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2008 33rd IEEE/CPMT International Electronics Manufacturing Technology Conference (IEMT)最新文献

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A study of the process time effect to photosensitive polyimides 工艺时间对光敏聚酰亚胺的影响研究
K. H. Ang, K. Cheong, Azmi Abdul Malik, Siew Lang Lee, G. Omar, S. Lim, C. L. Lim, Danny Tan, Michael B C Khoo
Polyimides are used extensively in the semiconductor industry as passivation layers, interlayers and dielectrics because of their excellent properties. These properties include thermal stability, superior chemical resistance, high mechanical strength and low dielectric constant. Most polyimide used in the semiconductor industry is the negative-type photosensitive polyimide due to its direct patternability. The purpose of this paper is to study the effect of process time delay during the polyamic ester formation to the final imidized polyimide. Post Coat Delay (PCD) is the delay time after coating before undergoing exposing while Post Expose Delay (PED) is the delay time after exposing before undergoing development. Samples of imide coated on bare wafers with after cure thickness of 6 Em are used. The image from Microscope inspection shows that the sample that is processed immediately is different from those other samples. The results of the after cure thickness of polyimides show that all the samples are within specification limit. Fourier Transform Infra Red (FTIR) is used to check for the chemical bonding. All the samples are fully imidized without peaks indicating the existence of PAE precursor. The imidization rate is lower as the delay time increase for both PCD and PED. Further investigation need to be done to verified the results.
聚酰亚胺因其优异的性能在半导体工业中广泛用作钝化层、中间层和介电材料。这些性能包括热稳定性,优异的耐化学性,高机械强度和低介电常数。半导体工业中使用的大多数聚酰亚胺是负型光敏聚酰亚胺,因为它具有直接的图案性。本文的目的是研究聚酰亚胺酯形成过程中工艺时间延迟对最终亚胺化聚酰亚胺的影响。涂层后延迟(PCD)是涂层后在进行曝光前的延迟时间,而曝光后延迟(PED)是曝光后在进行显影前的延迟时间。在裸晶圆上涂覆亚胺样品,固化后厚度为6em。显微镜检查的图像显示,立即处理的样品与其他样品不同。固化后的聚酰亚胺厚度测试结果表明,所有样品的固化后厚度均在规范范围内。傅里叶变换红外(FTIR)用于检查化学键。所有样品都是完全酰化的,没有峰表明PAE前驱体的存在。对于PCD和PED,随着延迟时间的增加,其亚化率都较低。需要进行进一步调查以核实结果。
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引用次数: 0
WLCSP and Flip Chip bumping technologies WLCSP和倒装芯片碰撞技术
A. Strandjord, T. Teutsch, A. Scheffler, T. Oppert, G. Azdasht, E. Zakel
WLCSP bumps have traditionally been produced by dropping preformed solder spheres through a metal template onto silicon wafers using modified surface mount stencil printers. The squeegee blades associated with these printers have been retrofitted with a special fixture in which spheres are gravity feed down through a narrow slot. This same stencil printer is often used to apply the flux to the wafer just prior to sphere dropping. This technique is applicable for many applications but there are several issues are associated with this technology that limit its widespread use in high volume and high yield applications. These limitations include: 1) there is a practical lower limit to the size of sphere that can be dropped, 2) the seal between the slotted fixturing and the wafer can fail, causing a release of all the spheres into the tool (often referred to as bursts or escapes), and 3) the yields are statistically low. Flip Chip bumps have traditionally been produced by electroplating or paste printing processes. Both technologies have been implemented in high volumes for PdSn bumping at many facility across the world. The electroplating technique is somewhat limited for use in smaller facilities due to the high capital and operation costs. In addition, ternary alloys, like SnAgCu are difficult to plate with consistent results. There is also a practical upper limit to the size of the bump that can be produced, and most applications rare for fine pitch bumping.. The paste printing technologies are very versatile with respect to the alloy composition that can be use, but is limited to pitches around 200μm for 100μm tall bumps. One new WLCSP technology that is showing high promise toward eliminating these limitations for both WLCSp and Flip Chip, is Wafer Level Solder Sphere Transfer (also called Gang Ball Placement). This technology uses a patterned vacuum plate to simultaneous pick up all of the preformed solder spheres, optically inspect for yield, and then transfer them over to the wafer. This paper will discuss this technology and the process parameters for producing WLCSP bumps. Throughput levels of 25 to 30 wafers per hour were measured. Yield losses of less than 10ppm were realized for placing 300μm spheres onto 200mm wafers with ~80,000 I/Os. Similar yields have been observed for placing 60μm flip chip sized spheres onto semiconductor wafers.
