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1 – 10 of 450Rabindra N. Das, Frank D. Egitto and Voya R. Markovich
Material formulation, structuring and modification are key to increasing the unit volume complexity and density of next generation electronic packaging products. Laser processing…
Abstract
Purpose
Material formulation, structuring and modification are key to increasing the unit volume complexity and density of next generation electronic packaging products. Laser processing is finding an increasing number of applications in the fabrication of these advanced microelectronic devices. The purpose of this paper is to discuss the development of new laser‐processing capabilities involving the synthesis and optimization of materials for tunable device applications.
Design/methodology/approach
The paper focuses on the application of laser processing to two specific material areas, namely thin films and nanocomposite films. The examples include BaTiO3‐based thin films and BaTiO3 polymer‐based nanocomposites.
Findings
A variety of new regular and random 3D surface patterns are highlighted. A frequency‐tripled Nd:YAG laser operating at a wavelength of 355 nm is used for the micromachining study. The micromachining is used to make various patterned surface morphologies. Depending on the laser fluence used, one can form a “wavy,” random 3D structure, or an array of regular 3D patterns. Furthermore, the laser was used to generate free‐standing nano and micro particles from thin film surfaces. In the case of BaTiO3 polymer‐based nanocomposites, micromachining is used to generate arrays of variable‐thickness capacitors. The resultant thickness of the capacitors depends on the number of laser pulses applied. Micromachining is also used to make long, deep, multiple channels in capacitance layers. When these channels are filled with metal, the spacings between two metallized channels acted as individual vertical capacitors, and parallel connection eventually produce vertical multilayer capacitors. For a given volume of capacitor material, theoretical capacitance calculations are made for variable channel widths and spacings. For comparison, calculations are also made for a “normal” capacitor, that is, a horizontal capacitor having a single pair of electrodes.
Research limitations/implications
This technique can be used to prepare capacitors of various thicknesses from the same capacitance layer, and ultimately can produce variable capacitance density, or a library of capacitors. The process is also capable of making vertical 3D multilayer embedded capacitors from a single capacitance layer. The capacitance benefit of the vertical multilayer capacitors is more pronounced for thicker capacitance layers. The application of a laser processing approach can greatly enhance the utility and optimization of new materials and the devices formed from them.
Originality/value
Laser micromaching technology is developed to fabricate several new structures. It is possible to synthesize nano and micro particles from thin film surfaces. Laser micromachining can produce a variety of random, as well as regular, 3D patterns. As the demand grows for complex multifunctional embedded components for advanced organic packaging, laser micromachining will continue to provide unique opportunities.
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V. Kripesh, S.K. Bhatnagar, H. Osterwinter and W. Gust
Temperature humidity acceleration factors for surface conductance areobtained to relate the reliability of film conductors formed by different processes. Analytical expressionsfor…
Abstract
Temperature humidity acceleration factors for surface conductance are obtained to relate the reliability of film conductors formed by different processes. Analytical expressions for acceleration factor are evolved for both screen‐printed and laser micromachined conductor samples. The rapid solidification of metal conductors due to laser micromachining and its effect on surface conductance are also studied. An analytical expression for the most common accelerated test condition (85°C, 85% relative humidity) is also derived for both screen‐printed and laser micromachined samples.
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Many new micromachined angular rate sensors (gyroscopes) are now commercially available. Their rapid development has been mainly due to the automotive industry. A wide range of…
Abstract
Many new micromachined angular rate sensors (gyroscopes) are now commercially available. Their rapid development has been mainly due to the automotive industry. A wide range of different devices exists and their performance is significantly improving every year while costs are falling. Much effort is now under way for large volume production. This article provides a general overview of gyroscopic sensors and also describes a novel micromachined rotating device.
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Reviews intelligent structures through surface‐ and bulk‐micromachining. Examines the merits of these techniques and their past, present and future applications to real‐life…
Abstract
Reviews intelligent structures through surface‐ and bulk‐micromachining. Examines the merits of these techniques and their past, present and future applications to real‐life problems.
