JP2013004952A - Laminate for cof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminate for COF which has sufficient rigidity and flexibility.SOLUTION: A laminate 1 for COF includes an insulating layer 10 containing an inorganic cloth and a liquid crystal polyester and having a thickness of 150-300 μm. A metal layer 16 is provided on at least one surface of the insulating layer.

Description

  The present invention relates to a laminate for COF (Chip on Film).

  In recent years, there has been a remarkable development in technology in the field of microelectronics, and there has been a significant demand for miniaturization and weight reduction in portable electronic devices and the like, and expectations for high-density mounting are increasing. Along with this, there is a demand for materials that can withstand higher levels of integration, such as multilayer wiring boards, narrowing of wiring pitch, and miniaturization of via holes.

  An example of a substrate material that meets this requirement is polyimide. Polyimide has excellent heat resistance and is not inferior to other plastic materials in mechanical, electrical and chemical properties. For example, printed wiring board (PWB), flexible printed wiring board (FPC) ), Tapes for automatic tape bonding (TAB), and tapes for chip-on-film (COF), etc., are widely used as insulating substrate materials for electronic components. Specifically, the PWB, FPC, TAB tape and COF tape are manufactured by processing a metal-coated polyimide substrate mainly coated with copper as a metal conductor layer on at least one surface of a polyimide substrate which is an insulating layer. Has been.

  On the other hand, polyimide has a problem that water absorption and thermal expansion coefficient are relatively large. Therefore, recently, a thermoplastic liquid crystal polymer has attracted attention as a material for an insulating layer instead of polyimide. However, the thermoplastic liquid crystal polymer is excellent in high frequency characteristics and dimensional stability, but the molecules constituting the polymer are easily oriented, so that a molded product having excellent mechanical properties can be obtained, while the injection molding method and the inflation molding method are used. When it was formed into a film, there was a problem that it was easily cracked in the orientation direction or was easily torn. Further, when it is used as a base material in the form of a film as in the prior art, there is a problem that the rigidity as the base material is insufficient. On the other hand, the method of using the laminated sheet which laminated | stacked these using the intermediate sheet other than a film-form thermoplastic liquid crystal polymer is disclosed (refer patent document 1).

Japanese Patent Laid-Open No. 11-309803

  However, the laminate disclosed in Patent Document 1 still has insufficient rigidity and has a problem that it does not have sufficient rigidity and flexibility required for chip mounting.

  This invention is made | formed in view of the said situation, and makes it a subject to provide the laminated board for COF which has sufficient rigidity and flexibility.

To solve the above problem,
The present invention relates to a laminate for COF, comprising an insulating layer containing inorganic cloth and liquid crystal polyester and having a thickness of 150 to 300 μm, and a metal layer provided on at least one surface of the insulating layer. I will provide a.
In the COF laminate of the present invention, the insulating layer is obtained by laminating a plurality of insulating base materials, and the insulating base material is obtained by impregnating the liquid crystal polyester into the inorganic cloth. preferable.
In the COF laminate of the present invention, the inorganic cloth is preferably a glass cloth.
In the COF laminate of the present invention, the liquid crystal polyester preferably has a repeating unit represented by the following general formulas (1), (2) and (3).
(1) —O—Ar ¹ —CO—
(2) —CO—Ar ² —CO—
(3) ^-X-Ar 3 -Y-
(In the formula, Ar ¹ is a phenylene group, a naphthylene group or a biphenylylene group; Ar ² and Ar ³ are each independently a phenylene group, a naphthylene group, a biphenylylene group or a group represented by the following general formula (4): Yes; X and Y are each independently an oxygen atom or imino group; one or more hydrogen atoms in Ar ¹ , Ar ² and Ar ³ are each independently substituted with a halogen atom, an alkyl group or an aryl group May be.)
(4) -Ar ⁴ -Z-Ar ^5-
(In the formula, Ar ⁴ and Ar ⁵ are each independently a phenylene group or a naphthylene group; Z is an oxygen atom, a sulfur atom, a carbonyl group, a sulfonyl group, or an alkylidene group.)
In the COF laminate of the present invention, the liquid crystalline polyester comprises 30 to 80 mol% of the repeating unit represented by the general formula (1) with respect to the total amount of all repeating units constituting the liquid crystalline polyester. It is preferable to have 10 to 35 mol% of the repeating unit represented by the formula (2) and 10 to 35 mol% of the repeating unit represented by the general formula (3).
In the COF laminate of the present invention, in the general formula (3), X and / or Y are preferably imino groups.

  According to the present invention, a COF laminate having sufficient rigidity and flexibility can be provided.

It is a schematic sectional drawing for demonstrating the manufacturing method of the laminated board for COF which concerns on this invention. In the manufacturing method shown in FIG. 1, it is a schematic sectional drawing for demonstrating a hot press method simultaneously with an insulating base material further in metal foil. It is a schematic sectional drawing for demonstrating the method of forming the several insulating layer simultaneously applying the manufacturing method shown in FIG. It is a schematic sectional drawing for demonstrating the method of forming the several insulating layer simultaneously applying the manufacturing method shown in FIG.

