1、BRITISH STANDARD BS 6221-6: 1982 IEC 326-6: 1980 (Incorporating Amendment Nos.1 and2) Printed wiring boards Part 6: Specification for multilayer rigid printed boards UDC 621.3.049.75419BS6221-6:1982 This British Standard, having been prepared under the directionof the Electronic Components Standards
2、 Committee, was published underthe authority of the BoardofBSI and comes into effecton 29January1982 BSI 12-1999 The following BSI references relate to the work on this standard: Committee reference ECL/19 Draft for comment 81/27114 DC ISBN 0 580 12529 7 Cooperating organizations The Electronic Comp
3、onents Standards Committee, under whose direction this British Standard was prepared, consists of representatives from the following: British Electrical and Allied Manufacturers Association (BEAMA) Electricity Supply Industry in England and Wales* Electronic Components Industry Federation* Electroni
4、c Engineering Association* Institution of Electronic and Radio Engineers Ministry of Defence* National Supervising Inspectorate* Post Office* Society of British Aerospace Companies Limited* Telecommunications Engineering and Manufacturing Association (TEMA)* The organizations marked with an asterisk
5、 in the above list, together with the following, were directly represented on the Technical Committee entrusted with the preparation of this British Standard: Association of Circuit Technologists British Plastics Federation British Radio Equipment Manufacturers Association Electrical Research Associ
6、ation Institute of Metal Finishing Institution of Production Engineers Scientific Instrument Manufacturers Association Society of Motor Manufacturers and Traders Limited Amendments issued since publication Amd. No. Date of issue Comments 4978 June 1986 6703 April 1991 Indicated by a sideline in the
7、marginBS6221-6:1982 BSI 12-1999 i Contents Page Cooperating organizations Inside front cover National foreword ii 1 Introduction 1 2 Scope 1 3 Object 1 4 General 1 5 Test specimens 2 6 Relevant specification 2 7 Characteristics of printed boards 2 8 Composite test pattern 10 Figure 1 Composite test
8、pattern, pattern location 14 Figure 2 Length of defect 21 Figure 3 Examples of soldered holes 22 Table I Basic characteristics 3 Table II Additional characteristics 9 Publications referred to Inside back coverBS6221-6:1982 ii BSI 12-1999 National foreword This British Standard, published under the d
9、irection of the Electronic Components Standards Committee is identical with Publication326-6 “Specification for multi-layer printed boards” published in1980 and Amendment No.1 to that standard published in1983 by the International Electrotechnical Commission (IEC). This Part of this standard represe
10、nts a partial revision of BS4597:1970. When sufficient Parts of BS6221 are published, BS4597:1970 will be withdrawn. Terminology and conventions. The text of the International Standard has been approved as suitable for publication as a British Standard without deviation. Some terminology and certain
11、 conventions are not identical with those used in British Standards; attention is especially drawn to the following. In clause1 and1.1 where the words “IEC Publication326” and “IEC Publication326-6” appear, they should be read as “BS6221” and “BS6221-6” respectively. There is no British Standard cor
12、responding to IEC Publication194 “Terms and definitions for printed circuits”, referred to in clause8. The Technical Committee has reviewed the provisions of IEC194 and has decided that they are suitable for use with this standard. The remaining standards listed in1.2 have been given for information
13、 purposes only. A related British Standard for IEC249 is BS4584 “Metal-clad base materials for printed circuits”. Consideration will be given to implementing IEC326-1, IEC326-7 and IEC326-8 as British Standards when these International Standards have been published by IEC. Additional information. Am
14、endment No.1 to IEC Publication194 “Terms and definitions for printed circuits”, referred to in clause8, is not yet available. For ease of reference, the following definitions are those proposed for international adoption by the IEC in document52 (Central Office)248. a) Test pattern. A conductive pa
15、ttern used for carrying out a test. A test pattern may consist of: 1) a part of the conductive pattern on a production board (and used in the application of that printed board); or 2) a special test pattern particularly designed and prepared for the purpose of testing only. This (special) test patte
