Method and device for measuring power map temperature distribution of chip

Abstract

The embodiment of the invention provides a chip power map temperature distribution measuring method and device, and the method comprises the steps: determining the corresponding relation between the blackbody radiation quantity and the temperature; acquiring the first radiation quantity of each pixel point of the chip at a plurality of different second temperatures; for each pixel point in the pixel points, determining the first emissivity of the pixel point; determining the actual emissivity of each pixel point according to the plurality of first emissivity of each pixel point; acquiring a second radiation quantity of each pixel point of the chip in a working state; and determining the black body radiation quantity of each pixel point in the working state according to the second radiation quantity and the actual emissivity of each pixel point, and determining the corresponding temperature, thereby obtaining chip power map temperature distribution. The problem that a large error exists between the measured temperature and the actual temperature of the chip due to the fact that the emissivity of each pixel point of the chip is regarded as the same emissivity in the related technology can be solved.

Description

Technical Field

[0001] The embodiments of the present invention relate to the field of chips, and in particular to a method and device for measuring chip powermap temperature distribution. Background Art

[0002] Chip process scaling towards ever-smaller dimensions has led to a continuous increase in chip power consumption and heat flux. Coupled with the rapid development of 2.5D and 3D heterogeneous chips, serious hotspot issues have emerged within chips. Failure to identify hotspots can degrade chip reliability, performance, and power consumption. Furthermore, chip area is limited, limiting the number of T-sensors or digital temperature sensors (DTSs) that can be placed. To ensure chip functionality and layout, T-sensors cannot be placed at the center of a hotspot. This results in understated chip junction temperatures reported by T-sensors in actual measurements, underestimating the chip's thermal risk. Currently, there is no method for obtaining the temperature distribution of a chip's power map. Thermal simulation is the only way to obtain the temperature distribution of a chip's power map. However, due to errors in power input, packaging structure, and variations in heat dissipation boundaries, the simulated temperature distribution can differ significantly from the actual temperature distribution. Furthermore, since the power density of internal chip modules is calculated on a per-module basis, the actual heat flux density of a hotspot can be significantly higher than that of a per-module basis, resulting in simulated hotspot temperatures that are lower than the actual temperature.

[0003] Currently, one method for infrared measurement of chip temperature distribution involves spraying or applying a coating material of known emissivity to the back of the chip. The chip's emissivity is then adjusted to determine the chip's temperature distribution. However, the coating material alters the chip's internal temperature distribution and blocks heat from the chip, resulting in the temperature distribution captured by the infrared camera not being the true temperature distribution. Because the internal layout and wiring of chips vary, the emissivity of each location on the layout and wiring layer varies. Assigning a single emissivity value to the chip results in significant temperature errors during infrared testing.

[0004] Regarding the problem in related technologies where the emissivity of each pixel of a chip is considered to be the same, resulting in a large error between the measured temperature and the actual temperature of the chip, no suitable solution has yet been proposed. Summary of the Invention

[0005] The embodiments of the present invention provide a method and device for measuring the powermap temperature distribution of a chip, so as to at least solve the problem in the related art that the emissivity of each pixel point of the chip is regarded as the same emissivity, resulting in a large error between the measured temperature and the actual temperature of the chip.

[0006] According to one embodiment of the present invention, a method for measuring chip powermap temperature distribution is provided, the method comprising:

[0007] The infrared camera is used to collect the radiation amount of the black body at a plurality of different first temperatures to determine the corresponding relationship between the black body radiation amount and the temperature;

[0008] Collecting the first radiation amount of each pixel of the chip at a plurality of different second temperatures by the infrared camera;

[0009] For each of the pixels, determining a first emissivity of the pixel at the second temperature based on an amount of blackbody radiation corresponding to each of the multiple different second temperatures and the first radiation amount of the pixel at the second temperature, thereby obtaining a plurality of first emissivities of each pixel corresponding one-to-one to the multiple different second temperatures;

[0010] Determining an actual emissivity of each pixel point according to the multiple first emissivities of each pixel point;

[0011] collecting, by the infrared camera, a second radiation amount of each pixel of the chip in a working state;

[0012] The blackbody radiation of each pixel in the working state is determined according to the second radiation amount and the actual emissivity of each pixel, and the temperature corresponding to the blackbody radiation of each pixel in the working state is determined according to the corresponding relationship between the blackbody radiation and the temperature, as the temperature of each pixel in the working state, thereby obtaining the chip powermap temperature distribution.

