Thermal Conductivity Testing in Electronics, Buildings, and New-Energy Materials

A thermal conductivity instrument measures the rate of heat transfer through materials and supports electronic thermal design, building-energy assessment, and new-energy materials research.

Electronics

For epoxy and silicone chip-packaging materials, the stated thermal-conductivity range is 0.5–5 W/(m·K). ASTM D5470 is cited for measuring through-thickness thermal resistance and assessing thermal contact resistance in thermal-interface materials. For GaN power amplifiers in 5G base stations, it specifies an aluminum-nitride substrate with λ ≥ 200 W/(m·K). A laser flash analyzer directly measures thermal diffusivity at 1,000 °C; thermal conductivity is derived using density and specific heat capacity. The resulting data can be entered into ANSYS simulations to optimize heat-sink thickness and fin spacing, with a target device operating temperature of no more than 85 °C.

Building energy efficiency

Buildings account for 30% of global energy consumption. GB/T 10294 (guarded hot plate method) and ISO 8301 are cited for testing the thermal conductivity of foam glass, rock wool, and similar insulation materials. An insulation classification runs from class A, λ ≤ 0.045 W/(m·K), to class C, λ > 0.065 W/(m·K). In one green-building example, comparison of 10 insulation materials led to selection of a vacuum insulation panel with λ = 0.038 W/(m·K), with a reported 25% reduction in heating energy use. Re-testing after accelerated aging is used to assess conductivity loss over the service period.

For phase-change materials, the instrument measures changes in λ near 23–26 °C. Graphite-doped PCM can increase λ from 0.2 to 0.8 W/(m·K). For aerogel composites, a density of 0.1 g/cm³ and a thermal conductivity of 0.015 W/(m·K) are given as a balance point.

New-energy materials

Using the transient plane source method, the stated thermal conductivity values are approximately 1.5 W/(m·K) for a graphite anode and 0.7 W/(m·K) for a lithium-iron-phosphate cathode. It also describes monitoring a battery separator whose λ decreases from 0.2 to 0.05 W/(m·K) at high temperature for early thermal-runaway warning models.

For photovoltaic materials, the stated values are approximately 0.15 W/(m·K) for EVA film and 1.0 W/(m·K) for glass, with a reported 0.5% increase in photovoltaic conversion efficiency from thermal-design optimization. For thermoelectric materials, laser-flash measurement of λ, together with a separately measured Seebeck coefficient, can be used to calculate ZT; one example decreases Bi₂Te₃ λ from 1.5 to 0.8 W/(m·K) and reports ZT changing from 0.8 to 1.2. A future temperature envelope is given as −196 to 1,500 °C.