Conductivity multichannel parallel testing device and testing method

Abstract

The invention discloses a conductivity multichannel parallel test device and test method, and belongs to the technical field of conductivity test based on probe test. The problem that in the prior art, a traditional conductivity multi-channel parallel testing device and testing method are low in testing efficiency is solved. The invention provides a conductivity multichannel parallel testing device, a main control end of the conductivity multichannel parallel testing device is respectively connected with a temperature control system, a multichannel signal switching device and a current signal collecting system, and a low-temperature heating stage is respectively connected with the temperature control system, the multichannel signal switching device and the current signal collecting system. The sample table and the temperature control system are respectively connected with the temperature sensor, the heating device and the cooling device, a light through hole is formed in the middle of the sample table, and the multi-channel test fixture comprises a probe table and 17 probes on the probe table. The conductivity testing efficiency is effectively improved, the automation degree is high, and the method can be applied to measuring the conductivity of multiple samples at the same time.

Description

Technical Field

[0001] The invention relates to a conductivity multi-channel parallel testing device and a testing method, and belongs to the technical field of conductivity testing based on probe testing. Background Art

[0002] According to quantum mechanics, electrons in atoms or crystals are distributed across discrete energy levels. When the energy gaps between a large number of energy levels are very small, the closely spaced energy levels are collectively referred to as energy bands. Electrons fill the energy bands from the lowest energy level upwards, with only electrons near or above the Fermi level being able to move freely. Electrons easily transition near the Fermi level, and the specific domain structure in dielectric materials can reduce the band gap energy, causing the material to conduct electricity under certain conditions. Conductivity is the most fundamental characterization method for studying dielectric materials, and its results determine the material's potential and application environments. Currently, existing technology allows for room-temperature testing, and testing equipment is already available. With advances in conductivity measurement, researchers have developed testing systems with various voltage ranges, such as room temperature and 0-100V, tailored to their needs.

[0003] At the same time, dielectric materials are widely used in medicine, ocean, optics, aerospace and other fields. Exploring high-performance dielectric materials and their high-performance origins and performance regulation mechanisms has always been a hot topic and a difficult problem in the field of materials, and has important scientific research and application value. In the application engineering of dielectric materials, it is necessary to characterize their relevant properties, among which the most basic property is the conductivity of the material. For information functional materials, studying their conductivity characteristics in different temperature zones and different external field environments is one of the most important methods to understand the interaction mechanism between material polarization, microscopic mechanism, material composition, structure and performance. Therefore, how to obtain a conductivity measurement solution with a wider temperature range, more accuracy and multi-channel parallel testing has become the focus and difficulty of researchers in related fields. However, the existing conductivity multi-channel parallel testing device and test method have the following problems: (1) The system integration is not high, the operation is complex, the degree of automation is low, and most of the measurements are manual; (2) The test sample can only be tested one sample at a time. As the voltage changes, it is a long test process. A single station cannot meet a large number of test needs, and the test efficiency is low; (3) The test process cannot be heated and cooled in time, and it does not have the test function of the low-temperature part.

[0004] In summary, in order to better characterize the basic properties of dielectric materials, it is necessary to establish a conductivity multi-channel parallel testing device and testing method with a higher degree of automation, a test temperature range that meets the requirements of most materials, higher test efficiency, and a larger voltage range. Summary of the Invention

[0005] A brief overview of the present invention is provided below to provide a basic understanding of certain aspects of the present invention. It should be understood that this overview is not an exhaustive overview of the present invention. It is not intended to identify key or important aspects of the present invention, nor is it intended to limit the scope of the present invention. Its purpose is simply to present certain concepts in a simplified form as a prelude to the more detailed description discussed later.

[0006] In view of this, in order to solve the problem of low testing efficiency of the traditional conductivity multi-channel parallel testing device and testing method in the prior art, the present invention provides a conductivity multi-channel parallel testing device and testing method.

[0007] Technical solution 1 is as follows: a conductivity multi-channel parallel testing device, including a main control terminal, a temperature control system, a multi-channel signal switching device, a current signal collection system, and a high and low temperature heating stage;

[0008] The main control end is connected to the temperature control system, the multi-channel signal switching device and the current signal collection system respectively;

[0009] The high and low temperature heating stages are respectively connected to the temperature control system, the multi-channel signal switching device and the current signal collection system.

[0010] Furthermore, the high and low temperature hot stage includes a sample stage, a temperature sensor, a heating device, a cooling device and a high and low temperature clamp. The sample stage and the temperature control system are respectively connected to the temperature sensor, the heating device and the cooling device. A light hole is provided in the middle of the sample stage.

