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ADHESION
The property of one material to remain attached to another; a measure of the bonding strength of the interface between film deposit and the surface which receives the deposit; the surface receiving the deposit may be another film or substrate.

ALUMINA
Aluminium oxide (Al tex2html_wrap_inline1418 O tex2html_wrap_inline1420 ), a ceramic material often used for substrates, or in ceramic bottom construction packages. Most alumina substrates contain 90-99% aluminium oxide.

ASSEMBLY
A film circuit to which discrete components have been attached. It might also shown the assembly of one or more film circuits which may include several discrete components.

BACK BONDING
Bonding active chips to the substrate using the back of the chip, leaving the face, with its circuitry face up. The opposite of back bonding is face-down bonding.

BALL BOND
A bond formed when a ball shaped end interconnecting wire is deformed by thermocompression against a metallised pad. The bond is also designated a nail head bond from the appearance of a flattened ball.

BOND
An interconnection which performs a permanent electrical and/or mechanical function.

BOND PAD
See bonding area.

BOND SEPARATION
The distance between the attachment points of the first and second bonds of a wire bond.

BONDING AREA
The area, defined by the extent of a metallisation land or the top surface of the terminal, to which a lead is or is to be bonded.

BONDING PAD
A metallised area at the end of a thin metallic strip to which a connection is to be made.

BONDING WIRE
Fine gold or aluminium wire for making electrical interconnection in hybrid circuits between various bonding pads on the semiconductor device substrate and device terminals or substrate land.

BONDING, DIE
Attaching the semiconductor chip to the substrate, either with an epoxy, eutectic or solder alloy.

BURIED VIA
An interstitial via connecting inner conductive layers of a printed board but not extending to either surface.

CERAMIC
Inorganic nonmetallic material such as alumina, beryllia, or fosterite, whose final characteristics are produced by treatment at high temperatures (and sometimes also under applied pressure), often used in microelectronics as parts of components, substrate, or package.

CHIP
The uncased and normally leadless form of an electronic component part, either passive or active, discrete or integrated.

CHIP CARRIER
A special type of enclosure or package to house a semiconductor device or a hybrid microcircuit and which has metallised castellations as usually electrical terminations around its perimeter, as well as solder pads on its underside, rather than an extended lead frame or plug-in pins.

CIRCUIT
The interconnection of a number of electrical elements and/or devices, performing a desired electrical functions. A circuit must contain one or more active elements (devices) in order to distinguish it from a network.

COFIRING
Processing thick-film conductors and resistors through the firing cycle at the same time.

COMPONENT
A diversely used term, which, dependent on context, may mean active or passive element, device, integrated or functional circuit, functional unit , or part of an operating system.

COMPONENT DENSITY
The number of components per unit area.

CONDUCTIVE ADHESIVE
An adhesive material that has metal powder added to increase electrical conductivity.

CONDUCTIVE FOIL
The conductive material covering one or both sides of the base material used to form the conductive pattern.

CONDUCTOR
A single conductive path formed in the conductive foil.

CONDUCTORS
A class of materials that conduct electricity easily, i.e., have low resistivity ( tex2html_wrap_inline1422 ).

CONTACT ANGLE
The angle made between the bonding material and the bonding pad.

CONTACT AREA
The common area between two mating conductors permitting the flow of electricity.

CONTACT SPACING
The centreline-to-centreline spacing of adjacent contact areas.

DENSITY
Weight per unit volume of a substance.

DEVICE
A single discrete electronic element such as a transistor or resistor, or a number of elements integrated within on die, which cannot be further reduced or divided without eliminating its stated function. Preferred usage is die or dice, bare or prepackaged.

DICE
the plural of die.

DIE
An uncased discrete or integrated device obtained from a semiconductor wafer (see Chip).

DIE ATTACH
The technique of mounting chips to a substrate. Methods include AuSi eutectic bonding, various solders, and conductive (and nonconductive) epoxies.

DIFFUSION
The phenomenon of movement of matter at the atomic level from regions of high concentration to regions of low concentration. A thermal process by which minute amounts of impurities are deliberately impregnated and distributed into semiconductor material.

DOPING
The addition of an ionic impurity to a semiconductor to alter its conductivity in desired well-defined area and to specified depth.

DUAL IN-LINE PACKAGE (DIP)
A package having two rows of leads extending at right angles from the base and having standard spacing between leads and between rows of leads.

ELECTRICAL PROPERTIES
The properties of a device or material that effect its conductivity or resistivity to the flow of an electric current.

