Ex Parte Murofushi et al - Page 10



             Appeal No. 2007-1530                                                                                      
             Application 10/095,112                                                                                    

                    While attempting to produce a substrate that is lower in weight, higher                            
                    in electrical conductivity, tougher and harder than its aluminum                                   
                    predecessors, the Al—B—C ceramic is excellent.  Its density is lower                               
                    than the others, its electrical conductivity nearly rivals pure metallic                           
                    aluminum, its stiffness is excellent, its fracture toughness is very                               
                    good, and its hardness is more than satisfactory.  As one can see, all                             
                    the properties needed for a substrate are easily met or exceeded by the                            
                    Al—B—C composite material.                                                                         
             (Col. 8, ll. 22-29.)  Thus, the electrical conductivity of the Al—B—C ceramic is                          
             described as “nearly rival[ling] pure metallic aluminum” (id.) even though                                
             aluminum’s conductivity exceeds that of the Al—B—C ceramic by more than an                                
             order of magnitude.  High electrical conductivity and low density are also among                          
             the properties mentioned in the following summary of the properties of Pyzik’s                            
             composites:                                                                                               
                           Accordingly, the present invention provides hard drive disk                                 
                    substrates, methods of making same, and materials made therefrom,                                  
                    wherein the material has a high hardness, a high wear resistance, a                                
                    high fracture toughness, a high damping capability, a low density, and                             
                    a high specific stiffness and is electrically conductive.  In addition, the                        
                    material forming the disk substrates exhibits unique combinations of                               
                    properties, such as high stiffness and high toughness, high hardness                               
                    and high strength, and high stiffness and high damping capability.                                 
             Col. 13, ll. 3-12 (emphasis added).                                                                       
                    Pyzik’s composite material is also capable of being coated with a layer of                         
             metal, such as copper: “If a sub-surface (below the magnetic media layer) coating                         
             is desirable, the sub-surface material may be metal (e.g., chromium, nickel, cobalt,                      
             silicon, aluminum, copper, titanium, or magnesium), metal alloy, metal oxide,                             

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