Test apparatus, system and method for high-speed signal line impedance of optical modules

Abstract

This invention belongs to the field of optical communication technology and relates to a testing device, system, and method for testing the impedance of high-speed signal lines in optical modules. The testing device uses a multi-dimensional sliding stage unit for its probe fixture and is equipped with a front lens assembly, a bottom lens assembly, and a horizontal lens assembly to observe the specific position of the high-frequency probe on the PCB board, allowing the high-frequency probe to contact the high-speed pads under test. The testing device, used in conjunction with a display and a vector network analyzer, can measure the impedance of high-speed differential signal channels on the PCB board of a high-speed optical module. Its advantages include the ability to perform multiple sampling tests on incoming PCB boards without damaging them, effectively preventing PCB boards that do not meet impedance requirements from entering the downstream production process. This solves the technical problem that existing flexible PCB fixtures are unsuitable for impedance testing of high-speed optical module products and cannot intercept non-compliant PCB boards at the source of the product processing.

Description

Technical Field

[0001] This invention relates to the field of optical communication technology, and in particular to a testing device, system and method for testing the impedance of high-speed signal lines of optical modules. Background Technology

[0002] There are generally three locations for high-speed lines in a high-speed optical module: the high-speed differential signal channel from the PCB gold fingers to the DSP (Digital Signal Processing Unit) for transmitting / receiving; the high-speed differential signal channel from the DSP to the Driver (transmit driver chip); and the high-speed differential signal channel from the DSP to the TIA (Transmit Amplifier).

[0003] The impedance of the high-speed differential line from the gold finger to the DSP can be tested by connecting a test board to the gold finger and then connecting it to a vector network analyzer. This is a mature testing solution in the industry. A simple method for measuring the impedance of high-speed lines between the DSP and the Drive, and between the DSP and the TIA, is to customize a flexible test board fixture and solder it to the high-speed lines on the PCB (see the applicant's prior patent CN 113252985A). However, this method is only suitable for low-speed optical modules (10G / 25G / 100G, etc.) with single-wavelength rates below 25Gbps, and is not suitable for testing high-speed optical modules (400G / 800G / 1.6T, etc.). High-speed optical modules have high impedance requirements; large impedance deviations directly affect product performance and yield. Custom flexible PCB fixtures and PCB soldering can cause impedance abrupt changes, especially at 112G / 224G speeds, where the impedance abrupt changes are more pronounced, altering the entire TDR curve and affecting the measurement accuracy of high-speed modules. Insertion loss of the link introduces more uncertainty through two soldering operations, making it impossible to assess whether the product meets protocol insertion loss requirements. High-speed line spacing is typically 0.1mm to 0.4mm; soldering pads using a soldering iron easily leads to short circuits, requiring high soldering skills and being inconvenient to operate. Incoming PCB materials from manufacturers must undergo destructive testing (solder paste applied to pads prevents subsequent SMT), thus only random sampling is possible, making it impossible to intercept PCBs that do not meet impedance requirements. Summary of the Invention

[0004] (a) Technical problems to be solved

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides a testing device, system and testing method for the impedance of high-speed signal lines of optical modules. It solves the technical problems of existing test flexible board fixtures, which perform impedance testing by soldering to the PCB board of high-speed optical modules, which will damage the PCB board and have low measurement accuracy. They are not suitable for impedance testing of high-speed optical module products and cannot intercept non-compliant PCB boards at the source of product processing.

[0006] (II) Technical Solution

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

[0008] In a first aspect, embodiments of the present invention provide a testing device for the impedance of high-speed signal lines of an optical module, used to measure the impedance of the PCB gold fingers of a high-speed optical module to the DSP transmit / receive high-speed differential signal channel, the DSP to the Driver high-speed differential signal channel, and the DSP to the TIA high-speed differential signal channel. The device includes a probe fixture mounted on a base plate, a front lens assembly, a horizontal lens assembly, and a mounting bracket for fixing the PCB board. The probe fixture is equipped with a high-frequency probe for contacting the high-speed pads under test on the PCB board and connecting to a vector network analyzer for impedance testing. The probe fixture is used to adjust the contact point between the high-frequency probe and the high-speed pads under test. The front lens assembly is located above the mounting bracket and is used to form a front image of the position of the high-frequency probe and the PCB board in the XY plane, which is transmitted to a display in real time. The horizontal lens assembly is located behind the mounting bracket and is used to form a side image of the contact between the high-frequency probe and the PCB board in the Z-axis direction, which is transmitted to a display in real time.

[0009] Optionally, the PCB board includes a single PCB board and a PCB panel, and the fixing bracket correspondingly includes a single board fixing bracket and a panel fixing bracket; the single board fixing bracket includes a fixing seat, a movable locking rod, a pressure plate, a locking sliding block, and a PCB positioning seat; the fixing seat and the PCB positioning seat are installed on the base plate, and the PCB positioning seat is used to place the single PCB board; the pressure plate is installed on the top surface of the fixing seat, one end of the locking sliding block is slidably installed between the pressure plate and the fixing seat, and the other end extends out of the fixing seat; the movable locking rod is threadedly connected to the fixing seat and abuts against the locking sliding block, so that the locking sliding block abuts against the single PCB board and together with the PCB positioning seat clamps the single PCB board; the panel fixing bracket includes a dovetail slide assembly and a movable stage, the dovetail slide assembly is installed on the base plate, the movable stage is installed on the top surface of the dovetail slide assembly, and the PCB panel is installed on the movable stage.

[0010] Optionally, the probe fixture also includes a mounting base, a multi-dimensional slide unit, a side arm seat, a side arm rod, and a probe seat. The mounting base is mounted on a base plate, the multi-dimensional slide unit is mounted on the mounting base, and both ends of the side arm seat are connected to the multi-dimensional slide unit and the side arm rod, respectively. The high-frequency probe is mounted on the probe seat at an inward and downward angle and fixed to the free end of the side arm rod. The multi-dimensional slide unit is used to change the position of the high-frequency probe on the X-axis, Y-axis, and Z-axis. It includes an X-axis slide assembly, a Y-axis slide assembly, and a Z-axis slide assembly connected sequentially from bottom to top. The sliding directions of the three are different, and each includes a sliding platform, a fixed platform, and an adjusting rod. The sliding platform slides with the fixed platform, and the adjusting rod is threadedly connected to either the fixed platform or the sliding platform and abuts against the remaining platform to move the sliding platform relative to the fixed platform.

