Printed circuit board spiral coil inductance sensor and method for strong vibration environments

Abstract

The present application relates to printed circuit board processing solenoid coil class inductance sensor technical field, provide a kind of for strong vibration environment's printed circuit board helical coil inductance sensor and method, inductance coil is made of helical line fixed on printed circuit board, helical line is circular ring structure, the layer number of printed circuit board is greater than or equal to 2 even number;Helical line direction includes clockwise direction and counterclockwise direction, the helical line direction of adjacent two layers of printed circuit board is opposite and is connected by the through hole of being opened on printed circuit board head to tail;Different inductance coil is formed by different printed circuit board connection, and inductance sensor is prepared;The width and spacing of helical line are all greater than 0.08mm, and the layer number of helical line can be at most 64 layers.The present application is etched on printed circuit board using printed circuit board process, under vibration and temperature change, the inductance of helical line can be reliably guaranteed, thus it is suitable for inductance sensor in vibration environment.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of sensors, and particularly relates to a printed circuit board spiral coil inductance sensor and method for a strong vibration environment. BACKGROUND

[0002] The conventional process of the enameled wire type inductance sensor generally needs to use epoxy resin glue or a vacuum impregnation process to fix the enameled wires. In the special case of a coil with a large number of turns, thin enameled wires and a requirement for precise inductance sensors, the quality of the inductance sensor is low, and the consistency is poor. If the sensor works in a strong vibration and large temperature change working condition at this time, the enameled wires often have relative motion, generate a large magnetic field interference noise, and affect the test. Although the enameled wire process can be further strengthened to solve the problem of fixing the enameled wires, the yield is still low, the consistency is poor, and the cost is high.

[0003] Patent 202223343308.5-10 layer coil printed circuit board, the essence is to fix the enameled wire inductance coil on the printed circuit board. Patent 201922009699.9-a printed circuit board circuit coil manufacturing tool, the essence is a tool structure. Patent 201420108698.4-high voltage structure of mutual inductance coil printed circuit board, the essence is to provide a high-voltage printed circuit board structure for mutual inductance coil.

[0004] At present, the existing inductance sensor cannot be well applied to a strong vibration environment, and cannot be quickly prepared based on a target inductance value, so it is urgent to research an inductance sensor which is convenient to manufacture, low in cost, stable in use and can be used in a strong vibration environment. SUMMARY

[0005] In view of the deficiencies of the prior art, in order to solve the actual problems of unstable coil fixation and easy magnetic field interference under vibration conditions when winding a multi-turn, thin enameled wire coil inductance in the traditional process, the present application provides a printed circuit board spiral coil inductance sensor and method for a strong vibration environment, which has the advantages of low cost, high consistency and stable reliability.

[0006] To achieve the above purpose, the present application discloses the following technical scheme:

[0007] On the one hand, the present application provides a printed circuit board spiral coil inductance sensor for a strong vibration environment, the inductance coil is composed of a spiral wire fixed on a printed circuit board, the spiral wire is a circular ring structure, and the number of layers of the printed circuit board is an even number greater than or equal to 2.

[0008] The spiral direction of the spiral line includes a clockwise direction and an anticlockwise direction, the spiral directions of two adjacent layers of the printed circuit board are opposite and connected head to tail through a through hole opened on the printed circuit board, the printed circuit board is marked by cutting or silk-screen printing according to the spiral direction, a plurality of inductance coils are formed by connecting a plurality of layers of the printed circuit board, and the target inductance sensor is prepared;

[0009] The width and the pitch of the spiral line are both greater than 0.08 mm;

[0010] A total inductance calculation model is constructed, and the number of layers of the printed circuit board is selected based on a target inductance value;

[0011] The total inductance calculation model is as follows:

[0012] L 总 =nL+2L×(K 12 +K 13 +K 14 …+K 1n +K 23 +K 24 +…+K n(n-1) )

[0013] Wherein, L is a single-layer inductance value, K is an inductance coupling coefficient between different layers, and n is the number of layers of the printed circuit board;

[0014] The single-layer inductance value calculation formula is as follows:

[0015]

[0016] Wherein, μ0=4π10 -7 is a coefficient, N is the number of turns of a single-layer spiral line, d max is the maximum spiral line diameter, and d min is the minimum spiral line diameter;

[0017] The inductance coupling coefficient calculation formula between different layers is as follows:

[0018]

[0019] Wherein, N is the number of turns of the spiral line, X is the distance between the layers of the printed circuit board, and A, B, C and D are fitting coefficients.

