Thermal conductivity and uniformity testing device for ceramic substrate and ceramic circuit board

Abstract

The invention discloses a ceramic substrate and ceramic circuit board thermal conductivity and uniformity testing device which comprises a testing cold table, a temperature measuring plate, a high-temperature pressing block and a cooling constant-temperature block, the temperature measuring plate is arranged on the lower surface of the testing cold table, and infrared array thermal imagers are arranged at the upper end and the lower end of the testing cold table respectively. The high-temperature pressing block, the cooling constant-temperature block and the testing cold table are all wrapped with heat preservation layers, and the computer comprises a control device, a temperature data acquisition device and a calculation and analysis device. The method is used for rapidly and accurately detecting the thermal conductivity and uniformity of the ceramic substrate and the ceramic circuit board.

Description

TECHNICAL FIELD

[0001] The application relates to a ceramic substrate and ceramic circuit board thermal conductivity and uniformity testing device and belongs to the field of electronic material testing devices. BACKGROUND

[0002] With the increasing integration and increasing functions of electronic circuits, the power and heat of various electronic products are increasing, and the traditional low-thermal-conductivity high-molecular substrate circuit board cannot meet the technical requirements in high-power-density electronic circuits. Ceramic materials have high thermal conductivity, excellent dielectric performance, environmental friendliness and high-temperature resistance, and are widely used in electronic circuits. The application in aerospace, power electronics, high-speed rail transportation and new energy vehicle electric drive is irreplaceable.

[0003] The commonly used thermal conductivity testing method of ceramic substrate and ceramic circuit board adopts a laser transient method. The principle is to irradiate a focused laser on the tested object, heat the tested object with the laser, and then test the temperature rise. Then the thermal conductivity of the measured object is obtained by calculation and analysis.

[0004] The laser transient method for testing thermal conductivity has the advantages of convenience and speed, but it has great defects and deficiencies for ceramic substrate and ceramic circuit board. First, the ceramic substrate and ceramic circuit board are two-dimensional planes with large area, and the size of the focused laser spot is less than millimeter level. The thermal conductivity of a certain point on the ceramic substrate and ceramic circuit board can only be tested at a time. Due to the complex manufacturing process, the material properties at different positions on the ceramic substrate and ceramic circuit board may not be uniform. The laser transient method cannot obtain the data of the thermal conductivity uniformity of the ceramic substrate and ceramic circuit board. Secondly, many ceramic substrate materials are transparent or semi-transparent, and the thinnest ceramic substrate is less than 0.1 millimeter. During testing, the laser can easily penetrate the ceramic substrate or ceramic circuit board. The laser irradiates on the temperature measuring plate and directly heats the temperature measuring plate instead of the heat conduction process of the ceramic substrate and ceramic circuit board, resulting in a very large error in the test result. The surface of the ceramic substrate and ceramic circuit board can be treated to be opaque, but the surface treatment operation is complex, and the treatment process and quality directly affect the test result. After testing, the reduction of the surface treatment of the ceramic substrate and ceramic circuit board is also very troublesome. The thermal steady flow method can solve the above problems, but the device for testing by using the thermal steady flow method is less on the market, and the test result error is large. Therefore, there is an urgent need for a testing device that can quickly and accurately detect the thermal conductivity and uniformity of the ceramic substrate and ceramic circuit board. SUMMARY

[0005] The application provides a ceramic substrate and ceramic circuit board thermal conductivity and uniformity testing device for quickly and non-destructively detecting the thermal conductivity and uniformity of the ceramic substrate and ceramic circuit board.

[0006] The application provides a testing device for thermal conductivity and uniformity of a ceramic substrate and a ceramic circuit board, which comprises a testing cold table, a temperature measuring plate, a high-temperature pressing block and a cooling constant-temperature block, and is characterized in that the lower surface of the testing cold table is provided with the temperature measuring plate, the upper end and the lower end of the testing cold table are respectively provided with infrared array thermal imagers, the high-temperature pressing block, the cooling constant-temperature block and the testing cold table are all wrapped with a heat preservation layer, and the computer comprises a control device, a temperature data acquisition device and a calculation and analysis device.

