JP4830686B2 - Metal foil-clad laminate and method for producing the same - Google Patents

Description

  The present invention relates to a metal foil-clad laminate used for a printed wiring board for mounting a light emitting diode (LED) and a method for manufacturing the same. The printed wiring board for LED mounting using the metal foil-clad laminate obtained in the present invention has high heat resistance, high light reflectance in the ultraviolet light region and visible light region, and further heat treatment and light irradiation. It has a feature that there is little decrease in light reflectance due to processing.

Conventionally, as a printed wiring board for LED mounting, an epoxy resin containing titanium dioxide is impregnated into a glass woven fabric, and then heat-cured laminate (see, for example, Patent Document 1), in addition to titanium dioxide, alumina Laminate using epoxy resin containing selenium (see, for example, Patent Document 2)
Etc. are known. Although these epoxy resin laminates according to the prior art have a satisfactory level of reflectivity at the laminate stage, the heat treatment in the manufacturing process of the printed wiring board and the LED mounting process, or during use after LED mounting Due to heating and light irradiation, the decrease in reflectivity becomes large and the heat resistance of the laminated plate is low, and deformation occurs due to heat generation during use after LED mounting, and it is used as a light-emitting element also called a chip LED. In such a case, there is a concern about a decrease in reliability, and further improvement is necessary.

JP-A-10-202789 Japanese Patent Laid-Open No. 2003-60321

  The object of the present invention is to solve the above-mentioned problems, high heat resistance, high light reflectance in the ultraviolet light region and visible light region, and light reflection by heat treatment or light irradiation treatment. An object of the present invention is to provide a metal foil-clad laminate used for a printed wiring board for LED mounting, which has a low rate reduction.

(1)

(2) As a result of various studies for solving such problems, the present inventors have used a specific polyimide resin layer as the adhesive layer of the metal foil in the metal foil-clad laminate, and a thermosetting resin containing titanium dioxide. Combined with the composition layer, it has high heat resistance, high light reflectance in the ultraviolet light region and visible light region, and less decrease in light reflectance due to heat treatment or light irradiation treatment, for LED mounting The present inventors have found that a printed wiring board can be obtained and have reached the present invention. That is, the present invention is a metal foil-clad laminate in which a metal foil is bonded to a thermosetting resin composition layer comprising a thermosetting resin composition and a substrate, and the adhesive layer of the metal foil is represented by the formula (1). Or a repeating unit represented by the formula (1) and a repeating unit represented by the formula (2), wherein the ratio of the repeating unit of the formula (1) is 50 mol% of all repeating units. It is a polyimide resin layer which is the above, and the thermosetting resin composition is a metal foil-clad laminate which is a thermosetting resin composition containing titanium dioxide, preferably, the thickness of the polyimide resin layer is 1 A metal foil-clad laminate having a titanium dioxide content of 10 to 100 parts by weight with respect to 100 parts by weight of the resin component of the thermosetting resin composition, and more preferably The curable resin composition comprises a bisphenol A novolac type epoxy resin and an alicyclic energy. It is a thermosetting resin composition containing a xy resin, and is a thermosetting resin composition containing a cyanate ester compound and / or an acid anhydride. More preferably, the metal foil-clad laminate is a metal foil. A metal foil-clad laminate obtained by combining a resin composite metal foil having the polyimide resin layer formed on one side thereof and a prepreg comprising the thermosetting resin composition and a base material, and laminating under heating and pressure. It is a manufacturing method of a board.

(1)

(2)

  The metal foil-clad laminate obtained by the present invention has high heat resistance, high light reflectance in the ultraviolet light region and visible light region, and little reduction in light reflectance due to heat treatment or light irradiation treatment. Therefore, it is preferably used for a printed wiring board for LED mounting.

(1)

で表される繰り返し単位、又は上記式(1)で表される繰り返し単位と下記式(2)：

(2)
で表される繰り返し単位からなり、式(1)で表される繰り返し単位の割合が全繰り返し単位の50モル％以上、好ましくは70モル％以上、より好ましくは80モル％以上である。ポリイミドＡは、ブロックコポリマーあるいはランダムコポリマーのどちらでも良い。 The polyimide resin used for the polyimide resin layer in the metal foil-clad laminate of the present invention (hereinafter appropriately referred to as polyimide A) is represented by the following formula (1):

(1)

Or a repeating unit represented by the above formula (1) and the following formula (2):

(2)
The ratio of the repeating unit represented by the formula (1) is 50 mol% or more, preferably 70 mol% or more, more preferably 80 mol% or more of all repeating units. Polyimide A may be either a block copolymer or a random copolymer.

  Polyimide A is a reaction of 1,2,4,5-cyclohexanetetracarboxylic acid, 1,2,4,5-cyclohexanetetracarboxylic dianhydride, 1,2,4,5-cyclohexanetetracarboxylic acid esters, etc. It can be obtained by reacting at least one tetracarboxylic acid component selected from functional derivatives with at least one diamine component selected from diamines and reactive derivatives thereof. As the tetracarboxylic acid component, 1,2,4,5-cyclohexanetetracarboxylic dianhydride is preferable. A tetracarboxylic acid component containing an isomer can also be applied.

