SAE AS 6171 1-2016 Suspect Counterfeit Test Evaluation Method.pdf

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3、cation may be reproduced, stored in a retrieval system or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of SAE.TO PLACE A DOCUMENT ORDER: Tel: 877-606-7323 (inside USA and Canada)Tel: +1 724-776-4970 (out

4、side USA)Fax: 724-776-0790Email: CustomerServicesae.orgSAE WEB ADDRESS: http:/www.sae.orgSAE values your input. To provide feedback on thisTechnical Report, please visithttp:/standards.sae.org/AS6171/1AEROSPACESTANDARDAS6171/1Issued 2016-10Suspect/Counterfeit Test Evaluation MethodRATIONALEThis docu

5、ment is intended to provide guidance and requirements for the test laboratory in the evaluation of counterfeit parts detection testing performed by the test laboratory. This evaluation includes the determination of the Counterfeit Defect Coverage (CDC), the Counterfeit Type Coverage (CTC), the Under

6、-Covered Defects (UCD), and the Not-Covered Defects (NCD). A method is also described to select a sequence of tests for a given resource utilization.INTRODUCTIONMany test plans have been developed by organizations to screen for counterfeit parts. There is a need to evaluate the effectiveness of diff

7、erent test plans to provide a common comparison of testing deployments utilized by different organizations. This document provides a framework to assess a test plan to report CDC, CTC, NCDs, and UCDs which measure the effectiveness of the specified test plan for counterfeit parts detection. TABLE OF

8、 CONTENTS1. SCOPE 32. Applicable Documents 32.1 SAE Publications. 33. REQUIREMENTS . 33.1 Key Elements 33.2 Test Sequence Evaluation 53.2.1 Test Sequence Evaluation Example 1 63.2.2 Test Sequence Evaluation Example 2 83.3 Optimized Test Sequence Selection. 103.3.1 Optimized Test Sequence Selection E

9、xample 1. 114. RESULTANT EVALUATION AND REPORTING 144.1 Using the CDC Model . 144.1.1 An Implementation of the CDC Model 145. NOTES 165.1 Revision Indicator 16APPENDIX A DEFECTS TAXONOMY CHART AND DESCRIPTION 17APPENDIX B DEFECTS DETECTABILITY BY TEST METHODS . 23APPENDIX C COUNTERFEIT TYPE WEIGHTIN

10、G TABLE 33SAE INTERNATIONAL AS6171/1 Page 2 of 34TABLE 1 TARGET CONFIDENCE VALUES . 4TABLE 2 DECISION INDEX. 4TABLE 3 TEST SEQUENCE EVALUATION FOR A TEST PLAN . 6TABLE 4 SIMPLIFIED APPENDIX B TABLE. 6TABLE 5 SIMPLIFIED WEIGHTING AND DECISION INDEX TABLE. 6TABLE 6 EXAMPLE 1 TEST SEQUENCE EVALUATION.

11、7TABLE 7 SIMPLIFIED APPENDIX B TABLE. 8TABLE 8 SIMPLIFIED WEIGHTING AND DECISION INDEX TABLE. 8TABLE 9 EXAMPLE 2 TEST SEQUENCE EVALUATION. 9TABLE 10 OPTIMIZED TEST SEQUENCE SELECTION 11TABLE 11 SIMPLIFIED APPENDIX B TABLE. 12TABLE 12 SIMPLIFIED WEIGHTING AND DECISION INDEX TABLE. 12TABLE 13 EXAMPLE

12、1 OPTIMIZED TEST SEQUENCE SELECTION 12TABLE 14 OPTIMIZED TEST SEQUENCE SELECTION, CRITICAL RISK, ACTIVE COMPLEX PART . 15TABLE 15 TEST SEQUENCE EVALUATION, CRITICAL RISK, COMPLEX ACTIVE PART, RUN OF JUST AM TEST METHOD 15SAE INTERNATIONAL AS6171/1 Page 3 of 341. SCOPEThis document describes an asses

13、sment of the effectiveness of a specified test plan used to screen for counterfeit parts. The assessment includes the determination of the types of defects detected using a specified test plan along with the relatedcounterfeit type coverage. The output of this evaluation will produce Counterfeit Def

14、ect Coverage (CDC), Counterfeit Type Coverage (CTC), Not-Covered Defects (NCDs), and Under-Covered Defects (UCDs). This information will be supplied to the test laboratorys customer in both the test report and the Certificate of Quality Conformance (CoQC). This evaluation method does not address the

15、 effectiveness of detecting tampered type devices.The Test Evaluation Method also describes an Optimized Test Sequence Selection, in which a test sequence is selected that maximizes the CDC utilizing test cost and time as constraints, for any tier level except the Critical Risk Level. The constraint

16、s can be adjusted until the desired CDC is achieved. The output of the Optimized Test Sequence Selection also includes CTC, NCDs, and UCDs.If AS6171/1 is invoked in the contract, the base document, AS6171 General Requirements shall also apply.2. APPLICABLE DOCUMENTSThe following publications form a

