Whole wafer temperature measurement chip batch test device and automatic test method

Abstract

The invention discloses a whole wafer temperature measuring chip batch testing device and an automatic testing method, and belongs to the technical field of testing devices.The whole wafer temperature measuring chip batch testing device comprises a cooling system, a testing system and a control system, the testing system comprises a vacuum cold box, and the control system comprises a voltage measuring unit; the vacuum cold box is internally provided with a carrier table for placing a wafer to be tested, the carrier table is provided with a probe connecting disc, a probe connecting wire and a vacuum aviation plug, the probe connecting disc is electrically connected with the vacuum aviation plug through the probe connecting wire, the bottom surface of the probe connecting disc is provided with a plurality of gold wire probes, and the gold wire probes are electrically connected with the vacuum aviation plug through the probe connecting wire. The gold wire probes are in one-to-one correspondence with chips on a wafer to be measured, the gold wire probes can be in electric contact with the corresponding chips, and the probe connecting wires are connected to the voltage measuring unit through the matrix switch. According to the method, the consumption of time and resources in the testing process of a single chip is reduced, the testing time is shortened, and the testing efficiency is remarkably improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of testing devices, in particular to a batch testing device for temperature measurement chips of an entire wafer and an automatic testing method. BACKGROUND

[0002] Some temperature measurement sensors suitable for large scientific research systems such as hydrogen liquefaction, helium liquefaction, superconducting equipment, nuclear fusion, aerospace, quantum computing, etc. have extremely high requirements for product reliability, and the core is the temperature measurement chip. Each temperature measurement chip must undergo strict low-temperature performance testing, and only chips that pass the test can be processed and packaged subsequently.

[0003] Currently, the testing of temperature measurement chips usually needs to be performed in a liquid nitrogen (about 77K) and liquid helium (about 4.2K) environment for impact testing, requiring more than 100 cold and hot impact cycles, and the test data must be completely accurate and correct to determine the qualified product.

[0004] The traditional testing method can only test a single chip, and when facing an entire wafer that has not been cut, each chip on the wafer needs to be tested one by one. The testing of a single chip takes a long time, especially when more than 100 cold and hot impact cycles are required, the entire testing process may take tens of days or even longer, and the testing efficiency is extremely low. SUMMARY

[0005] In order to improve the extremely low testing efficiency of temperature measurement chips of an entire wafer, the present application provides a batch testing device for temperature measurement chips of an entire wafer and an automatic testing method.

[0006] The batch testing device for temperature measurement chips of an entire wafer and the automatic testing method provided by the present application adopt the following technical solutions: A batch testing device for temperature measurement chips of an entire wafer, comprising a cooling system, a testing system and a control system, the testing system comprising a vacuum cold box, the control system comprising a voltage measurement unit, a carrier table for placing a wafer to be tested is installed in the vacuum cold box, a probe connection disc, a probe connection lead and a vacuum aviation plug are arranged on the carrier table, the probe connection disc is electrically connected to the vacuum aviation plug through the probe connection lead, a plurality of gold wire probes are arranged on the bottom surface of the probe connection disc, the gold wire probes correspond one-to-one to chips on the wafer to be tested, the gold wire probes can be in electrical contact with the corresponding chips, and the probe connection lead is connected to the voltage measurement unit through a matrix switch.

[0007] By adopting the technical scheme, the probe connecting plate is placed on the surface of the wafer to be tested, the gold wire probe is in one-to-one contact with the electrode of each chip, an electrical connection path is established through the probe connecting wire and the vacuum aviation plug, the wafer to be tested with the connected gold wire probe is placed on the carrier table, the cooling system is used to supply cold to the vacuum cold box, the matrix switch is opened to connect the chip and the voltage measurement unit, and then the voltage value of the chip at the test temperature is detected, so that the chip performance detection of the whole wafer to be tested is completed at one time, the consumption of time and resources in the single chip test process is reduced, the test time is shortened, and the test efficiency is significantly improved.

[0008] Preferably, the vacuum cold box is externally connected with a vacuum pump set, and a top cover is hingedly connected to the top of the vacuum cold box.

