Epoxy Resin vs. Silicone: The "Temperature Resistance" and "Material Properties" Clash of Thermal Conductive Encapsulation Gels

In high-power electronic devices such as new energy vehicles, 5G base stations, and industrial power supplies, heat dissipation and temperature resistance directly determine the lifespan and reliability of the products. As the two major mainstream thermal conductive encapsulation materials, epoxy resin and silicone have significantly different performances in adverse temperature environments. This article explores the truth of this "cold and fire" confrontation from three aspects: temperature resistance, material characteristics, and application scenarios.

1. Thermal Resistance:
Epoxy resin: High temperature hard core, low temperature prone to cracking
The operating temperature range of epoxy resin potting compound is typically from -45℃ to 180℃. Its key advantage lies in its stability in high-temperature environments: after curing, it forms a three-dimensional network structure with a high degree of cross-linking, which can withstand high temperatures without deforming. It is suitable for outdoor lighting fixtures, car ignition devices, and other high-temperature applications.
Critical Weakness: Poor resistance to thermal shock. During rapid temperature cycling from -45℃ to 130℃, epoxy resin is prone to developing microcracks due to the accumulation of thermal stress, resulting in a decline in moisture-proof performance.
Organosilicon: Wide temperature range elastomer, resistant to both cold and heat
The application range of organic silicon thermal conductive potting compound is from -45℃ to 200℃. The silicon-oxygen backbone of the compound endows the material with a very low glass transition temperature, allowing it to remain elastic at low temperatures and absorb the stress caused by thermal expansion and contraction.
Additional value: The hydrophobic silicon-oxygen structure of organosilicon enables it to have inherent moisture-proof properties. The insulation resistance attenuation rate in a humid environment is only 1/3 of that of epoxy resin.

2. Material Characteristics:
The thermal conductivity of epoxy resin potting compound ranges from 1.2 to 4.5 W/m·K. It has excellent operability, adhesion performance, low shrinkage rate, low viscosity, easy gas emission, good solvent resistance, waterproof property, a long working time, and excellent thermal shock resistance.
Organic silicon thermal insulating and sealing adhesive has a thermal conductivity ranging from 0.6 to 3.5 W/m·K. It boasts excellent insulation properties, and its core advantage lies in: rapid heat conduction: The spherical boron nitride filler forms a three-dimensional heat conduction network, and the heat transfer path is 30% shorter than that of epoxy resin; the wet curing or vacuum defoaming process can eliminate over 99% of bubbles, avoiding hot resistance hotspots; after curing, it forms an elastomer with Shore A hardness ranging from 15 to 65, which can absorb mechanical vibrations and prevent components from being damaged due to thermal stress.

3. Application Scenarios:
Epoxy resin potting compound: Applicable scenarios: Ambient temperature environment, high mechanical strength requirements, and those that do not require frequent maintenance, such as automotive ignition devices, sensors, and ring-type transformers.
Organic Silicon Thermal Insulation and Sealing Adhesive: Applicable scenarios: High-temperature and high-humidity environments, high-frequency vibration, and complex electronic systems requiring rapid heat dissipation, such as battery packs of new energy vehicles, 5G base station power amplifiers, and photovoltaic inverters.