PCB Glossary

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AOI AOI is used to inspect the inner or outer layers of a multi-layer PCB .
Annular Ring The annular ring is a round copper pad surrounding a drilling hole.
Array A single PCB arranged in rows and columns on a base material.
Artwork In PCB manufacturing the artwork is follow CAM data that is used to produce the artwork master.
Assembly Act or process of fitting together the parts of PCB
BGA Ball Grid Array
Bare Board An unpopulated printed circuit board.
Bare Copper The copper foil portion of a copper clad laminate for PCBs
Board Thickness The overall thickness of the base material.This would include the fiberglass, soldermask and silkscreen and the board finish.
Black Pad Black pad can happen on PCBs that have an Immersion Gold Finish .
Blind Vias Blind Vias are used in multi-layer boards where a drilled hole needs a connection from an outer layer to an inner layer
Buried Vias Buried Vias are used in multi-layer boards where a drilled hole needs a connection from an inner layer to an inner layer
Bow Bow references the flatness of a printed circuit board.
Burr A ridge left on the outside copper surface after drilling or routing.
CAD Computer Aided Design
CAM Computer Aided Manufacturing
CTE Coefficient of thermal expansion.
CTI Comparative Tracking Index.It is used to measure the electrical breakdown properties of the insulating material used in PCBs
CNC Computer Numerical Control.It is used in the PCB manufacturing process with CNC Drill Machines or Rout machines.
Copper Weight The Copper Weight is the total thickness of copper on the surface of a PCB.It is measured in oz/sq ft.For example 1OZ = 1.4mil
Counterbore The counterbore is cylindrical flat-bottom hole that enlarges another drilled hole.
Component Side The side of the circuit board on which most of the components are mounted.
DRC Design Rule Check
DIP Dual In-line Package
Date Code The date code shows the week and year that PCB was made.For example WWYY or YYWW
Double Sided PCB It has copper on the top and bottom of the board material, and includes connections through plated holes.
DFSM Dry Film Solder Mask.It is applied to the printed circuit board via a lamination process to protect the board from solder or plating.
Deburring Removing burrs after PCB drilling or routing
EPOXY A family of thermosetting resins used in the packaging of semiconductor devices.
Etching After an image pattern as been applied to a panel of copper clad fiberglass the unwanted copper is chemically etched away.
Electrical test It is the process of testing the board for opens and shorts.
Electroless Nickel Immersion Gold The nickel is plated onto the copper prior to the application of Gold and acts as a barrier to prevent the Gold and the Copper from migrating into one another.
Excellon Drill File NC drill file.It is defines the drill hole sizes, X & Y coordinates, and tool numbers for a circuit board.
FR-1 A paper material with a phenolic resin binder and the TG is about 130°C.
FR-2 A paper material with phenolic resin binder similar to FR-1 and the TG is about 105°C.
FR-4 Flame Retardant laminate made from woven glass fiber material impregnated with epoxy resin.
Fiducial Mark The fiducial is a circle that is a copper pad with the same finish as the rest of the board and provides alignment targets for automated assembly equipment.
Flash Gold Flash gold is hard gold with a maximum thickness of 3 micro inches.
Flexible Printed Board A printed board using a flexible base material only. May be partially provided with electrically non- functional stiffeners and/or coverlayer.
Flying Probe It uses several arms with probes on the end that work together to touch the test points on the PCB to determine if there are any opens or shorts on the board.
TG The temperature at which the circuit board material changes from being in a hard and relatively stable condition to being in a viscous or rubbery condition.
Gerber File Data file used to control a photo-plotter. A type of data that consists of aperture selection and operation commands and dimensions in X- and Y- coordinates.
Gold Fingers It is gold plated connectors on an edge of the PCB. Also see Finger.
Ground A common reference point for electrical circuits returns, shielding or heat sinking.
HASL Hot Air Solder Leveling. A method of coating exposed copper with solder by inserting a panel into a bath of molten solder then passing the panel rapidly past jets of hot air.
HDI Ultra fine-geometry multi layer PCB constructed with conductive surface Microvia connections between layers. These boards also usually include buried and/or blind vias are made by sequential lamination.
Hard Gold It is plated over a nickel finish and may also be referred to as Deep Gold.
Hole Density The number of holes per unit area on a PCB. For example 80000/M²
Hole Filling A process of adding a conductive or non-conductive fill material to a plated through hole.
Hole Plugging A process of plugging the VIA hole with liquid solder mask material after the circuit configuration has been completed.
IPC The Institute for Interconnecting and Packaging Electronic Circuits.
