JP6176294B2 - Resin sheet with support - Google Patents

Description

  The present invention relates to a resin sheet with a support, a method for manufacturing a component-embedded circuit board, and a semiconductor device.

  In recent years, the demand for small high-performance electronic devices such as smartphones and tablet PCs is increasing. Accordingly, there is a demand for further enhancement in function and size of printed wiring boards used in these small electronic devices.

  Components such as bare chips, chip capacitors, and on-chip inductors are mounted on the printed wiring board. Conventionally, such components have been mounted only on the surface circuit of the printed wiring board, but the amount of mounting is limited, which can meet the recent demand for higher functionality and downsizing of the printed wiring board. Was difficult.

  As a solution to the above problem, there has been proposed a component built-in circuit board that is miniaturized (thinned) while increasing the amount of components mounted by incorporating the components in an inner layer circuit board (see Patent Document 1). .

Japanese Patent Laying-Open No. 2015-2295

  By the way, in order to make the component embedding property excellent in the recess (cavity) in which the component of the component built-in circuit board is arranged, the content of the inorganic filler in the resin composition used for component embedding with emphasis on the resin flow Although it is conceivable to use a resin having a relatively low molecular weight while suppressing the above, the coefficient of thermal expansion becomes high and the substrate warpage tends to increase. On the other hand, in order to reduce the substrate warpage of the component built-in circuit board, it is conceivable to increase the content of the inorganic filler in the resin composition, but this increases the melt viscosity and reduces the component embedding property in the cavity. There was a problem that it was easy. The inventors of the present invention have studied to adjust the melt viscosity of the resin composition layer on the side in contact with the circuit board by using a resin composition layer having a plurality of layers. I found it difficult to achieve the performance. Accordingly, the problem to be solved by the present invention is to provide a resin sheet with a support that reduces the warpage of the substrate and is excellent in component embedding.

  As a result of intensive studies on the above problems, the present inventors have determined that the minimum melt viscosity of the resin sheet itself in the resin sheet with a support including the first resin composition layer and the second resin composition layer having different compositions. Was found to be able to solve the above problems by setting the average linear thermal expansion coefficient between 25 ° C. and 150 ° C. of the cured product obtained by curing the resin sheet to 17 ppm / ° C. It came to do. The present invention is based on such novel findings.

That is, the present invention includes the following contents.
[1] A resin sheet with a support comprising a support and a resin sheet provided on the support, the resin sheet comprising a first resin composition layer provided on the support side, and a support A second resin composition layer formed by a second resin composition having a composition different from the first resin composition that is provided on the opposite side of the first resin composition layer. The resin sheet has a minimum melt viscosity of 6000 poise or less, and a cured product layer obtained by curing the resin sheet has an average coefficient of linear thermal expansion between 25 ° C. and 150 ° C. of 17 ppm / ° C. or less. Resin sheet with body.
[2] The resin sheet with a support according to [1], wherein the resin sheet has a thickness of 30 μm or less.
[3] The resin sheet with a support according to [1] or [2], wherein the thickness of the second resin composition layer is 25 μm or less.
[4] The second resin composition contains an inorganic filler, and the content of the inorganic filler is 70% by mass or more when the nonvolatile component in the second resin composition is 100% by mass. The resin sheet with a support according to any one of to [3].
[5] The resin sheet with a support according to any one of [1] to [4], wherein the minimum melt viscosity of the second resin composition layer is lower than the minimum melt viscosity of the first resin composition layer.
[6] The resin sheet with a support according to any one of [1] to [5], which is used for embedding a cavity.
[7] The first resin composition and the second resin composition each include an inorganic filler,
When the average particle diameter of the inorganic filler in the first resin composition is D1 (μm) and the average particle diameter of the inorganic filler in the second resin composition is D2 (μm), D1 and D2 are: The resin sheet with a support according to any one of [1] to [6], which satisfies a relationship of D1 ≦ D2.
[8] The average particle diameter D1 (μm) of the inorganic filler in the first resin composition and the average particle diameter D2 (μm) of the inorganic filler in the second resin composition are D1 ≦ 0.5 ≦. The resin sheet with a support according to [7], which satisfies the relationship of D2.
[9] The resin sheet with a support according to any one of [1] to [8], wherein the second resin composition contains an inorganic filler and a liquid epoxy resin.
[10] The resin sheet with a support according to [9], containing 5 parts by mass or more of a liquid epoxy resin when the inorganic filler is 100 parts by mass.
[11] (A) A circuit board having first and second main surfaces and having a cavity formed between the first and second main surfaces, and a second main surface of the circuit board; Any one of [1] to [10] is provided on the circuit board to which the component is temporarily attached, including the bonded temporary attachment material and the part temporarily attached by the temporary attachment material inside the cavity of the circuit board. A first laminating step of vacuum laminating the resin sheet with a support according to claim 1 so that the second resin composition layer is bonded to the first main surface of the circuit board;
(B) a heat treatment step of heat treating the circuit board on which the resin sheet with the support is laminated;
(C) A resin sheet with a second support including a second support and a second resin sheet that is bonded to the second support after the tacking material is peeled from the second main surface of the circuit board. A second lamination step of vacuum lamination so that the second resin sheet is bonded to the second main surface of the circuit board;
(D) The manufacturing method of the circuit board with a built-in component which includes the process of thermosetting the resin sheet of the resin sheet with a support and the second resin sheet in this order.
[12] The method for manufacturing a component built-in circuit board according to [11], wherein the thickness of the circuit board is 100 μm or more.
[13] The method for manufacturing a circuit board with a built-in component according to [11] or [12], wherein the second resin sheet with a support is the resin sheet with a support according to any one of [1] to [10].
[14] A semiconductor device including a component built-in circuit board manufactured by the method according to any one of [11] to [13].

  ADVANTAGE OF THE INVENTION According to this invention, the resin sheet with a support body which can reduce the curvature of a board | substrate and was excellent in component embedding property can be provided.

FIG. 1A is a schematic diagram (1) showing a procedure for preparing a circuit board on which a component is temporarily attached, which is used in a method for manufacturing a component-embedded circuit board using a resin sheet with a support according to the present invention. FIG. 1B is a schematic diagram (2) showing a procedure for preparing a circuit board on which a component is temporarily used, which is used in the method of manufacturing a component-embedded circuit board using the resin sheet with a support according to the present invention. FIG. 1C is a schematic diagram (3) showing a procedure for preparing a circuit board on which a component is temporarily used, which is used in the method of manufacturing a component-embedded circuit board using the resin sheet with a support according to the present invention. FIG. 1D is a schematic diagram (4) showing a procedure for preparing a circuit board on which a component is temporarily used, which is used in the method for manufacturing a component-embedded circuit board using the resin sheet with a support according to the present invention. FIG. 2 is a schematic view showing one embodiment of the resin sheet with a support of the present invention. FIG. 3A is a schematic diagram (1) for explaining a method of manufacturing a component built-in circuit board using the resin sheet with a support of the present invention in Embodiment 1. Drawing 3B is a mimetic diagram (2) for explaining a manufacturing method of a component built-in circuit board using a resin sheet with a support of the present invention. FIG. 3C is a schematic diagram (3) for explaining the method of manufacturing the component built-in circuit board using the resin sheet with a support according to the present invention. Drawing 3D is a mimetic diagram (4) for explaining a manufacturing method of a component built-in circuit board using a resin sheet with a support of the present invention. FIG. 3E is a schematic diagram (5) for explaining the method of manufacturing the component built-in circuit board using the resin sheet with a support of the present invention. FIG. 3F is a schematic diagram (6) for explaining the method of manufacturing the component built-in circuit board using the resin sheet with a support of the present invention. FIG. 3G is a schematic diagram (7) for explaining the method of manufacturing the component built-in circuit board using the resin sheet with a support according to the present invention.

  Before describing the resin sheet with a support of the present invention in detail, in the resin sheet with a support of the present invention, when forming the first resin composition layer and the second resin composition layer included in the resin sheet The “first resin composition” and “second resin composition” used in the above will be described.

<First resin composition>
The first resin composition forming the first resin composition layer is not particularly limited as long as the cured product has sufficient hardness and insulation. As a 1st resin composition, the composition containing curable resin and its hardening | curing agent is mentioned, for example. As curable resin, the conventionally well-known curable resin used when forming the insulating layer of a printed wiring board can be used, and an epoxy resin is especially preferable. Accordingly, in one embodiment, the first resin composition includes (A) an epoxy resin, (B) a curing agent, and (C) an inorganic filler. The first resin composition may further contain additives such as a thermoplastic resin, a curing accelerator, a flame retardant, and rubber particles as necessary.

  Hereinafter, an epoxy resin, a curing agent, an inorganic filler, and an additive that can be used as the material of the first resin composition will be described.

(A) Epoxy resin Examples of the epoxy resin include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol S type epoxy resins, bisphenol AF type epoxy resins, and other bisphenol type epoxy resins, dicyclopentadiene type epoxy resins, and tris. Phenol type epoxy resin, naphthol novolak type epoxy resin, phenol novolak type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidyl amine type epoxy resin, glycidyl ester type Epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin having butadiene structure, alicyclic ring Epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexanedimethanol type epoxy resin, naphthylene ether type epoxy resin, trimethylol type epoxy resin, tetraphenylethane type epoxy resin and the like. An epoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of the epoxy resin include a bisphenol type epoxy resin, a fluorine type epoxy resin (for example, bisphenol AF type epoxy resin), a dicyclopentadiene type epoxy resin, a naphthalene type epoxy resin, a biphenyl type epoxy resin, and a mixture of these epoxy resins. It is preferable to use one or two or more selected epoxy resins.

  The epoxy resin preferably contains an epoxy resin having two or more epoxy groups in one molecule. When the nonvolatile 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, it has two or more epoxy groups in one molecule, and has a liquid epoxy resin (hereinafter referred to as “liquid epoxy resin”) at a temperature of 20 ° C. 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. A first resin composition having excellent flexibility can be obtained by using a liquid epoxy resin and a solid epoxy resin in combination as the epoxy resin. Moreover, the breaking strength of the cured product of the first resin composition is also improved.

  From the viewpoint of reducing the melt viscosity, a liquid epoxy resin is preferred. Liquid epoxy resins include bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins, naphthalene type epoxy resins, glycidyl ester type epoxy resins, phenol novolac type epoxy resins, and alicyclic epoxy resins having an ester skeleton. And epoxy resins having a butadiene structure are preferred, and bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol AF type epoxy resins and naphthalene type epoxy resins are more preferred. In particular, the aromatic skeleton-containing epoxy resin is also preferable for reducing the average linear thermal expansion coefficient. Specific examples of the liquid epoxy resin include “HP4032”, “HP4032D”, “HP4032SS” (naphthalene type epoxy resin) manufactured by DIC Corporation, “828US”, “jER828EL” (bisphenol A) manufactured by Mitsubishi Chemical Corporation. Type epoxy resin), “jER807” (bisphenol F type epoxy resin), “jER152” (phenol novolac type epoxy resin), “YL7760” (bisphenol AF type epoxy resin), “ZX1059” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. ( Bisphenol A type epoxy resin and bisphenol F type epoxy resin mixture), “EX-721” (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation, “Celoxide 2021P” (ester structure) manufactured by Daicel Corporation Alicyclic Epoxy with Resin), "PB-3600" (epoxy resin having a butadiene structure) and the like. These may be used alone or in combination of two or more.

  From the viewpoint of reducing the average linear thermal expansion coefficient, a solid epoxy resin is preferred. Solid epoxy resins 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, 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, naphthol type epoxy resin, and biphenyl type epoxy resin are more preferable. In particular, the polyfunctional epoxy resin is preferable for increasing the number of crosslinking points and reducing the average linear thermal expansion coefficient. Specific examples of the solid epoxy resin include “HP4032H” (naphthalene type epoxy resin), “HP-4700”, “HP-4710” (naphthalene type tetrafunctional epoxy resin), “N-690” manufactured by DIC Corporation. "(Cresol novolac type epoxy resin)", "N-695" (Cresol novolac type epoxy resin), "HP-7200" (Dicyclopentadiene type epoxy resin), "HP-7200HH", "EXA7311", "EXA7311-G3 ”,“ EXA7311-G4 ”,“ EXA7311-G4S ”,“ HP6000 ”(naphthylene ether type epoxy resin),“ EPPN-502H ”(trisphenol type epoxy resin) manufactured by Nippon Kayaku Co., Ltd.,“ NC7000L ” (Naphthol novolac type epoxy resin), “NC3000 ”,“ NC3000 ”,“ NC3000L ”,“ NC3100 ”(biphenyl type epoxy resin),“ ESN475V ”(naphthol type epoxy resin) manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.,“ ESN485 ”(naphthol novolak type epoxy resin), Mitsubishi “YX4000H”, “YL6121” (biphenyl type epoxy resin), “YX4000HK” (bixylenol type epoxy resin), “YX8800” (anthracene type epoxy resin) manufactured by Kagaku Co., Ltd., “ “PG-100”, “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.

