WO2012111641A1

WO2012111641A1 - Led substrate

Info

Publication number: WO2012111641A1
Application number: PCT/JP2012/053325
Authority: WO
Inventors: 細田　朋也; 光男前田; 岡本　敏
Original assignee: 住友化学株式会社
Priority date: 2011-02-16
Filing date: 2012-02-14
Publication date: 2012-08-23
Also published as: JP2012186454A; TW201244187A

Abstract

The present invention addresses the problem of providing an LED substrate having an insulating layer that has excellent performance as a water-vapor barrier. The present invention relates to an LED substrate comprising a conductor layer provided on at least one surface of an insulating layer comprising a liquid-crystal polyester that has a repeating unit represented by formula (1), a repeating unit represented by formula (2), and a repeating unit represented by formula (3), with repeating units containing 2,6-naphthylene groups constituting at least 40 mol% of all of the repeating units in said liquid-crystal polyester. (1) -O-Ar¹-CO- (2) -CO-Ar²-CO- (3) -O-Ar³-O- (Ar¹ represents a 2,6-naphthylene group, a 1,4-phenylene group, or a 4,4'-biphenylene group. Ar² and Ar³ each independently represent a 2,6-naphthylene group, a 1,4-phenylene group, a 1,3-phenylene group, or a 4,4'-biphenylene group.)

Description

LED substrate

The present invention relates to an LED substrate having an insulating layer made of liquid crystal polyester. The present invention also relates to an LED package using the LED substrate.

The insulating layer of the LED (light-emitting diode) substrate is required to have high heat resistance so that it can withstand the high temperatures when the LED element is mounted by soldering or during LED emission, and the dimensions change even at high temperatures. As it is difficult, the coefficient of linear expansion is required to be low, and further, the heat conductivity is required to be high so that heat can be easily radiated. From such a point of view, the use of liquid crystalline polyester as the material for the insulating layer of the LED substrate has been studied. For example, Patent Document 1 discloses a predetermined aromatic hydroxy as the material for the insulating layer of the LED substrate. 30 to 45 mol% of repeating units derived from carboxylic acid, 27.5 mol% of repeating units derived from a predetermined aromatic dicarboxylic acid, and derived from a predetermined aromatic diol, aromatic hydroxyamine or aromatic diamine It is disclosed that a liquid crystal polyester having 27.5 mol% of repeating units is used. Specifically, 35 mol% of repeating units derived from 6-hydroxy-2-naphthoic acid and repeating units derived from isophthalic acid are disclosed. A liquid crystal polyester having 32.5 mol% and 32.5 mol% of repeating units derived from p-aminophenol It is shown.

JP 2010-114427 A

As disclosed in Patent Document 1, if liquid crystal polyester is used as the material of the insulating layer of the LED substrate, the insulating layer has high heat resistance, low linear expansion coefficient, and high thermal conductivity. From the viewpoint of improving reliability, in addition to these performances, water vapor barrier properties are required. Then, the objective of this invention is providing the board | substrate for LED which has the insulating layer comprised from liquid crystalline polyester and excellent in water vapor | steam barrier property.

In order to achieve the object, the present invention comprises a repeating unit represented by the following formula (1), a repeating unit represented by the following formula (2), and a repeating unit represented by the following formula (3). And the content of the repeating unit containing 2,6-naphthylene group is 40 mol% or more with respect to the total amount of all repeating units on at least one surface of the insulating layer composed of the liquid crystal polyester, An LED substrate provided with a conductor layer is provided.
—O—Ar ¹ —CO— (1)
—CO—Ar ² —CO— (2)
—O—Ar ³ —O— (3)

(Ar ¹ represents a 2,6-naphthylene group, a 1,4-phenylene group or a 4,4′-biphenylylene group. Ar ² and Ar ³ are each independently a 2,6-naphthylene group, 1,4 Represents a -phenylene group, a 1,3-phenylene group or a 4,4′-biphenylylene group, wherein the hydrogen atoms in the group represented by Ar ¹ , Ar ² or Ar ³ are each independently a halogen atom or an alkyl group; Alternatively, it may be substituted with an aryl group.)

Further, the present invention is composed of liquid crystal polyester, on at least one surface of an insulating layer having a water vapor permeability measured at a temperature of 40 ° C. and a relative humidity of 90% of 0.005 g / m ² · 24 h or less, An LED substrate provided with a conductor layer is provided.

