KR20170129236A - Optical bench subassembly with integrated optical device - Google Patents

Abstract

An optical bench subassembly comprising an integrated optical device. The optical alignment of the optical device with the optical bench can be performed outside the optoelectronic package assembly, prior to attachment to the optoelectronic package assembly. The optical device is attached to the base of the optical bench and the optical input / output of the optical device is optically aligned with the optical input / output of the optical bench. The optical bench supports the array of optical fibers in a precise relationship to the structured reflective surface. The optical device is mounted on a sub-mount to be attached to the optical bench. The optical device can be actively or passively aligned with the optical bench. After achieving optical alignment, the sub-mounts of the optical device are fixedly attached to the base of the optical bench. The optical bench subassembly may be structured to be hermetically sealed as an enclosed feedthrough, such that it is hermetically attached to the enclosed optoelectronic package.

Description

Optical bench subassembly with integrated optical device

preference

The present invention relates to:

(1) U.S. Provisional Patent Application No. 62 / 136,601, filed March 22, 2015; And

(2) part-continuation of U.S. Patent Application No. 13 / 861,273, filed on April 11, 2013,

(a) U.S. Provisional Patent Application No. 61 / 623,027 filed on April 11, 2012,

(b) U.S. Provisional Patent Application No. 61 / 699,125 filed on September 10, 2012, and

(c) U.S. Patent Application No. 13 / 786,448, filed on March 5, 2013, which claims priority to U.S. Provisional Patent Application No. 61 / 606,885, filed March 5, 2012;

(3) a continuation-in-part of U.S. Patent Application No. 14 / 714,211, filed on May 15, 2015,

(a) U.S. Provisional Patent Application No. 61 / 994,094 filed on May 15, 2014,

(b) a continuation-in-part of U.S. Patent Application No. 14 / 695,008 filed on April 23, 2015.

Such applications are entirely incorporated by reference as if fully set forth herein. All publications mentioned below are incorporated by reference in their entirety as if fully set forth herein.

The present invention relates to optical bench subassemblies, in particular optical fiber subassemblies based on optical bench, and more particularly to an enclosed optical fiber feedthrough subassembly based on optical bench.

Transmitting optical signals through a fiber-optic waveguide has many advantages, and its utilization varies. Single or multiple fiber waveguides may be used to simply transmit visible light to a remote location. Complex telephony and data communication systems can transmit a plurality of specific optical signals. A data communication system includes an end-to-end relationship, including an optoelectronic device or an optical device, including optical components and electronic components that supply, detect, and / or control light, converting between optical signals and electrical signals Lt; RTI ID = 0.0 > fibers. ≪ / RTI >

For example, the transceiver Xcvr is an optoelectronic module including both a transmitter Tx and a receiver Rx combined with a network within the module housing, known in the prior art as a package. The package can be hermetically sealed to protect its contents from the atmosphere. The transmitter includes a light source (e.g., a VCSEL or a DFB laser), and the receiver includes an optical sensor (e.g., a photodiode PD). Until now, the circuitry of the transceiver (including, for example, a laser driver, a trans-impedance amplifier (TIA), etc.) is soldered onto a printed circuit board. Such a transceiver generally has a substrate forming the bottom or bottom of the package (enclosed or non-enclosed), and then an optoelectronic device such as a laser and a photodiode is soldered onto the substrate. The optical fiber is connected to the outside of the package or is supplied through the wall of the package using a sealed feedthrough (see US20130294732A1, which is incorporated herein by reference in its entirety, as incorporated herein by reference) .

The end of the optical fiber is optically coupled to an optoelectronic device held in the housing. The feedthrough element supports a portion of the optical fiber through the wall opening. In various applications, it is desirable to hermetically seal the optoelectronic device within the housing of the optoelectronic module, in order to protect the component from corrosive media, moisture, and the like. Since the package of the optoelectronic module must be hermetically sealed as a whole, the feedthrough element must be hermetically sealed so that the electro-optic components in the optoelectronic module housing are reliably and continuously protected from the environment.

