Safety Under High Voltage: Analyzing Non-Linear Dielectric Strength and Breakdown in Thermal Gap Pads
In high-voltage electronic systems such as EV inverters and solar combiners, a thermal pad must serve as a reliable “electrical wall.” However, engineers often fall into the trap of assuming a linear relationship between dielectric strength and material thickness. This misunderstanding is a critical safety risk in high-power designs.
Chemical Principle: Electron Cloud Distribution and Breakdown Paths
The silicone matrix of Thermal Gels and Gap Pads is inherently insulating due to its chemical backbone:
Molecular Electron Tethering: The compact electron cloud of the Si-O backbone in PDMS provides a wide bandgap, effectively inhibiting free electron migration.
Non-linear Breakdown Characteristics: Breakdown voltage ($V_b$) does not increase linearly with thickness ($d$). As thickness increases, the probability of microscopic defects (air bubbles or impurities) rises, causing the dielectric strength (V/mil) to decrease. This necessitate sufficient safety margins in high-voltage designs.
Industrial Application: Insulation Strategies for Power Batteries
Lixing Composite Material enhances the safety of Thermal Silicone Gaskets through optimized manufacturing:
Precision Degassing: Utilizing ultrasonic and vacuum technology to remove micro-bubbles, eliminating potential arc paths and ensuring stable dielectric strength across large surface areas.
Puncture Reinforcement: For PCBs or enclosures with metallic burrs, we offer products reinforced with Silicone Cloth layers to prevent mechanical piercing, maintaining a breakdown voltage consistently above 4KV