[0013] According to another embodiment of the present invention, there is provided a device for measuring the temperature distribution of a chip power map powermap, the device comprising an infrared camera and a data processing program;

[0014] The infrared camera is used to collect the radiation amount of the black body at multiple different first temperatures;

[0015] The data processing program is used to determine the corresponding relationship between blackbody radiation and temperature;

[0016] The infrared camera is further used to collect the first radiation amount of each pixel point of the chip at a plurality of different second temperatures;

[0017] The data processing program is further configured to determine, for each of the pixels, a first emissivity of the pixel at the second temperature based on the amount of blackbody radiation corresponding to each of the multiple different second temperatures and the first radiation of the pixel at the second temperature, thereby obtaining a plurality of first emissivities of each pixel corresponding one-to-one to the multiple different second temperatures; and determine an actual emissivity of each pixel based on the multiple first emissivities of each pixel.

[0018] The infrared camera is further used to collect a second radiation amount of each pixel of the chip when the chip is in a working state;

[0019] The data processing program is also used to determine the blackbody radiation of each pixel in the working state based on the second radiation of each pixel and the actual emissivity, and determine the temperature corresponding to the blackbody radiation of each pixel in the working state based on the correspondence between the blackbody radiation and the temperature, as the temperature of each pixel in the working state, thereby obtaining the chip powermap temperature distribution.

[0020] According to another embodiment of the present invention, the device further comprises a semiconductor cooler (TEC) located below the chip, for controlling the temperature of the chip to reach the plurality of different second temperatures and dissipating heat from the chip in a working state.

[0021] According to another embodiment of the present invention, the device further includes a heat stage located below the chip and a liquid cooling device located above the chip, wherein the heat stage is used to control the temperature of the chip to reach the multiple different second temperatures, and the liquid cooling device is used to dissipate heat from the chip in a working state.

[0022] The present invention solves the problem in related technologies of regarding the emissivity of each pixel point of the chip as the same emissivity, which leads to a large error between the measured temperature and the actual temperature of the chip, and obtains a more accurate distribution cloud map of the chip temperature. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 is a flow chart of a method for measuring chip powermap temperature distribution according to an embodiment of the present invention;

[0024] Figure 2 is a specific flow chart of temperature-radiation calibration of an infrared camera according to an embodiment of the present invention;

[0025] Figure 3 is a flow chart of determining the actual emissivity of each pixel of a chip according to an embodiment of the present invention;

[0026] Figure 4 Schematic diagram of a device for measuring chip powermap temperature distribution according to an embodiment of the present invention Figure 1 ;

[0027] Figure 5 Schematic diagram of a device for measuring chip powermap temperature distribution according to an embodiment of the present invention Figure 2 . DETAILED DESCRIPTION

[0028] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings and in combination with embodiments.

[0029] It should be noted that the terms "target", "second" and the like in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence.

[0030] In this embodiment, a method for measuring chip powermap temperature distribution is provided. Figure 1 FIG. 1 is a flow chart of a method for measuring chip powermap temperature distribution according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps:

[0031] Step S102, collecting the radiation amount of the black body at a plurality of different first temperatures by an infrared camera to determine the corresponding relationship between the black body radiation amount and the temperature;

[0032] In this embodiment, the measuring method may be performed by a computer, a data processing program, or manual labor.

[0033] In one embodiment, the infrared camera is a medium-wave infrared camera. Infrared measurement technologies include long-wave infrared, medium-wave infrared, and short-wave infrared. Chips (also known as silicon wafers) have a high transmittance in the medium-wave band, generally greater than 80%. To reduce errors in chip temperature measurement, a medium-wave infrared camera is preferred in this embodiment.

[0034] During the measurement process, the infrared camera is placed at a set distance from the black body, where the set distance is the focal length of the infrared camera. The temperature-radiation calibration of the infrared camera is completed through the above step S102.

