WO2017057454A1

WO2017057454A1 - Method for manufacturing light-emitting device, and method for manufacturing display device

Info

Publication number: WO2017057454A1
Application number: PCT/JP2016/078612
Authority: WO
Inventors: 神崎達也; 重田和樹
Original assignee: 東レ株式会社
Priority date: 2015-09-30
Filing date: 2016-09-28
Publication date: 2017-04-06
Also published as: TW201712902A; TWI693730B; JPWO2017057454A1

Abstract

The purpose of the present invention is to provide a method for manufacturing a light-emitting device, the manufacturing method including a step for dicing a phosphor layer of a phosphor sheet having a phosphor layer on a substrate film, a step for performing heat treatment or ultraviolet irradiation of the phosphor sheet in which the phosphor layer is diced, a step for picking up the diced phosphor layer, and a step for affixing the diced phosphor layer to an LED chip, wherein the method for manufacturing a light-emitting device is characterized in that the adhesion strength A between the phosphor layer and the substrate film at room temperature before the heat treatment or the ultraviolet irradiation and the adhesion strength B between the phosphor layer and the substrate film at room temperature after the heat treatment or the ultraviolet irradiation satisfy the expressions A = 5.0 N/cm or greater and B = 0.1 N/cm or less, respectively, the method for manufacturing a light-emitting device using a phosphor sheet having excellent cutting workability as well as excellent pick-up properties.

Description

Method for manufacturing light emitting device and method for manufacturing display device

The present invention relates to a method for manufacturing a light emitting device and a method for manufacturing a display device.

Light-emitting diodes (LEDs, Light Emitting Diodes) are used for backlights of liquid crystal displays (LCDs) and car headlights with low power consumption, long service life, and design characteristics 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 one of the specific methods for installing the phosphor on the LED chip, a method of using a phosphor sheet that is a sheet-like resin layer (phosphor layer) in which the phosphor material is uniformly distributed in advance has been proposed. . 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.

Generally, a phosphor sheet has a phosphor layer on a base film, and a protective film on the uppermost surface as necessary. One of the manufacturing methods in the case of manufacturing an LED light-emitting device using such a phosphor sheet is to separate the phosphor layer by cutting after removing the protective film, and chip the separated phosphor layer into chips. It is picked up by a mounter or the like and attached to the LED chip (for example, see Patent Document 1). In some cases, the phosphor sheet is perforated during the cutting process.

As another method, a plurality of LEDs are collectively embedded in a sheet-like phosphor layer (for example, see Patent Document 2). Further, in order to divide the LED chip into individual pieces, a method has been proposed in which the LED with the phosphor layer after being embedded in one piece is cut into individual pieces by dicing (see, for example, Patent Document 3).

JP 2009-235368 A JP 2010-123802 A JP 2014-130918 A

As described in Patent Document 1, in the method of preliminarily separating the phosphor sheet and then bonding it to the LED chip, the ease of individualization and its handling are important in terms of productivity. In this respect, when the adhesive strength between the phosphor layer and the substrate film is insufficient, there is a problem that the phosphor layer is peeled off and scattered from the substrate film during the cutting process. On the other hand, when the adhesive strength between the phosphor layer and the substrate film is too strong, there is a problem that when the separated phosphor layer is picked up, it cannot be picked up.

In addition, the phosphor sheets listed in

Patent Documents

2 and 3 have high flexibility of the phosphor layer because emphasis is placed on the LED chip embeddability, and the phosphor sheet can be separated into individual processes such as cutting and drilling. There was also a problem that the layer was deformed.

Thus, in improving productivity, it has been a challenge to achieve both cutting workability and pick-up performance.

In view of such circumstances, an object of the present invention is to provide a method for manufacturing a light emitting device using a phosphor sheet that is excellent in cutting processability and excellent in pick-up property. Moreover, it aims at improving the productivity of LED light-emitting device by it.

In the phosphor sheet having a phosphor layer on a substrate film, the present invention includes a step of dividing the phosphor layer into pieces, and heat-treating or irradiating the phosphor sheet with the phosphor layer separated into pieces. A manufacturing method including a step, a step of picking up the separated phosphor layer, and a step of attaching the separated phosphor layer to an LED chip, before the heat treatment or ultraviolet irradiation Bond strength A between the phosphor layer and the substrate film at room temperature, and bond strength B between the phosphor layer and the substrate film at room temperature after the heat treatment or ultraviolet irradiation,
A = 5.0 N / cm or more and B = 0.1 N / cm or less.

According to the production method of the present invention, the phosphor layer can be easily cut into individual pieces and the pickup property is excellent, so that the productivity of the light emitting device using the phosphor sheet can be increased.

Schematic sectional view showing an example of a phosphor sheet used in the method for manufacturing a light emitting device of the present invention Schematic sectional view showing an example of a phosphor sheet used in the method for manufacturing a light emitting device of the present invention Process drawing which shows one Embodiment of the method of manufacturing a light-emitting device by this invention. Process drawing which shows one Embodiment of the method of manufacturing a light-emitting device by this invention. Process drawing which shows one Embodiment of the method of manufacturing a light-emitting device by this invention.

In the phosphor sheet having a phosphor layer on a base film, the present invention includes a step of dividing the phosphor layer into pieces, and heat-treating or irradiating the phosphor sheet with the phosphor layer separated into pieces. A manufacturing method including a step, a step of picking up the separated phosphor layer, and a step of attaching the separated phosphor layer to an LED chip, before the heat treatment or ultraviolet irradiation The adhesive strength A between the phosphor layer and the substrate film at room temperature, and the adhesive strength B between the phosphor layer and the substrate film at room temperature after the heat treatment or ultraviolet irradiation,
A = 5.0 N / cm or more and B = 0.1 N / cm or less.

FIG. 1 is a schematic cross-sectional view showing an example of a phosphor sheet used in the method for manufacturing a light emitting device of the present invention. The phosphor sheet 6 is formed by forming a phosphor layer 2 containing the phosphor 1 on a base film 5 composed of an adhesive layer 3 and a film 4.

Another phosphor layer, diffusion layer, and transparency may be provided on the upper layer and / or lower layer of the phosphor layer.

The transparent layer is a layer that contains a resin having a total light transmittance of 90% or more at a wavelength of 450 nm and does not contain a phosphor. The transparent layer preferably has tackiness so that it can be attached to the LED chip without using an adhesive. Further, the refractive index is preferably 1.58 or more. When the transparent layer is attached to the surface of an LED chip such as GaN or sapphire having a high refractive index, it is possible to reduce the refractive index difference and improve light extraction. Therefore, it is preferable that the transparent layer is placed below the phosphor layer.

The diffusion layer is a layer containing a resin and a diffusion material such as silica, titania, zirconia. By setting the diffusion layer, the directivity of light emitted from the LED chip can be weakened, and more isotropic light can be extracted. Therefore, it is preferable that the diffusion layer is disposed on the phosphor layer.

FIG. 2 shows a phosphor sheet in which a diffusion layer 7 is formed in the upper layer of the phosphor layer 2 and a transparent layer 8 is formed in the lower layer.

<Method for manufacturing light emitting device>
The following description regarding the method for manufacturing the light emitting device is an example, and the present invention is not limited thereto.

The method for manufacturing a light emitting device of the present invention includes a step of separating the phosphor layer of the phosphor sheet, a step of performing heat treatment or ultraviolet irradiation on the separated phosphor sheet, and the above-mentioned individualization. A step of picking up the phosphor layer, and a step of attaching the singulated phosphor layer to the LED chip.

