Reflectivity thermal imager test module and test method

Abstract

The present invention relates to the field of semiconductor temperature measurement technology, and discloses a reflectivity thermal imager test module and test method, including a first test sample area, the first test sample area includes a plurality of metal wires arranged at different intervals, each of the metal wires is provided with pads at both ends, and the size of each of the metal wires is the same; a first power module is connected to the pads of any two adjacent metal wires, and is used to provide a first test electrical signal to any two adjacent metal wires. The reflectivity thermal imager test module provided by the present disclosure can be used to test and verify the key indicators of the reflectivity thermal imager, so that the test performance of the reflectivity thermal imager can be further studied and improved.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor temperature measurement technology, and in particular to a reflectivity thermal imager test module and a test method. Background Art

[0002] With the development of aerospace, industrial transportation, 5G communications, and new energy, higher performance and reliability requirements are constantly being put forward for power devices. Temperature data, as a key indicator for power device performance evaluation, is an important basis for power device thermal management, reliability evaluation, and device performance optimization design. As semiconductor devices continue to develop rapidly in the direction of high-speed, high-density, and high-power applications, the testing and verification of integrated circuits also show high time, high space, and high-sensitivity detection requirements.

[0003] Reflectivity thermal imaging technology uses the functional relationship between the reflectivity of light waves of materials and temperature to obtain the temperature distribution of integrated circuit semiconductor devices. In theory, reflectivity thermal imaging test technology can achieve temperature measurement capabilities with a spatial resolution of less than 0.5um, a time resolution of less than 100ns, and a temperature resolution of 0.5°C. It is suitable for sub-micron thermal distribution detection of third-generation half-power devices represented by GaN. However, at this stage, there is little research on the verification of technical indicators of temperature test systems, and there is a lack of test methods for verifying the temperature measurement indicators of reflectivity thermal imaging equipment. Summary of the invention

[0004] Based on this, it is necessary to provide a reflectivity thermal imager test module and test method to address the problem that there is relatively little verification work on the indicators of reflectivity thermal imaging equipment at this stage.

[0005] A reflectivity thermal imager test module comprises a first test sample area, wherein the first test sample area comprises a plurality of metal wires arranged at different intervals, each of the metal wires is provided with pads at both ends, and each of the metal wires has the same size; a first power module is connected to the pads of any two adjacent metal wires, and is used to provide a first test electrical signal to any two adjacent metal wires.

[0006] In the above-mentioned reflectivity thermal imager test module, a metal wire array with different sizes of spacing is arranged in the first test sample area, and the distance between any two adjacent metal wires is different. The shape and size of each metal wire in the metal wire array are the same. The first power module can be connected to any two adjacent metal wires and output a first test electrical signal to the two metal wires. The two metal wires will generate heat due to the first test electrical signal, and the metal wire array will be imaged and identified using a reflectivity thermal imager. According to the identification results of the reflectivity thermal imager for the two metal wires, the spatial resolution of the reflectivity thermal imager is determined. The reflectivity thermal imager test module provided by the present disclosure can be used to test and verify the key indicators of the reflectivity thermal imager, so that the test performance of the reflectivity thermal imager can be further studied and improved.

[0007] In one embodiment, the reflectivity thermal imager test module also includes a second test sample area, the second test sample area includes a preset test interconnect structure, and pads are provided at both ends of the preset test interconnect structure; a second power module is connected to the pads of the preset test interconnect structure, and is used to provide a second test electrical signal to the preset test interconnect structure.

[0008] In one embodiment, the preset test interconnect structure includes a spiral metal interconnect structure.

[0009] In one embodiment, the spiral metal interconnection structure is made of a metal material having a preset thermal expansion coefficient.

[0010] In one embodiment, the reflectivity thermal imager test module also includes a third test sample area, the third test sample area includes a test resistor, and both ends of the test resistor are connected to two pads at a preset distance; a third power module is connected to the pads at both ends of the test resistor, and is used to provide a third test electrical signal to the test resistor.

[0011] A reflectivity thermal imager testing method is applied to the reflectivity thermal imager testing module described in any one of the above embodiments, the method comprising controlling the reflectivity thermal imager to use a first incident light source to irradiate a first test sample area; applying a first test electrical signal to two adjacent metal strips separated by different distances in the first test sample area to heat the two metal strips; controlling the reflectivity thermal imager to focus and image the metal strips in the first test sample area; and judging the spatial resolution of the reflectivity thermal imager based on the minimum distance between two metal lines identified by the reflectivity thermal imager.

[0012] In one embodiment, after the reflectivity thermal imager identifies the minimum distance between two metal lines and determines the spatial resolution of the reflectivity thermal imager, the method further includes controlling the reflectivity thermal imager to use a second incident light source to illuminate a second test sample area; applying a second test electrical signal to a preset test interconnect structure in the second test sample area; changing the value of the second test electrical signal to cause a temperature change in the preset test interconnect structure; controlling the reflectivity thermal imager to determine the temperature change of the preset test interconnect structure; and determining the temperature sensitivity of the reflectivity thermal imager based on the minimum temperature change amplitude of the preset test interconnect structure identified by the reflectivity thermal imager.

[0013] In one of the embodiments, before controlling the reflectivity thermal imager to use a second incident light source to illuminate the second test sample area, the method further includes adjusting the test bench temperature of the reflectivity thermal imager and calibrating a reflectivity calibration coefficient of the reflectivity thermal imager for the preset test interconnect structure; the reflectivity thermal imager calibrates the recognition result of the temperature change according to the reflectivity calibration coefficient.

