Absorption. The retention of moisture by a substance.
Accelerated Stress Test. A test to deliberately produce a
failure.
Acceptable Quality Level (AQL). Maximum number of defects
per 100 pieces that are allowable.
Acceptance Tests. Tests deemed necessary to determine the
acceptability of products.
Accuracy. (1) The ability to hit the target. (2) Conformity
of a measured value to the actual value of the sample.
Acoustic Microscopy. A nondestructive test that produces high
resolution ultrasonic images, often used for inspecting component
lid seals and die attach within components.
Acrylic. A monomeric acrylate or methacrylate (acrylic acid
or a derivative thereof) cured in a polymerization reaction
brought on by ultraviolet energy, heat, or a combination of
the two.
Acrylic Resin. A thermosetting, transparent, flame resistant
resin.
ACS. American Chemical Society
Activated Carbon. A water treatment medium, commonly used
for de-chlorination and for reducing organic chemicals and radon
from water. Activated Carbon is produced by heating carbonaceous
substances (bituminous coal or cellulose-based substances such
as wood or coconut shell) to 700罜 or less in the absence of
air to form a carbonized char, and then activating (oxidizing)
at 800 to 1000罜 with oxidizing gases such as steam and carbon
dioxide to form pores, increasing the surface area of this adsorbent
material. It can be in block, granulated, or powdered form.
Activated Rosin Flux. Flux, Rosin Activated
Activator. Thermally reactive compounds (such as amine hydrochlorides
or various halides) that break down at elevated temperatures
and enhance the ability of a flux to remove oxides and other
contaminants from surfaces being joined.
Active Components. Electronic components such as semiconductors,
transistors, diodes, etc., that can change the characteristics
applied electrical signal.
Active Hold-Down. The process of pressing a component lead
directly in contact with a bonding pad during soldering to ensure
intimate contact between the lead and pad.
Activity. (1) Activities may consist of moving or handling
materials and components, changing machine or tool settings,
turning equipment on or off, etc. Poorly control of activities
can create process variability and varying quality. (2) Flux
Activity
ADC. Analog-To-Digital Converter
Additive Plating. Plating, Additive
Adhesion. The state in which two surfaces are held together
by interfacial forces which may consist of valence forces or
interlocking action.
Adhesion, Mechanical. Adhesion between surfaces in which the
adhesive holds the parts together by interlocking action.
Adhesive. A substance capable of holding material together
by surface attachment.
Adhesive, Anisotropic. An adhesive with a low concentration
of metal particles to permit conduction in the z-axis only.
Adhesive, Conductive. A two part system comprised of a polymer
base and a conductive filler.
Adhesive Failure. Failure resulting from insufficient bond
between the adhesive and one or both substrates. Adhesive strips
away from substrates.
Adhesive Specific. Adhesion between surfaces which are held
together by valence forces or molecular bonding.
Adhesive Tensile Loading. When the acting forces are applied
at right angles to the plane of the adhesive. The tensile strength
of a bond is the maximum tensile load per unit area, required
to break the bond expressed in pounds per square inch.
Adhesive, Thermoplastic melt on application. The process is
reversible.
Adhesive, Thermoset undergo a chemical change during heating.
The change is not reversible. Epoxies and acrylics are thermosets.
AFM. See atomic force microscope.
Ag. Chemical symbol for the element silver.
Aging. The change in the properties of a material over time
and under varying conditions of humidity, temperature, pressure,
etc.
Air Knife. (1) A mechanical air pressure amplifier. (2) A
plenum with a narrow opening used develop high velocity air
from a low pressure air source to (a) dry / remove liquid films
from surfaces (b) control the coating of surfaces, or (c) heat
or cool.
Algorithm. A set of rules specifying a sequence of actions
taken to solve a problem.
Alignment Hole. Tooling Hole
Alloy. A substance made by melting two or materials together.
Alumina. A common substrate material composed of approximately
95% Al2O3.
Ambient Level. The values of signals and noise that exist
at a test location when the device under test is not active.
Amorphous Phase. Non-crystalline. Most plastics are amorphous
at processing temperature. Many retain this strength under normal
temperatures.
Analog Circuit. An electrical circuit that provides a continuous
relationship between its input and output.
Analog-To-Digital Converter (ADC or A/D converter). An electronic
circuit that produces a digital output directly proportional
to an analog signal input.
Anechoic Chamber. An enclosure especially designed with walls
that absorb sound or radiation, creating an essentially free-field
environment for testing.
Angle Of Attack. The angle between the squeegee and the stencil
or screen.
Angstrom. A unit of length equal to one hundred-millionth
(10^-8) of a centimeter, often used to specify radiation wavelengths.
Anion. An ion with a negative charge. An anion [such as chloride
(Cl-), nitrate (NO3-), bicarbonate (HCO3-), or sulfate (SO4--)]
may result from the dissociation of a salt, acid, or alkali.
Anion Exchange. Ion Exchange. A water conditioning process.
Antioxidants. Compounds that retard the rate of oxidation
of a polymer.
Anisotropic. Exhibiting different physical properties in different
directions.
Anisotropic Adhesive. Adhesive, Anisotropic
Annular Ring. The pad area that remains after a hole is drilled
through the pad.
ANSI. American National Standards Institute
Antistatic Materials resist turbocharging more than ?00 volts.
Anti-Pad. The area of copper etched away around a via or a
plated through-hole on a power or ground plane, thereby preventing
an electrical connection being made to that plane.
AOI. Automated Optical Inspection
Application-Specific Integrated Circuit (ASIC). An IC device
whose function is designed for a specific application(s).
Aperture. An opening in a stencil or screen.
Aperture, Chemical Etched. An opening in metal stencil created
by coating the metal foil with photoresist, exposing an image
both sides the resist using a phototool, and etching the foil
from both sides.
Aperture, Electroformed. An opening in stencil formed by imaging
a photoresist on a substrate and then plating the nickel foil
around the resist to the desired thickness.
Aperture, Electropolished. An electrolytic post-process that
"smooths" the walls of aperture walls to improve solder paste
printing.
Aperture Files. Precise x-y location and shape of all apertures
required on a printed circuit board.
Aperture, Laser Cut. An opening in a metal stencil created
by using Gerberâ and aperture
data to position a laser cutting head.
Aperture, Trapezoidal. An aperture with the board side opening
1 to 2 mils larger than the squeegee side opening.
API. Application Program Interface
Application Program Interface. The interface between the application's
software and the application platform.
Application Software. A program that performs a specific service
or solves a particular problem.
AQL. Acceptable Quality Level
Aqueous. A water soluble.
Aqueous Cleaning. Cleaning, Aqueous
Architecture. A structured set of protocols that implement
the functions of the system.
Array. A group of components arranged on rows and columns.
Artwork. A phototool used to create (1) features during printed
circuit board fabrication or (2) apertures on a screen or a
chem-etched stencil.
Artwork Generation. The process of transferring the CAD circuit
layout to reproducible artwork for use by stencil and printed
circuit board fabricators.
Artwork Master. Artwork used to produce production masters.
ASIC. Application Specific Integrated Circuit
ASME. American Society of Mechanical Engineers
Aspect Ratio. (1) Thickness of a printed circuit board to
the diameter of the smallest hole. (2) Thickness of a stencil
to the width of the smallest aperture.
Assembler. A program that translates mnemonics into binary
codes that run on a computer.
Assembly. A functional subdivision of a component, consisting
of parts or subassemblies that perform functions necessary for
the operation of the component as a whole. Examples: regulator
assembly, power amplifier assembly, gyro assembly, etc.
AST. Accelerated Stress Testing
ASTM. American Society for Testing and Materials
Asynchronous. An action that takes place at an arbitrary time,
without synchronization to a reference timer or clock.
