Contact switch coating

Abstract

Switch assemblies and switching methods are disclosed. In some embodiments, a switch assembly may include a first blade having a first contact within an enclosed cavity, and a second blade having a second contact within the enclosed cavity. The first and second contacts are operable to make or break contact with one another in response to a magnetic field. The switch assembly may further include a coating formed over each of the first and second contacts, the coating including a titanium layer, a second layer formed over the titanium layer, and a tungsten-copper layer formed over the second layer. In some embodiments, the second layer is copper or molybdenum.

What is claimed is: 
     
         1 . A switching method, comprising:
 providing a first contact operable with a second contact, wherein the first and second contacts form an open circuit in a first configuration and form a closed circuit in a second configuration;   providing a coating over each of the first and second contacts, the coating comprising:
 a base conductive layer; 
 a second conductive layer formed over the base conductive layer; and 
 a tungsten-copper layer formed over the second conductive layer; and 
   biasing the first contact and the second contact relative to one another using a magnetic field.   
     
     
         2 . The switching method of  claim 1 , wherein providing the coating over each of the first and second contacts comprises:
 sputtering the base conductive layer over the first and second contacts;   sputtering the second conductive layer over the base conductive layer; and sputtering the tungsten-copper layer over the second conductive layer.   
     
     
         3 . The switching method of  claim 2 , wherein sputtering the second conductive layer comprises sputtering a copper layer over the base conductive layer. 
     
     
         4 . The switching method of  claim 2 , wherein sputtering the second conductive layer comprises sputtering a molybdenum layer over the base conductive layer. 
     
     
         5 . The switching method of  claim 1 , further comprising providing a magnet proximate the first and second contacts. 
     
     
         6 . The switching method of  claim 5 , further comprising causing the first and second contacts to change between the first configuration and the second configuration in response to movement of the magnet. 
     
     
         7 . The switching method of  claim 5 , wherein the tungsten-copper layer of the first contact is operable to make contact with the tungsten-copper layer of the second contact in response to movement of the magnet. 
     
     
         8 . The switching method of  claim 1 , further comprising providing an indication of the open circuit or the closed circuit.