TF

Solid or seven strand copper conductor, thermoplastic insulated fixture wire. 60° C.

TFE

  1. Tetrafluoroethylene. A thermoplastic material with good electrical insulating properties and chemical and heat resistance.
  2. Polytetrafluoroethylene.

TG

Flexible nickel or nickel-clad iron or copper, or nickel conductor, PTFE tape overall glass braid, 200° C.

TGS

Solid or flexible copper, nickel-clad iron or copper, or nickel conductor. PTFE tape, silicone glass braid 600 in, 250° C.

Thermal Aging

Exposure to a given thermal condition or a programmed series of conditions for specified periods of time.

Thermal Coefficient of Expansion (TCE)

See TCE, Thermal Mismatch.

Thermal Conductivity

  1. The coefficient of heat conduction that describes the ability of a material to conduct heat--the inverse of thermal resistance, through a unit area of the material and unit temperature gradient.
  2. (VOLUME) The volume material parameter which is the inverse of thermal resistivity.

See also Thermal Resistivity.

Thermal Mismatch

Differential thermal expansion between a PCB and a component which is a vital consideration in surface mount technology. The match between the expansion coefficient of the component and the board is a critical factor.

See TCE.

Thermal Rating

The heat flow resistance parameter, compared analogously with electrical DC current resistance, both derived as a ratio of the driving force (the thermal gradient vs the voltage gradient) and the flux (heat vs electric DC current flux).

See also Thermal Resistivity.

Thermal Resistance

That change in the electrical resistance of a material when subjected to heat.

Thermal Resistivity (Volume)

The thermal resistance of a unit cube of material having an unit thermal gradient across any two parallel faces, which have two different face temperatures.

Thermal Shock

The effect of heat or cold applied at such a rate that non-uniform thermal expansion or contraction occur within a given material or combination of materials. In connectors, the effect can cause inserts and other insulation materials to pull away from metal parts.

Thermal Type

A basic connector type which requires heat from a source such as a soldering gun or welder, or from the termite type welding.

Thermal Wipe

A slight movement of mated contacts caused by thermal expansion or contraction of parts that can cause poor performance.

Thermistor

A resistor whose value changes as a function of temperature. Its temperature coefficient of resistance is usually high, nonlinear, and negative; as it heats up, its resistance lowers.

Thermocouple

A pair of dissimilar metals joined together so voltage is generated at the open ends when the junction is heated or cooled.

Thermocouple Contact

Contact of special material used in connectors employed in thermocouple applications. Materials often used are iron, constantan, copper, chromel and alumel.

Thermocouple Lead Wire

An insulated pair of wires used from the couple to a junction box or to the recording instrument.

Thermoplastic

A type of plastic (with no internal curing or cross-links) that can be re-melted a number of times without any important change in properties. The re-melting is a true melting at a fixed melting point if the plastic is a crystalline polymer; however, in the case of an amorphous polymer, a 'melt-like' state is approximated, but over a range of temperatures.

See also Thermoset.

Thermoset

One of the two main types of engineering plastics; the other being thermoplastic. The insoluble polymer undergoes a chemical reaction when heated and takes on a permanent shape. The thermoset (or cured or cross-linked ) plastic or polymer cannot be melted to fluid-like or liquid-like state at elevated temperature because: (1) thermoset plastics usually do not have a melting point; 2) are sufficiently cured or cross-linked to behave like one giant macromolecule; and 3) have some high temperature stability due to its thermoset-ness, breaking down, decomposing, or degrading with heat instead of melting.

See Cure, Cross-Link, Thermosetting Plastic.

Thermosetting Plastic

A type of plastic in which an irreversible chemical reaction takes place while it is being molded under heat and pressure. This type of plastic cannot be reheated or softened.

See Phenolic Resins, Epoxy Resins.

THHN

Nylon jacketed building wire. 600 in, 90° C.

Thick Film

A method of manufacturing hybrid circuits by screen deposition of conductive, resistive, or insulating films thicker than 0.010 inch. Thick film structures generally contain only conductors, resistors, and capacitors, with any other required components added to the hybrid as discrete devices.

