Test method and test device for infrared array temperature measurement chip

Abstract

The application provides a testing method and testing device for an infrared array temperature measurement chip, wherein the testing method comprises collecting a first ambient temperature ADC value of the chip at a first temperature point T1; collecting a first target ADC-off value of the chip in a state where an excitation light source is turned off; collecting a first target ADC-on value of the chip in a state where the excitation light source is turned on; performing first-level good product judgment according to the first target ADC-off value and the first target ADC-on value; collecting a second ambient temperature ADC value of the chip at a second temperature point T2; calculating an ambient temperature response rate based on the first ambient temperature ADC value, the second ambient temperature ADC value, the first temperature point T1 and the second temperature point T2; and performing second-level good product judgment according to whether the ambient temperature response rate is within a first preset range, so that the chip is subjected to efficient and accurate functional excitation and testing.

Description

Technical Field

[0001] This invention relates to the field of semiconductor testing technology, and in particular to a testing method and testing device for an infrared array temperature measurement chip. Background Technology

[0002] An infrared array temperature measurement chip (hereinafter referred to as the chip) highly integrates multiple infrared sensing units (pixels), ambient temperature sensing units, digital-to-analog signal conversion units, and signal processing units onto a single chip. Its core function is to achieve non-contact temperature measurement and thermal imaging. As the core component of an infrared array sensor, the performance of this chip directly determines the accuracy and reliability of the final product. However, due to the complex microbridge structure design, the difficulty of precision etching processes, and the influence of multi-element integration, the yield rate of the chip in manufacturing is generally not high.

[0003] Currently, before chip packaging, quality control tests such as electrical performance are required. However, traditional testing methods can only perform basic electrical performance tests (such as open circuit, short circuit, and quiescent current), lacking a standard infrared excitation source and temperature control environment integrated into the testing system that can simulate real working conditions. This makes it difficult to perform efficient and accurate functional excitation and testing of infrared array temperature measurement chips at the wafer level. Summary of the Invention

[0004] The purpose of this invention is to address the shortcomings of existing technologies by providing a testing method and device for infrared array temperature measurement chips. It provides a standard infrared excitation source and temperature control environment to perform efficient and accurate functional excitation and testing of infrared array temperature measurement chips at the wafer level, thereby preventing defective products from flowing into the back-end packaging process and causing huge cost waste and yield loss.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] The testing method for infrared array temperature sensing chips includes the following steps:

[0007] The chip is fixed on the temperature control workbench, and the temperature control workbench is stabilized at the first temperature point T1.

[0008] Collect the first ambient temperature ADC value of the chip at the first temperature point T1;

[0009] With the excitation light source off, the first target ADC-off value of the chip is acquired;

[0010] With the excitation light source on, the first target ADC-on value of the chip is acquired;

[0011] Based on the first target ADC-off value and the first target ADC-on value, a first-level good product judgment is performed, and the chip is marked based on the first-level good product judgment result;

[0012] Stabilize the temperature-controlled workbench to the second temperature point T2;

[0013] Collect the second ambient temperature ADC value of the chip at the second temperature point T2;

[0014] Calculate the ambient temperature response rate based on the first ambient temperature ADC value, the second ambient temperature ADC value, the first temperature point T1, and the second temperature point T2.

[0015] Based on whether the ambient temperature response rate is within a first preset range, a second-level good product judgment is performed, and the chip is marked according to the result of the second-level good product judgment.

[0016] In a preferred embodiment, after the step of acquiring the first ambient temperature ADC value, the method further includes:

[0017] Determine whether the first ambient temperature ADC value is within a second preset range;

[0018] If not, the chip will be marked as defective, and subsequent testing steps will be terminated.

[0019] In a preferred embodiment, after stabilizing the temperature-controlled workbench to the first temperature point T1 and before acquiring the first ambient temperature ADC value, the method further includes:

[0020] The chip was subjected to electrical performance testing;

[0021] If the electrical performance test fails, the chip will be marked as defective and subsequent testing steps will be terminated.

