Printed board design, manufacture and assembly - Terms and definitions

This International Standard defines the terminology used in the field of printed circuit boards and printed circuit board assembly products.

Konstruktion, Herstellung und Bestückung von Leiterplatten - Begriffe und Definitionen

Conception, fabrication et assemblage des cartes imprimées - Termes et définitions

Načrtovanje, izdelava in sestavljanje tiskanih plošč – Izrazi in definicije (IEC 60194:2006)

General Information

Status
Published
Publication Date
30-Nov-2006
Current Stage
6060 - National Implementation/Publication (Adopted Project)
Start Date
01-Dec-2006
Due Date
01-Dec-2006
Completion Date
01-Dec-2006

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EUROPEAN STANDARD EN 60194 NORME EUROPÉENNE
EUROPÄISCHE NORM July 2006
CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2006 CENELEC -
All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 60194:2006 E
ICS 31.180; 31.190
English version
Printed board design, manufacture and assembly -
Terms and definitions (IEC 60194:2006)
Conception, fabrication et
assemblage des cartes imprimées -
Termes et définitions (CEI 60194:2006)
Konstruktion, Herstellung und
Bestückung von Leiterplatten -
Begriffe und Definitionen (IEC 60194:2006)
This European Standard was approved by CENELEC on 2006-06-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration.
Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CENELEC member.
This European Standard exists in English only. A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom.



EN 60194:2006
- 2 -
Foreword The text of the International Standard IEC 60194:2006, prepared by IEC TC 91, Electronics assembly technology, was submitted to the Unique Acceptance Procedure and was approved by CENELEC as EN 60194 on 2006-06-01 without any modification. This European Standard should be used in conjunction with IEC 60050-541 which provides for basic technical terms for board assembly technology not included in this standard. The following dates were fixed: – latest date by which the EN has to be implemented
at national level by publication of an identical
national standard or by endorsement
(dop)
2007-06-01 – latest date by which the national standards conflicting
with the EN have to be withdrawn
(dow)
2009-06-01 Annex ZA has been added by CENELEC. __________ Endorsement notice The text of the International Standard IEC 60194:2006 was approved by CENELEC as a European Standard without any modification. __________



- 3 - EN 60194:2006
Annex ZA
(normative)
Normative references to international publications with their corresponding European publications
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
NOTE
When an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies.
Publication Year Title EN/HD Year
IEC 60050-541 -1) International electrotechnical vocabulary - Chapter 541: Printed circuits - -
1) Undated reference.







INTERNATIONAL STANDARD IEC60194 Fifth edition2006-02 Printed board design, manufacture
and assembly – Terms and definitions
 IEC 2006

Copyright - all rights reserved No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Electrotechnical Commission,
3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, SwitzerlandTelephone: +41 22 919 02 11 Telefax: +41 22 919 03 00 E-mail: inmail@iec.ch
Web: www.iec.ch XE For price, see current cataloguePRICE CODE
Commission Electrotechnique InternationaleInternational Electrotechnical Commission



– 2 – 60194  IEC:2006(E)
INTERNATIONAL ELECTROTECHNICAL COMMISSION ___________
PRINTED BOARD DESIGN, MANUFACTURE AND ASSEMBLY – TERMS AND DEFINITIONS
FOREWORD 1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising all national electrotechnical committees (IEC National Committees). The object of IEC is to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with an IEC Publication. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable for the correct application of this publication. 9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International Standard IEC 60194 has been prepared by IEC technical committee 91: Electronics assembly technology.
This fifth edition cancels and replaces the fourth edition (1999) and constitutes a technical revision. The major change with regard to the previous edition concerns the addition of some four hundred new terms necessary to industry, added as a result of considerable development in
assembly technology in recent years.
The text of this standard is based on the following documents: FDIS Report on voting 91/566/FDIS 91/578/RVD
Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2. IEC 60194 should be read in conjunction with IEC 60050(541) which provides for basic technical terms for board assembly technology not included in this standard.



