3d x-ray inspection

3D Automated X-Ray Inspection (AXI) is a non-destructive testing method that uses X-ray imaging combined with computed tomography (CT) or laminography to create highly detailed, 3D cross-sectional slices of a printed circuit board. This technology allows quality engineers to inspect the structural integrity of solder joints that are hidden completely from view.

Traditional 2D X-ray creates a flat, top-down image. On double-sided boards, components on the top and bottom overlap, creating confusing shadows that make it difficult to isolate faults. 3D X-ray captures multiple angled images and reconstructs geometric slices, allowing us to isolate specific layers and inspect complex assemblies without overlapping interference.

All solder connections on a Ball Grid Array (BGA) or Quad Flat No-Lead (QFN) component are located entirely underneath the package. Because they are physically hidden, it is impossible to verify them using standard optical cameras or human inspection. X-ray is the only non-destructive way to guarantee these connections are solid and free of shorts.

Our 3D AXI systems excel at finding issues that escape visible inspection, including solder voids, bridging (shorts) between hidden pins, missing solder balls, insufficient wetting, open connections, and complex "head-in-pillow" (HiP) defects on advanced surface mount packages.

Voiding occurs when flux gas bubbles get trapped inside the molten solder during the reflow process. While minor voiding is common, excessive voiding weakens both the mechanical and thermal integrity of the joint. 3D AXI automatically calculates the exact volumetric percentage of voids, ensuring it complies with strict IPC standards (typically keeping voids under 25-30%).

HiP is a notorious hidden defect where a BGA solder ball rests in the solder paste but fails to fully coalesce and form a true metallurgical bond—resembling a head resting on a pillow. It often passes initial electrical testing but fails in the field due to mechanical stress. 3D X-Ray provides the distinct slice-level detail needed to detect this separation line.

Yes. For high-reliability and IPC Class III applications, it is crucial to verify that the solder has properly flowed completely through the plated barrel. 3D X-ray can accurately measure the volumetric barrel fill percentage (verifying it meets the required 75%+ standard) without having to physically cut the board open for microsectioning.

They are complementary technologies. AOI uses visible light cameras to check for surface-level defects like missing parts, skewed placement, and the visual quality of exposed solder fillets. AXI uses radiation to penetrate the physical materials, allowing us to inspect the internal geometry, thickness, and hidden structural integrity of the joints beneath the surface.

Generally, no. While massive doses of radiation can affect sensitive components like specialized memory chips or image sensors, our automated 3D AXI systems are programmed with optimized exposure times and controlled energy levels (kV/µA). This provides high-resolution imaging while remaining well within the safe dosage limits for standard electronics.

This depends entirely on your project's compliance requirements. For mission-critical aerospace, medical, or defense boards, 100% AXI inspection is often mandatory. For standard commercial electronics, we typically perform 3D AXI on "first-article" boards to validate the oven reflow profile, followed by strict statistical batch sampling during volume production.