[0022] If the electrical performance test passes, then proceed with the step of acquiring the first ambient temperature ADC value.

[0023] In a preferred embodiment, the step of performing the first-level good product judgment includes:

[0024] Determine whether the difference between the first target ADC-on value and the first target ADC-off value is within a third preset range;

[0025] If not, then mark the current chip as defective.

[0026] In a preferred embodiment, the formula for calculating the ambient temperature response rate is:

[0027] Ambient temperature response rate = (second ambient temperature ADC value - first ambient temperature ADC value) / (second temperature point T2 - first temperature point T1).

[0028] In a preferred embodiment, the steps for determining the second-level good product include:

[0029] Determine whether the ambient temperature response rate is within the fourth preset range;

[0030] If not, the chip is marked as defective.

[0031] In a preferred embodiment, after stabilizing the temperature-controlled workbench to the second temperature point T2, the method further includes:

[0032] With the excitation light source off, the second target ADC-off value of the chip is acquired;

[0033] With the excitation light source on, the second target ADC-on value of the chip is acquired.

[0034] In a preferred embodiment, the step of acquiring the second target ADC-on value of the chip when the excitation light source is turned on includes:

[0035] After the excitation light source is turned on, the characteristic value of the response intensity of the chip is obtained;

[0036] Determine whether the feature value is within a preset valid range. If not, mark the chip as defective; if yes, proceed with the step of acquiring the second target ADC-on value of the chip.

[0037] In a preferred embodiment, after the second-level good product determination, the method further includes:

[0038] The responsivity of each infrared sensing unit on the chip is calculated based on the first target ADC-off value, the first target ADC-on value, the second target ADC-off value, and the second target ADC-on value.

[0039] The number of sensing units whose response rate exceeds the allowable range;

[0040] If the quantity exceeds a predetermined threshold, the chip will be marked as defective.

[0041] A testing apparatus for an infrared array temperature sensing chip that implements the above-described method includes:

[0042] A temperature-controlled workbench is used to hold the chip and provide it with a stable temperature environment.

[0043] The test assembly includes an excitation light source, a control board, and test probes. The excitation light source is positioned above the temperature-controlled workbench and is used to provide infrared radiation to the chip. The control board is located between the excitation light source and the temperature-controlled workbench and has a light-transmitting hole for the infrared radiation to pass through. The test probes are electrically connected to the control board and are used to contact the solder pads of the chip for communication.

[0044] Compared with existing technologies, this technical solution has the following advantages:

[0045] By introducing a high-precision temperature-controlled stage and infrared excitation light source, comprehensive verification of the infrared sensing function of the infrared array chip was achieved, fundamentally preventing functionally defective products from entering the packaging process. Through a multi-level judgment process including electrical performance testing, ambient temperature sensor testing, and pixel consistency testing, and by progressively screening from easy to difficult and from overall to specific aspects, defective products were quickly eliminated, greatly improving testing efficiency and reducing the testing cost per chip. By testing at both high and low temperatures, the temperature coefficient was accurately calculated, ensuring that the chip maintains good performance consistency and measurement accuracy across the entire temperature range, thus improving the reliability and market competitiveness of the final product. Attached Figure Description

[0046] Figure 1 This is a flowchart of the testing method for the infrared array temperature measurement chip described in this invention;

[0047] Figure 2 This is a schematic diagram of the test device for the infrared array temperature measurement chip described in this invention.

[0048] In the diagram: 100 Test device, 110 Temperature control workbench, 120 Test assembly, 121 Control board, 121a Light transmission hole, 122 Test probe, 123 Excitation light source, 124 Filter, 125 Support, 126 Insulation cover, 200 Wafer. Detailed Implementation

[0049] The following description is intended to disclose the present invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art. The basic principles of the invention defined in the following description can be applied to other embodiments, modifications, improvements, equivalents, and other technical solutions that do not depart from the spirit and scope of the invention.

