A strain gauge integrated structure

Abstract

This invention discloses an integrated strain gauge structure, including a bridge resistance strain gauge module, a gate driver, and an ADC (Analog-to-Digital Converter) module integrated on the same strain gauge. The bridge resistance strain gauge module uses a semiconductor strain gauge. The ADC module is connected to the excitation terminal of the semiconductor strain gauge through the gate driver, controlling the current to excite the semiconductor strain gauge. The signal output terminal of the semiconductor strain gauge is connected to the signal input terminal of the ADC module. The integrated strain gauge structure also includes a base plate and a surface filling material. The strain gauge is placed on the base plate, and the surface filling material encapsulates the chip on the base plate. This invention integrates the bridge resistance strain gauge module, the gate driver, and the ADC module into a single strain gauge structure, connects to external devices through a flexible circuit board, and uses high-reliability packaging materials, significantly improving the integration of the strain measurement system, reducing space occupation, and meeting the application requirements of miniaturization and high-density integration.

Description

Technical Field

[0001] This utility model relates to the field of strain gauge packaging, and in particular to a strain gauge integrated structure that improves the integration of strain measurement systems. Background Technology

[0002] Strain gauges, as core sensing elements, are widely used in the measurement of physical quantities such as stress, strain, and pressure. Traditional strain gauges typically consist of a sensing grid, a substrate, and leads. Their working principle involves reflecting the deformation of the measured object through changes in the resistance of the sensing grid. However, traditional strain gauges suffer from the following technical problems.

[0003] 1. Existing strain gauges typically only contain a sensing grid structure, requiring an external, independent bridge resistor excitation circuit, signal amplifier, and analog-to-digital converter (ADC) module to complete signal acquisition and digitization. This discrete design results in high circuit complexity, difficult wiring, and susceptibility to external noise interference, affecting measurement accuracy.

[0004] 2. In traditional solutions, strain gauges and subsequent signal processing units (such as ADCs and drive circuits) need to be connected through flexible circuit boards or wires, which takes up a lot of space and makes it difficult to meet the application requirements of miniaturization and high-density integration (such as wearable devices and embedded sensors).

[0005] 3. The long-term stability of strain gauges under harsh environments (such as high temperature and vibration) depends on the packaging material and structural design. Existing products mostly use a single material for packaging, which has problems such as mismatch in thermal expansion coefficients and insufficient mechanical strength, resulting in decreased reliability.

[0006] 4. Traditional strain gauges require adhesives or welding to be fixed to the surface of the object being measured, making the installation process cumbersome and subsequent maintenance or replacement costs high. Furthermore, the risk of wiring errors in discrete circuits further increases the difficulty of system integration.

[0007] To address these issues, the industry has proposed several improvements. For example, attempts have been made to integrate strain gauges with simple drive circuits on the same substrate, but this still doesn't achieve complete signal chain integration (e.g., the lack of an ADC module). Another approach uses ceramic substrate packaging, but this is costly and lacks flexibility. Therefore, there is an urgent need for a highly integrated, miniaturized, and environmentally adaptable strain gauge structure to simplify measurement system design and improve reliability. Utility Model Content

[0008] To address the aforementioned technical bottlenecks, this invention proposes a structure that integrates a bridge-type resistance strain gauge module, a gate driver, and an ADC analog-to-digital converter module into a single strain gauge. It connects to external devices via a flexible circuit board and employs highly reliable packaging materials, significantly improving the integration and practicality of the strain measurement system.

[0009] The technical solution of this utility model is:

[0010] An integrated strain gauge structure includes a bridge resistance strain gauge module, a gate driver, and an ADC analog-to-digital converter module integrated on the same strain gauge. The bridge resistance strain gauge module uses a semiconductor strain gauge. The ADC analog-to-digital converter module is connected to the excitation terminal of the semiconductor strain gauge through the gate driver to control the current to excite the semiconductor strain gauge. The signal output terminal of the semiconductor strain gauge is connected to the signal input terminal of the ADC analog-to-digital converter module.

[0011] Preferably, the strain gauge integrated structure further includes a base plate and a surface filling material, wherein the strain gauge is placed on the base plate and the surface filling material encloses the chip on the base plate.

[0012] Preferably, the ADC analog-to-digital conversion module is connected to external electronic devices via a flexible circuit board.

[0013] Preferably, the strain gauge integrated structure also integrates an FFC / FPC connector, and the flexible circuit board is connected to the strain gauge integrated structure through the FFC / FPC connector.

