Preparation Technique
Preparation of printed circuit board cross sections using a focused or broad beam of inert gas ions provides a deformation-free surface for microscopic evaluation. Microsection ion milling employs a stream of argon ions to sputter away material at the atomic scale, avoiding the mechanical smear typical of diamond saws and sandpaper. This procedure exposes the true boundary interfaces of plated copper, glass fibres, and epoxy resins without mechanical distortion.
Precise control of the beam voltage minimizes heating.
Material Interaction
Traditional polishing of soft metals such as copper often drags the metal over adjacent non-metallic regions, obscuring voids or microcracks. During the milling process, the high-energy ion beam uniformly removes different materials regardless of their hardness. This uniform removal prevents the creation of relief steps at the boundary between copper plating and the laminate substrate.
The treated area retains its structural integrity, allowing for accurate thickness measurements of sub-micron barrier layers. Protecting the sample from mechanical stress is essential for sub-micron analysis.
Analytical Benefit
Microscopic inspection of the milled surface under a scanning electron microscope reveals fine grain structures and intermetallic compounds. This high-resolution visualization allows inspectors to assess the quality of electroplated joints with confidence. Defect identification becomes reliable when surface smears are eliminated.
Clean boundaries ensure accurate diagnostic outcomes.