  Examples of the diamine component include diamine, diisocyanate, and diaminodisilane, and diamine is preferable. The diamine component for forming the repeating unit of the above formula (1) is 2,2-bis [4- (4-aminophenoxy) phenyl] propane and a reactive derivative thereof, and the repeating unit of the above formula (2) The diamine component for forming is m-xylylenediamine and its reactive derivatives.

  Polyimide A is produced by reacting the tetracarboxylic acid component with respect to 1 mol of the diamine component, preferably 0.66 to 1.5 mol, more preferably 0.9 to 1.1 mol, and still more preferably 0.97 to 1.03 mol. The reaction time is preferably 2 to 12 hours, and the reaction temperature is preferably 180 to 205 ° C.

  Usually, the molecular terminal of the polyimide A is an amino group, a carboxyl group, or a carboxylic anhydride group. By reacting a compound having a carboxylic acid anhydride group or amino group at the molecular end, the functional group at the molecular end is reduced as much as possible, or an intentionally functional group such as an amino group or a carboxyl group at the molecular end. Groups and other substituents can be introduced. In order to reduce the water absorption rate of the printed wiring board to be obtained, a substituent having a small polarity (substituent having no functionality) may be introduced at the molecular end.

  Polyimide A is usually produced as an organic solvent solution. The organic solvent is not particularly limited. For example, N-methyl-2-pyrrolidone, N, N-dimethylacetamide, N, N-diethylacetamide, N, N-dimethylformamide, N, N-diethylformamide, N-methyl Caprolactam, hexamethylphosphoramide, tetramethylenesulfone, dimethylsulfoxide, m-cresol, phenol, p-chlorophenol, 2-chloro-4-hydroxytoluene, diglyme, triglyme, tetraglyme, dioxane, γ- Butyrolactone, dioxolane, cyclohexanone, cyclopentanone, etc. can be used, and two or more of them may be used in combination, and in particular, N-methyl-2-pyrrolidone (hereinafter referred to as NMP), N, N-dimethylacetamide, γ- It is preferable to use butyrolactone alone or in combination. The organic solvent is used in such an amount that the polyimide A concentration in the obtained organic solvent solution is preferably 1 to 50% by weight, more preferably 5 to 40% by weight. In the case of production by solution polymerization, a poor solvent such as hexane, heptane, benzene, toluene, xylene, chlorobenzene, o-dichlorobenzene and the like can be used together with the above solvent to such an extent that the polymer does not precipitate.

  As a method for producing polyimide A, a solution polymerization method, a polyamic acid solution is prepared, a film is formed, an imidization method, a salt or imide oligomer such as a tetraester dianhydride half ester salt is obtained, and a solid solution is obtained. It can be produced by a method of performing phase polymerization, a method of reacting tetracarboxylic dianhydride and diisocyanate, or other conventionally known methods. You may use each method together. The reaction between the tetracarboxylic acid component and the diamine component may be performed in the presence of a conventionally known catalyst such as an acid, a tertiary amine, or an acid anhydride. Among these methods, a solution polymerization method is preferred because an organic solvent solution of polyimide A can be obtained directly.

  As a solution polymerization method for producing polyimide A, a mixture containing a diamine component, an organic solvent, and, if necessary, a catalyst is stirred at 10 to 600 rpm to obtain a uniform solution, which is maintained at a temperature of 30 to 90 ° C. Add acid component and catalyst as needed, or stir the mixture containing tetracarboxylic acid component, organic solvent and catalyst as needed at 10-600rpm to make a homogeneous solution, this temperature 30-90 ° C And after adding the diamine component and, if necessary, the catalyst, the temperature is raised to 160 to 230 ° C., preferably 180 to 205 ° C. over 0.1 to 6 hours. This temperature depends on the boiling point of the organic solvent used. While collecting components to be removed from the reaction system, the temperature is kept substantially constant for 0.5 to 24 hours, preferably 2 to 12 hours. Thereafter, if necessary, a method of further adding an organic solvent and cooling to an appropriate temperature is exemplified.

  This solution polymerization is performed using trimethylamine, triethylamine, tripropylamine, tributylamine, triethanolamine, N, N-dimethylethanolamine, N, N-diethylethanolamine, triethylenediamine, N-methylpyrrolidine, N-ethylpyrrolidine, N The reaction may be performed in the presence of at least one catalyst selected from tertiary amine compounds such as -methylpiperidine, N-ethylpiperidine, imidazole, pyridine, quinoline, and isoquinoline. When used, the amount of the catalyst used is preferably 0.1 to 100 mol%, more preferably 1 to 10 mol% of the tetracarboxylic acid component.

  The number average molecular weight of the polyimide A used in the present invention is 3,000 to 100,000. If it is less than 3000, the strength of the polyimide resin itself is weak and a printed wiring board exhibiting sufficient adhesive strength cannot be obtained. When it exceeds 100000, the organic solvent solution becomes highly viscous, and when it is applied to a metal foil or the like, a large dilution is required, which makes handling difficult. In order to improve the adhesive strength while maintaining the balance of various properties of the polyimide resin, the number average molecular weight is preferably 3000 to 70000.

  In the metal foil-clad laminate of the present invention, the thickness of the polyimide resin layer is not particularly limited. However, when the thickness is increased, the drying in the heating process at the time of forming the polyimide resin layer becomes insufficient and the cost increases. 1 to 10 μm is preferable, and 2 to 8 μm is more preferable.

