JP7583604B2 - Housing for optical device, optical device, laser welding device, and laser welding method - Google Patents

Description

The present invention relates to a housing for an optical device, an optical device, a laser welding device, and a laser welding method.

Conventionally, optical devices in which optical components are housed in a box-shaped housing are known (for example, see Patent Document 1). In Patent Document 1, the housing is made by joining multiple members.

JP 2002-131585 A

In this type of optical device, if spatter occurs when manufacturing the housing by laser welding multiple components, there is a risk that the spatter may fly to other parts of the housing and damage its appearance, or that the spatter may enter the housing and affect the optical components.

Therefore, one of the objectives of the present invention is to provide an improved and new optical device housing, optical device, laser welding device, and laser welding method that are less likely to cause problems due to laser welding, for example, when manufacturing an optical device housing by laser welding multiple components.

The housing of the optical device of the present invention is, for example, a housing of an optical device that constitutes a storage chamber for an optical component, and includes a plate-shaped first member having a first outer surface and a first edge that form the outer surface of the housing, a plate-shaped second member having a second outer surface and a second edge that extends along the first edge, and a linear weld that welds a portion between the first outer surface and the second outer surface among the boundary portions between the first edge and the second edge, and the weld extends from between the first outer surface and the second outer surface in a second direction that intersects with the first direction along the first outer surface and the first edge, and the boundary portion includes an opposing section that extends in a third direction that intersects with the first direction and the second direction as an opposing section where the first edge and the second edge face or contact with a gap between the weld and the storage chamber.

In the housing of the optical device, the boundary portion may include an intermediate chamber in which the distance between the first edge and the second edge in a cross section intersecting the first direction is greater than in other portions.

In the housing of the optical device, the maximum value of the distance may be 0.2 mm or more in a cross section intersecting the first direction.

In the housing of the optical device, the boundary portion may include, as the opposing section, a plurality of opposing sections arranged in series between the welded portion and the storage chamber and extending in different directions.

In the housing of the optical device, the first edge and the second edge may be in contact with each other in at least a portion of the opposing section.

In the housing of the optical device, the boundary portion may include, as the opposing section, an opposing section that extends substantially along the thickness direction of one of the first and second members for a length equal to or greater than half the thickness of the one member.

In the housing of the optical device, the misalignment between the first outer surface and the second outer surface in the second direction may be 0.1 mm or less.

In the housing of the optical device, the weld may be provided circumferentially.

In the housing of the optical device, the chamber may be hermetically sealed at the welded portion.

In the housing of the optical device, the first member may be a member constituting a lid of the housing that closes an opening in a peripheral wall of the housing, the second member may be a member constituting the peripheral wall, the first edge may be a peripheral edge of the lid, and the second edge may be a peripheral edge of the peripheral wall that extends along the first edge.

The optical device of the present invention also includes, for example, a housing for the optical device and an optical component housed in the housing chamber.

The laser welding apparatus of the present invention is, for example, a housing for an optical device that constitutes a storage chamber for an optical component, and includes a plate-shaped first member having a first outer surface that becomes the outer surface of the housing and a first edge, and a plate-shaped second member having a second outer surface that becomes the outer surface of the housing and a second edge extending along the first edge, and the boundary portion between the first edge and the second edge includes a first opposing section that extends from between the first outer surface and the second outer surface in a second direction that intersects with a first direction along the first outer surface and the first edge, and a first opposing section that is interposed between the first opposing section and the storage chamber, and the first edge and the second edge face each other with a gap therebetween or are in close contact with each other. A laser welding device that irradiates a laser beam to weld the first edge and the second edge to the housing, the housing being configured to include a second opposing section that at least partially extends in a third direction that intersects the first direction and the second direction, the laser welding device comprising a laser oscillator and an optical head that emits laser beams from the laser oscillator, the laser beams including at least one main beam and at least one sub-beam having a power density lower than that of the main beam, and the laser beams are irradiated and swept toward the first opposing section to form a linear weld adjacent to the first outer surface and the second outer surface.

The laser welding device may include a beam shaper that shapes the laser light beam.

The laser welding method of the present invention may, for example, be a housing for an optical device that constitutes a storage chamber for an optical component, and may include a plate-shaped first member having a first outer surface that is the outer surface of the housing and a first edge, and a plate-shaped second member having a second outer surface that is the outer surface of the housing and a second edge that extends along the first edge, and the boundary portion between the first edge and the second edge includes a first opposing section that extends from between the first outer surface and the second outer surface in a second direction that intersects with a first direction along the first outer surface and the first edge, and a first opposing section that is interposed between the first opposing section and the storage chamber and in front of the first edge. A laser welding method for welding the first edge and the second edge by irradiating a laser beam to the housing, the housing being configured to include a second opposing section that faces or contacts the second edge with a gap therebetween and extends at least partially in a third direction that intersects the first direction and the second direction, the laser beam including at least one main beam and at least one sub-beam having a power density lower than that of the main beam, and the laser beam is irradiated toward the first opposing section while sweeping to form a linear weld adjacent to the first outer surface and the second outer surface.

The present invention provides an improved and novel optical device housing, optical device, laser welding apparatus, and laser welding method.