传统上,WLCSP凸起是通过使用改良的表面贴装模板打印机将预成型的焊锡球通过金属模板滴到硅片上来生产的。与这些打印机相关的刮墨刀已经改装了一个特殊的固定装置,在这个固定装置中,球体通过一个狭窄的槽被重力送入。同样的模板打印机通常用于在球体滴下之前将助焊剂涂在晶圆片上。该技术适用于许多应用,但与该技术相关的几个问题限制了其在大批量和高产量应用中的广泛应用。这些限制包括:1)可以掉落的球体尺寸有一个实际的下限;2)开槽夹具和晶圆之间的密封可能失效,导致所有球体释放到工具中(通常称为爆裂或逃逸);3)产量在统计上很低。倒装芯片的凸起传统上是通过电镀或粘贴印刷工艺生产的。这两种技术已经在世界各地的许多工厂大量应用于PdSn碰撞。由于高昂的资金和运营成本,电镀技术在较小的设施中使用有些限制。此外,像SnAgCu这样的三元合金很难得到一致的结果。也有一个实际的上限,以碰撞的大小,可以产生,和大多数应用罕见的小间距碰撞。粘贴打印技术在合金成分方面非常通用,但对于100μm高的凸起,其间距限制在200μm左右。一项新的WLCSP技术有望消除WLCSP和倒装芯片的这些限制,这就是晶圆级焊料球体转移(也称为Gang Ball Placement)。该技术使用带图案的真空板同时拾取所有预制焊锡球,光学检查产量,然后将其转移到晶圆上。本文将讨论该工艺及生产WLCSP凸点的工艺参数。测量了每小时25到30片晶圆的吞吐量水平。将300μm球体放置在200mm晶圆上,约80000个I/ o,产率损失小于10ppm。在半导体晶圆上放置60μm倒装芯片大小的球体也观察到类似的产量。
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引用次数: 2
Reduction of warpage occurrence on stack-die QFN using FEA and statistical method 利用有限元和统计方法减少叠模QFN的翘曲现象
I. Abdullah, I. Ahmad, M. Talib, M. N. Kamarudin
Warpage is greatly affected by package geometries, such as dimension of matrix array, pad, die and passive components as well as molding compound properties. It is also related to thermal mismatch i.e. coefficient of thermal expansion (CTE) and reliability of passive components in the package. So in order to reduce warpage occurrence in all packages, it is proposed that the combination of CTE properties of QFN packages layer need to be optimized. This study used finite element method (FEM) to perform extensive structural analysis of QFN package designs with respect to different combination of thermal properties and the possible occurrence of warpage. The results obtained were then verified with experimental data. The FEA method was able to simulate the warpage occurrence and the statistical method was able to identify the optimal combination of thermal properties of the layers. It was also found that the optimum combination of CTE properties will reduce the probability of the warpage occurrence.
