Robustness Evaluation of Adhesively Bonded Ceramic Quad Flat Chips for Space Applications

Abstract

Ceramic quad flat packs (CQFP) electronic components have long been used in power devices in the space industry. Soldering CQFPs to a printed circuit board (PCB) is not sufficient and thus the use of adhesives for reinforcement is compulsory. In fact, the risk of failure becomes very high during launch missions due to harsh constant and random accelerations. The paper investigates various distributions of two common thermally conductive and one epoxy adhesives. The intention is to compare the effects of these adhesive bonds on the robustness to vibrations of solder joints. Results are generated from a finite element (FE) model consisting of a CQFP component, an adhesive layer and a PCB. Key outputs such as the maximum deflection of the PCB, the stress in the solder joints and the fatigue lifetime of the assembly are discussed. Recourse to FE simulations allows competitiveness in terms of design cost and delivery time.