EN 62319-1:2005

Polymeric thermistors - Directly heated positive step function temperature coefficient - Part 1: Generic specification

Prescribes terms and methods of test for polymeric positive temperature coefficient thermistors, insulated and non-insulated types, typically intended for use in current limiting and overcurrent protection applications. It establishes standard terms, inspection procedures and methods of test for use in detail specifications for Qualification Approval and for Quality Assessment Systems for electronic components.

Temperaturabhängige Widerstände aus Polymerwerkstoffen - Direkt geheizte temperaturabhängige Widerstände mit positivem Temperaturkoeffizienten - Teil 1: Fachgrundspezifikation

Thermistances polymères - Coefficient de température positif de fonction échelon à chauffage direct - Partie 1: Spécification générique

Prescribes terms and methods of test for polymeric positive temperature coefficient thermistors, insulated and non-insulated types, typically intended for use in current limiting and overcurrent protection applications. It establishes standard terms, inspection procedures and methods of test for use in detail specifications for Qualification Approval and for Quality Assessment Systems for electronic components.

Polimerni termistorji – Neposredno ogrevani s pozitivnim temperaturnim koeficientom – 1. del: Generična specifikacija (IEC 62319-1:2005)

General Information

• Status: Published
• Publication Date: 10-Mar-2005
• ICS: 31.040.30 - Thermistors
• Technical Committee: CLC/SR 40 - Capacitors and resistors for electronic equipment
• Drafting Committee: IEC/TC 40 - IEC_TC_40
• Parallel Committee: IEC/TC 40 - IEC_TC_40
• Current Stage: 6060 - Document made available - Publishing
• Start Date: 11-Mar-2005
• Completion Date: 11-Mar-2005
• Ref Project: SIST EN 62319-1:2005 - Polymeric thermistors - Directly heated positive step function temperature coefficient -- Part 1: Generic specification

Standards Content (Sample)

STANDARDPolimerni termistorji – Neposredno ogrevani s pozitivnim temperaturnim koeficientom – 1. del: Generična specifikacija (IEC 62319-1:2005)Polymeric thermistors – Directly heated positive step function temperature coefficient – Part 1: Generic specification (IEC 62319-1:2005)©
Standard je založil in izdal Slovenski inštitut za standardizacijo. Razmnoževanje ali kopiranje celote ali delov tega dokumenta ni dovoljenoReferenčna številkaSIST EN 62319-1:2005(en)ICS31.040.30

EUROPEAN STANDARD
EN 62319-1 NORME EUROPÉENNE EUROPÄISCHE NORM
March 2005 CENELEC European Committee for Electrotechnical Standardization Comité Européen de Normalisation Electrotechnique Europäisches Komitee für Elektrotechnische Normung
Central Secretariat: rue de Stassart 35, B - 1050 Brussels
© 2005 CENELEC - All rights of exploitation in any form and by any means reserved worldwide for CENELEC members.
Ref. No. EN 62319-1:2005 E
ICS 31.040.30
English version
Polymeric thermistors -
Directly heated positive step function temperature coefficient Part 1: Generic specification (IEC 62319-1:2005)
Thermistances polymères -
Coefficient de température positif
de fonction échelon à chauffage direct Partie 1: Spécification générique (CEI 62319-1:2005)
Temperaturabhängige Widerstände
aus Polymerwerkstoffen -
Direkt geheizte temperaturabhängige Widerstände mit positivem Temperaturkoeffizienten Teil 1: Fachgrundspezifikation (IEC 62319-1:2005)
This European Standard was approved by CENELEC on 2005-02-01. CENELEC members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions 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 Central Secretariat or to any CENELEC member.
This European Standard exists 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 Central Secretariat has the same status as the official versions.
CENELEC members are the national electrotechnical committees of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.

at national level by publication of an identical
national standard or by endorsement
(dop)
2005-12-01 – latest date by which the national standards conflicting
with the EN have to be withdrawn
(dow)
2008-02-01 Annex ZA has been added by CENELEC. __________ Endorsement notice The text of the International Standard IEC 62319-1:2005 was approved by CENELEC as a European Standard without any modification. __________

