JP5730559B2 - Optical semiconductor device - Google Patents

Description

  The present invention relates to an optical semiconductor device. More specifically, the present invention relates to an optical semiconductor device that is collectively sealed with an optical semiconductor element sealing sheet, and a method for manufacturing the device.

  Instead of incandescent bulbs and fluorescent lamps, light-emitting devices of optical semiconductors (light-emitting diodes, LEDs) have become widespread. There are various types of white LED devices, but there is a light-emitting form that emits white with a mixed color of blue and yellow by using a blue light-emitting element and dispersing a phosphor that converts blue to yellow in a sealing resin. It is the mainstream of current white LED devices.

  In recent years, the development of light-emitting elements has been progressing at a rapid pace, replacing the low-brightness white package, which is mainly a conventional shell type, with a high-brightness white LED that can also be used as a backlight for general lighting equipment and LCD TVs. Packages are becoming mainstream. Therefore, an epoxy resin that has been used as a sealing resin conventionally has a problem that transparency is deteriorated due to deterioration due to light and heat, and a resin with little deterioration such as silicone is being used. On the other hand, although the silicone resin has good durability, it is usually necessary to mold the package from a liquid state, and poor workability at the time of sealing is a cause of low throughput and high cost.

  For these reasons, a sealing method using a sealing sheet is proposed instead of a sealing method using a liquid material, and the workability is greatly improved. Moreover, since the light extraction efficiency can be improved by disposing the wavelength conversion layer away from the light emitting element, that is, on the outermost side of the package, a uniform wavelength conversion layer can be easily formed on the outermost layer of the device. In view of the point that it can be formed, a method for manufacturing a package using a sealing sheet has attracted attention.

  Fabrication of a package using a sealing sheet is usually performed by placing a sealing sheet and a concave mold on a light emitting element in this order and performing pressure molding. In this case, a uniform wavelength conversion layer is formed on the outermost side of the package on both the upper surface and the side surface (lateral portion) of the light emitting element. Therefore, the light extraction efficiency is high and a bright device can be obtained.

  However, when the orientation state of emitted light, that is, the color distribution of light at each angle at which light is emitted is examined in detail, the light emitted in the wide-angle direction becomes darker than the light emitted in the front direction. There is a tendency. This is because the light emitted in the wide-angle direction passes through the wavelength conversion layer for a longer distance than the front direction. Therefore, in a package with a relatively low height manufactured using a sealing sheet, the chromaticity difference for each angle, that is, the angle dependency of chromaticity is large. The difference in chromaticity of light becomes a problem.

  In order to remedy this problem, a dome-shaped package has been proposed in which the height of the package is increased and the lateral wavelength conversion layer is arranged so as to be perpendicular to the light emitting element in all planes. (See Patent Document 1).

JP 2005-327841 A

  The dome-shaped package is not satisfactory because it has a manufacturing problem that is difficult to make and is contrary to the trend of recent thin packages. Therefore, a package that can be easily manufactured using a sealing sheet and is thin and has a low angle dependency is desired.

  An object of the present invention is to provide an optical semiconductor device that can be easily manufactured using a sealing sheet and is thin and has a low chromaticity angle dependency, and a method for manufacturing the device.

The present invention provides an optical semiconductor element sealing sheet comprising a sealing resin layer in which an optical semiconductor element can be embedded and a wavelength conversion layer having a thickness of 50 to 200 μm containing optical wavelength conversion particles, which are directly or indirectly laminated. , a method of manufacturing an optical semiconductor device molded using the concave mold arranged so that the sealing resin layer faces the optical semiconductor element mounting substrate, the previous SL concave mold, the area of the bottom surface of the recess and the recess of the total area of the area of the side surface, the recess bottom area of 40% or more, have a recess structure that satisfies the less than 60 percent, and the shape of the concave bottom surface with a square or circular der Ru mold, obtained The present invention relates to a method for manufacturing an optical semiconductor device, in which a molded body has a rectangular parallelepiped shape or a cylindrical shape, a wavelength conversion layer is formed on an upper surface and a side surface of the molded body, and the molded body is molded to have a height of 500 to 1500 μm .

