Method for detecting electrostatic tolerance of smart card
By performing electrostatic simulation and peeling off the substrate layer before the smart card semi-finished product is pressed, and combining human body and machine discharge modes for multiple simulations, the problem of inaccurate electrostatic tolerance detection of smart cards in the prior art has been solved, and more accurate chip detection has been achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- BEIJING CEC HUADA ELECTRONIC DESIGN CO LTD
- Filing Date
- 2026-02-28
- Publication Date
- 2026-05-08
AI Technical Summary
In existing technologies, it is difficult to accurately obtain the detection parameters of the chip encased in the substrate when testing the electrostatic withstand capability of smart cards, resulting in inaccurate detection results.
Electrostatic simulation was performed before the smart card semi-finished product was pressed. After the substrate layer was peeled off, performance testing was carried out. Multiple electrostatic simulations were performed in combination with human body and machine discharge modes, focusing on the performance testing of the chip.
This improves the accuracy of electrostatic discharge (ESD) tolerance testing, enabling more accurate acquisition of chip testing parameters that reflect their true ESD tolerance.
Smart Images
Figure CN121995146A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of smart card performance testing technology, and in particular to a method for testing the electrostatic withstand capability of a smart card. Background Technology
[0002] In smart cards, the chip is the core functional unit. During the smart card manufacturing process, the chip faces the threat of electrostatic discharge (ESD) during the lamination process. Related technologies typically perform ESD tests on the finished laminated product, making it difficult to obtain accurate testing parameters for the chip encapsulated within the substrate, resulting in inaccurate ESD test results. Summary of the Invention
[0003] This application provides a method for detecting the electrostatic discharge (ESD) tolerance of a smart card, which can improve the accuracy of ESD tolerance detection results.
[0004] This application provides a method for testing the electrostatic discharge (ESD) tolerance of smart cards, comprising: acquiring multiple smart card semi-finished products of a batch of smart cards to be tested, wherein each smart card semi-finished product includes a chip, a first substrate layer, a second substrate layer, and a third substrate layer, wherein the chip is integrated on the first substrate layer, and the second and third substrate layers are located on two opposite surfaces of the first substrate layer and are not laminated; performing an ESD simulation of a lamination scenario on each smart card semi-finished product by discharging it; peeling off the second and third substrate layers of the smart card semi-finished product after the ESD simulation; performing performance testing on each of the peeled smart card semi-finished products to obtain performance test data; and determining the ESD tolerance test result of the batch of smart cards to be tested based on the performance test data.
[0005] According to some of the foregoing embodiments of this application, the step of performing electrostatic simulation of a lamination scenario on each smart card semi-finished product by discharging the smart card semi-finished product includes: discharging the smart card semi-finished product in human body discharge mode to perform electrostatic simulation of overlapping friction in a lamination scenario; and discharging the smart card semi-finished product in machine discharge mode to perform electrostatic simulation of pressurized contact in a lamination scenario.
[0006] According to some of the foregoing embodiments of this application, the step of performing electrostatic simulation of a lamination scenario for each smart card semi-finished product by discharging the smart card semi-finished product includes: sequentially numbering the multiple smart card semi-finished products; and performing electrostatic simulation of a lamination scenario for each smart card semi-finished product by discharging the smart card semi-finished product, wherein the discharge voltage conditions matched to smart card semi-finished products with different numbers are different.
[0007] According to some of the foregoing embodiments of this application, the electrostatic simulation of the lamination scenario by discharging each of the smart card semi-finished products includes: sequentially discharging each of the smart card semi-finished products in ascending order of their numbers using a human body discharge mode and a machine discharge mode. The discharge voltage in the human body discharge mode corresponding to the smart card semi-finished product with the first number is 2000V, and the discharge voltage in the machine discharge mode corresponding to the smart card semi-finished product with the first number is 1000V. For each subsequent smart card semi-finished product, the discharge voltage in the human body discharge mode is increased by at least one voltage level compared to the previous smart card semi-finished product, and / or the discharge voltage in the machine discharge mode is increased by at least one voltage level. Each voltage level in the human body discharge mode is 500V, and each voltage level in the machine discharge mode is 1000V.
[0008] According to some of the foregoing embodiments of this application, the discharge in human body discharge mode includes: discharging the area where the chip of the smart card semi-finished product is located three times in human body discharge mode.
[0009] According to some of the foregoing embodiments of this application, the machine discharge mode discharge includes: discharging each pin solder joint of the chip of the smart card semi-finished product once in sequence in machine discharge mode, wherein the discharge interval is 10s.
[0010] According to some of the foregoing embodiments of this application, the step of performing performance testing on each of the smart card semi-finished products after stripping to obtain performance test data includes: performing a first electrical performance test on the smart card semi-finished product; if the first electrical performance test is not passed, the performance test ends; performing a physical structure test on the smart card semi-finished product that passes the first electrical performance test; if the physical structure test is not passed, the performance test ends; performing a second electrical performance test on the smart card semi-finished product that passes the physical structure test after a preset number of temperature change cycles; if the second electrical performance test is not passed, the performance test ends; and determining the smart card semi-finished product that passes the first electrical performance test, the physical structure test, and the second electrical performance test as having passed the performance test.
[0011] According to some of the foregoing embodiments of this application, the first electrical performance test of the smart card semi-finished product includes: detecting the values of multiple electrical parameters of the smart card semi-finished product to obtain first detection information. The multiple electrical parameters include resonant frequency, quality factor, pin on-resistance, semiconductor device threshold voltage, semiconductor device leakage current, and the IV curve of pulse current and clamping voltage. If any electrical parameter in the first detection information deviates by more than 10% from the electrical parameter in the initial detection information, the smart card semi-finished product is determined to have failed the first electrical performance test; otherwise, the smart card semi-finished product is determined to have passed the first electrical performance test. The initial detection information includes the values of the multiple electrical parameters of the smart card semi-finished product before it is discharged. The physical structure test of the smart card semi-finished product that has passed the first electrical performance test includes: using a display... The micro-imaging system detects whether there are appearance defects in the area where the chip of the smart card semi-finished product is located. If appearance defects are found, the smart card semi-finished product is determined to have failed the physical structure test; otherwise, the smart card semi-finished product is determined to have passed the physical structure test. After performing a preset number of temperature change cycles on the smart card semi-finished product that has passed the physical structure test, a second electrical performance test is performed, including: after performing a preset number of temperature change cycles on the smart card semi-finished product that has passed the physical structure test, detecting the values of the multiple electrical parameters of the smart card semi-finished product to obtain second detection information. If any electrical parameter in the second detection information has an offset of more than 10% relative to the electrical parameter in the initial detection information, the smart card semi-finished product is determined to have failed the second electrical performance test; otherwise, the smart card semi-finished product is determined to have passed the second electrical performance test.
[0012] According to some of the foregoing embodiments of this application, determining the electrostatic discharge tolerance test results of the smart card batch to be tested based on the performance test data includes: identifying the smart card semi-finished product that has passed the performance test as an evaluation sample; determining the grade of the evaluation sample based on the discharge voltage that each evaluation sample has undergone discharge; and determining the electrostatic discharge tolerance test results of the smart card batch to be tested based on the grades of all the evaluation samples.
[0013] According to some of the foregoing embodiments of this application, determining the level of the evaluation sample based on the discharge voltage of each evaluation sample that has been discharged includes: if the discharge voltage of the evaluation sample under human body discharge mode is less than 10kV, and / or the discharge voltage of the evaluation sample under machine discharge mode is less than 4kV, then the evaluation sample is determined to be a Level 3 evaluation sample; if the discharge voltage of the evaluation sample under human body discharge mode is 10kV to 15kV and the discharge voltage under machine discharge mode is greater than or equal to 4kV, or if the discharge voltage of the evaluation sample under human body discharge mode is greater than or equal to 10kV and the discharge voltage under machine discharge mode is 4kV to 8kV, then the evaluation sample is determined to be a Level 2 evaluation sample; if the discharge voltage of the evaluation sample under human body discharge mode is less than or equal to 15kV and the discharge voltage under machine discharge mode is less than or equal to 8kV, then the evaluation sample is determined to be a Level 1 evaluation sample.
