Deep Etching
Gallery
During deep etching of Sn-based leadfree solder alloys: the Sn-matrix is dissolved while most of the intermetallic compounds are remaining.

Near-eutectic SnAgCu-alloy
The Sn-matrix has been dissolved, while the rod-shaped intermetiallic compounds of the eutectic microstructure remain.

Micro-alloyed leadfree solder material
The nuclei of the primary Ag3Sn-phase reveal their typical shape.

Primary phases of a leadfree solder joint
Primary (pre-eutectic) Cu6Sn5-phases solidified in hexagonal shape, larger crystals are often hollow.