JPH06196747A - Optically coupled device - Google Patents

Abstract

PURPOSE:To provide an optically coupled device having a high breakdown strength at a low cost in which the number of parts can be reduced and a manufacturing process can be simplified. CONSTITUTION:Both of a light emitting device 2 and a light receiving device 3 respectively mounted on a lead frame 1 are placed, and both of the devices 2 and 3 are respectively potted with a rubber transparent resin 10, and an optical coupling path is formed between both of potting parts by a gel transparent resin 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical coupling device in which an input / output side is electrically insulated by converting an electric signal into an optical signal by a light emitting element and converting the signal into an electric signal again by a light receiving element. Regarding

[0002]

2. Description of the Related Art A conventional technique will be described with reference to FIG. FIG. 3 is a sectional view of a conventional optical coupling device.

As shown in FIG. 3, the conventional optical coupling device is
Between the light emitting element 2 and the light receiving element 3 respectively mounted on the lead frame 1, a transparent plastic 4 serving as an optical coupling path for preventing resin dripping is arranged and covered with a single transparent silicone resin 5. Further, the transparent silicone resin 5 was covered with the reflective resin 6, and the whole was molded with the light-shielding resin 7. In the above structure, the light emitted from the light emitting element 2 enters the light receiving element 3 through the silicone resin 5 and the transparent plastic 4 or is reflected by the reflective resin 6. As another conventional example, there is one in which the reflective resin 6 is used instead of the light-shielding resin 7 and molded with a single resin.

[0004]

By the way, according to the above-mentioned prior art, since the mounting portion of the light emitting element 2 and the mounting portion of the light receiving element 3 are separated from each other in order to secure the dielectric strength, the transparent silicone resin 5 has a high viscosity. In the case of a low gel-like resin, resin dripping occurs from the gap between both elements before it is cured. In order to prevent this, it was indispensable to arrange the above-mentioned transparent plastic 4. As a result, the number of manufacturing processes increases and
The number of parts was also large, which was a factor of cost increase.

On the other hand, when a resin having a high viscosity is used as the transparent silicone resin 5, the above-mentioned resin dripping does not occur, and the transparent silicone resin 5 has poor adhesiveness, so that the interface with the reflective resin 6 is formed. Although there is a merit that a gap is formed without being in close contact and the light reflection efficiency is increased by this gap, there is a problem that the withstand voltage is lowered.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide an optical coupling element having a simple structure, high withstand voltage and improved light transmission efficiency.

[0007]

In order to achieve the above object, the optical coupling device of the present invention comprises a light emitting element and a light receiving element, which are mounted on a lead frame, respectively, and both of the elements are made of a rubber-like transparent resin. It is characterized in that it is potted, and an optical coupling path made of a gel-like transparent resin is formed between the both potting portions.

[0008]

In the optical coupling device of the present invention, as described above, since each of the light emitting and receiving elements is covered with the rubber-like resin,
The resin gap between both elements becomes narrower, and no resin dripping occurs even if a gel-like resin is injected between them. Therefore, even if the light receiving and emitting areas are separated from each other to secure a high withstand voltage, it is not necessary to arrange a transparent plastic between the light receiving and emitting areas as in the conventional case, and the number of parts can be reduced and the manufacturing process can be simplified, resulting in cost reduction You can go down. Further, since this transparent silicone resin is a gel type, a higher withstand voltage can be secured.

Further, since the rubber-like resin has low adhesiveness, a gap is formed between the rubber-like resin and the gel-like resin. Therefore, this gap improves the light reflection efficiency and thus the light transmission efficiency.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described with reference to FIGS.

FIG. 1 is a sectional view of an optical coupling device according to this embodiment, and FIGS. 2A and 2B are views showing a manufacturing process of an optical coupling device according to this embodiment.

The same functional parts as those of the conventional example shown in FIG. 3 are designated by the same symbols.

As shown in FIG. 1, in the optical coupling device of this embodiment, each of the light emitting element 2 and the light receiving element 3 of the lead frame 1 is covered with a transparent silicone resin 10 of rubber type, and the space between both elements is of gel type. It is filled with a transparent silicone resin 11, and the whole is molded with a reflective resin 12. As the reflective resin 12, an epoxy resin mixed with a reflective material such as titanium oxide is used.

In the resin potting method of the optical coupling device having the above structure, as shown in FIG. 2A, first, a rubber type transparent silicone resin 10 is received and emitted by a potting device 14 having injection ports for both elements. At the same time, it is dropped and cured on the element, and then a gel type transparent silicone resin 11 is injected and cured between the light emitting and receiving elements by another potting device 15.

According to the present embodiment, since each of the light emitting and receiving elements is covered with the rubber type transparent silicone resin 10, the resin gap between the elements is narrowed, and the gel type transparent silicone resin 11 is provided therebetween. No resin dripping occurs when injected. Therefore, it is not necessary to dispose the transparent plastic 4 between the light emitting and receiving sides as in the conventional case even if the light receiving and emitting sides are separated from each other in order to secure a high withstand voltage, and the number of parts can be reduced and the manufacturing process can be simplified. The cost can be reduced. Further, since this transparent silicone resin 11 is a gel type, a higher withstand voltage can be secured.

Since the rubber type transparent silicone resin 10 has low adhesiveness, the gel type reflective resin 12 is used.
A gap 13 is formed between and. For this reason, the gap 13 improves the light reflection efficiency and thus the light transmission efficiency.

[0017]

As described above, according to the present invention, the number of parts can be reduced and the manufacturing process can be simplified, and an inexpensive optical coupling device with high withstand voltage and high light transmission efficiency can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view of an optical coupling device according to an embodiment of the present invention.

2A and 2B are views showing one manufacturing process of an optical coupling device according to an embodiment of the present invention.

FIG. 3 is a sectional view of an optical coupling device according to a conventional example.

[Explanation of symbols]

 1 Lead frame 2 Light emitting element 3 Light receiving element 10 Rubber-like transparent silicone resin 11 Gel-like transparent silicone resin

Claims (1)

[Claims] 1. A light-emitting element and a light-receiving element mounted on a lead frame, respectively, are arranged side by side, both elements are potted with a rubber-like transparent resin, and an optical coupling path made of a gel-like transparent resin is provided between the potting portions. An optical coupling device comprising: