JPH0715029A - Optically coupled device - Google Patents

Abstract

PURPOSE:To realize low cost by improving productivity and yield in an optically coupled device having an almost island-shaped mounting segment. CONSTITUTION:In an optically coupled device wherein a light emitting element 1 and a photodetector 2 are arranged at the optical coupling position, these are doubly transfer-molded by primary mold resin 5 and secondary mold resin 6, and at least the photodetector 2 is mounted on a mounting segment 3 which is cut so as to constitute an approximate island shape, a recessed part 7 is formed in the vicinity of a protruding part of the mounting segment 3 in the sealing part of the primary mold resin 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 device such as a photo coupler or a solid state photo relay.

[0002]

2. Description of the Related Art Conventionally, the structure of a light-receiving chip (lateral structure) is used in a dual in-line resin-sealed optical coupling element such as a dial-in-line package (DIP) or a surface mounting type surface mounting device (SMD). As for the output, two terminals and one terminal for mounting the light receiving chip are provided, and normally three terminals are provided.

FIG. 3 is a view showing a conventional example thereof, FIG. 3 (a) is a side sectional view, and FIG. 3 (b) is a perspective view from the upper surface side.

Reference numeral 1 is a light emitting element, 2 is a light receiving element, 3 is a mounting lead (mounting piece), 4 is an external lead terminal, 5 is a primary mold resin, and 6 is a secondary mold resin. It is the next mold resin.

However, in the conventional example shown in FIG. 3, since the mounting leads 3 are exposed to the outside, problems such as erroneous wiring and external noise occur. Therefore, as a solution to these problems, there is an optical coupling element as shown in FIG.

FIG. 4 is a view showing another conventional example, FIG. 4 (a) is a side sectional view, and FIG. 4 (b) is a perspective view from the upper surface side. This conventional example will be described only on the points different from the above conventional example.

In the optical coupling element of this conventional example, as shown in FIG. 4, the mounting lead 3 is subjected to lead cutting after primary molding,
After that, these are sealed with a secondary mold, and the mounting leads 3 are sealed so as not to be exposed to the outside.

[0008]

However, in the conventional example shown in FIG. 4, when the mounting lead 3 is cut, it is necessary to prevent the primary mold resin 5 near the cut portion from cracking or chipping. Yes, it is necessary to cut the primary mold resin 5 leaving about 0.5 mm.

This causes the following problems.

The thickness of the secondary molding resin 6 is about 0.8 mm in the DIP type, and there is a concern that the mounting lead 3 on the cut surface is exposed when the deviation occurs due to the secondary molding die.

Further, in the SMD, the thickness of the secondary molding resin 6 is about 0.3 mm, which is exposed from the secondary molding resin 6 and it is difficult to seal it in the secondary molding resin 6. .

When the amount of cutting residue is reduced, the durability of the die for lead cutting is lowered, or the primary molding resin 5 is bitten to cause cracks or chips in the primary molding resin 5 as described above. . Further, it is conceivable to increase the thickness of the secondary mold resin 6 and decrease the thickness of the primary mold resin 5, but it is difficult to simply reduce the thickness of the primary mold resin 5 in view of the layout.

In view of the above problems, it is an object of the present invention to provide an optical coupling element which eliminates the exposure of the mounting leads to the outside and improves the productivity and the yield.

[0014]

The optical coupling element of the present invention comprises:
The light emitting element and the light receiving element are arranged at positions where they are optically coupled to each other, and these are primary-molded and secondary-molded, and at least the light-receiving element is cut so as to have a substantially island shape after the primary molding. The optical coupling element mounted on the mounting piece is characterized in that a recess is provided in the sealing portion of the primary mold resin in the vicinity of the protruding portion of the mounting piece.

[0015]

According to the above construction, since the optical coupling element of the present invention has a concave portion provided in the sealing portion of the primary mold resin in the vicinity of the projecting portion of the placing piece, the concave portion is placed in the concave portion. By cutting the piece, a margin with the thickness of the secondary molding resin can be obtained.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is a perspective view from the upper surface side showing an embodiment of the present invention.

