JP2013149690A - Light-emitting device and illuminating device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a light-emitting device having high light extraction efficiency without increasing a thickness of the light-emitting device.SOLUTION: A light-emitting device 10 comprises an encapsulation body 4 composed of a first resin body 41 which encapsulates a light-emitting device 3 and a second resin body 42 which coats the first resin body 41. Bottom surface parts of the first resin body 41 and the second resin body 42 contact with a light-emitting device mounting surface 1a of a substrate 1, and a side surface part 42a of the second resin body 42 is exposed.

Description

  The present invention relates to a light emitting device and a lighting device including the light emitting device, and more particularly to a light emitting device such as a light emitting diode in which a light emitting element is sealed with a resin body, and the lighting device.

  In recent years, light emitting diodes (LEDs) have been widely used as backlights for small mobile terminal lighting, indoor / outdoor general lighting, automobile lighting, and large liquid crystal displays (LCDs). It is expanding gradually.

  The LED is provided in the form of a package depending on the purpose of use and the required form. For example, FIG. 8 is a cross-sectional view schematically showing a general light emitting device (LED) 100. As shown in FIG. 8, the light emitting device 100 includes a substrate 101 on which a pair of electrodes 102 are formed, a light emitting element 103 provided on the substrate 101, and a translucent resin body 104 that seals the light emitting element 103. It is composed of The light emitting element 103 is connected to the electrode 102 through a bonding wire 107. The translucent resin body 104 seals the upper side (outgoing direction) of the light emitting element 103. The translucent resin body 104 is made of, for example, an epoxy resin, a silicone resin, or a combination thereof. In particular, when the light-emitting device 100 is a white diode, the blue light-emitting element 103 is sealed with a translucent resin body 104 to which a yellow phosphor or a red phosphor and a green phosphor are added. Then, white light is obtained by mixing the blue light emitted from the blue light emitting element 103 and the light wavelength-converted by the phosphor. A method for obtaining white light in this way is common. In recent years, LED chips with small external dimensions have been manufactured, and LED packages having a plurality of LED chips mounted on one package have also been manufactured.

  For example, FIG. 10 is a cross-sectional view of the LED package 200 described in Patent Document 1. As shown in FIG. 10, in the LED package 200, a reflector body 208 made of white ceramics and surrounding the light emitting element 203 on a substrate 201 on which a plurality of light emitting elements 203 are mounted, and an outer surface of the reflector body 208 are integrally formed. The provided frame body 209 is mounted. A plurality of through holes are formed in the reflector body 208, and one or a plurality of light emitting elements 203 are accommodated in the respective through holes. Further, each through hole is filled with a sealing resin body 204 in which a phosphor 210 that is a wavelength conversion material is dispersed and mixed. In this LED package 200, the light emitted from the light emitting element 203 is reflected by the surface of the reflector body 208 made of white ceramics, and the light is extracted in front of the LED package 200.

  On the other hand, FIG. 11 is a cross-sectional view of the light emitting device 300 described in Patent Document 2. As shown in FIG. 11, in the light emitting device 300, the light emitting element 303 is sealed with a dome-shaped wavelength conversion member 342 and a transparent member 341 in order to increase the light extraction efficiency of the light emitting device 300. Specifically, the dome-shaped radii of the wavelength conversion member 342 and the transparent member 341 are set to be less than the total reflection angle caused by the difference in refractive index between the wavelength conversion member 342 or the transparent member 341 and air. For example, in FIG. 11, the cross-sectional shape R of the outer surface of the transparent member 341 that is a light emission surface to air is a semicircle from the semi-ellipse R1 that is less than the total reflection angle of the transparent member 341 that forms the light emission surface. A range up to R2 is set. Thereby, the light emitted from the light emitting element 303 is efficiently taken out into the air.

JP 2010-118560 A (released May 27, 2010) JP 2007-317952 A (published on December 6, 2007)

  However, the technique described in Patent Document 1 has a problem that the light extraction efficiency of the light emitting device (package) as a whole is low. Further, the technique described in Patent Document 2 has a problem that the thickness of the light emitting device increases.

  Specifically, in the technique described in Patent Document 1, a part of the light emitted from the light emitting element 203 (LED chip) is reflected on the surface of the reflector body 208 made of white ceramics. A part of the light whose wavelength is converted by the phosphor 210 is also reflected by the surface of the reflector body 208. Since the reflectance of light in the visible light region (light in the wavelength region of 380 nm to 780 nm) on the white ceramic surface is about 80 to 90%, reflection loss due to the surface of the reflector body 208 occurs. As a result, there is a problem that the light extraction efficiency of the entire LED package 200 is lowered.

  Further, in the LED package 200 of FIG. 10, there is a case where the reflector body 208 made of white ceramics does not exist in the vicinity of the light emitting element 203 and only the frame body 209 exists. However, in this case, the frame body 209 for forming the sealing resin portion is provided at the installation portion of the reflector main body 208. However, the frame body 209 is generally formed of a white resin. For this reason, even when the reflector main body 208 is not present, there is a problem that reflection loss due to the frame body 209 occurs, and the light extraction efficiency of the entire LED package package decreases.

  In the technique described in Patent Document 2, the cross-sectional shapes of the outer surfaces of the wavelength conversion member 342 and the transparent member 341 are set so as to prevent total reflection occurring at the interface between the wavelength conversion member 342 or the transparent member 341 and air. doing. For this reason, compared with the size of the light emitting element 303, the radius of the cross-sectional shape (dome shape) of the wavelength conversion member 342 or the transparent member 341 becomes larger than necessary. When a plurality of light emitting elements 303 are mounted on the substrate 301, the radius of the cross-sectional shape (dome shape) of the wavelength conversion member 342 or the transparent member 341 is further increased. As a result, there is a problem that the thickness of the light emitting device 300 increases. Furthermore, when the radius of the cross-sectional shape (dome shape) of the wavelength conversion member 342 or the transparent member 341 is increased, the amount of use of the wavelength conversion member 342 or the transparent member 341 inevitably increases. As a result, there is a problem that the cost of the light emitting device 300 is increased.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a light-emitting device and a lighting device with high light extraction efficiency without increasing the thickness of the light-emitting device.

