JP2010199437A - Laminated board for printed wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminated board for a printed wiring board suitable for high-speed communication. <P>SOLUTION: The laminated board for the printed wiring board includes a reinforcing fiber base material formed of melting anisotropic polyester amide fiber which is composed of aromatic polyester amide in which a portion formed of a plurality of repetitive constitutive units is 90 mol% or more and each of the repetitive constitutive units has a molar ratio of 100:1-20:5-100:2-80:2-20, and which has a strength (T<SB>150</SB>) in a 150°C atmosphere being 17 cN/dtex or more and an elastic modulus (E<SB>150</SB>) in the 150°C atmosphere being 710 cN/dtex or more. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laminate for a printed wiring board produced by using a fiber base material such as a woven fabric, a nonwoven fabric, and paper useful for reinforcing an insulating resin layer of the printed wiring board, and in particular, a resin having a high processing temperature is used. The present invention relates to a laminate for a printed wiring board which can be manufactured with good productivity and workability sometimes and has low dielectric constant and low dielectric loss tangent characteristics.

  Conventionally, a laminated board for printed wiring boards has one or more prepreg sheets impregnated with an epoxy resin impregnated into a glass cloth substrate and laminated with copper foil, and heated with a hot plate press. It was manufactured through a process of pressing and integral molding.

  In recent years, a manufacturing technique of a multilayer printed wiring board by a build-up method that enables high-density wiring has been attracting attention. For example, a multilayer printed wiring in which a resin composition is applied to an inner layer circuit board on which a circuit is formed, heat-cured, a roughened surface is formed on the surface with a roughening agent, and a conductor layer is formed by plating. A method for manufacturing a plate has been proposed (see, for example, Patent Document 1 and Patent Document 2). In addition, an epoxy resin adhesive sheet is laminated to the inner layer circuit board on which the circuit is formed, heat-cured, a roughened surface is formed on the surface with a roughening agent, and a conductor layer is formed by plating. A method for manufacturing a wiring rod has also been proposed (see, for example, Patent Document 3). However, in any of the above methods, a material mainly composed of an epoxy resin is used, and at present, sufficient characteristics have not been obtained with respect to low dielectric constant, low dielectric loss tangent, and low water absorption. .

  On the other hand, in a conventional printed wiring board-related field, as a method for manufacturing a printed wiring board substrate having excellent dielectric characteristics, for example, a polytetrafluoroethylene (hereinafter referred to as PTFE) resin disperser is used for a base material made of glass cloth. John's impregnation and sintering treatment was repeated several times to produce a sheet made of glass fiber and PTFE, and then the sheet was laminated with a copper foil, and heat-pressed and integrated to produce a method ( Patent Document 4). When a plurality of the sheets are stacked to form a substrate, a tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer resin layer or a tetrafluoroethylene / hexafluoropropylene copolymer resin layer is interposed as a film between the sheets. Alternatively, a resin layer is formed by coating or the like, and the above resin layer is also formed between the outermost copper foil and the stacked sheets and the copper foil are integrated by thermocompression bonding. Was formed. By such a method, a metal-clad board for a printed wiring board having a relative dielectric constant of 2 to 3.5 and a dielectric loss tangent of about 0.0010 was produced.

  The fluororesin metal-clad substrate using the conventional glass cloth as described above has the dielectric properties and the dielectric loss tangent of the glass fiber higher than those of the organic fiber. Fully aromatic polyamide fibers, wholly aromatic polyester fibers, polybensoxazole fibers (PBO fibers), etc. have been proposed as reinforcing materials for printed wiring boards made of organic fibers instead of glass fibers, but aramid fibers and PBOs have been proposed. The fiber has a problem in hygroscopicity, and the wholly aromatic polyester fiber has a problem in heat resistance during processing.

Japanese Patent Laid-Open No. 7-304931 Japanese Patent Laid-Open No. 7-304933 Japanese Unexamined Patent Publication No. 11-087927 Japanese Patent Laid-Open No. 7-323501

  Therefore, the problem to be solved by the present invention is to find an organic fiber having small water absorption, dielectric constant and dielectric loss tangent and excellent heat resistance, and combining the organic fiber with a resin, which is suitable for high-speed communication. It is providing the laminated board for printed wiring boards.

  As a result of studying a laminate for a printed wiring board having a low dielectric constant and a low dielectric loss tangent suitable for high-speed communication, the inventors have found that an excellent laminated board for a printed wiring board can be obtained by using a specific fiber-reinforced substrate. As a result, the present invention was reached.

