JP6770789B2 - Manufacturing method of adhesive sheet with protective film - Google Patents

Description

The present invention relates to a method for manufacturing an adhesive sheet with a protective film. Further, the present invention relates to a method for manufacturing a printed wiring board, an adhesive sheet with a protective film, and an adhesive sheet.

As a manufacturing technique for printed wiring boards, a manufacturing method by a build-up method in which insulating layers and conductor layers (circuit layers) are alternately stacked is known. In the manufacturing method by the build-up method, the insulating layer is generally formed by laminating the resin composition layer on the inner layer substrate using an adhesive sheet or the like containing the resin composition layer and curing the resin composition layer. .. For example, Patent Document 1 discloses an adhesive sheet containing a copper foil and a resin composition layer made of a specific resin composition formed on the copper foil.

Further, reflecting the tendency of lightness, thinness, shortness and smallness in recent years, the printed wiring board is required to have a low coefficient of thermal expansion of the insulating layer. Patent Document 2 discloses an adhesive sheet containing a resin composition layer having a high content of an inorganic filler in order to contribute to lowering the coefficient of thermal expansion of the insulating layer.

JP-A-2002-359444 Japanese Unexamined Patent Publication No. 2014-24961

In the build-up manufacturing method, a circuit is formed on the insulating layer after the insulating layer is formed. When an adhesive sheet having a resin composition layer formed on a metal foil is used, the metal foil can be used to form a circuit according to a subtractive method or a modified semi-additive method. Further, when an adhesive sheet having a resin composition layer formed on a plastic film is used, it is possible to form a circuit according to a semi-additive method after peeling the plastic film. In such a case, from the viewpoint of widespread use of the conventional batch laminating equipment, the laminating of the adhesive sheet and the inner layer substrate and the curing of the resin composition layer are often carried out by a vacuum heat press treatment, and in this case, the resin is generally used. The melt viscosity of the composition layer is set to a relatively high value.

The present inventors have formed an inorganic filler content in the resin composition layer in order to realize an insulating layer having a low thermal expansion rate in an adhesive sheet in which a resin composition layer having a relatively high melt viscosity is formed on a support. Attempted to increase. However, the present inventors have found that when the adhesive sheet is slit in the manufacturing process of the adhesive sheet, resin chipping (resin chip) may occur at the slit end portion.

In order to suppress the occurrence of resin chipping at the time of slitting, it is conceivable to perform slitting with a protective film provided on the surface of the resin composition layer that is not bonded to the support, but the present invention has the following obstacles. They found. Specifically, when suppressing the occurrence of resin chipping by the protective film, it is necessary to laminate the protective film so that the protective film and the resin composition layer exhibit sufficient adhesive strength, but it is added in the process of laminating the protective film. The heat generated may cause the adhesive sheet to curl, which may significantly reduce the handleability of the adhesive sheet.

The present invention is a technique for producing an adhesive sheet with a protective film capable of suppressing the occurrence of resin chipping and curling at the time of slitting even when a resin composition layer having a high content of an inorganic filler is used. Is to provide.

As a result of diligent studies on the above problems, the present inventors have found that the above problems can be solved by a method including the following specific steps, and have completed the present invention.

That is, the present invention includes the following contents.
[1] A method for producing an adhesive sheet with a protective film, which comprises the following steps (a-1) to (a-3).
(A-1) Step of preparing an adhesive sheet composed of a support and a resin composition layer bonded to the support (a-2) A protective film is provided so as to be bonded to the resin composition layer of the adhesive sheet. A step of preparing an adhesive sheet with a protective film, in which the protective film has an adhesive surface on the side to be joined to the resin composition layer (a-3) A step of slitting the adhesive sheet with a protective film [2] Support The method according to [1], wherein the thickness of the film is 5 μm to 50 μm.
[3] The method according to [1] or [2], wherein the thickness of the resin composition layer is 5 μm to 300 μm.
[4] The method according to any one of [1] to [3], wherein the arithmetic average roughness (Ra) of the surface of the support to be joined to the resin composition layer is 50 nm to 350 nm.
[5] The method according to any one of [1] to [4], wherein the protective film has a thickness of 10 μm to 100 μm.
[6] The method according to any one of [1] to [5], wherein the resin composition layer contains an inorganic filler and a thermosetting resin.
[7] The method according to [6], wherein the content of the inorganic filler in the resin composition layer is 60% by mass or more when the non-volatile component in the resin composition layer is 100% by mass.
[8] The method according to any one of [1] to [7], wherein the minimum melt viscosity of the resin composition layer is 8000 poise or more.
[9] The method according to any one of [6] to [8], wherein the resin composition layer contains an inorganic filler having an average particle size of 0.01 μm to 4 μm.
[10] The method according to any one of [6] to [9], wherein the resin composition layer further contains a curing agent.
[11] A method for manufacturing a printed wiring board, which comprises the following steps (b-1) and (b-2).
(B-1) Step of peeling the protective film from the adhesive sheet with a protective film obtained by the method according to any one of [1] to [10] to prepare an adhesive sheet (b-2) On the inner layer substrate In the step [12] step (b-2) of laminating the adhesive sheet so that the resin composition layer of the adhesive sheet is bonded to the inner layer substrate, the adhesive sheet is laminated on the inner layer substrate by vacuum heat pressing. The method for manufacturing a printed wiring board according to [11].
[13] The method for manufacturing a printed wiring board according to [11] or [12], further comprising the following steps (b-3) or (b-3').
(B-3) Step of forming a circuit by a subtractive method or a modified semi-additive method (b-3') A step of forming a circuit by a semi-additive method [14] A support and a resin composition bonded to the support. An adhesive sheet with a protective film including an adhesive sheet made of a material layer and a protective film provided so as to be bonded to the resin composition layer of the adhesive sheet.
The resin composition layer contains an inorganic filler and a thermosetting resin, and contains
The content of the inorganic filler in the resin composition layer is 60% by mass or more when the non-volatile component in the resin composition layer is 100% by mass.
The minimum melt viscosity of the resin composition layer is 8000 poise or more.
An adhesive sheet with a protective film, wherein the protective film has an adhesive surface on the side to be joined to the resin composition layer, and at least one side of the adhesive sheet with the protective film is slit.
[15] The adhesive sheet with a protective film according to [14], wherein the thickness of the support is 5 μm to 50 μm.
[16] The adhesive sheet with a protective film according to [14] or [15], wherein the thickness of the resin composition layer is 5 μm to 300 μm.
[17] The adhesive sheet with a protective film according to any one of [14] to [16], wherein the arithmetic average roughness (Ra) of the surface of the support to be joined to the resin composition layer of the support is 50 nm to 350 nm.
[18] The adhesive sheet with a protective film according to any one of [14] to [17], wherein the protective film has a thickness of 10 μm to 100 μm.
[19] The adhesive sheet with a protective film according to any one of [14] to [18], wherein the resin composition layer contains an inorganic filler having an average particle size of 0.01 μm to 4 μm.
[20] The adhesive sheet with a protective film according to any one of [14] to [19], wherein the resin composition layer further contains a curing agent.
[21] The adhesive sheet with a protective film according to any one of [14] to [20] used in the vacuum heat pressing process.
[22] The adhesive sheet with a protective film according to any one of [14] to [21] for forming a circuit by a subtractive method or a modified semi-additive method.
[23] An adhesive sheet composed of a support and a resin composition layer bonded to the support.
The resin composition layer contains an inorganic filler and a thermosetting resin, and contains
The content of the inorganic filler in the resin composition layer is 60% by mass or more when the non-volatile component in the resin composition layer is 100% by mass.
An adhesive sheet in which the minimum melt viscosity of the resin composition layer is 8000 poise or more, and at least one side of the adhesive sheet is slit.
[24] The adhesive sheet according to [23], wherein the thickness of the support is 5 μm to 50 μm.
[25] The adhesive sheet according to [23] or [24], wherein the thickness of the resin composition layer is 5 μm to 300 μm.
[26] The adhesive sheet according to any one of [23] to [25], wherein the resin composition layer contains an inorganic filler having an average particle size of 0.01 μm to 4 μm.
[27] The adhesive sheet according to any one of [23] to [26], wherein the resin composition layer further contains a curing agent.
[28] The adhesive sheet according to any one of [23] to [27] used in the vacuum heat pressing process.
[29] The adhesive sheet according to any one of [23] to [28] for forming a circuit by a subtractive method or a modified semi-additive method.

According to the present invention, even when a resin composition layer having a high content of an inorganic filler is used, an adhesive sheet with a protective film capable of suppressing the occurrence of resin chipping and curling at the time of slitting can be produced. Can provide the technology to do.

FIG. 1 is a schematic view showing a slit end portion of an adhesive sheet with a protective film.

Before explaining in detail the method for producing an adhesive sheet with a protective film of the present invention, the support used in the present invention and the resin composition for forming the resin composition layer will be described.

<Support>
The support has first and second main surfaces. In the present invention, the first main surface of the support is joined to the resin composition layer.

From the viewpoint of suppressing the occurrence of resin chipping at the time of slitting, the arithmetic mean roughness (Ra) of the first main surface of the support is preferably 50 nm or more, more preferably 70 nm or more, still more preferably 90 nm or more, and further. More preferably, it is 100 nm or more, 110 nm or more, or 120 nm or more. The upper limit of Ra of the first main surface of the support is preferably 350 nm or less, more preferably 340 nm or less, still more preferably 320 nm or less, still more preferably 300 nm or less, particularly preferably, from the viewpoint of forming a fine circuit. Is 280 nm or less, 260 nm or less, or 240 nm or less.

Ra of the second main surface of the support is not particularly limited, but is preferably 300 nm or more, more preferably 320 nm or more, still more preferably 340 nm or more, from the viewpoint of improving the drilling workability by a laser in the production of the printed wiring board. It is 360 nm or more, 380 nm or more, or 400 nm or more. The upper limit of Ra of the second main surface of the support is not particularly limited, but may be usually 1000 nm or less, 900 nm or less, 800 nm or less, and the like.

The arithmetic mean roughness (Ra) of the support surface can be measured using a non-contact surface roughness meter. Examples of the non-contact type surface roughness meter include "WYKO NT3300" manufactured by Becoin Sturments.

As the support, a plastic film or a metal foil is preferably used. In particular, the metal foil is preferable because it can be used as it is as a conductor layer by the subtractive method or the modified semi-additive method. Examples of the material of the metal foil include copper, aluminum and the like, and copper 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, etc.) may be used. You may use it. Examples of the material of the plastic film include polyester such as polyethylene terephthalate (“PET”) and polyethylene naphthalate (“PEN”), acrylic such as polycarbonate (“PC”) and polymethylmethacrylate (PMMA), cyclic polyolefin, and tri. Examples thereof include acetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, and polyimide.

