Coupling packaging structure of two optical chips

Abstract

The invention relates to a coupling packaging structure of two optical chips. The coupling packaging structure of the optical chip comprises a first optical chip, a first optical fiber array coupled with the first optical chip and a first lens array arranged between the first optical chip and the first optical fiber array, the first lens array comprises an inclined lens array, and in the inclined lens array, the first optical fiber array is coupled with the first optical chip. The inclined lens comprises an inclined lens body and a first step groove formed in one side of the inclined lens body, and the first step groove is inwards contracted in a gradient shape from the two ends to the center in the axial direction of the inclined lens body, so that the inclined lens is in a thickness step shape in the axial direction of the inclined lens. According to the invention, the inclined lens arrays with different thicknesses are arranged at different channels, or the lens array with the lens center height changing is arranged, so that low-loss coupling is realized, and the coupling loss under the warping condition can be greatly reduced.

Description

Technical Field

[0001] The present invention relates to the field of optical communication technologies, and relates to a coupling and packaging structure for two optical chips, and particularly relates to a coupling and packaging structure for two multi-channel optical chips in the case of warping. Background Art

[0002] With the increase in the number of channels of an optical chip (PIC), for example, the number of channels increases from 4 to 8, then to 16, 32, 72, it will lead to a significant increase in the coupling difficulty between the PIC and the fiber array (FA). During the packaging process of the PIC, due to temperature changes and differences in the thermal expansion coefficients of multiple materials, warping inevitably occurs, as Figure 1 shown. In the case of the same PIC warping, the larger the number of channels, the greater the width along the side of the PIC end-face coupler, and the more sensitive it is to warping.

[0003] For example, for a 3D integrated optical engine, the warping of a single packaging module can only be controlled at about 50 μm. Since the heights of all channels of the FA are the same in the cross-section, this requires that the heights of the PIC and all channels of the FA be the same at the cross-section in order to achieve the alignment of all channels of the two, as Figure 1 (a) is a cross-sectional view of the multi-channel PIC end-face coupler, at this time the PIC can be normally coupled with the FA. Since the coupling between the PIC and the FA is extremely sensitive to position deviation, for example, for a silicon optical chip (SiPIC), the 1 dB position tolerance ≤ ±1 μm. Figure 1 (b) is a cross-sectional view of the end-face coupler when the multi-channel PIC is warped. At this time, the PIC cannot achieve low-loss coupling with the FA because not all channels are at the same height.

[0004] To address the above problems, there is currently a wavelength division multiplexing solution. By adopting this solution, different channels are coupled into a single waveguide in the PIC through a multiplexer, and then coupled to the FA. After the FA is coupled to the receiving end of the PIC, it is coupled to different waveguides through a demultiplexer, thereby significantly reducing the number of channels that need to be coupled. Therefore, the coupling loss between the PIC and the FA in the case of warping is significantly improved. However, integrating multiplexers and demultiplexers on the PIC is difficult and increases additional losses, and it is not conducive to interconnection scenarios that require a high number of optical fibers, such as switches or servers for AI. Another solution is to use a fan-out waveguide adapter board solution. The minimum spacing between adjacent optical fibers of a conventional FA is currently 127μm, which is limited by the diameter of the optical fiber, 125μm. The waveguide of the PIC can be reduced to 20μm. In this way, in the case of the same PIC warping, the smaller the total width of the multi-channel end-face coupler, the lower the coupling loss between the PIC and the FA. However, this solution is difficult to be compatible with the coupling of a large number of channels, and the multi-channel fan-out adapter board will also introduce additional insertion losses. In addition, to solve the above problems, there is also a grating coupler solution. By using a grating coupler, light is coupled out of the PIC almost vertically. In this way, even when the PIC is warped and different grating couplers in the PIC are not at the same height, it will hardly affect the coupling between the PIC and the FA. However, the grating coupler has a large insertion loss, and there are other problems such as polarization, high processing accuracy, and low spectral bandwidth.

[0005] Lens array coupling is a method widely used for the coupling and packaging of multi-channel PICs. However, the coupling position tolerance between the PIC and the lens close to the PIC is extremely low, so it is not applicable to the coupling of multi-channel PICs in the case of warping. Summary of the Invention

[0006] To solve at least some of the above problems in the prior art, the present invention provides two coupling and packaging structures for optical chips, specifically providing two coupling and packaging structures for multi-channel optical chips in the case of warping. The present invention realizes low-loss coupling by setting an inclined lens array with different thicknesses or a lens array with a changing lens center height at different channels, and can greatly reduce the coupling loss in the case of warping.

[0007] The present invention provides a coupling and packaging structure for an optical chip, including:

[0008] A first optical chip;

[0009] A first optical fiber array, which includes multiple optical fibers and is coupled to the first optical chip;

[0010] A first lens array, which is arranged between the first optical chip and the first optical fiber array, and the first lens array includes an inclined lens array,

[0011] In the tilted lens array, the light incident surface of the tilted lens is not perpendicular to the optical axis of the optical fiber, and the tilted lenses have different thicknesses at different channels.

[0012] Furthermore, the tilted lens includes a tilted lens body and a first stepped groove provided on one side of the tilted lens body. The first stepped groove is gradually inwardly tapered from both ends to the center along the axial direction of the tilted lens body, so that the tilted lens has a thickness step along its axial direction. The tilt angle and thickness step of the tilted lens body satisfy Equation (1), thereby obtaining a coupling and packaging structure based on tilted lenses with different thicknesses to correct the optical paths of each channel;

[0013] H = T·sin(β - α) / cosα 1)

[0014] Wherein, H is the magnitude of the optical axis offset, T is the thickness of the tilted lens body, θ is the tilt angle of the tilted lens body, n is the refractive index of the tilted lens body, β = 90 - θ is the angle of light incident on the tilted lens array, α is the refraction angle of light in the tilted lens array, and α = arcsin(sin(β) / n).