翘曲受封装几何形状的影响很大,如矩阵阵列、衬垫、模具和无源元件的尺寸以及成型复合材料的性能。它还与热失配有关,即热膨胀系数(CTE)和封装中无源元件的可靠性。因此,为了减少所有封装中翘曲的发生,提出需要对QFN封装层的CTE特性组合进行优化。本研究采用有限元法(FEM)对QFN封装设计进行了广泛的结构分析,考虑了不同的热性能组合和可能发生翘曲的情况。用实验数据对所得结果进行了验证。有限元法能够模拟翘曲的发生,统计方法能够确定层间热性能的最佳组合。研究还发现,CTE性能的最佳组合可以降低翘曲发生的概率。
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引用次数: 3
Failure analysis for Copper Wire Bonding process from machine perspective 从机械角度分析铜线粘接工艺的失效
Hasnida Abdul Samat, S. Kamaruddin, Ishak Abd Azid
In fast changing and very competitive industry like semiconductor manufacturing, reliability or probability of failure always has been a crucial part in any processes and operation involving machine and equipment. One of many electronic manufacturing technologies is Wire Bond process, which entails a flexible and an accurate technology because of fast changing market demand for smaller electronic gadgets. Nature of wire bond process which is very delicate, usually makes any failures happen during this type of operation goes unnoticed for sometimes and this situation will cost the company a fortune. This paper aims to discuss equipment reliability based on failure occurrences in wire bond process using copper wire. Copper bonding has received attention because of its low cost, high electrical conductivity and resistance to wire sweep during plastic encapsulation. However, copper have hard properties thus more care is required during bonding as to avoid cratering problem. With the situation, this paper was written to find and analyze machine failure using Failure Mode and Effect Analysis (FMEA) technique to verify machine capability and problems faced when operating using Copper wire. Furthermore, general approach for improvement plan based on type of failure and failure causes are presented as conducted in a semiconductor company in Malaysia. The finding of the study provides evidence that failure analysis is an important task to be done in order to understand machine capability and reliability.
在像半导体制造业这样快速变化和竞争激烈的行业中,可靠性或故障概率一直是涉及机器和设备的任何过程和操作的关键部分。电线键合工艺是众多电子制造技术之一,由于市场对小型电子产品的需求快速变化,因此需要灵活而精确的技术。钢丝粘合过程的性质非常微妙,通常在这种类型的操作中发生的任何故障有时都不会被注意到,这种情况会使公司损失一大笔钱。本文的目的是根据铜线焊线过程中出现的故障来讨论设备的可靠性。铜键合因其成本低、电导率高、耐塑料封装过程中的导线扫线等优点而受到人们的关注。然而,铜具有较硬的性质,因此在连接过程中需要更加小心,以避免出现凹坑问题。针对这种情况,本文采用故障模式与影响分析(failure Mode and Effect Analysis, FMEA)技术对机器故障进行发现和分析,验证机器在使用铜线操作时的能力和面临的问题。此外,提出了在马来西亚一家半导体公司进行的基于故障类型和故障原因的改进计划的一般方法。研究结果表明,故障分析是了解机械性能和可靠性的一项重要工作。
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引用次数: 3
Effect of surface finish metallurgy on intermetallic compounds during soldering with tin-silver-copper solders 表面处理冶金对锡银铜焊料焊接过程中金属间化合物的影响
A. Ourdjini, M. A. Azmah Hanim, I. Aisha, Y. T. Chin
Solder joint reliability is dependent on both thickness and morphology of the intermetallics that form and grow at the solder joint interface during soldering and subsequent thermal ageing and examining the morphology of these intermetallics is of great importance. The focus of this paper is to present experimental results of a comprehensive study of the interfacial reactions during soldering of Sn-Ag-Cu lead-free solders on copper (Cu), immersion silver (ImAg), electroless nickel/ immersion gold (ENIG) and electroless nickel/ electroless palladium/ immersion gold (ENEPIG) surface finishes. Using scanning electron microscopy detailed a study of the 3-D morphology and grain size of the intermetallics was conducted. The results showed that when soldering on ENIG and ENEPIG finishes several morphologies of intermetallics with different grain sizes form at the solder joint interface compared to a single intermetallic morphology that forms when soldering on copper and immersion silver. An attempt was made to discuss the effect of several factors that may have an influence on the type of morphology the intermetallics may grow into. The results obtained in the present investigation also revealed that the technique of removing the solder by deep etching to examine the morphology of intermetallics is a convenient and efficient method to investigate the intermetallics formed at the solder joints.
