Saturn Solutions Ltd

Glossary of Terms

General

1. CAD - Computer Aided Design.

2. CAM - Computer Aided Manufacture.

3. Pin Out - The arrangement of inputs and outputs on an Integrated Circuit.

4. Gerger File - Gerber is a format which store all the relative coordinates of a PCB for production by the PCB manufacturer. It has been adopted as the industry standard because of its flexibility and reliability.

PCB Related Terms

1. Conventional - A rigid PCB with wire-leaded components mounted on only one side of the board with all the leads inserted through holes and soldered into position. Conventional assembly is generally easier to analyse and repair than surface mount.

2. Surface Mount Technology (SMT) - A PCB with tag leaded components soldered flush to solder pads. Holes are still required but not for component leads. Surface mount is generally more compact than conventional and is more suited to automated assembly.

3. Mixed - A mixture of surface mount and conventional components. There are disadvantages associated with the different soldering techniques required on this type of assembly.

4. Hybrid - A PCB that has both tracks and some components (normally resistors) already printed on it, ready to receive either or both surface mount and/or conventional devices.

5. Double sided - A PCB laminate with tracks on both sides, normally with plated through holes connecting circuitry on the two sides together.

6. Plated Through (Thru) Hole (PTH) - The holes are copper plated providing a circuit between sides of the PCB.

7. Double sided Assembly - Mounting components on both sides of a PCB. This would normally only be appropriate for SMT or mixed component assemblies.

8. Multi-layer - A PCB may be manufactured with more than two layers of copper tracks by sandwiching tracks within the laminate. This enables much more complex circuitry to be incorporated into a PCB but the cost reflects the number of layers.

9. Gold plated - Some parts of a PCB may be gold plated for use as contact pads. (Usually pads at the edge of the board.)

10. Flexible PCB - A flexible circuit widely used with membrane keyboards and circuits required to fit into small and awkward spaces.

11. Chip On Board (COB) - An IC is attached directly to a PCB with bond out wires connected directly to the surface of the board. (The IC has no casing or legs connected.) The chip is then protected with a layer of black epoxy. This type of technology is used mainly for cost saving in mass production applications.

12. Daughter board - A PCB mounted (piggy backed) onto another circuit board.