CN114501803A

CN114501803A - Method for manufacturing printed wiring board

Info

Publication number: CN114501803A
Application number: CN202111256944.1A
Authority: CN
Inventors: 渡边真俊; 鹤井一彦
Original assignee: Ajinomoto Co Inc
Current assignee: Ajinomoto Co Inc
Priority date: 2020-10-28
Filing date: 2021-10-27
Publication date: 2022-05-13
Also published as: KR20220056810A; TW202231467A; JP2022071490A; JP7371606B2

Abstract

The invention provides a method for manufacturing a printed wiring board, which can form a small-diameter through hole, has excellent stain removability and can restrain the occurrence of halo phenomenon. The solution of the present invention is a method for manufacturing a printed wiring board, which sequentially comprises: (A) a step of forming an opening in an insulating layer containing a cured product of a resin composition by laser, and (B) a step of forming a through hole by blasting the opening with abrasive grains.

Description

Method for manufacturing printed wiring board

Technical Field

The present invention relates to a method for manufacturing a printed wiring board.

Background

In recent years, multilayer stacked (build-up) layers have been used in printed wiring boards, and miniaturization and high-density wiring have been demanded. The stacked layer is formed by a stacking (build-up) method in which insulating layers and conductor layers are alternately stacked, and in a manufacturing method using the stacking method, the insulating layers are generally formed by thermally curing a resin composition.

A large number of resin compositions suitable for forming an insulating layer of an inner circuit board have been proposed, including, for example, the resin composition described in patent document 1.

Documents of the prior art

Patent document

Patent document 1: japanese patent laid-open publication No. 2017-59779.

Disclosure of Invention

Problems to be solved by the invention

In addition, in the production of a printed wiring board, a through hole may be formed in an insulating layer. "vias" generally refer to holes through an insulating layer. As a method of forming the through hole, a method using a laser is considered.

When the through-hole is formed by laser, a resin residue called smear (smear) may be formed in the through-hole. In order to remove the contamination, after the via hole is formed with the laser, a desmearing treatment for removing the contamination using a chemical solution is generally performed. The present inventors found that heat is generated upon irradiation with laser light, and the heat is transferred to the insulating layer and the base metal of the inner layer circuit substrate to generate a halo (halo) phenomenon. The halo phenomenon is the occurrence of peeling between the insulating layer around the through hole and the inner layer circuit substrate. Such a halo phenomenon is generally caused by deterioration of the resin around the through hole by heat, and erosion of the deteriorated portion by a chemical solution such as a roughening solution. The deteriorated portion is usually observed as a discolored portion.

Further, although a method of suppressing the halo phenomenon by using a sand blast (sandblast) treatment is considered, it is difficult to form a through hole with a small diameter by the sand blast treatment, and the processing speed of the through hole may be slow.

The present invention has been made in view of the above circumstances, and provides a method for manufacturing a printed wiring board, which can form a small-diameter through hole, has excellent stain removability, and suppresses the occurrence of halo phenomenon.

Means for solving the problems

The present inventors have conducted extensive studies to solve the above problems, and as a result, have found that a through hole is formed by sandblasting after an opening portion is formed by laser, whereby stain removability is excellent and a halo phenomenon can be suppressed, thereby completing the present invention.

That is, the present invention includes the following;

[1] a method of manufacturing a printed wiring board, comprising in order: (A) a step (B) of forming an opening in an insulating layer containing a cured product of a resin composition by laser, and a step (B) of forming a through hole by blasting the opening with abrasive grains;

[2] the method for manufacturing a printed wiring board according to [1], wherein the abrasive grains have an average particle diameter of 10 μm or less;

[3] the method for manufacturing a printed wiring board according to item [1] or [2], wherein a depth of the opening is 50% or more and 95% or less of a thickness of the insulating layer;

[4] the method of manufacturing a printed wiring board according to any one of [1] to [3], wherein the step (B) is a step of forming a through hole by causing abrasive grains to collide with a bottom surface of the opening portion through a mask,

the ratio of the sum of the thickness of the mask and the depth of the opening to the opening diameter of the through hole (sum/opening diameter) is 3 or less;

[5] the method for manufacturing a printed wiring board according to any one of [1] to [4], wherein the insulating layer has an elastic modulus of 0.1GPa or more at 23 ℃;

[6] the method for manufacturing a printed wiring board according to any one of [1] to [5], wherein the resin composition contains an inorganic filler;

[7] the method for producing a printed wiring board according to item [6], wherein the content of the inorganic filler is 20% by mass or more, assuming that 100% by mass of nonvolatile components in the resin composition are present;

[8] the method for manufacturing a printed wiring board according to any one of [1] to [7], wherein the resin composition contains a curable resin;

[9] the method for producing a printed wiring board according to item [8], wherein the curable resin is contained in an amount of 10% by mass or more, assuming that 100% by mass of nonvolatile components in the resin composition are present;

[10] the method for manufacturing a printed wiring board according to [8] or [9], wherein the curable resin comprises an epoxy resin and a curing agent;

[11] the method for manufacturing a printed wiring board according to item [10], wherein the curing agent is at least one selected from a phenol-type resin, an active ester-based resin, and a cyanate ester-based resin;

[12]according to [1]]～[11]The method for manufacturing a printed wiring board, wherein the laser is CO₂Laser or UV-YAG laser.

Effects of the invention

According to the present invention, there can be provided: a method for manufacturing a printed wiring board, which can form a small-diameter through hole, has excellent stain removability, and suppresses the occurrence of a halo phenomenon.

Drawings

FIG. 1: FIG. 1 is a schematic cross-sectional view showing an example of a pattern in which an insulating layer and a support are formed on a main surface of an inner layer circuit board;

FIG. 2: FIG. 2 is a schematic cross-sectional view showing an example of a pattern after the step (A) is performed;

FIG. 3: FIG. 3 is a schematic cross-sectional view showing an example of a pattern after the step (B) is performed;

FIG. 4: fig. 4 is a plan view schematically showing an insulating layer of a conventional printed wiring board in which a via hole is formed by laser processing immediately before a conductor layer is formed;

FIG. 5: fig. 5 is a sectional view schematically showing an insulating layer of a conventional printed wiring board in which a via hole is formed by laser processing immediately before a conductor layer is formed;

FIG. 6: FIG. 6 is a schematic cross-sectional view showing an example of a pattern in which an insulating layer and a metal foil are formed on a main surface of an inner layer circuit board;

FIG. 7: FIG. 7 is a schematic cross-sectional view showing an example of a pattern obtained by subjecting a metal foil to a pattern etching process;

FIG. 8: FIG. 8 is a schematic cross-sectional view showing an example of a pattern after the step (A) is performed;

FIG. 9: FIG. 9 is a schematic sectional view showing an example of a pattern after the step (B) is performed;

FIG. 10: fig. 10 is a schematic cross-sectional view showing an example of a pattern after forming a filled via (FilledVia);

FIG. 11: fig. 11 is a schematic cross-sectional view showing an example of a pattern in which an insulating layer, a metal foil, and a dry film are formed on a main surface of an inner layer circuit substrate;

FIG. 12: FIG. 12 is a schematic cross-sectional view showing an example of a pattern after exposure and development;

FIG. 13: FIG. 13 is a schematic sectional view showing an example of a pattern after the step (A) is performed;

FIG. 14 is a schematic view of: FIG. 14 is a schematic sectional view showing an example of a pattern after the step (B) is performed;

FIG. 15: FIG. 15 is a schematic cross-sectional view showing an example of a pattern after filling a via hole;

FIG. 16: FIG. 16 is a schematic sectional view showing an example of a pattern from which a dry film is removed;

FIG. 17: fig. 17 is a schematic cross-sectional view showing an example of a pattern in which an insulating layer and a dry film are formed on a main surface of an inner layer circuit board;

FIG. 18: FIG. 18 is a schematic sectional view showing an example of a pattern after exposure and development;

FIG. 19: FIG. 19 is a schematic sectional view showing an example of a pattern after the step (A) is performed;

FIG. 20: FIG. 20 is a schematic sectional view showing an example of a pattern after the step (B) is performed;

FIG. 21: fig. 21 is a schematic cross-sectional view showing an example of a pattern after filling a through-hole.

Detailed Description

The present invention will be described in detail below with reference to embodiments and examples. The present invention is not limited to the embodiments and examples described below, and may be optionally modified and practiced within the scope not departing from the claims and their equivalents.

Before describing the method for producing a printed wiring board of the present invention in detail, a description will be given of a "resin composition" and a "resin sheet with a support" used in the method for producing a printed wiring board of the present invention.

[ resin composition ]

The resin composition used for forming the cured product may be a resin composition having sufficient hardness and insulation properties for an insulating layer as a cured product thereof. In one embodiment, the resin composition comprises (a) an inorganic filler. The resin composition may further contain (b) a curable resin, (c) a curing accelerator, (d) a thermoplastic resin, (e) an elastomer, and (f) other additives, as required. Hereinafter, each component contained in the resin composition will be described in detail.

(a) an inorganic filler

The resin composition contains (a) an inorganic filler. As a material of the inorganic filler, an inorganic compound is used. Examples of the material of the inorganic filler include: silica, alumina, aluminum silicate, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate, calcium zirconate, zirconium phosphate, zirconium tungstate phosphate, and the like. Among them, calcium carbonate and silica are preferable, and silica is particularly preferable. Examples of the silica include amorphous silica, fused silica, crystalline silica, synthetic silica, hollow silica and the like. Further, the silica is preferably spherical silica. (a) The inorganic filler may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

Commercially available products of component (a) include, for example, "UFP-30" and "ASFP-20" manufactured by Denka corporation; "SP 60-05", "SP 507-05", "SPH 516-05" manufactured by Nippon iron chemical materials, Inc.; "YC 100C", "YA 050C", "YA 050C-MJE", "YA 010C" manufactured by yadu ma (Admatechs) corporation; "Silfil NSS-3N", "Silfil NSS-4N", "Silfil NSS-5N" manufactured by Tokuyama corporation; "SC 2500 SQ", "SO-C4", "SO-C2", "SO-C1" manufactured by Yatoma corporation; and the like.

The specific surface area of the component (a) is preferably 1m²A ratio of 2m or more, more preferably 2m²A specific ratio of 3m or more in terms of/g²More than g. The upper limit is not particularly limited, but is preferably 60m²Less than 50 m/g²Less than or equal to 40 m/g²The ratio of the carbon atoms to the carbon atoms is less than g. The specific surface area can be obtained by adsorbing nitrogen gas onto the surface of a sample according to the BET method using a specific surface area measuring apparatus (Macsorb HM-1210, manufactured by Mountech corporation) and calculating the specific surface area by the BET multipoint method.

The average particle diameter of the component (a) is preferably 0.01 μm or more, more preferably 0.05 μm or more, further preferably 0.1 μm or more, preferably 5 μm or less, more preferably 2 μm or less, further preferably 1 μm or less, from the viewpoint of remarkably obtaining the desired effect of the present invention.

(a) The average particle diameter of the component 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 measured by preparing the particle size distribution of the inorganic filler on a volume basis and setting the median diameter as the average particle size by a laser diffraction scattering particle size distribution measuring apparatus. The measurement sample used was prepared by weighing 100mg of the inorganic filler and 10g of methyl ethyl ketone in a vial and dispersing them for 10 minutes by ultrasonic wave. The volume-based particle size distribution of component (a) was measured in a flow cell (flow cell) using a laser diffraction particle size distribution measuring apparatus with the wavelengths of the light source used being blue and red, and the average particle size as the median diameter was calculated from the obtained particle size distribution. Examples of the laser diffraction type particle size distribution measuring apparatus include "LA-960" manufactured by horiba, Ltd.

The component (a) is preferably treated with a surface treatment agent from the viewpoint of improving moisture resistance and dispersibility. Examples of the surface treatment agent include a vinyl silane coupling agent, (meth) acrylic acid coupling agent, fluorine-containing silane coupling agent, aminosilane coupling agent, epoxy silane coupling agent, mercapto silane coupling agent, alkoxysilane, organosilicon nitrogen compound, titanate coupling agent, and the like. Among these, from the viewpoint of remarkably obtaining the effect of the present invention, a vinyl silane-based coupling agent, (meth) acrylic acid-based coupling agent, and an aminosilane-based coupling agent are preferable, and an aminosilane-based coupling agent is more preferable. Further, 1 kind of the surface treatment agent may be used alone, or 2 or more kinds may be used in any combination.

Examples of commercially available surface-treating agents include "KBM 1003" (vinyltriethoxysilane), "KBM 503" (3-methacryloxypropyltriethoxysilane), and "KBM 403" (3-glycidoxypropyltrimethoxysilane), manufactured by shin-Etsu chemical Co., Ltd., "KBM 803" (3-mercaptopropyltrimethoxysilane), and "KBE 903" (3-aminopropyltriethoxysilane), manufactured by shin-Etsu chemical Co., Ltd., "KBM 573" (N-phenyl-3-aminopropyltrimethoxysilane), and "SZ-31" (hexamethyldisilazane), and "KBM 103" (phenyltrimethoxysilane), manufactured by shin-Etsu chemical Co., Ltd., "KBM-4803" (long-chain epoxy-type silane coupling agent), KBM-7103 (3,3, 3-trifluoropropyltrimethoxysilane) manufactured by shin-Etsu chemical industries, Ltd.

The degree of surface treatment with the surface treatment agent is preferably controlled within a predetermined range from the viewpoint of improving the dispersibility of the inorganic filler. Specifically, 100 parts by mass of the inorganic filler is preferably surface-treated with 0.2 to 5 parts by mass of the surface treatment agent, preferably 0.2 to 3 parts by mass, and preferably 0.3 to 2 parts by mass.

The degree of surface treatment with the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. The amount of carbon per unit surface area of the inorganic filler is preferably 0.02mg/m from the viewpoint of improving the dispersibility of the inorganic filler²Above, more preferably 0.1mg/m²Above, more preferably 0.2mg/m²The above. On the other hand, from the viewpoint of suppressing an increase in the melt viscosity of the resin varnish and the melt viscosity in the form of a sheet, 1mg/m is preferable²Less than, more preferably 0.8mg/m²The concentration is preferably 0.5mg/m or less²The following.

The amount of carbon per unit surface area of the inorganic filler can be measured after the surface-treated inorganic filler is washed with a solvent (e.g., Methyl Ethyl Ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent was added to the inorganic filler surface-treated with the surface treatment agent, and ultrasonic washing was performed at 25 ℃ for 5 minutes. After removing the supernatant liquid and drying the solid component, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. As the carbon analyzer, the one manufactured by horiba, Ltd, "EMIA-320V" and the like can be used.

From the viewpoint of remarkably obtaining the effect of the present invention, the content (mass%) of the component (a) is preferably 20 mass% or more, more preferably 30 mass% or more, further preferably 40 mass% or more, 50 mass% or more, preferably 95 mass% or less, more preferably 90 mass% or less, further preferably 85 mass% or less, and 80 mass% or less, when the nonvolatile component in the resin composition is taken as 100 mass%. In the present invention, the content of each component in the resin composition is a value when the nonvolatile component in the resin composition is 100 mass%, unless otherwise specified.

From the viewpoint of remarkably obtaining the effect of the present invention, the content (% by volume) of the component (a) is preferably 10% by volume or more, more preferably 30% by volume or more, further preferably 50% by volume or more, preferably 90% by volume or less, more preferably 85% by volume or less, further preferably 80% by volume or less, assuming that the nonvolatile content in the resin composition is 100% by volume.

< (b) curable resin

The resin composition may contain (b) a curable resin. As the curable resin (b), a curable resin that can be used when forming an insulating layer of a printed wiring board can be used, and a thermosetting resin is preferred.

Examples of the thermosetting resin include epoxy resins, phenol resins, naphthol resins, benzoxazine resins, active ester resins, cyanate ester resins, carbodiimide resins, amine resins, and acid anhydride resins. (b) The components may be used alone in 1 kind, or 2 or more kinds may be used in combination in an arbitrary ratio. Hereinafter, resins capable of reacting with an epoxy resin to cure a resin composition, such as phenol-based resins, naphthol-based resins, benzoxazine-based resins, active ester-based resins, cyanate ester-based resins, carbodiimide-based resins, amine-based resins, and acid anhydride-based resins, may be collectively referred to as "curing agent". The resin composition preferably contains an epoxy resin and a curing agent as the component (b) from the viewpoint of reducing the dielectric loss tangent.

