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Article
Publication date: 24 June 2020

Di Xie, Hui Chen, Siyi Yin, Feisen Wang, Jingwen Chen and Sifei Ai

Laser cleaning, as a new type of cleaning technology, has the advantages of environment-friendliness, better selectivity, better controllability and higher efficiency…

Abstract

Purpose

Laser cleaning, as a new type of cleaning technology, has the advantages of environment-friendliness, better selectivity, better controllability and higher efficiency compared to traditional chemical cleaning or grinding. This paper aims to use ultra-fast surface laser cleaning equipment built in laboratory to study the influence of different energy density (7.6, 11.5 and 15.3 J/cm2) on corrosion resistance of the aluminum alloy A7N01P-T4, a high-speed train body material.

Design/methodology/approach

SEM, white light interferometer, EDS and XPS were used to analyze the surface morphology, roughness, element content and oxide layer composition of aluminum alloy before and after cleaning. The corrosion resistance was studied by electrochemical experiments and exfoliation corrosion experiments.

Findings

The results showed that new oxide scale was formed on the surface after laser cleaning. The changes of surface roughness and chemical composition of oxide scale made a significant influence on corrosion behaviors. Better corrosion resistance was obtained with the energy density increased, and at the energy density of 11.5 J/cm2, aluminum alloy exhibited the best corrosion resistance.

Research limitations/implications

The paper only studies specific aluminum alloys and is not universal. Laser cleaning equipment is set up for the laboratory and has not yet been put into industrial production.

Practical implications

This paper indicated that ultra-fast laser processing was a new direction for the development of industrial equipment surface cleaning and carried out ultra-fast laser of aluminum alloy surface cleaning had certain research significance for its corrosion resistance.

Social implications

Compared with the conventional cleaning methods such as air abrasives grinding or chemical cleaning, laser cleaning has advantages of environment-friendliness, better selectivity, better controllability and higher efficiency. Laser cleaning can not only protect the environment, but also improve cleaning efficiency.

Originality/value

Changes in the surface of aluminum alloys after ultra-fast surface laser treatment were found, and the mechanism of changes in aluminum alloy corrosion properties was clarified.

Details

Anti-Corrosion Methods and Materials, vol. 67 no. 5
Type: Research Article
ISSN: 0003-5599

Keywords

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Article
Publication date: 1 February 1989

R. Rich

Cleaning or defluxing of populated printed circuit boards has become a very difficult problem as component stand‐off clearances have become smaller, line spacings tighter…

Abstract

Cleaning or defluxing of populated printed circuit boards has become a very difficult problem as component stand‐off clearances have become smaller, line spacings tighter, and solvents limited because of the CFC/ozone issue. This paper discusses the new technology of Centrifugal cleaning where ACCEL Energy™ is harnessed inside an enclosed chamber to provide significant cleaning benefits. Among these benefits are: superior washing, effective rinsing, superior drying, reduced solvent consumption by orders of magnitude, small footprint, and compatibility with H2O, saponifiers, chlorocarbons, fluorocarbons and terpenes.

Details

Circuit World, vol. 15 no. 3
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 1 April 1991

C. Lea

The options for eliminating CFC‐113 as a solvent for cleaning flux residues from soldered circuit assemblies, or minimising the need to clean, are now clear: diluted CFC…

Abstract

The options for eliminating CFC‐113 as a solvent for cleaning flux residues from soldered circuit assemblies, or minimising the need to clean, are now clear: diluted CFC solvent blends, new HCFC solvents, alcohols, water plus saponifier, water with water‐soluble flux, semi‐aqueous solvents, ‘no‐clean’ fluxes and controlled atmosphere soldering. This paper summarises the advantages and the limitations of each option and presents a methodology (first suggested by Northern Telecom) for ranking the options in a way that is specific to the requirements of the user. Both the cost and the technical feasibility of the implementation of each option are considered to provide a quantitative measure that can form the basis for the decision making ‘which option best fits my requirements and my resources?’

