1、BRITISH STANDARD BS EN 60749-8:2003 Semiconductor devices Mechanical and climatic test methods Part 8: Sealing The European Standard EN 60749-8:2003 has the status of a British Standard ICS 31.080.01 BS EN 60749-8:2003 This British Standard was published under the authority of the Standards Policy a
2、nd S t r a t e g y C o m m i t t e e o n 3 July 2003 BSI 3 July 2003 ISBN 0 580 42201 1 National foreword This British Standard is the official English language version of EN 60749-8:2003. It is identical with IEC 60749-8:2002. It partially supersedes BS EN 60749:1999 which will be withdrawn on 2005
3、-10-01. The UK participation in its preparation was entrusted to Technical Committee EPL/47, Semiconductors, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement inte
4、rnational or European publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not pur
5、port to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committ
6、ee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 16,
7、 an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD EN 60749-8 NORME EUROPENNE EUROPISCHE NORM June 2003 CENELEC European Committee for Elect
8、rotechnical Standardization Comit Europen de Normalisation Electrotechnique Europisches Komitee fr Elektrotechnische Normung Central Secretariat: rue de Stassart 35, B - 1050 Brussels 2003 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members. Ref.
9、No. EN 60749-8:2003 E ICS 31.080.01 English version Semiconductor devices - Mechanical and climatic test methods Part 8: Sealing (IEC 60749-8:2002 + corrigendum 2003) Dispositifs semiconducteurs - Mthodes dessais mcaniques et climatiques Partie 8: Etanchit (CEI 60749-8:2002 + corrigendum 2003) Halbl
10、eiterbauelemente - Mechanische und klimatische Prfverfahren Teil 8: Dichtheit (IEC 60749-8:2002 + Corrigendum 2003) This European Standard was approved by CENELEC on 2002-09-24. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving th
11、is 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 Central Secretariat or to any CENELEC member. This European Standard exists in three official versio
12、ns (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 Central Secretariat has the same status as the official versions. CENELEC members are the national electrotechnical committees of A
13、ustria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Luxembourg, Malta, Netherlands, Norway, Portugal, Slovakia, Spain, Sweden, Switzerland and United Kingdom. Foreword The text of the International Standard IEC 60749-8:2002 was approved by CE
14、NELEC as EN 60749-8 on 2002-09-24. The text of this International Standard was reproduced from IEC 60749:1996, chapter 3, clause 5 without change. Therefore, it has not been submitted to vote a second time and is still based on document 47/1574/FDIS. The following dates were fixed: latest date by wh
15、ich the EN has to be implemented at national level by publication of an identical national standard or by endorsement (dop) 2004-01-01 latest date by which the national standards conflicting with the EN have to be withdrawn (dow) 2005-10-01 Each test method governed by this standard and which is par
16、t of the series is a stand-alone document, numbered EN 60749-2, EN 60749-3, etc. The numbering of these test methods is sequential, and there is no relationship between the number and the test method (i.e. no grouping of test methods). The list of these tests will be available in the CENELEC interne
17、t site and in the catalogue. Updating of any of the individual test methods is independent of any other part. Annexes designated “normative“ are part of the body of the standard. In this standard, annex ZA is normative. Annex ZA has been added by CENELEC. _ Endorsement notice The text of the Interna
18、tional Standard IEC 60749-8:2002 and its corrigendum April 2003 was approved by CENELEC as a European Standard without any modification. _ Page2 EN607498:2003CONTENTS INTRODUCTION.4 1 Scope and object5 2 Normative references.5 3 General terms5 3.1 Units of pressure.5 3.2 Standard leak rate.5 3.3 Mea
19、sured leak rate5 3.4 Equivalent standard leak rate 6 4 Bomb pressure test 6 5 Fine leak detection: radioactive krypton method .6 5.1 Object.6 5.2 General description.6 5.3 Personnel precautions.8 5.4 Procedure.8 5.5 Specified conditions 9 5.6 Gross leak detection9 6 Fine leak detection: tracer gas (