焊点的可靠性取决于在焊接和随后的热时效过程中在焊点界面形成和生长的金属间化合物的厚度和形态,检查这些金属间化合物的形态非常重要。本文的重点是综合研究Sn-Ag-Cu无铅焊料在铜(Cu)、浸银(ImAg)、化学镍/浸金(ENIG)和化学镍/化学钯/浸金(ENEPIG)表面表面焊接时的界面反应的实验结果。利用扫描电镜对金属间化合物的三维形貌和晶粒尺寸进行了详细的研究。结果表明,在ENIG和ENEPIG表面焊接时,焊点界面形成了多种不同晶粒尺寸的金属间化合物形态,而在铜和浸银表面焊接时形成了单一的金属间化合物形态。本文试图讨论影响金属间化合物可能形成的形态类型的几个因素的影响。研究结果还表明,用深度刻蚀法去除焊料来检测金属间化合物的形貌是一种方便有效的研究焊点处金属间化合物形成的方法。
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引用次数: 6
Characteristic of low temperature of Bi-In-Sn solder alloy Bi-In-Sn钎料合金的低温特性
Ervina Efzan Mhd Noor, A. B. Ismail, N. M. Sharif, T. Ariga, Zuhailawati Hussain
Due to the increase in the use of electronics devices within the industry, the usage of solder connections has increased. These is a concern that lead within the electronic products is considered toxic because lead has potential for leaching from landfills onto water sources and becoming a hazard to human health and surrounding environment. For this reason, replacing Sn-37Pb to free solder with low melting temperature is one of the most important issues in electronic industry. This is due to a demand on low temperature for interconnection and polymer based part component such as LCD display functionality availability at low temperature apply. In this paper, Bi-In-Sn system alloy was investigated as a potential candidate replacing Sn-37Pb. This study covers on solder characteristic such as melting temperature, thermal expansion and microstructure. Bi-In-Sn was prepared and melted in crucible. Solder was cleaned mechanical and chemical before characterized. DSC shows that, Bi-In-Sn system alloy give low melting temperature in range of 65-100°C. The addition of In to Bi-Sn system alloy lowered the melting temperature compared than Sn-37Pb. Lowest melting temperature ensures that the solder melts, forms a joint with the substrates, and re-solidifies within the shortest possible process time. From thermal expansion analysis, it was found that Bi-In-Sn gives good expansion properties to avoid mismatch between Cu pads and solder itself. EDX analysis indicated that, there are two obvious regions in Bi-In-Sn system alloy microstructure. Bright colour refers to BiIn rich phase region and dark colour refers to Sn rich phase region. BiIn rich phase region is higher compared to Sn rich phase in solder give good properties in terms of ductility.
由于行业内电子设备的使用增加,焊料连接的使用也增加了。令人关注的是,电子产品中的铅被认为是有毒的,因为铅有可能从垃圾填埋场浸出到水源中,对人类健康和周围环境构成危害。因此,将Sn-37Pb替换为低熔化温度的游离焊料是电子工业中最重要的问题之一。这是由于对低温互连和基于聚合物的部件组件的需求,例如LCD显示功能在低温下的可用性。本文研究了Bi-In-Sn系合金作为替代Sn-37Pb的潜在候选材料。本研究涵盖焊料的特性,如熔化温度、热膨胀和微观结构。制备了Bi-In-Sn并在坩埚中熔化。焊料在进行表征前进行了机械和化学清洗。DSC表明,Bi-In-Sn系合金的熔点较低,在65 ~ 100℃范围内。与Sn-37Pb相比,添加In降低了Bi-Sn系合金的熔化温度。最低熔化温度确保焊料熔化,与基板形成连接,并在最短的工艺时间内重新固化。从热膨胀分析中发现,Bi-In-Sn具有良好的膨胀性能,避免了铜焊盘与焊料本身的失配。EDX分析表明,Bi-In-Sn系合金组织中存在两个明显的区域。颜色亮的为富BiIn相区,颜色暗的为富Sn相区。焊料中富铋相区比富锡相区高,具有良好的延展性。
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引用次数: 8
Improvement on coined solder surface on organic substrate for flip chip attach yield improvement 用于倒装芯片贴片成品率提高的有机基板上铸造焊料表面的改进
W. S. Ooi, Azlina Nayan, D. Ding, R. Newman, X. Zhao, S. Parthasarathy
This paper describes the improvement on coined solder surface of organic substrate to reduce flip chip assembly defects namely chip misalignment and contact non-wet. Roughening of the eutectic solder surface of the substrate helped to reduce bump misalignment for all packages especially for the tight bump pitch package. Additional pin reflow process for land grid array (LGA) substrates had proven to eliminate contact non wet issue. The surface morphology of the eutectic Sn/Pb bumps in the evaluations is characterized by Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM) and X-ray Photoelectron Spectroscopy (XPS). The condition of the solder joint is confirmed by chip pull test, x-ray and electrical test, using open/short test program.
