PBGA Delaminations, Through Transmission - Application Note 1009
Sample & Method
These 4 plastic BGA packages were imaged simultaneously by the THRU-Scan technique at 15 MHz. THRU-Scan uses a second transducer beneath the sample to collect ultrasound that has traveled through the entire thickness of the sample.
- All four BGA packages have very similar large circular defects. These defects are likely delaminations at the molding compound to substrate level and/or within the substrate.
- In three of the packages, there are small areas within the large defect region that are not delaminated. The solder bumps are visible in these and other areas exhibiting good transmission.
- The dark spot near the lower left is the pin one marker.