SUBSTRATE WITH PROTECTION FUNCTION, ELECTRONIC DEVICE, AND ELECTRONIC CIRCUIT BOARD

To enable good protection against high voltage pulses and further miniaturization or high-density mounting of a circuit board on which an electronic device is mounted.SOLUTION: A substrate with a protective function includes a plate-shaped ceramic substrate having a first main surface and a second main surface, a varistor layer included in the ceramic substrate, a dielectric contained in the varistor layer and a plurality of internal electrodes partially facing each other with the dielectric interposed therebetween, a pair of external electrodes on the first main surface, and a connection electrode electrically connecting the external electrode and the internal electrode. The connection electrode extends in the thickness direction of the ceramic substrate, and does not reach the second main surface, and an interval b between the internal electrodes is narrower than an interval a between the external electrodes.SELECTED DRAWING: Figure 2 【課題】高電圧パルスに対する良好な保護及び電子機器を実装する回路基板のさらなる小型化または高密度実装を可能とする。【解決手段】第１の主面及び第２の主面を有する板状のセラミック基体と、前記セラミック基体に含まれるバリスタ層と、前記バリスタ層に含まれる誘電体及び前記誘電体を挟んで一部が対向する複数の内部電極と、前記第１の主面上の一対の外部電極と、前記外部電極と前記内部電極とを電気的に接続する接続電極とを備え、前記接続電極は、前記セラミック基体の厚み方向に延在し、且つ、前記第２の主面に到達しておらず、前記内部電極間の間隔ｂが、前記外部電極間の間隔ａよりも狭い保護機能付き基体。【選択図】図２