An optical module and an optical chip packaging structure and a packaging method

Abstract

The application relates to a packaging structure and a packaging method of an optical module and an optical chip, wherein the packaging structure comprises a receiving end assembly, a stepped metal heat sink and a silicon-based optical interconnection assembly attached to the stepped metal heat sink; the silicon-based optical interconnection assembly comprises a laser, a silicon optical beam splitter, a lens group, a light-transmitting compensation gasket, a silicon optical modulator and a fiber array; the laser and the silicon optical beam splitter form a coplanar coupling; the silicon optical beam splitter and at least part of the collimating lenses in the lens group are fixed on the light-transmitting compensation gasket; the fiber array and the silicon optical modulator realize waveguide matching through an active coupling mode; the silicon optical modulator and the receiving end assembly are arranged at a distance of at least a preset interval, and the fiber array and / or the receiving end assembly are covered with a metal isolation cover. The application solves the yield bottleneck caused by high cost of multiple light sources, pollution of an open light path and low reliability of glue in the prior art, and finally forms a packaging scheme with compact structure, stable process and high productivity.

Description

Technical Field

[0001] The present invention relates to the technical field of module packaging, and in particular to a packaging structure and a packaging method for an optical module and an optical chip. Background Art

[0002] Amidst the rapid growth of the optical communications industry, optical modules, as core components, continue to evolve toward higher transmission rates, gradually increasing from 1.25G and 10G to 800G. This significant increase in speed requires not only higher performance from optical chips but also places stringent demands on integration, heat dissipation efficiency, and process reliability. In particular, achieving high-speed signal transmission, effective thermal management, and high-yield manufacturing within the limited packaging space of 800G OSFP DR8 silicon photonics solutions has become a technical challenge in the industry.

[0003] In the existing technology, in order to meet the needs of high-speed transmission, silicon photonic modules mostly use the Chip On Board packaging method, which is specifically done by directly mounting the silicon photonic chip on the PCB or the surface of a pre-fixed tungsten-copper heat sink, and using gold wire bonding to achieve electrical connection. Its optical system is usually provided by four 1311nm lasers to provide light sources, which are input into the silicon photonic chip after lens coupling and isolator, and finally the optical signal is output through an 8-channel optical fiber array. However, this solution significantly increases material costs due to the use of multiple discrete lasers, and the open optical path structure is easily affected by pollutants in the air, causing the performance of optical components to deteriorate. In addition, due to the limitations of the waveguide matching design between the silicon photonic chip and the optical fiber array, the low-refractive index glue used in the existing process has insufficient shear strength and is prone to interface failure under temperature cycling or mechanical stress, which directly restricts the long-term reliability and production yield of the module. Summary of the Invention

[0004] (1) Technical issues to be resolved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a packaging structure and packaging method for an optical module and an optical chip, which solves the technical problems of the existing silicon optical module packaging technology, such as high cost due to multiple lasers, open optical paths susceptible to contamination, and low reliability and yield caused by low shear glue.

[0006] (2) Technical solution

[0007] In order to achieve the above objectives, the main technical solutions adopted by the present invention include:

[0008] In a first aspect, an embodiment of the present invention provides a packaging structure for an optical module and an optical chip, comprising: an independently deployed receiving-end component, a stepped metal heat sink, and a silicon-based optical interconnect component mounted on the stepped metal heat sink;

[0009] Silicon-based optical interconnect components include lasers, silicon optical beam splitters, lens groups, transmittance compensation gaskets, silicon optical modulators, and optical fiber arrays;

[0010] A coplanar coupling in the direction perpendicular to the optical axis is formed between the light emitting end face of the laser and the incident end face of the silicon optical beam splitter;

[0011] The silicon optical beam splitter and at least part of the collimating lens in the lens group are fixed on the light-transmitting compensation spacer;

[0012] The optical fiber array and the silicon optical modulator achieve waveguide matching through active coupling, and the coupling interface between the optical fiber array and the silicon optical modulator is filled with a refractive index matching adhesive layer;

[0013] The silicon optical modulator and the receiving end component are separated and arranged at least at a preset distance, and the optical fiber array and / or the receiving end component are covered with a metal isolation cover capable of achieving continuous electromagnetic shielding.

[0014] Optionally, the incident end face and the output end face of the silicon optical beam splitter are coated with an anti-reflection film, and the splitting ratio of the silicon optical beam splitter is 1:1, which is used to split the single optical signal output by the laser into two outputs.

[0015] Optionally, the light-transmitting compensation spacer and the silicon optical beam splitter form a thermal expansion matching structure.

[0016] Optionally, the edge of the silicon optical beam splitter extends laterally beyond the boundary of the translucent compensation spacer to form a limiting structure covered by a barrier adhesive layer to prevent the solidified adhesive from overflowing onto the optical functional surface of the silicon optical beam splitter.

[0017] Optionally, the stepped metal heat sink comprises: a first stepped platform and a second stepped platform;

[0018] The first side of the first stepped platform is provided with a laser mounting position for fixing the laser via a silver adhesive patch, and the second side of the first stepped platform is bonded to the surface of the package substrate via a thermally-cured thermal adhesive layer;

[0019] The first side surface of the second stepped platform is provided with a light transmittance compensation gasket mounting position, a partial lens group mounting position and a silicon optical modulator mounting position, wherein the partial lens group mounting position is used to position at least one collimating lens aligned with the output end of the silicon optical beam splitter;

[0020] The second stepped platform has a height difference with respect to the first stepped platform, and the second side surface of the second stepped platform is integrated with the first stepped platform by mechanical connection or integral molding.

[0021] Optionally, a laser-specific heat dissipation portion is further provided on the first step platform, which is formed integrally from the same material as the stepped metal heat sink;

[0022] The laser-specific heat sink extends along the laser optical axis, and the contact area between the side surface of the laser-specific heat sink and the side surface of the laser at least covers the axial projection area corresponding to the laser heating core;

[0023] Among them, the axial projection area corresponding to the laser heating core is the area covering the multi-quantum well active layer in the laser semiconductor stack structure along the optical axis direction, and the lateral projection boundary of the laser heating core on the plane perpendicular to the optical axis coincides with the electrode installation position of the laser packaging shell.