Thin Film

A method of manufacturing integrated circuits by depositing thin layers of materials to perform electrical functions. Usually only passive elements are made this way.

TH or T/H

See Through-Hole Mounting.

Threaded Coupling

A means of coupling mating connectors by engaging threads in a coupling ring with threads on a receptacle shell.

Threaded Self-locking Coupling

A coupling mechanism that uses matching screw threads for mating and unmating of cylindrical connectors or devices. This design incorporates an automatically actuated locking mechanism to prevent the coupling ring from becoming loose under vibration conditions.

Threaded-type Connector

A connector in which the contact between the conductor and connector is made by pressure exerted on a threaded part.

Three Quarter Terminal

A terminal designed for solder connection, which provides a connection point on only one side of a terminal block.

Through Connection

An electrical connection between conductive patterns on opposite sides of an insulating base, e.g. plated through-hole or clinched jumper wire.

Through-Hole Mounting

Electrical connection of components through drilled holes rather than attachment directly to the insulating material.

Throw

Movement of a contact from one stationary point to another. A single throw switch has a normally open or a normally closed circuit per pole. A double throw switch has a normally open and a normally closed circuit per pole.

THW

Thermoplastic vinyl insulated building wire. Flame retardant, moisture and heat resistant. 75° C.

THWN

Same as THW, nylon jacket overall. 75° C.

Thyristor

A semiconductor switch that may have two, three or four terminals and may be unidirectional or bi-directional. DIACs, TRIACs, SCRs and UJTs fall into this category.

Tie Point

An insulated terminal to which two or more wires are connected.

Tie Wire

Wire that connects a number of terminals together.

Time Delay - Absolute (TD)

Absolute electrical length in time (nanoseconds) of an interconnect, line element, or transmission line.

See also Time Delay - Air (To), Time Delay - Normalized (Td).

Time Delay - Air (To)

Absolute electrical length in time (nanoseconds) of an interconnect, line element, or transmission line when the material medium is air. Its value is then 1.016 ns/ft or 3.333 ns/m.

See also Time Delay - Absolute (TD), Time Delay - Normalized (Td).

Time Delay - Normalized (Td)

Absolute electrical length in time (nanoseconds) of an interconnect, line element, or transmission line in a medium of dielectric constant (e). 

See also Time Delay - Absolute (TD), Time Delay - Air (To).

Time Domain

Analysis of a signal waveform in the domain of time, i.e., as a voltage- or current - time graph giving a visual display of the geometric nature of the signal as a pulse-like waveform as a function of time. Time Domain and Frequency Domain Analysis complement each other.

See also Frequency Domain.

Time Domain Reflectometer (TDR)

See TDR.

Tin (Sn)

A metallic element with atomic number 50. A common terminal plating material used on brass, copper, and (over a layer of copper flash) on steel terminals. It provides high conductivity at low cost, and is often used on terminal components that will be in contact with aluminum to reduce galvanic corrosion.

Tin Lead

An alloy used for the majority of soldering operations in the electronics industry. Usually, an alloy close to the eutectic composition (62 percent Sn, 38 percent Pb) is chosen to permit usage of the lowest possible soldering temperature (181°C or 360°F), thereby reducing risk of damage to temperature-sensitive components.

Tin Overcoat (TOC)

Tinned copper wire, stranded, then coated with pure tin.

Tin Reel-to-Reel Line

Process of gold/tin plating pins, terminals, or raw material strips on reels. The tin reel-to-reel plating is usually overall plating, but gold is selective plating. The speed of a reel-to-reel line is measured in meters per minute and it ranges from 2-10 meters per min depending on the surface areas plated and the plating thickness.

Tinsel

A type of electrical conductor comprised of a number of tiny threads, each thread having a fine, flat ribbon of copper or other metal closely spiraled about it. Used for small size cables that requires limpness and extra long flex life.

TL

See Transmission Line.

TMDS

Transfer Minimizer Differential Signaling