A general automatic test system and method for silicon gyro chip

Abstract

This invention provides a universal automated testing system and method for silicon photonic gyroscope chips. The system includes a chip carrier platform, a chip identification unit, a visual positioning unit, an optical coupling component, a parameter testing component, a temperature control component, and a controller. The controller retrieves the corresponding test configuration based on the chip type identifier. The visual positioning unit acquires the actual coordinates of at least two chip reference markers. Based on this, the controller establishes a transformation relationship between the chip design coordinate system and the test platform coordinate system, and determines the coordinates of each optical port in the test platform coordinate system. The input coupling head and output coupling head, combined with the output optical power, determine the coupling position of each optical port. During temperature testing, after the current temperature point reaches a stable condition, the coupling position of the reference optical port is re-determined, and the remaining optical ports are corrected based on their coordinate offset. This invention enables the positioning, coupling, parameter testing, and result recording of silicon photonic gyroscope chips of different specifications on the same test platform.

Description

Technical Field

[0001] This invention relates to the field of silicon photonics chip testing technology, and in particular to a universal automatic testing system and method for silicon photonics gyroscope chips. Background Technology

[0002] After silicon photonics gyroscope chips are manufactured or packaged, the optical ports on the chip are typically connected to the test optical path before parameters such as insertion loss, extinction ratio, wavelength response, and polarization-dependent loss are measured. When temperature performance needs to be examined, port coupling and parameter acquisition must be repeated at multiple temperature points. Different chip models have different external dimensions, reference positions, number of ports, and port arrangements. After a chip is replaced, the clamping position, port coordinates, and test channels often need to be adjusted accordingly. Therefore, when multiple specifications of chips share a single test device, whether the test configuration accurately corresponds to the actual port positions directly affects subsequent coupling and parameter measurement.

[0003] Chinese invention patent application CN113960441A discloses an automated testing system, method, electronic device, and storage medium for silicon photonics chips. It uses a moving component to deliver the chip under test (DUT) to the testing position and establishes connections between the probe card and the optical coupling module, respectively, before acquiring electrical and optical signal test data. This solution integrates chip handling, optoelectronic connection, and data acquisition, reducing some manual operations. However, when the chip model, port distribution, or test items change, the coordinates of each port, test channels, and test conditions still need to be re-matched. A complete solution for switching configurations between chips of different specifications and correcting clamping deviations is not yet provided.

[0004] Chinese invention patent CN110187454B discloses a method and system for optical coupling testing of silicon photonics chips based on a design layout. The method reads the coordinates of test points from the chip design layout and controls the test fiber to move to the corresponding position for coupling testing. Using the design layout can reduce the operation of searching for test ports one by one. However, after the chip is installed in the test platform, there is usually a certain translation and rotation deviation. The design coordinates in the layout cannot directly represent the actual position of the port in the test platform and still need to be corrected according to the current clamping state of the chip. In addition, some existing silicon photonics test platforms are already capable of visual positioning, automatic fiber alignment, and multi-temperature point testing. For the test method that uses port-by-port recalibration after temperature changes, multiple optical ports need to be searched again at each temperature point, and the test time will increase with the number of ports. If the coupling coordinates of the previous temperature point are directly used, the relative displacement between the chip, the chip support structure, and the coupling mechanism may be reflected in the output optical power, making the coupling change mixed with the temperature response of the chip itself. Therefore, although existing automatic testing and layout positioning solutions can complete port finding, optical coupling and parameter acquisition, there are still problems when continuously testing multi-specification silicon photonic gyroscope chips, such as the need to repeatedly set test configurations, inaccurate correspondence between design coordinates and actual port positions, and long time consumption when re-searching all ports after temperature changes. Summary of the Invention

[0005] The technical problem this invention aims to solve is: when multiple silicon photonic gyroscope chips share the same test platform, the test configuration needs to be repeatedly set after switching chip models, the chip design coordinates do not correspond accurately with the actual positions of the optical ports after clamping, and the time-consuming process of re-searching all optical ports one by one during multi-temperature point testing. This invention provides a universal automatic testing system and method for silicon photonic gyroscope chips. By calling the test configuration corresponding to the chip type, converting the coordinates of the optical ports in the test platform coordinate system, and using the coordinate offset of the reference optical port to correct the positions of the remaining optical ports, continuous automatic testing of chips of different specifications can be completed.

