JP2015118951A - Light-emitting device and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device that eliminates the need for a dedicated metal mold and can increase the degree of freedom of processing determining light distribution characteristics, and a method of manufacturing the same.SOLUTION: A light-emitting device includes: a printed wiring board 1; an LED chip 2 mounted on the printed wiring board 1; a translucent resin 3 covering the LED chip 2 and having a dome-shaped appearance including a phosphor 5; and a cavity 4 formed in the translucent resin 3 through laser irradiation. Consequently, emitted light of the LED chip 2 can be reflected and diffused by a surface defining the cavity 4, so the angle of light distribution can be widened. Further, the cavity 4 is formed through the laser irradiation, so no dedicated metal mold needs to be used, and the translucent resin 3 can be formed at an arbitrary position only by changing the focal length of the laser.

Description

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

  Conventionally, as a light emitting device, there is one disclosed in Japanese Patent Laid-Open No. 2008-187212 (Patent Document 1). In this light emitting device, the base and the light reflecting member formed on the base form a recess. In addition, a semiconductor light emitting element is disposed in the recess, and a translucent resin is formed around the semiconductor light emitting element. The upper surface of the translucent resin is covered with a fluorescent material-containing resin.

  In such a light emitting device, since the light emitted from the semiconductor light emitting element is reflected upward by the light reflecting member, the light distribution angle is narrow.

JP 2008-187212 A

  FIG. 8 is a schematic cross-sectional view of a wide light distribution angle type light emitting device.

  In the light-emitting device, a light-transmitting resin 803 having a funnel-shaped outer shape is formed on the base 801 without forming the light emitting member. The translucent resin 803 includes a phosphor 805 and is covered with a semiconductor light emitting element 802. As a result, the light emitted from the semiconductor light emitting element 802 is reflected and diffused by the concave surface on the upper surface of the translucent resin 803.

  Such a translucent resin 803 cannot be formed by simply dropping a liquid resin as a material of the translucent resin 803 on the base 801 and curing the liquid resin. Become.

  However, when the translucent resin 803 is formed using a dedicated mold, the change of the shape of the translucent resin 803 requires a change of the dedicated mold.

  That is, there is a problem that the light distribution characteristic cannot be changed unless another dedicated mold having a shape different from that of the dedicated mold is used.

  Therefore, an object of the present invention is to provide a light emitting device that can eliminate the need for a dedicated mold and increase the degree of freedom of processing for determining light distribution characteristics, and a method for manufacturing the same.

  Note that the light-emitting device of FIG. 8 is presented for convenience in order to clarify the problem of the present invention, and is not a known technique.

In order to solve the above problems, the light-emitting device of the present invention includes:
A substrate;
A semiconductor light emitting device mounted on the substrate;
A translucent resin that covers the semiconductor light emitting element and has a dome-like outer shape including a phosphor;
And a cavity formed by laser irradiation on the surface or inside of the translucent resin.

  According to the above configuration, by forming a cavity on the surface or inside of the translucent resin, the light emitted from the semiconductor light emitting element can be reflected and diffused on the surface defining the cavity, so that the light distribution angle can be widened. it can.

  In addition, since the cavity is formed by laser irradiation, it is not necessary to use a dedicated mold, and if the focal point of the laser is changed, it can be formed on the surface of the translucent resin and at any position inside. . Therefore, the dedicated mold can be dispensed with, and the degree of freedom in processing for determining light distribution characteristics can be increased.

  Moreover, since the said translucent resin contains fluorescent substance, the wavelength of the emitted light of a semiconductor light-emitting element can be converted into another wavelength with fluorescent substance. Therefore, the chromaticity of the light emitting device can be controlled.

  FIG. 4 is a schematic cross-sectional view of a light-emitting device for explaining the effects of the present invention. FIG. 5 is a chromaticity diagram of the light emitting device.