[0035] Figure 2 FIG. 1 is a specific flow chart of temperature-radiation calibration of an infrared camera according to an embodiment of the present invention. Figure 2 As shown, the above step S102 specifically includes:

[0036] Step S202, using an infrared camera to collect the radiation amount of the black body at the initial temperature;

[0037] Step S204, using an infrared camera to collect the radiation amount of the black body at a first temperature, wherein the first temperature is the current temperature plus a preset increment, and step S204 is repeated until sufficient measurement data is obtained;

[0038] The initial temperature and the first temperature are within the range of the ambient temperature and the chip operating temperature.

[0039] Step S206 : establishing a corresponding relationship between the blackbody radiation and temperature based on the radiation amounts of the blackbody collected by the infrared camera at a plurality of different first temperatures.

[0040] Through the above steps S202 to S204, the temperature-radiation calibration of the infrared camera is completed. In the subsequent process, the corresponding temperature can be obtained based on the blackbody radiation and the above corresponding relationship.

[0041] Step S104, collecting the first radiation amount of each pixel of the chip at a plurality of different second temperatures by the infrared camera;

[0042] The pixel points are the pixel points imaged by the chip in the infrared camera.

[0043] In one embodiment, the chip is a chip with the backside opaque material removed, and the material includes at least one of the following: thermal interface material (TIM), cover material (lid), and plastic encapsulation material. The embodiment of the present invention is applicable to chips that use flip-chip (FC) packaging and can support the removal of backside packaging materials, wherein FC packaging includes flip-chip ball grid array (FCBGA) packaging and flip-chip scale package (FCCSP). In addition, the wafer of the chip in the present invention preferably uses a silicon substrate, but can also be a silicon carbide (SiC) wafer used for insulated gate bipolar transistors (IGBTs).

[0044] Before the above step S104, the method also includes removing the heat dissipation device of the chip, wherein the heat dissipation device of the chip may include a LED, a TIM, a radiator, etc., wherein the LED is a material that is transmissive to medium-wave infrared, such as sapphire, silicon carbide SiC, diamond, etc., and is used to be attached to the back of the chip for heat dissipation; a radiator, a semiconductor cooler (TEC), etc. may also be used under the PCB board under the chip for heat dissipation, and the introduction of other materials in the test environment is minimized to avoid interference with radiation.

[0045] In this embodiment, the plurality of second temperatures may include two or more temperatures. For example, the two second temperatures may include a fourth temperature and a fifth temperature.

[0046] In this embodiment, in order to construct a test environment for the chip at multiple different second temperatures, a constant temperature heating method can be adopted, for example, a temperature box or a method of heating the printed circuit board (PCB) under the chip can be adopted.

[0047] In one embodiment, the plurality of different second temperatures are controlled by a semiconductor cooler (TEC) located under the chip.

[0048] In another embodiment, the plurality of different second temperatures are controlled by a heat stage located below the chip.

[0049] During the above measurement process, the position of the chip relative to the infrared camera remains unchanged.

[0050] Step S106: For each of the pixels, determine the first emissivity of the pixel at the second temperature based on the blackbody radiation corresponding to each of the multiple different second temperatures and the first radiation of the pixel at the second temperature, thereby obtaining a plurality of first emissivities of each pixel corresponding one-to-one to the multiple different second temperatures; and determine the actual emissivity of each pixel based on the multiple first emissivities of each pixel.

[0051] The blackbody radiation amount corresponding to each second temperature among the multiple different second temperatures is obtained by finding the blackbody radiation amount corresponding to the second temperature from the corresponding relationship between the blackbody radiation amount and temperature.

[0052] In practice, the emissivity of each pixel of the chip is not consistent. Therefore, in order to obtain accurate measurement results, in this embodiment, the emissivity of each pixel of the chip is measured multiple times at different temperatures for calibration.

[0053] In this embodiment, the value of the first emissivity combines the emissivity of the chip itself and the transmittance of various materials on the path from the heat source to the infrared camera.

[0054] In one embodiment, the first emissivity of the pixel point at the second temperature is determined based on the blackbody radiation corresponding to each second temperature among the multiple different second temperatures and the first radiation of the pixel point at the second temperature, including: dividing the blackbody radiation corresponding to each second temperature among the multiple different second temperatures by the first radiation of the pixel point at the second temperature to obtain the first emissivity of the pixel point at the second temperature.

