Printed Circuit Board

Pictured

Time Domain Imaging (TDI)™
Utilizes an echo (amplitude & polarity) arrival ‘time’ as a reference, such as standard A-Scan, B-Scan and C-Mode type images.

Printed Circuit Board

PCB Internal Layers - Application Note 2479

Printed Circuit Board

Sample & Method

This board was imaged acoustically with C-SAM using the interface scan imaging technique as a demonstration of the information that can be gained from the interior of the board.

Result

The top image is simply an acoustic scan of the surface of the board. The three subsequent images each show acoustic features at the next deeper interface within the board. There are no defects in this board.

Acoustic imaging of printed circuit boards is sometimes required in order to determine whether the interior of the board has been damaged. The higher reflow temperatures required for Pb-free solders may make this type of inspection more common.