This PDF file contains the front matter associated with SPIE Proceedings Volume 6459, including the Title Page, Copyright information, Table of Contents, Introduction (if any), and the Conference Committee listing.

The main focus of this article lies on the development of a novel joining technology for LTCC ceramic and polymer sub-assemblies utilising laser radiation. Technical processes and the latest results are presented as well as potential future applications. The developed joining process can be divided into two steps utilizing the same laser system: a surface modification of the joining partners and a thermal process that is melting a small portion of the polymer matrix that is being pressed into the roughness of the ceramic surface.

Most welding processes for plastics do not meet the demands of micro technology and thus cannot be applied in this innovative industrial sector. One of the few techniques which are applicable in this sector is the laser transmission welding, which has distinctive advantages like low mechanical and thermal load of the joining parts. This makes the laser particularly suitable for the welding of micro plastics parts. Thereby, contour welding is a process variant of laser transmission welding enabling the welding of complex and even three-dimensional weld contours. But so far it has not yet been applied for welding plastics parts of micro scale in the industrial practice. Recent research at the Institute of Plastics Processing (IKV) at the RWTH Aachen University shows the feasibility of this process to weld small and complex micro parts. Good mechanical properties can be achieved. However, it is necessary to apply measures to reduce the formation of flash. Moreover, it can be shown that there is a strong influence of some material parameters on the laser welding process so that some plastics are more suitable than others for the contour welding in micro technology.

Longterm stable and high precise interconnections between small optical components and the optomechanical platform are mandatory for the assembly of complex and miniaturized optoelectronical systems. The approach discussed in this paper is to integrate optics and electronics on a common platform that is a ceramic Printed Circuit Board with embedded mounting structures for easy passive alignment of the optical components. Active alignment with higher accuracy can also be used, in both cases laserbeam soldering is the preferred and precise joining technology. Thin solder layers as well as solder bumps are used to create joints with an accuracy <±0.5 &mgr;m, suitable for singlemode coupling applications.

Despite the electronic manufacturing is well-established mass production process for a long time, the problem of reworking, i.a. reject and replace of defect components, still exists. The rework operations (soldering, replacement and desoldering) are performed in most cases manually. However, this practice is characterized by an inconsistent quality of the reworked solder joints and a high degree of physiological stress for the employees. In this paper, we propose a novel full-automated laser based soldering and rework process. Our developed soldering system is a pick-and-place unit with an integrated galvanometer scanner, a fiber coupled diode laser for quasi-simultaneous soldering and a pyrometer-based process control. The developed system provides soldering and reworking processes taking into account a kind of defect, a type of electronic component and quality requirements from the IPC- 610 norm. The paper spends a great deal of efforts to analyze quality of laser reworked solder joints. The quality depends mainly on the type and thickness of intermetallic phases between solder, pads and leads; the wetting angles between pad, solder and lead; and finally, the joint microstructure with its mechanical properties. The influence of the rework soldering on these three factors is discussed and compared to conventional laser soldering results. In order to optimize the quality of reworked joints, the different strategies of energy input are applied.

In this paper we will discuss various aspects of surface engineering. This is a broad term, and we choose to focus on two aspects thereof, namely surface texturing on the micron scale using laser micromachining, and chemical modification of the surface using molecular vapour deposition (MVD). First, we will discuss the basics of laser texturing, followed by a brief review of contact angle theory. We will then demonstrate how to obtain superhydrophobic surfaces on any kind of material using a combined laser and MVD process. Finally, we will present a few recent industrial cases.

