Three Dimensional Voxel Scale Calibration Methods for Automated Micro-CT Inspection
Calibrating micro-CT voxel scale with certified ball-bar phantoms bounds geometric magnification drift and ensures repeatable automated void sizing.
BGA Micro-Bump Metrology
Measurement Specification
Optical and tactile sensors quantify the geometric integrity of spherical solder contacts on high density semiconductor packages. Bga micro-bump metrology confirms dimensions including coplanarity, diameter, and positional tolerance relative to the package substrate interface. Accurate measurement prevents shorts or open circuits during reflow onto a printed circuit board.
Operational Protocol
Automated inspection platforms acquire three dimensional data from the array to isolate deviation from the design specification. Software algorithms calculate the volumetric displacement and sphericity of individual bumps to identify latent defects that impede electrical connectivity. Probes move across the grid to map surface topography with resolution reaching the sub-micron level.
Variation detected during this process provides information on solder paste deposition accuracy or stencil wear in the manufacturing line. Statistical monitoring of the bump height distribution maintains process stability before the components arrive at the assembly stage.
Acceptance Boundary
Yield loss results from bump deformation or oxidation that escapes detection during initial fabrication. Standards define the permissible limit for ball height variance to avoid uneven contact pressure across the array. Excessively small bumps fail to bridge the gap to the landing pad, while oversized balls threaten to short against adjacent terminals.
Rigorous adherence to these tolerances dictates the functional reliability of the finished electronic assembly.