Diode full-automatic test system and performance test method

Abstract

The invention relates to the technical field of electronic components, in particular to a diode full-automatic test system and a performance test method, and the system comprises a test management server, a programmable test resource array, a feeding and discharging and positioning module and a test station. The test management server is a central processing unit, carries test management software and is responsible for formulating a test process, scheduling and distributing test tasks, centrally storing and managing test data and generating a test report; the programmable test resource array is in communication connection with the test management server, and the programmable test resource array comprises a programmable direct current power supply, a programmable electronic load, a high-precision digital multimeter, a programmable function generator and a multiplexing switch matrix. According to the invention, qualitative leap of efficiency, precision and reliability is realized in production inspection, quality evaluation and sorting links of diodes.

Description

Technical Field

[0001] This invention relates to the field of electronic components technology, and in particular to a fully automated diode testing system and performance testing method. Background Technology

[0002] In the large-scale production and quality inspection of semiconductor devices such as diodes, rapid and accurate testing of their key electrical parameters is a core step in ensuring product quality and reliability. Traditional testing methods mainly rely on semi-automatic or manual operation modes, where operators manually place the diodes under test one by one onto a dedicated test fixture, measure individual parameters using independent benchtop instruments, and manually record the data and compare it with the specifications to determine the results.

[0003] Traditional testing methods have limitations. First, the manual operation involves numerous steps and is slow-paced, resulting in low testing efficiency and failing to meet the high-throughput testing requirements of modern production lines, thus becoming a bottleneck for capacity improvement. Second, the testing process heavily relies on the operator's skill and responsibility. Different personnel, or even the same personnel operating under fatigue, are highly susceptible to human errors such as clamping and positioning errors, incorrect instrument settings, data misreading, or omissions, leading to inconsistent and unreliable test results and posing potential risks to product quality control. Third, when product models change or testing standards are updated, multiple instruments need to be reconfigured and testing procedures adjusted, resulting in long debugging cycles, insufficient flexibility, and low equipment reuse rates. Furthermore, test data is scattered across different instruments or paper records, lacking unified and structured management, making effective data traceability, statistical analysis, and in-depth data mining difficult, and failing to provide strong data support for process improvement and quality analysis. Summary of the Invention

[0004] To address the aforementioned issues, this invention completely transforms the traditional semi-automatic testing mode that relies on manual labor. Through a fully automated, programmable, and data-driven system design, it achieves a qualitative leap in efficiency, accuracy, and reliability in the diode production inspection, quality assessment, and sorting processes, resulting in a fully automated diode testing system and performance testing method.

[0005] The technical solution adopted in this invention is: a fully automated diode testing system, which is a software-controlled testing platform, including a test management server, a programmable test resource array, a loading / unloading and positioning module, and test stations; the test management server is a central processing unit, equipped with test management software, responsible for the formulation of test procedures, scheduling and distribution of test tasks, centralized storage and management of test data, and generation of test reports; the programmable test resource array is communicatively connected to the test management server, and the programmable test resource array includes a programmable DC power supply, a programmable electronic load, a high-precision digital multimeter, a programmable function generator, and a multiplexed switch matrix; the test management server... The programmable test resource array is configured with operating parameters by sending control commands through a standard communication interface. The loading, unloading, and positioning module includes a multi-degree-of-freedom robotic arm, a vision positioning system, and a tray support platform. The end of the multi-degree-of-freedom robotic arm is equipped with a vacuum nozzle or gripper for picking up diodes under test from the tray. The vision positioning system is used to identify the position and polarity of the diodes in the tray and feeds the coordinate information back to the test management server, which then controls the multi-degree-of-freedom robotic arm to pick up and place the diodes at the test station. The test station is equipped with test fixtures that match the diode pins, and the test fixtures are electrically connected to the programmable test resource array through the multiplexer matrix. The test management software includes a test process editor, a test sequence execution engine, and a data analysis engine. Users can customize test items, test conditions, judgment criteria, and test processes through a graphical interface, and automatically complete the installation, removal, testing, data recording, and result judgment of diodes according to the preset process.

[0006] A further improvement to the above solution is that the test management software of the test management server includes a user management module, a model library module, and a data dashboard module. The user management module is used to manage user accounts with different permissions; the model library module is used to store the specification parameters of different diode models and the corresponding standard test process templates; and the data dashboard module displays test progress, yield statistics, and equipment status information in real time in the form of charts.

[0007] A further improvement to the above scheme is that, in the programmable test resource array, the multiplexed switch matrix adopts a low thermal electromotive force relay matrix, which supports parallel or fast switching tests of at least 32 test channels; the high-precision digital multimeter has a resolution of not less than 6½ digits, and is used to accurately measure microampere-level and millivolt-level signals such as the forward voltage drop and reverse leakage current of diodes.

[0008] A further improvement to the above solution is that the visual positioning system of the automatic loading, unloading and positioning module includes a high-resolution CCD camera and an image processing unit, which can identify the package shape and polarity markings of the diodes and correct positioning errors caused by tray placement deviations.

[0009] A further improvement to the above solution is that the precision test fixture at the test station adopts a four-wire Kelvin connection method and has a self-cleaning probe to eliminate the influence of contact resistance on measurement accuracy; the test fixture also integrates a temperature sensor to monitor the ambient temperature during the test process.

[0010] A further improvement to the above scheme is that it also includes an environmental temperature chamber, and the test station is located inside the environmental temperature chamber; the test management server can control the temperature of the environmental temperature chamber to change according to a preset curve within the range of -40°C to 150°C in order to perform temperature characteristic tests on the diode.

[0011] A further improvement to the above solution is that the test process editor of the test management software supports drag-and-drop programming, allowing users to combine basic test commands to construct complex test sequences, including: Forward characteristic test: Scan the forward current and measure the corresponding forward voltage drop; Reverse characteristic test: Apply reverse voltage and measure reverse leakage current; Dynamic characteristic testing: applying a fast pulse using a function generator to measure reverse recovery time and softness factor; and surge current testing; The data analysis engine can process the collected raw test data in real time, automatically calculate key parameters, and compare them with the specification limits retrieved from the model library to determine whether the diode is qualified or not; for unqualified products, it can also automatically record failure parameters and failure modes.

[0012] A test method based on a fully automated diode test system includes the following steps: Step S1: The system powers on and performs a self-test. The test management server initializes each hardware module. The operator selects the model of the diode to be tested or imports a custom test process in the software interface and places the tray full of diodes to be tested on the tray support platform. Step S2, for each diode in the tray, the system performs the following sub-steps: Step S2.1, Visual Positioning and Grasping: The visual positioning system identifies the position and polarity of the diode, guiding the robotic arm to accurately grasp the diode; Step S2.2: The robotic arm places the diode in the precision test fixture at the test station and ensures a good electrical connection. Step S2.3: The test management server automatically applies a series of electrical stresses and simultaneously measures electrical parameters by controlling the programmable test resource array according to the preset test process. Step S2.4: The system collects measurement data, the data analysis engine processes the data in real time and compares it with the specification limits to determine whether the diode is qualified; Step S2.5: Based on the judgment result, the robotic arm places the diode into the corresponding qualified or unqualified product tray; Step S3: After a single batch of tests is completed, the test management server automatically generates a comprehensive test report that includes a test summary, statistical process control charts, a detailed list of test data, and non-conforming product analysis, and stores all the data in the database.

[0013] A further improvement to the above scheme is that, in step S2.4, at least one set of the following tests is performed: Forward voltage drop test: Control the programmable DC power supply to output one or more specified constant forward currents, and measure the forward voltage drop across the diode using a digital multimeter; Reverse leakage current test: Control the programmable DC power supply to output a specified reverse voltage, and measure the reverse current flowing through the diode using a digital multimeter; Reverse recovery time test: Control the programmable function generator to generate a rapidly switching square wave signal, causing the diode to switch from forward bias to reverse bias instantaneously. Use a digital multimeter or high-speed acquisition card to capture the current waveform, and use software algorithms to calculate the time required from the current zero crossing point to the reverse current decaying to the specified value, i.e., the reverse recovery time.

[0014] A further improvement to the above scheme is that, in step S2.4, for diodes that are determined to be unqualified, the system will record the specific test items, measured values, and degree of deviation from specifications for their failure; when generating a test report, the system will automatically classify and statistically analyze the unqualified products and identify the main failure modes.

[0015] A further improvement to the above scheme is that, in the reverse recovery time test, the software algorithm further calculates the softness factor, which is defined as the ratio of the time required for the current to decay from the peak value to 10% of its value to the time required for the current to decay from the peak value to 90% of its value in the reverse recovery current waveform, i.e., S=tb / ta.

