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EPO-TEK® Glossary Of Terms


C Celsius.
Measure of temperature where water freezes at O' and boils at 100'.
The final stage in the reaction of certain thermosetting resins in which the material is relatively insoluble and infusible. Certain thermosetting resins in a fully cured state are in this stage.
One or more optical fibers enclosed within protective covering(s) and strength members.
A thermal unit. A calorie is that amount of heat required to raise the temperature of one gram of water, one degree centigrade.
A printed circuit board of smaller dimensions is commonly referred to as a card. A card is generally one level lower than the printed circuit board in the hierarchy of packaging. A card is also referred to as a daughter board.
A substance which markedly speeds up the cure of an adhesive when added in minor quantity as compared to the amounts of the primary reactants.
CD Compact disk
Often used to describe high-quality audio, CD-quality audio, or short-wavelength lasers; CD Laser.
A scale of temperature which features 0¡ and 100¡ as the freezing and boiling point of water respectively. To convert centigrade to Fahrenheit multiply by 1.8 and add 32, e.g., (100¡ x 1.8) + 32 = 212¡F.
1/100th of a poise; (dyne-sec/cm2); a viscosity measurement unit.
An inorganic, nonmetallic material. Examples include alumina or glass-ceramic. Ceramics are often used in forming ceramic substrates for the packaging of semiconductor chips.
Ceramic Ball Grid Array (CBGA)
A ball grid array package with a ceramic substrate.
Ceramic Column Grid Array (CCGA)
The same as CBGA except the solder balls are replaced by solder columns. The advantage of columns is that the inherent flexibility of the columns help compensate for CTE mismatch between the ceramic component and the FR-4 board. Columns are required rather than solder balls for components greater than 25mm square.
A chlorinated fluorocarbon that can cause ozone layer depletion. The use of CFCs is restricted by the Environmental Protection Agency. CFCs are primarily used in air conditioning and refrigeration, foam insulators, and cleaning solvents.
Formation of a dry powdery chalk-like appearance or deposit on the surface of a material. It is due to a breaking down of the material after being exposed to ultraviolet light, or other weathering.
The individual circuit or component of a silicon wafer. The leadless form of an electronic component part, either passive or active, discrete or integrated.
Chip Carrier
An integrated circuit package that is usually square and may possess a cavity for a chip in the center and whose connections are typically on all four sides.
Chip-on-Board (COB)
A configuration in which a chip is directly attached to a printed circuit board or substrate by solder or conductive adhesives.
The interconnections of electrical elements and devices that perform a desired electrical function.
Material that surrounds the core of an optical fiber. Its lower index of refraction, compared to that of the core, causes the transmitted light to travel down the core.
Degree of clearness in a cured epoxy system.
An operation involving the removal of flux residues and other contaminants from the surface of a PCB assembly.
Closed-Cell Foamed Plastic
A cellular plastic in which there is a predominance of noninterconnecting cells.
Centimeter Approximately 0.4 inches.
Complementary metal oxide semiconductor. A family of IC's. Particularly useful for low speed or low-power applications.
A thin layer of material, conductive or dielectric, applied over components or a base material.
Coefficient Of Linear Thermal Expansion
Once cured, a measure of the change in length of an epoxy system over a given temperature range. It is expressed in inches per inch per degree C. ASTM D696-44.
Coefficient Of Thermal Expansion (CTE)
Change in a unit of length or volume that accompanies a unit change in temperature.
The state in which the particles of a single substance are held together by primary or secondary valence forces observed in the tendency of the substance to stick to itself. As used in the adhesive field, the state in which the particles of the adhesive (or the adhered) are held together.
An individual functional element in a physically independent body (e.g., resistor, capacitor, or transistor).
Component Lead
A wire or formed conductor that extends from a component and serves as a mechanical and/or electrical connection. Leads can readily be formed to a desired configuration.
Compressive Modulus
The ratio within the elastic limit of compressive stress to corresponding compressive strain (deformation per original length). It is expressed in pounds per square inch. ASTM D695-54.
Compressive Strength
Crushing load at the failure of a specimen divided by the original sectional area of the specimen.
Compressive Strength, Ultimate
The maximum load in pounds that can be carried per square inch of cross section of the material under test.
The thermal transmission of heat energy from a hotter region to a cooler region in the presence of a conducting medium.
Having the quality of power of conducting or transmitting heat, electricity, or static electricity.
Conductive Adhesive
Refer to "isotropic/anisotropic conductive adhesives."
Reciprocal of volume resistivity. Conductance of a unit cube of any material.
Conductor, Electrical
A class of materials-ususally metals-that easily conducts electricity. Examples include silver, copper, gold, and super-conducting ceramics.
Conductor, Thermal
A class of materials-ususally metals-that easily conduct heat. Examples include copper, aluminum, and beryllia.
Conformal Coating
A thin nonconducting coating that is either plastic or inorganic and is applied to a circuit for environmental and mechanical protection.
Contact Angle
The angle between bonding material and a bonding pad. Also called the wetting angle.
Contact Printing
A type of printing where there is no gap between the stencil and the substrate.
Contact Resistance
The maximum resistance allowed between a pin and the socket contacts of a connector when assembled and in use.
An undesirable material that can adversely influence the properties of a material or the quality of a product. A contaminant can be liquid or solid.
Continuous Tape
A TAB tape handling scheme that uses a continuous reel of polyimide tape to mount and carry TAB components through the assembly process. Typically, the tape width conforms to industry standards, with 35mm, 48mm, and 70mm widths being the most common.
The transmission of thermal energy from a hotter region to a cooler region through a moving fluid such as air or water.
The maximum distance between the lowest pin and the highest pin when a package rests on a perfectly flat surface.
A chemical action that causes the gradual deterioration of the surface of a metal by oxidation or chemical reaction.
Tying together large molecules and hence changing the physical properties of material. Cross-linking usually involves formation of three dimensional molecular network and is customarily associated with thermosetting resins.
Crosstalk (XT) 1
Undesired coupling from one circuit, part of a circuit, or channel to another. 2. Any phenomenon by which a signal transmitted on one circuit or channel of a transmission system creates and undesired effect in another circuit or channel.
Cathode ray tube.
CTE Mismatch
The difference in the coefficients of thermal expansions of two materials or components joined together, which produces strains and stresses at joining interfaces or in attachment surfaces.
To change the physical properties of an epoxy by chemical reaction through polymerization, usually accomplished in the presence of heat and catalyst, alone or in combination.
Cure Cycle
The schedule of time periods at specified temperatures to which a reacting thermosetting plastic or rubber composition is subjected in order to reach certain specified properties.
The process of irreversibly polymerizing a thermosetting plastic by subjecting it to a temperature-time profile.
Curing Agent
A catalytic or reactive agent which when added to resin causes polymerization. Back to Top
Curing Cycle
The time-temperature profile needed to cure a thermosetting material like a bonding adhesive.
Curing Time
The time needed to properly cure a thermosetting plastic material.
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