[0024] In a second aspect, an embodiment of the present invention provides a packaging method for an optical module and an optical chip, for manufacturing the packaging structure of the optical module and the optical chip as described above, the method comprising:

[0025] After the stepped metal heat sink is fixed on the package substrate, the mounting mechanism is driven to mount the laser on the first step platform of the stepped metal heat sink;

[0026] Use a white light interferometer or a laser displacement sensor to measure the three-dimensional topography data of the laser upper surface and the preset installation area of ​​the silicon optical beam splitter;

[0027] Selecting a light-transmitting compensation spacer based on the three-dimensional topography data and controlling a vacuum nozzle to mount the selected spacer on the second step platform of the stepped metal heat sink, and mounting a silicon optical beam splitter and at least part of the collimating lens in the lens group on the light-transmitting compensation spacer;

[0028] Based on the spot distribution data fed back by the microscopic vision system, the nanometer translation stage is driven to adjust the relative position of the laser and the silicon optical beam splitter to achieve submicron coplanar coupling between the laser light output end face and the silicon optical beam splitter incident end face in the direction perpendicular to the optical axis.

[0029] Control the coordinated motion mechanism of the silicon light modulator and the fiber array. Under the condition of applying a modulation signal, dynamically optimize the waveguide matching position of the silicon light modulator and the fiber array based on the optical power data fed back by the photodetector, and inject refractive index matching glue at the coupling interface.

[0030] First, the optical path nodes are locally radiated and cured using an ultraviolet light source. Then, the oven is started to perform gradient temperature curing on the entire structure. During the curing process, the deformation of the adhesive layer is monitored in real time and displacement deviations are compensated.

[0031] Based on the electromagnetic field simulation data, the arrangement path of the receiving end components is generated with the silicon optical modulator as the center. The mounting mechanism is controlled to install two receiving end components according to the preset radius. The metal isolation cover covering the optical fiber array and / or the receiving end component is connected to the heat sink through laser welding to form a closed-loop shielding structure with continuous conductive connection.

[0032] Optionally, selecting a light-transmitting compensation spacer based on the three-dimensional topography data and controlling a vacuum nozzle to mount the selected spacer on the second stepped platform of the stepped metal heat sink, and mounting a silicon optical beam splitter and at least part of the collimating lens in the lens group on the light-transmitting compensation spacer includes:

[0033] Based on the three-dimensional topography data, the spatial height difference spectrum distribution is obtained through discrete Fourier transform;

[0034] Based on the peak and valley characteristics of the spatial height difference spectrum distribution, a light-transmitting compensation gasket with the most matching thickness step is selected from the pre-classified compensation gasket library. The gasket edge is designed with a slope transition structure to achieve continuous coverage of the adhesive layer.

[0035] The mounting mechanism is driven to mount the silicon optical beam splitter on the light-transmitting compensation pad, and the edge is controlled to extend beyond the boundary of the light-transmitting compensation pad to form a ring-shaped overflow groove structure, and the adhesive layer is cured by ultraviolet light exposure to form a limiting structure;

[0036] After placing at least part of the collimating lenses in the lens group at the output end of the silicon optical beam splitter on the transmittance compensation gasket, a wavefront aberration quantification model is established based on the feedback information of the back-projected light spot to analyze the astigmatism component introduced by the tilt of the lens group. The discrete tilt angle adjustment amount is output according to the wavefront aberration quantification model until the light spot symmetry reaches a preset threshold.

[0037] Optionally, the light transmittance compensation spacer needs to meet the following thickness conditions:

[0038] ;

[0039] Where argmin is the optimal thickness d selected from the pre-classified compensation gasket library to minimize the objective function opt , d k is the nominal thickness of the kth candidate gasket in the pre-classified gasket library, h t is the target height difference to be maintained, Ω is the effective area that needs to be compensated for the height, A is the area of ​​region Ω, and Δh(x,y) is the height difference between the top surface of the laser and the preset mounting area of ​​the silicon optical beam splitter.

[0040] Optionally, based on feedback information of the back-projected light spot, a wavefront aberration quantification model is established to analyze the astigmatism component introduced by the tilt of the lens group, and a discretized tilt angle adjustment amount is output according to the wavefront aberration quantification model until the light spot symmetry reaches a preset threshold, including:

[0041] A reverse calibration beam is projected onto a silicon optical beam splitter. After reflection from a lens group, the output spot image is captured by a CMOS sensor. The spot ellipticity and Strehl ratio are calculated to construct a joint evaluation function. The ellipticity represents the spot shape distortion, and the Strehl ratio represents the diffraction-limited performance of the optical system.

[0042] The Zernike polynomial decomposition is performed on the light spot image, a wavefront aberration quantification model is established, a coma coefficient related to the lens tilt is extracted, and an interference term irrelevant to the astigmatism is suppressed;

[0043] The initial tilt adjustment amount is calculated according to the coma coefficient, and the initial tilt adjustment amount is compensated and corrected in real time according to the temperature sensor data;

[0044] According to the corrected tilt adjustment amount, the nanometer displacement table is driven to adjust the lens tilt step by step at a preset step size, the ellipticity and Strehl ratio are recalculated after each adjustment, the joint evaluation function value is updated, and the iteration is terminated when the joint evaluation function value is less than or equal to 0.05, and the lens group position is locked; when the joint evaluation function value is greater than 0.05, the model is updated according to the latest astigmatism coefficient and the next adjustment cycle is entered;

[0045] wherein,

[0046] The joint evaluation function is:

[0047] ;

[0048] In the formula, J is the joint evaluation function value, ε is the light spot ellipticity, I min is the gray peak value in the short axis direction of the light spot, I max is the gray peak value in the long axis direction of the light spot, S is the Strehl ratio, is the total light intensity integral of the actual light spot, is the light intensity integral of the ideal diffraction limit;

[0049] The wavefront aberration quantification model is:

[0050] ;

[0051] In the formula, is the nth order mth Zernike polynomial basis, which is used to describe the wavefront phase distribution on the pupil plane, n is the polynomial radial order, n=1~6, m is the angular frequency term, m=-n~+n, a nm is the amplitude of the nth order mth aberration, ρ, is a normalized polar coordinate parameter;

