JP6156079B2 - Metal-clad laminate and method for producing the same, printed wiring board using the same, and method for producing the same - Google Patents

Description

  The present invention relates to a metal-clad laminate used for a printed wiring board, a method for manufacturing the same, and a printed wiring board using such a metal-clad laminate.

  In recent years, information terminals such as personal computers, servers, and communication devices such as Internet routers and optical communication have been required to process large volumes of information at high speed, and the speed and frequency of electrical signals have been increased. Yes. As a result, the laminates for semiconductor plastic packages used in these products have a low dielectric constant and a low dielectric constant in the insulating layer of the printed wiring board in addition to the conventionally required properties such as heat resistance and peel strength with the metal layer. Tangentization is required, and various attempts have been made to meet these characteristic requirements. In addition, due to the difference in thermal expansion between the semiconductor element and the laminated sheet for the semiconductor plastic package, the warping of the package occurs, resulting in poor connection. Therefore, there is a strong demand for reducing the thermal expansion coefficient in the plane direction of the laminated board. There is a demand for a material having a composite property such as low dielectric constant, low dielectric loss tangent, and low coefficient of thermal expansion.

  Up to now, epoxy resins and cyanate ester resins have been used as insulating layers for laminates for the purpose of lowering the dielectric constant and lowering the dielectric loss tangent. However, these resins have a high water absorption rate and have a high frequency range. However, there was a problem that the dielectric constant was likely to change. Therefore, a liquid crystal polymer (Liquid Crystal Polymer: LCP) with low water absorption and a small change in dielectric constant in a high frequency region is used, and an insulating layer (LCP substrate) formed by stacking a plurality of LCP films is provided. A high-frequency circuit board has been proposed (see, for example, Patent Document 1). Further, in order to reduce the thermal expansion coefficient in the surface direction of the insulating layer, there is a method of increasing the filling amount of the inorganic filler with respect to the resin composition as the material of the insulating layer (for example, Patent Document 2 and 3).

JP 2000-269616 A JP 2004-059643 A JP 2009-120702 A

  However, the LCP substrate disclosed in Patent Document 1 has a large coefficient of thermal expansion in the surface direction, and an external shape abnormality such as warpage may occur during heat treatment, which causes a problem in manufacturing the substrate. It was. In addition, in the insulating layer using the resin composition disclosed in Patent Documents 2 and 3, due to the influence of a large amount of inorganic filler, the dielectric constant and dielectric loss tangent increase, and it is difficult to achieve both of these characteristics. There was a problem that there was.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a metal-clad laminate having excellent dielectric properties and low thermal expansion.

  In order to achieve the above object, the present inventors have conducted intensive research on the composition and manufacturing method of the insulating layer used in the metal-clad laminate. As a result, the base material (A) and the liquid crystal polymer (B) woven cloth are pressure-bonded in a state of being laminated so that the fiber directions of the respective woven cloths are in the same direction. The liquid crystal polymer (B) is attached to the metal-clad laminate and used as an insulating layer of the metal-clad laminate, thereby making it possible to achieve both excellent dielectric properties and low thermal expansion. Reached.

  That is, the gist of the present invention is a metal-clad laminate including a base material (A) and an insulating layer containing a liquid crystalline polymer (B) attached to the base material (A), and a metal layer provided on the insulating layer. A board, and an insulating layer is bonded in a state where the woven fabric of the base material (A) and the woven fabric of the liquid crystalline polymer (B) are laminated so that the fiber directions of the respective woven fabrics are in the same direction. The present invention relates to a metal-clad laminate.

Another gist of the present invention is a method for producing the metal-clad laminate, wherein the woven fabric of the base material (A) and the woven fabric of the liquid crystalline polymer (B) are made of fibers of each woven fabric. The present invention relates to a method including forming an insulating layer by pressure bonding in a state where the layers are stacked in the same direction.
Another gist of the present invention relates to a metal-clad laminate produced by the above method.

Another gist of the present invention is a method of manufacturing a printed wiring board having a metal wiring pattern provided on an insulating layer, wherein the metal wiring pattern is formed by patterning the metal layer of the metal-clad laminate. It relates to a method comprising forming.
Another gist of the present invention relates to a printed wiring board manufactured by the above method.
Another gist of the present invention is a printed wiring board in which a metal wiring pattern is provided on an insulating layer containing a base material (A) and a liquid crystalline polymer (B) attached to the base material (A). The insulating layer was formed by press-bonding the woven fabric of the base material (A) and the woven fabric of the liquid crystalline polymer (B) so that the fiber directions of the woven fabrics were in the same direction. The present invention relates to a printed wiring board.

