JPS62281374A - Semiconductor device - Google Patents

Abstract

PURPOSE:To contrive accomplishment of efficient utilization of luminous flux by a method wherein a reflection mirror, desirably a concaved reflection mirror, is arranged in front of a semiconductor light emitting element or a light receiving element, and the back side of said element is used as the light projecting surface or the light receiving surface of the title semiconductor device. CONSTITUTION:A concave mirror 1, having a rotary paraboloid of curved surface formed by the locus of the point at equal distance from a fixed plane surface and a fixed point on the mirror face, is used as a reflecting mirror, a semiconductor light emitting element chip is arranged on the focus F, end the light emitting surface faces mirror-face of concave mirror 1. The light emitted from the light emitting element chip is converted into a parallel flux of light by the concave mirror 1, and the flux of light advances toward the rear of the chip. Said semiconductor light projecting device has the solid angle omega1 of 2pi steradians. Accordingly, not only the output light in optic-axial direction, but also the output light vertical to the optical axis can be utilized efficiently as the incident light.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention Summary of the Invention Conventionally, a lens was placed in front of a semiconductor light emitting element or a light receiving element to collimate, condense, and perform other functions. The device is characterized in that one reflecting mirror, preferably a concave reflecting mirror, is provided, and these element chips are arranged in opposite directions to the light emitting and light receiving surfaces of the light emitting and receiving device.

TECHNICAL FIELD OF THE INVENTION The present invention relates to a semiconductor device, and more particularly to a semiconductor light projector or a semiconductor light receiver.

Prior Art and its Problems This type of semiconductor device includes a semiconductor light emitting element or a semiconductor light receiving element. A light projecting device is equipped with some kind of optical system in order to condense or convert the output light of a light emitting element into parallel light, and a light receiving device is equipped with some kind of optical system in order to appropriately condense incident light onto a light receiving element. FIG. 5 shows an example of these conventional semiconductor devices. Figure (a) shows a resin-sealed type, in which the semiconductor light-emitting or light-receiving element is sealed with resin 1[
When sealing is performed, a portion 11a of this resin is formed into a hemispherical shape, and this portion is used as a resin lens. Figures (b) and (c) are of a metal stem type, and a glass lens 13 is provided on the front surface of the cap 12 which houses a semiconductor light emitting or light receiving element inside, or a window 12 of the cap 12 is provided.
A lens (not shown) is provided inside a.

In any case, in these conventional semiconductor devices, as shown schematically in an example of a light projecting device in FIG. A lens 15 (corresponding to LLa, 13, etc. in FIG. 5) constituting an optical system is arranged in front of the light receiving surface to condense or collimate light. However, when considering the utilization rate of the luminous flux, in this type of structure, there is insufficient light quantity and insufficient light receiving sensitivity in practical use, and semiconductor light emitting/
This often limits the performance of equipment that uses the light receiving device.

FIG. 7 shows the light distribution pattern of the light emitting diode.

As can be seen from this figure, a considerable amount of light is emitted from one light emitting diode not only in the direction of its optical axis V but also in the direction H perpendicular to the optical axis. However.

In the configuration shown in FIG. 6, the effective solid angle ω2 of the light beam emitted from the chip 14 is approximately (2/3)π steradian at most, and only light in the optical axis direction can be used. This effective solid angle is 2? If it can be made into radians, almost all of the emitted light can be used. This also applies to the light receiving device in almost the same way.

SUMMARY OF THE INVENTION OBJECTS OF THE INVENTION An object of the present invention is to provide a semiconductor device with high utilization of luminous flux.

Structure and Effects of the Invention The semiconductor device according to the present invention has a reflecting mirror, preferably a concave reflecting mirror, arranged in front of a semiconductor light emitting or light receiving element, and the rear side of this element is used as a light emitting surface or a light receiving surface of the device. Features.

With this configuration, the + conductor light emitter/receiver can theoretically have an effective solid angle of 2π steradians with respect to the luminous flux, making effective use of approximately three times the luminous flux compared to conventional systems. I can do it.