ELECTRONIC PACKAGING
The technical discipline of designing a protective enclosure for an electronic circuit so that it will both survive and perform under a plurality of environmental conditions.

ELEMENT
A constituent unit which contributes to the operation of a hybrid microcircuit. Integral elements include deposited or screened passive circuit elements , metallisation paths, and deposited or formed insulation. Discrete elements include wires or ribbon.

ENCAPSULATE
Sealing up or covering an element or circuit for mechanical and environmental protection.

ENCAPSULATION
The process of completely enclosing an article in an envelope of dielectric material.

ETCHING
The chemical, or chaemcal and electrolytic, removal of selected conductive material to form a conductive pattern.

EXTERNAL LEADS
Electronic package conductors for input and output signals, power, and ground. Leads can be either flat ribbons or round wires.

FACE BONDING
The opposite of back bonding. A face bonded semiconductor chip is one that has its circuitry side facing the substrate. Flip-chip and beam lead bonding are the two common face bonding methods.

FAILURE
In ability of a product to meet its performance specifications.

FILM
Single or multiple layers or coatings of thin or thick material used to form various elements (resistors, capacitors, inductors) or interconnections and crossovers (conductors, insulators). Thin films are deposited by vacuum evaporation or sputtering and/or plating. Thick films are deposited by screen printing.

FILM CONDUCTOR
A conductor formed in situ on a substrate by depositing a conductive by screening, plating, or evaporation techniques.

FLAT PACK
An integrated circuit package having its leads extended from the sides and parallel to the base.

FLIP-CHIP
A leadless monolithic structure, containing circuit elements, which is designed to electrically and mechanically interconnect to the hybrid circuit by means of an appropriate number of bumps located on its face which are covered with a conductive bonding agent.

FLIP-CHIP MOUNTING
A method of mounting flip chips on thick- or thin film circuit without the need for subsequent wire bonding.

HERMETIC
A description of packages that provide an absolute seal against the infusion of water to prevent degradation of the electrical components within the package. The test for Hermeticity is to observe lead rates when placed in a vacuum.

HERMETICITY
The ability of a package to prevent exchange of its internal gas with the external atmosphere. The figure of merit is the gaseous leak rate of the package measured in Pa-m tex2html_wrap_inline1314 -sec tex2html_wrap_inline1426 .

HYBRID CIRCUIT
A microcircuit consisting of elements which are a combination of the film circuit type and the semiconductor circuit type, or a combination of one or both of these types and may include discrete add-on components.

HYBRID INTEGRATED CIRCUIT
A microcircuit including thick film or thin film paths and circuit elements on a supporting substrate, to which active and passive micro-devices are attached, either prepackaged or in uncased form as chips, usually all enclosed in a suitable package (hermetic or epoxy type). Used interchangeably with hybrid circuit and hybrid microcircuit.

HYBRID MICROCIRCUIT
A microcircuit that involves an insulating substrate on which are deposited networks, consisting generally of conductors, resistors, and capacitors, and to which are attached discrete semiconductor devices and/or monolithic integrated circuits and/or passive elements to form a packaged assembly. Used interchangeably with hybrid circuit and hybrid integrated circuit.

HYBRID MICROELECTRONICS
The entire body of electronic art which is connected with or applied to the realisation of electronic systems using hybrid circuit technology.

INFERRED
The band of electromagnetic wavelengths lying between the extreme of the visible (= 0.75 ) and the shortest microwaves (= 1000 ). Warm bodies emit the radiation and bodies which absorb the radiation are warmed.

INTEGRATED CIRCUIT (IC)
A microcircuit (monolithic) consisting of interconnected elements inseparably associated and formed in situ on or within a single substrate (usually silicon) to perform an electronic circuit function.

INTERCONNECTION
The conductive path required to achieve connection from a circuit element to the rest of the circuit.

INTERCONNECTIONS
Connections of conductors make within a circuit on the same substrate.

LAMINATE
A layer sandwich of sheets of substances bonded together under heat and pressure to form a single structure.

LASER BONDING
Effecting a metal-to-metal bond of two conductors by welding the two materials together using a laser beam for a heat source.

LAYER
One of several films in a multiple film structure on a substrate.

LAYOUT
The positioning of the conductors and/or resistors on artwork prior to photoresuction of the layout to obtain a working negative or positive used in screen preparation.

LEAD
A conductive path which is usually self-supporting.