[0009] By adopting the technical scheme, the wafer to be tested is placed on the carrier table, the top cover of the vacuum cold box is closed, and the vacuum pump set is started to perform vacuumization on the inside of the vacuum cold box, so that the inside of the vacuum cold box is isolated and heat-insulated from the outside.

[0010] Preferably, the cooling system comprises a liquid helium Dewar and a liquid nitrogen Dewar, a cooling copper pipe is arranged around the periphery of the carrier table, a liquid helium injection inlet and a liquid nitrogen injection inlet are connected to the bottom end of the cooling copper pipe, the liquid helium Dewar is connected to the liquid helium injection inlet through a vacuum pipe, the liquid nitrogen Dewar is connected to the liquid nitrogen injection inlet through a vacuum pipe, a liquid helium electric needle valve is arranged on the liquid helium injection inlet, a liquid nitrogen electric needle valve is arranged on the liquid nitrogen injection inlet, a gas recovery pipe opening is connected to the top end of the cooling copper pipe, and the other end of the gas recovery pipe opening is connected with a recovery gas bag, which is located outside the vacuum cold box.

[0011] By adopting the technical scheme, the liquid helium Dewar and the liquid nitrogen Dewar are respectively connected to the liquid nitrogen injection inlet and the liquid helium injection inlet of the vacuum cold box through vacuum pipes, the injection of liquid nitrogen and liquid helium is respectively controlled through the liquid nitrogen electric needle valve and the liquid helium electric needle valve, the liquid nitrogen or liquid helium enters the cooling copper pipe to reduce the temperature of the carrier table to a corresponding low temperature, and the liquid nitrogen and liquid helium enter the recovery gas bag outside the vacuum cold box through the gas recovery pipe opening after passing through the cooling copper pipe.

[0012] Preferably, a thermometer is embedded on the carrier table, and the control system further comprises a host computer, a deep low-temperature temperature measurement module is arranged on the host computer, and the thermometer is electrically connected with the deep low-temperature temperature measurement module.

[0013] By adopting the technical scheme, the thermometer displays the temperature of the current environment, thereby monitoring the temperature of the carrier table in real time, the thermometer monitors the temperature change of the carrier table in real time, the deep low-temperature temperature measurement module transmits the temperature data to the host computer in real time to form a temperature cycle curve graph and a voltage characteristic curve graph, the temperature cycle curve graph can display the temperature change process of each cycle, and the voltage characteristic curve graph can display the voltage change of a typical chip at different temperatures.

[0014] A batch automatic testing method for whole wafer temperature measurement chips, comprising the following steps: S1, system initialization: starting the control system host for self-checking, the vacuum pump group automatically pumping, the deep low-temperature temperature measurement module for zero point calibration, the matrix switch and the voltage measurement unit executing self-test program, checking the accuracy of the voltage measurement circuit, after the initialization of each system is completed, the control panel displays "READY" state; S2, loading of samples to be tested: the operator takes out and cleans the wafer to be tested, checks the integrity of the wafer to be tested through a precision microscope, connects the gold wire probe, places the wafer to be tested connected with the gold wire probe on the carrier table, closes the top cover, starts the vacuum pump group to continue pumping, until the vacuum degree in the box reaches 10^-4Pa or below; S3, chip voltage test at room temperature: starting voltage measurement through the matrix switch, the control system applies a standard excitation current to each chip, measures the voltage output at room temperature, samples the data and compares with the preset qualified range, and generates a room temperature test report; S4, liquid nitrogen impact test cycle: opening the liquid nitrogen electric needle valve, measuring the voltage of the chip at the liquid nitrogen temperature, and performing voltage test after temperature rising; S5, liquid helium impact test cycle: opening the liquid helium electric needle valve, testing the electrical performance of the chip at the liquid helium temperature, and performing voltage test after temperature rising; S6, cycle test and data statistics: performing liquid nitrogen and liquid helium temperature cycle impact test multiple times, statistically analyzing the cycle results in real time, identifying faulty chips, and performing data analysis; S7, test result determination and report generation: generating a test report, including test basic information, chip distribution statistics, temperature cycle curve graph, voltage characteristic curve graph, detailed information of faulty chips and statistical analysis results; S8, system reset and cleaning: after the test is completed, the control system executes an automatic reset program, takes out the sample and identifies the positions of qualified and unqualified chips, and performs equipment maintenance inspection.

