Test and calibration method for active driving chip of glass-based AM display screen

Abstract

The invention relates to the technical field of driving chip test and calibration, in particular to an active driving chip test and calibration method for a glass-based AM display screen, which comprises the following steps of: performing basic electrical characteristic test on an active driving chip and performing display function verification test on the glass-based AM display screen; when the active driving chip is marked to be qualified in the basic electrical test and the glass-based AM display screen is marked to be qualified in the display function test, performing a hierarchical variable test on the active driving chip, and obtaining an external factor linear coefficient, an external factor nonlinear coefficient and a coupling coefficient between external factors; when the active driving chip is marked as qualified grading variable test, standard driving parameters are input into the active driving chip, pixel brightness abnormity identification is carried out on the glass-based AM display screen, and global dynamic calibration operation and local area dynamic calibration operation are carried out according to an abnormity identification result; and the efficiency and the accuracy of the test calibration process of the active driving chip are obviously improved.

Description

Technical Field

[0001] The present invention relates to the technical field of driver chip testing and calibration, in particular to a method for testing and calibrating an active driver chip of a glass-based AM display screen. Background Art

[0002] Chinese patent publication number CN1687906A discloses a method and related apparatus for calibrating inter-chip signal drive parameters. The method includes the following steps: Before chip A and chip B in the same electronic system begin formally exchanging data, chip A emits multiple test signals representing the same logical value at varying signal drive strengths. Chip B interprets the values of these test signals and transmits the interpreted values back to chip A. Chip A can then compare the interpreted values with the values represented by the original test signals to assess which signal drive strengths ensure accurate interpretation by chip B.

[0003] Chinese patent publication number CN118191712A discloses a calibration method and calibration device for a chip tester, including the following steps: performing an overall calibration on the driving values actually output by the driving module at multiple preset points, and obtaining a first error between a first calibration value and a first expected value of the preset point after the overall calibration; if there is a target preset point where the first error is greater than the first set error of the driving module, determining a second calibration value based on the first calibration value of the target preset point and the first error, and performing a secondary local calibration on the driving module based on the second calibration value of the target preset point.

[0004] Existing technologies have many unresolved problems in the testing and calibration of active driver chips for glass-based AM displays. In the basic testing phase, it is difficult to fully consider the differences in chip functional characteristics and application scenarios, which can easily lead to the omission of potential defects, resulting in unqualified chips flowing into subsequent processes; in display function verification, there is a lack of a systematic mechanism for accurate detection of bad pixels and grayscale brightness, making it difficult to ensure the quality of the display image. When dealing with the influence of external factors, there is a lack of quantitative analysis methods for the linear and nonlinear effects of factors such as temperature, stress, power supply ripple, and multi-factor coupling effects, making it impossible to accurately grasp the performance changes of chips in complex environments. In the calibration phase, there is a lack of a dynamic calibration strategy that combines global and local aspects, making it difficult to solve the problem of uneven pixel brightness caused by environmental changes and differences in display area characteristics (such as different threshold voltages between the center and the edge). This results in poor display consistency and low reliability of the display, making it difficult to meet the stringent requirements of high-end application scenarios for display performance and stability. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention aims to provide a method for testing and calibrating an active driver chip of a glass-based AM display, comprising the following steps:

[0006] Step s1: Connect the test equipment, configure the test parameters, perform basic electrical characteristics test on the active driver chip and perform display function verification test on the glass-based AM display;

[0007] Step s2: When the active driver chip is marked as having passed the basic electrical test and the glass-based AM display screen is marked as having passed the display function test, a hierarchical variable test is performed on the active driver chip, wherein the hierarchical variable test includes a linear single variable test, a nonlinear single variable test, and a multivariate coupling test, and the linear coefficient of the external factor, the nonlinear coefficient of the external factor, and the coupling coefficient between the external factors are obtained;

[0008] Step s3: When the active driving chip is marked as having passed the graded variable test, standard driving parameters are input into the active driving chip, pixel brightness anomalies of the glass-based AM display are identified, and global dynamic calibration operations and local area dynamic calibration operations are performed based on the anomaly identification results.

[0009] Furthermore, the process of connecting the test equipment, configuring the test parameters, and performing basic electrical characteristic testing on the active driver chip includes:

[0010] Connect the test equipment to the active driver chip of the glass-based AM display, and determine the various test contents and standard test scenarios of the test equipment based on the functional characteristics and application scenarios of the current series of active driver chips. The test contents include various test indicators of basic electrical characteristics test, display function verification test and graded variable test, and the test indicators include driving voltage, current, clock frequency, signal timing, etc.

[0011] Preset the indicator threshold range corresponding to each test indicator in the basic electrical characteristics test, input each test indicator in the basic electrical characteristics test to the active driver chip through the test equipment under the standard test scenario (standard temperature, zero stress, zero power ripple), collect each test indicator output by the active driver chip, and compare each test indicator output by the active driver chip with the corresponding indicator threshold range;

[0012] If any test indicator is not within the corresponding indicator threshold range, the active drive chip will be marked as failing the basic electrical test; if all test indicators are within the corresponding indicator threshold range, the active drive chip will be marked as passing the basic electrical test.

[0013] Furthermore, the process of performing display function verification testing on glass-based AM displays includes:

[0014] A full white signal is input to the glass-based AM display through the test equipment (directly connected to the display's drive pins, bypassing the motherboard or the entire device's drive circuit to avoid power ripple interference from the driver chip, etc.). The display image of the glass-based AM display is collected, and the displayed image is compared with a preset standard display image to obtain the pixel difference of each pixel in the display image. A pixel difference threshold is preset. If there is a pixel with a pixel difference greater than the pixel difference threshold, the glass-based AM display is marked as a bad pixel and fails the display test.

