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Article
Publication date: 1 January 1995

D.M. Tench, D.P. Anderson, P. Jambazian, P. Kim, J. White, D. Hillman, D. Frommelt, G.K. Lucey, T. Gher and B. Piekarski

The recently developed Reduced Oxide Soldering Activation (ROSA™) method is shown to be compatible with long‐term use with mass soldering processes. Prototype regeneration cells…

46

Abstract

The recently developed Reduced Oxide Soldering Activation (ROSA™) method is shown to be compatible with long‐term use with mass soldering processes. Prototype regeneration cells operated for as long as six months with minimal maintenance retained their effectiveness for providing short wetting times under a variety of perturbations. The operating window for the process is wide and component degradation caused by exposure to the fully charged solution is minimal. The ROSA treatment provides soldering performance comparable to that attainable with a fully activated rosin flux and offers the promise of providing low soldering defect rates without the use of CFC solvents.

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Soldering & Surface Mount Technology, vol. 7 no. 1
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 1 February 1995

D.M. Tench, J.T. White, D. Hillman, G.K. Lucey, T. Gher and B. Piekarski

Fluxless wave soldering in a nitrogen atmosphere was investigated for epoxy‐fibreglass circuit board coupons having bare copper and solder‐coated through‐holes. The Reduced Oxide…

23

Abstract

Fluxless wave soldering in a nitrogen atmosphere was investigated for epoxy‐fibreglass circuit board coupons having bare copper and solder‐coated through‐holes. The Reduced Oxide Soldering Activation (ROSA™) pretreatment was found to consistently provide good hole filling and through‐hole solder joints of excellent appearance. For preheated coupons, low levels of residual oxygen and short exposure to air after the ROSA treatment were found to have no effect

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Circuit World, vol. 21 no. 2
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 1 February 1994

J.S. Hwang, Z. Guo and G. Lucey

Conventional solder materials are generally low temperature and low strength materials which are particularly vulnerable to temperature and stress. Even under ambient temperature…

32

Abstract

Conventional solder materials are generally low temperature and low strength materials which are particularly vulnerable to temperature and stress. Even under ambient temperature, 298±5°K, the homologous temperature of most soft solder compositions exceeds 0.5. It is therefore anticipated that the properties and behaviour of such solder compositions could alter significantly when they are exposed to temperature change, temperature rise and/or a moderate level of stresses. With the continued innovation and development of microelectronic packages along with the intense global competition, the reliability of solder joints and the quality and yield of making solder joints in production become increasingly important. This research is to address the fundamental material deficiencies of conventional solders in an effort to develop superior solder materials. Several material principles have been considered including both intrinsic material and soldering process approaches. This paper presents the preliminary results of strengthening effects from the intrinsic material approach. The soldering process effects will be presented in a separate paper. The strengthening effects were evaluated by the combined consideration of monotonic shearing, creep and isothermal low cycle fatigue tests. Fatigue fractography and microstructure of the strengthened solder were characterised in comparison with conventional 63Sn/37Pb solder. The results showed that the proprietary solder system possesses a higher monotonic flow resistance as cyclic frequency decreases to 10−4 Hz. Deformation mechanisms and fatigue failure modes are also discussed in this paper.

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

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Article
Publication date: 1 March 1992

A.J. Sunwoo, J.W. Morris and G.K. Lucey

The kinetics of wetting were studied on several different prepared surfaces of copper (Cu) to simulate the microstructure observed in pre‐tinned Cu‐clad printed circuit boards…

33

Abstract

The kinetics of wetting were studied on several different prepared surfaces of copper (Cu) to simulate the microstructure observed in pre‐tinned Cu‐clad printed circuit boards. The results illustrate the effectiveness of pre‐tinning in maintaining the solderability of Cu surfaces. Pre‐tinning with Pb‐rich solder (95Pb‐5Sn) is particularly effective since solderability is preserved even after a relatively long ageing treatment. On the other hand, pre‐tinning with eutectic solder risks the loss of solderability during ageing or baking due to surface exposure of an ε‐phase intermetallic with poor wetting properties. The results also confirm the presence of carbon in pre‐tinned specimens due to the use of flux. The effect of carbon on solderability is not yet known.