[0011] Furthermore, the high and low temperature fixture includes a probe station and 17 probes thereon, wherein one probe is connected to an electrode surface of 16 samples on the sample station as a common end, and the other 16 probes are respectively connected to another electrode surface of the 16 samples, and the 16 probes are respectively connected to the 16 channels of the multi-channel signal switching device. The 16 probes are also connected to the current signal collection system. The on and off of the loop is controlled by the multi-channel signal switching device, and the current signal is collected by the current signal collection system to realize multi-channel testing of the samples.

[0012] Technical Solution 2: A conductivity multi-channel parallel testing method, using a conductivity multi-channel parallel testing device described in Technical Solution 1, comprising the following steps:

[0013] S1. Set the minimum test temperature, maximum test temperature, and heating / cooling rate through the temperature control system;

[0014] S2. Clamp 16 samples to be tested in a multi-channel fixture. The test program stored in the main control terminal sends instructions to the temperature control system via the serial port line, causing the high and low temperature hot plate to reach the target temperature and setting the voltage applied to the sample terminals through the high and low temperature hot plate.

[0015] S3. The master terminal controls the multi-channel signal switching device through the serial port line to connect the channel, and uses the current signal collection system to measure the current of the sample and transmit it back to the master terminal through the serial port line;

[0016] S4. The multi-channel signal switching device disconnects the current channel, connects the next channel, and continues the above steps to obtain the current values of 16 samples at a certain temperature. As the test temperature increases / decreases, the above steps are continued to obtain the measured current values of 16 samples at different temperatures and different voltages;

[0017] S5. Obtain the conductivity of the sample based on the measured current value and the conductivity formula;

[0018] Specifically: The conductivity formula is expressed as:

[0019]

[0020] Where I is the measured current value, U is the voltage applied across the sample, l is the sample thickness in the direction of applied voltage, and A is the surface area of the sample end.

[0021] The beneficial effects of the present invention are as follows: the present invention realizes temperature regulation during the test process by designing a temperature sensor, a heating device, and a cooling device in a high and low temperature hot stage, and combines the temperature control system, while having the test function of the low temperature part; the present invention is based on centralized control of the main control end, with high integration, simple operation, and a high degree of automation. No manual testing is required, and the test results can be obtained by inputting preset parameters; the present invention solves the problem that the conductivity test device can only test one sample at a time, greatly improving the test efficiency, and further improving the accuracy through the single-channel connection of the multi-channel signal switching device and the current signal collection system. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0023] Figure 1 It is a structural schematic diagram of a multi-channel parallel conductivity testing device;

[0024] Figure 2 Schematic diagram of a flow chart of a multi-channel parallel conductivity testing method;

[0025] Figure 3 is a schematic diagram of an embodiment housing of an electrometer;

[0026] Figure 4 Schematic diagram of the housing of a temperature control box;

[0027] Figure 5 Schematic diagram of the structure of an embodiment of a high and low temperature hot stage;

[0028] Figure 6 This is a schematic diagram of the structure of an embodiment of a multi-channel parallel conductivity testing device;

[0029] Figure 7 An example graph of test results is shown.

[0030] Description of the accompanying drawings: 1. Main control end; 2. Temperature control system; 3. Multi-channel signal switching device; 4. Current signal collection system; 5. High and low temperature hot plate; 6-31. Port; 32. Probe station; 33. Sample stage; 34. Liquid nitrogen circulation system; 35. Common port; 36. Temperature control end data cable; 37. Hot plate water cooling circulation pipeline; 38. Heating silver ingot with insulation coating; 39. Hot plate power supply line. DETAILED DESCRIPTION

[0031] To make the technical solutions and advantages of the embodiments of the present invention more clearly understood, exemplary embodiments of the present invention are further described in detail below with reference to the accompanying drawings. It should be noted that the embodiments described are only a portion of the embodiments of the present invention, and are not an exhaustive list of all embodiments. It should be noted that the embodiments of the present invention and the features thereof may be combined with each other unless they conflict.

[0032] Example 1: Reference Figure 1-Figure 7 Detailed description of this embodiment, a conductivity multi-channel parallel testing device includes a main control terminal 1, a temperature control system 2, a multi-channel signal switching device 3, a current signal collection system 4, and a high and low temperature heating stage 5;

[0033] The main control terminal 1 is connected to the temperature control system 2, the multi-channel signal switching device 3 and the current signal collection system 4 respectively;

[0034] The high and low temperature heating stage 5 is connected to the temperature control system 2 , the multi-channel signal switching device 3 and the current signal collection system 4 respectively.

