A resistor is a type of electrical component that may be implemented within a system in order to provide resistance to a network. Depending on the type of resistor and its characteristics, such components may be used to divide voltages, terminate transmission lines, adjust signal levels, and much more. As the most common types of resistors on the market, thin and thick film resistors cater to a variety of applications with their characteristics and capabilities.
To construct a thin or thick film resistor, resistive film or paste is placed on a ceramic substrate alongside a mixture of conductive materials and glass. While thin and thick film resistors have very similar appearances, their method of manufacturing and operational characteristics differ highly from one another. With the thin film resistor, the thickness of its conductive layer never exceeds 0.1 micrometers. Meanwhile, the thick film resistor will often have a layer that is a thousand times the thickness. While these differences may seem minimal, they have great effects on their resistive properties and operations.
To achieve such varying thicknesses, different methods are used to produce the thin and thick film resistor. When producing the film for a thin film resistor, a layer of metallic film is applied to a ceramic substrate through the use of vacuum deposition. By using such a precise method, the metallic film is uniform across the substrate and never surpasses 0.1 micrometers of thickness. Generally, Nickel and Chromium alloys serve as the most popular materials for the layer, and they can be applied in varying thicknesses to adjust resistance values. As the application of the materials is uniform, it is simply a matter or trimming the layer to lower the resistance.
Due to the method that is used for manufacturing thin film resistors, their resulting characteristics allow them to excel in precision applications. With their ability to operate with low amounts of noise, high tolerances, and an optimal temperature coefficient, such resistors may be used for medical equipment, measuring devices, and much more. As compared to the thick film resistor, thin film resistors are more efficient for high frequency applications.
Since the creation of the thick film resistor, it has quickly garnered popularity and has become the most widely used type for electronics. For their resistive layer, a mixture of metal oxide resistor and glass is deposited onto a substrate through firing. Due to the extreme heat at which the layer is applied, the film will exhibit glass-like properties which help shield the component from the effects of moisture. Generally, thick film resistors have a layer that is around 100 micrometers, and resistance values may be adjusted by adding more materials to the layer.
Generally, the thick film resistor has a temperature coefficient that sits between 50 ppm and 200 ppm/K, as well as exhibits a tolerance between 1% and 5%. Due to these characteristics, thick film resistor networks are commonly implemented in any electronic device that utilizes AC power or a battery. Due to their ease of production and wide availability on the market, procuring thick film resistors (SMD) can be very cheap.