OPTICAL DEVICE, SUBASSEMBLY OF OPTICAL DEVICE, AND METHOD OF MANUFACTURING OPTICAL DEVICE

An optical device includes: a case; a wiring substrate that passes through the case and that includes an insulating member and a conductor; at least one of components including a first component configured to perform at least one of: outputting a light; receiving a light; and varying optical properties, and a second component configured to electrically control the first component, the at least one of components being housed in the case and flip-chip mounted on the wiring substrate.

BACKGROUND

The present disclosure relates to an optical device, a subassembly of the optical device, and a method of manufacturing the optical device.

In the related art, an optical device is known that includes a feed-through which passes through a case (for example, refer to Japanese Patent Application Laid-open No. 2020-178117). A feed-through includes an insulating body and a plurality of terminals passing through the insulating body, and represents an assembly of terminals meant for securing electrical conduction between the inside and the outside of the case.

SUMMARY

Regarding this type of optical device, for example, if it becomes possible to achieve a new and improved configuration by which the number of components may be reduced and the optical device may be further downsized, it would be beneficial.

There is a need for an optical device having a new and improved configuration, a subassembly of the optical device and a method of manufacturing the optical device.

According to one aspect of the present disclosure, there is provided an optical device including: a case; a wiring substrate that passes through the case and that includes an insulating member and a conductor; at least one of components including a first component configured to perform at least one of: outputting a light; receiving a light; and varying optical properties, and a second component configured to electrically control the first component, the at least one of components being housed in the case and flip-chip mounted on the wiring substrate.

DETAILED DESCRIPTION

Exemplary embodiments are described below. The configurations explained in the embodiments described below as well as the actions and the results (effects) attributed to the configurations are only exemplary. Thus, the present disclosure may be implemented also using some different configuration than the configurations disclosed in the embodiments described below. Meanwhile, according to the present disclosure, it becomes possible to achieve at least one of various effects (including secondary effects) that are attributed to the configurations.

The embodiments described below include identical constituent elements. In the following explanation, the identical constituent elements are referred to by the same reference numerals, and their explanation is not given in a repeated manner.

In the present written description, ordinal numbers are assigned only for convenience and with the aim of differentiating among the components, among the parts, and among the directions. Thus, the ordinal numbers do not indicate the priority or the sequencing.

Moreover, in the drawings, the X direction is indicated by an arrow X, the Y direction indicated by an arrow Y, and the Z direction is indicated by an arrow Z. The X direction, the Y direction, and the Z direction intersect with each other and are orthogonal to each other.

First Embodiment

FIG.1is a planar view of an internal configuration of an optical device10.FIG.1is a diagram in which the optical device10is viewed from the opposite direction to the Z direction in the state in which a plate-like lid (not illustrated), which is positioned at the end portion in the Z direction of a case11of the optical device10, has been removed.

As illustrated inFIG.1, the optical device10includes the case11, a plurality of components12, a plurality of external connection pins13, a feed-through14, and a wiring substrate15.

The case11includes a bottom wall11a, a peripheral wall11b, ports11cand11d, and the lid (not illustrated). The bottom wall11ahas a substantially quadrangular shape and a plate-like shape. The bottom wall11aintersects with the Z direction and extends along the X and Y directions. The peripheral wall11bhas a substantially constant thickness and extends from the edge of the bottom wall in the Z direction. The peripheral wall11bmay also be called a sidewall.

The lid of the case11has a substantially quadrangular shape and a plate-like shape. The rim of the lid overlaps, in the Z direction, with the end edge in the Z direction of the peripheral wall lib. When the rim of the lid and the end edge in the Z direction of the peripheral wall11bare bonded together, a storage chamber S gets formed inside the case11for housing the components12and the wiring substrate (e.g., flexible substrate)15. The storage chamber S may be sealed in an airtight manner. Moreover, an inert gas may be filled in the storage chamber S.

The bottom wall11amay be made from a material having high thermal conductivity, such as copper-tungsten (CuW), copper-molybdenum (CuMo), or aluminum oxide (Al2O3). Moreover, the peripheral wall11band the lid may be made from a material having a low coefficient of heat expansion, such as an Fe—Ni—Co alloy or aluminum oxide (Al2O3).