[0050] First Embodiment

[0051] Please refer to Figure 1 The present invention provides a testing method for an infrared array temperature measurement chip, comprising the following steps:

[0052] S1. Fix the chip on the temperature control workbench and stabilize the temperature control workbench at the first temperature point T1;

[0053] S3. Collect the first ambient temperature ADC value of the chip at the first temperature point T1;

[0054] S5. With the excitation light source off, acquire the first target ADC-off value of the chip;

[0055] S6. With the excitation light source on, acquire the first target ADC-on value of the chip;

[0056] S7. Based on the first target ADC-off value and the first target ADC-on value, perform a first-level good product judgment, and mark the chip based on the first-level good product judgment result;

[0057] S8. Stabilize the temperature-controlled workbench to the second temperature point T2;

[0058] S9. Collect the second ambient temperature ADC value of the chip at the second temperature point T2;

[0059] S11. Calculate the ambient temperature response rate based on the first ambient temperature ADC value, the second ambient temperature ADC value, the first temperature point T1, and the second temperature point T2.

[0060] S12. Based on whether the ambient temperature response rate is within the first preset range, a second-level good product judgment is performed, and the chip is marked according to the result of the second-level good product judgment.

[0061] By constructing a controllable testing environment through the temperature-controlled workbench and introducing an excitation light source, the traditional testing mode, which can only perform electrical performance tests, is solved, and wafer-level functional testing of infrared array temperature measurement chips is realized.

[0062] In step S1, the chip is fixed on the temperature-controlled worktable, which can be done by vacuum adsorption or mechanical clamps to ensure the chip is secure.

[0063] The temperature-controlled stage consists of an external heating and cooling unit, a liquid circulation unit, and a high thermal conductivity heat dissipation component. The liquid circulation unit can use silicone oil as the heat transfer medium, and the high thermal conductivity heat dissipation component is made of materials such as aluminum or copper. The temperature control stage has a temperature range of -40℃ to 150℃ and a temperature control accuracy of ±0.1℃, providing a stable and precise temperature environment for the chip, eliminating test errors caused by ambient temperature fluctuations, and laying the foundation for subsequent accurate measurements.

[0064] After the chip is fixed on the temperature-controlled stage, the stage is stabilized to a first temperature point T1 (e.g., 0°C) to provide a stable and accurate temperature environment for subsequent chip testing at temperature T1. Temperature is a key parameter affecting chip performance, and a stable temperature is a prerequisite for accurate testing.

[0065] After the chip is fixed on the temperature-controlled workbench, the test component is moved onto the temperature-controlled workbench so that the test probes of the test component contact the pads of the chip to establish an electrical connection, providing a path for subsequent power supply and signal acquisition.

[0066] After step S1 and before step S3, the method further includes S2:

[0067] The chip was subjected to electrical performance testing;

[0068] If the electrical performance test fails, the chip will be marked as defective and subsequent testing steps will be terminated.

[0069] If the electrical performance test passes, then proceed with the step of acquiring the first ambient temperature ADC value.

[0070] The electrical performance tests include open circuit, short circuit, quiescent current, and digital circuit kinetic energy. This step can detect obvious hardware defects very early. If a defect fails, it is immediately marked as defective and the test is terminated, which greatly improves the overall testing efficiency and avoids unnecessary infrared testing on defective chips.

[0071] By contacting the test probes with the chip's pads, a path is established for electrical performance testing. For example, a voltage is applied to the chip's pads through the test probes, and the current flowing into the pads is measured using the measurement unit of the test assembly. If the current value is too high, it indicates that there may be defects such as short circuits inside the chip.

[0072] In step S3, the control board of the test component sends a command to the chip via the test probe. This command drives the internal ambient temperature sensing unit of the chip to perform measurements. After receiving the command, the chip's internal ambient temperature sensing unit starts working, and its output is fed into the chip's analog front-end. The conditioned analog signal is sent to the chip's internal analog-to-digital converter to convert the analog signal into digital code, i.e., the first ambient temperature ADC value. After the conversion is complete, the control board initiates a read operation again via the digital interface. The chip outputs the first ambient temperature ADC value stored in the register through the digital interface. The first ambient temperature ADC value is received and recorded by the control board via the test probe. The pads are the physical access points of the chip, and the digital interface is the communication protocol running on these access points. The acquisition process of the second ambient temperature ADC value is the same as that of the first ambient temperature ADC value.

