As for all switching power supplies, especially those running at high switching frequency and high currents, layout is an important design step. If layout is not carefully done, the regulator could suffer from instability as well as noise problems. To maximize efficiency, switch rise and fall times are fast. To prevent radiation of high frequency noise (this is, EMI), proper layout of the high frequency switching path is essential.
Minimize the length and area of all traces connected to the SW pin and always use a ground plane under the switching regulator to minimize interplane coupling.
The high current path including the switch, Schottky diode, and output capacitor, contains nanosecond rise and fall times and should be kept as short as possible.
The input capacitor needs not only to be close to the VIN pin, but also to the GND pin in order to reduce the input supply ripple.