  In order to solve the above-described problems, a light-emitting device according to the present invention includes a substrate, a light-emitting element mounted on the substrate, and a sealing resin that seals the light-emitting element. The bottom surface portion of the resin is in contact with the light emitting element mounting surface of the substrate, and the side surface portion of the sealing resin is exposed.

  According to said structure, while the bottom face part of sealing resin is in contact with the board | substrate, the side part of sealing resin is exposed. That is, neither the reflector body 208 nor the frame body 209 as described in Patent Document 1 (FIG. 10) is present in the vicinity of the light emitting element. For this reason, there is no loss of light emitted from the light emitting elements by the reflector main body 208 and the frame body 209. That is, the loss of light emitted from the light emitting element is reduced only to the loss due to Fresnel reflection at the interface between the sealing resin surface (light emitting surface) and the outside (for example, air). Therefore, the light extraction efficiency can be increased. For this reason, it is not necessary to increase the thickness of the sealing resin more than necessary as in Patent Document 2 in order to increase the light extraction efficiency.

  Thus, according to the above configuration, it is possible to provide a light emitting device with high light extraction efficiency without increasing the thickness of the sealing resin, and hence the thickness of the light emitting device.

  In the light emitting device according to the present invention, in the sealing resin, it is preferable that a light emitting surface for emitting the emitted light of the light emitting element is a scattering surface for scattering the emitted light of the light emitting element.

  According to said structure, the light-projection surface of sealing resin is a scattering surface. As a result, the total reflection condition is broken at the light exit surface of the sealing resin. For this reason, it becomes possible to take out the light which was not taken out by the total reflection in the interface of the sealing resin surface (light emission surface) and the exterior (for example, air) among the emitted light from a light emitting element. Therefore, the light extraction efficiency can be further increased.

  In the light emitting device according to the present invention, the scattering surface may be an uneven surface on which a single or a plurality of cones or pyramids are formed.

  According to said structure, the light-projection surface of sealing resin is an uneven surface. As a result, the total reflection condition is broken by the cone or pyramid formed on the light exit surface of the sealing resin. For this reason, it becomes possible to take out the light which was not taken out by the total reflection in the interface of the sealing resin surface (light emission surface) and the exterior (for example, air) among the emitted light from a light emitting element. Therefore, the light extraction efficiency can be further increased.

  Further, according to the above configuration, since the light emission surface of the sealing resin is an uneven surface, the amount of the sealing resin can be reduced as compared with the case where no cone or pyramid is formed on the light emission surface. Can do. That is, it is possible to reduce the thickness of the sealing resin and thus the light emitting device, and to reduce the manufacturing cost of the light emitting device.

  In the light emitting device according to the present invention, the sealing resin includes a first resin that seals the light emitting element and a second resin that covers the first resin, and at least one of the first resin and the second resin. However, it is preferable to include a phosphor that converts the wavelength of the emitted light of the light emitting element.

  According to said structure, the fluorescent substance which converts the wavelength of the emitted light of a light emitting element is added to at least one of 1st resin and 2nd resin. For this reason, a part of the emitted light from the light emitting element is wavelength-converted by the phosphor. Therefore, it is possible to take out light that is a mixture of light emitted from the light emitting element (light that has not been wavelength-converted) and light that has been wavelength-converted by the phosphor.

  In the light emitting device according to the present invention, it is preferable that the first resin and the second resin each include a resin of the same material.

  According to said structure, 1st resin and 2nd resin are comprised including the same resin, respectively. For this reason, the loss by Fresnel reflection in the interface of 1st resin and 2nd resin can be reduced. In particular, when the first resin and the second resin are made of the same resin, this loss can be eliminated. Therefore, the light extraction efficiency between the light emitted from the light emitting element and the light whose wavelength has been converted by the phosphor can be increased. Therefore, a light emitting device with higher light extraction efficiency can be provided.

  In order to solve the above-described problem, an illumination device according to the present invention includes any one of the light-emitting devices. Therefore, it is possible to provide an illumination device including a light emitting device with high light extraction efficiency without increasing the thickness of the light emitting device.

  In the light emitting device and the lighting device of the present invention, as described above, the bottom surface portion of the sealing resin is in contact with the light emitting element mounting surface of the substrate, and the side surface portion of the sealing resin is exposed. It is. Therefore, there is an effect that it is possible to provide a light emitting device and a lighting device with high light extraction efficiency without increasing the thickness of the light emitting device.

It is sectional drawing which shows the structure of the light-emitting device which concerns on one Embodiment of this invention. It is sectional drawing which shows the locus | trajectory of the light radiate | emitted from the light emitting element in the light-emitting device of FIG. It is the graph which compared the light extraction efficiency of the light-emitting device which concerns on one Embodiment of this invention, and the conventional light-emitting device. It is sectional drawing which shows the structure of the light-emitting device which concerns on one Embodiment of this invention. It is sectional drawing which shows the structure of the light-emitting device which concerns on one Embodiment of this invention. It is the graph which compared the light extraction efficiency of the light-emitting device which concerns on one Embodiment of this invention, and the conventional light-emitting device. It is the schematic which shows the structure of the illuminating device provided with the light-emitting device of FIG. It is sectional drawing which shows the structure of the conventional common light-emitting device. It is sectional drawing which shows the locus | trajectory of the light radiate | emitted from the light emitting element in the light-emitting device of FIG. It is sectional drawing of the LED package described in patent document 1. FIG. It is sectional drawing of the light-emitting device 300 described in patent document 2. FIG.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. For comparison with the embodiment of the present invention, FIG. 8 and FIG. 9 are also referred to as appropriate. In each drawing used in the following description, the scale is appropriately changed to make each member a recognizable size. Further, the present invention is not limited to the configurations of the following embodiments and drawings. Furthermore, for convenience of explanation, members having the same function in each embodiment are denoted by the same reference numerals, and description thereof is omitted.