[0073] The first ambient temperature ADC value serves as a calibration reference point, preparing data for calculating core performance parameters (response rate, etc.).

[0074] Following step S3, the method further includes step S4:

[0075] Determine whether the first ambient temperature ADC value is within a second preset range;

[0076] If not, the chip will be marked as defective, and subsequent testing steps will be terminated.

[0077] The second preset range includes non-zero, non-maximum, and non-overflow values. If the first ambient temperature ADC value is not within the second preset range, it indicates that the chip itself, its analog front-end, or the ADC circuit is faulty, and no further testing is required; it is directly marked as a defective product. If the first ambient temperature ADC value is within the second preset range, then step S5 is executed.

[0078] In step S5, with the excitation light source off, the control board sends a command to acquire the output value of the infrared sensing unit inside the chip, which is used as the first target ADC-off value. The first target ADC-off value reflects the thermal radiation intensity of the ambient environment in which the chip is located.

[0079] It should be noted that the ambient temperature sensing unit is a contact type, measuring the chip's own temperature. The infrared sensing unit, on the other hand, is a non-contact type, measuring ambient background thermal radiation. Specifically, the control board sends specific commands to the chip via the test probe and the chip's digital interface. These commands operate on the chip's internal infrared sensing unit. The chip's infrared sensing unit only receives thermal radiation from the test environment and converts the infrared radiation signal into an electrical signal. This signal is then processed and filtered by the chip's internal analog front-end. The processed analog signal is then sent to the chip's internal analog-to-digital converter (ADC) for conversion. After conversion, the control board initiates a read operation again via the digital interface. The chip converts the ADC signal into a digital code output, which the control board receives via the test probe and records as the first target ADC-off value.

[0080] The acquisition process of the first target ADC-on value, the second target ADC-off value, and the second target ADC-on value is the same as that of the first target ADC-off value.

[0081] In step S6, the excitation light source is turned on to emit infrared radiation of a specific wavelength, and other interfering light is filtered out by the infrared filter so that infrared light of a specific band reaches the chip.

[0082] The infrared filter is a bandpass filter with a transmission wavelength of 5–14 μm. It is used to filter out radiation of non-target wavelengths from the excitation light source. The excitation light source emits infrared radiation after being powered on; optional types include tungsten filament lamps, PTC heating elements, electric heating wires, or semiconductor heating elements. It operates by being activated upon power-on and deactivated upon power-off, generating specific infrared radiation to excite the chip as needed.

[0083] After the light source stabilizes, the first target ADC-on value of the chip is collected. This value includes both ambient radiation and excitation signal.

[0084] In step S7, a first-level good product judgment is performed based on the first target ADC-off value and the first target ADC-on value.

[0085] The steps for determining the first-level good quality include:

[0086] Determine whether the difference between the first target ADC-on value and the first target ADC-off value is within a third preset range;

[0087] If not, then mark the current chip as defective.

[0088] The third preset range is derived statistically from tests conducted on known, well-functioning chips under identical test conditions (including ambient temperature, excitation light source power, and the same distance). If the difference is less than the lower limit of the third preset range, it indicates that the chip's response to infrared excitation is too weak, possibly due to sensor unit failure, low sensitivity, or optical channel blockage. If the difference is greater than the upper limit of the third preset range, it indicates that the chip's response is too strong or unstable, possibly due to a short circuit in the sensor unit, abnormal signal processing circuitry, or other interference.

[0089] This judgment step can quickly screen out chips with abnormal responses, avoid wasting subsequent testing resources, and improve overall testing efficiency.

[0090] In step S8, the temperature control stage is stabilized to a second temperature point T2. The purpose of this step is to provide the chip with a stable and accurate testing environment that has a significant temperature difference from the first temperature point T1. By testing the ambient temperature sensing unit at two different temperature points, its temperature coefficient can be calibrated or its performance as a function of temperature can be evaluated.