20、helium) method with mass spectrometer9 6.1 General.9 6.2 Method 1: specimens not filled with helium during manufacture Fixed method9 6.3 Method 2: specimens not filled with helium during manufacture Flexible method10 6.4 Method 3: specimens filled with helium during manufacture.11 6.5 Gross leak det
21、ection11 7 Gross leaks, perfluorocarbon vapour method using electronic detection apparatus.11 7.1 Object.11 7.2 General description.11 7.3 Test apparatus11 7.4 Test method12 7.5 Reject criterion12 8 Gross leak Perfluorocarbon bubble detection method .13 9 Test condition E, weight-gain gross-leak det
22、ection .13 9.1 Object.13 9.2 Equipment.13 9.3 Procedure.14 9.4 Failure criteria.14 10 Penetrant dye gross leak detection.15 11 Gross leak re-test.15 Annex ZA (normative) Normative references to international publications with their corresponding European publications .16 Page3 EN607498:2003 INTRODUC
23、TION Activity within IEC technical committee 47, working group 2, includes the generation, coordination and review of climatic, electrical (of which only ESD, latch-up and electrical conditions for life tests are considered), mechanical test methods, and associated inspection techniques needed to as
24、sess the quality and reliability of the design and manufacture of semiconductor products and processes. Page4 EN607498:2003SEMICONDUCTOR DEVICES MECHANICAL AND CLIMATIC TEST METHODS Part 8: Sealing 1 Scope and object This part of IEC 60749 is applicable to semiconductor devices (discrete devices and
25、 integrated circuits) The object of this test method is to determine the leak rate of semiconductor devices. NOTE This test is identical to the test method contained in clause 5 of chapter 3 of IEC 60749 (1996), amendment 2, apart from the addition of this clause and clause 2 and the subsequent renu
26、mbering. 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 references, the latest edition of the referenced document (including any amendments) applies. IEC 60068-2-17:19
27、94, Environmental testing Part 2: Tests Test Q: Sealing 3 General terms 3.1 Units of pressure The International System of Units (SI) recommends the use of the Pascal (Pa) as the unit of pressure. The commonly used units are, however, the absolute atmosphere or the bar (where 1 absolute atmosphere =
28、1 bar = 10 5Pa). The unit used in this test method is the Pascal with the bar used as an alternative. 3.2 Standard leak rate The standard leak rate is defined as that quantity of dry air at 25 C in pascals (bars) cubic centimeters flowing through a leak or multiple leak paths per second when the hig
29、h-pressure side is at 10 5Pa (1 bar) and the low-pressure side is at a pressure of not greater than 10 2Pa (10 3bar). The standard leak rate shall be expressed in units of pascals cubic centimetres per second (bars cubic centimetres per second). 3.3 Measured leak rate The measured leak rate R (He)is
30、 defined as the leak rate of a given package as measured under specified conditions and employing a specified test medium. The measured leak rate shall be expressed in units of pascals cubic centimetres per second (bars cubic centimetres per second). For the purpose of comparison with rates determin
31、ed by other methods of testing, the measured leak rates must be converted to equivalent standard leak rates. Page5 EN607498:20033.4 Equivalent standard leak rate The equivalent standard leak rate (L) of a given package, with a measured leak rate R (He) , is defined as the leak rate of the same packa
32、ge with the same leak geometry, that would exist under the standard conditions of 3.2. The formula in 6.3 (which does not apply to test condition 5) represents the L/R ratio and gives the equivalent standard leak rate (L) of the package with a measured leak rate R (He) , where the package volume and
33、 leak test conditioning parameters influence the measured value of R (He) . The equivalent standard leak rate shall be expressed in units of units of pascals cubic centimetres per second (bars cubic centimeters per second). 4 Bomb pressure test Reference: IEC 60068-2-17. This test shall be in accord
34、ance with test Ql, with the following specific requirements: test liquid: 95 % methyl alcohol and 5 % water mixture, with addition of a detergent; temperature of the test liquid: 25 C 5 C; pressure: 4,510 5Pa (4,5 bar); duration of conditioning: 16 h; cleaning liquid: de-ionized water; recovery: bet
35、ween two days and two weeks. NOTE The use of this test is not recommended for semiconductor devices (see annex F to IEC 60068-2-17). 5 Fine leak detection: radioactive krypton method Reference: none. 5.1 Object To determine the leak rate of a semiconductor device by measuring the radiation level pre