[0006] The technical solution of the present invention is implemented as follows: a universal automatic testing system for silicon photonic gyroscope chips, comprising a chip carrier platform, a chip identification unit, a visual positioning unit, an optical coupling component, a parameter testing component, a temperature control component, and a controller; The controller stores test configurations corresponding to different chip type identifiers. The test configurations at least record the design coordinates of the chip reference mark, the design coordinates of each optical port, the correspondence between the optical port and the test channel, the port identifier of the reference optical port, and the temperature point sequence. The chip identification unit, visual positioning unit, optical coupling component, parameter testing component and temperature control component are respectively connected to the controller. After the chip identification unit reads the chip type identifier of the silicon photonic gyroscope chip under test, the controller retrieves the test configuration corresponding to the chip type identifier. The visual positioning unit acquires the actual coordinates of at least two chip reference marks on the silicon photonic gyroscope chip under test. The controller establishes the coordinate transformation relationship between the chip design coordinate system and the test platform coordinate system based on the design coordinates and actual coordinates of the chip reference marks, and converts the design coordinates of each optical port into coordinates in the test platform coordinate system. The optical coupling assembly includes an input coupling head, an output coupling head, and a displacement mechanism that carries the input coupling head and the output coupling head. The input coupling head and the output coupling head are first moved to the vicinity of the corresponding optical port according to the converted coordinates, and then the position is adjusted in combination with the output optical power, thereby determining the coupling position of each optical port; the parameter testing assembly is connected to the optical path of the input coupling head and the output coupling head respectively. The temperature control component is set up corresponding to the chip carrier platform. The optical coupling component first determines the initial coupling position of each optical port at the reference temperature. After entering the temperature test, once the current temperature point reaches the stable condition, the reference optical port is searched again with the coupling position recorded at the previous temperature point as the starting point. The first temperature point is based on the initial coupling position of the reference optical port. The controller obtains the coordinate offset between the current coupling position and the previous coupling position of the reference optical port, and uses the coordinate offset in each motion direction to correct the coordinates of the remaining optical ports in the corresponding motion direction. The parameter testing component then completes the test at the current temperature point.

[0007] Chip adapters are detachably mounted on the chip carrier platform. The chip adapters are provided with a limiting area that defines the placement position of the silicon photonic gyroscope chip under test. They cooperate with the chip carrier platform through a unified positioning reference. Chip adapters of different specifications are installed at the same reference position on the chip carrier platform.

[0008] Each test configuration can also record optical port attributes, test channel switching order, test items, wavelength scanning range, polarization state switching order, stability judgment conditions for each temperature point, position offset threshold, parameter judgment threshold, and chip grading rules.

[0009] During coordinate conversion, the controller obtains the direction of the line connecting at least two chip reference marks in the chip design coordinate system and the test platform coordinate system, determines the plane rotation angle of the chip based on the direction difference between the two lines, and then determines the translation offset by combining the design coordinates and actual coordinates of at least one chip reference mark. The design coordinates of each optical port are converted according to the plane rotation angle and translation offset.

[0010] The coupling position of each optical port can be obtained through two searches. In the first search, the positions of the input coupling head and the output coupling head are changed according to the first search step, and the position with the maximum output optical power is recorded as the candidate position. In the second search, the position with the maximum output optical power is taken as the coupling position of the corresponding optical port.

[0011] The parameter testing component includes a tunable light source, a polarization adjuster, an optical path switcher, and an optical power detector. The tunable light source is connected to the input coupling head via the optical path switcher. The polarization adjuster is positioned on the optical path between the tunable light source and the input coupling head. The output coupling head is connected to the optical power detector via the optical path switcher. The controller changes the output wavelength, polarization state, and test channel according to the test configuration, records the output optical power of the corresponding channel, and obtains the insertion loss, extinction ratio, wavelength response, and polarization-dependent loss.

[0012] After the silicon photonics gyroscope chip under test reaches a certain temperature point, the temperature control component records the chip temperature during the continuous acquisition period. When the difference between the highest and lowest temperatures during this period is not greater than the temperature stability threshold, the controller determines that the current temperature point has reached the stability condition. When the coordinate offset of the reference optical port exceeds the position offset threshold, the offset is no longer used to correct other ports directly. Instead, the coupling position of all optical ports under test is re-determined, and then the parameter test of the current temperature point is performed.

[0013] After each temperature point in the temperature point sequence reaches a stable condition, the optical coupling component takes the previous coupling position as the search starting point and performs a first search on the reference optical port according to the first search step size, and records the position with the largest output optical power in the first search as the candidate position; then, with the candidate position as the center, a second search is performed according to the second search step size, and the position with the largest output optical power in the second search is taken as the current coupling position of the reference optical port.