FIG. 1 is an exemplary schematic side view (partial cross-sectional view) showing the internal configuration of an optical device according to a first embodiment. FIG. 2 is an enlarged view of part II in FIG. FIG. 3 is an exemplary schematic cross-sectional view of a welding structure formed on a housing of an optical device according to a first modified example of the first embodiment, taken at the same position as in FIG. 2. In FIG. FIG. 4 is an exemplary schematic cross-sectional view of a welding structure formed on a housing of an optical device according to a second modified example of the first embodiment, taken at the same position as in FIG. 2. In FIG. FIG. 5 is an exemplary schematic cross-sectional view of a welding structure formed on a housing of an optical device according to a third modified example of the first embodiment, taken at the same position as in FIG. 2. In FIG. FIG. 6 is an exemplary schematic cross-sectional view of a welding structure formed on a housing of an optical device according to a fourth modified example of the first embodiment, taken at the same position as in FIG. 2. In FIG. FIG. 7 is an exemplary schematic configuration diagram of a laser welding device according to the second embodiment. FIG. 8 is an explanatory diagram showing the concept of the principle of the diffractive optical element included in the laser welding apparatus of the second embodiment. FIG. 9 is a schematic diagram showing an example of a beam (spot) on a surface of a target object of the laser welding device of the second embodiment. FIG. 10 is a schematic diagram showing another example of a beam (spot) on the surface of a target object of the laser welding apparatus of the second embodiment. FIG. 11 is a schematic diagram showing yet another example of a beam (spot) on a surface of a target object of the laser welding apparatus of the second embodiment.

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

The embodiments and modified examples shown below have similar configurations. According to the configuration of each embodiment and modified example, similar actions and effects based on the similar configurations can be obtained. Furthermore, in the following, the similar configurations are given the same reference numerals, and duplicate explanations may be omitted.

In this specification, ordinal numbers are used for convenience to distinguish parts, locations, directions, etc., and do not indicate priority or order.

In addition, 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 direction, Y direction, and Z direction intersect with each other and are perpendicular to each other.

[First embodiment]
Fig. 1 is a side view showing the internal configuration of the optical device 1 of the first embodiment. As shown in Fig. 1, the optical device 1 includes a housing 10 and components such as a temperature control device 20, a light emitting element 41, a lens 42, a carrier 43, an optical isolator 51, a beam splitter 52, and a light receiving element 53 housed in the housing 10. The light receiving element 53 is, for example, a photodiode.

The housing 10 has a top wall 11, a bottom wall 12, two side walls 13, and two side walls 14 as walls. The housing 10 has, for example, a rectangular parallelepiped and box-like shape. Within the housing 10, a storage chamber R is formed that is surrounded by the top wall 11, the bottom wall 12, the two side walls 13, and the two side walls 14.

The bottom wall 12 extends in a direction that intersects with the Z direction. In this embodiment, the bottom wall 12 extends in the X direction and the Y direction and is perpendicular to the Z direction.

In the accommodation chamber R, an optical component is attached on the bottom wall 12 via a temperature adjustment device 20. The optical component may be attached on the temperature adjustment device 20 via a base plate made of ceramic such as aluminum oxide (Al ₂ O ₃ ) or aluminum nitride (AlN). The bottom wall 12 may also be referred to as a support portion or a support wall.

The top wall 11 extends in a direction that intersects with the Z direction. In this embodiment, the top wall 11 extends in the X direction and the Y direction and is perpendicular to the Z direction.

The side walls 13 each extend in a direction that intersects with the X direction. In this embodiment, the side walls 13 extend in the Y direction and the Z direction and are perpendicular to the X direction. The side walls 13 are each located at the ends of the housing 10 in the X direction (longitudinal direction).

An optical window 15 is provided in one of the side walls 13.

The other side wall 13, on which the optical window 15 is not provided, is provided with a feedthrough 16 that penetrates the side wall 13 in the thickness direction (X direction). The feedthrough 16 can also be said to constitute a part of the housing 10. The feedthrough 16 may also have a portion that penetrates the side wall 14.

The side walls 14 extend in a direction that intersects with the Y direction. In this embodiment, the side walls 14 extend in the X and Z directions and are perpendicular to the Y direction. The side walls 14 are located at the ends of the housing 10 in the width direction. The side walls 13 and 14 can also be referred to as peripheral walls.

The top wall 11 may be made of a metal material such as Kovar, FeNi, or aluminum. The surface of the top wall 11 may be provided with a plating layer of Ni, NiAu, NiPtAu, NiPdAu, or the like. In addition, the joint surfaces of the top wall 11 that are joined to the side walls 13 and 14 may be provided with a layer of brazing material such as silver or AuSn.

The side walls 13, 14 may be made of a metal material such as Kovar. The surfaces of the side walls 13, 14 may be provided with a plating layer of Ni, NiAu, NiPtAu, NiPdAu, or the like. The joint surfaces of the side walls 13, 14 with the top wall 11 may be provided with a brazing material layer of silver, AuSn, or the like. In addition, only the portions of the side walls 13, 14 including the joint surfaces with the top wall 11 may be made of a metal material, and the other portions may be made of a ceramic such as aluminum oxide or aluminum nitride. Note that the plating layer or brazing material layer is not essential for the top wall 11 and the side walls 13, 14.

The bottom wall 12 can be made of a metal material such as a Cu-tungsten alloy or a CuMo alloy.

The feedthrough 16 may also be made of a ceramic, such as aluminum oxide or aluminum nitride.

The temperature adjustment device 20 has an upper substrate 21U, a lower substrate 21L, and a number of thermoelectric elements 22. The upper substrate 21U and the lower substrate 21L are arranged along the bottom wall 12. The thermoelectric elements 22 are respectively interposed between the upper substrate 21U and the lower substrate 21L.

The upper substrate 21U extends across the Z direction and has an upper surface 20a and a lower surface 21b on the back side of the upper surface 20a. The upper substrate 21U may be made of an insulating material with high thermal conductivity, such as ceramic. Optical components such as the light-emitting element 41, lens 42, optical isolator 51, beam splitter 52, and light-receiving element 53 are attached directly to the upper surface 20a or indirectly via other components such as a base plate. The upper substrate 21U may also be referred to as a first substrate or a mounting substrate, and the upper surface 20a may also be referred to as a mounting surface.

