JP6318690B2 - Manufacturing method of component built-in circuit board and semiconductor device - Google Patents

Description

  The present invention relates to 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 and miniaturization of printed wiring boards used in such small high-performance electronic devices.

  Components such as a bare chip, a chip capacitor, and a chip inductor 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, and it is possible to meet the recent demand for higher functionality and downsizing of the printed wiring board. It was difficult.

  In order to cope with such a problem, a component built-in circuit board has been proposed as a printed wiring board that can be miniaturized while increasing the amount of the component mounted by incorporating the component in the inner layer circuit board (Patent Literature). 1).

JP 2011-216636 A

  The component built-in circuit board can be manufactured as follows using, for example, an inner layer circuit board in which a cavity for housing a component is formed. (I) A temporary attachment material for temporarily attaching components is laminated on one main surface of the inner layer circuit board on which the cavity is formed. (Ii) A part is temporarily attached to the adhesive surface of the temporary attachment material exposed through the cavity. (Iii) A thermosetting resin composition layer is provided on the other main surface of the inner layer circuit board in which components are temporarily attached in the cavity, and the insulating layer is formed by thermosetting. (Iv) After peeling off the tacking material, a thermosetting resin composition layer is provided on one main surface of the exposed inner layer circuit board and thermally cured to form an insulating layer. Thereafter, (v) a circuit board with a built-in component is formed by providing circuit wiring.

  In order to achieve further miniaturization and weight reduction of electronic devices, it is desired to reduce the size and thickness of the component built-in circuit board itself. However, when using an internal circuit board with a high cavity density or an internal circuit board with a small thickness to achieve miniaturization and thinning of the component built-in circuit board itself, it is insulated on one main surface of the internal circuit board. At the stage of forming the layer (after (iii) above), a phenomenon that the inner layer circuit board curls (hereinafter also referred to as “substrate warpage”) may occur with the surface on which the insulating layer is provided as the inner peripheral side. The present inventors have found out. When the substrate warps, the substrate conveyance is hindered and the manufacturing efficiency (yield) is reduced.

  In addition, the miniaturization of built-in components and the miniaturization of circuits are progressing, and the requirements for the placement accuracy of components in the cavity of the inner circuit board are increasing.

  It is an object of the present invention to provide a method of manufacturing a circuit board with a built-in component that can suppress substrate warpage and can suppress the positional change (displacement) of the component in the cavity and realize excellent component placement accuracy. To do.

  As a result of earnestly examining the above problems, the present inventors have laminated the thermosetting resin composition layer on one main surface of the inner layer circuit board, and then the thermosetting resin composition layer under specific conditions. It has been found that the above problems can be solved by heat treatment, and the present invention has been completed.

That is, the present invention includes the following contents.
[1] A method for manufacturing a component-embedded circuit board including the following steps (A), (B), (C) and (D) in this order.
(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 first support body and a first support body on a circuit board on which a part is temporarily attached, the part including a temporary attachment material and a part temporarily attached with the temporary attachment material inside a cavity of the circuit board The first adhesive film including the first thermosetting resin composition layer to be bonded to the substrate is vacuum laminated so that the first thermosetting resin composition layer is bonded to the first main surface of the circuit board. (B) heat-treating the first thermosetting resin composition layer in the following step (C) to suppress positional deviation of the component, and the heat treatment suppresses the occurrence of substrate warpage. (C) After removing the tacking material from the second main surface of the circuit board, the second step A second adhesive film including a support and a second thermosetting resin composition layer bonded to the second support is used as the second thermosetting resin composition layer. (D) The process of thermosetting the first and second thermosetting resin composition layers [2] The first thermosetting resin composition in the first adhesive film The method for producing a circuit board with a built-in component according to [1], wherein the minimum melt viscosity of the layer is 100 to 10,000 poise.
[3] In the step (B), the first thermosetting resin composition layer is heat-treated so that its minimum melt viscosity is 15,000 to 200,000 poises. Circuit board manufacturing method.
[4] The method for manufacturing a component built-in circuit board according to any one of [1] to [3], wherein in the step (B), heat treatment is performed with the first support attached.
[5] The method for manufacturing a component-embedded circuit board according to any one of [1] to [4], wherein the thickness of the circuit board is 50 to 350 μm.
[6] The method for manufacturing a component-embedded circuit board according to any one of [1] to [5], wherein a pitch between cavities is 1 to 10 mm.
[7] The method for manufacturing a circuit board with a built-in component according to any one of [1] to [6], wherein the second thermosetting resin composition layer is thinner than the first thermosetting resin composition layer.
[8] When a test piece having a planar dimension of L (mm) × W (mm) (where L ≧ W and L is 550 mm or less) is obtained from the substrate obtained in the step (B). The method for producing a circuit board with a built-in component according to any one of [1] to [7], wherein the warp of the test piece is 0.1 L (mm) or less.
[9] A semiconductor device including a component built-in circuit board manufactured by the method according to any one of [1] to [8].

  According to the present invention, it is possible to provide a method for manufacturing a circuit board with a built-in component that can suppress substrate warpage and can suppress the positional change (displacement) of the component in the cavity and realize excellent component placement accuracy. it can.

FIG. 1A is a schematic diagram (1) 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 built-in circuit board 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 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 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 attached, which is used in the method of manufacturing a component-embedded circuit board according to the present invention. FIG. 2 is a schematic view showing an embodiment of the first adhesive film used in the method for producing a component-embedded circuit board of the present invention. FIG. 3A is a schematic diagram (1) for explaining the method of manufacturing the component built-in circuit board according to the embodiment of the present invention. FIG. 3B is a schematic diagram (2) for explaining the method of manufacturing the component built-in circuit board according to the embodiment of the present invention. FIG. 3C is a schematic diagram (3) for explaining the method of manufacturing the component built-in circuit board according to the embodiment of the present invention. Drawing 3D is a mimetic diagram (4) for explaining a manufacturing method of a component built-in circuit board in one embodiment of the present invention. FIG. 3E is a schematic diagram (5) for explaining the method of manufacturing the component built-in circuit board according to the embodiment of the present invention. FIG. 3F is a schematic diagram (6) for explaining the method of manufacturing the component built-in circuit board according to the embodiment of the present invention. FIG. 3G is a schematic diagram (7) for explaining the method for manufacturing the component built-in circuit board according to the embodiment of the present invention. FIG. 4 is a schematic diagram for explaining a substrate warpage evaluation method.

  Before describing in detail the manufacturing method of the component built-in circuit board of the present invention, the “circuit board on which components are temporarily attached” and the “adhesive film” used in the manufacturing method of the present invention will be described.

<Circuit board with parts temporarily attached>
A circuit board on which a component used in the manufacturing method of the present invention is temporarily attached (hereinafter also referred to as “component temporary attachment circuit board”) has first and second main surfaces, and the first and second main surfaces. A circuit board in which a cavity penetrating between the main surfaces of the circuit board is formed, a temporary attachment material bonded to the second main surface of the circuit board, and temporary attachment with the temporary attachment material inside the cavity of the circuit board Parts.

  Such a component tack circuit board may be prepared according to any conventionally known procedure when manufacturing the component built-in circuit board. Hereinafter, an example of a procedure for preparing a component temporary circuit board will be described with reference to FIGS. 1A to 1D.

  First, a circuit board is prepared (FIG. 1A). In the present invention, the “circuit board” is a plate-like shape having first and second main surfaces facing each other and circuit wiring patterned on one or both of the first and second main surfaces. A substrate. FIG. 1A schematically shows an end face of the circuit board 1. 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. It is 250 μm or less, particularly preferably 200 μm or less, 180 μm or less, 170 μm or less, 160 μm or less, or 150 μm or less. According to the method of the present invention, even when a circuit board having such a thin substrate is used, the occurrence of substrate warpage can be suppressed. 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.

  The thermal expansion coefficient of the substrate 2 of the circuit board 1 is preferably 15 ppm / ° C. or less, more preferably 13 ppm / ° C. or less, and still more preferably 11 ppm / ° C. or less from the viewpoint of suppressing the occurrence of circuit distortion and cracks. The lower limit of the thermal expansion coefficient of the substrate 2 depends on the composition of the resin composition used for forming the insulating layer, but is preferably −2 ppm / ° C. or higher, more preferably 0 ppm / ° C. or higher, and still more preferably 4 ppm / ° C. It is above ℃. In this invention, the thermal expansion coefficient of a board | substrate is a linear thermal expansion coefficient of 25-150 degreeC of the plane direction obtained by carrying out the thermomechanical analysis (TMA) by the tension load method. Examples of the thermomechanical analyzer that can be used for measuring the linear thermal expansion coefficient of the substrate include “Thermo Plus TMA8310” manufactured by Rigaku Corporation and “TMA-SS6100” manufactured by Seiko Instruments Inc.