[0091] In step S9, the second ambient temperature ADC value of the chip is acquired at the second temperature point T2. The purpose of this step is to obtain the reading of the chip's ambient temperature sensing unit at the second temperature point T2. The second ambient temperature ADC value is jointly calculated with the first ambient temperature ADC value read at the first temperature point T1 to evaluate the performance consistency, linearity, and temperature coefficient of the ambient temperature sensing unit itself.

[0092] Between steps S9 and S11, the method further includes step S10:

[0093] With the excitation light source off, the second target ADC-off value of the chip is acquired;

[0094] The excitation light source is activated, and the second target ADC-on value of the chip is acquired while the excitation light source is on.

[0095] The purpose of step S10 is to screen chips with poor thermal stability and to provide data for the subsequent calculation of the response rate of the infrared sensing unit.

[0096] For example, some chips may test normally at the first temperature point T1, but their performance will degrade drastically at high or low temperatures. By comparing the response difference between the first temperature point T1 and the second temperature point T2, chips with such unacceptable temperature characteristics can be effectively screened out. Specifically, at the first temperature point T1, the response difference ΔV1 = ADC1-on - ADC1-off, where ADC1-on is the first target ADC-on value and ADC1-off is the first target ADC-off value. At the second temperature point T2, the response difference ΔV2 = ADC2-on - ADC2-off, where ADC2-on is the second target ADC-on value and ADC2-off is the second target ADC-off value.

[0097] Data is collected at two temperature points: the first target ADC-on value, the first target ADC-off value, the second target ADC-on value, and the second target ADC-off value, to provide necessary data for subsequent calculation of ambient temperature response rate.

[0098] Furthermore, the process of acquiring the second target ADC-on value of the chip when the excitation light source is turned on includes an efficient pre-judgment mechanism, specifically including:

[0099] After the excitation light source is turned on, the characteristic value of the response intensity of the chip is obtained;

[0100] Determine whether the feature value is within a preset valid range. If not, mark the chip as defective; if yes, proceed with the step of acquiring the second target ADC-on value of the chip.

[0101] After the excitation light source is turned on, the control board sends a command to the chip through the digital interface to trigger its ADC to perform one or more fast samplings. The control board randomly reads the sampled value or calculates the average value of multiple fast samples as a characteristic value of the response intensity.

[0102] The control board compares the feature value with the pre-qualified range. If the feature value is not within the valid range, it indicates that the chip has no response to the stimulus or responds abnormally. The chip is then marked as defective, and the test is terminated, saving a significant amount of time. If the feature value is within the preset valid range, it indicates that the chip responds normally to the stimulus, and the step of acquiring the chip's second target ADC-on value is then executed.

[0103] In step S11, the ambient temperature response rate is calculated based on the first ambient temperature ADC value, the second ambient temperature ADC value, the first temperature point T1, and the second temperature point T2.

[0104] Calculating the ambient temperature response rate aims to quantitatively evaluate the performance of the ambient temperature sensing unit itself. A stable and reliable ambient temperature sensing unit should have a linear, consistent response rate that meets design expectations. If the response rate is too large within the normal range, it indicates a defect in the ambient temperature sensing unit, which can cause the overall temperature measurement function of the chip to fail.

[0105] The formula for calculating the ambient temperature response rate is:

[0106] Ambient temperature response rate = (second ambient temperature ADC value - first ambient temperature ADC value) / (second temperature point T2 - first temperature point T1).

[0107] In step S12, a second-level good product judgment is performed based on whether the ambient temperature response rate is within a first preset range, and the chip is marked based on the result of the second-level good product judgment.

[0108] The steps for determining the second level of good quality include:

[0109] Determine whether the ambient temperature response rate is within the fourth preset range;

[0110] If not, the chip is marked as defective.

