A method for detecting automotive-grade diodes

Abstract

The present invention relates to the field of diode detection technology, and in particular to a method for detecting automotive-grade diodes, including: obtaining a number of image information of each view of the diode to construct a spatial model of the diode, determining the qualification of the spatial morphology of the diode package based on the overall fit of the spatial model, and determining the qualification of the diode package based on the linear coincidence of the pins; using a multimeter to perform preliminary detection based on the qualified diode package, and determining the minimum dynamic resistance based on the volt-ampere characteristic curve of the diode under the condition that the path is qualified to perform preliminary classification of the diode performance; matching the detection voltage based on the preliminary classification result, and monitoring the temperature of the diode in real time during the detection process to establish a temperature fluctuation curve, and determining the maximum rate of change and the range of change of the temperature based on the temperature fluctuation curve to determine whether to adjust the fluctuation evaluation value to redetermine the performance classification of the diode. The present invention improves the performance detection efficiency of the diode.

Description

Technical Field

[0001] The present invention relates to the technical field of diode detection, and in particular to a method for detecting automotive-grade diodes. Background Art

[0002] As vehicle functions become more complex, higher requirements are placed on the packaging characteristics and electrical performance of semiconductor devices. As a key component in automotive electronic systems, the stability and reliability of the performance of automotive-grade diodes are crucial.

[0003] In automotive electronic systems, a large number of voltage peaks will change continuously due to factors such as vehicle startup, shutdown, and engine operation, which may damage diodes and other electronic devices. Therefore, automotive-grade diodes need to have excellent overvoltage protection capabilities.

[0004] Performance grading testing is an important means to further determine the quality of automotive-grade diodes. On the basis of meeting the minimum requirements, diodes of the same type with better performance will be used in components with higher overvoltage protection requirements to improve the overall protection effect of the diode and the safety performance of the vehicle.

[0005] Chinese Patent Publication No.: CN115291073A discloses a performance detection device for a freewheeling diode, which includes a power supply, a rectifier transistor, a parallel branch, a freewheeling diode to be detected, a processing circuit, and a load circuit; the power supply forms a first path between the transistor and the load circuit, which is used to supply power to the load circuit when the transistor is turned on, so as to generate an excitation current through the first path; the parallel branch is connected in parallel with the freewheeling diode to be detected, which is used to shunt the excitation current; the processing circuit is used to obtain the shunting result and determine the performance parameters of the freewheeling diode to be detected according to the shunting result. The device can detect the performance of the freewheeling diode.

[0006] It can be seen that the performance detection device for the freewheeling diode has the following problems: the invention determines the performance parameters of the freewheeling diode to be detected based on the shunting result, but does not further determine the performance of the diode, so that the performance of the diode cannot be determined, resulting in low performance detection efficiency. Summary of the invention

[0007] To this end, the present invention provides an automotive-grade diode detection method to overcome the problem in the prior art of lack of substantial determination of diode performance, resulting in low efficiency in diode performance detection.

[0008] To achieve the above object, the present invention provides a method for detecting an automotive-grade diode, comprising:

[0009] Acquire multiple image information of multiple views of the diode, construct a spatial model of the diode based on the image information, determine the eligibility of the spatial form of the diode package based on the overall fit between the spatial model and the standard model, and determine the eligibility of the diode package based on the linear coincidence of the pins of the spatial model, wherein the standard model is a spatial model of the diode that fully meets the design requirements, and wherein the multiple views are six views of the diode;

[0010] Use a multimeter to conduct a preliminary test on the qualified packaged diode to determine whether the path of the qualified packaged diode is qualified;

[0011] Acquiring a volt-ampere characteristic curve of a diode under a qualified path condition, and determining a minimum dynamic resistance of the diode based on the volt-ampere characteristic curve to preliminarily grade the performance of the diode;

[0012] Matching the fluctuation evaluation value of the detection voltage based on the preliminary classification result to provide the diode with a detection voltage corresponding to the fluctuation evaluation value, monitoring the temperature of the diode in real time during the detection process to establish a temperature fluctuation curve, and determining the maximum change rate and change range of the temperature based on the temperature fluctuation curve;

[0013] Whether to adjust the fluctuation evaluation value to determine the performance grade of the diode is determined based on the maximum change rate and the change range.

