PCB Microsection Analysis: Cutting Open Boards to Find Hidden Failures
WHAT THIS VIDEO COVERS
This video provides a practical demonstration of PCB microsection analysis - a destructive testing method where finished circuit boards are cut, mounted, polished, and examined under high-magnification microscopes to evaluate internal quality.
Even when a PCB looks perfect externally, critical internal defects can compromise performance. The analysis focuses on key areas including copper plating thickness in drilled holes, voids in hole walls, cracks, delamination between layers, and registration accuracy of the multilayer stack-up.
These microscopic flaws can lead to premature failure through issues like poor conductivity, thermal stress, or mechanical weakness. Microsection analysis is a cornerstone of quality control in high-reliability PCB fabrication, helping manufacturers verify plating quality, lamination integrity, and overall process consistency.
This inspection method is particularly vital for demanding applications such as aerospace PCBs, medical device PCBs, and automotive electronics, where product failure is not an option. Understanding microsection results enables better design decisions for HDI PCBs, multilayer boards, and high TG applications.
The video translates complex quality control processes into clear visual insights that help OEM engineers and procurement teams evaluate supplier capabilities and reduce field failure risks.
KEY HIGHLIGHTS
- Hidden Defects Revealed: Microsection analysis exposes issues like thin copper plating, voids in via walls, cracks, and delamination that standard electrical testing often misses.
- Multilayer Integrity: Examines layer registration, prepreg bonding, and copper-to-resin interfaces critical for reliable high-layer count PCBs.
- Reliability Assurance: Essential quality control step for high-reliability applications in aerospace, medical, and automotive electronics.
FAQ
Q1: What defects does PCB microsection analysis typically detect?
A1: It identifies thin or uneven copper plating in holes, voids, cracks, resin delamination, and layer misalignment - defects that can cause early field failures even if the board passes functional testing.
Q2: Why is microsection analysis important for high-reliability PCBs?
A2: It provides direct visual proof of internal quality that cannot be verified through non-destructive methods, making it a standard requirement for aerospace, medical, and automotive projects where reliability is critical.
Q3: When should a project require microsection analysis?
A3: Microsection analysis is recommended for Class 2/Class 3 boards, HDI designs, high-layer count PCBs, or any application with extreme thermal, mechanical, or environmental demands.
Look at this.We cut open a PCB to inspect what normally stays hidden.
This tiny cross-section reveals whether a PCB will survive… or fail.
Today, we're taking you inside the Aivon factory to show you exactly how PCB cross-section analysis — also called microsectioning — is performed.
PCB cross-section analysis is a destructive testing method used to evaluate the internal structural quality of printed circuit boards.
It reveals internal structures such as copper plating thickness, hole wall quality, and layer alignment — as well as hidden defects like voids, cracks, resin smear, and delamination.
This process is critical for quality control, failure analysis, and ensuring the PCB meets IPC quality requirements.
In high-reliability industries like automotive, medical, aerospace, and telecommunications,it's not optional — it's essential.
Here's how it's done step by step.
First, we carefully cut a test coupon or target section from the production panel using a precision saw. The sample must capture the exact features we want to inspect, usually plated through holes.
Next, the sample is placed into a mold and encapsulated with epoxy resin. This mounting process provides solid support for later grinding.
Once cured, we begin grinding the sample using progressively finer abrasives. We grind carefully until we reach the center of the hole or the exact plane we need to examine.
Once polishing is complete, the sample is examined under an optical microscope.
Here, we measure the copper thickness inside the plated through hole to verify whether it meets IPC requirements.
We also examine the hole wall for defects such as voids, cracks, uneven plating, resin smear, or layer separation.
Even tiny defects at this scale can lead to electrical failure, thermal stress damage, or long-term reliability issues.
On the left is a high-quality microsection:
Uniform copper plating,
clean hole walls,
and accurate layer registration.
On the right is a failure case.
Notice the thin copper area and the void inside the plating layer.
Defects like these can weaken electrical connections and eventually lead to intermittent failure in the field.
Microsection analysis allows engineers to fine-tune the manufacturing process and prevent costly field failures.
In PCB manufacturing, reliability starts long before the product is assembled.
It starts here — under the microscope.
