阅读说明：本技术 磁传感芯片、温度补偿电流传感器及其制备方法 (Magnetic sensing chip, temperature compensation current sensor and preparation method thereof ) 是由 刘明 关蒙萌 黄豪 胡忠强 朱家训 于 2020-06-03 设计创作，主要内容包括：磁传感芯片、温度补偿电流传感器及其制备方法,温度补偿电流传感器包括：聚磁环、绕制于聚磁环上的反馈线圈、设置于聚磁环缺口处的磁传感芯片、与磁传感芯片及反馈线圈相连的磁平衡电路；磁传感芯片包括形成全桥结构的隧道结磁电阻元件及热敏电阻,热敏电阻位于隧道结磁电阻元件的电极层上,电极层为钌金属层或电极层中有钌金属,热敏电阻为钌电阻,热敏电阻与温度补偿电路相连,反馈线圈向温度补偿电路输出电流信号,温度补偿电路用于根据钌电阻和所述反馈线圈输出的信号对检测结果进行补偿后输出。本发明将热敏元件集成在磁传感芯片内部,温度采集区域与磁场检测的区域更加靠近,反馈的温度信息更加准确,而且不会额外增加其它材料和工艺难度。(Magnetic sensing chip, temperature compensation current sensor and preparation method thereof, temperature compensation current sensor includes: the magnetic-field-focusing circuit comprises a magnetic-field-focusing ring, a feedback coil wound on the magnetic-field-focusing ring, a magnetic sensing chip arranged at the notch of the magnetic-field-focusing ring, and a magnetic balance circuit connected with the magnetic sensing chip and the feedback coil; the magnetic sensing chip comprises a tunnel junction magneto-resistance element and a thermistor, the tunnel junction magneto-resistance element forms a full-bridge structure, the thermistor is located on an electrode layer of the tunnel junction magneto-resistance element, the electrode layer is a ruthenium metal layer or ruthenium metal in the electrode layer, the thermistor is a ruthenium resistor, the thermistor is connected with a temperature compensation circuit, a feedback coil outputs current signals to the temperature compensation circuit, and the temperature compensation circuit is used for outputting after compensating detection results according to the ruthenium resistor and signals output by the feedback coil. According to the invention, the thermosensitive element is integrated in the magnetic sensing chip, the temperature acquisition area is closer to the magnetic field detection area, the temperature information fed back is more accurate, and other materials and process difficulties cannot be additionally increased.)

1. Magnetic sensing chip, including tunnel junction magneto resistor element and the thermistor that forms full-bridge structure, its characterized in that: the thermistor is positioned on an electrode layer of the tunnel junction magneto-resistance element, the electrode layer is a ruthenium metal layer or ruthenium metal is arranged in the electrode layer, and the thermistor is a ruthenium resistor.

2. The magnetic sensor chip of claim 1, wherein: the tunnel junction magnetoresistive element may be replaced with a GMR cell.

3. A temperature compensated current sensor comprising: the magnetic circuit comprises a magnetic gathering ring, a feedback coil wound on the magnetic gathering ring, a magnetic sensing chip arranged at the notch of the magnetic gathering ring, and a magnetic balance circuit connected with the magnetic sensing chip and the feedback coil;

the method is characterized in that: the magnetic sensing chip is the magnetic sensing chip of claim 1 or 2, the thermistor is connected to a temperature compensation circuit, the feedback coil outputs a current signal to the temperature compensation circuit, and the temperature compensation circuit is configured to compensate and output a detection result according to the ruthenium resistor and the signal output by the feedback coil.

4. The temperature-compensated current sensor of claim 3, wherein: the temperature compensation circuit comprises a temperature sampling circuit, a multiplication proportional circuit, an addition proportional circuit and a current sampling circuit; the temperature sampling circuit is connected with the ruthenium resistor, the temperature sampling circuit outputs signals to the multiplication proportional circuit, the multiplication proportional circuit outputs signals to the addition proportional circuit, the current sampling circuit collects current signals output by the feedback coil and outputs the current signals to the addition proportional circuit, the addition proportional circuit adds the signals output by the current sampling circuit and the signals output by the multiplication proportional circuit to obtain temperature compensation output signals finally output by the current sensor, and the temperature compensation output signals are simultaneously output to the multiplication proportional circuit.