[0014] According to some of the foregoing embodiments of this application, determining the electrostatic discharge (ESD) tolerance test result of the smart card batch to be tested based on the grades of all the evaluation samples includes: if there are no secondary evaluation samples and no primary evaluation samples among all the evaluation samples, then the ESD tolerance test result of the smart card batch to be tested is determined to be unqualified; if there are secondary evaluation samples among all the evaluation samples, then the ESD tolerance test result of the smart card batch to be tested is determined to be qualified; if there are primary evaluation samples among all the evaluation samples, then the ESD tolerance test result of the smart card batch to be tested is determined to be qualified and excellent.
[0015] According to the electrostatic discharge (ESD) tolerance testing method for smart cards in this application, multiple semi-finished smart card products of a batch of smart cards to be tested are obtained. Each semi-finished smart card product includes a chip, a first substrate layer, a second substrate layer, and a third substrate layer. The chip is integrated into the first substrate layer, and the second and third substrate layers are located on opposite surfaces of the first substrate layer and are not laminated. By discharging the semi-finished smart card products, an ESD simulation of a lamination scenario is performed on each semi-finished smart card product. The second and third substrate layers of the semi-finished smart card products after the ESD simulation are completed are then peeled off. Performance testing is performed on each semi-finished smart card product after peeling to obtain performance test data. Based on the performance test data, the ESD tolerance test result of the batch of smart cards to be tested is determined. In the above scheme, the ESD simulation of a lamination scenario is performed on the semi-finished smart card products, and the second and third substrate layers are peeled off, exposing the chip. Subsequent performance testing focuses more on the chip, replacing the performance testing of the chip through the substrate layer in related technologies. This allows for more accurate chip testing parameters and more accurate ESD tolerance test results. Attached Figure Description
[0016] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.
[0017] Figure 1 This is a flowchart illustrating one embodiment of the electrostatic tolerance testing method for smart cards according to this application; Figure 2 This is a schematic diagram of the layer structure of a smart card semi-finished product in one embodiment of the electrostatic withstand capability testing method for smart cards according to this application; Figure 3 This is a top view of a smart card semi-finished product with the second and third substrate layers hidden, according to one embodiment of the electrostatic withstand capability testing method for smart cards in this application. Figure 4 This is a schematic diagram of a scenario where discharge is applied to a smart card semi-finished product according to one embodiment of the electrostatic withstand capability detection method for smart cards in this application. Figure 5 This is a schematic diagram of the process for performing performance testing on each smart card semi-finished product after stripping, according to one embodiment of the electrostatic withstand capability testing method for smart cards in this application. Detailed Implementation
[0018] The technical solutions in the embodiments (or "implementations") of this application will be clearly and completely described herein with reference to the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.
[0019] If the embodiments of this application contain terms relating to directional indications or positional relationships (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationships and movement of the components in a specific posture (as shown in the attached figures); if the specific posture changes, the directional indications or positional relationships will also change accordingly. Furthermore, the terms "first" and "second" used in the embodiments of this application are only for descriptive convenience and should not be construed as indicating or implying relative importance.
[0020] This application provides a method for detecting the electrostatic tolerance of a smart card. Figure 1 This is a schematic flowchart of one embodiment of the electrostatic discharge (ESD) tolerance testing method for a smart card according to this application. The ESD tolerance testing method for a smart card includes steps S110 to S150.
[0021] In step S110, multiple smart card semi-finished products of the batch of smart cards to be tested are obtained. Figure 2This is a schematic diagram of the layer structure of a smart card semi-finished product in one embodiment of the electrostatic withstand capability testing method for smart cards according to this application. Figure 3 This is a top view of a smart card semi-finished product with the second and third substrate layers hidden, according to one embodiment of the electrostatic discharge tolerance testing method for smart cards of this application. The smart card semi-finished product includes a chip 110, a first substrate layer 121, a second substrate layer 122, and a third substrate layer 123. The chip 110 is integrated into the first substrate layer 121. The second substrate layer 122 and the third substrate layer 123 are located on two opposite surfaces of the first substrate layer 121 and are not pressed together. The first substrate layer 121, the second substrate layer 122, and the third substrate layer 123 are insulating material layers, such as polyvinyl chloride (PVC) layers.
[0022] In some embodiments, the smart card semi-finished product further includes an RF coil 130, which is integrated into the first substrate layer 121. The RF coil 130 is electrically connected to the chip 110.