The ports11cand11dhave a cylindrical shape and protrude, from some portion of the peripheral wall11b, in a lateral direction, that is, in the Y direction in the example illustrated inFIG.1. Of the ports11cand11d, one port is an input port, and the other port is an output port. An input optical fiber passes through the input port, and an output optical fiber passes through the output port. The space between the ports11cand11dand the peripheral wall11bis sealed in an airtight manner, and the spaces between the ports11cand11dand the respective optical fibers are also sealed in an airtight manner.

The components12are housed inside the storage chamber S, that is, inside the case11. At least one of the components12is flip-chip mounted on the wiring substrate15. The other components12are attached to a cooling mechanism (not illustrated) that is installed above or on the bottom wall11a. In that case, the other components12are electrically connected either to the conductor wiring of the wiring substrate15or to the external connection pins13via some other conductor (not illustrated) such as a bump, or the conductor of a flexible printed circuit board, or a bonding wire.

The components12are energized from the outside of the case11. That is, the components12receive the supply of electrical power from the outside of the case11. Each component12is either a first component meant for outputting a light, receiving (detecting) a light, and varying the optical properties such as the intensity, the wavelength, the modulating frequency, the polarization state, and the interference state; or is a second component that electrically controls the operations of at least one first component. That is, each component12is either an electrically-operating optical component or an electrical component. Examples of the component12representing a first component include a chip on submount (a light emitting unit), a wavelength locker representing a wavelength detector, a photodiode representing an optical receiver, a photodiode array, a modulator, a modulation driver, a coherent mixer, a transimpedance amplifier, a heater (a heating mechanism), and a thermoelectric cooler (TEC). Examples of the component12representing a second component include a controller that is a computer and an integrated circuit for controlling the operations of other electrical components or electronic components. Meanwhile, in the storage chamber S are also housed the optical components that do not operate electrically (not illustrated), such as a lens, a mirror, a beam combiner, a beam splitter, and an optical isolator.

The external connection pins13are attached to the feed-through14. The external connection pins13extend in the X direction and are arranged in the Y direction with a gap maintained therebetween. In the first embodiment, a single array of the external connection pins13arranged in the Y direction is positioned at the end portion in the X direction of the peripheral wall11band is placed along the portion (sidewall) extending in the Y direction; and another single array of the external connection pins13arranged in the Y direction is positioned at the end portion in opposite direction to the X direction and is placed along the portion (sidewall) extending in the Y direction. The external connection pins13may be made from a metallic material having high electrical conductivity, such as a copper base metal or an aluminum base metal. A copper base metal may be copper or a copper alloy, and an aluminum base metal may be aluminum or an aluminum alloy. To each external connection pin13, a conductor having external wiring (not illustrated) is either mechanically connected or electrically connected.

The feed-through14includes conductors and an insulating member, and passes through the peripheral wall11bof the case11. The conductors of the feed-through14may be made from a metallic material having high electrical conductivity, such as a copper base metal. The conductors of the feed-through14along with the external connection pins13, which are electrically connected to those conductors, constitute external connection conductors. The insulating member of the feed-through14may be made from an insulating material such as ceramic. The boundary between the feed-through14and the case11is sealed in an airtight manner.

The wiring substrate15passes through the peripheral wall11band extends across the inside and the outside of the case11. The wiring substrate15has a quadrangular and plate-like shape; and intersects with the Z direction and extends along the X and Y direction. In the first embodiment, the wiring substrate15passes through, in the Y direction, the portion at the end part in the Y direction of the peripheral wall11bof the case11. Meanwhile, the peripheral wall11brepresents an example of a first wall.

The wiring substrate15is a printed circuit board that includes an insulation layer and a plurality of conductor wirings. The insulation layer is made from an insulating material such as ceramic, glass, a synthetic resin material, or a mixed material thereof. The conductor wirings are made from a metallic material having high electrical conductivity, such as a copper base metal. In the first embodiment, the wiring substrate15is a rigid board. However, that is not the only possible case. Alternatively, the wiring substrate15may be a flexible board, or may be a rigid flexible board.

FIG.2is a cross-sectional view of the cross-sectional surface intersecting with the X direction of the optical device, and includes a side view of some components. As illustrated inFIG.2, the optical device10includes a heat transferring member18.

The wiring substrate15passes through an opening11b1that is formed on the peripheral wall11bof the case11. The opening11b1is a through hole formed through the peripheral wall11bin the Y direction, and has the shape of a slit extending in the X direction. In between the opening11b1and the wiring substrate15, a junction material16is provided for bonding the edge of the opening11b1and the wiring substrate15. Thus, using the junction material16, the gap between the edge of the opening11b1and the wiring substrate15is sealed in an airtight manner.

