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B. Stephan - One of the best experts on this subject based on the ideXlab platform.

  • Reliability of thermally stressed rigid-flex printed circuit boards for High Density Interconnect applications
    Microelectronics Reliability, 2014
    Co-Authors: Abdellah Salahouelhadj, Marion Martiny, Sébastien Mercier, L. Bodin, D. Manteigas, B. Stephan
    Abstract:

    The thermal fatigue of vias in rigid-flex printed circuit boards (PCB) is considered in the paper. Dedicated printed circuit boards have been designed with different geometrical configurations (Plating Thickness, drilled hole diameter and PCB Thickness). The PCB is made of hundreds of vias or holes which are wired by copper path to create a daisy chain. The PCB is subject to cyclic thermal loading (-55 degrees C, +125 degrees C). Electrical connectivity is recorded during tests. Cross sectioning is performed finally to characterize the loss of electrical connectivity. Fracture of plated copper, due to the thermal expansion mismatch between constituents, is shown to be responsible for the failure of the PCB. In addition to environmental tests, finite element model is developed to analyze the deformation of PCBs during thermal cycling. Areas of strain concentration determined by Finite Element Analysis (FEA) are consistent with locations where cracks were observed in experiments. In addition, the numerical estimation of the plastic strain increment per cycle enables the prediction of the fatigue life. The results confirm that for rigid flex boards, the fatigue life of vias increases with higher Plating Thickness, larger drilled hole size and lower PCB Thickness. Numerical results are shown to be in good agreement with experiments.

  • Reliability of thermally stressed rigid–flex printed circuit boards for High Density Interconnect applications
    Microelectronics Reliability, 2013
    Co-Authors: Abdellah Salahouelhadj, Marion Martiny, Sébastien Mercier, L. Bodin, D. Manteigas, B. Stephan
    Abstract:

    Abstract The thermal fatigue of vias in rigid–flex printed circuit boards (PCB) is considered in the paper. Dedicated printed circuit boards have been designed with different geometrical configurations (Plating Thickness, drilled hole diameter and PCB Thickness). The PCB is made of hundreds of vias or holes which are wired by copper path to create a daisy chain. The PCB is subject to cyclic thermal loading (−55 °C, +125 °C). Electrical connectivity is recorded during tests. Cross sectioning is performed finally to characterize the loss of electrical connectivity. Fracture of plated copper, due to the thermal expansion mismatch between constituents, is shown to be responsible for the failure of the PCB. In addition to environmental tests, finite element model is developed to analyze the deformation of PCBs during thermal cycling. Areas of strain concentration determined by Finite Element Analysis (FEA) are consistent with locations where cracks were observed in experiments. In addition, the numerical estimation of the plastic strain increment per cycle enables the prediction of the fatigue life. The results confirm that for rigid flex boards, the fatigue life of vias increases with higher Plating Thickness, larger drilled hole size and lower PCB Thickness. Numerical results are shown to be in good agreement with experiments.

Abdellah Salahouelhadj - One of the best experts on this subject based on the ideXlab platform.

  • Reliability of thermally stressed rigid-flex printed circuit boards for High Density Interconnect applications
    Microelectronics Reliability, 2014
    Co-Authors: Abdellah Salahouelhadj, Marion Martiny, Sébastien Mercier, L. Bodin, D. Manteigas, B. Stephan
    Abstract:

    The thermal fatigue of vias in rigid-flex printed circuit boards (PCB) is considered in the paper. Dedicated printed circuit boards have been designed with different geometrical configurations (Plating Thickness, drilled hole diameter and PCB Thickness). The PCB is made of hundreds of vias or holes which are wired by copper path to create a daisy chain. The PCB is subject to cyclic thermal loading (-55 degrees C, +125 degrees C). Electrical connectivity is recorded during tests. Cross sectioning is performed finally to characterize the loss of electrical connectivity. Fracture of plated copper, due to the thermal expansion mismatch between constituents, is shown to be responsible for the failure of the PCB. In addition to environmental tests, finite element model is developed to analyze the deformation of PCBs during thermal cycling. Areas of strain concentration determined by Finite Element Analysis (FEA) are consistent with locations where cracks were observed in experiments. In addition, the numerical estimation of the plastic strain increment per cycle enables the prediction of the fatigue life. The results confirm that for rigid flex boards, the fatigue life of vias increases with higher Plating Thickness, larger drilled hole size and lower PCB Thickness. Numerical results are shown to be in good agreement with experiments.