[0011] Optionally, the multi-dimensional slide unit also includes an angle slide assembly, which is installed inside the Z-axis slide assembly. The sliding platform of the angle slide assembly is provided with an arc-shaped slide groove, and the fixed platform of the angle slide assembly is provided with a protrusion that cooperates with the arc-shaped slide groove. By rotating the adjusting rod on the sliding platform, the adjusting rod touches the fixed platform, so that the sliding platform moves along the arc-shaped slide groove as the motion trajectory, thereby changing the test angle of the high-frequency probe.

[0012] Optionally, two probe holders are provided, located on both sides of the fixed bracket.

[0013] Optionally, the testing device also includes a bottom lens assembly, which includes a slide table connecting frame, a Z-axis sliding unit, a sliding plate, an X-axis slider, and a bottom camera. The slide table connecting frame is mounted on the base plate via a fixing plate. The Z-axis sliding unit is used to adjust the position of the bottom camera on the Z-axis, and its two sides are fixedly connected to the slide table connecting frame and the sliding plate, respectively. The X-axis slider slides in cooperation with a groove on the sliding plate along the X-axis direction to adjust the position of the bottom camera on the X-axis. The bottom camera slides along the Y-axis direction on the X-axis slider.

[0014] Optionally, the front-facing camera assembly includes a first side arm bracket, a first movable stage, a three-dimensional slide unit, a first mounting bracket, and a front-facing camera. A height adjustment column is mounted on the base plate, the first side arm bracket is connected to the height adjustment column, the first movable stage is mounted on the first side arm bracket, one end of the three-dimensional slide unit is fixedly connected to the first movable stage, and the other end is fixedly connected to the first mounting bracket. The front-facing camera is fixedly mounted on the first mounting bracket. By adjusting the three-dimensional slide unit, the position of the front-facing camera in the XYZ three-dimensional space can be changed to observe the position of the high-frequency probe on the front of the PCB board.

[0015] Optionally, the horizontal lens assembly includes a second side arm bracket, a second movable platform, a two-dimensional slide unit, a second mounting bracket, and a horizontal camera; the second side arm bracket is connected to a height adjustment column, the second movable platform is mounted on the second side arm bracket, the two sides of the two-dimensional slide unit are respectively fixedly connected to the second movable platform and the second mounting bracket, the horizontal camera is mounted on the second mounting bracket, and the two-dimensional slide unit is used to adjust the position of the horizontal camera in the XY axis plane.

[0016] Secondly, embodiments of the present invention provide a test system for the high-speed signal line impedance of an optical module, including the aforementioned test device, display, and vector network analyzer. The display is electrically connected to the front camera of the front lens assembly and the horizontal camera of the horizontal lens assembly, respectively, for displaying the status of the high-frequency probe on the PCB board. The vector network analyzer is electrically connected to the high-frequency probe for displaying the TDR curve of the high-speed differential signal channel under test on the PCB board.

[0017] Thirdly, embodiments of the present invention provide a method for testing the impedance of high-speed signal lines of optical modules. The method utilizes the aforementioned testing device for high-speed signal line impedance of optical modules to measure the impedance of incoming PCB boards. The testing method includes the following steps:

[0018] S1. Fix the PCB board on the mounting bracket, adjust the front camera of the front lens assembly and focus on the high-speed pad to be tested on the front of the PCB board, and adjust the horizontal camera of the horizontal lens assembly until the side of the PCB board is displayed on the monitor.

[0019] S2. Adjust the probe holder to move the high-frequency probe to the vicinity of the high-speed pad to be tested. The display shows the front and side images. Connect the high-frequency probe to the vector network analyzer via an RF cable.

[0020] S3. Start the vector network analyzer, set the parameters of the sweep frequency signal and run it. Fine-tune the high-frequency probe to be directly above the high-speed pad under test, observe the side image and slowly operate the probe holder to make the high-frequency probe fall. When the high-frequency probe is about to contact the high-speed pad under test, observe the vector network analyzer until the vector network analyzer displays the TDR curve of the high-speed differential signal channel under test.

[0021] S4. After completing the TDR curve measurement of one high-speed differential signal channel, slowly operate the probe fixture to move the high-frequency probe upwards in a small range, and then perform the TDR curve measurement of the next high-speed differential signal channel.

[0022] (III) Beneficial Effects

[0023] The beneficial effects of this invention are:

[0024] 1. This invention provides a testing device, system, and method for testing the impedance of high-speed signal lines in optical modules. The testing device utilizes a multi-dimensional sliding stage unit to adjust the position and angle of the high-frequency probes. It also incorporates a front lens assembly, a bottom lens assembly, and a horizontal lens assembly to assist in locating the high-speed pads of the high-speed differential signal channel under test. The device allows observation of the specific position of the high-frequency probes on the PCB board, ensuring contact between the high-speed pads and the probes. When used in conjunction with a display and a vector network analyzer, the testing device can quickly and accurately measure the impedance of the high-speed differential signal channels from the PCB gold fingers to the DSP transmit / receive signal channel and from the DSP to the driver in high-speed optical modules. The impedance testing of high-speed differential signal channels and DSP-TIA high-speed differential signal channels replaces existing soldering testing methods. It allows for multiple sampling tests on incoming PCBs without damaging them, effectively preventing PCBs that do not meet impedance requirements from entering the downstream production process. This solves the technical problems of existing test PCB fixtures, which perform impedance testing by soldering to high-speed optical module PCBs, damaging the PCBs and rendering them unusable in subsequent production, and having low measurement accuracy. These issues make it unsuitable for impedance testing of high-speed optical module products and prevent the interception of non-compliant PCBs at the source of the product processing.

[0025] 2. Keep the high-frequency probe of the left probe holder tilted downward and inward, and flip the side arm of the right probe holder 180° and install it on the side arm seat so that the high-frequency probe of the right side tilts upward and inward. This allows impedance testing of both sides of the PCB board, which can more accurately reflect the quality of the PCB board in terms of impedance.

[0026] 3. It can test both single PCB boards and PCB panels, making the device more flexible and practical, and reducing bare PCB losses caused by test impedance.

