A printed circuit board assembly includes a printed circuit board, an electronic device, a holder and a heat-dissipation device. The printed circuit board includes a first through hole. The electronic device includes a first surface and a second surface opposite to each other, and a pin passing through the first through hole of the printed circuit board and inserted on the printed circuit board. The holder is secured to the printed circuit board and disposed between the printed circuit board and the electronic device. The holder includes a supporting surface sustaining the first surface of the electronic device, and an opening disposed on the supporting surface to receive the pin of electronic device passing therethrough. The holder is configured to provide an accommodation space between the supporting surface and the printed circuit board. The heat-dissipation device includes a heat-dissipation surface thermally coupled with the second surface of the electronic device.