Furthermore, the present invention relates to an insulation composed of a liquid crystal polyester having a water vapor permeability of 0.005 g / m ² · 24 h or less measured at a temperature of 40 ° C. and a relative humidity of 90% when a film having a thickness of 50 μm is formed. Provided is an LED substrate in which a conductor layer is provided on at least one surface of the layer.

In addition, the present invention provides an LED package in which an LED element is disposed on the conductor layer of any one of the LED substrates.

The LED substrate of the present invention has an insulating layer excellent in water vapor barrier properties, and by using this, a highly reliable LED package can be obtained.

It is sectional drawing which shows the example of the LED package of this invention typically.

The liquid crystalline polyester constituting the insulating layer of the LED substrate of the present invention is a polyester that exhibits optical anisotropy when melted, and is preferably a repeating unit represented by the following formula (1) (hereinafter referred to as repeating unit (1 ), A repeating unit represented by the following formula (2) (hereinafter sometimes referred to as repeating unit (2)), and a repeating unit represented by the following formula (3) (hereinafter referred to as repeating unit). (3)).

—O—Ar ¹ —CO— (1)
—CO—Ar ² —CO— (2)
—O—Ar ³ —O— (3)
(Ar ¹ represents a 2,6-naphthylene group, a 1,4-phenylene group or a 4,4′-biphenylylene group. Ar ² and Ar ³ are each independently a 2,6-naphthylene group, 1,4 -Represents a phenylene group, a 1,3-phenylene group or a 4,4′-biphenylylene group, wherein the hydrogen atom in the group represented by Ar ¹ , Ar ² or Ar ³ is independently a halogen atom or a carbon number (It may be substituted with an alkyl group of 1 to 10 or an aryl group of 6 to 20 carbon atoms.)

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

The repeating unit (1) is a repeating unit derived from a predetermined aromatic hydroxycarboxylic acid. As the repeating unit (1), those in which Ar ¹ is a 2,6-naphthylene group, that is, a repeating unit derived from 6-hydroxy-2-naphthoic acid is preferable.

The repeating unit (2) is a repeating unit derived from a predetermined aromatic dicarboxylic acid. As the repeating unit (2), Ar ² is a 2,6-naphthylene group, that is, a repeating unit derived from 2,6-naphthalenedicarboxylic acid, and Ar ² is a 1,4-phenylene group, Repeating units derived from terephthalic acid are preferred.

The repeating unit (3) is a repeating unit derived from a predetermined aromatic diol. As the repeating unit (3), Ar ³ is a 1,4-phenylene group, that is, a repeating unit derived from hydroquinone, and Ar ³ is a 4,4′-biphenylylene group, that is, 4,4′-. Repeating units derived from dihydroxybiphenyl are preferred.

Content of repeating unit containing 2,6-naphthylene group in liquid crystal polyester, that is, repeating unit (1) in which Ar ¹ is 2,6-naphthylene group, repeating unit in which Ar ² is 2,6-naphthylene group (2) and the total content of the repeating unit (3) in which Ar ³ is a 2,6-naphthylene group is the total amount of all repeating units (the mass of each repeating unit constituting the liquid crystal polyester is expressed by the formula of each repeating unit) By dividing by the amount, the substance amount equivalent amount (mole) of each repeating unit is obtained, and the sum thereof is 40 mol% or more. By forming a liquid crystal polyester having such a predetermined repeating unit composition into a film, a liquid crystal polyester film having excellent water vapor barrier properties can be obtained. The content of 2,6-naphthylene groups is preferably 50 mol% or more, more preferably 60 mol% or more, and further preferably 70 mol% or more.

In the liquid crystal polyester, the content of the repeating unit (1) is preferably 30 to 80 mol%, more preferably 40 to 70 mol%, still more preferably 45 to 65 mol, based on the total amount of all repeating units. The content of the repeating unit (2) is preferably 10 to 35 mol%, more preferably 15 to 30 mol%, still more preferably 17.5 to 27.27%, based on the total amount of all repeating units. The content of the repeating unit (3) is preferably from 10 to 35 mol%, more preferably from 15 to 30 mol%, still more preferably from 17.5 to mol based on the total amount of all repeating units. 27.5 mol%. The liquid crystal polyester having such a predetermined repeating unit composition has an excellent balance between heat resistance and moldability. In addition, it is preferable that content of a repeating unit (2) and content of a repeating unit (3) are substantially equal. The liquid crystalline polyester may have a repeating unit other than the repeating units (1) to (3) as necessary, but the content thereof is usually 10 moles relative to the total amount of all the repeating units. % Or less, preferably 5 mol% or less.

