IPC-D-859.pdf - 第11页

card assemblies, and modules composed exclusively of dis- crete electronic parts.) Microcircuit module An assembly of microcircuits or an assembly of microcircuits and discrete parts, designed to perform one or more elec…

Film Single or multiple layers of coatings of thin or thick

material used to form various elements (resistors, capaci-

tors, inductors) or interconnections and crossovers (con-

ductors, insulators). Thick ﬁlms are deposited by screen

printing.

Film conductor A conductor formed in place on a sub-

strate by depositing a conductive material by screening,

plating, or evaporation techniques.

Film network An electrical network composed of a thin

and/or thick ﬁlm components and interconnections depos-

ited on a substrate.

Final seal The manufacturing operation that completes

the enclosure of the hybrid microcircuit so that further

internal processing cannot be performed without delidding

or disassembling the package.

Fire The term used to describe the act of heating a thick-

ﬁlm circuit so that the resistors, conductors, capacitors,

etc., will be transformed into their ﬁnal form.

Firing sensitivity Refers to the percentage change caused

in the ﬁred ﬁlm characteristics due to a change in peak ﬁr-

ing temperature. The ﬁring sensitivity is expressed in units

of %/°C.

Flip chip A leadless, monolithic structure, containing cir-

cuit 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 circuits without the need for subsequent

wire bonding.

Functional trimming Trimming a circuit element (usu-

ally resistors) on an operating circuit to set a voltage or

current on the output. (See Active trim)

Glassivation A method of semiconductor passivation by

coating the element with a pyrolytic glass deposition.

Header The base of a hybrid circuit package that holds

the leads.

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 compo-

nents.

Hybrid group (electrically and structurally similar cir-

cuits). Hybrid microcircuits which are designed to perform

the same type(s) of basic circuit function(s), for the same

supply, bias, and single voltages and for input-output com-

patibility with each other under an established set of load-

ing rules, and which are enclosed in packages of the same

construction and outline.

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 integrated circuit.

Hybrid microcircuit A microcircuit that involves an insu-

lating substrate on which are deposited networks, consist-

ing generally of conductors, resistors, and capacitors, and

to which are attached discrete semiconductor devices

and/or monolithic integrated circuits and/or passive ele-

ments to form a packaged assembly. Used interchangeably

with hybrid circuit and hybrid integrated circuit.

Integrated circuit A microcircuit (monolithic) consisting

of interconnected elements inseparably associated and

formed in place on or within a single substrate (usually

silicon) to perform an electronic circuit function.

Junction (1) in solid state materials, a region of transi-

tion between p- and n- type semiconductor material as in a

transistor or diode. (2) A contact between two dissimilar

metals or materials (e.g., in a thermocouple or rectiﬁer). (3)

A connection between two or more conductors or two or

more sections of a transmission line.

Junction temperature The temperature of the region of

transition between the p- and n-type semiconductor mate-

rial in a transistor or diode element.

Land A portion of a conductive pattern usually used for

electrical connection, component attachment, or both.

Layer One of several ﬁlms in a multiple ﬁlm structure on

a substrate.

L cut A trim notch in a ﬁlm resistor that is created by the

cut starting perpendicular to the resistor length and turning

90° to complete the trim parallel to the resistor axis thereby

creating an L-shaped cut.

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 elements to the

outside world.

Loop The curve or arc by the wire between the attach-

ment 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 dis-

tance from this line to the wire loop.

Micro-bond A bond of a small wire, such as 0.025 mm

[0.001 inch] diameter gold, to a conductor or to a chip

device.

Microcircuit A small circuit (hybrid or monolithic) hav-

ing a relatively high equivalent circuit element density,

which is considered as a single part on (hybrid) or with

(monolithic) a single substrate to perform an electronic cir-

cuit function. (This excludes printed wiring boards, circuit

IPC-D-859 December 1989

card assemblies, and modules composed exclusively of dis-

crete electronic parts.)

