Insulating substrates

Integrated circuit substrates Insulation, heat resistance Alumina, magnesia... 

Ceramics Alumina. Catalyst, Molecular Sieves, Substrates. Insulator Body, Tilemix, Press Feed, Proppants, Frits, Colors... 

Berrylium, Precious Metals, Aluminum, Silicon, Nickel Glass Rawmix, Furnace Dust, Glass Powder Alumina, Catalyst, Molecular Sieves, Substrates, Insulator Body, Tilemix, Press Feed, Proppants, Frits, Colors Bauxite, Alumina, Kiln Dust, Blends Raw Meal, Kiln Dust... 

D. End-Uses Coatings for flexible substrates insulating tape. 

To investigate the effect of passivation layer on the performances of a-Si H TFTs under mechanical stress, we stressed both TFTs by outward cylindrical bending at the radius of curvature R = 5 mm as shown in Fig. 6. Less than R = 4 mm, most of TFTs employing acrylic polymer or SiNx as passivation layer were failed. When the radius of curvature was 5 mm, the strain on the surface of aciyl and SiNx was 0.0082 (0.82 %) and 0.0077 (0.72 %), respectively. Eq. 1 considering single aciyl (3 jtan) or SiNx (substrate-insulation, te-insulation and backchannel passivation 0.9 jtan) layer calculated the strain. 

These various concepts can be categorised according to semiconductor material (small molecules or polymers), the share of inorganic components (substrate, insulator, electrodes) and the design (top-gate or bottom-gate electrode). 

In the case of the slightest defects in the coating corrosion elements appear on the metal substrate. As a result, areas of the substrate insulated by the coating from the corrosive medium function as the cathode and the naked areas of the substrate near the coating defects serve as the anode and acquire a more negative potential than the cathodic areas. The electrode potential difference between the anodic and cathodic areas of the substrate is a function of the ohmic potential drop on the cathode and can reach 200-300 mV. This is commensurate with the contact potential difference assumed dangerous for metal structures (0.25 V) [1]. 

In general, film adhesives are best suited as insulation to isolate circuitry or to attach large devices or substrates. Insulative films have volume resistivities from 10 to 10 " ohm-cm, thermal conductivities from 0.8 to 1 W/mK, and lap shear strengths ranging from 1200 to 3000 psi. They are available in thicknesses from 2 to 8 mils. ° ... 

Thermoelectric (TE) modules are solid-state heat pumps that operate on the Peltier effect [1]. A TE module consists of an array of p- and n- type semiconductor elements heavily doped with electrical carriers. The array of elements is soldered so that it is electrically connected in series and thermally connected in parallel [1 ]. This array is then often affixed to two ceramic substrates (insulators), one on each side of the elements as seen in Figure 1. 

Use the ANSYS PDS capability to select a material system and geometric dimensions to minimize stres.ses in the ceramic substrate (insulation plates) and TE brittle materials. A material system is composed of the downselected materials for the TE, ceramic substrate, and electric contact materials. 

Fig. 27.2 Young s modulus and linear thermal expansion coefficients (relative to 300 K) between 300 K open circles) and 1,000 K closed circles) of electrode metals, ionic conductors, and substrate/insulator materials for solid-state ionic micro gas sensors (polycrystalline materials). Young s modulus of NASICON and were not available (Reprinted with permission from Dubbe 2003, Copyright 2003 Elsevier)...

The operation of the STM depends on the conduction of electrons between tip and sample. This means, of course, that insulating samples are, in general, not accessible to STM investigations. Nevertheless, a large body of work [32] dealing with STM characterization of thin organic films on conducting substrates is now in... 

Several designs for STM electrochemical cells have appeared in the literature [M]- hr addition to an airtight liquid cell and the tip insulation mentioned above, other desirable features include the incorporation of a reference electrode (e.g. Ag/AgCl in saturated KCl) and a bipotentiostat arrangement, which allows the independent control of the two working electrodes (i.e. tip and substrate) [ ] (figure BL19.11). 

Figure Bl.19.12. Basic principles of SECM. (a) With ultramicroelectrode (UME) far from substrate, diflfiision leads to a steady-state current, ij, (b) UME near an insulating substrate. Flindered diflhision leads to < ij, 3D. (c) UME near a conductive substrate. Positive feedback leads to go. (Taken from [62],...