[0052] The initial tilt adjustment amount is:

[0053] ;

[0054] In the formula, Δθx and Δθy are the initial tilt adjustment amounts of the x-axis and y-axis respectively, λ is the working wavelength of the laser, η is the equivalent optical magnification of the lens group at the working wavelength λ of the laser, is the coma coefficient caused by the X-axis tilt of the lens group The amplitude coefficient of the coma tail is along the negative X direction, is the coma coefficient caused by the Y-axis tilt of the lens group The amplitude coefficient of the coma aberration is along the positive Y direction;

[0055] The corrected tilt adjustment amount is:

[0056] ;

[0057] Where, is a placeholder representing Δθx or Δθy, γ is the thermal expansion compensation coefficient, , α j is the thermal expansion coefficient of the package substrate material, α t is the thermal expansion coefficient of the lens group material, T is the current ambient temperature, and T0 is the calibration temperature, which is 25°C.

[0058] (3) Beneficial effects

[0059] The beneficial effects of the present invention are:

[0060] First, the silicon-based optical interconnect assembly uses a coplanar coupling structure with vertical optical axes between the laser and the silicon optical beam splitter to eliminate optical path offset while reducing the number of lasers. It also uses a light-transmitting compensation gasket to fix the silicon optical beam splitter and the lens group as a whole, effectively reducing the risk of optical path contamination. In addition, the optical fiber array and the silicon optical modulator adopt an active coupling process, and a high shear strength refractive index matching adhesive layer is filled at the coupling interface, which not only achieves precise waveguide matching, but also enhances the interface reliability by improving the mechanical properties of the adhesive layer. At the same time, the silicon optical modulator and the receiving end component are separated and arranged at a preset spacing, and the optical fiber array and / or the receiving end component are covered with a continuous electromagnetic shielding metal isolation cover, which suppresses signal crosstalk, simplifies the packaging process, and improves high-speed receiving performance.

[0061] Therefore, the solution of the present invention significantly optimizes the packaging space and heat dissipation path through the collaborative design of independently deployed receiving-end components and stepped metal heat sinks, combined with the integrated layout of silicon-based optical interconnect components mounted on the heat sink. On the basis of reducing the number of lasers and lenses to reduce material costs, through strengthening the sealing of the optical path, optimizing the shear force and improving the electromagnetic compatibility, it systematically solves the yield bottlenecks caused by the high cost of multiple light sources, easy contamination of open optical paths and low-reliability glue in the existing technology, and finally forms a packaging solution with compact structure, stable process and high mass production. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 The overall packaging structure provided by the embodiment of the present invention;

[0063] Figure 2A first partial diagram of a packaging structure provided by an embodiment of the present invention;

[0064] Figure 3 A second partial diagram of the package structure provided by an embodiment of the present invention;

[0065] Figure 4 A schematic diagram of a packaging method according to an embodiment of the present invention;

[0066] Figure 5 Schematic diagram of the specific process of step S3 of the packaging method provided in an embodiment of the present invention;

[0067] Figure 6 The specific process of step S34 of the packaging method provided in an embodiment of the present invention is schematically illustrated.

[0068] [Description of Reference Numerals]

[0069] 1: Stepped metal heat sink; 2: Laser; 3: Laser-specific heat sink; 4: Silicon optical beam splitter; 5: Glass spacer; 6: Lens assembly; 7: Silicon optical modulator; 8: Package substrate; 9: Transmitter assembly; 10: Fiber optic array; 11: Receiver assembly. DETAILED DESCRIPTION

[0070] In order to better explain the present invention and facilitate understanding, the present invention is described in detail below through specific implementation methods in conjunction with the accompanying drawings.

[0071] like Figure 1 As shown, an embodiment of the present invention proposes a packaging structure of an optical module and an optical chip, comprising: an independently deployed receiving end component, a stepped metal heat sink 1, and a silicon-based optical interconnect component mounted on the stepped metal heat sink 1; the silicon-based optical interconnect component comprises a laser 2, a silicon optical beam splitter 4, a lens group 6, a transmittance compensation gasket, a silicon optical modulator 7, and an optical fiber array 10; a coplanar coupling in a direction perpendicular to the optical axis is formed between the light-emitting end face of the laser 2 and the incident end face of the silicon optical beam splitter 4; the silicon optical beam splitter 4 and at least part of the collimating lenses in the lens group 6 are fixed on the transmittance compensation gasket; the optical fiber array 10 and the silicon optical modulator 7 achieve waveguide matching through active coupling, and the coupling interface between the optical fiber array 10 and the silicon optical modulator 7 is filled with a refractive index matching adhesive layer; the silicon optical modulator 7 and the receiving end component are separated and arranged at least at a preset distance, and the optical fiber array 10 and / or the receiving end component are covered with a metal isolation cover capable of achieving continuous electromagnetic shielding.

[0072] First, the silicon-based optical interconnect assembly uses a coplanar coupling structure with a vertical optical axis between the laser 2 and the silicon optical beam splitter 4 to eliminate optical path offset while reducing the number of lasers 2. The silicon optical beam splitter 4 and the lens group 6 are fixed integrally using a light-transmitting compensation gasket, effectively reducing the risk of optical path contamination. In addition, the optical fiber array 10 and the silicon optical modulator 7 use an active coupling process, and a high shear strength refractive index matching adhesive layer is filled at the coupling interface, which not only achieves precise waveguide matching, but also enhances interface reliability by improving the mechanical properties of the adhesive layer. At the same time, the silicon optical modulator 7 and the receiving end component are separated and arranged at a preset spacing, and the optical fiber array 10 and / or the receiving end component are covered with a continuous electromagnetic shielding metal isolation cover, thereby suppressing signal crosstalk, simplifying the packaging process, and improving high-speed receiving performance.

