JP2004338393A - Multilayered resin-metal laminate and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a laminate of an aromatic liquid crystal polyester resin and a metal which shows excellent dimensional stability, does not cause a curl regardless of the shape or size and gives sufficiently large adhesion strength between the metal layer and the resin layer in spite of the thickness of the metal layer and the surface roughness, and to provide its manufacturing method. <P>SOLUTION: The resin-metal laminate has such a structure that a resin layer II is laminated on one surface of the metal layer and further a resin layer I is laminated on the resin layer II. The resin layer I is a filler-containing resin layer composed of an aromatic liquid crystal polyester resin containing 20 to 50% by volume of an inorganic filler, and the resin layer II is a filler-containing resin layer containing 0 to 30% by volume of the inorganic filler, the volume ratio being 10% or more smaller than that of the resin layer I. The multilayered resin-metal laminate is manufactured in this manner. The manufacturing method for the same is also disclosed. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a multilayer resin / metal laminate used for electric / electronic parts and a method for producing the resin / metal laminate, and more particularly to a multilayer laminate of an aromatic liquid crystal polyester resin and a metal thin film.

Conventionally, in the case of ceramic insulating substrates, ceramic capacitor parts, ceramic inductance parts, etc. used in electronic equipment, insulating inorganic powders, dielectric powders, etc. are kneaded together with a binder and a solvent to form a sheet. And sintering at a high temperature to provide substrates, components, and the like.
Since the sintered body obtained by the sintering is sintered at a sintering temperature of 1000 ° C. or more, the characteristics of the dielectric powder often change, and it is difficult to control. In addition, the dielectric properties may be degraded due to the reaction with the added sintering aid, and furthermore, the sintered product has disadvantages such as brittleness. Therefore, a laminate that can be manufactured at a lower temperature has been required.

Therefore, it is widely used to use a high melting point thermoplastic resin such as a polyimide resin in place of ceramics, disperse dielectric powder or the like by a heat-melt kneading method, mold the same with an extruder or the like, and use it for the above purpose. However, in the dispersion of the dielectric substance by the heat-melt kneading method, sintering at a high temperature is not necessary, but it is difficult to uniformly disperse the additive (dielectric substance, etc.) at a high concentration, and the kneaded substance is formed into a sheet. Extrusion molding inevitably generates uneven thickness, pinholes, wrinkles, and the like in the extruded product.
Aromatic liquid crystal polyester resins are also widely used in printed wiring boards, capacitors, etc. because of their excellent heat resistance, moisture absorption resistance, chemical resistance, and electrical properties (low dielectric properties). It has been widely attempted to add various fillers to improve the mechanical properties, dimensional stability, appearance of molded articles, etc. of molded articles. For example, fillers such as zeolite, glass fiber, and anhydrous whisker have been used to improve the physical properties of molded articles. (For example, refer to Patent Documents 1 to 3).
By the way, a film made of a conventional aromatic liquid crystal polyester resin is a film obtained by extruding a molten material by an extrusion method or an inflation method. Had become inferior in nature.
Therefore, a solution casting method has been proposed as a film forming method for improving this point.
For example, an aromatic liquid crystal polyester film formed by a solution casting method and having excellent dimensional stability by containing a filler has been studied. As an aromatic polyester film for a wiring board, an aromatic liquid crystal having a specific composition has been studied. A polyester insulating resin composition has been proposed (for example, see Patent Documents 4 and 5).

This proposal proposes a resin composition capable of producing an insulating resin having a small anisotropy and excellent dimensional stability by adding a filler to a solution obtained by dissolving an aromatic liquid crystal polyester in a specific organic solvent. The present invention proposes a method of forming a film of the resin composition by a casting method to obtain a film having no difference in linear expansion coefficient between the MD direction (winding direction) and the TD direction (direction perpendicular to winding). .
The inventors also disclose in Patent Document 6 a process of applying and drying a solvent mixture of inorganic dielectric fine particles and / or inorganic magnetic fine particles and a liquid crystal polyester on a support. It proposes a sheet manufacturing method.
On the other hand, in recent years, due to the demand for high integration of mounting, wiring boards are becoming thinner and multilayered, and a resin-metal laminate obtained by laminating the heat-resistant resin formed into a film and a metal foil is used for a flexible printed board or the like. It has become widely used. In addition, the shape of the substrate has been diversified and increased in size, and a wiring board conforming to any shape has been required.

The resin-metal laminate is manufactured by a method of fusing the film to a metal foil or bonding the film with an adhesive, or a method of forming the resin composition on a metal foil by a solution casting method. In view of simplification of the process, the latter (film formation on a metal foil by a casting method) is generally used. However, when an aromatic liquid crystal polyester resin was formed into a film on a metal foil by a solution casting method, a phenomenon that the laminate was curled after heat drying and heat treatment occurred.
One of the causes of this phenomenon is the difference in the coefficient of linear expansion between the resin film and the metal foil. Attempts have been made to reduce the difference in coefficients.
The present inventors have also proposed a resin-metal laminate comprising a polyester resin containing a short fibrous inorganic filler and a metal foil in order to prevent the occurrence of the curl (Patent Document 7). However, by adding a filler, the resin layer becomes hard and the adhesion to the metal layer is reduced, so that a metal layer having a small surface unevenness or a use requiring a thinner metal layer is required. In such applications, there has been a problem that the resin layer is separated from the metal layer.

JP-A-5-214217 JP-A-6-57117 JP-A-7-216198 JP-A-2002-114849 JP-A-2002-329422 JP-A-2003-160717 Japanese Patent Application No. 2003-34953

  An object (object) of the present invention is to enable easy molding at a low temperature by a casting method (hereinafter, also referred to as a coating method), excellent dimensional stability, no curling regardless of shape and size, and An object of the present invention is to provide an aromatic liquid crystal polyester resin metal laminate having a sufficiently large adhesive force between a metal layer and a resin layer irrespective of a layer thickness or a surface roughness.