[0014] In one of the embodiments, after applying a second test electrical signal to a preset test interconnect structure in the second test sample area, the method further includes measuring a first voltage drop across the preset test interconnect structure and calculating a first resistance value of the preset test interconnect structure; after changing the value of the second test electrical signal to cause a temperature change in the preset test interconnect structure, the method further includes measuring a second voltage drop across the preset test interconnect structure and calculating a second resistance value of the preset test interconnect structure; and determining the temperature difference between the two resistance value measurement times based on the relationship between the resistivity of the metal material and the temperature, according to the first resistance value and the second resistance value.

[0015] In one embodiment, after the reflectivity thermal imager identifies the minimum distance between two metal wires and determines the spatial resolution of the reflectivity thermal imager, the method further includes controlling the reflectivity thermal imager to use a third incident light source to illuminate a third test sample area; applying a third test electrical signal to a test resistor in the third test sample area; controlling the reflectivity thermal imager to focus and image the test resistor; changing the value of the third test electrical signal to change the heating power of the test resistor; and determining the hotspot power detection capability of the reflectivity thermal imager based on the minimum heating power at which the reflectivity thermal imager identifies the test resistor as a hotspot. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the implementation methods of this specification or the technical solutions in the prior art, the drawings required for use in the implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some implementation methods recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0017] Figure 1 It is a structural schematic diagram of a reflectivity thermal imager test module according to one embodiment of the present disclosure;

[0018] Figure 2 It is a structural schematic diagram of a second test sample area according to one embodiment of the present disclosure;

[0019] Figure 3 It is a schematic structural diagram of a third test sample area according to one embodiment of the present disclosure;

[0020] Figure 4 This is a schematic diagram of the overall structure of a test module according to one embodiment of the present disclosure;

[0021] Figure 5 A schematic diagram of a method flow of a reflectivity thermal imager testing method according to one embodiment of the present disclosure;

[0022] Figure 6 A schematic diagram of a method for verifying temperature sensitivity according to one embodiment of the present disclosure;

[0023] Figure 7 A timing diagram of a temperature sensitivity test circuit for verifying one embodiment of the present disclosure;

[0024] Figure 8 A schematic flow chart of a method for calculating an actual temperature difference of a preset test interconnect structure according to one embodiment of the present disclosure;

[0025] Fig. 9 A schematic flow chart of a method for verifying hotspot power detection capability according to one embodiment of the present disclosure. DETAILED DESCRIPTION

[0026] In order to facilitate the understanding of the present invention, the present invention will be described more fully below with reference to the relevant drawings. The preferred embodiments of the present invention are given in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to understand the disclosure of the present invention more thoroughly and comprehensively.

[0027] It should be noted that when an element is referred to as being "fixed to" another element, it may be directly on the other element or there may also be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "left", "right", "upper", "lower", "front", "rear", "circumferential" and similar expressions used herein are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0028] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0029] Reflectivity thermal imaging technology uses the functional relationship between the reflectivity of light waves of materials and temperature changes to obtain the temperature distribution of integrated circuit semiconductor devices. However, at present, there is relatively little verification work on the temperature measurement indicators of reflectivity thermal imaging equipment, and the industry has not yet formed a complete testing method.

[0030] In view of the problem that the existing technical solutions only verify the temperature measurement accuracy of reflectivity thermal imaging and lack verification tests on other key indicators of reflectivity thermal imaging equipment, the present disclosure proposes a reflectivity thermal imager test module. Figure 1 1 is a schematic diagram of the structure of a reflectivity thermal imager test module according to one embodiment of the present disclosure. In one embodiment, the reflectivity thermal imager test module includes a first test sample area 100. The first test sample area 100 may include a metal line 110 and a first power module 120. In some embodiments of the present disclosure, the first test sample area 100 may be disposed on a PCB board or a substrate material surface.

[0031] The first test sample area 100 includes a plurality of metal wires 110, which are arranged at different intervals to form a metal wire array. The shape and size of each metal wire 110 in the metal wire array are the same. Since the current reflectivity thermal imaging technology can realize sub-micron thermal distribution detection, the performance of the reflectivity thermal imager is tested using metal wires 110 with a size in the micron order. In some embodiments of the present disclosure, the length of the metal wires 110 is 4000um and the width is 10um.

[0032] Since the metal wires 110 are relatively small in size, it is difficult to connect the metal wires 110 to the first power module 120. Therefore, pads are provided at both ends of each metal wire 110 to facilitate connecting the metal wires 110 to the first power module 120. In some embodiments of the present disclosure, gold (Au) is used as the preparation material of the metal wires 110. In some other embodiments, other metal materials with high conductivity can be used as the preparation material of the metal wires 110. In some embodiments of the present disclosure, gold (Au) or other metal materials with high conductivity can also be used as the preparation material of the pads.

[0033] The first power module 120 can be connected to the pads of any two adjacent metal wires 110 in the metal wire array, and is used to provide a first test electrical signal to any two adjacent metal wires 110. In some embodiments of the present disclosure, the first power module 120 includes a test current source. The power current output by the first power module 120 flows through the two metal wires 110, and the two metal wires 110 will generate heat, so that the reflectivity thermal imager can obtain the temperature distribution on the two metal wires 110 according to the functional relationship between the light wave reflectivity of the material and the temperature. Furthermore, the spatial resolution of the reflectivity thermal imager can be judged according to the imaging effect of the reflectivity thermal imager on the two metal wires 110.

