- - The ISFET-probe fabrication and measuring-system design technology for electrostatic discharge protection of the ISFET sensor

摘要

PURPOSE: A producing method of an ISFET(Ion Sensitive Field Effect Transistor)-probe and a designing method of circuit for a main body of a measuring machine are provided to prevent an ISFET sensor from damaging with static electricity. CONSTITUTION: An ISFET(Ion Sensitive Field Effect Transistor)-probe comprises an ISFET sensor(101), a conductive shaft(102), a knob(103) of the probe, a conductive metal ring(104), a signal connecting line(105) of the sensor and a connecting line(106) for inducing static electricity. A main body of a measuring machine composes a circuit with first and second diodes(107,108), a VCC(109) and a VEE(110). Thereby, static electricity of the ISFET sensor is discharged through a channel of the conductive shaft, the conductive metal ring and a human body. A sensing layer of the ISFET is protected by discharging static electricity through the conductive shaft, the conductive metal ring, a connecting line for inducing static electricity, first and second diodes, the VCC and the VEE.