[0020] Preferably, A=0.184, B=-0.525, C=1.038, and D=1.001.

[0021] Preferably, the number of layers of the printed circuit board is 2-64 layers.

[0022] Preferably, the thickness of the printed circuit board is 2 mm, 2.5 mm or 3 mm.

[0023] Preferably, the helical line spacing is 0.1±0.05mm.

[0024] Preferably, the helical line width is between 0.25mm-2.5mm.

[0025] Preferably, the inductance and DC resistance of the inductor are adjusted by adjusting the line width, spacing and number of layers of the helical line.

[0026] Preferably, the helical line is etched on the printed circuit board.

[0027] Preferably, the inductance sensor can be used alone for inductive distance measurement or can be connected in multiple for magnetic field modulation environment.

[0028] Another aspect of the present application provides a preparation method of the above-mentioned printed circuit board helical coil inductance sensor for strong vibration environment, comprising the following steps:

[0029] S1, etching a helical line on a printed circuit board, and marking the printed circuit board according to the direction of the helical line;

[0030] S2, determining the number of layers of the printed circuit board according to the target inductance value, specifically:

[0031] Building a total inductance calculation model, and selecting the number of layers of the printed circuit board based on the target inductance value;

[0032] The total inductance calculation model is:

[0033] L 总 =nL+2L×(K 12 +K 13 +K 14 …+K 1n +K 23 +K 24 +…+K n(n-1) )

[0034] Wherein, L is a single-layer inductance value, K is an inductance coupling coefficient between different layers, and n is the number of layers of the printed circuit board;

[0035] The single-layer inductance value calculation formula is as follows:

[0036]

[0037] Wherein, μ0=4π10 -7 is a coefficient, N is the number of turns of a single-layer helical line, d max is the maximum helical line diameter, and d min is the minimum helical line diameter.

[0038] The inductance coupling coefficient calculation formula between different layers is as follows:

[0039]

[0040] Wherein, N is the number of spiral turns, X is the distance between the printed circuit board layers, A, B, C, D are all fitting coefficients;

[0041] S3, select two printed circuit boards with opposite spiral directions to be connected, and the spiral lines of the adjacent two layers of printed circuit boards are connected head to tail through the through holes formed on the printed circuit board;

[0042] S4, based on the number of printed circuit board layers determined in step S2, the multi-layer printed circuit board is sequentially connected according to the method of step S3 to obtain a multi-layer inductance coil, and the target inductance sensor is prepared.

[0043] Compared with the prior art, the present application has the following beneficial effects:

[0044] (1) The present application provides a printed circuit board spiral coil inductance sensor for strong vibration environment, which uses printed circuit board process to etch spiral lines on the printed circuit board to obtain a printed circuit board spiral coil inductance sensor. Under vibration and temperature change conditions, the spiral line inductance can be fixed and reliable, and the precision of the inductance sensor will not be affected by vibration and temperature change. Therefore, it is suitable for various vibration environments.

[0045] (2) The method for preparing an inductance sensor by using a printed circuit board has low mass production cost, high consistency and high yield, and has very high engineering application value compared with traditional schemes.

[0046] (3) The printed circuit board spiral coil inductance sensor for strong vibration environment provided by the present application can adjust the inductance and the direct current impedance of the inductance by adjusting the line width, spacing and number of layers of the spiral line during use. Compared with the traditional process, the enameled wire skeleton needs to be machined, and the method of the present application is more flexible.

