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1 – 10 of over 6000
Article
Publication date: 1 June 1999

Joseph Fjelstad

“A patterned arrangement of printed wiring utilizing flexible base material with or without flexible coverlayers”. The balance of this brief article will hopefully serve to help…

493

Abstract

“A patterned arrangement of printed wiring utilizing flexible base material with or without flexible coverlayers”. The balance of this brief article will hopefully serve to help the reader understand this remarkable interconnection technology and appreciate just how widely the technology can be applied.

Details

Circuit World, vol. 25 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 21 November 2008

Joseph Fjelstad

To provide an overview of a process for making proper selection of base materials for use in the manufacture of flexible circuits.

Abstract

Purpose

To provide an overview of a process for making proper selection of base materials for use in the manufacture of flexible circuits.

Design/methodology/approach

The paper provides an introductory review of the desirable attributes for flexible circuit substrates and includes a description of the attribute and its specific role and impact on the finished product.

Findings

The paper highlights the importance of making informed materials choices in flexible circuit manufacture. Flexible circuits are an increasingly important member of the family of electronic interconnection technologies and are also the fastest growing. A variety of materials can be used for flexible circuit construction, however, the choice must be tempered by the manufacturing and assembly processes and the application of the finished product.

Research limitations/implications

The paper provides a limited overview of the desirable properties of flexible circuit materials and is designed to provide initial background and guidance for making more informed decisions about material choices.

Originality/value

This paper provides an overview of the various factors that should be considered in advance of committing to a flex circuit design.

Details

Circuit World, vol. 34 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 May 2006

Markus Wille

Seeks to answer the question: have the reasons for using flex‐rigid circuit boards changed through the years?

Abstract

Purpose

Seeks to answer the question: have the reasons for using flex‐rigid circuit boards changed through the years?

Design/methodology/approach

The paper presents the development of flex‐rigid circuit board construction techniques from the first applications to the current status of a modern interconnection system. The paper discusses that it was the military and avionic industry that in the past required an interconnection technique that was reliable under environmental stress but compact and lightweight. Today it is the automotive and communication industry that is driving the development of printed circuit board technology.

Findings

Finds that wiring and interconnection must be cheap, reliable, light in weight, and must fit into very small housings. The demand for complex interconnection solutions like the flex‐rigid circuit technique is rising with the increased level of integration of more functions into electronic devices. The reasons for using flex‐rigid circuitries are nearly still the same as in the beginning.

Originality/value

Shows how the flex‐rigid circuit board technology has developed during the last 30 years.

Details

Circuit World, vol. 32 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 February 1986

S. Gazit

The increasing use of high switching speed systems in both microwave electronics and high speed logic devices has created the need for printed circuit boards which are based on…

Abstract

The increasing use of high switching speed systems in both microwave electronics and high speed logic devices has created the need for printed circuit boards which are based on low dielectric constant and low loss materials. In addition, these circuit materials must be capable of withstanding elevated temperatures typical of hostile service environments and of board fabrication processes. Such low dielectric constant rigid boards are commercially available from a few sources. However, there is a growing demand for low dielectric constant flexible printed circuit boards for interconnecting rigid boards or in rigid/flex applications where high speed, fast rise times, controlled impedance and low crosstalk are important. A new family of thin laminates which are suitable for fabrication of flexible low dielectric constant printed circuit boards have been developed by Rogers Corporation. These circuit materials are called ROhyphen;2500 laminates and offer flexible interconnections in high speed electronic systems. RO‐2500 circuit materials are based on microglass reinforced fluorocarbon composites and have a typical dielectric constant of 25. The transmission line properties of these materials have been evaluated by the IPC‐FC‐201 test method. The results indicated that these circuit materials improve the propagation velocity by about 10% and the rise time by about 30% when compared with the same geometry, polyimide film based, flexible PCs in stripline constructions. Also, dimensional stability of these laminates after etch and heat ageing is improved over that of the standard flex circuit materials based on polyimide film. RO‐2500 laminate properties have been evaluated by the IPC‐TM‐650 test methods, which are widely accepted by the flexible PCB industry.