The present inventors have conducted studies to solve the above-described problem, and as a result, in order to prevent curling and to prevent the resin layer and the metal layer from peeling off, separately from the conventional resin layer, in contact with the metal layer. The present inventors have found that it is useful to have another resin layer having a specific composition that contributes to the adhesion between the resin layer and the metal layer, and have completed the present invention.
That is, the present invention is a resin-metal laminate having a structure in which a resin layer II is laminated on one side of a metal layer, and a resin layer I is further laminated on the resin layer II,
The resin layer I is a filler-containing resin layer composed of an aromatic liquid crystal polyester resin containing 20 to 50% by volume of an inorganic filler,
The multilayer resin, wherein the resin layer II is a filler-containing resin layer containing an inorganic filler in a volume fraction of 0% to 30% and a volume fraction of the inorganic filler of the resin layer I which is 10% or less. A metal laminate is provided.
Preferably, the inorganic filler is a short fibrous inorganic filler,
Preferably, there is provided a multilayer resin metal laminate, wherein the short fibrous inorganic filler is a whisker.
Also, the present invention
After forming a layer of a filler-dispersed resin liquid composed of an organic solvent, a resin and an inorganic filler on one surface of the metal layer, the layer of the filler-dispersed resin liquid is dried to laminate the resin layer II on the metal layer, and further the resin On the layer II, a layer of a filler-dispersed resin liquid comprising an organic solvent, an aromatic liquid crystal polyester resin and an inorganic filler is formed on one surface of the metal layer, and then the layer of the filler-dispersed resin liquid is dried to form a resin layer II. A method for producing a resin metal laminate in which a resin layer I is laminated thereon,
The resin layer I is a filler-containing resin layer composed of an aromatic liquid crystal polyester resin containing 20 to 50% by volume of an inorganic filler,
The multilayer resin, wherein the resin layer II is a filler-containing resin layer containing an inorganic filler in a volume fraction of 0% to 30% and a volume fraction of the inorganic filler of the resin layer I which is 10% or less. Provided is a method for manufacturing a metal laminate.

（式中、Ａは水素原子または塩素原子を表わし、ｉは１〜４の整数値を表す。ｉが２以上の場合は複数あるＡは互いに同一であっても異なっていてもよい）で表されるパラ位に塩素原子が置換されたクロロフェノール化合物を４０重量％以上含有する溶剤であることを特徴とする多層樹脂金属積層体の製造方法を提供する。 Preferably, the inorganic filler is a short fibrous inorganic filler,
Preferably, the short fibrous inorganic filler is a whisker,
Preferably, the organic solvent has the following general formula

(In the formula, A represents a hydrogen atom or a chlorine atom, i represents an integer of 1 to 4. When i is 2 or more, a plurality of A may be the same or different.) A solvent containing at least 40% by weight of a chlorophenol compound in which a chlorine atom has been substituted at the para-position.

  The present invention can be easily formed by a coating method at a low temperature without curling regardless of shape and size, and has a sufficient adhesive force between the metal layer and the resin layer regardless of the thickness and surface roughness of the metal layer. This has the effect of providing a large aromatic liquid crystal polyester resin metal laminate.

1. Multilayer resin metal laminate 1-1. Overview The multilayer resin-metal laminate of the present invention is a resin-metal laminate having a structure in which a resin layer II is laminated on one side of a metal layer, and a resin layer I is further laminated on the resin layer II. If necessary, another resin layer other than the resin layer I and the resin layer II may be present.
1-2. Resin layer I
1-2-1. Outline The resin layer I contains at least an aromatic liquid crystal polyester resin (hereinafter, may be simply referred to as a liquid crystal polyester resin) and a short fibrous inorganic filler dispersed in the aromatic liquid crystal polyester resin.

1-2-2. Liquid crystal polyester
1-2-2-1. Kind The above-mentioned liquid crystal polyester is a polyester of a group called a thermotropic liquid crystal polymer exemplified in, for example, JP-A-2002-329422.
For example, (1) one composed of a combination of aromatic dicarboxylic acid, aromatic diol and aromatic hydroxycarboxylic acid, (2) one composed of different kinds of aromatic hydroxycarboxylic acid, (3) aromatic dicarboxylic acid and aromatic And (4) a polyester obtained by reacting an aromatic hydroxycarboxylic acid with a polyester such as polyethylene terephthalate, which forms an anisotropic melt at a temperature of 400 ° C. or lower. . In addition, instead of these aromatic dicarboxylic acids, aromatic diols and aromatic hydroxycarboxylic acids, their ester-forming derivatives may be used.

Examples of the carboxylic acid ester-forming derivatives include, for example, those in which a carboxyl group is a derivative having a high reaction activity such as an acid chloride and an acid anhydride and promoting a reaction to produce a polyester, and a carboxyl group. And a derivative which forms an ester with an alcohol, ethylene glycol, or the like, and generates a polyester by a transesterification reaction. Examples of the ester-forming derivative of the phenolic hydroxyl group include, for example, a derivative in which the phenolic hydroxyl group forms an ester with a carboxylic acid and generates a polyester by a transesterification reaction.
The aromatic dicarboxylic acid, aromatic diol, and aromatic hydroxycarboxylic acid may be substituted with a halogen atom, a methyl group, an ethyl group, an allyl group or the like as long as the ester forming property is not impaired.
The aromatic liquid crystal polyester resin used in the present invention preferably has a composition of 30 to 80 mol% of p-hydroxybenzoic acid, 10 to 35 mol% of hydroquinone and / or 4,4'-dihydroxybiphenyl, terephthalic acid and / or isophthalic acid. It is an aromatic liquid crystal polyester resin comprising 10 to 35 mol% of an acid, and more preferably, the resin is an aromatic liquid crystal polyester resin further containing 5 to 50% of 6,2-hydroxynaphthoic acid.
1-2-2-2. Production Method As a method for synthesizing the aromatic liquid crystal polyester used in the present invention, known methods can be employed. For example, JP-B-47-47870 and JP-B-63-3888 are known. And the like.

