Mobile phones have gone a long way. After all, they were considered a breakthrough decades ago simply because they eliminated the need for telephone wires! Now, mobile phones went up the next level, as they already function as mini computers. What’s even more amazing is that today’s mobiles don’t rely so much on physical buttons – navigation is mainly done by touching the screen. Many years ago, that was merely science fiction. Mobile phones aren’t merely capable of making calls and sending messages, they can capture photos, record videos, play music, surf the internet, read fingerprints, and even measure heart rates! No wonder mobile phones are now called smart phones.


What makes these phones smart? The answer lies in the printed circuit board. The printed circuit board is essentially the backbone of every Smartphone in existence. Even the phone’s A8 chip or Samsung’s Eryngoes 7420 chipset will be rendered useless if not properly attached to a printed circuit board. If you’re wondering what the PCB looks like, you’ll be surprised that it’s the green or blue board found inside a Smartphone and in all other electronic communications devices. It’s where all the other components are attached to, which is why PCBs from different devices don’t look the same.

How relevant then is the printed circuit board for a smart phone? Being the one that connects every other component, the printed circuit board is expected to contain or process all the necessary electronics and algorithms for the handset to function. When the first mobile phone was invented, it was only designed to make calls, which means its printed circuit board has the electronic components necessary for making calls. Still, the printed circuit board can be altered depending on the design of the Smartphone. Flip or slide phones usually use a flexible printed circuit board.

The conductors on a flexible printed circuit board are usually bonded to a thin dielectric film. With the demand for slimmer phones, Smartphone companies not only compete in terms of software features but also in style, appearance, size, weight, and battery life. Slimmer phones require slim PCBs, more advanced software requires complex electric circuits and may take up a lot of space, yet printed circuit boards are able to meet expectations when it comes to both software and the hardware.

How does the printed circuit board meet such qualifications? One innovation that made it possible is the HDI or High Density Interconnect PCBs. HDIs are slimmer than normal printed circuit boards, yet are much dense and can support more functions per unit area. These cutting-edge PCBs are characterized by finer lines and spaces, smaller vias, and more compact capture pads.

Today, it’s possible to shrink an 8-layer printed circuit board down to a 4-layer HDI PCB. Of course, the latter can still achieve the same (or better) functions compared to a traditional printed circuit board. Reducing the printed circuit boards layers also helps reduce the overall cost of the product, which is an advantage for consumers.

Compared to the traditional printed circuit board, HDI PCB has higher speed, performance, and frequency. That is the reason why smart phones aren’t the only ones equipped with the latest PCBs, as many portable computers, game consoles, wearable’s, and personal digital assistants also rely on those crucial components.

No one can stop technology from progressing, which makes engineers face more problems when coming up with new printed circuit board designs. Perhaps early involvement in the design process would be helpful to arrive at the best solution. But no matter what the future unfolds, you can expect that printed circuit boards will continue to develop beyond HDI. Who knows, in the near future, you might even see printed circuit boards in never-before- seen shapes.