[0016] The beneficial effects of this invention are: Compared to existing diode testing methods, this invention combines a highly integrated hardware architecture with intelligent software control to achieve full automation, intelligence, and high precision in the diode testing process, improving testing efficiency, consistency, and reliability. On one hand, this invention achieves a high degree of automation and unmanned operation of the testing process. Integrating loading, unloading, and positioning modules, through the collaborative work of a multi-degree-of-freedom robotic arm and a high-precision vision positioning system, it can automatically complete all physical operations of picking up the diode under test from the tray, accurately positioning it, placing it at the testing station, and returning it to its original position after testing. This completely replaces the traditional manual loading, unloading, and alignment steps, significantly reducing labor costs and operational intensity, and effectively avoiding errors and inconsistencies that may be introduced by human intervention. On the other hand, the programmable test resource array integrates key instruments such as power supplies, loads, multimeters, and signal generators, and achieves flexible resource allocation through a switch matrix. Most importantly, the accompanying test management software provides a graphical test process editor, allowing users to intuitively customize various test items (such as forward voltage drop Vf, reverse breakdown voltage Vbr, reverse leakage current Ir, etc.), set precise test conditions (such as current, voltage, and temperature), configure judgment criteria, and arrange complex test sequences without writing complex code. This hardware and software integration design enables a single system to quickly adapt to diode products of different specifications and test requirements, greatly enhancing the versatility and reusability of the equipment and shortening production line debugging time caused by product changeovers. This invention employs high-precision testing instruments to ensure the accuracy of electrical parameter measurements. All test commands are issued uniformly by the server, and test data is collected in real time and centrally stored in the database, effectively eliminating errors that may occur with manual recording. The data analysis engine can automatically judge results according to preset standards and generate structured test reports, providing complete and reliable data support for quality control and product traceability in the production process. This invention completely changes the traditional semi-automatic testing mode that relies on manual labor. Through a fully automatic, programmable, and data-driven system design, it achieves a qualitative leap in efficiency, accuracy, and reliability in the production inspection, quality assessment, and sorting of diodes.

[0017] The testing method based on the fully automated diode testing system, through its streamlined and intelligent step design, seamlessly integrates hardware control, test execution, and data analysis, achieving a fundamental transformation in diode testing from single-point operation to full-process automation. This demonstrates significant technological advancement and practical value. From system power-on self-test and model selection to visual positioning and grasping, automatic testing, real-time judgment, and final sorting and classification, a complete closed-loop operation process is formed, requiring no manual intervention. In particular, the loop consisting of steps S2.1 to S2.5 achieves fully automated "grabbing-testing-judgment-sorting" of each diode in the tray, completely replacing the traditional manual loading and unloading, manual connection testing, data recording, and classification, greatly improving testing efficiency and reducing labor intensity and the risk of human error. Through unified scheduling by the test management server, the system strictly follows the preset and customizable test process (step S2.3), ensuring that the applied electrical stress conditions and measurement timing are completely consistent for each diode, effectively eliminating fluctuations in test results caused by differences in human operation rhythm and techniques. The real-time data processing and automatic judgment in step S2.4 avoids subjective misjudgments and ensures the strict implementation of quality judgment standards, making the test data highly comparable and reliable. In step S3, not only is basic sorting completed, but a comprehensive test report is also automatically generated and archived. This report integrates a test summary, Statistical Process Control (SPC) charts, and detailed data lists, providing strong data support for production process optimization and quality trend analysis. All test data is systematically recorded, enabling full-process traceability of product quality, facilitating rapid location of problematic batches, and failure mode analysis, thereby significantly improving production quality control capabilities. This invention, through the above systematic methodological steps, deeply integrates automation technology, precision measurement, and information management, not only significantly improving the efficiency and accuracy of diode testing, but more importantly, constructing a data-driven, closed-loop management intelligent testing system, providing an effective solution for the high-quality development and intelligent upgrading of the electronic component manufacturing industry. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the connection structure of the fully automated diode testing system of the present invention; Figure 2 for Figure 1 A schematic diagram of the loading, unloading, and positioning module of a fully automated diode testing system; Figure 3 This is a flowchart illustrating the testing method of the fully automated diode testing system of the present invention.

[0019] Figure labeling: 1. Test Management Server; 11. Test Management Software; 111. Test Process Editor; 112. Test Sequence Execution Engine; 113. Data Analysis Engine; 114. User Management Module; 115. Model Library Module; 116. Data Dashboard Module; 2. Programmable Test Resource Array; 21. Programmable DC Power Supply; 22. Programmable Electronic Load; 23. High-Precision Digital Multimeter; 24. Programmable Function Generator; 25. Multiplexer Switch Matrix; 36. Loading / Unloading and Positioning Module; 31. Multi-DOF Robotic Arm; 32. Vision Positioning System; 32. CCD Camera; 321. Image Processing Unit; 322. Material Tray Support Platform; 33. Test Station; 4. Test Fixture; 41. Environmental Temperature Chamber; 5. Detailed Implementation

[0020] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Preferred embodiments of the invention are shown in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided to provide a thorough and complete understanding of the disclosure of the invention.

[0021] It should be noted that when a component is said to be "fixed to" another component, it can be directly attached to the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component.

