WO2015068652A1 - Laminated article and method for manufacturing light-emitting device using same - Google Patents

Abstract

　[Problem] The purpose of the present invention is to provide a laminated article obtained by forming a phosphor sheet at a uniform thickness along the upper surface and side surfaces of an LED chip. Another purpose is to provide a method for manufacturing a light-emitting device by covering the upper surface and side surfaces of the LED chip with the phosphor sheet by a highly productive method using this laminated article. [Solution] The laminated article includes a support substrate and a phosphor sheet containing a phosphor and a resin, wherein the support substrate has a rupture elongation, determined by a tensile test, of 200% or greater at 23°C, the Young's modulus of the support substrate at 23°C being 600MPa or less.

Description

Laminated body and method of manufacturing light emitting device using the same

The present invention relates to a laminate including a phosphor and a phosphor sheet containing a resin. More specifically, the present invention relates to a laminate including a phosphor sheet for converting the emission wavelength from the upper surface and side surfaces of an LED chip.

Light-emitting diodes (LEDs, Light Emitting Diodes) are used for backlights of liquid crystal displays (LCDs), car headlights, etc. with low power consumption, long life, and design, etc. The market is rapidly expanding not only in the automotive field but also for general lighting.

LEDs are classified into a lateral type, a vertical type, and a flip chip type depending on the mounting type, but the flip chip type LED is attracting attention because of its high luminance and excellent heat dissipation. However, in conventional flip-chip type LED sealing, it is impossible to equalize the thickness of the phosphor layer between the top surface and the side surface of the chip, resulting in the problem of uneven azimuth of the emitted color. It was.

In response to this problem, a technique has been proposed in which a phosphor sheet, which is a sheet containing a phosphor, is uniformly attached around the chip with good followability (see, for example, Patent Documents 1 and 2). Patent Document 1 is a method in which a phosphor sheet is attached to the side surface of an LED chip using a pressure member in which a recess that is slightly larger than the LED chip is formed. Further, Patent Document 2 carries out a first-stage pasting process in which a laminated body including a supporting base material and a phosphor sheet is placed on an LED chip, and this is pressurized with a diaphragm film in a vacuum state, and thereafter the supporting base material is removed. In addition, the phosphor sheet is attached to the side surface of the LED chip through a second-stage attaching step by non-contact pressure.

JP 2011-138831 A International Publication No. 2012/023119

However, the method of Patent Document 1 is not economical because it is necessary to remake a mold as a pressure member every time the type of LED changes. In addition, since the pressure member is brought into contact with the phosphor sheet and pressed, there is a problem that the sheet is damaged or the pressure member is contaminated, resulting in poor productivity.

Moreover, since the phosphor sheet cannot follow the chip side surface due to insufficient flexibility of the support base material only in the first stage diaphragm pressurization process, the method of Patent Document 2 is once after returning to atmospheric pressure and removing the support base material. The non-contact pressurizing process in the second stage is performed, and there is a problem in terms of productivity.

An object of the present invention is to provide a laminate in which a phosphor sheet is formed with a uniform film thickness with good followability on the upper and side surfaces of an LED chip. Moreover, the manufacturing method of the light-emitting device which coat | covers the upper surface and side surface of a LED chip with a phosphor sheet | seat by a method with high productivity using this laminated body is provided.

The present invention is as follows.
[1] A laminate including a supporting substrate and a phosphor sheet containing a phosphor and a resin, and the elongation at break at 23 ° C. of the supporting substrate determined by a tensile test is 200% or more, and The laminated body whose Young's modulus in 23 degreeC of the said support base material is 600 Mpa or less.
[2] The laminate according to [1], wherein the Young's modulus at 23 ° C. of the support substrate is 400 MPa or less.
[3] The laminate according to [1], wherein the Young's modulus at 23 ° C. of the support base material is 100 MPa or less.
[4] The laminate according to any one of [1] to [3], wherein the support base material is polyvinyl chloride or polyurethane.
[5] A method for manufacturing a light-emitting device including a step (covering step) of covering the light-emitting surface of an LED chip bonded on a substrate with the phosphor sheet of the laminate according to any one of [1] to [4].
[6] A method for manufacturing a light-emitting device including a step (covering step) of covering the upper surface and side surfaces of an LED chip bonded on a substrate with the phosphor sheet of the laminate according to any one of [1] to [4].
[7] A method for manufacturing a light emitting device according to [5] or [6],
The distance a [μm] from the upper surface of the LED chip to the outer surface of the phosphor sheet at the portion where the LED chip and the phosphor sheet are in contact with each other on the upper surface of the LED chip, and the LED chip and the phosphor sheet on the side surface of the LED chip The distance b [μm] from the side surface of the LED chip to the outer surface of the phosphor sheet in the contacting portion is
1.00 <a / b <1.20
A method for manufacturing a light-emitting device that satisfies the above relationship.
[8] A method for manufacturing a light-emitting device according to [5] or [6], wherein the laminate is coated with the phosphor sheet according to any one of [1] to [4] (the coating step). The distance a [μm] from the upper surface of the LED chip to the outer surface of the phosphor sheet at the portion where the LED chip and the phosphor sheet are in contact with each other on the upper surface of the LED chip, and the LED chip and the phosphor sheet are The distance b [μm] from the LED chip side surface to the outer surface of the phosphor sheet in the portion in contact with the side surface is
1.00 <a / b <1.20
A method for manufacturing a light-emitting device that satisfies the above relationship.

According to the present invention, the phosphor sheet can be attached to the LED chip upper light emitting surface and the side light emitting surface with good followability. This also provides a light-emitting device that is free from uneven azimuth of emitted color.

Schematic diagram of the laminate of the present invention Schematic diagram of a laminate having a pressure-sensitive adhesive according to the present invention An example of a method for manufacturing a light emitting device using the laminate of the present invention Schematic cross section and top view of light emitting device covered with phosphor sheet

FIG. 1 shows the laminate of the present invention. The laminate 1 of the present invention includes a support substrate 2 and a phosphor sheet 3 containing a phosphor and a resin, and at 23 ° C., the elongation at break in the tensile test of the support substrate is 200% or more, And Young's modulus is 600 Mpa or less.

That is, the laminate of the present invention is a laminate comprising a support substrate and a phosphor sheet containing a phosphor and a resin, and the elongation at break at 23 ° C. of the support substrate determined by a tensile test is as follows. The laminate is 200% or more and has a Young's modulus at 23 ° C. of 600 MPa or less.

<Phosphor sheet>
As long as the phosphor sheet mainly contains a resin and a phosphor, various sheets can be used without any particular limitation. Other components may be included as necessary.

(Physical properties of phosphor sheet)
The phosphor sheet preferably has high elasticity around room temperature from the viewpoint of storage, transportability and processability. On the other hand, from the viewpoint of deforming and adhering so as to follow the LED chip, it is preferable that the elasticity becomes low under certain conditions and the flexibility and adhesiveness (adhesiveness) are expressed. From these viewpoints, it is preferable that the phosphor sheet is softened by heating at 60 ° C. or higher and exhibits adhesiveness.

The storage elastic modulus of such a phosphor sheet is preferably 0.1 MPa or more at 25 ° C., less than 0.1 MPa at 100 ° C., 0.5 MPa or more at 25 ° C., and less than 0.05 MPa at 100 ° C. It is more preferable.

The storage elastic modulus mentioned here is a storage elastic modulus when dynamic viscoelasticity measurement is performed. Dynamic viscoelasticity is the shear stress that appears when a steady state is reached when shear strain is applied to a material at a sinusoidal frequency. Is a method for analyzing dynamic mechanical characteristics of a material by decomposing it into components (viscous components) delayed by 90 °. Here, what is obtained by dividing the stress component whose phase matches the shear strain by the shear strain is the storage elastic modulus G ′, which represents the deformation and tracking of the material against the dynamic strain at each temperature. It is closely related to processability and adhesion.

In the case of the phosphor sheet according to the present invention, the sheet has a storage elastic modulus of 0.1 MPa or more at 25 ° C., so that the sheet can be surrounded by high shear stress such as cutting with a blade at room temperature (25 ° C.). Since it is cut without deformation, workability with high dimensional accuracy can be obtained. The upper limit of the storage elastic modulus at room temperature is not particularly limited for the purpose of the present invention, but is preferably 1 GPa or less in view of the necessity of reducing the stress strain after being bonded to the LED element. In addition, since the storage elastic modulus at 100 ° C. is less than 0.1 MPa, when heat pasting at 60 ° C. to 150 ° C. is performed, it quickly deforms and follows the shape of the LED chip surface, and has high adhesive strength. It is obtained. If the phosphor sheet is capable of obtaining a storage modulus of less than 0.1 MPa at 100 ° C., the storage modulus decreases as the temperature is increased from room temperature. However, in order to obtain practical adhesiveness, 60 ° C. or higher is preferable. In addition, when such a phosphor sheet is heated at a temperature exceeding 100 ° C., the storage elastic modulus further decreases and the sticking property is improved. However, at a temperature exceeding 150 ° C., the resin is not sufficiently relaxed. Curing of the resin proceeds rapidly, and cracks and peeling easily occur. Therefore, a suitable heat bonding temperature is 60 ° C. to 150 ° C., more preferably 60 ° C. to 120 ° C. The lower limit of the storage elastic modulus at 100 ° C. is not particularly limited for the purpose of the present invention, but if the fluidity is too high at the time of heating and pasting on the LED element, the shape processed by cutting or punching before pasting Therefore, it is desirable that the pressure be 0.001 MPa or more.