- 3 - EN 62319-1:2005
Annex ZA
(normative)
Normative references to international publications
with their corresponding European publications 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. NOTE Where an international publication has been modified by common modifications, indicated by (mod), the relevant EN/HD applies. Publication Year Title EN/HD Year IEC 60027-1
- 1) Letter symbols to be used in electrical technology Part 1: General
HD 60027-1 2004 2) IEC 60050 Series International Electrotechnical Vocabulary EN 60050 Series IEC 60068-1 - 1) Environmental testing Part 1: General and guidance
EN 60068-1 1994 2) IEC 60068-2-6 - 1) Part 2: Tests - Test Fc: Vibration (sinusoidal)
EN 60068-2-6 1995 2) IEC 60068-2-14 - 1) Part 2: Tests - Test N: Change of temperature
EN 60068-2-14 1999 2) IEC 60068-2-20 - 1) Part 2: Tests - Test T: Soldering
HD 323.2.20 S3 1988 2) IEC 60068-2-21 - 1) Part 2-21: Tests - Test U: Robustness of terminations and integral mounting devices
EN 60068-2-21 1999 2) IEC 60068-2-27 - 1) Part 2: Tests - Test Ea and guidance: Shock
EN 60068-2-27 1993 2) IEC 60068-2-29 - 1) Part 2: Tests - Test Eb and guidance: Bump
EN 60068-2-29 1993 2) IEC 60068-2-45 - 1) Part 2: Tests - Test Xa and guidance: Immersion in cleaning solvents
EN 60068-2-45 1992 2) IEC 60294 - 1) Measurement of the dimensions of a cylindrical component having two axial terminations
- - IEC 60410 - 1) Sampling plans and procedures for inspection by attributes
- - IEC 60617
database Graphical symbols for diagrams
- -
1) Undated reference.
2) Valid edition at date of issue.

- - IECQ 001003 - 1) IEC Quality Assessment System for Electronic Components (IECQ) - Guidance documents
- - ISO 1000 - 1) SI units and recommendations for the use of their multiples and of certain other units
- -
INTERNATIONAL STANDARD IEC62319-1 First edition2005-02 Polymeric thermistors – Directly heated positive step function temperature coefficient – Part 1: Generic specification
 IEC 2005

Copyright - all rights reserved No part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Electrotechnical Commission,
3, rue de Varembé, PO Box 131, CH-1211 Geneva 20, SwitzerlandTelephone: [phone] Telefax: [phone] E-mail: [e-mail]
Web: www.iec.ch V For price, see current catalogue PRICE CODE
Commission Electrotechnique InternationaleInternational Electrotechnical Commission

– 2 – 62319-1  IEC:2005(E) CONTENTS FOREWORD.4
1 General.6 1.1 Scope.6 1.2 Normative references.6 2 Technical data.7 2.1 Units and symbols.7 2.2 Terms and definitions.7 2.3 Preferred values.10 2.4 Marking.11 3 Quality assessment procedures.11 3.1 General.11 3.2 Primary stage of manufacture.11 3.3 Subcontracting.12 3.4 Structurally similar components.12 3.5 Qualification approval procedures.12 3.6 Rework and repair.18 3.7 Release for delivery.18 3.8 Certified test records of released lots.19 3.9 Delayed delivery.19 3.10 Alternative test methods.19 3.11 Manufacture outside the geographical limits of IECQ NSIs.19 3.12 Unchecked parameters.19 4 Test and measurement procedures.19 4.1 Standard conditions for testing.19 4.2 Drying and recovery.20 4.3 Visual inspection and check of dimensions.20 4.4 Zero power resistance.21 4.5 Insulation resistance (for insulated types only).21 4.6 Voltage proof (for insulated types only).22 4.7 Robustness of terminations (for leaded types only).22 4.8 Soldering.23 4.9 Mounting.23 4.10 Rapid change of temperature.24 4.11 Climatic sequence.24 4.12 Cycle life testing.25 4.13 Trip endurance.27 4.14 Trip current.28 4.15 Hold current.28 4.16 Residual current and power dissipation.29 4.17 Time-to-trip.29 4.18 Cold environmental electrical cycling.30 4.19 Thermal runaway.30

62319-1  IEC:2005(E) – 3 – Annex A (normative)
Fixed sample size test schedules for qualification approval.31 Annex B (normative)
Vibration-, bump-, shock-, shear-, substrate bending test.32 B.1 Vibration.32 B.2 Bump.32 B.3 Shock.33 B.4 Shear (adhesion) test.33 B.5 Substrate bending test.33
Figure 1 – Test schedule flow chart.15 Figure 2 – Circuit for Trip endurance.28
Table 1 – Fixed sample size test schedule for qualification approval of Polymeric PTC thermistors for current limitation, assessment level EZ.16 Table 2 – Quality conformance inspection for lot-by-lot inspection.17 Table 3 – Quality conformance inspection for periodic testing.18 Table 4 – Loading weight for wire terminations.22 Table 5 – Number of cycles.25

