Speakers
Description
The vertex detector (VXD) for the Belle-II experiment, at the Super-KEKB in Japan, measures precisely information of vertexing and tracking. The VXD consists of a pixel detector (PXD) and a silicon vertex detector (SVD) with two and four layers, respectively, so that operates under a high luminosity environment of the Belle-II experiment. For the SVD, a novel chip-on-sensor concept, called “Origami”, is developed to reduce the multiple Coulomb scattering and capacitive noise. A wire-bonding and assembly procedures for the outermost layer of the SVD have been studied. A wire-bonding study especially for the Origami module has been performed. As changing the bonding parameters, we measure pull-forces to break the wires by pulling them and observe shape types of broken wires and bond foot prints. In addition, an issue on position precision of a tilted DSSD is found, and a shim method has been employed and studied to improve mechanical precision of the DSSD. In this paper, we present the results of wire-bonding study and introduce the shim method to solve the problem of the tilted sensor during the assembly procedures.
