JP2019164376A - Optical component and manufacturing method thereof - Google Patents

Abstract

To provide an optical component in which a decrease in luminance and intensity is secured.SOLUTION: An optical component according to an embodiment includes: a translucent member 1 having an upper surface, a lower surface, and side surfaces; and a light reflecting member 2 provided on the side of the translucent member 1 so as to surround the translucent member 1. The light reflecting member 2 is made of ceramics containing a plurality of gaps, and in a cross section crossing the translucent member 1 and the light reflecting member 2, the plurality of gaps are unevenly distributed in the vicinity of the translucent member 1.SELECTED DRAWING: Figure 1A

Description

  The present invention relates to an optical component and a method for manufacturing the optical component.

  In the optical component described in Patent Document 1, a light-transmitting member is fixed to a light extraction member such as alumina via a metal film (see, for example, FIG. 2 of Patent Document 1).

JP2015-019013A

  In such an optical component, the luminance may decrease due to deterioration of the metal film.

  An optical component according to an aspect of the present invention includes a translucent member having an upper surface, a lower surface, and a side surface, and a light reflecting member provided on a side of the translucent member so as to surround the translucent member. The light reflecting member is made of ceramics including a plurality of gaps, and the plurality of gaps are unevenly distributed in the vicinity of the light transmissive member in a cross section crossing the light transmitting member and the light reflecting member.

  An optical component manufacturing method according to an aspect of the present invention includes a step of preparing a light-transmitting member having an upper surface, a lower surface, and a side surface, and an inorganic material on a side of the light-transmitting member so as to surround the light-transmitting member. The step of forming a molded body including the light reflecting powder, the light reflecting member including the sintered body of the light reflecting powder, and the light transmitting member are integrally formed, and cross the light transmitting member and the light reflecting member. Sintering the molded body so that a plurality of voids are unevenly distributed in the light reflecting member in the vicinity of the light transmitting member in one cross section.

  According to said optical component, it can be set as the optical component which reduced the fall of the brightness | luminance and ensured intensity | strength.

  In addition, according to the above-described method for manufacturing an optical component, it is possible to easily manufacture an optical component that reduces the decrease in luminance and ensures strength.

FIG. 1A is a top view of the optical component according to the first embodiment. 1B is a cross-sectional view taken along line 1B-1B in FIG. 1A. FIG. 2A is a view for explaining the method of manufacturing the optical component according to the first embodiment. 2B is a cross-sectional view taken along line 2B-2B in FIG. 2A. FIG. 3A is a view for explaining the method of manufacturing the optical component according to the first embodiment. 3B is a cross-sectional view taken along line 3B-3B in FIG. 3A. FIG. 4A is a view for explaining the method of manufacturing the optical component according to the first embodiment. 4B is a cross-sectional view taken along line 4B-4B of FIG. 4A. FIG. 5A is a view for explaining the method of manufacturing the optical component according to the first embodiment. 5B is a cross-sectional view taken along line 5B-5B in FIG. 5A. FIG. 6A is a view for explaining the method of manufacturing the optical component according to the first embodiment. 6B is a cross-sectional view taken along line 6B-6B in FIG. 6A. FIG. 7A is a view for explaining the method of manufacturing the optical component according to the first embodiment. 7B is a cross-sectional view taken along line 7B-7B in FIG. 7A. FIG. 8A is a secondary electron image obtained by observing the optical component from the upper surface side. FIG. 8B is an SEM image in area A of FIG. 8A. FIG. 8C is an SEM image in region B of FIG. 8A. FIG. 9 is a diagram of a light-emitting device that combines an optical component and a light-emitting element according to the second embodiment. FIG. 10A is a top view of a light-emitting device that combines an optical component and a light-emitting element according to the third embodiment. 10B is a cross-sectional view taken along line 10B-10B in FIG. 10A. FIG. 11 is a photograph of the optical component according to the example observed from the upper surface side.

  A mode for carrying out the present invention will be described below with reference to the drawings. However, the form shown below is for embodying the technical idea of the present invention, and does not limit the present invention. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation.

<First Embodiment>
FIG. 1A shows a top view of the optical component 10 according to the first embodiment. 1B is a cross-sectional view taken along line 1B-1B in FIG. 1A.

  The optical component 10 includes a translucent member 1 having an upper surface, a lower surface, and a side surface, and a light reflecting member 2 provided on the side of the translucent member 1 so as to surround the translucent member 1. The light reflecting member 2 is made of ceramics including a plurality of gaps, and the plurality of gaps are unevenly distributed in the vicinity of the light transmissive member 1 in a cross section crossing the light transmitting member 1 and the light reflecting member 2.

  According to the optical component 10, the transmittance of the light reflecting member 2 can be reduced, and the optical component 10 with sufficient strength can be obtained. Hereinafter, this point will be described.