The lower substrate 21L extends across the Z direction and has an upper surface 21a and a lower surface 20b behind the upper surface 21a. The lower substrate 21L may be made of an insulating material with high thermal conductivity, such as ceramic. The lower substrate 21L is attached to the bottom wall 12 of the housing 10 while being thermally connected to the bottom wall 12. The lower substrate 21L may also be referred to as a second substrate or a mounting substrate, and the lower surface 20b may also be referred to as a contact surface or a mounting surface.

The thermoelectric element 22 is an example of a semiconductor element and can be made of a P-type or N-type semiconductor, such as a bismuth telluride-based semiconductor.

A wiring pattern (not shown) is provided on the lower surface 21b of the upper substrate 21U and the upper surface 21a of the lower substrate 21L. The thermoelectric elements 22 are each 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 multiple thermoelectric elements 22 are connected in series to form a PN junction via the wiring pattern. The multiple thermoelectric elements 22 generate or absorb heat when power is supplied from outside the temperature control device 20 via the wiring pattern. The generation and absorption of heat in the thermoelectric elements 22 is switched depending on the direction of the current flowing through the multiple thermoelectric elements 22. The wiring pattern may also be referred to as a conductor or a conductor layer.

In this way, the temperature adjustment device 20 functions as a base for the optical components, and adjusts the temperature of the optical components by heating or cooling them. The temperature adjustment device 20 can also be called a Peltier module or a thermoelectric module.

The light-emitting element 41, which is an optical functional element, is, for example, a semiconductor laser element, and in this case, the optical device 1 is a wavelength-tunable laser module. In addition, the optical element may be an optical modulator element and the optical device may be an optical modulator module, the optical element may be a photodiode and the optical device may be an optical receiver module, or the optical device may be an integrated coherent-transmitter receiver optical sub-assembly (IC-TROSA) in which a semiconductor laser element, a photodiode element, and an optical modulator element are integrated. The light-emitting element 41 is mounted on the upper surface 20a of the temperature control device 20 via a carrier 43. The carrier 43 is made of an insulating material with a linear expansion coefficient close to that of the light-emitting element 41 or an insulating material with high thermal conductivity, and transmits heat generated by the light-emitting element 41 to the temperature control device 20. The carrier 43 may also be called a submount.

The light-emitting element 41 outputs laser light toward the lens 42. The wavelength of the laser light is, for example, 900 nm or more and 1650 nm or less, which is a suitable wavelength for optical communication. The element temperature of the light-emitting element 41 increases while the laser light is being output, and the light-emitting element 41 functions as a heating element. The light-emitting element 41 is, for example, a semiconductor laser element.

The lens 42 is attached to the carrier 43. The lens 42 collimates the laser light from the light-emitting element 41 by applying a refractive index effect. The laser light output from the lens 42 is input to the optical isolator 51.

The optical isolator 51 has a magnet 51a and an optical element section 51b including a magneto-optical element and a polarizing plate. The optical isolator 51 polarizes the laser light from the optical element section 51b and exerts a magneto-optical effect on the laser light from the optical element section 51b. The laser light output from the optical isolator 51 is input to the beam splitter 52. The optical isolator 51 prevents the light from the beam splitter 52 from passing toward the light-emitting element 41.

The beam splitter 52 outputs the laser light from the optical isolator 51 to the outside of the optical device 1, and also splits the laser light from the optical isolator 51 and inputs it to the light receiving element 53.

The housing 10 is hermetically sealed, which prevents air and water from acting on the optical components contained within the housing 10, such as the light-emitting element 41, lens 42, optical isolator 51, beam splitter 52, and light-receiving element 53. The optical device 1 is configured so that an inert gas, such as nitrogen gas, filled in the housing 10 during manufacture does not leak out of the housing 10.

A flexible printed wiring board 30 is also connected to the optical device 1. In this embodiment, the flexible printed wiring board 30 is fixed to the feedthrough 16. A fastener such as a screw (not shown) or an adhesive may be used to fix the flexible printed wiring board 30 to the feedthrough 16 or the housing 10.

Driving power and control signals are supplied from a higher-level device (not shown) to the light-emitting element 41 and the temperature adjustment device 20 via the conductors in the flexible printed wiring board 30. In addition, a detection signal is sent from a sensor (not shown) in the accommodation chamber R to the higher-level device via the conductors in the flexible printed wiring board 30.

Figure 2 is an enlarged view of part II in Figure 1. Figure 2 shows a cross section of a welding structure 60A (60) formed on the housing 10, which welds the top wall 11 and the side wall 13 together. Note that a welding structure 60A similar to that in Figure 2 is also provided between the top wall 11 and the side wall 14.

2, in this embodiment, the peripheral edge 11b of the top wall 11 and the edge 13b of the side wall 13 are joined via a weld 61. The weld 61 is formed by irradiating the laser light L to form a molten pool, which is cooled and solidified. That is, the top wall 11 and the side wall 13 are laser welded. The top wall 11 is a member that constitutes the lid of the housing 10 that closes the openings of the side walls 13 and 14, and is an example of a first member. The side walls 13 and 14 are members that constitute the peripheral walls of the housing 10, and are an example of a second member. The peripheral edge 11b is an example of a first edge. The edge 13b is a linear edge that extends along the peripheral edge 11b, and is an example of a second edge.

