TWI490581B - Two-piece casing structure of transceiver optical sub-assembly and fabrication method thereof - Google Patents

Description

Two-piece housing structure and assembly method of optical sub-module

The invention relates to a two-piece housing structure of an optical sub-module and an assembly method thereof, in particular to a two-piece housing structure of an optical sub-module capable of adjusting the optical focal length of a laser functional component in three dimensions. And its assembly method.

According to the optical sub-module (OSA), the optical sub-module (OSA) can be roughly classified into a Transmitter Optical Sub-Assembly and a Transmitter Optical Sub-Assembly. Receiver optical sub-module ROSA (Receiver Optical Sub-Assembly). Among them, TOSA is to provide optical paths from functional components to optical fibers, such as from semiconductor laser components to optical fibers, or from light-emitting diode components to optical fibers, so that electrical signals can be converted into light and passed through the lens. Focus on retransmission within the fiber. As for ROSA, the optical path from the fiber to the photodetector is provided so that the light from the fiber is focused on the receiver and converted into an electrical signal. In addition, there are also bidirectional (Bi-Directional) or duplex (Duplex) optical sub-modules that combine TOSA and ROSA. Whether it is a TOSA, ROSA or a two-way optical sub-module, it is generally composed of a casing and a functional component. The functional element provides the function of a laser light source or a light receiver, and the housing provides a structure that combines with an external fiber (or fiber connector) and couples the fiber and the functional element to light signals. Due to the current design and production of optical sub-modules in the industry, the focus and emission angle problems caused by the packaging precision of functional components make the focus adjustment between the housing and the functional components in the actual production process. Therefore, in the industry, an optical sub-module having a two-piece housing has been developed, and the optical sub-module can be adjusted by disassembling the housing into two elements that can be horizontally displaced from each other to adjust the relative position. Focus adjustment work.

As shown in FIG. 1 , it is a schematic cross-sectional view of an optical sub-module having a two-piece housing. The optical sub-module 10 includes a laser function component 11 and a housing 12, and the housing 12 is further composed of a fiber holder 121 and a functional component holder 122. The laser function element 11 can be a laser light source, a light receiver or a bidirectional (duplex) functional element as described above, which generally includes a base 111 and a cover 112 coupled to the base 111. On the first surface 1111, at least one functional wafer 113 is disposed on the first surface 1111 of the pedestal 111 and located in the cover 112. A lens 114 is disposed on the cover 112 and corresponds to the functional wafer 113, and a plurality of The signal pin 115 extends from the second surface 1112 of the base 111. The functional component mount 122 is a hollow collar that is sleeved and secured to the base 111 of the laser functional component 11 to provide an interface in combination with the laser functional component 11. An optical fiber socket 1211 is disposed on the fiber holder 121, and an optical fiber (or a fiber connector, not shown) is inserted into the optical fiber to provide an interface with the optical fiber (or fiber connector). .

In the conventional technology, the functional component fixing base 122 is generally welded to the base 111 by means of an electrical resistance welding (ERW). Moreover, the inner diameter of the hollow collar of the functional component mount 122 is substantially equal to the outer diameter of the cover 112, so that once it is fitted over the cover 112, its position is fixed and cannot be adjusted. The fiber holder 121 is in contact with the upper surface 1221 of the functional component holder 122 and can be displaced in a two-dimensional direction on a plane perpendicular to the direction of the optical axis 13 (that is, the upper surface 1221 of the functional component holder). Adjust the movement and then fix the two by laser welding. Obviously, such a displacement in the two-dimensional direction cannot be satisfied by the need for focus adjustment due to the lack of displacement adjustment in the direction of the optical axis 13. Therefore, in the conventional art, the manufacturer must prepare a plurality of fiber holders 121 of different sizes (especially having different lengths in the direction of the optical axis 13). Then, for different focusing requirements of different laser functional components 11, fiber optic mounts 121 of different sizes are used to combine and match the functional component mounts 122. This assembly method not only increases the complexity and difficulty of production management, material preparation, and assembly process, but also drags down production efficiency and indirectly increases production costs, and needs further improvement.

