A semiconductor package includes a wiring board, a semiconductor chip flip-chip bonded to the wiring board, an adhesive coated on the wiring board, a stiffener ring attached to the wiring board, and a heat spreader attached to the stiffener ring and the semiconductor chip. The stiffener ring includes a window through which the semiconductor chip is exposed and multiple through holes. A thermal interface material (TIM) coated on the back surface of the semiconductor chip. The stiffener ring is attached to the heat spreader by portions of the adhesive squeezed onto the upper surface of the stiffener ring via the through holes, and the semiconductor chip is attached to the heat spreader by the TIM. A method for manufacturing a semiconductor package includes: flip-chip bonding a semiconductor chip to a wiring board; coating an adhesive on the wiring board; and attaching a stiffener ring to the wiring board. The stiffener ring includes a window through which the semiconductor chip is exposed and through holes. The stiffener ring is attached to a heat spreader by portions of the adhesive squeezed onto the upper surface of the stiffener ring via the through holes, and the semiconductor chip is attached to the heat spreader by the TIM.