For proper operation, an optoelectronic device supported on a printed circuit board needs to effectively couple light to an external optical fiber. Some optoelectronic devices require a single-mode optical connection that requires stringent alignment tolerances, typically less than one micrometer, between the optical fiber and the device. This allows a plurality of optical fibers to be coupled to a plurality of optoelectronic devices using an active optical alignment approach in which the position and orientation of the optical fiber (s) are adjusted by the machine until the amount of light transmitted between the fiber and the optoelectronic device is maximized. This is a particularly difficult problem in the case of multiple fiber applications where optical alignment is required.

Figures 1a and 1b illustrate a hermetically sealed optoelectronic package 500 having an enclosed multi-fiber feedthrough 502 wherein the enclosed feedthrough 502 is disposed on the bottom of the package 500 Is actively aligned with an optical device 504 mounted on a submount 506 that is supported by a submount 506 that is supported by the submount 506. In this example, the feedthrough 502 is similar to the optical coupling device disclosed in US2016 / 0016218A1, which is incorporated by reference in its entirety to the assignee / assignee of the present application and which is hereby incorporated in its entirety as described herein. The optical device 504 may include a VCSEL array and / or a PD array, which is supported on the package floor, for example, via a bottom mount 506 and a printed circuit board 508. [ The printed circuit board 508 may be populated with other electronic components and circuits, and the package 500 may include several printed circuit boards. After assembling the optical device 504 / sub-mount 506 and other components into the package 500, the feedthrough 502 is inserted into the snout 50 on the side wall of the housing 501 of the package 500, As shown in Fig. The array of optical fibers 20 of the optical fiber cable 21 is supported by the feedthrough 502 and is actively aligned with the optical device 504 so that the optical coupling efficiency between the optical device and the array of optical fibers 20, . This process requires that the electronics (not shown) associated with the optical device 504 be pre-assembled into the package 500. The optical device 504 is activated / energized to transmit / receive the optical signal 22 to / from an array of optical fibers 20. In essence, when the signal 22 transmitted between the optical fiber 20 and the optical device 504 is maximized, the optical signal to / from the optical fiber 20 is optimally coupled to the optical device 504. The feedthrough 502 is then soldered into the spout 50 at the package sidewall of the housing 501 in an optically aligned state.

Active optical alignment is a relatively complex and low throughput process because the VCSEL or PD must be energized during the active alignment process. Manufacturers of integrated circuits often have expensive equipment (e.g., wafer prober and handlers for testing integrated circuits) that enables micron-and-lower alignment, while companies packaging chips typically have poor performance Often, passive operation is used with machinery (typically several microns of alignment tolerance not suitable for single-mode devices).

Current state of the art is expensive due to the inclusion of packages, eliminating the use of general electronics and assembly processes and / or often not suitable for single-mode applications. The package is an assembly (including expensive circuit components, such as ICs) that is relatively more expensive than an enclosed feedthrough subassembly. Considering the pre-assembly of the required components in the package to support active optical alignment and also considering that the active alignment and soldering process involves a high risk step towards the end of the overall packaging process, Failure to achieve active alignment due to defective components, which can be induced in the optical device, can lead to the discarding of the entire package, including the already packaged optical devices and other components.

In addition, although the VCSEL and PD components can be tested in a stable state prior to assembly, such components can not be tested in operation until assembled into a package with electronics to drive such components. Thus, a burn-in process (to identify failures of short-lived components under simulated load conditions) of the VCSEL and PD components can be performed only after assembling these components into the package . This can result in additional disposal of the package (i.e., a lower yield of the package), which is a module that is relatively expensive when assembled, as a result of the VCSEL and PD components that have defects but are relatively less expensive. The VCSEL and PD components are known to contribute to the failure of a relatively large number of assembled packages.

An additional failure mode that leads to the disposal of the assembled package is a relatively larger and more complex structural (as indicated by the dotted line L in FIG. 1B) that maintains optical alignment between the optical device and the feedthrough, as shown in FIG. Loop. The long structural loops are more sensitive to thermo-mechanical deformation, which can cause the package to deviate from the intended specification and thus result in a failure mode.

What is needed is an improved structure for coupling the input / output of an optical fiber into an optoelectronic component / optical device in optical alignment, which improves throughput, tolerance, manufacturability, ease of use, functionality and reliability.

The present invention overcomes the disadvantages of the prior art and provides an improved structure for assisting optical alignment of an optical device with respect to an optical bench. The present invention combines an optical device and an optical bench into a subassembly such that alignment of the optical coupling of the optical device with the optical bench can be effected outside the optoelectronic package assembly.

