I was looking at the prices of Flash memory cards and found them to be quite inexpensive. I then looked at the price difference for the iPhone 16, 32 and 64 GB versions.
This got me thinking - I read somewhere that 64 GB versions use 'double density NAND Flash.' Does this mean that there is more stacked in the card which is of the same size as the 16 GB card say?
Does it really take a lot more engineering to include memory which is larger in a phone?
Yes, a flash module is a bunch of tiny capacitors filled with silicon oxide (glass) or a similar variation.
capacitor has a leakage current (electricity is dissipated slowly though the oxide)
To fix this the oxide (known as a dielectric) needs to have a high dielectric value.
but when you shrink down the channel length (to get a large capacity) you need to come up with new materials and new ways of of engineering it so you can retain the data for a long period of time
There are other issues that get in the way as well. that is just one. you often times need new machines to make the channel length smaller, new facilities even with better air filtering abilities.
So to wrap it up, it is not just a matter of adding more bytes to the chip, there is a lot that must be done to make it happen.
answered Sep 25 '12 at 16:22