A heat dissipating device includes a semiconductor packaging structure having a stator set and a semiconductor element provided therein, a fan wheel set pivotally connected to the semiconductor packaging structure, and a guiding structure having a guiding channel. The guiding structure receives the semiconductor packaging structure and the fan wheel set. The fan wheel set includes a plurality of blades located above the surface of the semiconductor packaging structure. The stator set and the semiconductor element controls the first blades. The blades extend beyond side surfaces the semiconductor packaging structure and have their sizes increased, such that the airflow volume can be increased without changing the size of the semiconductor packaging structure.