[Embodiment 1]
(Configuration of Light Emitting Device 10)
A basic configuration of the light-emitting device according to Embodiment 1 of the present invention will be described with reference to FIG. FIG. 1 is a cross-sectional view illustrating a configuration of a light emitting device 10 according to the first embodiment. As shown in FIG. 1, a light emitting device 10 includes a substrate 1, a pair of electrodes 2 formed on the substrate 1, a light emitting element 3 mounted on the substrate 1, and a sealing body for sealing the light emitting element 3 ( It is mainly composed of (sealing resin) 4.

  A wiring 11 is formed on the substrate 1, and the electrode 2 and the light emitting element 3 are electrically connected via the wiring 11. The electrode 2 is formed on the light emitting element mounting surface 1 a on the substrate 1. The light emitting element 3 is a light source in the light emitting device 10. The light emitting element 3 may be an LED, a phosphor, an electroluminescence element, a semiconductor light source, or the like. The sealing body 4 includes a first resin body 41 (first resin) that seals the light emitting element 3 and a second resin body 42 (second resin) that covers the first resin body 41. The first resin body 41 is made of a translucent resin including a phosphor 43 that converts the wavelength of the light emitted from the light emitting element 3. The second resin body 42 is made of a translucent resin that does not include the phosphor 43. The side surface portion 42a of the second resin body 42 is exposed. The bottom surface portion 42 b of the second resin body 42 is in contact with the light emitting element mounting surface 1 a of the substrate 1.

(Characteristic configuration of light-emitting device 10: comparison with conventional configuration)
FIG. 2 is a cross-sectional view showing a locus of light emitted from the light emitting element 3 in the light emitting device 10 of FIG. FIG. 8 is a cross-sectional view showing a configuration of a conventional general light emitting device 100. FIG. 9 is a cross-sectional view showing a locus of light emitted from the light emitting element in the light emitting device of FIG.

  The biggest difference between the light emitting device 10 of FIG. 1 and the light emitting device 100 of FIG. 8 is that the light emitting device 10 of this embodiment does not include the reflector main body 208 or the frame 209 mounted on the light emitting device 100 of FIG. Is a point. That is, the greatest feature of the light emitting device 10 is that the side surface portion of the sealing body 4 (specifically, the side surface portion 42a of the second resin body 42) is exposed.

(1) Conventional Light-Emitting Device Specifically, the light-emitting device 100 of FIG. 8 mainly includes a substrate 101, an electrode 102, a light-emitting element 103, a translucent resin body 104 containing a phosphor, and a reflector (frame body) 106. It is configured. In the light emitting device 100, when the light emitting element 103 is a white diode, blue light having a wavelength of about 450 nm is emitted from the light emitting element 3, and part of the blue light is emitted to the outside of the translucent resin body 104. Excites the phosphor inside the translucent resin body 104 to convert the wavelength. The blue light and the wavelength-converted light are mixed to obtain white light.

  On the other hand, the arrows in FIG. 9 indicate the locus of light emitted from the light emitting element 103. In the light emitting device 100, the light emitting element 103 is surrounded by a reflector 106, and a translucent resin body 104 is enclosed therein. The reflector 106 generally used is made of a material such as white ceramics or a white resist, and has a reflectance of about 80 to 90% for visible light. Further, the surface of the translucent resin body 104 is generally a flat surface. In particular, in a high-intensity package for illumination, a plurality of light-emitting elements 103 are planarly mounted on a substrate 101, and the plurality of light-emitting elements 103 include a light-transmitting resin body 104 containing a phosphor in a large area at a time. It is sealed. For this reason, the surface (light emitting surface, sealing interface) 104a of the translucent resin body 104 is a flat surface that is substantially parallel to the light emitting element mounting surface of the substrate 101. In the light emitting device 100, sealing with a small amount of phosphor resin is performed in consideration of reduction in the number of sealing resins and phosphors included in the translucent resin body 104. For this reason, the distance between the light emitting element 103 and the surface 104a of the translucent resin body 104 is very close to several hundred μm. As shown by the arrows in FIG. 9, the locus of the light emitted from the light emitting element 103 and the light whose wavelength has been converted by the phosphor has the following three patterns (a) to (c).

  (A) Due to the difference in refractive index between the translucent resin body 104 and air, light incident on the interface between the translucent resin body 104 and air at an angle less than the critical angle is transmitted to the outside of the translucent resin body 104. Refraction is emitted.

  (B) Light incident on the interface between the translucent resin body 104 and air at an angle greater than the critical angle is totally reflected toward the inside of the translucent resin body 104. As a result, the totally reflected light is lost inside the translucent resin body 104 or the wavelength is converted by exciting the phosphor inside the translucent resin body 104. For example, when the translucent resin body 104 is a commonly used silicone resin, its refractive index is about 1.4, so the critical angle is about 45 degrees according to Snell's law. For this reason, blue light (emitted light from the light emitting element 103) having an angle of 45 degrees or more is reflected into the translucent resin body 104.

  (C) Finally, the light is reflected by the reflector 106 provided around the light emitting element 103, refracted at the interface between the translucent resin body 104 and air, and emitted to the outside. At this time, since the reflectance of the general reflector 106 is about 80 to 90%, a reflection loss occurs, and the intensity of light emitted to the outside (light extraction efficiency) decreases.

(2) Light emitting device 10 of this embodiment
On the other hand, as shown in FIG. 1, the light emitting device 10 according to the present embodiment is mainly composed of a substrate 1, an electrode 2, a light emitting element 3, and a sealing body 4 (first resin body 41, second resin body 42). . In the light emitting device 10, as an example, the angle θ formed by the side surface portion 42 a of the second resin body 42 and the light emitting element mounting surface 1 a of the substrate 1 is 30 °.

