IEC 60749-30-2020 pdf free download

IEC 60749-30-2020 pdf free download.Semiconductor devices — Mechanical and climatic test methods — Part 30: Preconditioning of non-hermetic surface mount devices prior to reliability testing
Dispositifs a semiconducteurs — Méthodes d’essais mécaniques et climatiques — Partie 30: Preconditionnement des composants pour montage en surface non hermétiques avant les essais de fiabilité.
Not sooner than 15 mm and not longer than 4 h after removal from the temperature/humidity chamber, submit the devices to three cycles of the appropriate reflow conditions in accordance with lEG 60749-20. All temperatures refer to the top surface of the package. The sample parts shall be cooled sufficiently for at least 5 mm (preferably back to room temperature) between reflow cycles so that the reflow temperatures/times of the samples are not affected on the subsequent reflow cycles.
Reflow practices shall be sufficient to ensure that all sample parts, in each reflow cycle, will meet the appropriate reflow profile requirements of IEC 60749-20. SMDs intended for use in a “Pb-free” assembly process shall be evaluated using the “Pb-free” reflow temperature whether or not the SMD is Pb-free. If parts are reflowed in other than the normal assembly reflow orientation (i.e. live-bug/dead-bug) the damage response shall be correlated.
The reflow oven shall be loaded with the same configuration or be verified to have an equivalent thermal load when running preconditioning as was used to develop the reflow profile. The reflow profiles in IEC 60749-20 are only for classification and preconditioning and are not intended to specify board assembly profiles. Actual board assembly profiles shall be developed based on specific process needs and board designs and shall not exceed the parameters in IEC 60749-20.
If the timing between removal from the temperature/humidity chamber and initial reflow cannot be met then the parts shall be rebaked and resoaked in accordance with 6.4 and 6.5.
NOTE I The three reflow cycles represent the following:
• Cycle 1 — the first pass of a double-sided, double-pass (DSDP) assembly reflow process.
• Cycle 2 — the second pass of a DSDP assembly reflow process.
• Cycle 3 — rework of a near neighbor on the assembly where the SMD being classified experiences reflow-like temperatures.
NOTE 2 For SMDs that cannot be subjected to three reflows, only the number of reflows for which the SMD is classified is performed.IEC 60749-30-2020 pdf free download.