[0015] If the pixel difference of each pixel point is less than or equal to the pixel difference threshold, the glass-based AM display screen is marked as having passed the bad pixel display test, and the glass-based AM display screen that has passed the bad pixel display test is subjected to a grayscale brightness display test.

[0016] Furthermore, the process of performing the grayscale brightness display test includes:

[0017] Input 8-bit grayscale signal (0 to 255 levels) to the glass-based AM display through the test equipment, switch the grayscale value one by one (such as every 5 or 10 levels), obtain the display brightness of the glass-based AM display at each grayscale value, and calculate the brightness of the glass-based AM display according to the ideal gamma curve. Among them, L max is the full white brightness, Γ is the gamma coefficient, Γ = 2.2, for each grayscale value G, obtain the theoretical brightness L corresponding to each grayscale value G theory (G) Obtain the deviation between the display brightness of the glass-based AM display screen at each grayscale value and the corresponding theoretical brightness, preset a grayscale brightness deviation threshold, and if the deviation is less than the grayscale brightness deviation threshold, mark the glass-based AM display screen as having passed the display function test; if the deviation is greater than or equal to the grayscale brightness deviation threshold, mark the glass-based AM display screen as having failed the display function test.

[0018] Furthermore, the process of performing linear univariate testing to obtain the linear coefficient of the external factor includes:

[0019] Preset standard driving parameters and the variation range of each external factor, select any external factor as a physical field variable in the standard test scenario, the external factors including temperature, stress and power supply ripple, change the physical field variables in the standard test scenario with a uniform gradient within the corresponding variation range, and keep other external factors unchanged to generate a linear single-variable physical field, input test indicators to the active driving chip through the test equipment under the linear single-variable physical field, collect the threshold voltage drift of the active driving chip at different times, obtain the drift upper limit of the active driving chip, compare the threshold voltage drift with the drift upper limit, and if the threshold voltage drift at a certain moment is greater than the drift upper limit, mark the active driving chip as failing the test;

[0020] If the threshold voltage drift at all times is less than or equal to the drift upper limit, linear fitting is performed on the threshold voltage drift and physical field variables at different times to obtain the linear coefficient of the external factor, and a nonlinear single variable test is performed.

[0021] Furthermore, the process of obtaining the linear coefficient of the external factor includes:

[0022] External factor linear coefficients include temperature linear coefficient k T , stress linear coefficient k σ and power supply ripple linear coefficient k V ;

[0023] Temperature linear coefficient k T :

[0024] Control stress σ=0, power ripple ΔV dd = 0, only change the temperature T (such as from -40 ° C to 85 ° C); measure the threshold voltage drift ΔV th As T changes, linear fitting yields: ΔV th =k T (T-T0)+C; where T0 is the standard temperature (e.g., 25°C) and C is a constant term;

[0025] Stress linear coefficient k σ :

[0026] Control T = T0, ΔV dd = 0, apply mechanical stress σ (such as thermal stress generated by a film stress tester or thermal expansion coefficient mismatch), and linearly fit ΔV th ~σ, we get k σ ;

[0027] Power supply ripple linear coefficient k V :

[0028] Control T = T0, σ = 0, and superimpose a sinusoidal ripple ΔV on the power supply. dd (t) = Asin(wt), the threshold voltage fluctuation amplitude is determined according to the threshold voltage drift at different times, and the linear fitting is obtained Where A is the amplitude of the sinusoidal ripple, ΔV th,peak Indicates the peak amplitude of the threshold voltage fluctuation due to power supply ripple.

[0029] Furthermore, the process of performing nonlinear univariate testing to obtain the nonlinear coefficient of the external factor includes:

[0030] In a standard test scenario, any external factor is selected as a physical field variable, and the physical field variable in the standard test scenario is changed with a non-uniform gradient within a corresponding variation range, while other external factors remain unchanged, to generate a nonlinear single-variable physical field. Under the nonlinear single-variable physical field, a test indicator is input to the active drive chip through a test device, and the threshold voltage drift at different times is obtained. The threshold voltage drift is compared with the drift upper limit. If the threshold voltage drift at a certain time is greater than the drift upper limit, the active drive chip is marked as failing the test;

[0031] If the threshold voltage drift at all times is less than or equal to the drift upper limit, a quadratic polynomial fitting is performed on the physical field variables and threshold voltage drift at different times to obtain the nonlinear coefficient of the external factor, and a multi-physics coupling test is performed.

[0032] Furthermore, the external factor linear coefficient includes the temperature nonlinear coefficient k T，T , stress nonlinear coefficient k σ,σ and power supply ripple nonlinear coefficient k V，V ;

[0033] Taking temperature as an example, applying a non-uniform temperature gradient (such as achieving nonlinear temperature changes through a heating stage);

[0034] Fitting with a quadratic polynomial: ΔV th =k T (T-T0)+k T，T (T-T0) 2 , separate k by least squares method T and k T，T ;

[0035] Similarly, the stress nonlinear coefficient k is obtained σ,σ and the power supply ripple nonlinear coefficient k V，V .