1-2-3. Inorganic filler
1-2-3-1. Type Short fibrous inorganic filler The resin layer I of the present invention contains a short fibrous inorganic filler and other inorganic fillers. Examples of the short fiber inorganic filler include aluminum borate, silicon carbide, silicon nitride, potassium titanate, calcium titanate, basic magnesium sulfate, zinc oxide, graphite, magnesia, calcium sulfate, calcium sodium phosphate, magnesium borate, and magnesium borate. Whiskers such as titanium boride, chrysotile, wollastonite; amorphous fibers such as E glass fiber, silica alumina glass fiber, silica glass fiber; tyranno fiber, silicon carbide fiber, zirconia fiber, γ alumina fiber, α alumina Fibers and crystalline fibers such as PAN-based carbon fibers can be used, and are used depending on the application.

Among them, short fibrous inorganic oxide fillers are particularly effective in terms of dispersibility, coefficient of linear expansion, and the like. Examples of inorganic oxides include metal oxides such as silica, alumina, titanium oxide, calcium carbonate, talc, mica, and clay, dolomite, zeolite, silica alumina, wollastonite, potassium titanate, calcium titanate, aluminum borate, and borate. Composite metal oxides such as magnesium oxide and titanium boride can be mentioned. Among them, composite metal oxides, which are composites of two or more oxides, are preferably used because they have physical and electrical properties. For example, aluminum borate and boron oxides such as magnesium borate can be used. A short-fiber composite oxide filler containing a titanium oxide such as a composite oxide containing potassium titanate, calcium titanate, and barium titanate is particularly preferable.
The use contemplated of the environmental stability and surface smoothness, potassium titanate _{(K 2 O · nTiO 2)} , calcium titanate (CaO · nTiO _2), barium titanate (BaO · nTiO _2), magnesium borate A filler made of (Mg ₂ B ₂ O ₅ ) or the like is preferably used, and an aluminum borate (nAl ₂ O ₃ .nB ₂ O ₃ ) filler is particularly preferably used for an insulating substrate or a flexible substrate.
Whiskers are a preferred embodiment among short fibrous fillers. Whiskers mean needle-like single crystals. Among whiskers, boric acid whiskers and titanic acid whiskers are preferably used. In particular, aluminum borate whiskers can be particularly preferably used for insulating substrates and flexible substrates in terms of the coefficient of linear expansion, electrical insulation, and the like.

1-2-3-2. Shape measurement method of short fibrous inorganic filler The number average fiber diameter (D) of the short fibrous filler contained in the resin layer I and the resin layer II of the present invention is 0.05 to 5.0 μm. The number average fiber length (L) is preferably from 1 to 25 μm, more preferably from 5 to 15 μm.
The average aspect ratio (L / D) is preferably from 2 to 80, and more preferably from 3 to 30. If the number average fiber diameter (D) is less than 0.05 μm or the number average fiber length (L) is less than 1 μm, the curling prevention effect is not sufficient, which is not preferable. When the number average fiber diameter (D) exceeds 5 μm, or when the average fiber length (L) exceeds 25 μm, the smoothness of the resin layer is impaired, and uniform dispersion and coating become difficult, which are both undesirable. .
When the average aspect ratio (L / D) is less than 2, the effect of preventing curling is not sufficient, and when the average aspect ratio (L / D) exceeds 80, uniform dispersion becomes difficult and the smoothness of the coating film decreases. Either is not preferred because it impairs.
The shape of the short fibrous inorganic filler present in the resin layer I of the resin metal laminate is measured by dissolving the resin layer I and the resin layer II of a certain area in a solvent, further diluting with a solvent, and settingtle the short fiber. It can be performed by a method such as observing the inorganic filler with a scanning electron microscope.
The surface of the short fibrous filler used in the present invention may be used after being treated with a known coupling agent (for example, a silane coupling agent or a titanate coupling agent).

1-2-3-3. Dispersion state Uniform dispersion In the resin layer I of the multilayer resin-metal laminate of the present invention, the short fibrous inorganic filler is uniformly dispersed in the aromatic liquid crystal polyester resin. In the present invention, "uniformly dispersed" means that the filler is agglomerated or unbalanced when observed with a scanning microscope at about 1000 times from above the resin layer of the resin metal laminate. Refers to a state that is not visually recognized.
Orientation Further, the short fibrous inorganic filler is preferably dispersed in the aromatic liquid crystal polyester resin at a degree of orientation of 1 to 5, more preferably 1 to 3, and particularly preferably 1 to 3. 2.
The above-mentioned degree of orientation expresses the degree to which the above-mentioned many short fibrous inorganic fillers face the same direction, and is a numerical value obtained by the following method. It is desirable that the degree of orientation be smaller.
The surface of the resin layer of the resin metal laminate (the surface of the resin layer I) is observed with a scanning microscope, and the direction of the short fibrous inorganic filler present on the resin surface is measured on the resin surface. An arbitrary direction on the surface of the resin layer is defined as X _0, and an angle (hereinafter, referred to as an inclination angle) between the direction of the short fibrous inorganic filler and the X ₀ axis (hereinafter, referred to as a tilt angle) is 100 randomly selected short fibrous inorganic fillers. The filler is measured in the range of -90 to +90 degrees. Based on the measured data, the horizontal axis indicates the inclination angle, and the vertical axis indicates the inclination angle at which the maximum value of the distribution curve is obtained when the distribution curve is drawn by taking the frequency of the presence of the short fibrous inorganic filler. The direction in which the filler is facing is determined again on the X axis. The number of short fiber fillers whose absolute value of the inclination angle based on the X axis is 0 to 20 degrees is N _0-20, and the number of short fiber inorganic fillers whose absolute value of the inclination angle is 70 to 90 degrees is When N _70-90, to the value obtained by dividing the N _0-20 in the N _70-90 with the degree of orientation. Usually, the direction in which the resin layer is coated in the manufacturing process is the direction of the X axis.