16、rn may be located: Cross-references International Standard Corresponding British Standard IEC 68 BS 2011 Basic environmental testing procedures IEC 97:1970 BS 5830:1979 Specification for grid system for printed circuits (Identical) BS 6221 Printed wiring boards IEC 326-2:1976 (and IEC326-2A:1980) BS
17、 6221-2:1982 Methods of test (Identical) IEC 326-3:1980 BS 6221-3:1982 Guide for the design and use of printed wiring boards (Identical) IEC 326-4:1980 BS 6221-4:1982 Method for specifying single and double sided printed wiring boards with plain holes (Identical) IEC 326-5:1980 BS 6221-5:1982 Method
18、 for specifying single and double sided printed wiring boards with plated-through holes (Identical)BS6221-6:1982 BSI 12-1999 iii i) on a test coupon (i.e.a portion of a printed board or a panel usually cut off prior to using the printed board, see IEC Publication194-05-03); or ii) on a separate test
19、 board (see IEC Publication194-05-02). b) Composite test pattern. A combination of two or more different test patterns. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with
20、 a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi to iv, pages1to22, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendmen
21、ts incorporated. This will be indicated in the amendment table on the inside front cover.iv blankBS6221-6:1982 BSI 12-1999 1 1 Introduction IEC Publication326 is applicable to printed boards, irrespective of their method of manufacture, when they are ready for the mounting of the components. It is d
22、ivided into separate parts covering information for the designer, recommendations for the specification writer, test methods and requirements for the various types of printed boards, for example single and double sided, multilayer and flexible printed boards. 1.1 Purpose of Part 6 IEC Publication326
23、-6 contains fundamental information on characteristics to be assessed and requirements for multilayer printed boards. 1.2 Associated IEC publications This standard shall be used in conjunction with the following IEC publications: 2 Scope This standard is applicable to multilayer printed boards irres
24、pective of their method of manufacture. It is intended as a basis on which agreements between purchaser and vendor can be made. The term “relevant specification” used herein refers then to such agreements. 3 Object To define the characteristics to be assessed, the test methods to be used and to esta
25、blish uniform requirements for judging properties and dimensions. 4 General The following tables contain all important characteristics and make reference to the appropriate tests to verify these characteristics. Unless otherwise specified, all of the tests listed in Table I, page3, shall be carried
26、out. Where the relevant specification specifically claims additional characteristics which require additional tests, the relevant tests shall be selected from Table II, page9. Where additional details for a test must be specified in the relevant specification, this is indicated by an asterisk in the
27、 relevant column. These details shall then be specified in accordance with IEC Publication326-2. The tables are not intended to prescribe a test sequence, the tests may be carried out in any sequence, unless otherwise specified. The sample quantity shall also be specified by the relevant specificati
28、on. 68: Basic Environmental Testing Procedures. 97: Grid System for Printed Circuits. 194: Terms and Definitions for Printed Circuits. 249: Metal-clad Base Materials for Printed Circuits. 326-1: Printed Boards, Part1: Instructions for the Specification Writer (under consideration). 326-2: Part 2: Te
29、st Methods. 326-3: Part 3: Design and the Use of Printed Boards. 326-4: Part 4: Specification for Single and Double Sided Printed Boards with Plain Holes. 326-5: Part 5: Specification for Single and Double Sided Printed Boards with Plated-through Holes. 326-7: Part 7: Specification for Flexible Prin
30、ted Boards without Through Connections (underconsideration). 326-8: Part 8: Specification for Double-sided Flexible Printed Boards with Through Connections (underconsideration).BS6221-6:1982 2 BSI 12-1999 5 Test specimens The tests shall preferably be carried out on production boards. Where the use
31、of test coupons is agreed, they shall be prepared in accordance with Sub-clause4.2 of IEC Publication326-2. A suitable test pattern is shown in Figure 1, page14. 6 Relevant specification The relevant specification contains all information necessary to define the printed board clearly and completely.
