JP7069561B2 - Manufacturing method of laminated board, manufacturing method of printed wiring board, manufacturing method of semiconductor package - Google Patents

Description

The present invention relates to a method for manufacturing a laminated board, a method for manufacturing a printed wiring board, and a method for manufacturing a semiconductor package.

In recent years, from the viewpoint of protecting the global environment, solder has become lead-free, and the temperature of the reflow process at the time of mounting components on a printed wiring board and at the time of assembling a semiconductor package has become extremely high. Along with this, there is an increasing demand for reliability improvement of laminated boards for printed wiring boards by improving heat resistance and the like.
By the way, as a laminated board for a printed wiring board, a prepreg containing a resin composition containing an epoxy resin as a main component and a glass cloth is generally cured and integrally molded. Epoxy resin has an excellent balance of insulation, heat resistance, moldability, cost, etc., but it is further necessary to meet the demand for improved heat resistance due to the recent high-density mounting of printed wiring boards and high-multilayer configurations. Improvement is required, and as a material having excellent heat resistance, polybismaleimide resin is widely used as a material for laminated boards for printed wiring boards.

In addition, with the recent trend toward miniaturization and higher performance of electronic devices, the wiring density and high integration of printed wiring boards are increasing. Therefore, especially in semiconductor package substrate applications, warpage due to the difference in the coefficient of thermal expansion between the chip and the substrate during component mounting and package assembly has become a major issue. Therefore, a laminated board for a semiconductor package substrate is required to have good low thermal expansion.
As mentioned above, laminated boards for semiconductor package substrates are required to have good low thermal expansion, but epoxy resins and polybismaleimide resins do not have sufficient low thermal expansion, so inorganic fillers such as silica are used. By filling, the thermal expansion is reduced (see, for example, Patent Document 1). However, high filling of the inorganic filler not only makes it easier for insulation reliability to decrease due to moisture absorption and insufficient adhesion between the resin and the wiring layer, but also leads to an increase in the melt viscosity of the resin composition, resulting in an increase in the melt viscosity. , It is known that the circuit embedding property tends to decrease. That is, there is a limit to the low thermal expansion only by the high filling of the inorganic filler.
On the other hand, as a resin having excellent low thermal expansion property, a resin composition containing a modified imide resin obtained by modifying a polybismaleimide resin with a siloxane compound has been studied (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 05-148343 Japanese Unexamined Patent Publication No. 2014-129521

However, although the modified polyimide resin described in Patent Document 2 is excellent in heat resistance, high elastic modulus, and low coefficient of thermal expansion, the melt viscosity of the resin composition increases as in the case of the above-mentioned high filling of the inorganic filler. After all, it has been found that the circuit embedding property tends to decrease. In addition, in recent printed wiring boards, the insulating layer has become thinner due to the advancement of higher wiring density and higher integration, so it is necessary to embed the circuit with a smaller amount of resin than before, further improving moldability. Is desired.
Therefore, the problem of the present invention is that even if the thermosetting resin composition contained in the prepreg has a high melt viscosity and a low circuit embedding property of the prepreg, there is no problem in embedding the circuit and high moldability can be exhibited. It is an object of the present invention to provide a method for manufacturing a plate, a method for manufacturing a printed wiring board, and a method for manufacturing a semiconductor package.

As a result of diligent research to solve the above problems, the present inventors have provided a step of laminating a resin film on a circuit board, so that the melt viscosity of the thermosetting resin composition contained in the prepreg is high. Even if the circuit embedding property of the prepreg itself is low, the obtained laminated board has no problem in embedding the circuit and has high formability, and has completed the present invention.

That is, the present invention provides the following [1] to [11].
[1] A method for manufacturing a laminated board, which comprises the following steps (i) to (iii) in this order.
(I) A step of laminating a resin film with a support having a minimum melt viscosity of the resin film of 800 to 3,500 MPa · s on a circuit board.
(Ii) A step of removing the support of the resin film with the support laminated on the circuit board.
(Iii) A step of laminating a prepreg on a resin film from which a support has been removed.
[2] The method for producing a laminated board according to the above [1], wherein the resin film contains a thermoplastic elastomer (a).
[3] The above [1] or the above-mentioned [1] or the above-mentioned resin film contains a maleimide compound (b) having at least two N-substituted maleimide groups and an amine compound (c) having at least two primary amino groups. The method for manufacturing a laminated board according to [2].
[4] The resin film is a polyimide compound which is a reaction product of a maleimide compound (b) having at least two N-substituted maleimide groups and an amine compound (c) having at least two primary amino groups. The method for producing a laminated board according to any one of the above [1] to [3], which contains (x).
[5] The method for producing a laminated board according to any one of [1] to [4] above, wherein the resin film contains a thermosetting resin (d).
[6] The method for producing a laminated board according to any one of [3] to [5] above, wherein the resin film contains a curing accelerator (e).
[7] The method for producing a laminated board according to any one of the above [1] to [6], wherein the resin film contains an inorganic filler (f).
[8] The laminated board according to any one of [1] to [7] above, wherein the minimum melt viscosity of the resin film is smaller than the minimum melt viscosity of the semi-cured product of the thermosetting resin composition constituting the prepreg. Manufacturing method.
[9] The method for manufacturing a laminated board according to any one of the above [1] to [8], wherein the prepreg has a thickness of 10 to 70 μm.
[10] A method for manufacturing a printed wiring board, comprising a step of forming a circuit pattern on a laminated board obtained by the manufacturing method according to any one of [1] to [9] above.
[11] A method for manufacturing a semiconductor package, comprising a step of mounting a semiconductor element on a printed wiring board obtained by the manufacturing method according to the above [10].

According to the present invention, even if the thermosetting resin composition contained in the prepreg has a high melt viscosity and the circuit embedding property of the prepreg itself is low, there is no problem in embedding the circuit and a laminated board capable of exhibiting high formability. A method for manufacturing a printed wiring board, a method for manufacturing a semiconductor package, and a method for manufacturing a semiconductor package can be provided.

It is a schematic diagram for demonstrating the step (i) in the manufacturing method of the laminated board of this invention. It is a schematic diagram for demonstrating the process (ii) in the manufacturing method of the laminated board of this invention. It is a schematic diagram for demonstrating the step (iii) in the manufacturing method of the laminated board of this invention.

[Manufacturing method of printed wiring board]
The present invention is a method for manufacturing a laminated board, which comprises the following steps (i) to (iii) in this order.
(I) A step of laminating a resin film with a support having a minimum melt viscosity of the resin film of 800 to 3,500 Pa · s on a circuit board.
(Ii) A step of removing the support of the resin film with the support laminated on the circuit board.
(Iii) A step of laminating a prepreg on a resin film from which a support has been removed.
The method for producing a laminated board of the present invention is not limited to the above steps (i) to (iii).
Hereinafter, each step of the method for manufacturing a laminated board of the present invention will be briefly described with reference to FIGS. 1 to 3, and then the materials and the like used in each step will be described. The symbols given to the substance names correspond to the symbols shown in the drawings.

[Step (i)]
The step (i) is a step of laminating the resin film (4) with a support having a minimum melt viscosity of the resin film of 800 to 3,500 Pa · s on the circuit board (1) [hereinafter, the laminating step (i). It may also be called. ].
More specifically, the surface on which the circuit of the circuit board (1) is formed by heating and pressurizing the "resin film (4) with a support" in which the resin film (2) is formed on the support (3). It is a process of embedding a circuit by laminating it on.

