supplementary

Glossary of terms used in electronics: E

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eco-efficiency: The delivery of competitively priced goods and services that satisfy human needs and bring quality of life, while progressively reducing environmental impacts and resource intensity throughout the life cycle, to a level at least in line with the earth’s estimated carrying capacity.

edge contact See gold finger.

edge-card connector A pluggable connector specifically used for making non-permanent interconnections to contacts plated on the edge of a circuit board.

EIA = Electronics Industry Association A trade association representing the US high-technology community. Responsible for publishing numerous design standards.

ejector See board extractor.

electrical noise Variations from a nominal operational voltage or current value on a power or signal line. Circuits are usually designed to function within a noise tolerance band or allowable noise budget.

(electrochemical) migration Gradual movement of corrosive or conductive materials that may create unwanted circuit paths and cause performance degradation or failure. Migration is usually caused by exposure of existing contaminant residues or bare metal surfaces to a combination of high humidity, elevated temperatures, and an electrical potential.

electroless plating A process for chemically depositing metallic material on a nonconductive surface. It is primarily used for metallising holes in a circuit board to prepare them for addition of electroplated metal.

electroplating ( electrolytic plating) Direct deposition of metallic materials on a surface using an electrolytic process. It involves passing a current between an anode and a cathode through a conductive solution containing metal ions. The conductive surface of the laminate (circuit board) to be plated is the negative electrode (cathode).

ELV(s): End of Life Vehicle – scrap cars and other vehicles. The subject of an EU Directive.

EMAS: (European) Eco-management and Audit Scheme. A European voluntary scheme for industrial sites. To register under EMAS your company should have a clearly defined strategy for environmental management, complete with quantified objectives.

EMI/EMC Electromagnetic interference (EMI) is the detrimental effect stray radiated electromagnetic energy has on the performance of a circuit. Electromagnetic compatibility (EMC) involves the control and reduction of this energy.

EMS: Environmental Management Systems: the part of an overall management system that includes organisational structure, planning activities, responsibilities, practices, procedures, processes and procedures for developing, implementing, achieving, reviewing and maintaining the environmental policy (see ISO 14001).

emulator A representation (hardware or software) of an electronic device or function that simulates its behaviour. It is used to verify performance of a circuit design by analysis.

emulsion 1) A stable combination of two or more immiscible (unmixable) materials suspended in a surrounding medium.

end-to-end design Integrating the inputs and outputs of CAE, CAD and CAM software packages to allow design to flow smoothly in both directions with minimal manual intervention.

In the field of board design, end-to-end design sometimes refers to only the electronic schematic/PCB layout interface. Childers points out that this is a narrow view of the potentialities of the concept. For example, end-to-end systems can also implement electronic circuit simulation, parts procurement and beyond.

energy recovery: The recovery of useful energy in the form of heat and/or power from burning waste. Generally applied to incineration, but can also include the combustion of landfill gas and gas produced during anaerobic digestion.

engineering change notice (order) (ECN or ECO) A document that describes and controls engineering design or documentation changes.

environment The surrounding conditions in which an assembly exists and functions, including temperature, humidity, altitude, vibration, shock, etc.

Environment Agency: The principal environmental regulator in England and Wales. Established in April 1996 to combine the functions of former waste regulation authorities, the National Rivers Authority and Her Majesty’s Inspectorate of Pollution. Intended to promote improved waste management and consistency in waste regulation across England and Wales.

environmental accounting: Any quantitative approach to linking financial and environmental performance.

environmental footprint: The impact of an organisation in environmental terms (resource use, waste generation, physical environmental changes etc).

Environmental Technology Best Practice Programme (ETBPP): A Government (DEFRA) initiative to demonstrate the benefits of reducing resource use and environmental impact to companies across the whole of the UK.

epoxy(epoxide) A family of thermosetting resin materials having high strength and low shrinkage during curing; used as a coating or adhesive.

EPROM Electrically Programmable Read Only Memory: a device that allows data stored in it to be erased and new data input to it, usually by exposure to ultraviolet radiation.

ESD = electrostatic discharge The rapid transfer of a voltage potential into a circuit or component. Depending on its sensitivity to ESD, the overstress can permanently damage a component.

etch-back Chemical removal of dielectric material in the barrels of holes in a multilayer board. The purpose is to increase exposure of internal conductor areas (usually pads) to enhance physical and electrical contact with metal to be plated in those holes.

etch (etching) Chemical removal of material, usually associated with defining conductor patterns on a circuit board.

EU Directive: A European Union (formerly EC-European Community) legal instruction, binding on all Member States but which must be implemented through national legislation within a prescribed time-scale.

eutectic (alloy) An alloy of two or more metals that has a lower melting point than either of its constituents. The alloy can pass (reversibly) from solid into the liquid state without an intermediate plastic phase. Eutectic tin-lead solder is usually regarded as having the proportion 63% tin to 37% lead.

EWC: European Waste Catalogue. A list of codes and waste descriptions establishes under European law. It includes the hazardous waste list.

Excellon data format A proprietary data format structure that is used to convert physical hole data (location, diameter, etc.) into a format that a software program can use to drive a numerically controlled (NC) drilling machine. It is considered a de facto industry standard.

excess solder A solder connection characterised by the complete obscuring of the connected metal surfaces or by the presence of solder beyond the connection area. The connection appears as a rounded, piled-up, convex solder fillet, and it is impossible to determine if a proper bond has been achieved.

exempt facility: A waste recovery operation (also occasionally certain disposal at the waste producer and some storage activities) registered with, but not licensed by, the Environment Agency. Exempt facilities are subject to general rules (e.g. on the types and quantities of wastes received).

eyelet A short metallic tube with ends that can be formed outward to fasten it within a hole in the base laminate of a printed circuit board.

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