According to the invention, the optical device is attached to the base of the optical bench, and the optical input / output of the optical device is optically aligned with the optical input / output of the optical bench.

In one embodiment, the optical bench supports an optical component in the form of an optical waveguide (e.g., an optical fiber). In a more specific embodiment, the base of the optical bench forms at least one groove-shaped alignment structure for precisely supporting the end section of the optical fiber. Optical elements (e.g., lenses, prisms, reflectors, mirrors, etc.) can be provided in a precise relationship with respect to the end face of the optical fiber. In a further embodiment, the optical element comprises a structured surface (e.g., an aspherical mirror surface) that may be planar or concave-reflective.

In one embodiment, the light device can be mounted on a sub-mount that is optically aligned with the optical bench and attached to the base of the optical bench. The sub-mount may comprise circuitry, electrical contact pads, circuit components (e.g., a driver for a VCSEL, a TIA for a PD), and other components and / or circuitry associated with operation of the optical device.

The optical device may be passively aligned with the optical bench (e.g., depending on the alignment indication provided on the base of the bench). Alternatively, the optical device and the optical bench can be actively aligned by passing an optical signal between the optical waveguide and the optical device in the optical bench. Optical devices (e.g., VCSELs and / or PDs) are activated to allow active alignment with optical waveguides (e.g., optical fibers) supported in an optical bench, independent of other components in the package . After achieving optical alignment, the sub-mounts of the optical device are fixedly attached to the base of the optical bench.

The base of the optical bench is preferably formed by stamping a malleable material (e.g., metal) to form the precise geometry and features of the optical bench. The optical bench subassembly may be structured to be hermetically sealed.

In another embodiment of the present invention, the optical bench comprises a plurality of waveguides (e.g., a plurality of optical fibers) and a plurality of waveguides (e.g., a plurality of waveguides) for working with arrays of optical devices (VCSELs and / Is structured to support a surface (e.g., an array of mirrors).

Prior to assembling into a larger optoelectronic package, the present invention preassembles optical elements and components and optical devices into an optical bench subassembly. The subassembly can be functionally tested outside the optoelectronic package at the subassembly level, including high temperature inspection tests, thereby reducing the disposal of the more expensive optoelectronic packages resulting from premature failure in the internally installed optical device .

For a more complete understanding of the nature and advantages of the invention, as well as its preferred mode of use, reference will now be made to the following detailed description, taken in conjunction with the accompanying drawings. In the following drawings, like reference numerals designate like or like parts throughout the drawings.
1A shows an enclosed optoelectronic package including an enclosed optical fiber feedthrough; 1B is a cross-sectional view taken along line 1B-1B of FIG. 1A.
Figure 2a shows an optical bench subassembly in the form of an enclosed feedthrough integrated with an optical device, in accordance with an embodiment of the present invention; Figure 2B is a cross-sectional view taken along line 2B-2B of Figure 2A, shown as being installed in an enclosed optoelectronic package.
Figure 3a is an exploded view of an optical bench in the optical bench subassembly of Figure 2, in accordance with one embodiment of the present invention; Figure 3b is an assembly view of the optical bench.
4A is an exploded view of an optical bench in an optical bench subassembly, in accordance with another embodiment of the present invention; Figure 4b is an assembly view of the optical bench.
Figure 5 shows an alternative embodiment of a sub-mount for an optical device in an optical bench subassembly.
Figures 6A-6C illustrate the assembly sequence of an enclosed optoelectronic package, Figure 6A shows the assembly of an optical device assembly; Figure 6b shows the assembly and active alignment of the optical device assembly with respect to the optical bench; Figure 6c shows the assembly of an enclosed optoelectronic package.
Figure 7 shows an enclosed feedthrough as provided in an enclosed optoelectronic package.

The present invention is described below with reference to various embodiments with reference to the drawings. While the present invention has been described in connection with the best mode for carrying out the objects of the invention, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention. It will be possible.

The present invention overcomes the disadvantages of the prior art and provides an improved structure for assisting optical alignment of an optical device with respect to an optical bench. The present invention combines an optical device with an optical bench within a subassembly such that alignment of the optical coupling of the optical device with the optical bench can be effected outside the optoelectronic package assembly.

