Method and device for testing infrared array temperature measurement chip

Abstract

The invention provides a test method and a test device for an infrared array temperature measurement chip. The test method comprises the following steps: acquiring a first environment temperature ADC value of the chip at a first temperature point T1; collecting a first target ADC-off value of the chip in a closed state of the excitation light source; collecting a first target ADC-on value of the chip in a state that the excitation light source is turned on; according to the first target ADC-off value and the first target ADC-on value, first-level non-defective product judgment is carried out; acquiring a second environment temperature ADC value of the chip at a second temperature point T2; calculating an environment temperature response rate based on the first environment temperature ADC value, the second environment temperature ADC value, the first temperature point T1 and the second temperature point T2; and according to whether the ambient temperature response rate is within the first preset range, performing second-level non-defective product judgment, and performing efficient and accurate functional excitation and test on the chip.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of semiconductor testing, in particular to a testing method and testing device for an infrared array temperature measurement chip. BACKGROUND

[0002] The infrared array temperature measurement chip (hereinafter referred to as the chip) highly integrates a plurality of infrared sensing units (pixels), a ring temperature sensing unit, a digital-analog signal conversion unit and a signal processing unit in a single chip, and its core function is to realize non-contact temperature measurement and thermal imaging. As a core component of the infrared array sensor, the performance of the chip directly determines the accuracy and reliability of the final product. However, due to the complex micro-bridge structure design, the difficulty of precise etching process and multi-element integration, the yield of the chip in production and manufacturing is generally not high.

[0003] At present, before the chip is packaged, it needs to be tested in the quality control link of electrical performance. However, the traditional test can only perform basic electrical performance test (such as open circuit, short circuit, static current, etc.), lacks a standard infrared excitation source and temperature control environment integrated in the test system which can simulate the real working state, and it is difficult to efficiently and accurately functionally excite and test the infrared array temperature measurement chip at the wafer level. SUMMARY

[0004] The purpose of the present application is to overcome the shortcomings of the prior art, provide a testing method and testing device for an infrared array temperature measurement chip, and provide a standard infrared excitation source and temperature control environment to efficiently and accurately functionally excite and test the infrared array temperature measurement chip at the wafer level, avoid the flow of defective products into the backend packaging link, and cause huge cost waste and yield loss.

[0005] In order to achieve the above purpose, the present application provides the following technical scheme: The testing method for the infrared array temperature measurement chip comprises the following steps: Fix the chip on the temperature control workbench, and stabilize the temperature control workbench to a first temperature point T1; Collect a first ring temperature ADC value of the chip at the first temperature point T1; In the off state of the excitation light source, collect a first target ADC-off value of the chip; In the on state of the excitation light source, collect a first target ADC-on value of the chip; According to the first target ADC-off value and the first target ADC-on value, perform a first level good product judgment, and according to the first level good product judgment result, mark the chip; Stabilize 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.

[0006] As a preferred embodiment, 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.

[0007] As a preferred embodiment, after the temperature-controlled workbench is stabilized 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.

[0008] As a preferred embodiment, the step of performing the first-level good product judgment comprises: judging whether a difference between the first target ADC-on value and the first target ADC-off value is within a third preset range; if not, marking the current chip as a defective product.

[0009] As a preferred embodiment, 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).

[0010] As a preferred embodiment, 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.

[0011] As a preferred embodiment, after the temperature-controlled workbench is stabilized to the second temperature point T2, the method further comprises: collecting a second target ADC-off value of the chip in the off state of the excitation light source; In the state of the excitation light source being turned on, a second target ADC-on value of the chip is collected.

[0012] As a preferred embodiment, the collecting the second target ADC-on value of the chip in the state of the excitation light source being turned on comprises: After the excitation light source is turned on, a characteristic value of the response intensity of the chip is obtained. It is judged whether the characteristic value is within a preset valid range, if not, the chip is marked as a defective product, and if yes, the step of collecting the second target ADC-on value of the chip is executed.

