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Article

J. Heilala, K. Keränen, J.‐T. Mäkinen, O. Väätäinen, K. Kautio, P. Voho and P. Karioja

The aim of the research was to evaluate the concept that utilizes structured planar substrates based on low temperature co‐fired ceramics (LTCC) as a precision platform…

Abstract

Purpose

The aim of the research was to evaluate the concept that utilizes structured planar substrates based on low temperature co‐fired ceramics (LTCC) as a precision platform for the passive alignment of a multimode fiber and wide‐stripe diode laser.

Design/methodology/approach

Presents the manufacturing process for realisation of 3D precision structures, heat dissipation structures and a cooling channel into the LTCC substrate. The developed methodology for 3D modelling and simulation of the system was used to optimize structures, materials and components in order to achieve optimal performance for the final product and still maintain reasonably low fabrication costs. The simulated optical coupling efficiency and alignment tolerances were verified by prototype realization and characterization.

Findings

The achieved passive alignment accuracy allows high coupling efficiency realisations of multimode fiber pigtailed laser modules and is suitable for mass production.

Research limitations/implications

Provides guidance in the design of LTCC precision platforms for passive alignment and presents a hybrid simulation method for photonics module concept analysis.

Practical implications

The three‐dimensional shape of the laminated and fired ceramic substrate provides the necessary alignment structures including holes, grooves and cavities for the laser to fiber coupling. Thick‐film printing and via punching can be incorporated in order to integrate electronic assemblies directly into the opto‐mechanical platform.

Originality/value

Introduces the LTCC 3D precision structures for photonics modules enabling passive alignment of multimode fiber pigtailed laser with high efficiency optical coupling. Demonstrates the hybrid simulation methodology for concept analysis.

Details

Assembly Automation, vol. 25 no. 1
Type: Research Article
ISSN: 0144-5154

Keywords

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Article

Darko Belavič, Marko Hrovat , Kostja Makarovič , Gregor Dolanč, Andrej Pohar , Stanko Hočevar and Barbara Malič

– The purpose of this paper is to present the research activity and results to research and development society on the field of ceramic microsystems.

Abstract

Purpose

The purpose of this paper is to present the research activity and results to research and development society on the field of ceramic microsystems.

Design/methodology/approach

The chemical reactor was developed as a non-conventional application of low temperature co-fired ceramic (LTCC) and thick-film technologies. In the ceramic reactor with a large-volume, buried cavity, filled with a catalyst, the reaction between water and methanol produces hydrogen and carbon dioxide (together with traces of carbon monoxide). The LTCC ceramic three-dimensional (3D) structure consists of a reaction chamber, two inlet channels, an inlet mixing channel, an inlet distributor, an outlet collector and an outlet channel. The inlet and outlet fluidic barriers for the catalyst of the reaction chamber are made with two “grid lines”.

Findings

A 3D ceramic structure made by LTCC technology was successfully designed and developed for chemical reactor – methanol decomposition.

Research limitations/implications

Research activity includes the design and the capability of materials and technology (LTCC) to fabricate chemical reactor with large cavity. But further dimensions-scale-up is limited.

Practical implications

The technology for the fabrication of LTCC-based chemical reactor was developed and implemented in system for methanol decomposition.

Originality/value

The approach (large-volume cavity in ceramic structure), which has been developed, can be used for other type of reactors also.

Details

Microelectronics International, vol. 32 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

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Article

Jaroslaw Kita, Andrzej Dziedzic, Leszek J. Golonka and Tomasz Zawada

This paper presents possibility of laser application for fabrication of 3D elements and structures. The Aurel NAVS‐30 Laser Trimming and Cutting System with special…

Abstract

This paper presents possibility of laser application for fabrication of 3D elements and structures. The Aurel NAVS‐30 Laser Trimming and Cutting System with special software was used. It was applied successfully for fabrication of vias (minimum diameter – 50 μm) in fired and unfired LTCC ceramics and channels with width between 100 μm and 5 mm. The achievements and problems are presented and discussed. The influence of lamination process on quality of vias and channels as well as the problems connected with interaction of laser beam with ceramic tapes are shown. Three‐dimensional resistors and microfluidic system were successfully designed and fabricated based on our investigations. Chosen electrical and thermal parameters of constructed devices are shown, too.