  The metal foil used for the metal foil-clad laminate of the present invention is not particularly limited as long as it is a known copper foil or aluminum foil used for printed wiring boards, but preferably an electrolytic copper foil, a rolled copper foil, and these A copper alloy or the like, or a soft aluminum foil, a hard aluminum foil or the like is used. These metal foils that have been subjected to a known surface treatment such as nickel or cobalt treatment can also be used. The thickness of the metal foil is not particularly limited, but is preferably 35 μm or less when a copper foil is used, and 100 μm or less when an aluminum foil is used.

  In the metal foil-clad laminate of the present invention, the method of using the polyimide resin layer as an adhesive layer of the metal foil is not particularly limited. Preferably, an organic solvent solution of polyimide A obtained by the above-described production method is used as a metal. A method of preparing a resin composite metal foil by coating on one side of the foil and drying, and using it integrally with a thermosetting resin composition layer (prepreg) described later is used.

As the titanium dioxide to be contained in the thermosetting resin composition used in the present invention, rutile type and anatase type titanium dioxide are used. The average particle diameter of titanium dioxide is preferably 5 μm or less, more preferably 0.5 μm or less, and it is also possible to use a suitable combination of those having a changed particle size distribution or average particle diameter. is there. The titanium dioxide is preferably titanium dioxide having a coating layer formed on the surface, and the coating layer is treated with SiO ₂ , Al ₂ O ₃ , ZrO ₂ or ZnO, and the coating layer further comprises SiO ₂ , Al ₂ O ₃ , Titanium dioxide which is obtained by treatment with ZrO ₂ or ZnO followed by polyol treatment, silane coupling agent treatment or amine treatment is particularly preferred. As a method of stirring and dispersing the resin composition of titanium dioxide, it may be carried out in a stirring tank equipped with a stirrer having an appropriate stirring ability, or an apparatus for mixing such as a ball mill or a bead mill, or a revolution or rotation. It can also be carried out using a mixing device of the type.

  Content of titanium dioxide is 10-100 weight part with respect to 100 weight part of total amounts of the resin component of a thermosetting resin composition, Preferably it is 25-70 weight part. When the content of titanium oxide is less than the above range, the light reflectance is insufficient, and it is not suitable for a printed wiring board for LED mounting. When it is more than the above range, the insulating layer becomes too hard, and the printed wiring board or chip Cracks and chips are easily generated during transportation during the manufacture of the LED, and in addition, there is a problem that a drill bit or a dicing blade cannot be broken or processed in mechanical drill processing on a printed wiring board or dicing processing on a chip LED.

  In addition to titanium dioxide, the thermosetting resin composition used in the present invention includes, as an inorganic filler, natural silica, synthetic silica, talc, calcined talc, zinc oxide, magnesium oxide, zirconium oxide, aluminum hydroxide, etc. It is also possible to use known inorganic fillers.

  The thermosetting resin composition used in the present invention is not particularly limited as long as it is a known resin composition used for various printed wiring board materials, but bisphenol A novolac type epoxy resin and alicyclic epoxy resin are used. The thermosetting resin composition to contain is preferable. The bisphenol A novolac type epoxy resin is not particularly limited as long as it is an epoxidized product of novolak resin obtained from bisphenol A and formaldehyde. The preferable content of the bisphenol A novolac type epoxy resin is 65 to 95% by weight of the epoxy resin component in the resin composition, more preferably 70 to 90% by weight. When the content of the bisphenol A novolac type epoxy resin is less than the above range, discoloration of the obtained copper-clad laminate due to heat treatment or light irradiation treatment is slightly increased, and heat resistance is also lowered.

  The alicyclic epoxy resin suitably used for the thermosetting resin composition used in the present invention is not particularly limited as long as it is an epoxidized product of a known alicyclic compound. Specifically, well-known books such as “Review Epoxy Resin” (published / edited: Epoxy Resin Technology Association, published in 2003) and those described in the literature are used. Typical examples including specific products include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate {trade names: Celoxide 2021, Celoxide 2021A, Celoxide 2021P (above Daicel Chemical Industries ( Co., Ltd.), ERL4221, ERL4221D, ERL4221E (manufactured by Dow Chemical Japan Co., Ltd.)}, bis (3,4-epoxycyclohexylmethyl) adipate (trade name: ERL4229 (manufactured by Dow Chemical Japan Co., Ltd.), EXA7015 ( Dainippon Ink Chemical Co., Ltd.)}, 1-epoxyethyl-3,4-epoxycyclohexane, limonene diepoxide, Celoxide 2081 (Daicel Chemical Industries, Ltd.), Epicoat YX8000, Epicoat YX8034, Epicoat YL7170 (or above) Japan Epoxy Resin Co., Ltd.), Celoxide 2081, Celoxide 3000, Epolide GT301, Epolide GT401, EHPE3150 (above Daicel Chemical Industries, Ltd.) It is also possible to use one or two or more kinds in appropriate mixture. Preferred cycloaliphatic epoxy resins include 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, bis (3,4-epoxycyclohexylmethyl) adipate, Epicoat YX8000, Epicoat YX8034, Epolide GT301, Epolide Examples include GT401 and EHPE3150. The content of the alicyclic epoxy resin is preferably 5 to 35% by weight, more preferably 10 to 30% by weight, based on the epoxy resin component in the resin composition. When the content of the alicyclic epoxy resin is less than the above range, discoloration due to heat treatment or light irradiation treatment of the obtained copper-clad laminate is slightly increased, and when it is more than the above range, the heat resistance is reduced. To do.