  The glass transition temperature (Tg) of the substrate 2 of the circuit board 1 is preferably 170 ° C. or higher, more preferably 180 ° C. or higher, from the viewpoint of mechanical strength of the component built-in circuit board. Although the upper limit of Tg of the board | substrate 2 is not specifically limited, Usually, it is 300 degrees C or less. The Tg of the substrate can be measured by thermomechanical analysis using a tensile load method. The same thermomechanical analyzer as described above can be used.

  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, from the viewpoint of thinning the component built-in circuit board. 19 μm or less, 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.

  Second, a cavity for housing the components 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, and more preferably 3 mm × 3 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.

  Third, a temporary attachment material is laminated on the second main surface of the circuit board (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.

  Fourth, 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.

  The example of the procedure for preparing the component temporary circuit board has been described above with reference to FIGS. 1A to 1D. However, the procedure is not limited to the above as long as the component temporary circuit board is obtained. For example, the circuit wiring 3 may be provided after the cavity 2 a is formed in the substrate 2. Alternatively, the cavity 2a may be formed after the tacking material 4 is laminated on the second main surface of the circuit board. Many variations of the procedure for preparing the component tack circuit board are conceivable. A mode in which a component built-in circuit board is manufactured using a component temporary circuit board prepared according to such a modification is also within the scope of the present invention.

<Adhesive film>
In the manufacturing method of the present invention, the first adhesive film and the second adhesive film are used.

(First adhesive film)
In FIG. 2, the end surface of a 1st adhesive film is shown typically. The first adhesive film 10 includes a first support 11 and a first thermosetting resin composition layer 12 that is bonded to the first support.

  Examples of the first 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 first support, examples of the plastic material include polyethylene terephthalate (hereinafter sometimes abbreviated as “PET”) and polyethylene naphthalate (hereinafter abbreviated as “PEN”). Such as polyester, polycarbonate (hereinafter sometimes abbreviated as “PC”), acrylic such as polymethyl methacrylate (PMMA), cyclic polyolefin, triacetyl cellulose (TAC), and polyether sulfide (PES). , Polyether ketone, polyimide and the like. Among these, polyethylene terephthalate and polyethylene naphthalate are preferable, and inexpensive polyethylene terephthalate is particularly preferable.

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

  The first support may be subjected to a mat treatment or a corona treatment on a surface to be bonded to a first thermosetting resin composition layer described later.

  Moreover, as the first support, a support with a release layer having a release layer on the surface to be bonded to the first thermosetting resin composition layer described later 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 1st 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.

  The resin composition used for the first thermosetting resin composition layer is not particularly limited as long as the cured product has sufficient hardness and insulation. Resin used for the first thermosetting resin composition layer from the viewpoint of reducing the thermal expansion coefficient of the obtained insulating layer and preventing the occurrence of cracks and circuit distortion due to the difference in thermal expansion between the insulating layer and the conductor layer The composition preferably includes an inorganic filler.

The content of the inorganic filler in the resin composition is preferably 30% by mass or more, more preferably 40% by mass or more, still more preferably 50% by mass or more, from the viewpoint of reducing the thermal expansion coefficient of the obtained insulating layer. Even more preferably, it is 60% by mass or more, particularly preferably 62% by mass or more, 64% by mass or more, or 66% by mass or more. The upper limit of the content of the inorganic filler in the resin composition is preferably 90% by mass or less, more preferably 85% by mass or less, from the viewpoint of mechanical strength of the obtained insulating layer.
In addition, in this invention, content of each component in a resin composition is a value when the sum total of the non-volatile component in a resin composition is 100 mass%.

  Examples of inorganic fillers include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, talc, clay, mica powder, aluminum hydroxide, magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, and nitride. Boron, aluminum nitride, manganese nitride, aluminum borate, barium titanate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, barium zirconate, calcium zirconate, zirconium phosphate, and phosphoric acid Examples thereof include zirconium tungstate. Among these, silica such as amorphous silica, fused silica, crystalline silica, synthetic silica, and hollow silica is particularly suitable. 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 spherical fused silica include “SOC2” and “SOC1” manufactured by Admatechs.

  The average particle size of the inorganic filler is preferably in the range of 0.01 μm to 4 μm from the viewpoint of increasing the fluidity of the resin composition and realizing sufficient part embedding and cavity filling properties, and 0.05 μm to 2 μm. The range is more preferable, the range of 0.1 μm to 1 μm is further preferable, and the range of 0.3 μm to 0.8 μm is even more preferable. 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 a laser diffraction scattering type 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 Co., Ltd.

  The inorganic filler surface-treated with the surface treatment agent can be washed with a solvent (for example, methyl ethyl ketone (MEK)), and then the amount of carbon per unit surface area of the inorganic filler can be measured. 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.

Carbon content per unit surface area of the inorganic filler, from the viewpoint of improving dispersibility of the inorganic filler is preferably 0.02 mg / ^{m 2} or more, 0.1 mg / ^{m 2} or more preferably, 0.2 mg / ^{m 2} The above is more preferable. On the other hand, from the viewpoint of preventing an increase in melt viscosity of the thermosetting resin composition layer, 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.

As the thermosetting resin used for the first thermosetting resin composition layer, a conventionally known thermosetting resin used when forming an insulating layer of a printed wiring board can be used, and among them, an epoxy resin is used. preferable. In one embodiment, the resin composition used for the first thermosetting resin composition layer includes an inorganic filler and an epoxy resin. The resin composition may also contain a curing agent as necessary. In one embodiment, the resin composition used for the first thermosetting resin composition layer includes an inorganic filler, an epoxy resin, and a curing agent. The resin composition used for the first thermosetting resin composition layer may further contain additives such as a thermoplastic resin, a curing accelerator, a flame retardant, and rubber particles.
Hereinafter, an epoxy resin, a curing agent, and an additive that can be used as a material for the resin composition will be described.

-Epoxy resin-
Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol novolak type epoxy resin, Phenol novolac type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, 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 epoxy resin, heterocyclic epoxy resin, spiro ring Epoxy resins, cyclohexanedimethanol type epoxy resins, naphthylene ether type epoxy resins and trimethylol type epoxy resins. An epoxy resin may be used individually by 1 type, or may use 2 or more types together.

  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. And a solid epoxy resin at a temperature of 20 ° C. (hereinafter referred to as “solid epoxy resin”). By using a liquid epoxy resin and a solid epoxy resin in combination as an epoxy resin, a resin composition having excellent flexibility can be obtained. Moreover, the breaking strength of the insulating layer formed by curing the resin composition is also improved.

  As the liquid epoxy resin, bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, or naphthalene type epoxy resin are preferable, and bisphenol A type epoxy resin, bisphenol F type epoxy resin, or naphthalene type epoxy resin are preferable. More preferred. Specific examples of the liquid epoxy resin include “HP4032”, “HP4032D”, “EXA4032SS”, “HP4032SS” (naphthalene type epoxy resin) manufactured by DIC Corporation, and “jER828EL” (bisphenol A) manufactured by Mitsubishi Chemical Corporation. Type epoxy resin), "jER807" (bisphenol F type epoxy resin), "jER152" (phenol novolac type epoxy resin), "ZX1059" (bisphenol A type epoxy resin and bisphenol F type epoxy) manufactured by Nippon Steel Chemical Co., Ltd. Resin mixture), “EX-721” (glycidyl ester type epoxy resin) manufactured by Nagase ChemteX Corporation, and the like. These may be used individually by 1 type, or may use 2 or more types together.

