In this X-ray University video, we show how 3D X-ray inspection and computed tomography (CT) make PCB inspections more effective. Overlapping components can obscure defects in traditional 2D X-rays, but CT solves this issue by providing a clear, layered view of your board.
The Challenge: Overlapping Components
When inspecting PCBs, components like Ball Grid Arrays (BGAs) can overlap. This overlap makes it difficult to see defects like voids or shorts. In this example, the BGA balls from both sides of the PCB overlap in the X-ray, preventing clear identification of which balls are from the top or bottom layers.
Enter 2.5D X-Ray Inspection
One option to handle this is 2.5D X-ray inspection, where we tilt the board to separate the layers. This method helps with larger BGA balls, but it’s still challenging for smaller components.
The Best Solution: Computed Tomography (CT)
Computed tomography (CT) provides the ultimate solution. With CT, you can easily separate the top and bottom PCB layers. It also lets you slice through the layers, analyzing defects with precision. CT allows you to identify exactly where voids or other issues occur, offering more detail than 2D or 2.5D X-rays.
CT for Better Defect Detection
Using CT, you can inspect each layer of the PCB. In our example, CT clearly shows a void in the top BGA, as well as its exact location. We can also analyze the BGA’s position relative to the PCB pad, giving us valuable insights.
CT helps you inspect layer by layer, down to the bare die and wire bonds, ensuring that no defect is missed.