As long as the above storage elastic modulus can be obtained as a phosphor sheet, the resin contained therein may be in an uncured or semi-cured state. Then, it is preferable that resin contained is a thing after hardening. If the resin is in an uncured or semi-cured state, the curing reaction proceeds at room temperature during storage of the phosphor sheet, and the storage elastic modulus may be out of the proper range. In order to prevent this, it is desirable that the resin is completely cured, or has been cured to such an extent that the storage elastic modulus does not change for a long period of about one month when stored at room temperature.

(resin)
The resin contained in the phosphor sheet of the present invention can be any resin as long as the phosphor can be uniformly dispersed therein and can form a sheet.

Specifically, silicone resin, epoxy resin, polyarylate resin, PET modified polyarylate resin, polycarbonate resin, cyclic olefin, polyethylene terephthalate resin, polymethyl methacrylate resin, polypropylene resin, modified acrylic, polystyrene resin, and acrylonitrile / styrene Examples include copolymer resins. Here, PET is polyethylene terephthalate. In the present invention, a silicone resin or an epoxy resin is preferably used from the viewpoint of transparency. Furthermore, a silicone resin is particularly preferably used from the viewpoint of heat resistance.

As the silicone resin used in the present invention, curable silicone rubber is preferable. Either one liquid type or two liquid type (three liquid type) liquid structure may be used. Examples of the curable silicone rubber include a dealcohol-free type, a deoxime type, a deacetic acid type, and a dehydroxylamine type that cause a condensation reaction with moisture in the air or a catalyst. Moreover, there is an addition reaction type as a type that causes a hydrosilylation reaction with a catalyst. Any of these types of curable silicone rubber may be used. In particular, the addition reaction type silicone rubber is more preferable in that it has no by-product accompanying the curing reaction, has a small curing shrinkage, and can easily be cured by heating.

For example, the addition reaction type silicone rubber is formed by a hydrosilylation reaction between a compound containing an alkenyl group bonded to a silicon atom and a compound having a hydrogen atom bonded to a silicon atom. Such materials contain alkenyl groups bonded to silicon atoms such as vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, propenyltrimethoxysilane, norbornenyltrimethoxysilane, octenyltrimethoxysilane, etc. And hydrogen atoms bonded to silicon atoms such as methylhydrogenpolysiloxane, dimethylpolysiloxane-CO-methylhydrogenpolysiloxane, ethylhydrogenpolysiloxane, methylhydrogenpolysiloxane-CO-methylphenylpolysiloxane, etc. Examples thereof include those formed by hydrosilylation reaction of the compounds having them. In addition, other publicly known ones such as those described in JP 2010-159411 A can be used.

By appropriately designing these resins, the storage elastic modulus at room temperature (25 ° C.) and the storage elastic modulus at high temperature (100 ° C.) can be controlled, and a resin useful in the practice of the present invention can be obtained.

Moreover, it is also possible to select and use a commercially available silicone sealing material having an appropriate storage modulus from a general silicone sealing material. Specific examples include OE-6630A / B and OE-6520A / B manufactured by Toray Dow Corning.

(Phosphor)
The phosphor absorbs blue light, violet light, and ultraviolet light emitted from the LED chip, converts the wavelength, and emits red, orange, yellow, green, and blue light with wavelengths different from those of the LED chip. To be released. Thereby, a part of the light emitted from the LED chip and a part of the light emitted from the phosphor are mixed to obtain a multicolor LED including white. Specifically, a white LED can be emitted using a single LED chip by optically combining a blue LED with a phosphor that emits a yellow emission color by light from the LED.

The phosphors as described above include various phosphors such as a phosphor emitting green, a phosphor emitting blue, a phosphor emitting yellow, and a phosphor emitting red. Specific phosphors used in the present invention include known phosphors such as organic phosphors, inorganic phosphors, fluorescent pigments, and fluorescent dyes. Examples of organic phosphors include allylsulfoamide / melamine formaldehyde co-condensed dyes and perylene phosphors. Perylene phosphors are preferably used because they can be used for a long period of time. Examples of the fluorescent material that is particularly preferably used in the present invention include inorganic phosphors. The inorganic phosphor used in the present invention is described below.

Examples of phosphors that emit green light include SrAl ₂ O ₄ : Eu, Y ₂ SiO ₅ : Ce, Tb, MgAl ₁₁ O ₁₉ : Ce, Tb, Sr ₇ Al ₁₂ O ₂₅ : Eu, (Mg, Ca, Sr , At least one of Ba) and Ga ₂ S ₄ : Eu.

Examples of phosphors that emit blue light include Sr ₅ (PO ₄ ) ₃ Cl: Eu, (SrCaBa) ₅ (PO ₄ ) ₃ Cl: Eu, (BaCa) ₅ (PO ₄ ) ₃ Cl: Eu, (Mg, ₂ B ₅ O ₉ Cl: Eu, Mn, (Mg, Ca, Sr, Ba, at least one) (PO ₄ ) ₆ Cl ₂ : Eu, Mn, etc. .

As phosphors emitting green to yellow, at least cerium-activated yttrium / aluminum oxide phosphors, at least cerium-enriched yttrium / gadolinium / aluminum oxide phosphors, at least cerium-activated yttrium / aluminum There are garnet oxide phosphors and at least cerium activated yttrium gallium aluminum oxide phosphors (so-called YAG phosphors). Specifically, Ln ₃ M ₅ O ₁₂ : R (Ln is at least one selected from Y, Gd, and La. M includes at least one of Al and Ca. R is a lanthanoid series. ), (Y _1-x Ga _x ) ₃ (Al _1-y Ga _y ) ₅ O ₁₂ : R (R is at least one selected from Ce, Tb, Pr, Sm, Eu, Dy, Ho) 0 <Rx <0.5, 0 <y <0.5) can be used.

Examples of phosphors that emit red light include Y ₂ O ₂ S: Eu, La ₂ O ₂ S: Eu, Y ₂ O ₃ : Eu, and Gd ₂ O ₂ S: Eu.

As the phosphor corresponding to the current mainstream of the blue LED _{emission, Y 3 (Al, Ga)} 5 O 12: Ce, (Y, Gd) 3 Al 5 O 12: Ce, Lu 3 Al 5 O 12: Ce, Y ₃ Al ₅ O ₁₂ : YAG phosphor such as Ce, TAG phosphor such as Tb ₃ Al ₅ O ₁₂ : Ce, (Ba, Sr) ₂ SiO ₄ : Eu phosphor and Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce phosphor, silicate phosphor such as (Sr, Ba, Mg) ₂ SiO ₄ : Eu, (Ca, Sr) ₂ Si ₅ N ₈ : Eu, (Ca, Sr) AlSiN ₃ : Eu, CaSiAlN ₃ : Nitride phosphor such as Eu, Cax (Si, Al) ₁₂ (O, N) ₁₆ : Oxynitride phosphor such as Eu, and (Ba, Sr, Ca) Si ₂ O ₂ N ₂ : E Examples include phosphors such as u-based phosphors, Ca ₈ MgSi ₄ O ₁₆ Cl ₂ : Eu-based phosphors, SrAl ₂ O ₄ : Eu, and Sr ₄ Al ₁₄ O ₂₅ : Eu.

Of these, YAG-based phosphors, TAG-based phosphors, and silicate-based phosphors are preferably used in terms of luminous efficiency and luminance.

In addition to the above, known phosphors can be used according to the intended use and the intended emission color.

The particle size of the phosphor is not particularly limited, but preferably has a D50 of 0.05 μm or more, more preferably 3 μm or more. Moreover, it is preferable that D50 is 30 μm or less. Here, D50 refers to the particle size when the accumulated amount from the small particle size side is 50% in the volume-based particle size distribution obtained by measurement by the laser diffraction / scattering particle size distribution measurement method. When D50 is in the above range, the dispersibility of the phosphor in the phosphor sheet is good, and stable light emission is obtained.

In the present invention, the phosphor content is not particularly limited, but from the viewpoint of increasing the wavelength conversion efficiency of light emission from the LED chip, it is preferably 30% by weight or more of the entire phosphor sheet, and 40% by weight or more. More preferably. Although the upper limit of the phosphor content is not particularly defined, it is preferably 95% by weight or less of the entire phosphor sheet and 90% by weight or less from the viewpoint that a phosphor sheet excellent in workability can be easily produced. Is more preferably 85% by weight or less, and particularly preferably 80% by weight or less.