The metal foil may have a single-layer structure, a single metal layer made of different types of metals or alloys, or a multi-layer structure in which two or more alloy layers are laminated. Examples of the metal foil having a multi-layer structure include a metal foil containing a carrier metal foil and an ultrathin metal foil bonded to the carrier metal foil.

The thickness of the metal foil is not particularly limited, but is preferably 50 μm or less, more preferably 45 μm or less, from the viewpoint of forming a fine circuit by the subtractive method and smoothly forming a circuit by the modified semi-additive method. It is still more preferably 40 μm or less, even more preferably 35 μm or less, and particularly preferably 30 μm or less, 28 μm or less, 26 μm or less, 24 μm or less, 22 μm or less, or 20 μm or less. Resin chipping at the time of slitting tends to be particularly remarkable when a thin metal foil is used. In this respect, in the present invention, even when a thin metal foil having a thickness of 18 μm or less, 16 μm or less, 14 μm or less, or 12 μm or less is used, it is possible to suppress the occurrence of resin chipping at the time of slitting. is there. The same thickness as above can be adopted as the thickness of the plastic film.

The lower limit of the thickness of the metal foil is not particularly limited, and may be determined according to the method used for circuit formation, the desired design of the printed wiring board, and the like. The lower limit of the thickness of the metal foil can usually be 5 μm or more, 10 μm or more, and the like. When the metal foil has a multi-layer structure, it is preferable that the thickness of the entire metal foil is in such a range. The same thickness as above can be adopted as the thickness of the plastic film.

The method for producing the metal foil is not particularly limited. The metal foil can be produced by a known method such as an electrolysis method or a rolling method. When a metal foil is produced by using an electrolytic method, the Ra value can be changed by controlling the smoothness of the drum surface, the current density, the plating bath temperature, and the like during the production of the metal foil. The surface of the plastic film on the side to be joined with the resin composition layer may be matted or corona-treated. Further, as the plastic film, a plastic film with a release layer having a release layer on the surface on the side to be joined with the resin composition layer may be used.

A commercially available product may be used as the support. Examples of commercially available metal foils include HLP foils manufactured by JX Nippon Mining & Metals Co., Ltd., JXUT-III foils, and TP-III foils manufactured by Mitsui Metal Mine Co., Ltd. Examples of commercially available plastic films include "SK-1", "AL-5", and "AL-7" manufactured by Lintec Corporation.

<Resin composition>
The resin composition used for forming the resin composition layer preferably contains a large amount of an inorganic filler from the viewpoint of suppressing the thermal expansion coefficient of the obtained insulating layer to be low. The content of the inorganic filler in the resin composition is preferably 50% by mass or more, 55% by mass or more, or 60% by mass or more. As described above, the present inventors have confirmed that when a resin composition layer having a high content of an inorganic filler is used, the problem of resin chipping at the time of slitting becomes particularly remarkable. In this respect, according to the present invention, even when a resin composition layer having a high content of inorganic filler is used, resin chipping at the time of slitting is unlikely to occur. Therefore, in the present invention, the content of the inorganic filler in the resin composition can be further increased without causing the problem of resin chipping. For example, the content of the inorganic filler in the resin composition is 62% by mass or more, 64% by mass or more, 66% by mass or more, 68% by mass or more, 70% by mass or more, 72% by mass or more, 74% by mass or more. It may be increased to 76% by mass or more, or 78% by mass or more.

The upper limit of the content of the inorganic filler in the resin composition is preferably 95% by mass or less, more preferably 90% by mass or less, still more preferably 85% by mass or less, from the viewpoint of the mechanical strength of the obtained insulating layer. ..

In the present invention, the content of each component in the resin composition is a value when the non-volatile component in the resin composition is 100% by mass, unless otherwise specified.

The material of the inorganic filler is not particularly limited, but for example, silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, water. Aluminum oxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide , Zirconate oxide, barium titanate, barium titanate titanate, barium zirconate titanate, calcium zirconate, zirconate titanate, zirconate titnate phosphate and the like, and silica is particularly suitable. Examples of silica include amorphous silica, fused silica, crystalline silica, synthetic silica, hollow silica and the like. Further, as silica, spherical silica is preferable. The inorganic filler may be used alone or in combination of two or more. Examples of commercially available spherical silica include "SO-C2" and "SO-C1" manufactured by Admatex Co., Ltd., "IMSIL A-8" and "IMSIL A-10" manufactured by Unimin.

The average particle size of the inorganic filler is not particularly limited, but is preferably 4 μm or less, more preferably 3 μm or less, and 2.5 μm or less, 2 μm or less, from the viewpoint of obtaining an insulating layer on which fine wiring can be formed. More preferably, it is 1.5 μm or less, 1 μm or less, 0.7 μm or less, or 0.5 μm or less. On the other hand, from the viewpoint of obtaining a resin varnish having an appropriate viscosity and good handleability, the average particle size of the inorganic filler is preferably 0.01 μm or more, more preferably 0.03 μm or more, 0.05 μm or more, and 0. .07 μm or more, or 0.1 μm or more is more preferable. The average particle size of the inorganic filler can be measured by a laser diffraction / scattering method based on the Mie scattering theory. Specifically, it can be measured by creating a particle size distribution of the inorganic filler on a volume basis with a laser diffraction type particle size distribution measuring device and using the median diameter as the average particle size. As the measurement sample, an inorganic filler dispersed in water by ultrasonic waves can be preferably used. As the laser diffraction type particle size distribution measuring device, "LA-500", "LA-750", "LA-950", etc. manufactured by HORIBA, Ltd. can be used.

From the viewpoint of obtaining an insulating layer capable of forming fine wiring on the insulating layer, it is preferable to use an inorganic filler from which coarse particles have been removed by classification. In one embodiment, it is preferable to use an inorganic filler from which particles having a particle size of 10 μm or more have been removed by classification, and more preferably to use an inorganic filler from which particles having a particle size of 5 μm or more have been removed by classification. It is more preferable to use an inorganic filler from which particles having a particle size of 3 μm or more have been removed by classification.

In one preferred embodiment, an inorganic filler having an average particle size of 0.01 μm to 4 μm and having particles having a particle size of 10 μm or more removed by classification is used.

From the viewpoint of enhancing moisture resistance and dispersibility, the inorganic filler is an aminosilane-based coupling agent, an epoxysilane-based coupling agent, a mercaptosilane-based coupling agent, a silane-based coupling agent, an organosilazane compound, and a titanate-based coupling agent. It is preferable that the treatment is performed with one or more surface treatment agents such as. Commercially available surface treatment agents include, for example, "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. and "KBM803" (3-mercaptopropyltrimethoxy) manufactured by Shin-Etsu Chemical Co., Ltd. Silane), "KBE903" (3-aminopropyltriethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., Shin-Etsu Chemical Co., Ltd. Examples thereof include "SZ-31" (hexamethyldisilazane) manufactured by Co., Ltd.

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. Carbon content per unit surface area of the inorganic filler, from the viewpoint of improving dispersibility of the inorganic filler is preferably 0.02 mg / ^{m 2} or more, 0.1 mg / ^{m 2} or more preferably, 0.2 mg / ^{m 2} The above is more preferable. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin varnish and the melt viscosity in the sheet form, 1 mg / m ² or less is preferable, 0.8 mg / m ² or less is more preferable, and 0.5 mg / m ² or less is further preferable. preferable.

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 (for example, methyl ethyl ketone (MEK)). Specifically, a sufficient amount of MEK as a solvent is added to the inorganic filler surface-treated with a surface treatment agent, and ultrasonic cleaning is performed at 25 ° C. for 5 minutes. After removing the supernatant and drying the solid content, the amount of carbon per unit surface area of the inorganic filler can be measured using a carbon analyzer. As the carbon analyzer, "EMIA-320V" manufactured by HORIBA, Ltd. or the like can be used.

The resin composition layer preferably further contains a thermosetting resin. Thus, in one embodiment, the resin composition comprises an inorganic filler and a thermosetting resin. As the thermosetting resin, any thermosetting resin that can be used when forming the insulating layer of the printed wiring board can be used, and among them, the epoxy resin is preferable.

-Epoxy resin-
Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, and naphthol novolac type epoxy resin. Phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolac type epoxy resin, biphenyl type Epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexanedimethanol type epoxy resin, naphthylene ether type epoxy resin, bird Examples thereof include a methylol type epoxy resin and a tetraphenylethane type epoxy resin. One type of epoxy resin may be used alone, or two or more types may be used in combination.

The epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. When the non-volatile component of the epoxy resin is 100% by mass, at least 50% by mass or more is preferably an epoxy resin having two or more epoxy groups in one molecule. Among them, an epoxy resin having two or more epoxy groups in one molecule and liquid at a temperature of 20 ° C. (hereinafter referred to as "liquid epoxy resin") and three or more epoxy groups in one molecule. It is preferable to contain a solid epoxy resin (hereinafter referred to as "solid epoxy resin") at a temperature of 20 ° C. By using a liquid epoxy resin and a solid epoxy resin in combination as the epoxy resin, a resin composition layer having excellent flexibility can be obtained. In addition, the breaking strength of the obtained insulating layer is also improved.

As the liquid epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, phenol novolac type epoxy resin, and epoxy resin having a butadiene structure are preferable, and bisphenol A type epoxy resin. , Bisphenol F type epoxy resin, and naphthalene type epoxy resin are more preferable. Specific examples of the liquid epoxy resin include "HP4032", "HP4032H", "HP4032D", "HP4032SS" (naphthalene type epoxy resin) manufactured by DIC Co., Ltd., and "jER828EL" (bisphenol A) manufactured by Mitsubishi Chemical Corporation. Type epoxy resin), "jER807" (bisphenol F type epoxy resin), "jER152" (phenol novolac type epoxy resin), "ZX1059" (bisphenol A type epoxy resin and bisphenol F type epoxy resin) manufactured by Nippon Steel & Sumitomo Metal Corporation (Mixed product), "EX-721" (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation, and "PB-3600" (epoxy resin having a butadiene structure) manufactured by Daicel Chemical Industry Co., Ltd. .. These may be used individually by 1 type, and may be used in combination of 2 or more type.