And the adhesive strength A between the phosphor layer and the substrate film at room temperature before the heat treatment or ultraviolet irradiation, and between the phosphor layer and the substrate film at room temperature after the heat treatment or ultraviolet irradiation. The adhesive strength B of
A = 5.0 N / cm or more and B = 0.1 N / cm or less. Due to this relationship, the cutting workability and the pick-up property are improved.

The adhesive strength A has a great influence on the cutting processability, and when it is less than 5.0 N / cm, the phosphor layer is easily peeled off from the base material film during the cutting process. The adhesive strength A is more preferably 10 N / cm or more in terms of cutting workability.

The adhesive strength B has a great influence on the pick-up property, and if it exceeds 0.1 N / cm, the phosphor layer is likely to be cracked or chipped when picked up as an individual phosphor layer. The adhesive strength B is more preferably 0.05 N / cm or less in terms of pickup properties.

The heat treatment conditions for reducing the adhesive strength are preferably a treatment temperature of 60 ° C. to 200 ° C., more preferably 80 ° C. to 160 ° C. The treatment time is preferably 5 minutes or more, more preferably 10 minutes or more. Moreover, the ultraviolet irradiation conditions for reducing the adhesive strength are at least 100 mJ / cm ² exposure in terms of i-line, and more preferably 150 mJ / cm ² or more.

In particular, in the case of heat treatment, the adhesive strength B after being treated at 90 ° C. for 20 minutes is preferably within the above range. In the case of ultraviolet irradiation, the adhesive strength B after exposure of 200 mJ / cm ^{2 in} terms of i-line is performed. Is preferably in the above range.

The adhesive strength in the present invention means strength measured by a method according to JIS C6471 (1995) copper foil peel strength test method A for measuring the peel strength of a copper foil. When measuring the adhesive strength between the phosphor layer and the substrate film, the peel strength of the substrate film from the phosphor layer is measured.

Specifically, digital force gauge “FGN-5B” (manufactured by Nidec Symposium), electric vertical force gauge test stand “FGS-50-VB-L (H)” (manufactured by Nidec Symposium), 90 degree peeling jig “FGTT-12” (manufactured by Nidec Sympo) is used as a measuring device, and double-sided tape “NW-R15” (manufactured by Nichiban) is used to fix the sample. Measure the adhesive strength between body layers.

To adjust the adhesive strength, first, the tackiness of the phosphor layer is important. The adhesiveness of the phosphor layer is determined by the type of resin used, the type of phosphor, the content of the phosphor, and the drying conditions at the time of preparing the phosphor layer. Therefore, when adjusting the adhesive strength, it is necessary to select a substrate film suitable for the tackiness of the phosphor layer.

FIG. 3 shows an embodiment of a method for manufacturing a light emitting device.

(Step of dividing the phosphor layer into individual pieces)
FIGS. 3A and 3B show a process of dividing the phosphor layer into individual pieces. The method for cutting the phosphor layer 2 for singulation is not particularly limited, and methods such as punching with a mold, processing with a laser, and cutting with a blade are used.

At this time, the phosphor layer 2 remains attached to the base film 5. Since processing with a laser imparts high energy, resin burnt or phosphor deterioration may occur depending on the irradiation conditions. Cutting with a blade is more preferable because there is no such concern. FIG. 3A illustrates an example of cutting with the blade 9.

As the 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 layers 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 cutting is preferably performed by dry cutting. Dry cutting is a cutting method that does not use water or other liquid during cutting. Examples include cutting with a Thomson blade, but are not limited thereto. Dry cut is particularly effective when the phosphor layer includes a phosphor whose luminous efficiency is reduced by reacting with water, such as a KSF phosphor (for example, K ₂ SiF ₆ : Mn) described later.

The shape of the individual phosphor layers is not particularly limited, and examples thereof include polygons such as squares, rectangles, and hexagons, circles, and ellipses. Among these, a square and a rectangle are preferable.

It is preferable that at least one side of the singulated phosphor layer has a length of 0.1 mm or more. When cutting with a blade or a rotary blade, stress may be applied to the phosphor layer due to the thickness of the blade or the rotary blade itself, which may cause minute cracks. If the phosphor layer is to be separated into pieces with a size of less than 0.1 mm, a minute crack generated between adjacent dividing lines may be connected, and the phosphor layer may be broken. Such a problem occurs when the adhesive strength A is 5.0 N / cm or more, more preferably 10 N / cm or more, and the length of at least one side of the singulated phosphor layer is 0.1 mm or more. It is preferable because it can be cut without being generated.

In addition, it is preferable that at least one side of the singulated phosphor layer has a length of 3 mm or less, and more preferably 0.3 mm or less. In the process of picking up the phosphor layer separated from the base film, a suction jig such as a collet is used. At this time, a part of the separated phosphor layer is peeled off from the base film. There is a moment when the part adheres to the base film. At this moment, stress is applied to the phosphor layer. This stress is proportional to the size of the separated phosphor layer, and the larger the size of the separated phosphor, the easier the phosphor layer breaks. The adhesive strength B is 0.1 N / cm or less, more preferably 0.05 N / cm or less, and the length of at least one side of the singulated phosphor layer is 3 mm or less, more preferably 0.3 mm or less. If it exists, since it becomes possible to pick up without causing such a problem, it is preferable.

The phosphor layer may be perforated before or after the individualization step or simultaneously with the individualization. Although known methods such as laser processing and die punching can be suitably used for drilling, laser processing may cause burning of the resin and deterioration of the phosphor depending on the irradiation conditions, so there is no such concern. Punching with a mold is more preferable.

When performing the punching process, the punching process is impossible after the phosphor layer is attached to the LED chip. Therefore, it is essential to perform the punching process before applying the punching process. At this time, the phosphor layer remains adhered to the base film. In the punching process using a mold, a hole having an arbitrary shape or size can be formed depending on the electrode shape of the LED chip to be attached.

Any size and shape of the hole can be formed by designing the mold. In order to avoid reducing the area of the light emitting surface, the electrode joint portion on the LED chip inside and outside the 1 mm square is preferably, for example, 200 μm or less in diameter when the electrode joint portion is circular. In total, the diameter is preferably 200 μm or less. In addition, an electrode for wire bonding or the like needs to have a certain size. For example, when the electrode portion is circular, at least its diameter is about 50 μm, so the hole size is about 50 μm accordingly. It is preferable that

If the size of the hole is too large compared to the electrode, the light emitting surface is exposed, light leakage occurs, and the color characteristics of the LED light emitting device may deteriorate. Moreover, when too small than an electrode, a wire may touch at the time of wire bonding, and it may cause a joining defect. Therefore, it is preferable to process a small hole of 50 μm or more and 200 μm or less with high accuracy within ± 10% for pattern processing.

Since both processes are performed while the phosphor layer is attached to the base film, it tends to be a problem that the phosphor layer is peeled off from the film during processing. It can be said that the processability is good when the phosphor layer is not peeled off from the base material film during the processing as described above, and the processed portion is not cracked or chipped.

Hereinafter, the phosphor sheet in a state in which the separated phosphor layer is stuck on the base film may be referred to as “divided sheet”.

(The process of heat-treating or irradiating the phosphor sheet with the phosphor layer separated into individual pieces)
FIG. 3C shows a step of performing heat treatment or ultraviolet irradiation on the phosphor sheet in which the phosphor layer is singulated, that is, the singulated sheet 10. In the manufacturing method of the light emitting device of the present invention, the adhesive strength between the phosphor layer and the base film is lowered by heat treatment or ultraviolet irradiation, and this step reduces the adhesive strength between the phosphor layer and the base film. Can be made. When ultraviolet irradiation is performed, irradiation may be performed from any direction, but it is more effective to irradiate ultraviolet rays from the base film side. The preferable conditions for heat treatment or ultraviolet irradiation are as described above.