[0015] Furthermore, the tilt angle of the tilted lens body ≥ 45°C and the thickness ≥ 0.1 mm.

[0016] Furthermore, the coupling and packaging structure is a coupling and packaging structure based on tilted lenses with different thicknesses.

[0017] Furthermore, as the name implies, the tilted lens array is composed of multiple tilted lenses, which can correct the spot height deviation caused by factors such as the warping of the optical chip. By refracting the light to adjust the optical path, the optical signals of different channels can be transmitted at appropriate positions.

[0018] Furthermore, the coupling and packaging structure further includes:

[0019] A first substrate, which is arranged on one side of the first optical chip along the direction of optical signal transmission;

[0020] A second substrate, which is arranged at the bottom of the first optical fiber array.

[0021] Furthermore, the first optical fiber array includes an optical fiber array V-groove, optical fibers placed in the optical fiber array V-groove, and an optical fiber array cover plate for fixing the optical fibers.

[0022] Furthermore, the first optical chip includes a first optical chip substrate and a first optical chip cladding layer provided on the first optical chip substrate.

[0023] Furthermore, the first optical chip is a silicon optical chip, the first optical chip substrate is a silicon optical chip substrate, and the first optical chip cladding layer is silicon optical chip SiO2 layer. The silicon photonics chip SiO 2 layer functions as an insulator.

[0024] Further, the first lens array further includes at least one convex lens array. The convex lens array can focus light to achieve the mode field matching between the optical chip and the optical fiber, reducing the loss of optical signal transmission.

[0025] Further, the inclined lens array is an inclined convex lens array.

[0026] Further, in the inclined convex lens array, the inclined convex lens includes an inclined convex lens body, a first spherical convex surface provided on one side of the inclined convex lens body, and a second stepped groove provided on the other side of the inclined convex lens body. The second stepped groove is gradually inwardly converging from both ends to the center along the axial direction of the inclined convex lens body, so that the inclined convex lens has a thickness step along its axial direction, and the inclination angle and thickness step of the inclined convex lens body satisfy Equation 1).

[0027] Further, in the convex lens array, the convex lens unit includes a convex lens body and a second spherical convex surface provided on one side of the convex lens body; the convex lens array is provided at one end of the first optical fiber array to form an optical fiber array with a convex lens array, and / or the convex lens array is provided on the first substrate on the side close to the first optical fiber array; the inclined lens array or the inclined convex lens array is provided on the first substrate. The optical fiber array with a convex lens array cooperates with the convex lens array to achieve efficient coupling transmission of optical signals from the optical chip to the optical fiber.

[0028] Further, the convex lens array includes a first convex lens array and / or a second convex lens array.

[0029] Further, the lens unit of the first lens array can be made of materials such as silicon, glass, resin, etc.

[0030] Further, a coating layer is plated on the surface of the first lens array. That is, one or more optical thin films are plated on the lens surface. The coating layer is used to reduce the reflection of light on the lens surface and improve the light transmittance.

[0031] Further, the coating layer includes any one of an antireflection film, a filter film or a polarization film. Further preferably, the coating layer is an antireflection film.

[0032] The coupling and packaging structure based on tilted lenses with different thicknesses has tilted lenses with different thicknesses at different channels, which can correct the mode spots of the first optical chip output and input to the same height in the case of warping. Since the light spot is always divergent during spatial transmission, the tilted convex lens and / or convex lens array are used to focus and collimate the light, ensuring the mode spot matching with the fiber or the end-face coupler of the optical chip, thereby achieving low-loss coupling.

[0033] Furthermore, the coupling and packaging structure based on tilted lenses with different thicknesses can adopt the following two methods:

[0034] Method 1: The tilted lens, convex lens or tilted convex lens can first complete the electrical packaging of the first optical chip, measure the warping of the first optical chip, obtain the relative height distribution of the end-face couplers of different channels on the first optical chip, and then customize the mask plate of the lens array according to these height distributions, so as to obtain a lens array mask plate with different height distributions, and then carry out the design and processing of the tilted lens or convex lens. The advantages are low loss and low cost, and the disadvantages are long coupling and packaging process time and low efficiency.

[0035] Method 2: The maximum warping of the first optical chip is M, and M / N groups of lens arrays are made according to the warping amount N at a certain interval to obtain a tilted lens array, convex lens array or tilted convex lens array with different thickness change differences, where N is determined by the acceptable coupling loss. The advantages are short coupling and packaging process time and high efficiency, and the disadvantages are high loss and high cost.

[0036] Furthermore, the following method can be adopted to make the tilted lens array, convex lens array or tilted convex lens array:

[0037] In the tilted lens array, the method for forming the thickness step of the first stepped groove: The morphology of the thickness step can be processed at different positions by methods such as laser pre-processing + wet etching, 3D laser printing, nanoimprinting, and grayscale lithography; the method for forming the tilt of the tilted lens body: After cutting, grind a certain angle to achieve the tilt.

[0038] In the tilted convex lens array, the method for forming the first spherical convex surface: It can be realized by means of conventional lithography or nanoimprinting and other technologies; the method for forming the thickness step of the second stepped groove is similar to the method for forming the thickness step of the first stepped groove; the method for forming the tilt of the tilted convex lens body is similar to the method for forming the tilt of the tilted lens body.