In the laminating step (1), the circuit board (1) can be suitably laminated using a vacuum laminator. A commercially available device can be used as the vacuum laminator. Examples of commercially available vacuum laminators include a vacuum applicator manufactured by Nichigo Morton Co., Ltd., a vacuum pressurized laminator manufactured by Meiki Seisakusho Co., Ltd., a roll-type dry coater manufactured by Hitachi Industries Co., Ltd., and a roll-type dry coater manufactured by Hitachi AIC Co., Ltd. Examples include a vacuum laminator.
Lamination is performed by pressing the resin surface of the resin film (4) with a support against the circuit board (1) while applying pressure and heating. The laminate is not particularly limited, but the resin film (4) with a support and the circuit board (1) are preheated (preheated) as necessary, and then the crimping temperature (laminate temperature) is 60 to 140 ° C. The crimping pressure is preferably 0.1 to 1.1 MPa, and the air pressure is preferably 20 mmHg (26.7 hPa) or less under reduced pressure.
The crimping temperature (lamination temperature) is more preferably 80 to 160 ° C, still more preferably 80 to 140 ° C, particularly preferably 100 to 140 ° C, and most preferably 120 to 140 ° C.
The crimping pressure is more preferably 0.2 to 0.8 MPa, still more preferably 0.3 to 0.7 MPa.
The vacuum pressurization time in the laminate is not particularly limited, but is preferably 20 to 90 seconds, more preferably 30 to 80 seconds, and even more preferably 40 to 80 seconds.

[Process (ii)]
The step (ii) is a step of removing the support (3) of the resin film (4) with the support laminated on the circuit board (1).
The method for removing the support (3) from the resin film (4) with the support is not particularly limited, and the support (3) can be easily removed by peeling by a known peeling means. The removal of the support (3) is preferably carried out at room temperature.

[Step (iii)]
The step (iii) is a step of laminating the prepreg (5) on the resin film from which the support (3) has been removed, that is, the resin film (2).
The method of laminating the prepreg (5) is not particularly limited, and a known method used in the manufacture of a laminated board for an electric insulating material and a multi-layer board can be used. For example, using a multi-stage press, multi-stage vacuum press, continuous molding, autoclave molding machine, etc., the temperature is 100 to 250 ° C (preferably 180 to 250 ° C), the pressure is 0.2 to 10 MPa (preferably 1.5 to 5 MPa), and the pressure is 0.2 to 10 MPa. Laminate molding can be performed under the condition of heating time of 0.1 to 5 hours (preferably 0.5 to 2 hours).
The thickness of the prepreg (5) may be 10 to 300 μm, but in the present invention, even if a prepreg (5) having a thickness of about 10 to 100 μm or even 10 to 70 μm is used, the circuit is embedded. It is advantageous in that there is no problem with sex. The thickness of the prepreg (5) may be 10 to 50 μm, 10 to 40 μm, or 10 to 30 μm.
By installing a metal foil on the outer side of the prepreg (5), a metal-clad laminate can be obtained.

Next, the materials used in each step will be described in detail.
(Circuit board (1))
In the present invention, the circuit board refers to a sheet-like circuit board having a circuit forming surface processed on one side or both sides of the board. As the substrate, a known substrate that can be used as a substrate for a printed wiring board can be used, for example, a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin (bismaleimide triazine resin) substrate, and heat curing. Examples thereof include a type polyphenylene ether substrate.
The circuit board also includes a build-up layer and an inner layer circuit board which is an intermediate product on which the circuit should be formed.

The method for manufacturing the circuit board is not particularly limited. For example, a core layer having metal foils on both sides is used, a predetermined portion is opened with a drill machine, and electroless plating is performed to conduct conduction on both sides of the core layer. Then, it can be manufactured by forming a circuit by etching a metal foil. As the inner layer circuit portion, one that has been subjected to a roughening treatment such as a blackening treatment can be preferably used. Further, the opening can be appropriately filled with a conductor paste or a resin paste.

(Resin film with support (4))
The resin film (4) with a support is heat-cured (including semi-curing) by mixing the components for the resin film (2) described later and then applying the resin film (4) to the support (3) to remove unnecessary organic solvents. ) To make a film. The thermosetting here cures (semi-cures) the components for the resin film (2) so as to have a viscosity that facilitates laminating work. Specifically, the resin obtained by curing is cured. As long as the minimum melt viscosity of the film (2) is within the range of 800 to 3,500 Pa · s as described later, the curing conditions are not particularly limited, but for example, 90 to 300 at 70 to 140 ° C. The condition of heating for 1 second is preferable, and the condition of heating at 90 to 120 ° C. for 120 to 240 seconds is more preferable.

Examples of the support include a carrier film. Examples of the carrier film include organic films such as polyethylene terephthalate (PET), biaxially stretched polypropylene (OPP), polyethylene, polyvinylfluorate, and polyimide; copper, aluminum, and alloy films of these metals; these organic films or metals. Examples thereof include a film in which the surface of the film is subjected to a mold release treatment with a mold release agent. PET film is preferable from the viewpoint of workability and heat resistance, and the point that it is easy to release.

The minimum melt viscosity of the resin film (2) in the resin film (4) with a support is 800 to 3,500 Pa · s. By setting the minimum melt viscosity of the resin film (2) to 3,500 P a · s or less, circuit embedding can be performed satisfactorily, and by setting it to 800 P a · s or more, in a thin laminated plate. , Thickness accuracy can be improved. Here, in the present invention, the minimum melt viscosity is a value measured by the method described in Examples. From the same viewpoint, the minimum melt viscosity of the resin film (2) is preferably 500 to 3,000 P a · s, more preferably 500 to 2,500 P a · s, still more preferably 1,000 to 2 , 500P a · s, and in another embodiment, it may be 1,000 to 3,000P a · s or 1,500 to 3,000P a · s. However, it may be 1,500 to 2,500 P a · s.

Further, the minimum melt viscosity of the resin film (2) is preferably smaller than the minimum melt viscosity of the semi-cured product of the thermosetting resin composition constituting the prepreg (5) described later, which is 20 Pa · s or more. Smaller is more preferable, it is more preferably 40P a · s or more smaller, 100P a · s or more smaller than 100P a · s or more, particularly preferably 160P a · s or more smaller, and 250P a · s or more smaller. Is most preferable.
When the component for the resin film (2) is the same as the component of the thermosetting resin composition constituting the prepreg (5), the semi-curing performed when producing the prepreg (5) By weakening the degree of curing, the minimum melt viscosity of the resin film (2) can be made smaller than the minimum melt viscosity of the semi-cured product of the thermosetting resin composition constituting the prepreg (5). Specifically, by adopting conditions such as (i) a lower drying temperature and (ii) a shorter drying time than the semi-curing conditions for producing the prepreg (5) described later, even if the prepreg (i) is used. Even if the components and contents of the semi-cured product of the thermosetting resin composition constituting 5) are the same, the minimum melting of the semi-cured product of the thermosetting resin composition constituting prepreg (5) A resin film (2) having a minimum melt viscosity lower than the viscosity can be obtained. On the other hand, (iii) the content of the curing accelerator in the component for the resin film (2) is reduced, (iv) the content of the inorganic filler in the component for the resin film (2) is reduced, and the like. Depending on the method, there is also a method of lowering the minimum melt viscosity of the semi-cured product of the thermosetting resin composition constituting the prepreg (5) described later, and in this case, the thermosetting for producing the resin film (2). The conditions may be the same as the semi-curing conditions carried out when the prepreg (5) is prepared.

The thickness of the resin layer in the resin film (2) may be appropriately adjusted according to the thickness of the inner layer circuit and the like, but is preferably 10 to 100 μm. When the thickness is 10 μm or more, circuit embedding can be performed satisfactorily, and when the thickness is 100 μm or less, it is effective for thinning the laminated board. From the same viewpoint, the thickness of the resin layer in the resin film (2) is more preferably 10 to 50 μm, further preferably 10 to 30 μm.