– 4 – 62319-1  IEC:2005(E) INTERNATIONAL ELECTROTECHNICAL COMMISSION ____________
POLYMERIC THERMISTORS – DIRECTLY HEATED POSITIVE STEP FUNCTION
TEMPERATURE COEFFICIENT – Part 1: Generic specification
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 to promote international co-operation on all questions concerning standardization in the electrical and electronic fields. To this end and in addition to other activities, IEC publishes International Standards, Technical Specifications, Technical Reports, Publicly Available Specifications (PAS) and Guides (hereafter referred to as “IEC Publication(s)”). Their preparation is entrusted to technical committees; any IEC National Committee interested in the subject dealt with may participate in this preparatory work. International, governmental and non-governmental organizations liaising with the IEC also participate in this preparation. IEC collaborates closely with the International Organization for Standardization (ISO) in accordance with conditions determined by agreement between the two organizations. 2) The formal decisions or agreements of IEC on technical matters express, as nearly as possible, an international consensus of opinion on the relevant subjects since each technical committee has representation from all interested IEC National Committees.
3) IEC Publications have the form of recommendations for international use and are accepted by IEC National Committees in that sense. While all reasonable efforts are made to ensure that the technical content of IEC Publications is accurate, IEC cannot be held responsible for the way in which they are used or for any misinterpretation by any end user. 4) In order to promote international uniformity, IEC National Committees undertake to apply IEC Publications transparently to the maximum extent possible in their national and regional publications. Any divergence between any IEC Publication and the corresponding national or regional publication shall be clearly indicated in the latter. 5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any equipment declared to be in conformity with an IEC Publication. 6) All users should ensure that they have the latest edition of this publication. 7) No liability shall attach to IEC or its directors, employees, servants or agents including individual experts and members of its technical committees and IEC National Committees for any personal injury, property damage or other damage of any nature whatsoever, whether direct or indirect, or for costs (including legal fees) and expenses arising out of the publication, use of, or reliance upon, this IEC Publication or any other IEC Publications.
8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is indispensable 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 62319-1 has been prepared by IEC technical committee 40: Capacitors and resistors for electronic equipment. The text of this standard is based on the following documents: FDIS Report on voting 40/1505/FDIS 40/1534/RVD
Full information on the voting for the approval of this standard can be found in the report on voting indicated in the above table. This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.

62319-1  IEC:2005(E) – 5 – The committee has decided that the contents of this publication will remain unchanged until the maintenance result date indicated on the IEC web site under "http://webstore.iec.ch" in the data related to the specific publication. At this date, the publication will be
• reconfirmed; • withdrawn; • replaced by a revised edition, or • amended.
A bilingual version of this publication may be issued at a later date.

– 6 – 62319-1  IEC:2005(E) POLYMERIC THERMISTORS – DIRECTLY HEATED POSITIVE STEP FUNCTION
TEMPERATURE COEFFICIENT –
Part 1: Generic specification
1 General 1.1 Scope This part of IEC 62319 prescribes terms and methods of test for polymeric positive temperature coefficient thermistors, insulated and non-insulated types, typically intended for use in current limiting and overcurrent protection applications. It establishes standard terms, inspection procedures and methods of test for use in detail specifications for Qualification Approval and for Quality Assessment Systems for electronic components.
1.2 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 60027-1: Letter symbols to be used in electrical technology – Part 1: General IEC 60050: International Electrotechnical Vocabulary IEC 60068-1: Environmental testing – Part 1: General and guidance IEC 60068-2-6: Environmental testing – Part 2: Tests – Test Fc: Vibration (sinusoidal)
IEC 60068-2-14: Environmental testing – Part 2: Tests – Test N: Change of temperature
IEC 60068-2-20: Environmental testing – Part 2: Tests – Test T: Soldering
IEC 60068-2-21: Environmental testing – Part 2-21: Tests – Test U: Robustness of terminations and integral mounting devices IEC 60068-2-27: Environmental testing – Part 2: Tests – Test Ea and guidance: Shock IEC 60068-2-29: Environmental testing – Part 2: Tests – Test Eb and guidance: Bump IEC 60068-2-45: Environmental testing – Part 2: Tests – Test XA and guidance: Immersion in cleaning solvents IEC 60294: Measurement of the dimensions of a cylindrical component having two axial terminations IEC 60410: Sampling plans and procedures for inspection by attributes.

