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Article
Publication date: 1 April 1993

O.A. Palusinski and M. Abdennadher

The transient simulation of integrated circuit has become very expensive in terms of computer time due to increase in the number of transistors in typical simulation…

Abstract

The transient simulation of integrated circuit has become very expensive in terms of computer time due to increase in the number of transistors in typical simulation. Spectral technique and Chebyshev polynomials offers an efficient alternative algorithm for simulation of integrated circuits. In this paper an automatic formulation of circuit elements and transistor models, built in MOS technology, for analysis using spectral technique is presented. The algorithm is implemented and the simulation is proven to require less computer time than in the case of SPICE or ASTAP

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 12 no. 4
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 April 1991

O.A. Palusinski and M.W. Guarini

Waveform relaxation has potential to overcome problem of excessive computer run times which are necessary for simulation of larger circuits with the use of existing…

Abstract

Waveform relaxation has potential to overcome problem of excessive computer run times which are necessary for simulation of larger circuits with the use of existing simulators. One of the attractive features of waveform relaxation is its suitability for parallel implementation. Amount of data necessary for interchange between parallel processors after each iteration influences the overall performance of simulation. Method of integration based on Chebyshev series provides for representation of solutions in the most compact form which makes it very attractive for parallel implementations. This paper presents some results of numerical experiments with the spectral integration applied in the relaxation framework to a number of MOS circuits.

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COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 10 no. 4
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 1 February 1992

O. Pedersen, B.‐E. Flaten and T. Gleditsch

A new model for the power system, covering resistance, self‐inductance, mutual inductance, and capacitive coupling between planes is presented. The model parameters are…

Abstract

A new model for the power system, covering resistance, self‐inductance, mutual inductance, and capacitive coupling between planes is presented. The model parameters are calculated from the geometry of the actual board. No measurements are necessary to set up a model for a new board. The model has been verified against detailed computer simulations and measured data.

Details

Circuit World, vol. 18 no. 3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 1 August 2002

Abstract

Details

Microelectronics International, vol. 19 no. 2
Type: Research Article
ISSN: 1356-5362

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Article
Publication date: 13 February 2007

J. Liang, N. Dariavach, P. Callahan and D. Shangguan

To investigate effects of the thermal history on intermetallic thickness and morphology and on the resulting shear strength of the ball attachment for a variety of BGA components.

Abstract

Purpose

To investigate effects of the thermal history on intermetallic thickness and morphology and on the resulting shear strength of the ball attachment for a variety of BGA components.

Design/methodology/approach

In this study, a variety of BGA components with balls made of Pb‐free Sn‐Ag‐Cu (SAC) 305, Sn‐Pb eutectic and high‐temperature 90Pb‐10Sn alloys, were subjected to different thermal histories, including up to ten reflow cycles, and aged at 125°C from 24 to 336 h. The intermetallic thickness and morphology after these thermal events were then examined under optical and scanning electronic microscopes. Ball shearing tests were conducted to investigate effects of the thermal history and intermetallic thickness and morphology on shearing strength of these solder balls.

Findings

The results show that effects directly from intermetallic layers may or may not be detectable; and the shear strength of solder balls is largely dependent on the solder alloy and its microstructure. Shear strength increases are observed after multiple reflow cycles and ageing at elevated temperature for the two Pb‐bearing alloys, while the SAC305 lead‐free alloy shows slight reductions in both strength and ductility after thermal exposure.

Practical implications

Presented results can be used for estimation of reliability for electronic assemblies subjected to multiple rework and repair operations, which expose sensitive components, such as BGAs, to elevated temperatures.

Originality/value

It is believed that a sound understanding of the effects of intermetallic morphology and thickness on reliability of BGA solder balls can lead to more intelligent choice of soldering processes, as well as to rework/repair process optimisation and to establishing their operational limits.

Details

Soldering & Surface Mount Technology, vol. 19 no. 1
Type: Research Article
ISSN: 0954-0911

Keywords

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