JPS6276684A - Reflected-light type light-coupled semiconductor device - Google Patents

Abstract

PURPOSE:To miniaturize a device and to simplify manufacturing processes, by a constitution, wherein light is emitted from only the limited region of the top surface of a semiconductor light emitting element, and the shape of a transparent resin layer and the distance between the light emitting element and a light receiving element are set so that the light, which is reflected by the surface of the transparent resin layer inward the resin layer, does not reach the semiconductor light receiving element. CONSTITUTION:A semiconductor light emitting element 13 is die-bonded to a header 11. A semiconductor light receiving element 14 is die-bonded to a header 12. Said light emitting element part and light receiving element part are sealed with a single transparent resin layer 15. Leads are extended from the headers 11 and 12 and a pad to the outside of the transparent resin layer 15. Light is emitted only from the limited region of the top surface of the semiconductor light emitting element 13. The expansion of the light from the light emitting element is suppressed so that the incident angle of the light, which is inputted to the surface of the transparent resin layer 15 from the light emitting element 13, does not become greater than the critical angle THETAc. The distance between both elements 13 and 14 is set so that the light, which is reflected by the surface of the transparent resin layer 15, does not reach the light receiving element 14.

Description

[Detailed description of the invention] , [Technical field of invention] The present invention relates to a reflective light type optically coupled semiconductor device.

[Technical background of the invention]

Reflected light type optically coupled semiconductor devices have a sensor function and are used in photoelectric switches, logic circuit connections, position detection, timing detection, and the like.

FIG. 4 is a perspective view showing an example of a conventional reflective light type optically coupled semiconductor device, and FIG. 5 is a sectional view taken along the line v--v in FIG. 4. In these figures, 1 is an envelope made of a light-shielding material such as ceramic. The envelope 1 has a surrounding wall 2,
It consists of a bottom wall 3 and a partition 4, and is provided with a recess for a light emitting element and a recess for a light receiving element, which are open at the top and separated by the partition 4. A semiconductor light emitting element 6 is die-bonded onto a header 5 for mounting an element provided on the bottom surface of the light emitting element recess. The semiconductor light emitting device 6 is connected to a pad 8 via a bonding wire 7. Furthermore, a semiconductor light receiving element 10 is die-bonded onto the header 9 provided on the bottom surface of the light receiving element recess. The semiconductor light receiving element 10 is connected to a pad 12 via a bonding wire 11. Leads 13 connected to each ladder and pad extend downward from the bottom wall 3 of the envelope. Both pixel element portions are sealed with a transparent epoxy resin layer 14.

In the optically coupled semiconductor device described above, light emitted from the semiconductor light emitting element 6 is reflected by an object, and this reflected light is transmitted to the light receiving element 1.
0 functions as a sensor by detecting it.

Other examples of conventional reflective light type optically coupled semiconductor devices are shown in FIGS. 6 to 8. In this example, as shown in FIG. 6, first, a lead frame equipped with two sets of headers and pads 5, 8, 9, and 12 is used for die bonding and wire bonding of a semiconductor light emitting device 6 and a semiconductor light receiving device 10, respectively. Perform bonding.

Next, as shown in FIG. 7, the light emitting element part and the light receiving element part are individually sealed with a transparent mold resin layer 14 14, and then the outside except for the top surface is shielded from light as shown in FIG. It is integrally molded using a synthetic resin mold 15.

[Problems with background technology]

In the case of the conventional example shown in FIGS. 4 and 5, the light emitting element 6 and the light receiving element 10 are mounted in a recess provided in advance,
Furthermore, since wire bonding is to be performed, each recess must have sufficient space within which a collet for gripping the element and a capillary for performing wire bonding can move. Therefore, there is a problem that miniaturization of the device is hindered. Also,
When resin sealing is performed, the surface of the resin layer 14.14 becomes a concave surface, which causes a problem of deterioration of directivity.

On the other hand, in the case of the conventional examples shown in FIGS. 6 to 8, each element portion must be individually resin-sealed with a transparent resin layer 14, 14 and then integrally molded with a light-shielding resin layer 15. Therefore, there is a problem that the process becomes complicated. In addition, the transparent resin layer 14
．． 14 and the light-shielding resin layer 15 is poor,
There are problems with reliability. Furthermore, there is a problem in that the structure of the envelope becomes larger due to the second resin molding.

[Purpose of the invention]

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a reflective light type optically coupled semiconductor device that can achieve miniaturization of the device, simplify the manufacturing process, and further improve reliability. .

[Summary of the invention]

A reflected light type optically coupled semiconductor device according to the present invention includes a semiconductor light emitting element and a semiconductor light receiving element which are each die-bonded onto separate headers and connected to separate pads via bonding wires, and a light emitting element portion and a semiconductor light receiving element. The semiconductor light emitting element includes a single transparent resin layer that integrally seals a light receiving element portion, and leads extending from each of the header and the pad to the outside of the transparent resin layer. emit light only from a limited area of the chip, do not emit light from other chip surfaces, and prevent light reflected from the surface of the transparent resin layer into the resin layer from reaching the semiconductor light-receiving element. The present invention is characterized in that the shape of the transparent resin layer and the distance between the two elements are set.

