Pressure sensor and electronic device

Abstract

The utility model discloses a pressure sensor and an electronic device, the pressure sensor comprises a substrate, a plurality of external contact points, a plurality of strain resistors and at least one adjustable resistor unit, and each external contact point is arranged in a non-strain area of the substrate. And each strain resistor is arranged in the strain area of the substrate. The adjustable resistor unit is arranged in the non-strain area of the substrate, the first end of the adjustable resistor unit is connected with one external contact point, and the second end of the adjustable resistor unit is connected with one strain resistor. And the adjustable resistor unit is used for configuring impedance between the strain resistor and the corresponding outer contact point. The adjustable resistor unit can be used for adjusting the distance between the strain resistor and the external contact point, and the adjustable resistor unit can be used for adjusting the impedance between the strain resistor and the corresponding external contact point when the pressure sensor is corrected, so that the correction of the pressure sensor is realized.

Description

Technical Field

[0001] The present application belongs to the technical field of pressure sensors, and in particular, relates to a pressure sensor and an electronic device. Background Art

[0002] At present, traditional full-bridge strain gauge chips usually include multiple bridge arm resistors. When processing the bridge arm resistors of the chip, a specific pattern mask is required to perform ion implantation on the specified semiconductor area. During this process, the resistance value of the doped area may be greater than or less than the simulation calculated value.

[0003] The bridge arm resistor values ​​of most piezoresistive pressure sensor chips on the market cannot be adjusted. If it is found that the bridge arm resistance value deviates greatly from the expected simulation value after production and processing is completed, it is usually necessary to mount the resistor on the substrate and add a compensation resistor on the substrate for adjustment. Utility Model Content

[0004] The purpose of the present application is to provide a pressure sensor and an electronic device, aiming to solve the problem that the bridge arm resistance of a traditional piezoresistive pressure sensor is difficult to calibrate.

[0005] A first aspect of an embodiment of the present application provides a pressure sensor, comprising: a substrate; a plurality of external contact points, arranged in a non-strain area of ​​the substrate, the external contact points being used for external circuit connection; a plurality of strain resistors, arranged in the strain area of ​​the substrate; at least one adjustable resistance unit, the adjustable resistance unit being arranged in the non-strain area of ​​the substrate, the first end of the adjustable resistance unit being connected to one of the external contact points, the second end of the adjustable resistance unit being connected to one of the strain resistors, the adjustable resistance unit being used to configure the impedance between the strain resistor and the corresponding external contact point.

[0006] In one embodiment, the adjustable resistance unit includes a plurality of compensation resistors constructed in the substrate and a plurality of first metal wires and a plurality of second metal wires constructed on the surface of the substrate; the first ends of the compensation resistors are interconnected through a plurality of the first metal wires, and the second ends of the compensation resistors are interconnected through a plurality of the second metal wires, the first end of one of the compensation resistors is connected to the corresponding external contact point, and the second end of one of the compensation resistors is connected to the corresponding strain resistor; and the first end and the second end of one of the compensation resistors are connected through the first metal wire or the second metal wire.

[0007] In one embodiment, the non-strained region of the substrate includes a first N-type silicon, an oxide layer, a second N-type silicon and an insulating layer stacked in sequence from bottom to top, the strained region of the substrate includes the oxide layer, the second N-type silicon and the insulating layer, and the sum of the thickness of the oxide layer, the thickness of the second N-type silicon and the thickness of the insulating layer is less than the thickness of the first N-type silicon.

[0008] In one embodiment, the compensation resistor and the strain resistor are both arranged in the second N-type silicon, and the materials of the compensation resistor and the strain resistor are both N-type silicon implanted with group III ions.

[0009] In one embodiment, the ion concentration of the compensation resistor is greater than the ion concentration of the strain resistor, and the size of the strain resistor is greater than the compensation resistor.

[0010] In one embodiment, a plurality of via holes are provided in the insulating layer, and the via holes are used to connect the compensation resistor with the corresponding first metal wire or the second metal wire.

[0011] In one embodiment, the thickness of the non-strained region of the substrate is 300um to 400um, and the thickness of the strained region of the substrate is 10um to 20um.