62319-1  IEC:2005(E) – 7 – IEC 60617-DB: 20011 Graphical symbols for diagrams IECQ 001003: IEC Quality Assessment System for Electronic Components – Guidance documents IECQ 001002-3: IEC Quality Assessment System for Electronic Components – Rules of Procedure – Part 3: Approval procedures ISO 1000: SI units and recommendations for the use of their multiples and of certain other units 2 Technical data 2.1 Units and symbols Units, graphical symbols, letter symbols and terminology shall, whenever possible, be taken from the following documents: IEC 60027 IEC 60050 IEC 60617 ISO 1000 The following subclauses contain additional terminology applicable to thermistors. Where further items are required they shall be derived in accordance with the principles of the documents listed above. 2.2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.2.1 thermistor thermally sensitive semiconducting resistor whose primary function is to exhibit an important change in electrical resistance with a change in body temperature 2.2.2 positive temperature coefficient thermistor thermistor in which the resistance increases with increasing temperature throughout the useful part of its characteristic. The PTC thermistors covered in this specification typically exhibit a very sharp increase in resistance over a narrow temperature range 2.2.3 directly heated positive temperature coefficient thermistor thermistor in which the change in temperature is obtained either by the flow of current through the thermo-sensitive element, or by a change in ambient temperature, or by a combination of both of these means ___________ 1 “DB” refers to the IEC on-line database.

– 8 – 62319-1  IEC:2005(E) 2.2.4 zero power resistance
RT value of the resistance of a PTC thermistor, at a given temperature, under such conditions that the change in resistance due to the internal generation of heat is negligible with respect to the total error of measurement NOTE Any resistance value of a PTC thermistor is dependent on the value and the mode of the applied voltage (AC or DC).
2.2.5 nominal zero power resistance
Rn zero power resistance used as a reference value for which the following conditions should be given in the detail specification: a) reference temperature, preferably 25 °C b) applied voltage (DC or AC) 2.2.6 resistance/temperature characteristics relationship between the zero power resistance of a thermistor and the temperature of the thermosensitive element when measured under specified reference conditions 2.2.7 upper category temperature
UCT maximum ambient operating temperature of the thermistor 2.2.8 lower category temperature
LCT minimum ambient operating temperature of the thermistor 2.2.9 trip event event of rapid increasing resistance of the thermistor in response to an overcurrent surge
2.2.10 minimum initial resistance
Rmin minimum resistance of the thermistor 2.2.11 maximum initial resistance
Rmax maximum resistance of the thermistor before it’s initial trip event 2.2.12 maximum resistance 1 h after tripping
R1max for leaded thermistors the maximum resistance of the thermistor 1 h after it’s first trip event; for surface mount thermistors, the maximum resistance of the thermistor 1 h after reflow 2.2.13 maximum voltage
Umax maximum AC or DC voltage which may be applied to the thermistor

62319-1  IEC:2005(E) – 9 – 2.2.14 operating temperature range at maximum voltage range of ambient temperatures at which the thermistor can operate at the maximum voltage 2.2.15 isolation voltage (applicable only to insulated thermistors) maximum peak voltage which may be applied under continuous operating conditions between any of the thermistor terminations and any conducting surface 2.2.16 maximum current
Imax value of current for the operating temperature range, which should not be exceeded 2.2.17 residual current
Ires value of current in the tripped thermistor at a specified ambient temperature (preferably 25 °C) under steady state conditions; the applied voltage is the maximum voltage unless otherwise specified 2.2.18 trip current
It lowest current which will cause the thermistor to trip to its high resistance state at a specified temperature (preferably 25 °C) and within a time specified in the detail specification 2.2.19 hold current
Ih the maximum current at specified ambient temperature, preferably 25 °C, which will not cause the trip event 2.2.20 fault current
Ifault current used when measuring time to trip 2.2.21 power dissipation
Pd product of the current flowing through a device and the voltage across it, under steady state conditions; the applied voltage is the maximum voltage unless otherwise specified 2.2.22 time-to-trip
ttrip under specified ambient conditions, starting from the time the fault current (Ifault) is applied, the time-to-trip is the time required for a device to switch into the tripped state 2.2.23 insulated thermistors thermistors capable of meeting the requirements of the insulation resistance and voltage proof tests when specified in the test schedule