[0047] (4) The present application gives a calculation model of total inductance, which can quickly calculate the total inductance value under different line width, spacing and number of layers of the spiral line, so as to quickly obtain the total inductance value. At the same time, the total inductance value required can be obtained, and the line width, spacing and number of layers of the spiral line can be adjusted to quickly obtain the target inductance sensor. BRIEF DESCRIPTION OF DRAWINGS

[0048] Figure 1 It is a schematic diagram of the first layer of the multi-layer printed circuit board of the present application;

[0049] Figure 2 It is a schematic diagram of the adjacent layers of the multi-layer printed circuit board of the present application;

[0050] Figure 3A schematic diagram of the structure size of the printed circuit board inductance according to the present application;

[0051] Figure 4 A schematic diagram of the method according to the present application. DETAILED DESCRIPTION

[0052] Exemplary embodiments, features and aspects of the present application will be described in detail below with reference to the accompanying drawings. The same reference numerals in the drawings denote elements having the same or similar functions. Although various aspects of the embodiments are illustrated in the drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

[0053] In one aspect, the present application provides a printed circuit board spiral coil inductance sensor for strong vibration environment, which comprises an inductance coil, such as Figure 1 and Figure 2 As shown, the inductance coil is composed of a spiral line 1 fixed on a printed circuit board, the spiral line 1 has a circular ring structure, and the number of layers of the printed circuit board is an even number greater than or equal to 2; the spiral direction of the spiral line 1 includes clockwise and counterclockwise directions, the spiral directions of the spiral lines of the adjacent two layers of the printed circuit board are opposite and connected end to end through the through holes 4 opened on the printed circuit board; the number of layers of the printed circuit board 2 is greater than the number of spiral coils. The thickness of the printed circuit board is 2 mm, 2.5 mm or 3 mm. The number of layers of the printed circuit board is 2-60 layers. Figure 1 A schematic diagram of the first layer of the printed circuit board 2 is shown, Figure 2 A schematic diagram of the adjacent layer of the printed circuit board 3 is shown. A plurality of through holes 4 are opened on the printed circuit board.

[0054] In practical applications, the spiral direction of the spiral line 1 includes clockwise and counterclockwise directions, and the printed circuit board is marked by cutting or silk-screen printing, Figure 1 and Figure 2 The cutting chamfer 5 is shown in , a plurality of inductance coils are formed by connecting a plurality of printed circuit boards, and a target inductance sensor is prepared. That is, different inductance coils can be obtained by connecting printed circuit boards with different numbers of layers, and the required target inductance sensor can be prepared.

[0055] In a specific embodiment, as shown in Figure 3 , the width and spacing of the spiral line 1 are both greater than 0.08 mm, the number of layers of the printed circuit board is an even number greater than or equal to 2, and is generally 2-64 layers, for example, it can be 10 layers, 12 layers, 24 layers, 48 layers or 64 layers, etc. The optimal choice of the spacing of the spiral line is 0.1±0.05 mm. The optimal choice of the width of the spiral line is between 0.25 mm and 2.5 mm. In one specific embodiment, the spacing of the spiral line is 0.1 mm, the width of the spiral line is 1 mm, and the thickness of the spiral line is 10Z.

[0056] In a specific application, the inductance sensor prepared by fixing the spiral line on the printed circuit board can be used for inductive distance measurement alone or can be connected in multiple combinations for a magnetic field modulation environment.

[0057] In a specific use, the inductance and DC impedance of the inductance can be adjusted by adjusting the line width, spacing and number of layers of the spiral line. In the embodiment, the total inductance calculation model is constructed, and the number of spiral line layers is selected based on the target inductance value.

[0058] The total inductance calculation model is:

[0059] L 总 = nL + 2L x (K 12 + K 13 + K 14 … + K 1n + K 23 + K 24 + … + K n(n-1) )

[0060] Wherein, L is the inductance value of a single layer, K is the inductance coupling coefficient between different layers, and n is the number of printed circuit board layers.

[0061] The inductance value of a single layer is calculated as follows:

[0062]

[0063] Wherein, μ0=4π10 -7 is a coefficient, N is the number of turns of a single layer, d max is the maximum diameter of the spiral line, and d min is the minimum diameter of the spiral line.

