PCB delamination is one of those defects that can affect product reliability if it is not spotted early. It affects the structural integrity of a printed circuit board and if left unchecked, can lead to electrical failures, reduced lifespan of the product or even complete product breakdown. No matter which part of the manufacturing process you work in, understanding what PCB delamination is and how to prevent it is really important.
In this guide, we will break down what PCB delamination actually is, what causes it, how to spot it and most importantly, how to prevent it. We will also touch on how standards like IPC-A-600 help define what is acceptable and what is not when it comes to this defect.
What Is PCB Delamination?
PCB delamination refers to the separation of layers within the board. A typical PCB is made up of multiple layers bonded together using heat, pressure and resin systems. When those bonds weaken or fail, the layers can begin to separate.
This separation can appear as:
- Blistering on the surface
- Air gaps between layers
- Lifting or peeling of the laminate
- Discolouration or deformation in affected areas
In basic terms, the board is no longer structurally sound. Even if the electrical connections still appear intact at first, the reliability of the board is compromised.
Within IPC A-600, delamination is clearly defined and illustrated to help inspectors determine whether a board meets the acceptability criteria or not. This is particularly important in industries where failure is not an option, such as aerospace and medical devices.
What Causes PCB Delamination?
PCB Delamination is rarely caused by just one thing. It is usually the result of stress being applied to the board at some point during manufacturing or later during assembly.
One of the most common causes of PCB delamination is excessive heat. During soldering or rework, the board is exposed to high temperatures. If the materials can’t handle that thermal stress, or if the heating process is not well controlled, the layers can begin to separate.
Moisture is another major factor. PCBs can absorb moisture from the environment over time. When the board is then heated, that moisture turns into vapour and expands, creating internal pressure. This can lead to blistering and eventually delamination. This is sometimes referred to as the “popcorn effect”.
Poor material quality or incorrect material selection can also play a role. Not all laminates perform the same under thermal stress. Lower quality materials or mismatched resin systems can be more prone to failure.
Manufacturing issues can also contribute. If the lamination process is not properly controlled, for example incorrect pressure, temperature or curing time, the bond between layers may already be weak before the board even reaches assembly.
Finally, it is also important to mention the risk of mechanical stresses. Bending, flexing, or improper handling can weaken the internal structure of the board and make it more susceptible to delamination later in the process.
How to Identify PCB Delamination
Spotting PCB delamination early can save a lot of time and cost further down the line. In many cases it is actually visible to the naked eye, especially when it presents as surface blistering or raised areas.
However, not all delamination is immediately obvious. Some defects occur internally and require more advanced inspection methods such as X-ray analysis or cross-sectioning.
This is where standards like IPC A-600 become incredibly useful. The standard provides visual examples and clear criteria, allowing inspectors to confidently assess whether a board should be accepted or rejected.
Having trained inspectors who understand these criteria is key. Without that knowledge, subtle signs of delamination can easily be missed.
How to Prevent PCB Delamination
The more consistent and well-managed your processes are, the lower the risk of defects like delamination.
One of the most effective preventative measures is proper moisture control. This includes storing PCBs in dry conditions, using moisture barrier bags and baking boards before assembly if needed.
Temperature control during soldering and rework is equally important. Using the correct thermal profiles and avoiding excessive or prolonged heat exposure can significantly reduce the risk.
Material selection also plays a big role. Choosing high-quality laminates that are suitable for the intended application ensures the board can withstand the required thermal and mechanical stresses.
Finally, handling practices should work to minimise unnecessary bending or stress during transport and assembly, to help maintain the integrity of the board.
The Role of IPC A-600 in Managing PCB Delamination
Understanding PCB delamination is one thing, but being able to assess it consistently across teams and projects is another.
That is where the IPC A-600 comes in. The standard provides a common language and visual reference for identifying defects in boards, including delamination. It outlines what is acceptable and what is not. As well as how to classify different levels of severity.
For companies involved in PCB inspection or procurement, training staff to this standard ensures a consistent and professional approach. At The Electronics Group we provide expert led training on the IPC A-600 standards. We can run the course at any of our 3 training centres or on-site to minimise disruption to your workflow.
See the full details for our IPC A-600 course here.
Final Thoughts on PCB Delamination
PCB delamination might seem like a small issue on the surface, but it can have serious consequences if it is ignored. From heat and moisture to material choice and handling, there are multiple factors that can contribute to it.
The good news is that with the right knowledge, processes and standards in place, it is largely preventable.
If your team is involved in inspecting or working with printed circuit boards, investing in training such as IPC A-600 can make a real difference. It gives you the tools to identify defects like delamination early and ultimately deliver more reliable products.
Get in touch with our team today to discuss your training needs.