[0023] In some embodiments, after obtaining multiple smart card semi-finished products of the batch of smart cards to be tested, the following steps may be included: preprocessing each smart card semi-finished product.
[0024] Specifically, the pretreatment of each smart card semi-finished product may include: cutting the smart card semi-finished product to a specific size; and storing the smart card semi-finished product in a constant temperature and humidity chamber for a first preset time, wherein the temperature in the constant temperature and humidity chamber is 23±2℃ and the relative humidity is 30% to 40%. This environment simulates a high-static-risk production environment. In one example, the smart card semi-finished product is cut to a specific size of 100mm × 54mm. In another example, the smart card semi-finished product is stored in the constant temperature and humidity chamber for 48 hours. After completing the pretreatment of each smart card semi-finished product, subsequent steps are performed after a second preset time. For example, after completing the pretreatment of each smart card semi-finished product, subsequent steps are performed after a 1-hour wait to maintain charge stability.
[0025] In step S120, electrostatic simulation of the lamination scenario is performed on each smart card semi-finished product by discharging a discharge to it.
[0026] Figure 4This is a schematic diagram of a scenario structure for discharging a semi-finished smart card according to one embodiment of the electrostatic discharge tolerance testing method for smart cards of this application. In this embodiment, the discharge to the semi-finished smart card is performed using an electrostatic gun assembly. When discharging the semi-finished smart card to simulate electrostatic discharge in a lamination scenario, the semi-finished smart card 100 is placed on an operating platform 210. In this embodiment, an insulating pad 220 is provided on the operating platform 210, and the semi-finished smart card 100 is placed on the insulating pad 220. The electrostatic gun assembly includes an electrostatic gun 231 and an electrostatic generator 232. The electrostatic gun 231 is electrically connected to the electrostatic generator 232, which can generate simulated electrostatic discharge. In this embodiment, the electrostatic gun assembly has a Human-Body Model (HBM) and a Machine Model (MM) discharge mode. The discharge voltage adjustment range is 0 to 30 kV, and the discharge time is 1 μs to 100 μs.
[0027] In some embodiments, step S120, which involves discharging a discharge source into a smart card semi-finished product to simulate electrostatic discharge in a lamination scenario for each smart card semi-finished product, includes: discharging a discharge source into the smart card semi-finished product in a human body discharge mode to simulate electrostatic discharge of overlapping friction in a lamination scenario for the smart card semi-finished product; and discharging a discharge source into the smart card semi-finished product in a machine discharge mode to simulate electrostatic discharge of pressurized contact in a lamination scenario for the smart card semi-finished product.
[0028] In traditional technical solutions, discharge simulation is a single-point discharge at a fixed potential, failing to distinguish between different scenarios of overlapping friction and pressurized contact in lamination, resulting in low matching with the actual loss scenarios of smart cards. In the embodiments of this application, discharge is applied to the smart card semi-finished product in human body discharge mode to simulate electrostatic discharge of overlapping friction in lamination scenarios, and discharge is applied to the smart card semi-finished product in machine discharge mode to simulate electrostatic discharge of pressurized contact in lamination scenarios. Combining multiple discharge modes for electrostatic simulation makes it closer to the actual loss scenarios of smart cards.
[0029] In some embodiments, step S120, which simulates the electrostatic discharge scenario for each smart card semi-finished product by discharging the smart card semi-finished product, includes: sequentially numbering multiple smart card semi-finished products; and simulating the electrostatic discharge scenario for each smart card semi-finished product by discharging the smart card semi-finished product, wherein the discharge voltage conditions matched to smart card semi-finished products with different numbers are different.
[0030] Specifically, electrostatic simulation of a lamination scenario is performed on each smart card semi-finished product through discharge, including: discharging each smart card semi-finished product in ascending order of its number in human body discharge mode and machine discharge mode. The discharge voltage of the smart card semi-finished product with the first number is 2000V in human body discharge mode and 1000V in machine discharge mode. The discharge voltage of subsequent smart card semi-finished products is increased by at least one voltage level in human body discharge mode and / or at least one voltage level in machine discharge mode compared to the previous smart card semi-finished products. Each voltage level in human body discharge mode is 500V and each voltage level in machine discharge mode is 1000V.
[0031] In some embodiments, performing human body discharge mode includes: discharging the area where the chip 110 of the smart card semi-finished product is located three times in human body discharge mode.
