Active alignment of optical dies to optical substrates

Abstract

An assembly system for assembling an optical die to an optical substrate includes a testing apparatus configured to test an optical coupler formed between the optical die and the optical substrate. The assembly system is configured to adjust an alignment of the optical die relative to the optical substrate until the optical coupler meets a performance metric. After the performance metric is met, the optical die and optical substrate are permanently attached.

Description

[0001] Cross-references to related applications

[0002] This patent application claims the benefit of U.S. Patent Application No. 16 / 786,830, filed February 10, 2020. The disclosure of that application, in its entirety, is incorporated herein by reference for all purposes. Background Technology

[0003] Many electronic devices used today, such as Ethernet systems, audio and communication systems, and upcoming quantum computers, include one or more optical circuits. In some applications, optical circuits are constructed by attaching one or more optical dies to an optical substrate for performing optical routing and communication between the dies. When each optical die is attached to the optical substrate, one or more optical couplers are formed between each dies and the substrate, allowing optical signals to be transmitted to and from the dies. Some applications can benefit from optimal alignment of the optical couplers to minimize optical signal loss and / or distortion, thereby meeting necessary system requirements.

[0004] Existing assemblers that align and attach optical dies to optical substrates use camera imaging at the top of the substrate and the bottom of the die to align the die's geometry with the substrate's geometry. However, these image-based alignment systems only align the geometry and do not adjust the die's position to optimize optical signal loss and distortion in the optical coupler formed between the die and the substrate. New assemblers are needed that optimize the performance of the optical coupler to minimize signal loss and distortion in the optical system. Summary of the Invention

[0005] In some embodiments, a tool for an assembly machine includes a connector for connecting the tool to the assembly machine and a mating surface for temporarily connecting the tool to an optical die. A holding device is configured to temporarily couple the optical die to the mating surface, and a tool optical coupler is located at the mating surface and configured to form an optical connection to the optical die when the optical die is located at the mating surface. In various embodiments, the tool optical coupler is a terminated optical fiber.

[0006] In some embodiments, the tool optical coupler is configured to operatively couple an optical testing device to an optical die. In various embodiments, the tool optical coupler is a first tool optical coupler, and the tool includes a second tool optical coupler configured to form an optical connection with the optical die when the optical die is located on a mating surface. In some embodiments, the holding device is a vacuum port that applies a vacuum to the optical die to temporarily couple the optical die to the mating surface.

[0007] In some embodiments, a method for aligning an optical die with an optical substrate includes: temporarily coupling the optical die to a tool and positioning the tool such that the optical die is located at a surface of the optical substrate to form at least one optical coupler between the optical substrate and the optical die; performing a first optical performance test on the at least one optical coupler; moving the tool such that the optical die is moved relative to the optical substrate, and performing a second optical performance test on the at least one optical coupler; and comparing the result of the first optical performance test with the result of the second optical performance test.

[0008] In some embodiments, the optical substrate includes at least one optical connector, enabling the optical testing equipment to perform a first optical performance test and a second optical performance test on at least one optical coupler. In various embodiments, the tool includes at least one optical connector, enabling the optical testing equipment to perform a first optical performance test and a second optical performance test on the at least one optical coupler. In some embodiments, at least one optical connector optically couples the optical testing equipment via an optical die and is coupled to at least one optical coupler. In various embodiments, the tool optical coupler is aligned with the die optical coupler before temporarily coupling the optical die to the tool.

[0009] In some embodiments, the tool is repeatedly moved, optical performance tests are repeatedly performed, and the comparison results of the optical performance tests are repeatedly performed until at least one optical coupler meets a predetermined performance value. In some embodiments, after the optical coupler meets the predetermined performance value, the optical die is permanently attached to the optical substrate.

[0010] In some embodiments, a system for assembling an optical die to an optical substrate includes a frame mechanism and a tool attached to the frame mechanism. The tool includes a mating surface for temporarily engaging the tool with the optical die and a holding means configured to temporarily couple the optical die to the mating surface. A tool optical coupler is located at the mating surface and configured to form an optical connection to the optical die when the optical die is located at the mating surface. A platform is configured to hold the optical substrate, and optical testing equipment is operatively coupled to the tool optical coupler. A controller is configured to receive input from the optical testing equipment.

[0011] In some embodiments, when the optical die is located on the optical substrate, the tool optical coupler is operatively coupled to an optical coupler formed between the optical die and the optical substrate. In various embodiments, an optical testing apparatus is configured to test the optical coupler and transmit the results to a controller. In some embodiments, the controller compares the results to a threshold and determines whether the optical die needs to be moved relative to the optical substrate. In some embodiments, the tool is a first of a plurality of tools.

[0012] In some embodiments, the plasma cleaner is configured to clean the bonding surface of the optical die with plasma. In various embodiments, the plasma cleaner is configured to clean the bonding surface of the optical substrate with plasma. In some embodiments, the controller uses a tool to apply force between the optical die and the optical substrate to fuse the optical die to the optical substrate.