The metal-clad laminate according to the present invention has a low dielectric constant and dielectric loss tangent, has excellent dielectric properties, and has low thermal expansion in the surface direction. Therefore, the metal-clad laminate according to the present invention is suitable as a printed wiring board material.
Moreover, according to the manufacturing method of the metal-clad laminate which concerns on this invention, it becomes possible to obtain the above-mentioned outstanding metal-clad laminate efficiently.

  Embodiments of the present invention will be described below. In addition, the following embodiment is an illustration for demonstrating this invention, and this invention is not limited only to the embodiment.

[Metal-clad laminate]
The present invention is a metal-clad laminate comprising a base material (A) and an insulating layer containing a liquid crystalline polymer (B) attached to the base material (A), and a metal layer provided on the insulating layer. The insulating layer was formed by press-bonding the woven fabric of the base material (A) and the woven fabric of the liquid crystalline polymer (B) so that the fiber directions of the woven fabrics were in the same direction. The present invention relates to a metal-clad laminate. The liquid crystalline polymer is attached to at least one side of the substrate (A), but may be attached to both sides. The metal layer is disposed on at least the surface of the insulating layer to which the liquid crystalline polymer (B) is attached. The metal layer may be disposed on at least one surface of the insulating layer, but may be disposed on both surfaces of the insulating layer. In addition, a plurality of metal layers and / or insulating layers may be laminated, and a plurality of metal-clad laminates may be laminated.

[Metal layer]
The metal material used for the metal-clad laminate is not limited as long as it has conductivity, and any metal that can be used for a printed wiring board can be used. Examples of the metal generally used as the metal layer of the printed wiring board include, but are not limited to, copper, gold, lead, tin, nickel, and the like. It is also possible to use an alloy made of any two or more kinds of metals. Of these, copper is preferred. The thickness of the metal layer is determined according to the type and thickness of the metal foil to be used and the conditions during pressure bonding, and is arbitrarily selected according to the use of the metal-clad laminate.

  If the metal foil used for manufacture of a metal-clad laminated board is a well-known metal foil used for a printed wiring board, it can be especially used without a restriction | limiting. An electrolytic metal foil obtained by electrolysis of the metals listed above or a rolled metal foil obtained by rolling can be used. The metal foil may be subjected to a known surface treatment, such as nickel or cobalt treatment, or a roughening treatment is performed on the metal foil surface from the viewpoint of attaching the metal foil to the insulating layer and forming the metal layer. It may be broken. The surface roughness (Rz) of the metal foil surface is preferably 4 μm or less, more preferably 2 μm or less. In addition, Rz means the 10-point average roughness prescribed | regulated by JISB0601. The thickness of the metal foil may be appropriately selected according to the thickness of the metal layer described above, the conditions at the time of pressure bonding, and the like, for example, in the range of 1 to 150 μm.

[Insulation layer]
The insulating layer refers to an insulating layer that supports a conductive metal layer. In the present invention, the insulating layer includes a base material (A) and a liquid crystalline polymer attached to the base material (A). The insulating layer of the present invention melts the woven fabric of the liquid crystalline polymer (B) by pressure bonding in a state where the woven fabric of the substrate (A) and the woven fabric of the liquid crystalline polymer (B) are laminated. It is formed by attaching to the woven fabric of the substrate (A). The liquid crystalline polymer (B) may be attached to one side of the substrate (A), or the liquid crystalline polymer (B) may be attached to both sides of the substrate (A). The thickness of the insulating layer can be arbitrarily determined according to the conditions during pressure bonding, the use of the metal-clad laminate, and the like.

[Base material (A)]
The base material (A) is a material used as a reinforcing material for the insulating layer, and the insulating layer is formed by attaching the liquid crystalline polymer (B). As the substrate (A), a woven fabric made of fibers is used. Examples of the fibers constituting the woven fabric of the substrate (A) include inorganic fibers such as glass fibers, quartz glass fibers, carbon fibers, alumina fibers, silicon carbide fibers, albestos, rock wool, slag wool, and gypsum whiskers. . From the viewpoint of reducing the linear thermal expansion coefficient of the insulating layer, glass fiber is preferable. Here, the glass fiber is a fiber obtained by melting and pulling glass into a fiber shape, and is a fiber containing various metal oxides as subcomponents in addition to silicon dioxide. The glass fiber used for the base material (A) is not limited to the following, but E glass fiber, T glass fiber, Q glass fiber, NE glass fiber, etc. may be mentioned depending on the ratio of the components. It is done. Among these, T glass fibers and NE glass fibers are more preferable, and T glass fibers are most preferable. Preferable examples of the substrate (A) include glass fiber woven fabrics such as E glass, D glass, S glass, T glass, NE glass woven fabric, and woven fabrics such as quartz.