  As shown in FIG. 4, the light emitting device has a base 401, a semiconductor light emitting element 402 mounted on the base 401, a semiconductor light emitting element 402, and a phosphor 405 that has a hemispherical surface. Translucent resin 403.

  FIG. 6 is a schematic cross-sectional view of another light emitting device for explaining the function and effect of the present invention. FIG. 7 is a chromaticity diagram of the other light emitting device. In FIG. 6, the same components as those shown in FIG. 4 are denoted by the same reference numerals as those of the components shown in FIG.

  As shown in FIG. 6, the configuration of the other light emitting devices other than the light transmitting resin 603 is the same as the configuration of the light emitting device of FIG. The translucent resin 603 has a shape obtained by crushing the translucent resin 403.

  As is clear from the comparison between FIGS. 5 and 7, the chromaticity can be changed by changing the shape of the translucent resin.

  Therefore, since the light emitting device of the present invention can form cavities at any position inside and inside the translucent resin, the degree of freedom in controlling the chromaticity can be increased.

In the light emitting device of one embodiment,
The cavity is formed in the translucent resin.

  According to the embodiment, by forming a cavity in the translucent resin, the surface that defines the cavity (the surface that reflects and diffuses the emitted light of the semiconductor light emitting element) is damaged and contaminated in the manufacturing process, for example. Can increase the yield.

In the light emitting device of one embodiment,
The cross-sectional shape of the cavity is elliptical.

  According to the embodiment, since the cross-sectional shape of the cavity is an elliptical shape, the light distribution angle can be surely widened.

In the light emitting device of one embodiment,
The cavity is formed on the semiconductor light emitting device.

  According to the embodiment, since the cavity is formed on the semiconductor light emitting element, the light distribution angle can be surely widened.

The manufacturing method of the light emitting device of the present invention is as follows:
Mounting a semiconductor light emitting element on a substrate;
Forming a translucent resin containing a phosphor on the substrate so as to have a dome-shaped outer shape, and covering the semiconductor light emitting element with the translucent resin;
And a step of irradiating the translucent resin covering the semiconductor light emitting element with a laser to form a cavity in the surface or inside of the translucent resin.

  According to the above configuration, the light emitted from the semiconductor light emitting element can be reflected and diffused on the surface defining the cavity by forming the cavity on the surface or inside of the translucent resin. The light angle can be widened.

  In addition, since the cavity is formed by laser irradiation, it is not necessary to use a dedicated mold, and if the focal point of the laser is changed, it can be formed on the surface of the translucent resin and at any position inside. . Therefore, the dedicated mold can be dispensed with, and the degree of freedom in processing for determining light distribution characteristics can be increased.

  Moreover, since the said translucent resin contains fluorescent substance, the wavelength of the emitted light of a semiconductor light-emitting element can be converted into another wavelength with fluorescent substance. Therefore, the chromaticity of the light emitting device can be controlled.

  Moreover, since a cavity can be formed in the surface of the said translucent resin and arbitrary positions inside, the freedom degree of control of chromaticity can be enlarged.

  According to the light-emitting device of the present invention, a base, a semiconductor light-emitting element mounted on the base, a translucent resin that covers the semiconductor light-emitting element and includes a phosphor and has a dome-shaped outer shape, By providing a cavity formed by laser irradiation on or inside the translucent resin, the light emitted from the semiconductor light emitting element can be reflected and diffused on the surface defining the cavity, so that the light distribution angle can be widened. .

  In addition, since the cavity is formed by laser irradiation, it is not necessary to use a dedicated mold, and if the focal point of the laser is changed, it can be formed on the surface of the translucent resin and at any position inside. . Therefore, the dedicated mold can be dispensed with, and the degree of freedom in processing for determining light distribution characteristics can be increased.

  Moreover, since the said translucent resin contains fluorescent substance, the wavelength of the emitted light of a semiconductor light-emitting element can be converted into another wavelength with fluorescent substance. Therefore, the chromaticity of the light emitting device can be controlled.