Examples of the solid epoxy resin include naphthalene type tetrafunctional epoxy resin, cresol novolac type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, and naphthylene ether type epoxy resin. Anthracene type epoxy resin, bisphenol A type epoxy resin, and tetraphenylethane type epoxy resin are preferable, and naphthalene type tetrafunctional epoxy resin, dicyclopentadiene type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, and naphthylene ether type epoxy resin. , Bisphenol A type epoxy resin and tetraphenylethane type epoxy resin are more preferable. Specific examples of the solid epoxy resin include "HP-4700", "HP-4710" (naphthalene type tetrafunctional epoxy resin), "N-690" (cresol novolac type epoxy resin), and "Kresornovolak type epoxy resin" manufactured by DIC Co., Ltd. N-695 "(cresol novolac type epoxy resin)," HP-7200 "(dicyclopentadiene type epoxy resin)," EXA7311 "," EXA7311-G3 "," EXA7311-G4 "," EXA7311-G4S "," HP6000 (Naftylene ether type epoxy resin), "EPPN-502H" (Trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd., "NC7000L" (naphthol novolac type epoxy resin), "NC3000H", "NC3000", "NC3000L", "NC3100" (biphenyl type epoxy resin), "ESN475V" (naphthol type epoxy resin) manufactured by Nippon Steel & Sumitomo Metal Corporation, "ESN485" (naphthol novolac type epoxy resin), manufactured by Mitsubishi Chemical Co., Ltd. "YX4000H", "YL6121" (biphenyl type epoxy resin), "YX4000HK" (bixilenol type epoxy resin), "YX8800" (anthracene type epoxy resin), "PG-100" manufactured by Osaka Gas Chemical Co., Ltd., " "CG-500", "YL7800" (fluorene type epoxy resin) manufactured by Mitsubishi Chemical Corporation, "jER1010" (solid bisphenol A type epoxy resin) manufactured by Mitsubishi Chemical Corporation, "jER1031S" (tetraphenylethane type) Epoxy resin) and the like. These may be used individually by 1 type, and may be used in combination of 2 or more type.

When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, their quantity ratio (liquid epoxy resin: solid epoxy resin) is in the range of 1: 0.1 to 1:10 in terms of mass ratio. preferable. By setting the amount ratio of the liquid epoxy resin to the solid epoxy resin within such a range, i) sufficient flexibility is obtained when used in the form of an adhesive sheet, and handleability is improved, ii) sufficient. An effect such as being able to obtain an insulating layer having an excellent breaking strength can be obtained. The amount ratio of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin: solid epoxy resin) is more preferably in the range of 1: 0.3 to 1: 9 in terms of mass ratio, 1: 0.6 to 1: 9. The range of 8 is more preferable.

The content of the epoxy resin in the resin composition is preferably 3% by mass to 40% by mass, more preferably 5% by mass to 35% by mass, and further preferably 10% by mass to 30% by mass.

The epoxy equivalent of the epoxy resin is preferably 50 to 5000, more preferably 50 to 3000, still more preferably 80 to 2000, and even more preferably 110 to 1000. Within this range, the crosslink density of the cured product becomes sufficient, and an insulating layer having a small surface roughness can be provided. The epoxy equivalent can be measured according to JIS K7236, and is the mass of the resin containing 1 equivalent of the epoxy group.

The weight average molecular weight of the epoxy resin is preferably 100 to 5000, more preferably 250 to 3000, and even more preferably 400 to 1500. Here, the weight average molecular weight of the epoxy resin is a polystyrene-equivalent weight average molecular weight measured by a gel permeation chromatography (GPC) method.

-Hardener-
The resin composition may further contain a curing agent. The curing agent is not particularly limited as long as it has a function of curing the epoxy resin, and for example, a phenol-based curing agent, a naphthol-based curing agent, an active ester-based curing agent, a benzoxazine-based curing agent, a cyanate ester-based curing agent, and a curing agent. Examples include carbodiimide-based curing agents. The curing agent may be used alone or in combination of two or more.

As the phenol-based curing agent and the naphthol-based curing agent, a phenol-based curing agent having a novolak structure or a naphthol-based curing agent having a novolak structure is preferable from the viewpoint of heat resistance and water resistance. Further, from the viewpoint of adhesion strength with the conductor layer, a nitrogen-containing phenol-based curing agent or a nitrogen-containing naphthol-based curing agent is preferable, and a triazine structure-containing phenol-based curing agent or a triazine structure-containing naphthol-based curing agent is more preferable. Of these, a triazine structure-containing phenol novolac resin is preferable from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion strength with the conductor layer. These may be used individually by 1 type, and may be used in combination of 2 or more type. Specific examples of the phenol-based curing agent and the naphthol-based curing agent include, for example, "MEH-7700", "MEH-7810", "MEH-7851" manufactured by Meiwa Kasei Co., Ltd., and Nippon Kayaku Co., Ltd. "NHN", "CBN", "GPH", "SN-170", "SN-180", "SN-190", "SN-475", "SN-485", manufactured by Nippon Steel & Sumitomo Metal Corporation, "SN-495", "SN-375", "SN-395", "LA-7052", "LA-7054", "LA-3018", "LA-1356", "TD2090" manufactured by DIC Co., Ltd. , Etc. can be mentioned.

The active ester-based curing agent is not particularly limited, but generally contains an ester group having high reactive activity such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds in one molecule. A compound having two or more esters is preferably used. The active ester-based curing agent is preferably obtained by a condensation reaction between a carboxylic acid compound and / or a thiocarboxylic acid compound and a hydroxy compound and / or a thiol compound. In particular, from the viewpoint of improving heat resistance, an active ester-based curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferable, and an active ester-based curing agent 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, pyromellitic acid and the like. Examples of the phenol compound or naphthol compound include hydroquinone, resorcin, bisphenol A, bisphenol F, bisphenol S, phenolphthaline, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol, and m-cresol. , P-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, fluoroglusin, benzene Examples thereof include triol, dicyclopentadiene type diphenol compound, and phenol novolac. Here, the "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing two phenol molecules with one dicyclopentadiene molecule.

Examples of the active ester-based curing agent include an active ester compound containing a dicyclopentadiene-type diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated product of phenol novolac, and an active ester compound containing a benzoyl product of phenol novolac. Of these, an active ester compound containing a naphthalene structure and an active ester compound containing a dicyclopentadiene-type diphenol structure are more preferable. These may be used individually by 1 type, and may be used in combination of 2 or more type. The "dicyclopentadiene-type diphenol structure" represents a divalent structural unit composed of phenylene-dicyclopentalene-phenylene.

Commercially available products of active ester-based curing agents include "EXB9451", "EXB9460", "EXB9460S", "HPC8000-65T" (manufactured by DIC Co., Ltd.) as active ester compounds containing a dicyclopentadiene type diphenol structure. "EXB9416-70BK" (manufactured by DIC Co., Ltd.) as an active ester compound containing a naphthalene structure, "DC808" (manufactured by Mitsubishi Chemical Co., Ltd.) as an active ester compound containing an acetylated product of phenol novolac, and a benzoylated product of phenol novolac. Examples of the active ester compound contained include "YLH1026" (manufactured by Mitsubishi Chemical Corporation).

Specific examples of the benzoxazine-based curing agent include "HFB2006M" manufactured by Showa Polymer Co., Ltd., "Pd" and "FA" manufactured by Shikoku Chemicals Corporation.

The cyanate ester-based curing agent is not particularly limited, and for example, a novolak type (phenol novolac type, alkylphenol novolac type, etc.) cyanate ester-based curing agent, a dicyclopentadiene type cyanate ester-based curing agent, a bisphenol type (bisphenol A type, etc.) Examples thereof include bisphenol F type, bisphenol S type, etc.) cyanate ester-based curing agents, and prepolymers in which these are partially triazined. Specific examples include bisphenol A disicyanate, polyphenol cyanate (oligo (3-methylene-1,5-phenylene cyanate)), 4,4'-methylenebis (2,6-dimethylphenyl cyanate), 4,4'-ethylidene diphenyl. Disianate, Hexafluorobisphenol A Disianate, 2,2-bis (4-Cyanate) phenylpropane, 1,1-bis (4-Cyanate phenylmethane), Bis (4-Cyanate-3,5-dimethylphenyl) methane, Bifunctional cyanate resins such as 1,3-bis (4-cyanatephenyl-1- (methylethylidene)) benzene, bis (4-cyanatephenyl) thioether, and bis (4-cyanatephenyl) ether, phenol novolac and cresol novolac. Examples thereof include polyfunctional cyanate resins derived from the above, and prepolymers in which these cyanate resins are partially triazined. Commercially available cyanate ester-based curing agents include "PT30" and "PT60" (both phenol novolac type polyfunctional cyanate ester resins) and "BA230" (part or all of bisphenol A disicanate) manufactured by Ronza Japan Co., Ltd. Is a prepolymer that has been triadinated to form a trimer) and the like.

Specific examples of the carbodiimide-based curing agent include "V-03" and "V-07" manufactured by Nisshinbo Chemical Co., Ltd.

The amount ratio of the epoxy resin to the curing agent is the ratio of [total number of epoxy groups in the epoxy resin]: [total number of reactive groups in the curing agent] from the viewpoint of improving the mechanical strength and water resistance of the obtained insulating layer. The range of 1: 0.2 to 1: 2 is preferable, the range of 1: 0.3 to 1: 1.5 is more preferable, and the range of 1: 0.4 to 1: 1 is further preferable. Here, the reactive group of the curing agent is an active hydroxyl group, an active ester group, or the like, and differs depending on the type of the curing agent. The total number of epoxy groups in the epoxy resin is the total number of all epoxy resins obtained by dividing the solid content mass of each epoxy resin by the epoxy equivalent, and the total number of reactive groups in the curing agent is The value obtained by dividing the solid content mass of each curing agent by the reaction group equivalent is the total value for all the curing agents.

In one embodiment, the resin composition contains the above-mentioned inorganic filler, epoxy resin and curing agent. Among them, the resin composition preferably contains silica as an inorganic filler and a mixture of a liquid epoxy resin and a solid epoxy resin as an epoxy resin (the mass ratio of liquid epoxy resin: solid epoxy resin is preferably 1: 0.1 to 1). : 10, more preferably 1: 0.3 to 1: 9, still more preferably 1: 0.6 to 1: 8) as a curing agent, a phenol-based curing agent, a naphthol-based curing agent, an active ester-based curing agent, and the like. It is preferable to contain at least one selected from the group consisting of cyanate ester-based curing agents. As for the resin composition layer containing such a specific component in combination, the suitable contents of the inorganic filler, the epoxy resin, and the curing agent are as described above.

If necessary, the resin composition may further contain one or more additives selected from the group consisting of thermoplastic resins, curing accelerators, flame retardants and organic fillers.

-Thermoplastic resin-
Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamideimide resin, polyetherimide resin, polysulfone resin, polyethersulfone resin, polyphenylene ether resin, polycarbonate resin, and polyether. Examples include ether ketone resin and polyester resin. The thermoplastic resin may be used alone or in combination of two or more.