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T. Lalinsky´, Sˇ. Haščík, Ž. Mozolová, E. Burian, M. Krnáč, M. Tomáška, J. Škriniarová, M. Drzˇík, I. Kosticˇ and L. Matay
A new micromachining technology of mechanically fixed and thermally insulated cantilevers, bridges and islands was developed to be used for design of GaAs heterostructure based…
Abstract
A new micromachining technology of mechanically fixed and thermally insulated cantilevers, bridges and islands was developed to be used for design of GaAs heterostructure based microelectromechanical systems (MEMS) devices. Based on the micromachining technology, two different MEMS devices were designed and analyzed. The first one was micromechanical thermal converter (MTC) and the second one was a micromechanical coplanar waveguide (MCPW). The basic electro‐thermal as well as microwave properties of the MEMS devices designed are investigated. The results obtained are also supported by simulation. The advantages of the fixed micromechanical structures in the field of design of new MEMS devices are discussed.
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V. Kripesh, S.K. Bhatnagar, H. Osterwinter and W. Gust
A laser ablation technique has been used to fabricate conductor patterns on a 96%alumina substrate to evolve passive fine‐line components and structures. This paper reports the…
Abstract
A laser ablation technique has been used to fabricate conductor patterns on a 96% alumina substrate to evolve passive fine‐line components and structures. This paper reports the method of fabricating better fine‐line passive components for hybrid microelectronics application. The effect of a laser beam on the conductor and 96% alumina (Al2O3) substrate was studied in detail. Three predominant structures — namely debris, ablation border and irradiated bottom layer — were seen on the patterns. A detailed study of the dendritic growth caused by electrochemical migration on conductor lines fabricated by conventional screen printing and by laser ablation techniques is also reported.
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Reviews some of the more important technologies used for fabricating microcomponents and systems – bulk silicon micromachining, surface micromachining and LIGA, a process for…
Abstract
Reviews some of the more important technologies used for fabricating microcomponents and systems – bulk silicon micromachining, surface micromachining and LIGA, a process for forming deep microstructures by lithography, electroforming and moulding. Discusses the relative merits of using synchroton, electron beam and excimer laser irradiation. Gives a comb actuator and an electrostatic motor as examples of micromachined components.
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Micromachining is becoming an increasingly important technique in sensor fabrication and could have huge potential commercially, as Stephen McClelland explains.
S.P. Beeby, N.J. Grabham and N.M. White
This paper describes a self‐test procedure for a micromachined silicon accelerometer realized using a commercially available microprocessor. The accelerometer is fabricated using…
Abstract
This paper describes a self‐test procedure for a micromachined silicon accelerometer realized using a commercially available microprocessor. The accelerometer is fabricated using a combination of thick‐film printing and silicon micromachining. It consists of a silicon structure with thick‐film piezoelectric elements that act as sensors, detecting the deflections of the inertial mass, and also as actuators capable of performing a self‐test routine. The self‐test procedure must be performed at resonance and the microprocessor is used to identify the individual resonant frequency of each device and confirm the operation of the PZT elements. This work has successfully demonstrated the feasibility of a microprocessor implemented procedure and has highlighted some interesting behavioral characteristics of the accelerometer. The microprocessor could also be used in the future to fully test and calibrate the device thereby ensuring correct and accurate operation.
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A. Arshak, K. Arshak, G. Lyons, D. Waldron, D. Morris, O. Korostynska and E. Jafer
Telemetry capsules have existed since the 1950s and were used to measure temperature, pH or pressure inside the gastrointestinal (GI) tract. It was hoped that these capsules would…
Abstract
Purpose
Telemetry capsules have existed since the 1950s and were used to measure temperature, pH or pressure inside the gastrointestinal (GI) tract. It was hoped that these capsules would replace invasive techniques in the diagnosis of function disorders in the GI tract. However, problems such as signal loss and uncertainty of the pills position limited their use in a clinical setting. In this paper, a review of the capabilities of microelectromechanical systems (MEMS) for the fabrication of a wireless pressure sensor microsystem is presented.
Design/methodology/approach
The circuit requirements and methods of data transfer are examined. The available fabrication methods for MEMS sensors are also discussed and examples of wireless sensors are given. Finally, the drawbacks of using this technology are examined.
Findings
MEMS for use in wireless monitoring of pressure in the GI tract have been investigated. It has been shown that capacitive pressure sensors are particularly suitable for this purpose. Sensors fabricated for wireless continuous monitoring of pressure have been reviewed. Great progress, especially using surface micromachining, has been made in recent years. However, despite these advances, some challenges remain.
Originality/value
Provides a review of the capabilities of MEMS.
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