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

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Book part
Publication date: 13 September 2023

Ruopiao Zhang and Carlos Noronha

Drawing upon resource-based view (RBV) and attribution theoretical lenses, this chapter provides a paradigm for examining the interplay among environmental investment towards…

Abstract

Drawing upon resource-based view (RBV) and attribution theoretical lenses, this chapter provides a paradigm for examining the interplay among environmental investment towards green innovation, environmental disclosure as well as firm performance using the structural equation modelling (SEM) methodology. This chapter demonstrate a growing environmental awareness among stakeholders of the relevance of environmental performance to share value. It is also suggested that the mediating power of environmental disclosure between environmental investment and firm value as well as incremental goodwill is crucial. The findings of this chapter provide critical implications for several stakeholders that if environmental performance is hypothesised to affect the firm's value, companies may take proactive measures to avert potential environmental-related violations. Besides, investors may trade based on the evidence as to how firm value and its goodwill from acquisition will be affected by news of its environmental performance.

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Article
Publication date: 1 February 1995

P.S. Braterman, J.L. Marshall, J. Sees, C. Tan and J. Zhao

The unique advantages of confocal microscopy are used to explore four cases of interest: (i) voids in solder (depth and surface texture determined), (ii) steam vs ambient aged…

25

Abstract

The unique advantages of confocal microscopy are used to explore four cases of interest: (i) voids in solder (depth and surface texture determined), (ii) steam vs ambient aged solder coupons (significant differences detected), (iii) integrated circuit construction (sub‐surface contamination by µm‐size particles observed) and (iv) circuit boards and solder pads (non‐destructive optical sectioning through no‐wash flux layers). It is shown that confocal microscopy strongly complements SEM (scanning electron microscopy); SEM alone presents an incomplete description of a solder surface and in fact can sometimes produce misleading results.

Details

Soldering & Surface Mount Technology, vol. 7 no. 2
Type: Research Article
ISSN: 0954-0911

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Book part
Publication date: 4 April 2024

Thomas C. Chiang

Using a GED-GARCH model to estimate monthly data from January 1990 to February 2022, we test whether gold acts as a hedge or safe haven asset in 10 countries. With a downturn of…

Abstract

Using a GED-GARCH model to estimate monthly data from January 1990 to February 2022, we test whether gold acts as a hedge or safe haven asset in 10 countries. With a downturn of the stock market, gold can be viewed as a hedge and safe haven asset in the G7 countries. In the case of inflation, gold acts as a hedge and safe haven asset in the United States, United Kingdom, Canada, China, and Indonesia. For currency depreciation, oil price shock, economic policy uncertainty, and US volatility spillover, evidence finds that gold acts as a hedge and safe haven for all countries.

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Advances in Pacific Basin Business, Economics and Finance
Type: Book
ISBN: 978-1-83753-865-2

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Abstract

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Intersections of Financial Literacy, Citizenship, and Spirituality: Examining a Forbidden Frontier of Social Education
Type: Book
ISBN: 978-1-78973-631-1

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Article
Publication date: 1 December 1997

J.L. Marshall and J. Calderon

A series of composite solders in 63/37 Sn/Pb was prepared: Cu6 Sn5 (10, 20,30 wt%); Cu3 Sn (10, 20, 30 wt%); Cu (7.6 wt%); Ag (4 wt%); and Ni (4 wt%). These composite solders were…

493

Abstract

A series of composite solders in 63/37 Sn/Pb was prepared: Cu6 Sn5 (10, 20, 30 wt%); Cu3 Sn (10, 20, 30 wt%); Cu (7.6 wt%); Ag (4 wt%); and Ni (4 wt%). These composite solders were prepared by two procedures: (A) admixture with solder paste; and (B) admixture with molten solder. The original particulates and the final composite solders were analysed and characterised by SEM (scanning electron microscopy) EDX (energy dispersive X‐ray), and ESCA (electron spectroscopy for chemicals analysis); or XPS (X‐ray photoelectron spectroscopy). A variety of morphological characterisations, intermetallics and porosities were noted. Good wetting was noted in all cases, and porosity was greater for method (A). The particulates all exhibited excellent binding to the solder matrix.