The polystyrene-equivalent weight average molecular weight of the thermoplastic resin is preferably in the range of 8,000 to 70,000, more preferably in the range of 10,000 to 60,000, and even more preferably in the range of 20,000 to 60,000. The polystyrene-equivalent weight average molecular weight of the thermoplastic resin is measured by gel permeation chromatography (GPC). Specifically, the polystyrene-equivalent weight average molecular weight of the thermoplastic resin is determined by using LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device and Shodex K-800P / K- by Showa Denko Corporation as a column. 804L / K-804L can be measured using chloroform or the like as a mobile phase at a column temperature of 40 ° C. and calculated using a standard polystyrene calibration curve.

Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenol acetphenone skeleton, novolak skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantan skeleton, and terpen Examples thereof include phenoxy resins having one or more skeletons selected from the group consisting of skeletons and trimethylcyclohexane skeletons. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. The phenoxy resin may be used alone or in combination of two or more. Specific examples of the phenoxy resin include "1256" and "4250" (both bisphenol A skeleton-containing phenoxy resin), "YX8100" (bisphenol S skeleton-containing phenoxy resin), and "YX6954" manufactured by Mitsubishi Chemical Corporation. Bisphenol acetophenone skeleton-containing phenoxy resin), and in addition, "FX280" and "FX293" manufactured by Nippon Steel & Sumitomo Metal Corporation, "YL7553", "YL6794", "YL7213" manufactured by Mitsubishi Chemical Corporation, Examples thereof include "YL7290" and "YL7482".

Specific examples of the polyvinyl acetal resin include Electrified Butyral 4000-2, 5000-A, 6000-C, 6000-EP manufactured by Denki Kagaku Kogyo Co., Ltd., Eslek BH series and BX series manufactured by Sekisui Chemical Co., Ltd. Examples include the KS series, BL series, and BM series.

Specific examples of the polyimide resin include "Ricacoat SN20" and "Ricacoat PN20" manufactured by New Japan Chemical Co., Ltd. Specific examples of the polyimide resin include a linear polyimide obtained by reacting a bifunctional hydroxyl group-terminated polybutadiene, a diisocyanate compound and a tetrabasic acid anhydride (described in JP-A-2006-37083), and a polysiloxane skeleton. Examples thereof include modified polyimides such as contained polyimides (described in JP-A-2002-12667 and JP-A-2000-319386).

Specific examples of the polyamide-imide resin include "Vilomax HR11NN" and "Vilomax HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of the polyamide-imide resin include modified polyamide-imides such as polysiloxane skeleton-containing polyamide-imides “KS9100” and “KS9300” manufactured by Hitachi Chemical Industries, Ltd.

Specific examples of the polyether sulfone resin include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

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

The content of the thermoplastic resin in the resin composition is preferably 0.1% by mass to 20% by mass, more preferably 0.5% by mass to 10% by mass, and further preferably 1% by mass to 5% by mass. ..

-Curing accelerator-
Examples of the curing accelerator include phosphorus-based curing accelerators, amine-based curing accelerators, imidazole-based curing accelerators, guanidine-based curing accelerators, and the like, and phosphorus-based curing accelerators, amine-based curing accelerators, and imidazole-based curing agents. Curing accelerators are preferred. The curing accelerator may be used alone or in combination of two or more. The content of the curing accelerator in the resin composition layer is preferably in the range of 0.05% by mass to 3% by mass when the total of the non-volatile components of the epoxy resin and the curing agent is 100% by mass.

-Flame retardant-
Examples of the flame retardant include an organic phosphorus flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a silicone flame retardant, and a metal hydroxide. The flame retardant may be used alone or in combination of two or more. The content of the flame retardant in the resin composition is not particularly limited, but is preferably 0.5% by mass to 10% by mass, and more preferably 1% by mass to 9% by mass.

-Organic filler-
As the organic filler, any organic filler that can be used when forming the insulating layer of the printed wiring board may be used, and examples thereof include rubber particles, polyamide fine particles, and silicone particles, and rubber particles are preferable.

The rubber particles are not particularly limited as long as they are fine particles of a resin that is insoluble and insoluble in an organic solvent by chemically cross-linking a resin exhibiting rubber elasticity. For example, acrylonitrile butadiene rubber particles, butadiene rubber particles, and the like. Acrylo rubber particles and the like can be mentioned. Specifically, the rubber particles include XER-91 (manufactured by Nippon Synthetic Rubber Co., Ltd.), Staphyroid AC3355, AC3816, AC3816N, AC3832, AC4030, AC3364, IM101 (manufactured by Aica Kogyo Co., Ltd.) , EXL2602 (all manufactured by Kureha Chemical Industry Co., Ltd.) and the like.

The average particle size of the organic filler is preferably in the range of 0.005 μm to 1 μm, more preferably in the range of 0.2 μm to 0.6 μm. The average particle size of the organic filler can be measured using a dynamic light scattering method. For example, the organic filler is uniformly dispersed in an appropriate organic solvent by ultrasonic waves or the like, and the particle size distribution of the organic filler is measured by mass using a concentrated particle size analyzer (“FPAR-1000” manufactured by Otsuka Electronics Co., Ltd.). It can be measured by creating a standard and using the median diameter as the average particle size. The content of the organic filler in the resin composition layer is preferably 1% by mass to 10% by mass, more preferably 2% by mass to 5% by mass.

-Other ingredients-
The resin composition may contain other components, if necessary. Examples of such other components include addition of organometallic compounds such as organocopper compounds, organozinc compounds and organocobalt compounds, and resins such as thickeners, defoamers, leveling agents, adhesion imparting agents and colorants. Examples include agents.

Hereinafter, the present invention will be described in detail according to its preferred embodiment.

[Manufacturing method of adhesive sheet with protective film]
The method for producing an adhesive sheet with a protective film of the present invention includes the following steps (a-1) to (a-3).
(A-1) Step of preparing an adhesive sheet composed of a support and a resin composition layer bonded to the support (a-2) A protective film is provided so as to be bonded to the resin composition layer of the adhesive sheet. A step of preparing an adhesive sheet with a protective film, in which the protective film has an adhesive surface on the side to be joined to the resin composition layer (a-3) A step of slitting the adhesive sheet with a protective film.

<Step (a-1)>
In step (a-1), an adhesive sheet composed of a support and a resin composition layer bonded to the support is prepared.

The resin composition used for forming the support and the resin composition layer is as described above.

In one embodiment, the adhesive sheet can be prepared by providing a resin composition layer so as to join with the first main surface of the support. Hereinafter, such an embodiment is also referred to as a “first embodiment”.

In the first embodiment, the resin composition layer can be provided by a known method. For example, a resin varnish in which a resin composition is dissolved in a solvent is prepared, the resin varnish is applied to the first main surface of the support using a coating device such as a die coater, and the resin varnish is dried to form a resin composition. A material layer can be provided.

Examples of the solvent used for preparing the resin varnish include ketones such as acetone, methyl ethyl ketone (MEK) and cyclohexanone, ethers such as cellosolve, butylcarbitol and propylene glycol monomethyl ether, ethyl acetate, butyl acetate, cellosolve acetate and propylene. Examples thereof include acetic acid esters such as glycol monomethyl ether acetate and carbitol acetate, aromatic hydrocarbons such as toluene and xylene, and amide solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone. The solvent may be used alone or in combination of two or more.

The resin varnish may be dried by a known drying method such as heating or blowing hot air. If a large amount of solvent remains in the resin composition layer, it causes swelling after curing. Therefore, the amount of residual solvent in the resin composition layer is usually 10% by mass or less, preferably 5% by mass or less, more preferably 3. Dry to a mass% or less, 2% by mass or less, or 1% by mass or less. Although it depends on the boiling point of the solvent in the resin varnish, for example, when a resin varnish containing a solvent of 30% by mass to 60% by mass is used, the resin composition layer is dried at 50 ° C. to 150 ° C. for 3 to 10 minutes. Can be formed.

In another embodiment, the adhesive sheet can be prepared by using an adhesive film containing a resin composition layer and providing the resin composition layer so as to be bonded to the first main surface of the support. Hereinafter, such an embodiment is also referred to as a “second embodiment”.

In the second embodiment, the adhesive film containing the other support and the resin composition layer bonded to the other support is bonded so that the resin composition layer is bonded to the first main surface of the support. Laminate on the support.

For the adhesive film, for example, a resin varnish in which a resin composition is dissolved in a solvent is prepared, the resin varnish is applied onto a support using a die coater or the like, and the resin varnish is dried to form a resin composition layer. It can be prepared by letting it. The same solvent as above may be used.

In the second embodiment, the bonding between the adhesive film and the support has good workability and a uniform contact state can be easily obtained. Therefore, the adhesive film is laminated on the support by roll pressure bonding, press pressure bonding, or the like. It is preferable to do so. Above all, the vacuum laminating method of laminating under reduced pressure is more preferable. The laminating process can be carried out using a commercially available vacuum laminator. Examples of commercially available vacuum laminators include a vacuum pressurizing laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nichigo Morton Co., Ltd., and the like.

Regardless of the first embodiment or the second embodiment, the minimum melt viscosity of the resin composition layer is preferably 8000 from the viewpoint of suppressing the exudation of the resin during the vacuum heat pressing process in the production of the printed wiring board. Poise or more, more preferably 8500 poise or more, or 9000 poise or more. The upper limit of the minimum melt viscosity of the resin composition layer is preferably 100,000 poise or less, more preferably 70,000 poise or less, and 40,000 poise from the viewpoint of achieving good stackability (circuit embedding property) when manufacturing a printed wiring board. Below, it is 38,000 poises or less, 36,000 poises or less, 34,000 poises or less, or 32,000 poises or less.

The "minimum melt viscosity" of the resin composition layer means the lowest viscosity exhibited by the resin composition layer when the resin of the resin composition layer is melted. Specifically, when the resin layer is heated at a constant temperature rise rate to melt the resin, the melt viscosity decreases with increasing temperature in the initial stage, and then increases with temperature increase above a certain temperature. .. The "minimum melt viscosity" means the melt viscosity of such a minimum point. The minimum melt viscosity of the resin composition layer can be measured by a dynamic viscoelastic method, and can be measured, for example, according to the method described in <Measurement of minimum melt viscosity of resin composition layer> described later.

The minimum melt viscosity of the resin composition layer can be adjusted, for example, by changing the drying conditions of the resin varnish.

When the adhesive sheet is prepared according to the second embodiment, when the minimum melt viscosity of the resin composition layer of the adhesive film to be used is lower than the above desired range, another support is used after laminating the support and the adhesive film. It may be removed and the resin composition layer may be heat-treated so as to have a desired minimum melt viscosity.

The thickness of the resin composition layer may be determined according to the intended design of the printed wiring board, but from the viewpoint of reducing the thickness of the printed wiring board, it is preferably 300 μm or less, more preferably 250 μm or less, still more preferably. It is 200 μm or less, 180 μm or less, 160 μm or less, 140 μm or less, 120 μm or less, 100 μm or less, 80 μm or less, 60 μm or less, or 40 μm or less. The lower limit of the thickness of the resin composition layer is preferably 5 μm or more, more preferably 10 μm or more, 15 μm or more, or 20 μm or more from the viewpoint of improving the embedding property of the circuit.