[0034] The distance between any two adjacent metal wires in the metal wire array is different from that between other adjacent metal wires. In some embodiments of the present disclosure, the metal wire array includes 11 metal wires, and the distances between adjacent metal wires are 0.1um, 0.25um, 0.5um, 1um, 2um, 5um, 10um, 25um, 50um, and 100um, respectively. In order to facilitate the tester to record data during the test, the distance between all metal wires can be marked with scales, so that the tester can more conveniently and intuitively determine the distance between two adjacent metal wires under test.

[0035] Based on the principle that spatial resolution is limited by the diffraction limit, the reflectivity thermal imager can be used to image and identify the heat generated by two adjacent metal wires with different spacing distances, and the spatial resolution of the reflectivity thermal imager can be determined based on the recognition effect. For example, when the reflectivity thermal imager can clearly identify the existence of two adjacent metal wires in the image after imaging two metal wires with a spacing of 0.5um, it is determined that the recognition accuracy of the reflectivity thermal imager is less than 0.5um.

[0036] A metal wire array with different spacings is arranged in the first test sample area 100, wherein the distances between any two adjacent metal wires 110 are different, and the shape and size of each metal wire 110 in the metal wire array are the same. A reflectivity thermal imager is used to perform imaging recognition on the metal wire array, and the spatial resolution of the reflectivity thermal imager is determined based on the recognition results of the two metal wires by the reflectivity thermal imager. The reflectivity thermal imager test module provided by the present disclosure can be used to test the spatial resolution of the reflectivity thermal imager, so that the spatial resolution of the reflectivity thermal imager can be further studied and improved based on the verification results.

[0037] Figure 2 1 is a schematic diagram of the structure of the second test sample area of ​​one embodiment of the present disclosure. In one embodiment, the reflectivity thermal imager test module also includes a second test sample area 200. The second test sample area 200 may include a preset test interconnect structure 210 and a second power module 220. In some embodiments of the present disclosure, the second test sample area 200 may be set on the surface of a PCB board or a substrate material.

[0038] Similarly, since the current reflectivity thermal imaging technology can achieve sub-micron-level thermal distribution detection, a preset test interconnect structure 210 with a size in the micron level is used to test the reflectivity thermal imager. Due to the small size of the preset test interconnect structure 210, it is difficult to connect the preset test interconnect structure 210 to the second power module 220. Therefore, pads are provided at both ends of the preset test interconnect structure 210. The input terminal pin at one end of the preset test interconnect structure 210 is connected to a pad, and the output terminal pin at the other end of the preset test interconnect structure 210 is connected to another pad. In some embodiments of the present disclosure, gold (Au) or other metal materials with high conductivity can be used as the preparation material of the pad.

[0039] The second power module 220 can be connected to the pads at both ends of the preset test interconnect structure 210 to provide a second test electrical signal to the preset test interconnect structure 210. In some embodiments of the present disclosure, the second power module 220 includes a power pulse current source and a test pulse current power source. The two pulse current sources are simultaneously connected to the pads of the preset test interconnect structure 210, the test pulse current power source is used to output a smaller current to the preset test interconnect structure 210 to perform a pulse voltage test on the preset test interconnect structure 210, and the power pulse current source is used to output a larger current to the preset test interconnect structure 210 to load a power pulse thereon, thereby heating the preset test interconnect structure 210. According to the principle that the heating conditions of the preset test interconnect structure 210 are different under different powers, the temperature of the preset test interconnect structure 210 can be changed by changing the power current flowing through the preset test interconnect structure 210.

[0040] In some embodiments of the present disclosure, the second test sample area 200 may further include a "four-point method" test circuit, which is used to measure the voltage drop across the preset test interconnect structure 210 and calculate the resistance value of the preset test interconnect structure 210 at a temperature. Based on the linear relationship between the resistivity of metal materials and temperature, the actual temperature change of the preset test interconnect structure 210 can be calibrated according to the resistance change of the preset test interconnect structure 210.

[0041] At the same time, the temperature of the preset test interconnect structure 210 is synchronously monitored using a reflectivity thermal imager, and the temperature sensitivity of the reflectivity thermal imager is determined according to the minimum temperature change range of the preset test interconnect structure 210 that can be monitored by the reflectivity thermal imager. The reflectivity thermal imager test module provided by the present disclosure can be used to test the temperature sensitivity of the reflectivity thermal imager, so that the temperature sensitivity of the reflectivity thermal imager can be further studied and improved based on the verification results.

[0042] In one embodiment, the preset test interconnect structure 210 includes a spiral metal interconnect structure. When the external pressure remains unchanged, the volume of the spiral metal interconnect structure increases when the temperature rises, and the thermal expansion of the spiral metal interconnect structure is positively correlated with the temperature. Therefore, in addition to using the "four-point method" test circuit to measure the voltage drop across the preset test interconnect structure 210 and calculating the resistance value of the preset test interconnect structure 210 at the temperature to determine the resistance change of the preset test interconnect structure 210, the resistance change of the spiral metal can also be calibrated according to the expansion of the volume of the spiral metal interconnect structure, thereby calibrating its actual temperature change.

[0043] In some other embodiments of the present disclosure, the resistance change of the preset test interconnect structure 210 measured in the “four-point method” test circuit may also be verified according to the expansion of the volume of the spiral metal interconnect structure.