[0027] 4. The testing equipment can accurately and quickly test the impedance value of the high-speed differential signal channel on the PCB board, monitor the quality of the incoming PCB board, and provide timely feedback to the PCB board manufacturer so that the manufacturer can adjust production parameters and optimize the impedance of the PCB board accordingly, ensuring the consistency of the quality of the incoming PCB board and thus improving the quality of high-speed optical module products. Attached Figure Description

[0028] Figure 1 This is a three-dimensional schematic diagram of the probe testing device in Embodiment 1 of the present invention, which describes a testing device, system and method for testing the impedance of a high-speed signal line of an optical module.

[0029] Figure 2 This is an exploded view of the probe testing device in Embodiment 1 of the present invention, which describes a testing device, system and method for testing the impedance of a high-speed signal line of an optical module.

[0030] Figure 3 This is a cross-sectional schematic diagram of the probe testing device in Embodiment 1 of the present invention, which describes a testing device, system and method for testing the impedance of a high-speed signal line of an optical module.

[0031] Figure 4 This is an enlarged schematic diagram of the front lens assembly of the probe testing device in Embodiment 1 of the present invention, which is a test device, system and test method for the high-speed signal line impedance of an optical module.

[0032] Figure 5 This is an enlarged schematic diagram of the bottom lens assembly of the probe testing device in Embodiment 1 of the present invention, which is a test device, system and method for testing the impedance of a high-speed signal line of an optical module.

[0033] Figure 6 This is an enlarged schematic diagram of the horizontal lens assembly of the probe testing device in Embodiment 1 of the present invention, which is a test device, system and test method for testing the impedance of a high-speed signal line of an optical module.

[0034] Figure 7 This is an enlarged schematic diagram of the single-board mounting bracket of the probe testing device in Embodiment 1 of the present invention, which describes a testing device, system and method for testing the impedance of a high-speed signal line of an optical module.

[0035] Figure 8 This is an exploded view of the single-board mounting bracket of the probe testing device in Embodiment 1 of the present invention, which is a test device, system and method for testing the impedance of high-speed signal lines of optical modules.

[0036] Figure 9 This is an exploded view of the panel fixing frame of the probe testing device in Embodiment 1 of the present invention, which is a test device, system and test method for high-speed signal line impedance of an optical module.

[0037] Figure 10 This is an enlarged schematic diagram of the probe fixture of the probe testing device in Embodiment 1 of the present invention, which is a test apparatus, system and method for testing the impedance of a high-speed signal line of an optical module.

[0038] Figure 11 This is an exploded view of the probe fixture of the probe testing device in Embodiment 1 of the present invention, which is a test apparatus, system and method for testing the impedance of a high-speed signal line of an optical module.

[0039] Figure 12 This is a schematic diagram of a probe testing system in Embodiment 2 of the present invention, which describes a testing device, system, and method for testing the impedance of a high-speed signal line of an optical module.

[0040] Figure 13This is a table showing the impedance values ​​from the gold fingers of the PCB board to the DSP, as part of an embodiment 3 of the present invention, which is a test device, system, and method for testing the impedance of high-speed signal lines of optical modules.

[0041] Figure 14 This is a TDR curve of the DSP to Driver high-speed differential signal channel on the PCB board of an embodiment 3 of the present invention, which is a test device, system and test method for the high-speed signal line impedance of an optical module.

[0042] Figure 15 This is a TDR curve of the DSP to TIA high-speed differential signal channel on the PCB board of an embodiment 3 of the present invention, which is a test device, system and test method for the high-speed signal line impedance of an optical module.

[0043] Figure 16 This is a partial PCB view of Embodiment 3 of the present invention, which describes a test device, system, and method for testing the impedance of a high-speed signal line of an optical module.

[0044] [Explanation of Labels in the Attached Image]

[0045] 1. Base plate; 10. Height adjustment column;

[0046] 20. Single board fixing frame; 201. Support frame; 202. Adapter plate; 203. Fixing base; 204. Moving locking rod; 205. Pressure plate; 206. Locking sliding block; 207. PCB positioning base;

[0047] 21. Panel fixing frame; 211. Dovetail groove slide assembly; 212. Movable table;

[0048] 3. Probe clamp; 31. Mounting base; 32. Multi-dimensional slide unit; 321. X-axis slide assembly; 322. Y-axis slide assembly; 323. Z-axis slide assembly; 324. Angle slide assembly; 3241. Arc-shaped slide groove; 33. Side arm seat; 34. Side arm rod; 35. High-frequency probe;

[0049] 4. Front lens assembly; 40. Mount locking handle; 41. First side arm bracket; 42. First movable mount; 43. Three-dimensional slide unit; 44. First mounting bracket; 45. Front camera;

[0050] 5. Bottom lens assembly; 51. Fixing plate; 52. Slide table connecting bracket; 53. Z-axis sliding unit; 55. X-axis slider; 56. Sliding plate; 561. Straight slide groove; 57. Bottom camera; 58. Adjusting bolt;

[0051] 6. Horizontal lens assembly; 61. Second side arm support; 62. Second movable platform; 63. Second mounting bracket; 64. Two-dimensional slide unit; 65. Horizontal camera;

[0052] 71. PCB single board; 72. PCB panel;

[0053] 8. Monitor;

[0054] 9. Vector Network Analyzer. Detailed Implementation

[0055] To better explain and facilitate understanding of the present invention, a detailed description of the invention is provided below with reference to the accompanying drawings and specific embodiments. In this document, directional terms such as "upper" and "lower" are used interchangeably with other directional terms. Figure 1 With the orientation as a reference, the direction of the single-board fixing bracket 20 is "front", the direction of the horizontal lens assembly 6 is "back", corresponding to the Y-axis; the left probe clamp 3 is "left", the right probe clamp 3 is "right", corresponding to the X-axis; the direction of the height adjustment column 10 is "up", and the direction of the base plate 1 is "down", corresponding to the Z-axis.

