Investigation of defects in fully packaged devices

Investigation of Defects in Fully Packaged Devices
- Integrated Circuits -
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LIT can be used to investigate fully packaged devices since thermal waves can propagate through optically opaque materials like mold compounds. Using a lock-in frequency of 1 to 25 Hz allows the observation of hot spots through 100-400 µm package material with a lateral spot size of a few tens to hundred µm. Figure 4902 shows an example of using LIT for defect localization in a fully-packaged device. A defect causing a short between these two Au bond wires had been detected.

LIT can be used to investigate fully packaged devices

Figure 4902. (a) Picture of the fully packaged device, (b) first LIT measurements, (c, d) mechanical grinding of package material allow defect allocation between Au bond wires), (e) second LIT measurement of the grinded package, and a) optical image of a cross section showing a metal splinter creating a short between two Au bond wires. [1]

[1] Paiboon Tangyunyong and Christian Schmidt, Thermal Defect Detection Techniques, Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.

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