  Since the optical semiconductor device of the present invention can be easily manufactured using a sealing sheet and has a small thickness and low chromaticity angle dependency, it can emit light of uniform color over all angles. it can.

FIG. 1 is a diagram illustrating optical semiconductor devices of Examples 1 to 3 and Comparative Examples 1 to 5. FIG. 2 is a diagram illustrating optical semiconductor devices of Examples 4 to 5. FIG. 3 is a diagram illustrating an optical semiconductor device according to the sixth embodiment. FIG. 4 is a diagram illustrating a dome-shaped optical semiconductor device of Reference Example 1.

  In the optical semiconductor device of the present invention, a sealing resin layer capable of embedding an optical semiconductor element (also referred to as an LED chip or simply an element) and a wavelength conversion layer containing light wavelength conversion particles are directly or indirectly laminated. A molded body in which an optical semiconductor element is embedded using an optical semiconductor element sealing sheet, the sealing resin layer being disposed so as to face the optical semiconductor element mounting substrate and molded using a concave mold. A major feature is that the area of the upper surface of the package (also referred to as a package) is 40% or more and less than 60% of the total area of the upper surface area and the side surface area of the molded body. In the present specification, the area of the upper surface of the molded body refers to the total surface area of the portion parallel (flat) to the substrate that is visible when the molded body is viewed from directly above, and the area of the side surface of the molded body. Means the total surface area of the part perpendicular to the substrate, which is visible when the molded body is viewed from all lateral directions (entire circumference). Specifically, for example, when the molded body has a two-stage shape in which rectangular parallelepipeds are stacked up and down, the area of the upper surface is the upper surface area of the uppermost step and the exposed portion of the second step. Including the top surface area, the side surface area is the sum of the first side surface area and the second side surface area.

  In a general package, the distance that light emitted in the front direction (perpendicular to the optical semiconductor element mounting substrate) passes through the wavelength conversion layer is equal to the thickness of the wavelength conversion layer. However, since the light emitted in the wide-angle direction passes through the wavelength conversion layer obliquely, the passing distance becomes larger than the thickness of the wavelength conversion layer, and the light emitted in the wide angle receives the effect of wavelength conversion. For example, in the case of a package with a low height and a large top surface area, most of the light goes out of the top surface of the package, so a slightly bluish white light can be seen when viewed from directly above the package, but viewed from a wide angle. And dark yellow light emitted from the side of the package.

  In addition, since light emitted in the lateral direction (parallel to the optical semiconductor element mounting substrate) is radiated according to the same principle as described above, the light radiated in the lateral direction, that is, in the side surface direction, However, the light emitted from the wide-angle direction, that is, the front direction, passes through the wavelength conversion layer obliquely, and thus receives the effect of wavelength conversion. Therefore, on both the top and side surfaces of the package, light in both the vertical direction and the wide-angle direction is mixedly radiated with respect to each surface. It is estimated that the dependence will be uniform. Therefore, in the present invention, by setting the area ratio between the upper surface and the side surface of the package to be within a specific range, light of a uniform color is emitted over all angles.

  The optical semiconductor device of the present invention is one that is collectively sealed using an optical semiconductor element sealing sheet, and the optical semiconductor element sealing sheet includes an encapsulating resin layer and an optical wavelength in which the optical semiconductor element can be embedded. A wavelength conversion layer containing the conversion particles is included.

  The sealing resin layer is a layer that can embed an optical semiconductor element when it is molded by pressing a concave mold, but in addition to the flexibility of embedding the element at the time of sealing, an external impact is applied at the time of use. It is necessary to have strength to protect the device. From such a viewpoint, the encapsulating resin layer needs to have low elasticity (plasticity) capable of embedding the element and a property (post-curing property) for maintaining the shape after curing.

