Single-layer boards are used in many commercial applications due to their low cost.
However, from an EMC point of view they are the most demanding boards to work with, as it is not possible to incorporate a ground layer on the board. This may increase the need for external components or shielding to achieve EMC compatibility, especially at high clock speeds. The layout of a single-layer board will require very good EMC design skills from the designer, as the layout very easily ends up having large loops that will act as antennas. It is always a good idea to use wires and straps to overcome some of the worst routing problems, but the task is still demanding.