[0014] The reference optical port is selected from optical ports that can generate effective output optical power at a reference temperature, and the design coordinates of the reference optical port are closest to the geometric center of the design coordinates of each optical port, wherein the geometric center is determined according to the design coordinates of each optical port.

[0015] This invention also provides a generalized automatic testing method for silicon photonics gyroscope chips, comprising the following steps: S1. Read the chip type identifier of the silicon photonic gyroscope chip under test, and retrieve the corresponding test configuration. The test configuration contains the design coordinates of the chip reference mark, the design coordinates of each optical port, the correspondence between the optical port and the test channel, the port identifier of the reference optical port, and the temperature point sequence. S2. Collect the actual coordinates of at least two chip reference marks on the silicon optical gyroscope chip under test. Based on the design coordinates and actual coordinates of the chip reference marks, establish the coordinate transformation relationship between the chip design coordinate system and the test platform coordinate system, and convert the design coordinates of each optical port into coordinates in the test platform coordinate system. S3. Move the input coupling head and output coupling head to the vicinity of the corresponding optical port according to the converted coordinates, adjust the position of the input coupling head and output coupling head and synchronously collect the output optical power, determine the initial coupling position of each optical port at the reference temperature according to the output optical power, and complete the parameter test at the reference temperature. S4. Adjust to each temperature point in the temperature point sequence in sequence. After the current temperature point reaches a stable condition, control the optical coupling component to take the coupling position recorded at the previous temperature point as the starting point and redetermine the current coupling position of the reference optical port. The first temperature point takes the initial coupling position as the starting point. Obtain the coordinate offset between the current coupling position of the reference optical port and the previous coupling position. Use the coordinate offset in each motion direction to correct the coordinates of the remaining optical ports in the corresponding motion direction. After the coordinate correction, perform parameter testing at the current temperature point. S5. Summarize the test results of the reference temperature and parameters obtained at each temperature point to form a test record corresponding to the silicon photonic gyroscope chip under test.

[0016] When the coordinate offset of the reference optical port exceeds the position offset threshold, the coupling position of all optical ports under test is redefined, and the parameter test at the current temperature point is performed again. If the coordinate offset does not exceed the position offset threshold, but the test result of a certain parameter exceeds the corresponding parameter judgment threshold, the current temperature and coupling state are kept unchanged, the test item is retested, and a judgment is made based on the retest result.

[0017] After all tests are completed, the test results of each parameter are compared with the parameter judgment thresholds in the test configuration. The chip grade is determined according to the comparison results, and the tested chip is transferred to the corresponding storage area. The chip type identifier, test configuration version, coupling position of each optical port, reference temperature and parameter test results of each temperature point, coordinate offset of the reference optical port and chip grade are uploaded to the manufacturing execution system.

[0018] The embodiments of the present invention have the following advantages due to the adoption of the above technical solutions: I. This invention associates chip type identification with corresponding test configuration. After the chip specification is changed, the controller can directly call the reference mark coordinates, optical port coordinates and test channel relationships of the chip model. Then, the actual coordinates obtained by visual positioning are used to correct the translation and rotation deviations caused by chip clamping, thereby reducing the operation of repeatedly setting port positions and test channels when switching between different chip models.

[0019] Second, in this invention, the input coupling head and the output coupling head first reach the vicinity of the optical port according to the converted coordinates, and then search for the actual coupling position through the output optical power; the first search is used to determine the effective coupling area, and the second search narrows the search range near the candidate position so that the finally recorded coupling position can correspond to the current clamping state of the chip.

[0020] Third, during the temperature test of this invention, it is first determined whether the current temperature point has reached the stable condition, and then the port identifier of the reference optical port is searched again, and the coordinate offset between the two coupling positions is used to correct the remaining ports. When the temperature change causes relative displacement between the chip, chip adapter and coupling mechanism, the port position can be compensated first, and then the parameter data can be collected to reduce the impact of the coupling position change on the test results, and at the same time avoid performing a complete search of all ports at each temperature point.

[0021] Fourth, in this invention, chip identification, optical coupling, parameter testing, temperature testing, anomaly retesting, result judgment, and sorting are all uniformly connected by a controller. Test data is saved in correspondence with chip type identification, coupling position, and temperature point, which facilitates subsequent hierarchical management and data traceability in the manufacturing execution system. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the architecture of the universal automatic testing system for silicon photonic gyroscope chips of the present invention; Figure 2 This is a flowchart illustrating the two searches for the optical port coupling position in this invention. Figure 3 This is a flowchart of the temperature testing and coordinate compensation process of the present invention. Detailed Implementation

[0023] like Figure 1 As shown, this embodiment of the invention provides a universal automated testing system and method for silicon photonics gyroscope chips, used to complete chip identification, optical port positioning, fiber optic coupling, parameter detection, temperature testing, and result recording. Different specifications of silicon photonics gyroscope chips correspond to specific test configurations. After chip replacement, the controller calls the corresponding configuration, eliminating the need to re-enter the chip's design port coordinates and test channel correspondences.