  In the conventional optical component, a metal film is provided between the translucent member and the light extraction member, and light directed from the translucent member to the light extraction member is reflected by the metal film and extracted. However, for example, when mounted on a car, the metal film may deteriorate due to salt damage or the like due to the car being placed on the coast. In this case, the light extraction efficiency decreases. Therefore, it is conceivable to provide a light reflecting member made of ceramics around the translucent member without using a metal film. In this case, it is conceivable to increase the porosity of the light reflecting member in order to suppress the transmission of light from the light transmitting member to the light reflecting member and efficiently reflect the light, but the overall porosity is increased. Then, the intensity | strength of a light reflection member will fall.

  Therefore, the inventor of the present application uses ceramics in which a plurality of voids are unevenly distributed in the vicinity of the translucent member 1 in a cross section crossing the translucent member 1 and the light reflective member 2 as the light reflecting member 2. That is, as the light reflecting member 2, in order from the side closer to the translucent member 1, the first region 2a having the first porosity and the second region 2b having the second porosity having a lower porosity than the first porosity, The ceramic which has is used. Thereby, the intensity | strength as the optical component 10 can be ensured in the 2nd area | region 2b, reducing that the light from the translucent member 1 permeate | transmits in the 1st area | region 2a. Therefore, it is possible to obtain the optical component 10 in which the decrease in luminance is reduced and the strength is ensured.

  Hereinafter, the components of the optical component 10 will be described.

(Translucent member 1)
The translucent member 1 is made of a material that transmits light from a light emitting element or the like. As the translucent member 1, a material that does not melt at the sintering temperature of the light reflecting member 2 can be used. In the present embodiment, ceramics containing a phosphor (hereinafter referred to as “phosphor ceramics”) are used as the translucent member 1. In the phosphor ceramic, light easily scatters in the inside thereof, so that the light reflecting member 2 is easily hit by light. Therefore, the effect of suppressing the transmission of light in the first region 2a becomes more remarkable. Furthermore, the 2nd area | region 2b with a low porosity is excellent in heat dissipation compared with the 1st area | region 2a with a high porosity among the light reflection members 2. FIG. Therefore, the heat generated in the phosphor can be effectively dissipated in the second region 2b through the first region 2a. Here, although the phosphor ceramic is used as the translucent member 1, a phosphor single crystal may be used. Even in this case, according to the present embodiment, the heat from the phosphor can be efficiently dissipated to the second region 2b of the light reflecting member 2.

  Although another light-transmitting member may be interposed between the light-transmitting member 1 and the light-reflecting member 2, in this embodiment, the light-transmitting member 1 is in contact with the side surface of the light-reflecting member 2. . That is, the translucent member 1 and the light reflecting member 2 are in direct contact with each other without any other member. Thereby, since light is not absorbed by another member, the light extraction efficiency is improved. Moreover, when the fluorescent substance is contained in the translucent member 1, it can make it easy to dissipate the heat which arises with a fluorescent substance compared with the case where it passes through another member.

In the present embodiment, as the phosphor ceramic, a ceramic containing a phosphor and a binder made of an inorganic material is used. Specifically, a YAG (Yttrium Aluminum Garnet) phosphor is used as the phosphor, and aluminum oxide is used as the binder. The light reflecting member 2 is made of a material containing aluminum oxide as a main component.
Thus, when the binder contained in the translucent member 1 contains the same material as the light reflecting member 2, the adhesion between the translucent member 1 and the light reflecting member 2 can be increased.

  As the phosphor, it is preferable to use a phosphor having a linear expansion coefficient close to that of the light reflecting member 2 in order to increase the adhesion between the light transmitting member 1 and the light reflecting member 2. When a material containing aluminum oxide as a main component is used as the light reflecting member 2, examples of the phosphor having a linear expansion coefficient close to this include YAG phosphors. The YAG phosphor includes, for example, those in which at least a part of Y is substituted with Tb and those in which at least a part of Y is substituted with Lu. In addition, the YAG phosphor may contain Gd or Ga in the composition. When a YAG-based phosphor is used for the phosphor and aluminum oxide is used for the light reflecting member 2, the binder contained in the light transmitting member 1 is preferably aluminum oxide for the same reason. In addition, for example, YAG or yttrium oxide not containing an activator can be used as the binder. Since the phosphor content can be adjusted by including the binder, it is possible to easily adjust the color of the light emitted from the translucent member 1.

  In addition, as the translucent member 1, sapphire not containing a phosphor, translucent alumina, quartz, or the like can be used. Even when the light transmitting member 1 does not contain a phosphor, the light scattered by the light transmitting member 1 can be efficiently reflected by the first region 2a of the light reflecting member 2, and the second light reflecting member 2 can be The strength of the optical component 10 can be ensured in the region 2b.

  In this embodiment, the translucent member 1 is a quadrangular prism, and the upper surface is a rectangle long in one direction. In addition, a cylinder, a polygonal column, a polygonal frustum, and a truncated cone can be used, and among these, a cylinder or a truncated cone is preferable. In the case of a cylinder or a truncated cone, the width of the first region 2a (the length of the portion where the straight line passing through the center of the circular translucent member 1 and the first region 2a overlaps when viewed from above) is constant. Since it can be made closer, it is possible to easily reduce unevenness in light emission.

