Microwave nondestructive detection of delamination in IC packages utilizing open-ended coaxial line sensor

A new method of microwave nondestructive testing which utilizes an open-end ed coaxial line sensor is developed in an attempt to increase the spatial r esolution. With the aid of this technique, the delamination in IC packages is inspected. An open-ended coaxial line sensor with inner and outer conduc tors in smaller dimension than the wavelength is used to incident and recei ve the test signal that interacts with the detected objects. The magnitude of effective reflection coefficient, which is proportional to the total ref lection from different interfaces, is measured as a characteristic signal t o distinguish the delamination. A phenomenon of magnitude coherent resonanc e is observed in detail, by which the measurement sensitivity is enhanced s ignificantly. Four IC packages were used as samples, and the measurement re sults indicate that the microwave technique using an open-ended coaxial lin e sensor has a bright prospect to evaluate the delamination in IC packages nondestructively. (C) 1999 Elsevier Science Ltd. All rights reserved.