According to the invention, the optical device is attached to the base of the optical bench, and the optical input / output of the optical device is optically aligned with the optical input / output of the optical bench. Various embodiments of the present invention may be practiced in various embodiments including various proprietary rights, including optical bench subassemblies for use with optical data transmission, including concepts disclosed in the patent disclosure described below, Includes some of the progressive concepts developed by nanoPrecision Products, Inc., the assignee of the invention. The priority of the pending application is hereby claimed.

For example, U.S. Patent Application Publication No. US2013 / 0322818A1 discloses an optical coupling device for routing an optical signal, in the form of an optical bench having a stamped structured surface for routing optical data signals. The optical bench includes a metal base having a structured surface as defined in such US patent application publication, and such structured surface has a surface profile that bends, reflects, and / or reshapes incident light. The base helps precisely position optical components (e.g., optical fibers) on the base to a structured surface and precise optical alignment so that light can be transmitted along a defined path between the structured surface and the optical component Wherein the structured surface and the alignment structure are integrally formed on the base by stamping a malleable metal material to form an optical bench.

U.S. Patent Application Publication No. US2015 / 0355420A1 further discloses an optical coupling device for routing an optical signal for use in an optical communication module, particularly an optical coupling device in the form of an optical bench, wherein the incident light is bent, And / or a structured surface having a surface profile for re-shaping is formed on the metal base. The alignment structure may be configured to facilitate placement of the optical component (e.g., an optical fiber) on the base in an optical alignment with the structured surface so that light can be transmitted along a defined path between the structured surface and the optical component And a surface feature. The structured surface and the alignment structure are integrally formed on the base by stamping the malleable metal material of the base. The alignment structure aids in passively aligning the optical components on the base with the structured surface so that light can be transmitted along a prescribed path between the structured surface and the optical component.

U.S. Patent Application Publication No. US2013 / 0294732A1 discloses an encapsulated optical fiber alignment assembly having integrated optical elements, particularly a housing comprising an optical bench comprising a metal ferrule portion having a plurality of grooves for receiving end sections of the optical fiber, Type optical fiber alignment assembly, which defines the position and orientation of the end sections relative to the ferrule portion. The assembly includes an integrated optical element for coupling the input / output of the optical fiber to the optoelectronic device in the optoelectronic module. The optical element may be in the form of a structured reflective surface. The end of the optical fiber is aligned with it at a defined distance relative to the structured reflective surface. The structured reflective surface and the fiber alignment grooves can be formed by stamping a malleable metal to form such features on the metal base.

U.S. Patent No. 9,213,148 further discloses a similar encapsulated optical fiber alignment assembly, but does not have an integrated structured reflective surface.

U.S. Patent No. 7,343,770 discloses a novel precision stamping system for manufacturing parts of small tolerances. Such a progressive stamping system can be implemented in a variety of stamping processes to produce the devices disclosed in the aforementioned patent publications. This stamping process may be used to form the geometry of the final overall geometry and surface features with rigorous (i.e., small) tolerances, including reflective surfaces having precisely aligned desired geometries and other formed surface features, And stamping a bulk material (e.g., a metal blank).

U.S. Patent Application Publication No. US2016 / 0016218A1 further discloses a composite structure comprising a base having a major portion made of different metallic materials and a base portion. The base and auxiliary portions are formed by stamping. As the ancillary portion is stamped, the ancillary portion engages the base and simultaneously forms the desired structured feature on the ancillary portion, such as a structured reflective surface, a fiber optic alignment feature, and the like. With this approach, relatively less important structured features can be molded on the bulk of the base with little effort to maintain a relatively large tolerance, while relatively more important structured features on the ancillary portion are dimensioned with relatively small tolerances, geometric Shape, shape and / or additional details to define the finishing. The ancillary portion may include additional composite structures of two different metal materials associated with different properties for stamping different structured features. This stamping approach improves the prior stamping process of U.S. Patent No. 7,343,770, wherein the bulk material to be stamped is a homogeneous material (e.g., a strip of metal such as Kovar, aluminum, etc.). The stamping process produces structural features from a single homogeneous material. Accordingly, the different features may share properties of the material that may not be optimized for one or more features. For example, materials with properties suitable for stamping alignment features may not have properties suitable for stamping reflective surface features with optimal light reflection efficiency to reduce optical signal loss.

