JP7259889B2 - circuit board - Google Patents

Description

TECHNICAL FIELD The present invention relates to a circuit board, a resin composition used as a material for an insulating layer of the circuit board, and an adhesive film formed using the resin composition.

Circuit boards widely used in electronic devices are required to have finer wiring and higher density in order to reduce the size and increase the functionality of the electronic devices. As a structure of a circuit board, particularly a circuit board (high-frequency circuit board) on which a high-frequency device is mounted, an insulating layer is provided on at least one main surface of a core substrate (inner layer substrate), and a conductor layer (wiring) is provided on the insulating layer. is provided. Also known is a high-frequency circuit board having a multilayer wiring structure in which a plurality of insulating layers and conductor layers are provided on one main surface of a core substrate. As a method for manufacturing a high-frequency circuit board having such a multilayer wiring structure, a build-up method is used in which insulating layers and conductor layers are alternately formed on the main surface of a core substrate and these layers are stacked to form a multilayer wiring structure. Manufacturing methods are known.

In the method for producing a high-frequency circuit board by a build-up method, the insulating layer is formed by, for example, using a resin composition layer with a support (adhesive film) containing a support and a resin composition layer, and attaching the resin composition layer to the core substrate. It can be formed by laminating and thermally curing the resin composition layer. Then, via holes can be formed by drilling the formed insulating layer (see Patent Document 1, for example).

One of the causes of attenuation of electrical signals in circuit boards is that the dielectric constant of the insulating layer is high. In order to suppress the attenuation of electrical signals due to the high dielectric constant of the insulating layer, it is required to make the dielectric constant smaller.

In high-frequency circuit boards that transmit high-frequency electrical signals, the high dielectric constant of the insulating layer used to form the high-frequency circuit causes significant transmission loss. In particular, it is required to further reduce the dielectric constant of the insulating layer for forming high frequency circuits.

JP-A-2016-35969

A high-frequency circuit board is manufactured using an inner layer board such as a glass epoxy board, which is relatively inexpensive and has a relatively high dielectric constant, in order to reduce costs while ensuring electrical characteristics.

However, in such a conventional high-frequency circuit board, if the dielectric constant of the insulating layer for forming a high-frequency circuit is to be made smaller in view of the required electrical properties, the adhesion of the insulating layer for forming a high-frequency circuit to the inner layer substrate must be ensured. In some cases, the insulating layer for forming the high-frequency circuit is peeled off from the inner layer substrate.

As a result, the reliability of a device (semiconductor device) having such a high-frequency circuit board may be impaired.

Therefore, in a high-frequency circuit board using a relatively inexpensive inner layer substrate, it is possible to further reduce the dielectric constant of the high-frequency circuit-forming insulating layer and to ensure high adhesion of the high-frequency circuit-forming insulating layer to the inner layer substrate. Therefore, there is a demand for a high-frequency circuit board with improved reliability.

The present invention has been made in view of the above problems. As a result of intensive studies on the above problems, the inventors of the present invention have found that the above problems can be solved by a high-frequency circuit board adopting a predetermined configuration, and have completed the present invention.

That is, the present invention provides the following [1] to [16].
[1] an inner layer substrate;
A high frequency circuit board comprising a high frequency circuit forming insulating layer bonded to the inner layer substrate,
When Dk(A) is the dielectric constant of the inner layer substrate and Dk(B) is the dielectric constant of the insulating layer for forming a high-frequency circuit, Dk(A) and Dk(B) are represented by the following formula:
Dk(B)≦Dk(A)−0.8
and a peel strength of the insulating layer for forming a high frequency circuit with respect to the inner layer substrate is 0.5 kgf/cm or more.
[2] In [1], wherein only one insulating layer for forming a high-frequency circuit is provided, or two or more insulating layers for forming a high-frequency circuit are provided on one main surface side of the inner layer substrate. A high-frequency circuit board as described.
[3] The high-frequency circuit board according to [1] or [2], wherein the insulating layer for forming a high-frequency circuit has a thickness of 20 to 200 μm.
[4] The high-frequency circuit board according to any one of [1] to [3], wherein the inner layer board has a thickness of 50 to 4000 μm.
[5] The inner layer substrate includes a glass epoxy substrate, and the insulating layer for forming a high-frequency circuit bonded to the glass epoxy substrate is a cured body obtained by thermosetting a resin composition containing component (A) an epoxy resin. , the high-frequency circuit board according to any one of [1] to [4].
[6] The inner substrate includes one or more insulating layers obtained by curing a material containing an epoxy resin, and the insulating layer for forming a high-frequency circuit is bonded to the insulating layer, and the insulating layer for forming a high-frequency circuit is: The high-frequency circuit board according to any one of [1] to [5], which is a cured product obtained by thermosetting a resin composition containing component (A) an epoxy resin.
[7] The high-frequency circuit board according to [5] or [6], wherein the resin composition further contains component (B) a curing agent and component (C) an inorganic filler.
[8] The high-frequency circuit board according to [7], wherein the resin composition further contains component (D) an organic filler.
[9] The component (D) organic filler is one or more organic fillers selected from the group consisting of cycloolefin polymer particles, polyphenylene ether particles, polystyrene particles, and fluoropolymer particles, [8] The high-frequency circuit board according to .
[10] The high-frequency circuit board according to [9], wherein the component (D) organic filler is fluorine polymer particles.
[11] The high-frequency circuit board according to [9] or [10], wherein the resin composition further contains component (E) a resin having a vinyl group.
[12] The high-frequency circuit board according to any one of [9] to [11], wherein the resin composition further contains component (F) an indene cumarone resin.
[13] The high-frequency circuit board according to [12], wherein the resin composition further contains component (H) a silane compound.
[14] The high-frequency circuit board according to any one of [1] to [13], wherein Dk(A) is 4.0 or more.
[15] The high-frequency circuit board according to any one of [1] to [14], wherein Dk(B) is 3.5 or less.
[16] The high-frequency circuit board according to [15], wherein the Dk(B) is 3.0 or less.

According to the present invention, in a high-frequency circuit board using a relatively inexpensive inner-layer substrate, the dielectric constant of the high-frequency circuit-forming insulating layer further formed on the inner-layer substrate can be made smaller, and high adhesion to the inner-layer substrate can be achieved. It is possible to provide a highly reliable high-frequency circuit board having an insulating layer for forming a high-frequency circuit having good properties.

FIG. 1 is a schematic diagram for explaining the configuration of the high-frequency circuit board of the first embodiment. FIG. 2 is a schematic diagram for explaining the configuration of the high-frequency circuit board of the second embodiment. FIG. 3 is a schematic diagram for explaining the configuration of the high-frequency circuit board of the third embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. It should be noted that the drawings only schematically show the shape, size and arrangement of the constituent elements to the extent that the invention can be understood. The present invention is not limited by the following description, and each component can be changed as appropriate without departing from the gist of the present invention. In the drawings used for the following description, the same components are denoted by the same reference numerals, and redundant description may be omitted. Also, configurations according to embodiments of the present invention are not necessarily manufactured or used in the arrangement shown.

[High frequency circuit board]
As described above, the high-frequency circuit board of the present invention is a high-frequency circuit board comprising an inner layer substrate and an insulating layer for forming a high frequency circuit bonded to the inner layer substrate, wherein the dielectric constant of the inner layer substrate is Dk (A) and Dk(A) and Dk(B) satisfy the formula: Dk(B)≦Dk(A)−0.8, and A high-frequency circuit board, wherein the peel strength of the insulating layer for high-frequency circuit formation with respect to the inner layer board is 0.5 kgf/cm or more.

Here, the term "high-frequency circuit board" means a circuit board that can operate even with electrical signals in a high-frequency band. Here, "high frequency band" means a band of 1 GHz or higher. The high-frequency circuit board of the present invention can operate effectively even with an electric signal in a band of 28 GHz to 80 GHz.

First, the inner layer board and the insulating layer for forming the high frequency circuit provided on the inner layer board, which are provided in the high frequency circuit board, will be described.

<Inner layer substrate>
The inner layer substrate includes core substrates such as, for example, glass epoxy substrates, metal substrates, polyester substrates, polyimide substrates, BT resin substrates, and thermosetting polyphenylene ether substrates. Also, the inner layer substrate may be the core substrate itself. A conductor layer (semiconductor layer) may be provided directly on one side or both sides of the first main surface and the second main surface facing each other of the core substrate. It may be provided on an insulating layer provided on the surface and/or the second main surface. The inner layer substrate may have a multilayer structure in which two or more insulating layers and/or conductor layers are laminated. The inner layer substrate includes a multilayer substrate in which two or more conductor layers are electrically connected to each other by wiring provided in via holes or through holes. The innerlayer substrate may comprise any suitable further components such as passive elements.

As the core substrate, a glass epoxy substrate, a BT resin substrate, or a thermosetting polyphenylene ether substrate is preferable from the viewpoint of electrical properties, availability, cost, etc., and a glass epoxy substrate is particularly preferable. An example of the glass epoxy substrate that can be suitably used for the high-frequency circuit substrate is "R-1766" manufactured by Panasonic Electric Works Co., Ltd. Further, as an example of the inner layer substrate which is a multilayer substrate that can be suitably used for the high frequency circuit substrate, there is “R-1661” manufactured by Panasonic Electric Works Co., Ltd.

The thickness of the inner layer substrate that can be used for the high-frequency circuit board is usually 50 μm to 4000 μm, and from the viewpoint of improving the mechanical strength and reducing the height (thickness reduction) of the high-frequency circuit board, it is preferably 200 μm to 200 μm. 3200 μm.

<Insulating layer for high frequency circuit formation>
The insulating layer for forming a high-frequency circuit on the high-frequency circuit board is a layer of a cured product obtained by thermally curing a resin composition, which will be described later. An insulating layer for forming a high-frequency circuit made of such a cured product is particularly suitable for use as an insulating layer for a high-frequency circuit board. In the insulating layer for forming a high-frequency circuit, not only the already-described wiring for forming a high-frequency circuit for transmitting electrical signals in a high-frequency band but also wiring for transmitting electrical signals in a lower frequency band are mixedly provided. can also

In the high-frequency circuit board, the high-frequency circuit forming insulating layer may be provided with only one layer on the inner layer board, or may be provided with two or more layers. When two or more insulating layers are provided, they can be provided as build-up layers in which conductor layers (wiring layers) and high-frequency circuit-forming insulating layers are alternately laminated. In particular, when a glass epoxy substrate such as "R-1766" is used as the core substrate, two or more high-frequency circuit insulating layers may be provided on one main surface side of the core substrate.

As described above, the inner layer substrate that the high-frequency circuit board of the present invention can have can have various configurations. Here, a specific arrangement relationship between the high-frequency circuit forming insulating layer and the inner layer substrate will be described. (i) When the inner layer substrate is the core substrate itself, the high-frequency circuit insulating layer is directly bonded to the main surface of the core substrate. (ii) When the inner layer substrate includes a core substrate and a conductor layer provided on the main surface of the core substrate, the high-frequency circuit insulating layer is bonded to the main surface of the core substrate and the conductor layer. (iii) When the inner layer substrate includes a core substrate and an insulating layer provided on the main surface of the core substrate, the high-frequency circuit insulating layer is bonded to the insulating layer. (iv) When the inner substrate comprises a core substrate, an insulating layer provided on the main surface of the core substrate, and a conductive layer provided on the insulating layer, the high-frequency circuit insulating layer is bonded to the insulating layer and the conductive layer. do.

The thickness of the insulating layer applied to the high frequency circuit board is usually 20 μm to 200 μm, preferably 50 μm to 150 μm from the viewpoint of improving electrical characteristics and reducing the height of the high frequency circuit board.

The insulating layer is one for electrically connecting the conductor layer provided in the inner layer substrate and the conductor layer provided in the insulating layer, or for electrically connecting the conductor layers provided in two or more insulating layers. It may have one or more via holes.

It is preferable that the dielectric constant Dk(B) of the insulating layer over the high-frequency circuit board is lower. Dk(B) is preferably 3.5 or less, more preferably 3.3 or less, and even more preferably 3.0 or less from the viewpoint of reducing the transmission loss of high-frequency electrical signals. . The dielectric constant can usually be 2 or more. The dielectric constant can be measured according to the method described in <Evaluation of dielectric constant> below.

As described above, when Dk(A) is the dielectric constant of the inner layer substrate, Dk(A) and Dk(B) preferably satisfy the formula: Dk(B)≦Dk(A)−0.8. Here, the dielectric constant of the inner layer substrate means a value measured in a mode in which conductor layers (wiring layers) that the inner layer substrate may have are removed from both sides of the inner layer substrate.