[0012] In one embodiment, the pressure sensor includes a total of four strain resistors and four external contact points; one external contact point is connected to at least two strain resistors, and both ends of the strain resistor are respectively connected to the corresponding external contact points; one strain resistor is connected to at least one adjustable resistance unit.

[0013] In one embodiment, the strained region is disposed at the center of the non-strained region, and the non-strained region surrounds the strained region.

[0014] A second aspect of the embodiments of the present application provides an electronic device including the pressure sensor as described above.

[0015] Compared with the prior art, the embodiments of the present application have the following beneficial effects: the impedance between the strain resistor and the external contact point can be adjusted through the adjustable resistor unit. When calibrating the pressure sensor, the impedance between the strain resistor and the corresponding external contact point can be adjusted through the adjustable resistor unit to achieve calibration of the pressure sensor. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 A schematic diagram of the structure of a pressure sensor provided in one embodiment of the present application;

[0017] Figure 2 A schematic diagram of the principle of an adjustable resistance unit provided in an embodiment of the present application;

[0018] Figure 3 A schematic diagram of the structure of a substrate provided in one embodiment of the present application;

[0019] Figure 4 A schematic diagram of a specific configuration of an adjustable resistance unit provided in an embodiment of the present application;

[0020] Figure 5 Another specific configuration diagram of an adjustable resistance unit provided in an embodiment of the present application;

[0021] Figure 6 A schematic diagram of the structure of an electronic device provided in one embodiment of the present application. DETAILED DESCRIPTION

[0022] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0023] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0024] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0025] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0026] Figure 1 The structure diagram of the pressure sensor provided by an embodiment of the present application is shown. For the convenience of description, only the part related to the present embodiment is shown, which is described in detail as follows:

[0027] The pressure sensor 10 includes a substrate 100 , a plurality of external contacts 200 , a plurality of strain resistors 300 , and at least one adjustable resistance unit 400 .

[0028] Among them, each external contact point 200 is arranged in the non-strained area 110 of the substrate 100, and the external contact point 200 is used for external circuit connection. Each strain resistor 300 is arranged in the strained area 120 of the substrate 100. The adjustable resistance unit 400 is arranged in the non-strained area 110 of the substrate 100, and the first end of the adjustable resistance unit 400 is connected to an external contact point 200, and the second end of the adjustable resistance unit 400 is connected to a strain resistor 300. The adjustable resistance unit 400 is used to configure the impedance between the strain resistor 300 and the corresponding external contact point 200.

[0029] It is understandable that the adjustable resistance unit 400 can be connected to the strain resistor 300 and the external contact point 200 respectively through the wires arranged on the substrate 100, and the impedance between the strain resistor 300 and the external contact point 200 can be adjusted through the adjustable resistance unit 400. For the external circuit, the impedance of the adjustable resistance unit 400 will also be regarded as the impedance of the strain resistor 300. Therefore, when calibrating the pressure sensor 10, the impedance between the strain resistor 300 and the corresponding external contact point 200 can be adjusted through the adjustable resistance unit 400 to achieve the calibration of the pressure sensor 10.

[0030] For example, when the resistance value of the strain resistor 300 in the absence of stress is less than the ideal resistance value, the missing resistance value can be compensated by the adjustable resistance unit 400 to achieve calibration of the pressure sensor 10 .

[0031] In one embodiment, if Figure 2 , Figure 3 As shown, the adjustable resistance unit 400 includes a plurality of compensation resistors 410 constructed in the substrate 100 and a plurality of first metal wires 420 and a plurality of second metal wires 430 constructed on the surface of the substrate 100 .

[0032] The first ends of the compensation resistors 410 are connected to each other through a plurality of first metal wires 420 constructed on the surface of the substrate 100, and the second ends of the compensation resistors 410 are connected to each other through a plurality of second metal wires 430 constructed on the surface of the substrate 100, wherein the first end of one of the compensation resistors 410 is connected to the corresponding external contact point 200, and the second end of one of the compensation resistors 410 is connected to the corresponding strain resistor 300. The first end and the second end of one of the compensation resistors 410 are connected through the first metal wire 420 or the second metal wire 430.

[0033] It is understandable that, according to actual needs, the corresponding first metal wire 420 and / or the second metal wire 430 can be disconnected by laser, so that the corresponding number of compensation resistors 410 are connected in series or in parallel between the strain resistor 300 and the external contact point 200, and the strain resistor 300 and the external contact point 200 can also be directly connected, so as to adjust the resistance of the adjustable resistor unit 400 to meet the needs. The first metal wire 420 and the second metal wire 430 can be constructed by a metal deposition process.

[0034] Exemplarily, when the first end and the second end of one of the compensation resistors 410 are connected through the first metal wire 420 , and the first metal wire 420 is not disconnected, all the compensation resistors 410 will be short-circuited.

[0035] It is understandable that if Figure 3 As shown, since the compensation resistor 410 is arranged in the substrate 100, and the first metal wire 420 and the second metal wire 430 are arranged on the surface of the substrate 100, it is necessary to realize the connection between the compensation resistor 410 and the corresponding first metal wire 420 and the second metal wire 430 through a structure similar to a via 440. In some embodiments, the compensation resistor 410 is connected to the corresponding first metal wire 420 and the second metal wire 430 through a via 440, and a plurality of metal sheets are also provided on the surface of the substrate 100, one metal sheet corresponds to one via 440, and the metal sheet is used to cover the corresponding via 440. The metal sheet can be used to connect to an external circuit as a node during detection to achieve accurate measurement. At the same time, each strain resistor 300 is also connected to a wire arranged on the surface of the substrate 100 through a corresponding via 440, so as to be connected to the corresponding adjustable resistance unit 400 and the corresponding external contact point 200 through the corresponding wire.

[0036] In some embodiments, the resistance values ​​of the compensation resistors 410 are the same, the compensation resistors 410 are arranged in parallel in the substrate 100, and the two ends of the compensation resistors 410 are aligned with each other. Among them, the first ends and the second ends of the plurality of compensation resistors 410 may be connected through the first metal wire 420 or the second metal wire 430.

[0037] It is understandable that the resistance values ​​of the compensation resistors 410 may be different, and the resistance values ​​of the compensation resistors 410 may be set according to actual needs.

[0038] In one embodiment, if Figure 3As shown, the unstrained region 110 of the substrate 100 includes a first N-type silicon 130, an oxide layer 140, a second N-type silicon 150 and an insulating layer 160 stacked in sequence from bottom to top, and the strained region 120 of the substrate 100 includes an oxide layer 140, a second N-type silicon 150 and an insulating layer 160, and the sum of the thickness of the oxide layer 140, the thickness of the second N-type silicon 150 and the thickness of the insulating layer 160 is less than the thickness of the first N-type silicon 130.

[0039] It should be noted that the substrate 100 can be obtained by first constructing the first N-type silicon 130, the oxide layer 140, and the second N-type silicon 150 stacked in sequence from bottom to top, and then etching the first N-type silicon 130 of the strained region 120 until the first N-type silicon 130 of the strained region 120 is completely etched away. After each strain resistor 300 and the compensation resistor 410 are constructed in the second N-type silicon 150, the second N-type silicon 150 is covered with an insulating layer 160, and the insulating layer 160 is used to protect the second N-type silicon 150.

[0040] In one embodiment, the compensation resistor 410 and the strain resistor 300 are both disposed in the second N-type silicon 150 , and the materials of the compensation resistor 410 and the strain resistor 300 are both N-type silicon implanted with group III ions.

[0041] For example, the compensation resistor 410 and the strain resistor 300 may be constructed by doping the second N-type silicon 150 with boron ions.

[0042] In some embodiments, the insulating layer 160 is made of silicon nitride, and the first N-type silicon 130 and the second N-type silicon 150 are both made of N-type silicon, which is a silicon material doped with group V element ions, and phosphorus ions can be doped into silicon to obtain N-type silicon. The oxide layer 140 can be obtained by oxidizing N-type silicon.

[0043] In one embodiment, the ion concentration of the compensation resistor 410 is greater than the ion concentration of the strain resistor 300 , and the size of the strain resistor 300 is greater than that of the compensation resistor 410 .

