Substrate preparation cleaning

Substrate preparation Cleaning and baking Cleaning and baking... 

One of the biggest challenges in this industry is the wide variety of substrates that can be encountered for any given application. Not only can the materials be substantially different in their chemical make up, but they may also be quite different in surface roughness, surface curvature and thermal expansion behavior. To help adhesion to these substrates, preparation of the surface to be bonded may be critical. This preparation may be as simple as a cleaning step, but may also include chemical priming and sanding of the surface. 

The most reliable and easy to control method of oxide films application is provided by either sputtering of an oxide layer (e. g., by a laser beiun), or evaporation of a thin metal zinc film (its resistance is usually 5-10 Ohm) from tantalum vessel onto a thoroughly prepared clean quartz substrate in a vacuum of Torr (containing no oil and... 

All substrate preparations prior to the deposition of the organic materials are carried out in a clean room environment to minimize particulates on the anode surface. OLEDs are typically... 

Amorphous films were prepared by thermal evaporation of the Sb Sei-, source material from an open stainless steel boat onto preoxidized A1 substrates in a vacuum of approximately 10 Torr. The substrate was cleaned in neutral detergent, deionized water, ethyl alcohol, and acetone and then oxidized in air at 1800°C before deposition. Deposition of the Sb Sei-, alloys was performed at a substrate temperature of 300K. It should be noted that while the substrate is aluminum, the layer directly under the film is aluminum oxide. Care was taken to avoid Sb fractionation. It should also be noted that... 

When a metal substrate was cleaned with oxygen-argon plasma followed by a thin layer (100-500 nm) of plasma silane polymer deposit, the coated substrates showed good humidity and corrosion resistance. Samples were prepared and placed either in a humidity chamber (85% RH and 60°C) or immersed in a salt solution (5% NaCI) for 5 days. The plasma-coated samples showed little or no pitting on the surfaces, while severe corrosion appeared on the uncoated sample. 

Consider the polymer-on-metal interface, which might be prepared by coating a thin metal film with polymer in a polymer-based LED. The case of the counter electrode, formed by vapor-deposition, is discussed subsequently. First, assume that the substrates have clean surfaces hydrocarbon and oxide free, or naturally oxidized but still hydrocarbon free (pointed out as necessary). Typically, in connection with polymer-based LEDs, the metallic substrate could be gold, ITO (indium tin oxide) coated glass, the clean natural oxide of aluminum ( 20 A in thickness), the natural oxide which forms upon freshly etched Si( 110) wafers ( 10 A), or possibly even a polyaniline film. Dirt , which may be either a problem or an advantage, will not be taken up here. Discussions will alternate between coated polymer films and condensed model molecular solid films, as necessary to illustrate points. 

For low- to medium-strength bonds, simple mechanical abrasion is a suitable surface preparation if the substrates are cleaned first. This surface preparation has found success in most ABS applications. A silane primer such as Dow Coming A-4094 or General Electric SS-4101 may be used for higher strength.57 For maximum joint strength, a warm chromic acid etch of the ABS substrate is suggested.58... 

In contrast to the pseudomorphic relationship proposed in the LEED study, SXRD data [37,63] from the MgO(100)-Fe system indicate that for a 1 ML equivalent film the Fe lattice parameter is approximately 2.89 A, which is close to that of bulk Fe. For the latter study, however, a rather different preparative procedure was employed. Firstly, the MgO substrate was cleaned in solvents ex situ and only heated to 633 K in UHV. Then the sample was maintained at 633 K, whilst Fe was sputtered onto it, using a planar magnetron sputter gun. 

The preparation procedure is schematically illustrated in Fig. 1. Glass plates of 1 cm x 1 cm x 1 mm, previously cleaned in an ultrasound alkaline bath, rinsed in pure acetone, and dried under nitrogen flow, are used as support substrates. After cleaning, aluminium electrodes (width 0.5 mm, height 60 nm) are deposited on the glass substrate by thermal evaporation in high vacuum... 

SAM Formation. SAMs of 11-MUA were prepared ex situ in 1-3 mM ethanolic solution of 11-mercaptoundecanoic acid, which was purchased at Sigma Aldrich. Two different substrates were used Au(lll)/mica and recrystallized gold foils. Typically, substrates are cleaned in piranha solution. This procedure was not possible for Au( 11 l)/mica, because it led to a separation of the gold layer from the mica substrate. Therefore, both substrates were cleaned in a UHV chamber by Ar+ -sputtering, followed by short annealing at 800 K to get a smooth surface. After removal from the vacuum chamber, it was immediately immersed into the solution. Typically samples remained for 48 h in the solution. After removal out of solution, the samples were rinsed with ethanol and dried with C02 - spray. 

Substrate preparation. Thin films of mixed transition metal oxides were deposited by spin-coating on Si (100) tiles. Before deposition Si tiles were pretreated as follows. Square pieces (0.9 x 0.9 cm ) were first cleaned by HF (2%) dipping for 20 s to remove native oxide from its surface. After several rinsings with water (HPLC grade), the tiles were kept in water. UV/O3 treatment (Jelight s UVO-Cleaner A2, % = 254 nm) was applied to obtain a static contact angle nearing 0. 

An alternative approach to increasing the rate of esterification is to activate further the intermediate (2). N-Bromosuccinimide has been used for this purpose, but unsaturation in the carboxylic acid or alcohol is not tolerated. More generally useful is the addition of an activated halide, usually A//y/ Bromide, to a chloroform solution of (1) and a carboxylic acid, resulting in formation of the acylimidazolium salt (3) (eq 4). Addition of the alcohol and stirring for 1-10 h at room temperature or at reflux affords good yields of ester in a one-pot procedure. These conditions work well for the formation of methyl, ethyl, and i-butyl esters of aliphatic, aromatic, and a,/3-unsaturated acids. Hindered esters such as i-butyl pivalate can be prepared cleanly (90% yield). The only limitation is that substrates must not contain functionality that can be alkylated by the excess of the reactive halide. 

A crucial step in the substrate preparation is cleaning of the substrate prior... 

Preparation of substrates Planing, cleaning Abrading, chemical surface treatment Conditioning of materials before bonding... 

Surface Preparation Commentary for Steel and Concrete Substrates Solvent Cleaning Hand Tool Cleaning... 

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