Fusion Scanning Acoustic

The Sonix Fusion is a scanning acoustic microscope used for metrology and inspection.^[1][2][3]

The Sonix Fusion operates on the principle of acoustic microscopy, employing a transducer that emits focused ultrasonic pulses into the sample. The acoustic waves travel through the material and are partially reflected at boundaries where the acoustic impedance changes, such as at voids, cracks, delaminations, or material interfaces. The reflected signals are captured by the same transducer, and the time-of-flight and amplitude of the echoes are measured to construct a two-dimensional or three-dimensional image of the interior structure.

The instrument typically scans the transducer over the sample in a raster pattern, collecting data at each point to form an acoustic micrograph. The resulting image contrast reflects variations in material density and bonding quality, enabling the identification of defects not visible to optical microscopes or X-ray inspection.

In semiconductor manufacturing and packaging, the Sonix Fusion is used as a metrology and inspection tool after key assembly steps, such as die attach, wire bonding, molding, and encapsulation. The scanning acoustic microscope detects internal defects that can compromise reliability, including delaminations between layers, cracks in the die or substrate, and voids in underfill or molding compound.

The Sonix Fusion is applied in quality control and failure analysis of semiconductor packages, power modules, and microelectromechanical systems (MEMS). Common applications include detecting delaminations in plastic encapsulated packages, voids in solder joints or thermal interfaces, cracks in silicon dies, and disbonding in hybrid circuits.

Beyond microelectronics, the instrument can inspect composite materials, bonded interfaces, and ceramic or metal parts where internal discontinuities affect performance. The non-destructive nature of acoustic microscopy allows examination of finished components without altering or damaging them.