【作者】 杨娟；

【导师】 李效东； 堵永国；

【作者基本信息】 国防科学技术大学 ， 材料科学与工程， 2006， 博士

【摘要】 低温共烧陶瓷（LTCC）技术是近年来微电子封装技术中发展最迅速的分支,其中关键技术——LTCC基板材料的研究受到广泛关注。国外公司如DuPont、Ferro对材料关键技术采取严格保密措施,以赚取高额利润。LTCC基板中无机材料的研制和对应流延工艺的研究对于实现LTCC技术国产化意义重大。本文首先对LTCC基板材料性能指标和国内外代表性材料体系进行了系统介绍和比较;研制出与国外成熟产品性能相当的MgO-Al₂O₃-SiO₂系微晶玻璃流延生带,掌握其性能影响因素;研究各种氧化物添加物对MgO-Al₂O₃-SiO₂系微晶玻璃性能影响;同时研究元素周期性对微晶玻璃性能的影响规律和探索生带技术在曲面金属/陶瓷复合材料制备方面的应用。设计和制备一系列MgO-Al₂O₃-SiO₂系微晶玻璃材料,主要氧化物MgO、Al2O3和SiO2的含量分别符合堇青石（Mg2Al4Si5O18）化学计量比和偏离堇青石化学计量比;研究微晶玻璃析晶特性影响因素,包括微晶玻璃组成、原始玻璃熔融温度、玻璃状态及玻璃粉粒径。利用示差扫描量热法（DSC）分析各玻璃样品,利用微晶玻璃的析晶峰值温度（Tp）和晶体生长速率（k（Tp））分析不同因素的影响。增加MgO-Al₂O₃-SiO₂系微晶玻璃中MgO含量有利于降低Tp,增大k（Tp）;而提高玻璃熔融温度会提高Tp,降低k（Tp）;经球磨获得的玻璃粉具有比块状玻璃样品低的Tp;粒径较小的玻璃粉具有较低的k（Tp）。舍弃析出石英相的非计量比微晶玻璃配方,对性能较好的MgO-Al₂O₃-SiO₂玻璃用不同热处理制度制备微晶玻璃样品。研究热处理制度中四大影响因素（形核温度、形核时间、析晶温度、析晶时间）对微晶玻璃烧结致密度、介电性能、热学性能的影响。提高形核温度能增大微晶玻璃烧结致密度,对微晶玻璃介电性能（1MHz）影响较小,形核温度为750℃时,微晶玻璃具有最大的热膨胀系数（4.93×10-6K-1）和最高软化温度（838℃）;形核时间对微晶玻璃烧结致密度和介电常数影响甚微,形核时间为60min时,微晶玻璃具有最大热膨胀系数（4.93×10-6K-1）,形核时间为90min时,微晶玻璃具有最高软化点温度（840℃）;微晶玻璃热膨胀系数随析晶温度上升而增大,析晶温度为950℃时,微晶玻璃烧结致密度出现最大值（98.85%）,并具有最高介电常数（5）和最高软化点温度（838℃）;析晶时间对微晶玻璃的烧结致密度影响甚微,随析晶时间延长,微晶玻璃介电常数降低,热膨胀系数增大,析晶时间为60min时具有最高软化温度（838℃）。选择三种氧化物P₂O₅、ZrO₂和Yb₂O₃作为MgO-Al₂O₃-SiO₂系微晶玻璃的添加物,通过研究加入这些氧化物的微晶玻璃析晶特性、析出晶相种类和晶粒形貌等判断该氧化物的形核能力。这三种氧化物对微晶玻璃的析晶速率值影响均较小;P2O5能促进玻璃分相,从而促进玻璃中晶相的析出,并能降低MgO-Al₂O₃-SiO₂系微晶玻璃中堇青石相析出温度;ZrO₂和Yb₂O₃对玻璃中晶相的析出稍有抑制作用;在微晶玻璃中添加P2O5和ZrO₂明显降低材料抗弯强度,添加量较多时（6wt% P2O5,4wt% ZrO₂）材料的介电常数和介质损耗急剧增大;Yb₂O₃能增强微晶玻璃抗弯强度,介电性能对Yb₂O₃保持稳定。基于同族元素性质的周期变化性,并根据氧化物对玻璃性质的作用原理,选择碱土金属氧化物MgO、CaO、SrO和BaO作原料,制备含相同摩尔量碱土金属离子的RO-Al₂O₃-SiO₂微晶玻璃。研究不同周期碱土金属离子对微晶玻璃析晶特性、烧结温度范围及各项物理性能的影响。实验结果表明,微晶玻璃的晶体生长速率随碱土金属元素周期数增加先减小后增大;950℃热处理1h后微晶玻璃抗弯强度随周期数增加先减小后增大,热处理时间延长至24h后,四种微晶玻璃抗弯强度值趋于相近;随周期数增加微晶玻璃的介电常数增大,热膨胀系数增大;随热处理时间延长,微晶玻璃的介电常数减小,热膨胀系数增大。制备MgO-Al₂O₃-SiO₂微晶玻璃流延浆料,研究各种因素,包括玻璃粉体粒径大小、粉体固含量、粘结剂用量、粘结剂/增塑剂含量比值（R）大小和分散剂含量对浆料流变特性的影响。当玻璃粉体粒径D50为2.23μm ,固含量为20²5vol%,粘结剂含量为15.5¹9 vol%,R值为0.65,分散剂用量为玻璃粉体质量的2%时可获得最佳流变特性的流延浆料。通过流延成型工艺制备MgO-Al₂O₃-SiO₂微晶玻璃生带,研究烧结前后生带性能影响因素,利用拉伸实验测量烧结前生带的强度和韧性,通过测量烧结后生带的密度和收缩率判断其烧结特性。实验结果表明,适当增加生带中粘结剂含量,选择合适的R值,并选用粒径较小的玻璃粉可提高烧结前生带的综合性能;减少粘结剂用量、选择适当的增塑剂含量,并选用粒径较大的玻璃粉则有利于获得烧结特性优良的生带。生带是一种有机高分子/陶瓷柔性复合膜,利用其性状及中间体特性可拓展其应用领域。本文在拓展生带技术应用领域做了探索性研究,包括制备曲面金属/微晶玻璃层状复合材料、用超细银粉与玻璃粉的混合物制备电阻生带以在LTCC技术中替代电阻浆料等。更多还原

【Abstract】 Low temperature co-fired ceramics （LTCC） developed rapidly as a kind of microelectric packaging technology. The substrate materials as the most important part of LTCC technology was broad attentioned. The substrate materials technology was kept as secret by DuPont and Ferro company to earn huge profits. Study of the inorganic materials in LTCC substrate and the corresponding tape-casting technics was seriously significative. In this paper, the properties targets and typical materials were introduced systemattically. The MgO-Al₂O₃-SiO₂ glass-ceramic green tape with properties near to the mature product was prepared. The influence factors to this green tape were mastered. The influence of oxide additives and the periodic properties of elements were studied . And the