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Article
Publication date: 1 August 2016

Hongyan Shi, Qiuxin Yan and Shengzhi Chen

The purpose of this paper is to study the movement characteristics of micro drill bit during entry period in printed circuit board (PCB) high-speed drilling and to present an…

Abstract

Purpose

The purpose of this paper is to study the movement characteristics of micro drill bit during entry period in printed circuit board (PCB) high-speed drilling and to present an effective method to conduct quantitative analysis of the wandering of drill bit based on high-speed video capturing.

Design/methodology/approach

Based on the high-speed camera technology, experiments are conducted to get a series of time sequence images and the wandering of micro drill tip and the radial run-out of drill body, and the max-deformation of drill bit are calculated by using a quantitative analysis method. Finally, the movement characteristics of micro drill bit during entry drilling period PCB high-speed drilling are evaluated.

Findings

With the increasing spindle speed, the radial run-out of drill body decreases gradually, whereas the wandering amplitude of the drill point gradually increases; micro drill bit itself has an ability of positioning deviation correction after contacting the entry sheet; the feed rate within a certain range could slightly worsen the deformation of drill tip at the instant of impingement.

Research limitations/implications

With the improvement of spindle speed, the camera’s shooting speed needed will increase accordingly, thus, the resolution of the pictures will decline, which always affects the analysis precision.

Originality/value

A series of effective methods to conduct quantitative analysis of the wandering micro drill bit by using high-speed camera technology is presented; a reference for the optimization of micro-hole drilling is provided.

Details

Circuit World, vol. 42 no. 3
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 9 January 2020

Shengzhi Chen, Minghua Zhu, Qing Zhang, Xuesong Cai and Bo Xiao

The differential magnetic gradient tensor system is usually constructed from the three-axis magnetic sensor array. While the effects of measurement error, sensor performance and…

Abstract

Purpose

The differential magnetic gradient tensor system is usually constructed from the three-axis magnetic sensor array. While the effects of measurement error, sensor performance and baseline distance on localization performance of such systems have been widely reported, the research about the effect of spatial design of sensor array is less presented. This paper aims to provide a spatial design method of sensor array and corresponding optimization strategy to localization based on magnetic tensor gradient to get the optimum design of the sensor array. Based on the results of simulation, magnetic localization systems constructed from the proposed array and the traditional array have been built to carry out a localization experiment. The results of experiment have verified the effectiveness of magnetic localization based on the proposed array.

Design/methodology/approach

The authors focus on the localization of the magnetic target based on magnetic gradient by using three-axis magnetic sensor array and combine a design method with corresponding optimization strategy to get the optimum design of the sensor array.

Findings

This paper provides an array design and optimization method for magnetic target localization based on magnetic gradient to improve the localization performance.

Originality/value

In this paper, the authors focus on the magnetic localization based on magnetic gradient by using three-axis magnetic sensors and study the effect of the spatial design of sensor array on localization performance.

Details

Sensor Review, vol. 40 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 2 February 2015

Hongyan Shi, Hui Li and Shengzhi Chen

The purpose of this paper is to obtain the micro drill bit temperature field distribution in micro-drilling process and the temperature drop in retracting process with simulation…

Abstract

Purpose

The purpose of this paper is to obtain the micro drill bit temperature field distribution in micro-drilling process and the temperature drop in retracting process with simulation software. Meanwhile, the key factors that affect the micro drill bit temperature will be obtained as well. The results can also be used to improve the accuracy in on-line drilling temperature measurement.

Design/methodology/approach

The purpose of this paper is to obtain the micro drill bit temperature field distribution in micro-drilling process and the temperature drop in retracting process with simulation software. Meanwhile, the key factors that affect the micro drill bit temperature will be obtained as well. The results can also be used to improve the accuracy in on-line drilling temperature measurement.

Findings

Micro drill bit high-temperature area mainly concentrates in the cutting edge and chisel edge. With the increase of spindle speed and feed speed, the micro drill bit highest temperature increased. The micro drill bit temperature drop rate reaches 20° in the micro-drilling retraction process with certain parameters. The micro drill bit highest temperature detected by an infrared camera is lower by 22° than that in real drilling. The simulation results can be used to guide the actual industrial production.

Originality/value

The simulation results can be applied to revise the temperature measurement by an infrared camera in the drilling process. Drilling experiments show that the simulation method is correct and has certain practical significance. The current temperature measurement method can satisfy most of the requirements of temperature measurements.

Details

Circuit World, vol. 41 no. 1
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 January 2009

Li Genpan

The purpose of this paper is to demonstrate that the sustainable development thought is one good reason why Chinese civilization is continuously developing, and it can be used as…

2901

Abstract

Purpose

The purpose of this paper is to demonstrate that the sustainable development thought is one good reason why Chinese civilization is continuously developing, and it can be used as a reference for the development of Chinese agriculture today.

Design/methodology/approach

The paper employs a historical analysis approach to examine the sustainable thoughts concerning Chinese traditional agriculture, including view of sancai, farming season, fertility, the nature of matters, recycling, and economization.

Findings

The results reveal that the nature of Chinese traditional agriculture is akin to ecological agriculture, which is precious heritage for China and the whole world.

Originality/value

The originality of this paper is that it confirms the fundamental reason of the continuous development of Chinese civilization which, based on organization of sustainable development thought, lies in traditional agriculture.

Details

China Agricultural Economic Review, vol. 1 no. 1
Type: Research Article
ISSN: 1756-137X

Keywords

Book part
Publication date: 12 November 2016

Falin Zhang

Propose a more comprehensive explanation on the determinants and fluctuations of China’s exchange rate policy in the past decade (2005–2015).

Abstract

Purpose

Propose a more comprehensive explanation on the determinants and fluctuations of China’s exchange rate policy in the past decade (2005–2015).

Approach

Case study on China’s exchange rate policies in three respective stages since 2005 and then a comparative study on these three stages.

Findings

Put forward a two-pronged explanation on the determinants and fluctuations of China’s exchange rate policy in the past decade and arrive at three specific conclusions. First, external pressure is only one factor among many influencing the formation of China’s national interests (Guojia Liyi in Chinese) and the decision-making process on exchange rate policy. Second, national interest is the fundamental driving force and substratum for making China’s exchange rate policy. Third, in the short term, the specific exchange rate policies in different periods were not always in accordance to the national interests (or Guojia Liyi), due to the influences of some factors on the decision-making environment.

Value

The comprehensive view is conducive to better explaining the formation and fluctuations of China’s exchange rate policy and consequently contributes to understanding and even predicting future policies.

Details

The Political Economy of Chinese Finance
Type: Book
ISBN: 978-1-78560-957-2

Keywords

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