Preparation And Properties Of MgO-Al₂O₃-SiO₂ High Strength Substrate Materials

VLSI is developing in the direction of high integration,multi-function and low cost,and there is an urgent need to propose a new generation of high-density packaging materials.For the primary packaging of silicon chips,it is necessary to solve the problem of thermal mismatch between the substrate and the silicon-based chip,and to improve the thermal stability of the packaging.In addition,mechanical properties are also key parameters to measure the performance of substrate materials.In this thesis,the Mg O-Al₂O₃-Si O₂ glass-ceramics has been studied,and its various performance indicators have been improved,which is expected to be applied in the field of primary packaging.this thesis systematically explores the effects of different oxide doping on the crystallization mechanism,microstructure,thermal,mechanical and dielectric properties of Mg O-Al₂O₃-Si O₂ glass-ceramics.0.1wt%Yb₂O₃ doping is beneficial to the precipitation of Indialite,the thermal expansion coefficient（CTE）decreases to 3.40×10^-6/℃,which can match the silicon chip.At the same time,it has high flexural strength（182MPa）,The dielectric constant and dielectric loss are 6.18 and 1.9×10^-3,respectively.Tm₂O₃ doped with 0.5wt%has the best performance,high bending strength（175.8 MPa）,low CTE value(3.16×10^-6/℃),low dielectric constant（5.99）.Co O doping can significantly change the crystal phase composition of Mg O-Al₂O₃-Si O₂ glass-ceramics,inhibit the precipitation of Indialite,and precipitate a large amount of high-expansion phase(Mg Al₂Si₃O₁₀)_0.6and MgSiO₃,which eventually leads to a significant increase in the CTE value.When the Co O doping amount is 0.1wt%,the best performance is achieved,the dielectric constant is 5.8,and the dielectric loss is 3.2×10^-3,the flexural strength is 234.7 MPa.BaO doping increases the crystallization peak temperature of Indialite,which makes it difficult to precipitate from glass,and facilitates the crystallization of the intermediate phase(Mg Al₂Si₃O₁₀)_0.6 and stabilizes its content.Excessive BaO doping produces a new phase Ba Mg₂Al₆Si₉O₃₀.The best performance is obtained when the BaO doping content is 3wt%,the flexural strength is 310 MPa,the Young’s modulus is 109.3 GPa,the dielectric constant is 6.01,the dielectric loss is 2.5×10^-3,and the CTE value is 4.52×10^-6/°C.Finally,the effects of different oxide doping on the sintering process and crystallization mechanism of the Mg O-Al₂O₃-Si O₂ system were investigated according to the sintering kinetics and crystallization kinetic models.Based on the Arrhenius equation,the sintering activation energy of BaO and Yb₂O₃ doped Mg O-Al₂O₃-Si O₂glass-ceramics was calculated.We found that 0.1wt%Yb₂O₃ or 3wt%BaO can reduce the sintering activation energy of the system,which is helpful for the sintering and densification of the glass-ceramics.The crystallization activation energy of BaO and Yb₂O₃ doped Mg O-Al₂O₃-Si O₂ glass-ceramics was characterized based on Kissinger crystallization kinetics analysis method.The results show that BaO doping increases the crystallization activation energy of the system.To a certain extent,the precipitation of Indialite is inhibited.However,Yb₂O₃ doping significantly reduces the crystallization activation energy of the system,increases the crystallinity of the system,and has the effect of a nucleating agent.