Die Surface Delaminations

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.

Die Surface Delaminations

TQFP Die Surface Delaminations - Application Note 2566

Die Surface Delaminations

Sample & Method

The THRU-Scan imaging mode, developed by Sonoscan, uses the ultrasonic transducer above the sample to transmit ultrasound through the whole thickness of the sample. Exiting signals are detected by a sensor located below the sample.

Result

The advantage of THRU-Scan is that it can quickly determine whether a defect exists at any depth within the sample. In this case, the THRU-Scan image revealed three dark features whose boundaries were limited by the die or die paddle. This suggested delaminations at the die attach level, die face and/or the back side paddle. Gating a planar C-SAM image at the die surface level (top image) showed that the delaminations are between the die surface and the mold compound.