Stress analysis of “Micro-Bump Bonding” structure for“Chip on glass” packaging

摘要

Micro-Bump Bonding (MBB) method makes possible the micro-orderdirect bonding between IC electrode and circuit substrate electrode. Thetechnology consists of three elements: an IC chip with bumps, a circuitsubstrate, and a bonding adhesive. The binding forces of the appliedadhesive accomplish electrical connection between the bumps on the ICchip and the electrodes on the substrate. Stress analysis is made toestimate the contact force that the adhesive imposes to drag togetherthe bumps of the IC and the electrodes of the substrate. An elasticmodel is assumed herein to determine the stress characteristic of theMBB structure. The stresses of the structures with gold bumps andcompliant bumps are compared at various temperatures. Such a stressanalysis is helpful in determining which kind of bumps is more suitablefor a given MBB structure