[0022] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Figures 1-2As shown, in one embodiment of the present invention, a fully automated diode testing system is disclosed. This system is a software-controlled testing platform, comprising a test management server 1, a programmable test resource array 2, a loading / unloading and positioning module 3, and a test station 4. The test management server 1 is a central processing unit, equipped with test management software 11, responsible for defining test procedures, scheduling and distributing test tasks, centrally storing and managing test data, and generating test reports. The programmable test resource array 2 is communicatively connected to the test management server 1. The programmable test resource array 2 includes a programmable DC power supply 21, a programmable electronic load 22, a high-precision digital multimeter 23, a programmable function generator 24, and a multiplexed switch matrix 25. The test management server 1... The programmable test resource array 2 is configured with control commands sent through a standard communication interface. The loading, unloading, and positioning module 3 includes a multi-degree-of-freedom robotic arm 31, a vision positioning system 32, and a tray support platform 33. The end of the multi-degree-of-freedom robotic arm 31 is equipped with a vacuum nozzle or gripper for picking up diodes to be tested from the tray. The vision positioning system 32 is used to identify the position and polarity of the diodes in the tray and feeds back the coordinate information to the test management server 1. The test management server 1 controls the multi-degree-of-freedom robotic arm 31 to pick up and place the diodes to the test station 4. The test station 4 is equipped with a test fixture 41 that matches the diode pins. The test fixture 41 is electrically connected to the programmable test resource array 2 through the multiplexer switch matrix 25. The test management software 11 includes a test process editor 111, a test sequence execution engine 112, and a data analysis engine 113. Users can customize test items, test conditions, judgment criteria, and test processes through a graphical interface, and automatically complete the installation, removal, testing, data recording, and result judgment of diodes according to the preset process.

[0023] This embodiment combines a highly integrated hardware architecture with intelligent software control to achieve automation, intelligence, and high precision throughout the entire diode testing process, improving testing efficiency, consistency, and reliability. On one hand, this invention achieves a high degree of automation and unmanned operation of the testing process. Integrating a loading / unloading and positioning module 3, through the collaborative work of a multi-degree-of-freedom robotic arm 31 and a high-precision vision positioning system 32, it can automatically complete all physical operations of picking up the diode under test from the tray, accurately positioning it, placing it at the testing station 4, and returning it to its original position after testing. This completely replaces the traditional manual loading / unloading and alignment steps, significantly reducing labor costs and operational intensity, and effectively avoiding errors and inconsistencies that may be introduced by human intervention. On the other hand, the programmable test resource array 2 integrates key instruments such as power supplies, loads, multimeters, and signal generators, and achieves flexible resource allocation through a switch matrix. Most importantly, the accompanying test management software 11 provides a graphical test process editor 111, allowing users to intuitively customize various test items (such as forward voltage drop Vf, reverse breakdown voltage Vbr, reverse leakage current Ir, etc.), set precise test conditions (such as current, voltage, and temperature), configure judgment criteria, and arrange complex test sequences without writing complex code. This hardware and software integration design enables a single system to quickly adapt to diode products of different specifications and test requirements, greatly enhancing the versatility and reusability of the equipment and shortening production line debugging time caused by product changeovers. This embodiment uses high-precision testing instruments to ensure the accuracy of electrical parameter measurements. All test commands are issued uniformly by the server, and test data is collected in real time and centrally stored in the database, effectively eliminating errors that may occur from manual recording. The data analysis engine 113 can automatically judge the results according to preset standards and generate structured test reports, providing complete and reliable data support for quality control and product traceability in the production process. This embodiment completely changes the traditional semi-automatic testing mode that relies on manual labor. Through a fully automatic, programmable, and data-driven system design, it achieves a qualitative leap in efficiency, accuracy, and reliability in the diode production inspection, quality assessment, and sorting processes.

[0024] The test management software 11 of the test management server 1 includes a user management module 114, a model library module 115, and a data dashboard module 116. The user management module 114 manages user accounts with different permissions; the model library module 115 stores the specification parameters of different diode models and corresponding standard test procedure templates; and the data dashboard module 116 displays test progress, yield statistics, and equipment status information in real-time in chart form. In this embodiment, the user management module 114, model library module 115, and data dashboard module 116 integrated in the test management software 11 work collaboratively, significantly improving the system's usability, standardization level, and real-time monitoring capabilities. The user management module 114, through hierarchical permission settings, ensures the security and standardization of test procedures and data, preventing unauthorized operations. The model library module 115 stores the specification parameters of different diodes and standard test procedure templates, which operators can access with a single click, greatly simplifying test preparation and model changeover processes, avoiding errors from manual parameter input, and ensuring the consistency of test conditions. The data dashboard module 116 dynamically presents test progress, real-time yield, and equipment status with visual charts, providing on-site administrators with an intuitive understanding of the production situation, facilitating the rapid detection of anomalies, optimization of production scheduling, and decision-making.