  The thickness of the base material (A) may be appropriately determined according to the thickness of the desired insulating layer described above and the conditions at the time of pressure bonding, but is usually preferably 1 μm or more from the viewpoint of improving the handleability. More preferably, it is 3 μm or more, especially 5 μm or more. However, from the viewpoint of sufficiently attaching the liquid crystalline polymer (B) to the base material (A), the upper limit value of the thickness of the base material (A) is usually 300 μm or less, particularly 250 μm or less, more preferably 200 μm or less, particularly 120 μm or less. Is preferred.

  The woven fabric is a fabric in which the fibers are formed into a sheet shape by plain weaving, Nanako weaving, twill weaving or the like, but is not limited to the weaving method. The woven fabric has at least two fiber directions. Usually, the woven fabric has two fiber directions, and the fiber directions may or may not be orthogonal to each other. On the other hand, it may have three or more fiber directions. For example, a triaxial woven fabric or a multiaxial woven fabric in which the fiber directions intersect at an angle of 60 ° may be used. To woven fabric having two orthogonal fiber directions is preferred. The woven fabric of the substrate (A) and the woven fabric of the liquid crystalline polymer (B) may have a different number of fiber directions, but from the viewpoint of aligning the fiber directions, the same number of fiber directions. It is preferable that the crossing angle in each fiber direction is the same. A woven fabric that has been subjected to an ultra-opening process or a plugging process is preferable from the viewpoint of dimensional stability.

  The number of woven fabrics of the base material (A) is not particularly limited, but is preferably in the range of 20 / inch (about 7.9 / cm) to 100 / inch (about 39.4 / cm). The lower limit of the number of driving is selected from the group consisting of 20, 30, and 40 / inch (about 7.9, 11.8, and 15.7 / cm respectively), and the upper limit of the driving number is 60, Selected from the group consisting of 70, 80, 90, and 100 / inch (approximately 23.6, 27.6, 31.5, 35.4, and 39.4 / cm, respectively) Is done. The number of warps and wefts may be the same as or different from each other as long as the numbers are within the ranges of the numbers described above. Among these, the range of 20 / inch (about 7.9 / cm) to 100 / inch (about 39.4 / cm) is preferable.

The substrate (A) woven fabric may be a known woven fabric used for various printed wiring board materials. As a specific example, for example, a glass cloth, for example, Style 1027MS manufactured by Asahi Schavel Co., Ltd. (Warn density 75/25 mm, Weft density 75/25 mm, Fabric weight 20 g / m ² , Thickness 19 μm (E glass fiber)), Style 1037MS (A warp density 70/25 mm, Weft) manufactured by Asahi Schwer Density 73/25 mm, fabric weight 24 g / m ² , thickness 28 μm (E glass fiber)), 1078 manufactured by Arisawa Manufacturing Co., Ltd. (warp density 54/25 mm, weft density 54/25 mm, fabric weight 48 g / m ^2, a thickness of 43 .mu.m (E glass fibers), Ltd.) Arisawa Seisakusho 2116 (warp density 50 lines / 25 mm, weft density 58 present / 25 mm, fabric weight 103.8 g / m ² The thickness 94Myuemu (E glass fibers), Ltd.) Arisawa Seisakusho 1067 (warp density 70 yarns / 25 mm, weft density 70 yarns / 25 mm, fabric weight 31 g / m ^2, a thickness of 33 .mu.m (E glass fiber)), Quartz glass cloth (IPC standard 2116 type cloth or IPC standard 1035 type cloth (Q glass fiber)) manufactured by Shin-Etsu Quartz Co., Ltd., T glass cloth (IPC standard 1078, 1035, 1037, 1027 (T glass) Fiber)), and Nittobo NE glass cloth (NE2013).

[Liquid crystal polymer]
The liquid crystalline polymer (B) refers to a polymer that exhibits a liquid crystal structure. The type of the liquid crystalline polymer (B) is arbitrary and is not limited, and examples thereof include liquid crystal polyester and liquid crystal polyester amide. Among these, liquid crystalline polyester is preferable from the viewpoint of electrical characteristics suitable for use in a printed wiring board.

  Examples of liquid crystalline polymers include polymers obtained by polymerizing one or more monomers selected from the compounds (i) to (iv) and their derivatives exemplified below. .

上記式中、Ｘは、水素原子、ハロゲン原子、低級（Ｃ１〜Ｃ６）アルキル基、フェニル基等のアリール基等を指す。Ｙは、−Ｏ−基、−ＣＨ₂−基、−Ｓ−基等の二価の基を指す。ｎは、２〜１２の整数を指す。 (I) Aromatic or aliphatic dihydroxy compounds

In the above formula, X represents a hydrogen atom, a halogen atom, a lower (C1-C6) alkyl group, an aryl group such as a phenyl group, or the like. Y refers to a divalent group such as a —O— group, a —CH ₂ — group, and a —S— group. n refers to an integer of 2 to 12.

