Patent ID: 7091062

Claim:
A method for producing a wafer level package, the method comprising; providing a semicondctor wafer having a chip side and a back side; thinning the back side of the wafer to an intended thickness; attaching a wafer-sized fiber reinforced synthetic resin sheet onto the wafer to form a wafer assembly that inchides the wafer and the fiber reinforced synthetic resin sheet; sawing into the wafer assembly from the chip ‘side to a predetermined depth to form kerfs; applying a polymer to the chip side of the wafer assembly so that inner surfaces of the kerfs are coated with the polymer, end sawing the wafer assembly into individual chips wherein applying a polymer comprises applying a light-sensitive polymer to thc chip side of the wafer assembly and exposing and developing the light-sensitive polymer to the chip side of the wafer assembly and exposing and developing the light-sensitive polymer so that the inner surfaces of the kerfas are coated with the polymer.