JP2013252637A - Fluorescent substance sheet laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent substance sheet excellent in a property of being stuck on an LED chip and also excellent in separation into individual pieces and pattern processing.SOLUTION: In a fluorescent substance sheet laminate, a protective film, a fluorescent substance sheet and a base film are stacked. Adhesive strength (A) between the protective film and the fluorescent substance sheet at room temperature is in a range of ≥0.015 N/cm and ≤0.05 N/cm, and adhesive strength (B) between the base film and the fluorescent substance sheet at room temperature is in a range of ≥0.6 N/cm and ≤2.0 N/cm.

Description

  The present invention relates to a phosphor sheet laminate in which a phosphor-containing sheet is provided on a substrate. More specifically, the present invention relates to a phosphor sheet laminate in which a sheet-like phosphor material for converting the emission wavelength of an LED chip is provided on a substrate.

  Light emitting diodes (LEDs) are used for backlights of liquid crystal displays (LCDs) and car headlights with low power consumption, long life, and design, etc. due to their remarkable improvement in luminous efficiency. The market is rapidly expanding in the automotive field. Since LEDs have a low environmental impact, it is expected to form a huge market in the general lighting field in the future.

  Since the emission spectrum of an LED depends on the semiconductor material forming the LED chip, its emission color is limited. Therefore, in order to obtain white light for an LCD backlight or general illumination using an LED, it is necessary to install a phosphor suitable for each chip on the LED chip and convert the emission wavelength. Specifically, a method of installing a yellow phosphor on an LED chip that emits blue light, a method of installing red and green phosphors on a blue LED chip, a red, green, and blue color on an LED chip that emits ultraviolet light A method of installing a phosphor has been proposed. Among these, from the viewpoint of luminous efficiency and cost of the LED chip, the method of installing yellow phosphors on blue LEDs and the method of installing red and green phosphors on blue phosphors are currently the most widely used. It has been adopted.

  As a specific method of installing the phosphor on the LED chip, a method of dispersing the phosphor in a liquid resin for sealing the LED chip has been proposed (for example, Patent Document 1). ~ 2). However, if the phosphor is not uniformly dispersed in the liquid resin, color misregistration occurs for each LED chip.

  Therefore, a method of using a sheet-like resin layer (phosphor sheet) in which a fluorescent material is uniformly distributed in advance has been proposed (see, for example, Patent Documents 3 to 8). This method is easier to dispose a certain amount of phosphor on the LED chip than the conventional method of dispensing and curing a liquid resin in which the phosphor is dispersed on the LED chip. The resulting white LED is excellent in that the color and brightness can be made uniform.

JP-A-5-152609 JP-A-7-99345 Japanese Patent No. 4146406 JP 2000-156528 A JP 2009-235368 A JP 2010-123802 A Japanese Patent No. 2011-102004 JP 2010-159411 A

  Every year, there is a demand for reduction in manufacturing costs of LED light-emitting devices, and members used in LED light-emitting devices are one of important selection criteria not only in performance but also in productivity. The same can be said for the phosphor sheet. However, when an LED light-emitting device is manufactured using a conventional phosphor sheet, particularly a high-density phosphor sheet excellent in light resistance, the productivity is not sufficient.

  This is because of the following problems. In general, a phosphor sheet has a configuration in which a phosphor sheet is laminated on a base film and a protective film is provided on the uppermost surface. When manufacturing an LED light-emitting device using such a phosphor sheet, the protective film is first peeled off, the peeled surface is attached to the LED chip, and then the base film is peeled off. During the process, there was a problem that troubles such as the protective film and the base film not being peeled off from the phosphor sheet occurred. In addition, when it is necessary to divide the phosphor sheet with the protective film and the base material film pasted into it, and to perform patterning by cutting or punching, the processed portion of the phosphor sheet at such processing There was also a problem that cracking and chipping occurred. In particular, the high-concentration phosphor sheet contains a lot of hard phosphor particles, so that cracks and chips are likely to occur.

  In view of such a situation, an object of the present invention is to provide a phosphor sheet that is excellent in adhesion to an LED chip and that is excellent in singulation and pattern processing. Another object is to increase the productivity of the LED light emitting device.

The present invention seeks to achieve both stickability to LED chips and pattern processability by optimizing the relationship between the adhesive strength of the phosphor sheet, the protective film, and the base film. That is, the present invention is a phosphor sheet laminate in which a protective film, a phosphor sheet and a base film are laminated, and the adhesive strength (A) between the protective film and the phosphor sheet at room temperature and at room temperature. The adhesive strength (B) between the substrate film and the phosphor sheet is A = 0.015 N / cm or more and 0.05 N / cm or less B = 0.6 N / cm or more and 2.0 N / cm or less. It is the fluorescent substance sheet laminated body characterized.

  ADVANTAGE OF THE INVENTION According to this invention, the fluorescent substance sheet which can be easily installed and adhere | attached on the LED chip surface and was excellent in pattern workability can be provided.

Schematic showing an example of a flip chip type LED chip Schematic showing an example of a face-up type LED chip Schematic showing an example of a face-up type LED chip

  In the present invention, the phosphor sheet refers to a sheet mainly containing a phosphor and a resin. Other components may be included as necessary. Details of the components contained in the phosphor sheet will be described later.

  As a result of earnest studies on the sticking property and workability of the phosphor sheet, the inventors have obtained a protective film, a phosphor sheet, and a phosphor sheet laminate in which a substrate film is laminated. And the range and relationship of the adhesive strength between the base film and the phosphor sheet were found to be important.

  The present invention is a phosphor sheet laminate in which a protective film, a phosphor sheet, and a base film are laminated, and the adhesive strength (A) between the protective film and the phosphor sheet at room temperature and the room temperature The adhesive strength (B) between the base film and the phosphor sheet is A = 0.015 N / cm or more and 0.05 N / cm or less, and B = 0.6 N / cm or more and 2.0 N / cm or less. The present invention relates to a featured phosphor sheet laminate. By making the adhesive strength within the above range, both the pastability and workability are improved.

  From the viewpoint of workability, the adhesive strength A needs to be 0.015 N / cm or more and 0.05 N / cm or less. Adhesive strength A has a great influence on processability, and if it is less than 0.015 N / cm, the phosphor sheet is easily cracked or the protective film is peeled off during processing. If the adhesive strength A is greater than 0.05 N / cm, the processability is good, but the protective film is difficult to peel off, and cracking and chipping occur in the phosphor sheet during peeling. In the present invention, the adhesive strength A is particularly preferably 0.02 N / cm or more and 0.03 N / cm in terms of workability.

  Further, from the viewpoint of sticking property, the adhesive strength B needs to be 0.6 N / cm or more and 2.0 N / cm or less. Adhesive strength B has a large effect on the adhesiveness, and if it is less than 0.6 N / cm, it can be easily attached to the LED chip, but the phosphor sheet is easily peeled off from the base film during handling and processing. Therefore, since the phosphor sheet cannot be fixed, as a result, the phosphor sheet is easily cracked or peeled off during processing. If the adhesive strength is greater than 2.0 N / cm, the handling and workability will be good, but the base film will be difficult to peel off, and the phosphor sheet will be cracked or chipped during peeling. In the present invention, the adhesive strength B is particularly preferably 0.6 N / cm or more and 1.2 N / cm or less in terms of stickability.