Details

Soldering & Surface Mount Technology, vol. 9 no. 2
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 20 June 2022

Thomas C. Chiang

The purpose of this study is to present evidence as to whether the use of gold or silver can be justified as an asset to hedge against policy uncertainty and COVID-19 in the…

490

Abstract

Purpose

The purpose of this study is to present evidence as to whether the use of gold or silver can be justified as an asset to hedge against policy uncertainty and COVID-19 in the Chinese market.

Design/methodology/approach

By using a GARCH model with a generalized error distribution (GED), this study specifies that the gold (or silver) return is a function of a set of economic and uncertainty variables, which include volatility from interest rate innovation, a change in economic policy uncertainty (EPU), a change in geopolitical risk (GPR) and volatility due to pandemic diseases, while controlling for stock market returns, inflation rates, economic growth and the Chinese currency value.

Findings

This study employs monthly data of gold and silver prices over the period from January 2002 to August 2021 to examine hedging behavior. Estimated results show that the gold return is positively correlated to the stock return and a rise in uncertainty from economic policy innovation, geopolitical risk, volatility due to US interest rate innovation as well as COVID-19 infection. This result suggests that gold cannot be used to hedge against a stock market decline, but can be used to hedge against uncertainty in general. However, the silver return only responds positively to a rise in uncertainty from the inflation rate and geopolitical risk. Evidence shows that silver returns are negatively correlated with stock returns, and display hedging characteristics. However, the evidence lacks statistically significance during the COVID-19 period, suggesting that the role of silver as a safe-haven asset against stock market turmoil is weak for this time period.

Research limitations/implications

More general nonlinear specifications can be developed. The tests may include different measures of uncertainty that interact with each other or with the lagged error terms. An implication of the model is that gold can be used to hedge against a broad range of uncertainties for economic policy change, political risk and/or a pandemic. However, the use of gold as an asset to hedge against a stock downturn in Chinese market should be done with caution.

Practical implications

This study has important policy implications as regards a choice in assets in formatting a portfolio to hedge against uncertainty. Specifically, this study presents empirical evidence on gold and silver return behavior and finds that gold returns respond positively to heightened uncertainty. Thus, gold is a good asset to hedge against uncertainty arising from policy innovations and infectious disease uncertainty.

Social implications

This paper provides insightful information on the choice of assets toward hedging against risk in the uncertainty market conditions. It provides information to investors and policy makers to use gold price movements as a signal for detecting the arrival of uncertainty. This study also provides information for demanding a risk premium for infectious disease.

Originality/value

This study empirically analyzes and verifies the role that gold serves as a safe haven asset to hedge against uncertainty in the Chinese market. This paper contributes to the literature by presenting evidence of risk/uncertainty premiums for holding gold against various sources of uncertainty such as economic policy uncertainty, geopolitical risk and equity market volatility due to US interest rate innovation and/or COVID-19. This study finds evidence that supports the use of a nonlinear specification, which demonstrates the interaction of uncertainty with the lagged change of infectious disease and helps to explain the gold/silver return behavior. Further, evidence shows that the gold return is positively correlated to the stock return. This finding contrasts with evidence in the US market. However, silver returns are negatively correlated with stock returns, but this correlation becomes insignificant during the period of COVID-19.

Details

China Finance Review International, vol. 12 no. 4
Type: Research Article
ISSN: 2044-1398

Keywords

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