application fields of green tape were spread such as the preparing of the curve metal/ceramic composite materials.Series of MgO-Al₂O₃-SiO₂ glass-ceramics were designed and prepared. The contents of MgO, Al2O3 and SiO2 corresponded to the stoichiometric cordierite （Mg2Al4Si5O18） or not. The influence factors in crystallization kinetics of glass-ceramics includ the components, the melting temperatures of glass, the state of glass and the granularity of glass powder. The peak temperatures Tp and the crystallization rate constant k（Tp） of glass were used to analyze the influence by way of differential scanning calorimetry （DSC）. Increasing the content of MgO can decrease the Tp and increase the k（Tp） of MgO-Al₂O₃-SiO₂ glass-ceramics. The rising of melting temperature can increase the Tp and decrease the k（Tp）. The ground glass powder has lower peak temperatures than massive glass. And the finer glass powder has lower peak temperatures.The stoichiometric MgO-Al₂O₃-SiO₂ glass which had better properties was chosen to be heat-treated with different treat system. The main influence factors of heat treatment includ nucleating temperature, nucleating time, crystallizing temperature and crystallizing time. Such factors could influence the sintering properties, the dielectric properties and the coefficient of thermal expansion （CTE） of glass-ceramics. Increasing the nucleating temperature can raise the relative density of MgO-Al₂O₃-SiO₂ glass-ceramics. The influence of the nucleating temperature on the dielectric constant of glass-ceramics is not obvious. The highest CTE as 4.93×10-6K-1 and the highest softening point of glass as 838℃appear when the nucleating temperature is 750℃. The nucleating time has little influence to the relative density and dielectric constant of glass-ceramics. The highest CTE as 4.93×10-6K-1 appears when the nucleating time was 60 minutes. And the highest softening point as 840℃appears when the nucleating time is 90 minutes. The CTE of glass-ceramics increases with the inceasing of the crystallizing temperature. When the crystallizing temperature was 950℃, the maximal relative density as 98.85%, the maximal dielectric constant as 5 and the highest softening point as 838℃appears. The influence of crystallizing time to relative density of glass-ceramics is not obvious. The dielectric constant decreases and the CTE increase with the prolongation of crystallizing time. The highest softening point of glass as 838℃appears when the crystallizing time is 60 minutes.Three kinds of oxides, which are P2O5, ZrO₂ and Yb₂O₃, were chosen to be addtives of MgO-Al₂O₃-SiO₂ glass-ceramics. The nucleating ability of such oxides were determined by studing the crystallization kinetics, the kind and shape of crystal of the glass-ceramics with such oxides. The influence of such oxides to the crystallization kinetics of glass-ceramics is not obvious. P2O5 can promote the phase separation of glass and farther can promote the crystallization. The temperature of cordierite