[0024] In this embodiment, the chip design coordinate system refers to the coordinate system determined according to the silicon photonics gyroscope chip design layout. The design coordinates of the chip reference mark and each optical port are recorded in this coordinate system. The test platform coordinate system refers to the coordinate system established with the unified positioning reference of the chip carrier platform as a reference. The actual coordinates of the chip reference mark obtained by the visual positioning unit and the motion coordinates of the input coupling head and the output coupling head are all represented by this coordinate system.

[0025] Example 1 The automated testing system in this embodiment includes a chip platform, a chip identification unit, a visual positioning unit, an optical coupling component, a parameter testing component, a temperature control component, and a controller. The chip identification unit, visual positioning unit, optical coupling component, parameter testing component, and temperature control component are all connected to the controller, which schedules them sequentially according to the test configuration corresponding to the chip under test.

[0026] The chip carrier is located within the testing area of ​​the temperature control component. The chip carrier is equipped with detachable chip adapters. The chip adapters have limiting areas. After the silicon photonic gyroscope chip under test is placed in the limiting areas, its approximate installation position is restricted. Different shapes and specifications of chips are equipped with corresponding chip adapters. Each chip adapter is installed with the same reference position to the chip carrier. When changing the specifications of the chip under test, only the corresponding chip adapter needs to be replaced. The chip carrier, optical coupling component and parameter testing component can still be used.

[0027] The chip identification unit reads the chip type identifier of the chip under test and sends the identification result to the controller; In this embodiment, the chip identification unit can acquire the identification image on the surface of the chip under test through the image acquisition module, and then the identification module can obtain the chip type identification from the identification image. The specific setting of the chip type identification is not limited, as long as it can establish a corresponding relationship with the test configuration stored in the controller.

[0028] The controller stores test configurations corresponding to different chip types. The test configurations record the design coordinates of the chip reference mark, the design coordinates of each optical port, the correspondence between the optical port and the test channel, the port identifier of the reference optical port, and the temperature point sequence. For chips with different test items, the test configurations can also record optical port attributes, test channel switching order, wavelength scanning range, polarization state switching order, temperature stability conditions, position offset threshold, parameter judgment threshold, and chip classification rules.

[0029] The reference optical port is pre-selected from the optical ports of the silicon photonic gyroscope chip under test. It can be an optical port with stable output optical power at the reference temperature and small coupling position deviation obtained by repeated search, or an optical port located in the central area of ​​the optical port arrangement. The port identifier of the selected reference optical port is stored in the corresponding test configuration.

[0030] After the chip is placed, the vision positioning unit acquires an image of the chip surface, identifies at least two chip reference marks from the image, and obtains the actual coordinates of each chip reference mark in the test platform coordinate system. The controller compares the actual coordinates with the design coordinates in the test configuration, and calculates the planar rotation angle after chip placement based on the direction of the line connecting the two chip reference marks in the chip design coordinate system and the test platform coordinate system.

[0031] After determining the plane rotation angle, the coordinates in the chip design coordinate system are first rotated and converted according to the plane rotation angle. Then, based on the coordinate difference between the rotated and converted coordinates of at least one chip reference mark and its actual coordinates, the translational offset of the chip in the test platform coordinate system is obtained. The design coordinates of each optical port are then converted into coordinates in the test platform coordinate system according to the plane rotation angle and translational offset.

[0032] Through the above calculations, the translation and rotation deviations caused by chip clamping are reflected in the position of each optical port. The input coupling head and output coupling head can first reach the vicinity of the corresponding port and then perform a local search, instead of directly using the coordinates in the design layout as the final coupling position.

[0033] The optical coupling assembly includes an input coupling head, an output coupling head, and displacement mechanisms that support both. The input coupling head is connected to the light source side of the parameter testing assembly, and the output coupling head is connected to the detection side of the parameter testing assembly. In this embodiment, the displacement mechanism uses a six-degree-of-freedom adjustment platform, which can change the positions of the input and output coupling heads in three linear directions and their attitudes in three rotational directions, with a repeatability accuracy of ±0.1μm.

