PCB glossary

Automated optical inspection of circuits, which consists in comparing an actual image of scanned PCB with a Gerber file image used in PCB fabrication.

The term comes from the days of vector photo plotters, where film was exposed by shining light through apertures arrayed around the edge of a disk (or “aperture wheel”). Each aperture corresponded to a different D code in the Gerber data. Today, photoplotters use lasers to expose the film but the term “aperture” persists and describes the shape and size of the tool used to create a pad or track.

The electrodeposition of copper coating inside the through holes in double or multilayer PCBs.

Hot Air Levelling or Hot Air Solder Levelling -tin plating of copper areas on external layers without a solder mask.

Used in devices with complex conducting pattern, where pads and traces are on both sides and also there are traces embedded within the board. Techno-Service S.A. is able to provide 4-, 6- and 8-layer boards.

Through Hole which does not provide electrical connections between conductive patterns at the levels of a printed circuit. NPHT is often used for mechanical assembly of printed circuit boards.

General fabrication process of single and double sided PCBs:

Drilling -> Photolithography -> Etching -> Plating -> Solder mask -> HAL or gold plating -> Milling, scoring -> Testing -> Final inspection -> Packaging and dispatch.

A hole to provide electrical connections between conductive patterns at the levels of a printed circuit board and installation of THT components.

Restriction of Hazardous Substances, is a European legislation intended to eliminate or severely curtail the use of lead, mercury, cadmium, hexavalent chromium, PBB and PBDE in products marketed in the EU and EFTA introduced on 1 July 2006 (27 march 2007 in Poland)..

Coloured marks (usually white) on the PCB board to identify components on external sides of the board, coated with solder mask.

Used in devices with simple, single layer conducting pattern. The pads and tracks are on the soldering side of the board only.

The name is derived from single sided technology and it is used to describe the side of a printed circuit board (with conductive pattern) on which components are soldered. In SMD mounting technology for double sided and multilayer PCB, it is the BOTTOM side of the PCB.

We offer two types of end copper plating: HAL (standard) and chemical gold plating.

A plated through hole (PTH) in a Printed Circuit Board to provide electrical connection between all conductive layers. Since it is not used to mount component leads, hole and pad diameters are usually small (0.2 mm – 0.5 mm).