Magnetic sensing device, and magnetic sensing method and manufacturing technology thereof

[0063] Embodiment one

[0064] see Image 6 , Figure 7 ,in, Figure 7 Yes Image 6 The projection along the A-A direction; the present invention discloses a magnetic sensing device, which includes a Z-axis magnetic sensing component, and the Z-axis magnetic sensing component includes: a base 10, a magnetic conduction unit 20, and an induction unit; the base 10 may include CMOS peripheral circuits.

[0065] The surface of the substrate 10 has a dielectric layer, and a groove 11 is opened in the dielectric layer. The substrate is provided with one row or several rows of grooves. In this embodiment, one row of grooves includes several sub-grooves 11 .

[0066] The main part of the magnetic conduction unit 20 is disposed in the groove 11 , and a part is exposed from the groove 11 to the surface of the substrate for collecting the magnetic signal along the Z-axis and outputting the magnetic signal to the sensing unit.

[0067] The induction unit is disposed on the surface of the base to receive the magnetic signal in the Z-axis direction output by the magnetic conduction unit 20 , and measure the magnetic field strength and magnetic field direction corresponding to the Z-axis direction according to the magnetic signal. The sensing unit includes a magnetic material layer 30 and a plurality of electrodes 40 arranged in parallel on the magnetic material layer 30 . At the same time, the sensing unit is also used to sense the magnetic signals in the X-axis and Y-axis directions, and measure the magnetic field strength and magnetic field direction corresponding to the X-axis and Y-axis directions. Through the arrangement of the magnetic conduction unit 20, the induction unit guides the magnetic field in the Z-axis direction to the horizontal direction for measurement. The magnetic material layer 30 of the magnetic conduction unit 20 and the induction unit uses the same magnetic material, the number of layers is consistent, and the same deposition is obtained; such as the magnetic material layer 30 of the magnetic conduction unit 20 and the induction unit can be an anisotropic magnetic sensor AMR, TMR and GMR may also be used, which will not be described in detail below. Of course, the magnetic material layer 30 of the magnetic conduction unit 20 and the induction unit can also use different magnetic materials, or adopt different numbers of layers, that is, it can be obtained by multiple deposition and photolithography.

[0068] like Figure 7 As shown, the included angle between the main body of the magnetic conduction unit 20 and the plane of the base surface can be between 45° and 90°, the larger the better. The magnetic material layer 30 of the induction unit is arranged close to the surface of the substrate and parallel to the surface of the substrate.

[0069] see Figure 8 , the magnetic permeable unit 20 includes four permeable subunits, respectively a first permeable subunit, a second permeable subunit, a third permeable subunit, and a fourth permeable subunit. Each magnetic subunit includes a number of magnetic components, the main part of each magnetic component is arranged in the corresponding groove 11, and part of it is exposed outside the groove 11; the exposed part is arranged close to the magnetic material layer of the corresponding induction subunit, and the distance c Preferably 0-20um, typical values ​​are 0um, 0.1um, 0.3um, 0.5um, 0.8um, 1um, 5um. In addition, if Figure 7 As shown, the range of a is 0-2um (such as 0.5um, 1um); the range of b is 0-1um (such as 0um, 0.1um, 0.2um); the range of d is 0.5-10um (such as 3um, 2um); Theta has an angular range of 0-45° (eg 5°).

[0070] The sensing unit includes four sensing sub-units, namely a first sensing sub-unit, a second sensing sub-unit, a third sensing sub-unit, and a fourth sensing sub-unit. Each of the above-mentioned inductive subunits includes a magnetic material layer 30, and the magnetic material layer is provided with a plurality of electrodes 40 arranged in parallel; the angle between the arrangement direction of the electrodes 40 and the magnetization direction of the magnetic material layer 30 is 10 ° ~ 80 °, preferably 45°.

[0071] The first magnetically permeable subunit cooperates with the first inductive subunit as the first inductive module of the Z-axis magnetic sensing component; the second magnetically permeable subunit cooperates with the second inductive subunit as the Z-axis magnetic sensor The second sensing module of the sensing part; the third magnetic permeable subunit cooperates with the third sensing subunit as the third sensing module of the Z-axis magnetic sensing component; the fourth magnetic permeable subunit cooperates with the fourth inductor Unit coordination; the fourth sensing module as a Z-axis magnetic sensing component.

[0072] Figure 8 The magnetic sensing device shown adopts a Wheatstone bridge structure, which can measure the external magnetic field more sensitively. In practical applications, a magnetic permeable subunit and an inductive subunit can also be used, that is, the magnetic field can be measured, which will not be repeated here.