本文介绍了对有机基板焊料表面的改进,以减少倒装芯片组装缺陷,即芯片错位和接触不湿。基板共晶焊料表面的粗化有助于减少所有封装的凹凸不平对中,特别是对于紧凸间距封装。陆地网格阵列(LGA)衬底的附加引脚回流工艺已被证明可以消除接触非湿问题。利用扫描电镜(SEM)、原子力显微镜(AFM)和x射线光电子能谱(XPS)对评价中Sn/Pb共晶凸起的表面形貌进行了表征。采用开/短试验程序,通过拉片试验、x射线试验和电气试验确认焊点状况。
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引用次数: 0
The next generation of quick turn method for interfacial strength testing: High Speed Ball Shear 下一代界面强度测试的快速转弯方法:高速球剪
Chee Kan Lee, R. Derek, W. K. Loh, Hui Ping Ng, K. W. Lau
In High Volume Manufacturing (HVM) environment, maintaining assembly process stability is the outmost priority to meet quality and reliability requirement. In recent years of transitioning to Lead Free (LF) solder alloy, tighter ball pitch and increasing hostile use condition, thus the expectation of better and tighter control in Solder Joint Reliability (SJR) is increasing. The SJR concern is not a new phenomenon, numerous research works are published to share the learning and options to resolve SJR issues including introduction of new solder alloy, Stress Compensation Layer (SCL), alternate surface finish and etc. The implementations of LF solder alloy have been found to be more at risk to brittle failure in the intermetallic layers. In view of the Flip Chip (FC) design requirement expands and evolves, it is important that the test metrology should likewise continue to evolve. The High Speed Ball Shear (HSBS) and conventional Cold Ball Pull (CBP) results are compared and discussed in term of the ability to predict susceptibility to interfacial failures due to assembly process changes for Flip Chip Ball Grid Array (FCBGA) packages. Examples of assembly process studies are Ball Attach (BA) reflow profile, effect of multiple reflows on the growth of intermetallic that affects the strength of solder joint performance, substrate plating process skew and etc. In additional, detailed microscopic analysis on post HSBS was executed to study the distribution and thickness of Intermetallic compound (IMC) layer on solder pad for FCBGA packages. The result showed that a higher sensitivity was demonstrated by HSBS as compare to CBP in assembly process shifts detection. This paper also covers the course of the development of fracture energy metric and implementations of HSBS metrology into HVM environment as an in line BA process monitoring system. Lastly, a comparison of the facture energy between ENIG and improve surface plating is provided to show the margin gained by improve surface plating technologies.
在大批量制造(HVM)环境下,保持装配过程的稳定性是满足质量和可靠性要求的重中之重。近年来,随着向无铅(LF)钎料合金的过渡,球距越来越紧,使用条件越来越恶劣,人们对焊点可靠性(SJR)的控制越来越严格。对SJR的关注并不是一个新现象,许多研究成果已经发表,以分享解决SJR问题的经验和选择,包括引入新的焊料合金,应力补偿层(SCL),替代表面处理等。在金属间层中,LF焊料合金的实现更容易发生脆性失效。鉴于倒装芯片(FC)设计需求的扩展和发展,测试计量也应该继续发展,这一点很重要。对高速球剪切(HSBS)和常规冷球拉(CBP)的结果进行了比较和讨论,以预测倒装芯片球栅阵列(FCBGA)封装的组装工艺变化对界面失效的敏感性。装配工艺研究的例子有:球附加(BA)回流曲线、多次回流对影响焊点性能强度的金属间生长的影响、衬底电镀工艺倾斜等。此外,对FCBGA封装焊盘上金属间化合物(IMC)层的分布和厚度进行了详细的HSBS微观分析。结果表明,HSBS在装配过程位移检测中比CBP具有更高的灵敏度。本文还介绍了断裂能测量的发展过程,以及HSBS测量作为在线BA过程监控系统在HVM环境中的实现。最后,比较了ENIG和改进表面镀工艺的加工能量,显示了改进表面镀工艺所获得的余量。
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引用次数: 0
Electrical characterization of through silicon via (TSV) for high-speed memory application 高速存储器用硅通孔(TSV)的电学特性
T. Hsu, K. Chiang, J. Lai, Yu-Po Wang
In this paper, we study three types of the interconnection between die and die for system-in-package (SIP). The first is the two-dimensional system-in-package (2-D SIP) which is side-by-side dies with wire bonding interconnection. The second is the three-dimensional system-in-package (3-D SIP) which stacks up two dies with wire bonding interconnection and the third is 3-D SIP with TSV interconnection. The propagation delay, insertion loss and return loss results will be compared among these three types interconnection. TSV interconnection shows the best performance among the three types due to its shortest interconnection path between die to die. We also study electrical characteristics of different TSV structure, like TSV size, TSV height, TSV pitch and the number of TSV stacked. Based on the analysis results, we will provide the design guideline for designer reference.
