JP2021125539A - Optical device - Google Patents

Abstract

To obtain an optical device which, for example, is formed at a lower cost and can secure required temperature control performance.SOLUTION: An optical device includes, for example, a temperature control device which has a first surface oriented in a first direction and a second surface oriented in a direction opposite to the first direction at the opposite side of the first surface and in which one of the first surface and the second surface serves as a heat absorption surface and the other surface serves as a heat radiation surface; an optical component provided on the first surface; and a cover which is located on the first surface, covers the optical component, and is made of a light transmissive synthetic resin material which transmits light received or sent by the optical component.SELECTED DRAWING: Figure 1

Description

The present invention relates to an optical device.

Conventionally, an optical device in which an optical component is housed in a housing is known (Patent Document 1 and Patent Document 2). In Patent Document 1, the housing is made of a metal material, and in Patent Document 2, the housing is made of ceramic. In Patent Document 1, a temperature control device is housed in the housing as well as an optical component.

In an optical device including a housing made of a metal material or ceramic as in Patent Document 1 and Patent Document 2, for example, there is a problem that the manufacturing cost of the housing is high, and the manufacturing cost and price of the optical device are high. was there.

On the other hand, an optical device in which an optical component is covered with a synthetic resin material is known (Patent Document 3). In this case, the manufacturing cost and price of the optical device can be lower than when the housing is made of metal material or ceramic.

JP-A-2002-111115 Japanese Unexamined Patent Publication No. 4-167583 Japanese Unexamined Patent Publication No. 2004-319555

However, as in Patent Document 1, when the optical device is provided with a temperature control device, if the temperature control device is entirely covered with a synthetic resin material, it is synthesized between a high temperature portion and a low temperature portion of the temperature control device. Since heat is transferred through the resin material, the temperature difference between the high temperature portion and the low temperature portion becomes small, and there is a possibility that the required temperature adjustment function cannot be obtained.

Therefore, one of the problems of the present invention is, for example, to obtain an optical device that can be configured at a lower cost and can secure the required temperature control performance.

The optical device of the present invention has, for example, a first surface facing the first direction and a second surface facing the opposite direction of the first direction on the opposite side of the first surface. A temperature control device in which one surface of the surface and the second surface serves as an endothermic surface and the other surface serves as a heat radiating surface, optical components provided on the first surface, and the above-mentioned located on the first surface. It includes a cover made of a light-transmitting synthetic resin material that covers an optical component and transmits light received or transmitted by the optical component.

Further, in the optical device, for example, the temperature control device includes a first substrate having the first surface, a second substrate having the second surface, and the first substrate and the second substrate. It has a thermoelectric element located between them, and the cover is in contact with only the first substrate of the first substrate, the second substrate, and the thermoelectric element.

Further, in the optical device, for example, the cover partially covers the first surface.

Further, in the optical component, the optical component includes a photoelectric component that can be electrically driven, and a portion of the first surface that is detached from the cover is electrically connected to the photoelectric component and the cover. A conductor exposed from the optics is provided.

The optical device also includes, for example, a temperature sensor covered with the cover.

Further, in the optical device, for example, the outer surface of the cover is covered with a coating film of an inorganic material.

Further, in the optical device, for example, the coating film is a metal film.

Further, in the optical device, for example, the synthetic resin material is any one of an epoxy resin, an acrylic resin, and a silicone resin.

Further, in the optical device, for example, the optical component is a semiconductor laser module.

Further, the optical device includes, for example, an optical fiber that is inserted into the cover and optically coupled to the optical component.

According to the present invention, for example, it is possible to obtain an optical device which can be constructed at a lower cost and can secure a required temperature control performance.

FIG. 1 is an exemplary and schematic perspective view of the optical device of the embodiment. FIG. 2 is an exemplary and schematic side view of the optical device of the embodiment, including a cross section of the cover in II-II of FIG.