[0014] Furthermore, the process of determining the overall fit between the spatial model and the standard model based on the image information includes:

[0015] After preprocessing the image information of any view, feature extraction is performed, and the extracted features are input into a three-dimensional modeling software to construct a spatial model of the diode;

[0016] Performing fitting using the positions corresponding to the spatial model and the standard model as reference points to determine the degrees of fit;

[0017] The maximum value among the above-mentioned fitting degrees is determined as the overall fitting degree, and the fitting base point corresponding to the overall fitting degree is determined.

[0018] Furthermore, the process of determining the eligibility of the spatial form based on the overall fit includes:

[0019] comparing the overall fitness with a preset fitness;

[0020] The spatial form is determined to be qualified based on the comparison result that the overall fit is greater than or equal to the preset fit.

[0021] Furthermore, the process of determining the linear coincidence of the pins based on the qualified spatial form includes:

[0022] Overlapping the pins in the space model with the pins in the standard model based on the fitting base point;

[0023] determining a number of offset distances of the non-coincident positions to calculate the offset variance;

[0024] The offset variance is determined as the straight line coincidence.

[0025] Further, the process of determining whether the diode package is qualified based on the straight line coincidence degree includes:

[0026] Comparing the straight line coincidence with a preset coincidence;

[0027] The diode package is determined to be qualified based on the comparison result that the straight line overlap is less than or equal to the preset overlap.

[0028] Furthermore, under the condition that the diode packaging is qualified, a multimeter is used to determine the diode with a qualified path to determine the minimum dynamic resistance of the diode. The process of preliminarily grading the performance of the diode based on the minimum dynamic resistance includes:

[0029] Comparing the minimum dynamic resistance with the first preset resistance and the second preset resistance respectively;

[0030] Determining that the performance of the diode is first-level performance based on a comparison result that the minimum dynamic resistance is less than or equal to the first preset resistance;

[0031] Determining that the performance of the diode is a secondary performance based on a comparison result that the minimum dynamic resistance is greater than the first preset resistance and less than or equal to the second preset resistance;

[0032] The performance of the diode is determined to be a third-level performance based on the comparison result that the minimum dynamic resistance is greater than the second preset resistance.

[0033] Further, the process of determining the maximum rate of change and range of change of temperature based on the performance grading result of the diode includes:

[0034] Matching a corresponding fluctuation evaluation value for the diode based on the performance grading result, and providing a corresponding detection voltage for the diode based on the fluctuation evaluation value for performance detection;

[0035] The temperature of the diode is monitored in real time to establish a temperature fluctuation curve, and the maximum temperature, the minimum temperature and the maximum change rate are determined based on the temperature fluctuation curve, and the difference between the maximum temperature and the minimum temperature is determined as the change range.

[0036] Further, the process of determining whether to adjust the fluctuation evaluation value based on the maximum change rate and the change range includes:

[0037] Comparing the maximum change rate with a preset change rate, and comparing the change range with a preset range;

[0038] Determining to increase the fluctuation evaluation value based on a comparison result that the maximum change rate is greater than the preset change rate and the change range is greater than the preset range;

[0039] The fluctuation evaluation value is reduced based on a comparison result that the maximum change rate is smaller than the preset change rate and the change range is smaller than the preset range.

[0040] Further, under the condition of determining to increase the fluctuation evaluation value, the maximum change rate is subtracted from the preset change rate to obtain a first difference percentage, and the change range is subtracted from the preset range to obtain a second difference percentage,

[0041] Determining to increase the fluctuation evaluation value by a first adjustment coefficient based on a comparison result that the first difference percentage is greater than the second difference;

[0042] Based on the comparison result that the first difference percentage is less than or equal to the second difference percentage, it is determined to increase the fluctuation evaluation value by a second adjustment coefficient.

[0043] Further, under the condition of determining to reduce the fluctuation evaluation value, the preset change rate is subtracted from the maximum change rate to obtain a third difference percentage, and the preset range is subtracted from the change range to obtain a fourth difference percentage,

[0044] Determining to reduce the fluctuation evaluation value by a third adjustment coefficient based on a comparison result that the third difference percentage is greater than the fourth difference percentage;

[0045] Based on the comparison result that the third difference percentage is less than or equal to the fourth difference percentage, it is determined to reduce the fluctuation evaluation value by a fourth adjustment coefficient.

