As one of the most basic components of almost every consumer electronics product, the microchip is emerging as a very interesting phenomenon, usually thin and flat microchips, which are now stacked like pancakes, changing from two-dimensional to three-dimensional - to electronic devices Bring significant impact
Chip designers are discovering the kind of stacking that can bring unexpected benefits in terms of performance, power consumption and functionality.
Without this technology, Apple Watch Apple Watch will not be able to make it, Samsung's most advanced solid-state memory, artificial intelligence systems from NVIDIA and Google and Sony's super-fast new camera is no exception.
This 3D stack is akin to urban planning, and without it, as the product requires more components built-in, the microchip on the board stretches further and the distance between the microchip farther apart. However, once started By stacking the chips, you can create a silicon 'city' where everything becomes more adjacent.
From a physical point of view, the benefits of this design are obvious: when the electrons need to travel longer distances over copper, they consume more energy, generate heat, and reduce their bandwidth. ARM's Microchip Design Company Greg Yeric, director of future silicon technologies at ARM Research, notes that stacked chips are more efficient, generate less heat, and communicate at much shorter interconnections at light speed.
Although the principle behind 3D stacked chips is simple and straightforward, it's not easy to make, said Yerick, first introduced in the 1960s and sporadically in high-end applications such as military hardware.
However, Sinjin Dixon-Warren, an analyst at TechInsights Microchip Research Inc., points out that small form factor specialist companies such as most major chip makers (AMD, Intel, Apple, Samsung and NVIDIA) and Xilinx Stacked chip products, only appeared for about five years.Why should we do this? Because engineers began to find no other way to make the chip better performance.
Stacked chips are often part of the 'wrapper' of other curled chips, which allows vendors to build many different chips (through different manufacturing processes) and then glue them more or less apart from saving space. The '3D stacked package' approach differs from the 'system-on-chip' approach that is frequently used in cell phones, where all different cell phone components are etched onto a single piece of silicon.
Dickson-Warren said Apple Watch has been powered by one of the most advanced 3D stacked chip packages since the first generation, in which 30 different chips are sealed in a plastic wrap, he said , In order to save space, the memory chip stacked on the logic circuit.If no chip stacking technology, the watch's design can not be done so compact.
Apple's chips are simply two-ply stacks, while Samsung has made the veritable silicon-based 'high-rise buildings'. Samsung has a 64-layer stack of V-NAND flash memory for cell phone, camera and laptop data storage. Just announced that the future version will have 96 layers.
Storage is a natural application of the chip stacking technology because it solves a problem that has long plagued chip designers: adding more cores to any device from the iPad to the supercomputer does not translate to the desired speed Because of the delay in communication between logic circuits and the required storage capacity, stacking storage components directly on the chip can shorten the connection path between the two.
Brian Kelleher, senior vice president of hardware engineering at NVIDIA, said that's exactly how the company's Volta microprocessors, built for AI, operate by stacking eight layers of high-bandwidth memory directly onto the GPU, Created a new record of efficiency.
'We are limited in power,' Kehler said. 'Any power we can free up from the storage system can be used in computing.'
Chip stacking has also brought some new features.Many mobile phone camera image sensor directly superimposed on the image processing chip above the extra speed means that they can take multiple exposures photos and put it together in the Dim scene capture more light.
The prototype camera from Sony goes one step further by using triple-layered rather than two-layer chips - including image sensors, memory and logic, for up to 1000 frames per second - the effect of this approach is the photo-touch image sensor, Direct access to memory, followed by real-time processing. In addition to achieving higher visibility in low light conditions, this can also be used to shoot ultra-slow motion video, single frame solidification of fast-moving objects.
At present, pushing 3D microchips to more electronic devices also requires enormous resources to solve some of the obstacles.
In the first place, soon after the birth of the 3D chip, evolutionary design tools for stacking have not evolved enough, says Yerick, and until simple design tools - similar to those used to flatten chips - have become widely available, stacked The chip will still only be able to create a business with top engineering talent.
Another problem is that manufacturers are still learning how to reliably physically stack and connect chips to each other, which means some manufacturing processes yield relatively little.
However, Dixon-Warren pointed out that the popularity of 3D stacked chips is very fast, and they will inevitably become the mainstream of the industry.Over 10 years ago, the technology is almost only exist in the university laboratory; five or six years ago, it is difficult to find its Commercial case.But it is now sprung up in various applications, such as networking, high performance computing and high-end wearable devices such as Apple Watch.According to the well-known electronic product disassembly site iFixit CEO Kyle Wei Kyle Wiens said it also appears in iPhone X's 'brain.'
At Jericho ARM, the final 3D chip should make our wearable products as powerful as larger devices, allowing them to run continuously for days even if they are full of sensors. It would not surprise me if your watch would one day be able to check your blood sugar levels, 'he said.
Getting the chip from two-dimensional to three-dimensional is just the beginning. Soon after, the chip layer will communicate with light instead of current. In the more distant future, as we use shiny crystals with unprecedented processing performance Replace the circuit board, they will completely get rid of silicon - may turn to artificial diamonds.