ATE. Automatic (Automated) Test Equipment
Atm. Atmosphere pressure
Atomic Force Microscope (AFM). A microscope that works by
bringing a fine needle right up to the surface of a semiconductor
and tracing the topography of the material. AFMs are an alternative
to scanning electron microscopes as a means of measuring and
monitoring the widths and heights of critical dimensions on
an integrated circuit die.
Au. Chemical symbol for the element gold.
Automated Optical Inspection (AOI). A mechanized visual inspection
process.
AWG. American Wire Gage
Axial Lead. Lead wire extending from a component or module
body along its long axis.
Axial Leaded Components are usually cylindrical in shape and
have leads exiting from opposite ends along its long axis.
Azeotrope. A liquid mixture with a constant maximum or minimum
boiling point lower or higher than the boiling points of its
components and with the capacity to distill without change in
composition.
B-Stage Resin. An intermediate stage in curing a thermoset
resin. Prepreg
Back End Of The Line (BEOL). Test, assembly, and packaging
of wafer manufacturing.
Ball Bonding. Bonding, Ball
Ball Grid Array (BGA) is surface mount technology IC package
that provides electrical advantage of shorter signal and power
paths and the mechanical advantage of greater interconnects
and higher lead pitch, while decreasing package size.
Bare Board. An unpopulated printed circuit board.
Bare Die. An unpackaged integrated circuit.
Barrel. The cylinder formed in the drilled through hole in
a printed circuit board.
Base Board. Base Material
Base Material. In printed circuit board fabrication, the insulating
laminate where the conductor pattern is formed.
Batch. An entity that represents the production at any point
in the process. A batch is a running control recipe. The material
that is being produced or that has been produced by a single
execution of a recipe is also considered a batch.
Batch Control. Consists of a sequence of one or more steps
(phases) that must be performed in a defined order for a finite
period of time to process finite quantities of input material
to produce finished product.
Batch Manufacturing. Manufacturing in groups, lots or batches
in which each part or finished good is identical.
Batch Processing. The method adopted when the required product
volumes do not allow continuous production of one product on
particular machines.
BBA. Bus Ball Array
Bed-Of-Nails. A test fixture, used with (automated) test equipment,
made of spring loaded contact pins (Pogoâ pins) located to correspond with desired measurement
points (nodes) on a printed circuit board.
Bend Radius. The radius at the inside of the bend at (1) the
lead shoulder leading to the leg and (2) the base of the leg
leading to the foot.
BEOL. Back End Of The Line
BGA. Ball Grid Array
Bi. Chemical symbol for the element bismuth.
Bifurcated Terminal. Terminal, Bifurcated
Binder. Materials added to pastes and adhesives to provide
strength for handling purposes.
Binning. Classifying components by their performance at the
final test. The analogy is to physically drop things into different
bins.
Bipolar. (1) A signal that includes positive and negative
values. (2) A type of semiconductor.
Birdcage. A defect in stranded wire where the strands in the
stripped portion between the covering of an insulated conductor
and a soldered connection (or an end-tinned lead) have separated
from the normal lay of the strands.
BIST. Built-In Self Test
BIT. Built-In Test
Blind Via. Via, Blind
Blister. Raised areas on the surface of the laminate caused
by the pressure of volatile substances entrapped within the
laminate.
Blow Hole. A cavity in the solder surface whose opening has
an irregular and jagged form, without a smooth surface.
Bond Strength. The force per unit area required to separate
two adjacent layers of a package. The force is applied perpendicular
to the surface of the package.
Bonding. Joining of two materials.
Bonding Alloy. Solder
Bonding, Ball. A wire bonding method that melts a sphere of
gold wire, melts the sphere at the first connection point, draws
a loop in the wire, and makes a wedge bond at the other connection
point.
Bonding, Die. The attachment of an integrated circuit chip
to a substrate.
Bonding Pad. Pad. Termination
Bonding, Tape. Using a metal or plastic tape material to support
the carrier of a component in a gang bonding process.
Bonding, Thermocompression. Machines that use pressure and
heat in the absence of electrical current and without an intermediate
material to form wire bonds.
Bonding, Thermosonic. Machines that use heat (typically 150罜),
ultrasonic energy, force, and time to form wire bonds.
Bonding, Ultrasonic. Machines that use ultrasonic energy,
force, and time to form wire bonds.
Bonding, Wedge. A wire bonding method that can use either
gold or aluminum wire. Aluminum wedge bonds are made with ultrasonic
bonding machines. Gold wedge bonds are made using thermosonic
bonding machines.
Bonding, Wire. A die connect methodology that runs either
gold or aluminum wires between pads on the integrated circuit
to either a lead frame or pads on a printed circuit board. Ball
and wedge bonding are primary wire bonding methods, of which
ball bonding is more common.
Boundary Scan. A functional test designed into integrated
circuits.
Bow. A cupped variation from a known flatness of a printed
circuit board.
Breakaway Tabs. Excess material left on printed circuit boards
during fabrication to improve board handling that is removed
after assembly.
Breakout. Poor registration between the hole and the pad on
a printed circuit board to the degree that the hole is not within
the area of the pad.
Bridging. A buildup of solder between components, conductors,
and/or base substrate forming an undesired conductive path.
British Standards Institute (BSI). A standard setting organization.
BSI. British Standards Institute
Buffer. A solution that minimizes changes in hydrogen ion
concentration that would otherwise occur as a result of a chemical
reaction.
Built-In Self Test (BIST). Test, Built-In
Built-In Test (BIT). Test, Built-In
Bulk Components. Packaging with loose chip or MELF components
that with a special feeder present the parts the pick and place
head.
Bump. A small mound formed on the device or the substrate
pads that can be used as a contact for face-down bonding. This
is a method of providing connections to the terminal areas of
a device.
Buried Via. Via, Buried
Burn-In. An accelerated stress test run at elevated temperature
to weed-out marginal components.
C-Stage Resin. A resin in the final stage of curing.
CAD. Computer Aided Design
CAGR. Compound Annual Growth Rate
CAM. Computer Aided Manufacturing
Camera, Component. An upward looking camera used to determine
part position offsets required for proper placement.
Camera, Fiducial. A downward looking camera in the placement
head used to determine position of the printed circuit board
relative to the head. Or vice versa.
Canadian Standards Association (CSA). A Canadian safety standard
certification organization.
Capability. Process Capability
Capability Ratio. Cp
Capability Ratio, Centered. Cpk
Capacity Buy. Buying of equipment to increase manufacturing
capacity, as opposed to a technology buy.
Capillary Action. A flow of a fluid against gravity between
solid surfaces.
Card. Printed Circuit Board
Carrier Tape. Tape, Carrier
CASE (Tools). Computer-Aided Software Engineering.
Castellation. Metalized features that are recessed on the
edges of a chip carrier, which are used to interconnect conducting
surfaces or planes within a chip carrier or on the chip carrier.
Catalyst. A chemical that changes the rate of a chemical reaction.
Cation. A positively charged ion in an electrolyte solution,
attracted to the cathode under the influence of a difference
in electrical potential. Sodium ion (Na+) is a cation.
Cation Exchange. Ion Exchange. A water conditioning process,
commonly used for water softening.
Cation Exchange Resin. Cation exchanger. Base exchanger. An
ion exchange material possessing reverse exchange ability for
cations. Sulfonated polystyrene copolymer divinylbenzene (DVB)
exchange resin is used almost exclusively today in ion exchange
water softeners.
CBGA. Ceramic Ball Grid Array
Chip Carrier
CCGA. Ceramic Column Grid Array
Centered Capability Ratio. Cpk
Centering. Correcting the actual center of a part on a nozzle
after picking to the true center of the nozzle.
Centering, Mechanical. Repositioning a part on a nozzle after
it has been picked using spring-loaded jaws that close around
the part and move it to the proper position.
Centering, Vision. Using a camera to determine position offsets
to compensate for the location of the part on the nozzle.
Ceramic. An inorganic, nonmetallic material, such as alumina,
beryllia, steatite, or forsterite, which is fired at a high
temperature. Ceramics are used in electronics as a substrate
or to create component packages.