That is, the present invention is a laminate for a printed wiring board having a resin layer reinforced with a fiber base and a metal layer for a circuit, wherein the fiber base is
The following [A], [B], [C], [D] and [E] are composed of 90 mol% or more of repeating structural units, [A]: [B]: [C]: [D] : [E] = 100: 1 to 20: 5 to 100: 2 to 80: 2 to 20 and composed of an aromatic polyester amide having a molar ratio of
It is formed from a melt anisotropic polyesteramide fiber having a strength (T ₁₅₀ ) in a 150 ° C. atmosphere of 17 cN / dtex or more and an elastic modulus (E ₁₅₀ ) in a 150 ° C. atmosphere of 710 cN / dtex or more. It is the laminated board for printed wiring boards characterized by these.

In the polyesteramide fiber in the present invention, the temperature of the endothermic peak when thermal analysis is performed using DSC is preferably 370 ° C. or higher. Further, the ratio between the storage elastic modulus (E ′ ₂₅ ) measured from dynamic viscoelasticity in a 25 ° C. atmosphere and the storage elastic modulus (E ′ ₁₅₀ ) measured from dynamic viscoelasticity in a 150 ° C. atmosphere is E It is preferable that “ ₁₅₀ / E” ₂₅ = 0.50 or more. Furthermore, it is preferable that the α dispersion (considered as the glass transition point Tg) obtained by dynamic viscoelasticity measurement is 81 ° C. or higher. The crystal size calculated from the half width of the diffraction peak intensity appearing at 2θ = 29 ° obtained by wide-angle X-ray diffraction measurement is preferably 7 nm to 11 nm. It is preferable that the dry heat shrinkage in a 350 ° C. atmosphere is less than 1%.

  The fiber base material is preferably a woven fabric, nonwoven fabric or paper composed of the melt anisotropic polyesteramide fiber, and the fabric is composed of the melt anisotropic polyesteramide fiber yarn having a total fineness of 220 dtex or less. It is preferable.

  The temperature for heating the prepreg impregnated with or adhering the resin to the melt anisotropic polyester amide fiber is preferably 150 ° C. or higher, and the resin is preferably a fluororesin.

In the present invention, since the melt anisotropic polyesteramide fiber is used as a fiber base material, a printed wiring board laminate having a low dielectric constant and dielectric loss tangent and suitable for high-speed communication can be obtained.
Further, in the present invention, when the melt anisotropic polyester amide fiber is used, since the fiber is excellent in heat resistance, it can be laminated with a resin having a high curing temperature or molding temperature. An excellent laminate using a fluororesin having a high sintering temperature can be obtained.

  The melt anisotropic polyesteramide fiber (or aromatic polyesteramide fiber) used in the present invention is melt-spun from the aromatic polyesteramide described below.

(Aromatic polyester amide)
In the aromatic polyesteramide, the portion consisting of repeating structural units of [A], [B], [C], [D], and [E] represented by the following formula is 90 mol% or more, and [A]: [B ]: [C]: [D]: [E] = 100: 1 to 20: 5 to 100: 2 to 80: 2 to 20 molar ratio, preferably [A]: [B]: [C]: The molar ratio [D]: [E] has a molar ratio of 100: 3 to 10:15 to 60:10 to 45: 5 to 15.

  Here, [A]: [B]: [C]: [D]: [E] = 100: 1 to 20: 5 to 100: 2 to 80: 2 to 20 represents the repeating structural unit [A ] Of other structural units [B] to [E].

  In particular, from the viewpoints of spinnability, strength, elastic modulus, fatigue resistance, cut resistance, non-water absorption, etc., the structural unit [A] is 40 to 80 mol% among the recurring structural units shown in Chemical Formula 1 and is composed. An aromatic polyester amide in which the unit [D] is n = 2 is preferable.

  Other aromatic, alicyclic, aliphatic diols, and dicarboxylic acids to such an extent that the characteristics of the aromatic polyester amide fibers used in the present invention (hereinafter sometimes simply referred to as polyesteramide fibers) are not impaired. , Hydroxycarboxylic acid, diamine, hydroxyamine and the like may be contained. Specific examples include isophthalic acid, naphthylene dicarboxylic acid, dioxynaphthalene, and benzenediamine. However, if these monomers exceed 10 mol%, the characteristics of the aromatic polyesteramide fiber may be impaired.

  The melt anisotropy referred to in the present invention is to show optical anisotropy in the melt phase. For example, it can be recognized by placing the sample on a hot stage, heating and heating in a nitrogen atmosphere, and observing the transmitted light of the sample.

  The melt anisotropic polymer preferably has a temperature difference between the decomposition start temperature (Td) and the melting point (Tm) of 40 ° C. or more. Melt spinning is performed by heating the spinning machine to a temperature higher than the melting point. However, since the temperature changes with a certain width with respect to the set temperature, the temperature may be higher than the set temperature. If the temperature difference between the decomposition start temperature (Td) and the melting point (Tm) of the melt anisotropic polymer is less than 40 ° C., the temperature exceeds the melting point and reaches the decomposition temperature while the polymer stays in the pipe. -Decomposition occurs, and screws, that is, yarn breakage, occur near the spinning nozzle.