The material of the inner layer substrate, that is, the material of the core substrate to which the high-frequency circuit insulating layer is bonded, and the material of the insulating layer to which the high-frequency circuit insulating layer is bonded among the insulating layers that the inner layer substrate can have are selected so as to satisfy the above formula. However, if the material of the resin composition for forming the high-frequency circuit insulating layer is selected, the transmission loss of high-frequency electrical signals can be further reduced.

Dk(A) is not particularly limited. Dk(A) is preferably 4.0 or more from the viewpoint of cost and availability.

The insulating layer for high frequency circuits preferably exhibits a lower dielectric loss tangent. The dielectric loss tangent is preferably 0.010 or less, more preferably 0.009 or less, more preferably 0.008 or less, from the viewpoint of preventing heat generation during transmission of high-frequency signals and reducing signal delay and signal noise. It is more preferably 0.007 or less, 0.006 or less, or 0.005 or less. The dielectric loss tangent can usually be 0.001 or more.

The high-frequency circuit insulating layer exhibits good adhesion to the inner layer substrate, that is, the core substrate and the insulating layer of the inner layer substrate. The peel strength to the inner layer substrate is preferably 0.4 kgf/cm or more, more preferably 0.5 kgf/cm or more, and still more preferably 0.6 kgf/cm or more. Evaluation of the peel strength with respect to the inner layer substrate can be measured according to the method described in [Measurement of Peel Strength] described later.

The high-frequency circuit insulating layer also exhibits good adhesion to the conductor layer of the inner layer substrate, that is, exhibits excellent peel strength to the conductor layer. The peel strength to the conductor layer is preferably 0.4 kgf/cm or more, more preferably 0.5 kgf/cm or more, and still more preferably 0.6 kgf/cm or more. Evaluation of the peel strength with respect to the conductor layer can be measured according to the method described in [Measurement of Peel Strength] described later.

Here, an example of the configuration of the high-frequency circuit board of the present invention will be described with reference to FIGS. 1, 2 and 3. FIG.

First, a configuration example of a high-frequency circuit board according to the first embodiment will be described with reference to FIG. FIG. 1 is a schematic diagram for explaining the configuration of the high-frequency circuit board according to the first embodiment.

As shown in FIG. 1, the high frequency circuit board 10 of the first embodiment includes a core board 22 which is an inner layer board 20 . The core substrate 22 has a first major surface 22a (20a) and a second major surface 22b (20b) facing each other.

A high-frequency circuit insulating layer 30 is provided on the first main surface 22a so as to be bonded to and cover the core substrate 22 . A high-frequency circuit conductor layer (wiring layer) 40 is provided on the surface of the high-frequency circuit insulating layer 30 . The high-frequency circuit conductor layer 40 may include not only wiring for configuring a high-frequency circuit for transmitting electrical signals in a high-frequency band, but also wiring for transmitting electrical signals in a lower frequency band. good.

An insulating layer 50 is provided on the second main surface 22b so as to be bonded thereto. A conductor layer (wiring layer) 60 is provided on the surface of the insulating layer 50 .

Further, in this configuration example, a through-hole 12 is provided to pass through the inner layer substrate 20, that is, the core substrate 22, the high-frequency circuit insulating layer 30, and the insulating layer 50 in the thickness direction. A through-hole wiring 12 a is provided in the through-hole 12 . In this configuration example, a portion of the high-frequency circuit conductor layer 40 and a portion of the conductor layer 60 are electrically connected by the through-hole wiring 12a.

Next, a configuration example of the high-frequency circuit board according to the second embodiment will be described with reference to FIG. FIG. 2 is a schematic diagram for explaining the configuration of the high-frequency circuit board according to the second embodiment.

As shown in FIG. 2, the high frequency circuit board 10 of the second embodiment includes an inner layer board 20. As shown in FIG. In this configuration example, the inner layer substrate 20 includes a core substrate 22 , a first conductor layer (wiring layer) 24 and a second conductor layer (wiring layer) 26 . Here, the first conductor layer 24 is provided on the first major surface 22 a of the core substrate 22 , that is, the first major surface 20 a of the inner layer substrate 20 . The second conductor layer 26 is provided on the second main surface 22 b of the core substrate 22 , that is, on the second main surface 20 b of the inner layer substrate 20 .

The first main surface 22a on which the first conductor layer 24 is provided is bonded to and covers the core substrate 22 and the first conductor layer 24, that is, to be bonded to the first main surface 20a of the inner layer substrate 20. A high-frequency circuit insulating layer 30 is provided on the upper surface of the substrate. A high-frequency circuit conductor layer 40 is provided on the surface of the high-frequency circuit insulating layer 30 .

The high-frequency circuit insulating layer 30 is provided with a via hole 32 that penetrates the high-frequency circuit insulating layer 30 in the thickness direction. A via-hole wiring 32 a is provided in the via hole 32 . In this configuration example, a portion of the high-frequency circuit wiring 40 and a portion of the first conductor layer 24 are electrically connected by an in-via-hole wiring 32a.

On the second main surface 22b provided with the second conductor layer 26, an insulating layer 50 is bonded to the core substrate 22 and the second conductor layer 26, that is, to the second main surface 20b of the inner layer substrate 20 so as to cover them. is provided. A conductor layer 60 is provided on the surface of the insulating layer 50 .

The low-frequency circuit insulating layer 50 is provided with a via hole 52 penetrating through the low-frequency circuit insulating layer 50 in the thickness direction. In the via hole 52, an in-via-hole wiring 52a is provided. In this configuration example, a portion of the low-frequency circuit conductor layer 60 and a portion of the second conductor layer 26 are electrically connected by an in-via-hole wiring 52a.

Further, in this configuration example, a through hole 12 is provided that passes through the core substrate 22, the high-frequency circuit insulating layer 30, and the insulating layer 50 in the thickness direction. A through-hole wiring 12 a is provided in the through-hole 12 .

Next, a configuration example of a high-frequency circuit board according to a third embodiment will be described with reference to FIG. FIG. 3 is a schematic diagram for explaining the configuration of the high-frequency circuit board according to the third embodiment.

As shown in FIG. 3, the high frequency circuit board 10 of the third embodiment includes an inner layer board 20. As shown in FIG. In this configuration example, the inner layer substrate 20 includes a core substrate 22 , a first conductor layer 24 , a second conductor layer 26 , an interlayer insulating layer 27 and a third conductor layer (wiring layer) 28 . Here, the first conductor layer 24 is provided on the first main surface 22 a of the core substrate 22 . The second conductor layer 26 is provided on the second main surface 22 b of the core substrate 22 . The interlayer insulating layer 27 is provided so as to be bonded to and cover the core substrate 22 and the first conductor layer 24 . The third conductor layer 28 is provided so as to be bonded to the interlayer insulating layer 27 .

The high-frequency circuit insulating layer 30 is provided so as to be bonded to the interlayer insulating layer 27 and the third conductor layer 28 and cover them, that is, so as to be bonded to the first main surface 20 a of the inner layer substrate 20 . A high-frequency circuit conductor layer 40 is provided on the surface of the high-frequency circuit insulating layer 30 .

A via hole 29 is provided in the interlayer insulating layer 27 so as to penetrate the interlayer insulating layer 27 in the thickness direction. A via-hole wiring 29 a is provided in the via hole 29 . In this configuration example, a portion of the high-frequency circuit wiring 40 and a portion of the third conductor layer 28 are electrically connected by the via-hole wiring 29a.

An insulating layer 50 is provided on the second main surface 22b on which the second conductor layer 26 is provided, that is, on the second main surface 20b of the inner layer substrate 20 so as to be bonded thereto. A conductor layer 60 is provided on the surface of the insulating layer 50 .

The insulating layer 50 is provided with a via hole 52 penetrating through the insulating layer 50 in the thickness direction. In the via hole 52, an in-via-hole wiring 52a is provided. In this configuration example, a portion of the conductor layer 60 and a portion of the second conductor layer 26 are electrically connected by an in-via-hole wiring 52a.

Further, in this configuration example, a through hole 12 is provided to pass through the core substrate 22, the interlayer insulating layer 27, the high-frequency circuit insulating layer 30, and the insulating layer 50 in the thickness direction. A through-hole wiring 12 a is provided in the through-hole 12 .

[Method for manufacturing high-frequency circuit board]
Next, a method for manufacturing a high frequency circuit board will be described. First, the adhesive film used in this manufacturing method will be described.

<Adhesive film>
The adhesive film comprises a support and a resin composition layer provided on the support and containing a resin composition described below.

Support The support includes, for example, a film made of a plastic material, a metal foil, and a release paper. The support is preferably a film made of a plastic material or a metal foil.

When a film made of a plastic material is used as the support, the plastic material includes, for example, polyethylene terephthalate (hereinafter sometimes referred to as "PET"), polyethylene naphthalate (hereinafter sometimes referred to as "PEN"), and the like. Polyester, polycarbonate (hereinafter sometimes referred to as "PC"), acrylic polymers such as polymethyl methacrylate (PMMA), cyclic polyolefin, triacetyl cellulose (TAC), polyether sulfide (PES), polyether ketone, polyimide be done. Among them, polyethylene terephthalate and polyethylene naphthalate are preferred, and polyethylene terephthalate is particularly preferred because it is inexpensive and readily available.

When a metal foil is used as the support, examples of the metal foil include copper foil and aluminum foil, with copper foil being preferred. As the copper foil, a foil made of only copper may be used, or a foil made of a copper alloy of copper and other metals (e.g., tin, chromium, silver, magnesium, nickel, zirconium, silicon, titanium, etc.) may be used. may

The support may be subjected to matte treatment, corona treatment, or antistatic treatment on the side to be bonded to the resin composition layer.

Further, as the support, a support with a release layer having a release layer on the surface to be bonded to the resin composition layer may be used. The release agent that can be used in the release layer of the release layer-attached support includes, for example, one or more release agents selected from the group consisting of alkyd resins, polyolefin resins, urethane resins, and silicone resins. is mentioned. As the support with a release layer, a commercially available product may be used. For example, "SK-1" manufactured by Lintec Co., Ltd., which is a PET film having a release layer containing an alkyd resin release agent as a main component. , “AL-5”, “AL-7”, “Lumirror T6AM” manufactured by Toray Industries, Inc., and the like.

The thickness of the support is not particularly limited. The thickness of the support is preferably in the range of 5 μm to 75 μm, more preferably in the range of 10 μm to 60 μm. When a release layer-attached support is used, the thickness of the release layer-attached support as a whole is preferably within the above range.

Resin Composition Layer The resin composition layer included in the adhesive film is a thin film obtained by semi-curing a coating film of resin varnish. For the adhesive film, for example, a resin varnish is prepared by dissolving a resin composition in an organic solvent. It can be manufactured by using a monolayer.

Examples of the organic solvent used for forming the resin composition layer include ketones such as acetone, methyl ethyl ketone (MEK) and cyclohexanone, ethyl acetate, butyl acetate, cellosolve acetate, acetic acid such as propylene glycol monomethyl ether acetate and carbitol acetate. Examples include esters, carbitols such as cellosolve and butyl carbitol, aromatic hydrocarbons such as toluene and xylene, and amide solvents such as dimethylformamide, dimethylacetamide (DMAc) and N-methylpyrrolidone. An organic solvent may be used individually by 1 type, and may be used in combination of 2 or more type.

The coating film of the resin varnish can be dried by a known method such as heating or blowing hot air. The drying conditions are not particularly limited, but the resin composition layer is dried so that the content of the organic solvent is 10% by mass or less, preferably 5% by mass or less. Depending on the boiling point of the organic solvent in the resin varnish, for example, when using a resin varnish containing 30% by mass to 60% by mass of the organic solvent, the coating film of the resin varnish is heated at 50° C. to 150° C. for 3 minutes to 10 minutes. A resin composition layer can be formed by drying.

In the adhesive film, a protective film conforming to the support may be further laminated on the side of the resin composition layer that is not bonded to the support (the side opposite to the support). can. The thickness of the protective film is not particularly limited. The thickness of the protective film is, for example, 1 μm to 40 μm. By laminating the protective film, it is possible to prevent the surface of the resin composition layer from being dusty or scratched. The adhesive film can be wound into a roll and stored. When the adhesive film has a protective film, it can be used by peeling and removing the protective film.

The minimum melt viscosity of the resin composition layer (or resin composition) in the adhesive film is preferably 1000 poise or more from the viewpoint of stably maintaining the thickness of the resin composition layer even if the layer is thin. , 1500 poise or more, and more preferably 2000 poise or more. The minimum melt viscosity of the resin composition layer is preferably 12,000 poise or less, more preferably 10,000 poise or less, even more preferably 8,000 poise or less, and particularly preferably, from the viewpoint of improving circuit embedding properties. 5000 poise or less.