A typical example of a liquid crystalline polyester having high heat resistance and high melt tension is a repeating unit (1) in which Ar ¹ is a 2,6-naphthylene group, that is, 6-hydroxy-2- with respect to the total amount of all repeating units. The repeating unit derived from naphthoic acid is preferably 40 to 74.8 mol%, more preferably 40 to 64.5 mol%, still more preferably 50 to 58 mol%, and Ar ² is a 2,6-naphthylene group. The repeating unit (2), that is, the repeating unit derived from 2,6-naphthalenedicarboxylic acid is preferably 12.5 to 30 mol%, more preferably 17.5 to 30 mol%, and still more preferably 20 to 25 mol%. a mole%, repeating units Ar ² is 1,4-phenylene group (2), i.e., repeating units derived from terephthalic acid, preferably 0.2 to 15 mol%, more preferably 0. To 12 mol%, more preferably having 2 to 10 mol%, the repeating units Ar ³ is 1,4-phenylene group (3), i.e., a repeating unit derived from hydroquinone, preferably 12.5 to 30 mol %, more preferably 17.5 to 30 mol%, more preferably having 20-25 mol%, and the content of the repeating unit (2) Ar ² is 2,6-naphthylene group, Ar ² is The total content of the repeating unit (2) which is a 2,6-naphthylene group and the repeating unit (2) wherein Ar ² is a 1,4-phenylene group is preferably 0.5 mol times or more, more preferably It is 0.6 mol times or more.

The liquid crystalline polyester is a monomer that gives a repeating unit (1), that is, a predetermined aromatic hydroxycarboxylic acid, a monomer that gives a repeating unit (2), that is, a monomer that gives a predetermined aromatic dicarboxylic acid, and a repeating unit (3), That is, a predetermined aromatic diol is added to a total amount of monomers having 2,6-naphthylene groups, that is, a total amount of 6-hydroxy-2-naphthoic acid, 2,6-naphthalenedicarboxylic acid and 2,6-naphthalenediol. The polymer can be produced by polymerization (polycondensation) so as to be 40 mol% or more based on the total amount of all monomers. In that case, the aromatic hydroxycarboxylic acid, the aromatic dicarboxylic acid, and the aromatic diol may be independently replaced by a part or all of the polymerizable derivatives thereof. Examples of polymerizable derivatives of a compound having a carboxyl group such as an aromatic hydroxycarboxylic acid and an aromatic dicarboxylic acid include those obtained by converting a carboxyl group into an alkoxycarbonyl group or an aryloxycarbonyl group, and a carboxyl group as a haloformyl. And a group formed by converting a carboxyl group into an acyloxycarbonyl group. Examples of polymerizable derivatives of hydroxyl group-containing compounds such as aromatic hydroxycarboxylic acids and aromatic diols include those obtained by acylating a hydroxyl group and converting it to an acyloxyl group.

The liquid crystalline polyester is preferably produced by melt polymerizing monomers and solid-phase polymerizing the obtained polymer (prepolymer). Thereby, liquid crystalline polyester with high heat resistance and high melt tension can be manufactured with good operability. Melt polymerization may be carried out in the presence of a catalyst. Examples of this catalyst include metal compounds such as magnesium acetate, stannous acetate, tetrabutyl titanate, lead acetate, sodium acetate, potassium acetate, and antimony trioxide, Nitrogen-containing heterocyclic compounds such as N, N-dimethylaminopyridine and N-methylimidazole, and nitrogen-containing heterocyclic compounds are preferably used. The liquid crystal polyester having the predetermined repeating unit composition thus obtained is excellent in water vapor barrier properties.

The liquid crystal polyester has a flow start temperature of preferably 280 ° C. or higher, more preferably 290 ° C. or higher, further preferably 295 ° C. or higher, and is usually 380 ° C. or lower, preferably 350 ° C. or lower. As the flow start temperature is higher, the heat resistance and melt tension are more likely to be improved. However, if the flow start temperature is too high, a high temperature is required for melting, and thermal deterioration tends to occur during molding.