  Even when screws are not generated, bubbles that are considered to be decomposed gases are generated in the fiber, and the mechanical performance deteriorates. The decomposition start temperature (Td) described here is the decrease start temperature in the TG curve (thermogravimetric curve), and Tm described here is the main observed by the differential scanning calorific value (DSC: for example, TA3000 manufactured by Mettler). This is the peak top temperature of the endothermic peak, and may hereinafter be referred to as the melting point peak temperature (JIS K 7121).

(Aromatic polyester amide fiber)
The polyesteramide fiber used in the present invention can be obtained by melt spinning a polymer by a conventional method. The spinning temperature is 10 ° C. higher than the melting point of the aromatic polyesteramide (and the temperature range in which a molten liquid crystal is formed). ), And spinning is preferably performed under conditions of a shear rate of 10 ³ sec ⁻¹ or more and a spinning draft of 20 or more. By spinning at such a shear rate and a spinning draft, the orientation of the molecules proceeds and performance such as excellent strength can be obtained. The shear rate (γ) is calculated by r = 4Q / πr ³ where the nozzle radius is r (cm) and the polymer per single hole and the discharge amount are Q (cm ³ / sec). When the nozzle cross section is not a circle, the radius of a circle having an area equivalent to the cross-sectional area is defined as r.

  In order to obtain the fibers used in the present invention, it is necessary to heat and / or stretch the spinning raw yarn in order to improve strength, elastic modulus, fatigue resistance and cut resistance. The heat treatment may be performed only in an inert atmosphere, or may be performed in the active atmosphere from the middle.

  In addition, under inert atmosphere means in inert gas, such as nitrogen and argon, or under reduced pressure, and means that active gas, such as oxygen, is 0.1 volume% or less. The term “in an active atmosphere” refers to an atmosphere containing 1% or more of an active gas such as oxygen, preferably 10% or more of an oxygen-containing gas, and air is preferably used in terms of cost. When water is present, the hydrolysis reaction proceeds in parallel, so a dry gas having a dew point of −20 ° C. or lower, preferably −40 ° C. or lower is used.

  A preferable temperature condition for the heat treatment is a temperature range of Tm-35 ° C. to Tm-2 ° C. with respect to the melting point Tm of the polymer before melt spinning, and heating at such a temperature condition provides a high strength at a high temperature. In addition, a high-strength and high-modulus polyesteramide fiber capable of realizing the elastic modulus can be obtained. Further, the heat treatment may be performed at a constant temperature, or the temperature may be raised sequentially in accordance with the melting point of the fiber that gradually rises by heating.

The heat treatment conditions can also be expressed by the product of (temperature difference from melting point: ° C.) and (heating time: time) heated per single fiber fineness (dtex).
50 ≦ (temperature difference from melting point) × (heating time) / (single fiber fineness) ≦ 100
High-strength, high-elasticity polyesteramide having a strength (T ₁₅₀ ) in an atmosphere of 150 ° C. of 17 cN / dtex or more and an elastic modulus (E ₁₅₀ ) in an atmosphere of 150 ° C. of 710 cN / dtex or more Fibers can be obtained.

  When the heat is supplied by a medium such as a gas, a method using radiation by a heating plate, an infrared heater, etc., a method of making contact with a thermal roller, a plate, etc., a high frequency, etc. There is an internal heating method used, and it is performed under tension or no tension depending on the purpose. The heat treatment can be performed batchwise by making the filament yarn into a casket, cheese, or tow, or can be performed continuously while the filament is running on a roller. . Alternatively, the fibers may be cut fibers and heat treated by placing them on a wire mesh or the like.

  Further, the polyesteramide fiber used in the present invention may be an inorganic substance such as titanium oxide, kaolin, silica, barium oxide, a colorant such as carbon black, a dye or a pigment, an antioxidant, an ultraviolet absorber, if necessary. An additive such as a light stabilizer may be included.

  In the present invention, if necessary, thermoplastic polymers such as polyethylene terephthalate, polyolefin, polycarbonate, polyarylate, polyamide, polyphenylene sulfide, polyetheresterketone, polyurethane, and fluorine resin. It is good also as a composite yarn with the fiber formed from.

(Strength of polyester amide fiber)
The polyesteramide fiber used in the present invention has a strength (T ₁₅₀ ) in a 150 ° C. atmosphere of 17 cN / dtex or more (for example, about 17.5 to 40 cN / dtex), preferably 18 cN / dtex or more (for example, 18.5). ~ About 38 cN / dtex).

