Feeds

Apple files chip block stack patent

Beyond the A4

Securing Web Applications Made Simple and Scalable

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. ®

Application security programs and practises

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
For Lenovo US, 8-inch Windows tablets are DEAD – long live 8-inch Windows tablets
Reports it's killing off smaller slabs are greatly exaggerated
Microsoft unsheathes cheap Android-killer: Behold, the Lumia 530
Say it with us: I'm King of the Landfill-ill-ill-ill
Cheer up, Nokia fans. It can start making mobes again in 18 months
The real winner of the Nokia sale is *drumroll* ... Nokia
Seventh-gen SPARC silicon will accelerate Oracle databases
Uncle Larry's mutually-optimised stack to become clearer in August
EU dons gloves, pokes Google's deals with Android mobe makers
El Reg cops a squint at investigatory letters
Apple orders huge MOUNTAIN of 80 MILLION 'Air' iPhone 6s
Bigger, harder trouser bulges foretold for fanbois
prev story

Whitepapers

Top three mobile application threats
Prevent sensitive data leakage over insecure channels or stolen mobile devices.
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.
Top 8 considerations to enable and simplify mobility
In this whitepaper learn how to successfully add mobile capabilities simply and cost effectively.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.