In an embodiment, a package includes an encapsulant laterally surrounding a first integrated circuit device and a second integrated circuit device, wherein the first integrated circuit device includes a die and a heat dissipation structure over the die; a sealant disposed over the heat dissipation structure; an adhesive disposed over the second integrated circuit device; and a lid disposed over the sealant and the adhesive, wherein the lid includes a first cooling passage and a second cooling passage, the first cooling passage including an opening at a bottom of the lid and aligned to the heat dissipation structure, the second cooling passage including channels aligned to the second integrated circuit device and being distant from the bottom of the lid.