Title :
Conductive microbead detection by Helmholtz coil technique with SV-GMR sensor
Author :
Somsak, T. ; Chomsuwan, K. ; Yamada, S. ; Iwahara, M. ; Mukhopadhyay, S.C.
Author_Institution :
Kanazawa Univ., Japan
Abstract :
We present an eddy-current test (ECT) method for detecting conductive microbeads on a nonconductive substrate. A Helmholtz coil is used to generate an exciting magnetic field. The magnetic fields, generated by eddy-currents in a Pb-Sn microbead, are detected by a spin-valve giant magnetoresistive (SV-GMR) sensor. The experimental results are compared to an analytical solution for the magnetic field over the microbead. Early results for the detection of a grid of microbeads are also presented.
Keywords :
Helmholtz equations; eddy current testing; giant magnetoresistance; lead alloys; magnetic sensors; spin valves; tin alloys; ECT method; Helmholtz coil technique; PbSn; SV-GMR sensor; conductive microbead detection; eddy-current test method; exciting magnetic field; nonconductive substrate; spin-valve giant magnetoresistive; Coils; Electrical capacitance tomography; Electronics packaging; Giant magnetoresistance; Integrated circuit packaging; Magnetic sensors; Object detection; Sensor arrays; Soldering; Testing; Helmholtz coil.; conductive microbead; eddy-current testing; spin-valve giant magnetoresistance;
Conference_Titel :
Electronic Design, Test and Applications, 2006. DELTA 2006. Third IEEE International Workshop on
Print_ISBN :
0-7695-2500-8
DOI :
10.1109/DELTA.2006.25
