How is PCB Quality Maximized?

Why PCB Quality is Critical

Printed Circuit Boards – PCBs are the foundation of every electronic device. The quality of their production affects not only the functionality and reliability of the device, but also its lifespan, electromagnetic properties, and assembly capabilities. Low PCB quality can lead to field failures, higher rates of returns, or costly repairs and modifications. At Gatema, PCB quality is taken very seriously – every process is managed to meet the highest standards, including certification for the aerospace industry under AS9100.

1. Overview of Key Quality Factors

From industrial practice, PCB quality is critical in the following areas:

1. Selection of materials and their specifications,
2. Accuracy of patterns, including photolithography,
3. Precision of drilling and hole manufacturing,
4. Uniformity and type of surface finishes,
5. Thorough testing,
6. Cleanliness of processes and chemicals,
7. Data preparation and customer–manufacturer communication (DFM).

Each of these factors significantly affects the final board and its electrical and mechanical properties.

2. Material (FR-4, Specifications, Certification)

The material from which the PCB is made is the foundation of PCB quality. FR-4 is the most commonly used material, but its parameters can vary depending on the manufacturer and specific datasheets. Important properties include:

• Thermal resistance (Tg),
• Coefficient of thermal expansion (CTE),
• Dielectric properties (Dk/Df),

which influence soldering stability and signal integrity, especially for high-speed applications. Harder materials with higher Tg are suitable for demanding environments, while flexible materials are used for flex and rigid-flex boards. Gatema PCB offers boards with various materials, including flex and rigid-flex structures.

3. Photolithography and Copper Layer Accuracy

The copper traces on each layer of a board are created through photolithographic processes – from CAM data preparation through exposure to etching. Gatema PCB uses a modern pattern transfer system that includes digital printing and screen printing, achieving high PCB quality and enabling the production of fine structures.
A key parameter here is the minimum trace width and spacing, which can be around 75 µm for standard PCB technologies.

4. Drilling Control – Holes, Tolerances, Dimensional Accuracy

Precise drilling is essential for:

• PTH (Plated Through Holes),
• Blind and buried vias,
• Microvias for HDI PCBs.

Gatema PCB can produce microvias with diameters up to 0.12 mm for PTH and 0.15 mm for blind vias, allowing high routing density even on compact boards.

Precision drilling is important not only for electrical connections between layers but also for mechanical stability and reproducibility of production.

5. Surface Finishes and Their Uniformity

Copper surface finishes protect traces from oxidation and ensure reliable soldering. Gatema PCB typically offers various surface finishes:

• HAL (lead-free or PbSn),
• Immersion tin and gold (ENIG),
• Gold for connectors,
• Other specialties like solder masks and silkscreen.

Uniform application of surface finishes is essential to minimize soldering issues, ensure PCB quality, and maintain long-term reliability.

6. Testing: AOI, Electrical Tests, Impedance

Each board undergoes inspection through:

• Optical and electrical testing (AOI and E-Test),
• Impedance measurement where specified.

These inspections detect pattern defects, poor connections, or shorts before shipment, ensuring high PCB quality.

7. Cleanliness and Chemical Process Compatibility

Chemical processes – etching, plating, cleaning – must occur in a clean and stable environment. Contaminants can negatively impact solderability, mechanical integrity, or electrical characteristics. Gatema PCB maintains strict chemical process control and operates an automatic wastewater neutralization station, ensuring both product quality and environmental compliance, thus supporting PCB quality.

Case Study: Gatema PCB

Gatema PCB is a Czech PCB manufacturer with over 30 years of experience, producing boards for customers across Europe.
In its manufacturing process, the company uses:

• CAM department with a modern data preparation system,
• CNC drilling, milling, and slotting machines,
• Photolithography processes with digital printing,
• Chemical processing lines (cleaning, etching, plating),
• Automated multilayer pressing equipment,
• A wide range of surface finishes,
• Electrical and optical testing.

The company also integrates modern digitization and automation (Industry 4.0), linking MES systems with ERP for fast data processing and production optimization. Gatema PCB is AS9100 certified for the aerospace industry and regularly innovates processes, enabling it to produce high-quality PCBs even for demanding applications.

How Customers Can Influence Quality

Customers can significantly influence the final PCB quality by:

• Providing properly prepared manufacturing files (Gerber, ODB++/IPC-2581),
• Using design-for-manufacturability (DFM) consultations,
• Choosing the appropriate stack-up and materials for the application,
• Specifying impedance control where required.

Proper communication and collaboration with the manufacturer minimize errors, accelerate production, and support high PCB quality and product performance.

Conclusion

PCB quality results from a combination of technical and process factors – from materials through precise processing to thorough testing. By integrating modern technologies, automation, and quality control, a manufacturer like Gatema PCB ensures high reliability and repeatability in production.

If you are preparing a new project or want to verify the manufacturability of your design, Gatema PCB offers consultation with PCB manufacturing experts who can help optimize your data, resolve potential issues, and accelerate production.