[0032] In some embodiments, performing machine discharge mode discharge includes: discharging each pin solder joint of the chip 110 of the smart card semi-finished product once in sequence in machine discharge mode, wherein the discharge interval is 10s. Figure 3 In the diagram, discharge points P1 and P2 are the two pin solder joints of chip 110 in the smart card semi-finished product.
[0033] In step S130, the second substrate layer 122 and the third substrate layer 123 of the smart card semi-finished product after electrostatic simulation are peeled off.
[0034] In some embodiments, in the initial smart card semi-finished product, the second substrate layer 122 and the third substrate layer 123 are bonded to two opposite surfaces of the first substrate layer 121 but not pressed together. In step S130, the second substrate layer 122 and the third substrate layer 123 can be peeled off, leaving the first substrate layer 121 on which the chip 110 is integrated, at which point the chip 110 is exposed.
[0035] In step S140, performance testing is performed on each smart card semi-finished product that has been stripped to obtain performance test data.
[0036] Figure 5 This is a flowchart illustrating the performance testing of each smart card semi-finished product after stripping, according to one embodiment of the electrostatic withstand capability testing method for smart cards of this application. In some embodiments, step S140, which involves performing performance testing on each smart card semi-finished product after stripping to obtain performance test data, includes steps S141 to S144.
[0037] In step S141, the smart card semi-finished product undergoes a first electrical performance test. If the first electrical performance test fails, the performance test ends.
[0038] In step S142, the smart card semi-finished product that has passed the first electrical performance test is subjected to a physical structure test. If it fails the physical structure test, the performance test ends.
[0039] In step S143, after the smart card semi-finished product that has passed the physical structure test is subjected to a preset number of temperature change cycles, a second electrical performance test is performed. If the second electrical performance test is not passed, the performance test ends.
[0040] In step S144, the smart card semi-finished product that passes the first electrical performance test, the physical structure test, and the second electrical performance test is determined to have passed the performance test.
[0041] In some embodiments, the above-described first electrical performance test on the smart card semi-finished product includes: detecting the values of multiple electrical parameters of the smart card semi-finished product to obtain first detection information. The multiple electrical parameters include resonant frequency, quality factor (Q value), pin on-resistance, semiconductor device threshold voltage, semiconductor device leakage current, and the IV (current-voltage) curve of pulse current and clamping voltage. If any electrical parameter in the first detection information deviates by more than 10% from the electrical parameters in the initial detection information, the smart card semi-finished product is determined to have failed the first electrical performance test; otherwise, the smart card semi-finished product is determined to have passed the first electrical performance test. The initial detection information includes the values of multiple electrical parameters of the smart card semi-finished product before it undergoes discharge.
[0042] In some embodiments, the resonant frequency and quality factor of the smart card semi-finished product are detected using an impedance tester. In some embodiments, the on-resistance of the pins, the threshold voltage of the semiconductor device, and the leakage current of the semiconductor device are detected using a semiconductor parameter analyzer. In some embodiments, an IV curve of pulse current versus clamping voltage is plotted using a transmission line pulse (TLP) tester. In this embodiment, whether the offset of the IV curve in the first detection information relative to the IV curve in the initial detection information exceeds 10% can be determined by judging whether the offset of several preset feature points on the IV curve exceeds 10%. For example, on the IV curve, preset feature points are a first feature point with a voltage value of 0.7V, a second feature point with a voltage value of 1.4V, a third feature point with a voltage value of 2.5V, and a fourth feature point with a voltage value of 3.3V. By comparing the current values of the two IV curves at these feature points, if the current value deviation at at least one feature point exceeds 10%, it is determined that the deviation of the IV curve in the first detection information relative to the IV curve in the initial detection information exceeds 10%; otherwise, it is determined that the deviation of the IV curve in the first detection information relative to the IV curve in the initial detection information does not exceed 10%. By performing the first electrical performance test on the smart card semi-finished product, it is possible to assess whether there is any hidden damage.
[0043] In some embodiments, the above-mentioned physical structure test of the smart card semi-finished product that has passed the first electrical performance test includes: detecting whether there are appearance defects in the area where the chip 110 of the smart card semi-finished product is located by using a microscopic imaging system; if there are appearance defects, it is determined that the smart card semi-finished product has not passed the physical structure test; otherwise, it is determined that the smart card semi-finished product has passed the physical structure test.