60194  IEC:2006(E) – 3 –
The committee has decided that the contents of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to the specific publication. At this date, the publication will be
• reconfirmed, • withdrawn, • replaced by a revised edition, or • amended. A bilingual version of this standard may be issued at a later date.



– 4 – 60194  IEC:2006(E)
PRINTED BOARD DESIGN, MANUFACTURE AND ASSEMBLY – TERMS AND DEFINITIONS
1 Scope This International Standard defines the terminology used in the field of printed circuit boards and printed circuit board assembly products. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60050(541), International Electrotechnical Vocabulary (IEV) – Chapter 541: Printed circuits
3 General The terms have been classified according to the decimal classification code (DCC) and this DCC number appears to the right of the defined term. The DCC numbering is explained fully in Annex A. In order to avoid two ID numbers, the usual practice of numbering every paragraph (every term and definition) in front of the paragraph has not been followed in this standard. The official IEC number is the number which follows the DCC and the period (21.xxxx). Annex B provides a list of acronyms listed numerically according to the DCC number.



60194  IEC:2006(E) – 5 –
4 Terms and definitions
Abrasion Resistance 54.1821 The ability of a material to withstand surface wear.
Abrasive Trimming
54.1318 Adjusting the value of a film component by notching it with a finely- adjusted stream of an abrasive material against the resistor surface.
Absorption Coefficients
40.1727 The degree to which various materials absorb heat or radiant energy when compared to each other.
Absorptivity, Infra-red 40.0087 The ratio (or percentage) of the amount of energy absorbed by a substrate as compared with the total amount of incident energy.
Accelerated Aging
93.0001 A test in which the parameters such as voltage and temperature are increased above normal operating values to obtain observable or measurable deterioration in a relatively short period of time.
Accelerated Life Test 93.0119 See “Accelerated Aging”.
Accelerated Test 93.0216 A test to check the life expectancy of an electronic component or electronic assembly in a short period of time by applying physically severe condition(s) to the unit under test.
Accelerator
53.0002 See “Catalyst”.
Acceleration Factor (AF)
93.0260 The ratio of stress in reliability testing to the normal operating condition.
Acceptance Quality Level (AQL)
90.0003 The maximum number of defectives likely to exist within a population (lot) that can be considered to be contractually tolerable; normally associated with statistically derived sampling plans.
Acceptance Tests
92.0004 Those tests deemed necessary to determine the acceptability of a product and as agreed to by both purchaser and vendor.
Acceptance Inspection (Criteria) 92.0288 An inspection that determines conformance of a product to design specifications as the basis for acceptance.
Access Hole
60.1319 A series of holes in successive layers of a multilayer board, each set having their centres on the same axis. These holes provide access to the surface of the land on one of the layers of the board. (See Figure A.1.)
Figure A.1 – Access hole
Access Protocol
21.0005
An agreed principle for establishing how nodes in a network communicate electronically.
Accordion Contact 36.0006
A type of connector contact that consists of a flat spring formed into a "Z" shape in order to permit high deflection without overstress.
Accuracy
90.0007 The deviation of the measured or observed value from the true value.
Acid Flux
46.0009 A solution of an acid and an inorganic, organic, or water soluble organic flux. (See also “Inorganic Flux,” “Organic Flux,” and “Water Soluble Organic Flux”.)
Acid Number
54.0010 The amount of potassium hydroxide in milligrams that is required to neutralize one gram of an acid medium.



– 6 – 60194  IEC:2006(E)
Acid Value
54.1217 See “Acid Number”
Acid-Core Solder
46.0008 Wire solder with a self-contained acid flux.
Actinic Radiation
52.0011 Light energy that reacts with a photosensitive material in order to produce an image.
Active Desiccant
30.0397 Desiccant that is either fresh (new) or has been baked according to the manufacturer’s recommendations to renew desiccant to original specifications.
Activated Rosin Flux
46.0012 A mixture of rosin and small amounts of organic-halide or organic-acid activators. (See also “Synthetic Activated Flux”.)
Activating
53.0013 A treatment that renders nonconductive material receptive to electroless deposition.
Activating Layer
53.0014 A layer of material that renders a nonconductive material receptive to electroless deposition.
Activator
46.0015 A substance that improves the ability of a flux to remove surface oxides from the surfaces being joined.
Active Device
30.0016
An electronic component whose basic character changes while operating on an applied signal. (This includes diodes, transistors, thyristors, and integrated circuits that are used for the rectification, amplification, switching, etc., of analog or digital circuits in either monolithic or hybrid form.)
Active Metal
36.0017 A metal that has a very high electromotive force.
Active Trimming
54.1321 Adjusting the value of a film circuit element in order to obtain a specified functional output from the circuit while it is electrically activated.
Actual Size
90.0018 The measured size.
Additive Process
53.1322 A Process for obtaining conductive patterns by the selective deposition of conductive material on clad or unclad base material. (See also “Semi-Additive Process” and “Fully-Additive Process”.)
Add-On Component
30.0019 Discrete or integrated packaged or chip components that are attached to a film circuit in order to complete the circuit's function.
Adhesion
(Pressure Sensitive Tape) 46.2038 The bond produced by contact between pressure-sensitive adhesive and a surface.
Adhesive
46.1728 A substance such as glue or cement used to fasten objects together. In surface mounting, an epoxy adhesive is used to adhere SMDs to the substrate.
Adhesion Failure
96.0020 The rupture of an adhesive bond such that the separation appears to be at the adhesive-adherent interface.
Adhesion Layer
74.0021 The metal layer that adheres a barrier metal to a metal land on the surface of an integrated circuit.
Adhesion Promotion
53.0022 The chemical process of preparing a surface to enhance its ability to be bonded to another surface or to accept an over-plate.
Adhesive Coated Substrate 41.0438 A base material upon which an adhesive coating is applied, for the purpose of retaining the conductive material (either additively applied or attached as foil for subtractive processing), that becomes part of a metal-clad dielectric.
Adhesive-Coated Catalyzed Laminate 41.1320 A base material with a thin polymer coating, that contains a plating catalyst, that is subsequently treated in order to obtain a microporous surface.