上記式中、ｎは、２〜１２の整数を指す。 (Ii) aromatic or aliphatic dicarboxylic acids

In the above formula, n represents an integer of 2 to 12.

上記式中、Ｘは、水素原子、ハロゲン原子、低級（Ｃ１〜Ｃ６）アルキル基、フェニル基等のアリール基等を指す。 (Iii) Aromatic hydroxycarboxylic acid

In the above formula, X represents a hydrogen atom, a halogen atom, a lower (C1-C6) alkyl group, an aryl group such as a phenyl group, or the like.

(Iv) Aromatic diamine, aromatic hydroxyamine or aromatic aminocarboxylic acid

  The liquid crystalline polymer produced from the monomers listed above may be a homopolymer composed of a single monomer, or a copolymer composed of two or more monomers in any combination and ratio. One type of these liquid crystalline polymers may be used, or two or more types may be used in any combination and ratio.

  As the liquid crystalline polyester, any polymer may be used as long as it is a polymer in which an ester bond is included in a bond between monomers and exhibits a liquid crystal structure. However, from the viewpoint of obtaining a liquid crystalline polyester having excellent electrical characteristics, a liquid crystalline polymer having a structure represented by the following formulas (1) to (3) is particularly preferable.

  In the above formulas (1) to (3), x and y each represents an integer of 1 or more. Specific values of x and y are determined according to the polymer production conditions and molecular weight. Moreover, although the terminal of each polymer is determined according to manufacturing conditions etc., normally a hydrogen atom, -OH group, a lower (C1-C6) alkyl group, a lower (C1-C6) alkoxy group etc., or for manufacture of a polymer This is a group derived from the catalyst used.

  Moreover, in each formula of said formula (1)-(3), each repeating unit may exist randomly, may exist alternately, and may form the block individually. .

  In addition, any 1 type may be used for liquid crystalline polyester of Formula (1)-(3), and 2 or more types may be used together by arbitrary combinations and a ratio.

  A woven fabric is used as the shape of the liquid crystalline polymer (B). The liquid crystalline polymer woven fabric is obtained by weaving liquid crystalline polymer fibers into a sheet shape. In the liquid crystalline polymer fiber, the molecular chain of the liquid crystalline polymer is highly oriented in the length direction of the fiber during the melt spinning process. Therefore, in the liquid crystalline polymer woven fabric obtained by weaving the liquid crystalline polymer fiber, The molecules are oriented in the fiber direction, and the molecules are oriented in at least two directions (for example, the warp direction and the weft direction). As the liquid crystalline polymer woven fabric, known products such as commercially available products can be used. Specific examples include 116XC manufactured by Asahi Kasei E-Materials Co., Ltd. (KB Selen fiber, woven with Zexion) and 116VT (woven with Kuraray fiber Vectran), but are not limited thereto. It is not a thing. From the viewpoint of improving the handleability, the lower limit of the thickness of the liquid crystalline polymer (B) woven fabric is usually preferably 1 μm or more, more preferably 3 μm or more, and particularly preferably 5 μm or more. The upper limit of the thickness of the liquid crystalline polymer (B) woven fabric is usually preferably 500 μm or less, more preferably 300 μm or less, more preferably 200 μm or less, and even more preferably 150 μm or less from the viewpoint of thinning the metal-clad laminate.

  The number of the liquid crystalline polymer woven fabrics to be driven is not particularly limited, but a range of 20 / inch (about 7.9 / cm) to 100 / inch (about 39.4 / cm) is preferable. The lower limit of the number of driving is selected from the group consisting of 20, 30, and 40 / inch (about 7.9, 11.8, and 15.7 / cm respectively), and the upper limit of the driving number is 60, Selected from the group consisting of 70, 80, 90, and 100 / inch (approximately 23.6, 27.6, 31.5, 35.4, and 39.4 / cm, respectively) Is done. The number of warps and wefts may be the same as or different from each other as long as the numbers are within the ranges of the numbers described above. Among these, the range of 20 / inch (about 7.9 / cm) to 100 / inch (about 39.4 / cm) is preferable.

  Only one sheet of the liquid crystalline polymer (B) woven fabric may be used for one side of the substrate (A) woven fabric, but it is desirable when it is attached to the woven fabric of the substrate (A). In order to achieve the thickness, two or more woven fabrics of the liquid crystalline polymer (B) may be overlapped and used. When two or more woven fabrics of the liquid crystalline polymer (B) are overlapped, it is preferable to laminate the liquid crystalline polymer (B) so that the fiber directions of the woven fabric are in the same direction from the viewpoint of achieving the desired orientation. .