Ceramic Ball Grid Array (CBGA). A ball grid array (BGA) package
of cofired alumina ceramic substrate allowing various lid sealing
and encapsulation techniques.
Ceramic Column Grid Array (CCGA). A ceramic ball grid array
(CBGA) with solder columns replacing the solder balls.
Certification. The act of verifying and documenting that personnel
have completed required training and have demonstrated specified
proficiency and have met other specified requirements.
Chelating Agent. This agent forms a bond with the ions, such
as calcium and magnesium ions and prevents precipitation of
calcium and magnesium salts as hard water.
Chelation. The mechanism by which chemicals that would otherwise
precipitate are complexed in solution with a chelating agent.
Chemical Etched Aperture. Aperture, Chemical Etched.
Chemical Etched Stencil. Aperture, Chemical Etched.
Chemical Vapor Deposition (CVD). Deposition of thin films
(usually dielectrics/insulators) on silicon wafers by placing
the wafers in a mixture of gases which react at the surface
of the wafers.
Chem-Etched. Chemical(ly) Etched.
Chip. (1) Chip Component. (2) Integrated Circuit. (3) Bare
die.
Chip Carrier. A low profile four sided (rectangular) part
package, whose semiconductor chip cavity or mounting area is
a large fraction of the chip size.
Chip Component. A SMT passive device, including resistors,
capacitors, and inductors.
Chip On Board (COB). An unpackaged silicon die mounted directly
on the printed circuit board and connected with wire bonds.
Chip Scale Package. A popular description is that a CSP must
be no more than 120% the X and Y dimensions of the silicon die
within the package. So, the CSP is a die on a carrier substrate.
In order to maintain the CSP die to package ratio the CPS is
generally a ball grid array. So, this description becomes fuzzy
because CSP fabricators routinely shrink the die to reduce cost,
but generally do not change packaging.
Chip Shooter. A high speed surface mount component handler
and placer.
Chlorofluorocarbon (CFC). A chemical that was used in the
electronic, chemical, and refrigeration industries.
CIM. Computer Integrated Manufacturing
Circuit. Circuitry
Circuit Width. Conductor Width
Circuitry. The configuration or design of the conductive material
on the base material. This includes conductors, lands, and through
connections when these connections are an integral part of the
manufacturing process.
Circumferential Separation. A crack or void in the plating
extending around the entire circumference of a PTH, or in the
solder fillet around the conductor, in the solder fillet around
an eyelet, or at the interface between a solder fillet and a
land.
Clamshell (Fixture). A two sided test fixture that opens like
a book (clamshell) to accept the printed circuit board or assembly
for testing.
Class XXXX Clean Room. A clean room rating system. For instance,
a Class 100,000 Clean Room limits the particle count to less
than 3500 particles per liter (100,000 particles per cubic foot)
of a size of 0.5 micron or larger, or 25 particles per liter
(700 particles per cubic foot) of a size 5.0 microns or larger.
CLCC. Ceramic Leaded Chip Carrier
Clean Room. An enclosed room employing control over particulate
matter in the air with temperature, humidity, and pressure controls.
Cleaning. The process of removing flux residues and other
contaminants from the surface of a printed circuit assembly.
Cleaning, Aqueous. Cleaning parts with water (e.g., tap, pure,
or de-ionized) as the primary cleaning fluid.
Cleaning, Manual. Spot cleaning flux residues from assembly
surfaces, usually using a brush and isopropyl alcohol as the
cleaning agent or solvent.
Cleaning, Plasma. A bonding pad preparation process that uses
electrically excited gas molecules to remove surface contamination.
Cleaning, Semiaqueous. A cleaning process using a solvent
followed by a hot water rinse and drying.
Cleaning, Solvent. A cleaning process using chlorinated and
fluorinated hydrocarbon liquids.
Cleaning, Ultrasonic. A cleaning process using ultrasonic
energy (mechanical oscillation ) along with a chemical solvent.
Cleaning, Vapor Degreaser. A cleaning process where a heated
solvent is condensed on the printed circuit board to be cleaned.
Client. A software application which communicates with another
software application (the server). The server normally supplies
data or functions to the client.
Clinched Lead. A pin through hole lead that is bent on the
solder side of the printed circuit board to hold the component
in place prior to soldering.
Contract Manufacturing (Manufacturer)
CMOS. Complementary Metal Oxide Semiconductor
CMS. Contract Manufacturing Services
Coating. A thin layer of conductive or dielectric material
applied over components or a base material.
COB. Chip On Board
Cohesive Failure occurs when internal strength of the adhesive
is not as great as the forces applied to it. Adhesive remains
bonded to both substrates.
Coefficient of Thermal Expansion (CTE). The ratio of change
in dimension per unit change in temperature.
Cofire. A process for forming multilayer ceramic substrates
in which thick-film conductors and dielectrics are simultaneously
processed by a firing cycle.
Cold Flow. Movement of insulation (e.g. Teflon) caused by
pressure. Creep.
Cold-Junction Compensation. An artificial reference level
that compensates for ambient temperature variations in thermocouple
circuits.
Cold Solder Joint. Solder Joint, Cold
Colloid. A substance that remains suspended in a solution
or fails to settle out of solution.
Column Grid Array (CGA). A packaging technology similar to
a pin grid array, in which a device's external connections are
arranged as an array of conducting pins on the base of the package.
However, in the case of a column grid array, small columns of
solder are attached to the conducting pads.
Comb Pattern. Two sets of interconnected interspaced finger-like
arrays of uniformly spaced conductors. SIR testing requires
comb patterns on printed circuit boards.
Combinational Testing. Test, Combinational
Compiler. A program that translates high-level-language statements
into codes that a computer can execute.
Component. (1) A functional subdivision of a system, generally
a self-contained combination of assemblies performing a function
necessary for the system's operation. Examples: power supply,
transmitter, gyro package, etc. (2) A part of an assembly or
subassembly. A part.
Component Camera. Camera, Component
Component Hole. Plated-Through-Hole (PTH)
Component Lead. A wire or formed conductor extending from
a component and serving as a mechanical and/or electrical connection.
Component-Level Repair. Repair, Component-Level
Component Side. Primary side
Composite. A resin combined with another material, such as
glass fiber, to improve physical properties.
Computer Aided Design (CAM). A design method that uses computer
generated images, rather than mechanical drawings.
Computer-Aided Software Engineering (CASE) Tools allow users
to make changes in the way they access information from a relational
data base.
Computer Integrated Manufacturing (CIM). Linking computer
aided design data to the computer controlled assembly and test
equipment used to produce the product.
Conductive Adhesive. Adhesive, Conductive
Conductive Material. Electrostatic Conductive Material
Conduction (Soldering). Soldering, Conduction
Conductor. A lead, solid or stranded, or printed wiring path
serving as an electrical connection.
Conductor Spacing. The distance between traces on a printed
circuit board.
Conductor, Thermal. Thermal Conductor
Conductor Thickness. The thickness of the conductor including
all metallic coatings, excluding non-conductive protective coating.
Conductor Width. The observable width of a circuit or conductor
at any point chosen at random. The width is measured from directly
above.
Conformal Coating. A thin electrically nonconductive protective
coating that conforms to the configuration of the covered assembly
to provide environmental and mechanical protection.
Conformity. The ability to satisfy specified requirements.
Connection. An electrical termination that was soldered. A
solder joint.
Connection, Interlayer. An electrical connection between conductive
patterns in different layers of a printed circuit board. Via
Construction Analysis. Destructive Physical Analysis (DPA).
The process of destructively disassembling, testing, and inspecting
a device for the purpose of determining conformance with applicable
design, process, and workmanship requirements.
Contact Angle. Wetting angle. The angle of wetting between
a solder fillet and the pad or component lead. A small contact
angle indicates good wetting, and a large angle indicates poor
wetting.