U.S. Patent No. 8,961,034 discloses a method of forming a body having a plurality of generally U-shaped longitudinal openings each having a longitudinal opening provided on the surface of the body, Discloses a method of producing a ferrule for supporting an optical fiber, wherein each groove has a size to securely hold the optical fiber in the groove by tightening the optical fiber. The optical fiber does not require additional fiber retaining means and is reliably retained within the body of the ferrule.

PCT Patent Application Publication No. WO2014 / 011283A2 discloses a ferrule for a fiber optic connection that overcomes many of the disadvantages of prior art ferrules and connections and further improves the aforementioned pin-less alignment ferrules. The fiber optic connection includes an optical fiber ferrule having a generally oval cross-section for aligning an array of a plurality of optical fibers with a fiber to be held in another ferrule using a sleeve.

The foregoing progressive concepts are incorporated herein by reference and will be discussed below to aid in the disclosure of the present invention. The present invention is disclosed with an exemplary embodiment of an enclosed optical fiber feedthrough for an enclosed optoelectronic package, wherein the optical device includes an integrated optical bench subassembly.

Figures 2a and 2b illustrate one implementation of an enclosed optical fiber feedthrough in the form of an optical bench subassembly 10 including an optical bench 11 with an optical device 12 integrated in accordance with an embodiment of the present invention. Fig. Optical device 12 is attached to optical bench 11 at a position aligned with the optical input / output of optical bench 11 (see optical signal 22 in Figure 2b) And is mounted on the mounting portion 14.

Figures 3a and 3b more clearly show the structure of the optical bench 11 in the optical bench subassembly 10. In this embodiment, the optical bench 11 is similar to the enclosed multi-fiber alignment subassembly disclosed in US2016 / 0016218A1 of the assignee recited above. The optical bench supports one or more optical waveguides, which are a plurality of optical fibers 20 of the optical fiber cable 21 in the illustrated embodiment. In the case of a plurality of fibers, the base 13 of the optical bench 11 forms a plurality of open grooves 16 for supporting the optical fibers 20, and an optical element (e.g., a lens, a prism, Mirrors, etc.). In the illustrated embodiment, the optical element comprises an array of structured reflective surfaces 17, each corresponding to an optical fiber 20. The reflective surface may be planar reflective or may be contoured to be concave (e. G., Aspherical mirror surface) or convex reflective. In the illustrated embodiment, the base 13 includes a composite structure, which comprises an auxiliary portion 30 made of a material different from the rest of the base 13 (i. E., The material of the main portion 13 ' The base portion 13 including the portion 30 is stamped from the malleable material to form the body geometry and the desired surface features. Base 13 is stamped from other malleable metal materials to form grooves 16 and other structures as shown, while stamping is done by stamping a malleable metal material to form an array of grooves 16. As disclosed in US2016 / 0016218A1 Similarly, when the auxiliary portion 30 is stamped, the auxiliary portion engages the base 13, such as a rivet, and at the same time supports the array of structured reflective surfaces 17 and the end section of the optical fiber 20 Optical fiber alignment (I. E., Input / output) of each reflective surface 17 and the corresponding optical fiber 20, thereby forming the desired structured feature on the auxiliary portion 30, The auxiliary portion 30 and the main portion 13 'are stamped using different metal materials.

The open grooves 16 and 18 may be formed in accordance with the stamped open grooves disclosed in U.S. Patent No. 8,961,034, which securely fastens the optical fiber in the groove without requiring additional fixing means (e.g., without epoxy or the like) And can be formed and formed. In the illustrated embodiment, a cover 15 is provided to cover the base 13 without covering the structured reflective surface 17. (E. G., Glass epoxy) is applied to fill the space around the section of the optical fiber 20 in the cavity 19 between the cover 15 and the base 13, thereby forming a hermetic seal To form an optical bench 11 into an enclosed feedthrough and such feedthroughs can be used to form the optical bench assembly 10 except that the optical bench 11 has an integrated optical device to form an optical bench assembly 10 in accordance with the present invention. May be used with the optoelectronic package in a similar function to the enclosed feedthrough 502 of FIG. 1A. More details on similar enclosed feedthrough constructions may be found in US2013 / 0294732A1.

