Fabrication, defined

The membranes of the microhotplates were released by anisotropic, wet-chemical etching in KOH. In order to fabricate defined Si-islands that serve as heat spreaders of the microhotplate, an electrochemical etch stop (ECE) technique using a 4-electrode configuration was applied [109]. ECE on fully processed CMOS wafers requires, that aU reticles on the wafers are electrically interconnected to provide distributed biasing to the n-well regions and the substrate from two contact pads [1 lOj. The formation of the contact pads and the reticle interconnection requires a special photolithographic process flow in the CMOS process, but no additional non-standard processes. 

Less LF with higher temperature (for example heat LF for automotive fabrics), defined by LF testing... 

Figure 2. Shows development of planar fabric defined by the biotite flakes photomicrographs are imder X Nicols.

Barry et al. elegantly demonstrated the extrusion of concentrated inks of acrylamide through fine deposition nozzles in filamentary forms to fabricate defined patterns [112]. The ink also contained a photoinitiator, namely diethoxyacetophe-none, which was used to solidify the constructs via photopolymerization. Further,... 

Comparison of the procedures for the thickness measurement in three types of nonwoven fabrics defined in the test standards (BS EN ISO 9703-2 1995) can be found in other book. In comparison with the measurement of thickness of woven fabrics, the measurement of nonwoven fabric thickness requires a different sampling procedure, specific pressures at which to test normal and bulky nonwovens, a specific area for the size of the presser foot, and a shorter time to note the gauge reading. 

Initially, it was not clear whether the stress dip was real or an experimental artifact, as early experiments on heaps were inconclusive. Eventually, Vanel et al. [54] and Geng et al. [55] showed that the stress dip was intrinsically tied to how the system was prepared. If the preparation history induced a non-isotropic fabric (defined later), it was possible to create a stress dip. The idea is that a fabric, that is, the network of contacts, that leads to a strong force network which is inclined along the slope of the heap can effectively create "buttresses" that shield the more... 

There have been numerous efforts to inspect specimens by ultrasonic reflectivity (or pulse-echo) measurements. In these inspections ultrasonic reflectivity is often used to observe changes in the acoustical impedance, and from this observation to localize defects in the specimen. However, the term defect is related to any discontinuity within the specimen and, consequently, more information is needed than only ultrasonic reflectivity to define the discontinuity as a defect. This information may be provided by three-dimensional ultrasonic reflection tomography and a priori knowledge about the specimen (e.g., the specimen fabrication process, its design, the intended purpose and the material). A more comprehensive review of defect characterization and related nondestructive evaluation (NDE) methods is provided elsewhere [1]. 

These tests permited us to define minimum requirements to obtain for our fabrication applications, and to introduce in our code minimum requirements and method to verify them. 

There is hardly a metal that cannot, or has not, been joined by some welding process. From a practical standpoint, however, the range of alloy systems that may be welded is more restricted. The term weldability specifies the capacity of a metal, or combination of metals, to be welded under fabrication conditions into a suitable stmcture that provides satisfactory service. It is not a precisely defined concept, but encompasses a range of conditions, eg, base- and filler-metal combinations, type of process, procedures, surface conditions, and joint geometries of the base metals (12). A number of tests have been developed to measure weldabiHty. These tests generally are intended to determine the susceptibiHty of welds to cracking. 

Film and sheet are defined as flat unsupported sections of a plastic resia whose thickness is very thin ia relation to its width and length. Films are generally regarded as being 0.25 mm or less, whereas sheet may range from this thickness to several centimeters thick. Film and sheet may be used alone ia their unsupported state or may be combined through lamination, coextmsion, or coating. They may also be used in combination with other materials such as paper, foil, or fabrics. 

The dissipation factor (the ratio of the energy dissipated to the energy stored per cycle) is affected by the frequency, temperature, crystallinity, and void content of the fabricated stmcture. At certain temperatures and frequencies, the crystalline and amorphous regions become resonant. Because of the molecular vibrations, appHed electrical energy is lost by internal friction within the polymer which results in an increase in the dissipation factor. The dissipation factor peaks for these resins correspond to well-defined transitions, but the magnitude of the variation is minor as compared to other polymers. The low temperature transition at —97° C causes the only meaningful dissipation factor peak. The dissipation factor has a maximum of 10 —10 Hz at RT at high crystallinity (93%) the peak at 10 —10 Hz is absent. 

Maximum Service Temperature. Because the cellular materials, like their parent polymers (204), gradually decrease in modulus as the temperature rises rather than undergoing a sharp change in properties, it is difficult to precisely define the maximum service temperature of cellular polymers. The upper temperature limit of use for most cellular polymers is governed predominantly by the plastic phase. Fabrication of the polymer into a... 

Dielectric Film Deposition. Dielectric films are found in all VLSI circuits to provide insulation between conducting layers, as diffusion and ion implantation (qv) masks, for diffusion from doped oxides, to cap doped films to prevent outdiffusion, and for passivating devices as a measure of protection against external contamination, moisture, and scratches. Properties that define the nature and function of dielectric films are the dielectric constant, the process temperature, and specific fabrication characteristics such as step coverage, gap-filling capabihties, density stress, contamination, thickness uniformity, deposition rate, and moisture resistance (2). Several processes are used to deposit dielectric films including atmospheric pressure CVD (APCVD), low pressure CVD (LPCVD), or plasma-enhanced CVD (PECVD) (see Plasma technology). 

Deposition of Thin Films. Laser photochemical deposition has been extensively studied, especially with respect to fabrication of microelectronic stmctures (see Integrated circuits). This procedure could be used in integrated circuit fabrication for the direct generation of patterns. Laser-aided chemical vapor deposition, which can be used to deposit layers of semiconductors, metals, and insulators, could define the circuit features. The deposits can have dimensions in the micrometer regime and they can be produced in specific patterns. Laser chemical vapor deposition can use either of two approaches. 

Defined as the average value measured in the four principal directions paradel to the fabric surface two across the pile. one with, and one against the... 

As with any other fabrication process, masks are needed to define the features to be etched. It is common that the etch used for the semiconductor also etches the masking material. For this reason many different masks are used in etching, including photoresist, dielectric films, and metals. Masking can be a complex issue, especially when very deep etches (>5 fim) are performed with high aspect ratios (148). 

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