1、BSI Standards PublicationSemiconductor devices Micro-electromechanical devicesPart 21: Test method for Poissons ratio of thin film MEMS materialsBS EN 62047-21:2014National forewordThis British Standard is the UK implementation of EN 62047-21:2014. It isidentical to IEC 62047-21:2014.The UK particip
2、ation in its preparation was entrusted to TechnicalCommittee EPL/47, Semiconductors.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisions ofa contract. Users are responsible for its c
3、orrect application. The British Standards Institution 2014.Published by BSI Standards Limited 2014ISBN 978 0 580 77554 3ICS 31.080.99Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Stra
4、tegy Committee on 31 October 2014.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS EN 62047-21:2014EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN 62047-21 September 2014 ICS 31.080.99 English Version Semiconductor devices - Micro-electromechanical devices - Part
5、21: Test method for Poissons ratio of thin film MEMSmaterials (IEC 62047-21:2014) Dispositifs semiconducteurs - Dispositifsmicrolectromcaniques - Partie 21: Mthode dessai relative au coefficient dePoisson des matriaux MEMS en couche mince (CEI 62047-21:2014) Halbleiterbauelemente - Bauelemente derMi
6、krosystemtechnik - Teil 21: Prfverfahren zur Querkontraktionszahl vonDnnschichtwerkstoffen der Mikrosystemtechnik (IEC 62047-21:2014) This European Standard was approved by CENELEC on 2014-07-24. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the condit
7、ions 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 exis
8、ts 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 natio
9、nal 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, Port
10、ugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. European Committee for Electrotechnical Standardization Comit Europen de Normalisation ElectrotechniqueEuropisches Komitee fr Elektrotechnische Normung CEN-CENELEC Management Centre: Avenue Marnix 17, B-100
11、0 Brussels 2014 CENELEC All rights of exploitation in any form and by any means reserved worldwide for CENELEC Members. Ref. No. EN 62047-21:2014 E EN 62047-21:2014 - 2 - Foreword The text of document 47F/185/FDIS, future edition 1 of IEC 62047-21, prepared by SC 47F “Microelectromechanical systems”
12、 of IEC/TC 47 “Semiconductor devices“ was submitted to the IEC-CENELEC parallel vote and approved by CENELEC as EN 62047-21:2014. 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 endorsemen
13、t (dop) 2015-04-24 latest date by which the national standards conflicting with the document have to be withdrawn (dow) 2017-07-24 Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CENELEC and/or CEN shall not be held responsible fo
14、r identifying any or all such patent rights. Endorsement notice The text of the International Standard IEC 62047-21:2014 was approved by CENELEC as a European Standard without any modification. BS EN 62047-21:2014- 3 - EN 62047-21:2014 Annex ZA (normative) Normative references to international publi
15、cations 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 undated references, the latest edition of the referenc
16、ed document (including any amendments) applies. NOTE 1 When 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: w
17、ww.cenelec.eu Publication Year Title EN/HD Year IEC 62047-8 2011 Semiconductor devices - Micro-electromechanical devices - Part 8: Strip bending test method for tensile property measurement of thin films EN 62047-8 2011 ASTM E132-04 2010 Standard test method for Poissons ratio at room temperature -
18、- BS EN 62047-21:2014 2 IEC 62047-21:2014 IEC 2014 CONTENTS 1 Scope 5 2 Normative references 5 3 Terms, definitions, symbols and designations 5 3.1 Terms and definitions 5 3.2 Symbols and designations 5 4 Test piece . 6 4.1 General . 6 4.2 Shape of the test piece . 7 4.3 Measurement of dimensions .
