The PCB-layout is critical for good performance. Therefore, special care should be taken to ensure good electrical and thermal properties. In the motor driver circuitry highly sensitive analog signals are close to high current motor and gate current tracks, so a good placement is essential. The TMC2209-LA has a tiny QFN28 package with 5 mm x 5 mm. Its exposed die attach pad ensures heat dissipation into the PCB. Therefore, a number of thermally conductive wires is required to ensure a thermal contact to a GND layer, spreading heat into the whole PCB. Take care to ensure solderability, a too high diameter of the wires will lead to solder being drawn away. Countercheck with the PCB manufacturer or assembly site for best selection.