Circuit Designs for High Power Boards

When Designing High Power PCBs there are additional considerations that need to be taken in to account compared to when designing non-High Power PCB boards.

The following are some of the factors that require consideration:

The amount of airflow the board will be exposed to
The number of ICs on the board
The material that the board is constructed from
The overall size of the board
The thickness of the copper

Identifying Current Flow

It is important to consider where and how much current will be flowing in the board. Large ICs with large current requirements along with copper traces do account for a large portion of power loss and heat generation within boards. Typically, heatsinks and fans are good ways to cool a board down. However, for smaller boards, where using such methods would not be possible to implement, using thermal VIAs/thermal landings and increasing the thickness of the copper are possible solutions.

Using Heavier Copper

Using heavier copper can be a solution to reduce power usage on the board. Electrical connections which cover a larger area and are thicker have lower resistance which reduces the amount of power lost to heat. When using a larger amount of copper, the width of the copper traces will also have to be increased.

Using Thermal VIAs

The use of a thermal via is another possible design tool that helps combat an increased density of heat in high power-consuming components. A heat VIA is a conductor that runs from one side of the board to the other and can help in moving heat away from critical electronic components.

Thermal VIAs move away the heat from critical electronic components and on to a thermal landing. A thermal landing is a metal plate that is mounted onto a board (ideally on the bottom) and at a point on the board which is relatively far from the critical components and not a point of failure.