JP7476002B2 - Light-emitting device - Google Patents

Description

The present invention relates to a light-emitting device having multiple LED (light-emitting diode) elements.

LED elements, which are semiconductor elements, have a long lifespan and excellent driving characteristics, and are also small in size, have good luminous efficiency, and emit bright light, so they have been widely used in lighting and other applications in recent years.

An LED array light source has been disclosed in which adjacent LED lamps are divided into individual segments by partitions, the inside of the segments are hardened with molding resin, and a complementary color absorption layer for the LED emission wavelength is provided at the contact surface between the partitions and the molding resin (see Patent Document 1).

Japanese Utility Model Application Publication No. 1-123368

Figure 12(a) is a plan view showing an example of a conventional light-emitting device 90, and Figure 12(b) is a cross-sectional view taken along line IB-IB in Figure 12(a), showing the portion corresponding to the dotted area in Figure 12(a).

The light emitting device 90 has an LED element 91, a resin frame 92, and a sealing resin 93. The light emitting device 90 emits white light obtained by mixing blue light from the LED element 91, which is a blue LED, and yellow light obtained by exciting a yellow phosphor contained in the sealing resin 93 with the blue light. When a yellow phosphor is used, if the blue light emitted from the LED element 91 passes through the sealing resin 93 for a long time, the probability that the light will irradiate the yellow phosphor increases, and the light emitted from the light emitting device 90 becomes yellower. The light L1 emitted obliquely from the LED element 91 passes through the sealing resin 93 for a long time compared to the light L2 emitted vertically from the upper surface of the LED element 91. When the light L1 emitted obliquely from the LED element 91 is emitted to the outside of the light emitting device 90 from the vicinity of the resin frame 92, a yellow ring-shaped light (hereinafter sometimes referred to as a yellow ring) is generated around the white light. The occurrence of the yellow ring impairs the uniformity of the color of the light emitted from the light emitting device 90.

Therefore, the present invention aims to provide a light-emitting device that can suppress the occurrence of yellow rings.

A light-emitting device is provided that has a substrate, a light-emitting element mounted on the substrate, a holding material arranged around the light-emitting element on the substrate, and a sealant filled inside the holding material to seal the light-emitting element, the sealant containing a fluorescent material that converts the wavelength of light emitted from the light-emitting element and emits the converted light, and the holding material containing a pigment whose absorption band of the absorption spectrum includes the peak wavelength of the light emitted by the fluorescent material and whose absorption band of the absorption spectrum does not include the peak wavelength of the light emitted by the light-emitting element.

In the above light emitting device, it is preferable that the retaining material contains a resin and a pigment, and the pigment is dispersed throughout the retaining material.

In the above light-emitting device, it is preferable that the retaining material includes a first portion that contains a resin and a pigment, and a second portion that does not contain a pigment, contains a resin and a reflective material, and is disposed inside the first portion.

In the above light emitting device, it is preferable that the second part has a reflective surface whose height from the substrate gradually decreases from the outside where the first part is located to the inside where the light emitting element is mounted.

In the above light-emitting device, it is preferable that the retaining material includes a first portion that contains a resin and a pigment, and a second portion that does not contain a pigment, contains a resin and a reflective material, and is disposed inside and outside the first portion.

In the above light emitting device, it is preferable that the first portion has a flat portion at the top.

In the above light emitting device, it is preferable that the upper surface of the sealing material is located at the same height as the top of the second portion.

In the above light emitting device, it is preferable that the upper surface of the sealing material is located at the same height as the flat portion.

In the above light emitting device, it is preferable that the light emitted from the fluorescent material has a yellow color and the pigment has a blue color.

The present invention makes it possible to realize a light-emitting device that can suppress the occurrence of yellow rings.

1A and 1B are a plan view and a cross-sectional view of a light emitting device 1. FIG. Graphs (a) and (b) show absorption spectra and the like. 4A to 4D are schematic diagrams illustrating a method for manufacturing the light emitting device 1. 2A and 2B are a plan view and a cross-sectional view of the light emitting device 2. FIG. 4A to 4E are schematic diagrams illustrating a method for manufacturing the light emitting device 2. 1A and 1B are a plan view and a cross-sectional view of a light-emitting device 3. 4A to 4E are schematic diagrams illustrating a method for manufacturing the light emitting device 3. 4A and 4B are a plan view and a cross-sectional view of the light emitting device 4. FIG. 4A to 4E are schematic diagrams illustrating a method for manufacturing the light emitting device 4. 1A and 1B are a plan view and a cross-sectional view of a light-emitting device 5. 4A to 4E are schematic diagrams illustrating a method for manufacturing the light emitting device 5. 1A and 1B are a plan view and a cross-sectional view of a light emitting device 90. FIG.

The light emitting device will now be described with reference to the drawings. However, it should be understood that the present invention is not limited to the drawings or the embodiments described below.

First Embodiment
FIG. 1A is a plan view of a light emitting device 1 according to a first embodiment as viewed from above, and FIG. 1B is a cross-sectional view taken along the line AA' in FIG.

The light-emitting device 1 has as its main components a mounting substrate 10, a circuit board 15, a plurality of LED elements 30, a dam material 40, and a sealing material 50. The light-emitting device 1 is used as an LED light source for light source devices such as floodlights, high ceiling lighting, and stadium lighting/illumination, and emits white light.

In FIG. 1(b), only the elements in the cross section are shown, and elements behind the cross section are omitted to make the illustration easier to understand. In addition, the top layer of the light-emitting device 1 is a translucent sealing material 50 that contains phosphor particles, but for convenience, the lower layer is shown in solid lines in FIG. 1(a) as if the upper and lower layers are observable. The dam material 40 is also opaque, but is shown in FIG. 1(a) as translucent.

As shown in FIG. 1, the mounting substrate 10 is a flat aluminum substrate on which a plurality of LED elements 30 are mounted, and has a square shape as an example. The mounting substrate 10 may be a ceramic substrate. A high-reflection treatment layer (reflective layer) such as a silver layer (not shown) is formed on the upper surface of the mounting substrate 10. The reflective layer may be a reflection-enhancing film such as a dielectric multilayer film. Through holes for fixing the light-emitting device 1 may be provided near two diagonal corners different from the two diagonal vertices where the first terminal electrode 21 and the second terminal electrode 23 are provided.

A circuit board 15 having a circular opening 16 is attached to the upper surface of the mounting substrate 10 by adhesive. The circuit board 15 is an insulating board made of a glass epoxy material. A wiring pattern is formed on the upper surface of the circuit board 15. The wiring pattern includes a first electrode 20 having an arc shape, a first terminal electrode 21 electrically connected to the first electrode 20, a second electrode 22 having an arc shape, and a second terminal electrode 23 electrically connected to the second electrode 22. The wiring pattern is formed, for example, by plating nickel and gold on copper.

The first terminal electrode 21 and the second terminal electrode 23 are formed near two diagonally opposite vertices of the mounting substrate 10. The first terminal electrode 21 is a cathode (negative) electrode, and the second terminal electrode 23 is an anode (positive) electrode. When a voltage is applied to these from an external power source, electricity is passed through the LED element 30, causing the light emitting device 1 to emit light. Note that reference numerals 24 and 25 near the first terminal electrode 21 and the second terminal electrode 23 are patterns indicating the polarity of the first terminal electrode 21 and the second terminal electrode 23, and although they are not wiring patterns, they are formed from the same gold plating layer as the wiring pattern.

The upper surface of the circuit board 15, except for the surfaces of the first terminal electrode 21, the second terminal electrode 23, and the polarity patterns 24 and 25, is covered with a solder mask (not shown) to prevent short circuits between the first terminal electrode 21 and the second terminal electrode 23, etc.

The multiple LED elements 30 mounted on the mounting substrate 10 are connected to each other with gold bonding wires (hereinafter simply referred to as wires) 32, and are also connected to the first electrodes 20 and second electrodes 22 by wires. In the example of FIG. 1, the LED elements 30 are connected between the first electrodes 20 and the second electrodes 22 in five parallel rows of five elements each, but the number of LED elements in series and the number of parallel rows are arbitrary and may be other numbers.

The LED element 30 is an example of a light-emitting element, and is, for example, a blue LED that emits blue light with an emission wavelength band of about 450 to 460 nm. As described above, in the light-emitting device 1, multiple (5 x 5 = 25) LED elements 30 are mounted on the mounting substrate 10, and these emit blue light of the same wavelength.

The LED element 30 has a pair of element electrodes on the upper surface. As shown in FIG. 1, the element electrodes of adjacent LED elements 30 are connected in series by wires 32, and the element electrodes of the LED elements 30 at both ends are connected to the first electrode 20 or the second electrode 22 by wires 32. The lower surface of the LED element 30 is directly fixed to the upper surface of the mounting substrate 10 inside the opening 16 of the circuit board 15 by, for example, a transparent insulating adhesive (die bond). The LED element 30 is directly fixed onto a reflective layer formed on the aluminum mounting substrate 10, so it has a high heat dissipation effect and can emit high-power light.