[Thermoplastic elastomer (a)]
The above resin film (2) can contain a thermoplastic elastomer (a). The thermoplastic elastomer (a) has a hard segment and a soft segment, and in general, the hard segment contributes to heat resistance and strength, and the soft segment contributes to flexibility and toughness.
Examples of the thermoplastic elastomer (a) include styrene-based thermoplastic elastomers, acrylic-based thermoplastic elastomers, olefin-based thermoplastic elastomers, urethane-based thermoplastic elastomers, polyester-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and silicone-based thermals. Examples thereof include a plastic elastomer and a derivative thereof. These consist of a hard segment component and a soft segment component, and the former generally contributes to heat resistance and strength, and the latter contributes to flexibility and toughness.
Among these, from the viewpoint of heat resistance and insulation reliability, styrene-based thermoplastic elastomers, olefin-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and silicone-based thermoplastic elastomers are preferable, and styrene-based thermoplastic elastomers and copper foils are used. Acrylic thermoplastic elastomers are more preferable from the viewpoint of reducing the elasticity of the resin composition while maintaining good adhesiveness. Considering the balance between heat resistance, insulation reliability, and reducing the elastic modulus of the resin composition while maintaining good adhesion to the copper foil, the combined use of styrene-based thermoplastic elastomer and acrylic-based thermoplastic elastomer is also possible. preferable. When the styrene-based thermoplastic elastomer and the acrylic-based thermoplastic elastomer are used in combination, the content ratio thereof (styrene-based thermoplastic elastomer / acrylic-based thermoplastic elastomer) is not particularly limited, but is preferably 20/80 in terms of mass ratio. It is -80/20, more preferably 30/70 to 70/30, and even more preferably 40/60 to 60/40.
As the thermoplastic elastomer (a), one type may be used alone, or two or more types may be used in combination.

The thermoplastic elastomer (a) may have a reactive functional group at at least one of the molecular terminal and the molecular chain. Examples of the reactive functional group include an epoxy group, a hydroxyl group, a carboxy group, an amino group, an amide group, an isocyanato group, an acrylic group, a (meth) acrylic group, a vinyl group and the like. By having a reactive functional group, compatibility with other resin components is improved, internal stress generated during curing of the resin composition can be reduced more effectively, and as a result, the warpage of the substrate is remarkable. Can be reduced to. In particular, from the viewpoint of low thermal expansion and adhesive strength with a metal circuit, it is preferable to have at least one selected from the group consisting of an epoxy group, a hydroxyl group, a carboxy group, an amino group and an amide group, and it is preferable to have heat resistance and insulation reliability. From the viewpoint of sex, it is more preferable to have one or more selected from the group consisting of an epoxy group and a carboxy group.

<Styrene-based thermoplastic elastomer>
Examples of the styrene-based thermoplastic elastomer include a styrene-butadiene copolymer such as a styrene-butadiene-styrene block copolymer; a styrene-isoprene copolymer such as a styrene-isoprene-styrene block copolymer; and a styrene-ethylene-butylene-styrene block copolymer. , Styrene-ethylene-propylene-styrene block copolymer and the like. As the raw material monomer of the styrene-based elastomer, in addition to styrene, styrene derivatives such as α-methylstyrene, 3-methylstyrene, 4-propylstyrene and 4-cyclohexylstyrene can be used. Among these, a styrene-butadiene copolymer and a styrene-isoprene copolymer are preferable, and a hydrogenated styrene-butadiene copolymer resin and a hydrogenated styrene-isoprene copolymer obtained by hydrogenating the double-bonded portion of these copolymers are preferable. Resins and the like are more preferable, and hydrogenated styrene-butadiene copolymer resins are even more preferable.
The weight average molecular weight (Mw) of the styrene-based thermoplastic elastomer is not particularly limited, but is preferably 100 to 1,000,000, more preferably 200 to 800,000, more preferably 200 to 600,000, still more preferably. It is 500 to 50,000, particularly preferably 1,000 to 25,000, and most preferably 1,000 to 10,000. The weight average molecular weight (Mw) was measured by gel permeation chromatography (GPC) and converted by a calibration curve prepared using standard polystyrene, and the same applies hereinafter.
The styrene-based thermoplastic elastomer preferably has the reactive functional group, particularly a carboxy group, at least one of the molecular terminal and the molecular chain.
As the styrene-based elastomer, a commercially available product may be used. Commercially available products include "Toughpren (registered trademark)", "Asaplen (registered trademark) T", "Toughtech (registered trademark) H1043", "Toughtech (registered trademark) MP10", "Toughtech (registered trademark) M1911", and "Toughtech (registered trademark) M1911". Tough Tech (registered trademark) M1913 "(above, Asahi Kasei Chemicals Co., Ltd.)," Epofriend (registered trademark) AT501 "," Epofriend (registered trademark) CT310 "(above, manufactured by Daicel Co., Ltd.)," Septon (registered trademark) ) 2063 ”(manufactured by Kurare Co., Ltd.) and the like.

<Acrylic Thermoplastic Elastomer>
The acrylic thermoplastic elastomer is a polymer formed of molecules containing at least a structural unit derived from an acrylic acid ester. The acrylic thermoplastic elastomer contains a structural unit derived from a plurality of different types of acrylic acid esters in the molecule, and may further contain a structural unit derived from a monomer other than the acrylic acid ester. Further, the acrylic thermoplastic elastomer may be composed of structural units derived from a plurality of types of acrylic acid esters.

Specific examples of the acrylic acid ester include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl acrylate, butyl acrylate, isobutyl acrylate, t-butyl acrylate, pentyl acrylate, hexyl acrylate, and acrylic. Examples thereof include cyclohexyl acid, octyl acrylate, decyl acrylate, lauryl acrylate, and benzyl acrylate.
Examples of the monomer other than the acrylic acid ester include vinyl-based monomers other than the acrylic acid ester such as acrylonitrile, acrylamide, acrylic acid, methacrylic acid, methacrylic acid ester, styrene, ethylene, propylene and butadiene. .. The monomer other than the acrylic acid ester may be one kind or two or more kinds.

The acrylic thermoplastic elastomer preferably has the reactive functional group at the molecular end or at least one of the molecular chain in the molecular chain. In particular, from the viewpoint of adhesion to the metal foil, the reactive functional group that the acrylic thermoplastic elastomer may have is preferably an epoxy group, a hydroxyl group, a carboxyl group, an amino group or an amide group, and has heat resistance and insulation. From the viewpoint of reliability, an epoxy group, a hydroxyl group and an amino group are more preferable, and an epoxy group is further preferable.

The weight average molecular weight (Mw) of the acrylic thermoplastic elastomer is not particularly limited, but is preferably 10,000 to 2,000,000, more preferably 50,000 to 1,200,000, and 100,000 to 900, 000 is more preferable, and 500,000 to 900,000 is particularly preferable. When the weight average molecular weight (Mw) is 10,000 or more, the low elastic modulus tends to be easily maintained, and when the weight average molecular weight (Mw) is 2,000,000 or less, the compatibility and fluidity tend to be good.

When the resin film (2) contains the thermoplastic elastomer (a), the content thereof is not particularly limited, but from the viewpoint of good compatibility and low elasticity of the cured product, the resin film (2) It is preferably 1 to 60 parts by mass, more preferably 10 to 50 parts by mass, and further preferably 10 to 40 parts by mass with respect to 100 parts by mass of the total solid content of the resin component in the resin composition forming the above.

[Maleimide compound having at least two N-substituted maleimide groups (b), amine compound having at least two primary amino groups (c)]
The resin film (2) is a maleimide compound (b) having at least two N-substituted maleimide groups [hereinafter, may be abbreviated as a maleimide compound (b). ], Amine compound (c) having at least two primary amino groups [hereinafter, may be abbreviated as amine compound (c). ] May be contained.
The maleimide compound (b) and the amine compound (c) may be used alone or in combination of two or more.

