Soldering a head slider to a tongue surface can be achieved by using gold ball bonding
(GBB) or solder ball bonding
In recent years, K/S has expanded its product offerings through strategic acquisitions and organic development, adding advanced packaging, advanced SMT, wedge bonding and a broader range of expendable tools to its core ball bonding
Abstract: Copper ball bonding
faces more challenges than gold ball bonding
, for example, excessive deformation of the bond pad and damage of Cu/ low-k structures, because of the much greater hardness of copper free air balls.
Rodrigues, "Simulation of Ball Bonding
on Various Bond Pad Structures", Proceedings of IEEE 14th Electronics Packaging Technology Conference, EPTC 2013, Singapore, Dec.
There were work done [6 & 7] on gold ball bonding
adhesion is influenced by both ultrasonic force and time of the process, the studies were done on aluminium bond pad, surface roughness effect were not discussed except on the native oxide formation on the bonding surface.
Chen, "A re-examination of the mechanism of thermosonic copper ball bonding
on aluminium metallization pads," Scripta Materialia, vol.
Wedge bonding can achieve finer pad pitch geometries than ball bonding
with the same wire diameter because of the smaller amount of bond "squash" or wire deformation.
The consumer market demand for smaller and more complex electronic devices is driving the wire bonding industry to set new ball bonding
Processes include high accuracy component assembly with eutectic solder or epoxy, precision ball bonding
, and wedge bonding for fine pitch devices, as well as epoxy, laser weld and solder based attachment of actively aligned photonic devices.
Figure 6 shows a relationship for impact force and static bond force with bond pad cratering for thermosonic ball bonding
.  Low bond pad impact force is generally used when round wire wedge bonding delicate ICs such as GaAs, but this process decreases bonding speeds dramatically.
Gold is the most widely used metal for IC wire bonding because of its resistance to surface corrosion and high productivity through the gold ball bonding
Gold is used because it is normally inert, well suited to the ball bonding
process and demonstrates excellent loop formation and cycle performance.