[0044] In one embodiment, the spiral metal interconnect structure uses a metal material with a preset thermal expansion coefficient. Using a metal material with a high thermal expansion coefficient as the preparation material of the spiral metal interconnect structure ensures that the change in resistance value of the spiral metal interconnect structure can be accurately calibrated according to the expansion of the spiral metal interconnect structure, thereby facilitating the detection accuracy of the temperature sensitivity of the reflectivity thermal imager.

[0045] Figure 3 1 is a schematic diagram of the structure of the third test sample area of ​​one embodiment of the present disclosure. In one embodiment, the reflectivity thermal imager test module also includes a third test sample area 300. The third test sample area 300 may include a test resistor 310 and a third power module 320. In some embodiments of the present disclosure, the third test sample area 300 may also be arranged on the surface of a PCB board or a substrate material. The two ends of the test resistor 310 are respectively connected to two pads at a preset distance. The third power module 320 is connected to the pads at both ends of the test resistor 310, and is used to provide a third test electrical signal to the test resistor 310.

[0046] In some embodiments of the present disclosure, the test resistor 310 may be a miniature square resistor. Similarly, since the current reflectivity thermal imaging technology can achieve sub-micron thermal distribution detection, a miniature resistor with a size of sub-micron is used to test the reflectivity thermal imager. Due to the small size of the test resistor 310, it is difficult to connect the test resistor 310 to the third power module 320. Therefore, the two ends of the test resistor 310 are connected to the two pads at a preset distance.

[0047] In some embodiments of the present disclosure, the two pads in the third test sample area 300 may be axisymmetric pads. The pads may be made of gold (Au) or other metal materials with high electrical conductivity. The two pads are spaced a certain distance apart, and the test resistor 310 is disposed between the two pads, and the two pads are connected through the test resistor 310.

[0048] When performing a verification test on the hot spot power detection capability of the reflectivity thermal imager, it is necessary to continuously reduce the heat generation power on the test resistor 310 so that the hot spot image presented by the test resistor 310 is continuously reduced, thereby judging its hot spot power detection capability based on the detection result of the reflectivity thermal imager. Therefore, it is necessary to set the test resistor 310 at a suitable distance from the pad to prevent the pad from affecting the test resistor 310, thereby affecting the accuracy of the test result.

[0049] The third power module 320 can be connected to the pads at both ends of the test resistor 310 to provide a third test electrical signal to the test resistor 310. In some embodiments of the present disclosure, the third power module 320 may include a pulse current source. The pulse current output by the third power module 320 to the test resistor 310 causes it to generate heat to form a hot spot. The third power module 320 can control the heating power of the test resistor 310 by changing the current applied to both ends of the test resistor 310, thereby changing the hot spot size of the test resistor 310.

[0050] At the same time, the reflectivity thermal imager is used to perform thermal imaging of the test resistor 310 at different heating powers, and the minimum hot spot detection power of the reflectivity thermal imager is determined according to the hot spot detection situation of the reflectivity thermal imager. Further, the hot spot power detection capability of the reflectivity thermal imager can be judged according to the imaging effect of the reflectivity thermal imager on the two metal wires 110. The reflectivity thermal imager test module provided by the present disclosure can be used to test the hot spot power detection capability of the reflectivity thermal imager, so that the hot spot power detection capability of the reflectivity thermal imager can be further studied and improved based on the verification results.

[0051] The present disclosure proposes a test module for verifying the technical indicators of a reflectivity thermal imager, such as Figure 4 As shown, Figure 4 The overall structure diagram of the test module of one embodiment of the present disclosure is shown in FIG. The test module includes three sample test areas, which can be used to test the spatial resolution, temperature resolution and hot spot detection power of the reflectivity thermal imager.

[0052] By arranging metal wire arrays with different sizes of spacing in the first test sample area 100 in the test module, the spatial resolution of the reflectivity thermal imager can be determined according to the imaging and recognition of the metal wire array by the reflectivity thermal imager.

[0053] A spiral metal interconnect structure is designed in the second test sample area 200 in the test module based on the linear relationship between the resistivity and temperature of the metal material. The actual temperature rise can be calibrated according to the resistance change of the spiral metal. At the same time, the temperature sensitivity of the reflectivity thermal imaging instrument can be determined by combining the temperature rise recognition of the spiral metal interconnect structure by the reflectivity thermal imager.

[0054] In the third test sample area 300 in the test module, two highly conductive pads are connected to the two ends of the micro-resistor, and the hot spot power detection capability of the reflectivity thermal imaging instrument is determined based on the thermal imaging results of the micro-resistor at different heating powers.

[0055] The reflectivity thermal imager test module provided by the present disclosure can solve the problem that key indicators such as spatial resolution, temperature resolution and hot spot detection power of the reflectivity thermal imager in the existing technical solutions are difficult to test and verify.

[0056] The present disclosure also provides a reflectivity thermal imager testing method, which is applied to the reflectivity thermal imager testing module described in any one of the above embodiments. Figure 5 1 is a method flow chart of a reflectivity thermal imager testing method according to one embodiment of the present disclosure. In one embodiment, the reflectivity thermal imager testing method includes the following steps S110 to S140.

[0057] Step S110: controlling the reflectivity thermal imager to use a first incident light source to illuminate a first test sample area.

[0058] The samples to be tested of different materials have different reflection effects on the same incident light source. Therefore, a suitable incident light source can be selected according to the material of the sample to be tested. For example, a light source with a wavelength of 480nm to 530nm is usually selected as the incident light source for gold (Au) material. The first incident light source is selected based on the material of the metal wire array, and the first test sample area 100 of the reflectivity thermal imager test module is placed in the test area of ​​the reflectivity thermal imager, and the first incident light source is used to illuminate the first test sample area 100.

