Samsung’s flagship smartphone incorporates a major innovation in chip manufacturing.
Just how innovative is Samsung’s latest top-of-the-range Galaxy S7 smartphone? Much-hyped waterproofing aside, both the S7 and its curved-screen sister, the S7 Edge, are primarily performance plays. And once you look at the hardware innovation, it proves an impressive piece of engineering.
The company itself has made much of the fact that the S7 uses liquid cooling, but this comes in the form of a well-established technique, the heat pipe. Albeit, according to iFixit’s Teardown team, a tiny one that allows liquid to travel along it as vapour with a width of less than 0.5mm. Still, the S7 is not the first phone to use this technology even if it has been tremendously scaled down.
That heat pipe, though, is just an enabler. It pulls heat away from the handset’s Exynos adaptation of Qualcomm’s Snapdragon 820 processor, a 2.15GHz + 1.6GHz 2x-quad-core design in an ARM Big.Little configuration. The slower processors handle simpler tasks, consuming less energy to perform them and extending battery life.
Given better standard software – although there have been complaints that Samsung could reduce the in-house bloatware further in its implementation of Android 6.0 Marshmallow – and a chunkier battery (3000mAh v 2550mAh for last year’s S6), the S7 can do a lot both more efficiently and for much longer than its predecessor, and about as well as rivals such as the latest iPhone and Nexus models.
Some of the most significant hardware improvements, however, concern the main rear-mounted camera.
For the owner, the big innovation here is that Samsung has brought dual-pixel autofocus technology across from the world of digital SLR photography. This uses phase detection across two prism-split images to analyse the field of view with greater fidelity. Samsung is also making this work for a 12MP array with 1.4µm pixels. According to Chipworks, this compares with the use of 4µm pixels in SLRs. Its conclusion: “The results are stunning – the S7’s photos are of high quality, especially when viewed on its Quad HD (2560×1440, 5.1-inch) AMOLED display.”
But Chipworks dug deeper and discovered something here of potentially greater importance for the engineering community. The S7’s image sensor, Sony’s new IMX260 device, “leads the digital image sector into an era of hybrid bonding”.
Chipworks speculates that this may involve direct-bond interconnect technology from Tessera subsidiary Ziptronix.
“The successful rollout of wafer-to-wafer direct bonding has broader implications for the general semiconductor industry, but it’s especially important to the image sensor community,” Chipworks notes. “We’ve been seeing this technology in literature for a few years now, but the IMX260 represents the first known direct-bond interconnected chip to be used in such a high-volume consumer application as the Samsung Galaxy S7 camera.”
A cross-section of the IMX260 revealed a five-metal-layer CMOS sensor attached to a seven-metal-layer image processor die, with 3.0µm copper-to-copper vias. Via pitch is 14µm in peripheral regions and 6.0µm in the active pixel array.
Also interesting is the fact that Samsung has opted for Sony technology in the S7’s main camera slot over its own digital imaging silicon. But this is the kind of thing consumers should expect from flagship devices.
On a comparatively more mundane level, Samsung also earns a tip of the hat for eschewing the trend towards forcing users to store media in the cloud. It has included an option to add up to 200GB in memory card storage. Depending on the region, the S7 comes with either 32GB or 64GB on board.
So that’s the good news. The bad news is that, despite its hefty £570 unlocked retail price, you will again need to treat your S7 with care.
As on the S6, the iFixit analysis found great globs of glue holding much of the S7 together. Replacing the front glass is virtually impossible without destroying the entire display. Worse, the display needs to be removed – and therefore probably destroyed – just to replace the USB port. Battery replacement is similarly challenging. The fact that many of the components inside are modular is basically moot.
For repairability, iFixit marks down the S7 from the S6’s 4 to just 3 out of 10.
It’s a pity, then, that both Google and Samsung seem to have adopted Apple’s fetish for design-for-user-discouragement, DUD for short – particularly since the S7 is otherwise anything but.