  The solid epoxy resin includes a tetrafunctional naphthalene type epoxy resin, a cresol novolac type epoxy resin, a dicyclopentadiene type epoxy resin, a trisphenol type epoxy resin, a naphthol novolac type epoxy resin, a biphenyl type epoxy resin, or a naphthylene ether type epoxy. Resin is preferable, tetrafunctional naphthalene type epoxy resin, biphenyl type epoxy resin, or naphthylene ether type epoxy resin is more preferable, and biphenyl type epoxy resin is more preferable. Specific examples of the solid epoxy resin include “HP-4700”, “HP-4710” (tetrafunctional naphthalene type epoxy resin), “N-690” (cresol novolac type epoxy resin) manufactured by DIC Corporation, “ N-695 ”(cresol novolac type epoxy resin),“ HP-7200 ”(dicyclopentadiene type epoxy resin),“ EXA7311 ”,“ EXA7311-G3 ”,“ EXA7311-G4 ”,“ EXA7311-G4S ”,“ HP6000 ” ”(Naphthylene ether type epoxy resin),“ EPPN-502H ”(trisphenol epoxy resin) manufactured by Nippon Kayaku Co., Ltd.,“ NC7000L ”(naphthol novolac epoxy resin),“ NC3000H ”,“ NC3000 ”,“ NC3000L ” ”,“ NC3100 ”(biphenyl type Xyresin), “ESN475” (naphthol novolac type epoxy resin) manufactured by Nippon Steel Chemical Co., Ltd., “ESN485V” (naphthol novolac type epoxy resin), “YX4000H”, “YL6121” (manufactured by Mitsubishi Chemical Corporation) ( Biphenyl type epoxy resin), “YX4000HK” (bixylenol type epoxy resin), “PG-100”, “CG-500” manufactured by Osaka Gas Chemical Co., Ltd., “YL7800” (fluorene type manufactured by Mitsubishi Chemical Corporation) Epoxy resin).

When a liquid epoxy resin and a solid epoxy resin are used in combination as the epoxy resin, the quantitative ratio thereof (liquid epoxy resin: solid epoxy resin) is in the range of 1: 0.1 to 1: 4 in terms of mass ratio. preferable. By making the quantitative ratio of the liquid epoxy resin and the solid epoxy resin within such a range, i) suitable adhesiveness is obtained when used in the form of an adhesive film, ii) when used in the form of an adhesive film Sufficient flexibility and handleability are improved, and iii) an insulating layer having sufficient breaking strength can be obtained. From the viewpoint of the effects i) to iii) above, the quantitative ratio of liquid epoxy resin to solid epoxy resin (liquid epoxy resin: solid epoxy resin) is from 1: 0.3 to 1: 3.5 in mass ratio. Is more preferable, the range of 1: 0.6 to 1: 3 is more preferable, and the range of 1: 0.8 to 1: 2.5 is particularly preferable.
The content of the epoxy resin in the resin composition is preferably 3% by mass to 50% by mass, more preferably 5% by mass to 45% by mass, still more preferably 5% by mass to 40% by mass, and 7% by mass to 35% by mass. % Is particularly preferred.

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

-Curing agent-
The curing agent is not particularly limited as long as it has a function of curing the epoxy resin. For example, a phenolic curing agent, a naphthol curing agent, an active ester curing agent, a benzoxazine curing agent, and a cyanate ester curing agent may be used. Can be mentioned. 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. Moreover, from a viewpoint of adhesiveness with a conductor layer (circuit wiring), a nitrogen-containing phenol type hardening | curing agent is preferable and a triazine frame | skeleton containing phenol type hardening | curing agent is more preferable. Among these, from the viewpoint of highly satisfying heat resistance, water resistance, and adhesiveness (peel strength) to the conductor layer, it is preferable to use a triazine skeleton-containing phenol novolac resin as a curing agent.

  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. Here, “dicyclopentadienyl diphenol” refers to a diphenol compound obtained by condensing two molecules of phenol with one molecule of dicyclopentadiene.

  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. The “dicyclopentadienyl diphenol structure” represents a divalent structural unit composed of phenylene-dicyclopentalene-phenylene.

  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′-methylenebis (2,6-dimethylphenyl cyanate), 4,4. '-Ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis (4-cyanate) phenylpropane, 1,1-bis (4-cyanatephenylmethane), bis (4-cyanate-3,5-dimethyl) Bifunctional cyanate resins such as phenyl) methane, 1,3-bis (4-cyanatephenyl-1- (methylethylidene)) benzene, bis (4-cyanatephenyl) thioether, and bis (4-cyanatephenyl) ether, phenol Novolac and K Polyfunctional cyanate resin derived from tetrazole 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.

  The amount ratio of the epoxy resin and the curing agent is preferably a ratio of [total number of epoxy groups of the epoxy resin]: [total number of reactive groups of the curing agent] in the range of 1: 0.2 to 1: 2. 1: 0.3-1: 1.5 are more preferable, and 1: 0.4-1: 1 are further 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 value obtained by dividing the solid mass of each epoxy resin by the epoxy equivalent for all epoxy resins, and the total number of reactive groups of the curing agent is: The value obtained by dividing the solid mass of each curing agent by the reactive group equivalent is the total value for all curing agents. By setting the amount ratio of the epoxy resin and the curing agent in such a range, the heat resistance of the cured product of the resin composition is further improved.

  In one embodiment, the resin composition used for the first thermosetting resin composition layer includes the above-described inorganic filler, epoxy resin, and curing agent. The resin composition includes silica as an inorganic filler and a mixture of a liquid epoxy resin and a solid epoxy resin as an epoxy resin (the mass ratio of liquid epoxy resin: solid epoxy resin is in the range of 1: 0.1 to 1: 4. Is preferable, a range of 1: 0.3 to 1: 3.5 is more preferable, a range of 1: 0.6 to 1: 3 is further preferable, and a range of 1: 0.8 to 1: 2.5 is particularly preferable. 1 or more selected from the group consisting of a phenolic curing agent, a naphthol curing agent, an active ester curing agent, and a cyanate ester curing agent (preferably a phenol curing agent and a naphthol curing agent). One or more selected from the group consisting of, more preferably one or more selected from the group consisting of a triazine skeleton-containing phenol novolak resin and a naphthol-based curing agent, more preferably The curing agent) containing a triazine skeleton-containing phenol novolak resin, it is preferable to include, respectively. Regarding the resin composition containing a combination of such specific components, the preferred content of the inorganic filler, the epoxy resin, and the curing agent is as described above. Among them, the content of the inorganic filler is 30% by mass. It is preferable that the content of the epoxy resin is 3% by mass to 50% by mass, the content of the inorganic filler is 50% by mass to 90% by mass, and the content of the epoxy resin is 5% by mass to 45%. More preferably, it is mass%. Regarding the content of the curing agent, the ratio of the total number of epoxy groups of the epoxy resin to the total number of reactive groups of the curing agent is preferably in the range of 1: 0.2 to 1: 2, more preferably 1: It is contained so as to be in the range of 0.3 to 1: 1.5, more preferably in the range of 1: 0.4 to 1: 1.

  The resin composition may further contain additives such as a thermoplastic resin, a curing accelerator, a flame retardant, and rubber particles as necessary.

-Thermoplastic resin-
Examples of the thermoplastic resin include phenoxy resin, polyvinyl acetal resin, polyolefin resin, polybutadiene resin, polyimide resin, polyamideimide resin, polyethersulfone resin, polyphenylene ether resin, and polysulfone resin. A thermoplastic resin may be used individually by 1 type, or may use 2 or more types together.

  The weight average molecular weight in terms of polystyrene of the thermoplastic resin is preferably in the range of 8,000 to 70,000, more preferably in the range of 10,000 to 60,000, and 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 measured at a column temperature of 40 ° C. using chloroform or the like as a mobile phase, and can be calculated using a standard polystyrene calibration curve.

  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, or may use 2 or more types together. 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 Toto Kasei Co., Ltd., “YL7553”, “YL6794”, “YL7213” manufactured by Mitsubishi Chemical Corporation, YL7290 "," YL7482 ", etc. are mentioned.

  Specific examples of the polyvinyl acetal resin include: Electric Butyral 4000-2, 5000-A, 6000-C, 6000-EP manufactured by Denki Kagaku Kogyo Co., Ltd. KS series, BL series, BM series, etc. are mentioned.

  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 (described in JP-A-2006-37083), a polysiloxane skeleton. Examples thereof include modified polyimides such as containing polyimide (described in JP-A No. 2002-12667 and JP-A No. 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 polysiloxane skeleton-containing polyamideimides “KS9100” and “KS9300” 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.

  The content of the thermoplastic resin in the resin composition is preferably 0.1% by mass to 20% by mass. By setting the content of the thermoplastic resin within such a range, the viscosity of the resin composition becomes appropriate, and a uniform resin composition having a thickness and a bulk property can be formed. The content of the thermoplastic resin in the resin composition is more preferably 0.5% by mass to 10% 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.

  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.

  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.

  A hardening accelerator may be used individually by 1 type, and may be used in combination of 2 or more type. The content of the curing accelerator in the resin composition is preferably in the range of 0.05% by mass to 3% by mass when the total amount of nonvolatile components of the epoxy resin and the curing agent is 100% by mass.