1-2-4. Other Fillers In addition to the short fibrous filler, other fillers can be added to the resin composition of the present invention, if necessary, as long as the properties are not affected. For example, fibrous or acicular reinforcing materials having a number average fiber length other than 1 to 25 μm (in the resin of the resin-metal laminate), such as glass fiber, silica-alumina fiber, alumina fiber, wollastonite, and carbon fiber , Calcium carbonate, dolomite, talc, mica, clay, glass beads, and other inorganic fillers such as TiO ₂ , BaTiO ₃ , PbTiO ₃ , CaTiO ₃ , PZT (PbZrTiO ₃ ), PLZT ((Pb _{1 -X} La _X ) (Zr-Tr)), inorganic dielectric particles, such as LiNbO _3, for example, Fe-Ni type, Fe-Y type, Fe-Al over Si type, Fe over Ni over Co-based, Ba ferrite, Co ferrite, Inorganic magnetic particles, such as Mg-based ferrite and Ni-Zn-based ferrite, can be used. Preferably the addition of the body particles or inorganic magnetic particles, especially when increasing the dielectric properties of the resin layer, titanium oxide, titanate metal salts.
The addition amount of the filler other than the short fibrous filler is not more than 80% by volume fraction, preferably not more than 50%, particularly preferably more than 30%, based on the total amount of the filler and the short fibrous filler. There must be no quantity. If the proportion of the filler other than the short fiber is too large, the strength is improved, but the curl preventing effect cannot be obtained.

1-2-5. Compounding amount The total compounding amount of the short fibrous filler and other filler to be mixed in the resin layer I is preferably 20 to 50% by volume fraction with respect to the entire resin layer I (resin + filler). From the viewpoint of the balance between curling prevention and brittleness reduction, 25 to 45% is more preferable, and 30 to 40% is further preferable. If the amount is less than 20%, the effect of preventing curling is not sufficient, and if it is more than 50%, the obtained resin layer becomes brittle, which is not preferable. In order to sufficiently exhibit the characteristics of the present invention, it is necessary that the short fibrous filler be contained in at least 10% of the entire resin layer (resin + filler).
Also, if necessary, colorants such as dyes and pigments, mold release improvers such as fluororesins, coupling agents, leveling agents, defoamers, ultraviolet absorbers, flame retardants, antioxidants, heat stable One or more kinds of usual additives such as an agent, an antistatic agent and a surfactant can be added.

1-2-6. Shape of Resin Layer I The thickness of the resin layer I of the present invention varies depending on its use, but is generally 10 to 100 μm.

1-3. Resin layer II
1-3-1. Outline The laminate of the present invention has a resin layer II in contact with a metal layer.
1-3-2. resin
1-3-2-1. Type The resin layer II of the present invention is preferably a resin that can be bonded to the resin layer I and the metal layer and has high heat resistance. As such a resin, for example, a liquid crystal polyester resin, a polyimide resin, a polyether sulfone resin (PES), a polyether ketone resin (PEEK) and the like can be used, and a liquid crystal polyester resin and a polyimide resin are preferably used. You. In particular, the same liquid crystal polyester resin as that of the resin layer I can be most preferably used.
The resin of the resin layer I and the resin of the resin layer II may be different resins. However, considering the adhesion strength at the resin interface, it is preferable that the resins are composed of the same monomer. It is particularly preferred that there is.

1-3-3. Inorganic filler
1-3-3-1. Kind When a filler is used for the resin layer II of the present invention, the same filler as that used for the resin layer I can be used, but a fibrous filler is particularly preferable. Examples of the filler include potassium titanate, calcium titanate, barium titanate, aluminum borate, and magnesium borate, and preferably potassium titanate and aluminum borate.
1-3-3-2. Blending Amount of the inorganic filler blended in the resin layer II is preferably 0 to 30% by volume fraction based on the whole resin layer II (resin + filler), and from the viewpoint of adhesion strength to the metal layer. To 0 to 20% is more preferable, and 0 to 10% is still more preferable. In consideration of the balance between the adhesive strength and the curl of the laminate, the amount of the short fibrous filler to be blended in the resin layer II needs to be at least 10% less than the amount of the filler to be blended in the resin layer I.

1-3-4. Shape of Resin Layer II Since the resin layer II serves as an adhesive layer with metal, it is preferable to reduce the filler and reduce the film thickness so as not to affect the curl and improve the peel strength. When it is necessary to increase the film thickness (for example, when it is desired to obtain a thick film with as few coatings as possible), it is necessary to increase the film thickness of the resin layer II, in which case the peel strength does not decrease significantly. Preferably, an amount of filler is added.
The thickness of the resin layer II of the present invention varies depending on its use, but is generally 1 to 30 μm.

1-3-5. Other Resin Layer In the multilayer resin metal laminate of the present invention, another resin layer made of a liquid crystal polyester resin may further be present on the resin layer I as necessary. The resin layer plays a role of adjusting the curl when the circuit is formed by etching the metal layer.
The resin and filler of the resin layer are preferably the same as those of the resin layer I, and the amount of the filler may be the same as that of the resin layer II. The thickness is determined according to the level of curl correction after circuit formation. The thickness is preferably 1 to 30 μm.

1-4. Metal layer The metal layer of the present invention may use an optimum material according to its use.For example, gold, platinum, silver, copper, nickel, chromium, tin, zinc, lead, rhodium, palladium, cobalt, etc. are used. Gold, silver, copper, nickel and aluminum are preferred from the viewpoint of electrical characteristics and the like, and copper is most preferably used in consideration of economy and the like.
The method for producing the copper layer is not particularly limited, but an electrolytic copper foil or a rolled copper foil having a thickness of 6 to 35 μm, preferably 9 to 18 μm can be preferably used. The peel strength of the laminate is affected by the thickness of the copper foil, and the adhesive strength (peel strength) can be increased as the thickness of the copper foil increases.
In order to cope with higher frequencies, the surface roughness of the metal foil (copper foil) is preferably small, and Rz is preferably 10 μm or less, more preferably 5 μm or less, from the viewpoint that attenuation and delay of high-frequency signals hardly occur. It is 3 μm or less.