[0036] Furthermore, the process of conducting multivariate coupling tests and obtaining the coupling coefficients between external factors includes:

[0037] In a standard test scenario, any two external factors are selected as coupling variables, and several test combinations of the coupling variables are preset. The coupling variables in the standard test scenario are continuously changed according to the several test combinations, while other external factors remain unchanged. A multi-physics coupling field is generated. Under the multi-physics coupling field, test indicators are input to the active driver chip through the test equipment, and the threshold voltage drift under different test combinations is obtained. The threshold voltage drift is compared with the drift upper limit. If the threshold voltage drift at a certain moment is greater than the drift upper limit, the active driver chip is marked as failing the test;

[0038] If the threshold voltage drift at all times is less than or equal to the drift upper limit, the active drive chip is marked as passing the graded variable test, and the coupling coefficient between the external factors is obtained based on the threshold voltage drift under different test combinations.

[0039] Furthermore, the coupling coefficient includes the coupling coefficient k between temperature and stress T，σ , the coupling coefficient k between temperature and power supply ripple T，V The coupling coefficient k between the stress and the power supply ripple σ，V ;

[0040] The process of obtaining the coupling coefficient is illustrated as follows:

[0041] Changing two physical fields (such as temperature T and stress σ) while keeping the third variable constant:

[0042] Several test combinations of preset coupling variables:

[0043] Set the high / low level of T (such as T high 、T low ) and high / low levels of σ (such as σ high , σ low );

[0044] Get four test combinations: (T high ,σ high )、(T high ,σ low )、(T low ,σ high )、(T low ,σ low ), and the threshold voltage drift ΔV corresponding to the four test combinations th (T high ,σ high ),ΔV th (T high ,σ low ),ΔV th (T low ,σ high ) and ΔV th (T low ,σ low );

[0045] The threshold voltage drift ΔV th Decomposed into: ΔV th =k T ΔT+k σ Δσ+k T，σ ΔTΔσ, where ΔT = T high -T low , Δσ=σ high -σ low;

[0046] Solve the linear equations by combining the four test data and get the coupling coefficient:

[0047]

[0048]

[0049] Furthermore, the process of identifying pixel brightness anomalies on the glass-based AM display and performing global dynamic calibration operations and local area dynamic calibration operations based on the anomaly identification results includes:

[0050] Input standard driving parameters to the active driving chip to collect the pixel brightness of the glass-based AM display;

[0051] Preset a standard pixel brightness corresponding to the standard driving parameters, compare the pixel brightness of the glass-based AM display with the standard pixel brightness corresponding to the standard driving parameters, and obtain a pixel brightness deviation;

[0052] A pixel brightness deviation threshold is preset. If the pixel brightness deviation is less than or equal to the pixel brightness deviation threshold, a local area dynamic calibration operation is performed. If the pixel brightness deviation is greater than the pixel brightness deviation threshold, a global dynamic calibration operation is performed.

[0053] Furthermore, the process of performing the global dynamic calibration operation includes:

[0054] Considering the impact of temperature change, power supply ripple, and mechanical stress caused by thermal expansion of the glass substrate on the threshold voltage of the driver chip, the environmental parameters (temperature, stress, and power supply ripple) of the active driver chip are collected by combining the micro sensors (temperature and stress sensors) integrated in the active driver chip with the power supply monitoring module. The environmental parameters are compared with the standard test scenario (standard temperature, zero stress, and zero power supply ripple) to obtain the external factor deviation value, which includes the temperature deviation value ΔT, the stress deviation value Δσ, and the power supply ripple deviation value ΔV dd ;

[0055] The threshold voltage drift is obtained based on the external factor deviation value, the external factor linear coefficient, the external factor nonlinear coefficient and the coupling coefficient between the external factors. The standard driving parameters are compensated and adjusted according to the threshold voltage drift. Since the pixel drive of the AM display depends on the switching characteristics of the TFT transistor, its drain current formula is: (saturation region), where u n , W, L are the intrinsic parameters of the transistor, V GS is the gate-source voltage (i.e. driving voltage), V th is the threshold voltage, so the compensation target of the compensation adjustment process is: when V th Drift to Vth +ΔV th By adjusting V GS , making I D Maintain a constant brightness to prevent the brightness from not meeting the preset requirements, and then perform dynamic calibration operations in the local area.

[0056] Furthermore, the calculation formula for obtaining the threshold voltage drift amount according to the external factor deviation value, the external factor linear coefficient, the external factor nonlinear coefficient and the coupling coefficient is:

[0057] ΔV th =k T ΔT+k σ Δσ+k V ΔV dd +k T，T (ΔT) 2 +k σ,σ (Δσ) 2 +k V，V (ΔV dd ) 2 +k T，σ ΔTΔσ+k T，V ΔTΔV dd +k σ，V ΔσΔV dd .

[0058] Furthermore, the process of performing the local area dynamic calibration operation includes:

[0059] The glass-based AM display is divided into a central area and an edge area (such as the outermost 1 to 3 rows and columns of pixels corresponding to the narrow border), and the edge area is divided into several sub-areas. The pixel brightness of the central area and several sub-areas is obtained to build a pixel brightness model. Among them, L(V) is the pixel brightness corresponding to the current driving voltage V, L max is the maximum brightness, is the nth power of the driving voltage, and the pixel brightness model describes the nonlinear response characteristics of pixel brightness through the S-type function (Sigmoid function);

[0060] The pixel brightness of several sub-areas is compared with the pixel brightness of the central area to obtain the pixel brightness errors of the sub-areas and preset the brightness error upper limit. If the pixel brightness error of the sub-area is greater than the brightness error upper limit, the standard driving parameters of the sub-area are adjusted for secondary compensation based on the pixel brightness model.

