JPH07335932A - Optical device - Google Patents

Abstract

PURPOSE:To provide an optical device which facilitates the suppression of the penetration of an unnecessary light and the suppression of a photocurrent. CONSTITUTION:An electric signal processing part 3 is adjacent to a photoelectric conversion part 2 having a photodetector and a light emitting device to compose an optical device 1. A side light shielding films 15 which shields a light toward a circuit region from the side are provided on the side circumference of wiring region of the electric signal processing part 3. Further, an upper light shielding film 14 and the side light shielding films 15 may be made of conductive material and may be also used as wirings in the wiring region, the side light shielding film 15 and the upper light shielding film 14 may be formed in one-piece or the side light shielding film 15 may be made of conductive material and connected to the power supply potential or the ground potential of the circuit in the circuit region.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical device in which a photoelectric conversion section and an electric signal processing section are arranged adjacent to each other.

[0002]

2. Description of the Related Art In a light receiving device of an infrared remote controller, a light receiving element for receiving an infrared signal and converting it into a predetermined electric signal, and an electric signal processing section for processing the electric signal converted by the light receiving element. And these are formed on the same substrate, for example, to form one light receiving module.

Further, the light emitting device as a commander is provided with an electric signal processing section for generating an electric signal according to a command, and a light emitting element for outputting a predetermined infrared signal based on the generated electric signal, These are arranged adjacent to each other into one package.

In recent years, from the viewpoint of miniaturizing an optical device including a light receiving device and a light emitting device, a photoelectric conversion unit including a light receiving element section and a light emitting element section and an electric signal processing section are formed on the same substrate. Resin sealing is considered.
5A and 5B are diagrams illustrating an example of a conventional optical device, FIG. 5A is a plan view, and FIG. 5B is an enlarged cross-sectional view of a D portion of FIG.

That is, the optical device 1 includes a photoelectric conversion unit 2
And the electric signal processing section 3 are formed adjacent to each other on the same substrate 10, and are integrally sealed with a transparent resin (not shown). The electrical signal processing unit 3 includes a wiring layer 12 including an epitaxial layer 11 formed on the substrate 10 to form a predetermined circuit region, and a first layer wiring 12a and a second layer wiring 12b provided on the epitaxial layer 11. It has and.

Since the electric signal processing section 3 is arranged adjacent to the photoelectric conversion section 2, it is sealed with the same translucent resin (not shown) as the sealing material of the photoelectric conversion section 2. There is. Therefore, there is a possibility that unnecessary light may enter the circuit region to cause a malfunction, and the upper light-shielding film 14 is provided on the circuit region to prevent this. The upper light-shielding film 14 also serves as the second-layer wiring 12b, for example, and is provided in a state of covering almost the entire area above the circuit region.

[0007]

However, such an optical device has the following problems. That is, as shown in FIG. 5B, since the upper light-shielding film 14 that also serves as the second-layer wiring 12b is provided above the epitaxial layer 11 that is the circuit region, light from above does not interfere with the upper light-shielding film. Shut off at 14. However, the light from the side is made of a highly transparent insulating layer 13 such as a silicon oxide film or a silicon nitride film.
And reaches the internal circuit area (Fig. 5
(See arrow in (b)).

That is, in the case of the light receiving device, unnecessary external light enters from the side, and in the light emitting device, the light emitted by itself enters and enters from the side, and the photocurrent based on the entering light enters the circuit area. Will begin to flow. This photocurrent causes a malfunction in processing an electric signal.
Conventionally, in order to counteract this photocurrent, the current value flowing in the circuit region is set to a high value to suppress the influence of the photocurrent, but this increases the current consumption and the required capacitance. This increases the size of the optical device, resulting in an increase in the area of the entire optical device.

