CN204228824U - The star measurement mechanism of bulk conductivity under dielectric material thermograde - Google Patents

Abstract

The utility model discloses a device for measuring the electrical conductivity of the lower body of a star medium material temperature gradient, and relates to the field of electrical conductivity measuring devices for the medium material; There are at least four metal layers in the measured dielectric material; each metal layer is provided with at least one metal sheet, and the metal sheets between the upper and lower metal layers have the same structure and corresponding positions; each metal sheet edge leads a The lead wire is connected to the voltage and current acquisition circuit, and the adjacent upper and lower metal sheets form a pair of test electrodes; the heat source is located on the upper part of the measured dielectric material; the temperature acquisition device includes a temperature sensor, a temperature acquisition circuit, and a temperature display circuit. The temperature sensor is placed in the middle dielectric layer of the test electrode formed by two adjacent upper and lower metal sheets, the temperature sensor is connected to the temperature acquisition circuit, and the temperature acquisition circuit is connected to the temperature display circuit.

Description

Measuring device for bulk conductivity of dielectric materials used in satellites under temperature gradient

technical field

The utility model relates to the technical field of a dielectric material conductivity measuring device.

Background technique

The on-orbit failure cases of spacecraft tell us that the electrification effect in the medium has become an important potential threat to the high reliability and long-life operation of spacecraft. The electrification inside the spacecraft means that high-energy charged particles in space break through the protective layer of the spacecraft, penetrate and deposit inside the medium, thereby causing the medium to generate high potential and strong electric field. Internal electrification can easily lead to the degradation of dielectric material performance, interfere with the normal operation of the circuit system, and in severe cases, dielectric breakdown discharge may occur, which may cause permanent failure of the spacecraft. The conductivity of the medium is a key parameter to determine the internal charging effect. The smaller the conductivity, the larger the charging time constant in the medium, and the more serious the corresponding discharge threat. Temperature is a sensitive parameter that affects electrical conductivity, and the temperature of the space environment varies widely. Therefore, analyzing the dependence of material electrical conductivity on temperature is of great significance for accurately assessing the hazard of internal electrification.

At present, existing studies have focused on the internal charge effect of dielectric materials at a single temperature, because the main consideration is the internal charge of the star, and the star has temperature control, and temperature fluctuations can be ignored. For the exposed medium structure of the spacecraft, such as the satellite antenna support, it is necessary to analyze the law of internal charge under the existence of temperature gradient. The polymer insulating dielectric material used for spacecraft itself is a poor conductor of heat. It is in a cool and dark space environment, and there must be a temperature gradient distribution between the light and the dark side. The internal charging situation is obviously different. However, the research in this area is still blank, and the corresponding test device has not been reported.

Utility model content

The technical problem to be solved by the utility model is to provide a measuring device for the body conductivity under the temperature gradient of the medium material used for satellites, which can realize the measurement of the body conductivity at different positions under the temperature gradient of the medium material, and can investigate the temperature change at different illumination angles Range, intuitive, convenient and accurate test, high test efficiency, simple structure, easy to implement. It provides a feasible test plan for investigating the electrical conductivity and thermal properties of dielectric materials, and provides reliable input parameters for the evaluation of the internal electrification effect of satellite exposed media, which is of great significance for accurate evaluation of internal electrification hazards.

In order to solve the problems of the technologies described above, the technical solution adopted by the utility model is:

A device for measuring the conductivity of the dielectric material under temperature gradient for satellites, including a heat source, a temperature acquisition device, a voltage and current acquisition circuit, and at least four layers of metal arranged in the thickness direction in the dielectric material to be measured by using a multilayer circuit board processing technology layer; each metal layer is provided with at least one metal sheet, and the metal sheets between the upper and lower metal layers have the same structure and corresponding positions; a lead wire is drawn from the edge of each metal sheet, and the lead wire is connected to the voltage and current acquisition circuit. The adjacent upper and lower metal sheets form a pair of test electrodes; the heat source is located on the upper part of the measured dielectric material and irradiates the upper surface of the measured dielectric material at a certain angle; the temperature acquisition device includes a temperature sensor, a temperature acquisition circuit, A temperature display circuit, the temperature sensor is placed in the middle dielectric layer of the test electrode formed by two adjacent upper and lower metal sheets, the temperature sensor is connected to the temperature acquisition circuit, and the temperature acquisition circuit is connected to the temperature display circuit.

In a further technical solution, the measured dielectric material is also covered with a heat insulation layer.

In a further technical solution, a low-temperature layer is laid on the bottom of the measured dielectric material.

In a further technical solution, the low temperature layer is a dry ice layer.

In a further technical solution, the metal sheet is a copper sheet.

In a further technical solution, the heat source is an infrared heating lamp array or a solar simulator.

In a further technical solution, the measured dielectric material is one of epoxy resin, polyimide or polytetrafluoroethylene or a modified dielectric material of one of them, and the modification is mainly through doping glass A new dielectric material formed of powder, glass cloth and other materials.

