1、BRITISH STANDARDBS EN 61193-2:2007Quality assessment systems Part 2: Selection and use of sampling plans for inspection of electronic components and packagesThe European Standard EN 61193-2:2007 has the status of a British StandardICS 31.190g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g5
2、4g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58BS EN 61193-2:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 December 2007 BSI 2007ISBN 978 0
3、 580 55333 2National forewordThis British Standard is the UK implementation of EN 61193-2:2007. It is identical to IEC 61193-2:2007.The UK participation in its preparation was entrusted to Technical Committee EPL/501, Electronic assembly technology.A list of organizations represented on this committ
4、ee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.Amendments issued since publicati
5、onAmd. No. Date CommentsEUROPEAN STANDARD EN 61193-2 NORME EUROPENNE EUROPISCHE NORM November 2007 CENELEC European Committee for Electrotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35,
6、 B - 1050 Brussels 2007 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref. No. EN 61193-2:2007 E ICS 31.190 English version Quality assessment systems - Part 2: Selection and use of sampling plans for inspection of electronic components and
7、 packages (IEC 61193-2:2007) Systme dassurance de la qualit - Partie 2: Choix et utilisation des plans dchantillonnages pour le contrle des composants lectroniques et des botiers (CEI 61193-2:2007) Qualittsbewertungssysteme - Teil 2: Auswahl und Anwendung von Stichprobenanweisungen fr die Prfung ele
8、ktrischer Bauelemente und Gehuse (IEC 61193-2:2007) This European Standard was approved by CENELEC on 2007-11-01. 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 a
9、ny 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 three official versions (English, French, German). A version in any other language ma
10、de 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, Bulgaria, Cyprus, the Czech Republic, Denmark,
11、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. Foreword The text of document 91/690/FDIS, future edition 1 of
12、 IEC 61193-2, prepared by IEC TC 91, Electronics assembly technology, was submitted to the IEC-CENELEC parallel vote and was approved by CENELEC as EN 61193-2 on 2007-11-01 The following dates were fixed: latest date by which the EN has to be implemented at national level by publication of an identi
13、cal national standard or by endorsement (dop) 2008-08-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2010-11-01 Annex ZA has been added by CENELEC. _ Endorsement notice The text of the International Standard IEC 61193-2:2007 was approved by CENELEC
14、as a European Standard without any modification. _ EN 61193-2:2007 2 CONTENTS INTRODUCTION.4 1 Scope.5 2 Normative references .5 3 Terms and definitions .5 4 Sampling system 6 4.1 Formation and identification of lots6 4.2 Drawing of samples.6 4.2.1 Selection of sample items6 4.2.2 Process of samplin
15、g 6 4.3 Sampling plans6 4.3.1 Inspection level .6 4.3.2 Sampling plan for normal inspection 7 4.3.3 Acceptance number.7 4.3.4 Tightened or reduced inspection7 5 Acceptance and rejection .8 5.1 Acceptability criteria 8 5.2 Disposition of rejected lots 8 6 Statistical verified quality limit (SVQL)8 6.