LEAD FRAMES
The metallic portion of the device package that completes the electrical connection path from the die or dice and from ancillary hybrid circuit element to the outside world.

LEAD WIRES
Wire conductors used for interconnections using fine wires (Au or Al), or interconnections that include input/output leads.

LOOP
The curve or arc by the wire between the attachment points at each end of a wire bond.

LOOP HEIGHT
A measure of the deviation of the wire loop from the straight line between the attachment points of a wire bond. Usually, it is the maximum perpendicular distance from this line to the wire loop.

MICRON
An obsolete unit of length equal to a micrometer (mm).

MODULE
A generic term referring to separable units in electronic packaging.

MONOLITHIC INTEGRATED CIRCUIT
An integrated circuit consisting of elements formed in situ on or within a semiconductor substrate with at least one of the elements formed within the substrate.

MOS DEVICE
Abbreviation for a metal oxide semiconductor device.

MULTICHIP (MICROCIRCUIT) MODULE
A microcircuit consisting solely of active dice and passive chips which are separately attached to the major substrate and interconnected to form the circuit.

MULTICHIP INTEGRATED CIRCUIT
An integrated circuit whose elements are formed on or within two or more semiconductor chips which are separately attached to a substrate header.

MULTILAYER CIRCUITS
A composite circuit consisting of alternate layers of conductive circuitry and insulating materials (ceramic of dielectric compositions) bonded together with the conductive layers interconnected as required.

MULTILAYER PRINTED BOARD
Printed circuit or printed wiring configuration that consists of more than two conductive layers bonded together to form a multiple conductive layer assembly. The term applies to both rigid and flexible multilayer boards.

MULTILAYER PRINTED WIRING BOARD
A multilayer printed board assembly manufactured from completely processed printed wiring that is used only to interconnect between components and provide I/O.

NOISE
Random small variations in voltage or current in a circuit due to the quantum nature of electronic current flow, thermal considerations, etc.

OVERLAP
The contact area between dissimilar (film) materials, e.g., between a film resistor and its termination(s).

OVERLAY
One material applied over another material.

PACKAGE
The container for an electronic component(s) with terminals to provide electrical access to the inside of the container. In addition, the container usually provide hermetic and environmental protection for, and a particular form factor to, the assembly of electronic components.

PACKAGE LID
A flat cover plate that is used to seal a package cavity.

PACKAGING DENSITY
The amount of function per unit volume, often defined qualitatively as high, medium, or low.

PAD
A metallised area on the surface of an active substrate as an integral portion of the conductive interconnection pattern to which bonds or test probes may be applied.

PAD GRID ARRAY
A package that is an SMT derivative of PGA; substituting soldering pads on the underside for the customary pins.

PASTE
Synonymous with composition and ink when relating to screenable thick-film materials.

PATTERN
The outline of a collection of circuit conductors and resistors that defines the area to be covered by the material on a film circuit substrate.

PERMEABILITY
(1) The passage by diffusion (or rate of passage) of a gas, vapour, liquid, or solid through a barrier without physically or chemically affecting it. (2) The ability of a material to carry magnetism, compared to air, which has a permeability of 1.

PHASE
(As a glassy phase or metal phase). Refers to the part or portion of materials system that is metallic or glassy in nature. A phase is a structurally homogeneous physically distinct portion of a substance or a group of substances which are in equilibrium with each other.

PIN DENSITY
The number of pins per unit area on a printed board.

PITCH
The nominal centreline-to-centreline dimension between adjacent conductors.

PLASTIC
A polymeric material, either organic (e.g. epoxy) or silicone used for conformal coating, encapsulation, or over-coating.

PLASTIC DEVICE
A device wherein the package, or the encapsulant material for semiconductor die, is plastic. Such materials as epoxies, phenolic, silicon, etc. are included.

PLASTIC ENCAPSULATION
Environmental protection of a completed circuit by embedding it in a plastic such as epoxy or silicone.

PLASTIC SHELL
A thin plastic cup or box used to enclose an electronic circuit for environmental protection or used as a means to confine the plastic encapsulant used to embed the circuit.

PLATED THROUGH HOLE
A hole with a plated wall used for electrical interconnection between internal and/or external conductive layers.

POINT-TO-POINT WIRING
An interconnecting technique wherein the connections between components are made by wires routed between connecting points.

POWER DENSITY
The amount of power dissipated from a film resistor through the substrate measured in W-cm-2.
PRINTED BOARD
The generic term for processed printed circuit and printed wiring boards, either single or double and multilayer boards.