[0044] It should be noted that when constructing the compensation resistor 410 and the strain resistor 300, the resistance value of each resistor when not under stress can be controlled by controlling the size of each resistor. The ion concentration of the injected group III ions will also affect the resistance value of each resistor. The ion concentration of the compensation resistor 410 is greater than the ion concentration of the strain resistor 300 in order to reduce the resistance value of the compensation resistor 410 as much as possible, so as to compensate the strain resistor 300 more accurately.

[0045] In some embodiments, the number of the compensation resistors 410 is 8 to 20, and the resistance value of the compensation resistors 410 is 10 ohms to 40 ohms.

[0046] For example, in some embodiments, Figure 2 As shown, the number of the compensation resistors 410 is 9, and the resistance value of the compensation resistor 410 is 10 ohms. When a 20 ohm adjustable resistor unit 400 is required, as shown in FIG. Figure 4 As shown, the corresponding first metal wire 420 and the second metal wire 430 can be disconnected so that the two compensation resistors 410 are connected in series between the strain resistor 300 and the external contact point 200. When a 5 ohm adjustable resistor unit 400 is required, as shown in FIG. Figure 5 As shown, the corresponding first metal wire 420 and the second metal wire 430 may be disconnected so that the two compensation resistors 410 are connected in parallel between the strain resistor 300 and the external contact point 200 .

[0047] In one embodiment, the thickness of the non-strained region 110 of the substrate 100 is 300 um to 400 um, and the thickness of the strained region 120 of the substrate 100 is 10 um to 20 um.

[0048] It can be understood that the thickness of the unstrained region 110 is the sum of the thickness of the first N-type silicon 130, the thickness of the oxide layer 140, the thickness of the second N-type silicon 150 and the thickness of the insulating layer 160, and the thickness of the strained region 120 is the sum of the thickness of the oxide layer 140, the thickness of the second N-type silicon 150 and the thickness of the insulating layer 160.

[0049] The thickness of the non-strained area 110 is much greater than the thickness of the strained area 120. When the pressure sensor 10 is subjected to stress, the strained area 120 will produce a certain deformation, causing the resistance value of the strain resistor 300 therein to change. Then, the parameters of the stress can be obtained through the changes in the resistance values ​​of each strain resistor 300.

[0050] In one embodiment, if Figure 1 As shown, the pressure sensor 10 includes four strain resistors 300 and four external contact points 200 .

[0051] One external contact point 200 is connected to at least two strain resistors 300 , and two ends of the strain resistor 300 are respectively connected to corresponding external contact points 200 . One strain resistor 300 is connected to at least one adjustable resistance unit 400 .

[0052] It can be understood that the four strain resistors 300 can form a bridge strain circuit, the external circuit can be connected to the four external contact points 200, and based on the change in the resistance value of the four strain resistors 300, the parameters of the stress to which the pressure sensor 10 is subjected can be obtained.

[0053] In one embodiment, if Figure 1 As shown, the strained region 120 is disposed at the center of the non-strained region 110 , and the non-strained region 110 surrounds the strained region 120 .

[0054] Specifically, in some embodiments, Figure 1 As shown, the strain region 120 is rectangular, the outer contour of the non-strain region 110 is also rectangular, the side length of the strain region 120 is 500um to 750um, and the side length of the non-strain region 110 is 900um to 1500um. Four external contact points 200 are respectively arranged at the four corners of the non-strain region 110, and four strain resistors 300 are respectively arranged beside the four sides of the strain region 120.

[0055] Figure 6 A schematic diagram of the structure of an electronic device provided in an embodiment of the present application is shown. For the sake of convenience, only the parts related to the present embodiment are shown, which are described in detail as follows:

[0056] The electronic device 20 includes the pressure sensor 10 as in any of the above embodiments. The electronic device 20 may be a device such as a barometer.

[0057] The pressure sensor 10 includes a substrate 100 , a plurality of external contacts 200 , a plurality of strain resistors 300 , and at least one adjustable resistance unit 400 .