[0013] To better understand the nature and advantages of this disclosure, reference will be made to the following description and accompanying drawings. However, it should be understood that each drawing is provided for illustrative purposes only and is not intended to define a limitation on the scope of this disclosure. Furthermore, as a general rule, and unless expressly contrary to the specification, elements in different drawings use the same reference numerals, and these elements are generally identical or at least similar in function or purpose. Attached Figure Description

[0014] Figure 1 This is a simplified top plan view of an optical component according to an embodiment of the present disclosure;

[0015] Figure 2 yes Figure 1 The diagram shows a simplified cross-sectional view of the optical die during assembly onto the optical substrate.

[0016] Figure 3 A simplified cross-sectional view of an optical die according to an embodiment of the present disclosure during assembly to an optical substrate is shown;

[0017] Figure 4 A simplified cross-sectional view is shown when the optical die is aligned with the tool according to an embodiment of the present disclosure;

[0018] Figure 5 It shows Figure 4 The diagram shows a simplified cross-sectional view of the optical die during assembly onto the optical substrate.

[0019] Figure 6 A simplified plan view of an optical die according to an embodiment of the present disclosure is shown, the optical die including one or more features that enable optimal alignment of the optical die with an optical substrate;

[0020] Figures 7A to 7C A simplified left partial view of a tool including different types of tool optical couplers according to an embodiment of the present disclosure is shown;

[0021] Figure 8 A simplified cross-sectional view is shown, illustrating an embodiment of the present disclosure, of a group of tool heads capable of holding multiple tools.

[0022] Figure 9 A simplified side view of an assembly machine employing one or more surface treatment systems according to an embodiment of the present disclosure is shown; and

[0023] Figure 10 The steps associated with a method for aligning an optical die with an optical substrate according to an embodiment of the present disclosure are shown. Detailed Implementation

[0024] Some embodiments of this disclosure relate to methods for optimizing the alignment of an optical die on an optical substrate. While this disclosure can be used in a variety of configurations, some embodiments are particularly applicable to optical circuits that benefit from optimized performance of an optical coupler formed between the optical die and the optical substrate, as described in more detail below.

[0025] For example, in some embodiments, one or more optical couplers are formed between the optical die and the optical substrate when the optical die is attached to the optical substrate. The optical couplers can be tested and alignment adjusted if needed before the die is permanently attached to the optical substrate. In one embodiment, an in-situ optical test device is coupled to the optical substrate to test the optical coupler. In another embodiment, a tool temporarily holding the optical die has a tool optical coupler for coupling a test device to the optical die. In some embodiments, the optical die may include features for coupling a test device to the optical coupler formed between the optical die and the optical substrate. To optimize the performance of the optical coupler, the optical die can be moved relative to the optical substrate until the desired performance of the optical coupler is obtained, after which the die can be permanently bonded to the optical substrate.

[0026] To better understand the features and aspects of optimizing the alignment of optical dies and optical substrates according to this disclosure, further context of this disclosure is provided in the following sections by discussing a specific implementation of a system and apparatus for aligning optical dies and optical substrates. These embodiments are by way of example only, and other embodiments may also use other types of systems and apparatus to optimize the alignment of optical dies and optical substrates.

[0027] Figure 1 A simplified top plan view of the optical assembly 100 is shown. Figure 1 As shown, the optical component 100 includes an optical substrate 105 to which a plurality of optical dies 110-135 are attached. In some embodiments, the optical component 100 can be used as part of a quantum computer, an Ethernet device, a communication device, or other optical system. One or more optical couplers can be formed between each optical die 110-135 and the optical substrate 105. Figure 1 (not shown), enabling optical substrates to perform optical communication between each optical die. In some embodiments, each optical die 110-135 may perform one or more optical functions, such as switching optical signals, generating optical signals, amplifying optical signals, and / or filtering optical signals.

[0028] In some embodiments, the performance specifications of the optical component 100 can benefit from the optimized performance of one or more optical couplers formed between the optical dies 110-135 and the optical substrate. In various embodiments, the performance of one or more optical couplers can be optimized by using an assembly machine to simultaneously adjust the alignment of one or more optical dies 110-135 with the optical substrate, wherein the assembly machine is operatively coupled to an in-situ testing apparatus for testing the optical performance of the optical couplers, as described in more detail below.

[0029] Figure 2 It shows Figure 1 The simplified cross-sectional view AA of the optical die 120 during assembly to the optical substrate 105 is shown. Figure 1 As shown, an assembly machine 205 (e.g., a pick-and-place machine) is connected to a tool 210 via a connector 215. The tool 210 includes a mating surface 220 for temporarily coupling the tool to an optical die 120 via a vacuum port 225. The tool 210 is positioned such that the optical die 120 is positioned adjacent to an optical substrate 105. The optical die 120 is located near the optical substrate 105 such that a first optical coupler 230a and a second optical coupler 230b are formed between the optical die 120 and the optical substrate 105, respectively. The first optical coupler 230a and the second optical coupler 230b respectively enable optical signals to pass between the optical die 120 and the optical substrate 105. In one embodiment, the first optical coupler 230a and the second optical coupler 230b are formed using thermally adiabatic (in-plane) coupling between the optical die 120 and the substrate 105, respectively; however, other embodiments may use different optical coupling structures, as described in more detail below.

