JP6756107B2 - Resin film, resin film with support, prepreg, metal-clad laminate for high multilayer and high multilayer printed wiring board - Google Patents

Description

The present invention relates to a resin film for manufacturing a high-multilayer printed wiring board, a resin film with a support, a prepreg, a metal-clad laminate for high multilayer, and a high-multilayer printed wiring board.

The speed and capacity of signals used in mobile communication devices such as mobile phones, their base station devices, servers, network infrastructure devices such as routers, and electronic devices such as large computers are increasing year by year. Along with this, the printed wiring boards mounted on these electronic devices need to be compatible with high frequencies, and low relative permittivity and low dielectric loss tangent substrate materials that can reduce transmission loss are required. In recent years, as applications that handle such high-frequency signals, in addition to the above-mentioned electronic devices, practical application and practical planning of new systems that handle high-frequency wireless signals in the ITS field (automobiles, transportation system-related) and indoor short-range communication fields. It is expected that low transmission loss substrate materials will be further required for printed wiring boards mounted on these devices in the future.

In addition, due to recent environmental problems, mounting of electronic components with lead-free solder and flame retardancy with halogen-free have come to be required, so that materials for printed wiring boards have higher heat resistance and flame retardancy than before. Sex is needed.

Conventionally, fluororesins having low relative permittivity and dielectric loss tangent have been used as substrate materials for printed wiring boards that require low transmission loss. However, since fluororesin has low fluidity due to its high melting temperature and melting viscosity, there is a problem that press molding must be performed under high temperature and high pressure conditions. In addition, there are problems that workability, thermal expansion characteristics, dimensional stability, and adhesiveness to metal plating are insufficient for use in printed wiring board applications. In addition, it is difficult to bond or combine with other resin materials, and its use is limited. Fluororesin, which is a thermoplastic resin, tends to be unsuitable for applications that require high heat resistance and applications that require dielectric properties for temperature stability.

Therefore, polyphenylene ether (PPO, PPE) -based resins are conventionally known as heat-resistant thermoplastic polymers that exhibit excellent high-frequency characteristics, although they are not as good as fluororesins. However, in order to use it as a substrate material for a printed wiring board, it is necessary to have chemical resistance (solvent) resistance and high heat resistance that can withstand a wet process at the time of manufacturing the printed wiring board or a solder connection process at the time of mounting. Further, since polyphenylene ether is basically a high molecular weight material having a high melt viscosity, it has a problem of moldability like fluororesin.

Therefore, as a method for improving the chemical resistance (solvent) resistance, heat resistance and moldability, a method of using polyphenylene ether and a thermosetting resin in combination has been proposed. Specifically, a resin composition containing a polyphenylene ether and an epoxy resin (see, for example, Patent Document 1), and a resin composition using a polyphenylene ether and a cyanate ester resin having a low relative dielectric constant among thermosetting resins (for example). , Patent Document 2), a resin composition in which a bismaleimide compound exhibiting high heat resistance among thermosetting resins is used in combination with a polyphenylene ether (see, for example, Patent Document 3), a crosslinkable polymer such as a polybutadiene resin is added to the polyphenylene ether. A resin composition in combination (see, for example, Patent Document 4) and a resin composition in which a crosslinkable monomer such as triallyl isocyanurate (see, for example, Patent Document 5) are used in combination are disclosed.

However, the resin compositions described in Patent Documents 1 to 5 are comprehensively inadequate in high frequency characteristics in the GHz region, adhesiveness to conductors, thermal expansion characteristics, and flame retardancy, or are thermoset with polyphenylene ether. Heat resistance may decrease due to low compatibility with the sex resin. In particular, in order to suppress the deterioration of high frequency characteristics, it is necessary to increase the ratio of polyphenylene ether in the resin composition, but in that case, as a result, the above-mentioned chemical resistance (solvent) resistance, heat resistance and moldability are insufficient. Tend.

Therefore, in order to improve the compatibility between the polyphenylene ether and the thermosetting resin and suppress the decrease in heat resistance, triallyl isocyanurate, polybutadiene, etc. are used in combination with the polyphenylene ether to which an unsaturated double bond group or the like is added or grafted. Resin composition (for example, Patent Document 6), a resin in which a low molecular weight polyphenylene ether and a thermosetting resin are used in combination for the purpose of improving compatibility, moldability, etc. between the polyphenylene ether and the thermosetting resin. While reducing the molecular weight of the composition (for example, Patent Document 7) or polyphenylene ether, a reactive group (ethenylbenzyl group, etc.) with triallyl isocyanurate is introduced at the terminal of the polyphenylene ether molecule, and this and triaryl isocyanurate are introduced. (For example, Patent Document 8) has been proposed in combination with the above. Similarly, a method is known in which a functional group such as an amino group is introduced into the polyphenylene ether at the same time as the molecular weight is reduced by reacting the polyphenylene ether with various phenol species (for example, Patent Document 9).

On the other hand, the present inventors also have compatibility, heat resistance, and thermal expansion characteristics by semi-IPNizing the varnish (resin composition) at the manufacturing stage (A stage stage) based on the polyphenylene ether resin and the polybutadiene resin. We have proposed a resin composition (for example, Patent Document 10) that can improve the adhesiveness with a conductor.

JP-A-58-69046 Special Publication No. 61-18937 Japanese Unexamined Patent Publication No. 56-133355 JP-A-59-193929 Japanese Unexamined Patent Publication No. 3-275760 Japanese Unexamined Patent Publication No. 6-184213 JP-A-2002-265777 Special Table 2006-516297 Special Table 2000-5009097 Japanese Unexamined Patent Publication No. 2008-95061

Although the resin composition of Patent Document 6 is improved from the viewpoint of compatibility, the improvement of moldability due to the high frequency characteristics and the high melt viscosity in the GHz band due to the introduction of polar groups is still insufficient. Further, the resin composition of Patent Document 7 is improved in compatibility with a thermosetting resin and moldability by reducing the molecular weight of polyphenylene ether, but has normal high frequency characteristics, heat resistance, and glass transition temperature. It tends to be lower than when polyphenylene ether is used. Although the resin composition of Patent Document 8 whose main purpose is to solve the problems of Patent Document 7 and the like has improved heat resistance, a reactive group is introduced at the terminal due to the effect of reducing the molecular weight of polyphenylene ether. However, there are problems that the glass transition temperature tends to be low, the high frequency characteristics are slightly deteriorated, and the raw material cost and the process cost at the time of introducing the ethenylbenzyl group are very high. Since all of the resin compositions of Patent Documents 6 to 8 use triallyl isocyanurate as a thermosetting resin, they tend to be slightly inferior in thermal expansion characteristics, adhesion to a conductor, and flame retardancy. Moreover, since triallyl isocyanurate, which is a liquid crosslinkable monomer, is highly volatile even at a relatively low temperature, there is a problem that the working environment (contamination) during prepreg production (coating and drying) is poor, and unreacted components even after curing. There is also a problem that outgas is likely to be generated in the manufacturing process of the printed wiring board. Further, when a composition in which a thermosetting resin is used in combination with the polyphenylene ether obtained by the method of Patent Document 9 is used, compatibility and moldability are improved in the same manner as described above, but heat resistance, glass transition temperature and high frequency are improved. The characteristics also tend to deteriorate, and the flame retardancy may not be sufficient.

In recent years, the substrate material for printed wiring boards has higher density, high reliability, and compatibility with environmental considerations, in addition to high frequency, so it has higher adhesiveness to conductors, lower thermal expansion characteristics, and higher temperature. Glass transition temperature, high flame retardancy, etc. are required.

For example, in order to maintain high-frequency characteristics (suppress transmission loss deterioration due to conductor roughness, etc.), and to ensure fine wiring formability and high reflow heat resistance, the adhesiveness with the conductor is on the adhesive surface side with the resin. It is desired that the peeling strength of the copper foil when using a low profile copper foil (Rz: 1 to 2 μm) having a very small surface roughness is 0.6 kN / m or more.

In addition, the substrate material for printed wiring boards used for network-related equipment such as servers and routers needs to have a high number of layers as the density increases, and high reflow heat resistance and through-hole reliability are required. It is desired that the glass transition temperature, which serves as a guideline for these, is 200 ° C. or higher, and that the low thermal expansion characteristics (Z direction, Tg or lower) are 45 ppm / ° C. or lower, and further 40 ppm / ° C. or lower. There is. Here, it is effective to apply an inorganic filler in the resin composition to develop low thermal expansion, but in a high-multilayer printed wiring board, an inorganic filler is used to ensure resin flowability for circuit filling. Usage is limited. Therefore, it is desirable to secure the above-mentioned required value even when the blending amount of the inorganic filler is relatively small, such as 25% by volume or less of the whole resin composition.

Of course, as high frequency characteristics, excellent dielectric properties in a higher frequency band are required. For example, the relative permittivity of a substrate material when a general E glass substrate is composited is 3.7 or less, and further. Is desired to be 3.6 or less, and the dielectric loss tangent is desired to be 0.007 or less, and further to 0.006 or less. Moreover, in general, the substrate material tends to have a higher dielectric loss tangent as the frequency increases, but there is an increasing need to satisfy the above-mentioned required value in the 10 GHz band or higher instead of the conventional dielectric characteristic value in 1 to 5 GHz. There is.

In view of this situation, the present invention is a resin film for manufacturing a high-multilayer printed wiring board, which has high frequency characteristics (low dielectric constant, low dielectric loss tangent), adhesiveness to a conductor, heat resistance and low moisture absorption. , A resin film with a support, a prepreg, a metal-clad laminate for high multilayer, and a high-multilayer printed wiring board.

As a result of diligent studies to solve the above problems, the present inventors have found that the above problems can be solved by containing an imide-extended long-chain bismaleimide resin in a resin film for manufacturing a high-multilayer printed wiring board, and the present invention has been made. Has been completed.

