JP2018029187A - Laminated plate and metal base circuit board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated plate having an excellent adhesion with an insulating layer and a copper foil and forms a metal base circuit board with an excellent heat radiation property of the insulating layer.SOLUTION: The laminated plate includes: a metal plate; an insulating layer on the metal plate containing liquid crystal polyester; and a copper foil on the insulating layer. The laminated plate has a ten-point average roughness of 10 μm or larger with the face of the copper foil in contact with the insulating layer. The liquid crystalline polyester desirably has a repeating unit expressed by the following formula (1), a repeating unit expressed by the following formula (2), and a repeating unit expressed by the following formula (3): (1) -O-Ar-CO-; (2) -CO-Ar-CO-; and (3) -X-Ar-Y-. (Ardenotes a phenylene group, a naphthylene group, or a biphenylene group. Arand Arindependently denote a phenylene group, a naphthylene group, a biphenylene group, or a group expressed by the following formula (4). X and Y independently denote an oxygen atom or an imino group.)SELECTED DRAWING: None

Description

  The present invention relates to a laminated board and a metal base circuit board using the laminated board.

  In recent years, with the miniaturization, high performance, and high power of electric / electronic devices, circuit boards are required to easily dissipate heat generated from mounted elements, that is, excellent in heat dissipation. . As a circuit board capable of meeting this requirement, a metal base circuit board having a metal plate, an insulating layer provided thereon, and a circuit pattern provided thereon has been studied. This metal base circuit board is obtained by patterning a copper foil from a laminated board having a metal plate, an insulating layer provided thereon, and a copper foil provided thereon. And since it is excellent in heat resistance and dielectric loss is small as the said insulating layer, the insulating layer containing liquid crystalline polyester is examined (patent documents 1-5).

International Publication No. 2010/117033 JP 2011-077270 A JP 2011-181833 A JP 2011-219749 A JP 2011-249606 A

  The conventional metal base circuit board does not necessarily have sufficient adhesion between the insulating layer and the copper foil. For this reason, copper foil may be easy to peel from an insulating layer. Further, the conventional metal base circuit board does not necessarily have sufficient heat dissipation of the insulating layer. Therefore, an object of the present invention is to provide a laminate that provides a metal base circuit board that has excellent adhesion between an insulating layer and a copper foil and that has excellent heat dissipation of the insulating layer.

  To achieve the above object, the present invention is a laminated plate comprising a metal plate, an insulating layer provided on the metal plate and containing liquid crystal polyester, and a copper foil provided on the insulating layer, Provided is a laminate in which the ten-point average roughness of the surface of the copper foil in contact with the insulating layer is 10 μm or more. Moreover, according to this invention, the metal base circuit board formed by patterning the said copper foil of the said laminated board is also provided.

  The laminate of the present invention is excellent in adhesion between the insulating layer and the copper foil, and excellent in heat dissipation of the insulating layer, so by patterning the copper foil, the adhesion between the insulating layer and the copper foil is excellent, It is possible to obtain a metal base circuit board excellent in heat dissipation of the insulating layer.

  The laminated board of this invention is a laminated board which has a metal plate, the insulating layer provided on it, and the copper foil provided on it.

Examples of the material of the metal plate include aluminum, iron, and copper, and may be an alloy such as an aluminum alloy or stainless steel. The metal plate may contain a nonmetal such as carbon, and may contain, for example, aluminum combined with carbon. The metal plate preferably has a high thermal conductivity, and the thermal conductivity is preferably 60 W · m ⁻¹ · K ⁻¹ or more.

  The thickness of the metal plate is usually 0.2 to 5 mm. The metal plate may have flexibility or may not have flexibility. The metal plate may have a single layer structure or a multilayer structure.

  The insulating layer is provided on the metal plate and includes liquid crystal polyester.

  The liquid crystal polyester plays a role as an adhesive for bonding the metal plate and the copper foil and a role for flattening the surface of the insulating layer. Liquid crystalline polyester is an electrically insulating material and has a higher specific resistance than many other resins.