  The resin constituting the encapsulating resin layer having such characteristics is not particularly limited as long as it is a resin having both plasticity and post-curing property, but it is preferable to contain a silicone resin as a main component from the viewpoint of durability. In the present specification, the “main component” means 50% or more of the components constituting the resin layer.

  Silicone resins include silicone resins such as gels, semi-cured products, and cured products depending on the number of crosslinks of the siloxane skeleton, and these can be used alone or in combination of two or more. The stopping resin layer has a flexibility that allows the shape of the layer to change depending on the pressure at the time of sealing, and exhibits a strength that varies with temperature, such as a strength that can withstand impacts when cured. Therefore, a silicone resin having two reaction systems and a modified silicone resin are preferable.

  Examples of the silicone resin having two reaction systems include those having two reaction systems of silanol condensation reaction and epoxy reaction, and those having two reaction systems of silanol condensation reaction and hydrosilylation reaction (condensation-addition curing type). Silicone resin) is exemplified.

  The modified silicone resin is a resin having a heterosiloxane skeleton such as borosiloxane, aluminosiloxane, phosphor siloxane, titaner siloxane, etc., in which Si atoms in the siloxane skeleton are partially substituted with atoms such as B, Al, P, Ti, etc. In addition, a resin in which an organic functional group such as an epoxy group is added to a Si atom in the siloxane skeleton is exemplified. Of these, dimethylsiloxane has a low elasticity even with high crosslinking, and therefore, a modified silicone resin in which a hetero atom is incorporated into dimethylsiloxane or an organic functional group is added is more preferable. In order for the sealing resin layer to have the above strength, the number of crosslinks of the siloxane skeleton may be adjusted by a known method.

  These resins can be produced by a known production method, and will be described by taking a condensation-addition curable silicone resin as an example. For example, after adding tetramethylammonium hydroxide as a condensation catalyst to a mixture of both-end silanol type silicone oil, vinyl (trimethoxy) silane as an alkenyl group-containing silane compound, and an organic solvent, the mixture is stirred and mixed at room temperature for 2 hours. A condensation-addition curable silicone resin can be obtained by adding a platinum catalyst as an organohydrogensiloxane and a hydrosilylation catalyst and mixing them.

  The content of the silicone resin is preferably 70% by weight or more, more preferably 90% by weight or more, and still more preferably substantially 100% by weight in the resin constituting the sealing resin layer.

  Moreover, the sealing resin layer in this invention can contain an inorganic particle from a viewpoint of improving thermal conductivity and light diffusibility. Examples of the inorganic particles include silicon dioxide (silica), barium sulfate, barium carbonate, barium titanate and the like, and these can be used alone or in combination of two or more.

  The content of the inorganic particles in the sealing resin layer is preferably 10 to 70% by weight and more preferably 40 to 60% by weight from the viewpoint of thermal conductivity and light diffusibility.

  In addition to the above, the encapsulating resin layer contains additives such as a curing agent, a curing accelerator, an anti-aging agent, a modifier, a surfactant, a dye, a pigment, a discoloration inhibitor, and an ultraviolet absorber as raw materials. It may be. Even if these additives are contained, the sealing resin layer may be a resin layer having plasticity and post-curing property.

  For the sealing resin layer, the resin or an organic solvent solution of the resin is appropriately formed by, for example, casting, spin coating, roll coating, or the like on a separator (for example, biaxially stretched polyester film) whose surface has been released. It is formed into a sheet by forming the film to a proper thickness and further drying at a temperature at which the solvent can be removed without allowing the curing reaction to proceed. The temperature at which the formed resin solution is dried varies depending on the type of resin and solvent and cannot be determined unconditionally, but is preferably 80 to 150 ° C, more preferably 80 to 130 ° C. When a condensation-addition curable silicone resin is used, the condensation reaction proceeds by the drying, so that the obtained sheet-shaped sealing resin layer is semi-cured. In addition, you may use the sheet | seat obtained by laminating | stacking multiple sheets and heat-pressing at 20-180 degreeC, making it pressure-bonded, and integrating them as one sealing resin layer.

