A SOA butterfly device double-end synchronous automatic coupling welding device and method

Abstract

This application discloses a synchronous automatic coupling welding device and supporting method for SOA butterfly devices, belonging to the field of automated packaging of optoelectronic devices. The device is integrated into a vibration-isolated optical platform and includes a central shell clamping stage, three sets of six-axis displacement stages, a bidirectional TEC temperature-controlled current source, an integrated visual infrared sensor, a dual-channel optical power detection unit, a multi-axis strain protection system for the fixture, and a main control computer. During the coupling stage, the TEC forward cooling stabilizes the chip temperature, while reverse current is applied during welding to form a uniform surface heat source. Infrared thermal imaging collects the temperature in real time to achieve closed-loop temperature control. The left and right six-axis displacement stages are synchronously linked, employing a multi-level iterative 9-point scanning algorithm to complete the alignment of the dual-end lenses in one step, with the average optical power of the dual channels as the optimization target, eliminating the need for step-by-step coupling by flipping the fixture. Strain sensing monitors the stress throughout the entire process, and overload automatic emergency stop protection devices are implemented. This application achieves fully automated production, improves coupling efficiency, reduces welding thermal stress, and significantly improves product optical consistency and yield.

Description

Technical Field

[0001] This application relates to the field of automated packaging technology for optoelectronic devices, specifically to a dual-end synchronous automatic coupling welding equipment and method for SOA butterfly devices, which is applicable to the batch automated packaging of optical devices such as SOA semiconductor optical amplifiers, DFB lasers, SLD superluminescent diodes, and silicon photonic integrated devices. Background Technology

[0002] Optical path coupling and soldering are core processes in the production and packaging of optical devices. SOA (Semiconductor Optical Amplifier) ​​is a dual-ended light-emitting device, typically packaged in a butterfly package. These devices require optimal coupling of both optical paths simultaneously, placing higher demands on coupling accuracy, efficiency, and soldering reliability. Current traditional packaging equipment and processes in the industry have the following shortcomings:

[0003] Traditional equipment often uses single-end sequential coupling, requiring two alignments on both sides, as well as rotation, flipping, or fixture switching. This process is cumbersome, inefficient, and results in poor product consistency. Furthermore, single-end sequential coupling cannot achieve optimal coupling positions on both ends, which can easily lead to decreased optical performance, low product yield, and insufficient reliability.

[0004] In addition, traditional laser welding and hot air welding are localized point heat sources, with concentrated temperature and high thermal stress, which can easily cause damage to optical chips or substrates, aging and failure of internal adhesives, and shorten device life.

[0005] Furthermore, many processes require manual intervention, and the alignment accuracy and welding quality depend on the operator's experience, making it difficult to achieve mass automated production. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this application provides a dual-end synchronous automatic coupling welding device and method for SOA butterfly devices, aiming to solve the following problems: low efficiency of traditional single-end sequential coupling and uneven dual-end coupling; large local heat source thermal stress and severe thermal damage in traditional laser welding and hot air welding; and low degree of automation due to the need for manual intervention in multiple processes.

[0007] To achieve the above objectives, this application adopts the following technical solution: In a first aspect, this application provides a dual-end synchronous automatic coupling welding device for SOA butterfly devices, comprising: A central housing clamping platform is used to fix a housing pre-installed with a TEC. The central housing clamping platform integrates a power supply clamp for supplying power to the TEC inside the housing and the COS device to be placed by contacting the housing pins. A six-axis displacement stage, equipped with a COS fixture, is used to clamp COS devices from the material pick-up position and move them to the welding station inside the tube shell, and place them on the TEC. The left and right six-axis displacement stages are respectively arranged on both sides of the middle six-axis displacement stage, and are used to clamp and move the left and right lenses respectively to complete the synchronous alignment of the double-ended optical paths. A device bias current source is electrically connected to the power supply fixture to provide bias current to the COS device, so that the optical chip of the COS device emits light for coupling alignment; The TEC temperature control current source is electrically connected to the power supply fixture and is used to control the working state of the TEC: in the coupling stage, forward power is applied for cooling to maintain a constant temperature of the optical chip; in the welding stage, reverse power is applied for heating to melt the solder in a preset position inside the tube shell. The integrated vision and infrared temperature measurement sensing system includes an industrial camera and an infrared thermal imaging camera, which are used to guide alignment and monitor welding temperature, respectively. The left and right optical power detection units are respectively located at both ends of the optical path to detect the dual-end output optical power in real time and provide feedback for coupling alignment. The main control computer communicates with the above modules and is used to control the modules to work together to complete the entire process of material picking, placement, coupling alignment, welding and testing according to a preset timing sequence.

[0008] Optionally, during the coupling stage, with the goal of maximizing the average optical power of the left and right dual channels, the left six-axis displacement stage and the right six-axis displacement stage are synchronously linked for scanning to achieve synchronous optimal alignment of the dual lenses and the optical paths at both ends of the optical chip.

[0009] Optionally, the infrared thermal imaging camera collects the temperature distribution of the welding area in real time and feeds it back to the main control computer. The main control computer adjusts the reverse power and power-on duration of the TEC temperature control current source in a closed loop according to the temperature distribution to maintain the welding temperature within a preset range.

[0010] Optionally, the power supply fixture includes a power-on probe. When the six-axis displacement stage places the COS device on the TEC, the power-on probe is connected to the electrodes of the COS device, and the device bias current source can provide bias current to the COS device through the power-on probe.

[0011] Optionally, it also includes a multi-axis strain sensing system, which is installed on the COS fixture to detect the stress state of the COS fixture in real time and triggers emergency braking when the detected stress exceeds a preset threshold.

[0012] Secondly, embodiments of this application also provide a method for synchronous automatic coupling welding of SOA butterfly devices at both ends. This method is performed using the equipment described in the first aspect and includes the following steps: S1: System initialization: All displacement stages return to zero, and all detection units start and complete parameter configuration; S2: Automatic material finding: The industrial camera positions the COS device picking position, and the six-axis displacement stage moves to the picking position; S3: Automatic clamping: The COS fixture clamps the COS device; S4: Automatic placement: The six-axis displacement stage moves the COS device to the welding station inside the tube shell and places it on the TEC, whereby the COS device contacts the solder at a preset position inside the tube shell; S5: Automatic power-on: The bias current source of the device applies a bias current to the COS device to make the optical chip emit light. The left optical power detection unit and the right optical power detection unit read the initial optical power at the left and right ends respectively. The TEC temperature control current source is powered on in the forward direction to cool and maintain the optical chip temperature constant. S6: Dual-end synchronous coupling: The left six-axis displacement stage and the right six-axis displacement stage scan synchronously and in conjunction, aiming to maximize the average optical power of the left and right dual channels, and lock the optimal coupling position of the left and right lenses. S7: TEC reverse heating welding: The bias current source of the device is turned off, and the temperature control current source of the TEC is reversed to heat the TEC. The solder in the preset position inside the tube is heated and melted. The infrared thermal imaging camera collects the welding temperature in real time and feeds it back to the main control computer to realize closed-loop temperature control. S8: Post-welding treatment: After welding is completed, the TEC temperature-controlled current source stops supplying power to the TEC and waits for the solder to cool and solidify; S9: Finished Product Inspection: The bias current source of the device is re-powered, and the left optical power detection unit and the right optical power detection unit read the current optical power at both ends, compare the difference in optical power before and after welding, and output the detection result.