[0014] Preferably, the bottom of the base plate is provided with an adhesive surface for bonding to the device to be tested.

[0015] Preferably, the base plate is made of metal sheet.

[0016] Preferably, the surface filling material is one of glass-reinforced epoxy film, polyimide film, or phenolic resin film.

[0017] Preferably, the base plate has a length of 10-15mm and a width of 5-10mm.

[0018] Preferably, the height of the strain gauge integrated structure is less than 1.5 mm.

[0019] Preferably, the gate driver is connected to the excitation terminal of the bridge resistance strain module via an H-bridge circuit. The H-bridge circuit includes four switching transistors Q1, Q2, Q3, and Q4, where Q1 and Q3 are the upper bridge arms, and Q2 and Q4 are the lower bridge arms corresponding to Q1 and Q2, respectively.

[0020] The advantages of this utility model are:

[0021] 1. This utility model integrates a bridge resistance strain gauge module, a gate driver, and an ADC analog-to-digital conversion module into a single strain gauge structure. It connects to external devices through a flexible circuit board and uses high-reliability packaging materials, which significantly improves the integration of the strain measurement system, reduces the space occupied, and meets the application requirements of miniaturization and high-density integration.

[0022] 2. The strain gauge of this utility model adopts an elastic metal base plate and plastic film encapsulation, which overcomes problems such as mismatch of thermal expansion coefficients and insufficient mechanical strength in harsh environments, and maintains long-term reliability.

[0023] 3. The bottom of the base plate of the strain gauge of this invention is provided with an adhesive surface for bonding to the device to be tested. The installation process is simple, and the subsequent maintenance or replacement cost is low. Attached Figure Description

[0024] The present invention will be further described below with reference to the accompanying drawings and embodiments:

[0025] Figure 1 This is a schematic diagram of the main principle of the strain gauge integrated structure of this utility model;

[0026] Figure 2 This is a top view of the integrated strain gauge structure of this utility model.

[0027] Figure 3 This is a front view of the strain gauge integrated structure of this utility model;

[0028] Figure 4 This is a bottom view of the strain gauge integrated structure of this utility model.

[0029] Figure 5 This is a schematic diagram of the strain gauge integrated structure of this utility model;

[0030] Figure 6 This is the schematic diagram of an H-bridge circuit. Detailed Implementation

[0031] like Figure 1 As shown, the strain gauge integrated structure of this utility model includes a bridge resistance strain gauge module, a gate driver, and an ADC analog-to-digital converter module integrated on the same strain gauge. The bridge resistance strain gauge module uses a semiconductor strain gauge. The ADC analog-to-digital converter module is connected to the excitation terminal of the semiconductor strain gauge through the gate driver, controlling the current to excite the semiconductor strain gauge. The signal output terminal of the semiconductor strain gauge is connected to the signal input terminal of the ADC analog-to-digital converter module. The ADC analog-to-digital converter module integrates a signal amplification module, which first amplifies the acquired strain signal and then performs digital conversion.

[0032] like Figure 2-4 As shown, the strain gauge integrated structure also includes a base plate 1 and a surface filling material 2. The strain gauge is placed on the base plate 1, and the surface filling material 2 encapsulates the chip on the base plate 1. In the packaged strain gauge, the ADC analog-to-digital conversion module is connected to an external processor via a flexible circuit board 3. The bottom of the base plate has an adhesive surface for bonding to the device under test, simplifying the installation process and reducing subsequent maintenance or replacement costs.

[0033] The base plate is made of metal sheet. The base plate is 10-15mm long and 5-10mm wide.

[0034] The surface filling material is one of glass-reinforced epoxy film, polyimide film, or phenolic resin film. The height of the integrated strain gauge structure is less than 1.5 mm.

[0035] This utility model strain gauge uses a flexible metal base plate and plastic film encapsulation to overcome problems such as mismatch of thermal expansion coefficients and insufficient mechanical strength in harsh environments, and maintains long-term reliability.

[0036] The strain gauge integrated structure also integrates an FFC / FPC connector, and the flexible circuit board is connected to the strain gauge integrated structure through the FFC / FPC connector.

[0037] This invention integrates a bridge resistance strain gauge module, a gate driver, and an ADC analog-to-digital converter module into a single strain gauge structure. It connects to external devices via a flexible circuit board and uses highly reliable packaging materials, which significantly improves the integration of the strain measurement system, reduces the space occupied, and meets the application requirements of miniaturization and high-density integration.