The phosphor sheet of the present invention is particularly preferably used for surface coating of LED chips. In that case, the LED light-emitting device which shows the outstanding performance can be obtained because content of the fluorescent substance in a fluorescent substance sheet is the said range.

(Silicone fine particles)
The phosphor sheet in the present invention may contain silicone fine particles in order to improve the fluidity of the resin composition for producing a phosphor sheet and improve the coating property. The silicone fine particles contained are preferably fine particles comprising a silicone resin and / or silicone rubber. In particular, silicone fine particles obtained by a method in which organosilane such as organotrialkoxysilane, organodialkoxysilane, organotriacetoxysilane, organodiacetoxysilane, organotrioxime silane, and organodioxime silane are hydrolyzed and then condensed are obtained. preferable.

Examples of the organotrialkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-proxysilane, methyltri-i-proxysilane, methyltri-n-butoxysilane, methyltri-i-butoxysilane, methyltri-s-butoxy Silane, methyltri-t-butoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, i-propyltrimethoxysilane, n-butyltributoxysilane, i-butyltributoxysilane, s-butyltrimethoxysilane, t -Butyltributoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane and the like are exemplified.

Organodialkoxysilanes include dimethyldimethoxysilane, dimethyldiethoxysilane, methylethyldimethoxysilane, methylethyldiethoxysilane, diethyldiethoxysilane, diethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, N- (2- Aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminoisobutylmethyldimethoxysilane, N-ethylaminoisobutylmethyldiethoxysilane, (phenylaminomethyl) methyldimethoxysilane, vinylmethyl Examples include diethoxysilane.

Examples of organotriacetoxysilane include methyltriacetoxysilane, ethyltriacetoxysilane, vinyltriacetoxysilane, and the like.

Examples of organodiacetoxysilane include dimethyldiacetoxysilane, methylethyldiacetoxysilane, vinylmethyldiacetoxysilane, and vinylethyldiacetoxysilane.

Examples of the organotrioxime silane include methyl trismethyl ethyl ketoxime silane, vinyl trismethyl ethyl ketoxime silane, and examples of the organodioxime silane include methyl ethyl bismethyl ethyl ketoxime silane.

Specifically, such particles are reported in Japanese Unexamined Patent Publication No. 63-77940, Japanese Unexamined Patent Publication No. 6-248081, Japanese Unexamined Patent Publication No. 2003-342370. Or a method reported in JP-A-4-88022. In addition, organosilane such as organotrialkoxysilane, organodialkoxysilane, organotriacetoxysilane, organodiacetoxysilane, organotrioxime silane, organodioxime silane and / or a partial hydrolyzate thereof are added to an alkaline aqueous solution, Hydrolysis / condensation to obtain particles, or addition of organosilane and / or partial hydrolyzate thereof to water or acidic solution to obtain hydrolyzed partial condensate of organosilane and / or partial hydrolyzate thereof Thereafter, a method in which an alkali is added to proceed with a condensation reaction to obtain particles, an organosilane and / or a hydrolyzate thereof is used as an upper layer, an alkali or a mixed solution of an alkali and an organic solvent is used as a lower layer, and the organosilane at these interfaces. And / or hydrolyzate thereof · Polycondensation engaged with is also known a method of obtaining a particle, In any of these methods, it is possible to obtain the particles used in the present invention.

Among these, in order to hydrolyze and condense organosilane and / or its partial hydrolyzate to produce spherical silicone fine particles, polymer dispersants such as water-soluble polymers and surfactants are added to the reaction solution. It is preferable to obtain the silicone fine particles by the method. The water-soluble polymer can be either a synthetic polymer or a natural polymer as long as it acts as a protective colloid in a solvent. Specific examples include water-soluble polymers such as polyvinyl alcohol and polyvinyl pyrrolidone. Any surfactant may be used as long as it has a hydrophilic site and a hydrophobic site in the molecule, thereby acting as a protective colloid. Specifically, anionic surfactants such as sodium dodecylbenzenesulfonate, ammonium dodecylbenzenesulfonate, sodium lauryl sulfate, ammonium lauryl sulfate, sodium polyoxyethylene alkyl ether sulfate, lauryl trimethyl ammonium chloride, stearyl trimethyl ammonium chloride, etc. Cationic surfactants, polyoxyethylene alkyl ethers, polyoxyethylene distyrenated phenyl ethers, polyoxyalkylene alkenyl ethers, ether-based or ester-based nonionic surfactants such as sorbitan monoalkylates, polyether-modified poly Silicone surface activity such as dimethylsiloxane, polyester-modified polydimethylsiloxane, aralkyl-modified polyalkylsiloxane , And fluorine-based surfactants such as perfluoroalkyl group-containing oligomers, and acrylic surfactants. The dispersant may be added in advance to the reaction initial solution, in addition to the organotrialkoxysilane and / or its partial hydrolysate, or in the organotrialkoxysilane and / or its partial hydrolyzate. A method of adding after partial condensation can be exemplified, and any of these methods can be selected. The addition amount of the dispersant is preferably in the range of 5 × 10 ⁻⁷ to 0.1 part by weight with respect to 1 part by weight of the reaction solution. When the lower limit is exceeded, the particles tend to aggregate and form a lump. On the other hand, if the upper limit is exceeded, the amount of dispersant residue in the particles increases, causing coloring.

These silicone particles may be modified on the particle surface with a surface modifier for the purpose of controlling the dispersibility in the matrix components and the wettability. The surface modifier may be modified by physical adsorption or may be modified by a chemical reaction. Specifically, a silane coupling agent, a thiol coupling agent, a titanate coupling agent, an aluminate coupling agent, Although a fluorine-type coating agent etc. are mentioned, since it is strong in heat resistance and there is no hardening inhibition, the modification by a silane coupling agent is especially preferable.

The organic substituent contained in the silicone fine particles is preferably a methyl group or a phenyl group, and the refractive index of the silicone fine particles can be adjusted by the content of these substituents. In order not to reduce the luminance of the LED light-emitting device, when it is desired to use the light passing through the silicone resin as the binder resin without scattering, the refractive index d1 of the silicone fine particles and the refractive index due to components other than the silicone fine particles and the phosphor A smaller refractive index difference of d2 is preferable. The difference in refractive index between the refractive index d1 of the silicone fine particles and the refractive index d2 due to components other than the silicone fine particles and the phosphor is preferably less than 0.10, and more preferably 0.03 or less. By controlling the refractive index within such a range, reflection / scattering at the interface between the silicone fine particles and the silicone composition can be reduced, high transparency and light transmittance can be obtained, and the brightness of the LED light emitting device can be reduced. There is no.

For the measurement of the refractive index, Abbe refractometer, Pulfrich refractometer, immersion type refractometer, immersion method, minimum declination method, etc. are used as the total reflection method, but for the refractive index measurement of the silicone composition, The immersion method is useful for measuring the refractive index of Abbe refractometer and silicone fine particles.

Further, as a means for controlling the refractive index difference, it can be adjusted by changing the amount ratio of the raw materials constituting the silicone fine particles. That is, for example, by adjusting the mixing ratio of methyltrialkoxysilane and phenyltrialkoxysilane, which are raw materials, and increasing the composition ratio of methyl groups, it is possible to achieve a refractive index close to 1.4. On the contrary, a relatively high refractive index can be achieved by increasing the constituent ratio of the phenyl group.

In the present invention, the average particle diameter of the silicone fine particles is represented by a median diameter (D50), and the average particle diameter is preferably 0.01 μm or more and more preferably 0.05 μm or more as a lower limit. The upper limit is preferably 2.0 μm or less, and more preferably 1.0 μm or less. When the average particle size is 0.01 μm or more, it is easy to produce particles with a controlled particle size, and when the average particle size is 2.0 μm or less, the optical properties of the phosphor sheet are improved. Moreover, the fluidity improvement effect of the resin liquid for fluorescent substance sheet manufacture is fully acquired because an average particle diameter is 0.01 micrometer or more and 2.0 micrometers or less. Moreover, it is preferable to use monodispersed true spherical particles. In the present invention, the average particle diameter, that is, the median diameter (D50) and the particle size distribution of the silicone fine particles contained in the phosphor sheet can be measured by SEM (scanning electron microscope) observation of the sheet cross section. A particle size distribution is obtained by performing image processing on a measurement image obtained by SEM, and in the particle size distribution obtained therefrom, the particle diameter of 50% of the accumulated portion from the small particle diameter side is obtained as the median diameter D50. In this case as well, as in the case of the phosphor particles, the average particle size of the silicone fine particles obtained from the cross-sectional SEM image of the phosphor sheet is theoretically 78.5% compared to the true average particle size, and is actually approximately Although the value is 70% to 85%, the average particle size of the silicone fine particles in the present invention is defined as a value obtained by the above-described measuring method.