36、sent within the device after it has been pressurized in a chamber with suitable radioactive tracer gas. This method is intended to be specified for devices which are designed to be hermetically sealed in glass, metal or ceramic (or combination thereof) encapsulations and is suitable for equivalent s
37、tandard leak rates smaller than 1 Pacm 3 s 1(10 5barcm 3 s 1 ). 5.2 General description 5.2.1 The numerical values given are applicable for krypton 85 tracer gas and for equivalent standard leak rate limit in the order of 5 10 3Pacm 3 s 1(5 10 8barcm 3 s 1 ). The use of other tracer gases would requ
38、ire other numerical values. Page6 EN607498:20035.2.2 Equipment Equipment for this test consists of a radioactive tracer activation tank and a counting station with sufficient sensitivity to determine the radiation level of the tracer gas inside the device. The equipment operates with a tracer gas mi
39、xture of dry nitrogen and krypton 85 with a specified activity (minimum: 100 Cicm 3 ) under standard atmospheric conditions. Instructions for the use of the leak testing equipment, as supplied by the manufacturer of the equipment, shall be followed in calibrating and operating the equipment. Test re
40、sults obtained under non-preferred conditions can be compared with those under preferred conditions by conversion through the appropriate formula given in these instructions. 5.2.3 Activation parameters The activation pressure and soak time shall be determined in accordance with the following equati
41、on (see note below): Tt P sk R Q = s(1) where Q sis the maximum leak rate allowable for the device to be tested, in Pacm 3 s 1(barcm 3 s 1 ) Kr; R is the counts per minute above the ambient background after activation if the device leak rate were exactly equal to Q s . This is the reject count above
42、 the background of both the counting equipment and the component if it has been through previous radioactive leak tests; s is the specific activity, in microcuries per cubic centimetresof the krypton 85 gas in the activation system; k is the overall counting efficiency of the scintillation crystal i
43、n counts per minute per one microcurie of krypton 85 in the internal cavity of the specific component being evaluated. This factor depends upon component configuration and dimensions of the scintillation crystal. The counting efficiency shall be determined in accordance with 5.2.4; P = P 2 e P 2 i ,
44、 where P eis the absolute activation pressure in pascals (bars) and P i is the original absolute internal pressure of the devices in pascals (bars). The activation pressure (P e ) may be established by specification, or if a convenient soak time (T) has been established, the activation pressure (P e
45、 ) can be adjusted to satisfy equation (1); T is the soak time that the devices are to be activated, in hours; t is the conversion of hours to seconds which is equal to 3 600 seconds/hour. NOTE The complete version of equation (1) contains a factor P 0 2 (P) 2in the numerator which is a correction f
46、actor for elevation above sea level. P 0is the sea level absolute pressure, in pascals (bars), and P is the difference in pressures, in pascals (bars), between the actual pressure at the test station and sea-level pressure. For the purposes of this test, this factor is neglected. 5.2.4 Determination
47、 of the counting efficiency (k) The counting efficiency (k) of equation (1) shall be determined as follows. a) A representative unit of the device type to be tested shall be provided with a tube to its internal cavity and the cavity shall be backfilled through the tube with known volume and specific
48、 activity of krypton 85 tracer gas and the tubulation should be sealed off. Page7 EN607498:2003b) The counts per minute in the shielded scintillation crystal of the counting station in which the devices are tested shall be directly read. From this value, the counting efficiency in counts per minute
49、per microcurie shall be calculated. 5.2.5 Evaluation of the surface sorption For each type of encapsulation to be tested, the coatings and external sealants shall be evaluated for surface sorption of krypton 85 before establishing the leak test parameters. Representative samples of the devices shall be subjected to the predetermined pressure and time conditions established for
