TWI806319B - A Method for Quickly Evaluating Microwave Dielectric Loss - Google Patents

Abstract

The invention uses low dielectric insulation to protect the heat conduction properties of the ceramic carrier material, and conducts a method for quickly evaluating dielectric loss, so as to develop new materials with low dielectric insulation properties. Low-dielectric insulating materials can improve the problem of high-power component circuit signal interference, and at the same time have the effect of isolation strengthening protection, and the development of microwave ceramic substrate materials is expected to meet the current demand for 5G.

Description

A Quick Method for Evaluating Microwave Dielectric Loss

The present invention provides a method for evaluating microwave dielectric loss, especially a rapid evaluation method for obtaining microwave ceramic dielectric loss characteristics by measuring thermal diffusion, which can judge the relative characteristics of microwave between the same material system in a short time , which is of great help to verify the microwave dielectric loss characteristics of materials.

At present, with the rapid innovation of 3G, 4G, and 5G communication systems, the demand for new microwave materials in material design continues to increase. However, there is still a lack of a complete design basis for microwave materials, including crystalline ceramics or glass materials. However, there are quite a lot of research literature and materials accumulated so far. The biggest problem is that the development of the microwave property measurement system is far behind.

The application of microwave in communication plays a very important role. At present, the new development trend of microwave integrated circuits is to manufacture a high-speed and small-sized Multi-chip module. This Multi-chip module needs to find a low dielectric Loss (Dielectric loss, tanδ) and low dielectric constant (Dielectric constant) dielectric material (Dielectrics) as the substrate (Substrate). Substrate materials with low dielectric loss are also necessary for the new generation of microwave antennas and communication filters. the above New developments and the design of general microwave components require the use of different dielectric materials as the substrate of microwave circuit films or the basic materials of dielectric resonators. The choice of material is based on its dielectric properties. Therefore, the dielectric properties of dielectric materials at microwave frequencies are the key factors that must be considered in the selection of dielectric materials when designing microwave components. The measurement technology of microwave dielectric properties shows its importance in the selection of materials and the development of new materials. Therefore, research on the measurement technology of microwave dielectric properties is necessary.

The Parallel Plate Resonance Technique can measure the dielectric constant and dielectric loss at the same time, and has the function of frequency scanning (the frequency range of about 3GHz can be measured for the same sample) as its advantage, but it is limited by the radiation loss to the measurement Influenced by errors, the minimum measured value of dielectric loss cannot be lower than 1×10-5. As for TE Cavity PerturbationTechnique, its biggest advantage is that in all existing techniques, the required sample size is much smaller than other methods, a circular or rectangular columnar sample with a cross-sectional area of about 1mm2 is enough. It is very attractive for the measurement of some materials that are difficult to make large-scale samples, especially the single crystal grown in fiber shape shows its superiority. In addition, the measurement operation method is simple and the process of using the measurement results to calculate the dielectric properties is very simple, which is also the reason why it is quite popular, but the minimum measurement value of the dielectric loss cannot be lower than 1×10-5 .

In high-frequency and high-speed circuits, the electrical properties of materials are inseparable from the signal propagation speed, attenuation, and component size. Therefore, a method that can quickly measure microwave properties is needed, and at the same time, it can reduce labor, equipment and sample construction. cost. In addition, there are still a lot of microwave materials to be evaluated for communication frequency and other related equipment. In this huge workload, there is a considerable demand for the measurement of microwave properties. However, in many microwave measurement systems, the sample The requirements are quite stringent, and the measurement system is also very expensive, so a method for quickly screening microwave materials is extremely needed.

In order to solve the above problems, the present invention uses a group of low-dielectric insulation protection ceramic carrier materials to evaluate the relationship between microwave properties and thermal conductivity, so as to develop a rapid evaluation method for microwave ceramic dielectric loss characteristics, which can save In the past, it took time and cost to measure microwave dielectric loss characteristics. Low-dielectric insulating materials can improve the problem of high-power component circuit signal interference, and at the same time have the effect of isolation strengthening protection, and the development of microwave ceramic substrate materials is expected to meet the current demand for 5G. The following is a brief description of the case.

The present invention provides a method for evaluating microwave dielectric loss. In terms of material testing, microwave properties are also affected by point defects in crystallization, in addition to being affected by microstructure (especially porosity). The thermal diffusion of ceramics is also affected by point defects in the crystallization. Therefore, the rapid evaluation method of the dielectric loss characteristics of microwave ceramics can be obtained by measuring thermal diffusion, which can establish a shortcut in the selection and evaluation of microwave ceramic materials. .

The thermal diffusion measurement method usually adopts heat flow method (Heat Flow Method; HFM); hot wire method (Hot Wire Method; HWM); hot plate method (Hot Plate Method; HPM); heat flux meter method (Heat Flux Method; HFM ); Transient Plane Source (TPS); Laser Flash Method (LFM). The above methods can also quickly detect the thermal conductivity of ceramic materials.

According to the idea of the present invention, a method for quickly evaluating microwave dielectric loss is provided, the steps include: (A) measuring one thermal diffusion characteristic and one microwave characteristic of the same material system, and repeating the measurement for more than three times to obtain three data points Above; (B) this data obtains a mathematical relational expression with linear regression mode and is y=ax+b, wherein a and b are constants, x is the data of this thermal diffusion characteristic, and y is the data of this microwave characteristic; (C ) First measure the data of the thermal diffusion characteristics of an unknown dielectric loss sample; (D) Substituting the data of the thermal diffusion characteristics of the unknown dielectric loss sample into the mathematical relationship in step B, the unknown can be quickly obtained Data of microwave characteristics of dielectric loss samples.