[0009]

SUMMARY OF THE INVENTION The present invention is an optical device made to solve such problems. That is, the optical device of the present invention has a circuit area provided on the substrate,
An electrical signal processing unit configured of an upper light-shielding film that blocks light traveling toward the wiring region and the circuit region provided on the circuit region, and a photoelectric conversion unit disposed adjacent to the electrical signal processing unit are provided, A side light-shielding film for blocking light traveling from the side of the wiring region to the circuit region is provided around the side of the wiring region.

Further, in the optical device of the present invention, the upper light-shielding film and the side light-shielding film are made of a conductive material and are also used as the wiring provided in the wiring region. Further, it is also an optical device in which the side light-shielding film is provided integrally with the upper light-shielding film, or the side-light shielding film is made of a conductive material so as to have a power supply potential or a ground potential with respect to the circuit in the circuit region.

Further, it is also an optical device in which the photoelectric conversion section is provided with a light receiving element for converting the received light into a predetermined electric signal or a light emitting element for emitting the light based on the predetermined electric signal.

[0012]

According to the present invention, the upper light-shielding film can block light from entering into the inside from above the circuit region, and the side-light-shielding film provided around the side of the wiring region can prevent light from entering into the inside from the side. You will be able to shut off even. Therefore, photocurrent does not flow because unnecessary light does not enter the circuit area, and malfunction of the circuit is eliminated. Moreover, the current value of the circuit can be reduced accordingly.

Further, since the upper light-shielding film and the side light-shielding film are made of a conductive material and also serve as the wiring in the wiring region, each light-shielding film can be manufactured in the same step as the wiring. Furthermore, by integrating the side light shielding film with the upper light shielding film, both light shielding films can be manufactured in the same process.

Further, by setting the side light shielding film made of a conductive material to the power supply potential or the ground potential for the circuit in the circuit region, it becomes possible to shield the circuit region as well as electromagnetically shield it.

[0015]

Embodiments of the optical device of the present invention will be described below with reference to the drawings. 1A and 1B are views for explaining an optical device of the present invention, FIG. 1A is a plan view, and FIG. 1B is an enlarged sectional view of a portion A of FIG. Further, FIG. 2 is a schematic cross-sectional view for explaining an application example of the present invention, in which (a) shows a light receiving device and (b) shows a light emitting device. As shown in FIG. 1A, this optical device 1
Mainly, the photoelectric conversion unit 2 and the electric signal processing unit 3 are arranged adjacent to each other on the same substrate 10 (see FIG. 1B),
It is integrally sealed with a transparent resin (not shown).

The optical device 1 may have a monolithic structure in which the photoelectric conversion section 2 and the electric signal processing section 3 are provided on the same material substrate such as silicon, but the photoelectric conversion section 2 is formed in a chip shape. Also, the electric signal processing unit 3 may be arranged on the same substrate for mounting in a multi-chip form.

For example, when the optical device 1 is applied to a light receiving device as shown in FIG. 2A, a pn in which an n-type epitaxial layer is formed on a p-type silicon substrate as a photoelectric conversion part 2 including a light receiving element is used. A photodiode is formed by bonding, and the electric signal processing unit 3 (FIG. 1A) is formed on the same material substrate.
). This is sealed with a package 5 made of a translucent resin, and light is condensed through an integrated lens 51.

When the optical device 1 is applied to a light emitting device as shown in FIG. 2B, a light emitting diode having a pn junction, for example, is used as the photoelectric conversion portion 2 including a light emitting element to mount a substrate. The electric signal processing unit 3 for mounting the light emitting diode on the same substrate 10a is mounted on the same substrate 10a. Then, these are integrally sealed with a package 5 made of a translucent resin to form a light emitting device.

As shown in FIG. 1 (b), the electrical signal processing section 3 of the optical device 1 of any of the embodiments has the substrate 1
A predetermined circuit region is formed by the epitaxial layer 11 formed on the upper surface of the substrate 0, and a wiring layer 12 including a first wiring layer 12a and a second wiring layer 12b formed of aluminum or the like is provided above the wiring layer 12 via an insulating layer 13. There is.