[0061] Furthermore, the process of performing secondary compensation adjustment on the standard driving parameters of the sub-region based on the pixel brightness model includes:

[0062] It is known that the driving voltage of the sub-region after the global dynamic calibration operation is V′ GS, then according to the pixel brightness model And the driving voltage of the sub-region after the global dynamic calibration operation is V′ GS , the driving voltage V′ of the sub-region GS Adjusted to:

[0063]

[0064] Among them, n is the steepness parameter of the S-shaped curve (obtained through previous calibration), L target Indicates the pixel brightness in the central area, V cal is the driving voltage of the sub-region after secondary compensation adjustment.

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] 1. Multi-dimensional testing system to improve chip reliability

[0067] Comprehensive layered testing coverage:

[0068] Basic electrical characteristics tests (such as threshold voltage, current and other indicators) are used to ensure that the core functions of the chip meet the standards and avoid early failures caused by manufacturing defects.

[0069] Display function verification testing (full white signal, grayscale brightness testing) is directly related to the actual display effect of the display screen, identifying problems that are visible to the naked eye, such as dead pixels and brightness deviation, in advance, thereby improving product yield.

[0070] Hierarchical variable testing (linear / nonlinear single variable, multi-physics field coupling testing) simulates the chip's response in complex environments such as temperature, stress, and power ripple, quantifies the impact of external factors on threshold voltage drift (such as linear coefficient, nonlinear coefficient, and coupling coefficient), breaks through the limitations of traditional single-environment testing, and ensures the chip's stability under extreme working conditions.

[0071] 2. Precision calibration technology to optimize display uniformity

[0072] Combination of global and local dynamic calibration:

[0073] Global dynamic calibration: Based on the deviation of real-time environmental parameters (such as temperature and power supply fluctuations) from standard scenarios, combined with linear / nonlinear coefficients and coupling coefficients obtained from multi-physics field testing, it dynamically calculates threshold voltage drift and compensates for driver parameters. For example, when the ambient temperature rises and the threshold voltage drops, the drive voltage is automatically adjusted to offset the drift, ensuring consistent brightness across the entire screen.

[0074] Localized calibration addresses threshold voltage differences between the center and edge of a glass-based display due to uneven thermal stress distribution, manufacturing process variations (such as evaporation uniformity), or substrate deformation. The edge is divided into sub-regions and a brightness model is constructed. By comparing the brightness errors in these sub-regions with the center, secondary compensation adjustments (such as independently adjusting the drive voltage in each sub-region) are performed to address regional display defects (such as dark edges and uneven brightness) that traditional global calibration cannot address.

[0075] Data-driven compensation algorithm: Based on the coupling coefficient obtained from multivariate testing, it comprehensively evaluates threshold drift under the combined effects of multiple external factors (such as temperature, stress, power supply ripple, and humidity), making the calibration algorithm more accurate to actual operating scenarios. For example, in high-temperature and high-humidity environments, the compensation amount is calculated using a weighted coupling coefficient, taking into account both temperature-induced changes in semiconductor characteristics and humidity-induced substrate expansion stress, thereby improving calibration accuracy.

[0076] Calibration parameter reusability: The linear / nonlinear coefficients and coupling coefficients obtained from testing can be stored as chip characteristic parameters, enabling rapid calibration of products within the same batch or category, reducing repetitive testing workload. For example, glass-based displays on the same production line can share calibration models, improving mass production efficiency.

[0077] 3. Adapt to glass-based characteristics and break through technical bottlenecks

[0078] Glass substrates have a lower coefficient of thermal expansion than flexible substrates (such as PI), but stress concentration at the edges due to cutting and packaging can lead to localized threshold voltage drift. Regional calibration can specifically address stress sensitivity in glass substrates and improve display uniformity, something that is difficult to achieve with traditional flexible screen calibration methods.

[0079] Multi-physics field coupling testing covers the response of glass substrates under high-temperature processes (such as annealing) and mechanical stress (such as cutting), exposing potential defects in advance and optimizing the process compatibility of glass-based AM displays. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1 This is a schematic diagram of a method for testing and calibrating an active driver chip of a glass-based AM display screen according to an embodiment of the present application. DETAILED DESCRIPTION

[0081] The following is a clear and complete description of the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts are within the scope of protection of this application.

[0082] like Figure 1As shown, the active driver chip test and calibration method of the glass-based AM display includes the following steps:

[0083] Step s1: Connect the test equipment, configure the test parameters, perform basic electrical characteristics test on the active driver chip and perform display function verification test on the glass-based AM display;

[0084] Step s2: When the active driver chip is marked as having passed the basic electrical test and the glass-based AM display screen is marked as having passed the display function test, a hierarchical variable test is performed on the active driver chip, wherein the hierarchical variable test includes a linear single variable test, a nonlinear single variable test, and a multivariate coupling test, and the linear coefficient of the external factor, the nonlinear coefficient of the external factor, and the coupling coefficient between the external factors are obtained;

[0085] Step s3: When the active driving chip is marked as having passed the graded variable test, standard driving parameters are input into the active driving chip, pixel brightness anomalies of the glass-based AM display are identified, and global dynamic calibration operations and local area dynamic calibration operations are performed based on the anomaly identification results.

[0086] It should be further explained that, in the specific implementation process, the process of connecting the test equipment, configuring the test parameters, and performing basic electrical characteristics testing on the active driver chip includes:

[0087] Connect the test equipment to the active driver chip of the glass-based AM display, and determine the various test contents and standard test scenarios of the test equipment based on the functional characteristics and application scenarios of the current series of active driver chips. The test contents include various test indicators of basic electrical characteristics test, display function verification test and graded variable test, and the test indicators include driving voltage, current, clock frequency, signal timing, etc.

