PCB Board – what is a printed circuit board and how do printed circuits work?

PCB as the foundation of modern printed circuits

A printed circuit board (PCB) is a fundamental structural component of almost every electronic device. Printed circuit boards enable permanent and organized connections of electronic circuits, providing mechanical stability as well as proper signal and power flow.

Modern printed circuits have replaced traditional wired connections, enabling miniaturization, automated assembly, and high reproducibility. In practice, a PCB serves as the foundation of the entire device – without it, reliable operation of electronic equipment would not be possible.

Soldering a printed circuit board – the assembly of electronic components on an FR-4 PCB during the printed circuit board manufacturing process.

Types of PCBs – from simple to specialized

Single-sided PCB and double-sided PCB

The simplest solution is a single-sided PCB, where the traces are located only on one side of the laminate. This type of universal single-sided PCB is often used in simple devices and educational projects.

A more advanced double-sided PCB allows traces to be routed on both sides, significantly increasing component density. A commonly used solution is also the universal double-sided PCB, which is utilized in service centers and laboratories.

Prototype PCBs – rapid testing and development

Prototype PCBs play a key role in the new product development process. Prototype PCBs allow for rapid verification of the schematic, creation of an early version of the electronic circuit, and validation of proper functionality before the start of mass production.

A single-sided prototype PCB is often used, allowing for a quick and cost-effective start to a project. It enables verification of the schematic, component placement, and the proper functioning of the electronic circuit at an early stage of development.

Universal PCBs for service and testing

Universal PCBs are ready-made solutions with a grid of holes, providing easy assembly and high flexibility. A universal printed circuit board (PCB) is commonly used in service centers, education, and short test series.

PCB Assembly – THT and SMD Technologies

The assembly of electronic components on PCBs is most commonly carried out using two technologies:

• THT (Through-Hole Technology) – components inserted through holes, providing high mechanical durability
• SMD (Surface-Mounted Devices) – components mounted on the surface, predominant in modern electronics

In practice, PCBs are often assembled using a mixed technology, combining THT and SMD components within a single design.

A printed circuit board with SMD (Surface-Mounted Devices) – a modern double-sided PCB used in printed circuit board manufacturing.

PCB Material and Its Impact on Quality and Durability

The selection of material is crucial for the quality and durability of a PCB. The most commonly used laminate is FR-4, which offers a good balance between cost and mechanical and electrical properties.

Other popular PCB materials include:

• FR-2, FR-3
• CEM-1, CEM-3
• Polyimide (PI) – for flexible circuits
• PTFE (Teflon) – for high-frequency applications
• LCP and Rogers laminates – for advanced applications

In the case of lighting applications, MCPCBs, or metal-core PCBs on an aluminum substrate, are used, which effectively dissipate heat.

Design and Manufacturing of Printed Circuit Boards

The design process of printed circuit boards is carried out using specialized CAD software, such as:

Automotive

In the automotive industry, PCBs operate in environments with elevated temperatures, exposure to vibrations, moisture, and aggressive chemical agents. They are used, among others, in engine controllers, ADAS systems, comfort modules, vehicle lighting, and infotainment systems. Automotive PCBs must meet strict quality standards and be characterized by long service life and high mechanical durability.

Medical Equipment

In medical equipment, the printed circuit board plays a key role in ensuring measurement precision and patient safety. It is used, among others, in diagnostic devices, vital signs monitors, laboratory equipment, and imaging apparatus. High manufacturing quality, stable electrical parameters, and compliance with medical standards are required. Specialized PCBs with enhanced reliability are often employed.

Industrial Automation

Industrial automation relies on PCBs used in PLC controllers, sensors, inverters, communication modules, and process control systems. PCBs must operate continuously, often 24/7, maintaining stable parameters despite temperature variations, dust, or electromagnetic interference. Durability and resistance to long-term operation are of key importance in this field.

Universal printed circuit board with traces – a prototype PCB for testing, adapters, and assembly of electronic components.

LED Lighting

The military industry requires the use of specialized PCBs with the highest level of reliability. Electronic systems must operate under extreme conditions – with large temperature fluctuations, shocks, high humidity, and in environments with significant electromagnetic interference. PCBs are used, among others, in communication systems, drones, radars, onboard electronics, and special-purpose devices.

Contract Electronics Manufacturers (CEMs)

For contract electronics manufacturers (EMS), PCBs form the foundation of the entire production process. Both prototype PCBs for testing and validation, as well as complete PCBs for mass production, are used. Key factors include consistent quality, compatibility with automated assembly, and the ability to scale production from small batches to large volumes.

Printed circuit boards are applied in almost every industry. Depending on the working environment, either specialized PCBs or standard printed circuit boards are employed.

PCB Adapters and Auxiliary Solutions

In engineering practice, adapters and sockets play a crucial role, significantly facilitating testing, servicing, and integration of various standards and formats of electronic circuits. PCB adapters allow for quick connection, replacement, and diagnostics of components without interfering with the target board, which is why they are commonly used in research and development laboratories, service centers, and during validation and commissioning of new projects.

PCB Cleaning Agent – a substance for removing contaminants from printed circuit boards after assembly and soldering.

A good choice of PCBs should take into account:

• Type of application

• Temperature and mechanical requirements

• PCB types and materials

• Economic considerations, including available PCB options and purchase prices

A properly selected PCB requires a carefully planned design, but in return, it enables high reliability and long service life of the devices.

Applications of PCBs – Summary

Whether you are designing a simple prototype or producing a series of complete printed circuit boards for industrial use, a well-designed and manufactured PCB remains the foundation of modern electronics. It is precisely the advantages of PCBs that determine the quality, durability, and functionality of electronic devices today. Therefore, selecting the appropriate materials and technological agents is equally important — AG TermoPasty offers a wide range of specialized PCB products, including fluxes, cleaning agents, protective substances, as well as materials that support the soldering process and the long-term reliability of circuits.

PCB Board – what is a printed circuit board?

PCB Board – what is a printed circuit board and how do printed circuits work?

PCB as the foundation of modern printed circuits

Types of PCBs – from simple to specialized

Single-sided PCB and double-sided PCB

Prototype PCBs – rapid testing and development

Universal PCBs for service and testing

PCB Assembly – THT and SMD Technologies

PCB Material and Its Impact on Quality and Durability

Design and Manufacturing of Printed Circuit Boards

Applications of PCBs in Industry

Automotive

LED Lighting

Military Industry

Contract Electronics Manufacturers (CEMs)

PCB Adapters and Auxiliary Solutions

How to Choose the Right PCB?

Applications of PCBs – Summary