To assist in understanding printed circuit boards, Avanti Circuits has put a list of some of the most commonly used terms in PCB manufacturing. For a more detailed glossary of PCB terms, visit Avanti Circuits’ PCB glossary.

Anti-Tarnish – A post-dip chemical process used to retard oxidation of copper circuits.

Backup Material – Hard flat material used to back-up laminate when drilling to reduce burrs.

Backplane – A very thick, large circuit board used to hold an array of pins for wire wrapping.

Blanking Die – Using a die punch to “blank out” the finished circuit board, used mostly for single-sided panels.

Blow Holes – Blow holes caused by an outburst of gas from solder fillet on a circuit board during the soldering operation.

C-Stage – Fully-cured dielectric laminate.

Caul Plates – Rigid, polished, flat, stable steel plates used when pressing or laminating MLBs

Clad – A condition of the base material to which a relatively thin layer or a sheet of metal foil has been bonded to one or both of its sides.

Conversion Coating – Anti-oxidant treatment applied to raw vendor foil.

DES – Develop, etch & strip process used in the etching stage of inner-layer fabrication.

Direct Plate – Application of conductive coatings on drilled holes to provide electrical continuity for electrolytic plating.

DOE – Design of experiments… a formal method of designing an interactive test matrix.

Dog Bone – A plating defect found in drilled holes where the electroplated copper is thin in the center and thicker at the knee.

Double Treat – Brass-based coating applied to copper foil as a substitute for oxide.

Entry Material – Thin metal foil (usually aluminum) attached to top side of drill stack to reduce drilling burrs and cool drill.

FPPY – First pass panel yield… number of good “panels” after subtracting defective panels.

Flux – A chemical activator use when reflowing solder or attaching components.

Haloing – Fracturing/delamination on or below the surface of the base material; it is usually exhibited by a light area around holes.

Hard Board – Rigid circuit board.

Liquid Resist – The liquid form of photoresist used in the fabrication of circuits.

Mil Spec – Specification set forth by the military.

Mil – Common term used to define thicknesses below 0.100 inches. (One mil = 0.001 inches).

Millionths – Term used when defining thickness. (100 millionths = 0.0001 inches.)

Mother Board – A printed circuit board used for interconnecting arrays of plug-in electronic modules.

Nail Heading – The flared condition of copper on the innerconnect layer of a multilayer caused by poor drilling.

One Ounce Foil – Weight of 1 square foot of copper foil. (1 oz = 0.00134 inches, ½ oz = 0.0007 inches, etc.)

OSHA – Occupational Safety & Health Agency.

OSP – Organic Surface Protection.

Oxide – A special treatment applied to copper surfaces of inner layers of a PWB to insure bond integrity.

Panel – Used to describe a common sheet size used in the fabrication process, ie: 24” X 18”.

Panel ft (Laminate ft) – A laminate area measurement, one-side only of the panel. (1 panel, 18” X 24” X 1 side = 3 panel ft).

Pattern-Plate – Electroplating of circuits using photoresist as a mask to protect the background, usually copper & tin.

Photoresist – An organic emulsion containing photoactive compounds, which will crosslink when exposed to UV light.

Pin Holes – Small defects etched through a circuit pattern.

Pink Ring – A defect caused by poor bonding around drilled holes displayed by acid attack of the oxide.

Pitch (density) – A method of defining circuit lines and spaces i.e.; 4 & 4, 4 mil lines and 4 mil spaces.

Plasma – Creation of corona in a chamber by exciting certain gasses in a partial vacuum with an electrical field, used to desmear.

Power Plane – Heavy circuit features designed to carry high electrical loads in a PWB.

Print – Expose step to define circuit patterns in photo resist.

Print & Etch – Simple fabrication method using photoresist to define etch pattern.

Pumice Scrub – A mechanical cleaning step using brushes and an abrasive media.

Punching – Using dies to punch component holes, usually in single & double-sided PWBs.

Signal Layer – Fine circuits designed to carry high speed signals throughout a circuit board and its components.

Skip Plate – Area of absent metal in plating.

Solder Plate – Tin/lead alloy plated in a pattern to define the finished features or circuits.

SPC – Statistical Process Control.

Surface ft – Total surface square feet area of a given work piece. (1 panel 18” X 24” X 2 sides = 6 surface ft).

Tab Plate – Selective plating on edge connectors, usually nickel/gold.

Tabs – A portion of a conductive pattern formed by printing, serving as one part of a contact system.

Tenting – A printed circuit board fabrication method of capping plated-through holes and the surrounding conductive pattern with a dry film resist.

Thin Core – Thin laminate, usually less than 0.005 inches thick.

Wedge voids – A layer separation defect in a drilled hole which are sites for retention of process chemicals.