The wiring substrate15includes an insulation layer15aand conductor wirings15b. In the first embodiment, the conductor wirings15bare exposed on the surface positioned at the end portion in at least the opposite direction to the Z direction of the insulation layer15a. The insulation layer15arepresents an example of an insulating member, and the conductor wirings15brepresent examples of a conductor.

The wiring substrate15is a rigid board. For example, the wiring substrate15may be a single-sided board, a double-sided board, a multi-layer board, or a buildup board.

The components12are positioned in between the wiring substrate15and the bottom wall11a, and are flip-chip mounted on the wiring substrate15. That is, of each component12, an electrode12cinstalled on a face12afacing the wiring substrate15is mechanically and electrically connected to a pad of the corresponding conductor wiring15bvia a junction material17. The junction material17is a conductor such as a bump or a ball. For example, the junction material17is a solder ball.

The wiring substrate15is separated from the bottom wall11aof the case11in the Z direction. In between the components12, which are mounted on the wiring substrate15, and the bottom wall11a; heat transferring members18and19are provided via which the components12are thermally connected to the bottom wall11a. As a result, the heat generated due to the operations performed by the components12may be discharged to the outside of the optical device10via the heat transferring member19and the bottom wall11a. The bottom wall11aintersects with the peripheral wall11b, and represents an example of a second wall.

The heat transferring member18is a block made from a metallic material having high thermal conductivity, such as a copper base material; and may also be referred to a heat releasing block. The heat transferring member18is bonded to the bottom wall11ain a substantially coherent state using welding or adhesion. The heat transferring member18is thermally connected to the bottom wall11a.

The heat transferring member19is provided between a face12bof the concerned component12, which is on the opposite side of the face12a, and a face18aof the heat transferring member18, which is on the opposite side of the bottom wall11a. The heat transferring member19is, for example, an adhesive agent having high thermal conductivity. In this case, since the heat transferring member19is present in a pre-solidification fluid state between the concerned component12and the heat transferring member18, it becomes possible to absorb the variability in the gap between the component12and the heat transferring member18. The heat transferring member19may be a heat conducting sheet that has thermal conductivity, that is flexible, and that is deformable. In that case, due to the deformation of the heat transferring member19, it becomes possible to absorb the variability in the gap between the concerned component12and the heat transferring member18.

The heat transferring member18is substantially coherent also with the peripheral wall11b. That is, in the first embodiment, the components12are thermally connected also to the peripheral wall11bvia the heat transferring members18and19. As a result, as compared to the case in which the components12are thermally connected only to the bottom wall11a, the heat generated due to the operations performed by the components12may be more easily discharged to the outside of the optical device10.

Each conductor wiring15bof the wiring substrate15is electrically connected to a conductor wiring20bof an external substrate20provided on the outside of the case11via a junction material21. The external substrate20is a wiring substrate that includes an insulation layer20aand the conductor wirings20b; and represents a rigid board or a flexible board. For example, the external substrate20may be a transceiver substrate meant for transmitting electrical signals such as RF signals having a relatively higher frequency. In that case, electrical signals having a relatively higher frequency are transmitted to the conductor wiring20b, the junction material21, and the conductor wiring15bof the wiring substrate15.

Meanwhile, in between the external connection pins13and the other components12not illustrated inFIG.2, for example, direct-current power or an electrical signal having a relatively lower frequency is transmitted via some other conductors other than the conductors in the feed-through14.

As explained above, in the first embodiment, the wiring substrate15on which the components12are flip-chip mounted passes through the peripheral wall11bof the case11. Herein, it may be said that the wiring substrate15is formed when a feed-through or an interface substrate is integrated with a wiring substrate disposed inside the case11(the storage chamber S). As a result of such integration, for example, it becomes possible to reduce the number of components of the optical device10. Meanwhile, alternatively, a single wiring substrate15illustrated inFIG.1and two field-throughs14may be integrated into a single wiring substrate.

Moreover, in the first embodiment, the wiring substrate15is a rigid substrate. With such a configuration, for example, at the time of assembling the optical device10, the wiring substrate15may be handled with more ease.