(Light reflecting member 2)
The light reflecting member 2 is provided on the side of the translucent member 1 so as to surround the translucent member 1. In other words, the light reflecting member 2 is provided with a through hole penetrating in the vertical direction, and the light transmissive member 1 is provided inside the through hole. The upper surface of the light transmissive member 1 and the lower surface of the light transmissive member 1 are exposed from the light reflecting member 2.

  The light reflecting member 2 is made of ceramics including a plurality of voids. A plurality of voids are unevenly distributed in the vicinity of the translucent member 1 in a cross section that crosses the translucent member 1 and the light reflecting member 2. That is, the first region 2 a having the first porosity and the second region 2 b having the second porosity having a lower porosity than the first porosity are sequentially provided from the side close to the translucent member 1. If the overall porosity of the light reflecting member is lowered, the strength is increased, but the transmittance is lowered. This is because the interface inside the light reflecting member 2 is reduced, so that the light incident on the light reflecting member 2 easily propagates. Further, if the overall porosity of the light reflecting member is increased, the transmittance is lowered but the strength is lowered. On the other hand, in the present embodiment, by providing the first region 2a having a relatively high porosity so as to be in contact with the translucent member 1, light is efficiently reflected in the vicinity of the translucent member 1. . Further, by providing the second region 2b having a relatively low porosity outside the first region 2a, the strength is improved and the heat dissipation is improved. In the present specification, the first region 2a and the second region 2b are in the same member and have the same composition. That is, it is not the 1st field 2a and the 2nd field 2b in this specification that different members are joined. Thereby, peeling between the 1st field 2a and the 2nd field 2b can be made hard to occur rather than the case where different members are joined.

  The width of the first region 2a (the length of the portion where the straight line passing through the central portion of the optical component 10 and the first region 2a overlap each other as viewed from above) is the second region in the straight line on the entire circumference of the translucent member 1. The width is preferably narrower than the width of 2b (the length of the portion where the straight line passing through the center of the optical component 10 and the second region 2b overlap each other as viewed from above). Thereby, the intensity | strength of the light reflection member 2 can be ensured easily.

  The width of the first region 2a is preferably set in a range of 50 μm to 300 μm, and more preferably set in a range of 100 μm to 250 μm. By setting in the range of 50 μm or more, it is possible to easily reduce the transmission of light toward the light reflecting member 2. In addition, by setting in the range of 300 μm or less, when using a member containing a phosphor as the translucent member 1, the distance to the second region 2b having a low porosity and high heat dissipation can be reduced. It is possible to easily dissipate heat from the phosphor.

  Although it is preferable to make the width of the first region 2a constant around the entire periphery of the translucent member 1, it may be different as in this embodiment. As an example, when the optical component 10 is viewed from above, the outer shape of the translucent member 1 and the outer shape of the light reflecting member 2 are both rectangular, the center portions of the two are coincident, and one constituent side of each of the two is Assume that they are parallel. Here, a distance between a portion where a straight line (hereinafter referred to as “L1”) passing through the central portion of the translucent member 1 and perpendicular to one side of the translucent member 1 and the first region 2a overlaps is defined as “D1a”. , The distance of the portion where L1 and the second region 2b overlap is “D1b”, and a straight line (hereinafter referred to as “L2”) passing through the central portion of the translucent member 1 and perpendicular to L1 and the first region 2a. The distance between the overlapping portions is “D2a”, and the distance between the overlapping portions of L2 and the second region 2b is “D2b”. In this case, for example, if D1a is larger than D2a, D1b is preferably larger than D2b. If the width of the first region 2a is large, it is easy to reflect light in the first region 2a, but the strength tends to decrease. However, even in such a case, a decrease in strength as the optical component 10 can be suppressed by increasing the width of the second region 2b located in the vicinity of the first region 2a having a large width.

  As shown in FIG. 1B, the first region 2 a is preferably arranged from the upper end to the lower end of the side surface of the translucent member 1. Thereby, the transmission of light can be reduced over the entire side surface of the translucent member 1.

  As the light reflecting member 2, for example, zirconium oxide or titanium oxide can be used in addition to aluminum oxide. The light reflecting member 2 may include an additive made of a material different from the main material. Examples of the additive include yttrium oxide, zirconium oxide, boron nitride, lutetium oxide, and lanthanum oxide. According to these materials, the light transmittance of the light reflecting member 2 can be reduced.

  As described above, the first region 2a has a high porosity, and the second region 2b has a low porosity. For example, as will be described in the examples described later, by performing dark field observation of an optical component using an episcopic microscope, a region with a high porosity (first region) and a region with a low porosity (second region) Can be distinguished. In addition, the difference in porosity can be grasped by observing the light reflecting member 2 with a scanning electron microscope. In the light reflecting member 2, “the plurality of gaps are unevenly distributed near the light transmitting member 1” means, for example, the surface of the light transmitting member 1 when observed with a scanning electron microscope (SEM). And the density of the voids in the region sandwiched between the surface of the translucent member 1 and the 300 μm line is higher than the density of the voids in the outer region.

