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Solder Joint Degradation Analysis Using Time Domain Reflectometry

Solder Joint Degradation Analysis Using Time Domain Reflecto...

2011 International Conference on Quality,reliability,Risk,Maintenance,and Safety Engineering(2011年质量、可靠性、风险、维修性与安全性国际会议暨第二届维修工程国际学术会议 ICQR2MSE 2011)

作者： Ming WAN Yudong LU Jingdong FENG Xiaohan WANG Yunfei EN Bin YAO Xin WANG College of Materials Science and Engineering South China University of Technology Guangzhou China S College of Materials Science and Engineering South China University of Technology Guangzhou China S Science and Technology on Reliability Physics and Application of Electronic Component Laboratory The Key Laboratory of Specially Functional Materials College of Materials Science and Engineering Sout

Solder joints on the Printed-Circuit board (PCB) serve as mechanical and electrical connections. Their function maybe simple, but the reliability of the solder joints may affect the entire device or system. They are usually the weak links when the electronic products are exposed to a variety of load conditions from their operation and storage, such as temperature cycling, vibration, shock and humidity. One of the most important parameters of solder joints is electrical stability. The resistance or impedance will rise as the fracture spreads through the solder joints. The reliability of solder joints is often determined through continuous DC resistance measurement, but it not very sensitive. In recent years, Time Domain Reflectometry (TDR) technique has been found to be a better alternative that are required for monitoring the degradation of interconnects. At high frequencies, signal propagation is concentrated at the surface of interconnects, a phenomenon known as the skin effect. Degradation of interconnects, such as cracking of solder joints due to fatigue or shock loading, also usually initiates at the surface and propagates inward. Therefore, even a small crack at the surface of a solder joint may change RF impedance. A physical crack initiated at the surface of the solder joints results in the increase of RF impedance. Thus, the crack length should be correlative with RF impedance or Reflection Coefficient, and the failure time of the solder joint could be estimated in view of electronic theory and the theory of fracture. A mathematic model was proposed to predict the relationship between the time domain reflection coefficient of solder joint and the crack length in it.

关键词： Solder joint reliability Time domain reflect degradation

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Strain Tears the Phonon Band of Graphene

Strain Tears the Phonon Band of Graphene

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第三届亚洲光谱会议

作者： X.X.Yang J.W.Li Y.Wang Z.F.Zhou Chang Q.Sun Institute for Quantum Engineering and Micro-Nano Energy Technology Key Laboratory of Low-Dimensional Materials and Application Technologiesand Faculty of Materials and Optoelectronic PhysicsXiangtan University School of Information and Electronic Engineering Hunan University of Science and Technology School of Electrical and Electronic Engineering Nanyang Technological University

Theoretical[1]duplication of the measured Raman shifts of the monolayer graphene under the uniaxial strain has derived the effective force constant of 6.28 N/m of the C-C bond and clarifies that:i)the bond elongation ... 详细信息

关键词： Strain Tears the Phonon Band of Graphene

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Raman spectroscopic determination of the length,strength,compressibility,Debye temperature,elasticity,and force constant of the C-C bond in graphene

Raman spectroscopic determination of the length,strength,com...

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第三届亚洲光谱会议

作者： X.X.Yang J.W.Li Z.F.Zhou Y.Wang L.W.Yang W.T.Zheng Chang Q.Sun Institute for Quantum Engineering and Micro-Nano Energy Technology Key Laboratory of Low-Dimensional Materials and Application Technologiesand Faculty of Materials and Optoelectronic PhysicsXiangtan University School of Information and Electronic Engineering Hunan University of Science and Technology Department of materials Science Jilin University School of Electrical and Electronic Engineering Nanyang Technological University

From the perspective of bond relaxation and vibration,we have been able to reconcile the Raman shift of graphene under stimuli of the number-of-layer,the uniaxial-strain,the pressure,and the temperature in terms of th... 详细信息

关键词： Raman spectroscopic determination of the length,strength,compressibility,Debye temperature,elasticity,and force constant of the

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Multiple bit upsets mitigation in memory by using improved hamming codes and parity codes

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Journal of Harbin Institute of technology(New Series) 2010年第5期17卷 726-730页

作者：祝名肖立伊田欢 Microelectronics Center Harbin Institute of Technology National Key Laboratory of Science and Technology on Reliability Physics and Application Technology of Electrical Component

This paper combines improved Hamming codes and parity codes to assure the reliability of memory in presence of multiple bit upsets with low cost *** redundancy bits of improved Hamming codes will be appended at the end of data bits,which eliminates the overhead of interspersing the redundancy bits at the encoder and *** reliability of memory is further enhanced by the layout architecture of redundancy bits and data *** proposed scheme has been implemented in Verilog and synthesized using the Synopsys *** results reveal that the proposed method has about 19% less area penalties and 13% less power consumption comparing with the current two-dimensional error codes,and its latency of encoder and decoder is 63% less than that of Hamming codes.

关键词： memory multiple bit upsets improved hamming codes two-dimensional error codes

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Vibration Durability Modeling and Dynamic Response Analysis of PBGA Mixed Solder Joints

Vibration Durability Modeling and Dynamic Response Analysis ...

