Application of the signal processing in the case of ultrasonic inspection of PCB components

Abstract

The improved detection and characterization of internal defects in printed circuit boards (PCB) has been investigated. The two different signal processing techniques have been used to increase the contrast of defective regions and in such a way to improve reliability of inspection. The experiments were carried out on a real PCB. The inspection was performed using the acoustic microscope produced by Ultrasonic Science Ltd. The examples of the internal defects measured by the scanning acoustic microscope are presented. The novel signal processing method based on the adaptive ultrasonic numerical model of the electronic device and appropriate selection in frequency domain has been proposed.