Backing plate and its manufacturing process

Abstract

A backing plate of Ti for supporting a Ti sputtering target is formed of at least two components welded together. The backing plate is welded by interposing a Cu or Zr foil or powder between faces to be welded, and then heating the assembly to a reaction temperature high enough to melt one of the Ti and Cu or Zr to produce a liquid phase. The heating temperature is retained for a time long enough to permit diffusion of the Cu or Zr into the Ti to produce a liquid phase diffusion weld. By permitting diffusion to occur, a separate metallic compound is not produced at the welding face. In effect welding is accomplished without producing a welding face, whereby no interface exists in the finished weld. The resulting weld has a strength substantially equal to the strength of the Ti material, and very good welding qualities.

1 . A process for joining at least two components of Ti material comprising: 
 interposing a Cu material on a welding face between said two components;    heating said two components and said Cu material to a welding temperature at which said Cu material is liquified;    maintaining said welding temperature for a sufficient time to permit a substantial diffusion of said Cu material into said two components; and    said substantial diffusion being sufficient to substantially remove liquid Cu material from said welding face by said diffusion of said Cu into said Ti material.    
     
     
         2 . A process according to  claim 1 , wherein said welding temperature is one of an eutectic reaction temperature or more of Ti—Cu alloy and a reaction temperature or more of an intermetallic compound formed by said Ti and Cu materials.  
     
     
         3 . A process according to  claim 1 , wherein said at least two components form a backing plate for a sputtering process.  
     
     
         4 . A process according to  claim 1 , further comprising performing the step of heating in an atmosphere of one of a vacuum, an inert gas, and a reducing gas.  
     
     
         5 . A process according to  claim 1 , wherein said Cu material is at least one of a Cu foil and a Cu powder.  
     
     
         6 . A process according to  claim 1 , wherein the step of heating includes heating to a temperature of from about 887° C. to about 1670° C.  
     
     
         7 . A process according to  claim 1 , wherein the step of maintaining includes maintaining said welding temperature for at least 600 seconds.  
     
     
         8 . A process for joining at least two components of Ti material comprising: 
 interposing a Zr material on a welding face between said two components;    heating said two components and said Zr material to a welding temperature at which said Zr material is liquified;    maintaining said welding temperature for a sufficient time to permit a substantial diffusion of said Zr material into said two components; and    said substantial diffusion being sufficient to substantially remove liquid Zr material from said welding face by said diffusion of said Zr into said Ti material.    
     
     
         9 . A process according to  claim 8 , wherein said welding temperature is one of an eutectic reaction temperature or more of Ti—Zr alloy and a reaction temperature of an intermetallic compound formed by said Ti and Zr materials.  
     
     
         10 . A process according to  claim 8 , wherein said at least two components form a backing plate for a sputtering process.  
     
     
         11 . A process according to  claim 8 , further comprising performing the step of heating in an atmosphere of one of a vacuum, an inert gas, and a reducing gas.  
     
     
         12 . A process according to  claim 8 , wherein said Zr material is at least one of a Zr foil and a Zr powder.  
     
     
         13 . A backing plate produced by the process of  claim 1 .  
     
     
         14 . A backing plate produced by the process of  claim 8 .  
     
     
         15 . A process according to  claim 5 , wherein said Cu foil comprising a thickness of about 18 μm to about 60 μm.  
     
     
         16 . A process according to  claim 5 , wherein said Cu foil comprising a thickness of about 18 μm to about 30 μm.  
     
     
         17 . A process according to  claim 5 , wherein said Cu powder comprising a particle size diameter of about 25 μm to about 30 μm.