The edge 13b, together with the edges of the other side walls 13 and side walls 14, constitutes a peripheral edge along the periphery 11b. The welded structure 60 is not limited to between the side walls 13 and the top wall 11, but may be formed, for example, at the corner A between the side walls 13 and the bottom wall 12 shown in FIG. 1, or at a corner (not shown) between the side walls 14 and the bottom wall 12, or at the butt joint (not shown) of two members aligned in the extension direction.

2, the welded portion 61 is located between the outer surface 11s of the top wall 11 and the outer surface 13s of the side wall 13. Both outer surfaces 11s and 13s extend across the Z direction, in other words, they extend in the X and Y directions. As an example, the outer surfaces 11s and 13s are substantially flush with each other, and the deviation in the Z direction is set to 0.1 mm or less. The outer surface 11s is an example of a first outer surface, and the outer surface 13s is an example of a second outer surface.

In this embodiment, the boundary portion B between the periphery 11b and the edge 13b extends between the outer surface 11s and the outer surface 13s and between the storage chamber R. The boundary portion B has two sections B1 and B2. Section B1 is adjacent to the outer surfaces 11s and 13s. Sections B1 and B2 are arranged in series, and section B2 is located closer to the storage chamber R than section B1. As is clear from FIG. 2, in the cross section of FIG. 2, the boundary portion B is bent in an L-shape. That is, the direction in which section B1 extends and the direction in which section B2 extends intersect with each other. Section B1 extends in the Z direction from between the outer surface 11s and the outer surface 13s toward the storage chamber R, and section B2 extends in the opposite direction to the X direction from the end of section B1 on the storage chamber R side toward the storage chamber R side.

The welded portion 61 joins the periphery 11b and the end edge 13b in section B1. Note that in FIG. 2, the boundary portion B of the welded portion 61 before the welded portion 61 is formed is shown by a two-dot chain line.

Here, FIG. 2 is a cross section intersecting with the Y direction. In other words, in the portion where the cross section of FIG. 2 is formed, the periphery 11b, the edge 13b, the outer surface 11s, the outer surface 13s, the boundary portion B, the sections B1 and B2, and the welded portion 61 extend in the Y direction intersecting with the paper surface of FIG. 2. In other words, the Y direction is a direction that runs along the outer surfaces 11s and 13s as well as along the periphery 11b and the edge 13b. The Y direction is an example of a first direction.

The laser light L is irradiated in the Z direction toward section B1 of boundary portion B. That is, the irradiation direction I of the laser light L is the Z direction. Therefore, the welded portion 61 extends in the irradiation direction I from between the outer surface 11s and the outer surface 13s in the portion where the cross section of FIG. 2 is formed. The irradiation direction I is an example of the second direction. The irradiation direction I can also be referred to as the depth direction of the welded portion 61.

In the welding process, the laser light L irradiated from the laser welding device 100 (see FIG. 7) is swept in the Y direction in an irradiated state at least in the area where the cross section of FIG. 2 is formed, so that the welded portion 61 extends in the Y direction. In this embodiment, the periphery 11b, the edge 13b, and the edge of the side wall 14 have the same configuration as in FIG. 2 over their entire circumference. That is, the periphery 11b, the edge 13b, and the edge of the side wall 14 are seam-welded via the welded portion 61 over the entire circumference of the edge of the top wall 11, which serves as a lid for the opening of the side wall 13, and the storage chamber R is hermetically sealed at the welded portion 61.

In section B1 of boundary portion B, end face 11c and end face 13c face in the X direction. End face 11c faces in the X direction and spreads out crossing the X direction. In other words, end face 11c extends in the Y direction and the Z direction. On the other hand, end face 13c faces in the opposite direction to the X direction and spreads out crossing the X direction. In other words, end face 13c extends in the Y direction and the Z direction. End face 11c and end face 13c are in contact or face each other with a gap. Section B1 extends in the Y direction and in the Z direction toward storage chamber R. Section B1 is an example of an opposing section and a first opposing section. Also, in section B1, the Z direction is an example of a second direction.

In section B2, end face 11d and end face 13d face in the Z direction. End face 11d faces in the Z direction and spreads out crossing the Z direction. In other words, end face 11d extends in the X direction and the Y direction. On the other hand, end face 13d faces in the opposite direction to the Z direction and spreads out crossing the Z direction. In other words, end face 13d extends in the X direction and the Y direction. End face 11d and end face 13d are in contact with each other or face each other with a gap therebetween. Section B2 extends in the Y direction and also extends in the opposite direction of the X direction toward storage chamber R. Section B2 is an example of an opposing section and a second opposing section. Also, in section B2, the opposite direction to the X direction is an example of a third direction.

In addition, section B2 extends approximately along the X direction, which is the thickness direction of side wall 13, and the length T31 of section B2 in the X direction is equal to or greater than half the thickness T3 of side wall 13.

As described above, in this embodiment, the weld 61 that welds the top wall 11 (first member) and the side wall 13 (second member) extends in the Z direction (illumination direction I, second direction) between the outer surface 11s (first outer surface) and the outer surface 13s (second outer surface). In addition, the boundary portion B includes a section B1 and a section B2, with the section B1 (opposing section, first opposing section) extending in the Z direction (second direction) and the section B2 (opposing section, second opposing section) extending in the opposite direction to the X direction (third direction).