Laser-assisted patterning of polymers is investigated for the direct fabrication of polymeric lab-on-a-chip devices in microsystem technology for capillary electrophoresis chips in bio-analytical applications. In many cases the laser process induces a chemical, physical and topographical change in the laser treated surface. This material modification significantly influences the lab-on-a-chip-functionalities. We will present our current research results in laser-assisted modification of polystyrene (PS) and polymethylmethacrylate (PMMA) with respect to applications in micro-optics, micro-fluidics and cell culture applications. For this purpose the refractive index change, the wettability and the adsorption of proteins and the adhesion of animal cells were investigated as function of laser- and processing parameters. The possible change of surface chemistry was characterized by X-ray photoelectron spectroscopy. The local UV-laser-assisted formation of chemical structures suitable for improved cell adhesion was realized on two- and three-dimensional PS and polycarbonate (PC) surfaces. Above and below the laser ablation threshold two different mechanisms were detected. In one case the produced debris was responsible for improved cell adhesion, while in the other case a photolytical activation of the polymer surface including a subsequent oxidization in oxygen or ambient air leads to a highly localized alteration of protein adsorption from cell culture media and increased cell adhesion. The highly localized control of wettability on polymeric surfaces was investigated for PS and PMMA. In the case of PS the dynamic advancing contact angle could be adjusted between 2° and 150°. This was possible for a suitable exposure dose and an appropriate choice of processing gas (helium or oxygen). A similar but not so significant effect was observed for PMMA below the laser ablation threshold. For PMMA the dynamic advancing contact angle could be adjusted between nearly 50° and 80°. The adjustment of wettability for microfluidic application will be discussed. For the integration of integrated optical waveguides in micro-fluidic devices new approaches for a rapid manufacturing of optical singlemode waveguides made of PMMA were investigated. For this purpose a high repetition excimer laser radiation source was used in combination with a flexible mask technology. The waveguides were characterized for the visible optical range and for 1559 nm. The obtained structures reveal absorption losses of 0.7 dB/cm in the visible range.

As a sequential production method, laser technology is considered not to be a competitor to established plastic processing methods, but instead is used whenever small numbers or just mere prototypes are required. Laser ablation by UV-excimer lasers is a flexible and accurate tool for the manufacturing of polymeric micro-fluidic parts. Even soft and flexible materials like PDMS that are difficult to machine with conventional techniques can be structured by laser ablation with great precision and quality. Sealing of polymer parts by laser beam welding leads to a complete production cycle for small series and prototypes. A further application of UV-excimer lasers is the production of so called "lost moulds" for the production of filigree microstructures. Micro-pillars are fabricated by drilling holes in wax masters using excimer laser radiation and subsequent casting with PDMS. Frictionless demolding is achieved by melting the wax away. The fabricated PDMS micro-pillar arrays can be used for shear stress and flow rate sensors due to bending of the flexible posts. In combination with laser ablation techniques micro-fluidic devices with new properties can be fabricated.

Optical biochips may incorporate both optical and microfluidic components as well as integrated light emitting semiconductor devices. They make use of a wide range of materials including polymers, glasses and thin metal films which are particularly suitable if low cost devices are envisaged. Precision laser micromachining is an ideal flexible manufacturing technique for such materials with the ability to fabricate structures to sub-micron resolutions and a proven track record in manufacturing scale up. Described here is the manufacture of a range of optical biochip devices and components using laser micromachining techniques. The devices employ both microfluidics and electrokinetic processes for biological cell manipulation and characterization. Excimer laser micromachining has been used to create complex microelectrode arrays and microfluidic channels. Excimer lasers have also been employed to create on-chip optical components such as microlenses and waveguides to allow integrated vertical and edge emitting LEDs and lasers to deliver light to analysis sites within the biochips. Ultra short pulse lasers have been used to structure wafer level semiconductor light emitting devices. Both surface patterning and bulk machining of these active wafers while maintaining functionality has been demonstrated. Described here is the use of combinations of ultra short pulse and excimer lasers for the fabrication of structures to provide ring illumination of in-wafer reaction chambers. The laser micromachining processes employed in this work require minimal post-processing and so make them ideally suited to all stages of optical biochip production from development through to small and large volume production.

