Journal of Electronic Packaging, Transactions of the ASME

Publisher: American Society of Mechanical Engineers

Current impact factor: 0.86

Impact Factor Rankings

2016 Impact Factor Available summer 2017
2014 / 2015 Impact Factor 0.856
2013 Impact Factor 0.645
2012 Impact Factor 0.934
2011 Impact Factor 0.694
2010 Impact Factor 0.564
2009 Impact Factor 0.781
2008 Impact Factor 0.827
2007 Impact Factor 0.583
2006 Impact Factor 0.487
2005 Impact Factor 0.428
2004 Impact Factor 0.383
2003 Impact Factor 0.378
2002 Impact Factor 0.33
2001 Impact Factor 0.47
2000 Impact Factor 0.359
1999 Impact Factor 0.31
1998 Impact Factor 0.345
1997 Impact Factor 0.12

Impact factor over time

Impact factor

Additional details

5-year impact 0.84
Cited half-life 8.70
Immediacy index 0.12
Eigenfactor 0.00
Article influence 0.24
ISSN 1528-9044

Publisher details

American Society of Mechanical Engineers

  • Pre-print
    • Author cannot archive a pre-print version
  • Post-print
    • Author cannot archive a post-print version
  • Classification

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: The local surface temperature, heat flux, heat transfer coefficient, and Nusselt number were measured for an inline array of circular, normal jets of single-phase, liquid water impinging on a copper block with a common outlet for spent flow, and an experimental two-dimensional (2D) surface map was obtained by translating the jet array relative to the sensors. The effects of variation in jet height, jet pitch, confining wall angle, and average jet Reynolds number were investigated. A strong interaction between the effects of the geometric parameters was observed, and a 5 deg confining wall was seen to be an effective method of managing the spent flow for jet impingement cooling of power electronics. The maximum average heat transfer coefficient of 13,100 W/m2 K and average Nusselt number of 67.7 were measured at an average jet Reynolds number of 14,000.
    No preview · Article · Sep 2015 · Journal of Electronic Packaging, Transactions of the ASME
  • [Show abstract] [Hide abstract]
    ABSTRACT: FeNi alloy is considered a possible substitute for Cu as under bump metallization (UBM) in wafer level package (WLP) since it forms very thin intermetallic compound (IMC) layer with Pb-free solder in the reflow process. In this paper, WLPs with FeNi and Cu UBM were fabricated and their board level reliabilities were studied comparatively. The WLP samples assembled on the printed circuit board (PCB) were subjected to temperature cycling and drop tests according to JEDEC standards. The results showed that the reliability of WLP with FeNi UBM was a little lower than that with Cu UBM. The main failure modes for both FeNi and Cu UBM samples in temperature cycling test were the crack in IMC or solder ball on PCB side. And detachments between UBM and the redistribution layer (RDL) were also observed in Cu UBM WLPs. In drop test, the crack of RDL was found in all failed FeNi UBM samples and part of Cu UBM ones, and the primary failure mode in Cu UBM samples was the crack of IMC on PCB side. In addition, the finite element analysis (FEA) was carried out to further understand the difference of the failure modes between the FeNi UBM samples and the Cu UBM samples. The high stress was observed around the UBM and the pad on PCB in the temperature cycling model. And the maximum stress appeared on the RDL in the drop simulation, which was obviously larger than that on the pad. The FEA results showed that the introduction of FeNi UBM increased the stress levels both in temperature cycling and drop tests. Thus, the FeNi alloy cannot simply replace Cu as UBM in WLP without further package structural optimization.
    No preview · Article · Sep 2015 · Journal of Electronic Packaging, Transactions of the ASME
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    ABSTRACT: In situ sensors can measure wire bond reliability nondestructively during thermal aging. Conventional thermal aging of ball bonds requires ovens heating the entire microchip along with the wire bonds, also affecting interconnects for in situ sensors. To protect the interconnects and on-chip logic components of in situ sensor chips, conventional thermal aging is kept below a safe temperature limit of 200°C. At higher temperatures, the doped Si components change their characteristics and transistors stop working. Localized on-chip heating is introduced to circumvent these drawbacks using a new microheater to increase the safe temperature limit for nondestructive reliability assessment with in situ sensors. The effect of temperature on surrounding components is reduced. The microheater is a rectangular design resistive heater made from N+ silicon. In addition, a pad resistance measurement is introduced that indicates bond aging more conveniently than previously reported bond resistance measurements.
