阅读说明：本技术 一种高精度角度传感器敏感结构及其加工方法 (High-precision angle sensor sensitive structure and processing method thereof ) 是由 王振兴 于 2021-01-07 设计创作，主要内容包括：本发明涉及一种高精度角度传感器敏感结构及其加工方法,基于电容数字转换器(CDC)技术,使得在角度测量应用中使用高性能电容检测成为可能。本发明采用的技术方案是：一种高精度角度传感器敏感结构,其特征在于,包括底层电路板、中层电路板和上层电路板；所述底层电路板的底面接地,用于屏蔽干扰；所述底层电路板包括底层焊接面、CDC-A极片和CDC-B极片；所述底层焊接面上设有CDC-A激励输出极和CDC-B激励输出极；所述CDC-A激励输出极和CDC-B激励输出极与激励源连接。(The invention relates to a high-precision angle sensor sensitive structure and a processing method thereof, which are based on a capacitance-to-digital converter (CDC) technology and enable high-performance capacitance detection to be used in angle measurement application. The technical scheme adopted by the invention is as follows: a high-precision angle sensor sensitive structure is characterized by comprising a bottom circuit board, a middle circuit board and an upper circuit board; the bottom surface of the bottom layer circuit board is grounded and used for shielding interference; the bottom circuit board comprises a bottom welding surface, a CDC-A pole piece and a CDC-B pole piece; a CDC-A excitation output electrode and a CDC-B excitation output electrode are arranged on the bottom welding surface; and the CDC-A excitation output electrode and the CDC-B excitation output electrode are connected with an excitation source.)

1. A high-precision angle sensor sensitive structure is characterized by comprising a bottom circuit board (1), a middle circuit board (2) and an upper circuit board (3);

the bottom surface of the bottom layer circuit board is grounded and used for shielding interference; the bottom circuit board comprises a bottom welding surface (13), a CDC-A pole piece (11) and a CDC-B pole piece (12); a CDC-A excitation output electrode (111) and a CDC-B excitation output electrode (121) are arranged on the bottom welding surface; the CDC-A excitation output electrode and the CDC-B excitation output electrode are connected with an excitation source;

the center of the middle layer circuit board is hollowed, and the periphery of the middle layer circuit board is a middle layer welding surface (21);

the upper circuit board comprises A⁺(32)、A^-(31)、B⁺(33)、B^-(34) Four quadrants and an upper welding surface (35), the boundary of A + and A-is perpendicular to the boundary of B + and B-; wherein, A is⁺Quadrant and said A^-Quadrant symmetry, B⁺Quadrant and the B^-The quadrants are symmetrically arranged; a is described⁺And A^-The quadrant constitutes positive and negative pole pieces of the first sensor, B⁺And B^-The quadrants form the positive and negative pole pieces of the second sensor; the area of the CDC-A pole piece is more than or equal to the A⁺Plus A^-The area of (d); the area of the CDC-B pole piece is greater than or equal to B⁺Plus B^-The area of (d); and the CDC-A pole piece completely corresponds to the detection pole A input by the first sensor⁺And A^-Said CDC-B pole piece completely corresponds to said detection pole B of said second sensor input⁺And B^-；

The upper layer circuit board, the middle layer circuit board and the bottom layer circuit board are stacked and welded through the bottom layer welding surface, the middle layer welding surface and the upper layer welding surface to form a sandwich type structure, and the center of the sandwich type structure is a cavity (4); the cavity comprises one-half of the cavity volume of the capacitive liquid and the gas bubble.

2. The sensitive structure of a high precision angle sensor of claim 1, wherein the bottom, middle and top circuit boards have positioning points for making the three circuit boards tilt at the same angle.

3. A high precision angle sensor sensitive structure according to claim 1, wherein the outer surface of the bottom and middle circuit boards and the sensor electrodes and capacitive liquid therein are wrapped by a full copper foil.

4. A high precision angle sensor sensitive structure according to claim 1, characterized by, that the bottom circuit board (1) is provided with small holes (5) for injecting a capacitive liquid into the cavity (4).