本文研究了系统级封装(system-in-package, SIP)中三种类型的模与模之间的互连。第一个是二维系统级封装(2-D SIP),它是采用线键合互连的并排封装。第二种是三维系统级封装(3-D SIP),它将两个芯片堆叠在一起,采用线键合互连;第三种是3-D SIP,采用TSV互连。对这三种互连方式的传播延迟、插入损耗和回波损耗结果进行比较。TSV互连在三种类型中表现出最好的性能,因为其芯片之间的互连路径最短。我们还研究了不同TSV结构的电特性,如TSV尺寸、TSV高度、TSV间距和TSV堆叠数。根据分析结果,提供设计指南供设计师参考。
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引用次数: 6
Nano silica dispersion in epoxy : the investigation of heat, milling speed and duration effect 纳米二氧化硅在环氧树脂中的分散:热、铣削速度和持续时间效应的研究
S. Ong, J. Ismail, M. Bakar, I. A. Rahman, C. S. Sipaut, C. Chee
Nano composites are a promising development but the challenge of homogenous and discrete dispersion of the nano fillers are barriers that must be overcome before they can be effectively implemented. Although the common dispersion methods such as particle surface modification, comprehensive milling metrologies and the usage of solvents bear results, these are time consuming and not cost effective. In this paper, we explore the efficiency of coupling the usage of ball-media and heat on the dispersion of nano silica in epoxy. No solvents are involved. The effects of milling speed and duration are also studied albeit under a fixed ball media : silica-epoxy volume ratio of 3:5. The experiment set-up involves a simple 3-blade mixer, round bottom flask and 60 ? m zirconia ball. At nano silica loading of 10 wt % the nano silica clusters are systematically reduced from 1.5 - 2 ? m to 100 - 200 nm with the usage of ball media and application of heat. At the optimum milling speed and duration of 500 rpm for 5 hours, the aggregate sizes were further reduced to 30 - 70 nm, which is almost a discrete dispersion.
纳米复合材料是一个很有前途的发展方向,但纳米填料的均匀性和分散性是其有效应用必须克服的障碍。虽然常见的分散方法,如颗粒表面改性、综合铣削计量和溶剂的使用都有效果,但这些都是耗时且不经济的。本文探讨了球介质与热耦合作用对纳米二氧化硅在环氧树脂中的分散效果。不涉及溶剂。在固定的球介质:硅-环氧体积比为3:5的情况下,也研究了铣削速度和持续时间的影响。实验装置包括一个简单的3叶片搅拌器,圆底烧瓶和60 ?M氧化锆球。在纳米二氧化硅负载为10 wt %时,纳米二氧化硅团簇系统地从1.5 - 2 ?M至100 - 200nm,使用球介质和加热。在最佳磨矿速度和500转/分的磨矿时间下,磨矿时间为5小时,骨料尺寸进一步减小到30 - 70 nm,几乎是离散的分散体。
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引用次数: 0
期刊
2008 33rd IEEE/CPMT International Electronics Manufacturing Technology Conference (IEMT)
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