  The liquid crystalline polyester is a polyester that exhibits liquid crystallinity in a molten state, and is preferably a liquid crystalline polyester that melts at a temperature of 450 ° C. or lower. The liquid crystal polyester may be a liquid crystal polyester amide, a liquid crystal polyester ether, a liquid crystal polyester carbonate, or a liquid crystal polyester imide. The liquid crystal polyester is preferably a wholly aromatic liquid crystal polyester using only an aromatic compound as a raw material monomer.

  A typical example of the liquid crystal polyester is polymerization (polycondensation) of an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid, and at least one compound selected from the group consisting of an aromatic diol, an aromatic hydroxyamine, and an aromatic diamine. At least one selected from the group consisting of aromatic dicarboxylic acids and aromatic diols, aromatic hydroxyamines and aromatic diamines. Examples thereof include a liquid crystal polyester obtained by polymerizing a compound and a liquid crystal polyester obtained by polymerizing a polyester such as polyethylene terephthalate and an aromatic hydroxycarboxylic acid. Here, the aromatic hydroxycarboxylic acid, the aromatic dicarboxylic acid, the aromatic diol, the aromatic hydroxyamine, and the aromatic diamine are each independently replaced with a part or all of the polymerizable derivative. Also good.

  Examples of polymerizable derivatives of a compound having a carboxyl group such as aromatic hydroxycarboxylic acid and aromatic dicarboxylic acid include derivatives (esters) obtained by converting a carboxyl group into an alkoxycarbonyl group or an aryloxycarbonyl group, carboxyl Derivatives obtained by converting a group into a haloformyl group (acid halide) and derivatives obtained by converting a carboxyl group into an acyloxycarbonyl group (an acid anhydride) are included. Examples of polymerizable derivatives of hydroxyl group-containing compounds such as aromatic hydroxycarboxylic acids, aromatic diols and aromatic hydroxyamines include derivatives obtained by acylating hydroxyl groups and converting them into acyloxyl groups (acylated products) ). Examples of polymerizable derivatives of amino group-containing compounds such as aromatic hydroxyamines and aromatic diamines include derivatives (acylated products) obtained by acylating amino groups and converting them to acylamino groups.

  The liquid crystalline polyester preferably has a repeating unit represented by the following formula (1) (hereinafter sometimes referred to as “repeating unit (1)”), and the repeating unit (1) and the following formula (2) A repeating unit represented (hereinafter sometimes referred to as “repeating unit (2)”) and a repeating unit represented by the following formula (3) (hereinafter sometimes referred to as “repeating unit (3)”). It is more preferable to have.

(1) —O—Ar ¹ —CO—
(2) —CO—Ar ² —CO—
(3) ^-X-Ar 3 -Y-

(Ar ¹ represents a phenylene group, a naphthylene group, or a biphenylylene group. Ar ² and Ar ³ each independently represent a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by the following formula (4). X And Y each independently represents an oxygen atom or an imino group (—NH—), and each hydrogen atom in the group represented by Ar ¹ , Ar ² or Ar ³ is independently a halogen atom or an alkyl group. Alternatively, it may be substituted with an aryl group.)

(4) -Ar ⁴ -Z-Ar ^5-

(Ar ⁴ and Ar ⁵ each independently represent a phenylene group or a naphthylene group. Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.)

As said halogen atom, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are mentioned. Examples of the alkyl group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-hexyl group, 2-ethylhexyl group, An n-octyl group and n-decyl group are mentioned, The carbon number is 1-10 normally. Examples of the aryl group include a phenyl group, an o-tolyl group, an m-tolyl group, a p-tolyl group, a 1-naphthyl group, and a 2-naphthyl group, and the number of carbon atoms is usually 6 to 20. . When the hydrogen atom is substituted with these groups, the number is usually 2 or less for each of the groups represented by Ar ¹ , Ar ² or Ar ³ , and preferably 1 It is as follows.

  Examples of the alkylidene group include a methylene group, an ethylidene group, an isopropylidene group, an n-butylidene group, and a 2-ethylhexylidene group, and the number of carbon atoms is usually 1 to 10.

The repeating unit (1) is a repeating unit derived from a predetermined aromatic hydroxycarboxylic acid. The repeating unit (1) includes a repeating unit (1) in which Ar ¹ is a p-phenylene group (a repeating unit derived from p-hydroxybenzoic acid), and a repeating unit in which Ar ¹ is a 2,6-naphthylene group ( 1) (Repeating unit derived from 6-hydroxy-2-naphthoic acid) is preferred.

