JP2021015849A - Optical module and stem part - Google Patents

Abstract

To provide an optical module that imparts excellent heat dissipation performance to a package in which a semiconductor laser is accommodated.SOLUTION: An optical module includes a cap part containing a cap base and an optical window, a stem part containing an inner surface, an outer surface on an opposite side of the inner surface, a through-hole extending from the inner surface to the outer surface, a stem base having a first cavity provided on the inner surface, and a lead terminal supported by the stem base, and a subassembly containing a semiconductor laser and a heat sink. The stem part and the cap part are arranged in a first axis direction, and the subassembly and the optical window are arranged in the first axis direction. The lead terminal passes through the through-hole in the first axis direction, and the stem base has a surface defining the first cavity. The surface of the first cavity contains a side surface extending in the first axis direction and a bottom, and the subassembly is supported by the surface of the first cavity.SELECTED DRAWING: Figure 1

Description

The present invention relates to optical modules and stem components.

Patent Document 1 discloses an optical module.

Japanese Unexamined Patent Publication No. 5-175614

The optical module houses the semiconductor laser in a package, eg, a package that includes stem and cap components. A semiconductor laser generates heat during operation, and this heat is released to the outside through a package. In particular, a laser that requires a large amount of power for laser oscillation, for example, a quantum cascade laser, requires a high heat dissipation capability in the package.

One aspect of the present invention is to provide an optical module that imparts good heat dissipation to a package containing a semiconductor laser. Another aspect of the present invention is to provide a stem component that provides good heat dissipation to a package that houses a semiconductor device.

The optical module according to one aspect of the present invention is provided on a cap component including a cap base and an optical window, an inner surface, an outer surface on the opposite side of the inner surface, a through hole extending from the inner surface to the outer surface, and the inner surface. A stem base having a first cavity, a stem component including a lead terminal supported by the stem base, and a subassembly including a semiconductor laser and a heat sink are provided, and the stem component and the cap component are the first shaft. The subassembly and the optical window are arranged in the direction of the first axis, the lead terminal passes through the through hole in the direction of the first axis, and the stem base is the stem base. It has a surface defining a first cavity, the surface of the first cavity includes a side surface and a bottom extending in the direction of the first axis, and the subassembly is by the surface of the first cavity. Be supported.

Stem components according to another aspect of the present invention include a stem base having an inner surface, an outer surface opposite to the inner surface, a through hole extending from the inner surface to the outer surface, and a first cavity provided on the inner surface. A lead terminal supported by the stem base, the lead terminal passes through the through hole in the direction of the first axis, and the stem base has a surface defining the first cavity. The surface of the first cavity includes a side surface and a bottom surface extending in the direction of the first axis.

The above objectives and other objectives, features, and advantages of the present invention will be more easily apparent from the following detailed description of preferred embodiments of the invention, which proceed with reference to the accompanying drawings.

As described above, according to one aspect of the present invention, there is provided an optical module that imparts good heat dissipation to a package containing a semiconductor laser. According to another aspect of the present invention, there is provided a stem component that imparts good heat dissipation to a package containing a semiconductor element.

FIG. 1 is a drawing showing components of an optical module according to one aspect of the embodiment. FIG. 2 is a drawing showing a partially broken optical module shown in FIG. FIG. 3 is a drawing showing a cross section taken along lines III-III shown in FIG. FIG. 4 is a drawing showing components of an optical module according to another aspect of the embodiment. FIG. 5 is a drawing showing a partially broken optical module shown in FIG. Part (a) of FIG. 6 is a top view schematically showing a subassembly for the optical module according to the present embodiment. Part (b) of FIG. 6 is a front view schematically showing a subassembly for the optical module according to the present embodiment. Part (c) of FIG. 6 is a front view schematically showing a subassembly for the optical module according to the present embodiment. Part (a) of FIG. 7 is a drawing schematically showing a main step in the method for manufacturing an optical module according to the present embodiment. Part (b) of FIG. 7 is a drawing showing a cross section taken along the line VIIb-VIIb shown in part (a) of FIG. Part (a) of FIG. 8 is a drawing schematically showing a main step in the method for manufacturing an optical module according to the present embodiment. Part (b) of FIG. 8 is a drawing showing a cross section taken along the line VIIIb-VIIIb shown in part (a) of FIG. (A) and (b) of FIG. 9 are drawings schematically showing the main steps in the method for manufacturing the optical module according to the present embodiment, respectively. Part (a) of FIG. 10 is a drawing schematically showing a main step in the method for manufacturing an optical module according to the present embodiment. Part (b) of FIG. 10 is a drawing showing a cross section taken along the line Xb-Xb shown in part (a) of FIG. Part (a) of FIG. 11 is a drawing schematically showing a main step in the method for manufacturing an optical module according to the present embodiment. Part (b) of FIG. 11 is a drawing showing a cross section taken along the line XIb-XIb shown in part (a) of FIG.

Some specific examples will be described.

