EN 61191-2:2017

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Elektronikaufbauten auf Leiterplatten - Teil 2: Rahmenspezifikation - Anforderungen an gelötete Baugruppen in OberflächenmontageEnsembles de cartes imprimées - Partie 2: Spécification intermédiaire - Exigences relatives à l'assemblage par brasage pour montage en surfacePrinted board assemblies - Part 2: Sectional specification - Requirements for surface mount soldered assemblies31.190Sestavljeni elektronski elementiElectronic component assemblies31.180SORãþHPrinted circuits and boardsICS:Ta slovenski standard je istoveten z:EN 61191-2:2017SIST EN 61191-2:2018en01-januar-2018SIST EN 61191-2:2018SLOVENSKI
STANDARDSIST EN 61191-2:20141DGRPHãþD

EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM
EN 61191-2
October 2017 ICS 31.190; 31.240
Supersedes
EN 61191-2:2013
English Version
Printed board assemblies - Part 2: Sectional specification - Requirements for surface mount soldered assemblies (IEC 61191-2:2017)
Ensembles de cartes imprimées - Partie 2: Spécification intermédiaire - Exigences relatives à l'assemblage par brasage pour montage en surface (IEC 61191-2:2017)
Elektronikaufbauten auf Leiterplatten -
Teil 2: Rahmenspezifikation - Anforderungen an gelötete Baugruppen in Oberflächenmontage (IEC 61191-2:2017) This European Standard was approved by CENELEC on 2017-06-27. 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 CEN-CENELEC Management Centre or to any CENELEC 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 official 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, Malta, the Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization
Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17,
B-1000 Brussels © 2017 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members.
Ref. No. EN 61191-2:2017 E SIST EN 61191-2:2018

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) 2018-04-13 • latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2020-10-13
This document supersedes EN 61191-2:2013.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC shall not be held responsible for identifying any or all such patent rights.
Endorsement notice The text of the International Standard IEC 61191-2:2017 was approved by CENELEC as a European Standard without any modification. In the official version, for Bibliography, the following notes have to be added for the standards indicated:
IEC 60068-2-20 NOTE Harmonized as EN 60068-2-20. IEC 60068-2-58 NOTE Harmonized as EN 60068-2-58. IEC 61188-5-1 NOTE Harmonized as EN 61188-5-1. IEC 61188-5-2 NOTE Harmonized as EN 61188-5-2. IEC 61188-5-3 NOTE Harmonized as EN 61188-5-3. IEC 61188-5-4 NOTE Harmonized as EN 61188-5-4. IEC 61188-5-5 NOTE Harmonized as EN 61188-5-5. IEC 61188-5-6 NOTE Harmonized as EN 61188-5-6. IEC 61188-7 NOTE Harmonized as EN 61188-7. IEC 61189-2 NOTE Harmonized as EN 61189-2. IEC 61190-1-2 NOTE Harmonized as EN 61190-1-2. IEC 61193-1 NOTE Harmonized as EN 61193-1. IEC 61193-3 NOTE Harmonized as EN 61193-3. IEC 62326-1 NOTE Harmonized as EN 62326-1. IEC 62326-4 NOTE Harmonized as EN 62326-4. IEC 62326-4-1 NOTE Harmonized as EN 62326-4-1. ISO 9001 NOTE Harmonized as EN ISO 9001. SIST EN 61191-2:2018

(normative)
Normative references to international publications
with their corresponding European publications
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements 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 1 Where an International Publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies.
NOTE 2 Up-to-date information on the latest versions of the European Standards listed in this annex is available here: www.cenelec.eu.
Publication Year Title EN/HD Year
IEC 60194 -
Printed board design, manufacture and assembly - Terms and definitions EN 60194 -
IEC 61191-1 -
Printed board assemblies -
Part 1: Generic specification - Requirements for soldered electrical and electronic assemblies using surface mount and related assembly technologies EN 61191-1 -
IPC-A-610 -
Acceptability of Electronics Assemblies - -
IEC 61191-2 Edition 3.0 2017-05 INTERNATIONAL STANDARD
Printed board assemblies –
Part 2: Sectional specification – Requirements for surface mount soldered assemblies
INTERNATIONAL ELECTROTECHNICAL COMMISSION
ICS 31.190; 31.240
ISBN 978-2-8322-4322-0
– 2 – IEC 61191-2:2017 © IEC 2017 CONTENTS FOREWORD . 5 1 Scope . 7 2 Normative references . 7 3 Terms and definitions . 7 4 General requirements . 7 5 Surface mounting of components . 7 5.1 General . 7 5.2 Alignment requirements . 8 5.3 Process control . 8 5.4 Surface mounted component requirements . 8 5.5 Flatpack lead forming . 8 5.5.1 General . 8 5.5.2 Surface mounted device lead bends . 8 5.5.3 Surface mounted device lead deformation . 9 5.5.4 Flattened leads . 9 5.5.5 Dual-in-line packages (DIPs) . 9 5.5.6 Parts not configured for surface mounting . 9 5.6 Small devices with two terminations . 9 5.6.1 General . 9 5.6.2 Stack mounting . 9 5.6.3 Devices with external deposited elements . 9 5.7 Lead component body positioning . 10 5.7.1 General . 10 5.7.2 Axial-leaded components . 10 5.7.3 Other components . 10 5.8 Parts configured for butt lead mounting . 10 5.9 Non-conductive adhesive coverage limits . 10 6 Acceptance requirements . 10 6.1 General . 10 6.2 Control and corrective actions . 10 6.3 Surface soldering of leads and terminations . 11 6.3.1 General . 11 6.3.2 Solder fillet height and heel fillets . 11 6.3.3 Flat ribbon L and gull-wing leads . 12 6.3.4 Round or flattened (coined) leads . 13 6.3.5 J leads . 14 6.3.6 Rectangular or square end component . 15 6.3.7 Cylindrical end-cap terminations . 16 6.3.8 Bottom only terminations . 17 6.3.9 Castellated terminations . 18 6.3.10 Butt joints . 19 6.3.11 Inward L-shaped ribbon leads . 20 6.3.12 Flat lug leads . 21 6.3.13 Ball grid array . 22 6.3.14 Column grid array . 23 6.3.15 Bottom termination components . 24 SIST EN 61191-2:2018

IEC 61191-2:2017 © IEC 2017 – 3 –
6.3.16 Components with bottom thermal plane terminations (D-Pak) . 24 6.3.17 P-style terminations . 26 6.4 General post-soldering requirements applicable to all surface-mounted assemblies . 26 6.4.1 Dewetting . 26 6.4.2 Leaching . 26 6.4.3 Pits, voids, blowholes, and cavities . 26 6.4.4 Solder wicking . 27 6.4.5 Solder webs and skins . 27 6.4.6 Bridging . 27 6.4.7 Degradation of marking . 27 6.4.8 Solder spikes . 27 6.4.9 Disturbed joint . 27 6.4.10 Component damage. 27 6.4.11 Open circuit, non-wetting . 27 6.4.12 Component tilting. 27 6.4.13 Non-conducting adhesive encroachment . 28 6.4.14 Open circuit, no solder available . 28 6.4.15 Component on edge . 28 7 Rework and repair . 28 Annex A (normative)
Placement requirements for surface mounted devices . 30 A.1 General . 30 A.2 Component positioning . 30 A.3 Small devices incorporating two terminations . 30 A.3.1 Metallization coverage over the land (side-to-side) . 30 A.3.2 Metallization coverage over the land (end) . 30 A.4 Mounting of cylindrical end-cap devices (MELFs) . 30 A.5 Registration of castellated chip carriers . 30 A.6 Surface mounted device lead and land contact . 30 A.7 Surface mounted device lead side overhang . 30 A.8 Surface mounted device lead toe overhang . 31 A.9 Surface mounted device lead height off land (prior to soldering) . 31 A.10 Positioning of J lead devices . 31 A.11 Positioning gull-wing lead devices . 31 A.12 External connections to packaging and interconnect structures . 31 Bibliography . 32
Figure 1 – Lead formation for surface mounted device . 8 Figure 2 – Fillet height . 12 Figure 3 – Flat ribbon 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 terminations . 17 Figure 8 – Bottom only terminations . 18 Figure 9 – Leadless chip carriers with castellated terminations . 19 Figure 10 – Butt joints . 20 SIST EN 61191-2:2018

– 4 – IEC 61191-2:2017 © IEC 2017 Figure 11 – Inward L-shaped ribbon leads . 21 Figure 12 – Flat lug leads . 22 Figure 13 – BGA with collapsing balls . 23 Figure 14 – Bottom termination components . 24 Figure 15 – Bottom thermal plane terminations . 25 Figure 16 – P-style terminations . 26
Table 1 – BGA with non-collapsing balls . 23 Table 2 – Column grid array . 23 Table 3 – Reworkable defects . 29
IEC 61191-2:2017 © IEC 2017 – 5 –
INTERNATIONAL ELECTROTECHNICAL COMMISSION ____________
PRINTED BOARD ASSEMBLIES –
Part 2: Sectional specification –
Requirements for surface mount soldered assemblies
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 itself does not provide any attestation of conformity. Independent certification bodies provide conformity assessment services and, in some areas, access to IEC marks of conformity. IEC is not responsible for any services carried out by independent certification bodies. 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 61191-2 has been prepared by IEC technical committee 91: Electronics assembly technology. This third edition cancels and replaces the second edition published in 2013. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a) the requirements have been updated to be compliant with the acceptance criteria in IPC-A-610F; b) some of the terminology used in the document has been updated; c) references to IEC standards have been corrected; d) five termination styles have been added. SIST EN 61191-2:2018

– 6 – IEC 61191-2:2017 © IEC 2017 The text of this International Standard is based on the following documents: CDV Report on voting 91/1386/CDV 91/1429/RVC
Full information on the voting for the approval of this International Standard can be found in the report on voting indicated in the above table. This document has been drafted in accordance with the ISO/IEC Directives, Part 2. A list of all parts of IEC 61191 under the general title Printed board assemblies can be found in the IEC website. The committee has decided that the contents of this document will remain unchanged until the stability date indicated on the IEC website under "http://webstore.iec.ch" in the data related to the specific document. At this date, the document will be
• reconfirmed, • withdrawn, • replaced by a revised edition, or • amended. A bilingual version of this publication may be issued at a later date.
IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates that it contains colours which are considered to be useful for the correct understanding of its contents. Users should therefore print this document using a colour printer.
IEC 61191-2:2017 © IEC 2017 – 7 –
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 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 are referred to in the text in such a way that some or all of their content constitutes requirements 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 60194, Printed board design, manufacture and assembly – Terms and definitions IEC 61191-1, Printed board assemblies – Part 1: Generic specification – Requirements for soldered electrical and electronic assemblies using surface mount and related assembly technologies IPC-A-610, Acceptability of Electronic Assemblies 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60194 apply. ISO and IEC maintain terminological databases for use in standardization at the following addresses: • IEC Electropedia: available at http://www.electropedia.org/ • ISO Online browsing platform: available at http://www.iso.org/obp 4 General requirements The requirements of IEC 61191-1 are a mandatory part of this specification. Workmanship shall meet the requirements of IPC-A-610 in accordance with the classification requirements of this document. 5 Surface mounting of components 5.1 General This clause covers assembly of components that 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. SIST EN 61191-2:2018

– 8 – IEC 61191-2:2017 © IEC 2017 5.2 Alignment requirements Sufficient process control at all stages of design and assembly shall be in place to enable the post-soldering alignments and solder joint fillet controls specified in 6.3 to be achieved. Relevant factors affecting the requirements include land and conductor design, component proximities, component and land solderability, solder paste/adhesive quantity and alignment and component placement accuracy. 5.3 Process control If suitable process controls are not in place to ensure compliance with 5.2 and the intent of Annex A, the detailed requirements of Annex A shall be mandatory. 5.4 Surface mounted component requirements The leads of lead surface mounted components 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 the 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. 5.5 Flatpack lead forming 5.5.1 General Leads 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 spacing limit of 2,0 mm (see Figure 1).
Key R lead-bend radius T nominal lead thickness Figure 1 – Lead formation for surface mounted device 5.5.2 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 lead-bend radius (R) shall be > 1 T (T = nominal lead ≤ 2,0 mm 45° – 90° T No bend into the seal R R IEC SIST EN 61191-2:2018

IEC 61191-2:2017 © IEC 2017 – 9 –
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. 5.5.3 Surface mounted device lead deformation Lead deformation (unintentional bending) may be allowed 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 top 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. 5.5.4 Flattened leads Components with axial leads of round cross-section may be flattened (coined) 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 surface 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. 5.5.5 Dual-in-line packages (DIPs) Dual-in-line packages may be surface mounted provided the leads are configured to meet the 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. 5.5.6 Parts not configured for surface mounting Flatpacks 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. 5.6 Small devices with two terminations 5.6.1 General The detailed requirements for mounting of small devices with two lead terminations are defined in 5.6.2 and 5.6.3. 5.6.2 Stack mounting When part stacking is permitted by the assembly drawing, parts shall not bridge spacing between other parts or components such as terminals or other chip components. 5.6.3 Devices with external deposited elements Components with electrical elements deposited on an external surface (such as chip resistors) shall be mounted with that surface facing away from the printed board or substrate. SIST EN 61191-2:2018