The main object of the present invention is to provide a two-piece housing structure of an optical sub-module and an assembly method thereof, which can adjust the focusing work between the laser function component and the optical fiber in a three-dimensional direction, thereby simplifying production management, Material preparation and assembly processes, which in turn increase production efficiency and reduce production costs.

In order to achieve the above object, the present invention provides a two-piece housing structure for an optical sub-module, which can be used to combine a laser function component and an optical fiber, and includes: a fiber holder and a functional component holder. The fiber holder has an axial center through hole; a fiber insertion hole is disposed at one end of the center hole, and a first ring is disposed at the other end. The functional component holder has a second collar, and one end of the functional component holder is sleeved with the first collar in a mutually displaceable manner and linearly displaceable along the axial direction. The other end of the second collar is in contact with the surface of one of the bases of the laser functional element and is displaceable in a two-dimensional direction perpendicular to the axial direction. Thereby, the optical sub-module can perform focusing work in a three-dimensional direction during assembly, thereby simplifying production management, material preparation, and assembly processes, and improving production efficiency and reducing production cost.

Preferably, the laser function further comprises: a cover coupled to the first surface of the base, at least one functional wafer disposed on the first surface of the base and located within the cover, a lens setting On the cover and corresponding to the functional wafer, and a plurality of signal pins extending from the second surface of the base.

Preferably, the functional wafer comprises at least one of the following: a semiconductor laser wafer, a photodetection wafer.

Preferably, the first collar and the second collar have a smaller inner diameter, and the inner diameter is 70-200 μm larger than the outer diameter of the cover.

Preferably, the first collar is sleeved on an outer edge of the second collar, and the thickness of the first collar is less than 0.3 mm.

Preferably, an outer edge of the second collar closer to the end of the first collar is provided with an oblique angle such that the end of the second collar adjacent to the first collar has a relatively smaller outer diameter.

Preferably, an annular recess is provided on an inner edge of the second collar adjacent to the end of the base such that the end of the second collar adjacent to the base has a relatively small thickness.

Preferably, the axial displacement of the first collar in the state of being engaged with the second collar is adjusted to a distance of 150-400 μm.

To achieve the above object, the present invention also discloses an assembly method of an optical sub-module, comprising the following steps: First, a laser function component, a fiber holder, and a functional component holder are provided. The fiber holder has an axial center through hole, and one fiber insertion hole is disposed at one end of the center hole for receiving one of the outer fibers, and the other end of the center hole is provided with a hollow first ring. The functional component mount has a hollow second collar. The second collar is engaged with the first collar at one end of the axial direction. The entire set of optical sub-modules is then connected to a test machine to test its focus.

Then, the other end of the second collar on the axial direction is in contact with the surface of one of the laser functional elements, and the second collar is subjected to two-dimensional displacement adjustment perpendicular to the axial direction (ie, Adjust the launch angle) until the adjustment of the launch angle is accurate, and weld the contact surface of the second collar to the surface of the base by laser welding.

Thereafter, the first collar is linearly displaced along the axial direction (ie, the focal length is adjusted) until the contact surface of the first collar and the second collar is welded by laser welding after accurate focusing. Thus, the assembly work of the optical sub-module of the present invention is completed.

In order to more clearly describe the two-piece housing structure and assembly method of the optical sub-module proposed by the present invention, the following detailed description will be made in conjunction with the drawings.

Please refer to FIG. 2, which is a cross-sectional view showing an embodiment of an optical sub-module having a two-piece housing according to the present invention. The optical sub-module 20 includes a two-piece housing 30 and a laser function component 40 that can be combined with an external fiber or fiber optic connector 50 to transmit optical signals. In this embodiment, the laser function component 40 can be a conventional laser light source, a light receiver, or a bidirectional (duplex) functional component that simultaneously has a laser light source and a light receiver, including A base 41 and a cover 42 are coupled to the first surface 411 (upper surface) of the base 41. At least one functional wafer 43 is disposed on the first surface 411 of the base and located at the cover 42. A lens 44 is disposed on the cover 42 and corresponds to the functional wafer 43 and a plurality of signal pins 45 extend from the second surface 412 (lower surface) of the base 41. The functional chip 43 determines the functions that the laser function 40 can perform, which can be a semiconductor laser wafer (laser source), a photodetection wafer (light receiver), or both on the susceptor 41. The chip provides bidirectional (duplex) functionality. In this embodiment, the lens 44 is a spherical lens, but may be other types of lenses for providing the optical signal transmitted between the functional wafer 43 and the optical fiber 50 in the direction of the optical axis 60. Focus on work.