  In the present invention, the affixability refers to the ease of affixing the phosphor sheet to the LED chip. When the protective film or the base film is easily peeled off from the phosphor sheet and the phosphor sheet after being attached is not cracked or chipped, it can be said that the sticking property is good.

  On the other hand, the processability in the present invention indicates the ease of singulation and pattern processing of the phosphor sheet. As processing methods of the phosphor sheet laminate, there are cutting processing (dividing into pieces) and punching processing (pattern processing).

  First, a method for cutting the phosphor sheet laminate will be described. The method of attaching the phosphor sheet to the LED element includes a method of cutting the phosphor sheet into individual pieces before attaching to the LED element, and attaching the phosphor sheet to individual LED elements, and a method of attaching the phosphor to the wafer level LED element. There is a method in which a phosphor sheet is cut in a lump together with wafer dicing after the sheet is attached. In the case of cutting in advance before sticking, the uniformly formed phosphor sheet is processed into a predetermined shape by laser processing or cutting with a blade and divided. At this time, the base film and the protective film remain attached to the phosphor sheet. Since processing with a laser gives high energy, it is very difficult to avoid scorching of the resin and deterioration of the phosphor, and cutting with a blade is desirable. As a cutting method with a blade, there are a method of pushing and cutting a simple blade and a method of cutting with a rotary blade, both of which can be suitably used. As an apparatus for cutting with a rotary blade, an apparatus used for cutting (dicing) a semiconductor substrate called a dicer into individual chips can be suitably used. If the dicer is used, the width of the dividing line can be precisely controlled by the thickness of the rotary blade and the condition setting, so that higher processing accuracy can be obtained than when cutting with a simple cutting tool. In either case, the whole substrate may be separated into individual pieces, or the phosphor sheet may be separated into individual pieces while the substrate is not cut. Alternatively, the substrate is also preferably used in so-called half cut in which a cut line that does not penetrate is entered.

  The drilling process will be described. Although known methods such as laser processing and die punching can be suitably used for drilling, laser processing causes burning of the resin and deterioration of the phosphor, so punching with a die is more desirable. When punching is performed, punching cannot be performed after the phosphor sheet is attached to the LED element. Therefore, it is essential to perform punching before attaching. At this time, the base film and the protective film remain attached to the phosphor sheet. Punching with a mold can open a hole of any shape or size depending on the electrode shape of the LED element to be attached. Any size and shape of the hole can be formed by designing the mold, but the electrode joint portion on the LED element inside and outside the 1 mm square is preferably 500 μm or less so as not to reduce the area of the light emitting surface. The hole is formed with a size of 500 μm or less in accordance with its size. In addition, an electrode for performing wire bonding or the like needs to have a certain size and is at least about 50 μm. Therefore, the hole is about 50 μm in accordance with the size. If the size of the hole is too larger than the electrode, the light emitting surface is exposed, light leakage occurs, and the color characteristics of the LED light emitting device deteriorate. On the other hand, if it is too small than the electrode, the wire touches at the time of wire bonding, resulting in poor bonding. Therefore, pattern processing needs to process a small hole of 50 μm or more and 500 μm or less with high accuracy within ± 10%.

  Since both processes are performed while the base film and the protective film are adhered to the phosphor sheet, peeling of these films tends to be a problem. Further, when the protective film is peeled off, the phosphor sheet may be cracked or chipped at the processed portion at the peeled off place. It can be said that the workability is good when the protective film is not peeled off during the processing as described above, and the processed portion of the phosphor sheet is not cracked or chipped.

  The adhesive strength in this invention means the strength measured by the method according to the measuring method A of the peeling strength of copper foil in the JIS C6471 (1995) copper clad laminated board test method for flexible printed wiring boards. In the case of the adhesive strength of the protective film, the peel strength of the protective film from the phosphor sheet is measured. In the case of the adhesive strength of the base film, the peel strength of the base film from the phosphor sheet is measured.

  In order to adjust the adhesive strength, first, the tackiness of the phosphor sheet is important. The adhesiveness of the phosphor sheet is determined by the type of resin used, the type of phosphor, the phosphor content, and the drying conditions during sheet preparation. Therefore, when adjusting adhesive strength, it is necessary to select the base film and protective film which suited the adhesiveness of the fluorescent substance sheet, and to adjust adhesive strength. In that case, a method of adjusting the adhesive strength by a treatment with a release agent for the base film and a treatment with an adhesive for the protective film is preferably used.

  The material of the protective film used in the present invention is not particularly limited, but cellulose acetate, polyethylene terephthalate (PET), polyethylene, polyester, polyamide, polyimide, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, aramid, polyphenylene sulfide, etc. Examples thereof include a plastic film, paper coated with plastic (polyethylene, polypropylene, polystyrene, etc.), coated paper, paper or plastic film on which a metal as described above is laminated or vapor-deposited. Among these, PET film is preferable in terms of economy and handleability. Moreover, when high temperature is required for hardening of resin, a polyimide film is preferable in terms of heat resistance. In the present invention, in order to balance the adhesive strength with the phosphor sheet, it is preferable that the adhesive is treated with an adhesive or the like. Examples of the pressure-sensitive adhesive include general rubber-based, acrylic-based, urethane-based, and silicone-based pressure-sensitive adhesives. Any adhesive may be used, but a silicone-based adhesive is useful as an adhesive suitable for heat resistance, insulation, and transparency. Although there is no restriction | limiting in particular in the film thickness of a protective film, 20 micrometers or more are preferable as a minimum, and 50 micrometers or more are more preferable. Moreover, as an upper limit, 300 micrometers or less are preferable and 150 micrometers or less are more preferable.

  There is no restriction | limiting in particular as a base film used for this invention, A well-known film, coated paper, etc. can be used. Specifically, cellulose acetate, polyethylene terephthalate (PET), polyethylene, polyester, polyamide, polyimide, polystyrene, polypropylene, polycarbonate, polyvinyl acetal, aramid, polyphenylene sulfide, and other plastic films (plastic, polyethylene, polypropylene, polystyrene, etc.) Is a laminated or coated paper, a paper or a plastic film on which a known metal such as aluminum (including an aluminum alloy), zinc, copper or iron is laminated or vapor-deposited. Among these, PET film is preferable in terms of economy and handleability. Moreover, when high temperature is required for hardening of resin, a polyimide film is preferable in terms of heat resistance. In order to balance the adhesive strength with the phosphor sheet, it is preferable that the surface of the base film is subjected to a mold release treatment in advance. Although there is no restriction | limiting in particular in the film thickness of a base film, 20 micrometers or more are preferable as a minimum, and 60 micrometers or more are more preferable. Moreover, as an upper limit, 5000 micrometers or less are preferable and 3000 micrometers or less are more preferable.

  Next, the composition and production method of the phosphor sheet used in the present invention will be described.