Epoxy resin, if it contains solid epoxy resin and a liquid epoxy resin, the ratio of the mass M _S of a solid epoxy resin to the weight M _L of the liquid epoxy resin (M S _{/ M L)} is 1 to 10 is preferably in the range of . The M S _/ M _L, With such a range, i) moderate tackiness is brought when used in the form of a resin sheet, ii) sufficient flexibility when used in the form of a resin sheet Is obtained, the handleability is improved, and iii) a cured product having sufficient breaking strength can be obtained.

The content of the (A) epoxy resin in the first resin composition is preferably 0.1% by mass or more, more preferably 5% by mass from the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability. As mentioned above, More preferably, it is 10 mass% or more. Although the upper limit of content of an epoxy resin is not specifically limited as long as the effect of this invention is show | played, Preferably it is 50 mass% or less, More preferably, it is 45 mass% or less, More preferably, it is 42 mass% or less.
Therefore, the content of the (A) epoxy resin in the first resin composition is preferably 0.1 to 50% by mass, more preferably 10 to 45% by mass, and still more preferably 20 to 42% by mass. In the present invention, the content of each component in the resin composition (first resin composition and second resin composition) is 100% by mass of the non-volatile component in the resin composition unless otherwise specified. This is the value when

  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. By becoming this range, the crosslinked density of hardened | cured material becomes sufficient and it can bring about an insulating layer with small surface roughness. The epoxy equivalent can be measured according to JIS K7236, and is the mass of a resin containing 1 equivalent of an epoxy group.

  The weight average molecular weight of an epoxy resin becomes like this. Preferably it is 100-5000, More preferably, it is 250-3000, More preferably, it is 400-1500. Here, the weight average molecular weight of the epoxy resin is a weight average molecular weight in terms of polystyrene measured by a gel permeation chromatography (GPC) method.

(B) Curing agent (B) The curing agent is not particularly limited as long as it has a function of curing an epoxy resin. For example, a phenol-based curing agent, a naphthol-based curing agent, an active ester-based curing agent, and a benzoxazine-based curing agent. , Cyanate ester curing agents and carbodiimide curing agents. A hardening | curing agent may be used individually by 1 type, or may use 2 or more types together.

  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 to the conductor layer (circuit wiring), a nitrogen-containing phenol-based curing agent is preferable, and a triazine structure-containing phenol resin and a triazine structure-containing alkyl phenol resin are more preferable. Especially, it is preferable to use a triazine structure containing phenol type hardening | curing agent from a viewpoint which satisfies heat resistance, water resistance, and adhesiveness (peeling strength) with a conductor layer highly.

  Specific examples of the phenol-based curing agent and the naphthol-based curing agent include, for example, “MEH-7700”, “MEH-7810”, “MEH-7785” manufactured by Meiwa Kasei Co., Ltd., and Nippon Kayaku Co., Ltd. “NHN”, “CBN”, “GPH”, “SN170”, “SN180”, “SN190”, “SN475”, “SN485”, “SN495”, “SN375”, “SN395” manufactured by Toto Kasei Co., Ltd. "LA7052", "LA7054", "LA3018", etc. manufactured by DIC Corporation.

  Although there is no restriction | limiting in particular as an active ester type hardening | curing agent, Generally ester groups with high reaction activity, such as phenol ester, thiophenol ester, N-hydroxyamine ester, ester of heterocyclic hydroxy compound, are in 1 molecule. A compound having two or more in the above is preferably used. The active ester 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 curing agent obtained from a carboxylic acid compound and a hydroxy compound is preferable, and an active ester 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, and pyromellitic acid. 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, m- Cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucin, Benzenetriol, dicyclopentadienyl diphenol, phenol novolac and the like.

  Specifically, an active ester compound containing a dicyclopentadienyl diphenol structure, an active ester compound containing a naphthalene structure, an active ester compound containing an acetylated product of a phenol novolak, and an active ester compound containing a benzoylated product of a phenol novolak are preferred. Of these, active ester compounds containing a naphthalene structure and active ester compounds containing a dicyclopentadienyl diphenol structure are more preferred.

  Commercially available active ester curing agents include "EXB9451", "EXB9460", "EXB9460S", "HPC-8000-65T" (DIC Corporation) as active ester compounds containing a dicyclopentadienyl diphenol structure. Manufactured product), "EXB9416-70BK" (manufactured by DIC Corporation) as an active ester compound containing a naphthalene structure, "DC808" (manufactured by Mitsubishi Chemical Corporation) as an active ester compound containing an acetylated product of phenol novolac, Examples of the active ester compound containing a benzoylated compound 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 Kasei Kogyo Co., Ltd.

  Examples of the cyanate ester curing agent include bisphenol A dicyanate, polyphenol cyanate (oligo (3-methylene-1,5-phenylene cyanate)), 4,4′-methylene bis (2,6-dimethylphenyl cyanate), 4, 4'-ethylidenediphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis (4-cyanate) phenylpropane, 1,1-bis (4-cyanatephenylmethane), bis (4-cyanate-3,5- Bifunctional cyanate resins such as dimethylphenyl) methane, 1,3-bis (4-cyanatephenyl-1- (methylethylidene)) benzene, bis (4-cyanatephenyl) thioether, and bis (4-cyanatephenyl) ether; Phenol novolac and Polyfunctional cyanate resin derived from resol novolac, these cyanate resins and partially triazine of prepolymer. Specific examples of the cyanate ester curing agent include “PT30” and “PT60” (both phenol novolak polyfunctional cyanate ester resins) and “BA230” (part or all of bisphenol A dicyanate) manufactured by Lonza Japan Co., Ltd. And the like, and the like, and the like.

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

  In the present invention, the (B) curing agent preferably contains at least one selected from a phenolic curing agent, a cyanate ester curing agent and an active ester curing agent, and includes a triazine structure-containing phenolic resin and a triazine structure. More preferably, it contains at least one selected from a containing alkylphenol-based resin, a cyanate ester-based curing agent, and an active ester-based curing agent.

The content of the curing agent (B) in the first resin composition is not particularly limited, but is preferably 0.1% by mass or more, more preferably 1 from the viewpoint of obtaining an insulating layer having high peel strength and low dielectric loss tangent. It is at least 5% by mass, more preferably at least 5% by mass. The upper limit of the content of (B) the curing agent is not particularly limited as long as the effect of the present invention is exhibited, but is preferably 30% by mass or less, more preferably 25% by mass or less, and further preferably 20% by mass or less. is there.
Therefore, the content of the (B) curing agent in the first resin composition is preferably 0.1 to 30% by mass, more preferably 1 to 25% by mass, and still more preferably 5 to 20% by mass.

  The amount ratio of (A) epoxy resin to (B) curing agent is a ratio of [(A) total number of epoxy groups of epoxy resin]: [(B) total number of reactive groups of curing agent], 1: The range of 0.2 to 1: 2 is preferable, 1: 0.3 to 1: 1.5 is more preferable, and 1: 0.4 to 1: 1 is more preferable. Here, the reactive group of the curing agent is an active hydroxyl group, an active ester group or the like, and varies depending on the type of the curing agent. Moreover, the total number of epoxy groups of the epoxy resin is a value obtained by dividing the solid content mass of each epoxy resin by the epoxy equivalent for the epoxy resin, and the total number of reactive groups of the curing agent is each curing The value obtained by dividing the solid content mass of the agent by the reactive group equivalent is the sum of all the curing agents. By setting the amount ratio of the epoxy resin and the curing agent within such a range, the heat resistance of the cured product of the first resin composition is further improved.

(C) Inorganic filler The material of the inorganic filler is not particularly limited. For example, silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydro Talcite, boehmite, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, Examples thereof include bismuth titanate, titanium oxide, zirconium oxide, barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Of these, silica is particularly preferred. Moreover, spherical silica is preferable as the silica. An inorganic filler may be used individually by 1 type, and may be used in combination of 2 or more type. Examples of commercially available inorganic fillers include “SO-C2”, “SO-C1”, and “SO-C4” manufactured by Admatechs Corporation.

  The average particle diameter of the inorganic filler is not particularly limited, but is preferably 5 μm or less, more preferably 4 μm or less, and even more preferably 3 μm or less, from the viewpoint of obtaining an insulating layer having a small surface roughness and improving the fine wiring formability. 1 μm or less, 0.7 μm or less, 0.5 μm or less, or 0.3 μm or less is even more preferable. On the other hand, from the viewpoint of obtaining a resin varnish having an appropriate viscosity and good handleability when forming a resin varnish using the first resin composition, from the viewpoint of preventing an increase in the melt viscosity of the resin sheet, inorganic The average particle size of the filler is preferably 0.01 μm or more, more preferably 0.03 μm or more, and further preferably 0.05 μm or more, 0.07 μm or more, or 0.1 μm or more. Therefore, the average particle size of the inorganic filler (C) in the first resin composition is preferably 0.5 μm or less, or 0.3 μm or less.

  The average particle diameter of the inorganic filler can be measured by a laser diffraction / scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler can be prepared on a volume basis by a laser diffraction / scattering particle size distribution measuring apparatus, and the median diameter can be measured as the average particle diameter. As the measurement sample, an inorganic filler dispersed in water by ultrasonic waves can be preferably used. As the laser diffraction / scattering particle size distribution measuring apparatus, “LA-500” manufactured by Horiba, Ltd. or the like can be used.

  Inorganic fillers are aminosilane coupling agents, epoxysilane coupling agents, mercaptosilane coupling agents, silane coupling agents, organosilazane compounds, titanate coupling agents from the viewpoint of improving moisture resistance and dispersibility. It is preferable that it is processed with 1 or more types of surface treating agents. Examples of commercially available surface treatment agents include “KBM403” (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., and “KBM803” (3-mercaptopropyltrimethoxy manufactured by Shin-Etsu Chemical Co., Ltd.). Silane), Shin-Etsu Chemical "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical "SZ-31" (hexamethyldisilazane) manufactured by KK, "KBM103" (phenyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM-4803" manufactured by Shin-Etsu Chemical Co., Ltd. (long-chain epoxy type) Silane coupling agent).

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, 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 more preferable from the viewpoint of preventing an increase in the melt viscosity of the resin varnish or the sheet form. 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 the surface treatment agent and ultrasonically cleaned at 25 ° C. for 5 minutes. After removing the supernatant and drying the solid, the carbon amount 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. can be used.

  The content of the inorganic filler (C) in the first resin composition is preferably 70% by mass or less, more preferably 60% by mass or less, from the viewpoint of obtaining an insulating layer capable of forming fine wiring thereon. , 50% by mass or less, or 40% by mass or less. The lower limit of the content of the (C) inorganic filler in the first resin composition is not particularly limited and may be 0% by mass, but is usually 5% by mass or more, 10% by mass or more, and 20% by mass. The above may be used.

  The first resin composition may contain additives such as a thermoplastic resin, a curing accelerator, a flame retardant, and rubber particles in addition to the above (A), (B), and (C).

-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 thereof include thermoplastic resins such as ether ketone resins and polyester resins, and among these, phenoxy resins are preferred. A thermoplastic resin may be used individually by 1 type, or may be used in combination of 2 or more type.

  The polystyrene equivalent weight average molecular weight of the thermoplastic resin is preferably in the range of 5,000 to 100,000, more preferably in the range of 10,000 to 60,000, and still more preferably in the range of 20,000 to 60,000. The weight average molecular weight in terms of polystyrene of the thermoplastic resin is measured by a gel permeation chromatography (GPC) method. Specifically, the polystyrene-reduced weight average molecular weight of the thermoplastic resin is LC-9A / RID-6A manufactured by Shimadzu Corporation as a measuring device, and Shodex K-800P / K- manufactured by Showa Denko KK as a column. 804L / K-804L can be calculated using a standard polystyrene calibration curve by measuring the column temperature at 40 ° C. using chloroform or the like as a mobile phase.

  Examples of the phenoxy resin include bisphenol A skeleton, bisphenol F skeleton, bisphenol S skeleton, bisphenolacetophenone skeleton, novolac skeleton, biphenyl skeleton, fluorene skeleton, dicyclopentadiene skeleton, norbornene skeleton, naphthalene skeleton, anthracene skeleton, adamantane skeleton, terpene Examples thereof include phenoxy resins having a skeleton and one or more skeletons selected from the group consisting of a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. A phenoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type. 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). In addition, “FX280” and “FX293” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., “YL6954BH30”, “YX7553”, “YL7769BH30” manufactured by Mitsubishi Chemical Corporation, “YL6794”, “YL7213”, “YL7290”, “YL7482” and the like.

  Examples of the polyvinyl acetal resin include a polyvinyl formal resin and a polyvinyl butyral resin, and a polyvinyl butyral resin is preferable. Specific examples of the polyvinyl acetal resin include, for example, “Electrical butyral 4000-2”, “Electrical butyral 5000-A”, “Electrical butyral 6000-C” and “Electrical butyral 6000-EP” manufactured by Denki Kagaku Kogyo Co., Ltd. Sekisui Chemical Co., Ltd.'s S-REC BH series, BX series, KS series, BL series, BM series and the like.