[0073] Therefore, the solution of the present invention significantly optimizes the packaging space and heat dissipation path through the collaborative design of the independently deployed receiving end component and the stepped metal heat sink 1, combined with the integrated layout of the silicon-based optical interconnection component mounted on the heat sink. On the basis of reducing the number of lasers 2 and lenses to reduce material costs, through the strengthening of optical path sealing, shear force optimization and electromagnetic compatibility improvement, it systematically solves the yield bottlenecks caused by the high cost of multiple light sources, easy contamination of open optical paths and low-reliability glue in the existing technology, and finally forms a packaging solution with compact structure, stable process and high mass production.

[0074] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments described herein. Rather, these embodiments are provided to enable a clearer and more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0075] Specifically, the overall working principle of the silicon-based optical interconnect component provided by the embodiment of the present invention is: the silicon optical beam splitter 4 divides the single optical signal output by the laser 2 into two outputs, and then transmits the signal to the silicon optical modulator 7 through the lens group 6 for signal modulation. The modulated signal is then transmitted by the optical fiber array 10 to two independently deployed receiving end components.

[0076] The laser 2 is a single 1310 nm high-power light source, which is used to replace multiple discrete lasers in the prior art.

[0077] Secondly, the lens group 6 includes a collimating lens and a coupling lens, which has the following functions: achieving light beam collimation (eliminating the divergence angle), adjusting the spot size to match the waveguide aperture, compensating for the mode mismatch between the silicon optical device and the optical fiber array 10, collimating and coupling the split light, and matching the waveguide aperture of the silicon optical modulator 7.

[0078] Next, the incident and output end faces of silicon optical beam splitter 4 are coated with antireflection coatings, and silicon optical beam splitter 4 has a 1:1 splitting ratio, used to split the single optical signal output by laser 2 into two equal output paths. The present invention uses silicon optical beam splitter 4 to split a high-power light source into two paths, which are then coupled to lens assembly 6 and then enter silicon optical modulator 7. This saves high-power light sources and space, reduces cost and power, improves reliability, and simplifies the drive circuit of laser 2.

[0079] At the same time, by matching the expansion coefficients of the translucent compensating gasket and the silicon-based material, a thermal expansion matching structure is formed between the translucent compensating gasket and the silicon optical beam splitter 4. Specifically, the translucent compensating gasket is made of UV-transparent glass, and its thermal expansion coefficient is matched with that of the silicon optical beam splitter 4. This allows the coupled optical path between the silicon optical beam splitter 4 and the laser 2 to achieve displacement compensation through material cooperative deformation under temperature fluctuation conditions, thereby stably controlling the optical axis alignment accuracy to the submicron level, thereby avoiding the waveguide offset problem caused by thermal stress in traditional open optical paths. This thermal expansion matching structure is particularly suitable for high-density optical interconnect scenarios and provides key reliability assurance for the packaging of silicon optical modules with speeds above 800G.

[0080] Furthermore, the edge of the silicon optical beam splitter 4 extends laterally beyond the boundary of the translucent compensating spacer by at least 0.05 mm, forming a stopper structure covered by a barrier adhesive layer to prevent the solidified colloid from overflowing onto the optically functional surfaces of the silicon optical beam splitter 4. The geometric characteristics of this stopper structure ensure that during the adhesive coating process between the translucent compensating spacer and the stepped metal heat sink 1, any overflowing colloid is first confined within the physical barrier formed by the outer edge of the silicon optical beam splitter 4. This design effectively blocks the path of lateral diffusion of the colloid material to the optically functional surfaces of the silicon optical beam splitter 4, such as the grating coupling region and waveguide array.

[0081] refer to Figure 1 and Figure 2 The stepped metal heat sink 1 comprises a first stepped platform and a second stepped platform. The second stepped platform has a height difference relative to the first stepped platform, and the second side surface of the second stepped platform is integrated with the first stepped platform through mechanical fastening or integral molding. The stepped metal heat sink 1 is entirely constructed of tungsten-copper material with high thermal conductivity and low thermal expansion coefficient.

[0082] The first side of the first stepped platform features a mounting position for laser 2, which is secured via a silver adhesive patch. The second side of the first stepped platform is bonded to the surface of the package substrate 8 via a thermally cured thermal adhesive layer. This bonding of the first stepped platform to the package substrate 8 significantly improves the efficiency of heat transfer from laser 2 to the substrate. Furthermore, the material's coefficient of thermal expansion is close to that of silicon-based components, reducing interfacial stress caused by temperature fluctuations and directly addressing the reliability issue of optical path deviation caused by thermal stress.

[0083] The first side surface of the second stepped platform is provided with a translucent compensation gasket mounting position, a partial lens group 6 mounting position and a silicon light modulator 7 mounting position. The translucent compensation gasket mounting position is used to fix the translucent compensation gasket; the partial lens group 6 mounting position is used to position at least one collimating lens aligned with the output end of the silicon light beam splitting chip, and the rest of the lens group 6 can be set on the translucent compensation gasket.

[0084] The second-step platform is designed with a preset height difference and horizontally spaced mounting positions, so that the transmittance compensation gasket can absorb the height tolerance between the laser 2 and the silicon optical beam splitter chip. At the same time, the spatial separation layout of the mounting positions of some lens groups 6 and the mounting positions of the silicon optical modulator 7 avoids cross-interference of the optical path and solves the core pain point of difficult optical path alignment.

[0085] Refer again Figure 1 It can be seen that a laser-specific heat dissipation portion 3 is also provided on the first step platform, which is integrally formed of the same tungsten-copper material with high thermal conductivity and low expansion coefficient as the stepped metal heat sink 1, and extends along the optical axis direction of the laser 2 and forms a local convex structure; the laser-specific heat dissipation portion 3 extends along the optical axis direction of the laser 2, and the contact area between the side surface of the laser-specific heat dissipation portion 3 and the side surface of the laser 2 at least covers the axial projection area corresponding to the heating core of the laser 2.

[0086] The heat-generating core of laser 2 is defined as the active region within laser 2 that generates a 1310nm wavelength optical signal. This region, during operation, forms the primary heat source due to loss in electro-optical conversion efficiency. The axially projected area corresponding to the heat-generating core of laser 2 covers the region along the optical axis that includes the multi-quantum well active layer within the semiconductor stack structure of laser 2. The lateral projection boundary of the heat-generating core of laser 2, projected perpendicular to the optical axis, coincides with the electrode mounting location of the laser 2 package.

