Modern smartphones are extremely complex, multilayered devices, so we must be adequately familiarized with recognizing the components on a standard smartphone. This is a basic, but absolutely crucial step for learning what goes where.

The Two Prime Area Divisions on Smartphone PCBs

All components on the PCB of any smartphone will have two primary area divisions:

  1. Network Section – The area in between the Antenna Point and the Power Section
  2. Power Section – The entire area below the Network Section

Antenna Point

The antenna point is quite simply the location where all phone antennas have been connected to the circuit board, right at the top.

Network Section: Antenna Switch

Generally a semi-metallic component with 16 legs, it’s the first component you will see below the antenna point, and right on top of the Network Section.

Network Section: Power Frequency Oscillator

Depending on the layout, the Power Frequency Oscillator (PFO) could be a component which you will see right beside the antenna switch, or it could be fused together with the switch itself.

Network Section: Network IC

Finally, we have the last Network Section component that we generally see on a mobile phone’s circuit board, aka, the network IC. It too might be merged in some cases, but the merger will not be with any of the Network Section components. If you cannot locate the Network IC, then it likely means the manufacturers have placed it into the Power Section, merging it with the Power IC.

Power Section: Power IC

If not merged with the network IC, the power IC will be the first component in the Power Section that you will come across, right below the Network IC. When merged together with the network IC, it will be seen as thefirst component in the Power Section, right below the antenna switch and the PFO.If you see two power ICs, then that’s also pretty common in modern smartphones.

Power Section: Central Processing Unit (CPU) and Flash IC

Smartphone CPUs like the Samsung Exynos chips and high-end SD chips will often have one low powered, as well as one high-powered CPU component on the PCB next. It’s difficult to miss, whether there are one or two, since this is the biggest component on a smartphone PCB. The IC beside the CPU/CPUs is the Flash IC.

Power Section: Logic IC, Audio IC and Charging IC

The three can be located in different locations of the Power Section, as it varies a bit, depending on the smartphone’s model.Even then, the following should provide readers with a decent idea on how to recognize them:

  • Logic ICs have 20 legs usually, wherever in the power section it might be located
  • The Charging IC should be located very close to the Power IC
  • In a large majority of the layouts, the audio IC is the one that’s right beside the power IC/ICs

Where Will You Find the Replacement Components?

Most repair jobs associated with smartphone circuit board repairs will usually require you to manually repair or completely replace one of the components we just mentioned. As long as you have the model and size right, you will find every smartphone PCB component at Octopart, along with components for any other type of PCB. Advanced, high-end smartphones may have multiple additional components as well, and they have nearly everything you may need for repairing them too.

Hopefully this short guide has helped you to become more familiar with the components of a smartphone PCB.