X-ray inspection can reveal internal features that ordinary optical inspection cannot see, including aspects of hidden solder joints. The result depends on the imaging method, viewing geometry, resolution and interpretation. Define the defect and acceptance question before choosing the inspection approach.
Identify the hidden features that matter
List BGA, bottom-terminated and other obscured joints that need evaluation. Specify the conditions of concern, such as bridging, missing connections or void-related criteria where applicable. A general request for X-ray does not tell the operator which features and limits control acceptance.
Choose suitable imaging and views
Two-dimensional projections can overlap structures from different depths. Oblique views or other imaging approaches may be needed for particular questions. Confirm that the equipment and inspection plan can distinguish the relevant features on the actual board construction.
Interpret images with the process context
Compare the image with the package, land pattern and soldering process. Some defects require corroborating electrical tests or further analysis. Do not infer complete product function from an image of apparently acceptable joints.
Specify coverage and records
Agree whether inspection covers all assemblies, selected packages or an approved sampling plan. Define image retention, board identification, review responsibility and handling of uncertain results. Changes to package geometry or process should trigger review of the inspection program.
Release checklist
- Name the packages and defects to inspect.
- Agree imaging method and acceptance criteria.
- Define coverage, sampling and escalation.
- Combine imaging with appropriate electrical and functional tests.