[0007] Preferably, the temperature measuring plate is composed of high-precision thermocouples or thermistor arrays and is arranged uniformly at multiple points in a two-dimensional plane.

[0008] Preferably, the thermocouple array of the temperature measuring plate is a K-type, S-type or B-type graduated thermocouple, the thermistor array of the temperature measuring plate is a Pt100 or Cu100 thermistor, and the thermocouples or thermistors are directly manufactured on the lower surface of the testing cold table through surface mounting or a two-dimensional film process.

[0009] Preferably, the ceramic substrate or the ceramic circuit board is self-heated by being electrified or is heated by the high-temperature pressing block.

[0010] Preferably, the testing cold table is made of copper, aluminum, iron or alloys thereof, and the surface of the testing cold table is plated with gold or nickel.

[0011] Preferably, the cooling device in the constant-temperature cooling table has a heat dissipation flow channel, and the cooling working medium in the cooling device is cooling water or cooling oil.

[0012] Preferably, the high-temperature pressing block has a constant-temperature heating device, and the constant-temperature heating device is selected from a constant-temperature electric heating device and a constant-temperature hot oil heating device.

[0013] Preferably, the control instruction device is connected with the testing cold table, the temperature measuring plate, the high-temperature pressing block, the cooling constant-temperature block and the infrared array thermal imager driving control device respectively.

[0014] Preferably, the data acquisition device is connected with the temperature measuring plate and the infrared array thermal imager data output port respectively.

[0015] Preferably, the calculation and analysis device is connected with the data acquisition device.

[0016] The application has the following beneficial effects:

[0017] The temperature measuring plate selects an array mode to measure the temperature of the to-be-measured sample, the distribution density of the array can be adjusted, the greater the density is, the more the obtained measurement data is, and the higher the accuracy of the data is;

[0018] The thermocouple array and the thermistor array can be selected and adjusted according to the testing requirements, and selecting appropriate testing components is conducive to improving the accuracy of the data.

[0019] The insulation layer is used to maintain a constant temperature for the cooling constant temperature block and the high temperature press block, reduce the statistical error of heat data caused by temperature volatilization, and enhance the accuracy of the test data;

[0020] The multiple heating methods for test samples allow for selection of heating methods in suitable environments, making testing more diverse, increasing the convenience of testing, and saving energy.

[0021] The test bench is made of copper, aluminum, iron and their alloys, which have good thermal conductivity and chemical stability, and are low in cost. In addition, gold or nickel plating on the surface of the test bench can prevent high-temperature oxidation when the test bench is heated.

[0022] The control command device, data acquisition device, and calculation and analysis device can perform automatic testing, improve data accuracy, quickly obtain test results, reduce manual operation, and avoid high temperature burns. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the structure of the testing device for the thermal conductivity and uniformity of ceramic substrates and ceramic circuit boards provided in this application.

[0024] Figure label:

[0025] 1 - Test sample, 2 - Test cold stage, 3 - Temperature measuring plate, 4 - Cooling constant temperature block, 5 - Temperature measuring plate, 6 - High temperature pressing block, 7 - Infrared array thermal imager, 8 - Infrared array thermal imager, 9 - Main control computer, 10 - Insulation layer. Detailed Implementation

[0026] The structural diagram of the testing device for thermal conductivity and uniformity of ceramic substrates and ceramic circuit boards is shown below. Figure 1 As shown: Test sample 1 is placed on test cold stage 2. A temperature measuring plate 3 is attached to the lower surface of test cold stage 2. The temperature measuring plate is made of thin-film thermocouple or resistance temperature detector (RTD) array. A cooling constant temperature block 4 contacts and cools test cold stage 2. Temperature measuring plates 3 and 5 are composed of thin-film thermocouples or RTD arrays. While the cooling constant temperature block 4 is cooling test cold stage 2, temperature measuring plate 5 is placed on test sample 1 to measure the temperature. An infrared array thermal imaging tester 7 is placed under test cold stage 2, and an infrared array thermal imaging tester 8 is placed above test cold stage 2. Test sample 1 is heated by self-heating or by contact heating through a high-temperature pressure block 6. The infrared array thermal imager records the temperature data of test sample 1 in real time, and the collected temperature data is collected by a data acquisition device. The high-temperature pressure block 6, the cooling constant temperature block 4, and the test cold stage 2 are all wrapped with an insulation layer 10 to maintain a constant temperature. A computer 9 is connected to the control device, data acquisition device, and calculation and analysis device to obtain the thermal conductivity and uniformity data of the test sample.

