Aspect Ration |
The The ratio of the circuit board thickness to the smallest drilled hole diameter |
Base Copper: |
Copper foil provided in sheet form or clad to one or both sides of piece of laminate used as either internal or external layers of a circuit board. |
Base Laminate |
The dielectric material upon which the conductive pattern may be formed. The base material may be rigid or flexible. |
Base Material |
See Base Laminate. |
Bond Strength |
The force in sq inches required to delaminate two adjacent layers of a board when attempting to separate the layers. See Peel Strength. |
Bow |
the measurement of flatness of a circuit board, between corners and the center. |
Breakdown Voltage |
The voltage at which an insulator or dielectric ruptures, or at which ionization and conduction take place in a gas or vapor. |
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Comparative Tracking Index |
CAD |
Computer Aided Design. A software which allows engineers create and design a printed circuit layout. |
CEM |
Composite Epoxy Material |
Conductive Pattern |
The configuration or design of the conductive material on the base laminate through which electrical energy passes. Includes conductors, lands, and through connections. |
Conductor |
A copper area on a PCB surface or internal layer usually composed of lands (to which component leads are connected) and paths (traces). |
Conductor Base Width |
The conductor width at the plane of the surface of the base material. See Conductor Width. |
Conductor Thickness |
The thickness of the trace or land including all metallic coatings. |
Conductor Width |
The observable width of the pertinent conductor on the printed circuit board. |
Conductor-to-Hole Spacing |
The distance between the edge of a conductor and the edge of hole. |
Copper Foil |
See Base Copper and Clad or Cladding. |
CTE |
Coefficient of thermal expansion expressed as ether ppm or a percentage. |
CTI |
A separation between any of the layers of a base material or between the laminate and the conductive foil, or both. |
Design rule check |
The use of a computer program to perform continuity verification of all conductor routing in accordance with appropriate design rules. |
Dielectric |
An insulating medium, which occupies the region between two or more conductors. |
Dielectric Constant |
The ratio of permittivity of the material to that of a vacuum (referred to as relative permittivity). |
Double-Sided Board |
A circuit board with conductive patterns on both sides. |
ENIPIG |
Electroless Nickel Electroless Palladium Immersion Gold |
Etch Factor |
The ratio of the depth of etch (conductor thickness) to the amount of lateral etch (undercut). |
Fab |
Short for fabrication. |
Fabrication drawing |
A drawing used to aid the construction of a printed board. It shows all of the locations of the holes to be drilled, their sizes and tolerances, dimensions of the board edges, and notes on the materials and methods to be used. Called "fab drawing" for short. |
Fiducial |
Etched features or drilled hole used for optical alignment during assembly operations. |
Film Artwork |
A positive or negative piece of film containing a circuit, solder mask, or nomenclature pattern. |
FR-4 |
A grade of Flame-Retardent industrial laminate having a substrate of woven-glass fabric and resin binder of epoxy. FR-4is the most common dielectric material used in the construction of PCBs in the USA. Â Its dielectric constant is from 4.4 to 5.2 at below-microwave frequencies. As frequency climbs over 1 GHz, the dielectric constant of FR-4 gradually drops. Tg 150 to 175 c. |
Gerber file |
Data file used to control a photo plotter. Named after Gerber Scientific Co., who made the original vector photo plotter. |
Glass Transition Temperature |
Tg The temperature at which an amorphous polymer (or the amorphous regions in a partially crystalline polymer) changes from a hard and relatively brittle condition to a viscous or rubbery condition. When this transition occurs, many physical properties undergo significant changes. Some of those properties are hardness, brittleness, coefficient of thermal expansion, and specific heat. |
Hole Void |
A void in the metallic deposit of a plated-through hole exposing the base material. |
Hot Air Solder Leveling |
(HASL) a method of coating exposed copper with solder by inserting a panel into a bath of molten solder then passing the panel rapidly past a series of hot air jets. |
Ink |
Common term for screen resist. |
Inner layer |
Any layer that will be pressed on the inside of a multilayer board. |
Insulation Resistance |
The electrical resistance of the insulating material as measured between any pair of contacts or conductors. |
IPC |
The Institute for Interconnecting and Packaging Electronic Circuits. |
Laminate |
A product made by bonding together two or more layers of material. |
Laminate Thickness |
Thickness of the base material, not including metal-clad, prior to any processing. Applies to single- or double-sided material. |
Laminating Presses: |
Multilayer Equipment that applies both pressure and heat to laminate and pre-preg to make multilayer boards. |
Lamination |
The process of pressing a laminate |
LPI |
Liquid Photo Imageable. Refers to liquid photo imagable solder mask. |
MHE |
Micro Heat Exchanger |
MCPCB |
Metal Core Printed Circuit Boards |
MOT |
Maximum Operating Temperature |
Netlist |
List of names of symbols or parts and their connection points which are logically connected in each net of a circuit. A netlist can be "captured" (extracted electronically on a computer) from a properly prepared CAE schematic. |
Nomenclature |
Identification symbols applied to the board by means of screen printing ink jetting see legend. |
Pad |
The portion of the conductive pattern on printed circuits designated for the mounting or attachment of components. Also called Land. |
Panel |
The square or rectangular base material containing one or more circuit patterns that passes successively through the production sequence and from which printed circuit boards are extracted. See Back Planes and Panels .typically 12" by 18" or 18" by 24". |
Panel Plating |
The electrolytic plating of the entire surface of a panel (including holes). |
Pattern |
The configuration of conductive and nonconductive materials on a panel or printed board. Also the circuit configuration on related tools, drawings, and masters. |
Pattern Plating |
Selective electrolytic plating of a conductive pattern. |
Printed Circuit Board |
(PCB) The general term for a printed or etched circuit board. It includes single, double, or multiple layer boards, both rigid and flexible. |
Printed Wiring Board |
A part manufactured from rigid base material upon which completely processed printed wiring has been formed |
QTA |
Quick Turnaround |
Solder Mask |
A coating applied to a circuit board to prevent solder from flowing onto any areas where it`s not desired or from bridging across closely spaced conductors. |
Solder Masking Coating |
Term for resist. |
Solder Resists |
Coatings that mask and insulate portions of a circuit pattern where solder is not desired. |
Solderability Testing |
The evaluation of a metal to determine its ability to be wetted by solder. |
Surface mount technology |
SMT defines the entire body of the process and components that create printed circuit board assembly with leadless components. |
Underwriters Laboratory |
Certifying agency for consumer electronics. See also Underwriters Symbol. |
Underwriters Symbol |
A logotype denoting that the product has been recognized by Underwriters Laboratory, Inc. (UL). |
UL |
Underwriter Laboratories Inc |