Adhesives interconnection systems are now commonly used in flip chip package for bonding metallic bump to substrate metallization. However, one major limitation of these adhesives is the problem of degradation in the mechanical contact between bump and substrate metallization which causes drastic increase in contact resistance. This problem is caused by the stress relaxation of the adhesive over a period of time. In addition, because these devices are subjected to variations in electrical and thermal loads, they experience corresponding cyclic mechanical straining which results in cyclic relaxation that has distinguished characteristic apart from static relaxation. The study showed that cyclic relaxation has dependency on hold time, no-load time and ramp rate. PSpice modeling has been used to understand the cyclic relaxation phenomenon in the adhesives. The accuracy of PSpice modeling used to mimic the linear viscoelasticity behavior of the adhesive has been found to be within 5% error compared to the experimental results. (C) 2004 Elsevier B.V. All rights reserved.