[0059] Step S120: applying a first test electrical signal to two adjacent metal strips spaced at different distances in the first test sample area to heat the two metal strips.

[0060] Step S130: controlling the reflectivity thermal imager to focus on and image the metal strips in the first test sample area.

[0061] Step S140: determining the spatial resolution of the reflectivity thermal imager according to the minimum distance between two metal lines identified by the reflectivity thermal imager.

[0062] The first power module 120 can be connected to the pads of any two metal wires 110 in the metal wire array to output the first test electrical signal to the two metal wires 110. The power current output by the first power module 120 flows through the two metal wires 110, and the two metal wires 110 will generate heat, so that the reflectivity thermal imager can determine the temperature distribution on the two metal wires 110 according to the functional relationship between the light wave reflectivity of the material and the temperature change, thereby obtaining a thermal imaging picture. When using the reflectivity thermal imager to focus on the first test sample area 100 for imaging, the lens with the highest magnification can be selected.

[0063] In one embodiment, the test can be started from the two adjacent metal wires with the farthest adjacent spacing, and gradually moved to the two adjacent metal wires with the closest adjacent spacing. The first power module 120 can output a first test electrical signal to two metal wires 110 with a spacing of 100um. Use the highest magnification lens to image the first test sample area 100. If the thermal imaging picture obtained by focusing the equipment can clearly identify that there are two adjacent metal wires 110 in the picture, the first power module 120 is allowed to output a first test electrical signal to the two metal wires 110 with a spacing of 50um. Adjust the position of the test platform or move the detector position of the reflectivity thermal imager, and focus imaging observations from the two metal wires with an adjacent spacing of 100um to the two metal wire areas with an adjacent spacing of 0.1um step by step.

[0064] Repeat the above steps until the boundary between the two metal wires 110 in the thermal imaging image acquired by focusing the device is no longer obvious, and the two adjacent metal wires 110 in the image cannot be identified, then it is determined that the spatial resolution of the device is greater than the spacing between the two metal wires 110 at this time.

[0065] For example, when the distance between the two metal wires 110 that the first power module 120 outputs the first test electrical signal is 2um, the thermal imaging image obtained by the reflectivity thermal imager can identify that there are two adjacent metal wires 110 in the image, and when the distance between the two metal wires 110 that the first power module 120 outputs the first test electrical signal is 1um, the thermal imaging image obtained by the reflectivity thermal imager cannot identify that there are two adjacent metal wires 110 in the image, then it is judged that the spatial resolution of the reflectivity thermal imager is greater than 1um.

[0066] The reflectivity thermal imager testing method provided in the present disclosure can be used to test the spatial resolution of the reflectivity thermal imager, so that the spatial resolution of the reflectivity thermal imager can be further studied and improved based on the verification results.

[0067] Figure 6 This is a flow chart of a method for verifying temperature sensitivity according to one embodiment of the present disclosure. In one embodiment, after identifying the minimum distance between two metal wires based on the reflectivity thermal imager and determining the spatial resolution of the reflectivity thermal imager, the method further includes the following steps S210 to S250.

[0068] Step S210: controlling the reflectivity thermal imager to use a second incident light source to illuminate a second test sample area.

[0069] Similarly, the samples to be tested of different materials have different reflection effects on the same incident light source, so a suitable incident light source can be selected according to the material of the sample to be tested. A second incident light source is selected based on the material of the preset test interconnect structure, and the second test sample area 200 of the reflectivity thermal imager test module is placed in the test area of ​​the reflectivity thermal imager, and the second test sample area 200 is illuminated by the second incident light source.

[0070] Step S220: applying a second test electrical signal to the preset test interconnection structure in the second test sample area.

[0071] In some embodiments of the present disclosure, the second power module 220 may apply a second test electrical signal to the preset test interconnect structure 210 in the second test sample area, and the second test electrical signal flows through the preset test interconnect structure 210, and the preset test interconnect structure 210 will heat up. The temperature of the preset test interconnect structure 210 is measured at this time to determine the initial temperature of the preset test interconnect structure 210.

[0072] In some other embodiments, after the second test sample area 200 is placed in the test area of ​​the reflectivity thermal imager, the initial temperature of the temperature controller in the reflectivity thermal imager is set to T0, so that the initial temperature of the preset test interconnect structure 210 is T0.

[0073] Step S230: changing the value of the second test electrical signal to cause a temperature change in the preset test interconnection structure.

[0074] In some embodiments of the present disclosure, the temperature of the preset test interconnection structure 210 may be changed by changing the value of the second test electrical signal.

[0075] In some other embodiments, the second power module 220 may be instructed to output a second test electrical signal to the preset test interconnect structure 210 in the second test sample area 200 after the temperature of the temperature controller reaches stability, so that the preset test interconnect structure 210 completes the temperature rise and fall process.

[0076] Step S240: controlling the reflectivity thermal imager to determine the temperature change of the preset test interconnection structure.

[0077] After the second test sample area 200 of the reflectivity thermal imager test module is placed in the test area of ​​the reflectivity thermal imager, a lens with a suitable magnification is selected to synchronously monitor the second test sample area 200.

[0078] Step S250: determining the temperature sensitivity of the reflectivity thermal imager by identifying the minimum temperature variation amplitude of the preset test interconnection structure according to the reflectivity thermal imager.