17、part of this document to the extent specified herein. The latest issue of SAE publications shall apply. The applicable issue of other publications shall be the issue in effect on the date of the purchase order. In theevent of conflict between the text of this document and references cited herein, th

18、e text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.2.1 SAE PublicationsAvailable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA

19、 and Canada) or +1 724-776-4970 (outside USA), www.sae.org.AS6171 Test Methods Standard: General Requirements, Suspect/Counterfeit, Electrical, Electronic, and Electromechanical Parts3. REQUIREMENTS3.1 Key ElementsKey elements of the assessment framework are summarized below.Test Methods (M) - All t

20、est methods defined in AS6171 are taken into account by the CDC algorithm./ = / 5 / 6 / , where, I is the number of test methods.Counterfeit Defects (D) - The counterfeit related defects and anomalies present in counterfeit parts. By ensuring detection of one or more defects, counterfeit detection c

21、onfidence is increased. Refer to Appendix A for definitions of defects addressed. if needed, test costs and test times should be obtained from an approved test laboratory. In addition, the cost of the parts consumed in testing is not a consideration of the CDC algorithm.SAE INTERNATIONAL AS6171/1 Pa

22、ge 4 of 34Target Confidence (TC) - The level of confidence to be achieved for each defect by performing a set of tests. It is established by the tier level breakpoints (TL) defined in 3.1, Risk Assessment of AS6171 General Requirements.Table 1 - Target confidence valuesTier Level Target Confidence (

23、TC)Critical High 80%-90%Moderate 65%-80%Low 50%-65%Very Low 35%-50%Confidence Level Matrix (CL) - This matrix represents the capability of test methods to detect counterfeit defects. Each entry of the matrix CL represents the confidence level of detecting a defect by a test method.%. = cT g = T 5 5T

24、6 5T 5T 5T 5 6T 6 6T 6T 6T 5 T 6 T T T 5 T 6 T T where, T is the probability of detecting a defect F by a method E , and T defines the upper limits of the matrix. (I represents the total number of test methods and J represents the total number of defects.)T *ECD , /AEQI , .KS = 0.9, 0.7, 0.5If two o

25、r more methods detect a defect F , then the resultant confidence (T ) will be increased and is given by the equation:T = 1 F (1 FT 5 ) (Eq. 1)NOTE: In certain instances, the tests performed may have enough commonality that the resultant confidence may be overestimated since the same defect character

26、istics may be detected by multiple tests resulting in duplication of coverage instead of increased scope of coverage.Additionally, during the selection of tests, the optimization goes in the order of the defects in the table. If the order of defects in the table were changed, it could result in a di

27、fferent sequence of tests due to the different optimization computed by the algorithm.Decision Index (DI) -The probability that a counterfeit type contains one or more known defect types. CTC equals DI if all defects present in a counterfeit type are detectable. DI may approach zero for counterfeit

28、types such as overproduced and cloned due to the rare occurrence of defects. See Table 7 for DI values.Table 2 - Decision indexCounterfeit Type Decision Index (DI)Recycled 0.98Remarked 0.90Overproduced 0.03Out-of-Spec/Defective 0.50Cloned 0.10Forged Documentation 0.70Tampered 0.98Weighting (W) - Ide

29、ntifies the presence of a defect in a counterfeit type. Weighting equals 1 if the defect is present for the counterfeit type and 0 if the defect is not present. Weighting values are shown in Appendix C.SAE INTERNATIONAL AS6171/1 Page 5 of 34Counterfeit Defect Coverage (CDC) - Defined as the ratio of

30、 possible detectable defects to the total number of known counterfeit related defects (see Appendix A for a list of known counterfeit related defects). It gives a cumulative assessment of multiple test methods in terms of their capability of detecting defects and provides an overall confidence after

31、 performing a sequence of tests. The CDC can be expressed as:CDC = T m q q g j c H c r c a r _ j c H c d c a r q X m r _ j H c d c a r q 100%The total confidence of finding a part as counterfeit, CDC, becomes the ratio of the cumulative sum of the resultant confidence of all the defects to the total

32、 number of defects. Thus, it can be expressed by the following equation:% 4 ) ( 4 . ; 5 ) 5 4 4 5 *100%6% =59.15%6% = 0.1 (0.99 0)+ (0.95 1)+ (0.97 1)+ (0.7 0)0 + 1 +1 + 0 100%6% =9.60SAE INTERNATIONAL AS6171/1 Page 10 of 34Step # Name Description11 Report results Report CDC, NCDs, and UCDs.CDC = 58

33、.63%6% =39.38; %6% =59.15; %6% =9.60NCD: Defect #DUCD: None3.3 Optimized Test Sequence SelectionThe objective of the Optimized Test Sequence Selection is to identify a test sequence with user constraints such as desired CDC, test time, and test cost utilizing the test sequence evaluation algorithm.

