Patterned layer

Decorative laminates have a core or base of Kraft paper impregnated with a phenolic resin. A printed pattern layer impregnated with a melamine-formaldehyde or urea-thiourea-formaldehyde resin is then laid on the core and on top of this a melamine resin-impregnated protective translucent outer sheet. The assembly is then cured at 125-150°C in multi-daylight presses in the usual way. 

The hardest of the transition-metal borides are the diborides. Their characteristic crystal structure (Figure 10.6) consists of plane layers of close-packed metal atoms separated by plane openly-patterned layers of boron atoms ( chicken-wire pattern). If the metal atoms in the hexagonal close-packed layer have a spacing, d, then the boron atoms have a spacing of d/V3. 

Application of silanes for promoting resist patterning layer adhesion in semiconductor manufacturing... 

The type of adhesion dealt with in the examples in the second paragraph above and Fig. 1 is mechanical or structural while for the lithographic resist adhesion requirements described in this paper a more practical definition of adhesion, one first proposed by Mittal [16], is being referenced and used. Resist patterning layer-substrate adhesion is required only to process or pattern a particular device layer. After the circuit layer is patterned, the resist layer is removed and does not become an integral part of the circuit, as opposed to a PI interlevel metal dielectric layer which does. As such, it is not required to possess high mechanical adhesion strength. In fact, the resist layer must be quantitatively removed after the circuit required layer has been patterned. If the resist layer adheres too well and becomes difficult to remove, it actually interferes with successful circuit fabrication. 

Figure 10.13 shows examples of high-resolution patterns formed on small scale cylindrical objects - optical fiber and microcapillary tubes [1]. These simple devices (integrated photomasks for optical fiber Bragg gratings and intravascular stents), require only one patterned layer. 

Lithography is a method of printing an image by applying patterned layers of color to paper with a series of etched metal or stone plates. This is the process used to print many newspapers and multi-colored lithographs. It is also the general name for the techniques used to fabricate integrated circuits (ICs). 

Bulk micromachining relies on several etching techniques and creates projections of planar photolithographic masks in 3 dimensions. Surface micromachining relies on sacrificial layer and wafer bonding techniques. It creates true 3D structures as a stack of 2D patterned layers. Hence, it is more correct to refer to both micromachining techniques as two and a half dimensional (2% D). 

Microwriting is another simple technique to fabricate patterned layers. In this method a solution of alkanethiol is dispensed through the capillary on the surface, and this capillary is used to write the patterns on the surface. Because of the autophobicity of alkanethiols, no excess of the deposition solution remains on the treated surface. Features down to 10 pm could be prepared508. 

An often applied method for the synthesis of hydrogels, especially for applications in medicine and pharmaceutics, is based on radiochemistry. The hydrogel can be formed by irradiation of monomers, polymers dissolved in water, or polymers in dry state. Electrons of different energies or y-rays are used as high-energy radiation. The possibilities of the radiation-chemical synthesis of smart hydrogels are discussed on different examples. The technique is applied to bulk polymers, to micro- and nanogel particles, and to patterned layers on different materials. The basics and fundamentals of irradiation techniques as well as the equipment are described. 

Many applications of hydrogels need a patterned layer on a substrate. Different techniques were used for patterning in different regions of dimension (Table 2). 

For patient monitoring as well as for extracellular microphysiometry low volume fluid handling systems with integrated microbiosensor arrays have to be developed (Trajanoski et al. 1996). A very versatile and reliable technology is the use of polymer laminate film. The laminate is based on a PCB material and provides mixed fluidic-electric platform for the assembly of a biosensor array and microfluidic channels. Subsequent lamination of dry film resist layers over previously patterned layers allows the creation of closed channels without the use of any sacrificial layer (Fig. 3). 

In shadow masking, a stencil intercepts unwanted material and allows the desired material to reach the substrate. The shadow mask can be a freestanding or tensioned sheet like an etched metal foil, or a patterned layer on the substrate which can be easily removed. The technique is relatively general - evaporation processes, some solution processes, and some sputtering processes can be patterned in this way. The features which can be formed... 

A technique was developed called multilayer soft fithography that combines soft fithography with the capability to bond multiple patterned layers of elastomer. 

The manufacture of integrated circuits involve a series of lithographic, deposition, and etching steps to fabricate patterned layers. This process is often called planar processing or planar technology. 

Both porphyrins and fuUerenes can be deposited onto surfaces imder ultra-high vacuum (UHV) conditions as studied by Diederich et aL [126, 127]. In a first step, a monolayer of porphyrins or extended porphyrin analogues can be formed which can be analyzed using AFM or STM imaging techniques. UHV deposition of a second layer of Ceo on top of a full monolayer of porphyrins leads to the formation of supramolecular assem-bhes, and the precise structure of the arrangement of the Ceo on the patterned layer can be controlled by the porphyrin structure. The observed modes of self-assembly result from a delicate balance between the fullerene-porphyrin interaction and the conformational motion within the porphyrin monolayer. 

In a similar way, gold pattern layers have been put on PI substrates by micro contact printing. " In micro contact printing, a polymeric stamp that is wetted with a potassium hydroxide solution is pressed onto the PI substrate. The alkaline treated regions of the substrate become hydrophilic and are prone to hold a palladium(II) solution. In the same way as described above, the adhered palladium ions are reduced by NaBILj and further electroplated. 

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