JP3245494B2 - Manufacturing method of optical coupling device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing an optical coupling device.

[0002]

2. Description of the Related Art FIGS. 3A and 3B show a conventional optical coupling device. FIG. 3A is a front sectional view, and FIG. 3B is a perspective view from the upper side. c) is a right side sectional view.

[0003] As shown in FIG. 3, a conventional optical coupling device comprises:
For example, it is composed of a power semiconductor device, has a primary side lead frame 1 and a secondary side lead frame 2, and has a light emitting element chip 3 such as a light emitting diode chip mounted on the primary side lead frame 1; A light receiving element chip 4 such as a photo triac chip and a power control semiconductor element chip 5 such as a triac element chip and a thyristor element chip are mounted on a frame 2, and a desired frame-element is electrically connected by a wire. ing.

The primary side lead frame 1 and the secondary side lead frame 2 are arranged substantially in the same plane, and the light emitting element chip 3 and the light receiving element chip 4 are connected to each other as shown in FIG. The light-receiving element chip 4 is sealed with a light-transmitting resin made of, for example, silicone resin so as to be optically coupled, and the light-transmitting resin forms the optical waveguide 6. Here, the optical waveguide 6 has a cross section in the direction in which the two device chips 3 and 4 are juxtaposed in order that the light emitted from the light emitting device chip 3 can efficiently reach the light receiving device chip 4. It is formed in a visual dome shape.

Further, the outer periphery of the optical waveguide 6 and the power control semiconductor element 5 are sealed with a light reflecting resin 7,
The structure is such that only the external connection lead terminals are exposed. The light reflecting resin 7 needs to efficiently reflect light on the contact surface with the optical waveguide 6, and for example, a white epoxy resin containing titanium oxide is used.

In FIG. 3, reference numeral 8 denotes a holding member such as a polyimide tape. The holding member 8 is used for holding the light emitting element chip 3 and the light receiving element chip when potting the translucent resin. This is to prevent the translucent resin from flowing out of the gap between the lead frame and the lead frame.

[0007]

In the optical coupling device having the above-described structure, the optical waveguide 6 is formed of a translucent resin which forms a gel after curing. When the light reflecting resin 7 is sealed, the optical waveguide 6 does not have a uniform dome shape, the light transmission rate from the light emitting element chip 3 to the light receiving element chip 4 tends to change, and the sensitivity as an optical coupling device is not stable. That is, in the conventional optical waveguide 6, the holding member 8 is provided on the bottom surface of the sealing region made of the light-transmitting resin, the light-transmitting resin is potted on the holding material 8, and the side different from the bottom surface due to the surface tension of the bottom surface. Is formed so as to have a dome shape, for example, when applying a translucent resin, due to differences in the amount of resin applied, viscosity, etc.
This is because the shape of the dome is different. Also, when the light reflecting resin 7 is sealed, the optical waveguide 6 is deformed by the injection pressure of the resin. In particular, in power semiconductor devices, sensitivity stabilization was required.

[0008] Also, in terms of manufacturing, it is very difficult to form a uniform dome-shaped surface from the above, and the quality is not stable.

The present invention has been made in view of the above problems, and provides a method of manufacturing an optical coupling device in which a dome-shaped surface serving as a reflection surface of an optical waveguide can be formed stably and a light transmission rate between light receiving and emitting elements is stabilized. It is the purpose.

[0010]

SUMMARY OF THE INVENTION The manufacturing of the optical coupling device of the present invention is described .
The light emitting element chip that converts an electric signal into an optical signal and a light receiving element chip that converts an optical signal from the light emitting element chip into an electric signal are arranged on substantially the same plane, and the light emitting element chip and the light receiving element In a method of manufacturing an optical coupling device for resin-sealing to optically couple an element chip, a reflective member having a curved shape is disposed on both sides of the light-emitting element chip and the light-receiving element chip on a side facing the element chip. And the counter
The morphism member used as a saucer to the lower, forming an optical waveguide by sealing a translucent resin between the optical element chip and the reflecting member to seal them with light-shielding resin that It is characterized by the following.

A method of manufacturing the optical coupling device according to the first aspect.
In the method , the reflection member is formed of a lead frame.

Further, in the method for manufacturing an optical coupling device according to the first or second aspect, the reflection member is provided with a plating treatment on a side facing the light emitting / receiving element chip.

[0013]

According to the above construction, the method of manufacturing an optical coupling device according to the first aspect of the present invention is directed to a method of manufacturing the optical coupling device , the method comprising: A member is arranged , and the reflection member is
Use as dishes, an optical waveguide is formed by sealing a translucent resin between the optical element chip and the reflective member, these
Because sealing the at light-shielding resin, the surface tension with respect to the reflecting member of the light-transmitting resin, a surface that faces the optical element chip is formed an optical waveguide of the dome-shaped. Thus, the shape of the surface facing the light emitting and receiving element chip is determined by the processing accuracy of the reflection member, and the shape of the surface facing the light emitting and receiving element chip can be stabilized.

