Any stacked memory dies would have to be compatible with the new package, but we did not hear about adjustments by them.
For Xilinx, FPGA dies were side by side on same interposer, but all the dies were made at tsmc, as well as interposer.
I don't know why Apple and tsmc would take such risk so soon. I think the 28 nm yield is hard enough already, and could be the real issue.
Not sure if package need major change, yes some internal changes are required.
Regarding risk, probably its worth taking that risk since stcked dioe give benifit of speed and power which will give them market edge. Even if they fail for first time atleast they will be ahead of market by one step to implement this.
I don't think Apple should be worried. They are still relying on Samsung, just using TSMC as second source to keep pressure on Samsung for low price. Pretty standard technique almost every big fabless company uses this trick.
@p_g- But can Apple continue to rely on Samsung for producing its processors while at the same time engaging in a legal battle with the South Korean firm over the Galaxy Tab? Seems like something's gotta give.
@dylan; I agree with you. Samsung has good revenue in fab coming from Apple. But key thing is if Apple withdrew then can Samsung keep its fab busy? I don't think Samsung fab want to give up just for Galaxy at the same time Apple is preparing for worst case too.
This may be another good example of how Apple respect its designers. Design team of A6 may need more time to optimize product and specification and they may need one or more run. It is is not good practice to fix product launch date before design team agrees to design progress. One wrong example from Apple was iPhone4 Antenna. They should have given more time to RF/Microwave engineers for testing and refinement.
3-d stack memory module integrated on an interposer w/ a CPU on the other side would definitely help both power consumption and bus throughput( shorter lengths ) in handheld systems.
Apple often takes leadership at the system integration level but is not known for sticking its neck out to the bleeding edge of component ( e,g. die ) technology. Indulging in 3-d stack memory ( wide I/O bus ) would require getting involved in Semiconductor Physics ? Does Apple have the manpower to handle these problems yet ?
What would be a Killer App for Apple to justify it ? TV in a Smart Phone ?
3-d stacking has issues. First heat dissipation ( so initial applications will not include the CPU ), then stress ( efect of flexing in through silicon vias affecting device performance, hence requiring wide keep - outs / die real estate ).
Perhaps right now Apple is just testing the waters and getting the Suppliers ready. Application in real systems will have to wait for 2 - 3 years.
Is TSMC the only foundry capable for the 28nm and 3-D packaging together? If yes, Apple doesn't have to worry anything about. They just need some more marketing work to extend the lifetime of iPad2. I still believe Apple can dominate the tablet market by next Q1. So, if TSMC can fix the issue in time while it leaves enough time for Apple to refine the product, the new iPad may be more sexy! BTW, it is not too long to wait from iPad2 ato iPad3 (at least I don't think so).