  The softening point of the liquid crystalline polymer (B) varies depending on the type of the liquid crystalline polymer (B), but is not limited. Specifically, from the viewpoint of heat resistance of the metal-clad laminate, the softening point of the liquid crystalline polymer (B) is usually 200 ° C. or higher, preferably 240 ° C. or higher, and more preferably 260 ° C. or higher. However, from the viewpoint of easy crimping, the softening point of the liquid crystalline polymer is usually 420 ° C. or lower, preferably 400 ° C. or lower, and more preferably 380 ° C. or lower. The softening point of the polymer can be measured by, for example, a thermomechanical analysis (TMA) using a needle probe.

  An inorganic filler may be blended in the liquid crystalline polymer (B). The kneading method is not particularly limited. For example, fibers obtained by mixing and dispersing an inorganic filler in a liquid crystalline polymer resin melt-kneaded by a twin-screw extruder or the like, and forming the resulting composition into a film and a fiber. Or the woven fabric or nonwoven fabric which made the obtained fiber into the sheet form can be used as a liquid crystalline polymer (B) of this invention. Any inorganic filler can be used as long as it is generally used in laminate applications. Specifically, silicas such as natural silica, fused silica, synthetic silica, amorphous silica, hollow silica, molybdenum compounds such as molybdenum oxide and zinc molybdate, zinc borate, zinc stannate, alumina, clay, kaolin, talc , Fired clay, fired kaolin, fired talc, mica, short glass fibers (glass fine powders such as E glass and D glass), and hollow glass. Among these, in the present invention, silicas, talc, and short glass fibers are preferable, and silicas are particularly preferable from the viewpoint of thermal expansion coefficient and dielectric characteristics. These inorganic fillers can be used alone or in combination of two or more.

[Lamination direction of base material (A) woven fabric and liquid crystalline polymer (B) woven fabric]
In the present invention, the base material (A) and the woven cloth of the liquid crystalline polymer (B) are pressure-bonded in a state of being laminated so that the fiber directions of the respective woven cloths are in the same direction. An insulating layer in which the liquid crystalline polymer (B) is attached to A) is formed. Here, the fiber direction of each woven fabric of the base material (A) and the liquid crystalline polymer (B) is “same direction”, and the deviation angle of at least one fiber direction constituting each woven fabric is usually 15 Means less than or equal to degrees. In particular, it is preferably 12 degrees or less, and more preferably 10 degrees or less. It is preferable that the woven fabric of the base material (A) and the woven fabric of the liquid crystalline polymer (B) have the same number of fiber directions and that the crossing angles of the respective fiber directions are also the same. The deviation angles of all the fiber directions of the woven fabrics of (A) and the liquid crystalline polymer (B) are the same.

  Here, the deviation angle in the fiber direction of each woven fabric of the substrate (A) and the liquid crystalline polymer (B) is measured by the following method. That is, in the state where the woven fabric of the base material (A) and the woven fabric of the liquid crystalline polymer (B) are arranged in an overlapping manner, images at the same position are acquired, and the yarn of the woven fabric of the adjacent base material (A) And a straight line having a length of 5 mm is drawn along each of the woven yarns of the liquid crystalline polymer (B), and the straight line obtained along the yarns of the base woven fabric and the yarns of the liquid crystalline polymer woven fabric The angle formed by the obtained straight lines is measured, and this is set as the deviation angle.

[Method for producing metal-clad laminate]
The metal-clad laminate of the present invention is pressure-bonded in a state in which the woven fabric of the base material (A) and the woven fabric of the liquid crystalline polymer (B) are laminated so that the fiber directions of each woven fabric are the same direction. And a manufacturing method including a step of forming an insulating layer.

  Here, the metal foil, the woven fabric of the liquid crystalline polymer (B), and the woven fabric of the base material (A) are bonded together to form an insulating layer, and the insulating layer and the metal layer Can be formed. On the other hand, an insulating layer is formed by pressure bonding in a state where the woven fabric of the base material (A) and the woven fabric of the liquid crystalline polymer (B) are laminated, and then a metal foil is laminated thereon to form a metal layer. You can also do it. Also, a plurality of metal layers and / or insulating layers may be laminated and pressure-bonded, or a plurality of metal-clad laminates may be laminated and pressure-bonded.

  The temperature at the time of pressure bonding may be any temperature as long as at least the liquid crystalline polymer (B) can be attached to the base material (A), but preferably the liquid crystalline polymer (B) is softened. The point is a temperature of −50 ° C. or higher. More preferably, the temperature is a softening point of the liquid crystalline polymer (B) of −40 ° C. or higher. On the other hand, from the viewpoint of maintaining the molecular orientation of the liquid crystalline polymer (B), a temperature of softening point + 100 ° C. or lower is preferable. More preferably, the temperature is the softening point of the liquid crystalline polymer (B) + 70 ° C. or lower, more preferably the softening point + 40 ° C. or lower.