[0039] In the convex lens array, the method for forming the second spherical convex surface is similar to the method for forming the first spherical convex surface.

[0040] The present invention provides a coupling and packaging structure for an optical chip, including:

[0041] Second optical chip;

[0042] Second optical fiber array, which is coupled to the second optical chip;

[0043] Second lens array, which is arranged between the second optical chip and the second optical fiber array. The second lens array includes a third convex lens array close to the second optical chip and a fourth convex lens array close to the second optical fiber array. In the third convex lens array, the central height of the third convex lens unit changes in the same way as the height of the end face coupler of the second optical chip, obtaining a coupling and packaging structure based on a lens array with different central heights.

[0044] The central height of each lens in the third convex lens array is specially designed according to the warping condition of the second optical chip. Lenses with different heights can specifically correct the optical signals emitted from different positions of the warped optical chip, change the optical path, and make the optical signals transmit in a suitable direction.

[0045] Further, the fourth convex lens array adopts a conventional height.

[0046] Further, the coupling and packaging structure is a coupling and packaging structure based on a lens array with different central heights.

[0047] Further, the second optical chip includes a second optical chip substrate and a second optical chip cladding layer arranged on the second optical chip substrate.

[0048] Further, the coupling and packaging structure further includes:

[0049] Third substrate, which is arranged on one side of the second optical chip;

[0050] Fourth substrate, which is arranged on one side of the second optical fiber array.

[0051] Further, the third substrate is arranged at the bottom of the second optical chip; the fourth substrate is arranged at the bottom of the second optical fiber array.

[0052] Further, the lens units in the second lens array can be realized by materials such as silicon, glass, and resin.

[0053] Further, the surface of the second lens array is coated with a coating layer.

[0054] Further, the coating layer includes any one of an antireflection film, a filter film, or a polarization film. More preferably, the coating layer is an antireflection film.

[0055] The coupling and packaging structure based on a lens array with different central heights sets the lens array near the second optical chip as a lens array with a varying central height of the lens (i.e., a lens array with different central heights), solves the problem of low-loss coupling between the second optical chip and the second optical fiber array under large warpage conditions, and proposes a manufacturing method for the lens array with a varying central height of the key device lens, achieving coupling with multiple channels, low loss, large tolerance, and high coupling efficiency.

[0056] Furthermore, the coupling and packaging structure based on a lens array with different central heights can adopt the following two methods:

[0057] Method 1: First, complete the electrical packaging of the second optical chip, measure the warpage of the second optical chip, obtain the relative height distribution of the end-face couplers of different channels on the second optical chip, and then customize the mask plate of the lens array according to these height distributions (compared with the mask plate of the conventional lens array, only the relative position of the window opening is changed), so as to obtain a lens array mask plate with different height distributions, and then complete the processing of the lens according to the conventional lens process. The advantages of this method are low loss and low cost, and the disadvantages are long coupling and packaging process time and low efficiency.

[0058] Method 2: Preset an acceptable maximum warpage Q, where Q is determined by the physical parameters of the two lens arrays and the preset coupling loss. Fabricate Q / P groups of lens arrays according to the warpage amount P at a certain interval to obtain lens arrays with different height change differences. Here, the selection of P should be less than or equal to the set lens position tolerance near the second optical chip (determined by the coupling loss between the lens array at this position and the second optical chip). In this way, Q / P groups of lens arrays can be pre-fabricated. Immediately afterwards, perform the electrical packaging of the second optical chip, measure the warpage of the second optical chip, obtain the relative height distribution of the end-face couplers of different channels on the second optical chip, and select the lens array closest to this relative height distribution. The advantages of this method are short coupling and packaging process time and high efficiency, and the disadvantages are high loss and high cost.

[0059] The principle of reducing the coupling loss under warpage in the coupling and packaging structure based on the tilted lens array in the present invention is as follows:

[0060] As Figure 2 shown, when light passes through the tilted lens from air (refractive index n = 1), its optical axis will undergo a position shift. The magnitude of the position shift is related to the tilt angle of the lens and the thickness of the lens. The magnitude of the optical axis shift is calculated as:

[0061] H = T·sin(β - α) / cosα 1)

[0062] Where T is the thickness of the lens, θ is the tilt angle of the lens, n is the refractive index of the lens, and it is assumed here that the light is incident from the air, β=90-θ is the angle at which the light is incident on the tilted lens, and α=arcsin(sin(β) / n) is the refraction angle of the light in the tilted lens.

[0063] Therefore, after multi-channel light beams at different heights pass through tilted lens arrays of different thicknesses or different inclination angles, they can be corrected to the same height by designing tilted lens arrays of appropriate thickness at different channels. In addition, since the light beam is always divergent when propagating in space, the convex lens array is used to focus the light into the optical fiber and PIC to achieve mode field matching between the two, thereby achieving high coupling efficiency.

[0064] The principle of reducing the coupling loss under warping conditions based on the coupling packaging structure of the lens array with different center heights in the present invention is as follows:

[0065] The present invention relates to 4 kinds of devices, such as Figure 3 The figure shows a cross-sectional view of four devices in the present invention. The coupling packaging structure includes a second optical chip, a third convex lens array (a lens array close to the second optical chip), a second optical fiber array, and a fourth convex lens array (a lens array close to the second optical fiber array). Figure 4 is the coupling efficiency position tolerance diagram between the third convex lens array and the second optical chip, Figure 5 This is a coupling efficiency position tolerance diagram of the third convex lens array and the fourth convex lens array. Compared with the 80% coupling efficiency position tolerance of the third convex lens array and the second optical chip, the 80% coupling efficiency position tolerance of the third convex lens array and the fourth convex lens array is significantly increased. Therefore, the third convex lens array is set to change with the warping of the second optical chip to maintain low-loss coupling between the two, and the high position tolerance of the third convex lens array and the fourth convex lens array is used to achieve low-loss coupling between the two in the case of misalignment.

