电子封装用低膨胀、高导热铜基复合材料的制备及其性能研究

发布时间：2018-01-09 15:00

本文关键词：电子封装用低膨胀、高导热铜基复合材料的制备及其性能研究　出处：《江苏大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着电子元器件朝着更小、更轻和更快的趋势发展,其集成化程度也急剧升高,伴随而来的是芯片发热量大幅增加,以及材料的受热变形,传统的Al和Cu等封装材料已无法满足其热性能要求,因此开发低膨胀、高导热封装材料成了一个必然趋势。本文以Cu为基体材料,以负热膨胀材料Sc_2W_3O_(12)和低热膨胀材料SiC为增强相,采用粉末冶金法制备了Cu/Sc_2W_3O_(12)和Cu/SiC/Sc_2W_3O_(12)复合材料,并对所得复合材料的微观结构和热性能进行了详细表征,主要研究内容及成果如下:(1)使用分步固相法制备的片状Sc_2W_3O_(12)粉为原料,和Cu粉按不同质量比混合均匀后,压制成Φ10mm×1.5mm的圆片,通过常压还原气氛烧结制备出Cu/Sc_2W_3O_(12)复合材料,通过扫描电镜(SEM)、X射线衍射仪(XRD)对其微观组织进行了表征,使用热机械分析仪(TMA)测定其热膨胀系数,用激光闪射仪(LFA)测量其导热系数。结果显示,复合材料热膨胀系数最小值为2.1×10~(-6)/K,当温度高于600℃时,复合材料内部出现了Cu_(0.4)W_(0.6)合金相,为避免合金化,选择600℃作为复合材料的烧结温度,但低于高致密度Cu的烧结温度,导致复合材料致密度不高,导热也受影响,导热系数最大值为77.5W/(m?K)。(2)为提高复合材料的致密度,选用真空热压烧结制备Cu/Sc_2W_3O_(12)复合材料,考察了Sc_2W_3O_(12)颗粒形貌和烧结温度对复合材料微观组织、热性能的影响。结果表明,以纳米Sc_2W_3O_(12)粉为原料,于700℃制备的~*Cu60复合材料的致密度最高,达到92.44%,且Cu基体形成了均匀、完整的网络状结构,有利于热量的传导,相应的~*Cu60复合材料的导热系数和热膨胀系数分别为243.99W/(m?K)和9.02×10~(-6)/K,硬度也达到了234.32HV。提高烧结温度到800℃后,小颗粒Sc_2W_3O_(12)出现了再结晶,*Cu60复合材料的热膨胀系数进一步降为7.27×10~(-6)/K,接近于Si或GaAs等芯片材料的热膨胀系数值,致密度下降为91.6%,相应的导热系数也下降为208.64W/(m?K),硬度下降为205.4HV,因考虑到封装材料对于低膨胀、高导热的应用要求,Cu/Sc_2W_3O_(12)复合材料的最佳热压烧结温度为800℃。(3)为了进一步改善Cu/Sc_2W_3O_(12)复合材料的热性能,引入纳米SiC颗粒作为第二增强相,采用真空热压烧结制备了Cu/SiC/Sc_2W_3O_(12)复合材料,研究了SiC含量及烧结温度对复合材料显微组织和热性能的影响,结果表明,SiC增强相的引入提高了复合材料的致密化烧结温度,当烧结温度提高到1000℃,烧结进行充分,断口形貌显示为规则的韧窝断口,且复合粉体的两种增强相颗粒分布均匀;纳米SiC粉末的加入增加了烧结活化能,促进了1000℃时熔融态Cu的流动,复合材料的最大致密度达到了92.86%,相应的热膨胀系数和导热系数分别为13.33×10~(-6)/K和251.18W/(m?K),其热膨胀系数有些偏高,不符合应用要求,而1000℃烧结所得60%Cu10%SiC30%Sc_2W_3O_(12)复合材料的热膨胀系数仅为7.12×10~(-6)/K,相应的导热系数为230.60W/(m?K),二者均满足封装材料的应用条件。
[Abstract]:Along with the electronic components towards smaller, lighter and faster development trend, the integration degree also increased dramatically, accompanied by the chip heat increase, and the thermal deformation of the material, the traditional Al and Cu packaging materials have been unable to meet the requirements of the thermal performance, due to the development of low expansion, high thermal conductivity packaging materials have become an inevitable trend. This paper takes Cu as the matrix material with negative thermal expansion material Sc_2W_3O_ (12) and low thermal expansion material SiC as reinforcement, Cu/Sc_2W_3O_ were fabricated by powder metallurgy (12) and Cu/SiC/Sc_2W_3O_ (12) composite materials, and the microstructure and thermal properties of the composite materials a detailed characterization, the main research contents and results are as follows: (1) using sheet Sc_2W_3O_ step solid phase preparation (12) powder and Cu powder in different mass ratio of mixing, pressing with diameter of 10mm * 1.5mm wafer, by means of it Reducing atmosphere sintering preparation of Cu/Sc_2W_3O_ (12) composite materials by scanning electron microscopy (SEM), X ray diffraction (XRD) on the microstructure were characterized using thermo mechanical analyzer (TMA) determination of the thermal expansion coefficient, using laser instrument (LFA) to measure the thermal conductivity coefficient. The results showed that composite thermal expansion coefficient of the minimum value is 2.1 * 10~ (-6) /K, when the temperature is higher than 600 