Description:
<jats:p>In this study, we have investigated a texture and microstructure of gold bonding wire by
transmission electron microscope, X-ray diffraction and electron back scatter diffraction according to
process parameters, such as casting, drawing and annealing processes. The gold was cast into 7mm
diameter rods by vertical continuous casting technique, the cast rods were drawn to a final wire size of
25μm, and then the fine wires were annealed. A unidirectional solidification structure having <100>
fiber texture of cast rod was strongly developed depending on casting route and speed. In the sample
with unidirectional microstructure developed in partial it is found that dislocation substructure with
nano-size appeared to display a characteristic feature, while no dislocation substructure is seen in the
sample with complete unidirectional microstructure. Interface stability between solid and liquid may
be responsible for this difference in dislocation substructure. With decreasing casting speed <100>
fiber component became weak. Initial texture plays important role on development of <111> fiber
texture at drawing and final annealing stages. On the basis of results obtained it is suggested that both
the initial texture are important in controlling the texture of gold bonding wire.</jats:p>