A laminate for COF (Chip on Film) according to the present invention (hereinafter sometimes referred to as “laminate”) includes an inorganic cloth and a liquid crystal polyester, and includes an insulating layer having a thickness of 150 to 300 μm. A metal layer is provided on at least one surface of the insulating layer. Such a laminate has sufficient rigidity and flexibility, and has sufficient mechanical properties for chip mounting.
Hereinafter, the present invention will be described in detail with reference to the drawings.

  Examples of the insulating layer include those composed of an insulating base material in which the inorganic cloth is impregnated with the liquid crystal polyester (hereinafter sometimes referred to as “liquid crystal polyester-impregnated base material”).

The insulating layer may be composed of a single insulating substrate, but is preferably a laminate of a plurality of insulating substrates.
When the insulating layer is a laminate of a plurality of insulating base materials, all of the plurality of insulating base materials may be the same, a part thereof may be different, or all may be different. Moreover, when the number of insulation base materials is plural, the number should just be 2 or more, and can be arbitrarily selected according to the objective.

  The thickness of one insulating base material is preferably 5 to 200 μm, more preferably 10 to 185 μm.

  The inorganic cloth impregnated with the liquid crystal polyester is a sheet made of inorganic fibers, and examples of the inorganic fibers include glass fibers, alumina fibers, and ceramic fibers such as silicon-containing ceramic fibers. The inorganic cloth is preferably a sheet mainly made of glass fibers, that is, a glass cloth.

  The glass cloth is preferably made of alkali-containing glass fiber, non-alkali glass fiber or low dielectric glass fiber. Moreover, the fiber which comprises a glass cloth may mix the ceramic fiber or carbon fiber which consists of ceramics other than glass in the part. The fibers constituting the glass cloth may be surface-treated with a coupling agent such as an aminosilane coupling agent, an epoxysilane coupling agent, or a titanate coupling agent.

  As a method for producing a glass cloth composed of these fibers, the fibers forming the glass cloth are dispersed in water, and if necessary, a paste such as an acrylic resin is added, and after making paper with a paper machine, drying is performed. Examples thereof include a method for obtaining a nonwoven fabric and a method using a known weaving machine.

Plain weave, satin weave, twill weave, Nanako weave, etc. can be used as the weaving method of the fibers. The weaving density is preferably 10 to 100 pieces / 25 mm.
The mass per unit area of the glass cloth is preferably 10 to 300 g / m ² .
The thickness of the glass cloth is preferably 10 to 200 μm, more preferably 10 to 180 μm.

The glass cloth may be a commercial product. Examples of commercially available glass cloths that can be easily obtained include those for insulating impregnated substrates of electronic components, which can be obtained from Asahi Sebel Co., Ltd., Nitto Boseki Co., Ltd., Arisawa Manufacturing Co., Ltd., and the like.
Examples of commercially available glass cloth having a suitable thickness include those having IPC names of 1035, 1078, 2116, and 7628.

  The liquid crystalline polyester is a liquid crystalline polyester that exhibits liquid crystallinity in a molten state, and is preferably melted 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.

As a typical example of liquid crystal polyester,
(I) 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 are polymerized (polycondensed). thing,
(II) a polymer obtained by polymerizing plural kinds of aromatic hydroxycarboxylic acids,
(III) A polymer obtained by polymerizing 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,
(IV) What polymerizes polyester, such as a polyethylene terephthalate, and aromatic hydroxycarboxylic acid is mentioned. 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 those obtained by converting a carboxyl group into an alkoxycarbonyl group or an aryloxycarbonyl group (ester), carboxyl Examples include those obtained by converting a group into a haloformyl group (acid halide), and those obtained by converting a carboxyl group into an acyloxycarbonyl group (acid anhydride).
Examples of polymerizable derivatives of hydroxyl group-containing compounds such as aromatic hydroxycarboxylic acids, aromatic diols and aromatic hydroxyamines include those obtained by acylating hydroxyl groups and converting them to acyloxyl groups (acylated products) ).
Examples of polymerizable derivatives of amino group-containing compounds such as aromatic hydroxyamines and aromatic diamines include those obtained by acylating an amino group and converting it to an acylamino group (acylated product).

  The liquid crystalline polyester preferably has a repeating unit represented by the following general formula (1) (hereinafter sometimes referred to as “repeating unit (1)”). The repeating unit (1) and the following general formula (2) ) (Hereinafter sometimes referred to as “repeat unit (2)”) and a repeat unit represented by the following general formula (3) (hereinafter referred to as “repeat unit (3)”). More preferably).

(1) —O—Ar ¹ —CO—
(2) —CO—Ar ² —CO—
(3) ^-X-Ar 3 -Y-
(In the formula, Ar ¹ is a phenylene group, a naphthylene group or a biphenylylene group; Ar ² and Ar ³ are each independently a phenylene group, a naphthylene group, a biphenylylene group or a group represented by the following general formula (4): Yes; X and Y are each independently an oxygen atom or imino group; one or more hydrogen atoms in Ar ¹ , Ar ² and Ar ³ are each independently substituted with a halogen atom, an alkyl group or an aryl group May be.)
(4) -Ar ⁴ -Z-Ar ^5-
(In the formula, Ar ⁴ and Ar ⁵ are each independently a phenylene group or a naphthylene group; Z is 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, sec-butyl group, tert-butyl group, n-pentyl group, n-hexyl group, An n-heptyl group, a 2-ethylhexyl group, an n-octyl group, an n-nonyl group, and an n-decyl group may be mentioned, and the number of carbon atoms is preferably 1-10.
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 carbon number thereof is 6 to 20. Is preferred.
When the hydrogen atom is substituted with these groups, the number is preferably 2 or less independently for each of the groups represented by Ar ¹ , Ar ² or Ar ^3. More preferably.

  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 preferably have 1 to 10 carbon atoms.

The repeating unit (1) is a repeating unit derived from a predetermined aromatic hydroxycarboxylic acid. As repeating unit (1), Ar ¹ is a 1,4-phenylene group (repeating unit derived from p-hydroxybenzoic acid), and Ar ¹ is a 2,6-naphthylene group (6-hydroxy). Preferred is a repeating unit derived from 2-naphthoic acid.

The repeating unit (2) is a repeating unit derived from a predetermined aromatic dicarboxylic acid. As the repeating unit (2), Ar ² is a 1,4-phenylene group (repeating unit derived from terephthalic acid), Ar ² is a 1,3-phenylene group (repeating unit derived from isophthalic acid) ), Ar ² is a 2,6-naphthylene group (repeating unit derived from 2,6-naphthalenedicarboxylic acid), and Ar ² is a diphenyl ether-4,4′-diyl group (diphenyl) Preferred is a repeating unit derived from ether-4,4′-dicarboxylic acid).

The repeating unit (3) is a repeating unit derived from a predetermined aromatic diol, aromatic hydroxylamine or aromatic diamine. As the repeating unit (3), Ar ³ is a 1,4-phenylene group (a repeating unit derived from hydroquinone, p-aminophenol or p-phenylenediamine), and Ar ³ is a 4,4′-biphenylylene group. (Repeating unit derived from 4,4′-dihydroxybiphenyl, 4-amino-4′-hydroxybiphenyl or 4,4′-diaminobiphenyl) is preferred.

The content of the repeating unit (1) is the total amount of all repeating units constituting the liquid crystal polyester (the substance of each repeating unit is obtained by dividing the mass of each repeating unit constituting the liquid crystal polyester by the formula weight of each repeating unit). The equivalent amount (mole) is obtained, and the sum of these is preferably 30 mol% or more, more preferably 30 to 80 mol%, still more preferably 30 to 60 mol%, and particularly preferably 30 to 40 mol%. Mol%.
The content of the repeating unit (2) is preferably 35 mol% or less, more preferably 10 to 35 mol%, still more preferably 20 to 35 mol%, based on the total amount of all repeating units constituting the liquid crystal polyester. Most preferably, it is 30-35 mol%.
The content of the repeating unit (3) is preferably 35 mol% or less, more preferably 10 to 35 mol%, still more preferably 20 to 35 mol%, based on the total amount of all repeating units constituting the liquid crystal polyester. Most preferably, it is 30-35 mol%.
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 preferably 0.9 / 1 to 1 / 0.9, more preferably 0.95 / 1 to 1 / 0.95, and still 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. The liquid crystal polyester may have a repeating unit other than the repeating units (1) to (3), and the content thereof is preferably 10 with respect to the total amount of all repeating units constituting the liquid crystal polyester. The mol% or less, more preferably 5 mol% or less.

  The liquid crystalline polyester has a repeating unit (3) in which X and / or Y is an imino group (—NH—), that is, a repeating unit derived from a predetermined aromatic hydroxylamine and / or an aromatic diamine. It is preferable that the repeating unit (3) has only those in which X and / or Y is an imino group. By doing in this way, liquid crystalline polyester becomes the thing which was more excellent in the solubility with respect to a solvent.

  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 the catalyst in this case include metals such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, and antimony trioxide. Compounds, nitrogen-containing heterocyclic compounds such as 4- (dimethylamino) pyridine, 1-methylimidazole and the like can be mentioned, and nitrogen-containing heterocyclic compounds are preferably used.

  The liquid crystal polyester has a flow initiation temperature of preferably 250 ° C. or higher, more preferably 250 ° C. to 350 ° C., and still 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 described later 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—”, CMC Co., Ltd., June 5, 1987, p. 95).

  The insulating base is impregnated in a liquid composition (liquid crystal polyester liquid composition) containing liquid crystal polyester and a solvent, preferably a liquid composition (liquid crystal polyester solution) in which liquid crystal polyester is dissolved in a solvent, It can be manufactured by removing.

  As said solvent, what can melt | dissolve the liquid crystalline polyester to be used, specifically what can melt | dissolve in the density | concentration ([liquid crystalline polyester] / [liquid crystalline polyester + solvent] x100) of 1 mass% or more at 50 degreeC, It is appropriately selected and used.