  Specific examples of the polyimide resin include “Rika Coat SN20” and “Rika Coat PN20” manufactured by Shin Nippon Rika Co., Ltd. Specific examples of the polyimide resin include linear polyimide obtained by reacting a bifunctional hydroxyl group-terminated polybutadiene, a diisocyanate compound and a tetrabasic acid anhydride (polyimide described in JP-A-2006-37083), a polysiloxane skeleton. Examples thereof include modified polyimides such as containing polyimide (polyimides described in JP-A Nos. 2002-12667 and 2000-319386).

  Specific examples of the polyamide-imide resin include “Bilomax HR11NN” and “Bilomax HR16NN” manufactured by Toyobo Co., Ltd. Specific examples of the polyamideimide resin also include modified polyamideimides such as “KS9100” and “KS9300” (polysiloxane skeleton-containing polyamideimide) manufactured by Hitachi Chemical Co., Ltd.

  Specific examples of the polyethersulfone resin include “PES5003P” manufactured by Sumitomo Chemical Co., Ltd.

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

  Among these, phenoxy resin and polyvinyl acetal resin are preferable as the thermoplastic resin from the viewpoint of obtaining an insulating layer having a lower surface roughness and superior adhesion to the conductor layer in combination with other components. Therefore, in one suitable embodiment, a thermoplastic resin component contains 1 or more types selected from the group which consists of a phenoxy resin and a polyvinyl acetal resin.

  The content of the thermoplastic resin in the first resin composition is preferably 0% by mass to 20% by mass, more preferably 0.5% by mass to 10% by mass, from the viewpoint of appropriately adjusting the melt viscosity of the resin sheet. %, More preferably 1% by mass to 8% 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, phosphorus-based curing accelerators, amine-based curing accelerators, and imidazole-based accelerators. A curing accelerator is preferable, and an amine-based curing accelerator and an imidazole-based curing accelerator are more preferable. A hardening accelerator may be used individually by 1 type, and may be used in combination of 2 or more type.

  Examples of phosphorus curing accelerators include triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl) triphenylphosphonium thiocyanate. , Tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate and the like, and triphenylphosphine and tetrabutylphosphonium decanoate are preferable.

  Examples of amine curing accelerators include trialkylamines such as triethylamine and tributylamine, 4-dimethylaminopyridine, benzyldimethylamine, 2,4,6, -tris (dimethylaminomethyl) phenol, 1,8-diazabicyclo. (5,4,0) -undecene and the like are mentioned, and 4-dimethylaminopyridine and 1,8-diazabicyclo (5,4,0) -undecene are preferable.

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

  Commercially available products may be used as the imidazole curing accelerator, and examples thereof include “P200-H50” manufactured by Mitsubishi Chemical Corporation.

  Examples of the guanidine curing accelerator include dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1- (o-tolyl) guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, Tetramethylguanidine, pentamethylguanidine, 1,5,7-triazabicyclo [4.4.0] dec-5-ene, 7-methyl-1,5,7-triazabicyclo [4.4.0] Deca-5-ene, 1-methyl biguanide, 1-ethyl biguanide, 1-n-butyl biguanide, 1-n-octadecyl biguanide, 1,1-dimethyl biguanide, 1,1-diethyl biguanide, 1-cyclohexyl biguanide, 1 -Allyl biguanide, 1-phenyl biguanide, 1- ( - tolyl) biguanide, and the like, dicyandiamide, 1,5,7-triazabicyclo [4.4.0] dec-5-ene are preferred.

  Although content of the hardening accelerator in a 1st resin composition is not specifically limited, It is preferable to use in 0.05 mass%-3 mass%.

-Flame retardant-
The first resin composition may contain a 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. A flame retardant may be used individually by 1 type, or may use 2 or more types together.

  Commercially available products may be used as the flame retardant, and examples thereof include “HCA-HQ” manufactured by Sanko Co., Ltd.

  The content of the flame retardant in the first resin composition is not particularly limited, but is preferably 0.5% by mass to 20% by mass, more preferably 1% by mass to 15% by mass, and still more preferably 1.5% by mass. More preferably, it is 10 mass%.

-Organic filler-
The first resin composition may further contain an organic filler. As the organic filler, any organic filler that can be used for forming an insulating layer of a printed wiring board may be used. Examples thereof include rubber particles, polyamide fine particles, and silicone particles, and rubber particles are preferable.

  A commercially available product may be used as the rubber particles, and examples thereof include “AC3816N” manufactured by Aika Industry Co., Ltd.

  The content of the organic filler in the first resin composition is preferably 1% by mass to 20% by mass, more preferably 2% by mass to 10% by mass.

  The 1st resin composition may contain other additives other than a flame retardant and an organic filler as needed, and as such other additives, for example, an organic copper compound, organic Examples thereof include organic metal compounds such as zinc compounds and organic cobalt compounds, and resin additives such as organic fillers, thickeners, antifoaming agents, leveling agents, adhesion imparting agents, and coloring agents.

<Second resin composition>
The second resin composition forming the second resin composition layer is not particularly limited as long as the composition is different from that of the first resin composition, and the second resin composition contains an inorganic filler. The thing containing an inorganic filler and a liquid epoxy resin is more preferable.

  As a 2nd resin composition, content of an inorganic filler when a non-volatile component in a 2nd resin composition is 100 mass% from a viewpoint of obtaining an insulating layer with a low thermal expansion coefficient is 60 mass% or more. It is preferably 70% by mass or more, more preferably 72% by mass or more, 74% by mass or more, or 76% by mass or more. The upper limit of the content of the inorganic filler in the second resin composition is preferably 95% by mass or less, more preferably 90% by mass or less. Examples of the inorganic filler in the second resin composition include the same inorganic filler as described in the section <First resin composition>. When the content of the inorganic filler in the first resin composition is A1 (mass%) and the content of the inorganic filler in the second resin composition is A2 (mass%), A1 and A2 are: It is preferable to satisfy the relationship of A1 <A2, and it is more preferable to satisfy the relationship of A1 + 20 ≦ A2, A1 + 25 ≦ A2, A1 + 30 ≦ A2, A1 + 35 ≦ A2, or A1 + 40 ≦ A2. Further, when the average particle diameter of the inorganic filler in the first resin composition is D1 (μm) and the average particle diameter of the inorganic filler in the second resin composition is D2 (μm), D1 and D2 Preferably satisfies the relationship of D1 ≦ D2, and satisfies the relationship of D1 ≦ 0.9D2, D1 ≦ 0.8D2, D1 ≦ 0.7D2, D1 ≦ 0.6D2, or D1 ≦ 0.5 ≦ D2. Is more preferable. Therefore, the average particle diameter of the inorganic filler (C) in the second resin composition is preferably 0.5 μm or more from the viewpoint of improving embedding properties.

  In one embodiment, the second resin composition includes an epoxy resin and a curing agent together with an inorganic filler. The second resin composition may further contain additives such as a thermoplastic resin, a curing accelerator, a flame retardant, and rubber particles as necessary.

  The epoxy resin, curing agent and additive contained in the second resin composition are the same as the (A) epoxy resin, (B) curing agent and additive described in the <First resin composition> column. Is mentioned.

  The content of the epoxy resin in the second resin composition is preferably 0.1% by mass or more, more preferably 5% by mass or more, from the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability. Preferably it is 10 mass% or more. Although the upper limit of content of an epoxy resin is not specifically limited as long as the effect of this invention is show | played, Preferably it is 30 mass% or less, More preferably, it is 25 mass% or less, More preferably, it is 22 mass% or less. Therefore, the content of the (A) epoxy resin in the second resin composition is preferably 0.1 to 30% by mass, more preferably 5 to 25% by mass, and still more preferably 10 to 22% by mass.

Epoxy resin of the second resin composition is, if it contains solid epoxy resin and a liquid epoxy resin, the ratio of the mass M _S of a solid epoxy resin to the weight M _L of the liquid epoxy resin (M S _{/ M L)} is A range of 1 to 10 is preferred. The M S _/ M _L, With such a range, i) moderate tackiness is brought when used in the form of a resin sheet, ii) sufficient flexibility when used in the form of a resin sheet Is obtained, the handleability is improved, and iii) a cured product having sufficient breaking strength can be obtained. Moreover, in order to reduce melt viscosity, when an inorganic filler is 100 mass parts, it is preferable that 5 mass parts or more of liquid epoxy resins are included.

  In addition, the suitable range of the epoxy equivalent of an epoxy resin and the weight average molecular weight of an epoxy resin in a 2nd resin composition is the same as that of the epoxy resin contained in a 1st resin composition.

  The content of the curing agent in the second resin composition is not particularly limited, but is preferably 0.1% by mass or more, more preferably 1% by mass or more from the viewpoint of obtaining an insulating layer having high peel strength and a low dielectric loss tangent. More preferably, it is 5% by mass or more. Although the upper limit of content of a hardening | curing agent is not specifically limited as long as the effect of this invention is show | played, Preferably it is 20 mass% or less, More preferably, it is 15 mass% or less, More preferably, it is 10 mass% or less. Therefore, content of the hardening | curing agent in 2nd resin composition becomes like this. Preferably it is 0.1-20 mass%, More preferably, it is 1-15 mass%, More preferably, it is 5-10 mass%.

  The amount ratio of the epoxy resin and the curing agent in the second resin composition is a ratio of [total number of epoxy groups of epoxy resin]: [total number of reactive groups of curing agent], which is 1: 0.2. The range of ˜1: 2 is preferable, 1: 0.3 to 1: 1.5 is more preferable, and 1: 0.4 to 1: 1 is more preferable. By making the quantity ratio of an epoxy resin and a hardening | curing agent into such a range, the heat resistance of the hardened | cured material of a 2nd resin composition improves more.

  Although content of the thermoplastic resin in a 2nd resin composition is not specifically limited, Preferably it is 0 mass%-10 mass%, More preferably, it is 0.2 mass%-8 mass%, More preferably, it is 0.5. It is 5 mass%-5 mass%.

  Although content of the hardening accelerator in a 2nd resin composition is not specifically limited, It is preferable to use in 0.001 mass%-3 mass%.

  The content of the flame retardant in the second resin composition is not particularly limited, but is preferably 0.2% by mass to 20% by mass, more preferably 0.5% by mass to 15% by mass, and still more preferably 0.8%. More preferably, 10% by mass to 10% by mass.

  The content of the organic filler in the second resin composition is preferably 0.1% by mass to 20% by mass, more preferably 0.2% by mass to 10% by mass.

  Similar to the first resin composition, the second resin composition may include other additives other than the flame retardant and the organic filler, for example, an organic copper compound, an organic zinc compound, an organic cobalt compound, etc. And an organic filler, a thickener, an antifoaming agent, a leveling agent, an adhesion-imparting agent, and a resin additive such as a coloring agent.

[Resin sheet with support]
Hereinafter, the resin sheet with a support of the present invention will be described.

  The resin sheet with a support of the present invention comprises a support and a resin sheet provided on the support, the first resin composition layer provided on the support side, and the support. Is provided on the opposite side and has a second resin composition layer formed by a second resin composition having a composition different from that of the first resin composition forming the first resin composition layer. The minimum melt viscosity of the resin sheet is 6000 poise or less, and the average linear thermal expansion coefficient between 25 ° C. and 150 ° C. of the cured product layer obtained by curing the resin sheet is 17 ppm / ° C. or less. And

  An example of the resin sheet with a support of the present invention is shown in FIG. In FIG. 2, the resin sheet 10 with a support includes a support 11 and a resin sheet 12 provided on the support 11. In FIG. 2, the resin sheet 12 includes a first resin composition layer 13 provided on the support side and a second resin composition layer 14 provided on the side opposite to the support. As will be described later, in the resin sheet with a support of the present invention, the resin sheet may include an additional resin composition layer between the first resin composition layer and the second resin composition layer. Good.

<Support>
Examples of the support include a film made of a plastic material, a metal foil, and a release paper, and a film made of a plastic material and a metal foil are preferable.

  When a film made of a plastic material is used as the support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”) and polyethylene naphthalate (hereinafter abbreviated as “PEN”). .) Polyester, polycarbonate (hereinafter sometimes abbreviated as “PC”), polymethyl methacrylate (PMMA) and other acrylics, cyclic polyolefin, triacetyl cellulose (TAC), polyether sulfide (PES), polyether Examples include ketones and polyimides. Among these, polyethylene terephthalate and polyethylene naphthalate are preferable, and inexpensive polyethylene terephthalate is particularly preferable.

  When using metal foil as a support body, as metal foil, copper foil, aluminum foil, etc. are mentioned, for example, Copper foil is preferable. As the copper foil, a foil made of a single metal of copper may be used, and a foil made of an alloy of copper and another metal (for example, tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.). It may be used.

  The support may be subjected to mat treatment and corona treatment on the surface to be bonded to the first resin composition layer.

  Further, as the support, a support with a release layer having a release layer on the surface to be bonded to the first resin composition layer may be used. Examples of the release agent used for the release layer of the support with a release layer include one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. . As the support with a release layer, a commercially available product may be used. For example, “SK-1” manufactured by Lintec Corporation, which is a PET film having a release layer mainly composed of an alkyd resin release agent. , “AL-5”, “AL-7”, and the like.