  On the other hand, arrows in FIG. 2 indicate the locus of light emitted from the light emitting element 3. The same path as that of the general light emitting device 100 is followed.

  (A) Due to the difference in refractive index between the second resin body 42 and air, the light incident on the interface between the second resin body 42 and air at an angle less than the critical angle is refracted outside the second resin body 42. Are emitted. That is, a part of the light emitted from the light emitting element 3 and the light converted in wavelength by the phosphor 43 is an angle equal to or less than the critical angle at the interface between the second resin body 42 facing the light emitting element 3 and the air. The light incident on is refracted into the air and emitted.

  (B) Light incident on the interface between the second resin body 42 and air at an angle greater than the critical angle is totally reflected toward the inside of the second resin body 42.

  (C) The light incident on the side surface portion 42a of the second resin body 42 is refracted and emitted into the air in accordance with Snell's law at the interface between the side surface portion 42a of the second resin body 42 and the air. Here, by adjusting the angle θ formed between the side surface portion 42a of the second resin body 42 and the substrate 1, the ratio of light incident on the interface between the side surface portion 42a and air at an angle greater than the critical angle is increased. Is possible. As a result, light can be emitted from the second resin body 42 to the outside without causing loss due to Fresnel reflection at the interface between the side surface portion 42a and air.

(3) Comparison of Light Extraction Efficiency FIG. 3 is a graph comparing the light extraction efficiency between the light emitting device 10 according to the present embodiment and the conventional light emitting device 100. 3 analyzes the relationship between the light extraction efficiency obtained from the light emitting device 100 when the angle (θ ′) between the reflector 106 and the substrate 101 is changed in the light emitting device 100 of FIG. It is the result. The reflectance of the reflector 106 was analyzed as 90%.

  On the other hand, the square plot (θ ≦ 90) in FIG. 3 is the result of analyzing the relationship between the angle (θ) formed by the second resin body 42 and the substrate 1 and the light extraction efficiency obtained from the light emitting device 10. . The second resin body 42 is a commonly used silicone resin and has a refractive index of 1.4. Further, the substrate 1 was made of a white ceramic material, and the reflectance was 90% on the light emitting element mounting surface 1a.

  From the graph of FIG. 3, it can be seen that the light emitting device 10 in which the side surface portion 42 a of the second resin body 42 is exposed has higher light extraction efficiency than the conventional light emitting device 100. Furthermore, it can be seen that the light extraction efficiency increases as the angle θ becomes smaller than 90 ° (the sharper the angle becomes). This is because the smaller the angle θ formed between the side surface portion 42a of the second resin body 42 and the substrate 1, the greater the proportion of light incident on the interface between the side surface portion 42a and air at an angle greater than the critical angle. . Further, when the angle θ is an acute angle, the size of the substrate 1 (the area of the light emitting element mounting surface 1a) can be made smaller than when the angle θ is an obtuse angle.

  As described above, the light emitting device 10 of the present embodiment in which neither the reflector 106 nor the frame is present has significantly higher light extraction efficiency from the light emitting device 10 than the light emitting device 100 in which the reflector 106 is present.

(Production example of light-emitting device 10)
The light emitting device 10 of the present embodiment can be manufactured as follows, for example.

  First, the light emitting element 3 is placed on the substrate 1, and the electrode 2 and the light emitting element 3 provided on the same surface on the substrate 1 are wire-bonded and electrically connected to each other through the wiring 11. Next, the first resin body 41 containing the phosphor 43 is quantitatively applied onto the light emitting element 3 using a dispenser or the like. Thereafter, the first resin body 41 containing the phosphor 43 is cured by a method such as heating, and the light emitting element 3 is sealed with the first resin body 41.

  Next, a liquid second resin body 42 having translucency is quantitatively applied to the surface of the first resin body 41, and the first resin body 41 is covered with the second resin body 42. As described above, the shape (angle θ) of the side surface portion 42 a of the second resin body 42 affects the light extraction efficiency of the light emitting device 10. For this reason, it is preferable that the second resin body 42 be precisely manufactured by mold molding or the like. Finally, the liquid second resin body 42 is cured by means such as heating to join the first resin body 41 containing the phosphor 43 and the second resin body 42 not containing the phosphor 43. . In this way, the light emitting device 10 can be manufactured.

  The step of joining the first resin body 41 and the second resin body 42 is performed in a vacuum state in order to prevent air from entering the interface between the first resin body 41 and the second resin body 42. It is preferable.

  As described above, according to the light emitting device 10, the bottom surface portion 42b of the second resin body 42 is in contact with the substrate 1, while the side surface portion 42a of the second resin body 42 is exposed. That is, in the vicinity of the light emitting element 3, there is neither a reflector main body nor a frame mounted on a general light emitting device (see FIGS. 8 to 11). For this reason, there is no loss of light emitted from the light emitting element by the reflector body and the frame. That is, the loss of light emitted from the light emitting element 3 is reduced only to the loss due to Fresnel reflection at the interface between the sealing body surface (the light emitting surface 42c of the second sealing body 42) and the outside (for example, air). The Therefore, the light extraction efficiency of the light emitting device 10 can be increased. For this reason, it is not necessary to increase the thickness of the sealing body 4 more than necessary as in Patent Document 2 in order to increase the light extraction efficiency.

  As described above, according to the light emitting device 10, it is possible to provide the light emitting device 10 having high light extraction efficiency without increasing the thickness of the sealing body 4, and hence the thickness of the light emitting device 10.

  In the light emitting device 10, the sealing body 4 includes a first resin body 41 that seals the light emitting element 3 and a second resin body 42 that covers the first resin body 41, and the first resin body. 41 is added with a phosphor 43 that converts the wavelength of emitted light from the light emitting element 3. For this reason, a part of the emitted light from the light emitting element 3 is wavelength-converted by the phosphor 43. Accordingly, it is possible to take out light that is a mixture of light emitted from the light emitting element 3 (light that has not been wavelength-converted) and light that has been wavelength-converted by the phosphor 43.