The optical module according to the specific example includes (a) a cap component including a cap base and an optical window, (b) an inner surface, an outer surface on the opposite side of the inner surface, a through hole extending from the inner surface to the outer surface, and the inner surface. A stem base having a first cavity provided in the stem base, a stem component including a lead terminal supported by the stem base, and (c) a subassembly including a semiconductor laser and a heat sink, the stem component and the cap. The parts are arranged in the direction of the first axis, the subassembly and the optical window are arranged in the direction of the first axis, and the lead terminal passes through the through hole in the direction of the first axis. The stem base has a surface defining the first cavity, the surface of the first cavity includes a side surface and a bottom extending in the direction of the first axis, and the subassembly is the first. It is supported by the surface of one cavity.

According to the optical module, the stem base of the stem component is provided with a side extending in the direction of the first axis. This side surface forms a first cavity extending in the direction of the first axis, the first cavity supporting the subassembly by its surface. This support allows the subassembly semiconductor laser to dissipate heat to the stem component through the surface of the subassembly heat sink and first cavity.

Also, the sides of the stem base close around the first axis to define an area of the first cavity that accepts the subassembly. The stem component with the first cavity allows the subassembly and optical windows to be aligned in the direction of the first axis. Further, according to the stem base having a side surface in the first cavity, in addition to heat propagation in the direction of the first axis in the stem base, heat is transmitted in a direction intersecting the first axis, for example, in the circumferential direction along the side surface. Allows propagation.

In the optical module according to the specific example, the semiconductor laser includes a quantum cascade laser.

According to the optical module, the quantum cascade laser dissipates heat to the stem component through the surface of the heat sink and the first cavity of the subassembly and is cooled.

In the optical module according to the specific example, the optical window can transmit light having a wavelength of 3 micrometers or more.

According to the optical module, the optical window allows the light from the quantum cascade laser to be provided to the outside.

In the optical module according to the specific example, the cap base includes a ceiling portion and a side wall portion that support the optical window, and the cap component and the stem component are such that the stem base of the stem component is the cap component. A second cavity is provided on the stem base to support one end of the side wall and airtightly seals the subassembly.

According to the optical module, the first cavity can be provided in the second cavity that hermetically seals the subassembly.

In the optical module according to the specific example, the subassembly includes a submount mounted on the heat sink, and the submount includes a first surface on which the semiconductor laser is mounted and a second surface opposite the first surface. Having a surface, the optical module further comprises an adhesive that secures the subassembly to the side surface of the first cavity.

According to the optical module, the first cavity can support the heat sink on the second surface of the heat sink so as to accommodate part or all of the subassembly, specifically a part of the subassembly (specifically, The first cavity, which houses part or all of the semiconductor laser, supports part of the second surface of the submount. Alternatively, the first cavity, which houses the entire subassembly (specifically, the entire semiconductor laser), supports the entire second surface of the submount so as to accommodate the entire subassembly.

In the optical module according to the specific example, the semiconductor laser has a first end face optically coupled to the optical window and a second end face opposite to the first end face, and the second end face of the semiconductor laser. The end face is located in the first cavity.

According to the optical module, the first cavity can accommodate the subassembly so that the second end face of the semiconductor laser is located in the first cavity. The heat sink of the subassembly transfers heat from the semiconductor laser to the stem base in the first cavity.

The stem component according to the specific example is used for an optical module, and is provided with (a) an inner surface, an outer surface on the opposite side of the inner surface, a through hole extending from the inner surface to the outer surface, and a first surface provided on the inner surface. A stem base having a cavity and (b) a lead terminal supported by the stem base are provided, the lead terminal passes through the through hole in the direction of the first axis, and the stem base is the first. It has a surface that defines the cavity, and the surface of the first cavity includes a side surface and a bottom surface extending in the direction of the first axis.

According to the stem component, the sides and bottom of the stem base define the first cavity. The sides of the stem base extend in the direction of the first axis so that the subassembly can be mounted.

In the stem component according to the specific example, the stem base has a thickness smaller than the depth of the first cavity on the bottom surface of the first cavity.

According to the stem component, the first cavity is provided with a depth greater than the thickness of the bottom surface of the first cavity to facilitate accommodation of the subassembly in the first cavity.

The findings of the present invention can be easily understood by referring to the accompanying drawings shown as examples and considering the following detailed description. Subsequently, an embodiment relating to the optical module and the stem component will be described with reference to the accompanying drawings. When possible, the same parts are designated by the same reference numerals.

FIG. 1 is a drawing showing components of an optical module according to an embodiment. FIG. 2 is a drawing showing a partially broken optical module according to an embodiment. FIG. 3 is a drawing showing a cross section taken along lines III-III shown in FIG. FIG. 4 is a drawing showing components of an optical module according to an embodiment. FIG. 5 is a drawing showing a partially broken optical module according to an embodiment.

With reference to FIGS. 1, 2, 4 and 5, the optical module 11 includes a stem component 17.

The stem component 17 includes a stem base 19 and one or more lead terminals 21 (lead terminals 21a and lead terminals 21b in this embodiment). The stem base 19 has a first cavity 20. The lead terminal 21 is supported by the stem base 19.

