功率半导体模块用陶瓷覆铜基板质量测试评价体系的研究

功率模块用陶瓷覆铜基板在电子行业中应用广泛,其质量对整个电子产品的性能和可靠性具有重要影响。本文综述了功率模块用陶瓷覆铜基板的发展现状,阐述了功率模块用陶瓷覆铜基板的质量评价相关性能要求,探索功率模块用陶瓷覆铜基板性能评价指标、测试方法,最终建立一套以市场为导向的,具有系统性、先进性和时效性的,涵盖产品性能符合性/工艺流程稳定性/服役适用性的功率模块用陶瓷覆铜板试验评价体系。通过实验测试和数据分析,建立质量评价的依据,使覆铜板生产单位和模块生产单位的工艺缺陷变得数据化、可计量,明确了自身产品性能表征指标,为工艺改进提供了评价标准和前进方向,为功率模块用陶瓷覆铜基板的质量控制提供了有力支持。     

氮化铝陶瓷覆铜基板的研制

通过高温热氧化的方法,在ＡＩＮ陶表面形成一薄层ＡＩ２Ｏ３作为过渡层,成功地将铜与ＡＩＮ陶瓷键合在一起,研制出性能优越的ＡＩＮ陶瓷覆铜基板。研究了ＡＩＮ热氧化时间及温度对键合质量的影响,提出子较佳的儿得的键合力可达１１０Ｎ／ｃｍ,同时,运用扫描电镜（ＳＥＭ０、电子能谱（ＥＤＸ）对键合结构作了分析和研究。ＡＩＮ衬底上的氧化物相对键合过程中上重要作用。     

直接敷铜陶瓷基板及制备方法

直接敷铜技术是基于氧化铝陶瓷基板发展起来的一种陶瓷表面金属化技术,随着大功率模块与电力电子器件的发展与要求,直接敷铜已从氧化铝陶瓷基板发展到其他陶瓷基板。介绍了国内外陶瓷基板直接敷铜技术、理论研究、新进展和今后的发展趋势。     

氮化硅陶瓷的制备及进展

本文着重介绍了氮化硅陶瓷的制备工艺，提高氮化硅陶瓷高温性能的方法以及改善其断裂韧性的途径，并展望了氮化硅陶瓷的研究前景。     

三维网络结构多孔氮化硅陶瓷增强体的制备

以Si3N4和Si粉为主要原料,Al2O3、Y2O3等为助剂,制备Si3N4料浆,用有机前驱体浸渍和二次烧成工艺来制备具有网络结构的多孔氮化硅陶瓷增强体.结果表明:二次烧成能显著提高材料性能,烧成温度在1600～1700℃为宜.用XRD、SEM、XEDS等对二次烧成材料的显微结构和晶相进行分析,研究二次烧成制度改善材料性能的原因,以利于更好的优化工艺.     

氮化硅陶瓷的制备及进展

本文着重介绍了氮化硅陶瓷的制备工艺,提高氮化硅陶瓷高温性能的方法以及改善共断裂韧性的途径,并展望了氮化硅陶瓷的研究前景。     

氮化硅陶瓷的制备及进展

本文郑重介绍了氮化硅陶瓷的制备工艺、提高氮化硅陶瓷高温性能的方法以及改善其断裂韧性的途径,并展望了氮化硅陶瓷的研究前景。     

氮化硅陶瓷的制备及性能研究进展

氮化硅陶瓷是一种具有广阔发展前景的高温、高强度结构陶瓷,它具有强度高、抗热震稳定性好、疲劳韧性高、室温抗弯强度高、耐磨、抗氧化、耐腐蚀性能好等高性能,已被广泛应用于各行业。本文介绍了氮化硅陶瓷的基本性质．综述了氮化硅陶瓷的制备工艺和提高其高温性能的方法以及增韧的途径,并展望了氮化硅陶瓷的发展前景。     

氮化硅/环氧复合电子基板材料制备及性能

以Si_3N_4粉末作为增强组分与环氧树脂进行复合,采用模压法制备了氮化硅/环氧树脂复合电子基板材料。研究了Si_3N_4含量对复合材料导热性能和介电性能的影响。研究结果表明,随着Si_3N_4含量的增加,复合材料中填料形成导热网络,复合材料的热导率也随之增加,当体积填充量为35%时,导热系数达到1．71 W/m·K。复合材料的介电常数随Si_3N_4含量的增加而增加,但在氮化硅陶瓷颗粒的体积分数达到35%时仍维持在较低的水平(7．08,1 MHz)。     