The component indicated by reference number 31 is a Zener diode element that protects the LED element 30 when an overvoltage is applied between the first electrode 20 and the second electrode 22.

The dam material 40 is an example of a holding material, and is a circular (toroidal, doughnut-shaped) frame that is arranged around the LED elements 30 on the mounting substrate 10 and absorbs light. The dam material 40 is formed at a position that overlaps with the first electrode 20, the second electrode 22, and the Zener diode elements 31 on the circuit substrate 15, covering them and surrounding the multiple LED elements 30.

The dam material 40 contains a silicone resin and a predetermined pigment. The predetermined pigment is a pigment whose absorption band includes the peak wavelength of the light emitted by the phosphor contained in the sealing material 50, and whose absorption band does not include the peak wavelength of the light emitted by the LED element 30. The absorption spectrum is the spectrum of light absorbed by an object for a standard light source, and the absorption band is a portion in which a certain range of the absorption spectrum shows continuous absorption. The absorption band is, for example, a wavelength band in which the absorption rate is a predetermined ratio (for example, 60%) or more. That is, this pigment has a complementary color to the color of the light emitted from the phosphor after wavelength conversion by the phosphor. In the light emitting device 1, the light emitted from the phosphor has a yellow color, the light emitted from the LED element 30 has a blue color, and the pigment has a blue color. For example, ultramarine or cobalt blue is used as such a pigment. Note that the pigment may have a color other than blue as long as it is a complementary color to the color of the light emitted from the phosphor.

The pigment is dispersed throughout the dam material 40. The dam material 40 reflects the blue light emitted laterally from each LED element 30 upward (the opposite side of the mounting substrate 10 as viewed from each LED element 30) of the light emitting device 1, while absorbing the light emitted laterally from each LED element 30 and wavelength-converted by the phosphor contained in the sealing material 50. In the light emitting device 1, the light emitted from the multiple LED elements 30 is reflected upward by the reflective layer of the mounting substrate 10 and the dam material 40, so that the emission efficiency is high. On the other hand, in the light emitting device 1, the light emitted from each LED element 30 and wavelength-converted by the phosphor contained in the sealing material 50 is absorbed by the dam material 40, so that the occurrence of yellow rings is suppressed, and it is possible to maintain a uniform color of the light emitted from the light emitting device 1. Note that the dam material 40 is arranged in a circular shape in a plan view as shown in FIG. 1, but may be arranged in an elliptical shape. In addition, the dam material 40 may be formed of a metal material having the same color as the above-mentioned pigment, or a metal material surface-treated with the above-mentioned pigment.

The sealing material 50 is injected (filled) inside the dam material 40 arranged on the circuit board 15, i.e., the area surrounded by the dam material 40, and hardens into a roughly disk shape, integrally covering and protecting (sealing) the multiple LED elements 30. The upper surface of the sealing material 50 is located at the same height as the top of the dam material 40. That is, at least a portion of the dam material 40 is in contact with the sealing material 50, and the dam material 40 contains the above-mentioned pigment on the surface in contact with the sealing material 50. Silicone resin is used as the sealing material 50, but other resins that are colorless, transparent, and heat resistant to about 250°C can also be used.

The sealing material 50 contains a phosphor that converts the wavelength of the light emitted from each LED element 30. The phosphor is an example of a fluorescent material, and converts the wavelength of the light emitted from the LED element 30 before emitting it. The sealing material 50 contains a yellow phosphor such as YAG (yttrium aluminum garnet) as such a phosphor. The light emitting device 1 emits white light obtained by mixing the blue light from the LED element 30, which is a blue LED, with the yellow light obtained by exciting the yellow phosphor with the blue light. The yellow phosphor described above is an example, and the sealing material 50 can also contain other phosphors.

In the light emitting device 1, the filling rate of the LED elements 30 is high, so the amount of heat generated per unit area of the light emitting area (inside the dam material 40) is also high. When the spacing between the LED elements narrows and the light density increases, the density of the light hitting the phosphor contained in the sealing material 50 also increases, and the phosphor itself generates heat. Therefore, in the light emitting device 1, the phosphor in the sealing material 50 is allowed to settle and brought closer to the mounting substrate 10, thereby improving the heat dissipation properties of the phosphor itself and making it easier to dissipate heat.