[0013] Optionally, the dual-end synchronous coupling in step S6 is implemented using a multi-level iterative 9-point scanning algorithm, specifically including: A 3×3 two-dimensional grid is constructed with the current coupling position as the center. Each point in the grid is traversed and the corresponding left and right dual-channel optical power values ​​are recorded. The scanning range is gradually reduced with the average dual-channel optical power as the criterion, and the global optimal coupling point is iteratively approached.

[0014] Optionally, the closed-loop temperature control in step S7 specifically includes: The infrared thermal imaging camera collects a two-dimensional temperature matrix of the welding area in real time. The main control computer adjusts the reverse power and duration of the TEC temperature control current source in a closed loop according to the highest temperature value in the two-dimensional temperature matrix, so that the welding temperature is maintained within a preset range.

[0015] Optionally, strain sensing protection steps are also included: The multi-axis strain sensing system monitors the stress state of the COS fixture in real time throughout the entire process of material handling, clamping, coupling, and welding. When the instantaneous stress exceeds the preset protection threshold, the main control computer controls all displacement stages to immediately perform emergency braking.

[0016] Optionally, the post-welding processing in step S8 further includes: after the solder melts, the left six-axis displacement stage and the right six-axis displacement stage drive the left lens and the right lens to reciprocate to smooth the molten solder.

[0017] Compared with the prior art, this application has the following beneficial effects: During the coupling phase, the optimal alignment of the two lenses can be completed in one go by controlling the synchronous linkage of the left and right six-axis displacement stages. There is no need to change, rotate or flip the fixtures, and the coupling efficiency is significantly improved compared with the traditional single-end sequential coupling.

[0018] In addition, during the welding stage, the TEC can be converted into a uniform surface heating source by reverse power supply, replacing the localized point heat source of traditional laser welding and hot air welding. This results in a smaller heat-affected zone and lower welding thermal stress, which can effectively protect the optical chip and internal adhesive layer of the COS device.

[0019] In addition, the infrared thermal imaging camera can collect the temperature distribution of the welding area in real time, so that the main control computer can adjust the TEC heating power and duration in a closed loop according to the temperature data to prevent the internal adhesive layer of the COS device from overheating and failing.

[0020] The entire process can be fully automated through software, enabling automatic execution of all operations including material handling, placement, coupling, welding, and testing, making it suitable for mass production in industrial settings. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. Furthermore, these drawings and textual descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this application to those skilled in the art by reference to specific embodiments.

[0022] Figure 1 This is a module architecture diagram of the SOA butterfly device dual-end synchronous automatic coupling welding equipment provided in the embodiments of this application; Figure 2 This is a side view of the structure of the six-axis displacement stage of the SOA butterfly device double-end synchronous automatic coupling welding equipment provided in the embodiments of this application; Figure 3 This is a top view of the six-axis displacement stage of the SOA butterfly device double-end synchronous automatic coupling welding equipment provided in the embodiments of this application; Figure 4 A flowchart of the SOA butterfly device dual-end synchronous automatic coupling welding method provided in the embodiments of this application. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0024] To facilitate understanding of the technical solution of this application, the following explains some of the core concepts involved in this application: 1. COS (Chip on Substrate) device: refers to a semi-finished device obtained using Chip on Substrate packaging technology. In this application, it refers to a semi-finished assembly in which the optical chip has been soldered or mounted on a substrate, including the optical chip and its mounting substrate, and is the core optical element to be packaged. The optical chip is the core component responsible for light emission in the COS device. It is compatible with DFB, SLD, and silicon photonic integrated dual-ended light-emitting devices of the same architecture.

[0025] 2. Package: The outer casing of an optical device, used to further encapsulate the COS device. Specifically, it houses the COS device, TEC, lens, and other components, and provides external electrical interfaces (pins). The pins are the electrical pathways for the internal components, responsible for transmitting external current to the internal TEC and COS device.

[0026] 3. TEC (Thermoelectric Cooler): A semiconductor device that utilizes the Peltier effect to achieve cooling or heating. The TEC is pre-fixed to the bottom of the housing during the housing assembly stage, serving as a mounting platform for the COS device. It cools when forward-biased and heats when reverse-biased.

[0027] 4. C-lens: This is a collimating coupling lens used to match the optical output path of the optical chip at both ends of the COS device, thereby maximizing optical power coupling.

[0028] 5. Optical coupling: refers to the process of precisely aligning the light-emitting surface of the optical chip with the optical axis of the C-lens (hereinafter referred to as the lens).

[0029] 6. Dual-End Synchronous Coupling: SOA is a dual-end light-emitting device. Dual-end synchronous coupling means that the left and right lenses are precisely aligned with the light-emitting surface at the same time. This is different from the traditional single-end sequential coupling (aligning one side first and then the other side).

[0030] Example 1 To address the problems of existing technical solutions, this embodiment provides a dual-end synchronous automatic coupling welding device for SOA butterfly devices. All hardware of this device is integrated into a high-precision, stable pneumatic vibration isolation optical platform, equipped with Python fully automatic control software for layered hardware management, and incorporates multiple sets of dedicated control algorithms. For example... Figures 1-3 As shown, the device mainly includes the following components: a central tube clamping stage, a central six-axis displacement stage, a left six-axis displacement stage, a right six-axis displacement stage, a stepper motor drive module, a device bias current source, a TEC temperature control current source, an integrated vision and infrared temperature measurement sensing system, a left optical power detection unit, a right optical power detection unit, a clamp pneumatic switch, and a main control computer. Optionally, it also includes a multi-axis strain sensing system. The hardware connections are categorized into three types: communication connections (…). Figure 1 (double-headed arrow in the image), drive connection ( Figure 1 (without arrows or dashed lines) and optical path connection ( Figure 1 (with dashed arrows in the text); detailed implementation details for each module are as follows: Module 1: Central Tube Shell Clamping Platform The function of this module is to stably clamp and fix the pre-installed TEC and solder in the butterfly-shaped shell. The central shell clamping platform integrates a power supply fixture, which is used to supply power to the TEC and the COS device to be placed inside the shell through the pins that contact the shell. This enables two-way power supply to the TEC and COS device, while also providing auxiliary heat dissipation function to support the placement and positioning of the COS device.

[0031] In practical implementation, the central tube holder is equipped with a quick-change clamping fixture, compatible with tubes of different shapes and sizes, such as 8-pin / 14-pin standard butterfly tubes and custom box tubes. The power supply fixture has two conductive structures: one is a metal spring contacting the outer pin of the tube, connecting to the TEC temperature-controlled current source; the other integrates a vertical lifting power-on probe. After the six-axis displacement stage places the COS device in place, the probe descends to contact the electrodes of the COS device, thereby connecting to the bias current source. A heat dissipation groove can be reserved at the bottom of the clamping fixture to assist in heat dissipation and cooling during the TEC coupling stage. A COS loading and unloading auxiliary platform can be integrated on the side of the central tube holder to realize continuous material flow.

[0032] It is important to note that after changing the clamping fixture, the coordinates of the material picking and welding stations need to be recalibrated using an industrial camera to avoid COS placement misalignment; the height of the power-on probe can be adjusted via software parameters to prevent the probe from excessively pressing down and damaging the COS electrode.

