1、BSI Standards PublicationPrinted board assembliesPart 2: Sectional specification Requirements for surface mount soldered assembliesBS EN 61191-2:2013National forewordThis British Standard is the UK implementation of EN 61191-2:2013. It isidentical to IEC 61191-2:2013. It supersedes BS EN 61191-2:199
2、9 which iswithdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee EPL/501, Electronic assembly technology 31.240Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy
3、 and Strategy Committee on 31 October 2013.Amendments issued since publicationAmd. No. Date Text affectedBRITISH STANDARDBS EN 61191-2:2013EUROPEAN STANDARD EN 61191-2 NORME EUROPENNE EUROPISCHE NORM October 2013 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normal
4、isation Electrotechnique Europisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B - 1000 Brussels 2013 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61191-2:2013 E ICS 31.190; 31.240 Su
5、persedes EN 61191-2:1998 English version Printed board assemblies - Part 2: Sectional specification - Requirements for surface mount soldered assemblies (IEC 61191-2:2013) Ensembles de cartes imprimes - Partie 2: Spcification intermdiaire - Exigences relatives lassemblage par brasage pour montage en
6、 surface (CEI 61191-2:2013) Elektronikaufbauten auf Leiterplatten - Teil 2: Rahmenspezifikation - Anforderungen an geltete Baugruppen in Oberflchenmontage (IEC 61191-2:2013) This European Standard was approved by CENELEC on 2013-07-10. CENELEC members are bound to comply with the CEN/CENELEC Interna
7、l 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 CEN-CENELEC Management Centre or to any CE
8、NELEC member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CENELEC member into its own language and notified to the CEN-CENELEC Management Centre has the same status as the offici
9、al versions. CENELEC members are the national electrotechnical committees of Austria, Belgium, Bulgaria, Croatia, Cyprus, the Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Ma
10、lta, the Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 61191-2:2013EN 61191-2:2013 - 2 - Foreword The text of document 91/1091/FDIS, future edition 2 of IEC 61191-2, prepared by IEC/TC 91 “Electronics assembly tec
11、hnology “ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 61191-2:2013. The following dates are fixed: latest date by which the document has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2014-04-10 latest dat
12、e by which the national standards conflicting with the document have to be withdrawn (dow) 2016-07-10 This document supersedes EN 61191-2:1998. EN 61191-2:2013 includes the following significant technical changes with respect to EN 61191-2:1998: IPC-A-610 on workmanship has been included as a normat
13、ive reference; some of the terminology used in the document has been updated; references to EN standards have been corrected; the use of lead-free solder paste and plating are addressed. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rig
14、hts. CENELEC and/or CEN shall not be held responsible for identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 61191-2:2013 was approved by CENELEC as a European Standard without any modification. BS EN 61191-2:2013- 3 - EN 61191-2:2013 Annex ZA (n
15、ormative) Normative references to international publications with their corresponding European publications The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For u
16、ndated 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 61191-1 2013 Printed board asse
17、mblies Part 1: Generic specification - Requirements for soldered electrical and electronic assemblies using surface mount and related assembly technologies EN 61191-1 2013 IPC-A-610E 2010 Acceptability of Electronic Assemblies - - BS EN 61191-2:2013 2 61191-2 IEC:2013 CONTENTS 1 Scope . 6 2 Normativ