Examples of the epoxy resin as the component (b) include a biscresol (bixylenol) type epoxy resin, a bisphenol a type epoxy resin, a bisphenol F type epoxy resin, a bisphenol S type epoxy resin, a bisphenol AF type epoxy resin, a dicyclopentadiene type epoxy resin, a trisphenol type epoxy resin, a naphthol novolac (naphthol novolac) type epoxy resin, a phenol novolac (phenol novolac) type epoxy resin, a tert-butyl catechol type epoxy resin, a naphthalene type epoxy resin, a naphthol type epoxy resin, an anthracene type epoxy resin, a glycidylamine type epoxy resin, a glycidyl ester type epoxy resin, a glycidylcyclohexane type epoxy resin, a cresol novolac (cresol novolac) type epoxy resin, a biphenyl type epoxy resin, a linear aliphatic epoxy resin, an epoxy resin having a butadiene structure, an alicyclic epoxy resin, a heterocyclic epoxy resin, a spiro ring-containing epoxy resin, a bis (phenol) having a butadiene structure, a bis (phenol novolac) type epoxy resin, a bis (phenol novolac) having a naphthalene structure, a bis (phenol novolac) type epoxy resin, a bis (phenol novolac) having a bis (phenol novolac) type epoxy resin, a bis (phenol novolac) having a bis (phenol epoxy resin, a bis (phenol novolac) type epoxy resin, a bis (phenol novolac) having a type epoxy resin, a bis (phenol novolac) and an epoxy resin, a bis (phenol epoxy resin, a bis (naphthalene type epoxy resin, an epoxy resin, a bis (phenol epoxy resin, an anthracene type epoxy resin, an anthracene type epoxy resin, an anthracene type an organic compound, an anthracene type epoxy resin, an organic compound, cyclohexane type epoxy resin, cyclohexane dimethanol type epoxy resin, naphthalene ether type epoxy resin, trimethylol type epoxy resin, tetraphenylethane type epoxy resin, phenol phthalimidine type epoxy resin, and the like. The epoxy resin may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

The resin composition preferably contains an epoxy resin having 2 or more epoxy groups in 1 molecule as the component (b). From the viewpoint of remarkably obtaining the desired effect of the present invention, the proportion of the epoxy resin having 2 or more epoxy groups in 1 molecule is preferably 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 70% by mass or more, relative to 100% by mass of the nonvolatile component of the component (b).

The epoxy resin includes an epoxy resin which is liquid at a temperature of 20 ℃ (hereinafter, sometimes referred to as "liquid epoxy resin") and an epoxy resin which is solid at a temperature of 20 ℃ (hereinafter, sometimes referred to as "solid epoxy resin"). The resin composition may contain only a liquid epoxy resin, only a solid epoxy resin, or a combination of a liquid epoxy resin and a solid epoxy resin as the component (b).

The liquid epoxy resin is preferably a liquid epoxy resin having 2 or more epoxy groups in 1 molecule.

The liquid epoxy resin is preferably a bisphenol a type epoxy resin, a bisphenol F type epoxy resin, a bisphenol AF type epoxy resin, a naphthalene type epoxy resin, a glycidyl ester type epoxy resin, a glycidyl amine type epoxy resin, a phenol novolac type epoxy resin, an alicyclic epoxy resin having an ester skeleton, a cyclohexane type epoxy resin, a cyclohexane dimethanol type epoxy resin, a glycidyl amine type epoxy resin, an epoxy resin having a butadiene structure, a glycidyl cyclohexane type epoxy resin, or a phenol phthalimidine type epoxy resin, and more preferably a bisphenol a type epoxy resin, a glycidyl cyclohexane type epoxy resin, or a phenol phthalimidine type epoxy resin.

Specific examples of the liquid epoxy resin include: "HP 4032", "HP 4032D" and "HP 4032 SS" (naphthalene epoxy resins) manufactured by DIC; "828 US", "jER 828 EL", "825", "Epikote 828 EL" (bisphenol A type epoxy resin) manufactured by Mitsubishi chemical company; "jER 807" and "1750" (bisphenol F type epoxy resin) manufactured by Mitsubishi chemical corporation; "jER 152" (phenol novolac type epoxy resin) manufactured by mitsubishi chemical corporation; "630" and "630 LSD" (glycidyl amine type epoxy resins) manufactured by mitsubishi chemical corporation; "ZX 1059" (a mixture of bisphenol A epoxy resin and bisphenol F epoxy resin) manufactured by Nippon iron Chemicals Co., Ltd.; "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX; "Celloxide 2021P" (alicyclic epoxy resin having an ester skeleton) manufactured by Dailuo corporation; "PB-3600" (epoxy resin having a butadiene structure) manufactured by Dailuo corporation; "ZX 1658" and "ZX 1658 GS" (liquid 1, 4-glycidylcyclohexane-type epoxy resins) manufactured by Nippon iron chemical Co., Ltd. These can be used alone in 1 kind, also can combine more than 2 kinds to use.

The solid epoxy resin is preferably a solid epoxy resin having 3 or more epoxy groups in 1 molecule, and more preferably an aromatic solid epoxy resin having 3 or more epoxy groups in 1 molecule.

The solid epoxy resin is preferably a biphenol-type epoxy resin, a naphthalene-type tetrafunctional epoxy resin, a cresol novolak-type epoxy resin, a dicyclopentadiene-type epoxy resin, a trisphenol-type epoxy resin, a naphthol-type epoxy resin, a biphenyl-type epoxy resin, a naphthalene ether-type epoxy resin, an anthracene-type epoxy resin, a bisphenol a-type epoxy resin, a bisphenol AF-type epoxy resin, or a tetraphenylethane-type epoxy resin, and more preferably a biphenyl-type epoxy resin, a biphenol-type epoxy resin, a tetraphenylethane-type epoxy resin, a naphthalene-type epoxy resin, or a naphthalene ether-type epoxy resin.

The solid epoxy resin is preferably a naphthalene type tetrafunctional epoxy resin, a cresol novolak type epoxy resin, a dicyclopentadiene type epoxy resin, a trisphenol type epoxy resin, a naphthol type epoxy resin, a biphenyl type epoxy resin, a naphthalene ether type epoxy resin, an anthracene type epoxy resin, a bisphenol a type epoxy resin, or a tetraphenylethane type epoxy resin, and more preferably a naphthalene type tetrafunctional epoxy resin, a naphthol type epoxy resin, or a biphenyl type epoxy resin. Specific examples of the solid epoxy resin include: "HP 4032H" (naphthalene type epoxy resin), "HP-4700", "HP-4710" (naphthalene type tetrafunctional epoxy resin), "N-690" (cresol novolak type epoxy resin), "N-695" (cresol novolak type epoxy resin), "HP-7200", "HP-7200 HH", "HP-7200H" (dicyclopentadiene type epoxy resin), "EXA-7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP 6000" (naphthalene ether type epoxy resin) manufactured by DIC; "EPPN-502H" (trisphenol type epoxy resin), "NC 7000L" (naphthol novolac type epoxy resin), "NC 3000H", "NC 3000L" and "NC 3100" (biphenyl type epoxy resin) manufactured by japan chemicals; ESN475V (naphthalene type epoxy resin) and ESN485 (naphthol novolac type epoxy resin) manufactured by Nippon iron chemical Co., Ltd; "YX 4000H", "YL 6121" (biphenyl type epoxy resin), "YX 4000 HK" (biphenol type epoxy resin), "YX 8800" (anthracene type epoxy resin) manufactured by Mitsubishi chemical company; PG-100 and CG-500 manufactured by Osaka gas chemical company, "YL 7760" (bisphenol AF epoxy resin), "YL 7800" (fluorene epoxy resin), "JeR 1010" (solid bisphenol A epoxy resin), and "JeR 1031S" (tetraphenylethane epoxy resin) manufactured by Mitsubishi chemical company; "WHR-991S" (phenol-phthalimidine type epoxy resin) manufactured by Nippon chemical Co., Ltd. These can be used alone in 1 kind, also can combine more than 2 kinds to use.

When a liquid epoxy resin and a solid epoxy resin are used in combination as the component (b), the amount ratio of these (liquid epoxy resin: solid epoxy resin) is preferably 1: 0.1-1: 20. more preferably 1: 0.3-1: 10. particularly preferably 1: 0.5-1: 5. when the amount ratio of the liquid epoxy resin to the solid epoxy resin is in this range, the desired effects of the present invention can be obtained. Further, when used in the form of a resin sheet with a support, the resin sheet generally provides a suitable level of adhesion. In addition, when used in the form of a resin sheet with a support, sufficient flexibility is usually obtained and handling properties are improved. Further, a cured product having a sufficient breaking strength can be usually obtained.

The epoxy equivalent of the epoxy resin as the component (b) is preferably 50g/eq to 5000g/eq, more preferably 50g/eq to 3000g/eq, still more preferably 80g/eq to 2000g/eq, and still more preferably 110g/eq to 1000g/eq. By setting the content in this range, a cured product having a sufficient crosslink density of a cured product of the resin composition can be provided. The epoxy equivalent is the mass of the epoxy resin containing 1 equivalent of the epoxy group. The epoxy equivalent can be measured according to JIS K7236.

The weight average molecular weight (Mw) of the epoxy resin as the component (b) is preferably 100 to 5000, more preferably 250 to 3000, and still more preferably 400 to 1500, from the viewpoint of remarkably obtaining the desired effect of the present invention. The weight average molecular weight of the epoxy resin is a weight average molecular weight in terms of polystyrene measured by a Gel Permeation Chromatography (GPC) method.

From the viewpoint of obtaining a cured product exhibiting good mechanical strength and insulation reliability, the content of the epoxy resin as the component (b) is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, assuming that the nonvolatile component in the resin composition is 100% by mass. The upper limit of the content of the epoxy resin is preferably 50% by mass or less, more preferably 45% by mass or less, and particularly preferably 40% by mass or less, from the viewpoint of remarkably obtaining the desired effect of the present invention.

The active ester resin as the component (b) may be a resin having 1 or more active ester groups in 1 molecule. Among them, as the active ester resin, preferred are resins having 2 or more ester groups having high reactivity in 1 molecule, such as phenol esters, thiophenol esters, N-hydroxylamine esters, and esters of heterocyclic hydroxy compounds. The active ester-based resin is preferably an active ester-based curing agent obtained by a condensation reaction of a carboxylic acid compound and/or a thiocarboxylic acid compound with a hydroxyl compound and/or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester resin obtained from a carboxylic acid compound and a hydroxyl compound is preferable, and an active ester resin obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound is more preferable.

Examples of the carboxylic acid compound include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid.

Examples of the phenol compound or naphthol compound include hydroquinone, resorcinol, bisphenol a, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol a, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, m-cresol, p-cresol, catechol, α -naphthol, β -naphthol, 1, 5-dihydroxynaphthalene, 1, 6-dihydroxynaphthalene, 2, 6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, trihydroxybenzene, dicyclopentadiene type diphenol compound, phenol novolac (phenol novolac), and the like. Here, the "dicyclopentadiene type diphenol compound" refers to a diphenol compound obtained by condensing a phenol 2 molecule with a dicyclopentadiene 1 molecule.

Preferred examples of the active ester-based resin include an active ester-based resin having a dicyclopentadiene type diphenol structure, an active ester-based resin having a naphthalene structure, an active ester-based resin having an acetyl compound of a phenol novolac resin, and an active ester-based resin having a benzoyl compound of a phenol novolac resin. Among them, active ester resins having a naphthalene structure and active ester resins having a dicyclopentadiene type diphenol structure are more preferable. The "dicyclopentadiene type diphenol structure" means a 2-valent structural unit containing a phenylene-dicyclopentene (ジシクロペンチレン) -phenylene group.

As commercially available active ester resins, active ester resins having a dicyclopentadiene type diphenol structure include "EXB 9451", "EXB 9460S", "HPC-8000-65T", "HPC-8000H-65 TM", "EXB-8000L-65 TM" (manufactured by DIC); examples of the active ester resin having a naphthalene structure include "EXB 9416-70 BK" and "EXB 8150-65T" (manufactured by DIC); examples of the active ester resin containing an acetylated novolak resin include "DC 808" (manufactured by Mitsubishi chemical corporation); examples of the active ester resin containing a benzoyl compound of a novolak resin include "YLH 1026" (manufactured by Mitsubishi chemical corporation); examples of the active ester resin of an acetylated novolak resin include "DC 808" (manufactured by Mitsubishi chemical corporation); examples of the active ester resin of the benzoyl compound of the novolak resin include "YLH 1026" (manufactured by mitsubishi chemical corporation), "YLH 1030" (manufactured by mitsubishi chemical corporation), and "YLH 1048" (manufactured by mitsubishi chemical corporation); and the like.

The phenol-based resin and the naphthol-based resin as the component (b) preferably have a phenolic structure (novolac structure) from the viewpoint of heat resistance and water resistance. From the viewpoint of adhesion to the conductor layer, a nitrogen-containing phenol-based curing agent is preferable, and a triazine skeleton-containing phenol-based resin is more preferable.

Specific examples of the phenol-based resin and naphthol-based resin include "MEH-7700", "MEH-7810", "MEH-7851" manufactured by Minghu chemical Co., Ltd, "NHN", "CBN", "GPH" manufactured by Nippon chemical Co., Ltd, "SN 170", "SN 180", "SN 190", "SN 475", "SN 485", "SN 495", "SN-495V", "SN 375", "SN 395 DIC", "TD-2090", "LA-7052", "LA-7054", "LA-1356", "LA-3018-50P" and "EXB-9500" manufactured by Nippon chemical Co., Ltd.

Specific examples of the benzoxazine-based resin as the component (b) include: JBZ-OD100 (benzoxazine ring equivalent 218), JBZ-OP100D (benzoxazine ring equivalent 218) and ODA-BOZ (benzoxazine ring equivalent 218) manufactured by JFE chemical company; "P-d" (benzoxazine ring equivalent 217) and "F-a" (benzoxazine ring equivalent 217) manufactured by four national chemical industries, Inc.; "HFB 2006M" (benzoxazine ring equivalent 432) manufactured by Showa Polymer Co.

Examples of the cyanate ester resin as the component (b) include bifunctional cyanate ester resins such as bisphenol a dicyanate, polyphenol cyanate ester, oligo (3-methylene-1, 5-phenylene cyanate ester), 4' -methylenebis (2, 6-dimethylphenyl cyanate ester), 4' -ethylenediphenyl dicyanate ester, hexafluorobisphenol a dicyanate ester, 2-bis (4-cyanate ester) phenylpropane, 1-bis (4-cyanate ester phenylmethane), bis (4-cyanate ester-3, 5-dimethylphenyl) methane, 1, 3-bis (4-cyanate ester phenyl-1- (methylethylidene)) benzene, bis (4-cyanate ester phenyl) sulfide, and bis (4-cyanate ester phenyl) ether, bifunctional cyanate ester resins such as bisphenol a dicyanate ester, poly (phenol) cyanate ester, oligo (3-methylene-1, 5-phenylene cyanate ester), 4' -ethylenebis (4-cyanate ester phenyl) ether, and the like, Polyfunctional cyanate ester resins derived from phenol novolac resins, cresol novolac resins, and the like, prepolymers in which a part of these cyanate ester resins is triazinized, and the like. Specific examples of cyanate ester resins include "PT 30", "PT 30S", and "PT 60" (phenol novolac type polyfunctional cyanate ester resin), "ULL-950S" (polyfunctional cyanate ester resin), "BA 230", "BA 230S 75" (prepolymer in which a part or all of bisphenol a dicyanate is triazinated to form a trimer), and "BADCy" (bisphenol a dicyanate) manufactured by Lonza japan.

Specific examples of the carbodiimide-based resin as the component (b) include: CARBODILITE (registered trademark) V-03 (carbodiimide equivalent: 216), V-05 (carbodiimide equivalent: 216), and V-07 (carbodiimide equivalent: 200) manufactured by Nisshinbo Chemicals; v-09 (carbodiimide equivalent: 200); stabaxol (registered trademark) P (carbodiimide equivalent: 302) manufactured by Rhein-Chemie.