  In addition, when mixing light in this way, the fluorescent substance 43 should just be added to at least one of the 1st resin body 41 and the 2nd resin body 42. FIG. Further, when light is not mixed (when wavelength conversion is not necessary), it is not necessary to add the phosphor 43 to either the first resin body 41 or the second resin body 42. In this case, the sealing body 4 may be configured from one of the first resin body 41 or the second resin body 42.

  The resin material which comprises the 1st resin body 41 and the 2nd resin body 42 is not specifically limited. However, it is preferable that the first resin body 41 and the second resin body 42 each include a resin of the same material, and more preferably configured from a resin of the same material. When the first resin body 41 and the second resin body 42 are configured to include the same resin, the loss due to Fresnel reflection at the interface between the first resin body 41 and the second resin body 42 is reduced. Can do. In particular, when the first resin body 41 and the second resin body 42 are made of the same resin, this loss can be eliminated. Therefore, the light extraction efficiency between the light emitted from the light emitting element 3 and the light converted in wavelength by the phosphor 43 can be increased. Therefore, it is possible to provide the light emitting device 10 with higher light extraction efficiency.

  The material of the 1st resin body 41 and the 2nd resin body 42 can be comprised from the resin etc. which combined the epoxy resin, the silicone resin, or them, for example.

  Thus, in the light-emitting device 10 of this embodiment, neither a reflector nor a frame provided in a general light-emitting device exists. Further, an angle θ formed by the side surface portion 42a of the second resin body 42 and the light emitting element mounting surface 1a of the substrate 1 is an acute angle. Thereby, reflection loss is reduced and high light extraction efficiency can be obtained. By mounting such a light emitting device 10 on various lighting devices, it is possible to realize a lighting device with high light extraction efficiency.

[Embodiment 2]
Next, based on FIG. 4, the light-emitting device 10a in another embodiment of this invention is demonstrated. FIG. 4 is a cross-sectional view showing the configuration of the light emitting device 10a according to the second embodiment. Below, it demonstrates centering on difference with the light-emitting device 10 of Embodiment 1. FIG.

  As shown in FIG. 1, in the light emitting device 10, the angle θ formed by the side surface portion 42 a of the second resin body 42 and the light emitting element mounting surface 1 a of the substrate 1 is an acute angle. On the other hand, as shown in FIG. 4, an angle θ formed by the side surface portion 42 a of the second resin body 42 and the light emitting element mounting surface 1 a of the substrate 1 is an obtuse angle. For example, in FIG. 4, this angle θ is 150 °. Otherwise, the light emitting device 10 and the light emitting device 10a are substantially the same.

  An arrow in FIG. 4 indicates a locus of light emitted from the light emitting element 3. The locus of the light emitted from the light emitting element 3 in the light emitting device 10a follows the same locus as in the above (A) to (C) in the light emitting device 10.

  In FIG. 3, the light extraction efficiency of the light emitting device 10a according to the present embodiment and the conventional light emitting device 100 are also compared. That is, the square plot (θ> 90) in FIG. 3 is a result of analyzing the relationship between the angle (θ) formed by the second resin body 42 and the substrate 1 and the light extraction efficiency obtained from the light emitting device 10a. . The second resin body 42 is a commonly used silicone resin and has a refractive index of 1.4. Further, the substrate 1 was made of a white ceramic material, and the reflectance was 90% on the light emitting element mounting surface 1a.

  From the graph of FIG. 3, it can be seen that the light emitting device 10 a in which the side surface portion 42 a of the second resin body 42 is exposed has higher light extraction efficiency than the conventional light emitting device 100. Further, it can be seen that the light extraction efficiency increases as the angle θ is larger than 90 ° (closer to 180 °).

  In addition, when the 2nd resin body 42 containing the fluorescent substance 43 is apply | coated and hardened on the light emitting element 3, without providing a reflector like the light-emitting device 10a, the shape of the side part 42a of the 2nd resin body 42 is shown. Is determined by the wettability between the second resin body 42 containing the phosphor 43 and the substrate 1. For this reason, in the light emitting device 10a, it becomes difficult to control the angle θ between the side surface portion 42a of the second resin body 42 and the substrate 1. In addition, since the application amount of the first resin body 41 containing the phosphor 43 also varies, it is difficult to control the angle θ. Therefore, in this embodiment, the light emitting element 3 is sealed with the first resin body 41 containing the phosphor 43, and the first resin body 41 is sealed (covered) with the second resin body 42 made of a translucent resin. ) Further, it is desirable that the second resin body 42 is produced by mold molding or the like.

  As described above, in the light emitting device 10a of the present embodiment, neither a reflector nor a frame provided in a general light emitting device exists. Further, the angle θ formed by the side surface portion 42a of the second resin body 42 and the light emitting element mounting surface 1a of the substrate 1 is an obtuse angle. Thereby, reflection loss is reduced and high light extraction efficiency can be obtained. By mounting such a light emitting device 10a on various lighting devices, it is possible to realize a lighting device with high light extraction efficiency.

[Embodiment 3]
(Configuration of Light Emitting Device 10b)
Next, based on FIG. 5, the light-emitting device 10b in another embodiment of this invention is demonstrated. FIG. 5 is a cross-sectional view illustrating a configuration of a light emitting device 10b according to Embodiment 3. Below, it demonstrates centering on difference with the light-emitting device 10 of Embodiment 1. FIG.

  As shown in FIG. 1, in the light-emitting device 10, the surface (light emission surface 42c) of the 2nd resin body 42 is a flat surface. On the other hand, as shown in FIG. 5, in the light emitting device 10 b, the surface (light emission surface 42 c) of the second resin body 42 is a scattering surface that scatters the emitted light of the light emitting element 3. Specifically, in the light emitting device 10b, the light emitting surface 42c is an uneven surface. Otherwise, the light emitting device 10 and the light emitting device 10b are substantially the same.