[0033] The central housing clamping platform is compatible with multiple housing specifications and can simultaneously complete the power supply connection of TEC and COS devices, simplifying the equipment material adaptation process.

[0034] It is understandable that, in addition to the vertical lifting structure, the power supply probe can also use a side-push horizontal probe to contact the COS electrode; the tube clamping fixture can be replaced with other forms, such as a vacuum adsorption clamping structure.

[0035] Module 2: Medium six-axis displacement stage (equipped with COS fixture and pneumatic switch) This module is designed to support the COS device in the entire process of picking up, transferring, and placing the device. It precisely controls the spatial position of the COS device with six degrees of freedom, and uses pneumatic switches to automatically control the opening and closing of the fixture.

[0036] In practical implementation, the displacement stage has six-axis motion capabilities: X / Y / Z translation and θx / θy / θz rotation, with a stroke of ±12mm, a positioning resolution of 10nm, and an angular resolution of 0.0002°. A stepper motor drive module outputs trapezoidal acceleration and deceleration commands to eliminate start-stop vibration. The COS clamp is controlled by an electro-pneumatic switch for clamping / releasing, with flexible buffer pads attached to the inner side of the grippers. The COS clamp body can optionally be equipped with a multi-axis strain sensing system with an accuracy of ±1με. An independent software thread continuously collects micro-strain data to monitor the stress state of the COS clamp in real time. After material removal, a small-step reciprocating clamping action is performed to confirm the COS clamp is secure. The displacement stage's motion coordinates are uniformly managed by the underlying HW_MTP_xxx driver library, supporting absolute coordinates, relative coordinates, single-step manual, and continuous automatic motion modes.

[0037] It should be noted that the strain protection threshold of the multi-axis strain sensing system can be customized in the software interface (normal ±5με). When the strain exceeds the limit, all displacement stages will stop simultaneously. It is not possible to lock a single axis individually. The pneumatic clamp air pressure needs to be maintained at 0.4~0.6MPa. Insufficient air pressure will cause the clamp to slip.

[0038] This module enables fully automated and precise transfer of COS devices. A multi-axis strain sensing system allows for real-time monitoring of clamping forces throughout the entire process, preventing damage to the optical chips caused by collisions or excessive clamping force.

[0039] It is understandable that, apart from stepper motors, the six-axis displacement stage drive can be replaced with a piezoelectric ceramic micro-displacement platform to further improve positioning accuracy; the pneumatic gripper can be replaced with an electric servo gripper.

[0040] Module 3: Left six-axis translation stage, right six-axis translation stage The function of this module is to symmetrically clamp the C-lens lenses on both sides, synchronously perform multi-axis scanning motion, complete the synchronous coupling and fine-tuning of the optical path at both ends, and achieve optimal balanced optical power for the left and right dual channels.

[0041] In practice, the two sets of displacement stages have identical structural parameters and are symmetrically arranged on the left and right sides of the six-axis displacement stage. Each displacement stage is equipped with an independent lens fixture, which can be quickly replaced to fit different specifications of C-lens lenses. During the coupling phase, the two sets of displacement stages receive synchronous motion commands from the main control computer and execute 3×3 grid scanning synchronously. After welding is completed, they can receive reciprocating translation commands to move the lenses and smooth out the molten solder. The motion trajectory is uniformly and synchronously output by the stepper motor drive module to ensure that the movement sequence of the left and right lenses is completely matched.

[0042] It should be noted that the left and right six-axis displacement stages are calibrated for coaxiality before leaving the factory. After changing the lens fixture, the optical path calibration must be performed again. During synchronous scanning, the step size and iteration cycle of the left and right displacement stages are completely consistent, and the motion parameters of one side cannot be modified separately.

[0043] This module enables simultaneous optimization of the optical path of both lenses, eliminating the need for two separate single-sided coupling operations and significantly improving coupling efficiency.

[0044] It is understandable that the left and right six-axis displacement stage can be replaced by a linear motor driven precision displacement platform, which has a faster motion response speed; the lens fixture can be integrated with a vacuum adsorption structure to replace the mechanical gripper.

[0045] Module 4: Stepper Motor Drive Module The function of this module is to receive motion commands from the main control computer, convert them into drive pulses to control the motion speed, displacement distance, and start / stop sequence of each axis of the three groups of six-axis displacement stages, and to use a trapezoidal acceleration / deceleration algorithm to suppress mechanical vibration.

[0046] In practical implementation, the drive module communicates with the main control computer via RS232 serial port and is directly connected to the motors of three sets of six-axis displacement stages via pulse control lines; it has a built-in trapezoidal acceleration and deceleration motion curve, and automatically reduces the motion speed during the start and stop phases of the displacement stage to avoid jitter caused by high-speed start and stop; it supports two modes: single-axis independent control and multi-axis synchronous linkage; the underlying drive library provides real-time feedback on the origin, limit, and emergency stop status of each axis to the main control computer software.

[0047] It should be noted that after the displacement stage triggers the hard limit, the drive module automatically locks the motor output and needs to be manually returned to zero to resume operation; in synchronous linkage mode, the pulse output timing of the left and right displacement stages is strictly aligned to avoid asynchronous lens movement.

[0048] This module enables precise, stable, and synchronous multi-axis motion, eliminating the interference of mechanical vibration on the optical path coupling accuracy.

[0049] It is understandable that, in addition to RS232, the motor drive communication interface can be replaced with EtherCAT industrial bus to achieve high-speed real-time motion control.

[0050] Module 5: Device Bias Current Source The function of this module is to provide a stable and adjustable DC bias current for the COS optical chip, drive the optical chip to continuously emit light during the coupling stage, and ensure stable acquisition of dual-end optical power detection data; and shut down the output when the power is turned off during the welding stage.

[0051] In practical implementation, the current source is connected to the power-on probe of the central tube holder via a wire, and the current output range is continuously adjustable from 0 to 500mA; it supports pulsed current output mode, which is synchronized with the optical power detection unit to quickly collect data and avoid the optical chip temperature rise caused by continuous power supply; the main control computer software can control the current on and off and the output current with one click; the hardware has overcurrent protection, and the output is automatically cut off when the current exceeds the upper limit to prevent the optical chip from burning out.

[0052] It is important to note that the bias current output must be turned off before the soldering stage to avoid damage to the optical chip due to overcurrent at high temperatures.

[0053] This module can stably drive the optical chip to emit light, provide real-time optical power feedback signals for optical path coupling, and reduce the interference of optical chip temperature rise in pulse mode.

[0054] It is understandable that the bias current source can be replaced with a programmable AC pulse current source to adapt to the driving requirements of optical chips in special bands.

[0055] Module 6: TEC Temperature Controlled Current Source This module is designed to output controllable current in both directions, switching between TEC cooling and heating modes. During the coupling phase, forward power is applied for cooling and temperature control, while during the welding phase, reverse power is applied to generate a uniform surface heat source to melt the solder. It also works in conjunction with infrared temperature measurement data to achieve closed-loop regulation of output power and power-on duration.

