1、_SAE Technical Standards Board Rules provide that: “This report is published by SAE to advance the state of technical and engineering sciences. The use of this report is entirely voluntary, and its applicability and suitability for any particular use, including any patent infringement arising theref
2、rom, is the sole responsibility of the user.”SAE reviews each technical report at least every five years at which time it may be revised, reaffirmed, stabilized, or cancelled. SAE invites your written comments and suggestions.Copyright 2016 SAE InternationalAll rights reserved. No part of this publi
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/AS6171/9AEROSPACESTANDARDAS6171/9Issued 2016-10Techniques for Suspect/Counterfeit EEE Parts Detection by Fo
5、urier Transform Infrared Spectroscopy (FTIR) Test MethodsRATIONALEThis document was created to provide guidance for those unfamiliar with Fourier Transform Infrared (FTIR) spectroscopy towards its application of counterfeit detection of electronic components. Additionally, this document is intended
6、to provideguidelines for the application of FTIR spectroscopy and to define the compliance requirements for laboratories using this technique.INTRODUCTIONFourier transform infrared spectroscopy is used to obtain infrared spectra of materials which are akin to “fingerprints” allowing for materials id
7、entification and verification. In the context of counterfeit detection this method could allow for the determination that the proper class of encapsulation, polymer, lettering, coating, etc., is applied to components under investigation. This will be particularly useful when known authentic parts ar
8、e available for comparison purposes. This method could also be applied to detect foreign materials such as blasting beads used to alter parts. Solvent extractions of Device Under Test (DUT) could also indicate if parts had been exposed to cleaners or other materials used during part alteration.FTIR
9、spectroscopy is more universal than many analytical techniques and allows for the analysis of a variety of compounds including both organic and inorganic materials. Single-bounce Attenuated Total Reflectance (ATR) crystals allow for analysis of samples of about 200 microns diameter and larger, while
10、 the use of FTIR microscopy extends this down to the diffraction limit of about 10 microns diameter. Thin films can also be analyzed using techniques such as grazing angle reflectance; however, this approach would be limited to samples that are amenable to such investigations. In theory all infrared
11、 active materials produce unique spectra leading to the fingerprint analogy. In this regard databases ofa wide variety of materials are available for matching purposes. Also, reference spectra of known authentic parts can be compared to DUT spectra. Pass/Fail criteria can be established using a vari
12、ety of techniques.Although FTIR microscopy can extend to a diffraction limit of about 10 microns, in most cases, as will be outlined herein, FTIR spectroscopy is a bulk analysis technique. That is, the spectrum that is created is a weighted average of all materials present. As a result, analysis of
13、mixtures can be complicated and detection of trace components difficult to impossible. Also, in many cases, for example with regards to polymer characterization, identification of chemical class is generally straight forward while identification of slight variants within a class is much more tedious
14、, if possible at all.While most materials are accessible using FTIR spectroscopy, some are not. An example is carbon black which is a common additive that is essentially IR opaque. This can hinder the analysis of carbon filled materials. Other materials including many inorganic salts and metals are
15、not detectable by infrared spectroscopy.SAE INTERNATIONAL AS6171/9 Page 2 of 19TABLE OF CONTENTS1. SCOPE 42. REFERENCES 42.1 Applicable Documents 42.1.1 SAE Publications. 42.1.2 ASTM Publications 42.1.3 Other Publications. 42.2 Terms and Definitions . 52.3 Acronyms 53. EQUIPMENT AND OTHER SUPPLIES 5
16、4. TEST SAMPLE . 54.1 Sample Limitations 55. MATERIALS HANDLING, STORAGE, AND SAMPLE PREPARATION. . 56. DESCRIPTION OF METHODOLOGY 66.1 The Infrared Spectrometer 66.2 The Background 76.3 Sampling Techniques 76.3.1 Transmission Spectroscopy 86.3.2 Reflectance Spectroscopy 86.3.3 Attenuated Total Refl
17、ectance (ATR) Spectroscopy 96.4 Acquisition of Spectra . 96.4.1 Nondestructive Analysis 106.4.2 Destructive Analysis 107. CONTROLS AND CALIBRATION 108. ANALYSIS AND INTERPRETATION OF DATA. 108.1 Material Analysis - Comparison of DUT Spectra to Known Authentic Parts. 118.2 Material Analysis - Compari
