JP7108894B2 - Metal-clad laminates, resin-coated metal foils, and wiring boards - Google Patents

Description

TECHNICAL FIELD The present invention relates to a metal-clad laminate, a resin-coated metal foil, and a wiring board.

With the increase in the amount of information processed in various electronic devices, mounting techniques such as higher integration of semiconductor devices mounted thereon, higher wiring density, and multi-layering are progressing rapidly. Moreover, wiring boards used in various electronic devices are required to be high-frequency compatible wiring boards, such as millimeter-wave radar boards for in-vehicle applications.

When a signal is transmitted through wiring provided on a wiring board, transmission loss due to conductors forming the wiring, transmission loss due to dielectrics around the wiring, and the like occur. It is known that these transmission losses are particularly likely to occur when high-frequency signals are transmitted through wiring provided on a wiring board. For this reason, wiring boards are required to reduce loss during signal transmission in order to increase the signal transmission speed. This is especially required for high-frequency wiring boards. In order to meet this demand, it is conceivable to use a material with a low dielectric constant and a low dielectric loss tangent as a substrate material for manufacturing an insulating layer that constitutes a wiring board.

An example of a metal-clad laminate intended to reduce loss during signal transmission is the metal-clad laminate described in Patent Document 1.

Patent Document 1 discloses an insulating layer containing a polyphenylene ether compound and cured, a metal layer bonded to the insulating layer, and an intermediate layer containing a silane compound interposed between the insulating layer and the metal layer. , the metal-clad laminate, wherein the metal layer has a bonding surface bonded to the insulating layer via the intermediate layer, and the bonding surface has a ten-point average roughness Rz of 0.5 μm or more and 4 μm or less. ing. Patent Document 1 discloses that a metal-clad laminate can be obtained from which a printed wiring board with reduced loss during signal transmission can be manufactured.

JP 2016-28885 A

As described above, wiring boards such as printed wiring boards are required to reduce loss during signal transmission in order to increase the signal transmission speed. Therefore, in order to reduce loss during signal transmission in a wiring board, it is required to use a material with excellent low dielectric properties such as a low dielectric constant and a low dielectric loss tangent as a substrate material.

Moreover, in a wiring board on which electronic components and the like are mounted at high density, the amount of heat generated per unit area increases. In order to reduce the occurrence of problems due to the increase in the amount of heat generated, it is conceivable to improve the heat dissipation of the wiring board. In order to meet this demand, it is conceivable to use a material with high thermal conductivity as a substrate material for manufacturing the insulating layer that constitutes the wiring board. The wiring board uses a material with a low dielectric constant and dielectric loss tangent as a substrate material, and uses a material with high thermal conductivity not only to reduce loss during signal transmission, but also to improve the heat dissipation of the wiring board. is also required.

Then, in order to increase the thermal conductivity, it is conceivable to add silica particles to the substrate material for manufacturing the insulating layer constituting the wiring board and increase the content. However, when trying to achieve the required thermal conductivity by increasing the content of silica particles, problems may occur due to the excessive content of silica particles. Specifically, the adhesive force between the metal foil and the insulating layer in the metal-clad laminate is lowered. As a result, peeling of the metal foil may occur during heating, and the heat resistance of the metal-clad laminate tends to be insufficient. Excellent metal foil adhesion is required to prevent such delamination.

On the other hand, it is conceivable to use silica particles surface-treated with a silane coupling agent as the silica particles, but this increases the cost, making it difficult to meet the price demand for cost reduction of the final product. Under these circumstances, the silica particles to be used should have a metal foil adhesiveness that does not cause peeling of the metal foil even when heated, regardless of whether or not the surface is treated with a silane coupling agent. There is a demand for metal-clad laminates with high elongation. In particular, it is known that when silica particles that have not been surface-treated with a silane coupling agent are used, the adhesion between the metal foil and the insulating layer tends to decrease as described above. On the other hand, it is known that the adhesive strength between the metal foil and the insulating layer in the metal-clad laminate can be improved to some extent by mixing a silane coupling agent into the resin composition used, that is, by so-called integral blending. However, it has not been easy to prevent the adhesive force between the metal foil and the insulating layer from deteriorating.

Wiring boards used in various electronic devices are also required to be less susceptible to changes in the external environment. For example, as described above, high metal foil adhesiveness is required so that peeling of the metal foil can be suppressed even during heating. In addition, high moisture resistance is required so that the occurrence of peeling of the metal foil can be suppressed even if the wiring board absorbs moisture so that the wiring board can be used even in a high-humidity environment. In addition, in order to respond to the development of mounting technology such as higher integration of semiconductor devices, higher wiring density, and multilayering, we have developed a high-quality material that can suppress the peeling of metal foil during desmear processing and repair. Chemical resistance is also required.

The present invention has been made in view of such circumstances, and provides a metal-clad laminate having low dielectric constant and dielectric properties, high thermal conductivity, excellent metal foil adhesion, moisture resistance, and chemical resistance. , a resin-coated metal foil, and a wiring board.

As a result of various studies, the inventors of the present invention have found that the above object can be achieved by the present invention described below.

A metal-clad laminate according to an aspect of the present invention comprises an insulating layer and a metal foil present in contact with at least one surface of the insulating layer, the insulating layer comprising a styrene-butadiene copolymer, A cured product of a resin composition containing a first silane coupling agent having a carbon-carbon unsaturated double bond in the molecule and silica particles, wherein the metal foil has a contact surface with the insulating layer, It is characterized in that it is surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in its molecule.

Further, in the metal-clad laminate, the deterioration rate of the peel strength of the metal foil in the metal-clad laminate after acid treatment with respect to the peel strength of the metal foil in the metal-clad laminate before acid treatment is It is preferably 15% or less.

Further, in the metal-clad laminate, the deterioration rate of the peel strength of the metal foil in the metal-clad laminate after the moisture absorption treatment with respect to the peel strength of the metal foil in the metal-clad laminate before the moisture absorption treatment is It is preferably 10% or less.

Moreover, in the metal-clad laminate, the first silane coupling agent preferably has at least one functional group selected from the group consisting of methacryloxy groups, styryl groups, vinyl groups, and acryloxy groups.

In addition, a resin-coated metal foil according to another aspect of the present invention includes a resin layer and a metal foil present in contact with at least one surface of the resin layer, wherein the resin layer is made of styrene-butadiene copolymer. A polymer, a first silane coupling agent having a carbon-carbon unsaturated double bond in the molecule, and a resin composition containing silica particles or a semi-cured material of the resin composition, wherein the metal foil is A contact surface with the insulating layer is surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in the molecule.

Further, a wiring board according to another aspect of the present invention includes an insulating layer and wiring present in contact with at least one surface of the insulating layer, wherein the insulating layer comprises a styrene-butadiene copolymer and , a first silane coupling agent having a carbon-carbon unsaturated double bond in the molecule, and a cured product of a resin composition containing silica particles, wherein the wiring has a contact surface with the insulating layer, It is characterized in that it is surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in its molecule.

According to the present invention, a metal-clad laminate, a resin-coated metal foil, and a wiring board having low dielectric constant and dielectric properties, high thermal conductivity, and excellent metal foil adhesion, moisture resistance, and chemical resistance are provided. can provide.