60194  IEC:2006(E) – 7 –
Adhesive-Coated Uncatalyzed
Laminate
41.1323
A base material with a thin polymer coating, that does not contain a plating catalyst, that is subsequently treated in order to obtain a microporous surface.
Adhesive Transfer
(Pressure Sensitive Tape) 75.0558 The transfer of adhesive from its normal position on the pressure sensitive tape to the surface to which the tape was attached, either during unwind or removal.
Adsorbed Contaminant
96.0023
A contaminant attracted to the surface of a material that is held captive in the form of a gas, vapour or condensate.
Advanced Statistical Method
91.0024
A statistical process analysis and control technique that is more- sophisticated and less widely-applicable than basic statistical methods.
Aging
90.0025 The change of a property, e.g. solderability, with time. (See also “Accelerated Aging”.)
Air Contamination
14.0026 See “Air Pollution”
Air Pollution
14.0027 Contamination of the atmosphere with substances that are toxic or otherwise harmful.
Algorithm
11.0849 A set of procedures for the solution of a problem in a series of steps.
Alignment Mark
22.0030
A stylized pattern that is selectively positioned on a substrate material to assist in alignment. (See Figure A.2).
Figure A.2 – Alignment mark
Aliphatic Solvents
76.0031 "Straight chain" solvents, derived from petroleum, of low solvent power.
Alkaline Cleaner
76.0032 A material blended from alkali hydroxides and alkaline salts.
All Metal Package 33.0579 A hybrid circuit package made solely of metal, without glass or ceramic.
Allowable Temperature 75.0609 The temperature range that an electronic circuit or component can perform its intended functions.
Alloy, Tin Bismuth (Sn-Bi) 45.1947 An alloy that is used as a lead free solder and consisting of tin and bismuth as the main constituents. Sn-Bi58 has a low melting point of 138 °C, but is not widely used because of its brittle properties.
Alloy, Tin Copper (Sn-Cu) 45.1948 An alloy that is used as a lead free solder consisting of tin and copper considered to be applicable for wave or reflow soldering.
Alloy, Tin Silver (Sn-Ag) 45.1949 An alloy that is used as a lead free solder and consisting of tin and silver as the main constituents used as a high temperature solder.
Alloy, Tin Silver Bismuth
(Sn-Ag-Bi) 45.1950 An alloy that is used as a lead free solder and consisting of tin, silver and bismuth as the main constituents. The Bi in Sn-Ag-Bi alloy reduces the melting temperature. The higher the Bi content is, higher the mechanical strength, but with poorer elongation capability. There is a limit to Bi content.
Alloy, Tin Silver Copper
(Sn-Ag-Cu) 45.1951 An alloy that is used as a lead free solder consisting of tin, silver and copper as the main constituents.
Alloy, Tin Zinc (Sn-Zn) 45.1952 An alloy that is used as a lead free solder and consisting of tin and zinc as the main constituents. Zn09 alloy has the melting point of 199 °C, closest to the melting point of Sn-Pb alloy among lead free solders, which allows soldering work at present soldering temperatures, but tends to form a



– 8 – 60194  IEC:2006(E)
stable oxide film, causing difficulty in securing a good solder wetting. Alpha Error
91.0033 The size of a Type I error or the probability of rejecting a hypothesis that is true.
Alphanumerical
25.1729 Pertaining to data that contain the letters of an alphabet, the decimal digits, and may contain control characters, special characters and the space character.
Alpha Particle 35.0612 A He4 nucleus generated from a nuclear decay that is capable of generating hole-electron pairs in microelectronic devices and switching cells causing soft errors in some devices.
Alternating Current (ac)
21.1793 A current that varies with time, commonly applied to a power source that switches polarity many times per second, in the shape of a sinusoidal, square, or triangular wave.
Alternative Hypothesis
93.1324 The supposition that a significant difference exists between the desired results of two comparable populations. (See also “Null Hypothesis” and “Statistical Hypothesis”.)
Alumina Substrate
43.1730 Aluminum oxide used as a ceramic substrate material.
Ambient
29.0034 The surrounding environment coming into contact with the system or component in question.
Amorphous Polymer
40.0035 A polymer with a random and unstructured molecular configuration.
Amplitude, Voltage
21.0036
The magnitude of a voltage as measured with respect to a reference, such as a ground plane.
Analog Circuit
21.0037
An electrical circuit that provides a continuous relationship between its input and output.
Analysis of Variance (ANOVA)
91.0038 The systematic method of statistically evaluating experimental results in order to separate the sources of variation.
Anchoring Spur
22.1325
An extension of a land on a flexible printed board that extends beneath the coverlayer to assist in holding the land to the base material. (See Figure A.3.)
Figure A.3 – Lands with anchoring spurs
Angled Bond
74.0039
The impression of the first and second bonds that are not in a straight line.
Anisotropic Conductive Contact 75.0675 An electrical connection using an anisotropic conductive film or paste wherein conductive particles of gold, silver, nickel, solder, etc. are dispersed. When it is compressed, an electrical connection is attained only in the direction of compression.
Anisotropy 40.0685 The condition for a substance having differing values for properties, such as permittivity, depending on the direction within the material.
Annotation
22.0040
Text, notes, or other identification, constructed by a computer-aided system, intended to be inserted on a drawing, map or diagram.
Annular Ring
(Annular Width)
60.0041
That portion of conductive material completely surrounding a hole. (See Figure A.4).
Figure A.4 – Annular ring (annular width)