(Step of picking up individual phosphor layers)
FIG. 3D shows a process of picking up the individual phosphor layers. In this step, the phosphor layer is picked up using a pickup device equipped with a suction device such as a collet. FIG. 3D illustrates a collet 11 as a pickup device.

In the present invention, since the adhesive force between the phosphor layer and the substrate film can be changed, the phosphor layer is separated into pieces on the substrate film, and the separated phosphor layer is picked up to the LED chip. The pasting process can be easily performed. It can be said that the pick-up property is good when the separated phosphor layer is easily peeled off from the base film and the phosphor layer is not cracked or chipped.

Among them, as a suction device, a porous structure having an opening area ratio of 30% or more and 60% or less on the surface on which the singulated sheet 10 is adsorbed and held, a holding body made of an elastic body that holds the porous structure, and the holding It is preferable to use a collet that is inside the body and includes a suction path for sucking the phosphor sheet through the porous structure.

The porous structure preferably has a mesh-like opening. For example, a stainless steel wire having a wire diameter of 15 μm is crossed in two orthogonal directions to form a woven fabric to form a 30 μm square opening. Thereby, it is possible to pick up even when the phosphor layer is separated into pieces of 0.5 mm square or less.

(Step of attaching the separated phosphor layer to the LED chip)
FIG. 3E shows a step of attaching the individual phosphor layers to the LED chip 12. The collet 11 picked up from the separated phosphor layer is transported and attached to the light extraction surface which is the surface opposite to the electrode forming surface of the LED chip 12.

Adhesive (not shown) is preferably used for pasting, and known die-bonding 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 can be used. If the phosphor layer has adhesiveness, it may be used.

In addition, a method of heating and attaching the phosphor layer is also preferable. In the case of a semi-cured phosphor sheet, it is preferable to use curing by heating. The heating condition is preferably 1 minute to 1 hour at a temperature of 100 ° C. to 200 ° C., more preferably 5 minutes to 30 minutes at a temperature of 120 ° C. to 150 ° C.

Also, when the phosphor layer has heat softening properties after curing, it can be adhered by heat fusion.

Also, if the step of heating the phosphor layer and attaching it to the LED chip is performed in the air, bubbles may be caught between the LED chip and the phosphor sheet. When bubbles are bitten, light is diffusely reflected at the interface between the bubble-LED chip and the bubble-phosphor layer, resulting in a decrease in light extraction efficiency from the LED chip, resulting in a decrease in luminance of the manufactured light-emitting device. End up.

From the viewpoint of preventing such bubble entrapment, it is preferable to perform the step of heating and attaching the phosphor layer in a vacuum atmosphere. The vacuum atmosphere is preferably 10 hPa or less, more preferably 5 hPa or less, and particularly preferably 1 hPa or less. As heating conditions, a temperature of 40 ° C. to 200 ° C. is preferably 1 second to 5 minutes, a temperature of 60 ° C. to 180 ° C. is more preferably 2 seconds to 3 minutes, and a temperature of 80 ° C. to 120 ° C. 10 seconds or more and 1 minute or less are particularly preferable.

(Subsequent steps)
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 layer 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 layer 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.

When the phosphor layer 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. The case where the phosphor layer is stuck to the LED chip in a cured state includes, for example, a case where an adhesive layer is separately provided on the cured phosphor layer, and a case where the phosphor layer has heat-fusibility after curing. is there. The phosphor layer may also serve as a sealant for the LED chip. However, as shown in FIG. 3 (f), the LED chip to which the phosphor layer is attached is further coated with a known silicone resin or the like. 15 can be used for sealing. Moreover, after sealing an LED chip with a translucent sealing material, it is also possible to use a phosphor layer on the sealing material.

In addition, when applied to a face-up type LED chip, the phosphor layer is separated into pieces in the same manner as described above and then attached to the light extraction surface of the LED chip. When the phosphor layer is in a semi-cured state, the phosphor layer 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 layer 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 layer 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. .

(Another embodiment)
FIG. 4 shows another embodiment of the method for manufacturing a light emitting device of the present invention. The process up to the process shown in FIG. 4B is the same as the process shown in FIG. In the present embodiment, thereafter, as shown in FIG. 4B-2, a step of stretching the base film is included. A gap can be formed between the separated phosphor layers by stretching the base film. By creating a gap in this way, when picking up only a single phosphor layer, it can be performed more easily.

At this time, if the stretching is performed radially, the gaps are formed in a grid pattern. Fig.5 (a) is an example of the top view which shows the fluorescent substance sheet 6 after cut | disconnecting the fluorescent substance layer 2, as seen in FIG.3 (b) and FIG.4 (b). The phosphor layer 2 is separated into rectangles by a dividing line 16. Moreover, FIG.5 (b) is a fluorescent substance sheet after extending | stretching the base film of the fluorescent substance sheet shown to Fig.5 (a) to the vertical direction and a horizontal direction. The large gap 17 between the phosphor layers as shown in FIG. 5B is more preferable because only the target phosphor layer can be reliably picked up.

It is preferable that the gap is large for easy pickup. For this purpose, the degree of stretching of the substrate is preferably 0.5 or more, more preferably 1 or more, further preferably 1.5 or more, and particularly preferably 2 or more. The degree of stretching here is a value calculated by the following formula.

As another modification, an individual phosphor layer may be attached to an LED chip mounted on a substrate.

(Phosphor sheet)
The phosphor sheet used in the present invention is a sheet-like material having a phosphor layer on a substrate film.

(Phosphor layer)
In the present invention, the phosphor layer refers to a layer mainly containing a phosphor and a resin. Components such as a dispersant, a crosslinking agent, a photopolymerization initiator, a thermal polymerization initiator, a leveling agent, a thixotropy adjusting agent, and a plasticizer may be included as necessary.

The phosphor layer preferably has a storage elastic modulus at 25 ° C. of 0.1 MPa or more. Thereby, cutting processes, such as individualization, can be performed easily. More preferably, it is 1 MPa or more, More preferably, it is 10 MPa or more, Especially preferably, it is 100 Mpa or more. When the pressure is less than 0.1 MPa, the flexibility of the phosphor layer is too high, and a flow or the like is generated at the time of cutting, so that stable cutting cannot be performed.
Further, from the viewpoint of preventing the phosphor layer from being cracked during the cutting process, the storage elastic modulus at 25 ° C. is preferably 2000 MPa or less, and more preferably 1000 MPa or less.

Here, the storage elastic modulus is a storage elastic modulus obtained by dynamic viscoelasticity measurement. Dynamic viscoelasticity means that when shear strain is applied to a material at a sinusoidal frequency, the shear stress that appears when a steady state is reached is divided into a component (elastic component) whose strain and phase match, and the strain and phase are This is a technique for analyzing the dynamic mechanical properties 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.

(resin)
The resin contained in the phosphor layer may be any resin as long as the phosphor can be uniformly dispersed therein and can form the phosphor layer.

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.

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.

Moreover, it is also possible to use a silicone sealing material for general LED applications as a commercially available product. 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.

The silicone resin preferably has heat-fusibility. This is because when the phosphor layer has heat-fusibility, the phosphor layer can be heated and attached to the LED chip. The heat fusibility mentioned here is the property of softening by heating, and when the phosphor sheet has heat fusibility, it is not necessary to use an adhesive for attaching to the LED chip, thus simplifying the process. Can be The phosphor layer having heat-fusibility is a phosphor sheet having a storage elastic modulus at 25 ° C. of 0.1 MPa or more and a storage elastic modulus at 100 ° C. of less than 0.1 MPa.