The content of the silicone fine particles is preferably 1 part by weight or more, more preferably 2 parts by weight or more as a lower limit with respect to 100 parts by weight of the silicone resin. Further, the upper limit is preferably 20 parts by weight or less, and more preferably 10 parts by weight or less. By containing 1 part by weight or more of silicone fine particles, a particularly good phosphor dispersion stabilizing effect can be obtained. On the other hand, the content of 20 parts by weight or less does not excessively increase the viscosity of the silicone composition.

(Other ingredients)
The phosphor sheet of the present invention may further contain an inorganic fine particle filler in order to impart effects such as viscosity adjustment, light diffusion, and coating property improvement. Examples of these orientation fillers include silica, alumina, titania, zirconia, barium titanate, and zinc oxide.

Further, in the present invention, the silicone resin composition used in the preparation of the phosphor sheet has, as other components, a hydrosilylation reaction retarder such as acetylene alcohol in order to suppress curing at room temperature and lengthen the pot life. It is preferable to mix. In addition, a leveling agent for stabilizing the coating film may be added as another additive, and an adhesion aid such as a silane coupling agent may be added as a sheet surface modifier.

(Film thickness)
The film thickness of the phosphor sheet of the present invention is determined from the phosphor content and desired optical properties. Since the phosphor content is limited from the viewpoint of workability as described above, the film thickness is preferably 10 μm or more. On the other hand, from the viewpoint of improving the optical properties and heat dissipation of the phosphor sheet, the thickness of the phosphor sheet is preferably 1000 μm or less, more preferably 200 μm or less, and even more preferably 100 μm or less. By setting the phosphor sheet to a film thickness of 1000 μm or less, light absorption and light scattering by the binder resin and the phosphor can be reduced, so that the phosphor sheet is optically excellent.

Also, if the sheet film thickness varies, the amount of phosphor varies depending on the LED chip, and as a result, the emission spectrum (color temperature, luminance, chromaticity) varies. Therefore, the variation in sheet thickness is preferably within ± 5%, more preferably within ± 3%.

The film thickness of the phosphor sheet in the present invention is a film thickness (average film thickness) measured based on the method A of measuring thickness by mechanical scanning in JIS K7130 (1999) plastic-film and sheet-thickness measurement method. ). Moreover, the film thickness variation of a fluorescent substance sheet is computed based on the following numerical formula using the said average film thickness. More specifically, it is obtained by measuring the film thickness using a micrometer such as a commercially available contact-type thickness meter using the measurement conditions of the method A of measuring the thickness by mechanical scanning. The difference between the maximum value or the minimum value of the film thickness and the average film thickness is calculated, and this value is divided by the average film thickness, and the value expressed in 100 minutes is the film thickness variation B (%).

Film thickness variation B (%) = {(maximum film thickness deviation value−average film thickness) / average film thickness} × 100
Here, as the maximum film thickness deviation value, the one having the larger difference from the average film thickness among the maximum value or the minimum value of the film thickness is selected.

<Support base material>
The support substrate protects the phosphor sheet whose shape is easily deformed, facilitates storage, transportation and processing, and facilitates the operation in the process of attaching to the LED chip, and prevents adhesion and contamination to the pressure substrate. To prevent.

(Physical properties of support substrate)
The supporting substrate has a breaking elongation of 200% or more and a Young's modulus of 600 MPa or less at 23 ° C. When the elongation at break of the supporting substrate is less than 200% or the Young's modulus is greater than 600 MPa, a gap is generated between the side surface and the phosphor sheet in the LED attaching step, and the followability is deteriorated. From the viewpoint of followability to the LED chip, the elongation at break is desirably 300% or more, and more desirably 500% or more. The Young's modulus is desirably 400 MPa or less, more desirably 100 MPa or less, and further desirably 10 MPa or less. Although there is no restriction | limiting in particular about the upper limit of breaking elongation, From a viewpoint with which cutting | disconnection becomes easy, it is preferable that it is 1500% or less, It is more preferable that it is 1000% or less, It is further more preferable that it is 800% or less, 750 % Or less is particularly preferable. The lower limit of Young's modulus is not particularly limited, but is preferably 0.1 MPa or more, more preferably 1 MPa or more, and still more preferably from the viewpoint of protecting the phosphor sheet without deformation of the support base material. Is 1.6 MPa or more.

The elongation at break and Young's modulus can be measured by a method according to ASTM-D882-12. As a specific measurement method, a test piece is pulled at a speed of 300 mm / min using a tensile tester in an environment maintained at a constant temperature. When the length of the test piece before the test is L ₀ and the length of the test piece when cut (broken) is L, the elongation at break is calculated by the following equation.
Elongation at break (%) = 100 × (L−L ₀ ) / L ₀ .

Also, the Young's modulus can be obtained from the maximum elasticity immediately before the specimen is deformed, that is, the maximum slope of the SS curve in which the elongation of the specimen and the load applied thereto are plotted. The number of measurements of the elongation at break and Young's modulus is 3 times to increase the accuracy, and the average value is obtained.

As described above, the attaching temperature of the phosphor sheet is preferably 60 ° C. to 150 ° C., more preferably 60 ° C. to 120 ° C. Therefore, it is preferable that the thermal characteristics of the supporting substrate do not melt in this temperature range. From this viewpoint, the melting point of the supporting substrate is preferably 120 ° C. or higher, and more preferably 150 ° C. or higher.

In addition, from the viewpoint of achieving both the adhesiveness for holding the phosphor sheet and the releasability for peeling off the supporting substrate after being attached to the LED chip, the supporting substrate has a peeling force of 0.5. It is preferably in the range of ~ 2.5N / 20mm. The peeling force referred to here is a value obtained by an adhesive test method by peeling 90 degrees in the adhesive tape / adhesive sheet method defined in JIS Z 0237 (2009).

In general, the support substrate preferably has a surface average roughness Ra of 1 μm or less from the viewpoint of the uniformity of light emission, but may be subjected to surface processing such as embossing to improve light extraction. .

(Support base material)
Specific examples of the material for the supporting substrate include polyvinyl chloride, polyurethane, silicone, low density polyethylene (LDPE), and polyvinyl acetal. Polyvinyl chloride is hard and soft depending on the amount of plasticizer added, but is preferably soft. Silicone includes resin and rubber, and silicone rubber having excellent stretchability is preferable. Of these, polyvinyl chloride, polyurethane or silicone is preferred from the viewpoints of high elongation, low Young's modulus, thermal properties, adhesion and peelability. More preferred is polyvinyl chloride or polyurethane, particularly preferred is soft polyvinyl chloride or polyurethane, and most preferred is polyurethane (polyurethane film).

For these films, the elongation at break and Young's modulus can be controlled within the above preferred ranges by, for example, reducing the density, making no stretching, increasing the amount of monomer of the soft component, and increasing the amount of plasticizer.

(Thickness of support substrate)
The film thickness of the supporting substrate is preferably 5 μm to 500 μm, more preferably 20 μm to 200 μm, and more preferably 40 μm to 100 μm. Moreover, it is preferable that the film thickness of a support base material satisfy | fills the following numerical formula with respect to a fluorescent substance sheet film thickness.

1/5 ≦ (film thickness of supporting substrate / film thickness of phosphor sheet) ≦ 3
If it is more than the lower limit, the supporting substrate can obtain sufficient mechanical strength for protecting the phosphor sheet. Moreover, if it is below an upper limit, in the sticking of a fluorescent substance sheet, sufficient followable | trackability with respect to an LED chip can be obtained. From this viewpoint, the lower limit of (the thickness of the supporting substrate / the thickness of the phosphor sheet) is more preferably ½ or more. The upper limit is more preferably 2 or less, and still more preferably 1 or less.

<Other structures in the laminate>
The laminate of the present invention may have an adhesive on the support substrate. FIG. 2 is an example of a laminate having an adhesive. In this case, the laminate 1 is formed so that the surface to which the adhesive 4 is applied is in contact with the phosphor sheet 3, and the phosphor sheet 3 is fixed on the support base 2 by the adhesive 4. The adhesive strength of the adhesive is preferably 0.1 N / 20 mm or more from the viewpoint of holding the phosphor sheet on the support substrate. Moreover, 1.0 N / 20mm or less is preferable from a viewpoint which peels a support base material after coat | covering a LED chip with a fluorescent substance sheet.

