Humidity Indicator Card - History

History

The need for an easily read humidity indicator that could not be damaged by vibration was identified during World War II. 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. A significant amount of ordinance was arriving in an unstable, and sometimes dangerous, condition. Following the end of the war R. Admiral Blinn was assigned to Washington, D.C. where he had the use of a research lab. There he developed the concept for the first color change humidity indicator, a simple “go/no-go” method of monitoring humidity.

In the late 1940s, Relative Humidity in the range of 30-35% was the concern because this is when corrosion can begin. For 50 years, industrial and military applications for color change humidity indicators were the primary market for these products. R. Admiral Blinn founded Humidial Corporation in 1948 Acquired by Süd-Chemie, Inc. in 1989 to commercialize humidity indicators.

In the mid-1980s descendants of R. Admiral Blinn began working with manufactures of semiconductors to identify and resolve the problem of “pop corning”. It was determined that the solder mounting of semiconductors, also known as devices, onto boards can cause "pop corning" of certain types of surface mount packages if they have been improperly stored or handled. This package delamination occurs as excessive moisture within the package expands as a result of the rapid thermal changes experienced during solder mount operations. As a result an industry wide standard for packaging of semiconductors was released in 1989. This standard, EIA 583, called for the use of humidity indicator card that would indicate as low as 10%. 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 April 1999, J-STD-033 was released with a 5, 10, 15% color change indicator card specified.

Humidity indicator cards are also present on many small electronic devices, ranging from cellular phones to laptop computers, for the purpose of alerting the manufacturer that the device has been exposed to high levels of moisture. In many cases this voids or changes the terms of warranty coverage for the device.