[0056] This invention provides a testing device, system, and method for testing the high-speed signal line impedance of an optical module. The testing device utilizes a multi-dimensional sliding stage unit to adjust the position and angle of the high-frequency probes. It also incorporates a front lens assembly, a bottom lens assembly, and a horizontal lens assembly to assist in locating the high-speed pads of the high-speed differential signal channel under test. This allows observation of the high-frequency probes' specific positions on the PCB board, ensuring contact with the high-speed pads. The testing device, used in conjunction with a display and a vector network analyzer, can quickly and accurately measure the impedance of the high-speed optical module's PCB gold fingers to the DSP transmit / receive high-speed differential signal channel, and the impedance of the DSP to the D... The impedance of the River high-speed differential signal channel and the DSP-TIA high-speed differential signal channel is tested. Its advantages include replacing existing soldering testing methods, allowing for multiple sampling tests on incoming PCBs without damaging them, effectively preventing PCBs that do not meet impedance requirements from entering the downstream production process. This solves the technical problems of existing test PCB fixtures, which, by soldering to high-speed optical module PCBs for impedance testing, damage the PCBs, rendering them unusable in subsequent production, and have low measurement accuracy, making them unsuitable for impedance testing of high-speed optical module products and unable to intercept non-compliant PCBs at the source of the product processing.

[0057] To better understand the above technical solutions, exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention can be understood more clearly and thoroughly, and that the scope of the present invention can be fully conveyed to those skilled in the art.

[0058] Example 1:

[0059] Reference Figures 1 to 3 This embodiment 1 provides a test device for the impedance of high-speed signal lines of an optical module, used to measure the impedance of the PCB gold fingers of the high-speed optical module to the DSP transmit / receive high-speed differential signal channel, the DSP to the Driver high-speed differential signal channel, and the DSP to the TIA high-speed differential signal channel. It includes a probe fixture 3, a front lens assembly 4, a horizontal lens assembly 6, and a fixing bracket mounted on a base plate 1.

[0060] The probe fixture 3 is set along the X-axis and is equipped with a high-frequency probe 35. The probe fixture 3 is used to adjust the contact point between the high-frequency probe 35 and the high-speed pad under test on the PCB board in three dimensions. The high-frequency probe 35 is used to touch the high-speed pad under test and connect to the vector network analyzer 9 for impedance testing.

[0061] The front lens assembly 4 is set along the Z-axis and above the fixed bracket. The front lens assembly 4 is used to form a front image of the position of the high-frequency probe 35 and the PCB board in the XY plane and transmit it to the display 8 in real time via cable.

[0062] The horizontal lens assembly 6 is set along the Y-axis and located behind the fixed bracket. It is used to form a side image of the contact between the high-frequency probe 35 and the PCB board in the Z-axis direction and transmit it to the display 8 in real time via cable.

[0063] In this application, the description of the arrangement of each component along the X, Y, or Z axis is only for the purpose of clearly describing the relative relationship between the components.

[0064] The front lens assembly 4, the bottom lens assembly 5 (described later), and the horizontal lens assembly 6 all transmit real-time images to the display 8 via cables, forming multiple split-screen images. This allows operators to easily observe the position of the PCB board and the high-frequency probe 35 in various directions, ensuring that the high-frequency probe 35 accurately lands on the high-speed pads of the high-speed differential signal channel under test without damaging the PCB board, thus greatly improving testing efficiency.

[0065] See Figures 7 to 9 In some feasible solutions, the probe fixture 3 has the function of testing PCB single boards 71 ​​and PCB panels 72. The PCB board includes PCB single boards 71 ​​and PCB panels 72. Correspondingly, the fixing bracket includes single board fixing bracket 20 and panel fixing bracket 21. The PCB panel 72 is composed of 10 to 12 PCB single boards 71 ​​to form a large PCB. The size of different PCB panels 72 is also different. Therefore, in order to facilitate compatibility with PCB panels 72 of different sizes and to facilitate the movement of PCB single boards 71 ​​in different areas to a suitable position on the high-frequency probe 35, tape fixing is usually used for testing.

[0066] It should be noted that, due to practical factors such as cost and production difficulty, manufacturers mostly produce PCB panels 72 rather than PCB single boards 71. Furthermore, if PCB single boards 71 ​​are removed from PCB panels 72 for testing, the removed PCB panels 72 cannot be used for surface mount technology (SMT) at the assembly plant, resulting in waste. Therefore, this application adds a panel testing function to save costs.

[0067] See Figure 7 and Figure 8 The single-board fixing frame 20 includes a fixing base 203, a movable locking rod 204, a pressure plate 205, a locking sliding block 206, and a PCB positioning base 207. The fixing base 203 and the PCB positioning base 207 are installed sequentially on the base plate 1 from front to back. The PCB positioning base 207 is used to position and place the PCB single board 71. The pressure plate 205 is bolted to the top surface of the fixing base 203. One end of the locking sliding block 206 is slidably installed between the pressure plate 205 and the fixing base 203, and the other end extends out of the fixing base 203. The movable locking rod 204 is threadedly connected to the fixing base 203 and abuts against the locking sliding block 206. In use, rotating the movable locking rod 204 pushes the locking sliding block 206 to abut against the PCB single board 71, and together with the PCB positioning base 207, clamps the PCB single board 71.

[0068] like Figure 8 As shown, in practical applications, the single-board fixing frame 20 also includes a support frame 201 and an adapter plate 202. The support frame 201 is bolted to the base plate 1, and the adapter plate 202 is bolted to the top surface of the support frame 201, forming a rearward-extending platform. The fixing seat 203 and the PCB positioning seat 207 are sequentially installed on the top surface of this platform from front to back. The PCB positioning seat 207 has an L-shaped cross-section and a positioning groove at its top, which, together with the locking sliding block 206, clamps one end of the PCB single board 71.

[0069] See Figure 9 The panel mounting bracket 21 includes a dovetail slide assembly 211 and a movable platform 212. The dovetail slide is mounted on the base plate 1, and the movable platform 212 is mounted on the top surface of the dovetail slide assembly 211 by bolts. The PCB panel 72 is mounted on the movable platform 212.

[0070] In practical applications, the panel fixing frame 21 is also equipped with a support frame 201 to raise its own height. The support frame 201 is connected to the dovetail slide assembly 211 by bolts. The dovetail slide assembly 211 includes a fixed platform, a sliding platform, and a threaded rod that are fixed to the support frame 201. The threaded rod is threaded to the fixed platform and abuts against the sliding platform, allowing the sliding platform to slide relative to the fixed platform. The sliding fit structure between the fixed platform and the sliding platform is dovetail-shaped, which makes the movement of the sliding platform more stable.

