Cross-Section Analysis Services | NEXTY Electronics Quality & Analysis Support

Flat milling is mainly used to remove scratches or rounding left after mirror finishing by mechanical cross-section polishing.
Its advantage is the wide processing range (approximately Φ30 mm).
However, the processing depth is shallow (a few μm to about 10 μm), so if deep scratches or rounding remain after mirror finishing, flat milling alone may not completely remove them.

Cross-section milling removes material using an ion beam starting approximately 100–200 μm before the target area, so the intended surface does not receive direct stress.
This allows for a smooth finish even on materials that are prone to deformation or fracture under stress.
However, the processing range is relatively narrow (about 1–5 mm), making cross-section milling more limited compared to flat milling.

Cross-section milling removes material using an ion beam starting approximately 100–200 μm before the target area, so the intended surface does not receive direct stress.
This enables a smooth finish even on materials that are easily deformed or damaged by stress.
On the other hand, the processing range is limited to about 1–5 mm, which is narrower than flat milling.

PCB Board – Flat Milling of Pb-Free Solder Alloy Layer

Mechanical cross-section polishing alone does not clearly reveal the shape of the Cu-Sn alloy region. By applying flat milling, the shape becomes distinct, allowing accurate measurement of the alloy layer thickness.

Cross-Section Milling – Au Bonding / Al Pad Joint Cross-Section

When observing the bonding joint in cross-section, mechanical polishing often causes the Al pad to break due to stress, making it difficult to obtain a clean cross-section.
With cross-section milling, the sample is removed using only an ion beam without applying mechanical stress, allowing the joint to be observed without damaging the Al pad.