– 10 – IEC 61191-2:2017 © IEC 2017 5.7 Lead component body positioning 5.7.1 General Parts mounted over protected surfaces and insulated parts that are positioned over circuitry or parts mounted over surfaces without exposed circuitry may be flush mounted (i.e. no stand-off height). Parts mounted over exposed circuitry shall have their leads formed to provide a minimum of 0,25 mm between the bottom of the component body and the exposed circuitry. The maximum clearance between the bottom of the leaded component body and the printed wiring surface shall not exceed 2,0 mm. 5.7.2 Axial-leaded components The body of a surface-mounted axial-leaded component shall be spaced from the surface of the printed board at a maximum of 2,0 mm unless the component is mechanically attached to the substrate by adhesive or other means. Leads on opposite sides of surface mounted axial-leaded components shall be formed such that component cant (non-parallelism between the base surface of the mounted component and the surface of the printed board) is minimal and in no instance shall body cant result in non-conformance with maximum spacing limits. 5.7.3 Other components TO-can devices, tall profile components (i.e. over 15 mm), transformers, and metal power packages may be surface mounted provided the parts are bonded or otherwise secured to the board in a manner which enables the part to withstand the end-item shock, vibration and environmental stresses. 5.8 Parts configured for butt lead mounting Components designed for through hole (pin-in-hole) applications and modified for butt joint attachment, or stiff leaded dual-in-line packages may be butt mounted on level A and B products. Butt mounting is not permitted on level C products unless the component is designed for surface mounting. Components with solder-charged terminations designed for butt mounting may be acceptable for all classes. For other butt-mounted termination components acceptance criteria have to be agreed between the manufacturer and the user. 5.9 Non-conductive adhesive coverage limits Non-conductive adhesive materials, when used for component mounting, shall not flow onto, or obscure, areas to be soldered or into vias or plated-through holes. 6 Acceptance requirements 6.1 General Materials, processes, and procedures described and specified in IEC 61191-1 provide for soldered interconnections that are better than the minimum surface mount acceptance requirements in this clause. Processes and their control should be capable of producing product meeting or exceeding the acceptance criteria for defined product levels. 6.2 Control and corrective actions The detailed requirements for acceptance, corrective action limits, control limit determination, and general assembly criteria described in IEC 61191-1 are a mandatory part of this standard. In addition 6.3 shall be met for all surface mount assembly and for connection acceptability. SIST EN 61191-2:2018

IEC 61191-2:2017 © IEC 2017 – 11 –
6.3 Surface soldering of leads and terminations 6.3.1 General Solder joints or terminations on components designed for surface mounting shall exhibit solder joints that meet the general descriptions of Clause 10 of IEC 61191-1:2013 with the specific measurements defined in 6.3.3 to 6.3.17 of this document. Some surface-mounted components will self-align during reflow soldering but a degree of misalignment is permitted to the extent specified. However, minimum design conductor spacing shall not be violated. In 6.3.3 to 6.3.17, certain joint features are unspecified in size and the only requirement is that a properly wetted fillet to both lead/termination and lands be visible. Geometric dimensions not called out with any requirements are considered non-critical to the performance of the interconnection. Surface-mounted joints formed to connector, socket, and other leads or terminations without mechanical support, subjected to stress from insertion and withdrawal of components or printed boards, shall meet the requirements of level C. 6.3.2 Solder fillet height and heel fillets 6.3.2.1 General The height F of solder fillets, including heel fillets, as required in the following subclauses shall be judged by the distance the applied solder has risen up the joined surface. Figure 2 illustrates this measurement for joints of equal height but having different solder volume. In 6.3.3 to 6.3.12, for some lead configurations, the minimum acceptable fillet height criterion is referenced to the lead thickness T, or one half the thickness (0,5 T). When referenced to T, the height of the heel fillet to a formed lead shall be measured at the lowest point of the inside bend radius of the lead, as indicated by point A of Figure 2b (e.g. level C in Figures 3 to 5). When referenced to 0,5 T, the fillet may be 0,5 T lower (e.g. level B in Figures 3 to 5). NOTE Subclause 6.3.3 provides an organization that combines the requirement paragraph, the appropriate figure and a dimensional table that describes the specific details. 6.3.2.2 Solder connection contours A mounting technique shall be used to compensate for the coefficient of thermal expansion (CTE) mismatch of the part and board. This mounting technique shall be limited to part leads, specialized mounting devices, and normal solder connections. The use of specialized stand-offs mounted between the part and the land is permissible. Leadless components shall not be soldered into place using redundant interconnect wiring between the component castellation and the land. Designs that use special solder connection contours as part of a CTE mismatch compensation system shall be identified on the approval assembly drawing. The mounting technique shall be capable of performing with a solder connection which meets the requirements of this document. 6.3.2.3 Surface mount device lead heel position The heel of a leaded component shall not overhang the land. NOTE The heel begins where the lead starts to curve at the lead bend. 6.3.2.4 Break-away tie bars Components (e.g. connectors and flexible circuits) which incorporate break-away tie bars in their design may be installed or soldered in place prior to removal of the tie bar. Exposed basis metal resulting from tie bar removal is permissible. SIST EN 61191-2:2018

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a) Fillet height
b) Fillet height referenced to lead thickness Key A lowest point of inside bend radius F fillet height L projected lead length T lead thickness Figure 2 – Fillet height 6.3.3 Flat ribbon L and gull-wing leads Solder joints between substrate lands and flat ribbon leads formed into an L, and gull-wing shaped component leads of either stiff or flexible materials shall meet the alignment and solder fillet requirements of Figure 3 for each product level. IEC F F A T
A = lowest point of inside
bend radius
L = projected lead length L L T = lead thickness
IEC F F = fillet height SIST EN 61191-2:2018

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Dimensions in millimetres Feature Dimension Level A Level B Level C Maximum side overhang A ½W or 0,5 mm,d whichever is less ½W or 0,5 mm,d whichever is less ¼W or 0,5 mm,d whichever is less Maximum toe overhang B d Not permitted when L < 3W d Not permitted when L < 3W d Minimum end joint width c C ½W ½W ¾W Minimum side joint length b When L ≥ 3W D W or 0,5mm, whichever is less 3W or ¾L, whichever is longer When L < 3W L Maximum heel fillet height E f Minimum heel fillet height T ≤ 0,4 mm F e G + T G + T f T > 0,4 mm G + ½T Minimum solder thickness G e e e a Solder fillets for levels A and B may extend through the top bend. b Leads not having wettable sides or ends by design (such as leads stamped or sheared from prepared stock) are not required to have side or end fillets, but side overhang is not permitted (all levels). c, d Shall not violate minimum design conductor spacing. e Properly wetted fillet evident. f Solder does not touch body or end seal. g In case of toe down configuration, minimum fillet height F extends at least to the mid-point of the outside lead bend. Figure 3 – Flat ribbon and gull-wing leads 6.3.4 Round or flattened (coined) leads Joints formed to round or flattened (coined) leads shall meet the dimensional and fillet requirements of Figure 4 for each product level. IEC L A B W G W A C Lead Land Side overhang Toe overhang End joint width Others lead configurations W L B E F T G G G T T E F D F D See notea of the table D = side joint length W = lead width T = lead thickness Toe down heel fillet height Center line of T Line bisecting lower bend radius See Note g of the table L = formed foot length SIST EN 61191-2:2018

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Dimensions in millimetres Feature Dimension Level A Level B Level C Maximum side overhang A ½W or 0,5 mm, whichever is less b ¼W or 0,5 mm, whichever is less b Maximum toe overhang B b b b Minimum end joint width C c c ¾W Minimum side joint length D W 1½W Maximum heel fillet height E a a a Minimum heel fillet height F c G + ½T d G + T d Minimum solder thickness G c c c Minimum side joint height Q c G + ½T G + ½T a Solder does not touch package body or seal. b Shall not violate minimum design conductor spacing. c Properly wetted fillet evident. d In case of toe down configuration, minimum heel fillet height F extends at least to the mid-point of the outside lead bend Figure 4 – Round or flattened (coined) lead joint 6.3.5 J leads Joints formed to leads having a J shape at the joint site shall meet the dimensional and fillet requirements of Figure 5 for each product level. IEC L A B G W A C Side overhang Toe overhang End joint width Others land configurations E F T G F D See notea of the table Side joint length W
= flattened lead width or
diameter of round lead T
= thickness of lead at joint
site (cover land) L = formed foot length Toe down heel
fillet height Line bisecting lower bend
radius W Q G Q A A C SIST EN 61191-2:2018

IEC 61191-2:2017 © IEC 2017 – 15 –
Dimensions in millimetres Feature Dimension Level A Level B Level C Maximum side overhang f A ½W ½W ¼W Maximum toe overhang B b d b d b d Minimum end joint width C ½W ¾W Minimum side joint length e D c 1½W 1½W Maximum fillet height E a a a Minimum fillet height F G + ½T G + T Minimum solder thickness G c c c a Maximum solder fillet does not touch package body or end seal. b Unspecified parameter. c Properly wetted fillet evident. d Shall not violate minimum design conductor spacing. Figure 5 – J lead joint 6.3.6 Rectangular or square end component Solder joints to components having terminations of a square or rectangular configuration shall meet the dimensional and solder fillet requirements of Figure 6 for each product level. IEC A B Side overhang Toe overhang End joint width E F T G D See notea of the table Side joint length W
= lead width
T
= lead thickness
A C T W G Land Lead W SIST EN 61191-2:2018

– 16 – IEC 61191-2:2017 © IEC 2017
Dimensions in millimetres Feature Dimension Level A Level B Level C Maximum side overhang e A ½W or P, whichever is less ¼W or P, whichever is less End overhang B Not permitted Minimum end joint width C ½W or P, whichever is less ¾W or P, whichever is less Minimum side joint length c D d Maximum fillet height a E a Minimum fillet height F d G + ¼H or G + 0,5, whichever is less Minimum solder thickness b G d Minimum end overlap c J required ¼T a The maximum fillet may overhang the land or extend onto the top of the end-cap metallization; however, the solder shall not extend further onto the component body. b Unless satisfactory cleaning can be demonstrated with reduced clearance. G is not specified when cleaning is not required. c Not required for one face only termination type components. d Properly wetted fillet evident. e Shall not violate minimum design conductor spacing. Figure 6 – Rectangular or square end components 6.3.7 Cylindrical end-cap terminations Solder joints to components having cylindrical end-cap terminations (e.g. MELFs) shall meet the dimensional and solder fillet requirements of Figure 7 for each product level. IEC A B Side overhang of termination End overhang End joint width E F T D See notea of the table H = height of termination zone W
= width of termination area C W G W H F P P A H G J W W W Five face termination Three face termination One or two-sided termination End overlap Termination configurations T = length of termination zone P
= width of land SIST EN 61191-2:2018

IEC 61191-2:2017 © IEC 2017 – 17 –
Dimensions in millimetres Feature Dimension Level A Level B Level C Maximum side overhang c A ¼W or P, whichever is less End overhang B Not permitted Minimum end joint width C b ½W or P, whichever is less Minimum side joint length D b ½T or S, whichever is less ¾T or S, whichever is less Maximum fillet height
(end and side) E a Minimum fillet height
(end and side) F b G + ¼W or G =+ 1,0 mm, whichever is less Minimum solder thickness G b Minimum end overlap J b ¼T ¾T a The maximum fillet may overhang the land or extend onto the top of the end-cap metallization; however, the solder shall not extend further onto the component body. b Properly wetted fillet evident. c Shall not violate minimum design conductor spacing. Figure 7 – Cylindrical end-cap terminations 6.3.8 Bottom only terminations Discrete chip components, leadless chip carriers, and other devices having metallized terminations on the bottom side only shall meet the dimensional and solder fillet requirements of Figure 8 for each product level. IEC A B Side overhang
End overhang End joint width E F T D See notea of the table W
= diameter of termination T = termination / plating length S = land length C W F P A G J Side joint length and end overlap S SIST EN 61191-2:2018

– 18 – IEC 61191-2:2017 © IEC 2017
Dimensions in millimetres
Feature Dimension Level A Level B Level C Maximum side overhang A ½W or P, whichever is less d
¼W or P, whichever is less d End overhang B Not permitted Minimum end joint width C ½W or P, whichever is less ¾W or P, whichever is less Minimum side joint length D a a a Maximum fillet height E a a a Minimum fillet height F a a a Minimum solder thickness c G b b b Minimum end overlap J b ½T ¾T a Unspecified parameter. b Properly wetted fillet evident. c If cleaning is required, G is not specific as long as satisfactory cleaning can be demonstrated with reduced clearance.
d Shall not violate minimum design conductor spacing. Figure 8 – Bottom only terminations 6.3.9 Castellated terminations Joints formed to castellated terminations of leadless chip carriers shall meet the dimensional and solder fillet requirements of Figure 9 for each product level. IEC A B Side overhang
End overhang End joint width D W
= terminati
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