[0071] See Figure 10 In some feasible solutions, the probe holder 3 also includes a mounting base 31, a multi-dimensional slide unit 32, a side arm seat 33, a side arm rod 34, and a probe holder. The mounting base 31 is bolted to the base plate 1, and the multi-dimensional slide unit 32 is bolted to the mounting base 31. The two ends of the side arm seat 33 are respectively connected to the multi-dimensional slide unit 32 and the side arm rod 34. The high-frequency probe 35 is mounted on the probe holder at an inward and downward angle and fixed to the free end of the side arm rod 34. "Inward" refers to the direction towards the center of the base plate 1.

[0072] See Figure 11 The multi-dimensional slide unit 32 is used to change the position of the high-frequency probe 35 in the X, Y, and Z axes. It includes an X-axis slide assembly 321, a Y-axis slide assembly 322, and a Z-axis slide assembly 323 connected sequentially from bottom to top. Each assembly includes a sliding platform, a fixed platform, an adjusting rod, and a locking rod. The sliding platform slides into the fixed platform. The adjusting rod is threaded onto either the fixed or sliding platform and abuts against the remaining platform, allowing the sliding platform to move relative to the fixed platform. Similarly, the locking rod is threaded onto either the fixed or sliding platform and, after adjusting the position of the sliding platform, abuts against the remaining platform to prevent further movement and achieve a locking effect. The multi-dimensional slide unit 32 can provide a movement range of ±6.5 mm in the XYZ three-dimensional directions, with an adjustment accuracy of up to 0.5 μm.

[0073] Taking the Y-axis slide assembly 322 as an example, the Y-axis slide assembly 322 includes a sliding platform, a fixed platform, an adjusting rod, and a locking rod. The fixed platform is fixedly mounted on the base, and the sliding platform is generally in an inverted U-shape, sliding over the fixed platform. The adjusting rod is threadedly connected to an extension at one end of the fixed platform. By rotating the adjusting rod, it contacts and pushes the sliding platform to slide on the fixed platform, thereby realizing the movement of the high-frequency probe 35 in the Y-axis direction. The locking rod is threadedly connected to one side of the sliding platform and passes through the sliding platform to contact the side wall of the fixed platform. After the high-frequency probe 35 has moved in the Y-axis direction, the locking rod is rotated to lock the sliding platform. The sliding platform of the Y-axis slide assembly 322 is fixedly connected to the fixed platform of the Z-axis slide assembly 323.

[0074] The Z-axis slide assembly 323 is vertically positioned, with one end of its adjusting rod threadedly connected to the sliding platform and contacting the fixed platform. During adjustment, rotating the adjusting rod causes it to move downwards and contact the fixed platform, thereby moving the sliding platform upwards relative to the fixed platform.

[0075] It should be noted that in this application, the structures and working principles of each slide assembly of the multi-dimensional slide unit 32 are basically the same, with only the sliding direction being different, and the adaptive changes made due to the different sliding direction; the structure of the two-dimensional slide unit 64 of the horizontal lens assembly 6 is different from that of the multi-dimensional slide unit 32 in that it has or does not have a Z-axis slide assembly 323; the structure and working principle of the Z-axis sliding unit 53 of the bottom lens assembly 5 are the same as those of the Z-axis slide assembly 323 of the multi-dimensional slide unit 32, so they will not be described in detail.

[0076] See Figure 11 Furthermore, the multi-dimensional slide unit 32 also includes an angle slide assembly 324, which is installed inside the Z-axis slide assembly 323. The sliding platform of the angle slide assembly 324 is provided with an arc-shaped slide groove 3241, and the fixed platform of the angle slide assembly 324 is provided with a protrusion that cooperates with the arc-shaped slide groove 3241. By rotating the adjusting rod on the sliding platform, the adjusting rod touches the fixed platform, so that the sliding platform moves along the arc-shaped slide groove 3241 as the motion trajectory, causing the high-frequency probe 35 to swing back and forth to adjust the horizontal angle of the probe and change the test angle of the high-frequency probe 35. The horizontal angle can be ±2.5° or adjusted according to actual needs. Therefore, the angle at which the high-frequency probe 35 falls on the high-speed pad under test can be flexibly changed according to the actual situation of the high-frequency probe 35 and the high-speed pad under test, ensuring that the height and orientation of the high-frequency probe 35 falling are more accurate, without damaging the high-frequency probe 35 and the high-speed pad under test, and making the test results more accurate.

[0077] In some feasible solutions, the testing device can simultaneously perform impedance tests on both sides of the PCB board 71. Two probe holders 3 are provided, symmetrically arranged on the left and right sides of the board mounting bracket 20 along the X-axis. The side arm 34 of the left probe holder 3 is mounted facing forward (e.g., Figure 10 As shown, the high-frequency probe 35 is tilted downward and inward to test the front side of the PCB board 71. The side arm 34 of the probe clamp 3 on the right side is rotated 180° and installed in the opposite direction on the side arm seat 33, so that the high-frequency probe 35 is tilted upward and inward, and the impedance test of the back side of the PCB board 71 can be performed, thereby realizing the function of simultaneously performing impedance tests on the front and back sides of the PCB board 71.

[0078] Simultaneously performing impedance testing on both sides of PCB board 71 can more accurately reflect the impedance quality of PCB board 71. For high-speed differential signal channels, i.e., high-speed lines that run from the front of the PCB board through holes to the back (e.g., DSP on the front, TIA / Driver on the back), when it is necessary to measure the S-parameters of the entire channel, impedance testing on both sides of PCB board 71 is required to ensure that the loss of the entire link is within the 3dB loss range. S-parameters include differential insertion loss.

[0079] See Figure 5The bottom lens assembly 5 includes a slide connecting frame 52, a Z-axis sliding unit 53, a sliding plate 56, an X-axis slider 55, and a bottom camera 57.

[0080] The slide table connecting frame 52 is mounted on the base plate 1 via a fixing plate 51. The Z-axis sliding unit 53 is used to adjust the position of the bottom camera 57 on the Z-axis, changing the focal length between the bottom camera 57 and the PCB board 71. Its two sides are fixedly connected to the slide table connecting frame 52 and the sliding plate 56, respectively. The X-axis slider 55 slides in conjunction with the straight slide groove 561 set along the X-axis direction on the sliding plate 56, and is used to adjust the position of the bottom camera 57 on the X-axis. The X-axis slider 55 is threaded with an adjusting bolt 58. By rotating the adjusting bolt 58, the locking of the bottom camera 57 is released, allowing the bottom camera 57 to slide along the Y-axis direction on the X-axis slider 55. This enables the bottom camera 57 to move freely in the XY-axis plane to observe the pads on the back of the PCB board 71.