［式（Ｉ）中、Ｒ_１は４価の有機基を示す。］
［３］前記飽和又は不飽和の２価の炭化水素基の炭素数が８〜１００である、［１］又は［２］に記載の樹脂フィルム。
［４］前記飽和又は不飽和の２価の炭化水素基が下記式（ＩＩ）で表される基である、［１］又は［２］に記載の樹脂フィルム。

［式（ＩＩ）中、Ｒ_２及びＲ_３は各々独立に炭素数４〜５０のアルキレン基を示し、Ｒ_４は炭素数４〜５０のアルキル基を示し、Ｒ_５は炭素数２〜５０のアルキル基を示す。］
［５］前記化合物の重量平均分子量が５００〜１００００である、［１］〜［４］のいずれかに記載の樹脂フィルム。
［６］無機充填剤を更に含有する、［１］〜［５］のいずれかに記載の樹脂フィルム。
［７］［１］〜［６］のいずれかに記載の樹脂フィルムと、支持基材とを有する高多層印刷配線板製造用の支持体付き樹脂フィルム。
［８］［１］〜［６］のいずれかに記載の樹脂フィルムと、シート状繊維補強基材とを有する、高多層印刷配線板製造用のプリプレグ。
［９］［１］〜［６］のいずれかに記載の樹脂フィルムの硬化物を含む樹脂層と、導体層とを有する高多層用金属張積層板。
［１０］［１］〜［６］のいずれかに記載の樹脂フィルムの硬化物を含む樹脂層と、回路層とを備える、高多層印刷配線板。 That is, the present invention includes the following aspects.
[1] A resin film for producing a high-multilayer printed wiring board containing a maleimide group, a divalent group having at least two imide bonds, and a compound having a saturated or unsaturated divalent hydrocarbon group.
[2] The resin film according to [1], wherein the divalent group having at least two imide bonds is a group represented by the following formula (I).

[In formula (I), R ₁ represents a tetravalent organic group. ]
[3] The resin film according to [1] or [2], wherein the saturated or unsaturated divalent hydrocarbon group has 8 to 100 carbon atoms.
[4] The resin film according to [1] or [2], wherein the saturated or unsaturated divalent hydrocarbon group is a group represented by the following formula (II).

[In formula (II), R ₂ and R ₃ each independently represent an alkylene group having _{4 to} 50 carbon atoms, R ₄ represents an alkyl group having _{4 to} 50 carbon atoms, and R ₅ has 2 to 50 carbon atoms. Indicates an alkyl group. ]
[5] The resin film according to any one of [1] to [4], wherein the weight average molecular weight of the compound is 500 to 10000.
[6] The resin film according to any one of [1] to [5], further containing an inorganic filler.
[7] A resin film with a support for manufacturing a high-multilayer printed wiring board having the resin film according to any one of [1] to [6] and a support base material.
[8] A prepreg for manufacturing a high-multilayer printed wiring board having the resin film according to any one of [1] to [6] and a sheet-shaped fiber reinforced base material.
[9] A high-multilayer metal-clad laminate having a resin layer containing a cured product of the resin film according to any one of [1] to [6] and a conductor layer.
[10] A high-multilayer printed wiring board comprising a resin layer containing a cured product of the resin film according to any one of [1] to [6] and a circuit layer.

The resin film for manufacturing a high-multilayer printed wiring board of the present invention has excellent dielectric properties that both the relative permittivity and the dielectric loss tangent are low in the high frequency region. Therefore, when a metal foil is laminated on the surface (one side or both sides) of the resin film to form a metal-clad cured resin film (metal-clad laminated plate), a resin film that does not satisfy the constituent requirements of the present invention is used. In comparison, excellent dielectric properties in the high frequency region can be obtained.

Further, conventionally, in a resin film for manufacturing a high-multilayer printed wiring board, when a glass cloth or the like is not arranged in the resin composition, the handleability of the resin film is deteriorated and the strength tends not to be sufficiently maintained. On the other hand, since the resin film according to the present invention is formed from a resin composition having a flexible long-chain aliphatic skeleton, it is thin and easy to handle (tackiness, even without a glass cloth or the like. It is also excellent in cracking, powder falling, etc.).

Further, as described above, when a conventional resin film or the like is applied in combination with a low profile foil, it is difficult to sufficiently obtain adhesiveness to the low profile foil, heat resistance, dielectric properties in a high frequency region, and the like. On the other hand, the resin film according to the present invention has a sufficiently high peeling strength against a low profile foil or the like. Therefore, the low profile foil can be used without any problem, and a high-multilayer printed wiring board with sufficiently reduced transmission loss can be provided.

Further, the resin film according to the present invention can simultaneously achieve excellent appearance and multi-layer moldability, and is also excellent in heat resistance and moisture resistance. In addition, the metal-clad cured resin film obtained by using the resin film for manufacturing a high-multilayer printed wiring board has high solder heat resistance that can withstand the solder connection process at the time of mounting, and also has excellent moisture absorption resistance. It is also suitable for outdoor use.

According to the present invention, a resin film support for manufacturing a high-multilayer printed wiring board, which has good dielectric properties in a high frequency region and has a high level of adhesion to a conductor such as a metal foil, heat resistance, and low moisture absorption. A resin film with a prepreg, a metal-clad laminate for high multilayer, and a high-multilayer printed wiring board can be provided.

It is the schematic which shows the manufacturing process of the high multilayer printed wiring board which concerns on this embodiment. It is a schematic diagram which shows the manufacturing process of the inner layer circuit board. It is the schematic which shows the manufacturing process of the high multilayer printed wiring board which concerns on this embodiment. It is the schematic which shows the manufacturing process of the conventional high multilayer printed wiring board.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings as necessary. However, the present invention is not limited to the following embodiments. In the present specification, the high-multilayer printed wiring board refers to a printed wiring board having three or more transmission circuit layers of the printed wiring board. Further, in the present specification, the high frequency region refers to a region of 300 MHz to 300 GHz, and a frequency region used particularly for high multilayer layers refers to a region of 3 GHz to 300 GHz.

The resin film for manufacturing a high-multilayer printed wiring board according to the present embodiment not only has high-frequency characteristics and moisture resistance that are comparable to those of a fluororesin type and exceed those of a polyphenylene ether resin type, but also have high adhesiveness, high heat resistance, and resistance. It has chemical contamination properties. As a result, the resin film for manufacturing such a high-multilayer printed wiring board can be applied to applications in a high frequency region including a millimeter wave signal. Hereinafter, the present embodiment will be described in detail.

[Resin film]
The resin film for producing the high multilayer printed wiring board according to the present embodiment contains a maleimide group, a divalent group having at least two imide bonds, and a compound having a saturated or unsaturated divalent hydrocarbon group. To do. The resin film according to the present embodiment is produced by using a resin composition containing an imide-extended long-chain bismaleimide resin. As used herein, the term "imide extension" means that a compound contains at least one imide moiety at a position other than the end of the molecule. Further, in the present specification, the resin composition containing a solvent is also referred to as a resin varnish.

(Imide extended long chain bismaleimide resin)
A compound having (a) a maleimide group, (b) a divalent group having at least two imide bonds, and (c) a saturated or unsaturated divalent hydrocarbon group according to the present embodiment is referred to as a component (A). There is. Further, (a) a maleimide group has a structure (a), (b) a divalent group having at least two imide bonds has a structure (b), and (c) a saturated or unsaturated divalent hydrocarbon group has a structure (a). c) Sometimes. By using the component (A), a resin composition having high frequency characteristics and high adhesiveness to a conductor can be obtained.

(A) The maleimide group is not particularly limited and is a general maleimide group. (A) The maleimide group may be bonded to an aromatic ring or an aliphatic chain, but from the viewpoint of dielectric properties, it is preferably bonded to the aliphatic chain.

(B) The divalent group having at least two imide bonds is not particularly limited, and examples thereof include a group represented by the following formula (I).

In formula (I), R ₁ represents a tetravalent organic group. R ₁ is not particularly limited as long as it is a tetravalent organic group, but for example, from the viewpoint of handleability, it may be a hydrocarbon group having 1 to 100 carbon atoms, or a hydrocarbon group having 2 to 50 carbon atoms. It may be a hydrocarbon group having 4 to 30 carbon atoms.

R ₁ may be a substituted or unsubstituted siloxane moiety. Examples of the siloxane moiety include structures derived from dimethylsiloxane, methylphenylsiloxane, diphenylsiloxane, and the like.

When R ₁ is substituted, the substituents include, for example, an alkyl group, an alkenyl group, an alkynyl group, a hydroxyl group, an alkoxy group, a mercapto group, a cycloalkyl group, a substituted cycloalkyl group, a heterocyclic group, a substituted heterocyclic group. , Aryl group, substituted aryl group, heteroaryl group, substituted heteroaryl group, aryloxy group, substituted aryloxy group, halogen atom, haloalkyl group, cyano group, nitro group, nitroso group, amino group, amide group, -C ( O) H, -NR _x C (O) -N (R _x ) ₂ , -OC (O) -N (R _x ) ₂ , acyl group, oxyacyl group, carboxyl group, carbamate group, sulfonamide group, etc. Be done. Here, R _x represents a hydrogen atom or an alkyl group. One type or two or more types of these substituents can be selected according to the purpose, application and the like.

As R ₁ , for example, a tetravalent residue of an acid anhydride having two or more anhydride rings in one molecule, that is, an acid anhydride group (-C (= O) OC (=) A tetravalent group excluding two O)-) is preferable. Examples of the acid anhydride include compounds described below.

From the viewpoint of mechanical strength, R ₁ is preferably aromatic, and more preferably a group obtained by removing two acid anhydride groups from pyromellitic anhydride. That is, the structure (b) is more preferably a group represented by the following formula (III).

From the viewpoint of fluidity and circuit embedding property, it is preferable that a plurality of structures (b) are present in the component (A). In that case, the structures (b) may be the same or different. The number of structures (b) in the component (A) is preferably 2 to 40, more preferably 2 to 20, and even more preferably 2 to 10.