The amine resin as the component (b) includes a resin having 1 or more amino groups in 1 molecule, and examples thereof include aliphatic amines, polyether amines, alicyclic amines, aromatic amines, and the like, and among them, aromatic amines are preferable from the viewpoint of achieving the desired effect of the present invention. The amine resin is preferably a primary amine or a secondary amine, and more preferably a primary amine. Specific examples of the amine-based curing agent include 4,4 '-methylenebis (2, 6-dimethylaniline), diphenyldiaminosulfone, 4' -diaminodiphenylmethane, 4 '-diaminodiphenylsulfone, 3' -diaminodiphenylsulfone, m-phenylenediamine, m-xylylenediamine, diethyltoluenediamine, 4 '-diaminodiphenyl ether, 3' -dimethyl-4, 4 '-diaminobiphenyl, 2' -dimethyl-4, 4 '-diaminobiphenyl, 3' -dihydroxybenzidine, 2-bis (3-amino-4-hydroxyphenyl) propane, 3-dimethyl-5, 5-diethyl-4, 4-diphenylmethanediamine, and, 2, 2-bis (4-aminophenyl) propane, 2-bis (4- (4-aminophenoxy) phenyl) propane, 1, 3-bis (3-aminophenoxy) benzene, 1, 3-bis (4-aminophenoxy) benzene, 1, 4-bis (4-aminophenoxy) benzene, 4' -bis (4-aminophenoxy) biphenyl, bis (4- (4-aminophenoxy) phenyl) sulfone, bis (4- (3-aminophenoxy) phenyl) sulfone and the like. As the amine-based resin, commercially available ones can be used, and examples thereof include "KAYABOND C-200S", "KAYABOND C-100", "KAYAHARD A-A", "KAYAHARD A-B", "KAYAHARD A-S" manufactured by Nippon chemical company, and "Epicure W" manufactured by Mitsubishi chemical company.

Examples of the acid anhydride resin as the component (b) include resins having 1 or more acid anhydride groups in 1 molecule. Specific examples of the acid anhydride-based resin include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride, hydrogenated methylnadic anhydride, trialkyltetrahydrophthalic anhydride, dodecenylsuccinic anhydride, 5- (2, 5-dioxotetrahydro-3-furanyl) -3-methyl-3-cyclohexene-1, 2-dicarboxylic anhydride, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic dianhydride, biphenyl tetracarboxylic dianhydride, naphthalene tetracarboxylic dianhydride, oxydiphthalic dianhydride, 3,3'-4,4' -diphenylsulfone tetracarboxylic dianhydride, 1,3,3a,4,5,9 b-hexahydro-5- (tetrahydro-2, 5-dioxo-3-furyl) -naphtho [1,2-C ] furan-1, 3-dione, ethylene glycol bis (anhydrotrimellitate), styrene-maleic acid resin obtained by copolymerizing styrene and maleic acid, and other polymer-type acid anhydrides.

The curing agent as the component (b) is preferably any one of a phenol-based resin, a naphthol-based resin, a benzoxazine-based resin, an active ester-based resin, a cyanate-based resin, a carbodiimide-based resin, an amine-based resin, and an anhydride-based resin, preferably any one of an active ester-based resin, a phenol-based resin, a carbodiimide-based resin, and a naphthol-based resin, and more preferably at least one selected from a phenol-based resin, an active ester-based resin, and a cyanate-based resin.

When the epoxy resin and the curing agent are contained as the component (b), the amount ratio of the epoxy resin to the total curing agent is represented by [ total count of epoxy groups of the epoxy resin ]: [ total number of reactive groups of curing agent ] is preferably 1: 0.01-1: 5, more preferably 1: 0.1-1: 3. more preferably 1: 0.3-1: 2. here, the "number of epoxy groups of the epoxy resin" refers to a value obtained by summing all values obtained by dividing the mass of nonvolatile components of the epoxy resin present in the resin composition by the epoxy equivalent weight. The "number of active groups of the curing agent" refers to a total value of all the values obtained by dividing the mass of nonvolatile components of the curing agent present in the resin composition by the equivalent of the active groups. When the amount ratio of the epoxy resin to the curing agent is in the above range as the component (b), a cured product having excellent flexibility can be obtained.

From the viewpoint of obtaining a cured product having excellent flexibility, the content of the curing agent as the component (b) is preferably 1% by mass or more, more preferably 3% by mass or more, further preferably 5% by mass or more, preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 20% by mass or less, relative to 100% by mass of nonvolatile components in the resin composition.

From the viewpoint of remarkably obtaining the effect of the present invention, the content of the component (b) is preferably 10% by mass or more, more preferably 13% by mass or more, further preferably 15% by mass or more, preferably 50% by mass or less, more preferably 45% by mass or less, further preferably 40% by mass or less, relative to 100% by mass of the nonvolatile component in the resin composition.

< (c) curing accelerator

The resin composition may contain (c) a curing accelerator as an optional component. Examples of the curing accelerator include a phosphorus-based curing accelerator, an amine-based curing accelerator, an imidazole-based curing accelerator, a guanidine-based curing accelerator, and a metal-based curing accelerator, and the amine-based curing accelerator and the imidazole-based curing accelerator are preferable, and the amine-based curing accelerator is more preferable. The curing accelerator may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

Examples of the phosphorus-based curing accelerator include triphenylphosphine, a phosphonium borate compound, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl) triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate and the like, with triphenylphosphine and tetrabutylphosphonium decanoate being preferred.

Examples of the amine-based curing accelerator include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4, 6-tris (dimethylaminomethyl) phenol, and 1, 8-diazabicyclo (5,4,0) -undecene, and preferably 4-dimethylaminopyridine and 1, 8-diazabicyclo (5,4,0) -undecene.

Examples of the imidazole-based curing accelerator include 2-methylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 1, 2-dimethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyanoethyl-2-ethyl-4-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 2-heptadecylimidazole, 1, 2-dimethylimidazole, 2-ethylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 2-dodecylimidazole, 2-dimethylimidazole, 2-ethylimidazole, 2-decylimidazole, 2-ethylimidazole, 1-naphthylimidazole, 2-methylimidazole, 2-dimethylimidazole, 2-ethylimidazole, and mixtures thereof, 1-cyanoethyl-2-undecylimidazolium trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2, 4-diamino-6- [2' -methylimidazolyl- (1') ] -ethyl-s-triazine, 2, 4-diamino-6- [2' -undecylimidazolyl- (1') ] -ethyl-s-triazine, 2, 4-diamino-6- [2' -ethyl-4 ' -methylimidazolyl- (1') ] -ethyl-s-triazine, 2, 4-diamino-6- [2' -methylimidazolyl- (1') ] -ethyl-s-triazine isocyanuric acid adduct, and mixtures thereof, Imidazole compounds such as 2-phenylimidazole isocyanuric acid adduct, 2-phenyl-4, 5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2, 3-dihydro-1H-pyrrolo [1,2-a ] benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2-methylimidazoline and 2-phenylimidazoline, and adducts of imidazole compounds with epoxy resins, preferably 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole.

As the imidazole-based curing accelerator, commercially available products such as "P200-H50" manufactured by Mitsubishi chemical company can be used.

Examples of the guanidine-based curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1- (o-tolyl) guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, tetramethylguanidine, pentamethylguanidine, 1,5, 7-triazabicyclo [4.4.0] dec-5-ene, 7-methyl-1, 5, 7-triazabicyclo [4.4.0] dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecyl biguanide, 1-dimethylbiguanide, 1-diethylbiguanide, 1-cyclohexylbiguanide, 1-allylbiguanide, 1-phenylbiguanide, 1- (o-tolyl) biguanide and the like, dicyandiamide, 1,5, 7-triazabicyclo [4.4.0] dec-5-ene are preferred.

Examples of the metal-based curing accelerator include organometallic complexes or organometallic salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of the organic metal complex include organic cobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organic copper complexes such as copper (II) acetylacetonate, organic zinc complexes such as zinc (II) acetylacetonate, organic iron complexes such as iron (III) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of the organic metal salt include zinc octylate, tin octylate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

The content of the (c) curing accelerator is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, particularly preferably 0.03% by mass or more, preferably 3% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less, assuming that the nonvolatile content in the resin composition is 100% by mass.

When the curing agent as the component (b) is not contained, the content of the curing accelerator (c) is preferably 0.01% by mass or more, more preferably 0.02% by mass or more, particularly preferably 0.03% by mass or more, preferably 3% by mass or less, more preferably 1% by mass or less, and particularly preferably 0.5% by mass or less, based on 100% by mass of nonvolatile components in the resin composition.

< (d) thermoplastic resin

The resin composition may contain (d) a thermoplastic resin as an optional component. Examples of the thermoplastic resin (d) include phenoxy resins, polyvinyl acetal resins, polyolefin resins, polyimide resins, polyamideimide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, polyphenylene ether resins, polyetheretherketone resins, and polyester resins, and phenoxy resins are preferred. The thermoplastic resin can be used alone in 1, or can also be combined with 2 or more.

(d) The polystyrene-equivalent weight average molecular weight of the thermoplastic resin is preferably 10000 or more, more preferably 15000 or more, and further preferably 20000 or more. The upper limit is preferably 100000 or less, more preferably 70000 or less, and further preferably 60000 or less. (d) The polystyrene-equivalent weight average molecular weight of the thermoplastic resin is measured by a Gel Permeation Chromatography (GPC) method. Specifically, the weight average molecular weight of the thermoplastic resin (d) in terms of polystyrene can be determined by using LC-9A/RID-6A manufactured by Shimadzu corporation as a measuring apparatus, Shodex K-800P/K-804L/K-804L manufactured by Showa Denko K.K., chloroform or the like as a mobile phase, at a column temperature of 40 ℃ and using a standard curve of standard polystyrene.

Examples of the phenoxy resin include phenoxy resins having 1 or more kinds of skeletons selected from a bisphenol a skeleton, a bisphenol F skeleton, a bisphenol S skeleton, a bisphenol acetophenone skeleton, a phenol skeleton, a biphenyl skeleton, a fluorene skeleton, a dicyclopentadiene skeleton, a norbornene skeleton, a naphthalene skeleton, an anthracene skeleton, an adamantane skeleton, a terpene skeleton, and a trimethylcyclohexane skeleton. The phenoxy resin may have any functional group such as a phenolic hydroxyl group or an epoxy group at its terminal. The phenoxy resin can be used singly or in combination of more than 2. Specific examples of the phenoxy resin include "1256" and "4250" (both phenoxy resins having a bisphenol a skeleton), and "YX 8100" (phenoxy resin having a bisphenol S skeleton), and "YX 6954" (phenoxy resin having a bisphenol acetophenone skeleton), which are manufactured by mitsubishi chemical corporation, and further include "FX 280" and "FX 293", which are manufactured by mitsubishi chemical corporation, "YL 7500BH 30", "YX 6954BH 30", "YX 7553BH 30", "YL 7553BH 30", "YL 7769BH 30", "YL 6794", "YL 7213", "YL 7290", and "YL 7482".

Examples of the polyvinyl acetal resin include polyvinyl formal resins and polyvinyl butyral resins, and polyvinyl butyral resins are preferred. Specific examples of the polyvinyl acetal resin include "electrochemical butyral 4000-2", "electrochemical butyral 5000-A", "electrochemical butyral 6000-C", "electrochemical butyral 6000-EP", S-LEC BH series, BX series (for example BX-5Z), KS series (for example KS-1), BL series, and BM series, which are manufactured by electrochemical industries, for example.

Specific examples of the polyimide resin include "RIKACOAT SN 20" and "RIKACOAT PN 20" manufactured by shin-shin chemical & chemical company. Specific examples of the polyimide resin include modified polyimides such as linear polyimides obtained by reacting a bifunctional hydroxyl-terminated polybutadiene, a diisocyanate compound and a tetrabasic acid anhydride (polyimides described in Japanese patent application laid-open Nos. 2006-37083), and polyimides having a polysiloxane skeleton (polyimides described in Japanese patent application laid-open Nos. 2002-12667 and 2000-319386).

Specific examples of the polyamide-imide resin include "VYLOMAX HR11 NN" and "VYLOMAX HR16 NN" manufactured by tokyo corporation. Specific examples of the polyamideimide resin include modified polyamideimides such as "KS 9100" and "KS 9300" (polyamideimide having a polysiloxane skeleton), which are manufactured by hitachi chemical industries, inc.

Specific examples of the polyether sulfone resin include "PES 5003P" manufactured by sumitomo chemical corporation. Specific examples of the polyphenylene ether resin include an oligophenylene ether-styrene resin "OPE-2 St 1200" manufactured by Mitsubishi gas chemical corporation. Specific examples of the polyether ether ketone resin include "sumiloy K" manufactured by sumitomo chemical corporation. Specific examples of the polyetherimide resin include "ULTEM" manufactured by GE corporation.

Specific examples of the polysulfone resin include polysulfones "P1700" and "P3500" manufactured by Solvay Advanced Polymers.

Examples of the polyolefin resin include ethylene copolymer resins such as low density polyethylene, ultra-low density polyethylene, high density polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, and ethylene-methyl acrylate copolymer; polyolefin elastomers such as polypropylene and ethylene-propylene block copolymers.

Examples of the polyester resin include polyethylene terephthalate resin, polyethylene naphthalate resin, polybutylene terephthalate resin, polybutylene naphthalate resin, polypropylene terephthalate resin, polypropylene naphthalate resin, polycyclohexanedimethyl terephthalate resin, and the like.

Among them, as the thermoplastic resin (d), phenoxy resin and polyvinyl acetal resin are preferable. Thus, in a suitable embodiment, the thermoplastic resin comprises one or more selected from the group consisting of phenoxy resins and polyvinyl acetal resins. Among them, the thermoplastic resin is preferably a phenoxy resin, and particularly preferably a phenoxy resin having a weight average molecular weight of 10,000 or more.

The content of the thermoplastic resin (d) is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and further preferably 0.5% by mass or more, assuming that the nonvolatile content in the resin composition is 100% by mass. The upper limit is preferably 5% by mass or less, more preferably 4% by mass or less, and further preferably 3% by mass or less.

< (e) elastomer

In addition to the above components, the resin composition may also use (e) an elastomer as an optional component. (e) The components can be used alone in 1 kind, or can be used in combination in more than 2 kinds.

The component (e) is preferably a resin having one or more structures selected from a polybutadiene structure, a polysiloxane structure, a poly (meth) acrylate structure, a polyalkylene structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyisobutylene structure, a polyester structure and a polycarbonate structure in a molecule, more preferably a resin having 1 or 2 or more structures selected from a polybutadiene structure, a poly (meth) acrylate structure, a polyalkyleneoxy structure, a polyisoprene structure, a polyester structure and a polycarbonate structure in a molecule, and still more preferably a resin having any one of a polybutadiene structure, a polyester structure and a polycarbonate structure in a molecule. It should be noted that "(meth) acrylate" is a term including methacrylate and acrylate and a combination thereof. These structures may be contained in the main chain of the elastomer molecule, or may be contained in the side chain.

From the viewpoint of remarkably obtaining the effect of the present invention, the component (e) is preferably a high molecular weight. (e) The number average molecular weight (Mn) of the component (a) is preferably 1,000 or more, more preferably 1500 or more, further preferably 3000 or more, 5000 or more. The upper limit is preferably 1,000,000 or less, more preferably 900,000 or less. The number average molecular weight (Mn) is a polystyrene-equivalent number average molecular weight measured by GPC (gel permeation chromatography).

From the viewpoint of remarkably obtaining the effect of the present invention, the glass transition temperature (Tg) of the component (e) is preferably low. (e) The glass transition temperature (Tg) of component (B) is preferably 30 ℃ or lower, more preferably 20 ℃ or lower, and still more preferably 10 ℃ or lower. Preferably-60 ℃ or higher, more preferably-50 ℃ or higher, and still more preferably-45 ℃ or higher.

The component (e) preferably has a functional group capable of reacting with the epoxy resin as the component (b) from the viewpoint of improving the peel strength by curing the resin composition by reacting with the epoxy resin as the component (b). The functional group that can react with the epoxy resin includes a functional group that appears by heating.