  Specifically, in the light emitting device 10b, one or a plurality of cones or pyramids are formed on the surface (light emitting surface 42c) of the second resin body 42, and the light emitting surface 42c is an uneven surface. The arrows in FIG. 5 indicate the locus of light emitted from the light emitting element 3 when the light emitting surface 42c is an uneven surface. In this case, since the probability of light incident at an angle less than the critical angle from the uneven surface of the light exit surface 42c to the air layer is higher, the light exit surface 42c is lighter than when the light exit surface 42c is substantially parallel to the substrate 1. The take-out efficiency increases.

  FIG. 5 shows an example of the configuration. By changing the width of each unevenness, the distance between the individual unevennesses, the angle of the unevenness tip, etc., the light extraction efficiency can be increased and the light distribution characteristics can be controlled. It becomes possible. In order to increase the light extraction efficiency, it is preferable that the angle of the tip of the unevenness is as small as possible. In other words, the aspect ratio of the unevenness is preferably as large as possible.

  Further, the light exit surface 42c (uneven surface) of the light emitting device 10b and the uneven structure described in Patent Document 2 are functionally and structurally different. Specifically, the unevenness in the light emitting device 10 b has a function of scattering the emitted light from the light emitting element 3. For this reason, irregularities of the order of mm (millimeter) are formed. On the other hand, the concavo-convex structure of Patent Document 2 is intended to eliminate reflection loss. For this reason, a concavo-convex structure of a wavelength order is formed.

  The uneven surface can be formed on the order of several mm if it is formed by molding or the like. For this reason, as in Patent Document 2 (FIG. 11), the thickness (first) of the sealing body 4 is greater than that of the light emitting device 300 in which the wavelength conversion member 342 or the transparent member 341 has a dome-shaped cross section to increase the light extraction efficiency. 1 resin body 41 thickness + second resin body 42 thickness) can be reduced. Thereby, it becomes possible to reduce the amount of resin used for the sealing body 4 as compared with the prior art, leading to cost reduction of the sealing body 4 and consequently cost reduction of the light emitting device 10b.

  In the light emitting device 10b, the angle formed between the side surface portion 42a of the second resin body 42 and the substrate 1 is 30 °. The locus of light emitted from the light emitting element 3 in the light emitting device 10b also follows the same locus as in the above (A) to (C) in the light emitting device 10. Further, a part of the light emitted from the light emitting element 3 and the light whose wavelength is converted by the phosphor 43 is refracted into the air in accordance with Snell's law at the interface between the side surface portion 42a of the second resin body 42 and the air. Released. Here, by reducing the angle θ formed between the side surface portion 42a and the substrate 1, it is possible to increase the proportion of light incident on the interface between the side surface portion 42a and air at an angle greater than the critical angle. Therefore, it is possible to start up light without causing loss due to Fresnel reflection at the interface between the side surface portion 42a and air.

  In addition, as will be described later, in the light emitting device 10b, since the light exit surface 42c of the second resin body 42 is a scattering surface, the light extraction efficiency is higher than when the light exit surface 42c is a flat surface. Can be increased.

(Comparison of light extraction efficiency)
FIG. 6 is a graph comparing the light extraction efficiency of the light emitting device 10b according to the present embodiment and the conventional light emitting device 100. In FIG. The triangular plot of FIG. 6 analyzes the relationship between the light extraction efficiency obtained from the light emitting device 100 when the angle (θ ′) between the reflector 106 and the substrate 101 is changed in the light emitting device 100 of FIG. It is the result. The reflectance of the reflector 106 was analyzed as 90%.

  On the other hand, the square plot (θ ≦ 90) in FIG. 6 is the result of analyzing the relationship between the angle (θ) formed by the second resin body 42 and the substrate 1 and the light extraction efficiency obtained from the light emitting device 10b. . The second resin body 42 is a commonly used silicone resin and has a refractive index of 1.4. Further, the substrate 1 was made of a white ceramic material, and the reflectance was 90% on the light emitting element mounting surface 1a.

  From the graph of FIG. 6, it can be seen that the light emitting device 10 in which the side surface portion 42 a of the second resin body 42 is exposed has higher light extraction efficiency than the conventional light emitting device 100. Furthermore, it can be seen that the light extraction efficiency increases as the angle θ becomes smaller than 90 ° (the sharper the angle becomes). This is because the smaller the angle θ formed between the side surface portion 42a of the second resin body 42 and the substrate 1, the greater the proportion of light incident on the interface between the side surface portion 42a and air at an angle greater than the critical angle. . Further, when the angle θ is an acute angle, the size of the substrate 1 (the area of the light emitting element mounting surface 1a) can be made smaller than when the angle θ is an obtuse angle.

  In addition, in the square plot (θ> 90) in FIG. 6, the light extraction efficiency of the light emitting device 10b according to this embodiment and the configuration where the angle θ is an obtuse angle and the conventional light emitting device 100 are compared. From the graph of FIG. 6, it can be seen that the light emitting device 10 b in which the side surface portion 42 a of the second resin body 42 is exposed has higher light extraction efficiency than the conventional light emitting device 100 even when the angle θ is an obtuse angle. Further, it can be seen that the light extraction efficiency increases as the angle θ is larger than 90 ° (closer to 180 °).

  As described above, the light emitting device 10b according to the present embodiment in which neither the reflector 106 nor the frame is present has significantly higher light extraction efficiency from the light emitting device 10b than the light emitting device 100 in which the reflector 106 is present. Further, the light extraction efficiency is higher than that of the conventional light emitting device 100 regardless of the angle θ of the light emitting device 10b. Specifically, the light extraction efficiency when the angle θ is 90 ° is minimized, and the light extraction efficiency increases as the angle θ becomes smaller than 90 ° or as the angle θ becomes larger than 90 °. Yes.

  Further, as apparent from a comparison between FIG. 3 and FIG. 6, the light emitting device 10 b in which the light emitting surface 42 c is an uneven surface has a higher light extraction efficiency than the light emitting devices 10 a and 10 b in which the light emitting surface 42 c is a flat surface. Is high.

