Open AccessHigh resolution line scan interferometer for solder ball inspection using a visible supercontinuum source
Author(s) -
Madhav Kumar,
M. N. Islam,
Fred L. Terry,
Carl C. Aleksoff,
Douglas Davidson
Publication year - 2010
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.18.022471
Subject(s) - optics , supercontinuum , interferometry , materials science , michelson interferometer , ball (mathematics) , white light interferometry , surface finish , surface roughness , astronomical interferometer , fourier transform , physics , wavelength , composite material , quantum mechanics , photonic crystal fiber , mathematical analysis , mathematics
A line scan interferometer, which comprises a visible supercontinuum source coupled to Fourier domain Michelson interferometer, is used to obtain 3D images of ~300 μm high solder balls on a semiconductor die with 125 nm axial and 15 μm lateral resolution. The ability to measure curved surfaces enables the determination of solder ball shape defects in addition to ball height. We show that the maximum measurable angular tilt from the sample surface normal for a given source power depends on the surface roughness of the sample. As an example, we demonstrate height measurement over +/-20 degrees from the normal on the solder balls and over +/-60 degrees on a rough steel ball bearing sample.