34、The details of test sequence evaluation are described in 3.2. In the following, we will describe the selection of test methods.Method Selection Algorithm5AHA?P = OAP KB PAOP IAPDKO / ? / PK I=TEIEVA % / 0,1 = 0KP OAHA?PA ,OAHA?PA % : Test cost for test method E6 : Test time for test method E% : User

35、/Requester specified test cost6 : User/Requester specified test time? , ,=J represent subset, for all, and belongs to respectivelySAE INTERNATIONAL AS6171/1 Page 11 of 34Table 10 - Optimized test sequence selectionStep # Name DescriptionMethod Selection1 Select tier levelSelect the desired tier leve

36、l for assessment. This initializes TL with a specific value. For an example, TL will be 0.90 for critical tier applications.2 Establish CL matrixEstablish the CL matrix for each defect in Appendix A based on test coverage from step 2. Confidence levels are established from Appendix B taking the aver

37、age of lower and upper limit. (High = 93%, Medium = 67.5%, Low = 37.5%, Very Low = 15%, Very Very Low = 2.5%, and N/A=0%).3 Determine TC Determine the target confidence (TC) defined in Table 1 based on the TL selected in step 1.4 Method selection Set defect index F = 0 to point the first defect; 5 M

38、ethod selection Set method index E = 06 Method selection Sort methods according to individual CDC contribution for critical tier, and test cost and time for other tier levels.7Method selection Select a method from the top of the sorted method array unless it is selected before; Verify test and time

39、constraint except for critical tier level. Exit if violated.8 Method selection Calculate T 9Method selection If T R 6%Increase defect index (j=j+1) to point the next defect; Go to step 5;Else Select a method from the top of the sorted methodarray; Verify test and time constraint except for critical

40、tier level and undo selection if violated.Increase method index (i=i+1);Go to step 9;10 Method selection All methods selected for custom assessment.Custom Assessment11 Determine resultant testing confidence Calculate T (resultant confidence level) for all defects using the CL matrix from step 3 and

41、Equation 1.12 Determine if a defect is an NCD or UCD If T = 0, then the defect is an NCD.If T 6% , increase defect index to point defect #C.16 Method selection Set method index E = 017 Method selection Sorted method listMethod #2 fractional contribution to the CDC is (0.0+0.0+0.9+0.7)/4=0.4Method #5

42、 fractional contribution to the CDC is (0.0+0.0+0.7+0.0)/4=0.175The remaining methods are not in the list as they cannot detect defect #C.18 Method selection T = 0.9 as there is only one test method is selected for defect #C.19 Method selection As T = 6% = 0.9, increase defect index to point defect

43、#D.20 Method selection Set method index E = 021 Method selection Sorted method listMethod #2 fractional contribution to the CDC is (0.0+0.0+0.9+0.7)/4=0.4The remaining methods are not in the list as they cannot detect defect #C.22 Method selection Method #2 already selected.23 Method selection T = 0

44、.7 85% High 85%EVI-2 Detailed EVI High 85% N/AEVI-3 Testing for Remarking (EVI) N/A N/AEVI-4 Testing for Resurfacing (EVI) N/A N/AEVI-5 Part Dimensions N/A N/AEVI-6 Surface Analysis using SEM (EVI) SEM: entries assume that lead inspection is at the discretion of the test lab N/A N/AX-RAY Fluorescenc

45、e (XRF) AS6171/3XRF-1 Lead Finish Analysis (XRF) N/A N/AXRF-2 Lead Finish Thickness (XRF) N/A N/AXRF-3 Material Composition (XRF) N/A N/ADelid/Decapsulation Physical Analysis (DDPA) AS6171/4DDPA-1 Internal Inspection (DDPA) Combination of elemental analysis, die inspection, and lead frame inspection

46、 N/A N/ADDPA-2 Bond Pull (DDPA) All other internal inspection performed prior to bond pull N/A N/ADDPA-3 Die Attach (DDPA) All other internal inspection performed prior to die attach inspection N/A N/ARadiological Inspection (RI) AS6171/5RI-12D Radiological (RI) - Digital Radiology, DR; or Real Time

47、 Radiography, RTR; or Film Radiology External Visual inspection (per Test Method 1) N/A N/ARI-2 3D Computed Tomography, CT(RI) IncrementalExternal Visual inspection (per Test Method 1); 2D Radiological (RI) - Digital Radiology, DR; or Real Time Radiography, RTR; or Film Radiology N/A N/ARI-3 3D Comp

48、uted Tomography, CT(RI) Independent External Visual inspection (per Test Method 1) N/A N/AAcoustic Microscopy (AM) AS6171/6AM-1 PEMS - External Only (AM) N/A N/AAM-2 PEMS - External, Internal Key AC/Switching parameters and Key Functional at ambient temperature N/A N/AET-A-5 Burn-In with Electrical Limits and Delta L