[0066] The present invention has at least the following beneficial effects:

[0067] 1) The present invention provides a coupling packaging structure based on a tilted lens array, which solves the problem of coupling with an optical fiber array when the PIC is warped. The convex lens array is used to focus light into the optical fiber and the PIC. The tilted lens array with different channel thicknesses can correct the center of the light spot output or input of the end face coupler at different heights in the multi-channel PIC to the same height;

[0068] 2) Another coupling and packaging structure provided in the present invention is to set the height of the lens array near the center of the PIC to be the same as the height change of the PIC end-face coupler, and the lens array near the FA is selected as a conventional lens array with no height change. This ensures low-loss coupling in the case of high warping of the PIC, well solves the problem of low coupling position tolerance between the PIC and the lens array near the PIC, and through lens beam expansion, the mode spot between the two lens arrays is relatively large, and the relative position tolerance between the two is extremely large, thus being used to alleviate the problem that alignment cannot be achieved in the vertical direction due to warping;

[0069] 3) The present invention can be compatible with the coupling and packaging of optical chips - fiber arrays with multiple channels and large warping, with low coupling loss and large coupling tolerance;

[0070] 4) The manufacturing process of the core device of the present invention is simple, has large tolerance, and low cost. Description of the Drawings

[0071] To further clarify the above and other advantages and features of the embodiments of the present invention, a more specific description of the embodiments of the present invention will be presented with reference to the drawings. It can be understood that these drawings only depict typical embodiments of the present invention and thus will not be considered as limiting its scope. In the drawings, for clarity, the same or corresponding components will be denoted by the same or similar reference numerals.

[0072] Figure 1 A cross-sectional view of the PIC end-face coupler is shown ((a) is the cross-sectional view of the PIC end-face coupler when not warped, and (b) is the cross-sectional view of the PIC end-face coupler when warped);

[0073] Figure 2 A schematic diagram showing the optical path passing through the tilted lens is shown;

[0074] Figure 3 A cross-sectional view of four devices in the present invention is shown ((a) is the cross-sectional view of the second optical chip end-face coupler when warped, (b) is the cross-sectional view of the third convex lens array, (c) is the cross-sectional view of the fourth convex lens array, and (d) is the cross-sectional view of the second optical chip);

[0075] Figure 4 A coupling efficiency position tolerance diagram of the third convex lens array and the second optical chip is shown;

[0076] Figure 5 A coupling efficiency position tolerance diagram of the third convex lens array and the fourth convex lens array is shown;

[0077] Figure 6 A side view of the coupling and packaging structure of the first optical chip in Embodiment 1 is shown;

[0078] Figure 7Shows a top view of the coupling and packaging structure of the first optical chip in Embodiment 1;

[0079] Figure 8 Shows a 45° view of the coupling and packaging structure of the first optical chip in Embodiment 1;

[0080] Figure 9 Shows a top view of the inclined lens in the coupling and packaging structure of the first optical chip in Embodiment 1;

[0081] Figure 10 Shows a side view of the coupling and packaging structure of the first optical chip in Embodiment 2;

[0082] Figure 11 Shows a top view of the coupling and packaging structure of the first optical chip in Embodiment 2;

[0083] Figure 12 Shows a 45° view of the coupling and packaging structure of the first optical chip in Embodiment 2;

[0084] Figure 13 Shows a top view of the inclined lens in the coupling and packaging structure of the first optical chip in Embodiment 2;

[0085] Figure 14 Shows a side view of the coupling and packaging structure of the first optical chip in Embodiment 3;

[0086] Figure 15 Shows a top view of the coupling and packaging structure of the first optical chip in Embodiment 3;

[0087] Figure 16 Shows a 45° view of the coupling and packaging structure of the first optical chip in Embodiment 3;

[0088] Figure 17 Shows a top view of the inclined lens in the coupling and packaging structure of the first optical chip in Embodiment 3;

[0089] Figure 18 Shows a side view of the coupling and packaging structure of the first optical chip in Embodiment 4;

[0090] Figure 19 Shows a top view of the coupling and packaging structure of the first optical chip in Embodiment 4;

[0091] Figure 20 Shows a 45° view of the coupling and packaging structure of the first optical chip in Embodiment 4;

[0092] Figure 21 Shows a top view of the inclined lens in the coupling and packaging structure of the first optical chip in Embodiment 4;

[0093] Figure 22Shows a coupling side view with the second optical chip facing upward when there is no warping in Embodiment 5;

[0094] Figure 23 Shows a coupling side view with the second optical chip facing upward when warping occurs in Embodiment 6;

[0095] Figure 24 Shows a coupling side view with the second optical chip facing downward when warping occurs in Embodiment 7;

[0096] Reference numerals:

[0097] 1 - First optical fiber array, 101 - V-groove of optical fiber array, 102 - Cover plate of optical fiber array, 103 - Optical fiber, 2 - First convex lens array, 3 - Second convex lens array, 4 - Tilted lens array, 401 - Tilted lens body, 402 - First stepped groove, 5 - First optical chip, 501 - Cladding of first optical chip, 502 - Substrate of first optical chip, 6 - Second substrate, 7 - First substrate, 8 - Tilted convex lens array, 801 - Tilted convex lens body, 802 - Second stepped groove, 803 - First spherical convex surface, 9 - Light, 10 - Second optical chip, 1001 - Cladding of second optical chip, 1002 - Substrate of second optical chip, 11 - Second optical fiber array, 12 - Third convex lens array, 13 - Fourth convex lens array, 14 - Optical waveguide, 15 - Third substrate, 16 - Fourth substrate. Detailed implementation manners

[0098] It should be noted that the components in each drawing may be exaggerated for illustration purposes and are not necessarily drawn to scale correctly.

