Advanced Fault Isolation and Failure Analysis Techniques for Future Package Technologies

Evaluation of image reconstruction algorithms for non-destructive characterization of thermal interfaces

“…This test setup is similar to the one used in Ref. [2] where thermal imaging is used for qualitative detection of the flaws of electronic packages to optimize the assembly process. An electronic package such as the one considered in Ref.…”

“…An electronic package such as the one considered in Ref. [2] is similar to the system in Fig. 1, where layer-A represents the die and layer-C represents the lid of the package.…”

“…These defects must be identified so that the assembly process can be modified to achieve a high quality interface layer. Imaging and nondestructive characterization techniques such as computerized tomography (CT) using X-rays, or scanning acoustic microscopy (SAM) can be used during the assembly process development in order to identify the defects [2].…”

“…However, the reconstruction algorithms used for optical or acoustic imaging that relies on wave characteristic of the signal are not suitable for thermal tomography as the applied signal is transmitted by diffusion [11]. As a result thermal imaging has long been implemented for qualitative flaw detection that is used to complement other imaging techniques [2,12] and it has not been used for quantitative detection of electronic packages. Three alternative approaches can be adopted to use IR imaging for quantitative imaging using thermal tomography: 1) new algorithms can be developed, 2) the problem is adjusted so that it can be formulated similar to wave propagation like phenomena where existing reconstruction algorithms can be used for solution, 3) existing image reconstruction algorithms used for diffuse optical tomography where system is prone to diffusion can be adapted.…”

Detection of solder bump defects on a flip chip using vibration analysis

“…Due to the structure of a flip chip, the inner solder bumps are difficult to observe, which makes optical inspection almost infeasible. In SAM inspection, a coupling medium between the transducer and the specimen is required for impedance matching and coupling the acoustic waves into the specimen [7,8]. However, it is generally inappropriate to immerse the electronic devices into the coupling medium such as deionized water, oil, and Vaseline.…”