-Flame retardant-
Examples of the flame retardant include an organic phosphorus flame retardant, an organic nitrogen-containing phosphorus compound, a nitrogen compound, a silicone flame retardant, and a metal hydroxide. A flame retardant may be used individually by 1 type, or may use 2 or more types together. The content of the flame retardant in the resin composition layer is not particularly limited, but is preferably 0.5% by mass to 10% by mass, more preferably 1% by mass to 9% by mass, and 1.5% by mass to 8% by mass. Is more preferable.

-Rubber particles-
As the rubber particles, for example, those that do not dissolve in an organic solvent described later and are incompatible with the above-described epoxy resin, curing agent, thermoplastic resin, and the like are used. Such rubber particles are generally prepared by increasing the molecular weight of the rubber component to a level at which it does not dissolve in an organic solvent or resin and making it into particles.

  Examples of the rubber particles include core-shell type rubber particles, cross-linked acrylonitrile butadiene rubber particles, cross-linked styrene butadiene rubber particles, and acrylic rubber particles. The core-shell type rubber particles are rubber particles having a core layer and a shell layer. For example, a two-layer structure in which an outer shell layer is made of a glassy polymer and an inner core layer is made of a rubbery polymer, or Examples include a three-layer structure in which the outer shell layer is made of a glassy polymer, the intermediate layer is made of a rubbery polymer, and the core layer is made of a glassy polymer. The glassy polymer layer is made of, for example, methyl methacrylate polymer, and the rubbery polymer layer is made of, for example, butyl acrylate polymer (butyl rubber). A rubber particle may be used individually by 1 type, or may use 2 or more types together.

  The average particle size of the rubber particles is preferably in the range of 0.005 μm to 1 μm, more preferably in the range of 0.2 μm to 0.6 μm. The average particle diameter of the rubber particles can be measured using a dynamic light scattering method. For example, rubber particles are uniformly dispersed in an appropriate organic solvent by ultrasonic waves, etc., and a particle size distribution of rubber particles is created on a mass basis using a concentrated particle size analyzer (FPAR-1000; manufactured by Otsuka Electronics Co., Ltd.). And it can measure by making the median diameter into an average particle diameter. The content of the rubber particles in the resin composition is preferably 1% by mass to 10% by mass, and more preferably 2% by mass to 5% by mass.

  The resin composition used for the first thermosetting resin composition layer may contain other additives as necessary. Examples of such other additives include organic copper compounds and organic zinc. Examples thereof include organometallic compounds such as compounds and organic cobalt compounds, and resin additives such as organic fillers, thickeners, antifoaming agents, leveling agents, adhesion imparting agents, and coloring agents.

  The thickness of the first thermosetting resin composition layer is preferably 100 μm or less, more preferably 80 μm or less, and even more preferably from the viewpoint of reducing the thickness of the component-embedded circuit board, although it depends on the thickness of the circuit board. Is 60 μm or less, and more preferably 50 μm or less. Although the lower limit of the thickness of the first thermosetting resin composition layer depends on the thickness of the circuit board and the like, it is usually 15 μm or more from the viewpoint of component embedding property and cavity filling property.

  The minimum melt viscosity of the first thermosetting resin composition layer is preferably 10,000 poises or less, more preferably 8000 poises, from the viewpoint of realizing sufficient component embedding property and cavity filling property in the production of the component built-in circuit board. Hereinafter, it is more preferably 6000 poise or less, even more preferably 4000 poise or less, and particularly preferably 3000 poise or less. The lower limit of the minimum melt viscosity of the first thermosetting resin composition layer is preferably 100 poises or more, more preferably 300 poises or more, from the viewpoint of layer shape retention (prevention of bleeding) in the production of a component-embedded circuit board. More preferably, it is 500 poise or more.

  Here, the “minimum melt viscosity” of the thermosetting resin composition layer refers to the lowest viscosity exhibited by the thermosetting resin composition layer when the resin of the thermosetting resin composition layer is melted. Specifically, when the thermosetting resin composition layer 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 a certain temperature is exceeded, the temperature increases. Increases melt viscosity. “Minimum melt viscosity” refers to the melt viscosity at such a minimum point. The minimum melt viscosity of the thermosetting resin composition layer can be measured by a dynamic viscoelastic method. Specifically, the minimum melt viscosity of the thermosetting resin composition layer is determined by performing dynamic viscoelasticity measurement under 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. Can be obtained. Examples of the dynamic viscoelasticity measuring apparatus include “Rheosol-G3000” manufactured by UBM Co., Ltd.

(Second adhesive film)
The second adhesive film includes a second support and a second thermosetting resin composition layer bonded to the second support.

  The material and thickness of the second support may be the same as described for the first support.

  The material of the second thermosetting resin composition layer may be the same as that described for the first thermosetting resin composition layer.

  The second thermosetting resin composition layer may be thinner than the first thermosetting resin composition layer. The thickness of the second thermosetting resin composition layer is preferably 80 μm or less, more preferably 60 μm or less, still more preferably 40 μm or less, and even more preferably 30 μm or less, from the viewpoint of thinning the component-embedded circuit board. is there. The lower limit of the thickness of the first thermosetting resin composition layer is not particularly limited, but is usually 10 μm or more.

  The minimum melt viscosity of the second thermosetting resin composition layer is preferably 100 poises or more, more preferably 300 poises or more, and even more preferably from the viewpoint of layer retention (prevention of bleeding) in the production of a component-embedded circuit board. Is over 500 poise. The upper limit of the minimum melt viscosity of the second thermosetting resin composition layer is not particularly limited, but may be in the same range as that described for the first thermosetting resin composition layer.

  Hereinafter, an example of a procedure for producing the first and second adhesive films is shown.

  Regardless of whether the adhesive film is a first adhesive film or a second adhesive film, for example, a resin varnish in which a resin composition is dissolved in an organic solvent is prepared, and this resin varnish is formed on a support using a die coater or the like. It can be produced by applying and drying the resin 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 thermosetting resin composition layer can be formed thereon.

  The adhesive film is a protective film on the surface of the thermosetting resin composition layer that is not joined to the support (that is, the surface opposite to the support), regardless of whether the first and second adhesive films are used. May further be included. The protective film contributes to the prevention of adhesion and scratches of dust on the surface of the thermosetting resin composition layer. As the material for the protective film, the same materials as described for the support may be used. Although the thickness of a protective film is not specifically limited, For example, they are 1 micrometer-40 micrometers. The adhesive film can be used by removing the protective film when manufacturing the component built-in circuit board.

  As mentioned above, although an example of the procedure which produces the 1st and 2nd adhesive film was shown, as long as the 1st and 2nd adhesive film is obtained, it is not limited to said procedure. For example, after forming a thermosetting resin composition layer on a protective film, a support may be laminated on the thermosetting resin composition layer to produce an adhesive film. In the present invention, the “support” refers to a member laminated on the main surface of the circuit board together with the thermosetting resin composition layer in the production of the component built-in circuit board. The supporting member is not limitedly represented.

  Hereinafter, the manufacturing method of the component built-in circuit board of this invention is demonstrated in detail according to the suitable embodiment.

[Manufacturing method of component built-in circuit board]
The manufacturing method of the component built-in circuit board of the present invention includes the following steps (A), (B), (C) and (D) in this order.
(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 first support body and a first support body on a circuit board on which a part is temporarily attached, the part including a temporary attachment material and a part temporarily attached with the temporary attachment material inside a cavity of the circuit board The first adhesive film including the first thermosetting resin composition layer to be bonded to the substrate is vacuum laminated so that the first thermosetting resin composition layer is bonded to the first main surface of the circuit board. (B) heat-treating the first thermosetting resin composition layer in the following step (C) to suppress positional deviation of the component, and the heat treatment suppresses the occurrence of substrate warpage. (C) After removing the tacking material from the second main surface of the circuit board, the second step A second adhesive film including a support and a second thermosetting resin composition layer bonded to the second support is used as the second thermosetting resin composition layer. (D) The process of thermosetting the 1st and 2nd thermosetting resin composition layer so that it may join to a surface

In the present invention, “including in this order” for the steps (A) to (D) includes the steps (A) to (D) and includes the steps (A) to (D). As long as it is performed in this order, it does not prevent including other steps.
Hereinafter, the same applies to “include in this order” for the steps or processes.

  Hereinafter, each process will be described with reference to FIGS. 3A to 3G.

