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 microsectional 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.
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
- Copper cracks
- Nail heading
- Annular ring
- Resin recession
- Final finish thickness