The polyesteramide fiber has a strength (T ₂₅ ) at room temperature (for example, 25 ° C.) of 18 cN / dtex or more (for example, about 18.5 to 45 cN / dtex), preferably 20 cN / dtex or more (for example, 20. 5-40 cN / dtex).

In addition, since the polyesteramide fiber has little change in strength between high temperature and low temperature, for example, the ratio between the strength at 150 ° C. atmosphere (T ₁₅₀ ) and the strength at 25 ° C. atmosphere (T ₂₅ ) is high. , T ₁₅₀ / T ₂₅ = 0.70 or more (for example, about 0.71 to 1.0), preferably 0.73 or more (for example, about 0.74 to 0.95).

Furthermore, the polyesteramide fiber has a ratio of T ₁₅₀ / T ₋₇₀ = 0.63, for example, the ratio between the strength (T ₁₅₀ ) in a ₁₅₀ ° C. atmosphere and the strength (T ₋₇₀ ) in a −70 ° C. atmosphere. It may be above (for example, about 0.64 to 1.0), preferably 0.65 or more (for example, about 0.66 to 0.95).

(Elastic modulus of polyester amide fiber)
The polyesteramide fiber used in the present invention has an elastic modulus (E ₁₅₀ ) under a 150 ° C. atmosphere of 710 cN / dtex or more (for example, about 720 to 1500 cN / dtex), preferably 730 cN / dtex or more (for example, 740 to 740). 1400 cN / dtex).

The polyesteramide fiber has an elastic modulus (E ₂₅ ) at room temperature (for example, 25 ° C.) of 750 cN / dtex or more (for example, about 755 to 1500 cN / dtex), preferably 760 cN / dtex or more (for example, 765 to 1300 cN). / Dtex).

Further, since the polyesteramide fiber has little change in elastic modulus at high temperature and low temperature, for example, the elastic modulus (E ₁₅₀ ) in an atmosphere at 150 ° C. and the elastic modulus (E ₂₅ ) in an atmosphere at 25 ° C. The ratio of E ₁₅₀ / E ₂₅ = 0.85 or more (for example, about 0.86 to 1.0), preferably 0.87 or more (for example, about 0.88 to 0.98). .

(Melting point of polyester amide fiber)
The polyesteramide fiber used in the present invention has high heat resistance, and its melting point peak temperature is 370 ° C. or higher (for example, about 375 to 450 ° C.), preferably 380 ° C. or higher (for example, about 385 to 440 ° C.). May be. In addition, about the measuring method of melting | fusing point peak temperature, it describes in the following Example in detail.

(Dynamic viscoelasticity of polyester amide fiber)
Since the polyesteramide fiber used in the present invention exhibits excellent storage elastic modulus (or dynamic elastic modulus) both at high temperature and low temperature, the storage elastic modulus (E) measured from dynamic viscoelasticity in a 25 ° C. atmosphere. _'25), under 150 ° C. atmosphere, storage modulus measured from the dynamic viscoelasticity (E' ratio and _150), E _'150 / E' ₂₅ = 0.50 or more (e.g., 0.51 1.0), and preferably 0.52 or more (for example, about 0.53 to 0.90). The polyesteramide fiber having such a storage elastic modulus can reduce changes in physical properties at room temperature (for example, at 25 ° C. atmosphere) and high temperature (for example, at 150 ° C. atmosphere).

  In the polyesteramide fiber used in the present invention, the glass transition point (Tg) obtained by dynamic viscoelasticity measurement may be 81 ° C. or higher (for example, about 81 to 118 ° C.), preferably 83 ° C. or higher. (For example, about 84 to 110 ° C.). The polyesteramide fiber having such a glass transition point can exhibit almost the same physical properties as those at room temperature. In addition, about the measuring method of a storage elastic modulus and a glass transition point, it describes in detail in the following examples.

(Crystal size)
The polyesteramide fiber used in the present invention preferably has a high melting point crystal structure in the molecular structure from the viewpoint of developing high strength and elastic modulus at high temperatures. With respect to the crystal, the crystal size can be calculated from the half-value width of the diffraction peak intensity appearing at 2θ = 29 ° obtained by wide-angle X-ray diffraction measurement. It may be about 11 nm, and preferably about 8 nm to 10 nm. Specific measurement methods are described in detail in the following examples.

(Dry heat shrinkage of polyester amide fiber)
Since the polyesteramide fiber has high form stability in a high-temperature atmosphere, the dry heat shrinkage obtained by a dry heat shrinkage test is 1% or less (for example, about 0.01 to 0.95%), 0.8 % Or less (for example, about 0.05 to 0.75%). In addition, the dry heat shrinkage said by this invention is a value calculated | required by the dry heat shrink test described in the Example, and the measuring method is described in the following Examples.