Using excimer laser with 248 nm wavelength, we have been developed the 45-degree micro-mirrors in the polymer optical waveguide constructed by newly developed epoxy resin. The three-dimensional laser processing technology for controlling the mask aperture size on the laser beam is effective for fabricating the 45-degree mirror. The size of the mirror was about 80 micrometer width. Although the periodical micro patterns have appeared on the surface of the mirrors, we have successfully removed the patterns by the technique of smoothing. Smoothing process has been carried out by the additional laser irradiation with weak and/or strong energy. The obtained surface roughness of the mirrors was less than 120 nm (Ry). The evaluation of the optical loss using laser with 670 nm wavelength resulted in the less than 0.5 dB, indicating sufficient mirror performance.

This paper describes experimental and numerical results of the plasma-assisted microfabrication of subwavelength structures by means of point-by point femtosecond laser inscription. It is shown that the spatio-temporal evolution of light and plasma patterns critically depend on input power. Subwavelength inscription corresponds to the supercritical propagation regimes when pulse power is several times self-focusing threshold. Experimental and numerical profiles show quantitative agreement.

Optical elements with subwavelength structures (SWSs) may function as anti-reflection layers, wave plates, or polarizers. In this study, the authors focus on a pair of two-beam interference lithography systems for fabricating SWS optical elements. These systems have different optical configurations for forming the interference fields required for exposure. The first lithography system described herein creates an interference field by splitting a laser beam with a half-mirror and then superimposing the two resulting beams on a substrate after they propagate through free space. A resist pattern with a period of 140 nm is formed across a 4-inch substrate using a 266-nm CW laser. The other lithography system employs a high-density holographic grating. The two diffracted light waves (0th order and 1st order) produced by the holographic grating generate an interference field in close proximity to the holographic grating, thus enabling a more compact exposure system and a stable lithography process. The desired nano-pattern is obtained by exposing the resist with the 266-nm CW laser using a 140-nm-pitched holographic grating. This research demonstrates the potential of two-beam interference lithography as a viable process for manufacturing SWS optical elements used with the visible spectrum.

A solid-state UV laser was used to make arrays of reproducible percussion-drilled micron-sized holes in polyimide. An optical switch was employed as a pulse picker to select specific patterns of pulses from the high repetition rate laser beam. The ability to control and vary the number of pulses per burst and the time between bursts enhanced the drilling rate while minimizing thermal damage around the holes. The optimum pulse patterns were determined experimentally. A photodiode acted as a breakthrough sensor to end the drilling and optimize the exit hole size and quality. Results were compared with computer simulations of the drilling process based on modeling of the laser/material interaction.

It has been shown that micromachining of polyimide using a mode-locked high repetition rate, 80 MHz, 355nm laser is more efficient than the q-switched laser at same wavelength and same power level in terms of material removal rate. In this study we have explored and characterized the benefits of using high repetition rate, high average power, 355 nm mode-locked and q-switched lasers for micromachining of various microelectronics packaging materials that have different thermal properties. The removal rate and quality of machining have been analyzed against the difference in thermal properties of the material. The implications of the results observed are also discussed from practical manufacturing perspective.

High power excimer lasers are well established as work horses for various kinds of micro material processing. The applications are ranging from drilling holes, trench formation, thin film ablation to the crystallization of amorphous-Si into polycrystalline-Si. All applications use the high photon energy and large pulse power of the excimer technology. The increasing demand for micro scale products has let to the demand for UV lasers which support high throughput production. We report the performance parameters of a newly developed XeCl excimer laser with doubled repetition rate compared to available lasers. The developed laser system delivers up to 900 mJ stabilized pulse energy at 600 Hz repetition rate. The low jitter UV light source operates with excellent energy stability. The outstanding energy stability was reached by using a proprietary solid-state pulser discharge design.

