Analytical Models for Viscous Squeeze Flow Trace Swim in Multilayer Buildups
Analytical squeeze flow models predict trace swim by calculating hydrodynamic drag and side-wall pressure differentials across fine copper features during lamination.
X-Ray Metrology
Dimensional Verification
Radiographic imaging provides the non-destructive observation of internal assembly geometries to confirm component alignment and structural integrity. By employing high-energy photons that penetrate opaque materials, x-ray metrology quantifies distances, volumes and offsets within complex electronic packages. Systems transmit beams through an assembly to detect variance in material density and atomic mass.
The resulting intensity data identifies internal features such as wire bond loops, solder joint voids and die attach coverage that remain hidden from optical inspection. Quantitative analysis follows the translation of these radiographic projections into volumetric representations.
Structural Capability
Automated stations integrate multi-axis motion stages and high-resolution detectors to capture precise coordinates for internal features. Software algorithms process these captures to measure BGA ball diameter or the registration between internal circuit layers. Variations in photon energy settings allow the isolation of specific materials, distinguishing light polymers from dense metallic contacts.
High-voltage power supplies generate the necessary electron flow to produce consistent imaging quality across varying package thicknesses. Stability within the detector array ensures that measurements remain repeatable over extended operational periods.
Process Compliance
Tight manufacturing tolerances demand accurate feedback loops to prevent latent field failures in high-density interconnection modules. Production lines rely upon these assessments to validate that thermal dissipation paths through vias maintain specified cross-sectional areas. Inspection results provide the baseline for iterative adjustments to solder paste deposition or reflow heating profiles.
Deviations from established dimensional targets trigger automatic rework or scrap procedures for affected production lots. Absolute measurement data confirms that internal assembly characteristics adhere to design intent under standardized environmental conditions.