The laminate of the present invention may be provided with a protective substrate on the phosphor sheet for the purpose of protecting the surface of the phosphor sheet. As the protective substrate, a known metal, film, glass, ceramic, paper or the like can be used. Specifically, aluminum (metal plates and foils including aluminum alloys, cellulose acetate, polyethylene terephthalate (PET), polyethylene, polyester, polyamide, polyimide, polyphenylene sulfide, polystyrene, polypropylene, polycarbonate, aramid, fluorine resin, etc. Examples thereof include processed paper such as film, resin-laminated paper, resin-coated paper, etc. It is desirable that the surface of these protective substrates is previously peeled off so that the phosphor sheet does not adhere during storage. In addition, a substrate having a high strength is preferable so that the phosphor sheet does not bend during storage or transportation, or the surface is not damaged. And handling Release-treated PET film or release paper from the surface is more preferable.

<Method for producing laminate>
Although the manufacturing method of the laminated body of this invention may be any method which can form this, the direct coating method, the transfer method by an adhesive, and the thermal transfer method are illustrated.

The direct coating method is a method in which the composition for preparing a phosphor sheet is coated on a supporting substrate and then heat-cured. The details of the “phosphor sheet preparation composition” will be described later. The “phosphor sheet preparation composition” is used as a coating liquid for forming a phosphor sheet, and the phosphor is dispersed in a resin. Composition.

In the transfer method using the adhesive, the adhesive surface of the supporting substrate having the adhesive is bonded to the phosphor sheet produced on the second substrate, and the phosphor sheet is formed on the supporting substrate from the second substrate. This is a method of transferring.

The thermal transfer method is a method in which a phosphor sheet produced on a second substrate is heat-pressed with a support substrate and transferred from the second substrate onto the support substrate.

As a method for producing a laminate, a transfer method using an adhesive and a thermal transfer method are preferable from the viewpoint of producing a phosphor sheet with high film thickness accuracy, and a thermal transfer method from the viewpoint of peelability of the support substrate after the LED chip is attached. Is preferred.

Here, the production of the phosphor sheet will be described. In addition, the following is an example and the preparation method of a fluorescent substance sheet is not limited to this. First, a composition in which a phosphor is dispersed in a resin (hereinafter referred to as “phosphor sheet preparation composition”) is prepared as a coating solution for forming a phosphor sheet. Silicone fine particles may be added for the purpose of suppressing sedimentation of the phosphor, and other additives such as inorganic fine particles, leveling agents and adhesion aids may be added. In addition, when an addition reaction type silicone resin is used as the resin, a pot life can be extended by adding a hydrosilylation reaction retarder. If necessary to make fluidity appropriate, a solvent can be added to form a solution. A solvent will not be specifically limited if the viscosity of resin of a fluid state can be adjusted. For example, toluene, methyl ethyl ketone, methyl isobutyl ketone, hexane, acetone, terpineol and the like can be mentioned.

After preparing these components so as to have a predetermined composition, a phosphor sheet is obtained by uniformly mixing and dispersing with a homogenizer, a revolving stirrer, a three-roller, a ball mill, a planetary ball mill, a bead mill or the like. A composition for preparation is obtained. Defoaming is preferably carried out under vacuum or reduced pressure conditions after mixing or dispersing.

Next, the phosphor sheet preparation composition is applied onto a substrate and dried. Application is reverse roll coater, blade coater, slit die coater, direct gravure coater, offset gravure coater, reverse roll coater, blade coater, kiss coater, natural roll coater, air knife coater, roll blade coater, varibar roll blade coater, toe. A stream coater, rod coater, wire bar coater, applicator, dip coater, curtain coater, spin coater, knife coater or the like can be used. In order to obtain the uniformity of the phosphor sheet thickness, it is preferable to apply with a slit die coater. The phosphor sheet of the present invention can also be produced by using a printing method such as screen printing, gravure printing, or lithographic printing. When using a printing method, screen printing is particularly preferably used.

A general heating device such as a hot air dryer or an infrared dryer is used for drying and curing the phosphor sheet. The heat-curing conditions are usually 80 ° C. to 200 ° C. for 2 minutes to 3 hours, but in order to obtain a so-called B-stage state that can be softened by heating and exhibit adhesiveness, it is 30 minutes to 2 ° C. Heating for hours is preferred.

When using the 2nd base material utilized for the transfer method by an adhesive and a thermal transfer method, a well-known metal, a film, glass, ceramic, paper, etc. can be used without a restriction | limiting in particular. In order to produce a phosphor sheet with high film thickness accuracy, the elongation at break of the second base material is preferably less than 200% or Young's modulus is greater than 600 MPa at 23 ° C., and Young's modulus is particularly 4000 MPa or more. It is more preferable. In addition, a resin that is less deformed at a temperature of 150 ° C. or higher at which the resin curing reaction proceeds rapidly is preferable.

Specifically, metal plates and foils such as aluminum (including aluminum alloys), zinc, copper, iron, cellulose acetate, polyethylene terephthalate (PET), polyethylene, polyester, polyamide, polyimide, polyphenylene sulfide, polystyrene, polypropylene, polycarbonate A film of plastic such as polyvinyl acetal or aramid, a paper laminated with the plastic, or a paper coated with the plastic, a paper laminated or vapor-deposited with the metal, or a plastic film laminated or vapor-deposited with the metal. Can be mentioned.

Among these, a resin film is preferable in view of the above required characteristics and economy, and a PET film or a polyphenylene sulfide film is particularly preferable. Moreover, when a high temperature of 200 ° C. or higher is required when the resin is cured or the phosphor sheet is attached to the LED, a polyimide film is preferable in terms of heat resistance.

Also, in order to facilitate the transfer of the phosphor sheet, it is preferable that the surface of the second base material is previously peeled off.

The thickness of the second substrate is not particularly limited, but the lower limit is preferably 30 μm or more, and more preferably 50 μm or more. Moreover, as an upper limit, 5000 micrometers or less are preferable and 3000 micrometers or less are more preferable.

It is desirable that the transfer from the second base material to the support base material with an adhesive is performed by a laminator with a roller so that air is not caught.

Further, it is desirable that the thermal transfer from the second base material to the support base material is performed by a thermal laminator having a heating mechanism and a pressure mechanism. Here, thermal transfer is preferably performed at 60 ° C. or higher from the viewpoint of softening the phosphor sheet and developing adhesiveness. Moreover, it is preferable to carry out at 120 degrees C or less from a viewpoint of maintaining the B-stage state (namely, semi-hardened state) of a fluorescent substance sheet. Further, from the viewpoint of maintaining film thickness uniformity, the pressure is preferably 0.3 MPa or less, and the pressure time is preferably 30 seconds or less, more preferably 10 seconds or less.

<Method for manufacturing light emitting device>
A method for manufacturing a light emitting device using the laminate of the present invention will be described.

In the present invention, a light emitting device is manufactured by a manufacturing method including a step (covering step) of covering a light emitting surface of an LED chip bonded (mounted) on a substrate with the phosphor sheet of the laminate of the present invention. It is preferable.

Further, in the case where the light emitting surface of the LED chip is the upper surface and side surface of the LED chip, etc., the step of covering the upper surface and side surface of the LED chip bonded (mounted) on the substrate with the phosphor sheet of the laminate of the present invention It is preferable that the light emitting device is manufactured by a manufacturing method having a (coating step).

As described above, in the light emitting device using the laminate of the present invention, after the LED chip is bonded (mounted) on the substrate, the upper light emitting surface and the side light emitting surface of the LED chip are fluorescent using the laminate of the present invention. It is preferable to manufacture by covering with a body sheet.

A board | substrate fixes an LED chip and connects with wiring. The substrate may be a base substrate or a submount substrate, for example. The material of the substrate is not particularly limited, but resin such as polyphthalamide (PPA), liquid crystal polymer, silicone, ceramic such as aluminum nitride (AlN), alumina (Al ₂ O ₃ ), boron nitride (BN), aluminum Etc. can be exemplified.

Use a substrate on which an electrode pattern is formed, for example, with silver. Further, a heat dissipation mechanism may be provided.

The LED chip preferably emits blue light or ultraviolet light. As such an LED chip, a gallium nitride LED chip is particularly preferable.

The type of the LED chip may be any of a lateral type, a vertical type, and a flip chip type, but the flip chip type is particularly preferable from the viewpoint of high luminance and high heat dissipation. In the present invention, the LED chip is bonded (mounted) on the substrate is preferably in a state where the LED chip is electrically bonded to the substrate. Examples of flip chip bonding (mounting) include solder bonding, eutectic bonding, and conductive paste bonding.

The LED chips may be bonded (mounted) independently on the substrate, or a plurality of LED chips may be bonded (mounted). Each package may be covered with a phosphor sheet, or a plurality of packages arranged together may be covered with a phosphor sheet and then separated by dicing or the like.

The film thickness of the LED chip is not particularly limited, but is preferably 500 μm or less, more preferably 300 μm or less from the viewpoint of reducing the pressure applied to the phosphor sheet on the upper surface and corners of the LED chip and maintaining the film thickness uniformity. More preferably, it is 200 μm or less.

