Temperature Co-fired Ceramics Technology Research Articles

A review on wireless sensors fabricated using the low temperature co-fired ceramic (LTCC) technology

ABSTRACT In recent years, with the development of wireless communication systems and intelligent auxiliary equipment, the development of various wireless sensors has attracted more and more scientific and commercial attention. A new type of LC (Lenz (inductor) – Capacitor) wireless sensor was designed and fabricated using Low Temperature Co-fired Ceramics (LTCC) technology, including the advantages of low-cost wireless sensing of radio frequency (RF) communications and high operating temperature, miniaturisation, low weight, excellent thermal management, and multilayer printed circuit board of LTCC technology. LTCC technology offers functionalities such as high/low permittivity, low dielectric loss in a single multilayer package and multi-functional features by integration and interconnections. It also offers the highest interconnect density for the fabrication of 3D structures with multilayer additive fabrication of ceramic 2D sheets. In this article, an introduction to the LTCC technology and the mechanism of LC resonance wireless interrogation are overviewed. Then, we summarise the latest developments in wirelessgas, pressure, proximity and microfluidic sensors based on LTCC technology.

Low Temperature Co-fired Ceramics Plasma Generator for Atmospheric Pressure Gas Spectroscopy

Abstract Accurate and reliable measurements of gas composition are very important in science and industry applications. One way to accomplish this task is to measure spectrum of plasma gas discharge. In our work we propose integrated microcell for optical measurements of gas discharge at atmospheric pressure. This device is fabricated using Low Temperature Co-fired Ceramics (LTCC) technology. Investigated gas is excited in buried air-cavity, placed between two electrodes. Discharge is created using high alternating voltage (30 kV). Optical signal is then transmitted through an integrated optical fiber to the miniature spectrometer. Because different gases have different emission lines, plot of light intensity vs. wavelength provides information about molecular composition of the investigated gas sample. In this work, design, fabrication and performance of the LTCC- based gas discharge chamber is presented. Spectral measurements are performed for air, argon and nitrogen. Moreover, influence of gas flow rate on obtained emission spectrum is discussed.

Three axial low temperature cofired ceramic accelerometer

PurposeThe paper aims to present numerical modeling and technology of a very first three axial low temperature cofired ceramics (LTCC) accelerometer.Design/methodology/approachLow temperature cofired ceramics technology was applied in the fabrication process of the novel device. The numerical modeling was used to predict the properties of the accelerometer, moreover, design of the experiment methodology was used to reduce time of simulation and to get as much as information from the experiment as possible.FindingsThe low temperature cofired ceramics make it possible to fabricate three axial accelerometer.Research limitations/implicationsThe presented device is just a first prototype. Therefore, further research work will be needed to improve structural drawbacks and to analyze precisely the device reliability and parameters repeatability.Practical implicationsThe device presented in the paper can be applied in systems working in a harsh environment (high temperature and humidity). Ceramic sensors can withstand temperatures up to 600°C.Originality/valueThis paper presents novel three axial LTCC accelerometer.

Novel Tube-Type LTCC Transducers with Buried Heaters and Inner Electrodes for High-Temperatures Gas Sensors

Abstract In this work, a fully novel setup for high temperature gas sensor applications is presented. It consists of small tubular devices manufactured in Low Temperature Co-fired Ceramics (LTCC) Technology. It provides buried heaters and temperature sensors - all integrated in the tube - and interdigitated electrodes on the inner side of the tube. The sensitive film is also located inside of the tube, featuring an excellent homogenous temperature distribution on the sensitive film. As an example for a suitable application, a tubular dosimeter-type NO sensor for low level amount detection in varying gas velocities was developed.

A Study of Pressure Sensor for Environmental Monitoring

In this study, capacitive type pressure sensors based on low temperature co-fired ceramics (LTCC) technology for environmental monitoring were demonstrated. The LTCC is one of promising technology than is based one since it has many advantages (e.g., low cost production, high manufacturing yields and easy realizing 3D structure etc.) for sensor application. Especially, it has good mechanical and chemical properties for robust environmental application. The 3D LTCC diaphragm with thickness of 400 were fabricated by laminating 4 green sheets using commercial powder (NEG, MLS 22C). To evaluate the sensing properties of the different cavity areas, two types of diaphragm which had different cavity areas with 25, 49 respectively, were fabricated. To realize capacitive type pressure sensor, the Au top electrode was fabricated using thermal evaporator and the bottome electrode was compressed using aluminium foil. The sensing properties of the fabricated sensors showed linear characteristic under different pressure (0~30 psi) using pressure measurement system.

A Millimeter-Wave E-Plane Band-pass Filter using Multilayer Low Temperature Co-Fired Ceramic (LTCC) Technology

This paper presents a substrate integrated waveguide (SIW)-based millimeter-wave E-plane band-pass filter (BPF) with multilayer Low Temperature Co-fired Ceramic (LTCC) technology. The vertical metal walls of SIW and metal fins of the evanescent waveguides are realized by closely spacing metallic via-holes. A three-order Chebyshev E-plane BPF is developed and verified by full-wave simulation. The proposed filter is fabricated using LTCC technology, and a tapered line is designed as the transition between the SIW and microstrip line. Good agreement between simulated and measured results is observed.

LTCC Post Load Cell

This paper presents the development of a force post compressive load cell, fabricated using Low Temperature Cofired Ceramics (LTCC) technology. It was implemented as an LTCC mechanical load cell structure with a z-axis thick film strain gage using two different approaches. Fabrication methods and materials are explored in this work and fabricated devices are presented. This paper will also present the results of initial electromechanical sensitivity to load force and temperature tests. Compressive force behavior is consistent, in a strain level up to 1.500 micro-strain.