烧结助剂对氮化硅陶瓷热导率影响的研究进展

随着大规模、超大规模集成电路的发展,以及集成电路在通讯、交通等领域的运用。对于基板材料的要求日益严苛,氮化硅陶瓷因为有着优异的力学性能、介电性能和导热性,是作为基板材料的重要候选材料之一。氮化硅陶瓷的理论热导率高达200-320 W/(m·K),但是实际上高热导率的氮化硅难以制成。随着科研者将精力投入到氮化硅上,近年来氮化硅陶瓷的实际热导率得到提高,但是与理论热导率还有着不少差距。据文献记载,选择合适的烧结助剂能够有效的提高氮化硅陶瓷的热导率。本文综述了不同种类的烧结助剂对氮化硅陶瓷热导率的影响。     

Fabrication of Machinable Silicon Carbide-Boron Nitride Ceramic Nanocomposites

SiC/BN nanocomposite powders with the microstructure of micrometer-sized SiC particles coated with nanometer-sized BN particles were prepared via a chemical reaction, which used a mixture of boric acid (H₃BO₃) and urea (CO(NH₂)₂) as reactants coated on the surface of the SiC particles to react under a nitrogen-gas atmosphere. The results of XRD, TEM, and SAED studies showed that the coating layer (BN) was composed mostly of amorphous and nanometer-sized BN particles at the reaction temperature of 850°C. When the nanocomposite powders were hot-pressed at 1850°C, machinable SiC/BN ceramic nanocomposites with fine grain size and homogeneous microstructure were fabricated. The composite that contained 20 wt% BN exhibited high strength (the three-point bending strength was 588.4 ± 26.8 MPa) and excellent machinability.     

热压烧结工艺制备Si/SiC陶瓷的研究

α—SiC粉末为原料,Si为助烧剂,采用适当的热压烧结工艺,在1800℃,25MPa条件下获得了致密的SiC块体陶瓷,其抗弯强度为253MPa。     

A Simple and Cost-Effective Approach to Fabrication of Dense Ceramic Membranes on Porous Substrates

A simple and elegant approach to fabrication of dense ceramic membranes on porous substrates, a traditional dry pressing of foam powders, has been developed to reduce the cost of fabrication. Gd-doped ceria (GDC, Gd_0.1Ce_0.9O_1.95) electrolyte membranes as thin as 8 μm are obtained by dry-pressing highly porous GDC powders. The membrane thickness can be readily controlled by the amount of powder. The electrolyte membranes are studied in a solid-oxide fuel cell (SOFC) with air as oxidant and humidified hydrogen (3% H₂O) as fuel. Open-circuit voltages of about 1.0 V are observed, implying that the permeability of the membranes to molecular gases is insignificant. Power densities of 140 and 380 mW/cm² are demonstrated at 500° and 600°C, respectively, representing a significant progress in developing low-temperature SOFCs.     

Joining of Silicon Nitride by Local Heating for Fabrication of Long Ceramic Pipes

This study demonstrated that a long silicon nitride pipe of several meters with adequately strong joints can be fabricated by a local‐heating joining technique. Commercially available silicon nitride ceramic pipes sintered with Y₂O₃ and Al₂O₃ additives were used for parent material, and powder slurry of Si₃N₄‐Y₂O₃‐Al₂O₃‐SiO₂ system was brush‐coated on the rough or uneven end faces of the pipes. Joining was carried out by locally heating the joint region at different temperatures from 1500°C to 1650°C for 1 h with a mechanical pressure of 5 MPa in N₂ flow; using a horizontal electrical furnace specially designed for this experiment. The silicon nitride pipe 3‐m long was successfully fabricated without voids or cracks in the joint region, and the microstructure of the joint region was similar to that of the parent one. The joint strength was examined in flexure using specimens cut from the joined pipes, and those joined at 1600°C and 1650°C indicated the highest strength of about 680 MPa, which was almost the same as that of the parent material. This study also indicated that the slurry brush‐coating technique is advantageous to easily joining ceramic pipes with rough or uneven end faces, which is essentially important for practical use.     