In the figure, 1 is a light emitting element, 2 is a light receiving element, 3 is a mounting piece, 4 is an external lead terminal, 5 is a primary mold resin (translucent resin), 6 is a secondary mold resin (light-shielding resin), and 7 is a recess.

As shown in FIG. 1, in the optical coupling element of this embodiment, the light emitting element 1 and the light receiving element 2 are arranged at positions facing each other,
These are double-transfer molded with the primary molding resin 5 and the secondary molding resin 6. A recess 7 is formed in the sealing portion of the primary mold resin 5 in the vicinity of the projecting portion of the mounting piece 3, and the mounting piece 3 on which the light receiving element 2 is mounted is substantially island-shaped. It is configured to be cut into a shape.

The manufacturing method will be described below.

First, the light emitting element 1 and the light receiving element 2 are mounted on predetermined external lead terminals 4 and mounting pieces 3, respectively, and desired element-terminal connections are made. Next, the light emitting element 1 and the light receiving element 2 are arranged at positions facing each other, and sealed by primary transfer molding of the primary molding resin 5. This time,
The above-mentioned mounting piece 3 in the sealing portion of the primary mold resin 5
The concave portion 7 is formed in the vicinity of the protruding portion. After that, in the concave portion 7, the placing piece 3 is cut with a cutting die (not shown). Next, the outer periphery of these is completely resin-sealed by secondary transfer molding of the secondary molding resin 6 to obtain a finished product.

As described above, the concave portion 7 is provided in the sealing portion of the primary molding resin 5 in the vicinity of the projecting portion of the placing piece 3, and the placing piece 3 is cut by the concave portion 7 to form the secondary mold. The margin with respect to the thickness of the resin 6 can be taken, and even if a deviation occurs on the assembly, the above-mentioned mounting piece 3 is not exposed to the outside, productivity is improved, yield is increased, and cost is reduced. It will be possible.

In addition, in the above embodiment, as shown in FIG. 2, by providing a plurality of grooves 8 on the outer periphery of the primary molding resin 5, the primary molding resin 5 and the secondary molding resin 5 when the secondary molding resin 6 is thinned. The adhesion of the resin 6 can be improved and the creepage distance can be increased.

The present invention is not limited to the above embodiment, but at least a concave portion 7 is provided in the sealing portion of the primary molding resin 5 in the vicinity of the protruding portion of the mounting piece 3 on which the light receiving element 2 is mounted, and the concave portion 7 is provided. Any material may be used as long as the piece 3 is cut.

For example, in the above-mentioned embodiment, the light emitting element 1 and the light receiving element 2 are arranged at positions facing each other, but they may be arranged on substantially the same plane.

[0025]

As described above, according to the optical coupling element of the present invention, the mounting piece is not exposed to the outside, the productivity is improved, the yield is increased, and the cost is reduced. can get.

[Brief description of drawings]

FIG. 1 is a perspective view from the upper surface side showing an embodiment of the present invention.

FIG. 2 is a side sectional view showing another embodiment of the present invention.

3A and 3B are views showing a conventional example, FIG. 3A is a side sectional view, and FIG. 3B is a perspective view from the upper surface side.

4A and 4B are views showing another conventional example, in which FIG. 4A is a side sectional view and FIG. 4B is a perspective view from the upper surface side.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Light emitting element 2 Light receiving element 3 Mounting piece 5 Primary molding resin 6 Secondary molding resin 7 Recess

Claims (1)

[Claims] 1. A light-emitting element and a light-receiving element are arranged at positions where they are optically coupled to each other, and these are primary-molded and secondary-molded. At least the light-receiving element has a substantially island shape after the primary molding. In an optical coupling element mounted on a mounting piece that has been cut so that an optical coupling element is provided, a concave portion is provided near a protruding portion of the mounting piece in the sealing portion of the primary mold resin. element.