The maleimide compound (b) is a maleimide compound having an aliphatic hydrocarbon group between any two maleimide groups among a plurality of maleimide groups, or any of a plurality of maleimide groups. Examples thereof include a maleimide compound containing an aromatic hydrocarbon group between two maleimide groups [hereinafter, referred to as an aromatic hydrocarbon group-containing maleimide]. Among these, maleimide containing an aromatic hydrocarbon group is preferable from the viewpoints of heat resistance, dielectric properties, glass transition temperature, coefficient of thermal expansion and moldability. The aromatic hydrocarbon group-containing maleimide may contain an aromatic hydrocarbon group between any of two arbitrarily selected combinations of maleimide groups.

（式中、Ｒ^１及びＲ^２は、各々独立に、炭素数１～５の脂肪族炭化水素基又はハロゲン原子を示す。Ｘ^１は、炭素数１～５のアルキレン基、炭素数２～５のアルキリデン基、－Ｏ－、－Ｃ（＝Ｏ）－、－Ｓ－、－Ｓ－Ｓ－又はスルホニル基を示す。ｍ及びｎは、各々独立に、０～４の整数である。） The maleimide compound (b) is preferably an aromatic hydrocarbon group-containing maleimide represented by the following general formula (I).

(In the formula, R ¹ and R ² each independently represent an aliphatic hydrocarbon group or a halogen atom having 1 to 5 carbon atoms. X ¹ is an alkylene group having 1 to 5 carbon atoms and 2 to 5 carbon atoms. Indicates an alkylidene group, -O-, -C (= O)-, -S-, -SS- or a sulfonyl group. M and n are independently integers of 0 to 4).

Examples of the aliphatic hydrocarbon group having 1 to 5 carbon atoms represented by R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group and an n-. Examples include pentyl groups. The aliphatic hydrocarbon group is preferably an aliphatic hydrocarbon group having 1 to 3 carbon atoms, and more preferably a methyl group, from the viewpoints of heat resistance, dielectric properties, glass transition temperature, coefficient of thermal expansion and moldability. , Ethyl group.
Examples of the halogen atom indicated by R ¹ and R ² include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.
Examples of the alkylene group having 1 to 5 carbon atoms indicated by X ¹ include a methylene group, a 1,2-dimethylene group, a 1,3-trimethylethylene group, a 1,4-tetramethylene group, a 1,5-pentamethylene group and the like. Be done. The alkylene group is preferably an alkylene group having 1 to 3 carbon atoms, and more preferably a methylene group, from the viewpoints of heat resistance, dielectric properties, glass transition temperature, coefficient of thermal expansion and moldability.
Examples of the alkylidene group having 2 to 5 carbon atoms indicated by X ¹ include an ethylidene group, a propyridene group, an isopropylidene group, a butylidene group, an isobutylidene group, a pentylidene group and an isopentylidene group. Among these, an isopropylidene group is preferable from the viewpoints of heat resistance, dielectric properties, glass transition temperature, coefficient of thermal expansion and moldability.
Among the above options, X ¹ is preferably an alkylene group having 1 to 5 carbon atoms, an alkylidene group having 2 to 5 carbon atoms, and more preferably an alkylene group having 1 to 5 carbon atoms. More preferable ones are as described above.

Specific examples of the maleimide compound (b) include bis (4-maleimidephenyl) methane, polyphenylmethane maleimide, bis (4-maleimidephenyl) ether, and bis (4-maleimidephenyl) sulfone, 3,3-. Dimethyl-5,5-diethyl-4,4-diphenylmethanebismaleimide, 4-methyl-1,3-phenylenebismaleimide, m-phenylenebismaleimide, 2,2-bis (4- (4-maleimidephenoxy) phenyl) Examples include propane.
Among these, bis (4-maleimidephenyl) methane, bis (4-maleimidephenyl) sulfone, 3,3-dimethyl-5,5-diethyl- 4,4-Diphenylmethanebismaleimide, 2,2-bis (4- (4-maleimidephenoxy) phenyl) propane is preferred, 2,2-bis (4- (4-maleimidephenoxy) phenyl) propane is more preferred, and the solvent. From the viewpoint of solubility in, 3,3-dimethyl-5,5-diethyl-4,4-diphenylmethanebismaleimide and bis (4-maleimidephenyl) methane are more preferable, and from the viewpoint of low cost, bis ( 4-Maleimidephenyl) methane is particularly preferred.

When the resin film (2) contains the maleimide compound (b), the content thereof is not particularly limited, but it has low warpage, dimensional stability, low thermal expansion, low elasticity, heat resistance, and adhesion to metal circuits. From the viewpoint of the above, preferably 30 to 95 parts by mass, more preferably 40 to 90 parts by mass, still more preferably, with respect to 100 parts by mass of the total solid content of the resin component in the resin composition forming the resin film (2). Is 45 to 85 parts by mass, particularly preferably 50 to 85 parts by mass.

（式中、Ｘ^２は、単結合、炭素数１～５のアルキレン基、炭素数２～５のアルキリデン基、－Ｏ－、スルホニル基、－Ｃ（＝Ｏ）－、フルオレニレン基又はフェニレンジオキシ基である。Ｒ^３及びＲ^４は、各々独立に、炭素数１～５のアルキル基、炭素数１～５のアルコキシ基、ハロゲン原子、水酸基、カルボキシ基又はスルホン酸基を示す。ｖ及びｗは、各々独立に、０～４の整数である。） As the amine compound (c), a diamine compound represented by the following general formula (II) is preferable.

(In the formula, X ² is a single bond, an alkylene group having 1 to 5 carbon atoms, an alkylidene group having 2 to 5 carbon atoms, -O-, a sulfonyl group, -C (= O)-, a fluorenylene group or a phenylenedioxy. The groups R ³ and R ⁴ independently represent an alkyl group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a halogen atom, a hydroxyl group, a carboxy group or a sulfonic acid group, respectively. Are independently integers from 0 to 4).

Examples of the alkylene group having 1 to 5 carbon atoms indicated by X ² include a methylene group, an ethylene group, a propylene group, a propylene group and the like. As the alkylene group, an alkylene group having 1 to 3 carbon atoms is preferable, and a methylene group is more preferable.
Examples of the alkylidene group having 2 to 5 carbon atoms indicated by X ² include an ethylidene group, a propyridene group, an isopropylidene group, a butylidene group, an isobutylidene group, a pentylidene group and an isopentylidene group. As the alkylidene group, an isopropylidene group is preferable.
As X ² , a single bond, an alkylene group having 1 to 5 carbon atoms, and —O— are preferable, and a single bond is more preferable.
Examples of the alkyl group having 1 to 5 carbon atoms indicated by R ³ and R ⁴ include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a t-butyl group, an n-pentyl group and the like. Can be mentioned. The alkyl group is preferably an alkyl group having 1 to 3 carbon atoms, and more preferably a methyl group.
Examples of the alkoxy group having 1 to 5 carbon atoms indicated by R ³ and R ⁴ include a methoxy group, an ethoxy group, a propoxy group and the like. The alkoxy group is preferably a methoxy group.
Examples of the halogen atom indicated by R ³ and R ⁴ include a fluorine atom, a chlorine atom, a bromine atom, an iodine atom and the like.
v and w are each independently, preferably an integer of 0 to 2, more preferably 0 or 1, and even more preferably 1.

Examples of the amine compound (c) include diaminobenzidine, diaminodiphenylmethane, diaminodiphenyl ether, diaminodiphenylsulfone, 3,3'-dichloro-4,4'-diaminobiphenyl, 3,3'-dimethoxy-4,4'-. Diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl, 3,3'-dichloro-4,4'-diaminobiphenyl, 3,3'-dimethyl-4,4'-diaminobiphenyl-6, 6'-disulfonic acid, 2,2', 5,5'-tetrachloro-4,4'-diaminobiphenyl, 4,4'-methylene-bis (2-chloroaniline), 1,3'-bis (4) -Aminophenoxy) benzene, 2,2'-bis [4- (4-aminophenoxy) phenyl] propane, bis [4- (4-aminophenoxy) phenyl] sulfone, bis [4- (3-aminophenoxy) phenyl ] Sulphonate, 4,4'-bis (4-aminophenoxy) biphenyl, 2,2'-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane, 1,4'-bis (4-aminophenoxy) Benzene, 4,4'-diaminodiphenyl sulfide, 2,2'-dimethyl-4,4'-diaminobiphenyl, 4,4'-diamino-3,3'-biphenyldiol, 9,9'-bis (4-) Aminophenyl) fluorene, o-tridin sulfone and the like can be mentioned.

As the amine compound (c), a commercially available product can be used. Commercially available products include, for example, "PAM-E" (functional group equivalent 130), "KF-8010" (functional group equivalent 430), and "X-22-161A" (functional group equivalent 800) having amino groups at both ends. ), "X-22-161B" (functional group equivalent 1,500), "KF-8012" (functional group equivalent 2,200), "KF-8008" (functional group equivalent 5,700) [above, Shin-Etsu Chemical Industrial Co., Ltd.], "BY16-871" (functional group equivalent 130), "BY16-853U" (functional group equivalent 460) [above, manufactured by Toray Dow Corning Co., Ltd.] and the like.

When the resin film (2) contains the amine compound (c), the content thereof is not particularly limited, but it has low warpage, dimensional stability, low thermal expansion, low elasticity, heat resistance and adhesion to metal circuits. From the viewpoint of the above, preferably 1 to 40 parts by mass, more preferably 1 to 35 parts by mass, still more preferably, with respect to 100 parts by mass of the total solid content of the resin component in the resin composition forming the resin film (2). Is 3 to 30 parts by mass.

In the present invention, the resin film (2) may contain a polyimide compound (x) which is a reaction product of the maleimide compound (b) and the amine compound (c). When the resin film (2) contains the polyimide compound (x), the resin film (2) may not contain the maleimide compound (b) or the amine compound (c), or the maleimide compound. It may contain at least one selected from the group consisting of (b) and the amine compound (c). The preferable content of the polyimide compound (x) may be converted into the preferable contents of the maleimide compound (b) and the amine compound (c), which are the raw materials of the polyimide compound (x).
When at least one selected from the group consisting of the maleimide compound (b) and the amine compound (c) is used in combination with the polyimide compound (x), the content of each of the maleimide compound (b) and the amine compound (c) It is preferable that the total amount of the maleimide compound (b) and the amine compound (c) used as raw materials for producing the polyimide compound (x) is within the above preferable range. For example, when the amine compound (c) and the polyimide compound (x) are used in combination, the content of the amine compound (c) itself and the amount of the amine compound (c) used for producing the polyimide compound (x) are the same. The total amount is preferably within the range of the preferable content of the amine compound (c).

The polyimide compound (x) is obtained by heating and reacting the maleimide compound (b) with the amine compound (c). The polyimide compound (x) may be produced before the resin film (2) is formed, or the maleimide compound (b) may be produced by heating when the resin film (2) is formed or after the resin film (2) is formed. It may be produced by reacting with the amine compound (c). When the polyimide compound (x) is contained in the resin film (2), the polyimide compound (x) is formed before the resin film (2) is formed from the viewpoint of preventing the minimum melt viscosity of the resin film (2) from increasing too much. ) Is preferably manufactured.
The amount of the maleimide compound (b) used in the production of the polyimide compound (x) is such that the equivalent of the maleimide group of the maleimide compound (b) is the same as that of the amine compound (c) from the viewpoint of preventing gelation and heat resistance. It is preferably in the range exceeding the equivalent of the primary amino group.
The reaction temperature of the maleimide compound (b) is preferably 70 to 200 ° C., and the reaction time is preferably 0.5 to 10 hours.

An organic solvent may be used in the production of the polyimide compound (x). The organic solvent is not particularly limited, and is, for example, an alcohol solvent such as ethanol, propanol, butanol, methyl cellosolve, butyl cellosolve, and propylene glycol monomethyl ether, a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone, and ethyl acetate ester. , Ester solvents such as γ-butyrolactone, ether solvents such as tetrahydrofuran, aromatic solvents such as toluene, xylene and mesitylen, nitrogen atom-containing solvents such as dimethylformamide, dimethylacetamide and N-methylpyrrolidone, dimethylsulfoxide and the like. Examples include sulfur atom-containing solvents. As the organic solvent, one kind may be used alone, or two or more kinds may be used in combination.
Among these, cyclohexanone, propylene glycol monomethyl ether, methyl cellosolve, and γ-butyrolactone are preferable from the viewpoint of solubility, and they are low in toxicity, highly volatile, and hardly remain as a residual solvent during the production of prepreg (5). Therefore, cyclohexanone, propylene glycol monomethyl ether, and dimethylacetamide are more preferable, and propylene glycol monomethyl ether is even more preferable.

[Thermosetting resin (d)]
The resin film (2) may or may not contain the thermosetting resin (d). However, the thermosetting resin (d) does not contain the polyimide compound (x). As the thermosetting resin (d), one type may be used alone, or two or more types may be used in combination.
Examples of the thermosetting resin (d) include an epoxy resin, a phenol resin, an unsaturated imide resin (however, the polyimide compound (x) is not included), a cyanate resin, an isocyanate resin, a benzoxazine resin, an oxetane resin, and an amino. Examples include resins (however, the component (c) is not included), unsaturated polyester resins, allyl resins, dicyclopentadiene resins, silicone resins, triazine resins, melamine resins (however, the components (c) are not included) and the like. Be done. Among these, from the viewpoint of moldability and electrical insulation, one or more selected from the group consisting of epoxy resin and cyanate resin is preferable, and epoxy resin is more preferable.

Examples of the epoxy resin include bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, α-naphthol / cresol novolac type epoxy resin, and bisphenol A. Novolak type epoxy resin, bisphenol F novolak type epoxy resin, stillben type epoxy resin, triazine skeleton-containing epoxy resin, fluorene skeleton-containing epoxy resin, triphenolphenol methane type epoxy resin, biphenyl type epoxy resin, xylylene type epoxy resin, biphenyl aralkyl type Polycyclic aromatic diglycidyl ether compounds such as epoxy resin, naphthalene type epoxy resin, dicyclopentadiene type epoxy resin, alicyclic epoxy resin, polyfunctional phenols and anthracene, and phosphorus-containing epoxy in which a phosphorus compound is introduced. Examples include resin. These may be used alone or in combination of two or more. Among these, biphenyl aralkyl type epoxy resin and α-naphthol / cresol novolak type epoxy resin are preferable from the viewpoint of heat resistance and flame retardancy.
One type of epoxy resin may be used alone, or two or more types may be used in combination.

The cyanate resin includes, for example, a novolak type cyanate resin; a bisphenol type cyanate resin such as a bisphenol A type cyanate resin, a bisphenol E type cyanate resin, and a tetramethylbisphenol F type cyanate resin; the cyanate resin is partially triazined. Prepolymers and the like can be mentioned. Among these, the novolak type cyanate resin is preferable from the viewpoint of heat resistance and flame retardancy.
One type of cyanate resin may be used alone, or two or more types may be used in combination.

When the resin film (2) contains the thermosetting resin (d), the content thereof is not particularly limited, but from the viewpoint of moldability, electrical insulation, and adhesive strength with the metal circuit, the resin film (2) It is preferably 1 to 40 parts by mass, more preferably 1 to 35 parts by mass, and further preferably 3 to 30 parts by mass with respect to 100 parts by mass of the total solid content of the resin component in the resin composition forming the above.