[0046] Compared with the prior art, the beneficial effect of the present invention lies in that the present invention constructs a spatial model through the image information of the diode, fits the spatial model and the standard model with different reference points, and determines whether the spatial shape of the diode is deformed according to the overall fitting degree. The deformation may cause the electrical connection in the package to be unstable or fail, affecting the electrical performance of the diode, causing cracks, delamination and other defects in the package, reducing the reliability and service life of the product, and also causing assembly difficulty and increasing the defective rate of the product; firstly, the qualification of the diode packaging in terms of spatial shape is determined, and then the qualification of the pin is determined according to the linear overlap of the pin. If the pin is bent, the contact reliability of the pin, the transmission quality of the diode, and the mechanical strength of the diode will be reduced. If the packaging is qualified, the path of the diode is determined by a multimeter, and if the path is qualified, further performance determination is performed, thereby improving the performance detection efficiency of the diode.

[0047] Furthermore, the present invention utilizes modeling to compare spatial forms, fits corresponding positions as reference points, and selects the maximum degree of fit to make a qualified judgment, thereby avoiding the contingency of inaccurate results caused by comparison with a single reference point, increasing the reliability of the comparison results, and performing subsequent tests under the condition of high accuracy of the comparison results, thereby improving the accuracy of subsequent performance tests and further improving the performance test efficiency of the diode.

[0048] Furthermore, the present invention calculates the offset variance through the offset distance to determine the linear coincidence, and then determines the eligibility of the pin according to the linear coincidence. The offset variance is an important indicator to measure the degree of discreteness of data distribution. In the evaluation of the pin straightness, the degree of pin bending or deformation can be quantified by calculating the offset variance between the actual position of the pin and the ideal straight position. By recording the offset variance data of each pin, a quality traceability system can be established. When it is found that the pin straightness is unqualified, it can be quickly traced back to the problem link in the production process, and corresponding measures can be taken to improve it, thereby further improving the performance detection efficiency of the diode.

[0049] Furthermore, after the diode is packaged qualifiedly, the present invention obtains the minimum dynamic resistance of the diode, and performs performance grading on the diode based on the minimum dynamic resistance. The smaller the minimum dynamic resistance value, the better the performance of the diode. The corresponding detection power supply is matched to the diode according to the grading result, and the temperature of the diode is monitored in real time during the detection process. The qualification of the grading result is determined based on the maximum temperature change rate and the change range. The smaller the maximum temperature change rate and the smallest change range, the better the performance of the diode. If the maximum change rate and the change range are too large, it means that the preliminary performance grading result of the diode is too high, and the fluctuation evaluation value needs to be lowered for re-determination. If the maximum change rate and the change range are too small, it means that the preliminary performance grading result of the diode is too low, and the fluctuation evaluation value needs to be increased for re-determination to correct the performance grading of the diode, thereby further improving the performance detection efficiency of the diode. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 This is a flow chart of a method for detecting automotive-grade diodes according to an embodiment of the present invention;

[0051] Figure 2 A flow chart for determining the eligibility of a diode's spatial morphology for an embodiment of the present invention;

[0052] Figure 3 A flow chart for determining whether a diode package is qualified according to an embodiment of the present invention;

[0053] Figure 4 The present invention is a flowchart of determining whether to adjust the fluctuation evaluation value according to an embodiment of the present invention. DETAILED DESCRIPTION

[0054] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments; it should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0055] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0056] It should be noted that, in the description of the present invention, terms such as "up", "down", "left", "right", "inside" and "outside" indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings. This is merely for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present invention.

[0057] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0058] See also Figure 1-Figure 4 As shown, Figure 1 This is a flow chart of a method for detecting automotive-grade diodes according to an embodiment of the present invention; Figure 2 A flow chart for determining the eligibility of a diode's spatial morphology for an embodiment of the present invention; Figure 3 A flow chart for determining whether a diode package is qualified according to an embodiment of the present invention; Figure 4 The present invention is a flowchart of determining whether to adjust the fluctuation evaluation value according to an embodiment of the present invention.