[0055] In one embodiment, the actual emissivity of each pixel point is determined based on the multiple first emissivities of each pixel point, including: for each pixel point, when the multiple first emissivities of the pixel point are consistent, determining the multiple first emissivities as the actual emissivity of the pixel point; for each pixel point, when the multiple first emissivities of the pixel point are inconsistent, changing the second temperature until the multiple first emissivities of the pixel point are consistent.

[0056] In one embodiment, for each pixel point, when the multiple first emissivities of the pixel point are inconsistent, the second temperature is changed until the multiple first emissivities are consistent, including: for each pixel point, when the multiple first emissivities of the pixel point are inconsistent, the second temperature is changed and the heating time is increased until the multiple first emissivities are consistent.

[0057] In a specific embodiment, the multiple different second temperatures include a fourth temperature and a fifth temperature. For each pixel, the first emissivity of the pixel is determined to be the fourth emissivity at the fourth temperature, and the first emissivity of the pixel is determined to be the fifth emissivity at the fifth temperature. When the fourth emissivity and the fifth emissivity are consistent, the fourth emissivity and the fifth emissivity are determined to be the actual emissivity of the pixel. If the fourth emissivity and the fifth emissivity are inconsistent, the chip is heated to a sixth temperature, the chip heating time is increased, the sixth emissivity of the pixel is determined, and it is determined whether the fourth emissivity or the fifth emissivity is consistent with the sixth emissivity. If they are consistent, the sixth emissivity is determined to be the actual emissivity of the pixel.

[0058] When the chip is heated to the fourth temperature and the fifth temperature, the heating time of the chip may be too short, resulting in the chip temperature not reaching a stable state, which may cause inconsistency between the fourth emissivity and the fifth emissivity. Therefore, when the chip is heated to the sixth temperature, the heating time is increased so that the chip temperature reaches a stable state, thereby improving the consistency of multiple emissivities.

[0059] Figure 3 This is a flow chart of determining the actual emissivity of each pixel of a chip according to an embodiment of the present invention. The flow chart may specifically include:

[0060] Step S302, collecting, by the infrared camera, a first radiation amount of each pixel of the chip at a fourth temperature; for each of the pixels, determining a fourth emissivity of the pixel at the fourth temperature based on a blackbody radiation amount corresponding to the fourth temperature and the first radiation amount of the pixel at the fourth temperature;

[0061] Step S304, collecting, by the infrared camera, a first radiation amount of each pixel of the chip at a fifth temperature; for each of the pixels, determining a fifth emissivity of the pixel at the fifth temperature based on the blackbody radiation amount corresponding to the fifth temperature and the first radiation amount of the pixel at the fifth temperature;

[0062] In step S306, if the fourth emissivity and the fifth emissivity of the pixel are consistent, the fourth emissivity is determined to be the actual emissivity of the pixel. If the fourth emissivity and the fifth emissivity of the pixel are inconsistent, the chip is heated to the sixth temperature and the process proceeds to step S304 until the multiple emissivities are consistent. For example, the fourth emissivity or the fifth emissivity is consistent with the sixth emissivity.

[0063] In the above steps S302-S306, by measuring the emissivity of each pixel point of the chip multiple times, an accurate emissivity cloud map of each pixel point of the chip can be obtained.

[0064] Step S108, collecting a second radiation amount of each pixel of the chip in a working state by the infrared camera;

[0065] In this embodiment, while the infrared camera is collecting the first and second radiation amounts of each pixel, the position of each pixel remains unchanged. That is, during the test, the test bench and the chip are kept stationary, including the absolute positions of the infrared camera and the chip.

[0066] In one embodiment, the chip being in an operating state means that the chip is powered on and a heat sink is installed for heat dissipation. The heat sink is in an operating state. If the heat sink is a liquid cooling device located above the chip, the fluid circulation system of the liquid cooling device is activated to dissipate heat through the liquid cooling device. If the heat sink is a TEC, the heat is dissipated through the TEC.

