Contact pads or bond pads are small, conductive surface areas of a

printed circuit board A printed circuit board (PCB), also called printed wiring board (PWB), is a Lamination, laminated sandwich structure of electrical conduction, conductive and Insulator (electricity), insulating layers, each with a pattern of traces, planes ...

(PCB) or die of an

integrated circuit An integrated circuit (IC), also known as a microchip or simply chip, is a set of electronic circuits, consisting of various electronic components (such as transistors, resistors, and capacitors) and their interconnections. These components a ...

. They are often made of gold, copper, or aluminum and measure mere

micrometres The micrometre (English in the Commonwealth of Nations, Commonwealth English as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American English), also commonly known by the non-SI term micron, is a uni ...

wide. Pads are positioned on the edges of die, to facilitate connections without shorting. Contact pads exist to provide a larger surface area for connections to a microchip or PCB, allowing for the input and output of data and power. Possible methods of connecting contact pads to a system include

soldering Soldering (; ) is a process of joining two metal surfaces together using a filler metal called solder. The soldering process involves heating the surfaces to be joined and melting the solder, which is then allowed to cool and solidify, creatin ...

, wirebonding, or

flip chip Flip chip, also known as controlled collapse chip connection or its abbreviation, C4, is a method for interconnecting dies such as semiconductor devices, IC chips, integrated passive devices and microelectromechanical systems (MEMS), to exter ...

mounting. Contact pads are created alongside a chip's functional structure during the

photolithography Photolithography (also known as optical lithography) is a process used in the manufacturing of integrated circuits. It involves using light to transfer a pattern onto a substrate, typically a silicon wafer. The process begins with a photosensiti ...

steps of the

fabrication Fabrication may refer to: * Manufacturing, specifically the crafting of individual parts as a solo product or as part of a larger combined product. Processes in arts, crafts and manufacturing *Semiconductor device fabrication, the process used t ...

process, and afterwards they are tested. During the test process, contact pads are probed with the needles of a

probe card A probe card (commonly referred to as a DUT board) is used in automated integrated circuit testing. It is an interface between an electronic test system and a semiconductor Wafer (electronics), wafer. Use and manufacture A probe card or DUT b ...

Automatic Test Equipment Automatic test equipment or automated test equipment (ATE) is any apparatus that performs tests on a device, known as the device under test (DUT), equipment under test (EUT) or unit under test (UUT), using automation to quickly perform measure ...

in order to check for faults via electrical resistance.

Further reading