Continuous Inkjet

Continuous inkjet (CIJ) printing, 9 222 Continuous ion-exchange systems,... 

Piezo. This is the same basic print head technology as in continuous inkjet. The ink jet droplets are forced out through the nozzle after an electrical signal to the piezoelectric crystal causes a pressure wave to be set up in the ink (Figure 2.35b). The wave can be produced in the bend mode, as in Figure 2.35b or in a push or shear mode. An important variation on piezo technology is the Xaar... 

As the name implies, continuous inkjet technology ejects drops continuously (Fig. lA). These drops are then either directed to the substrate or to a collector for recirculation and reuse. Drop-on-demand technology ejects drops only when required " (Fig. IB). 

A further distinction, when referring to inkjet inks, is the printing mechanism. Solvent inks are used widely in drop-on-demand piezo inkjet printing (DOD PIJ) and in continuous inkjet (CIJ). To a lesser extent there is an effort to introduce solvents into thermal inkjet drop-on-demand (DOD TIJ). 

FORMULATING SOLVENT INKS FOR CONTINUOUS INKJET PRINTERS... 

Several types of fluids may be jetted via inkjet heads, which can be of the continuous inkjet variety (CIJ, primarily aqueous or solvent-based), thermal inkjet (TIJ, primarily aqueous, but some solvent and UV/aqueous hybrids exist), or piezoelectric drop-on-demand (DOD, aqueous, solvent, oil, UV curable). While there are advantages and disadvantages for each type of hardware and fluid, a clear leader in growth has emerged from the list. UV curable inkjet... 

The early products were known as continuous inkjet printers because they relied on a steady stream of droplets. Only a small fraction of these drops are needed for printing and the rest of the drops are deflected away from the paper into a gutter, where the ink is collected and possibly recirculated back to a reservoir. 

FIGURE 9 A binary deflection continuous inkjet print head. [From Le, H. R (1998). J. Imaging Sci. Technol. 42, 49-62 by permission of the copyright holder, the Society for Imaging Science and Technology.]... 

The transfer process of ink jet printing is one of removing a drop of liquid ink from the bulk and giving it a velocity of sufficient precision and magnitude to place it on a substrate in close proximity to but not touching the printhead. There are three broad techniques continuous, electrostatic, and drop on demand. Continuous inkjet printing, because of its intrinsic high drop rate, has tended to find more applications... 

Nanoparticles can be deposited onto a substrate by spin coating or inkjet printing a colloidal solution and can be sintered into a continuous conductive film during the subsequent annealing step. Coalescence of individual... 

Inkjet printing as its name implies is a printing method in which a jet of ink is fired, in the form of extremely small droplets, onto a receiving medium. " It is a primary printing technology as the image is printed directly onto the substrate without any intermediate steps. The ink can be supplied in either a continuous manner or inter-... 

Generally, ink dyes for ink jet applications and writing, drawing, or marking materials are selected from food, acid, direct, sulfur, and reactive dyes. The choice of dye depends on the application and the ink used, whether it is aqueous, solvent based, or hot melt, and on the printer type continuous ink jet or drop-on-demand, piezo or thermal inkjet. 

While these polymeric materials hold promise for low-cost electronics and simplified device processing, they still suffer from lower performance than conventional inorganic semiconductors. As the development of these novel materials continues, an alternative technology incorporating patterning schemes such as inkjet printing and conventional vacuum deposited thin films, may provide the required overlap of performance with low-cost fabrication of microelectronic circuits on large-area platforms. 

While all inkjet technologies can fundamentally be described as the digitally controlled ejection of drops of fluid from a print head onto a substrate, this is accomplished in a variety of ways. Industrial inkjet is broadly and most typically classified as either continuous (CIJ) or drop-on-demand (DOD), with variants within each classification. 

The current high price of commercially available conductive inkjet inks is hindering development of new applications, thus there is a demand for less expensive solutions. R D efforts will continue to be devoted to development of jettable conductive inks, and new processes and/or cheaper materials, such as copper or organic conductors, are expected to find their way into this market. 

In conclusion, the huge and rapidly growing markets for printed electronics are providing the motivation for new developments in the field of conductive inkjet materials and technologies. In particular, conductive inkjet inks will find their place in new generation photovoltaics, OLEDs, and flexible consumer products. Inkjet printing of electronics will continue to offer tremendous opportunities in academia and industry in order to solve problems, to improve existing applications, and even to create new apphcations enabled by novel techniques and approaches. 

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