(Other)
When a member containing a phosphor is used as the light transmissive member 1, at least one of the upper surface of the light transmissive member 1, the upper surface of the light reflective member 2, the lower surface of the light transmissive member 1, and the lower surface of the light reflective member 2 is transparent. It is preferable that a light radiating member 3 is provided. In the first region 2a, there is a possibility that heat dissipation may be reduced due to the high porosity, but by providing the heat dissipation member 3, the heat generated in the light transmissive member 1 can be dissipated by the heat radiating member 3, and the light transmissive member 1 The temperature characteristics can be improved.
It is preferable that the heat dissipating member 3 is directly provided on at least one of the light transmitting member 1 and the light reflecting member 2 in order to improve heat exhaustion. However, when the heat radiating member 3 is provided with a filter 4 that reflects light traveling from the light transmissive member 1 toward the heat radiating member 3, the light transmissive member 1 and the light reflecting member 2 are indirectly provided via the filter 4. It may be provided.

  Next, a method for manufacturing the optical component 10 will be described with reference to FIGS. 2A to 7B.

  The manufacturing method of the optical component 10 includes a step of preparing the translucent member 1 having an upper surface, a lower surface, and a side surface, and light reflecting powder made of an inorganic material on the side of the translucent member 1 so as to surround the translucent member 1. The light reflecting member including the step of forming the molded body 2d including the sintered body of the light reflecting powder and the light transmitting member are integrally formed, and light reflection is performed in a cross section across the light transmitting member 1 and the light reflecting member 2. A step of sintering the molded body 2d so that a plurality of gaps are unevenly distributed in the vicinity of the translucent member 1 in the member 2.

  Thereby, the optical component 10 which reduced the fall of the brightness | luminance and ensured intensity | strength can be manufactured easily.

  Below, each process included in the manufacturing method of the optical component 10 is demonstrated. Here, about the same name and code | symbol, since it has shown the same or same member as what was demonstrated above, the overlapping description is abbreviate | omitted suitably.

(Process of preparing the translucent member 1)
First, the translucent member 1 having an upper surface, a lower surface, and side surfaces is prepared. In the present embodiment, a plurality of translucent members 1 are prepared. Thereby, since the optical component 10 provided with the some translucent member 1 can be obtained by one sintering, mass-productivity can be improved.

(Step of temporarily fixing the translucent member 1 to the support member 40)
Next, as shown in FIGS. 2A and 2B, the translucent member 1 is temporarily fixed to the support member 40. Thereby, it can suppress that the translucent member 1 falls in the process of forming the molded object 2d containing light reflection powder. Moreover, the distance of the adjacent translucent member 1 can be kept constant. In this embodiment, resin is provided only between the translucent member 1 and the support member 40, and the translucent member 1 is temporarily fixed to the support member 40. Thereby, in the process of removing the support member 40 from the translucent member 1 and the molded body 2d, the support member 40 can be easily removed without excessively applying force. Although it is preferable to use the support member 40 in consideration of workability, the support member 40 is not necessarily used.

  The material of the support member 40 can be selected according to the method used in the process of forming the molded body 2d. In the present embodiment, plaster is used as the support member 40 because the molded body 2d is formed by the slip casting method (a mud casting method).

  When the slip casting method is used when forming the molded body 2d, when the adhesive is applied to the entire upper surface of the gypsum, when the water contained in the slurry is absorbed into the gypsum, uneven absorption may occur and cracks may occur. is there. Therefore, here, by providing the resin only between the translucent member 1 and the support member 40, the uneven suction is suppressed. As the resin, for example, an acrylic resin can be used. Thereby, it can suppress that the component contained in resin enters into a slurry by the binder and resin contained in a slurry reacting.

  The translucent member 1 and the adjacent translucent member 1 are temporarily fixed to the upper surface of the support member 40 at a predetermined interval. The distance from the side surface of a certain translucent member 1 to the side surface of the adjacent translucent member 1 can be, for example, in the range of 1 mm or more and 10 mm or less. By setting it as 1 mm or more, it is easy to ensure the width | variety of the 2nd area | region 2b. By setting it as 10 mm or less, the number of the translucent members 1 contained in the optical component obtained by one sintering can be increased.

(Step of forming the molded body 2d containing the light reflecting powder)
Next, as shown in FIG. 3A, FIG. 3B, FIG. 4A, and FIG. 4B, a molded body 2d containing light reflecting powder made of an inorganic material is formed on the side of the light transmitting member 1 so as to surround the light transmitting member 1. To do. In the present embodiment, the molded body 2d is formed on each side surface of the translucent member 1 so as to surround each of the translucent members 1.

  The molded body 2d can be molded using a slip casting method, a doctor blade method (sheet molding method), a dry molding method, or the like. In the case of using the doctor blade method, specifically, a slurry in which an additive is mixed so as to cover the translucent member is applied in a sheet shape, and then the green sheet on which the slurry is applied in a sheet shape is dried to form a molded body. Can be formed. When using the dry molding method, specifically, the container may be filled with light reflecting powder made of an inorganic material so as to cover the translucent member, and the light reflecting powder may be pressed to form a molded body. it can.