[0038] like Figure 5 As shown, the strain gauge integrated structure of this utility model mainly includes a bridge-type resistance strain gauge module, a gate driver U2, and an ADC analog-to-digital conversion module U1. The semiconductor strain gauge of the bridge-type resistance strain gauge module is an integrated circuit composed of resistors R39, R40, R43, and R44 connected in a bridge configuration. EXC+_OUT and EXC-_OUT are the positive and negative excitation terminals of the semiconductor strain gauge, and SIG+ and SIG- are the signal output terminals. The gate driver U2 is an isolated gate driver, with output control terminals OUTA and OUTB connected to the positive and negative excitation terminals EXC+_OUT and EXC-_OUT of the semiconductor strain gauge, respectively. FPC2 and FPC1 are FPC connectors.

[0039] like Figure 6 As shown, the gate driver is connected to the excitation terminal of the bridge resistance strain gauge module via an H-bridge circuit. The H-bridge circuit includes four switching transistors Q1, Q2, Q3, and Q4, where Q1 and Q3 form the upper bridge arm, and Q2 and Q4 form the lower bridge arm, respectively connected to Q1 and Q2. The positive and negative excitation terminals EXC+_OUT and EXC-_OUT of the bridge resistance strain gauge module are connected to the positive and negative terminals of the H-bridge circuit, respectively, and the four AIN pins of the ADC analog-to-digital converter module output... , ACX 2. , ACX Signal 1 is connected to the gates of four switching transistors Q1, Q2, Q3, and Q4 respectively, controlling the conduction of phase A or phase B current.

[0040] The ADC analog-to-digital conversion module U1 has an integrated programmable gain amplifier (PGA) and a signal and reference multiplexer, which can support multiple differential signal inputs and reference inputs.

[0041] The above embodiments are only for illustrating the technical concept and features of this utility model, and are intended to enable those skilled in the art to understand the content of this utility model and implement it accordingly. They should not be construed as limiting the scope of protection of this utility model. All modifications made in accordance with the spirit and essence of the main technical solution of this utility model should be included within the scope of protection of this utility model.

Claims

1. A strain gauge integrated structure, characterized in that, The device includes a bridge resistance strain gauge module, a gate driver, and an ADC analog-to-digital converter module integrated on the same strain gauge. The bridge resistance strain gauge module uses a semiconductor strain gauge. The ADC analog-to-digital converter module is connected to the excitation terminal of the semiconductor strain gauge through the gate driver, and controls the current to excite the semiconductor strain gauge. The signal output terminal of the semiconductor strain gauge is connected to the signal input terminal of the ADC analog-to-digital converter module.

2. The strain gauge integrated structure according to claim 1, characterized in that, The strain gauge integrated structure also includes a base plate and a surface filling material. The strain gauge is placed on the base plate, and the surface filling material encloses the chip on the base plate.

3. The strain gauge integrated structure according to claim 2, characterized in that, The ADC analog-to-digital conversion module is connected to external electronic devices via a flexible circuit board.

4. The strain gauge integrated structure according to claim 3, characterized in that, The strain gauge integrated structure also integrates an FFC / FPC connector, and the flexible circuit board is connected to the strain gauge integrated structure through the FFC / FPC connector.

5. The strain gauge integrated structure according to claim 2, characterized in that, The bottom of the base plate is provided with an adhesive surface, which is then bonded to the device to be tested.

6. The strain gauge integrated structure according to claim 2, characterized in that, The base plate is made of metal sheet.

7. The strain gauge integrated structure according to claim 2, characterized in that, The surface filling material is one of glass-reinforced epoxy film, polyimide film, or phenolic resin film.

8. The strain gauge integrated structure according to claim 7, characterized in that, The base plate has a length of 10-15mm and a width of 5-10mm.

9. The strain gauge integrated structure according to claim 8, characterized in that, The height of the strain gauge integrated structure is less than 1.5 mm.

10. The strain gauge integrated structure according to claim 1, characterized in that, The gate driver is connected to the excitation terminal of the bridge resistance strain module through an H-bridge circuit. The H-bridge circuit includes four switching transistors Q1, Q2, Q3, and Q4, where Q1 and Q3 are the upper bridge arms, and Q2 and Q4 are the lower bridge arms that are respectively connected to Q1 and Q2.

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