Face-to-face for 20MByte chip card
Infineon Technologies is using an innovative "chip-sandwich" technique that involves face-to-face interconnection to design chip card ICs for use in mobile communications. One aim is to offer more than 100 times the memory capacity of today's chip cards, while just doubling the chip's area. The new chip card ICs will not only deliver significant performance boosts, the company says, but will enable new applications for mobile phones and smart cards.
Infineon claims the world's first chip card security controller using the innovative face-to-face technology, offering 1MByte of memory capacity, manufactured in a 130nm process technology. The new SLE88CFX1M00P belongs to the 88 family of 32-bit chip card controllers. It is expected that the first application of the 1MByte security controller will be in SIM cards (GSM, UMTS), where the demand for higher memory capacities is the greatest, with network providers supplying further multimedia services and high data rate transfer services. Infineon believes that it can build an ISO-compliant chip card microcontroller offering up to 20MByte of memory, based on demand, which is expected to be available in the second half of 2006.
"Existing robustness constraints of ISO specifications limit chip card ICs' area to a maximum of 25mm2, with restrictions in functionality enhancements and price-competitiveness, as expensive process shrink technologies have to be deployed," comments Dr Juergen Kuttruff, vice president and general manager at Infineon's Security unit of the Secure Mobile Solutions business group.
Without extra-wirebonding, the face-to-face chips are mechanically and electrically interconnected via the hundreds of tiny contact pads of the chips, resulting in higher performance and memory capacity on the same chip area, while at the same time fitting into a standard chip card specific package.
The approach allows stacking of chips with diverse interfaces, such as USB (Universal Serial Bus), SPI (Serial Peripheral Interface) bus or ISO14443 interfaces, as well as ASICs and field-programmable gate array (FPGA) solutions and chips manufactured using different processes and technologies, such as EEPROM, Flash, NROM (Nitrided Read Only Memory), etc.
Samples of the SLE88CFX1M00P will be available in spring 2005 with volume production starting in H2 2005. Equipment companies EV Group and Datacon have recently applied face-to-face technology to create a chip to wafer bonding technology (Bulletin 556, October 15, 2004).
