Enabling Heat Dissipation in 12 Layer Rigid-Flex PCBs with Heat Sinks

The continual design and manufacturing of complex, solution driven devices for many industrial applications has increased the importance of rigid-flex Printed Circuit Boards (PCBs). As the demands for improved electronics has increased, so has the demand for improved PCB performance. They need to be designed with multiple layers to work with complex electronic equipment, be compact and lightweight, and be able to resist environmental contaminants.

Overheating is a problem even with today’s PCBs, as excess heat can cause traces, chips, connectors, or solder joints to function improperly. In such cases, PCB manufacturers add heat sinks to the PCB design. How does the addition of this device help PCBs function properly? What are the benefits of heat sinks? Let’s find out.

What are Heat Sinks, and How do they Support PCBs?

Heat sinks are types of heat exchangers. They are designed to transfer the heat emanating from a device to a fluid medium. Generally, the medium is air, however, oil, coolants, and even water can be used as fluid medium. The use of the liquid medium allows the heat to dissipate from the device. In PCBs, heat sinks are used as the device itself does not have sufficient power to ensure heat dissipation, and temperature moderation. It also ensures uniform heat distribution.

The benefits of heat sinks include:

  • Excellent thermal conductivity
  • More surface area in connection to fluid medium
  • Supports continual PCB performance

How Heat Sinks Work

Rigid-flex PCBs comprise a combination of rigid copper and flexible layers. Heavy copper is used so as to increase the PCB’s current carrying capacity. However, the use of large ounces of copper can result in excess heat. This is where the heat sink comes in. The heat sink is installed in heat conductive, but electrically insulated mounting area. When a 12 layer rigid-flex PCB with heat sink is installed and used in an application, the heat generated is transferred to the heat sink by heavy copper plated vias. The heat sink transfer the heat to the fluid medium, which helps dissipate it from the PCB.

Most rigid-flex PCB are manufactured using for retardant and polymer materials for strength and flexibility. The combination of these materials allows 12 layer rigid-flex PCB with heat sink to maintain thermal stability, electrical insulation, and uniform electrical power distribution.