[0088] Preset the indicator threshold range corresponding to each test indicator in the basic electrical characteristics test, input each test indicator in the basic electrical characteristics test to the active driver chip through the test equipment under the standard test scenario (standard temperature, zero stress, zero power ripple), collect each test indicator output by the active driver chip, and compare each test indicator output by the active driver chip with the corresponding indicator threshold range;

[0089] If any test indicator is not within the corresponding indicator threshold range, the active drive chip will be marked as failing the basic electrical test; if all test indicators are within the corresponding indicator threshold range, the active drive chip will be marked as passing the basic electrical test.

[0090] It should be further explained that, in the specific implementation process, the process of performing display function verification testing on glass-based AM display screens includes:

[0091] A full white signal is input to the glass-based AM display through the test equipment (directly connected to the display's drive pins, bypassing the motherboard or the entire device's drive circuit to avoid power ripple interference from the driver chip, etc.). The display image of the glass-based AM display is collected, and the displayed image is compared with a preset standard display image to obtain the pixel difference of each pixel in the display image. A pixel difference threshold is preset. If there is a pixel with a pixel difference greater than the pixel difference threshold, the glass-based AM display is marked as a bad pixel and fails the display test.

[0092] If the pixel difference of each pixel point is less than or equal to the pixel difference threshold, the glass-based AM display screen is marked as having passed the bad pixel display test, and the glass-based AM display screen that has passed the bad pixel display test is subjected to a grayscale brightness display test.

[0093] It should be further explained that, in the specific implementation process, the process of grayscale brightness display test includes:

[0094] Input 8-bit grayscale signal (0 to 255 levels) to the glass-based AM display through the test equipment, switch the grayscale value one by one (such as every 5 or 10 levels), obtain the display brightness of the glass-based AM display at each grayscale value, and calculate the brightness of the glass-based AM display according to the ideal gamma curve. Among them, L max is the full white brightness, Γ is the gamma coefficient, Γ = 2.2, for each grayscale value G, obtain the theoretical brightness L corresponding to each grayscale value G theory (G) Obtain the deviation between the display brightness of the glass-based AM display screen at each grayscale value and the corresponding theoretical brightness, preset a grayscale brightness deviation threshold, and if the deviation is less than the grayscale brightness deviation threshold, mark the glass-based AM display screen as having passed the display function test; if the deviation is greater than or equal to the grayscale brightness deviation threshold, mark the glass-based AM display screen as having failed the display function test.

[0095] It should be further explained that, in the specific implementation process, the process of performing linear single variable testing and obtaining the linear coefficient of the external factor includes:

[0096] Preset standard driving parameters and the variation range of each external factor, select any external factor as a physical field variable in the standard test scenario, the external factors including temperature, stress and power supply ripple, change the physical field variables in the standard test scenario with a uniform gradient within the corresponding variation range, and keep other external factors unchanged to generate a linear single-variable physical field, input test indicators to the active driving chip through the test equipment under the linear single-variable physical field, collect the threshold voltage drift of the active driving chip at different times, obtain the drift upper limit of the active driving chip, compare the threshold voltage drift with the drift upper limit, and if the threshold voltage drift at a certain moment is greater than the drift upper limit, mark the active driving chip as failing the test;

[0097] If the threshold voltage drift at all times is less than or equal to the drift upper limit, linear fitting is performed on the threshold voltage drift and physical field variables at different times to obtain the linear coefficient of the external factor, and a nonlinear single variable test is performed.

[0098] It should be further explained that, in the specific implementation process, the process of obtaining the linear coefficient of the external factor includes:

[0099] External factor linear coefficients include temperature linear coefficient k T , stress linear coefficient k σ and power supply ripple linear coefficient k V ;

[0100] Temperature linear coefficient k T :

[0101] Control stress σ=0, power ripple ΔV dd = 0, only change the temperature T (such as from -40 ° C to 85 ° C); measure the threshold voltage drift ΔV th As T changes, linear fitting yields: ΔV th =k T (T-T0)+C; where T0 is the standard temperature (e.g., 25°C) and C is a constant term;

[0102] Stress linear coefficient k σ :

[0103] Control T = T0, ΔV dd = 0, apply mechanical stress σ (such as thermal stress generated by a film stress tester or thermal expansion coefficient mismatch), and linearly fit ΔV th ~σ, we get k σ ;

[0104] Power supply ripple linear coefficient k V :

[0105] Control T = T0, σ = 0, and superimpose a sinusoidal ripple ΔV on the power supply. dd (t) = Asin(wt), the threshold voltage fluctuation amplitude is determined according to the threshold voltage drift at different times, and the linear fitting is obtained Where A is the amplitude of the sinusoidal ripple, ΔV th,peak Indicates the peak amplitude of the threshold voltage fluctuation due to power supply ripple.

[0106] It should be further explained that, in the specific implementation process, the process of conducting nonlinear single variable testing and obtaining the nonlinear coefficient of the external factor includes:

[0107] In a standard test scenario, any external factor is selected as a physical field variable, and the physical field variable in the standard test scenario is changed with a non-uniform gradient within a corresponding variation range, while other external factors remain unchanged, to generate a nonlinear single-variable physical field. Under the nonlinear single-variable physical field, a test indicator is input to the active drive chip through a test device, and the threshold voltage drift at different times is obtained. The threshold voltage drift is compared with the drift upper limit. If the threshold voltage drift at a certain time is greater than the drift upper limit, the active drive chip is marked as failing the test;

[0108] If the threshold voltage drift at all times is less than or equal to the drift upper limit, a quadratic polynomial fitting is performed on the physical field variables and threshold voltage drift at different times to obtain the nonlinear coefficient of the external factor, and a multi-physics coupling test is performed.

