Authors:
YangSub Park
;
KilBum Kang
;
Sangyun Yun
and
SeongSoo Kim
Affiliation:
Advanced Technology Inc, Korea, Republic of
Keyword(s):
BLT, Bond Line Thickness, Si Thickness, TSV.
Related
Ontology
Subjects/Areas/Topics:
Applications
;
Computer Vision, Visualization and Computer Graphics
;
Image Understanding
;
Pattern Recognition
Abstract:
Today, many semiconductor products are manufactured through the TSV process. At this time, It is important to manage the Bond Line Thickness because all of the stacked dies must be discarded due to a single contact failure. If we can measure the thickness of the silicon, the BLT in the wafer level package process can be estimated. In this paper, we propose a method to measure the thickness of silicon by using infrared ray. We designed the infrared light source to select the path of the incident light to the objective lens. And this optical system has a characteristic of moving in the opposite direction according to a change in height. By using this optical system, it is possible to calculate the correct in-focus position. By doing this, we present a method to measure BLT by measuring the distance between the top and bottom of Si surface.