[0034] like Figure 2 As shown, during optical coupling, the input coupling head and the output coupling head first move to the vicinity of the corresponding optical port according to the converted coordinates, and then change their positions according to the first search step distance, while simultaneously acquiring the output optical power. After the first search is completed, the position with the largest output optical power in this search is recorded as the candidate position. The second search is limited to the vicinity of the candidate position. The second search step distance is smaller than the first search step distance. The position with the largest output optical power in the second search is taken as the coupling position of the current optical port.

[0035] The first search identifies the region near the port where effective optical power output can be achieved, while the second search further narrows the search area around the candidate locations. After a search for an optical port is completed, the controller records the port number, coupling position, and corresponding output optical power. This record can be retrieved for subsequent parameter and temperature tests.

[0036] For port combinations where both the input and output coupling heads need adjustment, the controller can change their positions sequentially according to the test configuration, using whether the output optical power continues to increase as the basis for adjustment. The specific search order can be determined based on the chip port layout and test optical path settings, without changing the basic process of the two searches mentioned above.

[0037] The parameter testing components include a tunable light source, a polarization adjuster, an optical path switcher, and an optical power detector. The tunable light source is connected to the input coupling head via the optical path switcher. The polarization adjuster is positioned between the tunable light source and the input coupling head. The output coupling head is connected to the optical power detector via the optical path switcher. During testing, the controller switches the output wavelength, polarization state, and test channel according to the current test configuration and records the output optical power of the corresponding channel.

[0038] This embodiment can perform insertion loss, extinction ratio, wavelength response, and polarization-dependent loss tests. The wavelength scanning range covers the C-band and L-band. The test accuracy for insertion loss and polarization-dependent loss is 0.01 dB, and the test accuracy for extinction ratio is 0.1 dB. Each test item is connected to the corresponding channel through an optical path switcher. During the switching process, the chip under test remains in its original clamping state.

[0039] The output wavelength, polarization state, port combination, and test channel required for different test items are all provided by the test configuration. After the controller completes one parameter acquisition, it records the test item, port number, output wavelength, polarization state, and test result accordingly to avoid data confusion between different chip models or different test channels.

[0040] like Figure 3 As shown, after completing the test at the reference temperature, the temperature test begins; the coupling positions of each optical port determined at the reference temperature are recorded as the initial coupling positions, which serve as the starting point for re-searching the reference optical port at the first subsequent temperature point.

[0041] The temperature control component changes the temperature of the chip's carrying area according to the temperature point sequence in the test configuration. The temperature adjustment range is -55℃ to +125℃, and the temperature change rate is not less than 10℃ / min. After reaching the set temperature, the chip temperature is recorded during the continuous acquisition period. When the difference between the highest and lowest temperatures during this period is not greater than the temperature stability threshold in the test configuration, the controller determines that the current temperature point has reached the stability condition, and then starts the optical test at that temperature point.

[0042] When the temperature changes, there may be relative displacement between the chip under test, the chip adapter, and the optical coupling components. The optical ports are concentrated in a millimeter-level area on the silicon photonics gyroscope chip. When the chip clamping state and the positioning relationship of the chip adapter remain unchanged, the port position change caused by the temperature change is mainly manifested as an overall translation, and the relative position change between the optical ports is small. Therefore, the coordinate offset of the reference optical port can be used to correct the coordinates of the other optical ports.

[0043] At each temperature point, the optical coupling component re-searches for the coupling position of the corresponding reference optical port based on the port identifier of the reference optical port recorded in the test configuration; the first temperature point uses the initial coupling position recorded at the reference temperature as the search starting point, and subsequent temperature points use the coupling position recorded at the previous temperature point as the search starting point.

[0044] The re-search of the reference optical port still adopts a two-stage search method. Taking the search starting point as the center, the first search is performed according to the first search step size to obtain the candidate position. Then, taking the candidate position as the center, the second search is performed according to the second search step size. The position with the highest output optical power in the second search is recorded as the coupling position of the reference optical port at the current temperature point.

[0045] The coordinate difference between the coupling position of the reference optical port at the current temperature point and the previous coupling position is recorded as the coordinate offset corresponding to the current temperature change. The coordinate offset is recorded according to the movement direction of the input coupling head and the output coupling head respectively. The controller superimposes the coordinate offset of the corresponding direction to the corresponding coordinates of the other optical ports in the coordinate system of the test platform. The input coupling head and the output coupling head then move according to the corrected coordinates and complete the parameter acquisition of the current temperature point.

[0046] The above processing is mainly used to correct the overall positional offset of each optical port after temperature change. When the coordinate offset of the reference optical port does not exceed the positional offset threshold in the test configuration, the controller uses the coordinate offset to correct the other optical ports. When the coordinate offset exceeds the positional offset threshold, it means that the positional change caused by the current temperature change is no longer suitable to directly use the correction result of the reference optical port. At this time, the coordinates of the other ports are no longer superimposed uniformly. Instead, all optical ports to be tested are searched again, and the parameters of the current temperature point are tested.

