共查询到20条相似文献,搜索用时 15 毫秒
1.
A new bonding process using an Ag2O paste consisting of Ag2O particles mixed with a triethylene glycol reducing agent has been proposed as an alternative joining approach for microsoldering in electronics assembly, which currently uses Pb-rich, high-temperature solders. Ag nanoparticles were formed at approximately 130°C to 160°C through a reduction process, sintered to one another immediately, and bonded to a metal substrate. An Au-coated Cu specimen was successfully bonded using the Ag2O paste. The resulting joint exhibited superior strength compared with joints fabricated using conventional Pb-rich solders. To improve ion-migration tolerance, the Ag2O paste was mixed with Au and Pd microparticles to form sintered Ag-Au and Ag-Pd layers, respectively. The additions of Au and Pd improved the ion-migration tolerance of the joint. Regarding the mechanical properties of the joints, addition of secondary Au and Pd both resulted in decreased joint strength. To match the joint strength of conventional Pb-10Sn solder, the mixing ratios of Au and Pd were estimated to be limited to 16?vol.% and 7?vol.%, respectively. The electrical resistivities of the sintered layers consisting of 16?vol.% Au and 7?vol.% Pd were lower than that of Pb-10Sn solder. Thus, the additive fractions of Au and Pd to the Ag2O paste should be less than 16?vol.% and 7?vol.%, respectively, to avoid compromising the mechanical and electrical properties of the sintered layer relative to those of contemporary Pb-10Sn solder. Following the addition of Au and Pd to the paste, the ion-migration tolerances of the sintered layers were approximately 3 and 2 times higher than that of pure Ag, respectively. Thus, the addition of Au was found to improve the ion-migration tolerance of the sintered Ag layer more effectively and with less sacrifice of the mechanical and electrical properties of the sintered layer than the addition of Pd. 相似文献
2.
Tomohiro Yamakawa Tadashi Takemoto Masayoshi Shimoda Hiroshi Nishikawa Kunio Shiokawa Nobuto Terada 《Journal of Electronic Materials》2013,42(6):1260-1267
We investigated a new low-temperature bonding process utilizing Cu nanoparticle paste without addition of sintering promoter. Joint bonding strengths above 30 MPa were achieved even at a low bonding temperature of 250ºC. We attribute the higher bonding strengths of joints fabricated using the vacuum preheating process to the rapid progression of Cu nanoparticle sintering due to the activated nanoparticle surface at lower temperatures. The increase in bonding strength depended on the applied pressure, in addition to the bonding temperature. The formation of a dimple-like morphology was confirmed in the ductile fracture area. This indicated that the joint bonded strongly with the bonding layer, in agreement with the results of bonding tests carried out on strongly bonded joints. The bonding ability of the joints obtained using Cu nanoparticle paste could be improved by controlling the joint fabrication conditions. 相似文献
3.
4.
以钛酸丁酯为无机原料、二乙醇胺作稳定剂,加入聚乙二醇(PEG)作模板制备前驱体溶胶,通过溶胶-凝胶工艺和浸渍提拉技术在玻璃基片上制备了孔径在10~1000nm范围内可调的纳米TiO2多孔薄膜.通过ESEM,AFM,UV-VIS,N2吸附,XPS和XRD等测试手段研究了PEG(1000)的加入量对薄膜结构及性能的影响.结果表明,当100mL溶胶中PEG的加入量在4.0g左右时,可以得到三维扩展的多孔结构,孔的形状规则且分布均匀,孔径为200~500nm,薄膜比表面积可达76.1m2/g,而过多的PEG加入量反而导致薄膜性能下降. 相似文献
5.
聚乙二醇含量对纳米TiO2多孔薄膜性质的影响 总被引:7,自引:0,他引:7
以钛酸丁酯为无机原料、二乙醇胺作稳定剂,加入聚乙二醇(PEG)作模板制备前驱体溶胶,通过溶胶-凝胶工艺和浸渍提拉技术在玻璃基片上制备了孔径在10~1000nm范围内可调的纳米TiO2多孔薄膜.通过ESEM,AFM,UV-VIS,N2吸附,XPS和XRD等测试手段研究了PEG(1000)的加入量对薄膜结构及性能的影响.结果表明,当100mL溶胶中PEG的加入量在4.0g左右时,可以得到三维扩展的多孔结构,孔的形状规则且分布均匀,孔径为200~500nm,薄膜比表面积可达76.1m2/g,而过多的PEG加入量反而导致薄膜性能下降. 相似文献
6.