  The thickness of the sealing resin layer is not particularly limited as long as the LED chip can be embedded, and may be larger than the thickness of the LED chip, preferably 200 μm or more, and more preferably 500 μm or more. Further, from the viewpoint of facilitating heat generation due to wavelength conversion of the phosphor to the optical semiconductor element side, it is preferably 5000 μm or less, and more preferably 3000 μm or less. Therefore, the thickness of the sealing resin layer in the present invention is preferably 200 to 5000 μm, and more preferably 500 to 3000 μm.

The sealing resin layer in the present invention is in a sheet state at room temperature, and from the viewpoint of easy peeling from the separator, the storage elastic modulus at 23 ° C. is preferably 1.0 × 10 ⁴ Pa or more (0.01 MPa or more). More preferably, it is 2.0 × 10 ^{4 to} 1.0 × 10 ⁶ Pa (0.02 to 1.0 MPa), and the storage elastic modulus at 150 ° C. is preferably 1.0 × 10 ⁶ Pa or less (1.0 MPa or less), more preferably 1.0 × 10 ^{4 to} 1.0 × 10 ⁵ Pa (0.01 to 0.1 MPa). The storage elastic modulus at 23 ° C. after curing at 150 ° C. for 5 hours is preferably 1.0 × 10 ⁶ Pa or more (1.0 MPa or more), more preferably 1.0 × 10 ^{6 to} 1.0 × 10 ⁷ Pa (1.0 to 10 MPa). It is.

  The wavelength conversion layer is a resin layer containing light wavelength conversion particles, and a part of the light from the device is wavelength-converted and mixed with the light emission from the LED chip, thereby adjusting the light emission of a desired color. Can do. Moreover, in this invention, it is preferable to arrange | position a wavelength conversion layer in the outermost part of a package from a viewpoint which suppresses that the light reflected by the wavelength conversion layer reaches | attains an LED chip with a high refractive index.

The light wavelength conversion particles (phosphor) in the wavelength conversion layer are not particularly limited and include known phosphors used in optical semiconductor devices. Specifically, yellow phosphors (α-sialon), YAG, TAG, etc. are exemplified as suitable commercially available phosphors having a function of converting blue to yellow, and suitable commercially available phosphors having a function of converting red. Examples of the product phosphor include CaAlSiN ₃ . These phosphors can be used alone or in combination of two or more.

  The content of the light wavelength conversion particles is not determined unconditionally because the degree of color mixing varies depending on the thickness of the wavelength conversion layer.For example, when the thickness of the wavelength conversion layer is 100 μm, the content of the light wavelength conversion particles is It is preferably 10 to 30% by weight.

  The resin in the wavelength conversion layer is not particularly limited as long as it is a resin that has been conventionally used for optical semiconductor encapsulation, and examples thereof include transparent resins such as epoxy resins, acrylic resins, and silicone resins. Resins are preferred.

  Examples of the silicone resin include the same silicone resins listed above, and those that are commercially available may be used, or those that are separately manufactured may be used.

  In the wavelength conversion layer, in addition to the resin and the light wavelength conversion particles, the same additive as the sealing resin layer may be blended as a raw material.

  The wavelength conversion layer is a resin containing the light wavelength conversion particles or an organic solvent solution of the resin, for example, on a separator (for example, a polyester film, a polypropylene film) whose surface has been subjected to a release treatment, spin coating, roll coating. The film is formed into an appropriate thickness by a method such as that described above, and further dried at a temperature at which the solvent can be removed without allowing the curing reaction to proceed. The temperature at which the formed resin solution is dried cannot be determined unconditionally because it varies depending on the type of resin or solvent, but is preferably 80 to 150 ° C, more preferably 90 to 150 ° C.