[0087] It should be clarified that the multi-quantum well active layer is the core area of ​​the semiconductor laser 2 that generates photons through carrier recombination. When it is working, it generates significant heat due to insufficient electro-optical conversion efficiency (usually about 30-50%) and is the main heat source.

[0088] The lateral projection boundary coincides with the electrode location: The lateral projection boundary refers to the outline of the heat source region on a plane perpendicular to the optical axis. Electrodes are typically located on the sides or top of the laser package and are used to inject current to drive the active layer. If the lateral projection boundary of the heat source coincides with the electrode mounting location, it indicates that the electrode layout is horizontally aligned with the heat source region.

[0089] like Figure 3As shown, in the packaging structure of the present invention, the two 400G receiving components 11 and the 800G silicon photonic transmitting component 9 are separated and arranged with a preset spacing of at least 5 mm, and the receiving end component and the transmitting component 9 form an asymmetric layout through the physical isolation area of ​​the stepped metal heat sink 1; at the separation interface between the receiving end component and the transmitting component 9, it is covered with a continuous metal isolation cover, which is made of high-conductivity aluminum-magnesium alloy, and a fully closed electromagnetic shielding cavity is formed between the side wall of the metal isolation cover and the stepped metal heat sink 1 through a conductive adhesive layer.

[0090] On the other hand, an embodiment of the present invention further provides a packaging method for an optical module and an optical chip, which is used to manufacture the packaging structure of the optical module and the optical chip as described above. Figure 4 As shown, the method includes:

[0091] S1. After securing the stepped metal heat sink 1 to the package substrate 8, the mounting mechanism is driven to mount the laser 2 on the first step of the stepped metal heat sink 1. The stepped metal heat sink 1 is secured to the surface of the package substrate 8 via a heat-cured adhesive layer. The stepped metal heat sink 1 is made of a tungsten-copper material with high thermal conductivity and a low coefficient of expansion. A silver adhesive bonding process is used to secure the 1310nm high-power laser 2 to the first step of the stepped metal heat sink 1. The silver adhesive layer is heat-cured to form a thermally conductive interface.

[0092] S2. Use a white light interferometer or a laser displacement sensor to measure the three-dimensional topography data of the upper surface of the laser 2 and the preset installation area of ​​the silicon optical beam splitter 4.

[0093] S3. Select a translucent compensation gasket based on the three-dimensional morphology data and control the vacuum nozzle to mount the selected gasket to the second step platform of the stepped metal heat sink 1, and mount the silicon optical beam splitter 4 and at least part of the collimating lens in the lens group 6 on the translucent compensation gasket.

[0094] Furthermore, if Figure 5 As shown, step S3 includes:

[0095] S31. Based on the three-dimensional morphology data, the spatial height difference spectrum distribution is obtained through discrete Fourier transform.

[0096] S32. Based on the peak and valley characteristics of the spatial height difference spectrum distribution, select a translucent compensating gasket with the most matching thickness step from the pre-classified compensating gasket library, and design the gasket edge with a slope transition structure to achieve continuous adhesive coverage. The translucent compensating gasket must meet the following thickness requirements:

[0097] ;

[0098] Where argmin is the optimal thickness d selected from the pre-classified compensation gasket library to minimize the objective functionopt , d k is the nominal thickness of the kth candidate gasket in the pre-classified gasket library, and the candidate thickness d k Pre-processed into standardized gaskets with fixed step length (such as 10μm), no customized production is required, making the packaging process compatible with industrial-grade mass production requirements, 10μm ≤d k ≤ 200μm, h t is the target height difference to be maintained, which is the height difference calculated by optical simulation, Ω is the effective area that needs to be compensated for the height, A is the area of ​​region Ω, Δh(x, y) is the height difference between the upper surface of the laser 2 and the preset mounting area of ​​the silicon optical beam splitter 4, and x, y are the coordinates of a point in a two-dimensional coordinate system, covering the compensation area.

[0099] S33, drive the mounting mechanism to mount the silicon optical beam splitter 4 on the translucent compensation gasket, and control the edge to extend beyond the boundary of the translucent compensation gasket to form a ring-shaped overflow groove structure, and expose the glue layer through ultraviolet light to form a limiting structure.

[0100] S34. After placing at least part of the collimating lenses in the lens group 6 at the output end of the silicon optical beam splitter 4 on the transmittance compensation gasket, a wavefront aberration quantification model is established based on the feedback information of the reversely projected light spot, and the astigmatism component introduced by the tilt of the lens group 6 is analyzed. The discrete tilt angle adjustment amount is output according to the wavefront aberration quantification model until the symmetry of the light spot reaches a preset threshold.

[0101] Furthermore, if Figure 6 As shown, step S34 includes:

[0102] S341. Project a reverse calibration beam toward the silicon optical beam splitter 4. After reflection from the lens group 6, the output spot image is captured by the CMOS sensor. The spot ellipticity and Strehl ratio are calculated to construct a joint evaluation function. The ellipticity represents the spot shape distortion, and the Strehl ratio represents the diffraction-limited performance of the optical system. The joint evaluation function is:

[0103] ;

[0104] Where J is the joint evaluation function value, ε is the spot ellipticity, I min is the grayscale peak value in the short axis direction of the light spot, I max is the grayscale peak value in the long axis direction of the light spot, S is the Strehl ratio, is the total light intensity integral of the actual light spot, is the light intensity integral of the spot under the ideal diffraction limit, where x and y are the position coordinates of each pixel in the spot image.

[0105] S342, perform Zernike polynomial decomposition on the spot image, establish a wavefront aberration quantification model, extract the coma coefficient related to lens tilt, and suppress interference terms unrelated to astigmatism. The wavefront aberration quantification model is:

[0106] ;

[0107] Where Φ(x, y) represents the phase deviation at each position (x, y) on the pupil plane, reflecting the wavefront distortion caused by optical aberrations. is the nth order mth term Zernike polynomial basis, orthogonally normalized within the unit circle, used to describe the wavefront phase distribution on the pupil plane. Each Zernike polynomial corresponds to a basic aberration mode (such as defocus, astigmatism, coma, etc.). By superimposing these modes, arbitrary wavefront distortion can be fully expressed. n is the radial order of the polynomial, n=1~6, m is the angular frequency term, m=-n~+n, a nm is the magnitude of the nth-order mth aberration, ρ, is the normalized polar coordinate parameter, 0≤ρ≤1, 0≤ <2π.