[0099] In the present invention, each embodiment is merely intended to illustrate the solution of the present invention and should not be construed as restrictive.

[0100] In the present invention, unless otherwise specified, the quantifiers "a" and "one" do not exclude the scenario of multiple elements.

[0101] It should also be noted here that in the embodiments of the present invention, for clarity and simplicity, only a part of the components or assemblies may be shown. However, those of ordinary skill in the art can understand that, under the teaching of the present invention, the required components or assemblies can be added according to the specific scenario needs.

[0102] It should also be noted here that within the scope of the present invention, the terms "same", "equal", "equivalent", etc. do not mean that the two values are absolutely equal, but allow a certain reasonable error. That is to say, these terms also cover "substantially the same", "substantially equal", "substantially equivalent".

[0103] It should also be noted here that in the description of the present invention, the orientation or positional relationship indicated by terms such as "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the present invention and simplifying the description, rather than explicitly or implicitly indicating that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as explicitly or implicitly indicating relative importance.

[0104] In addition, the embodiments of the present invention describe the process steps in a specific order. However, this is only for the convenience of distinguishing each step and does not limit the sequence of each step. In different embodiments of the present invention, the sequence of each step can be adjusted according to the adjustment of the process.

[0105] The following embodiments provide a variety of coupling and packaging structures for optical chips to solve the coupling problems caused by the warping of optical chips.

[0106] Embodiment 1 - Coupling and Packaging Structure Based on Inclined Lenses with Different Thicknesses Combined with Double Convex Lenses

[0107] Figures 6 - 8 The side view, top view, and 45° view of the coupling and packaging structure of the first optical chip 5 are respectively shown. Figure 9 The top view of the inclined lens in the coupling and packaging structure of the first optical chip 5 is shown. It can be seen that the coupling and packaging structure includes: a first optical chip 5, a first optical fiber array 1 coupled to the first optical chip 5, a first lens array disposed between the first optical chip 5 and the first optical fiber array 1, a first substrate 7 disposed on one side of the first optical chip 5 along the direction of optical signal transmission, and a second substrate 6 disposed at the bottom of the first optical fiber array 1; the first optical fiber array 1 includes a fiber array V-groove 101, an optical fiber 103 placed in the fiber array V-groove 101, and an optical fiber array cover plate 102 for fixing the optical fiber 103; the first optical chip 5 is a silicon optical chip, the first optical chip 5 includes a first optical chip substrate 502 and a first optical chip cladding 501 disposed on the first optical chip substrate 502, the first optical chip substrate 502 is a silicon optical chip substrate, and the first optical chip cladding 501 is silicon optical chip SiO 2A layer that plays an insulating role; the first lens array includes an inclined lens array 4 and two convex lens arrays; in the inclined lens array 4, the inclined lens includes an inclined lens body 401 and a first stepped groove 402 provided on one side of the inclined lens body 401. The first stepped groove 402 is gradually inwardly tapered from both ends to the center along the axial direction of the inclined lens body 401, so that the inclined lens has a thickness step along its axial direction. The inclination angle and thickness step of the inclined lens body 401 satisfy Equation 1), thereby obtaining a coupled packaging structure based on inclined lenses of different thicknesses to correct the optical paths of each channel; in the convex lens array, the convex lens unit includes a convex lens body and a second spherical convex surface provided on one side of the convex lens body; the inclined lens array 4 is provided on the first substrate 7. The two convex lens arrays respectively include a first convex lens array 2 and a second convex lens array 3. The first convex lens array 2 is provided at one end of the first optical fiber array 1 to form an optical fiber array with a convex lens array. The second convex lens array 3 is provided on the first substrate 7, on the side close to the first optical fiber array 1. The first convex lens array 2 and the second convex lens array 3 can focus light, realize the mode field matching between the optical chip and the optical fiber, reduce the loss of optical signal transmission, and realize the efficient coupled transmission of optical signals from the optical chip to the optical fiber. In addition, the lens units of the first lens array can be made of materials such as silicon, glass, and resin. An antireflection film is coated on the surface of the first lens array to reduce the reflection of light on the lens surface and improve the light transmittance.

[0108] The coupling and packaging process of the first optical chip 5 and the first optical fiber array 1 is as follows: complete the electrical packaging of the first optical chip 5 to make it have stable electrical connection performance, and then mount the packaged first optical chip 5 on a PCB (printed circuit board) or a substrate to provide stable electrical connection and physical support for the subsequent transmission and processing of optical signals; mount the inclined lens array 4 and complete the mounting of the first optical fiber array 1 with the first convex lens array 2; finally, complete the coupling of the second convex lens array 3 close to the first optical chip 5.