  Examples of the solvent include halogenated hydrocarbons such as dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2,2-tetrachloroethane, o-dichlorobenzene; p-chlorophenol, pentachlorophenol, pentafluoro Halogenated phenols such as phenol; Ethers such as diethyl ether, tetrahydrofuran and 1,4-dioxane; Ketones such as acetone and cyclohexanone; Esters such as ethyl acetate and γ-butyrolactone; Carbonates such as ethylene carbonate and propylene carbonate; Triethylamine and the like Amines; Nitrogen-containing heterocyclic aromatic compounds such as pyridine; Nitriles such as acetonitrile and succinonitrile; N, N-dimethylformamide, N, N-dimethylacetamide, N-methylpyrrolidone (N-methyl Amide compounds (compounds having an amide bond) such as ru-2-pyrrolidone; urea compounds such as tetramethylurea; nitro compounds such as nitromethane and nitrobenzene; sulfur compounds such as dimethyl sulfoxide and sulfolane; hexamethylphosphoric acid amide; Examples include phosphorus compounds such as tri-n-butyl phosphate, and two or more of these 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, amide compounds such as N, N-dimethylformamide, N, N-dimethylacetamide, and N-methylpyrrolidone are preferably used because they easily dissolve liquid crystal polyester.

  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 compound whose dipole moment occupies the whole solvent is 3-5 The ratio 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. It is preferable.

  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 boiling point in 1 atmosphere which occupies the whole solvent of the compound which is 220 degrees C or less The ratio is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and still more preferably 90 to 100% by mass. As the aprotic compound, a compound having a boiling point of 220 ° C. or less at 1 atm. It is preferable to use it.

  The content of the liquid crystal polyester in the liquid composition is preferably 5 to 60% by mass, more preferably 10 to 50% by mass, and further preferably 15 to 45% by mass with respect to the total amount of the liquid crystal polyester and the solvent. The liquid composition having a desired viscosity is appropriately adjusted.

  The liquid composition may contain one or more other components such as a filler, an additive, and a resin other than the liquid crystal polyester.

  Examples of the filler include inorganic fillers such as silica, alumina, titanium oxide, barium titanate, strontium titanate, aluminum hydroxide, and calcium carbonate; organic filling such as cured epoxy resin, crosslinked benzoguanamine resin, and crosslinked acrylic resin The material may be mentioned, and the content thereof is preferably 0 to 100 parts by mass with respect to 100 parts by mass of the liquid crystalline polyester.

  Examples of the additive include a leveling agent, an antifoaming agent, an antioxidant, an ultraviolet absorber, a flame retardant, and a colorant, and the content thereof is preferably 0 to 100 parts by mass of the liquid crystalline polyester. 5 parts by mass.

  Examples of the resin other than the liquid crystal polyester include polypropylene, polyamide, polyester other than the liquid crystal polyester, thermoplastic resin such as polyphenylene sulfide, polyether ketone, polycarbonate, polyether sulfone, polyphenylene ether, polyether imide; phenol resin, epoxy Examples thereof include thermosetting resins such as resins, polyimide resins, and cyanate resins, and the content thereof is preferably 0 to 20 parts by mass with respect to 100 parts by mass of the liquid crystalline polyester.

  The liquid composition can be prepared by mixing the liquid crystal polyester, the solvent, and other components used as necessary, all at once or in an appropriate order. When using a filler as another component, it is preferable to prepare by dissolving liquid crystal polyester in a solvent to obtain a liquid crystal polyester solution, and dispersing the filler in this liquid crystal polyester solution.

  Examples of the method of impregnating the inorganic cloth with the liquid composition include a method of immersing the substrate in the liquid composition in the immersion tank. In this method, the amount of liquid crystal polyester adhered to the substrate can be easily controlled by appropriately adjusting the content of liquid crystal polyester in the liquid composition, the dipping time, and the lifting speed of the immersed substrate from the liquid composition. it can.

  The method for removing the solvent from the substrate impregnated with the liquid composition is not particularly limited, but in terms of simple operation, a method of evaporating the solvent is preferable, and any one of heating, decompression and ventilation is used alone. Or the method of evaporating by combining 2 or more can be illustrated.

  The adhesion amount of the liquid crystal polyester in the liquid crystal polyester-impregnated base material obtained by removing the solvent is preferably 30 to 80% by mass and more preferably 40 to 70% by mass with respect to the liquid crystal polyester-impregnated base material. preferable.

  The insulating substrate is preferably further heat-treated after removing the solvent. Thereby, the liquid crystal polyester impregnated can be made higher in molecular weight, and heat resistance can be further improved.

  The heat treatment is preferably performed in an atmosphere of an inert gas such as nitrogen gas. And heating temperature becomes like this. Preferably it is 240-330 degreeC, More preferably, it is 250-330 degreeC, More preferably, it is 260-320 degreeC. The heat resistance of the obtained laminated board improves more by setting it as more than a lower limit. The heating time is preferably 1 to 30 hours, more preferably 1 to 10 hours. The heat resistance of the obtained laminated board improves more by setting it as more than a lower limit, and the productivity of a laminated body improves more by setting it as an upper limit or less.

