An electronic component on its way to being installed in a system has, it is hoped, no cracks, voids or other internal structural defects that may cause an electrical failure in service. Generally, internal structural anomalies are visible to ultrasound, and a trusted method for identifying components likely to fail is acoustic micro imaging—a tool that uses high-frequency ultrasound for imaging. Laboratory versions of these tools typically examine small numbers of components, but high-throughput automated systems can handle thousands of components, usually carried in trays.
The high-throughput imaging may be performed by the maker of the component, or by the user of the component. In both cases the detailed imaging parameters for trays of a given component are well established and succeed in removing those components that do not meet the manufacturer’s acceptance criteria and that are likely to fail in service.