High Thermal Conductivity Insulators Working Formula
As electronic devices become increasingly miniaturized, highly integrated and power dense, they can generate considerable amounts of heat. This heat must be dissipated efficiently to avoid overheating which can affect the performance and reliability of the device. Efficient Thermal Management in Electronics are a solution to this issue, by providing superior heat transfer properties that can be used to prevent overheating and extend the life of the device.
Thermal conductivity is the ability of a material to pass heat through it, which is determined by its temperature and pressure. It is also referred to as the l (lambda) value or a material’s “conductance” and measured in Watts per meter squared per Kelvin (W/m*K). Materials with high thermal conductivity easily transmit heat, whereas those with low conductivity resist the flow of heat and obtain it slowly from their surroundings.
Conductivity is a material property and varies over a wide range of temperatures, depending on the state of matter: liquids have lower conductivity than solids. In addition, the type of atoms or molecules within the material can have an effect on the conductivity of the material; for example, metals have high thermal conductivity due to the free movement of electrons within their molecular structures, while nonmetallic materials such as polymers or ceramics have much lower thermal conductivity.
The thermal conductivity of a material is related to the temperature of the material and the atomic or molecular structure. Unlike electrical conductivity, which is a scalar, thermal conductivity is a second-rank tensor and therefore must be described as such when used in engineering applications.
For a given material, its thermal conductivity can be calculated from the following formula: Thermodynamically, the tensorial form of the conductivity is equal to the product of the thermal conductivity and the temperature gradient across the surface of the material. This allows for a direct comparison of the thermal conductivity of different materials at any temperature, which can be useful in exploration and optimization.
In addition, the tensorial form of thermal conductivity allows for a better understanding of the relationship between a material’s temperature and its thermal conductivity when it is considered in an anisotropic material, such as an amorphous solid.
For example, an amorphous glass has lower thermal conductivity than a crystalline silicon or an alumina, because its crystal structure is more rigid and confined. As a result, an amorphous glass can have higher thermal conductivity at elevated temperatures than a crystalline silicon or an aramid.