FIG. 1 is a cross-sectional view showing the configuration of a metal-clad laminate according to one embodiment of the present invention. FIG. 2 is a cross-sectional view showing the configuration of a resin-coated metal foil according to another embodiment of the present invention. FIG. 3 is a cross-sectional view showing the configuration of a wiring board according to another embodiment of the invention.

Embodiments according to the present invention will be described below, but the present invention is not limited to these.

[Metal clad laminate]
A metal-clad laminate according to one embodiment of the present invention comprises an insulating layer and a metal foil present in contact with at least one surface of the insulating layer. As shown in FIG. 1, this metal-clad laminate 11 includes an insulating layer 12 and metal foils 13 arranged so as to be in contact with both surfaces thereof. Also, the metal-clad laminate may have a metal foil in contact with only one surface of the insulating layer. FIG. 1 is a cross-sectional view showing the configuration of a metal-clad laminate 11 according to this embodiment.

The insulating layer 12 includes a cured resin composition containing a styrene-butadiene copolymer, a first silane coupling agent having a carbon-carbon unsaturated double bond in the molecule, and silica particles. The resin composition may contain the styrene-butadiene copolymer and may further contain the first silane coupling agent and the silica particles, or the silica particles may be combined with the first silane coupling agent. It may contain surface-treated silica particles surface-treated with an agent.

The insulating layer 12 is not particularly limited as long as it is a layer containing a cured product of the resin composition. The insulating layer 12 may be, for example, a layer composed only of the cured resin composition, or a layer containing not only the cured resin composition but also a fibrous base material. . By including a fibrous base material, the insulating layer 12 can enhance its strength, heat resistance, and the like. Specifically, the insulating layer containing the fibrous base material is obtained by impregnating the fibrous base material with the resin composition and curing the resin composition impregnated in the fibrous base material. and the like.

The contact surface 16 of the metal foil 13 with the insulating layer 12 is surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in its molecule. Specifically, the metal foil 13 includes a metal foil substrate 14 and a surface treatment layer 15 provided at least on the contact surface 16 side of the metal foil substrate 14 with the insulating layer 12 .

Such a metal-clad laminate has a low dielectric constant and dielectric properties, a high thermal conductivity, and excellent metal foil adhesion, moisture resistance, and chemical resistance. This is believed to be due to the following.

Since the cured product contained in the insulating layer is obtained by curing a resin composition containing a styrene-butadiene copolymer, the dielectric constant and dielectric loss tangent are low. Furthermore, since the resin composition also contains silica particles, it is thought that the thermal conductivity of the cured product of the resin composition can be enhanced. The resin composition contains a first silane coupling agent having a carbon-carbon unsaturated double bond in its molecule. As the metal foil that contacts the insulating layer containing the cured product of the resin composition, a metal foil surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in the molecule is used. The metal foil and the It is thought that the adhesive strength with the insulating layer is increased. From this, it is considered that even if the obtained metal-clad laminate is heated, the metal foil adhesion is high such that the occurrence of peeling of the metal foil is suppressed. Furthermore, it is expected that the metal-clad laminate obtained will have high moisture resistance and chemical resistance, such that the metal foil will be prevented from peeling off, whether it is subjected to moisture absorption treatment or treatment with chemicals such as acids. Conceivable.

(resin composition)
The resin composition used in this embodiment contains the styrene-butadiene copolymer, the first silane coupling agent, and the silica particles, as described above.

(styrene-butadiene copolymer)
The styrene-butadiene copolymer used in this embodiment is not particularly limited as long as it is a styrene-butadiene copolymer that can be used as a resin contained in an insulating layer provided in a metal-clad laminate or a wiring board.

The styrene-butadiene copolymer is a copolymer of styrene and butadiene, such as a copolymer of styrene and 1,3-butadiene. Also, the styrene-butadiene copolymer may be a random copolymer or a block copolymer. The block copolymer may be, for example, a styrene-butadiene binary copolymer or a styrene-butadiene-styrene terpolymer.

Specifically, the styrene-butadiene copolymer includes a styrene-derived unit represented by the following formula (1) and a 1,2-bonded butadiene-derived unit represented by the following formula (2) (1, 2-adduct) and a 1,4-bonded butadiene-derived unit represented by the following formula (3) (1,4-adduct) in the molecule. Further, in this copolymer, the content of the styrene-derived units is preferably 3 to 25% by mass, more preferably 5 to 20% by mass, based on the total amount of the styrene-butadiene copolymer. preferable. If the styrene-derived units are too small, the stability of the styrene-butadiene copolymer tends to decrease. In addition, when the styrene-derived units are too large, the compatibility in the resin composition decreases, and the styrene-butadiene copolymer tends to separate in the resin composition or tends to be easily tacked when made into a prepreg. There is Also, the content of the 1,2-adduct is preferably 5 to 30% by mass, more preferably 7 to 25% by mass, based on the total amount of the styrene-butadiene copolymer. If the amount of the 1,2-adduct is too small, the compatibility in the resin composition decreases, and the styrene-butadiene copolymer separates in the resin composition, and tacking tends to occur when the prepreg is formed. Tend. On the other hand, when the 1,2-adduct is too much, the stability of the styrene-butadiene copolymer tends to decrease. Also, the content of the 1,4-adduct is preferably 1 to 15% by mass, more preferably 2 to 14% by mass, based on the total amount of the styrene-butadiene copolymer. If the amount of the 1,4-adduct is too small, the compatibility in the resin composition decreases, and the styrene-butadiene copolymer separates in the resin composition, and tacking tends to occur when the prepreg is formed. Tend. On the other hand, when the 1,4-adduct is too much, the stability of the styrene-butadiene copolymer tends to decrease. In addition, the repeating number of the styrene-derived unit, the 1,2-adduct, and the 1,4-adduct satisfies the following relationship between the molecular weight of the styrene-butadiene copolymer and the content of each unit. is preferably

The molecular weight of the styrene-butadiene copolymer is not particularly limited. If the molecular weight of the styrene-butadiene copolymer is too low, the heat resistance of the cured product tends to be lowered. When the molecular weight of the styrene-butadiene copolymer is too high, the moldability tends to deteriorate. Therefore, when the molecular weight of the styrene-butadiene copolymer is within the above range, the cured product is not only excellent in heat resistance but also excellent in moldability. Here, the weight-average molecular weight may be measured by a general molecular weight measurement method, and specifically includes a value measured using gel permeation chromatography (GPC).

(First silane coupling agent)
The first silane coupling agent used in the present embodiment is not particularly limited as long as it is a silane coupling agent having a carbon-carbon unsaturated double bond in its molecule. Specific examples of this silane coupling agent include silane coupling agents having at least one functional group selected from the group consisting of a methacryloxy group, a styryl group, a vinyl group, and an acryloxy group. That is, the silane coupling agent has at least one of a methacryloxy group, a styryl group, a vinyl group, and an acryloxy group as a reactive functional group, and further has a hydrolyzable group such as a methoxy group or an ethoxy group. and the like compounds having Examples of the first silane coupling agent having a methacryloxy group include 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-methacryloxy propylmethyldiethoxysilane, 3-methacryloxypropylethyldiethoxysilane, and the like. Examples of the first silane coupling agent having a styryl group include p-styryltrimethoxysilane and p-styryltriethoxysilane. Examples of the first silane coupling agent include those having a vinyl group, such as vinyltriethoxysilane and vinyltrimethoxysilane. Examples of the first silane coupling agent having an acryloxy group include 3-acryloxypropyltrimethoxysilane and 3-acryloxypropyltriethoxysilane.