Details

Circuit World, vol. 18 no. 1
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 1 December 1996

R.S. Clouthier

SMT stencil cleaning has traditionally been thought of as a‘maintenance’ procedure with little or no impact on production. Today, CFC and VOCcleaning processes are being…

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Abstract

SMT stencil cleaning has traditionally been thought of as a ‘maintenance’ procedure with little or no impact on production. Today, CFC and VOC cleaning processes are being replaced because of environmental concerns, and fine‐pitch and ultra fine‐pitch assemblies are commonplace. These changes in cleaning processes and product specifications have shed new light on the importance of properly cleaning SMT screens and stencils in order to prevent damage to the stencil and potential production‐related problems.This paper takes an unbiased look at the different stencil cleaning processes available through the eyes of an SMT stencil manufacturer. The paper outlines the advantages and disadvantages of using ‘jet spray’ washersvs ‘ultrasonic’ washers, aqueous and semi‐aqueous vssolvent cleaning agents, and the effects of hot wash solutions and hot drying air vsambient wash solutions and drying techniques.Specific criteria evaluated include: cleaning effectiveness of the process; potential adverse effects of the process on the integrity of the stencil; production down‐time and other potential production‐related problems; potential health hazards to users; environmental impact of the process, and waste stream management.Magnified photography is used to demonstrate the relative effectiveness of various cleaning technologies. Third party references of other industry experts, along with the author's own experiences, are cited to support the information provided.

Details

Soldering & Surface Mount Technology, vol. 8 no. 3
Type: Research Article
ISSN: 0954-0911

Keywords

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Article
Publication date: 1 March 1988

D.A. Elliott

In August 1987, the EPA held a conference in Washington DC with consultants and users from the electronics industry to determine the feasibility of practical cleaning

Abstract

In August 1987, the EPA held a conference in Washington DC with consultants and users from the electronics industry to determine the feasibility of practical cleaning alternatives to reduce emissions of chlorofluorocarbon solvents which are considered to be a major contributor to the ozone problem in the stratosphere the world over. This paper presents a short resume of these goals and how they will affect cleaning in the electronics industry. Electronic design and packaging are the first steps in the soldering and cleaning processes. Selection of components compatible with alternative cleaning methods as well as process changes to permit low solids fluxes in some cases where cleaning can be eliminated will be discussed. ‘High containment’ in‐line solvent cleaning systems which reduce emissions are likely to become the new standard for the industry. Machines will become longer in order to include internal drying stages, instead of allowing a board with residual solvent trapped under components to evaporate after it leaves the machine prior to electronic test. Alternative solvents will become available. Designers of components and assemblies will respecify their designs to permit water cleaning, even for surface mount assemblies.

Details

Circuit World, vol. 14 no. 4
Type: Research Article
ISSN: 0305-6120

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Article
Publication date: 1 February 1991

P.‐E. Tegehall

The transition to surface mounted device (SMD) technology in electronics manufacturing has placed new demands on the post‐solder cleaning process. For spacecraft…

Abstract

The transition to surface mounted device (SMD) technology in electronics manufacturing has placed new demands on the post‐solder cleaning process. For spacecraft electronic systems it is of the utmost importance that all flux residues be removed. This paper reports the results of an investigation of the impact of component stand‐off heights and the distance between solder joints on the cleaning process efficiency. The capability to clean beneath large chip carriers was evaluated for four different cleaning methods using isopropanol or CFC‐113 (Freon TMS) as cleaning liquid. The results show that the cleaning efficiency decreases considerably if the stand‐off height is less than 240 µm for 100 mil pitch chip carriers. For 50 mil pitch chip carriers the stand‐off height needs to be greater than 240 µm to achieve high cleaning efficiency. The cleaning efficiency beneath chip carriers with small stand‐off heights can be increased by using ultrasonic cleaning. However, a very thin layer of white residues is left where the flux has been removed if isopropanol is used as the cleaning liquid.

