Analyze a 1.0 mm2 area of a circuit board using a 10 µm diameter beam.
Considerations
Voids within a sample are checked using transmission X-ray imaging with a 10 µm diameter X-ray beam.
From the XRF data measured for tin (Sn), copper (Cu) and bromine (Br) images as well as RGB composite images, it was possible to verify the presence of copper ion migration on the circuit board. The ends of the copper pads were not covered by solder, leaving the copper exposed. It could be surmised that this along with the effects of residual flux and residual cleaning solution caused the migration.
Test Sample Provided by Dr Suganuma, Osaka University
Observation of Internal Structure Using Transmission Images
The 10 µm diameter beam can be used, for example, to observe transmission images of voids (air bubbles) typically sized in the range 25 to 75 µm.
Ion Migration Analysis Using X-ray Fluorescence
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