Over the recent years the novel fiber laser technology and its potentials have been exciting laser manufacturers as well as researchers and industrial users. Fiber lasers with their excellent beam quality promised noticeable advantages and improvements in high precision and micro material processing. Besides the excellent beam quality there are more advantages of the fiber laser technology such as compact installation size, high laser efficiency, moderate system price and easy to be integrated. The paper presents the results of extensive comparative tests of short pulse fiber laser systems and a common q-switch rod solid state laser with nearly identical system parameters. The intention was to determine the specific advantages in practical application work. Where are the advantage and how large are the improvements? Therefore typical applications of laser micro machining have been chosen - drilling, cutting and lateral material removal as well as marking. By choosing different materials like aluminum, silicon and ruby a broad field has been examined. Distinct improvements have been proven in several applications especially regarding precision and surface quality of the created structures. Under almost identical conditions the fiber laser achieved more narrow cutting kerfs and smaller hole diameters compared to the rod laser system.

Laser trimming of microelectronics devices has enabled the fabrication of high precision and high performance components and networks. Market demands for decreasing package size and higher performance components have pushed the current laser trimming technology to its limits. To meet the challenges, laser trimming system manufacturers have been working on the new generation based on significant advances in laser technology, software tools, and related system technologies. These new systems can achieve higher accuracy needed for processing devices with ever shrinking dimensions and tighter tolerances while offering maintenance-free operation and flexibility in today's demanding production environments. We will present in this paper the latest advancement of laser based trimming systems. Future directions will also be discussed.

Photovoltaics has in the last five years enjoyed unprecedented growth and acceptance as part of the worldwide energy mix. Innovations in both wafered silicon and various thin-film PV technologies anticipated in the next 5-10 years promise to lower the cost of PV power to parity with that supplied by the grid. When that occurs, the growth of the industry will be pulled even more strongly by market demand. A challenge in meeting this growth will be the availability of automated production equipment that can streamline the solar cell manufacturing process. Laser processing offers the potential to provide several facets of that high-volume manufacturing solution. This paper provides an overview of PV technologies, discusses current and emerging laser processes for PV manufacturing, and highlights some of the challenges for laser technology and systems that must be met to fulfill this promise.

Optical damage produced by femtosecond pulsed lasers on dielectric surfaces is extremely precise, allowing the damage mechanisms to be inferred from reproducible damage characteristics. Here nanoscale femtosecond laser ablation is applied to probe the ultrafast dynamics of laser energy deposition including the generation and transport of surface electron-hole or electron-ion plasmas. For shallow surface nano-craters fabricated on quartz and glass surfaces by single 0.53 &mgr;m or 1.05 &mgr;m laser shots, their corresponding well-defined laser intensity thresholds demonstrate pronounced effects of laser wavelength, crystalline state of the dielectric and laser waist radius, indicating equal importance of laser energy deposition and transport phenomena during ablation. Simultaneously, unusually deep surface nanoholes emerge drilled by self-focusing laser beam or forward-scattered highly penetrating short-wavelength radiation from the warm, dense surface plasma.

The advent of commercial grade picosecond and femtosecond lasers has opened the way for laser micromachining of metals. There has however been no or little work reported on the ceramics. Use of diamond saws is still the preferred way of cutting the ceramics such as an Al₂O₃-TiC composite (referred to as N58 hereafter) that is widely used in the manufacture of read/write heads for magnetic recording hard disk drives. These read/write heads are commonly referred to as "sliders". We report here attempts to cut rows of sliders using various lasers. The cut length was 0.85 mm and the thickness was 0.23 mm. We found that all the nanosecond pulse range lasers, left slag at the laser input edge of the cut and on the cut wall. In many cases the slag deposit doesn't allow one to cut through the entire thickness as the slag interferes with successive laser pulses. Our best results were obtained with picosecond and femtosecond lasers. We were able to cut through entire thickness of the strip with these lasers. The slag was much less than that from the nanosecond lasers, but not low enough for our application. There were slag deposits or loose-appearing material on the cut walls also. The roughness was at best in the micron range. In all the cases studied the cut quality as measured by cut surface roughness and slag formation as well as the cutting speed was worst than that obtained from the diamond saws currently used in the industry.

