| Activating - A treatment that alters non-conductive material responsive to electroless plating. |
| Additive Process - Selective deposition or addition of conductive material onto clad or unclad base material. |
| Analog Circuit - An electrical circuit with a constant variable signal |
| Annular Ring - The area of conductive material encircling a hole. |
| Array - A set of elements or circuits arranged into rows and columns on a base material. |
| Artwork - A scaled configuration used in the production of the artwork master or production master. |
| Artwork Master - The photographic film or glass plate which represents the image of the PCB pattern. |
| Aspect Ratio - The ratio of the board thickness to the smallest hole diameter on the printed circuit. |
| Assembly - A number of parts, subassemblies, or any combination thereof joined together. |
| Assembly File - An image that describes the placement of components on the circuit board. |
| Assembly House - A facility which provides the service of soldering and attaching components to printed circuit board. |
| Automated Test Equipment (ATE) - Automated equipment designed for the analysis and testing of functional parameters to evaluate performance of tested electronic devices. |
| B-Stage - Intermediate stage in the thermosetting resin reaction where the heated material softens and expands when in contact with certain liquids. |
| B-Stage Resin - A thermosetting resin at an intermediate state of the curing process. |
| Bare Board - A circuit board that has not been assembled. |
| Barrel - The cylinder created when plating through a drilled hole. |
| Base Copper - The thin, copper foil area of a copper-clad laminate which can be present on one or both sides of the board. |
| Base Material - The insulating material where a conductive outline is formed. |
| Base Material Thickness - Measured thickness of the base material not including metal foil or any material deposited on the surface. |
| Bed of Nails Fixture - A test fixture that consists of a frame and a holder containing a field of spring-loaded pins that make electrical contact with a planar test object. |
| Bleeding - When a plated hole releases process materials of solutions from crevices and voids. |
| Blind Via - A conductive surface hole that connects an outer layer with an inner layer of a multi layer circuit board. |
| Blister - A localized separation caused by swelling of any of the layers of a laminated base material, or between the base material and conductive foil. |
| Board House - A manufacturer or source of printed circuit boards. |
| Board Thickness - The total thickness of the base material along with metal foil and any material deposited on the surface. |
| Bond Strength - Force per unit area needed to separate two adjacent layers of a board by a force that is perpendicular to the surface. |
| Book - The number of prepeg plies assembled with the inner layer cores for curing in a lamination press. |
| Bow - The unevenness of a board characterized by a generally cylindrical or spherical curvature. |
| Built In Self Test - The means by which a machine tests itself. |
| Buried Via - A via hole of a multi layer circuit board that does not extend all the way to the surface of a printed board. |
| Burr - A ridge enclosing the outside copper surface after drilling. |
| CAD - Abbreviation for Computer Aided Design. |
| CAM - Abbreviation for Computer Aided Manufacturing. |
| Catalyst - A substance that is used to increased the speed of reaction between the resin and curing agent without itself being consumed. |
| C-Stage - A resin polymer in its solid and final state of cure. |
| Capacitance - A measure of the electrical energy that is stored between conductive materials of different potentials. |
| Center to Center Spacing - The distance between the centers of adjacent components. |
| Chamfer - A broken sharp edged corner. |
| Chip on Board (COB) - The direct attachment of a chip to a circuit board by solder or other adhesives. |
| Circuitry Layer - The layer on a circuit board containing conductors, including ground and voltage planes. |
| Clad - A copper object located on a printed circuit board. |
| Clearance Hole - A hole in the conductive pattern larger and coaxial with a hole in the base material of a PCB. |
| Coating - a layer of material deposited on the surface. |
| Coefficient of Thermal Expansion (CTE) - A ratio of material changes in any axis per degree to temperature change. |
| Component Hole - A hole used to attach and electrically connect component terminations(including pins or wire) to the printed circuit board. |
| Component Side - The side of the printed circuit board where most of the components are found. |
| Computer Numeric Control (CNC) - An automated system by which a computer serves as the primary control in carrying out machine operations. |
| Conductor - The thin, conductive area on the surface or internal layer of a circuit board usually composed of lands and paths. |
| Conductor Spacing - The separation between adjacent edges of isolated conductive patterns on a conductor layer. |
| Conductor Thickness - The thickness of the conductor including any metallic coating. |
| Conformal Coating - An insulating, protective coating that matches the configuration of the coated object and is present on the assembled board. |
| Connector Area - The area of the circuit board used to provide electrical connections. |
| Controlled Impedance - Control of substrate material properties with trace dimensions and positions to implement specific electric impedance. |
| Copper Foil - The layer of copper coating on a circuit board. |
| Core Thickness - Thickness of only the laminate base. |
| Corrosive Flux - A corrosive discharge that contains reactive materials that can cause damage by oxidation. |