<Process (A)>
In the step (A), the first adhesive film 10 and the first thermosetting resin composition layer 12 are bonded to the first main surface of the circuit board on the circuit board 1 ′ to which the component is temporarily attached. Is laminated in a vacuum (FIG. 3A).

  The configurations of the circuit board 1 ′ and the first adhesive film 10 on which components are temporarily attached are as described above.

  For example, vacuum lamination of the first adhesive film 10 to the component tack circuit board 1 ′ is performed by, for example, applying the first adhesive film 10 to the component tack circuit board 1 ′ from the first 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 adhesive film 10 to the component temporary circuit board 1 ′, for example, a heated metal plate (SUS end plate, etc.) Or a metal roll (SUS roll) etc. are mentioned. In addition, the 1st adhesive film 10 fully tracks the unevenness | corrugation resulting from the circuit wiring 3 and the cavity 2a of component temporary attachment circuit board 1 'rather than directly pressing the thermocompression bonding member to the 1st adhesive film 10. It is preferable to press through an elastic material such as heat resistant rubber.

  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. The thermocompression bonding temperature refers to the surface temperature of the thermocompression bonding member, and refers to the temperature of the surface of the elastic material to be bonded to the first adhesive film 10 when pressed through an elastic material such as heat-resistant rubber.

  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, a vacuum applicator manufactured by Nichigo Morton, and the like.

  In the step (A), the first thermosetting resin composition layer 12 is filled in the cavity 2a, and the component 5 temporarily attached in the cavity 2a is replaced with the first thermosetting resin composition layer. 12 (FIG. 3B).

  After the step (A), smoothing for smoothing the laminated first adhesive film by pressing the thermocompression bonding member from the first support 11 side under normal pressure (under atmospheric pressure), for example. It is preferable to perform a process (hereinafter also referred to as “process (A ′)”). The pressing conditions in the step (A ′) can be the same conditions as the thermocompression bonding conditions for the vacuum lamination.

  Step (A ′) can be performed with a commercially available laminator. In addition, you may perform a process (A) and a process (A ') continuously using said commercially available vacuum laminator.

  In the step (A), the first thermosetting resin composition layer 12 is filled in the cavity 2a, and the component 5 temporarily attached in the cavity 2a is replaced with the first thermosetting resin composition layer. 12 (FIG. 3B).

<Process (B)>
In the step (B), the first thermosetting resin composition layer is subjected to heat treatment in order to suppress positional displacement of the component in the following step (C), and the heat treatment suppresses occurrence of substrate warpage. Perform within the range.

  In the prior art, after the thermosetting resin composition layer is provided on one main surface of the component temporary circuit board, the thermosetting resin composition layer is thermoset and the main component circuit board on one side is temporarily cured. A cured body (insulating layer) was formed on the surface. In such a technique, since the cured body (insulating layer) for sealing the component is obtained by thermosetting the thermosetting resin composition layer in which the component is embedded, the position change of the component due to the subsequent process is obtained. (Displacement) did not occur, and the placement accuracy of the components in the cavity was excellent. However, as described above, in such a technique, when a circuit board with a high cavity density or a circuit board with a small thickness is used in order to achieve a reduction in size and thickness of a circuit board with a built-in component, one of the circuit boards is used. The present inventors have found that the substrate warpage may occur at the stage of forming the insulating layer on the main surface. When the substrate warpage occurs, the substrate conveyance is hindered and the manufacturing efficiency (yield) is lowered. Therefore, a technique capable of suppressing the occurrence of the substrate warpage is required.

  Specifically, the substrate warp becomes apparent in the process of cooling from the thermosetting temperature to room temperature after forming the insulating layer. Therefore, in order to suppress generation | occurrence | production of board | substrate curvature, it is also considered to implement the next process, without cooling from thermosetting temperature. However, it is not realistic to maintain the thermosetting temperature from the thermosetting step to the second adhesive film laminating step, and there is also a problem that it is difficult to peel off the tacking material. Further, by laminating an adhesive film having a thermosetting resin composition layer having a high melt viscosity on a component temporary circuit board, the position change (displacement) of the component in the cavity can be prevented without going through a thermosetting process. However, if an adhesive film with a thermosetting resin composition layer with a high minimum melt viscosity is used, sufficient component embedding and cavity filling properties cannot be obtained in the first place, resulting in poor component fixing. It is not a practical solution. In this way, when using a circuit board with a high cavity density or a circuit board with a small thickness to achieve miniaturization and thinning of the circuit board with a built-in component, the board maintains good component placement accuracy. It was difficult to suppress the occurrence of warpage.

  By laminating a thermosetting resin composition layer on one main surface of a component tack circuit board, the present inventors heat-treat the thermosetting resin composition layer under specific conditions ( That is, it has been found that by adopting the above step (B), the occurrence of substrate warpage can be suppressed even after cooling to room temperature. In addition, according to such a method, since an adhesive film having a thermosetting resin composition layer having an appropriate minimum melt viscosity can be used, sufficient embeddability of parts and cavity filling ability when the adhesive film is laminated. Can be achieved. As described above, the present invention maintains good component placement accuracy even when a circuit board with a high cavity density or a thin circuit board is used in order to reduce the size and thickness of a circuit board with a built-in component. It is possible to suppress the occurrence of substrate warping. Therefore, the present invention can manufacture a small and thin component-embedded circuit board with a high yield, and contributes significantly to making the component-embedded circuit board smaller and thinner.

  In a preferred embodiment, a test piece having a planar dimension of L (mm) × W (mm) (where L ≧ W and L is 550 mm or less) is obtained from the substrate obtained in step (B). The warp of the test piece is 0.1 L (mm) or less. A test piece having a planar dimension of L (mm) × W (mm) can be obtained by cutting the substrate obtained in the step (B) into a dimension of L (mm) × W (mm). In addition, when using the component temporary circuit board which satisfy | fills the planar dimension of said L (mm) x W (mm), you may use the board | substrate obtained at a process (B) as a test piece as it is. The warp of the test piece refers to the warp of the test piece when cooled to room temperature (room temperature) of 15 ° C. to 40 ° C. after the step (B). Note that the warp of the test piece is the vertical height of both ends of the opposite side (side of dimension W) from the horizontal surface when one side (side of dimension W) is fixed to the horizontal surface with a fixture. It means the arithmetic mean value. Specifically, the warp of the test piece (substrate) can be measured by the measurement method described in the examples.

  In a preferred embodiment, the warpage of the substrate obtained in the step (B) is preferably 0.09 L (mm) or less, more preferably 0.08 L (mm) or less, and further preferably 0.07 L (mm) or less. Even more preferably, it is 0.06 L (mm) or less, particularly preferably 0.05 L (mm) or less, 0.04 L (mm) or less, 0.03 L (mm) or less, or 0.02 L (mm) or less. .

  The dimension L of the test piece is preferably 300 mm or less. The lower limit of the dimension L of the test piece can be usually 50 mm or more, 100 mm or more, or 200 mm or more. The dimension W of the test specimen can usually be L ≧ W ≧ 0.5L, L ≧ W ≧ 0.7L, or L ≧ W ≧ 0.9L.

In the step (B), from the viewpoint of suppressing the occurrence of substrate warp, the first thermosetting resin composition layer has a minimum melt viscosity of preferably 200,000 poise or less, more preferably 180,000 poise. Hereinafter, more preferably 160,000 poise or less, still more preferably 140,000 poise or less, particularly preferably 120,000 poise or less, 100,000 poise or less, 90,000 poise or less, 80,000 poise or less, or 70 It is preferable that the heat treatment is performed so as to be equal to or less than 1,000 poise. Further, from the viewpoint of suppressing the positional change (displacement) of the parts, the first thermosetting resin composition layer has a minimum melt viscosity of preferably 15,000 poise or more, more preferably 16,000 poise or more, More preferably 18,000 poise or more, even more preferably 20,000 poise or more, particularly preferably 22,000 poise or more, 25,000 poise or more, 30,000 poise or more, or 35,000 poise or more. Heat treatment is preferable.
In the step (B), the minimum melt viscosity of the heat-treated first thermosetting resin composition layer can be measured in the same manner as described above. In measuring the minimum melt viscosity of the first thermosetting resin composition layer in the step (B), the measurement start temperature may be 100 ° C.