Contact Resistance. The maximum resistance allowed between
a pin and the socket contacts of a connector when assembled
and in use.
Contaminant. An impurity or foreign substance present in a
material that affects one or more properties of the material.
A contaminant may be or not be ionic.
Control Chart. A chart for tracking a series of measurements
taken over time.
Control System. A system to guide or manipulate various elements
in order to achieve a prescribed result.
Convection. Transfer of energy (heat) by the circulation of
a fluid or gas.
Conveyor. A machine that supports a printed circuit board
and moves it from one location to another.
COO. Cost Of Ownership
Coplanarity. The vertical spread in the measurement of the
lowest and highest contact ("out-of-line") of a package.
Copper Tin Intermetalic. Intermetalic, Tin Copper
Core Material. In printed circuit board fabrication, fully
cured inner layers of a multilayer printed circuit board.
Core Solder. Solder, Wire/Core
Corrosion. The chemical reaction of a metal in contact with
the air.
COTS. Commercial Off The Shelf
Coupon. A portion of a printed circuit board used for testing.
Court Yard. The keepout area of a surface mount component.
Cover Tape. Tape, Cover
Cp. Capability Ratio. Measurement of the width of the distribution
of process measurements, compared to a desired point.
Cpk. Centered Capability Ratio. Measurement of the mean of
process measurements, compared to a desired point.
Crazing. An internal condition occurring in the laminate base
material in which the glass fibers are separated from the resin,
caused by mechanical stress.
Creep. Cold Flow
Critical Dimension (CD). The minimum width that is allowed
as part of the circuit design, on any given patterning layer.
Critical Path Method. A technique to determine the order in
which operations must be executed to complete a project in minimum
time, and determine which operations have some "float" or capacity
to be rescheduled without affecting the minimum time.
CRT. Cathode Ray Tube
Crystallinity. A state of molecular structure in some polymers
denoting uniformity and compactness of the molecular chains.
CSA. Canadian Standards Association
CSP. Chip Scale Package
CSP-C. Ceramic Chip-Scale Package
CSP-L. Laminate Chip-Scale Package
CTE. Coefficient of Thermal Expansion
CTE Mismatch. The difference in the CTE of two materials or
components joined together. This mismatch can produce strains
and stresses at joining interfaces or in attachment surfaces.
Cu. Chemical symbol for the element copper.
Cup Terminal. Terminal, Cup
Cure. A heat, catalyst, or pressure activated chemical reaction
that changes the physical properties of a material.
Curing Cycle. The time-temperature profile needed to cure
a thermosetting material like a bonding adhesive.
Curing Time. The time needed to cure a thermosetting plastic
material.
Data Acquisition System. Any device that acquires information
from sensors using amplifiers, multiplexers, and analog to digital
converters.
DCA. Direct Chip Attach
DCS. Distributed Control System
DDA. Direct Die Attach
DDE. Dynamic Data Exchange
Defect. Any nonconformance to specified requirements by a
unit or product.
Definition. Degree that a produced pattern matches the master
pattern.
Defluxing. Cleaning. Removing flux residues after a soldering
operation.
Degradation. Destructive change in the chemical structure
of a plastic reflected in its appearance or physical properties.
Degreasing. Cleaning. Removing wave oil and flux residues
after a soldering operation.
Deionized (DI) Water. A pure form of water with no ionized
material.
Delamination. A separation of the bonded layers or foils of
a laminated material, such as a printed circuit board.
Dendrite. Metallic filaments growing by electromigration between
two points.
Density. The weight of a material in relationship to its volume.
Deposition. The process of applying a material on a substrate
by applying pressure through a screen or stencil.
Desiccant. A substance, such as calcium oxide or silica gel,
with a high attraction for water and is used as a drying agent.
Desiccant Cabinet. A nitrogen atmosphere storage area for
moisture sensitive parts.
Design Of Experiments (DOE). A statistical technique for determining
the relationship between and relative importance of various
factors controlling a process.
Design Rules. Allowable dimensions, keepout areas, and tolerances
used in the layout and design of circuitry.
Desoldering. A disassembly method of removing the solder from
components on a printed circuit board.
Detergent. A product designed to make materials, often oils
and greases, soluble in water. Usually, detergents are made
from synthetic surfactants.
Deviation. A specific authorization, granted before the fact,
to depart from a particular requirement of specifications or
related documents.
Device. Component
Dewetting. The condition in the solder joint in which the
liquid solder has not adhered intimately with one or more the
components. Characterized by an abrupt boundary between the
solder and the component lead or conductor. Can be distinguished
by a "rolling back" of the solder from the lead or conductor.
DFA. Design For Assembly
DFT. Design For Test
DI (Water). Deionized water.
Diazo. A type of artwork film.
Die. Integrated circuit chip as diced or cut from the finished
wafer.
Die Attach. Bonding a die to its mount in its package. This
is often done with a metal based glue-like silver epoxy for
good conduction of heat away from the chip.
Die Bonding. Bonding, Die
Dielectric. Nonconducting material used to encapsulate circuitry
and in the manufacture of capacitors and printed circuit boards.
Dielectric Constant. That property of a dielectric which determines
the electrostatic energy per unit volume for unit potential
grade.
Dielectric Strength. The voltage at which an insulating material
can withstand before breaking down occurs, usually expressed
as volts per mil.
DIP. Dual Inline Package
Diffusion. A material transport phenomena that occurs in solids,
and is caused by the continual physical motion of atoms from
one position to another. This results in the flow of material
from regions of high concentration to regions of low concentration.
Digital. A type of circuit in which the signals can have only
one of two possible states, a "1" or a "0".
Digital-To-Analog Converter (DAC or D/A Converter). A device
that converts digital information into a corresponding analog
voltage or current.
Dikes. Side Cutter
Direct Chip Attach (DCA). Chip-on-board technology.
Direct Die Attach (DDA). Direct Chip Attach
Direct Memory Access (DMA). The direct transfer of information
between a computer's memory and a device while the computer's
CPU does something else.
Discrete Components. Individual resistors, capacitors, diodes
etc.
Dispense (ing). A machine or manual method of applying solder
paste, adhesives, and other gels using air or mechanical pressure
to force the material being dispensed through a nozzle or tip
onto a substrate.
Dispersants. Organic and inorganic phosphates and polymers
used in aqueous cleaning to assist in the removal of insoluble
materials.
Dissipation Factor. The tangent of the loss angle of the insulating
material.
Dissipative Material. Electrostatic Dissipative Material
Dissociation. The separation of an electrolyte into ions of
opposite charge.
Distributed Control System (DCS). A real-time control system
for continuous and batch process applications.
Distributed Processing. The physical and/or logical connectivity
of hardware, software, information and load sharing.
Disturbed Solder Joint. Solder Joint, Disturbed
Divinylbenzene (DVB). A widely used cation exchange resin.
Document Management System. Provides storage, retrieval and
manipulation of documents in a compact space.
DOE. Design Of Experiments
Double-Sided Assembly. A printed circuit assembly with components
on both sides of the substrate.
DPA. Destructive Physical Analysis or Construction Analysis
DPM. Defects Per Million (opportunities)
DRAM. Dynamic Random Access Memory
Draw Bridge. Tomb Stone
Drill Files. Precise x-y location and sizes of all holes required
on a printed circuit board.
Drill Wander. In printed circuit board fabrication, deviation
from the target drilling location.
Dry Etching. Plasma Etching
Dry Run (ning). Operating a machine without processing. For
instance, dry running a placement machine sequentially moves
the head to the feeders and the component placement locations.
Dross. Chiefly tin oxide, but contains oxidized lead and other
contaminants that form on the surface of molten solder.
Dross Content. A measure of the cleanliness of solder powder.
DSP. Digital Signal Processor
Dual Inline Package (DIP). A PTH package with two parallel
rows of leads extending from the base of the component. Standard
lead pitch is 0.100 inch.