The repeating unit (2) is a repeating unit derived from a predetermined aromatic dicarboxylic acid. As the repeating unit (2), a repeating unit (2) in which Ar ² is a p-phenylene group (a repeating unit derived from terephthalic acid), a repeating unit (2) in which Ar ² is an m-phenylene group (in isophthalic acid) derived from repeating units), a repeating unit Ar ² is derived from the repeating unit (2) (2,6-naphthalenedicarboxylic acid is 2,6-naphthylene group), and Ar ² is diphenyl ether - ether-4,4 ' A repeating unit (2) which is a diyl group (a repeating unit derived from diphenyl ether-4,4′-dicarboxylic acid) is preferred.

The repeating unit (3) is a repeating unit derived from a predetermined aromatic diol, aromatic hydroxylamine or aromatic diamine. As the repeating unit (3), a repeating unit (3) in which Ar ³ is a p-phenylene group (a repeating unit derived from hydroquinone, p-aminophenol or p-phenylenediamine) is preferable.

  The content of the repeating unit (1) is the total amount of all repeating units (the mass equivalent amount of each repeating unit (moles by dividing the mass of each repeating unit constituting the liquid crystal polyester by the formula amount of each repeating unit). ) And the total value thereof) is usually 30 mol% or more, preferably 30 to 80 mol%, more preferably 30 to 60 mol%, still more preferably 30 to 40 mol%. The content of the repeating unit (2) is usually 35 mol% or less, preferably 10 to 35 mol%, more preferably 20 to 35 mol%, still more preferably 30 to 35 mol, based on the total amount of all repeating units. %. The content of the repeating unit (3) is usually 35 mol% or less, preferably 10 to 35 mol%, more preferably 20 to 35 mol%, still more preferably 30 to 35 mol, based on the total amount of all repeating units. %. As the content of the repeating unit (1) is increased, the heat resistance, strength and rigidity are likely to be improved. However, if the content is too large, the solubility in a solvent is likely to be lowered.

  The ratio between the content of the repeating unit (2) and the content of the repeating unit (3) is expressed as [content of repeating unit (2)] / [content of repeating unit (3)] (mol / mol). The ratio is usually 0.9 / 1 to 1 / 0.9, preferably 0.95 / 1 to 1 / 0.95, and more preferably 0.98 / 1 to 1 / 0.98.

  In addition, liquid crystalline polyester may have 2 or more types of repeating units (1)-(3) each independently. Further, the liquid crystalline polyester may have a repeating unit other than the repeating units (1) to (3), but the content thereof is usually 10 mol% or less with respect to the total amount of all repeating units, preferably 5 mol% or less.

  The liquid crystalline polyester has a repeating unit (3) in which X and / or Y is an imino group as the repeating unit (3), that is, a repeating unit derived from a predetermined aromatic hydroxylamine and / or an aromatic diamine. Having the repeating unit derived from is preferable because it has excellent solubility in a solvent, and it is more preferable that the repeating unit (3) has only the repeating unit (3) in which X and / or Y is an imino group.

  The liquid crystal polyester is preferably produced by melt polymerization of raw material monomers corresponding to the repeating units constituting the liquid crystal polyester, and solid-phase polymerization of the obtained polymer (prepolymer). Thereby, high molecular weight liquid crystal polyester having high heat resistance, strength and rigidity can be produced with good operability. Melt polymerization may be carried out in the presence of a catalyst. Examples of this catalyst include metal compounds such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, and antimony trioxide, And nitrogen-containing heterocyclic compounds such as 4- (dimethylamino) pyridine and 1-methylimidazole, and nitrogen-containing heterocyclic compounds are preferably used.

  The liquid polyester has a flow initiation temperature of usually 250 ° C. or higher, preferably 250 ° C. to 350 ° C., more preferably 260 ° C. to 330 ° C. As the flow start temperature is higher, the heat resistance, strength, and rigidity are more likely to be improved. However, if the flow start temperature is too high, the solubility in a solvent tends to be low, and the viscosity of the liquid composition tends to be high.

