1、 IEC 60749-4 Edition 2.0 2017-03 INTERNATIONAL STANDARD Semiconductor devices Mechanical and climatic test methods Part 4: Damp heat, steady state, highly accelerated stress test (HAST) IEC 60749-4:2017-03(en) THIS PUBLICATION IS COPYRIGHT PROTECTED Copyright 2017 IEC, Geneva, Switzerland All rights
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9、C Glossary - std.iec.ch/glossary 65 000 electrotechnical terminology entries in English and French extracted from the Terms and Definitions clause of IEC publications issued since 2002. Some entries have been collected from earlier publications of IEC TC 37, 77, 86 and CISPR. IEC Customer Service Ce
10、ntre - webstore.iec.ch/csc If you wish to give us your feedback on this publication or need further assistance, please contact the Customer Service Centre: csciec.ch. IEC 60749-4 Edition 2.0 2017-03 INTERNATIONAL STANDARD Semiconductor devices Mechanical and climatic test methods Part 4: Damp heat,
11、steady state, highly accelerated stress test (HAST) INTERNATIONAL ELECTROTECHNICAL COMMISSION ICS 31.080.01 ISBN 978-2-8322-4002-1 Registered trademark of the International Electrotechnical Commission Warning! Make sure that you obtained this publication from an authorized distributor. 2 IEC 60749-4
12、:2017 IEC 2017 CONTENTS FOREWORD . 3 1 Scope 5 2 Normative references 5 3 Terms and definitions 5 4 HAST test General remarks 5 5 Test apparatus 6 5.1 Test apparatus requirements 6 5.2 Controlled conditions 6 5.3 Temperature profile 6 5.4 Devices under stress 6 5.5 Minimize release of contamination
13、6 5.6 Ionic contamination . 6 5.7 De-ionized water . 6 6 Test conditions 6 6.1 Test conditions requirements 6 6.2 Biasing guidelines . 7 6.3 Choosing and reporting . 8 7 Procedure 8 7.1 Test device mounting 8 7.2 Ramp-up . 8 7.3 Ramp-down 8 7.4 Test clock . 8 7.5 Bias 8 7.6 Readout 9 7.7 Handling .
14、9 7.8 Calibration records 9 8 Failure criteria . 9 9 Safety 9 10 Summary . 9 Table 1 Temperature, relative humidity and duration requirements 7 Table 2 Bias and reporting requirements 8 IEC 60749-4:2017 IEC 2017 3 INTERNATIONAL ELECTROTECHNICAL COMMISSION _ SEMICONDUCTOR DEVICES MECHANICAL AND CLIMA
15、TIC TEST METHODS Part 4: Damp heat, steady state, highly accelerated stress test (HAST) 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
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25、le 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 60749-4 has
26、been prepared by IEC technical committee 47: Semiconductor devices. This second edition cancels and replaces the first edition published in 2002. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: a)
27、clarification of requirements for temperature, relative humidity and duration detailed in Table 1; b) recommendations that current limiting resistor(s) be placed in the test set-up to prevent test board or DUT damage; c) allowance of additional time-to-test delay or return-to-stress delay. 4 IEC 607
28、49-4:2017 IEC 2017 The text of this standard is based on the following documents: FDIS Report on voting 47/2346/FDIS 47/2371/RVD 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 dr
29、afted in accordance with the ISO/IEC Directives, Part 2. A list of all parts in the IEC 60749 series, published under the general title Semiconductor devices Mechanical and climatic test methods, can be found on the IEC website. The committee has decided that the contents of this document will remai
30、n 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
31、 a later date. IEC 60749-4:2017 IEC 2017 5 SEMICONDUCTOR DEVICES MECHANICAL AND CLIMATIC TEST METHODS Part 4: Damp heat, steady state, highly accelerated stress test (HAST) 1 Scope This part of IEC 60749 provides a highly accelerated temperature and humidity stress test (HAST) for the purpose of eva
32、luating the reliability of non-hermetic packaged semiconductor devices in humid environments. 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 c
33、ited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. IEC 60749-5, Semiconductor devices Mechanical and climatic test methods Part 5: Steady state temperature humidity bias life test 3 Terms and definitions No terms and definitions ar
34、e listed in this document. 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 HAST test General remarks The HAST test employ
35、s severe conditions of temperature, humidity and bias which accelerate the penetration of moisture through the external protective material (encapsulant or seal) or along the interface between the external protective material and the metallic conductors which pass through it. The stress usually acti