Also, a method of manufacturing the optical coupling device according to claim 1 is provided.
According to the method , since the reflection member is formed of a lead frame, processing of a curved shape is easy.

Further, in the method for manufacturing an optical coupling device according to claim 1 or 2, since the reflection member is plated on a side facing the light emitting / receiving element chip, the light emitting element chip is changed to the light receiving element chip. Light reflection efficiency can be improved.

[0016]

FIG. 1 is a view showing an optical coupling device according to an embodiment of the present invention. FIG. 1 (a) is a front sectional view, and FIG. 1 (b) is a perspective view from the upper surface side. FIG. 3C is a right side sectional view.

As shown in FIG. 1, the optical coupling device according to the present invention is composed of, for example, a power semiconductor device, has a primary lead frame 1 and a secondary lead frame 2 facing each other, and The lead frame 2 includes a plurality of mounting pieces arranged substantially in the same plane, and each of the plurality of mounting pieces has a light emitting element chip 3 such as a light emitting diode chip for converting an electric signal into an optical signal, A light receiving element chip 4 such as a photo triac chip for receiving an optical signal from the light emitting element chip 3 and converting it into an electric signal, and a power control semiconductor such as a triac element chip and a thyristor element chip connected to the light receiving element chip 4 The element chips 5 are individually mounted. In each of the element chips 3, 4, and 5, a desired frame-element chip is electrically connected by a wire.

The primary side lead frame 1 has a reflecting portion (reflecting member) 1a and a heat radiating portion 1b, and the reflecting portion 1a is arranged at a position above the light emitting element chip 3 and the light receiving element chip 4. , The light emitting and receiving element chips 3, 4
And the heat-radiating portion 1b is a heat-generating element chip, and the power control semiconductor element chip 5 is a heat-generating element chip.
And dissipates heat from the power control semiconductor element chip 5 to the outside via a light-shielding resin 9 described later. The reflector 1a has a curved shape at least in the direction in which the light emitting and receiving elements 3 and 4 are juxtaposed.

As shown in the drawing, a space between the light emitting element chip 3 and the light receiving element chip 4 and the reflecting portion 1a is made of, for example, a silicone resin so that the light emitting element chip 3 and the light receiving element chip 4 are optically coupled to each other. The optical waveguide 6 is formed by being sealed with a translucent resin. The optical waveguide 6 reflects the light emitted from the light emitting element chip 3 at the reflection portion 1a and receives the light at the light receiving element chip 4. Light transmission path.

Here, the reflection portion 1a of the optical waveguide 6
The surface (reflection surface) that comes into contact with the reflection portion 1a is in close contact with the reflection portion 1a, and is molded into a dome-shaped surface by the reflection portion 1a. This is due to the surface tension of the translucent resin with respect to the reflection portion 1a when the resin is sealed with the translucent resin.

With this configuration, the dome-shaped surface is uniquely determined by the processing system of the reflecting portion 1a, so that there is an inconvenience that the shape differs depending on the application amount and the viscosity of the translucent resin as in the prior art. In addition, since the dome-shaped surface is covered with the reflecting portion 1a, the shape is not lost when the resin is sealed with the light-shielding resin 9, so that the optical waveguide 6 having a stable shape can be obtained. Further, since the reflecting portion 1a is formed of a lead frame, processing can be easily performed.

Therefore, the light emitted from the light emitting element chip 3 can efficiently reach the light receiving element chip 4, the light transmission efficiency can be stabilized, and the sensitivity as the optical coupling device can be stabilized. Further, the radius of the dome-shaped surface (how it rises) can be easily changed by changing the shape of the reflecting portion 1a, and the setting of the reflection angle and / or the light transmission efficiency is easy. As a method of forming the optical waveguide 6, for example, the reflection portion 1a
In a state in which the light-receiving and light-emitting element chips 3 and 4 are arranged to face each other, the reflecting portion 1a is placed on the lower side and used as a tray, and a silicone resin is potted between the reflecting portion 1a and the light-emitting and receiving element chips 3 and 4. I do. Thus, the reflection part 1a
By using as a silicone resin pan,
The conventional holding member 8 (see FIG. 3) becomes unnecessary.

The outer periphery, that is, the portion other than the external connection lead terminals is sealed with a light-shielding resin 9 such as a black epoxy resin. The light-shielding resin 9
Since the resin contains a large amount of silica, the resin has high thermal conductivity and can efficiently transmit and radiate the heat generated by the power control semiconductor element 5.

In this embodiment, since the light is reflected by the reflecting portion 1a, it is not necessary to use a light-reflective resin as a light-shielding resin as in the prior art. The light-shielding resin is cheaper than the light-reflective resin, and is advantageous in cost.

