The chipmaker said its new technology could either create 30% smaller packaged semiconductors, which means smaller phones, or increase the functionality possible in a phone while maintaining its current size.
The technology, which is still a couple of years’ from commercialization, could also be used to either make smaller or more powerful other mobile devices, including ultra-mobile or hand held computers.
Packaging and assembly technologies, while not sexy, play a large role in determine the size and performance of semiconductors and, in turn, the devices they power. Essentially, these technologies house and electrically interconnect a chip with outside circuitry, as well as providing physical protection of the chip. Packaging also can be key in dissipate heat generated by the chip, which is most useful for mobile applications.
But as the size of semiconductors shrink, it is becoming increasingly difficult to make smaller the package interconnects, which are the wire bonds and solder flip chip joints.
These physical dimensions of the packaging interconnects — the diameter of the gold wirebond and the flip chip solder joint – can not shrink much further without resulting in electrical shorts, said Beth Keser, RCP technology manager for Freescale. Alternative interconnections are needed.
Freescale has come up with an alternative it calls redistributed chip packaging, or RCP. The technology solves the problem by doing away with the need for wire bond or flip chip joints.
Instead, RCP uses technology similar to that in the top layers of metal on a semiconductor device to interconnect the packaging. And without flip chip or wirebond interconnect, RCP packaging accommodates a smaller chip by being able to shrink the physical dimensions of the interconnects in the package, Keser explained.
As chips get smaller, there’s no need to worry, for example, about, one, how much thinner wires can get before they lose their structural integrity or, two, the space that packaging substrates take up, she said.
RCP also more tightly integrates the various semiconductor devices and components used in a mobile device. By shrinking the size of the package assembly, electrical performance becomes more efficient, Keser said.
Also, the types of small form-factor devices that can be packaged into RCP can be interchangeable much in the same way a child’s building blocks can be changed, she added.
Keser said RCP would also be cheaper than existing technologies, thanks to the smaller package size and more cost-efficient manufacturing devices in RCP using semiconductor wafer processing tools. The amount of savings depends on device type, package size, and the number of interconnect layers required, she said.
Technically, Freescale’s new packaging might replace ball grid array, or BGA, which Freescale initially developed, and flip chip as the most commonly used packaging and assembly methods used today.
Austin, Texas-based Freescale said it plans to launch wireless products using RCP in 2008. Keser declined to speculate on exactly what types of products would first benefit from the technology.
