Moisture sensitivity and dry-pack records: what buyers should request

Published 20 October 2026. Manufacturer sources reviewed on 20 October 2026.

A full part number and reel quantity leave an important question unanswered for moisture-sensitive surface-mount components: what handling records accompany the offered material? Match the manufacturer’s moisture guidance to the exact orderable part, then distinguish an unopened dry pack from material that has been opened or repacked.

Identify the MSL for the exact part

Moisture sensitivity level, or MSL, concerns a package’s exposure before soldering. TI’s AN-2029 directs readers to the specific part number or datasheet for its MSL and describes a packing label carrying the level and permitted floor life. Keep the complete ordering code and the applicable manufacturer reference together.

ST’s AN2639 explains why this matters: moisture absorbed by a molded package can generate internal pressure during reflow and contribute to package cracking. The purchasing check is therefore tied to the particular package and its assembly requirements. A family name, carrier type or generic description such as “new original” does not supply that information.

Ask what is sealed, and what has been opened

TI’s handling note describes dry packing its moisture-sensitive components in a moisture-barrier bag with desiccant and a humidity indicator card. The carrier inside the bag and the moisture-protection packaging serve different purposes: identifying a reel or tray alone does not establish the dry-pack condition.

Ask for the offered material’s external label and packaging description, together with any existing handling records. A photograph can help identify a label or visible seal; it cannot reconstruct an undocumented exposure history. Do not ask a supplier to open an intact bag solely to photograph the humidity indicator card inside. Pass on any existing card record, or arrange its inspection as part of controlled receiving.

Record the complete manufacturer code, offered quantity and carrier.
Request the external moisture-sensitivity label and available lot or packing identifiers.
Ask whether the bag is unopened manufacturer packing, previously opened, or repacked; record unknown information explicitly.
Request available opening, exposure, storage and repacking records, rather than inferring them from a resealing date.

Keep floor life separate from a date code

TI describes floor life as the maximum permitted time between opening the moisture-barrier bag and final reflow. Its label-based handling guidance therefore requires more context than the manufacturing date or the date a seller resealed a bag. The relevant time and environmental limits must come from the applicable manufacturer information.

For a partial reel or previously opened lot, ask which exposure periods and storage conditions are documented. Keep the records linked to the material being offered. Resealing describes a packaging action; it is not, by itself, evidence that earlier exposure has been resolved or that a particular amount of floor life remains. Have the assembly or quality owner assess that history before release to production.

Resolve handling questions before the assembly handoff

ST’s TN1224 says exceeded exposure limits or an adverse humidity-indicator result can require drying before assembly. It also warns that repeated baking can affect solderability and that packing materials may not tolerate the baking temperature. A purchasing team should obtain the applicable instructions and records, then leave the disposition and process settings to the responsible assembly or quality team.

Include the required packing condition, available documentation and planned receiving checks in the RFQ. Ask the supplier to state any difference or missing record in the quotation. If the history is unknown, keep that uncertainty visible; do not convert “resealed” into an unqualified handling assurance. Wei Ya Hua’s BOM/RFQ service can be used to communicate these requirements alongside the exact part number, quantity and delivery request.

Does every IC require dry packing?

No. Check the exact device and package against its manufacturer’s MSL and packing requirements. Do not apply a moisture-sensitive component’s handling instructions to every IC.

Can a resealed bag confirm the remaining floor life?

Not on its own. Request the available exposure and storage history, record gaps, and have the responsible team assess the material against the applicable manufacturer instructions.

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