JPH0738143A - Optical coupling device - Google Patents

Abstract

(57) [Abstract] [Purpose] To prevent malfunction of the optical coupling device due to ambient light. A light emitting element 2 and a light receiving element 3 are arranged so as to be optically coupled to each other, and the light emitting element 2 and the light receiving element 3 are respectively formed on the upper surface of an insulating film. In the optical coupling device mounted on the optical film 10, an opening 12 is provided in at least a mounting portion of each of the light emitting element 2 and the light receiving element 3 in the insulating film 1, and the light emitting element 2 and the light receiving element 3 are respectively opened. The light-transmitting conductor pattern 9 and the light-receiving conductor pattern 10 which are overhung in the hole 12 are mounted, and a light-transmitting substance 13 is provided between the light-emitting element 2 and the light-receiving element 3. It is characterized in that the light emitting element 2 and the light receiving element 3 are sealed with a light shielding resin 4.

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 for transmitting input / output by light.

[0002]

2. Description of the Related Art In recent years, the market demand for optical coupling devices (photocouplers) has been remarkably high, and in particular, the penetration rate of dual in-line package (DIP) type optical coupling devices which are double-molded with a light-transmitting resin and a light-shielding resin is increasing. However, as electronic components have become smaller and thinner, the demand for surface mount (SMD) types has also increased, and small SMD types have been developed and are becoming popular.

However, the demand for the above-mentioned miniaturization and thinning has been further advanced. However, since it has a lead frame, it is necessary to secure a certain size in consideration of its strength and the like, and miniaturization of the SMD type optical coupling device has reached the limit.

In response to this trend, leadless couplers are also under development, and a film carrier type package which is further thinned is desired.

As one of the structures of the optical coupling device adopting the film carrier method, as shown in FIG. 8, an infrared light emitting diode which is a light emitting element is provided on the same plane of a transparent insulating film 1 (tape carrier). 2 and a phototransistor 3, which is a light receiving element, are mounted respectively.

Since the light emitting element 2 has an upper electrode (anode or cathode) and a back surface electrode (cathode or anode), it is laid out in a direction vertical to the film carrier in surface mounting, and both electrodes are electromechanical with Ag paste or the like. Make a connection. The light-receiving element 3 is surface-bonded to a chip that has undergone bump processing (not shown). This bump has
Au or solder is used.

For the tape material of the insulating film 1, a resin material such as polyimide, polyester, glass epoxy is used. A copper foil or rolled copper of a conductor pattern formed on the insulating film 1 is used to punch a tape, which is then laminated and patterned by etching.

After mounting the light emitting element 2 and the light receiving element 3, molding is performed with a light-blocking molding resin 4. The mold resin 4 is a granular material (E pellet) made of epoxy resin used in the assembly process of an integrated circuit (IC), and is melted by heat to be molded. Alternatively, there is also a method of molding using a transfer molding technique in order to improve dimensional accuracy in a thin type.

[0009]

In the optical coupling device of the film carrier type, the insulating film 1 corresponding to the optical path path (hereinafter referred to as the optical path) of the light emitting element 2 and the light receiving element 3 is made of polyimide resin or the like as described above. Because
The infrared light emitting diode has a transmittance of about 90% with respect to a peak wavelength of around 950 μm, which enables a design with good light efficiency. However, since a copper foil or the like is used for the signal extracting electrode and a part of the insulating film 1 is integrated as a reinforcing material, the disturbance light 5 is received from the light receiving element 3 from the thickness direction of the end of the insulating film 1 or the like. And may cause the device to malfunction.

Therefore, the applicant of the present invention has filed Japanese Patent Application No. 3-31250.
There is an optical coupling device proposed in No. 1 (filed on November 27, 1991).

