DD IEC PAS 62435:2005 pdf download Electronic components — Long-duration storage of electronic components — Guidance for implementation
Scope
This Publicly Available Specification (PAS) is, first of all, a practical quide to methods of longduration storage (more than five years) which summarizes the existing practices in the industry.
Unless otherwise specified, the approach, as well as the methods presented, apply to all familiesof electronic components, such as
passive components， including quartz crystals, connectors and relays. However.components with “manufacturer’s” specifications showing an expiry date or specific storageconditions are excluded from this document (for example, primary cells, storage cells, etc.);
encapsulated or non-ncapsulated active components of a silicon (S] or gallium arsenide[GaAs] technology;
micro-electronic assemblies
Normative references
The following referenced documents are indispensable for the application of this document. Fordated references, only the edition cited applies. For undated references, the latest edition of thereferenced document (including any amendments) applies.
EC 60068-2-17:1994，Basic environmental test procedures – Part 2: Tests – Test Q: Sealing
EC 60068-2-20:1979，Environmental testing – Part 2: Tests – Test T: Soldering
IEC 60410:1973,Sampling plans and procedures for inspection by attributes
EC 61340-5-1:1998,Electrostatics – Part 5-1: Protection of electronic devices from electrostaticphenomena-General requirements
EC 61340-5-2:1999, Electrostatics – Part 5-2: Protection of electronic devices from electrostaticphenomena-User guide
IEC 61945, Integrated circuits – Manufacturing line approval – Methodology for technology andfailure analysis
IEC 62380: Reliability data handbook – Universal model for reliability prediction of electronicscomponents，PCBs and equipment
EN 190 000:1995,Generic specification – Integrated monolithic circuits
Storage decision criteria
Any creation of an electronic component inventory should be carried out
on the one hand, after having compared with the following additional solutions:modification to the printed board by adding a “backpack” macro-component
development of a specific ASIC;
production relaunched at a manufacturer specialized in the resumption ofobsolete technological processes and components;complete revision of the board or the equipment:
on the other hand, by taking into account the following aspects.
Advantages3.1
Technical simplicity – Rapidity3.1.1
When the various steps of the storage process are finalized and validated, the creation of astock is a simpler, faster and technically less hazardous solution than developing or modifyinaelectronic boards.
Storage can also be a temporary solution enabling equipment maintenance during modificationor development of electronic boards.
3.1.2Solution durability
Any equipment changes based on the use of new electronic components will be facedeventually, with the obsolescence of these new components. Storage can resolve obsolescenceproblems until the end of the operating life of the equipment.
3.1.3Preventive storage
Preventive storage (i.e., before the component becomes obsolete) presents several additionaadvantages compared with remedial storage (i.e., when the component has already becomeobsolete).for example.when
the component price has not become prohibitive as in the case of specific obsoletecomponents which have become very rare;
the quality level is ensured if the component can be purchased direct from the manufactureror approved distributor. When a component has been obsolete for a long time, it can only befound at specialists in purchasing, storage and resale of obsolete components (“brokers”). lnthis case,no component reliability guarantee will apply.
3.2Hazards – Drawbacks
3.21Generic aging hazard
Stock dimensioning is based on the assumption of a constant component failure rate. Theproblem of generic aging of the components (“bath-tub curve”) cannot be easily taken intoaccount and quantified. However, the existing electronic components seem to have extremely
PAS 62435:2005 pdf download
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