Hereinafter, exemplary embodiments of the present invention will be disclosed. The configurations of the embodiments shown below, as well as the actions and results (effects) brought about by the configurations, are examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments. Further, according to the present invention, it is possible to obtain at least one of various effects (including derivative effects) obtained by the configuration.

In this specification, ordinal numbers are given for convenience in order to distinguish parts, parts, etc., and do not indicate priorities or orders.

Further, in each figure, the X direction is represented by an arrow X, the Y direction is represented by an arrow Y, and the Z direction is represented by an arrow Z. The X, Y, and Z directions intersect and are orthogonal to each other. The X direction is also referred to as a longitudinal direction or an extension direction, the Y direction is also referred to as a lateral direction or a width direction, and the Z direction may be referred to as a height direction or a thickness direction.

[Embodiment]
FIG. 1 is a perspective view of the optical device 1 of the embodiment. Further, FIG. 2 is a side view of the optical device 1, which includes a cross section of the cover 10 in II-II of FIG.

As shown in FIGS. 1 and 2, the optical device 1 includes a cover 10, a temperature control device 20, a light emitting element 31, a lens 32, an optical fiber 33, a carrier 34, a support component 35, and a temperature sensor. 36 and.

As shown in FIGS. 1 and 2, the temperature control device 20 includes an upper substrate 21U, a lower substrate 21L, and a plurality of thermoelectric elements 22. The thermoelectric elements 22 are interposed between the upper substrate 21U and the lower substrate 21L, respectively.

The upper substrate 21U extends so as to intersect the Z direction. In the present embodiment, the upper substrate 21U extends in the X and Y directions and is orthogonal to the Z direction. The upper substrate 21U has an upper surface 20a facing in the Z direction and a lower surface 21b on the back side of the upper surface 20a. The upper substrate 21U can be made of an insulating material having high thermal conductivity, such as ceramic. The upper substrate 21U is an example of the first substrate, and the upper surface 20a is an example of the first surface. The Z direction is an example of the first direction.

Optical components such as the light emitting element 31, the lens 32, and the optical fiber 33 are mounted directly on the upper surface 20a or indirectly via other components. The upper substrate 21U may also be referred to as a mounting substrate, and the upper surface 20a may also be referred to as a mounting surface.

The lower substrate 21L is on the opposite side of the upper substrate 21U and extends so as to intersect the Z direction. In the present embodiment, the lower substrate 21L extends in the X and Y directions and is orthogonal to the Z direction. The lower substrate 21L has an upper surface 21a and a lower surface 20b that faces the opposite direction in the Z direction on the back side of the upper surface 21a. The lower substrate 21L can be made of an insulating material having high thermal conductivity, such as ceramic. The lower substrate 21L is an example of a second substrate and may also be referred to as a mounting substrate. Further, the lower surface 20b is an example of the second surface, and may also be referred to as a mounted surface.

The thermoelectric element 22 can be made of a P-type semiconductor or an N-type semiconductor, for example, a bismuth tellurium-based semiconductor.

Wiring patterns (not shown) are provided on the lower surface 21b of the upper substrate 21U and the upper surface 21a of the lower substrate 21L. Each of the thermoelectric elements 22 is interposed between these two wiring patterns. The wiring pattern can be made of a highly conductive metal material, such as a copper-based metal.

The general parts (insulating parts) of the upper substrate 21U and the lower substrate 21L can be made of, for example, low temperature co-fired ceramics (LTCC) or ceramics.

The plurality of thermoelectric elements 22 are connected in series so as to form a PN junction via a wiring pattern. The plurality of thermoelectric elements 22 generate heat or absorb heat by supplying electric power from the outside of the temperature control device 20 via the wiring pattern. The heat generation and endothermic reaction in the thermoelectric element 22 are switched depending on the direction of the current flowing through the plurality of thermoelectric elements 22. The wiring pattern can also be referred to as a conductor or conductor layer.

