PCB Glossary

The following terms are used in connection with the design and fabrication of custom printed circuit boards (PCBs):

Analog Circuit - an electrical circuit that provides a continuous quantitative output as a response from its input.

Automated Test Equipment (ATE) - equipment that automatically tests and analyzes functional parameters to evaluate performance of the tested electronic devices.

Built-In Self Test - an electrical testing method that allows the tested devices to test itself with specific added-on hardware.

CAD - Computer Aided Design.

CAM - Computer Aided Manufacturing.

Chip - the individual circuit or component of a silicon wafer, the leadless form of an electronic component.

Design For Manufacturing (DFM) - checks that ensure that the design fits the fabrication process requirements.
DFM includes a check for minimal trace width, minimal trace-to-trace distance, minimal hole clearance, etc.

Dielectric - an insulating medium between conductors.

DIP - dual in-line package with two rows of leads from the base in standard spacing between the leads and row. DIP is a through-hole mounting package.

DRC - Design Rule Check.

Edge Connector - a connector on the circuit-substrate edge in the form of plated pads or lines of coated holes used to connect other circuit board or electronic device.

Electronic Component - a part of the printed circuit board, such as resistor, capacitor, transistor, etc.

Fine Pitch - fine pitch is more commonly referred to surface-mount components with a lead pitch of 25 mils or less.

Footprint - geometry of pads for soldering certain electronic component.

Functional Test - the electrical testing of an assembled electronic device with simulated function generated by the test hardware and software.

Gerber File - data file used to control a photo-plotter.

Ground Plane - a conductive plane as a common ground reference in a multilayer board for current returns of the circuit elements and shielding.

IC - Integrated Circuit.

In-Circuit Test - electrical test of individual component or part of the circuit board instead of testing the whole circuit.

Leakage Current - A small amount of current that flows across a dielectric area between two adjacent conductors.

Legend - Printed letters or symbols on the board, such as part numbers and product number or logos.

Minimum Conductor Width - The smallest width of any conductors, such as traces, on a board.

Minimum Conductor Space - The smallest distance between any two adjacent conductors, such as traces, on a board.

Net - a set of pads that are to be connected electrically on the board.

Netlist - List of parts and their connection points which are connected in each net of a circuit.

NPTH - Non-plated through-hole.

Pad - Metallized area of the board for connection and attachment of electronic components.

PCB - Printed Circuit Board.

Pin (pinout) - part of an electronic component which is soldered to the board.

Pitch - the center-to-center spacing between conductors, such as pads and pins, on a board.

Plastic Leaded Chip Carrier (PLCC) - a component package with J-leads.

PTH (plated-through hole) - a plated hole used as a conducting interconnection between different layers or sides of a board either used as connection for through-hole component or as a via.

Routing (tracing) - the process of placing electronic connections (traces) between pads on the board.

Signal layer - layer of a board, in which traces can be placed. For a two-sided board two signal layers are available - the Top and the Bottom layers.

Silk screen - a layer designed for placing legend elements on the top or bottom side of the board. Two corresponding layers are available - the Top Silk and the Bottom Silk.

Small Outline Integrated Circuit (SOIC) - an integrated circuit with two parallel rows of pins in surface mount package.

SMD - Surface Mount Device.

SMT - Surface Mount Technology.

Test Point - a specific point in a circuit board used for specific testing for functional adjustment or quality test in the circuit-based device.

Thermal pad - pad of a special form used when it is connected to copper pours. Thermal pads improve solderability of the joint, reducing the chance of a so called " cold solder joint " .

Through-hole - a drilled hole in the board, usually for mounting purposes.

Trace (or Route) - a layout or wiring of an electrical connection.

UL - Underwriter's Laboratories. A popular safety standard for electrical devices supported by many underwriters.

Via - a plated-through hole used for interconnection of conductors on different sides or layers of a circuit board.

Wave Soldering - a manufacturing operation in which solder joints are soldered simultaneously using a wave of molten solder.