Patent ID: 11875993
Assignee: CORNING INCORPORATED
Field: Other special machines (Mechanical engineering)
Classification: CPC B  H  C | IPC C  H

Claim 9:
10. The method according to claim 7 wherein the core layer has a core thickness tcore and the core glass has a core glass Poisson's ratio vcore and a core glass elasticity Ecore, the first clad layer and the second clad layer each have a thickness tclad and the clad glass has a clad glass Poisson's ratio vclad and a clad glass elasticity Eclad; and
wherein the step of selecting the effective CTE of the laminate sheet or wafer further comprises:
selecting the effective CTE αeff to be greater than, 2
      ⁢
      
       t
       clad
      
      ⁢
      
       E
       clad
      
     
     
      1
      -
      
       v
       clad
      
     
    
    ⁢
    
     α
     clad
    
   
   +
   
    
     
      
       t
       core
      
      ⁢
      
       E
       core
      
     
     
      1
      -
      
       v
       core
      
     
    
    ⁢
    
     α
     core
    
   
  
  
   
    
     2
     ⁢
     
      t
      clad
     
     ⁢
     
      E
      clad
     
    
    
     1
     -
     
      v
      clad
     
    
   
   +
   
    
     
      t
      core
     
     ⁢
     
      E
      core
     
    
    
     1
     -
     
      v
      core
     
    
   
  
 

and less than αcore, and
thinning the first clad layer and the second clad layer to produce thinned first clad layer and a thinned second clad layer each having a thickness tthinned within the range of from, t
        core
       
       ⁢
       
        E
        core
       
      
      
       1
       -
       
        v
        core
       
      
     
     ⁢
     
      α
      core
     
    
    -
    
     
      
       α
       eff
      
      ⁢
      
       t
       core
      
      ⁢
      
       E
       core
      
     
     
      1
      -
      
       v
       core
      
     
    
   
   
    
     
      
       α
       eff
      
      ⁢
      2
      ⁢
      
       E
       clad
      
     
     
      1
      -
      
       v
       clad
      
     
    
    -
    
     
      
       2
       ⁢
       
        E
        clad
       
      
      
       1
       -
       
        v
        clad
       
      
     
     ⁢
     
      α
      clad
     
    
   
  
  ·
  
   (
   
    1
    -
    P
   
   )
  
 

 to

 
  
   
    
     
      
       
        t
        core
       
       ⁢
       
        E
        core
       
      
      
       1
       -
       
        v
        core
       
      
     
     ⁢
     
      α
      core
     
    
    -
    
     
      
       α
       eff
      
      ⁢
      
       t
       core
      
      ⁢
      
       E
       core
      
     
     
      1
      -
      
       v
       core
      
     
    
   
   
    
     
      
       α
       eff
      
      ⁢
      2
      ⁢
      
       E
       clad
      
     
     
      1
      -
      
       v
       clad
      
     
    
    -
    
     
      
       2
       ⁢
       
        E
        clad
       
      
      
       1
       -
       
        v
        clad
       
      
     
     ⁢
     
      α
      clad
     
    
   
  
  ·
  
   (
   
    1
    +
    P
   
   )
  
 

where P is 0.1, 0.05, 0.02, 0.01, or 0.005.