In this configuration, the laser light L is irradiated toward the section B1 approximately along the Z direction in which the section B1 extends. Therefore, compared to when the weld is formed to penetrate the top wall 11 or the side wall 13, the energy of the laser light L is more easily transmitted along the section B1, and the weld 61 can be formed with less energy. Accordingly, the occurrence of spatter can be suppressed. Furthermore, the section B2 located on the side of the storage chamber R from the section B1 in which the weld 61 is formed extends in the opposite direction to the X direction intersecting with the Z direction in which the section B1 extends. That is, before the weld 61 is formed, the boundary portion B is bent between the outer surface 11s and the outer surface 13s and the storage chamber R. Therefore, even if spatter occurs in the section B1 during the formation process of the weld 61, since the boundary portion B extends bent toward the storage chamber R, the spatter is less likely to enter the storage chamber R along the boundary portion B compared to when the boundary portion extends linearly. Therefore, this configuration can prevent sputters from affecting the optical components in the storage chamber R. When the sections B1 and B2 intersect at the boundary portion B, the extension direction of the welded portion 61 (Z direction) and the extension direction of the section B2 (opposite the X direction) will intersect.

Furthermore, as in this embodiment, in at least a portion of sections B1 and B2 (opposing sections), for example section B2, end face 11d, i.e., periphery 11b (first edge), and end face 13d, i.e., edge 13b (second edge), may be in contact with each other.

With this configuration, for example, the periphery 11b and the end edge 13b can be configured to contact each other at the boundary portion B, so that sputters are less likely to enter the storage chamber R along the boundary portion B compared to a configuration in which the periphery 11b and the end edge 13b do not contact each other. Therefore, with this configuration, it is possible to further prevent sputters from affecting the optical components in the storage chamber R. In this case, the end faces 11d, 13d, which are the contacting parts, may be used as positioning parts for the top wall 11 and the side wall 13 in the Z direction. With this configuration, the configuration of the housing 10 can be simplified compared to a case in which the positioning parts are provided separately from the boundary portion B.

Furthermore, in the case where section B2 extends in the thickness direction (X direction) of side wall 13 as in this embodiment, the length T31 of section B2 in the thickness direction may be equal to or greater than half the thickness T3 of side wall 13.

In this case, the length of section B2 can be made longer than when the length of section B2 is less than half the thickness T3, making it even more difficult for sputters to enter the storage chamber R along the boundary portion B. This makes it even more possible to prevent sputters from affecting the optical components inside the storage chamber R.

[First Modification]
Fig. 3 is a cross-sectional view of a welded structure 60B (60) of a first modified example of the first embodiment, taken at the same position as in Fig. 2. This modified example differs from the above embodiment in that the boundary portion B includes an intermediate chamber S. Except for the presence or absence of the intermediate chamber S, the welded structure 60B has the same configuration as the welded structure 60A of the embodiment.

The intermediate chamber S is a portion of the boundary portion B where the size h (height) of the gap between the periphery 11b and the end edge 13b is larger than in other portions. The intermediate chamber S is provided between the welded portion 61 or section B1 and the storage chamber R, and extends in the Y direction. In a cross section intersecting with the Y direction, it is preferable that the maximum value of the size h of the gap is 0.2 mm or more. Note that the intermediate chamber S may be located between the welded portion 61 and the storage chamber R, and is not limited to the position shown in FIG. 3.

With this configuration, even if spatter occurs in section B1 during the process of forming the welded portion 61, the spatter can be captured or contained in the intermediate chamber S, making it difficult for the spatter to enter the storage chamber R along the boundary portion B. Therefore, with this modified example, it is possible to further prevent the spatter from affecting the optical components in the storage chamber R.

[Second Modification]
Fig. 4 is a cross-sectional view of a welded structure 60C (60) according to a second modified example of the first embodiment, taken at the same position as in Fig. 2. This modified example differs from the above embodiment and the first modified example in that a boundary portion B is provided between the outer surface 11s and the outer surface 13s, which face in the X direction and are aligned substantially flush in the Z direction, and extends to the accommodation chamber R, and the boundary portion B is bent in a Z-shape.

In this modified example, boundary portion B has three sections B1, B21, and B22. Section B1 is adjacent to outer surfaces 11s and 13s. Section B21 is located closer to storage chamber R than section B1, and section B22 is located closer to storage chamber R than section B21.

In section B1 of boundary portion B, end face 11e and end face 13e face in the Z direction. End face 11e faces in the Z direction and spreads out crossing the Z direction. In other words, end face 11e extends in the X direction and the Y direction. On the other hand, end face 13e faces in the opposite direction to the Z direction and spreads out crossing the Z direction. In other words, end face 13e extends in the X direction and the Y direction. End face 11e and end face 13e are in contact or face each other with a gap. Section B1 extends in the Y direction and also extends in the opposite direction of the X direction toward storage chamber R. Section B1 is an example of an opposing section and a first opposing section. Also, in section B1, the opposite direction to the X direction is an example of a second direction.

In section B21, end face 11c and end face 13c face in the X direction. End face 11c faces in the X direction and spreads out crossing the X direction. In other words, end face 11c extends in the Y direction and Z direction. On the other hand, end face 13c faces in the opposite direction to the X direction and spreads out crossing the X direction. In other words, end face 13c extends in the Y direction and Z direction. End face 11c and end face 13c are in contact with each other or face each other with a gap therebetween. Section B21 extends in the Y direction and in the Z direction toward storage chamber R. Section B21 is an example of an opposing section and a second opposing section. Also, in section B21, the Z direction is an example of a third direction.

In addition, in this modified example, section B21 extends approximately along the Z direction, which is the thickness direction of top wall 11, and the length T11 of section B21 in the Z direction is equal to or greater than half the thickness T1 of top wall 11.