DEG C, the composite appeared in Cu_ (0.4) W_ (0.6) alloy phase, in order to avoid alloying, 600 DEG C as sintering temperature of composite materials, but below the sintering temperature of high density Cu. The resulting composite material density is not high, thermal conductivity is also affected by the thermal conductivity, the maximum value is 77.5W/ (M? K). (2) to improve the density of the composite material, preparation of Cu/Sc_2W_3O_ using vacuum hot pressing sintering (12) composite materials, the effects of Sc_2W_3O_ (12) on the microstructure of composite particle morphology and sintering the temperature of the heat. Can the effect. The results showed that the nano Sc_2W_3O_ powder (12) as raw materials, ~*Cu60 composite material at 700 DEG C prepared by the highest density reached 92.44%, and the Cu matrix formed a uniform and complete network structure, is conducive to heat conduction, ~*Cu60 composite material corresponding to the thermal conductivity and thermal expansion the coefficient were 243.99W/ (M? K) and 9.02 * 10~ (-6) /K, the hardness reached 234.32HV. higher sintering temperature to 800 DEG C, small particles of Sc_2W_3O_ (12) appeared recrystallization, thermal expansion coefficient of *Cu60 composites is further reduced to 7.27 * 10~ (-6) /K, or close to Si the GaAs chip material thermal expansion coefficient, the density decreased to 91.6%, the corresponding thermal conductivity coefficient also decreases to 208.64W/ (M? K), hardness decreased to 205.4HV, due to packaging materials for low expansion, application requirements of high thermal conductivity, Cu/Sc_2W_3O_ (12) the best sintering temperature of the composite was 800 C. (3) Cu/Sc_2W_3O_ (12) in order to further improve the thermal properties of composite materials, the introduction of nano SiC particles as reinforcing phase second, Cu/SiC/Sc_2W_3O_ were prepared by vacuum hot pressing sintering (12) composite materials, studied the effects of SiC content and sintering temperature on the properties of the composite microstructure and thermal properties of the results show that SiC reinforcement could improve the densification of composites when the sintering temperature, sintering temperature increase to 1000 degrees Celsius, sintering sufficient, fracture morphology was the rules of the dimple, and the two kinds of particles were homogeneous composite powder; nano SiC powder was increased with the sintering activation energy, promote the flow of the molten Cu at 1000 DEG C, the maximum density reached 92.86% composites, the corresponding thermal expansion coefficient and thermal conductivity were 13.33 * 10~ (-6) /K and 251.18W/ (M? K), the thermal expansion coefficient of some high, does not meet the application It is required that the thermal expansion coefficient of 60%Cu10%SiC30%Sc_2W_3O_ (12) composite material sintered at 1000 C is only 7.12 * 10~ (-6) /K, and the corresponding thermal conductivity is 230.60W/ (M? K), two of which meet the application conditions of packaging materials.

【学位授予单位】：江苏大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB333

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