[0025] In the programmable test resource array 2, the multiplexer switch matrix 25 employs a low-thermal-electromotive force (TEMF) relay matrix, supporting parallel or rapid switching tests of at least 32 test channels. The high-precision digital multimeter 23, with a resolution of at least 6.5 digits, is used to accurately measure microampere-level and millivolt-level signals such as the forward voltage drop and reverse leakage current of diodes. In this embodiment, the programmable test resource array 2, by using a low-thermal-electromotive force (TEMF) relay matrix as the core of the multiplexer and equipped with a high-precision digital multimeter 23 with a resolution of at least 6.5 digits, jointly ensures the system's excellent measurement accuracy and stability under high-speed, multi-channel testing. The low-thermal-electromotive force relay effectively eliminates parasitic thermoelectric potential caused by contact temperature differences, which is crucial for measuring weak millivolt-level signals such as the forward voltage drop of diodes. It avoids measurement errors introduced by channel switching and ensures the accuracy and comparability of data even in 32-channel parallel or rapid switching test modes. Simultaneously, the high-resolution digital multimeter can accurately capture minute parameter changes such as microampere-level reverse leakage current, providing reliable ultra-fine measurement capabilities for determining diode quality.

[0026] The vision positioning system 32 of the automatic loading / unloading and positioning module 3 includes a high-resolution CCD camera 321 and an image processing unit 322. It can identify the diode's package shape and polarity markings, and correct positioning errors caused by tray placement deviations. Specifically, the precision test fixture 41 of the test station 4 uses a four-wire Kelvin connection method and has self-cleaning probes to eliminate the influence of contact resistance on measurement accuracy. The test fixture 41 also integrates a temperature sensor to monitor the ambient temperature during the testing process. In this embodiment, the collaborative design of the automatic loading / unloading and positioning module 3 and the precision test fixture 41 provides key technical support for solving the two core challenges of positioning accuracy and contact reliability in automated testing. Specifically, the vision positioning system 32, through the high-resolution CCD camera 321 and the image processing unit 322, can not only accurately identify the diode's package shape and polarity to ensure correct gripping by the robotic arm, but also correct mechanical deviations caused by tray placement in real time, achieving sub-millimeter level precision positioning and fundamentally avoiding gripping failures or device damage caused by inaccurate positioning. More importantly, the precision test fixture 41 used in test station 4 integrates several innovative designs: its four-wire (Kelvin) connection method can separate the current application and voltage measurement paths, effectively eliminating the influence of lead and contact resistance on weak signal measurement; the self-cleaning probe ensures low-resistance and stable contact between the probe and diode pin during each test, avoiding measurement errors introduced by oxide layers or contaminants; the integrated temperature sensor enables real-time monitoring of the test environment temperature, providing temperature compensation for measurement data and ensuring the accuracy and comparability of test results under different environments.

[0027] The system also includes an ambient temperature chamber 5, within which the test station 4 is located. The test management server 1 can control the temperature of the ambient temperature chamber 5 to vary according to a preset curve within the range of -40°C to 150°C to perform temperature characteristic tests on the diode. In this embodiment, integrating the ambient temperature chamber 5 and controlling it under the control of the test management server 1 greatly expands the system's testing capabilities and application scope, enabling accurate evaluation of the diode's performance under all operating conditions. By placing the test station 4 inside the chamber and having the server precisely control the temperature to vary according to a preset curve within a wide range of -40°C to 150°C, the system can automatically perform high and low temperature shock, temperature cycling, and steady-state temperature point tests. This effectively simulates the extreme temperature environment faced by diodes in practical applications, making it possible to systematically and repeatably measure the temperature characteristics and temperature coefficients of key parameters such as reverse leakage current (Ir) and forward voltage drop (Vf).

[0028] The test process editor of the test management software 111 supports drag-and-drop programming, allowing users to combine basic test commands to build complex test sequences, including: Forward characteristic test: Scan the forward current and measure the corresponding forward voltage drop; Reverse characteristic test: Apply reverse voltage and measure reverse leakage current; Dynamic characteristic test: Apply a fast pulse using a function generator to measure reverse recovery time and softness factor; and surge current test.

[0029] In this embodiment, the test process editor 111 integrated into the test management software 11, which supports drag-and-drop programming, greatly improves the flexibility, efficiency, and reusability of system test process construction, effectively reducing the technical threshold for automated testing. Users do not need professional programming skills; they can freely combine a series of basic test commands (such as current scanning, voltage application, pulse generation, timing measurement, etc.) through an intuitive graphical interface to quickly construct complex test sequences covering the static and dynamic characteristics of diodes. It can accurately perform forward characteristic tests to plot IV curves, reverse characteristic tests to evaluate leakage performance, and seamlessly integrate advanced projects such as dynamic characteristic tests (such as reverse recovery time and softness factor measurement) and surge current tests.

