Self‐Healing Technology for Metallic Die Attach Materials in Electronics

Abstract

Wideband gap (WBG) semiconductors are expected to be widely used in hybrid, electric, and fuel cell vehicles due to their high efficiency operation and possibility for system size reduction. These semiconductor devices are bonded to a substrate using solder or a high temperature capable thermal interface material also known as die attach. Device operating temperatures >200 °C are likely to put additional stress on the bonding system, which may result in thermal fatigue and cracks. Here, the authors report a self‐healing core‐shell capsule within the device attachment layer for self‐healing of cracks. Through proof‐of‐concept experiments, the authors demonstrate that at high temperature and pressure, the platinum shell layer of the composite capsule intentionally breaks, releasing the core indium material into the surrounding solder. The indium released from the capsule propagates through and remains confined inside the bond layer. Refinement of this technology is expected to provide a mechanism for prolonging the life of future WBG power modules.