In the temperature control device 20, one of the upper surface 20a and the lower surface 20b is an endothermic surface and the other is a heat radiating surface. That is, in the temperature control device 20, depending on the direction of the electric current, the upper surface 20a becomes an endothermic surface and the lower surface 20b becomes an endothermic surface, and the upper surface 20a becomes a heat radiating surface and the lower surface 20b becomes an endothermic surface.

In this way, the temperature control device 20 functions as a base of the optical component, and adjusts the temperature of the optical component by heating or cooling the optical component. The temperature control device 20 may also be referred to as a Perche module or a thermoelectric module.

The light emitting element 31 which is an optical functional element is, for example, a semiconductor laser module, and an example is a wavelength tunable laser element. The light emitting element 31 is mounted on the upper surface 20a of the temperature control device 20 via the carrier 34. Further, the light emitting element 31 is an example of a photoelectric component driven by an electric signal.

The carrier 34 is made of an insulating material having high thermal conductivity, and transfers the heat generated by the light emitting element 31 to the temperature control device 20. The carrier 34 may also be referred to as a submount.

The light emitting element 31 outputs the laser beam toward the lens 32. The wavelength of the laser light is, for example, 900 nm or more and 1650 nm or less, which is suitable as a wavelength for optical communication. The light emitting element 31 functions as a heating element because the element temperature rises while the laser beam is being output.

The lens 32 collimates the laser beam from the light emitting element 31 by exerting an action due to the refractive index. The laser beam output from the lens 32 is input to the end of the optical fiber 33 supported by the support component 35. The optical fiber 33 is optically coupled to the light emitting element 31 and the lens 32.

The temperature sensor 36 detects the temperature of a predetermined portion. The temperature sensor 36 is, for example, a thermistor. The temperature sensor 36 detects, for example, the ambient temperature of the light emitting element 31. In this case, the detected temperature is used for controlling the temperature control device 20 for adjusting the temperature of the light emitting element 31.

As shown in FIGS. 1 and 2, the cover 10 partially covers the upper surface 20a of the upper substrate 21U. The cover 10 is a synthetic resin material such as an epoxy resin, an acrylic resin, or a silicone resin. The cover 10 is, for example, poured into the upper surface 20a of the upper substrate 21U of the temperature control device 20 set in the mold in a fluid state, and is solidified by cooling, heating, or irradiation with ultraviolet light.

The cover 10 is in contact with only the upper substrate 21U of the upper substrate 21U, the lower substrate 21L, and the thermoelectric element 22. In the present embodiment, the cover 10 is located in the Z direction with respect to the upper surface 20a of the upper substrate 21U.

As shown in FIG. 2, the cover 10 piled up on the upper surface 20a is a component provided on the upper surface 20a, that is, in the present embodiment, the light emitting element 31, the lens 32, the optical fiber 33, the carrier 34, and the support. The component 35 and the temperature sensor 36 are totally covered. These parts are embedded in the cover 10 and physically protected by the cover 10. The optical fiber 33 is inserted in the cover 10. The cover 10 may also be referred to as a sealing resin or a molding resin.

The cover 10 is made of a light-transmitting synthetic resin material that transmits the light transmitted by the light-emitting element 31. When the optical device 1 has a light receiving element as an optical component, the cover 10 is made of a light-transmitting synthetic resin material that transmits light received by the light receiving element.

The conductor 21c is exposed at a portion of the upper surface 20a that is detached from the cover 10, that is, a portion that is exposed without being covered by the cover 10. In other words, a conductor 21c exposed from the cover 10 is provided on the upper surface 20a.