  Moreover, since the said cavity can be formed in the surface of a translucent resin, and arbitrary positions inside, the freedom degree of control of chromaticity can be enlarged.

  A method for manufacturing a light-emitting device according to the present invention includes a step of mounting a semiconductor light-emitting element on a substrate, and forming a translucent resin containing a phosphor on the substrate so as to have a dome-shaped outer shape. A step of covering the light-emitting element with a translucent resin, and a step of irradiating the translucent resin covering the semiconductor light-emitting element with a laser to form a cavity in or on the surface of the translucent resin. Since the light emitted from the semiconductor light emitting device can be reflected and diffused on the surface defining the cavity, the light distribution angle can be widened.

  In addition, since the cavity is formed by laser irradiation, it is not necessary to use a dedicated mold, and if the focal point of the laser is changed, it can be formed on the surface of the translucent resin and at any position inside. . Therefore, the dedicated mold can be dispensed with, and the degree of freedom in processing for determining light distribution characteristics can be increased.

  Moreover, since the said translucent resin contains fluorescent substance, the wavelength of the emitted light of a semiconductor light-emitting element can be converted into another wavelength with fluorescent substance. Therefore, the chromaticity of the light emitting device can be controlled.

  Moreover, since a cavity can be formed in the surface of the said translucent resin and arbitrary positions inside, the freedom degree of control of chromaticity can be enlarged.

FIG. 1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the LED chip of the light emitting device. FIG. 3A is a process diagram of the method for manufacturing the light-emitting device. FIG. 3B is a process diagram of the manufacturing method of the light-emitting device following FIG. 3A. FIG. 3C is a process diagram of the manufacturing method of the light-emitting device following FIG. 3B. FIG. 4 is a schematic cross-sectional view of a light-emitting device for explaining the effects of the present invention. FIG. 5 is a chromaticity diagram of the light emitting device of FIG. FIG. 6 is a schematic cross-sectional view of another light emitting device for explaining the function and effect of the present invention. FIG. 7 is a chromaticity diagram of the light emitting device of FIG. FIG. 8 is a schematic cross-sectional view of a light-emitting device for explaining the problem of the present invention.

  Hereinafter, the light-emitting device of the present invention will be described in detail with reference to the illustrated embodiments.

  FIG. 1 is a schematic cross-sectional view of a light emitting device according to an embodiment of the present invention.

  The light emitting device includes a printed wiring board 1, an LED (light emitting diode) chip 2 mounted on the printed wiring board 1, a translucent resin 3 covering and sealing the LED chip 2, and the translucent light. And a cavity 4 formed by laser irradiation inside the functional resin 3. The printed wiring board 1 is an example of a base, and the LED chip 2 is an example of a semiconductor light emitting element.

  The printed wiring board 1 includes a substrate body 11 made of an insulating material, a first electrode pattern 12 provided on the left side portion of the substrate body 11, and a second electrode pattern 13 provided on the right side portion of the substrate body 11. have. The first electrode pattern 12 is provided over the left side portion of the upper surface of the substrate body 11, the left side surface of the substrate body 11, and the left side portion of the lower surface of the substrate body 11, and metal bumps (not shown). ) To the P-type pad electrode 26 (see FIG. 2) below the LED chip 2. On the other hand, the second electrode pattern 13 is provided across the right side portion of the upper surface of the substrate body 11, the right side surface of the substrate body 11, and the right portion of the lower surface of the substrate body 11. It is connected to an N-type pad electrode 25 (see FIG. 2) below the LED chip 2 via a not-shown).