Figures 2(a) and (b) are graphs that show the spectrum of light from the LED element 30 and the phosphor, and the absorption spectrum of the dam material.

The horizontal axis of Fig. 2(a) and (b) indicates the wavelength (nm), with the wavelength increasing toward the right. The vertical axis of Fig. 2(a) and (b) indicates the relative radiant intensity of light for the spectrum of light from the LED element 30 and the phosphor, with the intensity increasing toward the top. The vertical axis of Fig. 2(a) and (b) indicates the absorptance for the absorption spectrum of the dam material, with the absorptance increasing toward the top.

Graph 201 in FIG. 2(a) shows the spectrum of light emitted from the LED element 30 and the phosphor. In this spectrum, there are intensity peaks near the peak wavelength λ1 of the blue light emitted by the LED element 30 and the peak wavelength λ2 of the yellow light wavelength-converted by the phosphor. Graph 202 shows the absorption spectrum of the dam material using ultramarine as a pigment. In this absorption spectrum, the absorption rate at the peak wavelength λ2 of the light wavelength-converted by the phosphor is about 1.0, and the absorption rate at the peak wavelength λ1 of the light emitted by the LED element 30 is about 0.5. That is, the peak wavelength λ2 of the light wavelength-converted by the phosphor is included in the absorption band of ultramarine, and the light wavelength-converted by the phosphor is almost absorbed by the dam material using ultramarine as a pigment. On the other hand, the peak wavelength λ1 of the light emitted by the LED element 30 is not included in the absorption band of ultramarine, and the light emitted by the LED element 30 is reflected by the dam material using ultramarine as a pigment.

Graph 211 in FIG. 2(b) shows a spectrum of light similar to that of graph 201 in FIG. 2(a). Graph 212 shows the absorption spectrum of a dam material using cobalt blue as a pigment. In this absorption spectrum, the absorption rate at the peak wavelength λ2 of the light wavelength-converted by the phosphor is about 0.9, and the absorption rate at the peak wavelength λ1 of the light emitted by the LED element 30 is about 0.4. That is, the peak wavelength λ2 of the light wavelength-converted by the phosphor is included in the absorption band of cobalt blue, and the light wavelength-converted by the phosphor is almost absorbed by the dam material using cobalt blue as a pigment. On the other hand, the peak wavelength λ1 of the light emitted by the LED element 30 is not included in the absorption band of cobalt blue, and the light emitted by the LED element 30 is reflected by the dam material using cobalt blue as a pigment.

In the light emitting device 1, a dam material 40 having a complementary color to the color of the light whose wavelength is converted by the phosphor is disposed around the LED element 30 and the sealing material 50. As a result, in the light emitting device 1, the light emitted obliquely from the LED element 30 is well reflected by the dam material 40 and emitted, while the light emitted obliquely from the LED element 30 and whose wavelength is converted by the phosphor is absorbed by the dam material 40, thereby suppressing the occurrence of a yellow ring.

Figures 3(a) to 3(d) are schematic diagrams illustrating a method for manufacturing the light-emitting device 1. The method for manufacturing the light-emitting device 1 will be described below with reference to Figure 3.

First, the mounting substrate 10 and the circuit board 15 on which various wiring patterns are formed are prepared, the mounting substrate 10 and the circuit board 15 are bonded together with an adhesive, and the first electrode 20 and the second electrode 22 are mounted on the upper surface of the circuit board 15. Figure 3(a) shows the state in which the mounting substrate 10 and the circuit board 15 are bonded together.

Next, inside the opening 16 of the circuit board 15, multiple LED elements 30 are mounted on the top surface of the mounting substrate 10, and wires are used to connect the LED elements 30 to each other, and between the LED elements 30 and the first electrode 20 and the second electrode 22. Figure 3(b) shows the state in which the LED elements 30 are mounted on the top surface of the mounting substrate 10 and connected by wires.

Next, uncured dam material resin is filled from a specified supply nozzle (not shown) and heated so as to draw a circle around the multiple LED elements 30 and cover the first electrode 20 and the second electrode 22, forming the dam material 40. Figure 3(c) is an image of a cross section of the dam material 40 when it is formed on the first electrode 20 and the second electrode 22.

Next, uncured encapsulant resin is filled inside the dam material 40 from a specified supply nozzle (not shown) up to the height of the apex of the dam material 40 and heated to form the encapsulant 50, completing the light emitting device 1. Figure 3(d) is an image of a cross section of the encapsulant 50 when it is formed.