[0067] Step S110, determining the blackbody radiation of each pixel in the working state according to the second radiation amount and the actual emissivity of each pixel, and determining the temperature corresponding to the blackbody radiation of each pixel in the working state according to the correspondence between the blackbody radiation and the temperature as the temperature of each pixel in the working state, thereby obtaining the chip powermap temperature distribution.

[0068] In this embodiment, the blackbody radiation of each pixel point in the working state is determined based on the second radiation amount and the actual emissivity of each pixel point, including: dividing the second radiation amount of each pixel point by the actual emissivity of the pixel point to obtain the blackbody radiation of the pixel point in the working state.

[0069] After the above step S110, the method further includes: generating an infrared image for chip thermal analysis based on the pixel temperature value and the pixel size with the aid of data processing software.

[0070] Through the above steps S102 to S110, based on infrared thermal imaging technology, an infrared camera is used to directly photograph the back side of the exposed chip, and the infrared emissivity of the chip is obtained by constant temperature heating and pixel-by-pixel calibration. Then, a specific heat dissipation solution is used at the same field of view position, and the chip is photographed when it is powered on and working. The calibrated infrared emissivity is brought in according to the amount of radiation photographed, so that the true temperature distribution map of the chip can be obtained. This can solve the problem in related technologies that the emissivity of each pixel of the chip is regarded as the same emissivity, resulting in a large error between the measured temperature and the actual temperature of the chip, and thus the temperature distribution of the chip when it is powered on and working can be accurately measured. In addition, the method for measuring the chip powermap temperature distribution in this embodiment also has the following beneficial effects: 1. By adopting pixel-by-pixel calibration, the measurement accuracy is higher, and the temperature measurement of the chip powermap can be directly completed, which can be used to replace the method of measuring the shell temperature and calculating the power consumption thermal resistance by thermocouples in the prior art, as well as the method of measuring the chip temperature by T-sensors; 2. When the number of T-sensors in the chip is insufficient, the actual temperature distribution of the chip can be obtained in real time, providing a basis for the layout optimization of the chip; 3. The junction temperature of the chip can be accurately identified to avoid the hidden danger of overheating.

[0071] The embodiment of the present invention further provides a device for measuring the temperature distribution of a chip power map powermap, the device comprising an infrared camera and a data processing program;

[0072] The infrared camera is used to collect the radiation amount of the black body at multiple different first temperatures;

[0073] The data processing program is used to determine the corresponding relationship between blackbody radiation and temperature;

[0074] The infrared camera is further used to collect the first radiation amount of each pixel point of the chip at a plurality of different second temperatures;

[0075] The data processing program is further configured to determine, for each of the pixels, a first emissivity of the pixel at the second temperature based on the amount of blackbody radiation corresponding to each of the multiple different second temperatures and the first radiation of the pixel at the second temperature, thereby obtaining a plurality of first emissivities of each pixel corresponding one-to-one to the multiple different second temperatures; and determine an actual emissivity of each pixel based on the multiple first emissivities of each pixel.

[0076] The infrared camera is further used to collect a second radiation amount of each pixel of the chip when the chip is in a working state;

[0077] The data processing program is also used to determine the blackbody radiation of each pixel in the working state based on the second radiation of each pixel and the actual emissivity, and determine the temperature corresponding to the blackbody radiation of each pixel in the working state based on the correspondence between the blackbody radiation and the temperature, as the temperature of each pixel in the working state, thereby obtaining the chip powermap temperature distribution.

[0078] In an embodiment of the present invention, the device further includes a printed circuit board PCB located below the chip, for supplying power to the chip in a working state.

[0079] In one embodiment, the device further comprises a semiconductor cooler (TEC) located below the chip, for controlling the temperature of the chip to reach the plurality of different second temperatures and dissipating heat from the chip in a working state.

[0080] In the embodiment of the present invention, TEC is used to heat and dissipate heat for the chip, which simplifies the test structure, avoids pixel offset caused by switching the test environment, and does not interfere with the infrared radiation amount in the test to cause measurement errors.

[0081] Figure 4 Schematic diagram of a device for measuring chip powermap temperature distribution according to an embodiment of the present invention Figure 1 ,like Figure 4 As shown, the measuring device includes: an infrared camera lens 101, a PCB 201, and a TEC 301. In addition, for ease of understanding, a chip 202 and an infrared radiation amount 203 are also shown.

