Thick-film resistor conduction process

Thick-film resistors are made by diluting a conductive oxide with an electrical insulator such as glass. (The practical aspects of thick-film processing were described in... 

Resinates. Precious metal resinates are organometaUic compounds in which the metal atom is attached to a sulfur or oxygen atom linked to a carbon atom. When these compounds are thermally decomposed, a film is deposited on the substrate. The thermal decomposition process takes place between 250 and 500°C. Under these conditions, noble metal compounds deposit metallic films while other precursor materials deposit metal oxide films. Ruthenium resinates can be used to formulate thick-film resistors. Ruthenium resinates decompose during firing and form an RuOj conductive phase. Thick and thin film ruthenium resinate-based resistors are extensively used in thermal printhead applications. ... 

Polymer thick films also perform conductor, resistor, and dielectric functions, but here the polymeric resins remain an integral part after curing. Owing to the relatively low (120—165°C) processing temperatures, both plastic and ceramic substrates can be used, leading to overall low costs in materials and fabrication. A common conductive composition for flexible membrane switches in touch keyboards uses fine silver particles in a thermoplastic or thermoset polymeric binder. 

Of the mass-transfer dispensing methods, screen printing and stencil printing are the oldest and most widely used. Screen printing has been used for over 40 years in the electronics industry to apply thick-film conductors, resistors, and dielectrics in fabricating circuits on ceramic and plastic-laminate substrates. Screen printing is also used as a batch process for depositing electrically conductive and insulative adhesives to interconnect devices on thin-film and thick-film hybrid microcircuits. 

Screen printing of conductive andinsulative adhesives has been used for decades in the assembly ofhybridmicrocircuit and multichip modules. Since screen-printing processes are also used to deposit thick-film conductors, resistors, and dielectrics, the processes are fully compatible and cost effective in the production of hybrid microcircuits. Screen printing and stencil printing are both batch processes that are usually less expensive and... 

One alternative to the electroless process utilizes conductive polymers. Polymer thick film (PTF) technology is a method of screening polymer conductors, resistors, dielectrics, and protective coatings on a substrate or printed wire board to create basic circuitry or interconnections. The use of screened-on conductive films in place of the formaldehyde-containing electroless copper process is gaining acceptance in Asia (more so than in the United States at this time). 

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