The first silane coupling agent includes the first silane coupling agent contained in the resin composition and the first silane coupling agent contained in the silica particles surface-treated with the first silane coupling agent. and The first silane coupling agent contained in the resin composition and the first silane coupling agent contained in the silica particles surface-treated with the first silane coupling agent are each carbon-carbon unsaturated. Any silane coupling agent having a double bond in the molecule may be used, and may be the same silane coupling agent or different silane coupling agents.

(silica particles)
The silica particles used in the present embodiment are not particularly limited, and may be surface-treated silica particles or non-surface-treated silica particles. Moreover, as said silica particle, what is called spherical silica etc. are mentioned. Examples of the surface treatment include treatment with a silane coupling agent. The surface-treated silica particles may be silica particles surface-treated with the first silane coupling agent. That is, the resin composition contains either the silica particles or the silica particles surface-treated with the first silane coupling agent. Further, when the resin composition is produced, the silica particles may be previously surface-treated with the first silane coupling agent, or the silica particles and the first silane coupling agent may be integrated. It may be added by the Lublende method.

(Content)
The total content of the silica particles and the silica particles surface-treated with the first silane coupling agent is preferably 150 to 400 parts by mass with respect to 100 parts by mass of the styrene-butadiene copolymer. It is more preferably up to 350 parts by mass, and even more preferably 200 to 320 parts by mass. This total content is the content of the silica particles when only the silica particles are used, and when only the surface-treated silica particles obtained by surface-treating the silica particles in advance with the first silane coupling agent are used. is the content of the surface-treated silica particles. If the total content is too small, the thermal conductivity of the metal-clad laminate tends to be insufficiently increased. On the other hand, when the total content is too large, it tends to be difficult to obtain excellent low dielectric properties and the adhesion to metal foil tends to decrease. Therefore, by setting the total content within the above range, it is possible to increase thermal conductivity while maintaining excellent low dielectric properties, metal foil adhesion, moisture resistance, and chemical resistance.

The content of the styrene-butadiene copolymer is preferably within the content range derived from the total content range of the silica particles and the silica particles surface-treated with the first silane coupling agent. That is, the content of the styrene-butadiene copolymer is preferably 10 to 50 parts by mass, more preferably 15 to 45 parts by mass, with respect to the total content of 100 parts by mass. It is more preferably 40 parts by mass.

The content of the first silane coupling agent is 0.1 to 10 parts by mass with respect to a total of 100 parts by mass of the silica particles and the silica particles surface-treated with the first silane coupling agent. is preferable, 0.3 to 7 parts by mass is more preferable, and 0.5 to 5 parts by mass is even more preferable. The content of the first silane coupling agent here refers to the content of the first silane coupling agent contained in the resin composition, and the content of the first silane coupling agent contained in the silica particles surface-treated with the first silane coupling agent. is the total content of the first silane coupling agent used. That is, the content of the first silane coupling agent here is the first silane coupling agent when the silica particles and the first silane coupling agent are added by an integral blend method, and the first It is the total content of the first silane coupling agent contained in the silica particles surface-treated with the silane coupling agent. If the content of the first silane coupling agent is too small, the metal foil adhesion, moisture resistance, and chemical resistance tend to deteriorate. Specifically, the adhesion between the metal foil and the insulating layer is reduced, and the metal foil tends to peel off when heated. On the other hand, when the content of the first silane coupling agent is too large, it is difficult to obtain excellent low dielectric properties, and there is a tendency for metal foil adhesion, moisture resistance, and chemical resistance to decrease. Therefore, by setting the content of the first silane coupling agent within the above range, excellent low dielectric properties, metal foil adhesion, moisture resistance, and resistance can be achieved even if the thermal conductivity is increased by the inclusion of silica particles. It can maintain its chemical properties.

(other ingredients)
The resin composition according to the present embodiment may optionally contain components other than the styrene-butadiene copolymer, the first silane coupling agent, and the silica particles (other component) may be contained. Other components contained in the resin composition according to the present embodiment include, for example, an initiator, a flame retardant, a dispersant, a silane coupling agent other than the first silane coupling agent, and an inorganic filler other than silica particles. Additives such as fillers, defoamers, antioxidants, heat stabilizers, antistatic agents, UV absorbers, dyes and pigments, and lubricants may also be included. In addition to the styrene-butadiene copolymer, the resin composition may contain resins such as polyphenylene ether, epoxy resin, unsaturated polyester resin, and thermosetting polyimide resin.

The resin composition according to the present embodiment may contain an initiator (reaction initiator) as described above. The curing reaction can proceed even if the resin composition does not contain an initiator. Depending on the process conditions, it may be difficult to raise the temperature until curing proceeds, so an initiator may be added. The initiator is not particularly limited as long as it can accelerate the curing reaction of the styrene-butadiene copolymer. Specifically, for example, α,α'-di(t-butylperoxy)diisopropylbenzene, 2,5-dimethyl-2,5-di(t-butylperoxy)-3-hexyne, benzoyl peroxide, 3,3′,5,5′-tetramethyl-1,4-diphenoquinone, chloranil, 2,4,6-tri-t-butylphenoxyl, t-butylperoxyisopropyl monocarbonate, and azobisisobutyronitrile and other oxidizing agents. Moreover, carboxylic acid metal salt etc. can be used together as needed. By doing so, the curing reaction can be further accelerated. Among these, α,α'-di(t-butylperoxy)diisopropylbenzene is preferably used. Since α,α'-di(t-butylperoxy)diisopropylbenzene has a relatively high reaction initiation temperature, it is possible to suppress the acceleration of the curing reaction at a time when curing is not necessary, such as when the prepreg is dried. , the deterioration of the storage stability of the resin composition can be suppressed. Furthermore, since α,α'-di(t-butylperoxy)diisopropylbenzene has low volatility, it does not volatilize during drying or storage of the prepreg and has good stability. Moreover, the reaction initiator may be used alone or in combination of two or more. When the initiator is contained, the content is preferably 5 parts by mass or less, more preferably 0.5 to 3 parts by mass, with respect to 100 parts by mass of the styrene-butadiene copolymer. .