The flow start temperature is also called flow temperature or flow temperature, and the temperature is raised at a rate of 4 ° C./min under a load of 9.8 MPa (100 kg / cm ² ) using a capillary rheometer while liquid crystal polyester is used. Is a temperature showing a viscosity of 4800 Pa · s (48000 poise) when extruded from a nozzle having an inner diameter of 1 mm and a length of 10 mm, and is a measure of the molecular weight of the liquid crystalline polyester (Naide Koide, “ "Liquid Crystal Polymer -Synthesis / Molding / Application-", see CMC Corporation, June 5, 1987, p. 95).

  The ratio of liquid crystalline polyester to an insulating layer is 20-100 volume% normally, Preferably it is 30-80 volume%. If this ratio is too small, the adhesiveness between the insulating layer and the copper foil is lowered, or the surface flatness of the insulating layer is lowered.

  The insulating layer preferably further contains an inorganic filler. Examples of the inorganic filler include beryllium oxide, magnesium oxide, aluminum oxide, silicon oxide, zinc oxide, silicon nitride, boron nitride, aluminum nitride, and talc, and two or more thereof may be used. Of these, aluminum oxide, silicon nitride, boron nitride, and aluminum nitride are preferable.

  As at least a part of the inorganic filler, an inorganic filler that has been surface-treated may be used in order to improve the adhesion to the liquid crystal polyester. Examples of surface treatment agents that can be used for this surface treatment include silane coupling agents, titanium coupling agents, aluminum coupling agents, zirconium coupling agents, long chain fatty acids, isocyanate compounds, and epoxy groups and methoxysilyl groups. And polymers having an amino group or a hydroxyl group.

  The ratio of the inorganic fillers in the insulating layer is a total of 0 to 80% by volume, preferably 20 to 70% by volume when two or more kinds are included. If this ratio is too large, the adhesion between the insulating layer and the copper foil is lowered.

  The insulating layer may contain components other than the liquid crystal polyester and the inorganic filler, for example, resins other than the liquid crystal polyester, organic fillers, additives, etc., but the proportion of the insulating layer occupies a plurality of types. In general, the total amount is 0 to 10% by volume.

  Examples of resins other than liquid crystal polyester include polypropylene, polyamide, polyester other than liquid crystal polyester, thermoplastic resin other than liquid crystal polyester such as polyphenylene sulfide, polyether ketone, polycarbonate, polyether sulfone, polyphenylene ether, polyether imide; and Thermosetting resins, such as a phenol resin, an epoxy resin, a polyimide resin, and cyanate resin, are mentioned. Examples of the organic filler include organic fillers such as a cured epoxy resin, a crosslinked benzoguanamine resin, and a crosslinked acrylic resin. Examples of additives include leveling agents, antifoaming agents, antioxidants, ultraviolet absorbers, flame retardants, and colorants.

  The copper foil is provided on the insulating layer and faces the metal plate with the insulating layer interposed therebetween. In the present invention, as the copper foil, a copper foil having at least one surface that is a rough surface with a 10-point average roughness of 10 μm or more is used and laminated so that the rough surface is in contact with the insulating layer. Thereby, the laminated board excellent in the adhesiveness of an insulating layer and copper foil and the heat dissipation of an insulating layer can be obtained.

  The copper foil may be a rough surface with a 10-point average roughness of 10 μm or more on both sides, or only one surface may be a rough surface with a 10-point average roughness of 10 μm or more. From the viewpoint of ease, it is preferable that one surface is a rough surface having a 10-point average roughness of 10 μm or more and the other surface is a mirror surface having a 10-point average roughness of 2 μm or less.

  The ten-point average roughness of the rough surface is preferably 11 μm or more, more preferably 13 μm or more, whereby the adhesion between the insulating layer and the metal foil is further improved. Moreover, the ten-point average roughness of the rough surface is preferably 20 μm or less, more preferably 15 μm or less, which facilitates etching of the copper foil.

  Here, the ten-point average roughness of the surface of the copper foil is a surface roughness parameter based on JISB0601-1994.

  The thickness of the copper foil is usually 18 μm or more, preferably 35 μm or more, whereby the adhesion between the insulating layer and the copper foil is further improved. Moreover, the thickness of copper foil is 140 micrometers or less normally, Preferably it is 70 micrometers or less, and, thereby, it becomes easy to bend a laminated board.

  Production of the laminated board of the present invention is as follows. (A): First, a laminated intermediate of a copper foil and an insulating layer is produced using a rough surface of a copper foil as a bonding surface, and then this laminated intermediate is insulated. The layer surface may be bonded to the metal plate by thermocompression bonding or the like. (B): First, a laminated intermediate of the metal plate and the insulating layer is manufactured, and then this laminated intermediate. May be performed by bonding the rough surface of the copper foil to the bonding surface by thermocompression bonding or the like with the insulating layer surface as the bonding surface. (C): First, an insulating film to be an insulating layer is manufactured, and then The insulating film may be formed by sandwiching the rough surface of the copper foil between the copper foil and the metal plate and bonding them by thermocompression bonding or the like.

  The insulating layer is formed by applying a liquid composition containing a liquid crystal polyester, an inorganic filler, and other components as required, and a solvent to a support, and drying (solvent removal) the resulting coating film. It is preferable to carry out by. In that case, the laminated intermediate body of the copper foil and insulating layer in said (A) can be manufactured by using copper foil as a support body. Moreover, the laminated intermediate body of the metal plate and insulating layer in said (B) can be manufactured by using a metal plate as a support body. In addition, when a resin film other than copper foil and metal plate, for example, a polyester film, a polypropylene film, a fluororesin film, a nylon film, or a polymethylpentene film is used as a support, an insulation formed on the support By transferring the layer from the support to the copper foil by thermocompression bonding or the like, a laminated intermediate of the copper foil and the insulating layer in (A) can be produced, and the insulating layer formed on the support is supported. By transferring from the body to the metal plate by thermocompression bonding or the like, a laminated intermediate body of the metal plate and the insulating layer in (B) can be produced, and the insulating layer formed on the support is peeled off from the support. Thus, the insulating film in (C) can be produced.

  The liquid composition is preferably prepared by dispersing the inorganic filler and, if necessary, other components in a solution obtained by dissolving liquid crystal polyester and other components, if necessary, in a solvent. The inorganic filler may be dispersed in the solution while being pulverized by a ball mill, three rolls, a centrifugal stirrer, a bead mill or the like. Further, prior to dispersing the inorganic filler in the solution, a coupling agent such as a silane coupling agent or a titanium coupling agent or an ion adsorbent may be added.

  As the solvent, a solvent that can dissolve the liquid crystal polyester to be used, specifically, a solvent that can be dissolved at a concentration of 1% by mass or more at 50 ° C. ([liquid crystal polyester] / [liquid crystal polyester + solvent]) is appropriately selected. Used.

  Examples of solvents include halogenated hydrocarbons such as dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, o-dichlorobenzene; p-chlorophenol, pentachlorophenol, pentafluorophenol Halogenated phenols such as diethyl ether, tetrahydrofuran, 1,4-dioxane, etc .; ketones such as acetone and cyclohexanone; esters such as ethyl acetate and γ-butyrolactone; carbonates such as ethylene carbonate and propylene carbonate; amines such as triethylamine Nitrogen-containing heteroaromatic compounds such as pyridine; nitriles such as acetonitrile and succinonitrile; amides such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone; Urea compounds such as tramethylurea; nitro compounds such as nitromethane and nitrobenzene; sulfur compounds such as dimethyl sulfoxide and sulfolane; and phosphorus compounds such as hexamethylphosphoric acid amide and tri-n-butylphosphoric acid. May be used.

  As the solvent, since it is low in corrosivity and easy to handle, an aprotic compound, particularly a solvent mainly comprising an aprotic compound having no halogen atom, is preferred, and the proportion of the aprotic compound in the entire solvent is: Preferably it is 50-100 mass%, More preferably, it is 70-100 mass%, More preferably, it is 90-100 mass%. As the aprotic compound, amides such as N, N-dimethylformamide, N, N-dimethylacetamide and N-methylpyrrolidone are preferably used because the liquid crystalline polyester is easily dissolved.

  Moreover, as a solvent, since it is easy to melt | dissolve liquid crystalline polyester, the solvent which has a compound whose dipole moment is 3-5 as a main component is preferable, and the ratio of the compound whose dipole moment which occupies for the whole solvent is 3-5 Is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and still more preferably 90 to 100% by mass, and a compound having a dipole moment of 3 to 5 is used as the aprotic compound. Is preferred.

  Moreover, as a solvent, since it is easy to remove, the solvent which has as a main component the compound whose boiling point in 1 atmosphere is 220 degrees C or less is preferable, and the ratio of the compound whose boiling point in 1 atmosphere in the whole solvent is 220 degrees C or less Is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and still more preferably 90 to 100% by mass, and a compound having a boiling point of 220 ° C. or less at 1 atm is used as the aprotic compound. It is preferable.

  Content of the liquid crystal polyester in a liquid composition is 5-60 mass% normally with respect to the total amount of liquid crystal polyester and a solvent, Preferably it is 10-50 mass%, More preferably, it is 15-45 mass%, desired It adjusts suitably so that the liquid composition of this viscosity may be obtained.

  Examples of the method of applying the liquid composition to the support include a roll coating method, a bar coating method, a screen printing method, a die coater method, and a comma coater method, which may be a continuous method or a single plate method. May be.

  The coating film is preferably dried by evaporating the solvent from the coating film. When using a support other than copper foil and metal plate as the support, after drying the coating film formed on the support and transferring it from the support to the copper foil or metal plate by thermocompression bonding, etc., part of the solvent Is preferably carried out so as to remain in the dried coating film. In this case, the amount of solvent in the dried coating film is preferably 1 to 25% by mass. A drying temperature is 50-180 degreeC normally, Preferably it is 80-150 degreeC.

  By heat-treating the dried coating film formed on the support or the dried coating film transferred to the copper foil or metal plate, the molecular weight and crystallinity of the liquid crystal polyester can be adjusted, and adhesion An insulating layer having excellent properties and thermal conductivity can be obtained. The heat treatment is usually performed at 250 to 350 ° C., preferably 270 to 320 ° C. in an inert gas atmosphere such as nitrogen gas.

  In this way, when the laminated intermediate of the copper foil and the insulating layer is obtained, as described in (A) above, by laminating the laminated intermediate with the insulating layer surface as a bonding surface by thermocompression bonding, The laminated board of this invention is obtained. Moreover, when the laminated intermediate body of a metal plate and an insulating layer is obtained, as the said (B), this laminated intermediate body is affixed with the rough surface of copper foil, thermocompression bonding, etc. by using the insulating layer surface as a bonding surface. By combining them, the laminate of the present invention can be obtained. Moreover, when the insulating layer formed on the support is peeled from the support to obtain an insulating film, as described in (C) above, the insulating film is formed with a copper foil rough surface and a copper foil as a bonding surface. The laminated sheet of the present invention can be obtained by sandwiching it with a metal sheet and bonding them together by thermocompression bonding or the like.

  The metal base circuit board of the present invention can be obtained by patterning the copper foil of the laminated board of the present invention to form a circuit pattern and performing processing such as cutting and drilling as necessary. The patterning of the copper foil is performed, for example, by forming a mask pattern on the copper foil and removing the exposed portion of the copper foil by etching.

[Measurement of flow start temperature of liquid crystalline polyester]
Using a flow tester (“CFT-500 type” manufactured by Shimadzu Corporation), about 2 g of liquid crystalline polyester was filled into a cylinder attached with a die having a nozzle having an inner diameter of 1 mm and a length of 10 mm, and 9.8 MPa (100 kg). The liquid crystal polyester was melted while being heated at a rate of 4 ° C./min under a load of / cm ² ), extruded from a nozzle, and a temperature showing a viscosity of 4800 Pa · s (48000 P) was measured.

[Measurement of viscosity of liquid crystal polyester solution]
Using a B-type viscometer (“TVL-20” from Toki Sangyo Co., Ltd.) The measurement was performed at a rotation speed of 20 rpm using 21 rotors.

(Measurement of ten-point average roughness of metal plate surface)
Ten-point average roughness of the surface of the metal plate was measured using a surface roughness measuring device (KLA Tencor Co., Ltd., calculation standard JIS B 0601-1994), measurement speed: 5 μm / second, evaluation length: 1. Measurement was performed under the condition of 0 mm.