Figs. 4A and 4B show another embodiment of an optical bench 11 ', similar to the optical bench 11 of Figs. 3A and 3B, except for the fiber cable 21. Fig. In this embodiment, the optical bench 11 'has a detachable connection in the form of a ferrule 30. Instead of the optical fiber 21 extending away from the optical bench 11 ', the ferrule 30 supports the rear end section of the short section of the optical fiber 20 and the distal front end section of the optical fiber is the optical bench 11' Gt; 16 < / RTI > The ferrule 30 can be structured to have a generally egg-shaped cross-section, as disclosed in WO2014 / 011283A2. May be coupled to an optical fiber cable (e.g., patch cable) terminated with a similar ferrule, for example, using a sleeve (not shown). In this embodiment, if the connecting of the optical fibers is defective, the optical fibers can be separated and replaced without the need to replace the entire optoelectronic package to which the optical bench 11 'is permanently or fixedly attached.

Referring now to the optical device, in the embodiment shown in Figs. 2A and 2B, the optical device 12 is mounted to the sub-mount 14 to form the optical device assembly 23. The lower mount 14 includes circuitry, electrical contact pads, circuit components (e.g., a driver for the VCSEL, a TIA for the PD), and other components and / or circuitry associated with the operation of the optical device 12 can do.

6A to 6C show the assembling procedure of the sealed optoelectronic package. Figure 6a shows the assembly of an optical device (transmitter or receiver or transceiver) assembly; Figure 6b shows the assembly and active alignment of the optical device assembly with respect to the optical bench; Figure 6c shows the assembly of an enclosed optoelectronic package.

Referring to FIG. 6A, when the optical device 12 is a transmitter such as a VCSEL, it is mounted on the lower mount 14 together with the driver chip. The VCSEL may be wire bonded to the circuit on the lower mount 14. [ To verify that the VCSEL is operated to transmit an optical signal after assembly, a test can be performed. When the optical device 12 is a receiver such as a PD, it is mounted on the lower mount 14 together with the TIA chip. The PD can be wire bonded to the circuit on the lower mount 14. [ After assembly, a test can be performed to verify that the PD is operated to receive the optical device and output an electrical signal. In the case of a transceiver, the above described procedures are combined to test separate receive and transmit functions. The optical device 12 may include a plurality of receivers, transmitters, and / or transceivers mounted on the sub-mount 14.

6B, the input / output of the optical device 12 is coupled to the input (not shown) of the optical bench 11 so that the optical path 22 achieves the desired optical coupling efficiency between the optical device 12 and the optical fiber 20. [ A lower mount 14 of the optical device assembly is mounted on the opposite surface 13 of the base 13 of the optical bench 11 at a location where the optical device 12 is optically aligned with the optical bench 11, Respectively. 2B, the optical path 22 is located between the input / output end of the optical device 12 and the corresponding input / output end surface of the optical fiber 20, ) (E. G., An aspherical mirror surface). In the embodiment shown in more detail, the optical path has a direction away from the plane of the base 13, which is generally perpendicular to the plane of the base 13. 2b, the plane of the lower mounting portion 14 is parallel to the plane of the base 13. As shown in Fig. The frame 32 is provided as a separation between the lower mounting portion 14 and the opposed surface of the base 13 to provide a space for accommodating the light device 12 between the lower mounting portion 14 and the base 13. [ do. In the illustrated embodiment, there is an array of four reflective surfaces 17 corresponding to an array of four optical fibers 20.

