From the need to "Tiny Cooling Fan" thermal point of view, the printed version of the best upright installation, the distance between the board and the board should not normally be less than 2cm, and the arrangement of components on the printed version should follow certain rules : For free-convection air cooling equipment, the best is the integrated circuit (or other devices) are arranged in a longitudinal way, for "Tiny Cooling Fan" with forced air cooling equipment, the best is the integrated circuit by horizontal long way arrangement. Devices on the same piece of PCB should arrange their possible partition size and cooling degree heat, heat a small or poor heat resistance of the device in the most upstream cooling airflow, "Tiny Cooling Fan" heat capacity or heat good devices on the most downstream cooling airflow.