Hitachi Ltd yesterday said it has developed the smallest and thinnest RFID chip to date, so small that it could be used an intelligent watermark.
The Japanese electronics giant presented details of its 0.15mm by 0.15mm, 7.5 micron-thick chip at the International Solid-State Circuits Conference in San Francisco.
The 7.5-micron chip substrate would be thinner than paper, which typically measures 80 to 100 microns thick.
The chip is a smaller version of the 0.4 x 0.4 mm Mu-chip, developed in September 2003. Both have the RFID antenna integrated into the chip.
The distance between each circuit element was reduced in the latest prototype by using SOI technology, which has an insulating layer in the substrate, instead of the silicon-only substrate currently being used.
The tiny chip’s data is written during the fabrication process using read-only memory. It is impossible to rewrite the data and thus provides a high level of security, Hitachi said.
The first Mu-chip was used in the admission tickets for the 2005 World Exposition in Japan. The latest chip, which is nearly one-fifteenth the size of its predecessor, is expected to be several years from production.