[0044] In some embodiments, appearance defects include, for example, cracks in the chip 110 package, burn marks on the pin solder joints, and melting points in the protection diode area. Physical structural inspection of the smart card semi-finished product can assess whether it exhibits any visible damage.
[0045] In some embodiments, after subjecting the smart card semi-finished product that has passed the physical structure test to a preset number of temperature change cycles, performing a second electrical performance test includes: after subjecting the smart card semi-finished product that has passed the physical structure test to a preset number of temperature change cycles, detecting the values of multiple electrical parameters of the smart card semi-finished product to obtain second detection information. If any electrical parameter in the second detection information deviates by more than 10% from the electrical parameter in the initial detection information, the smart card semi-finished product is determined to have failed the second electrical performance test; otherwise, the smart card semi-finished product is determined to have passed the second electrical performance test.
[0046] In one example, a semi-finished smart card that has passed the physical structure test is subjected to 100 temperature change cycles, with each cycle changing the temperature from -40°C to 85°C. After performing a preset number of temperature change cycles on the semi-finished smart card that has passed the physical structure test, a second electrical performance test is conducted to assess the cumulative effect of its electrostatic damage.
[0047] In step S150, the electrostatic withstand capability test results of the batch of smart cards to be tested are determined based on the performance test data.
[0048] In some embodiments, step S150, which determines the electrostatic discharge tolerance test results of the batch of smart cards to be tested based on performance test data, includes: identifying the semi-finished smart cards that have passed the performance test as evaluation samples; determining the grade of the evaluation samples based on the discharge voltage that each evaluation sample has been discharged; and determining the electrostatic discharge tolerance test results of the batch of smart cards to be tested based on the grades of all evaluation samples.
[0049] In some embodiments, the level of an evaluation sample is determined based on the discharge voltage that each evaluation sample has received, including: if the discharge voltage of the evaluation sample under human body discharge mode is less than 10kV, and / or the discharge voltage of the evaluation sample under machine discharge mode is less than 4kV, then the evaluation sample is determined to be a Level 3 evaluation sample; if the discharge voltage of the evaluation sample under human body discharge mode is 10kV to 15kV and the discharge voltage under machine discharge mode is greater than or equal to 4kV, or if the discharge voltage of the evaluation sample under human body discharge mode is greater than or equal to 10kV and the discharge voltage under machine discharge mode is 4kV to 8kV, then the evaluation sample is determined to be a Level 2 evaluation sample; if the discharge voltage of the evaluation sample under human body discharge mode is less than or equal to 15kV and the discharge voltage under machine discharge mode is less than or equal to 8kV, then the evaluation sample is determined to be a Level 1 evaluation sample.
[0050] In some embodiments, determining the electrostatic discharge (ESD) tolerance test result of the smart card batch to be tested based on the grades of all tested samples includes: if there are no secondary test samples and no primary test samples among all tested samples, the ESD tolerance test result of the smart card batch to be tested is determined to be unqualified; if there are secondary test samples among all tested samples, the ESD tolerance test result of the smart card batch to be tested is determined to be qualified; if there are primary test samples among all tested samples, the ESD tolerance test result of the smart card batch to be tested is determined to be qualified and excellent.
[0051] In one example, if a Level 1 test sample is found to have a discharge voltage of 16kV under human body discharge mode and a discharge voltage of 9kV under machine discharge mode, then the electrostatic withstand capability test result of the batch of smart cards to be tested is determined to be qualified and excellent.
[0052] According to the electrostatic discharge (ESD) tolerance testing method for smart cards in this application embodiment, multiple smart card semi-finished products of a batch of smart cards to be tested are obtained. Each semi-finished product includes a chip 110, a first substrate layer 121, a second substrate layer 122, and a third substrate layer 123. The chip 110 is integrated into the first substrate layer 121, and the second and third substrate layers 122 and 123 are located on opposite surfaces of the first substrate layer 121 and are not laminated. An ESD simulation of a lamination scenario is performed on each semi-finished smart card by discharging it into the substrate. The second and third substrate layers 122 and 123 of the semi-finished smart card after the ESD simulation is completed are then peeled off. Performance testing is performed on each peeled semi-finished smart card to obtain performance test data. The ESD tolerance test result of the batch of smart cards to be tested is determined based on the performance test data. In the above solution, electrostatic simulation of the lamination scenario is performed on the smart card semi-finished product, and its second substrate layer 122 and third substrate layer 123 are peeled off to expose the chip 110. Subsequent performance testing can then focus more on the chip 110, replacing the performance testing of the chip 110 through the substrate layer in related technologies. This allows for obtaining more accurate test parameters of the chip 110, resulting in more accurate electrostatic tolerance test results.
