PCB Terminology

Some common definitions and widely used terms in the field of printed circuits.


B-Stage Resin : A thermosetting resin in an intermediate stage of the reaction in which the material swells when in contact with certain liquids and softens when heated, but may not entirely dissolve or fuse.

Base Material :
 Insulating material upon which the pattern may be formed.

Base Material Thickness  :
 The thickness of the base material excluding conductive foil or material deposited on the surfaces.

Bonding Sheet  :
 Sheet of prepreg or other material having suitable adhesive properties, used to bond together individual layers to produce a multilayer printed board.

Component Side : That side of the printed board on which most of the components will be mounted.

Conductive Pattern :
  Configuration formed by electrically conductive material of a printed board.

Conductor  :
Single conductive path in a conductive pattern.

Double-sided printed circuit board :
Printed board with conductive patterns on both sides.

Edge board contacts or Fingers :
Series of contacts printed on the edges of a printed board and intended for mating with an edge socket connector.

Flexi-rigid printed board :
 Printed board using a flexible base material and a combination of a flexible and rigid base materials in different areas.  Both the flexible and the rigid base materials bear conductive patterns which are normally interconnected in the combination area.

Flexible printed board  :
Printed board using a flexible bas material only.  It may be partially provided with electrically non-functional stiffeners and or coverlayers.

Flush conductor  :
Conductor of which the outer surface is in the same plane as the surface of the base material.

Legend :
A format of lettering or symbols on the printed board, e.g. part numbers, component locations, etc.

Mother Board :
A printed board on which one or more printed board assemblies may be assembled and connected.

Multilayer printed circuit board :
 Printed board consisting of alternate layers of conductive patterns and insulating materials with conductive patterns in more than two layers and with the conductive patterns interconnected as required.

Non-Conductive Pattern :
  Configuration formed by functional non-conductive material of a printed board (e.g. dielectric or resist).

Prepreg  Sheet :
Material (e.g. glass fabric) impregnated with a resin cured to a B-stage.

Printed Board Assembly :
Printed board with electrical and mechanical components and/or other printed boards attached to it with all manufacturing processes, soldering, coating, etc., completed.

Rigid Printed Board :
Printed board using a rigid base material only.

Single-sided printed circuit board  :
Printed board with a conductive pattern on one side only.

Solder Side  :
 The side of a printed board opposite to the component side.

Blind (semi-buried) Via : A via hole extending to one side of the printed board only.

Buried Vias : A vias hole not extending to either side of the printed board.

Component hole : Hole used for the attachment of component terminations to the printed board as well as for any electrical connection to the conductive pattern.

Conformal Coating : An electrically insulated coating on a printed board assembly to provide a protective barrier against deleterious effects from environment condition.

Coverlayer : A layer of insulating material covering totally or partially the surface of a printed board including the conductive pattern.

Cross-Hatching : Deliberate subdividing of large conductive areas.

Datum Reference : A defined point, line or plane used to locate patterns, holes or layers for manufacturing and or inspection purposes.

Interlayer connection : An electrical connection between conductive patterns in different layers of a multilayer printed board.

Landless hole :Plated-through hole without land.

Mounting hole : Hole used for the mechanical mounting of a printed board or for mechanical attachment of components to the printed board.

Plated-Through Hole : Through holes that is plated (PTH) in order for the components to make contact with the required conductive layers