[0015] Preferably, the contact force of the gold wire probe and the chip motor is 10mN-50mN.

[0016] By adopting the technical scheme, the contact force of the gold wire probe and the chip motor is 10mN-50mN, which can ensure good electrical connection and avoid damaging the chip.

[0017] Preferably, in the liquid nitrogen impact test cycle, the cooling rate is controlled at 30K / min, and the qualified judgment range at the liquid nitrogen temperature is set to ±0.5% of the calculated value.

[0018] By adopting the technical scheme, in the liquid nitrogen impact test cycle, rapid cooling can be realized, and the test efficiency is improved.

[0019] Preferably, in the liquid helium impact test cycle, the matrix scanning system measures the voltage with a precision of 0.1μV, and the qualified judgment range at the liquid nitrogen temperature is set to ±5% of the calculated value.

[0020] By adopting the technical scheme, at the liquid helium temperature of 4.2K, the resistance characteristics of the chip change more greatly, the matrix scanning system measures the voltage with higher precision, because the signal change at low temperature is more sensitive, and the test judgment standard is adjusted to ±5% of the calculated expected value, so that the performance reliability of the chip in the extreme low temperature environment is ensured.

[0021] Preferably, before the liquid helium test, the cooling system is first pre-cooled; when the liquid helium supply is started, the temperature of the carrier table is quickly reduced to 4.2K±0.5K, the cooling system uses precise flow control to minimize the consumption of liquid helium, and at the same time, the recovery valve is opened to guide the evaporated helium into the recovery system; after the test is completed, the liquid helium electric needle valve is closed, and the helium recovery program is started.

[0022] By adopting the technical scheme, the evaporated helium is recovered in time, which can reduce the consumption of liquid helium and save costs.

[0023] Preferably, the control software is developed based on the Windows platform, and the deep low temperature temperature measurement module and the matrix switch and voltage measurement unit use 24-bit high precision ADC.

[0024] By adopting the technical scheme, the control software is developed based on the Windows platform, has a friendly user interface and powerful data processing capability, and the deep low temperature temperature measurement module and the matrix switch and voltage measurement unit use 24-bit high precision ADC, which can accurately measure the voltage output of the chip.

[0025] In summary, the present application has at least one of the following beneficial technical effects: The probe connecting plate is placed on the surface of the wafer to be tested, the gold wire probe is in one-to-one contact with the electrode of each chip, the electrical connection path is established through the probe connecting wire and the vacuum aviation plug, then the wafer to be tested with the connected gold wire probe is placed on the carrier table, the cooling system is used to supply cold to the vacuum cold box, then the matrix switch is opened to connect the chip with the voltage measurement unit, and then the voltage value of the chip at the test temperature is detected, the chip performance detection of the whole wafer to be tested is completed at one time, the consumption of time and resources in the single chip test process is reduced, the test time is shortened, and the test efficiency is significantly improved. After the wafer to be tested is placed on the carrier table, the top cover of the vacuum cold box is closed, and the vacuum pump group is started to vacuumize the inside of the vacuum cold box, so that the inside of the vacuum cold box is isolated from the outside for heat preservation. The liquid nitrogen Dewar flask and the liquid helium Dewar flask are connected to the liquid nitrogen injection inlet and the liquid helium injection inlet of the vacuum cold box through vacuum pipes respectively, the injection of liquid nitrogen and liquid helium is controlled through the liquid nitrogen electric needle valve and the liquid helium electric needle valve respectively, the liquid nitrogen or liquid helium enters the cooling copper pipe to reduce the temperature of the carrier table to a corresponding low temperature, and the liquid nitrogen and liquid helium enter the recovery gas bag outside the vacuum cold box through the gas recovery pipe after passing through the cooling copper pipe. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 It is a whole structure schematic diagram of the whole wafer temperature measuring chip batch test device of the embodiment of the present application.

[0027] Figure 2 It is a structure schematic diagram of the carrier table in the whole wafer temperature measuring chip batch test device of the embodiment of the present application.