[0013] As a preferred embodiment, after the second level of 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 the chip is calculated. The number of sensing units with a response rate exceeding an allowable range is counted. If the number exceeds a predetermined threshold, the chip is marked as a defective product.

[0014] A testing device for an infrared array temperature measurement chip for implementing the above-mentioned method, comprising: A temperature control workbench for carrying the chip and providing a stable temperature environment for the chip; A testing assembly, the testing assembly comprising an excitation light source, a control board and a testing needle, 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 passing hole for the infrared radiation to pass through, and the testing needle being electrically connected with the control board for contacting the solder pad of the chip for communication.

[0015] Compared with the prior art, the technical solution has the following advantages: The high-precision temperature control workbench and infrared excitation light source are introduced to realize all-round verification of the infrared sensing function of the infrared array chip, and to fundamentally avoid the inflow of functional defective products into the packaging link. Through the multi-level judgment process of electrical performance test, ambient temperature sensor test, pixel consistency test and the like, the defective products are quickly removed through the gradual screening from easy to difficult and from the whole to the local, and the test efficiency is greatly improved, and the test cost of a single chip is reduced. Through the test at the two extreme temperatures of high and low temperatures, the temperature coefficient is accurately calculated to ensure that the chip has good performance consistency and measurement accuracy in the full temperature range, and the reliability and market competitiveness of the final product are improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 A flow chart of a testing method of the infrared array temperature measurement chip according to the present application; Figure 2 A structural schematic diagram of a testing device of the infrared array temperature measurement chip according to the present application.

[0017] In the figure: 100 testing device, 110 temperature control workbench, 120 testing assembly, 121 control board, 121a light transmission hole, 122 testing needle, 123 excitation light source, 124 optical filter, 125 support, 126 heat preservation cover, 200 wafer. DETAILED DESCRIPTION

[0018] The following description is provided to enable any person skilled in the art to practice the application. The preferred embodiments described below are only examples of the application, and other obvious modifications can be made by those skilled in the art. The basic principles defined in the following description can be applied to other embodiments, modifications, improvements, equivalents and other technical solutions without departing from the spirit and scope of the application.

[0019] First embodiment Please refer to Figure 1 The embodiment of the present application provides a testing method of an infrared array temperature measurement chip, comprising the following steps: S1, fixing the chip on the temperature control workbench, and stabilizing the temperature control workbench to a first temperature point T1; S3, collecting a first ring temperature ADC value of the chip at the first temperature point T1; S5, collecting a first target ADC-off value of the chip in the off state of the excitation light source; S6, collecting a first target ADC-on value of the chip in the on state of the excitation light source; S7, 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 the first level good product judgment result; S8, stabilizing the temperature control workbench to a second temperature point T2; S9, collecting a second ring temperature ADC value of the chip at the second temperature point T2; S11, 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; S12, 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 the second level good product judgment result.

[0020] The temperature-controlled workbench builds a controllable test environment, and an excitation light source is introduced, which solves the traditional test mode of only electrical performance test and realizes wafer-level functional test of the infrared array temperature measurement chip.

[0021] In the step S1, the chip is fixed on the temperature-controlled workbench, and vacuum adsorption or a mechanical clamp can be used to ensure the firmness of the chip.

[0022] The temperature-controlled workbench is composed of an external heating and refrigeration unit, a liquid circulation unit and a high-thermal-conductivity heat dissipation component. The liquid circulation unit can use silicon oil as a thermal conductive medium, and the high-thermal-conductivity heat dissipation component is made of aluminum, copper or the like. The temperature-controlled range of the temperature-controlled workbench is -40℃ to 150℃, and the temperature control accuracy is ±0.1℃, which provides a stable and accurate temperature environment for the chip and eliminates the test error caused by the environmental temperature fluctuation, laying a foundation for subsequent accurate measurement.

[0023] After the chip is fixed on the temperature-controlled workbench, the temperature-controlled workbench is stabilized to a first temperature point T1 (for example, 0℃), which provides a stable and accurate temperature environment for subsequent chip test at T1. Temperature is a key parameter affecting the performance of the chip, and stable temperature is a prerequisite for accurate test.