The stem base 19 has a surface 19a that defines the first cavity 20.
The surface 19a of the stem base 19 includes a side surface 19b extending in the direction of the first axis Ax1 and a bottom surface 19c connected to the lower edge of the side surface 19b. The side surfaces 19b and bottom surface 19c of the surface 19a of the stem base 19 define the cavity in this embodiment and provide depth to the first cavity. Further, the stem base 19 has an inner surface 19f and an outer surface 19g arranged in the direction of the first axis Ax1, and the inner surface 19f is on the opposite side of the outer surface 19g. The stem base 19 has a through hole 19d for the lead terminal 21. The through hole 19d extends from the inner surface 19f to the outer surface 19g.

With reference to FIGS. 1, 2, 4 and 5, the optical module 11 further comprises a subassembly 13. The subassembly 13 includes a semiconductor laser 27 and a submount 29 and is provided on the stem component 17. The submount 29 mounts the semiconductor laser 27. The subassembly 13 is supported by the surface 19a of the first cavity 20. The side surface 19b of the first cavity 20 is closed so as to surround the subassembly 13.

According to the optical module 11, the stem base 19 is provided with a side surface 19b extending in the direction of the first axis Ax1. The side surface 19b forms a first cavity 20 extending in the direction of the first axis Ax1, and the first cavity 20 supports the subassembly 13 by its surface 19a. According to this support, the heat from the semiconductor laser 27 of the subassembly 13 is transferred to the stem component 17 through the surfaces of the submount 29 and the first cavity 20 of the subassembly 13, and the semiconductor laser 27 can be dissipated. Become.

The optical module 11 may further include a cap component 15. The cap component 15 and the stem component 17 are arranged in the direction of the first axis Ax1, and the stem component 17 supports one end of the cap component 15.

Specifically, the cap component 15 includes a cap base 23 and an optical window 25. The cap base 23 includes a ceiling portion 23a and a side wall portion 23b. The ceiling portion 23a has an opening 23c and supports an optical window 25 aligned with the opening 23c. The side wall portion 23b extends from the ceiling portion 23a in the direction of the first axis Ax1 so as to separate the opening 23c from one end of the side wall portion 23b. The subassembly 13 and the optical window 25 are arranged in the direction of the first axis Ax1.

Further, the side surface 19b surrounding the first axis Ax1 defines the position of the first cavity 20 for receiving the subassembly 13, and the subassembly 13 (specifically, the semiconductor laser 27 of the subassembly 13) and the optical window 25 are provided. It is possible to arrange in the direction of the first axis Ax1. The semiconductor laser 27 is optically coupled to the optical window 25. Further, the side surface 19b enables heat propagation in the stem base 19 in the direction of the first axis Ax1 and in the direction intersecting the first axis Ax1, for example, in the circumferential direction along the side surface. To do.

Specifically, the stem base 19 has a side surface 19h that connects the inner surface 19f to the outer surface 19g. The stem base 19 has a recess 19e defining the first cavity 20 on the inner surface 19f. The recess 19e has a depth of, for example, 2000 micrometers or more.

Further, the stem base 19 is provided with a through hole 19d. The through hole 19d extends in the direction from the inner surface 19f to the outer surface 19g. The stem component 17 has a sealing material 18 provided in the through hole 19d, and the sealing material 18 holds the lead terminal 21. The lead terminal 21 passes through the through hole 19d in the direction of the first axis Ax1.

In this embodiment, the semiconductor laser 27 can include, for example, a quantum cascade laser. According to the optical module 11, the quantum cascade laser makes it possible to dissipate heat to the stem component 17 in the first cavity 20 via the submount 29 and the side surface 19b of the stem base 19. Quantum cascade lasers can generate light with wavelengths of, for example, 4 to 10 micrometers.

The optical window 25 can contain, for example, zinc selenium (ZnSe), and can transmit light having a wavelength of, for example, 3 micrometers or more. The optical window 25 allows the light from the quantum cascade laser to be provided to the outside.

The cap component 15 is provided on the stem base 19 so that the stem base 19 of the stem component 17 supports one end of the side wall portion 23b of the cap component 15 (cap base 23), and airtightly seals the subassembly 13. The second cavity 30 is defined. According to the optical module 11, the first cavity 20 can be provided in the second cavity 30 that airtightly seals the subassembly 13.

The submount 29 of the subassembly 13 has a first surface 29a and a second surface 29b, the first surface 29a being on the opposite side of the second surface 29b. The base material of the submount 29 can include, for example, copper tungsten (CuW). The submount 29 mounts the semiconductor laser 27 on the metal film 29c on the first surface 29a.

Specifically, the subassembly 13 may further include a heat sink 33, which has a mounting surface 33a and a back surface 33b opposite the mounting surface 33a. The mounting surface 33a may include an insulating material. The heat sink 33 mounts the sub mount 29 on the mounting surface 33a. The heat sink 33 may contain, for example, copper (Cu).

The optical module 11 further includes an adhesive 31 that fixes the heat sink 33 to the side surface 19b of the first cavity 20. The adhesive 31 contains, for example, gold tin (AuSn). The first cavity 20 houses a part or all of the subassembly 13.