[0108] S343, calculate the initial tilt angle adjustment amount based on the coma coefficient, and perform thermal expansion compensation correction on the initial tilt angle adjustment amount in combination with the real-time data of the temperature sensor. The initial tilt angle adjustment amount is:

[0109] ;

[0110] Where Δθx and Δθy are the initial tilt adjustment values ​​of the x-axis and y-axis respectively, λ is the laser operating wavelength, and η is the equivalent optical magnification of the lens group 6 under λ. is the coma coefficient caused by the X-axis tilt of lens group 6 The amplitude coefficient, in units of optical path length, quantifies the coma amplitude caused by lens tilt. The coma tail is in the negative X direction. is the coma coefficient caused by the Y-axis tilt of lens group 6 The amplitude coefficient of the coma aberration is along the positive Y direction.

[0111] Specifically, the interference items caused by the above aberration patterns include:

[0112]

[0113] S344. According to the corrected tilt adjustment amount, drive the nano-displacement stage to gradually adjust the lens tilt angle with a preset step size. Recalculate the ellipticity and Strehl ratio after each adjustment step, and update the joint evaluation function value. When the joint evaluation function value is ≤0.05, terminate the iteration and lock the position of lens group 6; when the joint evaluation function value is >0.05, update the model according to the latest astigmatism coefficient and enter the next adjustment cycle.

[0114] Among them, the corrected tilt angle adjustment amount is:

[0115] ;

[0116] Where, is a placeholder used for any single axial tilt adjustment, such as Δθx or Δθy, γ is the thermal expansion compensation coefficient, , α j is the thermal expansion coefficient of the packaging substrate 8 material, α t is the thermal expansion coefficient of the lens material, , T is the current temperature, T0 is the calibration temperature, and the value is 25℃.

[0117] S4. Based on the spot distribution data fed back by the microscopic vision system, drive the nano-displacement stage to adjust the relative position of the laser 2 and the silicon optical beam splitter 4 to achieve submicron coplanar coupling between the light-emitting end face of the laser 2 and the incident end face of the silicon optical beam splitter 4 in the direction perpendicular to the optical axis.

[0118] S5. Control the coordinated motion mechanism of the silicon light modulator 7 and the optical fiber array 10. Under the condition of applying a modulation signal, dynamically optimize the waveguide matching position of the silicon light modulator 7 and the optical fiber array 10 according to the optical power data fed back by the photodetector, and inject a refractive index matching glue at the coupling interface.

[0119] Specifically, the silicon optical modulator 7 and the 8-channel optical fiber array 10 are mounted on the stepped metal heat sink 1; the optical fiber array 10 and the waveguide of the silicon optical modulator 7 are matched to the optimal position through active coupling, and the coupling interface is filled with low-refractive-index glue, whose value range is 1.30~1.45.

[0120] S6. First, perform local radiation curing on the optical path nodes through the ultraviolet light source, and then start the oven to perform gradient temperature curing on the entire structure. During the curing process, the deformation of the adhesive layer is monitored in real time and the displacement deviation is compensated.

[0121] UV pre-curing is performed on the mounted laser 2, silicon optical splitter 4, at least part of the collimating lenses in the lens group 6, light-transmissive compensation pad, silicon optical modulator 7 and fiber array 10 to fix the optical path position, and the silicon-based optical interconnection assembly after UV pre-curing is placed in an oven for heat curing, so that the UV adhesive layer reaches a preset bonding strength at a controlled temperature, while avoiding optical path deviation caused by thermal stress. Specifically, the heat curing temperature curve can be set as follows: heating to 120℃ at a rate of 3℃ / min and keeping for 30min, and then cooling to room temperature at a rate of 2℃ / min, so as to eliminate thermal stress and ensure bonding strength.

[0122] It should be emphasized that the thermal expansion coefficient of the light-transmissive compensation pad matches the silicon-based material of the silicon optical splitter 4, forming a thermal expansion matching structure, and the UV adhesive layer is uniformly penetrated and cured in the optical axis direction through the light-transmissive property of the light-transmissive compensation pad during UV pre-curing.

[0123] S7. According to the electromagnetic field simulation data, the arrangement path of the receiving end assembly is generated with the silicon optical modulator 7 as the center, the mounting mechanism is controlled to install two receiving end assemblies with a preset radius, and the metal isolation cover covering the fiber array 10 and / or the receiving end assembly is connected to the heat sink to form a continuous conductive connection closed loop shielding structure. Specifically, the two receiving end assemblies are arranged within a radius of at least 5mm with the silicon optical modulator 7 as the center; the metal isolation cover covers the silicon optical modulator 7 and the receiving end assembly, and the metal isolation cover and the stepped metal heat sink 1 form a continuous electromagnetic shielding cavity through the conductive adhesive layer.

[0124] In summary, the embodiment of the present application provides a packaging structure and packaging method of an optical module and an optical chip, and the overall implementation process is as follows:

[0125] First, the high-power 1310nm laser 2 is directly coupled with the silicon optical splitter 4 with antireflection film coated on both ends, the 1:2 splitting characteristic of the silicon optical splitter 4 is used to divide the single light source into two light signals, and the traditional double-laser scheme is replaced equivalently while ensuring the uniformity of optical power, thereby significantly reducing the cost of the light source assembly.

[0126] Further, the UV light-transmissive glass pad 5 is arranged below the silicon optical splitter 4 and part of the collimating lenses, the thermal expansion coefficient of the pad matches the silicon-based material, which can realize uniform penetration of the adhesive layer through UV curing to enhance the bonding strength, and can also avoid the problem of optical path deviation caused by temperature change through thermal expansion compensation.