<Step (a-2)>
In step (a-2), a protective film is provided so as to be bonded to the resin composition layer of the adhesive sheet, and an adhesive sheet with a protective film is prepared. Here, the protective film is characterized by having an adhesive surface on the side to be bonded to the resin composition layer.

In the manufacture of printed wiring boards, the lamination of the adhesive sheet and the inner layer substrate and the curing of the resin composition layer are often carried out by a vacuum heat press treatment from the viewpoint of widespread use of the conventional batch lamination equipment. In particular, when the circuit is formed according to the subtractive method or the modified semi-additive method, it is preferably carried out by vacuum heat pressing. The adhesive sheet used for such applications has a resin composition layer having a high melt viscosity as described above, and generally has a two-layer structure of a support \ resin composition layer.

As described above, if the content of the inorganic filler in the resin composition layer is increased in order to realize an insulating layer having a low coefficient of thermal expansion, the resin composition layer becomes brittle, and the slit end portion is formed during slitting in the process of manufacturing the adhesive sheet. The present inventors have found that resin chipping (resin chip) may occur in the above.

In order to suppress the occurrence of resin chipping at the time of slitting, a protective film is provided on the surface of the resin composition layer that is not bonded to the support, and the slit is formed in a three-layer structure of the support, the resin composition layer, and the protective film. It is also possible to do it. However, in such a case, there are the following obstacles. Specifically, when suppressing the occurrence of resin chipping by the protective film, it is necessary to laminate the protective film so that the protective film and the resin composition layer exhibit sufficient adhesive strength, but it is added in the process of laminating the protective film. The present inventors have found that the heat generated may cause the adhesive sheet to curl, which may significantly reduce the handleability of the adhesive sheet.

In the present invention, a specific protective film having an adhesive surface on the side to be joined with the resin composition layer is used. As a result, it is possible to advantageously suppress the occurrence of resin chipping and curl at the time of slitting.

Examples of the protective film having an adhesive surface include an adhesive coating type protective film formed by coating a base resin layer with an adhesive, and self-adhesive formed by co-extruding a base resin and an adhesive resin. A mold protective film can be mentioned.

Regardless of whether it is an adhesive coating type or a self-adhesive type, the base resin of the protective film includes, for example, polyolefins such as polyethylene, polypropylene and polyvinyl chloride, polyesters such as PET and PEN, polycarbonate (PC) and polyimide. And so on. In one preferred embodiment, the substrate resin comprises one or more selected from the group consisting of polyethylene, polypropylene and polyethylene terephthalate.

In the pressure-sensitive adhesive coating type protective film, the pressure-sensitive adhesive is not particularly limited as long as it can suppress the occurrence of resin chipping and curl at the time of slitting, and is, for example, acrylic resin-based pressure-sensitive adhesive, epoxy resin-based pressure-sensitive adhesive, and silicone. Examples include rubber adhesives. In one preferred embodiment, the pressure-sensitive adhesive comprises one or more selected from the group consisting of acrylic resin-based pressure-sensitive adhesives, epoxy resin-based pressure-sensitive adhesives, and silicone rubber-based pressure-sensitive adhesives.

In the self-adhesive protective film, the adhesive resin is not particularly limited as long as it can suppress the occurrence of resin chipping and curl at the time of slitting, and is, for example, an ethylene / vinyl acetate copolymer or a polyolefin resin (for example, direct resin). Chain low density polyethylene). In one preferred embodiment, the pressure-sensitive adhesive resin comprises one or more selected from the group consisting of ethylene-vinyl acetate copolymers and polyolefin-based resins.

The thickness of the protective film is not particularly limited regardless of whether it is an adhesive coating type or a self-adhesive type, but is preferably 10 μm or more, more preferably 20 μm or more, 25 μm or more, 30 μm or more, or 35 μm or more. The upper limit of the thickness of the protective film is not particularly limited, but is preferably 100 μm or less, more preferably 90 μm or less, 80 μm or less, 70 μm or less, or 60 μm or less.

Above all, a self-adhesive protective film is preferable as the protective film from the viewpoint that an insulating layer having good adhesion to the underlying conductor layer can be formed during the production of the printed wiring board.

In the step (a-2), the protective film can be laminated on the adhesive sheet so as to be bonded to the resin composition layer of the adhesive sheet. As a result, an adhesive sheet with a protective film can be obtained.

In the adhesive sheet with a protective film obtained in the step (a-2), the adhesion strength between the protective film and the resin composition layer is preferably 2.5 gf / cm from the viewpoint of suppressing the occurrence of resin chipping at the time of slitting. The above is more preferably 2.6 gf / cm or more, still more preferably 2.8 gf / cm or more, or 3.0 gf / cm or more. Regarding the usual protective film (without adhesive surface) used in the manufacture of printed wiring boards, it is necessary to laminate the protective film and the adhesive sheet under high heating temperature conditions in order to achieve such adhesion strength. There is. On the other hand, in the present invention using a protective film having an adhesive surface, it is possible to realize the above-mentioned adhesion strength even when laminating under mild temperature conditions (details will be described later). In the present invention, the adhesion strength between the protective film and the resin composition layer is 4.0 gf / cm or more, 5.0 gf / cm or more, 6.0 gf / cm by changing the type of the pressure-sensitive adhesive or the pressure-sensitive adhesive resin. As described above, it can be advantageously increased to 7.0 gf / cm or more, 8.0 gf / cm or more, 9.0 gf / cm or more, or 10.0 gf / cm or more. The upper limit of the adhesion strength between the protective film and the resin composition layer can be usually 70 gf / cm or less, 50 gf / cm or less, or the like from the viewpoint of suppressing resin peeling when the protective film is peeled off. Here, the resin peeling refers to a phenomenon in which a part of the resin composition layer is peeled off together with the protective film at the slit end portion when the protective film is peeled off after the slit treatment in the step (a-3). The adhesion strength between the protective film and the resin composition layer can be measured according to the description of <Measurement of adhesion strength between the resin composition layer and the protective film> described later.

Laminating the protective film and the adhesive sheet has good workability and makes it easy to obtain a uniform contact state. Therefore, it is preferable to laminate the protective film on the adhesive sheet by roll pressure bonding, press pressure bonding, or the like.

The laminating process may be carried out under heating conditions. In such a case, it is important to set the heating temperature within a range in which the occurrence of curl can be suppressed. Although it depends on the composition of the resin composition layer and the type of protective film, the heating temperature is preferably 70 ° C. or lower, more preferably 65 ° C. or lower, still more preferably 60 ° C. or lower, 55 ° C. or lower, 50 ° C. or lower, 45 ° C. Below, or below 40 ° C. In the present invention, even when such a low temperature condition is adopted, the desired adhesion strength can be realized. The lower limit of the heating temperature is not particularly limited, but may be usually 20 ° C. or higher, 25 ° C. or higher, 30 ° C. or higher, or the like.

The crimping pressure and crimping time of the laminating treatment are not particularly limited as long as the desired adhesion strength can be obtained, and may be appropriately determined. For example, the crimping pressure may be in the range of 0.1 kgf / cm ^{2 to} 18 kgf / cm ² (0.0098 MPa to 1.77 MPa), and the crimping time may be in the range of 5 seconds to 400 seconds. The laminating treatment may be carried out under reduced pressure conditions (for example, 26.7 hPa or less). The laminating process can be performed using a commercially available vacuum laminator. Commercially available vacuum laminators are as described above.

<Step (a-3)>
In step (a-3), the adhesive sheet with a protective film is slit. As a result, an adhesive sheet with a protective film having a predetermined width can be obtained.

The adhesive sheet with a protective film obtained in the step (a-2) may be attached to the step (a-3) as it is, or may be wound into a roll and stored and then attached to the step (a-3). You may.

The step (a-3) may be carried out using a known slitter (for example, a slitter provided with a disk-shaped cutter) that can be used for producing an adhesive sheet for a printed wiring board. In the present invention, it is possible to advantageously suppress the occurrence of resin chipping at the time of slitting, regardless of the type of slitter.

In the step (a-3), the slit speed is preferably 2 m / min or more, more preferably 4 m / min or more, still more preferably 5 m / min or more, 6 m / min or more, 7 m / min or more from the viewpoint of productivity. , 8 m / min or more, 9 m / min or more, or 10 m / min or more. In the present invention, even when such a high slit speed is adopted, the occurrence of resin chipping can be suppressed. The upper limit of the slit speed is not particularly limited, but may be usually 100 m / min or less, 80 m / min or less, or the like.

In addition, in the step (a-3), the adhesive sheet with a protective film attached to the slit treatment (that is, the adhesive sheet with a protective film obtained in the step (a-2)) causes resin chipping at the time of slitting. From the viewpoint of further suppression, it is preferable to satisfy the following dimensional conditions. Specifically, when the width of the support is Wm [mm], the width of the resin composition layer is Wr [mm], and the width of the protective film is Wp [mm].
i) Wm ≧ Wr, and ii) Wp ≧ Wr
It is preferable to satisfy. The "width" of the support, the resin composition layer, and the protective film means the dimensions of the support, the resin composition layer, and the protective film in the direction perpendicular to the slit direction.

Condition i) is preferably Wm> Wr, more preferably Wm ≧ Wr + 10, still more preferably Wm ≧ Wr + 20, or Wm ≧ Wr + 30, from the viewpoint of further suppressing the occurrence of resin chipping at the time of slitting. Condition i) is preferably Wm ≦ Wr + 100, Wm ≦ Wr + 80, or Wm ≦ Wr + 60 from the viewpoint of productivity.

Condition ii) is preferably Wp> Wr, more preferably Wp ≧ Wr + 5, still more preferably Wp ≧ Wr + 10, Wp ≧ Wr + 15, or Wp ≧ Wr + 20 from the viewpoint of further suppressing the occurrence of resin chipping at the time of slitting. Is. The condition ii) is preferably Wp ≦ Wr + 100, Wp ≦ Wr + 80, Wp ≦ Wr + 60, or Wp ≦ Wr + 40 from the viewpoint of productivity.

In particular, when i) Wm> Wr and ii) Wp> Wr are satisfied at the same time, the support and the adhesive surface of the protective film are in close contact with each other so as to wrap the resin composition layer, and the occurrence of resin chipping at the time of slitting is remarkable. It is possible to suppress it.

