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Abstract

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Circuit World, vol. 30 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

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33

Abstract

Details

Circuit World, vol. 30 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 April 1999

Michael Chalsen and Daniel Crowley

Microwave modules and hybrid circuits have some unique requirements that demand extremely precise dispensing and placement, delicate handling and well controlled curing…

Abstract

Microwave modules and hybrid circuits have some unique requirements that demand extremely precise dispensing and placement, delicate handling and well controlled curing (or reflow). Assembly of these products can be challenging and defects may result in labor‐intensive manual assembly methods. A better way is to apply automated manufacturing techniques to the assembly of microwave modules and hybrid circuits and thereby eliminate many of the variables that may narrow the process window.

Details

Microelectronics International, vol. 16 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 April 1981

Peter J. Neagle and Thomas D. Newton

In attempts to meet the need for low‐loss materials capable of attaining the dielectric properties that are required for rapidly developing microwave and high speed…

Abstract

In attempts to meet the need for low‐loss materials capable of attaining the dielectric properties that are required for rapidly developing microwave and high speed digital equipment, polysulphone in its various forms has been undergoing investigation. Microwave dielectric properties are examined with respect to temperature and frequency, and three types of polysulphone are studied in depth, with testing for dielectric constant and dissipation factor. The material's physical properties are listed prior to advisory comments on special processing requirements. Its feasibility in multilayer production is currently being researched.

Details

Circuit World, vol. 8 no. 1
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 3 July 2007

T. Tilford, K.I. Sinclair, C. Bailey, M.P.Y. Desmulliez, G. Goussettis, A.K. Parrott and A.J. Sangster

This paper aims to present an open‐ended microwave curing system for microelectronics components and a numerical analysis framework for virtual testing and prototyping of…

Abstract

Purpose

This paper aims to present an open‐ended microwave curing system for microelectronics components and a numerical analysis framework for virtual testing and prototyping of the system, enabling design of physical prototypes to be optimized, expediting the development process.

Design/methodology/approach

An open‐ended microwave oven system able to enhance the cure process for thermosetting polymer materials utilised in microelectronics applications is presented. The system is designed to be mounted on a precision placement machine enabling curing of individual components on a circuit board. The design of the system allows the heating pattern and heating rate to be carefully controlled optimising cure rate and cure quality. A multi‐physics analysis approach has been adopted to form a numerical model capable of capturing the complex coupling that exists between physical processes. Electromagnetic analysis has been performed using a Yee finite‐difference time‐domain scheme, while an unstructured finite volume method has been utilized to perform thermophysical analysis. The two solvers are coupled using a sampling‐based cross‐mapping algorithm.

Findings

The numerical results obtained demonstrate that the numerical model is able to obtain solutions for distribution of temperature, rate of cure, degree of cure and thermally induced stresses within an idealised polymer load heated by the proposed microwave system.

Research limitations/implications

The work is limited by the absence of experimentally derived material property data and comparative experimental results. However, the model demonstrates that the proposed microwave system would seem to be a feasible method of expediting the cure rate of polymer materials.

Originality/value

The findings of this paper will help to provide an understanding of the behaviour of thermosetting polymer materials during microwave cure processing.

Details

Soldering & Surface Mount Technology, vol. 19 no. 3
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 1 March 2003

C. Fitzpatrick, P. Mavromatidis, E. Lewis, J. Lucas and A. Al‐Shamma'a

This paper investigates the feasibility of using the emission intensity of low‐pressure argon and nitrogen gas discharges as the sensing mechanism for a microwave electric…

Abstract

This paper investigates the feasibility of using the emission intensity of low‐pressure argon and nitrogen gas discharges as the sensing mechanism for a microwave electric field optical sensor probe in microwave resonant cavities. The emission is coupled to a photodiode for detection through an optical fibre due to the difficulty in using conventional optoelectronic devices in close proximity to microwave cavities. The discharge emission intensity is monitored at a range of different input powers to the cavity. The proposed designs for the electric field sensing probe are also included.

Details

Sensor Review, vol. 23 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 1 January 1984

P.E. Ongley

The paper briefly reviews the problems associated with resin smear in the manufacture of multilayer boards, the various types of material involved, and their influence on…

42

Abstract

The paper briefly reviews the problems associated with resin smear in the manufacture of multilayer boards, the various types of material involved, and their influence on smear, and some of the techniques available for assessing the degree of smear. Following a short discussion on current methods of removing smear, the paper goes on to provide a critical comparison of traditional ‘wet’ chemical processes with the newer ‘dry’ plasma techniques. Key advantages of plasma desmearing are highlighted and the paper concludes with a more detailed description of the I V Products approach and current systems, together with results of recent development work.