(Example of manufacturing light-emitting device 10b)
The light emitting device 10b of the present embodiment can be manufactured as follows, for example.

  The light emitting element 3 is mounted on the substrate 1, the electrode 2 provided on the same surface of the substrate 1 and the light emitting element 3 are wire-bonded, and are electrically connected to each other through the wiring 11. Next, the first resin body 41 containing the phosphor 43 is quantitatively applied onto the light emitting element 3 using a dispenser or the like. Thereafter, the first resin body 41 containing the phosphor 43 is cured by a method such as heating, and the light emitting element 3 is sealed with the first resin body 41.

  Next, a liquid second resin body 42 having translucency is quantitatively applied to the surface of the first resin body 41, and the first resin body 41 is covered with the second resin body 42. The shape (angle θ) of the side surface portion 42 a of the second resin body 42 affects the light extraction efficiency of the light emitting device 10. For this reason, it is preferable that the second resin body 42 be precisely manufactured by mold molding or the like.

  As another method for forming the second resin body 42, a single sheet-like second resin body 42 having a concavo-convex shape formed on the surface is formed. Next, after placing the planar sheet-like second resin body 42 on the first resin body 41 containing the phosphor 43, the side surface 42 a and the substrate 1 are bent by bending the side surface of the second resin body 42. Is determined. In this way, the second resin body 42 can also be formed.

  Finally, the liquid second resin body 42 is cured by means such as heating to join the first resin body 41 containing the phosphor 43 and the second resin body 42 not containing the phosphor 43. . In this way, the light emitting device 10 can be manufactured.

  As described above, according to the light emitting device 10b, the light emission surface 42c of the second resin body 42 is a scattering surface. As a result, the total reflection condition is broken at the light exit surface 42 c of the second resin body 42. For this reason, it is possible to take out the light that has not been taken out by total reflection at the interface between the light emitting surface 42c of the second resin body 42 and the outside (for example, air) out of the emitted light from the light emitting element 3. Become. Therefore, the light extraction efficiency can be further increased.

  More specifically, according to the light emitting device 10b, the light emission surface of the sealing resin is an uneven surface. Thereby, the total reflection condition is broken by the cone or pyramid formed on the light emitting surface 42c of the second resin body 42. For this reason, it becomes possible to take out the light which was not taken out by the total reflection in the interface of the light-projection surface 42c and the exterior (for example, air) among the emitted light from the light emitting element 3. FIG. Therefore, the light extraction efficiency can be further increased.

  Furthermore, in the light emitting device 10b, since the light emitting surface 42c is an uneven surface, the amount of resin constituting the sealing body 4 can be reduced as compared with the case where no cone or pyramid is formed on the light emitting surface. Can do. That is, it is possible to reduce the thickness of the sealing body 4 and hence the light emitting device 10b, and to reduce the manufacturing cost of the light emitting device 10b.

  As described above, in the light emitting device 10b of the present embodiment, neither a reflector nor a frame provided in a general light emitting device exists. Thereby, irrespective of the angle θ formed by the side surface portion 42a of the second resin body 42 and the light emitting element mounting surface 1a of the substrate 1. Reflection loss is reduced and high light extraction efficiency can be obtained. Moreover, by making the light exit surface 42c an uneven surface, the light extraction efficiency can be made higher than when the light exit surface 42c is a flat surface.

  By mounting such a light emitting device 10b on various lighting devices, it is possible to realize a lighting device with high light extraction efficiency. For example, the light emitting device 10b can be mounted on a light bulb type lighting device shown in FIG. FIG. 7 is a schematic diagram illustrating a configuration of the illumination device 20 including the light emitting device 10 of FIG. The illumination device 20 has a configuration in which a globe 21, a light emitting unit 22 including the light emitting device 10b, and a base 23 are arranged in this order.

  The globe 21 has a dome shape, and houses the light emitting device 10b provided in the light emitting unit 22 inside. The globe 21 has a function of transmitting light emitted from the light emitting device 10b and a function of protecting the light emitting unit 22 (particularly the light emitting device 10b) by covering the light emitting unit 22. The globe 21 can be formed from, for example, transparent or light diffusing glass or synthetic resin.

  The light emitting unit 22 is a main body of the lighting device 20. A globe 21 is attached to one end (upper end) of the light emitting unit 22, and a base 23 is attached to the other end (lower end). A light emitting device 10 b is mounted on the upper end surface of the light emitting unit 22. On the other hand, a power supply module (not shown) is provided inside the light emitting unit 22. The power supply module supplies power to the light emitting device 10b and also controls the lighting state (light emission amount, etc.) of the light emitting element.

  When the light emitting device 10b includes an LED as a light emitting element (light source), the amount of heat generated is particularly large. For this reason, it is preferable that the light emission part 22 (especially exterior part) is comprised from the heat sink. For example, the light emitting unit 22 is preferably made of a metal having good thermal conductivity such as aluminum (Al), copper (Cu), iron (Fe), nickel (Ni), or an alloy thereof. The light emitting unit 22 is not limited to such a metal or alloy, and may be made of, for example, aluminum nitride (AlN), silicone carbide (SiC), high thermal conductive resin, or the like. Accordingly, the light emitting unit 22 can effectively dissipate heat generated from the light emitting device 10b to the outside.

  The base 23 is a metal fitting for external connection, for example, a general E26 type metal fitting. Thereby, the illuminating device 20 can be attached to a socket provided on the ceiling or the like.

  With such a configuration, in the lighting device 20, when the base 23 is attached to a socket of a commercial power source (external power source) or the like, the light emitting element of the light emitting device 10b is turned on. Light from the light emitting element is transmitted through the globe 21 and diffused by the globe 21. Thereby, substantially the entire globe 21 is brightened, and light having substantially uniform luminance is emitted to the outside. Since the lighting device 20 includes the light emitting device 10b, the lighting device 20 with high light extraction efficiency can be provided without increasing the thickness of the light emitting device 10b.