The term “minimum melt viscosity of the resin composition layer” refers to the minimum viscosity exhibited when the resin composition layer melts. Specifically, when the resin composition layer is heated and melted at a constant rate of temperature rise, the melt viscosity initially decreases as the temperature rises, and then the melt viscosity rises as the temperature rises over a certain amount of time. . The lowest melt viscosity is the melt viscosity at the minimum point where the melt viscosity is the lowest. The minimum melt viscosity of the resin composition layer can be measured by a dynamic viscoelasticity method.

<Prepreg>
The insulating layer on the high-frequency circuit board may be formed using a prepreg instead of the already-described adhesive film. A prepreg can be formed by impregnating a sheet-like fiber base material with a resin composition described below.
The prepreg may contain only one sheet-like fiber base material, or may contain two or more sheet-like fiber base materials.

The material of the sheet-like fiber base material used for the prepreg is not particularly limited. As the sheet-like fiber base material, those commonly used as prepreg base materials such as glass cloth, aramid nonwoven fabric, and liquid crystal polymer nonwoven fabric can be used. From the viewpoint of thinning the high-frequency circuit board, the thickness of the sheet-like fiber base material is preferably 200 μm or less, more preferably 150 μm or less, still more preferably 120 μm or less, and even more preferably 100 μm or less. be. It is preferably 800 μm or less, more preferably 70 μm or less, and even more preferably 60 μm or less, because it is possible to keep the depth of the plating recessed for forming the conductor layer small. The thickness of the sheet-like fiber base material is usually 4 μm or more, 6 μm or more, or 8 μm or more. When the prepreg is referred to as a "non-volatile component", the "sheet-like fiber base material" is not included in the "non-volatile component".

A prepreg can be manufactured by a known method such as a hot melt method or a solvent method.

The thickness of the prepreg can be in the same range as the resin composition layer in the adhesive film described above.

A high-frequency circuit board can be manufactured using an adhesive film by a manufacturing method including the following steps (I) and (II).
Step (I) A step of laminating an adhesive film on an inner layer substrate so that the resin composition layer of the adhesive film is bonded to the inner layer substrate Step (II) A step of thermally curing the resin composition layer to form an insulating layer

Lamination of the adhesive film on the inner layer substrate can be carried out, for example, by a thermocompression bonding process in which the adhesive film is pressed against the inner layer substrate from the support side and heated. Examples of the members used in the thermocompression bonding process (also referred to as “thermocompression members”) include heated metal plates (such as SUS end plates) and metal rolls (SUS rolls). Instead of pressing the thermocompression member directly against the support of the adhesive film, an elastic material such as heat-resistant rubber is interposed so that the adhesive film can sufficiently follow the unevenness of the main surface of the inner layer substrate. It is preferable to press with

Lamination of the inner layer substrate and the adhesive film can be carried out by a vacuum lamination method. In the vacuum lamination method, the temperature for thermocompression bonding is preferably in the range of 60°C to 160°C, more preferably in the range of 80°C to 140°C. The pressure of thermocompression bonding is preferably in the range of 0.098 MPa to 1.77 MPa, more preferably in the range of 0.29 MPa to 1.47 MPa, and the time of thermocompression bonding is preferably in the range of 20 seconds to 400 seconds. and more preferably in the range of 30 seconds to 300 seconds. Lamination is preferably carried out under reduced pressure conditions of 26.7 hPa or less.

Lamination can be done with a commercially available vacuum laminator. Commercially available vacuum laminators include, for example, a vacuum pressurized laminator manufactured by Meiki Seisakusho Co., Ltd. and a vacuum applicator manufactured by Nikko Materials Co., Ltd.

After lamination, the laminated resin composition layer may be subjected to a smoothing treatment under normal pressure (atmospheric pressure), for example, by further pressing from the support side with a thermocompression member. The pressing conditions for the smoothing treatment can be the same as the conditions for the thermocompression bonding of the lamination. Smoothing treatment can be performed with a commercially available laminator. The lamination and smoothing treatment may be performed continuously using the above-mentioned commercially available vacuum laminator.

The support may be removed between steps (I) and (II) or after step (II).

In step (II), the laminated (and smoothed) resin composition layer is thermally cured to form an insulating layer.

The conditions for thermosetting the resin composition layer are not particularly limited, and the conditions usually employed when forming the insulating layer of the high-frequency circuit board can be employed.

The thermosetting conditions for the resin composition layer are, for example, a curing temperature in the range of 120° C. to 240° C. (preferably 150° C. to 220° C., more preferably 170° C. to 200° C.) and a curing time of 5° C. minutes to 120 minutes (preferably 10 minutes to 100 minutes, more preferably 15 minutes to 90 minutes).

Before thermosetting the resin composition layer, the resin composition layer may be preheated at a temperature lower than the curing temperature. For example, prior to thermosetting the resin composition layer, the resin composition layer is cured 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). Preheating may be performed for 5 minutes or more (preferably 5 minutes to 150 minutes, more preferably 15 minutes to 120 minutes).

When manufacturing a high-frequency circuit board, any one of (III) the step of drilling holes in the insulating layer, (IV) the step of roughening the insulating layer, and (V) the step of forming a conductor layer is further carried out. may These steps (III) to (V) can be carried out according to various methods known to those skilled in the art that are used in the manufacture of high frequency circuit boards. When the support is removed after step (II), the support may be removed between step (II) and step (III), between step (III) and step (IV), or It can be carried out between (IV) and step (V).

In another embodiment, the insulating layer of the high-frequency circuit board of the present invention may be formed using the already-described prepreg instead of the adhesive film. Formation of the insulating layer using the prepreg can be basically carried out by the same process as in the case of using the adhesive film.

Step (III) is a step of making holes in the insulating layer, whereby holes such as via holes and through holes can be formed in the insulating layer. Step (III) may be performed using, for example, a drill, laser, plasma, or the like, depending on the composition of the resin composition used to form the insulating layer. The dimensions and shape of the holes may be appropriately determined according to the design of the high-frequency circuit board.

Step (IV) is a step of roughening the insulating layer. The procedure and conditions of the roughening treatment are not particularly limited, and known procedures and conditions that are commonly used for forming an insulating layer of a high-frequency circuit board can be employed. For example, the insulating layer can be roughened by performing a swelling treatment with a swelling liquid, a roughening treatment with an oxidizing agent, and a neutralizing treatment with a neutralizing liquid in this order. The swelling liquid is not particularly limited. Examples of swelling liquids include alkaline solutions and surfactant solutions. The swelling liquid is preferably an alkaline solution, more preferably a sodium hydroxide solution or a potassium hydroxide solution. Examples of commercially available swelling liquids include "Swelling Dip Securigans P" and "Swelling Dip Securigans SBU" manufactured by Atotech Japan Co., Ltd. The swelling treatment with the swelling liquid is not particularly limited. The swelling treatment can be performed, for example, by immersing the insulating layer in a swelling liquid at 30° C. to 90° C. for 1 minute to 20 minutes. From the viewpoint of suppressing the swelling of the resin of the insulating layer to an appropriate level, it is preferable to immerse the insulating layer in a swelling liquid at 40° C. to 80° C. for 5 minutes to 15 minutes. The oxidizing agent is not particularly limited. Examples of the oxidizing agent include an alkaline permanganate solution in which potassium permanganate or sodium permanganate is dissolved in an aqueous solution of sodium hydroxide. The roughening treatment with an oxidizing agent such as an alkaline permanganate solution is preferably carried out by immersing the insulating layer in an oxidizing agent solution heated to 60° C. to 80° C. for 10 to 30 minutes. Further, the permanganate concentration 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 CP" and "Dosing Solution Securigans P" manufactured by Atotech Japan. Moreover, as a neutralization liquid, an acidic aqueous solution is preferable. Examples of commercially available neutralizing liquids include "Reduction Solution Securigant P" manufactured by Atotech Japan Co., Ltd. The treatment with the neutralizing solution can be performed by immersing the treated surface of the insulating layer roughened with the oxidizing agent in the neutralizing solution at 30° C. to 80° C. for 5 to 30 minutes. From the viewpoint of workability, etc., it is preferable to immerse the insulating layer roughened with an oxidizing agent in a neutralizing solution at 40° C. to 70° C. for 5 to 20 minutes.

In one embodiment, the arithmetic mean roughness (Ra) of the surface of the insulating layer after the roughening treatment is preferably 280 nm or less, more preferably 250 nm or less, still more preferably 200 nm or less, 140 nm or less, 130 nm or less, 120 nm or less, 110 nm or less, 100 nm or less, 95 nm or less, or 90 nm or less. The Ra value is preferably 0.5 nm or more, more preferably 1 nm or more. The arithmetic mean roughness (Ra) of the surface of the insulating layer can be measured using a non-contact surface roughness meter. A specific example of the non-contact surface roughness meter is "WYKO NT3300" manufactured by Beecoinstruments.

Step (V) is a step of forming a conductor layer.

The material used for the conductor layer is not particularly limited. In a preferred embodiment, the conductor layer contains 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, and the alloy layer may be, for example, an alloy of two or more metals selected from the above group (for example, a nickel-chromium alloy, a copper- nickel alloys and copper-titanium alloys). Among them, from the viewpoint of versatility, cost, ease of patterning, etc. of the formation of the conductor layer, a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or a nickel-chromium alloy, copper・A nickel alloy or copper-titanium alloy alloy layer is preferable, and a single metal layer of chromium, nickel, titanium, aluminum, zinc, gold, palladium, silver or copper, or a nickel-chromium alloy alloy layer is more preferable. A single metal layer is more preferred.

The conductor layer may have a single-layer structure or a multi-layer structure in which two or more single metal layers or alloy layers made of different kinds 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 usually 3 μm to 200 μm, preferably 10 μm to 100 μm.

In one embodiment, the conductor layer can be formed by plating. For example, a conductive layer having a desired wiring pattern can be formed by plating the surface of the insulating layer by a conventionally known method such as a semi-additive method, a modified-semi-additive method, or a full-additive method. An example of forming a conductor layer by a modified-semi-additive method will be described below.

First, a layer of copper foil is formed on the surface of the insulating layer. As the copper foil layer, for example, the copper foil used as the support of the adhesive film may be used as it is, or the copper foil may be used after being made thinner by, for example, an etching process. Next, using the copper foil layer as a seed layer, a mask pattern is formed to expose a portion of the seed layer so as to correspond to the desired wiring pattern. After forming a metal layer on the exposed seed layer by electroplating, the mask pattern is removed. After that, the unnecessary seed layer is removed by etching or the like, and a conductor layer having a desired wiring pattern can be formed.

In the case where the high-frequency circuit board has two or more high-frequency circuit insulating layers and wiring layers (build-up layers), the already described high-frequency circuit insulating layer forming step and conductor layer forming step are further repeated one or more times. A high-frequency circuit board having a multi-layer wiring structure capable of functioning as a high-frequency circuit can be manufactured by carrying out the above steps.

[Resin composition]
The resin composition that can be suitably used for forming the adhesive film and the prepreg for manufacturing the high-frequency circuit board of the present invention is described below.

The components of the resin composition for forming the insulating layer for high-frequency circuits are selected from the viewpoint of increasing the adhesion (peel strength) of the insulating layer for high-frequency circuits, which is a cured product of the resin composition, to the inner-layer substrate. Considering the material, it is preferable to select a material that has a structure similar to that of the material of the inner layer substrate and similar properties (for example, magnitude of polarity).

For example, the core substrate that is bonded to the high-frequency circuit insulating layer contains epoxy resin as a material such as a glass epoxy substrate, and/or the insulating layer of the inner layer substrate that is bonded to the high-frequency circuit insulating layer contains epoxy resin. When it is included, the resin composition preferably includes component (A) epoxy resin, and for example, when the core substrate to be bonded to the insulating layer for high frequency circuits is a BT resin substrate and / or the insulation provided by the inner layer substrate When the insulating layer that is a layer and is bonded to the insulating layer for high-frequency circuits contains a resin having a carbodiimide group or a resin having a triazine skeleton, the resin composition contains a resin having a carbodiimide group or a resin having a triazine skeleton. Further, when the core substrate bonded to the insulating layer for high-frequency circuits is a polyphenylene ether substrate and/or the insulating layer included in the inner layer substrate and bonded to the insulating layer for high-frequency circuits has a polyphenylene ether skeleton. When resin is included, the resin composition preferably includes a resin having a polyphenylene ether skeleton.

By selecting the resin composition in this manner, it is possible to ensure the adhesion of the high-frequency circuit insulating layer to the inner layer substrate even when an inexpensive and readily available inner layer substrate is used.