[0109] In this embodiment, a variety of key components (such as an inclined lens array, convex lens arrays at different positions, a first optical fiber array, etc.) are optimized and integrated. The first convex lens array 2 and the second convex lens array 3 together form a double convex lens structure. After the light is corrected by the inclined lens array 4 and then focused by the double convex lens, the mode field matching between the output light field of the first optical chip 5 and the mode field of the first optical fiber array 1 is realized. It can be compatible with the coupling and packaging of the first optical chip 5 and the first optical fiber array 1 with multiple channels and large warpage, thereby completing the efficient coupled transmission of optical signals from the first optical chip 5 to the first optical fiber array 1, while the traditional method is difficult to achieve such an efficient effect in mode field matching. Therefore, it has obvious advantages in supporting the transmission of high-channel optical signals and overcomes the disadvantages of difficult integration and poor compatibility of some existing solutions.

[0110] Embodiment 2 - Coupling and Packaging Structure Based on Inclined Lenses with Different Thicknesses Combined with a Single Convex Lens

[0111] Figures 9 - 12 Side view, top view, and 45° view of the coupling and packaging structure of the first optical chip 5 are respectively shown. Figure 13 The top view of the inclined lens in the coupling and packaging structure of the first optical chip 5 is shown. Compared with the coupling and packaging structure of Embodiment 1, the difference in this embodiment is only that: the first lens array includes an inclined lens array 4 and a single convex lens array, and this convex lens array is the first convex lens array 2 provided at one end of the first optical fiber array 1, and the rest are the same as those in Embodiment 1.

[0112] The coupling and packaging process of the first optical chip 5 and the first optical fiber array 1 is as follows: complete the electrical packaging of the first optical chip 5 to make it have stable electrical connection performance, and then mount the packaged first optical chip 5 on a PCB or a substrate to provide stable electrical connection and physical support for subsequent optical signal transmission and processing; mount the inclined lens array 4, and finally complete the coupling of the first optical fiber array 1 with the first convex lens array 2 mounted.

[0113] In this embodiment, after the light rays are corrected by the inclined lens array 4, the first convex lens array 2 focuses the corrected light rays to achieve the matching of the output optical field of the first optical chip 5 and the mode field of the first optical fiber array 1, thereby completing the efficient coupling and transmission of the optical signal from the first optical chip 5 to the first optical fiber array 1.

[0114] Embodiment 3 - Coupling and Packaging Structure Based on Inclined Convex Lenses with Different Thicknesses Combined with a Single Convex Lens

[0115] Figures 14 - 16 Side view, top view, and 45° view of the coupling and packaging structure of the first optical chip 5 are respectively shown. Figure 17 The top view of the inclined lens in the coupling and packaging structure of the first optical chip 5 is shown. Compared with the coupling and packaging structure of Embodiment 2, the difference in this embodiment is only that: the inclined lens array 4 is replaced by an inclined convex lens array 8, and the rest are the same as those in Embodiment 2.

[0116] The coupling and packaging process of the first optical chip 5 and the first optical fiber array 1 is as follows: complete the electrical packaging of the first optical chip 5 to make it have stable electrical connection performance, and then mount the packaged first optical chip 5 on a PCB or a substrate to provide stable electrical connection and physical support for subsequent optical signal transmission and processing; mount the inclined convex lens array 8, and finally complete the coupling of the first optical fiber array 1 with the first convex lens array 2 mounted.

[0117] In this embodiment, after the light passes through the inclined convex lens array 8 for correction, the first convex lens array 2 focuses the corrected light, realizing the matching of the output optical field of the first optical chip 5 and the mode field of the first optical fiber array 1, thereby completing the efficient coupling and transmission of the optical signal from the first optical chip 5 to the first optical fiber array 1.

[0118] Embodiment 4 - Coupling and Packaging Structure Based on Inclined Convex Lenses with Different Thicknesses

[0119] Figures 18 - 20 The side view, top view, and 45° view of the coupling and packaging structure of the first optical chip 5 are respectively shown. Figure 21 The top view of the inclined lens in the coupling and packaging structure of the first optical chip 5 is shown. Compared with the coupling and packaging structure of Embodiment 3, the difference in this embodiment is only that the first convex lens array 2 is removed, and the rest is the same as that of Embodiment 3.

[0120] The coupling and packaging process of the first optical chip 5 and the first optical fiber array 1 is as follows: complete the electrical packaging of the first optical chip 5 to make it have stable electrical connection performance, and then mount the packaged first optical chip 5 on a PCB or substrate to provide stable electrical connection and physical support for the subsequent transmission and processing of optical signals; complete the coupling of the inclined convex lens array 8 and complete the coupling of the first optical fiber array 1.

[0121] In this embodiment, after the light passes through the inclined convex lens array 8 for correction, the optical signal is emitted in a suitable state to create conditions for coupling, thereby completing the efficient coupling and transmission of the optical signal from the first optical chip 5 to the first optical fiber array 1.

[0122] In the coupling and packaging structures based on inclined (convex) lenses with different thicknesses in Embodiments 1 - 4, the inclination angle of the inclined lens body 401 ≥ 45 °C, and the thickness ≥ 0.1 mm.

