Feeds

Apple files chip block stack patent

Beyond the A4

Build a business case: developing custom apps

Apple has filed a patent application that supports the stacked-component design of its A4 chip used in the iPad and iPhone 4, and points to further future integration of multiple system components on the same die.

The filing, "Systems and methods for providing a system-on-a-substrate," describes methods for reducing the size of a device by combining — in the words of the application — "all of the components of the system on the same microchip."

And by "all," the application is rather inclusive: "The components of a system can include one or more of a processor, memory (e.g., RAM, SDRAM, DDR RAM, or ROM), CODEC circuitry, Input/Output ("I/O") circuitry, communication circuitry, accelerometers, capacitors, inductors, or any other suitable components."

Apple's A4 chip isn't quite as all-embracing. As the teardown junkies and part-suppliers at iFixIt showed when they partnered with Chipworks to deconstruct Apple's ARM-based part, the A4 stacks two layers of RAM above the processor die in the A4's package:

iFixIt and Chipworks deconstruction of Apple's A4 chip

The A4, cut in half: that grey slab on the bottom is the ARM chip, with two RAM slices on top (source: iFixIt)

This technique is essentially what Apple describes in the first, and simplest, iteration in its patent filing:

Apple 'system-on-substrate' patent-filing illustration

Simple: memory on top of a processor on top of a PCB, with more memory underneath

Apple's patent filing goes further, though. It foresees a time when far more components can be placed on the same die: hence the term "system-on-a-substrate."

In one "embodiment" — patentese for "example" — a substrate can combine multiple components such as any or all from those listed above. That substrate, packaged up as a single chip, can then sit on a flexible printed circuit board ("flex"), which can extend beyond the package to support other components:

Apple 'system-on-substrate' patent-filing illustration

Now we're getting somewhere: multiple components on the same substrate

The filing also envisions embodiments in which the substrate can support both a flex layer upon which, say, memory is installed, along with a series of other components combined into their own package:

Apple 'system-on-substrate' patent-filing illustration

Various embodiments — such as this one — mix and match components, flex, and substrate

The goal off all this mixing and matching and cramming and combining is component shrinkage. According to the filing, a printed circuit board may require traces that are 60 micrometers in width and spaced 60 micrometers apart, while a substrate can get away with 15/15 — that would allow, according to the filing, a four-layer, 0.2 millimeter–thick substrate to replace a six-layer, 0.5 millimeter–thick PCB.

In addition to a substrate's straightforward size advantages, the ability to stack components on top of one another — as is done in the A4 — provides another opportunity to shrink a part's footprint.

In handheld, pocketable devices, size does matter — and this patent filing describes a series of ways that Apple could pack more functions into smaller spaces. Whether such a straightforward idea as component-stacking and substrate-packing is patentable, however, remains to be seen. ®

Build a business case: developing custom apps

More from The Register

next story
iPad? More like iFAD: We reveal why Apple fell into IBM's arms
But never fear fanbois, you're still lapping up iPhones, Macs
Sonos AXES support for Apple's iOS4 and 5
Want to use your iThing? You can't - it's too old
You didn't get the MeMO? Asus Pad 7 Android tab is ... not bad
Really, er, stands out among cheapie 7-inchers
Apple winks at parents: C'mon, get your kid a tweaked Macbook Pro
Cheapest models given new processors, more RAM
4K video on terrestrial TV? Not if the WRC shares frequencies to mobiles
Have your say with Ofcom now, before Freeview becomes Feeview
Leaked Windows Phone 8.1 Update specs tease details of Nokia's next mobes
New screen sizes, dual SIMs, voice over LTE, and more
YES, iPhones ARE getting slower with each new release of iOS
Old hardware doesn't get any faster with new software
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Backing up Big Data
Solving backup challenges and “protect everything from everywhere,” as we move into the era of big data management and the adoption of BYOD.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.