  Moreover, when heating at the time of pressure bonding, the heating temperature is preferably 150 ° C. or higher, particularly 170 ° C. or higher, and more preferably 190 ° C. or higher, from the viewpoint of surely softening the liquid crystalline polymer (B). However, from the viewpoint of protecting the insulating layer, a range of usually 450 ° C. or lower, particularly 430 ° C. or lower, and more preferably 400 ° C. or lower is preferable.

The pressure at the time of pressure bonding is usually 5 kgf / cm ² (about 49 N / cm ² ) or more, particularly 10 kgf / cm ² (about about 5 kgf / cm ² ) from the viewpoint of reliably melting the liquid crystalline polymer (B) and attaching it to the base material (A). 98 N / cm ²⁾ or more, and more preferably to 20 kgf / cm ² (about 196 N / cm ²⁾ or more. However, from the viewpoint of protecting the substrate (A) and the metal foil, it is usually 100 kgf / cm ² (about 980 N / cm ² ) or less, particularly 80 kgf / cm ² (about 784 N / cm ² ) or less, and further 60 kgf / cm. ² (about 588 N / cm ² ) or less is preferable.

  From the viewpoint of reliably melting the liquid crystalline polymer (B) and attaching it to the base material (A), the time for the pressure bonding is usually 5 minutes or longer, preferably 10 minutes or longer, and more preferably 20 minutes or longer. However, from the viewpoint of protecting the base material (A) and the metal foil, it is usually 300 minutes or less, preferably 240 minutes or less, and more preferably 180 minutes or less.

  It is considered that the crystal orientation of the liquid crystalline polymer (B) is completely or partially maintained in the pressure bonding step. Accordingly, when the woven fabric of the liquid crystalline polymer (B) is pressure-bonded to the woven fabric of the base material (A), the shape of the fibers constituting the woven fabric of the liquid crystalline polymer (B) is lost, but the fibers are present. The orientation that has been achieved is fully or partially maintained. For example, in the case of a woven fabric woven with warp and weft, liquid crystal polymer molecules are oriented in two directions, so that the original orientation of the insulating layer obtained by pressure bonding is completely or partially. And substantially coincides with the fiber direction of the woven fabric of the substrate (A). This is presumed to contribute to the reduction of the coefficient of thermal expansion in the plane direction in the insulating layer containing the substrate (A) and the liquid crystalline polymer (B) attached to the substrate (A).

  The metal-clad laminate according to the present invention has a low dielectric constant and dielectric loss tangent, has excellent dielectric properties, and has low thermal expansion in the surface direction. Therefore, the metal-clad laminate according to the present invention is suitable as a printed wiring board material.

[Printed wiring board]
According to another aspect of the present invention, the printed wiring board includes an insulating layer and a metal wiring pattern (conductor layer) formed on the surface of the insulating layer. Also provided is a printed wiring board formed using the metal-clad laminate according to the present invention as a build-up material. Here, the build-up means an operation for producing a printed wiring board having a multilayer structure by repeating drilling, wiring formation, etc. for each layer on a metal-clad laminate.

  When using the metal-clad laminate according to the present invention as a build-up material, for example, after etching the metal foil of the metal-clad laminate by a conventional method, the resin composition layer (insulating layer) is surface-treated by a conventional method. The printed wiring board of the present invention can be obtained by forming a wiring pattern (conductor layer) on the insulating layer surface by plating. Thereby, the insulating layer and metal layer of the metal-clad laminate according to the present invention constitute the insulating layer and metal wiring pattern of the printed wiring board, respectively. The insulating layer thus obtained includes a base material (A) and a liquid crystalline polymer (B) attached to the base material (A). In addition to the metal-clad laminate according to the present invention, other known prepreg, resin sheet, or metal-clad laminate may optionally be used in combination as a build-up material.

  The printed wiring board of the present invention can be a multilayer printed wiring board. For example, after the metal-clad laminate of the present invention is formed, an inner layer circuit is formed thereon, and the resulting circuit is subjected to blackening treatment to obtain an inner layer circuit board. A prepreg or resin sheet is arranged on one or both sides of the inner layer circuit board or metal foil (for example, copper or aluminum) thus obtained, and further metal foil (for example, copper or aluminum) or a release film (polyethylene film). A film formed by applying a release agent on the surface of a polypropylene film, a polycarbonate film, a polyethylene terephthalate film, an ethylene tetrafluoroethylene copolymer film, etc.) is repeatedly laminated and molded as described above. By giving various affirmations, a multilayer printed wiring board is manufactured.