[0059] An embodiment of the present invention provides a method for detecting an automotive-grade diode, including:

[0060] Step S1, obtaining image information of several views of a diode, constructing a spatial model of the diode based on the image information, determining the eligibility of the spatial form of the diode package based on the overall fit between the spatial model and the standard model, and determining the eligibility of the diode package based on the linear coincidence of the pins of the spatial model, wherein the standard model is a spatial model of a diode that fully meets the design requirements, and wherein the several views are six views of the diode;

[0061] Step S2, using a multimeter to perform a preliminary test on the qualified packaged diode to determine whether the path of the qualified packaged diode is qualified;

[0062] Step S3, obtaining a volt-ampere characteristic curve of the diode under the condition that the path is qualified, and determining the minimum dynamic resistance of the diode based on the volt-ampere characteristic curve to preliminarily classify the performance of the diode;

[0063] Step S4, matching the fluctuation evaluation value of the detection voltage based on the preliminary classification result to provide the diode with a detection voltage corresponding to the fluctuation evaluation value, monitoring the temperature of the diode in real time during the detection process to establish a temperature fluctuation curve, and determining the maximum change rate and change range of the temperature based on the temperature fluctuation curve;

[0064] Step S5, determining whether to adjust the fluctuation evaluation value based on the maximum change rate and the change range to determine the performance grade of the diode.

[0065] Specifically, several image information of each view of the diode is collected at a position parallel to each view to ensure accurate acquisition of the spatial shape and size of the diode for precise modeling. The relationship between the view and the image information is one-to-one. It can be understood that in the prior art, the construction of a spatial model based on image information can use, for example, AutoCAD, without specific limitation.

[0066] Specifically, the process of determining the overall fit between the spatial model and the standard model based on the image information includes:

[0067] After preprocessing the image information of any view, feature extraction is performed, and the extracted features are input into a three-dimensional modeling software to construct a spatial model of the diode;

[0068] Performing fitting using the positions corresponding to the spatial model and the standard model as reference points to determine the degrees of fit;

[0069] The maximum value among the above-mentioned fitting degrees is determined as the overall fitting degree, and the fitting base point corresponding to the overall fitting degree is determined.

[0070] Specifically, the preprocessing of image information includes but is not limited to denoising and grayscale processing, which are not specifically limited, and the features include but are not limited to size features, shape features, pin spacing, texture features and color features, which are not specifically limited.

[0071] Specifically, there are many methods for fitting the spatial model with the standard model. For example, the reference points can be overlapped to determine the non-overlapping spatial volume, and the percentage obtained by comparing it with the spatial volume of the standard model is the degree of fit.

[0072] Specifically, the process of determining the eligibility of the spatial form based on the overall fit includes:

[0073] comparing the overall fitness with a preset fitness;

[0074] Determining that the spatial form is qualified based on a comparison result that the overall fit is greater than or equal to the preset fit;

[0075] The spatial form is determined to be unqualified based on the comparison result that the overall fit is less than the preset fit.

[0076] Specifically, the preset fitness value range is set to [90%, 99%], and 95% is preferred in the embodiment of the present invention.

[0077] Specifically, the process of determining the linear coincidence of the pins based on the qualified spatial form includes:

[0078] Overlapping the pins in the space model with the pins in the standard model based on the fitting base point;

[0079] determining a number of offset distances of the non-coincident positions to calculate the offset variance;

[0080] The offset variance is determined as the straight line coincidence.

[0081] It can be understood that the smaller the offset variance is, the straighter the pin is, and the smaller the straight line coincidence is, the more standard the pin package is.

[0082] Specifically, the offset distance is the distance between the standard model and the space model at the non-overlapping position, and the larger the distance, the larger the offset.

[0083] Specifically, the process of determining whether the diode package is qualified based on the straight line coincidence includes:

[0084] Comparing the straight line coincidence with a preset coincidence;

[0085] Determining that the diode package is qualified based on the comparison result that the straight line overlap is less than or equal to the preset overlap;

[0086] The diode package is determined to be unqualified based on the comparison result that the straight line overlap is greater than the preset overlap.