Moreover, it is preferable that the total film thickness of the connection portion between the LED chip and the substrate and the film thickness of the phosphor sheet satisfy the following relational expression.

1 ≦ (total film thickness of connection part with LED chip and substrate / film thickness of phosphor sheet) ≦ 10.

If it is above the lower limit, it is easy to suppress the uneven orientation of the emission color. Moreover, it is easy to maintain a phosphor sheet thickness uniformity as it is below an upper limit. From this viewpoint, the lower limit is preferably 2 or more. The upper limit is preferably 5 or less, and more preferably 4 or less.

The affixing of the laminate of the present invention to the LED chip is preferably performed under heating conditions because it softens the phosphor sheet and develops adhesiveness. The heating temperature is preferably 60 ° C. to 150 ° C., more preferably 60 ° C. to 120 ° C., since the phosphor sheet is sufficiently softened and rapid curing does not proceed.

Moreover, it is preferable that the laminate is attached to the LED chip under a pressurized condition from the viewpoint of improving the followability to the side surface of the chip. The pressure is preferably 0.1 MPa to 0.3 MPa because the phosphor sheet can be pressed against the side surface of the LED chip and the film thickness can be maintained.

As a pressing method, specifically, a method of inflating and pressing a flexible sheet, a method of injecting a gas such as air and pressing without contact, a method of pressing and pressing a mold along the shape of the LED chip, or The method of pressing with a roll is illustrated. A plurality of these methods may be combined.

Furthermore, it is preferable that the laminate is attached to the LED chip under a vacuum atmosphere condition in order to prevent air from being caught between the phosphor sheet and the LED chip and the substrate.

The apparatus for applying the laminate to the LED chip using the laminate of the present invention is not particularly limited as long as the above conditions are satisfied. However, since it is versatile and excellent in productivity, it is flexible on the platen. A vacuum laminating apparatus having a vacuum chamber provided with a pressure-clamping mechanism provided with is preferable. An example of such a vacuum laminating apparatus is described in Japanese Patent No. 3660442.

An example of a method for manufacturing a light emitting device using such a vacuum laminating apparatus will be described with reference to FIG. This vacuum laminating apparatus includes an upper platen 6, a flexible sheet 8, a sealed space 9 surrounded by them, a pressing mechanism 11 having an air inlet / outlet port 10, a lower platen 7 having a heater, and another air. The vacuum chamber 5 is provided with an injection / discharge port 12. On this lower platen 7, a substrate 13 to which an LED chip 14 is bonded (mounted) is placed, and a laminate 1 including a support base 2 and a phosphor sheet 3 is further disposed on the surface of the LED chip. They are superimposed one after another in the direction of contact (FIG. 3a). Next, air is discharged (vacuum) from the air injection / discharge port 10 and the air injection / discharge port 12 in the direction indicated by the dotted line in FIG. The inside of 9 is made into a vacuum atmosphere (FIG. 3b). Next, air is injected into the sealed space 9 of the pressure-clamping mechanism 11 by injecting air from the air injection / discharge port 10 in the direction of the arrow in FIG. 3C while heating the lower platen 7 with a heater (not shown). Then, the flexible sheet 8 is expanded to attach the laminate 1 to the LED chip 14 (FIG. 3c). Next, air is injected from the air injection / discharge port 12 in the direction of the arrow in FIG. 3d, thereby injecting air into the vacuum chamber 5 and returning to normal pressure (FIG. 3d), and taking out the light emitting device 15 (FIG. 3). 3e). Finally, the support base 2 is removed from the laminate 1 attached to the light emitting device 15 (FIG. 3f). Thus, it is preferable that the light emitting device according to the present invention has a configuration that does not include a support base material as shown in FIG. This is because the light emitting device is often used or distributed in a configuration in which the support base material is removed from the laminate of the light emitting device.

Thus, by using the laminate of the present invention, the phosphor sheet can be coated on the LED chip with a single step of pressing, and a method for manufacturing a light-emitting device with high productivity can be provided.

Further, for example, in the conventional two-stage pressing method as described in Patent Document 2, that is, the method of continuously performing contact pressing by a flexible sheet and non-contact pressing by air injection, the laminate of the present invention is also used. It can be used suitably.

In particular, when a plurality of LED chips arranged at intervals of 1000 μm or less on a substrate are covered with a phosphor sheet, sufficient application accuracy (covering system) cannot be obtained even if the two-stage pressing method is simply used. There is a tendency. However, even in such a case, it is possible to perform coating with high accuracy by using the two-stage pressing method and additionally using the laminate of the present invention in which a supporting base material having a low Young's modulus is used. it can.

<Light emitting device>
A light emitting device obtained using the laminate of the present invention will be described. FIG. 4 is a schematic view of a cross-section and an upper surface of a light-emitting device (one example) in which the LED chip 14 bonded to the substrate 13 via the bumps 18 (for example, gold bumps) is covered with the phosphor sheet 3.

4 is a schematic diagram of the top surface of the light emitting device. Here, 16 indicates a covering portion on the upper surface and side surface of the LED chip, and 17 indicates a covering portion on the base material.

On the other hand, a cross section of the light emitting device is shown in the upper part of FIG. The cross-sectional view shown in the upper part of FIG. 4 shows, for example, that at the position of the broken line II in the top view. The cross section of the chip coated with such a phosphor sheet is prepared by exposing the cross section by a mechanical polishing method or an ion polishing method (including a cross section polishing method), and then using a digital microscope or SEM ( It can be confirmed by a method of observing with a scanning electron microscope) or a method of observing by non-destructive X-ray CT scanning without passing through a cross-sectional preparation step such as polishing.

The light emitting device includes at least a substrate, an LED chip bonded (mounted) on the substrate, and a phosphor sheet that covers the light emitting surface of the LED chip. Here, the light emitting surface refers to the surface from which the LED light is extracted. Examples of the classification by light emitting surface include a type in which light is extracted from the upper surface and side surfaces such as a flip chip type and a lateral type chip, and a type in which light is extracted only from the upper surface such as a vertical type. Further, a type in which a flip-chip side reflecting layer is provided so that light can be extracted only from the upper surface can be given as an example. Further, a transparent resin may be present between the phosphor sheet and the light emitting surface of the LED for the purpose of imparting adhesiveness. Here, examples of the transparent resin include thermosetting resins such as acrylic, epoxy, and silicone. Among these, silicone resins are most preferable from the viewpoints of heat resistance and light resistance.
Among the above, the phosphor sheet preferably covers the upper surface and the side surface of the LED chip from the viewpoint of widening the emission angle and reducing azimuth unevenness. More preferably, the phosphor sheet covers and directly adheres the upper surface and side surfaces of the LED chip. By using the laminate of the present invention, the phosphor sheet attached from the laminate is coated in direct contact with 80% or more of the upper light emitting surface area and 50% or more of the side light emitting area of the LED chip. Can be produced. Ultimately, it is also possible to produce a light emitting device in which the phosphor sheet attached from the laminate is coated in direct contact with 100% or more of the upper light emitting surface area of the LED chip and 50% or more of the side light emitting area. Is possible.

Here, “direct contact” refers to a state in which the phosphor sheet and the upper light emitting surface or the side light emitting surface of the LED chip are bonded without any voids. In covering the LED chip upper light emitting surface, if there are few direct contact portions, the phosphor sheet is easily peeled off, which may cause a failure of the light emitting device. In the present invention, if the direct contact portion is substantially 80% or more of the LED chip upper light emitting surface area, the phosphor sheet is hardly peeled off, and the defect of the light emitting device can be suppressed. From this viewpoint, it is more preferable that the directly adhered portion is 90% or more of the upper light emitting surface area, and it is most preferable that it is substantially 100%. When the cross section of the LED chip covered with the phosphor sheet is observed at a magnification of 500 times using a microscope, the direct adhesion portion is substantially 100% with respect to the area of the light emitting surface of the LED chip. The state of the phosphor sheet that is in direct contact with the LED chip (light emitting surface) is 100%.

Also, if an air layer with a small refractive index exists between the light emitting surface of the LED chip and the phosphor sheet, the light extraction efficiency is lowered. Therefore, in the covering to the side light emitting surface of the LED chip, if the direct contact portion is substantially less than 50% of the side light emitting area of the LED chip, the light emission efficiency from the side surface of the LED chip is lowered and the luminance is lowered. There is. That is, in covering the side light emitting surface of the LED chip, when the direct contact portion is 50% or more of the side light emitting area of the LED chip, it is possible to suppress a decrease in light extraction efficiency from the side surface of the LED chip. From this point of view, the direct contact portion is preferably 70% or more of the LED chip side light emitting area, and more preferably 90% or more.

