An electronic device includes a printed circuit board (“PCB”) structure which accommodates a thermal interface material (“TIM”). The PCB structure includes a base plate, a first component on the base plate, a second component on the base plate and apart from the first component, an interposer connected to the base plate and surrounding the first component and the second component, a cover plate connected to the interposer and covering the first component and the second component, and an accommodation part which is between the base plate and a heat conduction plate and accommodates the TIM.