JP5849694B2 - Light emitting device and manufacturing method thereof - Google Patents

Description

  The present invention relates to a light emitting device and a method for manufacturing the same, and more particularly to a light emitting device including a phosphor and containing a sealing member for sealing a light emitting element and a method for manufacturing the same.

  Conventionally, a light emitting element such as a light emitting diode (LED) or a laser diode (LD) that emits primary light and a secondary light having a wavelength different from that of the primary light when excited by the primary light. In combination with a phosphor, light-emitting devices with various emission colors in addition to white have been developed. Particularly in recent years, such light-emitting devices have been attracting attention as low-power consumption and long-life lighting sources that can replace incandescent and fluorescent lamps. There is a need for improvement in light quality, such as reduction in the intensity distribution.

  For example, in Patent Document 1, a chip mounting portion on which a light emitting chip is mounted, a metal plate provided with a conductive via hole, an insulating layer provided at a constant thickness on the outer surface of the metal plate, a conductive via hole, and a light emitting chip. A high-power LED package including an external electrode that is electrically connected to each other has been proposed. In one example of this high-power LED package, the chip mounting portion has a trench that is recessed and formed at a certain depth from the upper surface of the metal plate, and the chip mounting portion includes a sealing material that covers the light emitting chip. Is provided. Then, the liquid resin as the sealing material is supplied so that the outer end is located up to the edge of the upper surface of the chip mounting portion, that is, the sharp end, the outer surface forms a curved surface by the surface tension, and the central portion is the upper side. It is formed in a dome shape that swells. Further, it is described that the sealing material preferably contains a phosphor.

JP 2009-164583 A

  However, since the high-power LED package described in Patent Document 1 has an insulating layer that is an anodized layer formed on the outer surface of the metal plate, the light reflectance is lower than that of the metal reflecting surface, and the light extraction efficiency is high. May decrease.

  Therefore, the present invention has been made in view of such circumstances, and an object of the present invention is to provide a light-emitting device that is excellent in light extraction efficiency and has little unevenness in emission chromaticity distribution or a method for manufacturing the same.

  In order to solve the above problems, a method for manufacturing a light emitting device according to the present invention includes a first step of preparing a lead frame having an element mounting portion and a recess formed around the element mounting portion, and the lead A second step of mounting the light emitting element on the element mounting portion of the frame; a first sealing portion containing a phosphor and in contact with the light emitting element; and a second sealing portion outside the first sealing portion. A third step of forming a sealing member, wherein in the third step, at least a part of the edge of the first sealing portion is a side surface of the concave portion on the element mounting portion side, or It is formed by dropping so as to be provided at the edge of the element mounting portion facing the side surface.

In addition, the manufacturing method of the light-emitting device of this invention can add the following structures.
The concave portion of the lead frame may be formed such that a side surface on the element mounting portion side has a convex curved surface that continues to the edge of the element mounting portion facing the side surface.
After forming the first sealing portion and before forming the second sealing portion, a light reflecting member may be formed by dropping in the recess of the lead frame.
The concave portion of the lead frame is formed such that a side surface on the side far from the element mounting portion has an inclined surface inclined toward the element mounting portion, and the light reflecting member is passed through the inclined surface to the concave portion. It may be allowed to flow.
The concave portion of the lead frame may be formed so as to have a wide portion having an opening width wider than other portions, and the light reflecting member may flow into the concave portion through the wide portion.

  In order to solve the above problems, a light emitting device according to the present invention is mounted on a lead frame having an element mounting portion, a recess formed around the element mounting portion, and the element mounting portion of the lead frame. And a sealing member having a first sealing portion that contains a phosphor and is in contact with the light emitting device, and a second sealing portion outside the first sealing portion, At least a part of the edge of the first sealing portion is provided on the side surface of the concave portion on the side of the element mounting portion or the edge of the element mounting portion facing the side surface.

The light emitting device of the present invention can be added with the following configuration.
A light reflecting member may be provided in the recess of the lead frame.
The light reflecting member may be provided in contact with a part of the first sealing portion.

  According to the light emitting device of the present invention, it is possible to efficiently extract light while reducing unevenness in the emission chromaticity distribution. Moreover, according to the manufacturing method of the light-emitting device of this invention, such a light-emitting device can be manufactured comparatively cheaply.

It is the schematic top view (a) of the light-emitting device which concerns on one embodiment of this invention, and the schematic sectional drawing (b) in the AA cross section. It is a schematic sectional drawing (a)-(h) which shows an example of the manufacturing method of the light-emitting device which concerns on one embodiment of this invention. It is a schematic sectional drawing (a)-(f) explaining the relationship between the solid surface and the surface shape of the droplet dripped on it. It is the schematic top view (a) of the light-emitting device which concerns on one embodiment of this invention, and the schematic sectional drawing (b) in the BB cross section. It is a schematic sectional drawing (a) and (b) which shows an example of 1 process in the manufacturing method of the light-emitting device which concerns on one embodiment of this invention.

  Hereinafter, embodiments of the invention will be described with reference to the drawings as appropriate. However, the light-emitting device and the manufacturing method thereof described below are for embodying the technical idea of the present invention, and the present invention is not limited to the following unless otherwise specified. In addition, the size, positional relationship, and the like of members illustrated in each drawing may be exaggerated for clarity of explanation.

<Embodiment 1>
FIG. 1A is a schematic top view of the light-emitting device according to Embodiment 1, and FIG. 1B is a schematic cross-sectional view showing the AA cross section in FIG. The light emitting device 100 of the example shown in FIG. 1 includes a lead frame 10, a light emitting element 20 mounted on the lead frame 10, and a sealing member 30 that contains a phosphor 40 and seals the light emitting element 20. ing. Hereinafter, “inside” and “outside” of the light emitting device can be considered, for example, with the light emitting element 20 as the center, the direction toward the light emitting element 20 is “inward”, and the direction away from the light emitting element 20 is “outward” It is.