5. The temperature-compensated current sensor of claim 3, wherein: the temperature compensation circuit comprises a temperature sampling circuit, an addition proportional circuit and a current sampling circuit; the temperature sampling circuit is connected with the ruthenium resistor, the temperature sampling circuit outputs signals to the addition proportion circuit, the current sampling circuit collects current signals output by the feedback coil and outputs the current signals to the addition proportion circuit, and the addition proportion circuit adds the signals output by the temperature sampling circuit and the signals output by the current sampling circuit to obtain temperature compensation output signals finally output by the current sensor.

6. The method for manufacturing a sensor chip according to claim 1 or 2, comprising the steps of:

providing a substrate;

depositing a lower electrode layer, a pinning layer, a non-magnetic layer and a free layer on a substrate, wherein the lower electrode layer is prepared from a ruthenium material;

etching a magneto-resistance element region and a thermistor region according to the layout;

depositing an upper electrode layer, preparing an electrical connection structure which comprises a connection terminal and a wiring terminal connected with the magneto-resistor element, the thermistor and the feedback coil, and electrically interconnecting the magneto-resistor element and the thermistor;

and packaging the chip.

Technical Field

The invention belongs to the technical field of current sensing, and particularly relates to a current sensor capable of performing temperature compensation and a magnetic sensing chip used by the current sensor.

Background

The magnetic balance type current sensor based on the zero magnetic flux principle has the advantages of high sensitivity, wide measurement range and the like, and is widely applied to the field of current measurement. However, due to the influence of the temperature characteristics of the magnetic field detection part and the feedback coil winding, the sensitivity of the magnetic balance type current sensor is influenced by the change of the environmental temperature, and the measurement accuracy of the current sensor is further influenced. For this reason, temperature drift compensation needs to be performed on the current sensor to ensure the measurement accuracy of the current sensor at different temperatures.

In a magnetic balance type current sensor, a magnetic sensing chip is generally installed in an air gap of a feedback coil winding, the magnetic sensing chip and the feedback coil winding are main devices causing temperature drift of the current sensor, and in order to obtain accurate temperature information of a detection area, a heat sensitive device (temperature sensing device) for feeding back the temperature information should be as close as possible to the magnetic sensing chip and the feedback coil winding so as to compensate the temperature drift of the current sensor. A more common temperature compensation means is to arrange a thermistor in the current sensor, collect the ambient temperature by using the thermistor, and arrange a temperature compensation circuit on the circuit board of the current sensor to perform temperature compensation on the output of the current sensor, so as to suppress the temperature drift of the current sensor. In order to simplify the production process of the current sensor, the thermistor is generally mounted on a circuit board of the current sensor, and the thermistor is far away from a magnetic sensing chip and a feedback coil winding, so that the temperature of a zero magnetic flux detection area of the current sensor cannot be accurately reflected, and the improvement effect on the measurement precision is limited. If the thermistor is integrated in the magnetic sensing chip, the heat sensitive device can be closer to the magnetic sensing chip and the feedback coil, so that the temperature information of the detection area can be more accurately reflected, and the temperature compensation of the current sensor is more accurate. However, the current thermistor is basically made of metal materials such as platinum, copper, nickel and the like, and because the material of the thermistor is different from that of the magnetic sensing chip, the thermistor is integrated in the magnetic sensing chip, so that the complexity of the magnetic sensing chip preparation process is undoubtedly increased, and the production cost of the current sensor is increased.

Disclosure of Invention

The invention aims to provide a magnetic sensing chip with high temperature compensation accuracy.

Another object of the present invention is to provide a current sensor which is simple to manufacture and can perform temperature compensation.

In order to achieve the first object, the invention adopts the following technical solutions:

magnetic sensing chip, including tunnel junction magneto resistor element and the thermistor that forms full-bridge structure, thermistor is located on the electrode layer of tunnel junction magneto resistor element, the electrode layer has ruthenium metal for in ruthenium metal layer or the electrode layer, thermistor is ruthenium resistance.

Further, the tunnel junction magnetoresistive element may be replaced with a GMR cell.

In order to achieve the second object, the invention adopts the following technical solutions:

a temperature compensated current sensor comprising: the magnetic circuit comprises a magnetic gathering ring, a feedback coil wound on the magnetic gathering ring, a magnetic sensing chip arranged at the notch of the magnetic gathering ring, and a magnetic balance circuit connected with the magnetic sensing chip and the feedback coil; the magnetic sensing chip is the magnetic sensing chip, the thermistor is connected with the temperature compensation circuit, the feedback coil outputs current signals to the temperature compensation circuit, and the temperature compensation circuit is used for compensating and outputting detection results according to the signals output by the ruthenium resistor and the feedback coil.

According to the technical scheme, the ruthenium resistor is used as the thermosensitive element, the ruthenium element is one of materials for preparing the tunnel junction magneto-resistance element, so that the ruthenium resistor can be integrated in the magnetic sensing chip, the thermosensitive resistor is integrated in the magnetic sensing chip, and the temperature acquisition area is closer to the magnetic field detection area, so that the temperature information fed back by the thermosensitive element is more accurate, the temperature information of the detection area can be more accurately reflected, and the temperature compensation of the current sensor is more accurate; and because the ruthenium element is used for preparing the tunnel junction magneto-resistance element, only a temperature detection area needs to be divided in the magnetic sensing chip and is connected with the temperature compensation circuit, the original preparation process of the magnetic sensing chip is basically unchanged, other equipment does not need to be added, and the production cost is favorably controlled.

Furthermore, the temperature compensation circuit comprises a temperature sampling circuit, a multiplication proportional circuit, an addition proportional circuit and a current sampling circuit; the temperature sampling circuit is connected with the ruthenium resistor, the temperature sampling circuit outputs signals to the multiplication proportional circuit, the multiplication proportional circuit outputs signals to the addition proportional circuit, the current sampling circuit collects current signals output by the feedback coil and outputs the current signals to the addition proportional circuit, the addition proportional circuit adds the signals output by the current sampling circuit and the signals output by the multiplication proportional circuit to obtain temperature compensation output signals finally output by the current sensor, and the temperature compensation output signals are simultaneously output to the multiplication proportional circuit.

By adopting the closed loop type temperature compensation circuit, the obtained feedback quantity error related to the temperature drift is less, and the temperature compensation is more stable and accurate.

Furthermore, the temperature compensation circuit comprises a temperature sampling circuit, an addition proportion circuit and a current sampling circuit; the temperature sampling circuit is connected with the ruthenium resistor, the temperature sampling circuit outputs signals to the addition proportion circuit, the current sampling circuit collects current signals output by the feedback coil and outputs the current signals to the addition proportion circuit, and the addition proportion circuit adds the signals output by the temperature sampling circuit and the signals output by the current sampling circuit to obtain temperature compensation output signals finally output by the current sensor.

And an open-loop temperature compensation circuit is adopted, so that the circuit structure is simple and the manufacturing cost is low.

The invention also provides a preparation method of the sensor chip, which comprises the following steps:

providing a substrate;

depositing a lower electrode layer, a pinning layer, a non-magnetic layer and a free layer on a substrate, wherein the lower electrode layer is prepared from a ruthenium material;

etching a magneto-resistance element region and a thermistor region according to the layout;

depositing an upper electrode layer, preparing an electrical connection structure which comprises a connection terminal and a wiring terminal connected with the magneto-resistor element, the thermistor and the feedback coil, and electrically interconnecting the magneto-resistor element and the thermistor;

and packaging the chip.

Drawings

In order to illustrate the embodiments of the present invention more clearly, the drawings that are needed in the description of the embodiments or the prior art will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and that other drawings can be obtained by those skilled in the art without inventive effort.

FIG. 1 is a schematic structural view of example 1 of the present invention;

fig. 2 is a schematic structural diagram of a magnetic sensor chip according to embodiment 1 of the present invention;

FIG. 3 is a circuit block diagram of embodiment 1 of the present invention;

FIG. 4 is a signal block diagram of a temperature compensation circuit according to embodiment 1 of the present invention;

FIG. 5 is a circuit block diagram according to embodiment 2 of the present invention;

fig. 6 is a signal block diagram of a temperature compensation circuit according to embodiment 2 of the present invention.

Detailed Description

In order to make the aforementioned and other objects, features and advantages of the present invention more apparent, embodiments of the present invention will be described in detail below with reference to the accompanying drawings.