separating decreases with the adding of P2O5. ZrO₂ and Yb₂O₃ can restrain the separation of crystal. The adding of P2O5 and ZrO₂ can decrease the flexural strength of MgO-Al₂O₃-SiO₂ glass-ceramics. When the quantity is big enough （6wt% P2O5 and 4wt% ZrO₂） the dielectric constant and the loss tangent of glass-ceramics increase rapidly. Yb₂O₃ can enhance the flexural strength of glass-ceramics. At the same time the dielectric properties keep stable with the adding of Yb₂O₃. The CTE of glass-ceramics is influenced little by these oxides.The same mole of MgO, CaO, SrO and BaO were chosen to prepare RO-Al₂O₃-SiO₂ glass-ceramics for the periodic properties of such oxides. The influence of the periodic properties on glass-ceramics was studied by analyzing the crystallization kinetics, the sintering temperature range and the physical properties of such glass-ceramics. As the periodicity of alkaline earth ion R2+ increases, the peak temperatures of glass decrease, the sintering temperature ranges reduce, the flexural strengthes decrease firstly, and then increase.At the same time, the dielectric constants increase, and the CTE increases too. The prolongation of crystallization time makes the values of flexural strengthes centralized. The dielectric constants decrease and the CTE increases with the prolongation of crystallization time.The MgO-Al₂O₃-SiO₂ glass-ceramics tape casting slurry was prepared. The factors such as the size of glass powder, the content of glass powder, the content of binder, the ratio of binder to plasticizer （R） and the content of dispersing agent which would influence the rheology of slurry were studied. The results announce that if such conditions could be satisfied as the D50 of glass powder is 2.23μm, the volume content of glass powder is between 20% and 25%, the volume content of binder is between 15.5% and 19%, the R is 0.65 and the dispersing agent is 2wt% of glass powder, the slurry with best rheological properties can be gained.The MgO-Al₂O₃-SiO₂ glass-ceramics green tape was prepared by tape casting technics. The influence factors to properties of green tape were studied. The strength and flexibility of unfired green tape were measured by standard tensile strength test. The relative density and shrinkage of fired green tape were measured to estimate the sintering properties of green tape. The benefit factors to properties of unfired green tape include the increasing of the content of binder, a proper R value and the fine glass powder. And the benefit factors to sintering properties include the decreasing of the content of binder, a proper R and the coarse glass powder.As a kind of transitional technics, the development of green tape technics was influenced by the application field. Some work which can expand the application field is attempted in this paper. This work includes the preparing of curve surface metal/glass-ceramics composites and the Ag/glass resistance green tape that can substitute the resistance paste in LTCC technics.更多还原