Ball Bonding vs Wedge Bonding

For many years, wire bonding has been the most robust and commonly used method for chip-to-die interconnection of lead-frame, integrated circuit (IC) packages, RF microwave packages and optoelectronic packages.

A question often gets asked concerning what kind of application we use: ball bond or wedge bond? Why would a process engineer choose a wedge bonder over a ball bonder or vice versa? This has been the question by most process engineers because, generally speaking, electrical characteristics of the package are affected by the method of wire bonding.  However, there are cases where certain packages have physical constraints such as temperature limitation (low heat or no heat applications), use of aluminum wire instead of gold, use of ribbon instead of wire and fine pitch application. This is where the proper selection of wire bond process comes into play.

orms the wire into a flat elongated shape of a wedge, however depending on the type of wedge tool used, the shape can sometimes have a cross groove (typically for 1 mil gold wire). Unlike ball bonding, the first bond for a wedge bond does not have a ball, which is why this wire bonding process is called wedge-wedge bonding.

lude high-power applications, RF microwave, optoelectronic packaging, BGA, QFP, SOP, MCM hybrids and temperature-sensitive applications. Wedge bonding speeds typically fall within 3-6 wires per second, comparatively slower than a ball bonder.