<Component (A) epoxy resin>
The resin composition may contain component (A) an epoxy resin. Examples of epoxy resins include bixylenol type epoxy resin, 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 novolak type epoxy resin, tert-butyl-catechol type epoxy resin, naphthalene type epoxy resin, naphthol type epoxy resin, anthracene type epoxy resin, glycidylamine type epoxy resin, glycidyl ester type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, linear aliphatic epoxy resin, epoxy resin having a butadiene structure, alicyclic epoxy resin, heterocyclic epoxy resin, spiro ring-containing epoxy resin, cyclohexanedimethanol type epoxy resin, naphthylene Ether-type epoxy resins, trimethylol-type epoxy resins, tetraphenylethane-type epoxy resins, and the like are included. An epoxy resin may be used individually by 1 type, and may be used in combination of 2 or more types.

Component (A) is preferably an aromatic skeleton-containing epoxy resin from the viewpoint of lowering the average linear thermal expansion coefficient, and includes bisphenol A-type epoxy resin, bisphenol F-type epoxy resin, naphthalene-type epoxy resin, biphenyl-type epoxy resin, and diphenyl-type epoxy resin. It is more preferably one or more selected from cyclopentadiene type epoxy resins, and more preferably biphenyl type epoxy resins. The aromatic skeleton is a chemical structure generally defined as aromatic, and includes polycyclic aromatics and aromatic heterocycles.

The epoxy resin is preferably an epoxy resin having two or more epoxy groups in one molecule. When the non-volatile component of the epoxy resin is 100 mass %, at least 50 mass % or more of the epoxy resin preferably has two or more epoxy groups in one molecule. Among them, it is preferable to include an epoxy resin that has three or more epoxy groups in one molecule and is solid at a temperature of 20° C. (referred to as “solid epoxy resin”). The epoxy resin may contain only a solid epoxy resin, has two or more epoxy groups in one molecule, and is a liquid epoxy resin at a temperature of 20° C. (referred to as a “liquid epoxy resin”) and a solid epoxy resin. It may also contain a similar epoxy resin. By using both a liquid epoxy resin and a solid epoxy resin as epoxy resins, a resin composition having excellent flexibility can be obtained. Moreover, the breaking strength of the cured product of the resin composition is also improved.

Examples of liquid epoxy resins include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol AF type epoxy resin, naphthalene type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, phenol novolac type epoxy resin, ester skeleton. An alicyclic epoxy resin having a type epoxy resins and naphthalene type epoxy resins are more preferred. Specific examples of liquid epoxy resins include "HP4032", "HP4032D" and "HP4032SS" (naphthalene-type epoxy resins) manufactured by DIC Corporation, "828US", "jER828EL" and "825" manufactured by Mitsubishi Chemical Corporation. "Epikote 828EL" (bisphenol A type epoxy resin), "jER807", "1750" (bisphenol F type epoxy resin), "jER152" (phenol novolac type epoxy resin), "630", "630LSD" (glycidylamine type epoxy resin) resin), "ZX1059" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd. (mixture of bisphenol A type epoxy resin and bisphenol F type epoxy resin), "EX-721" manufactured by Nagase ChemteX Corporation (glycidyl ester type epoxy resin), Daicel Co., Ltd. "Celoxide 2021P" (alicyclic epoxy resin having an ester skeleton), "PB-3600" (epoxy resin having a butadiene structure), Nippon Steel Chemical Co., Ltd. "ZX1658", "ZX1658GS" (liquid 1,4-glycidylcyclohexane). These may be used individually by 1 type, and may be used in combination of 2 or more type.

Solid epoxy resins include naphthalene type tetrafunctional epoxy resin, cresol novolak type epoxy resin, dicyclopentadiene type epoxy resin, trisphenol type epoxy resin, naphthol type epoxy resin, biphenyl type epoxy resin, naphthylene ether type epoxy resin, Anthracene type epoxy resin, bisphenol A type epoxy resin and tetraphenylethane type epoxy resin are preferred, and naphthalene type tetrafunctional epoxy resin, naphthol type epoxy resin and biphenyl type epoxy resin are more preferred.

Specific examples of solid epoxy resins include "HP4032H" (naphthalene-type epoxy resin), "HP-4700", "HP-4710" (naphthalene-type tetrafunctional epoxy resin), and "N-690" manufactured by DIC Corporation. (cresol novolak type epoxy resin), "N-695" (cresol novolak type epoxy resin), "HP-7200" (dicyclopentadiene type epoxy resin), "HP-7200HH", "HP-7200H", "EXA- 7311", "EXA-7311-G3", "EXA-7311-G4", "EXA-7311-G4S", "HP6000" (naphthylene ether type epoxy resin), "EPPN-502H" manufactured by Nippon Kayaku Co., Ltd. "(trisphenol type epoxy resin),"NC7000L"(naphthol novolak type epoxy resin),"NC3000H","NC3000","NC3000L","NC3100"(biphenyl type epoxy resin), Nippon Steel & Sumikin Chemical Co., Ltd." ESN475V" (naphthalene type epoxy resin), "ESN485" (naphthol novolac type epoxy resin), Mitsubishi Chemical Corporation "YX4000H", "YX4000", "YL6121" (biphenyl type epoxy resin), "YX4000HK" (Bixylenol type epoxy resin), “YX8800” (anthracene type epoxy resin), “PG-100” and “CG-500” manufactured by Osaka Gas Chemicals Co., Ltd., “YL7760” manufactured by Mitsubishi Chemical Corporation (bisphenol AF type epoxy resin) , “YL7800” (fluorene type epoxy resin), Mitsubishi Chemical Corporation “jER1010” (solid bisphenol A type epoxy resin), and “jER1031S” (tetraphenylethane type epoxy resin). These may be used individually by 1 type, and may be used in combination of 2 or more type.

When a liquid epoxy resin and a solid epoxy resin are used together as epoxy resins, the ratio by mass (liquid epoxy resin:solid epoxy resin) is in the range of 1:0.1 to 1:15. preferable. By setting the amount ratio of the liquid epoxy resin to the solid epoxy resin in such a range, it is possible to i) make the adhesiveness suitable when used in the form of an adhesive film, and ii) use it in the form of an adhesive film. In some cases, sufficient flexibility can be obtained, handleability can be improved, and iii) a cured product having sufficient breaking strength can be obtained. From the viewpoint of the above effects i) to iii), the amount ratio of the liquid epoxy resin to the solid epoxy resin (liquid epoxy resin: solid epoxy resin) is 1:0.5 to 1:10 in mass ratio. A range is more preferred, with a range of 1:1 to 1:8 being even more preferred.

From the viewpoint of obtaining an insulating layer exhibiting good mechanical strength and insulation reliability, the content of the epoxy resin in the resin composition is preferably 5% by mass or more, more preferably 10% by mass, when the nonvolatile component is 100% by mass. It is at least 20% by mass, more preferably at least 20% by mass. The content of the epoxy resin is preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less, provided that the effects of the present invention can be obtained.

The epoxy equivalent of the epoxy resin is preferably 50-5000, more preferably 50-3000, still more preferably 80-2000, still more preferably 110-1000. By setting it as this range, the crosslink density of hardened|cured material is enough and it can be set as the insulating layer with small surface roughness. The epoxy equivalent is the mass of a resin containing one equivalent of epoxy groups, and can be measured according to JIS K7236.

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

<Component (B) curing agent>
The resin composition contains component (B) a curing agent. The curing agent is not particularly limited as long as it has the function of curing the epoxy resin. Component (B) curing agents include, for example, phenol curing agents, naphthol curing agents, active ester curing agents, benzoxazine curing agents, cyanate ester curing agents, and carbodiimide curing agents. A single curing agent may be used alone, or two or more curing agents may be used in combination. Component (B) is preferably one or more selected from phenol-based curing agents, naphthol-based curing agents, active ester-based curing agents, carbodiimide-based curing agents, and cyanate ester-based curing agents. is preferably

As the phenolic curing agent and the naphtholic curing agent, a phenolic curing agent having a novolac structure or a naphtholic curing agent having a novolac structure is preferable from the viewpoint of heat resistance and water resistance. From the viewpoint of adhesion to the conductor layer, a nitrogen-containing phenolic curing agent is preferable, and a triazine skeleton-containing phenolic curing agent is more preferable. Among them, a triazine skeleton-containing phenol novolac curing agent is preferable from the viewpoint of highly satisfying heat resistance, water resistance, and adhesion to the conductor layer.

Specific examples of phenol-based curing agents and naphthol-based curing agents include Meiwa Kasei Co., Ltd. “MEH-7700”, “MEH-7810”, “MEH-7851”, “MEH-7851H”, Nippon Kayaku Co., Ltd. ) manufactured by “NHN”, “CBN”, “GPH”, manufactured by Nippon Steel & Sumikin Co., Ltd. “SN170”, “SN180”, “SN190”, “SN475”, “SN485”, “SN495”, “SN375”, “SN395 ”, DIC Corporation “TD-2090”, “LA-7052”, “LA-7054”, “LA-1356”, “LA-3018-50P”, “EXB-9500”.

From the viewpoint of obtaining an insulating layer for high-frequency circuits having excellent adhesion to the conductor layer, the component (B) is preferably an active ester curing agent. There are no particular restrictions on the active ester curing agent. Active ester curing agents generally have two or more highly reactive ester groups per molecule, such as phenol esters, thiophenol esters, N-hydroxyamine esters, and esters of heterocyclic hydroxy compounds. A compound is preferably used. The active ester curing agent is preferably a compound 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 preferred, and an active ester curing agent obtained from a carboxylic acid compound and a phenol compound and/or a naphthol compound is more preferred.

Carboxylic acid compounds that may be used include, for example, benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid.

Phenolic or naphthol compounds that can be used include, for example, hydroquinone, resorcinol, bisphenol A, bisphenol F, bisphenol S, phenolphthalin, methylated bisphenol A, methylated bisphenol F, methylated bisphenol S, phenol, o-cresol. , m-cresol, p-cresol, catechol, α-naphthol, β-naphthol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone , phloroglucin, benzenetriol, dicyclopentadiene-type diphenol compounds, and phenol novolacs. Here, the term "dicyclopentadiene-type diphenol compound" refers to a diphenol compound obtained by condensing one molecule of dicyclopentadiene with two molecules of phenol.

Specific examples of active ester curing agents include active ester compounds containing a dicyclopentadiene type diphenol structure, active ester compounds containing a naphthalene structure, active ester compounds containing acetylated phenol novolacs, and benzoylated phenol novolacs. Among them, an active ester compound containing a naphthalene structure and an active ester compound containing a dicyclopentadiene-type diphenol structure are more preferable. "Dicyclopentadiene-type diphenol structure" represents a divalent structural unit consisting of phenylene-dicyclopentylene-phenylene.

Examples of commercially available active ester curing agents include "EXB9451", "EXB9460", "EXB9460S" and "HPC-8000-65T" manufactured by DIC Corporation, which are active ester compounds containing a dicyclopentadiene type diphenol structure. ", "HPC-8000H-65TM", "EXB-8000L-65TM", "EXB9416-70BK" manufactured by DIC Corporation, which is an active ester compound containing a naphthalene structure, and an active ester compound containing an acetylated phenol novolac "DC808" manufactured by Mitsubishi Chemical Co., Ltd.;

Specific examples of benzoxazine-based curing agents include “HFB2006M” manufactured by Showa High Polymer Co., Ltd., and “Pd” and “Fa” manufactured by Shikoku Kasei Kogyo Co., Ltd.

Examples of cyanate ester curing agents include bisphenol A dicyanate, polyphenolcyanate, oligo(3-methylene-1,5-phenylenecyanate), 4,4′-methylenebis(2,6-dimethylphenylcyanate), 4,4 '-ethylidene diphenyl dicyanate, hexafluorobisphenol A dicyanate, 2,2-bis(4-cyanate)phenylpropane, 1,1-bis(4-cyanatophenylmethane), bis(4-cyanate-3,5-dimethyl Bifunctional cyanate resins such as phenyl)methane, 1,3-bis(4-cyanatophenyl-1-(methylethylidene))benzene, bis(4-cyanatophenyl)thioether, and bis(4-cyanatophenyl)ether, phenol Polyfunctional cyanate resins derived from novolacs, cresol novolacs, etc., and prepolymers obtained by partially triazine-forming these cyanate resins.

Specific examples of cyanate ester curing agents include “PT30” and “PT60” manufactured by Lonza Japan Co., Ltd. (both are phenol novolak type polyfunctional cyanate ester resins), “BA230” and “BA230S75” (one type of bisphenol A dicyanate). a prepolymer that is partially or wholly triazined to form a trimer).