19、7 5 Testing method and test apparatus 7 5.1 Test principle 7 5.2 Test machine 7 5.3 Test procedure 7 5.3.1 Test procedure for type 1 test piece . 7 5.3.2 Test procedure for type 2 test piece . 8 5.4 Test environment 8 6 Test report . 8 Annex A (informative) Measurement example of Poissons ratio usin
20、g type 1 test piece . 9 A.1 Fabrication of the test piece 9 A.2 Dimensions of the test piece . 9 A.3 Test procedures 9 A.4 Test results . 10 Annex B (informative) Analysis of test results obtained from a type 2 test piece . 11 B.1 General . 11 B.2 Evaluation of stress and strain in circular and rect
21、angular membranes . 11 B.3 Evaluation of Poissons ratio . 12 Bibliography 13 Figure 1 Two types of test pieces for the measurement of Poissons ratio 6 Figure A.1 Optical images of markers for strain measurement by DIC 9 Figure A.2 Graphs of load and strain in the longitudinal and transverse directio
22、ns . 10 Table 1 Symbols and designations of a test piece 6 BS EN 62047-21:2014IEC 62047-21:2014 IEC 2014 5 SEMICONDUCTOR DEVICES MICRO-ELECTROMECHANICAL DEVICES Part 21: Test method for Poissons ratio of thin film MEMS materials 1 Scope This part of IEC 62047 specifies the determination of Poissons
23、ratio from the test results obtained by the application of uniaxial and biaxial loads to thin-film micro-electromechanical systems (MEMS) materials with lengths and widths less than 10 mm and thicknesses less than 10 m. 2 Normative references The following documents, in whole or in part, are normati
24、vely referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 62047-8:2011, Semiconductor devices Micro-electromechanical
25、devices Part 8: Strip bending test method for tensile property measurement of thin films ASTM E 132-04:2010, Standard test method for Poissons ratio at room temperature 3 Terms, definitions, symbols and designations 3.1 Terms and definitions For the purposes of this document, the following terms and
26、 definitions apply. 3.1.1 Poissons ratio ratio of transverse strain multiplied by (-1) to the corresponding longitudinal strain resulting from uniformly distributed longitudinal stress below the proportional limit of the material, expressed as -t/l, where tis transverse strain, and lis longitudinal
27、strain 3.2 Symbols and designations Symbols and designations of two types of test pieces are presented in Figure 1 and Table 1, respectively. BS EN 62047-21:2014 6 IEC 62047-21:2014 IEC 2014 a) Type 1 test piece for uniaxial tensile machine b) Type 2 test piece for membrane bulging machine Figure 1
28、Two types of test pieces for the measurement of Poissons ratio Table 1 Symbols and designations of a test piece Symbol Unit Designation l1m Gauge length for longitudinal strain measurement l2m Gauge length for transverse strain measurement b m Width of test piece L m Overall length R m Filet radius
29、of test piece m1m Length of a rectangular membrane m2m Width of a rectangular membrane m3m Diameter of a circular membrane h m Thickness of membrane 4 Test piece 4.1 General The test piece should be prepared using a fabrication process similar to the actual fabrication of devices. It should have dim
30、ensions on the same order as those of the mother device to minimise the effect of size-dependent properties. An example of the fabrication process can be found in IEC 62047-8. The gradient of the internal stress in the direction of thickness should be minimised using an annealing process, but the an
31、nealing process should be avoided when Youngs modulus and Poissons ratio of the sample can be affected. Two types of test pieces are utilised in this standard and are described in the following 4.2 and 4.3. IEC 1837/14 m2m3m2hIEC 1836/14 R l1l2bL BS EN 62047-21:2014IEC 62047-21:2014 IEC 2014 7 4.2 S
32、hape of the test piece Two types of test pieces are specified in this standard. Type 1 has a shape similar to a tensile specimen (Figure 1a), whereas type 2 has two membranes (Figure 1b). In type 1, two pairs of gauge markers shall be fashioned to define both longitudinal and transverse strains. By
33、measuring the longitudinal and transverse strains, the Poissons ratio is calculated by the ratio of -t/lspecified in 3.1. When a wrinkle forms in the test piece during the tensile test due to compressive strain in the transverse direction, undesirable out-of-plane deformation can lead to an error in
34、 the optical measurement, obscuring the optical measurement of transverse strain. In this case, a type 2 test piece should be used instead of a type 1 test piece. In type 2, circular and rectangular membranes are included in the test piece. The maximum deflections of the two membranes are measured s