Microcircuit module An assembly of microcircuits or an

assembly of microcircuits and discrete parts, designed to

perform one or more electronic circuit functions, and con-

structed such that for the purposes of speciﬁcation testing,

commerce, and maintenance, it is considered indivisible.

Micro-components Small discrete components such as

chip transistors and capacitors.

Microwave integrated circuit A miniature microwave

circuit usually using hybrid circuit technology to form the

conductors and attach the chip devices.

Monolithic ceramic capacitor A term sometimes used to

indicate a multilayer ceramic capacitor.

Monolithic integrated circuit An integrated circuit con-

sisting of elements formed in place on or within a semicon-

ductor substrate with at least one of the elements formed

within the substrate.

MOS device Abbreviation for a metal oxide semiconduc-

tor device.

Multichip integrated circuit An integrated circuit whose

elements are formed on or within two or more semiconduc-

tor chips which are separately attached to a substrate or

header.

Multichip microcircuit A microcircuit consisting solely

of active dice and passive chips which are separately

attached to the major substrate and interconnected to form

the circuit.

Nailhead bond See Ball bond.

Neck break A bond breaking immediately above gold

ball of a thermo-compression bond.

Off bond Bond that has some portion of the bond area

extending off the bonding land.

Overglaze A glass coating that is over another component

or element, normally for physical or electrical protection.

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 provides

hermetic and environmental protection for, and a particular

form factor to, the assembly of electronic components.

Package cap A cuplike cover that encloses the package

in the ﬁnal sealing operation.

Package lid A ﬂat cover plate that is used to seal a pack-

age cavity.

Packaging and Interconnecting (P/I) structure The gen-

eral term for a completely processed printed board, ceramic

substrate with interconnection wiring, or other combina-

tions of substrates and interconnection wiring, used for the

purpose of mounting components.

Purple plague One of several gold-aluminum compounds

formed when bonding gold to aluminum and activated by

re- exposure to moisture and high temperature. Purple

plague is purplish and very brittle, potentially leading to

time- based failure of the bonds. Its growth is highly

enhanced by silicon to form ternary compounds.

Push-off strength The amount of force required to dis-

lodge a chip device from its mounting land by application

of the force to one side of the device, parallel to the mount-

ing surface.

Resistor paste calibration The characterizing of a resistor

paste for Ω/square value, thermal coefficient of resistance,

and other speciﬁed parameters by screening and ﬁring a

test pattern using the paste and recording the results.

Sagging or wire sag The failure of bonding wire to form

the loop deﬁned by the path of the bonding tool between

bonds.

Search height The height of the bonding tool above the

bonding area at which ﬁnal adjustments in the location of

the bonding area under the tool are made prior to lowering

the tool for bonding.

Semiconductor carrier A permanent protective structure

which provides for mounting and for electrical continuity

in application of a semiconductor chip to a major substrate.

Semiconductors Solid materials such as silicon that have

a resistivity midway between that of a conductor and a

resistor. These materials are used as substrates for semicon-

ductor devices such as transistors, diodes, and integrated

circuits.

Serpentine cut A trim cut in a ﬁlm resistor that follows a

meandering repetitive pattern to effectively increase the

resistor length and increase resistance.

Smeared bond A bond impression that has been distorted

or enlarge by excess lateral movement of the bonding tool,

or by the movement of the device-holding ﬁxture.

Squash-out The deformed area of a lead which extends

beyond the dimensions of the lead prior to bonding.

Substrate (of a microcircuit or integrated circuit) The

supporting material upon which the elements of a hybrid

microcircuit are deposited or attached or within which the

elements of an integrated circuit are fabricated.

Tail (of the bond) The free end of wire extending beyond

the bond impression of a wire bond from the heel.

Tail pull The act of removing the excess wire left when a

wedge or ultrasonic bond is made.

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.