Dry Film (Solder Mask). Solder Mask, Dry Film
Dual Gantry. A machine positioning system with two independent
gantries.
Dual Wave Soldering. Soldering, Dual Wave
Dummy Component. A non-functional component package.
Dummy Land. A conductor on a printed circuit board that is
not connected electrically to other circuitry.
Dummy Pad. Pad, Dummy
Durometer. A measure of the hardness of a non-metal.
DVB. Divinylbenzene
Dynamic Data Exchange. DDE is a communication protocol that
allows Windows® programs to communicate with each other.
Edge Connector. The portion of the PCB used to provide external
electrical connection.
Edge Clearance. A keepout area on the side and each ends of
printed circuit boards required for board handling.
EDS. Energy Dispersive Spectrograph
EIA. Electronic Industries Association
EIAJ. Electronic Industries Association of Japan
Elastomeric. A material that at room temperature can be stretched
repeatedly to at least twice its original length, and upon release
of the stress, will return with force to its approximate original
length. Rubber band material is elastomeric.
Electrochemical Migration. An unplanned electrolytic plating
process. A film of polar solvent, often water, on a substrate
surface provides for current flow between points with a difference
in electrical potential.
Electrode. A conductor through which a current enters or leaves
an electrolytic cell, vacuum tube, or any nonmetallic conductor.
Electroformed Aperture. Aperture, Electroformed
Electroformed Stencil. Stencil, Electroformed
Electroless Nickel - Immersion Gold. A coating applied during
printed circuit board fabrication to protect copper features
from oxidation.
Electroless Plating. Plating, Electroless
Electrolyte. Compounds that conduct an electric current by
the movement of ions.
Electrolytic Corrosion. Corrosion by means of electrochemical
action.
Electrolytic Plating. Plating, Electrolytic
Electromagnetic Compatibility (EMC). (1) The ability of electronic
equipment to operate in an intended electromagnetic environment
without degradation caused by interference. (2) The ability
of equipment to operate in its electromagnetic environment without
creating interference with other equipment.
Electrostatic Conductive Material. Material with a surface
resistivity of 10 ohms per square maximum.
Electrostatic Discharge (ESD). The transfer of a charge when
the two objects have different electrostatic potentials. The
potentials can be caused by either direct contact or induced
by an electrostatic field. In electronic manufacturing, the
employee working on a printed circuit board and a component
on the same board can have different electrostatic potentials,
which will damage electronic components.
Electrostatic Dissipative Material. Materials with a surface
resistivity greater than 10^5, but less than 10^12 ohms per
square.
Electrostatic Field. A voltage gradient between an electro-statically
charged surface and another surface of a different electrostatic
potential.
Electrostatic Insulating Material. Materials with a surface
resistivity greater than 10^12 ohms per square.
Elevator, Tray. Feeder, Tray
Elongation. The fractional increase in length of a material
stressed in tension.
Embossed Tape. Tape, Embossed
EMC. Electromagnetic Compatibility
EMI. Electromagnetic Interference
EMS. Electronic Manufacturing Services
Emulsifier. An aqueous additive used to keep soils dispersed
throughout the cleaning fluid.
Emulsion. A material that suppliers build-up on a printing
screen to block portions of the screen. The un-blocked (open)
portion of the screen define the pattern for depositing solder
paste on the printed circuit board.
Encapsulating. Potting. Enclosing an article in an envelope
of adhesive.
Encapsulating Compound. An electrically nonconductive compound
used to completely enclose and fill in voids between electrical
components or parts.
Encoder. A precision glass or metal ruler mounted on the frame
of a machine that is used to measure the location of a moveable
head. Encoders can be either linear or rotary.
ENIG. Electroless Nickel - Immersion Gold
Enterprise Resource Planning (ERP). A logistical extension
of MRP.
EPBGA. Enhanced Plastic Ball Grid Array
Epoxy. A polymer thermosetting resin used to bond materials.
Epoxy Resin. A material that forms straight chain thermoplastic
and thermosetting resins. Epoxy resins have excellent mechanical
properties and good dimensional stability.
EPROM. Electronic Programmable Read Only Memory
ERP. Enterprise Resource Planning
ESD. Electrostatic Discharge
ESD Sensitive. Electrical and electronic parts, assemblies
and equipment that could be damaged by ESD voltages.
ESDS. Electrostatic Discharge Sensitive
Etch Factor. The ratio of etch depth to the amount the resist
is undercut during etching.
Etching. The process of selectively removing any material
not protected by a resist using an appropriate solvent or acid.
Ethyline Vinyl Acetate Resins (EVA). Co-polymers of the polyolefins
family derived from random co-polymerization of acetate and
ethylene.
Eutectic. An alloy with a lower melting point lower than the
melting points of its components. 63% tin and 37% lead (63Sn/37Pb)
solder is referred to as eutectic solder. Eutectics change directly
from liquid to solid, and the reverse, with no intermediate
plastic states.
EVA. Ethyline Vinyl Acetate Resins.
Event Counter. A circuit that counts the occurrences of a
certain condition.
Excessive Solder Joint. Solder Joint, Excessive
Excellon® Files. Drill files
Excising. Cutting component leads free from the remainder
of the package to prepare the component for forming or placement.
Expert System. Software that applies knowledge and reasoning
techniques that involve rules and heuristics to solve problems
normally requiring the abilities of human experts.
Exudation. Migration of adhesives from the interior to the
surface of plastic.
Eyelet. A hollow tube inserted in a terminal or printed circuit
board to provide mechanical support for component leads or for
electrical connection.
Fab. Fabrication. A "fab" can refer to either the fabricator
or the printed circuit board made by the fabricator.
Failure. The temporary or permanent functional impairment
of a component or device caused by physical, mechanical, chemical,
or electrical damage.
Failure Mode Effect Analysis (FMEA). A structured evaluation
of the impact of a failure on product or process functionality,
safety, usability, maintainability, availability, and testability.
Fault Tolerance. The ability to execute tasks regardless of
the failure of strategic components.
FBGA. Fine-pitched BGA
FBGA flange package. Fixed body size CSP. A substrate that
extends beyond the boundaries of the die. The package retains
its board footprint, regardless of die size.
FBGA real chip size. CSP in which the package dimension is
closely related to the die size. The package shrinks every time
there is a die shrink.
FESEM. Field Emission Scanning Electron Microscope
FIB. Focused Ion Beam
Field Emission Scanning Electron Microscope (FESEM). A conventional
SEM, except that a cold field emission electron source is used,
providing higher image resolution, increased signal to noise
ratio, and increased depth of field.
File Transfer Protocol (FTP). A protocol that transfers files
over the Internet.
"Flash" Plating. Electroless Plating
Flatpack. A part with two straight rows of leads (normally
on 0.050 inch centers) that are parallel to the part body.
Fluorescence. The process by which incident electromagnetic
radiation induces atomic ionization. As a result of ionization,
electrons from higher level orbitals drop (cascade) to lower
orbitals, and energy is released by the atom in the form of
X-ray photons.
Feature. A conductive pattern on the printed circuit board.
Feeder. A machine that supplies tape and reel components in
the proper orientation and sequence for picking by a pick and
place head.
Feeder, Intelligent. A feeder with a control system intended
to reduce set-up and inventory control errors.
Feeder, Tray. A machine that supplies tray components in the
proper orientation and sequence to a pick and place head.
FEP. Fluorinated Ethylene Propylene
FIB. Focused Ion Beam
Fid. Fiducial
Fiducial. A feature of the printed circuit board used to provide
a common measurement point for all steps in the assembly process.
Fiducial Camera. Camera, Fiducial
Fiducial, Global. A fiducial mark used to locate the position
of all circuit features on a printed circuit board.
Fiducial, Local. A fiducial mark used to locate an individual
component.
Fillet. A build-up of material between two surfaces. In reference
to soldering, a fillet is the solder built-up between the component
and the conductor. Ideally, the fillet is smooth and concave.
