电子制造中的引线键合工艺(英文)

文章通过总结众多相关文献的研究成果和实际引线键合工艺中的经验心得,为读者呈现较全面的有关于引线键合的介绍,包括键合时序、机台动作、关键键合参数、键合材料特性、键合工具的设计、键合机理等方面。在对一些常见的工艺问题(如不烧球、高尔夫焊点、短线尾、焊点不粘等)分析的基础上,讨论其解决方案和最近研究进展;同时也关注了铜引线键合技术发展中存在的一些问题。由于作者能力及文章篇幅的限制,仅对关键工艺及因素进行了探讨,希望能帮助读者深入了解引线键合工艺,并对实际工艺问题的解决和键合理论机理的研究有所益处。     

Comparison of the copper and gold wire bonding processes for LED packaging

Wire bonding is one of the main processes of the LED packaging which provides electrical interconnection between the LED chip and lead frame. The gold wire bonding process has been widely used in LED packaging industry currently. However, due to the high cost of gold wire, copper wire bonding is a good substitute for the gold wire bonding which can lead to significant cost saving. In this paper, the copper and gold wire bonding processes on the high power LED chip are compared and analyzed with finite element simulation. This modeling work may provide guidelines for the parameter optimization of copper wire bonding process on the high power LED packaging.     

A One‐Kilobit PQR‐CMOS Smart Pixel Array

The photonic quantum ring (PQR) laser is a three dimensional whispering gallery (WG) mode laser and has anomalous quantum wire properties, such as microampere to nanoampere range threshold currents and √T‐dependent thermal red shifts. We observed uniform bottom emissions from a 1‐kb smart pixel chip of a 32×32 InGaAs PQR laser array flip‐chip bonded to a 0.35 µm CMOS‐based PQR laser driver. The PQR‐CMOS smart pixel array, now operating at 30 MHz, will be improved to the GHz frequency range through device and circuit optimization.     

Si/InP键合界面的研究

应用疏水处理方法成功实现了Si/InP的键合,然后通过对InP和Si的表面XPS能谱分析得到界面信息,从而了解键合机理.I-V曲线也反应了键合界面的性质,通过450、550℃退火样品的伏安特性可知道,对于InP/Si键合结构而言,退火温度与界面特性应该存在最佳值.     

用于监测硅片应力的红外光弹仪

为检测硅片在制造工艺中的应力变化,研制了可用于硅片应力检测/监测的红外光弹(IRPE)系统,获得了芯片的红外光弹图像.利用该系统得出了硅通孔(TSV)结构在退火过程中的应力变化,并发现虽然制造技术和工艺完全一样,但每个TSV的初始残余应力是不同的.不同的TSV取得零应力的温度点也不相同,然而当温度达到一定值时,所有TSV都将保持零应力状态.此外,该系统也用于晶圆键合质量的评价,相对于一般红外显微镜,其检测效果更佳,与超声法相比,其检测效果相当,但效率更高且不需耦合剂.     

基于K-SVD字典稀疏分解的实木地板去噪方法

针对实木地板的图像获取过程中,所产生的噪声问题,引入了K-SVD字典的学习算法,提出了一种图像的有用信息稀疏分解去噪的方法,目的是有效的保留实木地板的有用纹理信息,并抑制其中掺杂的噪声。通过对图像稀疏分解后得到的值,来进行图像重构,就可以达到图像的去噪目的。首先,构造一个初始化的DCT字典,对图像分块处理;接着,在这个初始化字典的基础之上,进行纹理信息的稀疏分解,同时,对它们之间的残差值进行奇异值分解,更新字典;最后,利用得出的最优化字典,采用正交匹配重构算法,完成去噪图像的重建。实验表明,该算法得出的图像主观效果好,减少了去噪后的模糊程度及保留更多细节信息,在不同程度的噪声下,PSNR较高。     

对影响内引线键合可靠性的因素的分析与对策

简述了半导体器件内引线键合的机制及如何检测内引线的键合质量, 分析了影响内引线键合质量的因素, 重点分析了半导体器件最常见的失效模式——键合点脱落的因素, 并提出改进键合质量的几点措施     

铌酸锂晶片的键合减薄及热释电性能研究

铌酸锂(LN)作为一种热释电材料,可以被用于制作光电探测器敏感单元的敏感层,但通常LN晶片厚度为0.5 mm,远大于光电敏感单元厚度的要求,所以需要用键合减薄及抛光技术对LN晶片进行加工处理。本研究所用键合减薄技术主要包含:RZJ-304光刻胶键合、铣磨、抛光、剥离液剥离和丙酮清洗RZJ-304胶。利用该技术加工得到了面积为10 mm×10 mm,厚度为50μm,表面比较光滑,表面粗糙度为1.63 nm的LN晶片。LN晶片的热释电信号峰峰值在减薄抛光后为176 mV,是未经处理时的4倍,满足了热释电探测器敏感层的要求。     

铜线键合Cu/Al界面金属间化合物微结构研究

由于铜线具有较高的热导率、卓越的电学性能以及较低的成本,被普遍认为将逐渐代替传统的金线而在IC封装的键合工艺中得到广泛的应用。铜线键合工艺中Cu/Al界面金属间化合物(IMC)与金线键合的Au/Al IMC生长情况有很大差别,本文针对球焊键合中键合点的Cu/Al界面,将金属间化合物生长理论与分析手段相结合,研究了Cu/Al界面IMC的生长行为及其微结构。文中采用SEM测试方法,观察了IMC的形貌特点,测量并得到了IMC厚度平方正比于热处理时间的关系,计算得到了生长速率和活化能数值,并采用TEM,EDS等测试手段,进一步研究了IMC界面的微结构、成分分布及其金相结构。     

Adhesion and Surface Interactions of a Self‐Healing Polymer with Multiple Hydrogen‐Bonding Groups

The surface properties and self‐adhesion mechanism of self‐healing poly(butyl acrylate) (PBA) copolymers containing comonomers with 2‐ureido‐4[1H]‐pyrimidinone quadruple hydrogen bonding groups (UPy) are investigated using a surface forces apparatus (SFA) coupled with a top‐view optical microscope. The surface energies of PBA–UPy4.0 and PBA–UPy7.2 (with mole percentages of UPy 4.0% and 7.2%, respectively) are estimated to be 45–56 mJ m^?2 under dry condition by contact angle measurements using a three probe liquid method and also by contact and adhesion mechanics tests, as compared to the reported literature value of 31–34 mJ m^?2 for PBA, an increase that is attributed to the strong UPy–UPy H‐bonding interactions. The adhesion strengths of PBA–UPy polymers depend on the UPy content, contact time, temperature and humidity level. Fractured PBA–UPy films can fully recover their self‐adhesion strength to 40, 81, and 100% in 10 s, 3 h, and 50 h, respectively, under almost zero external load. The fracture patterns (i.e., viscous fingers and highly “self‐organized” parallel stripe patterns) have implications for fabricating patterned surfaces in materials science and nanotechnology. These results provide new insights into the fundamental understanding of adhesive mechanisms of multiple hydrogen‐bonding polymers and development of novel self‐healing and stimuli‐responsive materials.