December 1989 IPC-D-859

Thick-ﬁlm circuit A microcircuit in which passive com-

ponents 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 network A network of thick-ﬁlm resistors

and/or capacitors interconnected with thick-ﬁlm conductors

on a ceramic substrate, formed by screening and ﬁring.

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 selec-

tive pattern onto a supporting material (substrate) and fired.

Films so formed are usually 5 µm or greater in thickness.

Top hat resistors Film resistors having a projection out

one side allowing a notch to be cut into the center of the

projection to form a serpentine resistor and thereby

increase the resistivity.

Trim notch The notch made in a resistor by trimming to

obtain the design value.

Trimming Notching a resistor by abrasive or laser means

to raise the nominal resistance value.

Ultrasonic bonding A process involving the use of ultra-

sonic energy and pressure to join two materials.

Uncased device A chip device.

Via An opening in the dielectric layer through which a

conductive riser passes.

Wedge bond A bond made with a wedge tool. The term

is usually used to differentiate thermo-compression wedge

bonds from other thermo-compression bonds. (Almost all

ultrasonic bonds are wedge bonds.)

Wedge tool A bonding tool in the general form of a

wedge with or without a wire-guide hole to position the

wire under the bonding face of the tool, as opposed to a

capillary-type tool.

Wobble bond A thermo-compression, multi-contact bond

accomplished by rocking (or wobbling) a bonding tool on

the beams of a beam lead device.

3.2 Design Features The design features of the thick

ﬁlm multilayer hybrid circuits shall be in accordance with

this standard. Quality conformance test circuitry should be

included on each panel and shall be in accordance with

Section 6. Test circuitry shall be not more than 10 mm

[0.400 inch] and shall be not less than 5 mm [0.200 inch]

from the edge of the hybrid circuit, and shall reﬂect the

design of the circuit and all the manufacturing processes.

Quality conformance test circuitry shall also be included on

the master pattern, master drawing and artwork in accor-

dance with Section 6.

3.3 Documentation Package The designer shall estab-

lish the documentation package necessary to deﬁne, pro-

duce, and test a hybrid microcircuit which is adequate for

the customer’s end-use requirements. This section will

describe a typical documentation package that includes the

details required by the various disciplines involved with the

manufacturing processes.

3.3.1 Master Drawing Package The master drawing

package is composed of the various individual drawings, or

combinations necessary to speciﬁcally deﬁne the physical,

electrical, and environmental criteria applicable to the

hybrid microcircuit.

Master drawings shall be prepared in accordance with IPC-

D-325. Dimensioning and tolerancing practices used in

master drawings shall be in accordance with IPC-D-300.

3.3.1.1 Schematic The schematic is a diagram of a

functional electronic circuit consisting of symbols of all

active and passive elements and their interconnections that

form the circuit. The schematic should include the follow-

ing information:

1. Power supply voltages

2. Input signal requirements

3. Pin-out numbers and functions

4. Test points

5. Active and passive circuit element reference identiﬁca-

tion, part number, value, and tolerance.

3.3.1.2 Assembly Drawing The Assembly Drawing

shows package outlines with the components mounted in

their proper locations and denotes interconnection instruc-

tions. This drawing should contain:

1. Package outlines

2. List of material

3. Special handling (electrostatic discharge [ESD] cau-

tion, fragility, assembly environments, coatings, tailor-

ing, radiation- hardening, etc.)

4. Marking requirements (traceability, federal code, part

number, etc.)

5. Applicable procedures (Assembly Test Plan (ATP),

visual characteristics, customer speciﬁcations, etc.)

6. Component locations and provisions for use of alter-

nate components

7. Burn-in circuit and other conditions that may be a part

of other documentation, such as an ATP.

8. As-required material (e.g., wire, epoxy, etc.)

3.3.1.3 Artwork Artwork is required to produce:

1. Dielectric screens

2. Via screens

IPC-D-859 December 1989