  The lead frame 10 includes an element mounting part 11 and a recess 13 formed around the element mounting part. More specifically, the lead frame 10 includes a pair of a positive electrode and a negative electrode, and an element mounting portion 11 and a concave portion 13 are provided on one upper surface side thereof. In addition, the lead frame 10 forms a base body by integrally molding a molded body 60 so as to surround the element mounting portion 11.

  The light emitting element 20 is mounted on the element mounting portion 11 of the lead frame 10. More specifically, the light emitting element 20 is bonded to one pole of the lead frame 10 with an adhesive and is connected to both poles of the lead frame 10 with wires.

  The sealing member 30 includes a first sealing portion 301 containing the phosphor 40 and in contact with the light emitting element 20, and a second sealing portion 302 outside the first sealing portion 301. That is, the sealing member 30 contains the phosphor 40 in a biased manner in the first sealing portion 301. At least a part, preferably substantially all, of the edge (edge) 35 of the first sealing portion 301 is provided on the side surface 15 on the element mounting portion side of the recess of the lead frame. Thereby, the surface of the 1st sealing part 301 is the convex surface which protruded high upwards.

  In such a light emitting device 100, the wavelength conversion and scattering of light by the phosphor 40 is performed in the first sealing portion 301, that is, in the vicinity of the light emitting element 20 in the sealing member 30, Compared with the case where the phosphor is dispersed over substantially the entire area of the sealing member, the light source can be made smaller with respect to the surface of the sealing member, and the light extraction efficiency can be increased. Moreover, since the surface of the first sealing portion 301 can be formed as a convex surface that protrudes high, the difference in optical path length in each direction within the first sealing portion 301 can be reduced, and the phosphor 40 in the first sealing portion 301 can be reduced. Even if these are dispersed, it is possible to emit light with less unevenness of the chromaticity distribution. In addition, in the 1st sealing part 301, you may make the fluorescent substance 40 settle and disperse | distribute a diffusing agent.

  2A to 2H are schematic cross-sectional views illustrating an example of a method for manufacturing the light-emitting device according to Embodiment 1. FIG. The light emitting device 100 shown in FIG. 1 is manufactured through the following steps. The light emitting device manufacturing method of the present invention includes a first step of preparing a lead frame 10 having an element mounting portion 11 and a recess 13 formed around the element mounting portion, and an element of the lead frame 10. A second step of mounting the light emitting element 20 on the mounting portion 11, a first sealing portion 301 containing the phosphor 40 and in contact with the light emitting element 20, and a second sealing portion 302 outside the first sealing portion 301 The manufacturing method described here is merely an example as long as it includes at least the third step of forming the sealing member 30 having the above.

  First, as shown in FIG. 2A, a lead frame 10 having an element mounting portion 11 and a recess 13 formed around the element mounting portion 11 is prepared (first step). Here, the step of forming the recess 13 on the upper surface side of the lead frame 10 is shown, but it may be prepared by purchasing the lead frame 10 in which the recess 13 is formed in advance. In addition, the recessed part 13 can be formed by etching, die shaping | molding, etc. other than the press work shown in figure.

  Next, as shown in FIG. 2B, a molded body 60 is integrally formed with the lead frame 10 to form a base. Specifically, a plate-like member in which a plurality of lead frames 10 are connected is sandwiched between an upper die and a lower die that have been processed into a predetermined shape, and a fluid state (liquid, sol The constituent material of the molded body 60 in the form of a slurry or a slurry is injected and solidified. Thereafter, when the molded body 60 is released from the mold, a plurality of substrates in a continuous state are obtained.

  Next, as shown in FIG. 2C, the light emitting element 20 is mounted on the element mounting portion 11 of the lead frame 10 (second step). Specifically, the light emitting element 20 is bonded to the element mounting portion 11 of one pole of the lead frame 10 with an adhesive, and is connected to both poles of the lead frame 10 with wires.

  Next, as shown in FIGS. 2D, 2E, and 2F, a sealing member 30 is formed on the lead frame 10 (third step). First, the first sealing portion 301 is formed by dropping (potting). The dropping method is an inexpensive molding method that does not use a molding machine or a mold as compared with the compression molding method, transfer molding method, injection molding method, or cast molding method. Specifically, the constituent material of the first sealing portion 301 in a fluid state (liquid, sol, or slurry) is placed on the lead frame 10 so as to cover the light emitting element 20 using a dispenser or the like. And is solidified by heating or cooling as it is (see FIG. 2D). At this time, the first sealing portion 301 has at least a part, preferably substantially all, of the edge 35 on the side surface 15 on the element mounting portion side of the recess of the lead frame or the edge 16 of the element mounting portion facing the side surface. Formed as provided. Further, the first sealing portion 301 may be solidified with the lead frame 10 turned upside down, that is, with the upper surface of the lead frame 10 facing downward in the vertical direction. Thereby, the surface of the 1st sealing part 301 can be made to protrude highly using gravity.

  Next, after dropping the constituent material of the first sealing portion 301 onto the lead frame 10, the constituent material of the second sealing portion 302 in a fluid state is used by using a dispenser or the like. It is dropped on the lead frame 10 so as to cover 301, and is solidified by heating or cooling as it is (see FIG. 2 (e)). In this example, as shown in FIG. 2F, the first sealing portion 301 and the second sealing portion 302 are simultaneously solidified. Thus, the 2nd sealing part 302 improves the adhesiveness of the 1st sealing part 301 and the 2nd sealing part 302 by forming in the state where the 1st sealing part 301 is not solidified or semi-solidified. be able to. In addition, the first sealing portion 301 and the second sealing portion 302 may be solidified separately. That is, the second sealing portion 302 may be formed after the first sealing portion 301 is completely solidified.

  Note that the second sealing portion 302 can be formed by a compression molding method, a transfer molding method, an injection molding method, a cast molding method, or the like, in addition to the dropping method. The second sealing portion 302 can also be formed by adhering a preformed one to the lead frame 10 or the base with an adhesive or the like.

