A resistor is a passive electrical component.
Depending on the application, a resistor can be responsible for:
- limiting the amount of current
- dividing voltage in networks
- using timers or filters together with capacitors
- converting electrical energy into heat
A printed resistor is created by printing the surface between two terminators (copper or similar material with high conductance) with a polymer paste of specific conductivity.
A major advantage of printed resistors is their high degree of reliability in dealing with variable thermal loads; this was demonstrated in temperature cycling tests (-40 °C / + 125 °C) up to 3,000 cycles. Conventional systems are made up of very different kinds of materials (ceramics, FR4, solder) and have very different degrees of linear expansion under changing temperatures. This can result in premature breakdown of the assembly. Conductive polymers and circuit boards have almost identical properties, so this problem does not occur under the conditions mentioned above.
Standard resistors for pull up / pull down applications can be manufactured with a tolerance of ± 30 % without laser trimming. For higher-quality applications, laser trimming can help reduce the tolerance of resistors to ± 5 %, over the entire life expectancy, even under extreme climatic conditions (40°C / 92% rel. humidity / 1000h).
Resistors can be positioned on the inner layers of a multilayer. This saves scarce space on the outer layers for component assembly.