[0082] Among them, the infrared camera lens 101 is used to receive the infrared radiation of the chip 202 to be tested; the PCB 201 is located below the chip and realizes the power supply and signal transmission of the chip 202; the chip 202 is to be infrared tested to obtain the temperature cloud map of each pixel point in its working state; the infrared radiation 203 increases after the temperature of the chip 202 rises; the TEC 301 is used to heat and dissipate heat of the chip 202 at a constant temperature.

[0083] It should be noted that Figure 4 Only the overall layout of the measuring device is illustrated. To keep the picture concise, local details are not shown. It is not the specific structure in the actual test. Other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative work shall fall within the scope of protection of the present invention.

[0084] Based on the above-mentioned measuring device, an embodiment of the present invention further provides a measuring method running on the measuring device. Before the measurement process, the temperature and infrared radiation amount calibration of the infrared camera is completed by default. The measurement process is specifically as follows:

[0085] (1) A TEC module is installed on the back of the PCB board. The TEC can achieve chip heating and heat dissipation;

[0086] (2) First, use TEC to heat the PCB board so that the chip temperature reaches a certain temperature. The chip temperature can be measured by thermocouple or other temperature measurement methods;

[0087] (3) The infrared radiation amount of each pixel point of the chip in step (2) measured by the camera is divided by the blackbody calibration radiation amount corresponding to the problem in the above step (2) measured by the camera to obtain the infrared emissivity cloud map of the chip;

[0088] (4) Keep the test bench and chip in absolutely fixed position, reverse the TEC power supply, and use the cooling mode to dissipate heat from the chip. When the chip is powered on and working normally, take a picture of the chip's infrared cloud image with the camera. Substitute it into the infrared emissivity cloud image calibration in step (3) to obtain the chip's infrared cloud image.

[0089] In another embodiment, the device further includes a heat stage located below the chip and a liquid cooling device located above the chip, wherein the heat stage is used to control the temperature of the chip to reach the multiple different second temperatures, and the liquid cooling device is used to dissipate heat from the chip in a working state.

[0090] In one embodiment, the liquid cooling device includes at least one of the following: cooling liquid, an oil cooling shell, and a transmission window, wherein the transmission window is located above the chip and is in rigid contact with the chip, and the oil cooling shell is located around the chip to limit the flow of the cooling liquid around the chip and seal it.

[0091] In this embodiment of the present invention, a rigid infrared transmission window in contact with the chip can avoid measurement errors caused by liquid during testing. Using a heat sink consisting of liquid cooling, a transmission window, and an oil-cooled shell to dissipate heat from the chip prevents pixel shifts caused by switching between test environments, preventing interference with infrared radiation during testing and causing measurement errors.

[0092] Figure 5 Schematic diagram of a device for measuring chip powermap temperature distribution according to an embodiment of the present invention Figure 2 ,like Figure 5 As shown, the measuring device includes: an infrared camera lens 101, a PCB 201, a heating block 401, an oil-cooling shell 402, an oil-cooling liquid 403, and a transmission 404. In addition, for ease of understanding, a chip 202 and an infrared radiation amount 203 are also shown.

[0093] Among them, the infrared camera lens 101 is used to receive the infrared radiation of the chip 202 to be tested; the PCB 201 is located below the chip 202 to realize power supply and signal transmission for the chip 202; the chip 202 is to be infrared tested to obtain a temperature cloud map of each pixel point in its working state; the infrared radiation 203 increases after the temperature of the chip 202 rises; the heating block 401 is used to heat the chip 202 at a constant temperature; the oil-cooling shell 402 is used to limit the flow of oil-cooling liquid 403 around the chip 202; the oil-cooling liquid 403 is used to undergo convective heat exchange with the transmission window 404 for heat dissipation; and the transmission window 404 is used to rigidly contact the chip 202 for heat dissipation.

[0094] It should be noted that, in addition to TEC, liquid cooling liquid, and transmission window heat dissipation, other forms of heat dissipation devices may also be used in the embodiments of the present invention, such as air cooling, low-temperature fluorinated liquid heat dissipation, etc.