  Finally, as shown in FIG. 2G, the plate member is cut to separate the light emitting device. Before forming the sealing member 30, the plate member may be cut to separate the lead frame 10. As described above, the light emitting device 100 shown in FIG.

  FIGS. 3A to 3F are schematic cross-sectional views illustrating the relationship between the solid surface and the surface shape of the liquid droplet dropped on the solid surface. First, as shown in FIG. 3A, the droplet L dropped on the flat surface of the solid S has a convex curved surface that forms a contact angle θ [degree] with the surface of the solid S due to its surface tension. Have it. The contact angle θ is defined as an angle formed by the tangent to the surface of the droplet L and the surface of the solid S (an angle including the droplet L) at the contact point between the surface (edge) of the droplet L and the solid S. . This contact angle θ is determined by the surface tension of the material constituting each of the droplet L and the solid S. For the same solid S and droplet L, the contact angle θ takes a specific value. Therefore, in order to increase the height h of the droplet L, it is considered that the surface of the solid S is inclined by an angle α [degree] from the horizontal plane as shown in FIG. At this time, the contact angle of the droplet L with respect to the surface of the inclined solid S is maintained substantially θ, but the pseudo contact angle with respect to the horizontal plane is approximately θ + α. Therefore, as shown in FIG. 3C, by providing at least a part, preferably substantially all, of the edge of the droplet L on the outward surface facing outward in the top view of the solid S, the height of the droplet L h can be increased. Further, since the droplet L exists at an almost original contact angle θ with respect to the outward surface of the solid S and is in a relatively stable state, its height can be obtained with good reproducibility. As shown in FIG. 3D, when the surface of the solid S is a convex curved surface, a plane (“tangential plane”) that contacts the surface of the solid S at the contact point between the solid S and the edge of the droplet L. Call). In the illustrated example, the tangential plane is inclined by an angle β [degree] with respect to the horizontal plane, and the pseudo contact angle of the droplet L with respect to the horizontal plane is substantially θ + β.

  Further, as shown in FIG. 3E, when the droplet L is approaching the angular edge of the solid S, the contact angle between the liquid L and the horizontal upper surface of the solid S is the original contact angle θ. And the downward angle of the outward surface that continues to the edge (inclination angle from the upper surface) γ [degree], and may exhibit a phenomenon called "wetting pinning effect" that cannot get over the edge until it reaches the sum of is there. At this time, the contact angle of the droplet L can take any value from θ to θ + γ. Therefore, the height h of the droplet L can be increased by utilizing this “wetting pinning effect”. As shown in FIG. 3 (f), when the edge of the solid S is rounded and has a convex curved surface R, the surface of the solid S is gradually changed from the upper surface to the outward surface. The “pinning effect” can be suppressed and the droplet L can be smoothly moved onto the outward surface.

  As described above, at least a part, preferably substantially all, of the edge of the droplet L is provided on the outwardly facing surface of the solid S as viewed from above, or on the edge facing the outwardly facing surface. It becomes easy to project the surface of the droplet L upward in the vertical direction starting from the surface or edge. As a result, the surface of the droplet L can be easily formed on a highly protruding convex surface, preferably a convex curved surface, and thus a substantially spherical surface. Moreover, the surface shape can be obtained with good reproducibility.

  As described above, at least a part, preferably substantially all, of the edge 35 of the first sealing portion is formed on the side surface 15 on the element mounting portion side of the recess of the lead frame 10 or the edge of the element mounting portion facing the side surface. By being provided in 16, it becomes easy to make the surface of the 1st sealing part 301 protrude upwards in the perpendicular direction from the side surface 15 or the edge 16 as a starting point. As a result, the surface of the first sealing portion 301 can be easily formed into a highly protruding convex surface, preferably a convex curved surface, and thus a substantially spherical surface. Moreover, the surface shape can be obtained with good reproducibility. Therefore, a light-emitting device that has excellent light extraction efficiency and can emit light with less chromaticity distribution can be manufactured at low cost.

  In addition, after forming a film having a small surface tension over the entire upper surface of the lead frame 10, the first sealing portion 301 is formed by dropping, thereby forming the surface of the first sealing portion 301 into a highly protruding convex surface. It is also possible. However, in that case, there is a possibility that the adhesion between the lead frame 10 and the first sealing portion 301 may be significantly reduced due to the coating interposed between the lead frame 10 and the first sealing portion 301. On the other hand, in the present invention, basically, the first sealing portion 301 is in direct contact with the surface of the lead frame 10, and high adhesion between the lead frame 10 and the first sealing portion 301 is obtained. A highly reliable light-emitting device can be provided. In particular, the edge 35 of the first sealing portion is provided on the side surface 15 on the element mounting portion side of the recess of the lead frame, so that the edge of the first sealing portion 301 is engaged with the lead frame 10. In addition, the adhesion between the lead frame 10 and the first sealing portion 301 can be further enhanced.

  Hereinafter, preferred forms of the lead frame 10 and the sealing member 30 will be described in detail.

  In the light emitting device 100 of the example shown in FIG. 1, the lead frame 10 includes an element mounting portion 11 and a recess 13 on the upper surface side. The element mounting portion 11 is a portion where the light emitting element 20 of the lead frame 10 is mounted, and can be specified as, for example, a region inside the top view from the concave portion 13 of the lead frame 10. In particular, in this example, it may be said that the element mounting portion 11 is a convex portion formed by the concave portion 13. By forming the recess 13 on the upper surface side of the lead frame 10, the side surface 15 on the element mounting portion side and the edge 16 of the element mounting portion facing the side surface can be provided inside the outermost end surface of the lead frame 10. it can. Then, at least a part of the edge 35 of the first sealing portion can be provided on the side surface 15 on the element mounting portion side of the recess or the edge 16 of the element mounting portion facing the side surface. As a result, the outflow of the first sealing portion 301 to the outside of the lead frame 10 is suppressed, and the surface of the first sealing portion 301 is stably raised to a convex surface inside the outermost end surface of the lead frame 10. It can be easily formed. Further, it is possible to prevent the exposed portion of the lead frame 10 serving as the terminal portion for external connection from being contaminated by the bleeding component of the first sealing portion 301. In particular, when the molded body 60 is integrally formed with the lead frame 10 using a mold, the lead frame 10 preferably includes a concave portion 13 that is formed inwardly spaced from the outermost end surface. This prevents the molded body 60 from covering the side surface 15 on the element mounting portion side of the recess of the lead frame 10 to be provided and the edge 16 of the element mounting portion facing the side surface. It can function effectively.

