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Precious Metal Powders and Preparations

86 bytes added, 14:36, 15 April 2014
Conductive Paints and Adhesives
=== Conductive Paints and Adhesives===
 
Conductive paints are precious metal preparations in liquid or paste form. They contain the metal filler material, fine silver particles as conductive pigments mostly in flake form, a paint compound on artificial resin basis, and an organic solvent <xr id="tab:Silver Paints, Conductive Pastes, and Conductive Adhesives"/> (Table 8.3). The solvent evaporates during drying in air or by aging at slightly elevated temperatures. This allows the silver particles to connect metallically and form conductive paths <xr id="fig:Flexible keyboard contact pattern printed with AUROMAL 170"/> (Fig. 8.3).
<figure id="fig:Flexible keyboard contact pattern printed with AUROMAL 170">[[File:Flexible keyboard contact pattern printed with AUROMAL 170.jpg|right|thumb|Flexible keyboard contact pattern printed with AUROMAL 170]]</figure>
Conductive adhesives are used mostly for mechanical bonding with low thermal impact. As the adhesive components high-polymer organic substances such as epoxy resins and mixed polymers are mostly used. They are made electrically filler materials such as flake shaped silver powders (70 – 80 wt%). Silver based conductive adhesives are available as single or two component adhesive systems. Both types are hardening without the application of pressure.
Conductive paints and adhesives have broad applications in electrical and electronic engineering. They are used for example for the contacting of film resistors, mounting of terminal wires, conducting electrostatic electricity, or contacting components at low temperatures.
The mechanical strength of the bond connections depends mostly on the selected hardening temperature ''<xr id="fig:Shear force of an adhesive joint"/> (Fig. 8.4)''.
Fig. 8.3<figure id="fig:Flexible keyboard contact pattern printed with AUROMAL 170">[[File:Flexible keyboard contact pattern printed with AUROMAL 170.jpg|right|thumb|Flexible keyboard contact patternprinted with AUROMAL 170]]</figure>
Fig. 8.4<figure id="fig:Shear force of an adhesive joint">[[File:Shear force of an adhesive joint.jpg|right|thumb|Shear force of an adhesive joint(silver adhesive AUROMAL K 20) as a function ofthe hardening temperature]]</figure>
=== Precious Metal Flakes===

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