The United States of America As Represented by the United States

Sandia Corporation

Other

Robert R Rye

Antonio J Ricco

William Larry Smith

Terry Arthur Michalske

Frederick G Yost

J Adin Mann, Jr

Robert J Martinez

M J Hampden-Smith

T T Kodas

An open-channel capillary is provided, having preferably a v-shaped groove in a flat wettable surface. The groove has timing marks and a source marker in which the specimen to be tested is deposited. The time of passage between the timing marks is recorded, and the ratio of surface tension .gamma. to viscosity .mu. is determined from the equation given below: ##EQU1## where h.sub.0 is the groove depth, .alpha. is the groove angle, .theta. is the liquid/solid contact angle, and t is the flow time. It has been shown by the inventors that the kinetics are only at most a weak function of K(.alpha.,.theta.); moreover, a wide range of theoretical assumptions show comparable numerical values for K(.alpha.,.theta.). .gamma..div..mu. and h.sub.0 are the only parameters. With the depth of the groove being an experimentally controllable parameter, the ratio of .gamma..div..mu. is the only free parameter. The value of .gamma..div..mu. can be determined from plots of z.sup.2 v. t by taking the slope of the curve for measured value of h.sub.0.

Measurement of surface tension and viscosity by open capillary techniques

A method is described for patterned depositions of a material onto a substrate. A surface of a polymeric substrate is first etched so as to form an etched layer having enhanced adhesions characteristics and then selected portions of the etched layer are removed so as to define a pattern having enhanced and diminished adhesion characteristics for the deposition of a conductor onto the remaining etched layer. In one embodiment, a surface of a PTFE substrate is chemically etched so as to improve the adhesion of copper thereto. Thereafter, selected portions of the etched surface are irradiated with a laser beam so as to remove the etched selected portions of the etched surface and form patterns of enhanced and diminished adhesion of copper thereto.

Methods for patterned deposition on a substrate

A method for forming hermetic coatings on optical fibers by hot filament assisted chemical vapor deposition advantageously produces a desirable coating while maintaining the pristine strength of the pristine fiber. The hermetic coatings may be formed from a variety of substances, such as, for example, boron nitride and carbon.

Method for forming hermetic coatings for optical fibers

Using a hot filament (.apprxeq.1400.degree. C.) to activate borazine (B.sub.3 N.sub.3 H.sub.6) molecules for subsequent reaction with a direct line-of-sight substrate, transparent boron ntiride films as thick as 25,000 angstroms are grown for a substrate temperature as low as 100.degree. C. The minimum temperature is determined by radiative heating from the adjacent hot filament. The low temperature BN films show no indication of crystallinity with X-ray diffraction (XRD). X-ray photoelectron spectra (XPS) show the films to have a B:N ratio of 0.97:1 with no other XPS detectable impurities above the 0.5% level. Both Raman and infrared (IR) spectroscopy are characteristic of h-BN with small amounts of hydrogen detected as N-H and B-H bands in the IR spectrum. An important feature of this method is the separation and localization of the thermal activation step at the hot filament from the surface reaction and film growth steps at the substrate surface. This allows both higher temperature thermal activation and lower temperature film growth.

Hot filament CVD of boron nitride films

A photolithographic method for treating an article formed of polymeric material comprises subjecting portions of a surface of the polymeric article to ionizing radiation; and then subjecting the surface to chemical etching. The ionizing radiation treatment according to the present invention minimizes the effect of the subseuent chemical etching treatment. Thus, selective protection from the effects of chemical etching can be easily provided. The present invention has particular applicability to articles formed of fluorocarbons, such as PTFE. The ionizing radiation employed in the method may comprise Mg(k.alpha.) X-rays or lower-energy electrons.

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Albuquerque, NM, United States of America

Robert R Rye