Why PCB Failure Happens: 6 Issues OEMs Can Avoid

Printed circuit boards (PCBs) are the foundation of almost every electronic product. When one fails, the results can include product recalls, costly downtime, warranty claims, and unhappy customers. While any company would find this frustrating, OEMs and B2B electronics manufacturers face even greater risks, including lost contracts, delayed shipments, and damage to their reputation.

The inherent complexity of modern PCBs — with their ever-increasing density, miniaturization, and higher operating frequencies — makes them more susceptible to subtle defects that can be challenging to detect. This complexity underscores the need for robust quality control throughout the entire manufacturing chain.

Most PCB failures don’t happen at random. They often result from a handful of avoidable problems. Whether you’re sourcing fully assembled boards or integrating them into your final product, understanding these common failure points can help prevent problems before they reach your customer.

Common Causes of PCB Failures

Most circuit board failures fall into a few repeatable categories. These include:

• Manufacturing defects
• Burnt components
• Environmental stress
• Soldering issues
• Human error
• Aging materials and components

Preventing a PCB malfunction starts with solid design and ends with disciplined quality control. The sections below explore each of these causes in more detail and share practical tips for OEMs looking to reduce PCB failures.

1. Manufacturing Defects

One of the biggest contributors to PCB failure is a mistake during the manufacturing process. These issues aren’t always obvious right away. They can show up weeks or months later during use.

Common PCB defects include:

• Layer misalignment in multilayer boards can break circuit continuity
• Poor via plating, which causes unreliable connections between layers
• Delamination due to bonding problems or uneven heating
• Trace width inconsistencies that lead to hotspots or performance loss

For B2B buyers, selecting a PCB supplier with strong process controls and IPC-certified inspectors is critical. Don’t skip over questions about their quality systems during vendor qualification.

PCBs are extremely sensitive to electrostatic discharge (ESD), and though we can only feel ESD in the thousands of volts, the smallest discharge can cause a component defect. This can be latent (meaning the PCB remains functional but suffers from downgraded reliability) or catastrophic (meaning permanent damage has been done).

Mitigation Tip for OEMs: Choose a contract manufacturer that uses ESD-safe protocols, anti-static tools, and controlled environments as standard and ensures stringent cleanliness protocols throughout the entire manufacturing and assembly process. This attention to detail prevents costly recalls and downstream integration issues.

2. Burnt Components

Burnt components are technically a type of PCB defect, but it’s worth noting as a major cause of PCB failure. A burnt component can compromise the entire PCB and demand a full board replacement. 

The three main causes of burnt components include:

• Extreme heat: If a machine overheats or a board is exposed to direct flame, the chances of a heat-related defect increase. PCBs should have a Tg (glass transition temperature) of 170°C and an operating temperature of 25°C less than the Tg.
• Improper component spacing: Components that are too close together on the circuit board could heat up, impacting the performance of adjacent parts. Designing PCBs to have the optimum amount of space is crucial for avoiding heat-related defects. 
• Component failure or technician error: If a board isn’t hooked up correctly or the voltage protections aren’t up to par, a board is at a higher risk of burning out. Clear, well-documented hook-up instructions can help alleviate technician error. 

3. Environmental Factors

A PCB’s long-term reliability depends on the conditions it faces during operation. Heat, humidity, dust, and vibration all contribute to long-term degradation or early failure.

OEMs designing electronics for rugged environments must account for:

• Moisture ingress, leading to delamination or conductive pathways
• Contaminants (dust, fibers, hair) introduced during production
• Thermal cycling, which expands and contracts the board material, stressing solder joints

Pro tip: Ensure your boards undergo accelerated life testing and conformal coating if reliability in harsh environments is a requirement.

4. Soldering Issues

Solder is a key ingredient in the PCB process. It’s what maintains the contact between a component and a circuit. Improper soldering can introduce a wide range of failure modes, including: 

• Opens
• Excessive solder
• Component shifting
• Cold joints
• Solder bridges
• Webbing and splashes
• Lifted pads
• Tombstoning

These problems often occur in high-mix, low-volume production or when reflow settings are not properly controlled.

Well-trained assemblers, robust quality checks, and automated optical inspection (AOI) help catch these issues before they reach final testing or the end user.

5. Human Error

Human error still plays a role in circuit board failure, especially in custom builds or first-article assemblies. Examples include:

• Misreading component polarity
• Incorrect part loading
• Insufficient process documentation
• Incomplete burn-in or test procedures

For OEMs relying on a partner for PCB assembly or repair, process discipline is non-negotiable. Be sure your partner adheres to IPC-A-610 Class 2 or 3 standards, depending on your industry.

6. Age

PCBs have a finite service life, just like any other mechanical or electronic system. Over time, materials degrade, components fail, and signals can become unreliable.

When supporting legacy products or field returns, working with a contract manufacturer that offers PCB failure analysis and aftermarket services (such as board-level repair and rework) can extend product lifecycles and protect your bottom line.

Looking Beyond the Immediate PCB Board Problem

The most productive OEMs respond to a faulty PCB and also design to prevent it. That means looking beyond one faulty PCB and investing in:

• Better supplier vetting
• Early-stage DFM (Design for Manufacturability) review
• Root cause failure analysis
• Ongoing reliability testing

These steps reduce future downtime, warranty costs, and customer dissatisfaction, especially in safety-critical or mission-critical devices.

Stay Ahead of PCB Failures

PCB failures are rarely random. Most result from issues that can be identified and addressed early in the design, manufacturing, or testing process. Common contributors include manufacturing defects, environmental stress, soldering problems, and aging components.

OEMs that take a closer look at supplier capabilities, testing procedures, and long-term reliability can reduce field failures and production delays. Careful planning and quality control lead to more dependable performance and fewer unexpected issues after deployment. 

Want more insights on preventing PCB failures and improving reliability? Visit the Matric blog for expert tips, technical resources, and real-world guidance tailored to OEMs and electronics manufacturers.

(Editor's Note: This post was originally published in 2018 and was updated in June 2025.)