[0028] Figure 3 It is a structure schematic diagram of the probe connecting plate in the whole wafer temperature measuring chip batch test device of the embodiment of the present application.

[0029] The drawings show that: 1, test system; 11, vacuum cold box; 111, top cover; 12, carrier table; 121, thermometer; 122, cooling copper pipe; 13, vacuum pump group; 14, probe connecting plate; 141, gold wire probe; 15, probe connecting wire; 16, vacuum aviation plug; 2, control system; 21, host computer; 22, voltage measurement unit; 23, deep low temperature temperature measurement module; 3, cooling system; 31, liquid helium Dewar flask; 32, liquid nitrogen Dewar flask; 33, liquid helium injection inlet; 34, liquid nitrogen injection inlet; 35, liquid helium electric needle valve; 36, liquid nitrogen electric needle valve; 37, gas recovery pipe; 38, recovery gas bag. DETAILED DESCRIPTION

[0030] The following will be described in detail in combination with the drawings Figures 1-3 The present application is further described in detail.

[0031] The embodiment of the application discloses a whole wafer temperature measuring chip batch testing device and an automatic testing method.

[0032] Referring to Figure 1 The whole wafer temperature measuring chip batch testing device comprises a cooling system 3, a testing system 1 and a control system 2. The testing system 1 comprises a vacuum cold box 11, and a carrier table 12 for placing a wafer to be tested is arranged in the vacuum cold box 11. A top cover 111 is hingedly connected to the top of the vacuum cold box 11, and a vacuum pump set 13 is connected to the outside of the vacuum cold box 11. After the wafer to be tested is placed on the carrier table 12, the top cover 111 of the vacuum cold box 11 is closed, and the vacuum pump set 13 is started to perform vacuumization on the inside of the vacuum cold box 11, so that the inside of the vacuum cold box 11 is isolated and heat-insulated from the outside.

[0033] Referring to Figure 1 and Figure 2 The control system 2 comprises a host computer 21, and a voltage measuring unit 22 and a deep low-temperature temperature measuring module 23 are arranged on the host computer 21. A thermometer 121 is embedded on the carrier table 12, and the thermometer 121 is electrically connected to the deep low-temperature temperature measuring module 23. The thermometer 121 displays the temperature of the current environment, so that the temperature of the carrier table 12 is monitored in real time. The thermometer 121 monitors the temperature change of the carrier table 12 in real time, and the deep low-temperature temperature measuring module 23 transmits the temperature data to the host computer 21 in real time.

[0034] Referring to Figure 2 and Figure 3 A probe connection disc 14, a probe connection wire 15 and a vacuum aviation plug 16 are arranged on the carrier table 12, and the probe connection disc 14 is electrically connected to the vacuum aviation plug 16 through the probe connection wire 15. A plurality of gold wire probes 141 are arranged on the bottom surface of the probe connection disc 14, and the gold wire probes 141 one-to-one correspond to chips on the wafer to be tested. The gold wire probes 141 can be electrically connected to the corresponding chips, and the probe connection wire 15 is connected to the voltage measuring unit 22 through a matrix switch.

[0035] Referring to Figure 1 and Figure 2 The cooling system 3 comprises a liquid helium Dewar flask 31 and a liquid nitrogen Dewar flask 32, and a cooling copper pipe 122 is arranged around the periphery of the carrier table 12. The bottom end of the cooling copper pipe 122 is connected to a liquid helium injection port 33 and a liquid nitrogen injection port 34, the liquid helium Dewar flask 31 is connected to the liquid helium injection port 33 through a vacuum pipe, and the liquid nitrogen Dewar flask 32 is connected to the liquid nitrogen injection port 34 through a vacuum pipe. A liquid helium electric needle valve 35 is arranged on the liquid helium injection port 33, and a liquid nitrogen electric needle valve 36 is arranged on the liquid nitrogen injection port 34. The top end of the cooling copper pipe 122 is connected to a gas recovery pipe opening 37, the other end of the gas recovery pipe opening 37 is connected to a recovery gas bag 38, and the recovery gas bag 38 is located outside the vacuum cold box 11.

