Heat Dissipation Principle of Ceramic PCB

Ceramic circuit boards find applications in areas such as LED cooling, sensors, high-power modules, etc. This is primarily due to the excellent heat dissipation and insulation capabilities of ceramic substrates. So, what is the heat dissipation principle of ceramic heat dissipation PCBs?

Taking LED as an example, the thermal bottleneck in many systems mainly occurs when transferring heat from the LED chip to its substrate and then to the system circuit board. Possible heat dissipation pathways for this part include: firstly, directly dissipating heat from the chip substrate to the system circuit board. In this heat dissipation pathway, the thermal dissipation capability of the LED chip substrate material is a crucial parameter. Secondly, the heat generated by the LED will also reach the system circuit board through the electrode metal wires. Generally, when using wire bonding for electrode connection, heat dissipation is limited by the relatively slender and long geometry of the metal wires. Therefore, there are recent methods such as eutectic or flip-chip bonding, which significantly reduce the length of the wires and greatly increase the cross-sectional area. This design effectively enhances the heat dissipation power from the LED electrode wires to the system circuit board.

Generally, LED chips are formed by connecting LED dies using methods such as wire bonding, eutectic bonding, or flip-chip bonding to their substrate, creating an LED chip. Subsequently, the LED chip is secured onto the system's circuit board. Therefore, potential heat dissipation pathways for LEDs include direct dissipation into the air or through the LED die substrate to the system circuit board and then into the atmospheric environment. The rate of heat dissipation from the system circuit board to the atmospheric environment depends on the overall design of the lighting fixture or system.

Traditional LED heat dissipation methods:

1. Dissipation into the air.

2. Heat is directly exported from the system circuit board.

3. Heat is exported through gold wires.

4. In the case of eutectic and flip-chip processes, heat is exported through vias to the system circuit board.

Ceramic circuit board exports heat from the LED die, primarily utilizing the superior heat conductivity of its heat dissipation substrate material. Ceramic substrates exhibit thermal conductivity that is 100 times greater than that of aluminum substrates and 10 times greater than that of copper substrates. Due to its excellent heat conduction properties, ceramic substrates effectively address the heat dissipation challenges of high-power LED products, promoting the development of the LED industry and its products. In addition to widespread use in the LED industry, ceramic substrates are also extensively applied in automotive controllers, sensors, and consumer electronics.