The housing 30 includes a fiber holder 31 and a functional component holder 32. The fiber holder can be inserted into one of the outer fibers 50 (or fiber connectors) to provide an interface with the fiber 50 (or fiber connector). The functional component mount 32 is for nesting and securing to the laser functional component 40, which provides an interface in combination with the laser functional component 40.

In the embodiment shown in FIG. 2, the outer portion of the fiber holder 31 is provided with a conventional quick release joint 311 structure for quick integration and detachment from the optical fiber 50 (or fiber connector). The center of the fiber holder 31 has an axial central opening 312 for the passage of light signals. One end of the central through hole 312 (upper end) is provided with a fiber insertion hole 313 for inserting the optical fiber 50, and the other end of the optical fiber fixing base 31 is provided with a hollow first first ring 314. In this embodiment, the thickness t1 of the first collar 314 is preferably less than 0.3 mm. Under such thickness, the first collar 314 and the function can be performed by laser welding. The surfaces in contact with the component holder 32 are fused to be integrally fixed.

In the present embodiment, the functional component fixing base 32 is in the appearance of a hollow second collar 321 . One end of the second collar 321 is axially engaged with the first collar 314 so as to be displaceable relative to each other, so that the first collar 314 can be held in engagement with the second collar 321 The linear displacement adjustment along the axial direction 60 is performed. Moreover, the other end of the second collar 321 in the axial direction 60 is in contact with the first surface 411 of the base 41 of the laser function element 40 so that the second collar 321 can be The contact is adjusted on the first surface 411 in a direction perpendicular to the two-dimensional direction of the axial direction 60. In this embodiment, the inner diameter of the first collar 314 is substantially equal to the outer diameter of the second collar 321 and is sleeved on the outer edge 3211 of the second collar 321 . Moreover, an oblique angle 3212 is disposed at the outer edge 3211 of the second collar 321 closer to the end of the first collar 314, so that the end of the second collar 321 adjacent to the first collar 314 has a relatively small The outer diameter; with this configuration, the first collar 314 can be more easily fitted over the second collar 321 . In addition, an annular recess 3213 is disposed on an inner edge of the second collar 321 adjacent to the end of the base 41, so that the second collar 321 has a relatively small thickness t2 adjacent to the end of the base 41; With such a structure, not only the bottom outer edge 421 of the cover 42 can be prevented from coming into contact with the bottom inner edge of the second collar 321 , but also the second collar 321 can be adjacent to the end of the base 41 because the thickness t2 is thin (less than 0.3 mm is preferred and can be bonded to the surface of the base 41 by means of laser welding instead of conventional ERW. Thus, the present invention is between the junction between the first collar 314 and the second collar 321 and between the bottom end of the second collar 321 and the upper surface of the base 41. The invention is combined by the same laser welding process, so that the invention has the advantages of simple and quick process compared to the prior art which requires two different welding techniques.

