Printed Circuit Boards (PCBs) are the foundational platform for electronic components, providing mechanical support and electrical connectivity in virtually all modern electronics. Below is a structured overview of their key aspects:

Definition and Purpose

PCBs are insulating substrates (e.g., fiberglass-reinforced epoxy resin like FR-4) with etched copper pathways. They replace manual wiring, enabling compact, reliable circuits by:

• Interconnecting components (e.g., resistors, ICs) via conductive traces 

• Supporting automation in manufacturing and repair 

   

Basic Structure

A typical PCB consists of layered materials:

• Base Substrate: Insulating layer (e.g., FR-4) 

• Copper Layer: Etched conductive pathways 

• Solder Mask: Protective coating (usually green) preventing shorts 

• Silkscreen: Labels for component placement (e.g., "R1" for resistors) 

• Vias: Metallized holes connecting multiple layers 

Key Components Mounted on PCBs

Classification of PCBs

• By Layer Count:

  • Single-sided: Copper on one side (e.g., remote controls) 

  • Double-sided: Copper on both sides, connected by vias 

  • Multilayer (4+ layers): High-density interconnects (e.g., smartphones, servers) 

• By Material Flexibility:

  • Rigid: FR-4-based (e.g., motherboards) 

  • Flexible: Polyimide films (e.g., wearables, foldable phones) 

  • Rigid-Flex Hybrid: Combines rigid/flex zones (e.g., camera modules)

     

• By Application:

  • High-Frequency: For RF/wireless devices (low signal loss) 

  • High-Density (HDI): Micro-vias for compact designs (e.g., laptops) 

  • High-Power: Thick copper for current handling (e.g., EV chargers)