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

The ratio of the epoxy resin to the curing agent is [total number of epoxy groups in the epoxy resin]:[total number of reactive groups in the curing agent], and is in the range of 1:0.1 to 1:1. is preferred, 1:0.2 to 1:0.9 is more preferred, and 1:0.3 to 1:0.8 is even more preferred. 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 curing agent. In addition, the total number of epoxy groups in the epoxy resin is the sum of the values obtained by dividing the mass of the non-volatile component of each epoxy resin by the epoxy equivalent, and the total number of reactive groups in the curing agent is , is the value obtained by dividing the mass of the non-volatile component of each curing agent by the reactive group equivalent and totaling the values for all curing agents. By setting the ratio between the epoxy resin and the curing agent within such a range, the heat resistance of the cured product of the resin composition is further improved.

The content of the curing agent in the resin composition is not particularly limited. The content in the resin composition is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, when the nonvolatile component is 100% by mass. Also, the content of the curing agent in the resin composition is preferably 3% by mass or more, more preferably 5% by mass or more, and still more preferably 7% by mass or more.

<Component (C) inorganic filler>
The resin composition may further contain component (C) an inorganic filler. The material of the inorganic filler is not particularly limited. Examples of inorganic filler materials include silica, alumina, glass, cordierite, silicon oxide, barium sulfate, barium carbonate, talc, clay, mica powder, zinc oxide, hydrotalcite, boehmite, aluminum hydroxide, Magnesium hydroxide, calcium carbonate, magnesium carbonate, magnesium oxide, boron nitride, aluminum nitride, manganese nitride, aluminum borate, strontium carbonate, strontium titanate, calcium titanate, magnesium titanate, bismuth titanate, titanium oxide, zirconium oxide , barium titanate, barium zirconate titanate, barium zirconate, calcium zirconate, zirconium phosphate, and zirconium tungstate phosphate. Among these, silica is particularly suitable. As silica, spherical silica is preferable. An inorganic filler may be used individually by 1 type, and may be used in combination of 2 or more type.

The average particle size of the inorganic filler is preferably 20 µm or less, more preferably 10 µm or less, and still more preferably, from the viewpoint of improving the embedding property of the conductor layer and obtaining an insulating layer for high-frequency circuits with low surface roughness. is 5 μm or less, more preferably 3 μm or less, still more preferably 1 μm or less. The average particle size is preferably 0.01 μm or more, more preferably 0.05 μm or more, and still more preferably 0.1 μm or more. Examples of commercially available inorganic fillers having such an average particle size include "SP60-05" and "SP507-05" manufactured by Nippon Steel & Sumikin Materials Co., Ltd., "YC100C" manufactured by Admatechs Co., Ltd., " YA050C", "YA050C-MJE", "YA010C", "UFP-30" manufactured by Denka Co., Ltd., "Silfil NSS-3N", "Silfil NSS-4N", "Silfil NSS-5N" manufactured by Tokuyama Co., Ltd., "SC2500SQ", "SO-C4", "SO-C2" and "SO-C1" manufactured by Admatechs Co., Ltd. can be mentioned.

The average particle size of the inorganic filler can be measured by a laser diffraction/scattering method based on Mie scattering theory. Specifically, the particle size distribution of the inorganic filler is prepared on a volume basis using a laser diffraction/scattering particle size distribution analyzer, and the median diameter thereof can be used as the average particle size for measurement. As a measurement sample, a sample in which an inorganic filler is ultrasonically dispersed in water can be preferably used. As a laser diffraction scattering type particle size distribution analyzer, "LA-500" manufactured by HORIBA, Ltd. can be used.

Inorganic fillers include aminosilane-based coupling agents, epoxysilane-based coupling agents, mercaptosilane-based coupling agents, alkoxysilane compounds, organosilazane compounds, titanate-based coupling agents, etc., from the viewpoint of improving moisture resistance and dispersibility. It is preferably treated with one or more surface treatment agents. Examples of commercially available surface treatment agents include "KBM403" (3-glycidoxypropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd., "KBM803" (3-mercaptopropyltrimethoxysilane) manufactured by Shin-Etsu Chemical Co., Ltd. silane), Shin-Etsu Chemical Co., Ltd. "KBE903" (3-aminopropyltriethoxysilane), Shin-Etsu Chemical Co., Ltd. "KBM573" (N-phenyl-3-aminopropyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd. "SZ-31" (hexamethyldisilazane), Shin-Etsu Chemical Co., Ltd. "KBM-103" (phenyltrimethoxysilane), Shin-Etsu Chemical Co., Ltd. "KBM-4803" (long chain epoxy type silane coupling agent).

The degree of surface treatment by the surface treatment agent can be evaluated by the amount of carbon per unit surface area of the inorganic filler. The amount of carbon per unit surface area of the inorganic filler is preferably 0.02 mg/m ² or more, more preferably 0.1 mg/m ² or more, from the viewpoint of improving the dispersibility of the inorganic filler. More preferably, it is 0.2 mg/m ² or more. On the other hand, from the viewpoint of preventing an increase in the melt viscosity of the resin varnish and the melt viscosity when the resin varnish is formed into a sheet, the amount of carbon per unit surface area of the inorganic filler is preferably 1 mg/m ² or less. It is more preferably 0.8 mg/m ² or less, even more preferably 0.5 mg/m ² or less.

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

From the viewpoint of obtaining an insulating layer having a low dielectric constant, the content of the inorganic filler in the resin composition is preferably 10% by mass or more, more preferably 10% by mass or more, when the non-volatile component in the resin composition is 100% by mass. is 20% by mass or more, more preferably 30% by mass or more, or 40% by mass or more. The content of the inorganic filler in the resin composition is preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably, from the viewpoint of improving the mechanical strength of the insulating layer, particularly adhesion strength. is 70% by mass or less.

<Component (D) organic filler>
The resin composition may contain component (D) an organic filler.

The particle size of component (D) is not particularly limited. The average particle size of the component (D) is preferably 5 μm or less, more preferably 4 μm or less, and even more preferably 3 μm or less, since it has excellent dispersibility in the resin composition. The average particle size of component (D) is preferably 0.05 μm or more, more preferably 0.08 μm or more, and even more preferably 0.10 μm or more. Therefore, component (D) preferably has an average particle size of 0.05 μm to 5 μm, more preferably 0.08 μm to 4 μm, even more preferably 0.10 μm to 3 μm.

Component (D) is not particularly limited, provided that it can reduce the dielectric constant of the insulating layer for high frequency circuits. Examples of component (D) include fluororesin, fluororubber, polyethylene, polypropylene, polystyrene, polycarbonate, norbornene-based resin, addition copolymer resin with olefins, polyphenylene ether, bismaleimide-triazine-resin, and polyetherimide. , polyimides, polyetheretherketones, and liquid crystal polymers. Suitable component (D) includes, for example, fluoropolymer particles, cycloolefin polymer particles, polyphenylene ether particles, and polystyrene particles. Among these, fluoropolymer particles containing a fluororesin are preferred from the viewpoint of reducing the dielectric constant of the insulating layer for high frequency circuits.

Examples of fluororesins include polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), perfluoroethylene propene copolymer (FEP), ethylene/tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-perfluorodioxy Sole copolymer (TFE/PDD), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE), ethylene-chlorotrifluoroethylene copolymer (ECTFE), polyvinyl fluoride (PVF). These resins may be used individually by 1 type, and may be used in combination of 2 or more type.

From the viewpoint of further reducing the dielectric constant of the insulating layer for high frequency circuits, it is preferable to use PTFE as the fluororesin. In other words, PTFE particles, which are fluoropolymer particles containing PTFE as the fluororesin, are preferably used as the component (D).

The weight average molecular weight of PTFE is preferably 5,000,000 or less, more preferably 4,000,000 or less, and even more preferably 3,000,000 or less.

Commercially available products may be used as the fluoropolymer particles. Specific examples of PTFE particles, which are commercially available fluorine-based polymer particles, include "Lubron L-2" manufactured by Daikin Industries, Ltd., "Lubron L-5" manufactured by Daikin Industries, Ltd., and "Lubron L-5" manufactured by Daikin Industries, Ltd. L-5F", "FluonPTFE L-170JE" manufactured by Asahi Glass Co., Ltd., "FluonPTFE L-172JE" manufactured by Asahi Glass Co., Ltd., "FluonPTFE L-173JE" manufactured by Asahi Glass Co., Ltd., "KTL-500F" manufactured by Kitamura Co., Ltd. , "KTL-2N" manufactured by Kitamura Co., Ltd., "KTL-1N" manufactured by Kitamura Co., Ltd., and "TLP10F-1" manufactured by Mitsui-DuPont Fluorochemical Co., Ltd.

Component (D) may contain, for example, surface-treated particles. Surface treatment includes, for example, surface treatment with a surface treatment agent. The surface treatment agent is not particularly limited. Surface treatment agents include surfactants such as nonionic surfactants, amphoteric surfactants, cationic surfactants and anionic surfactants, as well as inorganic fine particles. When the component (D) is a fluoropolymer particle containing a fluororesin, it is preferable to use a fluorosurfactant as the surface treatment agent from the viewpoint of affinity. Specific examples of fluorine-based surfactants include "Surflon S-243" (perfluoroalkyl ethylene oxide adduct) manufactured by AGC Seimi Chemical Co., Ltd., "Megafac F-251" manufactured by DIC Corporation, and DIC Corporation. ) "Megafac F-477" manufactured by DIC Corporation, "Megafac F-553" manufactured by DIC Corporation, "Megafac R-40" manufactured by DIC Corporation, "Megafac R-43" manufactured by DIC Corporation, DIC "Megafac R-94" manufactured by NEOS Corporation, "FTX-218" manufactured by NEOS Corporation, "Ftergent 610FM" manufactured by NEOS Corporation, and "Ftergent 730LM" manufactured by NEOS Corporation.

The content of component (D) is preferably 5% by mass or more, more preferably 10% by mass or more, more preferably 15% by mass, from the viewpoint of effectively reducing the dielectric constant of the insulating layer for high frequency circuits. It is more preferable that it is above. The content of component (D) is preferably 60% by mass or less, more preferably 55% by mass or less, and further preferably 45% by mass or less, 35% by mass or less, and 30% by mass or less. . Therefore, the content of component (D) is preferably 5% by mass to 60% by mass, more preferably 10% by mass to 35% by mass, even more preferably 15% by mass to 30% by mass. .

<Resin Having Component (E) Unsaturated Hydrocarbon Group>
The resin composition preferably contains component (E) a resin having an unsaturated hydrocarbon group. By including the component (E), the compatibility of the resin composition can be enhanced, and a resin composition having a good melt viscosity can be obtained. Component (E) may be used alone or in combination of two or more.

Component (E) is not particularly limited as long as it has an unsaturated hydrocarbon group. The unsaturated hydrocarbon group is preferably an acryl group, a methacryl group, a styryl group, or an olefin group. As used herein, the term "olefin group" refers to an aliphatic hydrocarbon group having a carbon-carbon double bond in its molecule. Olefin groups include, for example, allyl groups, vinyl groups, and propenyl groups. That is, component (E) is preferably a resin having one or more unsaturated hydrocarbon groups selected from the group consisting of acrylic groups, methacrylic groups, styryl groups, allyl groups, vinyl groups and propenyl groups. Component (E) preferably has an aromatic ring in its structure. Among them, the component (E) is preferably a compound (resin) represented by the following formula (1) or (4) from the viewpoint of improving the stability during storage.

In formula (1), R ¹ to R ⁶ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. A represents a group represented by the following formula (2) or the following formula (3).

In formula (2), E represents a group represented by formula (E-1), (E-2) or (E-3) below.

In formula (3), R ⁷ to R ¹⁴ each independently represent a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. E represents the following formula (E-1), (E-2) or (E-3). a and b are integers from 0 to 100, and at least one of a and b is an integer other than 0;

In formulas (E-1) to (E-3), R ¹⁵ to R ³⁴ each independently represent a hydrogen atom, an alkyl group having 6 or less carbon atoms, or a phenyl group. G represents a linear, branched or cyclic divalent hydrocarbon group having 20 or less carbon atoms.

In formula (1), R ¹ to R ⁶ each independently represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ¹ to R ⁶ are preferably hydrogen atoms. Examples of alkyl groups having 1 to 4 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group.

Examples of alkyl groups having 6 or less carbon atoms for R ⁷ to R ¹⁴ in formula (3) and R ¹⁵ to R ³⁴ in formulas (E-1) to (E-3) include methyl group, Examples include ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, pentyl group and hexyl group. A hydrogen atom and a methyl group are preferable as R ⁷ to R ¹⁴ .

a and b are integers from 0 to 100, and at least one of a and b is an integer other than 0; a and b are preferably integers of 0-50, more preferably integers of 0-10.