[0056] In practical implementation, the current source is connected to the central tube shell clamping stage tube shell pins with bidirectional current output range of ±3A; during the coupling stage, the forward current output is used to attach the TEC cold end to the substrate of the COS device to stabilize the temperature of the optical chip (the optical chip will heat up when it emits light), thereby suppressing the temperature drift of the optical power; during the welding stage, the reverse current is switched, and the original cold end is turned into the heating surface to form a uniform surface heat source over the entire area.

[0057] It should be noted that the bias current output should not be superimposed during the reverse heating stage of the TEC to prevent the device from failing due to high temperature and charge. The internal resistance of different batches of TECs varies, and the software can adaptively adjust the heating power without the need for repeated manual calibration.

[0058] This module enables a single hardware setup to simultaneously perform both constant temperature and welding heating functions. The uniform surface heat source significantly reduces welding thermal stress and is compatible with TEC materials of different specifications.

[0059] It is understandable that the TEC temperature control current source can integrate multiple independent output channels to simultaneously control multiple TEC temperature controls within the housing.

[0060] Module 7: Multiaxial Strain Sensing System This module is optional. Its function is to collect multi-directional micro-strain data of the COS fixture in real time, identify abnormal forces such as clamping overload, lens collision, and material misalignment, and trigger the emergency braking of the full displacement stage when the detected force exceeds the preset threshold to protect components such as the optical chip, COS fixture, and optical path platform.

[0061] In practical implementation, multi-axis strain sensors are integrated into the root of the COS fixture jaws, with a measurement accuracy of ±1με; an independent background thread reads strain values ​​in a loop without occupying the computing power of the coupling and temperature control main threads; the software interface can display triaxial strain curves in real time and supports custom protection thresholds (default ±5με); when the instantaneous strain exceeds the threshold, the underlying motion drive library directly issues an emergency stop command, and all displacement stage motors are immediately locked; continuous monitoring throughout the entire process of material handling, placement, coupling, and welding, with uninterrupted protection.

[0062] It is important to note that strain sensors require monthly zero-point calibration after prolonged use to prevent temperature drift from causing false triggering and emergency stop; wear of the buffer pads will increase the strain value and require periodic replacement.

[0063] This module enables full-process hardware collision protection, reduces the limitations of material processing tolerances on equipment operation, and minimizes failures such as optical chip scrap and fixture deformation.

[0064] It is understandable that the strain sensing system can be replaced by a pressure sensing array to directly collect the clamping pressure value of the fixture to achieve overload protection.

[0065] Module 8: Integrated Visual and Infrared Thermometry Sensing System This module is divided into an industrial camera subunit and an infrared thermal imaging camera subunit, which work together to complete visual positioning and welding temperature field monitoring.

[0066] The function of the industrial camera subunit is to: complete the visual positioning of the COS picking position, the correction of the COS placement position, the visual guidance of lens alignment, and output the image coordinates to the main control computer software to calculate the motion trajectory of the displacement stage.

[0067] In practice, it is equipped with two 2-megapixel industrial cameras on the top and side, with adjustable focus lenses; the underlying HW_CAM_xxx driver library acquires images in real time, and the software has a built-in image recognition algorithm to automatically identify the COS contour, electrode, and tube shell solder area; before picking up the material, the camera takes a picture of the picking tray and automatically calculates the COS center coordinates and sends them to the six-axis displacement stage.

[0068] It is important to note that industrial camera lenses need to be cleaned regularly, as dust can reduce positioning and recognition accuracy.

[0069] It is understandable that industrial cameras can be upgraded to 5-megapixel high-resolution cameras, paired with telecentric lenses to accommodate the positioning of tiny COS devices.

[0070] The infrared thermal imaging camera subunit is responsible for acquiring a two-dimensional temperature matrix of the welding area in real time, feeding back the highest temperature value to the main control computer, and adjusting the TEC reverse heating power and heating duration in a closed loop to maintain the welding temperature within a preset range and prevent overheating and aging of the internal adhesive layer. In practice, the welding temperature field can be monitored visually.

[0071] In practical implementation, a 32×24 dot matrix infrared temperature measurement array is used, with a temperature measurement range of 50~300℃ and a temperature control accuracy of ±1℃. An independent HW_IR_xxx thread continuously collects temperature data and extracts the peak temperature within the matrix as the basis for closed-loop control. The software interface renders the welding temperature thermal map in real time and automatically records the entire temperature curve of each device for production traceability.

[0072] It is important to note that the infrared lens must not be obstructed. Molten solder volatiles adhering to the lens will cause temperature measurement deviations and must be cleaned promptly. The upper limit of the welding temperature should not exceed 180℃ to avoid lens adhesive failure.

[0073] It is understandable that infrared thermal imaging cameras can be replaced with multi-point infrared temperature measurement probe arrays to reduce equipment hardware costs.

[0074] Module 9: Left optical power detection unit, right optical power detection unit The function of this module is to synchronously acquire the output optical power of the left and right ends of the SOA device in real time, provide core judgment data for the multi-level iterative 9-point scanning coupling algorithm, and determine the yield of the finished product by comparing the power difference before and after welding.

[0075] In practical implementation, the left and right detection units are symmetrically arranged at both ends of the optical path. The hardware options include optical power probes and integrating spheres, and can be expanded to include spectral analyzers and spot analyzers. The optical path uses fiber optic connectors with collimators to achieve optical coupling. One end of the fiber is fixed to the lens side of the left and right displacement stages, and the other end is connected to the optical power detection unit. The software uses pulsed current synchronous acquisition logic to read the optical power value synchronously with the bias current pulse, providing feedback for coupling alignment. The data fitting algorithm eliminates power fluctuations caused by optical chip temperature rise and six-axis displacement stage vibration. The values ​​of left-side power Pleft and right-side power Pright are output in real time, and the dual-channel mean Pavg = (Pleft + Pright) / 2 is automatically calculated with the constraint |Pleft - Pright| < 3.

[0076] It is important to note that the fiber optic connector end face needs to be cleaned regularly, as dirt on the end face will cause the optical power detection value to be lower than expected; during the coupling scanning stage, the optical power sampling frequency should be ≥10 times / second to ensure the accuracy of iterative optimization.

[0077] This module synchronously acquires dual-end optical power data, supports dual-end synchronous coupling algorithm calculations, and enables automatic detection of the optical performance of the finished product after welding.

[0078] It is understandable that the optical power detection unit can be replaced with a high-speed photodetector to improve the optical power acquisition response speed.

[0079] Module 10: Clamp Pneumatic Switch The function of this module is to output a pneumatic signal via electrical control to control the COS fixture jaws to automatically clamp and release, thereby completing the automatic picking and unloading of COS devices.

[0080] In practice, the main control computer software uses the underlying HW_PS_xxx driver to output switch signals to control the solenoid valve to open and close the air path; the software can customize the clamping holding time, and extend the clamping time after material removal to prevent material slippage; the matching air pressure sensor monitors the air path pressure in real time, and pop-up alarms are issued when the air pressure is lower than the threshold.

[0081] It is important to note that the air lines need to be drained regularly, as moisture can corrode the solenoid valves; when the machine is shut down for an extended period of time, the air pressure in the clamps should be released to prevent the grippers from deforming due to prolonged pressure.

[0082] It is understandable that the pneumatic switch can be replaced by an electric servo drive module to precisely control the clamping force.