5. A processing method of a sensitive structure of a high-precision angle sensor comprises the following steps:

manufacturing a bottom circuit board, wherein the bottom surface of the bottom circuit board is grounded and is used for shielding interference; the bottom circuit board comprises a bottom welding surface, a CDC-A pole piece and a CDC-B pole piece; a CDC-A excitation output electrode and a CDC-B excitation output electrode are arranged on the bottom welding surface; the CDC-A excitation output electrode and the CDC-B excitation output electrode are connected with an excitation source;

making a middle layer circuit board, wherein the center of the middle layer circuit board is hollowed, and the periphery of the middle layer circuit board is a middle layer welding surface;

manufacturing an upper circuit board which comprises A⁺、A^-、B⁺And B^-Four quadrants and upper weld faces, A⁺And A^-The boundary of (A) is vertical to the boundary of (B +); the A + quadrant and the A-quadrant are symmetrically arranged, and the B + quadrant and the B-quadrant are symmetrically arranged; the A + and A-quadrants form a positive pole piece and a negative pole piece of the first sensor, and the B + and B-quadrants form a positive pole piece and a negative pole piece of the second sensor; the area of the CDC-A pole piece is larger than or equal to the area of the A + plus the A-; the area of the CDC-B pole piece is larger than or equal to the area of B plus B minus; the CDC-A pole piece completely corresponds to the detection poles A + and A-input by the first sensor, and the CDC-B pole piece completely corresponds to the detection poles B + and B-input by the second sensor;

the welding surfaces of the three circuit boards are stacked and welded by using a tin soldering method, the upper layer circuit board, the middle layer circuit board and the bottom layer circuit board after welding form a sandwich structure, and the center of the sandwich structure is a cavity.

And forming a small hole (5) in the bottom layer circuit board, injecting flowable capacitive liquid into the cavity through the small hole, wherein the volume of the injected capacitive liquid is one half of that of the cavity, sealing the small hole by using glue or soldering tin, and generating a bubble in the cavity because the cavity is not filled.

6. A method for processing a sensitive structure of a high precision angle sensor according to claim 5, characterized by further comprising the steps of:

and processing positioning points at the same positions of the bottom circuit board, the middle circuit board and the upper circuit board, so that the inclination angles of the three circuit boards are completely the same.

7. A method for processing a sensitive structure of a high precision angle sensor according to claim 5, characterized by further comprising the steps of: and the outer surfaces of the bottom layer circuit board and the middle layer circuit board, the sensor electrode and the capacitive liquid are wrapped by the whole copper foil.

Technical Field

The invention relates to a high-precision angle sensor sensitive structure and a processing method thereof, belonging to the technical field of measurement.

Background

When measuring a non-electrical quantity by an electrical measurement method, the non-electrical quantity to be measured must first be converted into an electrical quantity and then input. An element that converts a non-electrical quantity into an electrical quantity is generally called a transformer; a sensor is a related conversion device designed according to the characteristics of different non-electrical quantities, and a sensor for converting a measured mechanical quantity (such as displacement, force, speed, and the like) into a capacitance change is a capacitive sensor.

From the perspective of energy conversion, the capacitive transducer is a passive transducer, and needs to convert the measured mechanical quantity into voltage or current, and then amplify and process the voltage or current. Linear displacement, angular displacement, interval, distance, thickness, stretching, compression, expansion, deformation and the like in the mechanical quantity are not closely related to the length; these quantities are measured by length or length ratio, and the correlation between the measurement methods is also very close. In addition, under some conditions, the mechanical quantities change slowly, the change range is extremely small, if the extremely small distance or displacement is required to be measured, the high resolution is required, other sensors are difficult to realize the high resolution requirement, and the resolution of the differential transformer sensor commonly used in the precision measurement only reaches the order of magnitude of 1-5 μm; and a capacitance micrometer has the resolution of 0.01 mu m, is improved by two orders of magnitude compared with the resolution of the capacitance micrometer, and has the maximum measuring range of 100 +/-5 mu m, so that the capacitance micrometer is favored in precise small displacement measurement.

For the measurement of these mechanical quantities, especially slowly changing or minute quantities, it is generally appropriate to use capacitive sensors for detection, mainly such sensors have the following outstanding advantages:

(1) the measurement range is large, and the relative change rate can exceed 100 [% ];

(2) the sensitivity is high, if the ratio transformer bridge is used for measurement, the relative variation can reach 10-7 orders of magnitude;

(3) the dynamic response is fast, and the high-frequency characteristic is suitable for dynamic measurement and static measurement due to small movable mass and high natural frequency.

