共查询到19条相似文献,搜索用时 53 毫秒
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GaN基大功率倒装焊蓝光LED的I-V特性研究 总被引:1,自引:0,他引:1
测量了GaN基大功率倒装焊蓝光发光二极管(LED)在不同温度、不同老化阶段的电流-电压(I-V)特性曲线.结果表明,相对理想情形,特性曲线的反向偏压区漏电因深能级隧穿偏大;正向小偏压下因沿着位错汇聚金属产生漏电流;产生-复合电流区和扩散电流区因多量子阱限制而理想因子偏大;由于有源区低掺杂,在10A/cm2就开始形成大注入区;在大电流下也因为串联电阻分压而形成串联电阻区.扩散电流区的温度系数和肖克莱方程导出的数值最接近,可用来测量结温.老化过程中反向漏电流增加,是因为有了更多被激活的深能级;随着老化正向漏电增加的速度变慢,是由于位错逐渐被汇集的金属填满. 相似文献
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金凸点热压超声倒装焊中涉及的主要工艺参数,如压力和超声功率,会随着I/O端数的改变产生较大差异。对具有不同数量I/O端的金凸点倒装焊工艺参数进行研究和优化,有助于透析产生差异的根源,指导实际生产。通过对I/O端数分别为121、225、361的金凸点倒装焊工艺参数进行研究,发现随着I/O端数量的增加,单位凸点上的最大平均剪切力依次减小,达到最大平均剪切力时所需单位凸点上的平均超声功率和平均压力依次减小。工艺窗口依次缩窄的主要原因是热压超声过程中传递的能量不均匀。在倒装焊工艺中,使用预倒装的方法可使各凸点在倒装焊中的能量分布更均匀,使用此方法对具有361个I/O端的芯片进行倒装焊,单位凸点上的平均剪切力达到了0.54 N,比未使用此方法时的平均剪切力(0.5 N)提高了8%。 相似文献
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Chun-Mei Li Ping Yang De-Ming Liu Ngar-Chun Hung Ming Li 《Journal of Electronic Materials》2007,36(5):587-592
Microstructures and microtextures of the gold wire, free air ball, Au stud bumps and flip chip bonding bumps were analyzed
using Electron Backscatter Diffraction (EBSD). It is demonstrated that process parameters, such as bonding power, force and
temperature have significant influences on the microstructure and microtexture of gold bumps. The non-uniform deformation,
the associated microstructure defects and the local textures of the Au bumps under the vertical force and the horizontal ultrasonic
wave applied are presented and discussed. 相似文献
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文章讨论了引线键合芯片与板上或有机基板上焊料凸点式倒装片的成本比较问题。核查了IC芯片效率、金丝与焊接材料及这些技术使用的主要设备对成本的影响。采用有用的公式和图表,确定成本,并比较了采用这些技术的成本状况。 相似文献
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芯片键合换能系统中接触界面的影响分析 总被引:1,自引:1,他引:0
接触界面对超声能量传递与振动特性的影响是各类压电换能器的共性问题。在超声芯片封装领域,各子部分之间的接触界面是影响系统超声能量传递的强非线性因素,直接影响芯片与基板的键合质量。该文通过有限元法与激光多谱勒测振仪等技术,获得系统中接触界面对超声能量传递与振动特性的影响规律,发现不合理的接触界面会引发系统多模态与频率混叠效应、超声能量输出不稳定、系统迟滞响应等,导致键合强度下降、芯片与基板倾斜、键合效率下降等封装缺陷。研究结果对理解超声键合与系统设计具有指导意义。 相似文献
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The latest three-dimensional (3D) chip-stacking technology requires the repeated stacking of additional layers without remelting
the joints that have been formed at lower levels of the stack. This can be achieved by transient liquid-phase (TLP) bonding
whereby intermetallic joints can be formed at a lower temperature and withstand subsequent higher-temperature processes. In
order to develop a robust low-temperature Au/In TLP bonding process during which all solder is transformed into intermetallic
compounds, we studied the Au/In reaction at different temperatures. It was shown that the formation kinetics of intermetallic
compounds is diffusion controlled, and that the activation energy of Au/In reaction is temperature dependent, being 0.46 eV
and 0.23 eV for temperatures above and below 150°C, respectively. Moreover, a thin Ti layer between Au and In was found to
be an effective diffusion barrier at low temperature, while it did not inhibit joint formation at elevated temperatures during
flip-chip bonding. This allowed us to control the intermetallic formation during the distinct stages of the TLP bonding process.
In addition, a minimal indium thickness of 0.5 μm is required in order to enable TLP bonding. Finally, Au/In TLP joints of ∅40 μm to 60 μm were successfully fabricated at 180°C with very small solder volume (1 μm thickness). 相似文献
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