[0047] If the coordinate offset of the reference optical port is within the allowable range, but the test result of a certain parameter exceeds the corresponding parameter judgment threshold, then keep the current temperature and coupling state unchanged, and only repeat the test item; if the retest result still exceeds the parameter judgment threshold, the item is recorded as a parameter abnormality and included in the subsequent chip classification.

[0048] After all temperature point tests are completed, the chip type identifier, test configuration version, coupling position of each optical port, reference temperature and temperature data of each temperature point, parameter test results, and coordinate offset of the reference optical port are summarized into a set of test records. When the system is equipped with an automatic sorting mechanism, the chip grade is determined according to the grading rules in the test configuration, and the robot puts the tested chips into the corresponding storage area. The test records are simultaneously uploaded to the manufacturing execution system.

[0049] Example 2 When testing silicon photonic gyroscope chips using the system of Example 1, the chip under test is first placed in a chip adapter that corresponds to its shape and specifications. The chip adapter is installed at a uniform reference position on the chip carrier platform. The chip identification unit reads the chip type identifier, and the controller retrieves the corresponding test configuration accordingly.

[0050] Subsequently, the vision positioning unit acquires images of the chip surface and identifies at least two chip reference marks. The controller first calculates the planar rotation angle based on the direction of the line connecting the chip reference marks in the two coordinate systems, then rotates and converts the design coordinates according to the planar rotation angle, and obtains the translational offset by combining it with the actual coordinates of the chip reference marks. In this way, the design coordinates of each optical port are converted into coordinates in the test platform coordinate system.

[0051] The input and output coupling heads move to the vicinity of the corresponding optical ports according to the converted coordinates. A first search is performed to obtain candidate positions, and a second search is performed around the candidate positions. Finally, the initial coupling positions of each optical port at the reference temperature are recorded. After coupling is completed, the controller switches the test channel, output wavelength and polarization state according to the test configuration to obtain various parameters at the reference temperature.

[0052] The temperature control component adjusts the area where the chip is located to the next temperature point in the temperature point sequence. After the temperature change during the continuous acquisition period meets the stability condition, it begins to search for the port identifier of the reference optical port again. The first temperature point calls the initial coupling position at the reference temperature, and subsequent temperature points call the coupling position recorded at the previous temperature point; the port identifier of the reference optical port is re-determined to determine the current coupling position in the same two-search method as the initial coupling.

[0053] The controller obtains the coordinate offset in each direction of motion based on the coordinate difference between the two coupling positions before and after the port identification of the reference optical port, and corrects the coordinates of the remaining optical ports in the coordinate system of the test platform; after the input coupling head and output coupling head move to the corrected coordinates, the parameter test of the current temperature point is completed.

[0054] When the coordinate offset exceeds the position offset threshold, the coordinate offset of the reference optical port is not used to correct the other ports. Instead, the coupling position of all optical ports under test is re-determined. When the coordinate offset does not exceed the limit but a certain parameter exceeds the parameter judgment threshold, the current temperature and coupling status are retained, and the test item is retested separately.

[0055] After completing all temperature points in the above manner, the test results of the reference temperature and each temperature point are summarized to form a test record for the corresponding chip under test. The test record retains the chip type identifier, test configuration version, port coupling position, temperature data, parameter test results, and coordinate offset of the reference optical port. Then, it is stored in partitions according to chip level, and the relevant data is uploaded to the manufacturing execution system.

[0056] When replacing a silicon photonic gyroscope chip of a different specification, use a chip adapter that matches its shape and retrieve another set of test configurations; visual positioning, coordinate conversion, optical coupling, parameter testing and temperature testing are still completed on the same test platform, without the need to set up complete test equipment for different specifications of chips.

[0057] Test Example: Time Consumption Test for Different Port Position Correction Methods A silicon photonic gyroscope chip with eight optical ports to be tested was selected. Under the same chip clamping state, temperature point sequence, search area, first search step, second search step, and optical power acquisition frequency, port position correction was performed using both the full-port re-search method and the reference optical port compensation method.

[0058] The test temperatures were set sequentially to -40℃, -20℃, 25℃, 60℃, and 85℃. Timing started after each temperature reached a stable condition, and ended when all optical ports completed position calibration. Temperature adjustment time and subsequent parameter acquisition time were not included in the timing.

