Common Terminology Glossary of PCB/PCBA (Classified by Application Scenarios)
PCB Design Phase
ERC - Electrical Rule Check: Verifies the rationality of electrical connections in the schematic diagram, such as open circuits, short circuits, unconnected pins and other issues.
DRC - Design Rule Check: Conducts compliance verification on PCB layout, covering manufacturing constraints such as line width, spacing, and via size.
Gerber - Gerber File: Standard file format for PCB manufacturing, containing graphic information of each layer such as copper foil, silk screen, and solder mask.
BOM - Bill of Materials: Lists the model, specification, quantity and other information of all components required for the product, and is the core basis for procurement and production.
DFM - Design for Manufacturability: Considers production process requirements during the design phase to reduce manufacturing costs and improve yield.
PCB - Printed Circuit Board: A carrier that supports and connects electronic components, realizing circuit functions through conductive lines.
PCB Manufacturing Phase
Inner Layer Etching: A process that removes excess copper foil from the inner substrate to form inner circuit patterns.
Outer Layer Imaging: Transfers circuit patterns to the outer substrate of PCB through photolithography technology, preparing for subsequent etching.
Electroless Copper Plating: Deposits a thin layer of copper on the surface of insulating substrate through chemical reaction without electrification, realizing interlayer conductive connection.
Electroplating Copper: Further thickens the copper layer by electrification on the basis of electroless copper plating, improving the conductivity and reliability of the circuit.
Solder Mask Coating: Coats solder mask ink on the PCB surface to protect non-soldering areas, prevent short circuits and improve insulation performance.
Legend Printing: Prints component labels, models and other identifiers on the PCB surface to facilitate assembly, maintenance and identification.
Immersion Gold (ENIG): Deposits a gold layer on the pad surface through displacement reaction, with good conductivity, oxidation resistance and solderability.
Electroplated Nickel Gold (ENEPIG): Plates nickel first as a base and then gold, enhancing the adhesion of the gold layer, suitable for high-reliability soldering scenarios.
Immersion Tin: Deposits a tin layer on the pad surface, with low cost, which can prevent copper surface oxidation and ensure soldering quality.
Immersion Silver: Deposits a silver layer on the pad surface, with excellent conductivity and simple process, suitable for scenarios requiring high signal integrity.
Hot Air Solder Leveling (HASL): Dips the PCB into molten tin-lead alloy, then uses hot air to blow flat excess solder, making the pad covered with a uniform solder layer.
Mechanical Drilling: Forms through holes for component insertion or interlayer connection by rotating and cutting the substrate with a drill bit, suitable for large-diameter processing.
Laser Drilling: Uses high-energy laser to ablate the substrate to form micro holes, suitable for blind hole and buried hole processing of high-density PCB.
Blind Via: A hole that only connects the surface layer and a certain inner layer of the PCB, not penetrating the entire substrate, which can improve wiring density and reduce signal interference.
Buried Via: A hole completely located between the inner layers of the PCB, not connected to the surface layer, used for interconnection of inner circuits without occupying surface space.
Through Hole: A hole that penetrates the entire PCB substrate, which can be used for component insertion and interconnection of various layers of circuits, and is the most basic hole type.
Lamination: A process that bonds multiple layers of substrates (including inner circuits and prepregs) into one under high temperature and high pressure to form a multi-layer PCB.
Oxidation for Lamination (Brown Oxide Treatment): Performs oxidation treatment on the inner copper surface of the PCB to form a rough brown oxide layer, enhancing the bonding force during lamination.
Routing Profiling: Cuts the PCB substrate with a milling cutter to process it into the shape and size required by the design.
V-CUT (V-Groove): Processes V-shaped grooves on the edge of the PCB or between panels to facilitate subsequent depaneling, and the edge is flat after depaneling.
PCB/PCBA Testing Phase
Bare Board Test (BBT): Tests the PCB substrate without assembled components, verifies the conductivity and insulation of the circuit, and eliminates manufacturing defects.
Flying Probe Test: Performs electrical testing on the PCB through movable probes, without the need to make special test fixtures, suitable for small-batch and multi-variety products.
Bed of Nails Test: Uses fixed-arranged probes (bed of nails) to perform batch electrical testing on the PCB, with high testing efficiency, suitable for mass production.
Electrical Test: Generally refers to testing the electrical performance of PCB/PCBA, including multiple indicators such as conductivity, insulation, and impedance.
Short Circuit Test: Detects whether there are abnormally conductive short circuits between PCB/PCBA circuits to avoid damaging components after power-on.