[0079] The temperature of the preset test interconnect structure 210 is tested before and after the preset test interconnect structure 210 has a temperature change, and the actual temperature change value of the preset test interconnect structure 210 is determined. The reflectivity thermal imager is used to synchronously test the real-time temperature change of the second test sample area 200. When the reflectivity thermal imager can test the temperature change of the preset test interconnect structure 210, the degree of change of the value of the second test electrical signal is reduced, and the above steps are repeated to test the resolution of the reflectivity thermal imager for temperature changes when the actual temperature change value is smaller. The minimum temperature change amplitude of the preset test interconnect structure identified by the reflectivity thermal imager is determined as the temperature sensitivity of the reflectivity thermal imager.

[0080] For example, when the actual temperature change amplitude is ΔT1, the reflectivity thermal imager can identify that the temperature on the preset test interconnect structure 210 has changed, and when the actual temperature change amplitude is ΔT2 (ΔT1>ΔT2), the reflectivity thermal imager cannot identify that the temperature on the preset test interconnect structure 210 has changed, and it is judged that the temperature sensitivity of the reflectivity thermal imager can reach ΔT1. The reflectivity thermal imager test module provided by the present disclosure can be used to test the temperature sensitivity of the reflectivity thermal imager, so that the temperature sensitivity of the reflectivity thermal imager can be further studied and improved based on the verification results.

[0081] In one of the embodiments, before controlling the reflectivity thermal imager to use a second incident light source to illuminate a second test sample area, the method further includes adjusting a test bench temperature of the reflectivity thermal imager, calibrating a reflectivity calibration coefficient of the reflectivity thermal imager for a preset test interconnect structure, and the reflectivity thermal imager calibrates temperature changes according to the reflectivity calibration coefficient.

[0082] Since the reflectivity of the incident light of the same material is different at different temperatures, the reflectivity calibration coefficient Cth of the preset test interconnect structure 210 can be pre-calibrated, so that the recognition effect of the reflectivity thermal imager can be calibrated according to the reflectivity calibration coefficient Cth, thereby improving the recognition effect of the reflectivity thermal imager. When the test bench of the reflectivity thermal imager is at different temperatures, the reflectivity of the preset test interconnect structure 210 is tested by the reflectivity thermal imager. Furthermore, the reflectivity calibration coefficient Cth of the preset test interconnect structure 210 is calibrated according to the reflectivity of the preset test interconnect structure 210 by the reflectivity thermal imager at different temperatures. In some embodiments of the present disclosure, the reflectivity of the preset test interconnect structure 210 by the reflectivity thermal imager at no less than 2 points of temperature is obtained to calibrate the reflectivity calibration coefficient Cth of the preset test interconnect structure 210.

[0083] In one embodiment, after applying the second test electrical signal to the preset test interconnect structure in the second test sample area, the method further includes measuring a first voltage drop across the preset test interconnect structure and calculating a first resistance value of the preset test interconnect structure. After the second test sample area 200 is placed in the test area of ​​the reflectivity thermal imager, the initial temperature of the temperature controller in the reflectivity thermal imager is set to T0, so that the initial temperature of the preset test interconnect structure 210 is T0.

[0084] In some embodiments of the present disclosure, the second power module 220 includes a power pulse current source and a test pulse current source. The two pulse current sources are simultaneously connected to the pads of the preset test interconnect structure 210. The test pulse current source is used to output a smaller current to the preset test interconnect structure 210 to perform a pulse voltage test on the preset test interconnect structure 210, and the power pulse current source is used to output a larger current to the preset test interconnect structure 210 to load a power pulse thereon, thereby heating the preset test interconnect structure 210.

[0085] The test pulse current power supply, power pulse current source and reflectivity thermal imager are synchronized. The signal timing of the two pulse current sources is as follows: Figure 7 shown. Figure 7 This is a timing diagram of a temperature sensitivity test circuit for verifying one embodiment of the present disclosure. In this embodiment, at time t0, the test pulse current power supply outputs a pulse current Ia with a smaller value to the preset test interconnection structure 210 to perform a pulse voltage test on the preset test interconnection structure 210, and reads and records the first voltage drop across the preset test interconnection structure 210 at time t0 in the voltmeter. The first resistance value R0 of the preset test interconnection structure 210 at temperature T0 is calculated based on the pulse current Ia and the first voltage drop.

[0086] Figure 8 This is a flow chart of a method for calculating an actual temperature difference of a preset test interconnect structure according to one embodiment of the present disclosure. After changing the value of the second test electrical signal to cause a temperature change in the preset test interconnect structure, the method further includes the following steps S231 to S233.

[0087] Step S231: measuring a second voltage drop across the preset test interconnect structure, and calculating a second resistance value of the preset test interconnect structure.

[0088] After completing the test of the initial resistance value R0 of the preset test interconnect structure 210, the current source is switched to the power pulse current source, which outputs a larger current to the preset test interconnect structure 210 to load a power pulse thereon, so that the preset test interconnect structure 210 completes the heating process. At time t1, i.e., the moment when the power pulse current passed through the preset test interconnect structure 210 switches from a high level to a low level, the current source on the preset test interconnect structure 210 is switched to the test pulse current source. The test pulse current source is used again to output a pulse current Ia with a smaller value to the preset test interconnect structure 210, so as to perform a pulse voltage test on the preset test interconnect structure 210, and the second voltage drop across the preset test interconnect structure 210 at time t0 is read and recorded in the voltmeter. The second resistance value R1 of the preset test interconnect structure 210 after heating is calculated based on the pulse current Ia and the second voltage drop.