[0053] According to the electrostatic tolerance testing method for smart cards in this application embodiment, discharge is applied to the smart card semi-finished product in human body discharge mode to simulate electrostatic friction of overlapping friction in a lamination scenario, and discharge is applied to the smart card semi-finished product in machine discharge mode to simulate electrostatic contact of pressurized contact in a lamination scenario. Combining multiple discharge modes for electrostatic simulation makes it closer to the actual loss scenario of smart cards.
[0054] It should be noted that the technical solutions or features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the accompanying drawings; all modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.
Claims
1. A method for detecting the electrostatic withstand capability of a smart card, characterized in that, include: Multiple smart card semi-finished products of a batch of smart cards to be tested are obtained. The smart card semi-finished products include a chip, a first substrate layer, a second substrate layer and a third substrate layer. The chip is integrated on the first substrate layer, and the second substrate layer and the third substrate layer are located on two opposite surfaces of the first substrate layer and are not pressed together. Electrostatic simulation of a lamination scenario is performed on each of the smart card semi-finished products by discharging a discharge into it. The second substrate layer and the third substrate layer of the smart card semi-finished product after electrostatic simulation are peeled off. Each of the smart card semi-finished products that has been stripped is subjected to performance testing to obtain performance test data; The electrostatic discharge tolerance test results of the batch of smart cards to be tested are determined based on the performance test data.
2. The electrostatic withstand capability testing method for smart cards according to claim 1, characterized in that, The step of simulating electrostatic discharge in the lamination scenario for each smart card semi-finished product includes: Discharge is applied to the smart card semi-finished product in human body discharge mode to simulate electrostatic friction of lamination in the smart card semi-finished product. Discharge is applied to the smart card semi-finished product in machine discharge mode to simulate electrostatic contact under pressure in a lamination scenario.
3. The electrostatic withstand capability testing method for smart cards according to claim 1, characterized in that, The step of simulating electrostatic discharge in the lamination scenario for each smart card semi-finished product includes: Number the multiple smart card semi-finished products sequentially; Electrostatic simulation of a lamination scenario is performed on each of the smart card semi-finished products by discharging, wherein the discharge voltage conditions matched to the smart card semi-finished products with different numbers are different.
4. The electrostatic withstand capability testing method for smart cards according to claim 3, characterized in that, The step of simulating electrostatic discharge in a lamination scenario for each of the smart card semi-finished products includes: In ascending order of their numbers, each of the smart card semi-finished products is sequentially subjected to human body discharge mode and machine discharge mode. The discharge voltage for the smart card semi-finished product with the first number is 2000V in human body discharge mode and 1000V in machine discharge mode. The discharge voltage for each subsequent smart card semi-finished product is increased by at least one voltage level in human body discharge mode and / or by at least one voltage level in machine discharge mode compared to the previous smart card semi-finished product. Each voltage level in human body discharge mode is 500V and each voltage level in machine discharge mode is 1000V.
5. The electrostatic withstand capability testing method for a smart card according to claim 4, characterized in that, The process of performing human body discharge mode includes: Discharge the chip area of the smart card semi-finished product three times in human body discharge mode.
6. The electrostatic withstand capability testing method for a smart card according to claim 4, characterized in that, The process of performing machine discharge mode discharge includes: In machine discharge mode, each pin solder joint of the chip of the smart card semi-finished product is discharged once in sequence, with a discharge interval of 10 seconds.