Kwak J and Bard A J 1989 Soanning eleotroohemioal miorosoopy—apparatus and two-dimensional soans of oonduotive and insulating substrates Ana/. Chem. 61 1794... 

Non-thennal plasmas in contact with insulating walls (substrate) have an important property. The plasma with the hot electrons is positively charged relative to the wall (self-bias). A sheath with a positive space charge and an electric field is fonned between the wall and the plasma. The hot electrons travel faster to the wall than the heavy... 

CVD gaseous reactants (precursors) delivered to a heated substrate in a flow reactor undergo tliennal reaction to deposit solid films at atmospheric or reduced pressure, and volatile side products are pumped away. CVD is used for conductors, insulators and dielectrics, elemental semiconductors and compound semiconductors and is a workliorse in tire silicon microelectronics industry. 

Several striking examples demonstrating the atomically precise control exercised by the STM have been reported. A "quantum corral" of Fe atoms has been fabricated by placing 48 atoms in a circle on a flat Cu(lll) surface at 4K (Fig. 4) (94). Both STM (under ultrahigh vacuum) and atomic force microscopy (AFM, under ambient conditions) have been employed to fabricate nanoscale magnetic mounds of Fe, Co, Ni, and CoCr on metal and insulator substrates (95). The AFM has also been used to deposit organic material, such as octadecanethiol onto the surface of mica (96). New appHcations of this type of nanofabrication ate being reported at an ever-faster rate (97—99). 

The thermal protection system of the space shutde is composed mainly of subliming or melting ablators that are used below their fusion or vaporization reaction temperatures (42). In addition to the carbon-carbon systems discussed above, a flexible reusable surface insulation composed of Nomex felt substrate, a Du Pont polyamide fiber material, is used on a large portion of the upper surface. High and low temperature reusable surface insulation composed of siHca-based low density tiles are used on the bottom surface of the vehicle, which sees a more severe reentry heating environment than does the upper surface of the vehicle (43). 

Exhaust gas temperature sensor Catalytic substrate Heat insulator... 

Fig. 3. An overview of atomistic mechanisms involved in electroceramic components and the corresponding uses (a) ferroelectric domains capacitors and piezoelectrics, PTC thermistors (b) electronic conduction NTC thermistor (c) insulators and substrates (d) surface conduction humidity sensors (e) ferrimagnetic domains ferrite hard and soft magnets, magnetic tape (f) metal—semiconductor transition critical temperature NTC thermistor (g) ionic conduction gas sensors and batteries and (h) grain boundary phenomena varistors, boundary layer capacitors, PTC thermistors.

Lasdy, the importance of electroceramic substrates and insulators should not be overlooked. Here one strives to raise the breakdown strength by eliminating the interesting conduction mechanisms just described. Spark plugs, high voltage insulators, and electronic substrates and packages are made from ceramics like alumina, mullite [55964-99-3] and porcelain [1332-58-7]. 

Polyesters are also used in continuous filament spunbonded nonwovens (see Nonwoven fabrics). Reemay spunbonded fabric is composed of continuous filament PET with a polyester copolymer binder. These spunbonded fabrics are available in a wide range of thicknesses and basis weights and can be used for electrical insulation, coated fabric substrates, disposable apparel for clean rooms, hospitals, and geotextiles (qv). 

As a tme thermoplastic, FEP copolymer can be melt-processed by extmsion and compression, injection, and blow molding. Films can be heat-bonded and sealed, vacuum-formed, and laminated to various substrates. Chemical inertness and corrosion resistance make FEP highly suitable for chemical services its dielectric and insulating properties favor it for electrical and electronic service and its low frictional properties, mechanical toughness, thermal stabiUty, and nonstick quaUty make it highly suitable for bearings and seals, high temperature components, and nonstick surfaces. 

Catalysis. Ion implantation and sputtering in general are useful methods for preparing catalysts on metal and insulator substrates. This has been demonstrated for reactions at gas—soHd and Hquid—soHd interfaces. Ion implantation should be considered in cases where good adhesion of the active metal to the substrate is needed or production of novel materials with catalytic properties different from either the substrate or the pure active metal is wanted (129—131). Ion beam mixing of deposited films also promises interesting prospects for the preparation of catalysts (132). 

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