[0081] The bottom lens assembly 5 is set up to form an image of the back of the PCB board 71 by the high-frequency probe 35 on the right side when the front and back sides of the PCB board 71 are tested at the same time, and transmit the image to the display 8 in real time via cable.

[0082] See Figure 1 and Figure 4 In some feasible solutions, the front lens assembly 4 includes a first side arm bracket 41, a first movable platform 42, a three-dimensional sliding table unit 43, a first mounting bracket 44, and a front camera 45.

[0083] A height adjustment column 10 is mounted on the base plate 1. The first side arm bracket 41 is bolted to the height adjustment column 10. The first movable platform 42 is mounted on the first side arm bracket 41. One end of the three-dimensional slide unit 43 is fixedly connected to the first movable platform 42, and the other end is fixedly connected to the first mounting bracket 44. The front camera 45 is fixedly mounted on the first mounting bracket 44. The main difference between the three-dimensional slide unit 43 and the multi-dimensional slide unit 32 is that the three-dimensional slide unit 43 has no angle slide assembly 324, which will not be described in detail here. By adjusting the three-dimensional slide unit 43, the position of the front camera 45 in the XYZ three-dimensional space can be finely adjusted, with a movement range of ±6.5mm, to observe the position of the high-frequency probe 35 on the front of the PCB board. The three-dimensional slide unit 43 is used in the Z-axis direction to adjust the focal length between the front camera 45 and the PCB board.

[0084] The first movable platform 42 moves on the first side arm bracket 41 to achieve coarse adjustment of the front camera 45 in the Y-axis direction, increasing the observation range of the short side of the PCB board. After the coarse adjustment is completed, the first movable platform 42 is locked by rotating the platform locking handle 40. One end of the platform locking handle 40 is threadedly connected to the first movable platform 42 and can contact the first side arm bracket 41 to achieve the locking function.

[0085] See Figure 6 As a feasible solution, the horizontal lens assembly 6 includes a second side arm support 61, a second movable platform 62, a two-dimensional slide unit 64, a second mounting bracket 63, and a horizontal camera 65.

[0086] The second side arm bracket 61 is bolted to the height adjustment column 10. The second movable platform 62 is mounted on the second side arm bracket 61. The two sides of the two-dimensional slide unit 64 are fixedly connected to the second movable platform 62 and the second mounting bracket 63, respectively. The horizontal camera 65 is mounted on the second mounting bracket 63. The two-dimensional slide unit 64 is used to adjust the position of the horizontal camera 65 in the XY axis plane, with a movement range of ±6.5mm. The second movable platform 62 moves on the second side arm bracket 61 to achieve coarse adjustment of the horizontal camera 65 in the X-axis direction, increasing the observation range of the long side of the PCB board.

[0087] Example 2:

[0088] See Figure 12 Based on Embodiment 1, Embodiment 2 provides a test system for the high-speed signal line impedance of an optical module, including the aforementioned test device, display 8, and vector network analyzer 9. The display 8 is electrically connected to the front camera 45, the bottom camera 57, and the horizontal camera 65 to display the status of the high-frequency probe 35 on the PCB board. The vector network analyzer 9 is electrically connected to the high-frequency probe 35 to display the TDR curve of the high-speed differential signal channel under test on the PCB board.

[0089] Both the display 8 and the vector network analyzer 9 are commercially available and mature products. The electrical signals between the cameras and the display 8, and between the vector network analyzer 9 and the high-frequency probe 35, can be connected via cables or wirelessly using existing technologies such as Bluetooth.

[0090] Example 3:

[0091] This embodiment 3 provides a method for testing the impedance of high-speed signal lines of optical modules. The aforementioned testing device is used to measure the impedance of incoming PCB boards to reduce the inflow of PCB boards with out-of-tolerance impedance into the back end of the production process, and to promptly notify the PCB board manufacturer to adjust production parameters.

[0092] Taking the impedance test of the DSP to TIA high-speed differential signal channel on PCB panel 72 as an example, the test method includes the following steps:

[0093] S1. Fix the PCB panel 72 on the panel holder 21, adjust the front camera 45 and focus on the high-speed pad to be tested on the front of the PCB panel 72, display the front image on the display 8, adjust the horizontal camera 65 until the side image is displayed on the display 8, display the side of the PCB panel 72, so as to facilitate subsequent observation of the falling height of the high-frequency probe 35.

[0094] Before step S1, the front camera 45 of the front lens assembly 4, the horizontal camera 65 of the horizontal lens assembly 6, and the bottom camera 57 of the bottom lens assembly 5 need to be connected to the display 8 via cables and electrical signals.

[0095] S2. Adjust the probe holder 3 to move the high-frequency probe 35 to the vicinity of the high-speed pad to be tested. The display 8 shows the front and side images. Connect the high-frequency probe 35 to the vector network analyzer 9 via an RF cable.

[0096] S3. Start the vector network analyzer 9, set the parameters of the excitation signal and run it. Fine-tune the high-frequency probe 35 to be directly above the high-speed pad under test. Observe the side image and slowly operate the probe holder 3 to make the high-frequency probe 35 fall. When the high-frequency probe 35 is about to contact the high-speed pad under test, observe the vector network analyzer 9 until the vector network analyzer 9 displays the TDR curve (Time Domain Reflectometry Curve) of the high-speed differential signal channel under test.

[0097] The excitation signal emitted by the Vector Network Analyzer 9 is a frequency sweep signal (CW / differential frequency sweep).

[0098] S4. After completing the TDR curve measurement of one high-speed differential signal channel, slowly operate the probe fixture 3 to move the high-frequency probe 35 upward within a small range, and then perform the TDR curve measurement of the next high-speed differential signal channel.

[0099] Since the high-speed pads to be tested are very small, the image range focused by the front camera 45 is relatively small, and the high-frequency probe 35 requires precise alignment and is easily damaged, so it can only be moved a small distance. Therefore, the front camera 45 and the high-frequency probe 35 do not need to be moved over a large range to avoid refocusing. By adjusting the dovetail slide assembly 211, the PCB panel 72 can be moved over a large range, so that the high-speed differential signal channel to be tested can be moved horizontally below the front camera 45 and the high-frequency probe 35. The operation is very convenient, simple and efficient.