[Curing accelerator (e)]
The resin film (2) may or may not contain the curing accelerator (e).
Examples of the curing accelerator (e) include organic metal salts such as zinc naphthenate, cobalt naphthenate, tin octylate, cobalt octylate, bisacetylacetonate cobalt (II), and trisacetylacetonate cobalt (III); Examples thereof include organic phosphorus compounds; imidazole compounds and derivatives thereof; secondary amine compounds, tertiary amine compounds, and quaternary ammonium salts. In particular, as the curing accelerator (e) of the epoxy resin, an organic phosphorus compound; an imidazole compound and its derivative; a tertiary amine compound; a quaternary ammonium salt are preferable, and from the viewpoint of heat resistance and flame retardancy, it is preferable. The imidazole compound and its derivative are more preferable, and the organic phosphorus compound is more preferable from the viewpoint of low thermal expansion.
As the curing accelerator (e), one type may be used alone, or two or more types may be used in combination.

When the resin film (2) contains the curing accelerator (e), the content thereof is not particularly limited, but the total solid content of the resin components in the resin composition forming the resin film (2) is 100 parts by mass. On the other hand, 0.1 to 10 parts by mass is preferable, 0.1 to 5 parts by mass is more preferable, and 0.1 to 3 parts by mass is further preferable. When it is 0.1 part by mass or more, heat resistance and flame retardancy are good, and deterioration of thickness accuracy due to exudation during press molding tends to be suppressed. Further, if it is 10 parts by mass or less, there is a tendency that deterioration of heat resistance and aging stability can be suppressed.

[Inorganic filler (f)]
The resin film (2) may or may not contain the inorganic filler (f).
Examples of the inorganic filler (f) include silica, alumina, barium sulfate, talc, mica, kaolin, boehmite, beryllia, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, and magnesium hydroxide. , Aluminum hydroxide, Aluminum borate, Aluminum silicate, Calcium carbonate, Calcium silicate, Magnesium silicate, Zinc borate, Zinc succinate, Zinc oxide, Titanium oxide, Silicon carbide, Silicon nitride, Boron nitride, Baked clay, etc. Calcium, short glass fibers, glass powder, hollow glass beads and the like, and at least one selected from the group consisting of these is preferably used. As the glass, E glass, T glass, D glass and the like are preferably mentioned.

As the inorganic filler (f), silica is preferable from the viewpoint of dielectric properties, heat resistance and low thermal expansion. Examples of silica include precipitated silica manufactured by a wet method and having a high water content, and dry silica manufactured by a dry method and containing almost no bound water or the like. Further, examples of the dry silica include crushed silica, fumed silica, and fused silica (molten spherical silica) depending on the manufacturing method. The silica used in the inorganic filler (f) is preferably fused silica from the viewpoint of low thermal expansion and high fluidity when filled in a resin.

When fused spherical silica is used as the inorganic filler (f), the average particle size thereof is preferably 0.1 to 10 μm, more preferably 0.3 to 8 μm. By setting the average particle size of the molten spherical silica to 0.1 μm or more, good fluidity can be maintained when the resin is highly filled, and by further setting it to 10 μm or less, the probability of mixing coarse particles is reduced. It is possible to suppress the occurrence of defects caused by coarse particles. Here, the average particle size is the particle size at a point corresponding to exactly 50% of the volume when the cumulative frequency distribution curve by the particle size is obtained with the total volume of the particles as 100%, and the laser diffraction scattering method is used. It can be measured by the particle size distribution measuring device or the like used.
Further, the silica is preferably silica surface-treated with a silane coupling agent. When silica surface-treated with a silane coupling agent is used, the adhesive strength between the silica and the resin component is improved, the falling off of the silica is suppressed, and the surface roughness tends to be lowered. Examples of the silane coupling agent include an aminosilane-based coupling agent, an epoxysilane-based coupling agent, a phenylsilane-based coupling agent, an alkylsilane-based coupling agent, an alkenylsilane-based coupling agent, a siloxane-based coupling agent, and the like. Can be mentioned. Among these, aminosilane-based coupling agents are preferable.
It is also preferable that the silane coupling agent and the inorganic filler (f) are integrally blended without surface treatment with the silane coupling agent.

When the resin film (2) contains the inorganic filler (f), the content thereof is the solid of the resin component in the resin composition forming the resin film (2) from the viewpoint of low thermal expansion and circuit embedding property. It is preferably 20 to 300 parts by mass, and more preferably 40 to 200 parts by mass with respect to 100 parts by mass.

[Other ingredients]
The resin film (2) may or may not contain a flame retardant, an ultraviolet absorber, an antioxidant, a photopolymerization initiator, a fluorescent whitening agent, an adhesiveness improving agent, and the like.
Examples of the flame retardant include halogen-based flame retardants containing bromine and / or chlorine; phosphorus-based flame retardants such as triphenyl phosphate, tricresyl phosphate, trisdichloropropyl phosphate, phosphoric acid ester-based compounds, and red phosphorus; Nitrogen-based flame retardants such as guanidine acid, melamine sulfate, melamine polyphosphate, and melamine cyanurate; phosphazene-based flame retardants such as cyclophosphazene and polyphosphazene can be mentioned.
Examples of the ultraviolet absorber include benzotriazole-based ultraviolet absorbers and the like. Examples of the antioxidant include a hindered phenol-based antioxidant, a hindered amine-based antioxidant, and the like. Examples of the photopolymerization initiator include benzophenones, benzyl ketals, thioxanthone-based photopolymerization initiators and the like. Examples of the fluorescent whitening agent include a fluorescent whitening agent of a stilbene derivative. Examples of the adhesiveness improving agent include urea compounds such as ureasilane; coupling agents such as silane-based coupling agents, titanate-based coupling agents, and aluminate-based coupling agents.

The method for producing the resin film (2) is not particularly limited, and a known method can be used. For example, first, each component contained in the resin film (2) is usually mixed in the presence of an organic solvent to form a resin varnish having a solid content concentration of 40 to 90% by mass (preferably 50 to 80% by mass). do. At this time, the organic solvent may be, for example, a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone; an alcohol solvent such as methyl cellosolve; an ether solvent such as tetrahydrofuran; an aromatic solvent such as toluene, xylene or mesitylene. Examples include a solvent.
Next, the resin film (2) can be formed by applying the obtained resin varnish to the support, removing unnecessary organic solvents, and thermosetting (including semi-curing). The thermosetting conditions are as described above, and the process is carried out so that the minimum melt viscosity of the resin film (2) is 800 to 3,500 Pa · s.
By setting the solid content concentration of the resin varnish to 40 to 90% by mass, the ease of coating can be kept good, and the resin film (2) having an appropriate amount of the resin composition adhered can be obtained.

(Prepreg (5))
In the prepreg (5), the thermosetting resin composition is impregnated or coated on the fiber base material, or the resin film (2) formed from the thermosetting resin composition is bonded to the fiber base material. After that, it is semi-cured (B-staged), and the production method is not particularly limited, and a known prepreg production method can be used.
The thermosetting resin composition may contain a component different from the component that can be contained in the resin film (2), while the component that can be contained in the resin film (2) is contained. However, the latter is preferable from the viewpoint of the adhesiveness and adhesion of the resin film (2) to the prepreg (5). For example, the semi-cured product of the thermosetting resin composition constituting the prepreg (5) is a thermoplastic elastomer (a), a maleimide compound (b) having at least two N-substituted maleimide groups, and at least two second products. A compound containing an amine compound (c) having a primary amino group, a polyimide resin (x), a thermosetting resin (d), a curing accelerator (e), an inorganic filler (f), and the other components. May be. Each component is as described in the resin film (2), but as described above, the minimum melt viscosity of the resin film (2) is semi-curing of the thermosetting resin composition constituting the prepreg (5). It is preferably smaller than the minimum melt viscosity of the object. The method for adjusting the minimum melt viscosity is not particularly limited, but for example, a method for adjusting the content of each component, a method for selecting the type of each component, and a semi-curing condition for forming the resin film (2) are adjusted. (For example, a method of reducing the drying temperature or shortening the drying time compared to the semi-curing condition for forming the prepreg (5)), and adjusting the semi-curing condition for forming the prepreg (5). How to do it, etc. As a method for adjusting the content of each component, a method for adjusting the content of at least one selected from the group consisting of the curing accelerator (e) and the inorganic filler (f) is preferable.
The minimum melt viscosity of the semi-cured product of the thermosetting resin composition constituting the prepreg (5) may be, for example, 800 to 4,000 P a · s. However, as described above, the minimum melt viscosity of the resin film (2) is preferably smaller than the minimum melt viscosity of the semi-cured product of the thermosetting resin composition constituting the prepreg (5), and therefore, from this viewpoint. Is preferably 1,500 to 4,000 P a · s, more preferably 1,900 to 4,000 P a · s, and 2,000 to 4,000 P a · s. It is more preferably 2,300 to 4,000 Pa · s , and particularly preferably 2,300 to 4,000 Pa · s. If the minimum melt viscosity of the semi-cured product of the thermosetting resin composition constituting the prepreg (5) is higher than the melt viscosity of the resin film (2), it is possible to prevent the resin composition from seeping out during press molding. Therefore, it tends to be easy to improve the accuracy of the thickness of the laminated board.

