Floor Life and Baking: What Happens After the Moisture Barrier Bag Is Opened

Floor life starts the moment the moisture barrier bag is opened and runs until reflow — or until the parts must be baked. Three mistakes cause most of the damage: treating a dry cabinet as a moisture barrier bag, resealing by folding or taping, and reusing exhausted desiccant.

The clock

Floor life is the maximum time a component may sit in ambient conditions after removal from its moisture barrier bag before reflow must occur, or baking becomes mandatory. It is defined against a stated ambient — commonly 30 °C / 60% RH in the standard's tables — and it depends on the device's MSL.

For MSL 6 devices the position is simpler and stricter: bake is mandatory before use, and after baking the part must be reflowed within the time limit stated on the label.

Mistake 1 — treating a dry cabinet as a moisture barrier bag

The standard addresses dry storage directly, and the distinction is explicit: dry cabinets should not be considered a moisture barrier bag. Storage time in a dry cabinet is limited to a maximum period set out in the standard's own table, and if that limit is exceeded, the parts should be baked.

So a dry cabinet buys time. It does not remove the requirement, and it does not reset the clock the way a proper reseal does.

Mistake 2 — resealing with tape or a fold

Resealing in a moisture barrier bag with fresh desiccant and a humidity indicator card is acceptable for short-term storage and for moving parts between locations. The conditions are specific:

• The bag must be properly heat-sealed — not folded, not taped.
• The desiccant must be fresh or regenerated, and conforming to the specification the pack calls for.
• Exhausted desiccant provides no protection. A used bag with a spent sachet looks compliant and performs nothing.

That third point is the one that turns into a quality claim, because a spent sachet and a live one are visually identical.

Mistake 3 — assuming the shelf life does not reset

The useful counterpart: if parts are dried and sealed in a moisture barrier bag with fresh desiccant, the shelf life is reset. Failures are recoverable — but only with a real seal and live desiccant.

The correct sequence

What to put in a handling procedure

Sources and Standards

• Published text of IPC/JEDEC J-STD-033 — dry cabinets not an MBB; maximum dry-storage period and the bake requirement; resealing conditions; shelf life reset when parts are dried and sealed in an MBB with fresh desiccant; mandatory bake for level 6 with reflow within the label time limit.
• Floor life definition and ambient conditions from published industry guidance summarising the standard.
• The pack itself is specified in J-STD-033 dry packing; the checklist form is in the dry-pack checklist.