In one preferred embodiment, the functional group capable of reacting with the epoxy resin as the component (b) is one or more functional groups selected from the group consisting of a hydroxyl group, a carboxyl group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group and a urethane group. Among these, the functional group is preferably a hydroxyl group, an acid anhydride group, a phenolic hydroxyl group, an epoxy group, an isocyanate group, and a urethane group, more preferably a hydroxyl group, an acid anhydride group, a phenolic hydroxyl group, and an epoxy group, and particularly preferably a phenolic hydroxyl group. Among them, when an epoxy group is contained as a functional group, the weight average molecular weight (Mw) of the component (e) is preferably 5,000 or more.

(e) A suitable embodiment of the component (b) is a resin having a polybutadiene structure, and the polybutadiene structure may be contained in the main chain or in the side chain. It should be noted that the polybutadiene structure may be partially or fully hydrogenated. The resin having a polybutadiene structure is referred to as a polybutadiene resin.

Specific examples of the polybutadiene resin include "Ricon 130MA 8", "Ricon 130MA 13", "Ricon 130MA 20", "Ricon 131MA 5", "Ricon 131MA 10", "Ricon 131MA 17", "Ricon 131MA 20", "Ricon 184MA 6" (polybutadiene containing an acid anhydride group), "GQ-1000" (hydroxyl-and carboxyl-introduced polybutadiene) manufactured by Kazada, and "G-1000", "G-2000", "G-3000" (hydroxyl-terminated polybutadiene), and "GI-1000", "GI-2000", "GI-3000" (hydroxyl-terminated hydrogenated polybutadiene), and "FCA-061L" (hydrogenated polybutadiene skeleton epoxy resin) manufactured by Nagase ChemteX. One embodiment includes a linear polyimide (polyimide described in jp 2006-37083 a and international publication No. 2008/153208 a) using hydroxyl-terminated polybutadiene, a diisocyanate compound, and a tetrabasic acid anhydride as raw materials, and a phenolic hydroxyl group-containing butadiene. The content of the butadiene structure in the polyimide resin is preferably 60 to 95% by mass, and more preferably 75 to 85% by mass. The polyimide resin can be described in detail in Japanese patent laid-open No. 2006-37083 and International publication No. 2008/153208, which are incorporated herein by reference.

(e) A suitable embodiment of component (a) is a resin containing a poly (meth) acrylate structure. A resin containing a poly (meth) acrylate structure is referred to as a poly (meth) acrylic resin. Examples of the poly (meth) acrylic resin include Teisanrein, manufactured by Nagase ChemteX, ME-2000, W-116.3, W-197C, KG-25 and KG-3000, manufactured by Kokusan Kogyo Co.

(e) A suitable embodiment of component (B) is a resin containing a polycarbonate structure. A resin containing a polycarbonate structure is referred to as a polycarbonate resin. Examples of the polycarbonate resin include "T6002" and "T6001" (polycarbonate diols) manufactured by Asahi Kasei Chemicals, and "C-1090", "C-2090" and "C-3090" (polycarbonate diols) manufactured by Cola. In addition, linear polyimides produced from a hydroxyl-terminated polycarbonate, a diisocyanate compound and a tetrabasic acid anhydride can also be used. The content of the carbonate structure in the polyimide resin is preferably 60 to 95% by mass, and more preferably 75 to 85% by mass. The polyimide resin can be described in detail in International publication No. 2016/129541, which is incorporated herein.

Further, another embodiment of the component (e) is a resin having a polysiloxane structure. Resins containing polysiloxane structures are referred to as silicone resins. Examples of the silicone resin include "SMP-2006", "SMP-2003 PGMEA", "SMP-5005 PGMEA", and linear polyimides produced from an amino-terminated polysiloxane and a tetrabasic acid anhydride (International publication No. 2010/053185, Japanese patent application laid-open Nos. 2002-12667 and 2000-319386).

(e) Other embodiments of the component (a) are resins having a polyalkylene structure or a polyalkyleneoxy structure. The resin containing a polyalkylene structure is referred to as a polyalkylene resin, and the resin containing a polyalkyleneoxy structure is referred to as a polyalkyleneoxy resin. The polyalkyleneoxy structure is preferably a polyalkyleneoxy structure having 2 to 15 carbon atoms, more preferably a polyalkyleneoxy structure having 3 to 10 carbon atoms, and still more preferably a polyalkyleneoxy structure having 5 to 6 carbon atoms. Specific examples of the polyalkylene resin and the polyalkyleneoxy resin include "PTXG-1000" and "PTXG-1800" manufactured by Asahi chemical fiber company.

(e) Other embodiments of component (b) are resins containing a polyisoprene structure. A resin having a polyisoprene structure is referred to as a polyisoprene resin. Specific examples of the polyisoprene resin include "KL-610" and "KL 613" manufactured by Coli.

(e) Another embodiment of component (B) is a resin having a polyisobutylene structure. A resin having a polyisobutylene structure is referred to as a polyisobutylene resin. Specific examples of the polyisobutylene resin include "SIBSTAR-073T" (styrene-isobutylene-styrene triblock copolymer) and "SIBSTAR-042D" (styrene-isobutylene diblock copolymer) manufactured by KANEKA, Inc.

(e) A suitable embodiment of component (a) is a resin containing a polyester structure. A resin having a polyester structure is referred to as a polyester resin. Examples of the polyester resin include "Vylon 600", "Vylon 560", "Vylon 230", "Vylon GK-360", "Vylon BX-1001" manufactured by Toyobo Co., Ltd, "LP-035", "LP-011", "TP-220", "TP-249", and "SP-185" manufactured by Mitsubishi chemical Co., Ltd.

From the viewpoint of remarkably obtaining the effect of the present invention, the content of the elastomer (e) is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 15% by mass or more, assuming that the nonvolatile content in the resin composition is 100% by mass. The upper limit is preferably 50% by mass or less, more preferably 45% by mass or less, and further preferably 40% by mass or less.

< (f) other additives

In addition to the above components, the resin composition may further contain other additives as optional components. Examples of such additives include flame retardants; an organic filler material; organic metal compounds such as organic copper compounds, organic zinc compounds, and organic cobalt compounds; a thickener; defoaming agents; leveling agent; an adhesion imparting agent; a colorant and the like. These additives may be used alone in 1 kind, or may be used in combination of 2 or more kinds in an arbitrary ratio.

Examples of the flame retardant include phosphazene compounds, organic phosphorus flame retardants, organic nitrogen-containing phosphorus compounds, nitrogen compounds, organosilicon flame retardants, and metal hydroxides, and phosphazene compounds are preferable. The flame retardant may be used alone in 1 kind or in combination of 2 or more kinds.

The phosphazene compound is not particularly limited as long as it is a cyclic compound having nitrogen and phosphorus as constituent elements, and is preferably a phosphazene compound having a phenolic hydroxyl group.

Specific examples of the phosphazene compound include "SPH-100", "SPS-100", "SPB-100", "SPE-100" manufactured by Otsuka chemical Co., Ltd, "FP-100", "FP-110", "FP-300", "FP-400" manufactured by Kotsuka pharmaceutical Co., Ltd, and preferably "SPH-100" manufactured by Otsuka chemical Co., Ltd.

As the flame retardant other than the phosphazene compound, commercially available products can be used, and examples thereof include "HCA-HQ" manufactured by Sanko and "PX-200" manufactured by Daihachi chemical industries, Ltd. As the flame retardant, those which are difficult to hydrolyze are preferred, and examples thereof include 10- (2, 5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide and the like.

The content of the flame retardant is preferably 0.1% by mass or more, more preferably 0.2% by mass or more, and still more preferably 0.3% by mass or more, assuming that the nonvolatile content in the resin composition is 100% by mass. The upper limit is preferably 15% by mass or less, more preferably 10% by mass or less, and further preferably 5% by mass or less.

As the organic filler, any organic filler that can be used when forming an insulating layer of a printed wiring board can be used, and examples thereof include rubber particles, polyamide fine particles, silicone particles, and the like. As the rubber particles, commercially available products such as "EXL 2655" manufactured by Nippon Dow chemical Co., Ltd "," AC3401N "manufactured by AICA industries, and" AC3816N "can be used. The organic filler may be used alone in 1 kind, or may be used in combination in 2 or more kinds.

The content of the organic filler is preferably 0.1% by mass or more, more preferably 0.15% by mass or more, and still more preferably 0.2% by mass or more, assuming that the nonvolatile content in the resin composition is 100% by mass. The upper limit is preferably 10% by mass or less, more preferably 5% by mass or less, and further preferably 3% by mass or less.

The method for producing the resin composition is not particularly limited, and examples thereof include a method in which the compounding ingredients are mixed and dispersed together with a solvent and the like by a rotary mixer or the like as necessary.

[ resin sheet with support ]

The resin sheet with a support comprises a support and a resin composition layer formed of a resin composition provided on the support. The resin composition is as described in the column [ resin composition ].

The thickness of the resin composition layer is preferably 150 μm or less, more preferably 100 μm or less, and even more preferably 50 μm or less, from the viewpoint of thinning of the printed wiring board and providing a cured product having excellent insulation properties even if the cured product of the resin composition is a thin film. The lower limit of the thickness of the resin composition layer is not particularly limited, and may be usually 1 μm or more and 5 μm or more.

Examples of the support include a film made of a plastic material, a metal foil, and a release paper, and preferably a film made of a plastic material and a metal foil.

When a film made of a plastic material is used as the support, examples of the plastic material include polyesters such as polyethylene terephthalate (hereinafter, sometimes simply referred to as "PET") and polyethylene naphthalate (hereinafter, sometimes simply referred to as "PEN"), acrylic polymers such as polycarbonate (hereinafter, sometimes simply referred to as "PC") and polymethyl methacrylate (PMMA), cyclic polyolefins, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimide. Among these, polyethylene terephthalate and polyethylene naphthalate are preferable, and particularly, inexpensive polyethylene terephthalate is preferable.

When a metal foil is used as the support, examples of the metal foil include a copper foil and an aluminum foil, and a copper foil is preferable. As the copper foil, a foil made of a single metal of copper may be used, and a foil made of an alloy of copper and another metal (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, or the like) may be used.

The surface of the support to be bonded to the resin composition layer may be subjected to matting treatment, corona treatment, or antistatic treatment.

As the support, a support with a release layer having a release layer on the surface bonded to the resin composition layer can be used. Examples of the release agent used for the release layer of the support with a release layer include 1 or more release agents selected from alkyd resins, polyolefin resins, polyurethane resins, and silicone resins. As the support with a releasing layer, commercially available products can be used, and examples thereof include a PET film having a releasing layer containing an alkyd resin-based releasing agent as a main component, such as "SK-1", "AL-5", "AL-7" manufactured by Lindcaceae, "Lumiror T60" manufactured by Toray, a "Purex" manufactured by Ditikon, and a "Unipel" manufactured by UNITIKA; "U2-NR 1" manufactured by Dupont Film Co., Ltd.; and the like.

The thickness of the support is not particularly limited, but is preferably in the range of 5 to 75 μm, and more preferably in the range of 10 to 60 μm. When a support with a release layer is used, the thickness of the entire support with a release layer is preferably within the above range.

In one embodiment, the resin sheet with a support may further contain other layers as necessary. Examples of the other layer include a protective film selected for the support and provided on the surface of the resin composition layer not bonded to the support (i.e., the surface opposite to the support). The thickness of the protective film is not particularly limited, and is, for example, 1 μm to 40 μm. By laminating the protective film, adhesion of dust or the like on the surface of the resin composition layer and generation of scratches can be suppressed.

The resin sheet with a support can be produced, for example, by dissolving a resin composition in an organic solvent to prepare a resin varnish, applying the resin varnish onto the support using a die coater or the like, and drying the resin varnish to form a resin composition layer.

Examples of the organic solvent include ketones such as acetone, Methyl Ethyl Ketone (MEK), and cyclohexanone; acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate; carbitols such as cellosolve and butyl carbitol; aromatic hydrocarbons such as toluene and xylene; amide solvents such as dimethylformamide, dimethylacetamide (DMAc) and N-methylpyrrolidone. The organic solvent may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

The drying can be carried out by a known method such as heating or blowing hot air. The drying conditions are not particularly limited, and the drying is performed so that the content of the organic solvent in the resin composition layer becomes 10 mass% or less, preferably 5 mass% or less. The boiling point of the organic solvent in the resin varnish varies, and when a resin varnish containing 30 to 60 mass% of the organic solvent is used, for example, the resin composition layer can be formed by drying at 50 to 150 ℃ for 3 to 10 minutes.

The resin sheet with the support can be stored in a roll form. When the resin sheet with a support has a protective film, the protective film can be peeled off and used.

[ method for manufacturing printed Wiring Board ]

The method for manufacturing a printed wiring board of the present invention sequentially comprises:

(A) a step of forming an opening in an insulating layer containing a cured product of a resin composition by laser, and

(B) and a step of forming a through hole by performing a blasting process using abrasive grains on the opening.

As described above, as a method of forming a via hole in an insulating layer, a method using a laser is considered. When the via hole is formed using only laser light, a halo phenomenon may occur due to heat generated by laser light irradiation. Further, in addition to a method of forming a through hole using a laser, there is a method of forming a through hole by sand blast processing. If the through-hole is formed by only the blast treatment, the occurrence of the halo phenomenon can be suppressed, but it is difficult to form a through-hole having a small diameter, and the processing speed of the through-hole may be slow.

In the present invention, first, an opening is formed in an insulating layer by a laser, and then a through hole is formed by blasting abrasive grains against the bottom surface of the opening, whereby a small-diameter through hole can be formed, stain removability is excellent, and occurrence of a halo phenomenon can be suppressed. Further, since the opening portion which is a part of the through hole is formed by the laser light without forming the whole of the through hole, the number of shots (shots) of the laser light can be reduced. Further, since the through hole is formed by the blast treatment in the opening portion formed by the laser, deterioration of the resin in the periphery of the bottom portion of the through hole can be suppressed, so that occurrence of the halo phenomenon can be suppressed, and the processing time (through hole processability) can also be shortened.

The method for manufacturing a printed wiring board before the step (a) may include:

(1) a step of preparing an inner layer circuit board, and

(3) a step of forming an insulating layer on a main surface of the inner layer circuit board;

further, in order to be used for the formation of the insulating layer in the aforementioned process (3), the method for manufacturing a printed wiring board may further include:

(2) a step of preparing a resin sheet with a support, the resin sheet with a support comprising a support and a resin composition layer formed of a resin composition provided on the support. Hereinafter, each step of the method for manufacturing a printed wiring board will be described.

< Process (1) >

The step (1) is a step of preparing an inner layer circuit board. The inner circuit substrate generally has a support substrate and a metal layer provided on a surface of the support substrate. The metal layer is exposed to the main surface of the inner layer circuit board, and a through hole is formed in a region where the metal layer is present. Therefore, the region where the through hole is formed on the main surface of the inner layer circuit substrate is formed of the metal layer.

Examples of the material of the support substrate include a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, and the like. Examples of the material of the metal layer include a copper foil, a copper foil with a carrier, and a material of a conductor layer described later, and a copper foil is preferable.

The arithmetic average roughness (Ra) of the main surface of the inner layer circuit board is preferably 500nm or less, more preferably 450nm or less, and still more preferably 400nm or less and 350nm or less. By setting the arithmetic mean roughness (Ra) of the main surface of the inner layer circuit board to 500nm or less, the insulating layer formed on the main surface can be suppressed from entering deep into the inner layer circuit board, and the workability of the through hole can be improved. The lower limit is not particularly limited, but is preferably 10nm or more, more preferably 50nm or more, and further preferably 100nm or more. The arithmetic average roughness (Ra) of the main surface is a value measured in accordance with ISO 25178, and can be measured using a non-contact surface roughness meter. The main surface of the inner layer circuit board represents the surface of the inner layer circuit board on which the insulating layer is provided.

When the arithmetic mean roughness (Ra) is not constant on the main surface, the arithmetic mean roughness (Ra) of the main surface in the region where the metal layer is formed may be in the above range, and the arithmetic mean roughness (Ra) of the main surface in the region where the through hole is formed is preferably in the above range.