The beneficial effects of adopting the above technical scheme are: the measurement of the electrical conductivity under the temperature gradient of the dielectric material is realized, the real-time change of the internal temperature and electrical conductivity of the dielectric material under different temperature gradients can be investigated, and the temperature variation range at different illumination angles can be investigated. , to provide a feasible test plan for investigating the electrical conductivity and thermal properties of dielectric materials, and to provide reliable input parameters for the evaluation of the internal electrification effect of satellite exposed media; analysis of the dependence of material conductivity on temperature is of great significance for accurate assessment of internal electrification hazards ; The utility model has simple structure and is easy to implement. Compared with the test electrode exposed in the air in the method of testing the conductivity of the body under the existing single temperature, the test electrode sheet is located inside the dielectric material due to the use of multilayer circuit board processing technology. , to avoid the electrode being affected by humidity, air, etc. to form an interference current, the electrode has good anti-interference performance, and the test result is more accurate; and the heat source irradiates the measured dielectric material, so that the measured dielectric material has a temperature gradient, and in A temperature sensor is added to the medium material to be tested, and the conductivity of the medium material at various temperatures can be measured in one experiment, which reduces the test steps, saves test time, and improves test efficiency.

Description of drawings

Fig. 1 is the structural representation of embodiment 1 of the present invention;

Fig. 2 is a schematic structural view of the metal sheet in Fig. 1;

Fig. 3 is the circuit schematic diagram of the voltage and current acquisition circuit in Fig. 1;

4 is a schematic structural view of a metal layer in Embodiment 2 of the present invention;

In the drawings: 1. dielectric material, 2. metal sheet, 3. heat insulation layer, 4. heat conducting plate, 5. heat source, 6. dry ice layer, 7. lead wire, 8. temperature sensor, 9. pin.

Detailed ways

Below in conjunction with accompanying drawing and specific embodiment, the utility model is described in further detail.

Example 1

As shown in Figure 1, the measurement device for the lower body conductivity of the star with a dielectric material temperature gradient includes a heat source 5, a temperature acquisition device, a voltage and current acquisition circuit, and a multi-layer circuit board processing technology is installed in the measured dielectric material along the thickness direction. of 6 metal layers. The measured dielectric material is one of epoxy resin, polyimide or polytetrafluoroethylene or one of the modified dielectric materials. The modified dielectric material is mainly obtained by doping glass powder, glass cloth and other materials. A new dielectric material is formed, and the measured dielectric material is made into a cube shape. Each metal layer is provided with a metal sheet 2 with an area of S, each metal sheet 2 is a circular copper sheet of the same size, the center of the metal sheet 2 is on a straight line, and the diameter of the metal sheet 2 is close to the measured The length of the side of the dielectric material 1 is to increase the contact area between the metal sheet 2 and the measured dielectric material 1 and improve the utilization rate of the metal sheet 2 . The copper sheet is extremely thin and has good thermal conductivity. Therefore, the temperature of the dielectric material in contact with the copper sheet can be guaranteed to be uniform, and the heat conduction effect of the copper sheet on the measured dielectric material in the depth direction can be ignored. The adjacent upper and lower metal sheets 2 form a pair of test electrodes.

As shown in Figure 2, each metal sheet 2 edge is provided with a pin 9, and the pin 9 is connected with the lead wire 7, and the lead wire 7 is connected with the voltage and current acquisition circuit, and the edge of the pin 9 is smooth, so as to prevent the test voltage from forming a strong electric field at the end. The orientation of the pins 9 of the layers is different to ensure that the effective electrode area formed by the metal sheet 2 is still the area of the wafer.

The heat source 5 is located on the upper part of the measured dielectric material 1 and irradiates the upper surface of the measured dielectric material 1 at a certain angle. The heat source 5 uses an infrared lamp array to irradiate the upper surface of the measured dielectric material. The measured dielectric material is surrounded by a thermal insulation layer 3, which can be made of foam, asbestos and other materials. The thickness of the thermal insulation layer 3 should be uniform, so that the thermal insulation of the measured dielectric material is the same. A heat conduction plate 4 is provided at the bottom, and a dry ice layer 6 is laid on the bottom of the heat conduction plate 4 . In this way, the heat conduction direction of the measured dielectric material is vertically downward along the thickness direction, forming a vertically downward temperature gradient.

The temperature acquisition device includes a temperature sensor 8, a temperature acquisition circuit, and a temperature display circuit. The temperature sensor 8 is placed in the intermediate medium layer of the test electrode formed by the adjacent upper and lower metal sheets 2, and the temperature sensor 8 is connected with the temperature acquisition circuit. The temperature acquisition circuit is connected with the temperature display circuit. The temperature sensor 8 adopts DS18B20, which has the characteristics of small size (3mm), low hardware overhead, strong anti-interference ability and high precision. DS18B20 does not require any peripheral components in use, all sensing components and conversion circuits are integrated in an integrated circuit shaped like a triode, its temperature measurement range is 55°C to +125°C, and its accuracy is -10°C to +85°C ±0.5°C; the programmable resolution is 9 to 12 bits, and the corresponding resolvable temperatures are 0.5°C, 0.25°C, 0.125°C and 0.0625°C, so that high-precision temperature measurement can be realized, and at 9-bit resolution The temperature can be converted into numbers within 93.75ms at most, and the temperature value can be converted into numbers within 750ms at most at 12-bit resolution, that is, the response time is on the order of microseconds. When placing the sensors, in order to avoid the influence of the sensors on the temperature transfer of the sample as much as possible, the sensors are arranged in a staggered order from top to bottom. The interval between two adjacent sensors in the depth direction (z direction) is a constant value, and the corresponding The projection distance should be as large as possible. Because its size is about 3mm, to achieve a vertical spatial resolution of <3mm, there needs to be a certain overlap in the vertical direction, that is, similar to the structure .

