PCB Inspection & Testing Explained

PCB inspection and testing are essential steps in ensuring that a printed circuit board meets both quality and functional requirements.

While inspection focuses on detecting defects, testing verifies electrical integrity and performance.
Together, they form the final quality gate before PCB assembly or shipment.

This hub page provides an overview of the most important PCB inspection and testing methods and links to in-depth technical articles for each.

Quality foundation:
PCB-kvalitet og -pålidelighed forklaret

Why PCB Inspection and Testing Matter

Even with robust manufacturing processes, defects can still occur.

Inspection and testing help to:

• Detect manufacturing errors early
• Prevent defective boards from reaching assembly
• Provide feedback for process improvement
• Reduce reliability and field failure risk

They do not replace good design or process control, but they significantly reduce risk.

Automatiseret optisk inspektion (AOI)

AOI is the most commonly used inspection method in PCB manufacturing.

What AOI Does Well

• Detects surface-level defects
• Identifies opens and shorts visually
• Improves inspection speed and consistency

AOI-begrænsninger

• Cannot detect internal defects
• Cannot verify electrical performance

Deep dive:
AOI-inspektion i PCB-produktion

Røntgeninspektion

X-ray inspection enables visibility into the internal structures of a PCB.

What X-Ray Detects

• Via and hole plating voids
• Internal layer misalignment
• Delamination and resin voids

X-Ray Limitations

• Højere omkostninger
• Slower inspection speed
• Typically sampling-based

Technical details:
Røntgeninspektion i PCB-produktion

Elektrisk test af printkort

Electrical testing is the only method that directly verifies connectivity.

What Electrical Testing Confirms

• Kontinuitet i alle net
• Absence of shorts
• Korrekte netforbindelser

What It Cannot Do

• Predict long-term reliability
• Detect internal voids or plating thickness

Method overview:
Elektrisk test af printkort forklaret

Flying Probe vs Fixture-Based Testing

Once electrical testing is required, choosing the right method becomes critical.

Key Decision Factors

• Produktionsmængde
• Design stability
• Omkostningsstruktur
• Time-to-market

Comparison guide:
Elektrisk test med flyvende probe vs. armatur

Inspection vs Testing — Understanding the Difference

Both are necessary, but they address different risks.

How Inspection and Testing Work Together

A complete PCB quality system typically follows this sequence:

1. AOI for early surface defect detection
2. X-ray inspection for internal structures (when required)
3. Electrical testing for connectivity verification
4. Reliability testing for long-term performance (selective)

Reliability link:
PCB-pålidelighedstest forklaret

Cost Considerations in Inspection and Testing

Inspection and testing add cost, but skipping them increases risk.

Cost is influenced by:

• Bestyrelsens kompleksitet
• Volumen
• Inspection depth
• Valg af testmetode

Cost balance:
Afvejning af omkostninger og kvalitet ved PCB-produktion

When Enhanced Inspection Is Necessary

Enhanced inspection and testing are especially important for:

• PCB'er med høj densitet eller flere lag
• Nye designs eller materialer
• High-voltage or high-temperature applications
• Produkter med lang levetid

I sådanne tilfælde er standardinspektion alene utilstrækkelig.

I sådanne tilfælde er standardinspektion alene utilstrækkelig.

How Manufacturers Apply Inspection in Practice

In real production environments, inspection strategies are tailored to:

• Design risk
• Volume economics
• Customer requirements

At TOPFAST, inspection and testing methods are selected based on risk level and application needs, ensuring both efficiency and reliability.

Konklusion

PCB inspection and testing are essential safeguards that bridge manufacturing processes and real-world performance.

By combining AOI, X-ray inspection, electrical testing, and appropriate test strategies, manufacturers can significantly reduce defect risk and improve overall PCB quality.

This hub page serves as the central reference for the PCB-inspektion og -test emneklynge.

PCB Inspection & Testing FAQ