  Although the thickness of a support body is not specifically limited, The range of 5 micrometers-75 micrometers is preferable, and the range of 10 micrometers-60 micrometers is more preferable. In addition, when using a support body with a release layer, it is preferable that the thickness of the whole support body with a release layer is the said range.

<Resin sheet>
The resin sheet has a composition different from the first resin composition layer provided on the support side and the first resin composition provided on the opposite side of the support and forming the first resin composition layer. And a second resin composition layer formed of the second resin composition.

  In the present invention, the minimum melt viscosity of the resin sheet is 6000 poise or less, preferably 5500 poise or less, more preferably 5000 poise or less, from the viewpoint of realizing good embedding of the components inside the cavity when the component built-in circuit board is manufactured. It is. The minimum of the minimum melt viscosity of a resin sheet is not specifically limited, Usually, 500 poise or more, 1000 poise or more etc. can be used.

  Here, the “minimum melt viscosity” of the resin sheet refers to the lowest viscosity exhibited by the resin sheet when the resin of the resin sheet is melted. Specifically, when the resin sheet is heated at a constant temperature increase rate to melt the resin, the initial stage of the melt viscosity decreases as the temperature increases, and thereafter, when the temperature exceeds a certain temperature, the melt viscosity increases as the temperature increases. . “Minimum melt viscosity” refers to the melt viscosity at such a minimum point. The minimum melt viscosity of the resin sheet can be measured by a dynamic viscoelastic method. Specifically, the minimum melt viscosity of the resin sheet can be obtained by performing dynamic viscoelasticity measurement under the conditions of a measurement start temperature of 60 ° C., a temperature increase rate of 5 ° C./min, a frequency of 1 Hz, and a strain of 1 deg. Examples of the dynamic viscoelasticity measuring apparatus include “Rheosol-G3000” manufactured by UBM Co., Ltd.

  The minimum melt viscosity of the first resin composition layer and the second resin composition layer is not particularly limited as long as the minimum melt viscosity of the resin sheet is in an intended range, but from the viewpoint of good component embedding property, film thickness From the viewpoint of improving controllability, it is preferable that the minimum melt viscosity of the second resin composition layer to be disposed on the substrate side is smaller than the minimum melt viscosity of the first resin composition layer. When the minimum melt viscosity of the first resin composition layer is v1 (poise) and the minimum melt viscosity of the second resin composition layer is v2 (poise), v1 and v2 satisfy the relationship of v2 + 500 ≦ v1. Is preferable, and it is more preferable to satisfy the relationship of v2 + 1000 ≦ v1, v2 + 1500 ≦ v1, or v2 + 2000 ≦ v1.

  In the present invention, the average linear thermal expansion coefficient between 25 ° C. and 150 ° C. of the cured product layer obtained by curing the resin sheet is 17 ppm / from the viewpoint of realizing a component built-in circuit board in which the problem of warpage is suppressed. Or less, preferably 16 ppm / ° C. or less, more preferably 15 ppm / ° C. or less. The lower limit of the average linear thermal expansion coefficient is not particularly limited, but can usually be 1 ppm / ° C. or higher, 2 ppm / ° C. or higher, 3 ppm / ° C. or higher, and the like. The average linear thermal expansion coefficient can be measured, for example, by a known method such as thermomechanical analysis. Examples of the thermomechanical analyzer include “Thermo Plus TMA8310” manufactured by Rigaku Corporation. In this invention, the average linear thermal expansion coefficient of a hardened | cured material layer is an average linear thermal expansion coefficient of 25-150 degreeC of a plane direction at the time of performing a thermomechanical analysis by the tension | pulling load method.

  In the resin sheet with a support of the present invention, the thickness of the resin sheet is preferably 3 μm or more, more preferably 5 μm or more. The upper limit of the thickness of the resin sheet is preferably 30 μm or less, more preferably 25 μm or less, from the viewpoint of thinning the insulating layer.

  In the present invention, the thickness of the first resin composition layer made of the first resin composition is preferably 5 μm or less, more preferably 3 μm or less. Although the minimum of the thickness of a 1st resin composition layer is not specifically limited, From a viewpoint of obtaining the insulating layer which exhibits the outstanding peeling strength with respect to a conductor layer after a roughening process, from a viewpoint of the ease of manufacture of the resin sheet with a support body. Usually, it may be 0.05 μm or more, 0.1 μm or more, and the like. By the presence of the first resin composition layer, it is possible to suppress the oozing out of the resin, and the film thickness control ability in the case of the thin film is improved.

  In the present invention, the thickness of the second resin composition layer composed of the second resin composition is not particularly limited, and the thickness of the first resin composition layer and the additional resin composition layer (if present) described later is not limited. What is necessary is just to determine so that the thickness of the resin sheet obtained may become a desired range, considering thickness. In one embodiment, the thickness of the second resin composition layer is preferably 3 μm or more, more preferably 5 μm or more, still more preferably 7 μm or more, 8 μm or more, 9 μm or more, or 10 μm or more. The upper limit of the thickness of the second resin composition layer is preferably 100 μm or less, more preferably 80 μm or less, still more preferably 60 μm or less, 50 μm or less, 40 μm or less, or 30 μm or less. In particular, the melt viscosity tends to be extremely low for improving the embedding property. In this case, the thickness of the second resin composition layer is preferably 25 μm or less in order to prevent the bleeding from occurring. Also, in the case of a thin film, the melt viscosity is less likely to be lowered due to the influence of other resin composition layers, and the embedding property is likely to be lowered. However, since the embedding property can be improved by the configuration of the present invention, it is particularly effective when the thickness is 25 μm or less. It becomes.

  In the present invention, the resin sheet includes first and second resin composition layers between the first resin composition layer (support side) and the second resin composition layer (side opposite the support). A resin composition layer (not shown) having a composition different from that of the resin composition layer may be included. Such an additional resin composition layer may be formed using the same material as the component described in the section <First resin composition>.

  The resin sheet with a support 10 of the present invention may further include a protective film on the surface of the resin sheet 12 that is not joined to the support 11 (that is, the surface opposite to the support). The protective film contributes to the prevention of adhesion and scratches of dust on the surface of the resin sheet 12. As the material for the protective film, the same material as described for the support 11 may be used. Although the thickness of a protective film is not specifically limited, For example, they are 1 micrometer-40 micrometers. When manufacturing a printed wiring board, the resin sheet 10 with a support can be used by removing the protective film.

  The resin sheet with a support of the present invention can realize a good embedding property of the components inside the cavity during the production of the component built-in circuit board, and can realize a component built-in circuit board in which the problem of warpage is suppressed. Therefore, the resin sheet with a support according to the present invention can be used particularly suitably for embedding a component inside the cavity (for embedding the cavity) during the production of the component built-in circuit board. The resin sheet with a support of the present invention can also be used for forming an insulating layer of a printed wiring board (for an insulating layer of a printed wiring board). Since the resin sheet with a support of the present invention can provide an insulating layer on which fine wiring can be formed, in order to form an insulating layer in the production of a printed wiring board by a build-up method (printed wiring board) In order to form a conductor layer by plating (for a build-up insulating layer of a printed wiring board on which a conductor layer is formed by plating), it can be suitably used. .

<Method for producing resin sheet with support>
Hereinafter, an example of a method for producing a resin sheet with a support according to the present invention, that is, an example of a method for producing a resin sheet with a support, in which the resin sheet is composed of a first resin composition layer and a second resin composition layer. explain.
On the support, a first resin composition layer made of the first resin composition and a second resin composition layer made of the second resin composition are formed.

  As a method of forming the first resin composition layer and the second resin composition layer, for example, there is a method of laminating the first resin composition layer and the second resin composition layer so as to be bonded to each other. Can be mentioned. As a method of laminating the first resin composition layer and the second resin composition layer so as to be bonded to each other, for example, the first resin composition is applied to a support, the coating film is dried, After forming the 1 resin composition layer, the 2nd resin composition is apply | coated on the 1st resin composition layer, the coating film is dried and the method of providing a 2nd resin composition layer is mentioned.

  In this method, the first resin composition layer is prepared by preparing a resin varnish obtained by dissolving the first resin composition in an organic solvent, and applying the resin varnish on a support using a die coater or the like. It can be produced by drying the varnish.

  Examples of the organic solvent include ketones such as acetone, methyl ethyl ketone and cyclohexanone, acetates such as ethyl acetate, butyl acetate, cellosolve acetate, propylene glycol monomethyl ether acetate and carbitol acetate, and carbitols such as cellosolve and butyl carbitol. And aromatic hydrocarbons such as toluene and xylene, amide solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone. An organic solvent may be used individually by 1 type, or may use 2 or more types together.

  The resin varnish may be dried by a known drying method such as heating or hot air blowing. Depending on the boiling point of the organic solvent in the resin varnish, for example, when a resin varnish containing 30% by mass to 60% by mass of the organic solvent is used, the support is obtained by drying at 50 ° C. to 150 ° C. for 3 minutes to 10 minutes. A first resin composition layer can be formed thereon.

  In the above method, the second resin composition layer is prepared by preparing a resin varnish in which the second resin composition is dissolved in an organic solvent, and forming the resin varnish on a support using a die coater or the like. It can apply | coat on the resin composition layer of this, and can produce it by drying a resin varnish. The melt viscosity can also be lowered by weakening the drying conditions.

  As the organic solvent used for the preparation of the resin varnish in which the second resin composition is dissolved, the same organic solvent as that used for the preparation of the resin varnish in which the first resin composition is dissolved can be used. The resin varnish in which the composition is dissolved can be dried by the same method as the method for drying the resin varnish in which the first resin composition is dissolved.

  The resin sheet may be formed by a tandem coating method in which two types of resin varnish are sequentially coated on one coating line, in addition to the above coating method. The resin sheet is a method in which the first resin composition is applied on the second resin composition layer, the coating film is dried to provide the first resin composition layer, and the first prepared separately. The resin composition layer and the second resin composition layer can also be formed by a method of laminating them so as to be bonded to each other.

  Furthermore, in the present invention, for example, after the second resin composition layer and the first resin composition layer are formed in order on the protective film, a support is laminated on the first resin composition layer for support. You may produce a resin sheet with a body.

<Manufacturing method of component built-in circuit board>
Next, the manufacturing method of the component built-in circuit board using the resin sheet 10 with a support according to the present invention will be described. The method of manufacturing a component-embedded circuit board according to the present invention includes: (A) a circuit board having first and second main surfaces, and a cavity formed between the first and second main surfaces; A circuit board on which a component is temporarily attached, including a temporary attachment material bonded to the second main surface of the circuit board, and a part temporarily attached by the temporary attachment material inside the cavity of the circuit board, The 1st lamination | stacking which carries out the vacuum lamination | stacking of the resin sheet with a support body of any one of Claims 1-8 so that a said 2nd resin composition layer may join with the 1st main surface of a circuit board. Process,
(B) a heat treatment step of heat treating the circuit board on which the resin sheet with the support is laminated;
(C) A resin sheet with a second support including a second support and a second resin sheet that is bonded to the second support after the tacking material is peeled from the second main surface of the circuit board. A second lamination step of vacuum lamination so that the second resin sheet is bonded to the second main surface of the circuit board;
(D) The step of thermally curing the resin sheet and the second resin sheet of the resin sheet with a support in this order. Prior to the description of each step, “a circuit board on which components are temporarily attached” using the resin sheet with a support 10 of the present invention will be described.

(Circuit board with parts temporarily attached)
A circuit board on which components are temporarily attached (hereinafter also referred to as “component temporary attachment circuit board” or “cavity board”) has first and second main surfaces, and the first and second main surfaces. A circuit board in which a cavity penetrating the circuit board is formed; a tacking material joined to the second main surface of the circuit board; and a component tacked by the tacking material inside the cavity of the circuit board Including.

  The component tack circuit board can be prepared according to any conventionally known procedure when the component built-in circuit board is manufactured. Hereinafter, an example of a procedure for preparing the component tack circuit board will be described with reference to FIGS. 1A to 1D, but is not limited to the following procedure.

  First, a circuit board is prepared (FIG. 1A). “Circuit substrate” refers to a plate-like substrate having first and second main surfaces facing each other and having circuit wiring patterned on one or both of the first and second main surfaces. In FIG. 1A, the end surface of the circuit board 1 is typically shown, and the circuit board 1 includes a substrate 2 and circuit wirings 3 such as via wirings and surface wirings. In the following description, for convenience, the first main surface of the circuit board represents the upper main surface of the illustrated circuit board, and the second main surface of the circuit board represents the lower side of the illustrated circuit board. It represents the main surface.

  Examples of the substrate 2 used for the circuit board 1 include a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, and the like, and a glass epoxy substrate is preferable. Further, when the printed wiring board is manufactured, an inner layer circuit board of an intermediate product on which an insulating layer and / or a conductor layer is to be formed is also included in the “circuit board” in the present invention.