2. Production method 2-1. Outline The resin-metal laminate having a three-layer structure of the present invention is manufactured by first forming a resin layer II on a metal layer by a solution coating method, and then forming a resin layer I on the resin layer II. Specifically, after forming a layer of a filler-dispersed resin liquid composed of an organic solvent, a resin and an inorganic filler on one surface of the metal layer, the resin layer II is formed on the metal layer by drying the layer of the filler-dispersed resin liquid. After laminating and further forming a layer of a filler-dispersed resin liquid comprising an organic solvent, an aromatic liquid crystal polyester resin and an inorganic filler on one side of the metal layer on the resin layer II, the layer of the filler-dispersed resin liquid is dried. Thereby, the resin layer I is laminated on the resin layer II.
The individual manufacturing methods of the resin layer I and the resin layer II are as follows:
1) a step of producing a filler-dispersed resin liquid containing an organic solvent, an aromatic liquid crystal polyester resin, and an inorganic filler; (2) a step of forming a layer of the filler-dispersed resin liquid on the surface to be coated; and (3) the surface to be coated. Drying the layer of the filler dispersion formed in the step (c). In the case of manufacturing the resin layer II, the surface to be coated is a metal layer, and in the case of the resin layer I, the surface to be coated is the resin layer II. Further, it is preferable to provide a (4) heat treatment step after the above (3) step.

（式中、Ａは水素原子または塩素原子を表わし、ｉは１〜４の整数値を表す。ｉが２以上の場合は複数あるＡは互いに同一であっても異なっていてもよい）で表されるようなパラ位に塩素原子が置換されたクロロフェノール化合物を６０重量％以上含有する溶剤であり、ｐ−クロロフェノール、２，４−ジクロロフェノール、３，４−ジクロロフェノール、２，４，５−トリクロロフェノール、２，４，６−トリクロロフェノール、ペンタクロロフェノール等が挙げられ、入手性、作業性、コスト等の点から、ｐ−ヒドロキシフェノールを４０重量％以上が好ましく、更に好ましくは７０重量％以上である。
前記溶剤と混合して使用される溶媒としては、溶解性を妨げない点から、ｏ- ジクロロベンゼン、クロロホルム、塩化メチレン、テトラクロロエタン等が好
ましい。 2-2. Manufacturing process of filler-dispersed resin liquid 2-2-1. Overview The production of the filler-dispersed resin liquid may be such that the aromatic liquid crystal polyester resin and the inorganic filler and the like may be simultaneously dissolved in the solution.However, the aromatic liquid crystal polyester resin can be easily and completely dissolved, preferably. After dissolving the aromatic liquid crystal polyester resin in a solvent to obtain a resin solution, it is preferable to add a short fibrous inorganic filler or the like to the resin solution to obtain a filler-dispersed resin liquid.
2-2-2. solvent
Kind and Addition The solvent used for dissolving the resin or the aromatic liquid crystal polyester of the present invention is not particularly limited as long as it is a solvent capable of dissolving the liquid crystal polymer and casting and forming a film.

(In the formula, A represents a hydrogen atom or a chlorine atom, i represents an integer of 1 to 4. When i is 2 or more, a plurality of A may be the same or different.) A solvent containing at least 60% by weight of a chlorophenol compound in which a chlorine atom is substituted at the para position, such as p-chlorophenol, 2,4-dichlorophenol, 3,4-dichlorophenol, 2,4, Examples thereof include 5-trichlorophenol, 2,4,6-trichlorophenol, and pentachlorophenol. From the viewpoints of availability, workability, cost, and the like, p-hydroxyphenol is preferably 40% by weight or more, and more preferably 70% by weight. % By weight or more.
As a solvent used by mixing with the above-mentioned solvent, o-dichlorobenzene, chloroform, methylene chloride, tetrachloroethane and the like are preferable from the viewpoint of not hindering solubility.

2-2-3. Resin Dissolution When the resin forming the resin layer I or the resin layer II is dissolved in a solvent, the amount of the resin added to the solvent is 0.5 to 30% by weight as a resin component within a range in which the resin is dissolved. It is preferably added in a proportion, more preferably from 1 to 20% by weight, and more preferably from 3 to 10% by weight, from the viewpoint of workability or economy. preferable. If it is less than 0.5% by weight, the production efficiency tends to decrease, and if it exceeds 30% by weight, it takes a long time to dissolve. The dissolving method is not particularly limited, but it is preferable to dissolve by stirring in an appropriate temperature range in consideration of the boiling point and the melting point of the solvent.

2-2-4. Filler dispersion
Filler original shape
Filler final shape Next, the solution in which the resin is dissolved, if necessary, is filtered with a filter or the like, and after removing fine foreign substances contained in the solution, it is preferable to add a filler to obtain a filler-dispersed resin liquid. .
The short fibrous inorganic filler to be added to the resin solution may be broken during compounding, so that the shape of the short fibrous inorganic filler present in the resin layer in the finally obtained resin-metal laminate is somewhat larger. Long ones are preferred. The number average fiber length of the short fibrous inorganic filler added to the resin solution is preferably 1 to 30 μm, more preferably 5 to 25 μm.
In the case of the resin layer I, the amount of the filler is preferably 20 to 50% by volume fraction based on the entire resin layer I (resin + filler), and from the viewpoint of the balance between curling prevention and brittleness reduction. The amount which becomes 25-45% is more preferable, and the amount which becomes 30-40% is more preferable. In the case of the resin layer II, the volume fraction is preferably 0 to 30% with respect to the entire resin layer II (resin + filler), more preferably 0 to 20% from the viewpoint of the adhesion strength to the metal layer. 10% is more preferred.
The solid content of the filler-dispersed resin liquid is 5 to 35%, preferably about 10 to 30%.

2-2-5. Filler dispersion liquid properties The viscosity of the filler dispersion liquid is 1,000 to 30,000 mP · s, preferably 2,000 to 20,000 mP · s, particularly preferably 3,000 to 10,000 mP · s. If the viscosity is less than 1000 mP · s, the dispersion liquid after coating has a large flow, and it is not preferable because a predetermined film thickness cannot be obtained or an uneven film thickness is obtained. It is not preferable because the filler is broken due to excessive shearing or the filler is oriented at the time of coating, so that the curl preventing effect cannot be sufficiently exhibited. Since the dispersion / coating in the above viscosity range has a great influence on the orientation and the dispersion state of the filler, the dispersion / coating is performed in accordance with the cooling conditions and the dispersion speed of the apparatus so that the dispersion maintains the above viscosity range. It is particularly preferable to adjust the temperature appropriately.