The resin composition according to this embodiment may contain a flame retardant as described above. By containing a flame retardant, the flame retardancy of the cured product of the resin composition can be enhanced. The flame retardant is not particularly limited. Specifically, in the field of using halogen-based flame retardants such as brominated flame retardants, for example, ethylene dipentabromobenzene, ethylenebistetrabromoimide, decabromodiphenyl oxide, and tetradecabromo, which have a melting point of 300° C. or higher Diphenoxybenzene is preferred. By using a halogen-based flame retardant, desorption of halogen at high temperatures can be suppressed, and it is thought that a decrease in heat resistance can be suppressed. Further, in fields where halogen-free is required, phosphate ester-based flame retardants, phosphazene-based flame retardants, bisdiphenylphosphine oxide-based flame retardants, and phosphinate-based flame retardants can be used. Specific examples of the phosphate flame retardant include condensed phosphate of dixylenyl phosphate. A specific example of the phosphazene-based flame retardant is phenoxyphosphazene. Specific examples of bisdiphenylphosphine oxide flame retardants include xylylenebisdiphenylphosphine oxide. Specific examples of phosphinate-based flame retardants include metal phosphinates of aluminum dialkylphosphinates. As the flame retardant, each of the exemplified flame retardants may be used alone, or two or more thereof may be used in combination.

The resin composition according to this embodiment may contain a dispersant as described above. The dispersant is not particularly limited, but includes, for example, a dispersant having an acidic group and a basic group, that is, an amphoteric dispersant. This dispersant may be a dispersant having an acidic group and a basic group in one molecule, or a dispersant in which a molecule having an acidic group and a molecule having a basic group coexist. may be Moreover, the dispersant should have an acidic group and a basic group, and may have other functional groups, for example. Other functional groups include, for example, hydrophilic functional groups such as hydroxyl groups. As the dispersant, specifically, a dispersant having a phosphate group and an imidazoline group and a dispersant having a carboxyl group and an amino group are preferably used. Further, as a dispersant having a phosphate group and an imidazoline group, BYK-W969 manufactured by BYK-Chemie Japan Co., Ltd. and the like can be mentioned. Further, as a dispersing agent having a carboxyl group and an amino group, BYK-W966 manufactured by BYK-Chemie Japan Co., Ltd. can be used.

(metal foil)
The metal foil has a contact surface with the insulating layer that is surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in the molecule. That is, the metal foil includes a metal foil base material and a surface treatment layer provided on at least the contact surface side of the metal foil base material with the insulating layer. As shown in FIG. 1, the metal foil 13 includes a metal foil base material 14 and a surface treatment layer 15 provided on the contact surface 16 side of the metal foil base material 14 with the insulating layer 12. things are mentioned. The surface-treated layer 15 is a layer obtained by surface-treating the metal foil substrate 14 with the second silane coupling agent. That is, the metal foil 13 is obtained by surface-treating the metal foil substrate 14 and at least the contact surface 16 side of the metal foil substrate 14 with the insulating layer 12 with the second silane coupling agent. and a surface treatment layer 15 . Moreover, the surface treatment layer 15 is preferably a layer provided on at least the entire surface of the contact surface 16 with the insulating layer 12 of the metal foil base material 14 . Moreover, the metal foil may be provided with the surface treatment layer on both sides of the metal foil base material. In addition, the metal-clad laminate is obtained, for example, by laminating the metal foil on both or one side of the prepreg forming the insulating layer so that the prepreg and the surface treatment layer of the metal foil are in contact with each other. Manufactured by heating and pressurizing. Accordingly, examples of the insulating layer include a layer obtained by curing a prepreg that is in contact with the surface treatment layer of the metal foil. In this case, the surface treatment layer may be formed as a layer reacting with the resin composition contained in the prepreg. It is preferably a layer reacting with. Such a layer enhances the adhesion between the metal foil and the insulating layer.

Also, the metal foil 13 is in contact with the insulating layer 12 . That is, the surface treatment layer 15 of the metal foil 13 is in contact with the insulating layer 12 . In addition, when a wiring board is manufactured from the metal-clad laminate 11, the metal foil 13 becomes wiring in the wiring board.

The second silane coupling agent is not particularly limited as long as it is a silane coupling agent having an amino group composed of an aliphatic amine in its molecule. Examples of the second silane coupling agent include compounds having an amino group composed of an aliphatic amine as a reactive functional group and further having a hydrolyzable group such as a methoxy group or an ethoxy group. Specific examples of the second silane coupling agent include N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldiethoxysilane, N- 2-(aminoethyl)-3-aminopropylethyldiethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, and the like. Among these, 3-aminopropyltriethoxysilane is preferred.

The metal foil 13 in contact with the insulating layer 12 can be enhanced in adhesion to the insulating layer 12 by the surface treatment layer 15 formed by surface-treating the metal substrate 14 with the second silane coupling agent. can.

In addition, the surface roughness of the metal foil 13 (surface roughness of the contact surface 16) is preferably 3 μm or less, preferably 2.5 μm or less, and preferably 2 μm or less in ten-point average roughness Rz. It is more preferable to have The lower the surface roughness of the contact surface 16, that is, the higher the smoothness of the metal foil 13, the better, since loss during signal transmission can be reduced. On the other hand, even if the surface roughness of the contact surface 16 is low, the ten-point average roughness Rz is limited to about 0.5 μm. Also, if the surface roughness of the contact surface 16 is too low, the adhesiveness between the metal foil 13 and the insulating layer 12 tends to deteriorate. From this point of view as well, the surface roughness of the contact surface 16 is preferably 0.5 μm or more in ten-point average roughness Rz. Therefore, the surface roughness of the contact surface 16 is preferably 0.5 to 3 μm, more preferably 0.6 to 2.5 μm, more preferably 0.6 to 2 μm in ten-point average roughness Rz. It is even more preferable to have In addition, since the metal foil 13 includes the metal foil base material 14 and the surface treatment layer 15 on the contact surface 16 side of the metal foil base material 14, the surface roughness of the contact surface 16 is the same as described above. It is the surface roughness of the surface treatment layer 15 . Moreover, the surface roughness of the metal foil base material 14 is not particularly limited. If the surface roughness of the metal foil 13 does not change greatly even if the surface treatment layer 15 is formed, the surface roughness of the metal foil substrate 14 is equivalent to the surface roughness of the contact surface 16. Preferably. The ten-point average roughness Rz, which is the surface roughness here, conforms to JIS B 0601:1994, and can be measured with a general surface roughness measuring instrument or the like. Specifically, for example, it can be measured using a surface roughness profiler (SURFCOM500DX) manufactured by Tokyo Seimitsu Co., Ltd.

Moreover, the metal foil substrate 14 is not particularly limited as long as it is used as a metal foil for a metal-clad laminate. Specifically, examples of the metal foil substrate 14 include metal foils such as copper foil, nickel foil, and aluminum foil. Among these, copper foil is preferably used as the metal foil substrate 14 . That is, the metal-clad laminate according to this embodiment is preferably a copper foil-clad laminate.

Moreover, the thickness of the metal foil 13 is not particularly limited, and varies depending on the performance required for the finally obtained wiring board. The thickness of the metal foil 13 is preferably 12 to 70 μm, for example.