[0109] It should be further explained that, in the specific implementation process, the linear coefficient of the external factor includes the temperature nonlinear coefficient k T，T , stress nonlinear coefficient k σ,σ and the power supply ripple nonlinear coefficient k V，V ;

[0110] Taking temperature as an example, applying a non-uniform temperature gradient (such as achieving nonlinear temperature changes through a heating stage);

[0111] Fitting with a quadratic polynomial: ΔV th =k T (T-T0)+k T，T (T-T0) 2 , separate k by least squares method T and k T，T ;

[0112] Similarly, the stress nonlinear coefficient k is obtained σ,σ and the power supply ripple nonlinear coefficient k V，V .

[0113] It should be further explained that, in the specific implementation process, the process of conducting multivariable coupling testing and obtaining the coupling coefficients between external factors includes:

[0114] In a standard test scenario, any two external factors are selected as coupling variables, and several test combinations of the coupling variables are preset. The coupling variables in the standard test scenario are continuously changed according to the several test combinations, while other external factors remain unchanged. A multi-physics coupling field is generated. Under the multi-physics coupling field, test indicators are input to the active driver chip through the test equipment, and the threshold voltage drift under different test combinations is obtained. The threshold voltage drift is compared with the drift upper limit. If the threshold voltage drift at a certain moment is greater than the drift upper limit, the active driver chip is marked as failing the test;

[0115] If the threshold voltage drift at all times is less than or equal to the drift upper limit, the active drive chip is marked as passing the graded variable test, and the coupling coefficient between the external factors is obtained based on the threshold voltage drift under different test combinations.

[0116] It should be further explained that, in the specific implementation process, the coupling coefficient includes the coupling coefficient k between temperature and stress. T，σ , the coupling coefficient k between temperature and power supply ripple T，V The coupling coefficient k between the stress and the power supply ripple σ，V ;

[0117] The process of obtaining the coupling coefficient is illustrated as follows:

[0118] Changing two physical fields (such as temperature T and stress σ) while keeping the third variable constant:

[0119] Several test combinations of preset coupling variables:

[0120] Set the high / low level of T (such as T high 、T low ) and high / low levels of σ (such as σ high , σ low );

[0121] Get four test combinations: (T high ,σ high )、(T high ,σ low )、(T low ,σ high )、(T low ,σ low ), and the threshold voltage drift ΔV corresponding to the four test combinations th (T high ,σ high ),ΔV th (T high ,σ low ),ΔV th (T low ,σ high ) and ΔV th (T low ,σ low );

[0122] The threshold voltage drift ΔV th Decomposed into: ΔV th =k T ΔT+k σ Δσ+k T，σ ΔTΔσ, where ΔT = T high -T low , Δσ=σ high-σ low ;

[0123] Solve the linear equations by combining the four test data and get the coupling coefficient:

[0124]

[0125] It should be further explained that, in a specific implementation process, the process of identifying pixel brightness anomalies on a glass-based AM display and performing global dynamic calibration operations and local area dynamic calibration operations based on the anomaly identification results includes:

[0126] Input standard driving parameters to the active driving chip to collect the pixel brightness of the glass-based AM display;

[0127] Preset a standard pixel brightness corresponding to the standard driving parameters, compare the pixel brightness of the glass-based AM display with the standard pixel brightness corresponding to the standard driving parameters, and obtain a pixel brightness deviation;

[0128] A pixel brightness deviation threshold is preset. If the pixel brightness deviation is less than or equal to the pixel brightness deviation threshold, a local area dynamic calibration operation is performed. If the pixel brightness deviation is greater than the pixel brightness deviation threshold, a global dynamic calibration operation is performed.

[0129] It should be further explained that, in the specific implementation process, the process of performing the global dynamic calibration operation includes:

[0130] Considering the impact of temperature change, power supply ripple, and mechanical stress caused by thermal expansion of the glass substrate on the threshold voltage of the driver chip, the environmental parameters (temperature, stress, and power supply ripple) of the active driver chip are collected by combining the micro sensors (temperature and stress sensors) integrated in the active driver chip with the power supply monitoring module. The environmental parameters are compared with the standard test scenario (standard temperature, zero stress, and zero power supply ripple) to obtain the external factor deviation value, which includes the temperature deviation value ΔT, the stress deviation value Δσ, and the power supply ripple deviation value ΔV dd ;

[0131] The threshold voltage drift is obtained based on the external factor deviation value, the external factor linear coefficient, the external factor nonlinear coefficient and the coupling coefficient between the external factors. The standard driving parameters are compensated and adjusted according to the threshold voltage drift. Since the pixel drive of the AM display depends on the switching characteristics of the TFT transistor, its drain current formula is: (saturation region), where u n , W, L are the intrinsic parameters of the transistor, V GS is the gate-source voltage (i.e. driving voltage), V th is the threshold voltage, so the compensation target of the compensation adjustment process is: when V th Drift to Vth +ΔV th By adjusting V GS , making I D Maintain a constant brightness to prevent the brightness from not meeting the preset requirements, and then perform dynamic calibration operations in the local area.

