共查询到20条相似文献,搜索用时 62 毫秒
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半导体封装对于芯片来说是必须的,也是至关重要的.封装可以指安装半导体集成电路芯片用的外壳,它不仅起着保护芯片和增强导热性能的作用,而且还起到沟通芯片内部世界与外部电路桥梁和规格通用功能的作用.文章阐述了铜线键合替代金线的优势,包括更低的成本、更低的电阻率、更慢的金属问渗透.再通过铜线的挑战--易氧化、铜线硬度大等,提出... 相似文献
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为满足铜线键合拉力试验需求,从拉力施加位置、失效模式分类、最小拉力值以及试验结果的应用等4个方面对国内外铜线键合拉力试验方法标准的技术内容进行对比分析,并提出国内试验方法的修订建议。 相似文献
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采用铜引线键合工艺生产的电子元器件在服役中会产生热,引起引线与金属化焊盘界面出现IMC(intermetallic compound,金属间化合物)。IMC的生长和分布将影响键合点的可靠性,严重时会出现"脱键",导致元器件失效。研究了焊点在服役过程中的演化,选取铜线键合产品SOT-23为试验样品,分析了在高温存储试验环境下焊点键合界面IMC的生长及微观结构变化情况。 相似文献
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半导体封装行业中铜线键合工艺的应用 总被引:1,自引:0,他引:1
文章介绍了半导体封装行业中铜线键合工艺下,各材料及工艺参数(如框架、劈刀、设备参数、芯片铝层与铜材的匹配选择)对键合质量的影响,并总结提出如何更好地使用铜线这一新材料的规范要求。应用表明芯片铝层厚度应选择在0.025mm以上;劈刀应使用表面较粗糙的;铜线在键合工艺中使用体积比为95:5的氢、氮气混合保护气体;引线框架镀银层厚度应控制在0.03mm~0.06mm。 相似文献
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对铜线键合的优缺点及分立器件的结构特点进行了具体分析。根据分析结果,并结合具体的实验,给出了键合工艺条件和工艺参数对分立器件铜线键合过程的影响。此研究对提高分立器件铜线键合产品的质量及可靠性具有重要意义。 相似文献
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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. 相似文献
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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. 相似文献
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The ultrasonic wire bonding (UWB) process has been examined using transmission electron microscopy (TEM) and standard wire
pull testing techniques. Al-0.5 wt.% Mg wires 75 μm in diameter were bonded to pure and alloyed Al substrates. The bonding
parameters, surface roughness, and surface contamination levels were variables in the experiments. Cross-section TEM specimens
were made from these samples. TEM analysis was conducted on the wire, wire/substrate interface and substrate. Pull tests showed
that for the Al substrates the surface roughness or the presence of contamination did not effect the bond strength, whereas
for contaminated stainless steel substrates, a three μm surface finish resulted in the highest bond pull strength. The TEM
observations revealed features such as low-angle grain boundaries, dislocation loops and the absence of a high dislocation
density, indicating that the wire and substrate were dynamically annealed during bonding. Based on the width of a zone near
a grain boundary in the wire which was depleted of dislocation loops, it was estimated that local heating equivalent to a
temperature of 250° C for 90 msec was achieved in the wire during bonding. No evidence was found for melting along the bond
interface, indicating that UWB is a solid-state process. Based on the TEM observationsof the bond interface and the pull tests, it is concluded that the ultrasonic vibrations clean the surfaces to be joined to
the extent that a good bond can be obtained by intimate metal-metal contact in the clean areas. 相似文献
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Development of a thermosonic wire-bonding process for gold wire bonding to copper pads using argon shielding 总被引:2,自引:0,他引:2
To improve the bondability and ensure the reliability of Au/Cu ball bonds of the thermosonic (TS) wire-bonding process, an
argon-shielding atmosphere was applied to prevent the copper pad from oxidizing. With argon shielding in the TS wire-bonding
process, 100% gold wire attached on a copper pad can be achieved at the bonding temperature of 180°C and above. The ball-shear
and wire-pull forces far exceed the minimum requirements specified in the related industrial codes. In a suitable range of
bonding parameters, increasing bonding parameters resulted in greater bonding strength. However, if bonding parameters exceed
the suitable range, the bonding strength is deteriorated. The reliability of the high-temperature storage (HTS) test for Au/Cu
ball bonds was verified in this study. The bonding strength of Au/Cu ball bonds increases slightly with prolonged storage
duration because of diffusion between the gold ball and copper pad during the HTS test. As a whole, argon shielding is a successful
way to ensure the Au/Cu ball bond in the TS wire-bonding process applied for packaging of chips with copper interconnects. 相似文献
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A copper pad oxidizes easily at elevated temperatures during thermosonic wire bonding for chips with copper interconnects.