[0035] Specifically, the present invention mainly includes two parts: temperature control and current collection. The temperature control part is mainly implemented by a heating device and a cooling device, and the current collection part is implemented by a sample high and low temperature fixture, a multi-channel signal switching device 3, etc. The temperature control system 2, the multi-channel signal switching device 3 and the current signal collection system 4 are connected to the main control terminal 1, i.e., a PC, through a communication port and a communication serial port line. Under the control of the software in the PC, the control-test unit is coordinated and linked, and the current generated by the pyroelectric effect of the sample can be measured;

[0036] The main control terminal 1 is connected to the multi-channel signal switching device 3 through the RS-232 serial port. The function of the multi-channel signal switching device 3 is to receive the instructions sent by the main control terminal 1 through the serial port to switch the signal. The main control chip U2 adopts the domestic microcontroller (MCU) model STC12C2052 of Hongjing Technology. The main function of the chip U2 is to convert the RS232 level and TTL level. The microcontroller processes the signal after the level conversion of U1 and parses the instructions sent by the host. According to the instructions, the corresponding input and output ports (IO) are controlled to control the signal relay, thereby realizing signal switching. In order to ensure that the signal is not interfered with, the signal switching board has shielded the signal line.

[0037] The main control terminal 1 is connected to the temperature control system 2 and the current signal collection system 4 respectively through the RS-485 serial port.

[0038] Furthermore, the high and low temperature hot stage 5 includes a sample stage 33, a temperature sensor, a heating device, a cooling device and a high and low temperature clamp. The sample stage 33 and the temperature control system 2 are respectively connected to the temperature sensor, the heating device and the cooling device. A light hole is provided in the middle of the sample stage 33.

[0039] Furthermore, the high and low temperature fixture includes a probe station and 17 probes thereon, wherein one probe is connected to an electrode surface of 16 samples on the sample station 33 as a common end, and the other 16 probes are respectively connected to another electrode surface of the 16 samples, and the 16 probes are respectively connected to the 16 channels of the multi-channel signal switching device 3. The 16 probes are also connected to the current signal collection system 4. The on and off of the circuit is controlled by the multi-channel signal switching device 3, and the current signal is collected by the current signal collection system 4 to realize multi-channel testing of the sample.

[0040] Specifically, in this embodiment, the cooling device is a liquid nitrogen circulation system 34, the current signal collection system 4 is an electrometer, and the temperature sensor and the heating device are implemented by a temperature control box. Figure 5 , port 6 of the high and low temperature hot stage is connected to the interface of the common port 35, ports 7 to 22 are the input / output ports of current / voltage, which are connected to the probe internally and the electrometer externally. The voltage at both ends of the sample is controlled by the electrometer and the probe stage 32, ports 23 to 24 are the ports of the temperature control end data line 36, which are connected to the temperature control box internally and the temperature control system externally to realize real-time temperature acquisition, ports 25 to 29 are the interfaces of the hot stage water cooling circulation pipeline 37, which ensures the stability of the structure and performance of the hot stage when the sample stage 33 is in the high temperature state, ports 29 to 30 are the input / output circulation ports of the liquid nitrogen circulation system 34, which are connected to the liquid nitrogen circulation system 34 internally and the temperature control system externally to realize the temperature control of the low temperature part, port 31 is the interface of the hot stage power line 39, which serves as a power supply and signal transmission port. By setting the target temperature and the necessary information of the heating and cooling slope, a stable heating and cooling / constant temperature environment can be achieved.

[0041] Example 2: Reference Figure 1-Figure 7 This embodiment is described in detail. A conductivity multi-channel parallel testing method, using the conductivity multi-channel parallel testing device described in Example 1, includes the following steps:

[0042] S1. Set the minimum test temperature, maximum test temperature, and heating / cooling rate through the temperature control system. The test temperature can be fixed or variable.

[0043] S2. Clamp the 16 samples to be tested in the multi-channel fixture and click Start. The test program stored in the main control terminal sends instructions to the temperature control system via the serial port line, causing the high and low temperature hot plate to reach the target temperature and setting the voltage applied to the sample terminals through the high and low temperature hot plate.

[0044] S3. The master terminal controls the multi-channel signal switching device through the serial port line to connect the channel, and uses the current signal collection system to measure the current of the sample and transmit it back to the master terminal through the serial port line;

[0045] S4. The multi-channel signal switching device disconnects the current channel, connects the next channel, and continues the above steps to obtain the current values of 16 samples at a certain temperature. As the test temperature increases / decreases, the above steps are continued to obtain the measured current values of 16 samples at different temperatures and different voltages;

[0046] S5. Obtain the conductivity of the sample based on the measured current value and the conductivity formula;

[0047] Specifically: The conductivity formula is expressed as:

[0048]

[0049] Where I is the measured current value, U is the voltage applied across the material, l is the sample thickness in the direction of applied voltage, and A is the surface area of the sample end.