[0089] Step S233: determining the temperature difference between two resistance value measurement times according to the first resistance value and the second resistance value and based on the relationship between the resistivity of the metal material and the temperature.

[0090] Based on the relationship between the resistivity of the metal material and the temperature, the temperature T1 of the preset test interconnect structure 210 after heating can be obtained by combining the calculated first resistance value R0 and the second resistance value R1. The relationship between the resistance and temperature of the preset test interconnect structure 210 is as follows:

[0091] R1=R0(1+α×ΔT);

[0092]

[0093] Wherein, R1 is the second resistance value, R0 is the second resistance value, α is the resistance temperature coefficient, ΔT is the temperature difference between two resistance value measurements, T1 is the temperature value measured at time t1, T0 is the temperature value measured at time t0, and ΔR is the resistance difference between two resistance value measurements.

[0094] The temperature difference ΔT of the preset test interconnect structure 210 from time t0 to time t1 can be calculated based on the relationship between resistance and temperature. The temperature of the preset test interconnect structure 210 at time t0 and time t1 is tested synchronously using a reflectivity thermal imager. If the reflectivity thermal imager can test the change of temperature increase, it is considered that the temperature sensitivity of the reflectivity thermal imager can reach ΔT. The value of the power pulse current applied to the preset test interconnect structure 210 is reduced, and the above test steps are repeated to test the resolution capability of the reflectivity thermal imager when the temperature change is smaller, thereby determining the temperature sensitivity of the reflectivity thermal imager.

[0095] In one of the embodiments, when the preset test interconnect structure 210 is a spiral metal interconnect structure with a high thermal expansion coefficient, the resistance change through the spiral metal can also be calibrated according to the expansion of the volume of the spiral metal interconnect structure. The use of a metal material with a high thermal expansion coefficient as the preparation material of the spiral metal interconnect structure ensures that the resistance change can be accurately calibrated according to the expansion of the spiral metal interconnect structure, which is beneficial to improve the detection accuracy of the temperature sensitivity of the reflectivity thermal imager. In some other embodiments of the present disclosure, the resistance change of the preset test interconnect structure 210 measured in the "four-point method" test circuit can also be verified according to the expansion of the volume of the spiral metal interconnect structure.

[0096] Fig. 9 This is a flow chart of a method for verifying hotspot power detection capability according to one embodiment of the present disclosure. In one embodiment, after identifying the minimum distance between two metal wires based on the reflectivity thermal imager and determining the spatial resolution of the reflectivity thermal imager, the method further includes the following steps S310 to S350.

[0097] Step S310: controlling the reflectivity thermal imager to use a third incident light source to illuminate a third test sample area.

[0098] Similarly, the samples to be tested of different materials have different reflection effects on the same incident light source, so a suitable incident light source can be selected according to the material of the sample to be tested. A suitable third incident light source is selected based on the material of the test resistor 310, the third test sample area 300 of the reflectivity thermal imager test module is placed in the test area of ​​the reflectivity thermal imager, and the third test sample area 300 is irradiated with the third incident light source.

[0099] Step S320: applying a third test electrical signal to the test resistor in the third test sample area.

[0100] The test resistor 310 is connected to the third power module 320 through the metal pads at both ends. In some embodiments of the present disclosure, the third power module 320 can be a pulse current source / voltage source. The pulse current output by the third power module 320 is sent to the test resistor 310, causing it to heat up and form a hot spot.

[0101] Step S330: controlling the reflectivity thermal imager to focus on the test resistor.

[0102] After the third test sample area 300 of the reflectivity thermal imager test module is placed in the test area of ​​the reflectivity thermal imager, the third power module 320 is synchronously set with the reflectivity thermal imager, and a lens with a suitable magnification is selected to focus and image the third test sample area 300. The reflectivity thermal imager collects the temperature on the test resistor 310 at the end of the high-level signal of the pulse power supply to obtain the temperature data when the test resistor 310 is at the highest temperature point.

[0103] Step S340: changing the value of the third test electrical signal to change the heating power of the test resistor.

[0104] The heating power of the test resistor 310 can be calculated according to the following formula:

[0105] P=I 2 ×R;

[0106] Wherein, P is the heating power of the test resistor 310, I is the current passing through the test resistor 310 when the pulse power supply is at a high level, and R is the resistance value of the test resistor 310. The resistance value of the test resistor 310 can be obtained by measuring using a four-wire method.

[0107] It can be seen from the calculation formula of the heating power of the test resistor 310 that the heating power of the test resistor 310 can be controlled by changing the current applied to both ends of the test resistor 310 .

[0108] Step S350: Determine the hot spot power detection capability of the reflectivity thermal imager according to the minimum heating power at which the reflectivity thermal imager identifies the test resistor as a hot spot.

[0109] By continuously reducing the value of the third test electrical signal, the heating power of the test resistor 310 is gradually reduced. At the same time, the reflectivity thermal imager synchronously collects the temperature image of the test resistor 310. The minimum heating power at which the test resistor 310 can be clearly identified as a hot spot based on the temperature image is used to determine the minimum hot spot detection power of the reflectivity thermal imager.