[0111] In one embodiment:

[0112] The first temperature point T1 = 0℃, and the first ambient temperature ADC value is 14000;

[0113] The second temperature point T2 = 60℃, and the second ambient temperature ADC value is 20000.

[0114] The calculation process is as follows: Ambient temperature response rate = (20000-14000) / (60-0) = 100 LSB / ℃. The physical meaning of this calculation result is that the sensitivity of the ambient temperature sensing unit of this chip is 100 LSB / ℃. That is, for every 1℃ increase in ambient temperature, its ADC output value increases by approximately 100.

[0115] Assuming that the fourth preset range is [90, 100] LSB / ℃ based on the design specifications and yield statistics, and the calculated ambient temperature response rate is 100 LSB / ℃, which falls within the fourth preset range, this test is passed, and the chip can be marked as a good product.

[0116] If another chip is tested under the same conditions, the following results are obtained:

[0117] The first temperature point T1 = 0℃, and the first ambient temperature ADC value is 14000;

[0118] The second temperature point T2 = 60℃, and the second ambient temperature ADC value is 18000.

[0119] Therefore, its ambient temperature response rate = (18000-14000) / (60-0) ≈ 66.67 LSB / ℃.

[0120] Since 66.67 < 90, which is far below the lower limit of the fourth preset range, it indicates that the sensitivity of the ambient temperature sensing unit of the chip is abnormally low, and the chip is marked as a defective product.

[0121] Following step S12, the method further includes step S13:

[0122] The responsivity of each infrared sensing unit on the chip is calculated based on the first target ADC-off value, the first target ADC-on value, the second target ADC-off value, and the second target ADC-on value.

[0123] The number of sensing units whose response rate exceeds the allowable range;

[0124] If the quantity exceeds a predetermined threshold, the chip will be marked as defective.

[0125] The formula for calculating the responsivity of the infrared sensing unit (pixel) is as follows:

[0126] The responsivity of the infrared sensing unit = (ΔV2 - ΔV1) / (T2 - T1);

[0127] ΔV1 = ADC1-on - ADC1-off, where ADC1-on is the first target ADC-on value and ADC1-off is the first target ADC-off value. ΔV2 = ADC2-on - ADC2-off, where ADC2-on is the second target ADC-on value and ADC2-off is the second target ADC-off value.

[0128] Calculate the average rate at which the sensitivity of each pixel changes with ambient temperature, typically measured in LSB / °C. A well-performing and stable pixel should have a responsivity within a reasonable range. An abnormal responsivity indicates that the pixel's performance changes drastically with ambient temperature, leading to inaccurate temperature measurements.

[0129] The response rate of each infrared sensing unit is calculated using the formula for the response rate of the infrared sensing unit. The response rate of each infrared sensing unit is compared with a preset allowable range. If the response rate of an infrared sensing unit exceeds the preset allowable range, the infrared sensing unit is marked as an abnormal pixel.

[0130] Count the total number of pixels marked as abnormal on the entire chip. If the total number of abnormal pixels exceeds a predetermined threshold (e.g., a maximum of 5 bad pixels are allowed), the entire chip is marked as defective.

[0131] After step S13, the method further includes:

[0132] The control board manages all test data for each chip (such as ambient temperature ADC value, target ADC value, calculated response rate, etc.) and the final judgment structure and the chip's unique identifier (such as its coordinates on the wafer), and stores them in the test data file.

[0133] Based on the above judgment results, the control board assigns a BIN number to each chip. For example, BIN1 represents a good product that has passed all tests. BIN2 represents a product that failed the electrical performance test. BIN3 represents a product that fails the ambient temperature response rate test, etc. The BIN classification provides a direct basis for subsequent failure analysis and can quickly locate problematic links in the production process.

[0134] The control board automatically counts the number of all chips on the current test wafer, as well as the number of chips classified as BIN1 (good). It then calculates the overall yield of the wafer: Yield = (Number of good chips / Total number of chips) x 100%. Simultaneously, it can calculate the yield for different BIN classifications, thereby accurately assessing the stability of different stages in the production process.

