To mitigate issues of devices—ranging from personal electronics, including computers and cell phones, to industrial automation systems—getting damaged due to humidity, industry standards require that SMDs, PCBs, and other sensitive products be transported and stored in moisture protective packaging known as dry packs. These “dry packs” are composed of a moisture-barrier bag, a desiccant, and a humidity indicator card (HIC).
Clariant, a provider of specialty chemical systems, creates dessicants and HICs to meet these requirements. The company’s HICs are designed to signify the presence—or absence—of moisture via moisture-sensitive spots that change color when moisture exposure occurs. Traditionally, the moisture-reactive material used in these indicator spots is a halogen compound, such as cobalt dibromide (CoBr2), copper dichloride (CuCl2) or copper dibromide (CuBr2).
Conventional Type 1 HICs are “reversible” and only reflect current levels of humidity. In dry packs with improper, defective, or damaged seals, exposure to high humidity (>60%) can occur, but it may not be reflected on a Type 1 reversible card. A Type 1 reversible HIC would register humidity exposure via a color change from blue (dry conditions) to pink (wet conditions).
However, once returned to a low humidity environment, the reversible spot would change back to blue, indicating the current lower humidity level. This Type 1 HIC would show no evidence of the earlier high humidity exposure which could indicate potential damage to the PCBs or SMDs.
In response to limitations of Type 1 reversible HICs, Clariant has developed the Humitector Type 2 HIC, a “non-reversible” halogen and cobalt dichloride free card. This Type 2 HIC has a non-reversible 60% humidity indicator designed to remain blue after moisture exposure. When the 60% RH spot is exposed to humidity for a prolonged period of time the blue color is intended to migrate beyond the indicator circle to provide a permanent visual signal of humidity exposure.
The company has also eliminated cobalt dibromide (CoBr2) in the 60% RH spot, so that the Humitector Type 2 HIC can offer an improved environmental profile. As such, the Humitector Type 2 HIC is made to represent an overall halogen reduction of more than 50% compared to its HIC Type 1 predecessor. Halogens have become of particular concern due to the rise of indiscriminate disposal and unregulated recycling of electronic devices in many parts of the world.
This HIC products passes the BS EN 14582, a widely accepted halogen test method, meets Joint Electron Device Engineering Council (IPC/JEDEC) standards and applicable Registration, Evaluation, Authorisation, and Restriction of Chemicals (REACH) regulations, the according to the company.