According to the optical module 11, the subassembly 13 can be supported on the back surface 33b of the heat sink 33 so that the first cavity 20 accommodates part or all of the subassembly 13, specifically one of the subassembly 13. The first cavity 20 accommodating the portion (specifically, a part of the semiconductor laser 27) supports a part of the back surface 33b of the heat sink 33 on the side surface 19b so as to accommodate a part of the subassembly 13. Can be done. Alternatively, the first cavity 20 accommodating the entire subassembly 13 (specifically, the entire semiconductor laser 27) has the entire back surface 33b of the heat sink 33 on the side surface 19b so as to accommodate the entire subassembly 13. Can be supported.

Part (a) of FIG. 6 is a top view schematically showing a subassembly for the optical module according to the present embodiment. The subassembly 13 further includes a connecting component 34, which is fixed to the mounting surface 33a of the heat sink 33. The connecting component 34 includes a conductive first arm 34a and a second arm 34b, and the first arm 34a and the second arm 34b each project from the front edge of the heat sink 33 in the direction of the first axis Ax1. It is a department.

As shown in FIGS. 2 and 5, in the subassembly 13 positioned in the first cavity 20, at least a part of the protrusions of the first arm 34a and the second arm 34b protrudes from the upper edge of the first cavity 20. ing. This protrusion facilitates the connection of the semiconductor laser 27 of the subassembly 13 housed in the first cavity 20 to the lead terminal 21.

In this embodiment, the connecting component 34 includes a first bar 35 and a second bar 37 separated from each other, and the first bar 35 and the second bar 37 are fixed to the mounting surface 33a of the heat sink 33. The first bar 35 and the second bar 37 extend in the direction of the first axis Ax1 on the mounting surface 33a of the heat sink 33, as shown in FIGS. 2, 3 and 5. The first bar 35 and the second bar 37 are conductive materials such as metal and can have a rod-like shape.

In this embodiment, the submount 29 is provided between the first bar 35 and the second bar 37 on the mounting surface 33a of the heat sink 33. The semiconductor laser 27 on the submount 29 is connected to the first bar 35 and the second bar 37 via a conductive thin wire such as a gold wire.

Each of the first bar 35 and the second bar 37 has a front end away from the front edge of the submount 29 and a rear end away from the rear edge of the heat sink 33. The first bar 35 and the second bar 37 project from the front edge of the heat sink 33, and these projecting portions serve as the conductive first arm 34a and second arm 34b of the connecting component 34. The first bar 35 and the second bar 37 are connected to, for example, the anode of the semiconductor laser 27 and the cathode of the semiconductor laser 27, respectively.

Referring to FIG. 3, the semiconductor laser 27 has a first end face 27a and a second end face 27b, and the second end face 27b is on the opposite side of the first end face 27a. The semiconductor laser 27 emits laser light from the first end surface 27a, and the first end surface 27a is optically coupled to the optical window 25 as shown in FIGS. 2 and 5. The semiconductor laser 27 can have a highly reflective structure such as a metal film on the second end surface 27b.

The semiconductor laser 27 has a support 28a and a laminate 28b. The support 28a mounts the laminated body 28b. The laminate 28b has an upper semiconductor region 28c including an upper clad layer, a core layer 28d, and a lower semiconductor region 28e including a lower clad layer. The core layer 28d is provided between the upper semiconductor region 28c and the lower semiconductor region 28e, and in this embodiment, a quantum cascade is generated.

(B) and (c) of FIG. 6 are front views schematically showing subassemblies for the optical module according to the present embodiment. The back surface 33b of the heat sink 33 can be substantially flat, or even if it projects in the direction from the mounting surface 33a to the back surface 33b so as to draw a convex curve in a cross section intersecting the first axis Ax1. Good.

With reference to FIGS. 1, 2, 3, 4, and 5, the second end surface 27b of the semiconductor laser 27 is located in the first cavity 20. According to the optical module 11, the first cavity 20 accommodates the subassembly 13 so that the second end surface 27b of the semiconductor laser 27 is located in the first cavity 20. This accommodation makes it possible to transfer heat from the semiconductor laser 27 to the stem base 19 via the submount 29, the heat sink 33 and the side surface 19b of the first cavity 20.

In this embodiment, the first end surface 27a of the semiconductor laser 27 is also located in the first cavity 20.

According to the optical module 11, the first cavity 20 can accommodate the subassembly 13 so that the first end surface 27a of the semiconductor laser 27 is located in the first cavity 20. According to this accommodation, the heat from the semiconductor laser 27 is transferred to the side surface 19b of the first cavity 20 through the entire back surface 33b of the heat sink 33 in the first cavity 20, and this heat is spread to the stem base 19.

