Testing Background:

Printed circuit boards (PCBs) serve as the core structural components of electronic devices, with the integrity of their microscopic internal structures directly determining device reliability. Common defects such as microcracks, hole wall tears, and plating voids are typically micrometer-scale, concealed within the substrate or hole walls. Conventional inspection methods struggle to accurately identify these flaws, yet they can trigger critical failures like signal anomalies and short circuits.

Solution: POMEAS Metallographic Microscope

Metallographic microscopes, with their high magnification capabilities ranging from 500X to 1000X, clearly reveal the morphology and distribution of various microscopic defects, making them indispensable core equipment in PCB quality inspection.

For resin microcracks, high magnification clearly reveals linear dark fissures measuring 1-5 micrometers, precisely identifying their initiation points and propagation directions—a level of localization and analysis unattainable through low magnification or ultrasonic testing. For hole wall tears and drilling burrs, 1000X magnification clearly reveals the jagged morphology of torn glass fibers, enabling identification of burr material and dimensions. This provides direct evidence for optimizing drilling processes, outperforming low-magnification optical observation and X-ray inspection.

During chemical copper plating and electroplating processes, metallographic microscopes can precisely capture latent defects such as discontinuities and pinholes in the copper deposit layer, as well as circular voids measuring 2–8 micrometers within the plating layer. They can also correlate these defects with their root causes (e.g., aged copper plating solution, uneven current distribution). Conventional conductivity testing or ultrasonic scanning can only assess macro-level compliance, failing to visualize or trace microscopic defects.