– 10 – 62319-1  IEC:2005(E) 2.3 Preferred values 2.3.1 Climatic categories The thermistors covered by this specification are classified into climatic categories according to the general rules given in the annex to IEC 60068-1. The detail specification prescribes the appropriate category. 2.3.2 Bump test severities The test severity given in the detail specification shall preferably be the following: Test Eb (IEC 60068-2-29) Acceleration: 400 m/s2 Number of bumps: 4 000 total. Thermistors shall be mounted by their normal means, in such a manner that there shall be no parasitic vibration. 2.3.3 Shock test severities Test severities given in detail specifications shall preferably be the following: Test Ea (IEC 60068-2-27) Pulse shape: Half sine Acceleration: 500 m/s2 Pulse duration: 11 ms. Severity: 3 successive shocks in each axis direction per specimen. Separate specimens to be used for each axis (6 shocks total per specimen). NOTE The shock and bump tests are normally specified as alternatives. 2.3.4 Vibration severities Test severities given in the detail specifications shall preferably be selected from the following: Test Fc (IEC 60068-2-6) Frequency range: 10 Hz to 55 Hz or 10 Hz to 500 Hz Amplitude: 0,75 mm or 98 m/s2 (whichever is the less severe) Sweep endurance: Total duration 6 h. Thermistors shall be mounted by their normal means, in such a manner that there shall be no parasitic vibration. During vibration testing there shall be no interruption in electrical continuity greater than 0,5 ms.

62319-1  IEC:2005(E) – 11 – 2.4 Marking 2.4.1 General The following shall be clearly marked on the thermistor in the following order of precedence as space permits: a) values of the primary characteristics appropriate to the application of the thermistor to be specified in the detail specification. When these values are coded (including colour coding), details shall be given in the detail specification or type designation; b) manufacturer's name and/or trade mark; c) date of manufacture or date code; d) the number of the detail specification and style. The package containing the thermistors shall be clearly marked with all the information listed above. Any additional marking shall be so applied that no confusion can arise. 3 Quality assessment procedures 3.1 General When these documents are being used for the purposes of a full quality assessment system such as the IEC Quality Assessment System for Electronic Components (IECQ), compliance with 3.5 is required. When these documents are used outside such quality assessment systems for purposes such as design proving or type testing, the procedures and requirements of 3.5.1 and 3.5.3 b) may be used, but if used, the test and parts of tests shall be applied in the order given in the test schedule. Before thermistors can be qualified according to the procedures of this clause, the manufacturer shall obtain the approval of his organisation in accordance with the provisions of IECQ 001002-3. The method for the approval of thermistors of assessed quality given in 3.5 is qualification approval according to the provisions of Clause 3 of IECQ 001002-3. 3.1.1 Applicability of qualification approval Qualification approval is appropriate for a standard range of thermistors manufactured to similar design and production processes and conforming to a published detail specification. The programme of tests defined in the detail specification for the appropriate assessment and performance levels applies directly to the subfamily of thermistors to be qualified, as prescribed in 3.5 and the relevant blank detail specification. 3.2 Primary stage of manufacture The primary stage of manufacture is defined as the initial compounding process of the ingredients.

– 12 – 62319-1  IEC:2005(E) 3.3 Subcontracting If subcontracting of the primary stage of manufacture and/or subsequent stages is employed it shall be in accordance with 4.2.2 of IECQ 001002-3. The blank detail specification may restrict subcontracting in accordance with 4.2.2.2 of IECQ 001002-3. 3.4 Structurally similar components Thermistors may be grouped as structurally similar for the purpose of forming inspection lots provided the following requirements are met: a) they shall be produced by one manufacturer on one site using essentially the same design, materials, processes and methods; b) the sample taken shall be determined from the total lot size of the grouped devices; c) structurally similar devices should preferably be included in one detail specification but the details of all claims to structural similarity shall be declared in the qualification approval test reports. 3.4.1 For electrical tests, devices having the same electrical characteristics may be grouped provided the element determining the characteristic is similar for all the devices concerned. 3.4.2 For environmental tests, devices having the same
type of insulation, basic internal structure and finishing processes may be grouped. 3.4.3 For visual inspection (except marking), devices may be grouped if they have been made on the same production line, have the same dimensions, type of insulation and external finish. This grouping may also be used for robustness of terminations and soldering tests where it is convenient to group devices with different internal structures. 3.4.4 For endurance tests, thermistors may be grouped if they have been made on the same production line using the same design and differing only in electrical characteristics. If it can be shown that one type from the group is more heavily stressed than the others then tests on this type may be accepted for the remaining members of the group. 3.5 Qualification approval procedures 3.5.1 Eligibility for qualification approval The manufacturer shall comply with 3.1.1 of IECQ 001002-3. 3.5.2 Application of qualification approval The manufacturer shall comply with 3.1.3 of IECQ 001002-3. 3.5.3 Test procedures for qualification approval One of the two following procedures shall be followed: a) the manufacturer shall produce test evidence of conformance to the specification requirements on three inspection lots for lot-by-lot inspection taken in as short a time as possible and one lot for periodic inspection. No major changes in the manufacturing process shall be made in the period during which the inspection lots are taken.

