X-ray imaging of silicon die within fully packaged semiconductor devices. Issue 2 (June 2021)

• Record Type: Journal Article
• Authors: Tanner, Brian K.; McNally, Patrick J.; Danilewsky, Andreas N.
• Is Part Of: Powder diffraction. Volume 36:Issue 2(2021)
• Page Start: 78
• Page End: 84
• Publication Date: 2021-06
• Subjects: X-ray diffraction imaging, -- semiconductor packaging, -- device warpage, -- synchrotron radiation, -- silicon; Powder metallurgy -- Periodicals; Materials -- Analysis -- Periodicals; 620.1127
• DOI: 10.1017/S088571562100021X
• Languages: English
• ISSNs: 0885-7156

Abstract

Abstract : X-ray diffraction imaging (XRDI) (topography) measurements of silicon die warpage within fully packaged commercial quad-flat no-lead devices are described. Using synchrotron radiation, it has been shown that the tilt of the lattice planes in the Analog Devices AD9253 die initially falls, but after 100 °C, it rises again. The twist across the die wafer falls linearly with an increase in temperature. At 200 °C, the tilt varies approximately linearly with position, that is, displacement varies quadratically along the die. The warpage is approximately reversible on cooling, suggesting that it has a simple paraboloidal form prior to encapsulation; the complex tilt and twisting result from the polymer setting process. Feasibility studies are reported, which demonstrate that a divergent beam and quasi-monochromatic radiation from a sealed X-ray tube can be used to perform warpage measurements by XRDI in the laboratory. Existing tools have limitations because of the geometry of the X-ray optics, resulting in applicability only to simple warpage structures. The necessary modifications required for use in situations of complex warpage, for example, in multiple die interconnected packages are specified.