Screen printing adhesion element

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]. 

Having a complete functional textile solar cell motivates the researchers to attempt an approach for direct incorporation of photovoltaic cell elements onto the textile. The textile substrates inherently scatter most part of the incident light outward. Therefore, it was found necessary to apply a layer of the very flexible polymer PE onto the textile substrate to have a surface compatible with a layered device. The textile-PE substrate was plasma treated before application of the transparent PEDOT electrode in order to obtain good adhesion of the PEDOT layer to the PE carrier. Then screen-printing was employed for the application of the active polymer poly[2-methoxy-5-(2 -ethylhexyloxy)-p-phenylene vinylene] (MEH-PPV) [33]. 

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