The translucent resin 3 is mainly made of a transparent resin such as silicon. The translucent resin 3 is formed so as to cover the LED chip 2 and a part of each of the first electrode pattern 12 and the second electrode pattern 13 and have a dome-like outer shape. The translucent resin 3 includes a phosphor 5 that converts the wavelength of the emitted light of the LED chip 2 into another wavelength. As the phosphor 5, a red phosphor (for example, La ₂ O ₂ S: Eu, 0.5MgF ₂ .3.5MgO.GeO ₂ : Mn, CaS: Eu, Tm), a green phosphor (for example, SrAl ₂ O _4). : Eu), blue phosphor (eg (Sr, Ca, Ba, Ce) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, BaMg ₂ Al ₁₆ O ₂₇ : Eu), blue green phosphor (eg Sr ₄ Al ₁₄ O ₂₅ : Eu, Sr ₄ Al ₁₄ O ₂₅ : Eu, Dy) or the like can be used.

  The cavity 4 is formed on the LED chip 2. In other words, the cavity 4 overlaps the LED chip 2 in the vertical direction. The length of the cavity 4 in the left-right direction (the direction parallel to the upper surface of the printed wiring board 1) is substantially the same as the length of the LED chip 2 in the left-right direction. The cross-sectional shape of the cavity 4 is elliptical.

  FIG. 2 is a schematic sectional view of the LED chip 2.

  The LED chip 2 is an example of a type of LED chip 2 that extracts light through a substrate. More specifically, the LED chip 2 has an N-type gallium nitride compound semiconductor layer 22, a P-type gallium nitride compound semiconductor layer 23, an insulating sapphire substrate 21 (below the sapphire substrate 21 in FIG. 2), A P-type layer electrode 24 made of a metal thin film or a transparent conductive film is sequentially laminated to form an N-type pad electrode 25 on the exposed surface of the N-type gallium nitride compound semiconductor layer 22, and the P-type layer electrode 24. A P-type pad electrode 26 is formed on the surface. When a potential difference is applied between the N-type pad electrode 25 and the P-type pad electrode 26 (current flows and emits light), light is emitted from the light emitting region 20, and this light is transmitted through the sapphire substrate 21. The light is emitted upward (in the direction opposite to the N-type gallium nitride compound semiconductor layer 22 side).

  Hereinafter, the manufacturing method of the light-emitting device will be described with reference to FIGS. 3A to 3C.

  First, the P-type pad electrode 26 of the LED chip 2 is connected to the first electrode pattern 12 via a metal bump (for example, Au bump), and the N-type pad electrode 25 of the LED chip 2 is connected to the metal bump ( For example, the LED chip 2 is mounted on the printed wiring board 1 as shown in FIG. 3A by being connected to the second electrode pattern 13 via Au bumps).

  Next, a liquid resin, which is a material of the translucent resin 3, mixed with the phosphor 5 is dropped on the LED chip 2, and then a curing process is performed. As shown in FIG. A translucent resin 31 having the outer shape is formed, and the LED chip 2 is covered with the translucent resin 31. Here, the curing treatment is a heat treatment if the liquid resin is a thermosetting resin, and an ultraviolet irradiation treatment if the liquid resin is an ultraviolet curable resin. That is, the said hardening process becomes a process according to the property of the said liquid resin.

  Next, the light-transmitting resin 31 covering the LED chip 2 is irradiated with laser to form a cavity 4 located on the LED chip 2 inside the light-transmitting resin 3 as shown in FIG. 3C. The surface defining this cavity is melted by the heat of laser irradiation and becomes a smooth surface.

  Thus, by forming the cavity 4 inside the translucent resin 3, the light emitted from the LED chip 2 can be reflected and diffused on the surface defining the cavity 4 as shown by the arrows in FIG. Become. Therefore, the light distribution angle of the light emitting device can be widened.

  Further, since the cavity 4 is formed by laser irradiation, it is not necessary to use a dedicated mold, and the cavity 4 can be formed at any position inside the translucent resin 3 by changing the focal point of the laser. . Therefore, the dedicated mold can be dispensed with and the degree of freedom in processing for determining the light distribution characteristics is great.

  Moreover, since the said translucent resin 3 contains the fluorescent substance 5, the wavelength of the emitted light of the LED chip 2 can be converted into another wavelength by the fluorescent substance 5. Therefore, the chromaticity of the light emitting device can be controlled.