62319-1  IEC:2005(E) – 13 –
Samples shall be taken from the lots in accordance with IEC 60410. Normal inspection shall be used, but when the sample size would give acceptance on zero non-conformances, additional specimens shall be taken to meet the sample size requirements to give acceptance on one non-conforming item. b) the manufacturer shall produce test evidence to show conformance to the specification requirements on the fixed sample size test schedule given in 3.5.4. The specimens taken to form the sample shall be selected at random from current production or as agreed with the National Supervising Inspectorate (NSI). For the two procedures, the same sample sizes shall be of comparable order. The test conditions and requirements shall be the same. 3.5.4 Qualification approval on the basis of the fixed sample size procedure The fixed sample size test schedule for qualification approval given hereinafter is appropriate to the intended application of the thermistor that is to be approved. The schedule provides information on the test grouping and sampling and acceptance criteria. The conditions of test and the end of test requirements shall be identical to those specified in the related blank detail specification for the lot-by-lot and periodic tests. Tests The complete series of tests specified in Table 1 are required for the approval of thermistors covered by the detail specification. The tests of each group shall be carried out in the order given. The whole sample shall be subjected to the tests of Group 0 and then divided for the other groups. Non-conforming specimens during the tests of Group 0 shall not be used for the other groups. “One non-conforming item” is counted when a thermistor has not satisfied the whole or a part of the tests of a group. The approval is granted when the number of non-conformances does not exceed the specified number of permissible non-conforming items for each group or subgroup and the total number of permissible non conformances. The following list applies to
the test schedule detailed in Table 1: a) clause number references are to clauses in this specification; b) 1) where the test schedule of a blank detail specification omits a test, that test may be omitted from the fixed sample size schedule in this specification;
2) where additional tests are specified in the detail specification, that test shall be included in the fixed sample schedule, either by its addition to an existing group or, by the addition of another group. In the former case there shall be no change in the number of specimens to be tested or in the acceptance criteria. In the latter case the number of specimens to be tested and the acceptance criteria shall be comparable to those already specified; c) in this table:
n
is the sample size;
c
is the group acceptance criteria (permitted number of defectives per group);
D indicates a destructive test;
ND indicates a non-destructive test;

– 14 – 62319-1  IEC:2005(E) d) the temperature at which the zero power resistance shall be measured is specified in the detail specification. The temperature shall be stated, where required, in the test schedule; e) data for conditions of test are defined in the detail specification; f) the additional specimens are to permit substitution for incidents not attributable to the manufacturer. The specimens may be used to replace non-conforming specimens which occur as a result of a test in a group which is identified as being “destructive”. Where a specimen is used for this purpose, it shall be subjected to those tests in the group to which the non-conforming item had already been subjected, before proceeding with the remaining tests in the group; g) the specimens used for this group may, at the discretion of the manufacturer, be used for any subsequent group which is identified as being “destructive”; h) ten samples from Group 0 test samples have to be chosen, 5 having the lowest zero power resistance of the samples shall be used for Group 1A, 5 having the highest zero power resistance of the samples for Group 1B; i) the soldering – solderability and soldering – resistance to soldering heat tests shall only be applied where the thermistor has terminations which are appropriate for soldering; j) where the terminations are stated to be suitable for printed wiring applications, the appropriate test conditions in IEC 60068 shall apply; k) the thermistors shall be mounted by their normal means; l) the vibration, bump and shock tests are only conducted if required in the detail specification.

