Patent ID: 11953538
Assignee: WUHAN UNIVERSITY
Field: Measurement (Instruments)
Classification: CPC G | IPC G

Claim 1:
2. The method according to claim 1, wherein step S1 further comprises:
S1.1: representing the failure probability distribution of the solder layer through, f
     1
    
    (
    N
    )
   
   =
   
    
     
      m
      1
     
     
      η
      1
     
    
    ⁢
    
     
      (
      
       N
       
        η
        1
       
      
      )
     
     
      
       m
       1
      
      -
      1
     
    
    ⁢
    
     e
     
      -
      
       
        (
        
         N
         /
         
          η
          1
         
        
        )
       
       
        m
        1
       
      
     
    
   
  
  ,, representing the failure probability distribution of the bonding wire through, f
     2
    
    (
    N
    )
   
   =
   
    
     
      m
      2
     
     
      η
      2
     
    
    ⁢
    
     
      (
      
       N
       
        η
        2
       
      
      )
     
     
      
       m
       2
      
      -
      1
     
    
    ⁢
    
     e
     
      -
      
       
        (
        
         N
         /
         
          η
          2
         
        
        )
       
       
        m
        2
       
      
     
    
   
  
  ,, wherein N is a number of IGBT cycles, f1(N) is a failure density function of the solder layer, f2(N) is a failure density function of the bonding wire, m1 is a shape parameter of the failure density function of the solder layer, m2 is a shape parameter of the failure density function of the bonding wire, n1 is a size parameter of the failure density function of the solder layer, and n2 is a size parameter of the failure density function of the bonding wire; and
S1.2: combining the failure probability distribution of the solder layer and the failure probability distribution of the bonding wire to obtain a simultaneous failure probability model, f
     IGBT
    
    (
    N
    )
   
   :
   
    
     f
     IGBT
    
    (
    N
    )
   
  
  =
  
   
    e
    
     -
     
      [
      
       
        
         (
         
          N
          /
          
           η
           1
          
         
         )
        
        
         m
         1
        
       
       +
       
        
         (
         
          N
          /
          
           η
           2
          
         
         )
        
        
         m
         2
        
       
      
      ]
     
    
   
   [
   
    
     
      
       m
       1
      
      
       η
       1
      
     
     ⁢
     
      
       (
       
        N
        
         η
         1
        
       
       )
      
      
       
        m
        1
       
       -
       1
      
     
    
    +
    
     
      
       m
       2
      
      
       η
       2
      
     
     ⁢
     
      
       (
       
        N
        
         η
         2
        
       
       )
      
      
       
        m
        2
       
       -
       1
      
     
    
   
   ], of a IGBT circuit.