Besides the selection of the most suitable contact materials the design and typeof attachment is critical for the reliability and electrical life of contactcomponents for electromechanical switching devices. The materials saving useof high cost precious metals and the most economic manufacturing method forcontact parts are most important factors.

There are two basic manufacturing solutions available: One can start with singlecontact parts such as contact rivets or tips which then are attachedmechanically or by brazing or welding resp. to carrier parts. In the second casea base material coated or clad with the precious contact metal - for specialapplications also clad with another non-precious material – in the form of stripsor profiles is manufactured as a semi-finished pre-material from which thecontact components are then stamped and formed. Besides mechanicalcladding other processes such as electroplating and deposition from the gasphase are utilized.Which of the following manufacturing processes is finally chosen depends onthe final application of the contact components in their respective switchingdevices or electromechanical components. Other considerations such as therequired number of electrical operations, the most economical use of preciousmetals and the anticipated volumes of parts are also important for the processselection.

The group of single contacts includes contact rivets, contact tips, and formedparts such as weld buttons. Contact spheres (or balls) are today rarely usedbecause of economical considerations. <br>

Semi-finished contact pre-materials can be manufactured from solid preciousmetals, precious metal alloys, or precious metal containing composite materials. <br>

The following segments give an overview of the usually applied attachmenttechnologies for contact parts to carrier components. They include mechanicalas well as brazing and welding methods used for electrical contact assemblies.

The switching properties of brazed and welded contact assemblies is stronglydependent on the quality of the joint between the contact and the carrier. Therequired high quality is evaluated through optical methods, continuous controlof relevant process parameters and by sampling of finished products.