[0132] It should be further explained that, in a specific implementation process, the calculation formula for obtaining the threshold voltage drift amount according to the external factor deviation value, the external factor linear coefficient, the external factor nonlinear coefficient and the coupling coefficient is:

[0133] ΔV th =k T ΔT+k σ Δσ+k V ΔV dd +k T，T (ΔT) 2 +k σ,σ (Δσ) 2 +

[0134] k V，V (ΔV dd ) 2 +k T，σ ΔTΔσ+k T，V ΔTΔV dd +k σ，V ΔσΔV dd .

[0135] It should be further explained that, in the specific implementation process, the process of performing the local area dynamic calibration operation includes:

[0136] The glass-based AM display is divided into a central area and an edge area (such as the outermost 1 to 3 rows and columns of pixels corresponding to the narrow border), and the edge area is divided into several sub-areas. The pixel brightness of the central area and several sub-areas is obtained to build a pixel brightness model. Among them, L(V) is the pixel brightness corresponding to the current driving voltage V, L max is the maximum brightness, is the nth power of the driving voltage, and the pixel brightness model describes the nonlinear response characteristics of pixel brightness through the S-type function (Sigmoid function);

[0137] The pixel brightness of several sub-areas is compared with the pixel brightness of the central area to obtain the pixel brightness errors of the sub-areas and preset the brightness error upper limit. If the pixel brightness error of the sub-area is greater than the brightness error upper limit, the standard driving parameters of the sub-area are adjusted for secondary compensation based on the pixel brightness model.

[0138] It should be further explained that, in a specific implementation process, the process of performing secondary compensation adjustment on the standard driving parameters of the sub-region based on the pixel brightness model includes:

[0139] It is known that the driving voltage of the sub-region after the global dynamic calibration operation is V′ GS , then according to the pixel brightness model And the driving voltage of the sub-region after the global dynamic calibration operation is V′ GS , the driving voltage V′ of the sub-region GS Adjusted to:

[0140]

[0141] Among them, n is the steepness parameter of the S-shaped curve (obtained through previous calibration), L target Indicates the pixel brightness in the central area, V cal is the driving voltage of the sub-region after secondary compensation adjustment.

[0142] This embodiment solves chip-level basic drift (such as the general offset of threshold voltage caused by overall temperature increase and the change of global driving capability caused by power supply fluctuation) through global dynamic calibration operation. At the same time, it solves the threshold voltage difference between the center and edge areas of the glass-based AM display due to manufacturing process uniformity, physical structure differences, etc. through local area dynamic calibration operation. By combining the two, a two-layer compensation system of "global physical field coupling + local spatial refinement" is constructed, which not only meets the driving accuracy requirements in multi-physical field coupling scenarios, but also solves the regional deviation caused by the manufacturing process uniformity of the display scale, and ultimately achieves a uniform display effect across the entire screen.

[0143] The above embodiments are only used to illustrate the technical method of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical method of the present invention.

Claims

1. A method for testing and calibrating an active driver chip for a glass-based AM display, characterized in that: The following steps are involved: Step s1: Connect the test equipment, configure the test parameters, perform basic electrical characteristics test on the active driver chip and perform display function verification test on the glass-based AM display; Step s2: When the active driver chip is marked as having passed the basic electrical test and the glass-based AM display screen is marked as having passed the display function test, a hierarchical variable test is performed on the active driver chip, wherein the hierarchical variable test includes a linear single variable test, a nonlinear single variable test, and a multivariate coupling test, and the linear coefficient of the external factor, the nonlinear coefficient of the external factor, and the coupling coefficient between the external factors are obtained; Step s3: When the active driving chip is marked as having passed the graded variable test, standard driving parameters are input into the active driving chip, pixel brightness anomalies of the glass-based AM display are identified, and global dynamic calibration operations and local area dynamic calibration operations are performed based on the anomaly identification results.

2. The method for testing and calibrating the active driver chip of a glass-based AM display according to claim 1, characterized in that: The process of connecting the test equipment, configuring the test parameters, and performing basic electrical characteristic tests on the active driver chip includes: Connect the test equipment to the active driver chip of the glass-based AM display, and determine the various test contents and standard test scenarios of the test equipment based on the functional characteristics and application scenarios of the current series of active driver chips. The test contents include various test indicators of basic electrical characteristics test, display function verification test and graded variable test; Preset the indicator threshold range corresponding to each test indicator in the basic electrical characteristics test, input each test indicator in the basic electrical characteristics test to the active driver chip through the test equipment under the standard test scenario, collect each test indicator output by the active driver chip, and compare each test indicator output by the active driver chip with the corresponding indicator threshold range; If any test indicator is not within the corresponding indicator threshold range, the active drive chip will be marked as failing the basic electrical test; if all test indicators are within the corresponding indicator threshold range, the active drive chip will be marked as passing the basic electrical test.

3. The method for testing and calibrating the active driver chip of a glass-based AM display according to claim 2, characterized in that: The process of performing display function verification testing on glass-based AM displays includes: A full white signal is input to the glass-based AM display through the test equipment, and the display image of the glass-based AM display is collected. The displayed image is compared with a preset standard display image, and the pixel difference value of each pixel in the display image is obtained. A pixel difference threshold is preset. If there is a pixel whose pixel difference value is greater than the pixel difference threshold, the glass-based AM display is marked as a bad pixel and fails the display test; If the pixel difference of each pixel point is less than or equal to the pixel difference threshold, the glass-based AM display screen is marked as having passed the bad pixel display test, and the glass-based AM display screen that has passed the bad pixel display test is subjected to a grayscale brightness display test.

