Disk fabrication

Mechanical Properties. One interesting example is electroless Ni(P). Electroless Ni(P) is harder and has better corrosion resistance than does electrodeposited Ni(P). Nonmagnetic electroless Ni(P), or NiCu(P), is used as underlayer in high-density metallic memory disk fabrication to improve the mechanical nish of the surface. 

Contact lithography can offer a high resolution and is in principle less expensive than the optical lithographic methods. It uses a method similar as in optical disk fabrication. It has been demonstrated that imprint technology... 

A review of vaginal bioadhesive formulations indicates that bioadhesive tablets have been used for localized treatment of diseases in the vaginal tissue.F ° l For example. Bleomycin, an antitumor agent, was incorporated into a flat-faced disk fabricated from a combination of hydroxypropyl cellulose and poly-(acrylic acid) (Carbopol 934). ° The tablet was designed to release Bleomycin at a slow rate to minimize irritation to healthy mucosa. Another vaginal tablet is formulated from the combination of poly(acrylic acid) with hydroxypropyl methylcellulose and ethylcellu-lose. Other polymer combinations evaluated for potential bioadhesive vaginal delivery include poly(acrylic acid) and sodium carboxymethyl cellulose with Avicel PH102 (methylcellulose) as the diluent. Insulin has been formulated in a cross-linked poly(acrylic acid) gel... 

It has been reported [40] that the infiltration rate of F-CVI can reach 1 mm per hour, while the infiltration rate of I-CVI techniques is much slower, around 1 mm per day. Figure 5.26 shows the density distribution of a large disk fabricated using a F-CVI technique for 40 h. The dimension of the SiC/SiC composite disk is 264 mm in diameter and 12.7 mm thick. The results indicate that the relative densities (real density/theoretical density) of the interior region are high, around 90%. However, the relative density of both exterior parts is lower (about 80%) than that of the central part. 

Dry Cleaning. In colorfastness to dry cleaning, ISO 105-D01 a specimen of the textile is placed in a cotton fabric bag together with stainless steel disks and agitated in perchloroethylene (30 min, 20°C) and the effect of the shade and the color of the solvent assessed using the grey scale. 

Refer to Fig. 15-39. The tower is formed into compartments by horizontal doughnut-shaped or annular baffles, and within each compartment agitation is provided by a rotating, centrally located, horizontal disk. Somewhat similar devices have been known for some time. The features here are that the rotating disk is smooth and flat and of a diameter less than that of the opening in the stationaiy baffles, which facihtates fabrication and apparently improves extraction rates. The typical proportions of the internals of the RDC are as follows ... 

The Code requires that the disks be burst on test by one of three methods using four sample disks, but not less than 5% from each lot. Figure 7-32 illustrates test results for burst pressure versus temperature of a disk design, all fabricated from the same material, and of the same diameter. 

The rotating-disk CVD reactor (Fig. 1) can be used to deposit thin films in the fabrication of microelectronic components. The susceptor on which the deposition occurs is heated (typically around lOOOK) and rotated (speeds around 1000 rpm). A boundary layer is formed as the gas is drawn in a swirling motion across the spinning, heated susceptor. In spite of its three-dimensional nature, a peculiar property of this flow is that, in the absence of buoyant forces and geometrical constraints, the species and temperature gradients normal to the disk are the same everywhere on the disk. Consequently, the deposition is highly uniform - an especially desirable property when the deposition is on a microelectronic substrate. 

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