The second layer wiring 12b of the wiring layer 12 of the optical device 1 also serves as the upper light-shielding film 14, and the side light-shielding film formed of aluminum or the like is provided around the outer periphery of the wiring layer 12. 15 are provided. The side light-shielding film 15 is formed in the same step as the upper light-shielding film 14 which is, for example, the second layer wiring 12b, and surrounds the side end portion of the insulating layer 13. This makes it possible to block light from the side of the optical device 1 and prevent photocurrent from flowing to the internal circuit.

When the upper light-shielding film 14 is used as the power supply potential for the circuit in the circuit area, the side light-shielding film 15 is formed with a slight gap between the upper light-shielding film 14 and the side light-shielding film 14. 15 may be the ground potential. This allows
Compared to the case where only the upper light-shielding film 14 is formed, the electromagnetic shield effect on the circuit area can be enhanced.

Furthermore, in the optical device 1 of the present invention, the upper light-shielding film 14 and the side light-shielding film 15 can block the external light from above and from the side and suppress the photocurrent flowing in the circuit in the circuit region. It becomes unnecessary to flow a large current as a current value of the circuit that can oppose the photocurrent. As a result, the current value of the circuit can be lowered and the current consumption can be reduced.

Next, another example of the present invention will be described with reference to FIGS. 3A and 3B are diagrams illustrating another example (No. 1), FIG. 3A is a plan view, and FIG. 3B is an enlarged cross-sectional view of a B portion of FIG. That is, the optical device 1 includes the photoelectric conversion unit 2
And the electric signal processing unit 3 are formed adjacent to each other on the same substrate 10, which is similar to the optical device 1 shown in FIG.
The difference is that the upper light-shielding film 14 and the side light-shielding film 15 are integrated.

The wiring layer 12 of the electric signal processor 3 is composed of, for example, a first layer wiring 12a and a second layer wiring 12b,
The second-layer wiring 12b also serves as the upper light-shielding film 14 and the side light-shielding film 15. That is, the second layer wiring 12b
And the upper light-shielding film 14 and the side light-shielding film 15 are integrally formed. As a result, the second layer wiring 12b,
The upper light-shielding film 14 and the side light-shielding film 15 can be formed in the same process.

In this optical device 1, the upper light-shielding film 14 can block light from above the optical device 1, and the side light-shielding film 15 can block light from the side. As a result, the photocurrent flowing in the circuit in the circuit region can be suppressed, and the malfunction of the electric signal processing unit 3 can be prevented.

Further, the upper light-shielding film 14 and the side light-shielding film 15 are integrally formed of a conductive material such as aluminum, and are set as a power supply potential or a ground potential for the circuit to have an electromagnetic shield effect on the circuit area. The optical device 1 can also be made to have a strong resistance against disturbance.

FIGS. 4A and 4B are views for explaining another example (No. 2) of the present invention. FIG. 4A is a plan view and FIG. 4B is an enlarged sectional view of a C portion of FIG. In this optical device 1, the photoelectric conversion unit 2 and the electric signal processing unit 3 are formed adjacent to each other on the same substrate 10, and the upper light shielding film 14 and the side light shielding film 15 are integrated. Is similar to the optical device 1 shown in FIG.
The difference is that a side light-shielding film 15 'is provided.

That is, the wiring layer 12 of the electric signal processing section 3
Among them, the second-layer wiring 12b also serves as the upper light-shielding film 14 and the side light-shielding film 15, and is formed in the same step. The side light-shielding film 15 'is formed in the same step as the first layer wiring 12a,
The side light-shielding film 15 and the epitaxial layer 11 are arranged so as to shield light.

That is, the two side light-shielding films 15 and 1
By 5 ', it becomes possible to completely prevent the light from the side of the optical device 1 (especially the light from the right side in the figure) from directly entering the inside, and to significantly suppress the photocurrent. Is possible. Further, the side light-shielding film 15 is set to the power supply potential for the circuit, and the side light-shielding film 15 ′ is set to the ground potential, so that it is possible to provide the electromagnetic shielding effect to the circuit region.