  The thickness of an insulating layer is 150-300 micrometers, Preferably it is 160-290 micrometers, More preferably, it is 165-285 micrometers, More preferably, it is 165-250 micrometers. By setting the lower limit value or more, the laminate has improved rigidity, and by setting the lower limit value or less, the laminate has improved flexibility.

  The bending elastic modulus of the insulating layer is preferably 8 to 16 GPa. By setting it as such a range, it has the rigidity which was excellent by chip mounting.

  The metal layer is provided on at least one surface of the insulating layer. That is, it may be provided on only one surface (one surface) of the insulating layer, or may be provided on both one surface and the opposite surface (both surfaces).

  The material of the metal layer is preferably copper, aluminum, silver or an alloy containing one or more metals selected from these. Of these, copper or a copper alloy is preferable from the viewpoint of having superior conductivity. The metal layer is preferably made of a metal foil, more preferably a copper foil, because the material is easy to handle, can be easily formed, and is excellent in economy. When providing a metal layer on both surfaces of an insulating layer, the material of these metal layers may be the same and may differ.

  The thickness of the metal layer is preferably 1 to 70 μm, more preferably 3 to 18 μm.

The laminate can be manufactured by providing a metal layer on the surface of the insulating layer.
As a method of providing a metal layer, a method of fusing a metal foil to the surface of the insulating layer, a method of adhering the metal foil to the surface of the insulating layer with an adhesive, a plating method, a screen printing method or a sputtering method on the surface of the insulating layer Can be exemplified by a method of coating with metal powder or metal particles.
When the insulating layer is a laminate of a plurality of insulating base materials, the insulating layer can be obtained, for example, by hot pressing the plurality of insulating base materials and fusing them together.

FIG. 1 is a schematic cross-sectional view for explaining a method of manufacturing a laminated board including a laminate in which a plurality of insulating base materials are laminated as an insulating layer. The laminated board 1 shown here uses insulating base materials 11, 12, 13 and 14.
First, as shown to Fig.1 (a), the insulating base materials 11, 12, 13, and 14 are arrange | positioned in these thickness directions in this order. Here, in order to make it easy to see, the insulating base materials and the like are shown separated from each other, but they are all arranged in a stacked manner at the time of hot pressing.

  Then, among the four insulating base materials, the metal plate 91 and the cushioning material 92 are arranged in this order on the insulating base materials 11 and 14 that are located on the outermost sides (one side does not contact the insulating base material) when they are overlapped. The four insulating base materials are sandwiched between the metal plate 91 and the cushion material 92, and are heated and pressed by pressing with a hot platen or the like from the cushion material 92 side as indicated by an arrow. Here, the metal plate 91 is used in order not to damage the surface of the pressed object to be contacted (here, the insulating base materials 11 and 14), and is made of a material such as stainless steel (SUS) or aluminum, It is sufficient that the contact surface with the object to be pressed is smooth. The cushion material 92 is preferably made of a heat-resistant material such as aramid resin; carbon fiber; non-woven fabric of inorganic fiber such as alumina fiber.

The heating press is preferably performed under vacuum conditions, for example, under a reduced pressure of 0.5 kPa or less.
Other conditions for the hot press may be adjusted as appropriate according to the type of the insulating base material and the like, and are not particularly limited, but are preferably adjusted so that the surface smoothness of the laminate is good.
For example, the heating temperature is preferably adjusted according to the temperature at the time of the heat treatment when the heat treatment after the solvent removal is performed at the time of producing the insulating base material, and the maximum temperature at the time of the heat treatment The temperature is preferably higher than T _max (° C.), and more preferably 5 ° C. higher than T _max . The upper limit of the heating temperature at the time of hot pressing may be set so as to be lower than the decomposition temperature of the liquid crystal polyester used, but is preferably a temperature that is 30 ° C. lower than the decomposition temperature. The decomposition temperature of the liquid crystal polyester can be measured by a known method such as thermal weight loss analysis.
Moreover, it is preferable that the pressure at the time of a hot press is 1-30 MPa, and it is preferable that time is 5 to 60 minutes.

  Next, among the stacked insulating base materials, the metal layer 15 is provided on the surface of the insulating base material 11 located on the outermost side, and the metal layer 16 is provided on the surface of the insulating base material 14, as shown in FIG. Thus, the laminated plate 1 is obtained. The laminated insulating base materials 11, 12, 13 and 14 constitute an insulating layer 10.

  When the metal layers 15 and 16 are provided by fusing the metal foil to the insulating base materials 11 and 14 as described above, as shown in FIG. The metal foil 15 ′ is disposed so as to face the surface that does not contact (downward surface in the drawing), and the metal foil faces the surface that does not contact the other insulating base material (upward surface in the drawing). 16 'is disposed, and the insulating base materials 11, 12, 13, and 14 and the metal foils 15' and 16 'are simultaneously heated and pressed, and the metal layer 15 is transferred from the metal foil 15' and the metal layer 16 is transferred from the metal foil 16 '. Are preferably formed. In this case, heat pressing may be performed by the same method as described with reference to FIG. 1 except that the metal foils 15 ′ and 16 ′ are arranged. Thus, at the time of heat-pressing the insulating base material, the metal foil is further superimposed on the surfaces of the two outermost insulating base materials when they are overlapped, and the metal foil and the plurality of insulating base materials are hot-pressed. Thus, the metal layer can be provided simultaneously.

