IEC 62435-3:2020 pdf free download – Electronic components -Long-term storage of electronic semiconductordevices
The data archive is generally stored on any medium, which may include non-volatile memory,optical disk or storage in redundant array disk servers. lt is important to ensure theenvironment for media storage is low risk for degradation,and accidental or random eventsthat could destroy or corrupt the data.The value of the parts is highly dependent upon thedata without which the company might cease to function. See Table A.1 for critical datastorage considerations. The physical and cyber security of the archive store are notmentioned further here,but should be a main consideration when planning its location andaccess.
4.2Data storage options
From the early 1960s onwards，media for storing data other than paper，have historicallyevolved towards magnetic, optical and other forms of solid-state media. it is common practiceto ensure redundancy of storage within storage servers，across physical sites andgeographies.Redundant array storage enables periodic back-up copies and checks to ensurelongevity. Some printed data is effectively undecipherable without computer assistance (suchas bar codes or’matrix marks). lt is conceivable to store enough information in the opticalmarkings to satisfy business requirements for traceability. Similarly，printed data may berecovered from paper or from the part using optical character recognition and associatedsoftware.Other legacy storage media,such as microfiche, can also be in use.
4.3Paper data storage concerns
Paper storage with the components being stored is subject to many hazards that can bemitigated with regular intervention. Data and information stored on paper can be corrupted byaging of ink,moisture or water exposure or simple loss of the physical paper record and/or it’sfacsimile. lt is recommended that the stored paper be acid free to minimize the risk of brittledegradation. The permanence of the printed mark on the archival paper should also beconsidered for long-term storage of paper with components.
4.4 Electronic data storage concerns
Careful selection of the electronic medium is required, as there are many hazards in relyingon this media that are not instantly apparent. It shall be remembered that data to be archivedshall be retrievable,otherwise the purpose of archiving is negated.Data redundancy can beachieved by redundant array of independent disks (RAID) at a local or remote network host.Similarly redundant optical storage may also be used for network storage. Third party “datastorage”/”data warehouse” companies exist,and these are often used as a suitable secondarylocation backup and repository for critical or sensitive data.
Data security should be considered in any storage scheme to avoid loss of data uponretrieval,storage itself or during decoding. Data security measures should be in place upondata recording on the systems used to generate and store the data.Data to be stored shouldbe checked prior to storage.Finally,upon retrieval, data extraction equipment should employdata security measures in additional to ensuring that older data formats are notmiscategorised as unsafe for security.
4.5Data storage media failure mode considerations
Storage media preservation or maintenance is as important as physical part storage tomaintain the ability to re-establish provenance,design or test parameters or performancewhen the components are to be used. When considering magnetic media,such as tapes anddisks， it is well known that the long-term storage of magnetic media has its own attendantissues, such as oxide-shedding and magnetic “punch-through” in as little as 5 years. Platterdisks are generally less susceptible，but “punch-through”can still occur,and head-dust,caused by deterioration of the ferric-oxide bonding agent, can lead to irreparable damage toboth the platter and read heads as soon as the platter is mounted. Network-attached storageand RAID schemes are used to mitigate the risks for the storage of drives.
Floppy disks are susceptible to mechanical and magnetic damage.Optical media,such as thecompact disk (CD) and the digital versatile disk (DVD), can also present problems.CD-Rs thatare written by the average computer have a distinct shelf life，and,dependent upon thestorage ambience can lose data in 18 months or less; the quality of the initial CD-R or CD-RWmedia is paramount.