Second Embodiment
FIG. 4A is a plan view of the light emitting device 2 according to the second embodiment as viewed from above, and FIG. 4B is a cross-sectional view taken along the line AA' in FIG. 4A.

The light emitting device 2 has, as its main components, a mounting substrate 10, a circuit board 15, a plurality of LED elements 30, a dam material 41, and a sealing material 51. The configurations of the mounting substrate 10, the circuit board 15, and the plurality of LED elements 30 are similar to the configurations of the mounting substrate 10, the circuit board 15, and the plurality of LED elements 30 of the light emitting device 1.

The dam material 41 is an example of a holding material, and includes a first portion 41a and a second portion 41b. The first portion 41a, like the dam material 40, is disposed around the LED element 30 on the mounting substrate 10 and is a ring-shaped frame that absorbs light. The second portion 41b is disposed inside the first portion 41a, and the top of the second portion 41b is located below the top of the first portion 41a (on the mounting substrate 10).

The first portion 41a contains a silicone resin and a specified pigment. This pigment is the same as the pigment contained in the dam material 40. The first portion 41a may be formed of a metal material having the same color as the pigment, or a metal material that has been surface-treated with the pigment. On the other hand, the second portion 41b does not contain this pigment, and is made of a reflective white resin that contains a silicone resin and a reflective material such as titanium oxide (or silica).

The second portion 41b reflects the blue light emitted laterally from each LED element 30 and the light emitted laterally from each LED element 30 and wavelength-converted by the phosphor contained in the sealing material 51 upward from the light-emitting device 2. On the other hand, the above-mentioned pigment is dispersed throughout the first portion 41a. The first portion 41a reflects the blue light emitted laterally from each LED element 30 upward from the light-emitting device 2, while absorbing the light emitted laterally from each LED element 30 and wavelength-converted by the phosphor contained in the sealing material 51. In the light-emitting device 2, the light emitted from the LED element 30 and the phosphor is reflected upward by the second portion 41b, so that the emission efficiency is higher than that of the light-emitting device 1. On the other hand, in the light-emitting device 2, the light wavelength-converted by the phosphor is absorbed by the first portion 41a, so that the occurrence of a yellow ring is suppressed and the color of the light emitted from the light-emitting device 2 can be kept uniform.

Similar to the sealing material 50, the sealing material 51 is injected (filled) inside the dam material 41 arranged on the circuit board 15, i.e., the area surrounded by the dam material 41, and hardened into a roughly disk shape, integrally covering and protecting (sealing) the multiple LED elements 30. The upper surface of the sealing material 51 is located at the same height as the top of the first portion 41a of the dam material 41. That is, at least a portion of the first portion 41a of the dam material 41 is in contact with the sealing material 51, and the dam material 41 contains the above-mentioned pigment on the surface in contact with the sealing material 51. The sealing material 51 is formed of the same material as the sealing material 50.

Figures 5(a) to 5(e) are schematic diagrams illustrating a method for manufacturing the light-emitting device 2. The method for manufacturing the light-emitting device 2 will be described below with reference to Figure 5.

The manufacturing procedure shown in Figures 5(a) and 5(b) is the same as that shown in Figures 3(a) and 3(b). After the LED elements 30 are mounted on the upper surface of the mounting substrate 10, uncured resin for the second portion is filled from a specified supply nozzle and heated so as to draw a circle around the multiple LED elements 30 and cover the first electrode 20 and the second electrode 22, forming the second portion 41b of the dam material 41. Figure 5(c) is an image of a cross section when the second portion 41b is formed on the first electrode 20 and the second electrode 22.

Next, uncured resin for the first portion is filled from a specified supply nozzle onto the outside of the second portion 41b so as to cover a part of the second portion 41b, and is heated to form the first portion 41a of the dam material 41. Figure 5(d) is an image of a cross section when the first portion 41a is formed outside the second portion 41b.

Next, uncured sealing resin is filled from a specified supply nozzle into the inside of the dam material 41 up to the height of the apex of the first portion 41a and heated to form the sealing material 51, completing the light emitting device 2. Figure 5(e) is an image of a cross section of the sealing material 51 when it is formed.

Third Embodiment
FIG. 6A is a plan view of a light emitting device 3 according to the third embodiment as viewed from above, and FIG. 6B is a cross-sectional view taken along the line AA' in FIG. 6A.