  The conditions for the heat treatment of the first thermosetting resin composition layer in the step (B) are the heat treatment for suppressing the positional deviation of the component in the following step (C), and the heat treatment is performed for the substrate warpage. There is no particular limitation as long as it is performed within a range where generation is suppressed. In a preferred embodiment, the heating temperature in the step (B) is preferably 155 ° C. or less, more preferably 150 ° C. or less, further preferably 145 ° C. or less, from the viewpoint of achieving the minimum melt viscosity in the specific range. Even more preferably, it is 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.

  Although the heating time in the step (B) depends on the heating temperature, it 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 first thermosetting resin composition layer in the step (B) is preferably performed under atmospheric pressure (under normal pressure).

  The heat treatment of the first thermosetting resin composition layer in the step (B) may be performed with the first support 11 attached to the first thermosetting resin composition layer 12. It may be carried out after the first support 11 is peeled off and the first thermosetting resin composition layer 12 is exposed. In a preferred embodiment, the heat treatment of the first thermosetting resin composition layer in the step (B) is performed when the first support 11 is attached to the first thermosetting resin composition layer 12. To implement. This is advantageous in terms of preventing foreign matter adhesion and preventing damage to the first thermosetting resin composition layer.

  When the heat treatment of the first thermosetting resin composition layer in the step (B) is carried out with the first support attached, the first support is the first thermosetting resin composition. What is necessary is just to peel before the process of providing a conductor layer (circuit wiring) in the insulating layer obtained by hardening a physical layer, for example, you may peel between a process (B) and the process (C) mentioned later. In addition, it may be peeled off between step (C) and step (D) described later, or may be peeled off after step (D) described later. In a preferred embodiment, the first support is peeled off after the step (D) described later. When a metal foil such as a copper foil is used as the first support, it is possible to provide a conductor layer (circuit wiring) using such a metal foil as described later. The support may not be peeled off.

  In a preferred embodiment, a process of cooling the circuit board to room temperature (room temperature) may be performed between step (A) and step (B).

  In a preferred embodiment, in step (B), the first thermosetting resin composition layer 12 is a first thermosetting resin having a minimum melt viscosity in the range of 15,000 poise to 200,000 poise. It becomes a composition layer (heat treatment body) 12 '(FIG. 3C). FIG. 3C shows a mode in which the first thermosetting resin composition layer (heat treatment body) 12 ′ is obtained by heat treatment with the first support 11 attached.

<Process (C)>
After the step (B), the temporary attachment material 4 is peeled from the second main surface of the circuit board to expose the second main surface of the circuit board. Then, the second adhesive film 20 is vacuum laminated so that the second thermosetting resin composition layer 22 is bonded to the second main surface of the circuit board (FIG. 3D).

  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 off after the tacking material 4 is irradiated with UV. . 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.

  The configuration of the second adhesive film 20 is as described above. In addition, the 2nd support body 21 of the 2nd adhesive film 20 used at a process (C) may be the same as the 1st support body 11 of the 1st adhesive film 10 used at a process (A), and is different. Also good. Moreover, even if the resin composition used for the 2nd thermosetting resin composition layer 22 used at a process (C) is the same as the resin composition used for the 1st thermosetting resin composition layer used at a process (A). Well, it can be different.

  According to the manufacturing method of the present invention that employs the step (B), even when a circuit board having a high cavity density or a circuit board having a small thickness is used in order to achieve miniaturization and thinning of the component-embedded circuit board. Since generation | occurrence | production of a board | substrate curvature can be suppressed, a process (C) can be smoothly implemented, without affecting the board | substrate conveyance from a process (B) to a process (C). Furthermore, since the first thermosetting resin composition layer is heat-treated under specific conditions, the position change (displacement) of the components accompanying the vacuum lamination in the step (C) can be suppressed, A component built-in circuit board having excellent component placement accuracy can be realized with a high yield.

  In a preferred embodiment, in step (C), the positional deviation of the component is less than 40 μm. Here, the positional displacement of the components means the center of the components after the first thermosetting resin composition layer is heat-treated in the step (B) and the second thermosetting resin composition in the step (C). Refers to the change in position with the center of the part after the layers are vacuum laminated. Specifically, the positional deviation of the components can be measured by the measuring method described in the examples.

  For the vacuum lamination of the second adhesive film 20 in the step (C), the same method and conditions as the vacuum lamination of the first adhesive film in the step (A) may be employed.

  In a preferred embodiment, a process of cooling the circuit board to room temperature (room temperature) may be performed between step (B) and step (C).

  In the step (C), the second thermosetting resin composition layer 22 and the second support 21 are laminated on the second main surface of the circuit board (FIG. 3E).

  The second support 21 may be peeled off before the step of providing the conductor layer (circuit wiring) on the insulating layer obtained by curing the second thermosetting resin composition layer. For example, the step (C) And may be peeled after the step (D) described later, or after the step (D) described later. In a preferred embodiment, the second support is peeled off after the step (D) described later. When a metal foil such as a copper foil is used as the second support, it is possible to provide a conductor layer (circuit wiring) using such a metal foil, as will be described later. The support may not be peeled off.

<Process (D)>
In the step (D), the first and second thermosetting resin composition layers are thermoset. Thus, the first thermosetting resin composition layer (heat treatment body) 12 ′ forms the insulating layer 12 ″, and the second thermosetting resin composition layer 22 forms the insulating layer 22 ″ (see FIG. 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.

  For example, the thermosetting conditions of the first and second thermosetting resin composition layers vary depending on the composition of the resin composition used for each thermosetting resin composition layer, but the curing temperature is 120 ° C to 240 ° C. (Preferably in the range of 150 ° C. to 210 ° C., more preferably in the range of 170 ° C. to 190 ° C.), and 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).

  Before thermosetting, the first and second thermosetting resin composition layers may be preheated at a temperature lower than the curing temperature. For example, the first and second thermosetting resin compositions 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) prior to thermosetting. The layer may be preheated 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 step (D).

  The thermosetting of the first and second thermosetting resin composition layers in the step (D) is preferably performed under atmospheric pressure (under normal pressure).

  The step (D) is preferably performed with the substrate kept substantially horizontal. For example, the step (D) is preferably performed in a state where the axis in the thickness direction of the substrate is in a range of 80 ° to 100 ° with respect to the horizontal plane.

  In a preferred embodiment, a process of cooling the circuit board to room temperature (room temperature) may be performed between step (C) and step (D).

  In the following description, the insulating layer 12 ″ obtained by thermosetting the first thermosetting resin composition layer (heat-treated body) 12 ′ may be referred to as “first insulating layer”. . Further, the insulating layer 22 ″ obtained by thermosetting the second thermosetting resin composition layer 22 may be referred to as a “second insulating layer”.

<Other processes>
The method for manufacturing a component-embedded circuit board according to the present invention further includes (E) a step of drilling holes in the first and second insulating layers, (F) a step of roughening the first and second insulating layers, (G ) A step of forming a conductor layer on the roughened insulating layer surface may be further included. These steps (E) to (G) may be carried out 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 a 1st and 2nd support body after a process (D), peeling of this 1st and 2nd support body is a process (E) between a process (D) and a process (E). ) And step (F), or between step (F) and step (G).

  Step (E) is a step of drilling holes in the first and second insulating layers, whereby holes such as via holes can be formed in the first and second insulating layers. For example, holes can be formed in the first and second insulating layers using a drill, laser (carbon dioxide laser, YAG laser, etc.), plasma, or the like. In the component built-in circuit board, the insulating layer is generally conducted by a via hole.

  Step (F) is a step of roughening the first and second insulating layers. The procedure and conditions of the roughening treatment are not particularly limited, and known procedures and conditions that are usually used when forming the insulating layer of the component built-in circuit board can be adopted. For example, the roughening treatment of the first and second insulating layers 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 liquid in this order. Can be roughened. 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. Although the swelling process by a swelling liquid is not specifically limited, For example, it can carry out by immersing a 1st and 2nd insulating layer for 1 minute-20 minutes in 30-90 degreeC swelling liquid. From the viewpoint of suppressing the swelling of the resin of the first and second insulating layers to an appropriate level, it is preferable to immerse the first and second insulating layers in a swelling liquid 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.

  Step (G) 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 is generally 3 μm to 35 μm, preferably 5 μm to 30 μm, although it depends on the desired design of the component built-in circuit board.

  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 first and second insulating layers 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 first and second insulating layers 12 ″ and 22 ″ and the circuit wiring on the circuit board are electrically connected. Are connected to each other, and the component built-in circuit board 100 is obtained (FIG. 3G). As long as electrical connection is provided, the inside of the via hole does not need to be filled with a conductor, and a thin layer of conductor may be formed so as to coat the wall surface of the via hole.