Due to the current technical limitations on the packaging accuracy of the functional component 43, the focal length and the emission angle tolerance range of the transmitted or received optical signal are respectively in the range of 150-400 μm and 70-200 μm; therefore, the present invention The distance d1 of the axial 60 displacement adjustment performed by the sleeve 314 in the state of being engaged with the second collar 321 is also in the range of 150-400 μm; meanwhile, the first collar 314 and the second sleeve The ring 321 has a smaller inner diameter (in the present embodiment, the second collar 321), and the inner diameter thereof is 70-200 μm larger than the outer diameter of the cover 42 (the number t2 in FIG. 2). ). In this way, the first collar 314 can perform the axial adjustment of the focal length adjustment on the second collar 321 in the range of 150-400 μm; and the second collar 321 can also be on the upper surface of the base 41 at 150-400 μm. A displacement perpendicular to the two-dimensional direction of the axial direction is performed within the range to adjust the emission angle. In this way, the optical sub-module 20 of the present invention can perform the three-dimensional focus adjustment work during the assembly process, and it is no longer necessary to replace the fixed-size fixing seats like the conventional technology, so that the production management and materials can be simplified. Preparation and assembly process, thereby improving production efficiency and reducing production cost. According to the two-piece housing 30 structure of the optical sub-module 20 of the present invention as shown in FIG. 2, a preferred embodiment of the assembly method includes The following steps: First, a laser function component 40, a fiber holder 31, and a functional component holder 32 are provided. The laser function 40 includes a base 41 and a cover 42 coupled to the first surface 411 of the base 41. At least one functional wafer 43 is disposed on the first surface 411 of the base 41. Located within the cover 42, a lens 44 is disposed on the cover 42 and corresponds to the functional wafer 43, and a plurality of signal pins 45 extend from the second surface 412 of the base 41. The two-piece housing 30 of the optical sub-module 20 includes a fiber holder 31 and a functional component holder 32. The fiber holder 31 has an axial central opening 312 for a light to pass through. One end of the central through hole 312 is provided with a fiber insertion hole 313 for accommodating one of the outer fibers 50, and the other end of the central through hole 312 is provided with a hollow first ring 314. The functional component mount 32 has a hollow second collar 321 . The second collar 321 is engaged with the first collar 314 in a mutually displaceable manner at one end of the axial direction 60. The entire set of optical sub-modules 20 is then coupled to a conventional test machine (not shown) to test its focus condition.

Then, the other end of the second collar 321 on the axial direction 60 is in contact with the first surface 411 of the base 41 of the laser function element 40, and the second collar 321 is on the first surface 411. Performing a two-dimensional displacement adjustment perpendicular to the axial direction 60 (ie, adjusting the emission angle) until the optical fiber 50, the lens 44, and the functional wafer 43 are accurately seated on the axial direction 60, and are laser welded. The second contact ring 321 is welded to the contact surface of the first surface 411 to fix the relative position of the second collar 321 and the laser functional element 40.

Thereafter, the linear displacement adjustment (ie, adjusting the focal length) along the axial direction 60 is performed while the first collar 314 is held in engagement with the second collar 321 until the optical fiber 50, the lens 44, and the functional wafer 43 are The relative position is such that after the light is accurately focused, the contact surface of the first collar 314 and the second collar 321 is welded by laser welding to fix the first collar 314 and the second collar 321 position.

The above-mentioned embodiments are not intended to limit the scope of application of the present invention, and the scope of the present invention should be based on the technical spirit defined by the content of the patent application scope of the present invention and the scope thereof. It is to be understood that the scope of the present invention is not limited by the spirit and scope of the present invention, and should be considered as a further embodiment of the present invention.

10. . . Optical submodule

11. . . Laser function

111. . . Pedestal

1111. . . First surface

1112. . . Second surface

112. . . Cover

113. . . Functional chip

114. . . lens

115. . . Signal pin

12. . . case

121. . . Fiber optic mount

1211. . . Fiber optic jack

122. . . Functional component mount

1221. . . Upper surface

13. . . Optical axis

20. . . Optical submodule

30. . . Two-piece housing

31. . . Fiber optic mount

311. . . Quick release joint

312. . . Center perforation

313. . . Fiber optic jack

314. . . First set of rings

32. . . Functional component mount

321. . . Second ring

3211. . . Outer edge

3212. . . bevel

3213. . . Annular groove

40. . . Laser function

41. . . Pedestal

411. . . First surface

412. . . Second surface

42. . . Cover

421. . . Outer edge

43. . . Functional chip

44. . . lens

45. . . Signal pin

50. . . Fiber (or fiber connector)

60. . . Optical axis

Figure 1 is a schematic cross-sectional view of an optical sub-module having a two-piece housing.

2 is a cross-sectional view showing an embodiment of an optical sub-module having a two-piece housing according to the present invention.