Assuming that the width of the adhesive sheet with the protective film obtained in the step (a-3) is W [mm], the closer the W / Wr value is to 1, the more remarkable the occurrence of resin chipping at the time of slitting. In the present invention, it is possible to suppress the occurrence of resin chipping at the time of slitting even when the W / Wr value is 0.9 or more. In the present invention, the value of W / Wr may be increased to 0.91 or more, 0.92 or more, 0.93 or more, 0.94 or more, or 0.95 or more. The value of W / Wr can be usually less than 1, 0.99 or less, 0.98 or less, 0.97 or less, etc. from the viewpoint of suppressing the occurrence of resin chipping at the time of slitting.

[Manufacturing method of printed wiring board]
A printed wiring board can be manufactured using the adhesive sheet with a protective film obtained by the method of the present invention.

In one embodiment, the method for manufacturing a printed wiring board of the present invention includes the following steps (b-1) and (b-2).
(B-1) A step of peeling the protective film from the adhesive sheet with a protective film obtained by the method of the present invention to prepare an adhesive sheet (b-2) An adhesive sheet is placed on an inner layer substrate, and the resin composition of the adhesive sheet. The process of laminating the material layer so that it is bonded to the inner layer substrate

<Step (b-1)>
In step (b-1), the protective film is peeled off from the adhesive sheet with a protective film obtained by the method of the present invention to prepare an adhesive sheet.

The protective film may be peeled off manually or mechanically using an automatic peeling device or the like.

<Step (b-2)>
In the step (b-2), the adhesive sheet is laminated on the inner layer substrate so that the resin composition layer of the adhesive sheet is bonded to the inner layer substrate.

In the present invention, the "inner layer substrate" is mainly a substrate such as a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a heat-curable polyphenylene ether substrate, or pattern processing on one side or both sides of the substrate. A circuit board on which a formed conductor layer (circuit) is formed. Further, the inner layer circuit board of the intermediate product in which the insulating layer and / or the conductor layer should be further formed when the printed wiring board is manufactured is also included in the "inner layer board" in the present invention. When the printed wiring board is a circuit board with built-in components, an inner layer board with built-in components may be used.

In the step (b-2), the bonding of the adhesive sheet and the inner layer substrate is preferably carried out by a vacuum heat press treatment. Therefore, in a preferred embodiment of the present invention, the adhesive sheet is laminated on the inner layer substrate by vacuum heat pressing.

Hereinafter, an embodiment in which an adhesive sheet is laminated on both sides of the inner layer substrate by a vacuum heat press process will be described.

First, a laminated structure in which the inner layer substrate is arranged so that the resin composition layer and the inner layer substrate are bonded between the two adhesive sheets is prepared, and the laminated structure is set in the vacuum heat press device.

The laminated structure is preferably set in a vacuum heat press device via a cushion paper, a metal plate such as a stainless plate (SUS plate), a release film, or the like. The laminated structure is, for example, laminated in the order of cushion paper / metal plate / release film / laminated structure (that is, adhesive sheet / inner layer substrate / adhesive sheet) / release film / metal plate / cushion paper in the vacuum heat pressing apparatus. It is set. Here, the symbol "/" means that the components shown so as to sandwich the symbol "/" are arranged so as to be in contact with each other (the same applies hereinafter in the description of the laminated structure and the like).

Next, a vacuum heat press process is performed in which the laminated structure is heat-bonded under reduced pressure conditions.

The vacuum heat press treatment can be carried out by using a conventionally known vacuum heat press device that presses the laminated structure from both sides of the laminated structure by a metal plate such as a heated SUS plate. Examples of commercially available vacuum heat press devices include "MNPC-V-750-5-200" manufactured by Meiki Seisakusho Co., Ltd. and "VH1-1603" manufactured by Kitagawa Seiki Co., Ltd.

The vacuum heat pressing process may be performed only once, or may be repeated twice or more.

In the vacuum heat pressing process, the crimping pressure (pressing pressure) is preferably 5 kgf / cm ^{2 to} 80 kgf / cm ² (0.49 MPa to 7.9 MPa), more preferably 10 kgf / cm ^{2 to} 60 kgf / cm ² (0. It is 98 MPa to 5.9 MPa).

In the vacuum heat pressing process, the atmospheric pressure, that is, the pressure at the time of depressurization in the chamber in which the laminated structure to be processed is stored is preferably 3 × 10 ⁻² MPa or less, more preferably 1 × 10 ⁻² MPa or less. Is.

In the vacuum heat press treatment, the heating temperature (T) varies depending on the composition of the resin composition layer, but is usually 150 ° C. or higher, preferably 160 ° C. or higher, more preferably 170 ° C. or higher, or 180 ° C. or higher. .. The upper limit of the heating temperature (T) is not particularly limited, but may be usually 240 ° C. or lower.

From the viewpoint of suppressing cracks and strains, the vacuum heat press treatment is preferably carried out while increasing the temperature stepwise or continuously and / or lowering the temperature stepwise or continuously. In such a case, it is preferable that the maximum temperature reached satisfies the above desired temperature condition.

By the vacuum heat pressing process, the resin composition layer is cured to form an insulating layer. Therefore, in the present embodiment, a laminated board having a layer structure of a support / insulating layer / inner layer substrate / insulating layer / support can be obtained. An adhesive sheet may be laminated on only one side of the inner layer substrate to obtain a laminated plate having a layer structure of a support / insulating layer / inner layer substrate.

When an adhesive sheet with a protective film whose support is a metal foil is used, the method for manufacturing a printed wiring board of the present invention may further include the following step (b-3).
(B-3) Step of forming a circuit by a subtractive method or a modified semi-additive method

In the step (b-3), a circuit can be formed by a subtractive method or a modified semi-additive method by using a metal foil derived from an adhesive sheet with a protective film.

In the subtractive method, an unnecessary portion (non-circuit forming portion) of the metal foil is selectively removed by etching or the like to form a circuit. Circuit formation by the subtractive method may be carried out according to a known procedure. For example, circuit formation by the subtractive method involves i) providing an etching resist on the surface of the metal foil (that is, the second main surface), ii) exposing and developing the etching resist to form a wiring pattern, and iii. It can be carried out by a method including) etching and removing the exposed metal foil portion, and iv) removing the etching resist.

In the modified semi-additive method, the non-circuit-forming portion of the metal foil is protected by a plating resist, a metal such as copper is thickened on the circuit-forming portion by electrolytic plating, and then the plating resist is removed to remove the metal other than the circuit-forming portion. The foil is removed by etching to form a circuit. Circuit formation by the modified semi-additive method may be carried out according to a known procedure. For example, circuit formation by the modified semi-additive method involves i) providing a plating resist on the surface of the metal foil (that is, the second main surface), ii) exposing and developing the plating resist to form a wiring pattern. It can be carried out by a method including iii) electrolytic plating through a plating resist, iv) removing the plating resist, and v) etching and removing a metal foil other than the circuit forming portion. If the metal foil derived from the adhesive sheet with a protective film is thick, etching or the like so that the metal foil has a desired thickness (usually 5 μm or less, 4 μm or less, or 3 μm or less) before i) above. The entire surface of the metal foil may be thinned.

When an adhesive sheet with a protective film whose support is a plastic film is used, the method for manufacturing a printed wiring board of the present invention may further include the following step (b-3').
(B-3') Step of forming a circuit by the semi-additive method

In the semi-additive method, a circuit is formed by plating or the like after peeling the plastic film. Circuit formation by the semi-additive method may be carried out according to a known procedure. For example, circuit formation by the semi-additive method is as follows: i) roughening the surface of the insulating layer, ii) forming a seed layer by electroless plating, iii) providing a plating resist on the seed layer, iv) plating resist. To form a wiring pattern by exposing and developing, v) electrolytically plating through a plating resist, vi) removing the plating resist, vii) etching and removing the seed layer other than the circuit forming part. It can be carried out by a method including ,.

In the method for manufacturing a printed wiring board of the present invention, (A) a step of drilling a hole and (B) a step of performing a desmear treatment may be further carried out. These steps can be performed according to various methods known to those skilled in the art, which are used in the manufacture of printed wiring boards.

[Adhesive sheet with protective film]
The present invention also provides an adhesive sheet with a protective film.

The adhesive sheet with a protective film of the present invention
An adhesive sheet composed of a support and a resin composition layer bonded to the support,
Includes a protective film provided to bond with the resin composition layer of the adhesive sheet.
The resin composition layer contains an inorganic filler and a thermosetting resin, and contains
The content of the inorganic filler in the resin composition layer is 60% by mass or more when the non-volatile component in the resin composition layer is 100% by mass.
The minimum melt viscosity of the resin composition layer is 8000 poise or more.
The protective film has an adhesive surface on the side to be joined to the resin composition layer, and at least one side of the adhesive sheet with the protective film is slit.

The resin composition used for forming the support and the resin composition layer is as described in the above <support> and <resin composition>. Regarding the physical properties of the resin composition layer and the like (for example, the thickness of the resin composition layer, the minimum melt viscosity, the adhesion strength between the resin composition layer and the protective film, etc.), refer to the above [Method for manufacturing an adhesive sheet with a protective film]. As described.

The adhesive sheet with a protective film of the present invention has at least one side slit. The slit end portion of the adhesive sheet with a protective film of the present invention will be described with reference to FIG. FIG. 1 shows a slit of an adhesive sheet with a protective film including a support 1, a resin composition layer 2 bonded to the support 1, and a protective film 3 provided on the resin composition layer 2. The ends are shown schematically.

At the end of the slit, the end faces of the support 1, the resin composition layer 2, and the protective film 3 are substantially aligned. From the viewpoint that it can be suitably used in manufacturing a printed wiring board, it is preferable that the deviation between the end face of the support and the end face of the resin composition layer at the slit end (“ΔW” in FIG. 1) is small. In one preferred embodiment, the deviation ΔW between the end face of the support and the end face of the resin composition layer at the slit end is preferably 2 mm or less, more preferably 1.5 mm or less, 1.0 mm or less, 0.8 mm or less. , 0.6 mm or less, or 0.5 mm or less. The smaller the lower limit of the deviation ΔW, the more preferable, and it may be 0 mm. Note that FIG. 1 shows a mode in which the end face of the support protrudes from the end face of the resin composition layer, but also in a mode in which the end face of the resin composition layer protrudes from the end face of the support. It is preferable to satisfy the above conditions.

The adhesive sheet with a protective film of the present invention can advantageously suppress the occurrence of curl. For example, when the adhesive sheet with a protective film of the present invention is cut out to a size of 490 mm square, the sheet does not curl into a roll shape. In one preferred embodiment, when the adhesive sheet with a protective film of the present invention is cut out to a size of 490 mm square, the radius of curvature of the bent portion of the sheet is preferably 80 mm or more, more preferably 100 mm or more, still more preferably 200 mm. The above is 400 mm or more, 600 mm or more, 800 mm or more, or 1000 mm or more. The upper limit of the radius of curvature is not particularly limited, and a larger one is preferable.

