Embedded eddy current inspection apparatus, system, and method

摘要

An embedded eddy current inspection apparatus includes a substrate having an opening, and a test eddy current coil ("test coil") affixed to the substrate near the opening. An internally inspected multilayer component structure includes an upper layer, a lower layer, and an eddy current probe embedded between the upper and lower layers. The eddy current probe includes the test coil facing a subject layer selected from the upper and lower layers. A method of inspecting a multilayer component structure includes simultaneously energizing the test coil and a reference eddy current coil ("reference coil") embedded between the upper and lower layers and facing the subject layer. The reference coil is located in a reference region of the multilayer structure. A test signal from the test coil is compared with a reference signal from the reference coil, to determine whether a flaw is present in the subject layer near the test coil.