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Article
Publication date: 31 July 2007

Winco K.C. Yung and Jijun Zhu

Low temperature co‐fired ceramics (LTCC) material is introduced as an excellent alternative to silicon, glass, or plastic materials for the fabrication of miniaturised analytical…

Abstract

Purpose

Low temperature co‐fired ceramics (LTCC) material is introduced as an excellent alternative to silicon, glass, or plastic materials for the fabrication of miniaturised analytical devices, though it is most widely used in the automotive and microwave industries. The paper aims to study the laser ablation of LTCC material.

Design/methodology/approach

This kind of green tape material is mechanised by excimer laser (KrF, 248 nm) and UV laser (Nd: YAG, 355 nm), and for the first time by infra‐red laser (1,090 nm). The optical photos and the scanning electronic microscope (SEM) photos of the LTCC ablated by different kinds of laser sources are given in this paper.

Findings

When using the UV laser, the tapered structure can be easily seen from the SEM photo. However, a kind of clear and perfect ablation of LTCC can be seen for the first time by the 1,090 nm infra‐red laser ablation.

Originality/value

The laser ablation of LTCC by optical fibre sources is discussed.

Details

Microelectronics International, vol. 24 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 September 1999

Winco K.C. Yung, J.S. Liu and H.C. Man

Diameter and depth of craters and removing efficiency of the material of RCCR (resin coated copper) used in PCB by a single pulse energy of 355nm YAG laser with a variety of pulse…

Abstract

Diameter and depth of craters and removing efficiency of the material of RCCR (resin coated copper) used in PCB by a single pulse energy of 355nm YAG laser with a variety of pulse energy, pulse width and defocus have been studied in the paper. It is shown that the ablation rates per pulse are much higher when compared with those at 248nm. The crater diameter increases monotonically with the pulse energy. However, when the pulse energy is very high and the power density is higher than 4.0 × 109W/cm2, the crater depth and removing efficiency decrease with the increase of pulse energy. The pulse width has an important influence on the crater diameter and volume when the pulse width changes from 24ns to 38ns, whereas the influence on the crater depth is little. The influences of defocus on ablation results depend on the power density of laser beam. A certain defocus can make both crater diameter and removing efficiency increase for a relatively high power density. Meanwhile, the thermal effect in the process of 355nm laser ablation of RCCR cannot be neglected.

Details

Circuit World, vol. 25 no. 3
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 February 1997

Winco K.C. Yung

Assesses the latest revisions to the ISO 9000 quality system, which seek to embrace the principles of total quality management (TQM) more closely. Highlights some of the TQM…

3180

Abstract

Assesses the latest revisions to the ISO 9000 quality system, which seek to embrace the principles of total quality management (TQM) more closely. Highlights some of the TQM elements introduced into the system, such as: quality improvement; management commitment with a greater emphasis on executive roles; operational processes showing linkages to the overall system; and customer satisfaction. Compares the advantages and disadvantages of the two systems and discusses the practicality of the revised ISO 9000 system as a highway to TQM.

Details

International Journal of Operations & Production Management, vol. 17 no. 2
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 1 March 2003

Winco Kam‐Chuen Yung and Danny Ting‐Hong Chan

The new management concept of flexible business process reengineering (FBPR) may be defined as a methodology that combines the best of three management tools – positioning…

2047

Abstract

The new management concept of flexible business process reengineering (FBPR) may be defined as a methodology that combines the best of three management tools – positioning, continuous improvement and business process reengineering (PIR). Employing all three management tools to a sufficient degree could enhance the effectiveness of an improvement project compared to the conventional BPR methodology. The changes could be slightly less “radical” than conventional BPR, but in exchange, it is a relatively less risky strategy and can facilitate continuous learning and improvement. To maximize the organization's competitiveness through the application of FBPR, it is important to establish a value delivery system (VDS) to increase the project's effectiveness and to employ performance benchmarking to determine the performance gap. Using a case study, this paper illustrates the essentiality and the application of VDS and performance benchmarking during the implementation of FBPR.

Details

International Journal of Operations & Production Management, vol. 23 no. 3
Type: Research Article
ISSN: 0144-3577

Keywords

Article
Publication date: 2 February 2015

Peter K. Bernasko, Sabuj Mallik and G. Takyi

The purpose of this paper is to study the effect of intermetallic compound (IMC) layer thickness on the shear strength of surface-mount component 1206 chip resistor solder joints…

1921

Abstract

Purpose

The purpose of this paper is to study the effect of intermetallic compound (IMC) layer thickness on the shear strength of surface-mount component 1206 chip resistor solder joints.

Design/methodology/approach

To evaluate the shear strength and IMC thickness of the 1206 chip resistor solder joints, the test vehicles were conventionally reflowed for 480 seconds at a peak temperature of 240°C at different isothermal ageing times of 100, 200 and 300 hours. A cross-sectional study was conducted on the reflowed and aged 1206 chip resistor solder joints. The shear strength of the solder joints aged at 100, 200 and 300 hours was measured using a shear tester (Dage-4000PXY bond tester).

Findings

It was found that the growth of IMC layer thickness increases as the ageing time increases at a constant temperature of 175°C, which resulted in a reduction of solder joint strength due to its brittle nature. It was also found that the shear strength of the reflowed 1206 chip resistor solder joint was higher than the aged joints. Moreover, it was revealed that the shear strength of the 1206 resistor solder joints aged at 100, 200 and 300 hours was influenced by the ageing reaction times. The results also indicate that an increase in ageing time and temperature does not have much influence on the formation and growth of Kirkendall voids.

Research limitations/implications

A proper correlation between shear strength and fracture mode is required.

Practical implications

The IMC thickness can be used to predict the shear strength of the component/printed circuit board pad solder joint.

Originality/value

The shear strength of the 1206 chip resistor solder joint is a function of ageing time and temperature (°C). Therefore, it is vital to consider the shear strength of the surface-mount chip component in high-temperature electronics.

Details

Soldering & Surface Mount Technology, vol. 27 no. 1
Type: Research Article
ISSN: 0954-0911

Keywords

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