(Phosphor)
The phosphor absorbs light emitted from the LED chip, converts the wavelength, and emits light having a wavelength different from that of the LED chip. 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 that emits green light, a phosphor that emits blue light, a phosphor that emits yellow light, and a phosphor that emits red light. Specific phosphors used in the present invention include known phosphors such as inorganic phosphors, organic 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. in _{a), (Y 1-x Ga} x) 3 (Al 1-y Ga y) 5 O 12:. R (R is, Ce, Tb, Pr, Sm , Eu, Dy, at least 1 or more selected from Ho 0 <x <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.

  Among these, YAG-based phosphors, TAG-based phosphors, and silicate-based phosphors are preferably used in terms of light emission efficiency and luminance.

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

  The phosphor is preferably in the form of particles. The average particle diameter of the phosphor is not particularly limited, but preferably has a D50 of 0.05 μm or more, more preferably 3 μm or more. Further, those having a D50 of 30 μm or less are preferred, and those having a D50 of 20 μm or less are more preferred. Here, in the present invention, the average particle diameter means a median diameter, that is, D50. The D50 of the phosphor contained in the phosphor sheet is obtained by subjecting a measurement image of a cross section of the sheet with a scanning electron microscope (SEM) to image processing to obtain a particle size distribution, and in the volume-based particle size distribution obtained therefrom, Is measured by a method in which the particle diameter of 50% of the accumulated amount from is set to the median diameter D50. The value of D50 obtained by this method is smaller than that obtained by directly observing the phosphor powder, but the average particle diameter of the phosphor in the present invention is defined as the value obtained by the above 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.

  The reason why the value of D50 is smaller than when the phosphor powder is directly observed is that the diameter is correctly measured when the powder is directly observed, but the cross section of the phosphor sheet is measured. This is because the phosphor particles are not always cut at the equator plane. Assuming that the phosphor particles are spherical and are cut at any location, the apparent diameter is theoretically 78.5% of the true diameter (the area of a circle with a diameter of 1 and one side of 1 Equivalent to the square area ratio). Actually, since the phosphor particles are not true spheres, it is empirically about 70% to 85%.

  In this invention, it is preferable that content of the fluorescent substance in a fluorescent substance sheet is 53 weight% or more of the whole sheet | seat. Moreover, it is still more preferable that it is 57 weight% or more of the whole sheet | seat, and it is more preferable that it is 60 weight% or more. The light resistance of a sheet | seat can be improved by making fluorescent substance content in a sheet | seat into the said range. Although the upper limit of the phosphor content is not particularly defined, it is preferably 95% by weight or less, more preferably 90% by weight or less of the entire sheet from the viewpoint of easy creation of a sheet having excellent workability. It is preferably 85% by weight or less, more preferably 80% by weight or less.

  The phosphor content in the phosphor sheet of the present invention can be determined from a prepared sheet or an LED light emitting device equipped with the sheet. For example, by embedding a phosphor sheet with a resin and cutting it, preparing a sample with a polished cross section, and observing the exposed cross section with a scanning electron microscope (SEM), the resin portion and the phosphor particle portion are separated. It is possible to distinguish clearly. From the area ratio of the cross-sectional image, it is possible to accurately measure the volume ratio of the phosphor particles in the entire sheet. When the specific gravity of the resin and the phosphor forming the sheet is clear, the weight ratio of the phosphor to the sheet can be calculated by dividing the volume ratio by the specific gravity. If the composition of the resin or phosphor is not clear, the composition can be determined by analyzing the cross section of the phosphor sheet by high-resolution micro-infrared spectroscopy or IPC emission analysis. If the composition becomes clear, the specific gravity specific to the substance of the resin or phosphor can be estimated with a considerable degree of accuracy, and the weight ratio can be obtained using this. Also, in the case of an LED light-emitting device equipped with a phosphor sheet, disassemble the LED light-emitting device, take out the phosphor sheet portion, and observe the cross section by the same method to determine the weight ratio of the phosphor in the phosphor sheet. Can be sought. By such a method, even if the charging ratio at the time of phosphor sheet production is not clear, by the above method or other known analysis methods, the prepared sheet and the LED light emitting device on which the phosphor sheet is mounted can be used in the phosphor sheet. It is possible to confirm the phosphor weight ratio.

(resin)
The resin used in the present invention is a resin containing a phosphor inside, and finally forms a sheet. Therefore, any resin may be used as long as the phosphor can be uniformly dispersed therein and a sheet can be formed. Specifically, silicone resin, epoxy resin, polyarylate resin, PET modified polyarylate resin, polycarbonate resin (PC), cyclic olefin, polyethylene terephthalate resin (PET), polymethyl methacrylate resin (PMMA), polypropylene resin (PP ), Modified acrylic (Sanjure Kaneka Chemical), polystyrene resin (PE), acrylonitrile / styrene copolymer resin (AS), and the like. 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.

  The silicone resin used in the present invention is preferably a curable silicone rubber. 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.

  As an example, the addition reaction type silicone rubber is formed by a hydrosilylation reaction of 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, for example, known ones as described in JP 2010-159411 A can be used.

  Moreover, it is also possible to use the silicone sealing material for general LED use as what is marketed. Specific examples include OE-6630A / B and OE-6336A / B manufactured by Toray Dow Corning, and SCR-1012A / B and SCR-1016A / B manufactured by Shin-Etsu Chemical Co., Ltd.

  In the silicone resin composition for producing the phosphor sheet in the present invention, it is preferable to blend a hydrosilylation reaction retarder such as acetylene alcohol as other components in order to suppress curing at room temperature and lengthen the pot life. . In addition, as long as the effect of the present invention is not impaired, fine particles such as fumed silica, glass powder, quartz powder, etc., inorganic fillers and pigments such as titanium oxide, zirconia oxide, barium titanate, zinc oxide, You may mix | blend adhesiveness imparting agents, such as a flame retardant, a heat resistant agent, antioxidant, a dispersing agent, a solvent, a silane coupling agent, and a titanium coupling agent.

  In particular, from the viewpoint of the surface smoothness of the phosphor sheet, it is preferable to add a low molecular weight polydimethylsiloxane component, silicone oil or the like to the silicone resin composition for producing the phosphor sheet. Such components are preferably added in an amount of 100 to 2,000 ppm, more preferably 500 to 1,000 ppm, based on the entire composition.

  In forming the phosphor sheet, a resin liquid containing the phosphor of the phosphor sheet forming material is first prepared. However, when the concentration of the phosphor particles in the resin liquid is high, the fluidity of the resin liquid deteriorates. Thereby, the distribution of the phosphor particles in the obtained phosphor sheet becomes non-uniform, and the fluidity is poor, so that the coating is hindered and the film thickness becomes non-uniform. If these are non-uniform, the brightness of the light emitting device using the final LED and the color of white light will be non-uniform. According to the present invention, the fluidity of the resin liquid is greatly improved by containing the silicone fine particles, and the film thickness uniformity of the resulting phosphor sheet is greatly improved.