18、e references . 6 3 Conventions . 6 4 General requirements . 6 5 Classification 6 6 Surface mounting of components 7 6.1 General . 7 6.2 Alignment requirements . 7 6.3 Process control . 7 6.4 Surface mounted component requirements 7 6.5 Flatpack lead forming 7 6.5.1 General . 7 6.5.2 Surface mounted
19、device lead bends 8 6.5.3 Surface mounted device lead deformation . 8 6.5.4 Flattened leads 8 6.5.5 Dual-in-line packages (DIPs) . 8 6.5.6 Parts not configured for surface mounting . 9 6.6 Small devices with two terminations 9 6.6.1 General . 9 6.6.2 Stack mounting 9 6.6.3 Devices with external depo
20、sited elements . 9 6.7 Lead component body positioning . 9 6.7.1 General . 9 6.7.2 Axial-leaded components . 9 6.7.3 Other components . 9 6.8 Parts configured for butt lead mounting . 9 6.9 Non-conductive adhesive coverage limits 10 7 Acceptance requirements . 10 7.1 General . 10 7.2 Control and cor
21、rective actions . 10 7.3 Surface soldering of leads and terminations 10 7.3.1 General . 10 7.3.2 Solder fillet height and heel fillets 10 7.3.3 Flat ribbon L and gull-wing leads . 13 7.3.4 Round or flattened (coined) leads 13 7.3.5 J leads. 15 7.3.6 Rectangular or square end components . 16 7.3.7 Cy
22、lindrical end cap terminations 17 7.3.8 Bottom only terminations . 18 7.3.9 Leadless chip carriers with castellated terminations . 19 7.3.10 Butt joints 20 7.3.11 Inward L-shaped ribbon leads 21 7.3.12 Flat lug leads . 22 7.4 General post-soldering requirements applicable to all surface-mounted asse
23、mblies 23 BS EN 61191-2:201361191-2 IEC:2013 3 7.4.1 Dewetting 23 7.4.2 Leaching 23 7.4.3 Pits, voids, blowholes, and cavities 23 7.4.4 Solder wicking . 23 7.4.5 Solder webs and skins . 23 7.4.6 Bridging . 23 7.4.7 Degradation of marking . 23 7.4.8 Solder spikes . 23 7.4.9 Disturbed joint . 23 7.4.1
24、0 Component damage 24 7.4.11 Open circuit, non-wetting . 24 7.4.12 Component tilting 24 7.4.13 Non-conducting adhesive encroachment 24 7.4.14 Open circuit, no solder available (skip) 24 7.4.15 Component on edge 24 8 Rework and repair 24 Annex A (normative) Placement requirements for surface mounted
25、devices . 26 Figure 1 Lead formation for surface mounted device 8 Figure 2 Fillet height 12 Figure 3 Flat ribbon L and gull-wing leads 13 Figure 4 Round or flattened (coined) lead joint . 14 Figure 5 J lead joint . 15 Figure 6 Rectangular or square end components . 16 Figure 7 Cylindrical end-cap te
26、rminations 17 Figure 8 Bottom only terminations 18 Figure 9 Leadless chip carriers with castellated terminations . 19 Figure 10 Butt joints . 20 Figure 11 Inward L-shaped ribbon leads 21 Figure 12 Flat lug leads . 22 Table 1 Surface mounted solder joint defects . 25 BS EN 61191-2:2013 6 61191-2 IEC:
27、2013 PRINTED BOARD ASSEMBLIES Part 2: Sectional specification Requirements for surface mount soldered assemblies 1 Scope This part of IEC 61191 gives the requirements for surface mount solder connections. The requirements pertain to those assemblies that are totally surface mounted or to the surface
28、 mounted portions of those assemblies that include other related technologies (e.g. through-hole, chip mounting, terminal mounting, etc.). 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For d
29、ated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 61191-1:2013, Printed board assemblies Part 1: Generic specification Requirements for soldered electrical and electronic assemblies using sur
30、face mount and related assembly technologies IPC-A-610E:2010, Acceptability of Electronic Assemblies 3 Conventions Unless otherwise specified by the user, the word “shall“ signifies that the requirement is mandatory. Deviations from any “shall“ requirement requires written acceptance by the user, e.