  The thickness of the substrate 2 of the circuit board 1 is preferably thinner from the viewpoint of reducing the thickness of the component-embedded circuit board, preferably less than 400 μm, more preferably 350 μm or less, still more preferably 300 μm or less, and even more preferably 250 μm. Hereinafter, it is particularly preferably 200 μm or less, 180 μm or less, 170 μm or less, 160 μm or less, or 150 μm or less. Although the minimum of the thickness of the board | substrate 2 is not restrict | limited in particular, From a viewpoint of the handleability improvement at the time of conveyance, Preferably it is 50 micrometers or more, More preferably, it is 80 micrometers or more, More preferably, it is 100 micrometers or more.

  The dimensions of the circuit wiring 3 provided on the circuit board 1 may be determined according to desired characteristics. For example, the thickness of the surface wiring is preferably 40 μm or less, more preferably 35 μm or less, even more preferably 30 μm or less, even more preferably 25 μm or less, particularly preferably 20 μm or less, particularly 19 μm, from the viewpoint of reducing the thickness of the component built-in circuit board. Or 18 μm or less. The lower limit of the thickness of the surface wiring is not particularly limited, but is usually 1 μm or more, 3 μm or more, 5 μm or more, and the like.

  Next, a cavity (recess) for housing the component is provided in the circuit board (FIG. 1B). As schematically shown in FIG. 1B, a cavity 2 a that penetrates between the first and second main surfaces of the circuit board can be provided at a predetermined position of the board 2. The cavity 2a can be formed by a known method using, for example, a drill, a laser, plasma, an etching medium, or the like in consideration of the characteristics of the substrate 2.

  Although only one cavity 2a is shown in FIG. 1B, a plurality of cavities 2a can be provided at predetermined intervals. The pitch between the cavities 2a is preferably short from the viewpoint of miniaturization of the component built-in circuit board. The pitch between the cavities 2a is preferably 10 mm or less, more preferably 9 mm or less, even more preferably 8 mm or less, even more preferably 7 mm or less, and particularly preferably 6 mm or less, although it depends on the opening size of the cavity 2a itself. According to the method of the present invention, even when the cavities are provided at such a short pitch, occurrence of substrate warpage can be suppressed. The lower limit of the pitch between the cavities 2a is usually 1 mm or more, 2 mm or more, although depending on the opening size of the cavities 2a itself. Each pitch between the cavities 2a does not need to be the same across the circuit board, and may be different.

  The opening shape of the cavity 2a is not particularly limited, and may be an arbitrary shape such as a rectangle, a circle, a substantially rectangle, or a substantially circle. Moreover, although the opening dimension of the cavity 2a depends on the design of the circuit wiring, for example, when the opening shape of the cavity 2a is rectangular, it is preferably 5 mm × 5 mm or less, more preferably 3 mm × 3 mm or less, or 2 mm × 2 mm or less. . Although the minimum of the said opening dimension is based also on the dimension of the components accommodated, it is 0.5 mm x 0.5 mm or more normally. The opening shape and opening size of the cavity 2a do not need to be the same over the circuit board and may be different.

  Next, a temporary attachment material is laminated on the second main surface of the circuit board provided with the cavity (FIG. 1C). The tacking material is not particularly limited as long as it has an adhesive surface exhibiting sufficient tackiness for tacking a component, and any conventionally known tacking material may be used in the manufacture of the component built-in circuit board. In the embodiment schematically shown in FIG. 1C, the film-like temporary attachment material 4 is laminated so that the adhesive surface of the temporary attachment material 4 is bonded to the second main surface of the circuit board. Thereby, the adhesive surface of the temporary attachment material 4 comes to be exposed through the cavity 2a.

  Examples of the film-like tacking material include UC series (UV tape for wafer dicing) manufactured by Furukawa Electric Co., Ltd.

  Next, a part is temporarily attached to the adhesive surface of the temporary attachment material exposed through the cavity (FIG. 1D). In the embodiment schematically shown in FIG. 1D, the component 5 is temporarily attached to the adhesive surface of the temporary attachment material 4 exposed through the cavity 2a.

  As the component 5, an appropriate electrical component may be selected according to desired characteristics, and examples thereof include a passive component such as a capacitor, an inductor, and a resistor, and an active component such as a semiconductor bare chip. The same part 5 may be used for all the cavities, or a different part 5 may be used for each cavity.

  When manufacturing a component tack circuit board, in addition to the above method, for example, the circuit wiring 3 may be provided after the cavity 2a is formed in the substrate 2, or the tack material 4 may be provided on the second circuit board. The cavity 2a may be formed after being laminated on the main surface.

  A method for producing a component-embedded circuit board using the resin sheet with a support of the present invention will be described. In the following description, the resin sheet with a support of the present invention laminated on the first main surface and the second main surface of the component built-in circuit board is referred to as “first support resin sheet 10” and “ It may be described as “second support-attached resin sheet 20”. As the resin sheet 10 with a 1st support body and the resin sheet 20 with a 2nd support body, the same thing may be used and a different thing may be used.

<(A) First Laminating Step (Lamination of Resin Sheet with First Support)>
First, the resin sheet with a support of the present invention (first resin sheet with a support) is laminated on a circuit board on which components are temporarily attached (first laminating step). Specifically, the resin sheet 10 with the first support is vacuum laminated so that the second resin composition layer 14 is bonded to the first main surface of the circuit board on the circuit board 1 ′ to which the components are temporarily attached. (See FIG. 3A). Here, when the 1st resin sheet 10 with a support body is a structure provided with the protective film which covers the 2nd resin composition layer 14, after peeling a protective film, it laminates | stacks on a circuit board.

  For example, the vacuum lamination of the resin sheet 10 with the first support on the component temporary circuit board 1 ′ is performed by, for example, applying the resin sheet 10 with the support to the component temporary circuit board 1 ′ from the support 11 side under reduced pressure. This can be done by thermocompression bonding. As a member (not shown; hereinafter, also referred to as “heat-bonding member”) for heat-pressing the first support-attached resin sheet 10 to the component temporary bonding circuit board 1 ′, for example, a heated metal plate (SUS). End plate or the like) or metal roll (SUS roll). In addition, the thermocompression-bonding member is not directly pressed on the first support-attached resin sheet 10, but the first support-supporting resin sheet is formed on the unevenness caused by the circuit wiring 3 and the cavity 2 a of the temporary component circuit board 1 ′. It is preferable to press through an elastic material such as heat-resistant rubber so that 10 can follow sufficiently.

  The thermocompression bonding temperature is preferably in the range of 80 ° C. to 160 ° C., more preferably 100 ° C. to 140 ° C., and the thermocompression bonding pressure is preferably 0.098 MPa to 1.77 MPa, more preferably 0.29 MPa to 1. The range is 47 MPa, and the thermocompression bonding time is preferably in the range of 20 seconds to 400 seconds, more preferably in the range of 30 seconds to 300 seconds. The vacuum lamination is preferably performed under a reduced pressure condition of a pressure of 26.7 hPa or less.

  Vacuum lamination can be performed with a commercially available vacuum laminator. Examples of the commercially available vacuum laminator include a vacuum pressure laminator manufactured by Meiki Seisakusho Co., Ltd., a vacuum applicator manufactured by Nichigo Morton, and a two-stage buildup laminator manufactured by Nichigo Morton.

  After the first laminating step, smoothing for smoothing the laminated first adhesive film by pressing a thermocompression bonding member from the first support 11 side under normal pressure (under atmospheric pressure), for example. It is preferable to carry out the conversion step. The pressing conditions for the smoothing step can be the same conditions as the thermocompression bonding conditions for the vacuum lamination.

  The smoothing step can be performed with a commercially available laminator. In addition, you may perform a 1st lamination process and a smoothing process continuously using said commercially available vacuum laminator.

  After the first laminating step, the second resin composition layer 14 is filled in the cavity 2a, and the part 5 temporarily attached in the cavity 2a is embedded in the second resin composition layer 14 ( (See FIG. 3B).

<(B) Heat treatment process>
Next, the circuit board on which the first support-attached resin sheet 10 is laminated is subjected to heat treatment (heat treatment step). The heating temperature in this step is preferably 155 ° C. or lower, more preferably 150 ° C. or lower, further preferably 145 ° C. or lower, and still more preferably 140 ° C. or lower. The lower limit of the heating temperature is preferably 110 ° C. or higher, more preferably 115 ° C. or higher, still more preferably 120 ° C. or higher, and even more preferably 125 ° C. or higher.

  The heating time in the heat treatment step depends on the heating temperature, but is preferably 10 minutes or more, more preferably 15 minutes or more, and further preferably 20 minutes or more. The upper limit of the heating time is not particularly limited, but can usually be 60 minutes or less.

  The heat treatment of the resin sheet 12 in the heat treatment step is preferably performed under atmospheric pressure (normal pressure).

  The heat treatment of the resin sheet 12 in the heat treatment step may be performed with the support 11 attached to the resin sheet 12 or may be performed after the support 11 is peeled and the resin sheet 12 is exposed. In a preferred embodiment, the heat treatment of the resin sheet 12 is performed with the support 11 attached to the resin sheet 12 (first resin composition layer). This is advantageous in terms of preventing foreign matter adhesion and preventing damage to the first resin composition layer.

  When the heat treatment of the resin sheet 12 in the heat treatment step is performed with the support 11 attached, the support 11 has a conductor layer (circuit) on an insulating layer (cured product layer) obtained by curing the resin sheet 12. For example, it may be peeled off between the first heat treatment step and the second laminating step described later, or the second laminating step and the thermosetting step (described later). Or may be peeled after the thermosetting step. In a preferred embodiment, the support 11 is peeled off after the thermosetting step. When a metal foil such as a copper foil is used as the support 11, the support 11 can be peeled off because a conductor layer (circuit wiring) can be provided using the metal foil as described later. You don't have to.

  In a preferred embodiment, the circuit board may be cooled to room temperature (room temperature) between the first lamination step and the heat treatment step.

  In a preferred embodiment, through the heat treatment step, the resin sheet 12 becomes a resin sheet (heat treatment body) 12 '(see FIG. 3C). FIG. 3C shows a mode in which a heat treatment is performed with the support 11 attached to obtain a resin sheet (heat treatment body) 12 ′. In FIG. 3, 13 ′ denotes a first resin composition layer (heat treatment). 14 ′ is a second resin composition layer (heat-treated body).

<(C) Second Laminating Step (Lamination of Resin Sheet with Second Support)>
After the heat treatment step, the tacking material 4 is peeled off from the second main surface of the circuit board to expose the second main surface of the circuit board 2. Then, the second support-attached resin sheet 20 is evacuated so that the second resin composition layer 24 (second resin sheet) is joined to the second main surface (lower side surface in the drawing) of the circuit board 2. Laminate (see FIG. 3D). Here, the 2nd resin sheet with a support body contains the 2nd resin sheet joined to the 2nd support body and this 2nd support body. As the second resin sheet with a support, the resin sheet with a support of the present invention is preferably used. The configurations of the second support and the second resin sheet are the same as those of the above-described support and resin sheet of the present invention. The resin sheet 20 with the second support shown in FIG. 3D is similar to the resin sheet 10 with the first support, in which the second resin sheet 22 is replaced with the first resin composition layer 23 and the second resin composition. It consists of a physical layer 24. In addition, as a resin sheet with a 2nd support body, the resin sheet with another support body (For example, the resin sheet with a support body from which a resin sheet consists of a single resin composition layer, a resin sheet is 1st and 2nd. Although the resin composition layer is included, the desired minimum melt viscosity condition and the average linear thermal expansion coefficient condition in the present invention may be used.

  The peeling of the tacking material 4 may be performed according to a conventionally known method according to the type of the tacking material 4. For example, when a UV tape for wafer dicing such as UC series manufactured by Furukawa Electric Co., Ltd. is used as the tacking material 4, the tacking material 4 can be peeled after UV irradiation of the tacking material 4. The conditions such as the UV irradiation amount can be known conditions that are usually employed in the production of the component built-in circuit board.

  Through the heat treatment process, even when a circuit board with a high cavity density or a thin circuit board is used, the occurrence of substrate warpage can be suppressed, so the process from the heat treatment process to the second lamination process. The second stacking step can be smoothly performed without hindering the substrate transfer. Furthermore, since the resin composition layer is heat-treated under specific conditions, the positional change (displacement) of the component accompanying the vacuum lamination in the second lamination process can also be suppressed, and the component placement accuracy can be improved. An excellent component built-in circuit board can be realized with a high yield.

  The vacuum lamination of the resin sheet 20 with the second support in the second lamination process may employ the same method and conditions as the vacuum lamination of the resin sheet 10 with the first support in the first lamination process.

  In a preferred embodiment, the circuit board may be cooled to room temperature (room temperature) between the heat treatment step and the second lamination step.

  In the second laminating step, the second resin sheet (second resin composition layer 24, first resin composition layer 23) and second support 21 are laminated on the second main surface of the circuit board 2. (See FIG. 3E).

  The second support 21 may be peeled off before the step of providing the conductor layer (circuit wiring) on the insulating layer (cured product layer) obtained by curing the second resin sheet 22, for example, the second support Peeling may be performed between the laminating step and the curing step described later, or may be stripped after the curing step. In a preferred embodiment, the second support 21 is peeled after the curing step. When a metal foil such as a copper foil is used as the second support 21, it is possible to provide a conductor layer (circuit wiring) using such a metal foil, as will be described later. The support 21 may not be peeled off.