The optical device 12 may be passively aligned with the optical bench 11 (e.g., by relying on an alignment mark (not shown) provided on the base of the bench 11). Optical device 12 and optical bench 11 may be configured to pass an optical signal between an optical waveguide (i.e., optical fiber 20) in optical bench 11 and optical device 12, Or by measuring the intensity of the optical signal in the optical path to determine the optical coupling that is indicative of the state of the optical path. The optical device 12 (e.g., a VCSEL and / or a PD) is activated so that the optical bench subassembly 10 can be supported in the optical bench 11 without depending on other components in the optoelectronic package Lt; RTI ID = 0.0 > fiber optic < / RTI > For example, when the optical device 12 is a transmitter (e.g., a VCSEL), the transmitter is energized to emit the light that it intends to direct toward the end face of the corresponding optical fiber 20 to the reflective surface 17 do. The intensity of the optical signal transmitted through the reflective surface 17 and through the corresponding optical fiber is measured to determine the optical coupling between the transmitter and the optical bench 11. In the case where the optical device is a receiver (e.g., PD), an optical signal is supplied through the optical fiber, and such optical signal is reflected by the reflective surface to the corresponding receiver. The extent of the optical coupling between the optical fiber and the receiver can be determined from the electrical output of the receiver (corresponding to the intensity of the received optical signal), thereby identifying the alignment state. The active alignment process includes moving the optical device 12 relative to the reflective surface 17 in the plane of the sub-mount 14 while the optical coupling efficiency is determined relative to the alignment point. An electrically conductive pad is provided on the surface of the lower mount facing away from the base 13 to facilitate electrical connection for performing active alignment.

Once the desired optical alignment is achieved, the bottom mount 14 of the optical device 12 is fixedly attached to the base of the optical bench, for example, by laser welding, brazing, or epoxy.

After assembly of the optical bench subassembly 10, it can be subjected to a high temperature inspection and further functional testing to remove too fast a failure.

The above-described embodiment of the optical bench subassembly 10 including the integrated light device 12 is an enclosed feedthrough incorporating the light device 12.

6C, and upon completion of assembly of the optical bench subassembly 10, it is hermetically attached to the optoelectronic package 500 '(e.g., by soldering) , Such an optoelectronic package 500'is similar to the package 500 of FIG. 1A except that the optical device 12 is optically aligned with the optical bench 11 and integrated into the optical bench subassembly 10 . The optoelectronic package 500 'is filled with various components (e.g., IC, chip, sub-mount, circuit board, etc.). The optical bench subassembly 10 as an enclosed feedthrough is inserted through an opening in the spout 50 in the side wall of the housing 501 'of the package 500' and is hermetically sealed (e.g., by soldering) do. In comparison to the situation of FIG. 1B, the position of this feedthrough relative to the package 500 'is not important because no optical alignment between the feedthrough and the external light device is required within the package 500'. As shown in Figure 2B, using the vias 36 provided through the base of the lower mount 14 to connect to the optical device 12 on the other side of the lower mount 14, the lower mount 14 May be soldered to the printed circuit board 39 (which may be a flexible printed circuit board) within the package 500 '. A ball-grid array (BGA) having a micro-solder ball joint may be configured on the sub-mount 14. [ Other electrical connections may include the optical bench subassembly 10 'of the embodiment of FIG. 5 wherein the bendable traces 38 provided on the sides of the lower mount 14' are connected by wire bonding or bending common lines 37 electrically connected to a circuit board (not shown) in the package 500 '. Alternatively, a spring pin (not shown) may be configured to form an electrical connection between the printed circuit board and the lower mount within the package 500 '. This electrical connection absorbs misalignment and stresses due to thermal expansion / contraction, which will not affect the optical alignment between the optical bench in the optical bench subassembly and the integrated optical device onboard.

Figure 7 shows a closed feedthrough / optical bench subassembly 10 as provided in an enclosed optoelectronic package 500 '. Other electronic devices and circuit components are omitted in Fig. A hermetically sealed cover of the enclosed optoelectronic package 500 'is also omitted from the drawing.

After the assembly of the optical bench subassembly 10 to the enclosed optoelectronic package 500 ', the package 500' can be inspected at a high temperature to remove too early failures and can be further functional tested.

Prior to assembly into a larger optoelectronic package, the present invention contemplates precisely preassembling the optical elements and components and optical devices in an optical bench subassembly, the optical bench subassembly may include, outside the optoelectronic package, (Including expensive circuit components, such as ICs) resulting from premature failure of an internally installed optical device, which may be functionally tested, including high temperature inspection tests, Disposal can be reduced. The active alignment process for the optical bench subassembly is much easier. In addition, a much smaller, more robust structural loop is provided between the optical bench and the optical device. Accordingly, in an optoelectronic package including a sealed feedthrough according to the present invention, overall greater yield, greater reliability, and lower manufacturing cost can be achieved.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, those skilled in the art will recognize that various changes in form and detail may be made therein without departing from the spirit, scope, and teachings of the invention You will understand. Accordingly, the disclosed invention is to be considered as illustrative only and is limited in scope only as embodied in the appended claims.

