Over GHz electrical circuit model of a high-density multiple line grid array (MLGA) interposer

The multiple line grid array (MLGA) interposer was recently introduced as a future high-density high-speed bonding method. In this paper, we introduce an electrical model and high-frequency characteristics of the MLGA interposer. The high-frequency electrical model was extracted from microwave S-parameter measurements up to 20 GHz as well as from fundamental microwave network analysis. For the parameter fitting process during model extraction, an optimization method was used. Several different types of MLGA interposers were designed, assembled and tested. The test vehicles contained coplanar waveguides, probing pads and an MLGA interposer structure. The height of the MLGA, the conductor shape inside the MLGA, and the dielectric insulator of the MLGA were varied. From the model, an MLGA with a height of 0.4 mm and a polymer dielectric insulator was found to have 203 pH of self inductance, 49 pH of mutual inductance with the nearest ground conductor line, and 186 fF of mutual capacitance. By reducing the height of the MLGA and by using an insulator with a lower dielectric constant, parasitic inductance and capacitance is further reduced. TDR/TDT simulation and measurement showed the validity of the extracted model parameters of the MLGA interposer. Circuit simulation based on the extracted model revealed that the MLGA interposer could be successfully used for microwave device packages up to 20 GHz and for high-speed digital device packages with a clock cycle up to 5 GHz.     

The law of mixtures applied to the plastic deformation of two- phase alloys of coarse microstructures

The theory of the mechanical law of mixtures is reviewed and applied to the partition of stress and of strain in two-phase alloys. It is shown that the modified law of mixtures, based on averagein situ stress and strain, is valid for small deformations and is compatible with strengthening theories based on continuum and dislocation mechanics. The plastic deformation behavior of two representative two-phase alloys,i.e., a spheroidized high carbon steel and a duplex stainless steel, was studied by taking into account the mutual interactions between phases. The law of mixtures and dispersion strengthening theory were used to evaluate the strength contribution of each phase.     

Computational Implementation of Asymmetric Integral Imaging by Use of Two Crossed Lenticular Sheets

We propose an asymmetric integral imaging method to adjust the resolution and depth of a three‐dimensional image. Our method is obtained by use of two lenticular sheets with different pitches fabricated under the same F/#. The asymmetric integral imaging is the generalized version of integral imaging, including both conventional integral imaging and one‐dimensional integral imaging. We present experimental results to test and verify the performance of our method computationally.     

Experimental investigation of natural convection from a horizontal ice surface melting in pure water

A study on natural convection from a horizontal ice surface melting in pure water was conducted experimentally for the ambient water temperature from 2▿C to 10°C. Natural convection flow around upward-or downward-facing horizontal ice plate was divided into three regions according to the temperature variation of ambient water. The flow patterns of three regions were no flow, two-dimensional steady laminar flow and unsteady flow. Mean Nusselt number for the upward-facing surface had its maximum value at about 3°C of ambient water temperature. However, in the case of the downward-facing surface it increased as the ambient water temperature increased.     

Feature selection techniques and comparative studies for large-scale manufacturing processes

In order to efficiently and effectively control an overall process in the process industry, a few important parameters should be identified from high-dimensional, non-linear, and correlated data. Feature selection techniques can be employed to extract a subset of process parameters relevant to product quality. The performance of these techniques depends on the precision of the prediction model formulated to quantify the relationship between the process parameters and the quality characteristics. Although the neural network-based partial least squares (NNPLS) method has been proven to be effective in prediction models for the aforementioned industrial process data, feature selection techniques appropriate for NNPLS models have yet to appear. Here, several techniques for scoring the relevance of process parameters to product quality are proposed and validated by applying three datasets. These experiments show that the proposed techniques can discriminate relevant process parameters from irrelevant ones.     

Aluminum deoxidation equilibrium in liquid Ni-Fe alloys equilibrated with CaO-Al2O3 slags

The deoxidation equilibrium for Al in Ni-Fe alloys was studied in the equilibrium experiments between CaO-Al₂O₃ slags and Fe-30, 50 and 70 % Ni alloys at 1873 K. By using the values for the first and second order interaction parameters between oxygen and nickel in liquid iron and those between oxygen and iron in liquid nickel, the effect of Ni on the activity coefficient of Al in liquid iron and that of Fe on the activity coefficient of Al in liquid nickel were determined in the whole composition range of Ni-Fe alloys. The oxygen contents in Ni-Fe alloys calculated by the iterative method based on pure iron were in good agreement with those based on pure nickel in the range of [% Al] < 0.03. From this fact, it was found that the Wagner's approximation relating to the multi-component solution was applicable to the deoxidation equilibrium in the whole composition range of Ni-Fe alloys in the restricted concentration of a deoxidizer.     

Numerical analysis of the warpage problem in TSOP

The reliability and the solderability of thin small outline package (TSOP) are significantly affected by the warpage that is generated after epoxy molding compound (EMC) molding process. This warpage problem mainly results from the mismatch of material properties such as Young's modulus, Poisson's ratio and coefficient of thermal expansion (CTE) and the geometric structure of each component for TSOP. The optimization of both material properties and geometric structures using the numerical analysis is necessary to reduce the warpage of TSOP. However, there are still some limitations for the numerical analysis to obtain proper results consistent with the practical warpage values. In this paper, the numerical analysis is performed under the assumption of elastic behavior for EMC. Furthermore, to solve the limitations, the material properties at the molding temperature and the degree of reaction rate at the end of the molding process of EMC are considered together for the analysis. This numerical analysis gives the higher warpage values than the measured ones, and is applicable to the practical design of the reliable electronic package.     

Effective sludge solubilization treatment by simultaneous use of ultrasonic and electrochemical processes.

Sludge disintegration treatment by using simultaneously ultrasonic irradiation and electrolysis was investigated experimentally. A lab-scale diaphragm cell irradiated with ultrasound at a constant oscillating frequency of 20 kHz was used as a reactor. The batch experiments were carried out under different conditions of electric outputs of the ultrasonic generator, electric current for the electrolysis and different initial SS concentrations. A simultaneous treatment in the cathodic compartment without any chemical doses considerably facilitated the sludge solubilization, compared to the sonication alone. An increase in the electric current up to 400 mA under a constant ultrasonic density decreased the specific energy by 55% within the experimental range. The specific energy consumption was also reduced when the initial SS concentration increased. In addition, before carrying out the simultaneous treatment, a brief electrolysis was effective for further reduction of the specific energy and the acceleration of soluble COD generation.