<(D) Curing step>
In the curing step, the resin sheet 12 of the resin sheet 10 with the first support and the second resin sheet 22 of the resin sheet 20 with the second support are thermally cured. Thereby, in the 1st main surface of the circuit board 2, 1st resin composition layer (heat-processing body) 13 'forms 1st insulating layer 13 "(hardened | cured material layer), and 2nd resin composition The material layer (heat-treated body) 14 ′ forms the second insulating layer 14 ″ (cured material layer). Further, on the second main surface of the circuit board 2, the first resin composition layer 23 forms the first insulating layer 23 ″ (cured product layer), and the second resin composition layer 24 is the second resin composition layer 24. An insulating layer 24 ″ (cured material layer) is formed (see FIG. 3F).

  The conditions for thermosetting are not particularly limited, and conditions usually employed when forming the insulating layer of the component built-in circuit board may be used.

  Although the thermosetting conditions of the resin sheets 12 and 22 of the first and second resin sheets with support 10 and 20 vary depending on the composition of the resin composition used for each resin composition layer, the curing temperature is 120 ° C to 120 ° C. In the range of 240 ° C. (preferably in the range of 150 ° C. to 210 ° C., more preferably in the range of 170 ° C. to 190 ° C.), the curing time is in the range of 5 minutes to 90 minutes (preferably 10 minutes to 75 minutes, more preferably 15 Minutes to 60 minutes).

  Prior to thermosetting, the first and second resin sheets 12 and 22 may be preheated at a temperature lower than the curing temperature. For example, prior to thermosetting, at a temperature of 50 ° C. or higher and lower than 120 ° C. (preferably 60 ° C. or higher and 110 ° C. or lower, more preferably 70 ° C. or higher and 100 ° C. or lower), the resin sheets 12 and 22 are held for 5 minutes or longer (preferably (5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes). When preheating is performed, such preheating is also included in the curing step.

  The thermosetting of each resin sheet in the curing step is preferably performed under atmospheric pressure (normal pressure).

  In a preferred embodiment, a process of cooling the circuit board to room temperature (room temperature) may be performed between the second lamination process and the curing process.

  In the present invention, the average linear thermal expansion coefficient between 25 ° C. and 150 ° C. of the cured product layer (insulating layers 12 ″, 22 ″) obtained by curing the resin sheet 12 and the second resin sheet 22 is the warpage of the substrate. From the viewpoint of reducing the amount, it is preferably 17 ppm / ° C. or less, more preferably 15 ppm / ° C. or less.

  As mentioned above, although embodiment using a temporary attachment material was described in detail, it may replace with temporary attachment material and may manufacture a circuit board with a built-in component using a resin sheet with a support body. The resin sheet with a support that can be used in place of the temporary attachment material may be the same as the above-described resin sheet with a support, even if the resin sheet with a support of the present invention is another resin with a support. It may be a sheet. When using a resin sheet with a support instead of the temporary attachment material, the temporary attachment material peeling step is unnecessary.

<Other processes>
The method for manufacturing a component-embedded circuit board according to the present invention further includes a step of drilling in the insulating layer (drilling step), a step of roughening the surface of the insulating layer (roughening step), and a conductor on the roughened insulating layer surface. A step of forming a layer (conductor layer forming step) may be further included. These steps may be performed according to various methods known to those skilled in the art, which are used for manufacturing a component built-in circuit board. In addition, when peeling the support bodies 11 and 21 of each resin sheet 10 and 20 with a support body after a hardening process, peeling of the support bodies 11 and 21 is a drilling process and a roughening process between a hardening process and a drilling process. Or between the roughening step and the conductor layer forming step.

  The drilling step is a step of drilling in the insulating layers 12 ", 22" (cured product layer), whereby holes such as via holes can be formed in the insulating layers 12 ", 22". For example, holes can be formed in the insulating layers 12 ″ and 22 ″ using a drill, laser (carbon dioxide laser, YAG laser, etc.), plasma, or the like. In the component built-in circuit board, the insulating layers 12 ″ and 22 ″ are generally conducted by via holes.

  The roughening step is a step of roughening the insulating layers 12 ″ and 22 ″. The procedure and conditions for the roughening treatment are not particularly limited, and known procedures and conditions that are normally used when forming the insulating layers 12 ″ and 22 ″ of the component built-in circuit board can be employed. For example, the roughening treatment of the insulating layers 12 ″ and 22 ″ is performed by performing the swelling treatment with the swelling liquid, the roughening treatment with the oxidizing agent, and the neutralization treatment with the neutralizing solution in this order. Can be processed. Although it does not specifically limit as a swelling liquid, An alkaline solution, surfactant solution, etc. are mentioned, Preferably it is an alkaline solution, As this alkaline solution, a sodium hydroxide solution and a potassium hydroxide solution are more preferable. Examples of commercially available swelling liquids include Swelling Dip Securigans P and Swelling Dip Securigans SBU manufactured by Atotech Japan. The swelling treatment with the swelling liquid is not particularly limited, and can be performed, for example, by immersing the insulating layers 12 ″, 22 ″ in the swelling liquid at 30 to 90 ° C. for 1 minute to 20 minutes. From the viewpoint of suppressing the swelling of the resin in the insulating layers 12 ″ and 22 ″ to an appropriate level, it is preferable to immerse the insulating layers 12 ″ and 22 ″ in a swelling solution at 40 to 80 ° C. for 5 seconds to 15 minutes. Although it does not specifically limit as an oxidizing agent, For example, the alkaline permanganate solution which melt | dissolved potassium permanganate and sodium permanganate in the aqueous solution of sodium hydroxide is mentioned. The roughening treatment with an oxidizing agent such as an alkaline permanganic acid solution is preferably performed by immersing the first and second insulating layers in an oxidizing agent solution heated to 60 to 80 ° C. for 10 to 30 minutes. The concentration of permanganate in the alkaline permanganate solution is preferably 5% by mass to 10% by mass. Examples of commercially available oxidizing agents include alkaline permanganate solutions such as Concentrate Compact P and Dosing Solution Securigans P manufactured by Atotech Japan Co., Ltd. As the neutralizing solution, an acidic aqueous solution is preferable, and as a commercially available product, for example, Reduction Sholysin Securigant P manufactured by Atotech Japan Co., Ltd. may be mentioned. The treatment with the neutralizing solution can be performed by immersing the treated surface subjected to the roughening treatment with the oxidant solution in the neutralizing solution at 30 to 80 ° C. for 5 to 30 minutes. From the viewpoint of workability and the like, a method of immersing an object subjected to roughening treatment with an oxidant solution in a neutralizing solution at 40 to 70 ° C. for 5 to 20 minutes is preferable.

  The conductor forming step is a step of forming a conductor layer (circuit wiring) on the roughened insulating layer surface.

  The conductor material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer is one or more selected from the group consisting of gold, platinum, palladium, silver, copper, aluminum, cobalt, chromium, zinc, nickel, titanium, tungsten, iron, tin and indium. Contains metal. The conductor layer may be a single metal layer or an alloy layer. As the alloy layer, for example, an alloy of two or more metals selected from the above group (for example, nickel-chromium alloy, copper- A layer formed from a nickel alloy and a copper / titanium alloy). Among them, from the viewpoint of versatility of conductor layer formation, cost, ease of patterning, etc., single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or nickel / chromium alloy, copper / An alloy layer of nickel alloy or copper / titanium alloy is preferable, and a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or an alloy layer of nickel / chromium alloy is more preferable, and a single layer of copper is preferable. A metal layer is more preferred.

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

  The thickness of the conductor layer depends on the design of the desired component built-in circuit board, but is generally 3 μm to 35 μm, preferably 5 μm to 30 μm.

  The method for forming the conductor layer is not particularly limited as long as a conductor layer (circuit wiring) having a desired pattern can be formed. In a preferred embodiment, the conductor layer can be formed by plating. For example, the surface of the first and second insulating layers can be plated by a conventionally known technique such as a semi-additive method or a full additive method to form a conductor layer (circuit wiring) having a desired pattern. Hereinafter, an example in which the conductor layer is formed by a semi-additive method will be described.

  First, a plating seed layer is formed on the surfaces of the two insulating layers 12 ″ and 22 ″ by electroless plating. Next, a mask pattern that exposes a part of the plating seed layer corresponding to a desired wiring pattern is formed on the formed plating seed layer. A metal layer is formed by electrolytic plating on the exposed plating seed layer, and then the mask pattern is removed. Thereafter, an unnecessary plating seed layer can be removed by etching or the like to form a conductor layer having a desired pattern.

  Through these steps, a conductor (via wiring) is also formed in the via hole, and the circuit wiring 3 provided on the surfaces of the insulating layers 12 ″ and 22 ″ is electrically connected to the circuit wiring on the circuit board, so that the component built-in circuit A plate 100 is obtained (see FIG. 3G).

  When a metal foil such as a copper foil is used as the support 11 and the second support 21, a conductor layer may be formed by a subtractive method using this metal foil. Alternatively, the conductive layer may be formed by electrolytic plating using a metal foil as a plating seed layer.

  The method for manufacturing a circuit board with a built-in component according to the present invention may also include a step of separating the circuit board with a built-in component.

  In the singulation process, for example, the structure obtained by grinding with a conventionally known dicing apparatus having a rotary blade can be singulated into individual component built-in circuit board units.

[Semiconductor device]
The semiconductor device of the present invention includes a component built-in circuit board manufactured by the above method.

  Examples of such semiconductor devices include various semiconductor devices used for electrical products (for example, computers, mobile phones, digital cameras, and televisions) and vehicles (for example, motorcycles, automobiles, trains, ships, and aircrafts). .

  EXAMPLES The present invention will be specifically described below 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.

<Preparation of resin sheet with support>
Using the resin varnish (resin composition) prepared by the following procedure, resin sheets with supports of Examples and Comparative Examples were produced.

(Preparation of resin varnish 1)
10 parts of naphthylene ether type epoxy resin (DIC Corporation "EXA-7311-G4S", epoxy equivalent 186), bixylenol type epoxy resin (Mitsubishi Chemical Corporation "YX4000HK", epoxy equivalent of about 185) , 20 parts of biphenyl type epoxy resin (“NC3000H” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 288), and phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Corporation), cyclohexanone: methyl ethyl ketone (MEK) with a solid content of 30% by mass 1 part solution) was dissolved by heating in a mixed solvent of 15 parts of solvent naphtha and 5 parts of cyclohexanone with stirring. After cooling to room temperature, 12 parts of a triazine skeleton-containing phenol novolac curing agent (hydroxyl equivalent 125, “LA-7054 manufactured by DIC Corporation, MEK solution with a solid content of 60%) 12 parts, naphthol curing agent ( “SN-485” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., 15 parts of MEK solution having a hydroxyl equivalent weight of 215 and a solid content of 60%, polyvinyl butyral resin (glass transition temperature of 105 ° C., “KS-1” manufactured by Sekisui Chemical Co., Ltd.) ) 10 parts of a 1: 1 mixed solution of ethanol and toluene with a solid content of 15%, 1 part of an amine curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with a solid content of 5% by mass), imidazole-based curing Accelerator ("P200-H50" manufactured by Mitsubishi Chemical Corporation, propylene glycol monomethyl ether solution having a solid content of 50% by mass), rubber particles (Aika Industry) Co., Ltd., AC3816N) 4 parts of MEK 20 parts swollen at room temperature for 12 hours, spherical silica surface-treated with an aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) ) 50 parts of Admatex “SOC2”, average particle size 0.5 μm, carbon amount per unit surface area 0.38 mg / m ² ) were mixed and dispersed uniformly with a high-speed rotating mixer, and then a cartridge filter (manufactured by ROKITECHNO “ The resin varnish 1 was prepared by filtration through SHP050 ").

(Preparation of resin varnish 2)
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) 6 parts, naphthalene type epoxy resin (“HP4032SS” manufactured by DIC Corporation) ”, Epoxy equivalent of about 144), 5 parts of naphthalene type epoxy resin (DIC Corporation“ HP-4710 ”, epoxy equivalent of about 170), xylenol type epoxy resin (Mitsubishi Chemical Corporation“ YX4000HK ”, 6 parts of an epoxy equivalent of 185) and 10 parts of a biphenyl type epoxy resin (“NC3000H” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent of 288) are dissolved by heating in a mixed solvent of 20 parts of solvent naphtha and 10 parts of cyclohexanone with stirring. It was. After cooling to room temperature, 20 parts of a triazine skeleton-containing cresol novolac curing agent (hydroxyl equivalent 151, “LA3018-50P” manufactured by DIC Corporation, 2-methoxypropanol solution with a solid content of 50%), naphthol system Curing agent (“SN-495V” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., MEK solution having a hydroxyl equivalent of 231 and a solid content of 60%), amine curing accelerator (4-dimethylaminopyridine (DMAP), solid content of 5 mass) % MEK solution), flame retardant (“HCA-HQ” manufactured by Sanko Co., Ltd., 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10 -Spherical silica surface-treated with 4 parts of oxide, average particle size of 2 μm, aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) Co. Admatechs Ltd. "SOC4", average particle size 1 [mu] m, mixing the carbon amount 0.31 mg ^/ m 2) 180 parts per unit surface area, after uniformly dispersed in a high-speed rotary mixer, a cartridge filter (ROKITECHNO Ltd. " The resin varnish 2 was prepared by filtration through SHP050 ").