[0030] The data analysis engine 113 can process the collected raw test data in real time, automatically calculate key parameters, and compare them with the specification limits retrieved from the model library to determine whether the diode is qualified or not. For unqualified products, it can also automatically record failure parameters and failure modes. In this embodiment, the integrated high-performance data analysis engine 113 realizes intelligent and real-time test data processing and is the core link of this system to achieve high-precision, high-efficiency, and fully automatic testing. This engine can process massive amounts of raw test data in real time during the testing process, automatically and accurately calculate a series of key performance parameters such as forward voltage drop (Vf), reverse leakage current (Ir), and reverse recovery time (trr), and instantly compare them with the corresponding upper and lower limits of the specifications retrieved from the preset model library. Thus, it automatically and objectively completes the "qualified" and "unqualified" judgment, completely eliminating the lag and subjective error that may exist in traditional manual interpretation. Most importantly, for the defective products that are judged to be defective, the engine can not only automatically mark them, but also record in detail the specific parameters that caused their failure (such as Vf exceeding the tolerance, Ir being too large, etc.) and the corresponding failure modes, forming a structured data record.

[0031] See Figures 1-3 As shown, a test method based on a fully automated diode test system includes the following steps: Step S1: The system powers on and performs a self-test. The test management server 1 initializes each hardware module. The operator selects the model of the diode to be tested or imports a custom test process in the software interface and places the tray full of diodes to be tested on the tray support platform 33. Step S2, for each diode in the tray, the system performs the following sub-steps: Step S2.1, Visual positioning and grasping: The visual positioning system 32 identifies the position and polarity of the diode and guides the robotic arm to accurately grasp the diode; Step S2.2: The robotic arm places the diode in the precision test fixture 41 at the test station 4 and ensures a good electrical connection. Step S2.3: According to the preset test process, the test management server 1 automatically applies a series of electrical stresses by controlling the programmable test resource array 2 and simultaneously measures electrical parameters. Step S2.4: The system collects measurement data, and the data analysis engine 113 processes the data in real time and compares it with the specification limits to determine whether the diode is qualified. Step S2.5: Based on the judgment result, the robotic arm places the diode into the corresponding qualified or unqualified product tray; Step S3: After a single batch of tests is completed, the test management server 1 automatically generates a comprehensive test report containing a test summary, statistical process control charts, a detailed list of test data, and non-conforming product analysis, and stores all the data in the database.

[0032] This embodiment, through a streamlined and intelligent step design, seamlessly integrates hardware control, test execution, and data analysis, achieving a fundamental transformation in diode testing from single-point operation to full-process automation, demonstrating significant technological advancement and practical value. From system power-on self-test and model selection to visual positioning and grasping, automatic testing, real-time judgment, and final sorting and classification, a complete closed-loop operation process without manual intervention is formed. In particular, the loop consisting of steps S2.1 to S2.5 achieves fully automated "grabbing-testing-judgment-sorting" of each diode in the tray, completely replacing the traditional manual loading and unloading, manual connection testing, data recording, and classification, greatly improving testing efficiency and reducing labor intensity and the risk of human error. Through unified scheduling by the test management server 1, the test is executed strictly according to the preset, customizable test process (step S2.3), ensuring that the applied electrical stress conditions and measurement timing are completely consistent for each diode, effectively eliminating fluctuations in test results caused by differences in human operation rhythm and techniques. The real-time data processing and automatic judgment in step S2.4 avoids subjective misjudgments and ensures the strict implementation of quality judgment standards, making the test data highly comparable and reliable. In step S3, not only is basic sorting completed, but a comprehensive test report is also automatically generated and archived. This report integrates a test summary, Statistical Process Control (SPC) charts, and detailed data lists, providing strong data support for production process optimization and quality trend analysis. All test data is systematically recorded, enabling full-process traceability of product quality, facilitating rapid location of problematic batches, and failure mode analysis, thereby significantly improving production quality control capabilities. This invention, through the above systematic methodological steps, deeply integrates automation technology, precision measurement, and information management, not only significantly improving the efficiency and accuracy of diode testing, but more importantly, constructing a data-driven, closed-loop management intelligent testing system, providing an effective solution for the high-quality development and intelligent upgrading of the electronic component manufacturing industry.

