Recently, semiconductor product (package or PKG) becomes smaller and thinner because of requirement of market. To realize the small PKG, 3D/2.5D structures are studied by many manufacturers. TSV (Through Silicon Via) and interposer substrate is famous as 3D/2.5D structure. These structures contain microscopic bumps to connect between silicon chips or between silicon chip and substrate. Diameter of these bumps reach 100 microns or several microns and height reach tens of microns. Total inspection on manufacturing process is important to prevent product failure and ensure quality. However it is difficult to apply total inspection to in-line process because bumps are too small to ensure inspection result and too many to keep throughput of manufacture process.