[0100] Figure 14The TDR curve of the high-speed differential signal channel from DSP to DRIVER is shown in the figure. Figure 16 It can be seen that the top layer coupling capacitor is replaced with a bottom layer via. Figure 16 At point C, there is a sudden change in impedance, with the impedance value dropping to 83.39Ω. The coordinate point on the TDR curve is C (262.5ps, 83.39Ω).

[0101] Figure 15 The TDR curve of the DSP to TIA high-speed differential signal channel is shown in the figure. Figure 16 It can be seen that the L3 layer of the PCB board is switched to the bottom via ( Figure 16 The impedance at point H in the curve shows a sudden change, with the impedance value dropping to 83.17Ω. The coordinates of this point on the TDR curve are H (390.0ps, 83.17Ω). Due to the sudden drop in impedance values ​​at these two points, re-simulation and optimization are required, and new requirements are put forward for the processing accuracy of the bottom vias by the board manufacturer.

[0102] In this invention, L1, L3, L8, etc., refer to the layer sequence of a multilayer optical module PCB board.

[0103] Using the testing device of this invention, the impedance value on the PCB board can be accurately measured. During testing of an 800G optical module project, it was found that the impedance from the L3 layer gold fingers to the DSP on the optical module PCB board was 102.5Ω, which is at the upper limit of the standard, while the impedance from the L8 layer gold fingers to the DSP was 96Ω, which is more in line with the target value (the impedance standard given to the PCB board manufacturer is 95 + / - 8% Ω). After product testing, the bit error rate of channels CH1, 3, 5, and 7 on the L8 layer was two orders of magnitude higher than that of channels CH2, 4, 6, and 8 on the L3 layer, significantly affecting product compatibility. Subsequent optimization of the L3 layer impedance by the PCB board manufacturer improved the overall product bit error rate by more than two orders of magnitude. Specific testing details are as follows... Figure 13 As shown. The bit error rate is in scientific notation, where 3.30E-12 is... This means that for every trillion bits (10^12) transmitted 12 The data shows an average of 3.3 error bits.

[0104] Previously, quality control personnel would test the impedance of incoming PCB boards using the following methods:

[0105] 1. Obtain the impedance test report provided by the PCB manufacturer. Because there may be a test impedance error between the impedance strip provided by the PCB manufacturer and the impedance on the PCB itself, the impedance value of the incoming PCB may deviate from the upper or lower limits, or even exceed the tolerance range.

[0106] 2. Testing is performed by selecting and disassembling PCB panel 72, and then soldering RF flexible boards. The disadvantages are wasting PCB boards, wasting significant manpower and time on soldering tests, and potentially introducing inaccurate test results if the soldering is poor.

[0107] 3. Finished product via PCB board. After casing, it is tested via a test board. However, this is already the finished product stage. If the impedance exceeds the standard or the performance is poor, it will lead to the scrapping of the entire product and significant production losses.

[0108] The testing system described in this application allows for random sampling and testing of incoming PCB boards. The operation is simple and quick; personnel can begin testing after training. Testing efficiency is at least 10 times higher than existing soldering-based testing methods. This reduces the influx of PCB boards with out-of-tolerance impedance into the later stages of production and allows for timely feedback to PCB manufacturers to adjust production parameters, ensuring product performance. In terms of product development, since the impedance of each high-speed differential signal channel on the PCB board can be accurately measured, high-performance PCB boards can be used for R&D activities, significantly reducing development costs and time.

[0109] It is particularly important to note that if the high-frequency probe 35 falls excessively during testing, it can easily damage both the high-frequency probe 35 and the PCB board. The multi-dimensional slide unit 32 of the probe holder 3 allows the high-frequency probe to be accurately moved above the high-speed pad under test. The three lens assemblies provide multiple perspectives, assisting operators in accurately judging the height and position of the high-frequency probe 35 as it falls, preventing it from falling excessively. Therefore, the probe holder 3 and the three lens assemblies are indispensable and form an inseparable whole.

[0110] In the description of this invention, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0111] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0112] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first and second features are in direct contact, or that they are in indirect contact through an intermediate medium. Furthermore, "above," "over," or "on top" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," or "beneath" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0113] In the description of this specification, the terms "one embodiment," "some embodiments," "embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. 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. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0114] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make modifications, alterations, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A testing device for the impedance of high-speed signal lines in an optical module, characterized in that: The impedance of the PCB gold fingers of the high-speed optical module to the DSP transmit / receive high-speed differential signal channel, the DSP to the Driver high-speed differential signal channel and the DSP to the TIA high-speed differential signal channel is measured. The device includes a probe clamp (3) mounted on the base plate (1), a front lens assembly (4), a horizontal lens assembly (6) and a fixing bracket for fixing the PCB. The probe fixture (3) is equipped with a high-frequency probe (35) for contacting the high-speed pad under test on the PCB board and connecting to a vector network analyzer (9) for impedance testing. The probe fixture (3) is used to adjust the contact point between the high-frequency probe (35) and the high-speed pad under test. The front lens assembly (4) is located above the fixed bracket. The front lens assembly (4) is used to form a front image of the position of the high-frequency probe (35) and the PCB board in the XY plane and transmit it to the display (8) in real time. The horizontal lens assembly (6) is located behind the fixed bracket and is used to transmit a side image of the contact between the high-frequency probe (35) and the PCB board in the Z-axis direction to the display (8) in real time. The probe fixture (3) also includes a mounting base (31), a multi-dimensional slide unit (32), a side arm seat (33), a side arm rod (34), and a probe seat. The mounting base (31) is mounted on the base plate (1), the multi-dimensional slide unit (32) is mounted on the mounting base (31), and the two ends of the side arm seat (33) are respectively connected to the multi-dimensional slide unit (32) and the side arm rod (34). The high-frequency probe (35) is mounted on the probe seat and fixed to the free end of the side arm rod (34). The multi-dimensional slide unit (32) is used to change the position of the high-frequency probe (35) on the X-axis, Y-axis and Z-axis. It includes an X-axis slide assembly (321), a Y-axis slide assembly (322) and a Z-axis slide assembly (323) connected from bottom to top. The three slide in different directions and each includes a sliding platform, a fixed platform and an adjusting rod. The sliding platform slides with the fixed platform. The adjusting rod is threaded to either the fixed platform or the sliding platform and touches the other platform so that the sliding platform moves relative to the fixed platform.

