What is the application of thermal conductive silicone sheet in PTC heating element?

PTC (Positive Temperature Coefficient) heating element, as an automatic temperature control component, is widely used in various fields such as household appliances, medical equipment, automotive electronics, and industrial heating. Its characteristic is that the resistance increases rapidly with temperature, effectively controlling the heating temperature and achieving automatic constant temperature. In the design and use of PTC heating plates, thermal conductive silicon film plays an indispensable role as a key auxiliary material.

1. Basic Overview of Thermal Conductive Silicone Film

Thermal conductive silicone sheet is a flexible thermal conductive material composed of a silicone matrix and a thermal conductive filler. It has good thermal conductivity, high temperature resistance, and electrical insulation, as well as excellent flexibility and compressibility. These characteristics enable the thermal conductive silicone sheet to ensure effective heat conduction in harsh working environments and reduce the damage of thermal stress to electronic components.

2. The principle and structure of PTC heating element

PTC heating element is a heating element that utilizes the positive temperature coefficient characteristic of the material (i.e., the resistance increases with temperature) to achieve self-regulation. Its typical structure includes PTC material, metal electrode, and insulation layer. After being powered on, the resistance of PTC material will increase with the rise of temperature, thereby limiting the current and achieving self temperature limiting effect. PTC heating elements are widely used in equipment such as warm air heaters, heating seat cushions, and industrial heaters due to their self-adjusting function, which has the characteristics of high safety and high efficiency.

3. The key role of thermal conductive silicone sheet in PTC heating element

(1) Thermal conduction and heat dissipation management

In PTC heating plates, due to the large amount of heat generated by PTC materials during operation, this heat needs to be quickly and effectively dissipated to avoid local overheating. Thermal conductive silicone film, as an intermediate medium, can fill the tiny gaps between PTC heating elements and heat sinks or shells, ensuring that heat is quickly conducted from PTC materials to the heat sinks, thereby improving overall heat dissipation efficiency. This efficient thermal management not only extends the service life of PTC heating elements, but also improves the operational stability of the equipment.

(2) Electrical insulation protection

In addition to thermal conductivity, thermal conductive silicone sheets also have good electrical insulation properties. This characteristic is particularly important in the application of PTC heating elements. Due to the energized operation of PTC materials, if the thermal conductive medium does not have electrical insulation capability, it may cause short circuits or other electrical safety issues. The electrical insulation properties of thermal conductive silicone film can effectively prevent this risk and ensure the electrical safety of the system.

(3) Shock absorption and stress relief

During operation, PTC heating elements may generate certain mechanical stresses due to thermal expansion and contraction. Thermal conductive silicone sheets have good flexibility and compressibility, which can effectively cushion these stresses and reduce mechanical damage between components. In addition, the thermal conductive silicone sheet can also absorb vibrations to a certain extent, further improving the reliability of the PTC heating element system.