A chemical added to the cleaning solution to lower surface tension and to promote wetting.

The natural, inward, molecular attraction force that inhibits the spread of a liquid at its interface with a solid material.

The electrical connection of components to the surface of a conductive pattern that does notutilize component holes.

A component lead wire that extends through a hole in a printed board and its lead extension is flattened(swaged)to secure the component to the board duringmanufacturing operations.

The passage of current over the boundary surface of an insulator as distinguished from passage through its volume.

A measure in ohms of an insulating material’s (as in FR-4) electrical resistance between conductors.

Test for the level of resistance of an insulating material, such as FR-4.between conducting members of a board (traces, contacts).

A hole in a printed board that has its inside surface plated or otherwise reinforced.

A process for obtaining conductive patterns by selective removal of unwanted areas of conductive foil from a metal clad base material.

See Base Material.

A type of transmission line configuration which consists of a single narrow conductor parallel and equidistant to two parallel ground planes.

The deformation resulting from a stress.

A component lead that extends through a hole and is terminated without subsequent forming.

A method by which successive exposures of a single image are made to produce a multiple-image production master.

The making of solder connections by sequentially using solder alloys with successively lower melting temperatures.

The use of statistical techniques to analyse the outputs of processes with the results guiding actions taken to adjust and/or maintain a state of quality control.

Wiring which is produced by die stamping and which is bonded to an insulating base.

See Cross-talk.

The highest temperature at which filler metal(Solder) is completely solid.

A method of connecting a solid wire to a square, rectangular, or V-shaped terminal by tightly wrapping the wire around the terminal with a special tool.

A process of joining metallic surfaces with solder, without the melting of the base metals.

The portion of a soldering iron that is used for the application of the heat that melts the solder.

The ability of a metal to be wetted by molten solder.

The evaluation of a metal to determine its ability to be wetted by solder.

The side of a printed board which is opposite to the component side.

An ink, lacquer, photo-resist or metal coating which is not wetted by molten solder.It is applied to specific areas of a PCB to stop them from being solder-coated, usually when mass soldering.

An undesirable protrusion of solder from a solidified solder joint or coating.

A core of solder in a plated through-hole.

Finely divided particles of solder, with additives to promote wetting and to control viscosity, tackiness, drying rate, etc.

Liquid formulations that are used in intermix wave soldering and as coverings on static and wave soldering pots in order to eliminate dross and to reduce surface tension during the soldering process.

Coating with mask and insulate areas of a circuit pattern where solder is not desired.

A screening defect characterized by prints having jagged edges, the result of incorrect moving pressure.

The process of immersing printed circuit boards into hot liquids. Often referred to as HASL or HAL (Hot Air Levelling).

A preferable concave surface of solder that is at the interconnection of the metal surfaces of a solder connection.

A small hole that penetrates from the surface of a solder connection to a void of indeterminate size within the solder connection (process indicator).

The unwanted formation of a conductive path of solder between conductors.

A metal alloy with a melting temperature that is below 450℃.

The period after pre-heat and before re-flow peak temperature where the internal temperature differences between parts allowed to equalize.

The return of a stencil to normal level after deflection by the pressure of the squeegee moving across the surface.

The space between the top surface of the substrate and the underside of the stencil when the squeegee is not in play.

Surface Mount Technology. Defines the entire body of processes and components which create printed circuit assemblies without components with leads that pierce the board.

Solder Mask Over Bare Copper.

Resin, smeared over the edge of an internal copper layer of a multi-layer board during drilling, which prevents the layer from making electrical contact with the barrel of the hole.

Surface Mounted Device. Any component or hardware element designed to be mounted to a printed circuit board (PCB) without penetrating the board.

A spreading of the solder paste after printing but before re-flow soldering. If excessive, a loss of definition may result.

A production master used in the process of making a single printed board.

A printed board with a conductive pattern on one side only.

The process of creating a virtual representation(a computer model)of an electronic component, circuit board, or system and applying virtual test signals to the model to verify its functionality and possibly its timing.

Often used for legend print and means the printed reference designators on a printed wiring boards.

An electrical impulse of a pre-determined voltage, current, polarity and pulse width.

A conductor layer intended to carry signals, rather than serve as a ground or other fixed voltage function.

An individual conductor used to transmit an impressed signal.

Short-circuit, An abnormal connection of relatively low resistance between two points of a circuit or conductors from different nets either touch or some closer than the minimum spacing allowed for the design rules being used.

A physical barrier, usually electrically conductive, designed to reduce the interaction of electric or magnetic fields upon devices, circuits or portions of circuits.

A condition occurring during etching in which the dielectric material, in intimate contact with the foil, is incompletely removed though acceptable etching may have been achieved elsewhere. In re-flow soldering, a condition in which component bodies block the infra-red energy from certain areas of the board. In wave soldering, the solder fails to wet some parts leads due to other devices blocking the flow of solder.

See Activating.

A technique involving the use of a solvent followed by hot-water rinses and drying.

A process for obtaining conductive patterns by a combination of electroless metal deposition with etching and/or electroplating. A semi-additive process is used in conjunction with a metal clad base material.

A network of metal or fabric standards mounted tautly on a frame and upon which the PCB’s circuit pattern is superimposed by photographic means.

A process for transferring an image to a surface by forcing suitable media through a stencil screen with a squeegee. Also called silk screening.

A drawing that shows, by means of graphic symbols, the electrical connections, components and functions of a specific electronic circuit arrangement.

An aqueous organic or inorganic base solution with additives that promote the removal of flux.