Abstract: An electronic system includes a circuit board, a first conducting element, a second conducting element and at least one connecting element. In this case, the circuit board has at least one through hole and at least one grounding unit disposed around the through hole. The first conducting element is disposed on one side of the circuit board, and the second conducting element is disposed on the other side of the circuit board. The connecting element is disposed through the through hole for connecting the first conducting element and the second conducting element.

Abstract: An electronic system includes a circuit board, a first conducting element, a second conducting element and at least one connecting element. In this case, the circuit board has at least one through hole and at least one grounding unit disposed around the through hole. The first conducting element is disposed on one side of the circuit board, and the second conducting element is disposed on the other side of the circuit board. The connecting element is disposed through the through hole for connecting the first conducting element and the second conducting element.

Abstract: An electronic device includes a first metal case, a second metal case, an electronic unit, a first heat insulation layer and a second heat insulation layer. In this case, the first metal case has a plurality of first holes, and the second metal case has a plurality of second holes. The first metal case is assembled with the second metal case to form an accommodating space. The electronic unit is disposed in the accommodating space. At least one surface of the first metal case is coated with the first heat insulation layer, and at least one surface of the second metal case is coated with the second heat insulation layer.

Abstract: A fixing component of a main board comprises a connecting part, a thread-assembling part and a fixing part. The connecting part has a first surface and a second surface, wherein the first surface is disposed opposite to the second surface. The thread-assembling part is disposed on the first surface of the connecting part. The fixing part is disposed on the second surface. The connecting part and the fixing part are disposed on a main board by utilizing DIP technology and SMT.

Abstract: An expandable heat sink is used for dissipating heat of a heat source on a main board. The heat sink comprises a main body and an expanded body. The main body comprises a main-body contact surface, which is contacted with the heat source, and a plurality of first fins. The first fins compose a main connecting portion. Furthermore, the expanded body comprises a plurality of second fins and the second fins compose an expanded connecting portion. The expanded connecting portion is removably connected to the main connecting portion.