The metal-clad laminate according to the present embodiment compares the peel strength (peel strength before acid treatment) of the metal foil in the metal-clad laminate before acid treatment with the metal in the metal-clad laminate after acid treatment. Deterioration rate of foil peeling strength (peeling strength after acid treatment) [= (peeling strength before acid treatment - peeling strength after acid treatment) / peeling strength before acid treatment x 100] is 15% or less. is preferred, and 7% or less is more preferred. The deterioration rate is preferably as low as possible, and the deterioration rate is preferably 0%. Therefore, the deterioration rate is preferably 0 to 15%, more preferably 0 to 7%. In general, when a metal-clad laminate is subjected to an acid treatment, the peel strength of the metal foil tends to decrease. In contrast, in the metal-clad laminate according to the present embodiment, even after the acid treatment, the metal foil is less likely to peel off to such an extent that the deterioration rate is within the above range. That is, the metal-clad laminate according to this embodiment is excellent in chemical resistance such as acid resistance. In addition, as a method for measuring the peeling strength of the metal foil, for example, the same method as the method for measuring the copper foil adhesive strength described later can be used. Examples of the acid treatment include a treatment of immersing the metal-clad laminate in hydrochloric acid.

In the metal-clad laminate according to the present embodiment, the metal foil in the metal-clad laminate after moisture absorption treatment is compared with the peel strength of the metal foil in the metal-clad laminate before moisture absorption treatment (peeling strength before moisture absorption treatment). Degradation rate of foil peeling strength (peeling strength after moisture absorption treatment) [= (peeling strength before moisture absorption treatment - peeling strength after moisture absorption treatment) / peeling strength before moisture absorption treatment x 100] is 10% or less. is preferred, and 7% or less is more preferred. The deterioration rate is preferably as low as possible, and the deterioration rate is preferably 0%. Therefore, the deterioration rate is preferably 0 to 10%, more preferably 0 to 7%. In general, when a metal-clad laminate is subjected to moisture absorption treatment, the peel strength of the metal foil tends to decrease. In contrast, in the metal-clad laminate according to the present embodiment, even after the moisture absorption treatment, the metal foil is less likely to peel off to such an extent that the deterioration rate is within the above range. That is, the metal-clad laminate according to this embodiment has excellent moisture resistance. In addition, as a method for measuring the peeling strength of the metal foil, for example, the same method as the method for measuring the copper foil adhesive strength described later can be used. Examples of the hygroscopic treatment include immersing the metal-clad laminate in warm water.

The resin composition used in this embodiment may be prepared in the form of a varnish before use. For example, it may be prepared in the form of a varnish and used for the purpose of impregnating the base material (fibrous base material) for forming the prepreg when producing the prepreg. That is, the resin composition may be used as a varnish (resin varnish). Moreover, in the resin composition used in the present embodiment, the modified polyphenylene ether compound and the cross-linking curing agent are dissolved in a resin varnish. Such a varnish-like composition (resin varnish) is prepared, for example, as follows.

First, each component that can be dissolved in an organic solvent is put into the organic solvent and dissolved. At this time, it may be heated, if necessary. After that, a component that is insoluble in an organic solvent, which is used as necessary, is added, and dispersed using a ball mill, bead mill, planetary mixer, roll mill, or the like until a predetermined dispersed state is obtained, thereby forming a varnish-like composition. things are prepared. The organic solvent used here is not particularly limited as long as it dissolves the styrene-butadiene copolymer and does not inhibit the curing reaction. Specific examples include toluene and methyl ethyl ketone (MEK).

Moreover, as described above, the insulating layer may contain not only the cured product of the resin composition but also a fibrous base material. Examples of the fibrous base material include those similar to the fibrous base material contained in the prepreg described later.

Moreover, by using the resin composition, not only the metal-clad laminate but also a prepreg, a resin-coated metal foil, and a wiring board can be obtained as follows. At this time, a varnish-like composition as described above may be used as the resin composition.

The prepreg comprises a semi-cured material of the resin composition and a fibrous base material. The prepreg includes a fibrous base material in the semi-cured material. That is, this prepreg comprises the semi-cured material and a fibrous base material present in the semi-cured material.

The semi-cured product is a state in which the resin composition is partially cured to the extent that it can be further cured. That is, the semi-cured product is a semi-cured resin composition (B-staged). For example, when a resin composition is heated, the viscosity of the resin composition first gradually decreases, and thereafter, curing starts and the viscosity gradually increases. In such a case, semi-curing includes the state between when the viscosity starts to rise and before it is completely cured.

The prepreg may be a semi-cured product of the resin composition as described above, or may be the uncured resin composition itself. That is, it may be a prepreg comprising a semi-cured product of the resin composition (the resin composition in the B stage) and a fibrous base material, or the resin composition before curing (the resin composition in the A stage). and a fibrous base material.

The method for manufacturing the prepreg is not particularly limited as long as it is a method capable of manufacturing the prepreg. Examples thereof include a method of impregnating a fibrous base material with a resin composition, for example, a resin composition prepared in the form of a varnish. That is, examples of the prepreg include those obtained by impregnating a fibrous base material with the resin composition. The impregnation method is not particularly limited as long as it is a method capable of impregnating the fibrous base material with the resin composition. For example, not only dipping, but also methods using rolls, die coating, and bar coating, spraying, and the like can be mentioned. Moreover, as a method for producing the prepreg, after the impregnation, the fibrous base material impregnated with the resin composition may be dried or heated. That is, as a method for producing a prepreg, for example, a method of impregnating a fibrous base material with a resin composition prepared in the form of varnish and then drying the resin composition prepared in the form of varnish is applied to a fibrous base material. Examples include a method of impregnating and then heating, and a method of impregnating a fibrous base material with a resin composition prepared in the form of a varnish, drying and then heating.

Specific examples of the fibrous base material used in producing the prepreg include glass cloth, aramid cloth, polyester cloth, glass nonwoven fabric, aramid nonwoven fabric, polyester nonwoven fabric, pulp paper, and linter paper. . When glass cloth is used, a laminate having excellent mechanical strength can be obtained, and flattened glass cloth is particularly preferable. Specifically, the flattening process can be carried out, for example, by continuously pressurizing the glass cloth with press rolls at an appropriate pressure to flatten the yarn. As for the thickness of the fibrous base material, for example, one with a thickness of 0.04 to 0.3 mm can be generally used.

The impregnation of the fibrous base material with the resin composition is performed by dipping, coating, or the like. This impregnation can be repeated multiple times if desired. In this case, it is also possible to repeat the impregnation using a plurality of resin compositions having different compositions and concentrations to finally adjust the desired composition and impregnation amount.

The fibrous base material impregnated with the resin composition is heated under desired heating conditions, for example, at 80 to 180° C. for 1 to 10 minutes, before curing (A stage) or in a semi-cured state (B stage). of prepreg is obtained.