[0087] Specifically, the preset overlap value range is set to [0.1, 0.4], and 0.2 is preferred in the embodiment of the present invention.

[0088] Specifically, under the condition that the diode packaging is qualified, the diode with qualified path is determined by using a multimeter to determine the minimum dynamic resistance of the diode, and the process of preliminarily grading the performance of the diode based on the minimum dynamic resistance includes:

[0089] Comparing the minimum dynamic resistance with the first preset resistance and the second preset resistance respectively;

[0090] Determining that the performance of the diode is first-level performance based on a comparison result that the minimum dynamic resistance is less than or equal to the first preset resistance;

[0091] Determining that the performance of the diode is a secondary performance based on a comparison result that the minimum dynamic resistance is greater than the first preset resistance and less than or equal to the second preset resistance;

[0092] The performance of the diode is determined to be a third-level performance based on the comparison result that the minimum dynamic resistance is greater than the second preset resistance.

[0093] Specifically, the method of using a multimeter to determine the path of a diode is:

[0094] Set the multimeter to the diode-transistor test function and select the appropriate range;

[0095] Measure the forward resistance value: connect the red test pen to the anode (positive pole) of the diode under test, and the black test pen to the cathode (negative pole), and read the forward resistance value displayed by the multimeter. If the displayed value is infinite or close to infinite, it means that the diode may have problems such as open circuit or poor contact; if the displayed value is too low or close to zero, it means that the diode may have breakdown.

[0096] Measure the reverse resistance value: connect the red test pen to the cathode (negative pole) of the diode under test, and the black test pen to the anode (positive pole), and read the reverse resistance value displayed on the multimeter. The reverse resistance value should usually be much larger than the forward resistance value. If the reverse resistance value is too small, it means that the diode may have problems such as reverse leakage.

[0097] Specifically, the method for determining the minimum dynamic resistance is:

[0098] Use a transistor characteristic plotter to obtain the diode's volt-ampere characteristic curve;

[0099] Calculating the slopes of the volt-ampere characteristic curve and determining the maximum slope value;

[0100] The inverse of the maximum slope value is determined as the minimum dynamic resistance.

[0101] Specifically, the value range of the first preset resistance is set to [2Ω, 12Ω], and 5Ω is preferred in the embodiment of the present invention; the value range of the second preset resistance is set to [13Ω, 25Ω], and 16Ω is preferred in the embodiment of the present invention.

[0102] Specifically, the process of determining the maximum rate of change and range of temperature based on the performance grading results of the diode includes:

[0103] Matching a corresponding fluctuation evaluation value for the diode based on the performance grading result, and providing a corresponding detection voltage for the diode based on the fluctuation evaluation value for performance detection;

[0104] The temperature of the diode is monitored in real time to establish a temperature fluctuation curve, and the maximum temperature, the minimum temperature and the maximum change rate are determined based on the temperature fluctuation curve, and the difference between the maximum temperature and the minimum temperature is determined as the change range.

[0105] Specifically, the voltage fluctuation evaluation value is determined by the voltage fluctuation frequency and fluctuation amplitude. The calculation formula of the fluctuation evaluation value is as follows:

[0106]

[0107] Among them, α represents the weight coefficient of the voltage fluctuation frequency, and α is set to 0.5. i represents the i-th fluctuation cycle, Ti represents the duration of the i-th fluctuation cycle, T0 represents the standard duration of a fluctuation cycle, β represents the weight coefficient of the voltage fluctuation amplitude, and β is set to 0.5. Li represents the voltage peak value of the i-th fluctuation cycle, and L0 represents the standard peak value of a fluctuation cycle.

[0108] It can be understood that the larger the P, the worse the regularity of voltage fluctuation.

[0109] Specifically, in the embodiment of the present invention, based on the initial performance grading results, for a diode with first-level performance, a detection voltage with a matching fluctuation evaluation value of 9 is used; for a diode with second-level performance, a detection voltage with a matching fluctuation evaluation value of 7 is used; and for a diode with third-level performance, a detection voltage with a matching fluctuation evaluation value of 5 is used.

[0110] Specifically, in the embodiment of the present invention, the range of the fluctuation evaluation value is [4, 6] for detecting the third-level performance, the range of the fluctuation evaluation value is (6, 9) for detecting the second-level performance, and the range of the fluctuation evaluation value is [9, 10) for detecting the first-level performance.