The field of laser micromachining is highly diverse. There are many different types of lasers available in the market. Due to their differences in irradiating wavelength, output power and pulse characteristic they can be selected for different applications depending on material and feature size [1]. The main issues by using these lasers are heat damages, contamination and low ablation rates. This report examines on the application of the Laser MicroJet(R) (LMJ), a unique combination of a laser beam with a hair-thin water jet as a universal tool for micro-machining of MEMS substrates, as well as ferrous and non-ferrous materials. The materials include gallium arsenide (GaAs) & silicon wafers, steel, tantalum and alumina ceramic. A Nd:YAG laser operating at 1064 nm (infra red) and frequency doubled 532 nm (green) were employed for the micro-machining of these materials.

Laser-induced formation of functional materials from glasses has a great potential for creation of monolithic and high-performance glass-based devices, such as optical circuit and micro-TAS. We have recently developed a laser-induced formation technique of photocatalytic titanium oxide on a UV-absorbing TiO₂-SiO₂- based glass surface by excimer laser irradiation under a specific condition, which we term laser-induced superficial phase separation. The laser-induced structure has the shape of micro-cones, growing into micro-sized network after accumulating laser pulses, which we call TiO₂ micronetwork. The TiO₂ micronetwork exhibited the rutile crystalline phase and photocatalytic ability. Moreover, the crystalline phase can be controlled from the rutile to the anatase by post-treatments. Utilizing this technique, we were able to make a site-selective growth of TiO₂ micronetworks: a microwell array and a microchannel modified with the TiO₂ network only on the bottom. This flexible formation of photocatalytic TiO₂ onto a glass surface without any heat-treatments and/or adhesives opens a new way to develop a monolithic glass device like micro-fluidics with light-catalyzed reactions.

Laser supported processes can be used to modify the electrical and thermal properties of ceramic substrates locally. These processes are characterised by a strong thermal interaction between the laser beam and the ceramic surface which leads to localised melting. During the dynamic melting process metal particles are introduced into the melt pool in order to modify the physical properties. Different alumina samples were treated with metal powders of tungsten, copper, and oxides of these metals. The interface between the metal and the ceramic can be designed by using selected combinations of metal- and metal-oxide-powders and also by a thermal post-processing. The application of nano-particles during the laser-dispersing process resulted in completely different characteristics of the micro-structure and the electrical properties compared to the conventional metal powders with an average grain size of 5 - 15 microns. The micron sized metal particles are embedded within the ceramic matrix as particle agglomerates or as distinct metal phase the nano-particle phase covers the grain boundaries of the ceramics leading to network of nano-scaled electrically conducting "wires". The resulting resistance of the laser tracks can be adjusted from semi-conducting to metallic behavior with a resistivity down to 2x10^-6W/m. The modified ceramic can be used for heating elements working at operation temperatures of up to 1000^oC, high current resistances which can be loaded with currents of up to 100 A.

Recent prominent progresses in synthesizing and manipulating single-walled carbon nanotubes (SWNTs) stimulated extensive interests in developing SWNT-based devices for nanoelectronics and nanoelectromechanical systems (NEMS). Thermal chemical vapor deposition (CVD) is one of the most widely accepted technique for growing SWNTs by heating the whole chamber and substrate to required reaction temperatures. In this study, we demonstrated a process for position-controllable synthesis of SWNT-FET by bridging the SWNT across pre-defined electrodes using the laser chemical vapor deposition (LCVD) technique. The SWNT-FET was back-gate modulated, showing p-type semiconducting characteristics. The process is very fast and can be conducted using both far-infrared CO₂ laser (10.6 &mgr;m) and near-infrared Nd:YAG laser (1064 nm). We have also demonstrated localized synthesis of SWNTs by a focused laser beam. Due to the unique advantages of LCVD process, such as fast and local heating, as well as its potential to select chiralities during the growing process, it may provide new features and versatilities in the device fabrication.