Details

Circuit World, vol. 12 no. 3
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 1 January 1988

D. Avery

The paper attempts to describe the versatility of flex circuits and discusses how the component raw materials which are used in the manufacture of flexible laminates contribute to…

Abstract

The paper attempts to describe the versatility of flex circuits and discusses how the component raw materials which are used in the manufacture of flexible laminates contribute to this versatility. The focus of the paper is the range of copper foils available for flex circuit manufacture and a discussion of their properties and the metallurgical characteristics which govern these properties.

Details

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

Article
Publication date: 1 February 1987

T.H. Shepler

Flexible circuitry and flexible interconnects are high technology products that require a good understanding of flexible laminates and their properties to ensure the proper design…

Abstract

Flexible circuitry and flexible interconnects are high technology products that require a good understanding of flexible laminates and their properties to ensure the proper design of a functional part. Many designers use flexible interconnects for packaging and multiplane interconnections, but incorrectly compare flexible materials to rigid laminates. Flexible materials and design considerations when using flexible materials are reviewed, with a brief overview of the combination of flex and rigid materials in a flex/rigid multilayer circuit.

Details

Circuit World, vol. 13 no. 3
Type: Research Article
ISSN: 0305-6120

Article
Publication date: 14 March 2018

Alaaldeen Al-Halhouli, Hala Qitouqa, Abdallah Alashqar and Jumana Abu-Khalaf

This review paper aims to introduce the inkjet printing as a tool for fabrication of flexible/wearable sensors. It summarizes inkjet printing techniques including various modes of…

2510

Abstract

Purpose

This review paper aims to introduce the inkjet printing as a tool for fabrication of flexible/wearable sensors. It summarizes inkjet printing techniques including various modes of operation, commonly used substrates and inks, commercially available inkjet printers and variables affecting the printing process. More focus is on the drop-on-demand printing mode, a strongly considered printing technique for patterning conductive lines on flexible and stretchable substrates. As inkjet-printed patterns are influenced by various variables related to its conductivity, resistivity, durability and dimensions of printed patterns, the main printing parameters (e.g. printing multilayers, inks sintering, surface treatment, cartridge specifications and printing process parameters) are reported. The embedded approaches of adding electronic components (e.g. surface-mounted and optoelectronic devices) to the stretchable circuit are also included.

Design/methodology/approach

In this paper, inkjet printing techniques for fabrication of flexible/stretchable circuits will be reviewed. Specifically, the various modes of operation, commonly used substrates and inks and variables affecting the printing process will be presented. Next, examples of inkjet-printed electronic devices will be demonstrated. These devices will be compared to their rigid counterpart in terms of ease of implementation and electrical behavior for wearable sensor applications. Finally, a summary of key findings and future research opportunities will be presented.

Findings

In conclusion, it is evident that the technology of inkjet printing is becoming a competitor to traditional lithography fabrication techniques, as it has the advantage of being low cost and less complex. In particular, this technique has demonstrated great capabilities in the area of flexible/stretchable electronics and sensors. Various inkjet printing methods have been presented with emphasis on their principle of operation and their commercial availability. In addition, the components of a general inkjet printing process have been discussed in details. Several factors affect the resulting printed patterns in terms of conductivity, resistivity, durability and geometry.

Originality/value

The paper focuses on flexible/stretchable optoelectronic devices which could be implemented in stretchable circuits. Furthermore, the importance and challenges related to printing highly conductive and highly stretchable lines, as well as reliable electronic devices, and interfacing them with external circuitry for power transmission, data acquisition and signal conditioning have been highlighted and discussed. Although several fabrication techniques have been recently developed to allow patterning conductive lines on a rubber substrate, the fabrication of fully stretchable wearable sensors remains limited which needs future research in this area for the advancement of wearable sensors.