The adhesive sheet with a protective film of the present invention can be suitably used for forming a printed wiring board by laminating it on an inner layer substrate by a vacuum heat press treatment. The adhesive sheet with a protective film of the present invention can also be suitably used for forming a circuit by a subtractive method or a semi-modified additive method by using a metal foil as a support.

[Adhesive sheet]
An adhesive sheet can be obtained by peeling the protective film from the adhesive sheet with a protective film of the present invention.

The adhesive sheet of the present invention
Includes a support and a resin composition layer bonded to the support
The resin composition layer contains an inorganic filler and a thermosetting resin, and contains
The content of the inorganic filler in the resin composition layer is 60% by mass or more when the non-volatile component in the resin composition layer is 100% by mass.
The resin composition layer has a minimum melt viscosity of 8000 poise or more, and at least one side of the adhesive sheet is slit.

The resin composition used for forming the support and the resin composition layer is as described in the above <support> and <resin composition>. Further, the physical properties of the resin composition layer and the like (for example, the thickness of the resin composition layer, the minimum melt viscosity, etc.) are as described in the above [Method for manufacturing an adhesive sheet with a protective film].

The adhesive sheet of the present invention has at least one side slit. The preferred range of the deviation ΔW between the end face of the support and the end face of the resin composition layer at the slit end is as described above.

The adhesive sheet of the present invention can advantageously suppress the occurrence of curl. The radius of curvature of the bent portion of the adhesive sheet is as described for the adhesive sheet with a protective film.

The adhesive sheet of the present invention can advantageously suppress the occurrence of resin chipping at the slit end. In one preferred embodiment, in the adhesive sheet of the present invention, the maximum value of the resin chipping width from the end face of the resin composition layer at the slit end is preferably 100 μm or less, more preferably 80 μm or less, still more preferably 60 μm. Hereinafter, it is 50 μm or less, 40 μm or less, or 30 μm or less. The smaller the resin chipping width is, the more preferable it is, and it may be 0 μm.

The adhesive sheet of the present invention can be suitably used for forming a printed wiring board by laminating it on an inner layer substrate by a vacuum heat press treatment. The adhesive sheet of the present invention can also be suitably used for forming a circuit by a subtractive method or a semi-modified additive method by using a metal foil as a support.

Hereinafter, the present invention will be specifically described with reference to Examples, but the present invention is not limited to these Examples. In the following description, "parts" and "%" mean "parts by mass" and "% by mass", respectively, unless otherwise specified.

<Measurement method / evaluation method>
First, various measurement methods and evaluation methods will be described.

<Measurement of Arithmetic Mean Roughness (Ra) on the surface of the support>
For the surface of the support used in the following Examples and Comparative Examples on the side to be joined with the resin composition layer, a non-contact type surface roughness meter (“WYKO NT3300” manufactured by Becoin Sturments) was used in VSI contact mode, 50. The Ra value was determined from the numerical value obtained by setting the measurement range to 121 μm × 92 μm with a magnification lens. The average value of 10 randomly selected points was calculated for each sample.

<Measurement of minimum melt viscosity of resin composition layer>
The melt viscosity of the resin composition layer of the adhesive sheet produced in the following Examples and Comparative Examples was measured using a dynamic viscoelasticity measuring device (“Rheosol-G3000” manufactured by UBM Co., Ltd.). About 1 g of the sample resin composition, a parallel plate having a diameter of 18 mm was used to raise the temperature from a starting temperature of 60 ° C. to 200 ° C. at a heating rate of 5 ° C./min, measuring temperature interval 2.5 ° C., frequency 1 Hz, The dynamic viscoelasticity was measured under the measurement condition of strain 1 deg, and the minimum melt viscosity (poise) was calculated.

<Measurement of adhesion strength between resin composition layer and protective film>
The adhesive sheet with a protective film produced in the following Examples and Comparative Examples was cut into a width of 30 mm and a length of 100 mm to obtain a measurement sample. High-grade thick paper (Co., Ltd.) cut to a width of 27 mm and a length of 100 mm by attaching a double-sided tape ("Nystack" manufactured by Nichiban Co., Ltd.) with a width of 25 mm and a length of 95 mm to the surface of the support of the obtained sample. It was adhered to Jitsuta's "Konayuki 210 (ultra-thick)"). One end of the protective film was peeled off and grasped with a gripper, and the load when the protective film was peeled off by 30 mm in the vertical direction at a speed of 50 mm / min at room temperature (23 ° C.) was measured to determine the peeling strength. A tensile tester (“AC-50C-SL” manufactured by TSE Co., Ltd.) was used for the measurement.

<Evaluation of resin chipping>
Visually observe the slit ends of the adhesive sheet with the roll-shaped protective film or the roll-shaped adhesive sheet manufactured in the following Examples and Comparative Examples, and the support and the resin composition layer are in close contact with each other over all the lengths of both ends. The case was marked with "○", and the case with some peeling was marked with "x".

<Evaluation of curl>
The adhesive sheet with a roll-shaped protective film or the roll-shaped adhesive sheet produced in the following Examples and Comparative Examples was cut into a 490 mm square sheet and allowed to stand with the support as the lower surface. Then, the case where the sheet was rolled into a roll and curl was generated was designated as "x", and the case where no curl was generated was designated as "○".

<Preparation Example 1> Preparation of resin varnish 1 3 parts of bisphenol type epoxy resin (“ZX1059” manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd., epoxy equivalent about 169, 1: 1 mixture of bisphenol A type and bisphenol F type), bixirenol Type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent about 185) 9 parts, dicyclopentadiene type epoxy resin ("HP7200HH" manufactured by DIC Co., Ltd., epoxy equivalent 280) 12 parts, and phenoxy resin (Mitsubishi) 20 parts of "YL7553BH30" manufactured by Kagaku Co., Ltd. (1: 1 solution of cyclohexanone: MEK having a solid content of 30% by mass) was heated and dissolved in 25 parts of solven varnish with stirring. After cooling to room temperature, 30 parts of an active ester-based curing agent (“HPC8000-65T” manufactured by DIC Co., Ltd., an active group equivalent of about 223, a toluene solution of 65% by mass of a non-volatile component), an amine-based curing accelerator (4-Dimethylaminopyridine (DMAP), MEK solution with a solid content of 5% by mass) 3.5 parts, imidazole-based curing accelerator ("P200H50" manufactured by Mitsubishi Chemical Corporation, imidazole-epoxy resin adduct, non-volatile component 1.2 parts of 50% by mass propylene glycol monomethyl ether solution), flame retardant ("HCA-HQ" manufactured by Sanko Co., Ltd., 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10- Spherical silica (“SO” manufactured by Admatex Co., Ltd.) surface-treated with 2 parts of phosphaphenanthrene-10-oxide (average particle size 2 μm) and an aminosilane-based coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Industry Co., Ltd.) -C1 ", average particle size 0.25 μm, carbon amount 0.36 mg / m ² per unit surface area, particles of 3 μm or more removed by classification) Mix 100 parts, disperse uniformly with a high-speed rotating mixer, and resin varnish. 1 was prepared.

<Preparation Example 2> Preparation of resin varnish 2 5 parts of bisphenol type epoxy resin (“ZX1059” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., epoxy equivalent of about 169, 1: 1 mixture of bisphenol A type and bisphenol F type), bixirenol 10 parts of type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 185), 10 parts of biphenyl type epoxy resin ("NC3000L" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent of 269), and phenoxy resin (Mitsubishi) 10 parts of "YL7553BH30" manufactured by Kagaku Co., Ltd. (1: 1 solution of cyclohexanone: MEK having a solid content of 30% by mass) was heated and dissolved in 30 parts of solvent naphtha with stirring. After cooling to room temperature, 10 parts of an active ester-based curing agent (“HPC8000-65T” manufactured by DIC Co., Ltd., active group equivalent of about 223, toluene solution of 65% by mass of non-volatile component), and a phenolic system containing a triazine structure. Curing agent (hydroxyl equivalent 151, "LA-3018" manufactured by DIC Co., Ltd., 2-methoxypropanol solution having a solid content of 50%), 10 parts, amine-based curing accelerator (DMAP, MEK solution having a solid content of 5% by mass) 2 , 1.6 parts of imidazole-based curing accelerator ("P200H50" manufactured by Mitsubishi Chemical Co., Ltd., adduct of imidazole-epoxy resin, propylene glycol monomethyl ether solution with 50% by mass of non-volatile component), flame retardant (Sanko Co., Ltd.) "HCA-HQ" manufactured by HCA-HQ, average particle size 2 μm), 2 parts, spherical silica surface-treated with phenyltrimethoxysilane (“KBM103” manufactured by Shinetsu Chemical Industry Co., Ltd.) (“SO-C2” manufactured by Admatex Co., Ltd.) , Average particle size 0.5 μm, carbon content per unit surface area 0.34 mg / m ² ) 80 parts, silica (Unimin) surface-treated with an aminosilane-based coupling agent (“KBM573” manufactured by Shinetsu Chemical Industry Co., Ltd.) Ltd. "Imsil a-8", an average particle diameter of 2.2 .mu.m, a carbon amount 0.29 mg ^/ m 2 per unit surface area) 80 parts were mixed and uniformly dispersed in a high-speed rotary mixer to prepare a resin varnish 2.

The compositions of the resin varnishes 1 and 2 are shown in Table 1.

<Example 1>
(1) Preparation of Adhesive Sheet A 550 mm wide roll-shaped copper foil (HLP foil manufactured by JX Nippon Mining & Metals Co., Ltd., thickness 12 μm) was prepared as a support. Hereinafter, the copper foil is also referred to as "copper foil 1". Ra of the first main surface of the copper foil 1 was 180 nm. A resin varnish 1 having a width of 520 mm is applied to the first main surface of the copper foil 1 with a die coater, dried at 80 ° C. to 120 ° C. (average 100 ° C.) for 3 minutes, and a resin composition having a thickness of 15 μm. A layer was formed.
(2) Production of Adhesive Sheet with Protective Film Next, on the surface of the resin composition layer that is not bonded to the copper foil, a protective film (self-adhesive polyethylene film "Tretec 7531" manufactured by Toray Co., Ltd., thickness 30 μm, An adhesive sheet having a width of 540 mm) was laminated at 40 ° C. to obtain an adhesive sheet with a protective film. The obtained adhesive sheet with a protective film was wound into a roll.
(3) Slit of adhesive sheet with protective film After winding in a roll shape, the adhesive sheet with protective film is cutter at a speed of 10 m / min so that the blade of the cutter hits the position 30 mm from the end of the copper foil. It was moved toward the blade surface and slit. Both ends of the sheet were slit to obtain an adhesive sheet (roll length 20 m) with a roll-shaped protective film having a width of 490 mm.