[0036] The liquid nitrogen Dewar 32 and the liquid helium Dewar 31 are connected to the liquid nitrogen injection port 34 and the liquid helium injection port 33 of the vacuum cold box 11 through vacuum pipes respectively, and the injection of the liquid nitrogen and the liquid helium is controlled through the liquid nitrogen electric needle valve 36 and the liquid helium electric needle valve 35 respectively, the liquid nitrogen or the liquid helium enters the cooling copper pipe 122, the temperature of the carrier table 12 is reduced to a corresponding low temperature, and the liquid nitrogen and the liquid helium enter the recovery gas bag 38 outside the vacuum cold box 11 through the gas recovery pipe 37 after passing through the cooling copper pipe 122.

[0037] The implementation principle of the embodiment of the application is as follows: the probe connection disc 14 is placed on the wafer surface, the gold wire probe 141 is in one-to-one contact with the electrode of each chip, the electrical connection path is established through the probe connection wire 15 and the vacuum aviation plug 16, the wafer with the connected gold wire probe 141 is placed on the carrier table 12, the cooling system 3 is used to supply cold to the vacuum cold box 11, the matrix switch is opened, the chip is connected with the voltage measurement unit 22, and then the voltage value of the chip at the test temperature is detected, the performance detection of the chips of the whole wafer is completed at one time, the consumption of time and resources in the single chip test process is reduced, the test time is shortened, and the test efficiency is significantly improved.

[0038] A kind of whole wafer temperature measurement chip batch automatic test method, comprising the following steps: S1, system initialization: The host 21 of the control system 2 is started, the host 21 of the control system 2 starts the self-checking program, and the LED state indicator light on the host 21 of the control system 2 is lit in turn, indicating that each system enters the working state; The vacuum pump group 13 is automatically started, and the vacuum cold box 11 is started to be vacuumized, and the vacuum degree monitoring display shows the current vacuum level in real time; The deep cryogenic temperature measurement module 23 carries out zero point calibration, and the standard thermometer 121 displays the current ambient temperature; The matrix switch and the voltage measurement unit 22 execute the self-test program, check the on-off state of all relay channels and the accuracy of the voltage measurement circuit; After the initialization of each system is completed, the control panel displays "READY" state, indicating that the device can start the test process.

[0039] S2, sample loading Sample preparation stage: the operator takes out the wafer to be tested, performs surface cleaning treatment on the clean bench, ensures that the chip electrode surface is not contaminated, uses a precision microscope to check the integrity of each chip on the wafer to be tested, and records the total number of chips and the initial appearance state; Gold wire probe 141 docking process: the probe connection pad 14 is accurately placed on the surface of the wafer to be tested, and the micro-adjusting mechanism is used to make the gold wire probe 141 in one-to-one contact with the electrodes of each chip. The contact force of the gold wire probe 141 is controlled within the range of 10 mN-50 mN, which ensures good electrical connection and avoids damaging the chip. The electrical connection path is established through the probe connection wire 15 and the vacuum aviation plug 16; Carrier loading: place the wafer to be tested with connected gold wire probes 141 on the carrier table 12, ensure the accurate position of the wafer to be tested through the positioning pin, close the top cover 111 of the vacuum cold box 11, start the vacuum pump set 13 to continue vacuumizing, until the vacuum degree in the box reaches below 10^-4 Pa, at this time the standard thermometer 121 displays the ambient temperature of about 295 K; S3, chip voltage test at room temperature Matrix scanning start: the host 21 of the control system 2 sends instructions to the matrix switch and voltage measurement unit 22 to start the voltage test at room temperature. The matrix switch connects each chip on the wafer to be tested to the voltage measurement circuit in turn according to the preset scanning sequence. Reference data collection: for each chip, the control system 2 applies a standard excitation current (changes the current according to the resistance size), measures the voltage output at room temperature (295 K±2 K), and continuously samples 100 points at a sampling frequency of 1 kHz with a 24-bit high-precision ADC. The average value is taken as the room temperature voltage value of the chip. The test time of each chip is about 0.1 seconds.

