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: 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.

Abstract: A spinal expanding apparatus includes multiple supports extendable out of passages in a body and a bolt movably received in the body. The bolt has multiple grooves in an outer periphery of the bolt to correspond to bottom conical heads of the supports. Therefore, advancement of the bolt is able to force the supports to simultaneously extend out of the passages of the body. Each of the supports has a travelling distance the same as the others so that two adjacent spines are evenly separated.