36、vates the same failure mechanisms as the “85/85” steady-state temperature humidity bias life test, IEC 60749-5. As such the test method may be selected from IEC 60749-5 or from this test method. When both test methods are performed, test results of the 85 C/85 % RH steady-state temperature humidity
37、bias life test, IEC 60749-5, take priority over HAST. This test method shall be considered destructive. 6 IEC 60749-4:2017 IEC 2017 5 Test apparatus 5.1 Test apparatus requirements The test requires a pressure chamber capable of maintaining a specified temperature and relative humidity continuously,
38、 while providing electrical connections to the devices under test in a specified biasing configuration. 5.2 Controlled conditions The chamber shall be capable of providing controlled conditions of pressure, temperature and relative humidity during ramp-up to and ramp-down from the specified test con
39、ditions. 5.3 Temperature profile A permanent record of the temperature profile for each test cycle is recommended so that the validity of the stress can be verified. 5.4 Devices under stress Devices under stress shall be mounted in such a way that temperature gradients are minimized. Devices under s
40、tress shall be no closer than 3 cm from internal chamber surfaces, and shall not be subjected to direct radiant heat from heaters. Boards on which devices are mounted should be oriented to minimize interference with vapour circulation. 5.5 Minimize release of contamination Care shall be exercised in
41、 the choice of board and socket materials, to minimize release of contamination and to minimize degradation due to corrosion and other mechanisms. 5.6 Ionic contamination Ionic contamination of the test apparatus (card cage, test boards, sockets, wiring storage containers, etc.) shall be controlled
42、to avoid test artefacts. 5.7 De-ionized water De-ionized water with a minimum resistivity of 1 10 4m at room temperature shall be used. 6 Test conditions 6.1 Test conditions requirements Test conditions consist of a temperature, relative humidity, and duration in conjunction with an electrical bias
43、configuration specific to the device. Unless otherwise required by the detailed specification the test conditions shall be selected from Table 1. IEC 60749-4:2017 IEC 2017 7 Table 1 Temperature, relative humidity and duration requirements Temperature a(dry bulb) Relative humidity aTemperature b (wet
44、 bulb) Vapour pressure bDuration cC % C kPa h 130 2 85 5 124,7 230 96 ( 0 2 + ) 110 2 85 5 105,2 122 264 ( 0 2 + ) For parts that reach absorption equilibrium in 24 h or less, the HAST test is equivalent to at least 1 000 h at 85 C/85 % RH. For parts that require more than 24 h to reach equilibrium
45、at the specified HAST condition, the time should be extended to allow parts to reach equilibrium. Caution: For plastic-encapsulated micro-circuits, it is known that moisture reduces the effective glass transition temperature of the moulding compound. Stress temperatures above the effective glass tra
46、nsition temperature can lead to failure mechanisms unrelated to standard 85 C/85 % RH stress. aTolerances apply to the entire useable test area. bFor information only. cThe test conditions are to be applied continuously except during any interim readouts when devices should be returned to stress wit
47、hin the time specified in 7.6. The 96 h and 264 h test durations were selected to be at least equivalent 1 000 h of 85 C/85 % RH stress using a worst case activation energy of E a= 0,65 eV. 6.2 Biasing guidelines Apply bias according to the following guidelines: a) Minimize power dissipation. b) Alt
48、ernate pin bias as much as possible. c) Distribute potential differences across chip metallization as much as possible. d) Maximize voltage within operating range. NOTE The priority of the above guidelines depends on mechanism and specific device characteristics. e) Either of two kinds of bias can b
49、e used to satisfy these guidelines, whichever is more severe: 1) Continuous bias The DC bias shall be applied continuously. Continuous bias is more severe than cycled bias when the die temperature is 10 C higher than the chamber ambient temperature or, if the die temperature is not known when the heat dissipation of the DUT is less than 200 mW. If the heat dissipation of the DUT exceeds 200 mW, then the die temperature should be calculated. If the die temperature excee