[0024] After the chip is fixed on the temperature-controlled workbench, the test assembly is moved to the temperature-controlled workbench, so that the test needle of the test assembly is in contact with the pad of the chip to establish electrical connection and provide a path for subsequent power supply and signal acquisition.

[0025] After the step S1 and before the step S3, the method further includes S2: The electrical performance test is performed on the chip. If the electrical performance test fails, the chip is marked as a defective product, and the subsequent test steps are terminated. If the electrical performance test passes, the step of collecting the first ring temperature ADC value is performed.

[0026] The electrical performance test includes open circuit, short circuit, static current, digital circuit kinetic energy and the like. This step can find obvious hardware defects at an early stage, and if it fails, the chip is immediately marked as a defective product and the test is terminated, which greatly improves the overall test efficiency and avoids unnecessary infrared test on defective chips.

[0027] The test needle is in contact with the pad of the chip to establish a path for the electrical performance test. For example, the test needle applies voltage to the pad of the chip, and the measurement unit of the test assembly measures the current value flowing into the pad. If the current value is too large, it indicates that there may be a short circuit defect in the chip.

[0028] In the step S3, the control board of the test assembly sends an instruction to the chip through the test needle, which is used to drive the ring temperature sensing unit inside the chip to measure. After the chip receives the instruction, the ring temperature sensing unit inside the chip starts to work, and its output is fed into the analog front end inside the chip. After the conditioned analog signal is sent into the analog-to-digital converter inside the chip, the analog signal is converted into a digital code, i.e. the first ring temperature ADC value. After the conversion is completed, the control board initiates a read operation again through the digital interface, and the chip outputs the first ring temperature ADC value stored in the register through the digital interface. The first ring temperature ADC value is received and recorded by the control board through the test needle. The pads are physical access points of the chip, and the digital interface is a communication protocol running on these access points. The following collection process of the second ring temperature ADC value refers to the first ring temperature ADC value.

[0029] The first ring temperature ADC value serves as a calibration reference point and prepares data for calculating core performance parameters (response rate, etc.).

[0030] After the step S3, the method further comprises S4: determining whether the first ring temperature ADC value is within a second preset range; If not, the chip is marked as a defective product, and the subsequent test steps are terminated.

[0031] The second preset range includes non-0, non-maximum value, and non-overflow value. If the first ring temperature ADC value is not within the second preset range, it means that the chip itself, its analog front end or ADC circuit has a fault, and there is no need to perform subsequent tests, and it is directly marked as a defective product. If the first ring temperature ADC value is within the second preset range, the step S5 is performed.

[0032] In the step S5, in the off state of the excitation light source, the control board sends an instruction to collect the output value of the infrared sensing unit inside the chip as the first target ADC-off value. The first target ADC-off value reflects the thermal radiation intensity of the environment background in which the chip is located.

[0033] It should be noted that the ring temperature sensing unit is contact type, and the measurement object is the temperature of the chip itself. The infrared sensing unit is non-contact type, and the measurement object is the environmental background thermal radiation. That is, the control board sends a specific instruction to the chip through the digital interface of the test pin and the chip, and the operation object of the instruction is the infrared sensing unit inside the chip. The infrared sensing unit of the chip at this time only receives the thermal radiation of the self-test environment, and converts the infrared radiation signal into an electrical signal, which is processed by the analog front end inside the chip and filtered, and the processed analog signal is sent to the analog-to-digital converter inside the chip for conversion. After the conversion is completed, the control board initiates a read operation again through the digital interface, and the chip outputs the digital code converted by the analog-to-digital converter, and the control board receives the data through the test pin and records it as the first target ADC-off value.

[0034] The collection process of the following first target ADC-on value, second target ADC-off value and second target ADC-on value refers to the first target ADC-off value.

[0035] In the step S6, the excitation light source is turned on to emit infrared radiation of a specific wavelength, and other interference light is filtered out through the infrared filter, so that infrared light of a specific waveband reaches the chip.

