JPH0469981A - Optical semiconductor device - Google Patents

Abstract

PURPOSE:To obtain an optical semiconductor device of a structure adapted for reduction in size in which a light from a light emitting chip is not leaked to the side of a photodetecting chip in a state that a strength is maintained by burying opaque resin in transparent resin between the emitting chip and the photodetecting chip. CONSTITUTION:When a light emitting chip 3, a photodetecting chip 4 are mounted on flat plates 1a, 1b of a lead frame and molded with transparent resin 5, its strength is maintained, a light from the chip 3 is disturbed to be propagated by opaque resin 8 and not leaked to the side of a photodetecting chip. Since the resin 8 is buried in the resin 5, a shape is not enlarged by the resin 8.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention has a lead frame with a light emitting chip mounted on one of two flat plate parts (die islands) and a light receiving chip mounted on the other, and the whole is made of transparent resin. The present invention relates to a molded optical semiconductor device, and particularly to a structure for preventing light from a light emitting chip thereof from leaking through resin to a light receiving chip side.

[Conventional technology]

FIGS. 4(a) and 4(b) show the structure of an example of a conventional optical semiconductor device of this type.

In the figure, la and lh are flat plate parts (die islands) of the lead frame, 2a, 2b, and 2e are external leads, 3 is a light emitting chip, 4 is a light receiving chip, and 5 is a transparent resin.

FIG. 5 shows the structure of a lead frame used in the optical semiconductor device of FIG. 4.

In the figure, la, lb, 2a, 2b, and 2e indicate the same parts and symbols as in FIG. 4, and 7 is a part of the tie bar.

A light emitting chip 3 is mounted on one flat plate part 1a of the lead frame, a light receiving chip 4 is mounted on the other flat plate part 1b, and the bonding pads of the light emitting chip 3 and the light receiving chip 4 are bonded to the tips of external leads 2a and 2b, respectively. It is manufactured through the steps of connecting with wires (not shown), molding the entire body with transparent resin 5, and then cutting and removing a portion of the tie bar 7.

In the structure described above, the - part of the light traveling from the light emitting chip 3 through the resin 5 in the direction indicated by the arrow in the figure enters the light receiving chip 4 and is output as noise.

Conventionally, in order to solve the above problem, a structure was adopted in which the distance within the resin 5 between the light emitting chip 3 and the light receiving depth 4 was increased, as shown in FIG. light emitting part,
It was possible to completely separate the transparent resin between the light-receiving parts1.7, and to cover the outside with an opaque resin ε or b''-2 to compensate for the lack of strength.

[Problems that the invention will solve]

Conventionally, the structure described above, which has been adopted in this type of optical semiconductor device to prevent light from the light-emitting chip from leaking to the light-receiving chip side, has the disadvantage of being large in size.
was.

The present invention has been made to solve the above problems.1
(1) To provide an optical semiconductor device having a structure suitable for miniaturization, in which light from a light emitting chip does not leak to the light receiving chip side while the intensity is maintained.

[11 Steps to Solve the Problems] The optical semiconductor device of the present invention has 5. In order to prevent the light from the light emitting chip from leaking to the light receiving chip side C, 12. The light is emitted and the light is received by the tubes.The transparent resin between the tubes is opaque. It has a structure in which resin 4 is embedded.

〔Example〕

FIGS. 1(a), (b), and (c) are examples of the embodiments of the present invention. iReiji'11'.

In the figure °ζ', 1a, lh-2a, 2h92c, 3
, 4+ 5 indicates the same or corresponding part as No.-i in FIG. 4, and 8 indicates opaque resin C.

FIG. 2 shows the structure of the t7 frame used in the embodiment of FIG.

In the figures, 1a, 1b, 2a, 2b, 2c, and 8 indicate the same parts as those shown in FIG.

A light-emitting chip 3 and a light-receiving chip 4 are mounted on the flat plate parts 1a and lb of this lead frame, respectively 7, and a transparent resin is already molded into the structure shown in FIG. 1(a), for example.
In addition to maintaining the intensity, the light from the light emitting chip 3 is blocked from progressing by the opaque resin 8, and no leakage occurs due to the eccentricity of the light receiving chip.

By using the lead frame having the above structure, it is not necessary to cut and remove the tie bar part 7 after molding with the resin 5 as in the conventional case, and the mechanical stress applied to the external leads is reduced.

FIG. 3 shows the structure of another embodiment of the invention.

For the lead frame, for example, one with a conventional structure as shown in FIG. This method employs a method of embedding.

In the structure of the present invention, the opaque resin 8 is embedded within the transparent resin 5, so the opaque resin 8 does not increase the size.

〔Effect of the invention〕

As described above, according to the present invention, it is possible to completely prevent light leakage from the light emitting chip to the light receiving chip side within the resin without increasing the size of the device or reducing its strength.

[Brief explanation of the drawing]

Figures 1 (a), (b), and (C) are explanatory diagrams of the structure of one embodiment of the present invention, and Figure 2 is a diagram of the structure used in the embodiment of Figure 1. FIG. 3 is an explanatory diagram showing the structure of another embodiment of the present invention, and FIGS. 4(a) and (b) are explanatory diagrams showing the structure of an example of a conventional optical semiconductor device of this type. FIG. 5 is a perspective view showing the structure of a lead frame used in the optical semiconductor device of FIG. 4, and FIG. 6 is a perspective view showing the structure of a lead frame used in the optical semiconductor device of FIG. FIG. 7 is an explanatory diagram showing a structure conventionally adopted in this type of optical semiconductor device to prevent light from leaking from the light emitting chip inside the resin to the light receiving chip side. 1a, 1b...flat plate part, 2a, 2b, 2e
- External lead, 3... Light emitting chip, 4... Light receiving chip, 5... Transparent resin, 8... Opaque resin Note that the same reference numerals in the drawings indicate the same or corresponding parts 1゜Patent Applicant New Japan Radio Co., Ltd. 3 Light emitting chip 4. Light receiving chip 5/transparent resin 8 Opaque resin No. 4 No. 6 Expansion (a) (c) Fig. 7

Claims (1)

[Claims] A light emitting chip is mounted on one of two flat plate parts (die islands) of a lead frame, a light receiving chip is mounted on the other, and bonding pads of each chip are connected to external leads with bonding wires, In an optical semiconductor device that is entirely molded with transparent resin, an opaque resin is embedded in the transparent resin between the light emitting chip and the light receiving chip to prevent light from the light emitting chip from leaking through the resin to the light receiving chip. An optical semiconductor device characterized by: