Micro-etching

A distinction must be made between the macro etch pits with geometrical contours (8,9,6), which are observed even at low magnifications and the micro etch pits which have no distinct geometrical shape. The former probably reveal only a fraction of the dislocations, whereas the latter give a better measure of the total number of dislocations (13,12,30). 

Removes the surface layer by a micro-etching process. 

It must be reiterated that an atmospheric plasma glow discharge provides a treatment with high uniformity and homogeneity, along with the ability to micro-etch and functionalize the surface of films (in this case with carbon-based functionality). In the case of OPP film, the level of heat seal strength is 20% higher than the level obtained with corona pretreatment. 

The same description holds true for plasma with a few exceptions. The rate at which electron bombardment occurs is > 100 times that for corona. This increased cross-linking activity forces a greater ion bombardment onto the substrate surface, which in turn results in increased micro-etchings on the substrate s surface, and stronger bonding attributes across the substrate. 

Figure 7.3 shows how plasma bombardment is able to create a micro-roughness on a polyethylene film. The depth in micro-etching is approximately 4-6 A, in other words, it does not modify the mechanical bulk properties of the film but strongly... 

Figure 7.3 Comparing the surface of a PET film before and after plasma treatment with the 30 000 magnification of an SEM microscope. The typical depth in micro-etching is approx.

The peel adhesion data indicated that at a power density of 10 W/mVmin, printed APT-treated polyester surpassed peel adhesion results registered by printed corona-treated polyester by a margin of 78%. Moreover, the 23% decrease in ink peel adhesion between unprinted and printed corona-treated base material compared to the less than a 4% decline in ink peel adhesion between unprinted and printed APT-treated base material suggests that the formation of strong covalent atomic bonds on a cleaned and uniform, homogeneously micro-etched surface may account for improved anchorage of inks. 

Micro-etch Micro-etch Conditioner Micro-etch Micro-etch Micro-etch Micro-etch... 

For flow at a given rate, the only way to significantly increase the heat transfer coefficient is to reduce the channel size, whose optimum can be calculated assuming a practical limit on the available pressure. Recourse to multiple channels, instead of continuous coolant flow over the entire back substrate surface, enables one to multiply the substrate area by a factor (jp, representing the total surface area of the channel walls which are in contact with fluid. Single-row micro-channels etched dir-... 

Turner et al. (2004) studied the independent variables relative surface roughness, Knudsen number and Mach number and their influence on the friction factor. The micro-channels were etched into silicon wafers, capped with glass, with hydraulic diameters between 5 and 96 pm. Their surface roughness was 0.002 < ks< 0.06 pm for the smooth channels, and 0.33 < / < 1 -6 pm for the glass-capped ones. The surface roughness of the glass micro-channels was measured to be in the range 0.0014 [Pg.39]

We have designed, manufactured and tested a prototype that may be applied in thermal control of electronic devices. It was fabricated from a silicon substrate and a Pyrex cover, serving as both an insulator and a window through which flow patterns and boiling phenomena could be observed. A number of parallel triangular micro-channels were etched in the substrate. The heat transferred from the device was simulated by different types of electrical heaters that provided uniform and non-uniform heat fluxes, defined here respectively as constant and non-constant values... 

Fig. 2.72a-c Construction of buried micro-channels by combined anisotropic and isotropic etching. Reprinted from Kandlikar and Grande (2002) with permission... 

The active micro-channel cooling contains a cooling system centered on a microheat collector that is fabricated much in the same way as the chip. Heat collector usually has a dense amount of micro-channels etched into the surface that works to transfer heat to a fluid, which is circulated through the entire package. 

In Proceedings of 21st SemiTherm Symposium, San Jose, 15-17 March 2005, pp 354—360 Mohr J, Ehrfeld W, Munchmeyer D (1988) Requirements on resist layers in deep-etch synchrotron radiation lithography. J Vac Sci Technol B6 2264-2267 Morini GL (2004) Single phase convective heat transfer in micro-channels overview of experimental results. Int J Thermal Sci 43 631-651... 

Fig. 3.15 Examples of ultrahydrophobic surfaces. Lithographically etched silicon surface patterned with 30 pm tall cubic micro-posts. Reprinted from Ou et i. (2004) with permission...

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