Open Circuit Test: Detects whether there are disconnected open circuits in PCB/PCBA circuits to ensure normal transmission of circuit signals.
Insulation Resistance Test: Detects the resistance value between adjacent insulated circuits or between circuits and ground in PCB/PCBA to evaluate insulation performance.
Continuity Resistance Test: Detects the resistance value of the conductive circuit of PCB/PCBA to ensure good circuit connection and meet the requirements of conductive performance.
Impedance Test: Detects the characteristic impedance of the PCB transmission line to ensure impedance matching with components, guarantee signal integrity and reduce signal reflection.
DFT Test - Design for Testability Test: Verifies whether the PCB design is convenient for subsequent testing, ensuring reasonable layout of test points and meeting test coverage requirements.
Automated Optical Inspection (AOI): Uses optical imaging technology to automatically detect soldering defects on the PCBA surface, such as cold soldering, missing soldering, component misplacement, etc.
Automated X-ray Inspection (AXI): Uses X-rays to penetrate the PCBA, detects the internal soldering situation of packaged components such as BGA and QFN, and identifies hidden defects.
Electroluminescence Test (EL): Makes components produce electroluminescence by applying voltage, and detects internal defects of semiconductor components (such as LEDs, photovoltaic modules).
Cross-section Analysis: Makes PCB/PCBA into metallographic sections, observes the internal structure through a microscope, and evaluates soldering quality, lamination quality, etc.
Thermal Shock Test: Alternately places PCB/PCBA in high-temperature and low-temperature environments, tests its reliability under extreme temperature changes, and identifies defects caused by thermal stress.
Solderability Test: Tests the soldering performance of PCB pads or component pins to ensure the formation of good solder joints during the soldering process.
Warpage Test: Detects the bending deformation degree of PCB/PCBA to ensure its shape and size meet the assembly requirements and avoid affecting subsequent assembly.
X-Ray Inspection for PCBA: X-ray inspection for PCBA, focusing on identifying hidden soldering defects (such as under BGA).
Functional Test (FT): Powers on the PCBA, tests whether it can realize the designed electrical functions, and verifies whether the product performance meets the requirements.
In-Circuit Test (ICT): Contacts the test points of the PCBA through test fixtures, detects components and circuits one by one, and identifies manufacturing and assembly defects.
Burn-in Test: Operates the PCBA under stress conditions such as high temperature and rated voltage for a long time, screens out early failed products, and improves product reliability.
Salt Spray Test: Places the PCBA in a salt spray environment to test its corrosion resistance, suitable for products used outdoors or in harsh environments.
Vibration Test: Places the PCBA in a vibration environment to test its structural stability and solder joint reliability, simulating the vibration conditions during transportation or use.
PCBA Related (Assembly and Components)
PCBA - Printed Circuit Board Assembly: Finished circuit board after component soldering and testing.
Surface Mount Technology Placement (SMT): A technology that mounts surface mount components directly on the PCB surface without drilling.
Dual In-line Package Insertion (DIP): A process that inserts the pins of dual in-line package components into PCB through holes and solders them.
Reflow Soldering: A soldering process that heats the solder paste to a molten state through a reflow oven to solder surface mount components to the PCB.
Wave Soldering: A soldering process that forms a solder wave through a solder pot, and the PCB passes through the solder wave to solder through-hole components.
Rework: The process of repairing defective solder joints or components on the PCBA to restore product performance.
BGA Rework: The process of repairing BGA components on the PCBA, including removing, reballing and reinstalling BGA components.
SMD - Surface Mount Device: Components that are directly mounted on the PCB surface without drilling, featuring small size and high mounting efficiency.
THT - Through-Hole Technology: A process where component pins pass through the PCB substrate and are soldered, suitable for components with high power and high mechanical strength requirements.
BGA - Ball Grid Array: A package where pins are distributed in the form of a spherical solder joint array at the bottom of the component, featuring high pin density and good heat dissipation.
MCU - Microcontroller Unit: A single-chip microcomputer integrating CPU, memory and peripheral interfaces, which is the core of the embedded system.
FPGA - Field-Programmable Gate Array: A semiconductor device that can be configured through programming, suitable for high-speed and complex digital circuit design.
EMC - Electromagnetic Compatibility: The ability of equipment to work normally in an electromagnetic environment without interfering with other equipment.
IPC - Institute for Printed Circuits: An authoritative organization that formulates industry standards for PCB design, manufacturing, assembly, etc.
RF - Radio Frequency: A high-frequency AC changing electromagnetic wave band, often used in wireless communication circuit design.