《Components and Packaging Technologies, IEEE Transactions on》2008,31(4):776-781
7.
通过调节微合金元素的含量获得3种具有不同力学性能的银键合丝.利用拉伸试验、键合试验、焊线挑断力、焊球推力测试等手段,研究了银键合丝力学性能对键合质量的影响.结果表明,在延伸率相同的条件下,随着微合金元素含量的降低,3种键合丝的断裂负荷降低,初始模量先减小后增大,键合后焊线挑断力和焊球推力均降低,电极金挤出率先减小后增大.银键合丝初始模量较低时在超声和压力的作用下易于变形,焊线内残余应力较低且第二焊点与引线框架结合较好,因此挑断测试时第二焊点与框架材料界面处不易发生脱离,有利于获得更高的键合成功率. 相似文献
8.
以钛酸丁酯为原料,在水热过程中加入聚乙二醇(分子量2 000)合成TiO2纳米晶,并制备多孔薄膜用于染料敏化太阳能电池(DSSCs)。采用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、台阶仪、紫外-可见分光光度计(UV-vis)对纳米晶粒的晶体结构、薄膜的表面形貌、厚度和光学吸收性能以及电池的光电能量转换性能随聚乙二醇的加入量变化的规律进行了探索。结果表明,聚乙二醇的加入抑制了锐钛矿相TiO2晶粒的生长,诱导了金红石相的形成。当聚乙二醇的加入量为TiO2质量的5%时性能达到最佳,采用单层多孔薄膜以及不添加四-叔丁基吡啶的电解质组装的电池获得了2.86%的光电能量转换效率。 相似文献
9.
Cu-Cu joints bonded by nano-copper pastes with different amounts of phenolic resin were developed at a low temperature (240°C) and a low pressure (1 MPa). The shear strengths of the joints were measured and the bonding layers were observed by scanning electron microscopy. The electrical conductivity of the joints was tested by a parameter analyzer. The results indicated that 2% phenolic resin in the pastes doubled the shear strength of Cu-Cu joints compared to joints made with 0%, 5% and 8% phenolic, because it filled the voids and coated sintered Cu nanoparticles in the joints without affecting the electrical conductivity of the Cu-Cu joint. This was because 2% phenolic paste prevented Cu nanoparticles from oxidation. However, 8% phenolic resin led to an increase of electrical resistivity due to the insulating property of phenolic resin, and a decrease of shear strength due to the hindrance to sintering between the nanoparticles. 相似文献
10.
11.
Sn3.5Ag4Ti(Ce,Ga) active filler was used for joining alumina with alumina and alumina with copper at 250°C in air. The joining
process was done without flux and without the need for pre-metallization of alumina or a protective atmosphere. After mechanical
activation of the bonding surfaces of alumina and copper, the filler showed good wetting on both alumina and copper and led
to a strong bond between alumina and copper. Through tensile testing, a bonding strength of 23.7 MPa was found in the alumina/copper
joint region. The shear strengths for alumina/alumina, copper/copper and alumina/copper joints were 13.5, 14.3, and 10.2 MPa,
respectively. The affinity of cerium for oxygen protects titanium from oxidation, giving rise to the reaction of titanium
with alumina at such a low temperature. Electron probe microanalyzer (EPMA) elemental mapping revealed that titanium segregates
effectively at the alumina/solder interfaces. After aging tests at 200°C and 150°C, a double layer of Cu3Sn and Cu6Sn5 intermetallic compound was formed at the solder/copper interfaces. With an increase of aging periods, the amount of brittle
compound in the joints increased and resulted in decreases in the shear strengths of the alumina/copper joints. 相似文献
12.
13.
14.
Keita Motoyama Tomoki Matsuda Tomokazu Sano Akio Hirose 《Journal of Electronic Materials》2018,47(10):5780-5787
Bonding between AlN and metals conventionally requires a surface modification process at high temperature such as metallization. The AlN-to-metal direct bonding process by sintering of Ag nanoparticles derived from in situ reduction of Ag2O microparticles mixed with diethylene glycol is examined. Bonding was conducted at 300–500 °C after a preheating process at 100 °C, and the shear strength exceeded 20 MPa for the joint bonded at 500 °C. The role of preheating in the direct bonding of AlN and Ag was identified. The Ag nanoparticles generated during preheating at 100 °C cover the AlN surface, and they are converted into a thin Ag film. The thin film promotes the formation of a bonding layer, owing to the effective adhesion of the sintered Ag to the film, and contributes to the bonding of Ag and AlN. No interfacial reaction layer is observed. The same bonding process can be applied to other ceramics with poor wettability. 相似文献
15.