  In the light emitting device 100 of the example illustrated in FIG. 1, the concave portion 13 is provided in a perfect circle shape surrounding the light emitting element 20 in a top view of the lead frame 10. The recess 13 provides a side surface 15 on the element mounting portion side of the recess for positioning at least a part of the edge 35 of the first sealing member, and a lip 16 of the element mounting portion facing the side surface, and has fluidity. It functions as a barrier for blocking the first sealing portion 301. For this reason, the recess 13 is preferably provided so as to surround the light emitting element 20. Thereby, it is easy to dam the first sealing portion 301, and the ratio that the edge 35 of the first sealing portion is provided on the side surface 15 on the element mounting portion side of the recess or the edge 16 of the element mounting portion facing the side surface increases. It is easy to make the surface of the first sealing portion 301 protrude high. Further, the symmetry of the surface shape of the first sealing portion 301 can be enhanced. It is preferable that the recess 13 is provided in a curved shape, for example, at least at its corners, such as a rectangular shape with rounded corners, as viewed from the top of the lead frame 10. Thereby, distortion generated on the surface of the first sealing portion 301 in the vicinity of the corner portion of the concave portion 13 is alleviated, the surface of the first sealing portion 301 is easily formed into a relatively smooth convex surface, and the light extraction efficiency is increased. Cheap. In particular, the recess 13 is preferably provided in an annular shape when viewed from the top of the lead frame 10, in particular, in an elliptical shape, and more preferably in a perfect circular shape. Thereby, the surface of the 1st sealing part 301 can be formed in a convex surface with few distortions, it is easy to improve the extraction efficiency of light, and the light distribution excellent in symmetry can be obtained. The recess 13 is preferably provided so that the light emitting element 20 is substantially at the center, so that the symmetry of light distribution is enhanced.

  In addition, the recessed part 13 is not restricted to frame shape, You may provide in strip | belt shape, such as linear form. Thereby, the concave portion 13 can be easily formed in a small size, and the side surface 15 on the element mounting portion side is easily provided in a small region on the upper surface side of the lead frame 10. In that case, it is preferable that at least two recesses 13 are provided so as to sandwich the light emitting element 20 because the symmetry of the surface shape of the first sealing portion 301 is easily improved. Moreover, the recessed part 13 may be provided in multiple numbers spaced apart like the broken line shape, and may be further scattered. Furthermore, even when the concave portion 13 is provided in a belt shape, it is preferable that the corner portion or the whole of the concave portion 13 is curved in a top view of the lead frame 10. Thereby, the distortion produced on the surface of the 1st sealing part 301 is eased, and the surface of the 1st sealing part 301 is easy to form in a comparatively smooth convex surface.

  In the light emitting device 100 of the example shown in FIG. 1, the concave portion 13 of the lead frame is formed such that the side surface 15 on the element mounting portion side has a convex curved surface that continues to the edge 16 of the element mounting portion facing the side surface. ing. Here, let us consider a case where the first sealing portion 301 in a fluid state is dropped on the lead frame 10 and reaches the edge 16 facing the side surface of the recess of the lead frame 10 on the element mounting portion side. When the side surface on the element mounting portion side of the recess of the lead frame is a flat surface bent from the surface continuous to the upper side, the first sealing portion has the element mounting portion of the recess due to the “wetting pinning effect” described above. It accumulates once on the surface continuous to the upper side of the side surface. When the first sealing portion gets over the edge facing the side surface of the concave portion on the element mounting portion side, the first sealing portion may flow out vigorously due to its own enlarged weight, and the surface shape may be destroyed. However, when the side surface 15 on the element mounting portion side of the concave portion of the lead frame 10 has a convex curved surface continuous to the edge 16 of the element mounting portion facing the side surface, as described above, the “wetting pinning effect” is suppressed. And the 1st sealing part 301 can be smoothly moved on the side surface 15 by the side of the element mounting part of a recessed part. Thereby, it can make it easy to shape | mold stably on the convex surface which protruded the surface of the 1st sealing part 301 highly. At this time, at least a part of the edge 35 of the first sealing portion may be on the convex curved surface, or may be on the side surface that continues beyond the convex curved surface. In addition, when the recessed part 13 is formed by metal mold | die shaping | molding, the biting to the metal mold | die of the lead frame 10 is suppressed by making the uppermost part of the side surface 15 by the side of the element mounting part of a recessed part into a convex curved surface, Can increase the sex.

  As described above, the larger the inclination angle (α) of the side surface 15 on the element mounting portion side of the recess from the substantially horizontal upper surface of the lead frame 10, the easier the surface of the first sealing portion 301 protrudes. However, from the viewpoint of processing the lead frame 10, the inclination angle (α) of the side surface 15 on the element mounting portion side of the recess is preferably 90 degrees or less. Therefore, the inclination angle (α) of the side surface 15 on the element mounting portion side of the recess from the substantially horizontal upper surface of the lead frame 10 is preferably 45 to 90 degrees, and more preferably 70 to 90 degrees.

