A circuit board structure manufacturing method includes the following steps. A circuit substrate is provided including an insulating layer, a first metal layer, and a second metal layer. The insulating layer is disposed between the first metal layer and the second metal layer. The first metal layer has a first cavity. The insulating layer has a second cavity and a provisional region. A width of the first cavity is larger than a width of the second cavity. The provisional region is defined between a sidewall of the first metal layer defining the first cavity and another sidewall of the first metal layer defining the second cavity. A first masking layer is formed to cover the first metal layer and provisional region. The second cavity is exposed from the first masking layer. A heat-dissipating metal member is formed in the second cavity. Furthermore, the first masking layer is removed.