  Further, since the cavity 4 can be formed at an arbitrary position inside the translucent resin 3, the degree of freedom in controlling the chromaticity is great.

  Further, by forming the cavity 4 inside the translucent resin 3, the surface that defines the cavity 4 (the surface that reflects and diffuses the emitted light of the LED chip 2) is damaged and contaminated in the manufacturing process. It can prevent and increase the yield.

  Moreover, since the cross-sectional shape of the cavity 4 is an elliptical shape, the light distribution angle can be surely widened.

  Moreover, since the cavity 4 is formed on the LED chip 2, the light distribution angle can be surely widened.

  In the above embodiment, one cavity 4 is formed inside the translucent resin 3, but two or more cavities 4 may be formed inside the translucent resin 3.

  In the above embodiment, the cavity 4 having an elliptical cross section is formed inside the translucent resin 3, but a cavity having another shape (for example, a circle or a square) may be formed. In this case, the number of the cavities may be singular or plural.

  In the said embodiment, although the translucent resin 3 by which the cavity 4 was formed in the inside by laser irradiation was used, you may use the translucent resin by which the surface or single cavity was formed in the surface by laser irradiation. That is, one or more recesses may be formed on the surface of the translucent resin by laser irradiation.

  In the above embodiment, the P-type pad electrode 26 and the N-type pad electrode 25 of the LED chip 2 are directed to the printed wiring board 1 side. However, the P-type pad electrode 26 and the N-type pad electrode of the LED chip 2 are used. 25 may be directed to the side opposite to the printed wiring board 1 side. In this case, the P-type pad electrode 26 of the LED chip 2 is connected to the first electrode pattern 12 via a metal wire, and the N-type pad electrode 25 of the LED chip 2 is connected via a metal wire. The second electrode pattern 13 may be connected.

  In the above embodiment, the LED chip 2 has the sapphire substrate 21, but may have a substrate made of another material such as ZnO, GaN, SiC, ZnSe or the like.

  In the above embodiment, the material of the semiconductor layer in the LED chip 2 is preferably a nitride compound semiconductor (InxGayAlzN (x + y + z = 1, 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, 0 ≦ z ≦ 1)). Other semiconductors such as SiC and ZnSe may be used.

  In the above embodiment, the light emitted from the LED chip 2 may fall within a wavelength range of 390 nm to 420 nm.

  In the said embodiment, if it is resin transparent to the light which LED chip 2 radiate | emits, and transparent to the light wavelength-converted with the fluorescent substance 5, it can be used as the translucent resin 3.

DESCRIPTION OF SYMBOLS 1 ... Printed circuit board 2 ... LED chip 3,31 ... Translucent resin 4 ... Cavity 5 ... Phosphor 20 ... Light emitting region 21 ... Sapphire substrate 22 ... N-type gallium nitride compound semiconductor layer 23 ... P-type gallium nitride compound Semiconductor layer 24 ... P-type layer electrode 25 ... N-type pad electrode 26 ... P-type pad electrode

Claims (5)

A substrate;
A semiconductor light emitting device mounted on the substrate;
A translucent resin that covers the semiconductor light emitting element and has a dome-like outer shape including a phosphor;
A light emitting device comprising: a cavity formed by laser irradiation on or inside the translucent resin. The light-emitting device according to claim 1.
The light emitting device, wherein the cavity is formed in the translucent resin. The light-emitting device according to claim 1,
A light-emitting device, wherein the cross-sectional shape of the cavity is elliptical. The light emitting device according to any one of claims 1 to 3,
The light emitting device, wherein the cavity is formed on the semiconductor light emitting element. Mounting a semiconductor light emitting element on a substrate;
Forming a translucent resin containing a phosphor on the substrate so as to have a dome-shaped outer shape, and covering the semiconductor light emitting element with the translucent resin;
And a step of irradiating the translucent resin covering the semiconductor light emitting element with a laser to form a cavity in the surface or inside of the translucent resin.

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