The light emitting device 3 has, as its main components, a mounting substrate 10, a circuit board 15, a plurality of LED elements 30, a dam material 41, and a sealing material 52. The configurations of the mounting substrate 10, the circuit board 15, the plurality of LED elements 30, and the dam material 41 are similar to the configurations of the mounting substrate 10, the circuit board 15, the plurality of LED elements 30, and the dam material 41 of the light emitting device 2.

Similar to sealing material 51, sealing material 52 is injected (filled) inside dam material 41 arranged on circuit board 15, i.e., the area surrounded by dam material 41, and hardened into a roughly disk shape, integrally covering and protecting (sealing) the multiple LED elements 30. Sealing material 52 is injected inside second portion 41b of dam material 41 and hardened into a roughly disk shape, with the upper surface of sealing material 52 positioned at the same height as the top of second portion 41b of dam material 41. Sealing material 52 is formed of the same material as sealing material 51.

Figures 7(a) to 7(e) are schematic diagrams illustrating a method for manufacturing the light-emitting device 3. The method for manufacturing the light-emitting device 3 will be described below with reference to Figure 7.

The manufacturing procedure shown in Figures 7(a) to 7(d) is the same as that shown in Figures 5(a) to 5(d). After the first portion 41a of the dam material 41 is formed outside the second portion 41b, uncured sealing resin is filled from a specified supply nozzle into the inside of the second portion 41b up to the height of the apex of the second portion 41b and heated to form the sealing material 52, completing the light emitting device 3. Figure 7(e) is an image of a cross section when the sealing material 52 is formed.

Fourth Embodiment
FIG. 8A is a plan view of a light emitting device 4 according to the fourth embodiment as viewed from above, and FIG. 8B is a cross-sectional view taken along the line AA' in FIG. 8A.

The light emitting device 4 has, as its main components, a mounting substrate 10, a circuit board 15, a plurality of LED elements 30, a dam material 43, and a sealing material 53. The configurations of the mounting substrate 10, the circuit board 15, and the plurality of LED elements 30 are similar to those of the mounting substrate 10, the circuit board 15, and the plurality of LED elements 30 of the light emitting device 1. Note that in FIG. 8(a), the elements located within the opening 16 of the circuit board 15 and the elements located below the dam material 43 are omitted from the illustration in order to make the illustration easier to understand.

The dam material 43 is an example of a holding material, and includes a first portion 43a and a second portion 43b. The first portion 43a is an annular frame that is arranged around the LED element 30 on the mounting board 10 and absorbs light, similar to the dam material 40. The second portion 43b is arranged inside and outside the first portion 43a. The first portion 43a is formed so that its cross section is L-shaped, has a flat portion 43d at its upper portion, and further has a base portion 43d that is arranged on the circuit board 15 and extends to the outer end of the flat portion 43c. The flat portion 43c formed at the upper portion of the first portion 43a protrudes from the top of the second portion 43b and is located at a position higher than the top of the second portion 43b.

The first portion 43a contains a molding resin and a specified pigment. This pigment is the same as the pigment contained in the dam material 40. The first portion 43a may be formed of a metal material having the same color as the pigment, or a metal material that has been surface-treated with the pigment. On the other hand, the second portion 43b does not contain this pigment, and is made of a reflective white resin that contains a silicone resin and a reflective material such as titanium oxide (or silica).

The portion of the second portion 43b arranged inside the first portion 43a reflects the blue light emitted laterally from each LED element 30 and the light emitted laterally from each LED element 30 and wavelength-converted by the phosphor contained in the sealing material 53 upwards of the light emitting device 4. On the other hand, the above-mentioned pigment is dispersed throughout the first portion 43a. The first portion 43a reflects the blue light emitted laterally from each LED element 30 upwards of the light emitting device 4, while absorbing the light emitted laterally from each LED element 30 and wavelength-converted by the phosphor contained in the sealing material 53. In the light emitting device 4, the light emitted from the LED element 30 and the phosphor is reflected upwards by the second portion 43b, so that the emission efficiency is higher than that of the light emitting device 1. On the other hand, in the light emitting device 4, the light wavelength-converted by the phosphor is absorbed by the first portion 43a, so that the occurrence of a yellow ring is suppressed, and it is possible to maintain the color of the light emitted from the light emitting device 4 uniform.

In addition, in the light-emitting device 4, the first portion 43a is molded to a predetermined size, forming a flat portion 43c at the top of the dam material 43, making it possible to stabilize the overall height of the light-emitting device 4.

