Heat sinks used to be the primary solution for PCB thermal management. However, today’s board designs produce considerable heat as a result of the highly complex circuits and components populating increasingly smaller boards. Now more than ever, greater design detail and special thermal management techniques must be applied to PCBs. Advanced heat sinks continue to be main players in the heat dissipation process, but the PCB designer must think well beyond the heat sink to effectively transfer PCB component heat to either sides of the board and to the ambient.
Check out the May/June issue of SMT Magazine for our article explaining why thermal management is so important these days. The article gives you an in-depth understanding of what a PCB designer needs to consider to effectively overcome thermal issues at the layout stage and produce an effective board design for assembly.
Meanwhile, here are some tips to follow to make sure your outsourced PCB project gets the utmost attention when it comes to thermal management. While there is a number of considerations an experienced PCB designer applies for thermal management, the key design steps essential for effectively dissipating heat are:
- Properly distributing analog circuitry throughout the board.
- Effectively using ground pour on the PCBís internal layers, as shown here (show picture).
- Strategically deploying thieving, when possible.
- Considering a metal core (MC) board, if applicable.
- Creating more solid planes for transfer of heat.
- Selecting the proper heat sinks and attachment process.
- Using thermally conductive grease when applicable.
As part of the design process, the PCB designer should place special emphasis on the interface between heat sink and associated component or to the board itself because it is critical for effective thermal transfer. Normally, thermally conductive aluminum filled epoxy is used for bonding the fins of the heat sink to the component or to the board. It’s important that the right kind of alloy or substrate is used for attaching those heat sinks.