  The sheet thickness of the wavelength conversion layer after heat drying is preferably 50 to 200 μm, more preferably 70 to 120 μm, from the viewpoint of improving light extraction efficiency. In addition, the obtained sheet | seat can also be shape | molded as one sheet | seat which has the thickness of the said range by laminating | stacking several sheets and carrying out the hot press. At that time, a plurality of wavelength conversion layers containing different kinds of light wavelength conversion particles may be used.

The storage elastic modulus at 150 ° C. of the wavelength conversion layer is preferably 1.0 × 10 ⁵ Pa or more (0.1 MPa or more) because the color of the package changes when the thickness of the layer is deformed, and 1.0 × 10 ^{6 to} 1.0 × 10 ⁸ Pa (1.0 to 100 MPa) is more preferable.

  The sheet for encapsulating an optical semiconductor element in the present invention is not particularly limited as long as it has the sealing resin layer and the wavelength conversion layer, but may have a separator, and the wavelength conversion layer may be formed on the separator. The sealing resin layers are preferably laminated in this order.

  Any separator can be used as long as it can be peeled off from the wavelength conversion layer, but in the peeling stage, that is, when the sheet is molded after peeling the separator from the optical semiconductor element sealing sheet, and the optical semiconductor element sealing sheet is molded. Different materials may be used depending on the case where the separator is peeled off later.

  The separator that can be used when sheet molding is performed after peeling the separator is not particularly limited as long as the surface of the wavelength conversion layer can be covered and protected, and examples thereof include a polyester film and a polyethylene terephthalate film.

On the other hand, as a separator that can be used when the separator is peeled off after sheet molding, mold followability at the time of molding is required, so that it is rigid at room temperature, but has a storage temperature of, for example, 150 ° C. Examples include materials that are 1.0 × 10 ⁸ Pa or less. Specific examples include polystyrene film, polypropylene film, polycarbonate film, acrylic film, silicone resin film, styrene resin film, and fluororesin film.

  In the present invention, from the viewpoint of facilitating peeling from the wavelength conversion layer, the separator surface subjected to a release treatment according to a known method may be used.

  Although the thickness of a separator is not specifically limited, When making it follow a metal mold | die, 20-100 micrometers is preferable and 30-50 micrometers is more preferable.

  The method for laminating the sealing resin layer and the wavelength conversion layer is not particularly limited. For example, when the sealing resin layer is formed into a sheet shape, the sealing is directly performed on the wavelength conversion layer formed on the separator. A method of molding and laminating a resin layer can be mentioned. In the present specification, the “directly laminated” sheet means a sheet formed by directly laminating the sealing resin layer and the wavelength conversion layer, and “indirectly laminated” The sheet is a sheet formed by laminating another layer between the sealing resin layer and the wavelength conversion layer according to a conventional method.

  The optical semiconductor element sealing sheet thus obtained is placed so that the sealing resin layer faces the optical semiconductor element mounting substrate, and a concave mold is placed thereon and molded. A semiconductor device is obtained.

  The optical semiconductor element used in the present invention is not particularly limited as long as it is usually used in an optical semiconductor device. For example, gallium nitride (GaN, refractive index: 2.5), gallium phosphide (GaP, refractive index: 2.9) And gallium arsenide (GaAs, refractive index: 3.5). Among these, GaN is preferable from the viewpoint of emitting blue light and producing a white LED via a phosphor.

  The substrate on which the optical semiconductor element is mounted is not particularly limited, and examples thereof include a metal substrate, a rigid substrate in which copper wiring is laminated on a glass-epoxy substrate, and a flexible substrate in which copper wiring is laminated on a polyimide film. Any form such as an uneven plate can be used.

  As a method for mounting the optical semiconductor element on the substrate, a face-up mounting method suitable for mounting an optical semiconductor element in which an electrode is disposed on a light emitting surface, and light in which an electrode is disposed on a surface opposite to the light emitting surface. A flip chip mounting method suitable for mounting a semiconductor element can be used.