In section B22 of boundary portion B, end face 11d and end face 13d face in the Z direction. End face 11d faces in the Z direction and spreads out crossing the Z direction. In other words, end face 11d extends in the X direction and the Y direction. On the other hand, end face 13d faces in the opposite direction to the Z direction and spreads out crossing the Z direction. In other words, end face 13d extends in the X direction and the Y direction. End face 11d and end face 13d are in contact with each other or face each other with a gap therebetween. Section B22 extends in the Y direction and also extends in the opposite direction of the X direction toward storage chamber R. Section B22 is an example of an opposing section and a second opposing section. Also, in section B22, the opposite direction to the X direction is an example of a third direction.

According to the above-described present modified example, the boundary portion B includes a plurality of sections B21, B22 (opposing sections). The sections B21, B22 are arranged in series with each other between the welded portion 61 and the storage chamber R and extend in different directions from each other. With this configuration, it is even more difficult for spatter to enter the storage chamber R along the boundary portion B than when there is only one opposing section. Therefore, according to this modified example, it is possible to further suppress the effect of spatter on the optical components in the storage chamber R.

[Third Modification]
5 is a cross-sectional view of a welding structure 60D (60) of a third modified example of the first embodiment at the same position as in FIG. 2. The welding structure 60D of this modified example is provided with an intermediate chamber S similar to that of the first modified example. The intermediate chamber S is provided between the welded portion 61 or the section B1 and the accommodation chamber R, and extends in the Y direction. Note that the intermediate chamber S may be located between the welded portion 61 and the accommodation chamber R, and is not limited to the position shown in FIG. 5. The welding structure 60D has a similar configuration to the welding structure 60C of the second modified example, except for the presence or absence of the intermediate chamber S. Thus, according to this modified example, the same effect as that of the second modified example can be obtained, and the same effect as that of the first modified example due to the provision of the intermediate chamber S can be obtained.

[Fourth Modification]
6 is a cross-sectional view of a welded structure 60E (60) of a fourth modified example of the first embodiment at the same position as in FIG. 2. In this modified example, as in the second and third modified examples, a boundary portion B is provided between the outer surface 11s and the outer surface 13s that face the X direction and are aligned substantially flush in the Z direction to the storage chamber R, and the boundary portion B is bent in a Z-shape. However, in this modified example, the section B21 extends in the opposite direction to the Z direction from the section B1 toward the storage chamber R, and the section B22 extends in the opposite direction to the X direction from the end of the section B21 in the opposite direction in the Z direction toward the storage chamber R. According to this modified example, the same effect as the second modified example having the boundary portion B bent in a Z-shape can be obtained.

In addition, in this modified example, the end surface 11d is provided as the bottom surface of a recess 11g provided in the top wall 11. The recess 11g extends in the Y direction and can also be called a groove. In this case, the side surface on the opposite side in the X direction of the recess 11g becomes a wall facing section B22 of the boundary portion B with a gap therebetween. This makes it possible to further prevent sputter from entering the storage chamber R, and thus further prevent sputter from affecting the optical components in the storage chamber R. However, the groove-shaped recess 11g is not essential and may be provided as needed.

[Second embodiment]
[Laser welding equipment]
Fig. 7 is a diagram showing a schematic configuration of a laser welding device 100 of the second embodiment. As shown in Fig. 7, the laser welding device 100 includes a laser device 110, an optical head 120, and an optical fiber 130. The laser welding device 100 can provide the welded structure 60 of the first embodiment and each of the modified examples.

The laser welding device 100 irradiates a laser beam L onto the surface Wa of the housing 10, which is the object W to be laser welded. The energy of the laser beam L causes the object W to partially melt, and then cool and solidify, thereby welding the object W and forming a welded structure 60. The object W has multiple members such as the top wall 11 and side walls 13 of the first embodiment described above, and the multiple members are joined by laser welding. Note that in the first embodiment and its first to fourth modified examples, the outer surfaces 11s, 13s are examples of the surface Wa.

The laser device 110 has a laser oscillator and is configured to output, for example, a single-mode laser beam with a power of several kW. The laser device 110 may have, for example, multiple semiconductor laser elements inside and be configured to output a multi-mode laser beam with a power of several kW as the total output of the multiple semiconductor laser elements. The laser device 110 may also have various laser light sources such as a fiber laser, a YAG laser, a disk laser, etc. The laser device 110 outputs, for example, a laser beam with a wavelength of 400 nm or more and 1200 nm or less.

The optical fiber 130 optically connects the laser device 110 and the optical head 120. In other words, the optical fiber 130 guides the laser light output from the laser device 110 to the optical head 120. When the laser device 110 outputs a single mode laser light, the optical fiber 130 is configured to propagate the single mode laser light. In this case, the ^M2 beam quality of the single mode laser light is set to 1.3 or less. The ^M2 beam quality may also be referred to as an M2 factor.

The optical head 120 is an optical device that emits the laser light input from the laser device 110, in other words, irradiates the target object W. The optical head 120 has a collimator lens 121, a condenser lens 122, and a DOE 125 (diffractive optical element).

The collimating lenses 121 each collimate the laser light input via the optical fiber 130. The collimated laser light becomes parallel light.

A DOE 125 is provided between the collimator lens 121 and the condenser lens 122. The DOE 125 will be described later.

The focusing lens 122 focuses the parallel laser light coming from the DOE 125 and irradiates the laser light L (output light) onto the object W.

The drive mechanism (not shown) changes the relative position between the object W and the optical head 120 by moving at least one of the object W and the optical head 120. The drive mechanism has, for example, a rotation mechanism such as a motor, a speed reduction mechanism that reduces the rotation output of the rotation mechanism, and a motion conversion mechanism that converts the rotation reduced by the speed reduction mechanism into linear motion. The drive mechanism can translate the object W and the optical head 120 relatively in three mutually orthogonal directions, and rotate them relatively around the rotation axis Ax.

