Common Die Attach-related Failure Mechanisms:

 

Die Lifting - detachment of the die from the die pad or cavity. Common Causes: contamination on the die pad or cavity, die backside contamination, excessive die attach voids, incomplete die attach coverage, inadequate die attach curing

    

Die Cracking - occurrence of fracture anywhere in the die. Common Causes in the context of Die Attach: excessive die attach voids, die overhang or insufficient die attach coverage, insufficient bond line thickness, excessive die ejection force on the wafer tape, absence of die attach voids

   

Adhesive Shorting - electrical shorting between exposed metal lines, bond pads, bonds, or wires as a result of adhesive accidentally dripping on the surface of the die (sometimes called 'epoxy on die').  Common Causes: incorrect die attach material viscosity, incorrect adhesive dispensation

     

Bond Lifting - lifting of the first or second bond from the die or leadfinger, respectively. From the die attach process point of view, this is often due to resin bleeding of the die attach material into the bond pads or leadfingers, inhibiting good intermetallic formation. See also Wirebonding.

     

Die Scratching - inducement of any mechanical damage on the die, as when an operator scratches a die with tweezers due to mishandling. Common Causes: insufficient operator training, worn-out or contaminated pick-and-place tool, disorderly workplace, use of improper tools

     

Die Metallization Smearing - depression or deformation of any metal line on the die surface. Common Causes: dirty or worn-out die attach pick-and-place tool, wafer mishandling

   

Front-End Assembly Links:  Wafer Backgrind Die Preparation Die Attach Wirebonding Die Overcoat

Back-End Assembly Links:  Molding Sealing Marking DTFS Leadfinish          

See Also:  Die Shear TestingDie Attach ToolsDie Attach Materials;  IC ManufacturingAssembly Equipment

      

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