From the viewpoint of the dielectric property, the structure (b) may be a group represented by the following formula (IV) or the following formula (V).

The structure (c) is not particularly limited, and may be linear, branched, or cyclic. Further, the saturated or unsaturated divalent hydrocarbon group may have 8 to 100 carbon atoms. The structure (c) is preferably an alkylene group which may have a branch having 8 to 100 carbon atoms, and more preferably an alkylene group which may have a branch having 10 to 70 carbon atoms. It is more preferable that the alkylene group may have a branch having 15 to 50 carbon atoms. When the component (A) has the structure (c), the flexibility of the resin composition according to the present embodiment is improved, and the handleability (tackiness, cracking, powder removal) of the resin film produced from the resin composition is improved. Etc.) and it is possible to increase the strength. Further, the structure (c) having the above-mentioned carbon number is preferable because the molecular structure can be easily made three-dimensional and the free volume of the polymer can be increased to reduce the density, that is, the dielectric constant.

The structure (c) includes, for example, an alkylene group such as a nonylene group, a decylene group, an undecylene group, a dodecylene group, a tetradecylene group, a hexadecylene group, an octadecylene group and a nonadesilene group; an arylene group such as a benzylene group, a phenylene group and a naphthylene group; Aliren alkylene groups such as phenylene methylene group, phenylene ethylene group, benzyl propylene group, naphthylene methylene group and naphthylene ethylene group; allylene alkylene groups such as phenylenedi methylene group and phenylenedi ethylene group can be mentioned.

From the viewpoints of high frequency characteristics, low thermal expansion characteristics, adhesiveness to conductors, heat resistance and low hygroscopicity, the group represented by the following formula (II) as the structure (c) is particularly preferable.

In formula (II), R ₂ and R ₃ each independently represent an alkylene group having 4 to 50 carbon atoms. From the viewpoint of further improvement of flexibility and easiness of synthesis, R ₂ and R ₃ are each independently preferably an alkylene group having 5 to 25 carbon atoms, and preferably an alkylene group having 6 to 10 carbon atoms. More preferably, it is an alkylene group having 7 to 10 carbon atoms.

In formula (II), R ₄ represents an alkyl group having ₄ to 50 carbon atoms. From the viewpoint of further improvement and ease of synthesis of flexibility, it is preferred that R ₄ is an alkyl group having 5 to 25 carbon atoms, more preferably an alkyl group having 6 to 10 carbon atoms, the carbon number 7 to It is more preferably an alkyl group of 10.

In formula (II), R ₅ represents an alkyl group having 2 to 50 carbon atoms. From the viewpoint of further improvement and ease of synthesis of flexibility, it is preferable that R ₅ is an alkyl group having 3 to 25 carbon atoms, more preferably an alkyl group having 4 to 10 carbon atoms, carbon atoms 5 It is more preferably an alkyl group of 8.

From the viewpoint of fluidity and circuit embedding property, it is preferable that a plurality of structures (c) are present in the component (A). In that case, the structures (c) may be the same or different. For example, it is preferable that 2 to 40 structures (c) are present in the component (A), more preferably 2 to 20 structures (c) are present, and 2 to 10 structures (c) are present. Is even more preferable.

The content of the component (A) in the resin film is not particularly limited. From the viewpoint of heat resistance, the content of the component (A) is preferably 2 to 98% by mass, more preferably 10 to 90% by mass, and 10 to 50% by mass with respect to the total mass of the resin film. Is more preferable, and 15 to 30% by mass is particularly preferable.

The molecular weight of the component (A) is not particularly limited. From the viewpoint of handleability, fluidity, and circuit embedding property, the weight average molecular weight (Mw) of the component (A) is preferably 500 to 10000, more preferably 1000 to 9000, and 1500 to 9000. Is even more preferable, and it is even more preferably 1500 to 7000, and particularly preferably 1700 to 5000.

The Mw of the component (A) can be measured by a gel permeation chromatography (GPC) method.

The measurement conditions of GPC are as follows.
Pump: L-6200 type [manufactured by Hitachi High-Technologies Corporation]
Detector: L-3300 type RI [manufactured by Hitachi High-Technologies Corporation]
Column oven: L-655A-52 [manufactured by Hitachi High-Technologies Corporation]
Guard column and column: TSK Guardcolum HHR-L + TSKgel G4000HHR + TSKgel G2000HHR [All manufactured by Tosoh Corporation, product name]
Column size: 6.0 x 40 mm (guard column), 7.8 x 300 mm (column)
Eluent: tetrahydrofuran Sample concentration: 30 mg / 5 mL
Injection volume: 20 μL
Flow rate: 1.00 mL / min Measurement temperature: 40 ° C

(A) The method for producing the component is not limited. The component (A) may be prepared, for example, by reacting an acid anhydride with a diamine to synthesize an amine-terminated compound, and then reacting the amine-terminated compound with an excess of maleic anhydride.

Examples of the acid anhydride include pyromellitic anhydride, maleic anhydride, succinic anhydride, 3,3', 4,4'-benzophenonetetracarboxylic dianhydride, 3,3', 4,4'-biphenyl. Examples thereof include tetracarboxylic dianhydride and 3,3', 4,4'-diphenylsulfonetetracarboxylic dianhydride. These acid anhydrides may be used alone or in combination of two or more, depending on the purpose, application and the like. As described above, as R ₁ of the above formula (I), a tetravalent organic group derived from the acid anhydride as described above can be used. From the viewpoint of better dielectric properties, the acid anhydride is preferably pyromellitic anhydride.

Examples of the diamine include diamine diamine, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 1,3-bis (4-aminophenoxy) benzene, and 4,4'-bis (4-amino). Phenoxy) biphenyl, 4,4'-diamino-3,3'-dihydroxybiphenyl, 1,3-bis [2- (4-aminophenyl) -2-propyl] benzene, 1,4-bis [2- (4) -Aminophenyl) -2-propyl] benzene, polyoxyalkylenediamine, [3,4-bis (1-aminoheptyl) -6-hexyl-5- (1-octenyl)] cyclohexene and the like. These may be used alone or in combination of two or more depending on the purpose, application and the like.

The component (A) may be, for example, the following compound.

In the formula, R and Q each independently represent a divalent organic group. The same R as the above-mentioned structure (c) can be used, and the same Q as the above-mentioned R ₁ can be used. Further, n represents an integer of 1 to 10.

As the component (A), a commercially available compound can also be used. Examples of commercially available compounds include Designer Moleculars Inc. Products manufactured by BMI-1500, BMI-1700, BMI-3000, BMI-5000, BMI-9000 (all are trade names) and the like. From the viewpoint of obtaining better high frequency characteristics, it is more preferable to use BMI-3000 as the component (A).

BMI-1500 has a structure represented by the formula (XII-1), BMI-1700 has a structure represented by the formula (XII-2), and BMI-3000, BMI-5000 and BMI- 9000 is presumed to have the structure of formula (XII-3). In formulas (XII-1) to (XII-3), n represents an integer of 1-10.

<(B) Maleimide group-containing compound>
The resin film according to this embodiment can further contain a maleimide group-containing compound different from the component (A). The maleimide group-containing compound may be referred to as component (B). In addition, the compound which can correspond to both the component (A) and the component (B) shall belong to the component (A). By using the component (B), the resin film is particularly excellent in low thermal expansion characteristics. That is, in the resin film according to the present embodiment, by using the component (A) and the component (B) in combination, it is possible to further improve the low thermal expansion property and the like while maintaining good dielectric properties. The reason for this is that the cured product obtained from the resin film containing the component (A) and the component (B) is composed of a structural unit composed of the component (A) having low dielectric properties and a component (B) having low thermal expansion. It is presumed that this is because it contains a polymer having a structural unit.

That is, it is preferable that the maleimide group-containing compound (B) has a lower coefficient of thermal expansion than the component (A). As the component (B) having a lower coefficient of thermal expansion than the component (A), for example, a maleimide group-containing compound having a molecular weight lower than that of the component (A), a maleimide group-containing compound having a larger aromatic ring than the component (A), and the like. Examples thereof include maleimide group-containing compounds having a main chain shorter than that of component (A).

The content of the component (B) in the resin film is not particularly limited. From the viewpoint of low thermal expansion, the content of the component (B) is preferably 1 to 20% by mass, more preferably 2 to 15% by mass, and 5 to 10% by mass with respect to the total mass of the resin film. It is more preferably%.

The blending ratio of the component (A) and the component (B) in the resin composition is not particularly limited. From the viewpoint of the dielectric property and the low coefficient of thermal expansion, the mass ratio (B) / (A) of the component (A) to the component (B) is preferably 0.01 to 3, preferably 0.03 to 2. More preferably, it is more preferably 0.05 to 1.

The maleimide group-containing compound (B) is not particularly limited, but preferably has an aromatic ring. Since the aromatic ring is rigid and has a low thermal expansion, the coefficient of thermal expansion can be further reduced by using the component (B) having an aromatic ring. The maleimide group may be bonded to an aromatic ring or an aliphatic chain, but from the viewpoint of dielectric properties, it is preferably bonded to an aromatic ring. That is, the component (B) preferably has a structure in which a maleimide group is bonded to an aromatic ring. The component (B) is also preferably a polymaleimide compound containing two or more maleimide groups.