| Crosshatching - The condition of breaking up a conductive area through voids in the conductive material. |
| Curing - Polymerization of a thermosetting epoxy to produce a bond. |
| Curing Time - The amount of time necessary for an epoxy to cure. |
| Date Code - Items marked with their date of manufacturing. |
| Deburring - The process of removing burrs after drilling. |
| Delamination - A separation of plies within the base laminate material or any separation between planes of a printed circuit board. |
| Design Rule - The rules for a circuit design in accordance to specified design parameters. |
| Design Rule Checking - A procedure in which a computer program is used to carry out continuity verification of conductor routing in compliance with the designated design rules. |
| Desmear - The removal of melted resin from friction and drilling debris from the walls of a hole. |
| Dielectric - An insulating medium between two conductors. |
| Digitizing - The conversion of feature locations on a flat plane to a digital representation in X-Y coordinates. |
| Dimensional Stability - The dimensional change of a material caused by factors such as changes in temperature, humidity, chemical treatments, and the level of exposure to various stresses. |
| Double-Sided Assembly - An assembled printed circuit board with components on both sides. |
| Double-Sided Board - A printed circuit board that has conductive patterns on both sides. |
| Dry-Film Resists - A coating which is resistant to various electroplating and etching processes. |
| Dry-Film Solder Mask - A coating material that is applied to the printed circuit board via a lamination process to protect the board from solder or plating. |
| Dual In-Line Package (DIP) - A kind of housing used for integrated circuits. |
| Edge Clearance - The shortest distance between any conductor or component to the edge of the circuit board. |
| Edge Connector - A connector on the edge of the circuit board used to connect it to another electronic device. |
| Electroless Copper - A thin layer of copper deposited on surface of a printed circuit board from an autocatalytic plating solution. |
| Electrical Continuity - The continuous flow of the electrical current. |
| Electroless Deposition - The chemical deposition of a conductive material. |
| Electroplating - The electrical deposition of an adherent metal coating on a conductive object. |
| Epoxy - Thermosetting resins that form a chemical bond to several metal surfaces. |
| Epoxy Smear - Epoxy resin that has been deposited on copper edges in holes during the drilling process. |
| Etchback - The regulated removal of all constituents of the base material by a chemical process that acts on the sidewalls of plated-through holes (PTH) to expose internal conductor areas. |
| Etching - The removal of selected portions of conductive materials. |
| Imaging - The transferring of data to a photoplotter wherein a negative image of the circuitry pattern is transferred onto the panel or film using light. |
| Immersion Plating - Chemical deposition of a metallic coat over certain basis metals through the partial displacement of the basis metal. |
| Impedancev - A material's opposition to the flow of an electrical current. |
| In-Circuit Test - A test of an individual component or only a part of the circuit as opposed to testing the entire circuit. |
| Inner Layers - The internal layers of a multi layer circuit board. |
| Insulation Resistance - The electrical resistance of current flow the insulating material between contacts. |
| Interconnect Stress Test (IST) - A system that measures the ability of the total interconnect to endure the thermal and mechanical strains from the manufactured state to the point at which the product reaches interconnect failure. |
| Interstitial Via Hole - A through hole which is embedded with connection of two or more layers in a multi layer circuit board. |
| Laminate - Plastic material usually reinforced by glass or paper that supports the copper cladding from which the circuit traces are created. |
| Laminate Thickness - The thickness of the metal-clad base material prior to processing. |
| Laminate Void - The lack of epoxy resin in a cross-sectional area in which epoxy resin would normally be present. |
| Land - The area of the conductive pattern on printed circuit boards designated for the mounting of components. Also referred to as pad. |
| Lead - A terminal of a component. |
| Leakage Current - The small amount of current that flows over a dielectric area between two adjacent conductors. |
| Legend - A format of lettering or symbols on the printed circuit board that may describe part or product numbers, serial numbers, logos, component locations and patterns. |
| Line - A thin conductive area on a circuit board surface or internal layer usually composed of lands and paths. Also known as a conductor. |
| Liquid Photo-Imageable Solder Mask (LPI) - A specially developed ink used in photographic imaging to control thinner mask deposition. |
| Mask - An applied material that enables selective etching, plating, or the application of solder to a printed circuit board. |
| Measling - White spots or crosses underneath the surface of the base laminate that indicate a separation of fibers in the glass cloth at the weave intersection. |
| Metal Foil - The layer of conductive material where circuits are formed. |
| Micro-Sectioning - The preparation of a specimen of a selected material to be used in metallographic examination. |
| Microvia - Usually defined as a conductive hole with a diameter of 0.006 inches or less that connects layers of a multilayer printed circuit board. |
| Mil - A unit of measurement that represents on thousandths of an inch. |
| Minimum Conductor Width - The minimal width of any conductor on a printed circuit board. |
