Patent ID: 9476934
Filing Date: 2016-10-25
CPC Classification: G01R

Claim Text:
1. An inspection apparatus for inspecting a wiring board that includes multiple layers of wiring including electrically connecting wirings of a plurality of mutually-different layers, from an uppermost layer to a lowermost layer, and at least one ground wiring electrically insulated from the multiple layers of wiring and located at a position, wherein distance between one ground wiring and a wiring of the uppermost layer of the multiple layers of wiring is longer than distance between the one ground wiring and another wiring, with the exception of the wiring of the uppermost layer of the multiple layers of wiring, the inspection apparatus comprising: an opposing electrode locatable facing a surface of the wiring board closest to the wiring of the uppermost layer; a capacitance meter that is electrically connected to the opposing electrode and the multiple layers of wiring and measures capacitance between the opposing electrode and the multiple layers of wiring; a ground; a switch box that is connected to the at least one ground wiring, the opposing electrode, and the ground, and switching between a first connection state and a second connection state, wherein a control unit extracting a capacitance value by calculating difference between a first capacitance that is measured in the first connection state by the capacitance meter, and a second capacitance that is measured in the second connection state by the capacitance meter, wherein capacitance in units of layers of the multiple layers of wiring is obtained based on the capacitance value extracted by the control unit.