Noise-proof semiconductor device having a Hall effect element
A noise-proof, integrated semiconductor current detector is disclosed which has formed in a semiconductor substrate a Hall generator for providing a Hall voltage in proportion to the strength of a magnetic field applied, a control current supply circuit for delivering a control current to the Hall generator, and a Hall voltage output circuit for putting out the Hall voltage for detection or measurement. The Hall generator, control current supply circuit, and Hall voltage output circuit are all exposed at one of the pair of opposite major surfaces of the semiconductor substrate. A current-path conductor is attached to this one major surface of the substrate via insulating layers for carrying a current to be detected. A shielding layer of highly electroconductive material is interposed between the current-path conductor and the substrate for protecting all of the Hall generator, control current supply circuit, and Hall voltage output circuit from noise from the current-path conductor as well as from external disturbances.
1. A semiconductor device having a Hall effect element and at least one other active component that is not a Hall effect element, comprising:
(a) a semiconductor substrate having a pair of opposite major surfaces and having the Hall effect element and said other active component formed therein, the Hall effect element and said other active component being exposed in part at one of the major surfaces of the semiconductor substrate;
(b) an electrically insulating layer formed on said one major surface of the semiconductor substrate; and
(c) a shielding layer formed on the insulating layer in overlying relationship to both the Hall effect element and said other active component.
2. A semiconductor device as defined in claim 1 , further comprising:
(a) a second electrically insulating layer disposed on said shielding layer; and
(b) a current-path conductor disposed on the second insulating layer and so positioned thereon as to cause a magnetic field to act on the Hall effect element with strength in proportion to the magnitude of a current flowing through the current-path conductor.
3. A semiconductor device as defined in claim 1 , wherein the shielding layer is of electroconductive material and is grounded.
4. A semiconductor device as defined in claim 1 , further comprising a metal-made baseplate attached to the other major surface of the semiconductor substrate for protecting the Hall effect element and said other active component from noise in cooperation with the shielding layer.
5. A noise-proof, integrated semiconductor current detector comprising:
(a) a semiconductor substrate having a pair of opposite major surfaces;
(b) a Hall effect element formed in the semiconductor substrate for providing a voltage proportional to the strength of a magnetic field applied, the Hall effect element being exposed at one of the pair of major surfaces of the semiconductor substrate;
(c) a control current supply circuit formed in the semiconductor substrate and electrically connected to the Hall effect element for delivering a control current thereto, the control current supply circuit being exposed at said one major surface of the semiconductor substrate;
(d) a Hall voltage output circuit formed in the semiconductor substrate and electrically connected to the Hall effect element for putting out the voltage generated by the Hall effect element, the Hall voltage output circuit being exposed at said one major surface of the semiconductor substrate;
(e) an electrically insulating layer formed on said one major surface of the semiconductor substrate; and
(f) a shielding layer formed on the insulating layer in overlying relationship to both the Hall effect element, the control current supply circuit and the Hall voltage output circuit.
6. A noise-proof, integrated semiconductor current detector as defined in claim 5 , further comprising:
(a) a second electrically insulating layer disposed on said shielding layer; and
(b) a current-path conductor disposed on the second insulating layer and extending along the Hall effect element for causing the same to generate a voltage in proportion to the magnitude of a current flowing through the current-path conductor.
7. A noise-proof, integrated semiconductor current detector as defined in claim 5 , further comprising a metal-made baseplate attached to the other major surface of the semiconductor substrate for protecting the Hall effect element, the control current supply circuit and the Hall voltage output circuit from noise in cooperation with the shielding layer.
8. A noise-proof, integrated semiconductor current detector as defined in claim 7 , wherein the shielding layer is electrically connected to the baseplate.