  In the present embodiment, the molded body 2d is formed by a slip casting method. Specifically, first, as shown in FIGS. 3A and 3B, a frame body 50 that surrounds the plurality of translucent members 1 is disposed on the upper surface of the support member 40. Next, the slurry 2 c containing the light reflecting powder is applied to the inside of the frame body 50. Next, the water contained in the slurry 2c is sucked into the gypsum. Since gypsum is a material that absorbs moisture, it can be left at room temperature for several hours, for example. Thereby, the molded object 2d containing light reflection powder is formed. At this time, although the translucent member 1 and the molded body 2d are not completely fixed, they are molded in a certain shape (hereinafter, the translucent member 1 and the molded body 2d are in a certain shape). The molded product is called “composite”.) By using the slip casting method, molding can be performed without applying pressure. Moreover, the organic substance contained in a slurry can be decreased compared with a doctor blade method. Thereby, since a shaping | molding density can be made high, possibility that a crack will enter into the light reflection member 2 at the time of baking can be reduced.

  As the frame body 50, one having releasability and water repellency can be used. Thereby, it can reduce that the molded object 2d adheres to the inner surface of the frame 50. FIG. Moreover, since it can suppress that the water | moisture content contained in the slurry 2c is absorbed by the frame 50, the nonuniformity of the shaping | molding density of the molded object 2d in the frame 50 vicinity can be reduced. In the present embodiment, a frame 50 made of a fluororesin is used.

  The slurry 2c of this embodiment contains light reflecting powder containing aluminum oxide and yttrium oxide, a dispersant, a binder, and pure water. The thickness of the slurry 2 c is preferably larger than the thickness of the translucent member 1. That is, it is preferable that the slurry 2 c covers not only the side surface of the translucent member 1 but also the upper surface. Since it is difficult to make the translucent member and the slurry have the same thickness, the translucent member may be thicker than the slurry. In this case, in the step of removing a part of the obtained optical component 10 described later, since the force is applied only to the light transmissive member during polishing or the like, the light transmissive member may be damaged. Therefore, in the present embodiment, by increasing the thickness, it is possible to suppress the force from being applied only to the translucent member 1. The thickness of the slurry 2c is preferably 2 to 4 times the thickness of the optical component 10. By setting it to 2 times or more, peeling between the translucent member 1 and the molded body 2d can be suppressed, so that the support member 40 can be easily removed from the translucent member 1 and the molded body 2d. Moreover, by making it 4 times or less, in the process of removing a part of the obtained optical component 10, the thickness of the removed optical component 10 can be made small.

(Step of removing the support member 40)
Next, as shown in FIGS. 4A and 4B, the support member 40 is removed from the translucent member 1 and the molded body 2d. The translucent member 1 and the support member 40 are temporarily fixed with resin, but the area of the lower surface of the translucent member 1 is relatively small. Moreover, the translucent member 1 and the molded body 2d are integrally molded to some extent. For these reasons, the translucent member 1 and the support member 40 can be separated without causing the resin to be softened by heating or being pulled excessively. In the present embodiment, the frame body 50 is removed from the upper surface of the support member 40, and then the composite is removed from the support member 40.

(Degreasing process)
Next, in order to remove organic substances (dispersant and binder) contained in the composite, heating is performed at a temperature lower than the temperature at which the compact 2d is sintered. The degreasing step can be performed, for example, in a nitrogen atmosphere or an air atmosphere. Heating for degreasing is preferably performed for 3 hours or more in order to reliably remove organic substances. In this embodiment, the degreasing step and the step of sintering the molded body 2d are performed in separate steps. However, in the step of sintering the molded body 2d, degreasing is performed at a low temperature for a certain time, and the temperature is kept as it is. The molded body 2d may be sintered by increasing the height. Note that this step is not necessary when a dry molding method is used in the step of forming the molded body 2d.

(Step of sintering the molded body 2d)
Next, the light reflecting member and the light transmitting member including the sintered body of the light reflecting powder are integrally formed, and the light reflecting member 1 in the light reflecting member 2 is a cross section across the light transmitting member 1 and the light reflecting member 2. The molded body 2d is sintered so that a plurality of voids are unevenly distributed in the vicinity of. Such a light reflecting member 2 can be adjusted by the sintering temperature and the degree of pressurization during sintering. Here, as shown in FIGS. 5A and 5B, by sintering the molded body 2d without pressing, the optical component 10 in which the sintered body of the light reflecting powder and the translucent member 1 are integrated is obtained. . Thereby, it can be set as the optical component 10 containing the light reflection member 2 which has the 1st area | region 2a and the 2nd area | region 2b in order from the translucent member 1 side. The first region 2a and the second region 2b are considered to be formed for the following reason. When the molded body 2d is sintered, the light reflecting powder shrinks while being combined with other light reflecting powders nearby. At this time, since the light reflecting powder is in the entire circumference in the region far from the light transmitting member 1, the light reflecting powder is easily combined with each other and it is difficult to form pores. However, in the region near the light transmitting member 1, the light reflecting powder is outside. Therefore, the light reflecting powders cannot be bonded to each other and pores are easily formed. By sintering without pressing, since the sintering is completed while maintaining the state where the light reflecting powders are separated from each other, the porosity of the light reflecting member 2 is high in the vicinity of the light transmitting member 1. It is considered to be.