[0127] At the same time, by separating the two receiving end components and the transmitting component 9 centered on the silicon optical modulator 7 at a preset distance, and combining them with a metal shield to continuously electromagnetically isolate the two, the electromagnetic interference of the high-speed modulation signal at the transmitting end on the receiving end optical detector is effectively suppressed, so that the bit error rate and channel crosstalk performance of the receiving end are significantly optimized.

[0128] Ultimately, this solution uses optical path sealing and a phased curing process. By streamlining the number of lasers 2 (reduced by 1) and the size of lens groups 6 (reduced by 2), it reduces material costs while simplifying the packaging structure. Its modular design takes into account both process reliability and mass production consistency, making it suitable for large-scale production of 800G and above high-speed optical modules.

[0129] Since the systems / devices described in the above embodiments of the present invention are systems / devices used to implement the methods of the above embodiments of the present invention, those skilled in the art will be able to understand the specific structures and variations of these systems / devices based on the methods described in the above embodiments of the present invention, and thus will not be described in detail here. All systems / devices used in the methods of the above embodiments of the present invention are within the scope of protection of the present invention.

[0130] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROMs, optical storage, etc.) containing computer-usable program code.

[0131] The present invention is described with reference to flowcharts and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It should be understood that each process and / or block in the flowcharts and / or block diagrams, as well as combinations of processes and / or blocks in the flowcharts and / or block diagrams, can be implemented by computer program instructions.

[0132] It should be noted that in the scheme of the present invention, any figure marks between brackets should not be understood as limiting the scheme of the present invention. The word "comprising" does not exclude the presence of components or steps not listed in the scheme of the present invention. The word "a" or "an" preceding a component does not exclude the presence of multiple such components. The present invention can be implemented with the help of hardware comprising several different components and with the help of appropriately programmed computers. In the scheme of the present invention that lists several devices, several of these devices can be embodied by the same hardware. The use of the words first, second, third, etc. is only for convenience of expression and does not indicate any order. These words can be understood as part of the name of the component.

[0133] In addition, it should be noted that, in the description of this specification, the description of the terms "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0134] Although the preferred embodiments of the present invention have been described, those skilled in the art may make other changes and modifications to these embodiments after learning the basic creative concept. Therefore, the present invention should be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0135] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the present invention and its equivalents, the present invention should also include these modifications and variations.

Claims

1. A packaging structure of an optical module and an optical chip, characterized in that: include: An independently deployed receiving-end component, a stepped metal heat sink, and a silicon-based optical interconnect component mounted on the stepped metal heat sink; Silicon-based optical interconnect components include lasers, silicon optical beam splitters, lens groups, transmittance compensation gaskets, silicon optical modulators, and optical fiber arrays; A coplanar coupling in the direction perpendicular to the optical axis is formed between the light emitting end face of the laser and the incident end face of the silicon optical beam splitter; The silicon optical beam splitter and at least part of the collimating lens in the lens group are fixed on the light-transmitting compensation spacer; The optical fiber array and the silicon optical modulator achieve waveguide matching through active coupling, and the coupling interface between the optical fiber array and the silicon optical modulator is filled with a refractive index matching adhesive layer; The silicon optical modulator and the receiving end component are separated and arranged at least at a preset distance, and the optical fiber array and / or the receiving end component are covered with a metal isolation cover capable of achieving continuous electromagnetic shielding.

2. The packaging structure of the optical module and optical chip according to claim 1, wherein: The incident and output end faces of the silicon optical beam splitter are coated with anti-reflection coatings, and the beam splitting ratio of the silicon optical beam splitter is 1:1, which is used to split the single optical signal output by the laser into two outputs.

3. The packaging structure of the optical module and optical chip according to claim 1, wherein: The light-transmitting compensation spacer forms a thermal expansion matching structure with the silicon optical beam splitter.

4. The packaging structure of the optical module and optical chip according to claim 1, wherein: The edge of the silicon optical beam splitter extends laterally beyond the boundary of the translucent compensation gasket to form a limiting structure covered by a barrier adhesive layer to prevent the solidified colloid from overflowing onto the optical functional surface of the silicon optical beam splitter.

5. The packaging structure of the optical module and optical chip according to claim 3, wherein: The stepped metal heat sink includes: a first stepped platform and a second stepped platform; The first side of the first stepped platform is provided with a laser mounting position for fixing the laser via a silver adhesive patch, and the second side of the first stepped platform is bonded to the surface of the packaging substrate via a thermally-cured thermal adhesive layer; The first side surface of the second stepped platform is provided with a light transmittance compensation gasket mounting position, a partial lens group mounting position and a silicon optical modulator mounting position, wherein the partial lens group mounting position is used to position at least one collimating lens aligned with the output end of the silicon optical beam splitter; The second stepped platform has a height difference with respect to the first stepped platform, and the second side surface of the second stepped platform is integrated with the first stepped platform by mechanical connection or integral molding.

6. The packaging structure of the optical module and optical chip according to claim 5, wherein: A laser-specific heat sink is also provided on the first step platform, which is integrally formed from the same material as the stepped metal heat sink. The laser-specific heat sink extends along the laser optical axis, and the contact area between the side surface of the laser-specific heat sink and the side surface of the laser at least covers the axial projection area corresponding to the laser heating core; Among them, the axial projection area corresponding to the laser heating core is the area covering the multi-quantum well active layer in the laser semiconductor stack structure along the optical axis direction, and the lateral projection boundary of the laser heating core on the plane perpendicular to the optical axis coincides with the electrode installation position of the laser packaging shell.