Immersion Silver The purpose of this silver plating is to protect the copper from corroding as well maintaining its solderability.
Immersion Tin The purpose of this tin plating is to protect the copper from corroding as well maintaining its solderability.
Immersion Gold The nickel is plated onto the copper prior to the application of Gold and acts as a barrier to prevent the Gold and the Copper from migrating into one another.
Impedance Electrical impedance is the measure of the resistance that a circuit presents to the passage of a current when a voltage is applied in an alternating current circuit.
Jump Scoring It is a process that is used when a printed circuit board is pannelized. It allows for a score line to jump over most of the panel border, leaving the border largely intact, and as a result, stronger and more rigid, resulting in a stiffer and stronger assembly panel..
LPI Liquid Photo Imageable Solder Mask
Lead Free HASL Contains a mix of 99.3% Tin and 0.6% Copper. It may be referred to as SN100CL
Laminate The process manufacturing a laminate using pressure and heat.
Laser Photo Plotter A plotter that uses a laser, which is able to produce very fine lines and dots to create a more accurate photo plot
Land The portion of the conductive pattern on printed circuits designated for the mounting or attachment of components. Also called Pad
Line A thin conductive area on a PCB surface or internal layer usually composed of lands and traces. Also known as a "conductor".
Local Fiducial A fiducial mark used to locate the position of a land pattern for an individual component on a printed board. (See "Fiducial Mark")
Multilayer PCB A Multi Layer PCB is a PCB that has more than two layers
Mil One thousandth of an inch. 1"=1000u"
Metal Foil Metal foil also called copper foil.It is used for the conductive layers of the PCB.
Microsectioning The quality of PCB, the occurrence and solution of the problem, the evaluation of the process improvement, in need of microsection as an objective examination
Mounting Hole Mounting Hole also called NPTH hole.It is used to secure the printed circuit board to its final assembly.
Minimum Annular Ring Lead wire extending from a component or module body along its longitudinal axis.
NPTH Non Plated Trough Hole.
NC Drill Aslo called NC drill file.It defines the drill hole sizes, X & Y coordinates, and tool numbers for a printed circuit board.
Netlist In electronic design, a netlist is a description of the connectivity of an electronic circuit.
Non Functional Pad A pad that is not connected electrically to the conductive pattern on its layer.
Open Circuit An open circuit is a break in the continuity of any given circuit on the board.
OSP Organic Surface Protectant is a type of surface treatment.It is applied to the copper.
Outer Layer The top and bottom sides of any type of printed circuit board.
Printed Circuit Board Also called Printed Wiring Board.
Plated Hole Also called PTH.It is a drilled hole on a PCB panel that has completed a plating process to allow a copper connection with pads connected to the hole.
Prepreg A sheet of material that has been impregnated with a resin cured to an intermediate stage.
Plating The chemical or electrochemical deposited metal on a surface..
Probe Test It used to make electrical contact between test equipment and the unit under test.
Routing Routing is the process of using a programmed rout machine to cut a PCB out of the manufacturing panel
RF(Radio Frequency) Represents the electromagnetic frequency that radiates into space, ranging from 300KHz to 30GHz
Rigid-Flex PCB A printed circuit board construction combining flexible circuits and rigid multi layers
SMT Surface Mount Technology.
Solder Paste Finely divided particles of solder, with additives to promote wetting and to control viscosity,drying rate, etc, that are suspended in a cream flux.
Solder Mask(Solder Resist) Coating to prevent solder to deposit on.
Solder Side The bottom side of the PCB.
Soft Gold It is also called wire bondable gold.
Stencil A sheet of material that has been perforated with a pattern ; ink or paint can pass through the perforations to create the printed pattern on the surface below.
Tg The Glass Transition Temperature.
Tooling Hole It is used to aid in alignment and orientation when assembling the PCB.
Tolerances a variety of tolerances in the PCB manufacturing process.
Test Point It is used for electrical testing purposes.
Testing According to the original assembly, the open and short circuit of the board is verified.
TG The Tg (Glass Transition Temperature) is one of the most important properties of any epoxy and is the temperature region where the polymer transitions from a hard, glassy material to a soft, rubbery material.
Track Segment of a conductor route or net.
V-Score Also called V-CUT or V-Groove. It is a small grove that is cut into an array of PCBs so that after components are added they can easily be separated.
VIA A plated-through hole in a PWB that is only used as an interlayer connection and no intention to insert a component lead.
Wire Bondable Gold See "Soft Gold"
X-Outs An X-Out occurs when on an array of PCBs a single board fails electrical test or final inspection.
X-Rays X-rays are part of the electromagnetic spectrum.It is used in multilayer board process.