G represents a linear, branched or cyclic divalent hydrocarbon group having 20 or less carbon atoms. The divalent hydrocarbon group includes, for example, an alkylene group having 1 to 20 carbon atoms, an alkenylene group having 2 to 20 carbon atoms, and an alkynylene group having 2 to 20 carbon atoms. Examples of the alkylene group having 1 to 20 carbon atoms include methylene group, ethylene group, propylene group and butylene group. The alkenylene group having 2 to 20 carbon atoms includes, for example, vinylene group, propenylene group and butenylene group. Examples of alkynylene groups having 2 to 20 carbon atoms include ethynylene, propynylene and butynylene groups.

The vinyl group in the resin having a vinyl group may have a substituent. In addition, the alkyl group, phenyl group and divalent hydrocarbon group may also have a substituent.

Such substituents are not particularly limited. Substituents include, for example, a halogen atom, a group represented by —OH, —O—C _1-6 alkyl group, —N(C _1-6 alkyl group) ₂ , C _1-6 alkyl group, C _{6- 10} aryl group, -NH ₂ group, -CN group, -C(O)O-C _1-6 alkyl group, -COOH group, -C(O)H and groups represented by —NO ₂ .

The meanings of “C _1-6 ” and “C _6-10 ” related to the substituents will be explained by generalizing these terms to “C _pq ”. “C _p−q ” (where p and q are positive integers and satisfies p<q) means that the number of carbon atoms of the organic group described immediately after this term is p to q represents Specifically, for example, a “C _1-6 alkyl group” represents an “alkyl group having 1 to 6 carbon atoms”.

The substituent may further have a substituent (hereinafter sometimes referred to as "secondary substituent"). The secondary substituents include, for example, the same groups as the already explained substituents.

Specific examples of component (E) include compounds represented by the following formulas. The invention is not limited to this.

In the formula, R ¹ to R ⁶ , E, a, and b are as defined in formula (1) or formula (3) above, and their preferred ranges are also the same.

Specific examples of the component (E) include "OPE-2St 2200 (number average molecular weight 2200)" and "OPE-2St 1200 (number average molecular weight 1200)" (styrene-modified polyphenylene ether resin) manufactured by Mitsubishi Gas Chemical Co., Ltd., "YL7776 (number average molecular weight: 331)" (bixylenol diallyl ether resin) manufactured by Mitsubishi Chemical Corporation can be mentioned.

The number average molecular weight of component (E) is preferably in the range of 100 to 10000 from the viewpoint of preventing volatilization during drying of the resin varnish and preventing excessive increase in the melt viscosity of the resin composition. It is more preferably in the range of 200-3000.

The number average molecular weight is measured by a gel permeation chromatography (GPC) method (converted to polystyrene). Specifically, the number average molecular weight by the GPC method is measured by using "LC-9A/RID-6A" manufactured by Shimadzu Corporation as a measuring device, and "Shodex K-800P/K-" manufactured by Showa Denko Co., Ltd. as a column. 804L/K-804L", using chloroform or the like as a mobile phase, measuring at a column temperature of 40° C., and calculating using a standard polystyrene calibration curve.

From the viewpoint of obtaining a resin composition with good compatibility, the content of component (E) is preferably 30% by mass or less, more preferably 25% by mass or less, when the non-volatile component is 100% by mass. , more preferably 20% by mass or less, or 15% by mass or less. The content of component (E) is preferably 1% by mass or more, more preferably 2% by mass or more, and still more preferably 3% by mass or more when the non-volatile component is taken as 100% by mass.

By including the component (E) in the resin composition, the already explained component (D) (especially the fluoropolymer particles) can be more uniformly dispersed in the resin composition. As a result, the uniformity of the resin composition is improved, so that the adhesion to the core substrate can be further improved, thereby improving the electrical properties such as the dielectric constant of the insulating layer formed, and improving the reliability of the device. can be improved.

<Component (F) Indene cumarone resin>
The resin composition preferably contains component (F) indene cumarone resin. Containing the component (F) improves the compatibility and makes it possible to obtain a resin composition having a good balance of physical properties. The coumarone skeleton contained in component (F) has high compatibility with highly polar epoxy resins and curing agents, and the indene skeleton and coumarone skeleton contained in component (F) have high compatibility with low polar vinyl resins. Therefore, it is thought that it functions as a compatibilizer between a resin with high polarity and a resin with low polarity, and the compatibility of the entire resin composition is improved.

Examples of component (F) include copolymers of indene and coumarone, and copolymers of indene, coumarone and styrene.

The content ratio of the coumarone structure in the indene cumarone resin is preferably 5 mol % or more, more preferably 8 mol % or more, still more preferably 10 mol % or more. The content ratio of the coumarone structure in the indene cumarone resin is preferably 40 mol % or less, more preferably 35 mol % or less, still more preferably 30 mol % or less.

The content ratio of the indene structure in the indene cumarone resin is preferably 30 mol % or more, more preferably 35 mol % or more, and still more preferably 40 mol % or more. The content ratio of the indene structure in the indene cumarone resin is preferably 80 mol % or less, more preferably 75 mol % or less, and still more preferably 70 mol % or less.

When the indene cumarone resin is a copolymer of indene, coumarone and styrene, the content ratio of the styrene structure is preferably 20 mol% or more, more preferably 25 mol% or more, still more preferably 30 mol%. That's it. When the indene cumarone resin is a copolymer of indene, coumarone and styrene, the content ratio of the styrene structure is preferably 70 mol% or less, more preferably 65 mol% or less, still more preferably 60 mol%. It is below.

Specific examples of the indene cumarone resin include “H-100”, “V-120S” and “V-120” manufactured by Nichinuri Chemical Co., Ltd.

From the viewpoint of obtaining a resin composition with good compatibility, the content of component (F) is 1% by mass or more, preferably 2% by mass or more, more preferably 3% by mass, when the non-volatile component is 100% by mass. % by mass or more. The content of component (F) is 20% by mass or less, preferably 15% by mass or less, more preferably 15% by mass or less, from the viewpoint of obtaining a resin composition having good melt viscosity and obtaining an insulating layer having excellent adhesion to a substrate. It is 10% by mass or less, or 8% by mass or less.

By containing the component (F), the resin composition according to the present invention can improve the compatibility and improve the melt viscosity. As a result, the dielectric constant of the high-frequency circuit insulating layer formed using the resin composition can be further lowered, and the adhesion to the inner layer substrate and the adhesion to the conductor layer can be improved, thereby improving the device. reliability can be improved.

The resin composition may contain either one of the component (E) and the component (F), or may contain both.

<Component (G) curing accelerator>
The resin composition may contain component (G) a curing accelerator. Examples of curing accelerators include phosphorus curing accelerators, amine curing accelerators, imidazole curing accelerators, guanidine curing accelerators, metal curing accelerators, and peroxide curing accelerators. The curing accelerator is preferably a phosphorus curing accelerator, an amine curing accelerator, an imidazole curing accelerator, or a metallic curing accelerator, and an amine curing accelerator, an imidazole curing accelerator, or a metallic curing accelerator more preferred. A hardening accelerator may be used individually by 1 type, and may be used in combination of 2 or more type.

Phosphorus curing accelerators include, for example, triphenylphosphine, phosphonium borate compounds, tetraphenylphosphonium tetraphenylborate, n-butylphosphonium tetraphenylborate, tetrabutylphosphonium decanoate, (4-methylphenyl)triphenylphosphonium thiocyanate. , tetraphenylphosphonium thiocyanate, and butyltriphenylphosphonium thiocyanate. As the phosphorus curing accelerator, triphenylphosphine and tetrabutylphosphonium decanoate are preferred.

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

Examples of imidazole curing accelerators 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 (2P4MZ), 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 isocyanurate, 2-phenylimidazole isocyanurate, 2-phenyl-4,5-dihydroxymethylimidazole , 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2,3-dihydro-1H-pyrrolo[1,2-a]benzimidazole, 1-dodecyl-2-methyl-3-benzylimidazolium chloride, 2 -Methylimidazoline, 2-phenylimidazoline, and other imidazole compounds, and adducts of imidazole compounds and epoxy resins. Preferred imidazole curing accelerators are 2-ethyl-4-methylimidazole and 1-benzyl-2-phenylimidazole.

A commercially available product may be used as the imidazole-based curing accelerator. Examples of commercially available imidazole curing accelerators that can be used include "P200-H50" manufactured by Mitsubishi Chemical Corporation.

Guanidine curing accelerators include, for example, dicyandiamide, 1-methylguanidine, 1-ethylguanidine, 1-cyclohexylguanidine, 1-phenylguanidine, 1-(o-tolyl)guanidine, dimethylguanidine, diphenylguanidine, trimethylguanidine, Tetramethylguanidine, Pentamethylguanidine, 1,5,7-triazabicyclo[4.4.0]dec-5-ene, 7-methyl-1,5,7-triazabicyclo[4.4.0] Dec-5-ene, 1-methylbiguanide, 1-ethylbiguanide, 1-n-butylbiguanide, 1-n-octadecylbiguanide, 1,1-dimethylbiguanide, 1,1-diethylbiguanide, 1-cyclohexylbiguanide, 1 -allylbiguanide, 1-phenylbiguanide, 1-(o-tolyl)biguanide. Preferred guanidine curing accelerators are dicyandiamide and 1,5,7-triazabicyclo[4.4.0]dec-5-ene.

Metal-based curing accelerators include, for example, organometallic complexes or salts of metals such as cobalt, copper, zinc, iron, nickel, manganese, and tin. Specific examples of organometallic complexes include organocobalt complexes such as cobalt (II) acetylacetonate and cobalt (III) acetylacetonate, organocopper complexes such as copper (II) acetylacetonate, and zinc (II) acetylacetonate. organic zinc complexes such as iron (III) acetylacetonate, organic iron complexes such as nickel (II) acetylacetonate, organic nickel complexes such as nickel (II) acetylacetonate, and organic manganese complexes such as manganese (II) acetylacetonate. Examples of organic metal salts include zinc octoate, tin octoate, zinc naphthenate, cobalt naphthenate, tin stearate, and zinc stearate.

Examples of peroxide-based curing accelerators include cyclohexanone peroxide, tert-butyl peroxybenzoate, methyl ethyl ketone peroxide, dicumyl peroxide, tert-butyl cumyl peroxide, di-tert-butyl peroxide, and diisopropylbenzene hydrochloride. Peroxide, cumene hydroperoxide, tert-butyl hydroperoxide.

A commercially available product can be used as the peroxide curing accelerator. Examples of peroxide-based curing accelerators include NOF Corporation's "Percumyl D".

The content of the curing accelerator in the resin composition is not particularly limited. The content of the curing accelerator is preferably 0.01% by mass to 1% by mass when the non-volatile component is taken as 100% by mass.

<Component (H) silane compound>
The resin composition may contain component (H) a silane compound. As the silane compound, a fluorine-based silane compound is preferable. Component (H) the silane compound is preferably 3,3,3-trifluoropropyltrimethoxysilane, more preferably 3,3,3-trifluoropropyltrimethoxysilane. Examples of commercially available silane compounds include "KBM-7103" manufactured by Shin-Etsu Chemical Co., Ltd.

By including the component (H) silane compound in the resin composition, the components (C) and (D) already described can be more uniformly dispersed in the resin composition. As a result, the uniformity of the resin composition is improved, and the electrical properties such as the dielectric constant of the insulating layer formed and the physical properties such as adhesion can be further improved.

<Component (I) thermoplastic resin>
The resin composition may contain the component (I) thermoplastic resin. Examples of thermoplastic resins include phenoxy resins, polyvinyl acetal resins, polyolefin resins, polybutadiene resins, polyimide resins, polyamideimide resins, polyetherimide resins, polysulfone resins, polyethersulfone resins, polycarbonate resins, polyetheretherketone resins, A polyester resin is mentioned. A phenoxy resin is preferable as the thermoplastic resin. The thermoplastic resin may be used singly or in combination of two or more.

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

Examples of phenoxy resins 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, and terpene. and a phenoxy resin having one or more skeletons selected from the group consisting of a trimethylcyclohexane skeleton. The terminal of the phenoxy resin may be any functional group such as a phenolic hydroxyl group or an epoxy group. A phenoxy resin may be used individually by 1 type, and may be used in combination of 2 or more type. Specific examples of phenoxy resins include "1256" and "4250" (both phenoxy resins containing bisphenol A skeleton) manufactured by Mitsubishi Chemical Corporation, "YX8100" (phenoxy resin containing bisphenol S skeleton), and "YX6954" (bisphenol acetophenone skeleton-containing phenoxy resin), and in addition, Nippon Steel & Sumikin Chemical Co., Ltd. "FX280" and "FX293", Mitsubishi Chemical Corporation "YX6954BH30", "YX7553", "YX7553BH30", "YL7769BH30" , "YL6794", "YL7213", "YL7290", "YL7891BH30" and "YL7482".