PRINTED CIRCUIT ASSEMBLY
One or more populated printed circuit boards that perform a specific function in a system.

PRINTED CIRCUIT BOARD
A printed board that consists of conductive pattern which includes printed components and/or printed wiring.

PRINTED CONTACT
A contact area that is formed in the conductive pattern.

PRINTED WIRING ASSEMBLY
One or more populated printed wiring boards that perform a specific function in a system.

PRINTED WIRING BOARD
A printed board containing a conductive pattern which consists only of printed wiring.

PRINTED WIRING LAYOUT
A design document that depicts the printed wiring, electrical, and mechanical component sizes and locations with sufficient detail that documentation and artwork may be generated from the document.

PRODUCT
An item component, device, group of devices, or system.

QUALITY CONFORMANCE TEST CIRCUITRY
A section of a printed board containing test coupons used to determine the boards acceptability.

RC NETWORK
A network composed only of resistors and capacitors

REDUNDANCY
The existence of more than one means of accomplishing a given task, where all means must fail before there is an overall failure of the system. Parallel redundancy applies to systems in which both means are working at the same time to accomplish the task and either of the systems is capable of handling the job itself in case of failure of the other system. Standby redundancy applies to a system in which there is an alternative means of accomplishing the task that is switched in by malfunction-sensing device when the primary system fails.

REFLOW SOLDERING
A method of soldering involving application of solder prior to the actual joining. To solder, the parts are joined and heated, causing the solder to remelt, or reflow.

RELIABILITY
The probability that a product will perform a stated function satisfactorily at a desired confidence level for a set period of time under a specified environment.

REPAIR
An operation performed on a non-conforming part or assembly to make it functionally suable but which does not completely eliminate the nonconformance.

RESIN RECESSION
Void between the barrel of a plated through hole and the wall of the hole which is usually due to board exposure to high temperatures. These are usually detected by microsectioning the printed board.

RESIST
A protective coating that will keep another material from attaching or coating something, as in solder resist, plating resist, or photoresist.

RESISTIVITY
A proportionality factor characteristic of different substances equal to the resistance that a centimetre cube of the substance offers to the passage of electricity, the current being R = rL/A, where R is the resistance of a uniform conductor, L its length, A it cross-sectional area, and r its resistivity. Resistivity is usually expressed in ohm-centimetres. The ability of a material to resist passage of electrical current either through its bulk or on a surface.

REWORK
An operation performed on a non-conforming part or assembly that restores all nonconforming characteristics to the requirements in the contract, specification, drawing, or other approved product description.

RIBBON INTERCONNECT
A flat narrow ribbon of metal such as nickel, aluminium, or gold used to interconnect circuit elements or to connect the element to the output pins.

RIBBON WIRE
Metal in the form of a very flexible flat thread or slender rod or bar tending to have a rectangular cross section as opposed to a round cross section.

SAMPLE
A random selection of units from a lot for the purpose of evaluating the characteristics or acceptability of the lot. The sample may be either in terms of units or in terms of time.

SAPPHIRE
A single-crystal A12O3 substrate material used in integrated circuits.

SCHEMATIC
Diagram of a functional electronic circuit composed of symbols of all active and passive elements and their interconnecting matrix that forms the circuit.

SCRATCH
In optical observations, a surface mark with a large length-to-width ratio.

SCREEN
A network of metal or fabric strands, mounted snugly on a frame, and upon which the film circuit patterns and configurations are superimposed by photographic means.

SCREENING
The process whereby the desired film circuit patterns and configurations are transferred to the surface of the substrate during manufacture, by forcing a material through the open areas of the screen using the wiping action of a soft squeegee

SEMICONDUCTORS
Solid materials such as silicon that have a resistivity midway between those of a conductor and a resistor. These materials are used as substrates for semiconductor devices such as transistors, diodes, and integrated circuits.

SHEAR STRENGTH
The limiting stress of a material determined by measuring a strain resulting from applied forces that cause or tend to cause bonded contiguous parts of a body to slide relative to each other in a direction parallel to their plane of contact; the value of the force achieved when shearing stress is applied to the bond (normally parallel to the substrate) to determine the breaking load. Strength to withstand shearing of a material.

SIGNAL
An electrical impulse of specified voltage, current, polarity, and pulse width.

SILICON MONOXIDE
A passivating or insulating material that is vapour deposited on selected areas of a thin-film circuit.

SLICE
A thin cross section of a crystal such as silicon that is used for semiconductor substrates.