  In the case where the insulating base materials 11 and 14 are coated with metal powder or metal particles and the metal layers 15 and 16 are provided, it is preferable to apply a plating method, and to apply an electroless plating method or an electrolytic plating method. More preferred. In order to further improve the characteristics of the metal layers 15 and 16, it is preferable to heat-treat the metal layers 15 and 16 formed by plating, and the conditions for the heat treatment at this time are the same as the conditions for the heat press. It's okay.

  As described above, the metal layer is formed at the same time as or after the heat pressing of the insulating base material.

  Here, as the laminated plate, the metal layer 15 is provided on the surface of the insulating base material 11 and the metal layer 16 is provided on the surface of the insulating base material 14, but either of the metal layers 15 and 16 is shown. Either of them may be a laminated plate, and the configuration of the laminated plate may be appropriately selected according to the purpose.

  At the time of heat-pressing the insulating base material, the insulating base materials 11, 12, 13 and 14 are arranged in this order in the thickness direction as one structural unit, and this structural unit is interposed via the metal plate 91. A plurality of insulating layers (insulating layer 10 shown in FIG. 1B) can be formed at the same time by arranging a plurality of layers in the thickness direction and performing heat pressing. FIG. 3 is a schematic cross-sectional view for explaining a method of simultaneously forming a plurality of insulating layers by applying the method described with reference to FIG. 1, and FIG. 4 is described with reference to FIG. It is a schematic sectional drawing for demonstrating the method of forming a several insulating layer simultaneously by applying a method. When the metal foil is also heated and pressed at the same time, as shown in FIG. 4, the metal foil 15 ′, the insulating base materials 11, 12, 13, and 14 and the metal foil 16 ′ are arranged in this order in the thickness direction. What is necessary is just to arrange | position several this structural unit further in the thickness direction through the metal plate 91 as what is made into one structural unit. 3 and 4 exemplify the case where the number of the structural units is 3, the number of the structural units is not limited to this, and as long as there is no problem in performing the heat press, 2 Any number is acceptable as long as it is above.

  Up to this point, the case where there are a plurality of insulating base materials constituting the insulating layer has been described. However, in the case of a single insulating base material, in the above manufacturing method, instead of the plurality of insulating base materials, a single insulating base material is used. A laminated board can be manufactured similarly by omitting the operation of heating and pressing a plurality of insulating substrates using a substrate.

The laminated board according to the present invention has sufficient rigidity suitable for chip mounting because the insulating layer contains inorganic cloth and liquid crystal polyester, and the insulating layer has a thickness of 150 to 300 μm. Have good flexibility. The rigidity of a laminated board can be evaluated by the bending elastic modulus of a laminated board or an insulating base material, for example.
Then, the COF is obtained by patterning the metal layer of the laminated plate into a desired pattern by etching or the like.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. However, the present invention is not limited to the following examples. In addition, the flow start temperature of liquid crystalline polyester was measured with the following method.

(Measurement of flow start temperature of liquid crystal polyester)
Using a flow tester (manufactured by Shimadzu Corp., CFT-500 type), about 2 g of liquid crystalline polyester was filled into a cylinder equipped 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 / cm ^2). The liquid crystal polyester was melted while being heated at a rate of 4 ° C./min under a load of 4), extruded from a nozzle, and a temperature showing a viscosity of 4800 Pa · s (48000 poise) was measured.

<Manufacture of liquid crystal polyester liquid composition>
[Production Example 1]
(Manufacture of liquid crystal polyester)
A reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser was charged with 6-hydroxy-2-naphthoic acid (1976 g, 10.5 mol) and 4-hydroxyacetanilide (1474 g, 9. 75 mol), isophthalic acid (1620 g, 9.75 mol) and acetic anhydride (2374 g, 23.25 mol) were charged, and the gas in the reactor was sufficiently replaced with nitrogen gas, followed by stirring under a nitrogen gas stream. The temperature was raised from room temperature to 150 ° C. over 15 minutes, and this temperature (150 ° C.) was maintained and refluxed for 3 hours.
Next, while distilling off the by-product acetic acid to be distilled off and unreacted acetic anhydride, the temperature was raised to 300 ° C. over 170 minutes, and the time at which an increase in torque was observed was regarded as the reaction end time. The contents were removed. The contents were cooled to room temperature, and the resulting solid was pulverized with a pulverizer to obtain a liquid crystal polyester powder having a relatively low molecular weight. The flow starting temperature of this liquid crystal polyester powder was 235 ° C. This liquid crystal polyester powder was subjected to solid phase polymerization by heat treatment at 223 ° C. for 3 hours in a nitrogen gas atmosphere. The flow starting temperature of the liquid crystal polyester after solid phase polymerization was 270 ° C.