As an example of the silicone resin having heat-fusibility, a cross-linked product obtained by hydrosilylation reaction of a cross-linkable silicone composition including the compositions (A) to (D) is particularly preferable. This crosslinked product can be preferably used as a matrix resin for a phosphor sheet that does not require an adhesive because the storage elastic modulus decreases at 60 ° C. to 250 ° C. and a high adhesive force is obtained by heating.
(A) Average unit formula:
(R ¹ ₂ SiO _2/2 ) _a (R ¹ SiO _3/2 ) _b (R ² O _1/2 ) _c
(Wherein R ¹ is a phenyl group, an alkyl or cycloalkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, provided that 65 to 75 mol% of R ¹ is phenyl. 10 to 20 mol% of R ¹ is an alkenyl group, R ² is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and a, b, and c are 0.5 ≦ a ≦ 0. (6, 0.4 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.1, and a + b = 1)
An organopolysiloxane represented by
(B) General formula:
R ³ ₃ SiO (R ³ ₂ SiO) _m SiR ³ ₃
(Wherein R ³ is a phenyl group, an alkyl or cycloalkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, provided that 40 to 70 mol% of R ³ is phenyl. And at least one of R ³ is an alkenyl group, and m is an integer of 5 to 50.) {5 to 15 parts by weight relative to 100 parts by weight of component (A)}
(C) General formula:
(HR ⁴ ₂ SiO) ₂ SiR ⁴ ₂
(In the formula, R ⁴ is a phenyl group, or an alkyl group or cycloalkyl group having 1 to 6 carbon atoms, provided that 30 to 70 mol% of R ⁴ is phenyl.)
{Amount such that the molar ratio of silicon-bonded hydrogen atoms in this component to the total of alkenyl groups in component (A) and component (B) is 0.5 to 2}, and ( D) Catalyst for hydrosilylation reaction {Amount sufficient to promote hydrosilylation reaction between alkenyl group in component (A), component (B) and silicon atom-bonded hydrogen atom in component (C)}.

In the general formula of component (A), the values of a, b, and c are sufficient to obtain sufficient hardness at room temperature of the resulting crosslinked product, and softening at high temperature. In the general formula of the component (B), if the content of the phenyl group is less than the lower limit of the above range, the resulting crosslinked product is insufficiently softened at a high temperature. The resulting crosslinked product loses its transparency, and its mechanical strength also decreases. In the formula, at least one R ³ is an alkenyl group. This is because if the alkenyl group is not present, this component is not taken into the crosslinking reaction, and this component may bleed out from the resulting crosslinked product. In the formula, m is an integer in the range of 5 to 50, and this is a range in which handling workability is maintained while maintaining the mechanical strength of the resulting crosslinked product.

The content of the component (B) is within a range of 5 to 15 parts by weight with respect to 100 parts by weight of the component (A), and is a range for obtaining sufficient softening at a high temperature of the resulting crosslinked product. .

In the general formula of the component (C), R ⁴ is a phenyl group, or an alkyl group or cycloalkyl group having 1 to 6 carbon atoms. Examples of the alkyl group for R ⁴ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a heptyl group. Examples of the cycloalkyl group for R ⁴ include a cyclopentyl group and a cycloheptyl group. Of R ⁴ , the phenyl group content is in the range of 30 to 70 mol%. This is a range in which the obtained crosslinked product can be sufficiently softened at a high temperature and can maintain transparency and mechanical strength.

The content of component (C) is such that the molar ratio of silicon-bonded hydrogen atoms in this component to the total of alkenyl groups in component (A) and component (B) is in the range of 0.5 to 2. This is a range in which sufficient hardness at room temperature of the resulting crosslinked product can be obtained.

The component (D) is a hydrosilylation catalyst for promoting the hydrosilylation reaction between the alkenyl group in the components (A) and (B) and the silicon atom-bonded hydrogen atom in the component (C). Examples of the component (D) include platinum-based catalysts, rhodium-based catalysts, and palladium-based catalysts, and platinum-based catalysts are preferred because they can significantly accelerate the curing of the silicone composition. Examples of the platinum-based catalyst include platinum fine powder, chloroplatinic acid, alcohol solution of chloroplatinic acid, platinum-alkenylsiloxane complex, platinum-olefin complex, and platinum-carbonyl complex, particularly platinum-alkenylsiloxane complex. It is preferable. Examples of the alkenylsiloxane include 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, Examples thereof include alkenyl siloxanes in which part of the methyl groups of these alkenyl siloxanes are substituted with ethyl groups, phenyl groups, and the like, and alkenyl siloxanes in which the vinyl groups of these alkenyl siloxanes are substituted with allyl groups, hexenyl groups, and the like. In particular, 1,3-divinyl-1,1,3,3-toteramethyldisiloxane is preferred because the stability of the platinum-alkenylsiloxane complex is good. Further, since the stability of the platinum-alkenylsiloxane complex can be improved, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane and 1,3-diallyl-1,1 are added to this complex. , 3,3-tetramethyldisiloxane, 1,3-divinyl-1,3-dimethyl-1,3-diphenyldisiloxane, 1,3-divinyl-1,1,3,3-tetraphenyldisiloxane, It is preferable to add an alkenyl siloxane such as 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane or an organosiloxane oligomer such as a dimethylsiloxane oligomer. It is preferable.

The content of the component (D) is an amount sufficient to promote the hydrosilylation reaction between the alkenyl group in the components (A) and (B) and the silicon-bonded hydrogen atom in the component (C). Although not particularly limited, it is preferable that the amount of metal atoms in the present component is within a range of 0.01 to 500 ppm by mass unit with respect to the silicone composition, and more preferably 0.01 to 100 ppm. The amount is preferably in the range of 0.01 to 50 ppm, and particularly preferably in the range of 0.01 to 50 ppm. This is a range in which the obtained silicone composition is sufficiently crosslinked and does not cause problems such as coloring.

The silicone composition is composed of at least the above components (A) to (D), and other optional components include ethynylhexanol, 2-methyl-3-butyn-2-ol, and 3,5-dimethyl-1-hexyne. Alkyne alcohols such as 3-ol and 2-phenyl-3-butyn-2-ol; enyne compounds such as 3-methyl-3-penten-1-yne and 3,5-dimethyl-3-hexen-1-in 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetrahexenylcyclotetrasiloxane; Further, a reaction inhibitor such as benzotriazole may be contained. The content of the reaction inhibitor is not limited, but is preferably in the range of 1 to 5,000 ppm with respect to the weight of the silicone composition. By adjusting the content of the reaction inhibitor, the storage elastic modulus of the resulting cross-linked product can be adjusted.

(Phosphor)
The phosphor is not limited as long as it 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 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 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 or more of _{_{_{Ba) Ga 2 S 4: Eu}}} , S i 6 - Z a l Z O Z N 8 - Z: Eu (0 <Z <4.2) , and the like.

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 <x <0.5, 0 <y <0.5.) And the like can be used.

Examples of the phosphor that emits red light include Y ₂ O ₂ S: Eu, La ₂ O ₂ S: Eu, Y ₂ O ₃ : Eu, Gd ₂ O ₂ S: Eu, and K ₂ SiF ₆ : Mn. .