The flow start temperature is also called flow temperature or flow temperature, and is 4 ° C./min under a load of 9.8 MPa (100 kg / cm ² ) using a capillary rheometer having a nozzle with an inner diameter of 1 mm and a length of 10 mm. This is a temperature at which the melt viscosity shows 4800 Pa · s (48,000 poise) when the heated melt of the liquid crystal polyester is extruded from the nozzle at a temperature rising rate of 5 ° C., which is a measure of the molecular weight of the liquid crystal polyester ( (See Naoyuki, “Liquid Crystal Polymers—Synthesis / Molding / Applications”, CMC Corporation, June 5, 1987, p. 95).

The liquid crystal polyester having the predetermined repeating unit composition thus obtained is excellent in water vapor barrier properties and used as a material for the tab carrier tape of the present invention. The liquid crystal polyester in the present invention preferably has a water vapor transmission rate measured at a temperature of 40 ° C. and a relative humidity of 90% when formed into a film having a thickness of 50 μm, preferably 0.05 g / m ² · 24 h or less, More preferably, it is 0.01 g / m < ² > * 24h or less, More preferably, it is 0.005 g / m < ² > * 24h or less.

The liquid crystal polyester may be blended with other components as necessary to form a composition. Examples of other components include fillers, thermoplastic resins other than liquid crystal polyesters, and additives. The ratio of the liquid crystal polyester in the entire composition is preferably 80% by mass or more, and more preferably 90% by mass or more.

Examples of fillers include glass fibers such as milled glass fibers and chopped glass fibers, potassium titanate whiskers, alumina whiskers, aluminum borate whiskers, silicon carbide whiskers, silicon nitride whiskers, and other metal or non-metallic whiskers. , Glass beads, hollow glass spheres, glass powder, mica, talc, clay, silica, alumina, potassium titanate, wollastonite, calcium carbonate (heavy, light, colloidal, etc.), magnesium carbonate, basic magnesium carbonate, sodium sulfate , Calcium sulfate, barium sulfate, calcium sulfite, aluminum hydroxide, magnesium hydroxide, calcium hydroxide, calcium silicate, silica sand, silica, quartz, titanium oxide, zinc oxide, iron oxide graphite, molybdenum, asbestos, silica alumina Wei, alumina fibers, gypsum fibers, carbon fibers, carbon black, white carbon, diatomaceous earth, bentonite, sericite, Shirasu and graphite are mentioned, it is also possible to use two or more of them, if necessary. Among these, glass fiber, mica, talc and carbon fiber are preferably used.

The filler may be surface-treated as necessary, and examples of the surface treatment agent include reactivity such as a silane coupling agent, a titanate coupling agent, and a borane coupling agent. Examples include coupling agents and lubricants such as higher fatty acids, higher fatty acid esters, higher fatty acid metal salts, and fluorocarbon surfactants.

Examples of thermoplastic resins other than liquid crystal polyester include polycarbonate, polyamide, polysulfone, polyphenylene sulfide, polyphenylene ether, polyether ketone, and polyetherimide resin.

Examples of additives include mold release improvers such as fluororesins and metal soaps, nucleating agents, antioxidants, stabilizers, plasticizers, lubricants, anti-coloring agents, coloring agents, ultraviolet absorbers, antistatic agents, Examples include lubricants and flame retardants.

A liquid crystal polyester film constituting the insulating layer of the LED substrate of the present invention can be obtained by forming a film of the liquid crystal polyester thus obtained or a composition thereof. Examples of the film forming method include an extrusion molding method, a press molding method, a solution casting method, and an injection molding method, and the extrusion molding method is preferable. Examples of the extrusion molding method include a T-die method and an inflation method. In the T-die method, uniaxial stretching or biaxial stretching may be performed.

The draw ratio (draft ratio) of the uniaxially stretched film is usually 1.1 to 40, preferably 10 to 40, more preferably 15 to 35. The stretch ratio in the MD direction (extrusion direction) of the biaxial film is usually 1.2 to 40 times, and the stretch ratio in the TD direction (direction perpendicular to the extrusion direction) of the biaxial film is usually 1.2 to 20 times. Is double. The stretch ratio in the MD direction of the inflation film (drawdown ratio = bubble take-off speed / resin discharge speed) is usually 1.5 to 50, preferably 5 to 30, and the stretch ratio of TD of the inflation film (blow ratio = bubble) Diameter / annular slit diameter) is usually 1.5 to 10, preferably 2 to 5.