The method for producing the metal-clad laminate according to the present embodiment is not particularly limited as long as the metal-clad laminate can be produced. As a method for producing the metal-clad laminate, for example, the metal-clad laminate can be obtained in the same manner as in a general method for producing a metal-clad laminate, except that the resin composition is used. For example, the method of using the said prepreg using the said resin composition, etc. are mentioned. As a method for producing a metal-clad laminate using prepreg, one or more prepregs are stacked, and the surface treatment layer of the metal foil and the prepreg are in contact with each other on both upper and lower surfaces. , a method of laminating and integrating the metal foils by stacking them and heat-pressing them. That is, the method for producing the metal-clad laminate includes the steps of obtaining the resin composition, impregnating a fibrous base material with the resin composition to obtain a prepreg, and laminating a metal foil on the prepreg. a step of obtaining a metal-clad laminate comprising an insulating layer containing a cured product of the resin composition and a metal foil present in contact with at least one surface of the insulating layer, by heating and pressurizing. Prepare. By this method, a metal-clad laminate having metal foil on both sides or a metal-clad laminate having metal foil on one side can be produced. That is, the metal-clad laminate according to the present embodiment is obtained by laminating the metal foil on the prepreg so that the surface treatment layer of the metal foil and the prepreg are in contact with each other, followed by heat and pressure molding. It is a thing. Moreover, the heating and pressurizing conditions can be appropriately set depending on the thickness of the laminate to be produced, the type of resin composition contained in the prepreg, and the like. For example, the temperature can be 170-210° C., the pressure can be 3.5-4 MPa, and the time can be 60-150 minutes. Also, the metal-clad laminate may be produced without using the prepreg. For example, a method of applying a varnish-like resin composition or the like on the surface treatment layer of the metal foil, forming a layer containing a curable composition on the surface treatment layer of the metal foil, and then applying heat and pressure. is mentioned.

Such a metal-clad laminate has a low dielectric constant and dielectric properties, a high thermal conductivity, and excellent metal foil adhesion, moisture resistance, and chemical resistance.

[Metal foil with resin]
A resin-coated metal foil according to another embodiment of the present invention includes a resin layer and a metal foil present in contact with one surface of the resin layer. As shown in FIG. 2, the resin-coated metal foil 21 includes a resin layer 22 and a metal foil 13 arranged so as to be in contact with one surface of the resin layer 22 . FIG. 2 is a cross-sectional view showing the configuration of the resin-coated metal foil 21 according to this embodiment.

The resin layer 22 includes the resin composition (the resin composition in the A stage) or a semi-cured product of the resin composition (the resin composition in the B stage) as described above. . The resin layer may contain the resin composition or a semi-cured material of the resin composition, and may or may not contain a fibrous base material. As the fibrous base material, the same fibrous base material as that of the prepreg can be used.

The metal foil 13 is the same as the metal foil provided in the metal-clad laminate. Specifically, as shown in FIG. 2, the metal foil 13 is provided on a metal foil substrate 14 and a contact surface 16 of the metal foil substrate 14 at least on the side of the contact surface 16 with the resin layer 12. and a surface treatment layer 15 . The surface treatment layer 15 is a layer obtained by surface-treating the metal foil base material 14 with the second silane coupling agent. As for the metal foil base material 14, a metal foil can be used as in the case of the metal-clad laminate, and among these, a copper foil is preferably used. That is, the resin-coated metal foil according to this embodiment includes, for example, a resin-coated metal foil, preferably a resin-coated copper foil.

Moreover, the method for manufacturing the resin-coated metal foil according to the present embodiment is not particularly limited as long as it is a method capable of manufacturing the resin-coated metal foil. As for the method for producing the resin-coated metal foil, a metal-clad laminate can be obtained in the same manner as a general method for producing a resin-coated metal foil, except that the resin composition is used. Examples thereof include a method of applying the resin composition, for example, a resin composition prepared in the form of varnish onto the metal foil. That is, examples of the resin-coated metal foil according to the embodiment of the present invention include those obtained by applying the resin composition to a metal foil. The coating method is not particularly limited as long as it is a method capable of coating the metal foil with the resin composition. Examples thereof include methods using rolls, die coating, and bar coating, spraying, and the like. Moreover, as a method for producing a resin-coated metal foil, after the application, the metal foil coated with the resin composition may be dried or heated. That is, as a method for producing a resin-coated metal foil, for example, a method in which a resin composition prepared in the form of varnish is applied onto a metal foil and then dried; Examples include a method in which a foil is coated and then heated, and a method in which a resin composition prepared in the form of a varnish is coated on a metal foil, dried, and then heated. In addition, the metal foil coated with the resin composition is heated under desired heating conditions, for example, at 80 to 180 ° C. for 1 to 10 minutes, before curing (A stage) or in a semi-cured state (B stage). A resin-coated metal foil is obtained.

Such a resin-coated metal foil has a low dielectric constant and dielectric properties, a high thermal conductivity, and excellent metal foil adhesion, moisture resistance, and chemical resistance, similar to the metal-clad laminate. is.

[Wiring board]
A wiring board according to another embodiment of the present invention includes an insulating layer and wiring present in contact with at least one surface of the insulating layer. That is, this wiring board has wiring on the surface of the insulating layer. As shown in FIG. 3, the wiring board 31 includes an insulating layer 12 and wirings 17 arranged so as to be in contact with both surfaces thereof. Also, the wiring board may be provided with wiring in contact with only one surface of the insulating layer. 3 is a cross-sectional view showing the configuration of the wiring board 31 according to this embodiment.

The wiring 17 includes a wiring substrate 18 and a surface treatment layer 19 provided at least on the contact surface 20 side of the wiring substrate 18 with the insulating layer 12, as shown in FIG. As the insulating layer 12, the same layer as the insulating layer of the metal-clad laminate can be used. As the wiring 17, for example, a wiring formed by partially removing the metal foil of the metal-clad laminate can be used. Such wiring includes, for example, wiring formed by a method using subtractive, additive, semi-additive, chemical mechanical polishing (CMP), trench, inkjet, squeegee, transfer, or the like. When wiring is formed by partially removing the metal foil of the metal-clad laminate, the wiring base material 18 is obtained by partially removing the metal foil base material of the metal foil.

The wiring board manufacturing method according to the present embodiment is not particularly limited as long as the wiring board can be manufactured using the metal-clad laminate or the resin-coated metal foil. Examples of the method for manufacturing the wiring board include a method using a general metal-clad laminate. Examples of the method of producing a wiring board using a metal-clad laminate include a method of etching the metal foil on the surface of the metal-clad laminate to form a circuit. By this method, a wiring board can be obtained in which a conductor pattern is provided as a circuit on the surface of the metal-clad laminate. That is, the wiring board according to the present embodiment is obtained by partially removing the metal foil on the surface of the metal-clad laminate to form a circuit. The method for producing the wiring board includes a step of obtaining the resin composition, a step of impregnating a fibrous base material with the resin composition to obtain a prepreg, a step of laminating the metal foil on the prepreg, and heating. obtaining a metal-clad laminate comprising an insulating layer containing a cured product of the resin composition and a metal foil present in contact with at least one surface of the insulating layer by pressure molding; forming a wiring existing in contact with at least one surface of the insulating layer by partially removing the metal foil of the laminated laminate.

Such a wiring board has a low dielectric constant and dielectric properties, a high thermal conductivity, and excellent wiring adhesion, moisture resistance, and chemical resistance.

Although this specification discloses various aspects of the technology as described above, the main technologies thereof are summarized below.

A metal-clad laminate according to an aspect of the present invention comprises an insulating layer and a metal foil present in contact with at least one surface of the insulating layer, the insulating layer comprising a styrene-butadiene copolymer, A cured product of a resin composition containing a first silane coupling agent having a carbon-carbon unsaturated double bond in the molecule and silica particles, wherein the metal foil has a contact surface with the insulating layer, It is characterized in that it is surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in its molecule.