〔Copper foil〕
As the copper foil, the following copper foil having a rough surface on one side and a mirror surface on the other side was used.
Copper foil (1): LSMtron Ltd. “LSU-ST” (10-point average roughness of rough surface: 12 μm, thickness: 35 μm).
Copper foil (2): “GP-35” manufactured by Nippon Electrolytic Co., Ltd. (10-point average roughness of rough surface: 14 μm, thickness: 35 μm).
Copper foil (3): “CF-T8G-UN-35” manufactured by Fukuda Metal Foil Powder Co., Ltd. (10-point average roughness of rough surface: 9.5 μm, thickness: 35 μm).

[Production of liquid crystalline polyester]
In a reactor equipped with a stirrer, a torque meter, a nitrogen gas introduction tube, a thermometer and a reflux condenser, 1976 g (10.5 mol) of 6-hydroxy-2-naphthoic acid and 1474 g (9.75 mol) of 4-hydroxyacetanilide were added. ), 1620 g (9.75 mol) of isophthalic acid and 2374 g (23.25 mol) of acetic anhydride, and after replacing the gas in the reactor with nitrogen gas, the mixture was stirred at room temperature to 150 ° C. under a nitrogen gas stream. The mixture was heated up to 15 minutes and refluxed at 150 ° C. for 3 hours. Next, while distilling off by-product acetic acid and unreacted acetic anhydride, the temperature was raised from 150 ° C. to 300 ° C. over 2 hours and 50 minutes, held at 300 ° C. for 1 hour, and then the contents were taken out from the reactor, Cooled to room temperature. The obtained solid was pulverized with a pulverizer to obtain a powdery prepolymer. The flow initiation temperature of this prepolymer was 235 ° C. Next, the prepolymer was heated from room temperature to 223 ° C. over 6 hours under a nitrogen atmosphere and held at 223 ° C. for 3 hours to solid-phase polymerize, and then cooled to powdery liquid crystalline polyester Got. The liquid crystal polyester had a flow start temperature of 270 ° C.

[Preparation of liquid crystal polyester solution]
3000 g of liquid crystal polyester was added to 7000 g of N, N-dimethylacetamide and heated at 100 ° C. for 2 hours to obtain a liquid crystal polyester solution. The viscosity of this solution was 320 cP.

Example 1
[Production of laminated intermediate of copper foil and insulating layer]
After apply | coating the liquid crystalline polyester solution to the rough surface of copper foil (1), it dried at 100 degreeC for 30 minutes. The obtained laminated intermediate of the copper foil and the dried coating film was heat-treated at 300 ° C. for 3 hours in a nitrogen gas atmosphere to obtain a laminated intermediate of the copper foil and the insulating layer.

[Manufacture of laminates]
The laminated intermediate of the copper foil and the insulating layer is overlapped with a metal plate (aluminum alloy plate: thermal conductivity 140 W · m ⁻¹ · K ⁻¹ ) having a thickness of 1.5 mm so that the surface of the insulating layer is in contact. SUS plate ("FR-HT.530", SUS420J2 plate, thickness 5mm) from Nippon Chem-Tech Co., Ltd. and poly (paraphenylenebenzobis) on both sides of the copper foil and metal plate of the laminated intermediate. Oxazole) cushioning material ("KG331C3G type" manufactured by Ichikawa Technofabrics Co., Ltd., thickness 5 mm) is stacked in this order. 300 mm, 300 mm in width), and laminated by heating and pressing for 20 minutes under reduced pressure under conditions of 340 ° C. and 5 MPa, to obtain a laminate. In addition, the thickness of the insulating layer of the obtained laminated board was 35 micrometers.

Example 2
A laminated board was produced in the same manner as in Example 1 except that the copper foil (2) was used as the copper foil. In addition, the thickness of the insulating layer of the obtained laminated board was 35 micrometers.

Example 3
Boron nitride (“KBN” of Changsung Co., Ltd., average volume particle size 10 μm) and aluminum oxide (“AA-3” of Sumitomo Chemical Co., Ltd., average volume particle size 3 μm) are added to the liquid crystal polyester solution. A dispersion was obtained. At that time, the addition amounts of boron nitride and aluminum oxide were 15% by volume and 43% by volume, respectively, with respect to the total amount of liquid crystal polyester, boron nitride and aluminum oxide. This dispersion was defoamed by stirring for 5 minutes using a centrifugal stirring deaerator. The viscosity of the dispersion after defoaming was 7500 cP. A laminated board was produced in the same manner as in Example 1 except that the obtained defoamed dispersion was used instead of the liquid crystal polyester solution. In addition, the thickness of the insulating layer of the obtained laminated board was 85 micrometers.

