JPH0563068U - Resin-sealed light emitter - Google Patents

Abstract

(57) [Abstract] [Purpose] Achieves narrow directivity and high front strength without reducing the front strength when the lens diameter is reduced. [Structure] Recessed portion 1a on which light emitting semiconductor element 2 is mounted
The inside is sealed with a resin 5 having a smaller refractive index than the sealing resin 4. The interface between the sealing resin 4 and the resin 5 is a concave surface. Light emitted from the light emitting semiconductor element 2 is condensed at the interface between the sealing resin 4 and the resin 5 and guided to the lens of the sealing resin 4.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a resin-sealed light emitting body in which a light emitting semiconductor element is sealed with a translucent resin.

[0002]

[Prior Art]

 FIG. 5 shows a typical resin-sealed light-emitting body used in a light-emitting display device and the like. This resin-sealed light emitter has two lead frames 1, 1. A recess 1a is provided at the tip of one of the lead frames 1, and the light emitting semiconductor element 2 mounted therein is wire-bonded to the other lead frame 1. Then, with the light emitting semiconductor element 2 in the recess 1a as the center, the tip portions of the lead frames 1, 1 are embedded in the sealing resin 4. The end surface of the sealing resin 4 is formed in a hemispherical shape to form a convex lens for condensing light.

Light emitted from the light emitting semiconductor element 2 or the concave portion 1a of the element mounting portion is condensed by the lens formed of the sealing resin 4 and exhibits desired directivity and frontal strength. Condensation by this lens is governed by the L value (distance from the light emitting surface to the center of the lens) and the lens diameter. The directivity and the frontal strength are substantially determined by these two factors. Generally, when all the light enters the lens, the directivity gradually narrows and the frontal strength increases as the lens diameter decreases. Figure 6 shows this directional pattern. Utilizing the relationship between the lens diameter and the directivity, as shown in FIG. 7, a resin-sealed light-emitting body having a narrow directivity and a high front strength, in which only the central portion of the front surface of the sealing resin 4 is a lens 4a. Has also been developed.

[0004]

[Problems to be solved by the device]

 However, in the conventional resin-sealed light-emitting body, when the lens diameter becomes smaller than a certain value, a part of the light emitted from the recess of the light-emitting semiconductor element or the element mount part does not enter the lens (see FIG. 7). .. As a result, the front strength is reduced. In addition, when a light emitting semiconductor element whose electrode is located at the center is used, the electrode portion of the element does not emit light. Therefore, if the lens diameter is reduced to narrow the directivity, the directivity becomes 2 as shown in FIG. It becomes a mountain type. Therefore, also in this case, the front strength is lowered.

The present invention was devised in view of such circumstances, and an object of the present invention is to provide a resin-sealed light emitting body capable of preventing a decrease in frontal strength when the lens diameter is reduced.

[0006]

[Means for Solving the Problems]

 The resin-sealed light-emitting device according to the present invention is a resin-sealed light-emitting device in which a light-emitting semiconductor element is mounted in the recess, and the recess is sealed with a resin having a lower refractive index than the sealing resin. The interface between the resin and the sealing resin is a concave surface that is recessed toward the light emitting semiconductor element side.

[0007]

【Example】

 Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a vertical cross-sectional view of a resin-sealed light emitting body showing an embodiment of the present invention, and FIG. 2 is a graph showing directional characteristics of the resin-sealed light emitting body of FIG.

The resin-sealed light emitting body has two lead frames 1, 1. A recess 1a is provided at the tip of one lead frame 1, and the light emitting semiconductor element 2 mounted therein is wire bonded to the other lead frame 1 by a gold wire 3. The tip portions of the lead frames 1 and 1 are embedded in the sealing resin 4 except in the recess 1a. The encapsulating resin 4 has a semi-spherical projection at the center of the tip surface located in front of the concave portion 1a to form a small-diameter convex lens 4a for condensing light. The refractive index of the sealing resin 4 is, for example, 1.5.

A resin 5 having a lower refractive index than the sealing resin 4 is filled in the recess 1 a of the lead frame 1. When the sealing resin 4 has a refractive index of 1.5, a stress-releasing pre-coat resin (refractive index 1.4) can be used as the resin 5. The resin 5 seals the light emitting semiconductor element 2 in the recess 1 a and is in close contact with the sealing resin 4. The interface between the sealing resin 4 and the resin 5 is a concave surface that is recessed toward the light emitting semiconductor element 2 side. This concave surface can be formed by utilizing the surface tension of the resin 5, for example.