  In the thermosetting resin composition used in the present invention, an epoxy resin other than the bisphenol A novolac type epoxy resin and the alicyclic epoxy resin can be used in combination as necessary. These epoxy resins include bisphenol A type epoxy resin, bisphenol E type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, biphenyl type epoxy resin, and naphthalene type. Epoxy resin, trifunctional phenol type epoxy resin, tetrafunctional phenol type epoxy resin, glycidyl ester type epoxy resin, phenol aralkyl type epoxy resin, biphenyl aralkyl type epoxy resin, naphthol aralkyl type epoxy resin, dicyclopentadiene type epoxy resin, or these And the like.

  The thermosetting resin composition used in the present invention preferably uses an epoxy resin. In this case, an amine compound, a phenol compound, a cyanate ester compound, an acid anhydride, or the like may be used in combination as a curing component. Although possible, cyanate ester compounds and / or acid anhydrides are particularly preferred.

  The cyanate ester compound suitably used for the thermosetting resin composition used in the present invention is not particularly limited as long as it is a compound having two or more cyanato groups in one molecule. Specifically, 1,3- or 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, bis (3,5-dimethyl-4-cyanatophenyl) methane, 1,3-, 1 , 4-, 1,6-, 1,8-, 2,6- or 2,7-dicyanatonaphthalene, 1,3,6-tricyanatonaphthalene, 4,4-dicyanatobiphenyl, bis (4- Anatophenyl) methane, 2,2-bis (4-cyanatophenyl) propane, 2,2-bis (3,5-dibromo-4-cyanatophenyl) propane, bis (4-cyanatophenyl) ether, bis (4-cyanatophenyl) thioether, bis (4-cyanatophenyl) sulfone, tris (4-cyanatophenyl) phosphite, tris (4-cyanatophenyl) phosphate, and various novolak resins and cyanogen halides Examples include cyanate ester compounds obtained by the above reaction, and it is possible to use one or two or more appropriately mixed. . Preferred cyanate compounds include 1,3- or 1,4-dicyanatobenzene, 1,3,5-tricyanatobenzene, bis (3,5-dimethyl-4-cyanatophenyl) methane, bis (4 -Dicyanatophenyl) methane, 2,2-bis (4-cyanatophenyl) propane, phenol novolac type cyanate ester. Content of a cyanate ester compound is 10-40 weight part with respect to 100 weight part of epoxy resins in a resin composition, Preferably, it is 15-35 weight part. When content of a cyanate ester compound is less than the said range, the heat resistance improvement effect of the obtained copper clad laminated board will reduce. When the amount is more than the above range, discoloration due to heat treatment / light irradiation treatment becomes large.

  Examples of the acid anhydride suitably used in the thermosetting resin composition used in the present invention include alicyclic acid anhydrides, aromatic acid anhydrides, aliphatic acid anhydrides, halogenated anhydrides, and the like. If it is acid anhydride of, it will not specifically limit. Specifically, known books such as “Review Epoxy Resin” (published / edited: Epoxy Resin Technology Association, published in 2003), and those described in the literature are used. Typical examples are maleic anhydride, phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methylnadic anhydride Cycloaliphatic tetrabasic acid anhydrides such as hydride, methyl nadic acid anhydride, etc. and Epicron B4400 (Dainippon Ink Chemical Co., Ltd.) and cyclohexane- And alicyclic dibasic acid anhydrides such as 1,3,4-tricarboxylic acid-3,4-anhydride. Preferred acid anhydrides include epiclone B4400, cyclohexane-1,3,4-tricarboxylic acid-3,4-anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, and hydrogenated methylnadic acid anhydride. . Content of an acid anhydride is 3-30 weight part with respect to 100 weight part of epoxy resins in a resin composition, Preferably, it is 5-25 weight part. When content of an acid anhydride is less than the said range, the discoloration-resistant improvement effect with respect to heat processing and light irradiation processing of the obtained copper clad laminated board will reduce. Moreover, when more than the said range, an unreacted acid anhydride becomes excess and chemical resistance falls.

  The thermosetting resin composition used in the present invention can be used in combination with a curing accelerator in order to adjust the curing rate as needed. These are not particularly limited as long as they are generally used as curing accelerators such as epoxy resins. Specific examples thereof include imidazoles and derivatives thereof, tertiary amines and the like.

