PCB GLOSSARY

PCB & Electronic Assembly Glossary
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Active Component: Electronic components that require power to operate (e.g., transistors, ICs).
Annular Ring: The copper ring around a drilled hole in a PCB pad.
AOI (Automated Optical Inspection): Machine-based inspection of solder joints and component placement.
Aspect Ratio: Ratio of PCB thickness to hole diameter, affecting plating quality.
Assembly Drawing: Visual guide showing component placement and orientation.

Ball Grid Array (BGA): Surface mount package with solder balls underneath.
Bare Board: PCB without any components mounted.
Bill of Materials (BOM): List of all components required for assembly.
Blind Via: Via connecting outer layer to inner layers without passing through the entire board.
Buried Via: Via connecting only inner layers, not visible externally.

CAD (Computer-Aided Design): Software used to design PCB layouts.
Capacitance: Ability to store electrical charge.
Conformal Coating: Protective chemical layer applied to assembled PCBs.
Component Side: Side of the PCB where components are mounted.
Copper Weight: Thickness of copper on PCB layers, measured in oz/ft².
Creep Corrosion: Corrosion that spreads across PCB surfaces, often due to environmental factors.

Design for Manufacturability (DFM): Design approach to simplify manufacturing.
Design Rule Check (DRC): Automated check for layout violations.
Dielectric: Insulating material between conductive layers.
Double-Sided PCB: PCB with copper traces on both sides.

Electroless Plating: Chemical deposition of metal without electricity.
Electromagnetic Compatibility (EMC): Ability of a device to operate without interfering with others.
Electromagnetic Interference (EMI): Unwanted electrical noise affecting performance.
Etching: Process of removing unwanted copper from PCB.

Fab Drawing: Blueprint for PCB fabrication.
Fiducial Marks: Reference points for automated assembly alignment.
Flux: Chemical used during soldering to improve wetting and prevent oxidation.
Functional Test: Electrical test to verify circuit operation.

Gerber Files: Standard file format for PCB manufacturing data.
Ground Plane: Large copper area connected to ground, used for noise reduction.

Halogen-Free PCB: Environmentally friendly board without halogenated flame retardants.
HASL (Hot Air Solder Leveling): Surface finish using molten solder and hot air.
HDI (High-Density Interconnect): PCB with fine features and microvias.

Impedance Control: Design technique to manage signal integrity.
IPC Standards: Industry standards for PCB design, assembly, and inspection.
In-Circuit Test (ICT): Electrical test using probes to check individual components.

Jumper: Wire or trace used to connect two points on a PCB.
J-STD-001: IPC standard for soldering quality and workmanship.

Kapton Tape: Heat-resistant tape used during soldering and rework.

Lamination: Process of bonding PCB layers together.
Laser Drilling: Precision method for creating microvias.
Legend: Printed text on PCB for component identification.

Microvia: Very small via used in HDI boards.
Multilayer PCB: PCB with more than two copper layers.
Moisture Sensitivity Level (MSL): Classification of components based on moisture tolerance.

Netlist: List of electrical connections between components.
Non-Plated Through Hole (NPTH): Hole not plated with copper, used for mounting.

Open Circuit: Break in electrical continuity.
Overlay: Silkscreen layer showing component outlines and labels.

Pad: Copper area where components are soldered.
Pick and Place: Automated machine placing components on PCB.
Plated Through Hole (PTH): Hole with copper plating for electrical connection.
Prepreg: Fiberglass material impregnated with resin, used in PCB layers.

QFP (Quad Flat Package): IC package with leads on all four sides.
Quality Assurance (QA): Systematic process to ensure product quality.

Reflow Soldering: Heating process to melt solder paste and attach SMT components.
Resin: Material used in PCB substrates for insulation and strength.
RoHS (Restriction of Hazardous Substances): EU directive limiting hazardous materials in electronics.

Silkscreen: Printed layer showing component labels and logos.
Solder Mask: Protective layer preventing solder bridging.
Surface Mount Technology (SMT): Method of mounting components directly onto PCB surface.
Stencil: Metal sheet used to apply solder paste to PCBs.

Test Point: Location on PCB used for electrical testing.
Thermal Relief: Design feature aiding heat flow during soldering.
Through-Hole Technology (THT): Mounting components via holes in the PCB.

Ultrasonic Cleaning: Method for removing contaminants using high-frequency sound waves.

Via: Hole connecting different PCB layers.
V-Scoring: Groove cut into PCB for easy separation.

Wave Soldering: Soldering method for THT components using a wave of molten solder.
Wire Bonding: Technique for connecting ICs to PCB using fine wires.
Wetting: Ability of solder to adhere to a surface.

X-Ray Inspection: Non-destructive method to inspect hidden solder joints (e.g., BGAs).

Zero Defects: Quality goal aiming for no manufacturing errors.