  The phosphor sheet used in the present invention preferably contains silicone fine particles. By containing the silicone fine particles, it is possible to obtain a phosphor sheet having not only adhesiveness and workability but also good film thickness uniformity. In particular, by using silicone fine particles having an average particle size of 0.1 μm or more and 2.0 μm or less, it is possible to obtain a phosphor sheet that is excellent in dischargeability and excellent in film thickness uniformity when a slit die coater is used. it can.

  The silicone fine particles contained in the phosphor sheet in the present invention are preferably fine particles comprising a silicone resin and / or silicone rubber. In particular, silicone fine particles obtained by a method of hydrolyzing organosilane such as organotrialkoxysilane, organodialkoxysilane, organotriacetoxysilane, organodiacetoxysilane, organotrioxime silane, organodioxime silane, and then condensing them. 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 Examples include -butyltributoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, and phenyltrimethoxysilane.

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

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

  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, the reaction as reported in Japanese Patent Application Laid-Open No. 2003-342370 in producing spherical organopolysilsesquioxane fine particles by hydrolyzing and condensing organosilane and / or a partial hydrolyzate thereof. It is preferable to use silicone particles obtained by a method of adding a polymer dispersant in the solution.

  In the production of particles, organosilane and / or a partial hydrolyzate thereof are hydrolyzed / condensed in the presence of a polymer dispersant and a salt that act as a protective colloid in a solvent in an acidic aqueous solution. Silicone particles produced by adding silane and / or a hydrolyzate thereof to obtain a hydrolyzate and then adding an alkali to advance the condensation reaction can also be used.

The polymer dispersant is a water-soluble polymer, and any synthetic polymer or natural polymer can be used as long as it acts as a protective colloid in a solvent. Specifically, polyvinyl alcohol, polyvinyl pyrrolidone and the like can be used. It can be illustrated. As a method for adding the polymer dispersant, a method of adding in advance to the reaction initial solution, a method of adding organotrialkoxysilane and / or a partial hydrolyzate thereof simultaneously, an organotrialkoxysilane and / or a partial hydrolyzate thereof, The method of adding after hydrolyzing partial condensation can be illustrated, and any of these methods can be selected. Here, the addition amount of the polymer dispersant is preferably in the range of 5 × 10 ⁻⁷ to 10 ⁻² parts by weight with respect to 1 part by weight of the reaction liquid volume, and in this range, aggregation of particles hardly occurs.

  The organic substituents contained in the silicone fine particles are preferably a methyl group and 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 between the refractive index d1 of the silicone particles and the refractive index d2 of the components other than the silicone particles and the phosphor is preferably less than 0.10, and more preferably 0.03 or less. By controlling the refractive index in such a range, reflection / scattering at the interface between the silicone particles and the silicone composition is reduced, high transparency and light transmittance can be obtained, and the brightness of the LED light emitting device is lowered. 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 refractometers and silicone particles.

  The means for controlling the refractive index difference can be adjusted by changing the amount ratio of the raw materials constituting the silicone 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). The lower limit of the average particle diameter is preferably 0.1 μm or more, and more preferably 0.5 μm or more. The upper limit is preferably 2.0 μm or less, and more preferably 1.0 μm 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 can be measured by SEM observation. 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. If this method is used, the volume-based particle size obtained from the particle size distribution of the silicone fine particles is obtained by observing the cross-sectional SEM of the phosphor sheet and then calculating the average particle size of the silicone fine particles themselves. In the distribution, it is also possible to obtain a particle diameter of 50% accumulated from the small particle diameter side 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 determined 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 70. % To 85%.

  The content of the silicone fine particles is preferably 1 part by weight or more and more preferably 2 parts by weight or more as a lower limit with respect to 100 parts by weight of the 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, by containing 20 parts by weight or less, the viscosity of the composition is not excessively increased.

(Sheet production method)
The phosphor sheet used in the present invention and the method for producing the phosphor sheet laminate of the present invention will be described. In addition, the following is an example and the manufacturing method of a fluorescent substance sheet and a fluorescent substance sheet laminated body is not limited to this. First, a solution in which a phosphor is dispersed in a resin (hereinafter referred to as “sheet-forming resin solution”) is prepared as a sheet-forming coating solution. The resin liquid for sheet preparation can be obtained by mixing phosphor and resin in a suitable solvent. When an addition reaction type silicone resin is used, when a compound containing an alkenyl group bonded to a silicon atom and a compound having a hydrogen atom bonded to a silicon atom are mixed, the curing reaction may start even at room temperature. Therefore, it is possible to further extend the pot life by adding a hydrosilylation reaction retarder such as an acetylene compound to the resin liquid for sheet preparation. Further, it is also possible to mix a dispersing agent or leveling agent for stabilizing the coating film as an additive, and an adhesion assistant such as a silane coupling agent as a sheet surface modifier, and the like in the sheet preparation resin liquid. It is also possible to mix silicone fine particles and other inorganic particles such as silica and alumina into the resin liquid for sheet preparation.

  When it is necessary to add a solvent to adjust the viscosity, the type of the solvent is not particularly limited as long as the viscosity of the resin in a fluid state can be adjusted. For example, toluene, methyl ethyl ketone, methyl isobutyl ketone, hexane, heptane, cyclohexane, acetone, terpineol, butyl carbitol, butyl carbitol acetate, glyme, diglyme and the like can be mentioned.

  After preparing these components to have a predetermined composition, they are mixed and dispersed homogeneously by a homogenizer, a self-revolving stirrer, a three-roller, a ball mill, a planetary ball mill, a bead mill, etc. A resin liquid is obtained. Defoaming is preferably carried out under vacuum or reduced pressure conditions after mixing or dispersing.

  Next, the resin liquid for sheet preparation is apply | coated on a base film, and is dried. Application is reverse roll coater, blade coater, slit die coater, direct gravure coater, offset gravure coater, reverse roll coater, blade coater, kiss coater, screen printing, natural roll coater, air knife coater, roll blade coater, varibar roll blade. A coater, a two stream coater, a rod coater, a wire bar coater, an applicator, a dip coater, a curtain coater, a spin coater, a knife coater or the like can be used. In order to obtain the uniformity of the sheet thickness, it is preferable to apply with a slit die coater. The phosphor sheet of the present application can also be produced by using a printing method such as screen printing, gravure printing, or lithographic printing. In particular, screen printing is preferably used.

  The phosphor sheet can be dried using a general heating device such as a hot air dryer or an infrared dryer. For heating and curing the sheet, a general heating device such as a hot air dryer or an infrared dryer is used. In this case, the heat curing conditions are usually 40 to 250 ° C. for 1 minute to 5 hours, preferably 100 ° C. to 200 ° C. for 2 minutes to 3 hours.

  The protective film can be installed using a general laminator apparatus. In some cases, it is also preferable to use a thermal laminator or a vacuum laminator.

  Examples of the LED chip to which the phosphor sheet laminate of the present invention can be applied include a flip chip type (FIG. 1), a vertical type (FIG. 2), a face-up type (FIG. 3), and the like. In any type, the phosphor sheet 1 is affixed to the light emitting surface of the LED chip 2 excluding the electrode 3, and the electrode 3 and the circuit board 4 are joined using a metal wire 5 such as gold ( In particular, there are a vertical type and a face-up type), a method using a metal paste such as a silver paste, and a method using a gold or solder bump (particularly a flip chip type). In the present invention, a flip chip type LED chip or a vertical type is particularly preferably used. Flip chip type and vertical type LED chips have high luminous efficiency and high heat dissipation. Therefore, by using the phosphor sheet laminate of the present invention, it becomes easy to produce a high-power LED for illumination use having excellent light resistance.