[0030] like Figure 2 Further shown, the optical substrate 105 includes a first waveguide 235a that can be coupled between a first port 240a of the in-situ test device 245 and a first optical coupler 230a. In some embodiments, test connectors 233a and 233b can be used to couple the in-situ test device 245 to the optical substrate 105. In some embodiments, the test connectors 233a and 233b are edge-coupled, while in other embodiments, they can be thermally adiabatic (in-plane), out-of-plane (e.g., grating), or other types of optical couplers. The first optical coupler 230a can couple optical signals from the first waveguide 235a to the optical die 120.

[0031] Similarly, the optical substrate 105 includes a second optical waveguide 235b, which can be coupled between a second port 240b of the in-situ test device 245 and a second optical coupler 230b. The second optical coupler 230b can couple an optical signal from the second waveguide 235b to the optical die 120. In some embodiments, the optical die 120 may include a die waveguide 250 coupling a first optical coupler 230a to the second optical coupler 230b. In various embodiments, the optical die 120 may include features for modifying and / or manipulating the coupled optical signal.

[0032] Assembly machine 205 can be used in conjunction with in-situ testing equipment 245, which performs optical tests on the first optical coupler 230a and the second optical coupler 230b respectively during assembly using optical substrate 105. More specifically, in some embodiments, assembly machine 205 adjusts the position of optical die 120 relative to optical substrate 105 to optimize the optical signal loss and / or distortion of the first optical coupler 230a and the second optical coupler 230b respectively, as shown by in-situ testing equipment 245. In some embodiments, the tests performed by in-situ testing equipment 245 may include: insertion loss, return loss, optical time domain reflectometry (OTDR), and / or power loss of the first optical coupler 230a and the second optical coupler 230b, etc. In some embodiments, in addition to rotating (e.g., θ) the optical die 120, the assembly machine 205 can also move the optical die 120 in the east-west (e.g., X), south-north (e.g., Y), and up-down (e.g., Z) directions to optimize the performance of the first optical coupler 230a and the second optical coupler 230b, respectively.

[0033] exist Figure 2 In the illustrated embodiment, the optical die 120 is thermally coupled to the optical substrate 105; however, other coupling configurations may also be used, as described in more detail below. In some embodiments, the optical die 120 may remain in contact with the optical substrate 105 to form a temporary first optical coupler 230a and a second optical coupler 230b, respectively, but there is no sufficient force to permanently attach the optical die to the optical substrate. To optimize the performance of the first optical coupler 230a and the second optical coupler 230b, respectively, the optical die 120 may be moved while in contact with the optical substrate 105, or the optical die may be raised (e.g., moved in the Z direction) without contact with the optical substrate, moved (e.g., in the X, Y, and / or θ directions), and then lowered back to contact with the optical substrate to perform further in-situ testing.

[0034] In a further embodiment, during in-situ testing, the optical die 120 may be held above the optical substrate 105 with a small gap. In some embodiments, the gap between the optical die 120 and the optical substrate 105 may be between 25 micrometers and 0.05 micrometers, and in a further embodiment, the gap may be between 10 micrometers and 0.1 micrometers.

[0035] As the optical die 120 is "adjusted" (e.g., moved in X, Y, and / or θ) relative to the optical substrate 105, the in-situ testing device 245 monitors one or more optical characteristics of the first optical coupler 230a and the second optical coupler 230b formed between the optical die 120 and the optical substrate 105. In some embodiments, the in-situ testing device 245 is operatively coupled to an assembly machine 205 such that the assembly machine can optimize the optical alignment of the first optical coupler 230a and the second optical coupler 230b, respectively. In various embodiments, the assembly machine 205 may use one or more algorithms to minimize the time required for optimal alignment of the optical die 120 on the optical substrate 105. For example, in one embodiment, a correlation may be developed such that when the in-situ testing device 245 identifies a relatively high return loss at a particular wavelength, this indicates that the first optical coupler 230a needs improved north-south alignment, and when it identifies a high insertion loss over a wide wavelength range, this indicates that the first optical coupler 230a and the second optical coupler 230b need improved alignment in the east-west direction, respectively. This algorithm can be used to minimize the number of alignment adjustments performed to achieve the required optical coupler performance.

[0036] In some embodiments, the assembly machine 205 can monitor and control the amount of force applied between the optical die 120 and the optical substrate 105. In one embodiment, during alignment, a limited amount of force can be applied to the optical die 120 such that the optical die does not permanently attach to the optical substrate 105, for example, when using fusion splicing. In other embodiments, the assembly machine 205 can modulate the force applied between the optical die 120 and the optical substrate 105 such that the first optical coupler 230a and the second optical coupler 230b each perform above a minimum threshold (e.g., minimum return loss). The modulated force can be used to accommodate surface defects between the optical die 120 and the optical substrate 105, allowing all optical couplers to be tested on an equal basis.

[0037] In some embodiments, a fusion bonding process can be used to attach the optical die 120 to the optical substrate 105, which atomically bonds the optical die to the optical substrate. Fusion bonding can be used when the optical die 120 and the optical substrate 105 each have prepared bonding surfaces and sufficient force is applied between the optical die and the optical substrate, as described in more detail below.

[0038] In some embodiments, the optical die 120 may be attached to the optical substrate 105 using adhesives, epoxy resins, glues, or other binders. In one embodiment, a UV-curable adhesive is pre-applied to the optical die 120, the optical die is aligned such that the first optical coupler 230a and the second optical coupler 230b have optimized performance, and the assembly is then exposed to UV light to secure the optical die in place. In other embodiments, rapid curing or other post-alignment curing processes may be used. In another embodiment, the assembly machine 205 may determine the optimal X, Y, and θ positions of the optical die 120, record these positions, move the optical die to one side, apply binder to the optical substrate 105 and / or the optical die, and then replace the optical die at the determined X, Y, and θ positions for permanent attachment.

[0039] In some embodiments, instead of aligning and attaching a single optical die, any of the alignment and bonding processes described above can be used to align and attach an optical wafer or a portion of an optical wafer to an optical substrate. In further embodiments, more than one in-situ testing device can be used, and two, three, four, or more optical signals can be simultaneously coupled to an optical die or optical substrate to optimize the optical alignment and optical performance of one or more optical couplers.

[0040] like Figure 2 As shown, adiabatic coupling is used to form the first optical coupler 230a and the second optical coupler 230b, respectively. Those skilled in the art who benefit from this disclosure will recognize many variations, modifications, and alternative designs of the optical coupler. For example, Figure 2 The illustrated configuration allows for the use of any evanescent type of optical coupler between the optical die and the optical substrate. To form an evanescent optical coupler, optical waveguides in the optical die are positioned adjacent to optical waveguides in the substrate, such that an evanescent field generated by one waveguide excites a wave in the other waveguide. In other embodiments, grating-type, edge-coupled, or other types of optical couplers can be formed between the optical die 120 and the optical substrate 105, as described in more detail below.

[0041] Figure 3 It shows something similar to Figure 2 The embodiments shown are examples, however, in Figure 3 In the first optical coupler 330a and the second optical coupler 330b, a grating-type coupler is used. Figure 3As shown, the first pair of gratings 305a and 305b can be formed on the optical die 310, and the second pair of gratings 315a and 315b can be formed on the optical substrate 335. The first pair of gratings 305a and 305b and the second pair of gratings 315a and 315b can be used to couple light energy between the optical die 310 and the optical substrate 335, respectively. In another embodiment, only the first pair of gratings 305a and 305b can be used, while in another embodiment, only the second pair of gratings 315a and 315b can be used.

[0042] like Figure 3 As further shown, in this embodiment, grating-type couplers are used to form test connectors 340a and 340b. More specifically, one or more grating-type features 345a and 345b formed on an optical substrate are used to connect the in-situ test device 245 (see [link to documentation]). Figure 2 It is coupled to the optical substrate 335.

[0043] Figure 4 It shows something similar to Figure 2 The embodiments shown are examples, however, in Figure 4 In, replacing such as Figure 2 The in-situ testing equipment shown is coupled to the optical substrate; in-situ testing equipment 245 (see...) Figure 2 It is coupled to the optical die 405 via tool 410. (e.g.) Figure 4 As shown, tool 410 includes optical connectors 415a and 415b, which can be used to connect in-situ testing equipment 245 (see...). Figure 2 Optical couplers 420a and 420b are coupled to the optical die 425, which optically couples the tool 410 to the optical die 425. In some embodiments, the optical couplers 415a and 415b may be terminated optical fibers or other types of optical couplers. The tool optical couplers 420a and 420b may be optical waveguides, optical fibers, or other types of optical couplers, some of which will be described in more detail below. In some embodiments, when the tool 410 contacts the optical die 425, the tool optical couplers 420a and 420b form an optical connection with the optical die 425, enabling the in-situ testing equipment to communicate optically with the optical die. In some embodiments, the performance of the tool optical couplers 420a and 420b can be improved by adjusting the position of the tool 410 relative to the optical die 425, using an alignment method similar to that described above for in-situ testing equipment.

[0044] In another embodiment, optical connectors 415a and 415b can be formed by holding the terminated fiber in place to form tool optical couplers 420a and 420b. In a further embodiment, optical connectors 415a and 415b can be integrated into the fiber and grating structure (…). Figure 4The terminated fiber connection is formed between (not shown in the diagram), and the tool optical couplers 420a and 420b may be the bottom of the adjacent interface surface of the grating structure. In another embodiment, the tool optical couplers 420a and 420b may be formed using an evanescent type coupler, an adiabatic type coupler, an edge type coupler, or any other optical coupling mechanism, some of which will be described in more detail below.

[0045] In some embodiments, the optical die 425 may include one or more optical paths 430 that allow optical signals to pass through the die, thereby enabling in-situ testing equipment to perform insertion loss or other tests on the tool optical couplers 420a, 420b, as described in more detail below. In other embodiments, the optical die 425 may have one or more reflective features that allow optical signals to be injected into and reflected within the die for analysis by the in-situ testing equipment, thereby optimizing the optical alignment of the tool optical couplers 420a, 420b. In further embodiments, optimal optical alignment of the tool optical couplers 420a, 420b may not be performed, and mechanical and / or image-assisted alignment of the tool 410 with the optical die 425 may be used only.

[0046] In some embodiments, the optical die 425 may be tested by an in-situ testing device using tool 410 to determine one or more characteristics of the optical die. In some embodiments, the in-situ testing device may determine whether the optical die 425 is the correct die for a particular assembly operation (i.e., die verification). In other embodiments, the in-situ testing device may perform tests on the optical die 425 to determine whether the optical die has appropriate performance characteristics (e.g., a process that may be referred to as known good die testing).

[0047] Figure 5 This shows the alignment of the tool with the optical die 425. Figure 4 The tool 410 and optical die 425 are in the process of assembling the optical die onto the optical substrate 505. For example... Figure 5 As shown, tool 410 is aligned with optical die 425, and assembly machine 205 (see...) Figure 2 An optical die is positioned near the top surface 510 of an optical substrate 505 to form optical couplers 515a and 515b between the optical die and the optical substrate. In some embodiments, the optical die 425 may have features enabling optical signals to be coupled from the tool 410 through the optical die 425 to the optical substrate 505 and back to the in-situ test equipment. These features enable the in-situ test equipment to test and optimize the alignment of the optical couplers 515a and 515b formed between the optical die 425 and the optical substrate 505. These and other features will be described in more detail below.

[0048] In some embodiments, it is advantageous to couple an in-situ test device to an optical die 425 via a tool 410 compared to coupling an optical test device to an optical die via an optical substrate. In one embodiment, using the tool 410 as an optical coupler eliminates the additional time and complexity of connecting the in-situ test device to the optical substrate 505. By using tool optical connectors 415a, 415b, the tool optical couplers 420a, 420b can be formed “automatically” because the tool must contact the optical die 425 to pick up the optical die for placement on the optical substrate 505. Furthermore, by coupling the in-situ test device to the optical couplers 515a, 515b via the optical die 425, the optical signal from the in-situ test device is generally physically closer to the optical coupler, which can result in improved test accuracy compared to coupling the in-situ test device to the optical substrate 505 at a connection point that may be physically far from the optical coupler.

[0049] In a further embodiment, the optical die 425 may have features enabling optical signals to be coupled from the tool 410 and to the optical substrate 505. As an example, in one embodiment, an optical signal can be coupled from the in-situ testing device via the tool 410, via the optical die 425, via the optical substrate 505, and from the substrate to the in-situ testing device. Individual optical signals can be coupled from the in-situ testing device via the optical substrate 505, via the optical die 425, and back via the substrate, or via the optical die and via the tool.

[0050] Figure 6 An embodiment of an optical die 600 including one or more features, said one or more features, is shown, which enable the optical die to be optimally aligned with an optical substrate by one or more of the methods described above. Figure 6 As shown, the optical die 600 has first waveguide features 605a…605d, which enable optical signals to travel from a tool (e.g., Figure 5 The tool 410 shown is transmitted via the optical die 600 to the optical substrate (e.g., Figure 5 The optical substrate 505 is shown. More specifically, each first waveguide feature 605a…605d includes a first coupler 610a…610d, which is coupled to a tool optical coupler (e.g., a tool optical coupler). Figure 5 The tool optical couplers 420a, 420b shown couple the optical die 600 to the tool 410. Each first waveguide feature 605a…605d also includes a corresponding second coupler 620a…620d, which couples the optical die 600 to an optical substrate (e.g., an optical substrate). Figure 5The optical substrate 505 shown. Each first waveguide feature 605a…605d includes a corresponding first waveguide 615a…615d that couples each first coupler 610a…610d to each corresponding second coupler 620a…620d.

[0051] like Figure 6 As further shown, the optical die 600 may also have one or more second waveguide features 625a, 625b, which enable optical signals to travel from the optical substrate (e.g., an optical substrate). Figure 2 The optical substrate 105 shown is transmitted via an optical die (e.g., Figure 2 The optical die 120 shown transmits and returns to the optical substrate. More specifically, each second waveguide feature 625a, 625b includes a third coupler 630a, 630b, which, via an optical coupler (e.g., ... Figure 2 The optical coupler 230a shown couples the optical die 120 to the substrate 105. Each second waveguide feature 625a, 625b also includes a corresponding fourth coupler 635a, 635b, which uses an optical coupler (e.g., Figure 2 The optical coupler 230b shown couples the optical die 120 to the optical substrate. Each second waveguide feature 625a, 625b includes a corresponding second waveguide 640a, 640b that couples each third coupler 630a, 630b to each corresponding fourth coupler 635a, 635b.

[0052] Figures 7A to 7C A simplified left-hand partial view shows a tool comprising different types of optical couplers for forming optical connections to an optical die. (See image.) Figure 7A As shown, in one embodiment, tool 705 includes an optical fiber 710 coupled to an optical die 715 via one or more lenses 720. One or more lenses 720 can be used to focus light energy emitted from the optical fiber 710 onto a region (e.g., a grating region) of the optical die 715 to form a tool optical coupler 725. In other embodiments, one or more lenses 720 can be used to focus light energy emitted from the optical die onto a region of the optical fiber 710. In a further embodiment, one or more optical lenses 720 can be reversed such that signals transmitted from a relatively small region of the optical fiber 710 and / or the optical die 715 can be extended to a relatively large region. In some embodiments, more than one lens can be used to achieve the desired shape and / or quality of the emitted beam.

[0053] like Figure 7BAs shown, in one embodiment, the pickup tool 730 includes an optical fiber 735 coupled to the optical die 740 via a first grating 745a and a second grating 745b, respectively. Figure 7B As shown, a first grating 745a can be optically coupled to an optical fiber 735, and a second grating 745b can be optically coupled to an optical die 740. The first grating 745a and the second grating 745b can respectively transmit optical signals between them to form a tool optical coupler 750. In one embodiment, the first grating 745a can be eliminated, and the optical fiber 735 can be optically connected to the second grating 745b on the optical die 740. In another embodiment, the second grating 745b can be eliminated, and the optical die 740 can be optically connected to the first grating 745a.

[0054] like Figure 7C As shown, in one embodiment, tool 755 includes optical fiber 760, which is coupled to optical die 765 via an adiabatic or evanescent optical coupler 770. Figure 7C As shown, the tool optical coupler 770 may include a mirror or other structure that parallels the optical signal to the optical die 765, enabling thermally adiabatic and / or evanescent coupling between the tool 755 and the optical die 765. The optical die 765 includes a coupling element 775, such as a waveguide or other structure that couples optical energy to a tool coupling element 780 forming the tool optical coupler 770. As those skilled in the art will understand from this disclosure, other types of optical coupling can be performed between the tool and the optical die, and between the optical die and the optical substrate.

[0055] Figure 8 An embodiment of a group head 805 according to an embodiment of the present disclosure is shown, which can be attached to an assembly machine 205 (see [link]). Figure 2 It also includes three separate pick-and-place tools 810a, 810b, and 810c that can maintain three separate optical dies 815a, 815b, and 815c. (For example...) Figure 8 As shown, each tool 810a, 810b, and 810c is similar to Figure 4 The tool 410 shown, however, in this embodiment, the three tools 810a, 810b, 810c are part of a group head 805. The group head 805 includes three independent mechanisms that enable each tool 810a, 810b, 810c to hold and independently move the individual optical dies 815a, 815b, 815c.

[0056] In some embodiments, tools 810a, 810b, and 810c may be provided by assembly machine 205 (see [link]). Figure 2The main frame mechanism moves to perform relatively long movements across a working area, such as from a wafer (e.g., a pick-up area) to an optical substrate (e.g., a placement area). To perform relatively short movements, such as optimizing the alignment of optical couplers, as described more in detail above, each tool 810a, 810b, 810c may be attached to a sub-stage capable of independently moving each optical die. In some embodiments, each sub-stage can move each corresponding tool 810a, 810b, 810c independently in the east-west (e.g., X) and north-south (e.g., Y) directions, in addition to rotation (e.g., θ). Thus, each optical die 815a, 815b, 815c can move independently of each other, for example, during the alignment and performance optimization of the optical couplers formed between each optical die and the optical substrate. In some embodiments, the grouping head 805 can improve the assembly machine 205 (see [link to assembly machine]) by grouping pick-ups (e.g., simultaneously or substantially simultaneously), grouping movements, and grouping placement of multiple optical dies. Figure 2 The production volume of the group head 805. Those skilled in the art will understand that, in other embodiments, the group head 805 may have two, three, four, or any number of independently maneuverable tools 810a, 810b, 810c.

[0057] Figure 9 A simplified partial view of an assembly machine 900 employing one or more surface treatment features according to an embodiment of the present disclosure is shown. Figure 9 As shown, in some embodiments, it is desirable to form a fusion between the optical die 605 and the optical substrate 610 to optimize the performance of the optical coupler formed between the optical die and the optical substrate. In some embodiments, a first in-situ plasma cleaner 615 may be used to clean the bonding surface 620 of the optical die 605 using a first plasma flow 625. In various embodiments, the first in-situ plasma cleaner 615 may be moved across the entire bonding surface 620 of the optical die 605 while the optical die is held by the tool 630.

[0058] In some embodiments, a second in-situ plasma cleaner 635 can pass through the entire bonding surface 640 of the optical substrate 610 in the area of ​​the optical die 605 to be welded. After plasma cleaning of the optical die 605 and the optical substrate 610 is completed, the optical die can be positioned to contact the optical substrate, but without sufficient force for welding to occur. During this period, feedback can be transmitted to the assembly machine 900 using an in-situ optical testing device to optimize the optical alignment of the optical die 605 and the optical substrate 610. Once optimal alignment is achieved, the assembly machine 900 can increase the force between the optical die 605 and the optical substrate 610 to induce welding. In some embodiments, additional heat and / or ultrasonic motion can be applied to the optical die 605 and / or the optical substrate 610 to form a weld.

[0059] Those skilled in the art who benefit from this disclosure will recognize numerous variations, modifications, and substitutions. In some embodiments, the optical substrate may include the ability and / or intelligence to perform its own tests without the use of external in-situ testing equipment. More specifically, in some embodiments, the optical substrate (and associated optical components) is capable of generating optical test signals, evaluating the coupling between the die and the substrate, and reporting the results to the assembly machine via optical, direct electrical, or indirect wireless methods. Therefore, in some embodiments, some or all of the in-situ testing equipment may not be required. In other embodiments, integrated testing capabilities may be used in conjunction with in-situ testing equipment.

[0060] In a further embodiment, the optical die may include a first set of optical features and a second set of optical features, the first set of optical features being used to optimize the alignment of the optical coupler, and the second set of optical features forming a functionalized optical coupler for operation of the final optical circuitry. In one embodiment, the first set of grating-type optical coupler features may be used to optimize the optical alignment of the optical die with the optical substrate, while the second set of grating-type optical coupler features may be used to functionally couple the optical die to the optical substrate. In various embodiments, the same type of optical features used for alignment can be used for in-circuit operation, thus taking into account similar manufacturing and process variations during alignment. However, in other embodiments, different types of optical couplers may be used for both alignment and in-circuit operation.

[0061] Figure 10 The steps associated with a method 1000 for aligning an optical die with an optical substrate according to an embodiment of this disclosure are shown. Figure 10 As shown, in step 1005, an optical die is provided. In some embodiments, the optical die may have one or more optical functions, such as a light source, a filter, a beam splitter, an optical amplifier, or other functions.

[0062] In step 1010, the optical die is temporarily coupled to a tool of the assembly machine. In some embodiments, the assembly machine is a pick-and-place machine, wherein the tool is attached to a rack mechanism of the machine. In some embodiments, the tool uses a vacuum port to temporarily secure the optical die to the tool. In a further embodiment, the tool may have one or more tool optical couplers aligned with optical features on the optical die to facilitate testing and alignment of the optical die and substrate, as described in more detail herein.

[0063] In step 1015, an optical substrate is provided. In some embodiments, the optical substrate is held on a work platform of an assembly machine that can be accessed by a rack mechanism. In some embodiments, the optical substrate is configured to receive a plurality of optical dies and interconnect with each optical die.

[0064] In step 1020, the optical die is positioned on the optical substrate using a tool. In some embodiments, when the optical die is positioned on the optical substrate, one or more optical couplers are formed between the optical die and the optical substrate. The optical die may be temporarily placed on or near the optical substrate to form the optical coupler.

[0065] In step 1025, the optical testing equipment may be in-situ (e.g., integrated within an assembly system) and configured to test optical couplers. In one embodiment, the testing equipment is operatively coupled to an optical substrate and tests the optical coupler. In another embodiment, the testing equipment is operatively coupled to a tool via a tool optical coupler that is coupled through an optical die to an optical coupler formed between the optical die and the optical substrate. The testing equipment may perform one or more optical tests on the optical coupler and transmit the results to the assembly machine.

[0066] In step 1030, the test results are evaluated against a predetermined threshold (e.g., a performance standard). In some embodiments, the performance standard is the minimum acceptable performance of the optical coupler. If the optical coupler does not meet the performance standard, the assembler moves the optical die relative to the optical substrate and returns to step 1025 for further testing. This sequence can be repeated until the optical coupler meets the performance standard. In this way, the alignment of the optical die can be optimized so that the optical coupler meets the minimum standard.

[0067] In step 1040, the optical coupler has met performance standards, and the optical die is then permanently attached to the optical substrate while maintaining optimized alignment. In some embodiments, fusion splicing is used to attach the optical die; however, in other embodiments, other types of bonding may be performed.

[0068] It should be understood that Method 1000 is illustrative and can be varied and modified. The steps described sequentially can be performed in parallel, the order of the steps can be changed, and steps can be modified, combined, added, or omitted.

[0069] In the foregoing description, embodiments of this disclosure have been described with reference to several specific details, which may vary between different implementations. Therefore, the specification and drawings are to be considered illustrative rather than restrictive. The unique and exclusive indication of the scope of this disclosure, and the scope intended to be protected by this disclosure, is the literal and equivalent scope of the claims issued in this application, issued in a particular form, including any subsequent amendments. Specific details of particular embodiments may be combined in any suitable manner without departing from the spirit and scope of the embodiments of this disclosure.

[0070] Additionally, spatially relative terms, such as “bottom” or “top,” may be used to describe the relationship of an element and / or feature to other elements and / or features, as illustrated in the figures. It should be understood that spatially relative terms are intended to include different orientations of the device in use and / or operation other than those shown in the figures. For example, if the device in the figures is flipped, an element described as the “bottom” surface may be oriented “above” other elements or features. The device may also be oriented in other ways (e.g., rotated 90 degrees or in other directions) and may be interpreted accordingly by the spatially relative descriptors used herein.

Claims

1. A tool for an assembly machine, the tool comprising: A connector for connecting the tool to the assembly machine; A mating surface, which is used to temporarily engage the tool with the optical die; A holding device configured to temporarily couple the optical die to the mating surface; and A first tool optical coupler and a second tool optical coupler, wherein the first tool optical coupler is located at the mating surface and is configured to form a first optical connection with the optical die when the optical die is located at the mating surface, and the second tool optical coupler is located at the mating surface and is configured to form a second optical connection with the optical die when the optical die is located at the mating surface; Optical substrate, comprising: A first waveguide, optically coupled to the first tool optical coupler and edge-coupled to a first test connector, the first test connector being coupled to a first port of the test device; and The second waveguide is optically coupled to the second tool optical coupler and edge-coupled to the second test connector, which is coupled to the second port of the test device.

2. The tool according to claim 1, wherein, One of the first tool optical coupler or the second tool optical coupler is a terminated optical fiber.

3. The tool according to claim 1, wherein, The first tool optical coupler or the second tool optical coupler is a thermally insulating coupler that is coupled to the first waveguide or the second waveguide, respectively.

4. The tool according to claim 1, wherein, The optical die includes a die waveguide.

5. The tool according to claim 1, wherein, The holding device is a vacuum port that applies a vacuum to the optical die to temporarily couple the optical die to the mating surface.

6. A method for aligning an optical die with an optical substrate, the optical substrate comprising a waveguide, the method comprising: Temporarily couple the optical die to the tool; The tool is positioned such that the optical die is located on the surface of the optical substrate, so as to form at least one tool optical coupler between the waveguide of the optical substrate and the optical die; The test connector edge is coupled to the waveguide of the optical substrate to optically couple the test connector to the at least one tool optical coupler; Perform a first optical performance test on the at least one tool optical coupler; Move the tool so that the optical die moves relative to the optical substrate; After the tool is moved, a second optical performance test is performed on the optical coupler of at least one tool. as well as The results of the first optical performance test are compared with the results of the second optical performance test.

7. The method according to claim 6, wherein, The optical substrate includes a second waveguide, and performing the first optical performance test includes coupling the edge of the second test connector to the second waveguide of the optical substrate.

8. The method according to claim 6, wherein, The tool includes at least one optical connector, which enables the optical testing equipment to perform the first optical performance test and the second optical performance test of the at least one tool optical coupler.

9. The method according to claim 8, wherein, The at least one optical connector is optically coupled to the optical testing equipment via the optical die and to the at least one tool optical coupler.

10. The method according to claim 6, wherein, Before temporarily coupling the optical die to the tool, align the tool optical coupler with the die optical coupler.

11. The method according to claim 6, wherein, The tool is repeatedly moved, the optical performance test is repeatedly performed, and the comparison results of the optical performance test are repeatedly performed until the at least one tool optical coupler meets the predetermined performance value.

12. The method according to claim 11, wherein, After at least one tool optical coupler meets the predetermined performance value, the optical die is permanently attached to the optical substrate.

13. A system for assembling an optical die onto an optical substrate, the system comprising: Frame mechanism; A tool, which is attached to the frame mechanism and includes: A mating surface for temporarily engaging the tool with the optical die; A holding device configured to temporarily couple the optical die to the mating surface; and A first tool optical coupler is located at the mating surface and configured to form a first optical connection with the optical die when the optical die is located at the mating surface; A second tool optical coupler is located at the mating surface and configured to form a second optical connection with the optical die when the optical die is located at the mating surface; A platform configured to hold the optical substrate, wherein the optical substrate comprises: A first waveguide, which is optically coupled to the first tool optical coupler and edge-coupled to the first test connector; The second waveguide is optically coupled to the second tool optical coupler and edge-coupled to the second test connector; An optical testing device, operatively coupled to the first waveguide and the first tool optical coupler via the first test connector, and operatively coupled to the second waveguide and the second tool optical coupler via the second test connector; and A controller is configured to receive input from the optical testing equipment and compare the results generated by the optical testing equipment.

14. The system according to claim 13, wherein, The first tool optical coupler is a terminated optical fiber.

15. The system according to claim 14, characterized in that, The optical testing equipment is configured to test the first tool optical coupler and the second tool optical coupler and transmit the results to the controller.

16. The system according to claim 15, wherein, The controller compares the result with a threshold and determines whether the optical die needs to be moved relative to the optical substrate.

17. The system according to claim 13, wherein, The tool in question is the first of a group of tools.

18. The system according to claim 13, wherein, It also includes a plasma cleaner configured to plasma clean the bonding surfaces of the optical die.

19. The system according to claim 13, wherein, It also includes a plasma cleaner configured to plasma clean the bonding surface of the optical substrate.

20. The system according to claim 13, wherein, The controller uses the tool to apply force between the optical die and the optical substrate to fuse the optical die to the optical substrate.

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