| With the rapid development of technology,the chip is characterized by high integration,high computing efficiency and low power consumption.Correspondingly,the electronic chip packaging material is required to achieve co-firing with the metal wires,and a low temperature co-fired ceramic?LTCC?material is required.Due to the superior comprehensive performance of BaAlBSi-based glass ceramic,it is used as secondary packaging material for chips.In this paper,the doping modification of the glass ceramic is mainly studied.The BaAlBSi-based glass ceramic samples were prepared by conventional solid phase method.In order to analyze the effects of doping different additives on the BaAlBSi material system,thermal property,mechanical properties,crystal phase composition,micrographs and electrical parameters of the doped samples are investigated,respectivly.With doping additive,it can be found that an appropriate amount of MnO promoted the crystallization of BaAlBSi glass ceramic,thereby improving the mechanical properties of BaAlBSi glass ceramic.When 1wt%MnO is blended,the bending strength of the glass ceramic sample increases to 201.2 MPa.The Young's modulus is 79.7 GPa.The excellent dielectric constant is 6.31.The dielectric loss is only 4.54×10-4 and the thermal expansion coefficient?CTE?is 11.7×10-6/°C,and the comprehensive parameters are optimal.Adding 0.5 wt%Bi2O3 into BaAlBSi glass ceramic can obtain a moderate packaging material with higher mechanical strength?bending strength:171.7MPa,Young's modulus:71.6GPa?,excellent dielectric constant??r=6.17?,low dielectric loss(tan?=7.10×10-4)and thermal expansion coefficient(CTE=11.8×10-6/°C),which can basically meet the requirements of secondary packaging materials.When the amount of doped Sm2O3 is 2wt%,the BaAlBSi glass ceramic sample has low dielectric constant?5.31?,low dielectric loss(5.30×10-4),high bending strength?171.6MPa?,high Young's modulus?79.7GPa?and high CTE value(11.8×10-6/°C).The sample performance is good,which indicates that the material can be applied to electronic packaging.When the doping amount of La2O3 in the material system is 0.5wt%,the bending strength is 168.5MPa.The Young's modulus is 74.9GPa.The dielectric constant is low?5.73?,and the dielectric loss is small(4.90×10-4).The CTE value is high and stable(11.7×10-6/°C).It proves that La2O3 improves the performance of the material system and this material can be suitable as a CBGA packaging material.Then,the CTE values of La2O3 and Bi2O3 doped BaAlBSi glass ceramic was calculated by the oxide method theory and the crystal phase method theory,respectively.Due to the relatively comprehensive consideration,the comparison shows that,the error between the theoretical calculation by the crystal phase method and the true measurement value is small,and the theoretical calculation of crystal phase method can truly reflect the change of the CTE value.The crystal phase method can use as a theoretical guide for the calculation of the thermal expansion coefficient.Finally,the sintering activation energy of BaAlBSi glass ceramic samples doped with MnO and Sm2O3,were studied,respectively.It can be found that doping MnO and doping Sm2O3 both can effectively reduce the sintering activation energy of the sample,promote the precipitation of the crystal phase from the glass phase of the sample and increase the content of crystal phase.MnO and Sm2O3 addition contribute to increase the grain size,improve the density inside the sample,and accelerate the glass ceramic sintering process... |
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