Humidity indicator card

Rear Admiral Welford C. Blinn, at that time the Commander of the USS Pope, became concerned about the poor condition of the weapons and ammunition arriving in the Pacific Theater.

High humidity in the South Pacific, coupled with poor packaging methods, was causing corrosion and moisture damage.

For 50 years, industrial and military applications for color change humidity indicators were the primary market for these products.

Adherence to proper storage and handling methods immediately reduced the number of failures in the semiconductors, but over the years it became apparent that even humidity levels under 10% were detrimental to the devices.

Once again, the Joint Electron Device Engineering Council (JEDEC), now the standards body for semiconductor packaging, went to the descendants of R. Admiral Blinn to determine the feasibility of making a 5% color change humidity indicator.

In 1998, the European Community (EC) issued a directive which classifies items containing cobalt(II) chloride of 0.01 to 1% w/w as T (Toxic), with the corresponding R phrase of R49 (may cause cancer if inhaled).

[citation needed] The only effect the EC directive has on a humidity indicator card that contains cobalt(II) chloride is setting labeling requirement thresholds.

HICs are used to ensure that the humidity within dry packed barrier bags remains at safe levels for surface mount devices.

The methods outlined in the standard are prescribed by JEDEC and IPC to avoid damage—like cracks and delamination—from moisture absorption and exposure to solder reflow temperatures that can result in yield and reliability degradation.

If the card indicates high levels of humidity, users know to check their products for possible damage or modify their packaging regimen accordingly.