The ten-point average roughness (Rz) of the main surface of the inner layer circuit board is preferably 5000nm or less, more preferably 4500nm or less, and still more preferably 4000nm or less. By setting the ten-point average roughness (Rz) of the main surface of the inner layer circuit board to 5000nm or less, the insulating layer formed on the main surface can be suppressed from entering deep into the inner layer circuit board, and the insulation reliability can be improved. The lower limit is not particularly limited, but is preferably 50nm or more, more preferably 100nm or more, and further preferably 1000nm or more. The ten-point average roughness (Rz) of the main surface is a value measured in accordance with ISO 25178, and can be measured using a non-contact surface roughness meter.

When the ten-point average roughness (Rz) on the main surface is not constant, the ten-point average roughness (Rz) on the main surface of the region where the metal layer is formed is preferably within the above range, and more preferably within the above range.

The main surface of the inner layer circuit board can be adjusted to the above range in arithmetic average roughness (Ra) and ten-point average roughness (Rz) by, for example, etching treatment or polishing.

< Process (2) >

The step (2) is a step of preparing a resin sheet with a support, which includes a support and a resin composition layer formed of a resin composition provided on the support. The resin sheet with a support is as described above.

< Process (3) >

The step (3) is a step of forming an insulating layer on the main surface of the inner layer circuit board. In the step (3), for example, a resin composition layer of the resin sheet with a support is laminated on the main surface of the inner layer circuit board, and the resin composition layer is thermally cured to form the insulating layer.

As shown in fig. 1, the inner-layer circuit board 10 includes a support board 11 and a metal layer 12 provided on a surface of the support board 11. In step (3), a resin sheet (not shown) with a support is laminated on the main surface 10a of the inner layer circuit board 10, and the insulating layer 22 is formed by thermally curing the resin composition layer. Since the insulating layer 22 is usually provided on the surface of the metal layer 12, the surface of the metal layer 12 opposite to the surface on the support substrate 11 side is the main surface 10 a. In fig. 1, the metal layer 12 is provided on one surface of the support substrate 11, but may be provided on both surfaces of the support substrate 11.

The lamination of the inner-layer circuit board and the resin sheet with a support body can be performed, for example, by heat-crimping the resin sheet with a support body to the inner-layer circuit board from the support body side. Examples of the member for heat-pressure bonding the resin sheet with the support onto the inner circuit board (hereinafter, also referred to as "heat-pressure bonding member") include a heated metal plate (SUS end plate or the like) and a metal roll (SUS roll). It should be noted that, instead of pressing the heat-pressure-bonding member directly against the resin sheet with a support, it is preferable to press the resin sheet with a support via an elastic material such as heat-resistant rubber so that the resin sheet with a support sufficiently follows the surface irregularities of the inner circuit board.

The lamination of the inner circuit board and the resin sheet with a support may be performed by a vacuum lamination method. In the vacuum lamination method, the heating and pressure bonding temperature is preferably 60 to 160 ℃, more preferably 80 to 140 ℃, the heating and pressure bonding pressure is preferably 0.098 to 1.77MPa, more preferably 0.29 to 1.47MPa, and the heating and pressure bonding time is preferably 20 to 400 seconds, more preferably 30 to 300 seconds. The lamination is preferably performed under a reduced pressure of 26.7hPa or less.

The lamination may be performed by a commercially available vacuum laminator. Examples of commercially available vacuum laminators include vacuum pressure laminators manufactured by machine manufacturers, vacuum applicators manufactured by Nikko-Materials, and batch vacuum pressure laminators.

After the lamination, the heat-pressure bonded member is pressed at normal pressure (atmospheric pressure), for example, from the support side, whereby the smoothing treatment of the laminated resin sheet with the support can be performed. The pressing conditions for the smoothing treatment may be the same as the above-described conditions for the heat and pressure bonding of the laminate. The smoothing treatment may be performed by a commercially available laminator. The lamination and smoothing treatment can be continuously performed using the above-mentioned commercially available vacuum laminator.

After the resin sheet with the support is laminated on the inner-layer circuit board, the resin composition layer is thermally cured to form the insulating layer. The conditions for heat curing of the resin composition layer are not particularly limited, and the conditions generally used in forming an insulating layer of a printed wiring board can be used.

For example, the heat curing conditions of the resin composition layer vary depending on the kind of the resin composition, and the curing temperature is preferably 120 to 240 ℃, more preferably 150 to 220 ℃, and still more preferably 170 to 210 ℃. The curing time may be preferably 5 to 120 minutes, more preferably 10 to 100 minutes, and still more preferably 15 to 100 minutes.

Before the resin composition layer is thermally cured, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, before the resin composition layer is thermally cured, the resin composition layer may be preheated at a temperature of 50 ℃ or more and less than 120 ℃ (preferably 60 ℃ or more and 115 ℃ or less, more preferably 70 ℃ or more and 110 ℃ or less) for 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes, and further preferably 15 minutes to 100 minutes).

From the viewpoint of forming a small-diameter through hole, the thickness of the insulating layer is 25 μm or less, preferably 20 μm or less, more preferably 15 μm or less, and still more preferably 10 μm or less. The lower limit of the thickness of the insulating layer is not particularly limited, and may be usually 1 μm or more and 5 μm or more.

In step (3), instead of using a resin sheet, the resin composition may be directly applied to the main surface of the inner layer circuit board to form the insulating layer. The conditions for forming the insulating layer at this time are the same as those for forming the insulating layer using the resin sheet with a support.

From the viewpoint of improving the through-hole processability, the insulating layer obtained by curing the resin composition layer at 200 ℃ for 90 minutes has a modulus of elasticity at 23 ℃ of preferably 0.1GPa or more, more preferably 1GPa or more, more preferably 3GPa or more, preferably 30GPa or less, more preferably 25GPa or less, and still more preferably 20GPa or less. The elastic modulus can be measured by the method described in the examples below.

The support may be removed after the resin sheets with the support are stacked and before thermosetting, after the step (a) is completed, or after the resin sheets with the support are stacked and thermosetting, or after the resin sheets with the support are used as a mask in the blasting treatment in the step (B).

< step (A) >

The step (a) is a step of forming an opening in an insulating layer containing a cured product of the resin composition by a laser beam. As one embodiment of the step (a), as shown in fig. 2, the insulating layer 22 formed on the main surface 10a of the inner layer circuit board 10 is irradiated with laser light to form the opening 30.

The laser beam is preferably irradiated in a state where a mask for blasting is provided on the insulating layer 22. Therefore, the step (a) may include a step of forming a mask on the insulating layer 22 before the irradiation of the laser beam. Examples of the mask include a dry film, a metal foil, and a combination thereof. These masks can be provided on the insulating layer 22 by, for example, laminating either a dry film or a metal foil on the insulating layer after peeling off the support.

The dry film is preferably a dry film patterned by exposure and development, and more preferably a film resistant to sandblasting in the step (B) described later. As the dry film, a photosensitive dry film formed from a photoresist composition can be used. As such a dry film, for example, a dry film formed from a resin such as a novolac resin or an acrylic resin can be used.

Examples of the metal foil include copper foil and aluminum foil, and copper foil is preferable. As the copper foil, a foil made of a single metal of copper may be used, and a foil made of an alloy of copper and another metal (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, or the like) may be used.

The thickness of the dry film mask is preferably 10 μm or more, more preferably 15 μm or more, further preferably 20 μm or more, preferably 100 μm or less, more preferably 70 μm or less, and further preferably 50 μm or less, from the viewpoint of improving the workability of the through hole.

The thickness of the mask such as a metal foil is preferably 1 μm or more, more preferably 2 μm or more, further preferably 3 μm or more, preferably 40 μm or less, more preferably 20 μm or less, and further preferably 15 μm or less, from the viewpoint of improving the processability of the through hole.

As the mask, the support 21 can be used. When the support 21 is used as the mask, a step of providing a mask different from the support 21 can be omitted, and thus the manufacturing method can be simplified. In the present embodiment, as shown in fig. 2, an example in which the support 21 is used as a mask will be described.

The depth a of the opening is preferably 50% or more, more preferably 60% or more, and even more preferably 70% or more of the thickness of the insulating layer, from the viewpoint of remarkably obtaining the effect of the present invention. The upper limit is preferably 95% or less, more preferably 90% or less, and still more preferably 85% or less of the thickness of the insulating layer. The depth of the opening is a distance from the surface (support 21 in fig. 2) of the insulating layer on the side contacting the mask to the bottom of the opening. The depth of the opening can be determined by observing the cross section of the difference between the non-processed portion and the deepest portion of the processed portion of the insulating layer and calculating the depth.

The opening diameter b of the opening portion may be the opening diameter of the through hole (through hole diameter). The opening diameter b is preferably 100 μm or less, more preferably 75 μm or less, and still more preferably 55 μm or less, and is preferably 5 μm or more, more preferably 10 μm or more, and still more preferably 15 μm or more, from the viewpoint of forming a through hole having a small diameter. Note that, as shown in fig. 2, the opening diameter b represents the diameter at the upper end of the insulating layer 22.

The ratio of the depth a of the opening to the opening diameter b of the opening (depth a of the opening/opening diameter b of the opening) is preferably 0.1 or more, more preferably 0.3 or more, further preferably 0.5 or more, preferably 3 or less, more preferably 1 or less, and further preferably 0.7 or less, from the viewpoint of remarkably obtaining the effect of the present invention.

Examples of the laser light source that can be used for forming the opening include CO₂Laser (carbon dioxide laser), UV-YAG laser, UV laser, YAG laser, excimer laser, and the like. Among them, CO is preferable from the viewpoint of processing speed and cost₂Laser or UV-YAG laser.

Irradiation of CO₂The number of emissions of the laser beam is preferably 2 or less, and more preferably 1, from the viewpoint of improving the through-hole workability. In order to make the number of emissions within the above range,preference is given to using CO₂The energy and pulse width of the laser light are set to be equal to or more than a predetermined value. CO 2₂The energy of the laser is preferably 0.3W or more, more preferably 0.5W or more, further preferably 1.0W or more, preferably 30W or less, more preferably 20W or less, further preferably 15W or less. In addition, CO₂The pulse width of the laser light is preferably 3 μ sec or more, more preferably 5 μ sec or more, further preferably 8 μ sec or more, preferably 40 μ sec or less, more preferably 30 μ sec or less, further preferably 20 μ sec or less.

The number of emissions when irradiated with the UV-YAG laser is preferably 20 or less, more preferably 15, from the viewpoint of improving the through-hole processability. In order to set the number of emissions within the above range, the energy and pulse width of the UV-YAG laser are preferably set to a predetermined value or more. The energy of the UV-YAG laser is preferably 0.05W or more, more preferably 0.10W or more, further preferably 0.15W or more, preferably 20W or less, more preferably 10W or less, further preferably 5W or less.

The formation of the through-hole can be carried out using a commercially available laser apparatus. Examples of commercially available carbon dioxide laser devices include "LC-2E 21B/1C" manufactured by Hitachi Asia machinery, "ML 605 GTWII" manufactured by Mitsubishi Motor, and substrate drilling laser processing machines manufactured by Panasonic Welding Systems. Examples of the UV-YAG laser device include "LU-2L 212/M50L" manufactured by Vickers, Inc.

In step (a), as described above, the insulating layer 22 provided with the mask such as the support 21 is preferably irradiated with laser light to form the opening 30. Therefore, the opening 30 is preferably formed so as to communicate with not only the insulating layer 22 but also the mask. Therefore, as in the example shown in fig. 2, when the support 21 is used as a mask, the opening 30 can be formed continuously with the insulating layer 22 and the support 21. In this case, from the viewpoint of remarkably obtaining the effect of the present invention, the ratio (total value c/opening diameter) of the total value c of the thickness of the mask (the thickness of the support 21 in fig. 2) and the depth a of the opening to the opening diameter of the through hole formed in the step (B) is preferably 3 or less, more preferably 2.5 or less, further preferably 2 or less, and preferably 0.1 or more, more preferably 0.3 or more, and further preferably 0.5 or more. Here, the thickness of the mask is the thickness of the mask before the step (B) is performed.

From the viewpoint of remarkably obtaining the effect of the present invention, the ratio (total value c/opening diameter B) of the total value c of the thickness of the mask and the depth a of the opening to the opening diameter B of the opening 30 before the step (B) is preferably 3 or less, more preferably 2.5 or less, further preferably 2 or less, preferably 0.1 or more, more preferably 0.3 or more, and further preferably 0.5 or more.

The total value c of the thickness of the mask and the depth of the opening is preferably 50% or more, more preferably 60% or more, and even more preferably 70% or more of the total thickness of the mask and the insulating layer, from the viewpoint of remarkably obtaining the effect of the present invention. The upper limit is preferably 95% or less, more preferably 90% or less, and still more preferably 80% or less of the total thickness of the mask and the insulating layer.

< Process (B) >

The step (B) is a step of forming a through hole by performing blasting using abrasive grains on the opening. As a detailed embodiment of the step (B), the through-hole is formed by causing the abrasive grains to collide with the bottom surface of the opening through the mask. The mask is preferably at least one of a support, a dry film, and a metal foil which are opened in the step (a), and more preferably a support.

In the step (B), a blast treatment is performed to form the through-hole 40 by causing abrasive grains to collide with the bottom surface of the opening 30 (i.e., the exposed surface of the insulating layer) as shown in fig. 2 (an example of the through-hole after formation is shown in fig. 3). Here, the blasting treatment means the following treatment: abrasive grains or a slurry solution of abrasive grains are ejected from a nozzle to the surface of a portion not covered with a mask such as a support, a dry film, or a metal foil by air ejected at a predetermined pressure, and the abrasive grains are caused to collide with the insulating layer, thereby forming a through hole. The blasting treatment in the step (B) may be either a dry blasting treatment for blasting abrasive grains or a wet blasting treatment for blasting a slurry solution of abrasive grains, and is preferably a wet blasting treatment from the viewpoint of forming a small-diameter through hole.

The corrected mohs hardness of the abrasive grains used for the blasting is preferably 1 or more, more preferably 5 or more, and even more preferably 6 or more, and 7 or more, from the viewpoint of forming a small-diameter through hole by the blasting. The upper limit value may be set to 15 or less, for example. The modified mohs hardness of the abrasive particles can be measured using, for example, a mohs hardness meter.

Examples of the abrasive grains include inorganic compounds such as silica and glass; metal compounds such as steel, stainless steel, zinc, and copper; ceramics such as garnet, zirconia, silicon carbide, alumina, and boron carbide; and particles containing dry ice as a main component. Among them, from the viewpoint of remarkably obtaining the desired effect of the present invention, inorganic compounds and ceramics are preferable, and any of alumina, silicon carbide, and silica is preferable. The silica is preferably crystalline silica.

The abrasive grains may be commercially available. Examples of commercially available products include "DAW-03" manufactured by Denka and "AY 2-75" manufactured by Nikkai chemical Co., Ltd. (alumina); "GP # 4000" and "SER-A06" (silicon carbide) manufactured by concentrated electric refining; "IMSIL A-8" (crystalline silica) manufactured by Longson; "FUJIRUNDUM WA" (fused alumina) manufactured by Fujirundium corporation WAs not prepared.

The abrasive grains have an average particle diameter of 0.5 μm or more, preferably 1 μm or more, and more preferably 2 μm or more. When the lower limit of the average particle diameter of the abrasive grains is within this range, the through-hole workability can be improved. Further, the back-blasting of abrasive grains in the blasting treatment can be suppressed, and the grinding of the mask can be suppressed. The back-jetting of the abrasive grains is a phenomenon in which the impact speed of the abrasive grains jetted to the opening is reduced by the action of the air flow returning after entering the opening, and is particularly remarkable for abrasive grains having a small average particle diameter. The upper limit of the average particle diameter of the abrasive grains is 20 μm or less, preferably 15 μm or less, and more preferably 10 μm or less. By setting the upper limit value of the average particle diameter of the abrasive grains within this range, the workability of the small-diameter through hole can be improved. The average particle diameter of the abrasive grains can be measured by, for example, scanning electron microscope observation, and in detail, can be performed by the method described in japanese patent application laid-open No. 2008-41932.

The pressure (machining pressure) of the blasting abrasive grains is preferably 0.05MPa or more, more preferably 0.1MPa or more, and still more preferably 0.15MPa or more, and preferably 1MPa or less, more preferably 0.8MPa or less, and still more preferably 0.5MPa or less. By setting the processing pressure within this range, the processing time can be shortened. The processing pressure here is a value of the surface of the insulating layer.