[Supplement]
The light emitting device according to the present invention can also be expressed as follows.

  (1) At least one light-emitting element is provided on the upper surface of the substrate on which the electrode is formed, the light-emitting element and the electrode are electrically connected, and the light-emitting element is connected to the first translucent resin. In the light-emitting device sealed with a body, the surface and side surfaces of the first translucent resin body (second resin body 42) facing the light-emitting surface of the light-emitting element are in contact with air. Light emitting device.

  According to the above configuration, since the light emitting element on the substrate is sealed only by the first translucent resin body, the light emitted from the light emitting element is generated between the first translucent resin body and the air. Extracted by the refraction effect that occurs at the interface. Since there are no members such as reflectors and frames, there is no reflection loss due to them, and the loss of light emitted from the light emitting element is only the loss due to Fresnel reflection at the interface between the first translucent resin body and air. Can be suppressed. As a result, a light emitting device with high light extraction efficiency can be obtained.

  (2) In the light emitting device of the present invention, at least one light emitting element is provided on the upper surface of the substrate on which the electrode is formed, the light emitting element and the electrode are electrically connected, and the light emitting element is It is sealed with a second phosphor resin body (first resin body 41) in which phosphors that are wavelength conversion materials are mixed, and the second phosphor resin body is sealed with a first translucent resin body. In the light emitting device that is stopped, one surface of the first translucent resin body is in close contact with the second phosphor resin body, and the surface of the first translucent resin body that faces the second phosphor resin body and The side faces are in contact with air.

  According to the above configuration, the light emitted from the light emitting element and the light whose wavelength has been converted by the phosphor that is the wavelength conversion material are extracted by the refracting action that occurs at the interface between the first translucent resin body and air. Is done. Since there are no members such as reflectors and frames, there is no reflection loss due to them, and the loss of light emitted from the light emitting element is only the loss due to Fresnel reflection at the interface between the first translucent resin body and air. Can be suppressed. As a result, a light emitting device with high light extraction efficiency can be obtained.

  (3) In the light emitting device of the present invention, even if the resin (resin in which the phosphor is mixed) constituting the second phosphor resin body and the first translucent resin body are the same material, Good.

  According to the above configuration, since the resin mixed with the phosphor in the second phosphor resin body and the first translucent resin body are the same material, the second phosphor resin body and the first phosphor resin body are the same. There is no light interface at the interface with the translucent resin body. For this reason, the light emitted from the light emitting element and the light whose wavelength has been converted by the phosphor can be taken out into the air without causing a loss due to Fresnel reflection at the interface. As a result, a light emitting device with high light extraction efficiency can be obtained.

  (4) Moreover, in the light-emitting device of this invention, it is preferable that the surface of the 1st translucent resin body is a cone shape or a pyramid shape, and the 1 or several uneven | corrugated shape is formed.

  According to the above configuration, since the total reflection condition is broken by the conical or pyramidal uneven shape on the surface of the first translucent resin body, the total reflection on the surface of the first translucent resin body and the air interface Light that has not been extracted can be extracted into the air. Further, since there is no member such as a reflector or a frame, there is no reflection loss due to them, and the loss of light emitted from the light emitting element is conical or pyramidal unevenness on the surface of the first translucent resin body. Only loss due to Fresnel reflection at the shape and air interface can be suppressed. Moreover, since the total reflection condition is broken by the conical or pyramidal uneven shape, it can be made thinner than the conventional dome shape, and the amount of the first translucent resin body used can be reduced. It is possible to reduce, that is, cost can be reduced. As a result, a light-emitting device that is thin, has high light extraction efficiency, and is low in cost can be obtained.

  (5) Moreover, the illuminating device of this invention mounts the light-emitting device in any one of said (1)-(4), It is characterized by the above-mentioned.

  According to the above configuration, the light emitting device capable of taking out light emitted from the light emitting element and light converted in wavelength by the phosphor into the air with high light extraction efficiency is mounted. Therefore, the function can be given to the lighting device.

  The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope shown in the claims, and embodiments obtained by appropriately combining technical means disclosed in different embodiments. Is also included in the technical scope of the present invention.

  The light emitting device of the present invention can be mounted on various lighting devices including lighting fixtures. In particular, an illuminating device equipped with the light emitting device of the present invention is preferably applied to the high-luminance lighting field (dimming and toning at a total luminous flux of 2000 to 5000 lm and a color temperature of 2500 to 6500 K).

DESCRIPTION OF SYMBOLS 1 Board | substrate 1a Light emitting element mounting surface 2 Electrode 3 Light emitting element 4 Sealing body (sealing resin)
DESCRIPTION OF SYMBOLS 10 Light-emitting device 10a Light-emitting device 10b Light-emitting device 20 Illuminating device 41 1st resin body (1st resin)
42a Side part 42 2nd resin body (2nd resin)
42b Bottom surface 42c Light exit surface (scattering surface / uneven surface)
43 phosphor

Claims (6)

In a light emitting device including a substrate, a light emitting element mounted on the substrate, and a sealing resin for sealing the light emitting element,
The bottom portion of the sealing resin is in contact with the light emitting element mounting surface of the substrate,
A side surface portion of the sealing resin is exposed.   2. The light emitting device according to claim 1, wherein the sealing resin has a light emitting surface that emits light emitted from the light emitting element as a scattering surface that scatters light emitted from the light emitting element.   The light-emitting device according to claim 2, wherein the scattering surface is a concavo-convex surface on which a single or a plurality of cones or pyramids are formed. The sealing resin includes a first resin that seals the light emitting element, and a second resin that covers the first resin,
4. The light emitting device according to claim 1, wherein at least one of the first resin and the second resin includes a phosphor that converts a wavelength of light emitted from the light emitting element.   The light emitting device according to claim 4, wherein the first resin and the second resin each include a resin of the same material.   The illuminating device provided with the light-emitting device of any one of Claims 1-5.

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