Лако-красочные материалы — производство

Several processing techniques have been developed to achieve anisotropic conductivity. One method aligns the conductive metal particles in a magnetic field [41-43]. Alternatively, anisotropy can be achieved in materials with random dispersions of metal particles. Using an adhesive composite where the concentration of metal particles is below but close to pc results in a material […]

Increasing the concentration of metal particles in an insulating adhesive matrix changes the electrical properties of the composite in a discontinuous way. Assuming a random dispersion of the metal filler, as the concentration increases no significant change occurs until a critical concentration, pc, is reached. This point, where the electrical resistivity decreases dramatically, called the […]

A relatively new application for conductive adhesives, and a very important one in terms of technological advance and future manufacturing techniques, is the assembly of liquid crystal displays (LCDs). Interconnecting flexible circuit connectors, tape automated bonding packages, and bare IC chips to glass panels have been the principal technology drivers for the development of anisotropically […]

The most significant application for conductive adhesives in the manufacture of micro­electronics is the attachment of silicon chips to lead frames. Of the 40 billion integrated circuits (ICs) manufactured each year, approximately 90% are encapsulated in plastic — molded packages, and most of these are assembled with conductive adhesives [4]. A sche­matic illustration of a […]

In this section we discuss three applications of electrically conductive adhesives: die attach adhesives, anisotropically conductive adhesives for liquid crystal display (LCD) assembly, and conductive adhesives for surface-mounted assembly of packaged components on printed wiring boards (PWBs). These applications were selected based on overall Material Resistivity (^ cm) Silver 1.6 x 10~6 Copper 1.7 x […]

Alan M. Lyons and D. W. Dahringer AT&T Bell Laboratories, Murray Hill, New Jersey, U. S.A. I. INTRODUCTION Electrically conductive adhesives perform two primary functions. Like other types of adhesives, these materials provide a physical bond between two surfaces. In addition, an electrical interconnection between the two bonded surfaces is formed. This dual func­tionality is […]

Several guide formulations for various applications follow. It must be remembered that they should merely be used as a starting point to develop a satisfactory product. Not all materials will be available in all countries, and the nature and quality may vary from country to country. To simplify formulations, trade names have been used, and […]

Because of the unique properties of pressure-sensitive adhesives, special tests not applicable to other types have been developed. While standard physical tests such as nonvolatile content, viscosity, and specific gravity are performed to ensure consistency of application, these tests do not predict adhesive performance. For pressure-sensitive adhesives, three critical performance characteristics are usually measured: tack, […]

Most of the popular coating methods are suitable for pressure-sensitive adhesives. Solvent — based adhesives are usually applied by roller coaters or occasionally by spray applicators. Water-based adhesives also use roller coaters predominantly, with nozzle feed machines the exception. Hot melts may be extruded, applied from slot orifice coaters, or calendared. Figure 3 Reverse roll […]

The largest market outside tapes and labels is for adhesives for floor tiles. Peel-and-stick floor tiles are available from hardware stores for use by homeowners. These tiles usually have a hot-melt pressure-sensitive adhesive applied to the back so that laying to clean, prepared floors only needs the removal of a backing paper and pressing the […]