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1 – 5 of 5Low temperature co‐fired ceramics (LTCC) material is introduced as an excellent alternative to silicon, glass, or plastic materials for the fabrication of miniaturised…
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.
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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…
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.
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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…
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.
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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 …
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.
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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…
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.
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