(4) The stability is good because the polar plates of the capacitor are mostly made of metal materials, and the linings between the polar plates are mostly made of inorganic materials such as air, glass, ceramics, quartz and the like; therefore, the device can work for a long time under high-temperature, low-temperature strong magnetic fields and strong radiation, and particularly solves the detection problem under the high-temperature and high-pressure environment.

Capacitive-to-digital converters (CDC) are currently an application technology suitable for detection. The single channel AD7745 and the dual channel AD7746 are both high-resolution sigma-delta capacitance-to-digital converters, and can measure the capacitance directly connected with the input end. These devices have high resolution (21 bit effective resolution and 24 bit no-missing code), high linearity (+ -0.01%) and high accuracy (factory calibration to + -4 fF), and are well suited for detecting liquid levels, positions, pressures and other physical parameters. These devices have complete functionality, integrating a multiplexer, a stimulus source, a DAC for capacitance, a temperature sensor, a reference voltage source, a clock generator, control and calibration logic, an I2C compatible serial interface, and a high precision converter core that integrates a second order sigma delta type charge balance modulator and a third order digital filter. The converter serves as both a CDC of the capacitive input and an ADC of the voltage input.

The measured capacitance Cx is connected between the excitation source and the sigma-delta modulator input. A square wave excitation signal is applied at Cx during the transition. The modulator will sample the charge flowing through Cx without interruption and convert it to a stream of 0 s and 1 s. The density of the modulator output 1 is processed by a digital filter to determine the capacitance value. The filter output is scaled by the calibration factor. The final value can then be read by the external host through the serial interface.

Disclosure of Invention

The invention aims to provide a high-precision angle sensor sensitive structure and a processing method thereof, which are based on a capacitance-to-digital converter (CDC) technology and enable high-performance capacitance detection to be used in angle measurement application.

The technical scheme adopted by the invention is as follows: a high-precision angle sensor sensitive structure is characterized by comprising a bottom circuit board, a middle circuit board and an upper circuit board;

the bottom surface of the bottom layer circuit board is grounded and used for shielding interference; the bottom circuit board comprises a bottom welding surface, a CDC-A pole piece and a CDC-B pole piece; a CDC-A excitation output electrode and a CDC-B excitation output electrode are arranged on the bottom welding surface; the CDC-A excitation output electrode and the CDC-B excitation output electrode are connected with an excitation source;

the center of the middle layer circuit board is hollowed, and the periphery of the middle layer circuit board is a middle layer welding surface;

the upper circuit board comprises four quadrants of A +, A-, B + and B-and an upper welding surface, and the boundary of the A + and the A-is vertical to the boundary of the B + and the B-; the A + quadrant and the A-quadrant are symmetrically arranged, and the B + quadrant and the B-quadrant are symmetrically arranged; the A + and A-quadrants form a positive pole piece and a negative pole piece of the first sensor, and the B + and B-quadrants form a positive pole piece and a negative pole piece of the second sensor; the area of the CDC-A pole piece is larger than or equal to the area of the A + plus the A-; the area of the CDC-B pole piece is larger than or equal to the area of B plus B minus; the CDC-A pole piece completely corresponds to the detection poles A + and A-input by the first sensor, and the CDC-B pole piece completely corresponds to the detection poles B + and B-input by the second sensor;

the upper layer circuit board, the middle layer circuit board and the bottom layer circuit board are stacked and welded through the bottom layer welding surface, the middle layer welding surface and the upper layer welding surface to form a sandwich-type structure, and the center of the sandwich-type structure is a cavity; the cavity comprises one-half of the cavity volume of the capacitive liquid and the gas bubble.

Furthermore, positioning points are arranged on the bottom circuit board, the middle circuit board and the upper circuit board and used for enabling the inclination angles of the three circuit boards to be completely the same.

Further, the outer surfaces of the bottom circuit board and the middle circuit board, the sensor electrode and the capacitive liquid are wrapped by the whole copper foil.

Further, the bottom layer circuit board (1) is provided with a small hole (5) for injecting a capacitive liquid into the cavity (4).

