing using those printed wiring boards was excellent in reliability. On the other hand, the printed wiring boards of Comparative Examples 1 to 5 obtained with the adhesive sheet with a metal foil containing no change of the epoxy material or the curing agent or the phenoxy resin were not reliable.

10, 20, 30. Adhesive sheet with metal foil 1, 11, 21. Metal foil 2, 12, 22. Adhesive layer 13, 23. Insulating layer 24. Primer layer

Claims (6)

With metal foil,
And an adhesive layer provided on the metal foil,
The adhesive layer comprises (A) a thermosetting resin comprising a solid epoxy resin having a naphthalene skeleton and a liquid epoxy resin having a naphthalene skeleton, (B) an amine curing agent, and (C) a weight average molecular weight of 30,000 to It consists of a resin composition containing 150,000 phenoxy resin and (D) inorganic filler, and 50 to 200 parts by mass of (C) phenoxy resin with respect to 100 parts by mass of the (A) thermosetting resin, (D 2.) An adhesive sheet with metal foil comprising 200 to 1000 parts by mass of an inorganic filler.   The metal foil-attached adhesive sheet according to claim 1, wherein the (D) inorganic filler contains silica and hydrotalcite.   The metal foil and adhesive sheet according to claim 1 or 2, wherein an insulating layer mainly composed of silica powder is interposed between the metal foil and the adhesive layer.   The metal according to claim 3, wherein a primer layer is further interposed between the metal foil and the insulating layer, and the total thickness of the adhesive layer, the insulating layer, and the primer layer is 15 μm or less. Adhesive sheet with foil.   The said insulating layer consists of said silica powder of an amorphous state, The adhesive sheet with metal foil of Claim 3 or 4 characterized by the above-mentioned.   The wiring board using the adhesive sheet with a metal foil in any one of Claims 1-5.