Similar to the sealing material 50, the sealing material 53 is injected (filled) inside the dam material 43 arranged on the circuit board 15, i.e., the area surrounded by the dam material 43, and hardened into a roughly disk shape, integrally covering and protecting (sealing) the multiple LED elements 30. The upper surface of the sealing material 53 is located at the same height as the flat portion 43c of the first portion 43a of the dam material 43. That is, at least a portion of the first portion 43a of the dam material 43 is in contact with the sealing material 53, and the dam material 43 contains the above-mentioned pigment on the surface in contact with the sealing material 53. The sealing material 53 is formed of the same material as the sealing material 50.

Figures 9(a) to 9(e) are schematic diagrams illustrating a method for manufacturing the light-emitting device 4. The method for manufacturing the light-emitting device 4 will be described below with reference to Figure 9.

The manufacturing procedure shown in Figures 9(a) and 9(b) is the same as that shown in Figures 3(a) and 3(b). After the LED elements 30 are mounted on the upper surface of the mounting substrate 10, uncured second portion resin 43' is filled from a specified supply nozzle so as to draw a circle around the multiple LED elements 30 and cover the first electrode 20 and the second electrode 22. Figure 9(c) is an image of a cross section when uncured second portion resin 43' is formed on the first electrode 20 and the second electrode 22.

Next, the first portion 43a, which is formed in an annular, L-shape, is placed on top of the uncured second portion resin 43', with the flat portion 43c facing upward (the opposite side of the mounting substrate 10) and along the second portion resin 43'. Next, the tip of the base portion 43d is inserted from the top of the uncured second portion resin 43'. After that, the second portion resin 43' is heated, and the portions inside and outside the first portion 43a are formed as the second portion 43b. Figure 9(d) is an image of a cross section when the second portion 43b is formed with the first portion 43a in between.

Next, uncured sealing resin is filled from a specified supply nozzle into the inside of the dam material 43 up to the height of the flat portion 43c of the first portion 43a and heated to form the sealing material 53, completing the light emitting device 4. Figure 9(e) is an image of a cross section of the sealing material 53 when it is formed.

Fifth Embodiment
FIG. 10A is a plan view of a light emitting device 5 according to the fifth embodiment as viewed from above, and FIG. 10B is a cross-sectional view taken along the line AA' in FIG. 10A.

The light emitting device 5 has, as its main components, a mounting substrate 10, a circuit board 15, a plurality of LED elements 30, a dam material 44, and a sealing material 54. The configurations of the mounting substrate 10, the circuit board 15, and the plurality of LED elements 30 are similar to those of the mounting substrate 10, the circuit board 15, and the plurality of LED elements 30 of the light emitting device 1. Note that in FIG. 10(a), the elements located within the opening 16 of the circuit board 15 and the elements located below the dam material 44 are omitted from the illustration in order to make the illustration easier to understand.

The dam material 44 is an example of a holding material, and includes a first portion 44a and a second portion 44b. The first portion 44a is an annular frame that is arranged around the LED element 30 on the mounting board 10, similar to the dam material 40, and absorbs light. The first portion 44a is formed to have an L-shaped cross section, has a flat portion 44c at the top, and further has a base portion 44d that is arranged on the circuit board 15 and extends to the outer end of the flat portion 44d. The second portion 44b is arranged inside the first portion 44a, and has a reflective surface whose height from the mounting board 10 gradually decreases from the outside where the first portion 44a is arranged to the inside where the LED element 30 is mounted. The flat portion 44c formed on the upper portion of the first portion 44a is located at a position higher than the top of the second portion 44b.

The first portion 44a contains a molding resin and a specified pigment. This pigment is the same as the pigment contained in the dam material 40. The first portion 44a may be formed of a metal material having the same color as the pigment, or a metal material that has been surface-treated with the pigment. On the other hand, the second portion 44b does not contain this pigment, and is made of a reflective white resin that contains a silicone resin and a reflective material such as titanium oxide (or silica).

The second portion 44b reflects the blue light emitted laterally from each LED element 30 and the light emitted laterally from each LED element 30 and wavelength-converted by the phosphor contained in the sealing material 54 upward from the light-emitting device 5. On the other hand, the above-mentioned pigment is dispersed throughout the first portion 44a. The first portion 44a reflects the blue light emitted laterally from each LED element 30 upward from the light-emitting device 5, while absorbing the light emitted laterally from each LED element 30 and wavelength-converted by the phosphor contained in the sealing material 54. In the light-emitting device 5, the light emitted from the LED element 30 and the phosphor is reflected upward by the second portion 44b, so that the emission efficiency is higher than that of the light-emitting device 1. On the other hand, in the light-emitting device 5, the light wavelength-converted by the phosphor is absorbed by the first portion 44a, so that the occurrence of a yellow ring is suppressed and the color of the light emitted from the light-emitting device 5 can be kept uniform.