Specific examples of the component (B) include 1,2-dimaleimideethane, 1,3-dimaleimidepropane, bis (4-maleimidephenyl) methane, bis (3-ethyl-4-maleimidephenyl) methane, and bis ( 3-Ethyl-5-methyl-4-maleimidephenyl) methane, 2,7-dimaleimidefluorene, N, N'-(1,3-phenylene) bismaleimide, N, N'-(1,3- (4) -Methylphenylene)) bismaleimide, bis (4-maleimidephenyl) sulfone, bis (4-maleimidephenyl) sulfide, bis (4-maleimidephenyl) ether, 1,3-bis (3-maleimidephenoxy) benzene, 1,3-bis (3- (3-maleimidephenoxy) phenoxy) benzene, bis (4-maleimidephenyl) ketone, 2,2-bis (4- (4-maleimidephenoxy) phenyl) propane, bis (4-( 4-Maleimidephenoxy) phenyl) sulfone, bis [4- (4-maleimidephenoxy) phenyl] sulfoxide, 4,4'-bis (3-maleimidephenoxy) biphenyl, 1,3-bis (2- (3-maleimidephenyl) ) Ppropyl) benzene, 1,3-bis (1- (4- (3-maleimidephenoxy) phenyl) -1-propyl) benzene, bis (maleimidecyclohexyl) methane, 2,2-bis [4- (3-maleimide) Phenoxy) phenyl] -1,1,1,3,3,3-hexafluoropropane, bis (maleimidephenyl) thiophene and the like. These may be used alone or in combination of two or more. Among these, bis (3-ethyl-5-methyl-4-maleimidephenyl) methane is preferably used from the viewpoint of further lowering the hygroscopicity and the coefficient of thermal expansion. From the viewpoint of further increasing the breaking strength and the metal foil peeling strength of the resin film formed from the resin composition, 2,2-bis (4- (4-maleimidephenoxy) phenyl) propane is used as the component (B). It is preferable to use it.

From the viewpoint of moldability, as the maleimide group-containing compound (B), for example, a compound represented by the following formula (VI) is preferable.

In the formula (VI), A ₄ represents a residue represented by the following formula (VII), (VIII), (IX) or (X), and A ₅ represents a residue represented by the following formula (XI). Shown.

In formula (VII), R ₁₀ independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 5 carbon atoms, or a halogen atom.

In formula (VIII), R ₁₁ and R ₁₂ each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom, and A ₆ is an alkylene group or an alkylidene group having 1 to 5 carbon atoms. , Ether group, sulfide group, sulfonyl group, ketone group, single bond or residue represented by the following formula (VIII-1).

In formula (VIII-1), R ₁₃ and R ₁₄ each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom, and A ₇ is an alkylene group having 1 to 5 carbon atoms. Shows an isopropylidene group, an ether group, a sulfide group, a sulfonyl group, a ketone group or a single bond.

In formula (IX), i is an integer of 1-10.

In formula (X), R ₁₅ and R ₁₆ each independently represent a hydrogen atom or an aliphatic hydrocarbon group having 1 to 5 carbon atoms, and j is an integer of 1 to 8.

In formula (XI), R ₁₇ and R ₁₈ each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 5 carbon atoms, an alkoxy group having 1 to 5 carbon atoms, a hydroxyl group or a halogen atom, and A ₈ is , Alkylene group or alkylidene group having 1 to 5 carbon atoms, ether group, sulfide group, sulfonyl group, ketone group, fluorenylene group, single bond, residue represented by the following formula (XI-1) or the following formula (XI-). The residue represented by 2) is shown.

In the formula (XI-1), R ₁₉ and R ₂₀ each independently represent a hydrogen atom, an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom, and A ₉ is an alkylene group having 1 to 5 carbon atoms. , Isopropylidene group, m-phenylenediisopropylidene group, p-phenylenediisopropylidene group, ether group, sulfide group, sulfonyl group, ketone group or single bond.

In formula (XI-2), R ₂₁ independently represents a hydrogen atom, an aliphatic hydrocarbon group having 1 to 5 carbon atoms or a halogen atom, and A ₁₀ and A ₁₁ independently represent 1 to 5 carbon atoms, respectively. Indicates an alkylene group, an isopropylidene group, an ether group, a sulfide group, a sulfonyl group, a ketone group or a single bond.

The maleimide group-containing compound (B) is preferably used as a polyaminobismaleimide compound from the viewpoints of solubility in an organic solvent, high frequency characteristics, high adhesiveness to a conductor, moldability of a prepreg, and the like. The polyaminobismaleimide compound can be obtained, for example, by carrying out a Michael addition reaction of a compound having two maleimide groups at the terminal and an aromatic diamine compound having two primary amino groups in the molecule in an organic solvent.

The aromatic diamine compound having two primary amino groups in the molecule is not particularly limited, and for example, 4,4'-diaminodiphenylmethane, 4,4'-diamino-3,3'-dimethyl-diphenylmethane, 2,2 '-Dimethyl-4,4'-diaminobiphenyl, 2,2-bis (4- (4-aminophenoxy) phenyl) propane, 4,4'-[1,3-phenylenebis (1-methylethylidene)] bisaniline , 4,4'-[1,4-phenylenebis (1-methylethylidene)] bisaniline and the like. These may be used alone or in combination of two or more.

In addition, from the viewpoint of high solubility in organic solvents, high reaction rate during synthesis, and high heat resistance, 4,4'-diaminodiphenylmethane and 4,4'-diamino-3,3'-dimethyl -Diphenylmethane is preferred. These may be used alone or in combination of two or more depending on the purpose, application and the like.

The organic solvent used in producing the polyaminobismaleimide compound is not particularly limited, and for example, alcohols such as methanol, ethanol, butanol, butyl cellosolve, ethylene glycol monomethyl ether, and propylene glycol monomethyl ether; acetone, methyl ethyl ketone, and methyl. Ketones such as isobutyl ketone and cyclohexanone; aromatic hydrocarbons such as toluene, xylene and mesitylene; esters such as methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate and ethyl acetate; N, N-dimethylformamide, N, Examples thereof include nitrogen-containing substances such as N-dimethylacetamide and N-methyl-2-pyrrolidone. One of these may be used alone, or two or more thereof may be mixed and used. Among these, methyl ethyl ketone, cyclohexanone, propylene glycol monomethyl ether, N, N-dimethylformamide and N, N-dimethylacetamide are preferable from the viewpoint of solubility.

(catalyst)
The resin composition of the present embodiment may further contain a catalyst for accelerating the curing of the component (A). The content of the catalyst is not particularly limited, but may be 0.1 to 5% by mass with respect to the total mass of the resin composition. As the catalyst, for example, a peroxide, an azo compound or the like can be used.

Examples of the peroxide include dicumyl peroxide, dibenzoyl peroxide, 2-butanone peroxide, tert-butyl perbenzoate, di-tert-butyl peroxide, 2,5-dimethyl-2,5-di. Examples thereof include (t-butylperoxy) hexane, bis (tert-butylperoxyisopropyl) benzene and tert-butylhydroperoxide. Examples of the azo compound include 2,2'-azobis (2-methylpropanenitrile), 2,2'-azobis (2-methylbutanenitrile) and 1,1'-azobis (cyclohexanecarbonitrile).

(Inorganic filler)
The resin film according to this embodiment may further contain an inorganic filler. By optionally containing an appropriate inorganic filler, the low thermal expansion property, high elastic modulus, heat resistance, flame retardancy and the like of the resin composition can be improved. The inorganic filler is not particularly limited, but for example, silica, alumina, titanium oxide, mica, beryllium, barium titanate, potassium titanate, strontium titanate, calcium titanate, aluminum carbonate, magnesium hydroxide, aluminum hydroxide, etc. Examples thereof include aluminum silicate, calcium carbonate, calcium silicate, magnesium silicate, silicon nitride, boron nitride, calcined clay, talc, aluminum borate, and silicon carbide. These may be used alone or in combination of two or more.

There are no particular restrictions on the shape and particle size of the inorganic filler. The shape of the inorganic filler may be, for example, spherical or crushed. The particle size of the inorganic filler may be, for example, 0.01 to 50 μm, 0.01 to 20 μm, 0.1 to 15 μm, or 0.1 to 10 μm. Here, the particle size refers to the average particle size, and is the particle size of a point corresponding to a volume of 50% when the cumulative frequency distribution curve based on the particle size is obtained with the total volume of the particles as 100%. The average particle size can be measured with a particle size distribution measuring device or the like using a laser diffraction / scattering method.

The mixing ratio of the inorganic filler to the resin film is not particularly limited, but since the adhesiveness, toughness, heat resistance, chemical resistance, etc. of the resin film tend to be particularly improved, for example, the total amount of the resin components is 100 mass. It can be 1 to 1000 parts by mass with respect to the portion, and can be 1 to 800 parts by mass from the viewpoint of suppressing thermal expansion of the resin film.

When an inorganic filler is used, the amount used is not particularly limited, but for example, the content ratio of the inorganic filler is preferably 3 to 75% by volume, with the solid content in the resin composition as the total amount, and 5 to 70 volumes. More preferably. When the content ratio of the inorganic filler in the resin composition is within the above range, good curability, moldability and chemical resistance can be easily obtained.

(Thermosetting resin)
The resin film according to the present embodiment can further contain a thermosetting resin different from the component (A) and the component (B). The compound (A) or the compound that can correspond to the component (B) shall not belong to the (C) thermosetting resin. Examples of the thermosetting resin (C) include an epoxy resin and a cyanate ester resin. By including the thermosetting resin (C), the low thermal expansion characteristics of the resin film can be further improved.

(C) When the epoxy resin is contained as the thermosetting resin, it is not particularly limited, but for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, alicyclic epoxy resin, aliphatic chain type. Naphthalene skeleton-containing epoxy resin such as epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, phenol aralkyl type epoxy resin, naphthol novolac type epoxy resin, naphthol aralkyl type epoxy resin, etc. Examples thereof include a biphenyl type epoxy resin, a biphenyl aralkyl type epoxy resin, a dicyclopentadiene type epoxy resin, and a dihydroanthracene type epoxy resin. These may be used alone or in combination of two or more. Among these, from the viewpoint of high frequency characteristics and thermal expansion characteristics, it is preferable to use a naphthalene skeleton-containing epoxy resin or a biphenyl aralkyl type epoxy resin.