The method for rapidly evaluating microwave dielectric loss in the above steps, wherein the mathematical relational expression is established by the thermal diffusion characteristic and the microwave characteristic, and includes more than three data points to obtain the mathematical relational expression.

The above steps are a method for quickly evaluating microwave dielectric loss, wherein the microwave characteristic is dielectric loss (Df).

The method for quickly evaluating microwave dielectric loss in the above steps, wherein the material system can be Ba-Nb-W-O system, Ba-Cu-Sr-Si-O system; BaO-MO-SiO2 (M=Mg, Zn, Co, Ni, Mn, Cu) system.

The present invention utilizes the thermal diffusion characteristic of the ceramic material and the microwave dielectric loss characteristic having the same mechanism to carry out rapid and convenient measurement of micro wave characteristic mode. Taking advantage of the linearly dependent mathematical relationship between thermal diffusion and dielectric loss of ceramic materials, the measurement of thermal diffusion is used to replace the measurement of microwave properties of dielectric loss, which can quickly screen microwave materials.

The above overview, the following detailed description and the accompanying drawings are all for further explaining the ways, means and effects of the present invention to achieve the intended purpose. Other purposes and advantages of the present invention will be described in the subsequent description and drawings.

S101-S104: Steps

1: Dielectric loss

2: Thermal diffusion value

3: Mathematical relation

The first figure is a flow chart of a method for evaluating microwave dielectric loss of the present invention; the second figure is a mathematical relationship diagram of an embodiment of the present invention; the third figure is a dielectric loss and thermal diffusion value of an embodiment of the present invention The experimental data.

The implementation of the present invention is described below through specific examples, and those skilled in the art can easily understand the advantages and effects of the present invention from the content disclosed in this specification. However, the implementation of this case cannot be limited by the following implementation cases.

Please refer to the first figure, which is a flow chart of a method for evaluating microwave dielectric loss of the present invention, and the second figure is a mathematical relationship diagram of an embodiment of the present invention, and the third figure is a dielectric diagram of an embodiment of the present invention The reality of loss and heat dissipation value The steps include: Step S101 To provide a method for evaluating microwave dielectric loss, first use the traditional thermal diffusion and dielectric loss measurement methods to measure the thermal diffusion of ceramic materials with the same material system but different proportions characteristics and a microwave characteristic, the experimental data measured are thermal diffusion value 2 and dielectric loss 1, and the measurement is repeated for more than three times, and more than three data points are obtained, please refer to the third figure; and the experimental data of dielectric loss 1 to establish a mathematical relationship diagram, the established mathematical relationship diagram is at least 3 measurement points, and a mathematical relationship 3 is obtained by linear regression as y=-0.0027x+0.0038, please refer to The second figure; step S103 measures the data of the thermal diffusion characteristics of an unknown dielectric loss sample; step S104 uses the mathematical relationship 3 to substitute the thermal diffusion characteristics (x) of the same material system into the mathematical relationship 3, then Obtain reliable dielectric loss value (y).

The material in this embodiment can be Ba-Nb-W-O system, Ba-Cu-Sr-Si-O system; BaO-MO-SiO2 (M=Mg, Zn, Co, Ni, Mn, Cu) system; microwave characteristics is the dielectric loss (Dielectric Loss; Df).

This method can avoid the need for multiple measurements of the microwave dielectric loss characteristics of the same material system. It only needs to measure at least three microwave dielectric loss characteristics and thermal diffusion characteristics, and can use the mathematical relationship and thermal diffusivity measurement data. Preliminary evaluation of the microwave characteristics of the dielectric loss of materials with different composition ratios, greatly reducing the cost of measurement.

The above-mentioned embodiments are only illustrative to illustrate the characteristics and functions of the present invention, and are not intended to limit the scope of the essential technical content of the present invention. anyone familiar with this Those skilled in the art can modify and change the above-mentioned embodiments without departing from the spirit and scope of the invention. Therefore, the scope of protection of the rights of the present invention should be listed in the scope of the patent application described later.

1: Dielectric loss

2: Thermal diffusion value

3: Mathematical relation

Claims (4)

A method for quickly evaluating microwave dielectric loss, the steps include: (A) measuring a thermal diffusion characteristic and a microwave characteristic of the same material system, and repeating the measurement for more than three times to obtain more than three data points; (B) measuring the The data is linearly regressed to obtain a mathematical relationship as y=ax+b, where a and b are constants, x is the data of the thermal diffusion characteristics, and y is the data of the microwave characteristics; (C) first measure an unknown medium The data of the thermal diffusion characteristics of the electric loss sample; (D) Substituting the data of the thermal diffusion characteristics of the unknown dielectric loss sample into the mathematical relationship in step B, the microwave characteristics of the unknown dielectric loss sample can be quickly obtained the data. The method for quickly evaluating microwave dielectric loss as described in item 1 of the scope of the patent application, wherein the mathematical relationship is established by the thermal diffusion characteristics and the microwave characteristics, and contains more than three data points, so as to obtain the mathematical relationship Relational. As the method for quickly evaluating microwave dielectric loss described in item 2 of the scope of the patent application, the microwave characteristic is dielectric loss (Dielectric Loss; Df). As the method for rapid evaluation of microwave dielectric loss described in item 1 of the scope of patent application, wherein, the material system can be Ba-Nb-W-O system, Ba-Cu-Sr-Si-O system; BaO-MO-SiO2( M=Mg, Zn, Co, Ni, Mn, Cu) system.

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