Passive Components

Passive electronic components are used in all types of electronic circuitry, but are often overlooked in their importance to the operation of the circuit. The passive electronic component stands ready to perform in a circuit when provided an external voltage or current stimulus. The active component, on the other hand, is often part of the power supply providing the stimulus for the passive circuit. Semiconductors are probably the most commonly used active electronic component.

Passive components, like resistors and transformers, are often constructed using resistance wire for resistors and magnet wire for transformers. Various metal foils are often used in wound film capacitor construction.

Another construction method used for metal film resistors and tantalum capacitors is to deposit either metal or dielectric film using vacuum thin film sputtering techniques. Vacuum sputtering is a precise and accurate means of construction. No wire or foil windings are necessary with this type of resistor or capacitor construction.

When ceramic substrates are used and RF or microwave frequency performance is desired, thick film construction of the metal conductors becomes a cost effective method for products like attenuators and terminations.

Thin film construction, while more costly, provides the best performance for RF/microwave resistors since the thin film morphology can be made very homogenous. The created homogenous resistor surface then distributes the applied power very uniformly eliminating hot spots that often lead to poor MTBF’s and early product failures. Since thin film resistors are created using optical masking techniques, very small and accurate resistors can be constructed.