  The cross section of the polyesteramide fiber used in the present invention may be a round cross section or a fan flat cross section. Further, it may be a core-sheath or sea-island composite fiber. In the case of sea-island fibers, a thinner fiber substrate can be obtained by removing the sea component by using melt-anisotropic polyesteramide as the island component and other polymers as the sea component. preferable.

  The single fineness of the polyesteramide fiber used in the present invention is preferably 7.5 decitex (dtex) or less, more preferably 5.5 decitex (dtex), and even more preferably 2.8 decitex or less. As the single fineness is smaller, a thinner woven fabric, nonwoven fabric, or paper can be obtained.

(Structure of fiber base material)
In the present invention, the fiber substrate made of aromatic polyester amide fiber is used in structures such as woven fabric, non-woven fabric, and paper. The woven fabric may be not only plain weave but also twill weave, satin weave, etc. The total fineness of the warp and weft constituting the fabric is preferably 220 dtex or less. If it exceeds 220 dtex, a thin fabric cannot be obtained, which is not preferable from the viewpoint of multilayering and increasing the density of the printed wiring board. Moreover, in the case of a woven fabric, it is preferable that a fiber is subjected to fiber opening treatment because a thinner woven fabric can be obtained.

  As the nonwoven fabric, an aromatic polyester amide polymer is melt-spun and accumulated in a sheet form to form a long-fiber nonwoven fabric, or the polymer is blown into a fiber shape by a melt blown and collected in a wire mesh by suction to form a nonwoven fabric. Or may be formed. An aromatic polyesteramide fiber nonwoven fabric having a predetermined performance can be obtained by performing heat treatment after the nonwoven fabric is formed.

  As the paper, the above-mentioned sea-island fiber is cut into a suitable length (for example, 5 mm or less) that can be used for papermaking, and then a paper material containing pulp-like material obtained by dissolving and removing sea components is wet-paper-made. The paper base material comprised from the aromatic polyesteramide fiber which has a predetermined | prescribed performance is obtained.

  The thickness of the fiber base material such as woven fabric, non-woven fabric or paper is preferably 100 μm or less. Especially preferably, it is 80 micrometers or less, Most preferably, it is 50 micrometers or less. The thinner the thickness is, the more the blind wiring board can be multilayered and the higher the density.

  In the present invention, the fiber substrate is not limited to those formed from the aromatic polyesteramide fiber alone, and within the range not impairing the object of the present invention, inorganic fibers such as glass fibers, Other organic fibers may be included.

(Impregnation / adhesion of resin to fiber substrate)
In the present invention, in order to reinforce the resin with the fiber base material, impregnation or adhesion of the resin to the fiber base material is performed, but the impregnation or adhesion method is not particularly limited, and any conventionally known method can be used. it can. For example, an impregnation method, a coating method, a transfer method, or the like may be employed. Specifically, a method of dissolving a resin in a solvent and impregnating the fiber base material and drying, a method of impregnating the fiber base material with a liquid resin in a normal temperature state or a heated state adjusted without using a solvent, The fiber base material can be impregnated and adhered to the resin by a method of fixing the resin to the fiber base material, a method of forming a resin layer on a film / sheet having releasability and transferring it to the fiber base material, etc. . The fiber base material may be subjected to plasma treatment, corona treatment, UV treatment, heat treatment in air, etc. in order to improve the impregnation property of the resin into the fiber base material or the adhesion to the resin.

(Prepreg)
A prepreg is obtained by impregnating or adhering a resin to a fiber substrate. There is no restriction | limiting in particular about content of the resin in a prepreg, In order to suppress delamination and a shaping | molding defect, Usually, 30-95 mass% of the total mass of a prepreg, Preferably, resin occupies 40-80 mass%. It is preferable to do.
A laminated board for printed wiring board can be obtained by superposing a copper foil on a prepreg obtained by impregnating a fiber base material with a thermosetting resin and making it semi-cured, followed by hot pressing. A prepreg can also be obtained by melting a thermoplastic resin and impregnating the fiber base material. A prepreg can also be obtained by laminating a thermosetting resin film or a thermoplastic resin film on a fiber substrate. A laminate can be obtained from these prepregs by a known method. In this case, in order to improve the adhesiveness of the film, the film surface may be subjected to plasma treatment or corona treatment.