2-3. Forming process of resin liquid layer
Forming method As a method of forming a layer of the filler-dispersed resin liquid on the surface to be coated, coating the layer of the filler-dispersed resin liquid with a doctor blade, coating with a comma coater, roller coating, spray coating, spinner coating Method, curtain coating method, slot coating method, screen coating method, etc., may be formed on one side of the metal layer by any method, but coating with a doctor blade or coating with a comma coater in that a stable film thickness can be obtained. It is preferable to form by the method of.

2-4. Drying process
The drying method is not particularly limited, but it is preferable to continuously dry while forming the layer of the filler-dispersed resin liquid on the surface to be coated.
In this case, the coating liquid is continuously applied by a coating machine while the surface to be coated wound on a roll is being fed. In order to prevent contamination of impurities, coating is preferably performed in a clean atmosphere. Particularly for electronic parts, the coating is performed in an atmosphere having a clean degree of class 10000 or less, preferably class 1000 or less, and particularly preferably class 100 or less. It is good to work.
As a method for removing the solvent from the coated dispersion, a commonly known drying method may be used, and a method in which the solvent is continuously evaporated while forming a film with a casting coating machine is efficient. Heat drying, reduced pressure drying, ventilation drying, and the like can be mentioned. Among them, it is preferable to perform heating drying from the viewpoint of production efficiency and handleability, and it is more preferable to heat and dry while ventilating. Although drying under reduced pressure is possible, it becomes difficult to seal the apparatus and recover the solvent.

The completion of drying is determined based on the remaining amount of the solvent in the resin layer. The remaining amount of the solvent in the resin layer is preferably 5% by weight or less, more preferably 3% by weight or less, and particularly preferably 1% by weight or less. The drying conditions vary depending on the drying method. However, if the temperature is too low, drying takes a long time and the productivity is poor, which is not preferable. If the temperature is too high, appearance defects such as foaming occur, which is not preferable. Drying can be adjusted by a drying time at a constant temperature, but in order to prevent curling, drying may be performed stepwise at several temperatures.
The metal foil used as the metal layer of the present invention may use the metal foil as it is, or may use a composite metal foil laminate in which a metal foil and a back film are laminated with a film or the like as a reinforcing material on the back. it can. By adding a release adjuster or the like to the coated surface as needed, the back film can be smoothly and continuously released from the laminate.

2-5. Heat treatment process
After removing the solvent, the resin-metal laminate is subjected to heat treatment at 250 ° C. to 400 ° C. for 20 to 180 minutes, preferably at 280 ° C. to 350 ° C. for 30 to 80 minutes. By this heat treatment, the residual solvent in the drying step is volatilized, and at the same time, crystallization occurs and the properties of the resin are exhibited. The short fibrous filler of the present invention can minimize the volume shrinkage during the drying and heat treatment steps.
When applying another resin layer with a multilayer laminate of four or more layers, the resin may be applied, dried and laminated according to the above-described procedure.

3. Characteristics The multilayer resin metal laminate obtained in this way is easily formed by a coating method at low temperature, has excellent dimensional stability, has no peeling trouble regardless of the shape and thickness of the metal layer, and has no curl. This is a resin-metal laminate with no occurrence.
Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to the following examples.

[Example 1]
Mixing of resin layer II 46 g of parachlorophenol (manufactured by Inui Corporation) and 1 1.5 g of o-dichlorobenzene (manufactured by Kureha Chemical Co., Ltd.) were added to 5 g of an aromatic liquid crystal polyester resin (Sumika Super LCP manufactured by Sumitomo Chemical Co., Ltd.). The mixture was stirred at 130 ° C. for 6 hours to obtain a resin solution having a viscosity of 4200 mps. 1.2 g of aluminum borate whisker (trade name: Arbolex M20, manufactured by Shikoku Chemicals Co., Ltd.) was added to the resin solution and dispersed with a disper, and a filler-dispersed resin solution having a viscosity of 4600 mp · s and a solid content of 9.7% was added. Got. The aluminum borate whisker has an average fiber length of 20 μm, an average fiber diameter of 0.8 μm, and an aspect ratio of 25.
Coating and Drying of Resin Layer II The resin solution is doctored on an electrolytic copper foil (F2-WS, manufactured by Furukawa Circuit Foil Co., Ltd.) having a length of 30 cm × 20 cm, a thickness of 12 μm, and a surface roughness (Rz) of 1.7 μm. Using a blade, the film was cast-coated so that the dry film thickness became 5 μm, and dried by a hot air circulation type dryer at 120 ° C. × 5 minutes → 160 ° C. × 5 minutes.
The volume fraction of the resin component of the obtained resin-metal laminate resin layer was 90%, and the volume fraction of the aluminum borate whisker was 10%.

Mixing of resin layer I 46 g of parachlorophenol (manufactured by Inui Corporation) and 1 1.5 g of o-dichlorobenzene (manufactured by Kureha Chemical Co., Ltd.) were added to 5 g of an aromatic liquid crystal polyester resin (Sumika Super LCP manufactured by Sumitomo Chemical Co., Ltd.). The mixture was stirred at 130 ° C. for 6 hours to obtain a resin solution having a viscosity of 4200 mps. 5.1 g of aluminum borate whisker (trade name: Arbolex M20, manufactured by Shikoku Chemicals Co., Ltd.) was added to the resin solution and dispersed with a disper, and a filler-dispersed resin solution having a viscosity of 6800 mp · s and a solid content of 14.8% was added. Got.

Coating and Drying of Resin Layer I The filler-dispersed resin liquid was applied to the electrolytic copper foil (Furukawa Circuit Foil Co., Ltd .: F2-WS) using a doctor blade so that the Dry film thickness was 50 μm on the resin layer II. It was cast coated and dried in a hot air circulating drier in three stages of 120 ° C. × 5 minutes → 140 ° C. × 5 minutes → 160 ° C. × 5 minutes.
After confirming that the residual ratio of the solvent was 1%, a heat treatment was performed at 300 ° C. × 60 minutes in a dryer in a nitrogen atmosphere. The volume fraction of the resin component of the obtained resin-metal laminate resin layer was 68%, and the volume fraction of the aluminum borate whisker was 32%. Physical properties of the resin-metal laminate were as shown in Table 2.