As the fiber base material used in the prepreg (5), well-known materials used for various laminated plates for electrical insulating materials can be used. Examples of the material include inorganic fibers such as E glass, S glass, low dielectric glass, and Q glass; organic fibers such as low dielectric glass polyimide, polyester, and tetrafluoroethylene; and mixtures thereof. Inorganic fibers are particularly preferable, and low-dielectric glass and Q glass are more preferable, from the viewpoint of obtaining a base material having excellent dielectric properties.
These fiber substrates have shapes such as woven fabrics, non-woven fabrics, robinks, chopped strand mats, and surfaced mats.
The material and shape of the fiber base material are appropriately selected depending on the intended use and performance of the molded product, and if necessary, the fiber base material may be one type of material and one type of shape, or two types. It may be a fiber base material made of the above materials, or may be a fiber base material having two or more kinds of shapes. As the fiber base material, for example, one having a thickness of about 0.03 to 0.5 mm can be used. From the viewpoint of heat resistance, moisture resistance, processability, etc., these fiber base materials are preferably surface-treated with a silane coupling agent or the like, or mechanically opened.

Further, the prepreg (5) is required to have low thermal expansion from the viewpoint of reducing the warp of the package. It is generally known that the coefficient of thermal expansion of the prepreg (5) follows the Scapery equation shown below.
A≈ (ArErFr + AgEgFg) / (ErFr + EgFg)
(In the above formula, A is the coefficient of thermal expansion of the prepreg, Ar is the coefficient of thermal expansion of the resin composition, Er is the coefficient of elasticity of the resin composition, Fr is the volume fraction of the resin composition, and Ag is the coefficient of thermal expansion of the glass cloth. , Eg represents the coefficient of elasticity of the glass cloth, and Fg represents the volume fraction of the glass cloth.)
From the above Scapery equation, when glass cloth having the same physical characteristics is used at an arbitrary volume fraction, the prepreg (5) can be reduced in thermal expansion by reducing the elastic modulus and the coefficient of thermal expansion of the resin composition. I understand. Therefore, when glass cloth having the same physical properties at an arbitrary volume fraction is used, it is preferable to reduce the elastic modulus and the thermal expansion coefficient of the resin composition.

(Metal leaf)
In the step (iii), the metal of the metal foil that may be installed outside the prepreg (5) includes copper, gold, silver, nickel, platinum, molybdenum, ruthenium, aluminum, tungsten, iron, titanium, and chromium. , Or an alloy containing at least one of these metallic elements is preferable. As the alloy, copper-based alloys, aluminum-based alloys, and iron-based alloys are preferable. Examples of the copper-based alloy include copper-nickel alloys. Examples of the iron-based alloy include iron-nickel alloys (42 alloys). Among these, copper, nickel, and 42 alloy are more preferable as the metal, and copper is further preferable from the viewpoint of availability and cost.
The thickness of the metal foil is not particularly limited, but may be 3 to 210 μm, 5 to 140 μm, 5 to 50 μm, or 5 to 25 μm.

The metal leaf that may be installed further outside the prepreg (5) is not a metal leaf for circuit formation, but a metal leaf having a resin layer corresponding to electroless copper plating performed by a semi-additive method or the like. You may. The thermosetting resin composition contained in the resin layer is described in the same manner as the thermosetting resin composition, and may be the same as or different from the thermosetting resin composition. May be good. The thermosetting resin composition is not particularly limited, but preferably contains an epoxy resin. The epoxy resin will be described in the same manner as described above.

[Manufacturing method of printed wiring board and manufacturing method of semiconductor package]
The present invention also provides a method for manufacturing a printed wiring board, which comprises a step of forming a circuit pattern on the laminated board obtained by the manufacturing method of the present invention.
The present invention also provides a method for manufacturing a semiconductor package, which comprises a step of mounting a semiconductor element on a printed wiring board obtained by the above manufacturing method. More specifically, the semiconductor package can be manufactured by mounting a semiconductor element such as a semiconductor chip or a memory at a predetermined position on the multilayer printed wiring board and sealing the semiconductor element with a sealing resin or the like.

Next, the present invention will be described in more detail with reference to the following examples, but these examples do not limit the present invention.
The evaluation method or measurement method carried out in each example is as follows.

(1. Measurement method of minimum melt viscosity)
The resin film or prepreg prepared by the method described later was put in a plastic bag and kneaded, and only the resin composition was collected. Next, the collected resin was crushed in a mortar, weighed about 0.6 g, and molded into a disk-shaped tablet having a diameter of 20 mm by a tablet molding machine. Subsequently, this tablet was subjected to a temperature rise rate of 3 ° C./min, a load of 0.2 N, and a measurement temperature range of 50 to 200 ° C. using a rheometer (manufactured by Rheometer, device name: ARES-2K STD-FCO-STD). It was measured under the condition of. The results are shown in Table 2.

(2. Evaluation method of circuit embedding)
A wiring board in which a pseudo circuit pattern was formed was produced by drilling (through hole formation) and etching so that the residual copper ratio was 60% on the copper-clad laminate.
In each embodiment, the resin film (with PET film) shown in Table 2 is vacuum-laminated [step (i)] on one side of the wiring board under the conditions described in the embodiment, and then the PET film is removed [step (step (with PET film)). After ii)], the prepregs shown in Table 2 were arranged [step (iii)], while in each comparative example, the prepregs shown in Table 2 were directly arranged without using a resin film. Next, a copper foil having a thickness of 12 μm was arranged on both sides thereof to prepare a laminated board. Then, the laminated plate is sandwiched between 1.8 mm thick and 530 mm square SUS end plates, and using a multi-stage vacuum press, the temperature rise rate in the region of the product temperature of 60 to 160 ° C. is 3 to 4 ° C./min under a vacuum atmosphere. A copper-clad laminate was produced by pressing for 90 minutes under the conditions of a pressure of 3.0 MPa and a maximum holding temperature of 230 ° C.
The copper foil of the obtained copper-clad laminate is removed by etching, and through holes are visually observed from the side where the prepreg is not placed on the cured laminate, and the circuit embedding property is evaluated according to the following evaluation criteria, and molding is performed. It was used as an index of sex. A is excellent in moldability, B is inferior to A but good in moldability, and C is poor in moldability. The results are shown in Table 2.
A: There is no step on the surface of all through-hole portions, and the circuit embedding property is good.
B: There are 20% or less of the parts where a step can be confirmed on the surface of the through hole portion.
C: There are more than 20% of the parts where a step can be confirmed on the surface of the through hole portion.