[0073] In one embodiment of the present invention, the device further includes an X-axis and Y-axis magnetic sensing component, which is used to sense a magnetic signal in the direction of the X-axis or/and Y-axis, and thereby measure the X-axis or/and Y-axis The direction corresponds to the magnetic field strength and the direction of the magnetic field. The X-axis and Y-axis magnetic sensing components are not the sensing unit of the Z-axis magnetic sensing component; the sensing unit of the Z-axis magnetic sensing component is for sensing the direction of the Z-axis, while the sensing unit of the X-axis and Y-axis magnetic sensing components is for Sense the orientation of the X-axis or/and Y-axis.

[0074] The X-axis or Y-axis magnetic sensing component includes four inductive subunits, which are respectively the fifth inductive subunit, the sixth inductive subunit, the seventh inductive subunit, and the eighth inductive subunit; each of the above inductive subunits includes The magnetic material layer is provided with a plurality of electrodes arranged in parallel; the included angle between the arrangement direction of the electrodes and the magnetization direction of the magnetic material layer is 10°-80°, preferably 45°. Similarly, the X-axis and Y-axis magnetic sensing components may only include one sensing unit, that is, the Wheatstone bridge may not be used.

[0075] The structure of the magnetic sensing device of the present invention has been introduced above. The present invention discloses the magnetic sensing method of the magnetic sensing device while disclosing the above magnetic sensing device. The method includes a step of magnetic field induction in the Z-axis direction, specifically including: the magnetic conduction unit collects the magnetic signal in the Z-axis direction, and outputs the magnetic signal; the induction unit receives the magnetic signal in the Z-axis direction output by the magnetic conduction unit, and According to the magnetic signal, the magnetic field strength and magnetic field direction corresponding to the Z-axis direction are measured.

[0076] In addition, the method further includes a magnetic field sensing step in the X-axis and Y-axis directions, including: sensing magnetic signals in the X-axis and Y-axis directions, and measuring the magnetic field strength and magnetic field direction corresponding to the X-axis and Y-axis directions.

[0077] At the same time, the present invention also discloses a preparation process of the above-mentioned magnetic sensing device, and the preparation process includes the following steps:

[0078] [Step S1 ] Setting a substrate, which may include CMOS peripheral circuits.

[0079] [Step S2 ] A dielectric layer is provided on the surface of the substrate to isolate the sensing device from the substrate, and grooves are formed on the dielectric layer by a manufacturing process.

[0080] [Step S3] Deposit magnetic materials and protective layer materials on the surface of the substrate. The magnetic materials and protective layer materials are single-layer or multi-layer materials, and then the induction unit and the magnetic conduction unit are simultaneously formed through the manufacturing process. Therefore, the magnetic conduction unit and the magnetic conduction unit The sensing unit uses the same magnetic material and is obtained by the same deposition. The main body of the magnetic conduction unit is deposited in the groove, and a part of the magnetic conduction unit is exposed to the surface of the substrate.

[0081] Preferably, the magnetic sensing device of the present invention also includes X-axis and Y-axis sensing components; in step S3, depositing the magnetic material layer required by the X-axis and Y-axis magnetic sensing components while depositing the sensing unit and the magnetic conduction unit on the surface of the substrate ; That is, the magnetic material layer required by the X-axis and Y-axis and the induction unit and the magnetic conduction unit required by the Z-axis are prepared simultaneously.

[0082] Optionally, in this step, the induction unit and the magnetic conduction unit can be formed respectively through multiple material deposition and manufacturing processes, that is, different material layers are used for the two.

[0083] [Step S4] Electrode layers are respectively provided on the magnetic material layers of the sensing unit and the X-axis and Y-axis sensing components, and then a complete sensing device is manufactured through processes such as dielectric filling and lead wires.

[0084] Embodiment two

[0085] The difference between this embodiment and Embodiment 1 is that in this embodiment, multiple magnetic permeable structures can share the same groove; please refer to Figure 9 The grooves 11 on the substrate 10 can be arranged in one or more rows, and one row of grooves 11 can be arranged as a long and narrow groove for shared use by multiple magnetic components.

[0086] In addition, in this structure, the magnetic conduction unit can be connected with the sensing unit, that is, the distance is 0um.

[0087] Embodiment three

[0088] In this embodiment, the magnetic sensing device of the present invention further includes a CMOS chip, and the substrate described in Embodiment 1 is disposed on the CMOS chip. That is, the magnetic sensing device has the functions of the existing CMOS chip. That is to say, there are both CMOS chips and sensing devices on a single chip, which has a high degree of integration.