20. . . Optical submodule

30. . . Two-piece housing

31. . . Fiber optic mount

311. . . Quick release joint

312. . . Center perforation

313. . . Fiber optic jack

314. . . First set of rings

32. . . Functional component mount

321. . . Second ring

3211. . . Outer edge

3212. . . bevel

3213. . . Annular groove

40. . . Laser function

41. . . Pedestal

411. . . First surface

412. . . Second surface

42. . . Cover

421. . . Outer edge

42. . . Functional chip

44. . . lens

45. . . Signal pin

50. . . Fiber (or fiber connector)

60. . . Optical axis

Claims (25)

An optical sub-module two-piece housing structure for combining a laser functional component and an optical fiber; the laser functional component includes a base having a first surface and a second surface; The two-piece housing structure comprises: a fiber holder having an axial central opening for a light to pass through; a fiber insertion hole at one end of the central hole and a hollow first at the other end a collar; and a functional component holder having a hollow second collar; the second collar is nested at one end of the second collar and the first collar in a mutually displaceable manner, such that the first collar a set of rings can be linearly displaced along the axial direction while being held in engagement with the second set of rings; and the other end of the second set of rings in the axial direction is in contact with each other in a mutually displaceable manner a first surface of the base of the laser functional element, the second collar being contactable on the first surface for two-dimensional displacement adjustment perpendicular to the axial direction; wherein, when the second collar is The first set of rings is linearly displaced by mutual displacement After being completed, fixing is performed; wherein, when the other end of the second collar is displaced from each other in the axial direction, the first surface of the base of the laser function element is perpendicular to the axial direction. After the two-dimensional displacement adjustment is completed, it is fixed. The two-piece housing structure of the optical sub-module of claim 1, wherein the laser function component further comprises: a cover coupled to the first surface of the base, at least one function The wafer is placed on the pedestal The first surface is located in the cover, a lens is disposed on the cover and corresponds to the functional wafer, and a plurality of signal pins extend from the second surface of the base. The two-piece housing structure of the optical sub-module of claim 2, wherein the functional wafer comprises at least one of the following: a semiconductor laser wafer, a photodetecting wafer. The two-piece housing structure of the optical sub-module of claim 2, wherein the first collar and the second collar have a smaller inner diameter, and the inner diameter ratio is The outer diameter of the cover is 70-200 μm. The two-piece housing structure of the optical sub-module of claim 1, wherein the first collar is sleeved on an outer edge of the second collar; and the second sleeve is fixed The base of the ring and the laser function element, and the way of fixing the first and second sets of rings are laser welding. The two-piece housing structure of the optical sub-module of claim 5, wherein the first collar has a thickness of less than 0.3 mm. The two-piece housing structure of the optical sub-module of claim 5, wherein an outer edge of the second collar closer to the end of the first collar is provided with an oblique angle, so that the second The end of the collar adjacent the first loop has a relatively small outer diameter. The two-piece housing structure of the optical sub-module of claim 5, wherein an inner ring of the second collar adjacent to the end of the base is provided with an annular recess for the second sleeve The end of the ring adjacent the pedestal has a relatively small thickness. The two-piece shell of the optical sub-module as described in claim 1 The body structure method, wherein the axial displacement of the first collar in the state of being engaged with the second collar is adjusted by a distance of 150-400 μm. An optical sub-module assembly method includes the following steps: providing a laser functional component, a fiber optic mount, and a functional component mount, the laser functional component comprising: a base and a cover coupled to On a first surface of the base, at least one functional wafer is disposed on the first surface of the base and located in the cover, a lens is disposed on the cover and corresponds to the functional wafer, and the plurality of signal pins are self-aligned a second surface of the base extends; the optical sub-module structure includes: a fiber holder and a functional component holder; the fiber holder has an axial center hole for a light to pass through, at the center One end of the perforation is provided with a fiber insertion hole, and at the other end of the central perforation, a hollow first sleeve is provided; the functional component fixing seat has a hollow second collar; the second collar is in the axial direction One end is sleeved with the first collar in a mutually displaceable manner; the other end of the second collar is in contact with the first surface of the base of the laser function element, and the second The collar is at the first Performing a