(Manufacture of liquid crystal polyester liquid composition)
The obtained liquid crystal polyester (2200 g) was added to N, N-dimethylacetamide (DMAc) (7800 g) and heated at 100 ° C. for 2 hours to obtain a liquid crystal polyester liquid composition (liquid crystal polyester solution). Using a B-type viscometer “TVL-20 type” (rotor No. 21, rotation speed 5 rpm) manufactured by Toki Sangyo Co., Ltd., the viscosity of this liquid crystal polyester liquid composition was measured at 23 ° C. and found to be 0.32 Pa. . s (320 cP).

<Manufacture of COF laminates>
[Example 1]
A laminated board was manufactured by the manufacturing method described with reference to FIGS. More specifically, it is as follows.
(Manufacture of insulating base materials)
A glass cloth (manufactured by Arisawa Manufacturing Co., Ltd., thickness 45 μm, IPC name 1078) was immersed in the liquid crystal polyester liquid composition obtained in Production Example 1 for 1 minute at room temperature, and then the solvent was evaporated using a hot air dryer. It was made to dry and the insulating base material which is a liquid crystal polyester impregnation base material was obtained.

(Insulation substrate heat treatment)
The obtained insulating base material was heat-treated at 290 ° C. for 3 hours in a nitrogen gas atmosphere using a hot air dryer.

(Manufacture of laminated sheets for COF)
Aramid cushion material (made by Ichikawa Technofabrics Co., Ltd., thickness 3 mm), SUS304 plate (thickness 5 mm), copper foil for spacer (“3EC-VLP” made by Mitsui Mining & Smelting Co., Ltd., thickness 18 μm), copper for lamination Foil ("CF-T9D-SV" manufactured by Fukuda Metals Co., Ltd., thickness 12 [mu] m), three insulating substrates, copper foil for lamination ("CF-T9D-SV" manufactured by Fukuda Metals Co. Ltd., thickness 12 [mu] m), spacer Copper foil ("3EC-VLP" manufactured by Mitsui Mining & Smelting Co., Ltd., thickness 18 μm) and SUS304 plate (thickness 5 mm) are stacked in this order, and further, an aramid cushion material (manufactured by Ichikawa Technofabrics Co., Ltd., thickness 3 mm) ). And in this state, using a high-temperature vacuum press (“KVHC-PRESS” manufactured by Kitagawa Seiki Co., Ltd., length 300 mm, width 300 mm), heat press for 20 minutes under conditions of 340 ° C. and 5 MPa under a reduced pressure of 0.2 kPa. As a result, a laminated board for COF, which is a multilayer insulating substrate with copper foil, was obtained. Table 1 shows the main components of the obtained COF laminate. In Table 1, “LCP” means liquid crystal polyester.

[Example 2]
As shown in Table 1, a COF laminate was obtained in the same manner as in Example 1, except that four insulating substrates were used instead of three.

[Example 3]
As shown in Table 1, a COF laminate was obtained in the same manner as in Example 1 except that five insulating substrates were used instead of three.

[Comparative Example 1]
As shown in Table 1, a COF laminate was obtained in the same manner as in Example 1 except that one insulating substrate was used instead of three.

[Comparative Example 2]
As shown in Table 1, a COF laminate was obtained in the same manner as in Example 1 except that two insulating substrates were used instead of three.

[Comparative Example 3]
As shown in Table 1, a COF laminate was obtained in the same manner as in Example 1 except that six insulating substrates were used instead of three.

[Comparative Example 4]
(Manufacture of insulating base materials)
The liquid crystal polyester liquid composition obtained in Production Example 1 was cast-coated on a matte surface of copper foil (“CF-T9D-SV” manufactured by Fukuda Metals Co., Ltd., thickness 12 μm), and then in a nitrogen gas atmosphere, 290 Heat treatment was performed at 0 ° C. for 3 hours. Next, the copper foil was etched away to obtain an insulating base material that was a single-layer liquid crystal polyester film (hereinafter referred to as “liquid crystal polyester film (1)”). Further, an insulating base material that is a single-layer liquid crystal polyester film (hereinafter referred to as “liquid crystal polyester film (2)”) is obtained in the same manner except that the temperature of the heat treatment is 310 ° C. instead of 290 ° C. Obtained. As a result of measuring the melting points of the liquid crystal polyester films (1) and (2) by differential scanning calorimetry, they were 335 ° C. and 347 ° C., respectively.

