Search results

1 – 10 of 14
Article
Publication date: 1 January 1992

J. Lau, G. Dody, W. Chen, M. McShane, D. Rice, S. Erasmus and W. Adamjee

The reliability of 0·5 mm pitch, 208‐pin FQFP solder joints has been studied by experimental temperature cycling and 3‐D nonlinear finite element analysis. Temperature cycling…

Abstract

The reliability of 0·5 mm pitch, 208‐pin FQFP solder joints has been studied by experimental temperature cycling and 3‐D nonlinear finite element analysis. Temperature cycling results have been presented as a Weibull distribution. Thermal fatigue life of the solder joints has been estimated based on the calculated plastic strain and isothermal fatigue data on solders. A correlation between the experimental and analytical results has also been made.

Details

Circuit World, vol. 18 no. 2
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 April 1992

J. Lau, R. Govila, C. Larner, Y.‐H. Pao, S. Erasmus, S. Dolot, M. Jalilian and M. Lancaster

Solvent‐clean and no‐clean mass reflow processes of 0.4 mm pitch, 28 mm body size, 256‐pin fine pitch quad flat packs (QFPs) are presented. Emphasis is placed on fine pitch…

Abstract

Solvent‐clean and no‐clean mass reflow processes of 0.4 mm pitch, 28 mm body size, 256‐pin fine pitch quad flat packs (QFPs) are presented. Emphasis is placed on fine pitch parameters such as printed circuit board (PCB) design, solder paste selection, stencil design, printing technology, component placement, mass reflow, cleaning and inspection. Furthermore, cross‐sections of component/PCB assemblies from both processes have been thoroughly studied using scanning electron microscopy (SEM).

Details

Circuit World, vol. 19 no. 1
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 March 1992

J. Glazer, P.A. Kramer and J.W. Morris

The effect of gold (Au) on the reliability of 0.65 mm pitch surface mount solder joints between plastic quad flat packs and Cu‐Ni‐Au FR‐4 printed circuit boards was investigated…

Abstract

The effect of gold (Au) on the reliability of 0.65 mm pitch surface mount solder joints between plastic quad flat packs and Cu‐Ni‐Au FR‐4 printed circuit boards was investigated. Cu‐Ni‐Au is a desirable printed circuit board finish for multi‐chip modules or printed circuit boards that would otherwise require a selective Au finish, for example for edge connectors or wire bondable parts. However, Au is known to embrittle solder when it is present in sufficiently high concentrations, creating a concern that solder joint fatigue life in service will also be adversely affected. This paper reports the results of mechanical shock, mechanical vibration and thermal cycling testing of fine pitch solder joints containing varying amounts of Au. Tests were performed on as‐soldered joints and on joints that had been heat‐treated to evolve the microstructure towards equilibrium. The tests were designed to accelerate in‐service conditions in a typical industrial environment. Under these conditions, the Au concentrations tested did not promote solder joint failures. Microstructural characterisation of the distribution and morphology of the Au‐, Ni‐ and Cu‐Sn intermetallics in the joint before and after accelerated testing was also performed. On the basis of these observations it is recommended that the Au concentration in solder joints between plastic quad flat packs and Cu‐Ni‐Au FR‐4 printed circuit boards not exceed 3.0 wt.%.

Details

Circuit World, vol. 18 no. 4
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 April 1993

J. Lau, S. Golwalkar, P. Boysan, R. Surratt, R. Forhringer and S. Erasmus

The reliability of 0.5 mm pitch, 32‐pin thin small outline package (TSOP) solder joints has been studied by experimental temperature cycling and a cost‐effective 3‐D non‐linear…

Abstract

The reliability of 0.5 mm pitch, 32‐pin thin small outline package (TSOP) solder joints has been studied by experimental temperature cycling and a cost‐effective 3‐D non‐linear finite element analysis. Temperature cycling results have been presented as a Weibull distribution, and an acceleration factor has been established for predicting the failure rate at operating conditions. Thermal fatigue life of the corner solder joints has been estimated based on the calculated plastic strain, Coffin‐Manson law and isothermal fatigue data on solders. A correlation between the experimental and analytical results has also been made. Furthermore, failure analysis of the solder joints has been performed using scanning electron microscopy (SEM) and an optical method. Finally, a quantitative comparison between the Type‐I and Type‐II TSOP solder joints has been presented.