The controller (not shown) can control the drive mechanism so that the relative position of the optical head 120 in each direction with respect to the object W changes. The drive mechanism can also change (switch) the object W to be laser welded among the multiple objects W supported by the support mechanism (not shown). The drive mechanism can also change the irradiation position of the laser light L on the object W. The drive mechanism can also be used to change the irradiation point in conjunction with changing the irradiation direction I of the laser light with respect to the object W. Furthermore, the drive mechanism can change the irradiation position while the laser light L is being irradiated onto the surface of the object W. In other words, the drive mechanism can sweep the laser light L on the surface of the object W. This allows seam welding of the welded portion 61 to be realized.

The optical head 120 may also have a galvanometer scanner (not shown) with multiple mirrors. In this case, the controller may control the galvanometer scanner so that the laser light L is swept over the surface of the object W.

As described above, the optical head 120 has a DOE 125. It shapes the shape of the laser light beam (hereinafter referred to as the beam shape). FIG. 8 is an explanatory diagram showing the concept of the principle of the DOE 125. As conceptually illustrated in FIG. 8, the DOE 125 has a configuration in which, for example, multiple diffraction gratings 125a with different periods are superimposed. The DOE 125 can shape the beam shape by bending the parallel light in a direction influenced by each diffraction grating 125a or by superimposing the light. The DOE 125 can also be called a beam shaper.

[Beam (spot) shape]
The DOE 125 splits the collimated laser light into a plurality of beams. FIGS. 9 to 11 are diagrams showing examples of beams of laser light L formed on the surface Wa of the object W. In FIGS. 9 to 11, for simplicity, the beam Lb1 is shown by a solid line and the beam Lb2 is shown by a dashed line. The optical head 120 can output laser light including a plurality of beams in various arrangements by replacing the DOE 125. The DOE 125 is an example of a beam shaper.

The DOE 125 splits the laser light into multiple beams. The multiple split beams include at least one beam Lb1 and at least one beam Lb2. Beam Lb2 has a lower power density than beam Lb1. Beam Lb1 is an example of a main beam, and beam Lb2 is an example of a sub beam. Beam Lb1 forms a main power region, and beam Lb2 forms a sub power region.

In the example of FIG. 9, a spot of one beam Lb1 and a spot of beam Lb2 that is wider than beam Lb1 are formed on surface Wa. Beam Lb1 and the outer edge Lb1a of beam Lb1 are located inside the outer edge Lb2a of beam Lb2. Note that beam Lb1 and beam Lb2 may be arranged concentrically or eccentrically. Furthermore, outer edge Lb1a may be inscribed in outer edge Lb2a or may be partially located outside outer edge Lb2a.

In the example of FIG. 10, a spot of one beam Lb1 and multiple spots of beams b2 surrounding the beam Lb1 are formed on the surface Wa. The beams b2 are arranged in a substantially circular ring shape. The beam b2 is an example of a sub-beam, and a sub-power region is formed by the multiple beams b2.

In the example of FIG. 11, a spot of one beam Lb1 and spots of multiple beams b2 surrounding the beam Lb1 are formed on the surface Wa. However, the beams b2 are arranged in a substantially rectangular shape, that is, along the sides of a virtual rectangle. The beam b2 is an example of a sub-beam, and a sub-power region is formed by the multiple beams b2.

In each of the laser beams L in Figs. 9 to 11, at least a part of the beam b2 (secondary power region) is disposed around the beam Lb1 (main power region). The laser beam L is shaped so that at least a part of the beam Lb2 is positioned forward of the beam Lb1 in the sweep direction. Research by the inventors has revealed that when sweeping is performed while irradiating such a laser beam L, the occurrence of spatters and blowholes can be suppressed compared to when sweeping is performed while irradiating a laser beam having a single beam. This is because the surface Wa is preheated by at least a part of the beam Lb2 before the molten pool is formed, and the molten pool that becomes in a flowing state is more stable compared to when the surface Wa is rapidly heated without being preheated by a single beam. Therefore, it is preferable that the welding structure 60 (60A to 60E) disclosed in the first embodiment and its modified example has a structure including the bent boundary portion B as described above and has a linear weld 61 formed by sweeping while irradiating the laser beam L including the beams Lb1 and Lb2.

Although the above describes the embodiments and variations of the present invention, the above embodiments and variations are merely examples and are not intended to limit the scope of the invention. The above embodiments and variations can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the specifications of each configuration, shape, etc. (structure, type, direction, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be modified as appropriate.

For example, the optical device may include, as optical components, a semiconductor laser element, a light receiving element, a semiconductor modulator, a semiconductor optical amplifier, etc. The optical device may include, as optical components, at least one of the semiconductor laser element, the light receiving element, the semiconductor modulator, and the semiconductor optical amplifier.

1...Optical device 10...Housing 11...Top wall (first member)
11b...periphery (first edge)
11c... End face 11d... End face 11e... End face 11g... Recessed portion 11s... Outer surface (first outer surface)
12... bottom wall 13... side wall (second member)
13b...Edge (second edge)
13c... End surface 13d... End surface 13e... End surface 13s... Outer surface (first outer surface)
14...Side wall (second member)
15...optical window 16...feed-through 20...temperature adjustment device 20a...upper surface 20b...lower surface 21U...upper substrate 21L...lower substrate 21a...upper surface 21b...lower surface 22...thermoelectric element 30...flexible printed wiring board 41...light-emitting element 42...lens 43...carrier 51...optical isolator 51a...magnet 51b...optical element section 52...beam splitter 53...light-receiving element 60, 60A to 60E...welded structure 61...welded part 100...laser welding device 110...laser device 120...optical head 121...collimating lens 122...condensing lens 125...DOE
125a...diffraction grating 130...optical fiber A...corner Ax...rotation axis B...boundary portion B1...section (opposing section, first opposing section)
B2, B21, B22...sections (opposing section, second opposing section)
b2...Beam I...Irradiation direction (second direction)
L...Laser light Lb1...Beam (main beam)
Lb1a: Outer edge Lb2: Beam (sub-beam)
Lb2a...outer edge R...storage chamber S...intermediate chamber T1, T3...thickness T11, T31...length W...object Wa...surface X...direction (opposite direction to the third direction, opposite direction to the second direction)
Y direction (first direction)
Z...direction (second direction, third direction)