As shown in FIGS. 1, 2 and 3, the through hole 19d of the stem base 19 can penetrate from the inner surface 19f to the outer surface 19g so as to be connected to the first cavity 20. The through hole 19d is positioned on the inner surface 19f and the outer surface 19g so that the through hole 19d is connected to the first cavity 20, and the bottom surface 19c of the first cavity 20 reaches the edge of the through hole 19d. The lead terminal 21 is held by a sealing material 18 that fills a short hole connecting the bottom surface 19c (inner surface 19f) and the outer surface 19g. The lead terminal 21 protrudes from the level of the bottom surface 19c and has a tip higher than the level of the upper edge of the first cavity 20.

Alternatively, as shown in FIGS. 4 and 5, the through hole 19d of the stem base 19 can penetrate from the inner surface 19f to the outer surface 19g of the stem base 19 so as to be separated from the first cavity 20. The through hole 19d is positioned on the inner surface 19f and the outer surface 19g so as to be separated from the through hole 19d, and the bottom surface 19c of the first cavity 20 is terminated at the lower edge of the side surface 19b of the first cavity 20. The lead terminal 21 is held by a sealing material 18 that fills a long hole connecting the inner surface 19f and the outer surface 19g. The lead terminal 21 protrudes from the level of the inner surface 19f and has a tip higher than the level of the upper edge of the first cavity 20.

As shown in FIGS. 1 to 5, the connecting component 34 of the subassembly 13 has a tip higher than the upper edge of the first cavity 20 and is connected to the lead terminal 21 via a conductor.

Referring to FIG. 3, the stem base 19 includes a plate-shaped portion 39 and a wall portion 41. The plate-shaped portion 39 extends along a reference plane intersecting the first axis Ax1 so that the stem base 19 can provide the bottom surface 19c of the first cavity 20. The wall portion 41 projects from the plate-shaped portion 39 in the direction of the first axis Ax1 so that the side surface 19b of the first cavity 20 can be provided to the stem base 19. The wall portion 41 is raised with reference to the bottom surface 19c of the first cavity 20, and the stem base 19 has a thickness larger than the thickness of the bottom surface 19c of the first cavity 20 at the wall portion 41. The wall portion 41 has a height of 2000 micrometers or more with respect to the bottom surface 19c of the first cavity 20.

The wall portion 41 has an inner side surface 41b having a side surface 19b of the first cavity 20 and an outer surface 41c. The inner surface 41b and the outer surface 41c extend in the direction of the first axis Ax1. The side surface 19h of the stem base 19 includes an outer surface 41c. In this embodiment, the wall portion 41 extends in the radial direction of the stem base 19 from the side surface 19b of the first cavity 20 to the side surface 19h of the stem base 19, and the outer surface of the wall portion 41 extends from the side surface 19h of the stem base 19 to the side surface 19h of the stem base 19. 41c is provided.

According to the optical module 11, the wall portion 41 provides the upper surface 41a and the inner side surface 41b to the inner surface 19f so as to form the first cavity 20 into the stem base 19, and also provides the outer surface 41c to the side surface 19h. The wall portion 41 is provided so as to surround the first axis Ax1 and gives a low thermal resistance to the stem base 19.

According to the optical module 11, the wall portion 41 has a height larger than the thickness of the plate-shaped portion 39 on the bottom surface 19c of the stem base 19, and is provided on the plate-shaped portion 39 so as to surround the subassembly 13.

Specifically, according to the optical module 11, the wall portion 41 can be made higher than the position of the front end of the heat sink 33 of the subassembly 13. The high wall portion 41 makes it possible to support the back surface 33b of the heat sink 33 over a large area, which helps to transfer the heat from the semiconductor laser to the stem base 19. For example, the heat sink 33 can have a length equal to or less than the height of the wall 41.

Further, the thickness in the radial direction of the stem base (thickness of the wall portion 41), for example, the distance between the side surface 19h of the stem base 19 and the back surface of the heat sink 33 is determined by the side surface 19h of the stem base 19 and the side surface of the through hole 19d. Specifically, it is larger than the distance from the side surface of the plate-shaped portion 39 that defines the through hole 19d). The thick wall 41 provides the stem base 19 with low thermal resistance.

The height of the wall portion 41 (maximum length from the bottom surface 19c of the first cavity 20 to the inner surface 19f of the stem base 19) is the thickness of the plate-shaped portion 39 (the outer surface 19g of the stem base 19 from the bottom surface 19c of the first cavity 20). Can be larger than the minimum length up to).

The through hole 19d penetrates the plate-shaped portion 39 and the wall portion 41 from the inner surface 19f to the outer surface 19g of the stem base 19, and provides the stem base 19 with a gap defined by the side surface 19i. The voids are filled with a sealing material 18 such as glass that holds the lead terminals 21, and the sealing material 18 enables airtight sealing. The encapsulant 18 has a thermal conductivity lower than that of the metal of the stem base 19.

