Full-bridge semiconductor strain gauge and manufacturing method thereof

Abstract

A low-cost full-bridge semiconductor strain gauge includes a semiconductor layer including fourth and third pad bases respectively located on left and right sides of a reference point, a first pad base located on a left upper side of the fourth pad base, and a second pad base located on a right upper side of the third pad base; a first bridge arm resistor located on a left upper side of the reference point and extending to the first and fourth pad bases, a third bridge arm resistor located on a right upper side of the reference point and extending to the third and second pad bases, a fourth bridge arm resistor located on a lower side of the reference point and extending to the fourth and third pad bases, and a second bridge arm resistor located on a lower side of the reference point and extending to the first and second pad bases; a metal layer attached to a front side surface of the semiconductor layer; and the second bridge arm resistor surrounds the fourth bridge arm resistor from a lower side.

Description

Technical Field

[0001] This application relates to the field of sensor technology, specifically to a full-bridge semiconductor strain gauge and its fabrication method. Background Technology

[0002] like Figure 1 As shown, a Wheatstone bridge is typically used for signal measurement. It consists of four resistors R1 to R4 connected sequentially, positioned on the four arms of the Wheatstone bridge. At least R1 and R3 are variable resistors, while R2 and R4 are either fixed or variable resistors. The potentials at their four connection points (corresponding solder joints or pads P1 to P4) are V1, Vd, V2, and Vc, respectively. Vd can be grounded, Vc-Vd can be the input voltage, and V2-V2 can be the output voltage. To ensure linear output voltage variation, R1 and R3 are equal, and R2 and R4 are equal. Assuming R1 / R2 = R3 / R4 = k, then:

[0003]

[0004] If the initial output is zero, then the initial value of k should be 1, that is, the initial values ​​of R1 to R4 are all the same.

[0005] Strain gauges, also known as resistance strain gauges, are widely used for measuring force or pressure. They are constructed using sheet-like resistors as bridge arms, forming a Wheatstone bridge as described above. Resistance strain gauges can be manufactured as four quarter-resistance strain gauges, meaning each strain gauge contains only one bridge arm resistor. To increase the resistance value, the bridge arms are often meandering, with a solder pad at each end for connection to circuit components.

[0006] More often, the Wheatstone bridge is fabricated as two half-bridge strain gauges, each with two resistors, dividing pads P2 and P4 into two parts, resulting in a total of six pads. Semiconductor strain gauges, on the other hand, utilize the resistance change of semiconductors such as silicon under pressure (where the resistance change caused by the change in material shape is negligible), and therefore can be used as the semiconductor bridge arm resistors for pressure measurement.

[0007] Figure 2The diagram illustrates the structure of a conventional half-bridge silicon strain gauge 01, fabricated using microfabrication techniques. It includes a bottom layer of semiconductor silicon 010 with two strain gauges 011 and 012 that are mirror-symmetrical about a transverse straight line. Resistors 011 and 012 are composed of longitudinally extending, meandering silicon strips 011a to 011d. A metal layer 015 covers the upper side of the transverse connection of the silicon strips 011a to 011d to prevent the transverse connection of the semiconductor silicon from affecting the resistors 011 and 012. A first pad 014 and a second pad 013 are formed in the metal layer 015 at both ends of the resistor 011 for connection to an electronic module via leads. The two resistors 011 share a second pad 013, with one transverse end of the second pad 013 extending longitudinally to both sides and flush with the outer side of the first pad 014. To ensure the pads have appropriate length and spacing, support silicon strips 011e (not included in the resistance value) are provided in some unavoidable empty spaces to serve a supporting function. For example... Figure 3 As shown, in use, two half-bridge silicon strain gauges 01 are respectively arranged on both sides of the central strain point Pc on the surface of the plate-shaped elastic body 02, so that the resistance 011 of each half-bridge silicon strain gauge 01 is in the low strain region 02b, and the resistance 012 is in the high strain region 02a (i.e., relatively closer to the central strain point Pc in terms of distance), so that the changes in resistance 011 and 012 are different. The two half-bridge silicon strain gauges 01 are preferably located on a longitudinally extending centerline Pm passing through the central strain point Pc.

[0008] Figure 4 The structure of a known full-bridge silicon strain gauge is shown, which is basically composed of two transversely arranged, generally symmetrically positioned half-bridge strain gauges 01 on the centerline Pm. In order to allow the resistors of the two high-strain regions 02a to be located on two non-adjacent arms of the Wheatstone bridge, they share a first pad 014 with the strain resistor 012 located in the high-strain region 02a and the strain resistor 011 located in the low-strain region 02b of the other half-bridge strain gauge 01. Figure 4The five pads are arranged longitudinally towards the center and laterally, with their lengths aligned longitudinally to maximize the difference in longitudinal distance between the high-strain region 02a and the low-strain region 02b, thus achieving greater measurement accuracy. This also allows the width of a single half-bridge strain gauge 01 to be reduced to a width W1 including four rows of silicon strips. Since the pads need to be connected to the outside via wires (usually gold wires), they must have suitable lengths and minimum widths, and insulation between the pads must be met. Therefore, after laterally separating the pads, a width W2 is needed for the shared first pad 014 in the middle laterally. Due to the large lateral distance, supporting silicon strips 011e are also required at corresponding positions. Thus, this full-bridge semiconductor strain gauge requires a total width of 2W1 + W2, with a total of five pads, necessitating five wire bonding operations to the outside.

[0009] The statements in this section are provided only as background information in relation to this application and may not constitute prior art. Summary of the Invention

[0010] To address the shortcomings of existing technologies, this application provides a full-bridge semiconductor strain gauge that reduces the number of pads to four while simultaneously reducing its total width, all while meeting usage requirements.

[0011] To achieve the above objectives, this application provides the following technical solution: a full-bridge semiconductor strain gauge, comprising, wherein:

[0012] The semiconductor layer, with its thickness along the front-to-back direction, includes four pad bases and four bridge arm resistors forming a Wheatstone full bridge.

[0013] The four pad bases include a fourth pad base and a third pad base located on the left and right sides of a reference point, respectively, a first pad base located on the upper left side of the fourth pad base, and a second pad base located on the upper right side of the third pad base.

[0014] The four bridge arm resistors include a first bridge arm resistor located above the reference point and extending to the first pad base and the fourth pad base at both ends, a third bridge arm resistor located above the reference point and extending to the third pad base and the second pad base at both ends, a fourth bridge arm resistor located below the reference point and extending to the fourth pad base and the third pad base at both ends, and a second bridge arm resistor located below the reference point and extending to the first pad base and the second pad base at both ends; wherein, each of the four bridge arm resistors includes a plurality of resistor bars extending vertically and sequentially connected and a plurality of lateral connecting portions extending horizontally and connecting to two adjacent resistor bars;

[0015] The metal layer attached to the front surface of the semiconductor layer includes four pads respectively covering the front surface of the four pad bases and multiple covering portions respectively covering the front surface of the lateral connection portions, the lateral connection portions being located on the upper and lower outer sides of the four pad bases.

[0016] Among them, the resistor strips are distributed on multiple vertical lines that extend vertically and are spaced apart horizontally, and the second bridge arm resistor surrounds the fourth bridge arm resistor from the bottom.

[0017] Preferably, the multiple vertical lines are equidistant and

[0018] Preferably, the resistor strips have the same width.

[0019] Preferably, the first bridge arm resistor and the third bridge arm resistor are arranged symmetrically on the left and right.

[0020] Preferably, the total length of the resistor strip in each bridge arm resistor is the same as the total length of the resistor strip in the other bridge arm resistors.

[0021] Preferably, each of the four bridge arm resistors includes four resistor bars and three lateral connecting portions connecting every two adjacent resistor bars, and the four resistor bars form a "U" shaped bend at the three lateral connecting portions.

[0022] Preferably, there are a total of eight vertical lines. The four resistor bars of the first bridge arm resistor are arranged sequentially on the first to fourth vertical lines, the four resistor bars of the third bridge arm resistor are arranged sequentially on the fifth to eighth vertical lines, the four resistor bars of the second bridge arm resistor are arranged sequentially on the first, fourth, fifth and eighth vertical lines, and the four resistor bars of the fourth bridge arm resistor are arranged sequentially on the second, third, sixth and seventh vertical lines. The fourth bridge arm resistor and the second bridge arm resistor extend side by side below the reference point.

[0023] Preferably, the semiconductor layer is silicon or silicon carbide.

[0024] Preferably, an insulating substrate is attached to the rear surface of the semiconductor layer.

[0025] This application also claims a method for fabricating the aforementioned full-bridge semiconductor strain gauge, comprising the steps of: providing an insulating substrate; attaching a semiconductor layer to the front surface of the insulating substrate; performing ion implantation from the front surface of the semiconductor layer to form the resistance strip; depositing the metal layer and the resistance protection layer on the front surface of the semiconductor layer; removing excess portions by etching; and thinning the insulating substrate to a suitable thickness.

[0026] The full-bridge semiconductor strain gauge of this application can reduce the number of pads from five to four compared with the prior art, while also reducing the overall width and thus reducing costs. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a Wheatstone full-bridge circuit.

[0028] Figure 2 , Figure 3 This is a schematic diagram of the structure of an existing half-bridge silicon strain gauge and its arrangement on the surface of a plate-shaped elastomer.

[0029] Figure 4 This is a schematic diagram of an existing full-bridge silicon strain gauge;

[0030] Figure 5 This is a schematic diagram of a full-bridge semiconductor strain gauge according to a first preferred embodiment of this application;

[0031] Figure 6 A perspective view of a full-bridge semiconductor strain gauge according to another preferred embodiment of this application;

[0032] Explanation of reference numerals in the figures: 100, Semiconductor strain gauge; 11, Effective resistance portion; 12, Ineffective resistance portion; 1, Semiconductor layer; 2a, High strain region; 2, Metal layer; 3, Insulating substrate; 11a, First resistance arm; 11b, Second resistance arm; 11c, Third resistance arm; 11d, Fourth resistance arm; 12a, First lateral connection portion; 12b, Second lateral connection portion; 12c, Third lateral connection portion; 13a, First covering portion; 13b, Second covering portion; 13c, Third covering portion; 21a, First resistance arm; 21b, Second resistance arm; 21c, Third resistance arm; 21d, Fourth resistance arm; 23a, First covering portion; 23b, Second covering portion Part; 23c, Third Covering Part; 22a, First Lateral Connecting Part; 22b, Second Lateral Connecting Part; 22c, Third Lateral Connecting Part; 41a, First Resistor Arm; 41b, Second Resistor Arm; 41c, Third Resistor Arm; 41d, Fourth Resistor Arm; 43a, First Covering Part; 43b, Second Covering Part; 43c, Third Covering Part; 42a, First Lateral Connecting Part; 42b, Second Lateral Connecting Part; 42c, Third Lateral Connecting Part; 51a, First Pad Base; 51, First Pad; 52a, Second Pad Base; 52, Second Pad; 53a, Third Pad Base; 53, Third Pad; 54a, Fourth Pad Base; 54, Fourth Pad; Detailed Implementation

[0033] The technical solution of this application will now be clearly and completely described with reference to the accompanying drawings. The following embodiments are exemplary and are only used to explain this application, and should not be construed as limiting this application. In the following description, the same reference numerals are used to denote the same or equivalent elements, and repeated descriptions are omitted.

[0034] In the description of this application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this application is in use, or the orientation or positional relationship commonly understood by those skilled in the art. They are only used to facilitate the description of this application and to simplify the description, and are not intended to indicate or imply that the equipment or component referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0035] Furthermore, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0036] It should also be further understood that the term "and / or" as used in this application specification and the corresponding claims refers to any combination of one or more of the listed items, as well as all possible combinations.

[0037] like Figure 5 As shown, the full-bridge semiconductor strain gauge 100 of this embodiment includes a semiconductor layer 1 disposed along the front-rear direction in the thickness direction and a metal layer 2 attached to the front surface of the semiconductor layer 1. The semiconductor layer 1 forms four pad bases 51a to 54a and bridge arm resistors R1 to R4 extending between them to form a Wheatstone full bridge. The bridge arm resistors R1 to R4 extend only in two orthogonal directions (the X and Y directions of a rectangular coordinate system with a reference point O as the origin, as shown in the figure) and form a closed-loop structure through the pad bases 51a to 54a. Each bridge arm resistor R1 to R4 includes an effective resistance portion 11 extending in the Y direction and a lateral connecting portion 12 extending in the X direction. The lateral connecting portion 12 and the front surfaces of the four pad bases 51a to 54a are covered with a covering portion that is part of the metal layer 2. Since the resistivity of metal layer 2 is much smaller than that of the bridge arm resistance, it is connected in parallel with the lateral connection portion 12 attached to the rear side, so that this portion does not contribute to the resistance value of the bridge arm. The covering portion on the pad bases 51a to 54a serves as pads 51 to 54 for connection to the outside via leads. The first pad bases 51 to 54 cover most of the corresponding pad bases 51a to 54a, or cover their entire front surface. The material of the aforementioned metal layer can be aluminum, gold, platinum, or other known suitable metals.

[0038] In the rectangular coordinate system (X,Y) with reference point O as the origin, for ease of explanation and accurate expression, as follows: Figure 5As shown, the "vertical" and "left-right" directions refer to the X direction, and the "horizontal" and "up-down" directions refer to the Y direction. "Left" is the -X direction, "right" is the +X direction, "up" is the +Y direction, and "down" is the -Y direction. The first bridge arm resistor R1 is located in the second quadrant, that is, above and to the left of the reference point O. The two ends of the first bridge arm resistor R1 extend to the first pad base 51a and the fourth pad base 54a, respectively. The first pad base 51a and the fourth pad base 54a are respectively arranged on the left and right sides of the reference point O. The first bridge arm resistor R1 is led out from the fourth pad base 54a, and in the second quadrant, it extends upward to form the first resistor bar 11a, extends to the left to form the first lateral connection portion 12a, extends downward to form the second resistor bar 11b, extends to the left to form the second lateral connection portion 12b, extends upward to form the third resistor bar 11c, extends to the left to form the second lateral connection portion 12c, and extends downward to form the fourth resistor bar 11d before connecting to the first pad base 51a.

[0039] The third bridge arm resistor R3 is located in the first quadrant and is preferably symmetrically arranged with R1. Specifically, the two ends of the third bridge arm resistor R3 are connected to the third pad base 53a and the second pad base 52a. The third pad base 53a and the second pad base 52a are respectively arranged on the left and right sides of the reference point O. The first pad base 51a is connected to the upper left of the fourth pad base 54a, and the second pad base 52a is located to the upper right of the third pad base 53a. The third bridge arm resistor R3 is led out from the third pad base 53a. In the first quadrant, it extends upward to form a first resistor bar 11a, extends to the left to form a first lateral connecting portion 12a, extends downward to form a second resistor bar 11b, extends to the left to form a second lateral connecting portion 12b, extends upward to form a third resistor bar 11c, extends to the left to form a third lateral connecting portion 12c, and extends downward to form a fourth resistor bar 11d before connecting to the second pad base 52a.

[0040] The second bridge arm resistor R2 and the fourth bridge arm resistor R4 are both located in the third and fourth quadrants, respectively. The second bridge arm resistor R2 is connected between the first pad base 51a and the second pad base 52a. The bridge arm resistor R2 is led out from the first pad base 51a on the left side, and extends downward to form a first resistor bar 21a, extends to the right to form a first lateral connection portion 22a, extends upward to form a second resistor bar 21b, extends to the right to form a second lateral connection portion 22b, extends downward to form a third resistor bar 21c, extends to the right to form a third lateral connection portion 22c, and extends upward to form a fourth resistor bar 21d before connecting to the second pad base 52a.

[0041] The second bridge arm resistor R4 is connected between the fourth pad base 54a and the third pad base 53a. It extends from the bridge arm resistor R2 from the fourth pad base 54a on the left side and extends side by side with the fourth bridge arm resistor R4 from the first pad base 51a on the left side, with the same turning sequence and direction. Specifically, it extends downward to form the first resistor bar 41a, extends to the right to form the first lateral connection part 42a, extends upward to form the second resistor bar 41b, extends to the right to form the second lateral connection part 42b, extends downward to form the third resistor bar 41c, extends to the right to form the third lateral connection part 42c, and extends upward to form the fourth resistor bar 41d, which is then connected to the third pad base 53a.

[0042] In this design, the fourth bridge arm resistor R4 is surrounded from below by the second bridge arm resistor R2. An opening 6 is left between the first pad base 51a and the second pad base 52a to allow a first resistor arm 11a to be led out from the fourth pad base 54a and the third pad base 53a respectively. Compared to the bridge arm resistors R1 to R4, the corresponding pad bases 51a to 54a are located on the side closer to the reference point O, or in other words, the lateral connections are all located on the upper and lower outer sides of the four pad bases 51a to 54a.

[0043] Preferably, the initial resistance values ​​(resistance values ​​without strain) of the first bridge arm resistor R1 and the third bridge arm resistor R3 are the same; more preferably, the first bridge arm resistor R1 and the third bridge arm resistor R3 are completely symmetrical from left to right.

[0044] Preferably, the initial resistance values ​​of the second bridge arm resistor R2 and the fourth bridge arm resistor R4 are the same, and they can also be the same as the resistance values ​​of the first bridge arm resistor R1 and the third bridge arm resistor R3. When the widths of the resistor bars of bridge arm resistors R1 to R4 are the same, it means that the total length of the effective resistance portion of bridge arm resistors R1 to R4 is also the same. Specifically, the second pad 52 can be extended downwards to be flush with the lower end of the third pad 53, and the right end of the third cover portion 23c can be extended upwards to be flush with the upper end of the third cover portion 43c, so that the lengths of the fourth resistor bar 21d and the fourth resistor bar 41d are correspondingly the same; similarly, the right end of the second cover portion 43b can be extended downwards to be flush with the lower end of the second lateral connecting portion 22b, and the left end of the third lateral connecting portion 22c can be extended upwards to be flush with the upper end of the third lateral connecting portion 42c. Similarly, the left and right ends of the first cover portion 23a extend upwards and are flush with the upper end of the third cover portion 43c, respectively.

[0045] The semiconductor strain gauge 100 of this embodiment occupies only eight columns of resistor bars, and its total width is 2W1+W3, which is smaller than the total width 2W1+W2 of the full-bridge semiconductor strain gauge 100 in the prior art. Therefore, the semiconductor wafer area used is smaller, and only four pads are needed to form a connection with the external circuit, which can reduce the number of bonding wires from five to four.

[0046] Preferably, all resistor strips have the same width and are arranged on eight parallel vertical lines, which are preferably equidistant. For example, the resistor strips 11a to 11d of the first bridge arm resistor R1 are arranged sequentially on the eighth to fifth vertical lines, the resistor strips 11a to 11d of the third bridge arm resistor R3 are arranged sequentially on the fifth to eighth vertical lines, the resistor strips of the second bridge arm resistor R2 are arranged sequentially on the first, fourth, fifth, and eighth vertical lines, and the resistor strips of the fourth bridge arm resistor R4 are arranged sequentially on the second, third, sixth, and seventh vertical lines. Furthermore, the bridge arm resistors R1 to R4 all form a "U"-shaped bend at the three transverse connection points. Preferably, the second bridge arm resistor R2 extends parallel to the fourth bridge arm resistor R4 below it.

[0047] In this embodiment, the semiconductor strain gauge 100 can be aligned with a longitudinally extending centerline Pm passing through the central strain point Pc during use and installation. The semiconductor layer 1 can be made of silicon or silicon carbide, or other semiconductor materials with piezoresistive effect.

[0048] like Figure 6 As shown, in some other preferred embodiments, preferably, the semiconductor layer 1 can also be disposed on an insulating substrate 3, which can be glass or the like. This can improve the mechanical properties of the semiconductor strain gauge and eliminate the need for a supporting silicon strip. A method for fabricating a full-bridge semiconductor strain gauge with an insulating substrate 3 includes the following steps: 1. Providing an insulating substrate 3 and attaching the semiconductor layer 1 to the front surface of the insulating substrate 3; 2. Performing ion implantation from the front surface of the semiconductor layer 1 to form the resistance strip (a protective layer is first formed before ion implantation and then removed after implantation); 3. Depositing a metal layer 2 and a resistance protection layer (e.g., an oxide layer, a nitride layer) on the front surface of the semiconductor layer 1; 4. Removing excess portions by etching; 5. Thinning the insulating substrate 3 to a suitable thickness.

[0049] Understandably, in other solutions, the bridge arm resistors R1 to R4 can be bent more times. For example, the bridge arm resistors R1 and R3 can be bent to form four "U" bends, five "U" bends, or more "U" bends, etc. Or, without considering the area utilization of the semiconductor wafer, they can be bent fewer times. For example, the third bridge arm resistor R3 can be extended from the left side to the third lateral connection 12c, and the second pad 52 can be extended upward and connected to the third cover 13c.

[0050] The scope of this disclosure is not limited by the detailed description, but by the claims and their equivalents, and all variations within the scope of the claims and their equivalents are to be included in this disclosure.