62319-1  IEC:2005(E) – 15 –
Vibration, bump and shock tests are not required but may be performed to obtain supplementary information. Figure 1 – Test schedule flow chart Group 0
80 pcs (+5 spare)
Tests
Visual Marking
Zero power resistance
Non Destructive
Group 1
Destructive
Group 2
Destructive Group 3 Destructive Group 4 Non Destructive Group 5 Destructive Group 6 Destructive Group 7 Destructive Group 8 Destructive Group 9 Destructive Group 10 Destructive Trip
current Hold current (Power dissipation at I hold Residual current and Power dissipation Voltage proof 5 pcs 5 pcs Solder heatRobustness Vibration Bump (or)shock5 pcs 5 pcs
Rapid temp.change10 pcs Detail Dimens. 10 pcs Cycle life 10 pcs Trip
endurance10 pcsClimaticsequence10 pcs Cold envir.electr. cycling 10 pcs Thermalrunaway 10 pcs Solderability10 pcs IEC
218/05
– 16 – 62319-1  IEC:2005(E) Table 1 – Fixed sample size test schedule for qualification approval of polymeric PTC thermistors for current limitation, assessment level EZ Group No Test Clause/subclause of this standard D or ND Number of specimens
n Permissible number of non-conforming items c 0 Visual examination Marking Zero power resistance 4.3.1 4.3.2 4.4 ND 80 + 5 0 1 1A
1B
Trip current Residual current and power dissipation Voltage proof
Hold current Power dissipation at I hold Voltage proof
4.14 4.16
4.6
4.15
4.6 D
0 2 2A
2B
Resistance to soldering heat Robustness of terminations
Vibration Bump (or) shock
4.8.2 4.7
B.1 B.2 (or) B.3
D
D
0 3 Rapid change of temperature 4.10 D 10 0 4 Detail dimensions 4.3.3 ND 10 0 5 Cycle life 4.12 D 10 0 6 Trip endurance 4.13 D 10 0 7 Climatic sequence 4.11 D 10 0 8 Cold environmental electrical cycling 4.18 D 10 0 9 Thermal runaway 4.19 D 10
0 10 Solderability 4.8.1 D 10 0

62319-1  IEC:2005(E) – 17 – 3.5.5 Granting of qualification approval Qualification approval shall be granted when the procedures in accordance with 3.1.4 of IECQ 001002-3 have been completed satisfactorily. 3.5.6 Maintenance of qualification approval Qualification approval shall be maintained by regular demonstration of compliance with the requirements for quality conformance (see 3.5.7). 3.5.7 Quality conformance inspection 3.5.7.1 The blank detail specifications associated with this specification shall prescribe the test schedule for quality conformance inspection. This schedule shall also specify the grouping, sampling and periodicity for the lot-by-lot and periodic inspection (see Table 2 and Table 3). Sampling plans and inspection levels shall be selected from those given in IEC 60410. If required, more than one schedule may be specified. An inspection lot shall consist of thermistors of the same style. It should be representative of those extremes of resistance and switching temperature range produced during the inspection period. The sample for Groups C and D shall be collected over the last 13 weeks of the inspection procedure. 3.5.7.2 Assessment level The assessment level given in the blank detail specification shall be in accordance with Table 2 and Table 3. Table 2 – Quality conformance inspection for lot-by-lot inspection Inspection
Assessment level
subgroupd
EZ
ILa na ca
A0
100 %b
A1 A2 B1 B2 S-4 S-3 S-2 S-2 3) 3) 3) 3) 0 0 0 0
a IL is the inspection level.
n is the sample size
c is the permissible number of non-conforming items b 100 % testing shall be followed by re-inspection by sampling in order to monitor outgoing quality level by non-conforming items per million (10-6). The sampling level shall be established by the manufacturer. For the calculation of 10-6 values parametric failures shall be counted as a non-conforming item. In case one or more non-conforming items occur in a sample, this lot shall be rejected. c Number to be tested: sample size as directly allocated to the code letter for IL in Table IIA of IEC 60410 (single sampling plan for normal inspection) d The content of the inspection subgroups is described in Clause 2 of the relevant blank detail specification.