The above physical properties were measured by the following method (1) Adhesion (linear expansion coefficient)
Using a resin copper foil laminate that had been subjected to the heat treatment step, copper was etched with a ferric chloride solution, and the resulting film was heated to 250 ° C. by a thermal mechanical analyzer (TMA SS6000) manufactured by Seiko Instruments Inc. After cooling at 5 ° C./min, the average coefficient of linear expansion from 240 ° C. to 100 ° C. was calculated and determined.

(2) Peel strength (adhesiveness)
The measurement was performed according to JIS C6481. Using a tensile tester, the resin side of the resin copper foil laminate having a width of 10 mm was fixed to an aluminum plate with a double-sided tape, and the copper foil was peeled off in a 90 ° direction at a speed of 50 mm / min.
◎: 0.7 kg / cm or more Sufficient adhesive strength.
：: 0.5 to 0.7 kg / cm Adhesive force that can be practically used.
Δ: 0.3 to 0.5 kg / cm, which may be insufficient for practical use X: 0.3 kg / cm or less, not practical.
(3) Curl The resin copper foil laminate that had been subjected to the heat treatment step was cut out to a size of 10 cm × 10 cm, placed on a horizontal surface, and the state of the curl was visually observed, and judged according to the following criteria.
：: Almost no curl was observed.
：: Slight curl is observed.
Δ: Slightly large curl.
X: The curl is large and cylindrical.

[Example 2]
As a resin layer I, 46 g of parachlorophenol (manufactured by Inui Corporation) and 11.5 g of o-dichlorobenzene (manufactured by Kureha Chemical Co., Ltd.) were added to 5 g of an aromatic liquid crystal polyester resin (Sumika Super LCP manufactured by Sumitomo Chemical Co., Ltd.), and added to the mixture. The resulting mixture was stirred at a temperature of 6 ° C. for 6 hours to obtain a resin solution having a viscosity of 4,200 mps. Also, 46 g of parachlorophenol (manufactured by Inui Corporation) and 11.5 g of o-dichlorobenzene (manufactured by Kureha Chemical Co., Ltd.) were added to 5 g of an aromatic liquid crystal polyester resin (Sumika Super LCP manufactured by Sumitomo Chemical Co., Ltd.) as Resin II, The mixture was stirred at 130 ° C. for 6 hours to obtain a resin solution having a viscosity of 4,200 mp · s, and 4.7 g of aluminum borate whisker (trade name: Albolex M20, manufactured by Shikoku Chemicals Co., Ltd.) was added to the resin solution. Except for this, the multilayer resin metal laminate was manufactured in the same manner as in Example 1.
[Example 3]
As a resin layer II, 46 g of parachlorophenol (manufactured by Inui Corporation) and 11.5 g of o-dichlorobenzene (manufactured by Kureha Chemical Co., Ltd.) were added to 5 g of an aromatic liquid crystal polyester resin (SUMIKASUPER LCP manufactured by Sumitomo Chemical Co., Ltd.), and the resulting mixture was added to the mixture. A multilayer resin-metal laminate was manufactured in the same manner as in Example 1 except that a resin solution having a viscosity of 4200 mps was stirred at 6 ° C. for 6 hours. The obtained resin-metal laminate is as shown in Table 1, and its physical property values are as shown in Table 2.

[Example 4]
As shown in Table 1, as resin layer I, 46 g of parachlorophenol (manufactured by Inui Corporation) and 46 g of o-dichlorobenzene (manufactured by Kureha Chemical Co., Ltd.) were added to 5 g of an aromatic liquid crystal polyester resin (Sumika Super LCP manufactured by Sumitomo Chemical Co., Ltd.). 11.5 g was added, and the mixture was stirred at 130 ° C. for 6 hours to obtain a resin solution having a viscosity of 4200 mp · s, and 1.2 g of aluminum borate whisker (trade name: Albolex M20, manufactured by Shikoku Chemicals Co., Ltd.) and an average particle diameter of 5 μm A multilayer resin metal laminate was manufactured in the same manner as in Example 1, except that 5.3 g of spherical barium titanate was used. Physical properties of the obtained resin-metal laminate are as shown in Table 2.
[Example 5]
As a resin layer II, 2.4 g of aluminum borate whisker (manufactured by Shikoku Kasei Kogyo Co., Ltd .: trade name: Albolex M20) was added to 58.8 g of polyimide varnish ("U-varnish" manufactured by Ube Industries, Ltd.) and dispersed. The resin solution was dispersed to obtain a filler-dispersed resin solution. The resin solution was placed on an electrolytic copper foil (F2-WS, manufactured by Furukawa Circuit Wheel Co., Ltd.) having a length of 30 cm × a width of 20 cm, a thickness of 12 μm, and a surface roughness (Rz) of 1.7 μm. The coating was performed using a doctor blade so that the dry film thickness was 5 μm, and the drying heat treatment was performed using a hot-air circulation dryer at 100 ° C. × 10 minutes → 200 ° C. × 10 minutes → 350 ° C. × 10 minutes. A multilayer resin-metal laminate was produced in the same manner as in Example 1. The obtained resin-metal laminate is as shown in Table 1, and its physical property values are as shown in Table 2.

[Comparative Example 1]
A multilayer resin-metal laminate was manufactured in the same manner as in Example 1 except that the resin layer II was not provided. The obtained resin-metal laminate is as shown in Table 1, and its physical property values are as shown in Table 2.
[Comparative Example 2]
A multilayer resin-metal laminate was manufactured in the same manner as in Example 1 except that the resin having the same composition as the resin layer I of Example 1 was used as the resin layer II. The obtained resin-metal laminate is as shown in Table 1, and its physical property values are as shown in Table 2.
[Comparative Example 3]
As a resin layer II, 46 g of parachlorophenol (manufactured by Inui Corporation) and 11.5 g of o-dichlorobenzene (manufactured by Kureha Chemical Co., Ltd.) were added to 5 g of an aromatic liquid crystal polyester resin (Sumika Super LCP manufactured by Sumitomo Chemical Co., Ltd.), and 130 Stirring at 6 ° C. for 6 hours to obtain a resin solution having a viscosity of 4200 mps. Example 1 was repeated except that a resin containing 7.3 g of aluminum borate whisker (trade name: Alvolex M20, manufactured by Shikoku Chemicals Co., Ltd.) was used. In the same manner as in the above, a multilayer resin metal laminate was manufactured. The obtained resin-metal laminate is as shown in Table 1, and its physical property values are as shown in Table 2.