[0027] The working principle of the above technical solution is as follows:

[0028] Test sample 1 is a ceramic substrate or ceramic circuit board;

[0029] Test cold table 2 is used to place the ceramic substrate or ceramic circuit board, and the temperature of the test cold table 2 before testing and the low temperature of the ceramic substrate or ceramic circuit board are consistent;

[0030] Temperature measuring plate 3 is an array of high-precision thermocouples or thermal resistors attached, which can display multiple point temperatures on the lower surface of the ceramic substrate or ceramic circuit board simultaneously during testing;

[0031] Cooling constant temperature block 4 is used to cool the ceramic substrate and ceramic circuit board, so that the ceramic substrate or ceramic circuit board can be kept at a low temperature state before testing, which facilitates the heat conduction test. The cooling constant temperature block can move up and down under the control of the computer to contact the test cold table 2 to cool the ceramic substrate or ceramic circuit board;

[0032] Temperature measuring plate 5 is an array of high-precision thermocouples or thermal resistors attached, which is used to test the temperature of the upper surface of the ceramic substrate or ceramic circuit board. During testing, it can display multiple point temperatures on the upper surface of the ceramic substrate or ceramic circuit board simultaneously;

[0033] High-temperature pressing block 6 can move up and down under the control of the computer to contact the ceramic substrate or ceramic circuit board and heat the ceramic substrate or ceramic circuit board;

[0034] Infrared array thermal imager 7 is used to test the temperature and temperature distribution image of the lower surface of the ceramic substrate or ceramic circuit board;

[0035] Infrared array thermal imager 8 is used to test the temperature and temperature distribution image of the upper surface of the ceramic substrate or ceramic circuit board;

[0036] Master computer 9 is used to complete the control operation, obtain real-time test data and perform analysis and calculation, and obtain thermal conductivity and uniformity data.

[0037] Heat preservation layer 10 is used to keep the temperature of the cooling constant temperature block and the high-temperature pressing block constant to prevent temperature fluctuation from causing data errors.

[0038] A ceramic substrate or ceramic circuit board test sample 1 is placed on a test cooling stage 2. A temperature measuring plate 3 is attached to the lower surface of the test cooling stage 2. A cooling constant temperature block 4 contacts and cools the test cooling stage 2. While the test cooling stage 2 is being cooled at a constant temperature, a temperature measuring plate 5 is placed on the test sample 1 to measure its temperature. The temperature measuring plate is composed of a high-precision thin-film thermocouple or a thermal resistance array. An infrared array thermal imaging tester 7 is placed below the test cooling stage 2, and an infrared array thermal imaging tester 8 is placed above the test cooling stage 2. The test sample 1 is heated by electricity or by contact with a high-temperature pressure block 6. The infrared array thermal imaging testers 7 and 8 record the temperature images of the upper and lower surfaces of the test sample 1 in real time. The high-temperature pressure block 6, the cooling constant temperature block 4, and the test cooling stage 2 are all wrapped with a thermal insulation layer 10 to maintain a constant temperature. The temperature data and temperature image data measured by the temperature measuring plates 3 and 5, as well as the infrared array thermal imaging testers 7 and 8, are sent to a computer 9. The computer 9 records and analyzes the thermal conductivity and uniformity of the test sample 1. Computer 9 is responsible for the automatic control of the testing device and the recording and analysis of test data. The control command device is connected to the test cold stage, temperature measuring plate, high-temperature pressing block, cooling constant temperature block, and infrared array thermal imager drive control device, respectively, to control the movement and rotation of the test cold stage, temperature measuring plate, high-temperature pressing block, cooling constant temperature block, and infrared array thermal imager to complete the automatic operation of the test sample test. The data acquisition device is connected to the data output port of the temperature measuring plate and infrared array thermal imager, respectively, to continuously acquire the temperature data of the upper and lower surfaces of the test sample 1 in real time. The calculation and analysis device is connected to the data acquisition device to calculate the temperature data acquired by the data acquisition device, output the thermal conductivity and uniformity results of the test sample, and transmit the analysis results to computer 9. The computer 9 displays the calculated data on the monitor, and obtains the thermal conductivity and uniformity data of the test sample.

[0039] The effects of the above technical solution are as follows:

[0040] Through the structure of the aforementioned testing device, the insulation layer reduces heat loss from the sides of the heating and cooling blocks into the environment, ensuring that heat is mainly conducted through the sample, thereby improving measurement accuracy. Simultaneously, it makes the surface temperature of the heating and cooling blocks more uniform, helping to form a stable temperature gradient in the sample and achieve steady-state heat transfer. It also improves the energy efficiency of the entire testing system because it reduces ineffective energy consumption, allowing more heat to be conducted through the sample rather than absorbed by the environment. Furthermore, the time required for the system to reach steady state may be shortened, helping to establish a stable temperature field more quickly, reducing the impact of external environmental changes on test results, ensuring consistent test conditions for each test, and thus improving the repeatability of test results.

[0041] Example 2

[0042] In Example 1, the temperature measuring plate 3 is a high-precision thermocouple or resistance temperature detector array, which is distributed at multiple points on a two-dimensional plane to simultaneously measure the temperature at multiple points on the two-dimensional plane.

[0043] Test sample 1 is a ceramic substrate or ceramic circuit board. The material of the test sample is glass, alumina, aluminum nitride, silicon nitride, beryllium oxide, silicon oxide, zirconium oxide, and diamond. The thermal conductivity of the above test sample materials is several orders of magnitude higher than that of polymer-based materials, which is a key technical indicator for the application of ceramic materials in electronic circuit boards. In addition, semiconductor chips such as silicon, gallium nitride, silicon carbide, aluminum nitride, silicon nitride, and diamond, as well as components such as resistors, capacitors, and inductors, can be mounted on test sample 1. Alternatively, it can be a bare board without any chips or components mounted on it.

[0044] The ceramic substrate or ceramic circuit board to be tested is self-heating when powered on, or it can be heated by a high-temperature pressing block 6 or other uniform or non-uniform heat sources.

[0045] The test cold stage 2 is made of copper, aluminum, iron and their alloys, which have good thermal conductivity and chemical stability, and the material cost is relatively low. In addition, in order to prevent high-temperature oxidation during heating, the surface of the test cold stage 2 is plated with gold or nickel.

[0046] The thermocouples or resistance temperature detectors (RTDs) arrays are classified as Type K, Type S, and Type B thermocouples. Type K thermocouples are made of nickel-chromium and nickel-silicon alloys, exhibiting high stability and accuracy. They are one of the most commonly used thermocouple types in industry, suitable for temperature ranges from -200℃ to 1375℃. Type S thermocouples are made of platinum-rhodium alloys, possessing the highest accuracy and stability, and are typically used as standard thermocouples. Their long-term operating temperature can reach 1400℃, and they can withstand short-term temperatures up to 1600℃. Type B thermocouples are also made of platinum-rhodium alloys, but compared to other types, their thermoelectric potential at room temperature is extremely low, therefore compensation wires are generally not required during measurement. Type B thermocouples have a long-term operating temperature of 1600℃ and can withstand short-term temperatures up to 1800℃, and are replaced according to the test sample. The resistance temperature detector (RTD) is either Pt100 or Cu100. Pt100 indicates a resistance of 100 ohms at 0°C. Its resistance increases uniformly with temperature, but not in a simple direct proportional relationship; it tends more towards a parabola. It features high accuracy, suitability for neutral and oxidizing media, good stability, and a degree of non-linearity. Cu100 RTDs exhibit resistance changes with temperature, typically showing a linear relationship between resistance and temperature within the measurement range. Copper RTDs offer better linearity, lower price, lower resistivity, larger size, and slower thermal response. The appropriate RTD should be selected and replaced based on actual needs.

[0047] Thermocouples or resistance thermometers are assembled into a temperature measuring plate by surface mounting, or directly manufactured on the lower surface of the test cold stage 2 using two-dimensional thin film technology.

[0048] The constant temperature cooling stage 4 has a cooling device with heat dissipation channels inside. The cooling medium in the cooling device is cooling water or cooling oil. In this way, the temperature on one side of the test sample is controlled to form a stable temperature difference with the heat source on the other side. This is a necessary condition for realizing steady-state heat conduction in this invention. It helps to reduce edge effects and errors caused by ambient temperature fluctuations, ensures the reliability of experimental data, and makes heat mainly transferred along the direction perpendicular to the sample surface, thereby forming a one-dimensional heat flow in the sample. This simplifies the calculation process of thermal conductivity. In addition, since the steady-state method requires waiting for the material to reach thermal equilibrium, the cooling stage can help accelerate this process and shorten the test cycle.

[0049] The high-temperature press 6 has a constant-temperature electric heating device or a heating device with a heating channel inside. The high temperature is kept constant by constant-temperature electric heating or constant-temperature hot oil heating. In the steady-state heat flow method, the ideal situation is one-dimensional heat transfer. The high-temperature press helps to achieve this condition through uniform pressure distribution, ensuring good contact between the sample and the sensor, reducing contact thermal resistance, and helping to form a stable temperature field. This makes the calculation more simplified and accurate, thus providing accurate test results.

[0050] The testing of thermal conductivity and uniformity of ceramic substrates and ceramic circuit boards can be divided into two test states: high-temperature heat source contact heating and ceramic circuit board self-heating when powered on.

[0051] High-temperature heat source contact heating: The ceramic substrate or ceramic circuit board test sample 1 is placed on the test cold stage 2. The temperature measuring plate 5 with thin film thermocouples or resistance temperature detector arrays is placed on the ceramic substrate or ceramic circuit board 1. The temperature of the test cold stage 2 is set to the ambient temperature to reduce the influence of the ambient temperature on the test results. The cooling constant temperature block 4 contacts and cools the test cold stage 2. When the test cold stage 2 reaches the set temperature, the temperature measuring plate 5 with thin film thermocouples and resistance temperature detector arrays and the constant temperature cooling block 4 are removed. The infrared array thermal imaging tester 7 is placed under the test cold stage 2. The high-temperature pressure block 6 contacts and heats the ceramic substrate or ceramic circuit board 1. The main control computer 9 records the temperature and image of the ceramic substrate or ceramic circuit board 1 in real time and analyzes and calculates the thermal conductivity and uniformity of the ceramic substrate or ceramic circuit board 1.

[0052] Ceramic substrate or ceramic circuit board self-heating upon power-on: The ceramic substrate and ceramic circuit board 1 are placed on the test cold stage 2. The temperature measuring plate 5 with thin-film thermocouples and thermistor arrays is placed on the ceramic substrate or ceramic circuit board test sample 1. The temperature of the test cold stage 2 is set to the ambient temperature to reduce the influence of the ambient temperature on the test results. The cooling constant temperature block 4 contacts and cools the test cold stage 2. When the test cold stage 2 reaches the set temperature, the temperature measuring plate 5 with thin-film thermocouples and thermistor arrays and the constant temperature cooling block 4 are removed. An infrared array thermal imaging tester 7 is placed under the test cold stage 2. An array infrared thermal imager 7 is placed under the ceramic substrate or ceramic circuit board 1. The ceramic substrate or ceramic circuit board 1 self-heats upon power-on. The main control computer 9 records the temperature and image of the ceramic substrate or ceramic circuit board 1 in real time and analyzes and calculates the thermal conductivity and uniformity of the ceramic substrate or ceramic circuit board 1.

[0053] The effects of the above technical solution are as follows:

[0054] The temperature measuring plate uses an array to measure the temperature of the sample. The array density can be adjusted; a higher density yields more measurement data and higher accuracy. Thermocouple and resistance temperature detector (RTD) arrays can be selected and adjusted according to testing requirements, and choosing appropriate test components improves data accuracy. Multiple heating methods for the test sample allow for selection of the heating method suitable for the test sample environment, diversifying testing methods, increasing convenience, and saving energy. The test platform is made of copper, aluminum, iron, and their alloys, possessing good thermal conductivity and chemical stability, and is cost-effective. Furthermore, gold or nickel plating on the test platform surface prevents high-temperature oxidation during heating. Control command devices, data acquisition devices, and calculation and analysis devices enable automated testing, improving data accuracy, quickly obtaining test results, reducing manual operation, and avoiding burns from high temperatures.

[0055] The following are several testing procedures of this invention:

[0056] 1. Testing the thermal conductivity and uniformity of aluminum nitride ceramic substrates.

[0057] An aluminum nitride ceramic substrate 1 measuring 190 mm x 138 mm is placed on a test cold stage 2. A temperature measuring plate 5, which mounts thin-film thermocouples and a resistance temperature detector (RTD) array, is placed on the aluminum nitride ceramic substrate 1. The temperature of the test cold stage 2 is set to the ambient temperature of 20 degrees Celsius. A cooling constant temperature block 4 contacts and cools the test cold stage 2. When the temperature of the temperature measuring plate 5 shows 20 degrees Celsius, the temperature measuring plate 5 and the constant temperature cooling block 4 are removed. An infrared array thermal imaging tester 7 is placed under the test cold stage 2. A high-temperature pressure block 6, with its temperature set to 120 degrees Celsius, contacts and heats the aluminum nitride ceramic substrate 1.

[0058] The main control computer 9 records the temperature and image of the aluminum nitride ceramic substrate 1 in real time. When the heating time starts, the temperature plate array shows a temperature of 120 degrees Celsius after 5 minutes and 28 seconds. Analysis and calculation show that the thermal conductivity of the aluminum nitride ceramic substrate 1 is 182 Wm / K, and the thermal conductivity and temperature uniformity of the aluminum nitride ceramic substrate 1 are 98.5%.

[0059] 2. Testing the thermal conductivity and uniformity of the silicon nitride ceramic substrate.

[0060] A silicon nitride ceramic substrate 1 measuring 190 mm x 138 mm is placed on a test cold stage 2. A temperature measuring plate 5, which mounts thin-film thermocouples and a resistance temperature detector (RTD) array, is placed on the silicon nitride ceramic substrate 1. The temperature of the test cold stage 2 is set to the ambient temperature of 20 degrees Celsius. A cooling constant temperature block 4 contacts and cools the test cold stage 2. When the temperature of the temperature measuring plate 5 shows 20 degrees Celsius, the temperature measuring plate 5 and the constant temperature cooling block 4 are removed. An infrared array thermal imaging tester 7 is placed under the test cold stage 2. A high-temperature pressure block 6, with its temperature set to 120 degrees Celsius, contacts and heats the silicon nitride ceramic substrate 1.

[0061] The main control computer 9 records the temperature and image of the silicon nitride ceramic substrate 1 in real time. When the heating time starts, the temperature plate array shows a temperature of 120 degrees Celsius after 9 minutes and 252 seconds. Analysis and calculation show that the thermal conductivity of the silicon nitride ceramic substrate 1 is 82 Wm / K, and the thermal conductivity and temperature uniformity of the silicon nitride ceramic substrate 1 are 92.5%.

[0062] 3. Test the thermal conductivity and uniformity of the aluminum nitride ceramic circuit board.

[0063] A 70mm x 58mm aluminum nitride ceramic circuit board is placed on test cold stage 2. A temperature measuring plate 5, which mounts thin-film thermocouples and a resistance temperature detector (RTD) array, is placed on the aluminum nitride ceramic circuit board 1. The temperature of test cold stage 2 is set to the ambient temperature of 20 degrees Celsius. A cooling constant temperature block 4 contacts and cools test cold stage 2. When the temperature of the temperature measuring plate 5 shows 20 degrees Celsius, the temperature measuring plate 5 and the constant temperature cooling block 4 are removed. An infrared array thermal imaging tester 7 is placed under test cold stage 2, and the aluminum nitride ceramic circuit board is powered on.

[0064] The main control computer 9 records the temperature and image of the aluminum nitride ceramic circuit board 1 in real time. The timing starts from when the aluminum nitride ceramic circuit board is powered on. When the power-on operation is 12 minutes and 38 seconds, the temperature measuring plate array shows a maximum temperature of 82 degrees Celsius. Analysis and calculation show that the thermal conductivity of the aluminum nitride ceramic circuit board 1 is 252 Wm / K and the temperature uniformity of the aluminum nitride ceramic circuit board is 58.8%.

[0065] All instructions involved in this invention are existing technologies in the field. This invention does not improve any software programs or methods. This invention only designs the hardware structure of intelligent tool control and management devices. The hardware structure implementation instructions are all based on existing methods or software program design books, manuals or product manuals by those skilled in the art, combined with the functions involved in the principles and effects of this invention, and can be implemented by writing their own programs.

[0066] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the claims.

Claims

1. A testing device for the thermal conductivity and uniformity of ceramic substrates and ceramic circuit boards, comprising a test cold stage, a temperature measuring plate, a high-temperature pressing block, and a cooling constant-temperature block, characterized in that, A temperature measuring plate is arranged on the lower surface of the test cold stage, and infrared array thermal imagers are arranged at the upper and lower ends of the test cold stage, respectively. The high-temperature pressing block, the cooling constant temperature block and the test cold stage are all wrapped with a heat insulation layer. The computer includes a control device, a temperature data acquisition device and a calculation and analysis device.

2. The device for testing the thermal conductivity and uniformity of ceramic substrates and ceramic circuit boards according to claim 1, characterized in that, The temperature measuring plate is composed of a high-precision thermocouple or resistance temperature detector array, which is uniformly arranged at multiple points on a two-dimensional plane.

3. The ceramic substrate and ceramic circuit board thermal conductivity and uniformity testing device according to claim 2, wherein the thermocouple array of the temperature measuring plate is a K-type, S-type, and B-type graded thermocouple, and the resistance thermometer array of the temperature measuring plate is a Pt100 or Cu100 resistance thermometer, and the thermocouples or resistance thermometers are directly manufactured on the lower surface of the test cold stage 2 by surface mounting or two-dimensional thin film process.

4. The ceramic substrate and ceramic circuit board thermal conductivity and uniformity testing device according to claim 1, wherein the ceramic substrate or ceramic circuit board is self-heating when powered on, or it may be heated by a high-temperature pressing block.

5. The ceramic substrate and ceramic circuit board thermal conductivity and uniformity testing device according to claim 1, wherein the test cold stage is made of copper, aluminum, iron and their alloys, and the surface of the test cold stage is plated with gold or nickel.

6. The ceramic substrate and ceramic circuit board thermal conductivity and uniformity testing device according to claim 1, wherein the constant temperature cooling stage has a cooling device with heat dissipation channels inside, and the cooling medium in the cooling device is cooling water or cooling oil.

7. The ceramic substrate and ceramic circuit board thermal conductivity and uniformity testing device according to claim 1, wherein the high-temperature pressing block has a constant temperature heating device inside, which can be a constant temperature electric heating device or a constant temperature hot oil heating device.

8. The ceramic substrate and ceramic circuit board thermal conductivity and uniformity testing device according to claim 1, wherein the control command device is connected to the test cold stage, the temperature measuring plate, the high temperature pressing block, the cooling constant temperature block and the infrared array thermal imager drive control device respectively.

9. The ceramic substrate and ceramic circuit board thermal conductivity and uniformity testing device according to claim 8, wherein the data acquisition device is connected to the temperature measuring plate and the data output port of the infrared array thermal imager respectively.

10. The ceramic substrate and ceramic circuit board thermal conductivity and uniformity testing device according to claim 9, wherein the calculation and analysis device is connected to the data acquisition device.

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