Scientists at Infineon Technologies have developed "SOLID" packages, a technique to solder different types of chips together to form a "sandwich" chip system.
The technique uses standard chip-making and packaging machinery.
For its first sample, Infineon produced the upper and lower modules of the sandwich chips. Upper and lower sides were coated with a very thin layer of copper to which a 3-µm thick solder was applied. Both chips were soldered together at a temperature of 270°C and 3-bar pressure to create a permanent bond. To produce a chip no higher than usual, Infineon used thinned silicon wafers. A compound plastic material was used for the outer layer of the pac-kages.
A SOLID product can achieve clock rates of up to 200 GHz (100 times faster than today’s fastest desktop PC processors) and support more communication lines between the chips in the package.
In comparison, a smartcard controller - the current controller - has only a limited memory capacity of 32-Kbytes while Infineon's prototype has 160-Kbytes of non-volatile memory. The technology promises both to speed up chip performance,
and to help reduce the price of current chip solutions by up to 30 percent.