(C) When the cyanate ester resin is contained as the thermosetting resin, it is not particularly limited, but for example, 2,2-bis (4-cyanatophenyl) propane, bis (4-cyanatophenyl) ethane, and bis (3). , 5-Dimethyl-4-cyanatophenyl) methane, 2,2-bis (4-cyanatophenyl) -1,1,1,3,3,3-hexafluoropropane, α, α'-bis (4) -Cyanatophenyl) -m-diisopropylbenzene, cyanate ester compound of phenol-added dicyclopentadiene polymer, phenol novolac type cyanate ester compound, cresol novolac type cyanate ester compound and the like. These may be used alone or in combination of two or more. Among these, 2,2-bis (4-cyanatophenyl) propane is preferably used in consideration of its low cost and the total balance of high frequency characteristics and other characteristics.

(Hardener)
The resin film according to this embodiment may further contain a curing agent of (C) a thermosetting resin. As a result, the reaction when obtaining the cured product of the resin film can be smoothly promoted, and the physical properties of the cured product of the obtained resin film can be appropriately adjusted.

When an epoxy resin is used, the curing agent is not particularly limited, but for example, polyamine compounds such as diethylenetriamine, triethylenetetramine, diaminodiphenylmethane, m-phenylenediamine, and dicyandiamide; bisphenol A, phenol novolac resin, cresol novolac resin, and bisphenol A. Polyphenol compounds such as novolak resin and phenol aralkyl resin; acid anhydrides such as phthalic anhydride and pyromellitic anhydride; various carboxylic acid compounds; various active ester compounds and the like can be mentioned.

When the cyanate ester resin is used, the curing agent is not particularly limited, and examples thereof include various monophenol compounds, various polyphenol compounds, various amine compounds, various alcohol compounds, various acid anhydrides, and various carboxylic acid compounds. These may be used alone or in combination of two or more.

(Curing accelerator)
The resin film according to the present embodiment may further contain a curing accelerator depending on the type of (C) thermosetting resin. The curing accelerator for epoxy resins, for example, various imidazoles a latent heat curing agent, BF ₃ amine complexes, phosphorus-based curing accelerator, and the like. When a curing accelerator is blended, imidazoles and phosphorus-based curing accelerators are preferable from the viewpoints of storage stability of the resin composition, handleability of the semi-cured resin composition, and solder heat resistance.

(Thermoplastic resin)
The resin film according to the present embodiment may further contain a thermoplastic resin from the viewpoint of improving the handleability of the resin film. The type of the thermoplastic resin is not particularly limited, and the molecular weight is not particularly limited, but the number average molecular weight (Mn) is preferably 200 to 60,000 from the viewpoint of further enhancing the compatibility with the component (A).

From the viewpoint of film formability and moisture absorption resistance, the thermoplastic resin is preferably a thermoplastic elastomer. Examples of the thermoplastic elastomer include saturated thermoplastic elastomers, and examples of saturated thermoplastic elastomers include chemically modified saturated thermoplastic elastomers and non-modified saturated thermoplastic elastomers. Examples of the chemically modified saturated thermoplastic elastomer include a styrene-ethylene-butylene copolymer modified with maleic anhydride. Specific examples of the chemically modified saturated thermoplastic elastomer include Tough Tech M1911, M1913, M1943 (all manufactured by Asahi Kasei Chemicals Co., Ltd., trade name) and the like. On the other hand, examples of the non-modified saturated thermoplastic elastomer include a non-modified styrene-ethylene-butylene copolymer and the like. Specific examples of the non-denatured saturated thermoplastic elastomer include Tough Tech H1041, H1051, H1043, H1053 (all manufactured by Asahi Kasei Chemicals Co., Ltd., trade name) and the like.

From the viewpoint of film formability, dielectric properties and moisture absorption resistance, the saturated thermoplastic elastomer preferably has a styrene unit in the molecule. In the present specification, the styrene unit refers to a unit derived from the styrene monomer in the polymer, and the saturated thermoplastic elastoma is an aliphatic hydrocarbon portion other than the aromatic hydrocarbon portion of the styrene unit. However, all of them have a structure composed of saturated bond groups.

The content ratio of the styrene unit in the saturated thermoplastic elastomer is not particularly limited, but the mass percentage of the styrene unit to the total mass of the saturated thermoplastic elastomer is preferably 10 to 80% by mass, preferably 20 to 70% by mass. It is more preferable to have it. When the content ratio of the styrene unit is within the above range, the film appearance, heat resistance and adhesiveness tend to be excellent.

Specific examples of the saturated thermoplastic elastomer having a styrene unit in the molecule include a styrene-ethylene-butylene copolymer. The styrene-ethylene-butylene copolymer can be obtained, for example, by hydrogenating the unsaturated double bond of the butadiene-derived structural unit of the styrene-butadiene copolymer.

The content of the thermoplastic resin is not particularly limited, but from the viewpoint of further improving the dielectric properties, the total solid content of the resin composition is preferably 0.1 to 15% by mass, preferably 0.3 to 10% by mass. It is more preferably%, and further preferably 0.5 to 5% by mass.

[Manufacturing method of resin film]
(Preparation of resin composition and resin varnish)
Next, a preferable example of a method for manufacturing a resin film for manufacturing a high-multilayer printed wiring board will be described. The method for preparing the resin composition for forming the resin film according to the present embodiment is not particularly limited, and examples thereof include the following methods.

The resin composition according to the present embodiment can be obtained by uniformly dispersing and mixing each of the above-mentioned components, and the preparation means, conditions and the like thereof are not particularly limited. For example, after sufficiently uniformly stirring and mixing various components in a predetermined blending amount with a mixer or the like, kneading is performed using a mixing roll, an extruder, a kneader, a roll, an extruder or the like, and the obtained kneaded product is further cooled and mixed. A method of crushing can be mentioned. The kneading format is also not particularly limited. The resin composition may contain an organic solvent, if necessary, and the above components may be in the form of a resin varnish dissolved or dispersed in the organic solvent.

The organic solvent is not particularly limited, and for example, alcohols such as methanol, ethanol and butanol, ethers such as ethyl cellosolve, butyl cellosolve, ethylene glycol monomethyl ether, carbitol and butyl carbitol; acetone, methyl ethyl ketone and methyl isobutyl ketone. , Cyclohexanone and other ketones; Aromatic hydrocarbons such as toluene, xylene, mesitylene; esters such as methoxyethyl acetate, ethoxyethyl acetate, butoxyethyl acetate, ethyl acetate; N, N-dimethylformamide, N, N- Examples thereof include nitrogen-containing substances such as dimethylacetamide and N-methyl-2-pyrrolidone. In particular, aromatic hydrocarbons such as toluene, xylene, and mesitylene, which are good solvents for the component (A), and a mixed solvent of these aromatic hydrocarbons and ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone, and cyclohexanone. However, it is preferable because the appearance of the film is good. One type of these solvents may be used alone, or two or more types may be used in combination.

When the resin film contains an inorganic filler, it is preferable to prepare a slurry by dispersing the inorganic filler in an organic solvent from the viewpoint of improving the dispersibility of the inorganic filler in the resin varnish. When a thermoplastic resin is used in combination, a resin varnish is produced by adding the above-mentioned thermoplastic resin to this slurry to dissolve or uniformly disperse it, and then adding a thermosetting component such as component (A). Is preferable.

When the resin composition is used as a varnish, it is preferable to adjust the amount of the solvent used so that the solid content (nonvolatile content) concentration in the varnish is 5 to 80% by mass. In the step of producing the resin film described later, the amount of the solvent can be adjusted by evaporating the solvent after applying the resin composition. In this case, the resin varnish can be prepared to have a solid content (nonvolatile content) concentration and varnish viscosity so as to obtain a good appearance and a desired film thickness.

[Resin film with support]
In the present embodiment, a resin film can be produced by using the above resin composition. The resin film refers to an uncured or semi-cured film-like resin composition.

The method for producing the resin film is not limited, but it can be obtained, for example, by applying the resin composition on the supporting base material and drying the formed resin layer. A resin film can be produced by a known method using the resin composition as described above. Specifically, after applying the above resin composition on a supporting substrate using a kiss coater, a roll coater, a comma coater or the like, the temperature is, for example, 70 to 250 ° C., preferably 70 to 200 ° C. in a heating / drying furnace or the like. Then, it may be dried for 1 to 30 minutes, preferably 3 to 15 minutes. As a result, a resin film in which the resin composition is semi-cured can be obtained.

The semi-cured resin film can be further thermoset by heating it in a heating furnace at a temperature of, for example, 170 to 250 ° C., preferably 185 to 230 ° C. for 60 to 150 minutes. it can.

The thickness of the resin film according to the present embodiment is not particularly limited, but is preferably 1 to 200 μm, more preferably 2 to 180 μm, and even more preferably 3 to 150 μm. By setting the thickness of the resin film within the above range, it is easy to achieve both thinning of the high-multilayer printed wiring board obtained by using the resin film according to the present embodiment and good high-frequency characteristics, and insulation with high film thickness accuracy. Layers can be formed.

The supporting base material is not particularly limited, but is preferably at least one selected from the group consisting of a heat-resistant film such as a PET film and a metal foil. Since the resin film is provided with the supporting base material, the storage property and the handleability when used in the production of the printed wiring board tend to be improved. That is, the resin film according to the present embodiment can take the form of a resin film with a support having the resin film and the support base material, and may be peeled off from the support base material when used.

[Prepreg]
From the viewpoint of strength and handleability, the resin film and the sheet-shaped fiber reinforced base material according to the present embodiment can be laminated and used as a prepreg for a high-multilayer printed wiring board. That is, the prepreg according to the present embodiment has a resin film and a sheet-shaped fiber reinforced base material.