The thickness of the liquid crystal polyester film is preferably 5 to 100 μm, more preferably 10 to 75 μm, and further preferably 15 to 75 μm. If it is too thin, the strength will be insufficient, and if it is too thick, the flexibility will be insufficient.

The liquid crystal polyester film thus obtained has an excellent water vapor barrier property and is used as an insulating layer of the LED substrate of the present invention. The liquid crystal polyester film, water vapor transmission rate being measured at a temperature 40 ° C. and a relative humidity of 90%, preferably from 0.05g / m ² · 24h or less, more preferably 0.01g / m ² · 24h or less, further Preferably, it is 0.005 g / m ² · 24 h or less.

A laminated film obtained by laminating a plurality of liquid crystal polyester films or laminating another film such as a thermoplastic resin film on the liquid crystal polyester film is also used as the insulating layer of the LED substrate of the present invention. Moreover, in order to further improve the water vapor barrier property on the liquid crystal polyester film or the laminated film, a laminated film obtained by providing a water vapor barrier layer or other functional layer is also an insulating layer of the LED substrate of the present invention. Used as

The water vapor barrier layer is provided on at least one surface of the liquid crystal polyester film. When providing on the single side | surface of a liquid crystal polyester film, providing on the back surface (surface opposite to the surface where an LED element is arrange | positioned) of a liquid crystal polyester film is preferable.

Substances constituting the water vapor barrier layer include at least one element selected from the group consisting of aluminum, silicon, titanium, chromium, iron, cobalt, nickel, copper, zinc, silver and gold, an oxide, and a nitride And oxynitrides are preferable, and two or more of them may be used as necessary.

As a method for forming the water vapor barrier layer, for example, a vapor deposition method, a sputtering method, a PVD method such as an ion plating method, a CVD method such as a plasma CVD method, a thermal CVD method, a laser CVD method, a sol-gel method, a plating method, etc. And wet methods such as a coating method. Further, a foil prepared or obtained separately may be bonded to the liquid crystal polyester film.

The liquid crystal polyester film may be subjected to a surface treatment as necessary. Examples of the surface treatment method include corona discharge treatment, flame treatment, sputtering treatment, solvent treatment, UV treatment, and plasma treatment.

Using the liquid crystalline polyester thus obtained as an insulating layer, an LED substrate is obtained by providing, on at least one surface thereof, a conductor layer that becomes a wiring electrically connected to the LED element after mounting the LED element. Preferably, as shown in FIG. 1, a conductor layer 5 is provided on one surface of the insulating layer 4, and heat generated from the LED element 7 during the operation of the LED package 1 is efficiently externally provided on the other surface. An LED substrate 2 is obtained by providing the heat dissipation layer 3 that dissipates heat.

The conductor layer 5 is excellent in conductivity, so that the electrode formed on the laminated film may be a transparent electrode, but it need not be transparent. In general, a conductive paste containing a conductive material such as a metal such as Al or Cu or carbon or a metal such as Al or Cu may be used. The formation method of the conductor layer is not particularly limited, and a known formation method such as vapor deposition, sputtering, ion plating method, plating, coating, or printing may be used. As the heat dissipation layer 3, since it is excellent in heat dissipation, a material containing copper or aluminum, that is, a metal material is preferable, and a material made of copper or a copper alloy is preferable.

As a method of laminating the conductor layer 5 and the heat dissipation layer 3 with the insulating layer (liquid crystal polyester film) 4, for example, a method of laminating a metal foil such as a copper foil on the liquid crystal polyester film 4, The method of coating on the polyester film 4 is mentioned.

Examples of the method of laminating the metal foil include a method of bonding the metal foil and the liquid crystal polyester film 4 using an adhesive, and a method of heat-sealing by hot pressing. When an adhesive is used, for example, an epoxy resin adhesive or an acrylic resin adhesive can be used. The processing conditions for hot pressing can be optimized as appropriate depending on the scale and shape of the liquid crystal polyester film 4 to be used, the thickness and type of the metal foil to be used, etc., but it is particularly preferable to hot press under vacuum. In addition, it is preferable to optimize process temperature and a process pressure suitably so that the board | substrate 2 for LED obtained may express favorable surface smoothness as conditions of a hot press. This treatment temperature is preferably determined based on the temperature condition of the solid layer polymerization performed when producing the liquid crystal polyester to be hot pressed. Specifically, the maximum temperature of the solid layer polymerization is T _max [° C.]. At this time, it is preferable to perform hot pressing at a temperature exceeding T _max, and it is more preferable to perform hot pressing at a temperature of T _max +5 [° C.] or higher. The upper limit of the temperature of the hot press is selected so as to be lower than the decomposition temperature of the liquid crystal polyester contained in the liquid crystal polyester film 4 to be used, but it is preferable that the upper limit of the temperature is 30 ° C. or lower. The decomposition temperature referred to here is determined by a known means such as thermogravimetry analysis. The time for hot pressing is usually 1 to 30 hours, and the pressure is usually 1 to 30 MPa.

