Metallographic Inspection of Chip Package Cross-Sectioning
Metallographic inspection of chip package cross-sectioning is a core technology for package failure analysis and quality control. By preparing cross-section samples through precise directional cutting, grinding, polishing and chemical treatment, the internal interconnection structure is directly observed via microscopic technology. It is mainly used for: accurately evaluating the dimensions and coplanarity of interconnection units such as solder balls and copper pillars; inspecting the interfacial bonding state between chips and substrates to identify defects including delamination, voids and cracks; diagnosing process issues in electroplating, welding and other procedures; and locating failure points and analyzing the physical failure mechanisms caused by thermomechanical stress, electromigration, etc., after reliability testing or component failure. This technology provides intuitive, high-resolution cross-sectional information for the development of advanced packaging processes, defect troubleshooting and reliability assurance, and is therefore indispensable.
The traditional preparation scheme for cross-sectioning follows the principle of grinding step by step and inspecting in real time. It is recommended to use the TROJAN MTV03 High-Definition Stereo Microscope to observe the grinding status.
Specific Procedures:
● Use P400 grit sandpaper to quickly remove a portion of the material to approach the target position.
● Grind with P800 grit sandpaper and stop when the solder balls are exposed under observation.
● Precision grind with P1200 grit sandpaper to flatten the surface, polish all solder balls to the same plane and grind down to the half-diameter position of the solder balls.
● Use P2500 grit sandpaper for fine grinding to remove scratches from the previous step.
● Rough polishing with SC-JP polishing cloth + 1μm PD-WT polishing suspension.
● Final polishing with ZN-ZP polishing cloth + 50nm AO-W polishing suspension.