60194  IEC:2006(E) – 9 –
Anode (BGA) 33.0689 The electrode from which the forward current flows within the device.
Anodic Cleaning
57.0042
Electrolytic cleaning in which the work is the anode.
Aperture (stencil) 73.0690 An opening in the stencil-foil.
Apparent Field-of-View Angle
92.0043 The angular subtense of the field-of-view in the image space of an optical system.
Application Specific Integrated Circuit
(ASIC)
33.0692 A semiconductor device intended to satisfy a unique complete circuit function.
Aqueous Flux
46.0044 See “Water Soluble Organic Flux”
Aramid
44.0045 See “Para-aramid”
Arc Resistance
92.0047 The resistance of a material to the effects of a high voltage, low current arc (under prescribed conditions) passing across the surface of the material. (The resistance is stated as a measure of total elapsed time at that voltage required to form a conductive path on the surface - material carbonized by the arc).
Architecture
11.0046 The structure of a computer's functional elements that makes it possess specific maximum and minimum capabilities.
Area Array 34.0751 A bonding pattern in which edge and additional pads on the inner surface area of the chip are addressed in the bonding scheme. (See Figure A.5).
Figure A.5 – Area array
Area Array Tape Automated
Bonding 74.0048 Tape automated Bonding where some carrier tape terminations are made to lands within the perimeter of the die.
Area Ratio
73.0758 The ratio of the area of aperture opening to the area of aperture walls.
Array
22.0049 A group of elements or circuits arranged in rows and columns on a base material.
Artificial Intelligence
11.0050 The capacity of a machine to perform functions that are normally associated with human intelligence, such as reasoning and learning.
Artwork
22.0051 An accurately-scaled configuration that is used to produce the "Artwork Master" or "Production Master”. (See Figure A.6.)
Artwork Master
24.0052 An accurately-scaled, usually 1:1, pattern that is used to produce the "Production Master”. (See Figure A.6.)
As-Fired
45.0054 The condition (values) of thick-film components or the smoothness of ceramic base materials, after they have been processed in a firing furnace and prior to trimming or polishing.
Aspect Ratio (Film)
74.0055
The ratio of the length of a film component to its width.
Aspect Ratio (Hole)
53.0056 The ratio of the length or depth of a hole to its preplated diameter.
(See Figure A.7.)
Figure A.7 – Aspect ratio (hole)



– 10 – 60194  IEC:2006(E)
Aspect Ratio (stencil)
73.0808 The ratio of the width of the aperture to the thickness of the stencil-foil.
Assembled Board
80.0057
See “Assembly”.
Assembly
80.1327 A number of parts, subassemblies or combinations thereof joined together. (Note: This term can be used in conjunction with other terms listed herein, e.g. "Printed Board Assembly”.)
Assembly Drawing
26.1328 A document that depicts the physical rela-tionship of two or more parts, a combination of parts and subordinate assemblies, or a group of assemblies required to form an assembly of a higher order.
Assembly Language
11.0058
A computer language made up of brief expressions that an assembler program can translate into a machine language.
Assembly Manufacturer
70.1911 The individual, organization, or company responsible for the assembly process and verification operations necessary to ensure full compliance of assemblies.
Assignable Cause
91.0059
See “Special Cause”.
Asymmetric Stripline
21.0060 A stripline signal conductor that is embedded, but not centreed, between two ground planes. (See Figure A.8).
Figure A.8 – Asymmetric stripline
Attachment Density 22.1823 The average number of surface mount or through hole solder joints, based on pitch and land size, that may be accommodated in a prescribed unit area e.g. cm2, considering land size within the unit area to accommodate solder joint attachment.
Attenuation
21.0061 The reduction in the amplitude of a signal due to losses in the media through which it is transmitted. The unit of measure is decibels (dB).