As the sheet-shaped fiber reinforced base material, for example, known materials used for various laminated boards for electrical insulating materials are used. Examples of the material include inorganic fibers such as E glass, NE glass, S glass and Q glass; organic fibers such as aromatic polyamide, polyimide, aromatic polyester and tetrafluoroethylene; carbon fibers and the like. The sheet-shaped fiber reinforced base material may be a unidirectionally arranged fiber sheet or a randomly arranged non-woven fabric sheet of these fibers. From the viewpoint of handleability, a glass cloth can be used, and the glass cloth is not particularly limited, but one in which yarn is knitted at high density or one in which opened fiber yarn (spread fiber yarn) is used can be used. As the sheet-shaped fiber reinforced base material, those having a shape such as a woven fabric, a non-woven fabric, or a chopped strand mat can be used. Further, the thickness of the sheet-shaped fiber base material is not particularly limited, and for example, one having a thickness of 0.02 to 0.5 mm can be used. Further, as the sheet-shaped fiber reinforced base material, one that has been surface-treated with a coupling agent or the like, or one that has been mechanically opened, has the impregnation property of the resin composition and the heat resistance when made into a laminated board. , Preferable from the viewpoint of moisture absorption resistance and processability.

When a sheet-shaped fiber reinforced base material is used, the prepreg for a high-multilayer printed wiring board is, for example, a method of impregnating a glass cloth with a resin varnish obtained by dissolving or dispersing a resin composition in an organic solvent. Can also be obtained by. The method of impregnating the glass cloth with the resin varnish is not particularly limited, but for example, a method of immersing the glass cloth in the resin varnish, a method of applying the resin varnish to the glass cloth by various coaters, and a method of spraying the resin varnish into the glass cloth. Examples include the method of spraying. Among these, a method of immersing the glass cloth in the resin varnish can be used from the viewpoint of improving the impregnation property of the resin varnish.

[Metal-clad laminate]
Using the above resin film, a metal tension cured resin film for high multilayer can be manufactured. That is, according to the present embodiment, it is possible to provide a high-multilayer metal-clad laminate having a resin layer containing a cured product of the resin film described above and a conductor layer. For example, the resin film or the resin film with a support can be used to manufacture a metal-clad laminate for high multilayer.

The method for producing the metal-clad laminate is not limited, but for example, one or a plurality of resin films according to the present embodiment are laminated, and a metal foil to be a conductor layer is arranged on at least one surface, for example, 170 to 250 ° C. A metal foil is formed on at least one surface (both sides or one side) of the resin layer to be an insulating layer by heating and pressurizing at a temperature of 185 to 230 ° C. and a pressure of 0.5 to 5.0 MPa for 60 to 150 minutes. A metal-clad laminate is obtained. The heating and pressurization can be performed, for example, under the conditions of a vacuum degree of 10 kPa or less, preferably 5 kPa or less, and is preferably performed in a vacuum from the viewpoint of improving efficiency. The heating and pressurization are preferably carried out from the start for 30 minutes to the end time of molding.

[Manufacturing of multi-layer printed wiring board]
The resin film can also be used for manufacturing a multilayer printed wiring board such as a build-up wiring board. That is, according to the present embodiment, it is possible to provide a high-multilayer printed wiring board including a resin layer containing a cured product of the above-mentioned resin film and a circuit layer. The upper limit of the number of circuit layers is not particularly limited, and may be 3 to 80 layers or 6 to 50 layers. The high-multilayer printed wiring board can also be manufactured by using, for example, the above-mentioned resin film, resin film with a support, or metal-clad laminate.

The method for manufacturing the high-multilayer printed wiring board is not particularly limited. For example, first, a resin film is arranged on one side or both sides of the circuit-formed core substrate, or a resin film is formed between a plurality of core substrates. After arranging and bonding each layer by pressurizing and heat laminating molding or pressurizing and heating press molding, perform circuit forming processing by laser drilling, drilling, metal plating, metal etching, etc. As a result, a multilayer printed wiring board can be manufactured. When the resin film has a support base material (when a resin film with a support is used), the support base material is peeled off before placing the resin film on or between the core substrates, or , The resin layer can be peeled off after being attached to the core substrate.

A method for manufacturing a high-multilayer printed wiring board using the resin film according to the present embodiment will be described with reference to FIG. FIG. 1 is a diagram schematically showing a manufacturing process of a high-multilayer printed wiring board according to the present embodiment. The method for manufacturing a multilayer printed wiring board according to the present embodiment includes (a) a step of laminating a resin film on an inner layer circuit board to form a resin layer (hereinafter referred to as "step (a)") and (b) a resin. A step of heating and pressurizing the layer to cure it (hereinafter referred to as "step (b)") and (c) a step of forming an antenna circuit layer on the cured resin layer (hereinafter referred to as "step (c)"). And have.

As shown in FIG. 1A, in the step (a), the resin film 12 according to the present embodiment is laminated on the inner layer circuit board 11 to form a resin layer made of the resin film 12.

The laminating method is not particularly limited, and examples thereof include a method of laminating using a multi-stage press, a vacuum press, a normal pressure laminator, and a laminator that heats and pressurizes under vacuum, and a method that uses a laminator that heats and pressurizes under vacuum is preferable. .. As a result, even if the inner layer circuit board 11 has a fine wiring circuit on the surface, there are no voids and the circuits can be embedded with resin. The laminating conditions are not particularly limited, but it is preferable that the crimping temperature is 70 to 130 ° C. and the crimping pressure is 1 to 11 kgf / cm ² , and laminating is performed under reduced pressure or vacuum. The laminating may be a batch type or a continuous type in a roll.

The inner layer circuit board 11 is not particularly limited, and a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a heat-curable polyphenylene ether substrate, or the like can be used. The circuit surface of the surface on which the resin film of the inner layer circuit board 11 is laminated may be roughened in advance.

The number of circuit layers of the inner layer circuit board 11 is not limited. In FIG. 1, a 6-layer inner-layer circuit board is used, but the number of layers is not limited to this. For example, when a high-multilayer printed wiring board for a millimeter-wave radar is manufactured, 2 to 80 layers or the like may be used depending on the design. You can choose freely. The high-multilayer printed wiring board of this embodiment can be applied to the fabrication of a millimeter-wave radar. That is, it is possible to manufacture a high-multilayer printed wiring board for a millimeter-wave radar, which includes a resin layer containing a cured product of the resin film of the present embodiment and a circuit layer.

When the antenna circuit layer 14 described later is formed on the resin layer 12a by etching, the metal foil 13 may be further laminated on the resin film 12 to form the metal layer 13a. Examples of the metal foil include copper, aluminum, nickel, zinc and the like, and copper is preferable from the viewpoint of conductivity. The metal foil may be an alloy, and examples of the copper alloy include high-purity copper alloys to which a small amount of beryllium or cadmium is added. The thickness of the metal foil is preferably 3 to 200 μm, more preferably 5 to 70 μm.

As shown in FIG. 1B, in the step (b), the inner layer circuit board 11 and the resin layer 12a laminated in the step (a) are heated and pressed to be thermoset. The conditions are not particularly limited, but the temperature is preferably in the range of 100 ° C. to 250 ° C., the pressure is 0.2 to 10 MPa, and the time is 30 to 120 minutes, and more preferably 150 ° C. to 220 ° C.

As shown in FIG. 1 (c), in the step (c), the antenna circuit layer 14 is formed on the resin layer 12a. The method for forming the antenna circuit layer 14 is not particularly limited, and for example, the antenna circuit layer 14 may be formed by an etching method such as a subtractive method, a semi-additive method, or the like.

In the subtractive method, an etching resist layer having a shape corresponding to a desired pattern shape is formed on the metal layer 13a, and the metal layer of the portion from which the resist has been removed is dissolved and removed with a chemical solution by a subsequent development process. This is a method of forming a desired circuit. As the chemical solution, for example, a copper chloride solution, an iron chloride solution or the like can be used.

In the semi-additive method, a metal film is formed on the surface of the resin layer 12a by an electroless plating method, a plating resist layer having a shape corresponding to a desired pattern is formed on the metal film, and then the metal layer is formed by an electroplating method. This is a method of forming a desired circuit layer by removing an unnecessary electroless plating layer with a chemical solution or the like after the formation.

Further, holes such as via holes 15 may be formed in the resin layer 12a, if necessary. The method of forming holes is not limited, but NC drills, carbon dioxide lasers, UV lasers, YAG lasers, plasmas and the like can be applied.

Here, the inner layer circuit board 11 can also be manufactured by the steps (p) to (r) shown in FIG. FIG. 2 is a diagram schematically showing a manufacturing process of an inner layer circuit board. That is, the method for manufacturing a multilayer printed wiring board according to the present embodiment includes steps (p), steps (q), steps (r), steps (a), steps (b), and steps (c). May be good. Hereinafter, steps (p) to (r) will be described.

First, as shown in FIG. 2 (p), the core substrate 41 and the prepreg 42 are laminated in the step (p). As the core substrate, for example, a glass epoxy substrate, a metal substrate, a polyester substrate, a polyimide substrate, a BT resin substrate, a thermosetting polyphenylene ether substrate, or the like can be used. Examples of the prepreg include "GWA-900G", "GWA-910G", "GHA-679G", "GHA-679G (S)", "GZA-71G" and "GEA-75G" manufactured by Hitachi Chemical Company, Ltd. Product name) etc. can be used.

Next, as shown in FIG. 2 (q), in the step (q), the laminate of the core substrate 41 and the prepreg 42 obtained in the step (p) is heated and pressed. The heating temperature is not particularly limited, but is preferably 120 to 230 ° C, more preferably 150 to 210 ° C. The pressure to pressurize is not particularly limited, but is preferably 1 to 5 MPa, more preferably 2 to 4 MPa. The heating time is not particularly limited, but is preferably 30 to 120 minutes. As a result, it is possible to obtain an inner layer circuit board having excellent dielectric properties, mechanical and electrical connection reliability at high temperature and high humidity.

Further, as shown in FIG. 2 (r), in the step (r), a through hole 43 is formed in the inner layer circuit board as needed. The method for forming the through hole 43 is not particularly limited, and may be the same as the step for forming the antenna circuit layer described above, or a known method may be used.

