A Novel Structure for Backside Protection Against Physical Attacks on Secure Chips or SiP

Abstract : A structure intended to protect Integrated Circuits (IC) against physical attacks is presented. Located on the backside of a chip, it complements the countermeasures usually available on the front side of secure components. It aims at preventing attacks such as fault injection by laser illumination and can trigger an alert in case of invasive attacks by circuit edit or micro-probing. Weakening structures have been designed so as to cause the breakage of the die in case of thinning, and a metallic serpentine used as an attack witness has been thought with a maximal complexity so that an attacker cannot skirt it. These elements can be fabricated using standard packaging techniques in a wafer level integration, whether at chip or system scale. The concept of a secure System in Package (SiP) using unsecured chips is proposed, opening the perspective of components fully "secured by packaging".