Resistive foils

Safety and handling Actiq is supplied in individually sealed child-resistant foil pouches. 

Scuff and rub resistance—foil will abrade fairly easily (foil to foil, foil to product, etc.), producing dark particles. 

Chem. Descrip. Thermoplastic methacrylate resin Uses Binder for PVC finishing lacquers, coatings for plastic substrates with exc. alcohol resist., foil lacquers, printing inks Features Very low m.w. compat. with most PVC copolymers, NC, chlorinated rubber... 

The electrodeposited copper foils described above account for most of the conductive foils used in rigid printed circuits. However, modified versions of these foils are sometimes used in niche applications. These modified versions include double-treated copper foil and resistive foils. 

J.6.5.2 Resistive Foils. Other treatments can also be applied to the base foil for nse in mannfactnring inner-layer circnits with buried resistors. This technology can enable the creation of resistors on internal layers of a mnltilayer circnit, with removal of many of the resistors commonly assembled on the outside of the multilayer circuit. This can improve board reliability and free np space on the outside of the board for active components. These foils typically nse a resistive metal alloy coated onto the base foil. The laminate made with this foil can then be seqnentially imaged and etched to produce the desired circuit pattern along with resistive components. 

Polyester. Poly(ethylene terephthalate) [25038-59-9] (PET) polyester film has intermediate gas- and water- vapor barrier properties, very high tensile and impact strengths, and high temperature resistance (see Polyesters, thermoplastic). AppHcations include use as an outer web in laminations to protect aluminum foil. It is coated with PVDC to function as the flat or sealing web for vacuum/gas flush packaged processed meat, cheese, or fresh pasta. 

The solder and ahoy market, including low melting or fusible ahoys, is a principal user of indium (see SoLDERS AND BRAZING ALLOYS). The addition of indium results in unique properties of solders such as improved corrosion and fatigue resistance, increased hardness, and compatibhity with gold substrates. To fachitate use in various appHcations, indium and its ahoys can be easily fabricated into wine, ribbon, foil, spheres, preforms, solder paste, and powder. 

Silver reduces the oxygen evolution potential at the anode, which reduces the rate of corrosion and decreases lead contamination of the cathode. Lead—antimony—silver alloy anodes are used for the production of thin copper foil for use in electronics. Lead—silver (2 wt %), lead—silver (1 wt %)—tin (1 wt %), and lead—antimony (6 wt %)—silver (1—2 wt %) alloys ate used as anodes in cathodic protection of steel pipes and stmctures in fresh, brackish, or seawater. The lead dioxide layer is not only conductive, but also resists decomposition in chloride environments. Silver-free alloys rapidly become passivated and scale badly in seawater. Silver is also added to the positive grids of lead—acid batteries in small amounts (0.005—0.05 wt %) to reduce the rate of corrosion. 

Ziac foil coated with a conductive, pressure-sensitive adhesive is used for repair of other ziac coatings or for imparting corrosion resistance at field sites. The 0.08-mm ziac tape or sheet has a 0.025-mm coaductive adhesive. The laminate is cut to size and pressed tightly to activate the adhesive. Conductive tape can be wrapped around pipe, especially around welds or connections. The corrosion resistance of this material is iatermediate between galvanized or thermally sprayed coatings and zinc-filled paints (21,50). 

Fiber dmms can be produced to meet a wide variety of requirements. They can be constmcted with adhesives for water resistance, their interiors can be coated, their walls and ends can incorporate metal foil or asphalt-impregnated pHes, and their exteriors can be decorated by painting, varnishing, and silk screening for both ornamental and functional purposes. 

II) foil, tape heat-resistant ahoys, steels stmctural turbiae parts... 

Adhesives. Poly(vinyl alcohol) is used as a component in a wide variety of general-purpose adhesives to bond ceUulosic materials, such as paper and paperboard, wood textiles, some metal foils, and porous ceramic surfaces, to each other. It is also an effective binder for pigments and other finely divided powders. Both fully and partially hydrolyzed grades are used. Sensitivity to water increases with decreasing degree of hydrolysis and the addition of plasticizer. Poly(vinyl alcohol) in many appHcations is employed as an additive to other polymer systems to improve the cohesive strength, film flexibiUty, moisture resistance, and other properties. It is incorporated into a wide variety of adhesives through its use as a protective coUoid in emulsion p olymerization. 

Zirconium is completely resistant to sulfuric acid up to Foiling temperatures, at concentrations up to 70 wt %, except that the heat-affected zones at welds have lower resistance in >55 wt % concentration acid (Fig. 1). Fluoride ions must be excluded from the sulfuric acid. Cupric, ferric, or nitrate ions significantly increase the corrosion rate of zirconium in 65—75 wt % sulfuric acid. 

SemiadditiveMethod. The semiadditive method was developed to reduce copper waste. Thin 5.0 lm (4.5 mg/cm ) copper foil laminates are used, or the whole surface may be plated with a thin layer of electroless copper. Hole forming, catalysis, and electroless copper plating are done as for subtractive circuitry. A strippable reverse—resist coating is then appHed. Copper is electroplated to 35 p.m or more, followed by tin or tin—lead plating to serve as an etch resist. The resist is removed, and the whole board is etched. The original thin copper layer is quickly removed to leave the desired circuit. This method wastes less than 10% of the copper. 

Copper To 1500 Properties depend on other construction materials and form of copper used. Packing made of copper foil over asbestos core resists steam and alkalies to lOOO F. Packing of braided copper tinsel resists water, steam, and gases to 1500 F. 

The most common form of energy deposition used for planar shock wave research has been electrical resistance heating of a metal foil which vaporizes, driving a flyer plate to a high velocity before it impacts a specimen. In a hybrid system incorporation both resistance vaporization and an electromagnetic push, velocities to 18 km/s are reported for kapton flyer plates which are... 

Dick and Styrus [63] report real-time resistivity measurements on shoek-loaded silver foils. The inferred vaeaney eoneentration is 1.5 x 10 per atomie site for samples shoek loaded to 10 GPa. The eombined effect of point-defect generation and reeombination to form vaeaney clusters, for example, can be influential on pulse-duration effeets such reload, release, and recovery. This topie has not yet reeeived the degree of experimental study that it deserves. 

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