By the above steps, the high-multilayer printed wiring board of the present embodiment can be manufactured. Further, the steps (a) to (c) may be further repeated using the printed wiring board manufactured through the above steps as an inner layer circuit board.

FIG. 3 is a diagram schematically showing a manufacturing process of a multilayer printed wiring board using the multilayer printed wiring board manufactured by the process shown in FIG. 1 as an inner layer circuit board. (A) and FIG. 1 (a) correspond to FIG. 3 (b) and FIG. 1 (b), and FIG. 3 (c) and FIG. 1 (c) correspond to each other.

Specifically, in FIG. 3A, the resin film 22 is laminated on the inner layer circuit board 21 to form the resin layer 22s, and the metal foil 23 is laminated on the resin film 22 as needed to form the metal layer 23a. Is the process of forming. FIG. 3B is a step of heating and pressurizing the resin layer 22a to cure the resin layer 22a, and FIG. 3C is a step of forming the antenna circuit layer 24 on the cured resin layer.

In FIGS. 1 and 3, the number of resin layers laminated on the inner circuit board is set to one or two for the purpose of forming an antenna circuit pattern or the like, but the number is not limited to this, depending on the antenna circuit design. The number of layers may be three or more. By making the antenna circuit layer multi-layered, it becomes easy to design an antenna having a wide band characteristic and an antenna in which the angle change of the antenna radiation pattern is small (beam tiltless) in the frequency band used.

The resin film according to this embodiment can be suitably used for manufacturing a high-multilayer printed wiring board. In the method for producing a high multilayer printed wiring board according to the present embodiment, a resin film containing a maleimide group, a divalent group having at least two imide bonds, and a compound having a saturated or unsaturated divalent hydrocarbon group is used. Since the resin layer is formed by using the resin layer, a laminated body can be produced without providing an adhesive layer in addition to the layer having excellent high frequency characteristics. As a result, the effect of simplifying the process and further improving the high frequency characteristics can be obtained.

Although the preferred embodiments of the present invention have been described above, these are examples for explaining the present invention, and the scope of the present invention is not limited to these embodiments. The present invention can be carried out in various aspects different from the above embodiments without departing from the gist thereof.

Hereinafter, the present invention will be described in more detail based on Examples and Comparative Examples. However, the present invention is not limited to the following examples.

[Preparation of resin varnish]
Various resin varnishes were prepared according to the following procedure. The amounts (parts by mass) of the raw materials used for preparing the resin varnishes of Preparation Examples 1 to 8 and Comparative Preparation Examples 1 to 4 are summarized in Tables 1 and 2.

Each component shown in Table 1 or Table 2 is placed in a 300 mL four-necked flask equipped with a thermometer, a reflux condenser and a stirrer, and after stirring at 25 ° C. for 1 hour, # 200 nylon mesh (opening 75 μm). To prepare a resin flask.

The abbreviations and the like of each material in Tables 1 and 2 are as follows.
((1) BMI-1500 [Mw: about 1500, manufactured by Designer Moleculars Inc., trade name]
(2) BMI-1700 [Mw: Approximately 1700, Designer Moleculars Inc. Made, product name]
(3) BMI-3000 [Mw: Approximately 3000, Designer Moleculars Inc. Made, product name]
(4) BMI-5000 [Mw: Approximately 5000, Designer Moleculars Inc. Made, product name]
(5) BMI-1000 [bis (4-maleimidephenyl] methane, manufactured by Daiwa Kasei Kogyo Co., Ltd., trade name)
(6) BMI-4000 [2,2-bis (4- (4-maleimide phenoxy) phenyl) propane, manufactured by Daiwa Kasei Kogyo Co., Ltd., trade name]
(7) B-3000 [Butadiene homopolymer, Mn: about 3000, manufactured by Nippon Soda Co., Ltd., trade name]
(8) PPO640 [Polyphenylene ether, Mn: Approximately 16000, manufactured by SABIC Innovative Plastics, trade name]
(9) NC-3000H [Biphenyl aralkyl type epoxy resin, manufactured by Nippon Kayaku Co., Ltd., trade name]
(10) BADCY [2,2-bis (4-cyanatophenyl) propane, manufactured by Lonza, trade name]
(11) KA1165 [Novolak type phenolic resin, manufactured by DIC Corporation, trade name],
(12) PCP [p-cumylphenol, manufactured by Wako Pure Chemical Industries, Ltd., trade name],
(13) H1041 [Hydrogenated styrene-butadiene copolymer of less than Mn 60,000, styrene content ratio: 30%, Mn: 58000, manufactured by Asahi Kasei Chemicals Co., Ltd., trade name "Tough Tech H1041"]
(14) Silica slurry [Spherical molten silica, surface treatment: phenylaminosilane coupling agent (1% by mass / total solid content in the slurry), dispersion medium: methyl isobutyl ketone (MIBK), solid content concentration: 70% by mass, average Particle size: 0.5 μm, density: 2.2 g / cm ³ , manufactured by Admatex Co., Ltd., trade name "SC-2050KNK"]
(15) Perhexine 25B [2,5-dimethyl-2,5-di (t-butylperoxy) hexane, manufactured by NOF CORPORATION, trade name]
(16) 2E4MZ [2-ethyl-4methyl-imidazole, manufactured by Shikoku Chemicals Corporation, trade name]
(17) Zinc naphthenate [manufactured by Tokyo Chemical Industry Co., Ltd.]

[Preparation of resin film]
Using a comma coater, the resin varnishes obtained in Preparation Examples 1 to 8 and Comparative Preparation Examples 1 to 4 were used as a supporting base material for a 38 μm-thick PET film (trade name “G2-38”, manufactured by Teijin Co., Ltd.). A resin film with a PET film having a semi-cured resin layer having a thickness of 50 μm was prepared by coating on the top (drying temperature: 130 ° C.). The semi-curable resin films prepared using the resin varnishes of Preparation Examples 1 to 8 are Examples 1 to 8, and the semi-curable resin films prepared using the resin varnishes of Comparative Preparation Examples 1 to 4 are Comparative Examples 1 to 4. Corresponds to each.

[Evaluation of resin film]
The appearance and handleability of the semi-cured resin films of Examples 1 to 8 and Comparative Examples 1 to 4 were evaluated. The evaluation results are shown in Table 3.

The appearance was visually evaluated, and those having some unevenness, streaks, etc. on the surface of the resin film and lacking surface smoothness were marked with x, and those without unevenness, streaks, etc. were marked with ◯. In terms of handleability, those having a slight stickiness (tack) on the surface at 25 ° C. or those having resin cracking or powder falling even when cut with a cutter knife were evaluated as x, and those other than that were evaluated as ◯.
[High multi-layer printed wiring board]
A glass cloth base material epoxy resin copper-clad laminate on which a circuit pattern is formed is used as an inner layer circuit board, and one of the above resin films from which the PET film has been peeled off is placed on both sides of the inner layer circuit board, and an electrolytic copper foil having a thickness of 12 μm is placed therein. After arranging (trade name "YGP-12", manufactured by Nippon Denshi), a mirror plate is placed on it, and heat and pressure molding is performed under press conditions of 200 ° C./3.0 MPa/70 minutes, and four layers for evaluation are used. A printed wiring board was produced.

Next, the copper foil of the outermost layer of the produced four-layer printed wiring board was etched, and the circuit embedding property (multilayer formability) was evaluated. The multi-layer moldability was visually evaluated, and those having some voids and blurring were evaluated as x, and those having a uniform resin filling in the circuit were evaluated as ◯.

[Double-sided metal-clad cured resin film]
Two resin films obtained by peeling the PET film from the above-mentioned resin film with PET film are stacked, and low profile copper foil with a thickness of 18 μm (M surface Rz: 3 μm, trade name “F3-WS”, Furukawa Denki Kogyo) is placed on both sides thereof. (Made by Co., Ltd.) is placed so that its roughened surface (M surface) is in contact, a mirror plate is placed on it, and heat and pressure molding is performed under pressing conditions of 200 ° C./3.0 MPa/70 minutes, and double-sided metal covering A cured resin film (thickness: 0.1 mm) was prepared.

Regarding the double-sided metal-clad cured resin films of Examples 1 to 8 and Comparative Examples 1 to 4 described above, handleability (bending resistance), dielectric properties, copper foil peeling strength, solder heat resistance, water absorption rate and insulation reliability. Gender was evaluated. The evaluation results are shown in Table 3. The method for evaluating the characteristics of the double-sided metal-clad cured resin film is as follows.

[Bending resistance]
The bending resistance was evaluated by bending an etched outer layer copper foil of a double-sided metal-clad cured resin film by 180 degrees. Those in which some cracks or cracks were generated when bent were evaluated as x, and those in which there was no change when the bending was stopped were evaluated as ◯.

[Dielectric property]
The relative permittivity and dielectric loss tangent, which are the dielectric properties, are obtained by etching the outer layer copper foil of a double-sided metal-clad cured resin film and cutting it into a length of 60 mm, a width of 2 mm, and a thickness of about 1 mm as a test piece by the cavity resonator perturbation method. It was measured. Vector network analyzer E8364B manufactured by Agilent Technologies, CP129 (10 GHz band resonator) and CP137 (20 GHz band resonator) manufactured by Kanto Denshi Applied Development Co., Ltd. for the cavity resonator, and CPMA-V2 for the measurement program. I used each. The conditions were frequencies of 10 GHz and 20 GHz and a measurement temperature of 25 ° C.

[Measurement of copper foil peeling strength]
The copper foil peeling strength of the double-sided metal-clad cured resin film was measured in accordance with the copper-clad laminate test standard JIS-C-6481. The measurement temperature was 25 ° C.