The voltage and current acquisition circuit is shown in Figure 3. The black dots in the figure represent 6 metal sheets 2, that is, 6 test electrodes. The adjacent metal sheets 2 form a pair of test electrodes, and there are 5 pairs of test electrodes in total. The metal sheets 2 are connected to the power supply in parallel, and the voltage at both ends of each pair of metal sheets 2 is the same, which is measured by a voltmeter. The current flowing between each pair of metal sheets 2 can be converted from the data measured by the ammeter, that is . Then according to the formula Calculate the conductivity of the dielectric material between each pair of test electrodes.

During the measurement, multiple temperature measuring sensors measure at the same time, the temperature display circuit displays the temperature measured by the temperature sensor 8 in real time, and records the temperature value of the measured dielectric material 1 between each metal layer, and the temperature and conductivity change with time can be obtained curve. After reaching a steady state, the temperature and conductivity data distributed with depth in the measured dielectric material 1 are obtained.

The heat source 5 can also use a solar simulator. If a solar simulator is used, the range of temperature variation at different illumination inclinations can be investigated, and reliable data can be provided for the evaluation of the internal charge of the satellite's exposed medium.

Example 2

Fig. 4 has provided another kind of embodiment of the present utility model, and the difference of the measurement device of the body conductivity under the temperature gradient of the medium material temperature gradient of this star and embodiment 1 is that the metal sheet 2 on the metal layer of the measured dielectric material 1 The number is greater than 1, and the upper and lower adjacent metal sheets 2 have the same structure and corresponding positions. As shown in FIG. 4 , there are metal sheets 2 arranged in an array of 4×4 on each metal layer. The temperature sensor 8 is arranged in the measured dielectric material 1 on each metal sheet 2 . This embodiment is mainly aimed at the situation that the temperature is distributed three-dimensionally in the medium when the distribution of the heat source is not uniform or the boundary insulation condition is not symmetrical. That is, by arranging a plurality of metal sheets 2 on each layer, the three-dimensional distribution result of the temperature and electrical conductivity of the dielectric material is obtained. For other layouts that need to be denser, similar implementations can be made.

Claims (7)

1. a star measurement mechanism for bulk conductivity under dielectric material thermograde, is characterized in that comprising thermal source (5), temperature collecting device, electric current and voltage Acquisition Circuit and adopts multilayer circuit board machining process through-thickness to be arranged at least four layers of metal level in tested dielectric material; Every layer of metal level is at least provided with piece of metal sheet (2), sheet metal (2) structure of upper and lower double layer of metal interlayer is identical and position corresponding; A lead-in wire (7) is drawn at each sheet metal (2) edge, and described lead-in wire (7) is connected with electric current and voltage Acquisition Circuit, and adjacent two sheet metals (2) up and down form a pair test electrode; Described thermal source (5) is positioned at the top of tested dielectric material (1), irradiates tested dielectric material (1) upper surface at a certain angle; Described temperature collecting device comprises temperature sensor (8), temperature collection circuit, temperature display circuit, described temperature sensor (8) is placed in the middle dielectric layer of the test electrode that adjacent two sheet metals (2) are up and down formed, described temperature sensor (8) is connected with temperature collection circuit, and described temperature collection circuit is connected with temperature display circuit.

2. the measurement mechanism of bulk conductivity under star dielectric material thermograde according to claim 1, is characterized in that the surrounding of tested dielectric material is also coated with thermofin (3).

3. the measurement mechanism of bulk conductivity under star dielectric material thermograde according to claim 1, is characterized in that also being covered with cryosphere bottom tested dielectric material.

4. the measurement mechanism of bulk conductivity under star dielectric material thermograde according to claim 3, is characterized in that described cryosphere is dry ice layer (6).

5. the measurement mechanism of bulk conductivity under star dielectric material thermograde according to claim 1, is characterized in that described sheet metal (2) is copper sheet.

6. the measurement mechanism of bulk conductivity under star dielectric material thermograde according to claim 1, is characterized in that described thermal source (5) is for heat lamp battle array or solar simulator.

7. the measurement mechanism of bulk conductivity under star dielectric material thermograde according to claim 1, is characterized in that described tested dielectric material (1) is epoxy resin, a kind of or wherein a kind of modification medium material in polyimide or teflon.