[0095] The embodiment of the present invention further provides a measurement method running on the above measurement device. Before the measurement process, the temperature and infrared radiation calibration of the infrared camera are completed by default. The measurement process is as follows:

[0096] (1) Fix the heating block on the back of the PCB board, and the heating block is used for constant temperature testing of the chip;

[0097] (2) First, use a heating block to heat the PCB board so that the chip temperature reaches a certain temperature. The chip temperature can be measured by a thermocouple or other temperature measurement methods;

[0098] (3) The infrared radiation amount of each pixel point of the chip in step (2) measured by the camera is divided by the blackbody calibration radiation amount corresponding to the problem in the above step (2) measured by the camera to obtain the infrared emissivity cloud map of the chip;

[0099] (4) Keep the test bench and chip in absolutely fixed position, start the fluid circulation system to dissipate heat for the chip. When the chip is powered on and working normally, take a picture of the chip's infrared cloud image with the camera, and substitute it into the infrared emissivity cloud image calibration in step (3) to obtain the chip's infrared cloud image.

[0100] The main technologies in the embodiments of the present invention are summarized as follows: 1. The method for measuring the power map temperature distribution of a chip in the embodiment of the present invention can accurately measure the power map temperature distribution of the chip through pixel-by-pixel calibration. The test method is simple and has few measurement steps. 2. The embodiment of the present invention proposes a method and measurement device for measuring the power map temperature distribution of a chip, constructing a complete chip infrared thermal testing process, covering the test method, test device, heating and cooling devices for the test chip, and data processing methods. 3. Two heat dissipation devices are proposed. One is to use TEC to heat and dissipate heat for the chip, which simplifies the test structure and can avoid pixel offset caused by switching test environments, without interfering with the infrared radiation amount during the test and causing measurement errors. The other is to use a heat dissipation device with liquid cooling, transmission window, and oil cooling shell to dissipate heat for the chip. The infrared transmission window is in rigid contact with the chip under test, which can avoid pixel offset caused by switching test environments, without interfering with the infrared radiation amount during the test and causing measurement errors. 4. The chip temperature measurement method in the embodiment of the present invention can accurately identify and locate the hot spot distribution and temperature value of the chip, quantify the hot spot size, and identify heat dissipation risks, which is superior to traditional thermal testing methods.

[0101] The measurement method and device in the embodiments of the present invention can intuitively obtain the temperature distribution on the chip surface, making up for the shortcoming of insufficient number of T-sensors arranged in the chip. They can accurately identify chip hotspots and can be used for chip thermal measurement analysis, comparing with PowerMap simulation results, evaluating the accuracy of power consumption input, and providing basic data for chip mass production.

[0102] The foregoing description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the principles of the present invention are intended to be within the scope of protection of the present invention.

Claims

1. A method for measuring the temperature distribution of a chip power map powermap, characterized in that: The method comprises: The infrared camera is used to collect the radiation amount of the black body at a plurality of different first temperatures to determine the corresponding relationship between the black body radiation amount and the temperature; Collecting the first radiation amount of each pixel of the chip at a plurality of different second temperatures by the infrared camera; For each of the pixels, determining a first emissivity of the pixel at the second temperature based on an amount of blackbody radiation corresponding to each of the multiple different second temperatures and the first radiation amount of the pixel at the second temperature, thereby obtaining a plurality of first emissivities of each pixel corresponding one-to-one to the multiple different second temperatures; Determining an actual emissivity of each pixel point according to the multiple first emissivities of each pixel point; collecting, by the infrared camera, a second radiation amount of each pixel of the chip in a working state; The blackbody radiation of each pixel in the working state is determined according to the second radiation amount and the actual emissivity of each pixel, and the temperature corresponding to the blackbody radiation of each pixel in the working state is determined according to the relationship between each temperature and the blackbody radiation, as the temperature of each pixel in the working state, thereby obtaining the chip powermap temperature distribution.

2. The measuring method according to claim 1, wherein Determining the actual emissivity of each pixel point according to the multiple first emissivities of each pixel point includes: For each pixel, when the multiple first emissivities of the pixel are consistent, determining the multiple first emissivities as the actual emissivity of the pixel; For each pixel point, when the multiple first emissivities of the pixel point are inconsistent, the second temperature is changed until the multiple first emissivities of the pixel point are consistent.

3. The measuring method according to claim 2, characterized in that For each pixel point, when the multiple first emissivities of the pixel point are inconsistent, changing the second temperature until the multiple first emissivities are consistent, comprising: For each pixel point, when the multiple first emissivities of the pixel point are inconsistent, the second temperature is changed and the heating time is increased until the multiple first emissivities are consistent.

4. The measuring method according to claim 1, wherein Determining a first emissivity of the pixel at the second temperature according to a blackbody radiation amount corresponding to each second temperature among the multiple different second temperatures and a first radiation amount of the pixel at the second temperature includes: The blackbody radiation corresponding to each second temperature among the multiple different second temperatures is divided by the first radiation of the pixel at the second temperature to obtain the first emissivity of the pixel at the second temperature.

5. The measuring method according to claim 1, wherein: Determining the blackbody radiation amount of each pixel point in the working state according to the second radiation amount and the actual emissivity of each pixel point includes: The second radiation amount of each pixel point is divided by the actual emissivity of the pixel point to obtain the blackbody radiation amount of the pixel point in the working state.

6. The measuring method according to claim 1, characterized in that The chip is a chip with the back side opaque material removed, and the material includes at least one of the following: thermal interface material TIM, cover lid, and plastic packaging material; The chip being in the working state means that the chip is powered on and a heat sink is installed to dissipate heat.

7. The measuring method according to claim 1, characterized in that During the process of collecting the first radiation amount and the second radiation amount of each pixel point by using the infrared camera, the position of each pixel point remains unchanged.

8. The measurement method according to claim 1, characterized in that The infrared camera is a medium-wave infrared camera.

9. The measuring method according to claim 1, wherein: The plurality of different second temperatures are controlled by a semiconductor cooler (TEC) located under the chip, and the chip dissipates heat through the TEC in a working state.

10. The measurement method according to claim 1, characterized in that The multiple different second temperatures are controlled by a heat stage located below the chip, and the chip is cooled by a liquid cooling device located above the chip in a working state.

11. A device for measuring chip power map temperature distribution, characterized in that: The device includes an infrared camera and a data processing program; The infrared camera is used to collect the radiation amount of the black body at multiple different first temperatures; The data processing program is used to determine the corresponding relationship between blackbody radiation and temperature; The infrared camera is further used to collect the first radiation amount of each pixel point of the chip at a plurality of different second temperatures; The data processing program is further configured to determine, for each of the pixels, a first emissivity of the pixel at the second temperature based on the amount of blackbody radiation corresponding to each of the multiple different second temperatures and the first radiation of the pixel at the second temperature, thereby obtaining a plurality of first emissivities of each pixel corresponding one-to-one to the multiple different second temperatures; and determine an actual emissivity of each pixel based on the multiple first emissivities of each pixel. The infrared camera is further used to collect a second radiation amount of each pixel of the chip when the chip is in a working state; The data processing program is also used to determine the blackbody radiation of each pixel in the working state based on the second radiation of each pixel and the actual emissivity, and determine the temperature corresponding to the blackbody radiation of each pixel in the working state based on the correspondence between the blackbody radiation and the temperature, as the temperature of each pixel in the working state, thereby obtaining the chip powermap temperature distribution.

12. The measuring device according to claim 11, characterized in that The device further comprises a semiconductor cooler TEC located below the chip, for controlling the temperature of the chip to reach the plurality of different second temperatures and for dissipating heat from the chip in a working state.

13. The measuring device according to claim 11, characterized in that The device further includes a heat stage located below the chip and a liquid cooling device located above the chip, wherein the heat stage is used to control the temperature of the chip to reach the multiple different second temperatures, and the liquid cooling device is used to dissipate heat from the chip in a working state.

14. The measuring device according to claim 13, characterized in that The liquid cooling device includes at least one of the following: cooling liquid, an oil cooling shell, and a transmission window, wherein the transmission window is located above the chip and is in rigid contact with the chip, and the oil cooling shell is located around the chip to limit the flow of the cooling liquid around the chip and seal it.

15. The measuring device according to claim 11, characterized in that The device further comprises a printed circuit board (PCB) located below the chip, for supplying power to the chip in a working state.

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