  • Reliability of thermally stressed rigid–flex printed circuit boards for High Density Interconnect applications
    Microelectronics Reliability, 2013
    Co-Authors: Abdellah Salahouelhadj, Marion Martiny, Sébastien Mercier, L. Bodin, D. Manteigas, B. Stephan
    Abstract:

    Abstract The thermal fatigue of vias in rigid–flex printed circuit boards (PCB) is considered in the paper. Dedicated printed circuit boards have been designed with different geometrical configurations (Plating Thickness, drilled hole diameter and PCB Thickness). The PCB is made of hundreds of vias or holes which are wired by copper path to create a daisy chain. The PCB is subject to cyclic thermal loading (−55 °C, +125 °C). Electrical connectivity is recorded during tests. Cross sectioning is performed finally to characterize the loss of electrical connectivity. Fracture of plated copper, due to the thermal expansion mismatch between constituents, is shown to be responsible for the failure of the PCB. In addition to environmental tests, finite element model is developed to analyze the deformation of PCBs during thermal cycling. Areas of strain concentration determined by Finite Element Analysis (FEA) are consistent with locations where cracks were observed in experiments. In addition, the numerical estimation of the plastic strain increment per cycle enables the prediction of the fatigue life. The results confirm that for rigid flex boards, the fatigue life of vias increases with higher Plating Thickness, larger drilled hole size and lower PCB Thickness. Numerical results are shown to be in good agreement with experiments.

Yasuhiro Hattori - One of the best experts on this subject based on the ideXlab platform.

  • Observation of Tin Plated Fretting Contacts Using FIB-SEM
    IEICE Transactions on Electronics, 2010
    Co-Authors: Tetsuya Ito, Yoshiyuki Nomura, Yasuhiro Hattori
    Abstract:

    In this report, Focused Ion Beam (FIB) — SEM technique was applied to observe the tin plated fretting contacts. Spatial distributions of tin, tin oxide and so on have been confirmed quantitatively in two Plating Thickness of 1 and 5 μm.

  • Effect of Contact Force on the Friction Coefficient of Electroplated Tin Films for Automotive Applications
    Journal of The Japan Institute of Metals, 2009
    Co-Authors: Shigeru Sawada, Terutaka Tamai, Yasuhiro Hattori
    Abstract:

    Tin Plating is commonly applied for automotive connectors. To clarify the mechanism of fretting corrosion of tin Plating, friction coefficient behavior of tin Plating is needed to investigate in detail. In this study, the factors of the friction coefficient for tin Plating contact were examined in the case of embossment-plane contact. As experimental results it was found that the friction coefficient is affected by contact force, Plating Thickness and contact radius. The force dependence of the real contact area estimated by FEM analysis shows that the real contact area occurred by elasto-plastic deformation. A larger contact radius and thicker Plating Thickness result in a larger friction coefficient, because the real contact area is larger. A heavier force results in a smaller friction coefficient, because the average of the contact pressure is larger. The shear stress, which is estimated from experimental results, is much higher than that of tin metal. This indicates that tin attrition of embossment-plane contact is not the shear of tin metal on tin metal but the shear of tin metal on tin oxide according to the hardness results of the tin oxide layer.

