Mechanical etching

I have attempted to adapt a chemically or mechanically etched glass tube to air inlet-outlet geometries that have low probabilities of particle loss. With desirable air-liquid flow-rate ratios as stated, the integrity of a continuous film covering the surface, if formed in the first place, was short-lived. Invariably, within a few hours dry areas would be apparent, and in the worst case a single narrow stream of water would flow down one wall. 

Electrical, metal contact Conductivity, liquid Mechanical Etching rate... 

Registration numbers may be mechanically etched into the plastic s surfaces and colouring materials applied afterwards to enhance visibihly. The latter is an irreversible process and can be disfiguring. 

Slikkerveer, P.J., Bouten, P.C.P., and De Haas, F.C.M. (2000) High quality mechanical etching of brittle materials by powder blasting. Sens. Actuators A Phys.,... 

Fig. 11.1. Schematic diagram of the preparation of BDD MDA electrodes (a) photoresist pattern formed on a silicon substrate> (b) isotropic etching of the substrate (c) Deposition of BDD (d) spin-coating and mechanical etching of the polyimide film.

Another view of the Si(lOO) etching mechanism has been proposed recently [28], Calculations have revealed that the most important step may actually be the escape of the bystander silicon atom, rather than SiBr2 desorption. In this way, the SiBr2 becomes trapped in a state that otherwise has a very short lifetime, pennitting many more desorption attempts. Prelimmary results suggest that indeed this vacancy-assisted desorption is the key step to etching Si(lOO) with Br2. 

Etch Mechanisms. Most wet etches for the compound semiconductors employ oxidation of the semiconductor followed by dissolution of the oxide. For this reason, many wet etches contain the oxidant hydrogen peroxide, although nitric acid can also be used. One advantage of wet etching over dry is the absence of subsurface damage that is common with dry etching. Metal contacts placed on wet-etched surfaces exhibit more ideal characteristics than dry-etched surfaces. 

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