[0111] Specifically, the process of determining whether to adjust the fluctuation evaluation value based on the maximum change rate and the change range includes:

[0112] Comparing the maximum change rate with a preset change rate, and comparing the change range with a preset range;

[0113] Determining to increase the fluctuation evaluation value based on a comparison result that the maximum change rate is greater than the preset change rate and the change range is greater than the preset range;

[0114] The fluctuation evaluation value is reduced based on a comparison result that the maximum change rate is smaller than the preset change rate and the change range is smaller than the preset range.

[0115] Specifically, for situations other than the above two situations, no adjustment will be made to the fluctuation evaluation value.

[0116] Specifically, the value range of the preset change rate is set to [0.5, 3], and 0.8 is preferred in the embodiment of the present invention; the value range of the preset range is set to [10°C, 40°C], and 15°C is preferred in the embodiment of the present invention.

[0117] Specifically, the smaller the maximum change rate, the smaller the temperature change rate, and the smaller the change range, the smaller the temperature fluctuation amplitude, which means the better the performance of the diode.

[0118] Specifically, for the condition of increasing the fluctuation evaluation value, the maximum change rate is subtracted from the preset change rate to obtain a first difference percentage, and the change range is subtracted from the preset range to obtain a second difference percentage.

[0119] Determining to increase the fluctuation evaluation value by a first adjustment coefficient based on a comparison result that the first difference percentage is greater than the second difference percentage;

[0120] Based on the comparison result that the first difference percentage is less than or equal to the second difference percentage, it is determined to increase the fluctuation evaluation value by a second adjustment coefficient.

[0121] Specifically, the value range of the first adjustment coefficient is set to [1.1, 1.3], and 1.2 is preferably selected in the embodiment of the present invention; the value range of the second adjustment coefficient is set to [1.4, 1.7], and 1.5 is preferably selected in the embodiment of the present invention.

[0122] Specifically, for the condition of reducing the fluctuation evaluation value, the preset change rate is subtracted from the maximum change rate to obtain a third difference percentage, and the preset range is subtracted from the change range to obtain a fourth difference percentage.

[0123] Determining to reduce the fluctuation evaluation value by a third adjustment coefficient based on a comparison result that the third difference percentage is greater than the fourth difference percentage;

[0124] Based on the comparison result that the third difference percentage is less than or equal to the fourth difference percentage, it is determined to reduce the fluctuation evaluation value by a fourth adjustment coefficient.

[0125] Specifically, the value range of the third adjustment coefficient is set to [0.85, 0.92], and 0.9 is preferably used in the embodiment of the present invention; the value range of the second adjustment coefficient is set to [0.7, 0.84], and 0.75 is preferably used in the embodiment of the present invention.

[0126] Specifically, when faced with complex voltages, the temperature variation range has a greater impact on the performance of the diode.