  The molding method is not particularly limited as long as the wavelength conversion layer of the optical semiconductor element sealing sheet is arranged with a uniform thickness on the side surface of the package and the area of the top surface and the side surface of the package after molding is a specific ratio. Absent. As a specific method, for example, an optical semiconductor element sealing sheet is disposed on a flat substrate on which an LED chip is mounted so that the sealing resin layer faces the substrate, and a separator is attached. There is a method in which the concave mold and the separator are peeled in order after pressing the concave mold as it is and molding.

  There are no particular limitations on the molding conditions using the concave mold, but the heating temperature is preferably 80 to 200 ° C, more preferably 100 to 160 ° C. The heating time is preferably 1 to 60 minutes, and more preferably 5 to 20 minutes. Further, it may be molded under normal pressure (101.3 kPa), but may be molded under reduced pressure from the viewpoint of preventing air bubbles from entering the resin layer.

  Examples of the concave mold include those having a concave structure from which a package described later can be obtained. That is, the present invention has one feature in that a concave mold having a specific concave structure is used so that the ratio of the top surface area to the side surface area of the molded body to be obtained is within a certain range. The concave mold used in the present invention has an area ratio such that the area of the bottom of the recess and the area of the side of the recess satisfy the above-mentioned area ratio of the molded body, the bottom of the recess is flat, and the side of the recess is It is arranged perpendicular to the bottom.

  After the pressure molding, before the concave mold or the separator is peeled off, post-cure may be performed by heating and pressurizing until the time required for curing the sealing resin layer. The post cure conditions are not particularly limited.

  Further, in the present invention, when disposing the sheet for sealing an optical semiconductor element on the LED chip, from the viewpoint of preventing the wire around the LED chip from being damaged by external force or pressure during molding, the LED chip and It may be protected by dropping a protective resin (also referred to as potting resin) on the peripheral wire and drying by heating.

  The potting resin is not particularly limited as long as it is a resin conventionally used for optical semiconductor encapsulation, and from the viewpoint of thermal conductivity and light diffusibility, additives include silicon dioxide (silica), barium sulfate, carbonic acid. Inorganic particles such as barium and barium titanate can be contained.

  If potting resin can coat | cover an LED chip and its periphery wire, the usage-amount will not be restrict | limited in particular.

  The molded package may be post-cured by heating and pressurizing until the time required for curing of the sealing resin layer is allowed to stand until the shape does not change even at room temperature.

  The shape of the obtained package is not particularly limited, and examples thereof include a rectangular parallelepiped, a cube, a cylinder, and a stepped structure.

As the size of the package, since the heat generated in the wavelength conversion layer tends to be trapped if it is too small, the surface area of the outermost layer is preferably 20 mm ² or more. Moreover, because of a problem such as deterioration and an increase in the handling of the used resin amount is too large, the surface area of the outermost layer is 300 mm ² or less. The surface area of the outermost layer here means the sum of the area of the upper surface of the molded body and the area of the side surface of the molded body.

  The height of the package is not particularly limited, but is preferably 500 to 5000 μm, and more preferably 800 to 3000 μm.

  In addition, the present invention is characterized in that light emission with uniform chromaticity can be obtained because the area ratio between the upper surface and the side surface of the package is specific. That is, the area of the upper surface of the package occupies 40% or more and less than 60%, preferably 45 to 55% of the total area of the package upper surface area and the side surface area. In order to achieve the area ratio, the height of the package and the size (planar area) of the package may be appropriately adjusted to an arbitrary ratio.

  The optical semiconductor device of the present invention thus obtained can be encapsulated using the optical semiconductor element encapsulating sheet, and the wavelength conversion layer in the sheet is located on the outermost layer of the package, so that the light extraction efficiency is improved. Excellent light emission with uniform chromaticity can be obtained.