18、son of DUT Spectra to Spectra Based on Part Specifications . 128.3 Contamination Analysis. 139. REPORTING OF RESULTS . 1410. QUALIFICATION AND CERTIFICATION . 1510.1 Personnel Qualification . 1510.1.1 Level 3 - Advanced Interpretation (Typically a Chemist) 1510.1.2 Level 2 - Basic Interpretation (Ty
19、pically a Technician) . 1510.1.3 Level 1 - Operation (Typically an Operator) 1510.2 Safety 1611. NOTES 1611.1 Revision Indicator 16APPENDIX A EXAMPLES OF APPLICATION OF FTIR SPECTROSCOPY TO COUNTERFEIT DETECTION. 17SAE INTERNATIONAL AS6171/9 Page 3 of 19FIGURE 1 TYPICAL FTIR SPECTROMETER LAYOUT 6FIG
20、URE 2 INTERFEROMETER. 7FIGURE 3 EXAMPLE OF TRANSMISSION THROUGH SAMPLE 8FIGURE 4 REFLECTANCE 8FIGURE 5 GRAZING ANGLE REFLECTANCE . 8FIGURE 6 ATTENUATED TOTAL REFLECTANCE 9FIGURE 7 EXAMPLES OF SIMILAR MATERIALS PRODUCING NEARLY IDENTICAL SPECTRA . 12TABLE 1 REQUIRED TEST REPORT INFORMATION. 14SAE INT
21、ERNATIONAL AS6171/9 Page 4 of 191. SCOPEThis document defines capabilities and limitations of FTIR spectroscopy as it pertains to counterfeit electronic component detection and suggests possible applications to these ends. Additionally, this document outlines requirements associated with the applica
22、tion of FTIR spectroscopy including: operator training, sample preparation, various sampling techniques, data interpretation, computerized spectral matching including pass/fail criteria, equipment maintenance, and reporting of data. The discussion is primarily aimed at analyses performed in the mid-
23、infrared (IR) from 400 to 4000 wavenumbers; however, many of the concepts are applicable to the near and far IR.If AS6171/9 is invoked in the contract, the base document, AS6171 General Requirements shall also apply.2. REFERENCES2.1 Applicable DocumentsThe following publications form a part of this
24、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, the text of thi
25、s document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained.2.1.1 SAE PublicationsAvailable from SAE International, 400 Commonwealth Drive, Warrendale, PA 15096-0001, Tel: 877-606-7323 (inside USA and Canada
26、) or +1 724-776-4970 (outside USA), www.sae.org.AS6171 Test Methods Standard: General Requirements, Suspect/Counterfeit Electrical, Electronic, and Electromechanical Parts2.1.2 ASTM PublicationsAvailable from ASTM International, 100 Barr Harbor Drive, P.O. Box C700, West Conshohocken, PA 19428-2959,
27、 Tel: 610-832-9585, www.astm.org.ASTM E334 Standard Practice for General Techniques of Infrared MicroanalysisASTM E573 Standard Practices for Internal Reflection SpectroscopyASTM E1252 Standard Practice for General Techniques for Obtaining Infrared Spectra for Qualitative AnalysisASTM E1421 Standard
28、 Practice for Describing and Measuring Performance of Fourier Transform Mid-Infrared (FT-MIR) Spectrometers: Level Zero and Level One Tests2.1.3 Other PublicationsIPC-TM-650 2.3.39 Surface Organic Contamination Identification Test (Infrared Analytical Method)JESD-625 Requirements for Handling Electr
29、ostatic Discharge Sensitive (ESD) DevicesANSI/ESD S20.20 Protection of Electrical and Electronic Parts, Assemblies and EquipmentIDEA-STD-1010 Acceptability of Electronic Components Distributed in the Open MarketSAE INTERNATIONAL AS6171/9 Page 5 of 192.2 Terms and DefinitionsAll terms that require de
30、finition are defined in the paragraph in which they are first used.2.3 AcronymsSee 2.3 of AS6171 General Requirements.3. EQUIPMENT AND OTHER SUPPLIESThis method shall require an infrared spectrometer. There is a wide variety of instruments available ranging from simple bench top designs to high reso
31、lution systems. For the purposes of counterfeit detection the analyses will be mostly qualitative in nature and will not require advanced experimental techniques. At a minimum the system shall be able to record spectra at 4 cm-1 resolution and have data handling software including database building
32、and database matching capabilities. The system should have multiple analyses options including bench top and microscope transmission, reflectance, and ATR methods.Standard supplies that may be necessary include ATR crystals for ATR equipped systems, salt windows, purge gasses when necessary, sample
33、holders, knives and probes, and sampling discs (transmission cards, silicon carbide discs, etc.). 4. TEST SAMPLEThis method can be used for a wide variety of sample types and, as such, the best practices for the analysis method chosen (i.e., destructive versus nondestructive, surface ATR versus comp
34、ression transmission cell, etc.) shall be followed. The previous test history of the individual part shall be provided prior to testing. To prevent interference from alterations that may have occurred during prior handling, if a previously untested part is available, it shall be used for testing. A