The optical coupling device is as shown in FIGS. 9 and 10.
A slit 6 is formed in the outer peripheral portion of the insulating film 1 to prevent ambient light from traveling in the thickness direction of the insulating film 1 and entering the optical path between light reception and emission. The slit 6
In the figure, the periphery of the optical path forming area La of the insulating film 1 is punched out. However, after the slit 6 is formed, both regions La and Lb are connected by the connecting portion 7 so that the optical path forming region La of the insulating film 1 is not separated from the other region Lb of the insulating film 1 and is not separated. There is. It should be noted that by providing the connecting portion 7, ambient light may enter from the connecting portion 7 into the optical path forming region La. Therefore, a notch 8 is also formed on the outer side of the connecting portion 7 to prevent light traveling straight from the outside from passing through the connecting portion 7 and entering the optical path forming region La.

In the figure, 2 is a light emitting element, 3 is a light receiving element, 4 is a light shielding resin, 9 is a light emitting side conductor pattern, 10 is a light receiving side conductor pattern, 11
Is a reflective film.

According to the above-mentioned conventional example, as shown in FIG. 11, it is possible to prevent the straight traveling light from the outside from directly entering the optical path forming region La. However, in the non-optical path forming region Lb and the connecting portion 7, the straight traveling light is reflected by the light shielding resin 4 or the like.
By repeating the absorption, ambient light may slightly enter the optical path forming region La, which may cause a malfunction of the device.

In view of the above problems, it is an object of the present invention to provide an optical coupling device capable of preventing malfunction of the device due to ambient light.

[0015]

The optical coupling device of the present invention comprises:
An optical coupling device in which a light emitting element and a light receiving element are arranged so as to be optically coupled, and the light emitting element and the light receiving element are mounted on a light emitting side conductor pattern and a light receiving side conductor pattern formed on the upper surface of an insulating film, respectively. In the insulating film, an opening is provided in at least a mounting portion of each of the light emitting element and the light receiving element, and the light emitting element and the light receiving element respectively overhang the light emitting side conductor pattern and the light receiving side. It is mounted on a side conductor pattern, is provided with a light transmissive substance between the light emitting element and the light receiving element, and seals the light transmissive substance, the light emitting element and the light receiving element with a light shielding resin. Is.

[0016]

According to the above structure, in the optical coupling device of the present invention, the light-transmitting substance is used as the optical path, and the light-emitting element and the light-receiving element are completely light-shielding resin except for the portions facing the light-transmitting substance. Since it is sealed with, even if disturbance light enters from the thickness direction of the insulating film, it is possible to prevent the light emitting element from being irradiated by the disturbance light when not operating and being in the same state as emitting light, Further, the light receiving element does not receive ambient light. Therefore, malfunction of the device due to ambient light can be prevented.

[0017]

1 is a block diagram of an optical coupling device showing an embodiment of the present invention. FIG. 1 (a) is a horizontal sectional view and FIG. 1 (b) is a vertical sectional view. FIG. 2 is a plan view showing the insulating film before processing, FIG. 3 is a plan view showing a state in which openings are formed in the insulating film, and FIG. 4 shows a state in which a conductor pattern is formed on the insulating film. FIG. 5 is a plan view, FIG. 5 is an enlarged cross-sectional view of part A of FIG. 4, FIG. 6 is a plan view showing a state in which a light emitting / receiving element and a light transmissive substance are mounted on an insulating film, and FIG. 7 is an insulating film. FIG. 4 is a plan view showing a state in which the light emitting / receiving element and the light transmissive substance are sealed with a light shielding resin.

As shown in FIG. 1, in the optical coupling device of this embodiment, a light emitting side conductor pattern 9 and a light receiving side conductor pattern 10 are formed on the upper surface of an insulating film 1, and the light emitting side conductor pattern 9 and the light receiving side conductor pattern 10 are formed. A light-emitting element 2 and a light-receiving element 3, respectively, and an opening 12 is provided in the insulating film 1 in the entire mounting area of the light-receiving and light-emitting elements 2 and 3 and in the vicinity thereof. The element 2 and the light-receiving element 3 are respectively provided with the opening 12
Mounted on the light-emitting side conductor pattern 9 and the light-receiving side conductor pattern 10 which are overhanged with each other. Transparent material 13
And the light transmitting material 13, the light emitting element 2 and the light receiving element 3 are sealed with a light shielding resin 4. still,
In the figure, 8 is a notch.