[0110] For example, when the heating power of the test resistor 310 is P1, the hot spot pattern of the test resistor 310 in the figure can be identified based on the temperature image obtained by the reflectivity thermal imager, and when the heating power of the test resistor 310 is P2 (P1>P2), the hot spot pattern of the test resistor 310 in the figure cannot be identified based on the temperature image obtained by the reflectivity thermal imager, then it is judged that the minimum hot spot detection power of the reflectivity thermal imager is P1.

[0111] The reflectivity thermal imager test module provided by the present disclosure can be used to test the hotspot power detection capability of the reflectivity thermal imager, so that the hotspot power detection capability of the reflectivity thermal imager can be further studied and improved based on the verification results.

[0112] It should be understood that although Figure 5-Figure 6 , Figure 8-Figure 9 The steps in the flowchart are shown in sequence as indicated by the arrows, but these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise specified in this document, there is no strict order restriction for the execution of these steps, and these steps can be executed in other orders. Moreover, Figure 5-Figure 6 , Figure 8-Figure 9 At least part of the steps may include multiple steps or multiple stages. These steps or stages are not necessarily performed at the same time, but can be performed at different times. The execution order of these steps or stages is not necessarily sequential, but can be performed in turn or alternately with other steps or at least part of the steps or stages in other steps.

[0113] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", "ideal embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example.

[0114] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0115] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims.

Claims

1. A reflectivity thermal imager test module, characterized in that: A first test sample area is included, wherein the first test sample area includes: A plurality of metal wires arranged at different intervals, each of the metal wires having pads at both ends and each of the metal wires having the same size; a first power module connected to the pads of any two adjacent metal wires, and configured to provide a first test electrical signal to any two adjacent metal wires; The reflectivity thermal imager test module further includes a second test sample area, and the second test sample area includes: A preset test interconnection structure, wherein pads are provided at both ends of the preset test interconnection structure; The second power module is connected to the pad of the preset test interconnect structure and is used to provide a second test electrical signal to the preset test interconnect structure.

2. The reflectivity thermal imager test module according to claim 1, characterized in that: The preset test interconnection structure includes a spiral metal interconnection structure.

3. The reflectivity thermal imager test module according to claim 2, characterized in that: The spiral metal interconnection structure adopts a metal material with a preset thermal expansion coefficient.

4. The reflectivity thermal imager test module according to claim 1, characterized in that: The reflectivity thermal imager test module further includes a third test sample area, and the third test sample area includes: A test resistor, wherein two ends of the test resistor are respectively connected to two pads at a preset distance; The third power module is connected to the pads at both ends of the test resistor and is used to provide a third test electrical signal to the test resistor.

5. A reflectivity thermal imager testing method, applied to the reflectivity thermal imager testing module according to any one of claims 1 to 4, characterized in that: The method comprises: Controlling the reflectivity thermal imager to illuminate the first test sample area using a first incident light source; Applying a first test electrical signal to two adjacent metal strips spaced at different distances in the first test sample area to heat the two metal strips; Controlling the reflectivity thermal imager to focus and image the metal strips in the first test sample area; The spatial resolution of the reflectivity thermal imager is determined based on the minimum distance between two metal lines identified by the reflectivity thermal imager.

6. The reflectivity thermal imager testing method according to claim 5, characterized in that: After the minimum distance between two metal lines is identified by the reflectivity thermal imager and the spatial resolution of the reflectivity thermal imager is determined, the method further includes: Controlling the reflectivity thermal imager to illuminate a second test sample area using a second incident light source; applying a second test electrical signal to the preset test interconnect structure in the second test sample area; changing the value of the second test electrical signal to cause a temperature change in the preset test interconnect structure; Controlling the reflectivity thermal imager to determine the temperature change of the preset test interconnect structure; The temperature sensitivity of the reflectivity thermal imager is determined based on the minimum temperature variation amplitude of the preset test interconnect structure identified by the reflectivity thermal imager.

7. The reflectivity thermal imager testing method according to claim 6, characterized in that: Before controlling the reflectivity thermal imager to use a second incident light source to illuminate the second test sample area, the method further includes: The test bench temperature of the reflectivity thermal imager is adjusted to calibrate the reflectivity calibration coefficient of the reflectivity thermal imager for the preset test interconnect structure; the reflectivity thermal imager calibrates the recognition result of the temperature change according to the reflectivity calibration coefficient.

8. The reflectivity thermal imager testing method according to claim 6, characterized in that: After applying a second test electrical signal to the preset test interconnect structure in the second test sample area, the method further includes: Measuring a first voltage drop across the preset test interconnect structure, and calculating a first resistance value of the preset test interconnect structure; After changing the value of the second test electrical signal to cause a temperature change in the preset test interconnect structure, the method further includes: Measuring a second voltage drop across the preset test interconnect structure, and calculating a second resistance value of the preset test interconnect structure; According to the first resistance value and the second resistance value, the temperature difference between the two resistance value measurement times is determined based on the relationship between the resistivity of the metal material and the temperature.

9. The reflectivity thermal imager testing method according to claim 5, characterized in that: After the minimum distance between two metal lines is identified by the reflectivity thermal imager and the spatial resolution of the reflectivity thermal imager is determined, the method further includes: Controlling the reflectivity thermal imager to illuminate a third test sample area using a third incident light source; applying a third test electrical signal to the test resistor in the third test sample area; Controlling the reflectivity thermal imager to focus and image the test resistor; Changing the value of the third test electrical signal to change the heating power of the test resistor; The hot spot power detection capability of the reflectivity thermal imager is determined based on the minimum heating power at which the reflectivity thermal imager identifies the test resistor as a hot spot.

Images