JPH08767Y2 - Light emitting element - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a light emitting device having a sphere particularly suitable for distance measurement and projection.

(B) Conventional Technology Conventionally, a light-transmitting sphere (microlens) is placed on a light emitting diode made of a compound semiconductor in order to narrow the light flux or increase the light extraction efficiency.
This is disclosed, for example, in JP-A-60-140771 and JP-A-60-161684.
It is shown in the publication. In such a light emitting device, a sphere is placed at the center of a substantially cubic light emitting diode, which is used for optical communication and optical fibers. The use of the sphere is also effective in the light emitting element for projecting light used for measuring the distance of the automatic focusing device or the like, but the productivity is not so good. First, in order to prevent wiring materials (eg, beam leads or wire bond thin wires) from hindering the placement of spheres, semiconductors (light emitting diodes) are used.
That is, the size of one side becomes larger. Not only does this reduce the number of wafers taken per wafer, but in many cases these light emitting elements are often devised such as current constriction means.
Since defects are likely to occur, if the number of taken defects is small, the ratio of these defects to the whole becomes high.

Also, in these light emitting elements, the positioning of the spheres and the mounting work are devised by making holes in the semiconductor or providing protrusions for positioning in the above-mentioned materials, but both are not preferable because of complicated work. .

(C) Problems to be Solved by the Invention The present invention has been made in consideration of the above points, and provides a light-emitting device with high productivity.

(D) Means for Solving the Problems The present invention is one in which a sphere is placed on a compound semiconductor having a rhombic surface, and more preferably, the length of the shorter diagonal of the rhombus is approximately equal to the diameter of the sphere. It is something to do.

(E) Action By this, the wiring part can be projected from the sphere mounting part without taking a complicated element shape, the element does not become unnecessarily large, and the outer shapes of the sphere and the compound semiconductor are substantially the same. Because it is easy to place.

(F) Embodiments FIG. 1 is a perspective view of a light emitting device of an embodiment of the present invention, and FIG. 2 is a sectional view of a main part of a projector using the light emitting device. In these figures, (1) is a compound semiconductor such as a GaAs infrared light emitting diode, a single heterojunction light emitting diode or a double heterojunction light emitting diode, which is made of GaAlAs / GaAs or the like having a light emitting PN junction (11), and more preferably Current confinement means consisting of PN reverse bias structure (12)
Due to (12), a current concentration region (13) having a circular shape or the like is provided only in the substantially central portion. The back surface is provided with an ohmic electrode (14) on the entire surface, and the front surface is provided with a surrounding electrode (16) in the peripheral portion such that the light extraction portion (15) is formed at the substantially central portion. Since this compound semiconductor (1) is in the shape of a diamond cake, the surrounding electrode (16) has a diamond shape with a circular hole in the center. (2) is a translucent sphere made of glass spheres or the like placed on the light extraction section (15).

Such a light emitting element is fixed to, for example, a conductor stem (30) or the like with a conductive adhesive, and its wiring is made by a wire bond thin wire (31) or the like on the longer diagonal of the surrounding electrode (16). Be done. The sphere (2) is surrounded by the surrounding electrode (1
Although it is dropped into the hole of 6), it is better to provide the hole (light extraction part (15)) larger than the contact area of the spherical body (2) because the light extraction efficiency is better, so the center alignment is necessary. At this time, if the length of the diagonal line on the shorter side of the surrounding electrode (16) and the diameter of the sphere (2) are set to be substantially the same length, the alignment is easy. still,
When more accurate center alignment is required, recesses (17) (17) of about 30 μm, which serve as alignment marks for the ends of the spherical body (2), are formed on the longer diagonal line of the surrounding electrode (16).
Should be provided. Further, a sticking agent (4) or an adhesive may be used so that the sphere (2) does not move. Furthermore, for light projection, the refractive index of the sphere (2) (1.9 for glass)
Is too large and the luminous flux becomes too thin, which is often inconvenient for distance measurement. In this case, it is preferable to cover the entire light emitting element with the light-transmissive resin coating (5) because light can be projected in a form in which the light-collecting characteristics of the sphere (2) are reduced.

With the above configuration, for example, a sphere (2) having a diameter of 500 μm is conventionally used as a semiconductor having a square of 700 μm on a side, and 1500 semiconductors are obtained from one wafer. And a short diagonal 500μm and a long diagonal 600μm in a diamond shape, 250 from the same size wafer
We were able to obtain 0 semiconductors.

(G) Effect of the Invention As described above, according to the present invention, the wiring portion can be projected from the spherical body mounting portion without taking a complicated element shape, and the element does not become unnecessarily large. Furthermore, since the diameter of the sphere and one of the surface diagonals of the compound semiconductor are substantially equal, the work of placing the sphere can be easily performed with reference to the edge of the semiconductor, and the workability is excellent even in mass production. It can be effective.

[Brief description of drawings]

FIG. 1 is a perspective view of a light emitting device according to an embodiment of the present invention, and FIG. 2 is a sectional view of an essential part of a projector using the light emitting device. (1) …… Compound semiconductor, (15) …… Light extraction part, (16)
...... Surrounding electrode, (2) …… Sphere.

Claims (1)

[Scope of utility model registration request] 1. A light emitting device having a surrounding electrode on the peripheral portion of the surface of the compound semiconductor so that the substantially central portion of the surface thereof becomes a light extraction portion, and a translucent sphere is mounted on the light extraction portion. The compound semiconductor is a square prism with a diamond-shaped surface,
The light emitting device characterized in that the rhombic surface has a diagonal line having a length substantially equal to the diameter of the sphere and a diagonal line longer than the length.