4. The method for testing and calibrating the active driver chip of a glass-based AM display according to claim 3, characterized in that: The process of performing grayscale brightness display testing includes: An 8-bit grayscale signal is input to the glass-based AM display screen through the test equipment, and the grayscale value is switched successively to obtain the display brightness of the glass-based AM display screen at each grayscale value, obtain the theoretical brightness corresponding to each grayscale value, obtain the deviation between the display brightness of the glass-based AM display screen at each grayscale value and the corresponding theoretical brightness, and preset a grayscale brightness deviation threshold. If the deviation is less than the grayscale brightness deviation threshold, the glass-based AM display screen is marked as having passed the display function test; if the deviation is greater than or equal to the grayscale brightness deviation threshold, the glass-based AM display screen is marked as having failed the display function test.

5. The method for testing and calibrating the active driver chip of a glass-based AM display according to claim 4, characterized in that: The process of performing a linear univariate test to obtain the linear coefficient of the external factor includes: Preset standard driving parameters and the variation range of each external factor, select any external factor as a physical field variable in the standard test scenario, the external factors including temperature, stress and power supply ripple, change the physical field variables in the standard test scenario with a uniform gradient within the corresponding variation range, and keep other external factors unchanged to generate a linear single-variable physical field, input test indicators to the active driving chip through the test equipment under the linear single-variable physical field, collect the threshold voltage drift of the active driving chip at different times, obtain the drift upper limit of the active driving chip, compare the threshold voltage drift with the drift upper limit, and if the threshold voltage drift at a certain moment is greater than the drift upper limit, mark the active driving chip as failing the test; If the threshold voltage drift at all times is less than or equal to the drift upper limit, linear fitting is performed on the threshold voltage drift and physical field variables at different times to obtain the linear coefficient of the external factor, and a nonlinear single variable test is performed.

6. The method for testing and calibrating the active driver chip of a glass-based AM display according to claim 5, characterized in that: The process of performing nonlinear univariate testing to obtain the nonlinear coefficients of external factors includes: In a standard test scenario, any external factor is selected as a physical field variable, and the physical field variable in the standard test scenario is changed with a non-uniform gradient within a corresponding variation range, while other external factors remain unchanged, to generate a nonlinear single-variable physical field. Under the nonlinear single-variable physical field, a test indicator is input to the active drive chip through a test device, and the threshold voltage drift at different times is obtained. The threshold voltage drift is compared with the drift upper limit. If the threshold voltage drift at a certain time is greater than the drift upper limit, the active drive chip is marked as failing the test; If the threshold voltage drift at all times is less than or equal to the drift upper limit, a quadratic polynomial fitting is performed on the physical field variables and threshold voltage drift at different times to obtain the nonlinear coefficient of the external factor, and a multi-physics coupling test is performed.

7. The method for testing and calibrating the active driver chip of a glass-based AM display according to claim 6, characterized in that: The process of conducting multivariate coupling tests and obtaining the coupling coefficients between external factors includes: In a standard test scenario, any two external factors are selected as coupling variables, and several test combinations of the coupling variables are preset. The coupling variables in the standard test scenario are continuously changed according to the several test combinations, while other external factors remain unchanged. A multi-physics coupling field is generated. Under the multi-physics coupling field, test indicators are input to the active driver chip through the test equipment, and the threshold voltage drift under different test combinations is obtained. The threshold voltage drift is compared with the drift upper limit. If the threshold voltage drift at a certain moment is greater than the drift upper limit, the active driver chip is marked as failing the test; If the threshold voltage drift at all times is less than or equal to the drift upper limit, the active drive chip is marked as passing the graded variable test, and the coupling coefficient between the external factors is obtained based on the threshold voltage drift under different test combinations.

8. The method for testing and calibrating the active driver chip of a glass-based AM display according to claim 7, characterized in that: The process of identifying pixel brightness anomalies on a glass-based AM display and performing global dynamic calibration operations and local area dynamic calibration operations based on the anomaly identification results includes: Input standard driving parameters to the active driving chip to collect the pixel brightness of the glass-based AM display; Preset a standard pixel brightness corresponding to the standard driving parameters, compare the pixel brightness of the glass-based AM display with the standard pixel brightness corresponding to the standard driving parameters, and obtain a pixel brightness deviation; A pixel brightness deviation threshold is preset. If the pixel brightness deviation is less than or equal to the pixel brightness deviation threshold, a local area dynamic calibration operation is performed. If the pixel brightness deviation is greater than the pixel brightness deviation threshold, a global dynamic calibration operation is performed.

9. The method for testing and calibrating the active driver chip of a glass-based AM display according to claim 8, characterized in that: The process of performing a global dynamic calibration operation includes: Collect the environmental parameters of the active drive chip, compare the environmental parameters with the standard test scenario, and obtain the external factor deviation value; The threshold voltage drift is obtained according to the external factor deviation value, the external factor linear coefficient, the external factor nonlinear coefficient and the coupling coefficient between the external factors. The standard driving parameters are compensated and adjusted according to the threshold voltage drift, and then a local area dynamic calibration operation is performed.

10. The method for testing and calibrating the active driver chip of a glass-based AM display according to claim 9, characterized in that: The process of performing a local area dynamic calibration operation includes: The glass-based AM display is divided into a central area and an edge area, and the edge area is divided into several sub-areas. The pixel brightness of the central area and several sub-areas is obtained to construct a pixel brightness model. The pixel brightness of several sub-areas is compared with the pixel brightness of the central area to obtain the pixel brightness errors of the sub-areas and preset the brightness error upper limit. If the pixel brightness error of the sub-area is greater than the brightness error upper limit, the standard driving parameters of the sub-area are adjusted for secondary compensation based on the pixel brightness model.

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