Second Embodiment

FIG.3is a cross-sectional view of the cross-sectional surface intersecting with the X direction of an optical device10A according to a second embodiment, and includes a side view of some components. As illustrated inFIG.3, the optical device10A includes a supporting member22that supports a wiring substrate15A. The supporting member22passes through the opening11b1formed on the peripheral wall11b. That is, the supporting member22has a portion housed in the case11and a portion exposed to the outside of the case11. The supporting member22is bonded in a substantially coherent manner to the bottom wall11ausing welding or adhesion. In between the wiring substrate15A and the supporting member22, the junction material16is filled.

In the second embodiment, the wiring substrate15A is a flexible substrate. With such a configuration, for example, it becomes possible to enhance the freedom in the layout of the wiring substrate15A inside the storage chamber S, and to absorb the dimensional variability in the components attributed to the bend (curve) of the wiring substrate15A.

Third Embodiment

FIG.4is a cross-sectional view of the cross-sectional surface intersecting with the X direction of an optical device10B according to a third embodiment, and includes a side view of some components. As illustrated inFIG.4, in the optical device10B, a heat transferring member18B supports the wiring substrate15A and passes through the opening11b1formed on the peripheral wall11b. The heat transferring member18B includes a portion housed in the case11, and includes a heat releasing unit18bexposed to the outside of the case11. The heat releasing unit18bincludes, for example, a plurality of fins, a plurality of pins, and an uneven structure. With such a configuration, due to the heat releasing unit18bhaving a larger surface area, it becomes possible to enhance the heat dissipation from the heat transferring member18B. As a result, the heat generated due to the operations performed by the components12may be discharged to the outside of the optical device10B with more ease.

Meanwhile, via the heat transferring member19, the heat transferring member18B is thermally connected also to the lateral face positioned at the end portion in the opposite direction to the Y direction of the concerned component12. With such a configuration, for example, since the heat transferring member18B is thermally connected to a plurality of faces of the concerned component12, the amount of heat transferred from the concerned component12to the heat transferring member18B may be increased, thereby making it further easier to discharge the heat, which is generated due to the operations performed by the component12, to the outside of the optical device10B.

Fourth Embodiment

FIG.5is a cross-sectional view of the cross-sectional surface intersecting with the X direction of an optical device10C according to a fourth embodiment, and includes a side view of some components. As illustrated inFIG.5, in the optical device10C, the opening11b1is formed at the boundary portion between the end portion in the Z direction of the peripheral wall11band an apex wall11eserving as the lid of the case11. In that case, the opening11b1may be formed in between a notch formed at the end portion in the Z direction of the peripheral wall11band the apex wall11e. In this way, the opening11b1may be formed at the boundary of two members that constitute the case11. With such a configuration, for example, since a notch may be formed while forming the end portion of the peripheral wall lib, as compared to the case in which the opening11b1is separately formed on the peripheral wall lib, the time and efforts as well as the cost of manufacturing the case11, and in turn manufacturing the optical device10C, may be reduced.

The wiring substrate15A may include a through conductor15cthat is electrically connected to the conductor wiring15band that passes through the wiring substrate15A in the thickness direction. The through conductor15crepresents an example of a conducting member and may also be referred to as conductor wiring.

Alternatively, the wiring substrate15A may include the through conductor15cpositioned inside the storage chamber S. As a result of having the through conductor15c, for example, on the opposite side to the side on which the components12are mounted on the wiring substrate15A, it becomes possible to connect the conductor wiring15bwith other conductors and the components12. Hence, it becomes possible to have a more efficient layout of the components12and the conductors inside the storage chamber S.

Fifth Embodiment

FIG.6is a cross-sectional view in the Y direction of an optical device10D according to a fifth embodiment, and includes a side view of a wiring substrate15D. As illustrated inFIG.6, in the fifth embodiment, on the edge of the opening11b1, nail-shaped protrusions11fare formed that protrude toward the inside of the opening11b1. The wiring substrate15D engages with the protrusions11fand gets positioned in the Y direction. The protrusions11fmay engage with the wiring substrate15D in a digging manner toward the inside of the wiring substrate15D, or may engage with the wiring substrate15D in an abutting manner with the recession or the step (not illustrated) formed on the surface of the wiring substrate15D. With such a configuration, for example, the wiring substrate15D may be positioned and fixed with respect to the case11with more ease.

In the fifth embodiment, a gap g is maintained between the edge of the opening11b1and the wiring substrate15D. When there is no need of airtight sealing of the storage chamber S, the gap g may be left as it is. Alternatively, as explained in the earlier embodiments, the gap g may be filled with the junction material16(seeFIGS.1to5).