[0123] Embodiment 5 - Coupling and Packaging Structure Based on Lens Arrays with Different Central Heights

[0124] Figure 22The coupled side view with the second optical chip 10 facing upward when there is no warping is shown. It can be seen that when there is no warping, the two lens arrays, the optical waveguide 14 of the second optical chip, and the optical fibers of the second fiber array 11 are at the same height. The coupled packaging structure includes: the second optical chip 10, the second fiber array 11 coupled to the second optical chip 10, the second lens array disposed between the second optical chip 10 and the second fiber array 11, the third substrate 15 disposed on one side of the second optical chip 10, and the fourth substrate 16 disposed on one side of the second fiber array 11; the second optical chip 10 includes the second optical chip substrate 1002 and the second optical chip cladding 1001 disposed on the second optical chip substrate 1002; the second lens array includes the third convex lens array 12 close to the second optical chip 10 and the fourth convex lens array 13 close to the second fiber array 11. In the third convex lens array 12, the center height of the third convex lens unit changes in the same way as the warping of the second optical chip with the change of the height of the end face coupler of the second optical chip, and a coupled packaging structure based on a lens array with different center heights is obtained. In addition, the lens units in the second lens array can be realized by materials such as silicon, glass, and resin, and an anti-reflection coating layer is plated on the surface of the second lens array.

[0125] In this embodiment, the coupling and packaging process of the second optical chip 10 and the second fiber array 11 is as follows: complete the electrical packaging of the second optical chip 10 and mount it on a PCB or a substrate; couple and package the lens array (the fourth convex lens array 13) close to the second fiber array 11 on the second fiber array 11. Couple the second fiber array 11 with the lens array to the second optical chip 10; finally, complete the coupling of the lens array close to the second optical chip 10.

[0126] Embodiment 6 - Coupled Packaging Structure Based on a Lens Array with Different Center Heights

[0127] Figure 23 The coupled side view with the second optical chip facing upward when there is warping is shown. It can be seen that when there is warping, the optical waveguide of the second optical chip and the optical fibers of the second fiber array 11 are not at the same height. The coupling and packaging process of this embodiment is the same as that of Embodiment 5.

[0128] Embodiment 7 - Coupled Packaging Structure Based on a Lens Array with Different Center Heights

[0129] Figure 24 The coupled side view with the second optical chip facing downward when there is warping is shown. It can be seen that the difference between the coupled packaging structure of this embodiment and that of Embodiment 6 is only that: the second optical chip 10 faces downward. The rest are the same as those in Embodiment 6.

[0130] In this embodiment, the coupling packaging process of the second optical core 10 and the second optical fiber array 11 is as follows: the fourth convex lens array 13 is coupled and packaged on the second optical fiber array 11; the second optical chip 10 is flipped so that it faces downward, and the coupling packaging of the lens array (third convex lens array 12) close to the second optical chip 10 is completed with the help of the second optical fiber array 11 with the lens array; the second optical chip is flipped upside down, and the coupling packaging of the second optical fiber array 11 is completed.

[0131] The coupling packaging structure based on tilted lenses of different thicknesses can be achieved by the following two methods:

[0132] Method 1: The tilted lens array 4, convex lens array or tilted convex lens array 8 can first complete the electrical packaging of the first optical chip 5, measure the warping of the first optical chip 5, and obtain the relative height distribution of the end face couplers of different channels on the first optical chip 5, and then customize the mask template of the lens array (tilted lens array 4, convex lens array or tilted convex lens array 8) according to these height distributions (compared with the mask template of the conventional lens array, only the relative position of the window is changed), so as to obtain the lens array mask template with different height distributions, and then design and process the tilted lens or convex lens.

[0133] Method 2: The maximum warping of the first optical chip 5 is M, and M / N groups of lens arrays are made according to the warping amount N at a certain interval to obtain a tilted lens array 4, a convex lens array or a tilted convex lens array 8 with different thickness variation differences, where N is determined by the acceptable coupling loss.

[0134] The inclined lens array 4, convex lens array or inclined convex lens array 8 in the above method 1 and method 2 can be manufactured by the following method:

[0135] In the tilted lens array 4, the thickness step forming method of the first step groove 402 can be realized by laser pre-processing + wet etching, 3D laser printing, nanoimprinting, grayscale lithography and other methods to realize the processing of the thickness step morphology at different positions; the tilt forming method of the tilted lens body 401 is realized by cutting and then grinding a certain angle to achieve tilt.

[0136] In the inclined convex lens array 8, the method for forming the first spherical convex surface 803 can be achieved with the help of conventional photolithography or nanoimprinting technology; the method for forming the thickness step of the second step groove 802 on the other side is similar to the method for forming the thickness step of the above-mentioned first step groove 402; the method for forming the inclination of the inclined convex lens body 801 is the same as the method for forming the inclination of the above-mentioned inclined lens body 401.

[0137] In the convex lens array, the method for forming the second spherical convex surface is the same as the method for forming the first spherical convex surface 803 described above.

[0138] The coupling and packaging structure based on a lens array with different central heights can adopt the following two methods:

[0139] Method 1: First, complete the electrical packaging of the second optical chip 10, measure the warp of the second optical chip 10, obtain the relative height distribution of the end-face couplers of different channels on the second optical chip 10, and then customize the mask plate of the second lens array according to these height distributions (compared with the mask plate of the conventional lens array, only the relative position of the window opening is changed), so as to obtain the mask plate of the second lens array with different height distributions. Then, complete the processing of the lens according to the conventional lens process. Specifically: use a centrifugal spin coater to evenly coat a layer of photoresist on a quartz or silicon substrate; apply lithography technology to transfer the mask plate pattern to the substrate to obtain a photoresist micro second lens array pattern; after the photoresist is exposed through the made mask plate and developed, a micro-relief structure formed by the photoresist material can be obtained. Determine the exposure amount, developer concentration, development time and other parameters required according to the depth of the target relief structure. First, obtain a micro-structure on the surface of the photoresist through exposure and development; put the quartz glass substrate with the made photoresist micro second lens array into an ion beam etching machine for ion beam etching, and take out the substrate from the vacuum chamber after etching is completed; remove the photoresist on the substrate to obtain a micro second lens array with fused quartz or silicon as the structural layer and the substrate; then thin and polish; coat an anti-reflection film; and finally cut.