[Comparative Example 4]
As a resin layer I, 46 g of parachlorophenol (manufactured by Inui Corporation) and 11.5 g of o-dichlorobenzene (manufactured by Kureha Chemical Co., Ltd.) were added to 5 g of an aromatic liquid crystal polyester resin (Sumika Super LCP manufactured by Sumitomo Chemical Co., Ltd.), and added to the mixture. Stirring at 6 ° C. for 6 hours to obtain a resin solution having a viscosity of 4200 mp · s, and using a resin to which 1.9 g of aluminum borate whisker (trade name: Albolex M20, manufactured by Shikoku Chemicals Co., Ltd.) was added. In the same manner as in the above, a multilayer resin metal laminate was manufactured. The obtained resin-metal laminate is as shown in Table 1, and its physical property values are as shown in Table 2.

The aromatic liquid crystal polyester resin metal laminate of the present invention is suitably used particularly in the fields of multilayer printed wiring boards, capacitors and the like.

Claims (18)

A resin-metal laminate having a structure in which a resin layer II is laminated on one surface of a metal layer and a resin layer I is further laminated on the resin layer II,
The resin layer I is a filler-containing resin layer composed of an aromatic liquid crystal polyester resin containing 20 to 50% by volume of an inorganic filler,
The multilayer resin, wherein the resin layer II is a filler-containing resin layer containing an inorganic filler in a volume fraction of 0% to 30% and a volume fraction of the inorganic filler of the resin layer I which is 10% or less. Metal laminate.   2. The multilayer resin metal laminate according to claim 1, wherein the inorganic filler is a short fiber inorganic filler.   3. The multilayer resin metal laminate according to claim 1, wherein the short fibrous inorganic filler is a whisker.   The number average fiber length of the short fibrous inorganic fillers contained in the resin layer I and the resin layer II is 1 to 25 μm, the number average fiber diameter is 0.05 to 5.0 μm, and the aspect ratio is 2 to 80. The multilayer resin metal laminate according to claim 1, wherein:   The multilayer resin metal laminate according to any one of claims 1 to 4, wherein the short fibrous inorganic filler in the resin layer I is uniformly dispersed with a degree of orientation of 1 to 5 in the resin layer. body.   The multilayer resin metal laminate according to any one of claims 1 to 5, wherein the resins of the resin layer I and the resin layer II are the same kind of aromatic liquid crystal polyester resin.   Aromatic liquid crystal polyester in which the aromatic liquid crystal polyester resin is composed of 30 to 80 mol% of p-hydroxybenzoic acid, 10 to 35 mol% of hydroquinone and / or 4,4'-dihydroxybiphenyl, and 10 to 35 mol% of terephthalic acid and / or isophthalic acid. The multilayer resin-metal laminate according to any one of claims 1 to 6, which is a resin.   The resin metal laminate according to claim 7, wherein the aromatic liquid crystal polyester resin further contains 5 to 50 mol% of 6,2-hydroxynaphthoic acid.   The multilayer resin metal laminate according to any one of claims 1 to 8, wherein the metal layer is a metal foil mainly composed of copper. After forming a layer of a filler-dispersed resin liquid composed of an organic solvent, a resin and an inorganic filler on one surface of the metal layer, the layer of the filler-dispersed resin liquid is dried to laminate the resin layer II on the metal layer, and further the resin After forming a layer of a filler-dispersed resin liquid comprising an organic solvent, an aromatic liquid crystal polyester resin and an inorganic filler on the layer II, the layer of the filler-dispersed resin liquid is dried to form a resin layer I on the resin layer II. A method of manufacturing a resin metal laminate for laminating,
The resin layer I is a filler-containing resin layer composed of an aromatic liquid crystal polyester resin containing 20 to 50% by volume of an inorganic filler,
The multilayer resin, wherein the resin layer II is a filler-containing resin layer containing an inorganic filler in a volume fraction of 0% to 30% and a volume fraction of the inorganic filler of the resin layer I which is 10% or less. A method for manufacturing a metal laminate.   The method for producing a multilayer resin-metal laminate according to claim 10, wherein the inorganic filler is a short fiber inorganic filler.   The method for producing a multilayer resin-metal laminate according to claim 10, wherein the short fibrous inorganic filler is a whisker.   The number average fiber length of the short fibrous inorganic fillers contained in the resin layer I and the resin layer II is 1 to 25 μm, the number average fiber diameter is 0.05 to 5.0 μm, and the aspect ratio is 2 to 80. The method for producing a multilayer resin-metal laminate according to any one of claims 10 to 12, wherein: The organic solvent has the following general formula

(In the formula, A represents a hydrogen atom or a chlorine atom, i represents an integer of 1 to 4. When i is 2 or more, a plurality of A may be the same or different.) The method for producing a resin-metal laminate according to any one of claims 10 to 13, wherein the solvent is a solvent containing 40% by weight or more of a chlorophenol compound in which a chlorine atom is substituted at the para-position.   The method for producing a multilayer resin-metal laminate according to any one of claims 10 to 14, wherein the resins of the resin layer I and the resin layer II are the same kind of aromatic liquid crystal polyester resin.   Aromatic liquid crystal polyester in which the aromatic liquid crystal polyester resin is composed of 30 to 80 mol% of p-hydroxybenzoic acid, 10 to 35 mol% of hydroquinone and / or 4,4'-dihydroxybiphenyl, and 10 to 35 mol% of terephthalic acid and / or isophthalic acid. The method for producing a multilayer resin metal laminate according to any one of claims 10 to 15, which is a resin.   The method according to claim 16, wherein the aromatic liquid crystal polyester resin further contains 5 to 50 mol% of 6,2-hydroxynaphthoic acid. The method according to any one of claims 10 to 17, wherein the metal layer is a metal foil mainly composed of copper.