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Article
Publication date: 6 February 2017

Andrzej Dziedzic, Pawel Osypiuk and Wojciech Steplewski

The paper aims to verify the influence of mechanical factors (longitudinal elongation at constant stretching velocity, constant elongation strain and cyclic compressive and…

Abstract

Purpose

The paper aims to verify the influence of mechanical factors (longitudinal elongation at constant stretching velocity, constant elongation strain and cyclic compressive and tensile stresses) on the electrical properties of thin-film and polymer thick-film resistors on flexible substrates.

Design/methodology/approach

Kapton foil was used as a substrate for all test samples. Designed resistive structures were made with the aid of two polymer thick-film resistive inks or OhmegaPly Ni-P resistive foil. Two different topologies – the horseshoe and triangular – were used. These topologies should have the opposite stability parameters.

Findings

Almost all presented data confirm the influence of the topology of resistors on stability of their electrical properties. The resistive materials applied for test structures also affect the stability under various mechanical exposures.

Originality/value

In general, the largest changes were caused by longitudinal elongation at constant stretching velocity, whereas other tests caused smaller changes of electrical properties. The measurements confirm the influence of topology on stability of electric properties.

Details

Soldering & Surface Mount Technology, vol. 29 no. 1
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 1 June 2003

Flavio Allella, Elio Chiodo and Davide Lauria

Series capacitive compensation in electrical power systems is generally recognized as a very economical and powerful means for increasing the transmission capability of…

Abstract

Series capacitive compensation in electrical power systems is generally recognized as a very economical and powerful means for increasing the transmission capability of long‐distance transmission lines, resulting in relevant technical advantages in power system behavior: increased steady‐state and transient stability margins, reduced voltage drop in receiving systems during occurrence of severe contingencies and reduction of transmission losses. In this paper, a general method for choosing the series compensation degree is proposed, focusing the attention on the transient stability aspect. The approach, based upon a probabilistic framework, allows to properly select – at the design stage – the optimal degree of series compensation in order to contain the instability risk at an acceptable value. The transient stability problem is formulated by using the transient energy function method. In order to show the feasibility of the proposed approach, a numerical application to the Cigre test network is performed in the final part of the paper.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 22 no. 2
Type: Research Article
ISSN: 0332-1649

Keywords

Article
Publication date: 1 April 1996

G. van Alst, P. van Dijk and F. van Meijl

Various methods are described of makingseparable electrical connections to MID structures. The firstpart discusses the use of a copper plated,glass filled plastic substrate as a…

154

Abstract

Various methods are described of making separable electrical connections to MID structures. The first part discusses the use of a copper plated, glass filled plastic substrate as a contact surface. It is shown that the morphology is different from that of conventional contacts due to the presence of dendritic growths, further that mechanical properties like stiffness and strength are lower than for solid copper. The second part discusses the application of two conventional techniques ‐ elastromeric connectors and compliant pins. Elastomeric connectors are designed to form a high density, separable interface using gold plated conductors. Compliant pins pressed into plated‐through holes form very reliable, high normal force connections without the need for noble metal plating. Two compliant pin designs have been tested with plated holes in two versions, moulded and drilled. All combinations show excellent electrical stability; however, differences were found in mechanical behaviour between the various pin and hole combinations.

Details

Circuit World, vol. 22 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 January 1994

P. Nyholm, S. Rao and H. Duffy

This paper reviews technologies used for the prevention of electromagnetic interference in current portable electronic products. It studies the need for future advanced products…

Abstract

This paper reviews technologies used for the prevention of electromagnetic interference in current portable electronic products. It studies the need for future advanced products and some of the technologies likely to be available. The focus is on housing technologies and the products available for giving greatest electromagnetic compatibility with the latest European and other emission and susceptibility standards. It is concluded that new or improved approaches which are better able to ensure long‐term reliability will be essential for the 100 MHz clock speed equipment likely to be in production within the coming five years.

Details

Circuit World, vol. 20 no. 2
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 June 1999

Ben Sitler and Ken Lo

Considers the causes of corrosion of avionics antennae and the damage damage it causes. Gives the authors’ view of the disadvantages of conventional antenna attachment and sealing…

541

Abstract

Considers the causes of corrosion of avionics antennae and the damage damage it causes. Gives the authors’ view of the disadvantages of conventional antenna attachment and sealing techniques. Details an alternative technique ‐ conductive gel gaskets ‐ using a gel sealant developed by Raychem Corporation.