In the present invention, in order for the semiconductor light-emitting element to emit light only from a limited area on its top surface, the other surface of the light-emitting element may be covered with a light-shielding coating, for example.

In addition, in order to prevent the light reflected from the surface of the transparent resin layer from reaching the light-receiving element, it is necessary to The distance between both elements may be set so as to suppress the spread of light and prevent reflected light from hitting the light receiving element.

Since the device of the present invention does not use an envelope like the conventional example shown in FIGS. 4 and 5, the problems in that case do not occur at all. Further, since the resin molding only needs to be done once, the problems of the conventional examples shown in FIGS. 6 to 8 do not occur.

[Embodiments of the invention]

FIG. 1 is a sectional view of a reflection type optically coupled semiconductor device according to an embodiment of the present invention. In the figure, 11 and 12 are headers. A semiconductor light-emitting element 13 is die-bonded to the header 11, and a semiconductor light-receiving element 14 is die-bonded to the header 12. These pixel elements 13.14
are connected to respective pads (not shown) via bonding wires such as Au (not shown). These light emitting element parts and light receiving element parts are made of a single transparent resin (15
It is sealed in one piece. Also, each header 11.1
2 and a transparent resin layer 15 (not shown) from the pad.
It extends outward. As shown in the figure, the semiconductor light emitting device 13 emits light only from a limited area of its top surface. In addition, light emitting element 1
The spread of light from the light emitting element 13 is suppressed so that the angle of incidence of the light that enters the surface of the transparent resin layer 15 from the light emitting element 13 does not become larger than the critical angle θC. In addition, to prevent the light reflected from the surface of the transparent resin layer 15 from reaching the light receiving element 14,
The distance between the pixel elements 13, 14 is maintained.

In the reflected light type optically coupled semiconductor device of the above embodiment, the light emitting element section and the light receiving element section are sealed with the single transparent resin layer 15 as described above, but light transmission between the two elements is prevented. It is possible to operate normally because of this.

In manufacturing, first, the light emitting element 13 and the light receiving element 14 are bonded in the same manner as explained in FIG. 2. Therefore, problems like those in the conventional example shown in FIG. 5 do not occur, and the device can be made smaller. Further, since it is only necessary to carry out resin molding once to form the transparent resin layer 15 after that, as shown in FIGS.
This avoids problems such as an increase in the size of the envelope and a decrease in reliability due to poor adhesion between different resin layers, as in the conventional example shown in the figure. Furthermore, since the transparent resin 115 is formed by molding, there is no possibility that the surface of the transparent resin layer becomes concave and the directivity deteriorates as in the conventional examples shown in FIGS. 4 and 5.

FIG. 2 is a sectional view showing another embodiment of the present invention. In this embodiment, two convex lens sections 16 and 17 for a light emitting element section and a light receiving element section are formed on the surface of the transparent resin layer 15 to improve the directivity of the device.

FIG. 3 is a cross-sectional view showing yet another embodiment of the present invention, in which transparent fat adjustment is performed between the light emitting element section and the light receiving element section. A groove is formed from the surface of 15, and an opaque shield is embedded in the groove. With this, if the light emitting element 13 is on the transparent resin surface,
Even when light is reflected from the light receiving element 14, it is possible to prevent the reflected light from reaching the light receiving element 14 and causing malfunction.

Note that if a small amount of light is also emitted from the side surface of the light emitting element 13, it is preferable to provide a reflecting plate on the side of the light emitting element.

(Effects of the Invention) As detailed above, the reflective light type optically coupled semiconductor device according to the present invention can achieve miniaturization of the device, simplify the manufacturing process, and further improve reliability. , which has a remarkable effect.

[Brief explanation of drawings]

1 to 3 are cross-sectional views showing embodiments of the present invention, FIG. 4 is a perspective view showing an example of a conventional reflective light type optically coupled semiconductor device, and FIG. 6 to 8 are explanatory diagrams showing other examples of the conventional reflective light type optically coupled semiconductor device. 11.12... Header, 13... Semiconductor light emitting element,
14... Semiconductor light receiving element, 15... Transparent resin layer, 1
6゜17... Convex lens portion, 18... Shielding layer. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 2 Figure 6 Figure 117 Figure 8

Claims (1)

[Claims] A semiconductor light-emitting element and a semiconductor light-receiving element each die-bonded onto separate headers and connected to separate pads via bonding wires, and a single transparent element that integrally seals the light-emitting element part and the light-receiving element part. a resin layer, and leads extending from each of the header and the pad to the outside of the transparent resin layer, the semiconductor light emitting element emits light only from a limited area of its top surface; The shape of the transparent resin layer and the distance between the two elements are determined so that no light is emitted from the chip surface and the light reflected inside the resin layer from the surface of the transparent resin layer does not reach the semiconductor light receiving element. What is claimed is: 1. A reflective light type optically coupled semiconductor device, characterized in that: