An optical packaging platform and method for silicon photonic chips

Abstract

The application discloses an optical packaging platform and method for a silicon photon chip, and the optical packaging platform comprises a base plate, a gantry, a slide rail, a viewing mirror set, two electrically-controlled displacement tables, a clamp for fixing an optical fiber array, a curved rod and a PCB plate, wherein the gantry and the two electrically-controlled displacement tables are installed on the base plate, the slide rail is installed on the gantry, the viewing mirror set comprises a first optical zoom lens, a second optical zoom lens, a third optical zoom lens and a fourth optical zoom lens, the first optical zoom lens and the fourth optical zoom lens are installed on the slide rail, the second optical zoom lens and the third optical zoom lens are oppositely arranged and installed on the base plate, the curved rod is used for connecting the electrically-controlled displacement tables and the clamp, the PCB plate is installed on the base plate through a support, the PCB plate is installed with a chip, a ceramic sheet and an adapter plate, and the chip is located below the adapter plate. The operation of the application is simpler, the optical packaging process can be more automated and stable, and the packaging time can be shortened.

Description

Technical Field

[0001] This invention relates to the field of optical packaging of integrated circuits, and more particularly to an optical packaging platform and method for silicon photonic chips. Background Technology

[0002] As an indirect-gap semiconductor, silicon provides very low direct-gap recombination for diode laser emission. Therefore, the optical signal required to drive Si photonics must originate from an external laser source, either indirectly (i.e., fiber coupling from discrete laser devices) or directly (i.e., hybrid / heterogeneous integration of IIIV devices / materials on SiPIC). Optical packaging describes the series of technologies and capabilities required for optical connections between the PIC and external components. Large-scale silicon-based optical switching chips, with their advantages of low power consumption, high performance, and low cost, are becoming potential candidates for switching nodes in next-generation high-performance computers, data centers, and communication networks. Electrical and optical packaging of the chip are essential processes for the operation of silicon-based optical switching chips. Due to limitations in chip exposure area, as the scale of silicon-based optical switching chips continues to increase, the number and density of on-chip optical and electrical ports also increase significantly. Limited by equipment and manufacturing processes, directly packaging the on-chip optical and electrical ports has become increasingly difficult. External lasers have numerous applications for indirect and direct coupling with PICs (Photonic Integrated Circuits). Each method can be further subdivided based on the coupling scheme employed, such as grating coupling, edge coupling, and evanescent coupling. In grating coupling, fiber optic arrays are widely used, typically employing manual, multiple dispensing methods to fix the fiber optic array to the chip for coupling. This process usually introduces significant additional losses. Therefore, a more automated and time-efficient packaging method is needed. Furthermore, limitations in existing fiber optic array manufacturing processes result in low yields for large-channel fiber optic arrays, and the excessive mass of large-channel fiber optic arrays makes them difficult to fix. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by providing an optical packaging platform and method for silicon photonic chips.

[0004] The objective of this invention is achieved through the following technical solution: A first embodiment of this invention provides an optical packaging platform for silicon photonic chips, the optical packaging platform comprising:

[0005] substrate;

[0006] A gantry frame is mounted on the base plate;

[0007] A slide rail is installed above the gantry frame;

[0008] The observation lens assembly includes a first optical magnifying lens, a second optical magnifying lens, a third optical magnifying lens, and a fourth optical magnifying lens. The first and fourth optical magnifying lenses are mounted on the slide rail, and the second and third optical magnifying lenses are mounted opposite each other on the substrate.

[0009] Two electrically controlled displacement stages are mounted on the base plate;

[0010] Fixtures are used to secure fiber optic arrays.

[0011] A curved rod, used to connect the electrically controlled displacement stage and the clamp, is provided with a first connecting portion; and

[0012] A PCB board is mounted on the substrate via a bracket. The PCB board has a chip, a ceramic plate, and an adapter board mounted on it, with the chip located below the adapter board.

[0013] Optionally, the optical magnification of the first, second, third, and fourth optical magnifying lenses is 0.7X-4.5X, and the zoom ratio is 6.5:1.

[0014] Optionally, a pool-shaped block is also mounted on the PCB board, and the pool-shaped block is cured onto the ceramic sheet with a curing adhesive.

[0015] Optionally, the pool-shaped block has a closed structure and is provided with a first stop, two protrusions, two second stop and a third stop. The two protrusions are provided at both ends of the first stop, and the two ends of the first stop are respectively connected to one end of the two second stop. The two ends of the third stop are respectively connected to the other end of the two second stop.

[0016] Optionally, the bump abuts against the side of the chip, and the lower surface of the bump abuts against the upper surface of the adapter plate;

[0017] The first stop portion abuts against the upper surface of the adapter plate;

[0018] The inner side of the second stop portion abuts against the surface of the ceramic sheet;

[0019] The third stop is located above the ceramic sheet, and the lower surface of the third stop abuts against the upper surface of the ceramic sheet.

[0020] Optionally, the fixture includes a main body with a groove, the top of the main body is mounted on a first connecting part, and a fastening plate is fixedly provided at the lower end of the main body with a plurality of positioning holes.

[0021] Optionally, the clamp includes a main body and a clamping block. The main body is provided with a groove, and the lower end of the main body is provided with a mounting base. The clamping block is mounted on the mounting base by studs.

[0022] Optionally, the first connecting portion is provided with a connecting seat, the connecting seat is installed at the top of the groove, and the outer surface of the connecting seat abuts against the inner surface of the groove; and / or,

[0023] The clamp also includes a support block located between the ceramic sheet and the clamping block.

[0024] A second embodiment of the present invention provides an optical packaging method based on the above-described optical packaging platform for silicon photonic chips, the optical packaging method comprising the following steps:

[0025] (1) Manually adjust the position, magnification, and focal length of the first, second, third, and fourth optical magnifying lenses on the three axes xyz to capture the field of view of the fiber array in the three directions xyz.

[0026] (2) The electrically controlled displacement stage adjusts the clamps used to fix the fiber array in six dimensions so that each fiber in the fiber array is aligned with the grating on the chip surface.

[0027] (3) Connect an optical power meter to the last fiber of the fiber array to monitor the coupling loss of the fiber array.

[0028] (4) When the optical power meter detects that the coupling loss of the fiber array has reached the minimum value, the fiber array is raised along the z-axis by adjusting the clamps of the electrically controlled displacement stage.

[0029] (5) Apply curing adhesive evenly at the grating position on the chip surface, and control the thickness of the curing adhesive to 0.5 mm;

[0030] (6) Use the electrically controlled displacement stage to adjust the clamp and slowly move the fiber array downward along the z-axis to reset it to its original position, so that the curing adhesive fills the gap between the fiber array and the grating.

[0031] (7) The position of the fiber array is finely adjusted by adjusting the clamps using an electrically controlled displacement stage until the coupling loss value monitored by the optical power meter is minimized;

[0032] (8) Use a UV lamp to cure the part of the chip that is in contact with the fiber array to ensure that the curing adhesive is completely solidified.

[0033] (9) After curing, remove the fixture to complete the optical packaging of the silicon photonic chip.

[0034] Optionally, between step (5) and step (6), step (a) is further included: placing the pool-shaped block on the ceramic sheet of the PCB board, adding a small amount of curing adhesive to the outside of the pool-shaped block where it adheres to the ceramic sheet to fix the pool-shaped block, and filling the pool-shaped block with curing adhesive according to a preset amount using an automatic dispensing machine; and / or

[0035] Between steps (7) and (8), there is also step (b): applying curing adhesive to the ceramic sheet, placing the support block on the ceramic sheet and pushing it between the clamping block and the ceramic sheet from one side, and curing the clamping block and the support block with curing adhesive.

[0036] The beneficial effects of this invention are as follows: This invention designs an optical packaging platform, enabling simple optical packaging of silicon photonic chips; it implements a novel optical packaging method using a pool-shaped block. Compared to traditional optical packaging methods, this invention offers simpler packaging operations, a more efficient process, and requires only one dispensing and curing cycle. Furthermore, the fiber array experiences uniform stress during curing, reducing the significant additional losses caused by uneven adhesive application during manual dispensing. The entire optical packaging process is more automated and stable, contributing to shorter packaging time. A pair of asymmetric fixtures and corresponding clamping methods address the instability caused by the large mass of the large-channel fiber array and the resulting pigtail stress, ensuring stable additional losses throughout the packaging process. This method is suitable for optical packaging of large-channel silicon photonic chips. Compared to directly using an N-channel fiber array, splicing two N / 2-channel fiber arrays solves the shortcomings in the fabrication process of large-channel fiber arrays, making it easier to fix the large-channel fiber array and avoiding the low yield rate of fiber array processing during large-scale switching chip packaging. The method of splicing two multi-channel fiber arrays can achieve optical packaging of large-scale switching chips. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the grating and waveguide structure on the chip in this invention;

[0038] Figure 2 This is a schematic diagram of the optical packaging platform in Embodiment 1 of the present invention;

[0039] Figure 3 This is a front view of the optical packaging platform in Embodiment 1 of the present invention;

[0040] Figure 4 This is a top view of the optical packaging platform in Embodiment 1 of the present invention;

[0041] Figure 5 yes Figure 2 A partially enlarged structural diagram;

[0042] Figure 6 This is a three-dimensional structural diagram of the pool-shaped block in Embodiment 1 of the present invention;

[0043] Figure 7 yes Figure 6 A top view of the pool-shaped block in the middle;

[0044] Figure 8 This is a schematic diagram of the optical packaging platform in Embodiment 2 of the present invention;

[0045] Figure 9 This is a front view of the optical packaging platform in Embodiment 2 of the present invention;

[0046] Figure 10 This is a left view of the optical packaging platform in Embodiment 2 of the present invention;

[0047] Figure 11 This is a top view of the optical packaging platform in Embodiment 2 of the present invention;

[0048] Figure 12 yes Figure 8 Enlarged structural diagram of section A in the middle;

[0049] Figure 13 This is a side view of the chip, adapter board, fiber array, acrylic adapter block, and fixing block during the dispensing and curing process of Embodiment 2 of the present invention.

[0050] Figure 14 This is a schematic diagram of the fixture in Embodiment 2 of the present invention;

[0051] Figure 15 This is a front view of the fixture in Embodiment 2 of the present invention;

[0052] Figure 16 This is a left view of the fixture in Embodiment 2 of the present invention.

[0053] In the figure, the components are: substrate 1, gantry 2, slide rail 3, observation lens group, first optical magnifying lens 41, second optical magnifying lens 42, third optical magnifying lens 43, fourth optical magnifying lens 44, electrically controlled displacement stage 5, fixture 6, main body 61, groove 62, fastening plate 63, positioning hole 64, mounting base 65, clamping block 66, support block 67, crank rod 7, first connecting part 71, connecting seat 711, PCB board 8, chip 81, pool-shaped block 82, first stop part 821, protrusion 822, second stop part 823, third stop part 824, ceramic sheet 83, adapter plate 84, and fiber optic array 9. Detailed Implementation

[0054] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Rather, they are merely examples of apparatuses and methods consistent with some aspects of the invention as detailed in the appended claims.

[0055] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms “a,” “the,” and “the” used in this invention and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any or all possible combinations of one or more of the associated listed items.

[0056] It should be understood that although the terms first, second, third, etc., may be used in this invention to describe various information, this information should not be limited to these terms. These terms are only used to distinguish information of the same type from one another. For example, first information may also be referred to as second information without departing from the scope of this invention, and similarly, second information may also be referred to as first information. Depending on the context, the word "if" as used herein may be interpreted as "when," "when," or "in response to a determination."

[0057] The present invention will now be described in detail with reference to the accompanying drawings. Unless otherwise specified, the features of the following embodiments and implementations can be combined with each other.

[0058] This invention provides an optical packaging platform for silicon photonic chips.

[0059] Example 1

[0060] See Figures 2-4 The optical packaging platform in this embodiment of the invention includes a substrate 1, a gantry 2, a slide rail 3, an observation lens assembly, two electrically controlled displacement stages 5, a clamp 6, a crank 7, and a PCB board 8. The gantry 2 is mounted on the substrate 1, the slide rail 3 is fixedly mounted above the gantry 2, the two electrically controlled displacement stages 5 are mounted on the substrate 1, the clamp 6 is used to fix the fiber array 9, the electrically controlled displacement stages 5 are connected to the clamp 6 via the crank 7, and the PCB board 8 is mounted on the substrate 1 via a bracket, thus supporting the PCB board 8 on the substrate 1.

[0061] It should be understood that the two electrically controlled displacement stages 5 contain adjustment functions in six dimensions. By adjusting the electrically controlled displacement stages 5, the fiber array 9 can be aligned and coupled with the grating on the chip 81 in six dimensions.

[0062] In this embodiment, the observation lens group is used to observe the grating aperture on the surface of the fiber array 9 and the chip 81. The observation lens group includes a first optical magnifying lens 41, a second optical magnifying lens 42, a third optical magnifying lens 43, and a fourth optical magnifying lens 44. The first optical magnifying lens 41 is fixedly mounted on the slide rail 3 and is used to observe the upper field of view. The second optical magnifying lens 42 and the third optical magnifying lens 43 are mounted opposite each other on the substrate 1 and are used to observe the left and right fields of view, respectively. The second optical magnifying lens 42 and the third optical magnifying lens 43 are located on the left and right sides of the PCB board 8. The fourth optical magnifying lens 44 is mounted on the slide rail 3 and is used to observe the rear field of view.

[0063] Optionally, the first optical magnifying lens 41, the second optical magnifying lens 42, the third optical magnifying lens 43, and the fourth optical magnifying lens 44 have an optical magnification of 0.7X-4.5X and a zoom ratio of 6.5:1. For example, in this embodiment, a 6.5X continuous zoom lens VP-LZ-63106 is selected.

[0064] The packaging of the fiber optic array 9, PCB board 8, chip 81, pool-shaped block 82, and adapter board 83 falls under the category of electrical packaging, which is a relatively conventional flip-chip bonding technology. Therefore, based on this flip-chip bonding electrical packaging technology, this invention describes a method for further optical packaging, in which the package, including the fiber optic array 9, is optically packaged after the chip 81 has been electrically packaged.

[0065] In this embodiment, a chip 81, a ceramic sheet 83, and an adapter board 84 are mounted on the PCB board 8, with the chip 81 located below the adapter board 84. Additionally, a pool-shaped block 82 is also mounted on the PCB board 8, and the pool-shaped block 82 is cured onto the ceramic sheet 83 with adhesive.

[0066] Furthermore, the chip 81 and the adapter board 84 are mounted on the PCB board 8 using a flip-chip soldering process. Specifically, the adapter board 84 is bonded to the PCB board 8 with adhesive and then soldered with solder.

[0067] Furthermore, after the pool-shaped block 82 is placed in a suitable position on the PCB board 8, it is cured onto the ceramic sheet 83 with a curing adhesive.

[0068] Preferably, the curing adhesive is a UV adhesive. It should be understood that other adhesives with fixing and bonding properties can also be selected as the curing adhesive, such as quick-drying adhesives.

[0069] Preferably, the pool-shaped block 82 is made of acrylic material. It should be noted that the material of the pool-shaped block 82 should be one that allows ultraviolet light to pass through and is not easily deformed; therefore, other suitable materials can also be selected.

[0070] In this embodiment, the fiber optic array 9 is characterized by its large size. Due to its large mass, the large fiber optic array 9 experiences significant stress during encapsulation, making it susceptible to displacement during curing, which can lead to a sharp increase in coupling loss or even encapsulation failure. Therefore, when encapsulating such a large fiber optic array 9, a small amount of curing adhesive, such as UV adhesive, is typically applied to the gap between the fiber optic array 9 and the adapter plate 83 for curing. Then, curing adhesive is applied to the gap between the bottom of the fiber optic array 9 and the ceramic plate 83, and then cured. Finally, a fixing component is added behind the fiber optic array 9, and UV adhesive is applied between the fixing component and the fiber optic array 9 for curing. However, this process involves numerous steps, and each step carries the risk of uneven adhesive application, excessive or insufficient adhesive, leading to a sharp increase in coupling loss, or even direct coupling mismatch and encapsulation failure. Therefore, the present invention uses a "pool" structure, namely, a pool-shaped block 82 to solve the problem. The pool-shaped block 82 is fitted with the adapter board 83, PCB board 8, ceramic sheet 83 and chip 81. The pool-shaped block 82 is used to contain and cure the curing adhesive, realizing an optical packaging process suitable for optical switching chips.

[0071] In this embodiment, see Figures 6-7 The pool-shaped block 82 has a closed structure and is provided with a first stop 821, two protrusions 822, two second stopes 823, and a third stop 824, which together enclose the pool-shaped block 82. The two protrusions 822 are located at both ends of the first stop 821. Each end of the first stop 821 is connected to one end of each of the two second stopes 823. Each end of the third stop 824 is connected to the other end of each of the two second stopes 823. Specifically, one end of the first stop 821 is connected to one second stop 823, and another end of the first stop 821 is connected to the other second stop 823. Each end of the third stop 824 is connected to both second stopes 823.

[0072] Furthermore, such as Figure 5 As shown, the bump 822 abuts against the side of the chip 81, and the lower surface of the bump 822 abuts against the upper surface of the adapter plate 84. The bump 822 is in close contact with the chip 81 and the adapter plate 84, which can effectively prevent the UV adhesive from overflowing.

[0073] Furthermore, the first stop portion 821 abuts against the upper surface of the adapter plate 84, maintaining tight contact with each other. This effectively prevents UV adhesive from overflowing into the gap between the adapter plate 83 and the chip 81. This would cause a stress that misaligns the adapter plate 83 and the chip 81 during the curing of the UV adhesive, leading to misalignment between the fiber array 9 and the chip 81 and increased coupling loss. Additionally, this portion is relatively narrow because the chip 81 only protrudes a small distance from the adapter plate 83. The cover plate of the fiber array 9 has a certain thickness, typically between 100nm and 1mm. The width of this portion needs to be designed based on the distance from the exposed grating to the edge and the thickness of the cover plate of the fiber array 9, reserving sufficient space for the coupling of the fiber array 9 so that the fiber array 9 can be aligned with the grating on the chip 12.

[0074] Furthermore, the inner side of the second stop portion 823 abuts against the surface of the ceramic sheet 83, which can prevent the ultraviolet adhesive from seeping out.

[0075] Furthermore, the third stop portion 824 is located above the ceramic sheet 83, and the lower surface of the third stop portion 824 abuts against the upper surface of the ceramic sheet 83. The two are tightly fitted together, which can effectively prevent the ultraviolet adhesive from seeping out.

[0076] It should be noted that before adding UV adhesive to cure the fiber array 9 inside the pool-shaped block 82, a small amount of UV adhesive needs to be applied to the outside of the third junction 824 and cured first, so that it adheres to the ceramic sheet 83 to fix the position of the pool-shaped block 82, so as to prevent the UV adhesive from exerting force on the pool-shaped block 82 and causing it to shift during the subsequent curing process of applying UV adhesive inside the pool-shaped block 82.

[0077] In this embodiment, the crank 7 is provided with a first connecting part 71, which is used to connect the clamp 6.

[0078] In this embodiment, see Figure 2 and Figure 5 The fixture 6 includes a main body 61, on which a groove 62 is provided. The top of the main body 61 is mounted on the first connecting part 71, and a fastening plate 63 is fixedly provided at the lower end of the main body 61. The fastening plate 63 is provided with a plurality of positioning holes 64. The fiber optic array 9 can be accurately installed at the corresponding positions of the fastening plate 63 through the positioning holes 64.

[0079] Optionally, the fixture 6 is made of aluminum. It should be understood that the fixture 6 can also be made of other materials with high hardness, such as iron or aluminum alloy.

[0080] This invention utilizes a designed pool-shaped block 82, which is mounted on a PCB board 8, to achieve a novel optical encapsulation method. Compared to traditional optical encapsulation methods, this invention offers a simpler encapsulation operation, a more efficient process, and requires only one dispensing and curing cycle. Furthermore, the fiber array 9 experiences uniform stress during curing, reducing the significant additional losses caused by uneven glue application during manual dispensing. In addition, the entire optical encapsulation process is more automated and more stable, which helps to shorten the encapsulation time.

[0081] Example 2

[0082] See Figures 8-11 The optical packaging platform in this embodiment of the invention includes a substrate 1, a gantry 2, a slide rail 3, an observation lens assembly, two electrically controlled displacement stages 5, a clamp 6, a crank 7, and a PCB board 8. The gantry 2 is mounted on the substrate 1, the slide rail 3 is fixedly mounted above the gantry 2, the two electrically controlled displacement stages 5 are mounted on the substrate 1, the clamp 6 is used to fix the fiber array 9, the electrically controlled displacement stages 5 are connected to the clamp 6 via the crank 7, and the PCB board 8 is mounted on the substrate 1 via a bracket, thus supporting the PCB board 8 on the substrate 1.

[0083] It should be understood that the two electrically controlled displacement stages 5 contain adjustment functions in six dimensions. The electrically controlled displacement stages 5 are connected to the crank 7, and the other end of the crank 7 is connected to the clamp 6 that fixes the fiber array 9. By adjusting the electrically controlled displacement stages 5, the fiber array 9 can be aligned and coupled with the grating on the chip 81 in six dimensions.

[0084] In this embodiment, the observation lens group is used to observe the grating aperture on the surface of the fiber array 9 and the chip 81. The observation lens group includes a first optical magnifying lens 41, a second optical magnifying lens 42, a third optical magnifying lens 43, and a fourth optical magnifying lens 44. The first optical magnifying lens 41 is fixedly mounted on the slide rail 3 and is used to observe the upper field of view. The second optical magnifying lens 42 and the third optical magnifying lens 43 are mounted opposite each other on the substrate 1 and are used to observe the left and right fields of view, respectively. The second optical magnifying lens 42 and the third optical magnifying lens 43 are located on the left and right sides of the PCB board 8. The fourth optical magnifying lens 44 is mounted on the slide rail 3 and is used to observe the rear field of view.

[0085] Optionally, the first optical magnifying lens 41, the second optical magnifying lens 42, the third optical magnifying lens 43, and the fourth optical magnifying lens 44 have an optical magnification of 0.7X-4.5X and a zoom ratio of 6.5:1. For example, in this embodiment, a 6.5X continuous zoom lens VP-LZ-63106 is selected.

[0086] In this embodiment, a chip 81, a ceramic plate 83, and an adapter board 84 are mounted on the PCB board 8. The chip 81 is located below the adapter board 84, as shown below. Figure 12As shown. Additionally, chip 81 is located above ceramic plate 83, as... Figure 13 As shown.

[0087] Furthermore, the chip 81 and the adapter board 84 are mounted on the PCB board 8 using a flip-chip soldering process. Specifically, the adapter board 84 is bonded to the PCB board 8 with adhesive and then soldered with solder.

[0088] See Figures 14-16 In this embodiment, a pair of asymmetrical clamps 6 are included. The clamp 6 includes a main body 61 and a clamping block 66. A groove 62 is provided on the main body 61, and a mounting base 65 is provided at the lower end of the main body 61. The clamping block 66 is mounted on the mounting base 65 by studs.

[0089] Furthermore, the first connecting part 71 is provided with a connecting seat 711, which is installed at the top of the groove 62, and the outer surface of the connecting seat 711 abuts against the inner surface of the groove 62.

[0090] In this embodiment, as Figure 14 As shown, the mounting base 711 is embedded in the top of the groove 62, which is used to fix the fiber array. The fiber array 9 is the glass plate part of the fiber array. The fiber array 9 is bonded to the clamping block 66 with a curing adhesive such as UV adhesive, thus avoiding the direct clamping of the glass plate at the front end of the fiber array 9 by the clamp 6. The glass plate is relatively fragile and cannot withstand large pressure, so the fiber array 9 will inevitably experience significant shaking and displacement during the entire encapsulation process. The bonding surface between the clamping block 66 and the fiber array 9 is designed with a 12-degree wedge angle. This angle is determined by the coupling angle between the fiber array 9 and the grating. This design avoids the problem that insufficient spacing between the bottom of the adapter block 84 or the clamp 6 and the ceramic plate 83 or the adapter plate 84 will prevent the fiber array 9 from descending to the required height to complete coupling. For example, when the coupling angle between the fiber array 9 and the grating is 12 degrees, the wedge angle of the bonding surface between the clamping block 66 and the fiber array 9 is also 12 degrees. The coupling angle is obtained through on-chip grating simulation. The coupling angle will be different if the grating design is different.

[0091] In addition, this embodiment includes a pair of asymmetrical clamps 6, which can bring the two fiber arrays 9 as close as possible or even make them fit together, such as Figure 15 As shown, since the clamp 6 has an asymmetric structure, the optical fibers in the cladding portion of the optical fiber array 9 can fan out to one side.

[0092] Because the high-channel-count fiber array 9 has a large number of long pigtails, it has a relatively large mass and stress. Therefore, a clamping block 66 is attached to the back of the fiber array 9 using UV adhesive. The clamping block 66 provides a larger clamping force to stably control the fiber array 9.

[0093] Optionally, the fixture 6 is made of aluminum. It should be understood that the fixture 6 can also be made of other materials with high hardness, such as iron or aluminum alloy.

[0094] Optionally, the clamping block 66 is made of acrylic. It should be noted that the clamping block 66 is required to be made of a material that is light-transmitting and can be bonded to the fiber optic array 9 using a curing adhesive such as UV adhesive; therefore, acrylic is chosen in this embodiment. It should be understood that other suitable materials can also be selected.

[0095] In this embodiment, the clamp also includes a support block 67, such as Figure 13 As shown, the support block 67 is located above the ceramic sheet 83 and below the clamping block 66, and is fixed between the ceramic sheet 83 and the clamping block 66 by a curing adhesive. The support block 67 can support the two clamping blocks 66 above, thereby ensuring that the two spliced ​​fiber arrays 9 are supported upward in the z-axis direction.

[0096] This embodiment solves the instability problem caused by the stress on the pigtails due to the large mass of the large-channel fiber array 9 through a special fixture design and clamping method. This makes the additional losses during the entire packaging process more stable and is suitable for optical packaging of large-channel silicon photonic chips. Compared with directly using an N-channel fiber array 9, splicing two N / 2-channel fiber arrays solves the problem of insufficient fabrication process of the large-channel fiber array 9.

[0097] In some embodiments, only the asymmetric clamp 6 is used for optical encapsulation of the large-channel silicon photonic chip. This solves the instability problem caused by the stress on the pigtail due to the large mass of the large-channel fiber array 9, making the additional losses during the entire encapsulation process more stable. In other embodiments, while using the asymmetric clamp 6 to fix the fiber array 9, a pool-shaped block 82 is also installed on the PCB board 8. This not only applies to the optical encapsulation of large-channel silicon photonic chips, but also increases the automation level and stability of the entire optical encapsulation process, helping to shorten the encapsulation time.

[0098] It is worth mentioning that the embodiments of the present invention also provide an optical packaging method using the above-described optical packaging platform for silicon photonic chips.

[0099] like Figure 1The diagram illustrates the grating and waveguide structure on chip 81. Channels ch1-ch128 are the input / output ports for optical signals, which will be transmitted within the on-chip waveguides. Each channel has a grating port connected to a waveguide on either side of channel ch1 and ch128, serving as alignment gratings. Similar to traditional optical packaging processes, the fiber array 9 is first coupled to the alignment gratings on chip 81. Optical packaging requires coupling and encapsulating the fiber array 9, held by fixture 6, to the optical ports on both sides of chip 81, achieving end-to-end transmission of the optical signal.

[0100] The optical encapsulation method includes the following steps:

[0101] (1) On the three axes xyz of the package including chip 81, the position, magnification and focal length of the four optical magnifying lenses, namely the first optical magnifying lens 41, the second optical magnifying lens 42, the third optical magnifying lens 43 and the fourth optical magnifying lens 44, are manually adjusted to capture the field of view of the fiber array 9 in the three directions xyz.

[0102] (2) The electrically controlled displacement stage 5 adjusts the clamps 6 used to fix the fiber array 9 in six dimensions so that each fiber in the fiber array 9 is aligned with the grating on the surface of the chip 81.

[0103] Specifically, the end face of the fiber array 9 is lowered to approximately 1 mm above the edge of the chip 81 using the electrically controlled displacement stage 5. The rotation angle, coupling angle, and position in the xy direction of the fiber array 9 are roughly adjusted: First, the lower edge of the fiber array 9 is observed to be flush with the surface of the chip 81 using the second optical magnifying lens 42 or the third optical magnifying lens 43, and this is adjusted using the electrically controlled displacement stage 5. Next, the coupling angle of the fiber array 9 is observed using the fourth optical magnifying lens 44, ensuring that the lower end face of the entire fiber array 9 is flush with the surface of the chip 81; this process is also achieved by adjusting the electrically controlled displacement stage 5. Finally, the edge of the end face of the fiber array 9 is observed to be parallel to the center line of the fiber array 9 arrangement, or in other words, parallel to the edge of the chip 81, using the upper first optical magnifying lens 41; this process is also achieved by adjusting the electrically controlled displacement stage 5. After these three parallel adjustments are completed, the fiber array 9 is slowly lowered. Using the upper field of view obtained through the first optical magnifying lens 41, the outermost fiber output of the fiber array 9 is aligned with the outermost alignment grating of the chip 81 surface. Figure 1 As shown. This process requires repeatedly moving the fiber array 9 along the x and y axes, and constantly observing the optical power meter connected to the last fiber (i.e., detecting whether there is light at the output of the other end of the alignment loop). When light is detected at the other end, the position of the fiber array 9 in the x and y directions is finely adjusted near this position until the output optical power reaches the maximum value, indicating that the coupling state between the grating and the fiber array 9 is optimal at this time, and the coupling loss is minimal.

[0104] During this process, the position of the fiber array 9 in the xyz direction, the coupling angle, the parallelism between the end face of the fiber array 9 and the surface of the chip 81, and the parallelism between the end face edge of the fiber array 9 and the grating array were adjusted.

[0105] (3) Connect an optical power meter to the last fiber of the fiber array 9 to monitor the coupling loss of the fiber array 9.

[0106] It should be understood that the laser light travels from the first fiber of the fiber array 9, and the waveguide on the chip 81 transmits the laser light from the first fiber to the last fiber.

[0107] (4) When the optical power meter detects that the coupling loss of the fiber array 9 has reached the minimum value, the clamp 6 is adjusted to raise the fiber array 9 along the z-axis by the electric displacement stage 5.

[0108] It should be noted that the optical power meter monitors the coupling loss of the fiber array 9 in real time. When the coupling loss of the fiber array 9 cannot be reduced by moving it at various angles, the coupling loss monitored by the optical power meter at this time is the minimum coupling loss of the fiber array 9.

[0109] It should be understood that raising the fiber optic array 9 is for ease of subsequent operation, preventing it from touching other components and causing them to shift, thus affecting the optical packaging of the silicon photonics chip. The height of the fiber optic array 9 should be greater than or equal to 2cm to facilitate subsequent operations. It's easy to understand that the height of the fiber optic array 9 after raising it should be appropriate, facilitating both subsequent operations and allowing for quick repositioning to its original position during subsequent lowering.

[0110] (5) Apply curing adhesive evenly at the grating position on the surface of chip 81, and control the thickness of the curing adhesive to 0.5mm.

[0111] like Figure 5 and Figure 12 As shown, chip 81 protrudes a short distance from adapter board 83, making it extremely convenient to apply adhesive to the grating position at this location.

[0112] (6) Use the electric displacement stage 5 to adjust the clamp 6 to slowly move the fiber array 9 downward along the z-axis to reset it to its original position, so that the curing adhesive fills the gap between the fiber array 9 and the grating.

[0113] The curing adhesive used is UV adhesive, which fills the gap between the fiber array 9 and the grating. Due to the refractive index matching characteristics of the UV adhesive, the position of the fiber array 9 needs to be fine-tuned again to minimize the coupling loss. The coupling loss can be monitored by an optical power meter.

[0114] It should be understood that after the fiber array 9 is reset, it will gradually be immersed in the curing adhesive in the pool-shaped block 82 or in the curing adhesive at the grating position, thereby filling the gap between the fiber array 9 and the grating.

[0115] (7) Adjust the position of the fiber array 9 by adjusting the clamp 6 through the electric displacement stage 5 until the coupling loss value monitored by the optical power meter is the minimum.

[0116] (8) Use a UV lamp to cure the part of chip 81 that is in contact with fiber array 9 to ensure that the curing adhesive is completely solidified.

[0117] In this embodiment, the curing time varies depending on the thickness of the curing adhesive. For example, the curing adhesive on the pool-shaped block 82 is thicker, so it needs to be cured by irradiating the pool-shaped block 82 with a UV lamp for 1-51.5 hours to ensure that the curing adhesive is completely solidified. If the pool-shaped block 82 is not used and the curing adhesive is only on the grating on the surface of the chip 81, it is only necessary to irradiate the part of the chip 81 that is in contact with the fiber array 9 with a UV lamp for 15-30 minutes to ensure that the curing adhesive is completely solidified.

[0118] It should be understood that since the pool-shaped block 82 is made of acrylic material, ultraviolet light can penetrate it to achieve curing.

[0119] (9) After curing is completed, remove fixture 6 to complete the optical packaging of silicon photonic chip.

[0120] In this embodiment, a step (a) is added between step (5) and step (6): the pool-shaped block 82 is placed on the ceramic sheet 83 of the PCB board 8, a small amount of curing adhesive is added to the outside of the pool-shaped block 82 and the ceramic sheet 83 to fix the pool-shaped block 82, and the curing adhesive is filled into the pool-shaped block 82 by an automatic dispensing machine according to the preset amount of adhesive.

[0121] like Figure 5 As shown, the PCB board 8 has a window for determining the position of the pool-shaped block 82, which can be placed on the ceramic sheet 83 installed in the window of the PCB board 8.

[0122] It should be understood that with ceramic sheet 83 as the base and pool-shaped block 82 having a closed structure, the colloid cannot seep out.

[0123] Preferably, the curing adhesive is a UV adhesive. It should be understood that other adhesives with a fixing effect, such as quick-drying adhesives, may also be selected.

[0124] In this embodiment, a step (b) is added between step (7) and step (8): applying curing adhesive to the ceramic sheet 83, placing the support block 67 on the ceramic sheet 83 and pushing it between the clamping block 66 and the ceramic sheet 83 from one side of the clamping block 66, and curing the clamping block 66 and the support block 67 with curing adhesive.

[0125] Compared to the cumbersome traditional manual process of multiple dispensing and curing steps, this solution introduces automated dispensing control, requiring only a single dispensing and curing step. This avoids the high additional losses caused by uneven dispensing in traditional optical encapsulation processes, which leads to micro-shifts in the fiber array. Furthermore, this method is applicable to both small-channel and large-channel fiber arrays.

[0126] The encapsulation operation of this invention is simpler and the process is more efficient. Only one dispensing and curing process is required. Furthermore, the fiber array 9 is subjected to uniform force during the curing process, which reduces the high additional losses caused by uneven glue amount due to manual dispensing. In addition, the entire optical encapsulation process is more automated and more stable, which helps to shorten the encapsulation time and save time costs for optical encapsulation.

[0127] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not deviate from the scope of the technical solutions of the embodiments of the present invention in essence.