DESCRIPTION OF EMBODIMENTS FIG. 1 schematically shows the configuration of the present invention applied to a semiconductor light projector. As the reflecting mirror, a concave mirror 1 is used, which has a paraboloid of revolution on its v1 surface, which is a curved surface formed by the locus of points equidistant from one foot surface and one fixed point.
A semiconductor light emitting element chip is placed at the focal point F,
Its light emitting surface faces the mirror surface of the concave mirror 1. Light emitted from the light emitting element chip is converted into a parallel beam of light by the concave mirror 1, and travels toward the rear of the chip. With such a configuration, this semiconductor light projector has a solid angle ω1 of 2π steradians. As a result, not only the output light in the direction of the optical axis shown in FIG. 7 but also the output light in the direction perpendicular to the optical axis can be effectively used as projection light.

FIG. 2 shows an actual semiconductor light projector or semiconductor light receiver. An element chip [4] fixed on a lead frame 2 is sealed with a resin 3. There is a concave mirror 1 on the front side of the chip 14 of this resin 3, and the rear side is a light projecting surface or a light receiving surface 1Iiii3a. Lead
It is preferable that the frame 2 be as narrow as possible.

As an example, such a semiconductor device is manufactured as follows.

The conductive chip 14 is placed on the lead frame 2 and eight-wave wire bonding is performed, and then low-pressure molding is performed with Epoquin resin 3 using a molding die having a paraboloid of revolution. The molding temperature is 150 to 170°C and one hour is about 3 minutes.

Next, the entire molded product is placed in a vacuum evaporation apparatus, surfaces other than the paraboloid, such as the light-receiving surface 3a, are masked, and aluminum, for example, is vapor-deposited on the paraboloid side, thereby forming the concave mirror 1. .

Various shapes other than a paraboloid of revolution may be used as the concave reflecting mirror.

For example, as shown in FIG. 3, a reflecting mirror having an ellipsoid of revolution, which is a curved surface formed by the trajectory of points whose sum of distances from two fixed points is constant, has two focal points fl.

It has f. Therefore, when a light emitting element is placed at one focal point f1, the luminous flux thereof is focused on the other focal point f2. this is,
For example, it could be used as a means to make the convergent light enter the destination fiber with a 6° effect.

As shown in FIG. 4, a hyperboloid of revolution, which is a curved surface formed by the difference in distance from two fixed points or the locus of constant points, also has two focal points f and f2. When a light emitting element is placed at the focal point f of −h', the light beam reflected by this curved surface is reflected by q·1 as if it were radiated from another focal point f. As the element placed at the focal point f1, a light-receiving element is preferred rather than a single light-emitting element, and a reflecting mirror having such a reflective surface may be used in a light-receiving device.

As another example, the reflecting surface may be a curved surface formed by a locus of a straight line and a point with a constant difference in distance from a fixed point, such as a combination of curved surfaces of a paraboloid of revolution and a hyperboloid of revolution.

In this case, if a point light source is placed at the focal point of this curved surface, there will be parallel rays in one axis direction perpendicular to the optical axis, or diffused rays such as from a rotation hyperboloid in the other axis direction orthogonal to this. is emitted.

[Brief explanation of the drawing]

Fig. 1 is a sectional view for explaining the invention in detail;
The figures are cross-sectional views showing embodiments of the present invention, Figures 3 and 4.
The figure is a diagram showing an example of another curved surface of the reflecting mirror. Figures 5(a), (b) and (C) are side views showing examples of conventional semiconductor devices, Figure 6 is a sectional view schematically showing its IM configuration, and Figure 7 is a diagram showing the arrangement of light emitting diodes. It shows a light pattern. 1...Reflector, 2...Lead frame 13
...resin, 3a...light emitting surface or light receiving surface. 14...Light emitting element or light receiving element chip. Patent applicant Tateishi Electric Co., Ltd. Representative Patent attorney Kenji Ushiku (1 other person) Figure 1 Figure 3 Figure 4

Claims (1)

[Claims] A semiconductor device characterized in that a reflecting mirror is arranged in front of a semiconductor light emitting or light receiving element, and the rear side of this element is used as a light projecting surface or a light receiving surface of the device.