[Solder heat resistance]
For solder heat resistance, a copper foil on one side of a double-sided metal-clad cured resin film is etched and cut into 50 mm squares as a test piece, and the normal condition and pressure cooker test (PCT) device (condition: 121 ° C., 2.2) After being treated for a predetermined time (1, 3, 5 hours) at (pressure), the film is floated on molten solder at 288 ° C. for 20 seconds, and the appearance of each of the three cured resin films having different treatment times is visually observed. Examined. The case where no swelling or measling was observed inside the film or between the film and the copper foil was evaluated as ◯, and the case where the inside of the film and between the film and the copper foil was observed was evaluated as x.

[Water absorption rate]
The water absorption rate is determined by etching the copper foil on both sides of the double-sided metal-clad cured resin film and cutting it into 50 mm squares as a test piece, and using the normal condition and pressure cooker test (PCT) device (condition: 121 ° C, 2.2 atm). ) Was treated for a predetermined time (5 hours) and then calculated from the mass difference.

As is clear from the results shown in Table 3, according to the resin films of Examples 1 to 8, the appearance (surface uniformity) and the handleability (tackiness) are as compared with the resin films of Comparative Examples 1 to 4. It was confirmed that there was no problem with cracking, powder falling, etc.) and the multi-layer moldability was also good.

Further, the cured resin films obtained by curing the resin films of Examples 1 to 8 are excellent in relative permittivity of 3.0 or less and dielectric loss tangent of 0.003 or less, and have excellent solder heat resistance, copper foil peeling strength and The water absorption rate also satisfied the practical characteristics.

On the other hand, in Comparative Examples 1 to 4, there is a problem in appearance or handleability, and as compared with Examples, dielectric characteristics, solder heat resistance, copper foil peeling strength, water absorption rate, frequency drift property of dielectric characteristics, etc. Was shown to be relatively inferior.

[High-multilayer printed wiring board for millimeter-wave radar]
(Example 1)
After the inner layer circuit board 11 is manufactured in the step shown in FIG. 2, the height for a millimeter wave radar having a total of 7 layers including one millimeter wave antenna circuit layer in the step shown in FIG. 1 using the resin film of Example 1 A multi-layer printed wiring board was produced.

First, in the step (p), a glass cloth base material epoxy copper-clad laminate with a thickness of 0.1 mm (manufactured by Hitachi Kasei Co., Ltd., trade name "MCL-E-75G") in which copper foils with a thickness of 18 μm are bonded on both sides. After etching and removing unnecessary copper foil to prepare an inner layer circuit board, a 0.1 mm glass cloth base epoxy prepreg (manufactured by Hitachi Kasei Co., Ltd., trade name "GEA-75G") is coated with a copper-clad laminate. A structure was prepared by arranging them on top of each other. Next, in step (q), the structure produced in step (p) was heat-press molded under press conditions of 180 ° C./3.0 MPa/60 minutes to form an integrated substrate. Then, in the step (r), a hole was drilled at a desired position in the integrated substrate produced in the step (q), and copper plating was performed in the hole to prepare the inner layer circuit board 11.

In the step (a), a semi-cured resin film (thickness 130 μm) prepared by using the resin composition of Example 1 is temporarily adhered to the surface of the inner layer circuit board 11 with a vacuum laminator, and further, a low layer having a thickness of 18 μm is temporarily adhered. A profile copper foil (manufactured by Furukawa Denki Kogyo Co., Ltd., trade name "F3-WS") was placed to prepare a structure. Next, in the step (b), a mirror plate was placed on the structure produced in the step (a), and heat and pressure molding was performed under press conditions of 200 ° C./3.0 MPa/70 minutes. Then, in step (c), the structure produced in step (b) is plated and etched after removing unnecessary resin and forming via holes (IVH) at desired positions with a laser. The antenna circuit layer 14 was formed, and a high-layer printed wiring board having a total of 7 layers including one millimeter-wave antenna circuit layer was obtained.

(Example 2)
Using the resin film of Example 2, a high-multilayer printed wiring board for a millimeter-wave radar having a total of eight layers including two millimeter-wave antenna circuit layers was produced in the process shown in FIG.

In the step (a), the high-multilayer printed wiring board for millimeter-wave radar produced in Example 1 is used as the inner layer circuit board 21, and the semi-cured resin film produced by using the resin composition of Example 2 on the surface thereof. (Thickness 130 μm) was temporarily bonded with a vacuum laminator, and then “F3-WS” was placed to prepare a structure. Next, in the step (b), a mirror plate was placed on the structure produced in the step (a), and heat and pressure molding was performed under press conditions of 200 ° C./3.0 MPa/70 minutes. Then, in step (c), the structure produced in step (b) is plated and etched after removing unnecessary resin and forming via holes (IVH) at desired positions with a laser. The antenna circuit layer 24 was formed, and a high-multilayer printed wiring board for a millimeter-wave radar having a total of eight layers including two layers of millimeter-wave antenna circuits was obtained.

(Comparative Example 5)
High-multilayer printing for millimeter-wave radar with a total of eight layers including two millimeter-wave antenna circuit layers in the process shown in FIG. 4, which is a conventional method, using a fluororesin material instead of the resin film of Example 2. A wiring board was produced.

First, in the step (a') of FIG. 4, 0.1 mm glass cloth base material epoxy prepreg (GEA-75G) 33 and 0. are placed on the inner layer circuit board 31 produced in the above steps (p) to (r). A structure was produced by stacking and arranging copper-clad laminates 32 from which unnecessary copper foil of a 13 mm fluororesin-based copper-clad laminate (manufactured by Rogers Corporation, trade name "RO-3003") was removed by etching. Next, in step (b'), the structure produced in step (a') was heat-press molded under press conditions of 180 ° C./3.0 MPa/60 minutes, and a total of 7 including one layer of the antenna circuit was formed. A multi-layer wiring board with a layer structure was produced. Next, in the step (c'), a 0.1 mm glass cloth base material epoxy prepreg (GEA-75G) 33 and a 0.13 mm fluororesin group were placed on the multilayer wiring board produced in the step (b'). A structure was produced by stacking and arranging copper-clad laminates 32 from which unnecessary copper foil of the copper-clad laminate (RO-3003) was removed by etching. Then, in the step (d'), the structure produced in the step (c') is heat-press molded under the press conditions of 180 ° C./3.0 MPa/60 minutes, and then through-hole drilling-plating-etching. A desired circuit was formed by the above method, and a high-multilayer printed wiring board for a millimeter-wave radar having a total of eight layers including two layers of antenna circuits was obtained.

According to the method of Comparative Example 5, an antenna circuit having a multi-layer structure can be formed by using a copper-clad laminate with a fluorine-based resin base material, but an adhesive layer such as a prepreg is required between the fluorine-based resins. At that time, since the adhesive layer such as a general prepreg has a poor relative permittivity and dielectric loss tangent in the millimeter wave band as compared with the fluororesin material, the presence of the adhesive layer between the fluororesins causes an antenna circuit having a multi-layer structure. The characteristics are easily deteriorated.

On the other hand, in the method of Example 2, since the antenna circuit having a multilayer structure is composed only of the material having excellent relative permittivity and dielectric loss tangent in the millimeter wave band, the characteristics are excellent as compared with Comparative Example 5. An antenna circuit having a multi-layer structure can be formed.

The resin film for manufacturing a high-multilayer printed wiring board of the present invention has a film forming ability and handleability suitable for manufacturing a build-up wiring board, and is at the same level as a fluororesin substrate material containing an inorganic filler. Since it has a specific dielectric constant of .0 or less, has a low dielectric loss tangent, and exhibits better dielectric properties than liquid crystal polymers, it exhibits transmission loss characteristics even in high frequency bands exceeding the millimeter wave band and is good. It has excellent low moisture absorption, solder heat resistance, and copper foil peeling strength. Therefore, members and parts of printed wiring boards used for mobile communication equipment that handles high-frequency signals of 1 GHz or higher, network-related electronic equipment such as base station equipment, servers, routers, and various electrical and electronic equipment such as large computers. It is useful as an application.

11,21,31 ... Inner layer circuit board, 12,22 ... Resin film, 12a, 22a ... Resin layer, 13,23 ... Metal foil, 13a, 23a ... Metal layer, 14,24 ... Antenna circuit layer, 15 ... Via hole, 32 ... Copper-clad laminate, 33, 42 ... Prepreg, 41 ... Core substrate, 43 ... Through hole.

Claims (9)

Maleimide group, a resin film of a high multi-layer printed wiring board prepared containing a compound having a divalent divalent hydrocarbon group group and saturated having at least two imide bond,
The divalent group having at least two imide bond is represented by the following formula (III), a group represented by (IV) or Formula (V), at the number of carbon atoms of the divalent hydrocarbon group of the saturated 8 ~ 100,
The content of the compound of the resin film is, Ri 10-90% by mass relative to the total weight of the resin film,
A resin film having a relative permittivity of 3.0 or less of a cured resin film obtained by curing the resin film.

Divalent hydrocarbon group of the saturated is a group represented by the following formula (II), the resin film according to claim 1.

[In formula (II), R ₂ and R ₃ each independently represent an alkylene group having _{4 to} 50 carbon atoms, R ₄ represents an alkyl group having _{4 to} 50 carbon atoms, and R ₅ has 2 to 50 carbon atoms. Indicates an alkyl group. ] The resin film according to claim 1 or 2, wherein the weight average molecular weight of the compound is 500 to 10000. The resin film according to any one of claims 1 to 3, further containing an inorganic filler. The resin film according to any one of claims 1 to 4, further containing a catalyst. A resin film with a support for manufacturing a high-multilayer printed wiring board, comprising the resin film according to any one of claims 1 to 5 and a support base material. A prepreg for manufacturing a high-multilayer printed wiring board, comprising the resin film according to any one of claims 1 to 5 and a sheet-shaped fiber reinforced base material. A high-multilayer metal-clad laminate having a resin layer containing a cured product of the resin film according to any one of claims 1 to 5 and a conductor layer. A high-multilayer printed wiring board comprising a resin layer containing a cured product of the resin film according to any one of claims 1 to 5 and a circuit layer.

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