The distance between the nozzle and the mask is preferably 200mm or less, more preferably 190mm or less, further preferably 180mm or less, preferably 10mm or more, more preferably 15mm or more, further preferably 20mm or more. By setting the distance within this range, the through-hole can be formed efficiently.

The manufacturing method of the present invention exhibits a characteristic that even a through hole having a small diameter at the top of the through hole can be processed in a short time by sandblasting. The processing time is preferably less than 10 minutes, more preferably 8 minutes or less, further preferably 5 minutes or less, and less than 5 minutes. The lower limit is not particularly limited, and may be 0.1 minute or more.

Fig. 3 shows an example in which the support 21 is used as a mask, but instead of the support 21, either a metal foil or a dry film may be used as a mask.

< other working procedures >

In the production of the printed wiring board, after the end of the step (B), the steps (C) of roughening the insulating layer and (D) of forming the conductor layer may be further performed. These step (C) and step (D) may be carried out by various methods known to those skilled in the art used for manufacturing printed wiring boards. Further, if necessary, the insulating layer and the conductor layer may be repeatedly formed by performing the steps (a) to (D) to form a multilayer wiring board. Further, the method for manufacturing a printed wiring board may further include a step of removing the mask at an appropriate timing. The mask is usually removed after step (B) and before step (C).

The step (C) is a step of performing roughening treatment (also referred to as desmearing treatment) on the insulating layer. In general, in this step (C), the abrasive grains are also removed. The step and conditions of the roughening treatment are not particularly limited, and known steps and conditions generally used for forming an insulating layer of a printed wiring board can be employed. For example, the insulating layer may be subjected to a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralizing treatment with a neutralizing liquid in this order. The swelling solution used in the roughening treatment is not particularly limited, and examples thereof include an alkali solution and a surfactant solution, and the alkali solution is preferably an alkali solution, and a sodium hydroxide solution and a potassium hydroxide solution are more preferably used as the alkali solution. Examples of commercially available Swelling liquids include "spinning Dip securigant P (スウェリング, ディップ, セキュリガンス P)", "spinning Dip securigant SBU", "spinning Dip securigant P (スウェリングディップ, セキュリガント P)" manufactured by amett japan. The swelling treatment with the swelling solution is not particularly limited, and for example, the swelling treatment can be performed by immersing the insulating layer in the swelling solution at 30 to 90 ℃ for 1 to 20 minutes. From the viewpoint of suppressing swelling of the resin of the insulating layer to an appropriate level, the insulating layer is preferably immersed in a swelling solution at 40 to 80 ℃ for 5 to 15 minutes. The oxidizing agent used in the roughening treatment is not particularly limited, and examples thereof include an alkaline permanganic acid solution obtained by dissolving potassium permanganate or sodium permanganate in an aqueous solution of sodium hydroxide. The roughening treatment with an oxidizing agent such as an alkaline permanganic acid solution is preferably performed by immersing the insulating layer in an oxidizing agent solution heated to 60 to 100 ℃ for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5 to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganic acid solutions such as "Concentrate Compact CP" and "Dosing Solution securigant P" manufactured by amett japan. The neutralizing Solution used for the roughening treatment is preferably an acidic aqueous Solution, and examples of commercially available products include "Reduction Solution securigant P" manufactured by amatt japan. The treatment with the neutralizing solution can be performed by immersing the treated surface subjected to the roughening treatment with the oxidizing agent in the neutralizing solution at 30 to 80 ℃ for 1 to 30 minutes. From the viewpoint of workability, the object to be roughened by the oxidizing agent is preferably immersed in a neutralizing solution at 40 to 70 ℃ for 5 to 20 minutes.

In one embodiment, the arithmetic average roughness (Ra) of the surface of the insulating layer after the roughening treatment is preferably 500nm or less, more preferably 400nm or less, and still more preferably 300nm or less. The lower limit is not particularly limited, but is preferably 30nm or more, more preferably 40nm or more, and further preferably 50nm or more. The arithmetic average roughness (Ra) of the surface of the insulating layer can be measured using a non-contact surface roughness meter.

Step (D) is a step of forming a conductor layer, and the conductor layer is formed on the insulating layer. The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains 1 or more metals selected from gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin, and indium. The conductor layer may be a single metal layer or an alloy layer, and examples of the alloy layer include layers formed of an alloy of 2 or more metals selected from the above metals (for example, a nickel-chromium alloy, a copper-nickel alloy, and a copper-titanium alloy). Among them, from the viewpoint of versatility of conductor layer formation, cost, ease of patterning, and the like, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy, a copper-nickel alloy, or a copper-titanium alloy is preferable, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver, or copper, or an alloy layer of a nickel-chromium alloy is more preferable, and a single metal layer of copper is even more preferable.

The conductor layer may have a single-layer structure or a multilayer structure in which two or more single metal layers or alloy layers made of different metals or alloys are stacked. When the conductor layer has a multilayer structure, the layer in contact with the insulating layer is preferably a single metal layer of chromium, zinc, or titanium, or an alloy layer of a nickel-chromium alloy.

The thickness of the conductor layer depends on the design of the desired printed wiring board, and is usually 3 to 35 μm, preferably 5 to 30 μm.

In one embodiment, the conductor layer may be formed by plating. For example, a conductor layer having a desired wiring pattern can be formed by plating the surface of the insulating layer by a conventionally known technique such as a semi-additive method or a full-additive method, and is preferably formed by the semi-additive method from the viewpoint of ease of manufacturing. Hereinafter, an example of forming a conductor layer by a semi-additive method is shown.

First, a plating seed layer is formed on the surface of the insulating layer by electroless plating. Next, a mask pattern is formed on the formed plating seed layer to expose a part of the plating seed layer corresponding to a desired wiring pattern. After a metal layer is formed on the exposed plating seed layer by electrolytic plating, the mask pattern is removed. Then, the unnecessary plating seed layer is removed by etching or the like, whereby a conductor layer having a desired wiring pattern can be formed.

The method for manufacturing a printed wiring board of the present invention performs the steps (a) and (B), and thus exhibits a characteristic of being capable of forming a small-diameter through hole. The diameter of the top of the through hole (through hole diameter) is preferably 100 μm or less, more preferably 75 μm or less, further preferably 55 μm or less, preferably 5 μm or more, more preferably 10 μm or more, further preferably 15 μm or more. The method of measuring the diameter of the through hole and the details of the evaluation can be performed by the methods described in the examples described later.

The method for manufacturing a printed wiring board of the present invention performs the step (a) and the step (B), and thus exhibits excellent stain removability. Therefore, when desmear treatment in which the through-hole is formed by the method of the present invention and then immersed in the order of the swelling liquid, the roughening liquid and the neutralizing liquid is performed, no resin residue is observed at the bottom of the through-hole. The stain removability can be evaluated by the method described in the examples described later.

The method for manufacturing a printed wiring board of the present invention exhibits a characteristic of suppressing a halo phenomenon. Specifically, even if the through hole diameter is a small diameter within the above range, the halo phenomenon can be suppressed. The halo phenomenon will be described below with reference to the drawings.

Fig. 4 is a plan view schematically showing a surface 22U of the insulating layer 22 on the side opposite to the metal layer 12 (not shown in fig. 4) in the conventional printed wiring board in which the through hole is formed by the laser beam immediately before the conductor layer is formed. Fig. 5 is a cross-sectional view schematically showing an insulating layer 22 of a conventional printed wiring board in which a via hole is formed by a laser beam immediately before a conductor layer is formed, together with a metal layer 12 of an inner circuit board. Fig. 5 shows a cross section obtained by cutting the insulating layer 22 in a plane parallel to the thickness direction of the insulating layer 22 through the center 220C of the via bottom 220 of the via 40.

As shown in fig. 5, when the through-hole 40 is formed by laser, a discolored portion 240 may be generated due to degradation of the resin by heat of the laser. The discolored part 240 is corroded by the chemical during the roughening treatment, and the insulating layer 22 is peeled off from the metal layer 12, and a continuous gap 260 may be formed from the edge 250 of the through-hole bottom 220 (halo phenomenon).

In the present invention, since the blast treatment is used which hardly generates heat after the opening portion is formed by the laser, the deterioration of the resin can be suppressed. Therefore, the insulating layer 22 can be prevented from peeling off from the metal layer 12, and the size of the gap portion 260 can be reduced.

The edge 250 of the through-hole bottom (bottom of the through-hole (via bottom)) 220 corresponds to the edge on the inner peripheral side of the gap 260. Therefore, the distance Wb from the edge 250 of the through-hole bottom portion 220 to the end 270 on the outer peripheral side of the gap portion 260 (i.e., the end on the side away from the center 220C of the through-hole bottom portion 220) corresponds to the dimension in the in-plane direction of the gap portion 260. Here, the in-plane direction refers to a direction perpendicular to the thickness direction of the insulating layer 22. In the following description, the distance Wb may be referred to as a halo distance Wb from the edge 250 of the through-hole bottom 220 of the through-hole 40. The degree of suppression of the halo phenomenon can be evaluated by the halo distance Wb from the edge 250 of the via bottom 220. Specifically, the smaller the halo distance Wb from the edge 250 of the via bottom 220, the more evaluable it is that the halo phenomenon can be effectively suppressed.

When the manufacturing method of the present invention is used, even if a via hole having a top diameter of 50 μm or less is formed, the halo distance Wb from the edge 250 of the via hole bottom 220 of the via hole 40 of the insulating layer 22 can be preferably 5 μm or less, more preferably 4 μm or less, and still more preferably 3 μm or less. The lower limit is not particularly limited, and may be 0 μm or more, 0.1 μm or more, or the like.

In the manufacturing method of the present invention, as shown in fig. 6 to 10, a printed wiring board having a through hole and a groove can be manufactured. In detail, as an example shown in fig. 6, before the step (a), the insulating layer 22 is formed on the inner layer circuit board 10, and the metal foil 60 is further laminated on the insulating layer 22. After the metal foil 60 is laminated, as shown in fig. 7, a pattern etching process is performed on the metal foil 60 to remove a part of the metal foil 60 and form a hole 61. Next, as shown in fig. 8, a step (a) of irradiating a predetermined portion of the metal foil 60 with a laser beam is performed to form the opening 30. Next, as an example shown in fig. 9, step (B) is performed to form a through hole 40 from the opening 30 and to form a groove 50 by making abrasive grains collide with the bottom of the hole 61 by sandblasting. Then, as shown in fig. 10 as an example, the via hole 40 and the trench 50 are filled by electrolytic plating to form a filled via hole 80. After forming the filled via 80, the metal foil 60 may be removed as needed. Further, a metal foil with a resin composition layer may be obtained by laminating a metal foil on the resin composition layer of the resin sheet with a support, and the metal foil with a resin composition layer may be laminated on the inner layer circuit board to form an insulating layer and a metal foil on the inner layer circuit board.

In the manufacturing method of the present invention, as shown in fig. 11 to 16, a printed wiring board having a patterned conductor layer can be manufactured. In detail, as an example shown in fig. 11, before the step (a), the insulating layer 22 is formed on the inner layer circuit board 10, and the metal foil 60 and the dry film 70 are further laminated on the insulating layer 22. After laminating the metal foil 60 and the dry film 70, as shown in an example of fig. 12, a part of the dry film 70 is exposed and developed to form a hole 71 from which a part of the dry film 70 is removed. Next, as an example shown in fig. 13, a step (a) of irradiating a predetermined portion of the dry film 70 with a laser beam is performed to form the opening 30. Next, as an example shown in fig. 14, through-hole 40 is formed from opening 30 by performing step (B). After the step (B) is completed, the through-hole 40 and the hole 71 are filled by electrolytic plating to form a filled through-hole 80 as in the example shown in fig. 15, and the dry film (not shown) is removed as in the example shown in fig. 16 to form a patterned conductor layer. As the plating seed layer of the electrolytic plating, the metal foil 60 can be used. Before removing the dry film, the surface of the filled via hole 80 may be polished by buffing or the like as necessary to adjust the height of the filled via hole 80. Further, a metal foil with a resin composition layer may be obtained by laminating a metal foil on the resin composition layer of the resin sheet with a support, and the metal foil with a resin composition layer may be laminated on the inner layer circuit board to form an insulating layer and a metal foil on the inner layer circuit board.

In the manufacturing method of the present invention, as shown in fig. 17 to 21, a printed wiring board having a through hole and a groove can be manufactured. In detail, as an example shown in fig. 17, before the step (a), the insulating layer 22 is formed on the inner layer circuit board 10, and the dry film 70 is further laminated on the insulating layer 22. After laminating the dry film 70, as shown in fig. 18, a part of the dry film 70 is exposed and developed to form a hole 71 from which a part of the dry film 70 is removed. Next, as an example shown in fig. 19, a step (a) of irradiating a predetermined portion of the dry film 70 with a laser beam is performed to form the opening 30. Next, as an example shown in fig. 20, the through hole 40 is formed from the opening 30 by performing the step (B), and the groove 50 is formed by colliding abrasive grains with the bottom of the hole 71 by the blast treatment. Then, as shown in fig. 21 as an example, the filled via hole 80 is formed by filling the via hole 40 and the trench 50 by electrolytic plating. After forming the filled via 80, the dry film 70 may be removed as needed. Before removing the dry film, the surface of the filled via hole 80 may be polished by buffing or the like as necessary to adjust the height of the filled via hole 80.

[ semiconductor device ]

The semiconductor device of the present invention includes a printed wiring board. The semiconductor device of the present invention can be manufactured using the printed wiring board obtained by the manufacturing method of the present invention.

Examples of the semiconductor device include various semiconductor devices used in electric products (for example, computers, mobile phones, digital cameras, televisions, and the like) and vehicles (for example, motorcycles, automobiles, electric trains, ships, airplanes, and the like).

The semiconductor device of the present invention can be manufactured by mounting a component (semiconductor chip) on a conductive portion of a printed wiring board. The "conductive portion" refers to a portion for transmitting an electrical signal in the printed wiring board, and the position thereof may be a surface or a buried portion. The semiconductor chip is not particularly limited as long as it is a circuit element made of a semiconductor.

The method of mounting a semiconductor chip in the manufacture of a semiconductor device is not particularly limited as long as the semiconductor chip functions effectively, and specific examples thereof include a wire bonding mounting method, a flip chip mounting method, a mounting method using a non-bumpy build-up layer (BBUL), a mounting method using an Anisotropic Conductive Film (ACF), a mounting method using a non-conductive film (NCF), and the like. Here, the "mounting method using a non-uneven buildup layer (BBUL)" means "a mounting method in which a semiconductor chip is directly embedded in a recess of a printed wiring board and the semiconductor chip is connected to a wiring on the printed wiring board".

Examples

Hereinafter, examples are shown to specifically explain the present invention. The present invention is not limited to the following examples. In the following description, "part" and "%" representing amounts means "part by mass" and "% by mass", respectively, unless otherwise specified. The operations described below are performed under an environment of normal temperature and normal pressure unless otherwise specified.

< Synthesis example 1: synthesis of elastomer

In a reaction vessel, 69G of bifunctional hydroxyl-terminated polybutadiene ("G-3000" manufactured by japan soga, number average molecular weight 3000, hydroxyl equivalent 1800G/eq.), 40G of an aromatic hydrocarbon-based mixed solvent ("Ipzole 150" manufactured by shin-oil petrochemical company), and 0.005G of dibutyltin dilaurate were charged, mixed and dissolved uniformly. After the temperature was raised to 60 ℃ after homogenization, 8g of isophorone diisocyanate (IPDI, 113g/eq isocyanate group equivalent, manufactured by EVONIK DEGUSSA Japan) was added with stirring, and the reaction was carried out for about 3 hours.

Then, 23g of cresol novolak resin ("KA-1160" manufactured by DIC corporation and having a hydroxyl equivalent of 117 g/eq) and diethylene glycol were added to the reaction mixture60g of ethyl diglycol acetate (manufactured by Dacellosolve corporation) was reacted at 150 ℃ for about 10 hours while stirring. 2250cm by FT-IR^-1The disappearance of NCO peak (2) was confirmed. The disappearance of the NCO peak was confirmed as the end point of the reaction, and the reaction was cooled to room temperature. Then, the reaction mixture was filtered through a 100-mesh filter cloth to obtain an elastomer having a butadiene structure and a phenolic hydroxyl group (phenolic hydroxyl group-containing butadiene resin: 50% by mass of nonvolatile matter). The number average molecular weight of the elastomer was 5900 and the glass transition temperature was-7 ℃.