A processing method of a sensitive structure of a high-precision angle sensor comprises the following steps:

manufacturing a bottom circuit board, wherein the bottom surface of the bottom circuit board is grounded and is used for shielding interference; the bottom circuit board comprises a bottom welding surface, a CDC-A pole piece and a CDC-B pole piece; a CDC-A excitation output electrode and a CDC-B excitation output electrode are arranged on the bottom welding surface; the CDC-A excitation output electrode and the CDC-B excitation output electrode are connected with an excitation source;

making a middle layer circuit board, wherein the center of the middle layer circuit board is hollowed, and the periphery of the middle layer circuit board is a middle layer welding surface;

manufacturing an upper circuit board, wherein the upper circuit board comprises four quadrants of A +, A-, B + and B-and an upper welding surface, and a boundary of the A + and the A-is vertical to a boundary of the B + and the B-; the A + quadrant and the A-quadrant are symmetrically arranged, and the B + quadrant and the B-quadrant are symmetrically arranged; the A + and A-quadrants form a positive pole piece and a negative pole piece of the first sensor, and the B + and B-quadrants form a positive pole piece and a negative pole piece of the second sensor; the area of the CDC-A pole piece is larger than or equal to the area of the A + plus the A-; the area of the CDC-B pole piece is larger than or equal to the area of B plus B minus; the CDC-A pole piece completely corresponds to the detection poles A + and A-input by the first sensor, and the CDC-B pole piece completely corresponds to the detection poles B + and B-input by the second sensor;

the welding surfaces of the three circuit boards are stacked and welded by using a tin soldering method, the upper layer circuit board, the middle layer circuit board and the bottom layer circuit board after welding form a sandwich structure, and the center of the sandwich structure is a cavity.

And forming a small hole on the bottom layer circuit board, injecting flowable capacitive liquid into the cavity through the small hole, wherein the volume of the injected capacitive liquid is one half of that of the cavity, sealing the small hole by using glue or soldering tin, and generating a bubble in the cavity because the cavity is not filled.

Further, the method also comprises the following steps:

and processing positioning points at the same positions of the bottom circuit board, the middle circuit board and the upper circuit board, so that the inclination angles of the three circuit boards are completely the same.

Further, the method also comprises the following steps: and the outer surfaces of the bottom layer circuit board and the middle layer circuit board, the sensor electrode and the capacitive liquid are wrapped by the whole copper foil.

The working principle of the invention is that when the mounting carrier of the sensitive structure of the high-precision angle sensor inclines, the position of the air bubble deviates, so that the A + and A-capacitances are asymmetric, and the ratio of the A + to the A-capacitances can be directly used for feeding back the change of the inclination angle.

The invention has the beneficial effects that: the invention provides a brand-new high-precision angle sensor sensitive structure and a processing method thereof.

Drawings

FIG. 1 is a schematic view of the overall structure of the present invention;

FIG. 2 is a schematic view of a bottom-layer circuit board structure according to the present invention;

FIG. 3 is a schematic view of an upper circuit board structure according to the present invention;

FIG. 4 is a schematic view of a middle layer circuit board structure according to the present invention.

In the figure, 1, a bottom layer circuit board; 2. a middle layer circuit board; 3. an upper layer circuit board; 4. a cavity; 5. a small hole; 6. positioning points; 11. CDC-A pole piece; 12. CDC-B pole piece; 13. a bottom layer welding surface; 111. CDC-A excitation output pole; 121. CDC-B excitation output pole; 61. a first anchor site; 62. a second positioning point; 31. a-quadrant; 32. a + quadrant; 33, B + quadrant, 34, B-quadrant; 35. an upper layer welding surface; 21. and (6) welding the middle layer.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The terms "first", "second" and "third" in the present invention are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first," "second," or "third" may explicitly or implicitly include at least one of the feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise. All directional indicators (such as up, down, left, right, front, and rear … …) in the embodiments of the present invention are only used to explain the relative positional relationship between the components, the movement, and the like in a specific posture (as shown in the drawings), and if the specific posture is changed, the directional indicator is changed accordingly. Furthermore, the terms "include" and "have," as well as any variations thereof, are intended to cover non-exclusive inclusions.

Reference herein to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment of the invention. The appearances of the phrase in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments. It is explicitly and implicitly understood by one skilled in the art that the embodiments described herein can be combined with other embodiments.

