ABSTRACT

Functional Materials A wide variety of functional materials are available for each category of inks.2 Dielectric inks, for example, include capacitor materials with high dielectric constants, low dielectric constant insulator layers, and

low melting point sealing glasses. Resistor inks are the most homogenous group based primarily on ruthenium dioxide as the functional material. Conductors serve the widest range of functions within the circuit; however, it is desirable to print the fewest number of layers, so compromises must be made in choosing an alloy to satisfy all the demands on the conductor layers. Interconnection is the overall purpose of the conductor films and in this role the film must also function as a resistor, capacitor, or inductor termination, wire bond pad, component lead pad, die bond pad, and via fill. Each of these applications has distinct requirements for adhesion and continuity with solder, gold wire, aluminum wire, conductive adhesive, and other thick film layers.