With such a configuration, it is possible to provide a metal-clad laminate having a low dielectric constant and dielectric properties, a high thermal conductivity, and excellent metal foil adhesion, moisture resistance, and chemical resistance.

This is believed to be due to the following.

Since the cured product contained in the insulating layer is obtained by curing a resin composition containing a styrene-butadiene copolymer, the dielectric constant and dielectric loss tangent are low. Furthermore, since the resin composition also contains silica particles, it is thought that the thermal conductivity of the cured product of the resin composition can be enhanced. The resin composition contains a first silane coupling agent having a carbon-carbon unsaturated double bond in its molecule. As the metal foil that contacts the insulating layer containing the cured product of the resin composition, a metal foil surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in the molecule is used. The metal foil and the It is thought that the adhesive strength with the insulating layer is increased. From this, it is considered that even if the obtained metal-clad laminate is heated, the metal foil adhesion is high such that the occurrence of peeling of the metal foil is suppressed. Furthermore, it is expected that the metal-clad laminate obtained will have high moisture resistance and chemical resistance, such that the metal foil will be prevented from peeling off, whether it is subjected to moisture absorption treatment or treatment with chemicals such as acids. Conceivable.

Therefore, the obtained metal-clad laminate has low dielectric constant and dielectric properties, high thermal conductivity, and excellent metal foil adhesion, moisture resistance, and chemical resistance.

Further, in the metal-clad laminate, the deterioration rate of the peel strength of the metal foil in the metal-clad laminate after acid treatment with respect to the peel strength of the metal foil in the metal-clad laminate before acid treatment is It is preferably 15% or less.

According to such a configuration, a metal-clad laminate having a low dielectric constant and dielectric properties, a high thermal conductivity, excellent metal foil adhesion and moisture resistance, and excellent chemical resistance can be obtained.

Further, in the metal-clad laminate, the deterioration rate of the peel strength of the metal foil in the metal-clad laminate after the moisture absorption treatment with respect to the peel strength of the metal foil in the metal-clad laminate before the moisture absorption treatment is It is preferably 10% or less.

With such a configuration, a metal-clad laminate having a low dielectric constant and dielectric properties, a high thermal conductivity, excellent metal foil adhesion, excellent chemical resistance, and excellent moisture resistance can be obtained.

Moreover, in the metal-clad laminate, the first silane coupling agent preferably has at least one functional group selected from the group consisting of methacryloxy groups, styryl groups, vinyl groups, and acryloxy groups.

With such a configuration, a metal-clad laminate having a low dielectric constant and dielectric properties, a high thermal conductivity, excellent metal foil adhesion, moisture resistance, and chemical resistance can be obtained. It is considered that this is because the adhesive force between the metal foil and the insulating layer can be further enhanced.

In addition, a resin-coated metal foil according to another aspect of the present invention includes a resin layer and a metal foil present in contact with at least one surface of the resin layer, wherein the resin layer is made of styrene-butadiene copolymer. A polymer, a first silane coupling agent having a carbon-carbon unsaturated double bond in the molecule, and a resin composition containing silica particles or a semi-cured material of the resin composition, wherein the metal foil is A contact surface with the insulating layer is surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in the molecule.

According to such a configuration, the resin-coated metal foil having low dielectric constant and dielectric properties, high thermal conductivity, excellent metal foil adhesiveness, moisture resistance, and chemical resistance, similar to the metal-clad laminate. can provide.

Further, a wiring board according to another aspect of the present invention includes an insulating layer and wiring present in contact with at least one surface of the insulating layer, wherein the insulating layer comprises a styrene-butadiene copolymer and , a first silane coupling agent having a carbon-carbon unsaturated double bond in the molecule, and a cured product of a resin composition containing silica particles, wherein the wiring has a contact surface with the insulating layer, It is characterized in that it is surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in its molecule.

According to such a configuration, it is possible to provide a wiring board having low dielectric constant and dielectric properties, high thermal conductivity, and excellent wiring adhesion, moisture resistance, and chemical resistance, like the metal-clad laminate. can be done.

The present invention will be described in more detail with reference to examples below, but the scope of the present invention is not limited to these.

[Example 1, Example 2, and Comparative Examples 1 to 6]
In this example, each component used in preparing the resin composition will be described.

(styrene-butadiene copolymer)
Styrene-butadiene copolymer 1: A copolymer obtained by copolymerizing styrene and 1,3-butadiene (a styrene-derived unit represented by the above formula (1): a unit represented by the above formula (2) 1,2-linked butadiene-derived units (1,2-adduct): 1,4-linked butadiene-derived units represented by the above formula (3) (1,4-adduct) = 7: 69 : 24 (mass ratio))
Styrene-butadiene copolymer 2: A copolymer obtained by copolymerizing styrene and 1,3-butadiene (a styrene-derived unit represented by the above formula (1): a unit represented by the above formula (2) 1,2-linked butadiene-derived units (1,2-adduct): 1,4-linked butadiene-derived units represented by the above formula (3) (1,4-adduct) = 8: 67 : 25 (mass ratio))
(First silane coupling agent: a silane coupling agent having a carbon-carbon unsaturated double bond in the molecule)
First silane coupling agent: a silane coupling agent having a methacryloxy group in the molecule (3-methacryloxypropyltriethoxysilane, KBE-503 manufactured by Shin-Etsu Chemical Co., Ltd.)
(initiator)
Initiator: α,α'-di(t-butylperoxy)diisopropylbenzene (Perbutyl P manufactured by NOF Corporation)
(silica particles)
Crushed silica: Megasil 525 manufactured by SIBELCO
[Method for preparing resin composition]
Next, a method for preparing the resin composition will be described.

First, each component other than the initiator was added to toluene and mixed at the mixing ratios shown in Tables 1 and 2 below so that the solid content concentration was 60% by mass. The mixture was heated to 80°C and stirred at 80°C for 60 minutes. After that, the stirred mixture was cooled to 40° C., and an initiator was added at the mixing ratio shown in Tables 1 and 2 below to obtain a varnish-like curable composition (varnish). A varnish-like resin composition (varnish) was prepared by stirring the mixture for 60 minutes.

[Method for preparing metal-clad laminate]
Next, a glass cloth was impregnated with the obtained varnish, and then dried by heating at 100 to 170° C. for about 3 to 6 minutes to prepare a prepreg. Specifically, the glass cloth is #1080 type E glass manufactured by Nitto Boseki Co., Ltd. At that time, the content of the resin composition (resin content) was adjusted to about 70% by mass.

Next, two sheets of the produced prepreg are superimposed, and on both sides thereof, the following copper foil is placed as a metal foil to form a pressurized body, and heated and heated for 100 minutes under the conditions of a temperature of 200 ° C. and a pressure of 3 MPa (megapascal). A copper foil-clad laminate (metal-clad laminate) having copper foil adhered to both sides by pressing was produced.