Claims (13)

A housing for an optical device that forms a chamber for accommodating an optical component,
a plate-like first member having a first outer surface that becomes an outer surface of the housing and a first edge;
a plate-shaped second member having a second outer surface that is an outer surface of the housing and a second edge that extends along the first edge;
a linear weld portion formed by welding a portion between the first outer surface and the second outer surface of a boundary portion between the first edge and the second edge;
Equipped with
The weld portion extends from between the first outer surface and the second outer surface in a second direction intersecting a first direction along the first outer surface and the first edge, and
the boundary portion includes an opposing section extending in a third direction intersecting the first direction and the second direction as an opposing section in which the first edge and the second edge face or contact with each other with a gap between the welded portion and the accommodation chamber, and includes an intermediate chamber in which the size of the gap between the first edge and the second edge at the boundary portion is larger than that of other portions,
The intermediate chamber is disposed at a position between the welded portion and the accommodating chamber, away from the welded portion and from the accommodating chamber . The housing for the optical device according to claim 1 , wherein a maximum value of the size of the gap in a cross section intersecting with the first direction is 0.2 mm or more. The housing for the optical device according to claim 1 or 2 , wherein the boundary portion includes, as the opposing sections, a plurality of opposing sections arranged in series between the welded portion and the storage chamber and extending in different directions from each other. The housing for an optical device according to claim 1 , wherein the first edge and the second edge are in contact with each other in at least a portion of the opposing section. A housing for an optical device described in any one of claims 1 to 4, wherein the boundary portion includes an opposing section that extends approximately along the thickness direction of one of the first and second members for a length equal to or greater than half the thickness of the one member. 6. The housing for an optical device according to claim 1, wherein a deviation between the first outer surface and the second outer surface in the second direction is 0.1 mm or less. The housing for an optical device according to claim 1 , wherein the welded portion is provided circumferentially. The housing for an optical device according to claim 1 , wherein the chamber is hermetically sealed at the welded portion. the first member is a member constituting a lid of the housing that closes an opening in a peripheral wall of the housing,
The second member is a member that constitutes the peripheral wall,
the first edge is a peripheral edge of the lid;
The housing for an optical device according to claim 1 , wherein the second edge is a peripheral edge of the peripheral wall extending along the first edge. A housing for an optical device according to any one of claims 1 to 9 ;
An optical component accommodated in the accommodation chamber;
An optical device comprising: A housing for an optical device that forms a chamber for accommodating an optical component,
a plate-like first member having a first outer surface that becomes an outer surface of the housing and a first edge;
a plate-shaped second member having a second outer surface that is an outer surface of the housing and a second edge that extends along the first edge;
a linear weld portion formed by welding a portion between the first outer surface and the second outer surface of a boundary portion between the first edge and the second edge;
Equipped with
The weld portion extends from between the first outer surface and the second outer surface in a second direction intersecting a first direction along the first outer surface and the first edge, and
the boundary portion includes an opposing section extending in a third direction intersecting the first direction and the second direction as an opposing section in which the first edge and the second edge face or contact with each other with a gap between the welded portion and the accommodation chamber, and includes an intermediate chamber in which the size of the gap between the first edge and the second edge at the boundary portion is larger than that of other portions,
the intermediate chamber is disposed at a position between the welding portion and the accommodation chamber, the intermediate chamber being spaced apart from the welding portion and from the accommodation chamber; and the laser welding device irradiates the housing with a laser beam to weld the first edge and the second edge,
The laser welding apparatus includes:
A laser oscillator;
an optical head that emits a laser beam from the laser oscillator;
Equipped with
A laser welding device that forms the welded portion by irradiating and sweeping the laser light from the optical head toward a portion between the first outer surface and the second outer surface . The laser welding apparatus according to claim 11 , further comprising a beam shaper for shaping the laser light beam. A housing for an optical device that forms a chamber for accommodating an optical component,
a plate-like first member having a first outer surface that becomes an outer surface of the housing and a first edge;
a plate-shaped second member having a second outer surface that is an outer surface of the housing and a second edge that extends along the first edge;
a linear weld portion formed by welding a portion between the first outer surface and the second outer surface of a boundary portion between the first edge and the second edge;
Equipped with
The weld portion extends from between the first outer surface and the second outer surface in a second direction intersecting a first direction along the first outer surface and the first edge, and
the boundary portion includes an opposing section extending in a third direction intersecting the first direction and the second direction as an opposing section in which the first edge and the second edge face or contact with each other with a gap between the welded portion and the accommodation chamber, and includes an intermediate chamber in which the size of the gap between the first edge and the second edge at the boundary portion is larger than that of other portions,
The intermediate chamber is disposed at a position between the welded portion and the accommodation chamber, the intermediate chamber being spaced apart from the welded portion and from the accommodation chamber. The laser welding method includes irradiating a laser beam to the housing to weld the first edge and the second edge ,
The laser welding method includes forming the welded portion by irradiating and sweeping the laser light toward a portion between the first outer surface and the second outer surface .

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