The present invention provides a microelectronic device and circuit board thereof. The microelectronic device includes an accommodating housing, a circuit substrate, an electronic component, and a wire. The accommodating housing has an accommodating space therein. The circuit board is disposed in the accommodating space, and has a first end surface and a second end surface dispose at the opposite side. The first end surface is provided with a first conductive contact, and the side of the circuit board is provided with a receiving hole in the form of a half opening through the second end surface. And a second conductive contact is disposed on the surface of the receiving hole, and the second conductive contact is electrically connected to the first conductive contact through an internal planes of the circuit board. The electronic component is disposed on the first end surface and electrically connected to the first conductive contact. One end of the wire is disposed in the receiving hole and electrically connected to the second conductive contact. Thereby, the wires can be firmly connected to the circuit board in a limited space.本發明公開一種微型電子裝置及其電路基板。微型電子裝置包括容置殼體、電路基板、電子器件及導線。容置殼體內具有容置空間。電路基板設置於容置空間中，且具有對應設置的第一端面及第二端面，第一端面佈設有第一導電接點，電路基板的側邊開設有貫通第二端面的半開孔容置孔，且容置孔表面佈設有第二導電接點，第二導電接點通過電路基板的內部電源層與第一導電接點電性連接。電子器件設置於第一端面並與第一導電接點電性連接。導線的一端設置於容置孔中且與第二導電接點電性連接。藉此，能在有限的空間內使導線穩固地與電路基板相互連接。