SOLDER BALLS
Small solder spheres that adhere to the surface of the printed board after reflow or wave soldering. The solder balls are more predominant with an uncontrolled soldering process using solder paste.

SOLDER BUMPS
The round solder balls bonded to a transistor contact area and used to make connection to a conductor by face-down bonding techniques.

SOLID STATE
Pertaining to circuits and components using semiconductors as substrates.

SPACING
The distance between adjacent conductor edges.

SUBSYSTEM
A smaller part of an electronic system which performs a part of the system function but can be removed intact and tested separately.

SYSTEM
A product which for most considerations is repairable. Examples include computers, radars, and power supplies.

TAPE AUTOMATED BONDING(TAB)
The utilisation of a metal or plastic tape material as a support and carrier of a microelectronic component in a gang bonding process.

THICK FILM
A film deposited by screen printing processes and fired at high temperature to fuse into its final form. The basic processes of thick-film technology are screen printing and firing.

THICK-FILM CIRCUIT
A microcircuit in which passive components of a ceramic-metal composition are formed on a suitable substrate by screening and firing.

THICK-FILM HYBRID CIRCUIT
A hybrid microcircuit that has add-on components, usually chip devices added to a thick-film network to perform an electronic function.

THICK-FILM TECHNOLOGY
The technology whereby electrical networks or elements are formed by applying a liquid, solid or paste coating through a screen or mask in a selective pattern onto a supporting material (substrate) and fired. Films so formed are usually 5 mm or greater in thickness.

THIN FILM
A thin film (usually less than 5 mm thickness) is one that is deposited onto a substrate by an accretion process such as vacuum evaporation, sputtering, chemical vapour deposition, or pyrolytic decomposition.

THIN-FILM HYBRID CIRCUIT
A hybrid microcircuit that has add-on components, usually chip devices added to a thin-film network to perform an electronic function.

THIN-FILM INTEGRATED CIRCUIT
A functioning circuit made entirely of thin-film components. Also used to mean thin-film hybrid circuit.

THIN-FILM TECHNOLOGY
The technology whereby electronic networks or elements are formed by vacuum evaporation or sputtering films onto a supporting material (substrate). Films so formed are less than 5 and usually of the order 0.3 to 1.0 mm in thickness.

THROUGH CONNECTION
An electrical connection between different conductive layers.

THROUGH HOLE MOUNTING
The electrical interconnection of components with leads that insert through the holes of a printed board.

TIP
That portion of the bonding tool which deforms the wire to cause the bond impression.

TOPOLOGY
The surface layout design study and characterisation of a microcircuit. It has application chiefly in the preparation of the artwork for the layout masks used in fabrication.

VEHICLE
A thick-film term that refers to the organic system in the paste.

VIA
An opening in the dielectric layer(s) through which a riser passes, or else whose walls are made conductive.

VIA HOLE
A plated through hole providing electrical interconnection for two or more conductive layers but not intended to have a component lead inserted through it.

VISCOSITY
A term used to describe the fluidity of material, or the rate of flow versus pressure. The unit of viscosity measurement is poise, more commonly centipoise. Viscosity varies inversely with temperature.

VISCOSITY COEFFICIENT
The coefficient of viscosity is the value of the tangential force per unit area which is necessary to maintain unit relative velocity between two parallel planes a unit distance apart.

VOID
In visual inspection of solid materials, a space not filled with the specific solid material, such as a gap or opening which is an unintentional defect in the material.

WAFER
A slice of semiconductor crystal ingot used as a substrate for transistors, diodes, and monolithic integrated circuits.

WIRE BOND
A completed wire connection which includes all its constituents providing electrical continuity between the semiconductor die (pad) and a terminal. These constituents are the fine wire; metal bonding surfaces like die pad and package land; metallurgical interfaces underneath the bonded-wire deformation; underlying insulating layer (if present); and substrate.

WIRE BONDING
The method used to attach very fine wire to semiconductor components to interconnect these components with each other or with package leads.

YIELD
The ratio of useable components at the end of a manufacturing process to the number of components initially submitted for processing. Can be applied to any input-output stage in processing, and so must be carefully defined and understood.

YIELD STRENGTH
Strength at a point at which the strain begins to increase very rapidly without a corresponding increase in stress.


next up previous contents
Next: References Up: 3D VLSI Packaging Technology Previous: Conclusion

Said F. Al-Sarawi,
Centre for High Performance Integrated Technologies and Systems (CHIPTEC),
Adelaide, SA 5005,
March 1997