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11th International Conference on electronic Packaging technology and High Density Packaging (ICEPT-HDP)

作者： Zhou Bin Qiu Baojun En Yunfei CEPREI Natl. Key Lab of Sci. and Technology on Reliability Physics and Application of Electronic Component China

ISBN: (纸本)9781424481422

Along with more and more use of high density plastic ball grid array (PBGA) in portable electronic products and military electronic equipments, the vibration fatigue reliability of solder joints for PBGA becomes a critical concern. In this paper, a quarter 3D symmetric model was developed by ANSYS software, then modal analysis of PCBA assembly and random vibration response analysis of mixed solder joints were implemented. The effect of fixation points on mode shape and the size parameters for solder joints on von mises stress were discussed. Finally, the influence of every step mode on the PCB bending deflection was analyzed. The results showed that the first bend mode was the main factor which influences the bend deformation of the PCB. Adopting more fixations can reduce the influence of the first mode. Solder joint with maximum von mises stress (critical solder joint) was occurred on the outmost corner of PBGA which is mounted at the position of PCB largest deformation, and the accurate critical interface was located at the soldering interface between PCB and solder ball. More deflection of PCB causes larger stress of solder joint. The further research found that the first four step natural frequencies are less than 2000Hz, and they are within the vibration frequency range of 5Hz to 2000Hz caused by the transport and application. So it is necessary to optimize the fixation design of PCB assembly. Moreover, within a certain range, the thicker of PCB vehicle can get smaller stress, while the greater height of solder ball would cause greater stress.

关键词： PBGA Solder Joint Modal Analysis Vibration Response

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Main failure mechanism and preventive measures of plastic encapsulated MMIC

Main failure mechanism and preventive measures of plastic en...

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URSI International Symposium on Signals, Systems, and electronics (ISSSE)

作者： Li, Ping Chen, Yuan Science and Technology on Reliability Physics and Application of Electronic Component Laboratory Fifth Research Institute of MIIT Dong Guang Zhuang Road Number 110 Tian He District Guang Zhou China

According to collection and analysis of plastic encapsulated MMIC failure cases these years, the main failure mechanisms proportion was calculated statistically. And corresponding preventive measures against failure w... 详细信息

ISBN: (纸本)9781424463558

关键词： Failure (mechanical)

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Piezoelectric Properties of Nanocrystalline Barium Titanate Ceramics

Piezoelectric Properties of Nanocrystalline Barium Titanate ...

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The 11th International Workshop on Plasma-Based Ion Implantation & Deposition(第11届等离子基离子注入与沉积国际会议)

作者： Renbo Yang Xiangyun Deng Liren Han Yanjie Zhang Jia Liu Xiaolong Zhang Dejun Li Xiaohui Wang Longtu Li Key Laboratory of Ministry of Education for Application Technology of Chemical Materials in Hainan Superior Resources Hainan Provincial Key Laboratory of Research on Utilization of Si-Zr-Ti Resources Materials and Chemical Engineering Institute Hainan University Haikou People''s Republic of China Department of Materials Science and Engineering Tsinghua University Beijing People''s Republic of China College of Physics and Electronic Information Tianjin Normal University Tianjin People''s Republic of China College of Physics and Electronic Information Tianjin Normal University Tianjin People''s Republic of China

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Vibration durability modeling and dynamic response analysis of PBGA mixed solder joints

Vibration durability modeling and dynamic response analysis ...

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International Conference on (ICEPT) electronic Packaging technology

作者： Bin Zhou Baojun Qiu Yunfei En CEPREI National Key Lab of Science and Technology on Reliability Physics and Application of Electronic Component China

关键词： Soldering Vibrations Stress reliability Strain Finite element methods

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Publisher’s Note: “application of electron backscatter diffraction to the study on orientation distribution of intermetallic compounds at heterogeneous interfaces (Sn/Ag and Sn/Cu)” [J. Appl. Phys. 108, 103518 (2010)]

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Journal of Applied physics 2011年第2期109卷

作者： H. F. Zou Z. F. Zhang 1Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 People’s Republic of China 2Science and Technology on Reliability Physics and Application of Electronic Component Laboratory Guangzhou 51060 Guangdong People’s Republic of China

This article was originally published online on 23 November 2010 with an incorrect affiliation designation for Z. F. Zhang. Z. F. Zhang was linked to “science a

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A Virtual Channel Calculation Algorithm for application Specific On-chip Networks

A Virtual Channel Calculation Algorithm for Application Spec...

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International Workshop on Intelligent Networks and Intelligent Systems (ICINIS)

作者： Li-Wei Wang National Key Laboratory of Science and Technology on Reliability Physics and Application of Electronic Component Ministry of Industry and Information Technology Guangzhou China

A virtual channel (VC) calculation algorithm for wormhole-switched on-chip networks is proposed. Traditionally, the virtual channels were allocated uniformly, which results in a waste of area and power. To remedy this situation, based on the queuing theory, we propose a router analytical model. Using this model, the proposed algorithm calculates the bandwidth usage at each router in the network according to the traffic characteristics of the target application, and adds VC only to the channels with the highest bandwidth usage. The simulation results show that the VC allocation result is more reasonable and higher total transmission rate can be achieved compared to the uniform VC allocation. For hotspot traffic, about 33.3% savings in buffering resources can be achieved using our algorithm, in the case of achieving similar performance levels.

关键词： Bandwidth Switches System-on-a-chip Resource management Throughput Routing IEEE Press

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