Patent ID: 7688078
Filing Date: 2010-03-30
Classification: G01B,G01N

Abstract:
1. A system for counting the number of layers of a multilayer object, comprising: an oscillation unit for oscillating an electromagnetic wave having a frequency in a range from 30 GHz to 100 THz to irradiate either a top surface or a bottom surface of the multilayer object; a first reception unit for receiving the electromagnetic wave having pulses reflected at interfaces of the layers of the multilayer object; a first processing unit for counting the number of pulses of the electromagnetic wave received by the first reception unit, and counting the number of layers of the multilayer object on the basis of the counted number of pulses; a second reception unit for receiving the electromagnetic wave oscillated by said oscillation unit and transmitted through the multilayer object; and a second processing unit for counting the number of layers of the multilayer object on the basis of a delay time detected by using the transmitted electromagnetic wave, wherein the number of layers counted by the first processing unit is compared with the number of layers counted by the second processing unit to count the number of layers of the multilayer object.