Current Technology Advancements Leading to Smaller Mobile Devices
Modern mobile devices are becoming smaller, lightweight and more portable with each generation. There are a few core technological advances that have allowed devices to evolve in this way without sacrificing power and functionality. In particular, high density interconnect PCBs have provided mobile device designers the ability to create extremely powerful devices in a very small package.
High Density Interconnect PCBs
High density interconnect PCBs (also known as an HDI PCB) are able to provide the same functionality as other printed circuit boards but within less area. The standard HDI PCB uses a multi-layer copper-filled stacked micro-structure, building up layers of high-density interconnections. With an HDI PCB, extremely complex structures can be created that would otherwise demand more space. HDI PCBs have been instrumental in creating smaller CPU and GPU microchips, which have in turn created smaller and more powerful mobile devices.
Components used in HDI PCBs are similarly streamlined and miniaturized, to provide an even more appealing power to size ratio.
Curved, Stepped and Cabled Batteries
Battery packs have been problematic as mobile devices have moved towards becoming both thinner and lighter. New innovations in the battery technology world include curved, stepped and cabled batteries. Curved batteries would move with the device, allowing for radically new form factors. Stepped batteries would include battery packs that were in a modular "stepped" format, and could thus be fit more neatly into a device and around the PCB. Cabled batteries will be low-yield, flexible batteries for smaller devices -- such as wearable technology.
Integrated Touch and Display Controllers
Traditionally, touch and display controllers have been separate for touch screen devices. The integration of touch sensors into the display chips reduces the required size of a device. Today, virtually every mobile phone -- even those that are not traditionally "smart" -- has a touch screen. Touch screen technology, on its own, also lessens the need for more mechanical parts within the device (such as a physical keyboard), thereby again reducing the size of the device itself.
PCBs likely have the most impact on whether or not a smartphone can achieve a smaller size. CPUs and GPUs make up a significant amount of the device's function, with peripheral devices -- such as cameras and speakers -- demanding a largely negligible device footprint. As PCBs and battery packs become smaller, devices will continue to become thinner and lighter.