Measurement of Deformation and Strain in First Level C4 Interconnect and Stacked Die using Optical Digital Image Correlation

Abstract

In this paper we demonstrate the application of Digital Image Correlation (DIC) to the measurement of nanometer scale deformation in advanced packaging including flip chip and stacked integrated circuit dies. The application of DIC is shown to provide critical strain data which is useful for lifetime prediction of advanced packaging solutions. We show U and V deformation field contour (fringe) maps, analogous to Moiré interferometry results, measured by digital image correlation technology, without the need for applied phase gratings. Shear and normal strain contour maps are also shown superimposed transparently on micrograph images.Novel enhancements of the digital image correlation technique are described with particular emphasis on the refinement of the technique for application to electronics package measurement, and on software development. The application of levels of intelligent, goodness-of-data based corrections, for the measurement of nanometre scale deformation, and rigid body motion corrections are discussed. The technique has been further refined to obtain measurements from entire IC package structures which include such thermally and optically distinct materials as underfill and copper layers.Finally, failure analysis and modeling, such as NorrisLandzberg or Coffin-Manson models, is discussed in relation to the results exposed in this paper.

Effect of Alloy Composition and Aging on the Survivability of Leadfree Solders in High Temperature Vibration in Automotive Environments

“…The technique involves the application of speckle pattern on the surface of the printed circuit board assembly and tracking geometric points on the speckle patterned surface before and after loading and using them to compute both in-plane as well as out-of-plane deformations in the structures. [Zhou 2001,Amodio 2003, Srinivasan 2005, Kehoe 2006, Lall 2007c, 2008c. Figure 17 shows the principle of DIC in a three-dimensional case.…”

Board trace fatigue models and design guidelines for electronics under shock-impact

“…The technique involves the application of speckle pattern on the surface of the printed circuit board assembly and tracking a geometric point on the speckle patterned surface before and after loading and using it to compute both in-plane as well as out-of-plane deformations in the structures. Displacement field quantities are obtained by tracking a geometric point before and after deformation [Zhou 2001, Amodio 2003, Srinivasan 2005, Kehoe 2006c , 2008 ]. The tracking is achieved using digital image processing of speckle pattern on the specimen surface.…”

Damage Progression Using Speckle‐Correlation and High‐Speed Imaging for Survivability of Leadfree Packaging Under Shock

“…DIC has been used for shock‐deformation in electronic assemblies by tracking the speckle pattern in small regions called subsets during a transient event namely drop – impact in conjunction with high speed cameras. DIC is an optical method to measure full field deformation on the surface of an object based on tracking a geometric point before and after deformation and using it to calculate the displacement field [34, 36, 43, 45]. The undeformed and deformed images are called the original image and deformed image respectively.…”

“…DIC enables full field strain and displacement measurement during a transient event namely shock and drop‐impact in comparison to a gage which measures strain only at localised points on the specimen. DIC has been used in electronic industry to study dynamic response of printed circuit assemblies of mobile phones [27–29], material characterisation [30–33], stresses and strain in flip‐chip die under thermal loading [34], fracture toughness of underfill/chip interface due to temperature and ageing conditions [35], stresses in solder interconnects of BGA packages under thermal loading [36–42], and material characterisation under thermal loading [43, 44].…”