(Resin impregnated or adhered)
In the present invention, the resin impregnated or attached to the aromatic polyester amide fiber is not particularly limited, and is a resin composed of only a thermosetting component, a thermoplastic resin, or a resin composed of a thermoplastic resin and a thermosetting component. May be. Examples of the thermosetting component include epoxy resins, phenol resins, thermosetting polyimide resins, unsaturated polyester resins, cyanate resins, and maleimide resins. Examples of the thermoplastic resin include fluororesin, polypropylene, polyethylene, thermoplastic liquid crystal polymer resin (LCP) including liquid crystal polyester, polyphenylene sulfide (PPS), thermoplastic polyimide resin, and polyethersulfone resin. be able to. You may use together said thermosetting component and a thermoplastic resin. In the present invention, among the above resins, a fluororesin having excellent dielectric properties is preferable.

(Fluorine resin)
Specific examples of the fluororesin include polytetrafluoroethylene (PTFE fiber, melting point 327 ° C.), tetrafluoroethylene / hexafluoropropylene copolymer (FEP, melting point 275 ° C.), tetrafluoroethylene / perfluoroalkyl vinyl ether. Copolymer (PFA, melting point 3100 ° C.), polychlorotrifluoroethylene (PCTFE, melting point 220 ° C.), polyvinylidene fluoride (PVDF, melting point 156 to 178 ° C.), ethylene / tetrafluoroethylene copolymer (ETFE, melting point 270) ° C), ethylene / chlorotrifluoroethylene copolymer (ECTFE, melting point 220 to 245 ° C), tetrafluoroethylene / hexafluoropropylene / perfluoroalkyl vinyl ether copolymer (EPE, melting point 295 ° C). . However, PTFE has a low relative dielectric constant and dielectric loss tangent and is excellent in heat resistance and chemical resistance, so it is preferable for the laminate of the present invention. Can also be used.

(Polyimide resin)
In the present invention, it is also possible to use a polyimide resin that is considered useful for heat resistance and low dielectric constant. Generally, a polyimide resin is used as a polyimide film, but most of the polyimide resin is a film made of a single polyimide. For example, a high temperature treatment is required to perform heat treatment to develop adhesiveness. That is, commercially available polyimide films include (a) a film formed of a polyimide alone, (b) a polyimide film coated with a rubber-based or acrylic pressure-sensitive adhesive (adhesive), etc. Since the film (a) has low adhesiveness, it can only be heated and softened above the softening point. The softening point of polyimide is usually as high as 250 ° C. or higher. However, the polyesteramide fiber excellent in heat resistance used in the present invention can be pressure-bonded at a high processing temperature of 150 ° C. or higher. In the case of the film (b), it can be bonded at a relatively low temperature.

(Formation of inorganic fine particles)
In the present invention, when it is desired to increase the relative dielectric constant of the laminate and / or to further improve the dimensional stability, inorganic fine particles can be added to the resin. By selecting and blending the types of inorganic fine particles, the dielectric loss tangent of the laminate is kept low, the relative permittivity is increased, and the thermal expansion coefficients and dimensional changes in the X direction, Y direction and two directions of the metal-clad substrate are suppressed, and the substrate Mechanical strength such as bending strength and flexural modulus can also be improved. Examples of the inorganic fine particles used in the present invention include talc, alumina, glass, silica, mica, and the like, among which silica is preferable.

  In this invention, you may add other additives, such as a hardening accelerator, as needed within the range which does not impair the property made into the objective of this invention.

(Molding conditions for laminates)
Use one or two or more prepregs impregnated / attached to the fiber base material used in the present invention, and if necessary, further other materials are used together, and these are laminated with a metal foil. A laminated board for printed wiring boards can be produced by applying pressure and heating together to cure or solidify the resin and perform interlayer adhesion. In particular, in the present invention, since a polyesteramide fiber excellent in high-temperature performance is used as a fiber base material, the temperature at which the prepreg is heated is 150 ° C. or higher, for example, 200 ° C. or higher, and further at a high temperature of about 300 to 400 ° C. Processing is possible. Conventionally, it is possible to produce a laminate at a processing temperature that has been difficult with organic fibers.

  An example of molding conditions when PTFE is used as the fluororesin is that a PTFE resin sheet and a copper foil are disposed on both sides of the polyesteramide fiber fabric (in some cases, on one side), and the temperature of the PTFE melting point is 327 ° C. or more, for example, 380 A copper-clad laminate for a printed wiring board can be obtained by performing thermocompression bonding with a vacuum press for 90 minutes under the conditions of ° C and pressure of IMpa.

(Manufacture of wiring boards)
After obtaining the above-mentioned fluororesin laminate, a post-process for forming a conductive layer of a circuit pattern can be performed to obtain a fluororesin printed wiring board provided with a conductive path of a desired pattern. The pattern formation is performed using a peeling development type photoresist, a melt development type photoresist, or the like. For example, an alkali development type photoresist film is formed on the copper foil surface, and a desired pattern is exposed through a photomask. Next, the exposed portion of the copper foil is removed by etching or the like, and the exposed portion of the photoresist is dissolved and removed to obtain a fluororesin printed wiring board having a conductive layer having a desired pattern.