[0083] Module 11: Main control computer (with fully automatic process control software) This module is the core of the equipment's overall control. It connects to all hardware through multiple communication interfaces, communicates with the above modules, coordinates and schedules each module according to a preset timing sequence, runs the core software algorithms for coupling, temperature control, and strain protection, executes a fully automated encapsulation process, stores production data, and uploads it to the cloud for traceability.

[0084] The complete implementation details of the software layering are as follows: Interface layer (GUI_XX): Implements window rendering, operation buttons, operation logs, real-time display of industrial camera / infrared thermal images, equipment parameter formula configuration, and visualization of finished product test results; supports storage of multiple product formulas, switching between different specifications of COS devices, and one-click loading of tube and shell parameters.

[0085] Automatic Process Layer (AUTO_XXX): Encapsulates complete automated processes Auto0~Auto8, covering all processes including system reset, material search, clamping, placement, power-on, coupling, welding, cooling, finished product inspection, and equipment reset; it has a built-in AUTO_align_XXX coupling algorithm module that runs multi-level iterative 9-point scanning optimization logic.

[0086] Low-level hardware driver layer: HW_MTP_xxx: Used for driving three sets of six-axis displacement stages, controlling motion, homing, emergency stop, and coordinate verification; HW_IR_xxx / HW_CAM_xxx: Drivers used for infrared temperature measurement and industrial camera image acquisition; HW_SE_xxx: Drivers for real-time data acquisition of multi-axis strain sensing; HW_PS_xxx: Used for driving pneumatic clamp switches; Dedicated communication drivers for current source and optical power detection units enable reading and writing of current and optical power parameters.

[0087] The core supporting algorithms are as follows: Multi-level iterative 9-point scanning coupling algorithm: Construct a 3×3 two-dimensional grid traversal based on the current lens position, record all point pavg, select the optimal point to reduce the scanning step size iterates, and iterate up to 7 rounds to achieve 10nm accuracy; dual-end data filtering and fitting eliminate power fluctuation interference and shorten the judgment waiting time.

[0088] Independent thread strain overload protection algorithm: Separate the main thread to monitor strain in real time, trigger emergency stop without delay when hardware failure occurs, and prevent software from freezing and failing.

[0089] Independent thread infrared closed-loop temperature control algorithm: continuously monitors the welding temperature matrix, dynamically adjusts TEC heating power and duration, and stabilizes the welding temperature range.

[0090] Pulse-type synchronous optical power acquisition algorithm: The bias current pulse output synchronously acquires optical power, avoiding power drift error caused by continuous power-on temperature rise of the optical chip.

[0091] Communication and data storage are as follows: The communication interface supports USB, RS232, RS485, Ethernet, and GPIB. In a typical implementation, a USB docking station and a USB-RS232 cable are used to connect all the hardware. The coupling coordinates, welding temperature curves, optical power differences, and strain data of each device are bound to the product serial number and stored locally, and automatically uploaded to the cloud server to support traceability and query of the entire production process.

[0092] It is important to note that the hardware communication cable must not be disconnected directly during software operation; the device must be reset and the hardware must be powered off first. After modifying the product formula, it must be saved, and the new parameters will be automatically loaded upon restarting the process.

[0093] This module enables unified management of the hardware timing of all equipment, integrates a complete set of algorithms for coupling, temperature control, and protection, and achieves one-click automated mass production with traceable production data.

[0094] It is understandable that the main control computer software can be ported to embedded industrial control computer firmware to replace desktop computers and reduce the size of the equipment; cloud storage can be replaced with local database storage to adapt to production line scenarios without external network access.

[0095] Module 12: High-precision stabilized optical platform The function of this module is to support all hardware units, and the aerodynamic vibration isolation structure isolates ground and motor vibration interference, ensuring the stability of the 10nm-level precision coupled optical path.

[0096] In practice, the platform surface has pre-embedded standard threaded holes, and all six-axis displacement stages, sensing units, clamping stages, etc. are rigidly fixed by bolts; built-in pneumatic shock-absorbing airbags automatically adjust the platform surface level in real time; the platform surface material is made of high-rigidity cast iron to reduce the probability of deformation.

[0097] It should be noted that striking or pressing the optical platform surface is prohibited during equipment operation; the platform's automatic leveling program should be started before powering on each day.

[0098] It is understandable that a high-precision stable optical platform can be replaced by a passive damping vibration isolation platform, eliminating the need for pneumatic air supply equipment.

[0099] Example 2 Based on the aforementioned dual-end synchronous automatic coupling welding equipment, this embodiment provides a dual-end synchronous automatic coupling welding method for SOA butterfly devices, such as... Figure 4 As shown, the method includes the following steps: S1: System initialization: All displacement stages return to zero, and all detection units start and complete parameter configuration.

[0100] The purpose of this step is to complete the equipment hardware self-test and benchmark reset, uniformly initialize the hardware parameters of each sensor, motion, and current, eliminate residual coordinates and parameter interference from the previous production, and establish a benchmark for the automated process.

[0101] In practice, the main control computer software issues a reset command, and the stepper motor drive module controls all axes of the left / center / right six-axis displacement stage to automatically return to the mechanical origin; the vision and infrared integrated system starts the camera and infrared temperature measurement array, and completes the self-test of the image and temperature acquisition channels; the output of the device bias current source and TEC temperature control current source is cleared to zero, and the current output is turned off; the optical power detection unit starts optical path acquisition and performs zero-point calibration; the multi-axis strain sensing system initializes the strain zero point; the software loads the current product formula and imports parameters such as COS device size, coupling iteration round, welding temperature range, and strain protection threshold; after all hardware self-tests are completed, the software pops up a message indicating that initialization is complete, and only then can the subsequent automatic process be started.

[0102] It is important to note that the moving parts should not be touched during the zeroing process of the displacement stage to avoid displacement of the origin. If the hardware self-test fails, the software will automatically pop up a window to mark the faulty hardware. Communication and power supply need to be checked and re-initialized.

[0103] This step unifies the baseline status of all hardware on the equipment, identifies hardware communication and power supply faults in advance, and avoids production downtime.

[0104] It is understandable that, in addition to mechanical origin reset, the zeroing method of the displacement stage can use visual-assisted coordinate calibration to achieve soft zeroing, simplifying the mechanical limit structure of the equipment.

[0105] S2: Automatic material finding: The industrial camera positions the COS component picking position, and the six-axis displacement stage moves to the picking position.

[0106] The purpose of this step is to use visual image recognition to lock the coordinates of the COS device in the picking position (e.g., the tray), drive the six-axis displacement stage to move precisely to the picking position, and complete the pre-positioning preparation for material positioning.

[0107] In practice, the upper industrial camera captures images of the material tray, the underlying image recognition algorithm extracts the outline of the COS device, and calculates the coordinates of the COS center plane. The main control computer converts the coordinates into X / Y axis motion commands for the six-axis displacement stage, and the stepper motor drive module outputs trapezoidal acceleration and deceleration pulses to drive the six-axis displacement stage to move smoothly to the material picking coordinates. After the movement is completed, the side industrial camera takes a second picture to verify the position of the COS device. If the coordinate deviation exceeds the threshold, the displacement stage position is automatically fine-tuned.

[0108] It should be noted that if the pallet material is misaligned, the image recognition will determine that the material search has failed, and the pallet position must be manually adjusted before the material search is retried; the camera lens must be under sufficient ambient light to avoid image recognition failure.