Details

Soldering & Surface Mount Technology, vol. 3 no. 2
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 26 April 2013

Yap Boon Kar, Noor Azrina Talik, Zaliman Sauli, Foong Chee Seng, Tan Chou Yong and Vithyacharan Retnasamy

This paper aims to discuss the effects of ionic contaminations on the die surface of high lead flip chip ball grid array (FCBGA) package. Ionic contaminations from the…

Abstract

Purpose

This paper aims to discuss the effects of ionic contaminations on the die surface of high lead flip chip ball grid array (FCBGA) package. Ionic contaminations from the flux residue, formed during the die attachment process, could affect the package long‐term performance.

Design/methodology/approach

Thus, the flux‐cleaning process was implemented and the cleanliness effect was evaluated. Cleaning experiments using a new water‐based solvent were carried out to investigate the flux‐cleaning efficiency. The test packages were then evaluated via ion chromatography (IC).

Findings

Ion chromatograms show that there are high levels of ionic elements detected prior to the cleaning process. After the cleaning process, the contamination levels reduced significantly.

Originality/value

The value of the work here is testing of the new environmental friendly water‐based MPC® cleaning efficiency. The reduction of ionic contamination is thus reported.

Details

Microelectronics International, vol. 30 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

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Article
Publication date: 27 July 2021

Xiaokun Li and Xin Li

Autonomous mobile cleaning robots are widely used to clean solar panels because of their flexibility and high efficiency. However, gravity is a challenge for cleaning

Abstract

Purpose

Autonomous mobile cleaning robots are widely used to clean solar panels because of their flexibility and high efficiency. However, gravity is a challenge for cleaning robots on inclined solar panels, and robots have problems such as high working power and short battery life. This paper aims to develop a following robot to improve the working time and efficiency of the cleaning robot.

Design/methodology/approach

The mechanical structure of the robot is designed so that it can carry a large-capacity battery and continuously power the cleaning robot. The robot determines its position and orientation relative to the edge of solar panel by using optoelectronic sensors. Based on the following distance, the robot changes its state between moving and waiting to ensure that supply cable will not drag.

Findings

Prototype following robot test results show that the following robot can stably follow the cleaning robot and supply continuous power to cleaning robot. The linear error of the following robot moving along the solar panel is less than 0.3 m, and the following distance between the robot and the cleaning robot is in 0.5–1.5 m.

Practical implications

The working time of cleaning robots and working efficiency is improved by using following robot, thereby reducing the labor intensity of workers and saving the labor costs of cleaning.

Originality/value

The design of the following robot is innovative. Following robot works with the existing cleaning robots to make up for shortcomings of the existing cleaning system. It provides a more feasible and practical solution for using robots to clean solar panels.

Details

Industrial Robot: the international journal of robotics research and application, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0143-991X

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Article
Publication date: 1 March 1989

Joanna Eley

On the whole, commercial and public buildings regularly have their windows cleaned. For many of them, exterior cleaning stops there. But is exterior cleaning sufficiently…

Abstract

On the whole, commercial and public buildings regularly have their windows cleaned. For many of them, exterior cleaning stops there. But is exterior cleaning sufficiently important to receive part of an already tight facilities budget — perhaps at the expense of something more significant?

Details

Facilities, vol. 7 no. 3
Type: Research Article
ISSN: 0263-2772

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Article
Publication date: 1 March 1984

Cleaning costs represent 6 per cent of total building occupancy costs (excluding rent and rates) as our month by month Economic review pie charts showed. A massive 40 per…

Abstract

Cleaning costs represent 6 per cent of total building occupancy costs (excluding rent and rates) as our month by month Economic review pie charts showed. A massive 40 per cent of those cleaning costs may be attributed to floor cleaning (Facilities 1/2 p5) — a significant portion of the costs in use of the building and one that merits detailed analysis.

Details

Facilities, vol. 2 no. 3
Type: Research Article
ISSN: 0263-2772

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