IEC 62435-3 pdf – Electronic components – Long-term storage of electronic semiconductor devices – Part 3: Data
The data archive is generally stored on any medium, which may include non-volatile memory, optical disk or storage in redundant array disk servers. It is important to ensure the environment for media storage is low risk for degradation, and accidental or random events that could destroy or corrupt the data. The value of the parts is highly dependent upon the data without which the company might cease to function. See Table A.1 for critical data storage considerations. The physical and cyber security of the archive store are not mentioned further here, but should be a main consideration when planning its location and access.
4.2 Data storage options From the early 1960s onwards, media for storing data other than paper, have historically evolved towards magnetic, optical and other forms of solid-state media. It is common practice to ensure redundancy of storage within storage servers, across physical sites and geographies. Redundant array storage enables periodic back-up copies and checks to ensure longevity. Some printed data is effectively undecipherable without computer assistance (such as bar codes or matrix marks). It is conceivable to store enough information in the optical markings to satisfy business requirements for traceability. Similarly, printed data may be recovered from paper or from the part using optical character recognition and associated software. Other legacy storage media, such as microfiche, can also be in use.
4.3 Paper data storage concerns Paper storage with the components being stored is subject to many hazards that can be mitigated with regular intervention. Data and information stored on paper can be corrupted by aging of ink, moisture or water exposure or simple loss of the physical paper record and/or it’s facsimile. It is recommended that the stored paper be acid free to minimize the risk of brittle degradation. The permanence of the printed mark on the archival paper should also be considered 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 relying on this media that are not instantly apparent. It shall be remembered that data to be archived shall be retrievable, otherwise the purpose of archiving is negated. Data redundancy can be achieved 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 “data storage”/”data warehouse” companies exist, and these are often used as a suitable secondary location backup and repository for critical or sensitive data. Data security should be considered in any storage scheme to avoid loss of data upon retrieval, storage itself or during decoding. Data security measures should be in place upon data recording on the systems used to generate and store the data. Data to be stored should be checked prior to storage. Finally, upon retrieval, data extraction equipment should employ data security measures in additional to ensuring that older data formats are not miscategorised as unsafe for security. All electronic data requires the use of a computer of some sort or another device to retrieve the data and possibly convert it into a human-readable or machine-useable format. Storage relies on four main precepts to recover this data:
the useable lifetime of the media itself;
the presence of the specific media-reading hardware;
the associated computer;
the interpreting and display/application software.
4.5 Data storage media failure mode considerations Storage media preservation or maintenance is as important as physical part storage to maintain the ability to re-establish provenance, design or test parameters or performance when the components are to be used. When considering magnetic media, such as tapes and disks, it is well known that the long-term storage of magnetic media has its own attendant issues, such as oxide-shedding and magnetic “punch-through” in as little as 5 years. Platter disks 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 to both the platter and read heads as soon as the platter is mounted. Network-attached storage and RAID schemes are used to mitigate the risks for the storage of drives.