Moreover, on the surface of the wiring substrate15D, at least in the portion that passes through the opening11b1, an external conductor15b2of the conductor wiring15bis disposed to enclose the surrounding of the insulation layer15a. The external conductor15b2may be a ground conductor that is electrically connected to the ground terminal (not illustrated) of the optical device10D. Moreover, inside the insulation layer15a, internal conductors15b1of the conductor wiring15bare disposed. The internal conductors15b1are surrounded by the insulation layer15a.

With such a configuration, for example, the insulation property of the internal conductors15b1may be easily secured using the insulation layer15a, and the noise resistance of the internal conductors15b1may be enhanced using the external conductor15b2. Moreover, if the external conductor15b2and the peripheral wall11bare made from a metallic material; then, as the junction material16to be filled in the gap g, for example, it becomes possible to use a junction material such as a solder that has high affinity to the external conductor15b2as well as the peripheral wall11b. In that case, for example, the gap g may be filled with the junction material16with more ease or with more reliability.

Sixth Embodiment

FIG.7is a cross-sectional view in the Y direction of an optical device10E according to a sixth embodiment, and includes a side view of the wiring substrate15D. As illustrated inFIG.7, according to the sixth embodiment, the wiring substrate15D is press-fit in the opening11b1. With such a configuration, for example, the junction material16and the protrusions11fare no more required, thereby making it possible to reduce the number of components of the optical device10E and to reduce the time and efforts during manufacturing.

Seventh Embodiment

FIG.8is a cross-sectional view in the Y direction of an optical device10F according to a seventh embodiment, and includes a side view of a wiring substrate15F. As illustrated inFIG.8, according to the seventh embodiment, the wiring substrate15F includes two wiring substrates15-1and15-2that are coupled together. The wiring substrate15-1as well as the wiring substrate15-2includes external conductors15b2on both sides in the thickness direction (the Z direction) of the insulation layer15aand at least in the portion positioned inside the opening11b1. The external conductors15b2that are adjacent to each other in the Z direction are mechanically and electrically connected using a junction material24having electrical conductivity. As a result, the wiring substrates15-1and15-2are integrated. The junction material24may be a solder made from a material that has high affinity to the external conductors15b2. Meanwhile, the edge of the opening11b1and the wiring substrate15F are bonded using the junction material16. In that case, the junction material16and the junction material24may be made from the same material. The wiring substrates15-1and15-2may be coupled inside the opening11b1. With such a configuration, for example, the airtight sealing between the edge of the opening11b1and the wiring substrate15F may be performed with more ease or with more reliability using the junction materials16and24.

Eighth Embodiment

FIG.9is a cross-sectional view in the Y direction of an optical device10G (10) according to an eighth embodiment, and includes a side view of the wiring substrate15. InFIG.9is illustrated the state in which a subassembly100G and the case11are yet to be assembled. The optical device10G according to the seventh embodiment includes the same constituent elements as the constituent elements of the optical device10according to the first embodiment.

In the eighth embodiment, firstly, the subassembly100G is manufactured by mounting the component12on the wiring substrate15. At that time, for example, the component12is flip-chip mounted on the wiring substrate15. The subassembly100G is configured to be attachable to the peripheral wall11bof the case11.

Subsequently, as illustrated inFIG.9, in the state of the subassembly100G, the wiring substrate15is inserted into the opening11b1on the peripheral wall11bof the case11; and, as soon as a predetermined positional relationship is achieved, the subassembly100G is fixed to the case11using the junction material16and the heat transferring member19. In that predetermined positional relationship, the components12are positioned on the opposite side of an outer face11b2of the case11with reference to the peripheral wall11b. As a result, the subassembly100G gets integrated with some portion of the case11, and then that portion of the case11is assembled with the remaining portion. With such a configuration, for example, the component12may be mounted on the wiring substrate on the outside of the case11. Thus, as compared to the case in which the component12is mounted on the wiring substrate15inside the case11, the component12may be mounted with more ease, or with more speed, or with more reliability. Meanwhile, the peripheral wall11brepresents an example of a wall of the case11.

When the subassembly100G is configured to be attachable to the peripheral wall11bof the case11; it implies that, in the state in which the wiring substrate15has passed through the opening11b1formed on the peripheral wall11b, the wiring substrate15, the component12, and the case11(the peripheral wall11b) satisfy a predetermined positional relationship in the optical device10(10G).