  When metal foil such as copper foil is used as the first and second supports, the 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 component built-in circuit board according to the present invention may also include (H) a step of dividing the component built-in circuit board into individual pieces.

  In the step (H), for example, the structure obtained by grinding with a conventionally known dicing apparatus having a rotary blade can be separated into individual circuit board units with built-in components.

  As mentioned above, although the manufacturing method of the component built-in circuit board of this invention was demonstrated according to suitable embodiment, each process of the process (A) thru | or (D) was included including each process of the said process (A) thru | or (D). As long as the steps are performed in this order, the present invention is not limited to the embodiments specifically shown above. For example, the step (H) is performed between the step (C) and the step (D), between the step (D) and the step (E), between the step (E) and the step (F), or in the step (F). You may perform during a process (G). Further, the steps (A) to (G) may be repeated to increase the number of layers. Many variations of the method for manufacturing a component-embedded circuit board according to the present invention are conceivable.

[Semiconductor device]
A semiconductor device can be manufactured using the component built-in circuit board manufactured by the method of the present invention.

  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.

  First, various measurement methods and evaluation methods will be described.

[Preparation of samples for measurement and evaluation]
(1) Preparation of a circuit board on which components are temporarily attached A cavity of 0.8 mm × 1.2 mm size penetrating between the first and second main surfaces of the inner layer circuit board in an inner layer circuit board of 255 mm × 255 mm size Was made at a pitch of 5 mm. As the inner layer circuit board, a glass cloth base epoxy resin double-sided copper-clad laminate on which an inner layer circuit is formed (the thickness of the copper foil on one side is 18 μm, the thickness of the substrate is 150 μm, the total thickness is 186 μm, manufactured by Matsushita Electric Works, Ltd. R5715ES ") was used. Next, both surfaces of the inner circuit board in which the cavities were formed were etched by 1 μm using “CZ8100” manufactured by Mec Co., Ltd. to roughen the copper surface. Thereafter, a temporary attachment material (UV tape UC for wafer dicing manufactured by Furukawa Electric Co., Ltd.) is bonded to one side (second main surface) of the inner layer circuit board, and the temporary attachment material exposed through the cavity of the inner layer circuit board. A part (a multilayer thin film capacitor 1005 manufactured by Murata Manufacturing Co., Ltd., 1.0 mm × 0.5 mm size, thickness 180 μm) was temporarily attached to the adhesive surface.

(2) Vacuum lamination of first adhesive film The first adhesive film produced in the following production example was applied to the inner-layer circuit board on which the component was temporarily attached obtained in (1) above with a batch type vacuum pressure laminator ( Using a “MVLP-500” manufactured by Meiki Seisakusho, vacuum lamination was performed so that the first thermosetting resin composition layer was in contact with the first main surface of the inner circuit board. In vacuum lamination of the first adhesive film, the pressure was reduced to 30 hPa by reducing the pressure for 30 seconds, and then the lamination was performed at 110 ° C. and a pressure of 0.74 MPa for 30 seconds. Further, smoothing treatment was performed by hot pressing at 110 ° C. and a pressure of 0.5 MPa for 60 seconds under normal pressure.
In addition, the 1st adhesive film was used for this process, after peeling a protective film. This step corresponds to step (A).

(3) Heat treatment of the first thermosetting resin composition layer The inner layer circuit board on which the first adhesive film is laminated is heated under normal pressure at the temperatures and times shown in Table 2 below, to obtain the first heat The curable resin composition layer was heat-treated. The obtained substrate is referred to as “evaluation substrate a”. This step corresponds to step (B).

(4) Peeling of temporary attachment material After UV irradiation of temporary attachment material, the temporary attachment material was peeled off from the evaluation board | substrate a, and the 2nd main surface of the inner-layer circuit board was exposed. The obtained substrate is referred to as “evaluation substrate b”.

(5) Vacuum lamination of the second adhesive film The second adhesive film produced in the following production example was subjected to the second using a batch type vacuum pressure laminator (“MVLP-500” manufactured by Meiki Seisakusho Co., Ltd.). The thermosetting resin composition layer was vacuum-laminated on the evaluation substrate b so as to be in contact with the second main surface of the inner circuit board. In vacuum lamination of the second adhesive film, the pressure was reduced to 30 hPa or less by reducing the pressure for 30 seconds, and then the laminate treatment was performed at 110 ° C. and a pressure of 0.74 MPa for 30 seconds. Further, smoothing treatment was performed by hot pressing at 110 ° C. and a pressure of 0.5 MPa for 60 seconds under normal pressure. The obtained substrate is referred to as “evaluation substrate c”.
In addition, the 2nd adhesive film was used for this process, after peeling a protective film. This step corresponds to step (C).

(6) Thermosetting of the first and second thermosetting resin composition layers The evaluation substrate c is heated under normal pressure at 100 ° C. for 30 minutes, then at 180 ° C. for 30 minutes, and the first and second The thermosetting resin composition layer was thermally cured to form insulating layers on both sides of the inner layer circuit board. This step corresponds to step (D).

<Measurement of minimum melt viscosity of thermosetting resin composition layer>
About the 1st thermosetting resin composition layer in the 1st adhesive film produced in the following preparation examples, using a dynamic viscoelasticity measuring apparatus ("Rhesol-G3000" by UBM). The minimum melt viscosity was measured. About 1 g of the sample resin composition, using a parallel plate with a diameter of 18 mm, the temperature was increased from a starting temperature of 60 ° C. to 200 ° C. at a rate of temperature increase of 5 ° C./min. The dynamic viscoelastic modulus was measured under a measurement condition of 1 deg, and the minimum melt viscosity (poise) was calculated.
Moreover, the 1st thermosetting resin composition layer in a 1st adhesive film was heat-processed on the heating conditions of Table 2, and it carried out similarly to the above except that the starting temperature was 100 degreeC. The minimum melt viscosity of the thermosetting resin composition layer 1 was measured.

<Evaluation of substrate warpage>
The evaluation of the substrate warpage was performed using the evaluation substrate b as shown in FIG. Specifically, the opposite side (AB) from the horizontal surface 30 when one side (CD side) of the evaluation substrate b (50 in FIG. 4) is fixed to the horizontal surface 30 by the fixture 31 at room temperature (23 ° C.). The vertical heights (h _A and h _B ) of both ends of the side), that is, the A end and the B end were measured, and the average value ((h _A + h _B ) / 2) was obtained. And the board | substrate curvature was evaluated based on the following reference | standard. In addition, when the average value in this evaluation is larger than 25 mm, troubles are likely to occur in substrate conveyance in the step of vacuum lamination of the second adhesive film.
Evaluation criteria:
○: Average value is 25 mm or less ×: Average value is greater than 25 mm

<Evaluation of component misalignment>
The change of the part position before and after lamination | stacking of a 2nd adhesive film was measured with the optical microscope ("VH-5500" by Keyence). In the measurement, a change in the position of the target component between the evaluation board b and the evaluation board c was measured. In this evaluation, the center of the component was used as a reference point, and the positional change (μm) of the reference point was measured. And the positional offset of components was evaluated based on the following evaluation criteria.
Evaluation criteria:
○: Change in position is less than 40 μm ×: Change in position is 40 μm or more

