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Definitions for jargon, scientific terms and phrases used at Harwin and across the connector and electronics industries.

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Airflow Path

To assist with cooling, PCB designers may need to look at how free or forced air (by a fan) will travel around the layout of the PCB. It might be necessary to move taller or bigger objects around in case they obstruct the flow of the air and diminish the effectiveness of the air cooling.

Alignment Features

In order to make sure that connectors mate successfully, they first need to be aligned to each other. To assist with getting the connectors successfully mated, additional features can be designed onto one or both sides of the connector halves. These can include oversize chamfers, pegs or posts, or even separate posts mounted on the PCB that line up with a hole in the mating PCB.

Alignment Posts

Normally long posts that extend past the mating face of a connector, they are additional housing features. They can be either metal or plastic, do not carry current, and mate with plain holes in the mating connector. These help line up the two mating connectors before the contacts touch, helping to avoid misalignment and potential damage to the contacts. They can also assist with blind mating.

Alternating Current (AC)

An electric current whose electrons periodically reverse their flow. The most common form of AC alternates in a sine wave.


The base SI unit of electric current (symbol A), defined as "that constant current which, if maintained in two straight parallel conductors of infinite length, of negligible circular cross-section, and placed one meter apart in vacuum, would produce between these conductors a force equal to 2×10−7 newtons per meter of length."

The ampere is often shortened to "amp" (as in "Current rating of 3 amps"). It is named after André-Marie Ampère (1775–1836), a French mathematician and physicist, who is considered to be the father of electrodynamics. Ampère's force law states that there is an attractive or repulsive force between two parallel wires carrying an electric current; this force is used in the formal definition of the ampere.

As this is not a feasible measurement to reproduce, the ampere standard is practically realized through its relationship to the Volt (voltage) and the Ohm (resistance), as both of these can be tied to physical phenomena that are relatively easy to reproduce.

Analog signal (Analogue)

A continuous electrical signal current that can vary by any amount - compared to digital, which can only operate at discrete defined values. In practice, all signals are analog, but degradation or noise is easier to spot in digital signals as it will show up as any deviation from the expected values, and the signal can be corrected back to the digital value. Analog signals will always contain noise, which accumulates along the signal path, and which cannot be distinguished from the original signal. Shielding can be utilized to help prevent noise (caused by interference), but there is no reliable method to restore the signal loss.


A 1.27mm pitch (0.05" or half-pitch) PCB connector system from Harwin based on simple pin header and socket styles. Part numbers all start with either M50 or M52. The connectors are available in Board-to-Board or Cable-To-Board styles, and are generally suited for static equipment and consumer electronics. See also Archer Kontrol.

Archer Kontrol

A 1.27mm pitch (0.05" or half-pitch) PCB connector system from Harwin. Part numbers all start with M55. The connectors are available in Board-to-Board with a choice of vertical or horizontal orientation on both male and female connectors. Variable mating heights are also possible, up to 20mm. The range has improved functionality over the basic Archer ranges, and includes polarization, shrouding and location pegs on all connectors.


A quality management system similar to ISO 9001, but with additional requirements and an emphasis on continuous improvement. Originally designed for the Aerospace market, it is becoming recognized in other markets and within the component supply chain. The version was updated from C to D in 2017, and further work and audits must be completed for companies wishing to upgrade their certification to the new version. EN 9100 is the international version, and effectively identical. Information on Harwin's AS9100 certification can be found on the Quality page.

Automated Optical Inspection (AOI)

An additional automated process that can be added to the end of a solder process (or other manufacturing processes). The setup consists of a camera and a PC. The camera takes an image of the part that needs inspection, and the PC compares this image to a bank of acceptable images or other criteria. Using these criteria, the PC can then confirm if the assembly passes inspection. Much faster and more repeatable / less prone to interpretation than manual inspection.


Any procedure that is carried out solely or with the assistance of machinery that follows a program, rather than needing an operator to operate a control for every function.