[0064] The inductance coupling coefficient between different layers is calculated as follows:

[0065]

[0066] Wherein, N is the number of turns of the spiral line, X is the distance between the layers of the printed circuit board, and A, B, C and D are fitting coefficients.

[0067] In one embodiment, A=0.184, B=-0.525, C=1.038, and D=1.001.

[0068] Another aspect of the present application provides a preparation method of the printed circuit board spiral coil inductance sensor for strong vibration environment as described above, as shown in the following steps: Figure 4

[0069] S1, etching a spiral line on a printed circuit board, and marking the printed circuit board according to the direction of the spiral line.

[0070] ​S2, determining the number of layers of the printed circuit board according to the target inductance value, specifically:

[0071] A total inductance calculation model is constructed, and the number of layers of the printed circuit board is selected based on the target inductance value.

[0072] The total inductance calculation model is:

[0073] L 总 = nL + 2L x (K 12 + K 13 + K 14 … + K 1n + K 23 + K 24 + … + K n(n-1) )

[0074] Wherein, L is the single-layer inductance value, K is the inductance coupling coefficient between different layers, and n is the number of layers of the printed circuit board.

[0075] The single-layer inductance value calculation formula is as follows:

[0076]

[0077] Wherein, μ0=4π10 -7 is the coefficient, N is the number of turns of the single-layer spiral line, d max is the maximum spiral line diameter, d min is the minimum spiral line diameter.

[0078] The inductance coupling coefficient calculation formula between different layers is as follows:

[0079]

[0080] Wherein, N is the number of turns of the spiral line, X is the distance between the layers of the printed circuit board, and A, B, C and D are fitting coefficients.

[0081] S3, selecting two printed circuit boards with opposite spiral line directions to connect, and the spiral lines of the adjacent two layers of printed circuit boards are connected head to tail through the through holes opened on the printed circuit board.

[0082] S4, based on the number of layers of the printed circuit board determined in step S2, the multi-layer printed circuit board is sequentially connected according to the method of step S3 to obtain a multi-layer inductance coil, and a target inductance sensor is prepared. Specific embodiments

[0084] The embodiment provides a printed circuit board spiral coil inductance sensor for a strong vibration environment, in particular, a multi-layer spiral coil printed circuit board inductance sensor, the spiral coil is in a circular ring structure, and the multi-layer spiral coil circular rings are connected at the head and tail and can be used to generate a spiral tube coil. The spiral coil used for composing the inductance coil is processed on a printed circuit board through an etching process of the printed circuit board.

[0085] In the embodiment, the board material of the printed circuit board can be selected according to needs, for example, a common printed circuit board, a high-frequency board or a high-temperature-resistant board and the like. In the specific embodiment, Rogers high-frequency board material can be selected, the spiral coil is generally copper wire, and the thickness of the printed circuit board can be set as 2 mm, 2.5 mm or 3 mm and the like according to production needs.

[0086] The spiral coil has directivity, including clockwise direction and counterclockwise direction, when wiring between the multi-layer printed circuit boards, the spiral coils of adjacent layers should be opposite in direction, so as to ensure that the current directions of the spiral coils in the printed circuit boards are consistent. When connected, the spiral coils of each layer are connected at the head and tail through the through hole 4 in the printed circuit board. In the specific application, the spacing of the spiral coil can be adjusted according to needs, and is generally about 0.1 mm. The width of the spiral coil can be adjusted according to needs, and is generally between 0.25 mm and 2.5 mm. Meanwhile, the shape of the printed circuit board can be cut and marked according to the direction of the spiral coil so as to be distinguished. The printed circuit board with the spiral coil can be connected with multiple different printed circuit boards, and inductance coils for different purposes are formed.