(Preparation of resin varnish 3)
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) 5 parts, bisphenol AF type epoxy resin (manufactured by Mitsubishi Chemical Corporation) "YL7760", 10 parts of epoxy equivalent 238), 5 parts of bixylenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 185), naphthalene type epoxy resin ("ESN475V" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) , Epoxy equivalent 330) 20 parts, and phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Corporation, 5 parts by weight of cyclohexanone: methyl ethyl ketone (MEK) 1: 1 solution) 30 parts, solvent naphtha 25 parts and cyclohexanone 5 Dissolved in a mixed solvent with stirring It was. After cooling to room temperature, 15 parts of a triazine skeleton-containing cresol novolac curing agent (hydroxyl equivalent 151, “LA3018-50P” manufactured by DIC Corporation, 2-methoxypropanol solution with a solid content of 50%), active ester -Based curing agent (DIC Corporation "HPC-8000-65T", active group equivalent of about 223, non-volatile component 65% by weight toluene solution) 10 parts, amine-based curing accelerator (4-dimethylaminopyridine (DMAP), 1 part of MEK solution having a solid content of 5% by mass, flame retardant (“HCA-HQ” manufactured by Sanko Co., Ltd.), 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphafe Surface treatment with 2 parts of nancelen-10-oxide (average particle size 2 μm), aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) The spherical silica (Co. Admatechs Ltd. "SOC2", average particle size 0.5 [mu] m, the carbon amount 0.38 mg ^/ m 2 per unit surface area) 170 parts were mixed, after uniformly dispersed in a high-speed rotary mixer The resin varnish 3 was prepared by filtration through a cartridge filter (“SHP050” manufactured by ROKITECHNO).

(Preparation of resin varnish 4)
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) 6 parts, naphthalene type epoxy resin (“HP4032SS” manufactured by DIC Corporation) ”, Epoxy equivalent of about 144), 5 parts of naphthalene type epoxy resin (DIC Corporation“ HP-4710 ”, epoxy equivalent of about 170), xylenol type epoxy resin (Mitsubishi Chemical Corporation“ YX4000HK ”, 6 parts of epoxy equivalent (185), 10 parts of biphenyl type epoxy resin (“NC3000H” manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 288), and phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Corporation), solid content: 30% by mass 10 parts of cyclohexanone: methyl ethyl ketone (MEK) It was dissolved by heating with stirring in a mixed solvent of Rubentonafusa 20 parts of cyclohexanone 10 parts. After cooling to room temperature, there are 14 parts of a triazine skeleton-containing phenol novolac-based curing agent (hydroxyl equivalent 125, “LA7054 manufactured by DIC Corporation, MEK solution with a solid content of 60%), naphthol-based curing agent (Nippon Steel & Sumitomo Metal). Chemical "SN-495V", hydroxyl equivalent 231 and solid content 60% MEK solution) 10 parts, amine curing accelerator (4-dimethylaminopyridine (DMAP), solid content 5 mass% MEK solution) 1 part, flame retardant (“HCA-HQ” manufactured by Sanko Co., Ltd., 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphaphenanthrene-10-oxide, average particle 2 parts of diameter (2 μm), 2 parts of rubber particles (“AC3816N” manufactured by Aika Kogyo Co., Ltd.) were swollen in 10 parts of MEK at room temperature for 12 hours, Coupling agent (Shin-Etsu Chemical Co., Ltd., "KBM573") surface-treated with spherical silica (Co. Admatechs Co. "SOC4", average particle size 1 [mu] m, the carbon amount 0.31 mg ^{/ m} 2 per unit surface area) 180 parts were mixed and uniformly dispersed with a high-speed rotary mixer, and then filtered with a cartridge filter (“SHP050” manufactured by ROKITECHNO) to prepare a resin varnish 4.

(Preparation of resin varnish 5)
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), 5 parts, bixylenol type epoxy resin (manufactured by Mitsubishi Chemical Corporation) "YX4000HK", 10 parts of an epoxy equivalent of about 185), 20 parts of biphenyl type epoxy resin ("NC3000H" manufactured by Nippon Kayaku Co., Ltd., epoxy equivalent 288), and phenoxy resin ("YX7553BH30" manufactured by Mitsubishi Chemical Corporation), solid 15 parts by weight of a 30 mass% cyclohexanone: methyl ethyl ketone (MEK) 1: 1 solution) was dissolved by heating in a mixed solvent of 15 parts of solvent naphtha and 5 parts of cyclohexanone with stirring. After cooling to room temperature, 10 parts of a triazine skeleton-containing phenol novolac curing agent (hydroxyl equivalent 125, “LA-7054” manufactured by DIC Corporation, MEK solution with a solid content of 60%), naphthol curing agent ( “SN-485” manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., 12 parts of a MEK solution having a hydroxyl equivalent weight of 215 and a solid content of 60%, polyvinyl butyral resin (glass transition temperature of 105 ° C., “KS-1” manufactured by Sekisui Chemical Co., Ltd.) ) 10 parts of a 1: 1 mixed solution of ethanol and toluene with a solid content of 15%, 1 part of an amine curing accelerator (4-dimethylaminopyridine (DMAP), MEK solution with a solid content of 5% by mass), imidazole-based curing Accelerator ("P200-H50" manufactured by Mitsubishi Chemical Corporation, propylene glycol monomethyl ether solution having a solid content of 50% by mass), rubber particles (Aika) Spherical silica surface-treated with aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) After mixing 30 parts of “SOC1” manufactured by Admatechs Co., Ltd., average particle size of 0.25 μm, carbon amount per unit surface area of 0.36 mg / m ² , and uniformly dispersing with a high-speed rotary mixer, a cartridge filter (ROKITETECHNO The resin varnish 5 was prepared by filtration through “SHP030”).

(Preparation of resin varnish 6)
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) 5 parts, bisphenol AF type epoxy resin (manufactured by Mitsubishi Chemical Corporation) "YL7760", 10 parts of epoxy equivalent 238), 5 parts of bixylenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent of about 185), naphthalene type epoxy resin ("ESN475V" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.) , Epoxy equivalent 330) 20 parts, and phenoxy resin (“YX7553BH30” manufactured by Mitsubishi Chemical Corporation, 15 parts by mass of cyclohexanone: methyl ethyl ketone (MEK) 1: 1 solution) 15 parts, solvent naphtha 20 parts, and cyclohexanone 5 Part of the mixed solvent with heating and stirring It was. After cooling to room temperature, 15 parts of a triazine skeleton-containing cresol novolac curing agent (hydroxyl equivalent 151, “LA3018-50P” manufactured by DIC Corporation, 2-methoxypropanol solution with a solid content of 50%), active ester -Based curing agent (DIC Corporation "HPC-8000-65T", active group equivalent about 223, non-volatile component 65 mass% toluene solution) 15 parts, amine-based curing accelerator (4-dimethylaminopyridine (DMAP), 1 part of MEK solution having a solid content of 5% by mass, flame retardant (“HCA-HQ” manufactured by Sanko Co., Ltd.), 10- (2,5-dihydroxyphenyl) -10-hydro-9-oxa-10-phosphafe Surface treatment with 4 parts of nanthrene-10-oxide (average particle size 2 μm), aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) The spherical silica (Co. Admatechs Ltd. "SOC2", average particle size 0.5 [mu] m, the carbon amount 0.38 mg ^/ m 2 per unit surface area) 150 parts were mixed, after uniformly dispersed in a high-speed rotary mixer The resin varnish 6 was prepared by filtration through a cartridge filter (“SHP050” manufactured by ROKITECHNO).

  Table 1 shows the materials used for the production of each resin varnish and the blending amount (mass part of non-volatile content).

(Example 1: Production of resin sheet 1 with support)
As a support, a PET film (“Lumirror T6AM” manufactured by Toray Industries, Inc.) having a release treatment with an alkyd resin release agent (“AL-5” manufactured by Lintec Corporation), a thickness of 38 μm, a softening point of 130 ° C., “release” Type PET ").
By uniformly applying the resin varnish 1 on the release PET with a die coater so that the thickness of the first resin composition layer after drying is 3 μm, and drying at 80 ° C. to 160 ° C. for 5 minutes, A first resin composition layer was obtained on the release PET. Next, the resin varnish 2 is applied on the first resin composition layer so that the thickness combined with the first resin composition layer after drying is 25 μm, and is adjusted to 70 ° C. to 110 ° C. (average 95 ° C.). And dried for 4.5 minutes to form two resin composition layers (resin sheets). Next, a polypropylene film (Oji F-Tex Co., Ltd.) is used as a protective film on the surface of the resin sheet that is not bonded to the support (that is, the surface of the second resin composition layer that is not bonded to the first resin composition layer). ) “Alphan MA-430”, thickness 20 μm) was laminated so as to be bonded to the second resin composition layer. Thereby, the resin sheet 1 with a support body which consists of a support body, the 1st resin composition layer (resin varnish 1 origin), the 2nd resin composition layer (resin varnish 2 origin), and the order of a protective film was obtained. . In order to measure the melt viscosity of the second resin composition layer alone, the resin varnish 2 is uniformly applied on the release PET so that the thickness of the resin composition layer after drying is 22 μm using a die coater. What applied and dried for 4.5 minutes at 70 to 110 degreeC (average 95 degreeC) was also produced. In this example, resin varnish 1 was used as the first resin composition, and resin varnish 2 was used as the second resin composition.

(Example 2: Production of resin sheet 2 with support)
A resin sheet 2 with a support was produced in the same manner as in Example 1 except that the tandem coating method was used instead of the two coatings. Specifically, the resin varnish 1 is applied to a thickness of 3 μm after drying using a die coater, preliminarily dried at 130 ° C. for 0.8 minutes, and then resin is applied onto the resin varnish 1 using a die coater. The varnish 2 was applied so that the thickness combined with the first resin composition layer after drying was 25 μm and dried at 80 ° C. to 110 ° C. (average 100 ° C.) for 4 minutes. Similarly, a resin sheet 2 with a support was obtained. In order to measure the melt viscosity of each resin composition layer alone, the resin varnish 1 was applied on the release PET so that the resin varnish 1 had a thickness of 3 μm after drying, and preliminarily dried at 130 ° C. for 0.8 minutes. Furthermore, the resin varnish 2 was applied to a thickness of 22 μm after drying on 80 ° C. to 110 ° C. (average 100 ° C.) dried for 4 minutes and release PET, and 80 ° C. to 110 ° C. ( What was dried for 4 minutes at an average of 100 ° C. was also produced.

(Example 3: Production of resin sheet 3 with support)
In Example 1, except that the resin varnish 3 was used in place of the resin varnish 2, a resin sheet 3 with a support was obtained in the same manner as in Example 1. In this example, the resin varnish 1 was used as the first resin composition, and the resin varnish 3 was used as the second resin composition.

(Example 4: Production of resin sheet 4 with support)
The resin varnish 5 is uniformly applied with a die coater so that the thickness of the first resin composition layer after drying is 3 μm on the release PET, and dried at 75 to 150 ° C. for 2.5 minutes. Thus, a first resin composition layer was obtained on the release PET. Next, the resin varnish 4 is applied onto the first resin composition layer so that the thickness combined with the first resin composition layer after drying is 25 μm, and is adjusted to 70 ° C. to 110 ° C. (average 95 ° C.). A resin sheet 4 with a support was obtained in the same manner as in Example 1 except that it was dried for 4.5 minutes to form two resin composition layers. In this example, the resin varnish 5 was used as the first resin composition, and the resin varnish 4 was used as the second resin composition.

(Comparative Example 1: Production of resin sheet 5 with support)
In Example 1, a resin sheet 5 with a support was obtained in the same manner as in Example 1 except that the resin varnish 4 was used instead of the resin varnish 2.

(Comparative Example 2: Production of resin sheet 6 with support)
In Example 1, except that the resin varnish 6 was used in place of the resin varnish 2, a resin sheet 6 with a support was obtained in the same manner as in Example 1.

(Measurement of minimum melt viscosity)
(1) Measurement of minimum melt viscosity of first and second resin composition layer (single layer) First or second resin composition of each example on release PET under the same condition as each example and each comparative example Only the resin composition layer of the sample in which the material layer was applied as a single layer was peeled off and compressed with a mold to prepare measurement pellets (diameter 18 mm, 1.2 to 1.3 g).
Using pellets for measurement, using a dynamic viscoelasticity measuring device (“Rheosol-G3000” manufactured by UBM Co., Ltd.), using a parallel plate having a diameter of 18 mm for 1 g of the sample resin composition layer, The temperature was raised from a starting temperature of 60 ° C. to 200 ° C. at a rate of temperature increase of 5 ° C./min. The melt viscosity was calculated and shown in Table 2.