35、imultaneously under a given pressure. The pressure applied to the two membranes should be identical. The out-of-plane deflection due to the applied pressure should be measured using an optical technique or atomic force microscopy (AFM) to minimise the mechanical disturbance of the test piece. For th
36、e rectangular membrane, the ratio between the length and width (m1/ m2) should be larger than 4. 4.3 Measurement of dimensions To analyse the test results, an accurate measurement of the test-piece dimensions is required because the dimensions are used to extract the mechanical properties of test ma
37、terials. In the type 1 test piece, the longitudinal and transverse gauge lengths (l1, l2), width (b), and thickness (h) shall be measured with an error of less than 5 %. In the type 2 test piece, the width (m2) of the rectangular membrane, the diameter (m3) of the circular membrane, and the film thi
38、ckness (h) shall be measured with an error of less than 5 %. 5 Testing method and test apparatus 5.1 Test principle With a type 1 test piece, the test is performed by applying a tensile load to the test piece. The longitudinal and transverse strains induced by the tensile load should be uniform over
39、 a pre-defined gauge section in the elastic region of the test piece. The longitudinal and transverse strains should be measured simultaneously, and the time delay between them should be less than 1/100 of the data-sampling period. When there is curling in the test piece, it is difficult to measure
40、the transverse strain. In this case, Poissons ratio should be measured using a type 2 test piece. With a type 2 test piece, the test is performed by applying air pressure to the test piece. The circular and rectangular membranes should experience the same applied pressure. The deflections of both me
41、mbranes should be measured simultaneously, and the time delay between them should be less than 1/100 of the data-sampling period. 5.2 Test machine The test machine for a type 1 test piece is similar to a conventional tensile test machine, except that it is capable of measuring transverse strain. Due
42、 to the thinness of the test piece, the longitudinal and transverse strains shall be measured using optical techniques such as laser interferometry or digital image correlation (DIC). The test machine for a type 2 test piece consists of an air compressor, air regulator, pressure sensor, and displace
43、ment sensor for measuring out-of-plane deflections. 5.3 Test procedure 5.3.1 Test procedure for type 1 test piece a) Fix the test piece using the tensile grip. The longitudinal direction of the test piece shall be aligned with the actuating direction of the test apparatus, and the deviation angle sh
44、all be less than 1 degree, as specified in 4.4 of IEC 62047-8:2011. b) Verify the strain measurement unit for longitudinal and transverse strains. These strain signals shall be measured simultaneously with the load signal. BS EN 62047-21:2014 8 IEC 62047-21:2014 IEC 2014 c) Apply a tensile load to t
45、he test piece at a constant strain rate (or grip-to-grip displacement rate). The strain rate shall range from 0,01 min-1to 10 min-1depending on the material system of the test piece and the actual usage condition of the customer. d) Unload the test apparatus when the load sufficiently exceeds the pr
46、oportional limit. e) Draw a graph of the longitudinal and transverse strains with respect to load as described in ASTM E 132-04 and determine Poissons ratio. 5.3.2 Test procedure for type 2 test piece a) Fix the test piece to the grip of the test apparatus. The grip should have inlet and outlet port
47、s for air pressure and a connection port that allows air pressure to be applied to the test piece. The air pressure line in the grip should be designed to deliver identical pressure to both membranes in the test piece. b) Apply air pressure to both the circular and rectangular membranes in the test
48、piece and measure the central deflections of both membranes and the applied pressure. c) Unload the test apparatus when the pressure exceeds the proportional limit of the test piece or if the membranes rupture. d) Analyse the test results and determine Poissons ratio according to Annex B. 5.4 Test e
49、nvironment Because the mechanical properties are temperature and humidity sensitive, fluctuations in temperature during the test shall be controlled to be less than 2 C, and the change in relative humidity (RH) in the testing laboratory shall be controlled to be less than 5 % RH. 6 Test report The test report shall contain the following information. a) Reference to this international standard; b) Test piece identification; c) Test piece material; using a single c
