Glossary of Printed Circuit Board Terms    

A

• Air Gap
• Analog Circuit
• Annular Ring
• Artwork - Taped
• Artwork - CAD
• AWG
• Axial Leads

B

• Bridging
• Bus
• Bypass Capacitor

C

• Conformal Coating
• Connector Tongue

D

• Digital Circuit
• Discrete Component

F

• Feed-Thru (VIA)
• Flow Soldering

G

• Glass Epoxy
• Grid
• Ground Plane

M

• Master Pattern
• Mother Board

P

• Plating

R

• Radial Lead
• Registration

T

• Tooling Hole

Air Gap: The nonconductive air space between traces, pads, conductive matter, or any  combination thereof.

Analog Circuit: A circuit comprised mostly of discrete components  (resistors, capacitors, transistors) which produces data represented by physical variables such as voltage, resistance... etc.

Annular Ring: The width of the conductor surrounding a hole through a Printed Circuit Pad.

Artwork - Taped: An accurately scaled configuration used to produce a Master Pattern. Generally  prepared at an enlarged scale using various width tapes and special shapes to represent  conductors.

Artwork - CAD: Computer generated accuracy in layout used to produce a Master Pattern.  Generally  prepared at 1:1 scale using various software packages with special libraries of shapes to represent  conductors and components and various Surface Mount Arrays.

AWG: American Wire Gage. A method of specifying wire diameter. The higher the number,  the smaller the diameter.

Axial Leads: Leads coming out of the ends and along the axis of a resistor, capacitor, or  other axial part, rather than out the side.

Bridging: A condition that generally happens during the wave soldering operation where  excess solder builds up and shorts out the adjacent conductors.

Bus: A Heavy trace or conductive metal strip on the Printed Circuit Board used to distribute voltage, grounds, etc., to smaller branch traces.

Bypass Capacitor: A capacitor used for providing a comparatively low impedance AC path around a circuit element.

Conformal Coat: A coating that is generally sprayed, dipped, or brushed on to provide the completed Printed Circuit Board protection from fungus, moisture and debris.

Connector Tongue: A protrusion of the Printed Circuit Board edge that is manufactured to a  configuration to mate with a receptacle that provides electrical and/or mechanical junction between  the Printed Circuit Board and other circuitry.

Digital Circuit: A circuit comprised of mostly integrated circuits which operates like a switch (i.e.,it is either "ON" or "OFF").

Discrete Component: A component which has been fabricated prior to its installation (i.e., resistors, capacitors, diodes and transistors).

Feed-Thru (VIA): A plated through hole in a Printed Circuit Board that is used to provide electrical connection  between a trace on one side of the Printed Circuit Board to a trace on the other side. Since it is not  used to mount component leads, it is generally a small hole and pad diameter.

Flow Soldering: Also called wave soldering. A method of soldering Printed Circuit Boards by moving  them over a flowing wave of molten solder in a solder bath.

Glass Epoxy: A material used to fabricate Printed Circuit Boards. The base material (fiberglass) is  impregnated with epoxy filler which then must have copper laminated to its outer surface to form  the material required to manufacture Printed Circuit Boards.

Grid: A two-dimensional network consisting of a set of equally spaced parallel lines superimposed upon  another set of equally spaced parallel lines so that the lines of one set are perpendicular to the lines of the other.

Ground Plane: A condition where all unused areas (areas not consumed by traces or pads) of the Printed Circuit Board are left unetched and tied to the ground circuit throughout the board.

Master Pattern: An accurately scaled pattern which is used to produce the Printed Circuit within the accuracy specified in the Master Drawing.

Mother Board: Also called the Back Plane, or Matrix Board. A relatively large Printed Circuit Board  on which modules, connectors, subassemblies or other Printed Circuit Boards are mounted and  interconnections made by means of traces on the board.

Plating: A uniform coating of conductive material upon the base metal of the Printed Circuit Board.

Radial Lead: A lead extending out the side of a component, rather than from the end.

Registration: The alignment of a pad on one side of the Printed Circuit Board (or layers of a multilayer board) to its mating pad on the opposite side.

Tooling Hole: Also called Fabrication Hole, Pilot Hole, or Manufacturing Hole.