In any of the examples described in this embodiment, the upper light-shielding film 14 and the side light-shielding film 15 may be provided independently without being used also as the second-layer wiring 12b. Further, as the upper light-shielding film 14 and the side light-shielding films 15 and 15 ′, other than aluminum, a material capable of blocking predetermined light,
Moreover, anything that can be applied to the insulating layer 13 can be applied.

Further, in the present embodiment, the case where the photoelectric conversion portion 2 is provided with the light receiving element and the case where the light emitting element is provided as the optical device 1 are shown as an example, but the photoelectric conversion portion 2 is provided with the light receiving element and the light emission. A light emitting and receiving device including both elements (for example,
The same applies to the case of a remote commander capable of bidirectional communication).

[0032]

As described above, the optical device of the present invention has the following effects. That is, in the optical device of the present invention, since the upper light blocking film that blocks light from above and the side light blocking film that blocks light from the side are provided, unnecessary light does not enter the electrical signal processing unit. Therefore, it is possible to suppress malfunction of the circuit due to photocurrent.

Furthermore, since the generation of photocurrent can be suppressed, it is not necessary to increase the value of the current flowing in the circuit to counter it.
It is possible to reduce the current consumption. Along with this, the circuit configuration can be miniaturized and the optical device can be downsized. Further, by setting the side light-shielding film to a power supply potential or a ground potential for the circuit, an electromagnetic shield effect can be provided, and the operation reliability of the optical device can be further improved.

[Brief description of drawings]

1A and 1B are diagrams illustrating an optical device of the present invention, FIG. 1A is a plan view, and FIG. 1B is an enlarged cross-sectional view of a portion A of FIG.

FIG. 2 is a schematic cross-sectional view illustrating an application example of the optical device of the present invention, in which (a) is a light receiving device and (b) is a light emitting device.

3A and 3B are diagrams illustrating another example (No. 1), FIG. 3A is a plan view, and FIG. 3B is an enlarged cross-sectional view of a B part in FIG. 3A.

4A and 4B are views for explaining another example (No. 2), in which (a) is a plan view and (b) is an enlarged cross-sectional view of a C portion of (a).

FIG. 5 is a diagram illustrating a conventional example, (a) is a plan view,
(B) is an enlarged cross-sectional view of the D portion of (a).

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Optical device 2 Photoelectric conversion part 3 Electric signal processing part 10 Substrate 11 Epitaxial layer 12 Wiring part 12a First layer wiring 12b Second layer wiring 13 Insulating layer 14 Upper light-shielding film 15 Side light-shielding film

Claims (6)

[Claims] 1. An electric signal processing section comprising a circuit area provided on a substrate, a wiring area provided on the circuit area, and an upper light-shielding film for blocking light traveling to the circuit area,
An optical device comprising a photoelectric conversion unit arranged adjacent to the electrical signal processing unit, for blocking light traveling from the side of the wiring region to the circuit region around the side of the wiring region. An optical device, characterized in that a side light-shielding film is provided. 2. The optical device according to claim 1, wherein the upper light-shielding film and the side light-shielding film are made of a conductive material and also serve as a wiring provided in the wiring region. 3. The optical device according to claim 1, wherein the side light shielding film is provided integrally with the upper light shielding film. 4. The side light-shielding film is made of a conductive material,
The optical device according to claim 1, wherein the optical device has a power supply potential or a ground potential with respect to a circuit in the circuit region. 5. The optical device according to claim 1, wherein the photoelectric conversion unit includes a light receiving element that converts received light into a predetermined electric signal. apparatus. 6. The optical device according to claim 1, wherein the photoelectric conversion unit includes a light emitting element that emits light based on a predetermined electric signal. .