31、g. via assembly drawing, specification or contract provision. The word “should” is used to indicate a recommendation or guidance statement. The word “may” indicates an optional situation. Both “should” and “may” express non-mandatory situations. “Will” is used to express a declaration of purpose. 4
32、General requirements Clause 4 of IEC 61191-1:2013 is a mandatory part of this standard. Workmanship of surface mount assemblies shall meet the requirements of IPC-A-610E in accordance with the classification requirements of this standard. 5 Classification This standard recognizes that electrical and
33、 electronic assemblies are subject to classifications by intended end-item use. Three general end-product classes have been established to reflect differences in producibility, complexity, functional performance requirements, and verification (inspection/test) frequency. These are the following: Lev
34、el A: General electronic products Level B: Dedicated service electronic products BS EN 61191-2:201361191-2 IEC:2013 7 Level C: High performance electronic products The user of the assemblies is responsible for determining the level to which his product belongs. It should be recognized that there may
35、 be overlaps of equipment between levels. The contract shall specify the level required and indicate any exceptions or additional requirements to the parameters, where appropriate (see 4.3 of IEC 61191-1:2013). 6 Surface mounting of components 6.1 General This clause covers assembly of components th
36、at are placed on the surface to be manually or machine soldered and includes components designed for surface mounting as well as through-hole components that have been adapted for surface mounting technology. 6.2 Alignment requirements Sufficient process control at all stages of design and assembly
37、shall be in place to enable the post-soldering alignments and solder joint fillet controls specified in 7.3 to be achieved. Relevant factors affecting the requirements include land and conductor design, component proximities, component and land solderability, solder paste/adhesive quantity and align
38、ment and component placement accuracy. 6.3 Process control If suitable process controls are not in place to ensure compliance with 6.2 and the intent of Annex A, the detailed requirements of Annex A shall be mandatory. 6.4 Surface mounted component requirements The leads of lead surface mounted comp
39、onents shall be formed to their final configuration prior to mounting. Leads shall be formed in such a manner that the lead-to-body seal is not damaged or degraded and that they may be soldered into place by subsequent processes which do not result in residual stresses decreasing reliability. When t
40、he leads of dual-in-line packages, flatpacks, and other multilead devices become misaligned during processing or handling, they may be straightened to ensure parallelism and alignment prior to mounting, while maintaining the lead-to-body seal integrity. 6.5 Flatpack lead forming 6.5.1 General Leads
41、on opposite sides of surface mounted flatpacks shall be formed such that the non-parallelism between the base surface of the component and the surface of the printed board (i.e. component cant) is minimal. Component cant is permissible provided the final configuration does not exceed the maximum spa
42、cing limit of 2,0 mm (see Figure 1). BS EN 61191-2:2013 8 61191-2 IEC:2013 Figure 1 Lead formation for surface mounted device 6.5.2 Surface mounted device lead bends Leads shall be supported during forming to protect the lead-to-body seal. Bends shall not extend into the seal (see Figure 1). The lea
43、d-bend radius (R) shall be 1 T (T = nominal lead thickness). The angle of that part of the lead between the upper and lower bends in relation to the mounting land shall be 45 minimum and 90 maximum. 6.5.3 Surface mounted device lead deformation Lead deformation (unintentional bending) may be allowed
44、 when a) no evidence of a short circuit or potential short circuit exists, b) lead-to-body seal or weld is not damaged by the deformation, c) does not violate minimum electrical spacing requirement, d) top of lead does not extend beyond the top of body; preformed stress loops may extend above the to
45、p of the body; however, stand-off height limit shall not be exceeded, e) toe curl, if present on bends, shall not exceed two times the thickness of the lead (2 T), f) coplanarity limits are not exceeded. 6.5.4 Flattened leads Components with axial leads of round cross-section may be flattened (coine
46、d) for positive seating in surface mounting. If flattening is used, the flattened thickness shall be not less than 40 % of the original diameter. Flattened areas of leads shall be excluded from the 10 % deformation requirement in 6.5.3 of IEC 61191-1:2013. Flattened leads on opposite sides of a surf
47、ace mount part shall be formed such that the non-parallelism between the base surface of the component and the surface of the printed board (e.g., component cant) is minimal. 6.5.5 Dual-in-line packages (DIPs) Dual-in-line packages may be surface mounted provided the leads are configured to meet the
48、 mounting requirements for surface mounted loaded parts. The lead preparation operation shall be performed using die forming/cutting systems. Hand forming and trimming of leads are prohibited. IEC 1364/13 BS EN 61191-2:201361191-2 IEC:2013 9 6.5.6 Parts not configured for surface mounting Flatpacks
49、of the through-hole configuration, transistors, metal power packages, and other non-axial lead components shall not be surface mounted unless the leads are formed to meet the surface mounted device lead forming requirements. Such applications shall be agreed on between user and manufacturer. 6.6 Small devices with two terminations 6.6.1 General The detailed requirements for mounting of small devices with two lead terminations are defined in the following subclauses. 6.6.2