Example 4
A laminated board was produced in the same manner as in Example 3 except that the copper foil (2) was used as the copper foil. In addition, the thickness of the insulating layer of the obtained laminated board was 85 micrometers.

Comparative Example 1
A laminated board was produced in the same manner as in Example 1 except that the copper foil (3) was used as the copper foil. In addition, the thickness of the insulating layer of the obtained laminated board was 35 micrometers.

Comparative Example 2
A laminated board was produced in the same manner as in Example 3 except that the copper foil (3) was used as the copper foil. In addition, the thickness of the insulating layer of the obtained laminated board was 85 micrometers.

[Measurement of peel strength of copper foil]
The copper foils of the laminates obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were partially removed by etching to form a 10 mm wide copper foil pattern. Grasp one end of this copper foil pattern and pull the copper foil pattern from the metal plate at a speed of 50 mm / min while applying a force so that the peeled portion of the copper foil pattern is perpendicular to the main surface of the metal plate. I peeled it off. At this time, the force applied to the copper foil pattern was defined as peel strength.

[Measurement of thermal resistance of laminates]
The copper foil of the laminated board obtained in Examples 1 to 4 and Comparative Examples 1 and 2 was partially removed by etching to form a 14 mm × 10 mm land. After mounting a transistor ("TO220" from Toshiba Corporation) on this land using solder, this was set in the water cooling device so that the metal substrate faced the cooling surface of the cooling device through the silicone grease layer. . Next, power P of 30 W was supplied to the transistor, and the temperature T1 of the transistor and the temperature T2 of the cooling surface of the cooling device were measured. The difference T1-T2 between the temperature T1 and the temperature T2 obtained in this way was determined, and the ratio (T1-T2) / P between the difference T1-T2 and the supplied power P was calculated as the thermal resistance.

Claims (7)

  A laminated plate having a metal plate, an insulating layer provided on the metal plate and containing liquid crystal polyester, and a copper foil provided on the insulating layer, the surface of the copper foil in contact with the insulating layer A laminated board having a ten-point average roughness of 10 μm or more.   The laminate according to claim 1, wherein the copper foil has a thickness of 35 μm or more. The liquid crystalline polyester is a liquid crystalline polyester having a repeating unit represented by the following formula (1), a repeating unit represented by the following formula (2), and a repeating unit represented by the following formula (3). Item 3. A laminated board according to item 1 or 2.
(1) —O—Ar ¹ —CO—
(2) —CO—Ar ² —CO—
(3) ^-X-Ar 3 -Y-
(Ar ¹ represents a phenylene group, a naphthylene group, or a biphenylylene group. Ar ² and Ar ³ each independently represent a phenylene group, a naphthylene group, a biphenylylene group, or a group represented by the following formula (4). X And Y each independently represents an oxygen atom or an imino group, and each hydrogen atom in the group represented by Ar ¹ , Ar ² or Ar ³ is independently substituted with a halogen atom, an alkyl group or an aryl group. May be.)
(4) -Ar ⁴ -Z-Ar ^5-
(Ar ⁴ and Ar ⁵ each independently represent a phenylene group or a naphthylene group. Z represents an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.)   The liquid crystalline polyester has a repeating unit represented by the formula (1) of 30 mol% to 80 mol% and a repeating unit represented by the formula (2) based on the total amount of all repeating units constituting the liquid crystalline polyester. The laminate according to claim 3, which is a liquid crystal polyester having 10 mol% to 35 mol% and 10 mol% to 35 mol% of the repeating unit represented by the formula (3).   The laminate according to claim 3 or 4, wherein X and / or Y is an imino group.   The laminate according to any one of claims 1 to 5, wherein the insulating layer is an insulating layer further containing an inorganic filler.   The metal base circuit board formed by patterning the said copper foil of the laminated board in any one of Claims 1-6.