Laminate molding uses a technique generally used for laminate molding of ordinary laminates for printed wiring boards, for example, a multistage press, a multistage vacuum press, a laminator, a vacuum laminator, an autoclave molding machine, etc., and the temperature is, for example, 100 to 400 C., pressure is, for example, 0.1 to 100 kgf / cm ² (about 9.8 kPa to about 38 MPa), and heating time is appropriately selected within a range of, for example, 30 seconds to 5 hours. Moreover, you may postcure at the temperature of 150-400 degreeC, for example as needed, and may adjust a hardening degree.

The present invention will be described in detail below with reference to examples and comparative examples, but the present invention is not limited to these examples.
In the following examples and comparative examples, the deviation angle between the warp and weft of the woven fabric of the substrate (A) and the warp and weft of the woven fabric of the liquid crystalline polymer (B) was confirmed by the following procedure. That is, first, an image at the same position is acquired in a state where the woven fabric of the base material (A) and the woven fabric of the liquid crystalline polymer (B) are arranged to overlap, and the yarns and liquid crystalline properties of the adjacent base material woven fabric are acquired. An angle formed by drawing a straight line having a length of 5 mm along each of the yarns of the polymer woven fabric and the straight line obtained along the yarns of the base woven fabric and the straight line obtained along the yarns of the liquid crystalline polymer woven fabric Was measured as the deviation angle.

Example 1
An E glass cloth (Nittobo E2013) (base material woven fabric) having a thickness of 0.07 mm was used as the base material. A 0.07 mm-thick liquid crystalline polymer woven fabric (116XC manufactured by Asahi Kasei E-Materials) was placed above and below the substrate. The maximum deviation angle between the warp and weft of the base woven fabric and the warp and weft of the liquid crystalline polymer woven fabric was 5 degrees. Further, 18 μm thick electrolytic copper foil is placed on the top and bottom, and a pressure of 40 kgf / cm ² (about 392 N / cm ² ) and a temperature of 350 ° C. are pressed (crimped) for 30 minutes, so that the liquid crystalline polymer is attached to the substrate. A 0.1 mm thick copper clad laminate (metal clad laminate) was obtained.

Example 2
Instead of the liquid crystalline polymer woven fabric used in Example 1, a liquid crystalline polymer woven fabric having a thickness of 0.075 mm (116VT manufactured by Asahi Kasei E-Materials) was used. A copper clad laminate having a thickness of 0.1 mm in which a liquid crystalline polymer was attached to a base material was obtained in the same manner as in Example 1 except that the maximum deviation angle between the warp and the weft was 11 degrees.

Example 3
As a base material, instead of the E glass cloth used in Example 2, a NE glass cloth having a thickness of 0.07 mm (Nittobo NE2013) was used, and the warp and weft of the glass cloth and the warp of the liquid crystalline polymer woven fabric and A copper-clad laminate (metal-clad laminate) having a thickness of 0.1 mm in which a liquid crystalline polymer is attached to a base material is performed in the same manner as in Example 2 except that the maximum deviation angle from the weft is 7 degrees. Obtained.

Example 4
As a base material, instead of the E glass cloth used in Example 3, a T glass cloth having a thickness of 0.07 mm (T2013, manufactured by Nittobo Co., Ltd.) was used. The warp and weft of the glass cloth and the warp of the liquid crystalline polymer woven fabric and A copper-clad laminate (metal-clad laminate) having a thickness of 0.1 mm in which a liquid crystalline polymer is attached to a base material is performed in the same manner as in Example 3 except that the maximum deviation angle from the weft is 3 degrees. Obtained.

Example 5
In place of the liquid crystalline polymer woven fabric used in Example 4, a liquid crystalline polymer woven fabric having a thickness of 0.07 mm (116XC manufactured by Asahi Kasei E-Materials) was used. A copper-clad laminate (metal-clad laminate) having a thickness of 0.1 mm in which a liquid crystalline polymer is attached to a base material by the same operation as in Example 4 except that the maximum deviation angle between the warp and the weft is 4 degrees. )

Comparative Example 1
As the substrate, the same as in Example 1 except that the E glass cloth used in Example 1 was not used and two liquid crystalline polymer films (Kuraray Bexter CT-Z) having a thickness of 0.05 mm were disposed. By operation, a copper clad laminate (metal clad laminate) having a thickness of 0.1 mm was obtained.

Comparative Example 2
An E glass cloth (Nittobo E2013) having a thickness of 0.07 mm was used as a substrate. A liquid crystalline polymer film (Kuraray Bexter CT-Z) having a thickness of 0.05 mm is disposed above and below the substrate, and an 18 μm thick electrolytic copper foil is further disposed above and below the film, and a pressure of 40 kgf / cm ² (about 392 N / cm ² ) at a temperature of 350 ° C. for 30 minutes to obtain a copper-clad laminate (metal-clad laminate) having a thickness of 0.1 mm in which a liquid crystalline polymer is attached to a substrate.