  • Micro-Structural Study of Fretting Contact Caused by the Difference of the Tin Plating Thickness
    IEICE Transactions on Electronics, 2008
    Co-Authors: Tetsuya Ito, Terutaka Tamai, Yasuhiro Hattori, Yasushi Saitoh, Shigeru Sawada, Kazuo Iida
    Abstract:

    In recent years, there has been increasing demand to miniaturize wiring harness connectors in automobiles due to the increasing volume of electronic equipment and the reduction of the installation space allocated for the electronic equipment in automobiles for the comfort of the passengers. With this demand, contact failure caused by the fretting corrosion is expected to become a serious problem. In this report, we examined micro-structural observations of fretting contacts of two different tin Plating Thicknesses using Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM) and so on. Based on the results, we compared the microstructure difference of fretting contact caused by the difference of the tin Plating Thickness.

  • Microscopy study of fretting corrosion caused by the tin Plating Thickness
    Electrical Contacts Proceedings of the Annual Holm Conference on Electrical Contacts, 2008
    Co-Authors: Tetsuya Ito, Terutaka Tamai, Yasuhiro Hattori, Yasushi Saitoh, Shigeru Sawada, Kazuo Iida
    Abstract:

    In recent years, there has been increasing demand to miniaturize wiring harness connectors in automobiles due to the increasing volume of electronic equipment and the reduction of the installation space allocated for the electronic equipment in automobiles for the comfort of the passengers. With this demand, contact failure caused by the fretting corrosion seems to become a serious problem in the future. There are many reports about fretting contact resistance transitions from the low contact resistance level to the high contact resistance level, but there are few reports about observation of the microstructure transition. In our previous study, we conducted observation using SEM, TEM and micro hardness measurement using a nanoindentation tester on low and high contact resistance samples (dimple-flat configuration) under the fixed test conditions (contact load: IN, tin Plating Thickness:5 mum). In this report, we examined microstructure observation of flat fretting contacts, modifying the tin Plating Thickness as a parameter. Based on the observation results, we considered the change of the contact microstructure and the difference of the contact resistance rising curve behavior caused by the tin Plating Thickness.

Marion Martiny - One of the best experts on this subject based on the ideXlab platform.

  • Reliability of thermally stressed rigid-flex printed circuit boards for High Density Interconnect applications
    Microelectronics Reliability, 2014
    Co-Authors: Abdellah Salahouelhadj, Marion Martiny, Sébastien Mercier, L. Bodin, D. Manteigas, B. Stephan
    Abstract:

    The thermal fatigue of vias in rigid-flex printed circuit boards (PCB) is considered in the paper. Dedicated printed circuit boards have been designed with different geometrical configurations (Plating Thickness, drilled hole diameter and PCB Thickness). The PCB is made of hundreds of vias or holes which are wired by copper path to create a daisy chain. The PCB is subject to cyclic thermal loading (-55 degrees C, +125 degrees C). Electrical connectivity is recorded during tests. Cross sectioning is performed finally to characterize the loss of electrical connectivity. Fracture of plated copper, due to the thermal expansion mismatch between constituents, is shown to be responsible for the failure of the PCB. In addition to environmental tests, finite element model is developed to analyze the deformation of PCBs during thermal cycling. Areas of strain concentration determined by Finite Element Analysis (FEA) are consistent with locations where cracks were observed in experiments. In addition, the numerical estimation of the plastic strain increment per cycle enables the prediction of the fatigue life. The results confirm that for rigid flex boards, the fatigue life of vias increases with higher Plating Thickness, larger drilled hole size and lower PCB Thickness. Numerical results are shown to be in good agreement with experiments.

