Identification of pin-open faults by capacitive coupling

摘要

Disclosed is a system that determines whether input and output pins of semiconductor components are present and properly soldered to a circuit assembly. The system includes an oscillator which is connected to a probe that is brought into contact with a circuit assembly wiring trace soldered to the pin being tested. A conductive electrode is placed on top of the component and connected to a capacitance measuring circuit. The oscillator signal is capacitively coupled through the integrated circuit package to the pin being tested, so if capacitance is measured by the capacitance measuring device, the pin is connected to the circuit assembly. An amplifier may be connected to the conductive electrode to amplify the signal, and a segmented probe may be used to isolate individual pins. The probe may be shielded, and unused pins may be grounded.