As shown in FIG. 2, the insulating film 1 is made of a polyimide resin which is transparent and has excellent heat resistance, and a plurality of devices for devices are provided in a manufacturing process in a band-like manner. On the lower surface of the insulating film 1, there is formed a reflective film 11 that reflects light obliquely downward from the side of the light emitting element 2 to the light receiving element 3. The reflection film 11 is made of copper foil, which is the same material as the conductor patterns 9 and 10, and is arranged at least in the entire optical path between the light emitting / receiving elements 2 and 3, as shown in FIG.

Each of the openings 12 has a size equal to or larger than that of the light emitting / receiving elements 2 and 3, and resin is injected when the light shielding resin 4 is sealed.

An infrared light emitting diode or the like is used as the light emitting element 2, and a phototransistor or the like is used as the light receiving element 3.

As shown in FIG. 4, the light emitting side conductor pattern 9 and the light receiving side conductor pattern 10 are respectively formed on the upper surface of the insulating film 1 based on a desired circuit design using a conductive material such as copper foil. ing. The both conductor patterns 9,
The tip portion of 10 is formed in a substantially L shape so as to be connected to each electrode of each element 2 and 3, and the tip thereof is as shown in FIG.
An overhang is formed so as to project into the opening 12 of the insulating film 1 so that the respective elements 2 and 3 can be mounted.

The light transmissive substance 13 may be of any material as long as it has a high transmittance and an insulating property, and may have any shape as long as the light emitting and receiving elements 2 and 3 are optically coupled.
As an example of using glass, borosilicate glass or the like is used.

As the light-shielding resin 4, a general black epoxy resin having a light absorbing property is used, and as shown in FIG.
It is poured into the upper surface of the insulating film 1 and the openings 12 and cured to prevent ambient light from reaching the light emitting / receiving elements 2 and 3.

Here, as shown in FIG. 1, the disturbance light 5 may enter from the thickness direction of the insulating film 1. However, according to the optical coupling device having the above configuration, the light emitting / receiving elements 2, 3
A light-transmitting substance 13 is provided between them to form an optical path, and each of the light-receiving and emitting elements 2 and 3 is covered with the light-shielding resin 4 except a portion adjacent to the light-transmitting substance 13, so that the ambient light 5 Is not affected by. That is, when the light emitting element 2 is not operating, it is possible to prevent the light emitting element 2 from being irradiated with the ambient light 5 and emitting light. Further, since the light receiving element 3 receives only the light from the direction of the light transmissive substance 13, it hardly receives the ambient light 5. Therefore, malfunction of the device due to ambient light can be prevented.

A method of manufacturing the optical coupling device having the above structure will be described.

First, as shown in FIG. 2, the insulating film 1 in the form of a film carrier tape is punched out by the punching die to form the openings 12 and the notches 8 to obtain the shape shown in FIG. In the figure, reference numeral 15 is a blank for sealing the outer periphery of the insulating film 1, and 16 is a resin sealing region.

After that, a copper foil is uniformly laminated on the insulating film 1, and then the necessary copper foil is left by etching as shown in FIG.

Thereafter, the copper foil is plated with solder. This is because the solder bumps are formed on the light-receiving element 3 to be surface-mounted, so that the solder and the solder are electrically and mechanically connected to each other.

Insulating film 1 produced in this way
Then, as shown in FIG. 6, the infrared light emitting diode chip which is the light emitting element 2 is die-bonded. The light emitting element 2 has electrodes on the upper surface and the back surface, and is placed on the insulating film 1 in a state in which the electrodes are perpendicular to the electrodes and electrically connected with the Ag paste 14, and the high temperature is applied to cure the Ag paste 14. Leave it alone.

Next, face-down bonding is performed on the phototransistor chip which is the light receiving element 3. The electrodes of the light receiving element 3 are solder bump processed,
Heat is applied from the back side of the insulating film 1 with a heater head,
Connect the solders together.

