New Energy Vehicle Electric Heater Technology Comparison: Thick Film, Thin Film, and PTC
In the thermal management system of new energy vehicles (such as battery preheating, cabin heating, etc.), electric heaters are core components. The current mainstream technologies include thick film electric heaters, thin film electric heaters and PTC (positive temperature coefficient) electric heaters, which have significant differences in materials, structures, performance and applicable scenarios.
1. Thick film electric heater
(1) Principle and structure:
The resistor paste (containing metal oxides such as silver and palladium) is sintered on a ceramic or metal substrate through screen printing technology to form a micron-level thick film circuit, which generates heat when powered on.
(2) Features:
High efficiency and energy saving: thermal conversion efficiency > 95%, fast heating rate (up to 200°C/s).
Temperature uniformity: The thick film resistor is evenly distributed to avoid local overheating.
Strong weather resistance: The ceramic substrate is corrosion-resistant and shock-resistant, and can withstand temperatures ranging from -40 °C to 300 °C.
Customized design: It can flexibly adapt to different power requirements by adjusting the paste composition and printing pattern.
(3) Application scenarios:
Fields with high requirements for response speed and reliability, such as low-temperature preheating of power batteries and motor heating.
2. Thin film electric heater
(1) Principle and structure:
Vacuum coating (such as magnetron sputtering) is used to deposit a nano-scale metal (nickel-chromium alloy, etc.) resistor layer on an insulating substrate (polyimide, stainless steel), with a thickness usually less than 1μm.
(2) Features:
Light, thin, and flexible: can be bent to fit complex curved surfaces, and the weight is more than 30% lower than that of thick films.
Precise temperature control: The temperature coefficient of resistance (TCR) is stable, suitable for precise temperature control (±1°C).
Low thermal inertia: fast heating/cooling speed, but low power density (usually less than 5W/cm²).
High cost: The vacuum process is complex, and mass production is difficult.
(3) Application scenarios:
Scenarios that require lightweight and flexible integration, such as in-vehicle seat heating and steering wheel heating.
3. PTC electric heater
(1) Principle and structure:
Use the positive temperature coefficient effect of ceramic materials such as barium titanate: low resistance and high heat generation at low temperatures; when the temperature rises, the resistance increases sharply, achieving self-limiting temperature (usually limited to 150°C).
(2) Features:
Self-regulating and safe: no additional temperature control circuit is required, and the power is automatically reduced when overheating.
High stability: long life (>100,000 cycles), resistant to voltage fluctuations.
Low energy efficiency: thermal conversion efficiency is about 70%~80%, and energy consumption is high during cold start.
Large volume: requires a heat dissipation structure, which takes up a lot of space.
(3) Application scenarios:
Traditional warm air air conditioners, charging pile antifreez, and other scenarios with high safety requirements and moderate power requirements.