Examples of the coating method of metal fine particles such as copper fine particles include a plating method, a screen printing method, and a sputtering method. Of these, the plating method is preferable, and specifically, electroless plating or electrolytic plating is preferably used. In order to further improve the properties of the conductor layer 5 formed by plating, the conductor layer 5 is preferably heat-treated, and the conditions for the heat treatment are also equivalent to the conditions described as the conditions for the hot press. Is adopted.

Among these, in order to form a suitable material, that is, the conductor layer 5 and the heat dissipation layer 3 containing copper, the operation is to laminate the conductor layer 5 and the heat dissipation layer 3 on the liquid crystal polyester film 4 using a copper foil. From the viewpoint of sex. In addition, the use of copper foil is advantageous in terms of economy.

Etching (processing) is usually used to form wiring by patterning the conductor layer 5. First, masking is performed so that the wiring pattern becomes a predetermined pattern. In the masked conductor layer 5 portion and the unmasked conductor layer 5 portion, the latter conductor layer 5 portion is wet-processed (chemical treatment). ) Is removed by etching. As a chemical | medical agent used for this etching process, ferric chloride aqueous solution is mentioned, for example. For masking, a commercially available etching resist or dry film may be used.

Next, the etching resist and dry film are removed from the masked conductor layer 5 with acetone or a sodium hydroxide aqueous solution. In this way, a predetermined wiring can be formed.

The LED element 7 is mounted on the conductor layer 5 by first applying solder on the conductor layer 5, placing the LED element 7 thereon, and then passing the reflow furnace or the like to melt the solder. The LED element 7 is preferably surface-mounted, but the LED element 7 and the conductor layer 5 may be electrically connected by wire bonding. Furthermore, it is preferable to seal the LED element 7 with the sealing layer 6 using transfer molding or the like. Here, transfer molding refers to a technique of press-fitting a resin into a clamped mold.

The LED package 1 thus obtained may be provided with a via hole that connects the conductor layer 5 and the heat dissipation layer 3. Thereby, the heat generated in the LED element 7 and the conductor layer 5 can be efficiently flowed to the heat radiating layer 3 side, so that efficient heat radiation can be performed. The LED package 1 may be a chip type or a film type.

[Measurement of flow start temperature]
Using a flow tester (“CFT-500 type” manufactured by Shimadzu Corp.), about 2 g of the sample was filled into a capillary rheometer equipped with a die having an inner diameter of 1 mm and a length of 10 mm, and 9.8 MPa (100 kgf / The sample was extruded while melting at a temperature rising rate of 4 ° C./min under a load of cm ² ), and a temperature at which the melt viscosity was 4800 Pa · s (48000 poise) was measured.

[Evaluation of water vapor barrier properties]
In accordance with JIS K7129 C method, the water vapor transmission rate was measured at a temperature of 40 ° C. and a relative humidity of 90% with a gas permeability / moisture permeability measuring device (“GTR-30X” from GTR Tech Co., Ltd.). .

[Measurement of surface resistivity of ITO film]
The surface resistivity (sheet resistance) of the ITO film was measured with a four-probe resistance measuring device (Loresta AP manufactured by Mitsubishi Chemical).

