PBGA Delaminations

Pictured

Time Domain Imaging (TDI)™
Utilizes an echo (amplitude & polarity) arrival ‘time’ as a reference, such as standard A-Scan, B-Scan and C-Mode type images.

PBGA Delaminations

PBGA Delaminations, Through Transmission - Application Note 1009

PBGA Delaminations

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.

Result

  • 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.