[0036] The infrared filter uses a band-pass filter, and the transmission waveband is 5-14 μm. It is used to filter out the radiation of non-target wavelength in the excitation light source. The excitation light source can emit infrared radiation after being powered on. The optional types include tungsten filament lamp, PTC heating body, electric heating wire or semiconductor heating element, etc. The working mode is to generate specific infrared radiation to excite the chip as needed.

[0037] After the light source is stable, the first target ADC-on value of the chip is collected, which includes environmental radiation and excitation signal.

[0038] In the step S7, first-level good product judgment is performed according to the first target ADC-off value and the first target ADC-on value.

[0039] The step of performing first-level good product judgment includes: judging whether the difference between the first target ADC-on value and the first target ADC-off value is in a third preset range; If not, the current chip is marked as a defective product.

[0040] The third preset range is based on known good chips under the same test conditions (including ambient temperature, excitation light source power, the same distance) test statistics. If the difference is less than the lower limit of the third preset range, it indicates that the response of the chip to infrared excitation is too weak, which may be caused by sensing unit failure, low sensitivity or optical channel blockage, etc. If the difference is greater than the upper limit of the third preset range, it indicates that the chip response is too strong or unstable, which may be caused by sensing unit short circuit, signal processing circuit abnormality or other interference.

[0041] This judgment step can quickly screen out chips with abnormal response, avoid wasting of subsequent test resources, and improve the overall test efficiency.

[0042] In the step S8, the temperature control workbench is stabilized to a second temperature point T2. The purpose of this step is to provide a stable and accurate test environment for the chip with a significant temperature difference from the first temperature point T1. By testing the ring temperature sensing unit at two different temperature points, the temperature coefficient of the calibrator can be calibrated or its performance with temperature change can be evaluated.

[0043] In the step S9, a second ring temperature ADC value of the chip at the second temperature point T2 is collected. The purpose of this step is to obtain the reading of the ring temperature sensing unit of the chip at the second temperature point T2. The second ring temperature ADC value is combined with the first ring temperature ADC value read at the first temperature point T1 to evaluate the performance consistency, linearity (temperature coefficient) of the ring temperature sensing unit itself.

[0044] Between the step S9 and the step S11, the method further comprises S10: In the off state of the excitation light source, a second target ADC-off value of the chip is collected; The excitation light source is started, and in the on state of the excitation light source, a second target ADC-on value of the chip is collected.

[0045] The purpose of the step S10 is to screen out chips with poor thermal stability and provide data for subsequent response rate calculation of infrared sensing units.

[0046] For example, some chips are tested normally at the first temperature point T1, but their performance will be sharply degraded at high or low temperature. By comparing the response difference at the first temperature point T1 and the second temperature point T2, chips with unqualified temperature characteristics can be effectively screened out. The response difference at the first temperature point T1 is 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. The response difference at the second temperature point T2 is 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.

[0047] Data at two temperature points, i.e., 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, are collected to provide necessary data for subsequent execution of the ambient temperature response rate calculation.

[0048] Further, the process of collecting the second target ADC-on value of the chip in the on state of the excitation light source includes an efficient pre-judgment mechanism, which specifically includes: After the excitation light source is turned on, the characteristic value of the response intensity of the chip is obtained. It is determined whether the characteristic value is within a preset valid range. If not, the chip is marked as a defective product. If yes, the step of collecting the second target ADC-on value of the chip is executed.

[0049] After the excitation light source is turned on, the control board sends instructions to the chip through a digital interface to trigger the ADC to perform one or more fast samplings. The control board randomly reads the sampling value or calculates the average value of multiple fast samplings as the characteristic value of the response intensity.

[0050] The control board compares the characteristic value with the pre-set valid range. If the characteristic value is not within the valid range, it means that the chip has no response or abnormal response to the excitation, and the chip is marked as a defective product and the test is terminated, which saves a lot of time. If the characteristic value is within the preset valid range, it means that the chip has a normal response to the excitation, and the step of collecting the second target ADC-on value of the chip is executed.

[0051] In the 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.