Film Tension. The greatest longitudinal stress a film can
bear without tearing apart.
Fine Pitch (1) In SMD: Surface mounted components with a lead
or termination pitch of 0.025 (some say 0.020) inch or less.
(2) In BGA: With standard pitch is 1.27 (some say 1.0) mm, anything
less requires special handling. (3) The pitch that is difficult
to place (requires a cost adder) in manufacturing (assembly)
practice.
Firmware. A program permanently recorded in ROM; it is effectively
a piece of hardware that performs software functions.
First Pass Yield. The percent of finished assemblies not requiring
rework.
Flat Pack. An integrated circuit package with leads on two
or four sides with either gull wing or flat leads.
Flat Wave. Laminar Wave
Flex. Flexible Printed Circuit Board
Flexible Printed Circuit Board. A printed circuit board laminate
made dielectric polymer film, adhesive, and conductive foil.
Flip Chip. A COB technology that has bumps attached to the
silicon die, is flipped, and mounted directly to a printed circuit
board.
Flood Bar. A device on a screen printer that drags the paste
back to the starting point after the squeegee has made a stroke
to prepare for the next stroke.
Flux. A chemically-active compound which, when heated, removes
minor surface oxidation, minimizes oxidation of the basis metal,
and promotes the formation of an intermetallic layer between
solder and basis metal. Various flux types include: low residue,
organic acid, rosin, rosin activated, rosin mildly activated.
Flux Activation Temperature. The temperature at which flux
is active enough to remove oxides from the metals being joined.
Flux Activity. The ability of materials (activators) in the
flux to remove corrosion and make the surface solderable.
Flux, Inorganic. An aqueous flux solution of inorganic acids,
such as hydrochloric or phosphoric, and halides. These fluxes
are very corrosive and not recommended for electronic assembly.
Flux, Low Residue. No-clean flux. "Leave on" flux. Low residue
fluxes usually have lower solids content (less than 5%) than
high-solids rosin fluxes. Their primary activator materials
are weak organic acids (adipic or succinic acid). No clean residues
are benign on a board surface and act as electrical insulators.
These fluxes can be either solvent (usually isopropanol) borne
or water borne in the case of volatile organic compound (VOC)
free no clean fluxes.
Flux, No-clean. Flux, Low Residue
Flux, Organic Acid (Type OA). Water Soluble Flux. Organic
acid fluxes have active ingredients such as organic hydrohalides,
amines, and amides. These fluxes are water soluble since they
contain no rosin. Good cleaning is critical with these flux
types since their residues are corrosive and electrically conductive.
Flux, Resin. A flux primarily is composed of natural resins
other than rosin types and/or synthetic resins.
Flux, Rosin (Type R). Typically, these fluxes are made up
of 60% solvent and 40% solids. This flux type謘 peak capability
is around 262罜 (500罠). At this temperature, rosin begins decomposing
into reducing gases. Above 346罜 (650罠), the flux becomes inactive
and polymerizes.
Flux, Rosin Activated (Type RA). Rosin activated flux typically
contains 1% to 5% activators. RA flux is used in applications
when RMA is not strong enough. For military purposes, RA flux
use usually is limited to component tinning of sealed devices
and solid wire. When warm, these fluxes can conduct electricity
and can leave residues that can cause corrosion or shorting
path formation between conductors.
Flux, Rosin Mildly Activated (Type RMA). When solder surfaces
require a more active flux than rosin flux, flux manufacturers
add chemical compounds called activators to the rosin. RMA flux
may contain a variety of activators in amounts less than 1%.
Limits are placed on their electrical and chemical properties
before and after soldering
Flux, Water Soluble. Flux, Organic Acid
Fluxer. The section of a wave solder machine that applies
flux to a printed circuit assembly. Foam, spray, and wave fluxers
are common.
Fluxer, Foam. Equipment for applying flux by bringing printed
circuit assemblies in contact with the surface of a foam head
of flux created by bubbling flux through a porous material.
Fluxer, Spray. Equipment for applying flux to a printed circuit
board by passing the board over a fine mist of flux created
by spray nozzles or ultrasonic transducers.
Fluxer, Wave. Equipment for applying flux by bringing printed
circuit assemblies in contact with the surface of continuously
flowing and circulating flux.
Fluxing. Using a fluxer. Applying flux.
FMEA. Failure Mode Effect Analysis
Foam Fluxer (ing). Fluxer, Foam
Focused Ion Beam (FIB). A "milling machine" that uses ions.
Like a SEM, a sample is put in a chamber under vacuum, beneath
a column which scans a focused beam of charged particles over
the sample surface. In a FIB, the charged particles are ions
(typically gallium) generated by a liquid metal source. The
ions collide with and sputter away atoms of the sample in the
scanned region. This beam can slice into the sample with great
accuracy. Like in an SEM, a detector in the chamber collects
secondary species (ion or electron) for imaging. Resolution
is fine enough to image ICs.
Foot Angle. The angle of the lead foot after lead forming
relative to the surface of the bottom of the component.
Foot Length. The part of the component lead that contacts
the bonding pad on the substrate.
Footprint. (1) The area occupied by a device mounted on a
substrate. (2) The area a machine takes up in a production area.
Fourth-Generation Environment (4GE). Fourth-Generation Language
Fourth-Generation Language (4GL). A computer language instructing
the computer at a higher-level language abstraction than traditional
high-level programming languages. Any computer language that
does not require traditional input/process/output logic falls
into this category.
FPT. Fine Pitch Technology.
Fractured Solder Joint. Solder Joint, Fractured
Frame. In inspection, the total area of the picture that is
scanned by a camera.
Frame Grabber. A device that digitizes an image and stores
it in a computer's memory.
Frame Rate. The frequency at which an image is completely
updated on a display monitor.
Frame Relay. A technology for transmitting data packets in
high-speed bursts across a digital network.
Freeze (ing). Solidification of a solder joint.
FR-4. A relatively inexpensive glass epoxy substrate.
FTP. File Transfer Protocol
Functional Test. Test, Functional
Fuzzy Logic. A method used to model linguistic expressions
that have non-binary truth values such as PID algorithms in
process control.
Gantry. A mount for moving a pick and place, inspection, or
dispense head in the x-y direction on a frame.
Gauge R&R. A statistical measurement technique that calculates
the inaccuracy of a measurement device according to gauge repeatability
and gauge reproducibility.
Gauge Repeatability. Equipment variation. The variability
of a gauge when used to make repeated measurements under carefully
controlled conditions.
Gauge Reproducibility. Appraiser variation. A statement of
gauge precision when used by different operators.
GelPak. A matrix tray style feeder without pockets, that consists
of a tacky gel over a mesh. The components are placed in a regular
array on the tray and are held in place by the tacky gel. When
picking components, vacuum is applied through the bottom of
the tray, pulling the gel through the mesh and releasing the
die.
GEM. General Equipment Module
General Equipment Module (GEM). A protocol for communicating
between production equipment.
Gerber® Data. Used in directing a photoplotter during
printed circuit board artwork fabrication.
GHz. Gigahertz
Glass Fabric. Glass yarns woven in a specific pattern.
Glass Transition Temperature (Tg). The temperature when a
material changes from hard, brittle, and glasslike to soft and
rubbery and looses considerable mechanical strength.
Global Fiducial. Fiducial, Global
Globtop. Encapsulant
Gold Flash. An extremely thin layer of gold with a thickness
measured on the molecular level which is either electroplated
or chemically plated onto a surface.
Golden Board. A known good printed circuit board used for
evaluating other printed circuit boards or assemblies.
Green Strength. The holding power of a paste or adhesive before
it is set or cured.
Ground. A mass such as earth, a ship, or a vehicle hull, capable
of supplying or accepting a large electrical charge.
Ground, Hard. A connection to "green wire" electrical ground
either directly or through low impedance.
Ground Plane. A relatively large mass of metal on a printed
circuit board used as an electrical ground or shield.
