Abstract
The method of digital speckle correlation is introduced, and so is the hardware system to implement the method. The advantages and the features of the technique are discussed, and application examples are given. Owing to the high spatial resolution that this technique can achieve, the method is especially useful in measuring small areas of an object, or a small component in an assembly, whether the surfaces under probing are planar or not. The applications have proved that the technique is a promising tool for the reliability study of microelectronic packages.