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→Wire Bonding
Wire bonding is the manufacturing process for creating metallurgical bond connections between a thin wire (12.5 – 50 µm for gold fine-wires and 150 – 500 µm for aluminum thick-wires) and a suitably coated circuit carrier through friction welding. In principle this process consists of pressure welding with the aid of ultrasound. The metallurgical bond is mainly caused by frictional heat created through the relative movement between the two bonding partner materials. To achieve high reliability over longer time and under difficult environmental conditions high quality requirements regarding material and mechanical strength properties must be met by the surfaces of the bonding partners.
Multiple silicon chips are combined to a functional unit on a circuit carrier (for example PCB board, DCB substrate, thick film ceramic) which is mostly encased in a hybrid housing for environmental protection. The metallic conductors mounted inside the housing then serve as connections to the outside. If higher current carrying capacity is needed, as for example in power electronics, Al thick-wire bonding is employed ''<xr id="fig:Bond connection Al thick wire on clad AlSi"/> (Fig. 9.1)''.<figure id="fig:Bond connection Al thick wire on clad AlSi">2 bilder Fig[[File:Bond connection Al thick wire on clad AlSi. 9.1: jpg|right|thumb|Bond connection: Al thick-wire on clad AlSi; (a) Macro photograph,b) micro structure with ruptured wire.]]</figure>
== AlSi Clad Strip for Bond Connections==