  • Reliability of thermally stressed rigid–flex printed circuit boards for High Density Interconnect applications
    Microelectronics Reliability, 2013
    Co-Authors: Abdellah Salahouelhadj, Marion Martiny, Sébastien Mercier, L. Bodin, D. Manteigas, B. Stephan
    Abstract:

    Abstract The thermal fatigue of vias in rigid–flex printed circuit boards (PCB) is considered in the paper. Dedicated printed circuit boards have been designed with different geometrical configurations (Plating Thickness, drilled hole diameter and PCB Thickness). The PCB is made of hundreds of vias or holes which are wired by copper path to create a daisy chain. The PCB is subject to cyclic thermal loading (−55 °C, +125 °C). Electrical connectivity is recorded during tests. Cross sectioning is performed finally to characterize the loss of electrical connectivity. Fracture of plated copper, due to the thermal expansion mismatch between constituents, is shown to be responsible for the failure of the PCB. In addition to environmental tests, finite element model is developed to analyze the deformation of PCBs during thermal cycling. Areas of strain concentration determined by Finite Element Analysis (FEA) are consistent with locations where cracks were observed in experiments. In addition, the numerical estimation of the plastic strain increment per cycle enables the prediction of the fatigue life. The results confirm that for rigid flex boards, the fatigue life of vias increases with higher Plating Thickness, larger drilled hole size and lower PCB Thickness. Numerical results are shown to be in good agreement with experiments.

L. Bodin - One of the best experts on this subject based on the ideXlab platform.

  • Reliability of thermally stressed rigid-flex printed circuit boards for High Density Interconnect applications
    Microelectronics Reliability, 2014
    Co-Authors: Abdellah Salahouelhadj, Marion Martiny, Sébastien Mercier, L. Bodin, D. Manteigas, B. Stephan
    Abstract:

    The thermal fatigue of vias in rigid-flex printed circuit boards (PCB) is considered in the paper. Dedicated printed circuit boards have been designed with different geometrical configurations (Plating Thickness, drilled hole diameter and PCB Thickness). The PCB is made of hundreds of vias or holes which are wired by copper path to create a daisy chain. The PCB is subject to cyclic thermal loading (-55 degrees C, +125 degrees C). Electrical connectivity is recorded during tests. Cross sectioning is performed finally to characterize the loss of electrical connectivity. Fracture of plated copper, due to the thermal expansion mismatch between constituents, is shown to be responsible for the failure of the PCB. In addition to environmental tests, finite element model is developed to analyze the deformation of PCBs during thermal cycling. Areas of strain concentration determined by Finite Element Analysis (FEA) are consistent with locations where cracks were observed in experiments. In addition, the numerical estimation of the plastic strain increment per cycle enables the prediction of the fatigue life. The results confirm that for rigid flex boards, the fatigue life of vias increases with higher Plating Thickness, larger drilled hole size and lower PCB Thickness. Numerical results are shown to be in good agreement with experiments.

  • Reliability of thermally stressed rigid–flex printed circuit boards for High Density Interconnect applications
    Microelectronics Reliability, 2013
    Co-Authors: Abdellah Salahouelhadj, Marion Martiny, Sébastien Mercier, L. Bodin, D. Manteigas, B. Stephan
    Abstract:

    Abstract The thermal fatigue of vias in rigid–flex printed circuit boards (PCB) is considered in the paper. Dedicated printed circuit boards have been designed with different geometrical configurations (Plating Thickness, drilled hole diameter and PCB Thickness). The PCB is made of hundreds of vias or holes which are wired by copper path to create a daisy chain. The PCB is subject to cyclic thermal loading (−55 °C, +125 °C). Electrical connectivity is recorded during tests. Cross sectioning is performed finally to characterize the loss of electrical connectivity. Fracture of plated copper, due to the thermal expansion mismatch between constituents, is shown to be responsible for the failure of the PCB. In addition to environmental tests, finite element model is developed to analyze the deformation of PCBs during thermal cycling. Areas of strain concentration determined by Finite Element Analysis (FEA) are consistent with locations where cracks were observed in experiments. In addition, the numerical estimation of the plastic strain increment per cycle enables the prediction of the fatigue life. The results confirm that for rigid flex boards, the fatigue life of vias increases with higher Plating Thickness, larger drilled hole size and lower PCB Thickness. Numerical results are shown to be in good agreement with experiments.