(Preparation of polyimide compound (x))
The polyimide compound (x) was prepared according to the following production example and used in Examples and Comparative Examples.
[Production Example 1] Production of siloxane-Modified Polyimide (x-1) In a reaction vessel with a volume of 2 liters that can be heated and cooled equipped with a thermometer, a stirrer, and a water meter with a reflux cooling tube, both-ended diamine-modified siloxane [ Made by Shin-Etsu Chemical Industry Co., Ltd., trade name: X-22-161A, (c) component] 72 g, bis (4-maleimidephenyl) methane [(b) component] 252 g, and propylene glycol monomethyl ether 270 g. , 110 ° C. for 3 hours to obtain a siloxane-modified polyimide (x-1) -containing solution.

[Production Example 2] Production of siloxane-Modified Polyimide (x-2) In a reaction vessel with a volume of 2 liters that can be heated and cooled equipped with a thermometer, a stirrer, and a water meter with a reflux cooling tube, both-ended diamine-modified siloxane [ Made by Shin-Etsu Chemical Industry Co., Ltd., trade name: X-22-161B, (c) component] 85 g, 2,2-bis (4- (4-maleimidephenoxy) phenyl) propane [(b) component] 252 g, 270 g of propylene glycol monomethyl ether was added and reacted at 110 ° C. for 3 hours to obtain a siloxane-modified polyimide (x-2) -containing solution.

[Preparation of resin varnish]
Each component shown below is mixed at the blending ratio (unit: parts by mass) shown in Table 1 to prepare resin varnishes a to e having a non-volatile content (including an inorganic filler) of 65% by mass using methyl ethyl ketone as a solvent. bottom.

-Thermoplastic elastomer (a)
Tough Tech (registered trademark) M1913: Trade name, manufactured by Asahi Kasei Chemicals Co., Ltd., Carboxylic acid-modified hydrogenated styrene-butadiene copolymer resin Teisan Resin (registered trademark) SG-P3: Trade name, manufactured by Nagase Chemtex Co., Ltd., containing epoxy group Acrylic elastomer, weight average molecular weight 850,000

-Maleimide compound (b)
BMI-4000: Product name, manufactured by Daiwa Kasei Kogyo Co., Ltd., 2,2-bis [4- (4-maleimide phenoxy) phenyl] propane

-Amine compound (c)
X-22-161A: Trade name, manufactured by Shin-Etsu Chemical Industry Co., Ltd., both-terminal amino-modified siloxane compound, functional group equivalent of amino group: 800 g / mol
X-22-161B: Trade name, manufactured by Shin-Etsu Chemical Industry Co., Ltd., both-terminal amino-modified siloxane compound, functional group equivalent of amino group: 1,500 g / mol

-Polyimide compound (x)
(X-1): Solution containing siloxane-modified polyimide (x-1) prepared in Production Example 1 (x-2): Solution containing siloxane-modified polyimide (x-2) prepared in Production Example 2.

-Thermosetting resin (d)
NC-7000L: Product name, manufactured by Nippon Kayaku Co., Ltd., α-naphthol / cresol novolac type epoxy resin NC-3000H: Product name, manufactured by Nippon Kayaku Co., Ltd., biphenyl aralkyl type epoxy resin

・ Curing accelerator (e)
G-8009L: Product name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., isocyanate mask imidazole TPP-S: product name, manufactured by Hokuko Chemical Industry Co., Ltd., triphenylphosphine triphenylborane

-Inorganic filler (f)
(F-1) SC2050-KNK: Product name, manufactured by Admatex Co., Ltd., spherical fused silica, average particle size: 0.5 μm

[Manufacturing of resin film]
One of the resin varnishes a to e is applied to a PET film having a width of 580 mm (manufactured by Teijin DuPont Film Co., Ltd., trade name: G-2) with a coating width of 525 mm, and a resin film (PET film) having a thickness shown in Table 2 is applied. With) was prepared.

[Manufacturing of prepreg]
Any of the resin varnishes a to e was applied to a glass woven fabric using a coating machine, and then dried to remove a solvent and heat-cured. The coating amount was adjusted by the squeeze roll method, and a prepreg having the thickness shown in Table 2 was prepared.

[Examples 1 to 5]
In the method for evaluating the circuit embedding property, the conditions for vacuum laminating the resin film (with PET film) on the circuit forming surface were 130 ° C., 0.5 MPa, and a vacuum pressurization time of 60 seconds in the laminator.
Then, a laminated board (copper-clad laminated board) was obtained as described in the above-mentioned method for evaluating circuit embedding property. The obtained laminated board was evaluated for circuit embedding property according to the above method. The results are shown in Table 2.

[Comparative Examples 1 to 4]
A laminated board (copper-clad laminated board) was obtained as described in the above-mentioned method for evaluating circuit embedding property. The obtained laminated board was evaluated for circuit embedding property according to the above method. The results are shown in Table 2.

From Table 2, in the manufacturing method of the present invention, the circuit embedding property is improved even when a prepreg containing a thermosetting resin composition having a high melt viscosity is used as compared with the conventional manufacturing method of a laminated board. It can be seen that the formability is excellent. Further, comparing Example 3 and Comparative Example 3, although the overall thickness of the laminated board was made thinner than that of Comparative Example 3 in Example 3, the circuit embedding property was improved and the formability was excellent. It is shown. Further comparing Example 4 and Example 5, even in a composition having a high melt viscosity of the thermosetting resin composition constituting the prepreg, the circuit embedding property is further improved by using the resin film having the reduced melt viscosity. It has been shown to be improved and excellent in moldability.

Claims (11)

A method for manufacturing a laminated board, which comprises the following steps (i) to (iii) in this order.
The resin film below is a resin film containing a maleimide compound (b) having at least two N-substituted maleimide groups and an amine compound (c) having at least two primary amino groups. ,
The following resin film is a resin film containing a polyimide compound (x), and the polyimide compound (x) is a maleimide compound (b) having at least two N-substituted maleimide groups and at least two. It is a reaction product with the amine compound (c) having a primary amino group of.
Further, a method for producing a laminated board, wherein all of the components (c) are contained in both terminal amino-modified siloxane compounds.
(I) A step of laminating a resin film with a support having a minimum melt viscosity of the resin film of 800 to 3,500 Pa · s on a circuit board.
(Ii) A step of removing the support of the resin film with the support laminated on the circuit board.
(Iii) A step of laminating a prepreg on a resin film from which a support has been removed. The method for producing a laminated board according to claim 1, wherein the resin film contains a thermoplastic elastomer (a). The laminated plate according to claim 2 , wherein the content of the thermoplastic elastomer (a) is 1 to 60 parts by mass with respect to 100 parts by mass of the total resin components in the resin composition forming the resin film. Manufacturing method. For the laminating in the step (i), the resin film (4) with a support and the circuit board (1) are preheated, and then the crimping temperature is 60 to 160 ° C., the crimping pressure is 0.1 to 1.1 MPa, and the air pressure is 20 mmHg (26). .7 hPa) The method for producing a laminated board according to any one of claims 1 to 3, which is carried out under a reduced pressure of 7 hPa) or less. The method for producing a laminated board according to any one of claims 1 to 4, wherein the resin film contains a thermosetting resin (d). The method for producing a laminated board according to any one of claims 1 to 5, wherein the resin film contains a curing accelerator (e). The method for producing a laminated board according to any one of claims 1 to 6, wherein the resin film contains an inorganic filler (f). The method for producing a laminated board according to any one of claims 1 to 7, wherein the minimum melt viscosity of the resin film is smaller than the minimum melt viscosity of the semi-cured product of the thermosetting resin composition constituting the prepreg. The method for manufacturing a laminated board according to any one of claims 1 to 8, wherein the prepreg has a thickness of 10 to 70 μm. A method for manufacturing a printed wiring board, comprising a step of forming a circuit pattern on a laminated board obtained by the manufacturing method according to any one of claims 1 to 9. A method for manufacturing a semiconductor package, comprising a step of mounting a semiconductor element on a printed wiring board obtained by the manufacturing method according to claim 10.

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