(Manufacture of laminated sheets for COF)
Aramid cushion material (made by Ichikawa Technofabrics Co., Ltd., thickness 3 mm), SUS304 plate (thickness 5 mm), copper foil for spacer (“3EC-VLP” made by Mitsui Mining & Smelting Co., Ltd., thickness 18 μm), copper for lamination Foil (“CF-T9D-SV” manufactured by Fukuda Metals Co., Ltd., thickness 12 μm), liquid crystal polyester film (2), liquid crystal polyester film (1), liquid crystal polyester film (1), liquid crystal polyester film (2), copper for lamination Foil ("CF-T9D-SV" manufactured by Fukuda Kinzoku Co., Ltd., thickness 12 [mu] m), copper foil for spacers ("3EC-VLP" manufactured by Mitsui Kinzoku Mining Co., Ltd., 18 [mu] m thick), and SUS304 plate (thickness 5 mm) The aramid cushion material (made by Ichikawa Technofabrics Co., Ltd., thickness: 3 mm) was further placed thereon. And in this state, using a high-temperature vacuum press (“KVHC-PRESS” manufactured by Kitagawa Seiki Co., Ltd., length 300 mm, width 300 mm), heat press for 20 minutes under conditions of 340 ° C. and 5 MPa under a reduced pressure of 0.2 kPa. As a result, a laminated board for COF, which is a multilayer insulating substrate with copper foil, was obtained. Table 1 shows the main components of the obtained COF laminate.

<Evaluation of laminated sheet for COF>
(Evaluation of flexural modulus)
About the COF laminated board obtained by each said Example and comparative example, the bending elastic modulus was measured by the 3 point | piece bending test. That is, after removing the copper foil of the COF laminate by etching, three test pieces cut into strips having a width of 10 mm were produced, and the distance between the lower fulcrums was “16 × insulation base” for each test piece. The position was adjusted so that the thickness of the material (mm) +6.4 mm ”, and the flexural modulus was measured at a speed of 0.5 mm / min. The results are shown in Table 1.

(Evaluation of flexibility)
When the COF laminates obtained in each of the above examples and comparative examples are cut into a size of 1 cm in width and 5 cm in length to be a test piece, and are bent five times in the same direction with both ends in the longitudinal direction. From the shape of the test piece, the flexibility was evaluated according to the following criteria. The results are shown in Table 1.
(Double-circle): The both ends of a test piece can be made to contact and a bending location does not have distortion.
○: Both ends of the test piece can be brought into contact with each other, but the bent portion is distorted.
X: When both ends of the test piece are brought into contact with each other, the test piece is broken.

As is clear from the evaluation results, in the laminates of Examples 1 to 3, the insulating layer uses a liquid crystal polyester-impregnated base material as the insulating base material, and the thickness of the insulating layer is within a predetermined range. And had sufficient rigidity and flexibility.
On the other hand, in the laminates of Comparative Examples 1 and 2, the insulating layer was a liquid crystal polyester-impregnated base material as an insulating base material, but the insulating layer was too thin and the rigidity was too low. The flexural modulus could not be measured. Further, in the laminated board of Comparative Example 3, the insulating layer similarly used a liquid crystal polyester-impregnated base material as the insulating base material, but the insulating layer was thick and the flexibility was insufficient. Moreover, since the laminated board of the comparative example 4 used the liquid crystalline polyester film as an insulating base material, the rigidity was too low and the bending elastic modulus was not able to be measured.

  The present invention can be used for COF in the field of microelectronics.

  DESCRIPTION OF SYMBOLS 1 ... COF laminated board, 10 ... Insulating layer, 11, 12, 13, 14 ... Insulating base material, 15, 16 ... Metal layer, 15 ', 16' ... Metal foil, 91 ... Metal plate, 92 ... Cushion material

Claims (6)

  A COF laminate comprising an insulating layer containing inorganic cloth and liquid crystal polyester and having a thickness of 150 to 300 μm, and a metal layer provided on at least one surface of the insulating layer.   2. The COF according to claim 1, wherein the insulating layer is formed by laminating a plurality of insulating base materials, and the insulating base material is obtained by impregnating the inorganic cloth with the liquid crystal polyester. Laminated board.   The COF laminate according to claim 1 or 2, wherein the inorganic cloth is a glass cloth. The said liquid crystalline polyester has a repeating unit represented by following General formula (1), (2) and (3), The laminated sheet for COF as described in any one of Claims 1-3 characterized by the above-mentioned.
(1) —O—Ar ¹ —CO—
(2) —CO—Ar ² —CO—
(3) ^-X-Ar 3 -Y-
(In the formula, Ar ¹ is a phenylene group, a naphthylene group or a biphenylylene group; Ar ² and Ar ³ are each independently a phenylene group, a naphthylene group, a biphenylylene group or a group represented by the following general formula (4): Yes; X and Y are each independently an oxygen atom or imino group; one or more hydrogen atoms in Ar ¹ , Ar ² and Ar ³ are each independently substituted with a halogen atom, an alkyl group or an aryl group May be.)
(4) -Ar ⁴ -Z-Ar ^5-
(In the formula, Ar ⁴ and Ar ⁵ are each independently a phenylene group or a naphthylene group; Z is 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 general formula (1) of 30 to 80 mol% and a repeating unit represented by the general formula (2) based on the total amount of all repeating units constituting the liquid crystalline polyester. The laminate for COF according to claim 4, wherein 10 to 35 mol% and 10 to 35 mol% of the repeating unit represented by the general formula (3) are contained.   6. The COF laminate according to claim 4, wherein, in the general formula (3), X and / or Y is an imino group.

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