[0050] Specifically, in this embodiment, the minimum test temperature is -200°C, the maximum test temperature is 600°C, the heating / cooling rate is 0.01°C / min to 150°C / min, the recording interval is ≥0.1°C, the number of cycles is n times, and the voltage applied across the sample is 0.005V to 1000V;

[0051] For the same material, the better the conductivity, the greater the current measured at the same voltage. In order to characterize the degree of conductivity of different materials, the conductivity σ is defined;

[0052] The conductivity σ is expressed as:

[0053] σ=1 / ρ

[0054] Where ρ is the resistivity. The greater the conductivity, the stronger the conductivity of the material. The direct method is used to characterize the conductive properties of the material. By applying a voltage across the material, the current value I of the sample is directly measured to obtain the curve of current versus voltage. The conductivity σ is calculated using the conductivity formula.

[0055] The above-mentioned combined conductivity multi-channel parallel test device is used to test the pyroelectric current of the sample, and the pyroelectric coefficient of the sample can be measured by conversion;

[0056] The present invention has a multi-channel 16-channel conductivity test function, which can complete wide temperature range and low current testing. The specific parameters are as follows:

[0057] Temperature range: -200℃~600℃;

[0058] Current range: 0.0001pA~20mA;

[0059] Voltage range: 0.005V~1000V;

[0060] Number of samples: 16 samples can be tested simultaneously;

[0061] refer to Figure 7 , current represents the measured current value, and voltage represents the voltage applied across the material.

[0062] Although the present invention has been described with respect to a limited number of embodiments, it will be apparent to those skilled in the art, having benefit of the foregoing description, that other embodiments are contemplated within the scope of the invention thus described. Furthermore, it should be noted that the language used in this specification has been selected primarily for readability and didactic purposes, rather than for the purpose of explaining or limiting the subject matter of the present invention. Consequently, many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the appended claims. The disclosure of the present invention is intended to be illustrative rather than restrictive of the scope of the invention, which is defined by the appended claims.

Claims

1. A conductivity multi-channel parallel testing device, characterized in that: It includes a main control terminal (1), a temperature control system (2), a multi-channel signal switching device (3), a current signal collection system (4), and a high and low temperature heating stage (5); The main control end (1) is connected to the temperature control system (2), the multi-channel signal switching device (3) and the current signal collection system (4) respectively; The high and low temperature heating stage (5) is respectively connected to the temperature control system (2), the multi-channel signal switching device (3) and the current signal collection system (4).

2. The conductivity multi-channel parallel testing device according to claim 1, characterized in that: The high and low temperature hot stage (5) comprises a sample stage (33), a temperature sensor, a heating device, a cooling device and a high and low temperature clamp; the sample stage (33) and the temperature control system (2) are respectively connected to the temperature sensor, the heating device and the cooling device; a light hole is provided in the middle of the sample stage (33).

3. The conductivity multi-channel parallel testing device according to claim 2, characterized in that: The high and low temperature fixture includes a probe table (32) and 17 probes thereon, wherein one probe is connected to one electrode surface of 16 samples on the sample table (33) as a common end, and the other 16 probes are respectively connected to the other electrode surfaces of the 16 samples, and the 16 probes are respectively connected to the 16 channels of the multi-channel signal switching device (3). The 16 probes are also connected to the current signal collection system (4). The on-off of the circuit is controlled by the multi-channel signal switching device (3), and the current signal is collected by the current signal collection system (4), thereby realizing multi-channel testing of the sample.

4. A multi-channel parallel conductivity testing method, characterized in that: The multi-channel parallel conductivity testing device according to any one of claims 1 to 3 comprises the following steps: S1. Set the minimum test temperature, maximum test temperature, and heating / cooling rate through the temperature control system; S2. Clamp 16 samples to be tested in a multi-channel fixture. The test program stored in the main control terminal sends instructions to the temperature control system via the serial port line, causing the high and low temperature hot plate to reach the target temperature and setting the voltage applied to the sample terminals through the high and low temperature hot plate. S3. The master terminal controls the multi-channel signal switching device through the serial port line to connect the channel, and uses the current signal collection system to measure the current of the sample and transmit it back to the master terminal through the serial port line; S4. The multi-channel signal switching device disconnects the current channel, connects the next channel, and continues the above steps to obtain the current values of 16 samples at a certain temperature. As the test temperature increases / decreases, the above steps are continued to obtain the measured current values of 16 samples at different temperatures and different voltages; S5. Obtain the conductivity of the sample based on the measured current value and the conductivity formula; Specifically: The conductivity formula is expressed as: Where I is the measured current value, U is the voltage applied across the sample, l is the sample thickness in the direction of applied voltage, and A is the surface area of the sample end.

Images