In the light emitting device obtained by using the laminate of the present invention, it is preferable that the film thickness of the phosphor sheet covering the LED chip is small in any part from the viewpoint of suppressing the uneven orientation of light emission. Since the light emission intensity from the side surface is weaker than the light emission from the top surface of the chip, the film thickness of the side surface portion of the LED chip is preferably thinner than the film thickness of the top surface portion of the chip. Here, the uneven azimuth of light emission means that the light appearance of the light emitting device varies depending on the angle. Such orientation unevenness is caused by a color temperature at a distance 10 cm vertically away from the upper surface of the LED chip of the light emitting device (hereinafter referred to as a vertical color temperature) and a color temperature at a distance 10 cm above obliquely 45 ° (hereinafter referred to as 45 °). It can be determined by the absolute value of the difference in color temperature. In the present invention, the smaller the absolute value of the difference, the smaller the uneven azimuth of light emission, which is preferable.

From this point of view, in the present invention, the distance from the upper surface of the LED chip 14 to the outer surface of the phosphor sheet 3 in the portion (region) where the LED chip 14 and the phosphor sheet 3 are in contact with each other on the upper surface of the LED chip 14 is defined as a distance a. [Μm] When the distance from the side surface of the LED chip 14 to the outer surface of the phosphor sheet 3 is a distance b [μm] in a portion (region) where the LED chip 14 and the phosphor sheet 3 are in contact with each other on the side surface of the LED chip 14 From the viewpoint of suppressing light emission unevenness, the relationship of 0.80 <a / b <1.50 is preferably satisfied, 1.00 <a / b <1.20 is more preferable, and 1.00 <a / More preferably, b <1.05.

That is, in the light emitting device of the present invention, it is preferable that the relationship [a / b] satisfies the above-described range. Further, when manufacturing such a light emitting device, it is preferable to adopt a manufacturing method in which the relationship [a / b] satisfies the above-described range in the obtained light emitting device.

Therefore, a preferable manufacturing method for obtaining the light emitting device according to the present invention is an LED chip (particularly, light emission of the LED chip) bonded on the substrate with the phosphor sheet of the laminated body of the present invention so as to satisfy the above relationship. A step (covering step) for covering the surface or the upper surface and the side surface.

Thus, the manufacturing method for obtaining the light emitting device according to the present invention is a method for manufacturing a light emitting device in which the above relationship is satisfied in the step of covering with the phosphor sheet of the laminate of the present invention (covering step). Preferably there is.

Hereinafter, the present invention will be described in detail by way of examples.

<Phosphor sheet>
・ Silicone resin 1:
Resin main component (MeViSiO _2/2 ) _0.25 (Ph ₂ SiO _2/2 ) _0.3 (PhSiO _3/2 ) _0.45 (HO _1/2 ) _0.03 75 parts by weight Hardness modifier ViMe ₂ SiO (MePhSiO) _17.5 SiMe ₂ Vi 10 Part by weight Crosslinker (HMe ₂ SiO) ₂ SiPh ₂ 25 parts by weight * However, Me: methyl group, Vi: vinyl group, Ph: phenyl group reaction inhibitor 1-ethynylhexanol 0.025 parts by weight Platinum catalyst Platinum (1,3 -Divinyl-1,1,3,3-tetramethyldisiloxane) complex 1,3-divinyl-1,1,3,3-tetramethyldisiloxane solution [platinum content 5% by weight] 0.01 parts by weight Silicone resin 2: KER6075 (manufactured by Shin-Etsu Chemical Co., Ltd.).
Phosphor 1: NYAG-02 (manufactured by Intematix: Ce-doped YAG phosphor, specific gravity: 4.8 g / cm ³ , D50: 7 μm).

(Method for measuring storage elastic modulus of phosphor sheet)
Measuring device: Viscoelasticity measuring device ARES-G2 (TA Instruments)
Geometry: Parallel disk type (15mm)
Strain: 1%
Angular frequency: 1 Hz
Temperature range: 25 ° C to 140 ° C
Temperature increase rate: 5 ° C./min Measurement atmosphere: In air.
Sixteen phosphor sheets having a film thickness of 50 μm were stacked and heat-pressed on a hot plate at 100 ° C. to produce an integrated film (sheet) having a thickness of 800 μm, and cut into a diameter of 15 mm to obtain a measurement sample. This sample was measured using the above conditions, and the storage elastic modulus at 25 ° C. and 100 ° C. was measured.

(Method for producing phosphor sheet)
[Production Example 1 of phosphor sheet]
Using a polyethylene container having a volume of 300 ml, the silicone resin 1 was mixed at a ratio of 30% by weight and the phosphor 1 was mixed at a ratio of 70% by weight. Thereafter, using a planetary stirring and defoaming apparatus “Mazerustar KK-400” (manufactured by Kurabo Industries), stirring and defoaming were carried out at 1000 rpm for 20 minutes to obtain a phosphor dispersion for sheet preparation. Using a slit die coater, a phosphor dispersion for sheet preparation is applied as a base material to a peeled surface of “Therapy” WDS (manufactured by Toray Film Processing Co., Ltd .; film thickness 50 μm, elongation at break 115%, Young's modulus 4500 MPa). And it heated and dried at 120 degreeC for 1 hour, and obtained the fluorescent substance sheet 1 with a film thickness of 50 micrometers and a 100 mm square. The storage elastic modulus of this phosphor sheet was 1.0 MPa at 25 ° C. and 0.025 MPa at 100 ° C.

[Production Example 2 of phosphor sheet]
A phosphor sheet 2 having a film thickness of 50 μm and a 100 mm square was obtained in the same manner as in Production Example 1 except that the silicone resin 2 was used instead of the silicone resin 1. The storage elastic modulus of this phosphor sheet was 1.1 MPa at 25 ° C. and 0.35 MPa at 100 ° C.

<Laminate>
(Supporting substrate)
The elongation at break and the Young's modulus at 23 ° C. of the support substrate were measured three times using Tensilon RTF-1310 (manufactured by A & D) according to ASTM-D882-12, and the average value was obtained. .
Sample size: width 10mm, initial length 30mm
Measurement conditions: Temperature 23 ° C., pulling speed 300 mm / min.
Support substrate 1: Polyurethane film MG90 (manufactured by Takeda Sangyo)
Film thickness 50μm, elongation at break 500%, Young's modulus 8MPa
Support substrate 2: polyurethane film MG90 (manufactured by Takeda Sangyo)
Film thickness 100μm, elongation at break 750%, Young's modulus 8MPa
-Support base material 3: Polyvinyl chloride film (soft) Type C + (Achilles)
Film thickness 50μm, elongation at break 350%, Young's modulus 250MPa
Support substrate 4: Polyvinyl chloride film with adhesive T-80MW (manufactured by Denki Kagaku Kogyo)
Film thickness 50μm, elongation at break 300%, Young's modulus 300MPa
・ Supporting substrate 5: Silicone film Silica (Mitsubishi Resin)
Film thickness 50μm, elongation at break 450%, Young's modulus 1.6 MPa
Support substrate 6: ethylene-tetrafluoroethylene copolymer (ETFE) film NEOFLON EF-0050 (manufactured by Daikin)
Film thickness 50 μm, elongation at break 450%, Young's modulus 640 MPa.

[Production Example 1]
The support substrate 1 was placed on the phosphor sheet 1 formed on “Therapy” WDS, and was pressed at a temperature of 80 ° C., a pressure of 0.3 MPa, and a feed rate of 0.5 m / min using a roll-type thermal laminator. . After allowing to cool to room temperature, “Therapy” WDS was peeled off to obtain a laminate 1.

[Production Example 2]
A laminate 2 was obtained in the same manner as in Production Example 1 except that the phosphor sheet 2 was used instead of the phosphor sheet 1.

[Production Example 3]
A laminate 3 was obtained in the same manner as in Production Example 1 except that the support substrate 2 was used instead of the support substrate 1.

[Production Example 4]
A laminate 4 was obtained in the same manner as in Production Example 1 except that the support substrate 3 was used instead of the support substrate 1.

[Production Example 5]
On the phosphor sheet 1 formed on “Therapy” WDS, the support base material 4 is placed so that the pressure-sensitive adhesive layer is in contact with the phosphor layer, and a temperature of 25 ° C., a pressure of 0.3 MPa is applied using a roll laminator, Pressing at a feed rate of 1.0 m / min. After allowing to cool to room temperature, “Therapy” WDS was peeled off to obtain a laminate 5.

[Production Example 6]
The support substrate 5 was placed on the phosphor sheet 1 formed on “Therapy” WDS, and was pressed at a temperature of 80 ° C., a pressurizing pressure of 0.3 MPa, and a feed rate of 0.5 m / min using a roll-type thermal laminator. . After allowing to cool to room temperature, “Therapy” WDS was peeled off to obtain a laminate 6.

[Production Example 7]
A laminated body 67 was obtained in the same manner as in Production Example 1 except that the supporting substrate 6 was used instead of the supporting substrate 1.

In addition, the laminated body of the "therapeutic" WDS and the fluorescent substance sheet 1 which were produced in the manufacture example 1 of the fluorescent substance sheet was used as the laminated body 8.

