Terms and Definitions

Terms and Definitions



Activated Rosin Flux (RA) -

A mixture of rosin and small amounts of organic-halide or organic-acid activators.

Activator (flux) -

A substance that improves the ability of a flux to remove surface oxides from surfaces being joined.

Air flow -

The continuous rate of air discharge during convection soldering (e.g., slpm - standard liters/minute, cfm - cubic feet/minute).

(See also "Air pressure")
Air pressure -

The volume of air applied to a surface during convection soldering, measured as forceper unit of air (e.g., bar - one million dynes/cm2,psi - pounds/square inch).

(See also "Air flow")
Annular ring -

The portion of conductive material completely surrounding a hole.

(See also "Pad")
Aqueous flux -

See “Water-soluble organic flux.”

Aspect ratio -

The ratio of the length or depth of a hole to its preplated diameter.

Aspect Ratio Assembly -

A number of parts, subassemblies, or other similar combinations joined together.
(Note:This term can be used in conjunction with other terms, e.g., “Printed Wiring Assembly.”)


American Society for Testing and Materials.

Auxiliary heating -

The heating of a large thermal mass solder joint by assisting the primary heat source with a secondary source of heat. The secondary source is usually in the form of a soldering iron, thermal tweezer, hot air pencil or heating surface (convective or conductive).