Details

Circuit World, vol. 20 no. 1
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 January 1994

J. Lau, Y.‐H. Pao, C. Larner, R. Govila, S. Twerefour, D. Gilbert, S. Erasmus and S. Dolot

The reliability of 0.4 mm pitch, 28 mm body size, 256‐pin plastic quad flat pack (QFP) no‐clean and water‐clean solder joints has been studied by temperature cycling and…

Abstract

The reliability of 0.4 mm pitch, 28 mm body size, 256‐pin plastic quad flat pack (QFP) no‐clean and water‐clean solder joints has been studied by temperature cycling and analytical analysis. The temperature cycling test was run non‐stop for more than 6 months, and the results have been presented as a Weibull distribution. A unique temperature cycling profile has been developed based on the calculated lead stiffness, elastic and creep strains in the solder joint, and solder data. Also, the thermal fatigue life of the solder joints has been estimated and correlated with experimental results. Furthermore, a failure analysis of the solder joints has been performed using scanning electron microscopy (SEM). Finally, a quantitative comparison between the no‐clean and water‐clean QFP solder joints has been presented.

Details

Soldering & Surface Mount Technology, vol. 6 no. 1
Type: Research Article
ISSN: 0954-0911

Article
Publication date: 31 July 2023

Amer Sohail, Zohaib Butt, Affaf Asghar Butt and Aamer Shahzad

This study examines the effect of business group affiliations on corporate cash holdings and how political connectedness modifies the relationship between business group…

Abstract

Purpose

This study examines the effect of business group affiliations on corporate cash holdings and how political connectedness modifies the relationship between business group affiliations and corporate cash holdings.

Design/methodology/approach

The multiple ordinary least square regression with year dummies is used to estimate the effect of business groups on cash holdings. For moderating, the multiplicative term is used. The data from 252 non-financial firms listed on Pakistan Stock Exchange were collected for the analysis from 2010 to 2018.

Findings

The findings show that business group affiliations negatively affect corporate cash holdings, and political connection positively moderates this relationship. Business group firms that are politically connected hold less cash. The firm-specific factors such as leverage, size, cash flow, and dividend dummy also significantly affect corporate cash holdings.

Practical implications

The results imply that affiliated companies have lessened financing frictions and improved stability in their expected future cash flows. Moreover, the results indicate that political connection minimizes the opportunity and agency costs linked to cash holdings.

Originality/value

This study contributes to the existing literature by examining the moderating role of political affiliations on the relationship between business groups and cash holdings in the emerging market.

Details

Journal of Economic and Administrative Sciences, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1026-4116

Keywords

Content available
Article
Publication date: 1 April 2004

264

Abstract

Details

Disaster Prevention and Management: An International Journal, vol. 13 no. 2
Type: Research Article
ISSN: 0965-3562

Article
Publication date: 16 November 2020

Muhammad Usman and Asmak Ab Rahman

This paper aims to study waqf practice in Pakistan with regard to its utilisation in funding for higher educational institutions (HEIs) and investigates waqf raising, waqf

1051

Abstract

Purpose

This paper aims to study waqf practice in Pakistan with regard to its utilisation in funding for higher educational institutions (HEIs) and investigates waqf raising, waqf management and waqf income utilisation.

Design/methodology/approach

The paper is based on the views of 11 participants who are actively involved in the waqf, its raising, management and income utilisation, and is divided into three subcategories: personnel of higher educational waqf institution, personnel of waqf regulatory bodies and Shari’ah and legal experts as well as archival records, documents and library sources.

Findings

In Pakistan, both public and private awqaf are existing, but the role of private awqaf is greater in higher education funding. However, due to lack of legal supervision private awqaf is considered as a part of the not-for-profit sector and legitimately registered as a society, foundation, trust or a private limited company. Waqf in Pakistan is more focusing on internal financial sources and waqf income. In terms of waqf management, they have firm guidelines for investing in real estate, the Islamic financial sector and various halal businesses. Waqf uses the income for developmental and operational expenditure, and supports academic activities for students and staff. Waqfs are also supporting some other HEIs and research agencies. Thus, it can be revealed that a waqf can cater a sufficient amount for funding higher educational institutions.

Research limitations/implications

In Pakistan, both public and private awqaf are equally serving society in different sectors, but the role of private awqaf is much greater in funding higher education. Nevertheless, the government treats private awqaf as a part of not-for-profit sector in the absence of a specific legal framework and registers such organisations as society, foundation, trust or private limited company. The waqf in Pakistan mostly relies on internal financial resources and income from waqf assets. As the waqf managers have over the time evolved firm guidelines for investment in real estate, Islamic financial sector and various other halal businesses, and utilisation of waqf income on developmental and operational expenditures, academic activities of students and educational staff, other HEIs and research agencies, it can be proved that the waqf can potentially generate sufficient amount for funding HEIs.

Practical implications

The study presents the waqf as a social finance institution and the best alternative fiscal instrument for funding works of public good, including higher education, with the help of three selected waqf cases. Hence, the paper’s findings offer some generalisations, both for the ummah at large and Pakistan.

Social implications

The paper makes several policy recommendations for policymakers, legislators and academicians, especially the government. As an Islamic social finance institution, the waqf can help finance higher education anywhere around the world in view of the fact that most countries grapple with huge fiscal deficits and are hence financially constrained to meet growing needs of HEIs.

Originality/value

The study confirms that the waqf can be an alternative source for funding higher education institutions whether it is managed by the government or is privately controlled.

Details

International Journal of Islamic and Middle Eastern Finance and Management, vol. 14 no. 2
Type: Research Article
ISSN: 1753-8394

Keywords

Open Access
Article
Publication date: 19 December 2023

Niluthpaul Sarker and S.M. Khaled Hossain

The study aims to investigate the influence of corporate governance practices on enhancing firm value in manufacturing industries in Bangladesh.

1481

Abstract

Purpose

The study aims to investigate the influence of corporate governance practices on enhancing firm value in manufacturing industries in Bangladesh.

Design/methodology/approach

The study sample consists of 131 companies from 10 manufacturing industries listed in Dhaka stock exchange (DSE). Using the multiple regression method, the study analyzed 1,193 firm-year observations from 2012 to 2021.

Findings

The outcome reveals that managerial ownership, foreign ownership, ownership concentration, board size, board independence, board diligence and auditor quality have a significant positive influence on firm value. In contrast, audit committee size has no significant influence on firm value.

Originality/value

The practical implications of the current study demonstrated that good corporate governance creates value and must be invigorated for the interest of all stakeholders. Policymakers should formulate specific guidelines regarding firms' ownership structure and audit quality issues.

Details

PSU Research Review, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2399-1747

Keywords

Article
Publication date: 13 February 2009

Anwarul Islam and K.C. Panda

The purpose of this paper is to assess the current status of special libraries of Bangladesh and their ability to adapt information technology (IT) in various library operations…

2074

Abstract

Purpose

The purpose of this paper is to assess the current status of special libraries of Bangladesh and their ability to adapt information technology (IT) in various library operations and services.

Design/methodology/approach

The study is based on the case study method. A structured questionnaire was distributed among the special libraries of Bangladesh to uncover the status of using IT by those libraries.

Findings

Being a developing country, Bangladesh is confronted with certain problems to introduce IT‐based services and other facilities in the special libraries. The study has revealed the embryonic state of IT in the special libraries of Bangladesh.

Originality/value

The paper is an original case study on the application of IT in the Special Libraries of Bangladesh. It will help web researchers to obtain a precise picture of the application of IT in these libraries. It will also help researchers to acquaint themselves with IT applications in libraries in a third world country.

Details

The Electronic Library, vol. 27 no. 1
Type: Research Article
ISSN: 0264-0473

Keywords

1 – 10 of 14