< production of resin sheet with support 1 >

A biphenyl type epoxy resin (NC-3000-L manufactured by Nippon Chemicals, Inc., about 269g/eq in terms of epoxy equivalent) 10 parts, a liquid 1, 4-glycidylcyclohexane (ZX 1658 manufactured by Nippon chemical Co., Ltd., about 135g/eq in terms of epoxy equivalent) 10 parts, a bicresol type epoxy resin (YX 4000H manufactured by Mitsubishi chemical Co., Ltd., about 185g/eq in terms of epoxy equivalent) 10 parts, an active ester compound (HPC-8000-65T manufactured by DIC, about 223g/eq in terms of active group equivalent, 65 mass% of nonvolatile toluene solution) 50 parts, a triazine skeleton-containing phenol-based curing agent (LA-3018-50P manufactured by DIC, about 151g/eq in terms of hydroxyl group equivalent, 50 mass% of solid content 2-methoxypropanol solution) 6 parts, a phenoxy resin (YX 7553BH30 manufactured by Mitsubishi chemical Co., Ltd., a phenoxy resin, a phenol-based curing agent (ZX 7553BH 30), Solid content 30 mass% of 1: 1 solution) 10 parts, 10 parts of a carbodiimide compound ("V-03" manufactured by Nisshinbo chemical Co., Ltd., active group equivalent of about 216g/eq., and a toluene solution having a solid content of 50% by mass), 220 parts of a spherical silica (average particle diameter 0.5 μm, "SO-C2" manufactured by Yadmax Co., Ltd.) surface-treated with an aminosilane-based coupling agent ("KBM 573" manufactured by shin-Etsu chemical Co., Ltd.), 1 part of a phosphorus-based flame retardant ("HCA-HQ-HS" manufactured by Sanko Co., Ltd., 10- (2, 5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide), 1 part of rubber particles (StaPHYLOID AC3816N manufactured by AICA Co., Ltd.), 5 parts of a curing accelerator (4-Dimethylaminopyridine (DMAP), a MEK solution having a solid content of 5% by mass), and a method for producing a flame retardant, Methyl ethyl ketone (25 parts) and cyclohexanone (15 parts) were mixed and uniformly dispersed in a high-speed rotary mixer to prepare a resin varnish (1).

Subsequently, a resin varnish 1 was uniformly applied to a release surface of a polyethylene terephthalate film (AL 5, 38 μm thick, manufactured by Lindelco) with release treatment as a support so that the thickness of the resin composition layer became 40 μm, and the resin composition layer was dried at 80 to 120 ℃ (average 100 ℃) for 6 minutes to prepare a resin sheet 1 with a support. Further, by changing the coating thickness of the resin varnish 1, the resin sheet 1 with a support having the thickness of the resin composition layer after drying of 20 μm and 15 μm was also produced.

< production of resin sheet 2 with support >

30 parts of a biphenyl type epoxy resin ("NC-3000-L" manufactured by Nippon chemical company, "having an epoxy equivalent of about 269g/eq.), 30 parts of a bisphenol A type epoxy resin (" 828EL "manufactured by Mitsubishi chemical company, having an epoxy equivalent of about 180g/eq.), 20 parts of a tetraphenylethane type epoxy resin (" JeR1031S "manufactured by Mitsubishi chemical company, having an epoxy equivalent of about 198g/eq.), 5 parts of a phenol novolac-based curing agent having a triazine skeleton (" LA-7054 "manufactured by Mitsubishi chemical company, having a hydroxyl equivalent of about 125 g/eq.), 10 parts of a MEK solution having a solid content of 60%, 6 parts of a phenol novolac-based curing agent (" TD2090 "manufactured by Mitsubishi chemical company, having a hydroxyl equivalent of about 105g/eq.), a phenoxy resin (" YX7553BH30 "manufactured by Mitsubishi chemical company, having a solid content of 30 mass%, 8 parts of a solution of a MEK and a 1: 1 solution of a solid content of 60%, and 8 parts of a spherical silica (5730.5. mu.m) treated with an aminosilicone kind of a coupling agent (" KBM chemical industry Co., manufactured by Kyun 140 parts of SO-C2, product of Yadmax corporation, 5 parts of a phosphorus flame retardant (HCA-HQ-HS, product of Sanko., 10- (2, 5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide), 3 parts of a curing accelerator (4-Dimethylaminopyridine (DMAP), 5 mass% MEK solution as a solid content), 25 parts of methyl ethyl ketone, and 15 parts of cyclohexanone were mixed and uniformly dispersed in a high-speed rotary mixer to prepare a resin varnish 2.

In the production of the resin sheet 1 with a support, the resin varnish 1 was changed to the resin varnish 2. Except for the above, the resin sheet 2 with a support is produced in the same manner as the production of the resin sheet 1 with a support.

< production of resin sheet 3 with support >

20 parts of bisphenol A epoxy resin ("828 EL" manufactured by Mitsubishi chemical corporation and having an epoxy equivalent of about 180g/eq.), 10 parts of naphthol epoxy resin ("ESN-475V" manufactured by Nippon iron chemical corporation and having an epoxy equivalent of about 332g/eq.), 10 parts of bicresol epoxy resin ("YX 4000H" manufactured by Mitsubishi chemical corporation and having an epoxy equivalent of about 185g/eq.), 20 parts of naphthyl ether epoxy resin ("HP 6000" manufactured by DIC corporation and having an epoxy equivalent of about 260g/eq.), 10 parts of cyanate ester curing agent ("BA 230S 75" manufactured by Lonza Japan and having a cyanate equivalent of about 235g/eq., and an MEK solution having a non-volatile content of 75 mass%), 10 parts of cyanate ester curing agent ("BADCy" manufactured by Lonza Japan and having a cyanate equivalent of about 142g/eq.), 10 parts of active ester compound ("HPC-8000-65T" manufactured by DIC corporation and having an active base equivalent of about 223g/eq ·, Toluene solution having a nonvolatile content of 65 mass%), phenoxy resin (product of mitsubishi chemical corporation, "YX 7553BH 30", solid content of 30 mass% of 1: 1 solution) 8 parts, spherical silica (average particle size 0.5 μm, "SO-C2", product of yohima corporation) surface-treated with an aminosilane-based coupling agent ("KBM 573", product of shin-yue chemical industry) 170 parts, a curing accelerator (4-Dimethylaminopyridine (DMAP), MEK solution having a solid content of 5 mass%) 3 parts, 1 mass% MEK solution of cobalt (III) acetylacetonate (product of tokyo chemical corporation) 5 parts, methyl ethyl ketone 40 parts, and cyclohexanone 20 parts, and uniformly dispersed in a high-speed rotary mixer to prepare a resin varnish 3.

In the production of the resin sheet 1 with a support, the resin varnish 1 was changed to the resin varnish 3. Except for the above, the resin sheet 3 with a support is produced in the same manner as the production of the resin sheet 1 with a support.

< production of resin sheet 4 with support >

5 parts of phenol-phthalimidine type epoxy resin ("WHR-991S" manufactured by Nippon chemical Co., Ltd., epoxy equivalent of about 265g/eq.), 20 parts of biphenyl type epoxy resin ("NC-3000-L" manufactured by Nippon chemical Co., Ltd., epoxy equivalent of about 269g/eq.), 50 parts of the elastomer obtained in Synthesis example 1, and spherical silica (average particle diameter: 0.08 μm, specific surface area: 30.7 m) surface-treated with a methacrylic silane coupling agent ("KBM 503" manufactured by shin chemical industry Co., Ltd.) (average particle diameter: 0.08 μm, specific surface area: 30.7 m)²15 parts of UFP-30 manufactured by Denka corporation and phosphorus flame retardant (Sanguang corporation)"HCA-HQ-HS", 10- (2, 5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide) (5 parts), 2 parts of a curing accelerator (a methyl ethyl ketone solution containing 10 mass% of the solid content of 1-benzyl-2-phenylimidazole (1B 2PZ, manufactured by Siguo chemical industries Co., Ltd.), and 20 parts of methyl ethyl ketone were mixed and uniformly dispersed in a high-speed rotary mixer to prepare a resin varnish 4.

In the production of the resin sheet 1 with a support, the resin varnish 1 was changed to the resin varnish 4. Except for the above, the resin sheet 4 with a support is produced in the same manner as the production of the resin sheet 1 with a support.

< production of resin sheet with support 5 >

In the production of the resin sheet 1 with a support body,

1) 220 parts of spherical silica (average particle diameter: 0.5 μm, manufactured by Yatoma corporation, "SO-C2") surface-treated with an aminosilane-based coupling agent (manufactured by shin-Etsu chemical Co., Ltd. "KBM 573") was changed to 270 parts of spherical alumina (average particle diameter: 5.3 μm, manufactured by Denka corporation, "DAW-0525") surface-treated with an aminosilane-based coupling agent (manufactured by shin-Etsu chemical Co., Ltd. "),

2) 50 parts of spherical alumina (average particle size 0.3 μm, manufactured by Denka as "ASFP-20") surface-treated with an aminosilane-based coupling agent ("KBM 573", manufactured by shin-Etsu chemical industries, Ltd.);

except for the above, the resin sheet 5 with a support is produced in the same manner as the production of the resin sheet 1 with a support.

The components used for the preparation of the resin varnishes 1 to 5 and their amounts (parts by mass of nonvolatile components) are shown in the following table. The content of the component (a) is defined as a content where the nonvolatile content in the resin composition is 100 mass%.

[ Table 1]

(Table 1)

< evaluation of elastic modulus >

(1) Preparation of cured product for evaluation

A glass cloth base epoxy resin double-sided copper-clad laminate (R5715 ES, 0.7mm in thickness, 255mm in square) was laminated on the release agent-untreated surface of a release agent-treated PET film (501010, 38 μm in thickness, 240mm square, manufactured by Lingduke) and the four sides thereof were fixed with a polyimide adhesive tape (10 mm in width) (hereinafter, sometimes referred to as "fixed PET film").

The resin sheets 1 to 5 with a support having a resin thickness of 40 μm were laminated on the release-treated surface of the "fixed PET film" by using a batch vacuum press laminator (MVLP-500, manufactured by Nako Co., Ltd.). The lamination was performed by reducing the pressure to 13hPa or less for 30 seconds and then pressing at 100 ℃ and a pressure of 0.74MPa for 30 seconds.

Subsequently, the support was peeled off, and after being put into an oven at 190 ℃, the resin sheet with the support was thermally cured under curing conditions of 90 minutes.

After the thermosetting, the polyimide adhesive tape was peeled off, and the cured product was taken off from both surfaces of the glass cloth substrate epoxy resin copper-clad laminate, and further a PET film (manufactured by ledebacaceae, product "501010") was peeled off to obtain a sheet-like cured product. The resulting cured product was referred to as "cured product for evaluation".

(2) Evaluation of modulus of elasticity

The resulting cured product for evaluation was subjected to a tensile test of the cured product by a Tensilon Universal testing machine (manufactured by A & D) in accordance with Japanese Industrial Standard (JIS K7127), and the elastic modulus at 23 ℃ was measured.

< example 1 >

(1) Lamination of resin sheets with support

A resin sheet 1 with a support having a resin thickness of 40 μm was laminated on both surfaces of a laminate having a copper surface roughened with a microetching agent (CZ 8201, manufactured by MEC) by using a batch vacuum press laminator (MVLP-500, manufactured by Nako Co., Ltd.) so that the resin composition layers were in contact with each other. The lamination was performed by reducing the pressure to 13hPa or less for 30 seconds and then pressing at 100 ℃ and a pressure of 0.74MPa for 30 seconds.

(2) Curing of resin composition layer

The resin composition layer was cured under curing conditions of 180 ℃ and 30 minutes to form an insulating layer.

(3) Formation of vias

(3-1) formation of openings by laser

Using CO₂The opening was formed by a laser beam machine ("LC-2E 21B/1C" manufactured by Hitachi-Viya-machine Co., Ltd.). The diameter of the top of the opening on the surface of the insulating layer was 50 μm, and the depth of the opening was 30 μm. The depth of the opening is determined by calculating the difference between the deepest portion of the non-processed portion and the deepest portion of the processed portion of the insulating layer in the cross-sectional view.

(3-2) sandblasting treatment

Next, alumina abrasive grain slurry of #2000 (average particle diameter 6.7 μm) was used as abrasive grains, and CO was used₂The support of the laser opening was used as a mask, and the opening was subjected to sandblasting to form a through-hole (having a top diameter of 50 μm). The support was peeled off after the sandblasting process, and the substrate 1 for evaluation was obtained.

< example 2 >

In example 1, the resin sheet 1 with a support was changed to the resin sheet 2 with a support. Except for the above, the evaluation substrate 2 was obtained in the same manner as in example 1.

< example 3 >

In example 1, the resin sheet 1 with a support was changed to the resin sheet 3 with a support. Except for the above, the evaluation substrate 3 was obtained in the same manner as in example 1.

< example 4 >

In example 1, the resin sheet 1 with a support was changed to the resin sheet 4 with a support. Except for the above, the evaluation substrate 4 was obtained in the same manner as in example 1.

< example 5 >

In example 1, the resin sheet 1 with a support was changed to the resin sheet 5 with a support. Except for the above, the evaluation substrate 5 was obtained in the same manner as in example 1.

< example 6 >

(1) Production of copper foil with resin composition layer

The copper foil with a carrier (manufactured by Mitsui Metal mining Co., Ltd., Microthin (マイクロシン) MTEx, thickness of copper foil 3 μm) was uniformly coated with the resin varnish 1 so that the thickness of the resin composition layer became 40 μm, and dried at 80 to 120 ℃ (average 100 ℃) for 6 minutes to prepare a copper foil with a resin composition layer.

(2) Lamination of copper foil with resin composition layer

The obtained copper foil with the resin composition layer was laminated on both surfaces of a laminate having a roughened copper surface with a microetching agent (CZ 8201, manufactured by MEC) using a vacuum press laminator (MVLP-500, manufactured by nomex corporation) so that the resin composition layer was in contact with the laminate. The lamination was performed by reducing the pressure to 13hPa or less for 30 seconds and then pressing at 100 ℃ and a pressure of 0.74MPa for 30 seconds.

(3) Curing of resin composition layer

The resin composition layer laminated with the copper foil with the carrier is cured at 180 ℃ for 30 minutes under curing conditions to form an insulating layer.

(4) Formation of vias

(4-1) formation of openings by laser

After stripping off the carrier, CO is used₂The opening was formed by a laser beam machine ("LC-2E 21B/1C" manufactured by Hitachi-Viya-Mechanics). The diameter of the top of the opening on the surface of the insulating layer was 50 μm, and the depth of the opening was 30 μm.

(4-2) blasting treatment

Next, alumina abrasive grain slurry of #2000 (average particle diameter 6.7 μm) was used as abrasive grains, and CO was used₂The laser-opened copper foil was used as a mask, and the opening was subjected to sand blasting to form a through hole (top diameter: 50 μm). After the sandblasting, the copper foil was peeled off to obtain an evaluation substrate 6.

< example 7 >

(1) Lamination of resin sheets with support

A resin sheet 1 with a support having a resin thickness of 40 μm was laminated on a copper foil with a carrier (a copper foil having a thickness of 3 μm, Microthin MTEx, manufactured by Mitsui Metal mining Co., Ltd.) so that the resin composition layers were in contact with each other using a batch vacuum press laminator (MVLP-500, manufactured by Minkoku Co., Ltd.). The lamination is carried out by reducing the pressure for 30 seconds to 13hPa or less, and then pressing at 100 ℃ and a pressure of 0.74MPa for 30 seconds to obtain a copper foil with a resin composition layer.

(2) Lamination of copper foil with resin composition layer

(3) Curing of resin composition layer

The resin composition layer was cured at 180 ℃ for 30 minutes to form an insulating layer.

(4) Formation of opening in copper foil

The copper foil with the carrier is partially etched with the microetching agent to form an opening for forming a trench.

