公开(公告)号：JP2000205812A

公开(公告)日：2000-07-28

申请号：JP35691899

申请日：1999-12-16

Applicant: ST MICROELECTRONICS INC

Inventor： ARNAUD EVE LUPERT ,  RAYNAL FREDERIC DENIS

IPC: H01L27/04 ,  G01B7/34 ,  G06K9/00 ,  H01L21/822

Abstract: PROBLEM TO BE SOLVED: To improve protection of a fingerprint sensor from electrostatic discharge by forming a composite insulating layer with dielectric regions between and on a plurality of conductive plates to isolate the conductive plates and protecting them from damage. SOLUTION: The conductive plates 10 and 12 of a single capacitance coupling sensor cell 3 have approximately the same surface area. The inside plate 12 acts as a half of one electrode of the sensor 3, and the outside plate 10 acts as an opposing capacitor electrode as a complementary half of the same and one capacitor electrode to interact with an object 22 such as a finger. Insulating layers 16 with dielectric regions are provided between the plates 10 and 12 and a discharging pad 40 provided on their surfaces. The degree of conductivity of the discharging pad 40 is sufficient for transferring electrostatic charge which occurs on the surfaces of the sensor cell 3 in the insulating layers 16 and the discharging pad 40 for protecting the electronic components of the sensor cell 3.