(2) Measurement of minimum melt viscosity of resin sheet (layer consisting of first and second resin composition layers: two layers) Each of the two resin sheets with a support prepared in each Example and each Comparative Example was used. a) One sheet peels the release PET so that two resin composition layers remain on the polypropylene film surface (second resin composition layer side), and (b) the other sheet peels the release PET surface (first The polypropylene film was peeled off so that two resin composition layers remained on the one resin composition layer side). Next, the film obtained by bonding the surfaces of the resin composition layers (a) and (b) is cut, and the configuration of the first resin composition layer / second resin composition layer is maintained. Then, a pellet for measurement (diameter 18 mm, 1.2 g to 1.3 g) was produced by compressing with a mold. Using this, using a dynamic viscoelasticity measuring apparatus ("Rheosol-G3000" manufactured by UBM Co., Ltd.) and using a parallel plate with a diameter of 18 mm for a sample resin composition 1 g, a starting temperature of 60 The dynamic viscoelasticity was measured under the measurement conditions of a measurement temperature interval of 2.5 ° C., a vibration frequency of 1 Hz, and a strain of 1 deg. poise) was calculated and shown in Table 2.

(Measurement of average linear thermal expansion coefficient of cured product of resin sheet with support)
The untreated surface of the release PET film (Lintec Co., Ltd. “501010”, thickness 38 μm, 240 mm square) is a glass cloth base epoxy resin double-sided copper-clad laminate (Matsushita Electric Works, Ltd. “R5715ES”, thickness 0. 7 mm, 255 mm square) was placed on a glass cloth base epoxy resin double-sided copper-clad laminate, and the four sides of the release PET film were fixed with polyimide adhesive tape (width 10 mm).

  Each resin sheet with a support (200 mm square) produced in Examples and Comparative Examples is prepared using a batch-type vacuum pressurization laminator (Nichigo-Morton Co., Ltd., 2-stage buildup laminator CVP700) as a second resin composition. Lamination was performed at the center so that the physical layer was in contact with the release surface of the release PET film. The laminating process was carried out by reducing the pressure for 30 seconds to a pressure of 13 hPa or less and then pressing the film at 100 ° C. and a pressure of 0.74 MPa for 30 seconds.

  Next, the film was thermally cured at 100 ° C. for 30 minutes after being placed in an oven at 100 ° C. and then transferred to an oven at 175 ° C. under a temperature condition of 175 ° C. for 30 minutes. Thereafter, the substrate is taken out in a room temperature atmosphere, and the release PET (support) is peeled off from the resin sheet with a support. Then, the resin sheet (first and second resin composition layers) is further cured at 200 ° C. for 90 minutes. ) Was heat cured.

  After thermosetting, the polyimide adhesive tape was peeled off, and the resin sheet was removed from the glass cloth base epoxy resin double-sided copper-clad laminate. Further, the release PET film (“501010” manufactured by Lintec Corporation) on which the resin sheet was laminated was peeled off to obtain a sheet-like cured product. The obtained cured product was cut into a test piece having a width of 5 mm and a length of 15 mm, and thermomechanical analysis was performed by a tensile load method using a thermomechanical analyzer (“Thermo Plus TMA8310” manufactured by Rigaku Corporation). It was. Specifically, after the test piece was mounted on the thermomechanical analyzer, the test piece was measured twice continuously under the measurement conditions of a load of 1 g and a heating rate of 5 ° C./min. The average linear thermal expansion coefficient (ppm / ° C.) in the plane direction in the range from 30 ° C. to 150 ° C. was calculated and shown in Table 2.

<Evaluation test>
1. Evaluation of component embeddability Using the resin sheet with a support prepared in Examples and Comparative Examples, a component provisional circuit board was produced according to the following procedure, and component embeddability was evaluated.

(1) Preparation of component temporary mounting circuit board (cavity board) Glass cloth base BT resin double-sided copper clad laminate (copper foil thickness 18 μm, board thickness 0.15 mm, “HL832NSF LCA” manufactured by Mitsubishi Gas Chemical Co., Ltd.) Cavities of 0.7 × 1.1 mm were formed at a pitch of 3 mm on the entire surface of 255 * 340 mm size. Next, both sides are etched by 1 μm with a micro-etching agent (“CZ8100” manufactured by Mec Co., Ltd.) to roughen the copper surface, and further subjected to rust prevention (“CL8300” manufactured by Mec Co., Ltd.). Dry at 30 ° C. for 30 minutes.

(2) Fabrication of component temporary circuit board A batch of 25um thick polyimide film with adhesive (polyimide 38um thickness, manufactured by Arisawa Manufacturing Co., Ltd., "PFDKE-1525TT") is batched on one side of the board obtained in (1). Using a pressure-type vacuum press laminator (Nichigo Morton Co., Ltd. 2-stage build-up laminator “CVP700”), the pressure-sensitive adhesive was disposed so as to be bonded to the substrate and laminated on one side. Lamination was performed by reducing the pressure for 30 seconds to a pressure of 13 hPa or less and then pressing the film at 80 ° C. and a pressure of 0.74 MPa for 30 seconds. Next, a multilayer ceramic capacitor component (1005 = 1 * 0.5 mm size, thickness 0.14 mm) was temporarily attached to the cavity one by one to produce a component temporary circuit board (cavity substrate) (see FIG. 1D). .

(3) Evaluation test of component embedding from a resin sheet with a support produced in Examples and Comparative Examples using a batch type vacuum pressure laminator (Nichigo-Morton Co., Ltd. 2-stage buildup laminator “CVP700”) The second resin composition layer exposed by peeling off the protective film, and the surface of the component temporary circuit board (cavity substrate) prepared in (2) on the side opposite to the adhesive film mounting surface, Lamination was performed (see FIG. 3A). Lamination was performed by reducing the pressure for 30 seconds to a pressure of 13 hPa or less and then pressing the film at 100 ° C. and a pressure of 0.74 MPa for 30 seconds. Next, the laminated resin sheets were smoothed by hot pressing at 100 ° C. and a pressure of 0.5 MPa for 60 seconds under atmospheric pressure. Evaluation board | substrate A was produced by peeling the polyimide film with an adhesive from the component provisional circuit board cooled to room temperature (refer FIG. 3B). From the surface of the evaluation substrate A from which the polyimide film was peeled, the resin flow in the cavity was observed with an optical microscope (150 times) (10 cavities), and component embedding was evaluated according to the following criteria. The results are shown in Table 2. .
○: In all the cavities, the outer peripheral portion of the multilayer ceramic capacitor component is covered with resin.
X: Some of the cavities have voids or are not embedded with resin in the outer peripheral portion of the multilayer ceramic capacitor component.
It was judged.

2. Evaluation of warpage (1) Curing of resin sheet The evaluation substrate A produced in (3) was subjected to a heat treatment for 30 minutes after being placed in an oven at 100 ° C. under a temperature condition of 100 ° C., cooled to room temperature, and then the same as the surface from which the polyimide film with adhesive was peeled off. 1. Adhesive sheet Bonding was performed under the same conditions as in (3) (see FIGS. 3D and 3E). Then, after being put in an oven at 100 ° C. for 30 minutes after being put into an oven at 100 ° C., and then transferred to an oven at 175 ° C. under a temperature condition of 175 ° C. for 30 minutes, thermosetting is performed, and insulating layers are formed on both sides of the substrate. Formed (see FIG. 3F). Thereafter, the substrate having the insulating layer formed on both sides is taken out in a room temperature atmosphere, the release PET on both sides is peeled off, and the resin sheet is thermally cured at 200 ° C. under a curing condition for 90 minutes after being placed in an oven at 200 ° C. As a result, a component built-in circuit board was produced and used as an evaluation board B (see FIG. 3G).

(2) Evaluation test of warpage amount After cutting the evaluation board B into 45 mm square pieces (n = 5), a reflow apparatus (“HAS-” manufactured by Nippon Antom Co., Ltd.) that reproduces the solder reflow temperature at a peak temperature of 260 ° C. 6116 ") (reflow temperature profile conforms to IPC / JEDEC J-STD-020C). Then, using a shadow moire device (“Thermoire AXP” manufactured by Akrometrix), the bottom surface of the substrate is heated with a reflow temperature profile conforming to IPC / JEDEC J-STD-020C (peak temperature 260 ° C.), and 10 mm in the center of the substrate. The corner displacement (μm) was measured and the results are shown in Table 2.

  In Table 2, with the evaluation results, in the resin sheets with supports of Examples and Comparative Examples, the thicknesses of the first and second resin composition layers and the types of resin varnishes used for forming each resin composition layer, The coating method of each resin composition, the minimum melt viscosity of the first and second resin composition layers (single layer), the minimum melt viscosity of the resin sheet (two layers), and the average thermal expansion coefficient of the cured product layer are also shown. Indicated.

DESCRIPTION OF SYMBOLS 1 ... Circuit board 2 ... Board | substrate 2a ... Cavity 3 ... Circuit wiring 4 ... Temporary material 5 ... Parts 10 ... Resin sheet | seat with 1st support body 11 ... Support body 12 ... Resin sheet 12 '... Resin sheet (heat-processing body)
12 "... Insulating layer (hardened material layer)
13 ... 1st resin composition layer 13 '... 1st resin composition layer (heat-processing body)
13 "... 1st insulating layer (cured material layer)
14 ... 2nd resin composition layer 14 '... 2nd resin composition layer (heat-processing body)
14 "... 2nd insulating layer (hardened | cured material layer)
20 ... Resin sheet with second support 21 ... Second support 22 ... Second resin sheet 22 "... Insulating layer (cured material layer)
23 ... 1st resin composition layer 23 "... 1st insulating layer (cured material layer)
24 ... 2nd resin composition layer 24 "... 2nd insulating layer (cured material layer)
100 ... Circuit board with built-in components

Claims (12)

A resin sheet with a support comprising a support and a resin sheet provided on the support,
The resin sheet includes a first resin composition layer provided on the support side,
2nd resin formed by the 2nd curable resin composition of the composition different from the 1st curable resin composition which is provided in the opposite side to a support body and forms the 1st resin composition layer A composition layer,
The minimum melt viscosity of the resin sheet is less 6000Poise, average linear thermal expansion coefficient of between 25 ° C. of the cured layer formed by curing the resin sheet to 0.99 ° C. is 17 ppm / ° C. Ri der less,
A resin sheet with a support , wherein the resin sheet has a thickness of 30 μm or less . The resin sheet with a support according to claim 1 , wherein the thickness of the second resin composition layer is 25 μm or less. The second curable resin composition includes an inorganic filler,
The resin sheet with a support according to claim 1 or 2 , wherein the content of the inorganic filler is 70% by mass or more when the nonvolatile component in the second curable resin composition is 100% by mass. The resin sheet with a support according to any one of claims 1 to 3 , wherein the minimum melt viscosity of the second resin composition layer is lower than the minimum melt viscosity of the first resin composition layer. The resin sheet with a support according to any one of claims 1 to 4 , which is used for embedding a cavity. The first curable resin composition and the second curable resin composition each include an inorganic filler,
When the average particle diameter of the inorganic filler in the first curable resin composition is D1 (μm) and the average particle diameter of the inorganic filler in the second curable resin composition is D2 (μm), D1 And D2 satisfy | fills the relationship of D1 <= D2, The resin sheet with a support body of any one of Claims 1-5 . The average particle diameter D1 (μm) of the inorganic filler in the first curable resin composition and the average particle diameter D2 (μm) of the inorganic filler in the second curable resin composition are D1 ≦ 0.5. The resin sheet with a support according to claim 6 satisfying a relation of ≦ D2. The resin sheet with a support according to any one of claims 1 to 7 , wherein the second curable resin composition contains an inorganic filler and a liquid epoxy resin. The resin sheet with a support according to claim 8 , comprising 5 parts by mass or more of a liquid epoxy resin when the inorganic filler is 100 parts by mass. (A) A circuit board having first and second main surfaces and having a cavity penetrating between the first and second main surfaces, and a second main surface of the circuit board joined to each other a tacking material are, the inside of the cavity of the circuit board and a tack tack has been part of a material, component a tacking circuit boards, according to any one of claims 1-9 A first laminating step of vacuum laminating the resin sheet with a support so that the second resin composition layer is bonded to the first main surface of the circuit board;
(B) a heat treatment step of heat treating the circuit board on which the resin sheet with the support is laminated;
(C) A resin sheet with a second support including a second support and a second resin sheet that is bonded to the second support after the tacking material is peeled from the second main surface of the circuit board. A second lamination step of vacuum lamination so that the second resin sheet is bonded to the second main surface of the circuit board;
(D) The manufacturing method of the circuit board with a built-in component which includes the process of thermosetting the resin sheet of the resin sheet with a support and the second resin sheet in this order. The method for manufacturing a component built-in circuit board according to claim 10 , wherein the thickness of the circuit board is 100 μm or more. The method for producing a component-embedded circuit board according to claim 10 or 11 , wherein the second resin sheet with a support is the resin sheet with a support according to any one of claims 1 to 9 .

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