Fabrication and Characterization of Ceramic Foams Based on Silicon Carbide Matrix and Hollow Alumino-Silicate Spheres

Closed-cell foams were fabricated by incorporating two different grades of hollow alumino-silicate spheres (cenospheres) into a silicon carbide matrix. The matrix was formed by the pyrolysis of a preceramic polymer, and multiple polymer infiltration and pyrolysis (PIP) cycles were employed to minimize the open voids in the material. The physical, mechanical and thermal properties of the fabricated foams were characterized as functions of the number of reinfiltration cycles. The open- and closed-void volume fractions were determined by measurements of bulk and skeletal densities. Mechanical properties, including strength and modulus, were evaluated using four-point bend and compression tests. Finally, thermal properties of the material, including the coefficient of thermal expansion and the thermal conductivity, were determined using dilatometry and the laser-flash technique, respectively. This processing technique results in closed-cell syntactic foams with minimal porosity (∼2–4%), reasonable mechanical strength (∼30 MPa) and very low thermal conductivity (≤1 W/m·K). In this manner, this process can be used for the low-cost and net-shape fabrication of closed-cell silicon carbide-based syntactic foams for high-temperature applications.     

Ceramic Coatings on Ceramic Substrates by Liquid Metal Transfer

A variety of ceramic coatings have been put on ceramic substrates by the molten metal transfer technique. In the diffision coating process a reactant metal dissolved in a molten "transfer agent" metal reacts with a substrate to form the coating. Titanium dissolved in molten tin has been reacted with silicon carbide, aluminum nitride, and silicon nitride substrates to produce titanium carbide and titanium nitride coatings, respectively. Similarly tantalum metal has been reacted to form carbide or nitride coatings. The unreacted tin is finally removed by decantation followed by acid leaching.     

Fabrication of Functionally Graded and Aligned Porosity in Thin Ceramic Substrates With the Novel Freeze–Tape-Casting Process

Functionally graded and continuously aligned pore structures have been fabricated by a modified tape-casting process for use as solid oxide fuel cell electrodes, catalysts, sensors, and filtration/separation devices. Pore gradients from <5 to 100 μm and aligned pore tubules have been directly fabricated in various ceramic materials with thin substrate sections approximately 500–1500 μm utilizing both low-toxicity aqueous-based slips and organic solvents. This process allows for the generation of pores without the use of thermally fugitive pore formers in a single processing step with no need for tape lamination. The incorporation of tape casting, unidirectional solidification, and the freeze-drying process results in uniformly acicular pores aligned with the direction of the moving carrier film. Processing and microstructure variability will be discussed as it pertains to the effects of solids loading, freezing temperatures, and solvent type. Applications for this ceramic processing technology will also be discussed.     

Cast (Self-Flow) Ceramic Castables. 3. Rheotechnological Properties of Molding Systems for Fabrication of Silicon Carbide Ceramic Castables

Results of a study of the rheotechnological properties of high-alumina suspensions with a granular silicon carbide filler are presented. It is shown that the rheological behavior of the suspensions changes with the introduction of the filler. The dependence of the effective and relative viscosities on the volume fraction of the filler is considered, and η_min is calculated for systems with nonuniform chemical composition. The minimum viscosity of filled suspensions is shown to obey the Pivinskii equation for chemically uniform and nonuniform systems. The minimum distance between the filler grains is determined depending on the amount of the filler and its mean grain size.     

Fabrication of Ceramic Hip Implant Composites: Influence of Silicon Nitride on Physical,Mechanical and Wear Properties

This study examined the effects of silicon nitride reinforcement on physical, mechanical and wear properties of different ceramic (zirconium oxide, magnesium oxide, chromium oxide and aluminum oxide) containing hip implant composites. The hip implant composites were produced using conventional mixing and spark plasma sintering methods by substituting aluminum oxide (68, 70.5, 73 and 75.5 wt.%) with silicon nitride (0, 2.5, 5 and 7.5 wt.%). Experimental results showed that silicon nitride content had significant effect on the evaluated physical, mechanical and wear properties. The density of the composites found to decrease whereas void content, Young’s modulus, hardness, wear resistance and fracture toughness first decreased (for 2.5 wt.%) and then increased with the increasing amount of silicon nitride content. The maximum hardness, Young’s modulus, wear resistance and fracture toughness values of 28.64 GPa, 280.18 GPa, 0.0076 mm³/million cycles and 11.84 MPa.m^1/2, respectively were registered for 2.5 wt.% silicon nitride additions that also had the lowest void content (0.38%).