  In the thermosetting resin composition used in the present invention, it is preferable to use a polydimethylsiloxane surfactant in combination. This polydimethylsiloxane-based surfactant is obtained by introducing an organic functional group into polydimethylsiloxane, such as polyether-modified polydimethylsiloxane, epoxy-modified polydimethylsiloxane, polyester-modified polydimethylsiloxane, alkyl-modified polydimethylsiloxane, amino acid. There are modified polydimethylsiloxane, carboxyl-modified polydimethylsiloxane, phenol-modified polydimethylsiloxane, methacryl-modified polydimethylsiloxane, and the like, which are used to uniformly disperse titanium dioxide as an inorganic filler in a resin composition. Specific product names include BYK-306, 307, 308, 310, 330, 333, 341, 344, etc. manufactured by Big Chemie Japan Co., Ltd., and SH-203, 230 manufactured by Toray Dow Corning Co., Ltd. 3764, 8400, 8700, SF-8410, 8416, 8419, 8422, FS-1265, and the like. The content of the polydimethylsiloxane surfactant is 0.005 to 0.5 parts by weight, preferably 0.01 to 0.2 parts by weight, with respect to 100 parts by weight of titanium dioxide.

As a base material used by this invention, the well-known thing used for various printed wiring board materials can be used. Examples thereof include inorganic fibers such as E glass, D glass, S glass, NE glass, T glass, and quartz, and organic fibers such as polyimide, polyamide, and polyester. It is also possible to use a combination of more than one. Examples of the shape include woven fabric and non-woven fabric. As the weaving method of the woven fabric, known ones such as plain weave, nanako weave and twill weave can be used. A treated glass woven fabric is preferably used. The thickness and weight of the substrate are not particularly limited, but a glass woven fabric having a thickness of 200 μm or less and a weight of 250 g / m ² or less is preferable.

  The manufacturing method of the prepreg used by this invention will not be specifically limited if it is a method by which the prepreg containing a thermosetting resin composition and a base material is obtained. For example, the glass woven fabric is impregnated or coated with the thermosetting resin composition, and then semi-cured by a method of heating for 1 to 30 minutes in a dryer at 100 to 200 ° C. to produce a prepreg. The method of doing is illustrated. The glass woven fabric content in the prepreg is preferably in the range of 25 to 75% by weight.

  When manufacturing the prepreg used by this invention, it is possible to mix | blend an organic solvent with a thermosetting resin composition as needed. The organic solvent is not particularly limited as long as it is compatible with a mixture of a bisphenol A novolac type epoxy resin and an alicyclic epoxy resin. Specific examples include ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, aromatic hydrocarbons such as benzene, toluene and xylene, amides such as dimethylformamide and dimethylacetamide, and the like.

The method for producing a metal foil-clad laminate of the present invention is a metal foil-clad laminate obtained by combining the resin composite metal foil and at least one prepreg and laminating them under heating and pressure. At this time, if necessary, another prepreg can be disposed under the prepreg and used. As the lamination molding conditions of the metal foil-clad laminate, the usual method for laminates for printed wiring boards can be applied. For example, a multistage press, a multistage vacuum press, a continuous molding, an autoclave molding machine, etc. are used. 300 ° C, pressure: ^{2 to} 100 kgf / cm ² , heating time: 0.1 to 5 hours are common, but from the viewpoints of uniform insulation layer thickness, removal of bubbles, etc., lamination molding is a vacuum of 70 mmHg or less. It is preferable to carry out below.

  The metal foil-clad laminate obtained by the above-mentioned method is known, for example, as “Printed Circuit Handbook” (published by Modern Science Co., Ltd., CF Combs Jr., edited by the Printed Circuit Society, published in 1991). The printed wiring board is processed in accordance with the literature and the method presented in the book on the manufacturing method of the printed wiring board. Specifically, drilling process by mechanical drilling or laser processing, electroless copper plating process, electrolytic copper plating process, pattern formation process by subtractive method, semi-additive method or additive method, solder resist process, external processing The printed wiring board is processed through a process, a cleaning process, and the like. Furthermore, LEDs are mounted on the printed wiring board thus obtained by a known method. Specifically, electrical connection between the LED element and the printed wiring board, such as cleaning with plasma, mounting of the LED element, curing of the mounting resin, wire bonding bonding, flip chip bonding, etc., LED element and electric connection portion It is processed into a light emitting element called a chip LED through processes such as protection (sealing) of the resin, curing of the protected resin, and individualization by dicing. The light-emitting element obtained in this way is subjected to normal conditions or a load such as heating and light irradiation, and then the reflectance of the surface is measured to evaluate its optical characteristics. For evaluation of optical properties as a metal-clad laminate, reflectivity is measured after applying a load such as heating or light irradiation in a normal state without processing the printed wiring board and the chip LED. It is.

Hereinafter, the present invention will be specifically described with reference to synthesis examples, examples, and comparative examples. “Parts” represents parts by weight.
(Synthesis Example 1)
In a 300 ml five-necked glass round bottom flask equipped with a stainless steel half-moon stirring blade, a nitrogen inlet tube, a Dean Stark fitted with a cooling tube, a thermometer, and a glass end cap, 2,2-bis [4- (4-Aminophenoxy) phenyl] propane 19.3 g (47 mmol), m-xylylenediamine 0.923 g (6.78 mmol), NMP 40 g, and triethylamine 0.26 g were stirred at 100 rpm in a nitrogen atmosphere to obtain a solution. . To this, 11.7 g (52.2 mmol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 7.8 g of NMP were added all at once, then heated with a mantle heater and the reaction system temperature was increased over about 20 minutes. Was raised to 200 ° C. The temperature inside the reaction system was maintained at 200 ° C. for 5 hours while collecting the components to be distilled off. Next, 72 g of N, N-dimethylacetamide was added, and the mixture was stirred at about 130 ° C. for about 30 minutes to obtain a uniform solution. The solution was cooled to 100 ° C. for about 10 minutes to obtain a polyimide solution having a solid content concentration of 20% by weight. The obtained polyimide solution was applied on a smooth glass plate coated with a very small amount of a release agent by a coater, and then heated on a hot plate at 100 ° C. for 1 hour to form a self-supporting film. After fixing the film peeled from the glass plate to the stainless steel mold with clips, it was left in a vacuum dryer at 200 ° C for 5 hours to remove the solvent almost completely (less than 1% by weight). Obtained. When the IR spectrum of this polyimide film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1772 and 1704 (cm ⁻¹ ). This polyimide had a number average molecular weight of 8,200, a weight average molecular weight of 73,000, a glass transition temperature of 253 ° C., and a water absorption of 2.2%.