[0087] As shown in Figure 1 and Figure 2 , the inductance coil is composed of spiral coils processed by using a printed circuit board process, the spiral coils on each printed circuit board are consistent in direction relative to the central coordinate system, the spiral coils of adjacent two printed circuit boards are opposite in direction and connected at the head and tail through the through hole of the printed circuit board. The spiral direction of the spiral coil includes clockwise direction and counterclockwise direction, the printed circuit board is cut and marked or silk-screen marked according to the spiral direction of the spiral coil, different inductance coils are formed by connecting different printed circuit boards, and the inductance sensor is prepared.

[0088] Specifically, as shown in Figure 1 and Figure 2As shown, the embodiment of the present application adopts the following technical scheme: including a circular spiral line 1, a first layer of printed circuit board 2 and adjacent layers of printed circuit board 3, and the spiral lines of the adjacent layers of printed circuit board are routed through the printed circuit board connection through hole 4. The circular spiral line 1 is printed on the single layer of printed circuit board 2 and other layers of printed circuit board through the etching process of the printed circuit board. The spiral direction of the circular spiral line 1 on the first layer of printed circuit board 2 and the adjacent layers of printed circuit board should be opposite, so as to ensure that the current direction in the spiral line of each layer of board is consistent. The circular spiral line 1 is connected between the single layer of printed circuit board 2 and the adjacent layers of printed circuit board through the printed circuit board connection through hole 4. The printed circuit board profile with chamfer 5 is used to mark the spiral line direction, which is convenient for the installation and deployment of the multi-printed circuit board coil sensor.

[0089] The single layer of printed circuit board 2 and the adjacent layers of printed circuit board 3 are part of the multi-layer printed circuit board. According to the needs, more board layers can be continued to be stacked behind the adjacent layers of printed circuit board 3 as needed, which can generally be selected from 10 layers, 12 layers, 14 layers, 16 layers or 18 layers, and generally not more than 64 layers.

[0090] In use, a total inductance calculation model is constructed, and the number of spiral lines is selected based on a target inductance value.

[0091] The total inductance calculation model is as follows:

[0092] L 总 =nL+2L×(K 12 +K 13 +K 14 …+K 1n +K 23 +K 24 +…+K n(n-1) )

[0093] Wherein, L is a single layer inductance value, K is an inductance coupling coefficient between different layers, and n is the number of printed circuit board layers.

[0094] The single layer inductance value calculation formula is as follows:

[0095]

[0096] Wherein, μ0=4π10 -7 is a coefficient, N is the number of turns of a single layer.

[0097] The inductance coupling coefficient calculation formula between different layers is as follows:

[0098]

[0099] Wherein, N is the number of spiral turns, X is the distance between the printed circuit board layers, A, B, C, D are all fitting coefficients. In an embodiment of the present application, A=0.184, B=-0.525, C=1.038, D=1.001.

[0100] In a specific embodiment, the thickness of the printed circuit board is between 2mm, 2.5mm or 3mm. The line width of the circular ring spiral line 1 is between 0.25mm-2.5mm. The line spacing of the circular ring spiral line 1 is generally around 0.1mm.

[0101] In a specific embodiment, the direction of the circular ring spiral line 1 includes clockwise direction and counterclockwise direction, which can be clockwise direction or counterclockwise direction in actual application. The shape 5 of the printed circuit board with notched corners adopts a circular ring structure design, and the notched corners are marked around the printed circuit board, which can be used to identify the current direction of the circular ring spiral line 1.

[0102] The sensor provided by the present application is suitable for the field of inductance sensors working in a strong vibration environment, such as pipes of engines and machine equipment, high-speed rotating probes, etc. In use, the inductance and direct current impedance can be adjusted by adjusting the line width, spacing and number of layers of the spiral line, and compared with the traditional process, the present application is more flexible in use. At the same time, in specific application scenarios, the inductance sensor can be used for inductive distance measurement alone or can be connected with multiple inductance sensors for magnetic field modulation environment.

[0103] The above-described embodiments are only preferred embodiments of the present application, and do not limit the scope of the present application. Without departing from the design spirit of the present application, various modifications and improvements to the technical solutions of the present application made by those skilled in the art shall fall within the protection scope of the present application as defined by the claims.

