IEC 62435-8-2020 pdf free.Electronic components – Long-term storage of electronic semiconductor devices – Part 8: Passive electronic devices.
4.1 Overview of passive components
Passive components are not able to control current where the instantaneous power cannot be negative therefore there is no power gain before the application of electric energy. Common examples of passives are resistors, capacitors, inductors, transformers and diodes of all types. Often electromechanical relays, quartz crystals and fuses are also to be considered passive components for the purpose of long-term storage requirements. Passive components are made using a wide range of technologies, materials and manufacturing processes.
Passive components are surface mounted to electronic packages, modules and boards as either discrete components or packaged components that vary in size, typically larger than 1 mm in the smallest dimension. Passive miniaturization has led to packaged passives. Passives are also integrated or embedded into other packaged components, modules and boards.
Passive components can experience many of the same failure modes as other components and the storage program should consider the end use and failure mechanisms related to the function of the component. An example list below may be used as a basis for consideration in storage related risk assessments.
4.2 Failure mechanisms
4.2.1 Occurrence of failure and driving force
Failures during long-term storage should be mitigated by control of the stimuli driving given failure modes of interest as defined by a failure modes and effects analysis (FMEA). Storage related failures are often detected as modes of non-operation, visual quality or other nonconformance. The modes of failure during storage are typically related to a failure mechanism that is driven by a physical stimuli or condition. Successful long-term storage is accomplished by controlling the failure mechanism stimuli as identified using a failure modes and effect analysis based on information from technology development and testing. Example failure stimuli are given in Table 1. Additional examples of deterioration mechanisms are found in lEG 62435-2. Successful long-term storage is accomplished by mitigating failures through control of the stimuli or driving force.
4.2.2 Storage environment and mitigation for stimuli to prevent failure
Mitigation of failures during and after long-term storage occurs by directly controlling or limiting the stimulus for failure by a number of means. Common requirements for sustained long- term storage are given in Table 2. Knowledge and control of the storage environment is of primary importance to identify the risk of failure occurrence and to control or eliminate failure stimuli during storage. Examples of the storage environment are contained in IEC 62435-4. Other storage environment parameters related to long-term storage that may be important for products or devices with certain sensitivities are presented in Annex A. It is the responsibility of the end customer to maintain the storage environment as well as to ensure that terms and conditions are in place successful long-term storage at the time of product purchase.
The full component thermal and environmental chain should be considered in planning reliability characterization evaluation and for estimation of reliability after storage and added to the use reliability estimates.IEC 62435-8 pdf download.