[0127] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A method for detecting automotive-grade diodes, characterized in that: include: Acquire multiple image information of multiple views of the diode, construct a spatial model of the diode based on the image information, determine the eligibility of the spatial form of the diode package based on the overall fit between the spatial model and the standard model, and determine the eligibility of the diode package based on the linear coincidence of the pins of the spatial model, wherein the standard model is a spatial model of the diode that fully meets the design requirements, and wherein the multiple views are six views of the diode; Use a multimeter to conduct a preliminary test on the qualified packaged diode to determine whether the path of the qualified packaged diode is qualified; Acquiring a volt-ampere characteristic curve of a diode under a qualified path condition, and determining a minimum dynamic resistance of the diode based on the volt-ampere characteristic curve to preliminarily grade the performance of the diode; Matching the fluctuation evaluation value of the detection voltage based on the preliminary classification result to provide the diode with a detection voltage corresponding to the fluctuation evaluation value, monitoring the temperature of the diode in real time during the detection process to establish a temperature fluctuation curve, and determining the maximum change rate and change range of the temperature based on the temperature fluctuation curve; determining whether to adjust the fluctuation evaluation value to determine a performance grade of a diode based on the maximum change rate and the change range; Under the condition that the diode packaging is qualified, a multimeter is used to determine the diode with qualified path to determine the minimum dynamic resistance of the diode. The process of preliminarily grading the performance of the diode based on the minimum dynamic resistance includes: Comparing the minimum dynamic resistance with the first preset resistance and the second preset resistance respectively; Determining that the performance of the diode is first-level performance based on a comparison result that the minimum dynamic resistance is less than or equal to the first preset resistance; Determining that the performance of the diode is a secondary performance based on a comparison result that the minimum dynamic resistance is greater than the first preset resistance and less than or equal to the second preset resistance; Determining that the performance of the diode is level 3 performance based on a comparison result that the minimum dynamic resistance is greater than the second preset resistance; The process of determining the maximum rate and range of temperature change based on the diode performance grading results includes: Matching a corresponding fluctuation evaluation value for the diode based on the performance grading result, and providing a corresponding detection voltage for the diode based on the fluctuation evaluation value for performance detection; Monitor the temperature of the diode in real time to establish a temperature fluctuation curve, determine the maximum temperature, the minimum temperature and the maximum change rate based on the temperature fluctuation curve, and determine the difference between the maximum temperature and the minimum temperature as the variation range; The process of determining whether to adjust the fluctuation evaluation value based on the maximum change rate and the change range includes: Comparing the maximum change rate with a preset change rate, and comparing the change range with a preset range; Determining to increase the fluctuation evaluation value based on a comparison result that the maximum change rate is greater than the preset change rate and the change range is greater than the preset range; The fluctuation evaluation value is reduced based on a comparison result that the maximum change rate is smaller than the preset change rate and the change range is smaller than the preset range.

2. The automotive-grade diode detection method according to claim 1, characterized in that: The process of determining the overall fit between the spatial model and the standard model based on the image information includes: After preprocessing the image information of any view, feature extraction is performed, and the extracted features are input into a three-dimensional modeling software to construct a spatial model of the diode; Performing fitting using the positions corresponding to the spatial model and the standard model as reference points to determine the degrees of fit; The maximum value among the above-mentioned fitting degrees is determined as the overall fitting degree, and the fitting base point corresponding to the overall fitting degree is determined.

3. The automotive-grade diode detection method according to claim 2, characterized in that: The process of determining the eligibility of the spatial form based on the overall fit includes: comparing the overall fitness with a preset fitness; The spatial form is determined to be qualified based on the comparison result that the overall fit is greater than or equal to the preset fit.

4. The automotive-grade diode detection method according to claim 3 is characterized in that: The process of determining the linear coincidence of the pins based on the qualified spatial form includes: Overlapping the pins in the space model with the pins in the standard model based on the fitting base point; determining a number of offset distances of the non-coincident positions to calculate the offset variance; The offset variance is determined as the straight line coincidence.

5. The automotive-grade diode detection method according to claim 4, characterized in that: The process of determining whether the diode package is qualified based on the linear coincidence degree includes: Comparing the straight line coincidence with a preset coincidence; The diode package is determined to be qualified based on the comparison result that the straight line overlap is less than or equal to the preset overlap.

6. The automotive-grade diode detection method according to claim 5, characterized in that: Under the condition of determining to increase the fluctuation evaluation value, the maximum change rate is subtracted from the preset change rate to obtain a first difference percentage, and the change range is subtracted from the preset range to obtain a second difference percentage, Determining to increase the fluctuation evaluation value by a first adjustment coefficient based on a comparison result that the first difference percentage is greater than the second difference; Based on the comparison result that the first difference percentage is less than or equal to the second difference percentage, it is determined to increase the fluctuation evaluation value by a second adjustment coefficient.

7. The automotive-grade diode detection method according to claim 6, characterized in that: Under the condition of determining to reduce the fluctuation evaluation value, the preset change rate is subtracted from the maximum change rate to obtain a third difference percentage, and the preset range is subtracted from the change range to obtain a fourth difference percentage, Determining to reduce the fluctuation evaluation value by a third adjustment coefficient based on a comparison result that the third difference percentage is greater than the fourth difference percentage; Based on the comparison result that the third difference percentage is less than or equal to the fourth difference percentage, it is determined to reduce the fluctuation evaluation value by a fourth adjustment coefficient.

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