Electrical glass conductive adhesives

Kazuya H, Takeshi M, Manabu S, Takeshi K, Manabu T. Asahi glass. Electric double layer capacitor having an electrode bonded to a current collector via a carbon type conductive adhesive layer. US patent /6072692. 

Several approaches using electrically conductive adhesives instead of solder have been explored and are proving successful. Anisotropic adhesives (See Chapter 1), for example, have been used to connect flex circuits and cables from the separate driver circuits to the panel, avoiding the use of solder connections. More importantly, integrated-circuit chips can be bonded directly to the ITO conductor traces on the panel, a technology called chip-on-glass (COG). IC chips can be flip-chip bonded, then underfilled with a stress-free underfill adhesive if necessary. For protection, the chips may then be encapsulated with epoxy (glob-topped). 

In order to study the effect of electrical forces on adhesion, it is convenient to consider two types of contact processes those occurring between a semiconductor (dust particle) and a metal (substrate) and those occurring between a semiconductor (dust particle) and another semiconductor (glass or painted metal substrate) [82]. In the contact zone there is a leveling out of the Fermi levels and a bending of the conduction and valence bands (Fig. IV. 1. b), with the simultaneous appearance of a contact potential difference at the interface between the two contacting bodies. 

After application of the matrix, the TLC plate is loaded directly into the MALDI device. The most obvious and simple approach is to fix the TLC plate with conductive adhesive tape onto a standard MALDI target (although a dedicated TLC adapter is now also available from Bruker Daltonics). To avoid charging effects in the MALDI source by residual charged particles on the surface and to enable successful ion desorption, an electrically conductive surface is needed. Therefore, the use of TLC glass plates is absolutely discouraged, whereas alumina TLC plates are perfect for this application. Such plates are commercially available with different stationary phases. 

Fillers are relatively nonadhesive substances added to the adhesive formulation to improve its working properties, strength, permanence, or other qualities. The improvements resulting from the use of fillers are listed in Table 1.8. Fillers are also used to reduce material cost. By selective use of fillers, the properties of an adhesive can be changed significantly. Thermal expansion, electrical and thermal conduction, shrinkage, viscosity, and thermal resistance are only a few properties that can be modified by the use of fillers. Common fillers are wood flour, silica, alumina, titanium oxide, metal powders, china clay and earth, slate dust, and glass fibers. Some fillers may act as extenders. 

In addition to their excellent weatherability and the benefits that implies, silicones are sometimes the sealant of choice because of their controllable cure rate (it can be fast or slow), or adhesion qualities (silicones can bond glass together to form an aquarium with no other support or reinforcement necessary or bond glass in a building with no other supports necessary), or its nontoxicity (many silicones have FDA, USDA clearance), or its non-conductive electrical qualities. 

By virtue of their high silver content, silver-glass adhesives have high electrical conductivities, typically 1.3 x 10 ohm-cm. Other typical properties are flexural modulus of 350 kpsi, die shear adhesion of 900 psi, and CTE of 20 ppm/°C. ... 

In the materials science area, dendrimers have been used for adhesive tie coats to glass, metal, carbon, or polymer surfaces, additives for polymer resins and composites, printing inks, surfactants, cross-linking agents, electrically conductive nano devices,flow regulators, processing aids, and chemical... 

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