Claims

1. A full-bridge semiconductor strain gauge, comprising, characterized in that, include: The semiconductor layer (1) is arranged in the front-to-back direction in the thickness direction, including four pad bases (51a to 54a) and four bridge arm resistors (R1 to R4) forming a Wheatstone full bridge. The four pad bases (51a to 54a) include a fourth pad base (54a) and a third pad base (53a) located on the left and right sides of a reference point (O), respectively, a first pad base (51a) located on the upper left side of the fourth pad base (54a), and a second pad base (52a) located on the upper right side of the third pad base (53a). The four bridge arm resistors (R1 to R4) include a first bridge arm resistor (R1) located to the upper left of the reference point (O) and extending to the first pad base (51a) and the fourth pad base (54a) at both ends, a third bridge arm resistor (R3) located to the upper right of the reference point (O) and extending to the third pad base (53a) and the second pad base (52a) at both ends, a fourth bridge arm resistor (R4) located below the reference point (O) and extending to the fourth pad base (54a) and the third pad base (53a) at both ends, and a second bridge arm resistor (R2) located below the reference point (O) and extending to the first pad base (51a) and the second pad base (52a) at both ends; wherein, each of the four bridge arm resistors (R1 to R4) includes a plurality of resistor bars extending vertically and sequentially connected and a plurality of lateral connecting portions extending horizontally and connecting to two adjacent resistor bars; The metal layer (2) attached to the front surface of the semiconductor layer (1) includes four pads (51-54) respectively covering the front surface of the four pad bases (51a-54a) and a plurality of covering portions respectively covering the front surface of the lateral connection portion. Among them, the resistor strips are distributed on multiple vertical lines that extend vertically and are spaced apart horizontally. The second bridge arm resistor (R2) surrounds the fourth bridge arm resistor (R4) from the bottom. The lateral connection parts are all located on the upper and lower outer sides of the four pad bases (51a~54a).

2. The full-bridge semiconductor strain gauge according to claim 1, characterized in that, The multiple vertical lines are set at equal intervals.

3. The full-bridge semiconductor strain gauge according to claim 2, characterized in that, The resistor bars are all the same width.

4. The full-bridge semiconductor strain gauge according to claim 1, characterized in that, The first bridge arm resistor (R1) and the third bridge arm resistor (R3) are arranged symmetrically on the left and right.

5. The full-bridge semiconductor strain gauge according to claim 1, characterized in that, The total length of the resistor strip for each bridge arm resistor (R1 to R4) is the same as the total length of the resistor strip for the other bridge arm resistors.

6. The full-bridge semiconductor strain gauge according to claim 1, characterized in that, Each of the four bridge arm resistors (R1 to R4) includes four resistor bars and three lateral connecting parts connecting every two adjacent resistor bars. The four resistor bars form a "U" shaped bend at the three lateral connecting parts.

7. The full-bridge semiconductor strain gauge according to claim 6, characterized in that, There are a total of eight vertical lines. The four resistor bars of the first bridge arm resistor (R1) are arranged sequentially on the first to fourth vertical lines, the four resistor bars of the third bridge arm resistor (R3) are arranged sequentially on the fifth to eighth vertical lines, the four resistor bars of the second bridge arm resistor (R2) are arranged sequentially on the first, fourth, fifth and eighth vertical lines, and the four resistor bars of the fourth bridge arm resistor (R4) are arranged sequentially on the second, third, sixth and seventh vertical lines. The fourth bridge arm resistor (R4) and the second bridge arm resistor (R2) extend side by side below the reference point (O).

8. The full-bridge semiconductor strain gauge according to claim 1, characterized in that, The semiconductor layer (1) is silicon or silicon carbide.

9. The full-bridge semiconductor strain gauge according to claim 1, characterized in that, An insulating substrate (3) is attached to the rear surface of the semiconductor layer (1).

10. A method for fabricating a full-bridge semiconductor strain gauge as described in claim 9, characterized in that, Including the following steps: An insulating substrate (3) is provided, and a semiconductor layer (1) is attached to the front surface of the insulating substrate (3); Ion implantation is performed from the front surface of the semiconductor layer (1) to form the resistance strip; The metal layer (2) and the resistor protection layer are deposited on the front surface of the semiconductor layer (1); Remove excess material by etching; The insulating substrate (3) is thinned to a suitable thickness.

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