Ground, Soft. A connection to ground through an impedance
sufficiently high to limit current flow to safe levels for personnel
(normally 5 milliamperes). Impedance needed for a soft ground
is dependent upon the voltage levels which could be contacted
by personnel near the ground.
Gull Wing. Component leads that flare outward from the part
body.
Halide. A compound of chlorine, bromine, or iodine, often
added to flux as activators. Halides can form corrosive solutions.
Halide Content. The ratio of free chlorine and bromine ions
to solids in a flux.
Haloing. Mechanically-induced fracturing or delaminating on
or below the surface of the base printed circuit board material;
it is usually exhibited by a light area around holes, other
machined areas, or both.
Hard Ground. Ground, Hard
Hardner. The part that makes a thermosetting polymer cure.
HASL. Hot Air Solder Leveled
HASS. Highly Accelerated Stress Screening
HAST. Highly Accelerated Stress Testing
HDI. High-Density Interconnect
Head. An element of a pick and place machine that positions
(i.e., rotates, feeds-back x-y location, and moves on z axis)
nozzles to pick and place components.
Head, Self-Planarizing. A mechanism integrated into the head
of an outer lead bonder that allows the bottom surface of the
thermode blades to adjust to the plane defined by the surface
of the substrate.
Heat Resistance. The temperature at which a bond subjected
to a load fails.
Hermetic. The sealing of an object so it is airtight.
HFC. Hydrofluorocarbons
HFE. Hydrofluoroethers
Hipot. An electrical test to measure the voltage breakdown
of a substrate or material.
High Temperature Solder. Solder, High Temperature
Home Plate. A five sided, two dimensional, closed shape where
three equal length sides form a cube with one side removed and
two additional equal length sides that form interior angles
of 135? 90? and 135? A picture is worth a thousand words.
Hook Terminal. Terminal, Hook
Hot Air Solder Leveled (HASL). A printed circuit board fabrication
process that applies an oxidation preventing solder coating
to copper pads on the printed circuit board. Solder Leveling.
Hot Bar Soldering. Soldering, Hot Bar
Hot Tack. The ability of hot melts to have holding power even
while in the liquid hot state.
HTTP. Hypertext Transfer Protocol
Hybrid. A package where integrated circuits and discrete components
are attached directly to a common substrate. Connections between
the components are formed on the surface of the substrate and
some components such as resistors and inductors may be fabricated
directly onto the substrate.
Hydrolysis. Decomposition of a substrate by reaction with
water.
Hydrophilic Solvent. Polar Solvent
Hydrophobic Solvent. Non-Polar Solvent
Hydroscopic. The capacity of a material to absorb and retain
moisture from the ambient air.
Hypertext Transfer Protocol (HTTP). The protocol that negotiates
document delivery to a Web browser from a Web server.
Injection Molded Boards. Printed circuit boards made by molding
filler-reinforced resins into a desired shape. Routing and through
hole metallizations are performed by seeding and plating, or
by printing. An alternative approach is to transfer mold the
interconnect directly onto the injection molded cards.
Inner Layer. Internal Layer
Inorganic. Compounds without carbon.
Inorganic Flux. Flux, Inorganic
Inorganic Substrate. Substrate, Inorganic
Institute For Interconnecting And Packaging Electronic Circuits
(IPC). A research and standard setting organization focused
on fabricating and assembling printed circuit boards.
Insulation. (1) A non-conductor used to isolate or prevent
contact between conductors. (2) Electrostatic Insulating Material.
Integrated Circuit (IC). A microcircuit that consists of interconnected
elements on a single substrate, usually silicon, to perform
an electronic circuit function.
Integration. The state in which all aspects of plant-wide
operations are tied together in a continuous loop of information.
Intelligent Feeder. Feeder, Intelligent
Interconnect. Wiring patterned in integrated circuits or printed
circuit board to connect different devices together.
Interlayer Connection. Connection, Interlayer. Via
Intermetalic Layer (IL). A compound formed at the interface
of two different metals.
Intermetalic, Tin Copper. When joining 63Sn/37Pb and other
high tin alloys with copper, two intermetallic compounds are
formed. On the copper side is Cu3Sn and on the solder side,
the relatively rough and irregular Cu6Sn5. The total thickness
of the IL is usually 0.5-0.7 苖. The intermetallic compounds
of copper and tin form crystalline grains, the structure of
which is determined by the length and intensity of the thermal
interaction. Short reaction times form fine equiaxed grains,
which promote good solderability and solder joint strength.
Long reaction times result in coarse grains, and a thick IL.
A thick IL gives poor solderability and poor joint strength,
both in t = o shear and long-term reliability. The thickness
of the IL depends on the temperature, but will continue to grow
even at ambient temperatures (which on the absolute (罧) scale
approaches 60% of the liquidous temperature of 63Sn/37Pb solder).
This becomes important when parts or boards are solder coated
or pre-tinned. During prolonged or improper storage, the IL
can grow through the surface, affecting solderability.
Internal Layer. A conductive pattern that is contained entirely
within a multilayer PCB.
International Organization For Standardization (ISO). An international
standard setting organization based in Geneva, Switzerland.
Intrusive Soldering. Pin & paste
Invar. An alloy similar to bronze.
Inventory Management. The systematic determination of items
and quantities to be ordered; the coordination of order release
and order due dates; changes in the required quantities; and
the rescheduling of planned orders.
In-Circuit Test (ICT). Test, In-Circuit
Ion. A particle formed when an electron is added to, or subtracted
from, a neutral atom or group of atoms.
Ion Exchange. A reversible chemical process in which ions
from an insoluble permanent solid medium, the "ion exchanger"
(usually a resin) are exchanged for ions in a solution or fluid
mixture surrounding the insoluble medium. The superficial physical
structure of the ion exchanger is not affected. The direction
of the exchange depends upon the selective attraction of the
ion exchanger resin for the certain ions present and the concentrations
of the ions in the solution.
Ion Implantation. The process by which dopants (i.e., phosphorus,
arsenic, or boron) are introduced in exact quantities into silicon.
A stream of ions of the dopants is created and then directed
at a silicon wafer at a precisely controlled velocity (energy),
controlling both the concentration and depth of the dopant.
Ionic Contaminant. An ionic, or polar compound that forms
free ions when dissolved in water, making the water a more conductive
path. Process residue such as flux activators, finger prints,
and etching or plating salts usually contain ionic contaminants.
Ionograph®. A brand name for an instrument used to measure
ionic contamination (residues) on a printed circuit board.
IPA. Isopropyl alcohol
IR. (1) Infrared. (2) Insulation Resistance
IR Reflow. InfraRed Reflow. Reflow Soldering, Infrared (IR)
Iron. A soldering iron is a hand soldering tool.
ISO. International Organization For Standardization
ISO 9000 The "Quality SystemManagement Standard"
that specifies the elements of a quality system.
ISO 14000 The "EnvironmentalManagement Standard"
that specifies the elements of a environmental control system.
Isopropanol. Isopropyl alcohol
Isotropic. Having properties that have equal value in all
directions.
ITRI. Interconnection Technology Research Institute
Kapton ® A brand name of a polyimide film used as an electrical
insulation material with good thermal, mechanical, chemical,
and electrical properties.
Keepouts. Areas that are kept clear of any components.
keV. Kilo Electron Volts
KGB. Known Good Die
Known Good Board. Golden board.
Known Good Die (KGD). A die tested to meet requirements.
Laminar Wave. A section of a dual wave soldering machine used
to solder through hole components and remove shorts on SMT components.
Laminate. A product made of two or more layers of materials.
Lamination. C-stage. A heat and pressure process used to consolidate
a stack of prepregs into a solid block. The term also refers
to the consolidation of a stack of laminates (with circuitry)
to form a printed circuit board.
Land. A pad.
Land, Lifted. Pad, Lifted.
Land Pattern. A combination of conductive patterns intended
for the mounting interconnection and testing of a particular
component.