Chip to chip bonding techniques using Cu bumps capped with thin solder layers have been frequently applied to 3D chip stacking technology. We studied the effect of joint microstructure on shear strength. Joints were formed by joining Sn/Cu bumps on a Si die and Sn/Cu layers on another Si die at 245–330°C using a thermo-compression bonder. Three different types of microstructures were fabricated in the joints by controlling the bonding temperature and time, (1) a Sn-rich phase with a Cu6Sn5 phase at the Cu interfaces, (2) a Cu6Sn5 phase in the interior with a Cu3Sn phase at the Cu interfaces, and (3) one single Cu3Sn phase throughout the whole joint. The joint having a single Cu3Sn phase had the highest shear strength. Specimens were aged up to 2000 h at 150°C and 180°C. During aging, the microstructures of all joints were transformed in a single Cu3Sn phase. The shear strength of the joints was very sensitive to the formation of Cu3Sn and microvoids. Microvoids formed in the solder joints with a Cu6Sn5 phase with and without a Sn-rich phase during aging and decreased the shear strength of the joints. Conversely, aging did not induce the formation of microvoids in the joints which originally had only a Cu3Sn phase and the shear strength was not decreased. 相似文献
16.
作为引线键合工艺中传统的焊接材料,金线在稳定性、导电性及价格等方面存在诸多局限,使得铜线焊技术在IC封装领域得到越来越广泛的应用。同时,由于铜线易氧化、硬度高,焊接能力较低,特别是二焊点容易出现拉力不够、开裂等缺陷,使得铜线焊的应用受到限制。针对传统工艺流程,提出Multi-stage方法,并在此基础上实现二焊点的double stitch工艺方法,通过试验证明该方法能够有效提高二焊点拉力,增强焊接强度。 相似文献
17.
本文采用数值模拟的方法研究了铜丝球键合技术中的形球过程。通过对超细铜丝在微电弧作用下形球过程中的温度场、速度场和位移场的计算,阐明了铜丝球形成的规律.文中对位移场的计算结果进行了实验验证。 相似文献
18.
Growth of Intermetallic Compounds in Thermosonic Copper Wire Bonding on Aluminum Metallization 总被引:1,自引:0,他引:1
Hui Xu Changqing Liu Vadim V. Silberschmidt Zhong Chen 《Journal of Electronic Materials》2010,39(1):124-131
Interface evolution caused by thermal aging under different temperatures and durations was investigated by means of scanning
electron microscopy (SEM) and transmission electron microscopy (TEM). It was found that approximately 30-nm-thick and discontinuous
Cu-Al intermetallic compounds (IMCs) were present in the initial bonds before aging. Cu-Al IMCs grew under thermal aging with
increasing aging time. The growth kinetics of the Cu-Al IMCs was correlated to the diffusion process during aging; their combined
activation energy was estimated to be 1.01 eV. Initially, Al-rich Cu-Al IMCs formed in the as-bonded state and early stage
of aging treatment. Cu9Al4 was identified by selected-area electron diffraction (SAD) as the only type of Cu-Al IMC present after thermal aging at 250°C
for 100 h; this is attributed to the relatively short supply of aluminum to the interfacial reaction. 相似文献
19.
Byunghoon Lee Jongseo Park Junghyun Song Kee-won Kwon Hoo-jeong Lee 《Journal of Electronic Materials》2011,40(3):324-329
This study reports the effects of bonding conditions (temperature and pressure) on the bonding morphology and electrical resistance
of a Cu/Sn/Cu structure. By carefully characterizing the bond using several analytical methods [scanning electron microscopy
(SEM), electron probe microanalysis (EPMA), and transmission electron microscopy (TEM)], we have learned that bonding the
samples under various conditions produces greatly different bond morphologies, as well as different prevailing phases in the
bonded layer. However, measurements of the electrical resistance of the joints reveal a relative insensitivity to the bonding
conditions, signaling that the microstructural evolution and the bond morphology do not strongly influence the resistance. 相似文献