Total Board Solutions

PCB Glossary

A-B C-G H-S T-Z

ATE : Automatic Test Equipment

Annular Ring : The copper land that surrounds a drilled hole on a layer that is required to make an electrical connection with another part of the circuit. The fabricator will specify a minimum annular ring requirement based on the design technology. Factors that affect the size of the annular ring include the board thickness, number of layers and drill size.

BBT : Bare Board Test - Test performed on the bare board (un-populated) by the PCB fabricator against the design data netlist to ensure that the finished board agrees with the original data. This can be performed using a bed-of-nails or a flying probe tester.

Aspect Ratio : The aspect ration of a design is the thickness of a PCB divided by the smallest mechanically drilled hole. Manufacturer's will state the achievable aspect ratio, such as 10:1 or 8:1, for a specific design technology. The higher the aspect ratio the more difficult the board will be to fabricate and as such will increase cost.

BGA : Ball Grid Array - Integrated circuit package whose pins are formed as balls on the bottom of the device. The pins may be placed either as a fully populated array or as a courtyard pattern. Because the pins are placed in an array they are normally numbered using an alpha-numeric scheme, with the numbers and letters corresponding to rows and columns. BGA pin pitches are normally 1.0mm – 0.8mm. Some older devices do have pin pitches of 1.27mm.

Blind Via : A via that has a connection that starts on an outer-layer of a PCB and stops on a predefined internal layer. The vias can be created in a number of ways using a number of build-up technology approaches or by creating PCB sub-assemblies.

Buried Via : A via that has a connection that starts on one internal layer of a PCB and stops on another predefined internal layer. The vias can be created in a number of ways using a number of build-up technology approaches or by creating PCB sub-assemblies.