[0033] In step S2.4, at least one set of the following tests shall be performed: Forward voltage drop test: Control the programmable DC power supply 21 to output one or more specified constant forward currents, and measure the forward voltage drop across the diode using a digital multimeter; Reverse leakage current test: Control the programmable DC power supply 21 to output a specified reverse voltage, and measure the reverse current flowing through the diode using a digital multimeter; Reverse recovery time test: The programmable function generator 24 generates a rapidly switching square wave signal, causing the diode to switch from forward bias to reverse bias instantaneously. The current waveform is captured using a digital multimeter or high-speed acquisition card, and the time required for the reverse current to decay to a specified value from the current zero crossing point is calculated by software algorithm, which is the reverse recovery time.

[0034] In this embodiment, the multi-dimensional, automated test sequence defined in step S2.4 achieves efficient and accurate integrated measurement of the diode's core performance parameters through the precise coordination of internal hardware units (such as the programmable DC power supply 21, function generator, and digital multimeter) and intelligent control of software algorithms. This step can sequentially or selectively execute forward voltage drop testing, reverse leakage current testing, and reverse recovery time testing in a coherent automated process, comprehensively covering the diode's static and key dynamic characteristics. Specifically, by precisely controlling the application of current and voltage, and combining high-precision measurement and high-speed acquisition technology, the system can not only accurately obtain the forward voltage drop (Vf) characterizing the diode's conduction performance and the reverse leakage current (Ir) characterizing its cutoff performance, but also accurately simulate switching application scenarios and automatically calculate the key dynamic parameter of reverse recovery time (trr) by analyzing transient current waveforms.

[0035] In step S2.4, for diodes that are determined to be unqualified, the system will record the specific test items, measured values ​​and the degree of deviation from specifications for their failure; when generating the test report, the system will automatically classify and statistically analyze the unqualified products and identify the main failure modes.

[0036] In the reverse recovery time test, the software algorithm further calculates the softness factor, which is defined as the ratio of the time required for the current to decay from the peak value to 10% of its value to the time required for it to decay from the peak value to 90% of its value in the reverse recovery current waveform, i.e., S=tb / ta.

[0037] In this embodiment, the intelligent data analysis and report generation function integrated in step S2.4 greatly enhances the utilization value of test results and the efficiency of quality control. For diodes determined to be unqualified, the system not only records the failure facts but also records the specific test items, measured values, and deviations from the specification limits in detail, providing accurate data traceability for subsequent root cause analysis. When generating the final test report, the system automatically performs multi-dimensional classification statistics on unqualified products and identifies the main failure modes (such as "excessive reverse leakage current" or "excessive reverse recovery time") based on the failure data, thereby quickly revealing systemic defects or weaknesses in the production process. Particularly important is that in the reverse recovery time test, the system further expands the depth of dynamic characteristic evaluation through software algorithms, automatically calculating the softness factor (S=tb / ta) characterizing the smoothness of the reverse recovery process. This parameter effectively distinguishes between "hard recovery" and "soft recovery" characteristics, which is crucial for evaluating the electromagnetic noise (EMI) performance and reliability of diodes in switching circuits.

[0038] The above embodiments merely illustrate several implementation methods of the present invention, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this patent should be determined by the appended claims.

Claims

1. A fully automated diode testing system, which is a software-controlled testing platform, characterized in that: This includes a test management server, a programmable test resource array, a loading / unloading and positioning module, and test workstations; The test management server is a central processing unit equipped with test management software, responsible for the formulation of test procedures, scheduling and distribution of test tasks, centralized storage and management of test data, and generation of test reports. The programmable test resource array is communicatively connected to the test management server. The programmable test resource array includes a programmable DC power supply, a programmable electronic load, a high-precision digital multimeter, a programmable function generator, and a multiplexer switch matrix. The test management server sends control commands to the programmable test resource array through a standard communication interface to configure its operating parameters. The loading, unloading, and positioning module includes a multi-degree-of-freedom robotic arm, a vision positioning system, and a material tray support platform; the end of the multi-degree-of-freedom robotic arm is equipped with a vacuum nozzle or gripper for picking up the diode to be tested from the material tray. The vision positioning system is used to identify the position and polarity of diodes in the tray and feeds the coordinate information back to the test management server. The test management server controls the multi-degree-of-freedom robotic arm to grasp and place the diodes to the test station. The test station is equipped with a test fixture that matches the diode pins. The test fixture is electrically connected to the programmable test resource array through the multiplexed switch matrix. The test management software includes a test process editor, a test sequence execution engine, and a data analysis engine. Users can customize test items, test conditions, judgment criteria, and test processes through a graphical interface, and automatically complete the installation, removal, testing, data recording, and result judgment of diodes according to the preset process.