<Light emitting element>
(Paste device)
A vacuum laminator V130 (manufactured by Nichigo Morton) as shown in FIG. 3 having a vacuum chamber, a lower platen connected to a heater, and a pressing mechanism comprising an upper platen and a flexible fluorosilicone rubber sheet. Used.

(Evaluation of light appearance of light emitting device)
The difference between the color temperature at a distance 10 cm vertically away from the upper surface of the LED chip of the light emitting device (hereinafter referred to as “vertical color temperature”) and the color temperature at a distance 10 cm away obliquely above 45 ° (hereinafter referred to as “45 ° color temperature”). The absolute value was obtained and judged as follows.

A: | (Vertical color temperature)-(45 ° color temperature) | <500K
B: 500K ≦ | (vertical color temperature) − (45 ° color temperature) | <1000K
C: 1000K ≦ | (vertical color temperature) − (45 ° color temperature) |.

(Followability evaluation method)
For the light emitting device in which the LED chip is bonded to the substrate and covered with the phosphor sheet, the cross section is cut by the SEM after cutting the cross section so as to be perpendicular to the substrate at the positions I, II and III shown in FIG. Was taken. Next, the ratio of the part which the fluorescent substance sheet is contacting with respect to the upper light emission surface of LED chip was calculated from each sectional drawing. In FIG. 4, A / D = 1/10, B / D = 5/10, and C / D = 9/10.

Similarly, the ratio of the portion where the phosphor sheet is in contact with the side light emitting surface of the LED chip was calculated. The average value of the measurement results at three locations for each was regarded as the followability to the upper light emitting surface and the followability to the side light emitting surface, and the followability was evaluated according to the following criteria.

A: The followability of the LED upper light emitting surface is 100% and the followability of the side light emitting surface is 90% or more. B: The followability of the LED upper light emitting surface is 100% and the followability of the side light emitting surface is 70. %: Less than 90% C: The followability of the LED upper light emitting surface is 100% and the followability of the side light emitting surface is 50% or more but less than 70% D: The followability of the LED upper light emitting surface is 90% or more and less than 100% Or, the followability of the side light emitting surface is 40% or more and less than 50% E: The followability of the LED upper light emitting surface is less than 90%, or the followability of the side light emitting surface is less than 40%.

(Thickness uniformity evaluation)
From the cross-sectional view obtained by the SEM obtained by the follow-up evaluation method described above, from the upper surface of the LED chip 14 to the outer surface of the phosphor sheet 3 in the portion where the LED chip 14 and the phosphor sheet 3 are in contact with each other on the upper surface of the LED chip 14. Distance a was measured (see FIG. 4). Similarly, the distance b from the side surface of the LED chip 14 to the outer surface of the phosphor sheet 3 at the portion where the LED chip 14 and the phosphor sheet 3 are in contact with each other on the side surface of the LED chip 14 was measured (see FIG. 4). . When measuring the distance a and the distance b, it was measured as three significant figures. The value of a / b was obtained by rounding off the third decimal place, and the film thickness uniformity was evaluated according to the following criteria.

A: 1.00 <a / b <1.05
B: 1.05 ≦ a / b <1.20
C: 0.80 <a / b ≦ 1.00 or 1.20 ≦ a / b <1.50
D: When a / b ≦ 0.80 or 1.50 ≦ a / b, or when evaluation is impossible.

[Example 1]
An LED chip having a size of 1 mm square and a thickness of 150 μm was bonded to an alumina ceramic substrate provided with electrodes via a gold bump of 10 μm thickness. Subsequently, the laminated body 1 was cut into 3 mm squares, and was superposed so that the phosphor sheet surface thereof was in contact with the upper surface of the bonded LED chip. This was placed on the lower platen in the vacuum chamber of the vacuum laminator. Subsequently, the lower platen was heated to 80 ° C., and then the vacuum chamber was sealed. The inside of the vacuum chamber was reduced to 0.001 MPa by a vacuum pump, and then maintained for 30 seconds. Thereafter, 0.1 MPa of air was fed into the pressure-clamping mechanism to expand the fluorosilicone rubber sheet, and the laminate 1 was pressed for 10 seconds so as to follow the shape of the LED chip. Subsequently, the vacuum chamber was broken (that is, vacuum chamber air was injected to make the atmospheric pressure (0.1 MPa)), and the light emitting device coated with the phosphor sheet was taken out. However, at this stage, the coated phosphor sheet is still in the B stage (semi-cured state).

After removing the supporting substrate from the light emitting device, the phosphor sheet was sufficiently cured by heating in a constant temperature oven heated to 150 ° C. for 2 hours to obtain a final light emitting device. By supplying a current of 30 mA to the obtained light emitting device, the light emitting device is caused to emit light, and the vertical color temperature at a position 10 cm away from the LED chip light emitting surface in the vertical direction (perpendicular direction) and the vertical line from the LED chip light emitting surface. The appearance of light was evaluated by measuring the 45 ° color temperature at a position 10 cm away in a direction where the angle between the angle and the angle was 45 ° (an oblique 45 ° direction). Subsequently, the light-emitting element for which light appearance was evaluated was cut in a cross-section so as to be perpendicular to the substrate, and a cross-sectional view was taken with an SEM. The followability and film thickness uniformity were evaluated from this cross-sectional view.

[Examples 2 to 6]
A light emitting device was obtained in the same manner as in Example 1 except that the laminate described in Table 1 was used. The obtained light-emitting device was evaluated in the same manner as in Example 1 for the appearance of light, the followability, and the film thickness uniformity.

[Comparative Examples 1 and 2]
A light emitting device was obtained in the same manner as in Example 1 except that the laminate described in Table 1 was used. The obtained light-emitting device was evaluated in the same manner as in Example 1 for the appearance of light, the followability, and the film thickness uniformity.

From the results of the examples, at 23 ° C., by using a laminate having a supporting base material having a breaking elongation of 200% or more and a Young's modulus of 600 MPa or less and a phosphor sheet, followability and film thickness uniformity are provided on the LED chip. It was found that it can be covered with the phosphor sheet while keeping.

Further, when these light emitting devices were caused to emit light, the light emitting elements of the examples emitted light uniformly from any direction, but the light emitting elements of the comparative example looked slightly dark when observed from an oblique direction. As a result, it was found that azimuth unevenness occurred.

As described above, in the light emitting device that can be pasted with excellent followability and film thickness uniformity using the laminate of the present invention, there is a difference between the color temperature in the vertical direction of the LED chip and the color temperature in the oblique 45 ° direction. It has been found that the azimuth unevenness can be suppressed.

DESCRIPTION OF SYMBOLS 1 Laminated body 2 Support base material 3 Phosphor sheet 4 Adhesive material (adhesive layer)
5 Vacuum chamber 6 Upper platen 7 Lower platen 8 Flexible sheet 9 Sealed space (for pressure clamping mechanism)
10 Air inlet / outlet (for clamping mechanism)
11 Clamping mechanism 12 Air inlet / outlet (for vacuum chamber)
DESCRIPTION OF SYMBOLS 13 Substrate 14 LED chip 15 Light-emitting device 16 Cover part 17 in LED chip upper surface and side face Cover part 18 in base material Bump (for example, gold bump)

Claims (7)

1. A laminate including a supporting substrate and a phosphor sheet containing a phosphor and a resin, the elongation at break at 23 ° C. of the supporting substrate determined by a tensile test is 200% or more, and the supporting group The laminated body whose Young's modulus in 23 degreeC of a material is 600 Mpa or less.
2. The layered product according to claim 1 whose Young's modulus in 23 ° C of said support substrate is 400 Mpa or less.
3. The layered product according to claim 1 whose Young's modulus in 23 ° C of said support substrate is 100 Mpa or less.
4. The laminate according to any one of claims 1 to 3, wherein the supporting substrate is polyvinyl chloride or polyurethane.
5. The manufacturing method of the light-emitting device which has a process (coating process) which coat | covers the light emission surface of the LED chip joined on the board | substrate with the fluorescent substance sheet of the laminated body in any one of Claim 1 to 4.
6. The manufacturing method of the light-emitting device which has the process (coating process) which coat | covers the upper surface and side surface of the LED chip joined on the board | substrate with the fluorescent substance sheet of the laminated body in any one of Claim 1 to 4.
7. A method of manufacturing a light emitting device according to claim 5 or 6,
   The distance a [μm] from the upper surface of the LED chip to the outer surface of the phosphor sheet at the portion where the LED chip and the phosphor sheet are in contact with each other on the upper surface of the LED chip, and the LED chip and the phosphor sheet on the side surface of the LED chip The distance b [μm] from the side surface of the LED chip to the outer surface of the phosphor sheet in the contacting portion is
   1.00 <a / b <1.20
   A method for manufacturing a light-emitting device that satisfies the above relationship.

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