Glossary
Welcome to the MPE Electronics Glossary of Terms. Here you will find an explanation of many of the technical terms which relate to the contract electronics manufacturing process.
Choose from the following categories:
Components
Electronics Production
General Terms
If you can’t find the information that you need, however, a member of our team is always on hand to help.
Get in touch with us on 01825 764822 or email: enquiries@mpe-electronics.co.uk.
Components
| Anode | The positive lead of a polarised component |
| BGA | Ball Grid Array – a component with bottom terminations shaped as balls. |
| Cathode | The negative lead of a polarised component |
| Chip Component | A component package with metal terminations on either end. The body is usually made of ceramic. Mostly resistors or capacitors. |
| Diodes | An electronic component that only allows electricity through one way. |
| DIP | Dual in-line is a through-hole package with two rows of leads from the base in standard spacing between the leads and row. |
| Fine Pitch | A SMD component with a lead pitch less than 0.625mm |
| Gull Wing Lead | A component termination in the shape of a ‘L’ where the toe of the lead faces outward, away from the component body. |
| IC | Integrated Circuit – a collection of electronic components on a small flat piece of semiconductor material, usually silicon |
| J-Lead Component | A SMD component with leads formed like the letter ‘J’, these components are also called PLCC’s. |
| LED | Light Emitting Diode – A type of diode which emits light when current is flowing through it |
| MELF | Metal Electrode Face – a round SMD component with metal terminations on both ends |
| PCB | Printed Circuit Board – Bare PCB with no components soldered on to it. |
| PLCC’s | Plastic Leaded Chip Carrier |
| Polarity | A component with a positive and a negative connection |
| QFN | Abbreviation for Quad Fine pitch No-Lead, leadless quad packages soldered directly on the PCB, generally with a central thermal pad and peripheral terminations. |
| QFP | Abbreviation for Quad Flat Pack, a SMD component with Gull-Wing leads exciting all 4 sides of the component body. |
| SOIC | Small Outline Integrated Circuit |
| SMD | Surface Mounted Devices – Components that are mounted directly onto lands that serve as mounting points. |
Electronics Production
| AOI | Automated Optical Inspection – a process using a set of cameras that autonomously scan the PCB assembly for components that will lead to catastrophic failure. |
| ATE | Automated Test Equipment – Equipment that automatically tests and analyzes functional parameters to evaluate performance of the tested electronic device. |
| Bare Board Test | A method automatically testing all connected points on a PCB to ensure connectivity and quality. |
| Cold Solder Joint | A solder joint which is characterised by a grainy appearance resulting from insufficient thermal energy introduced into the solder connection. Cold solder joints are a reliability risk. |
| Delamination | A planar separation between layers within a PCB. |
| Dewetting | A wetting mechanism where a part of the solder pulls back at solidification and only a thin layer of solder maintains on the surface. |
| Flux | A chemical agent used for cleaning, wetting improvement and protection of a solder connection. |
| Functional Test | The electrical testing of an assembled electronic device with simulated function generated by the test hardware and software. |
| In-Circuit Test | Electrical test of individual component or part of the circuit board instead of testing the whole circuit. |
| Measling | A localised separation of fibre bundles at fibre bundle intersections within a PCB, usually visible as white squares within the PCB structure. |
| Non wetting | The inability to wet a surface with solder, see also Wetting |
| Reflow Soldering | Soldering method in which the assembly to be soldered passes through a convection oven system. |
| SMT | Surface Mount Technology – An installation method where the components are mounted directly on the surface of a PCB. |
| Solder Paste | A mixture of solder powder and flux used for certain soldering applications. |
| Solder Resist | Also known as solder mask – A heat-resisting coating material applied to areas of a PCB to prevent solder to be deposited upon these areas. |
| Thermal Profile | A complex set of time/temperature related data to characterize a soldering process. |
| THT | Through-Hole Technology – A technique where components are placed and soldered in holes in the PCB structure. |
| Tin Whisker | Microscopic tin fibers growing from the surface of pure tin surfaces, caused by compressive stress in the metal. |
| Tombstoning | The situation where a leadless component has only one termination soldered due to tilting of the component. |
| Wave Soldering | Soldering method in which the assembly to be soldered passes through a bath of molten solder. |
| Wetting | The ability of a liquid to form an interface with a solid surface. |
| Wetting Angle | The angle of the wetted solder and the base surface |
General Terms
| BOM | Bill Of Materials – An Itemised list of components used in the manufacture of a Printed Circuit Board Assembly (PCBA), usually showing the circuit reference. |
| DFM | Design for Manufacturing – is the process of designing products for ease of manufacturing with an end goal of making a better product at a lower cost. |
| PCBA | Printed Circuit Board Assembly – A PCB that has had electronic components soldered on to it. |
| ESD | Electrostatic Discharge – The rapid transfer of a static charge from one object to another. |
| Footprint | Geometry of pads for soldering electronic components. The land pattern on the PCB matches the arrangement of leads on the component. |
| FR4 | The most common base material a PCB is made from. Made from woven glass fibre impregnated with epoxy resin. |
| Gerber File | Gerber files contain information such as copper traces, vias, pads, solder mask and silk screen images for each physical board layer as well as drill data etc. |
| Multilayer PCB | A PCB made up by laminating thin PCBs each with a different part of a circuit on each and interconnecting them with via holes. |
| NPTH | Non-plated through-hole. |
| RoHS | Abbreviation of Restriction of Hazardous Substances. |
| RoHS directive | A European directive in which the use of some substances is prohibited from use in products sold on the European market. |
| Pad | A pad is an exposed area of metal on a circuit board that the component lead is soldered to. |
| Pin (pinout) | Part of an electronic component which is soldered to the board. |
| PTH | Plated-through Hole – A metalized structure formed in a PCB by a plating process where a base metal is deposited inside drilled holes, thus connecting external and internal layers of copper foil. |
| Silkscreen | Also known as legend – screen printed labeling used to denote where components should be placed, orientation of components, version of the board, manufacturer, test points and other useful information. |