The heat sink 33, the submount 29, and the semiconductor laser 27 are aligned on the side surface 19b of the stem component 17 with respect to the second axis Ax2 intersecting the first axis Ax1, and in the stem component 17, the lead terminal 21 Any two of them (in this embodiment, the lead terminal 21a and the lead terminal 21b as shown in the part (a) of FIG. 3) are on the reference plane extending in the direction of the first axis Ax1. Be arranged. In the optical module 11, the arrangement of the lead terminals 21a and the lead terminals 21b, the heat sink 33, the submount 29, and the semiconductor laser 27 are arranged in order in the direction of the second axis Ax2 as shown in the part (b) of FIG. Will be done. According to the positions of the lead terminal 21a and the lead terminal 21b, the arrangement of the lead terminal 21 can be separated from the subassembly 13 and the through hole 19d of the stem base 19 avoids diversion of heat from the semiconductor laser 27 in heat dissipation. it can.

The through hole 19d penetrates the plate-shaped portion 39 and the wall portion 41 from the inner surface 19f of the stem base 19 to the outer surface 19g. As shown in FIGS. 1, 2 and 3, the through hole 19d can be positioned so that a part of the through hole 19d is connected to the first cavity 20. Alternatively, as shown in FIGS. 4 and 5, the entire through hole 19d can be positioned so as to be separated from the first cavity 20.

In either form, the lead terminal 21a and the lead terminal 21b can have an end portion higher than the upper surface 41a of the wall portion 41.

Referring to FIGS. 1 to 5, in the stem component 17, the outer surface 41c of the wall portion 41 may form a part of the side surface 19h of the stem base 19. The side wall portion 23b of the cap component 15 is supported on the upper surface 41a of the wall portion 41. According to the optical module 11, a wall portion 41 having a height independent of the length of the side wall portion 23b of the cap component 15 can be provided to the stem base 19. Specifically, the upper surface 41a of the wall portion 41 can reach the outer edge of the stem component 17.

Alternatively, in the stem component 17, the wall portion 41 may be separated from the side surface 19h of the stem base 19 so that the plate-shaped portion 39 forms a flange. The cap component 15 can be supported at the flange of the plate-shaped portion 39 connecting the side surface 19h of the stem base 19 and the outer surface 41c of the wall portion 41, away from the outer surface 41c of the wall portion 41, and the plate-shaped portion 39. It protrudes from and forms a ridge shape. In resistance welding when the cap component 15 is joined to the stem component 17, the electrical resistance of the stem component 17 can be reduced.

(A) and (b) parts of FIG. 7, (a) and (b) parts of FIG. 8, (a) and (b) parts of FIG. 9, and (a) and (b) of FIG. Parts, and parts (a) and (b) of FIG. 11, are drawings showing the main steps in the method of manufacturing the optical module according to the present embodiment.

Part (a) of FIG. 7 is a top view schematically showing a process of preparing a stem component. Part (b) of FIG. 7 shows a cross section taken along the VIIb-VIIb line shown in part (a) of FIG.

The manufacturing method includes a step of preparing stem parts. In this step, specifically, the stem component 17 is prepared, but the present embodiment is not limited to this. The stem component 17 is provided with a sealing material 18, a stem base 19, a lead terminal 21a, and a lead terminal 21b. The lead terminal 21a and the lead terminal 21b are supported by the stem base 19.

The stem base 19 is provided with a plate-shaped portion 39 and a wall portion 41. The plate-shaped portion 39 extends along a reference plane intersecting the first axis Ax1 to provide the stem base 19 with the bottom surface 19c of the first cavity 20. The wall portion 41 rises from the plate-shaped portion 39 in the direction of the first axis Ax1 to provide the stem base 19 with the side surface 19b of the first cavity 20.

The stem base 19 is provided with a through hole 19d for the lead terminal 21. The stem component 17 has a sealing material 18 provided in the through hole 19d, and the sealing material 18 holds the lead terminal 21 in the through hole 19d to enable airtight sealing.

Specifically, the stem base 19 has an inner surface 19f, an outer surface 19g, and a side surface 19h. The inner surface 19f is on the opposite side of the outer surface 19g, and the side surface 19h extends from the inner surface 19f to the outer surface 19g. The through hole 19d extends in the direction from the inner surface 19f to the outer surface 19g, for example, in the direction of the first axis Ax1.

A recess 19e is provided on the inner surface 19f of the stem base 19 to define the first cavity 20.

The manufacturing method includes a step of preparing a subassembly. In this step, specifically, the subassembly 13 having the structure shown in the part (b) of FIG. 6 is prepared, but the present embodiment is not limited to this. The subassembly 13 is provided with a semiconductor laser 27, a submount 29, a heat sink 33 and a connecting component 34. The semiconductor laser 27, the submount 29, the heat sink 33, and the connecting component 34 are assembled so as to form the following structure.

Specifically, in the semiconductor laser 27, the first end surface 27a is aligned with the front end of the submount 29 and is fixed on the metal layer of the submount 29 by a solder material. The semiconductor laser 27 and the submount 29 are arranged in order in the normal direction of the main surface of the heat sink 33. The subassembly 13 has a back surface provided so that the stem base 19 can be supported on its side surface 19b.

The connecting component 34 is provided with a conductive first arm 34a and a second arm 34b, and the connecting component 34 is such that the first arm 34a and the second arm 34b project forward from the front edge of the heat sink 33. Is fixed to the main surface of the heat sink 33.