  A method for producing an LED light-emitting device using the phosphor sheet laminate of the present invention will be described. In addition, the following description is an example and a manufacturing method is not restricted to these. When applied to a flip chip type LED chip, first, the phosphor sheet laminate is separated into pieces according to the size of the LED chip. Individualization can be performed by dicing or cutting. In the present invention, since the relationship between the adhesive strength A and the adhesive strength B is adjusted, the protective film and the base film can be separated into individual pieces.

  Next, after peeling off the protective film, an individualized sheet is attached to a surface (light extraction surface) opposite to the electrode formation surface of the LED chip. At this time, the phosphor sheet may be in a semi-cured state or may be cured in advance. Adhesive is preferably used for pasting, and known die bond agents and adhesives such as acrylic resin, epoxy resin, urethane resin, silicone resin, modified silicone resin, phenol resin, polyimide, Polyvinyl alcohol, polymethacrylate resin, melamine resin, and urea resin adhesives can be used. If the phosphor sheet has an adhesive, it may be used. In the case of a semi-cured phosphor sheet, curing by heating may be used. In addition, when the phosphor sheet has heat softening properties after curing, it can be bonded by heat fusion. Then, affixing a fluorescent substance sheet on a LED chip upper surface is completed by peeling a base film.

  Then, the light emitting device can be obtained by electrically connecting the electrode of the LED chip and the wiring of the circuit board by a known method. When the LED chip has an electrode on the light emitting surface side, the LED chip is fixed to the circuit board with a die bonding material or the like with the light emitting surface facing up, and then the wire on the upper surface of the LED chip and the circuit board are connected by wire bonding To do. Further, when the LED chip is a flip chip type having an electrode pad on the opposite surface of the light emitting surface, the electrode surface of the LED chip is opposed to the wiring of the circuit board and connected by batch bonding.

  When the phosphor sheet is attached to the LED chip in a semi-cured state, it can be cured at a suitable timing before or after this electrical connection. For example, in the case where the flip chip type is collectively bonded, when the thermocompression bonding is performed, the phosphor sheet may be simultaneously cured by the heating. Further, in the case where a package in which an LED chip and a circuit board are connected is surface-mounted on a larger circuit board, the phosphor sheet may be cured simultaneously with soldering by solder reflow.

  In the case where the phosphor sheet is bonded to the LED chip in a cured state, it is not necessary to provide a curing process after the LED chip is bonded to the LED sheet. The case where the phosphor sheet is attached to the LED chip in a cured state includes, for example, a case where the cured phosphor sheet has a separate adhesive layer, and a case where the phosphor sheet has heat-fusibility after curing. is there. The phosphor sheet may also serve as a sealing agent for the LED chip, but the LED chip to which the phosphor sheet is attached can be further sealed using a known silicone resin or the like as a translucent sealing material. Moreover, after sealing an LED chip with a translucent sealing material, it is also possible to use a phosphor sheet on the sealing material.

  Moreover, when applying to a face-up type LED chip, after making a fluorescent substance sheet into pieces like the above, it affixes on the light extraction surface of an LED chip. When the phosphor sheet is in a semi-cured state, the sheet is cured after being attached. Here, in the face-up type LED chip, at least one electrode is formed on the light extraction surface, and conduction is obtained from this electrode by wire bonding or the like as described later. Therefore, the phosphor sheet is pasted so that at least a part of the electrode is exposed. Of course, it may be attached only to the light extraction portion. In this case, the phosphor sheet can be patterned so that a part of the electrode is exposed.

  Then, the light emitting device can be obtained by fixing the surface opposite to the light extraction surface of the LED chip to the circuit board and electrically connecting the LED chip and the circuit board by a known method such as wire bonding. .

  As another modification, an individual phosphor sheet may be attached to the LED chip mounted on the substrate. Conversely, a plurality of LED chips may be attached to the phosphor sheet and then dicing for each LED chip with a sheet by dicing. It is also possible to attach an undivided phosphor sheet to a semiconductor wafer with LED chips on the surface, and then dice the semiconductor wafer and the phosphor sheet at once to separate them. .

  The light emitting device to which the LED chip obtained by using the phosphor sheet laminate of the present invention can be applied is not particularly limited, such as a backlight of a display used in a television, a personal computer, a mobile phone, a game machine, a car headlight, etc. It can be widely applied to in-vehicle field, general lighting, etc.

  Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to these.

<Measurement of adhesive strength>
For the phosphor sheet laminate, the digital force gauge “FGN-5B” (Nidec Corporation) is based on the measurement method A of the peel strength of the copper foil in the JIS C6471 (1995) copper-clad laminate test method for flexible printed wiring boards. Shinpo Co., Ltd.), electric vertical force gauge test stand “FGS-50-VB-L (H)” (Nidec Sympo Co., Ltd.), 90 ° peeling jig “FGTT-12” (Nidec Sympo Co., Ltd.) ) As a measuring device, and double-sided tape “NW-R15” (manufactured by Nichiban Co., Ltd.) is used to fix the sample. Adhesive strength between the protective film and the phosphor sheet and adhesion between the base film and the phosphor sheet The strength was measured.

<Pasteability evaluation>
(Preparation of pasted sample)
A glass substrate “MICRO SLIDE GLASS S9224” (manufactured by Matsunami Glass Industrial Co., Ltd.) was placed on a hot plate heated to 80 ° C. After the protective film of the phosphor sheet laminate separated into 4 mm square was peeled off, it was placed on the glass substrate so that the phosphor sheet surface was in contact with the glass substrate. The glass substrate was moved from the hot plate to a metallic bat and returned to room temperature to prepare a pasted sample.

(Attachability evaluation)
Using the pasted sample, the phosphor sheet when the base film was peeled off by holding the end on the base film side was visually observed. If there are no cracks or film peeling marks on the phosphor sheet, it indicates that the adhesion is excellent. If it is more than evaluation B, it is excellent practically.
A: No cracks or peeling marks are generated in the adhered phosphor sheet: the pasting property is very good.
B: Cracks are not generated in the adhered phosphor sheet, but peeling marks are generated: Adhesiveness is good.
C: Peeling marks are not generated on the attached phosphor sheet, but cracks are generated: Adhesiveness is poor.
D: Attached phosphor sheet cracks and peeling marks are generated: Attaching property is very bad.

<Processability evaluation>
The obtained phosphor sheet laminate was attached to a punching machine “MP-7150Z” (manufactured by UHT) with a circular mold having a diameter of 200 μm, and pattern processing of 100 holes at a pitch size of 1 mm was performed from the protective film side. . After peeling off the protective film, the processed holes were observed with an optical microscope, and the number of holes without cracks or chips in the periphery was counted. The smaller the number of holes that are cracked or missing in the periphery, the better the pattern workability. If it is more than evaluation B, it is excellent practically.
S: Number of cracks and chips 0 to 10 Workability is very good.
A: Number of cracks and chips 11 or more and 20 or less Good workability.
B: Number of cracks and chips 21 or more and 30 or less There is no practical problem in workability.
C: Number of cracks and chips 31 to 50 The workability is poor.
D: Number of cracks and chips 51 or more Workability is very poor.