[0140] Method 2: Preset an acceptable maximum warp Q, where Q is determined by the physical parameters of two second lens arrays and the preset coupling loss. Make Q / P groups of second lens arrays with a warp amount P at a certain interval to obtain second lens arrays with different height change differences. Here, the selection of P should be less than or equal to the lens position tolerance set near the second optical chip 10 (determined by the coupling loss between the second lens array and the second optical chip 10 at this place). In this way, Q / P groups of second lens arrays can be pre-processed and prepared. Immediately after that, complete the electrical packaging of the second optical chip 10, measure the warp of the second optical chip 10, obtain the relative height distribution of the end-face couplers of different channels on the second optical chip 10, and select the second lens array closest to this relative height distribution.

[0141] Although some embodiments of the present invention have been described in this application document, those skilled in the art can understand that these embodiments are only shown as examples. Those skilled in the art can think of numerous variant schemes, alternative schemes and improvement schemes without exceeding the scope of the present invention under the teaching of the present invention. The appended claims are intended to define the scope of the present invention and thereby cover the methods and structures within the scope of these claims themselves and their equivalent transformations.

Claims

1. A coupling packaging structure of an optical chip, characterized in that: include: First optical chip; A first optical fiber array, comprising a plurality of optical fibers and coupled to the first optical chip; A first lens array is disposed between the first optical chip and the first optical fiber array, wherein the first lens array comprises a tilted lens array, In the tilted lens array, the light incident surface of the tilted lens is not perpendicular to the optical axis of the optical fiber, and the tilted lens has different thicknesses at different channels.

2. The coupling packaging structure according to claim 1, characterized in that: The tilted lens comprises a tilted lens body and a first step groove provided on one side of the tilted lens body, wherein the first step groove is gradually inwardly contracted from both ends to the center along the axial direction of the tilted lens body, so that the tilted lens has a thickness step along the axial direction thereof; the tilt angle and the thickness step of the tilted lens body satisfy formula 1): H=T·sin(β-α) / cosα1) Wherein, H is the size of the optical axis offset, T is the thickness of the tilted lens body, θ is the tilt angle of the tilted lens body, n is the refractive index of the tilted lens body, β=90-θ is the angle at which the light is incident on the tilted lens array, α is the refraction angle of the light in the tilted lens array, and α =arcsin(sin(β) / n).

3. The coupling packaging structure according to claim 1, characterized in that: Also includes: A first substrate, which is arranged on one side of the first optical chip along the direction of optical signal transmission; The second substrate is arranged at the bottom of the first optical fiber array.

4. The coupling packaging structure according to claim 3, characterized in that: The first optical fiber array includes an optical fiber array V-groove, optical fibers placed in the optical fiber array V-groove, and an optical fiber array cover plate for fixing the optical fibers.

5. The coupling packaging structure according to claim 3, characterized in that: The first optical chip includes a first optical chip substrate and a first optical chip cladding layer disposed on the first optical chip substrate.

6. The coupling packaging structure according to claim 5, characterized in that: The first optical chip is a silicon photonic chip, the first optical chip substrate is a silicon photonic chip substrate, and the first optical chip cladding is a silicon photonic chip SiO2 layer.

7. The coupling packaging structure according to claim 6, characterized in that: The first lens array also includes at least one convex lens array.

8. The coupling packaging structure according to claim 7, characterized in that: The inclined lens array is an inclined convex lens array.

9. The coupling package structure according to claim 8, characterized in that: In the inclined convex lens array, the inclined convex lens includes an inclined convex lens body, a first spherical convex surface arranged on one side of the inclined convex lens body, and a second step groove arranged on the other side of the inclined convex lens body, and the second step groove is gradiently inward from both ends to the center along the axial direction of the inclined convex lens body, so that the inclined convex lens has a thickness step along its axial direction, and the inclination angle and thickness step of the inclined convex lens body satisfy formula 1).

10. The coupling packaging structure according to claim 9, characterized in that: In the convex lens array, the convex lens unit includes a convex lens body and a second spherical convex surface arranged on one side of the convex lens body; the convex lens array is arranged at one end of the first optical fiber array to form an optical fiber array with a convex lens array, and / or the convex lens array is arranged on the first substrate, close to one side of the first optical fiber array; the inclined lens array or the inclined convex lens array is arranged on the first substrate.

11. The coupling package structure according to claim 1, characterized in that: The surface of the first lens array is coated with a coating layer.

12. A coupling packaging structure of an optical chip, characterized in that: include: Second optical chip; a second optical fiber array coupled to the second optical chip; A second lens array is arranged between the second optical chip and the second optical fiber array. The second lens array includes a third convex lens array close to the second optical chip and a fourth convex lens array close to the second optical fiber array. In the third convex lens array, the center height of the third convex lens unit changes with the height of the second optical chip end face coupler.

13. The optical chip coupling packaging structure according to claim 12, characterized in that: The second optical chip includes a second optical chip substrate and a second optical chip cladding layer disposed on the second optical chip substrate.

14. The optical chip coupling packaging structure according to claim 12, characterized in that: Also includes: A third substrate, which is disposed on one side of the second optical chip; The fourth substrate is arranged on one side of the second optical fiber array.

15. The optical chip coupling packaging structure according to claim 12, characterized in that: The surface of the second lens array is coated with a coating layer.

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