[0052] The calculation of the ambient temperature response rate aims to quantitatively evaluate the performance of the ambient temperature sensing unit itself, and a stable and reliable ambient temperature sensing unit should have a linear, consistent and expected design response rate. If the normal range of the response rate is too large, the surface ambient temperature sensing unit has defects, which will cause the overall temperature measurement function of the chip to fail.

[0053] The formula for calculating the ambient temperature response rate is: Ambient temperature response rate = (second ambient temperature ADC value - first ambient temperature ADC value) / (second temperature point T2 - first temperature point T1).

[0054] In the step S12, according to whether the ambient temperature response rate is within the first preset range, a second level good product judgment is performed, and according to the second level good product judgment result, the chip is marked.

[0055] The step of the second level good product judgment includes: judging whether the ambient temperature response rate is within a fourth preset range; If not, the chip is marked as a defective product.

[0056] In one embodiment: The first temperature point T1 = 0℃, and the first ambient temperature ADC value is 14000; The second temperature point T2 = 60℃, and the second ambient temperature ADC value is 20000.

[0057] The calculation process is: ambient temperature response rate = (20000-14000) / (60-0) = 100 LSB / ℃. The physical meaning of the 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 about 100.

[0058] Suppose that according to the design specifications and good product statistics, the fourth preset range is [90, 100] LSB / ℃. The ambient temperature response rate calculated above is 100 LSB / ℃, which is within the fourth pre-set range, so this test passes, and the chip can be marked as a good product.

[0059] If another chip is measured under the same test conditions: The first temperature point T1 = 0℃, and the first ambient temperature ADC value is 14000; The second temperature point T2 = 60℃, and the second ambient temperature ADC value is 18000.

[0060] Then its ambient temperature response rate = (18000-14000) / (60-0) ≈ 66.67 LSB / ℃.

[0061] And 66.67 < 90, far below the fourth pre-set range lower limit, indicating that the ring temperature sensing unit of the chip is abnormally low in sensitivity, and the chip is marked as defective.

[0062] After the step S12, the method further comprises S13: 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, the response rate of each infrared sensing unit on the chip is calculated. The number of sensing units with response rate exceeding the allowable range is counted. If the number exceeds a predetermined threshold, the chip is marked as defective.

[0063] The formula for calculating the response rate of the infrared sensing unit (pixel) is: The response rate of the infrared sensing unit = (ΔV2 - ΔV1) / (T2-T1). ΔV1 = ADC1-on - ADC1-off, ADC1-on is the first target ADC-on value, and ADC1-off is the first target ADC-off value. ΔV2 = ADC2-on - ADC2-off, ADC2-on is the second target ADC-on value, and ADC2-off is the second target ADC-off value.

[0064] The average rate of change of the sensitivity of each pixel with the ambient temperature is calculated, usually in units of LSB / °C. A good and stable pixel should have a response rate within a reasonable range. Abnormal response rate means that the performance of the pixel will change dramatically with the ambient temperature, resulting in inaccurate final temperature measurement.

[0065] Using the formula for the response rate of the infrared sensing unit, the response rate of each infrared sensing unit is calculated. The response rate of each infrared sensing unit is compared with a pre-set allowable range. If the response rate of the infrared sensing unit exceeds the pre-set allowable range, the infrared sensing unit is marked as an abnormal pixel.

[0066] The total number of all pixels marked as abnormal pixels on the entire chip is counted. If the total number of abnormal pixels exceeds a predetermined threshold (e.g., a maximum of 5 bad pixels is allowed), the chip as a whole is marked as defective.

[0067] After the step S13, the method further comprises: The control board manages all test data (such as ring temperature ADC values, target ADC values, calculated response rates, etc.) and final judgment structures of each chip with the unique identification (such as its coordinates on the wafer) of the chip, and stores them into a test data file.

[0068] According to the above judgment result, the control board assigns a BIN number to each chip. For example, BIN1 represents a good product with all test items passing. BIN2 represents a failed electrical performance test. BIN3 represents an unqualified loop temperature response rate, etc. The BIN classification provides a direct basis for subsequent failure analysis, which can quickly locate the problem link in the production process.