Currently, enhancement of Raman scattering for nanoscale characterization is mostly based on tip- or surface-enhanced methods. However, both approaches have some dilemmas which impede their wide applications. In this study, we investigated a novel approach to enhance Raman scattering using closely-packed micro and submicro silica spherical particles. The enhancement phenomena haven been demonstrated by the silicon phonon mode of crystalline silicon (c-Si) substrates as well as the vibration modes of single-walled carbon nanotubes (SWCNTs) covered with microparticles. The studies show that the enhancement effects strongly depend on the particle size. Specifically, when the particle size is close to the beam waist of the incident laser, the strongest enhancement occurs. Numerical simulations are performed to calculate electric field distribution inside and outside the dielectric particles using the Optiwave^TM software which is based on the finite difference time domain (FDTD) algorithm under the perfectly matched layer (PML) boundary conditions. The simulated results reveal the existence of photonic nanojects in the vicinity outside the particles along with the light traveling direction. The nanojets outside of the particles with a length of 100 nm and a waist of 120 nm are believed to be the base for Raman scattering enhancement. This technique has potential applications in many areas such as surface science, biology, and microelectronics.

Lasers are capable of delivering energy to a metal to induce stresses from the thermal gradient through the material. Under the right conditions these stresses can cause the metal to bend. Experiments were conducted to produce bending in the metal, Neyoro^® G, and samples with a titanium coating on one side. In the experiments, both upward and downward bending was observed. The titanium coated samples showed potential to be more controllable than the uncoated samples.

The low temperature fabrication of active (field effect transistor) electrical components on flexible polymer substrates is presented in this paper. A drop-on-demand (DOD) ink-jetting system was used to print gold nano-particles suspended in organic solvent, PVP (poly-4-vinylphenol) in PGMEA (propylene glycol monomethyl ether acetate) solvent, semiconductor polymer in organic solvent to fabricate passive and active electrical components on flexible polymer substrates. Short pulsed laser ablation enabled finer electrical components to overcome the resolution limitation of inkjet deposition. Continuous Argon ion laser was irradiated locally to evaporate the carrier solvent as well as to sinter gold nano-particles. In addition, a new method for the selective ablation of multilayered gold nanoparticle film was demonstrated.

Laser radiation is used both for the deposition of the laser active thin films and for the micro structuring to define wave guiding structures for the fabrication of waveguide lasers. Thin films of Er:ZBLAN (a glass consisting of ZrF₄, BaF₂, LaF₃, AlF₃, NaF, ErF₃) for green upconversion lasers (545 nm), Nd:YAG (Y₃Al₅O₁₂) and Nd:GGG (Gd₃Ga₅O₁₂) for infrared lasers (1064 nm) are produced. Manufacturing of the laser active waveguides by micro-structuring is done using fs laser ablation of the deposited films. The structural and optical properties of the films and the damping losses of the structured waveguides are determined in view of the design and the fabrication of compact and efficient diode pumped waveguide lasers. The resulting waveguides are polished, provided with resonator mirrors, pumped using diode lasers and characterized. Laser operation of a ridge waveguide structure grown by pulsed laser deposition and structured by fs laser ablation is demonstrated. A 1 &mgr;m thick, 100 &mgr;m wide and 3 mm long structured waveguide consisting of amorphous neodymium doped Gd₃Ga₅O₁₂ has shown laser activity at 1.068 &mgr;m when pumped by a diode laser at 808 nm.

We report the successful fabrication of layers of functionalized nanoparticles using a novel infrared, laser-based deposition technique. A frozen suspension of nanoparticles was ablated with a laser tuned to a vibrational mode of the solvent, resulting in the disruption of the matrix and ejection of the nanoparticles. The solvent was pumped away and the nanoparticles collected by a receiving substrate in a conformal process. Photoluminescence measurements of nanoparticles containing two common dyes showed no significant change to the emission properties of either dye, suggesting that no damage occurred during the laser ablation process. The process is generally applicable to particles of various sizes, shapes, and chemistries provided that an appropriate solvent is chosen. Deposition through shadow masks turned out to be straightforward using this technique, suggesting its potential utility in preparing designer sensor structures using functionalized nanoparticles.