[0059] The full-port re-search method searches all eight optical ports twice in sequence; the reference optical port compensation method searches only one reference optical port twice, and then corrects the coordinates of the remaining seven optical ports in the test platform coordinate system based on the coordinate offset of the reference optical port relative to the previous temperature point. The test results are shown in Table 1.

[0060] Table 1. Time consumption for different port position correction methods

[0061] As shown in Table 1, when searching each of the eight optical ports one by one, the average position correction time for each temperature point is 53.1s. After adopting the reference optical port compensation method, the average position correction time is 8.7s, which is a reduction of about 83.6%. When the coordinate offset of the reference optical port does not exceed the position offset threshold, only searching the reference optical port and correcting the coordinates of the remaining optical ports can reduce the repeated search process and shorten the port position correction time in temperature testing.

Claims

1. A universal automatic testing system for silicon photonics gyroscope chips, comprising a chip carrier platform, a chip identification unit, a visual positioning unit, an optical coupling assembly, a parameter testing assembly, a temperature control assembly, and a controller, characterized in that, The controller stores test configurations corresponding to different chip type identifiers. The test configurations at least record the design coordinates of the chip reference mark, the design coordinates of each optical port, the correspondence between the optical port and the test channel, the port identifier of the reference optical port, and the temperature point sequence. The chip identification unit, visual positioning unit, optical coupling component, parameter testing component and temperature control component are respectively connected to the controller. After the chip identification unit reads the chip type identifier of the silicon photonic gyroscope chip under test, the controller retrieves the test configuration corresponding to the chip type identifier. The visual positioning unit acquires the actual coordinates of at least two chip reference marks on the silicon photonic gyroscope chip under test. The controller establishes the coordinate transformation relationship between the chip design coordinate system and the test platform coordinate system based on the design coordinates and actual coordinates of the chip reference marks, and converts the design coordinates of each optical port into coordinates in the test platform coordinate system. The optical coupling assembly includes an input coupling head, an output coupling head, and a displacement mechanism that carries the input coupling head and the output coupling head. The input coupling head and the output coupling head are moved to the vicinity of the corresponding optical port according to the converted coordinates. The coupling position of each optical port is determined by adjusting the position and combining it with the output optical power. The parameter testing assembly is connected to the optical path of the input coupling head and the output coupling head respectively. The temperature control component is set on the chip carrier platform. The optical coupling component determines the initial coupling position of each optical port at the reference temperature. After each temperature point in the temperature point sequence reaches the stable condition, the optical coupling component uses the coupling position recorded at the previous temperature point as the starting point to redetermine the current coupling position of the reference optical port. The first temperature point is based on the initial coupling position. The controller obtains the coordinate offset between the current coupling position and the previous coupling position of the reference optical port, and uses the coordinate offset in each motion direction to correct the coordinates of the remaining optical ports in the corresponding motion direction. The parameter testing component obtains the test result of the current temperature point after the coordinate correction.

2. The universal automatic testing system for silicon photonic gyroscope chips according to claim 1, characterized in that, A chip adapter is detachably mounted on the chip carrier platform. The chip adapter has a limiting area that defines the placement position of the silicon photonic gyroscope chip under test, and cooperates with the chip carrier platform through a unified positioning reference. Chip adapters of different specifications adopt the same reference installation position on the chip carrier platform.

3. The universal automatic testing system for silicon photonic gyroscope chips according to claim 1, characterized in that, Each test configuration also records the optical port attributes, test channel switching order, test items, wavelength scanning range, polarization state switching order, stability judgment conditions for each temperature point, parameter judgment thresholds, and chip grading rules.

4. The universal automatic testing system for silicon photonic gyroscope chips according to claim 1, characterized in that, The controller obtains the direction of the connection between the at least two chip reference marks in the chip design coordinate system and the test platform coordinate system, determines the plane rotation angle of the silicon optical gyroscope chip under test based on the direction difference between the two lines, and determines the translation offset by combining the design coordinates and actual coordinates of at least one chip reference mark. The design coordinates of each optical port are converted into coordinates in the test platform coordinate system according to the plane rotation angle and translation offset.

5. The universal automatic testing system for silicon photonic gyroscope chips according to claim 1, characterized in that, The coupling position of each optical port is obtained through two searches. In the first search, the positions of the input coupling head and the output coupling head are changed according to the first search step, and the position with the highest output optical power in the first search is recorded as the candidate position. In the second search, the candidate position is used as the center and the second search step is performed according to the second search step, which is smaller than the first search step. The position with the highest output optical power in the second search is used as the coupling position of the corresponding optical port. After each temperature point in the temperature point sequence reaches a stable condition, the optical coupling component takes the previous coupling position as the search starting point, performs a first search on the reference optical port according to the first search step size, and records the position with the largest output optical power in the first search as the candidate position. Then, with the candidate position as the center, a second search is performed according to the second search step size, and the position with the largest output optical power in the second search is taken as the current coupling position of the reference optical port.