[0135] The control board generates a test MAP, also known as a wafer map. This map visually displays the test results of each chip on the entire wafer. By observing the MAP, it is possible to quickly identify any patterns in the distribution of defective products.

[0136] In summary, the introduction of a high-precision temperature-controlled stage and infrared excitation light source into CP testing enables comprehensive verification of the infrared sensing function of infrared array chips, filling the gap in traditional CP testing which can only perform electrical performance testing, and fundamentally preventing functionally defective products from entering the packaging process.

[0137] By employing a multi-level judgment process, including electrical performance testing, ambient temperature sensor testing, and pixel consistency testing, and by screening step by step from easy to difficult and from overall to specific, defective products can be quickly eliminated, greatly improving testing efficiency and reducing the testing cost per chip.

[0138] By testing at both high and low extreme temperatures and accurately calculating the temperature coefficient, the chip maintains good performance consistency and measurement accuracy across the entire temperature range, thereby improving the reliability and market competitiveness of the final product.

[0139] By calculating pixel response rate and counting bad pixels, the uniformity of infrared imaging is strictly guaranteed, meeting the stringent image quality requirements of high-end applications.

[0140] Second Embodiment

[0141] like Figure 2 As shown, a testing device 100 for an infrared array temperature measurement chip used to implement the method described in the first embodiment includes:

[0142] Temperature-controlled workbench 110 is used to hold the chip and provide a stable temperature environment for the chip;

[0143] The test assembly 120 includes a control board 121, a test probe 122, and an excitation light source 123. The excitation light source 123 is located above the temperature-controlled stage 110 and is used to provide infrared radiation to the chip. The control board 121 is located between the excitation light source 123 and the temperature-controlled stage 110. The control board 121 has a light-transmitting hole 121a for the infrared radiation to pass through. The test probe 122 is electrically connected to the control board 121 and is used to contact the solder pads of the chip for communication.

[0144] The wafer 200 has multiple chips, so the wafer 200 is fixed on the temperature-controlled workbench 110, and each chip of the wafer 200 is tested by the test assembly 120.

[0145] The control board 121 is also equipped with four NTC temperature sensors to monitor the uniform temperature of the temperature-controlled workbench 110 when it is heating or cooling, and to trigger the start test.

[0146] like Figure 2 As shown, the test component 120 further includes:

[0147] The control board 121, test probe 122, and excitation light source 123 are disposed inside the heat insulation cover 126, so that the test assembly 120 can move relative to the temperature control workbench 110. At the same time, the heat insulation cover 126 covers the wafer 200 to form a sealed space inside it to ensure the test environment.

[0148] Specifically, the control board 121 is connected to the inner wall of the heat insulation cover 126, the excitation light source 123 is supported above the control board 121 by the bracket 125, and the excitation light source 123 is opposite to the light transmission hole 121a on the control board 121, and the test needle 122 is located below the control board 121.

[0149] The bracket 125 has both a fixing and quick-replacement function, which can ensure that the excitation light source is accurately positioned in the optical path and can also be easily replaced when the light source performance deteriorates, thereby ensuring the continuous and stable operation of the system.

[0150] like Figure 2 As shown, a filter 124 is also provided below the control board 121, and the filter 124 is opposite to the light transmission hole 121a. That is, after the infrared radiation emitted by the excitation light source 123 passes through the light transmission hole 121a, it is filtered out by the filter to remove other interfering light, so that infrared light of a specific wavelength reaches the chip.

[0151] During testing, the test component 120 is moved onto the temperature-controlled workbench 110, so that the test pins 122 of the test component 120 contact the pads of the chip to establish an electrical connection, while the heat insulation cover 126 covers the wafer 200.

[0152] The embodiments described above are only used to illustrate the technical ideas and features of the present invention. Their purpose is to enable those skilled in the art to understand the content of the present invention and implement it accordingly. The scope of patent application of the present invention should not be limited by these embodiments. That is, any equivalent changes or modifications made in accordance with the spirit disclosed in the present invention still fall within the patent scope of the present invention.