[0058] Among them, each external contact point 200 is arranged in the non-strained area 110 of the substrate 100, and the external contact point 200 is used for external circuit connection. Each strain resistor 300 is arranged in the strained area 120 of the substrate 100. The adjustable resistance unit 400 is arranged in the non-strained area 110 of the substrate 100, and the first end of the adjustable resistance unit 400 is connected to an external contact point 200, and the second end of the adjustable resistance unit 400 is connected to a strain resistor 300. The adjustable resistance unit 400 is used to configure the impedance between the strain resistor 300 and the corresponding external contact point 200.

[0059] It is understandable that the adjustable resistance unit 400 can be connected to the strain resistor 300 and the external contact point 200 respectively through the wires arranged on the substrate 100, and the impedance between the strain resistor 300 and the external contact point 200 can be adjusted through the adjustable resistance unit 400. For the external circuit, the impedance of the adjustable resistance unit 400 will also be regarded as the impedance of the strain resistor 300. When calibrating the pressure sensor 10, the impedance between the strain resistor 300 and the corresponding external contact point 200 can be adjusted through the adjustable resistance unit 400 to achieve calibration of the pressure sensor 10.

[0060] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0061] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0062] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. A pressure sensor, characterized in that: include: substrate; A plurality of external contact points are arranged in the non-strained area of ​​the substrate, and the external contact points are used for external circuit connection; A plurality of strain resistors are arranged in the strain region of the substrate; At least one adjustable resistance unit, wherein the adjustable resistance unit is arranged in a non-strain area of ​​the substrate, a first end of the adjustable resistance unit is connected to one of the external contact points, a second end of the adjustable resistance unit is connected to one of the strain resistors, and the adjustable resistance unit is used to configure the impedance between the strain resistor and the corresponding external contact point.

2. The pressure sensor according to claim 1, characterized in that The adjustable resistance unit includes a plurality of compensation resistors constructed in the substrate and a plurality of first metal wires and a plurality of second metal wires constructed on the surface of the substrate; The first ends of the compensation resistors are interconnected through multiple first metal wires, and the second ends of the compensation resistors are interconnected through multiple second metal wires, wherein the first end of one of the compensation resistors is connected to the corresponding external contact point, and the second end of one of the compensation resistors is connected to the corresponding strain resistor; and the first end and the second end of one of the compensation resistors are connected through the first metal wire or the second metal wire.

3. The pressure sensor according to claim 2, characterized in that The non-strained region of the substrate includes a first N-type silicon, an oxide layer, a second N-type silicon and an insulating layer stacked in sequence from bottom to top, the strained region of the substrate includes the oxide layer, the second N-type silicon and the insulating layer, and the sum of the thickness of the oxide layer, the thickness of the second N-type silicon and the thickness of the insulating layer is less than the thickness of the first N-type silicon.

4. The pressure sensor according to claim 3, characterized in that The compensation resistor and the strain resistor are both arranged in the second N-type silicon, and the materials of the compensation resistor and the strain resistor are both N-type silicon implanted with group III ions.

5. The pressure sensor according to claim 4, characterized in that: The ion concentration of the compensation resistor is greater than the ion concentration of the strain resistor, and the size of the strain resistor is greater than the compensation resistor.

6. The pressure sensor according to claim 3, characterized in that: A plurality of via holes are provided in the insulating layer, and the via holes are used to connect the compensation resistor with the corresponding first metal wire or the second metal wire.

7. The pressure sensor according to any one of claims 1 to 6, characterized in that: The thickness of the non-strained region of the substrate is 300um to 400um, and the thickness of the strained region of the substrate is 10um to 20um.

8. The pressure sensor according to any one of claims 1 to 6, characterized in that: The pressure sensor comprises a total of four strain resistors and four external contact points; One of the external contact points is connected to at least two of the strain resistors, and two ends of the strain resistor are respectively connected to the corresponding external contact points; One of the strain resistors is connected to at least one of the adjustable resistor units.

9. The pressure sensor according to any one of claims 1 to 6, characterized in that: The strained region is disposed at the center of the non-strained region, and the non-strained region surrounds the strained region.

10. An electronic device, characterized in that: Comprising the pressure sensor as described in any one of claims 1-9.

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