Multi-Chip Integration

The principal objective of this proposed effort is to develop a generic sensor for real-time verification of bonding integrity of materials at the micro-level, which include but are not limited to ball bonds, wedge bonds, solder joints, internal and external delamination of traces & lid sealing of microcircuit packages. As demonstrated in the following proposal, this will be a non-contact sensor with high speed, sensitivity and precision specifically for performing detection of micro-detachment of joining materials. The backbone of this technological thrust is base on recent development of illumin-optics technology for microelectronics by Simpex and laser ultrasonic technology by Idaho National Engineering Laboratory, Department of Energy. The measurement of the bond integrity of balls and wedges is accomplished through a non-contact method by using lasers for both generation and detection of ultrasonic waves passing through the bond. Simply, our Micro Laser Ultrasonic Optical Sensor represents an automation of the classical "tap test" in which an object is struck in some fashion and an experienced listener determines the adhesion integrity from the sound generated. This technique is much improved from the traditional ultrasonic/acoustic technique. The object need not be contacted, the excitation is much gentler than that required in a contact test, and the whole approach lends itself to automation. Anticipated Benefits: This effort will provide a strong foundation for high resolution and high speed sensors for determining attachment integrity of micro-dimensional material layers. This technology can be adapated to numerous applications such as thick film & thin film, deposition processes for microelectronics, joining of metals and other joining processes with unknown micromechanical properties. These sensors will help reduce scrap, down time, eliminate many manual inspection steps, save time and money,and increase quality.