"Die attach" (or "die bonding") is the general term for the process of attaching a semiconductor chip (die) to a substrate or package.
Sintering is an advanced die attach method that uses a silver-based paste. This process forms a strong, highly reliable bond by heating the paste, either with or without pressure (pressurized or pressureless sintering). The resulting sintered silver joint features a very high melting point and excellent thermal conductivity, making it ideal for high-power and high-temperature applications, such as bonding semiconductor dies to DBC substrates.
In contrast, conventional die attach methods often use solder or epoxy adhesives. While effective for many applications, these materials typically have lower melting points and thermal conductivity compared to sintered silver.
X-ray inspection systems are crucial for quality control in these applications. They are used to non-destructively detect defects within the bond layer, such as voids, insufficient wetting, sintering shrinkage, and cracks, which can compromise the performance and reliability of the power module.