A chip resistor is a very compact, surface mounted electronic component designed to offer a known resistance to any electrical current flowing through it. A mini resistor of this kind are designed to have the same physical characteristics or form factor as other surface mount devices (SMD) to conform to SMD circuit board geometry. It differs from conventional axial lead resistors in physical form only and fulfill the same functions in electronic circuits. Chip resistors are available in several package formats and with a range of specialist features.
A chip resistor is a small, flat component typically slightly bigger than a pin head. It has a lead at either end designed specifically for surface mounting. This printed circuit board (PCB) construction method not only allows for more complex circuitry to be accommodated in any given area but also facilitates multi-layer PCB construction. Older methods of PCB construction called for component leads to be inserted through holes in the board and soldered into place on the reverse surface. In modern surface mount technology, these components are soldered directly onto the conductive tracks on the same side as they are mounted.
The larger, cylindrical axial lead resistors would not allow for this type of PCB construction which led to the development of the chip resistor. Chip resistors are constructed using thin film or sputtering techniques where vacuum deposition is used to apply a resistive carbon composite, ceramic, or metallic material onto an insulating backing. A set of terminal leads are attached to the resistive layer, and the completed resistor is the encased in a protective coating. The materials used to produce chip resistors typically comply with most international safety standards and contain minimal quantities of lead, cadmium and hexavalent chromium.
There two most widely used chip resistor formats are the single resistor and the chip resistor array. The single resistor is a passive, set value component, and the resistor array consists of several identical value resistors in a single package. Single resistors have one set of terminal leads whereas chip resistor arrays are in-line packages with several pins representing one common pin and one for each resistor in the array.
There are several categories of chip resistor all of which cater to a range of application requirements. These include purpose designed power supply, telecommunications, high frequency, current sensing, automotive, medical and aerospace components. Chip resistors may also include unique features such as integral heat sinks, water cooling facilities, fireproof casings, or coatings and non-inductive shielding.