Here is a selection of key words and technical terminology used in circuit board technology. This list will be maintained and extended.

Term (translation)  Explanation  
µBGA (micro ball grid array)  BGA with pitch < 1 mm  
µVia (microvia)  Small blind via  
A stage  Description for the degree of setting of resin systems e.g. in prepreg  
ALIVH (Any Layer Internal Via Hole)  electrical connection between layers via conductive pastes  
AOI (Automat. Opt. Inspection)  Test equipment for optical inspection  
ASIC (application specific integrated circuit)  Component that was designed for a specific application  
Etch  Chemically removing material e.g. using acid  
Bare board  Circuit board with no components fitted  
Base material (substrate, laminate)  Material of a circuit board  
Exposure  Step in the photoplotting process, where a photosensitive layer is activated.  
Silk screened component identification  White or yellow  
Assembly  Placing the components onto the printed circuit  
Assembled board  Printed circuit with components fitted  
BGA (ball grid array)  Active component with two-dimensional pattern of connections using solder balls  
Bending radius  Sharpest bend for flexible printed circuits  
Black pad  Fault visible on the surface of electroless nickel/gold  
Lead  Poisonous metal used in the alloy for conventional solder  
Lead-free  European guideline RoHS, WEEE (2002/95/EU and 2002/96/EU)  
Aperture tables  Definitions in Gerber files  
Blind via  Blind via  
Bottom  Underside of a circuit board, what used to be mostly the solder side  
Bump  Contact point on component  
Buried via  Completely internal through contact  
CAD  Computer Aided Design  
Conductive carbon varnish  Varnish containing graphite as a touch electrical contact  
CEM1  Cost effective base material  
CEM3  Cost effective base material  
Circuit board  Board with a conductive circuit printed on it  
COB  (Chip On Board) Wire bond technology  
DGA  (Die Grid Array) Component with a pattern of bumps directly on the chip  
Thick copper (solid copper)  Option for tracks, to dissipate the heat resulting from high currents and losses  
TPH  (Through Plated Holed) hole with a metallised wall, copper sleeve  
Drill  Usually a CNC mechanism to make a round hole  
DSC  (Differential Scanning Calorimetry) a method to determine Tg  
Layout  Conversion of circuit diagrams to a set of track & hole patterns  
Cooling  Passive and active cooling as part of thermal management  
EP  (epoxide) The resin system used in most types of base materials  
Eurocard  100 mm x 160 mm as a standard size for circuit boards  
Extended Gerber  A format for printed circuit data  
FP  Flat Pack  
FBGA  Fine pitch BGA  
FC  (Flip Chip) a chip that is connected directly to a circuit board via bumps  
Flat Pack  Low profile electronic component  
FR  (Flame Retardant) i.e. self extinguishing  
FR1  Base material made of phenolic resin and hard paper  
FR2  Base material made of phenolic resin and hard paper  
FR3  Base material made of epoxy resin and hard paper  
FR4  Base material made of epoxy resin as a glass fibre composite  
FR5  High temperature FR4  
Printed circuit  Circuit board derived from a silk-screen print of an etch-resist varnish. Hence "printed circuit"  
Printed resistor  Carbon print to produce resistors, amongst other things  
Glass fabric  Reinforcing mats for resin-based circuit board systems  
HAL  (Hot Air Levelling) Producing finish by immersion in liquid tin  
HDI  High Density Interconnection, mostly using microvias  
Heatsink  Thick sheet copper or aluminium glued to a circuit board to dissipate heat  
HMD  Hole Mounted Device i.e. component with leads that go through the board  
Controlled impedance  Calculation, manufacture and test of impedance using defined geometries and materials  
Inlay technology  Copper inlay in circuit boards for high thermal transport  
Integrated inductance  Coil produced by layout on internal layers of multilayer boards  
Integrated capacitance  Deliberate use of internal layers of multilayer boards as capacitors  
Junction  An interface within semiconductors, specifies the location of the source of heat for power components  
Laminate  Laminate a layer e.g. to laminate copper on a base material or to laminate covering/protective films  
Surface leakage current  Current flowing through surface resistance  
Copper lamination  Metallic, copper sheet attached to base material  
Laminate (press)  Sticking layers together, using pressure and sometimes heat  
Laser cutting  A CNC mechanism to cut using a laser beam  
LDI  Laser Direct Imaging for photoresists, resist layers, solder resist  
Track spacing  The spacing between adjacent tracks, measured at the base of the conductor  
Track width  The width of conductors, measured at the base of the track  
Hole master  A drill template as a mechanical template for mechanical processing by drilling  
Solder covering varnish  Temporary, elastic, pull-off protective layer  
Solder deposit  Pads with solder deposit, usually deposited electrolytically  
Solder lacquer  Flux (which dries) from a spray can, on a rosin basis  
Solder resist  Circuit board coating to protect from corrosion and solder flow  
MCB  Multi Chip Board - i.e. a circuit board with many chips  
Multilayer  A circuit board built up from multiple layers  
NTPH  Not through-plated hole  
Net list  List of the connections between the components to permit the circuit board to be electrically tested  
Package  Encapsulation of chips and MCMs to produce components suitable for assembly.  
Pad  Contact surface on the circuit board, solder eye or SMD connection  
Panel  Circuit board blank in manufacturing format  
Pattern  The copper structure on circuit boards  
PCB   (Printed Circuit Board) board with a conductive circuit printed on it  
PEN  Polyethylene naphthalate, a solderable, cost effective plastic for simple, flexible circuits.  
PGA (pin grid array)  BGA with connecting legs, instead of balls/bumps  
PI  Polyimide, a temperature-stable, thermosetting plastic for high temperature applications  
Pitch  Spacing between pads  
Plug  Connector  
Via plug  To fill and maybe metallise vias  
Pool  When a manufacturing panel includes several layouts  
Prepreg  Resin impregnated glass fabric, where the resin has been semi-hardened.  
Reflow  Soldering process where solder paste is melted  
Resist  A covering pattern to resist chemical or physical processes, e.g. photoresist: a layer structured by a photolithographic process, which functions as an etch-resist or electrolysis resist. Metal resist: a "tin" layer made of copper as an etch resist when using alkali etchants  
Scoring  Milling a groove to create a defined breaking point  
Rogers  Supplier for HF material, LCP and PI-Flex  
SBU  Sequential Build-Up, building up multilayer boards, layer by layer  
Protective varnish  Protective coating for modules  
Semiflex, semiflexible printed circuits  Half flexible printed circuit e.g. made of thin FR4  
Countersinks  Cone-shaped extensions of holes, metallised or non-metallised  
SMD  Surface Mounted Device i.e. a component for SMT  
SMT  Surface Mount Technology, i.e. fitting components to the surface only of circuit boards  
Proof voltage  The ability of base material to insulate high voltages  
Rigid-flex  Rigid circuit boards which are connected via flexible printed circuits  
Connector gold  Electroplated hard gold coating for connector strips  
Teflon  Trade name for PTFE products from DuPont  
Tenting  Holes being covered by films such as solder resist and other resist films  
Downwards milling  Milling along the Z axis e.g. for cavities in semiflex/rigid-flex printed circuits  
Treatment  Roughening, processing of copper foil to improve adhesion  
TS bonding  Thermally supported ultrasonic bonding, gold wire bonds  
US bonding  Ultrasonic bonding using aluminium wire  
Loss factor  Measure for loss  
Twisting  Mis-shaping of a circuit board so that opposite edges are no longer parallel  
Warping  Two dimensional curvature of a circuit board  

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