– 18 – 62319-1  IEC:2005(E) Table 3 – Quality conformance inspection for periodic testing Inspection
Assessment level
subgroup b
EZ
pa na ca
C1A C1B C1 C2A C2B C3 C4 D1 D2 D3 24 24 24 24 24 24 24 24 24 24 5 5 10 5 5 10 10 10 10 10 0 0 0 0 0 0 0 0 0 0
a p is the periodicity in months;
n is the sample size;
c is the permissible number of non-conforming items. b The content of the inspection subgroups is described in Clause 2 of the relevant blank detail specification.
3.6 Rework and Repair 3.6.1 Rework Rework, as defined in 4.1.4 of IECQ 001002-3, shall not be carried out if prohibited by the relevant specification. The relevant specification shall state if there is a restriction on the number of occasions that rework may take place on a specific component. All rework shall be carried out prior to the formation of the inspection lot offered for inspection to the requirements of the detail specification. Such rework procedures shall be fully described in the relevant documentation produced by the manufacturer and shall be carried out under the direct control of the designated management representative (DMR). Rework shall not be subcontracted. 3.6.2 Repair Thermistors which have been repaired as defined in IECQ 001002-3, shall not be released under the IECQ system. 3.7 Release for delivery Thermistors shall be released for delivery according to 3.2.6 and 4.3.2 of IECQ 001002-3, after the Quality Conformance Inspection prescribed in the detail specification has been carried out. 3.7.1 Release for delivery under qualification approval before the completion of Group B tests When the conditions of IEC 60410 for changing to reduced inspection have been satisfied for all Group B tests, the manufacturer is permitted to release components before the completion of such tests.

62319-1  IEC:2005(E) – 19 – 3.8 Certified test records of released lots When certified test records are requested by a purchaser, they shall be specified in the detail specification. 3.9 Delayed delivery Thermistors held for a period exceeding three years (unless otherwise specified in the relevant specification) following the release of the lot shall, before delivery, be re-examined as specified in the relevant specification. The re-examination procedure adopted by the manufacturer’s DMR shall by approved by the NSI. Once a lot has been satisfactorily re-inspected, its quality is re-assured for the specified period. 3.10 Alternative test methods See 3.2.3.7 of IECQ 001002-3 with the following details: • in case of dispute, for referee and reference purposes, only the specified methods shall be used. 3.11 Manufacture outside the geographical limits of IECQ NSIs A manufacturer may have his approval extended to cover part or complete manufacture of thermistors in a factory of his company located in a country which does not have a NSI for the technical area concerned, whether this country is a IECQ member country or not, provided that the requirements of 2.5.1.3 of IECQ 001002-3 are met. 3.12 Unchecked parameters Only those parameters of a component which have been specified in a detail specification and which were subject to testing shall be assumed to be within the specified limits. It cannot be assumed that any unspecified parameter will remain unchanged from one component to another. Should for any reason it be necessary for further parameters to be controlled, then a new, more extensive specification shall be used. The additional test method(s) shall be fully described and appropriate limits, sampling plans and inspection levels specified. 4 Test and measurement procedures This clause contains test and measurement procedures applicable to polymeric PTC thermistors. 4.1 Standard conditions for testing Unless otherwise specified, all tests shall be carried out under standard atmospheric conditions for testing as specified in IEC 60068-1. The thermistors shall attain thermal equilibrium before results are recorded. The ambient temperature during the measurements shall be stated in the test report.

– 20 – 62319-1  IEC:2005(E) During measurements, the thermistor shall not be exposed to draughts, direct sun rays or other influences likely to cause error. The total error of measurement from power dissipation, temperature tolerance and the tolerance of the measuring equipment shall not exceed 10 % of the tolerance in the detail specification. The test shall be carried out in the prescribed order. 4.2 Drying and recovery 4.2.1 Drying Where drying is called for in the specification, the thermistor shall be conditioned before measurement is made, using Procedure 1 or Procedure 2 as called for in the detail specification. Procedure 1 For (24 ± 4) h in an oven at a temperature of (55 ± 2) °C and relative humidity not exceeding 20 %. Procedure 2 For (36 ± 4) h in an oven at (100 ± 5) °C The thermistor shall then be allowed to cool in a desiccator using a suitable desiccant such as activated alumina or silica gel, and shall be kept therein from the time of the removal from the oven to the beginning of the specified tests. 4.2.2 Recovery Where recovery is required, the thermistor shall be stored at standard atmospheric conditions for testing for 1 h to 2 h. 4.3 Visual inspection and check of dimensions 4.3.1 Visual examination The condition, workmanship and finish shall be satisfactory as determined by visual examination. 4.3.2 Marking Marking shall be legible as determined by visual examination. 4.3.3 Dimensions (detail) All dimensions prescribed in the detail specification shall be checked and they shall comply with the values prescribed. Where applicable, measurements shall be made in accordance with IEC 60294.

62319-1  IEC:2005(E) – 21 – 4.4 Zero-power resistance 4.4.1 The zero power resistance shall be measured at the temperature given in the detail specification
...