  Formed around the translucent member 1 made of ceramics containing a phosphor is a molded body 2d having a light reflecting powder containing 95.2 wt% aluminum oxide and 4.8 wt% yttrium oxide by a slip casting method. FIG. 8A shows a secondary electron image obtained by observing the optical component 10 sintered without pressing thereafter from the upper surface side. When measuring the secondary electron image, a carbon film is formed by vapor deposition in order to measure the secondary electron image. The first region 2a in FIG. 8A is blacker than the second region 2b due to the voids included in the first region 2a. FIG. 8B shows an SEM image of area A in FIG. 8A, and FIG. 8C shows an SEM image of area B in FIG. 8A. In FIG. 8B, many pores exist in the vicinity of the translucent member 1, whereas in FIG. 8C, there are almost no pores. As can be seen from these results, it can be confirmed that the light reflecting member 2 having regions having different porosity can be formed by sintering the light reflecting powder without pressing and forming the light reflecting member 2. It was.

  When aluminum oxide is used as the light reflecting powder, the sintering temperature is preferably set to 1200 ° C. or higher and 1800 ° C. or lower, and more preferably set to 1400 ° C. or higher and 1500 ° C. or lower. By setting the temperature to 1200 ° C. or higher, the strength as the light reflecting member 2 can be ensured. Moreover, the possibility that the translucency of the light reflection member 2 becomes high can be reduced by setting to 1800 degrees C or less.

  In the present embodiment, sintering is performed in an air atmosphere. For example, the sintering time is preferably set in the range of 30 minutes to 5 hours, more preferably in the range of 2 hours to 4 hours. By setting it as 30 minutes or more, the strength of the light reflecting member 2 can be easily secured. Moreover, it can avoid taking time more than necessary by setting it as 5 hours or less.

(Step of removing a part of the optical component 10)
At this stage, the upper surface of the translucent member 1 is covered with the light reflecting member 2. Therefore, as shown in FIGS. 6A and 6B, a part of the optical component 10 is removed from the upper surface side of the optical component 10 until the translucent member 1 is exposed. An example of a method for removing a part of the optical component 10 is polishing. Although this embodiment removes only from one side, in order to remove the deposits on the lower surface of the translucent member 1 and the lower surface of the light reflecting member 2, a part of the optical component 10 is further removed from the lower surface side. May be. In the present embodiment, the translucent member 1 is in a polygonal column state, and there is no first region 2a in the portion in contact with the corner, or the width of the first region 2a in the portion in contact with the corner as viewed from above is other than that. This is narrower than the width of the first region 2a. Note that this step is not always necessary. For example, this step is omitted when an optical component in which the upper surface of the translucent member 1 is exposed from the upper surface of the light reflecting member 2 is obtained in the step of sintering the molded body 2d. May be.

(Process to divide into pieces)
Next, as shown in FIGS. 7A and 7B, the optical component 10 is separated into a plurality of optical components 10 so that the single optical component 10 includes one translucent member 1. For example, it can be separated into a plurality of optical components 10 using a blade. In this embodiment, one optical component 10 is divided into pieces so as to include one translucent member 1, but one optical component 10 is divided into pieces so as to include a plurality of translucent members 1. Also good. In addition, this step is not always necessary. For example, when the desired optical component 10 can be obtained by the step of sintering the molded body 2d or the step of removing a part of the optical component 10, this step is performed. It may be omitted.

Second Embodiment
In FIG. 9, the schematic diagram of the light-emitting device 100 which combined the optical component 20 and the light emitting element 60 which concern on 2nd Embodiment is shown. The optical component 20 is substantially the same as the items described in the optical component 10 except the items described below.

  In the optical component 20, the heat radiating member 3 is provided on both the lower surface of the translucent member 1 and the lower surface of the light reflecting member 2 through the insulating film 5 and the filter 4 in order from the translucent member 1 side. Although the heat radiating member 3 may be provided on one of the lower surface of the translucent member 1 or the lower surface of the light reflecting member 2, it is preferable to provide the heat radiating member 3 on both in consideration of heat dissipation as in this embodiment. Although a heat radiating member can be provided on at least one of the upper surface of the translucent member 1 and the upper surface of the light reflecting member 2, at least on the lower surface of the translucent member 1 and the lower surface of the light reflecting member 2 as in the present embodiment. It is preferable that the translucent heat radiating member 3 is provided on one side. When joining the heat radiating member 3 to the translucent member 1, the surface of the translucent member 1 may be flattened by polishing or the like. In this case, the first region 2a of the light reflecting member 2 is caused by a rate difference such as polishing. However, it may be removed in preference to the translucent member 1 or the second region 2b. As a result, the first region 2a may be partially recessed to form a groove. Therefore, if an attempt is made to provide a heat dissipation member on at least one of the upper surface of the translucent member and the upper surface of the light reflecting member, the brightness decreases because light is emitted from the groove formed in the first region above the light extraction side. There is a risk. Therefore, it is preferable to provide the heat radiating member 3 on at least one of the lower surface of the translucent member 1 and the lower surface of the light reflecting member 2 as in the present embodiment.

  In the optical component 20, heat generated in the translucent member 1 can be exhausted to the heat radiating member 3, so that deterioration of the translucent member 1 can be reduced.

  In the present embodiment, a filter that easily transmits light from the light emitting element 60 and reflects the fluorescence of the light transmitting member 1 is used as the filter 4. In the present embodiment, the light emitting element 60 that emits blue light is used, and the translucent member 1 includes a phosphor that emits yellow light when irradiated with blue light. Therefore, the filter 4 that easily transmits blue light and reflects yellow light is used.

  In the present embodiment, the filter 4 is bonded to the lower surface of the translucent member 1 and the lower surface of the light reflecting member 2 via the insulating film 5. In the present embodiment, the lower surface of the light transmissive member 1 and the lower surface of the light reflecting member 2 are polished in order to bond the filter 4 and the light transmissive member 1 and the like by the surface activation bonding method. At this time, a groove is formed in the vicinity of the boundary between the light transmitting member 1 and the light reflecting member 2 due to the difference in polishing rate between the light transmitting member 1 and the light reflecting member 2. If the surface activated bonding method is performed with the groove, a gap is formed between the light transmitting member 1 and the heat radiating member 3, and thus heat dissipation may be deteriorated. For this reason, the groove is filled with the insulating film 5 to reduce a decrease in heat dissipation.

  In this embodiment, aluminum oxide is used as the insulating film 5. In addition, for example, silicon oxide and titanium oxide can be used. The insulating film 5 is preferably formed with a film thickness sufficient to fill the groove in order to suppress a decrease in heat dissipation. In addition, in this embodiment, although the filter 4 and the translucent member 1 are joined by the surface activation joining method, you may join using an atomic diffusion joining method. In this case, a metal film is formed on each of the upper surface of the filter and the lower surface of the light transmissive member, and the metal film is bonded to each other to bond the filter and the light transmissive member.

  In the light emitting device 100 illustrated in FIG. 9, a laser element (Laser Diode, LD) is used as the light emitting element 60. The LD is disposed away from the optical component 20 so that the light from the LD passes through the translucent member 1 included in the optical component 20. When a phosphor ceramic containing a phosphor is used as the translucent member 1 and an LD is used as the light emitting element 60, the need for exhaust heat from the translucent member 1 increases. For this reason, the effect of the exhaust heat improvement by providing the heat radiating member 3 becomes more remarkable.

<Third Embodiment>
FIG. 10A shows a top view of a light emitting device 200 in which the optical component 30 according to the third embodiment and the light emitting element 60 are combined, and FIG. 10B shows a cross-sectional view taken along line 10B-10B in FIG. 10A. The optical component 30 is substantially the same as the items described in the optical component 10 except the items described below.

  The optical component 30 includes a plurality of translucent members 1 in one optical component 30. And the light reflection member 2 has the 1st area | region 2a around each translucent member 1, and has the 2nd area | region 2b in the outer side.

  In the light emitting device 200 shown in FIGS. 10A and 10B, a plurality of light emitting elements 60 are provided on the upper surface of the substrate 70. In the light emitting device 200, a light emitting diode (LED) is used as the light emitting element 60. Then, one optical component 30 is disposed on the upper surfaces of the plurality of light emitting elements 60 so that one light transmissive member 1 is positioned on the upper surface of one light emitting element 60. A light reflecting resin 80 is disposed around the light emitting element 60.

  In the light emitting device 200, light from one light emitting element 60 is arranged to pass through one light transmissive member 1, but light from two or more light emitting elements passes through one light transmissive member. An optical component and a light emitting element may be arranged.

<Example>
An optical component was manufactured by the following manufacturing method. First, as the translucent member 1, a rectangular parallelepiped phosphor ceramic having a short side of 500 μm, a long side of 1000 μm, and a height of 600 μm was prepared.
As the phosphor ceramic, a phosphor ceramic made of a sintered body containing a YAG phosphor and aluminum oxide was used.

  Next, a molded body 2d was formed by a slip casting method. Specifically, the molded body 2d was formed by the following method. First, the phosphor ceramic was placed on an acrylic resin sheet, and the acrylic resin was transferred to the lower surface of the phosphor ceramic by applying pressure. And the lower surface of fluorescent ceramics was temporarily fixed to the upper surface of the gypsum which is the supporting member 40 through resin. A frame 50 made of a Teflon (registered trademark) ring having an inner diameter of 30 mm was fixed to the upper surface of the support member 40 so as to surround the phosphor ceramic. Next, the slurry 2c was filled inside the frame 50 until the upper surface of the translucent member 1 was not visible. As the slurry 2c, a slurry containing 76.4% light reflecting powder, 0.7% dispersant, 2.4% binder, and 20.5% pure water was used. The light reflecting powder contains 95.2% by weight aluminum oxide and 4.8% by weight yttrium oxide. The dispersant includes an ammonium polycarboxylate-based material, and the binder includes an acrylic material. Then, the molded body 2d was formed by allowing the gypsum to absorb moisture contained in the slurry 2c by allowing it to stand overnight. That is, a composite was formed in which the phosphor ceramic and the molded body 2d were molded into a fixed shape.

  Next, after removing the frame 50, the composite was removed from the support member 40. At this time, the lower surface of the phosphor ceramic and the gypsum are temporarily fixed by an adhesive, but the composite can be removed from the support member 40 because the area of the lower surface of the phosphor ceramic is relatively small. The composite was degreased by heating at 700 ° C. for 3 hours under a nitrogen atmosphere. Next, it baked at 1450 degreeC for 2 hours. Thereby, the phosphor ceramic and the light reflecting member 2 were integrated, and an optical component in which the side surface and the upper surface of the phosphor ceramic were covered with the light reflecting member 2 was obtained. Next, the obtained optical component was polished from the upper surface side until the upper surface of the phosphor ceramic was exposed. As a result, an optical component in which the phosphor ceramic was surrounded by the light reflecting member 2 as viewed from above was obtained.

  About the obtained optical component, the photograph which performed dark field observation using the epi-illumination type | mold microscope is shown in FIG. In FIG. 11, the rectangular member at the center is the translucent member 1, and the light reflecting member 2 is on the outside thereof. In the light reflecting member 2, the black portion is the first region 2a, and the outer region is the second region 2b. As shown in FIG. 11, in the first region 2a, since the porosity is high, it appears black because there are many portions that appear as shadows due to the pores, and the second region 2b has a low porosity. It is thought that there are few shadows and no color.

  The optical component described in each embodiment can be used for lighting, a vehicular lamp, and the like.

DESCRIPTION OF SYMBOLS 1 ... Translucent member 2 ... Light reflection member 2a ... 1st area | region 2b ... 2nd area | region 2c ... Slurry 2d ... Molding body 3 ... Radiation member 4 ... Filter 5 ... Insulating film 10, 20, 30 ... Optical component 40 ... Support member DESCRIPTION OF SYMBOLS 50 ... Frame 60 ... Light emitting element 70 ... Substrate 80 ... Light reflective resin 100, 200 ... Light emitting device

Claims (12)

A translucent member having an upper surface, a lower surface and side surfaces;
A light reflecting member provided on a side of the light transmissive member so as to surround the light transmissive member,
The light reflecting member is made of ceramics including a plurality of voids,
The optical component according to claim 1, wherein the plurality of gaps are unevenly distributed in the vicinity of the light transmitting member in a cross section that crosses the light transmitting member and the light reflecting member.   The optical component according to claim 1, wherein the light reflecting member is provided in contact with a side surface of the light transmitting member.   3. The optical component according to claim 1, wherein the translucent member is made of a ceramic including a phosphor or a single crystal of the phosphor.   The optical component according to claim 1, wherein the light reflecting member includes aluminum oxide.   The optical component according to claim 4, wherein the translucent member is made of a phosphor ceramic containing a YAG phosphor or a single crystal of a YAG phosphor.   6. The translucent heat radiating member is directly or indirectly provided on at least one of the lower surface of the translucent member and the lower surface of the light reflecting member. The optical component described in 1. Preparing a translucent member having an upper surface, a lower surface, and a side surface;
Forming a molded body including light reflecting powder made of an inorganic material on the side of the light transmitting member so as to surround the light transmitting member;
The light reflecting member including the sintered body of the light reflecting powder and the light transmitting member are integrally formed, and the light reflecting member has a cross section across the light transmitting member and the light reflecting member. And sintering the molded body so that a plurality of voids are unevenly distributed in the vicinity.   The method of manufacturing an optical component according to claim 7, wherein in the step of sintering the molded body, the molded body is sintered without pressing.   The method for manufacturing an optical component according to claim 7 or 8, wherein, in the step of forming the molded body, the molded body is formed by a slip casting method.   10. The method according to claim 7, wherein in the step of preparing the light transmissive member, a phosphor ceramic containing a phosphor or a phosphor single crystal is prepared as the light transmissive member. Manufacturing method of optical components. In the step of preparing the translucent member, preparing a plurality of translucent members,
11. The method according to claim 7, wherein in the step of forming the molded body, the molded body is formed on a side of each of the light transmissive members so as to surround each of the plurality of light transmissive members. The manufacturing method of the optical component as described in any one of. Between the step of preparing the translucent member and the step of forming the molded body, the step of temporarily fixing the translucent member to the support member, and only between the translucent member and the support member Providing a resin and temporarily fixing the translucent member to the support member;
12. The method according to claim 7, further comprising a step of removing the support member from the translucent member and the molded body between the step of forming the molded body and the step of sintering the molded body. The manufacturing method of the optical component of any one of Claims 1.

Images