  The light emitting device 100 of the example shown in FIG. 1 includes a molded body 60 integrally formed with the lead frame 10 so as to surround the light emitting element 20, and the element mounting portion 11 and the recess 13 are formed inside the molded body 60. Yes. The first sealing portion 301 is provided inside the molded body 60. Thereby, the outflow of the first sealing portion 301 to the outside of the lead frame 10 can be suppressed, and the first sealing portion 301 can be easily formed stably. Further, the molded body 60 functions as a barrier that protects the first sealing portion 301 from damage due to external force and contamination by dust. Further, the inner wall surface of the molded body 60 functions as a reflecting mirror that effectively reflects the light emitted from the light emitting element 20 to the front of the apparatus (above the lead frame 10), thereby increasing the front luminous intensity of the light emitting apparatus. Can do. In particular, when the entire surface of the first sealing portion 301 is provided on the inner side of the upper surface of the opening of the molded body 60, these effects can be obtained remarkably.

<Embodiment 2>
FIG. 4A is a schematic top view of the light-emitting device according to Embodiment 2, and FIG. 4B is a schematic cross-sectional view showing a BB cross section in FIG. The light emitting device 200 of the example shown in FIG. 4 includes a lead frame 10, a light emitting element 20 mounted on the lead frame 10, a sealing member 30 that contains a phosphor 40 and seals the light emitting element 20, and light reflection. The member 50 is provided.

  The lead frame 10 is composed of a pair of a positive electrode and a negative electrode, and an element mounting portion 11 and a recess 13 are provided on one upper surface side thereof. In this example, the side surface 15 on the element mounting portion side of the recess of the lead frame is a flat surface, and the edge 16 of the element mounting portion facing the side surface is angular. In addition, the lead frame 10 is formed by integrally molding a molded body 60 so as to surround the light emitting element 20 and constitutes a base. The light emitting element 20 is bonded to the element mounting portion 11 of one pole of the lead frame 10 with an adhesive, and is connected to both poles of the lead frame 10 with wires.

  The sealing member 30 includes a first sealing portion 301 in contact with the light emitting element 20 and a second sealing portion 302 outside the first sealing portion 301. That is, the sealing member 30 contains the phosphor 40 in a biased manner in the first sealing portion 301. At least a part, preferably substantially all, of the edge 35 of the first sealing portion 301 is provided on the edge 16 of the element mounting portion facing the side surface of the recess of the lead frame on the element mounting portion side. Thereby, the surface of the 1st sealing part 301 is the convex surface which protruded high upwards.

  Like the first embodiment, such a light emitting device 200 is also excellent in light extraction efficiency and can emit light with less unevenness in chromaticity distribution.

  Further, in the light emitting device 200 shown in FIG. 4, a light reflecting member 50 is provided in the recess 13 of the lead frame. Thereby, the light emitted downward from the phosphor 40 in the light emitting element 20 or the first sealing portion 301 is suppressed from being confined in the recess 13, and the light can be effectively extracted upward. . For this reason, the light reflecting member 50 preferably has a higher light reflectivity than the upper surface of the lead frame 10.

  Thus, in the above-described third step, after the first sealing portion 301 is formed and before the second sealing portion 302 is formed, the light reflecting member 50 is dropped into the recess 13 of the lead frame. It may be formed. Specifically, the constituent material of the light reflecting member 50 in a fluid state is dropped onto the lead frame 10 using a dispenser or the like, is introduced into the predetermined portion, and is solidified by heating or cooling.

  FIGS. 5A and 5B are schematic cross-sectional views illustrating an example of one step in the method for manufacturing the light emitting device according to Embodiment 2. FIGS. The concave portion 13 that can be formed in the lead frame 10 is relatively small, and since the first sealing portion 301 and a wire are present, the light reflecting member 50 may not be easily dropped directly into the concave portion 13.

  Therefore, in the light emitting device 200 of the example shown in FIG. 4, the concave portion 13 of the lead frame is formed so as to have a wide portion 131 whose opening width is wider than other portions. As a result, as shown in FIG. 5A, the tip of a dispenser or the like can be placed on the wide portion 131, and the light reflecting member 50 can be dropped directly on the wide portion 131. In this way, the light reflecting member 50 can be caused to flow into the recess 13 through the wide portion 131. The top view shape of the wide portion 131 is not particularly limited, and may be a rectangular shape, a circular shape, a triangular shape, or the like. In addition, it is preferable that the lead frame is formed on the side opposite to the side where the other pole is located from the viewpoint of ease of formation and miniaturization of the lead frame.

  As another means, it is considered that the light reflecting member 50 flows into the recess 13 from the upper surface outside the recess 13 of the lead frame 10. When the light reflecting member 50 in a fluid state reaches the edge 18 facing the side surface 17 on the side far from the element mounting portion of the recess, the light reflection is performed when the side surface 17 is a flat surface and the edge 18 is angular. Due to the “wetting pinning effect” described above, the member 50 tends to accumulate on the upper surface continuous with the upper side of the side surface 17 and hardly flows into the recess 13.

  Therefore, as shown in FIG. 5B, the concave portion 13 of the lead frame is formed so that the side surface 17 on the side far from the element mounting portion of the concave portion has an inclined surface inclined toward the element mounting portion 11. May be. Then, the light reflecting member 50 is caused to flow into the recess 13 through this inclined surface. In this way, the “wetting pinning effect” at the edge 18 facing the side surface of the recess that is far from the element mounting portion can be suppressed, and the light reflecting member 50 can easily flow into the recess 13. The inclination angle of the inclined surface from the substantially horizontal upper surface of the lead frame is greater than 0 degree and less than 90 degrees, preferably 20 to 70 degrees, and more preferably 30 to 60 degrees. The side surface 17 on the side far from the element mounting portion of the concave portion may be configured by a plurality of such inclined surfaces. Further, the inner surface of the recess 13 may have a substantially horizontal bottom surface, or may be constituted by a side surface 15 on the element mounting portion side and a side surface 17 on the side far from the element mounting portion as shown in the figure. Further, the recess 13 may be formed such that the side surface 17 on the side farther from the element mounting portion of the recess has a convex curved surface that continues to the edge 18 facing the side surface. Thereby, as described above, the “wetting pinning effect” can be suppressed and the light reflecting member 50 can be smoothly moved into the recess 13. Such a configuration can also be applied to the side surface of the wide portion 131.