[0109] This step eliminates the need for manual alignment; the visual system automatically identifies the material coordinates, enabling automatic positioning and material handling of COS devices.

[0110] It is understandable that, in addition to 2D industrial camera vision recognition, material positioning can be combined with laser contour sensors to achieve precise 3D spatial coordinate positioning.

[0111] S3: Automatic clamping: COS clamps COS devices; synchronously performs strain sensing protection real-time monitoring.

[0112] The purpose of this step is to control the pneumatic clamp to stably hold the COS device, and to simultaneously collect the clamp strain data to confirm that the clamping status is normal, thereby avoiding the risks of clamping slippage and overload.

[0113] In practice, the main control computer software issues a pneumatic switch clamping command, the solenoid valve opens the air path, and the clamping jaws close to clamp the COS; the multi-axis strain sensing system collects triaxial micro-strain values ​​in real time, and after the software determines that the strain is within the normal clamping range, the process continues; additional small-step reciprocating clamping action is performed to verify that the COS is not loose or slipping; if the strain value exceeds the protection threshold, all displacement stages are immediately triggered to stop, and a pop-up window prompts clamping overload.

[0114] It should be noted that wear on the gripper buffer pads can cause abnormal strain values, and they need to be replaced regularly; strain data is recorded throughout the clamping process and stored in conjunction with the product serial number.

[0115] This step automates the gripping of COS devices, simultaneously verifies the clamping force, and prevents materials from falling or the optical chip from being crushed and damaged during the gripping process.

[0116] It is understandable that, in addition to pneumatic drive, the clamping action of the fixture can be precisely controlled by electric servo grippers to control the clamping force.

[0117] S4: Automatic Placement: The six-axis displacement stage moves the COS device to the soldering station inside the housing and places it on the TEC. The COS device contacts the solder at the preset position inside the housing.

[0118] The purpose of this step is to transfer the clamped COS device to the welding station inside the butterfly-shaped tube shell, precisely aligning it with the TEC cooling surface and the pre-set solder, thus establishing the hardware foundation for subsequent power-on, coupling, and welding.

[0119] In practice, the six-axis displacement stage receives the three-dimensional coordinates of the welding station from the main control computer and moves synchronously along all six axes to the inside of the tube shell. The side industrial camera captures the relative position of the COS device and the tube shell in real time and automatically fine-tunes the X / Y / θ axes to eliminate placement misalignment. The Z-axis of the displacement stage slowly descends to smoothly attach the substrate of the COS device to the TEC surface, and the bottom electrode of the COS device makes full contact with the pre-set solder on the tube shell. After placement, the power-on probe descends to attach to the COS electrode, completing the physical connection of the power supply path.

[0120] It is important to note that the Z-axis descent speed needs to be controlled at a low speed to avoid the COS device substrate hitting the TEC with great force and causing damage to the optical chip; when solder is missing, the visual recognition will pop up an alarm and stop the process to wait for manual solder replenishment.

[0121] This step ensures precise positioning of the COS device inside the casing and simultaneous activation of the power supply probes, eliminating the need for manual alignment.

[0122] It is understandable that, in addition to 2D visual correction, the placement and positioning of COS devices can be achieved by integrating a laser rangefinder to detect the bonding gap between COS and TEC.

[0123] S5: Automatic power-on: The device bias current source applies bias current to the COS device to make the optical chip emit light. The left optical power detection unit and the right optical power detection unit read the initial optical power at the left and right ends respectively. The TEC temperature control current source is powered on in the forward direction to cool and maintain the optical chip temperature constant.

[0124] The purpose of this step is to conduct the driving current of the COS optical chip to make it emit light, and to simultaneously collect the initial dual-end optical power before welding as a reference value; the TEC forward cooling stabilizes the temperature of the optical chip, eliminates the optical power drift caused by temperature rise, and ensures the accuracy of the coupling scan data.

[0125] In practical implementation, the main control computer issues a command to turn on the device bias current source and outputs the preset current value of the recipe; a pulse current output mode is adopted to synchronously trigger the left and right optical power detection units to collect the initial P left and P right values ​​and store them as reference data before welding; the TEC temperature control current source outputs a constant current in the positive direction, and the TEC cold end continuously cools the substrate of the COS device; the infrared thermal imaging camera synchronously collects the temperature of the photochip area to assist in monitoring the constant temperature effect; the software calculates the average optical power of the dual channels in real time, determines that the photochip is emitting light normally, and if there is no light emission fault, it enters the coupling process.

[0126] It is important to note that the TEC forward cooling process continues until the coupling process is completed, and the power must not be interrupted midway.

[0127] This step establishes the active light-emitting optical path required for coupling, collects the original optical power reference before welding, and ensures stable and reliable coupling optimization data in a constant temperature environment.

[0128] It is understandable that, in addition to pulse output, the bias current output mode can use constant DC continuous output, which is suitable for low-power optical chips with minimal optical power fluctuations.

[0129] S6: Dual-end synchronous coupling: The left and right six-axis displacement stages are synchronously linked for scanning, aiming to maximize the average optical power of the left and right dual channels, and locking the optimal coupling position of the left and right lenses; a multi-level iterative 9-point scanning algorithm is used to perform optimization.

[0130] The purpose of this step is to synchronously drive the scanning optical path of both lenses, iteratively optimize with the average optical power at both ends as the optimal target, and complete the synchronous alignment of the left and right lenses in one go, thus solving the problems of low efficiency and power imbalance at both ends in traditional single-end sequential coupling.

[0131] In practical implementation, the complete process of the multi-level iterative 9-point scanning algorithm is as follows: 1. Construct a 3×3 two-dimensional grid centered on the current lens coordinates, and simultaneously traverse all 9 points within the grid using a six-axis displacement stage; 2. Simultaneously acquire Pleft and Pright for each point, calculate Pavg=(Pleft+Pright) / 2, filter points that satisfy the constraint |Pleft-Pright|<3 and record the mean; 3. Extract the coordinates corresponding to the maximum Pavg value within the grid as the new center, reduce the scanning step size to construct a new 3×3 grid for iterative scanning; 4. Iterate for a maximum of 7 rounds. When the scanning step size is less than 10nm, it is determined that the global optimal coupling point has been reached, and the left and right lens coordinates are locked to stop scanning; During the scanning process, the software uses a data fitting algorithm to eliminate instantaneous fluctuations in optical power and shorten the waiting time for point stabilization; The multi-axis strain sensing system continuously monitors the force on the fixture throughout the coupling process, and immediately stops the system in case of overload.

[0132] It is important to note that the TEC cooling current and bias current parameters should not be modified during the iteration process to avoid changes in the optical power reference. After the optimal position is locked, the left and right displacement stages should keep their coordinates fixed and should not be allowed to shift independently.

[0133] This step enables the simultaneous and optimal coupling of the optical paths of both lenses, significantly improving coupling efficiency compared to single-end sequential coupling, balancing the output optical power of the left and right dual channels, and enhancing the optical consistency of the product.

[0134] It is understandable that, apart from multi-level 9-point scanning, the coupled optimization algorithm can be replaced by genetic algorithms and particle swarm optimization algorithms to achieve global optical path optimization.