Next, an insulating film which is a light transmitting substance 13 is mounted on the insulating film 1 adjacent to the light receiving and emitting elements 2 and 3 by using a transparent resin or the like.

The order of mounting the light emitting element 2, the light receiving element 3, and the light transmissive substance may be different from the above order.

After the light emitting element 2 and the light receiving element 3 are assembled on the insulating film 1 in this way, resin molding is performed using the light shielding resin 4. Here, the light-shielding resin 4
Will perform transfer molding to improve the dimensional accuracy for the purpose of thinning. The shape after this molding is shown in FIG.

Thereafter, the optical coupling device continuous in the form of a tape is punched out as a single product to complete the final product. This state is shown in FIG.

Further, in the above-mentioned embodiment, the disturbance light is reflected and absorbed repeatedly and travels on the insulating film 1 with a very small amount, and this light goes up to the light transmissive substance 13 to emit light from the light emitting element 2 and the light receiving element 3. Although it is considered that there is a risk of reaching the light-transmitting substance 13, by providing an insulating light-reflecting film on the back surface of the light-transmitting substance 13, the light-emitting element 2, the light-receiving element 3, and the light-transmitting substance 13 are not reached. , Can completely prevent the entry of ambient light. At this time, the reflective film 11 on the back surface of the insulating film 1 is unnecessary.

The present invention is not limited to the above embodiments, and it goes without saying that many modifications and changes can be made to the above embodiments within the scope of the present invention.

For example, when a gap is formed between the light emitting element 2 or the light receiving element 3 and the light transmissive substance 13, the gap is filled with a transparent resin or the like.

[0039]

As described above, according to the optical coupling device of the present invention, the light-transmitting substance is used as the optical path, and the light-emitting element and the light-receiving element are shielded except for the portions facing the light-transmitting substance. Since it is sealed with resin, ambient light can be prevented from reaching the light emitting element and the light receiving element, and malfunction of the optical coupling device can be prevented.

[Brief description of drawings]

1A and 1B are configuration diagrams showing an embodiment of the present invention, in which FIG. 1A is a horizontal sectional view and FIG. 1B is a vertical sectional view.

FIG. 2 is a plan view showing an insulating film before processing.

FIG. 3 is a plan view showing a state in which openings are formed in an insulating film.

FIG. 4 is a plan view showing a state in which a conductor pattern is formed on an insulating film.

5 is an enlarged cross-sectional view of a portion A of FIG.

FIG. 6 is a plan view showing a state in which a light emitting / receiving element and a light transmissive material are mounted on an insulating film.

FIG. 7 is a plan view showing a state in which a light emitting / receiving element and a light transmissive substance on an insulating film are sealed with a light shielding resin.

FIG. 8 is a vertical sectional view showing a conventional example.

FIG. 9 is a vertical cross-sectional view showing another conventional example.

10 is a plan view of the optical coupling device shown in FIG.

11 is a cross-sectional view of the optical coupling device shown in FIG.

[Explanation of symbols]

 1 Insulating Film 2 Light-Emitting Element 3 Light-Receiving Element 4 Light-Shielding Resin 9 Light-Emitting Side Conductor Pattern 10 Light-Receiving Side Conductor Pattern 12 Open Hole (Part) 13 Light-Transmissive Material

Claims (1)

[Claims] 1. A light emitting element and a light receiving element are arranged so as to be optically coupled to each other, and the light emitting element and the light receiving element are mounted on a light emitting side conductor pattern and a light receiving side conductor pattern formed on an upper surface of an insulating film, respectively. In the optical coupling device configured as described above, an opening is provided in at least a mounting portion of each of the light emitting element and the light receiving element in the insulating film, and each of the light emitting element and the light receiving element overhangs in the opening portion. Mounted on the side conductor pattern and the light-receiving side conductor pattern, providing a light-transmitting substance between the light-emitting element and the light-receiving element, the light-transmitting substance,
An optical coupling device characterized in that a light emitting element and a light receiving element are sealed with a light blocking resin.