Abstract: A heat sink includes a base and a removable air guide member. The base includes a thermal plate and two air guide plates fixed to opposite two sides of the thermal plate. An air guide channel is formed between the thermal plate and the two air guide plates. The fins are connected to the thermal plate. One end of each air guide plate bends and extends to form a windshield while another end has a connection portion. The removable air guide member is detachably connected to the base. The removable air guide member includes two vertical plates. One end of each vertical plate is connected to the connection portion while another end bends outward and extends to form a horizontal plate. Thereby, the cooling module and the heat sink can be installed on a motherboard with electronic components arranged densely and may receive maximum airflow.