2. The fully automated diode testing system according to claim 1, characterized in that: The test management software of the test management server includes a user management module, a model library module, and a data dashboard module. The user management module is used to manage user accounts with different permissions. The model library module is used to store the specification parameters of different diode models and the corresponding standard test procedure templates; the data dashboard module displays the test progress, yield statistics, and equipment status information in real time in the form of charts.

3. The fully automated diode testing system according to claim 1, characterized in that: In the programmable test resource array, the multiplexed switch matrix adopts a low thermal electromotive force relay matrix, which supports parallel or fast switching tests of at least 32 test channels; the high-precision digital multimeter has a resolution of not less than 6½ digits and is used to accurately measure microampere and millivolt level signals such as forward voltage drop and reverse leakage current of diodes.

4. The fully automated diode testing system according to claim 1, characterized in that: The automatic loading, unloading and positioning module's visual positioning system includes a high-resolution CCD camera and an image processing unit, which can identify the diode's package shape and polarity markings, and correct positioning errors caused by tray placement deviations. The precision test fixture at the test station uses a four-wire Kelvin connection and has a self-cleaning probe to eliminate the influence of contact resistance on measurement accuracy. The test fixture also integrates a temperature sensor to monitor the ambient temperature during the test.

5. The fully automated diode testing system according to claim 1, characterized in that: It also includes an ambient temperature chamber, and the test station is located inside the ambient temperature chamber; the test management server can control the temperature of the ambient temperature chamber to change according to a preset curve within the range of -40°C to 150°C in order to perform temperature characteristic tests on diodes.

6. The fully automated diode testing system according to claim 1, characterized in that: The test management software's test process editor supports drag-and-drop programming, allowing users to combine basic test commands to build complex test sequences, including: Forward characteristic test: Scan the forward current and measure the corresponding forward voltage drop; Reverse characteristic test: Apply reverse voltage and measure reverse leakage current; Dynamic characteristic testing: applying a fast pulse using a function generator to measure reverse recovery time and softness factor; and surge current testing; The data analysis engine can process the collected raw test data in real time, automatically calculate key parameters, and compare them with the specification limits retrieved from the model library to determine whether the diode is qualified or not; for unqualified products, it can also automatically record failure parameters and failure modes.

7. A test method based on the fully automated diode test system according to any one of claims 1 to 6, characterized in that, Includes the following steps: Step S1: The system powers on and performs a self-test. The test management server initializes each hardware module. The operator selects the model of the diode to be tested or imports a custom test process in the software interface and places the tray full of diodes to be tested on the tray support platform. Step S2, for each diode in the tray, the system performs the following sub-steps: Step S2.1, Visual Positioning and Grasping: The visual positioning system identifies the position and polarity of the diode, guiding the robotic arm to accurately grasp the diode; Step S2.2: The robotic arm places the diode in the precision test fixture at the test station and ensures a good electrical connection. Step S2.3: The test management server automatically applies a series of electrical stresses and simultaneously measures electrical parameters by controlling the programmable test resource array according to the preset test process. Step S2.4: The system collects measurement data, the data analysis engine processes the data in real time and compares it with the specification limits to determine whether the diode is qualified; Step S2.5: Based on the judgment result, the robotic arm places the diode into the corresponding qualified or unqualified product tray; Step S3: After a single batch of tests is completed, the test management server automatically generates a comprehensive test report that includes a test summary, statistical process control charts, a detailed list of test data, and non-conforming product analysis, and stores all the data in the database.

8. The test method according to claim 7, characterized in that: In step S2.4, at least one set of the following tests shall be performed: Forward voltage drop test: Control the programmable DC power supply to output one or more specified constant forward currents, and measure the forward voltage drop across the diode using a digital multimeter; Reverse leakage current test: Control the programmable DC power supply to output a specified reverse voltage, and measure the reverse current flowing through the diode using a digital multimeter; Reverse recovery time test: Control the programmable function generator to generate a rapidly switching square wave signal, causing the diode to switch from forward bias to reverse bias instantaneously. Use a digital multimeter or high-speed acquisition card to capture the current waveform, and use software algorithms to calculate the time required from the current zero crossing point to the reverse current decaying to the specified value, i.e., the reverse recovery time.

9. The test method according to claim 8, characterized in that: In step S2.4, for diodes that are determined to be unqualified, the system will record the specific test items, measured values ​​and the degree of deviation from specifications for their failure; when generating a test report, the system will automatically classify and statistically analyze the unqualified products and identify the main failure modes.

10. The test method according to claim 8, characterized in that: In the reverse recovery time test, the software algorithm further calculates the softness factor, which is defined as the ratio of the time required for the current to decay from the peak value to 10% of its value to the time required for it to decay from the peak value to 90% of its value in the reverse recovery current waveform, i.e., S=tb / ta.

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