    No preview · Article · Mar 2015 · Journal of Electronic Packaging, Transactions of the ASME
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    ABSTRACT: Dimple and protrusion play important roles in the heat transfer enhancement and flow characteristic in cooling channels, which widely employed within electronic cooling systems. Non-Newtonian fluid has significant differences with Newtonian fluid, such as water, in fluid characteristic. In this study, an experiment on the viscosity of three different kinds of non-Newtonian fluids, i.e., xanthan gum solution, Carbopol 934 solution, polyacrylamide solution, was first accomplished to acquire the viscosity with different mass fractions. Then, experimental measurements on heat transfer and friction characteristics of non-Newtonian fluid in a rectangular channel with dimples and protrusions were conducted. The overall Nusselt numbers (Nu) and Fanning friction factors at different dimple/protrusion structures were obtained with various inlet flow rates and mass fractions. The results show that only xanthan gum solution has the significant shear thinning effect within the concentration range of this study, and the dimples/protrusions both have great effect on the heat transfer enhancement in the rectangular channel, and that the heat transfer of the case with the protrusions and crossing arrangement can be further enhanced with the higher Nu when compared to the case with the dimples and aligned arrangement. Moreover, an increase in Nu with the higher non-Newtonian fluid mass fraction is observed.
    No preview · Article · Jun 2014 · Journal of Electronic Packaging, Transactions of the ASME
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    ABSTRACT: A model of mini heat sink with microchannels was developed to obtain homogeneous heat transfer capability. The channels are constructed in the form of eight triangular arrays based on a square substrate. Air is sucked from the periphery to the center of the substrate by a vacuum pump and heat transferred from the bottom surface of substrate can be removed by air flowing through channels. Corresponding to the given heat transfer power and the target temperature of substrate, the relationship among length, width and depth of channel was analytically established. By numerical simulation, local pressure drops at the joint of channels and air duct are first obtained and then the dimensions of each channel in a triangular array can be determined one by one. The investigation reveals that the widths of channels will vary with their depths, lengths and pressure differences between two ends. Since all channels are required for the same cooling power, the homogeneous heat transfer of heat sink can be realized. By assembling a certain number of heat sink units, the area of dissipation of heat sink can be enlarged and contoured to fit close to heating surface.
    No preview · Article · Jun 2014 · Journal of Electronic Packaging, Transactions of the ASME
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    ABSTRACT: This study goes beyond the common micro-channel cooling system composed of uniform parallel straight micro-channels. Due to the highly non-uniform power dissipation on a multicore processor, the micro-channel cooling system is designed to fit with the heat load on the multicore processor. By applying effective strategies and arranging key design parameters, stronger cooling is provided under the high power core area, and less cooling is provided under the low power cache area to save the precious pumping power. The well designed thermal-aware micro-channel cooling systems could effectively lower the hot spot temperature and temperature gradients on chip.A three-stage approach to design thermal-aware micro-channel cooling system for multicore processor is developed. Two micro-channel cooling systems are specifically designed for a 2 core 150W Intel Tulsa processor and an 8 core 260W (doubled power) Intel Nehalem processor, to illustrate the design approach. The working fluid is single phase HFE7100. For the Tulsa processor, a strategy named strip-and-zone approach is used. The final design leads to 30kPa pressure drop and 0.094W pumping power while maintains the hot spot temperature to be 75 °C. For the Nehalem processor, a split flow micro-channel system and a widen-inlet strategy are applied. The final design takes 15kPa pressure drop and 0.0845W pumping power while maintains the hot spot temperature to be 82.8 °C. The design approach in this study provides the basic guide for the industrial applications of effective multicore processor cooling using micro-channels.