<Average particle size measurement>
The average particle size of the synthesized silicone fine particles was calculated from an image obtained by measuring a cross-sectional SEM of each phosphor sheet sample. The cross section of the phosphor sheet was observed with a scanning electron microscope (Hitachi High-Technologies high resolution field emission scanning electron microscope S-4800). The obtained image was analyzed using analysis software (Image version 6.2) to determine the particle diameter distribution. In the particle diameter distribution, the particle diameter of 50% accumulated from the small particle diameter side was determined as the median diameter (D50).

<Luminance retention and light resistance test>
10 packages with LED with phosphor sheet sealed with transparent resin are produced, 20mA current is passed to turn on the LED chip, and test is performed using an instantaneous multi-photometry system (MCPD-3000, manufactured by Otsuka Electronics Co., Ltd.). The luminance immediately after the start was measured, and the average value of 10 pieces was taken as the luminance.

  Thereafter, the LED chip was left in the lit state, the luminance after 300 hours elapsed was measured in the same manner, and the light resistance was evaluated by calculating the luminance retention rate according to the following formula. It shows that it is excellent in light resistance, so that a luminance retention is high. If the rating is B or higher, there is no practical problem.

Luminance retention rate (%) = (luminance after 300 hours / luminance immediately after the start of the test) × 100
(Rounded to the first decimal place)
S: Retention rate 95% or more Light resistance is very good.
A: Retention rate 90 to 94% Good light resistance.
B: Retention rate 80 to 89% Light resistance has no practical problem.
C: Retention rate 50 to 79% Poor light resistance

<Ejection evaluation>
When applying the resin liquid for sheet preparation with a slit die coater, the ease of discharging the resin from the die when the discharge pressure was 0.1 Pa was evaluated.
A: Resin is discharged within 3 seconds after the start of discharge.
B: Resin is discharged within 10 seconds over 3 seconds after the start of discharge.
C: Resin is discharged over 10 seconds after the discharge starts.

(Synthesis of silicone fine particles)
<Silicone fine particles 1>
Attach stirrer, thermometer, reflux tube and dropping funnel to 2L four-necked round bottom flask. Put 2L of 2.5% ammonia water containing 1ppm of polyether-modified siloxane "BYK333" as a surfactant into the flask. The temperature was raised in an oil bath while stirring at. When the internal temperature reached 50 ° C., 200 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 30 minutes. Stirring was continued for 60 minutes at the same temperature, then about 5 g of acetic acid (special grade reagent) was added, mixed with stirring, and then filtered. The product particles on the filter were added with 600 mL of water twice and 200 mL of methanol once, followed by filtration and washing. The cake on the filter was taken out, crushed, and freeze-dried over 10 hours to obtain 60 g of white powder. The obtained particles were monodisperse spherical fine particles as observed by SEM. As a result of measuring the refractive index of this fine particle by the immersion method, it was 1.54. As a result of observing the particles with a cross-sectional TEM, it was confirmed that the particles had a single structure.

<Silicone fine particles 2>
Attach stirrer, thermometer, reflux tube and dropping funnel to 2L four-neck round bottom flask, and put 2L of 2.5% ammonia water containing 7ppm of polyether modified siloxane "BYK333" as surfactant into the flask, 300rpm The temperature was raised in an oil bath while stirring at. When the internal temperature reached 50 ° C., 200 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 30 minutes. Stirring was continued for 60 minutes at the same temperature, then about 5 g of acetic acid (special grade reagent) was added, mixed with stirring, and then filtered. The product particles on the filter were added with 600 mL of water twice and 200 mL of methanol once, followed by filtration and washing. The cake on the filter was taken out, crushed, and freeze-dried for 10 hours to obtain 40 g of white powder. The obtained particles were monodisperse spherical fine particles as observed by SEM. As a result of measuring the refractive index of this fine particle by the immersion method, it was 1.54. As a result of observing the particles with a cross-sectional TEM, it was confirmed that the particles had a single structure.

<Silicone fine particles 3>
A 1 L four-necked round bottom flask was equipped with a stirrer, thermometer, reflux tube, and dropping funnel, and 600 g of caustic soda aqueous solution having a pH of 12.5 (25 ° C.) was added to the flask, and the temperature was raised in an oil bath while stirring at 300 rpm. . When the internal temperature reached 50 ° C., 60 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 20 minutes. Stirring was continued for 30 minutes at the same temperature, and then 16.5 g of 10% aqueous acetic acid solution was added as a neutralizing agent, mixed with stirring, and then filtered. The product particles on the filter were added with 300 mL of water three times and 200 mL of methanol once, followed by filtration and washing. The cake on the filter was taken out and dried at 150 ° C. for 2 hours to obtain 15 g of white powder. The obtained particles were monodisperse spherical fine particles as observed by SEM. As a result of measuring the refractive index of this fine particle by the immersion method, it was 1.54. As a result of observing the particles with a cross-sectional TEM, it was confirmed that the particles had a single structure.

<Silicone fine particles 4>
A 2 L four-necked round bottom flask was equipped with a stirrer, thermometer, reflux tube and dropping funnel, and 2 L of 2.5% ammonia water was added to the flask, and the temperature was raised in an oil bath while stirring at 300 rpm. When the internal temperature reached 50 ° C., 200 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 30 minutes. Stirring was continued for 60 minutes at the same temperature, then about 5 g of acetic acid (special grade reagent) was added, mixed with stirring, and then filtered. The product particles on the filter were added with 600 mL of water twice and 200 mL of methanol once, followed by filtration and washing. The cake on the filter was taken out, crushed, and freeze-dried for 10 hours to obtain 80 g of white powder. The obtained particles were monodispersed spherical fine particles as observed by SEM. As a result of measuring the refractive index of this fine particle by the immersion method, it was 1.54. As a result of observing the particles with a cross-sectional TEM, it was confirmed that the particles had a single structure.

<Silicone fine particles 5>
A 1 L four-necked round bottom flask was equipped with a stirrer, thermometer, reflux tube, and dropping funnel, and 600 g of caustic soda aqueous solution having a pH of 12.5 (25 ° C.) was added to the flask, and the temperature was raised in an oil bath while stirring at 200 rpm. . When the internal temperature reached 50 ° C., 60 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 20 minutes. Stirring was continued for 30 minutes at the same temperature, and then 16.5 g of 10% aqueous acetic acid solution was added as a neutralizing agent, mixed with stirring, and then filtered. The product particles on the filter were added with 300 mL of water three times and 200 mL of methanol once, followed by filtration and washing. The cake on the filter was taken out and dried at 150 ° C. for 2 hours to obtain 10 g of white powder. The obtained particles were monodispersed spherical fine particles as observed by SEM. As a result of measuring the refractive index of this fine particle by the immersion method, it was 1.52. As a result of observing the particles with a cross-sectional TEM, it was confirmed that the particles had a single structure.