Claims

1. An optical packaging platform for a silicon photonic chip, characterized by, The optical packaging platform comprises: a substrate (1); a gantry (2) mounted on the substrate (1); a slide rail (3) mounted above the gantry (2); a viewing mirror set comprising a first optical zoom lens (41), a second optical zoom lens (42), a third optical zoom lens (43) and a fourth optical zoom lens (44), the first optical zoom lens (41) and the fourth optical zoom lens (44) being mounted on the slide rail (3), and the second optical zoom lens (42) and the third optical zoom lens (43) being oppositely arranged and mounted on the substrate (1); two electrically controlled displacement tables (5) mounted on the substrate (1); a clamp (6) for fixing an optical fiber array (9); a curved rod (7) for connecting the electrically controlled displacement tables (5) and the clamp (6), the curved rod (7) being provided with a first connecting portion (71); and a PCB board (8) mounted on the substrate (1) through a support, the PCB board (8) being provided with a chip (81), a ceramic sheet (83) and an adapter plate (84), the chip (81) being located below the adapter plate (84), and the PCB board (8) further being provided with a swimming pool-shaped block (82) which is solidified on the ceramic sheet (83) through solidified glue. The swimming pool-shaped block (82) has a closed structure, and is provided with a first blocking portion (821), two protrusions (822), two second blocking portions (823) and a third blocking portion (824), the two protrusions (822) being arranged at two ends of the first blocking portion (821), the two ends of the first blocking portion (821) being connected with one end of each of the two second blocking portions (823) respectively, and the two ends of the third blocking portion (824) being connected with the other end of each of the two second blocking portions (823) respectively. The protrusions (822) abut against the side edges of the chip (81), and the lower surfaces of the protrusions (822) abut against the upper surface of the adapter plate (84). The first blocking portion (821) abuts against the upper surface of the adapter plate (84). The inner sides of the second blocking portions (823) abut against the surface of the ceramic sheet (83). The third blocking portion (824) is located above the ceramic sheet (83), and the lower surface of the third blocking portion (824) abuts against the upper surface of the ceramic sheet (83).

2. The optical packaging platform for silicon photonic chips of claim 1, wherein, The optical zoom ratios of the first optical zoom lens (41), the second optical zoom lens (42), the third optical zoom lens (43) and the fourth optical zoom lens (44) are 0.7X-4.5X, and the zoom ratio is 6.5:

1.

3. The optical packaging platform for silicon photonic chips of claim 1, wherein, The clamp (6) comprises a main body portion (61) provided with a groove (62), the top end of the main body portion (61) being mounted on the first connecting portion (71), and the lower end of the main body portion (61) being fixedly provided with a fastening plate (63) provided with a plurality of positioning holes (64).

4. The optical packaging platform for silicon photonic chips of claim 1, wherein, The clamp (6) comprises a main body (61) and a clamping block (66), the main body (61) is provided with a groove (62), the lower end of the main body (61) is provided with a mounting seat (65), and the clamping block (66) is mounted on the mounting seat (65) through a stud.

5. The optical packaging platform for silicon photonic chips of claim 3 or 4, wherein, The first connecting part (71) is provided with a connecting seat (711), the connecting seat (711) is mounted at the top end of the groove (62), and the outer surface of the connecting seat (711) abuts with the inner surface of the groove (62); and / or, The clamp (6) further comprises a supporting block (67), which is located between the ceramic sheet (83) and the clamping block (66).

6. An optical packaging method based on the optical packaging platform for silicon photonic chips according to claim 5, characterized in that, The optical packaging method comprises the following steps: (1) In three axial directions xyz, the positions, magnification and focal length of the first optical zoom lens (41), the second optical zoom lens (42), the third optical zoom lens (43) and the fourth optical zoom lens (44) are manually adjusted, and the field of view of the optical fiber array (9) in the three directions xyz is captured; (2) The clamp (6) for fixing the optical fiber array (9) is adjusted in six dimensions by the electrically controlled displacement table (5), so that each optical fiber in the optical fiber array (9) is aligned with the grating on the surface of the chip (81); (3) An optical power meter is connected to the last optical fiber of the optical fiber array (9) for monitoring the coupling loss of the optical fiber array (9); (4) After the optical power meter monitors that the coupling loss of the optical fiber array (9) reaches a minimum value, the electrically controlled displacement table (5) is used to adjust the clamp (6) to raise the optical fiber array (9) along the z-axis direction; (5) Uniformly point the curing glue at the grating position on the surface of the chip (81), and control the thickness of the curing glue to be 0.5mm; place the swimming pool-shaped block (82) on the ceramic sheet (83) of the PCB (8), add a small amount of curing glue to the outside of the swimming pool-shaped block (82) and the ceramic sheet (83) to fix the swimming pool-shaped block (82), and fill the curing glue into the swimming pool-shaped block (82) according to the preset glue amount by the automatic dispensing machine; (6) The electrically controlled displacement table (5) is used to adjust the clamp (6) to slowly move the optical fiber array (9) back to the original position along the z-axis direction, so that the curing glue fills the gap between the optical fiber array (9) and the grating; (7) The position of the optical fiber array (9) is finely adjusted by the electrically controlled displacement table (5) to stop when the coupling loss value monitored by the optical power meter is the smallest; (8) The part of the chip (81) in contact with the optical fiber array (9) is cured by the ultraviolet lamp to ensure that the curing glue is completely solidified; (9) After the curing is completed, the clamp (6) is removed to complete the optical packaging of the silicon photon chip.

7. The optical packaging method for a silicon photonic chip according to claim 6, wherein, Between the step (7) and the step (8), there is also a step (b): smearing the curing glue on the ceramic sheet (83), placing the supporting block (67) on the ceramic sheet (83) and pushing it into the gap between the clamping block (66) and the ceramic sheet (83) from one side of the clamping block (66), and curing the clamping block (66) and the supporting block (67) with the curing glue.

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