Feeds

Apple files chip block stack patent

Beyond the A4

The Power of One Brief: Top reasons to choose HP BladeSystem

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. ®

Using blade systems to cut costs and sharpen efficiencies

More from The Register

next story
Report: American tech firms charge Britons a thumping nationality tax
Without representation, too. Time for a Boston (Lincs) Macbook Party?
iPad? More like iFAD: We reveal why Apple ran off to IBM
But never fear fanbois, you're still lapping up iPhones, Macs
Apple orders huge MOUNTAIN of 80 MILLION 'Air' iPhone 6s
Bigger, harder trouser bulges foretold for fanbois
Child diagnosed as allergic to iPad
Apple's fondleslab is the tablet dermatitis sufferers won't want to take
Microsoft takes on Chromebook with low-cost Windows laptops
Redmond's chief salesman: We're taking 'hard' decisions
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
Cheer up, Nokia fans. It can start making mobes again in 18 months
The real winner of the Nokia sale is *drumroll* ... Nokia
prev story

Whitepapers

Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
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.
Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.