Environmentally Friendly Gel Tape Casting of Silicon Nitride Ceramic Substrates with Enhanced Thermal Conductivity

• Published in: SILICON Vol. 17; no. 5; pp. 1091 - 1101
• Main Authors: Liu, Yuanfei, Fu, Jie, Liu, Yuan, Gao, Zhengxia, Ma, Chengliang
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.04.2025; Springer Nature B.V
• Subjects: Acrylamide; Activated sintering; Additives; Casting; Casting defects; Ceramics; Chemistry; Chemistry and Materials Science; Copolymers; Depolymerization; Electronic packaging; Environmental Chemistry; Flakes (defects); Flexural strength; Fracture toughness; Heat conductivity; Heat transfer; Inorganic Chemistry; Lasers; Maleic anhydride; Materials Science; Mechanical properties; Methylene bisacrylamide; Optical Devices; Optics; Photonics; Polymer Sciences; Rheological properties; Semiconductors; Shear thinning (liquids); Silicon nitride; Silicon substrates; Sintering; Sintering aids; Slurries; Specific gravity; Thermal conductivity; Zirconium dioxide; Heat conduction; Silicon nitride ceramic substrates; Sol–gel processes; Sintering
• ISSN: 1876-990X; 1876-9918
• DOI: 10.1007/s12633-025-03234-6

With the development of third-generation semiconductors, the heat dissipation problems of electronic packaging systems and the harsh usage environment of high-power devices have put forward higher requirements on the thermal conductivity and mechanical properties of silicon nitride ceramic substrates. As an almost defect-free ceramic forming technology, aqueous gel tape casting technology is very suitable for the forming of ceramic substrate materials because of the high density, low porosity and large forming size of the ceramic flakes produced. However, the existing acrylamide-methylene bisacrylamide (AM-MBAM) gel system has a complicated process, is subject to oxygen depolymerisation and has problems such as neurotoxicity. For this reason, in this study, a non-toxic and environmentally friendly isobutylene-maleic anhydride copolymer (Isobam) gel system was used to prepare silicon nitride ceramic substrates in-situ by combining the methods of gel tape casting and reaction sintering. The rheological properties of the slurry were optimized by adjusting the dosage of additives, and the effects of the nitriding reaction process of silicon powder and different sintering aids on the properties of Si3N4 ceramic substrates after resintering were investigated in detail. The results show that the slurries with different additive contents show shear-thinning behaviour and relatively high solid content. Under 0.1 MPa nitrogen atmosphere, Si 3 N 4 has been basically completely generated at 1400 °C, and the comprehensive performance of Si 3 N 4 ceramics is optimal with the addition of Y 2 O 3 -MgO-ZrO 2 sintering additives. The relative density and thermal conductivity were 98.4% and 61.5 W·m −1 ·K −1 , respectively, and Si 3 N 4 showed columnar morphology, which effectively improved the hardness, fracture toughness and flexural strength of Si 3 N 4 ceramics, up to 13.39 GPa, 6.9 MPa·m 1/2 and 684.5 MPa, respectively.