[0135] S7: TEC Reverse Heating Soldering: When the device bias current source is turned off, the TEC temperature control current source is reverse-energized to heat the TEC. The solder in the preset position inside the tube is heated and melted. The infrared thermal imaging camera collects the welding temperature in real time and feeds it back to the main control computer to achieve closed-loop temperature control.

[0136] The purpose of this step is to cut off the drive current of the optical chip, switch the TEC to reverse heating mode, and melt the solder with a uniform surface heat source. In addition, the temperature field is collected in real time by infrared thermal imaging, and the heating power and heating time are dynamically adjusted in a closed loop to stabilize the welding temperature within the preset range, so as to avoid overheating and damage to the internal adhesive layer of the device.

[0137] In practice, the main control computer first issues a command to shut down the device bias current source, cutting off the power supply to the COS device; then it switches the output current direction of the TEC temperature control current source, turning the original cooling surface into a heating surface, uniformly radiating heat to melt the solder inside the tube shell; the infrared thermal imaging camera continuously collects the two-dimensional temperature matrix of the welding area, and an independent thread extracts the highest temperature value of the matrix in real time; the main control computer performs closed-loop control based on the peak temperature: if the temperature is higher than the upper limit, the TEC output power is reduced and the heating time is shortened; if the temperature is lower than the lower limit, the output power is increased and the heating time is extended, stably maintaining a welding temperature range of 120~180℃; the strain sensing system provides continuous protection throughout the process, and the lens displacement stage remains locked at the coordinates.

[0138] It is important to note that the bias current must not be restarted during the soldering stage, as high-temperature charging will cause permanent damage to the optical chip; when the infrared temperature measurement peak exceeds 180°C, the software will automatically cut off the TEC heating current and trigger the high-temperature protection.

[0139] Through this step, the TEC uniform surface heat source achieves low thermal stress welding, and the infrared closed-loop temperature control precisely manages the welding temperature, eliminating problems such as local high temperature and adhesive layer aging and failure.

[0140] It is understandable that, in addition to TEC reverse heating, welding heat sources can be paired with auxiliary low-temperature hot air heat sources to adapt to high-temperature solders with higher melting points.

[0141] S8: Post-weld processing: After welding is completed, the TEC temperature control current source stops supplying power to the TEC and waits for the solder to cool and solidify; the automatic smoothing process of molten solder can be performed simultaneously.

[0142] The purpose of this step is to stop TEC heating, allow the molten solder to cool naturally and solidify, and drive the double-sided lenses to move back and forth to smooth the liquid solder, optimize the uniformity of the solder joints, and improve the weld strength between the lenses and the casing.

[0143] In practice, once the solder has completely melted and the preset welding time has been reached, the main control computer cuts off the TEC temperature control current source output and stops heating; it then issues motion commands, and the left and right six-axis displacement stages drive the lens to make small reciprocating translational movements, dragging the molten solder evenly spread over the welding area; after the smoothing action is completed, all displacement stages lock their coordinates to keep the lens position still, waiting for the solder to cool and solidify naturally; the cooling time is customized by the product formula, typically 30~60 seconds; the temperature drop curve is monitored by an infrared camera throughout the cooling process, and solidification is considered complete when the temperature drops below 50℃.

[0144] It is important to note that the lens should not be moved before the solder has completely solidified, as this will cause the solder joint to shift and the coupled optical path to become inaccurate; the back-and-forth movement should not be too large to avoid the lens from leaving the solder area.

[0145] This step ensures that the lens and the housing are firmly bonded after cooling and solidification. By automatically smoothing the molten solder, the weld joints are made uniform and dense, improving the reliability of the welding.

[0146] It is understandable that, in addition to the back-and-forth dragging of the lens, a micro ultrasonic vibration module can be integrated to assist in the uniform spreading of the solder.

[0147] S9: Finished Product Inspection: The device bias current source is powered on again. The left and right optical power detection units read the current optical power at both ends, compare the difference in optical power before and after welding, and output the detection results.

[0148] The purpose of this step is to re-detect the dual-end optical power after welding and solidification, compare it with the reference value collected by S5 before welding, determine whether the optical path coupling is inaccurate, whether the device has failed to weld, and automatically distinguish between good and bad products.

[0149] In practice, after the solder cools and solidifies, the main control computer restarts the device bias current source, and the pulsed output drives the photochip to emit light; the left and right optical power detection units synchronously collect the P left and P right values ​​after welding, and the software automatically calculates the power loss difference with the reference before welding; compares it with the preset loss threshold of the formula: if the difference is less than the threshold, it is judged as a good product, and if the difference exceeds the limit, it is judged as a defective product; the test results, power data before and after, temperature throughout the process, and strain curve are bound to the product serial number, stored locally, and uploaded to the cloud; after the test is completed, the command is issued to release the COS pneumatic clamp, the six-axis displacement stage lifts the COS device, and all displacement stages automatically return to zero, waiting for the production of the next material.

[0150] It should be noted that the optical power acquisition for finished product testing must wait until the temperature has completely cooled to room temperature, as high temperatures will cause deviations in the optical power values; defective product data should be marked and stored separately to support subsequent batch traceability analysis of the causes of defects.

[0151] This step automates the optical performance testing after welding, eliminating the need for additional manual inspection, automatically distinguishing between good and defective products, and enabling full-process traceability of production data.

[0152] It is understandable that, in addition to optical power testing, finished product testing can automatically call upon the optional spectrometer to test the output spectral performance of the devices, thus expanding the testing dimensions.

[0153] It is understandable that if a multi-axis strain sensing system is installed on the COS fixture, then a strain sensing protection step is also included: the multi-axis strain sensing system monitors the stress state of the COS fixture in real time throughout the entire process of material handling, clamping, coupling and welding. When the instantaneous stress exceeds the preset protection threshold, the main control computer controls all displacement stages to immediately perform emergency braking.

[0154] The purpose of this step is to continuously monitor the micro-strain of the COS fixture throughout the entire process of material handling, clamping, coupling, welding, and cooling. In the event of instantaneous overload, it will immediately trigger an emergency stop of the entire equipment displacement stage, providing all-round protection for the chip, fixture, and optical path platform.

[0155] In practical implementation, the multi-axis strain sensing system runs continuously in an independent background thread without occupying the computing power of the main automation thread; it collects triaxial micro-strain values ​​every millisecond and compares them in real time with the preset protection threshold of the formula (default ±5με); when the instantaneous strain exceeds the threshold, the underlying motion drive library directly issues an emergency stop command, and the left / middle / right three groups of six-axis displacement stage motors are locked synchronously; the software pop-up displays the location and value of the strain over-limit fault, suspends all automated processes, and after manually checking for collision and clamping overload problems, the equipment can be manually reset before production can be restarted; the fault strain data is synchronously recorded to the product production log.

[0156] It should be noted that strain protection is uninterrupted; even if the equipment is in the heating and welding stage, triggering an overload will immediately lock all moving axes. Zero-point drift can cause false triggering, so strain zero-point calibration needs to be performed daily.

[0157] This step provides uninterrupted hardware collision protection throughout the entire process, significantly reducing the scrap rate of chip breakage, fixture deformation, and optical path misalignment, and ensuring compatibility with COS materials with different processing tolerances.

[0158] It is understandable that, in addition to independent thread monitoring, strain sensor protection logic can integrate hardware circuit-level emergency stop triggering to further shorten braking response time.

