Where will it all stop...Intel has released a new package for stacking memory chips that will let manufacturers put more memory into mobile phones without increasing the size of the handsets. The new package, called the Ultra-Thin Stacked Chip Scale Package, lets manufacturers stack up to five memory chips on top of each other, said Scott Dunagan, Intel's product marketing manager. Currently, Intel sells memory packages that can stack up to four chips on top of each other. Most mobile phone makers use packaging that holds only one or two chips. With the new package, mobile phone makers will be able to put 512 megabits of flash memory - along with other memory chips - into phones this year, and one gigabit next year without increasing the surface area needed on the board. Other flash manufacturers are working on similar packaging techniques. "The whole mindset is, how do we put more and more into less and less space," Dunagan said, adding that 20 to 25 per cent Intel's revenue is from stacked memory and it's continuing to grow. Squeezing more memory into tight spaces is crucial the success of the flash-memory industry. Demand for flash memory, used to store data and code in mobile phones and other consumer devices, is growing dramatically. The amount of flash in some phones has more than doubled within a year. Shrinking the size of chips, however, is getting harder. Clever packaging effectively allows semiconductor manufacturers to accommodate the demand for memory without putting too much stress on their manufacturing plants. Intel is also working to reduce the height of the stack. The five-chip stack, in fact, measures only one millimetre high, shorter than the 1.2-millimetre stack for two-chip packages. How does the company do it? Intel sands the back of the chips to reduce the average thickness from seven mils, or seven millionths of an inch, to three mils. The chips "are as thick as a sheet of paper", Dunagan said. "Ten together are as thick as a credit card." Future versions of the package also will come with a different base. Current models come with a foundation similar to printed circuit boards. In the future, this will be changed to a film.