Examples of polyvinyl acetal resins include polyvinyl formal resins and polyvinyl butyral resins. A polyvinyl butyral resin is preferable as the polyvinyl acetal resin. Specific examples of polyvinyl acetal resins include Denka Butyral 4000-2, Denka Butyral 5000-A, Denka Butyral 6000-C, Denka Butyral 6000-EP, manufactured by Denka Kogyo Co., Ltd. S-lec BH series, BX series (eg BX-5Z), KS series (eg KS-1), BL series and BM series manufactured by Sekisui Chemical Co., Ltd. can be mentioned.

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

A commercially available product may be used as the polyamide-imide resin. Specific examples of commercially available polyamide-imide resins that can be used include "VYLOMAX HR11NN" and "VYLOMAX HR16NN" manufactured by Toyobo Co., Ltd. Specific examples of polyamideimide resins include modified polyamideimides such as "KS9100" and "KS9300" (polysiloxane skeleton-containing polyamideimides) manufactured by Hitachi Chemical Co., Ltd.

A commercially available product may be used as the polyethersulfone resin. Specific examples of commercially available polyethersulfone resins that can be used include "PES5003P" manufactured by Sumitomo Chemical Co., Ltd.

A commercially available product may be used as the polysulfone resin. Specific examples of commercially available polysulfone resins that can be used include “P1700” and “P3500” manufactured by Solvay Advanced Polymers.

Among them, phenoxy resin and polyvinyl acetal resin are preferable as the thermoplastic resin. In one preferred embodiment, the thermoplastic resin comprises one or more selected from the group consisting of phenoxy resins and polyvinyl acetal resins.

When the resin composition contains a thermoplastic resin, the content of the thermoplastic resin is preferably 0.5% by mass to 15% by mass, more preferably 0.6% by mass, when the nonvolatile component is 100% by mass. ~12% by mass, more preferably 0.7% to 10% by mass.

<Component (J) flame retardant>
The resin composition may contain a component (J) flame retardant. Examples of flame retardants include organic phosphorus flame retardants, organic nitrogen-containing phosphorus compounds, nitrogen compounds, silicone flame retardants, and metal hydroxides. A flame retardant may be used individually by 1 type, or may use 2 or more types together.

A commercially available product may be used as the flame retardant. Examples of commercially available flame retardants that can be used include “HCA-HQ” manufactured by Sanko Co., Ltd. and “PX-200” manufactured by Daihachi Chemical Industry Co., Ltd.

When the resin composition contains a flame retardant, the content of the flame retardant is not particularly limited. The content of the flame retardant is preferably 0.5% by mass to 20% by mass, more preferably 0.5% by mass to 15% by mass, and still more preferably 0% by mass when the nonvolatile component is 100% by mass. .5 mass % to 10 mass %.

<Component (K) optional additive>
The resin composition may further contain optional additives as necessary. Such optional additives include, for example, organometallic compounds such as organocopper compounds, organozinc compounds and organocobalt compounds, and resins such as thickeners, antifoaming agents, leveling agents, adhesion imparting agents, and coloring agents. Additives are included.

[Semiconductor device]
A semiconductor device according to the high-frequency circuit board of the present invention includes the already-described high-frequency circuit board. In other words, the semiconductor device of the present invention can be manufactured using the high frequency circuit board of the present invention.

Examples of semiconductor devices include various semiconductor devices used in electrical appliances (eg, computers, mobile phones, digital cameras, televisions, etc.) and vehicles (eg, motorcycles, automobiles, trains, ships, aircraft, etc.).

A semiconductor device can be manufactured by mounting components (semiconductor chips) on conductive portions of a high-frequency circuit board. A "conducting part" is a "part where an electric signal can be transmitted on a high-frequency circuit board", and even if the part is on the surface of the high-frequency circuit board, it is embedded within the thickness of the high-frequency circuit board. It does not matter if it is a point. Also, the semiconductor chip is not particularly limited as long as it is an electric circuit element made of a semiconductor.

A semiconductor chip mounting method for manufacturing the semiconductor device of the present invention is not particularly limited as long as the semiconductor chip functions effectively. Specifically, the semiconductor chip mounting method includes a wire bonding mounting method, a flip chip mounting method, a mounting method using a build-up layer without bumps (BBUL), a mounting method using an anisotropic conductive film (ACF), and a non-conductive A mounting method using a film (NCF) can be mentioned. Here, "a mounting method using a build-up layer without bumps (BBUL)" means a "mounting method in which a semiconductor chip is directly embedded in a high-frequency circuit board and the semiconductor chip and the wiring of the high-frequency circuit board are connected." .

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

<Measurement method and evaluation method>
First, the measurement method and the evaluation method according to the example will be described.

1. Measurement of dielectric constant The resin varnish obtained in Examples and Comparative Examples described later is applied to the surface of a release-treated PET film (manufactured by Lintec Corporation, "PET501010"), which is a support. The composition layer was uniformly coated using a die coater so that the thickness of the composition layer was 40 μm, and dried at 80° C. to 110° C. (average 95° C.) for 6 minutes. After that, the substrate was heat-treated at 200° C. for 90 minutes, and the support was peeled off to obtain a cured product film.

The resulting cured film was cut into strips having a length of 80 mm and a width of 2 mm to obtain evaluation samples.

The dielectric constant of this evaluation sample was measured at a measurement frequency of 10 GHz and a measurement temperature of 23° C. by the cavity resonance perturbation method using “HP8362B” manufactured by Agilent Technologies.

Each of the two evaluation samples was measured, and the average value was calculated as the measured value of the dielectric constant Dk (B) of the evaluation sample (cured product of the resin composition).

In addition, a glass cloth-based epoxy resin double-sided copper clad laminate (copper foil thickness 18 μm, substrate thickness 0.8 mm, Panasonic Electric Works Co., Ltd. “R-1766”) was treated with an aqueous solution of ferric chloride on both sides. The copper foil was removed, and the dielectric constant of the glass cloth-based epoxy resin substrate (core substrate) was measured at 10 GHz and a measurement temperature of 23°C. As a result, the dielectric constant of the core substrate was 4.3.

2. Measurement of peeling strength (peel strength) between insulation layer for high frequency circuit and conductor layer (1) Formation of copper foil (adhesive film) with resin composition layer On the surface of the "MT18Ex" foil manufactured by Mitsui Kinzoku Kogyo Co., Ltd., which is a foil, a die coater is used to uniformly apply the resin composition layer so that the thickness of the dried resin composition layer is 40 μm, and the temperature is 80 ° C. to 110 ° C. (95° C. on average) for 6 minutes to obtain a copper foil with a resin composition layer.

(2) Lamination of copper foil with resin composition layer (adhesive film) Build-up laminator CVP700"), the resin composition layer is a glass cloth base epoxy resin double-sided copper clad laminate (copper foil thickness 18 μm, substrate thickness 0.8 mm, Panasonic Electric Works Co., Ltd. "R -1766") on both sides. Lamination was carried out by reducing the pressure to 13 hPa or less for 30 seconds, then increasing the temperature of the atmosphere to 100° C. and applying pressure to 0.74 MPa for 30 seconds. Then, the temperature of the atmosphere was set to 100° C., and the pressure was set to 0.5 MPa to perform hot pressing for 60 seconds.

(3) Formation of Cured Body with Copper Foil A laminate in which a copper foil with a laminated resin composition layer is laminated on a core substrate is heat-treated at 200° C. for 90 minutes under curing conditions to cure the resin composition layer. A hardened body (insulating layer for high-frequency circuits) was obtained by heating to form a hardened body with a copper foil.

(4) Formation of conductor layer (laminate) (electroplating)
After peeling off the carrier copper foil from the cured body with the copper foil obtained in the above step (3), copper sulfate electrolytic plating (electroplating) was performed to form a conductor layer to a thickness of 25 μm. Next, heat treatment was performed at 180° C. for 30 minutes to obtain a laminate having conductor layers (copper layers) on both sides. Using this laminate, the peeling strength (peel strength) of the conductor layer was measured.

(5) Measurement of peel strength between insulating layer for high-frequency circuit and conductor layer A strip-shaped cut with a width of 10 mm and a length of 100 mm was cut in the formed conductor layer, and one end in the length direction was peeled off. Grabbed with a hand gripper (“Autocom type testing machine AC-50CSL” manufactured by TSE Co., Ltd.) and peeled off 35 mm in the vertical direction (longitudinal direction) at a speed of 50 mm / min at normal temperature A peel strength (kgf/cm), which is a load of 1, was measured. In each case, the peeled surface was the interface between the high-frequency circuit insulating layer and the copper foil (“MT18Ex” foil manufactured by Mitsui Kinzoku Kogyo Co., Ltd.).
Table 2 shows the results.

3. Measurement of peel strength between inner layer substrate (core substrate) and insulating layer for high frequency circuit (1) Preparation of inner layer substrate Glass cloth base epoxy resin double-sided copper clad laminate (copper foil thickness 18 μm, A core substrate was obtained by removing the copper foils on both sides of a substrate having a thickness of 0.8 mm ("R-1766" manufactured by Panasonic Electric Works Co., Ltd.) with an aqueous solution of ferric chloride.

(2) Formation of copper foil with resin composition layer (adhesive film) The resin compositions obtained in Examples and Comparative Examples are applied to the surface of "MT18Ex" manufactured by Mitsui Kinzoku Kogyo Co., Ltd., which is a copper foil, after drying. The resin composition layer was uniformly coated using a die coater so that the thickness of the resin composition layer was 40 μm, and dried at 80° C. to 110° C. (average 95° C.) for 6 minutes to obtain a copper foil with a resin composition layer.

(3) Lamination of resin composition layer-attached copper foil (adhesive film) The obtained resin composition layer-attached copper foils (2 sheets) are placed in a batch-type vacuum pressure laminator (manufactured by Nikko Materials "2-stage build-up laminator CVP700") was used to laminate on both sides of the core substrate so that the resin composition layer was in contact with the core substrate. Lamination was carried out by reducing the pressure for 30 seconds to an air pressure of 13 hPa or less, setting the temperature of the rubber press part of the first chamber to 100° C., and applying pressure to 0.74 MPa for 30 seconds. Then, the temperature of the metal press part of the second chamber was set to 100° C., and the pressure was set to 0.5 MPa to perform hot pressing for 60 seconds.

(4) Formation of Cured Body with Copper Foil A laminate obtained by laminating a copper foil with a resin composition layer on a core substrate is subjected to a heat treatment at 200° C. for 90 minutes to cure the resin composition layer. A hardened body with a copper foil was formed as a body (insulating layer for high-frequency circuits).

(5) Formation of conductor layer (laminate) (electroplating)
After peeling off the carrier foil from the cured body with copper foil obtained in the above step (4), copper sulfate electroplating (electroplating) was performed to form a conductor layer so as to have a thickness of 25 μm. Next, heat treatment was performed at 180° C. for 30 minutes to obtain a laminate having conductor layers (copper layers) on both sides. Using this laminate, the peeling strength (peel strength) of the insulating layer for high frequency circuits was measured.

(6) Measurement of Peel Strength of Insulating Layer for High-Frequency Circuits A strip-shaped incision with a width of 10 mm and a length of 100 mm was made in the formed conductor layer, and one end in the length direction was peeled off and a gripping tool (T Co., Ltd.) was applied. Peel strength (kgf / cm) was measured.

Here, when the peeled surface is between the high-frequency circuit insulating layer and the conductor layer, that is, when only the conductor layer is peeled off from the laminate, the separation between the inner layer substrate and the high-frequency circuit insulating layer The peel strength was judged to be higher.

When the peel strength was 0.5 kgf/cm or more, it was determined as ◯ (good), and when the peel strength was less than 0.5 kgf/cm, it was determined as x (poor).
Table 2 shows the results.

[Example 1]
25 parts of bixylenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 190) and 15 parts of liquid bisphenol A type epoxy resin ("jER828US" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 187) were mixed with solvent naphtha. It was dissolved by stirring while heating to 25 parts, and then cooled to room temperature.

Spherical silica (“SO-C2” manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) surface-treated with a phenylaminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.) was added to the resulting mixture. ) and 120 parts of PTFE particles (“Lubron L-2” manufactured by Daikin Industries, Ltd., average particle size 3 μm) were mixed and dispersed by kneading with three rolls.