In this resin-sealed light-emitting body, the light emitted from the light-emitting semiconductor element 2 is reflected directly or on the inner surface of the recess 1 a, passes through the resin 5 in the recess 1 a, and is sealed by the sealing resin 4. Inject into. Since the interface between the sealing resin 4 and the resin 5 is a concave surface, and the refractive index of the resin 5 is smaller than that of the sealing resin 4, the resin 5 is changed to the sealing resin 4. The incident light is condensed at the interface. That is, the resin 5 functions as a condensing pseudo lens. Therefore, in the conventional resin-sealed light-emitting body, the light protruding from the lens 4a of the sealing resin 4 can also be guided into the lens 4a. Therefore, it is possible to prevent a decrease in frontal strength when the lens diameter is reduced, and to realize narrow directivity and high frontal strength. Even when the electrode is located at the center of the light emitting semiconductor element 2, the bidirectional tendency of the directivity (see FIG. 8) is alleviated by the light condensing function of the interface between the sealing resin 4 and the resin 5, and the front strength is reduced. Can be increased.

FIG. 3 is a vertical cross-sectional view of a resin-sealed light emitter showing another embodiment of the present invention. This resin-sealed light-emitting body is an SMD (Surface Mount Device) type and has an insulating substrate 7 on which a pattern 6 is formed by plating. A concave portion 7 a for mounting the light emitting semiconductor element 2 is provided on the surface of the insulating substrate 7. The light emitting semiconductor element 2 in the recess 7 a is wire-bonded to the pattern 6 by the gold wire 3. A resin 5 having a smaller refractive index than the sealing resin 4 is filled in the recess 7a, and the interface with the sealing resin 4 is a concave surface. The sealing resin 4 is laminated on the surface of the insulating substrate 7 and has a convex lens 4a at the center. Also in the present resin-sealed light-emitting body, narrow directivity and high front strength are realized by the light-collecting function at the interface between the sealing resin 4 and the resin 5.

FIG. 4 is a vertical sectional view showing still another embodiment of the present invention. In the embodiment described above, a part of the front surface of the sealing resin 4 is used as a lens, whereas in the present embodiment, the entire front surface of the sealing resin 4 is used as a lens.

[0013]

[Effect of the device]

 As described above, in the case of the resin-sealed light emitting device according to the present invention, the inside of the recess in which the light emitting semiconductor element is mounted is sealed with a resin having a lower refractive index than the sealing resin, and the resin and the By making the interface with the sealing resin a concave surface, a pseudo-concave lens is formed on the incident side of the lens by the sealing resin, and a condensing function is added, so even if the lens diameter is small, The entire amount can be made incident on the lens, and the frontal strength can be further increased. Further, even when the electrode is located at the center of the light emitting semiconductor element, the light condensing function of the pseudo lens alleviates the tendency of two directivity peaks and increases the frontal strength. Therefore, narrow directivity and high frontal strength are realized.

[Brief description of drawings]

FIG. 1 is a vertical cross-sectional view of a resin-sealed light emitting body showing an embodiment of the present invention.

FIG. 2 is a graph showing directional characteristics of the resin-sealed light emitting device of FIG.

FIG. 3 is a vertical cross-sectional view of a resin-sealed light emitting body showing another embodiment of the present invention.

FIG. 4 is a vertical sectional view showing still another embodiment of the present invention.

FIG. 5 is a vertical sectional view of a conventional resin-sealed light emitting body.

FIG. 6 is a graph showing directional characteristics of a conventional resin-sealed light emitting body.

FIG. 7 is a vertical sectional view of a conventional resin-sealed light emitting device aiming at narrow directivity and high frontal strength.

FIG. 8 is a graph showing directivity when an electrode is located at the center of a light emitting semiconductor element.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lead frame 1a Recess 2 Light emitting semiconductor element 4 Resin 5 for encapsulation 7 Resin in recess 7 Insulating substrate 7a Recess

Claims (1)

[Scope of utility model registration request] 1. A resin-sealed light-emitting body having a light-emitting semiconductor element mounted in a recess, wherein the recess is sealed with a resin having a refractive index lower than that of a sealing resin. A resin-sealed light-emitting body, characterized in that the interface with the resin for use is a concave surface depressed toward the light-emitting semiconductor element side.