IEC PAS 62435:2005

Electronic components - Long-duration storage of electronic components - Guidance for implementation

This PAS applies to the long-duration storage of electronic components. Although it has always existed to some extent, obsolescence of electronic components, and particularly integrated circuits, has become increasingly intense over the last few years. Indeed, with the existing technological boom, the commercial life of a component has become very short compared with the life of industrial equipment such as those encountered in the aeronautical field, the railway industry or the energy sector. The many solutions enabling obsolescence to be resolved are now identified. However, selecting one of these solutions must be preceded by a case-by-case technical and economic feasibility study, depending on whether storage is envisaged for field service or production, for example: - remedial storage as soon as components are no longer marketed - preventive storage anticipating declaration of obsolescence Taking into account the expected life of some installations, sometimes covering several decades, the qualification times, and the unavailability costs, which can also be very high, the solution to be adopted to resolve obsolescence must often be rapidly implemented. This is why the solution retained in most cases consists in systematically storing components which are in the process of becoming obsolescent. The technical risks of this solution are, a priori, fairly low. However, it requires the perfect mastery of the implemented process, and especially of the storage environment, although this mastery becomes critical when it comes to long-term storage. All handling, protection, storage and test operations must be performed according to the state of the art.

General Information

• Status: Replaced
• Publication Date: 25-Sep-2005
• ICS: 31.020 - Electronic components in general
• Technical Committee: TC 47 - Semiconductor devices
• Drafting Committee: WG 3 - TC 47/WG 3
• Current Stage: DELPUB - Deleted Publication
• Start Date: 06-Feb-2017
• Completion Date: 20-Jan-2017

Relations

• Replaced By: IEC 62435-1:2017 - Electronic components - Long-term storage of electronic semiconductor devices - Part 1: General
• Effective Date: 05-Sep-2023

Standards Content (Sample)

PUBLICLY
IEC
AVAILABLE
PAS 62435
SPECIFICATION
First edition
Pre-Standard
2005-09
Electronic components –
Long-duration storage of electronic
components –
Guidance for implementation
Reference number
IEC/PAS 62435:2005(E)
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PUBLICLY
IEC
AVAILABLE
PAS 62435
SPECIFICATION
First edition
Pre-Standard
2005-09
Electronic components –
Long-duration storage of electronic
components –
Guidance for implementation
 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, Switzerland
Telephone: [phone] Telefax: [phone] E-mail: [e-mail] Web: www.iec.ch
PRICE CODE
Commission Electrotechnique Internationale
U
International Electrotechnical Commission
Международная Электротехническая Комиссия
For price, see current catalogue

– 2 – PAS 62435 © IEC:2005 (E)

CONTENTS
FOREWORD.4
INTRODUCTION.5
1 Scope .6
2 Normative references .6
3 Storage decision criteria .6
3.1 Advantages .7
3.1.1 Technical simplicity – Rapidity.7
3.1.2 Solution durability .7
3.1.3 Preventive storage .7
3.2 Hazards – Drawbacks .7
3.2.1 Generic aging hazard.7
3.2.2 Poor stock dimensioning .7
3.2.3 Incorrect control of reliability during storage .8
3.2.4 Freezing equipment functionalities .8
3.3 Storage cost .8
3.4 Decision criteria.8
4 Purchasing – Procurement.9
4.1 List of components .9
4.2 Quantity of components to be stored .9
4.2.1 Production stock .9
4.2.2 Field service stock .9
4.3 When is it worth keeping in stock? .10
4.4 Procurement recommendations.10
5 Technical validation of the components.10
5.1 Purpose .10
5.2 Relevant field .10
5.3 Test selection criteria .11
5.4 Measurements and tests.11
5.4.1 Sampling .11
5.4.2 Visual examination, sealing, solderability.11
5.4.3 Compliance with the electrical specifications .12
5.4.4 Assessment of the supplied batch reliability.13
5.4.5 Manufacturing control check (technological analysis) .15
5.5 Sanction.15
6 Conditioning and storage .15
6.1 Type of environment .15
6.2 Elementary storage unit .16
6.3 Stock management .16
6.4 Redundancy .16
6.5 Identification – Traceability .16
6.6 Initial packaging .16
6.7 Stabilization bake .17
6.8 Storage conditions.17
6.8.1 Storage area.17
6.8.2 Temperature .17

PAS 62435 © IEC:2005 (E) – 3 –

6.8.3 Temperature variations .17
6.8.4 Relative humidity – Chemical attacks – Contamination.17
6.8.5 Pressure.17
6.8.6 Electrostatic discharges .17
6.8.7 Vibration – Mechanical impacts .18
6.8.8 Electromagnetic field – Radiation .18
6.8.9 Light .18
6.9 Maintaining storage conditions.18
7 Periodic check of the components.18
7.1 Objectives .18
7.2 Periodicity .19
7.3 Tests during periodic check .19
8 Destocking .19
8.1 Precautions .19
8.1.1 Electrostatic discharges .19
8.1.2 Mechanical impacts.19
8.2 Inspection .19
9 Feedback .20

Annex A (informative) Example of a component list .21
Annex B (informative) Examples of periodic and/or destocking tests (1/3) .23
Annex C (informative) Parameters influencing the final price of the component storage .25
Annex D (informative) Parameters influencing the quantity of components to be stored .26
Annex E (normative) Failure mechanisms: Encapsulated and non-encapsulated active
components.27
Annex F (normative) Failure mechanisms: GaAs components.29

– 4 – PAS 62435 © IEC:2005 (E)

INTERNATIONAL ELECTROTECHNICAL COMMISSION
____________
ELECTRONIC COMPONENTS –
Long-duration storage of electronic components –
Guidance for implementation
FOREWORD
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IEC-PAS 62435 has been processed by IEC technical committee 47: Semiconductor devices.
The text of this PAS is bas
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