(Metal foil: copper foil surface-treated with aminosilane coupling agent (second silane coupling agent))
Copper foil-1: copper foil ( Aminosilane-treated copper foil, ten-point average roughness Rz: 2.5 μm, thickness: 35 μm)
(Metal foil: Copper foil surface-treated with a silane coupling agent other than the second silane coupling agent)
Copper foil-2: A copper foil ( Aminosilane-treated copper foil, ten-point average roughness Rz: 2.5 μm, thickness: 35 μm)
Copper foil-3: A copper foil (epoxysilane treatment copper foil, ten-point average roughness Rz: 2.5 μm, thickness: 35 μm)
Copper foil-4: A copper foil (methacryloxysilane-treated copper foil, ten-point average roughness Rz: 2.5 μm, thickness: 35 μm)
[evaluation]
Each prepreg and metal-clad laminate (evaluation substrate) prepared as described above were evaluated by the following methods.

[Thermal conductivity]
The thermal conductivity (W/m·K) of the metal-clad laminate was measured by a laser flash method.

[Copper foil adhesion strength]
In the metal-clad laminate, the peeling strength of the copper foil from the insulating layer (copper foil adhesion strength: peeling strength of the metal foil) was measured according to JIS C 6481. A pattern with a width of 10 mm and a length of 100 mm was formed and peeled off at a rate of 50 mm/min using a tensile tester, and the peel strength (copper foil adhesive strength) at that time was measured. The unit of measurement is N/mm.

[Copper foil adhesion strength after acid treatment]
Acid treatment was performed by immersing the metal-clad laminate in 12% hydrochloric acid for 30 minutes. The peeling strength (copper foil adhesive strength) of the copper foil from the insulating layer of the acid-treated metal-clad laminate was measured by the same method as the method for measuring the copper foil adhesive strength. The obtained copper foil adhesive strength was used as the peeling strength of the metal foil in the metal-clad laminate after acid treatment (post-acid treatment peeling strength). The copper foil adhesive strength obtained by the method for measuring the copper foil adhesive strength was used as the peeling strength of the metal foil in the metal-clad laminate before acid treatment (peeling strength before acid treatment). From these peeling strengths, the rate of deterioration of peeling strength due to acid treatment was calculated. The deterioration rate of peel strength due to acid treatment is the deterioration rate of peel strength after acid treatment with respect to peel strength before acid treatment, and was calculated from the following formula.

(Peeling strength before acid treatment−Peeling strength after acid treatment)/Peeling strength before acid treatment×100
[Copper foil adhesion strength after moisture absorption treatment]
Moisture absorption treatment was performed by immersing the metal-clad laminate in water at 100° C. for 2 hours. The peeling strength (copper foil adhesive strength) of the copper foil from the insulating layer of the metal-clad laminate after the moisture absorption treatment was measured by the same method as the method for measuring the copper foil adhesive strength. The obtained copper foil adhesive strength was used as the peeling strength of the metal foil in the metal-clad laminate after the moisture absorption treatment (peeling strength after the moisture absorption treatment). The copper foil adhesive strength obtained by the method for measuring the copper foil adhesive strength was used as the peel strength of the metal foil in the metal-clad laminate before the moisture absorption treatment (peeling strength before moisture absorption treatment). From these peeling strengths, the deterioration rate of the peeling strength due to the moisture absorption treatment was calculated. The deterioration rate of the peeling strength due to the moisture absorption treatment is the deterioration rate of the peeling strength after the moisture absorption treatment to the peel strength before the moisture absorption treatment, and was calculated from the following formula.

(Peeling strength before moisture absorption treatment−Peeling strength after moisture absorption treatment)/Peeling strength before moisture absorption treatment×100
[Dielectric properties (relative permittivity and dielectric loss tangent)]
The dielectric constant and dielectric loss tangent of the evaluation substrate at 1 GHz were measured by a method according to IPC-TM650-2.5.5.9. Specifically, using an impedance analyzer (RF impedance analyzer HP4291B manufactured by Agilent Technologies), the dielectric constant and dielectric loss tangent of the evaluation substrate at 1 GHz were measured.

Tables 1 and 2 show the results of each of the above evaluations.

As can be seen from Tables 1 and 2, as an insulating layer, a resin containing a styrene-butadiene copolymer, a first silane coupling agent having a carbon-carbon unsaturated double bond in the molecule, and silica particles. An insulating layer containing a cured product of the composition is used, and the metal foil is a metal whose contact surface with the insulating layer is surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in the molecule. When a foil was used (Examples 1 and 2), when a metal foil surface-treated with a silane coupling agent other than the second silane coupling agent was used as the metal foil (Comparative Examples 1 to 6). Compared to the acid treatment, the deterioration rate of the peeling strength of the metal foil in the metal-clad laminate after the acid treatment and the deterioration rate of the peeling strength of the metal foil in the metal-clad laminate after the moisture absorption treatment were low. . Moreover, the metal-clad laminates according to Examples 1 and 2 had low dielectric constants and dielectric properties, high thermal conductivity, and excellent metal foil adhesiveness. From these, the metal-clad laminates according to Examples 1 and 2 have low dielectric constant and dielectric properties, high thermal conductivity, excellent metal foil adhesion, moisture resistance, and chemical resistance. It was a laminated board.

REFERENCE SIGNS LIST 11 metal-clad laminate 12 insulating layer 13 metal foil 14 metal foil substrate 15, 19 surface treatment layer 17 wiring 18 wiring substrate 21 metal foil with resin 22 resin layer 31 wiring board

Claims (6)

An insulating layer and a metal foil present in contact with at least one surface of the insulating layer,
The insulating layer comprises a cured product of a resin composition containing a styrene-butadiene copolymer, a first silane coupling agent having a carbon-carbon unsaturated double bond in the molecule, and silica particles,
A metal-clad laminate, wherein the metal foil has a contact surface with the insulating layer that is surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in the molecule. The metal-clad laminate is immersed in 12% hydrochloric acid for 30 minutes With respect to the peel strength of the metal foil in the metal-clad laminate before acid treatment,Said2. The metal-clad laminate according to claim 1, wherein the deterioration rate of the peeling strength of the metal foil in the metal-clad laminate after acid treatment is 15% or less. The metal-clad laminate is immersed in water at 100°C for 2 hours. For the peel strength of the metal foil in the metal-clad laminate before moisture absorption treatment,Said3. The metal-clad laminate according to claim 1, wherein the deterioration rate of peeling strength of the metal foil in the metal-clad laminate after moisture absorption treatment is 10% or less. The metal tension according to any one of claims 1 to 3, wherein the first silane coupling agent has at least one functional group selected from the group consisting of a methacryloxy group, a styryl group, a vinyl group, and an acryloxy group. laminated board. comprising a resin layer and a metal foil present in contact with at least one surface of the resin layer;
The resin layer comprises a resin composition or a half of the resin composition containing a styrene-butadiene copolymer, a first silane coupling agent having a carbon-carbon unsaturated double bond in the molecule, and silica particles. Including hardened material,
A resin-coated metal foil, wherein a contact surface of the metal foil with the insulating layer is surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in the molecule. An insulating layer and a wiring present in contact with at least one surface of the insulating layer,
The insulating layer comprises a cured product of a resin composition containing a styrene-butadiene copolymer, a first silane coupling agent having a carbon-carbon unsaturated double bond in the molecule, and silica particles,
A wiring board, wherein the wiring is surface-treated with a second silane coupling agent having an amino group composed of an aliphatic amine in the molecule at a contact surface of the wiring with the insulating layer.

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