6. The universal automatic testing system for silicon photonic gyroscope chips according to claim 1, characterized in that, The parameter testing component includes a tunable light source, a polarization adjuster, an optical path switcher, and an optical power detector. The tunable light source is connected to the input coupling head via the optical path switcher. The polarization adjuster is positioned in the optical path between the tunable light source and the input coupling head. The output coupling head is connected to the optical power detector via the optical path switcher. The controller changes the output wavelength, polarization state, and test channel according to the test configuration, records the output optical power of the corresponding channel, and obtains the insertion loss, extinction ratio, wavelength response, and polarization-dependent loss.

7. The universal automatic testing system for silicon photonic gyroscope chips according to claim 1, characterized in that, After the silicon photonics gyroscope chip under test reaches a temperature point, the temperature control component records the chip temperature during the continuous acquisition period. When the difference between the highest temperature and the lowest temperature during the continuous acquisition period is not greater than the temperature stability threshold, the controller determines that the current temperature point has reached the stability condition. When the coordinate offset of the current coupling position of the reference optical port relative to the previous coupling position exceeds the position offset threshold, the controller controls the optical coupling component to redetermine the coupling positions of all optical ports under test, and then the parameter testing component performs parameter testing at the current temperature point.

8. The universal automatic testing system for silicon photonic gyroscope chips according to claim 1, characterized in that, The reference optical port is selected from optical ports that can generate effective output optical power at a reference temperature, and the design coordinates of the reference optical port are closest to the geometric center of the design coordinates of each optical port, wherein the geometric center is determined according to the design coordinates of each optical port.

9. A universal automatic testing method for silicon photonics gyroscope chips, characterized in that, Includes the following steps: S1. Read the chip type identifier of the silicon photonic gyroscope chip under test, and retrieve the test configuration corresponding to the chip type identifier. The test configuration contains the design coordinates of the chip reference mark, the design coordinates of each optical port, the correspondence between the optical port and the test channel, the port identifier of the reference optical port, and the temperature point sequence. S2. Collect the actual coordinates of at least two chip reference marks on the silicon optical gyroscope chip under test. Based on the design coordinates and actual coordinates of the chip reference marks, establish the coordinate transformation relationship between the chip design coordinate system and the test platform coordinate system, and convert the design coordinates of each optical port into coordinates in the test platform coordinate system. S3. Move the input coupling head and output coupling head to the vicinity of the corresponding optical port according to the converted coordinates, adjust the position of the input coupling head and output coupling head and synchronously collect the output optical power, determine the initial coupling position of each optical port at the reference temperature according to the output optical power, and complete the parameter test at the reference temperature. S4. Adjust to each temperature point in the temperature point sequence in sequence. After the current temperature point reaches a stable condition, control the optical coupling component to take the coupling position recorded at the previous temperature point as the starting point and redetermine the current coupling position of the reference optical port. The first temperature point takes the initial coupling position as the starting point. Obtain the coordinate offset between the current coupling position of the reference optical port and the previous coupling position. Use the coordinate offset in each motion direction to correct the coordinates of the remaining optical ports in the corresponding motion direction. After the coordinate correction, perform parameter testing at the current temperature point. S5. Summarize the test results of the reference temperature and parameters obtained at each temperature point to form a test record corresponding to the silicon photonic gyroscope chip under test.

10. The universal automatic testing method for silicon photonic gyroscope chips according to claim 9, characterized in that, When the coordinate offset of the current coupling position of the reference optical port relative to the previous coupling position exceeds the preset position offset threshold, the coupling positions of all optical ports under test are redefined, and then the parameter test at the current temperature point is performed. If the coordinate offset does not exceed the position offset threshold, but the parameter test result exceeds the corresponding parameter judgment threshold, keep the current temperature point and the current coupling state unchanged, repeat the test items that exceed the parameter judgment threshold, and determine the judgment result of the test items based on the repeated test results. The test results of each parameter are compared with the parameter judgment threshold in the test configuration. The chip grade is determined according to the comparison results, and the tested silicon photonic gyroscope chip is transferred to the storage area corresponding to the chip grade. The chip type identifier, test configuration version, coupling position of each optical port, reference temperature and parameter test results at each temperature point, coordinate offset of the reference optical port, and chip level are all uploaded to the manufacturing execution system.

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