(Metal layer for circuit)
In addition, as the metal foil used for forming the metal layer for circuits in the present invention, a single foil such as copper, aluminum, true mirror, nickel, iron, alloy foil, composite foil, etc. can be used. Copper foil is preferable in terms of good electrical conductivity. In this case, either electrolytic copper foil or rolled copper foil may be used. Moreover, the metal foil which has already become a circuit pattern as a metal foil can also be used. Moreover, the adhesive bond layer can be provided in the single side | surface of metal foil as needed. Further, the metal foil surface may be coupled. Although the thickness of metal foil is not specifically limited, Thickness 9-35 micrometers is preferable at the surface which ensures the processing precision of a high frequency printed circuit. The relative dielectric constant of the metal-clad board for printed wiring boards of the present invention produced as described above can be adjusted by the type and blending amount of the polyesteramide fiber and inorganic fine particles.

  Hereinafter, the present invention will be further described with reference to examples, but the present invention is not limited thereto.

[Melting point peak temperature]
10-20 mg of a sample is taken in a DSC apparatus (TA3000 manufactured by METTLER), sealed in an aluminum pan, N ₂ is flowed as a carrier gas at 100 cc / min, and measured at a temperature rising rate of 20 ° C./min. Measure the temperature indicated by the

[Strength and elastic modulus]
According to JIS L 1013, the fracture strength and elastic modulus (initial tensile resistance) are determined under the conditions of a test length of 20 cm, an initial load of 0.1 g / d, and a tensile speed of 10 cm / min, and an average value of 5 or more points is adopted. did.

[Crystal size]
Using “D8 Discover with GADDS” manufactured by Bruker as a wide-angle X-ray diffractometer, the camera distance is 10 cm, the exposure time is 600 seconds, the current is 110 mA, the voltage is 45 kV, and the collimator diameter is 0.3 mm. A wide-angle X-ray diffraction diagram was obtained. Next, the crystal size (C) was calculated from the half width of the diffraction peak intensity at which 2θ appears at 29 ° using the following formula.

  Here, B represents the half width of the diffraction peak intensity, θ represents the diffraction angle, and λ represents the X-ray wavelength (1.54178 angstroms).

[Storage modulus, loss modulus and glass transition point due to dynamic viscoelasticity]
Using a “DVE Rheospectr” manufactured by Rheology, the temperature is increased at a rate of 10 ° C./min, the frequency is 10 Hz, and an automatic static load method is used to measure the storage elastic modulus (E ′) and loss elastic modulus (E ″). From the ratio, tan δ = E ″ / E ′ was calculated. Next, for each temperature, a temperature (° C.)-Tan δ curve was drawn with the horizontal axis as the temperature and the vertical axis as tan δ, and the inflection point (peak temperature) of tan δ was defined as the glass transition point. Moreover, to calculate the ratio between the storage elastic modulus under a 25 ° C. atmosphere (E _'25) and storage modulus under 0.99 ° C. atmosphere (E' ₁₅₀₎ as E _'150 / E' _25.

[Measurement of dry heat shrinkage]
When a sample length of 0.1 g / d was applied to the sample, the sample length was L, and this was exposed in a hot air dryer for 10 minutes in an atmosphere at 350 ° C., and then the sample length measured in the same manner was L ′ ( L−L ′) / L × 100.

<Example 1>
(Polyester amide fiber)
60 mol of p-acetoxybenzoic acid [A], 4 mol of 6-acetoxy-2-naphthoic acid [B], 18 mol of terephthalic acid [C], 14 mol of 4-4′-bisphenol [D], and p- Melt anisotropic aromatic polyester amide was obtained from 4 mol of aminophenol [E]. The melting point of this polymer was 340 ° C. The polymer was melt-spun from a die having a nozzle diameter of 0.1 mmφ and a number of holes of 40 with a spinning temperature of 360 ° C., a spinning speed of 1000 m / min, a shearing speed of 55200 sec ⁻¹ , and a draft of 30 and a filament of 110 dtex / 40 f. Got.
The fiber performance of the obtained spinning yarn is
Strength (DT) = 8.8 cN / dtex
Elongation (DE) = 1.7%
Elastic modulus (YM) = 590 cN / dtex
Met. This spinning yarn was heat-treated at 310 ° C. for 8 hours. The obtained heat-treated yarn (polyester amide fiber) hardly showed any interfiber sticking.

  As shown in Table 1, physical properties of the heat-treated polyester amide fiber were excellent in heat resistance.

