printed circuit board

(redirected from PCB board)
Also found in: Dictionary.

printed circuit board

[′print·əd ′sər·kət ‚bȯrd]
A flat board whose front contains slots for integrated circuit chips and connections for a variety of electronic components, and whose back is printed with electrically conductive pathways between the components. Also known as circuit board.

Printed Circuit Board


a board whose surfaces have printed current conductors with contact areas, which are used to connect components mounted on the boards according to the circuit diagram of a functional subassembly for electric or radio apparatus, and also have plated circuit holes and nonplated mounting holes. There are about 200 methods for making printed circuit boards; among the most important are the photochemical, photoelectrochemical, and offset-electrochemical methods. The methods differ in the means of producing the conductive coating or the form in which the pattern of the printed conductors is realized.

The dimensions of printed circuit boards, the position of the hole centers, and the hole diameters are standardized. The boards are 10–360 mm long, 10–240 mm wide, and 0.05–3.0 mm thick (depending on the rigidity required). The spacing of the coordinate grid for marking the holes is 2.5 mm or, less frequently, 1.25 mm, and the hole diameters range from 0.2 to 3 mm. A distinction is made among one-sided, two-sided, and multilayer boards (up to 15 layers). Multilayer boards are made by using extended leads, by metallizing the walls of through holes, by molding two-sided boards in pairs, or by layer-by-layer buildup. The material most often used for printed circuit boards are metal-clad and plain Micarta and fiberglass laminates, reinforced fluorine plastic, polystyrene, polyethylene terephthalate, polyamide, polycarbonate, and radioceramics.


Konstruirovanie i tekhnologiia pechatnykh plat. Moscow, 1973.


printed circuit board

(PCB) A thin board to which electronic components are fixed by solder. Component leads and integrated circuit pins may pass through holes ("vias") in the board or they may be surface mounted, in which case no holes are required (though they may still be used to connect different layers).

The simplest kind of PCB has components and wires on one side and interconnections (the printed circuit) on the other. PCBs may have components mounted on both sides and may have many internal layers, allowing more connections to fit in the same board area. Boards with internal conductor layers usually have "plated-through holes" to improve the electrical connection to the internal layers.

The connections are metal strips (usually copper). The pattern of connections is often produced using photo-resist and acid etching. Boards, especially those for high frequency circuits such as modern microprocessors, usually have one or more "ground planes" and "power planes" which are large areas of copper for greater current carrying ability.

A computer or other electronic system might be built from several PCBs, e.g. processor, memory, graphics controller, disk controller etc. These boards might all plug into a motherboard or backplane or be connected by a ribbon cable.

printed circuit board

A rigid, flat board that holds chips and other electronic components. The board is made of layers, typically two to 10, that interconnect components via copper pathways. The main printed circuit board (PCB) in a system is called a "system board" or "motherboard," while smaller ones that plug into the slots in the main board are called "boards" or "cards." See flexible circuit.

Etched Circuits
The "printed" circuit is an etched circuit. A copper foil is placed over a fiberglass or plastic base of each layer and covered with a photoresist. Light is beamed through a negative image of the circuit paths onto the photoresist, hardening the areas that will remain after etching. When passed through an acid bath, the unhardened areas are washed away. The finished layers are then glued together. A similar process creates the microminiaturized circuits on a chip (see chip).

Starting in the 1940s
Printed circuits were first used in the 1940s to connect discrete components together. By the 1960s, PCBs were widely used in all electronic systems, but still mostly connecting discrete components. Integrated circuits (chip) were emerging and added to the boards, and by the 1980s, PCBs were holding large quantities of chips. Today, printed circuit boards typically connect mostly chips with only a few discrete components, each chip containing from a few thousand up to hundreds of millions of transistors. See surface mount, via, discrete component, chip, card and motherboard.

Motherboard and Expansion Cards
This Baby AT board is an example of an early PC motherboard that used an ISA bus. It accepted both ISA and PCI cards containing peripheral controllers.

They Can Be Very Small
This WOW HD board from SRS, which has an audio jack for headphones on the end of the cable, creates a more dynamic audio experience for music listeners. The complex processing that takes place on this tiny board was unthinkable in the early days of computing. (Images courtesy of SRS Labs, Inc.,
References in periodicals archive ?
How can we expect proper cricketing decisions when the PCB Board of Governors doesn't have a single cricketer in its fold?
Automation Tools ASM Assembly Systems (Siplace Bulkfeeder X) Bonders Palomar Technologies (3880 Die Bonder) Coatings/Encapsulants Aculon (NanoProof PCB Repellency) Cleaning Equipment Seika Machinery (Unitech UC-250M-CV PCB Board Cleaner) Cleaning Materials Kyzen (Aquanox A8820) Component Placement--High Speed Fuji America (LCR Unit) Component Placement--Multifunction Kurtz Ersa (Ersa Roboplace) Component Storage Inovaxe (InoAuto Smart Cart) Device Programming Data I/O (LumenX) Dispensing Equipment Techcon Systems (TS5624 Disposable Diaphragm Valve) Process Control Tools Seika Machinery (RCX Series Modular Reflow Oven Profiling System) Rework & Repair Tools BEST Inc.
Ashraf said that the PCB board of governors expressed concern at a meeting on Saturday in Lahore.
As a consequence, the common-mode voltage was assumed to be constant over all frequencies and its magnitude was only affected by the PCB board size.
With the dip solder contacts the connectors can now be mounted to a PCB board. The 7/8" connectors are ideally suited for power supplies, Fieldbus and Ethernet applications. offers a variety of high quality products such as Automated Pcb Assembly (, Printed Circuit Board Assembly (, Rigid PCB Board ( and many more.
* Real-estate savings of up to 10 percent on the PCB board and up to 20 percent inside the technology cabinet.
I've clad the inside with large sheets of copper coated PCB board, which gives the interior a warm glow."
The high-speed ATCA backplane offers up to triple the performance of traditional versions at a reduced cost by using Z-plane Links, which carry high-speed signals with long traces via a small PCB board that plugs directly into the rear of the backplane.
Naghmi said that it is now up to the new PCB board to pursue the matter of Asif's case.
PrintDreams has launched the RMPT Technology which integrates the functionality of an entire desktop printer, which has more than 300 mechanical parts, into one single PCB board solution.
ENGLAND'S one-day series with Pakistan is set to go ahead as planned after the hosts accepted an 'unequivocal assurance' from PCB Board chairman Shaharyar Khan that they will complete their tour commitments.