<Silicone fine particles 6>
Attach a stirrer, thermometer, reflux tube, and dropping funnel to a 2 L four-necked round bottom flask. The mixture was heated at an oil bath while stirring at 300 rpm. When the internal temperature reached 50 ° C., 200 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 30 minutes. Stirring was continued for 60 minutes at the same temperature, then about 5 g of acetic acid (special grade reagent) was added, mixed with stirring, and then filtered. The product particles on the filter were added with 600 mL of water twice and 200 mL of methanol once, followed by filtration and washing. The cake on the filter was taken out, crushed, and freeze-dried for 10 hours to obtain 40 g of white powder. The obtained particles were monodisperse spherical fine particles as observed by SEM. As a result of measuring the refractive index of this fine particle by the immersion method, it was 1.54. As a result of observing the particles with a cross-sectional TEM, it was confirmed that the particles had a single structure.

<Silicone fine particles 7>
Attach a stirrer, thermometer, reflux tube, and dropping funnel to a 2 L four-necked round bottom flask. The mixture was heated at an oil bath while stirring at 300 rpm. When the internal temperature reached 50 ° C., 200 g of a mixture of methyltrimethoxysilane and phenyltrimethoxysilane (23/77 mol%) was dropped from the dropping funnel over 30 minutes. Stirring was continued for 60 minutes at the same temperature, then about 5 g of acetic acid (special grade reagent) was added, mixed with stirring, and then filtered. The product particles on the filter were added with 600 mL of water twice and 200 mL of methanol once, followed by filtration and washing. The cake on the filter was taken out, crushed, and freeze-dried for 10 hours to obtain 40 g of white powder. The obtained particles were monodisperse spherical fine particles as observed by SEM. As a result of measuring the refractive index of this fine particle by the immersion method, it was 1.54. As a result of observing the particles with a cross-sectional TEM, it was confirmed that the particles had a single structure.

Example 1
Using a polyethylene container with a capacity of 300 ml, 47% by weight of silicone resin “OE-6630A / B” (manufactured by Dow Corning Toray) and “NYAG-02” (manufactured by Intematix, Inc .: Ce-doped YAG system) Phosphor, specific gravity: 4.8 g / cm ³ , D50: 7 μm) were mixed at a ratio of 53 wt%.

  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 silicone resin liquid for sheet preparation. Using a slit die coater, a phosphor-dispersed silicone resin for sheet preparation is applied as a base film onto “Therapyle” HP2 (manufactured by Toray Film Processing Co., Ltd.), heated at 120 ° C. for 1 hour, dried, and 100 mm square fluorescent A body sheet was obtained. At this time, the ejection performance was evaluated, but the resin was ejected from the die simultaneously with the start of ejection, and good ejection performance was confirmed.

  After that, as a protective film, “Masking Tape” NO. 609 (# 25) (manufactured by Teraoka Seisakusho) was installed with a laminator (manufactured by Taisei Laminator) to prepare a phosphor sheet laminate. As a result of measuring the adhesive strength, the adhesive strength A was 0.015 N / cm, and the adhesive strength B was 0.80 N / cm.

The obtained phosphor sheet laminate was cut into a 40 mm square to produce a pasted sample, and then pastability was evaluated. The results are shown in Table 1. As a result of confirming the pasted phosphor sheet,
No cracks or peeling marks were generated on the adhered phosphor sheet, and very good results were obtained.

  Further, a hole having a diameter of 200 μm was punched out from the cover film side using a die punching device (manufactured by UHT) in the remaining phosphor sheet laminate. As a result of evaluating the workability by visually observing 100 punched holes, the number of cracks and chips was 25, and a practically satisfactory result was obtained. The phosphor sheet with holes was cut into 1 mm square pieces with a cutting device (GCUT manufactured by UHT). The phosphor sheet cut to 1 mm square was arranged so that the phosphor sheet surface was in contact with the chip surface of the substrate on which the blue LED chip was mounted. Using a die bonding apparatus (manufactured by Toray Engineering), the holes of the phosphor sheet and the surface electrode of the LED chip were aligned and pressed from the base film side with a heating head at 100 ° C. for 10 seconds to be bonded. After returning the sample pressure-bonded for 10 seconds to room temperature and then peeling off the base film, the phosphor sheet is completely affixed on the blue LED, and the phosphor sheet can be removed cleanly without any phosphor sheet remaining on the substrate. did it. When the surface electrode of the LED chip was wire-bonded, it could be bonded without problems through the holes that had been previously processed into the phosphor sheet. 10 LED packages in which the same LED with a phosphor sheet is sealed with a transparent resin are manufactured, connected to a DC power source and turned on, and the correlated color temperature (CCT) of all 10 samples is measured with a color illuminometer (Konica Minolta CL200A). ) Was measured, and the difference between the maximum value and the minimum value was evaluated as the color temperature variation. Table 1 shows the results.

  In addition, as a result of performing the light resistance test described above, the luminance retention rate (%) was 88%, and a result having no practical problem was obtained.

Similarly, cut the LED element with a phosphor sheet and measured the cross-section SEM, and the film of the midpoint of the line point connecting the center point of the LED element light emitting surface and the light emitting surface end for 10 samples. The difference in thickness is measured, the difference in film thickness between the two points is obtained, and the ratio of the difference in film thickness to the film thickness at the central point is defined as the difference in film thickness (%) of the sample. Calculated. The variation is shown in Table 1. Negative values indicate that the film thickness at the midpoint is greater than the film thickness at the center point (Examples 2 to 18) -Adhesive strength effect-
Except having changed into the protective film and base film of Tables 1-2, the fluorescent substance sheet laminated body was produced by operation similar to Example 1, and evaluated. The results are shown in Tables 1-2. From these examples, it was found that both good adhesiveness and good workability can be achieved within the range of the adhesive strength of the present invention.

(Examples 19 to 22) -Effect of phosphor content-
Except having changed into content of the fluorescent substance of Table 3, the fluorescent substance sheet laminated body was produced by operation similar to Example 8, and evaluated. The results are shown in Table 3. It has been found that even when the phosphor content in the phosphor sheet is high, both good adhesion and good workability can be achieved within the range of the adhesive strength of the present invention. Moreover, the higher the phosphor content, the better the light resistance. From these examples, it was found that the light resistance of the sheet was excellent when the phosphor content was 53% by weight or more of the entire sheet.

Example 23 Effect of Silicone Fine Particles
Using a polyethylene container having a capacity of 300 ml, 36% by weight of silicone resin “OE-6630A / B” (manufactured by Dow Corning Toray) and “NYAG-02” (manufactured by Intematix: Ce-doped YAG system) as a phosphor Phosphor, specific gravity: 4.8 g / cm ³ , D50: 7 μm) were mixed at a ratio of 60.0 wt% and silicone fine particles 1 were mixed at a ratio of 4.0 wt%. Except for the change, a phosphor sheet laminate was produced and evaluated in the same manner as in Example 1. The results are shown in Table 4. It has been found that even when the silicone fine particles are contained, both good adhesion and good processability can be achieved within the range of the adhesive strength of the present invention. In addition, stable discharge characteristics of the slit die were obtained, the film thickness was excellent, and there was obtained a result that there was little variation with respect to the color temperature when emitting light by mounting on a blue LED. The cross-sectional SEM of the obtained phosphor sheet was observed, and the average particle size (D50) of the phosphor and the silicone fine particles was determined from the obtained image. The average particle size of the silicone fine particles was 0.1 μm.

(Examples 24-29)-Effect of silicone fine particles, types of silicone fine particles-
As in Example 23, the compounding ratio of the silicone resin, the phosphor and the silicone fine particles was changed as shown in Table 4 to produce a phosphor sheet laminate in the same procedure as in Example 23. The results are shown in Table 4. As in Example 23, good results were obtained for both samples in terms of both pastability and workability. Moreover, it was a favorable result also about the characteristic other than that. It has been found that when the average particle size of the silicone fine particles is 0.05 μm, the effect of improving the discharge property is reduced.

(Example 30)-Effect of silicone fine particles, adhesive strength-
Using a polyethylene container with a capacity of 300 ml, 43% by weight of silicone resin “OE-6630A / B” (manufactured by Dow Corning Toray) and “NYAG-02” (manufactured by Intematix: Ce-doped YAG system) as a phosphor Phosphor, specific gravity: 4.8 g / cm ³ , D50: 7 μm) was mixed at a ratio of 53.0 wt% and silicone fine particles 2 at a ratio of 4.0 wt%. Except for the change, a phosphor sheet laminate was produced and evaluated in the same manner as in Example 1. The results are shown in Table 5. It has been found that even when the silicone fine particles are contained, both good adhesion and good processability can be achieved within the range of the adhesive strength of the present invention. In addition, stable discharge characteristics of the slit die were obtained, the film thickness was excellent, and there was obtained a result that there was little variation with respect to the color temperature when emitting light by mounting on a blue LED. When the cross-sectional SEM of the obtained phosphor sheet was observed and the average particle size (D50) of the phosphor and the silicone fine particles was determined from the obtained image, the average particle size of the silicone fine particles was 0.5 μm.

(Examples 31-47)-Effect of silicone fine particles, effect of adhesive strength-
Except having changed into the protective film and base film of Tables 5-6, the fluorescent substance sheet laminated body was produced by operation similar to Example 30, and evaluated. The results are shown in Tables 5-6. From these examples, it was found that even when silicone fine particles were contained, both good adhesiveness and good workability could be achieved within the range of the adhesive strength of the present invention. In addition, stable discharge characteristics of the slit die were obtained, the film thickness was excellent, and there was obtained a result that there was little variation with respect to the color temperature when emitting light by mounting on a blue LED.

(Examples 48 to 50) -Effect of silicone fine particles, effect of phosphor content-
Table 7 shows the results of producing and evaluating a phosphor sheet laminate in the same manner as in Example 37, except that the phosphor content shown in Table 7 was changed. It has been found that even when the silicone fine particles are contained and the phosphor content in the phosphor sheet is high, both good adhesion and good processability can be achieved within the range of the adhesive strength of the present invention. Moreover, there was no problem in the discharge property of the slit die, and the higher the phosphor content, the better the light resistance. From these examples, it was found that the light resistance of the sheet was excellent when the phosphor content was 53% by weight or more of the entire sheet.

(Comparative Example 1)
Except that “Lumirror” H10 (manufactured by Toray Industries, Inc.) was used as the base film and “Masking tape” NO.603 (# 25) (manufactured by Teraoka Seisakusho) was used as the protective film, fluorescence was obtained in the same manner as in Example 1. A body sheet laminate was prepared. As a result of measuring the adhesive strength, the adhesive strength A was 0.010 N / cm, and the adhesive strength B was 2.50 N / cm. The evaluation results are shown in Table 8.

  As a result of the evaluation of sticking property, the sticking phosphor sheet was cracked and peeled off, and the sticking property was poor. Moreover, as a result of evaluating workability, the number of cracks and chips was 60, and a result of poor workability was obtained. When the sheet that was actually singulated was pasted on the blue LED element in the same manner as in Example 1, the base film could not be peeled off well, so it could not be easily pasted on the LED element. There was also. Using the pasted LED element, the film thickness difference (%), color temperature variation, and light resistance were evaluated. The results are shown in Table 8.

(Comparative Example 2)
Except having changed into the protective film and base film of Table 8, the fluorescent substance sheet laminated body was produced by operation similar to Example 1, and evaluated. The results are shown in Table 8. The pasting property was good, but the workability was insufficient.

(Comparative Examples 3-5)
Except having changed into the protective film and base film of Table 8, the fluorescent substance sheet laminated body was produced by operation similar to Example 1, and evaluated. The results are shown in Table 8. Although the pasting property was good, when the protective film was peeled off after processing, the phosphor sheet was cracked due to the strong adhesion between the protective film and the phosphor sheet.

(Comparative Examples 6 and 7)
Except having changed into the protective film and base film of Table 8, the fluorescent substance sheet laminated body was produced by operation similar to Example 1, and evaluated. The results are shown in Table 8. Although the processability was good, the phosphor sheet was easily peeled off from the base film when the sample was handled, and the phosphor sheet was cracked.

(Comparative Examples 8 and 9)
Except having changed into the protective film and base film of Table 8, the fluorescent substance sheet laminated body was produced by operation similar to Example 1, and evaluated. The results are shown in Table 8. The workability was good, but the pastability was insufficient.

DESCRIPTION OF SYMBOLS 1 Phosphor sheet 2 LED chip 3 Electrode 4 Circuit board 5 Metal wire

Claims (8)

A phosphor sheet laminate in which a protective film, a phosphor sheet, and a base film are laminated, and the adhesive strength (A) between the protective film and the phosphor sheet at room temperature and the base film at room temperature Adhesive strength (B) between the phosphor sheets is A = 0.015 N / cm or more and 0.05 N / cm or less B = 0.6 N / cm or more and 2.0 N / cm or less Laminated body. The adhesive strengths (A) and (B) are
The phosphor sheet laminate according to claim 1, wherein A = 0.02 N / cm or more and 0.03 N / cm or less B = 0.6 N / cm or more and 1.2 N / cm or less. The phosphor sheet laminate according to claim 1 or 2, wherein the phosphor sheet contains a silicone resin. The phosphor sheet laminate according to any one of claims 1 to 3, wherein the phosphor content in the phosphor sheet is 53 wt% or more of the entire sheet. The phosphor sheet laminate according to any one of claims 1 to 3, wherein the phosphor content in the phosphor sheet is 57 wt% or more of the entire sheet. The phosphor sheet laminate according to any one of claims 1 to 3, wherein the phosphor content in the phosphor sheet is 60% by weight or more of the entire sheet. The phosphor sheet laminate according to any one of claims 1 to 6, wherein the phosphor sheet contains silicone fine particles. The phosphor sheet laminate according to claim 7, wherein an average particle size of the silicone fine particles is 0.1 μm or more and 2 μm or less.

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