Lateral Edge. The longer side of a rectangular pad or printed
circuit board.
Laser. Light Amplification by Stimulated Emission of Radiation
Laser Cut Aperture. Aperture, Laser Cut
Laser Cut Stencil. Stencil, Laser Cut
Laser Soldering. Soldering, Laser
Lay-Up. In printed circuit board fabrication, stacking and
registering the layers of a multilayer printed circuit board.
LCC. Leadless Chip Carrier
LCCC. Leadless Ceramic Chip Carrier
Leaching. Dissolution of a metal coating into liquid solder.
Nickel barrier under-plating prevents the over-plating (usually
gold or silver) from leaching into the copper base.
Lead Forming. Shaping the lead into a specific shape or profile
required for placement or insertion and bonding.
Lead Frame. A sheet metal frame containing leads and a base
to which an integrated circuit is attached before packaging.
Lead Free Solder. An alloy of tin and another metal such as
antimony, bismuth, copper, magnesium, silver, zinc, or bismuth.
Lead, Part. The solid conductor attached to a part.
Lead Pitch. Pitch
Lead Plating. Plating, Lead
Lead Spacing. Pitch. The distance between the center of adjacent
leads.
Leaded Device. Electronic device with electrical leads extending
from the body of the package.
Leadless Device. Electronic device without electrical leads
extending from the body of the package. These packages could
have solder bumps or lands located on the package.
Leakage Current. A current that flows through or across an
insulator between two electrodes.
LED. Light-Emitting Diode
Leg Angle. The angle of the vertical portion of a lead with
respect to a plane perpendicular to the plane defined by the
bottom of the component.
Leg Length. The part of the component lead between the two
bend radii. The leg length is directly related to the overall
lead form height.
Legend. Silk screened circuit designations on a printed circuit
board.
Liquidous. The temperature when a metal or alloy is completely
liquid.
Lithography, Optical. A process which passes optical radiation,
usually ultraviolet, through a phototool and projects the pattern
onto a layer of resist coating the substrate material.
Lithography, X-Ray. Similar in principle to optical lithography,
but capable of constructing much finer features due to the shorter
wavelengths involved.
Local Fiducial. Fiducial, Local
Logic Chip. A chip which does computations, makes decisions,
or makes things happen. For example, the Intel Pentium microprocessor
in a computer is a logic chip and does mathematical computations,
among other things.
Low Residue Flux. Flux, Low Residue
Low Temperature Solder. Solder, Low Temperature
lm/m2. Lumens per
square meter. A measure of light intensity.
Management Information System. Computerized network used in
effectively structuring critical information in a form usable
for identification of inefficiencies.
Manual Assembly. An electronic assembly process carried out
by an operator primarily using hand tools, including a soldering
iron.
Manufacturing Execution Systems (MES). A system that, rather
than focusing on measurements of material usage or process control,
"centers on the product itself as it moves through the plant
on the way to the customer."
Manufacturing Resource Planning (MRP). A software tool that
enables a manufacturer to plan, allocate, and track material
and financial resources for a production process.
Mask. A material applied to allow selective etching, plating,
or protection of the surface of a printed circuit board.
Material Safety Data Sheet (MSDS). A US OSHA standard format
that suppliers use to describe the hazards of the materials
they provide for use by others.
Material Requirements Planning. Manufacturing Resource Planning
Matrix Tray. Tray, Waffle
Microelectronics and Computer Technology Corp.
Multichip Module
MCM-C. Ceramic MCM
MCM-D. Deposition MCM
MCM-L. Laminated MCM
MCM-L/D, MCM-C/D. Combination MCMs
MCR. Molded Carrier Ring
MDA. Manufacturing Defects Analyzer
Mean Time Between Failures (MTBF). Average time an assembly
or machine is available to operate.
Mean Time To Repair (MTTR). Average time required to repair
the various problems of an assembly or machine.
Measling. (1) Discrete white spots below the surface of the
base material, usually caused by moisture, pressure, and/or
thermally induced stress. (2) A condition existing in the base
material in the form of discrete lighter spots of "crosses"
below the surface of the base material, which is a separation
of fibers in the glass cloth at the weave intersection.
Mechanical Adhesion. Adhesion, Mechanical
Mechanical Centering. Centering, Mechanical
MEK. Methyl Ethyl Keytone
MELF. Metal electrode leadless face is a cylindrical SMT package
form used for resistors and diodes.
Membrane Separation. A type of noncryogenic nitrogen generator.
Meniscus. The curved, upper surface of a liquid that is concave
when the containing walls are wetted by the liquid and convex
when the containing walls are not wetted by the liquid.
MES. Manufacturing Execution System
Mesh. The size of the holes on a screen used to sort powders.
Sorting sieves are dimensioned in holes per square inch.
Mesh Size. The number of openings per inch in a screen. For
example, a 325 mesh screen has 325 openings per inch.
Metal Content. The percentage weight of the solder alloy powder
in solder paste.
Metal-Core Boards. Boards built with a metallic core and an
organic or inorganic insulation on either sides of the core.
The core could be made of steel, stainless steel, aluminum,
copper, or a laminate of metals (in most cases copper Invar
copper or copper tungsten copper). The insulation of the core
is done prior to metallization.
Metering Rolls. Successive rollers used to control the fabric
to resin ratio during the impregnation of resin onto glass fabric.
Methyl Ethyl Keytone (MEK). An US EPA prohibited material
used in printed circuit board fabrication.
mg. Milligram
mg/L. Milligram/Liter
MHz. Megahertz
Microsectioning. A destructive test showing an encapsulated
cross section of a part or assembly.
Micro BGA® (µBGA®). A brand name for a fine
pitch BGA.
Micron. Micrometer. An unit of length equal to one millionth
of a meter.
Microvia. A design technique aimed at reducing substrate (product)
size. A microvia is a via less than 150um in diameter, about
a half the size of common via, and normally blind. Laser drilling
make microvias at 500X the speed of mechanical drills.
Migration. (1) Migration of adhesives from the interior to
the surface of a plastic. (2) Electrochemical Migration
Mil. One thousands of an inch.
MIS. Management Information System
Misalignment. Misregistration of the centerline of the component
lead with respect to the centerline of the pad on the substrate.
Misregistration. The lack of conformity between two or more
patterns or features.
Mixed Technology. Describes the assembly process used when
pin through hole, surface mount, and other mounting technologies
on the same printed circuit board.
MLB. Multilayer Board
Millimeter
Modification. The process revising the functional capability
or performance characteristics of a product to satisfy new acceptance
criteria. Modifications usually are required to incorporate
design changes that can be controlled by drawings, change orders,
etc.
Molded Carrier Ring (MCR). IC with a plastic molded body and
guard ring to reduce damage to leaded surface mount packages
caused by normal handling. The guard ring also acts as a common
form factor for the development of automation such as test,
burn in, and excise and form.
Mole®. A brand name for a profiler.
Molecular Weight. The sum of the atomic weight of all atoms
in a molecule.
Montreal Protocol. In 1987, twenty-four countries, including
the United States and members of the European Economic Community
signed the Montreal Protocol to control CFC and Halon compounds,
which are thought to deplete the ozone layer of the Earth.
Mounting Hole. (1) Plated-Through-Hole (PTH). (2) A hole used
in mechanically mounting a printed circuit assembly to a housing.
Mouse Bite. A method of securing a breakaway tab to the printed
circuit board.
MRP. Materials Requirements Planning
MRP II. Manufacturing Resource Planning
MSDS. Material Safety Data Sheet
MTBF. Mean Time Between Failures
MTTR. Mean Time To Repair
Multichip Module. A modular package with both active and passive
devices in one package. Versions; MCM-L, MCM-C, and MCM-D; vary
according to substrate.
Multilayer Printed Circuit Board. A laminate with more than
two layers of copper foil.
Multilayer Substrate. Usually referring to cofired multilayer
ceramic substrates.
