Microsection Coupon Report – Ensuring your PCB are reliable and robust
One of the most important steps we perform as part of our manufacturing process is the micro-sectional coupon report. IPC-A-600 has two sections on inspection criteria (Externally Observable Characteristics and Internally Observable Characteristics. This method deals with IPC Class-1/2/3 for Internally Observable Characteristics. With this inspection procedure, we can inspect internal view of dielectric materials, conductive pattern and plated through holes quality and make sure there are no PCB defects.
It is a multi-step process where tests are performed on a sample from the production run for the same project. We use metallurgical microscope, grinders to evaluate the cross-section. Here is a preview of the steps we follow to ensure your PCB is high quality and in accordance to your Gerber files.
- Select test coupons and cut out close to ¾” inch square
- These coupons are securely placed inside a mounting cup filled with liquid epoxy then let it harden
- The hardened sample then goes through a series of finely grinded and polished to form a smooth surface finish so that the internal parts of PCB are exposed for microscope inspection and measurement.
- The Micro section coupon is the placed under the Metallurgical Microscope which connected to a computer and inspection for quality and defects.
- We also can capture the image of defect for the report. The dimension of defect could be measured as well.
- The analysis will evaluate:
- Hole ( barrel ) wall structure and quality
- Quality of the copper plating and plating thickness
- Voids
- De-lamination
- Copper cracks
- Nail heading
- Separation
- Annular ring
- Wicking
- Resin recession
- Final finish thickness