2. The testing device for the high-speed signal line impedance of an optical module as described in claim 1, characterized in that: The PCB board includes a single PCB board (71) and a PCB panel (72), and the fixing bracket includes a single board fixing bracket (20) and a panel fixing bracket (21). The single board fixing frame (20) includes a fixing base (203), a movable locking rod (204), a pressure plate (205), a locking sliding block (206), and a PCB positioning base (207). The fixing seat (203) and the PCB positioning seat (207) are mounted on the base plate (1), and the PCB positioning seat (207) is used to place the PCB board (71). The pressure plate (205) is installed on the top surface of the fixed base (203). One end of the locking sliding block (206) is slidably installed between the pressure plate (205) and the fixed base (203), and the other end extends out of the fixed base (203). The movable locking rod (204) is threadedly connected to the fixed base (203) and abuts against the locking sliding block (206) so that the locking sliding block (206) abuts against the PCB board (71) and together with the PCB positioning base (207) clamps the PCB board (71). The panel fixing frame (21) includes a dovetail slide assembly (211) and a movable platform (212). The dovetail slide is installed on the base plate (1), the movable platform (212) is installed on the top surface of the dovetail slide assembly (211), and the PCB panel (72) is installed on the movable platform (212).

3. The testing device for the high-speed signal line impedance of an optical module as described in claim 2, characterized in that: The multi-dimensional slide unit (32) also includes an angle slide assembly (324), which is installed inside the Z-axis slide assembly (323). The sliding platform of the angle slide assembly (324) is provided with an arc-shaped slide groove (3241), and the fixed platform of the angle slide assembly (324) is provided with a protrusion that cooperates with the arc-shaped slide groove (3241). By rotating the adjusting rod on the sliding platform, the adjusting rod touches the fixed platform, so that the sliding platform moves along the arc-shaped slide groove (3241) as the motion trajectory, thereby changing the test angle of the high-frequency probe (35).

4. The testing device for the high-speed signal line impedance of an optical module as described in claim 2, characterized in that: The probe clamp (3) is provided in two parts, located on both sides of the fixed bracket.

5. The testing device for the high-speed signal line impedance of an optical module as described in claim 4, characterized in that: The testing device also includes a bottom lens assembly (5), which includes a slide table connecting frame (52), a Z-axis sliding unit (53), a sliding plate (56), an X-axis slider (55), and a bottom camera (57). The slide table connecting frame (52) is mounted on the base plate (1) by a fixing plate (51). The Z-axis sliding unit (53) is used to adjust the position of the bottom camera (57) on the Z-axis. Its two sides are fixedly connected to the slide table connecting frame (52) and the sliding plate (56) respectively. The X-axis slider (55) slides and engages with the groove set along the X-axis direction on the sliding plate (56) to adjust the position of the bottom camera (57) on the X-axis. The bottom camera (57) is slidably set on the X-axis slider (55) along the Y-axis direction.

6. The testing device for the high-speed signal line impedance of an optical module as described in claim 1, characterized in that: The front lens assembly (4) includes a first side arm bracket (41), a first movable platform (42), a three-dimensional sliding table unit (43), a first mounting bracket (44), and a front camera (45). A height adjustment column (10) is installed on the base plate (1). The first side arm bracket (41) is connected to the height adjustment column (10). The first movable platform (42) is installed on the first side arm bracket (41). One end of the three-dimensional slide unit (43) is fixedly connected to the first movable platform (42), and the other end is fixedly connected to the first mounting bracket (44). The front camera (45) is fixedly installed on the first mounting bracket (44). The position of the front camera (45) in the XYZ three-dimensional space is changed by adjusting the three-dimensional slide unit (43) to observe the position of the high-frequency probe (35) on the front of the PCB board.

7. The testing device for the high-speed signal line impedance of an optical module as described in claim 6, characterized in that: The horizontal lens assembly (6) includes a second side arm bracket (61), a second movable platform (62), a two-dimensional slide unit (64), a second mounting bracket (63), and a horizontal camera (65). The second side arm bracket (61) is connected to the height adjustment column (10), the second movable platform (62) is installed on the second side arm bracket (61), the two sides of the two-dimensional slide unit (64) are fixedly connected to the second movable platform (62) and the second mounting bracket (63) respectively, the horizontal camera (65) is installed on the second mounting bracket (63), and the two-dimensional slide unit (64) is used to adjust the position of the horizontal camera (65) in the XY axis plane.

8. A test system for the impedance of high-speed signal lines in optical modules, characterized in that: The device includes a test apparatus as described in any one of claims 1 to 7, a display (8), and a vector network analyzer (9). The display (8) is electrically connected to the front camera (45) of the front lens assembly (4) and the horizontal camera (65) of the horizontal lens assembly (6) to display the status of the high-frequency probe (35) on the PCB board. The vector network analyzer (9) is electrically connected to the high-frequency probe (35) to display the TDR curve of the high-speed differential signal channel under test on the PCB board.

9. A method for testing the impedance of high-speed signal lines in an optical module, characterized in that, The impedance of an incoming PCB board is measured using a test device for the high-speed signal line impedance of an optical module as described in any one of claims 1 to 7. The test method includes the following steps: S1. Fix the PCB board on the fixed bracket, adjust the front camera (45) of the front lens assembly (4) and focus on the high-speed pad to be tested on the front of the PCB board, and adjust the horizontal camera (65) of the horizontal lens assembly (6) until the side of the PCB board is displayed on the display (8). S2. Adjust the probe clamp (3) to move the high-frequency probe (35) to the vicinity of the high-speed pad to be tested. The display (8) displays the front and side images. Connect the high-frequency probe (35) to the vector network analyzer (9) through the radio frequency cable. S3. Start the vector network analyzer (9), set the parameters of the sweep frequency signal and run it, fine-tune the high-frequency probe (35) to be directly above the high-speed pad to be tested, observe the side image and slowly operate the probe clamp (3) to make the high-frequency probe (35) fall. When the high-frequency probe (35) is about to contact the high-speed pad to be tested, observe the vector network analyzer (9) until the vector network analyzer (9) displays the TDR curve of the high-speed differential signal channel to be tested. S4. After completing the TDR curve measurement of a high-speed differential signal channel, slowly operate the probe fixture (3) to move the high-frequency probe (35) up within a small range and perform the TDR curve measurement of the next high-speed differential signal channel.

Images