1、BSI Standards PublicationBS ISO 16525-2:2014Adhesives Test methods for isotropic electrically conductive adhesivesPart 2: Determination of electrical characteristics for use in electronic assembliesBS ISO 16525-2:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of
2、 ISO 16525-2:2014.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/52, Adhesives.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Use
3、rs are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 74568 3ICS 83.180Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theS
4、tandards Policy and Strategy Committee on 31 May 2014.Amendments issued since publicationDate Text affectedBS ISO 16525-2:2014 ISO 2014Adhesives Test methods for isotropic electrically conductive adhesives Part 2: Determination of electrical characteristics for use in electronic assembliesAdhsifs Mt
5、hodes dessai pour adhsifs conductivit lectrique isotrope Partie 2: Dtermination des proprits lectriques pour utilisation dans des assemblages lectroniquesINTERNATIONAL STANDARDISO16525-2First edition2014-05-15Reference numberISO 16525-2:2014(E)BS ISO 16525-2:2014ISO 16525-2:2014(E)ii ISO 2014 All ri
6、ghts reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2014All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without pri
7、or written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS
8、 ISO 16525-2:2014ISO 16525-2:2014(E) ISO 2014 All rights reserved iiiContents PageForeword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 25 Apparatus . 36 Procedure. 86.1 Atmospheric conditions 86.2 Measurement and calculation 86.3 Judgement 107 Test report 11BS ISO 165
9、25-2:2014ISO 16525-2:2014(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested
10、 in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Comm
11、ission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents s
12、hould be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2. www.iso.org/directivesAttention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identi
13、fying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received. www.iso.org/patentsAny trade name used in this document is information given for the convenience of
14、users and does not constitute an endorsement. The committee responsible for this document is ISO/TC 61, Plastics, Subcommittee SC 11, Products.ISO 16525 consists of the following parts, under the general title Adhesives Test methods for isotropic electrically conductive adhesives: Part 1: General te
15、st methods Part 2: Determination of electric characteristics for use in electronic assemblies Part 3: Determination of heat-transfer properties Part 4: Determination of shear strength and electrical resistance using rigid-to-rigid bonded assemblies Part 5: Determination of shear fatigue Part 6: Dete
16、rmination of pendulum-type shear impact Part 7: Environmental test methods Part 8: Electrochemical migration test methods Part 9: Determination of high-speed signal-transmission characteristicsiv ISO 2014 All rights reservedBS ISO 16525-2:2014INTERNATIONAL STANDARD ISO 16525-2:2014(E)Adhesives Test
17、methods for isotropic electrically conductive adhesives Part 2: Determination of electrical characteristics for use in electronic assembliesSAFETY STATEMENT Persons using this part of ISO 16525 should be familiar with normal laboratory practice. This part of ISO 16525 does not purport to address all
18、 of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any regulatory conditions.IMPORTANT Certain procedures specified in this part of ISO 16525 might involve the use or genera
19、tion of substances, or the generation of waste, that could constitute a local environmental hazard. Reference should be made to appropriate documentation on safe handling and disposal after use.1 ScopeThis part of ISO 16525 specifies test methods for isotropic electrically conductive adhesives used
20、in wiring, die attach, and surface assembly of printed circuit boards of electronic devices. The test methods focus on volume and interfacial contact resistivity.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for
21、its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 472, Plastics VocabularyISO 554, Standard atmospheres for conditioning and/or testing SpecificationsISO 80000-1, Quantit
22、ies and units Part 1: GeneralIEC 60468, Method of measurement of resistivity of metallic materialsIEC 61249-2-7, Materials for printed boards and other interconnecting structures - Part 2-7: Reinforced base materials clad and unclad - Epoxide woven E-glass laminated sheet of defined flammability (ve
23、rtical burning test), copper-cladEN 923, Adhesives Terms and definitionsASTM B539-02, Standard Test Methods for Measuring Resistance of Electrical Connections (Static Contacts)3 Terms and definitionsFor the purposes of this document, the terms and definitions given in ISO 472, ASTM B539-02 and EN 92
24、3 and the following apply. ISO 2014 All rights reserved 1BS ISO 16525-2:2014ISO 16525-2:2014(E)3.1isotropic electrically conductive adhesiveresin that contains fillers, which provide electrical conduction, and functions as an adhesive3.2volume resistivityelectrical resistance of the isotropic electr
25、ically conductive adhesive for a given cross-sectional area or given lengthNote 1 to entry: Electrical volume resistivity is converted to resistance per given cross-sectional area or given length of the isotropic electrically conductive adhesive. This part of ISO 16525 specifies measurement methods
26、for an isotropic electrically conductive adhesive, which is applied to a circuit board that is similar to the one used in practice.Note 2 to entry: It is expressed as ohm metre (m).3.3interfacial contact resistivityielectrical resistance that is generated on the contact surface between the isotropic
27、 electrically conductive adhesive and the adherend Note 1 to entry: It is expressed as electrical resistance per given cross-sectional area (m2).Note 2 to entry: Interfacial contact resistance is generated on the contact surface between the isotropic electrically conductive adhesive and the electrod
28、e, and it is thought to be associated with the dispersion of the metal component in the vicinity of the electrode interface, oxide film, and the arrangement of conductive particles contained in the isotropic electrically conductive adhesive. In addition, interfacial contact resistivity fluctuates du