To the resulting mixed solution, 61.5 parts of an active ester curing agent ("HPC-8000-65T" manufactured by DIC Corporation, a toluene solution having an active group equivalent of about 223 and containing 65% by mass of non-volatile components), Resin having a vinyl group (Mitsubishi Gas Chemical Co., Ltd. "OPE-2St 2200", a toluene solution containing 60% by mass of non-volatile components) 25 parts, indene cumarone resin (Nikuri Chemical Co., Ltd. "H-100" ) 15 parts, 2-phenyl-4-methylimidazole (2.5 mass% MEK solution of ("2P4MZ" manufactured by Shikoku Kasei Co., Ltd.)) 8 parts of a curing accelerator are mixed and uniformly mixed with a rotating mixer. As described above, the obtained resin varnish 1 is uniformly applied so that the thickness of the resin composition layer after drying is 40 μm, and the resin composition is coated. Adhesive film 1 was produced by drying the layer.

[Example 2]
10 parts of bixylenol type epoxy resin ("YX4000HK" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 190) and 21 parts of naphthalene type epoxy resin ("HP6000" manufactured by DIC Corporation, epoxy equivalent 260) were used. A resin varnish 2 was prepared in the same manner as in Example 1, and an adhesive film 2 was produced using this.

[Example 3]
Resin varnish 3 was prepared in the same manner as in Example 1, except that 2 parts of 3,3,3-trifluoropropyltrimethoxysilane ("KBM-7103" manufactured by Shin-Etsu Chemical Co., Ltd.) was further used. Adhesive film 3 was produced using.

[Example 4]
30.8 parts of an active ester curing agent (“HPC-8000-65T” manufactured by DIC Corporation, a toluene solution having an active group equivalent of about 223 and containing 65% by mass of non-volatile components), and further containing a triazine skeleton Phenolic curing agent (DIC Corporation "LA-3018-50P", a 2-methoxypropanol solution having a hydroxyl equivalent of about 151 and containing 50% non-volatile components) was used. Same as in Example 1 except that 28 parts were used. Then, a resin varnish 4 was prepared, and an adhesive film 4 was produced using this.

[Example 5]
30.8 parts of an active ester curing agent (“HPC-8000-65T” manufactured by DIC Corporation, a toluene solution having an active group equivalent of about 223 and a non-volatile component of 65% by mass) was added to an active ester curing agent. ("EXB-9416-70BK" manufactured by DIC Corporation, a methyl isobutyl ketone solution having an active group equivalent of about 274 and containing 70% by mass of non-volatile components). Then, a resin varnish 5 was prepared, and an adhesive film 5 was produced using this.

[Example 6]
An active ester curing agent ("HPC-8000-65T" manufactured by DIC Corporation) was added to a naphthalene type curing agent ("SN485" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd., a phenol equivalent of 215, and a non-volatile component of 60% by mass. 33.3 parts of MEK solution containing triazine skeleton) and 18.3 parts of triazine skeleton-containing phenol novolac curing agent (DIC Corporation "LA7054", phenol equivalent of 125, MEK solution containing 60% by mass of non-volatile components) A resin varnish 6 was prepared in the same manner as in Example 1 except that the resin varnish 6 was used, and an adhesive film 6 was produced.

[Example 7]
250 parts of spherical silica (“SO-C2” manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) surface-treated with a phenylaminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.), Resin varnish 7 was prepared in the same manner as in Example 1 except that PTFE particles (“Lubron L-2” manufactured by Daikin Industries, Ltd., average particle size 3 μm) were used in 50 parts, and adhesive film 7 was prepared using this. was made.

[Example 8]
50 parts of spherical silica (“SO-C2” manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) surface-treated with a phenylaminosilane coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.), Resin varnish 8 was prepared in the same manner as in Example 1 except that PTFE particles (“Lubron L-2” manufactured by Daikin Industries, Ltd., average particle size 3 μm) were used in 200 parts, and adhesive film 8 was prepared using this. was made.

[Example 9]
Resin varnish 9 was prepared in the same manner as in Example 1 except that 5 parts of a carbodiimide compound (“V-03” manufactured by Nisshinbo Chemical Co., Ltd., a toluene solution containing 50% by mass of non-volatile components) was additionally used as a curing agent. An adhesive film 9 was produced using this.

[Example 10]
Curing accelerator ("2P4MZ" manufactured by Shikoku Kasei Co., Ltd., 2-phenyl-4-methylimidazole, MEK solution containing 2.5% by mass of non-volatile components), curing accelerator (4-dimethylaminopyridine (DMAP), A resin varnish 10 was prepared in the same manner as in Example 1, except that the MEK solution containing 10% by mass of non-volatile components was changed to 2 parts, and an adhesive film 10 was produced using this resin varnish.

[Comparative Example 1]
Resin having a vinyl group ("OPE-2St 2200" manufactured by Mitsubishi Gas Chemical Co., Ltd., a toluene solution containing 60% by mass of non-volatile components) 40 parts, indene cumarone resin ("H-100" manufactured by Nichinuri Chemical Co., Ltd.) ), 50 parts of toluene, and 20 parts of methyl ethyl ketone were mixed and dissolved by stirring while heating, and then cooled to room temperature. 50 parts of spherical silica (“SO-C2” manufactured by Admatechs Co., Ltd., average particle size 0.5 μm) surface-treated with a phenylaminosilane-based coupling agent (“KBM573” manufactured by Shin-Etsu Chemical Co., Ltd.), and PTFE 50 parts of particles (“Lubron L-2” manufactured by Daikin Industries, Ltd., average particle size 3 μm) were mixed and dispersed with a high-speed rotating mixer.

The resulting mixture was mixed with 6 parts of a 5% by mass toluene solution of dicumyl peroxide ("Percumyl D" manufactured by NOF Corporation) as a radical generator, and mixed uniformly with a rotary mixer to obtain a resin. A varnish 11 was prepared and an adhesive film 11 was produced using this.

[Comparative Example 2]
35 parts of a naphthylene ether type epoxy resin (epoxy equivalent: 250, "HP6000" manufactured by DIC Corporation) and 15 parts of a liquid bisphenol A type epoxy resin ("jER828US" manufactured by Mitsubishi Chemical Corporation, epoxy equivalent: 187) were mixed with methyl ethyl ketone. It was dissolved by stirring while heating to 30 parts, and then cooled to room temperature.

To the resulting solution, 20 parts of a phenoxy resin (Mitsubishi Chemical Co., Ltd. "YX7553BH30", MEK solution containing 30% by mass of non-volatile components), a phenylaminosilane-based coupling agent (Shin-Etsu Chemical Co., Ltd. "KBM573" ) surface-treated crystalline silica (“IMSIL A-8” manufactured by Unimin, average particle size 1.38 μm) was mixed and dispersed with a high-speed rotating mixer. Then, 32 parts of a methyl ethyl ketone solution containing 50% by mass of non-volatile components of a phenol novolac curing agent (DIC Corporation "TD2090", hydroxyl equivalent 105), a triazine skeleton-containing phenol novolac curing agent (DIC Corporation "LA- 7054", a MEK solution having a hydroxyl equivalent of 125 and containing 60% by mass of non-volatile components) 10 parts, 2-phenyl-4-methylimidazole ("2P4MZ" manufactured by Shikoku Kasei Co., Ltd.) as a curing accelerator. 8 parts of a 5 mass % MEK solution was added and uniformly mixed with a rotating mixer to prepare a resin varnish 12, and an adhesive film 12 was produced using this.

Table 1 shows the components used in the resin varnishes according to the above examples and comparative examples. Table 2 shows measured values and evaluations (evaluation of peel strength and evaluation of compatibility between adhesion and electrical properties of the insulating layer) of the examples and comparative examples.

As is clear from Table 2, the insulating layers according to Examples 1 to 10 have Dk(A) and Dk(B) satisfying the formula: Dk(B)≦Dk(A)−0.8, and the inner layer substrate The peel strength of the insulating layer (insulating layer for high-frequency circuits) is 0.5 kgf/cm or more. That is, it was possible to achieve both a reduction in Dk(B) to about 2.5 to 3.1 and excellent adhesion of the insulating layer to the inner layer substrate.

Therefore, even if a relatively inexpensive inner layer substrate is used and it is operated in a high frequency band such as a band of 28 GHz to 80 GHz, stable bonding between the inner layer substrate and the insulating layer can be ensured, and it is suitable for high frequency circuits under the usage environment. To suppress the problem that an insulating layer peels off from an inner layer substrate and stop functioning as a high-frequency circuit board, suppress the deterioration of electrical characteristics over time, and further improve device reliability such as life. can be expected.

On the other hand, according to Comparative Example 1, which does not contain the component (A), the insulating layer swells, and the adhesion is insufficient. It was not possible to achieve both excellent adhesion of the insulating layer.

Further, according to Comparative Example 2, which does not contain the components (D), (E) and (F), the reduction of Dk (B) is insufficient, and the dielectric constant of the insulating layer is reduced and the core substrate, that is, the inner layer It was not possible to achieve both excellent adhesion of the insulating layer to the substrate.

REFERENCE SIGNS LIST 10 high frequency circuit board 12 through hole 12a wiring in through hole 20 inner layer board 20a, 22a first main surface 20b, 22b second main surface 22 core substrate 24 first conductor layer (wiring layer)
26 Second conductor layer (wiring layer)
27 Interlayer insulating layer 28 Third conductor layer (wiring layer)
29, 32, 52 via holes 29a, 32a, 52a wiring in via holes 30 insulating layer for high frequency circuit 40 conductor layer for high frequency circuit (wiring layer)
50 insulating layer 60 conductor layer (wiring layer)

Claims (16)

an inner layer substrate;
A high frequency circuit board comprising a high frequency circuit forming insulating layer bonded to the inner layer substrate,
When Dk(A) is the dielectric constant of the inner layer substrate and Dk(B) is the dielectric constant of the insulating layer for forming a high-frequency circuit, Dk(A) and Dk(B) are represented by the following formula:
Dk(B)≦Dk(A)−0.8
and the peel strength of the insulating layer for forming a high frequency circuit with respect to the inner layer substrate is 0.5 kgf/cm or more,
A resin composition in which the high-frequency circuit-forming insulating layer contains component (A) an epoxy resin and component (B) a curing agent, and (B) a curing agent contains an active ester-based curing agent (however, a cyanate ester-based curing agent ) is a cured body obtained by thermosetting,
A high-frequency circuit board , wherein the resin composition further contains component (E) a resin having an aliphatic hydrocarbon group having a carbon-carbon double bond in the molecule . 2. The high frequency according to claim 1, wherein only one high-frequency circuit-forming insulating layer is provided, or two or more high-frequency-circuit-forming insulating layers are provided on one main surface side of the inner layer substrate. circuit board. 3. The high-frequency circuit board according to claim 1, wherein said insulating layer for forming a high-frequency circuit has a thickness of 20 to 200 μm. The high-frequency circuit board according to any one of claims 1 to 3, wherein the inner layer board has a thickness of 50 to 4000 µm. 5. The high frequency circuit board according to claim 1, wherein said inner layer board includes a glass epoxy board, and said insulating layer for forming a high frequency circuit is bonded to said glass epoxy board. 6. The high-frequency circuit forming insulating layer is bonded to the insulating layer, wherein the inner layer substrate includes one or more insulating layers obtained by curing a material containing an epoxy resin. high frequency circuit board. 7. The high-frequency circuit board according to claim 5, wherein said resin composition further contains component (C) an inorganic filler. 8. The high-frequency circuit board according to claim 7, wherein said resin composition further contains component (D) an organic filler. The component (D) organic filler according to claim 8, which is one or more organic fillers selected from the group consisting of cycloolefin polymer particles, polyphenylene ether particles, polystyrene particles, and fluoropolymer particles. High frequency circuit board. 10. The high-frequency circuit board according to claim 9, wherein said component (D) organic filler is a fluoropolymer particle. The aliphatic hydrocarbon group having a carbon-carbon double bond contained in the component ( E) is selected from the group consisting of an acrylic group, a methacrylic group, a styryl group, an allyl group, a vinyl group, and a propenyl group. The high-frequency circuit board according to any one of claims 1 to 10 , wherein : The high-frequency circuit board according to any one of claims 9 to 11, wherein the resin composition further contains component (F) an indene cumarone resin. 13. The high frequency circuit board according to claim 12, wherein said resin composition further contains component (H) a silane compound. The high-frequency circuit board according to any one of claims 1 to 13, wherein said Dk(A) is 4.0 or more. The high-frequency circuit board according to any one of claims 1 to 14, wherein said Dk(B) is 3.5 or less. 16. The high-frequency circuit board according to claim 15, wherein said Dk(B) is 3.0 or less.

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