Production Example 1
In a reactor equipped with a stirrer, a torque meter, a nitrogen gas inlet tube, a thermometer and a reflux condenser, 103.499 g (5.5 mol) of 6-hydroxy-2-naphthoic acid and 2,6-naphthalenedicarboxylic acid 378 were added. 0.33 g (1.75 mol), 83.07 g (0.5 mol) of terephthalic acid, 272.52 g of hydroquinone (2.475 mol: 0.225 based on the total amount of 2,6-naphthalenedicarboxylic acid and terephthalic acid) Molar excess), 1226.87 g (12 moles) of acetic anhydride, and 0.17 g of 1-methylimidazole as a catalyst, and after replacing the gas in the reactor with nitrogen gas, stirring at room temperature under a nitrogen gas stream To 145 ° C. over 15 minutes and refluxed at 145 ° C. for 1 hour. Next, while distilling off by-product acetic acid and unreacted acetic anhydride, the temperature was raised from 145 ° C. to 310 ° C. over 3 hours and 30 minutes, held at 310 ° C. for 3 hours, then the contents were taken out and cooled to room temperature did. The obtained solid is pulverized to a particle size of about 0.1 to 1 mm with a pulverizer, then heated from room temperature to 250 ° C. over 1 hour in a nitrogen atmosphere, and then increased from 250 ° C. to 310 ° C. over 10 hours. Solid state polymerization was performed by warming and holding at 310 ° C. for 5 hours. After solid state polymerization, the mixture was cooled to obtain a powdery liquid crystal polyester. In this liquid crystalline polyester, 55 mol% of the repeating unit (1) in which Ar ¹ is a 2,6-naphthylene group and Ar ² is a 2,6-naphthylene group in terms of the total amount of all repeating units ( 2) 17.5 mol%, Ar ² is 1,4-phenylene group repeating unit (2) 5 mol%, and Ar ³ is 1,4-phenylene group repeating unit (3) 22. 5%, and the flow start temperature was 333 ° C.

Production Example 2
In the same reactor as in Production Example 1, 911 g (6.6 mol) of p-hydroxybenzoic acid, 274 g (1.65 mol) of terephthalic acid, 91 g (0.55 mol) of isophthalic acid, 4,4′-dihydroxybiphenyl 409 g (2.2 mol), 1235 g of acetic anhydride (12.1 mol), and 0.17 g of 1-methylimidazole as a catalyst were added, and the gas in the reactor was replaced with nitrogen gas, followed by stirring under a nitrogen gas stream While raising the temperature from room temperature to 150 ° C. over 15 minutes, the mixture was refluxed at 150 ° C. for 1 hour. Next, after adding 1.7 g of 1-methylimidazole, the temperature was raised from 150 ° C. to 320 ° C. over 2 hours and 50 minutes while distilling off by-product acetic acid and unreacted acetic anhydride, and an increase in torque was observed. At that time, the contents were removed and cooled to room temperature. The obtained solid is pulverized to a particle size of about 0.1 to 1 mm with a pulverizer, then heated from room temperature to 250 ° C. over 1 hour in a nitrogen atmosphere, and then increased from 250 ° C. to 285 ° C. over 5 hours. Solid state polymerization was performed by warming and holding at 285 ° C. for 3 hours. After solid state polymerization, the mixture was cooled to obtain a powdery liquid crystal polyester. In this liquid crystal polyester, 60 mol% of the repeating unit (1) in which Ar ¹ is a 1,4-phenylene group, 15 mol% of the repeating unit (2) in which Ar ² is a 1,4-phenylene group, and Ar ² is 5% by mole of the repeating unit (2) which is a 1,3-phenylene group and 20% of the repeating unit (3) whose Ar ³ is a 4,4′-biphenylylene group, and its flow initiation temperature is 327 ° C. there were.

Example 1
The liquid crystalline polyester obtained in Production Example 1 was granulated with a twin-screw extruder ("PCM-30" by Ikekai Co., Ltd.), pelletized, and then supplied to a single-screw extruder (screw diameter 50 mm). It was melted, extruded from a T die (lip length: 300 mm, lip clearance: 1 mm, die temperature: 350 ° C.) and cooled to obtain a liquid crystal polyester film having a thickness of 25 μm. This liquid crystal polyester film has a water vapor permeability of 0.011 g / m ² · 24 h, and is excellent in water vapor barrier properties as a liquid crystal polyester film serving as an insulating layer of an LED substrate.

Example 2
The liquid crystalline polyester obtained in Production Example 1 was granulated with a twin-screw extruder ("PCM-30" by Ikekai Co., Ltd.), pelletized, and then supplied to a single-screw extruder (screw diameter 50 mm). It was melted, extruded from a T-die (lip length 300 mm, lip clearance 1 mm, die temperature 350 ° C.) into a film and cooled to obtain a liquid crystal polyester having a thickness of 50 μm. The liquid crystal polyester film has a water vapor permeability of 0.0030 g / m ² · 24 h, and is excellent in water vapor barrier properties as a liquid crystal polyester film serving as an insulating layer of the LED substrate.