60194  IEC:2006(E) – 11 –
NOTE The term “original” may be used to preface any of the drafting and photographic-tooling terms used in this figure. The “original” is not usually used in manufacturing processes. In the event that a “copy” is made, the copy must be of sufficient accuracy to meet its intended purpose if it is to take on the name of any one of the terms used in this figure. Other adjectives may also be used to help describe the kind of copy, i.e. “nonstable”, “first generation,” “record,” etc. Figure A.6 – Simplified flow chart of printed board design/fabrication sequence



– 12 – 60194  IEC:2006(E)
Attributes Data
94.0062 Qualitative data that can be counted for recording and analysis purposes.
Automated Component Insertion
72.0063 The act or operation of assembling discrete components to printed boards by means of electronically-controlled equipment.
Automatic Component Placement
22.0029 Software that automatically optimizes the layout of components on a printed board.
Automatic Conductor Routing
22.0124 Software that automatically determines the placement of interconnections on a printed board.
Automatic Dimensioning
25.1329 A computer-aided drafting function that automatically generates dimensions, leaders, arrowheads, etc., that make up a complete set of documented dimensions.
Automatic Test Equipment
92.0064 Equipment that automatically analyses functional or static parameters in order to evaluate performance.
Automatic Test Generation
92.0065
Computer generation of a test program based solely on circuit topology with little or no manual programming effort.
Axial Lead
31.0067 Lead wire extending from a component or module body along its longitudinal axis.
(See Figure A.9).
Figure A.9 – Axial Lead
Azeotrope
49.0068 See “Azeotropic Mixture”
Azeotropic Mixture (Azeotrope)
49.1330 A liquid mixture of two or more substances that behaves like a single substance. The vapour produced by partial evaporization of the liquid has the same composition as the liquid.
B
B-Stage
41.1343 An intermediate stage in the reaction of a thermosetting resin in which the material softens when heated and swells, but does not entirely fuse or dissolve when it is in contact with certain liquids. (See also “C- Staged Resin”.)
B-Staged Material
41.0069 See “Prepreg”.
B-Staged Resin
41.0070 A thermosetting resin that is in an intermediate state of cure. (See also “C-Staged Resin”.)
Back Annotation
21.0072 The process of extracting appropriate information from a completed printed board design and inserting it on the boards schematic diagram.
Back Bonding
74.0073 Attaching a die to a base material with its circuitry facing away from the base material.
(See Figure B.1).
Figure B.1 – Back Bonding
Back Mounting
74.0079 See “Back Bonding”.
Back Taper(s)
51.0081 The constant decrease in diameter along the length of the body of a drill.
Back-Bared Land
22.0071 A land in flexible printed wiring that has a portion of the side normally bonded to the base dielectric material exposed by a clearance hole. (See Figure B.2).
Figure B.2 – Back-bared land



60194  IEC:2006(E) – 13 –
Backdriving
92.0074 An in-circuit testing technique that drives digital circuitry outputs to a given logic level, by supplying pulses of sufficient electrical current magnitude in parallel with the outputs, in order to overdrive the logic state conditions of the next digital device inputs.
Backfill
36.0075 Filling a hybrid circuit package with a dry inert gas prior to hermetic sealing.
Background (Artwork)
22.0076 The nonfunctional area of a phototool.
Background Variable
94.0077 A parameter of no experimental interest that is not held at a constant value.
Backlighting
24.0078 Viewing or photographing by placing an object between a light source and the eye or recording medium.
Backpanel
85.0080 See “Backplane”.
Backplane
85.1331 An interconnection device used to provide point-to-point electrical interconnections. (It is usually a printed board that has discrete wiring
terminals on one side and connector receptacles on the other side.) (See also “Mother Board”.)
Backup Pin 70.0972 A supporting pin that is located under a printed board to prevent deflection of the board during component mounting.
Backward Crosstalk
21.1332 Noise induced into a quiet line, as seen at
...

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