[0040] Data processing and judgment: the control system 2 compares the measured voltage value with the preset room temperature qualified range; assuming that the qualified range is 2.500V±0.010V, the chips exceeding this range are marked as "room temperature unqualified", the control system 2 automatically generates a room temperature test report, displays the number of qualified chips, the coordinates of unqualified chips, and identifies the state of each chip on the display screen with different colors; S4, liquid nitrogen impact test cycle Liquid nitrogen injection control: the host 21 of the control system 2 sends an opening instruction to the liquid nitrogen electric needle valve 36, the liquid nitrogen electric needle valve 36 is gradually opened according to the preset program, and the liquid nitrogen enters the cooling copper pipe 122 from the liquid nitrogen Dewar flask 32 through the vacuum heat insulation pipeline, starts to rapidly cool the carrier table 12, and the cooling rate is controlled at 30 K / min to achieve rapid cooling. Temperature monitoring and control: the standard thermometer 121 monitors the temperature change of the carrier table 12 in real time, and the deep low temperature temperature measurement module 23 transmits the temperature data to the control system 2 in real time. When the temperature drops to 77K±1K and stably maintains for 5 minutes, the control system 2 determines that the liquid nitrogen test temperature has been reached. Liquid nitrogen temperature electrical performance test: At the liquid nitrogen temperature, the control system 2 starts the matrix scanning program again to measure the voltage of all chips; due to the large decrease in temperature, the resistance characteristics of the chips change, and the output voltage also changes accordingly; the control system 2 calculates the expected voltage value according to the temperature coefficient formula and compares it with the measured value; the qualified judgment range at the liquid nitrogen temperature is usually set to ±0.5% of the calculated value.

[0041] Temperature rising stage: After the liquid nitrogen test is completed, the liquid nitrogen electric needle valve 36 is closed, and the supply of liquid nitrogen is stopped; the carrier table 12 starts to naturally warm up, and the warming rate is about 20 K / min; when the temperature rises to above 290 K, a voltage test at an intermediate temperature is performed to check the stability of the chips during the temperature cycle; S5, liquid helium impact test cycle Liquid helium precooling preparation: Before the liquid helium test is performed, the cooling system 3 first performs precooling processing; the liquid helium electric needle valve 35 is opened to perform small-flow precooling, so that the temperature of the cooling copper pipe 122 and the related pipeline gradually decreases, thereby avoiding the violent vaporization of liquid helium when it contacts a hot surface; the precooling process lasts for about 10 minutes, and the pipeline temperature is reduced to below 100 K; Liquid helium deep cooling test: The supply of liquid helium is formally started, and the temperature of the carrier table 12 rapidly decreases to 4.2 K±0.5 K; due to the extremely low temperature and high cost of liquid helium, the cooling system 3 adopts precise flow control to minimize the consumption of liquid helium; at the same time, the recovery valve is opened to guide the evaporated helium into the recovery system, and the recovery rate reaches more than 99%; Extremely low temperature electrical performance test: At the 4.2 K liquid helium temperature, the resistance characteristics of the chips change more greatly, and the matrix scanning system performs voltage measurement with higher precision (the measurement precision is improved to 0.1 μV); because the signal change at low temperature is more sensitive, the test judgment standard is adjusted to ±5% of the calculated expected value, thereby ensuring the performance reliability of the chips in an extremely low temperature environment; Liquid helium recovery and temperature rising: After the test is completed, the liquid helium electric needle valve 35 is closed, the helium recovery program is started, and the carrier table 12 starts to slowly warm up; the warming process is divided into three stages: 4.2 K→77 K (natural warming), 77 K→200 K (controlled warming), and 200 K→295 K (natural warming); voltage measurement is performed at each stage to establish a complete temperature-voltage characteristic curve; S6, cycle test and data statistics Multi-cycle impact test: According to the product specification requirements, the control system 2 automatically performs more than 100 liquid nitrogen-liquid helium impact cycles; each complete cycle includes the temperature change process of normal temperature (295 K)→liquid nitrogen (77 K)→normal temperature (295 K)→liquid helium (4.2 K)→normal temperature (295 K); full-chip voltage scanning tests are performed each time the target temperature is reached; Real-time data analysis: Control system 2 calculates the test results of each cycle in real time, establishes a performance database for each chip, and automatically identifies performance deterioration trends. For chips with test results deviating from standard values for multiple consecutive tests, the system marks them as "performance suspicious" in advance. The data analysis module uses statistical methods to calculate the mean, standard deviation, and trend of voltage values for each chip. Fault chip positioning: For chips that fail during cycle testing, control system 2 accurately records the cycle number, temperature conditions, and fault type (such as voltage overrun, open circuit, short circuit, etc.) of the failure. Fault information is displayed in a graphical manner on the wafer map for subsequent analysis and processing. S7, Test result determination and report generation Final qualification: Only if the chip's voltage values at all temperature points remain within the qualified range in all 100 or more impact cycles, it is determined to be a final qualified product. Control system 2 adopts a strict "one vote veto" principle, and any unqualified test will result in the chip being determined as unqualified. Test report generation: Control system 2 automatically generates detailed test reports, including: test basic information (wafer number, test time, operator, etc.); chip distribution statistics (total number, qualified number, unqualified number, and distribution location); temperature cycle curve graph (showing the temperature change process of each cycle); voltage characteristic curve graph (showing the voltage change of a typical chip at different temperatures); fault chip detailed information (fault type, occurrence time, location coordinates); statistical analysis results (qualification rate, main failure mode analysis, etc.). Data storage and traceability: All test data is permanently stored in the control system 2 database, establishing a complete product quality traceability system. Each chip has a unique test record that can be traced back to the specific test time, conditions, and results. S8, System reset and cleaning Test completion processing: After all tests are completed, control system 2 executes an automatic reset program, closes all valves, stops cooling medium supply, and raises the carrier table 12 temperature to room temperature. The matrix switch disconnects all chip connections. The vacuum pump continues to run to maintain the vacuum environment in the cold box for the next test. Sample removal and identification: The operator opens the cold box top cover 111 and carefully removes the completed test wafer. According to the test results, use different colored markers to mark the locations of qualified and unqualified chips on the wafer. The qualified chip area is marked green, and the unqualified chip area is marked red, facilitating subsequent cutting and sorting processes. Device maintenance check: after each batch of wafer test is completed, the control system 2 automatically executes a maintenance check program, the check content includes the contact state of the gold wire probe 141, the sealing performance of the valve, the calibration state of the thermometer 121, the leakage detection of the vacuum system, etc., if the abnormality is found, the control system 2 automatically generates a maintenance reminder, and ensures that the device is always in the best working state.

[0042] The above are preferred embodiments of the present application, and are not intended to limit the protection scope of the present application, therefore: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A batch testing device for temperature-sensing chips on an entire wafer, characterized in that: The application relates to a cooling system (3), a test system (1) and a control system (2), wherein the test system (1) comprises a vacuum cold box (11), the control system (2) comprises a voltage measurement unit (22), a carrier table (12) for placing a wafer to be tested is arranged in the vacuum cold box (11), a probe connection disc (14), a probe connection wire (15) and a vacuum aviation plug (16) are arranged on the carrier table (12), the probe connection disc (14) is electrically connected with the vacuum aviation plug (16) through the probe connection wire (15), a plurality of gold wire probes (141) are arranged on the bottom surface of the probe connection disc (14), the gold wire probes (141) are in one-to-one correspondence with chips on the wafer to be tested, the gold wire probes (141) can be electrically connected with the corresponding chips, and the probe connection wire (15) is connected with the voltage measurement unit (22) through a matrix switch.

2. The batch testing device for temperature measuring chips of a whole wafer according to claim 1, characterized in that: A vacuum pump set (13) is connected to the outside of the vacuum cold box (11), and a top cover (111) is hingedly connected to the top of the vacuum cold box (11).

3. The batch testing device for temperature measuring chips of a whole wafer according to claim 2, characterized in that: The cooling system (3) comprises a liquid helium Dewar (31) and a liquid nitrogen Dewar (32), a cooling copper pipe (122) is arranged around the periphery of the carrier table (12), the bottom end of the cooling copper pipe (122) is connected with a liquid helium injection port (33) and a liquid nitrogen injection port (34), the liquid helium Dewar (31) is connected with the liquid helium injection port (33) through a vacuum pipe, the liquid nitrogen Dewar (32) is connected with the liquid nitrogen injection port (34) through a vacuum pipe, a liquid helium electric needle valve (35) is arranged on the liquid helium injection port (33), a liquid nitrogen electric needle valve (36) is arranged on the liquid nitrogen injection port (34), the top end of the cooling copper pipe (122) is connected with a gas recovery pipe (37), the other end of the gas recovery pipe (37) is connected with a recovery gas bag (38), and the recovery gas bag (38) is located outside the vacuum cold box (11).