7. The electrostatic withstand capability testing method for a smart card according to claim 4, characterized in that, The performance testing of each of the smart card semi-finished products after stripping is performed to obtain performance test data, including: The smart card semi-finished product undergoes a first electrical performance test. If the first electrical performance test fails, the performance test ends. The smart card semi-finished product that passes the first electrical performance test is subjected to a physical structure test. If it fails the physical structure test, the performance test ends. After subjecting the smart card semi-finished product that has passed the physical structure test to a preset number of temperature change cycles, a second electrical performance test is performed. If the second electrical performance test is not passed, the performance test ends. The smart card semi-finished product that passes the first electrical performance test, the physical structure test, and the second electrical performance test is determined to have passed the performance test.
8. The electrostatic withstand capability testing method for a smart card according to claim 7, characterized in that, The first electrical performance test on the smart card semi-finished product includes: The values of multiple electrical parameters of the smart card semi-finished product are detected to obtain first detection information. The multiple electrical parameters include resonant frequency, quality factor, pin on-resistance, semiconductor device threshold voltage, semiconductor device leakage current, and the IV curve of pulse current and clamping voltage. If any electrical parameter in the first detection information deviates by more than 10% from the electrical parameter in the initial detection information, the smart card semi-finished product is determined to have failed the first electrical performance test; otherwise, the smart card semi-finished product is determined to have passed the first electrical performance test. The initial detection information includes the values of the multiple electrical parameters of the smart card semi-finished product before it is discharged. The physical structure test of the smart card semi-finished product that has passed the first electrical performance test includes: The microscopic imaging system is used to detect whether there are appearance defects in the area where the chip of the smart card semi-finished product is located. If there are appearance defects, the smart card semi-finished product is determined to have failed the physical structure test; otherwise, the smart card semi-finished product is determined to have passed the physical structure test. After subjecting the smart card semi-finished product, which has passed the physical structure test, to a preset number of temperature change cycles, a second electrical performance test is performed, including: After subjecting the smart card semi-finished product that has passed the physical structure test to a preset number of temperature change cycles, the values of the multiple electrical parameters of the smart card semi-finished product are detected to obtain second detection information. If any electrical parameter in the second detection information has an offset of more than 10% relative to the electrical parameter in the initial detection information, the smart card semi-finished product is determined to have failed the second electrical performance test; otherwise, the smart card semi-finished product is determined to have passed the second electrical performance test.
9. The electrostatic withstand capability testing method for a smart card according to claim 7, characterized in that, The determination of the electrostatic discharge tolerance test results for the batch of smart cards to be tested based on the performance test data includes: The smart card semi-finished product that has passed the performance test will be designated as the evaluation sample. The grade of each evaluation sample is determined based on the discharge voltage at which each sample has been discharged. The electrostatic withstand capability test results of the smart card in the batch to be tested are determined based on the grades of all the tested samples.
10. The electrostatic withstand capability testing method for a smart card according to claim 9, characterized in that, The determination of the grade of the evaluation sample based on the discharge voltage that each evaluation sample has undergone discharge includes: If the test sample has received a discharge voltage of less than 10kV under human body discharge mode, and / or the test sample has received a discharge voltage of less than 4kV under machine discharge mode, then the test sample is determined to be a Level 3 test sample. If the test sample has received a discharge voltage of 10kV to 15kV under human body discharge mode and a discharge voltage of 4kV or greater under machine discharge mode, or if the test sample has received a discharge voltage of 10kV or greater under human body discharge mode and a discharge voltage of 4kV to 8kV under machine discharge mode, then the test sample is determined to be a secondary test sample. If the test sample has received a discharge voltage of less than or equal to 15kV under human body discharge mode and a discharge voltage of less than or equal to 8kV under machine discharge mode, then the test sample is determined to be a Level 1 test sample.
11. The electrostatic withstand capability testing method for a smart card according to claim 10, characterized in that, The determination of the electrostatic withstand capability test results for the batch of smart cards to be tested based on the grades of all the evaluated samples includes: If none of the secondary evaluation samples and none of the primary evaluation samples are present among all the evaluation samples, then the electrostatic withstand capability test result of the smart card in the batch to be tested is determined to be unqualified. If the secondary evaluation sample is present in all the evaluation samples, then the electrostatic withstand capability test result of the smart card in the batch to be tested is determined to be qualified; If the first-level evaluation sample is present among all the evaluation samples, then the electrostatic withstand capability test result of the smart card in the batch to be tested is determined to be qualified and excellent.