PCB Glossary

Courtyard pattern: Related to BGA pin patterns; a courtyard pattern is when an area of the pin array is not populated with balls so that this forms a square which resembles a courtyard. The area may be the complete middle section or it can be a moat area – pins placed in the middle of the device followed by a gap, then more pins towards the edge.

CSP: Chip Scale Package – Integrated circuit package similar to a BGA. What distinguishes the CSP from the BGA is that the package size is no greater than 20% of the bare die size.

Die: The semiconductor substrate containing the integrated circuit.

EMC: Electromagnetic compatibility understanding and management of unintentional creation, propagation and reception of electromagnetic energy which may cause unwanted effects such as electromagnetic interference (EMI) or even physical damage in operational equipment.

Finished Drill Hole Size: The size of hole that you want the board to be delivered with. Fabricators will drill the hole larger than the finished hole size to allow for the thickness of the plating which will be added during the fabrication process to create a connection between the top, inner layers and bottom surfaces of the hole. The drilled hole size should be taken into account when calculating the annular ring.

Functional Testing: A test performed on a populated PCB at the end of the manufacturing process to determine if the product performs to specification and can be shipped. The board is automatically subjected to a pre-defined set of test vectors /stimulus with the results determining whether the design passes or fails.

Gap: One part of a term widely used in the industry, “track and gap”, the gap is the dimension or clearance between two traces on a PCB. The desired gap can vary dependent on the design parameters such as voltages, crosstalk and other electrical considerations. The fabricator will also specify a minimum gap for maufacturing purposes on your design.

Guide: This is the term used by some CAD systems for an element that graphically shows the connection between component pins. As the designer adds the copper connections to the design the guides generally disappear to show that the connection is complete. They are also know as fromtos and rats tails or rats nest.

Gull Wing: A type of surface mount lead formation where the component lead is bent in such a way as to resemble the letter S or a gull wing. The corresponding copper pad connection is external to the component body. This lead formation is found on variety of devices such as SOICs and QFPs.