35、Level 2 or 3 Person required by the method shall determine if this history can adversely impact the test results. If it is deemed that the test history will adversely impact the test results, the test shall not be performed on this part and a previously untested part or a part with a different test
36、history shall be obtained.4.1 Sample LimitationsNot all materials are accessible using FTIR spectroscopy. If materials have no dipole moment at any of their chemical bonds they are generally poor candidates. Examples include pure elements such as nitrogen, silicon, or graphite. Another example of th
37、is is unoxidized metals and alloys. Carbon containing materials (graphite or carbon black) such as filled rubbers are particularly problematic as the carbon filler tends to make the sample infrared opaque; this can possibly be overcome with use of ATR. The wavelengths of infrared energy force a lowe
38、r limit of about a 10 micron sample size. As sample sizes approach this limit spectral quality generally suffers. The lab shall determine the sample size limitations and shall determine the minimum sample size below which a microscope is required. For such applications a microscope accessory shall b
39、e used.5. MATERIALS HANDLING, STORAGE, AND SAMPLE PREPARATION.ESD sensitive items shall be handled from receipt to delivery in accordance with ANSI/ESD S20.20 or J-STD-625.Moisture sensitive items shall be handled from receipt through delivery in accordance with the requirements of IPC/JEDEC J-STD-2
40、0 and J-STD-033. Refer to the requirements in 3.9.5 of AS6171 - General Requirements Document.NOTE: IDEA-STD-1010 Sections 7.1 and 7.3 provide workstation guidelines.All materials, including samples and sample preparation and analysis devices, shall be handled according to best lab practices, as app
41、licable (i.e., care taken not to contaminate samples, clean work areas and equipment, etc.). Samples shall be prepared according to analysis techniques chosen as most appropriate, for example non-destructive versusdestructive, ATR versus compression transmission cell, solvent extraction versus direc
42、t reflectance.SAE INTERNATIONAL AS6171/9 Page 6 of 196. DESCRIPTION OF METHODOLOGYWhen most materials are exposed to infrared radiation, they absorb specific wavelengths of the incident energy to varyingdegrees. This induces vibrations between the atoms or molecules which occur at discrete energies
43、as a function of the chemical bonding present in the sample. The result, the infrared spectrum, is a plot of the relative amounts of energy absorbed at various wavelengths by a sample. This is usually plotted, by convention, as wavenumber (which is the number of waves per unit distance and has the u
44、nits of reciprocal centimeters, 1/O), versus either the percentage of the incident beam transmitted through the sample (transmittance, %T), or absorbed by the sample (absorbance, log10 (100/%T). Because the absorptions are characteristic of chemical bonding, an experienced operator can deduce the ty
45、pes of bonds present in the sample. As such, the interpretation of the spectrum is often referred to as functional group analysis. 6.1 The Infrared SpectrometerAs opposed to traditional scanning instruments, FTIR spectrometers analyze all wavelengths of incident energy simultaneously. As illustrated
46、 in Figures 1 and 2, half the infrared beam is passed to a fixed mirror while the other half is sent to a moving mirror. These are then recombined and passed through the sample and onto the detector. Because the two beams travel different distances as a function of time related to the rate of the mo
47、ving mirror, the recombined beams are the sum of all the destructive and constructive interferences of the individual waves incident on the sample. In Figure 2, the moving mirror and fixed mirror are positioned to give an equal path length, and all the interference is constructive.The product of the
48、 interference between the two beams is called an “interferogram,” which is the signal that is recorded and processed using a Fourier transform to produce the infrared spectrum. A reference laser signal is also simultaneously analyzed as an internal standard for wavelength calibration.Figure 1 - Typi
49、cal FTIR spectrometer layout(Figure courtesy of Thermo Fisher Scientific)SAE INTERNATIONAL AS6171/9 Page 7 of 19Figure 2 - InterferometerThe beam is split to fixed and moving mirror. (Figure courtesy of Thermo Fisher Scientific)6.2 The BackgroundAs is the case with many spectroscopic methods, background spectra shall be collected for reference to the sample spectra. These are needed to correct for contributions from the atmosphere (car