Comparative Example 3
63 parts by weight of a phenol novolac epoxy (DIC EPICRON 770 manufactured by DIC) and 37 parts by weight of a phenol novolak resin (DIC TD2090) were dissolved and mixed with methyl ethyl ketone, and 200 parts by weight of fused silica (FB-3SDC manufactured by Denki Kagaku Kogyo) were mixed. Into this, 0.03 part by weight of 2-ethyl-5-methylimidazole (2E4MZ manufactured by Shikoku Chemicals) was mixed to obtain a varnish. This varnish was diluted with methyl ethyl ketone, impregnated on 0.1 mm thick E glass cloth (Nittobo E2013), and heated and dried at 160 ° C. for 5 minutes to obtain a prepreg having a resin content of 50% by weight. . Next, 18 μm electrolytic copper foil is placed on the top and bottom of one prepreg, pressed at a pressure of 30 kgf / cm ² (about 294 N / cm ² ) and a temperature of 220 ° C. for 120 minutes, and a 0.1 mm thick copper A stretched laminate (metal-clad laminate) was obtained.

Comparative Example 4
A copper-clad laminate (metal-clad laminate) having a thickness of 0.1 mm was obtained in the same manner as in Comparative Example 3 except that the amount of fused silica used was 100 parts by weight.

Measurement and results of physical properties For the copper-clad laminates (metal-clad laminates) obtained in Examples 1 to 5 and Comparative Examples 1 to 4 obtained by the above procedure, the thermal expansion coefficient and the relative dielectric constant are as follows. And the dielectric loss tangent were measured.

-Thermal expansion coefficient: Using a test piece from which the copper foil of the copper clad laminate was removed, the temperature was increased from 40 ° C to 300 ° C at 10 ° C per minute using a thermomechanical analyzer (TA Instruments Q400). The coefficient of thermal expansion (ppm / ° C.) in the plane direction at 60 ° C. to 120 ° C. was measured. The measurement direction was the longitudinal direction (Warp) of the glass cloth (base material) of the copper clad laminate.

Relative permittivity and dielectric loss tangent: Using a test piece from which the copper foil of the copper clad laminate was removed, the relative dielectric constant and dielectric loss tangent of 10 GHz were measured by the cavity resonator perturbation method (Agilent Technology Agilent 8722ES). .

The results obtained are shown in Table 1 below.

  Since the metal-clad laminate according to the present invention has both excellent dielectric properties and low thermal expansion as described above, it is useful as a printed wiring board material, and its industrial practicality is extremely high.

Claims (10)

A metal-clad laminate comprising a base material (A) and an insulating layer containing a liquid crystalline polymer (B) attached to the base material (A), and a metal layer provided on the insulating layer,
The insulating layer is formed by press-bonding the woven fabric of the base material (A) and the woven fabric of the liquid crystalline polymer (B) so that the fiber directions of each woven fabric are in the same direction. A metal-clad laminate. The liquid crystalline polymer (B) has the following formula:

{Wherein x and y each represents an integer}
The metal-clad laminate according to claim 1, having a structure selected from the group consisting of:   The metal-clad laminate according to claim 1 or 2, wherein the substrate (A) is made of glass.   It is a method of manufacturing the metal-clad laminate as described in any one of Claims 1-3, Comprising: The woven fabric of a base material (A) and the woven fabric of a liquid crystalline polymer (B) of each woven fabric are used. A method comprising forming an insulating layer by pressure bonding in a state in which the fibers are laminated in the same direction.   In a state where the woven fabric of the base material (A) and the woven fabric of the liquid crystalline polymer (B) are laminated, the insulating layer is formed and the insulating layer and the metallic layer are laminated by pressing together with the metal foil. The method of claim 4 comprising:   The method according to claim 4, comprising laminating a metal foil on the formed insulating layer to form a metal layer.   The metal-clad laminated board manufactured by the method as described in any one of Claims 4-6.   A method for producing a printed wiring board having a metal wiring pattern provided on an insulating layer, wherein the metal layer is patterned by patterning the metal layer of the metal-clad laminate according to any one of claims 1 to 3 and 7. Forming a wiring pattern.   A printed wiring board manufactured by the method according to claim 8.   A printed wiring board in which a metal wiring pattern is provided on an insulating layer containing a substrate (A) and a liquid crystalline polymer (B) attached to the substrate (A), wherein the insulating layer is the substrate (A) A printed wiring board, which is formed by press-bonding the woven fabric and the woven fabric of the liquid crystalline polymer (B) so that the fiber directions of the woven fabrics are in the same direction.