  Further, when the light reflecting member 50 is caused to flow into the recessed portion 13 from the upper surface outside the recessed portion 13 of the lead frame 10 in this way, the light reflecting member 50 is formed in the recessed portion 13 of the lead frame 10 and on the upper surface outside the recessed portion 13. It is provided continuously at least in part. Thereby, light emitted from the light emitting element 20 and the phosphor 40 in the first sealing portion 301 can be suppressed from being absorbed on the upper surface of the lead frame 10. Further, deterioration due to corrosive gas on the upper surface of the lead frame 10 can be suppressed. The light reflecting member 50 may be provided so as to cover a part of the upper surface of the lead frame 10, or may be provided so as to cover substantially the entire upper surface inside the molded body 60.

  In the light emitting device 200 shown in FIG. 4, the light reflecting member 50 is provided in contact with a part of the first sealing portion 301. More specifically, the light reflecting member 50 is provided so as to cover the edge 35 of the first sealing portion and climb up to a part of the surface of the first sealing portion 301. Thereby, it is suppressed that light is confined between the first sealing portion 301 and the light reflecting member 50, and from the light emitting element 20 and the phosphor 40 at the contact portion between the first sealing portion 301 and the light reflecting member 50. The emitted light can be effectively extracted by reflecting upward.

  In the first embodiment described above, the surface (exposed surface) of the sealing member 30, that is, the surface of the second sealing portion 302 in the illustrated example is a substantially flat surface. On the other hand, in the light emitting device 200 of the example illustrated in FIG. 4, the surface of the second sealing portion 302 is a convex surface. The edge of the 2nd sealing part 302 is provided in the outward surface of the recessed part (it can also be seen as a convex part) formed in the molded object 60. FIG. As described above, when the second sealing portion 302 is also formed by dropping, at least a part, preferably substantially all of the edge of the second sealing portion 302 is a recess of the molded body 60, as in the first sealing portion 301 described above. It may be formed so as to be provided on the outwardly facing surface facing the outer side of the upper surface or the edge facing the outwardly facing surface. Thereby, the surface of the 2nd sealing part 302 can be formed in the convex surface which protruded highly, and the extraction efficiency of light can be improved. In addition, the preferable form of the recessed part 13 of the lead frame 10 with respect to the above-mentioned 1st sealing part 301 is applicable to the preferable form of the recessed part of the molded object 60 with respect to the 2nd sealing part 302. FIG.

  The first sealing portion 301 and the second sealing portion 302 may be made of the same material and have the same refractive index, but the refractive index of each sealing portion is gradually changed to the refractive index of air. By bringing them closer, light can be efficiently extracted from the light emitting element 20 into the sealing member 30, and reflection of light at the interface between the two sealing portions can be suppressed to increase the light extraction efficiency. Therefore, the refractive index of the first sealing part 301 may be higher than the refractive index of the second sealing part 302.

  As described above, in the first and second embodiments, the light emitting device including the base body in which the molded body 60 is integrally formed with the lead frame 10 has been described. However, the present invention is not limited to the light emitting device including the lamp 60 The present invention can also be applied to a type of LED. In addition, as described above, the example in which the concave portion is mainly used as the structure in which the lead frame is provided with the outward face has been described.

  Hereinafter, each component of the light emitting device of the present invention will be described.

(Lead frame 10)
For the lead frame, a metal member that can conduct electricity to the light emitting element can be used. Specifically, copper, aluminum, gold, silver, tungsten, iron, nickel, cobalt, molybdenum, or alloys thereof, phosphor bronze, iron-containing copper, and the like can be given. Further, a plating or light reflecting film such as silver, aluminum, rhodium, platinum, gold, copper, palladium, nickel or an alloy thereof may be provided on the surface layer. Among these, silver or a silver alloy is preferable from the viewpoint of light reflectivity. However, since silver is easily discolored by a corrosive gas such as a sulfur-containing gas, in order to avoid it, it is also possible to select one other than silver and silver alloys.

(Light emitting element 20)
As the light emitting element, a semiconductor light emitting element such as an LED element or an LD element can be used. The light emitting element may be any element in which a pair of positive and negative electrodes is provided in an element structure composed of various semiconductors. In particular, a light-emitting element of a nitride semiconductor (In _x Al _y Ga _1-xy N, 0 ≦ x, 0 ≦ y, x + y ≦ 1) that can excite the phosphor efficiently is preferable. In addition, a gallium arsenide-based or gallium phosphorus-based semiconductor light emitting element emitting green to red light may be used. In the case of a light emitting device in which a pair of positive and negative electrodes are provided on the same surface side, the mounting form may be face-up mounting in which each electrode is connected to a lead frame with a wire, or each electrode is lead with a conductive adhesive. Face-down (flip chip) mounting connected to the frame may also be used. In addition, a light emitting element having a counter electrode structure in which a pair of positive and negative electrodes are provided on opposite surfaces may be used. The light emitting element may be mounted via a submount. By providing a metal layer such as silver or aluminum or a dielectric reflection film on the mounting surface side of the light emitting element, light extraction efficiency can be increased. The number of light-emitting elements mounted on one light-emitting device may be one or more, and the size, shape, and emission wavelength may be arbitrarily selected. For example, red, green, and blue light emitting elements may be mounted on one light emitting device. The plurality of light emitting elements may be irregularly arranged, but a preferable light distribution can be easily obtained by arranging regularly or periodically such as a matrix or a concentric circle. In addition, the plurality of light emitting elements can be connected in series or in parallel.