<Example 2>
(1) Preparation of Adhesive Sheet A 550 mm wide roll-shaped copper foil (HLP foil manufactured by JX Nippon Mining & Metals Co., Ltd., thickness 18 μm) was prepared as a support. Hereinafter, the copper foil is also referred to as "copper foil 2". Ra of the first main surface of the copper foil 2 was 160 nm. A resin varnish 2 having a width of 520 mm is applied to the first main surface of the copper foil 2 with a die coater, dried at 80 ° C. to 120 ° C. (average 100 ° C.) for 5 minutes, and a resin composition having a thickness of 50 μm. A layer was formed.
(2) Production of Adhesive Sheet with Protective Film Next, on the surface of the resin composition layer that is not bonded to the copper foil, a protective film (self-adhesive polypropylene film manufactured by Oji Ftex Co., Ltd., thickness 29 μm, width 540 mm) ) Was laminated at 40 ° C. to obtain an adhesive sheet with a protective film. The obtained adhesive sheet with a protective film was wound into a roll.
(3) Slit of Adhesive Sheet with Protective Film In the same manner as in Example 1, the adhesive sheet with protective film was slit to obtain an adhesive sheet with a roll-shaped protective film (roll length 20 m) having a width of 490 mm.

<Example 3>
(1) Preparation of adhesive sheet As a support, a roll-shaped copper foil with a width of 550 mm (copper foil "JXUT-III foil" with a carrier manufactured by JX Nippon Mining & Metals Co., Ltd., ultra-thin copper foil thickness 2 μm, carrier copper A foil thickness of 18 μm) was prepared. Hereinafter, the copper foil is also referred to as "copper foil 3". Ra of the first main surface (ultra-thin copper foil side) of the copper foil 3 was 230 nm. A resin varnish 2 having a width of 520 mm is applied to the first main surface of the copper foil 3 with a die coater, dried at 80 ° C. to 130 ° C. (average 110 ° C.) for 10 minutes, and a resin composition having a thickness of 150 μm. A layer was formed.
(2) Manufacture of Adhesive Sheet with Protective Film Next, on the surface of the resin composition layer that is not bonded to the copper foil, a protective film (self-adhesive polyethylene film "Tretec CF322K5-1" manufactured by Toray Co., Ltd., thickness Adhesive surfaces (40 μm, width 540 mm) were laminated at 40 ° C. to obtain an adhesive sheet with a protective film. The obtained adhesive sheet with a protective film was wound into a roll.
(3) Slit of Adhesive Sheet with Protective Film In the same manner as in Example 1, the adhesive sheet with protective film was slit to obtain an adhesive sheet with a roll-shaped protective film (roll length 20 m) having a width of 490 mm.

<Example 4>
(1) Preparation of Adhesive Sheet A 550 mm wide roll-shaped plastic film (AL5 manufactured by Lintec Corporation, thickness 38 μm) was prepared as a support. Ra of the first main surface of the plastic film was 75 nm. A resin varnish 2 having a width of 520 mm is applied to the first main surface of the plastic film with a die coater, dried at 80 ° C. to 120 ° C. (average 100 ° C.) for 3 minutes, and a resin composition layer having a thickness of 50 μm. Was formed.
(2) Production of Adhesive Sheet with Protective Film Next, on the surface of the resin composition layer that is not bonded to the plastic film, a protective film (self-adhesive polypropylene film manufactured by Oji Ftex Co., Ltd., thickness 29 μm, width 540 mm) ) Was laminated at 40 ° C. to obtain an adhesive sheet with a protective film. The obtained adhesive sheet with a protective film was wound into a roll.
(3) Slit of adhesive sheet with protective film After winding in a roll shape, the adhesive sheet with protective film is cutter at a speed of 10 m / min so that the blade of the cutter hits the position 30 mm from the edge of the plastic film. It was moved toward the blade surface and slit. Both ends of the sheet were slit to obtain an adhesive sheet (roll length 20 m) with a roll-shaped protective film having a width of 490 mm.

<Comparative example 1>
A roll-shaped adhesive sheet (roll length 20 m) having a width of 490 mm was obtained in the same manner as in Example 1 except that the protective film was not used.

<Comparative example 2>
i) Polypropylene film "Alfan MA-411" (thickness 15 μm, width 540 mm) manufactured by Oji F-Tex Co., Ltd. was used as the protective film, and ii) it was not bonded to the copper foil of the resin composition layer. An adhesive sheet with a roll-shaped protective film (roll length 20 m) having a width of 490 mm was obtained in the same manner as in Example 2 except that the rough surface of the protective film was laminated on the surface at 60 ° C.

<Comparative example 3>
i) A polyethylene film "GF-106" (thickness 30 μm, width 540 mm) manufactured by Tamapoli Co., Ltd. was used as the protective film, and ii) the surface of the resin composition layer not bonded to the copper foil. An adhesive sheet with a roll-shaped protective film (roll length 20 m) having a width of 490 mm was obtained in the same manner as in Example 1 except that the protective films were laminated at 75 ° C.

<Comparative example 4>
A roll-shaped adhesive sheet (roll length 20 m) having a width of 490 mm was obtained in the same manner as in Example 3 except that the protective film was not used.

<Comparative example 5>
A roll-shaped adhesive sheet (roll length 20 m) having a width of 490 mm was obtained in the same manner as in Example 4 except that the protective film was not used.

In the adhesive sheets of Comparative Examples 1, 4 and 5 using the resin composition layer having a high content of the inorganic filler, resin chipping occurred at the time of slitting. In order to suppress the occurrence of resin chipping by the protective film, it is necessary to laminate the protective film so that the protective film and the resin composition layer exhibit sufficient adhesive strength (Comparative Example 2), but in the process of laminating the protective film. The applied heat caused the adhesive sheet to curl, and the handleability of the adhesive sheet was significantly reduced (Comparative Example 3).
On the other hand, with respect to the adhesive sheets with protective films of Examples 1 to 4 produced by the method of the present invention, it was possible to suppress the occurrence of resin chipping and curl at the time of slitting.

1 Support 2 Resin composition layer 3 Protective film

Claims (21)

(A -1) A step of preparing an adhesive sheet composed of a support and a resin composition layer bonded to the support, wherein the resin composition layer contains an inorganic filler and a thermosetting resin. ,
(A-2) A step of preparing an adhesive sheet with a protective film by providing a protective film so as to be bonded to the resin composition layer of the adhesive sheet, wherein the protective film has an adhesive surface on the side to be bonded to the resin composition layer. step having, and (a-3) a step of slitting the adhesive sheet with protective films
A method for manufacturing an adhesive sheet with a protective film, including
The content of the inorganic filler in the resin composition layer is 64% by mass or more and 64% by mass or more when the non-volatile component in the resin composition layer is 100% by mass.
A method for producing an adhesive sheet with a protective film, wherein the adhesion strength between the protective film and the resin composition layer measured under the following conditions is 2.5 gf / cm or more and 70 gf / cm or less.
<Measurement conditions>
Temperature: 23 ° C
Peeling speed: 50 mm / min
Peeling direction: vertical direction The thickness of the support is 5 m to 50 m, The method of claim 1. The method according to claim 1 or 2 , wherein the thickness of the resin composition layer is 5 μm to 300 μm. The method according to any one of claims 1 to 3 , wherein the arithmetic mean roughness (Ra) of the surface of the support to be joined to the resin composition layer is 50 nm to 350 nm. The method according to any one of claims 1 to 4 , wherein the thickness of the protective film is 10 μm to 100 μm. The method according to any one of claims 1 to 5 , wherein the minimum melt viscosity of the resin composition layer is 8000 poise or more. The method according to any one of claims 1 to 6 , wherein the resin composition layer contains an inorganic filler having an average particle size of 0.01 μm to 4 μm. The method according to any one of claims 1 to 7 , wherein the resin composition layer further contains a curing agent. The method according to any one of claims 1 to 8 , wherein the adhesive sheet with a protective film prepared in the step (a-2) is wound into a roll and stored, and then attached to the step (a-3). A method for manufacturing a printed wiring board, which comprises the following steps (b-1) and (b-2).
(B-1) A step of peeling the protective film from the adhesive sheet with a protective film obtained by the method according to any one of claims 1 to 9 to prepare an adhesive sheet (b-2) on the inner layer substrate. A step of laminating the adhesive sheet so that the resin composition layer of the adhesive sheet is bonded to the inner layer substrate. In step (b-2), on the inner layer board, an adhesive sheet is laminated with a vacuum hot press process, a method for manufacturing a printed wiring board according to claim 1 0. Further comprising the steps of (b-3) or (b-3 '), the manufacturing method of the printed wiring board according to claim 1 0 or 1 1.
(B-3) Step of forming a circuit by the subtractive method or the modified semi-additive method (b-3') Step of forming a circuit by the semi-additive method An adhesive sheet with a protective film including an adhesive sheet composed of a support and a resin composition layer bonded to the support, and a protective film provided so as to be bonded to the resin composition layer of the adhesive sheet. ,
The resin composition layer contains an inorganic filler and a thermosetting resin, and contains
The content of the inorganic filler in the resin composition layer is, when the non-volatile components of the resin composition layer is 100 mass%, and a 6 4 wt% or more,
The minimum melt viscosity of the resin composition layer is 8000 poise or more.
The protective film has an adhesive surface on the side to be bonded to the resin composition layer .
At least one side of the adhesive sheet with protection film are slit, and
An adhesive sheet with a protective film, wherein the adhesion strength between the protective film and the resin composition layer measured under the following conditions is 2.5 gf / cm or more and 70 gf / cm or less.
<Measurement conditions>
Temperature: 23 ° C
Peeling speed: 50 mm / min
Peeling direction: vertical direction The thickness of the support is 5 m to 50 m, the protective film with the adhesive sheet according to claim 1 3. The adhesive sheet with a protective film according to claim 13 or 14 , wherein the thickness of the resin composition layer is 5 μm to 300 μm. The arithmetic mean roughness of the surface on the side bonded to the supporting body of the resin composition layer (Ra) is 50Nm～350nm, protective film with adhesive sheet according to any one of claims 1 3 to 1 5. The thickness of the protective film is 10 m - 100 m, the protective film with the adhesive sheet according to any one of claims 1 3 to 1 6. Resin composition layer containing an inorganic filler having an average particle size 0.01Myuemu～4myuemu, protective film with adhesive sheet according to any one of claims 1 3-17. Resin composition layer further comprises a curing agent, the protective film with the adhesive sheet according to any one of claims 1 3-18. Adhesive sheets with protective film according to any one of claims 1 3-19 for use in the vacuum heat pressing treatment. Subtractive method or modified protective film with adhesive sheet according to any one of claims 1 3-2 0 for the circuit formed by the semi-additive method.