16、1 General .8 6.2 Calculation of the SVQL 9 Annex A (informative) Estimation of the statistical verified quality limit (SVQL) in nonconforming items per million (10-6) at a confidence limit 60 %.10 Annex B (informative) Relationship between this standard and ISO 2859-114 Annex C (informative) Example
17、 of application of this standard (lot-by-lot inspection of assessment level EZ in IEC/TC 40).16 Bibliography17 Table 1 Sample size 7 Table 2 Sample size code letters .8 Table 3 Coefficients for confidence level 60 % (see also A.5) 9 Table A.1 Statistical verified quality limits in nonconforming item
18、s per million (10-6) 11 Table A.2 np with confidence limit of 60 % for accumulated number of non-conforming items and coefficient CL.13 Table B.1 Sampling plans corresponding to Table 2-A of ISO 2859-1.14 Table B.2 Tabulated values for operating characteristic curves (p: per cent nonconforming).15 T
19、able C.1 Lot-by-lot inspection of assessment level EZ IEC/TC 40 .16 EN 61193-2:2007 3 Annex ZA (normative) Normative references to international publications with their corresponding European publications 18 INTRODUCTION To obtain a high quality level of products, process controls like 100 % testing
20、 of significant characteristics and statistical methods are needed to stabilize, monitor, and improve processes. Sampling inspection is one of the methods to verify whether the process control is effective, and the quality level of a suppliers product by a customer or third party. Today the quality
21、level of products for use in electric and electronic equipment is expected to be equal or close to zero defects. But, the assessment of a quality level close to zero defects by sampling only would lead to an unreasonable increase of cost for inspection. A combination of process control and zero acce
22、ptance number sampling plans is indispensable. This standard provides a sampling system and plans for the inspection of electronic components, packages and modules, manufactured under suitable process control, which prevents the outflow of nonconforming products. NOTE The sampling system provided by
23、 this standard is extracted from ISO 2859-1, and is intended to be used for the inspection of final products, either by the manufacturer, a customer, or a third party. EN 61193-2:2007 4 QUALITY ASSESSMENT SYSTEMS Part 2: Selection and use of sampling plans for inspection of electronic components and
24、 packages 1 Scope This part of IEC 61193 applies to the inspection of electronic components, packages, and also modules (referred to as “products” in this standard) for use in electronic and electric equipment. It specifies sampling plans for inspection by attributes on the assumption that the accep
25、tance number is zero (Ac = 0), including criteria for sample selection and procedures. The zero acceptance number sampling plans provided by this standard apply to the inspection of products, that are manufactured under suitable process control with the target of a “zero-defect” quality level before
26、 sampling inspection. In addition, this standard provides a method for the calculation of the expected value of the statistical verified quality limit (SVQL) at a confidence level of 60 %. Amongst other things, this method can be used to verify the effectiveness of the suppliers process control. NOT
27、E In this standard the term “module” is used for products which are modules according to the definition in IEC 60194. 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 re
28、ferences, the latest edition of the referenced document (including any amendments) applies. IEC 60194: Printed board design, manufacture and assembly Terms and definitions ISO 2859-1:1999, Sampling procedures for inspection by attributes Part 1: Sampling schemes indexed by acceptance quality limit (
29、AQL) for lot-by-lot inspection ISO 3534-2:2006, Statistics Vocabulary and symbols Part 2: Applied statistics 3 Terms and definitions For the purposes of this document, the terms and definitions given in IEC 60194, ISO 2859-1 and ISO 3534-2, as well as the following, apply. 3.1 electronic component i
30、ndividual component which includes electronic, optoelectronic and/or micro-electro-mechanical systems (MEMS) element 3.2 electronic package individual electronic element or elements in a container which protects the contents to assure the reliability and provides terminals to interconnect the contai
31、ner to an outer circuit EN 61193-2:2007 5 3.3 electronic module functional block which contains individual electronic elements and /or electronic packages, to be used in a next level assembly 3.4 inspection level IL level to define sample size for lot size NOTE Sample size of lots depends on the sev
32、erity of inspection level. 3.5 nonconforming item item with one or more nonconformities NOTE A nonconforming item is a product which cannot satisfy the requirement (visual examination or electrical performance, etc.) in the lot-by-lot inspection or periodic test, etc. 3.6 structurally similar produc
33、ts products manufactured by the same manufacturer with the same materials, manufacturing processes and methods NOTE Products are structurally similar, even when there are differences e.g. in case size and rated values. Results from designated tests conducted on items of one lot of these products can
34、 be accumulated with results of other lots in the same group of structural similarity. 4 Sampling system The procedure and sampling plans described in this clause are based on an acceptance number zero (Ac = 0). 4.1 Formation and identification of lots The products shall be assembled into identifiab
35、le lots or sub-lots. Each lot shall, as far as practicable, consist of items of a single type, grade, class, size and composition, manufactured under uniform conditions at essentially the same time. 4.2 Drawing of samples 4.2.1 Selection of sample items The items selected for the sample shall be dra
36、wn from the lot by simple random sampling (see 3.1.3.4 in ISO 3534-2). However, when the lot consists of sub-lots or strata, identified by some rational criterion, stratified sampling shall be used in such a way that the size of the subsample from each sublot or stratum is proportional to the size o
37、f that sublot or stratum. 4.2.2 Process of sampling Samples may be drawn after the lot has been produced, or during production of the lot. 4.3 Sampling plans 4.3.1 Inspection level The inspection level designates the relative severity of inspection. Three inspection levels, I, II and III, are given
38、for general use. Unless otherwise specified, level II shall be used. Level I may be used when less discrimination is needed or level III when greater discrimination is required. Four additional special levels, S-1, S-2, S-3 and S-4 may be used where relatively EN 61193-2:2007 6 small sizes are neces
39、sary and larger sampling risks can be tolerated, such as destructive inspection or valuable products. The inspection level shall be specified in accordance with the detail specification or an agreement with a supplier and a user. 4.3.2 Sampling plan for normal inspection Unless otherwise specified i
40、n the detail specification, single sampling plans for normal inspection according to Table 1 of this standard shall be applied (see also Annex B). NOTE Table 1 is adapted from ISO 2859-1. Table 1 Sample size Special inspection levels General inspection levels Lot size S-1 S-2 S-3 S-4 2 to 8 2 2 2 2
41、2 2 3 9 to 15 2 2 2 2 2 3 5 16 to 25 2 2 3 3 3 5 8 26 to 50 2 3 3 5 5 8 13 51 to 90 3 3 5 5 5 13 20 91 to 150 3 3 5 8 8 20 32 151 to 280 3 5 8 13 13 32 50 281 to 500 3 5 8 13 20 50 80 501 to 1 200 5 5 13 20 32 80 125 1 201 to 3 200 5 8 13 32 50 125 200 3 201 to 10 000 5 8 20 32 80 200 315 10 001 to
42、35 000 5 8 20 50 125 315 500 35 001 to 150 000 8 13 32 80 200 500 800 150 001 to 500 000 8 13 32 80 315 800 1 250 500 001 8 13 50 125 500 1 250 2 000 4.3.3 Acceptance number The acceptance number (Ac) shall be zero and the rejection number (Re) shall be 1. 4.3.4 Tightened or reduced inspection When
43、tightened inspection or reduced inspection is applied, Table 2 shall be used to select the applicable code letter for the particular lot size and the prescribed inspection level (see ISO 2859-1, Table 1). Then, sample size shall be determined from ISO 2859-1, Table 2-B (tightened inspection) or Tabl
44、e 2C (reduced inspection) by the corresponding sample size code letter. EN 61193-2:2007 7 Table 2 Sample size code letters Special inspection levels General inspection levels Lot size S-1 S-2 S-3 S-4 2 to 8 A A A A A A B 9 to 15 A A A A A B C 16 to 25 A A B B B C D 26 to 50 A B B C C D E 51 to 90 B
45、B C C C E F 91 to 150 B B C D D F G 151 to 280 B C D E E G H 281 to 500 B C D E F H J 501 to 1 200 C C E F G J K 1 201 to 3 200 C D E G H K L 3 201 to 10 000 C D F G J L M 10 001 to 35 000 C D F H K M N 35 001 to 150 000 D E G J L N P 150 001 to 500 000 D E G J M P Q 500 001 D E H K N Q R 5 Acceptan
46、ce and rejection 5.1 Acceptability criteria The lot shall be accepted only if no nonconforming items are found upon inspection according to Clause 4. 5.2 Disposition of rejected lots The responsible authority of the manufacturer shall decide how the rejected lots should be disposed. Such lots may be
47、 scrapped, sorted (with or without nonconforming items being replaced), reworked, re-evaluated against more specific usability criteria, or held for additional information, etc. When the inspection results are used to calculate the statistical verified quality limit (SVQL) according to Clause 6, the
48、 complete sample shall be inspected to obtain correct statistical data. NOTE Nonconforming lots indicate weak points in process control. The cause of nonconformities should be determined and appropriate corrective action implemented. 6 Statistical verified quality limit (SVQL) 6.1 General The observ
49、ation of zero nonconformities in a sample does not imply that the population has no nonconformities. The following method describes how to estimate the average production quality with a certain statistical probability (confidence level). NOTE Though SVQL is calculated by accumulating the inspection results, including rejected lots, these rejected lots including nonconforming items in sample are not shipped. Thus the defect rate perceived by a customer is far below the value