32、 The recommendations given in IEC Publication326-3 shall be followed. Care should be taken to avoid unnecessary requirements. Permissible deviations shall be stated where necessary and nominal values without tolerances or simple maxima or minima shall be given where sufficient. Where precise specifi
33、cations are necessary for certain areas or parts of the printed board only, they shall be applied and restricted to those areas or parts. If there are several possibilities of presentation, of tolerance classes, etc.,the selections given in IEC Publication326-3 shall be applied. 7 Characteristics of
34、 printed boards (Table I and Table II.) BS6221-6:1982 BSI 12-1999 3 Table I Basic characteristics Characteristics Test No. IEC Publication 326-2 Additional test details to be specified in the relevant specification Specimen of composite test pattern Requirements Remarks General examination Visual ex
35、amination Conformity, identification Appearance and workmanship Plated-through holes 1 1a 1c 1a a Complete composite test pattern Pattern, marking identification and material finishes shall comply with the relevant specification. There shall be no apparent defects The boards shall appear to have bee
36、n processed in a careful and workmanlike manner, in accordance with good current practice Plated-through holes shall be clean and free from inclusions of any sort that could affect component insertion and solderability Total area of the voids shall not exceed10% of the total wall area. The largest d
37、imension shall not exceed25% of the hole circumference in the horizontal plane and25% of the thickness of the board in the vertical plane Plated-through holes shall have no plating voids at the interface of the hole wall and the conductive pattern or internal layer ring The interface shall be consid
38、ered to extend into the hole below the surface of the board a distance of one and a half times the total copper thickness on the surface or to be two times the inner layer copper thickness at level of contact ring Resin smear at the edge of the clad-copper and the continuous plated copper is permitt
39、ed provided the smear does not interrupt electrical continuity There shall be no circumferential cracks of the copper, or circumferential separation of the copper from the wall in the plated-through hole Holes with plating voids shall not exceed5% of the total number of plated-through holes Conducto
40、r defects 1b There shall be no cracks nor breaks. Imperfections such as voids or edge defects are permissible provided the conductor width or the leakage path between conductors is not reduced by more than specified in the relevant specification, for example20% or35% Where necessary, this shall be v
41、erified by dimensional examination, using Test2a a See the third paragraph of Clause4.BS6221-6:1982 4 BSI 12-1999Table I Basic characteristics Characteristics Test No. IEC Publication 326-2 Additional test details to be specified in the relevant specification Specimen of composite test pattern Requi
42、rements Remarks Particles between conductors Solder resist Dimensional examination Board dimensions Board thickness in the zone of edge board contacts Holes Slots, notches 1b or 1c 1a 2 2 2 2 a F K Residual metallic particles are permissible provided the leakage path is not reduced by more than20% o
43、r to less than the distance required for the circuit voltages The solder resist pattern shall comply with the relevant specification. There shall be no apparent defects Imperfections in the solder resist on the base material such as pinholes, small uncovered areas, scratches,etc.,are permitted, unle
44、ss otherwise specified in the relevant specification The top surface of the conductor shall be covered and substantially free of pinholes. At least one of two adjacent conductor edges shall be covered Component holes and contacts shall be free from solder resist Lands shall be free from solder resis
45、t, unless otherwise specified in the relevant specification Board edges and the areas near slots, notches, etc.,shall be free from solder resist if specified in the relevant specification Dimensions and tolerances shall comply with the relevant specification The nominal board thickness shall comply
46、with the relevant specification The total board thickness and the tolerances shall comply with the relevant specification Nominal diameter and tolerances of mounting holes and of component holes shall comply with the relevant specification The nominal diameter of plated-through holes used for throug
47、h connections only shall comply with the relevant specification The dimensions shall comply with the relevant specification Where necessary, this shall be verified by dimensional examination, using Test2a Total board thickness and tolerances shall be specified in accordance with Amendment No.1 to IE
48、C Publication321 A recommended range of hole sizes and tolerances is given in IEC Publication326-3 Accurate measurement is not necessary since deviations are not important a See the third paragraph of Clause4.BS6221-6:1982 BSI 12-1999 5Table I Basic characteristics Characteristics Test No. IEC Publi
49、cation 326-2 Additional test details to be specified in the relevant specification Specimen of composite test pattern Requirements Remarks Complete composite test pattern Conductor width 2 The width shall comply with any specific dimensions given in the relevant specification If no tolerances are stated, the coarse deviations given in IEC Publication326-3 shall apply Spacing between conductors 2a 2 F Imperfections such as voids or edge defects are permissible, provided the conductor width is not reduced by more than specified in the relevant specification