(Sealing member 30)
The sealing member is a member that seals a part of the light emitting element, the wire, and the lead frame to protect them from dust, moisture, external force, and the like. The base material of the sealing member may be any material that has electrical insulation, can transmit light emitted from the light-emitting element (preferably has a transmittance of 70% or more), and has fluidity before solidification. . Specific examples include silicone resins, silicone-modified resins, silicone-modified resins, epoxy resins, phenol resins, polycarbonate resins, acrylic resins, TPX resins, polynorbornene resins, or hybrid resins containing one or more of these resins. Glass may be used. Of these, silicone resins are preferred because they are excellent in heat resistance and light resistance and have little volume shrinkage after solidification. In particular, the base material of the sealing member is preferably composed mainly of a phenyl silicone resin, which has excellent gas barrier properties and can easily suppress deterioration of the lead frame due to corrosive gas. In addition, when the surface of the sealing member is a substantially flat surface, dimethyl silicone resin is used for the second sealing portion, and when the surface is a convex surface, phenyl silicone resin is used for the second sealing portion. Can be increased.

  The sealing member may include particles having various functions such as a filler and a phosphor in the base material. As the filler, a diffusing agent, a coloring agent, or the like can be used. Specifically, silica, titanium oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, zinc oxide, barium titanate, aluminum oxide, basic zinc carbonate, iron oxide, chromium oxide , Manganese oxide, glass, carbon black and the like. The shape of the filler particles may be crushed or spherical. Further, it may be hollow or porous.

(Phosphor 40)
The phosphor absorbs at least part of the primary light emitted from the light emitting element, and emits secondary light having a wavelength different from that of the primary light. Specifically, yttrium-aluminum-garnet (YAG) activated with cerium, nitrogen-containing calcium aluminosilicate activated with europium and / or chromium (CaO—Al ₂ O ₃ —SiO ₂ ), activated with europium Examples thereof include silicate ((Sr, Ba) ₂ SiO ₄ ). Thus, a light emitting device that emits mixed light (for example, white light) of primary light and secondary light having a visible wavelength, or a light emitting device that emits visible light secondary light when excited by the primary light of ultraviolet light is used. Can do. A plurality of types of phosphors may be used in combination.

(Light reflecting member 50)
The light reflecting member is a member that reflects light emitted from the light emitting element or the phosphor. The light reflecting member may have any electrical insulating property, excellent light reflecting property, and fluidity before solidification. Specifically, the light reflecting member may be a resin base material in which light reflecting particles are added. Examples of the base material include silicone resins, silicone-modified resins, silicone-modified resins, epoxy resins, phenol resins, polycarbonate resins, acrylic resins, TPX resins, polynorbornene resins, or hybrid resins containing one or more of these resins. Of these, silicone resins are preferred because they are excellent in heat resistance and light resistance and have little volume shrinkage after solidification. Examples of the light-reflective particles include silica, titanium oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, zinc oxide, barium titanate, aluminum oxide, and basic zinc carbonate. . Among these, titanium oxide is preferable because it has a high refractive index and a high reflectance can be obtained when added to a base material. Further, zinc compounds such as basic zinc carbonate are mainly white and have a relatively high reflectance, and are effective in suppressing deterioration of the lead frame due to sulfur-containing gas.

(Molded body 60)
The base material of the molded body is aliphatic polyamide resin, semi-aromatic polyamide resin, polyethylene terephthalate, polycyclohexane terephthalate, liquid crystal polymer, polycarbonate resin, syndiotactic polystyrene, polyphenylene ether, polyphenylene sulfide, polyether sulfone resin, polyether ketone. Thermosetting resins such as thermoplastic resins such as resins and polyarylate resins, polybismaleimide triazine resins, epoxy resins, silicone resins, silicone modified resins, silicone modified resins, polyimide resins, and polyurethane resins. In these base materials, as a filler or a coloring pigment, glass, silica, titanium oxide, magnesium oxide, magnesium carbonate, magnesium hydroxide, calcium carbonate, calcium hydroxide, calcium silicate, magnesium silicate, wollastonite, Mica, zinc oxide, barium titanate, potassium titanate, aluminum borate, aluminum oxide, zinc oxide, silicon carbide, antimony oxide, zinc stannate, zinc borate, iron oxide, chromium oxide, manganese oxide, carbon black, etc. Particles or fibers can be added. In addition, the molded body can be formed of glass, ceramics, or the like.

(Wire)
The wire is a member that electrically connects the electrode of the light emitting element and the lead frame. As the wire, a metal wire of gold, copper, silver, platinum, aluminum, or an alloy thereof can be used. In particular, a gold wire that is unlikely to break due to stress from the sealing member and is excellent in thermal resistance or the like is preferable.

(adhesive)
The adhesive is a member that fixes the light emitting element to the lead frame. As the insulating adhesive, an epoxy resin, a silicone resin, a polyimide resin, or a modified resin or a hybrid resin thereof can be used. As the conductive adhesive, a conductive paste such as silver, gold, or palladium, a solder such as gold-tin, or a brazing material such as a low melting point metal can be used.

  Examples according to the present invention will be described in detail below. Needless to say, the present invention is not limited to the following examples.

<Example 1>
The light emitting device of Example 1 is a surface light emitting (top view) type surface mount type LED having a structure of the example shown in FIG. 1 and having a length of 5.0 mm, a width of 6.5 mm, and a thickness of 1.35 mm. The pair of positive and negative lead frames 10 are obtained by applying a silver plating to the surface of a copper alloy base material having a thickness of 0.5 mm. In addition, the lead frame 10 is formed by integrally molding a molded body 60 made of an epoxy resin containing a white pigment of titanium oxide and a silica filler by a transfer molding method to constitute a base. A substantially circular cavity having a diameter of 4.3 mm and a depth of 0.85 mm is formed in the center of the base body by the molded body 60. This cavity is a two-stage type, and has an upper step portion having a perfect circle shape with a width of 0.33 mm at a position of a depth of 0.2 mm. In addition, a concave portion having a circular shape in a top view with a width of 0.17 mm and a depth of 0.1 mm is formed in the upper stage portion. Note that a part of the upper surface of the lead frame 10 constitutes a part of the bottom surface of the cavity and extends to the outside of the molded body 60. In this cavity, one light emitting element 20 is bonded to the negative lead frame 10 with an adhesive which is a translucent epoxy resin, and each electrode is connected to the positive and negative lead frames 10 with gold wires. It is connected. The light-emitting element 20 includes a nitride semiconductor n-type layer, an active layer, and a p-type layer sequentially stacked on a sapphire substrate, which can emit blue light (center wavelength of about 460 nm), is 450 μm in length, 450 μm in width, and has a thickness. It is a 120 μm LED chip. The lead frame 10 on the negative electrode side is formed with a concave portion 13 having an inner diameter of 0.8 mm, an opening width of 0.1 mm, and a depth of 0.1 mm as viewed from above by press working. The light emitting element 20 is arranged at substantially the center of the element mounting portion 11 to be formed.

