PCB Terms

Use of Surface Roughness Symbols

The roughness of any surface, except cast surfaces, may be expressed by the use of symbols and numerical ratings. The finish mark symbols are used to designate the applicable surface. The numerical rating indicates the roughness of that surface.

Bridging:

A condition that generally happens during the wave soldering operation where excess solder builds up and shorts out the adjacent traces.

Control of Surface Roughness

The roughness of any surface is determined by design requirements rather than by production processes: however, over control will increase the cost of production. Therefore, specify surface roughness control on drawing only when it is essential to the appearance or mechanical performance of the product.

Spacing:

The nonconductive space between traces, pads, conductive matter, or any combination thereof.

Analog Circuit:

A circuit comprised mostly of discrete components (i.e., resistors, capacitors, transistors) which produces data represented by physical variables such as voltage, resistance, rotation, etc.

Annular Ring:

The width of the conductor surrounding a hole through a Printed Circuit Pad.

Artwork:

An accurately scaled configuration used to produce a Master Pattern. Generally prepared at an enlarged scale using various width tapes and special shapes to represent conductors. Artwork can also be created by using computer and laser photo plotter.

AWG:

American Wire Gauge. A method of specifying wire diameter. The higher the number, the smaller the diameter.

Axial Leads:

Leads coming out of the ends and along the axis of a resistor, capacitor, or other axial part, rather than out the side.

Bus:

A Heavy trace or conductive metal strip on the Printed Circuit Board used to distribute voltage, grounds, etc., to smaller branch traces.

Bypass Capacitor:

A capacitor used for providing a comparatively low impedance A-C patharound a circuit element.

Conformal Coat:

A coating that is generally sprayed, dipped, or screened on to provide the completed Printed Circuit Board protection from fungus, moisture and debris.

Connector Tongue:

A protrusion of the Printed Circuit Board edge that is manufactured to a configuration to mate with a receptacle that provides electrical and/or mechanical junction between the Printed Circuit Board and other circuitry.

Digital Circuit:

A circuit comprised of mostly integrated circuits which operates like a switch(i.e., it is either "ON" or "OFF").