As shown in figures 1, 2, 3 and 4,

a high-precision angle sensor sensitive structure comprises a bottom circuit board (1), a middle circuit board (2) and an upper circuit board (3);

the bottom surface of the bottom layer circuit board is grounded and used for shielding interference; the bottom circuit board comprises a bottom welding surface (13), a CDC-A pole piece (11) and a CDC-B pole piece (12); a CDC-A excitation output electrode (111) and a CDC-B excitation output electrode (121) are arranged on the bottom welding surface; the CDC-A excitation output electrode and the CDC-B excitation output electrode are connected with an excitation source;

the center of the middle layer circuit board (2) is hollowed, and the periphery of the middle layer circuit board is a middle layer welding surface (21);

the upper circuit board comprises four quadrants of A + (32), A- (31), B + (33) and B- (34) and an upper welding surface (35), and the boundary of A + and A-is vertical to the boundary of B + and B-; the A + quadrant and the A-quadrant are symmetrically arranged, and the B + quadrant and the B-quadrant are symmetrically arranged; the A + and A-quadrants form a positive pole piece and a negative pole piece of the first sensor, and the B + and B-quadrants form a positive pole piece and a negative pole piece of the second sensor; the area of the CDC-A pole piece is larger than or equal to the area of the A + plus the A-; the area of the CDC-B pole piece is larger than or equal to the area of B plus B minus; the CDC-A pole piece completely corresponds to the detection poles A + and A-input by the first sensor, and the CDC-B pole piece completely corresponds to the detection poles B + and B-input by the second sensor;

the upper layer circuit board, the middle layer circuit board and the bottom layer circuit board are stacked and welded through the bottom layer welding surface, the middle layer welding surface and the upper layer welding surface to form a sandwich type structure, and the center of the sandwich type structure is a cavity (4); the cavity comprises one-half of the cavity volume of the capacitive liquid and the gas bubble.

Furthermore, positioning points (61) and (62) are arranged on the bottom circuit board, the middle circuit board and the upper circuit board and used for enabling the inclination angles of the three circuit boards to be completely the same.

Further, the outer surfaces of the bottom circuit board and the middle circuit board, the sensor electrode and the capacitive liquid are wrapped by the whole copper foil.

Further, the bottom layer circuit board (1) is provided with a small hole (5) for injecting a capacitive liquid into the cavity (4).

A processing method of a sensitive structure of a high-precision angle sensor comprises the following steps:

manufacturing a bottom circuit board, wherein the bottom surface of the bottom circuit board is grounded and is used for shielding interference; the bottom circuit board comprises a bottom welding surface, a CDC-A pole piece and a CDC-B pole piece; a CDC-A excitation output electrode and a CDC-B excitation output electrode are arranged on the bottom welding surface; the CDC-A excitation output electrode and the CDC-B excitation output electrode are connected with an excitation source;

making a middle layer circuit board, wherein the center of the middle layer circuit board is hollowed, and the periphery of the middle layer circuit board is a middle layer welding surface;

manufacturing an upper circuit board, wherein the upper circuit board comprises four quadrants of A +, A-, B + and B-and an upper welding surface, and a boundary of the A + and the A-is vertical to a boundary of the B + and the B-; the A + quadrant and the A-quadrant are symmetrically arranged, and the B + quadrant and the B-quadrant are symmetrically arranged; the A + and A-quadrants form a positive pole piece and a negative pole piece of the first sensor, and the B + and B-quadrants form a positive pole piece and a negative pole piece of the second sensor; the area of the CDC-A pole piece is larger than or equal to the area of the A + plus the A-; the area of the CDC-B pole piece is larger than or equal to the area of B plus B minus; the CDC-A pole piece completely corresponds to the detection poles A + and A-input by the first sensor, and the CDC-B pole piece completely corresponds to the detection poles B + and B-input by the second sensor;

the welding surfaces of the three circuit boards are stacked and welded by using a tin soldering method, the upper layer circuit board, the middle layer circuit board and the bottom layer circuit board after welding form a sandwich structure, and the center of the sandwich structure is a cavity.

And forming a small hole on the bottom layer circuit board, injecting flowable capacitive liquid into the cavity through the small hole, wherein the volume of the injected capacitive liquid is one half of that of the cavity, sealing the small hole by using glue or soldering tin, and generating a bubble in the cavity because the cavity is not filled.

Further, the method also comprises the following steps:

and processing positioning points at the same positions of the bottom circuit board, the middle circuit board and the upper circuit board, so that the inclination angles of the three circuit boards are completely the same.

Further, the method also comprises the following steps: and the outer surfaces of the bottom layer circuit board and the middle layer circuit board, the sensor electrode and the capacitive liquid are wrapped by the whole copper foil.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.