[0069] The control board automatically counts the number of all chips on the current test wafer and the number of chips classified as BIN1 (good product). The total yield of the wafer is calculated: yield = (number of good chips / total number of chips) x 100%. The yield of different BIN classifications can also be calculated to accurately evaluate the stability of different links in the production process.

[0070] The control board generates a test MAP, also known as a wafer map. This map visually presents the test results of each chip on the entire wafer in a visual graph. By observing the MAP, it can be quickly determined whether the distribution of defective products has a regularity.

[0071] In summary, the introduction of high-precision temperature-controlled workbench and infrared excitation light source in CP testing realizes the comprehensive verification of the infrared sensing function of infrared array chips, fills the gap of traditional CP testing which can only perform electrical performance testing, and fundamentally avoids the flow of functional defective products into the packaging link.

[0072] Through multiple judgment processes such as electrical performance testing, loop temperature sensor testing, and pixel consistency testing, the defective products are quickly removed by easy-to-difficult and whole-to-local step-by-step screening, greatly improving the test efficiency and reducing the test cost of single chip.

[0073] By testing at high and low temperatures, the temperature coefficient is accurately calculated to ensure that the chip has good performance consistency and measurement accuracy within the full temperature range, improving the reliability and market competitiveness of the final product.

[0074] Through pixel response rate calculation and bad point statistics, the uniformity of infrared imaging is strictly guaranteed, meeting the stringent requirements of high-end applications for image quality.

[0075] Second embodiment As shown in Figure 2 A test device 100 for an infrared array temperature measurement chip for implementing the method of the first embodiment, comprising: A temperature-controlled workbench 110 for carrying the chip and providing a stable temperature environment for the chip; A test assembly 120 is arranged above the temperature-controlled workbench 110, and comprises a control board 121, test pins 122 and an excitation light source 123. The control board 121 is arranged between the excitation light source 123 and the temperature-controlled workbench 110, and has a light transmission hole 121a. The test pins 122 are electrically connected to the control board 121, and are used to contact the pads of the chips.

[0076] The wafer 200 has a plurality of chips, and the wafer 200 is fixed on the temperature-controlled workbench 110. Each chip of the wafer 200 is tested by the test assembly 120.

[0077] Four NTC temperature sensors are arranged on the control board 121, and are used to monitor the uniform temperature of the temperature-controlled workbench 110, and trigger the test.

[0078] As shown in Figure 2 The test assembly 120 further comprises: A heat preservation cover 126 is arranged in the test assembly 120, so that the test assembly 120 moves relative to the temperature-controlled workbench 110, and the heat preservation cover 126 covers the wafer 200, so that an enclosed space is formed in the heat preservation cover 126, and the test environment is ensured.

[0079] Specifically, the control board 121 is connected to the inner wall of the heat preservation cover 126, the excitation light source 123 is supported by the support 125 above the control board 121, the excitation light source 123 is opposite to the light transmission hole 121a of the control board 121, and the test pins 122 are arranged below the control board 121.

[0080] The support 125 has the functions of fixing and quick replacement, which can ensure that the excitation light source is accurately positioned in the optical path, and can be conveniently replaced when the performance of the light source is degraded, so that the system can continuously and stably operate.

[0081] As shown in Figure 2 The control board 121 further comprises a filter 124 arranged below the control board 121 and opposite to the light transmission hole 121a. That is, the infrared radiation emitted by the excitation light source 123 passes through the light transmission hole 121a, and then the filter filters out other interference light, so that the infrared light of a specific wave band reaches the chips.

[0082] During testing, the test assembly 120 is moved onto the temperature-controlled workbench 110 so that the test pins 122 of the test assembly 120 are in contact with the pads of the chip and an electrical connection is established, while the heat shield 126 covers the wafer 200.

[0083] The above-described embodiments are merely intended to illustrate the technical ideas and characteristics of the present application, and to enable those skilled in the art to understand and implement the present application, and cannot be used to limit the patent application range of the present application, i.e. any equivalent changes or modifications made according to the disclosed spirit of the present application still fall within the patent application range of the present application.

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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