29、ring the endurance test. Apart from the resistance component brought by electrically volume resistivity of the isotropic electrically conductive adhesive, if a resistance component is placed on the contact surface, interfacial resistance is expressed by resistivity per given area and is converted to
30、 resistance per given cross-sectional area or length of the isotropic electrically conductive adhesive.3.4four-probe methodmethod for measuring resistance that consists of two terminals for current application and two terminals for voltage measurement3.5dry circuitmethod for measuring resistance tha
31、t prevents open-circuit voltage at the time of measurement from exceeding a specific level so that the thin insulating layer that develops at the contact surface cannot be brokenNote 1 to entry: The maximum current limit is 100 mA and voltage is 20 mV in order to prevent breakdown of the microstruct
32、ure of adhesives.4 PrincipleThe test circuit board consists of two or more terminals that are connected using an isotropic electrically conductive adhesive. The measurement of a potential difference, when a current is applied to one of the terminals, can be used for the calculation of electrically v
33、olume resistivity and interfacial contact resistivity.NOTE This test uses the electrical characteristics of isotropic electrically conductive adhesives, which are used for connection of electronic circuits. This part of ISO 16525 describes electrically volume resistivity, which shows the electric ch
34、aracteristic of the isotropic electrically conductive adhesive, and interfacial resistance, which is specific to the isotropic electrically conductive adhesive.2 ISO 2014 All rights reservedBS ISO 16525-2:2014ISO 16525-2:2014(E)On the contact surface of the isotropic electrically conductive adhesive
35、s, a resistance component is present, which can be regarded as interfacial resistance. This might be so high that it cannot be neglected when compared with electrically volume resistivity of the isotropic electrically conductive adhesive. This test provides a measurement, which measures this compone
36、nt only. This test is characterized by calculation of resistivity from a current passing through the test circuit and voltage.5 Apparatus5.1 Test apparatus, consisting of a current source and a voltage meter, both as specified in IEC 60468. The potential difference is measured at the voltage termina
37、ls by applying a current to the printed circuit board using the current source from the current terminals in a specific direction. Figure 1 and Figure 2 show examples of configuration of the apparatus. A digital ohmmeter, which combines all these devices, may be used as an alternative.It is preferab
38、le to use a dry circuit-type apparatus because it does not affect the irreversibility of conductivity of the interface of the isotropic electrically conductive adhesive. For measurement of interfacial resistance, it is preferable to use a multichannel ohmmeter because it is necessary to switch from
39、one pair of terminals to the other and the lengths of the wires differs.Resistance is obtained from the voltage drop when a constant current is applied. Therefore, set a current value so that voltage resolution can be sufficiently small compared to the measured voltage. In the unlikely event that th
40、e specimen generates heat because an excessively high current occurs, reduce the current value and shorten the period for each measurement session. Usually, a maximum current is recommended to be approximately 10 mA.Key1 ohmmeter 5 current probe2 current source terminal 6 voltage probe3 voltage meas
41、urement terminal 7 resistance, R4 test circuit board Figure 1 Test apparatus For measurement of electrically volume resistivity ISO 2014 All rights reserved 3BS ISO 16525-2:2014ISO 16525-2:2014(E)Key1 multichannel ohmmeter 7 channel switch2 current source terminal 8 resistance 1, R13 voltage measure
42、ment terminal 9 resistance 2, R24 test circuit board 10 resistance 3, R35 current probe 11 resistance 4, R46 voltage probe Figure 2 Test apparatus For measurement of interfacial contact resistivity5.2 Test circuit board, fulfilling the following requirments.a) Material of substrate: use a glass fabr
43、ic-based epoxy resin copper-clad laminate specified as a general-purpose, single-sided substrate, as described in IEC 61249-2-7.b) Thickness of substrate: the thickness of substrates is (1,6 0,2) mm or that specified in IEC 61249-2-7.c) Pattern and dimensions of circuit board: a basic pattern for ci
44、rcuit boards to measure electrically volume resistivity and interfacial contact resistivity is shown in Figure 3 (for measurement of electrically volume resistivity) and Figure 4 (for measurement of interfacial contact resistivity), respectively.The allowed values for dimension a in Figure 3 are fro
45、m 2 mm to 10 mm and for l are from 20 mm to 100 mm. For workability, the recommended values for dimensions a and l are 10 mm and 50 mm, respectively. Diameter, b, of the wire for measuring a voltage drop should be so thin that it does not affect the measurement and is recommended to be 0,5 mm.The re
46、commended dimension for a in Figure 4 is 0,8 mm. When dimension a is lower than this value, fluctuation of the measurement becomes large. When it is larger than this value, the measurement sensitivity for interfacial resistance is reduced. The wires connected to the joint, at which measurement is pe
47、rformed, are taken out from both ends so that the current distribution at the location of measurement 4 ISO 2014 All rights reservedBS ISO 16525-2:2014ISO 16525-2:2014(E)will be uniform. Dimension b should be as small as possible so that it does not affect measurement of a voltage drop and is recomm
48、ended to be 0,1 mm.These dimensions should be observed because they are designed to minimize their impacts on measurement.d) Plating of the electrode surface of the circuit board: in Figure 3, an antioxidant should be applied to the substrate to prevent oxidation of copper and other metals. In Figur
49、e 4, plating of the electrode surface is subject to requirements for uses and/or requirements of the delivering and receiving parties. ISO 2014 All rights reserved 5BS ISO 16525-2:2014ISO 16525-2:2014(E)Key1 isotropic conductive adhesives (ICA) 6 current sources2 adhesion area (back/rear) 7 width of ICA line, a3 metal strip line 8 width of voltage line, b4 wire attachment pad 9 width of current source line, c5 vo