two-dimensional displacement adjustment perpendicular to the axial direction on the surface until the lens and the functional wafer system are seated in the axial direction, fixing the relative position of the second collar and the laser functional element; and, the first set The linear displacement adjustment along the axial direction is maintained while the ring is held in engagement with the second collar, until the relative positions of the lens and the functional wafer are used to focus the light, and the first collar and the second collar are fixed. Relative position. The assembly method of claim 10, wherein the fixing of the second collar and the laser function element and the fixing of the first collar and the second collar are laser welding. The assembly method of claim 10, wherein the functional wafer comprises at least one of the following: a semiconductor laser wafer, a photodetection wafer. The assembly method of claim 10, wherein the first collar and the second collar have a smaller inner diameter, and the inner diameter is larger than the outer diameter of the cover 70- 200 μm. The assembly method of claim 10, wherein the first loop is sleeved on an outer edge of one of the second loops. The assembly method of claim 14, wherein the first collar has a thickness of less than 0.3 mm. The assembly method of claim 14, wherein an outer edge of the second collar closer to the end of the first collar is provided with an oblique angle so that the second collar is adjacent to the end of the first collar It has a relatively small outer diameter. The assembly method of claim 14, wherein an annular recess is provided on an inner edge of the second collar adjacent to the end of the base, such that the second collar is adjacent to the end of the base. Relatively small thickness. The assembly method of claim 10, wherein the axial displacement of the first collar in the state of being engaged with the second collar is adjusted to a distance of 150-400 μm. A housing structure of an optical sub-module, which can be used to combine a laser function The component and an optical fiber, the laser functional component includes a cover; the housing structure of the optical sub-module includes: a fiber holder having an axial central through hole for a light to pass through; One end is provided with a fiber insertion hole, and the other end is provided with a hollow first sleeve; and a functional component fixing seat has a hollow second collar; the second collar is at one end of the axial direction And the first sleeve is sleeved in a mutually displaceable manner, so that the first sleeve can be linearly displaced along the axial direction while being held in a state of being engaged with the second collar; wherein the first sleeve The inner diameter of the collar and the second collar are smaller than the outer diameter of the cover of the laser function element by a predetermined size; wherein, the second collar and the second The set of rings is fixed in a manner of mutual displacement, and is fixed after the linear displacement adjustment is completed. The laser function component further includes: the cover is coupled to the first surface of the base, and the at least one functional wafer is disposed. On the first surface of the base and in the cover, The lens is disposed on the cover and corresponding to the functional wafer, and the plurality of signal pins extend from the second surface of the base; wherein the other end of the second collar is displaceable from each other in the axial direction Contacting the first surface of the base of the laser functional element such that the second collar is contactable on the first surface for two-dimensional displacement adjustment perpendicular to the axial direction; wherein, when the second set The other end of the ring in the axial direction is mutually The displacement is fixed in contact with the two-dimensional displacement perpendicular to the axial direction on the first surface of the base of the laser functional element. The housing structure of the optical sub-module of claim 19, wherein the functional wafer comprises at least one of the following: a semiconductor laser wafer, a photodetecting wafer. The housing structure of the optical sub-module of claim 19, wherein the first collar and the second collar have a smaller inner diameter, and the inner diameter is larger than the cover The outer diameter is 70-200 μm. The housing structure of the optical sub-module of claim 19, wherein the first collar is sleeved on an outer edge of the second collar; and the second collar and the lightning are fixed The pedestal of the functional element and the manner in which the first and second collars are secured are laser welded. The housing structure of the optical sub-module of claim 22, wherein the thickness of the first collar is less than 0.3 mm. The housing structure of the optical sub-module of claim 22, wherein an outer edge of the second collar closer to the end of the first collar is provided with an oblique angle so that the second collar is adjacent to the second collar. The end of the first set of rings has a relatively small outer diameter. The housing structure of the optical sub-module according to claim 19, wherein the distance of the axial displacement adjustment of the first collar in the state of being engaged with the second collar is 150. -400 μm.