  The sealing member 30 is provided in the cavity of the base body by a dropping method, and seals the light emitting element 20. The sealing member 30 includes two parts, a first sealing portion 301 that contacts the light emitting element 20 and covers the upper side and the side, and a second sealing portion 302 that contacts the first sealing portion 301. It consists of parts. Most of the edge 35 of the first sealing portion is provided on the edge 16 facing the side surface of the recess 13 of the lead frame 10 on the element mounting portion side. The surface of the first sealing portion 301 is a substantially convex curved surface with a maximum height of 0.3 mm from the upper surface of the lead frame 10. The first sealing portion 301 is made by using a dimethyl silicone resin having a refractive index of 1.41 as a base material, and YAG phosphor 40 activated by cerium is dispersed therein. The second sealing portion 302 is the same dimethyl silicone resin as the first sealing portion 301. The surface of the second sealing portion 302 is a substantially flat surface formed so as to be substantially flush with the upper surface of the base body, that is, the molded body 60.

  When the light emitting device of Example 1 is driven at a forward current of 60 mA, it can emit light with a luminous flux value of 23.2 lumen (chromaticity x value = 0.35 conversion). Further, when compared with a light emitting device having the same configuration except that the sealing member is composed of one layer in which the same phosphor 40 as that of the first sealing portion 301 is dispersed over the entire region, the emission chromaticity distribution is uneven. In particular, the phenomenon (referred to as “yellow ring”) in which the light component at a high angle (emitted to the side of the apparatus) appears yellowish has been improved.

  The light emitting device according to the present invention includes a backlight source of a liquid crystal display, various lighting devices, a large display, various display devices such as advertisements and destination guidance, and an image reading device in a digital video camera, a facsimile, a copier, a scanner, and the like. It can be used for projector devices.

DESCRIPTION OF SYMBOLS 10 ... Lead frame (11 ... Element mounting part, 13 ... Recessed part (131 ... Wide part), 15 ... Side surface of the recessed part on the element mounting part side, 16 ... Edge facing the side surface of the recessed part on the element mounting part side, 17 ... Recessed part Side face far from the element mounting part, 18 ... edge facing the side face of the concave part far from the element mounting part)
DESCRIPTION OF SYMBOLS 20 ... Light emitting element 30 ... Sealing member (301 ... 1st sealing part, 302 ... 2nd sealing part, 35 ... Edge of 1st sealing part)
DESCRIPTION OF SYMBOLS 40 ... Phosphor 50 ... Light reflection member 60 ... Molded object 100, 200 ... Light-emitting device

Claims (8)

A first step of preparing a lead frame having an element mounting portion and a recess formed around the element mounting portion;
A second step of mounting a light emitting element on the element mounting portion of the lead frame;
A third step of forming a sealing member having a first sealing portion that contains a phosphor and is in contact with the light emitting element, and a second sealing portion outside the first sealing portion;
In the third step, the first sealing portion is provided such that at least a part of an edge thereof is provided on a side surface of the concave portion on the side of the device mounting portion, or on an edge of the device mounting portion facing the side surface. Formed by dripping ,
A method for manufacturing a light emitting device, wherein after forming the first sealing portion and before forming the second sealing portion, a light reflecting member is formed in the recess of the lead frame by dropping .   2. The method of manufacturing a light emitting device according to claim 1, wherein the concave portion of the lead frame is formed such that a side surface on the element mounting portion side has a convex curved surface continuous to a lip of the element mounting portion facing the side surface. The concave portion of the lead frame is formed such that a side surface far from the element mounting portion has an inclined surface inclined toward the element mounting portion,
It said light reflecting member, a manufacturing method of a light-emitting device according to claim 1 or 2 is introduced into the recess through the inclined surface. The concave portion of the lead frame is formed so as to have a wide portion whose opening width is wider than other portions,
Method of manufacturing a light emitting device according to the light reflecting member, in any one of claims 1 to 3 is introduced into the recess through the wide portion. 5. The method of manufacturing a light emitting device according to claim 1, wherein the light reflecting member is continuously provided in at least a part of the upper surface outside the concave portion and outside the concave portion of the lead frame. A molded body is integrally formed on the lead frame so as to surround the element mounting portion and the recess,
The method for manufacturing a light emitting device according to claim 5, wherein the light reflecting member is provided so as to cover substantially the entire upper surface outside the concave portion inside the molded body of the lead frame. The light-emitting device manufacturing method according to claim 1, wherein the light-reflecting member is formed by adding light-reflective particles to a resin base material. A lead frame having an element mounting portion and a recess formed around the element mounting portion;
A light emitting element mounted on an element mounting portion of the lead frame;
A first sealing part that contains a phosphor and is in contact with the light emitting element; and a second sealing part that is outside the first sealing part, and a sealing member,
At least a part of the edge of the first sealing portion is provided on a side surface of the concave portion on the element mounting portion side, or on an edge of the element mounting portion facing the side surface ,
A light-reflecting member in which light-reflecting particles are added to a resin base material is provided in the concave portion of the lead frame so as to crawl up to a part of the surface of the first sealing portion. apparatus.

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