[0159] In summary, this application utilizes a dual-end synchronous automatic coupling welding device for SOA butterfly devices. During the coupling stage, the optimal alignment of both lenses can be achieved in one operation by controlling the synchronous linkage of the left and right six-axis displacement stages, eliminating the need to change, rotate, or flip the fixtures. This significantly improves coupling efficiency compared to traditional single-end sequential coupling. During the welding stage, reverse-current heating via the TEC (Dielectric Temperature Coefficient) converts the TEC into a uniform surface heating source, replacing the localized heat sources of traditional laser welding and hot air welding. This results in a smaller heat-affected zone and lower welding thermal stress, effectively protecting the optical chip and internal adhesive layer of the COS (Coaxial Optical System).

[0160] In addition, the infrared thermal imaging camera can collect the temperature distribution of the welding area in real time, so that the main control computer can adjust the TEC heating power and duration in a closed loop according to the temperature data to prevent the internal adhesive layer of the COS device from overheating and failing.

[0161] The entire process can be fully automated through software, enabling automatic execution of all operations including material handling, placement, coupling, welding, and testing, making it suitable for mass production in industrial settings.

[0162] It is understood that the same or similar parts in the above embodiments can be referred to each other, and the contents not described in detail in some embodiments can be referred to the same or similar contents in other embodiments.

[0163] It should be noted that in the description of this application, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "a plurality of" means at least two.

[0164] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0165] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0166] Those skilled in the art will understand that all or part of the steps of the methods implementing the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0167] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium. The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc.

[0168] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0169] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A dual-end synchronous automatic coupling welding device for SOA butterfly devices, characterized in that, include: A central housing clamping platform is used to fix a housing pre-installed with a TEC. The central housing clamping platform integrates a power supply clamp for supplying power to the TEC inside the housing and the COS device to be placed by contacting the housing pins. A six-axis displacement stage, equipped with a COS fixture, is used to clamp COS devices from the material pick-up position and move them to the welding station inside the tube shell, and place them on the TEC. The left and right six-axis displacement stages are respectively arranged on both sides of the middle six-axis displacement stage, and are used to clamp and move the left and right lenses respectively to complete the synchronous alignment of the double-ended optical paths. A device bias current source is electrically connected to the power supply fixture to provide bias current to the COS device, so that the optical chip of the COS device emits light for coupling alignment; The TEC temperature control current source is electrically connected to the power supply fixture and is used to control the working state of the TEC: in the coupling stage, forward power is applied for cooling to maintain a constant temperature of the optical chip; in the welding stage, reverse power is applied for heating to melt the solder in a preset position inside the tube shell. The integrated vision and infrared temperature measurement sensing system includes an industrial camera and an infrared thermal imaging camera, which are used to guide alignment and monitor welding temperature, respectively. The left and right optical power detection units are respectively located at both ends of the optical path to detect the dual-end output optical power in real time and provide feedback for coupling alignment. The main control computer communicates with the above modules and is used to control the modules to work together to complete the entire process of material picking, placement, coupling alignment, welding and testing according to a preset timing sequence.

2. The device according to claim 1, characterized in that, During the coupling phase, with the goal of maximizing the average optical power of the left and right dual channels, the left six-axis displacement stage and the right six-axis displacement stage are synchronously linked for scanning to achieve synchronous optimal alignment of the dual lenses and the optical paths at both ends of the optical chip.

3. The device according to claim 1, characterized in that, The infrared thermal imaging camera collects the temperature distribution of the welding area in real time and feeds it back to the main control computer. The main control computer adjusts the reverse power and duration of the TEC temperature control current source in a closed loop according to the temperature distribution to maintain the welding temperature within a preset range.

4. The device according to claim 1, characterized in that, The power supply fixture includes a power-on probe. When the six-axis displacement stage places the COS device on the TEC, the power-on probe is connected to the electrodes of the COS device, and the device bias current source can provide bias current to the COS device through the power-on probe.

5. The device according to claim 1, characterized in that, It also includes a multi-axis strain sensing system, which is installed on the COS fixture to detect the stress state of the COS fixture in real time and trigger emergency braking when the detected stress exceeds a preset threshold.

6. A method for synchronous automatic coupling welding of SOA butterfly devices at both ends, characterized in that, Performed using the apparatus according to any one of claims 1 to 5, the procedure includes the following steps: S1: System initialization: All displacement stages return to zero, and all detection units start and complete parameter configuration; S2: Automatic material finding: The industrial camera positions the COS device picking position, and the six-axis displacement stage moves to the picking position; S3: Automatic clamping: The COS fixture clamps the COS device; S4: Automatic placement: The six-axis displacement stage moves the COS device to the welding station inside the tube shell and places it on the TEC, whereby the COS device contacts the solder at a preset position inside the tube shell; S5: Automatic power-on: The bias current source of the device applies a bias current to the COS device to make the optical chip emit light. The left optical power detection unit and the right optical power detection unit read the initial optical power at the left and right ends respectively. The TEC temperature control current source is powered on in the forward direction to cool and maintain the optical chip temperature constant. S6: Dual-end synchronous coupling: The left six-axis displacement stage and the right six-axis displacement stage scan synchronously and in conjunction, aiming to maximize the average optical power of the left and right dual channels, and lock the optimal coupling position of the left and right lenses. S7: TEC reverse heating welding: The bias current source of the device is turned off, and the temperature control current source of the TEC is reversed to heat the TEC. The solder in the preset position inside the tube is heated and melted. The infrared thermal imaging camera collects the welding temperature in real time and feeds it back to the main control computer to realize closed-loop temperature control. S8: Post-welding treatment: After welding is completed, the TEC temperature-controlled current source stops supplying power to the TEC and waits for the solder to cool and solidify; S9: Finished Product Inspection: The bias current source of the device is re-powered, and the left optical power detection unit and the right optical power detection unit read the current optical power at both ends, compare the difference in optical power before and after welding, and output the detection result.

7. The method according to claim 6, characterized in that, In step S6, the dual-end synchronous coupling is implemented using a multi-level iterative 9-point scanning algorithm, specifically including: A 3×3 two-dimensional grid is constructed with the current coupling position as the center. Each point in the grid is traversed and the corresponding left and right dual-channel optical power values ​​are recorded. The scanning range is gradually reduced with the average dual-channel optical power as the criterion, and the global optimal coupling point is iteratively approached.

8. The method according to claim 6, characterized in that, The closed-loop temperature control in step S7 specifically includes: The infrared thermal imaging camera collects a two-dimensional temperature matrix of the welding area in real time. The main control computer adjusts the reverse power and duration of the TEC temperature control current source in a closed loop according to the highest temperature value in the two-dimensional temperature matrix, so that the welding temperature is maintained within a preset range.

9. The method according to claim 6, characterized in that, It also includes strain sensing protection steps: The multi-axis strain sensing system monitors the stress state of the COS fixture in real time throughout the entire process of material handling, clamping, coupling, and welding. When the instantaneous stress exceeds the preset protection threshold, the main control computer controls all displacement stages to immediately perform emergency braking.

10. The method according to claim 6, characterized in that, The post-welding processing in step S8 also includes: after the solder melts, the left six-axis displacement stage and the right six-axis displacement stage drive the left lens and the right lens to reciprocate and smooth the molten solder.

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