(5) Formation of vias

(5-1) formation of openings by laser

Using CO₂The opening was formed by a laser beam machine ("LC-2E 21B/1C" manufactured by Hitachi-Viya-machine Co., Ltd.). The diameter of the top of the opening on the surface of the insulating layer was 50 μm, and the depth of the opening was 30 μm.

(5-2) blasting treatment

Next, alumina abrasive grain slurry of #2000 (average particle diameter 6.7 μm) was used as abrasive grains, and CO was used₂The laser-opened copper foil was used as a mask, and the opening was subjected to sand blasting to form a through hole (top diameter: 50 μm). Further, the insulating layer is also dug into the portion where the hole for forming the groove is formed by the blast processing, thereby forming the groove. After the sandblasting, the copper foil was peeled off to obtain an evaluation substrate 7.

< example 8 >

In example 7, (3) the curing of the resin composition layer was followed by the following operations, and (4) the formation of the opening portion of the copper foil was not performed. Except for the above, the evaluation substrate 8 was obtained in the same manner as in example 7.

(4) Lamination of dry films

A dry film (NCM 325, thickness 25 μm, manufactured by Nikko-Materials Co.) was bonded to the surface of the copper foil. The dry film was laminated by using a batch vacuum laminator ("MVLP-500" manufactured by Nako Co., Ltd.) under a reduced pressure of 13hPa or less for 30 seconds and then under a pressure of 0.1MPa at a temperature of 70 ℃ for 20 seconds. Then, a glass mask having a groove pattern was placed on the polyethylene terephthalate film as a protective layer of the dry film, and irradiated by a UV lamp at an intensity of 20mJ/cm²UV irradiation was performed. After UV irradiation, a spray treatment was carried out for 50 seconds using a 1% aqueous solution of sodium carbonate at 25 ℃ and a spray pressure of 0.15 MPa. Then, the opening for forming the groove pattern is formed by water washing.

< example 9 >

(1) Production of copper foil with resin composition layer

Uniformly applying a resin varnish 1 to a copper foil (JDLC, 12 μm thick, manufactured by JX Metal Co., Ltd.) so that the thickness of the resin composition layer becomes 40 μm, and drying the resin varnish at 80 to 120 ℃ (average 100 ℃) for 6 minutes to prepare a copper foil with a resin composition layer;

(2) lamination of copper foil with resin composition layer

The obtained copper foil with a resin composition layer was laminated on both surfaces of a laminate having a roughened copper surface with a microetching agent ("CZ 8201" manufactured by MEC corporation) by using a vacuum pressure laminating machine (MVLP-500 manufactured by famous machine) so that the resin composition layer was in contact with the laminate. The lamination was performed by reducing the pressure to 13hPa or less for 30 seconds and then pressing at 100 ℃ and a pressure of 0.74MPa for 30 seconds.

(3) Curing of resin composition layer

The laminate having the copper foil with the resin composition layer laminated thereon was cured at 180 ℃ for 30 minutes under curing conditions to form an insulating layer, thereby obtaining a laminate having a copper foil and a cured layer.

(4) Half etching of copper foil

By immersing the laminated plate with the copper foil and the cured layer in an iron chloride solution, half etching was performed to make the thickness of copper from 12 μm to 5 μm, and the adhered iron chloride solution was rinsed with pure water.

(5) Pretreatment of laser processing

Then, a pretreatment for laser processing was performed using a pretreatment liquid for laser processing (product of MacDermid Performance Solutions Japan, "MULTIBLOND 100").

(6) Formation of vias

(6-1) formation of openings by laser

(6-2) blasting treatment

Next, alumina abrasive grain slurry of #2000 (average particle diameter 6.7 μm) was used as abrasive grains, and CO was used₂The laser-opened copper foil was used as a mask, and the opening was subjected to sand blasting to form a through hole (top diameter: 50 μm). After the sandblasting, the copper foil was peeled off to obtain an evaluation substrate 9.

< example 10 >

In example 9, (4) half etching of the copper foil was not performed. Except for the above, the evaluation substrate 10 was obtained in the same manner as in example 9.

< example 11 >

In example 1, the resin sheet 1 with a support having a resin thickness of 40 μm was changed to the resin sheet 1 with a support having a resin thickness of 20 μm,

the formation of the through-hole is performed as follows. Except for the above, the evaluation substrate 11 was obtained in the same manner as in example 1.

(1) Formation of vias

(1-1) formation of openings by laser

Using CO₂Laser beam machine (manufactured by Hiliviya machine Co., Ltd.)"LC-2E 21B/1C") to form an opening. The diameter of the top of the opening on the surface of the insulating layer was 30 μm, and the depth of the opening was 15 μm.

(1-2) blasting treatment

Next, a #3000 alumina abrasive grain slurry (average particle size 4.0 μm) was used as abrasive grains, and CO was used₂The support with the laser opening was used as a mask, and the opening was subjected to sand blasting to form a through hole (having a top diameter of 30 μm). The support was peeled off after the sandblasting process, and the evaluation substrate 11 was obtained.

< example 12 >

In example 7, the resin sheet 1 with a support having a resin thickness of 40 μm was changed to the resin sheet 1 with a support having a resin thickness of 15 μm,

the formation of the through-hole is performed as follows. Except for the above, the evaluation substrate 12 was obtained in the same manner as in example 7.

(1) Formation of vias

(1-1) formation of openings by laser

The opening was formed by using a UV-YAG laser beam machine ("LU-2L 212/M50L" manufactured by Vicat machine Co., Ltd.). The diameter of the top of the opening on the surface of the insulating layer was 20 μm, and the depth of the opening was 12 μm.

(1-2) blasting treatment

Next, using a #3000 alumina abrasive grain slurry (average particle diameter 4.0 μm) as abrasive grains, a copper foil opened by a UV-YAG laser was used as a mask to perform a blast processing of the opening portion, thereby forming a through hole (top diameter 20 μm). After the sandblasting, the copper foil was peeled off to obtain the evaluation substrate 12.

< example 13 >

In example 12, a copper foil with a carrier (manufactured by Mitsui Metal mining Co., Ltd., Microthin MTEx, thickness of copper foil 3 μm) was changed to a dry film (manufactured by Asahi Kasei corporation, trade name "ATP-10 VTDS", thickness 10 μm). Except for the above, the evaluation substrate 13 was obtained in the same manner as in example 12.

< example 14 >

In example 13, before forming the opening portion by the UV-YAG laser, an opening portion for a groove pattern was formed on the dry film using a mask. Except for the above, the evaluation substrate 14 was obtained in the same manner as in example 13.

< example 15 >

In example 2, the resin sheet 2 with a support having a resin thickness of 40 μm was changed to the resin sheet 2 with a support having a resin thickness of 25 μm,

the formation of the through-hole is performed as follows. Except for the above, the evaluation substrate 15 was obtained in the same manner as in example 2.

(1) Formation of vias

(1-1) formation of openings by laser

Using CO₂The opening was formed by a laser beam machine ("LC-2E 21B/1C" manufactured by Hitachi-Viya-machine Co., Ltd.). The diameter of the top of the opening on the surface of the insulating layer was 30 μm, and the depth of the opening was 25 μm.

(1-2) Via hole processing by sandblasting

Next, a #3000 alumina abrasive grain slurry (average particle size 4.0 μm) was used as abrasive grains, and CO was used₂The support with the laser opening was used as a mask, and the opening was subjected to sand blasting to form a through hole (having a top diameter of 30 μm). After the sandblasting, the support was peeled off to obtain a substrate 15 for evaluation.

< comparative example 1 >

In example 1, formation of the through-hole was performed as follows. Except for the above, the evaluation substrate 16 was obtained in the same manner as in example 1.

(1) Formation of vias

After the insulating layer was formed, the PET film as a support was peeled off. A through-hole was formed in the insulating layer from which the support was peeled by using a UV-YAG laser beam machine ("LU-2L 212/M50L" manufactured by Vicat machine corporation), and a substrate 16 for evaluation was obtained. The diameter of the top of the via hole in the surface of the insulating layer was 50 μm.

< comparative example 2 >

In example 1, formation of the through-hole was performed as follows. Except for the above, the evaluation substrate 17 was obtained in the same manner as in example 1.

(1) Formation of vias

Using CO₂Laser processing machine (Rilivian)"LC-2E 21B/1C" manufactured by MACHINERY CORPORATION) to form a through-hole, thereby obtaining an evaluation substrate 17. The diameter of the top of the via hole in the surface of the insulating layer was 50 μm.

< comparative example 3 >

In example 1, formation of the through-hole was performed as follows. Except for the above, the evaluation substrate 18 was obtained in the same manner as in example 1.

(1) Formation of vias

(1-1) formation of openings by laser

Using CO₂The opening was formed by a laser beam machine ("LC-2E 21B/1C" manufactured by Hitachi-Viya-machine Co., Ltd.). The diameter of the top of the opening on the surface of the insulating layer was 50 μm, and the depth of the opening was 35 μm. This is referred to as the substrate.

(1-2) desmutting treatment

The substrate was immersed in a Swelling Dip securiganteh P containing diethylene glycol monobutyl ether as a Swelling liquid at 60 ℃ for 5 minutes, and then in a Concentrate Compact P (KMnO) as a roughening liquid₄: 60g/L, NaOH: 40g/L aqueous Solution) at 80 ℃ for 30 minutes, and finally, in Reduction Solution securiganteh P manufactured by Ammet Japan as a neutralizing Solution at 40 ℃ for 5 minutes, the bottom of the opening portion was cut off to form a through hole.

< comparative example 4 >

In example 1, formation of the through-hole was performed as follows. Except for the above, the evaluation substrate 19 was obtained in the same manner as in example 1.

(1) Formation of vias

(1-1) formation of Via hole Pattern Using resist film for sandblasting

The surface of the insulating layer was patterned with a resist film for sandblasting (NCM 250, thickness 50 μm, manufactured by Nikko-Materials Co., Ltd.) to form a through hole having a diameter of 50 μm.

(1-2) blasting treatment

Next, a substrate 19 for evaluation was obtained by performing blasting of the through-hole portion using a blasting resist film having a through-hole pattern formed thereon as a mask using alumina abrasive grain slurry #2000 (average particle diameter 6.7 μm) as abrasive grains.

< comparative example 5 >

In comparative example 4, (1) formation of a through hole was performed as follows. Except for the above, the evaluation substrate 20 was obtained in the same manner as in comparative example 4.

(1) Formation of vias

(1-1) formation of Via hole Pattern Using resist film for sandblasting

The surface of the insulating layer was patterned with a resist film for sandblasting (NCM 250, thickness 50 μm, manufactured by Nikko-Materials Co.) to form a via hole having a diameter of 150 μm.

(1-2) Via hole processing by sandblasting

Next, using alumina abrasive grain slurry #1200 (average particle size 9.5 μm) as abrasive grains, through-hole portions were subjected to blasting using the blasting resist film having the through-hole pattern formed thereon as a mask, to obtain the evaluation substrate 20.

< evaluation of Via diameter >

Good: a through hole can be formed with an opening diameter of 100 μm or less;

x: the through-hole cannot be formed with an opening diameter of 100 μm or less.

< evaluation of stain removability >

The evaluation substrates 1 to 20 obtained in examples and comparative examples were immersed in a Swelling Dip securigant P containing diethylene glycol monobutyl ether manufactured by Amett Japan as a Swelling liquid at 60 ℃ for 5 minutes, and subsequently subjected to a concentrative Compact P (KMnO) manufactured by Amett Japan as a roughening liquid₄: 60g/L, NaOH: 40g/L aqueous Solution) at 80 ℃ for 15 minutes, and finally at 40 ℃ for 5 minutes in Reduction Solution securiganteh P manufactured by Amatt Japan as a neutralizing Solution. Then, the through-hole was observed with an electron microscope, and evaluated according to the following criteria:

good: no resin residue was observed at the bottom of the via;

x: resin residue was observed at the bottom of the through-hole.

< evaluation of halo >

The evaluation substrate after evaluation of the stain removability was observed for a cross section using an FIB-SEM composite apparatus ("SMI 3050 SE" manufactured by SII Nano Technology Co.). In detail, the insulating layer is cut out so as to present a cross section parallel to the thickness direction of the insulating layer and passing through the center of the via bottom of the via hole, using FIB (focused ion beam). The cross section was observed by SEM. In the observed image, a gap portion formed by peeling the insulating layer from the copper foil of the inner layer substrate continuously from the edge of the bottom of the through hole was observed. Therefore, the distance from the edge of the bottom portion of the through hole to the end portion on the outer peripheral side of the gap portion was measured as a halo distance, and evaluated according to the following criteria:

good: the halo distance is less than 5 mu m;

x: the halo distance exceeds 5 μm.

< evaluation of Via-hole workability >

(1) By using CO₂Evaluation of laser Via processability

To utilize CO₂The number of shots required for laser processing to set the depth of the opening to a predetermined depth was evaluated, and the evaluation was performed according to the following criteria:

very good: the number of emissions is 1;

good: the number of shots is 2;

x: the number of emissions is 3 or more.

(2) Evaluation of Via processability Using UV-YAG laser

The number of emissions required to set the depth of the opening to a predetermined depth by UV-YAG processing was evaluated, and the evaluation was performed according to the following criteria:

good: the number of emissions is 20 or less;

x: the number of transmissions exceeds 20.

(3) Evaluation of through-hole processability by sandblasting

The evaluation was performed for the blast time required for removing the insulating layer at the bottom of the opening to expose the conductor layer of the laminate, and was performed according to the following criteria:

very good: the processing time is less than 5 minutes;

good: the processing time is more than 5 minutes and less than 10 minutes;

x: the processing time is more than 10 minutes.

[ Table 2]

[ Table 3]

In the table, "WB" means wet blasting treatment. The content of the inorganic filler is a value obtained when the nonvolatile content in the resin composition is 100 mass%.

Description of the symbols

10 inner layer circuit board

11 supporting substrate

12 metal layer

10a main surface

21 support body

22 insulating layer

30 opening part

40 through hole

50 groove

60 metal foil

61 holes

70 dry film

71 hole

80 fill vias

22U of the surface of the insulating layer opposite to the metal layer

220 bottom of through hole

Center of bottom of 220C through hole

240 color changing part

Edge of via bottom of 250 via

260 gap part

270 end portion on the outer peripheral side of the gap portion

Depth of opening part (a)

b diameter of opening part (diameter of through hole)

c total value of thickness of mask and depth of opening

Wb distance of halo from the edge of the via bottom.

Claims

1. A method of manufacturing a printed wiring board, comprising in order:

(B) and a step of forming a through hole by blasting the opening with abrasive grains.

2. The method for manufacturing a printed wiring board according to claim 1, wherein the abrasive grains have an average particle diameter of 10 μm or less.

3. The method for manufacturing a printed wiring board according to claim 1, wherein the depth of the opening is 50% or more and 95% or less of the thickness of the insulating layer.

4. The method of manufacturing a printed wiring board according to claim 1,

the step (B) is a step of forming a through hole by causing abrasive grains to collide with the bottom surface of the opening through the mask,

the ratio of the sum of the thickness of the mask and the depth of the opening to the opening diameter of the through hole (sum/opening diameter) is 3 or less.

5. The method for manufacturing a printed wiring board according to claim 1, wherein the insulating layer has an elastic modulus of 0.1GPa or more at 23 ℃.

6. The method for manufacturing a printed wiring board according to claim 1, wherein the resin composition contains an inorganic filler.

7. The method for manufacturing a printed wiring board according to claim 6, wherein the content of the inorganic filler is 20% by mass or more, assuming that the nonvolatile content in the resin composition is 100% by mass.

8. The method for manufacturing a printed wiring board according to claim 1, wherein the resin composition contains a curable resin.

9. The method for manufacturing a printed wiring board according to claim 8, wherein the content of the curable resin is 10% by mass or more, assuming that the nonvolatile component in the resin composition is 100% by mass.

10. The method for manufacturing a printed wiring board according to claim 8, wherein the curable resin comprises an epoxy resin and a curing agent.

11. The method for manufacturing a printed wiring board according to claim 10, wherein the curing agent is one or more selected from the group consisting of a phenol-based resin, an active ester-based resin, and a cyanate ester-based resin.

12. The method for manufacturing a printed wiring board according to claim 1, wherein the laser is CO₂Laser or UV-YAG laser.