Claims

1. A method of testing an infrared array thermography chip, characterized in that, The method comprises the following steps: fixing the chip on a temperature control workbench and stabilizing the temperature control workbench to a first temperature point T1; collecting a first ring temperature ADC value of the chip at the first temperature point T1; collecting a first target ADC-off value of the chip in a state that an excitation light source is turned off; collecting a first target ADC-on value of the chip in a state that the excitation light source is turned on; performing a first-level good product judgment according to the first target ADC-off value and the first target ADC-on value, and marking the chip according to a result of the first-level good product judgment; stabilizing the temperature control workbench to a second temperature point T2; collecting a second ring temperature ADC value of the chip at the second temperature point T2; calculating a ring temperature response rate based on the first ring temperature ADC value, the second ring temperature ADC value, the first temperature point T1 and the second temperature point T2; performing a second-level good product judgment according to whether the ring temperature response rate is within a first preset range, and marking the chip according to a result of the second-level good product judgment.

2. The method of testing an infrared array thermography chip of claim 1, wherein, After the step of collecting the first ring temperature ADC value, the method further comprises: judging whether the first ring temperature ADC value is within a second preset range; if not, marking the chip as a defective product and terminating subsequent test steps.

3. The method of claim 1, wherein the infrared array thermography chip is a focal plane array (FPA) chip. After the step of stabilizing the temperature control workbench to the first temperature point T1 and before the step of collecting the first ring temperature ADC value, the method further comprises: performing an electrical performance test on the chip; if the electrical performance test fails, marking the chip as a defective product and terminating subsequent test steps; if the electrical performance test passes, performing the step of collecting the first ring temperature ADC value.

4. The method of testing an infrared array thermography chip of claim 1, wherein, The step of performing the first-level good product judgment comprises: judging whether a difference between the first target ADC-off value and the first target ADC-on value is within a third preset range; if not, marking the chip as a defective product.

5. The method of testing an infrared array thermography chip of claim 1, wherein, The formula for calculating the ring temperature response rate is: ring temperature response rate = (second ring temperature ADC value - first ring temperature ADC value) / (second temperature point T2 - first temperature point T1).

6. The method of testing an infrared array thermography chip of claim 1, wherein, The step of performing the second-level good product judgment comprises: judging whether the ring temperature response rate is within a fourth preset range; if not, marking the chip as a defective product.

7. The method of testing an infrared array thermography chip of claim 1, wherein, After the step of stabilizing the temperature control workbench to the second temperature point T2, the method further comprises: collecting a second target ADC-off value of the chip in the state that the excitation light source is turned off; collecting a second target ADC-on value of the chip in the state that the excitation light source is turned on.

8. The method of testing an infrared array thermography chip of claim 7, wherein, The step of collecting the second target ADC-on value of the chip in the state that the excitation light source is turned on comprises: after the excitation light source is turned on, acquiring a characteristic value of a response intensity of the chip; judging whether the characteristic value is within a preset valid range, if not, marking the chip as a defective product; if yes, performing the step of collecting the second target ADC-on value of the chip.

9. The method of testing an infrared array thermography chip of claim 1, wherein, After the second-level good product judgment, the method further comprises: According to the first target ADC-off value, the first target ADC-on value, the second target ADC-off value and the second target ADC-on value, a response rate of each infrared sensing unit on a chip is calculated; A number of sensing units whose response rates exceed a permitted range is counted; If the number exceeds a predetermined threshold, the chip is marked as a defective product.

10. A test apparatus for implementing the method according to any one of claims 1 to 9, characterized in that it is an infrared array thermography chip. The application comprises: A temperature control workbench for carrying the chip and providing a stable temperature environment for the chip; A test assembly, the test assembly comprising an excitation light source, a control board and a test pin, the excitation light source being arranged above the temperature control workbench for providing infrared radiation to the chip, the control board being located between the excitation light source and the temperature control workbench, the control board being provided with a light transmission hole for the infrared radiation to pass through, the test pin being electrically connected with the control board for contacting the solder pad of the chip for communication.

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