Quality of diamond films is strongly dependent on substrate temperatures, which are usually controlled in a range of 600 - 1100 °C in most experiments. Although many applications have been achieved with these techniques, diamond film growth is still not possible for substrates that cannot endure such high temperatures for long time. In this study, a continue-wave (CW) CO₂ laser was used to irradiate the growth area on tungsten carbide (WC) substrates during C₂H₂/O₂ combustion-flame deposition in order to maintain required temperature in the growth area while keep the rest of the substrates at a low temperature. The laser power was adjusted between 200 - 600 W to study the effects of laser irradiation on diamond deposition. Surface morphologies of the deposited films were examined by a scanning electron microscope (SEM). Film structures were characterized by Raman spectroscopy. It was concluded that the CO₂ laser irradiation during combustion-flame deposition could raise the temperature at the growth area efficiently. Both laser power and power density have effects on the diamond deposition. Laser irradiation with proper parameters could improve the crystal quality of the diamond films. Based on the experimental results, the CO₂ laser-assisted combustion-flame deposition is a promising method for local substrate heating during diamond film growth.

A KrF excimer laser was used in combination with a combustion flame to deposit diamond films on cemented tungsten carbide (WC-Co) substrates. The laser has a wavelength of 248 nm, a pulse width of 23 ns, a pulse energy range of 84~450 mJ, and a repetition rate up to 50 Hz. Using the combustion flame method, diamond films were deposited on the laser-processed WC-Co substrates for 10 min. The morphologies of the deposited diamond films were examined using a scanning electron microscopy (SEM). The composition and bonding structures in the deposited films were studied by energy dispersive X-ray analysis (EDX) and Raman spectroscopy, respectively. The film adhesion was characterized by scratching a razor across the films. It was found that C composition on WC-Co substrate surfaces was eliminated by the laser irradiation. As a consequence, diamond nucleation density decreased and diamond grains grew larger in the laser-processed areas. Based on the experimental results, a film growth mechanism at different deposition temperature ranges corresponding to pre-deposition laser-surface-treatment effects was proposed.

This study presents a novel non-contact method, designated as laser induced local material transfer (LILMT), for patterning carbon nanotube (CNT) emitters on the cathode of a CNT backlight unit (CNT-BLU) under the environment of the atmosphere and at room temperature. The LILMT method makes possible the manufacturing of large-scale substrates with a higher resolution than that which can be attained using familiar screen-printing methods. The preliminary results obtained for the field emissions of square-type and line-type CNT emitters confirm the effectiveness of the proposed patterning method.

Selective Laser Melting (SLM) is a generative manufacturing procedure mainly known for the application with metal powders. From these, metallic structures are produced in a layer-by-layer way. This layer-related procedure is comparable to the stereolithographic manufacturing of polymer devices. On a base plate, a thin layer of metal powder is spread. The powder is locally completely melted by the application of a focused laser beam. The base plate is then lowered by a value defined by the thickness of the metal layer, metal powder is spread again, and the local melting process is re-initiated. The complete procedure is continued as described, until the device is manufactured in the defined way. Commercially available metal powder can be used as base material. In principle, the SLM process should be suitable for the generation of metallic microstructures. The main precondition for the generation of microstructures by SLM is that the spatial resolution of the laser focus is small and precise enough to generate microstructure walls of around 100μm thickness in a reproducible way by melting metal powder. The walls should be gas- and leak-tight. In this publication, experimental results of the generation of metallic microstructure devices by SLM will be given. The process will be described in details. Process parameters for the generation of stainless steel devices having wall thicknesses in the range of about 100μm will be given. Examples for microstructure devices made by SLM will be shown. The devices can be manufactured in a reproducible way. Moreover, very first preliminary results on the use of ceramic powder as base material will be presented.