    No preview · Conference Paper · Nov 2013
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    ABSTRACT: This investigation is aimed at the modeling of both the fabrication process and the reliability of press-fit interconnections on moulded interconnect devices (MID). These are multifunctional three-dimensional substrates, produced by thermoplastic injection moulding for large-series applications. The assembly process and subsequently the durability of press-fit interconnections has been modeled and proved with a finite element software. Especially, a simulation tool for process optimizations was created and applied. In order to obtain realistic results, a creep model for the investigated base material, a liquid-crystal polymer (LCP), was generated and verified by experiments. Required friction coefficients between metal pin and base material were determined by adapting simulations and experiments. Retention forces of pins pressed into substrate holes during as well after the assembly process, and after temperature loads were predicted by simulations. Additionally, the decreasing extraction forces over time due to creep in the thermoplastic base material have been predicted for different storage temperatures as well with finite element analyses. Following, the numerical results of the process and reliability modeling were verified by experiments. It is concluded that the behavior of the mechanical contact of the pin-substrate system, can be suitably described time-and temperature-dependent.
    No preview · Article · Sep 2012 · Journal of Electronic Packaging, Transactions of the ASME
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    ABSTRACT: This paper investigates the mechanical behavior of a copper-solder interface when subjected to varying strain rate loading between 0.05 s -1 and 10.0 s -1. The copper is alloy 101, and the solder is lead-free type with a composition of 96 tin and 4 silver. Both uniform and nonuniform two-level strain rate loadings were applied. For the two-level strain rate loading, the strain rate was changed from one level to another during the loading process as a step change. The strain rate tests were performed at room temperature as well as at an elevated temperature of 65 °C. The test results showed significant effects of uniform and nonuniform strain rates as well as temperature on fracture surface, peak stress, fracture strain, modulus, and stored energy density until fracture. Generally, a higher strain rate increased the peak stress and fracture strain, but decreased the modulus. The heated specimens showed significantly reduced strength and fracture strain at high strain rates when compared to the specimens tested at room temperature. For the two-level strain rates, the sequence of the loading rates affected the material behavior significantly. The peak stress under the two-level strain rates might be located outside the range that was determined by the two individual uniform strain rates occurring in the two-level rates. On the other hand, the fracture strain under two-level strain rate loading always fell inside that range. An expression was proposed to predict the interface fracture strains for the case of a two-level strain rate loading based on the data of each respective single-level strain test. The prediction was reasonable when compared to the experimental data with an average absolute error of 10.
    No preview · Article · Sep 2012 · Journal of Electronic Packaging, Transactions of the ASME
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    ABSTRACT: The development of a solder-based vacuum bonding technique for micro-electro mechanical systems (MEMS) applications is presented. A chip with a micro-sensor was bonded to a cover plate to form a sealed cavity. The method relies on a solder-based hybridization comprising a self-assembly process that takes advantage of the surface tension and viscous forces of the solder. A model of the assembly was developed to predict the capillary instability of the solde, and the dynamic behavior of the assembled chip. Experimental results showed that a molten bead with parallel contact lines is stable when the ratio between the solder height and solder width is less than one half. Misalignment attributed to the self-assembly process was within a few microns. Fractographic analysis and leak and shear tests confirmed the predicted sealing and mechanical characteristics of the bonding. This method is especially suitable for bonding wafers in a vacuum for MEMS and other micro-devices, at low manufacturing temperatures (∼250 °C).
    No preview · Article · Jun 2012 · Journal of Electronic Packaging, Transactions of the ASME