The Preparation And Performance Of Magnesium Aluminun-silicon Glass-ceramics With Low Coefficient Of Thermal Expansion

The information technology has developed rapidly,which promots the development of integrated circuit systems in the direction of high density,ultra-large scale and multi-function,and has also made electronic packaging technology change with each passing day,which puts higher requirements on electronic packaging substrate materials.MgO-Al₂O₃-SiO₂ glass-ceramics have great potential in the field of LTCC packaging materials due to their low thermal expansion coefficient,high flexural strength and excellent dielectric properties.In this paper,MgO-Al₂O₃-SiO₂glass-ceramics was used as the research object,and to improve the overall performance of the system packaging materials by studying the basic formula and doping modification.In this experiment,low thermal expansion and high strength MgO-Al₂O₃-SiO₂glass-ceramics were selected as the object,and the effects of basic formulation and different doping on their microstructure,crystal phase,thermal expansion coefficient,flexural strength and dielectric properties were studied.In the MgO-Al₂O₃-SiO₂glass-ceramic system,Cr₂O₃ has obvious effect of promoting crystallization.The proper amount of Cr₂O₃ is doped,and the flexural strength is high,the thermal properties are relatively excellent.When the doping amount of Cr₂O₃ is 3wt%,the sample performance is best,with high flexural strength?180MPa?,low CTE(1.71×10^-6/°C),and low dielectric constant?5.50?.In the MgO-Al₂O₃-SiO₂ glass-ceramic system,Doping 2wt%amount of TiO₂,the sample performance is best,with high bending strength?184MPa?and low CTE(1.76×10^-6/°C).In the MgO-Al₂O₃-SiO₂ glass-ceramic system,B₂O₃ has obvious effect of reducing singtering temperature.,With the doping of B₂O₃ the microstructure of the sample is compact,the bending strengthis greatly improved,the dielectric and electrical properties are excellent.Doping 3wt%amount of B₂O₃,the sample performance is best,with high bending strength?229MPa?,and low CTE(1.66×10^-6/°C).In the MgO-Al₂O₃-SiO₂ glass-ceramic system,ZrO₂ has a significant effect of promoting crystallization,and reduces the sintering temperature of the glass-ceramic to some extent.Keep ZnO+ZrO₂=8wt%unchanged,and the Zn/Zr value is 5/3,the sample performance is best,with high flexural strength?279MPa?,low dielectric loss(=0.3×10^-3),and the CTE(3.46×10^-6/°C)matched Si chip's.In addition,this paper discusses several common calculation models of sintering kinetics,analyzes the sintering kinetics of MgO-Al₂O₃-SiO₂ glass-ceramics with different Zn/Zr ratios,and calculates the corresponding sintering activation energy.From the relationship between dynamic shrinkage and sintering temperature,it is found that the activation energy of sintering increases first and then decreases with the increase of Zn/Zr.The proper combination of ZrO₂ and ZnO can be used as a reducing agent and a nucleating agent for MgO-Al₂O₃-SiO₂ glass ceramics.Finally,this paper discussed the crystallization kinetics of this system through the introduction of the principle of Kissinger analysis and Ozawa analysis,and the crystallization activation energy of this system in two different methods was calculated and the error are less than 4%,which indicates appropriate doping can promote the crystallization and the sintering process of MAS glass-ceramics?...