Claims

1. A printed circuit board spiral coil inductive sensor for use in environments with strong vibrations, characterized in that: The inductor coil is composed of a spiral wire fixed on a printed circuit board. The spiral wire has a circular ring structure, and the printed circuit board has an even number of layers greater than or equal to 2. The spiral direction of the spiral includes clockwise and counterclockwise directions. The spiral directions of two adjacent printed circuit boards are opposite and they are connected end to end through through holes opened on the printed circuit boards. The printed circuit boards are cut or screen-printed according to the spiral direction. Various inductor coils are formed by connecting printed circuit boards of multiple layers to obtain the target inductor sensor. The width and spacing of the spiral lines are both greater than 0.08 mm; Construct a total inductance calculation model and select the number of printed circuit board layers based on the target inductance value; The total inductance calculation model is as follows: ； Where L is the single-layer inductance value, K is the inductive coupling coefficient between different layers, and n is the number of printed circuit board layers; The formula for calculating the inductance of a single layer is as follows: ； in, It is a coefficient. , N is the number of turns in a single-layer helix. The maximum helix diameter, The minimum helix diameter; The formula for calculating the inductive coupling coefficient between different layers is as follows: ； Where N is the number of turns of the spiral, X is the interlayer distance of the printed circuit board, and A, B, C, and D are all fitting coefficients.

2. The printed circuit board spiral coil inductive sensor for strong vibration environments according to claim 1, characterized in that: A=0.184, B=-0.525, C=1.038, D=1.

001.

3. The printed circuit board spiral coil inductive sensor for strong vibration environments according to claim 1, characterized in that: The number of layers in a printed circuit board ranges from 2 to 64.

4. The printed circuit board spiral coil inductive sensor for strong vibration environments according to claim 1, characterized in that: The printed circuit board thickness is 2mm, 2.5mm or 3mm.

5. The printed circuit board spiral coil inductive sensor for strong vibration environments according to claim 1, characterized in that: The pitch of the spirals is 0.

1. 0.05mm.

6. The printed circuit board spiral coil inductive sensor for strong vibration environments according to claim 1, characterized in that: The spiral width is between 0.25mm and 2.5mm.

7. The printed circuit board spiral coil inductive sensor for strong vibration environments according to claim 1, characterized in that: The inductance and DC resistance of the inductor can be adjusted by changing the line width, spacing, and number of layers of the spiral.

8. The printed circuit board spiral coil inductive sensor for strong vibration environments according to claim 1, characterized in that: The spiral lines are etched onto the printed circuit board.

9. The printed circuit board spiral coil inductive sensor for strong vibration environments according to claim 8, characterized in that: The inductive sensor can be used alone for ranging or multiple sensors can be connected together for use in a magnetic field modulation environment.

10. A method for fabricating a printed circuit board spiral coil inductive sensor for use in strong vibration environments as described in claim 1, characterized in that: It includes the following steps: S1. Etch spiral lines on the printed circuit board and mark the printed circuit board according to the direction of the spiral lines; S2. Determine the number of layers on the printed circuit board based on the target inductance value, specifically: Construct a total inductance calculation model and select the number of printed circuit board layers based on the target inductance value; The total inductance calculation model is as follows: ； Where L is the single-layer inductance value, K is the inductive coupling coefficient between different layers, and n is the number of printed circuit board layers; The formula for calculating the inductance of a single layer is as follows: ； in, It is a coefficient. , N is the number of turns in a single-layer helix. The maximum helix diameter, The minimum helix diameter; The formula for calculating the inductive coupling coefficient between different layers is as follows: ； Where N is the number of turns of the spiral, X is the interlayer distance of the printed circuit board, and A, B, C, and D are all fitting coefficients; S3. Select two printed circuit boards with opposite spiral directions and connect them. The spirals of two adjacent printed circuit boards are connected end to end through through holes on the printed circuit boards. S4. Based on the number of printed circuit board layers determined in step S2, the multi-layer printed circuit boards are connected sequentially according to the method in step S3 to obtain multi-layer inductor coils, thereby producing the target inductor sensor.

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