Visible Spectrum

Light which can be seen by the unaided human eye, defined in our case as between 400 nm and 750 nm.

Void

A hole or bubble in a solder joint.

W

See Watt.

Waffle Pack

A matrix tray for holding bare die. Typically, waffle packs are 2″ x 2″ or 4″ x 4.” The pockets for die in waffle packs are typically designed for specific die sizes; they are not standardized.

WAN

See wide area network.

Watt

Linear measurement of optical power, usually expressed in milhwatts, microwatts, and nanowatts.

Wave Cleaning

Cleaning a PCB by passing it through a wave of solvents (similar to the concept used in a wave fluxer or a wave soldering process).

Wave Soldering

A process in which many potential solder joints are brought in contact with a wave of molten solder for a short period of time and are soldered simultaneously.

Waveguide

A system or material designed to confine and direct electromagnetic waves in a direction determined by its physical boundaries.

Tape Bonding

Utilization of a metal or plastic tape material as a support to a carrier of a component in a gang bonding process.

TEC

Abbreviation for thermoelectric cooler.

Temperature, Curing

The temperature to which an adhesive or an assembly is subjected to cure the adhesive. Note-The temperature attained by the adhesive in the process of setting it may differ from the temperature of the atmosphere surrounding the assembly.

Tensile Strength

The pulling force necessary to break a given specimen divided by the cross sectional area. Units given in lbs./in/2 (P.S.I.). It measures the resistance of a material to stretching without rupture. Normally is not used with reference to elastic materials which recover after elongation.

Terminal

A metallic device used for making electrical connections.

Test Pattern

A pattern used for inspecting or testing purposes.

Thermal Cycling

A method used to induce stresses on electrical components by means of sequential heating and cooling in an oven. It is used in accelerated reliability testing.

Thermal Noise

Noise resulting from thermally induced random fluctuation in current in the receiver’s load resistance.

Thermal Profile

A time versus temperature graph that displays the temperatures an assembly is subjected to over time in an oven during processes such as reflow soldering or the curing of adhesives, encapsulants, and conformal coatings.

Thermal Shock Resistance

The ability of a cured system to resist cracking or crazing under conditions of rapid and continuous thermal change. The 1/4 inch Olyphant Washer test is cycled over a temperature range of -55¡C to +125¡C, this temperature is normally used as the test condition unless otherwise stated.