Synergistic enhancement of mechanical and thermal properties in AlN ceramics via laminated distribution of Sm2O3 and Y2O3 sintering additives

AlN ceramics are widely used in integrated circuit thermal management and packaging materials due to their excellent thermal conductivity, insulating properties, and thermal expansion coefficient similar to silicon. However, traditional hot-press sintering processes often struggle to produce homogeneous AlN ceramics that combine high thermal conductivity with excellent flexural strength. Furthermore, different sintering additives used in AlN ceramics have varying effects on their mechanical and thermal properties. Therefore, this study first conduct a preliminary screening of five different sintering additives and select two specific sintering additives for the laminate design. The Sm 2 O 3 additive demonstrates the highest flexural strength while the Y 2 O 3 additive showcases the highest thermal conductivity. Subsequently, laminated AlN ceramics with Sm 2 O 3 additive in the surface and Y 2 O 3 additive in the intermediate layer are fabricated to synergistically improve the strength and thermal conductivity. The laminated AlN ceramic exhibits a thermal conductivity of 150 W m −1  K −1 and a flexural strength of 458 MPa. These improvements are attributed to enhanced fine-grain strengthening coupled with its dense structure and isolated secondary phase distribution. This work provides a feasible strategy for synergistic enhancement of mechanical and thermal properties in AlN Ceramics via laminated distribution of sintering additives.