(Synthesis Example 2)
In a five-neck glass round bottom flask similar to that used in Synthesis Example 1, 27.5 g (67.1 mmol) 2,2-bis [4- (4-aminophenoxy) phenyl] propane, 51 g γ-butyrolactone, Then, 0.336 g of triethylamine was stirred at 100 rpm in a nitrogen atmosphere to obtain a solution. To this, 14.9 g (66.4 mmol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride and 12 g of N, N-dimethylacetamide were added all at once, and then heated with a mantle heater for about 20 minutes. The temperature in the reaction system was increased to 180 ° C. The temperature in the reaction system was maintained at 180 ° C. for 3 hours while collecting the components to be distilled off. Next, after adding 96 g of N, N-dimethylacetamide, the mixture was stirred for about 30 minutes at a temperature of about 130 ° C. to obtain a homogeneous solution, and then cooled to 100 ° C. in about 10 minutes to obtain a polyimide solution having a solid content concentration of 20% by weight. A polyimide film was obtained in the same manner as in Synthesis Example 1 using the obtained polyimide solution. When the IR spectrum of this polyimide film was measured, characteristic absorption of an imide ring was observed at ν (C═O) 1774 and 1706 (cm ⁻¹ ). The number average molecular weight of this polyimide was 10,500, the weight average molecular weight was 99000, the glass transition temperature was 262 ° C., and the water absorption was 1.7%.

(Example 1)
The polyimide solution obtained in Synthesis Example 1 was applied to the mat surface of a 12μm thick electrolytic copper foil (JTC-LP foil, manufactured by Nikko Materials Co., Ltd.) using a reverse roll coating machine, under a nitrogen atmosphere. Then, after drying at 80 ° C. for 10 minutes, heating was carried out at 220 ° C. for 5 hours to prepare a resin composite copper foil A having a resin layer thickness of 5 μm. On the other hand, 20 parts of 2,2-bis (4-cyanatophenyl) propane is dissolved in methyl ethyl ketone, and bisphenol A novolac type epoxy resin (trade name: Epicron N865, manufactured by Dainippon Ink & Chemicals, Inc.) 60 parts and 20 parts of an alicyclic epoxy resin (trade name: ERL4221D, manufactured by Dow Chemical Japan Co., Ltd.) were added and uniformly dissolved and mixed. Furthermore, 0.025 part of zinc octylate and 0.02 part of surfactant (trade name: BYK-310, manufactured by Big Chemie Japan Co., Ltd.) were added, and after dissolution and mixing, titanium dioxide (trade name: CR-90, average particle size of 0.25). 70 parts of μm, manufactured by Ishihara Sangyo Co., Ltd. was added, and the mixture was uniformly stirred and mixed to obtain a varnish. This varnish was impregnated into a plain weave E glass woven fabric (trade name: 0634NW, manufactured by Arisawa Manufacturing Co., Ltd.) having a thickness of 50 μm and a weight of 48.5 g / m ² and dried at 150 ° C. for 8 minutes. 45% by weight of prepreg B was prepared. Two sheets of this prepreg B are stacked, and the above resin composite copper foil A is arranged on the upper and lower surfaces of the prepreg B, laminated and molded under a vacuum of 220 ° C., 35 kgf / cm ² , 30 mmHg or less for 2 hours, and an insulating layer thickness of 122 μm. A laminate was obtained. The evaluation results are shown in Table 1.

(Example 2)
The polyimide solution obtained in Synthesis Example 2 was further diluted with NMP to obtain a polyimide solution having a solid content of 15%. Apply this polyimide solution and apply it to the matte surface of 12μm thick electrolytic copper foil (3EC-VLP foil, Mitsui Mining & Smelting Co., Ltd.) using a reverse roll coating machine at 80 ° C in a nitrogen atmosphere. After drying for 10 minutes, it was heated at 220 ° C. for 5 hours to produce a resin composite copper foil C having a resin layer thickness of 3 μm. On the other hand, 15 parts of 2,2-bis (4-cyanatophenyl) propane was dissolved in a mixed solvent of methyl ethyl ketone and dimethylformamide, and bisphenol A novolac type epoxy resin (trade name: Epicoat 157S70, Japan Epoxy Resin Co., Ltd.) 70 parts) and alicyclic epoxy resin (trade name: Celoxide 2021P, manufactured by Daicel Chemical Industries, Ltd.) 10 parts were added and uniformly dissolved and mixed. In addition, cyclohexane-1,3,4-tricarboxylic acid-3,4-anhydride (Mitsubishi Gas Chemical Co., Ltd.) 5 parts, zinc octylate 0.03 parts, surfactant (trade name: BYK-341, Big Chemie ・(Japan Co., Ltd.) Add 0.05 parts, dissolve and mix, and then add 50 parts of titanium dioxide (trade name: CR-80, average particle size 0.25 μm, Ishihara Sangyo Co., Ltd.) Obtained. This varnish was impregnated into a plain weave E glass woven fabric (trade name: WEX570, manufactured by Nittobo Co., Ltd.) having a thickness of 30 μm and a weight of 31.5 g / m ² , and dried at 150 ° C. for 4 minutes. 42% by weight of prepreg D was prepared. Two sheets of this prepreg D were stacked, and the resin composite foil C was placed on the upper and lower surfaces thereof and laminated and formed in the same manner as in Example 1 to obtain a copper-clad laminate having an insulating layer thickness of 76 μm. The evaluation results are shown in Table 1.

