US Patent 7495759 Damage and wear detection for rotary cutting blades

A method of detecting wear and damage to a rotary cutting blade for singulating a substrate is provided comprising the steps of providing a sensor to locate a first detecting position at an edge of the blade and performing dicing with the blade while the sensor is maintained substantially at the first detecting position for detecting damage to the blade. Subsequently, an extent of wear of the blade is determined by driving the sensor in the direction of the blade to locate a second detecting position at the edge of the blade as a diameter of the blade is reduced due to dicing. Thereafter, while dicing is performed with the blade, the sensor is maintained substantially at the second detecting position for detecting damage to the blade.