Details

Microelectronics International, vol. 19 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

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Article

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…

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

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Article

Edward Miś, Andrzej Dziedzic, Tomasz Piasecki, Jarosław Kita and Ralf Moos

Capacitors are frequently used in electronic circuits. Thick‐film technology allows fabrication of such components in the case of small‐ and medium‐capacitance values…

Abstract

Purpose

Capacitors are frequently used in electronic circuits. Thick‐film technology allows fabrication of such components in the case of small‐ and medium‐capacitance values. They can also be manufactured in LTCC structures. The paper seeks to investigate the electrical properties of thick‐film and LTCC capacitors for as‐fired and long‐term thermally aged test structures in a wide frequency and temperature range.

Design/methodology/approach

Sandwich and interdigitated planar capacitors were fabricated on alumina or LTCC substrates using standard screen printing and laser shaping. Various dielectric inks and electrodes materials were used. The crystalline phases in thick‐film dielectric films were identified.

Findings

Planar and sandwich LTCC and thick‐film capacitors were designed and fabricated. Different technology variations were tested. X‐ray analysis indicated that both used commercial compositions, compatible with LTCC substrates are based on barium and titatium compounds. The difference in their dielectric constants probably are related with kind of crystalline phases, presented in these compositions and crystalline phase/glass ratio.

Originality/value

This paper presents results of investigations made on thick‐film and LTCC microcapacitors.

Details

Microelectronics International, vol. 25 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

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Article

Marina Santo Zarnik, Darko Belavič and Srečko Maček

The purpose of this paper is to consider a capacitive pressure sensor fabricated using low‐temperature cofired ceramic (LTCC) materials and technology as a candidate for…

Abstract

Purpose

The purpose of this paper is to consider a capacitive pressure sensor fabricated using low‐temperature cofired ceramic (LTCC) materials and technology as a candidate for an energy‐autonomous sensor application. Designing the 3D capacitive sensor structure, with the cofired thick‐film electrodes inside the narrow air gap in the LTCC substrate, was a challenging task, particularly due to the presence of the parasitic elements influencing the sensor's characteristics.

Design/methodology/approach

In this work, different design variants for the thick‐film electrodes of the capacitive sensing structure were studied and compared. The test sensors were designed for the pressure range 0‐10 kPa and manufactured with readout electronics based on a capacitance‐to‐digital conversion.

Findings

The typical sensitivity obtained was 4 fF/kPa, and the temperature coefficient of the sensitivity was 0.03%/°C. The design variant with the guard‐ring electrode showed the best rms resolution of 50 Pa. One drawback of the application could be the sensitivity to atmospheric humidity and the influence of the different media.

Originality/value

This paper focuses on the design of a capacitive gas‐pressure sensor in a 3D LTCC structure. The present study provides a good basis for further optimisation of the design of the cofired electrodes in the capacitive sensing structure.

Details

Microelectronics International, vol. 28 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

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Article

Darko Belavic, Andraž Bradeško and Hana Uršič

The purpose of this study is to design, fabricate and investigate low-temperature co-fired ceramic (LTCC) structures with integrated microfluidic elements. Special…

Abstract

Purpose

The purpose of this study is to design, fabricate and investigate low-temperature co-fired ceramic (LTCC) structures with integrated microfluidic elements. Special attention is paid to the study of fluid properties of micro-channels and microvalves, which are important constitutive parts of both, microfluidic systems and individual microfluidic devices.

Design/methodology/approach

Several test patterns of fluid channels with different geometry and different types of valves were designed and realized in LTCC technology. All test structures were tested under the flow of two fluids (liquids): water and isopropyl alcohol. Flow rates at different applied pressure were measured and hydrodynamic resistance and diode effect were calculated.

Findings

The investigation of the channels showed that viscosity of fluidic media has significant influence on the hydrodynamic resistance in channels with rectangular cross-section, while this effect is small on channels with square cross-section. The viscosity also has a decisive influence on the diode effect of different shape of valves, and therefore, it is important in the selection of the valve in practical applications.

Research limitations/implications

In this work, the investigation of hydrodynamic resistance of channels and diode effect of passive valves is limited on selected geometry and only on two fluidic media and two applied pressures. All these and some other parameters have a significant influence on fluidic properties, but this will be the topic of the next research work, which will be supported by numerical modelling.

Practical implications

The presented results are useful in the future designing process of LTCC-based microfluidic devices and systems.

Originality/value

Microfluidic in the LTCC structures is an unconventional use of this technology. Therefore, the fluid properties are relatively unsearched. On the other hand, the global use of microfluidic devices and systems is growing rapidly in various applications. They are mostly made by polymer materials, however, in more demanding applications; ceramic is a useful alternative.