Example 3
In Example 2, instead of 15 parts 2,2-bis (4-cyanatophenyl) propane, 5 parts cyclohexane-1,3,4-tricarboxylic acid-3,4-anhydride, 0.03 part zinc octylate, Bisphenol A type epoxy resin (trade name: Epicote 1001, manufactured by Japan Epoxy Resin Co., Ltd.) 20 parts, dicyandiamide 4 parts, 2-ethyl-4-methylimidazole 0.05 parts, and the same procedure as in Example 2, Prepreg E was produced. Two prepregs E are stacked, and the resin composite foil C prepared in Example 2 is placed on the upper and lower surfaces thereof, and the lamination molding is performed in the same manner as in Example 1 except that the temperature of the lamination molding is changed to 180 ° C. A copper clad laminate having an insulating layer thickness of 78 μm was obtained. The evaluation results are shown in Table 1.

Example 4
70 parts of bisphenol A novolac type epoxy resin (Epicoat 157S70) and 10 parts of alicyclic epoxy resin (EHPE3150, manufactured by Daicel Chemical Industries, Ltd.) were uniformly dissolved and mixed. Furthermore, cyclohexane-1,3,4-tricarboxylic acid-3,4-anhydride (Mitsubishi Gas Chemical Co., Ltd.) 20 parts, surfactant (BYK-341) 0.05 parts, 2-ethyl-4-methylimidazole 0.05 part was added, and after dissolution and mixing, 50 parts of titanium dioxide (CR-90) was added, and the mixture was uniformly stirred and mixed to obtain a varnish. This varnish was impregnated into a plain weave E glass woven fabric (trade name: 1031NT, manufactured by Arisawa Manufacturing Co., Ltd.) having a thickness of 100 μm and a weight of 109.5 g / m ² and dried at 150 ° C. for 6 minutes. A 37 wt% prepreg F was prepared. Two layers of this prepreg F are stacked, and the resin composite foil A prepared in Example 1 is arranged on the upper and lower surfaces thereof, and the layer molding is performed in the same manner as in Example 1 except that the temperature of the layer molding is changed to 180 ° C. A copper clad laminate having an insulating layer thickness of 225 μm was obtained. The evaluation results are shown in Table 1.

(Comparative Example 1)
Add 90 parts of bisphenol A type epoxy resin (Epicoat 1001), 10 parts of cresol novolac type epoxy resin (YDCN-704, manufactured by Tohto Kasei Co., Ltd.) and 3 parts of dicyandiamide in dimethylformamide, and mix uniformly. did. Furthermore, 0.02 part of a surfactant (BYK-341) was added, and after dissolution and mixing, 70 parts of titanium dioxide (CR-90) was added and stirred uniformly to obtain a varnish. The varnish was impregnated into a plain weave E glass woven fabric (0634NW) having a thickness of 50 μm and a weight of 48.5 g / m ² and dried at 150 ° C. for 12 minutes to prepare a prepreg G having a glass fabric content of 42% by weight. Two sheets of this prepreg G are stacked, and 12μm thick electrolytic copper foil (3EC-VLP foil) is placed on the top and bottom of the prepreg G, and then laminated for 2 hours at 180 ° C, pressure 40kgf / cm ² , and vacuum degree 30mmHg or less. A plate was made. The evaluation results are shown in Table 1.

(Comparative Example 2)
40 parts of bisphenol A type epoxy resin (Epicoat 1001), 30 parts of the same (Epicoat 828, manufactured by Japan Epoxy Resin Co., Ltd.), 30 parts of low molecular weight liquid rubber (CTBN1300 × 31, manufactured by Ube Industries, Ltd.), 2-ethyl 4-methylimidazole (manufactured by Shikoku Kasei Kogyo Co., Ltd.) was added with 100 parts of methyl ethyl ketone and stirred and dissolved at room temperature for 1 hour to obtain a varnish. This varnish was applied to the matte surface of electrolytic copper foil (LTC-LP foil) with a thickness of 12μm using a reverse roll coating machine, and heated and dried in a heating furnace at 150 ° C for 10 minutes to obtain a resin layer with a thickness of 7μm. An epoxy resin-based resin composite copper foil H was produced. Except that this resin composite copper foil H was used in place of the resin composite copper foil A, the same procedure was carried out as in Example 1 to produce a copper-clad laminate having an insulating layer thickness of 131 μm. The evaluation results are shown in Table 1.