Details

Circuit World, vol. 10 no. 2
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 January 1988

M. Huschka

The new military specification for PCB base material was published on February 11th, 1987. This ‘G’ version is not merely an amendment of the ‘F’ version, but basically a…

Abstract

The new military specification for PCB base material was published on February 11th, 1987. This ‘G’ version is not merely an amendment of the ‘F’ version, but basically a new specification with far reaching consequences for both the base material manufacturers and the printed circuit board manufacturers. In this paper the major changes and also the latest introductions are discussed.

Details

Circuit World, vol. 14 no. 2
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 7 January 2021

Fatma Bakal, Ahmet Yapici, Muharrem Karaaslan and Oğuzhan Akgöl

The purpose of this paper is to investigate the effect of doping element on the microwave absorption performance of hexagonal nano boron nitride (h-nBN)-reinforced basalt…

Abstract

Purpose

The purpose of this paper is to investigate the effect of doping element on the microwave absorption performance of hexagonal nano boron nitride (h-nBN)-reinforced basalt fabric (BF)/epoxy composites. A new type of hybrid composite that will be produced by the use of boron nitride as an additive that leads to increased radar absorption capability will be developed and a new material that can be used in aeronautical radar applications.

Design/methodology/approach

This study is focused on the microwave absorption properties of h-nBN doped basalt fabric-reinforced epoxy composites. Basalt fabric (BF)/epoxy composites (pure composites) and the BF/h-nBN (1 Wt.% h-nBN doped composites) hybrid composites were fabricated by vacuum infusion method. Phase identification of the composites were performed using X-ray diffraction (XRD), the 2θ scan range was from 10 to 60 with the scanning speed of 3°/min and surface morphologies of the composites were investigated using scanning electron microscopy (SEM). Microwave properties of samples were investigated through transmission/reflection measurements in Agilent brand 2-Port PNA-L Network Analyzer in the frequency range of 3–18 GHz. The prepared sample is positioned between two horn antennas with and without metal plate.

Findings

Experimental results show that h-nBN doped composite was synthesized successfully and the produced hexagonal nano boron nitride-added fiber laminated composite material has good absorption behavior when they are used with metallic sheets and good for isolation applications at many points in the 3–18 GHz band.

Originality/value

This paper will contribute to the literature on the use of basalt fabric, which are new types of fibers, and hexagonal nano boron nitride and the effects of boron nitride on radar absorption properties of composite material. It presents detail characterization of each composite by using XRD and scanning electron microscopy.

Details

Aircraft Engineering and Aerospace Technology, vol. 93 no. 1
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 7 May 2021

Satish Geeri and Aditya Kolakoti

The purpose of the present work is to fabricate composite with strong absorbing nature and with more strength. The usage of wireless communication is increasing day by…

Abstract

Purpose

The purpose of the present work is to fabricate composite with strong absorbing nature and with more strength. The usage of wireless communication is increasing day by day, electromagnetic absorbing material is required to reduce this pollution. In the present experimental investigation, composites were fabricated for zero and 45° fiber orientation and as a filler material of Multiwall Carbon Nanotubes (MWCNTs) for the proposed percentage in the composites. Microwave absorbing properties were investigated for both perfect electric conductor (PEC)-backed composites and without PEC-backed composites.

Design/methodology/approach

The electromagnetic absorbing performance was analyzed based on complex permeability, complex permittivity, dielectric tangent and magnetic tangent losses. The experimentation was done by Vector Network Analyzer in the frequency range of 8.2 to 12.4 GHz by X-band. The surface morphological study was done. The mechanical and thermal properties are also investigated for these composites.

Findings

By investigating the experimental values, the induced percentage of MWCNTs and PEC of composites affects the electromagnetic and microwave absorption properties of the composites. The microwave absorption properties improved when the composites were able to absorb wide bandwidth and low reflection loss. The best results are obtained for PEC-backed composites for 5%, which is about −43.56 dB at 11.1 GHz compared to without PEC-backed composites. The reflection loss is developed by the dielectric loss initiated from MWCNTs and by PEC.

Originality/value

To the best of the authors’ knowledge, no work was reported on hand lay-up method and PEC-backed composites in electromagnetic absorption properties with regression analysis.

Details

World Journal of Engineering, vol. 18 no. 6
Type: Research Article
ISSN: 1708-5284

Keywords

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