Reconstructed Geometry
Radiographic inspection technique provides high-resolution volumetric data of planar objects by scanning at oblique angles. During surface-mount assembly, the use of 3d computed laminography allows for the visualization of individual solder joints within a dense grid array without interference from components on the opposite side of the board. The system moves the X-ray source and detector in synchronous paths to create a focal plane where specific features become sharp while others blur.
This method defines the internal structure of multilayer assemblies where traditional orthographic X-rays would suffer from overlapping images. Precise calibration of the rotational axis ensures that the synthetic cross-sections remain consistent across the entire field of view.
Inspection Capability
Defect detection relies on the ability to isolate horizontal slices of a printed circuit board. Using 3d computed laminography, technicians identify voiding in bottom-terminated components and head-in-pillow defects in ball grid arrays. The process captures data from multiple perspectives to reconstruct the solder volume and shape.
Quantitative analysis of the resulting imagery confirms compliance with IPC-A-610 standards for solder wetting and fill.
Mechanical Operation
Motion control hardware determines the clarity of the reconstructed slices. While computed tomography rotates a sample, 3d computed laminography keeps the board stationary or moves it in a flat plane to maintain alignment with SMT production lines. This mechanical constraint limits the reconstruction to a specific depth of field.
High-speed cameras and flat-panel detectors translate these X-ray photons into digital data for algorithmic processing.