Details

Sensor Review, vol. 38 no. 4
Type: Research Article
ISSN: 0260-2288

Keywords

Article
Publication date: 1 June 1999

Ken Gilleo, Bob Boyes, Steve Corbett, Gary Larson and Dave Price

Polymer thick film (PTF) technology provides the lowest cost, cleanest and most efficient manufacturing method for producing flexible circuits. Non‐contact radio frequency (RF…

Abstract

Polymer thick film (PTF) technology provides the lowest cost, cleanest and most efficient manufacturing method for producing flexible circuits. Non‐contact radio frequency (RF) smart cards and related information transaction devices, such as RFID tags, appear to be a good fit for PTF‐flex. Flip chip also seems well suited for these “contactless” RF transceiver products. Flip chip and PTF adhesive technologies are highly compatible and synergistic. All PTF SMT adhesives assembly methods are viable for flip chip. However, the merging of flip chip with PTF‐flex presents major challenges in design, materials and processing. This paper will compare assembly methods and discuss obstacles and solutions for state‐of‐the‐art flip chip on flex within the RFID product environment.

Details

Circuit World, vol. 25 no. 2
Type: Research Article
ISSN: 0305-6120

Keywords

Article
Publication date: 1 June 2015

Konrad Futera, Konrad Kielbasinski, Anna Młozniak and Malgorzata Jakubowska

The purpose of this paper is to present the result of research on a new fabrication technology of printed circuits board and electronics modules. The new method is based on inkjet…

Abstract

Purpose

The purpose of this paper is to present the result of research on a new fabrication technology of printed circuits board and electronics modules. The new method is based on inkjet printing technique on flexible substrates using new generations of heterophase inks. New fabrications method was used to print microwave waveguides and signal splitters as new technology demonstrators.

Design/methodology/approach

A fully Inkjet printed filter was printed on a flexible, transparent Kapton foil using heterophase inks developed in Instytut Technologii Materiałów Elektronicznych (ITME) for the purpose of this research based on graphene and silver nanoparticles.

Findings

A microwave module was printed using two types of Inkjet printers – PixDro LP50 with KonicaMinolta 512 printhead – and developed in an Instytut Tele- i Radiotechniczny (ITR) laboratory printer using MicroDrop a 100-μm glass nozzle printhead. Fully printed microwave circuits were evaluated by their print quality and electrical properties.

Originality/value

Fully Inkjet printed microwave circuits using the heterophase graphene ink were evaluated by their print quality and electrical properties.

Details

Soldering & Surface Mount Technology, vol. 27 no. 3
Type: Research Article
ISSN: 0954-0911

Keywords

Article
Publication date: 2 November 2015

Fulian Qiu and David Harrison

Wearable electronic devices have emerged which require compact, flexible power storage devices such as batteries and supercapacitors. Recently, energy storage devices have been…

Abstract

Purpose

Wearable electronic devices have emerged which require compact, flexible power storage devices such as batteries and supercapacitors. Recently, energy storage devices have been developed based on supercapacitor threads. However, current supercapacitor energy storage threads which use electrolytes based on aqueous gels have a 1 V potential window. This is much lower than the voltage required by most electronic devices. This current contribution presents an approach for fabricating a multilayer supercapacitor working as a circuit unit, in which series combinations of the multiple layer structures can achieve a higher potential window, which can better meet the needs of wearable electronic devices.

Design/methodology/approach

Two-capacitive layer thread supercapacitors were fabricated using a semi-automatic dip coating method by coating two capacitive layers sequentially on a 50 μm stainless steel core wire, each capacitive layer includes ink, aqueous-based gel electrolyte and silver conductive paint layers.

Findings

Two capacitive layers of the single thread supercapacitor can work independently, or as combination circuits – parallel and series. Cyclic voltammograms showed that all flexible circuits have high electrochemical stability. For the case of series circuit configuration, with H3PO-polyvinyl alcohol (PVA) gel electrolyte, a working potential window of 2 V was achieved.

Originality/value

A flexible single thread supercapacitor of multilayer structure, with working voltage above 1 V in H3PO4-PVA gel electrolyte, has not been reported before. A semi-automatic dip coating setup used to process the thread supercapacitor has high potential for transfer to an industrial environment for mass production.

Details

Circuit World, vol. 41 no. 4
Type: Research Article
ISSN: 0305-6120

Keywords

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