Claims (20)

An optical bench subassembly for routing optical signals comprising:
As an optical bench:
donate;
A structured surface formed on the base and having a surface profile that reshapes and bends incident light;
Optical components; And
Wherein the optical component is disposed on the base in optical alignment with the structured surface so that an optical signal is transmitted along a defined optical path between the structured surface and the optical component, An alignment platform formed on the base, the optical path comprising an alignment structure extending from the structured surface to the exterior of the base; And
An optical device assembly, comprising an optical device, wherein the optical device is attached to the base in a state optically aligned with the structured surface along the optical path. The method according to claim 1,
Wherein the optical component comprises an optical waveguide. 3. The method of claim 2,
Wherein the optical waveguide comprises an array of optical fibers, the structured surface comprising an array of structured reflective surfaces. The method of claim 3,
Further comprising a cover hermetically attached to the base to hermetically seal a space around a section of the array of optical fibers, wherein the cover is not extended to cover the structured surface, thereby providing an enclosed feedthrough Gt; subassembly. ≪ / RTI > 5. The method of claim 4,
The optical device assembly includes a sub-mount, on which the optical device is mounted, and the sub-mount is attached to the base of the optical bench with the optical device in optical alignment with the structured surface , Optical bench subassembly. 6. The method of claim 5,
Wherein the optical device comprises a transmitter, a receiver, or a transceiver. The method according to claim 6,
Wherein the optical device is passively aligned with the structured surface. The method according to claim 6,
Wherein the optical device is actively aligned with the structured surface. The method according to claim 1,
Wherein the structured surface and the alignment structure are integrally formed on the base by stamping a malleable material of the base. 10. The method of claim 9,
The base comprising:
A major portion of a first material forming a first structured feature; And
A second portion of a second material forming a second structured feature on a second material different from the first material,
The auxiliary portion forms a composite structure that is structurally coupled to the base and thereby includes a major portion of a first material having a first feature formed thereon and a second portion of a second material having a second structured feature formed thereon, And wherein the first and second structured features form an optical path for routing the optical signal. A sealed optoelectronic package:
housing;
An electronic component filled into the housing; And
And an optical bench subassembly according to claim 4, which is hermetically attached to the housing. 12. The method of claim 11,
Wherein the optical bench subassembly is functionally tested prior to being hermetically sealed to the housing. A method of assembling an optical bench subassembly for routing an optical signal comprising:
Providing an optical bench, said optical bench comprising:
donate;
A structured surface formed on the base and having a surface profile that reshapes and bends incident light;
Optical components; And
Wherein the optical component is disposed on the base in optical alignment with the structured surface so that an optical signal is transmitted along a defined optical path between the structured surface and the optical component, The optical path comprising an alignment structure extending from the structured surface to the exterior of the base, the alignment path formed on the base, the optical path comprising a feature;
Providing an optical device assembly comprising an optical device;
Optically aligning the optical device with the structured surface along the optical path; And
And attaching the optical device assembly to the base upon optical alignment. 14. The method of claim 13,
The optical component comprising an array of optical fibers, the structured surface comprising an array of structured reflective surfaces, the method comprising the steps of: sealing the space around a section of the array of optical fibers, Wherein the cover is not extended to cover the structured surface, thereby causing an enclosed feedthrough. ≪ RTI ID = 0.0 > [0002] < / RTI > 15. The method of claim 14,
The optical device assembly includes a sub-mount, on which the optical device is mounted, and the sub-mount is attached to the base of the optical bench with the optical device in optical alignment with the structured surface , Way. 16. The method of claim 15,
Wherein the optical device comprises a transmitter, a receiver, or a transceiver. 17. The method of claim 16,
Wherein the optical device is actively and optically aligned with the structured surface. 18. The method of claim 17,
Wherein the optical bench assembly is functionally tested at a subassembly level, including high temperature inspection tests. A method of forming an encapsulated optoelectronic package comprising:
Providing a housing;
Filling an electronic component within the housing; And
A method, comprising: sealingly mounting an assembled optical bench subassembly according to claim 14 to said housing. 20. The method of claim 19,
Wherein the optical bench subassembly is functionally tested, including a high temperature inspection test, prior to being hermetically sealed to the housing.

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