[Production Example 1]
(1) Preparation of resin varnish 5 parts of bisphenol type epoxy resin (“ZX1059” manufactured by Nippon Steel Chemical Co., Ltd., 1: 1 mixture of bisphenol A type and bisphenol F type, epoxy equivalent of about 169), naphthalene type epoxy resin (“HP4032SS” manufactured by DIC Corporation, epoxy equivalent of about 144), 5 parts of bixylenol type epoxy resin (“YX4000HK” manufactured by Mitsubishi Chemical Corporation, about 185 of epoxy equivalent), biphenyl type epoxy resin (Nippon Kayaku) 15 parts of “NC3000H” manufactured by (Co), and 10 parts of phenoxy resin (“YL7553BH30” manufactured by Mitsubishi Chemical Co., Ltd., MEK solution having a weight average molecular weight of about 35000 and a solid content of 30%) are mixed with solvent naphtha. While stirring, 25 parts were dissolved with heating. After cooling to room temperature, 10 parts of a triazine skeleton-containing phenol novolac-based curing agent (“LA-7054” manufactured by DIC Corporation, MEK solution having a hydroxyl equivalent weight of 125 and a solid content of 60%), a naphthol-based curing agent ( “SN-485” manufactured by Nippon Steel Chemical Co., Ltd., 10 parts of hydroxyl equivalent 215, 60% solid content MEK solution, curing accelerator (4-dimethylaminopyridine (DMAP), 5% solid content 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 size 2 μm) 3 parts, spherical silica surface treated with an aminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) (“SOC2” manufactured by Admatechs Co., Ltd.) Particle size 0.5 [mu] m, the carbon amount 0.39 mg ^/ m 2 per unit surface area) were mixed 100 parts, was uniformly dispersed in a high-speed rotary mixer to prepare a resin varnish.
When the total of the non-volatile components in the resin varnish was 100% by mass, the content of the inorganic filler (spherical silica) was 67.5% by mass.
(2) Production of first adhesive film 1 As a support, a PET film with an alkyd resin release layer (“AL5” manufactured by Lintec Corporation, thickness 38 μm) was prepared. The resin varnish prepared above is uniformly applied to the release layer side surface of the support with a die coater and dried at 80 ° C. to 120 ° C. (average 100 ° C.) for 5 minutes to be a first thermosetting resin. A composition layer was formed. The thickness of the first thermosetting resin composition layer was 50 μm. Next, a smooth surface side of a polypropylene film (“Alphan MA-411” manufactured by Oji Specialty Paper Co., Ltd., thickness 15 μm) as a protective film is bonded to the surface of the first thermosetting resin composition layer, 1 adhesive film 1 was prepared.
(3) Production of Second Adhesive Film 1 As a support, a PET film with an alkyd resin release layer (“AL5” manufactured by Lintec Corporation, thickness 38 μm) was prepared. The resin varnish prepared above is uniformly applied to the surface of the release layer side of the support with a die coater, and dried at 80 ° C. to 120 ° C. (average 100 ° C.) for 4 minutes to give a second thermosetting resin. A composition layer was formed. The thickness of the second thermosetting resin composition layer was 30 μm. Next, the smooth surface side of a polypropylene film (“Alphan MA-411” manufactured by Oji Specialty Paper Co., Ltd., thickness 15 μm) as a protective film is bonded to the surface of the second thermosetting resin composition layer, 2 adhesive film 1 was prepared.

[Production Example 2]
(1) Preparation of resin varnish A resin varnish was prepared in the same manner as in Preparation Example 1.
(2) Production of first adhesive film 2 Copper foil (“3EC-III” manufactured by Mitsui Mining & Smelting Co., Ltd., thickness 18 μm) as a support, and PET film with an alkyd resin release layer (Lintec) as a protective film “AL5” (thickness: 38 μm) was prepared. The resin varnish prepared above is uniformly applied to the release layer side surface of the protective film with a die coater, and dried at 80 ° C. to 120 ° C. (average 100 ° C.) for 5 minutes to be a first thermosetting resin. A composition layer was formed. The thickness of the first thermosetting resin composition layer was 50 μm. Next, the matte surface side of the support was bonded to the surface of the first thermosetting resin composition layer to prepare a first adhesive film 2.
(3) Production of second adhesive film 2 Copper foil (“3EC-III” manufactured by Mitsui Mining & Smelting Co., Ltd., thickness 18 μm) as a support, PET film with an alkyd resin release layer (Lintec) as a protective film “AL5” (thickness: 38 μm) was prepared. The resin varnish prepared above is uniformly applied to the release layer side surface of the protective film with a die coater, and dried at 80 ° C. to 120 ° C. (average 100 ° C.) for 4 minutes to be a second thermosetting resin. A composition layer was formed. The thickness of the second thermosetting resin composition layer was 30 μm. Next, the second adhesive film 2 was prepared by bonding the mat surface side of the support to the surface of the second thermosetting resin composition layer.

<Example 1>
Evaluation substrates a, b, and c were produced using the first adhesive film 1 and the second adhesive film 1 according to the procedure of [Preparation of measurement / evaluation sample]. Each evaluation result is shown in 2.

<Example 2>
Evaluation substrates a, b, and c were produced using the first adhesive film 2 and the second adhesive film 2 according to the procedure of [Preparation of measurement / evaluation sample]. Each evaluation result is shown in 2.

<Example 3>
Evaluation substrates a, b, and c were produced using the first adhesive film 1 and the second adhesive film 1 according to the procedure of [Preparation of measurement / evaluation sample]. Each evaluation result is shown in Table 2.

<Comparative Example 1>
Evaluation substrates a, b, and c were produced using the first adhesive film 1 and the second adhesive film 1 according to the procedure of [Preparation of measurement / evaluation sample]. Each evaluation result is shown in 2.

<Comparative example 2>
Evaluation substrates a, b, and c were produced using the first adhesive film 1 and the second adhesive film 1 according to the procedure of [Preparation of measurement / evaluation sample]. Each evaluation result is shown in 2.

In Examples 1 to 3, which employ the step (B) of heat-treating the first thermosetting resin composition layer under predetermined conditions, a thin circuit board having a substrate thickness of 150 μm was used. However, it was confirmed that generation | occurrence | production of board | substrate curvature could be suppressed. In Examples 1 to 3, it was confirmed that the positional deviation of the components was also suppressed.
On the other hand, in Comparative Example 1, remarkable substrate warpage occurred, and the yield was remarkably reduced due to substrate conveyance failure (the minimum melt viscosity of the first thermosetting resin composition layer after the heat treatment is the upper limit of measurement ( 200,000 poise)). Further, in Comparative Example 2, it was confirmed that significant positional displacement of the parts occurred (the minimum melt viscosity of the first thermosetting resin composition layer after the heat treatment was 6,300).

DESCRIPTION OF SYMBOLS 1 Circuit board 2 Board | substrate 2a Cavity 3 Circuit wiring 4 Temporary attachment material 5 Parts 10 1st adhesive film 11 1st support body 12 1st thermosetting resin composition layer 12 '1st thermosetting resin composition Layer (heat-treated body)
12 '' first thermosetting resin composition layer (cured body)
20 2nd adhesive film 21 2nd support body 22 2nd thermosetting resin composition layer 22 '' 2nd thermosetting resin composition layer (cured body)
30 Horizontal surface 31 Fixing tool 50 Evaluation board b
100 Built-in circuit board

Claims (9)

The manufacturing method of the circuit board with a built-in component which contains the following process (A), (B), (C) and (D) in this order.
(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 first support body and a first support body on a circuit board on which a part is temporarily attached, the part including a temporary attachment material and a part temporarily attached with the temporary attachment material inside a cavity of the circuit board The first adhesive film including the first thermosetting resin composition layer having a minimum melt viscosity of 10,000 poise or less to be bonded to the first main surface of the circuit board is the first thermosetting resin composition layer. (B) heat-treating the first thermosetting resin composition layer to suppress positional displacement of the component in the following step (C), and the heat treatment Steps performed in a range where generation of substrate warpage is suppressed (C) Second circuit board The second adhesive film including the second support and the second thermosetting resin composition layer bonded to the second support is peeled off from the surface after the temporary attachment material is peeled off. (D) The process of thermosetting the 1st and 2nd thermosetting resin composition layer so that a heat-resistant resin composition layer may join to the 2nd main surface of a circuit board   The manufacturing method of the component built-in circuit board of Claim 1 whose minimum melt viscosity of the 1st thermosetting resin composition layer in a 1st adhesive film is 100-10000 poise.   The method for producing a circuit board with a built-in component according to claim 1 or 2, wherein in the step (B), the first thermosetting resin composition layer is heat-treated so that the minimum melt viscosity is 15,000 to 200,000 poise. .   The manufacturing method of the component built-in circuit board of any one of Claims 1-3 which heat-processes in the state with the 1st support body in a process (B).   The manufacturing method of the circuit board with a built-in component of any one of Claims 1-4 whose thickness of a circuit board is 50-350 micrometers.   The manufacturing method of the component built-in circuit board of any one of Claims 1-5 whose pitch between cavities is 1-10 mm.   The manufacturing method of the component built-in circuit board of any one of Claims 1-6 whose 2nd thermosetting resin composition layer is thinner than the 1st thermosetting resin composition layer.   When a test piece having a plane dimension of L (mm) × W (mm) (where L ≧ W and L is 550 mm or less) was obtained from the substrate obtained in the step (B), the test was performed. The method for manufacturing a component-embedded circuit board according to any one of claims 1 to 7, wherein the warpage of the piece is 0.1 L (mm) or less.   A semiconductor device comprising a component-embedded circuit board manufactured by the method according to claim 1.

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