Specifically, the connecting component 34 includes a first bar 35 and a second bar 37 separated from each other acting as a first arm 34a and a second arm 34b, and each of the first bar 35 and the second bar 37 is made of metal. Including sticks. The first bar 35 and the second bar 37 are positioned on the main surface of the heat sink 33 so as to project from the front edge of the heat sink 33.

The front portion of the first bar 35 and the front portion of the second bar 37 project forward from the front edge of the heat sink 33, and the rear portion of the first bar 35 and the rear portion of the second bar 37 are fixed to the heat sink 33. Will be done. One rear portion of the first bar 35 and the second bar 37 is connected to the semiconductor laser 27 via the metal layer and the metal wire of the submount 29, and the other rear portion is connected to the semiconductor laser 27 via the metal wire. Connected to. In this embodiment, the submount 29 is provided between the rear portion of the first bar 35 and the rear portion of the second bar 37 on the main surface of the heat sink 33, and the first bar 35 and the second bar 37 are provided. Avoid making unintended contact with each other.

The heat sink 33 has a width wider than the width of the sub mount 29, and mounts the connecting component 34 so that the first bar 35 and the second bar 37 are separated from the sub mount 29. The first bar 35 and the second bar 37 are placed along the side sides of the heat sink 33, respectively.

The manufacturing method includes a step of preparing a cap part. Specifically, in this step, the cap component 15 is prepared, but the present embodiment is not limited to this. The cap component 15 is provided with a cap base 23 and an optical window 25. The cap base 23 includes a ceiling portion 23a and a side wall portion 23b, and the optical window 25 is supported by the ceiling portion 23a to close the opening 23c of the ceiling portion 23a. The side wall portion 23b extends from the ceiling portion 23a so as to separate the optical window 25 from the end portion of the side wall portion 23b. The end of the side wall 23b has a closed protrusion for resistance welding.

Example of material.
Stem base 19: Copper tungsten.
Cap base 23: Kovar.
Optical window 25: Zinc selenium.
Semiconductor laser 27: Quantum cascade laser of III-V compound semiconductor.
Base material of submount 29: Copper tungsten.
Base material of heat sink 33: Copper.
Bar of connecting part 34: Copper.

Part (a) of FIG. 8 is a top view schematically showing the positioning of the subassembly with respect to the stem component and the fixing of the subassembly to the stem component. Part (b) of FIG. 8 shows a cross section taken along the line VIIIb-VIIIb shown in part (a) of FIG.

The manufacturing method includes positioning the subassembly on the stem component. The subassembly 13 is aligned with the first cavity 20 of the stem component 17. In the alignment, specifically, the first axis Ax1, the second axis Ax2, and the third axis Ax3 intersecting the first axis Ax1 and the second axis Ax2 can be positioned as follows: 1st axis Ax1. With respect to, the subassembly 13 can be abutted against the bottom surface 19c of the stem component 17 to determine the height and orientation of the semiconductor laser 27; with respect to the second axis Ax2, the subassembly 13 can be placed on the side surface 19b of the stem component 17. The semiconductor laser 27 can be abutted and positioned; with respect to the third axis Ax3, the subassembly 13 can be positioned relative to the opening shape of the first cavity 20. In this step, the subassembly 13 is aligned with the stem component 17 with reference to the shape of the first cavity 20, but the present embodiment is not limited to this.

In the subassembly 13 aligned in the first cavity 20, at least a portion of the first arm 34a and the second arm 34b protrudes from the upper edge of the first cavity 20.

The manufacturing method includes fixing the subassembly to the stem component after alignment. Specifically, the heat sink 33 is fixed to the side surface 19b and the bottom surface 19c of the first cavity 20 by using the adhesive 31 to form an intermediate assembly.

The subassembly 13 of the structure shown in the part (b) of FIG. 6 is aligned as described above. Not only this, the subassembly 13 having the structure shown in part (c) of FIG. 6 can be similarly aligned with the stem component 17.

Part (a) of FIG. 9 is a top view schematically showing a stem component for the subassembly 13 having the structure shown in part (c) of FIG. Part (b) of FIG. 9 is a top view schematically showing an intermediate assembly including a subassembly 13 having the structure shown in part (c) of FIG.

Part (a) of FIG. 10 is a top view schematically showing the electrical connection of the stem component to the subassembly. Part (b) of FIG. 10 shows a cross section taken along the line Xb-Xb shown in part (a) of FIG.

The manufacturing method includes connecting the fixed subassembly to the lead terminals of the stem component. In this step, a metal wire is used for electrical connection, but the present embodiment is not limited to this.

Specifically, the semiconductor laser 27 of the subassembly 13 housed in the first cavity 20 is connected to the lead terminal 21 by using a gold wire. Specifically, while a part or all of the subassembly 13 is housed in the first cavity 20, at least a part of the first bar 35 and the second bar 37 protrudes from the upper edge of the first cavity 20. The lead terminals 21a and 21b are connected to the protruding first bar 35 and second bar 37 by using a gold wire, respectively.