The bondability and bonding strength of a gold wire onto a bare copper pad are seriously degraded by the formation of a copper
oxide film. A new bonding approach is proposed to overcome this intrinsic drawback of the copper pad. A silver layer is deposited
as a bonding layer on the surface of copper pads. Both the ball-shear force and the wire-pull force of a gold wire bonded
onto copper pads with silver bonding layers far exceed the minimum values stated in the JEDEC standard and MIL specifications.
The silver bonding layer improves bonding between the gold ball and copper pads. The reliability of gold ball bonds on a bond
pad is verified in a high-temperature storage (HTS) test. The bonding strength increases with the storage time and far exceeds
that required by the relevant industrial codes. The superior bondability and high strength after the HTS test were interpreted
with reference to the results of electron probe x-ray microanalyzer (EPMA) analysis. This use of a silver bonding layer may
make the fabrication of copper chips simpler than by other protective schemes. 相似文献
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Thermosonic bonding of gold wire onto a copper pad with titanium thin-film deposition 总被引:1,自引:0,他引:1
A novel thermosonic (TS) bonding process for gold wire bonded onto chips with copper interconnects was successfully developed
by depositing a thin, titanium passivation layer on a copper pad. The copper pad oxidizes easily at elevated temperature during
TS wire bonding. The bondability and bonding strength of the Au ball onto copper pads are significantly deteriorated if a
copper-oxide film exists. To overcome this intrinsic drawback of the copper pad, a titanium thin film was deposited onto the
copper pad to improve the bondability and bonding strength. The thickness of the titanium passivation layer is crucial to
bondability and bonding strength. An appropriate, titanium film thickness of 3.7 nm is proposed in this work. One hundred
percent bondability and high bonding strength was achieved. A thicker titanium film results in poor bond-ability and lower
bonding strength, because the thicker titanium film cannot be removed by an appropriate range of ultrasonic power during TS
bonding. The protective mechanism of the titanium passivation layer was interpreted by the results of field-emission Auger
electron spectroscopy (FEAES) and electron spectroscopy for chemical analysis (ESCA). Titanium dioxide (TiO2), formed during the die-saw and die-mount processes, plays an important role in preventing the copper pad from oxidizing.
Reliability of the high-temperature storage (HTS) test for a gold ball bonded on the copper pad with a 3.7-nm titanium passivation
layer was verified. The bonding strength did not degrade after prolonged storage at elevated temperature. This novel process
could be applied to chips with copper interconnect packaging in the TS wire-bonding process. 相似文献
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《Microelectronics Reliability》2014,54(11):2555-2563
Copper (Cu) wire bonding has become a mainstream IC assembly solution due to its significant cost savings over gold wire. However, concerns on corrosion susceptibility and package reliability have driven the industry to develop alternative materials. In recent years, palladium-coated copper (PdCu) wire has become widely used as it is believed to improve reliability. In this paper, we experimented with 0.6 ml PdCu and bare Cu wires. Palladium distribution and grain structure of the PdCu Free Air Ball (FAB) were investigated. It was observed that Electronic Flame Off (EFO) current and the cover gas type have a significant effect on palladium distribution in the FAB. The FAB hardness was measured and correlated to palladium distribution and grain structure. First bond process responses were characterized. The impact of palladium on wire bondability and wire bond intermetallic using a high temperature storage test was studied. 相似文献
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Two capillary solutions for ultra-fine-pitch wire bonding and insulated wire bonding 总被引:2,自引:0,他引:2
K.S. Goh 《Microelectronic Engineering》2007,84(2):362-367
In this article, the new challenges and requirements in wire bonding are discussed, the problems in ultra-fine-pitch wire bonding and insulated wire bonding are analyzed, and then two capillary solutions to the problems are presented. Actual bonding experiments using the new capillaries were carried out and the results were satisfactory. Compared to the standard design, a new capillary design has a larger inner chamfer, a larger chamfer diameter and a smaller chamfer angle. This new capillary design has proved to improve the ball bondability and smaller ball size control for ultra-fine pitch wire bonding. A unique surface characteristic on the capillary tip surface has also been derived. The new finishing process developed creates a new surface morphology, which has relatively deep lines with no fixed directions. Compared to the standard capillary, this capillary has less slipping between the wire and the capillary tip surface in contact, and provides better coupling effect between them and better ultrasonic energy transfer. This capillary has been used to effectively improve the bondability of the stitch bonds for insulated wire bonding. 相似文献
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Copper wires are increasingly used in place of gold wires for making bonded interconnections in microelectronics. In this paper, a microstructural study is reported of cross-sectioned free air balls (FABs) made with 23 μm diameter copper bonding wire. It was found that the FAB is comprised of a few columnar grains and a large number of fine subgrains formed within the columnar grains around the periphery of the FAB. It was determined that conduction through the wire was the dominant heat loss mechanism during cooling, and the solidification process started from the wire-ball interface and proceeded across the diameter then outward towards the ball periphery.The microstructure of the Cu ball bond after thermosonic bonding was investigated. The result showed that the subgrain orientations were changed in the bonding process. It is evident that metal flow along the bonding interface was from the central area to the bond periphery during thermosonic bonding. 相似文献