The quality of circuit boards, troubleshooting, and process improvement all require microsectioning for observation, research, and judgment. This is crucial for ensuring correctness and making informed decisions. While general production lines use quality monitoring or control for shipment, the rushed and inexperienced approach can only reveal up to 60-70% of the truth. For thorough problem-solving and quality control, precise and undamaging micro-slices are essential.
Classification:
Anatomically destructive sectioning can be categorized into:
- General Slicing (Microslicing) for vertical or horizontal sections in the through-hole area.
- Cut Holes for observing the original surface condition of half of the hole wall.
- Oblique Section (45° or 30°) for observing multi-layer board surface or through hole areas.
Production Skills:
Sampling:
- Use a special cutting die or shearing machine to sample from any part of the board.
- Be careful not to deform through holes by tension and avoid the edge of the hole.
- Use a diamond saw blade to cut the desired sample to reduce mechanical stress.
Sealing: - Fill the through hole with sealant to fix and clamp the wall for observation.
- Use a sealant with good transparency, high hardness, and minimal air bubbles.
- Formal method involves using a rolling spring clamp and pouring sealant into a cylindrical blue rubber mold for easy demolding.
- Other methods include using mold release agent, rubber powder in a hot pressing mold, Nelson-Zimmer method, ready-made acrylic mold, applying colloid on PE paper, and direct filling with glue at the hole with bamboo sticks.
Conclusion:
Careful microsectioning is essential for quality control and problem-solving, and requires precision in sampling and sealing methods to obtain clear and visible micro-slices without causing damage or misjudgment.
