What are PCBs? || How do PCBs Work?

Summary

This video explores how Printed Circuit Boards (PCBs) work, breaking down their vital role in smartphones. It explains how these multilayered boards connect components like cameras, microchips, and displays, allowing them to communicate seamlessly. The video covers PCB structure, materials, and the use of vias to connect different layers. It also highlights the engineering behind creating smaller, more efficient devices and encourages viewers to consider a career in STEM to contribute to future technological innovations. A great introduction to understanding the complexity and importance of PCBs in modern electronics.

Takeaways

• 😀 PCBs (Printed Circuit Boards) are essential in modern electronics, providing the structure and organization for components like microchips, cameras, and displays to work together seamlessly.
• 😀 A typical smartphone contains over 110 meters (360 feet) of wiring inside, all of which is organized in a PCB to allow the components to communicate.
• 😀 The PCB is a multilayered structure, with conductive copper layers separated by insulating materials like woven fiberglass and epoxy resin, which prevent electrical short circuits.
• 😀 The term 'motherboard' refers to the entire PCB with components mounted on it, while a 'PCB' is simply the bare flat board without components.
• 😀 PCBs often have multiple conductive layers—this smartphone's PCB has 10—each serving different purposes, such as power and ground planes, communication traces, and electromagnetic shielding.
• 😀 Vias are small drilled holes in a PCB that connect different layers, ensuring signals can travel from one layer to another without interference.
• 😀 Components like microchips, resistors, and capacitors are mounted to the PCB, either directly or through connectors like flat cables for devices such as displays and cameras.
• 😀 The 'System on a Chip' (SoC) is the brain of the smartphone, mounted on the PCB, and connected to other components via thousands of tiny electrical traces.
• 😀 Modern smartphones often use advanced PCB designs such as stacked or separated boards to maximize space and accommodate features like larger batteries and multiple cameras.
• 😀 Engineers are constantly working to make components smaller and more efficient, leading to innovations like surface-mount devices (SMDs), which replace older through-hole designs and enable more compact PCBs.

Q & A

What is the role of a Printed Circuit Board (PCB) in electronics?

A PCB provides the structure for mounting electronic components like microchips, capacitors, and resistors, and facilitates communication between them via electrical connections called signal traces.

What materials make up a typical PCB?

A typical PCB is made from a woven fiberglass base material, combined with an epoxy resin binder (FR4), and contains copper layers embedded for electrical conductivity. Insulating layers prevent electrical interference.

How does a PCB allow communication between components?

Communication between components is achieved through tiny copper wires, known as signal traces, which are routed through the layers of the PCB. These traces carry electrical signals that enable the components to work together.

What are vias in a PCB, and why are they important?

Vias are metal-plated holes drilled through the PCB that allow electrical signals to pass between different layers. They are crucial for connecting multiple layers of the board and ensuring the proper functioning of the entire system.

What are the different types of vias used in PCBs?

There are three types of vias: through vias (which pass from the top to the bottom layer), blind vias (which connect the top or bottom layer to an inner layer), and buried vias (which connect internal layers to one another).

How many layers can a PCB have, and what do they do?

PCBs can have anywhere from 2 to over 50 layers. These layers include the top and bottom layers for mounting components, power and ground planes, and signal layers that carry electrical signals between components.

Why do PCBs use surface-mount devices (SMDs) instead of through-hole components?

SMDs are used because they allow for smaller, more compact designs. They are soldered directly onto the surface of the PCB, unlike through-hole components that require holes to pass through the board, saving space and making the manufacturing process more efficient.

What is the significance of the System on a Chip (SoC) in smartphones?

The SoC is the main microchip in smartphones, responsible for processing and managing all of the device's operations. It is mounted on the PCB and connected to various other components via traces that enable data transfer and communication.

How do engineers manage the tiny size and complexity of modern PCBs?

Engineers use advanced techniques like multi-layer design, surface-mount technology, and precise routing of signal traces to fit thousands of components into a small space while maintaining efficient electrical connections and minimizing interference.

How do PCBs help improve the overall size and performance of electronic devices?

PCBs make electronic devices smaller, lighter, and more efficient by providing a compact, organized space to mount components and route electrical connections, which allows for more powerful devices with a smaller footprint.