Ball grid arrays are another type of hidden joint device commonly used on PCBs.
3D AXI can detect defects on hidden joints, and can be placed inline, making it feasible for volume manufacturers.
Bingo--you've got a substantial, strong, hidden joint
I am surprised PTH joints do not come up in conversations more frequently because they are obviously hidden joints
, which by their nature have limited access, are the main driver for using automated x-ray inspection.
They include area array packages and other component technologies with hidden joints
as well as heat sinks and RF shields.
To round out that awesome configuration, let's add AXI at the backend to reveal those nasty hidden joints
AXI detects voids, solder quality defects, hidden joints
, and numerous [V.sub.CC] and GND pins that are invisible to both AOI and ICT.
Joints and features hidden under components or leads are made visible; X-ray alone can view the hidden joints
of mounted BGAs, CCGAs, and CSPs.
cannot be inspected with AOI because this technique relies on visible line of sight to the joint.
This includes offline test equipment as well as x-ray systems, which are designed to take a closer look at solder joints and analyze their structure--including hidden joints
(BGA, CSP)--and report on voids inside the joint.