According to the protrusion of the connecting component 34, a part or all of the subassembly 13, specifically a part or all of the electrodes of the semiconductor laser 27 and a part or all of the metal layer of the submount 29 are in the first cavity 20. In the housed structure, the lead terminal 21 can be easily connected to the connecting component 34.

Part (a) of FIG. 11 is a top view schematically showing the fixing of the cap component to the stem component. Part (b) of FIG. 11 shows a cross section taken along the XIb-XIb line shown in part (a) of FIG. Specifically, this step fixes the cap component 15 to the stem component 17 by resistance welding, but the present embodiment is not limited to this.

The cap component 15 is aligned on the stem component 17 and the cap component 15 is fixed to the stem component 17 to form an airtightly sealed second cavity 30.

As described above, the optical module according to the present embodiment can provide good heat dissipation to the package accommodating the semiconductor laser, and the stem component according to the present embodiment is good for the package accommodating the semiconductor element. It can provide heat dissipation ability.

Although the principles of the invention have been illustrated and demonstrated in preferred embodiments, it will be appreciated by those skilled in the art that the invention may be modified in arrangement and detail without departing from such principles. The present invention is not limited to the specific configuration disclosed in the present embodiment. Therefore, we claim all amendments and changes that come from the claims and their spiritual scope.

According to the present embodiment, it is possible to provide an optical module that imparts good heat dissipation to a package that houses a semiconductor laser, and to provide a stem component that gives good heat dissipation to a package that houses a semiconductor element.

11 ... Optical module, 13 ... Subassembly, 15 ... Cap part, 17 ... Stem part, 18 ... Encapsulant, 19 ... Stem base, 19a ... Surface, 19h ... Side, 19c ... Bottom, 19d ... Through hole, 19e ... Recess, 19f ... Inner surface, 19g ... Outer surface, 21 ... Lead terminal, 21a ... Lead terminal, 21b ... Lead terminal, 20 ... First cavity, 23 ... Cap base, 23a ... Ceiling part, 23b ... Side wall part, 23c ... Opening, 25 ... Optical window, 27 ... Semiconductor laser, 27a ... First end face, 27b ... Second end face, 28a ... Support, 28b ... Laminate, 28c ... Upper semiconductor region, 28d ... Core layer, 28e ... Lower semiconductor region, 29 ... Submount, 29a ... 1st surface, 29b ... 2nd surface, 29c ... Metal film, 30 ... 2nd cavity, 31 ... Adhesive, 33 ... Heat sink, 33a ... Mounting surface, 33b ... Back side, 34 ... Connecting parts, 34a ... 1st arm, 34b ... 2nd arm, 35 ... 1st bar, 37 ... 2nd bar, 39 ... Plate-shaped part, 41 ... Wall part, 41a ... Top surface, 41b ... Inner side surface, 41c ... Outer surface.

Claims (8)

It's an optical module
Cap parts including cap base and optical window,
A stem including an inner surface, an outer surface on the opposite side of the inner surface, a through hole extending from the inner surface to the outer surface, a stem base having a first cavity provided on the inner surface, and a lead terminal supported by the stem base. With parts
With subassemblies including semiconductor lasers and heat sinks
With
The stem component and the cap component are arranged in the direction of the first axis.
The subassembly and the optical window are arranged in the direction of the first axis.
The lead terminal passes through the through hole in the direction of the first axis.
The stem base has a surface that defines the first cavity.
The surface of the first cavity includes a side surface and a bottom extending in the direction of the first axis.
The subassembly is an optical module supported by the surface of the first cavity. The optical module according to claim 1, wherein the semiconductor laser includes a quantum cascade laser. The optical module according to claim 1 or 2, wherein the optical window can transmit light having a wavelength of 3 micrometers or more. The cap base includes a ceiling portion and a side wall portion that support the optical window.
The cap component and the stem component are provided on the stem base so that the stem base of the stem component supports one end of the side wall portion of the cap component, and the subassembly is airtightly sealed. 2. The optical module according to any one of claims 1 to 3, which defines a cavity. The subassembly includes a submount mounted on the heat sink.
The submount has a first surface on which the semiconductor laser is mounted and a second surface opposite to the first surface.
The optical module according to any one of claims 1 to 4, further comprising an adhesive for fixing the subassembly to the side surface of the first cavity. The semiconductor laser has a first end face optically coupled to the optical window and a second end face opposite to the first end face.
The optical module according to any one of claims 1 to 5, wherein the second end surface of the semiconductor laser is located in the first cavity. It ’s a stem part,
A stem base having an inner surface, an outer surface on the opposite side of the inner surface, a through hole extending from the inner surface to the outer surface, and a first cavity provided on the inner surface.
The lead terminal supported by the stem base and
With
The lead terminal passes through the through hole in the direction of the first axis.
The stem base has a surface that defines the first cavity.
The surface of the first cavity is a stem component including a side surface and a bottom surface extending in the direction of the first axis. The stem component according to claim 7, wherein the stem base has a thickness smaller than the depth of the first cavity on the bottom surface of the first cavity.

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