(Comparative Example 3)
A 2-liter three-necked flask equipped with a stainless steel vertical stirring bar, a trap with a nitrogen inlet tube and a stopcock, and a reflux condenser equipped with a ball-mounted cooling tube was added to ethylene glycol bistrimellitate dianhydride. 164 g (400 mmol), 4,4′-diamino-3,3 ′, 5,5′-tetraethyldiphenylmethane 124 g (400 mmol), γ-valerolactone 4.0 g (40 mmol), pyridine 4.8 g (60 mmol), NMP 300 g, 20 g of toluene was added and heated at 180 ° C. for 3 hours to obtain a polyimide resin solution. The number average molecular weight of this polyimide resin was 31000, and the weight average molecular weight was 78000. This polyimide solution was used in place of the polyimide solution in Example 1 to prepare a resin composite copper foil having a resin layer thickness of 6 μm. Except that this resin composite copper foil was used in place of the resin composite copper foil A, the same procedure was carried out as in Example 1 to produce a copper clad laminate having an insulating layer thickness of 124 μm. The evaluation results are shown in Table 1.

(Measurement and evaluation method)
1) IR spectrum: Measured using JIR-WINSPEC50 manufactured by JEOL Ltd.
2) Molecular weight measurement: Measured by GPC (gel permeation chromatography) using NMP as a solvent and converted to the molecular weight of standard polystyrene.
3) Glass transition temperature: DSC-50 manufactured by Shimadzu Corporation was used, and the glass transition temperature at the midpoint glass transition temperature Tmg when the temperature was increased from 40 ° C. to 350 ° C. at a temperature increase rate of 10 ° C./min was defined as the glass transition temperature.
4) Water absorption rate: According to the method of IPC-TM-650 2.6.2.1, a 50.8 × 50.8 mm polyimide film was dried at 120 ° C. for 1 hour, and then the weight (W ₀ ) was measured. This film was immersed in distilled water at 23 ° C. for 24 hours to wipe off moisture on the surface, and then the weight (W ₁ ) was measured immediately.
Water absorption (%) = (W ₁ −W ₀ ) ÷ W ₀ × 100
5) Surface insulating layer thickness: According to JIS C6481, the thickness of the resin composite copper foil was measured at 5 points with a micrometer, and the value obtained by subtracting the nominal thickness of the copper foil from the average value.
6) Heat resistance: According to JIS C6481, the presence or absence of abnormal appearance change after heat treatment at 240 ° C. for 30 minutes was visually observed in a hot air dryer. (○: No abnormality, ×: Swelling and peeling occurred)
7) Reflectance: The copper-clad laminate was cut into a size of 50x50 mm with a dicing saw, and then the copper foil on the surface was removed by etching to obtain a measurement sample. The reflectance at 457 nm was measured for this measurement sample using a spectral whiteness photometer (manufactured by Tokyo Denshoku Co., Ltd .: ERP-80WX) based on JIS P8152. (average value of n = 5)
8) Reflectance after heating: The sample for measurement was heat-treated with a hot air dryer at 180 ° C. for 1 hour, and then the reflectance was measured in the same manner as the measurement of the reflectance. (average value of n = 5)
9) Reflectance after light irradiation: After the sample for measurement was irradiated with a blue light lamp of 420 nm and 15 W for 1000 hours, the reflectance was measured in the same manner as the measurement of the reflectance. (average value of n = 5)
10) Tg: After etching the copper foil on the surface of the copper clad laminate, the glass transition temperature was measured by the DMA method after cutting to a size of 15 × 40 mm with a dicing saw. (average value of n = 5)

Claims (6)

In a metal foil-clad laminate in which a metal foil is bonded to a thermosetting resin composition layer comprising a thermosetting resin composition and a substrate, the adhesive layer of the metal foil is a repeating unit represented by the formula (1) Or a polyimide resin comprising a repeating unit represented by the formula (1) and a repeating unit represented by the formula (2), wherein the ratio of the repeating unit of the formula (1) is 50 mol% or more of all repeating units. A metal foil-clad laminate, which is a layer and the thermosetting resin composition is a thermosetting resin composition containing titanium dioxide.

(1)

(2)   The metal foil-clad laminate according to claim 1, wherein the polyimide resin layer has a thickness of 1 to 10 µm.   The metal foil-clad laminate according to claim 1 or 2, wherein the titanium dioxide content is 10 to 100 parts by weight with respect to 100 parts by weight of the resin component of the thermosetting resin composition.   The metal foil-clad laminate according to any one of claims 1 to 3, wherein the thermosetting resin composition is a thermosetting resin composition containing a bisphenol A novolac type epoxy resin and an alicyclic epoxy resin.   The metal foil-clad laminate according to claim 4, wherein the thermosetting resin composition is a thermosetting resin composition containing a cyanate ester compound and / or an acid anhydride.   A metal foil-clad laminate according to any one of claims 1 to 5, a resin composite metal foil in which the polyimide resin layer is formed on one side of the metal foil, a prepreg comprising the thermosetting resin composition and a base material A method for producing a metal foil-clad laminate, which is obtained by combining and forming by lamination under heating and pressure.