| Minimum Conductor Space - The shortest distance between any two conductors. |
| Multilayer Printed Boards - Printed circuit boards consisting of at least three layers separated by laminate layers and bonded together with internal and external connections to each level of the circuitry. |
| Pad - The area of the conductive pattern on printed circuits designated for the mounting of components. Also known as land. |
| Panel - A sheet of base material or metal-clad material that is used in the processing of printed circuits. |
| Pattern - The specific configuration of conductive and nonconductive materials on a panel or PCB. |
| Pattern Plating - The selective plating of a conductive pattern. |
| PEC - Printed Electronic Component |
| Photo Print - The process of creating a circuit pattern image by passing light through a photographic film which hardens a polymerizing material. |
| Photographic Image - An image in a photo mask that is on a film or plate. |
| Photoplotting - A photographic process that creates an image by passing light that directly exposes a light-sensitive material. |
| Photo Resist - A type of material that is sensitive to only portions of the light spectrum and is used to mask portions of the base metal. |
| Pin - A terminal on a component. |
| Pitch - The distance between the center of any two adjacent conductors. |
| Plated Through Hole (PTH) - A hole with that has been plated on its walls which creates an electrical connection between conductive layers or external layers. |
| Plating Resist - A material deposited on an area to selectively prevent plating. |
| Plating Void - An absence of a specific metal from an area. |
| Plotting - The mechanical conversion of x,y positional information into a visual representation. |
| Prepreg - Sheet material impregnated with a resin cured to an intermediate stage. |
| Printed Circuit Board (PCB) - A board of insulating material that is used to provide support and electrical connections for electronic components. |
| Printed Wiring Board (PWB) - See printed circuit board. |
| Prototye - A sample printed circuit board used to test out a design. |
| Pulse Plating - Usage of pulses in plating instead of a direct current. |
| Reflowing - The melting of electrodeposit proceded by solidification. |
| Registration - The level of conformity of a pattern to its intended positions. |
| Resin (Epoxy) Smear - Resin that has been transferred from the base material onto the surface of the conductive pattern in the wall of a drilled hole. |
| Resist - Coating material used to protect selected areas of a pattern from an etchant, solder or from plating. |
| Rigid-Flex - A type of circuit board combining both flexible and rigid dielectric materials in an assembly. |
| RoHS - Restriction on Use of Hazardous Substances. |
| Routing - The process in which electrical connections are made between lands. |
| Screen Printing - A process that transfers an image to a surface by forcing the appropriate media through a stencil screen with a squeegee. |
| Silk Screen - The layer defined by text and graphics on a printed circuit board. |
| Single-Sided Board - A printed circuit board with conductive pattern on a single side. |
| Small Outline Integrated Circuit (SOIC) - a type of integrated circuit that has two parallel rows of pins in surface mount package. |
| SMD - Surface Mount Device. |
| SMOBC - Solder mask over bare copper. |
| Solder - An alloy that is used to bond or seal metals with higher melting points. Particularly useful due to its low melting point. |
| Solder Bridging - Solder that connects two or more lands that come into contact to form a conductive path. |
| Solder Coat - A layer of solder applied from a solder bath onto a conductive pattern. |
| Solder Leveling - A method in which excess solder is removed by hot air or hot oil. |
| Solder Mask - a protective coating for the traces on a printed circuit during the soldering process. |
| Surface Mount Technology (SMT) - The soldering of components to the board without the use of holes. |
| Statistical Process Control (SPC) - The collection of process data and creation of control charting used to monitor stability. |
| Step-And-Repeat - A method by which successive exposures of a single image are made to create a multiple image production master. |
| Substrate - a laminate insulator used to separate the circuitry on a printed circuit board. |
| Tented Via - A type of via with dry film solder mask covering its pads and plated-through holes. |
| Tenting - Covering the holes of a PCB and the neighboring conductive patterns using a dry film resist. |
| Terminal - A connection point for two or more conductors in a circuit. |
| Test Coupon - A portion of a printed circuit board or panel containing printed coupons used to test the acceptability of the board. |
| Test Fixture - The term for the interface that connects the testing equipment and the item being tested. |
| Test Point - A designated point used to test the acceptability or quality of a circuit board. |
| TG - The point at which the temperature has caused the resin inside the base laminated to soften into a plastic like substance. |
| Tooling - The process and associated costs of setting up a printed circuit board for manufacturing. |
| Tooling Holes - The general term for holes placed on a circuit board or a panel for registration and hold down purposes during the manufacturing process. |
| Top Side - The side of the circuit board where components are located. |
| Trace - The conductive lines that allow for the flow of a current between electronic components. |
| Traveler - A list containing instructions describing the board, which may include specific processing requirements. |
| Twist - A laminate defect in which the divergence from planarity creates a twisted arc. |
