Adhesion element

Sandies was grinded, covered with carbon and analysed with a Scanning Electron Microscope (JEOL-JXA-840 SEM). An agglomerated sanqrle ts shown in Figure 2. where it can be seen that the grains are held together wiA an adhesive. Elemental analysis with EDX shows differences in composition between grain and adhesive a fact, which has also been reported earlier . 

A cermet thick-film paste has four major ingredients an active element, an adhesion element, an organic binder, and a solvent or thinner. The combination of the organic binder and thinner are often referred to as the vehicle, since it acts as the transport mechanism of the active and adhesion elements to the substrate. When these constituents are mixed together and milled for a period of time, the result is a thick, viscous mixture suitable for screen printing. 

The organic binder, a nonvolatile organic, serves the purpose of holding the active elements and the adhesion elements in suspension until firing of the fihn takes place, and it also provides the paste with the desired fluid characteristics needed for screen printing. The organic binder, such as ethyl cellulose... 

The composihon and characterishcs of the paste are critical factors in screen printing. The cermet (combinahon of ceramic and metal) pastes commonly used in the thick-film technology have four major ingredients (1) an active element that establishes the frmction of the film, (2) an adhesion element that provides the adhesion to the substrate, (3) an organic binder a matrix that holds the active particles in suspension and which provides the proper fluid properhes for screen printing, and (4) a solvent or thinner that establishes the viscosity of the vehicle phase [21,22]. 

The combination of the organic binder and the thinner are often referred to as the vehicle that transports the active element and the adhesion element to the substrate. 

The solids content (active element + adhesion element) as a ratio of the total weight of the paste will dramatically affect the ability of the paste to be screened and also the density of the fired film. If the solids content is high, the fired film will be dense, but will also be difficult to screen. 

An adhesion element, which provides the adhesion to the substrate and a matrix which holds the active particles in suspension... 

The Adhesion Element. There are two primary constituents used to bond the film to the substrate glass and metal oxides, which may be used singly or in combination. Films that use a glass, or frit, are referred to as fritted materials, and have a relatively low... 

Compression Seals. These are preformed cellular elastomeric products available in either precompressed or uncompressed forms. The sealant may utilize external and/or internal adhesive elements. The seal is obtained by placing the preformed material in compression between the joining surfaces. Exact storage, handling, and application instructions must be followed. 

---