(Laminated board)
Using the obtained polyesteramide fiber, a plain woven fabric (weave density: 35 / inch) is made, and a fluororesin dispersion (manufactured by Mitsui DuPont Fluorochemical Co., Ltd., Teflon (R) 34-JR) Was heat treated through an electric furnace heated and adjusted to 380 ° C., and PTFE resin was fused to obtain a prepreg. Three sheets of the obtained prepregs were stacked and pressure-bonded for 90 minutes by pressurizing IMpa and heating at 380 ° C. under vacuum to obtain a laminated board for printed wiring board of the present invention. The obtained laminated plate had a low dielectric constant and dielectric loss tangent and was suitable for high-speed communication.
In addition, three prepregs obtained were stacked, and an electrolytic copper foil (made by Fukuda Metal Foil Industry Co., Ltd., trade name: CF1T9, thickness 18 μm) was stacked on top and bottom of the prepreg, and vacuum was applied in the same manner as above. Under pressure, pressure was applied at IMPa and heat was applied at 380 ° C. for 90 minutes, and a copper-clad laminate could be obtained.

<Comparative Example 1>
A plain fabric of polyester amide fiber was obtained in the same manner as in Example 1 except that the spinning yarn obtained in Example 1 was treated at 290 ° C. for 8 hours. Table 1 shows the performance of the obtained polyamide ester fiber. This woven fabric was impregnated with a fluororesin in the same manner as in Example 1 and heat-treated through an electric furnace, but a part of the woven fabric was melted and cut during the heat treatment, and a prepreg could not be obtained.

<Comparative example 2>
A melt anisotropic aromatic polyester was obtained from 73 mol of p-acetoxybenzoic acid [A] and 27 mol of 6-acetoxy-2-naphthoic acid [B]. The melting point of this polymer was 280 ° C. The polymer was melt-spun from a die having a nozzle diameter of 0.1 mmφ and a number of holes of 40 with a spinning temperature of 310 ° C., a spinning speed of 1000 m / min, a shearing speed of 55200 sec ⁻¹ , and a draft of 30 and a filament of 110 dtex / 40 f. Got.
This spinning yarn was heat-treated at 275 ° C. for 8 hours. The obtained heat treated yarn had almost no interfiber sticking. The obtained aromatic polyester fiber was made into a plain woven fabric in the same manner as in Example 1, impregnated with a fluororesin, and heat-treated through an electric furnace, but part of the woven fabric was melted and cut during the heat treatment to obtain a prepreg. There wasn't.

A printed wiring board can be obtained by performing wiring processing on the conductor layer of the laminated board for printed wiring board reinforced with the melt anisotropic polyesteramide fiber of the present invention. Since the obtained printed wiring board has an insulating layer having a low dielectric constant and dielectric loss tangent, it is used as a printed wiring board for high-frequency circuits. Further, a multilayer printed wiring board having excellent high-frequency signal transmission characteristics can be obtained by multilayering the prepregs and electrically connecting the layers by a known method.
An electronic component having a high-frequency circuit formed on a printed wiring board according to the present invention has a low dielectric constant and dielectric loss tangent, so that high-speed and large-capacity communication is possible, and a network such as a server, router, mobile phone base station, etc. It may be widely used in equipment, semiconductor test equipment, measuring instruments, etc.

  As described above, the preferred embodiments of the present invention have been described, but various additions, modifications, or deletions are possible without departing from the spirit of the present invention, and such modifications are also included in the scope of the present invention. It is.

Claims (5)

In a laminate for a printed wiring board having a resin layer reinforced by a fiber substrate and a metal layer for a circuit,
The fiber base material includes 90 mol% or more of a repeating unit composed of the following [A], [B], [C], [D], and [E], and [A]: [B]: [ C]: [D]: [E] = 100: 1 to 20: 5 to 100: 2 to 80: 2 to 20 and composed of an aromatic polyester amide having a molar ratio of:
It is formed from a melt anisotropic polyesteramide fiber having a strength (T ₁₅₀ ) in a 150 ° C. atmosphere of 17 cN / dtex or more and an elastic modulus (E ₁₅₀ ) in a 150 ° C. atmosphere of 710 cN / dtex or more. A laminated board for printed wiring boards characterized by

  The printed wiring board laminate according to claim 1, wherein the fiber base material is a woven fabric, a nonwoven fabric or paper composed of the melt anisotropic polyesteramide fiber.   The printed wiring board laminate according to claim 2, wherein the woven fabric is composed of the melt anisotropic polyesteramide fiber yarn having a total fineness of 220 dtex or less.   The laminated board for printed wiring boards according to any one of claims 1 to 3, wherein a temperature for heating the prepreg in which the resin is impregnated or adhered to the melt anisotropic polyester amide fiber is 150 ° C or higher.   The printed wiring board laminate according to claim 1, wherein the resin is a fluororesin.