JPH0653540A - Optical coupling element - Google Patents

Abstract

PURPOSE:To provide an optical coupling element in which thickness of package is reduced. CONSTITUTION:A first frame 3 couples a light emitting element 1 electrically and mechanically whereas a second frame 4 holds a light receiving element electrically and mechanically. A first mold body of translucent epoxy resin holds the first and second frames 3, 4. A second mold body 6 of opaque material wraps the outer periphery of the first mold body 5 entirely. Outer side faces of the first and second frames 3, 4 are set flush with the outer peripheral surface of the first mold body 5.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical coupling element such as a photocoupler or a solid-state relay which optically couples a light emitting element and a light receiving element and outputs a signal corresponding to a signal input to the light emitting element from the light receiving element. It is a thing.

[0002]

2. Description of the Related Art Conventionally, as an optical coupling element of this kind, as shown in FIG. 3, a light emitting element 1 such as a light emitting diode and a light receiving element 2 such as a photodiode or a photothyristor are opposed to each other. Held by the first mold body 5 made of a translucent material such as epoxy resin,
There is provided a structure in which the outer periphery of the first mold body 5 is wrapped around the entire periphery by a second mold body 6 formed of an opaque material. That is, the package 7 is constituted by the first mold body 5 and the second mold body 6. Light emitting element 1 and light receiving element 2 are electrically and mechanically coupled to first frame 3 and second frame 4, respectively. Further, parts of the first frame 3 and the second frame 4 project from the second mold body 6 to form terminals of the light emitting element 1 and the light receiving element 2. The portion holding the light emitting element 1 in the first frame 3 and the light receiving element 2 in the second frame 4
Is held in the first mold body 5 and is usually separated from the outer peripheral surface of the first mold body 5 by predetermined dimensions t ₁ and t _2. is there.

[0003]

With the above configuration, the SOP
(Small outline package), a small package 7
However, there is a problem in that the height dimension tends to be larger than that of other SOPs such as integrated circuits. This is because it is necessary to make the distance between the facing surfaces of the first frame 3 and the second frame 4 as large as possible in order to secure the withstand voltage between the input and output, and the first frame 3 and the second frame 4. This is because the frame 4 is embedded in the first mold body 5.

An object of the present invention is to solve the above-mentioned problems, and it is an object of the present invention to provide an optical coupling element in which the thickness of the package can be made smaller than that of the conventional structure if the input / output withstand voltage is about the same. It is a thing.

[0005]

According to the present invention, in order to achieve the above object, a first frame 3 electrically and mechanically coupled to a light emitting element 1 and a light receiving element 2 electrically and mechanically are provided. The combined second frame 4 and the first frame 3 and the second frame 4 are arranged so that the light emitting element 1 and the light receiving element 2 face each other.
A first mold body 5 made of a translucent material that holds a part of the frame 4 facing each other, and a first mold body 5 wrapping the outer periphery of the first mold body 5 all around. And a second mold body 6 made of a non-translucent material that constitutes the package 7, and the outer surfaces of the first frame 3 and the second frame 4 are the same as the outer peripheral surface of the first mold body 5. They are aligned on the surface.

[0006]

In the configuration of the present invention, the outer surfaces of the first frame 3 and the second frame 4 are aligned with the outer peripheral surface of the first mold body 5, so that the first frame 3 is the same as the conventional one. The frame 3 and the second frame 4 are connected to the first molded body 5
In comparison with the case where the first mold 3 and the second frame 4 are buried in the outer peripheral surface of the first mold body 5 and the outer peripheral surface of the first mold body 5, the thickness dimension is equal to the distance (t ₁ + t ₂ ). Can be made smaller, and the thickness dimension of the package 7 can be made smaller. Although depending on the breakdown voltage between the input and output, the thickness dimension of the package 7 can be reduced by about 0.6 to 1.0 mm by adopting the configuration of the present invention.

[0007]

(Embodiment 1) In this embodiment, as shown in FIG. 1, the basic structure is the same as the conventional structure, and the light emitting element 1 is held in the first frame 3 and the second frame 4 is held. The light receiving element 2 is held by the light receiving element 2 and the light emitting element 1 and the light receiving element 2 are arranged to face each other. The first frame 3 and the second frame 4 are held by a first mold body 5 which is a translucent material made of white epoxy resin. Here, the first frame 3 and the second frame 4
Of the outer surface of the first frame 3, that is, the surface opposite to the light emitting element 1 in the first frame 3 and the surface opposite to the light receiving element 2 in the second frame 4 are the same as the outer peripheral surface of the first mold body 5. It is aligned with. Therefore, the first mold body 5 in the direction connecting the light emitting element 1 and the light receiving element 2
The thickness dimension of is smaller than that of the conventional configuration by (t ₁ + t ₂ ). The outer periphery of the first mold body 5 is covered with a second mold body 6 made of an opaque synthetic resin that is black over the entire circumference to block outside light.