The conductor 21c is electrically connected to a connecting conductor provided on the upper substrate 21U, for example, a connecting conductor (not shown) provided on the upper surface 20a or in the upper substrate 21U. Further, the connecting conductor is electrically connected to the light emitting element 31 (inner conductor) as a photoelectric component and the temperature sensor 36 (inner conductor). That is, the conductor 21c includes a conductor 21c that is electrically connected to the light emitting element 31 as a photoelectric component via a connecting conductor and a conductor 21c that is electrically connected to the temperature sensor 36 via the connecting conductor. include. The conductor 21c is used for electrical connection with an external device different from the optical device 1 or a conductor of the external device. The conductor 21c is, for example, a pad, and may also be referred to as an electrode or a terminal. Further, the connecting conductor is, for example, a wiring pattern, vias, bonding wires, or the like, and may also be referred to as wiring. The temperature sensor 36 may also be referred to as an electrical component or a thermoelectric component. The lower substrate 21L may also be provided with a conductor 21d electrically connected to the connecting conductor in the same manner as the conductor 21c.

The conductor portions provided on the upper substrate 21U and the lower substrate 21L, such as the conductor 21c, the connecting conductor, and the wiring pattern, are made of a highly conductive metal material such as a copper-based material.

According to the structure described above, the cover 10 has a component located on the upper surface 20a, that is, in the present embodiment, the liquid is applied to the light emitting element 31, the lens 32, the optical fiber 33, the carrier 34, the support component 35, and the temperature sensor 36. It prevents it from acting.

Further, the outer surface 10a of the cover 10 is covered with a coating 40 of an inorganic material. The coating 40 can be made of an aluminum-based metal material such as aluminum, aluminum oxide, or an aluminum alloy. Further, the coating film 40 may be made of a non-metallic material such as diamond-like carbon. The coating 40 prevents gas from acting on the components located on the upper surface 20a, that is, in the present embodiment, the light emitting element 31, the lens 32, the optical fiber 33, the carrier 34, the support component 35, and the temperature sensor 36. doing.

The inventors have conducted diligent research to prevent leakage of helium gas at a predetermined pressure when the coating 40 is made of a metal material or diamond-like carbon and the thickness of the coating 40 is 0.1 [μm] or more. It was confirmed that a good gas barrier property, that is, a gas barrier property that can ensure the reliability of optical parts can be guaranteed.

As described above, in the present embodiment, the optical device 1 includes a temperature control device 20 and optical components such as a light emitting element 31 provided on the upper surface 20a (first surface) of the temperature control device 20. A component including the component and a cover 10 for covering the component are provided. The cover 10 is made of a light-transmitting synthetic resin material that transmits light received or transmitted by an optical component.

According to such a configuration, for example, the optical device 1 can be manufactured at a lower cost because the cover 10 made of a synthetic resin material is provided and the housing made of a metal material or ceramic is not provided. Further, since the cover 10 is made of a light-transmitting synthetic resin material, even if the cover 10 is interposed between the plurality of optical components, the optical coupling between the plurality of optical components is ensured. be able to.

Further, in the present embodiment, for example, the cover 10 is provided only on the upper substrate 21U of the temperature control device 20 among the upper substrate 21U (first substrate), the lower substrate 21L (second substrate), and the thermoelectric element 22. I'm in contact.

According to such a configuration, for example, the cover 10 straddles between the upper substrate 21U and the lower substrate 21L, and heat is transferred between the upper substrate 21U and the lower substrate 21L by the straddling portion, and thus heat is transferred between the upper substrate 21U and the lower substrate 21L. , It is possible to avoid the difficulty in ensuring the temperature control performance of the temperature control device 20. Therefore, according to such a configuration, the required temperature control performance by the temperature control device 20 can be obtained more reliably. Further, when the cover 10 is interposed between the optical component and the upper substrate 21U, it is possible to secure a heat transfer path from the optical component to only the upper substrate 21U via the cover 10.

Further, in the present embodiment, for example, the cover 10 partially covers the upper surface 20a (first surface).

According to such a configuration, for example, the amount of the cover 10 can be reduced as compared with the case where the cover 10 covers the entire upper surface 20a, and the optical device 1 can be manufactured at a lower cost or lighter. You can get advantages such as optics.

Further, in the present embodiment, for example, a conductor 21c exposed from the cover 10 is provided at a portion of the upper surface 20a detached from the cover 10, and the conductor 21c is electrically connected to a photoelectric component such as a light emitting element 31. It is connected.