  Moreover, in this invention, the manufacturing method of the optical semiconductor device sealed using the said sheet | seat for optical semiconductor element sealing is provided. The manufacturing method includes a step of arranging the optical semiconductor element sealing sheet so that the sealing resin layer faces the optical semiconductor element mounting substrate and molding the sheet using a concave mold. There is no particular limitation as long as a concave mold having a structure is used. Specifically, the optical semiconductor element sealing sheet of the present invention is disposed so that the sealing resin layer faces the optical semiconductor element mounting substrate, and a concave mold is pressed thereon, preferably 100 to 160. A method of molding at 0 ° C. can be mentioned.

  The optical semiconductor device of the present invention thus obtained is preferably used as a light emitting device of an optical semiconductor because it has excellent light extraction efficiency and can emit light with uniform chromaticity.

  EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, a comparative example, and a reference example, this invention is not limited at all by these Examples. Here, “room temperature” means 20 to 30 ° C.

Preparation example 1 of optical semiconductor element sealing sheet
(Preparation of wavelength conversion layer)
Wavelength conversion layer configuration by adding yellow phosphor (YAG) to a silicone elastomer solution (trade name “LR7665”, dimethylsiloxane skeleton derivative, manufactured by Asahi Kasei Wacker Co., Ltd.) to a particle concentration of 20% by weight and stirring for 1 hour. A solution was obtained. The obtained solution was applied to a commercially available polypropylene film (thickness 50 μm) to a thickness of 100 μm and dried at 80 ° C. for 10 minutes to obtain a wavelength conversion layer laminated on the separator.

(Preparation of sealing resin layer)
To a mixture of 200 g (17.4 mmol) of silanol-type silico oil at both ends, 1.75 g (11.8 mmol) of vinyl (trimethoxy) silane and 20 mL of 2-propanol, 320 μL (0.35 mmol) of a 10% aqueous solution of tetramethylammonium hydroxide was added at room temperature. And stirred for 2 hours. To the obtained oil, 1.50 g of organohydrogenpolysiloxane and 105 μL of platinum carbonyl complex solution (platinum concentration 2% by weight) were added and mixed by stirring to obtain a sealing resin layer constituting solution.

(Semiconductor element sealing sheet)
On the wavelength conversion layer laminated on the separator, the sealing resin layer-constituting solution obtained above was applied to a thickness of 900 μm, and dried at 80 ° C. for 20 minutes to obtain a sheet (thickness excluding the separator 1000 μm ).

Examples 1-6 and Comparative Examples 1-4
Place the sheet for optical semiconductor element sealing obtained above on the substrate on which the blue LED chip (1 mm × 1 mm) is mounted in the center of a 2 cm × 3 cm metal substrate so that the sealing resin layer faces the substrate. The concave mold shown in Table 1 was arranged from above. At this time, the center of the mold bottom and the center of the chip were arranged so as to be aligned. Next, it was molded for 10 minutes at 150 ° C. and 0.1 MPa using a vacuum laminator (manufactured by Nichigo Morton). Then, take it out from the vacuum laminator, leave it until the sealing resin layer does not change its shape even at room temperature, peel the mold and separator in order, and perform post cure for 5 hours in a 150 ° C dryer, An optical semiconductor device was manufactured.

Reference example 1
A mold in which a dome-shaped recess (dome recess) having a diameter of 2.0 mm was filled with the sealing resin layer constituting solution used for the preparation of the optical semiconductor element sealing sheet was the same as in Example 1. The substrate was placed on the substrate so that the center of the bottom of the dome recess and the center of the chip were aligned, and molded for 10 minutes at 150 ° C. and 0.1 MPa using a vacuum laminator (manufactured by Nichigo Morton). Then, it was taken out from the vacuum laminator and allowed to stand until the shape of the sealing resin layer did not change even at room temperature, and then the mold was peeled off to obtain an LED chip sealed with the sealing resin layer.

  Next, after filling the wavelength conversion layer constituting solution used for the preparation of the optical semiconductor element sealing sheet into a mold formed with a dome-shaped recess (dome recess) of φ2.2mm, φ2.0mm in it Molds with dome-shaped protrusions were placed so that the centers of the molds were aligned, and molded using a vacuum laminator (manufactured by Nichigo Morton) for 10 minutes at 150 ° C and 0.1 MPa. . Then, take it out from the vacuum laminator, leave it until the wavelength conversion layer does not change its shape even at room temperature, peel off the mold, and φ2.0mm dome shape with a φ2.0mm dome shape inside The wavelength conversion layer was obtained.

  The obtained wavelength conversion layer was placed over the sealing resin layer of the LED chip to obtain an optical semiconductor device having a dome shape.

  About the obtained optical semiconductor device, the characteristic was evaluated according to the following test examples 1-2. The results are shown in Table 1.

Test example 1 (chromaticity angle dependence)
A current of 50 mA is applied to the optical semiconductor device, and the emitted light at each angle is detected using a spectrophotometer (MCPD-3000, manufactured by Otsuka Electronics Co., Ltd.), and the chromaticity is represented by the CIE chromaticity index (x, y). It was. Since the (x) and (y) values of chromaticity (x, y) by color mixture obtained from the same semiconductor material and wavelength conversion material have a one-to-one relationship, 0 ° (front) to 80 ° For the CIE chromaticity (y) value, the difference between the maximum value and the minimum value was calculated as the chromaticity difference, and the chromaticity angle dependency was evaluated according to the following evaluation criteria. Note that the smaller the chromaticity difference is, the smaller the chromaticity angle dependency is, and the chromaticity difference that can be identified by a general human eye is about 0.03.

<Evaluation criteria for chromaticity angle dependency>
○: Less than 0.030 chromaticity difference ×: More than 0.030 chromaticity difference

Test example 2 (wavelength conversion characteristics)
After mounting the optical semiconductor device on a copper heat sink, current of 1A was passed, the temperature of the package surface was measured using a thermographic device (CHINO, CPA1000), and wavelength conversion characteristics were evaluated according to the following evaluation criteria . In addition, when the surface temperature of a package exceeds 120 degreeC, since the wavelength conversion efficiency of fluorescent substance will fall, it shows that a wavelength conversion characteristic is inferior.

<Evaluation criteria for wavelength conversion characteristics>
○: Package surface temperature is less than 120 ℃ △: Package surface temperature is 120 ℃ or more

  As a result, it can be seen that the optical semiconductor device of the example has smaller chromaticity angle dependency than the comparative example, and can emit light with uniform chromaticity. Further, the optical semiconductor device of Reference Example 1 has small chromaticity angle dependency and can emit light with uniform chromaticity, but the device fabrication is complicated, whereas the optical semiconductor device of Example has light emission with uniform chromaticity. It is excellent that it can be obtained easily.

  The optical semiconductor device of the present invention has small chromaticity angle dependency, and can be suitably used for, for example, a backlight of a liquid crystal screen, a traffic light, a large outdoor display, an advertisement signboard, and the like.

1 Substrate 2 Molded body 3 Sealing resin layer 4 φ2.0 mm concave mold 5 Wavelength conversion layer 6 φ2.2 mm concave mold 7 φ2.0 mm convex mold

Claims (1)

A sheet for sealing an optical semiconductor element comprising a sealing resin layer in which an optical semiconductor element can be embedded and a wavelength conversion layer having a thickness of 50 to 200 μm containing optical wavelength conversion particles is directly or indirectly laminated. a method for manufacturing an optical semiconductor device in which the resin layer is molded using a concave mold disposed so as to face the optical semiconductor element mounting substrate, before Symbol concave mold, the area of the area and the side face of the concave portion of the concave portion bottom face of the total area, the recess bottom area of 40% or more, have a recess structure that satisfies the less than 60 percent, and, using a shape square or circular der Ru mold recess bottom, the resulting molded article cuboid Alternatively, a method for manufacturing an optical semiconductor device, which has a cylindrical shape, is formed such that a wavelength conversion layer is formed on the upper surface and side surfaces thereof, and the height of the molded body is 500 to 1500 μm .