Example 3
A 200 nm thick transparent electrode (ITO film) was formed at a substrate temperature of 180 ° C. using ITO (Indium Tin Oxide) on the opposite surface of the laminated film obtained in Example 2 on which the gas barrier layer was formed by ion plating. The sheet resistance of the transparent electrode formed on this laminated film was measured and found to be 9.1Ω / □.

Comparative Example 1
The liquid crystalline polyester obtained in Production Example 2 was granulated with a twin-screw extruder ("PCM-30" from Ikekai Co., Ltd.), pelletized, and then supplied to a single-screw extruder (screw diameter 50 mm). It was melted and extruded from a T die (lip length 300 mm, lip clearance 1 mm, die temperature 350 ° C.) into a film and cooled to obtain a liquid crystal polyester film having a thickness of 50 μm. The water vapor permeability of this liquid crystal polyester film is 0.343 g / m ² · 24 h, and the water vapor barrier property is insufficient as a liquid crystal polyester film serving as an insulating layer of the LED substrate.

Comparative Example 2
The powdered liquid crystalline polyester obtained in Production Example 2 was granulated with a twin screw extruder ("PCM-30" manufactured by Ikegai Co., Ltd.) and pelletized, and then a single screw extruder (screw diameter 50 mm). And melted, extruded from a T-die (lip length 300 mm, lip clearance 1 mm, die temperature 350 ° C.) and cooled to obtain a liquid crystal polyester film having a thickness of 50 μm. The water vapor permeability of this liquid crystal polyester film is 0.080 g / m ² · 24 h, and the water vapor barrier property is insufficient as a liquid crystal polyester film serving as an insulating layer of the LED substrate.

Comparative Example 3
About the laminated film obtained in Comparative Example 2, a transparent electrode having a thickness of 200 nm was formed on the opposite surface of the gas barrier layer formed by ion plating method using ITO (Indium Tin Oxide) at a substrate temperature of 180 ° C. When the sheet resistance of the transparent electrode formed on this laminated film was measured, it was 12.3Ω / □.

DESCRIPTION OF SYMBOLS 1 ... LED package, 2 ... LED board, 3 ... Heat dissipation layer, 4 ... Insulating layer (liquid crystal polyester layer), 5 ... Conductive layer, 6 ... Sealing layer, 7 ... LED elements.

Claims

It has a repeating unit represented by the following formula (1), a repeating unit represented by the following formula (2), and a repeating unit represented by the following formula (3), and includes a 2,6-naphthylene group. An LED substrate in which a conductor layer is provided on at least one surface of an insulating layer composed of a liquid crystal polyester having a repeating unit content of 40 mol% or more based on the total amount of all repeating units.
—O—Ar 1 —CO— (1)
—CO—Ar 2 —CO— (2)
—O—Ar 3 —O— (3)
(Ar 1 represents a 2,6-naphthylene group, a 1,4-phenylene group or a 4,4′-biphenylylene group. Ar 2 and Ar 3 are each independently a 2,6-naphthylene group, 1,4 Represents a -phenylene group, a 1,3-phenylene group or a 4,4′-biphenylylene group, wherein the hydrogen atoms in the group represented by Ar 1 , Ar 2 or Ar 3 are each independently a halogen atom or an alkyl group; Alternatively, it may be substituted with an aryl group.)
2. The LED substrate according to claim 1, wherein the liquid crystal polyester has a water vapor permeability measured at a temperature of 40 ° C. and a relative humidity of 90% of 0.005 g / m 2 · 24 h or less.
A conductor layer is provided on at least one surface of an insulating layer composed of a liquid crystal polyester having a water vapor permeability of 0.005 g / m 2 · 24 h or less measured at a temperature of 40 ° C. and a relative humidity of 90%. LED substrate.
At least one surface of an insulating layer composed of a liquid crystal polyester having a water vapor permeability of 0.005 g / m 2 · 24 h or less measured at a temperature of 40 ° C. and a relative humidity of 90% when the film is 50 μm thick. An LED substrate on which a conductor layer is provided.
The LED substrate according to any one of claims 1 to 4, wherein a water vapor barrier layer is provided on at least one surface of the insulating layer.
An LED package in which an LED element is disposed on the conductor layer of the LED substrate according to any one of claims 1 to 4.