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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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Radio Frequency (RF)

Electromagnetic frequencies ranging from 20kHz (kilohertz) to 300GHz (gigahertz). Energy from currents in these frequencies radiates into space as electromagnetic waves. These waves are used to transmit both radio and television. These frequencies start above audio signals and finish below infrared light frequencies - a comprehensive frequency chart is given in Wikipedia (external site link).

Radio Frequency Interference (RFI)

A specific form of Electromagnetic Interference, when the interfering signal is located in the radio frequency spectrum. Generally associated with the interference to signal integrity due to transmission sources (TV, radio, mobile/cell phone, Bluetooth, Wi-Fi, etc.). Any item that transmits will require some form of shielding for the rest of the circuitry to protect it from its own RFI. Also, in many countries the equipment needs to meet standards that define the amount of interference permissible (see Electromagnetic Compatibility).


Usually refers to the qualifying processes that have to be repeated on safety critical systems, whenever a part has to be replaced by an alternative, either from a different supplier or of a different design, or both. Typical industries include (but are not limited to): Aerospace, Automotive, Defense, Medical.


An acronym for "Registration, Evaluation, Authorisation and restriction of CHemicals" - a legislation in place throughout Europe that has a number of aims. Registration has compiled a comprehensive list of all substances used in the manufacture of anything sold in the EU. Further parts of this legislation evaluate the effects of each substance on humans and the environment, and restricts the usage of any substances found to be harmful. The legislation is Regulation (EC) No 1907/2006. Harwin have a support article on REACH.

Reflow Solder

The most common solder process used on Surface Mount PCBs and devices. The solder is applied in a paste format directly to the PCB, and the devices are placed on top of that. Then the whole board with the devices is passed through a solder oven on a conveyor belt. The ambient heat inside the oven turns the paste into solder liquid and creates a solder joint. The PCB carries on to an area where it is then cooled and the solder joint solidifies.


A desirable condition such that the device will provide the specified performance for a specified time under specified conditions. A factor of quality of a connector.

Research & Development

Any department or work that involves working on new technologies, new product concepts, new manufacturing methods, or development of any existing products or methods.

Resistance (Electrical)

A measure of the difficulty with which current flows through an object. Resistance is caused by both the shape of the conducting element, and by the physical properties of the material itself (how conductive is the material). Other factors can also influence the resistance, such as temperature, by influencing the conductivity of the material. The SI unit of resistance is the Ohm (Ω).

Restriction List

A list of substances maintained as part of REACH. These substances are restricted (in various applications or total ban) - each substance has a Conditions document detailing the restriction on the substance.

Ribbon Cable

A specific form of multicore cable, also know as a multi-wire planar cable. The conductors are laid parallel, and the insulation covers each conductor separately, but also bridges between the contacts. The flat top and bottom sides of the ribbon cable can be completely flat, but are normally ridged with valleys between each conductor. The conductors can be solid or stranded. Typically the cable is grey, with one edge showing a red stripe for contact number one - however, rainbow ribbon cable is also available. Adding a connector to a ribbon cable can be done as discrete connections (by splitting up the end of the ribbon), but normally an IDC would be used.


An acronym for "Restriction of Hazardous Substances" - a legislation in place throughout Europe that restricts the use of 10 substances in electrical and electronic equipment. The current version is Directive 2011/65/EU, with amendment Directive 2015/863. Commonly, these directives are referred to as RoHS 2 and RoHS 3. Harwin have a support article on RoHS.

Rugged Connector

A connector designed with harsh or extreme environments in mind, with certain additional design features or material considerations applied to help resist those environments. The harsh environment factors include (but are not limited to): vibration, shock (mechanical), operating temperature range, physical abuse, untrained operator handling.