According to such a configuration, for example, a configuration in which the conductor 21c can be electrically connected to an external device or an external device different from the optical device 1 and the photoelectric component can be realized by a relatively simple configuration. ..

Further, in the present embodiment, for example, the optical device 1 includes a temperature sensor 36 covered with a cover 10.

According to such a configuration, for example, the temperature of each part in the cover 10 can be detected.

Further, in the present embodiment, for example, the outer surface 10a of the cover 10 is covered with the coating 40 of the inorganic material.

According to such a configuration, for example, even if the cover 10 made of a synthetic resin material has a configuration in which it is difficult to secure the gas barrier property, the film 40 can secure the required gas barrier property. That is, a configuration that physically protects the parts at a lower cost and protects them from liquids and gases can be realized by a relatively inexpensive and simple configuration.

Although the embodiments of the present invention have been exemplified above, the above-described embodiment is an example and is not intended to limit the scope of the invention. The above-described embodiment can be implemented in various other forms, and various omissions, replacements, combinations, and changes can be made without departing from the gist of the invention. In addition, specifications such as each configuration and shape (structure, type, direction, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) are changed as appropriate. Can be carried out.

For example, the optical device may include other components covered by a cover, other optical components, and other photoelectric components. Further, the optical device may be a device other than other semiconductor laser modules. Further, the layout of these parts is not limited to the above embodiment.

For example, the first coating film, the second coating film, and the third coating film may each be a so-called multilayer film in which a plurality of films are laminated, and in this case, for example, a diamond-like carbon film or an aluminum film. It may contain a film (layer) made of a different material.

1 ... Optical device 10 ... Cover 10a ... Outer surface 20 ... Temperature control device 20a ... Top surface (first surface)
20b ... Lower surface 21a ... Upper surface 21b ... Lower surface 21c ... Conductor 21d ... Conductor 21U ... Upper substrate (first substrate)
21L ... Lower board (second board)
22 ... Thermoelectric element 31 ... Light emitting element (optical component, photoelectric component)
32 ... Lens (optical component)
33 ... Optical fiber (optical component)
34 ... Carrier 35 ... Support component 36 ... Temperature sensor 40 ... Coating X ... Direction Y ... Direction Z ... Direction (first direction)

Claims (10)

It has a first surface facing the first direction and a second surface facing the opposite direction of the first direction on the opposite side of the first surface, and one of the first surface and the second surface. A temperature control device whose surface is an endothermic surface and the other surface is a heat radiating surface,
The optical components provided on the first surface and
A cover that is located on the first surface and covers the optical component and is made of a light-transmitting synthetic resin material that transmits light received or transmitted by the optical component.
With an optical device. The temperature control device includes a first substrate having the first surface, a second substrate having the second surface, and a thermoelectric element located between the first substrate and the second substrate. Have,
The optical device according to claim 1, wherein the cover is in contact with only the first substrate of the first substrate, the second substrate, and the thermoelectric element. The optical device according to claim 1 or 2, wherein the cover partially covers the first surface. The optical components include electrically driveable photoelectric components.
The optical device according to claim 3, wherein a conductor electrically connected to the photoelectric component and exposed from the cover is provided at a portion of the first surface detached from the cover. The optical device according to any one of claims 1 to 4, further comprising a temperature sensor covered with the cover. The optical device according to any one of claims 1 to 5, wherein the outer surface of the cover is covered with a coating film of an inorganic material. The optical device according to claim 6, wherein the coating film is a metal film. The optical device according to any one of claims 1 to 7, wherein the synthetic resin material is any one of an epoxy resin, an acrylic resin, and a silicone resin. The optical device according to any one of claims 1 to 8, wherein the optical component is a semiconductor laser module. The optical device according to any one of claims 1 to 9, further comprising an optical fiber inserted into the cover and optically coupled to the optical component.

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