In addition, in the light emitting device 5, the first portion 44a molded to a predetermined size forms a flat portion 44c on the top of the dam material 44, making it possible to stabilize the overall height of the light emitting device 5. Furthermore, in the light emitting device 5, the first portion 44a molded to a predetermined shape is provided, making it possible to form the second portion 44b along the first portion 44a, and making it easy to form the second portion 44b into a concave shape.

Similar to the sealing material 50, the sealing material 54 is injected (filled) inside the dam material 44 arranged on the circuit board 15, i.e., the area surrounded by the dam material 44, and hardened into a roughly disk shape, integrally covering and protecting (sealing) the multiple LED elements 30. The upper surface of the sealing material 54 is located at the same height as the flat portion 44c of the first portion 44a of the dam material 44. That is, at least a portion of the first portion 44a of the dam material 44 is in contact with the sealing material 54, and the dam material 44 contains the above-mentioned pigment on the surface in contact with the sealing material 54. The sealing material 54 is formed of the same material as the sealing material 50.

Figures 11(a) to 11(e) are schematic diagrams illustrating a method for manufacturing the light-emitting device 5. The method for manufacturing the light-emitting device 5 will be described below with reference to Figure 11.

The manufacturing procedure shown in Figures 11(a) to 11(b) is the same as that shown in Figures 3(a) to 3(b). After the LED elements 30 are mounted on the upper surface of the mounting substrate 10, the first portion 44a, which is formed in an annular, L-shape, is arranged around the LED elements 30, particularly on the outside of the first electrode 20 and the second electrode 22, with the flat portion 44c facing upward (the opposite side of the mounting substrate 10). Next, the tip of the base portion 44d is adhered to the circuit substrate 15 with an adhesive. Figure 11(c) is an image of a cross section of the first portion 44a when it is arranged on the circuit substrate 15.

Next, uncured resin for the second portion is filled from a specified supply nozzle onto the inside of the first portion 44a so as to cover the first electrode 20 and the second electrode 22. This forms the second portion 44b so that its height gradually decreases from the outside to the inside. Figure 11(d) is an image of the cross section of the second portion 44b when it is formed on the first electrode 20 and the second electrode 22.

Next, uncured sealing resin is filled from a specified supply nozzle into the inside of the dam material 44 up to the height of the flat portion 44c of the first portion 44a and heated to form the sealing material 54, completing the light-emitting device 5. Figure 11(e) is an image of a cross section of the sealing material 54 when it is formed.

In the light emitting devices 1 to 5 described above, as shown in Figures 1, 4, 6, 8, and 10, a substrate is used in which a circuit board 15 with a wiring pattern is attached to an aluminum mounting substrate 10 (COB). However, in the light emitting devices 1 to 5, a substrate in which a wiring pattern is directly arranged on a ceramic mounting substrate 10 without providing a circuit board 15 may also be used (SMD).

REFERENCE SIGNS LIST 1, 2, 3, 4, 5 Light emitting device 10 Mounting board 15 Circuit board 30 LED element 40, 41, 43, 44 Dam material 41a, 43a, 44a First portion 41b, 43b, 44b Second portion 50, 51, 52, 53, 54 Sealing material

Claims (4)

A substrate;
A light emitting element mounted on the substrate;
a support material disposed around the light emitting element on the substrate;
a sealant filled inside the holding material to seal the light emitting element;
the sealing material includes a fluorescent material that converts the wavelength of light emitted from the light-emitting element and emits the converted light,
the retention material includes a pigment having an absorption band of an absorption spectrum that includes a peak wavelength of light emitted by the fluorescent material and that does not include a peak wavelength of light emitted by the light-emitting element,
The retention material includes a first portion including a resin and the pigment, and a second portion including a resin and a reflective material without including the pigment, the second portion being disposed inside and outside the first portion.
A light emitting device characterized by: The light emitting device according to claim 1, wherein the first portion has a flat portion at the top. The light emitting device according to claim 2 , wherein an upper surface of the sealing material is positioned at the same height as the flat portion. The light emitting device according to any one of claims 1 to 3, wherein the light emitted from the fluorescent material has a yellow color, and the pigment has a blue color.

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