Details

Microelectronics International, vol. 35 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

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Article

Marina Santo Zarnik, Darko Belavic and Srecko Macek

The successful use of piezoceramic thick films in sensors and actuators requires a thorough understanding of their electrical and electromechanical characteristics. Since…

Abstract

Purpose

The successful use of piezoceramic thick films in sensors and actuators requires a thorough understanding of their electrical and electromechanical characteristics. Since these characteristics depend not only on the material's composition but also on its compatibility with various substrates and a number of processing parameters, accurate measurements of the material's parameters are essential. Here, the aim of this paper is to present a procedure for characterising lead‐zirconate‐titanate (PZT) thick films on pre‐fired low‐temperature co‐fired ceramic (LTCC) substrates performed in order to determine the material parameters for numerical modelling.

Design/methodology/approach

Owing to the lack of standard procedures for measuring the elastic and piezoelectric properties of the films, the compliance parameters were evaluated from the results of nano‐indentation tests, and a substrate‐flexure method was used to evaluate the transverse piezoelectric coefficients.

Findings

The validation of the material model and the finite‐element (FE) analysis of the demonstrator sensor/actuator structures are shown to be in agreement with the FE model, even if not an exact fit.

Originality/value

This paper focuses on a characterisation of PZT thick films screen‐printed on pre‐fired LTCC substrates.

Details

Microelectronics International, vol. 25 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

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Article

Kostja Makarovič, Darko Belavič, Barbara Malič, Andreja Benčan, Franci Kovač and Janez Holc

The purpose of this study is the design, fabrication and evaluation of a miniature ozone generator using the principle of electric discharge are presented.

Abstract

Purpose

The purpose of this study is the design, fabrication and evaluation of a miniature ozone generator using the principle of electric discharge are presented.

Design/methodology/approach

The device was fabricated using a low-temperature co-fired ceramics (LTCC) technology, by which a multilayered ceramic structure with integrated electrodes, buried channels and cavities in micro and millimeter scales was realized.

Findings

The developed ozone generator with the dimensions of 63.6 × 41.8 × 1.3 mm produces approximately 1 vol. % of ozone in oxygen flow of 15 ml/min, at an applied voltage of 7 kV.

Originality/value

A miniature ozone generator, manufactured in LTCC technology, produces high amount of ozone and more than it is described in the available references or in datasheets of commercial devices of similar size.

Details

Microelectronics International, vol. 38 no. 1
Type: Research Article
ISSN: 1356-5362

Keywords

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Article

Arkadiusz Dabrowski, Przemyslaw Rydygier, Mateusz Czok and Leszek Golonka

The purpose of this study was to design, fabricate and test devices based on transformers integrated with low-temperature co-fired ceramic (LTCC) modules with isolation…

Abstract

Purpose

The purpose of this study was to design, fabricate and test devices based on transformers integrated with low-temperature co-fired ceramic (LTCC) modules with isolation between primary and secondary windings at the level between 6 and 12 kV.

Design/methodology/approach

Insulating properties of the LTCC were examined. Dielectric strength and volume resistivity were determined for common LTCC tapes: 951 (DuPont), 41020, 41060 (ESL), A6M (Ferro) and SK47 (KEKO). According to the determined properties, three different devices were designed, fabricated and tested: a compact DC/DC converter, a galvanic separator for serial digital bus and a transformer for high-voltage generator.

Findings

Breakdown field intensity higher than 40 kV/mm was obtained for the test samples set, whereas the best breakdown field intensity of about 90 kV/mm was obtained for 951 tape. The materials 41020 and 951 exhibited the highest volume resistivity. Fabricated devices exhibited safe operation up to a potential difference of 10 kV, limited by minimum clearance. Long-term stability was assured by over 20 kV strength of inner dielectric.

Practical implications

This paper contains description of three devices made in the LTCC technology for application in systems with high-voltage isolation requirement, for example, for power or railway power networks.

Originality/value

The results show that LTCC is a suitable material for fabrication of high-voltage devices with integrated passives. Technology and properties of three examples of such devices are described, demonstrating the ability of the LTCC technology for application in reliable high-voltage devices and systems.

Details

Microelectronics International, vol. 35 no. 3
Type: Research Article
ISSN: 1356-5362

Keywords

1 – 10 of 55