According to the above structure, if the other structures except the first mold body 5 are formed to have the same dimensions as the conventional structure shown in FIG. 3, the withstand voltage between the input and output is the same as that of the conventional structure. It is possible to reduce the thickness dimension of the package 7 while maintaining the same level. Therefore, when a small SOP is formed, it is possible to set the height to the same level as the SOP of other integrated circuits.

(Embodiment 2) In this embodiment, as shown in FIG. 2, a light transmitting portion 8 made of a transparent silicon resin is formed at the facing portions of the light emitting element 1 and the light receiving element 2. In the configuration of the first embodiment, the light emitting element 1 and the light receiving element 2 are opposed to each other through the first mold body 5 which is a white epoxy resin. Therefore, the light emitting element 1 and the light receiving element 2 are disposed between the first frame 5 and the second frame 6. The breakdown voltage (breakdown voltage between input and output) can be increased, but the light transmittance is relatively small and the sensitivity is low. That is, since the amount of light received by the light receiving element 2 is relatively small, the output of the light receiving element 2 causes the FET
When a switching element such as a photothyristor is used as the light receiving element 2 for turning on / off such a switching element as described above, it takes a long time from the lighting of the light emitting element 1 to the response of the switching element and the output capacitance. Is limited. Although such a problem can be solved by increasing the amount of light emitted from the light emitting element 1, there arises a problem that the driving power of the light emitting element 1 increases. Further, it is conceivable to reduce the distance between the light emitting element 1 and the light receiving element 2, but in that case, there arises a problem that the withstand voltage between the input and the output becomes small.

Therefore, since the light transmitting portion 8 is formed at the opposing portion of the light emitting element 1 and the light receiving element 2, the first mold body on the optical path from the light emitting element 1 to the light receiving element 2 is formed by this structure. Therefore, the thickness dimension of No. 5 is reduced and the amount of light reduction is reduced. As a result, the efficiency of light transmission from the light emitting element 1 to the light receiving element 2 is increased, and a highly sensitive optical coupling element can be provided. In order to form the light transmitting portion 8 at the time of manufacturing, transparent silicon resin is applied to the light emitting element 1 and the light receiving element 2 held by the first frame 3 and the second frame 4 so as to be raised (potting).
do it. Moreover, since the first frame 3 and the third frame 4 are isolated from each other by the first mold body 5 made of epoxy resin, the withstand voltage between the input and the output is almost the same as when the light transmitting portion 8 is not provided. There is no change. For example,
Since the withstand voltage between the input and the output can be set to 5 kV or more, such a high withstand voltage cannot be realized only by the silicon resin, and a part of the first mold body 5 made of the epoxy resin is not covered with the silicon resin. By providing the light transmission portion 8, it is possible to satisfy the contradictory conditions of the light transmission efficiency and the high breakdown voltage. Other configurations are similar to those of the first embodiment.

[0011]

As described above, according to the present invention, the surface of the first frame holding the light emitting element and the surface of the second frame holding the light receiving element opposite to the facing surface and the outer peripheral surface of the first molded body are provided. Are aligned on the same plane, the thickness of the first mold body in the direction connecting the light emitting element and the light receiving element should be reduced as compared with the conventional configuration if the withstand voltage between the input and the output is the same. This has the advantage that the thickness dimension of the package can be reduced. That is, even when a small package is formed, it is possible to form the package with the same height as the package of other components.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a first embodiment.

FIG. 2 is a cross-sectional view showing a second embodiment.

FIG. 3 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 1 Light-Emitting Element 2 Light-Receiving Element 3 First Frame 4 Second Frame 5 First Molded Body 6 Second Molded Body 7 Package

Claims (1)

[Claims] 1. A first frame electrically and mechanically coupled to a light emitting element, a second frame electrically and mechanically coupled to a light receiving element, and a light emitting element and a light receiving element facing each other. And a first mold body made of a light-transmissive material that holds a part of the first frame and the second frame in opposition to each other, and a first mold body that is wrapped around the entire circumference of the first mold body. A second mold body made of a non-translucent material forming a package together with the first mold body, and the outer surfaces of the first frame and the second frame and the outer peripheral surface of the first mold body are the same surface. An optical coupling element characterized in that