Details

Aircraft Engineering and Aerospace Technology, vol. 71 no. 3
Type: Research Article
ISSN: 0002-2667

Keywords

Article
Publication date: 7 August 2023

Jiayuan Yan, Xiaoliang Zhang and Yanming Wang

As a high-performance engineering plastic, polyimide (PI) is widely used in the aerospace, electronics and automotive industries. This paper aims to review the latest progress in…

Abstract

Purpose

As a high-performance engineering plastic, polyimide (PI) is widely used in the aerospace, electronics and automotive industries. This paper aims to review the latest progress in the tribological properties of PI-based composites, especially the effects of nanofiller selection, composite structure design and material modification on the tribological and mechanical properties of PI-matrix composites.

Design/methodology/approach

The preparation technology of PI and its composites is introduced and the effects of carbon nanotubes (CNTs), carbon fibers (CFs), graphene and its derivatives on the mechanical and tribological properties of PI-based composites are discussed. The effects of different nanofillers on tensile strength, tensile modulus, coefficient of friction and wear rate of PI-based composites are compared.

Findings

CNTs can serve as the strengthening and lubricating phase of PI, whereas CFs can significantly enhance the mechanical properties of the matrix. Two-dimensional graphene and its derivatives have a high modulus of elasticity and self-lubricating properties, making them ideal nanofillers to improve the lubrication performance of PI. In addition, copolymerization can improve the fracture toughness and impact resistance of PI, thereby enhancing its mechanical properties.

Originality/value

The mechanical and tribological properties of PI matrix composites vary depending on the nanofiller. Compared with nanofibers and nanoparticles, layered reinforcements can better improve the friction properties of PI composites. The synergistic effect of different composite fillers will become an important research system in the field of tribology in the future.

Details

Industrial Lubrication and Tribology, vol. 75 no. 8
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 2 May 2017

Peter Lukacs, Alena Pietrikova and Pavol Cabuk

The purpose of this paper is to find optimal sintering conditions of silver-based nano-inks for achieving the high electrical conductivity of the deposited layers applied on…

Abstract

Purpose

The purpose of this paper is to find optimal sintering conditions of silver-based nano-inks for achieving the high electrical conductivity of the deposited layers applied on polyimide foils as well as the influence of ageing on the electrical conductivity. Therefore, the investigation in the field of silver layers deposited by inkjet printing technology is presented in this paper.

Design/methodology/approach

The four-point resistance measurements were realized for a detailed and precise analysis of the resistance of two different silver layers under different sintering conditions depending on the type of nano-ink varied about the recommended values. Highly accelerated stress tests (HASTs) were also applied as an ageing method for confirmation of the high electrical stability of the silver layers.

Findings

The results prove the strong influence of the temperature and the time of the sintering process on the sheet resistance of the investigated silver-based layers deposited by inkjet printing technology on polyimide foils. The HASTs caused significant changes in the electrical conductivity for both nano-inks presented in this paper. The existence of noticeable dependence among the resistivity, thermal treatment and ageing was proved.

Originality/value

The main benefit lays in the optimization of sintering conditions to improve the electrical conductivity of the silver layers. The paper also presents a new approach for a stability analysis of the silver layers by HASTs.

Details

Circuit World, vol. 43 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 21 November 2023

Hua Pan and Rong Liu

On the one hand, this paper is to further understand the residents' differentiated power consumption behaviors and tap the residential family characteristics labels from the…

Abstract

Purpose

On the one hand, this paper is to further understand the residents' differentiated power consumption behaviors and tap the residential family characteristics labels from the perspective of electricity stability. On the other hand, this paper is to address the problem of lack of causal relationship in the existing research on the association analysis of residential electricity consumption behavior and basic information data.

Design/methodology/approach

First, the density-based spatial clustering of applications with noise method is used to extract the typical daily load curve of residents. Second, the degree of electricity consumption stability is described from three perspectives: daily minimum load rate, daily load rate and daily load fluctuation rate, and is evaluated comprehensively using the entropy weight method. Finally, residential customer labels are constructed from sociological characteristics, residential characteristics and energy use attitudes, and the enhanced FP-growth algorithm is employed to investigate any potential links between each factor and the stability of electricity consumption.

Findings

Compared with the original FP-growth algorithm, the improved algorithm can realize the excavation of rules containing specific attribute labels, which improves the excavation efficiency. In terms of factors influencing electricity stability, characteristics such as a large number of family members, being well employed, having children in the household and newer dwelling labels may all lead to poorer electricity stability, but residents' attitudes toward energy use and dwelling type are not significantly associated with electricity stability.

Originality/value

This paper aims to uncover household socioeconomic traits that influence the stability of home electricity use and to shed light on the intricate connections between them. Firstly, in this article, from the perspective of electricity stability, the characteristics of the power consumption of residents' users are refined. And the authors use the entropy weight method to comprehensively evaluate the stability of electricity usage. Secondly, the labels of residential users' household characteristics are screened and organized. Finally, the improved FP-growth algorithm is used to mine the residential household characteristic labels that are strongly associated with electricity consumption stability.

Highlights

  1. The stability of electricity consumption is important to the stable operation of the grid.

  2. An improved FP-growth algorithm is employed to explore the influencing factors.

  3. The improved algorithm enables the mining of rules containing specific attribute labels.

  4. Residents' attitudes toward energy use are largely unrelated to the stability of electricity use.

The stability of electricity consumption is important to the stable operation of the grid.

An improved FP-growth algorithm is employed to explore the influencing factors.

The improved algorithm enables the mining of rules containing specific attribute labels.

Residents' attitudes toward energy use are largely unrelated to the stability of electricity use.

Details

Management of Environmental Quality: An International Journal, vol. 35 no. 3
Type: Research Article
ISSN: 1477-7835

Keywords

Article
Publication date: 1 April 2005

Andrzej Dziedzic, Edward Mis, Lars Rebenklau and Klaus‐Jurgen Wolter

This paper aims to present systematic studies of a wide spectrum of geometrical and electrical properties of thick‐film and LTCC microresistors (with designed dimensions between…

Abstract

Purpose

This paper aims to present systematic studies of a wide spectrum of geometrical and electrical properties of thick‐film and LTCC microresistors (with designed dimensions between 50 × 50 μm2 and 800 × 200 μm2).

Design/methodology/approach

The geometrical parameters (average length, width and thickness, relations between designed and real dimensions, distribution of planar dimensions) are correlated with basic electrical properties of resistors (sheet resistance and its distribution, hot temperature coefficient of resistance and its distribution distribution) as well as long term thermal stability and durability of microresistors to short electrical pulses.

Findings

Fodel process gives better resolution than standard screen‐printing and leads to smaller dimensions than designed, smaller absolute error and better uniformity of planar sizes. Microresistors made in full Fodel process show much weaker dimensional effect and exhibit noticeably smaller distribution of basic electrical properties.

Originality/value

Presents systematic studies of a wide spectrum of geometrical and electrical properties of thick‐film and LTCC microresistors.

Details

Microelectronics International, vol. 22 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 February 1994

H.L. Hvims

Environmental issues have an ever‐increasing influence on the selection of material and processes in electronic manufacturing. This paper discusses the use of conductive adhesives…

Abstract

Environmental issues have an ever‐increasing influence on the selection of material and processes in electronic manufacturing. This paper discusses the use of conductive adhesives as a replacement for solder on SMT printed circuit boards. As a result of a world‐wide market survey, a number of conductive adhesives have been selected. One of the two key issues of this paper has been to uncover the market for adhesive types and their composition. The other key issue has been the technical investigation of the influence of component termination and printed circuit surface types on adhesive bonding stability. Four different types of adhesives on two different metal surfaces are compared with conventional solder technology. Each adhesive has been applied to the PCBs by either screen printing or dispensing according to the manufacturer's recommendation, followed by curing. All PCBs went through thermal and humidity cycling followed by electrical measurements of resistance. Finally, all variants have been adhesion tested. All adhesive variants have been microsectioned for metallurgical and microstructure examination. Energy dispersive analysis of X‐ray (EDAX) of the metal particles in the adhesive has been carried out and documented. Rework of conductive joints is briefly commented on. Finally, aspects of occupational health are discussed concerning work with adhesive types. Work with epoxy based adhesives has been brouaht into special focus.

Details

Soldering & Surface Mount Technology, vol. 6 no. 2
Type: Research Article
ISSN: 0954-0911

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