In the optical coupling device having the above-described structure, the surface of the reflecting portion 1a on the side facing the light emitting element chip 3 and the light receiving element chip 4 is subjected to plating treatment, for example, gloss plating. The light reflection efficiency from the light receiving element 3 to the light receiving element chip 4 can be improved. In particular, the use of bright plating such as nickel plating and silver plating as the plating treatment is more effective than matte plating.

FIGS. 2A and 2B show another embodiment of the present invention. FIG. 2A is a front sectional view, and FIG. 2B is a perspective view from the top side. c) is a right side sectional view. This embodiment will be described only with respect to differences from the above embodiment.

As shown in FIG. 2, the optical coupling device of the present embodiment is a photocoupler, having a primary lead frame 1 and a secondary lead frame 2 facing each other, 2 includes a mounting piece for mounting a light-emitting element chip 3 such as a light-emitting diode chip and a mounting piece for mounting a light-receiving element chip 4 such as a photodiode chip. It is arranged to become. The primary side lead frame 1 is a reflecting member, and the light emitting element chip 3 and the light receiving element chip 4
And the light emitting and receiving element chips 3 and 4
Are formed to have a substantially curved shape in cross-section in which both element chip sides are concave.

Between the primary lead frame 1 and the light receiving / emitting element chips 3 and 4, a light transmitting resin made of, for example, a silicone resin is used so that the light emitting element chip 3 and the light receiving element chip 4 are optically coupled to each other. The optical waveguide 6 is formed by sealing the light receiving and emitting element chips 3 and 4 of the optical waveguide 6.
The surface (reverse slope) opposite to is formed by the primary side lead frame and formed in a dome shape in cross section. These have a structure in which portions other than the portions that become the lead terminals for external connection are sealed with a light-shielding resin 9 such as a black epoxy resin.

[0029]

As described above, according to the method for manufacturing an optical coupling device according to the first aspect of the present invention, the light-emitting element chip and the light-receiving element chip are curved with respect to the two element chips. A reflective member of a shape is arranged , and the reflective member is
To use as a pan, forming an optical waveguide by sealing a translucent resin between the between the reflective member optical element chip
And, since the seal them in light-shielding resin, the surface tension with respect to the reflection member of the translucent resin, optical element chip and the opposing surfaces are formed an optical waveguide of the dome-shaped. Thus, the shape of the optical element chip and the surface facing is determined by the processing system of the reflecting member, receiving the shape of the light-emitting element chip and the opposing surfaces is stable, to stabilize the light transmissibility, the optical coupling equipment As the sensitivity becomes stable.

Further, a method of manufacturing the optical coupling device according to claim 2 is provided.
According to the method , since the reflection member is formed of a lead frame, processing of a curved shape is easy.

Further, the manufacturing of the optical coupling device according to claim 3 is performed.
According to the method , since the reflection member is formed by plating on the side facing the light receiving / emitting element chip, the light reflection efficiency from the light emitting element chip to the light receiving element chip is improved.

[Brief description of the drawings]

FIG. 1 is a view showing an optical coupling device according to an embodiment of the present invention, wherein FIG. 1 (a) is a front sectional view, and FIG. 1 (b) is a perspective view from the top side, and FIG. (C) is a right side sectional view.

2A and 2B are diagrams showing another embodiment of the present invention, wherein FIG. 2A is a front sectional view, FIG. 2B is a perspective view from the top side, and FIG. It is a right side view sectional view.

FIG. 3 is a view showing a conventional optical coupling device, and FIG.
FIG. 1B is a front sectional view, FIG. 1B is a perspective view from the top side, and FIG. 1C is a right side sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Primary-side lead frame 1a Reflection member (reflection part) 2 Secondary-side lead frame 3 Light emitting element chip 4 Light receiving element chip 6 Translucent resin 9 Light shielding resin

Claims (3)

(57) [Claims] A light-emitting element chip for converting an electric signal into an optical signal; and a light-receiving element chip for converting an optical signal from the light-emitting element chip into an electric signal. In a method of manufacturing an optical coupling device for resin-sealing to optically couple a light receiving element chip, a reflective member having a curved shape with respect to the both light emitting element chips and the light receiving element chips is provided on a side facing the light emitting element chips and the light receiving element chips. Arrangement
The reflecting member is placed on the lower side and used as a tray, and a translucent resin is sealed between the reflecting member and the light emitting / receiving element chip.
And forming an optical waveguide, the be sealed these on a light-shielding resin
The method of manufacturing an optical coupling device, characterized in that that. 2. The method of manufacturing an optical coupling device according to claim 1, wherein said reflection member is made of a lead frame.
Law . 3. The method for manufacturing an optical coupling device according to claim 1, wherein the reflection member is plated on a side facing the light emitting / receiving element chip.