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-based phosphors such as Eu, Ca _x (Si, Al) ₁₂ (O, N) ₁₆ : Oxynitride-based phosphors such as Eu, and (Ba, Sr, Ca) Si ₂ O _₂ N _2: u _{_{_{phosphor, Ca 8 MgSi 4 O 16 Cl}}} 2: Eu _{_{_{phosphor, SrAl 2 O 4: Eu,}}} Sr 4 Al 14 O 25: Eu, S i 6 - Z A l Z O Z N 8 - Z: Sialon phosphors such as Eu (0 <Z <4.2), general formula A ₂ MF ₆ : Mn (where A is selected from the group consisting of Li, Na, K, Rb and Cs, and at least Na and And / or one or more alkali metals containing K, and M is one or more tetravalent elements selected from the group consisting of Si, Ti, Zr, Hf, Ge, and Sn. And phosphors (KSF phosphors) such as fluoride compounds.

Of these, YAG-based phosphors, TAG-based phosphors, and silicate-based phosphors are preferably used in terms of luminous efficiency and luminance. Further, β-type sialon phosphors and Mn-activated double fluoride phosphors (so-called KSF phosphors) are preferable in terms of a wide chromaticity range. The KSF phosphor is particularly preferable because it has a low hardness and is less likely to generate burrs on the cut surface of the phosphor sheet as compared with a phosphor such as a β-type sialon phosphor.

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.

In the present invention, the average particle diameter means the median diameter, that is, D50. The D50 of the phosphor contained in the phosphor layer is obtained by subjecting a measurement image obtained by scanning electron microscope (SEM) of the cross section of the phosphor layer to image processing to obtain a particle size distribution, and in the volume-based particle size distribution obtained therefrom, Measurement is made by a method in which the particle diameter of 50% of the accumulated amount from the diameter side is the median diameter D50. When the particles are spherical, the particle diameter is taken as the particle size. When the particles are not spherical, the average value of the longest diameter and the shortest diameter is taken as the particle size. 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, the proportion of the phosphor in the total solid content in the phosphor layer is 40% by weight or more. It is preferably 50% by weight or more, more preferably 60% by weight or more, and particularly preferably 65% by weight or more. Although the upper limit of the phosphor content is not particularly defined, it is preferably 95% by weight or less, preferably 90% by weight or less of the entire phosphor layer from the viewpoint that a phosphor layer 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 content in the phosphor layer in the present invention can also be obtained from a prepared phosphor layer or an LED light emitting device equipped with the phosphor layer. For example, by embedding the phosphor layer 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 phosphor layer.

When the specific gravity of the resin and the phosphor forming the phosphor layer is clear, the weight ratio of the phosphor to the phosphor layer 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 layer 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 layer, disassemble the LED light-emitting device, take out the phosphor layer portion, and observe the cross-section by the same method to determine the weight ratio of the phosphor in the phosphor layer. Can be sought. By such a method, even when the preparation ratio at the time of preparing the phosphor layer is not clear, the prepared phosphor layer and the LED light-emitting device on which the phosphor layer is mounted by the above-described method and other known analysis methods can be used. It is possible to confirm the phosphor weight ratio in the layer.

(Silicone fine particles)
The phosphor layer preferably contains silicone fine particles. By containing the silicone fine particles, it is possible to obtain a phosphor layer having not only adhesiveness and workability but also good film thickness uniformity.

The silicone fine particles contained in the phosphor layer are preferably fine particles made of 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 Examples include -butyltributoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, and phenyltrimethoxysilane.

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 the method reported in JP-A-63-77940, the method reported in JP-A-6-248081, and in JP-A-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 is carried out in the production of 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, the particles are less likely to aggregate.

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, Pulrich refractometer, immersion type refractometer, immersion method, minimum declination method and the like are used as the total reflection method, but for measuring the refractive index of the silicone composition, The immersion method is useful for measuring the refractive index of the Abbe refractometer and the silicone 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 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. By using such silicone fine particles, it is possible to obtain a phosphor layer having excellent ejection properties and excellent film thickness uniformity when a slit die coater is used. 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 layer 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 volume-based 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. When the particles are spherical, the particle diameter is taken as the particle size. When the particles are not spherical, the average value of the longest diameter and the shortest diameter is taken as the particle size.

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 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.

(Other ingredients)
As other components, it is preferable to blend a hydrosilylation reaction retarder such as acetylene alcohol in the phosphor layer 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 surface smoothness of the phosphor layer, it is preferable to contain a low molecular weight polydimethylsiloxane component, silicone oil, and the like. The content of such components is preferably 100 to 2,000 ppm, more preferably 500 to 1,000 ppm, based on the entire composition.

(Base film)
The base film used in the present invention includes an adhesive strength A between the phosphor layer and the base film at room temperature before heat treatment or ultraviolet irradiation, and the phosphor at room temperature after heat treatment or ultraviolet irradiation. The adhesive strength B between the layer and the substrate film is such that A = 5.0 N / cm or more and B = 0.1 N / cm or less.

In the present invention, it is necessary that the adhesive strength between the base film and the phosphor layer is lowered by heat treatment or ultraviolet irradiation. As a method for realizing such characteristics, there is a method using a known film having a pressure-sensitive adhesive layer formed on the surface of a base film. Here, the pressure-sensitive adhesive layer needs to have a reduced adhesive strength by heat treatment or ultraviolet irradiation.

Since a phosphor layer is formed on such a base film, it is constant in order to suppress peeling of the phosphor layer from the base film during cutting such as individualization by cutting or dicing. The adhesive strength of can be kept. On the other hand, in the subsequent phosphor sheet pick-up step, the pick-up can be facilitated by reducing the adhesive strength by heat treatment or ultraviolet irradiation in advance.

The material is not particularly limited as long as it is a base film having such characteristics, and a known film having a pressure-sensitive adhesive layer formed on the surface, coated paper, or the like can be used. Specific examples of the film and coated paper include 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.), plastic-coated paper, aluminum (including aluminum alloys), zinc, copper, iron or other known metal laminated or vapor-deposited paper, or such known For example, a plastic film laminated or vapor-deposited can be used.

Among these, PET film, polyolefin film, polyvinyl chloride film and the like are preferable in terms of economy and handling. Furthermore, a film containing no plasticizer is particularly suitable from the viewpoint of storage stability. For example, when the film contains a low molecular weight plasticizer of phthalic acid diester type as a plasticizer, there is a problem that the phosphor layer softens because the plasticizer penetrates into the phosphor layer. . Moreover, when high temperature is required for hardening of resin, a polyimide film is preferable in terms of heat resistance.

The tensile elastic modulus of the base film is preferably 0.1 MPa or more, and more preferably 1 MPa or more. Moreover, it is preferable that the tensile elasticity modulus of a base film is 100 Mpa or less, and it is more preferable that it is 10 Mpa or less. By being in the said range, a base film can be extended | stretched easily. As shown in FIG. 4B-2, since the gap is formed between the individual patterns of the phosphor layer by stretching the base film, the pickup can be easily performed. The base film is preferably plastically deformed when stretched.

The tensile elongation at break of the substrate film is preferably 50% or more, and more preferably 100% or more. When the tensile elongation at break is 50% or more, the gap between the individual patterns of the phosphor layer formed by stretching can be widened, and pickup can be performed more easily.

The film thickness of the substrate film is not particularly limited, but the lower limit is preferably 10 μm or more, and more preferably 20 μm or more. Moreover, as an upper limit, 1000 micrometers or less are preferable and 500 micrometers or less are more preferable.

As the pressure-sensitive adhesive material for forming the pressure-sensitive adhesive layer, an ultraviolet curable pressure-sensitive adhesive whose adhesive strength is reduced by irradiation with ultraviolet rays can be used. For example, a general pressure-sensitive pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive or a silicone pressure-sensitive adhesive. In addition, a pressure-sensitive adhesive containing an ultraviolet curable monomer component or oligomer component can be employed.

In addition, a material in which the component contained therein is foamed by heating to reduce the contact area with the adherend, and as a result, a material whose adhesive force with the adherend is reduced can also be used. For example, a pressure-sensitive adhesive in which a thermal foaming agent is blended with a general pressure-sensitive pressure-sensitive adhesive such as an acrylic pressure-sensitive adhesive or a silicone pressure-sensitive adhesive can be used as the pressure-sensitive adhesive layer. Examples of the thermal foaming agent include a pyrolytic foaming agent and expanded graphite. Examples of the pyrolytic foaming agent include ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, azides, azo compounds, hydrazine compounds, semicarbazide compounds, and the like.

The thickness of the pressure-sensitive adhesive layer is, for example, 10 μm or more, preferably 20 μm or more, and 500 μm or less, preferably 200 μm or less.

The base film having the pressure-sensitive adhesive layer is not limited to these, but includes, for example, UHP series manufactured by Denki Kagaku Kogyo Co., Ltd. and Riba Alpha series manufactured by Nitto Denko Corporation.

Also, the base film is not necessarily a film in which an adhesive layer is laminated or a coated paper, and a single layer can also be used. For example, there is an adhesive film produced by forming a resin containing an acrylate copolymer polymer, a photoinitiator, and an ultraviolet absorber into a sheet, and then irradiating ultraviolet rays from one side of the sheet. By making the amount of UV irradiation appropriate, the surface irradiated with UV light has a low adhesive force because the crosslinking reaction is promoted, and the surface not irradiated with UV light has sufficient adhesive strength. Film is obtained.

<Method for producing phosphor sheet>
Next, a method for producing the phosphor sheet will be described in detail. In addition, the following is an example and the preparation method of a fluorescent substance sheet is not limited to this.

There is a method of directly applying a phosphor layer to a substrate film as one method for producing a phosphor sheet. In the method, first, a solution in which a phosphor is dispersed in a resin (hereinafter referred to as “phosphor layer preparation resin solution”) is prepared as a coating solution for forming a phosphor layer. The resin liquid for producing the phosphor layer is obtained by mixing the phosphor and the resin in a solvent.

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 the components necessary for constituting the phosphor layer and components such as a solvent to be added as necessary to have a predetermined composition, a homogenizer, a self-revolving stirrer, three rollers, a ball mill, a planetary ball mill The resin solution for preparing the phosphor layer can be obtained by homogeneously mixing and dispersing with a stirrer / kneader such as a bead mill. Defoaming is preferably carried out under vacuum or reduced pressure conditions after mixing or dispersing.

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

The phosphor layer can be dried using a general heating device such as a hot air dryer or an infrared dryer. For heating and curing of the phosphor layer, 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.

Another method for creating a phosphor sheet is to form a phosphor layer on a substrate film that has been subjected to a release treatment in advance, and then peel the phosphor layer from the substrate film that has been subjected to a release treatment, There is a method of arranging on a material film. This method is preferably used when the substrate film necessary for achieving the desired adhesive strengths A and B cannot withstand the heat curing conditions of the phosphor layer.

<Light emitting device>
The light-emitting device that can be manufactured by the method of the present invention is not particularly limited, and can be widely applied to display backlights used in televisions, personal computers, mobile phones, game machines, etc., in-vehicle fields such as car headlights, and general lighting. .

<Manufacturing method of display device>
The display device is not particularly limited, and examples include a liquid crystal display, a traffic light, an electric bulletin board, and a projector. A display device to which the present invention can be preferably applied preferably includes a liquid crystal panel and a backlight unit.

The liquid crystal panel is manufactured as follows. First, a transparent substrate is prepared. On one surface of the transparent substrate, a non-conductive black matrix pattern is formed, a conductive black matrix pattern is formed, and an electrode line is formed. Subsequently, a red color filter, a green color filter, and a blue color filter are sequentially formed to form a transparent insulating layer. A conductive electrode layer and an electrode wire are formed on the other surface of the transparent substrate. Finally, a liquid crystal layer and a TFT substrate are bonded together on the transparent insulating layer. The liquid crystal panel is completed through the above steps.

There are two types of backlight units: edge type and direct type. The edge type backlight includes a light emitting device, a reflection plate, and a light guide plate. The light guide plate and the reflection plate are arranged to face each other. The light guide plate has an incident surface on which light from the light emitting device is incident on its end surface, and changes the traveling direction of the light incident on the incident surface from the light emitting device to a direction perpendicular to the light emitting device. The backlight unit is preferably formed by inserting an optical film such as a prism sheet, a diffusion plate, or a prism film.

The direct type backlight unit includes a plurality of light emitting devices arranged at predetermined intervals on a substrate such as a PCB (printed circuit board). It is preferable that the diffusing plate is disposed so as to face the PCB.

The display device is completed by placing a liquid crystal panel on the light extraction surface of the backlight unit.

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

<Silicone resin>
Silicone resin 1: OE-6630A / B (manufactured by Dow Corning Toray)
Silicone resin 2: heat-sealing silicone resin.

The heat-sealing silicone resin is a crosslinked product obtained by hydrosilylation reaction of a crosslinkable silicone composition containing at least the following compositions (A) to (D).
(A) Average unit formula:
(R ¹ ₂ SiO _2/2 ) _a (R ¹ SiO _3/2 ) _b (R ² O _1/2 ) _c
(Wherein R ¹ is a phenyl group, an alkyl or cycloalkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, provided that 65 to 75 mol% of R ¹ is phenyl. 10 to 20 mol% of R ¹ is an alkenyl group, R 2 is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and a, b, and c are 0.5 ≦ a ≦ 0.6. , 0.4 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.1, and a + b = 1.) Organopolysiloxane (B) General formula:
R ³ ₃ SiO (R ³ ₂ SiO) _m SiR ³ ₃
(Wherein R ³ is a phenyl group, an alkyl or cycloalkyl group having 1 to 6 carbon atoms, or an alkenyl group having 2 to 6 carbon atoms, provided that 40 to 70 mol% of R ³ is phenyl. And at least one of R ³ is an alkenyl group, and m is an integer of 5 to 50.) {5 to 15 parts by weight relative to 100 parts by weight of component (A)}
(C) General formula:
(HR ⁴ ₂ SiO) ₂ SiR ⁴ ₂
Wherein R ⁴ is a phenyl group, or an alkyl or cycloalkyl group having 1 to 6 carbon atoms, provided that 30 to 70 mol% of R ⁴ is phenyl. {Amount in which the molar ratio of silicon atom-bonded hydrogen atoms in this component to the total of alkenyl groups in component (A) and (B) is 0.5 to 2}, and (D) catalyst for hydrosilylation reaction A crosslinkable silicone composition comprising at least {a sufficient amount for promoting a hydrosilylation reaction between an alkenyl group in component (A) and component (B) and a silicon atom-bonded hydrogen atom in component (C)}.

<Phosphor>
Phosphor 1: NYAG-02 (manufactured by Intematix: Ce-activated YAG phosphor)
Phosphor 2: KSF phosphor (manufactured by Nemotomi Material Co., Ltd.).

<Silicon fine particles>
Silicone fine particles: Production method is as follows: A 2 L four-necked round bottom flask is equipped with a stirrer, thermometer, reflux tube, and dropping funnel, and the flask contains 2.5 ppm of polyether-modified siloxane “BYK333” as a surfactant. 2 L of aqueous ammonia was added, 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. 600 mL of water was added twice to the produced particles on the filter and 200 mL of methanol was added 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.

<Base film>
PET film 1: “Therapy” HP2 (manufactured by Toray Film Processing Co., Ltd.)
PET film 2: “Therapy” BX9 (Toray Film Processing Co., Ltd.)
Adhesive film 1: NO. 636095 (manufactured by Hitachi Maxell)
Adhesive film 2: TRO-9520 (manufactured by Tsukasa Trading Co., Ltd.)
Adhesive film 3: TRV214C (UV) (manufactured by Tsukasa Trading Co., Ltd.)
Adhesive film 4: TRV-9925 (manufactured by Tsukasa Trading Co., Ltd.)
Adhesive film 5: UC3004M-80 (Furukawa Electric Co., Ltd.).

<Measurement of tensile modulus and elongation at break>
Measurement of the tensile modulus of elasticity and tensile elongation at break of the substrate film was carried out as follows. Each base film was cut with a razor to prepare 10 test pieces having a size of 10 mm × 60 mm (inside, gripping part is 5 mm at both ends). Using Tensilon UTM-II-20 (manufactured by Toyo Baldwin Co., Ltd.), which is a tensile tester according to JIS-B-7721 (2009), 5 mm at both ends of the test piece The sample was attached and fixed to a gripping tool (15 mm spacing between gripping tools), and a tensile test was performed at a tensile speed of 50 mm / min (under an environment of 25 ° C. and 50% RH). Tensile modulus and tensile elongation at break were determined according to JIS-K-7127 (1999).

<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 layer sample. The cross section of the phosphor layer 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 size distribution. At this time, when the particles were spherical, the particle diameter was taken as the particle size. When the particles were not spherical, the average value of the longest diameter and the shortest diameter was taken as the particle size. In the particle size distribution, the particle diameter of 50% accumulated from the small particle diameter side was determined as the median diameter (D50).

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

<Measurement of storage modulus>
The produced phosphor layer was cut into a diameter of 15 mmφ to obtain a measurement sample, and the storage elastic modulus at room temperature (25 ° C.) was measured using a dynamic viscoelasticity measuring device (HAAKE MARS III) manufactured by Eiko Seiki Co., Ltd.

<Processability evaluation>
The prepared phosphor sheets are cut into a substantially square shape with a cutting device (GCUT manufactured by UHT), and 400 individual sheets having phosphor layers with sides of 0.1 mm, 0.3 mm, and 1 mm are prepared. did. Under the microscope, the number of burrs and sheet chips observed on the cut surface of the phosphor layer, the re-attachment of the phosphor sheet cross section at the cut location, and the total number of the phosphor layer peeled off from the substrate film ( The number of processing defects was confirmed below. The smaller the number of processing defects, the better the workability. If it is more than evaluation B, it can be judged that there is no problem in practical use.
S: Number of processing defects 0 to 20 Excellent workability.
A: Number of processing defects 21 to 60 Good workability.
B: Number of processing defects 61 to 120 There is no practical problem in workability.
C: 121-240 processing defects The processability is poor.
D: Number of processing defects 241 or more Processability is very poor.

<Pickup evaluation>
Pickup was performed on 100 individual phosphor layers by a pickup device (manufactured by Toray Engineering). The smaller the number of pickup failures, the better the pickup performance. The term “pickup failure” as used herein refers to the total number of cracks or chips generated in the individual phosphor layers at the time of pick-up or the occurrence of peeling in portions other than the phosphor layer to be picked up. If it is more than evaluation B, it can be judged that it is excellent practically.
S: Number of pick-up defects 0-5 Pick-up property is very good.
A: Number of pick-up defects 6-15 Good pick-up performance.
B: Number of pick-up defects 16 to 30 Pick-up property has no practical problem.
C: 31-60 pick-up defects The pick-up property is poor.
D: Number of pick-up defects 61 or more Pick-up property is very bad.

<Preparation of phosphor sheet>
Using a polyethylene container having a volume of 300 ml, silicone resin, phosphor and silicone fine particles were mixed at a predetermined ratio. 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 preparing a phosphor layer. A phosphor-dispersed silicone resin solution for preparing a phosphor layer was applied onto the PET film 2 using a slit die coater, and kept at 120 ° C. for a predetermined time to be dried. Then, if necessary, the phosphor layer was pasted to the adhesive layer side of the adhesive film using a Nichigo Morton laminator V160.

The composition of the phosphor layer prepared in this study is as shown in Table 1.

<Method for manufacturing light emitting device>
Using a die bonding apparatus (manufactured by Toray Engineering Co., Ltd.), the phosphor layer cut into 1 mm square is vacuum-adsorbed with a collet and peeled off from the base material, and conveyed to the substrate on which the flip chip type blue LED light emitting element is mounted. The LED light emitting element surface was aligned and pasted. At this time, when the phosphor layer had heat-fusibility, it was attached by pressing the collet while heating at 100 ° C. When the phosphor layer did not have heat-fusibility, an adhesive was applied in advance on the flip-chip blue LED light-emitting element, and the phosphor layer was attached via the adhesive. Silicone resin 1 was used as the adhesive. An LED with the same phosphor sheet was sealed with a transparent resin and connected to a DC power source.

<Measurement of chromaticity and total luminous flux of light emitting device>
The manufactured light-emitting device was turned on by turning on the LED element, and using the total luminous flux measurement system (HM-3000, manufactured by Otsuka Electronics Co., Ltd.), the chromaticity (x, y) of the CIE1931 XYZ color system and Total luminous flux (lm) was measured.

(Examples 1 to 8) -Comparison of storage modulus of phosphor sheet-
The phosphor sheet was produced by the above-described method at the drying time shown in Table 2. In addition, the adhesive film 1 was used in all of Examples 1 to 8 when the phosphor layer was replaced by a laminator.

Each phosphor layer was peeled off from the base film, and a part was cut out to 15 mmφ to obtain a measurement sample, and the storage elastic modulus was measured by the method described above. A part of each phosphor sheet was cut out, and the adhesive strength A was measured by the method described above. Further, a part of each phosphor sheet was cut out and irradiated with 300 mJ / cm ² of ultraviolet light of 365 nm using an ultraviolet irradiator ELC-500 manufactured by Electro Lite, and the adhesive strength B was measured by the method described above.

Each phosphor sheet is cut into 2 cm squares, and a blade is inserted from the phosphor layer side using a cutting device (GCUT manufactured by UHT). The phosphor layers are individually divided into 0.1 mm square, 0.3 mm square, and 1 mm square. 400 pieces of phosphor sheets (hereinafter referred to as individualized sheets) were produced. At this time, the phosphor layer portion was so-called half cut that the blade penetrated but the base film portion did not penetrate. The processability of each phosphor sheet was evaluated by the method described above.

Next, a phosphor sheet with a phosphor layer separated into 1 mm square is used after irradiating ultraviolet light of 365 nm with 300 mJ / cm ² using an ELL-500 UV irradiator manufactured by Electro Lite. Then, the pickup property was evaluated by the method described above.

Table 2 shows the storage elastic modulus, adhesive strength A, adhesive strength B, processability evaluation result, and pickup property evaluation result of each phosphor sheet. In order to produce a 1 mm square individualized sheet, the storage elastic modulus of the phosphor sheet is preferably 0.1 Mpa or more, more preferably 1 Mpa or more, and preferably 2000 MPa or less. I understood. In order to produce a 0.3 mm square individualized sheet, the storage elastic modulus of the phosphor sheet is preferably 1 Mpa or more, more preferably 100 Mpa or more, and preferably 1000 MPa or less. I understood. It was found that the storage elastic modulus of the phosphor sheet is preferably 100 Mpa or more and more preferably 1000 MPa or less in order to produce a 0.1 mm square individualized sheet.

Ten LED light-emitting devices were manufactured using the phosphor sheet of Example 4, and the average value of chromaticity and the average value of all luminous fluxes of the ten light-emitting devices were obtained. The chromaticity and total luminous flux evaluation results of the light emitting device are shown in Table 5 together with Examples 12, 13, and 14 described later.

(Examples 5 and 9, Comparative Examples 1 to 4) -Adhesive strength-
In Example 9, a phosphor sheet was prepared in the same manner as in Example 5 except that the adhesive film for replacing the phosphor layer was changed to the adhesive film 2.

In Comparative Example 1, a phosphor sheet was prepared in the same manner as in Example 5 except that PET film 1 was used as the base film and the adhesive film was not replaced.

In Comparative Example 2, a phosphor sheet was prepared in the same manner as in Example 5 except that the adhesive film was not replaced.

In Comparative Example 3, a phosphor sheet was produced in the same manner as in Example 5 except that the adhesive film for replacing the phosphor layer was changed to the adhesive film 5.

In Comparative Example 4, a phosphor sheet was prepared by the same operation as in Example 5, and the same operation as in Example 5 was performed except that the amount of ultraviolet irradiation before evaluation of the pickup property was 50 mJ / cm ² .

The measurement of adhesive strength A and adhesive strength B, workability evaluation, and pickup property evaluation were performed on the obtained phosphor sheet in the same manner as in Example 5. The results are as shown in Table 3. The results of Example 5 are shown again. As for Comparative Example 2, a sample for evaluating the pickup property could not be obtained.

It was found that the adhesive strength A is preferably 5.0 N / cm or more. In particular, it was found that the adhesive strength A is more preferably 10 N / cm or more in order to produce a 0.1 mm square singulated sheet. Further, it was found that the adhesive strength B is preferably 0.1 N / cm or less. When the light emitting device was manufactured using the phosphor sheets of the respective examples, a light emitting device having good light emission intensity was obtained.

(Examples 5, 10, and 11) -Effect of stretching degree-
In Examples 10 and 11, the same operation as in Example 5 was performed except that the base film of the singulated sheet was stretched radially before pickup evaluation. The degree of stretching was calculated by the following formula.

4 shows the degree of stretching of the substrate and the evaluation results of pickup properties. It was found that the degree of stretching was preferably 0.5 or more, and more preferably 1.0 or more.

When a light emitting device was produced using the phosphor sheet of each example, a light emitting device having good light emission intensity was obtained.

(Examples 12, 13, and 14) -In the case of containing fine particles and in the case of heat-sealing resin-
In Examples 12 and 13, the same operation as in Example 4 was performed except that the composition of the phosphor layer was changed to the composition shown in Table 1.

In Example 14, the same operation as in Example 13 was performed except that the step of attaching the singulated phosphor sheet was performed in a vacuum atmosphere.

10 LED light emitting devices were produced for each example, and the average value of chromaticity and the average value of all luminous fluxes of the 10 light emitting devices were obtained. The results are shown in Table 5. The results of Example 4 are shown again.

It was found that the presence or absence of silicone fine particles did not affect the processability and pickup properties of the phosphor sheet.

It was found that the total luminous flux was improved by heating and sticking the phosphor sheet, and further improved by sticking in a vacuum atmosphere.

(Examples 15 and 16) -Storage stability-
In Example 15, a phosphor sheet was produced in the same manner as in Example 4 except that the adhesive film for replacing the phosphor layer was changed to the adhesive film 3.

In Example 16, a phosphor sheet was produced in the same manner as in Example 4 except that the adhesive film for replacing the phosphor layer was changed to the adhesive film 4.

The phosphor sheets produced in Examples 4, 15 and 16 were subjected to storage elastic modulus, adhesion strength A, adhesion strength B measurement, workability evaluation, and pickup property evaluation immediately after production and after storage for 6 months. The results are as shown in Table 6.

The phosphor sheet prepared in Example 15 had the storage elastic modulus of the phosphor layer significantly decreased after 6 months storage. This is because the plasticizer contained in the adhesive film oozes into the phosphor layer. As a result, the processability evaluation and pickup evaluation were also poor.

(Example 17) -Effects of individualized size on pickup-
In Example 17, the same operation as in Example 10 was performed, except that the phosphor layer was 0.1 mm, 0.3 mm, and phosphor sheets separated into 1 mm squares were used for pickup evaluation. The results are shown in Table 7. It has been found that the pick-up property is improved when the individualized size is 0.3 mm square or less.

DESCRIPTION OF SYMBOLS 1 Phosphor 2 Phosphor layer 3 Adhesive layer 4 Film 5 Adhesive film 6 Phosphor sheet 7 Diffusion layer 8 Transparent layer 9 Cutlery 10 Separated sheet 11 Collet 12 LED chip 13 Reflector 14 Mounting substrate 15 Transparent sealing material 16 Dividing line 17 gap

Claims

A step of separating the phosphor layer in a phosphor sheet having a phosphor layer on a base film, a step of performing heat treatment or ultraviolet irradiation on the phosphor sheet in which the phosphor layer is separated, and A manufacturing method including a step of picking up an individualized phosphor layer and a step of attaching the individualized phosphor layer to an LED chip, wherein the method is performed at room temperature before the heat treatment or ultraviolet irradiation. Adhesive strength A between the phosphor layer and the substrate film, and an adhesive strength B between the phosphor layer and the substrate film at room temperature after the heat treatment or ultraviolet irradiation,
A = 5.0 N / cm or more and B = 0.1 N / cm or less.
The method for manufacturing a light-emitting device according to claim 1, wherein a length of at least one side of the separated phosphor layer is 0.1 mm or more and 0.3 mm or less.
The method for manufacturing a light emitting device according to claim 1, wherein the phosphor layer has a storage elastic modulus at 25 ° C. of 100 MPa or more and 2000 MPa or less.
The method for manufacturing a light emitting device according to any one of claims 1 to 3, wherein the base film is a base film containing no plasticizer.
The method for manufacturing a light emitting device according to any one of claims 1 to 4, further comprising a step of stretching a base film after the step of separating the phosphor layers into individual pieces.
The method for manufacturing a light emitting device according to claim 5, wherein in the step of stretching the base film, the stretch degree of the base film is 0.5 or more.
The method for manufacturing a light-emitting device according to any one of claims 1 to 6, wherein the method of dividing the phosphor layer into pieces is cutting by dry cutting.
8. The method for manufacturing a light emitting device according to claim 1, wherein in the step of attaching the phosphor layer to the LED chip, the phosphor layer is heated and attached.
The method for manufacturing a light emitting device according to claim 8, wherein the step of heating and attaching the phosphor layer is performed in a vacuum atmosphere.
The method for manufacturing a light emitting device according to any one of claims 1 to 9, wherein a ratio of the phosphor in the total solid content in the phosphor layer is 60 wt% or more and 90 wt% or less.
The phosphor layer has the general formula A 2 MF 6 : Mn (where A is selected from the group consisting of Li, Na, K, Rb and Cs, and at least one alkali metal containing Na and / or K) And M is one or more tetravalent elements selected from the group consisting of Si, Ti, Zr, Hf, Ge, and Sn.) The manufacturing method of the light-emitting device in any one.
A method for manufacturing a display device, comprising a step of manufacturing a light emitting device by the manufacturing method according to any one of claims 1 to 11.