4. The batch testing device for temperature measuring chips of a whole wafer according to claim 3, characterized in that: A thermometer (121) is embedded on the carrier table (12), and the control system (2) further comprises a host computer (21), the host computer (21) is provided with a deep low-temperature temperature measurement module (23), and the thermometer (121) is electrically connected with the deep low-temperature temperature measurement module (23).

5. A method for batch automatic testing of whole wafer temperature sensor chips, based on the whole wafer temperature sensor chip batch testing device of claim 4, characterized in that: The application further discloses a test method comprising the following steps: S1, system initialization: the host computer (21) of the control system (2) is started to perform self-checking, the vacuum pump set (13) automatically performs vacuumizing, the deep low-temperature temperature measurement module (23) performs zero-point calibration, the matrix switch and the voltage measurement unit (22) execute a self-test program to check the accuracy of a voltage measurement circuit, and after initialization of each system is completed, a control panel displays a "READY" state; S2, sample loading: an operator takes out a wafer to be tested and cleans the wafer, checks the integrity of the wafer through a precision microscope, connects gold wire probes (141), places the wafer to be tested with the connected gold wire probes (141) on the carrier table (12), closes the top cover (111), starts the vacuum pump set (13) to continue vacuumizing, and until the vacuum degree in the box reaches below 10^-4 Pa. S3, normal temperature chip voltage test: through the matrix switch to start voltage measurement, the control system (2) to each chip applied standard excitation current, measure its voltage output at normal temperature, sample data and compare with the preset range, generate normal temperature test report; S4, liquid nitrogen impact test cycle: open the liquid nitrogen electric needle valve (36), measure the voltage of the chip at the liquid nitrogen temperature, and test the voltage after temperature recovery; S5, liquid helium impact test cycle: open the liquid helium electric needle valve (35), test the electrical performance of the chip at the liquid helium temperature, and test the voltage after temperature recovery; S6, cycle test and data statistics: multiple liquid nitrogen and liquid helium temperature cycle impact test, real-time statistics of each cycle result, identify fault chip, data analysis; S7, test result determination and report generation: generate test report, including test basic information, chip distribution statistics, temperature cycle curve, voltage characteristic curve, fault chip detailed information and statistical analysis result; S8, system reset and cleaning: after completing the test, the control system (2) executes the automatic reset program, takes out the sample and identifies the position of qualified and unqualified chips, and performs equipment maintenance inspection.

6. The method of claim 5, wherein the method further comprises: The contact force of the gold wire probe (141) with the chip motor is 10-50 mN.

7. The method of claim 5, wherein the method further comprises: In the liquid nitrogen impact test cycle, the cooling rate is controlled at 30K / min, and the qualified judgment range at the liquid nitrogen temperature is set to ±0.5% of the calculated value.

8. The method of claim 5, wherein the method further comprises: In the liquid helium impact test cycle, the matrix scanning system measures the voltage with an accuracy of 0.1μV, and the qualified judgment range at the liquid nitrogen temperature is set to ±5% of the calculated value.

9. The method of claim 5, wherein the method further comprises: Before the liquid helium test, the cooling system (3) first performs precooling treatment; when the liquid helium supply is opened, the temperature of the carrier table (12) quickly drops to 4.2K±0.5K, the cooling system (3) uses precise flow control to minimize the consumption of liquid helium, and at the same time, the recovery valve is opened to guide the evaporated helium into the recovery system; after the test is completed, the liquid helium electric needle valve (35) is closed, and the helium recovery program is started. ​ 10. The method of claim 5, wherein the method is characterized by: The control software is developed based on the Windows platform, and the deep low temperature temperature measurement module (23) and the matrix switch and voltage measurement unit (22) use 24-bit high-precision ADC.

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