Ninth Embodiment

FIG.10is an exploded cross-sectional view in the Y direction of an optical device10H according to a ninth embodiment, and includes a side view of the wiring substrate15. InFIG.10is illustrated the state in which a subassembly100H and the case11are yet to be assembled.FIG.11is an exploded cross-sectional view in the Y direction of the optical device10H. InFIG.11is illustrated the state in which the subassembly100H and the case11are assembled.

In the ninth embodiment too, firstly, the component12is mounted on the wiring substrate15. At that time, for example, the component12is flip-chip mounted on the wiring substrate15. Moreover, the wiring substrate15passes through the opening11b1that is formed on a first portion11b-1representing a part of the peripheral wall11b; and, as soon as a predetermined positional relationship is achieved, the wiring substrate15and the first portion11b-1are integrated using the junction material16. As a result, the subassembly100H illustrated inFIG.10is formed. That is, the subassembly100H according to the ninth embodiment includes some portion of the wall of the case11, in addition to including the wiring substrate15and the components12. In that predetermined positional relationship, the component12is positioned on the opposite side to the outer face11b2of the case11with reference to the first portion11b-1. Herein, the first portion11b-1represents an example of a first wall.

Subsequently, as illustrated inFIGS.10and11, in the state of the subassembly100H, the first portion11b-1of the peripheral wall11band a second portion11b-2of the peripheral wall11bare bonded by welding in welding portions11g, so that the subassembly100H gets integrated with the case11excluding the first portion11b-1. The first portion11b-1and the second portion11b-2are configured to be attachable to each other. In the ninth embodiment, as an example, in the boundary region between the first portion11b-1and the second portion11b-2, a fitting structure made of textured patterns is provided. As a result, during the process of integrating the subassembly100H with the case11excluding first portion11b-1, a predetermined positional relationship between the first portion11b-1and the second portion11b-2may be achieved with more ease, or with more speed, or with more reliability. According to the ninth embodiment too, for example, in an identical manner to the eighth embodiment, the component12may be mounted on the wiring substrate15with more ease, with more speed, or with more reliability. Meanwhile, as long as the attachable configuration is such that the first portion11b-1and the second portion11b-2are linked in an integrated manner to constitute the case11, it serves the purpose. Thus, the fitting structure is not a mandatory structure.

FIG.12is an exploded perspective view of an optical device10I according to a 10-th embodiment. As illustrated inFIG.12, in the 10-th embodiment, a subassembly100I includes a sidewall representing some portion of the peripheral wall11band includes a wiring substrate15I on which the components12(not illustrated inFIG.12) are flip-chip mounted. Moreover, the case11includes the bottom wall11a; a first divided portion11-1including the peripheral wall11bnot included in the subassembly100I; and a second divided portion11-2including the apex wall11eserving as the lid. The peripheral wall11bof the subassembly100I is configured to be attachable to the bottom wall11a, the peripheral wall lib, and the apex wall11eincluded in the first divided portion11-1or the second divided portion11-2. Herein, as long as the attachable configuration is such that the walls are linked in an integrated manner to constitute the case11, it serves the purpose. Thus, a fitting structure is not mandatory.

When the subassembly100I, the first divided portion11-1, and the second divided portion11-2are bonded together, the optical device10I is obtained. In the 10-th embodiment, some portion of the peripheral wall11bincluded in the subassembly100I represents an example of a first wall and a first portion. Moreover, the bottom wall11a, the peripheral wall lib, and the apex wall11eincluded in the first divided portion11-1or the second divided portion represent an example of a second portion.

In the 10-th embodiment, at the time of assembling the first divided portion11-1and the second divided portion11-2; the portion in which an edge11hof the bottom wall11aof the case11, an edge11hof the peripheral wall11bof the case11, and an edge11hof the apex wall11eof the case11may be butted is linearly welded, so that the optical device10I may be configured. As far as linear welding is concerned, it is possible to implement various welding methods such as roller seam welding or laser welding. With such a configuration, for example, the components12may be mounted on the wiring substrate15I with more ease or with more reliability, and the optical device10I may be formed with more ease.

For example, the first portion may include a plurality of walls of the case, and the second portion too may include a plurality of walls of the case.

According to the present disclosure, it becomes possible to achieve an optical device having a new and improved configuration, and to achieve a subassembly of the optical device and a method of manufacturing the optical device.