7. A packaging method for an optical module and an optical chip, characterized in that: A method for manufacturing the packaging structure of the optical module and optical chip according to claim 6, comprising: After the stepped metal heat sink is fixed on the package substrate, the mounting mechanism is driven to mount the laser on the first step platform of the stepped metal heat sink; Use a white light interferometer or a laser displacement sensor to measure the three-dimensional topography data of the laser upper surface and the preset installation area of ​​the silicon optical beam splitter; Selecting a light-transmitting compensation spacer based on the three-dimensional topography data and controlling a vacuum nozzle to mount the selected spacer on the second step platform of the stepped metal heat sink, and mounting a silicon optical beam splitter and at least part of the collimating lens in the lens group on the light-transmitting compensation spacer; Based on the spot distribution data fed back by the microscopic vision system, the nanometer translation stage is driven to adjust the relative position of the laser and the silicon optical beam splitter to achieve submicron coplanar coupling between the laser light output end face and the silicon optical beam splitter incident end face in the direction perpendicular to the optical axis. Control the coordinated motion mechanism of the silicon light modulator and the fiber array. Under the condition of applying a modulation signal, dynamically optimize the waveguide matching position of the silicon light modulator and the fiber array based on the optical power data fed back by the photodetector, and inject refractive index matching glue at the coupling interface. First, the optical path nodes are locally radiated and cured using an ultraviolet light source. Then, the oven is started to perform gradient temperature curing on the entire structure. During the curing process, the deformation of the adhesive layer is monitored in real time and displacement deviations are compensated. Based on the electromagnetic field simulation data, the arrangement path of the receiving end components is generated with the silicon optical modulator as the center. The mounting mechanism is controlled to install two receiving end components according to the preset radius. The metal isolation cover covering the optical fiber array and / or the receiving end component is connected to the heat sink through laser welding to form a closed-loop shielding structure with continuous conductive connection.

8. The packaging method of the optical module and optical chip according to claim 7, wherein: Selecting a light-transmitting compensation gasket based on the three-dimensional topography data and controlling a vacuum nozzle to mount the selected gasket on the second step platform of the stepped metal heat sink, and mounting a silicon optical beam splitter and at least part of the collimating lens in the lens group on the light-transmitting compensation gasket includes: Based on the three-dimensional topography data, the spatial height difference spectrum distribution is obtained through discrete Fourier transform; Based on the peak and valley characteristics of the spatial height difference spectrum distribution, a light-transmitting compensation gasket with the most matching thickness step is selected from the pre-classified compensation gasket library. The gasket edge is designed with a slope transition structure to achieve continuous coverage of the adhesive layer. The mounting mechanism is driven to mount the silicon optical beam splitter on the light-transmitting compensation pad, and the edge is controlled to extend beyond the boundary of the light-transmitting compensation pad to form a ring-shaped overflow groove structure, and the adhesive layer is cured by ultraviolet light exposure to form a limiting structure; After placing at least part of the collimating lenses in the lens group at the output end of the silicon optical beam splitter on the transmittance compensation gasket, a wavefront aberration quantification model is established based on the feedback information of the back-projected light spot to analyze the astigmatism component introduced by the tilt of the lens group. The discrete tilt angle adjustment amount is output according to the wavefront aberration quantification model until the light spot symmetry reaches a preset threshold.

9. The packaging method of the optical module and optical chip according to claim 8, wherein: in, The translucent compensation spacer must meet the following thickness requirements: ； Where argmin is the optimal thickness d selected from the pre-classified compensation gasket library to minimize the objective function opt , d k is the nominal thickness of the kth candidate gasket in the pre-classified gasket library, h t is the target height difference, Ω is the effective area that needs to be compensated for the height, A is the area of ​​region Ω, and Δh(x, y) is the height difference between the upper surface of the laser and the preset mounting area of ​​the silicon optical beam splitter.

10. The packaging method of the optical module and optical chip according to claim 8, wherein: Based on the feedback information of the back-projected light spot, a wavefront aberration quantification model is established to analyze the astigmatism component introduced by the tilt of the lens group. The discrete tilt angle adjustment amount is output according to the wavefront aberration quantification model until the light spot symmetry reaches the preset threshold, including: A reverse calibration beam is projected onto a silicon optical beam splitter. After reflection from a lens group, the output spot image is captured by a CMOS sensor. The spot ellipticity and Strehl ratio are calculated to construct a joint evaluation function. The ellipticity represents the spot shape distortion, and the Strehl ratio represents the diffraction-limited performance of the optical system. Perform Zernike polynomial decomposition on the spot image, establish a wavefront aberration quantification model, extract the coma coefficient related to lens tilt, and suppress interference terms unrelated to astigmatism; The initial tilt angle adjustment is calculated based on the coma coefficient, and combined with the real-time data of the temperature sensor, the thermal expansion compensation correction is performed on the initial tilt angle adjustment; According to the corrected tilt adjustment amount, the nanometer translation stage is driven to gradually adjust the lens tilt angle with a preset step size. After each adjustment step, the ellipticity and Strehl ratio are recalculated and the joint evaluation function value is updated. When the joint evaluation function value is ≤0.05, the iteration is terminated and the lens group position is locked. When the joint evaluation function value is >0.05, the model is updated according to the latest astigmatism coefficient and the next adjustment cycle is entered. in, The joint evaluation function is: ； Where J is the joint evaluation function value, ε is the spot ellipticity, I min is the grayscale peak value in the short axis direction of the light spot, I max is the grayscale peak value in the long axis direction of the light spot, S is the Strehl ratio, is the total light intensity integral of the actual light spot, is the integral of the spot intensity under the ideal diffraction limit; The wavefront aberration quantification model is: ； Where, is the nth order mth term Zernike polynomial basis, used to describe the wavefront phase distribution on the pupil plane, n is the radial order of the polynomial, n=1~6, m is the angular frequency term, m=-n~+n, a nm is the magnitude of the nth-order mth aberration, ρ, is the normalized polar coordinate parameter; The initial tilt adjustment is: ； Where Δθx and Δθy are the initial tilt adjustment values ​​of the x-axis and y-axis respectively, λ is the laser operating wavelength, and η is the equivalent optical magnification of the lens group at the laser operating wavelength λ. is the coma coefficient caused by the X-axis tilt of the lens group The amplitude coefficient of the coma tail is along the negative X direction, is the coma coefficient caused by the Y-axis tilt of the lens group The amplitude coefficient of the coma aberration is along the positive Y direction; The corrected tilt adjustment amount is: ； Where, is a placeholder representing Δθx or Δθy, γ is the thermal expansion compensation coefficient, , α j is the thermal expansion coefficient of the package substrate material, α t is the thermal expansion coefficient of the lens group material, T is the current ambient temperature, and T0 is the calibration temperature, which is 25°C.

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